[PATCH v7 0/12] media: rkisp1: Extensible parameters and companding

[PATCH v7 0/12] media: rkisp1: Extensible parameters and companding

[Jacopo Mondi]

v6->v7:
- Collect [PATCH v2 0/5] media: rkisp1: Add support for the companding block
- Fix GOC handling
- Fix newly introduced errors in checkstyle and documentation reported by
  https://gitlab.freedesktop.org/linux-media/users/jmondi/-/pipelines/1231492

v5->v6:
- Collect [v5.2 6/7] from Laurent
- Collect Paul's tags
- Add extra validation for unexpected data after the payload end as
  suggested by Sakari

v4->v5:
- Refine validation of the ext params buffer following Laurent's suggestion
- perform memcpy of the parameters buffer after sizes validation

v3->v4:
- Introduce 'union rkisp1_ext_params_config' to avoid casts in the block
  handlers

v2->v3:
- Address Laurent's comments on the uAPI:
  - rename $block_config with  just 'config'
  - reduce header size
  - rename a few fields/blocks

- Address Laurent's comment on the params node:
  - Use the plane payload for memcpy() and buffer validation
  - drop buf_out_validate() and use buf_prepare() only
  - validate the total buffer size against the buffer payload
  - use const pointers where possible

v1->v2:
- re-order patches to introduce parameters buffer caching for the existing
  "fixed" format before introducing the "extensible" format
- align all structures to 64-bit boundaries in the uAPI
- remove NO_CHANGE enablement state and cache a bitmask of enabled blocks
- address review comments in documentation

The VeriSilicon ISP8000 IP, supported through the rkisp1 driver in the Linux
kernel, is integrated in several SoCs from different vendors. Different
revisions of the IP differ in the number of supported features and in the
register space location assigned to specific ISP blocks.

The current configuration parameters format, defined in
include/uapi/linux/rkisp1-config.h is realized by a C structure (struct
rkisp1_params_cfg) which wraps other structures that allows to configure
specific ISP blocks. The layout of the parameters buffer is part of the Linux
kernel uAPI and can hardly be extended or modified to adapt it to different
revisions of the same IP.

This series proposes the introduction of a new parameters format for the RkISP1
(without dropping support for the existing one) which is designed with the goals
of being:

1) versioned: can be changed without breaking existing applications
2) extensible: new blocks and parameters can be added without breaking the uABI

To do so, a new 'struct rkisp1_ext_params_cfg' type is introduced. It wraps an
header and a data buffer, which userspace fills with configuration blocks
for each ISP block it intends to configure. The parameters buffer is thus of
different effective sizes, depending on the number of blocks userspace intends
to configure.

The kernel driver parses the data block and decides, based on the versioning
number and the platform it operates on, how to handle each block.

The parameters format is very similar to the parameters format implemented
in the in-review Mali C55 ISP driver [1]

CI pipeline [2]

[1] https://lore.kernel.org/linux-media/20240529152858.183799-15-dan.scally@ideasonboard.com/
[2] https://gitlab.freedesktop.org/linux-media/users/jmondi/-/pipelines/1231500

Jacopo Mondi (7):
  media: uapi: rkisp1-config: Add extensible params format
  media: uapi: videodev2: Add V4L2_META_FMT_RK_ISP1_EXT_PARAMS
  media: rkisp1: Add struct rkisp1_params_buffer
  media: rkisp1: Copy the parameters buffer
  media: rkisp1: Cache the currently active format
  media: rkisp1: Implement extensible params support
  media: rkisp1: Implement s_fmt/try_fmt

Laurent Pinchart (2):
  media: rkisp1: Add helper function to swap colour channels
  media: rkisp1: Add features mask to extensible block handlers

Paul Elder (3):
  media: rkisp1: Add register definitions for the companding block
  media: rkisp1: Add feature flags for BLS and compand
  media: rkisp1: Add support for the companding block

 Documentation/admin-guide/media/rkisp1.rst    |   11 +-
 .../media/v4l/metafmt-rkisp1.rst              |   57 +-
 .../platform/rockchip/rkisp1/rkisp1-common.c  |   14 +
 .../platform/rockchip/rkisp1/rkisp1-common.h  |   38 +-
 .../platform/rockchip/rkisp1/rkisp1-dev.c     |    9 +-
 .../platform/rockchip/rkisp1/rkisp1-params.c  | 1016 +++++++++++++++--
 .../platform/rockchip/rkisp1/rkisp1-regs.h    |   23 +
 .../platform/rockchip/rkisp1/rkisp1-stats.c   |   51 +-
 drivers/media/v4l2-core/v4l2-ioctl.c          |    1 +
 include/uapi/linux/rkisp1-config.h            |  576 ++++++++++
 include/uapi/linux/videodev2.h                |    1 +
 11 files changed, 1640 insertions(+), 157 deletions(-)

--
2.45.2

[PATCH v7 01/12] media: uapi: rkisp1-config: Add extensible params format

[Jacopo Mondi]

Add to the rkisp1-config.h header data types and documentation of
the extensible parameters format.

Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
---
 include/uapi/linux/rkisp1-config.h | 489 +++++++++++++++++++++++++++++
 1 file changed, 489 insertions(+)

diff --git a/include/uapi/linux/rkisp1-config.h b/include/uapi/linux/rkisp1-config.h
index 6eeaf8bf2362..00b09c92cca7 100644
--- a/include/uapi/linux/rkisp1-config.h
+++ b/include/uapi/linux/rkisp1-config.h
@@ -996,4 +996,493 @@ struct rkisp1_stat_buffer {
 	struct rkisp1_cif_isp_stat params;
 };
 
+/*---------- PART3: Extensible Configuration Parameters  ------------*/
+
+/**
+ * enum rkisp1_ext_params_block_type - RkISP1 extensible params block type
+ *
+ * @RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS: Black level subtraction
+ * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC: Defect pixel cluster correction
+ * @RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG: Sensor de-gamma
+ * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN: Auto white balance gains
+ * @RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT: ISP filtering
+ * @RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM: Bayer de-mosaic
+ * @RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK: Cross-talk correction
+ * @RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC: Gamma out correction
+ * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF: De-noise pre-filter
+ * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH: De-noise pre-filter strength
+ * @RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC: Color processing
+ * @RKISP1_EXT_PARAMS_BLOCK_TYPE_IE: Image effects
+ * @RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC: Lens shading correction
+ * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS: Auto white balance statistics
+ * @RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS: Histogram statistics
+ * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS: Auto exposure statistics
+ * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS: Auto-focus statistics
+ */
+enum rkisp1_ext_params_block_type {
+	RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS,
+	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC,
+	RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG,
+	RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN,
+	RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT,
+	RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM,
+	RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK,
+	RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC,
+	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF,
+	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH,
+	RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC,
+	RKISP1_EXT_PARAMS_BLOCK_TYPE_IE,
+	RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC,
+	RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS,
+	RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS,
+	RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS,
+	RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS,
+};
+
+/**
+ * enum rkisp1_ext_params_block_enable - RkISP1 extensible parameter block
+ *					 enable flags
+ *
+ * @RKISP1_EXT_PARAMS_BLOCK_DISABLE: Disable the HW block
+ * @RKISP1_EXT_PARAMS_BLOCK_ENABLE: Enable the HW block
+ */
+enum rkisp1_ext_params_block_enable {
+	RKISP1_EXT_PARAMS_BLOCK_DISABLE,
+	RKISP1_EXT_PARAMS_BLOCK_ENABLE,
+};
+
+/**
+ * struct rkisp1_ext_params_block_header - RkISP1 extensible parameter block
+ *					   header
+ *
+ * This structure represents the common part of all the ISP configuration
+ * blocks. Each parameters block shall embed an instance of this structure type
+ * as its first member, followed by the block-specific configuration data. The
+ * driver inspects this common header to discern the block type and its size and
+ * properly handle the block content by casting it to the correct block-specific
+ * type.
+ *
+ * The @type field is one of the values enumerated by
+ * :c:type:`rkisp1_ext_params_block_type` and specifies how the data should be
+ * interpreted by the driver. The @size field specifies the size of the
+ * parameters block and is used by the driver for validation purposes.
+ *
+ * The @enable field specifies the ISP block enablement state. The possible
+ * enablement states are enumerated by :c:type:`rkisp1_ext_params_block_enable`.
+ * When userspace needs to configure and enable an ISP block it shall fully
+ * populate the block configuration and the @enable flag shall be set to
+ * RKISP1_EXT_PARAMS_BLOCK_ENABLE. When userspace simply wants to disable the
+ * ISP block the @enable flag shall be set to RKISP1_EXT_PARAMS_BLOCK_DISABLE.
+ * The driver ignores the rest of the block configuration structure in this
+ * case.
+ *
+ * If a new configuration of an ISP block has to be applied userspace shall
+ * fully populate the ISP block configuration and set the @enable flag to
+ * RKISP1_EXT_PARAMS_BLOCK_ENABLE.
+ *
+ * Userspace is responsible for correctly populating the parameters block header
+ * fields (@type, @enable and @size) and the block-specific parameters.
+ *
+ * For example:
+ *
+ * .. code-block:: c
+ *
+ *	void populate_bls(struct rkisp1_ext_params_block_header *block) {
+ *		struct rkisp1_ext_params_bls_config *bls =
+ *			(struct rkisp1_ext_params_bls_config *)block;
+ *
+ *		bls->header.type = RKISP1_EXT_PARAMS_BLOCK_ID_BLS;
+ *		bls->header.enable = RKISP1_EXT_PARAMS_BLOCK_ENABLE;
+ *		bls->header.size = sizeof(*bls);
+ *
+ *		bls->config.enable_auto = 0;
+ *		bls->config.fixed_val.r = blackLevelRed_;
+ *		bls->config.fixed_val.gr = blackLevelGreenR_;
+ *		bls->config.fixed_val.gb = blackLevelGreenB_;
+ *		bls->config.fixed_val.b = blackLevelBlue_;
+ *	}
+ *
+ * @type: The parameters block type, see
+ *	  :c:type:`rkisp1_ext_params_block_type`
+ * @enable: The block enable flag, see
+ *	   :c:type:`rkisp1_ext_params_block_enable`
+ * @size: Size (in bytes) of the parameters block, including this header
+ */
+struct rkisp1_ext_params_block_header {
+	__u16 type;
+	__u16 enable;
+	__u16 size;
+} __attribute__((aligned(8)));
+
+/**
+ * struct rkisp1_ext_params_bls_config - RkISP1 extensible params BLS config
+ *
+ * RkISP1 extensible parameters Black Level Subtraction configuration block.
+ * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS`.
+ *
+ * @header: The RkISP1 extensible parameters header, see
+ *	    :c:type:`rkisp1_ext_params_block_header`
+ * @config: Black Level Subtraction configuration, see
+ *	    :c:type:`rkisp1_cif_isp_bls_config`
+ */
+struct rkisp1_ext_params_bls_config {
+	struct rkisp1_ext_params_block_header header;
+	struct rkisp1_cif_isp_bls_config config;
+} __attribute__((aligned(8)));
+
+/**
+ * struct rkisp1_ext_params_dpcc_config - RkISP1 extensible params DPCC config
+ *
+ * RkISP1 extensible parameters Defective Pixel Cluster Correction configuration
+ * block. Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC`.
+ *
+ * @header: The RkISP1 extensible parameters header, see
+ *	    :c:type:`rkisp1_ext_params_block_header`
+ * @config: Defective Pixel Cluster Correction configuration, see
+ *	    :c:type:`rkisp1_cif_isp_dpcc_config`
+ */
+struct rkisp1_ext_params_dpcc_config {
+	struct rkisp1_ext_params_block_header header;
+	struct rkisp1_cif_isp_dpcc_config config;
+} __attribute__((aligned(8)));
+
+/**
+ * struct rkisp1_ext_params_sdg_config - RkISP1 extensible params SDG config
+ *
+ * RkISP1 extensible parameters Sensor Degamma configuration block. Identified
+ * by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG`.
+ *
+ * @header: The RkISP1 extensible parameters header, see
+ *	    :c:type:`rkisp1_ext_params_block_header`
+ * @config: Sensor Degamma configuration, see
+ *	    :c:type:`rkisp1_cif_isp_sdg_config`
+ */
+struct rkisp1_ext_params_sdg_config {
+	struct rkisp1_ext_params_block_header header;
+	struct rkisp1_cif_isp_sdg_config config;
+} __attribute__((aligned(8)));
+
+/**
+ * struct rkisp1_ext_params_lsc_config - RkISP1 extensible params LSC config
+ *
+ * RkISP1 extensible parameters Lens Shading Correction configuration block.
+ * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC`.
+ *
+ * @header: The RkISP1 extensible parameters header, see
+ *	    :c:type:`rkisp1_ext_params_block_header`
+ * @config: Lens Shading Correction configuration, see
+ *	    :c:type:`rkisp1_cif_isp_lsc_config`
+ */
+struct rkisp1_ext_params_lsc_config {
+	struct rkisp1_ext_params_block_header header;
+	struct rkisp1_cif_isp_lsc_config config;
+} __attribute__((aligned(8)));
+
+/**
+ * struct rkisp1_ext_params_awb_gain_config - RkISP1 extensible params AWB
+ *					      gain config
+ *
+ * RkISP1 extensible parameters Auto-White Balance Gains configuration block.
+ * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN`.
+ *
+ * @header: The RkISP1 extensible parameters header, see
+ *	    :c:type:`rkisp1_ext_params_block_header`
+ * @config: Auto-White Balance Gains configuration, see
+ *	    :c:type:`rkisp1_cif_isp_awb_gain_config`
+ */
+struct rkisp1_ext_params_awb_gain_config {
+	struct rkisp1_ext_params_block_header header;
+	struct rkisp1_cif_isp_awb_gain_config config;
+} __attribute__((aligned(8)));
+
+/**
+ * struct rkisp1_ext_params_flt_config - RkISP1 extensible params FLT config
+ *
+ * RkISP1 extensible parameters Filter configuration block. Identified by
+ * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT`.
+ *
+ * @header: The RkISP1 extensible parameters header, see
+ *	    :c:type:`rkisp1_ext_params_block_header`
+ * @config: Filter configuration, see :c:type:`rkisp1_cif_isp_flt_config`
+ */
+struct rkisp1_ext_params_flt_config {
+	struct rkisp1_ext_params_block_header header;
+	struct rkisp1_cif_isp_flt_config config;
+} __attribute__((aligned(8)));
+
+/**
+ * struct rkisp1_ext_params_bdm_config - RkISP1 extensible params BDM config
+ *
+ * RkISP1 extensible parameters Demosaicing configuration block. Identified by
+ * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM`.
+ *
+ * @header: The RkISP1 extensible parameters header, see
+ *	    :c:type:`rkisp1_ext_params_block_header`
+ * @config: Demosaicing configuration, see :c:type:`rkisp1_cif_isp_bdm_config`
+ */
+struct rkisp1_ext_params_bdm_config {
+	struct rkisp1_ext_params_block_header header;
+	struct rkisp1_cif_isp_bdm_config config;
+} __attribute__((aligned(8)));
+
+/**
+ * struct rkisp1_ext_params_ctk_config - RkISP1 extensible params CTK config
+ *
+ * RkISP1 extensible parameters Cross-Talk configuration block. Identified by
+ * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK`.
+ *
+ * @header: The RkISP1 extensible parameters header, see
+ *	    :c:type:`rkisp1_ext_params_block_header`
+ * @config: Cross-Talk configuration, see :c:type:`rkisp1_cif_isp_ctk_config`
+ */
+struct rkisp1_ext_params_ctk_config {
+	struct rkisp1_ext_params_block_header header;
+	struct rkisp1_cif_isp_ctk_config config;
+} __attribute__((aligned(8)));
+
+/**
+ * struct rkisp1_ext_params_goc_config - RkISP1 extensible params GOC config
+ *
+ * RkISP1 extensible parameters Gamma-Out configuration block. Identified by
+ * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC`.
+ *
+ * @header: The RkISP1 extensible parameters header, see
+ *	    :c:type:`rkisp1_ext_params_block_header`
+ * @config: Gamma-Out configuration, see :c:type:`rkisp1_cif_isp_goc_config`
+ */
+struct rkisp1_ext_params_goc_config {
+	struct rkisp1_ext_params_block_header header;
+	struct rkisp1_cif_isp_goc_config config;
+} __attribute__((aligned(8)));
+
+/**
+ * struct rkisp1_ext_params_dpf_config - RkISP1 extensible params DPF config
+ *
+ * RkISP1 extensible parameters De-noise Pre-Filter configuration block.
+ * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF`.
+ *
+ * @header: The RkISP1 extensible parameters header, see
+ *	    :c:type:`rkisp1_ext_params_block_header`
+ * @config: De-noise Pre-Filter configuration, see
+ *	    :c:type:`rkisp1_cif_isp_dpf_config`
+ */
+struct rkisp1_ext_params_dpf_config {
+	struct rkisp1_ext_params_block_header header;
+	struct rkisp1_cif_isp_dpf_config config;
+} __attribute__((aligned(8)));
+
+/**
+ * struct rkisp1_ext_params_dpf_strength_config - RkISP1 extensible params DPF
+ *						  strength config
+ *
+ * RkISP1 extensible parameters De-noise Pre-Filter strength configuration
+ * block. Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH`.
+ *
+ * @header: The RkISP1 extensible parameters header, see
+ *	    :c:type:`rkisp1_ext_params_block_header`
+ * @config: De-noise Pre-Filter strength configuration, see
+ *	    :c:type:`rkisp1_cif_isp_dpf_strength_config`
+ */
+struct rkisp1_ext_params_dpf_strength_config {
+	struct rkisp1_ext_params_block_header header;
+	struct rkisp1_cif_isp_dpf_strength_config config;
+} __attribute__((aligned(8)));
+
+/**
+ * struct rkisp1_ext_params_cproc_config - RkISP1 extensible params CPROC config
+ *
+ * RkISP1 extensible parameters Color Processing configuration block.
+ * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC`.
+ *
+ * @header: The RkISP1 extensible parameters header, see
+ *	    :c:type:`rkisp1_ext_params_block_header`
+ * @config: Color processing configuration, see
+ *	    :c:type:`rkisp1_cif_isp_cproc_config`
+ */
+struct rkisp1_ext_params_cproc_config {
+	struct rkisp1_ext_params_block_header header;
+	struct rkisp1_cif_isp_cproc_config config;
+} __attribute__((aligned(8)));
+
+/**
+ * struct rkisp1_ext_params_ie_config - RkISP1 extensible params IE config
+ *
+ * RkISP1 extensible parameters Image Effect configuration block. Identified by
+ * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_IE`.
+ *
+ * @header: The RkISP1 extensible parameters header, see
+ *	    :c:type:`rkisp1_ext_params_block_header`
+ * @config: Image Effect configuration, see :c:type:`rkisp1_cif_isp_ie_config`
+ */
+struct rkisp1_ext_params_ie_config {
+	struct rkisp1_ext_params_block_header header;
+	struct rkisp1_cif_isp_ie_config config;
+} __attribute__((aligned(8)));
+
+/**
+ * struct rkisp1_ext_params_awb_meas_config - RkISP1 extensible params AWB
+ *					      Meas config
+ *
+ * RkISP1 extensible parameters Auto-White Balance Measurement configuration
+ * block. Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS`.
+ *
+ * @header: The RkISP1 extensible parameters header, see
+ *	    :c:type:`rkisp1_ext_params_block_header`
+ * @config: Auto-White Balance measure configuration, see
+ *	    :c:type:`rkisp1_cif_isp_awb_meas_config`
+ */
+struct rkisp1_ext_params_awb_meas_config {
+	struct rkisp1_ext_params_block_header header;
+	struct rkisp1_cif_isp_awb_meas_config config;
+} __attribute__((aligned(8)));
+
+/**
+ * struct rkisp1_ext_params_hst_config - RkISP1 extensible params Histogram config
+ *
+ * RkISP1 extensible parameters Histogram statistics configuration block.
+ * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS`.
+ *
+ * @header: The RkISP1 extensible parameters header, see
+ *	    :c:type:`rkisp1_ext_params_block_header`
+ * @config: Histogram statistics configuration, see
+ *	    :c:type:`rkisp1_cif_isp_hst_config`
+ */
+struct rkisp1_ext_params_hst_config {
+	struct rkisp1_ext_params_block_header header;
+	struct rkisp1_cif_isp_hst_config config;
+} __attribute__((aligned(8)));
+
+/**
+ * struct rkisp1_ext_params_aec_config - RkISP1 extensible params AEC config
+ *
+ * RkISP1 extensible parameters Auto-Exposure statistics configuration block.
+ * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS`.
+ *
+ * @header: The RkISP1 extensible parameters header, see
+ *	    :c:type:`rkisp1_ext_params_block_header`
+ * @config: Auto-Exposure statistics configuration, see
+ *	    :c:type:`rkisp1_cif_isp_aec_config`
+ */
+struct rkisp1_ext_params_aec_config {
+	struct rkisp1_ext_params_block_header header;
+	struct rkisp1_cif_isp_aec_config config;
+} __attribute__((aligned(8)));
+
+/**
+ * struct rkisp1_ext_params_afc_config - RkISP1 extensible params AFC config
+ *
+ * RkISP1 extensible parameters Auto-Focus statistics configuration block.
+ * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS`.
+ *
+ * @header: The RkISP1 extensible parameters header, see
+ *	    :c:type:`rkisp1_ext_params_block_header`
+ * @config: Auto-Focus statistics configuration, see
+ *	    :c:type:`rkisp1_cif_isp_afc_config`
+ */
+struct rkisp1_ext_params_afc_config {
+	struct rkisp1_ext_params_block_header header;
+	struct rkisp1_cif_isp_afc_config config;
+} __attribute__((aligned(8)));
+
+#define RKISP1_EXT_PARAMS_MAX_SIZE					\
+	(sizeof(struct rkisp1_ext_params_bls_config)			+\
+	sizeof(struct rkisp1_ext_params_dpcc_config)			+\
+	sizeof(struct rkisp1_ext_params_sdg_config)			+\
+	sizeof(struct rkisp1_ext_params_lsc_config)			+\
+	sizeof(struct rkisp1_ext_params_awb_gain_config)		+\
+	sizeof(struct rkisp1_ext_params_flt_config)			+\
+	sizeof(struct rkisp1_ext_params_bdm_config)			+\
+	sizeof(struct rkisp1_ext_params_ctk_config)			+\
+	sizeof(struct rkisp1_ext_params_goc_config)			+\
+	sizeof(struct rkisp1_ext_params_dpf_config)			+\
+	sizeof(struct rkisp1_ext_params_dpf_strength_config)		+\
+	sizeof(struct rkisp1_ext_params_cproc_config)			+\
+	sizeof(struct rkisp1_ext_params_ie_config)			+\
+	sizeof(struct rkisp1_ext_params_awb_meas_config)		+\
+	sizeof(struct rkisp1_ext_params_hst_config)			+\
+	sizeof(struct rkisp1_ext_params_aec_config)			+\
+	sizeof(struct rkisp1_ext_params_afc_config))
+
+/**
+ * enum rksip1_ext_param_buffer_version - RkISP1 extensible parameters version
+ *
+ * @RKISP1_EXT_PARAM_BUFFER_V1: First version of RkISP1 extensible parameters
+ */
+enum rksip1_ext_param_buffer_version {
+	RKISP1_EXT_PARAM_BUFFER_V1 = 1,
+};
+
+/**
+ * struct rkisp1_ext_params_cfg - RkISP1 extensible parameters configuration
+ *
+ * This struct contains the configuration parameters of the RkISP1 ISP
+ * algorithms, serialized by userspace into a data buffer. Each configuration
+ * parameter block is represented by a block-specific structure which contains a
+ * :c:type:`rkisp1_ext_params_block_header` entry as first member. Userspace
+ * populates the @data buffer with configuration parameters for the blocks that
+ * it intends to configure. As a consequence, the data buffer effective size
+ * changes according to the number of ISP blocks that userspace intends to
+ * configure and is set by userspace in the @data_size field.
+ *
+ * The parameters buffer is versioned by the @version field to allow modifying
+ * and extending its definition. Userspace shall populate the @version field to
+ * inform the driver about the version it intends to use. The driver will parse
+ * and handle the @data buffer according to the data layout specific to the
+ * indicated version and return an error if the desired version is not
+ * supported.
+ *
+ * For each ISP block that userspace wants to configure, a block-specific
+ * structure is appended to the @data buffer, one after the other without gaps
+ * in between nor overlaps. Userspace shall populate the @data_size field with
+ * the effective size, in bytes, of the @data buffer.
+ *
+ * The expected memory layout of the parameters buffer is::
+ *
+ *	+-------------------- struct rkisp1_ext_params_cfg -------------------+
+ *	| version = RKISP_EXT_PARAMS_BUFFER_V1;                               |
+ *	| data_size = sizeof(struct rkisp1_ext_params_bls_config)             |
+ *	|           + sizeof(struct rkisp1_ext_params_dpcc_config);           |
+ *	| +------------------------- data  ---------------------------------+ |
+ *	| | +------------- struct rkisp1_ext_params_bls_config -----------+ | |
+ *	| | | +-------- struct rkisp1_ext_params_block_header  ---------+ | | |
+ *	| | | | type = RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS;                | | | |
+ *	| | | | enable = RKISP1_EXT_PARAMS_BLOCK_ENABLE;                | | | |
+ *	| | | | size = sizeof(struct rkisp1_ext_params_bls_config);     | | | |
+ *	| | | +---------------------------------------------------------+ | | |
+ *	| | | +---------- struct rkisp1_cif_isp_bls_config -------------+ | | |
+ *	| | | | enable_auto = 0;                                        | | | |
+ *	| | | | fixed_val.r = 256;                                      | | | |
+ *	| | | | fixed_val.gr = 256;                                     | | | |
+ *	| | | | fixed_val.gb = 256;                                     | | | |
+ *	| | | | fixed_val.b = 256;                                      | | | |
+ *	| | | +---------------------------------------------------------+ | | |
+ *	| | +------------ struct rkisp1_ext_params_dpcc_config -----------+ | |
+ *	| | | +-------- struct rkisp1_ext_params_block_header  ---------+ | | |
+ *	| | | | type = RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC;               | | | |
+ *	| | | | enable = RKISP1_EXT_PARAMS_BLOCK_ENABLE;                | | | |
+ *	| | | | size = sizeof(struct rkisp1_ext_params_dpcc_config);    | | | |
+ *	| | | +---------------------------------------------------------+ | | |
+ *	| | | +---------- struct rkisp1_cif_isp_dpcc_config ------------+ | | |
+ *	| | | | mode = RKISP1_CIF_ISP_DPCC_MODE_STAGE1_ENABLE;          | | | |
+ *	| | | | output_mode =                                           | | | |
+ *	| | | |   RKISP1_CIF_ISP_DPCC_OUTPUT_MODE_STAGE1_INCL_G_CENTER; | | | |
+ *	| | | | set_use = ... ;                                         | | | |
+ *	| | | | ...  = ... ;                                            | | | |
+ *	| | | +---------------------------------------------------------+ | | |
+ *	| | +-------------------------------------------------------------+ | |
+ *	| +-----------------------------------------------------------------+ |
+ *	+---------------------------------------------------------------------+
+ *
+ * @version: The RkISP1 extensible parameters buffer version, see
+ *	     :c:type:`rksip1_ext_param_buffer_version`
+ * @data_size: The RkISP1 configuration data effective size, excluding this
+ *	       header
+ * @data: The RkISP1 extensible configuration data blocks
+ */
+struct rkisp1_ext_params_cfg {
+	__u32 version;
+	__u32 data_size;
+	__u8 data[RKISP1_EXT_PARAMS_MAX_SIZE];
+};
+
 #endif /* _UAPI_RKISP1_CONFIG_H */
-- 
2.45.2

[PATCH v7 02/12] media: uapi: videodev2: Add V4L2_META_FMT_RK_ISP1_EXT_PARAMS

[Jacopo Mondi]

The rkisp1 driver stores ISP configuration parameters in the fixed
rkisp1_params_cfg structure. As the members of the structure are part of
the userspace API, the structure layout is immutable and cannot be
extended further. Introducing new parameters or modifying the existing
ones would change the buffer layout and cause breakages in existing
applications.

The allow for future extensions to the ISP parameters, introduce a new
extensible parameters format, with a new format 4CC. Document usage of
the new format in the rkisp1 admin guide.

Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Reviewed-by: Daniel Scally <dan.scally@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 Documentation/admin-guide/media/rkisp1.rst    | 11 +++-
 .../media/v4l/metafmt-rkisp1.rst              | 57 ++++++++++++++++---
 drivers/media/v4l2-core/v4l2-ioctl.c          |  1 +
 include/uapi/linux/videodev2.h                |  1 +
 4 files changed, 59 insertions(+), 11 deletions(-)

diff --git a/Documentation/admin-guide/media/rkisp1.rst b/Documentation/admin-guide/media/rkisp1.rst
index 6f14d9561fa5..6c878c71442f 100644
--- a/Documentation/admin-guide/media/rkisp1.rst
+++ b/Documentation/admin-guide/media/rkisp1.rst
@@ -114,11 +114,18 @@ to be applied to the hardware during a video stream, allowing userspace
 to dynamically modify values such as black level, cross talk corrections
 and others.
 
-The buffer format is defined by struct :c:type:`rkisp1_params_cfg`, and
-userspace should set
+The ISP driver supports two different parameters configuration methods, the
+`fixed parameters format` or the `extensible parameters format`.
+
+When using the `fixed parameters` method the buffer format is defined by struct
+:c:type:`rkisp1_params_cfg`, and userspace should set
 :ref:`V4L2_META_FMT_RK_ISP1_PARAMS <v4l2-meta-fmt-rk-isp1-params>` as the
 dataformat.
 
+When using the `extensible parameters` method the buffer format is defined by
+struct :c:type:`rkisp1_ext_params_cfg`, and userspace should set
+:ref:`V4L2_META_FMT_RK_ISP1_EXT_PARAMS <v4l2-meta-fmt-rk-isp1-ext-params>` as
+the dataformat.
 
 Capturing Video Frames Example
 ==============================
diff --git a/Documentation/userspace-api/media/v4l/metafmt-rkisp1.rst b/Documentation/userspace-api/media/v4l/metafmt-rkisp1.rst
index fa04f00bcd2e..4e3f4ea9e1c8 100644
--- a/Documentation/userspace-api/media/v4l/metafmt-rkisp1.rst
+++ b/Documentation/userspace-api/media/v4l/metafmt-rkisp1.rst
@@ -1,28 +1,67 @@
 .. SPDX-License-Identifier: GPL-2.0
 
-.. _v4l2-meta-fmt-rk-isp1-params:
-
 .. _v4l2-meta-fmt-rk-isp1-stat-3a:
 
-*****************************************************************************
-V4L2_META_FMT_RK_ISP1_PARAMS ('rk1p'), V4L2_META_FMT_RK_ISP1_STAT_3A ('rk1s')
-*****************************************************************************
+************************************************************************************************************************
+V4L2_META_FMT_RK_ISP1_PARAMS ('rk1p'), V4L2_META_FMT_RK_ISP1_STAT_3A ('rk1s'), V4L2_META_FMT_RK_ISP1_EXT_PARAMS ('rk1e')
+************************************************************************************************************************
 
+========================
 Configuration parameters
 ========================
 
-The configuration parameters are passed to the
+The configuration of the RkISP1 ISP is performed by userspace by providing
+parameters for the ISP to the driver using the :c:type:`v4l2_meta_format`
+interface.
+
+There are two methods that allow to configure the ISP, the `fixed parameters`
+configuration format and the `extensible parameters` configuration
+format.
+
+.. _v4l2-meta-fmt-rk-isp1-params:
+
+Fixed parameters configuration format
+=====================================
+
+When using the fixed configuration format, parameters are passed to the
 :ref:`rkisp1_params <rkisp1_params>` metadata output video node, using
-the :c:type:`v4l2_meta_format` interface. The buffer contains
-a single instance of the C structure :c:type:`rkisp1_params_cfg` defined in
-``rkisp1-config.h``. So the structure can be obtained from the buffer by:
+the `V4L2_META_FMT_RK_ISP1_PARAMS` meta format.
+
+The buffer contains a single instance of the C structure
+:c:type:`rkisp1_params_cfg` defined in ``rkisp1-config.h``. So the structure can
+be obtained from the buffer by:
 
 .. code-block:: c
 
 	struct rkisp1_params_cfg *params = (struct rkisp1_params_cfg*) buffer;
 
+This method supports a subset of the ISP features only, new applications should
+use the extensible parameters method.
+
+.. _v4l2-meta-fmt-rk-isp1-ext-params:
+
+Extensible parameters configuration format
+==========================================
+
+When using the extensible configuration format, parameters are passed to the
+:ref:`rkisp1_params <rkisp1_params>` metadata output video node, using
+the `V4L2_META_FMT_RK_ISP1_EXT_PARAMS` meta format.
+
+The buffer contains a single instance of the C structure
+:c:type:`rkisp1_ext_params_cfg` defined in ``rkisp1-config.h``. The
+:c:type:`rkisp1_ext_params_cfg` structure is designed to allow userspace to
+populate the data buffer with only the configuration data for the ISP blocks it
+intends to configure. The extensible parameters format design allows developers
+to define new block types to support new configuration parameters, and defines a
+versioning scheme so that it can be extended and versioned without breaking
+compatibility with existing applications.
+
+For these reasons, this configuration method if preferred over the `fixed
+parameters` format alternative.
+
 .. rkisp1_stat_buffer
 
+===========================
 3A and histogram statistics
 ===========================
 
diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
index 5eb4d797d259..257d69341953 100644
--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c
@@ -1458,6 +1458,7 @@ static void v4l_fill_fmtdesc(struct v4l2_fmtdesc *fmt)
 	case V4L2_META_FMT_VIVID:       descr = "Vivid Metadata"; break;
 	case V4L2_META_FMT_RK_ISP1_PARAMS:	descr = "Rockchip ISP1 3A Parameters"; break;
 	case V4L2_META_FMT_RK_ISP1_STAT_3A:	descr = "Rockchip ISP1 3A Statistics"; break;
+	case V4L2_META_FMT_RK_ISP1_EXT_PARAMS:	descr = "Rockchip ISP1 Ext 3A Params"; break;
 	case V4L2_PIX_FMT_NV12_8L128:	descr = "NV12 (8x128 Linear)"; break;
 	case V4L2_PIX_FMT_NV12M_8L128:	descr = "NV12M (8x128 Linear)"; break;
 	case V4L2_PIX_FMT_NV12_10BE_8L128:	descr = "10-bit NV12 (8x128 Linear, BE)"; break;
diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index 4e91362da6da..725e86c4bbbd 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -854,6 +854,7 @@ struct v4l2_pix_format {
 /* Vendor specific - used for RK_ISP1 camera sub-system */
 #define V4L2_META_FMT_RK_ISP1_PARAMS	v4l2_fourcc('R', 'K', '1', 'P') /* Rockchip ISP1 3A Parameters */
 #define V4L2_META_FMT_RK_ISP1_STAT_3A	v4l2_fourcc('R', 'K', '1', 'S') /* Rockchip ISP1 3A Statistics */
+#define V4L2_META_FMT_RK_ISP1_EXT_PARAMS	v4l2_fourcc('R', 'K', '1', 'E') /* Rockchip ISP1 3a Extensible Parameters */
 
 /* Vendor specific - used for RaspberryPi PiSP */
 #define V4L2_META_FMT_RPI_BE_CFG	v4l2_fourcc('R', 'P', 'B', 'C') /* PiSP BE configuration */
-- 
2.45.2

[PATCH v7 03/12] media: rkisp1: Add struct rkisp1_params_buffer

[Jacopo Mondi]

Create the 'struct rkisp1_params_buffer' type that wraps a
vb2_v4l2_buffer to prepare to hold a copy of the parameters buffer that
will be used to cache the user-provided configuration buffer in the
following patches.

Replace usage of 'struct rkisp1_buffer' with 'struct
rkisp1_params_buffer' in rkisp1-params.c to prepare for that.

Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Reviewed-by: Daniel Scally <dan.scally@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
---
 .../platform/rockchip/rkisp1/rkisp1-common.h  | 14 ++++++++++++-
 .../platform/rockchip/rkisp1/rkisp1-params.c  | 21 ++++++++++---------
 2 files changed, 24 insertions(+), 11 deletions(-)

diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h b/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h
index 26573f6ae575..a615bbb0255e 100644
--- a/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h
+++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h
@@ -232,7 +232,7 @@ struct rkisp1_vdev_node {
 
 /*
  * struct rkisp1_buffer - A container for the vb2 buffers used by the video devices:
- *			  params, stats, mainpath, selfpath
+ *			  stats, mainpath, selfpath
  *
  * @vb:		vb2 buffer
  * @queue:	entry of the buffer in the queue
@@ -244,6 +244,18 @@ struct rkisp1_buffer {
 	dma_addr_t buff_addr[VIDEO_MAX_PLANES];
 };
 
+/*
+ * struct rkisp1_params_buffer - A container for the vb2 buffers used by the
+ *				 params video device
+ *
+ * @vb:		vb2 buffer
+ * @queue:	entry of the buffer in the queue
+ */
+struct rkisp1_params_buffer {
+	struct vb2_v4l2_buffer vb;
+	struct list_head queue;
+};
+
 /*
  * struct rkisp1_dummy_buffer - A buffer to write the next frame to in case
  *				there are no vb2 buffers available.
diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c b/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c
index 173d1ea41874..2844e55bc4f2 100644
--- a/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c
+++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c
@@ -1502,20 +1502,21 @@ static void rkisp1_isp_isr_meas_config(struct rkisp1_params *params,
 }
 
 static bool rkisp1_params_get_buffer(struct rkisp1_params *params,
-				     struct rkisp1_buffer **buf,
+				     struct rkisp1_params_buffer **buf,
 				     struct rkisp1_params_cfg **cfg)
 {
 	if (list_empty(&params->params))
 		return false;
 
-	*buf = list_first_entry(&params->params, struct rkisp1_buffer, queue);
+	*buf = list_first_entry(&params->params, struct rkisp1_params_buffer,
+				queue);
 	*cfg = vb2_plane_vaddr(&(*buf)->vb.vb2_buf, 0);
 
 	return true;
 }
 
 static void rkisp1_params_complete_buffer(struct rkisp1_params *params,
-					  struct rkisp1_buffer *buf,
+					  struct rkisp1_params_buffer *buf,
 					  unsigned int frame_sequence)
 {
 	list_del(&buf->queue);
@@ -1528,7 +1529,7 @@ void rkisp1_params_isr(struct rkisp1_device *rkisp1)
 {
 	struct rkisp1_params *params = &rkisp1->params;
 	struct rkisp1_params_cfg *new_params;
-	struct rkisp1_buffer *cur_buf;
+	struct rkisp1_params_buffer *cur_buf;
 
 	spin_lock(&params->config_lock);
 
@@ -1604,7 +1605,7 @@ void rkisp1_params_pre_configure(struct rkisp1_params *params,
 {
 	struct rkisp1_cif_isp_hst_config hst = rkisp1_hst_params_default_config;
 	struct rkisp1_params_cfg *new_params;
-	struct rkisp1_buffer *cur_buf;
+	struct rkisp1_params_buffer *cur_buf;
 
 	params->quantization = quantization;
 	params->ycbcr_encoding = ycbcr_encoding;
@@ -1650,7 +1651,7 @@ void rkisp1_params_pre_configure(struct rkisp1_params *params,
 void rkisp1_params_post_configure(struct rkisp1_params *params)
 {
 	struct rkisp1_params_cfg *new_params;
-	struct rkisp1_buffer *cur_buf;
+	struct rkisp1_params_buffer *cur_buf;
 
 	spin_lock_irq(&params->config_lock);
 
@@ -1821,8 +1822,8 @@ static int rkisp1_params_vb2_queue_setup(struct vb2_queue *vq,
 static void rkisp1_params_vb2_buf_queue(struct vb2_buffer *vb)
 {
 	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
-	struct rkisp1_buffer *params_buf =
-		container_of(vbuf, struct rkisp1_buffer, vb);
+	struct rkisp1_params_buffer *params_buf =
+		container_of(vbuf, struct rkisp1_params_buffer, vb);
 	struct vb2_queue *vq = vb->vb2_queue;
 	struct rkisp1_params *params = vq->drv_priv;
 
@@ -1844,7 +1845,7 @@ static int rkisp1_params_vb2_buf_prepare(struct vb2_buffer *vb)
 static void rkisp1_params_vb2_stop_streaming(struct vb2_queue *vq)
 {
 	struct rkisp1_params *params = vq->drv_priv;
-	struct rkisp1_buffer *buf;
+	struct rkisp1_params_buffer *buf;
 	LIST_HEAD(tmp_list);
 
 	/*
@@ -1890,7 +1891,7 @@ static int rkisp1_params_init_vb2_queue(struct vb2_queue *q,
 	q->drv_priv = params;
 	q->ops = &rkisp1_params_vb2_ops;
 	q->mem_ops = &vb2_vmalloc_memops;
-	q->buf_struct_size = sizeof(struct rkisp1_buffer);
+	q->buf_struct_size = sizeof(struct rkisp1_params_buffer);
 	q->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
 	q->lock = &node->vlock;
 
-- 
2.45.2

[PATCH v7 04/12] media: rkisp1: Copy the parameters buffer

[Jacopo Mondi]

The ISP parameters buffers are queued by userspace to the params video
device and appended by the driver to the list of available buffers for
later consumption.

As the parameters buffer is mapped in the userspace process memory,
applications have access to the buffer content after the buffer has
been queued.

To prevent userspace from modifying the contents of the parameters buffer
after it has been queued to the video device, add to 'struct
rkisp1_params_buffer' a scratch buffer where to copy the parameters.

Allocate the scratch buffer in the vb2 buf_init() operation and copy the
buffer content in the buf_prepare() operation. Free the scratch
buffer in the newly introduced buf_cleanup() operation handler.

Modify the ISP configuration function to access the ISP configuration
from the cached copy of the parameters buffer instead of using the
userspace-mapped one.

Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
---
 .../platform/rockchip/rkisp1/rkisp1-common.h  |  8 ++
 .../platform/rockchip/rkisp1/rkisp1-params.c  | 83 ++++++++++++-------
 2 files changed, 60 insertions(+), 31 deletions(-)

diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h b/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h
index a615bbb0255e..8d520c5c71c3 100644
--- a/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h
+++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h
@@ -250,12 +250,20 @@ struct rkisp1_buffer {
  *
  * @vb:		vb2 buffer
  * @queue:	entry of the buffer in the queue
+ * @cfg:	scratch buffer used for caching the ISP configuration parameters
  */
 struct rkisp1_params_buffer {
 	struct vb2_v4l2_buffer vb;
 	struct list_head queue;
+	struct rkisp1_params_cfg *cfg;
 };
 
+static inline struct rkisp1_params_buffer *
+to_rkisp1_params_buffer(struct vb2_v4l2_buffer *vbuf)
+{
+	return container_of(vbuf, struct rkisp1_params_buffer, vb);
+}
+
 /*
  * struct rkisp1_dummy_buffer - A buffer to write the next frame to in case
  *				there are no vb2 buffers available.
diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c b/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c
index 2844e55bc4f2..e333cda21fdd 100644
--- a/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c
+++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c
@@ -5,6 +5,8 @@
  * Copyright (C) 2017 Rockchip Electronics Co., Ltd.
  */
 
+#include <linux/string.h>
+
 #include <media/v4l2-common.h>
 #include <media/v4l2-event.h>
 #include <media/v4l2-ioctl.h>
@@ -1501,20 +1503,6 @@ static void rkisp1_isp_isr_meas_config(struct rkisp1_params *params,
 	}
 }
 
-static bool rkisp1_params_get_buffer(struct rkisp1_params *params,
-				     struct rkisp1_params_buffer **buf,
-				     struct rkisp1_params_cfg **cfg)
-{
-	if (list_empty(&params->params))
-		return false;
-
-	*buf = list_first_entry(&params->params, struct rkisp1_params_buffer,
-				queue);
-	*cfg = vb2_plane_vaddr(&(*buf)->vb.vb2_buf, 0);
-
-	return true;
-}
-
 static void rkisp1_params_complete_buffer(struct rkisp1_params *params,
 					  struct rkisp1_params_buffer *buf,
 					  unsigned int frame_sequence)
@@ -1528,17 +1516,18 @@ static void rkisp1_params_complete_buffer(struct rkisp1_params *params,
 void rkisp1_params_isr(struct rkisp1_device *rkisp1)
 {
 	struct rkisp1_params *params = &rkisp1->params;
-	struct rkisp1_params_cfg *new_params;
 	struct rkisp1_params_buffer *cur_buf;
 
 	spin_lock(&params->config_lock);
 
-	if (!rkisp1_params_get_buffer(params, &cur_buf, &new_params))
+	cur_buf = list_first_entry_or_null(&params->params,
+					   struct rkisp1_params_buffer, queue);
+	if (!cur_buf)
 		goto unlock;
 
-	rkisp1_isp_isr_other_config(params, new_params);
-	rkisp1_isp_isr_lsc_config(params, new_params);
-	rkisp1_isp_isr_meas_config(params, new_params);
+	rkisp1_isp_isr_other_config(params, cur_buf->cfg);
+	rkisp1_isp_isr_lsc_config(params, cur_buf->cfg);
+	rkisp1_isp_isr_meas_config(params, cur_buf->cfg);
 
 	/* update shadow register immediately */
 	rkisp1_param_set_bits(params, RKISP1_CIF_ISP_CTRL,
@@ -1604,7 +1593,6 @@ void rkisp1_params_pre_configure(struct rkisp1_params *params,
 				 enum v4l2_ycbcr_encoding ycbcr_encoding)
 {
 	struct rkisp1_cif_isp_hst_config hst = rkisp1_hst_params_default_config;
-	struct rkisp1_params_cfg *new_params;
 	struct rkisp1_params_buffer *cur_buf;
 
 	params->quantization = quantization;
@@ -1634,11 +1622,13 @@ void rkisp1_params_pre_configure(struct rkisp1_params *params,
 
 	/* apply the first buffer if there is one already */
 
-	if (!rkisp1_params_get_buffer(params, &cur_buf, &new_params))
+	cur_buf = list_first_entry_or_null(&params->params,
+					   struct rkisp1_params_buffer, queue);
+	if (!cur_buf)
 		goto unlock;
 
-	rkisp1_isp_isr_other_config(params, new_params);
-	rkisp1_isp_isr_meas_config(params, new_params);
+	rkisp1_isp_isr_other_config(params, cur_buf->cfg);
+	rkisp1_isp_isr_meas_config(params, cur_buf->cfg);
 
 	/* update shadow register immediately */
 	rkisp1_param_set_bits(params, RKISP1_CIF_ISP_CTRL,
@@ -1650,7 +1640,6 @@ void rkisp1_params_pre_configure(struct rkisp1_params *params,
 
 void rkisp1_params_post_configure(struct rkisp1_params *params)
 {
-	struct rkisp1_params_cfg *new_params;
 	struct rkisp1_params_buffer *cur_buf;
 
 	spin_lock_irq(&params->config_lock);
@@ -1663,11 +1652,12 @@ void rkisp1_params_post_configure(struct rkisp1_params *params)
 	 * ordering doesn't affect other ISP versions negatively, do so
 	 * unconditionally.
 	 */
-
-	if (!rkisp1_params_get_buffer(params, &cur_buf, &new_params))
+	cur_buf = list_first_entry_or_null(&params->params,
+					   struct rkisp1_params_buffer, queue);
+	if (!cur_buf)
 		goto unlock;
 
-	rkisp1_isp_isr_lsc_config(params, new_params);
+	rkisp1_isp_isr_lsc_config(params, cur_buf->cfg);
 
 	/* update shadow register immediately */
 	rkisp1_param_set_bits(params, RKISP1_CIF_ISP_CTRL,
@@ -1819,11 +1809,31 @@ static int rkisp1_params_vb2_queue_setup(struct vb2_queue *vq,
 	return 0;
 }
 
+static int rkisp1_params_vb2_buf_init(struct vb2_buffer *vb)
+{
+	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
+	struct rkisp1_params_buffer *params_buf = to_rkisp1_params_buffer(vbuf);
+
+	params_buf->cfg = kvmalloc(sizeof(*params_buf->cfg), GFP_KERNEL);
+	if (!params_buf->cfg)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static void rkisp1_params_vb2_buf_cleanup(struct vb2_buffer *vb)
+{
+	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
+	struct rkisp1_params_buffer *params_buf = to_rkisp1_params_buffer(vbuf);
+
+	kvfree(params_buf->cfg);
+	params_buf->cfg = NULL;
+}
+
 static void rkisp1_params_vb2_buf_queue(struct vb2_buffer *vb)
 {
 	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
-	struct rkisp1_params_buffer *params_buf =
-		container_of(vbuf, struct rkisp1_params_buffer, vb);
+	struct rkisp1_params_buffer *params_buf = to_rkisp1_params_buffer(vbuf);
 	struct vb2_queue *vq = vb->vb2_queue;
 	struct rkisp1_params *params = vq->drv_priv;
 
@@ -1834,10 +1844,19 @@ static void rkisp1_params_vb2_buf_queue(struct vb2_buffer *vb)
 
 static int rkisp1_params_vb2_buf_prepare(struct vb2_buffer *vb)
 {
-	if (vb2_plane_size(vb, 0) < sizeof(struct rkisp1_params_cfg))
+	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
+	struct rkisp1_params_buffer *params_buf = to_rkisp1_params_buffer(vbuf);
+	struct rkisp1_params_cfg *cfg =
+		vb2_plane_vaddr(&params_buf->vb.vb2_buf, 0);
+
+	if (vb2_get_plane_payload(vb, 0) != sizeof(*cfg))
 		return -EINVAL;
 
-	vb2_set_plane_payload(vb, 0, sizeof(struct rkisp1_params_cfg));
+	/*
+	 * Copy the parameters buffer to the internal scratch buffer to avoid
+	 * userspace modifying the buffer content while the driver processes it.
+	 */
+	memcpy(params_buf->cfg, cfg, sizeof(*cfg));
 
 	return 0;
 }
@@ -1863,6 +1882,8 @@ static void rkisp1_params_vb2_stop_streaming(struct vb2_queue *vq)
 
 static const struct vb2_ops rkisp1_params_vb2_ops = {
 	.queue_setup = rkisp1_params_vb2_queue_setup,
+	.buf_init = rkisp1_params_vb2_buf_init,
+	.buf_cleanup = rkisp1_params_vb2_buf_cleanup,
 	.wait_prepare = vb2_ops_wait_prepare,
 	.wait_finish = vb2_ops_wait_finish,
 	.buf_queue = rkisp1_params_vb2_buf_queue,
-- 
2.45.2

[PATCH v7 05/12] media: rkisp1: Cache the currently active format

[Jacopo Mondi]

The rkisp1-params driver assumes the data buffer format is the only
currently supported "fixed" one. The usage of the "fixed" format is
assumed when allocating memory for the scratch buffers and when
initializing the vb2 queue.

In order to prepare to support the "extensible" format beside the
existing "fixed" one, add support in the driver for both formats by
caching a pointer to the active one in the driver structure and use it
in the vb2 queue operations and subdev pad operations implementations.

Do not yet allow userspace to select between the two formats as the
support for the "extensible" format parsing will be introduced in a later
patch in the series.

While at it, document the un-documented ycbcr_encoding field of
struct rkisp1_params_ops.

Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
---
 .../platform/rockchip/rkisp1/rkisp1-common.h  |  8 +--
 .../platform/rockchip/rkisp1/rkisp1-params.c  | 52 ++++++++++++-------
 2 files changed, 38 insertions(+), 22 deletions(-)

diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h b/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h
index 8d520c5c71c3..43cc727a628d 100644
--- a/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h
+++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h
@@ -255,7 +255,7 @@ struct rkisp1_buffer {
 struct rkisp1_params_buffer {
 	struct vb2_v4l2_buffer vb;
 	struct list_head queue;
-	struct rkisp1_params_cfg *cfg;
+	void *cfg;
 };
 
 static inline struct rkisp1_params_buffer *
@@ -392,8 +392,9 @@ struct rkisp1_params_ops {
  * @ops:		pointer to the variant-specific operations
  * @config_lock:	locks the buffer list 'params'
  * @params:		queue of rkisp1_buffer
- * @vdev_fmt:		v4l2_format of the metadata format
+ * @metafmt		the currently enabled metadata format
  * @quantization:	the quantization configured on the isp's src pad
+ * @ycbcr_encoding	the YCbCr encoding
  * @raw_type:		the bayer pattern on the isp video sink pad
  */
 struct rkisp1_params {
@@ -403,7 +404,8 @@ struct rkisp1_params {
 
 	spinlock_t config_lock; /* locks the buffers list 'params' */
 	struct list_head params;
-	struct v4l2_format vdev_fmt;
+
+	const struct v4l2_meta_format *metafmt;
 
 	enum v4l2_quantization quantization;
 	enum v4l2_ycbcr_encoding ycbcr_encoding;
diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c b/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c
index e333cda21fdd..45c4b1bcee63 100644
--- a/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c
+++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c
@@ -35,6 +35,22 @@
 #define RKISP1_ISP_CC_COEFF(n) \
 			(RKISP1_CIF_ISP_CC_COEFF_0 + (n) * 4)
 
+enum rkisp1_params_formats {
+	RKISP1_PARAMS_FIXED,
+	RKISP1_PARAMS_EXTENSIBLE,
+};
+
+static const struct v4l2_meta_format rkisp1_params_formats[] = {
+	[RKISP1_PARAMS_FIXED] = {
+		.dataformat = V4L2_META_FMT_RK_ISP1_PARAMS,
+		.buffersize = sizeof(struct rkisp1_params_cfg),
+	},
+	[RKISP1_PARAMS_EXTENSIBLE] = {
+		.dataformat = V4L2_META_FMT_RK_ISP1_EXT_PARAMS,
+		.buffersize = sizeof(struct rkisp1_ext_params_cfg),
+	},
+};
+
 static inline void
 rkisp1_param_set_bits(struct rkisp1_params *params, u32 reg, u32 bit_mask)
 {
@@ -1738,7 +1754,7 @@ static int rkisp1_params_enum_fmt_meta_out(struct file *file, void *priv,
 	if (f->index > 0 || f->type != video->queue->type)
 		return -EINVAL;
 
-	f->pixelformat = params->vdev_fmt.fmt.meta.dataformat;
+	f->pixelformat = params->metafmt->dataformat;
 
 	return 0;
 }
@@ -1754,8 +1770,8 @@ static int rkisp1_params_g_fmt_meta_out(struct file *file, void *fh,
 		return -EINVAL;
 
 	memset(meta, 0, sizeof(*meta));
-	meta->dataformat = params->vdev_fmt.fmt.meta.dataformat;
-	meta->buffersize = params->vdev_fmt.fmt.meta.buffersize;
+	meta->dataformat = params->metafmt->dataformat;
+	meta->buffersize = params->metafmt->buffersize;
 
 	return 0;
 }
@@ -1798,13 +1814,15 @@ static int rkisp1_params_vb2_queue_setup(struct vb2_queue *vq,
 					 unsigned int sizes[],
 					 struct device *alloc_devs[])
 {
+	struct rkisp1_params *params = vq->drv_priv;
+
 	*num_buffers = clamp_t(u32, *num_buffers,
 			       RKISP1_ISP_PARAMS_REQ_BUFS_MIN,
 			       RKISP1_ISP_PARAMS_REQ_BUFS_MAX);
 
 	*num_planes = 1;
 
-	sizes[0] = sizeof(struct rkisp1_params_cfg);
+	sizes[0] = params->metafmt->buffersize;
 
 	return 0;
 }
@@ -1813,8 +1831,10 @@ static int rkisp1_params_vb2_buf_init(struct vb2_buffer *vb)
 {
 	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
 	struct rkisp1_params_buffer *params_buf = to_rkisp1_params_buffer(vbuf);
+	struct rkisp1_params *params = vb->vb2_queue->drv_priv;
 
-	params_buf->cfg = kvmalloc(sizeof(*params_buf->cfg), GFP_KERNEL);
+	params_buf->cfg = kvmalloc(params->metafmt->buffersize,
+				   GFP_KERNEL);
 	if (!params_buf->cfg)
 		return -ENOMEM;
 
@@ -1919,19 +1939,6 @@ static int rkisp1_params_init_vb2_queue(struct vb2_queue *q,
 	return vb2_queue_init(q);
 }
 
-static void rkisp1_init_params(struct rkisp1_params *params)
-{
-	params->vdev_fmt.fmt.meta.dataformat =
-		V4L2_META_FMT_RK_ISP1_PARAMS;
-	params->vdev_fmt.fmt.meta.buffersize =
-		sizeof(struct rkisp1_params_cfg);
-
-	if (params->rkisp1->info->isp_ver == RKISP1_V12)
-		params->ops = &rkisp1_v12_params_ops;
-	else
-		params->ops = &rkisp1_v10_params_ops;
-}
-
 int rkisp1_params_register(struct rkisp1_device *rkisp1)
 {
 	struct rkisp1_params *params = &rkisp1->params;
@@ -1960,7 +1967,14 @@ int rkisp1_params_register(struct rkisp1_device *rkisp1)
 	vdev->device_caps = V4L2_CAP_STREAMING | V4L2_CAP_META_OUTPUT;
 	vdev->vfl_dir = VFL_DIR_TX;
 	rkisp1_params_init_vb2_queue(vdev->queue, params);
-	rkisp1_init_params(params);
+
+	params->metafmt = &rkisp1_params_formats[RKISP1_PARAMS_FIXED];
+
+	if (params->rkisp1->info->isp_ver == RKISP1_V12)
+		params->ops = &rkisp1_v12_params_ops;
+	else
+		params->ops = &rkisp1_v10_params_ops;
+
 	video_set_drvdata(vdev, params);
 
 	node->pad.flags = MEDIA_PAD_FL_SOURCE;
-- 
2.45.2

[PATCH v7 06/12] media: rkisp1: Implement extensible params support

[Jacopo Mondi]

Implement support in rkisp1-params for the extensible configuration
parameters format.

Create a list of handlers for each ISP block that wraps the existing
configuration functions and handles the ISP block enablement.

Parse the configuration parameters buffer in rkisp1_ext_params_config
and filter the enable blocks by group, to allow setting the 'other'
groups separately from the 'lsc' group to support the pre/post-configure
operations.

Implement parameter buffer validation for the extensible format at
.buf_prepare() time.

Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
---
 .../platform/rockchip/rkisp1/rkisp1-common.h  |   3 +
 .../platform/rockchip/rkisp1/rkisp1-params.c  | 605 +++++++++++++++++-
 2 files changed, 597 insertions(+), 11 deletions(-)

diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h b/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h
index 43cc727a628d..2f4bf7e97927 100644
--- a/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h
+++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h
@@ -396,6 +396,7 @@ struct rkisp1_params_ops {
  * @quantization:	the quantization configured on the isp's src pad
  * @ycbcr_encoding	the YCbCr encoding
  * @raw_type:		the bayer pattern on the isp video sink pad
+ * @enabled_blocks:	bitmask of enabled ISP blocks
  */
 struct rkisp1_params {
 	struct rkisp1_vdev_node vnode;
@@ -410,6 +411,8 @@ struct rkisp1_params {
 	enum v4l2_quantization quantization;
 	enum v4l2_ycbcr_encoding ycbcr_encoding;
 	enum rkisp1_fmt_raw_pat_type raw_type;
+
+	u32 enabled_blocks;
 };
 
 /*
diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c b/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c
index 45c4b1bcee63..1c84b82f26b1 100644
--- a/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c
+++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c
@@ -35,6 +35,30 @@
 #define RKISP1_ISP_CC_COEFF(n) \
 			(RKISP1_CIF_ISP_CC_COEFF_0 + (n) * 4)
 
+#define RKISP1_EXT_PARAMS_BLOCK_GROUP_OTHERS	BIT(0)
+#define RKISP1_EXT_PARAMS_BLOCK_GROUP_LSC	BIT(1)
+
+union rkisp1_ext_params_config {
+	struct rkisp1_ext_params_block_header header;
+	struct rkisp1_ext_params_bls_config bls;
+	struct rkisp1_ext_params_dpcc_config dpcc;
+	struct rkisp1_ext_params_sdg_config sdg;
+	struct rkisp1_ext_params_lsc_config lsc;
+	struct rkisp1_ext_params_awb_gain_config awbg;
+	struct rkisp1_ext_params_flt_config flt;
+	struct rkisp1_ext_params_bdm_config bdm;
+	struct rkisp1_ext_params_ctk_config ctk;
+	struct rkisp1_ext_params_goc_config goc;
+	struct rkisp1_ext_params_dpf_config dpf;
+	struct rkisp1_ext_params_dpf_strength_config dpfs;
+	struct rkisp1_ext_params_cproc_config cproc;
+	struct rkisp1_ext_params_ie_config ie;
+	struct rkisp1_ext_params_awb_meas_config awbm;
+	struct rkisp1_ext_params_hst_config hst;
+	struct rkisp1_ext_params_aec_config aec;
+	struct rkisp1_ext_params_afc_config afc;
+};
+
 enum rkisp1_params_formats {
 	RKISP1_PARAMS_FIXED,
 	RKISP1_PARAMS_EXTENSIBLE,
@@ -1519,6 +1543,454 @@ static void rkisp1_isp_isr_meas_config(struct rkisp1_params *params,
 	}
 }
 
+/*------------------------------------------------------------------------------
+ * Extensible parameters format handling
+ */
+
+static void
+rkisp1_ext_params_bls(struct rkisp1_params *params,
+		      const union rkisp1_ext_params_config *block)
+{
+	const struct rkisp1_ext_params_bls_config *bls = &block->bls;
+
+	if (bls->header.enable == RKISP1_EXT_PARAMS_BLOCK_DISABLE) {
+		rkisp1_param_clear_bits(params, RKISP1_CIF_ISP_BLS_CTRL,
+					RKISP1_CIF_ISP_BLS_ENA);
+		return;
+	}
+
+	rkisp1_bls_config(params, &bls->config);
+
+	if (!(params->enabled_blocks & BIT(RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS)))
+		rkisp1_param_set_bits(params, RKISP1_CIF_ISP_BLS_CTRL,
+				      RKISP1_CIF_ISP_BLS_ENA);
+}
+
+static void
+rkisp1_ext_params_dpcc(struct rkisp1_params *params,
+		       const union rkisp1_ext_params_config *block)
+{
+	const struct rkisp1_ext_params_dpcc_config *dpcc = &block->dpcc;
+
+	if (dpcc->header.enable == RKISP1_EXT_PARAMS_BLOCK_DISABLE) {
+		rkisp1_param_clear_bits(params, RKISP1_CIF_ISP_DPCC_MODE,
+					RKISP1_CIF_ISP_DPCC_MODE_DPCC_ENABLE);
+		return;
+	}
+
+	rkisp1_dpcc_config(params, &dpcc->config);
+
+	if (!(params->enabled_blocks &
+	      BIT(RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC)))
+		rkisp1_param_set_bits(params, RKISP1_CIF_ISP_DPCC_MODE,
+				      RKISP1_CIF_ISP_DPCC_MODE_DPCC_ENABLE);
+}
+
+static void
+rkisp1_ext_params_sdg(struct rkisp1_params *params,
+		      const union rkisp1_ext_params_config *block)
+{
+	const struct rkisp1_ext_params_sdg_config *sdg = &block->sdg;
+
+	if (block->header.enable == RKISP1_EXT_PARAMS_BLOCK_DISABLE) {
+		rkisp1_param_clear_bits(params, RKISP1_CIF_ISP_CTRL,
+					RKISP1_CIF_ISP_CTRL_ISP_GAMMA_IN_ENA);
+		return;
+	}
+
+	rkisp1_sdg_config(params, &sdg->config);
+
+	if (!(params->enabled_blocks & BIT(RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG)))
+		rkisp1_param_set_bits(params, RKISP1_CIF_ISP_CTRL,
+				      RKISP1_CIF_ISP_CTRL_ISP_GAMMA_IN_ENA);
+}
+
+static void
+rkisp1_ext_params_lsc(struct rkisp1_params *params,
+		      const union rkisp1_ext_params_config *block)
+{
+	const struct rkisp1_ext_params_lsc_config *lsc = &block->lsc;
+
+	if (block->header.enable == RKISP1_EXT_PARAMS_BLOCK_DISABLE) {
+		rkisp1_param_clear_bits(params, RKISP1_CIF_ISP_LSC_CTRL,
+					RKISP1_CIF_ISP_LSC_CTRL_ENA);
+		return;
+	}
+
+	rkisp1_lsc_config(params, &lsc->config);
+
+	if (!(params->enabled_blocks & BIT(RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC)))
+		rkisp1_param_set_bits(params, RKISP1_CIF_ISP_LSC_CTRL,
+				      RKISP1_CIF_ISP_LSC_CTRL_ENA);
+}
+
+static void
+rkisp1_ext_params_awbg(struct rkisp1_params *params,
+		       const union rkisp1_ext_params_config *block)
+{
+	const struct rkisp1_ext_params_awb_gain_config *awbg = &block->awbg;
+
+	if (block->header.enable == RKISP1_EXT_PARAMS_BLOCK_DISABLE) {
+		rkisp1_param_clear_bits(params, RKISP1_CIF_ISP_CTRL,
+					RKISP1_CIF_ISP_CTRL_ISP_AWB_ENA);
+		return;
+	}
+
+	params->ops->awb_gain_config(params, &awbg->config);
+
+	if (!(params->enabled_blocks &
+	      BIT(RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN)))
+		rkisp1_param_set_bits(params, RKISP1_CIF_ISP_CTRL,
+				      RKISP1_CIF_ISP_CTRL_ISP_AWB_ENA);
+}
+
+static void
+rkisp1_ext_params_flt(struct rkisp1_params *params,
+		      const union rkisp1_ext_params_config *block)
+{
+	const struct rkisp1_ext_params_flt_config *flt = &block->flt;
+
+	if (block->header.enable == RKISP1_EXT_PARAMS_BLOCK_DISABLE) {
+		rkisp1_param_clear_bits(params, RKISP1_CIF_ISP_FILT_MODE,
+					RKISP1_CIF_ISP_FLT_ENA);
+		return;
+	}
+
+	rkisp1_flt_config(params, &flt->config);
+
+	if (!(params->enabled_blocks & BIT(RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT)))
+		rkisp1_param_set_bits(params, RKISP1_CIF_ISP_FILT_MODE,
+				      RKISP1_CIF_ISP_FLT_ENA);
+}
+
+static void
+rkisp1_ext_params_bdm(struct rkisp1_params *params,
+		      const union rkisp1_ext_params_config *block)
+{
+	const struct rkisp1_ext_params_bdm_config *bdm = &block->bdm;
+
+	if (block->header.enable == RKISP1_EXT_PARAMS_BLOCK_DISABLE) {
+		rkisp1_param_clear_bits(params, RKISP1_CIF_ISP_DEMOSAIC,
+					RKISP1_CIF_ISP_DEMOSAIC_BYPASS);
+		return;
+	}
+
+	rkisp1_bdm_config(params, &bdm->config);
+
+	if (!(params->enabled_blocks & BIT(RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM)))
+		rkisp1_param_set_bits(params, RKISP1_CIF_ISP_DEMOSAIC,
+				      RKISP1_CIF_ISP_DEMOSAIC_BYPASS);
+}
+
+static void
+rkisp1_ext_params_ctk(struct rkisp1_params *params,
+		      const union rkisp1_ext_params_config *block)
+{
+	const struct rkisp1_ext_params_ctk_config *ctk = &block->ctk;
+
+	if (block->header.enable == RKISP1_EXT_PARAMS_BLOCK_DISABLE) {
+		rkisp1_ctk_enable(params, false);
+		return;
+	}
+
+	rkisp1_ctk_config(params, &ctk->config);
+
+	if (!(params->enabled_blocks & BIT(RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK)))
+		rkisp1_ctk_enable(params, true);
+}
+
+static void
+rkisp1_ext_params_goc(struct rkisp1_params *params,
+		      const union rkisp1_ext_params_config *block)
+{
+	const struct rkisp1_ext_params_goc_config *goc = &block->goc;
+
+	if (block->header.enable == RKISP1_EXT_PARAMS_BLOCK_DISABLE) {
+		rkisp1_param_clear_bits(params, RKISP1_CIF_ISP_CTRL,
+					RKISP1_CIF_ISP_CTRL_ISP_GAMMA_OUT_ENA);
+		return;
+	}
+
+	params->ops->goc_config(params, &goc->config);
+
+	/*
+	 * Unconditionally re-enable the GOC module which gets disabled by
+	 * goc_config().
+	 */
+	rkisp1_param_set_bits(params, RKISP1_CIF_ISP_CTRL,
+			      RKISP1_CIF_ISP_CTRL_ISP_GAMMA_OUT_ENA);
+}
+
+static void
+rkisp1_ext_params_dpf(struct rkisp1_params *params,
+		      const union rkisp1_ext_params_config *block)
+{
+	const struct rkisp1_ext_params_dpf_config *dpf = &block->dpf;
+
+	if (block->header.enable == RKISP1_EXT_PARAMS_BLOCK_DISABLE) {
+		rkisp1_param_clear_bits(params, RKISP1_CIF_ISP_DPF_MODE,
+					RKISP1_CIF_ISP_DPF_MODE_EN);
+		return;
+	}
+
+	rkisp1_dpf_config(params, &dpf->config);
+
+	if (!(params->enabled_blocks & BIT(RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF)))
+		rkisp1_param_set_bits(params, RKISP1_CIF_ISP_DPF_MODE,
+				      RKISP1_CIF_ISP_DPF_MODE_EN);
+}
+
+static void
+rkisp1_ext_params_dpfs(struct rkisp1_params *params,
+		       const union rkisp1_ext_params_config *block)
+{
+	const struct rkisp1_ext_params_dpf_strength_config *dpfs = &block->dpfs;
+
+	rkisp1_dpf_strength_config(params, &dpfs->config);
+}
+
+static void
+rkisp1_ext_params_cproc(struct rkisp1_params *params,
+			const union rkisp1_ext_params_config *block)
+{
+	const struct rkisp1_ext_params_cproc_config *cproc = &block->cproc;
+
+	if (block->header.enable == RKISP1_EXT_PARAMS_BLOCK_DISABLE) {
+		rkisp1_param_clear_bits(params, RKISP1_CIF_C_PROC_CTRL,
+					RKISP1_CIF_C_PROC_CTR_ENABLE);
+		return;
+	}
+
+	rkisp1_cproc_config(params, &cproc->config);
+
+	if (!(params->enabled_blocks &
+	      BIT(RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC)))
+		rkisp1_param_set_bits(params, RKISP1_CIF_C_PROC_CTRL,
+				      RKISP1_CIF_C_PROC_CTR_ENABLE);
+}
+
+static void
+rkisp1_ext_params_ie(struct rkisp1_params *params,
+		     const union rkisp1_ext_params_config *block)
+{
+	const struct rkisp1_ext_params_ie_config *ie = &block->ie;
+
+	if (block->header.enable == RKISP1_EXT_PARAMS_BLOCK_DISABLE) {
+		rkisp1_ie_enable(params, false);
+		return;
+	}
+
+	rkisp1_ie_config(params, &ie->config);
+
+	if (!(params->enabled_blocks & BIT(RKISP1_EXT_PARAMS_BLOCK_TYPE_IE)))
+		rkisp1_ie_enable(params, true);
+}
+
+static void
+rkisp1_ext_params_awbm(struct rkisp1_params *params,
+		       const union rkisp1_ext_params_config *block)
+{
+	const struct rkisp1_ext_params_awb_meas_config *awbm = &block->awbm;
+
+	if (block->header.enable == RKISP1_EXT_PARAMS_BLOCK_DISABLE) {
+		params->ops->awb_meas_enable(params, &awbm->config,
+					     false);
+		return;
+	}
+
+	params->ops->awb_meas_config(params, &awbm->config);
+
+	if (!(params->enabled_blocks &
+	      BIT(RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS)))
+		params->ops->awb_meas_enable(params, &awbm->config,
+					     true);
+}
+
+static void
+rkisp1_ext_params_hstm(struct rkisp1_params *params,
+		       const union rkisp1_ext_params_config *block)
+{
+	const struct rkisp1_ext_params_hst_config *hst = &block->hst;
+
+	if (block->header.enable == RKISP1_EXT_PARAMS_BLOCK_DISABLE) {
+		params->ops->hst_enable(params, &hst->config, false);
+		return;
+	}
+
+	params->ops->hst_config(params, &hst->config);
+
+	if (!(params->enabled_blocks &
+	      BIT(RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS)))
+		params->ops->hst_enable(params, &hst->config, true);
+}
+
+static void
+rkisp1_ext_params_aecm(struct rkisp1_params *params,
+		       const union rkisp1_ext_params_config *block)
+{
+	const struct rkisp1_ext_params_aec_config *aec = &block->aec;
+
+	if (block->header.enable == RKISP1_EXT_PARAMS_BLOCK_DISABLE) {
+		rkisp1_param_clear_bits(params, RKISP1_CIF_ISP_EXP_CTRL,
+					RKISP1_CIF_ISP_EXP_ENA);
+		return;
+	}
+
+	params->ops->aec_config(params, &aec->config);
+
+	if (!(params->enabled_blocks &
+	      BIT(RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS)))
+		rkisp1_param_set_bits(params, RKISP1_CIF_ISP_EXP_CTRL,
+				      RKISP1_CIF_ISP_EXP_ENA);
+}
+
+static void
+rkisp1_ext_params_afcm(struct rkisp1_params *params,
+		       const union rkisp1_ext_params_config *block)
+{
+	const struct rkisp1_ext_params_afc_config *afc = &block->afc;
+
+	if (block->header.enable == RKISP1_EXT_PARAMS_BLOCK_DISABLE) {
+		rkisp1_param_clear_bits(params, RKISP1_CIF_ISP_AFM_CTRL,
+					RKISP1_CIF_ISP_AFM_ENA);
+		return;
+	}
+
+	params->ops->afm_config(params, &afc->config);
+
+	if (!(params->enabled_blocks &
+	      BIT(RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS)))
+		rkisp1_param_set_bits(params, RKISP1_CIF_ISP_AFM_CTRL,
+				      RKISP1_CIF_ISP_AFM_ENA);
+}
+
+typedef void (*rkisp1_block_handler)(struct rkisp1_params *params,
+			     const union rkisp1_ext_params_config *config);
+
+static const struct rkisp1_ext_params_handler {
+	size_t size;
+	rkisp1_block_handler handler;
+	unsigned int group;
+} rkisp1_ext_params_handlers[] = {
+	[RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS] = {
+		.size		= sizeof(struct rkisp1_ext_params_bls_config),
+		.handler	= rkisp1_ext_params_bls,
+		.group		= RKISP1_EXT_PARAMS_BLOCK_GROUP_OTHERS,
+	},
+	[RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC] = {
+		.size		= sizeof(struct rkisp1_ext_params_dpcc_config),
+		.handler	= rkisp1_ext_params_dpcc,
+		.group		= RKISP1_EXT_PARAMS_BLOCK_GROUP_OTHERS,
+	},
+	[RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG] = {
+		.size		= sizeof(struct rkisp1_ext_params_sdg_config),
+		.handler	= rkisp1_ext_params_sdg,
+		.group		= RKISP1_EXT_PARAMS_BLOCK_GROUP_OTHERS,
+	},
+	[RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN] = {
+		.size		= sizeof(struct rkisp1_ext_params_awb_gain_config),
+		.handler	= rkisp1_ext_params_awbg,
+		.group		= RKISP1_EXT_PARAMS_BLOCK_GROUP_OTHERS,
+	},
+	[RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT] = {
+		.size		= sizeof(struct rkisp1_ext_params_flt_config),
+		.handler	= rkisp1_ext_params_flt,
+		.group		= RKISP1_EXT_PARAMS_BLOCK_GROUP_OTHERS,
+	},
+	[RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM] = {
+		.size		= sizeof(struct rkisp1_ext_params_bdm_config),
+		.handler	= rkisp1_ext_params_bdm,
+		.group		= RKISP1_EXT_PARAMS_BLOCK_GROUP_OTHERS,
+	},
+	[RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK] = {
+		.size		= sizeof(struct rkisp1_ext_params_ctk_config),
+		.handler	= rkisp1_ext_params_ctk,
+		.group		= RKISP1_EXT_PARAMS_BLOCK_GROUP_OTHERS,
+	},
+	[RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC] = {
+		.size		= sizeof(struct rkisp1_ext_params_goc_config),
+		.handler	= rkisp1_ext_params_goc,
+		.group		= RKISP1_EXT_PARAMS_BLOCK_GROUP_OTHERS,
+	},
+	[RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF] = {
+		.size		= sizeof(struct rkisp1_ext_params_dpf_config),
+		.handler	= rkisp1_ext_params_dpf,
+		.group		= RKISP1_EXT_PARAMS_BLOCK_GROUP_OTHERS,
+	},
+	[RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH] = {
+		.size		= sizeof(struct rkisp1_ext_params_dpf_strength_config),
+		.handler	= rkisp1_ext_params_dpfs,
+		.group		= RKISP1_EXT_PARAMS_BLOCK_GROUP_OTHERS,
+	},
+	[RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC] = {
+		.size		= sizeof(struct rkisp1_ext_params_cproc_config),
+		.handler	= rkisp1_ext_params_cproc,
+		.group		= RKISP1_EXT_PARAMS_BLOCK_GROUP_OTHERS,
+	},
+	[RKISP1_EXT_PARAMS_BLOCK_TYPE_IE] = {
+		.size		= sizeof(struct rkisp1_ext_params_ie_config),
+		.handler	= rkisp1_ext_params_ie,
+		.group		= RKISP1_EXT_PARAMS_BLOCK_GROUP_OTHERS,
+	},
+	[RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC] = {
+		.size		= sizeof(struct rkisp1_ext_params_lsc_config),
+		.handler	= rkisp1_ext_params_lsc,
+		.group		= RKISP1_EXT_PARAMS_BLOCK_GROUP_LSC,
+	},
+	[RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS] = {
+		.size		= sizeof(struct rkisp1_ext_params_awb_meas_config),
+		.handler	= rkisp1_ext_params_awbm,
+		.group		= RKISP1_EXT_PARAMS_BLOCK_GROUP_OTHERS,
+	},
+	[RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS] = {
+		.size		= sizeof(struct rkisp1_ext_params_hst_config),
+		.handler	= rkisp1_ext_params_hstm,
+		.group		= RKISP1_EXT_PARAMS_BLOCK_GROUP_OTHERS,
+	},
+	[RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS] = {
+		.size		= sizeof(struct rkisp1_ext_params_aec_config),
+		.handler	= rkisp1_ext_params_aecm,
+		.group		= RKISP1_EXT_PARAMS_BLOCK_GROUP_OTHERS,
+	},
+	[RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS] = {
+		.size		= sizeof(struct rkisp1_ext_params_afc_config),
+		.handler	= rkisp1_ext_params_afcm,
+		.group		= RKISP1_EXT_PARAMS_BLOCK_GROUP_OTHERS,
+	},
+};
+
+static void rkisp1_ext_params_config(struct rkisp1_params *params,
+				     struct rkisp1_ext_params_cfg *cfg,
+				     u32 block_group_mask)
+{
+	size_t block_offset = 0;
+
+	if (WARN_ON(!cfg))
+		return;
+
+	/* Walk the list of parameter blocks and process them. */
+	while (block_offset < cfg->data_size) {
+		const struct rkisp1_ext_params_handler *block_handler;
+		const union rkisp1_ext_params_config *block;
+
+		block = (const union rkisp1_ext_params_config *)
+			&cfg->data[block_offset];
+		block_offset += block->header.size;
+
+		/* Make sure the block is in the list of groups to configure. */
+		block_handler = &rkisp1_ext_params_handlers[block->header.type];
+		if (!(block_handler->group & block_group_mask))
+			continue;
+
+		block_handler->handler(params, block);
+
+		if (block->header.enable == RKISP1_EXT_PARAMS_BLOCK_DISABLE)
+			params->enabled_blocks &= ~BIT(block->header.type);
+		else
+			params->enabled_blocks |= BIT(block->header.type);
+	}
+}
+
 static void rkisp1_params_complete_buffer(struct rkisp1_params *params,
 					  struct rkisp1_params_buffer *buf,
 					  unsigned int frame_sequence)
@@ -1541,9 +2013,15 @@ void rkisp1_params_isr(struct rkisp1_device *rkisp1)
 	if (!cur_buf)
 		goto unlock;
 
-	rkisp1_isp_isr_other_config(params, cur_buf->cfg);
-	rkisp1_isp_isr_lsc_config(params, cur_buf->cfg);
-	rkisp1_isp_isr_meas_config(params, cur_buf->cfg);
+	if (params->metafmt->dataformat == V4L2_META_FMT_RK_ISP1_PARAMS) {
+		rkisp1_isp_isr_other_config(params, cur_buf->cfg);
+		rkisp1_isp_isr_lsc_config(params, cur_buf->cfg);
+		rkisp1_isp_isr_meas_config(params, cur_buf->cfg);
+	} else {
+		rkisp1_ext_params_config(params, cur_buf->cfg,
+					 RKISP1_EXT_PARAMS_BLOCK_GROUP_OTHERS |
+					 RKISP1_EXT_PARAMS_BLOCK_GROUP_LSC);
+	}
 
 	/* update shadow register immediately */
 	rkisp1_param_set_bits(params, RKISP1_CIF_ISP_CTRL,
@@ -1643,8 +2121,13 @@ void rkisp1_params_pre_configure(struct rkisp1_params *params,
 	if (!cur_buf)
 		goto unlock;
 
-	rkisp1_isp_isr_other_config(params, cur_buf->cfg);
-	rkisp1_isp_isr_meas_config(params, cur_buf->cfg);
+	if (params->metafmt->dataformat == V4L2_META_FMT_RK_ISP1_PARAMS) {
+		rkisp1_isp_isr_other_config(params, cur_buf->cfg);
+		rkisp1_isp_isr_meas_config(params, cur_buf->cfg);
+	} else {
+		rkisp1_ext_params_config(params, cur_buf->cfg,
+					 RKISP1_EXT_PARAMS_BLOCK_GROUP_OTHERS);
+	}
 
 	/* update shadow register immediately */
 	rkisp1_param_set_bits(params, RKISP1_CIF_ISP_CTRL,
@@ -1673,7 +2156,11 @@ void rkisp1_params_post_configure(struct rkisp1_params *params)
 	if (!cur_buf)
 		goto unlock;
 
-	rkisp1_isp_isr_lsc_config(params, cur_buf->cfg);
+	if (params->metafmt->dataformat == V4L2_META_FMT_RK_ISP1_PARAMS)
+		rkisp1_isp_isr_lsc_config(params, cur_buf->cfg);
+	else
+		rkisp1_ext_params_config(params, cur_buf->cfg,
+					 RKISP1_EXT_PARAMS_BLOCK_GROUP_LSC);
 
 	/* update shadow register immediately */
 	rkisp1_param_set_bits(params, RKISP1_CIF_ISP_CTRL,
@@ -1862,21 +2349,116 @@ static void rkisp1_params_vb2_buf_queue(struct vb2_buffer *vb)
 	spin_unlock_irq(&params->config_lock);
 }
 
+static int rkisp1_params_prepare_ext_params(struct rkisp1_params *params,
+					    struct vb2_buffer *vb)
+{
+	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
+	struct rkisp1_params_buffer *params_buf = to_rkisp1_params_buffer(vbuf);
+	size_t header_size = offsetof(struct rkisp1_ext_params_cfg, data);
+	struct rkisp1_ext_params_cfg *cfg = params_buf->cfg;
+	size_t payload_size = vb2_get_plane_payload(vb, 0);
+	struct rkisp1_ext_params_cfg *usr_cfg =
+		vb2_plane_vaddr(&vbuf->vb2_buf, 0);
+	size_t block_offset = 0;
+	size_t cfg_size;
+
+	/*
+	 * Validate the buffer payload size before copying the parameters. The
+	 * payload has to be smaller than the destination buffer size and larger
+	 * than the header size.
+	 */
+	if (payload_size > params->metafmt->buffersize) {
+		dev_dbg(params->rkisp1->dev,
+			"Too large buffer payload size %lu\n", payload_size);
+		return -EINVAL;
+	}
+
+	if (payload_size < header_size) {
+		dev_dbg(params->rkisp1->dev,
+			"Buffer payload %lu smaller than header size %lu\n",
+			payload_size, header_size);
+		return -EINVAL;
+	}
+
+	/*
+	 * Copy the parameters buffer to the internal scratch buffer to avoid
+	 * userspace modifying the buffer content while the driver processes it.
+	 */
+	memcpy(cfg, usr_cfg, payload_size);
+
+	/* Validate the size reported in the parameters buffer header. */
+	cfg_size = header_size + cfg->data_size;
+	if (cfg_size != payload_size) {
+		dev_dbg(params->rkisp1->dev,
+			"Data size %lu different than buffer payload size %lu\n",
+			cfg_size, payload_size);
+		return -EINVAL;
+	}
+
+	/* Walk the list of parameter blocks and validate them. */
+	cfg_size = cfg->data_size;
+	while (cfg_size >= sizeof(struct rkisp1_ext_params_block_header)) {
+		const struct rkisp1_ext_params_block_header *block;
+		const struct rkisp1_ext_params_handler *handler;
+
+		block = (const struct rkisp1_ext_params_block_header *)
+			&cfg->data[block_offset];
+
+		if (block->type >= ARRAY_SIZE(rkisp1_ext_params_handlers)) {
+			dev_dbg(params->rkisp1->dev,
+				"Invalid parameters block type\n");
+			return -EINVAL;
+		}
+
+		if (block->size > cfg_size) {
+			dev_dbg(params->rkisp1->dev,
+				"Premature end of parameters data\n");
+			return -EINVAL;
+		}
+
+		handler = &rkisp1_ext_params_handlers[block->type];
+		if (block->size != handler->size) {
+			dev_dbg(params->rkisp1->dev,
+				"Invalid parameters block size\n");
+			return -EINVAL;
+		}
+
+		block_offset += block->size;
+		cfg_size -= block->size;
+	}
+
+	if (cfg_size) {
+		dev_dbg(params->rkisp1->dev,
+			"Unexpected data after the parameters buffer end\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 static int rkisp1_params_vb2_buf_prepare(struct vb2_buffer *vb)
 {
+	struct rkisp1_params *params = vb->vb2_queue->drv_priv;
 	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
 	struct rkisp1_params_buffer *params_buf = to_rkisp1_params_buffer(vbuf);
-	struct rkisp1_params_cfg *cfg =
-		vb2_plane_vaddr(&params_buf->vb.vb2_buf, 0);
+	struct rkisp1_params_cfg *cfg = vb2_plane_vaddr(&vbuf->vb2_buf, 0);
+	size_t payload = vb2_get_plane_payload(vb, 0);
 
-	if (vb2_get_plane_payload(vb, 0) != sizeof(*cfg))
+	if (params->metafmt->dataformat == V4L2_META_FMT_RK_ISP1_EXT_PARAMS)
+		return rkisp1_params_prepare_ext_params(params, vb);
+
+	/*
+	 * For the fixed parameters format the payload size must be exactly the
+	 * size of the parameters structure.
+	 */
+	if (payload != sizeof(*cfg))
 		return -EINVAL;
 
 	/*
 	 * Copy the parameters buffer to the internal scratch buffer to avoid
 	 * userspace modifying the buffer content while the driver processes it.
 	 */
-	memcpy(params_buf->cfg, cfg, sizeof(*cfg));
+	memcpy(params_buf->cfg, cfg, payload);
 
 	return 0;
 }
@@ -1898,6 +2480,8 @@ static void rkisp1_params_vb2_stop_streaming(struct vb2_queue *vq)
 
 	list_for_each_entry(buf, &tmp_list, queue)
 		vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
+
+	params->enabled_blocks = 0;
 }
 
 static const struct vb2_ops rkisp1_params_vb2_ops = {
@@ -1909,7 +2493,6 @@ static const struct vb2_ops rkisp1_params_vb2_ops = {
 	.buf_queue = rkisp1_params_vb2_buf_queue,
 	.buf_prepare = rkisp1_params_vb2_buf_prepare,
 	.stop_streaming = rkisp1_params_vb2_stop_streaming,
-
 };
 
 static const struct v4l2_file_operations rkisp1_params_fops = {
-- 
2.45.2

[PATCH v7 07/12] media: rkisp1: Implement s_fmt/try_fmt

[Jacopo Mondi]

Implement in the rkisp1 driver support for the s_fmt and try_fmt
operation to allow userspace to select between the extensible
and the fixed parameters formats.

Implement enum_mbus_code to enumerate the fixed and the extensible
formats and disallow changing the data format while the queue is busy.

Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
---
 .../platform/rockchip/rkisp1/rkisp1-params.c  | 58 ++++++++++++++++---
 1 file changed, 50 insertions(+), 8 deletions(-)

diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c b/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c
index 1c84b82f26b1..d0e3974a8098 100644
--- a/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c
+++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c
@@ -75,6 +75,17 @@ static const struct v4l2_meta_format rkisp1_params_formats[] = {
 	},
 };
 
+static const struct v4l2_meta_format *
+rkisp1_params_get_format_info(u32 dataformat)
+{
+	for (unsigned int i = 0; i < ARRAY_SIZE(rkisp1_params_formats); i++) {
+		if (rkisp1_params_formats[i].dataformat == dataformat)
+			return &rkisp1_params_formats[i];
+	}
+
+	return &rkisp1_params_formats[RKISP1_PARAMS_FIXED];
+}
+
 static inline void
 rkisp1_param_set_bits(struct rkisp1_params *params, u32 reg, u32 bit_mask)
 {
@@ -2236,12 +2247,12 @@ static int rkisp1_params_enum_fmt_meta_out(struct file *file, void *priv,
 					   struct v4l2_fmtdesc *f)
 {
 	struct video_device *video = video_devdata(file);
-	struct rkisp1_params *params = video_get_drvdata(video);
 
-	if (f->index > 0 || f->type != video->queue->type)
+	if (f->index >= ARRAY_SIZE(rkisp1_params_formats) ||
+	    f->type != video->queue->type)
 		return -EINVAL;
 
-	f->pixelformat = params->metafmt->dataformat;
+	f->pixelformat = rkisp1_params_formats[f->index].dataformat;
 
 	return 0;
 }
@@ -2256,9 +2267,40 @@ static int rkisp1_params_g_fmt_meta_out(struct file *file, void *fh,
 	if (f->type != video->queue->type)
 		return -EINVAL;
 
-	memset(meta, 0, sizeof(*meta));
-	meta->dataformat = params->metafmt->dataformat;
-	meta->buffersize = params->metafmt->buffersize;
+	*meta = *params->metafmt;
+
+	return 0;
+}
+
+static int rkisp1_params_try_fmt_meta_out(struct file *file, void *fh,
+					  struct v4l2_format *f)
+{
+	struct video_device *video = video_devdata(file);
+	struct v4l2_meta_format *meta = &f->fmt.meta;
+
+	if (f->type != video->queue->type)
+		return -EINVAL;
+
+	*meta = *rkisp1_params_get_format_info(meta->dataformat);
+
+	return 0;
+}
+
+static int rkisp1_params_s_fmt_meta_out(struct file *file, void *fh,
+					struct v4l2_format *f)
+{
+	struct video_device *video = video_devdata(file);
+	struct rkisp1_params *params = video_get_drvdata(video);
+	struct v4l2_meta_format *meta = &f->fmt.meta;
+
+	if (f->type != video->queue->type)
+		return -EINVAL;
+
+	if (vb2_is_busy(video->queue))
+		return -EBUSY;
+
+	params->metafmt = rkisp1_params_get_format_info(meta->dataformat);
+	*meta = *params->metafmt;
 
 	return 0;
 }
@@ -2288,8 +2330,8 @@ static const struct v4l2_ioctl_ops rkisp1_params_ioctl = {
 	.vidioc_streamoff = vb2_ioctl_streamoff,
 	.vidioc_enum_fmt_meta_out = rkisp1_params_enum_fmt_meta_out,
 	.vidioc_g_fmt_meta_out = rkisp1_params_g_fmt_meta_out,
-	.vidioc_s_fmt_meta_out = rkisp1_params_g_fmt_meta_out,
-	.vidioc_try_fmt_meta_out = rkisp1_params_g_fmt_meta_out,
+	.vidioc_s_fmt_meta_out = rkisp1_params_s_fmt_meta_out,
+	.vidioc_try_fmt_meta_out = rkisp1_params_try_fmt_meta_out,
 	.vidioc_querycap = rkisp1_params_querycap,
 	.vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
 	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
-- 
2.45.2

[PATCH v7 08/12] media: rkisp1: Add helper function to swap colour channels

[Jacopo Mondi]

From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

The BLS parameters passed by userspace are specified for named colour
channels (R, Gr, Gb and B), while the hardware registers reference
positions in the 2x2 CFA pattern (A, B, C and D).

The BLS values are swapped based on the CFA pattern when writing to or
reading from registers, using hand-roled switch statements. The logic is
duplicated already, and new code will require similar processing. Move
the swap logic to a shared function, using static data to control the
channels order.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
---
 .../platform/rockchip/rkisp1/rkisp1-common.c  | 14 +++++
 .../platform/rockchip/rkisp1/rkisp1-common.h  |  3 +
 .../platform/rockchip/rkisp1/rkisp1-params.c  | 62 +++++--------------
 .../platform/rockchip/rkisp1/rkisp1-stats.c   | 51 +++++----------
 4 files changed, 45 insertions(+), 85 deletions(-)

diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-common.c b/drivers/media/platform/rockchip/rkisp1/rkisp1-common.c
index f956b90a407a..60c97bb7b18b 100644
--- a/drivers/media/platform/rockchip/rkisp1/rkisp1-common.c
+++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-common.c
@@ -178,3 +178,17 @@ void rkisp1_sd_adjust_crop(struct v4l2_rect *crop,
 
 	rkisp1_sd_adjust_crop_rect(crop, &crop_bounds);
 }
+
+void rkisp1_bls_swap_regs(enum rkisp1_fmt_raw_pat_type pattern,
+			  const u32 input[4], u32 output[4])
+{
+	static const unsigned int swap[4][4] = {
+		[RKISP1_RAW_RGGB] = { 0, 1, 2, 3 },
+		[RKISP1_RAW_GRBG] = { 1, 0, 3, 2 },
+		[RKISP1_RAW_GBRG] = { 2, 3, 0, 1 },
+		[RKISP1_RAW_BGGR] = { 3, 2, 1, 0 },
+	};
+
+	for (unsigned int i = 0; i < 4; ++i)
+		output[i] = input[swap[pattern][i]];
+}
diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h b/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h
index 2f4bf7e97927..6fbc69128b55 100644
--- a/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h
+++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h
@@ -598,6 +598,9 @@ void rkisp1_sd_adjust_crop_rect(struct v4l2_rect *crop,
 void rkisp1_sd_adjust_crop(struct v4l2_rect *crop,
 			   const struct v4l2_mbus_framefmt *bounds);
 
+void rkisp1_bls_swap_regs(enum rkisp1_fmt_raw_pat_type pattern,
+			  const u32 input[4], u32 output[4]);
+
 /*
  * rkisp1_mbus_info_get_by_code - get the isp info of the media bus code
  *
diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c b/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c
index d0e3974a8098..ca24ed858448 100644
--- a/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c
+++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c
@@ -165,54 +165,20 @@ static void rkisp1_bls_config(struct rkisp1_params *params,
 	new_control &= RKISP1_CIF_ISP_BLS_ENA;
 	/* fixed subtraction values */
 	if (!arg->enable_auto) {
-		const struct rkisp1_cif_isp_bls_fixed_val *pval =
-								&arg->fixed_val;
-
-		switch (params->raw_type) {
-		case RKISP1_RAW_BGGR:
-			rkisp1_write(params->rkisp1, RKISP1_CIF_ISP_BLS_D_FIXED,
-				     pval->r);
-			rkisp1_write(params->rkisp1, RKISP1_CIF_ISP_BLS_C_FIXED,
-				     pval->gr);
-			rkisp1_write(params->rkisp1, RKISP1_CIF_ISP_BLS_B_FIXED,
-				     pval->gb);
-			rkisp1_write(params->rkisp1, RKISP1_CIF_ISP_BLS_A_FIXED,
-				     pval->b);
-			break;
-		case RKISP1_RAW_GBRG:
-			rkisp1_write(params->rkisp1, RKISP1_CIF_ISP_BLS_C_FIXED,
-				     pval->r);
-			rkisp1_write(params->rkisp1, RKISP1_CIF_ISP_BLS_D_FIXED,
-				     pval->gr);
-			rkisp1_write(params->rkisp1, RKISP1_CIF_ISP_BLS_A_FIXED,
-				     pval->gb);
-			rkisp1_write(params->rkisp1, RKISP1_CIF_ISP_BLS_B_FIXED,
-				     pval->b);
-			break;
-		case RKISP1_RAW_GRBG:
-			rkisp1_write(params->rkisp1, RKISP1_CIF_ISP_BLS_B_FIXED,
-				     pval->r);
-			rkisp1_write(params->rkisp1, RKISP1_CIF_ISP_BLS_A_FIXED,
-				     pval->gr);
-			rkisp1_write(params->rkisp1, RKISP1_CIF_ISP_BLS_D_FIXED,
-				     pval->gb);
-			rkisp1_write(params->rkisp1, RKISP1_CIF_ISP_BLS_C_FIXED,
-				     pval->b);
-			break;
-		case RKISP1_RAW_RGGB:
-			rkisp1_write(params->rkisp1, RKISP1_CIF_ISP_BLS_A_FIXED,
-				     pval->r);
-			rkisp1_write(params->rkisp1, RKISP1_CIF_ISP_BLS_B_FIXED,
-				     pval->gr);
-			rkisp1_write(params->rkisp1, RKISP1_CIF_ISP_BLS_C_FIXED,
-				     pval->gb);
-			rkisp1_write(params->rkisp1, RKISP1_CIF_ISP_BLS_D_FIXED,
-				     pval->b);
-			break;
-		default:
-			break;
-		}
-
+		static const u32 regs[] = {
+			RKISP1_CIF_ISP_BLS_A_FIXED,
+			RKISP1_CIF_ISP_BLS_B_FIXED,
+			RKISP1_CIF_ISP_BLS_C_FIXED,
+			RKISP1_CIF_ISP_BLS_D_FIXED,
+		};
+		u32 swapped[4];
+
+		rkisp1_bls_swap_regs(params->raw_type, regs, swapped);
+
+		rkisp1_write(params->rkisp1, swapped[0], arg->fixed_val.r);
+		rkisp1_write(params->rkisp1, swapped[1], arg->fixed_val.gr);
+		rkisp1_write(params->rkisp1, swapped[2], arg->fixed_val.gb);
+		rkisp1_write(params->rkisp1, swapped[3], arg->fixed_val.b);
 	} else {
 		if (arg->en_windows & BIT(1)) {
 			rkisp1_write(params->rkisp1, RKISP1_CIF_ISP_BLS_H2_START,
diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-stats.c b/drivers/media/platform/rockchip/rkisp1/rkisp1-stats.c
index 2795eef91bdd..a502719e916a 100644
--- a/drivers/media/platform/rockchip/rkisp1/rkisp1-stats.c
+++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-stats.c
@@ -304,48 +304,25 @@ static void rkisp1_stats_get_hst_meas_v12(struct rkisp1_stats *stats,
 static void rkisp1_stats_get_bls_meas(struct rkisp1_stats *stats,
 				      struct rkisp1_stat_buffer *pbuf)
 {
+	static const u32 regs[] = {
+		RKISP1_CIF_ISP_BLS_A_MEASURED,
+		RKISP1_CIF_ISP_BLS_B_MEASURED,
+		RKISP1_CIF_ISP_BLS_C_MEASURED,
+		RKISP1_CIF_ISP_BLS_D_MEASURED,
+	};
 	struct rkisp1_device *rkisp1 = stats->rkisp1;
 	const struct rkisp1_mbus_info *in_fmt = rkisp1->isp.sink_fmt;
 	struct rkisp1_cif_isp_bls_meas_val *bls_val;
+	u32 swapped[4];
+
+	rkisp1_bls_swap_regs(in_fmt->bayer_pat, regs, swapped);
 
 	bls_val = &pbuf->params.ae.bls_val;
-	if (in_fmt->bayer_pat == RKISP1_RAW_BGGR) {
-		bls_val->meas_b =
-			rkisp1_read(rkisp1, RKISP1_CIF_ISP_BLS_A_MEASURED);
-		bls_val->meas_gb =
-			rkisp1_read(rkisp1, RKISP1_CIF_ISP_BLS_B_MEASURED);
-		bls_val->meas_gr =
-			rkisp1_read(rkisp1, RKISP1_CIF_ISP_BLS_C_MEASURED);
-		bls_val->meas_r =
-			rkisp1_read(rkisp1, RKISP1_CIF_ISP_BLS_D_MEASURED);
-	} else if (in_fmt->bayer_pat == RKISP1_RAW_GBRG) {
-		bls_val->meas_gb =
-			rkisp1_read(rkisp1, RKISP1_CIF_ISP_BLS_A_MEASURED);
-		bls_val->meas_b =
-			rkisp1_read(rkisp1, RKISP1_CIF_ISP_BLS_B_MEASURED);
-		bls_val->meas_r =
-			rkisp1_read(rkisp1, RKISP1_CIF_ISP_BLS_C_MEASURED);
-		bls_val->meas_gr =
-			rkisp1_read(rkisp1, RKISP1_CIF_ISP_BLS_D_MEASURED);
-	} else if (in_fmt->bayer_pat == RKISP1_RAW_GRBG) {
-		bls_val->meas_gr =
-			rkisp1_read(rkisp1, RKISP1_CIF_ISP_BLS_A_MEASURED);
-		bls_val->meas_r =
-			rkisp1_read(rkisp1, RKISP1_CIF_ISP_BLS_B_MEASURED);
-		bls_val->meas_b =
-			rkisp1_read(rkisp1, RKISP1_CIF_ISP_BLS_C_MEASURED);
-		bls_val->meas_gb =
-			rkisp1_read(rkisp1, RKISP1_CIF_ISP_BLS_D_MEASURED);
-	} else if (in_fmt->bayer_pat == RKISP1_RAW_RGGB) {
-		bls_val->meas_r =
-			rkisp1_read(rkisp1, RKISP1_CIF_ISP_BLS_A_MEASURED);
-		bls_val->meas_gr =
-			rkisp1_read(rkisp1, RKISP1_CIF_ISP_BLS_B_MEASURED);
-		bls_val->meas_gb =
-			rkisp1_read(rkisp1, RKISP1_CIF_ISP_BLS_C_MEASURED);
-		bls_val->meas_b =
-			rkisp1_read(rkisp1, RKISP1_CIF_ISP_BLS_D_MEASURED);
-	}
+
+	bls_val->meas_r = rkisp1_read(rkisp1, swapped[0]);
+	bls_val->meas_gr = rkisp1_read(rkisp1, swapped[1]);
+	bls_val->meas_gb = rkisp1_read(rkisp1, swapped[2]);
+	bls_val->meas_b = rkisp1_read(rkisp1, swapped[3]);
 }
 
 static const struct rkisp1_stats_ops rkisp1_v10_stats_ops = {
-- 
2.45.2

[PATCH v7 09/12] media: rkisp1: Add features mask to extensible block handlers

[Jacopo Mondi]

From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

Future ISP parameter blocks for i.MX8MP-specific features will not
support on Rockchip platforms as they lack the corresponding hardware.
Introduce a features mask in the extensible block handlers to indicate
which device features a block require, and ignore blocks that require
unavailable features.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
---
 drivers/media/platform/rockchip/rkisp1/rkisp1-params.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c b/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c
index ca24ed858448..016d8d50a17b 100644
--- a/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c
+++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c
@@ -1848,6 +1848,7 @@ static const struct rkisp1_ext_params_handler {
 	size_t size;
 	rkisp1_block_handler handler;
 	unsigned int group;
+	unsigned int features;
 } rkisp1_ext_params_handlers[] = {
 	[RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS] = {
 		.size		= sizeof(struct rkisp1_ext_params_bls_config),
@@ -1954,11 +1955,18 @@ static void rkisp1_ext_params_config(struct rkisp1_params *params,
 			&cfg->data[block_offset];
 		block_offset += block->header.size;
 
-		/* Make sure the block is in the list of groups to configure. */
+		/*
+		 * Make sure the block is supported by the platform and in the
+		 * list of groups to configure.
+		 */
 		block_handler = &rkisp1_ext_params_handlers[block->header.type];
 		if (!(block_handler->group & block_group_mask))
 			continue;
 
+		if ((params->rkisp1->info->features & block_handler->features) !=
+		    block_handler->features)
+			continue;
+
 		block_handler->handler(params, block);
 
 		if (block->header.enable == RKISP1_EXT_PARAMS_BLOCK_DISABLE)
-- 
2.45.2

[PATCH v7 10/12] media: rkisp1: Add register definitions for the companding block

[Jacopo Mondi]

From: Paul Elder <paul.elder@ideasonboard.com>

To prepare for adding support for the companding block to the rkisp1
driver for the version of the ISP on the i.MX8MP, add the register
definitions for it, including relevant register field values.

Signed-off-by: Paul Elder <paul.elder@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
---
 .../platform/rockchip/rkisp1/rkisp1-regs.h    | 23 +++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-regs.h b/drivers/media/platform/rockchip/rkisp1/rkisp1-regs.h
index fccf4c17ee8d..bf0260600a19 100644
--- a/drivers/media/platform/rockchip/rkisp1/rkisp1-regs.h
+++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-regs.h
@@ -704,6 +704,12 @@
 #define RKISP1_CIF_ISP_DPF_SPATIAL_COEFF_MAX		0x1f
 #define RKISP1_CIF_ISP_DPF_NLL_COEFF_N_MAX		0x3ff
 
+/* COMPAND */
+#define RKISP1_CIF_ISP_COMPAND_CTRL_EXPAND_ENABLE	BIT(0)
+#define RKISP1_CIF_ISP_COMPAND_CTRL_COMPRESS_ENABLE	BIT(1)
+#define RKISP1_CIF_ISP_COMPAND_CTRL_SOFT_RESET_FLAG	BIT(2)
+#define RKISP1_CIF_ISP_COMPAND_CTRL_BLS_ENABLE		BIT(3)
+
 /* =================================================================== */
 /*                            CIF Registers                            */
 /* =================================================================== */
@@ -1394,6 +1400,23 @@
 #define RKISP1_CIF_ISP_VSM_DELTA_H		(RKISP1_CIF_ISP_VSM_BASE + 0x0000001c)
 #define RKISP1_CIF_ISP_VSM_DELTA_V		(RKISP1_CIF_ISP_VSM_BASE + 0x00000020)
 
+#define RKISP1_CIF_ISP_COMPAND_BASE			0x00003200
+#define RKISP1_CIF_ISP_COMPAND_CTRL			(RKISP1_CIF_ISP_COMPAND_BASE + 0x00000000)
+#define RKISP1_CIF_ISP_COMPAND_BLS_A_FIXED		(RKISP1_CIF_ISP_COMPAND_BASE + 0x00000004)
+#define RKISP1_CIF_ISP_COMPAND_BLS_B_FIXED		(RKISP1_CIF_ISP_COMPAND_BASE + 0x00000008)
+#define RKISP1_CIF_ISP_COMPAND_BLS_C_FIXED		(RKISP1_CIF_ISP_COMPAND_BASE + 0x0000000c)
+#define RKISP1_CIF_ISP_COMPAND_BLS_D_FIXED		(RKISP1_CIF_ISP_COMPAND_BASE + 0x00000010)
+#define RKISP1_CIF_ISP_COMPAND_EXPAND_PX_N(n)		(RKISP1_CIF_ISP_COMPAND_BASE + 0x00000014 + (n) * 4)
+#define RKISP1_CIF_ISP_COMPAND_COMPRESS_PX_N(n)		(RKISP1_CIF_ISP_COMPAND_BASE + 0x00000040 + (n) * 4)
+#define RKISP1_CIF_ISP_COMPAND_EXPAND_Y_ADDR		(RKISP1_CIF_ISP_COMPAND_BASE + 0x0000006c)
+#define RKISP1_CIF_ISP_COMPAND_EXPAND_Y_WRITE_DATA	(RKISP1_CIF_ISP_COMPAND_BASE + 0x00000070)
+#define RKISP1_CIF_ISP_COMPAND_COMPRESS_Y_ADDR		(RKISP1_CIF_ISP_COMPAND_BASE + 0x00000074)
+#define RKISP1_CIF_ISP_COMPAND_COMPRESS_Y_WRITE_DATA	(RKISP1_CIF_ISP_COMPAND_BASE + 0x00000078)
+#define RKISP1_CIF_ISP_COMPAND_EXPAND_X_ADDR		(RKISP1_CIF_ISP_COMPAND_BASE + 0x0000007c)
+#define RKISP1_CIF_ISP_COMPAND_EXPAND_X_WRITE_DATA	(RKISP1_CIF_ISP_COMPAND_BASE + 0x00000080)
+#define RKISP1_CIF_ISP_COMPAND_COMPRESS_X_ADDR		(RKISP1_CIF_ISP_COMPAND_BASE + 0x00000084)
+#define RKISP1_CIF_ISP_COMPAND_COMPRESS_X_WRITE_DATA	(RKISP1_CIF_ISP_COMPAND_BASE + 0x00000088)
+
 #define RKISP1_CIF_ISP_CSI0_BASE		0x00007000
 #define RKISP1_CIF_ISP_CSI0_CTRL0		(RKISP1_CIF_ISP_CSI0_BASE + 0x00000000)
 
-- 
2.45.2

[PATCH v7 11/12] media: rkisp1: Add feature flags for BLS and compand

[Jacopo Mondi]

From: Paul Elder <paul.elder@ideasonboard.com>

Add feature flags for the dedicated black level subtraction hardware
block and for the compand hardware block. The companding feature flag is
added on its own (as opposed to "the absence of BLS") because we will
need it later for when we add support for the companding block.

Skip BLS configuration when the BLS feature flag is unset, as devices
without the dedicated BLS block cannot configure a hardware block that
doesn't exist.

Signed-off-by: Paul Elder <paul.elder@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
---
 drivers/media/platform/rockchip/rkisp1/rkisp1-common.h | 4 ++++
 drivers/media/platform/rockchip/rkisp1/rkisp1-dev.c    | 9 ++++++---
 drivers/media/platform/rockchip/rkisp1/rkisp1-params.c | 7 +++++++
 3 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h b/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h
index 6fbc69128b55..964d1d200d0b 100644
--- a/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h
+++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h
@@ -115,6 +115,8 @@ enum rkisp1_isp_pad {
  * @RKISP1_FEATURE_SELF_PATH: The ISP has a self path
  * @RKISP1_FEATURE_DUAL_CROP: The ISP has the dual crop block at the resizer input
  * @RKISP1_FEATURE_DMA_34BIT: The ISP uses 34-bit DMA addresses
+ * @RKISP1_FEATURE_BLS: The ISP has a dedicated BLS block
+ * @RKISP1_FEATURE_COMPAND: The ISP has a companding block
  *
  * The ISP features are stored in a bitmask in &rkisp1_info.features and allow
  * the driver to implement support for features present in some ISP versions
@@ -126,6 +128,8 @@ enum rkisp1_feature {
 	RKISP1_FEATURE_SELF_PATH = BIT(2),
 	RKISP1_FEATURE_DUAL_CROP = BIT(3),
 	RKISP1_FEATURE_DMA_34BIT = BIT(4),
+	RKISP1_FEATURE_BLS = BIT(5),
+	RKISP1_FEATURE_COMPAND = BIT(6),
 };
 
 #define rkisp1_has_feature(rkisp1, feature) \
diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-dev.c b/drivers/media/platform/rockchip/rkisp1/rkisp1-dev.c
index bb0202386c70..823814d8e687 100644
--- a/drivers/media/platform/rockchip/rkisp1/rkisp1-dev.c
+++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-dev.c
@@ -509,7 +509,8 @@ static const struct rkisp1_info px30_isp_info = {
 	.isp_ver = RKISP1_V12,
 	.features = RKISP1_FEATURE_MIPI_CSI2
 		  | RKISP1_FEATURE_SELF_PATH
-		  | RKISP1_FEATURE_DUAL_CROP,
+		  | RKISP1_FEATURE_DUAL_CROP
+		  | RKISP1_FEATURE_BLS,
 };
 
 static const char * const rk3399_isp_clks[] = {
@@ -530,7 +531,8 @@ static const struct rkisp1_info rk3399_isp_info = {
 	.isp_ver = RKISP1_V10,
 	.features = RKISP1_FEATURE_MIPI_CSI2
 		  | RKISP1_FEATURE_SELF_PATH
-		  | RKISP1_FEATURE_DUAL_CROP,
+		  | RKISP1_FEATURE_DUAL_CROP
+		  | RKISP1_FEATURE_BLS,
 };
 
 static const char * const imx8mp_isp_clks[] = {
@@ -550,7 +552,8 @@ static const struct rkisp1_info imx8mp_isp_info = {
 	.isr_size = ARRAY_SIZE(imx8mp_isp_isrs),
 	.isp_ver = RKISP1_V_IMX8MP,
 	.features = RKISP1_FEATURE_MAIN_STRIDE
-		  | RKISP1_FEATURE_DMA_34BIT,
+		  | RKISP1_FEATURE_DMA_34BIT
+		  | RKISP1_FEATURE_COMPAND,
 };
 
 static const struct of_device_id rkisp1_of_match[] = {
diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c b/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c
index 016d8d50a17b..c43b684387ec 100644
--- a/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c
+++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c
@@ -1268,6 +1268,12 @@ rkisp1_isp_isr_other_config(struct rkisp1_params *params,
 	module_cfg_update = new_params->module_cfg_update;
 	module_ens = new_params->module_ens;
 
+	if (!rkisp1_has_feature(params->rkisp1, BLS)) {
+		module_en_update &= ~RKISP1_CIF_ISP_MODULE_BLS;
+		module_cfg_update &= ~RKISP1_CIF_ISP_MODULE_BLS;
+		module_ens &= ~RKISP1_CIF_ISP_MODULE_BLS;
+	}
+
 	/* update dpc config */
 	if (module_cfg_update & RKISP1_CIF_ISP_MODULE_DPCC)
 		rkisp1_dpcc_config(params,
@@ -1854,6 +1860,7 @@ static const struct rkisp1_ext_params_handler {
 		.size		= sizeof(struct rkisp1_ext_params_bls_config),
 		.handler	= rkisp1_ext_params_bls,
 		.group		= RKISP1_EXT_PARAMS_BLOCK_GROUP_OTHERS,
+		.features       = RKISP1_FEATURE_BLS,
 	},
 	[RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC] = {
 		.size		= sizeof(struct rkisp1_ext_params_dpcc_config),
-- 
2.45.2

[PATCH v7 12/12] media: rkisp1: Add support for the companding block

[Jacopo Mondi]

From: Paul Elder <paul.elder@ideasonboard.com>

Add support to the rkisp1 driver for the companding block that exists on
the i.MX8MP version of the ISP. This requires usage of the new
extensible parameters format, and showcases how the format allows for
extensions without breaking backward compatibility.

Signed-off-by: Paul Elder <paul.elder@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
---
 .../platform/rockchip/rkisp1/rkisp1-params.c  | 168 ++++++++++++++++++
 include/uapi/linux/rkisp1-config.h            |  89 +++++++++-
 2 files changed, 256 insertions(+), 1 deletion(-)

diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c b/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c
index c43b684387ec..7dc94b5ca63f 100644
--- a/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c
+++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c
@@ -5,6 +5,7 @@
  * Copyright (C) 2017 Rockchip Electronics Co., Ltd.
  */
 
+#include <linux/math.h>
 #include <linux/string.h>
 
 #include <media/v4l2-common.h>
@@ -57,6 +58,8 @@ union rkisp1_ext_params_config {
 	struct rkisp1_ext_params_hst_config hst;
 	struct rkisp1_ext_params_aec_config aec;
 	struct rkisp1_ext_params_afc_config afc;
+	struct rkisp1_ext_params_compand_bls_config compand_bls;
+	struct rkisp1_ext_params_compand_curve_config compand_curve;
 };
 
 enum rkisp1_params_formats {
@@ -1258,6 +1261,93 @@ rkisp1_dpf_strength_config(struct rkisp1_params *params,
 	rkisp1_write(params->rkisp1, RKISP1_CIF_ISP_DPF_STRENGTH_R, arg->r);
 }
 
+static void rkisp1_compand_write_px_curve(struct rkisp1_params *params,
+					  unsigned int addr, const u8 *curve)
+{
+	const unsigned int points_per_reg = 6;
+	const unsigned int num_regs =
+		DIV_ROUND_UP(RKISP1_CIF_ISP_COMPAND_NUM_POINTS,
+			     points_per_reg);
+
+	/*
+	 * The compand curve is specified as a piecewise linear function with
+	 * 64 points. X coordinates are stored as a log2 of the displacement
+	 * from the previous point, in 5 bits, with 6 values per register. The
+	 * last register stores 4 values.
+	 */
+	for (unsigned int reg = 0; reg < num_regs; ++reg) {
+		unsigned int num_points =
+			min(RKISP1_CIF_ISP_COMPAND_NUM_POINTS -
+			    reg * points_per_reg, points_per_reg);
+		u32 val = 0;
+
+		for (unsigned int i = 0; i < num_points; i++)
+			val |= (*curve++ & 0x1f) << (i * 5);
+
+		rkisp1_write(params->rkisp1, addr, val);
+		addr += 4;
+	}
+}
+
+static void
+rkisp1_compand_write_curve_mem(struct rkisp1_params *params,
+			       unsigned int reg_addr, unsigned int reg_data,
+			       const u32 curve[RKISP1_CIF_ISP_COMPAND_NUM_POINTS])
+{
+	for (unsigned int i = 0; i < RKISP1_CIF_ISP_COMPAND_NUM_POINTS; i++) {
+		rkisp1_write(params->rkisp1, reg_addr, i);
+		rkisp1_write(params->rkisp1, reg_data, curve[i]);
+	}
+}
+
+static void
+rkisp1_compand_bls_config(struct rkisp1_params *params,
+			  const struct rkisp1_cif_isp_compand_bls_config *arg)
+{
+	static const u32 regs[] = {
+		RKISP1_CIF_ISP_COMPAND_BLS_A_FIXED,
+		RKISP1_CIF_ISP_COMPAND_BLS_B_FIXED,
+		RKISP1_CIF_ISP_COMPAND_BLS_C_FIXED,
+		RKISP1_CIF_ISP_COMPAND_BLS_D_FIXED,
+	};
+	u32 swapped[4];
+
+	rkisp1_bls_swap_regs(params->raw_type, regs, swapped);
+
+	rkisp1_write(params->rkisp1, swapped[0], arg->r);
+	rkisp1_write(params->rkisp1, swapped[1], arg->gr);
+	rkisp1_write(params->rkisp1, swapped[2], arg->gb);
+	rkisp1_write(params->rkisp1, swapped[3], arg->b);
+}
+
+static void
+rkisp1_compand_expand_config(struct rkisp1_params *params,
+			     const struct rkisp1_cif_isp_compand_curve_config *arg)
+{
+	rkisp1_compand_write_px_curve(params, RKISP1_CIF_ISP_COMPAND_EXPAND_PX_N(0),
+				      arg->px);
+	rkisp1_compand_write_curve_mem(params, RKISP1_CIF_ISP_COMPAND_EXPAND_Y_ADDR,
+				       RKISP1_CIF_ISP_COMPAND_EXPAND_Y_WRITE_DATA,
+				       arg->y);
+	rkisp1_compand_write_curve_mem(params, RKISP1_CIF_ISP_COMPAND_EXPAND_X_ADDR,
+				       RKISP1_CIF_ISP_COMPAND_EXPAND_X_WRITE_DATA,
+				       arg->x);
+}
+
+static void
+rkisp1_compand_compress_config(struct rkisp1_params *params,
+			       const struct rkisp1_cif_isp_compand_curve_config *arg)
+{
+	rkisp1_compand_write_px_curve(params, RKISP1_CIF_ISP_COMPAND_COMPRESS_PX_N(0),
+				      arg->px);
+	rkisp1_compand_write_curve_mem(params, RKISP1_CIF_ISP_COMPAND_COMPRESS_Y_ADDR,
+				       RKISP1_CIF_ISP_COMPAND_COMPRESS_Y_WRITE_DATA,
+				       arg->y);
+	rkisp1_compand_write_curve_mem(params, RKISP1_CIF_ISP_COMPAND_COMPRESS_X_ADDR,
+				       RKISP1_CIF_ISP_COMPAND_COMPRESS_X_WRITE_DATA,
+				       arg->x);
+}
+
 static void
 rkisp1_isp_isr_other_config(struct rkisp1_params *params,
 			    const struct rkisp1_params_cfg *new_params)
@@ -1847,6 +1937,66 @@ rkisp1_ext_params_afcm(struct rkisp1_params *params,
 				      RKISP1_CIF_ISP_AFM_ENA);
 }
 
+static void rkisp1_ext_params_compand_bls(struct rkisp1_params *params,
+					  const union rkisp1_ext_params_config *block)
+{
+	const struct rkisp1_ext_params_compand_bls_config *bls =
+		&block->compand_bls;
+
+	if (bls->header.enable == RKISP1_EXT_PARAMS_BLOCK_DISABLE) {
+		rkisp1_param_clear_bits(params, RKISP1_CIF_ISP_COMPAND_CTRL,
+					RKISP1_CIF_ISP_COMPAND_CTRL_BLS_ENABLE);
+		return;
+	}
+
+	rkisp1_compand_bls_config(params, &bls->config);
+
+	if (!(params->enabled_blocks &
+	      BIT(RKISP1_EXT_PARAMS_BLOCK_TYPE_COMPAND_BLS)))
+		rkisp1_param_set_bits(params, RKISP1_CIF_ISP_COMPAND_CTRL,
+				      RKISP1_CIF_ISP_COMPAND_CTRL_BLS_ENABLE);
+}
+
+static void rkisp1_ext_params_compand_expand(struct rkisp1_params *params,
+					     const union rkisp1_ext_params_config *block)
+{
+	const struct rkisp1_ext_params_compand_curve_config *curve =
+		&block->compand_curve;
+
+	if (curve->header.enable == RKISP1_EXT_PARAMS_BLOCK_DISABLE) {
+		rkisp1_param_clear_bits(params, RKISP1_CIF_ISP_COMPAND_CTRL,
+					RKISP1_CIF_ISP_COMPAND_CTRL_EXPAND_ENABLE);
+		return;
+	}
+
+	rkisp1_compand_expand_config(params, &curve->config);
+
+	if (!(params->enabled_blocks &
+	      BIT(RKISP1_EXT_PARAMS_BLOCK_TYPE_COMPAND_EXPAND)))
+		rkisp1_param_set_bits(params, RKISP1_CIF_ISP_COMPAND_CTRL,
+				      RKISP1_CIF_ISP_COMPAND_CTRL_EXPAND_ENABLE);
+}
+
+static void rkisp1_ext_params_compand_compress(struct rkisp1_params *params,
+					       const union rkisp1_ext_params_config *block)
+{
+	const struct rkisp1_ext_params_compand_curve_config *curve =
+		&block->compand_curve;
+
+	if (curve->header.enable == RKISP1_EXT_PARAMS_BLOCK_DISABLE) {
+		rkisp1_param_clear_bits(params, RKISP1_CIF_ISP_COMPAND_CTRL,
+					RKISP1_CIF_ISP_COMPAND_CTRL_COMPRESS_ENABLE);
+		return;
+	}
+
+	rkisp1_compand_compress_config(params, &curve->config);
+
+	if (!(params->enabled_blocks &
+	      BIT(RKISP1_EXT_PARAMS_BLOCK_TYPE_COMPAND_COMPRESS)))
+		rkisp1_param_set_bits(params, RKISP1_CIF_ISP_COMPAND_CTRL,
+				      RKISP1_CIF_ISP_COMPAND_CTRL_COMPRESS_ENABLE);
+}
+
 typedef void (*rkisp1_block_handler)(struct rkisp1_params *params,
 			     const union rkisp1_ext_params_config *config);
 
@@ -1942,6 +2092,24 @@ static const struct rkisp1_ext_params_handler {
 		.handler	= rkisp1_ext_params_afcm,
 		.group		= RKISP1_EXT_PARAMS_BLOCK_GROUP_OTHERS,
 	},
+	[RKISP1_EXT_PARAMS_BLOCK_TYPE_COMPAND_BLS] = {
+		.size		= sizeof(struct rkisp1_ext_params_compand_bls_config),
+		.handler	= rkisp1_ext_params_compand_bls,
+		.group		= RKISP1_EXT_PARAMS_BLOCK_GROUP_OTHERS,
+		.features	= RKISP1_FEATURE_COMPAND,
+	},
+	[RKISP1_EXT_PARAMS_BLOCK_TYPE_COMPAND_EXPAND] = {
+		.size		= sizeof(struct rkisp1_ext_params_compand_curve_config),
+		.handler	= rkisp1_ext_params_compand_expand,
+		.group		= RKISP1_EXT_PARAMS_BLOCK_GROUP_OTHERS,
+		.features	= RKISP1_FEATURE_COMPAND,
+	},
+	[RKISP1_EXT_PARAMS_BLOCK_TYPE_COMPAND_COMPRESS] = {
+		.size		= sizeof(struct rkisp1_ext_params_compand_curve_config),
+		.handler	= rkisp1_ext_params_compand_compress,
+		.group		= RKISP1_EXT_PARAMS_BLOCK_GROUP_OTHERS,
+		.features	= RKISP1_FEATURE_COMPAND,
+	},
 };
 
 static void rkisp1_ext_params_config(struct rkisp1_params *params,
diff --git a/include/uapi/linux/rkisp1-config.h b/include/uapi/linux/rkisp1-config.h
index 00b09c92cca7..bee459a5974b 100644
--- a/include/uapi/linux/rkisp1-config.h
+++ b/include/uapi/linux/rkisp1-config.h
@@ -164,6 +164,11 @@
 #define RKISP1_CIF_ISP_DPF_MAX_NLF_COEFFS      17
 #define RKISP1_CIF_ISP_DPF_MAX_SPATIAL_COEFFS  6
 
+/*
+ * Compand
+ */
+#define RKISP1_CIF_ISP_COMPAND_NUM_POINTS	64
+
 /*
  * Measurement types
  */
@@ -851,6 +856,39 @@ struct rkisp1_params_cfg {
 	struct rkisp1_cif_isp_isp_other_cfg others;
 };
 
+/**
+ * struct rkisp1_cif_isp_compand_bls_config - Rockchip ISP1 Companding parameters (BLS)
+ * @r: Fixed subtraction value for Bayer pattern R
+ * @gr: Fixed subtraction value for Bayer pattern Gr
+ * @gb: Fixed subtraction value for Bayer pattern Gb
+ * @b: Fixed subtraction value for Bayer pattern B
+ *
+ * The values will be subtracted from the sensor values. Note that unlike the
+ * dedicated BLS block, the BLS values in the compander are 20-bit unsigned.
+ */
+struct rkisp1_cif_isp_compand_bls_config {
+	__u32 r;
+	__u32 gr;
+	__u32 gb;
+	__u32 b;
+};
+
+/**
+ * struct rkisp1_cif_isp_compand_curve_config - Rockchip ISP1 Companding
+ * parameters (expand and compression curves)
+ * @px: Compand curve x-values. Each value stores the distance from the
+ *      previous x-value, expressed as log2 of the distance on 5 bits.
+ * @x: Compand curve x-values. The functionality of these parameters are
+ *     unknown due to do a lack of hardware documentation, but these are left
+ *     here for future compatibility purposes.
+ * @y: Compand curve y-values
+ */
+struct rkisp1_cif_isp_compand_curve_config {
+	__u8 px[RKISP1_CIF_ISP_COMPAND_NUM_POINTS];
+	__u32 x[RKISP1_CIF_ISP_COMPAND_NUM_POINTS];
+	__u32 y[RKISP1_CIF_ISP_COMPAND_NUM_POINTS];
+};
+
 /*---------- PART2: Measurement Statistics ------------*/
 
 /**
@@ -1018,6 +1056,9 @@ struct rkisp1_stat_buffer {
  * @RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS: Histogram statistics
  * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS: Auto exposure statistics
  * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS: Auto-focus statistics
+ * @RKISP1_EXT_PARAMS_BLOCK_TYPE_COMPAND_BLS: BLS in the compand block
+ * @RKISP1_EXT_PARAMS_BLOCK_TYPE_COMPAND_EXPAND: Companding expand curve
+ * @RKISP1_EXT_PARAMS_BLOCK_TYPE_COMPAND_COMPRESS: Companding compress curve
  */
 enum rkisp1_ext_params_block_type {
 	RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS,
@@ -1037,6 +1078,9 @@ enum rkisp1_ext_params_block_type {
 	RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS,
 	RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS,
 	RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS,
+	RKISP1_EXT_PARAMS_BLOCK_TYPE_COMPAND_BLS,
+	RKISP1_EXT_PARAMS_BLOCK_TYPE_COMPAND_EXPAND,
+	RKISP1_EXT_PARAMS_BLOCK_TYPE_COMPAND_COMPRESS,
 };
 
 /**
@@ -1384,6 +1428,46 @@ struct rkisp1_ext_params_afc_config {
 	struct rkisp1_cif_isp_afc_config config;
 } __attribute__((aligned(8)));
 
+/**
+ * struct rkisp1_ext_params_compand_bls_config - RkISP1 extensible params
+ * Compand BLS config
+ *
+ * RkISP1 extensible parameters Companding configuration block (black level
+ * subtraction). Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_COMPAND_BLS`.
+ *
+ * @header: The RkISP1 extensible parameters header, see
+ *	    :c:type:`rkisp1_ext_params_block_header`
+ * @config: Companding BLS configuration, see
+ *	    :c:type:`rkisp1_cif_isp_compand_bls_config`
+ */
+struct rkisp1_ext_params_compand_bls_config {
+	struct rkisp1_ext_params_block_header header;
+	struct rkisp1_cif_isp_compand_bls_config config;
+} __attribute__((aligned(8)));
+
+/**
+ * struct rkisp1_ext_params_compand_curve_config - RkISP1 extensible params
+ * Compand curve config
+ *
+ * RkISP1 extensible parameters Companding configuration block (expand and
+ * compression curves). Identified by
+ * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_COMPAND_EXPAND` or
+ * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_COMPAND_COMPRESS`.
+ *
+ * @header: The RkISP1 extensible parameters header, see
+ *	    :c:type:`rkisp1_ext_params_block_header`
+ * @config: Companding curve configuration, see
+ *	    :c:type:`rkisp1_cif_isp_compand_curve_config`
+ */
+struct rkisp1_ext_params_compand_curve_config {
+	struct rkisp1_ext_params_block_header header;
+	struct rkisp1_cif_isp_compand_curve_config config;
+} __attribute__((aligned(8)));
+
+/*
+ * The rkisp1_ext_params_compand_curve_config structure is counted twice as it
+ * is used for both the COMPAND_EXPAND and COMPAND_COMPRESS block types.
+ */
 #define RKISP1_EXT_PARAMS_MAX_SIZE					\
 	(sizeof(struct rkisp1_ext_params_bls_config)			+\
 	sizeof(struct rkisp1_ext_params_dpcc_config)			+\
@@ -1401,7 +1485,10 @@ struct rkisp1_ext_params_afc_config {
 	sizeof(struct rkisp1_ext_params_awb_meas_config)		+\
 	sizeof(struct rkisp1_ext_params_hst_config)			+\
 	sizeof(struct rkisp1_ext_params_aec_config)			+\
-	sizeof(struct rkisp1_ext_params_afc_config))
+	sizeof(struct rkisp1_ext_params_afc_config)			+\
+	sizeof(struct rkisp1_ext_params_compand_bls_config)		+\
+	sizeof(struct rkisp1_ext_params_compand_curve_config)		+\
+	sizeof(struct rkisp1_ext_params_compand_curve_config))
 
 /**
  * enum rksip1_ext_param_buffer_version - RkISP1 extensible parameters version
-- 
2.45.2

Re: [PATCH v7 0/12] media: rkisp1: Extensible parameters and companding

[Kieran Bingham]

Hi Jacopo,

For this series,

Tested-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

on a Debix-SOM with both an IMX335 and IMX283. And also in particular, I
can confirm the Gamma control is now functional in v7 \o/ Thanks.

--
Kieran


Quoting Jacopo Mondi (2024-07-24 09:49:51)
> v6->v7:
> - Collect [PATCH v2 0/5] media: rkisp1: Add support for the companding block
> - Fix GOC handling
> - Fix newly introduced errors in checkstyle and documentation reported by
>   https://gitlab.freedesktop.org/linux-media/users/jmondi/-/pipelines/1231492
> 
> v5->v6:
> - Collect [v5.2 6/7] from Laurent
> - Collect Paul's tags
> - Add extra validation for unexpected data after the payload end as
>   suggested by Sakari
> 
> v4->v5:
> - Refine validation of the ext params buffer following Laurent's suggestion
> - perform memcpy of the parameters buffer after sizes validation
> 
> v3->v4:
> - Introduce 'union rkisp1_ext_params_config' to avoid casts in the block
>   handlers
> 
> v2->v3:
> - Address Laurent's comments on the uAPI:
>   - rename $block_config with  just 'config'
>   - reduce header size
>   - rename a few fields/blocks
> 
> - Address Laurent's comment on the params node:
>   - Use the plane payload for memcpy() and buffer validation
>   - drop buf_out_validate() and use buf_prepare() only
>   - validate the total buffer size against the buffer payload
>   - use const pointers where possible
> 
> v1->v2:
> - re-order patches to introduce parameters buffer caching for the existing
>   "fixed" format before introducing the "extensible" format
> - align all structures to 64-bit boundaries in the uAPI
> - remove NO_CHANGE enablement state and cache a bitmask of enabled blocks
> - address review comments in documentation
> 
> The VeriSilicon ISP8000 IP, supported through the rkisp1 driver in the Linux
> kernel, is integrated in several SoCs from different vendors. Different
> revisions of the IP differ in the number of supported features and in the
> register space location assigned to specific ISP blocks.
> 
> The current configuration parameters format, defined in
> include/uapi/linux/rkisp1-config.h is realized by a C structure (struct
> rkisp1_params_cfg) which wraps other structures that allows to configure
> specific ISP blocks. The layout of the parameters buffer is part of the Linux
> kernel uAPI and can hardly be extended or modified to adapt it to different
> revisions of the same IP.
> 
> This series proposes the introduction of a new parameters format for the RkISP1
> (without dropping support for the existing one) which is designed with the goals
> of being:
> 
> 1) versioned: can be changed without breaking existing applications
> 2) extensible: new blocks and parameters can be added without breaking the uABI
> 
> To do so, a new 'struct rkisp1_ext_params_cfg' type is introduced. It wraps an
> header and a data buffer, which userspace fills with configuration blocks
> for each ISP block it intends to configure. The parameters buffer is thus of
> different effective sizes, depending on the number of blocks userspace intends
> to configure.
> 
> The kernel driver parses the data block and decides, based on the versioning
> number and the platform it operates on, how to handle each block.
> 
> The parameters format is very similar to the parameters format implemented
> in the in-review Mali C55 ISP driver [1]
> 
> CI pipeline [2]
> 
> [1] https://lore.kernel.org/linux-media/20240529152858.183799-15-dan.scally@ideasonboard.com/
> [2] https://gitlab.freedesktop.org/linux-media/users/jmondi/-/pipelines/1231500
> 
> Jacopo Mondi (7):
>   media: uapi: rkisp1-config: Add extensible params format
>   media: uapi: videodev2: Add V4L2_META_FMT_RK_ISP1_EXT_PARAMS
>   media: rkisp1: Add struct rkisp1_params_buffer
>   media: rkisp1: Copy the parameters buffer
>   media: rkisp1: Cache the currently active format
>   media: rkisp1: Implement extensible params support
>   media: rkisp1: Implement s_fmt/try_fmt
> 
> Laurent Pinchart (2):
>   media: rkisp1: Add helper function to swap colour channels
>   media: rkisp1: Add features mask to extensible block handlers
> 
> Paul Elder (3):
>   media: rkisp1: Add register definitions for the companding block
>   media: rkisp1: Add feature flags for BLS and compand
>   media: rkisp1: Add support for the companding block
> 
>  Documentation/admin-guide/media/rkisp1.rst    |   11 +-
>  .../media/v4l/metafmt-rkisp1.rst              |   57 +-
>  .../platform/rockchip/rkisp1/rkisp1-common.c  |   14 +
>  .../platform/rockchip/rkisp1/rkisp1-common.h  |   38 +-
>  .../platform/rockchip/rkisp1/rkisp1-dev.c     |    9 +-
>  .../platform/rockchip/rkisp1/rkisp1-params.c  | 1016 +++++++++++++++--
>  .../platform/rockchip/rkisp1/rkisp1-regs.h    |   23 +
>  .../platform/rockchip/rkisp1/rkisp1-stats.c   |   51 +-
>  drivers/media/v4l2-core/v4l2-ioctl.c          |    1 +
>  include/uapi/linux/rkisp1-config.h            |  576 ++++++++++
>  include/uapi/linux/videodev2.h                |    1 +
>  11 files changed, 1640 insertions(+), 157 deletions(-)
> 
> --
> 2.45.2
>

Re: [PATCH v7 01/12] media: uapi: rkisp1-config: Add extensible params format

[Hans Verkuil]

On 24/07/2024 10:49, Jacopo Mondi wrote:
> Add to the rkisp1-config.h header data types and documentation of
> the extensible parameters format.
> 
> Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
> ---
>  include/uapi/linux/rkisp1-config.h | 489 +++++++++++++++++++++++++++++
>  1 file changed, 489 insertions(+)
> 
> diff --git a/include/uapi/linux/rkisp1-config.h b/include/uapi/linux/rkisp1-config.h
> index 6eeaf8bf2362..00b09c92cca7 100644
> --- a/include/uapi/linux/rkisp1-config.h
> +++ b/include/uapi/linux/rkisp1-config.h
> @@ -996,4 +996,493 @@ struct rkisp1_stat_buffer {
>  	struct rkisp1_cif_isp_stat params;
>  };
>  
> +/*---------- PART3: Extensible Configuration Parameters  ------------*/
> +
> +/**
> + * enum rkisp1_ext_params_block_type - RkISP1 extensible params block type
> + *
> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS: Black level subtraction
> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC: Defect pixel cluster correction
> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG: Sensor de-gamma
> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN: Auto white balance gains
> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT: ISP filtering
> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM: Bayer de-mosaic
> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK: Cross-talk correction
> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC: Gamma out correction
> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF: De-noise pre-filter
> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH: De-noise pre-filter strength
> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC: Color processing
> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_IE: Image effects
> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC: Lens shading correction
> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS: Auto white balance statistics
> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS: Histogram statistics
> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS: Auto exposure statistics
> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS: Auto-focus statistics
> + */
> +enum rkisp1_ext_params_block_type {
> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS,
> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC,
> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG,
> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN,
> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT,
> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM,
> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK,
> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC,
> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF,
> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH,
> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC,
> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_IE,
> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC,
> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS,
> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS,
> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS,
> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS,
> +};
> +
> +/**
> + * enum rkisp1_ext_params_block_enable - RkISP1 extensible parameter block
> + *					 enable flags
> + *
> + * @RKISP1_EXT_PARAMS_BLOCK_DISABLE: Disable the HW block
> + * @RKISP1_EXT_PARAMS_BLOCK_ENABLE: Enable the HW block
> + */
> +enum rkisp1_ext_params_block_enable {
> +	RKISP1_EXT_PARAMS_BLOCK_DISABLE,
> +	RKISP1_EXT_PARAMS_BLOCK_ENABLE,
> +};
> +
> +/**
> + * struct rkisp1_ext_params_block_header - RkISP1 extensible parameter block
> + *					   header
> + *
> + * This structure represents the common part of all the ISP configuration
> + * blocks. Each parameters block shall embed an instance of this structure type
> + * as its first member, followed by the block-specific configuration data. The
> + * driver inspects this common header to discern the block type and its size and
> + * properly handle the block content by casting it to the correct block-specific
> + * type.
> + *
> + * The @type field is one of the values enumerated by
> + * :c:type:`rkisp1_ext_params_block_type` and specifies how the data should be
> + * interpreted by the driver. The @size field specifies the size of the
> + * parameters block and is used by the driver for validation purposes.
> + *
> + * The @enable field specifies the ISP block enablement state. The possible
> + * enablement states are enumerated by :c:type:`rkisp1_ext_params_block_enable`.
> + * When userspace needs to configure and enable an ISP block it shall fully
> + * populate the block configuration and the @enable flag shall be set to
> + * RKISP1_EXT_PARAMS_BLOCK_ENABLE. When userspace simply wants to disable the
> + * ISP block the @enable flag shall be set to RKISP1_EXT_PARAMS_BLOCK_DISABLE.
> + * The driver ignores the rest of the block configuration structure in this
> + * case.
> + *
> + * If a new configuration of an ISP block has to be applied userspace shall
> + * fully populate the ISP block configuration and set the @enable flag to
> + * RKISP1_EXT_PARAMS_BLOCK_ENABLE.
> + *
> + * Userspace is responsible for correctly populating the parameters block header
> + * fields (@type, @enable and @size) and the block-specific parameters.
> + *
> + * For example:
> + *
> + * .. code-block:: c
> + *
> + *	void populate_bls(struct rkisp1_ext_params_block_header *block) {
> + *		struct rkisp1_ext_params_bls_config *bls =
> + *			(struct rkisp1_ext_params_bls_config *)block;
> + *
> + *		bls->header.type = RKISP1_EXT_PARAMS_BLOCK_ID_BLS;
> + *		bls->header.enable = RKISP1_EXT_PARAMS_BLOCK_ENABLE;
> + *		bls->header.size = sizeof(*bls);
> + *
> + *		bls->config.enable_auto = 0;
> + *		bls->config.fixed_val.r = blackLevelRed_;
> + *		bls->config.fixed_val.gr = blackLevelGreenR_;
> + *		bls->config.fixed_val.gb = blackLevelGreenB_;
> + *		bls->config.fixed_val.b = blackLevelBlue_;
> + *	}
> + *
> + * @type: The parameters block type, see
> + *	  :c:type:`rkisp1_ext_params_block_type`
> + * @enable: The block enable flag, see
> + *	   :c:type:`rkisp1_ext_params_block_enable`
> + * @size: Size (in bytes) of the parameters block, including this header
> + */
> +struct rkisp1_ext_params_block_header {
> +	__u16 type;
> +	__u16 enable;
> +	__u16 size;

I would suggest changing this to '__u32 size;'. It ensures the header is8 bytes
long (much nicer than 6), and if there is ever a block > 65535, then it is supported.

i wonder if, with this change, the 'aligned(8)' attributes are even needed, but
I didn't dig into that.

Did you check with pahole for holes etc. in the datastructures?

Regards,

	Hans

> +} __attribute__((aligned(8)));
> +
> +/**
> + * struct rkisp1_ext_params_bls_config - RkISP1 extensible params BLS config
> + *
> + * RkISP1 extensible parameters Black Level Subtraction configuration block.
> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS`.
> + *
> + * @header: The RkISP1 extensible parameters header, see
> + *	    :c:type:`rkisp1_ext_params_block_header`
> + * @config: Black Level Subtraction configuration, see
> + *	    :c:type:`rkisp1_cif_isp_bls_config`
> + */
> +struct rkisp1_ext_params_bls_config {
> +	struct rkisp1_ext_params_block_header header;
> +	struct rkisp1_cif_isp_bls_config config;
> +} __attribute__((aligned(8)));
> +
> +/**
> + * struct rkisp1_ext_params_dpcc_config - RkISP1 extensible params DPCC config
> + *
> + * RkISP1 extensible parameters Defective Pixel Cluster Correction configuration
> + * block. Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC`.
> + *
> + * @header: The RkISP1 extensible parameters header, see
> + *	    :c:type:`rkisp1_ext_params_block_header`
> + * @config: Defective Pixel Cluster Correction configuration, see
> + *	    :c:type:`rkisp1_cif_isp_dpcc_config`
> + */
> +struct rkisp1_ext_params_dpcc_config {
> +	struct rkisp1_ext_params_block_header header;
> +	struct rkisp1_cif_isp_dpcc_config config;
> +} __attribute__((aligned(8)));
> +
> +/**
> + * struct rkisp1_ext_params_sdg_config - RkISP1 extensible params SDG config
> + *
> + * RkISP1 extensible parameters Sensor Degamma configuration block. Identified
> + * by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG`.
> + *
> + * @header: The RkISP1 extensible parameters header, see
> + *	    :c:type:`rkisp1_ext_params_block_header`
> + * @config: Sensor Degamma configuration, see
> + *	    :c:type:`rkisp1_cif_isp_sdg_config`
> + */
> +struct rkisp1_ext_params_sdg_config {
> +	struct rkisp1_ext_params_block_header header;
> +	struct rkisp1_cif_isp_sdg_config config;
> +} __attribute__((aligned(8)));
> +
> +/**
> + * struct rkisp1_ext_params_lsc_config - RkISP1 extensible params LSC config
> + *
> + * RkISP1 extensible parameters Lens Shading Correction configuration block.
> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC`.
> + *
> + * @header: The RkISP1 extensible parameters header, see
> + *	    :c:type:`rkisp1_ext_params_block_header`
> + * @config: Lens Shading Correction configuration, see
> + *	    :c:type:`rkisp1_cif_isp_lsc_config`
> + */
> +struct rkisp1_ext_params_lsc_config {
> +	struct rkisp1_ext_params_block_header header;
> +	struct rkisp1_cif_isp_lsc_config config;
> +} __attribute__((aligned(8)));
> +
> +/**
> + * struct rkisp1_ext_params_awb_gain_config - RkISP1 extensible params AWB
> + *					      gain config
> + *
> + * RkISP1 extensible parameters Auto-White Balance Gains configuration block.
> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN`.
> + *
> + * @header: The RkISP1 extensible parameters header, see
> + *	    :c:type:`rkisp1_ext_params_block_header`
> + * @config: Auto-White Balance Gains configuration, see
> + *	    :c:type:`rkisp1_cif_isp_awb_gain_config`
> + */
> +struct rkisp1_ext_params_awb_gain_config {
> +	struct rkisp1_ext_params_block_header header;
> +	struct rkisp1_cif_isp_awb_gain_config config;
> +} __attribute__((aligned(8)));
> +
> +/**
> + * struct rkisp1_ext_params_flt_config - RkISP1 extensible params FLT config
> + *
> + * RkISP1 extensible parameters Filter configuration block. Identified by
> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT`.
> + *
> + * @header: The RkISP1 extensible parameters header, see
> + *	    :c:type:`rkisp1_ext_params_block_header`
> + * @config: Filter configuration, see :c:type:`rkisp1_cif_isp_flt_config`
> + */
> +struct rkisp1_ext_params_flt_config {
> +	struct rkisp1_ext_params_block_header header;
> +	struct rkisp1_cif_isp_flt_config config;
> +} __attribute__((aligned(8)));
> +
> +/**
> + * struct rkisp1_ext_params_bdm_config - RkISP1 extensible params BDM config
> + *
> + * RkISP1 extensible parameters Demosaicing configuration block. Identified by
> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM`.
> + *
> + * @header: The RkISP1 extensible parameters header, see
> + *	    :c:type:`rkisp1_ext_params_block_header`
> + * @config: Demosaicing configuration, see :c:type:`rkisp1_cif_isp_bdm_config`
> + */
> +struct rkisp1_ext_params_bdm_config {
> +	struct rkisp1_ext_params_block_header header;
> +	struct rkisp1_cif_isp_bdm_config config;
> +} __attribute__((aligned(8)));
> +
> +/**
> + * struct rkisp1_ext_params_ctk_config - RkISP1 extensible params CTK config
> + *
> + * RkISP1 extensible parameters Cross-Talk configuration block. Identified by
> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK`.
> + *
> + * @header: The RkISP1 extensible parameters header, see
> + *	    :c:type:`rkisp1_ext_params_block_header`
> + * @config: Cross-Talk configuration, see :c:type:`rkisp1_cif_isp_ctk_config`
> + */
> +struct rkisp1_ext_params_ctk_config {
> +	struct rkisp1_ext_params_block_header header;
> +	struct rkisp1_cif_isp_ctk_config config;
> +} __attribute__((aligned(8)));
> +
> +/**
> + * struct rkisp1_ext_params_goc_config - RkISP1 extensible params GOC config
> + *
> + * RkISP1 extensible parameters Gamma-Out configuration block. Identified by
> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC`.
> + *
> + * @header: The RkISP1 extensible parameters header, see
> + *	    :c:type:`rkisp1_ext_params_block_header`
> + * @config: Gamma-Out configuration, see :c:type:`rkisp1_cif_isp_goc_config`
> + */
> +struct rkisp1_ext_params_goc_config {
> +	struct rkisp1_ext_params_block_header header;
> +	struct rkisp1_cif_isp_goc_config config;
> +} __attribute__((aligned(8)));
> +
> +/**
> + * struct rkisp1_ext_params_dpf_config - RkISP1 extensible params DPF config
> + *
> + * RkISP1 extensible parameters De-noise Pre-Filter configuration block.
> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF`.
> + *
> + * @header: The RkISP1 extensible parameters header, see
> + *	    :c:type:`rkisp1_ext_params_block_header`
> + * @config: De-noise Pre-Filter configuration, see
> + *	    :c:type:`rkisp1_cif_isp_dpf_config`
> + */
> +struct rkisp1_ext_params_dpf_config {
> +	struct rkisp1_ext_params_block_header header;
> +	struct rkisp1_cif_isp_dpf_config config;
> +} __attribute__((aligned(8)));
> +
> +/**
> + * struct rkisp1_ext_params_dpf_strength_config - RkISP1 extensible params DPF
> + *						  strength config
> + *
> + * RkISP1 extensible parameters De-noise Pre-Filter strength configuration
> + * block. Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH`.
> + *
> + * @header: The RkISP1 extensible parameters header, see
> + *	    :c:type:`rkisp1_ext_params_block_header`
> + * @config: De-noise Pre-Filter strength configuration, see
> + *	    :c:type:`rkisp1_cif_isp_dpf_strength_config`
> + */
> +struct rkisp1_ext_params_dpf_strength_config {
> +	struct rkisp1_ext_params_block_header header;
> +	struct rkisp1_cif_isp_dpf_strength_config config;
> +} __attribute__((aligned(8)));
> +
> +/**
> + * struct rkisp1_ext_params_cproc_config - RkISP1 extensible params CPROC config
> + *
> + * RkISP1 extensible parameters Color Processing configuration block.
> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC`.
> + *
> + * @header: The RkISP1 extensible parameters header, see
> + *	    :c:type:`rkisp1_ext_params_block_header`
> + * @config: Color processing configuration, see
> + *	    :c:type:`rkisp1_cif_isp_cproc_config`
> + */
> +struct rkisp1_ext_params_cproc_config {
> +	struct rkisp1_ext_params_block_header header;
> +	struct rkisp1_cif_isp_cproc_config config;
> +} __attribute__((aligned(8)));
> +
> +/**
> + * struct rkisp1_ext_params_ie_config - RkISP1 extensible params IE config
> + *
> + * RkISP1 extensible parameters Image Effect configuration block. Identified by
> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_IE`.
> + *
> + * @header: The RkISP1 extensible parameters header, see
> + *	    :c:type:`rkisp1_ext_params_block_header`
> + * @config: Image Effect configuration, see :c:type:`rkisp1_cif_isp_ie_config`
> + */
> +struct rkisp1_ext_params_ie_config {
> +	struct rkisp1_ext_params_block_header header;
> +	struct rkisp1_cif_isp_ie_config config;
> +} __attribute__((aligned(8)));
> +
> +/**
> + * struct rkisp1_ext_params_awb_meas_config - RkISP1 extensible params AWB
> + *					      Meas config
> + *
> + * RkISP1 extensible parameters Auto-White Balance Measurement configuration
> + * block. Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS`.
> + *
> + * @header: The RkISP1 extensible parameters header, see
> + *	    :c:type:`rkisp1_ext_params_block_header`
> + * @config: Auto-White Balance measure configuration, see
> + *	    :c:type:`rkisp1_cif_isp_awb_meas_config`
> + */
> +struct rkisp1_ext_params_awb_meas_config {
> +	struct rkisp1_ext_params_block_header header;
> +	struct rkisp1_cif_isp_awb_meas_config config;
> +} __attribute__((aligned(8)));
> +
> +/**
> + * struct rkisp1_ext_params_hst_config - RkISP1 extensible params Histogram config
> + *
> + * RkISP1 extensible parameters Histogram statistics configuration block.
> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS`.
> + *
> + * @header: The RkISP1 extensible parameters header, see
> + *	    :c:type:`rkisp1_ext_params_block_header`
> + * @config: Histogram statistics configuration, see
> + *	    :c:type:`rkisp1_cif_isp_hst_config`
> + */
> +struct rkisp1_ext_params_hst_config {
> +	struct rkisp1_ext_params_block_header header;
> +	struct rkisp1_cif_isp_hst_config config;
> +} __attribute__((aligned(8)));
> +
> +/**
> + * struct rkisp1_ext_params_aec_config - RkISP1 extensible params AEC config
> + *
> + * RkISP1 extensible parameters Auto-Exposure statistics configuration block.
> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS`.
> + *
> + * @header: The RkISP1 extensible parameters header, see
> + *	    :c:type:`rkisp1_ext_params_block_header`
> + * @config: Auto-Exposure statistics configuration, see
> + *	    :c:type:`rkisp1_cif_isp_aec_config`
> + */
> +struct rkisp1_ext_params_aec_config {
> +	struct rkisp1_ext_params_block_header header;
> +	struct rkisp1_cif_isp_aec_config config;
> +} __attribute__((aligned(8)));
> +
> +/**
> + * struct rkisp1_ext_params_afc_config - RkISP1 extensible params AFC config
> + *
> + * RkISP1 extensible parameters Auto-Focus statistics configuration block.
> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS`.
> + *
> + * @header: The RkISP1 extensible parameters header, see
> + *	    :c:type:`rkisp1_ext_params_block_header`
> + * @config: Auto-Focus statistics configuration, see
> + *	    :c:type:`rkisp1_cif_isp_afc_config`
> + */
> +struct rkisp1_ext_params_afc_config {
> +	struct rkisp1_ext_params_block_header header;
> +	struct rkisp1_cif_isp_afc_config config;
> +} __attribute__((aligned(8)));
> +
> +#define RKISP1_EXT_PARAMS_MAX_SIZE					\
> +	(sizeof(struct rkisp1_ext_params_bls_config)			+\
> +	sizeof(struct rkisp1_ext_params_dpcc_config)			+\
> +	sizeof(struct rkisp1_ext_params_sdg_config)			+\
> +	sizeof(struct rkisp1_ext_params_lsc_config)			+\
> +	sizeof(struct rkisp1_ext_params_awb_gain_config)		+\
> +	sizeof(struct rkisp1_ext_params_flt_config)			+\
> +	sizeof(struct rkisp1_ext_params_bdm_config)			+\
> +	sizeof(struct rkisp1_ext_params_ctk_config)			+\
> +	sizeof(struct rkisp1_ext_params_goc_config)			+\
> +	sizeof(struct rkisp1_ext_params_dpf_config)			+\
> +	sizeof(struct rkisp1_ext_params_dpf_strength_config)		+\
> +	sizeof(struct rkisp1_ext_params_cproc_config)			+\
> +	sizeof(struct rkisp1_ext_params_ie_config)			+\
> +	sizeof(struct rkisp1_ext_params_awb_meas_config)		+\
> +	sizeof(struct rkisp1_ext_params_hst_config)			+\
> +	sizeof(struct rkisp1_ext_params_aec_config)			+\
> +	sizeof(struct rkisp1_ext_params_afc_config))
> +
> +/**
> + * enum rksip1_ext_param_buffer_version - RkISP1 extensible parameters version
> + *
> + * @RKISP1_EXT_PARAM_BUFFER_V1: First version of RkISP1 extensible parameters
> + */
> +enum rksip1_ext_param_buffer_version {
> +	RKISP1_EXT_PARAM_BUFFER_V1 = 1,
> +};
> +
> +/**
> + * struct rkisp1_ext_params_cfg - RkISP1 extensible parameters configuration
> + *
> + * This struct contains the configuration parameters of the RkISP1 ISP
> + * algorithms, serialized by userspace into a data buffer. Each configuration
> + * parameter block is represented by a block-specific structure which contains a
> + * :c:type:`rkisp1_ext_params_block_header` entry as first member. Userspace
> + * populates the @data buffer with configuration parameters for the blocks that
> + * it intends to configure. As a consequence, the data buffer effective size
> + * changes according to the number of ISP blocks that userspace intends to
> + * configure and is set by userspace in the @data_size field.
> + *
> + * The parameters buffer is versioned by the @version field to allow modifying
> + * and extending its definition. Userspace shall populate the @version field to
> + * inform the driver about the version it intends to use. The driver will parse
> + * and handle the @data buffer according to the data layout specific to the
> + * indicated version and return an error if the desired version is not
> + * supported.
> + *
> + * For each ISP block that userspace wants to configure, a block-specific
> + * structure is appended to the @data buffer, one after the other without gaps
> + * in between nor overlaps. Userspace shall populate the @data_size field with
> + * the effective size, in bytes, of the @data buffer.
> + *
> + * The expected memory layout of the parameters buffer is::
> + *
> + *	+-------------------- struct rkisp1_ext_params_cfg -------------------+
> + *	| version = RKISP_EXT_PARAMS_BUFFER_V1;                               |
> + *	| data_size = sizeof(struct rkisp1_ext_params_bls_config)             |
> + *	|           + sizeof(struct rkisp1_ext_params_dpcc_config);           |
> + *	| +------------------------- data  ---------------------------------+ |
> + *	| | +------------- struct rkisp1_ext_params_bls_config -----------+ | |
> + *	| | | +-------- struct rkisp1_ext_params_block_header  ---------+ | | |
> + *	| | | | type = RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS;                | | | |
> + *	| | | | enable = RKISP1_EXT_PARAMS_BLOCK_ENABLE;                | | | |
> + *	| | | | size = sizeof(struct rkisp1_ext_params_bls_config);     | | | |
> + *	| | | +---------------------------------------------------------+ | | |
> + *	| | | +---------- struct rkisp1_cif_isp_bls_config -------------+ | | |
> + *	| | | | enable_auto = 0;                                        | | | |
> + *	| | | | fixed_val.r = 256;                                      | | | |
> + *	| | | | fixed_val.gr = 256;                                     | | | |
> + *	| | | | fixed_val.gb = 256;                                     | | | |
> + *	| | | | fixed_val.b = 256;                                      | | | |
> + *	| | | +---------------------------------------------------------+ | | |
> + *	| | +------------ struct rkisp1_ext_params_dpcc_config -----------+ | |
> + *	| | | +-------- struct rkisp1_ext_params_block_header  ---------+ | | |
> + *	| | | | type = RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC;               | | | |
> + *	| | | | enable = RKISP1_EXT_PARAMS_BLOCK_ENABLE;                | | | |
> + *	| | | | size = sizeof(struct rkisp1_ext_params_dpcc_config);    | | | |
> + *	| | | +---------------------------------------------------------+ | | |
> + *	| | | +---------- struct rkisp1_cif_isp_dpcc_config ------------+ | | |
> + *	| | | | mode = RKISP1_CIF_ISP_DPCC_MODE_STAGE1_ENABLE;          | | | |
> + *	| | | | output_mode =                                           | | | |
> + *	| | | |   RKISP1_CIF_ISP_DPCC_OUTPUT_MODE_STAGE1_INCL_G_CENTER; | | | |
> + *	| | | | set_use = ... ;                                         | | | |
> + *	| | | | ...  = ... ;                                            | | | |
> + *	| | | +---------------------------------------------------------+ | | |
> + *	| | +-------------------------------------------------------------+ | |
> + *	| +-----------------------------------------------------------------+ |
> + *	+---------------------------------------------------------------------+
> + *
> + * @version: The RkISP1 extensible parameters buffer version, see
> + *	     :c:type:`rksip1_ext_param_buffer_version`
> + * @data_size: The RkISP1 configuration data effective size, excluding this
> + *	       header
> + * @data: The RkISP1 extensible configuration data blocks
> + */
> +struct rkisp1_ext_params_cfg {
> +	__u32 version;
> +	__u32 data_size;
> +	__u8 data[RKISP1_EXT_PARAMS_MAX_SIZE];
> +};
> +
>  #endif /* _UAPI_RKISP1_CONFIG_H */

Re: [PATCH v7 01/12] media: uapi: rkisp1-config: Add extensible params format

[Hans Verkuil]

On 30/07/2024 14:11, Hans Verkuil wrote:
> On 24/07/2024 10:49, Jacopo Mondi wrote:
>> Add to the rkisp1-config.h header data types and documentation of
>> the extensible parameters format.
>>
>> Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
>> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
>> Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
>> ---
>>  include/uapi/linux/rkisp1-config.h | 489 +++++++++++++++++++++++++++++
>>  1 file changed, 489 insertions(+)
>>
>> diff --git a/include/uapi/linux/rkisp1-config.h b/include/uapi/linux/rkisp1-config.h
>> index 6eeaf8bf2362..00b09c92cca7 100644
>> --- a/include/uapi/linux/rkisp1-config.h
>> +++ b/include/uapi/linux/rkisp1-config.h
>> @@ -996,4 +996,493 @@ struct rkisp1_stat_buffer {
>>  	struct rkisp1_cif_isp_stat params;
>>  };
>>  
>> +/*---------- PART3: Extensible Configuration Parameters  ------------*/
>> +
>> +/**
>> + * enum rkisp1_ext_params_block_type - RkISP1 extensible params block type
>> + *
>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS: Black level subtraction
>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC: Defect pixel cluster correction
>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG: Sensor de-gamma
>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN: Auto white balance gains
>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT: ISP filtering
>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM: Bayer de-mosaic
>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK: Cross-talk correction
>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC: Gamma out correction
>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF: De-noise pre-filter
>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH: De-noise pre-filter strength
>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC: Color processing
>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_IE: Image effects
>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC: Lens shading correction
>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS: Auto white balance statistics
>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS: Histogram statistics
>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS: Auto exposure statistics
>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS: Auto-focus statistics
>> + */
>> +enum rkisp1_ext_params_block_type {
>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS,
>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC,
>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG,
>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN,
>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT,
>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM,
>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK,
>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC,
>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF,
>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH,
>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC,
>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_IE,
>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC,
>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS,
>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS,
>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS,
>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS,
>> +};
>> +
>> +/**
>> + * enum rkisp1_ext_params_block_enable - RkISP1 extensible parameter block
>> + *					 enable flags
>> + *
>> + * @RKISP1_EXT_PARAMS_BLOCK_DISABLE: Disable the HW block
>> + * @RKISP1_EXT_PARAMS_BLOCK_ENABLE: Enable the HW block
>> + */
>> +enum rkisp1_ext_params_block_enable {
>> +	RKISP1_EXT_PARAMS_BLOCK_DISABLE,
>> +	RKISP1_EXT_PARAMS_BLOCK_ENABLE,
>> +};
>> +
>> +/**
>> + * struct rkisp1_ext_params_block_header - RkISP1 extensible parameter block
>> + *					   header
>> + *
>> + * This structure represents the common part of all the ISP configuration
>> + * blocks. Each parameters block shall embed an instance of this structure type
>> + * as its first member, followed by the block-specific configuration data. The
>> + * driver inspects this common header to discern the block type and its size and
>> + * properly handle the block content by casting it to the correct block-specific
>> + * type.
>> + *
>> + * The @type field is one of the values enumerated by
>> + * :c:type:`rkisp1_ext_params_block_type` and specifies how the data should be
>> + * interpreted by the driver. The @size field specifies the size of the
>> + * parameters block and is used by the driver for validation purposes.
>> + *
>> + * The @enable field specifies the ISP block enablement state. The possible
>> + * enablement states are enumerated by :c:type:`rkisp1_ext_params_block_enable`.
>> + * When userspace needs to configure and enable an ISP block it shall fully
>> + * populate the block configuration and the @enable flag shall be set to
>> + * RKISP1_EXT_PARAMS_BLOCK_ENABLE. When userspace simply wants to disable the
>> + * ISP block the @enable flag shall be set to RKISP1_EXT_PARAMS_BLOCK_DISABLE.
>> + * The driver ignores the rest of the block configuration structure in this
>> + * case.
>> + *
>> + * If a new configuration of an ISP block has to be applied userspace shall
>> + * fully populate the ISP block configuration and set the @enable flag to
>> + * RKISP1_EXT_PARAMS_BLOCK_ENABLE.
>> + *
>> + * Userspace is responsible for correctly populating the parameters block header
>> + * fields (@type, @enable and @size) and the block-specific parameters.
>> + *
>> + * For example:
>> + *
>> + * .. code-block:: c
>> + *
>> + *	void populate_bls(struct rkisp1_ext_params_block_header *block) {
>> + *		struct rkisp1_ext_params_bls_config *bls =
>> + *			(struct rkisp1_ext_params_bls_config *)block;
>> + *
>> + *		bls->header.type = RKISP1_EXT_PARAMS_BLOCK_ID_BLS;
>> + *		bls->header.enable = RKISP1_EXT_PARAMS_BLOCK_ENABLE;
>> + *		bls->header.size = sizeof(*bls);
>> + *
>> + *		bls->config.enable_auto = 0;
>> + *		bls->config.fixed_val.r = blackLevelRed_;
>> + *		bls->config.fixed_val.gr = blackLevelGreenR_;
>> + *		bls->config.fixed_val.gb = blackLevelGreenB_;
>> + *		bls->config.fixed_val.b = blackLevelBlue_;
>> + *	}
>> + *
>> + * @type: The parameters block type, see
>> + *	  :c:type:`rkisp1_ext_params_block_type`
>> + * @enable: The block enable flag, see
>> + *	   :c:type:`rkisp1_ext_params_block_enable`
>> + * @size: Size (in bytes) of the parameters block, including this header
>> + */
>> +struct rkisp1_ext_params_block_header {
>> +	__u16 type;
>> +	__u16 enable;
>> +	__u16 size;
> 
> I would suggest changing this to '__u32 size;'. It ensures the header is8 bytes
> long (much nicer than 6), and if there is ever a block > 65535, then it is supported.
> 
> i wonder if, with this change, the 'aligned(8)' attributes are even needed, but
> I didn't dig into that.

Follow-up: I wonder if this can be a generic v4l2 struct: perhaps the same approach
makes sense for other drivers as well.

Just an idea.

Regards,

	Hans

> 
> Did you check with pahole for holes etc. in the datastructures?
> 
> Regards,
> 
> 	Hans
> 
>> +} __attribute__((aligned(8)));
>> +
>> +/**
>> + * struct rkisp1_ext_params_bls_config - RkISP1 extensible params BLS config
>> + *
>> + * RkISP1 extensible parameters Black Level Subtraction configuration block.
>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS`.
>> + *
>> + * @header: The RkISP1 extensible parameters header, see
>> + *	    :c:type:`rkisp1_ext_params_block_header`
>> + * @config: Black Level Subtraction configuration, see
>> + *	    :c:type:`rkisp1_cif_isp_bls_config`
>> + */
>> +struct rkisp1_ext_params_bls_config {
>> +	struct rkisp1_ext_params_block_header header;
>> +	struct rkisp1_cif_isp_bls_config config;
>> +} __attribute__((aligned(8)));
>> +
>> +/**
>> + * struct rkisp1_ext_params_dpcc_config - RkISP1 extensible params DPCC config
>> + *
>> + * RkISP1 extensible parameters Defective Pixel Cluster Correction configuration
>> + * block. Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC`.
>> + *
>> + * @header: The RkISP1 extensible parameters header, see
>> + *	    :c:type:`rkisp1_ext_params_block_header`
>> + * @config: Defective Pixel Cluster Correction configuration, see
>> + *	    :c:type:`rkisp1_cif_isp_dpcc_config`
>> + */
>> +struct rkisp1_ext_params_dpcc_config {
>> +	struct rkisp1_ext_params_block_header header;
>> +	struct rkisp1_cif_isp_dpcc_config config;
>> +} __attribute__((aligned(8)));
>> +
>> +/**
>> + * struct rkisp1_ext_params_sdg_config - RkISP1 extensible params SDG config
>> + *
>> + * RkISP1 extensible parameters Sensor Degamma configuration block. Identified
>> + * by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG`.
>> + *
>> + * @header: The RkISP1 extensible parameters header, see
>> + *	    :c:type:`rkisp1_ext_params_block_header`
>> + * @config: Sensor Degamma configuration, see
>> + *	    :c:type:`rkisp1_cif_isp_sdg_config`
>> + */
>> +struct rkisp1_ext_params_sdg_config {
>> +	struct rkisp1_ext_params_block_header header;
>> +	struct rkisp1_cif_isp_sdg_config config;
>> +} __attribute__((aligned(8)));
>> +
>> +/**
>> + * struct rkisp1_ext_params_lsc_config - RkISP1 extensible params LSC config
>> + *
>> + * RkISP1 extensible parameters Lens Shading Correction configuration block.
>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC`.
>> + *
>> + * @header: The RkISP1 extensible parameters header, see
>> + *	    :c:type:`rkisp1_ext_params_block_header`
>> + * @config: Lens Shading Correction configuration, see
>> + *	    :c:type:`rkisp1_cif_isp_lsc_config`
>> + */
>> +struct rkisp1_ext_params_lsc_config {
>> +	struct rkisp1_ext_params_block_header header;
>> +	struct rkisp1_cif_isp_lsc_config config;
>> +} __attribute__((aligned(8)));
>> +
>> +/**
>> + * struct rkisp1_ext_params_awb_gain_config - RkISP1 extensible params AWB
>> + *					      gain config
>> + *
>> + * RkISP1 extensible parameters Auto-White Balance Gains configuration block.
>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN`.
>> + *
>> + * @header: The RkISP1 extensible parameters header, see
>> + *	    :c:type:`rkisp1_ext_params_block_header`
>> + * @config: Auto-White Balance Gains configuration, see
>> + *	    :c:type:`rkisp1_cif_isp_awb_gain_config`
>> + */
>> +struct rkisp1_ext_params_awb_gain_config {
>> +	struct rkisp1_ext_params_block_header header;
>> +	struct rkisp1_cif_isp_awb_gain_config config;
>> +} __attribute__((aligned(8)));
>> +
>> +/**
>> + * struct rkisp1_ext_params_flt_config - RkISP1 extensible params FLT config
>> + *
>> + * RkISP1 extensible parameters Filter configuration block. Identified by
>> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT`.
>> + *
>> + * @header: The RkISP1 extensible parameters header, see
>> + *	    :c:type:`rkisp1_ext_params_block_header`
>> + * @config: Filter configuration, see :c:type:`rkisp1_cif_isp_flt_config`
>> + */
>> +struct rkisp1_ext_params_flt_config {
>> +	struct rkisp1_ext_params_block_header header;
>> +	struct rkisp1_cif_isp_flt_config config;
>> +} __attribute__((aligned(8)));
>> +
>> +/**
>> + * struct rkisp1_ext_params_bdm_config - RkISP1 extensible params BDM config
>> + *
>> + * RkISP1 extensible parameters Demosaicing configuration block. Identified by
>> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM`.
>> + *
>> + * @header: The RkISP1 extensible parameters header, see
>> + *	    :c:type:`rkisp1_ext_params_block_header`
>> + * @config: Demosaicing configuration, see :c:type:`rkisp1_cif_isp_bdm_config`
>> + */
>> +struct rkisp1_ext_params_bdm_config {
>> +	struct rkisp1_ext_params_block_header header;
>> +	struct rkisp1_cif_isp_bdm_config config;
>> +} __attribute__((aligned(8)));
>> +
>> +/**
>> + * struct rkisp1_ext_params_ctk_config - RkISP1 extensible params CTK config
>> + *
>> + * RkISP1 extensible parameters Cross-Talk configuration block. Identified by
>> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK`.
>> + *
>> + * @header: The RkISP1 extensible parameters header, see
>> + *	    :c:type:`rkisp1_ext_params_block_header`
>> + * @config: Cross-Talk configuration, see :c:type:`rkisp1_cif_isp_ctk_config`
>> + */
>> +struct rkisp1_ext_params_ctk_config {
>> +	struct rkisp1_ext_params_block_header header;
>> +	struct rkisp1_cif_isp_ctk_config config;
>> +} __attribute__((aligned(8)));
>> +
>> +/**
>> + * struct rkisp1_ext_params_goc_config - RkISP1 extensible params GOC config
>> + *
>> + * RkISP1 extensible parameters Gamma-Out configuration block. Identified by
>> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC`.
>> + *
>> + * @header: The RkISP1 extensible parameters header, see
>> + *	    :c:type:`rkisp1_ext_params_block_header`
>> + * @config: Gamma-Out configuration, see :c:type:`rkisp1_cif_isp_goc_config`
>> + */
>> +struct rkisp1_ext_params_goc_config {
>> +	struct rkisp1_ext_params_block_header header;
>> +	struct rkisp1_cif_isp_goc_config config;
>> +} __attribute__((aligned(8)));
>> +
>> +/**
>> + * struct rkisp1_ext_params_dpf_config - RkISP1 extensible params DPF config
>> + *
>> + * RkISP1 extensible parameters De-noise Pre-Filter configuration block.
>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF`.
>> + *
>> + * @header: The RkISP1 extensible parameters header, see
>> + *	    :c:type:`rkisp1_ext_params_block_header`
>> + * @config: De-noise Pre-Filter configuration, see
>> + *	    :c:type:`rkisp1_cif_isp_dpf_config`
>> + */
>> +struct rkisp1_ext_params_dpf_config {
>> +	struct rkisp1_ext_params_block_header header;
>> +	struct rkisp1_cif_isp_dpf_config config;
>> +} __attribute__((aligned(8)));
>> +
>> +/**
>> + * struct rkisp1_ext_params_dpf_strength_config - RkISP1 extensible params DPF
>> + *						  strength config
>> + *
>> + * RkISP1 extensible parameters De-noise Pre-Filter strength configuration
>> + * block. Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH`.
>> + *
>> + * @header: The RkISP1 extensible parameters header, see
>> + *	    :c:type:`rkisp1_ext_params_block_header`
>> + * @config: De-noise Pre-Filter strength configuration, see
>> + *	    :c:type:`rkisp1_cif_isp_dpf_strength_config`
>> + */
>> +struct rkisp1_ext_params_dpf_strength_config {
>> +	struct rkisp1_ext_params_block_header header;
>> +	struct rkisp1_cif_isp_dpf_strength_config config;
>> +} __attribute__((aligned(8)));
>> +
>> +/**
>> + * struct rkisp1_ext_params_cproc_config - RkISP1 extensible params CPROC config
>> + *
>> + * RkISP1 extensible parameters Color Processing configuration block.
>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC`.
>> + *
>> + * @header: The RkISP1 extensible parameters header, see
>> + *	    :c:type:`rkisp1_ext_params_block_header`
>> + * @config: Color processing configuration, see
>> + *	    :c:type:`rkisp1_cif_isp_cproc_config`
>> + */
>> +struct rkisp1_ext_params_cproc_config {
>> +	struct rkisp1_ext_params_block_header header;
>> +	struct rkisp1_cif_isp_cproc_config config;
>> +} __attribute__((aligned(8)));
>> +
>> +/**
>> + * struct rkisp1_ext_params_ie_config - RkISP1 extensible params IE config
>> + *
>> + * RkISP1 extensible parameters Image Effect configuration block. Identified by
>> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_IE`.
>> + *
>> + * @header: The RkISP1 extensible parameters header, see
>> + *	    :c:type:`rkisp1_ext_params_block_header`
>> + * @config: Image Effect configuration, see :c:type:`rkisp1_cif_isp_ie_config`
>> + */
>> +struct rkisp1_ext_params_ie_config {
>> +	struct rkisp1_ext_params_block_header header;
>> +	struct rkisp1_cif_isp_ie_config config;
>> +} __attribute__((aligned(8)));
>> +
>> +/**
>> + * struct rkisp1_ext_params_awb_meas_config - RkISP1 extensible params AWB
>> + *					      Meas config
>> + *
>> + * RkISP1 extensible parameters Auto-White Balance Measurement configuration
>> + * block. Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS`.
>> + *
>> + * @header: The RkISP1 extensible parameters header, see
>> + *	    :c:type:`rkisp1_ext_params_block_header`
>> + * @config: Auto-White Balance measure configuration, see
>> + *	    :c:type:`rkisp1_cif_isp_awb_meas_config`
>> + */
>> +struct rkisp1_ext_params_awb_meas_config {
>> +	struct rkisp1_ext_params_block_header header;
>> +	struct rkisp1_cif_isp_awb_meas_config config;
>> +} __attribute__((aligned(8)));
>> +
>> +/**
>> + * struct rkisp1_ext_params_hst_config - RkISP1 extensible params Histogram config
>> + *
>> + * RkISP1 extensible parameters Histogram statistics configuration block.
>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS`.
>> + *
>> + * @header: The RkISP1 extensible parameters header, see
>> + *	    :c:type:`rkisp1_ext_params_block_header`
>> + * @config: Histogram statistics configuration, see
>> + *	    :c:type:`rkisp1_cif_isp_hst_config`
>> + */
>> +struct rkisp1_ext_params_hst_config {
>> +	struct rkisp1_ext_params_block_header header;
>> +	struct rkisp1_cif_isp_hst_config config;
>> +} __attribute__((aligned(8)));
>> +
>> +/**
>> + * struct rkisp1_ext_params_aec_config - RkISP1 extensible params AEC config
>> + *
>> + * RkISP1 extensible parameters Auto-Exposure statistics configuration block.
>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS`.
>> + *
>> + * @header: The RkISP1 extensible parameters header, see
>> + *	    :c:type:`rkisp1_ext_params_block_header`
>> + * @config: Auto-Exposure statistics configuration, see
>> + *	    :c:type:`rkisp1_cif_isp_aec_config`
>> + */
>> +struct rkisp1_ext_params_aec_config {
>> +	struct rkisp1_ext_params_block_header header;
>> +	struct rkisp1_cif_isp_aec_config config;
>> +} __attribute__((aligned(8)));
>> +
>> +/**
>> + * struct rkisp1_ext_params_afc_config - RkISP1 extensible params AFC config
>> + *
>> + * RkISP1 extensible parameters Auto-Focus statistics configuration block.
>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS`.
>> + *
>> + * @header: The RkISP1 extensible parameters header, see
>> + *	    :c:type:`rkisp1_ext_params_block_header`
>> + * @config: Auto-Focus statistics configuration, see
>> + *	    :c:type:`rkisp1_cif_isp_afc_config`
>> + */
>> +struct rkisp1_ext_params_afc_config {
>> +	struct rkisp1_ext_params_block_header header;
>> +	struct rkisp1_cif_isp_afc_config config;
>> +} __attribute__((aligned(8)));
>> +
>> +#define RKISP1_EXT_PARAMS_MAX_SIZE					\
>> +	(sizeof(struct rkisp1_ext_params_bls_config)			+\
>> +	sizeof(struct rkisp1_ext_params_dpcc_config)			+\
>> +	sizeof(struct rkisp1_ext_params_sdg_config)			+\
>> +	sizeof(struct rkisp1_ext_params_lsc_config)			+\
>> +	sizeof(struct rkisp1_ext_params_awb_gain_config)		+\
>> +	sizeof(struct rkisp1_ext_params_flt_config)			+\
>> +	sizeof(struct rkisp1_ext_params_bdm_config)			+\
>> +	sizeof(struct rkisp1_ext_params_ctk_config)			+\
>> +	sizeof(struct rkisp1_ext_params_goc_config)			+\
>> +	sizeof(struct rkisp1_ext_params_dpf_config)			+\
>> +	sizeof(struct rkisp1_ext_params_dpf_strength_config)		+\
>> +	sizeof(struct rkisp1_ext_params_cproc_config)			+\
>> +	sizeof(struct rkisp1_ext_params_ie_config)			+\
>> +	sizeof(struct rkisp1_ext_params_awb_meas_config)		+\
>> +	sizeof(struct rkisp1_ext_params_hst_config)			+\
>> +	sizeof(struct rkisp1_ext_params_aec_config)			+\
>> +	sizeof(struct rkisp1_ext_params_afc_config))
>> +
>> +/**
>> + * enum rksip1_ext_param_buffer_version - RkISP1 extensible parameters version
>> + *
>> + * @RKISP1_EXT_PARAM_BUFFER_V1: First version of RkISP1 extensible parameters
>> + */
>> +enum rksip1_ext_param_buffer_version {
>> +	RKISP1_EXT_PARAM_BUFFER_V1 = 1,
>> +};
>> +
>> +/**
>> + * struct rkisp1_ext_params_cfg - RkISP1 extensible parameters configuration
>> + *
>> + * This struct contains the configuration parameters of the RkISP1 ISP
>> + * algorithms, serialized by userspace into a data buffer. Each configuration
>> + * parameter block is represented by a block-specific structure which contains a
>> + * :c:type:`rkisp1_ext_params_block_header` entry as first member. Userspace
>> + * populates the @data buffer with configuration parameters for the blocks that
>> + * it intends to configure. As a consequence, the data buffer effective size
>> + * changes according to the number of ISP blocks that userspace intends to
>> + * configure and is set by userspace in the @data_size field.
>> + *
>> + * The parameters buffer is versioned by the @version field to allow modifying
>> + * and extending its definition. Userspace shall populate the @version field to
>> + * inform the driver about the version it intends to use. The driver will parse
>> + * and handle the @data buffer according to the data layout specific to the
>> + * indicated version and return an error if the desired version is not
>> + * supported.
>> + *
>> + * For each ISP block that userspace wants to configure, a block-specific
>> + * structure is appended to the @data buffer, one after the other without gaps
>> + * in between nor overlaps. Userspace shall populate the @data_size field with
>> + * the effective size, in bytes, of the @data buffer.
>> + *
>> + * The expected memory layout of the parameters buffer is::
>> + *
>> + *	+-------------------- struct rkisp1_ext_params_cfg -------------------+
>> + *	| version = RKISP_EXT_PARAMS_BUFFER_V1;                               |
>> + *	| data_size = sizeof(struct rkisp1_ext_params_bls_config)             |
>> + *	|           + sizeof(struct rkisp1_ext_params_dpcc_config);           |
>> + *	| +------------------------- data  ---------------------------------+ |
>> + *	| | +------------- struct rkisp1_ext_params_bls_config -----------+ | |
>> + *	| | | +-------- struct rkisp1_ext_params_block_header  ---------+ | | |
>> + *	| | | | type = RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS;                | | | |
>> + *	| | | | enable = RKISP1_EXT_PARAMS_BLOCK_ENABLE;                | | | |
>> + *	| | | | size = sizeof(struct rkisp1_ext_params_bls_config);     | | | |
>> + *	| | | +---------------------------------------------------------+ | | |
>> + *	| | | +---------- struct rkisp1_cif_isp_bls_config -------------+ | | |
>> + *	| | | | enable_auto = 0;                                        | | | |
>> + *	| | | | fixed_val.r = 256;                                      | | | |
>> + *	| | | | fixed_val.gr = 256;                                     | | | |
>> + *	| | | | fixed_val.gb = 256;                                     | | | |
>> + *	| | | | fixed_val.b = 256;                                      | | | |
>> + *	| | | +---------------------------------------------------------+ | | |
>> + *	| | +------------ struct rkisp1_ext_params_dpcc_config -----------+ | |
>> + *	| | | +-------- struct rkisp1_ext_params_block_header  ---------+ | | |
>> + *	| | | | type = RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC;               | | | |
>> + *	| | | | enable = RKISP1_EXT_PARAMS_BLOCK_ENABLE;                | | | |
>> + *	| | | | size = sizeof(struct rkisp1_ext_params_dpcc_config);    | | | |
>> + *	| | | +---------------------------------------------------------+ | | |
>> + *	| | | +---------- struct rkisp1_cif_isp_dpcc_config ------------+ | | |
>> + *	| | | | mode = RKISP1_CIF_ISP_DPCC_MODE_STAGE1_ENABLE;          | | | |
>> + *	| | | | output_mode =                                           | | | |
>> + *	| | | |   RKISP1_CIF_ISP_DPCC_OUTPUT_MODE_STAGE1_INCL_G_CENTER; | | | |
>> + *	| | | | set_use = ... ;                                         | | | |
>> + *	| | | | ...  = ... ;                                            | | | |
>> + *	| | | +---------------------------------------------------------+ | | |
>> + *	| | +-------------------------------------------------------------+ | |
>> + *	| +-----------------------------------------------------------------+ |
>> + *	+---------------------------------------------------------------------+
>> + *
>> + * @version: The RkISP1 extensible parameters buffer version, see
>> + *	     :c:type:`rksip1_ext_param_buffer_version`
>> + * @data_size: The RkISP1 configuration data effective size, excluding this
>> + *	       header
>> + * @data: The RkISP1 extensible configuration data blocks
>> + */
>> +struct rkisp1_ext_params_cfg {
>> +	__u32 version;
>> +	__u32 data_size;
>> +	__u8 data[RKISP1_EXT_PARAMS_MAX_SIZE];
>> +};
>> +
>>  #endif /* _UAPI_RKISP1_CONFIG_H */
> 
> 

Re: [PATCH v7 01/12] media: uapi: rkisp1-config: Add extensible params format

[Laurent Pinchart]

Hi Hans,

On Tue, Jul 30, 2024 at 02:11:12PM +0200, Hans Verkuil wrote:
> On 24/07/2024 10:49, Jacopo Mondi wrote:
> > Add to the rkisp1-config.h header data types and documentation of
> > the extensible parameters format.
> > 
> > Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
> > Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
> > ---
> >  include/uapi/linux/rkisp1-config.h | 489 +++++++++++++++++++++++++++++
> >  1 file changed, 489 insertions(+)
> > 
> > diff --git a/include/uapi/linux/rkisp1-config.h b/include/uapi/linux/rkisp1-config.h
> > index 6eeaf8bf2362..00b09c92cca7 100644
> > --- a/include/uapi/linux/rkisp1-config.h
> > +++ b/include/uapi/linux/rkisp1-config.h
> > @@ -996,4 +996,493 @@ struct rkisp1_stat_buffer {
> >  	struct rkisp1_cif_isp_stat params;
> >  };
> >  
> > +/*---------- PART3: Extensible Configuration Parameters  ------------*/
> > +
> > +/**
> > + * enum rkisp1_ext_params_block_type - RkISP1 extensible params block type
> > + *
> > + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS: Black level subtraction
> > + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC: Defect pixel cluster correction
> > + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG: Sensor de-gamma
> > + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN: Auto white balance gains
> > + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT: ISP filtering
> > + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM: Bayer de-mosaic
> > + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK: Cross-talk correction
> > + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC: Gamma out correction
> > + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF: De-noise pre-filter
> > + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH: De-noise pre-filter strength
> > + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC: Color processing
> > + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_IE: Image effects
> > + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC: Lens shading correction
> > + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS: Auto white balance statistics
> > + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS: Histogram statistics
> > + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS: Auto exposure statistics
> > + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS: Auto-focus statistics
> > + */
> > +enum rkisp1_ext_params_block_type {
> > +	RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS,
> > +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC,
> > +	RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG,
> > +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN,
> > +	RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT,
> > +	RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM,
> > +	RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK,
> > +	RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC,
> > +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF,
> > +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH,
> > +	RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC,
> > +	RKISP1_EXT_PARAMS_BLOCK_TYPE_IE,
> > +	RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC,
> > +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS,
> > +	RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS,
> > +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS,
> > +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS,
> > +};
> > +
> > +/**
> > + * enum rkisp1_ext_params_block_enable - RkISP1 extensible parameter block
> > + *					 enable flags
> > + *
> > + * @RKISP1_EXT_PARAMS_BLOCK_DISABLE: Disable the HW block
> > + * @RKISP1_EXT_PARAMS_BLOCK_ENABLE: Enable the HW block
> > + */
> > +enum rkisp1_ext_params_block_enable {
> > +	RKISP1_EXT_PARAMS_BLOCK_DISABLE,
> > +	RKISP1_EXT_PARAMS_BLOCK_ENABLE,
> > +};
> > +
> > +/**
> > + * struct rkisp1_ext_params_block_header - RkISP1 extensible parameter block
> > + *					   header
> > + *
> > + * This structure represents the common part of all the ISP configuration
> > + * blocks. Each parameters block shall embed an instance of this structure type
> > + * as its first member, followed by the block-specific configuration data. The
> > + * driver inspects this common header to discern the block type and its size and
> > + * properly handle the block content by casting it to the correct block-specific
> > + * type.
> > + *
> > + * The @type field is one of the values enumerated by
> > + * :c:type:`rkisp1_ext_params_block_type` and specifies how the data should be
> > + * interpreted by the driver. The @size field specifies the size of the
> > + * parameters block and is used by the driver for validation purposes.
> > + *
> > + * The @enable field specifies the ISP block enablement state. The possible
> > + * enablement states are enumerated by :c:type:`rkisp1_ext_params_block_enable`.
> > + * When userspace needs to configure and enable an ISP block it shall fully
> > + * populate the block configuration and the @enable flag shall be set to
> > + * RKISP1_EXT_PARAMS_BLOCK_ENABLE. When userspace simply wants to disable the
> > + * ISP block the @enable flag shall be set to RKISP1_EXT_PARAMS_BLOCK_DISABLE.
> > + * The driver ignores the rest of the block configuration structure in this
> > + * case.
> > + *
> > + * If a new configuration of an ISP block has to be applied userspace shall
> > + * fully populate the ISP block configuration and set the @enable flag to
> > + * RKISP1_EXT_PARAMS_BLOCK_ENABLE.
> > + *
> > + * Userspace is responsible for correctly populating the parameters block header
> > + * fields (@type, @enable and @size) and the block-specific parameters.
> > + *
> > + * For example:
> > + *
> > + * .. code-block:: c
> > + *
> > + *	void populate_bls(struct rkisp1_ext_params_block_header *block) {
> > + *		struct rkisp1_ext_params_bls_config *bls =
> > + *			(struct rkisp1_ext_params_bls_config *)block;
> > + *
> > + *		bls->header.type = RKISP1_EXT_PARAMS_BLOCK_ID_BLS;
> > + *		bls->header.enable = RKISP1_EXT_PARAMS_BLOCK_ENABLE;
> > + *		bls->header.size = sizeof(*bls);
> > + *
> > + *		bls->config.enable_auto = 0;
> > + *		bls->config.fixed_val.r = blackLevelRed_;
> > + *		bls->config.fixed_val.gr = blackLevelGreenR_;
> > + *		bls->config.fixed_val.gb = blackLevelGreenB_;
> > + *		bls->config.fixed_val.b = blackLevelBlue_;
> > + *	}
> > + *
> > + * @type: The parameters block type, see
> > + *	  :c:type:`rkisp1_ext_params_block_type`
> > + * @enable: The block enable flag, see
> > + *	   :c:type:`rkisp1_ext_params_block_enable`
> > + * @size: Size (in bytes) of the parameters block, including this header
> > + */
> > +struct rkisp1_ext_params_block_header {
> > +	__u16 type;
> > +	__u16 enable;
> > +	__u16 size;
> 
> I would suggest changing this to '__u32 size;'. It ensures the header is8 bytes
> long (much nicer than 6), and if there is ever a block > 65535, then it is supported.

I'm pretty confident we will never need a block size larger than 64kB.
That would mean more than 64kB of data written to hardware
registers/SRAM for a single processing block, and it would be incredibly
expensive in terms of hardware. Keeping size a __u16 means we have two
bytes of reserved space we could possibly use later, which may come
handy. Blocks > 64kB could still be supported in the future by defining
a new version of the parameters format (RKISP1_EXT_PARAM_BUFFER_V2)
without needing a different 4CC.

This being said, the opposite argument can be made, that a 32-bit size
could come handy if we ever have larger blocks, and a new version of the
parameters format could be used if we ever need to add more fields to
the block header. I won't insist either way.

> i wonder if, with this change, the 'aligned(8)' attributes are even needed, but
> I didn't dig into that.

The header would become 8-bytes long, but its larger field would still
be 4-bytes long, so the compiler would only enforce 4-bytes aligned
AFAIK.

> Did you check with pahole for holes etc. in the datastructures?

That's a good idea in any case.

> > +} __attribute__((aligned(8)));
> > +
> > +/**
> > + * struct rkisp1_ext_params_bls_config - RkISP1 extensible params BLS config
> > + *
> > + * RkISP1 extensible parameters Black Level Subtraction configuration block.
> > + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS`.
> > + *
> > + * @header: The RkISP1 extensible parameters header, see
> > + *	    :c:type:`rkisp1_ext_params_block_header`
> > + * @config: Black Level Subtraction configuration, see
> > + *	    :c:type:`rkisp1_cif_isp_bls_config`
> > + */
> > +struct rkisp1_ext_params_bls_config {
> > +	struct rkisp1_ext_params_block_header header;
> > +	struct rkisp1_cif_isp_bls_config config;
> > +} __attribute__((aligned(8)));
> > +
> > +/**
> > + * struct rkisp1_ext_params_dpcc_config - RkISP1 extensible params DPCC config
> > + *
> > + * RkISP1 extensible parameters Defective Pixel Cluster Correction configuration
> > + * block. Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC`.
> > + *
> > + * @header: The RkISP1 extensible parameters header, see
> > + *	    :c:type:`rkisp1_ext_params_block_header`
> > + * @config: Defective Pixel Cluster Correction configuration, see
> > + *	    :c:type:`rkisp1_cif_isp_dpcc_config`
> > + */
> > +struct rkisp1_ext_params_dpcc_config {
> > +	struct rkisp1_ext_params_block_header header;
> > +	struct rkisp1_cif_isp_dpcc_config config;
> > +} __attribute__((aligned(8)));
> > +
> > +/**
> > + * struct rkisp1_ext_params_sdg_config - RkISP1 extensible params SDG config
> > + *
> > + * RkISP1 extensible parameters Sensor Degamma configuration block. Identified
> > + * by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG`.
> > + *
> > + * @header: The RkISP1 extensible parameters header, see
> > + *	    :c:type:`rkisp1_ext_params_block_header`
> > + * @config: Sensor Degamma configuration, see
> > + *	    :c:type:`rkisp1_cif_isp_sdg_config`
> > + */
> > +struct rkisp1_ext_params_sdg_config {
> > +	struct rkisp1_ext_params_block_header header;
> > +	struct rkisp1_cif_isp_sdg_config config;
> > +} __attribute__((aligned(8)));
> > +
> > +/**
> > + * struct rkisp1_ext_params_lsc_config - RkISP1 extensible params LSC config
> > + *
> > + * RkISP1 extensible parameters Lens Shading Correction configuration block.
> > + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC`.
> > + *
> > + * @header: The RkISP1 extensible parameters header, see
> > + *	    :c:type:`rkisp1_ext_params_block_header`
> > + * @config: Lens Shading Correction configuration, see
> > + *	    :c:type:`rkisp1_cif_isp_lsc_config`
> > + */
> > +struct rkisp1_ext_params_lsc_config {
> > +	struct rkisp1_ext_params_block_header header;
> > +	struct rkisp1_cif_isp_lsc_config config;
> > +} __attribute__((aligned(8)));
> > +
> > +/**
> > + * struct rkisp1_ext_params_awb_gain_config - RkISP1 extensible params AWB
> > + *					      gain config
> > + *
> > + * RkISP1 extensible parameters Auto-White Balance Gains configuration block.
> > + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN`.
> > + *
> > + * @header: The RkISP1 extensible parameters header, see
> > + *	    :c:type:`rkisp1_ext_params_block_header`
> > + * @config: Auto-White Balance Gains configuration, see
> > + *	    :c:type:`rkisp1_cif_isp_awb_gain_config`
> > + */
> > +struct rkisp1_ext_params_awb_gain_config {
> > +	struct rkisp1_ext_params_block_header header;
> > +	struct rkisp1_cif_isp_awb_gain_config config;
> > +} __attribute__((aligned(8)));
> > +
> > +/**
> > + * struct rkisp1_ext_params_flt_config - RkISP1 extensible params FLT config
> > + *
> > + * RkISP1 extensible parameters Filter configuration block. Identified by
> > + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT`.
> > + *
> > + * @header: The RkISP1 extensible parameters header, see
> > + *	    :c:type:`rkisp1_ext_params_block_header`
> > + * @config: Filter configuration, see :c:type:`rkisp1_cif_isp_flt_config`
> > + */
> > +struct rkisp1_ext_params_flt_config {
> > +	struct rkisp1_ext_params_block_header header;
> > +	struct rkisp1_cif_isp_flt_config config;
> > +} __attribute__((aligned(8)));
> > +
> > +/**
> > + * struct rkisp1_ext_params_bdm_config - RkISP1 extensible params BDM config
> > + *
> > + * RkISP1 extensible parameters Demosaicing configuration block. Identified by
> > + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM`.
> > + *
> > + * @header: The RkISP1 extensible parameters header, see
> > + *	    :c:type:`rkisp1_ext_params_block_header`
> > + * @config: Demosaicing configuration, see :c:type:`rkisp1_cif_isp_bdm_config`
> > + */
> > +struct rkisp1_ext_params_bdm_config {
> > +	struct rkisp1_ext_params_block_header header;
> > +	struct rkisp1_cif_isp_bdm_config config;
> > +} __attribute__((aligned(8)));
> > +
> > +/**
> > + * struct rkisp1_ext_params_ctk_config - RkISP1 extensible params CTK config
> > + *
> > + * RkISP1 extensible parameters Cross-Talk configuration block. Identified by
> > + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK`.
> > + *
> > + * @header: The RkISP1 extensible parameters header, see
> > + *	    :c:type:`rkisp1_ext_params_block_header`
> > + * @config: Cross-Talk configuration, see :c:type:`rkisp1_cif_isp_ctk_config`
> > + */
> > +struct rkisp1_ext_params_ctk_config {
> > +	struct rkisp1_ext_params_block_header header;
> > +	struct rkisp1_cif_isp_ctk_config config;
> > +} __attribute__((aligned(8)));
> > +
> > +/**
> > + * struct rkisp1_ext_params_goc_config - RkISP1 extensible params GOC config
> > + *
> > + * RkISP1 extensible parameters Gamma-Out configuration block. Identified by
> > + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC`.
> > + *
> > + * @header: The RkISP1 extensible parameters header, see
> > + *	    :c:type:`rkisp1_ext_params_block_header`
> > + * @config: Gamma-Out configuration, see :c:type:`rkisp1_cif_isp_goc_config`
> > + */
> > +struct rkisp1_ext_params_goc_config {
> > +	struct rkisp1_ext_params_block_header header;
> > +	struct rkisp1_cif_isp_goc_config config;
> > +} __attribute__((aligned(8)));
> > +
> > +/**
> > + * struct rkisp1_ext_params_dpf_config - RkISP1 extensible params DPF config
> > + *
> > + * RkISP1 extensible parameters De-noise Pre-Filter configuration block.
> > + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF`.
> > + *
> > + * @header: The RkISP1 extensible parameters header, see
> > + *	    :c:type:`rkisp1_ext_params_block_header`
> > + * @config: De-noise Pre-Filter configuration, see
> > + *	    :c:type:`rkisp1_cif_isp_dpf_config`
> > + */
> > +struct rkisp1_ext_params_dpf_config {
> > +	struct rkisp1_ext_params_block_header header;
> > +	struct rkisp1_cif_isp_dpf_config config;
> > +} __attribute__((aligned(8)));
> > +
> > +/**
> > + * struct rkisp1_ext_params_dpf_strength_config - RkISP1 extensible params DPF
> > + *						  strength config
> > + *
> > + * RkISP1 extensible parameters De-noise Pre-Filter strength configuration
> > + * block. Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH`.
> > + *
> > + * @header: The RkISP1 extensible parameters header, see
> > + *	    :c:type:`rkisp1_ext_params_block_header`
> > + * @config: De-noise Pre-Filter strength configuration, see
> > + *	    :c:type:`rkisp1_cif_isp_dpf_strength_config`
> > + */
> > +struct rkisp1_ext_params_dpf_strength_config {
> > +	struct rkisp1_ext_params_block_header header;
> > +	struct rkisp1_cif_isp_dpf_strength_config config;
> > +} __attribute__((aligned(8)));
> > +
> > +/**
> > + * struct rkisp1_ext_params_cproc_config - RkISP1 extensible params CPROC config
> > + *
> > + * RkISP1 extensible parameters Color Processing configuration block.
> > + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC`.
> > + *
> > + * @header: The RkISP1 extensible parameters header, see
> > + *	    :c:type:`rkisp1_ext_params_block_header`
> > + * @config: Color processing configuration, see
> > + *	    :c:type:`rkisp1_cif_isp_cproc_config`
> > + */
> > +struct rkisp1_ext_params_cproc_config {
> > +	struct rkisp1_ext_params_block_header header;
> > +	struct rkisp1_cif_isp_cproc_config config;
> > +} __attribute__((aligned(8)));
> > +
> > +/**
> > + * struct rkisp1_ext_params_ie_config - RkISP1 extensible params IE config
> > + *
> > + * RkISP1 extensible parameters Image Effect configuration block. Identified by
> > + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_IE`.
> > + *
> > + * @header: The RkISP1 extensible parameters header, see
> > + *	    :c:type:`rkisp1_ext_params_block_header`
> > + * @config: Image Effect configuration, see :c:type:`rkisp1_cif_isp_ie_config`
> > + */
> > +struct rkisp1_ext_params_ie_config {
> > +	struct rkisp1_ext_params_block_header header;
> > +	struct rkisp1_cif_isp_ie_config config;
> > +} __attribute__((aligned(8)));
> > +
> > +/**
> > + * struct rkisp1_ext_params_awb_meas_config - RkISP1 extensible params AWB
> > + *					      Meas config
> > + *
> > + * RkISP1 extensible parameters Auto-White Balance Measurement configuration
> > + * block. Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS`.
> > + *
> > + * @header: The RkISP1 extensible parameters header, see
> > + *	    :c:type:`rkisp1_ext_params_block_header`
> > + * @config: Auto-White Balance measure configuration, see
> > + *	    :c:type:`rkisp1_cif_isp_awb_meas_config`
> > + */
> > +struct rkisp1_ext_params_awb_meas_config {
> > +	struct rkisp1_ext_params_block_header header;
> > +	struct rkisp1_cif_isp_awb_meas_config config;
> > +} __attribute__((aligned(8)));
> > +
> > +/**
> > + * struct rkisp1_ext_params_hst_config - RkISP1 extensible params Histogram config
> > + *
> > + * RkISP1 extensible parameters Histogram statistics configuration block.
> > + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS`.
> > + *
> > + * @header: The RkISP1 extensible parameters header, see
> > + *	    :c:type:`rkisp1_ext_params_block_header`
> > + * @config: Histogram statistics configuration, see
> > + *	    :c:type:`rkisp1_cif_isp_hst_config`
> > + */
> > +struct rkisp1_ext_params_hst_config {
> > +	struct rkisp1_ext_params_block_header header;
> > +	struct rkisp1_cif_isp_hst_config config;
> > +} __attribute__((aligned(8)));
> > +
> > +/**
> > + * struct rkisp1_ext_params_aec_config - RkISP1 extensible params AEC config
> > + *
> > + * RkISP1 extensible parameters Auto-Exposure statistics configuration block.
> > + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS`.
> > + *
> > + * @header: The RkISP1 extensible parameters header, see
> > + *	    :c:type:`rkisp1_ext_params_block_header`
> > + * @config: Auto-Exposure statistics configuration, see
> > + *	    :c:type:`rkisp1_cif_isp_aec_config`
> > + */
> > +struct rkisp1_ext_params_aec_config {
> > +	struct rkisp1_ext_params_block_header header;
> > +	struct rkisp1_cif_isp_aec_config config;
> > +} __attribute__((aligned(8)));
> > +
> > +/**
> > + * struct rkisp1_ext_params_afc_config - RkISP1 extensible params AFC config
> > + *
> > + * RkISP1 extensible parameters Auto-Focus statistics configuration block.
> > + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS`.
> > + *
> > + * @header: The RkISP1 extensible parameters header, see
> > + *	    :c:type:`rkisp1_ext_params_block_header`
> > + * @config: Auto-Focus statistics configuration, see
> > + *	    :c:type:`rkisp1_cif_isp_afc_config`
> > + */
> > +struct rkisp1_ext_params_afc_config {
> > +	struct rkisp1_ext_params_block_header header;
> > +	struct rkisp1_cif_isp_afc_config config;
> > +} __attribute__((aligned(8)));
> > +
> > +#define RKISP1_EXT_PARAMS_MAX_SIZE					\
> > +	(sizeof(struct rkisp1_ext_params_bls_config)			+\
> > +	sizeof(struct rkisp1_ext_params_dpcc_config)			+\
> > +	sizeof(struct rkisp1_ext_params_sdg_config)			+\
> > +	sizeof(struct rkisp1_ext_params_lsc_config)			+\
> > +	sizeof(struct rkisp1_ext_params_awb_gain_config)		+\
> > +	sizeof(struct rkisp1_ext_params_flt_config)			+\
> > +	sizeof(struct rkisp1_ext_params_bdm_config)			+\
> > +	sizeof(struct rkisp1_ext_params_ctk_config)			+\
> > +	sizeof(struct rkisp1_ext_params_goc_config)			+\
> > +	sizeof(struct rkisp1_ext_params_dpf_config)			+\
> > +	sizeof(struct rkisp1_ext_params_dpf_strength_config)		+\
> > +	sizeof(struct rkisp1_ext_params_cproc_config)			+\
> > +	sizeof(struct rkisp1_ext_params_ie_config)			+\
> > +	sizeof(struct rkisp1_ext_params_awb_meas_config)		+\
> > +	sizeof(struct rkisp1_ext_params_hst_config)			+\
> > +	sizeof(struct rkisp1_ext_params_aec_config)			+\
> > +	sizeof(struct rkisp1_ext_params_afc_config))
> > +
> > +/**
> > + * enum rksip1_ext_param_buffer_version - RkISP1 extensible parameters version
> > + *
> > + * @RKISP1_EXT_PARAM_BUFFER_V1: First version of RkISP1 extensible parameters
> > + */
> > +enum rksip1_ext_param_buffer_version {
> > +	RKISP1_EXT_PARAM_BUFFER_V1 = 1,
> > +};
> > +
> > +/**
> > + * struct rkisp1_ext_params_cfg - RkISP1 extensible parameters configuration
> > + *
> > + * This struct contains the configuration parameters of the RkISP1 ISP
> > + * algorithms, serialized by userspace into a data buffer. Each configuration
> > + * parameter block is represented by a block-specific structure which contains a
> > + * :c:type:`rkisp1_ext_params_block_header` entry as first member. Userspace
> > + * populates the @data buffer with configuration parameters for the blocks that
> > + * it intends to configure. As a consequence, the data buffer effective size
> > + * changes according to the number of ISP blocks that userspace intends to
> > + * configure and is set by userspace in the @data_size field.
> > + *
> > + * The parameters buffer is versioned by the @version field to allow modifying
> > + * and extending its definition. Userspace shall populate the @version field to
> > + * inform the driver about the version it intends to use. The driver will parse
> > + * and handle the @data buffer according to the data layout specific to the
> > + * indicated version and return an error if the desired version is not
> > + * supported.
> > + *
> > + * For each ISP block that userspace wants to configure, a block-specific
> > + * structure is appended to the @data buffer, one after the other without gaps
> > + * in between nor overlaps. Userspace shall populate the @data_size field with
> > + * the effective size, in bytes, of the @data buffer.
> > + *
> > + * The expected memory layout of the parameters buffer is::
> > + *
> > + *	+-------------------- struct rkisp1_ext_params_cfg -------------------+
> > + *	| version = RKISP_EXT_PARAMS_BUFFER_V1;                               |
> > + *	| data_size = sizeof(struct rkisp1_ext_params_bls_config)             |
> > + *	|           + sizeof(struct rkisp1_ext_params_dpcc_config);           |
> > + *	| +------------------------- data  ---------------------------------+ |
> > + *	| | +------------- struct rkisp1_ext_params_bls_config -----------+ | |
> > + *	| | | +-------- struct rkisp1_ext_params_block_header  ---------+ | | |
> > + *	| | | | type = RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS;                | | | |
> > + *	| | | | enable = RKISP1_EXT_PARAMS_BLOCK_ENABLE;                | | | |
> > + *	| | | | size = sizeof(struct rkisp1_ext_params_bls_config);     | | | |
> > + *	| | | +---------------------------------------------------------+ | | |
> > + *	| | | +---------- struct rkisp1_cif_isp_bls_config -------------+ | | |
> > + *	| | | | enable_auto = 0;                                        | | | |
> > + *	| | | | fixed_val.r = 256;                                      | | | |
> > + *	| | | | fixed_val.gr = 256;                                     | | | |
> > + *	| | | | fixed_val.gb = 256;                                     | | | |
> > + *	| | | | fixed_val.b = 256;                                      | | | |
> > + *	| | | +---------------------------------------------------------+ | | |
> > + *	| | +------------ struct rkisp1_ext_params_dpcc_config -----------+ | |
> > + *	| | | +-------- struct rkisp1_ext_params_block_header  ---------+ | | |
> > + *	| | | | type = RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC;               | | | |
> > + *	| | | | enable = RKISP1_EXT_PARAMS_BLOCK_ENABLE;                | | | |
> > + *	| | | | size = sizeof(struct rkisp1_ext_params_dpcc_config);    | | | |
> > + *	| | | +---------------------------------------------------------+ | | |
> > + *	| | | +---------- struct rkisp1_cif_isp_dpcc_config ------------+ | | |
> > + *	| | | | mode = RKISP1_CIF_ISP_DPCC_MODE_STAGE1_ENABLE;          | | | |
> > + *	| | | | output_mode =                                           | | | |
> > + *	| | | |   RKISP1_CIF_ISP_DPCC_OUTPUT_MODE_STAGE1_INCL_G_CENTER; | | | |
> > + *	| | | | set_use = ... ;                                         | | | |
> > + *	| | | | ...  = ... ;                                            | | | |
> > + *	| | | +---------------------------------------------------------+ | | |
> > + *	| | +-------------------------------------------------------------+ | |
> > + *	| +-----------------------------------------------------------------+ |
> > + *	+---------------------------------------------------------------------+
> > + *
> > + * @version: The RkISP1 extensible parameters buffer version, see
> > + *	     :c:type:`rksip1_ext_param_buffer_version`
> > + * @data_size: The RkISP1 configuration data effective size, excluding this
> > + *	       header
> > + * @data: The RkISP1 extensible configuration data blocks
> > + */
> > +struct rkisp1_ext_params_cfg {
> > +	__u32 version;
> > +	__u32 data_size;
> > +	__u8 data[RKISP1_EXT_PARAMS_MAX_SIZE];
> > +};
> > +
> >  #endif /* _UAPI_RKISP1_CONFIG_H */

-- 
Regards,

Laurent Pinchart

Re: [PATCH v7 01/12] media: uapi: rkisp1-config: Add extensible params format

[Laurent Pinchart]

On Tue, Jul 30, 2024 at 02:14:08PM +0200, Hans Verkuil wrote:
> On 30/07/2024 14:11, Hans Verkuil wrote:
> > On 24/07/2024 10:49, Jacopo Mondi wrote:
> >> Add to the rkisp1-config.h header data types and documentation of
> >> the extensible parameters format.
> >>
> >> Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
> >> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> >> Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
> >> ---
> >>  include/uapi/linux/rkisp1-config.h | 489 +++++++++++++++++++++++++++++
> >>  1 file changed, 489 insertions(+)
> >>
> >> diff --git a/include/uapi/linux/rkisp1-config.h b/include/uapi/linux/rkisp1-config.h
> >> index 6eeaf8bf2362..00b09c92cca7 100644
> >> --- a/include/uapi/linux/rkisp1-config.h
> >> +++ b/include/uapi/linux/rkisp1-config.h
> >> @@ -996,4 +996,493 @@ struct rkisp1_stat_buffer {
> >>  	struct rkisp1_cif_isp_stat params;
> >>  };
> >>  
> >> +/*---------- PART3: Extensible Configuration Parameters  ------------*/
> >> +
> >> +/**
> >> + * enum rkisp1_ext_params_block_type - RkISP1 extensible params block type
> >> + *
> >> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS: Black level subtraction
> >> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC: Defect pixel cluster correction
> >> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG: Sensor de-gamma
> >> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN: Auto white balance gains
> >> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT: ISP filtering
> >> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM: Bayer de-mosaic
> >> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK: Cross-talk correction
> >> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC: Gamma out correction
> >> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF: De-noise pre-filter
> >> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH: De-noise pre-filter strength
> >> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC: Color processing
> >> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_IE: Image effects
> >> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC: Lens shading correction
> >> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS: Auto white balance statistics
> >> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS: Histogram statistics
> >> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS: Auto exposure statistics
> >> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS: Auto-focus statistics
> >> + */
> >> +enum rkisp1_ext_params_block_type {
> >> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS,
> >> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC,
> >> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG,
> >> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN,
> >> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT,
> >> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM,
> >> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK,
> >> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC,
> >> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF,
> >> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH,
> >> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC,
> >> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_IE,
> >> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC,
> >> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS,
> >> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS,
> >> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS,
> >> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS,
> >> +};
> >> +
> >> +/**
> >> + * enum rkisp1_ext_params_block_enable - RkISP1 extensible parameter block
> >> + *					 enable flags
> >> + *
> >> + * @RKISP1_EXT_PARAMS_BLOCK_DISABLE: Disable the HW block
> >> + * @RKISP1_EXT_PARAMS_BLOCK_ENABLE: Enable the HW block
> >> + */
> >> +enum rkisp1_ext_params_block_enable {
> >> +	RKISP1_EXT_PARAMS_BLOCK_DISABLE,
> >> +	RKISP1_EXT_PARAMS_BLOCK_ENABLE,
> >> +};
> >> +
> >> +/**
> >> + * struct rkisp1_ext_params_block_header - RkISP1 extensible parameter block
> >> + *					   header
> >> + *
> >> + * This structure represents the common part of all the ISP configuration
> >> + * blocks. Each parameters block shall embed an instance of this structure type
> >> + * as its first member, followed by the block-specific configuration data. The
> >> + * driver inspects this common header to discern the block type and its size and
> >> + * properly handle the block content by casting it to the correct block-specific
> >> + * type.
> >> + *
> >> + * The @type field is one of the values enumerated by
> >> + * :c:type:`rkisp1_ext_params_block_type` and specifies how the data should be
> >> + * interpreted by the driver. The @size field specifies the size of the
> >> + * parameters block and is used by the driver for validation purposes.
> >> + *
> >> + * The @enable field specifies the ISP block enablement state. The possible
> >> + * enablement states are enumerated by :c:type:`rkisp1_ext_params_block_enable`.
> >> + * When userspace needs to configure and enable an ISP block it shall fully
> >> + * populate the block configuration and the @enable flag shall be set to
> >> + * RKISP1_EXT_PARAMS_BLOCK_ENABLE. When userspace simply wants to disable the
> >> + * ISP block the @enable flag shall be set to RKISP1_EXT_PARAMS_BLOCK_DISABLE.
> >> + * The driver ignores the rest of the block configuration structure in this
> >> + * case.
> >> + *
> >> + * If a new configuration of an ISP block has to be applied userspace shall
> >> + * fully populate the ISP block configuration and set the @enable flag to
> >> + * RKISP1_EXT_PARAMS_BLOCK_ENABLE.
> >> + *
> >> + * Userspace is responsible for correctly populating the parameters block header
> >> + * fields (@type, @enable and @size) and the block-specific parameters.
> >> + *
> >> + * For example:
> >> + *
> >> + * .. code-block:: c
> >> + *
> >> + *	void populate_bls(struct rkisp1_ext_params_block_header *block) {
> >> + *		struct rkisp1_ext_params_bls_config *bls =
> >> + *			(struct rkisp1_ext_params_bls_config *)block;
> >> + *
> >> + *		bls->header.type = RKISP1_EXT_PARAMS_BLOCK_ID_BLS;
> >> + *		bls->header.enable = RKISP1_EXT_PARAMS_BLOCK_ENABLE;
> >> + *		bls->header.size = sizeof(*bls);
> >> + *
> >> + *		bls->config.enable_auto = 0;
> >> + *		bls->config.fixed_val.r = blackLevelRed_;
> >> + *		bls->config.fixed_val.gr = blackLevelGreenR_;
> >> + *		bls->config.fixed_val.gb = blackLevelGreenB_;
> >> + *		bls->config.fixed_val.b = blackLevelBlue_;
> >> + *	}
> >> + *
> >> + * @type: The parameters block type, see
> >> + *	  :c:type:`rkisp1_ext_params_block_type`
> >> + * @enable: The block enable flag, see
> >> + *	   :c:type:`rkisp1_ext_params_block_enable`
> >> + * @size: Size (in bytes) of the parameters block, including this header
> >> + */
> >> +struct rkisp1_ext_params_block_header {
> >> +	__u16 type;
> >> +	__u16 enable;
> >> +	__u16 size;
> > 
> > I would suggest changing this to '__u32 size;'. It ensures the header is8 bytes
> > long (much nicer than 6), and if there is ever a block > 65535, then it is supported.
> > 
> > i wonder if, with this change, the 'aligned(8)' attributes are even needed, but
> > I didn't dig into that.
> 
> Follow-up: I wonder if this can be a generic v4l2 struct: perhaps the same approach
> makes sense for other drivers as well.
> 
> Just an idea.

Probably, but I'd wait until we have a couple of drivers using the same
design before standardizing something.

> > Did you check with pahole for holes etc. in the datastructures?
> > 
> >> +} __attribute__((aligned(8)));
> >> +
> >> +/**
> >> + * struct rkisp1_ext_params_bls_config - RkISP1 extensible params BLS config
> >> + *
> >> + * RkISP1 extensible parameters Black Level Subtraction configuration block.
> >> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS`.
> >> + *
> >> + * @header: The RkISP1 extensible parameters header, see
> >> + *	    :c:type:`rkisp1_ext_params_block_header`
> >> + * @config: Black Level Subtraction configuration, see
> >> + *	    :c:type:`rkisp1_cif_isp_bls_config`
> >> + */
> >> +struct rkisp1_ext_params_bls_config {
> >> +	struct rkisp1_ext_params_block_header header;
> >> +	struct rkisp1_cif_isp_bls_config config;
> >> +} __attribute__((aligned(8)));
> >> +
> >> +/**
> >> + * struct rkisp1_ext_params_dpcc_config - RkISP1 extensible params DPCC config
> >> + *
> >> + * RkISP1 extensible parameters Defective Pixel Cluster Correction configuration
> >> + * block. Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC`.
> >> + *
> >> + * @header: The RkISP1 extensible parameters header, see
> >> + *	    :c:type:`rkisp1_ext_params_block_header`
> >> + * @config: Defective Pixel Cluster Correction configuration, see
> >> + *	    :c:type:`rkisp1_cif_isp_dpcc_config`
> >> + */
> >> +struct rkisp1_ext_params_dpcc_config {
> >> +	struct rkisp1_ext_params_block_header header;
> >> +	struct rkisp1_cif_isp_dpcc_config config;
> >> +} __attribute__((aligned(8)));
> >> +
> >> +/**
> >> + * struct rkisp1_ext_params_sdg_config - RkISP1 extensible params SDG config
> >> + *
> >> + * RkISP1 extensible parameters Sensor Degamma configuration block. Identified
> >> + * by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG`.
> >> + *
> >> + * @header: The RkISP1 extensible parameters header, see
> >> + *	    :c:type:`rkisp1_ext_params_block_header`
> >> + * @config: Sensor Degamma configuration, see
> >> + *	    :c:type:`rkisp1_cif_isp_sdg_config`
> >> + */
> >> +struct rkisp1_ext_params_sdg_config {
> >> +	struct rkisp1_ext_params_block_header header;
> >> +	struct rkisp1_cif_isp_sdg_config config;
> >> +} __attribute__((aligned(8)));
> >> +
> >> +/**
> >> + * struct rkisp1_ext_params_lsc_config - RkISP1 extensible params LSC config
> >> + *
> >> + * RkISP1 extensible parameters Lens Shading Correction configuration block.
> >> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC`.
> >> + *
> >> + * @header: The RkISP1 extensible parameters header, see
> >> + *	    :c:type:`rkisp1_ext_params_block_header`
> >> + * @config: Lens Shading Correction configuration, see
> >> + *	    :c:type:`rkisp1_cif_isp_lsc_config`
> >> + */
> >> +struct rkisp1_ext_params_lsc_config {
> >> +	struct rkisp1_ext_params_block_header header;
> >> +	struct rkisp1_cif_isp_lsc_config config;
> >> +} __attribute__((aligned(8)));
> >> +
> >> +/**
> >> + * struct rkisp1_ext_params_awb_gain_config - RkISP1 extensible params AWB
> >> + *					      gain config
> >> + *
> >> + * RkISP1 extensible parameters Auto-White Balance Gains configuration block.
> >> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN`.
> >> + *
> >> + * @header: The RkISP1 extensible parameters header, see
> >> + *	    :c:type:`rkisp1_ext_params_block_header`
> >> + * @config: Auto-White Balance Gains configuration, see
> >> + *	    :c:type:`rkisp1_cif_isp_awb_gain_config`
> >> + */
> >> +struct rkisp1_ext_params_awb_gain_config {
> >> +	struct rkisp1_ext_params_block_header header;
> >> +	struct rkisp1_cif_isp_awb_gain_config config;
> >> +} __attribute__((aligned(8)));
> >> +
> >> +/**
> >> + * struct rkisp1_ext_params_flt_config - RkISP1 extensible params FLT config
> >> + *
> >> + * RkISP1 extensible parameters Filter configuration block. Identified by
> >> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT`.
> >> + *
> >> + * @header: The RkISP1 extensible parameters header, see
> >> + *	    :c:type:`rkisp1_ext_params_block_header`
> >> + * @config: Filter configuration, see :c:type:`rkisp1_cif_isp_flt_config`
> >> + */
> >> +struct rkisp1_ext_params_flt_config {
> >> +	struct rkisp1_ext_params_block_header header;
> >> +	struct rkisp1_cif_isp_flt_config config;
> >> +} __attribute__((aligned(8)));
> >> +
> >> +/**
> >> + * struct rkisp1_ext_params_bdm_config - RkISP1 extensible params BDM config
> >> + *
> >> + * RkISP1 extensible parameters Demosaicing configuration block. Identified by
> >> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM`.
> >> + *
> >> + * @header: The RkISP1 extensible parameters header, see
> >> + *	    :c:type:`rkisp1_ext_params_block_header`
> >> + * @config: Demosaicing configuration, see :c:type:`rkisp1_cif_isp_bdm_config`
> >> + */
> >> +struct rkisp1_ext_params_bdm_config {
> >> +	struct rkisp1_ext_params_block_header header;
> >> +	struct rkisp1_cif_isp_bdm_config config;
> >> +} __attribute__((aligned(8)));
> >> +
> >> +/**
> >> + * struct rkisp1_ext_params_ctk_config - RkISP1 extensible params CTK config
> >> + *
> >> + * RkISP1 extensible parameters Cross-Talk configuration block. Identified by
> >> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK`.
> >> + *
> >> + * @header: The RkISP1 extensible parameters header, see
> >> + *	    :c:type:`rkisp1_ext_params_block_header`
> >> + * @config: Cross-Talk configuration, see :c:type:`rkisp1_cif_isp_ctk_config`
> >> + */
> >> +struct rkisp1_ext_params_ctk_config {
> >> +	struct rkisp1_ext_params_block_header header;
> >> +	struct rkisp1_cif_isp_ctk_config config;
> >> +} __attribute__((aligned(8)));
> >> +
> >> +/**
> >> + * struct rkisp1_ext_params_goc_config - RkISP1 extensible params GOC config
> >> + *
> >> + * RkISP1 extensible parameters Gamma-Out configuration block. Identified by
> >> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC`.
> >> + *
> >> + * @header: The RkISP1 extensible parameters header, see
> >> + *	    :c:type:`rkisp1_ext_params_block_header`
> >> + * @config: Gamma-Out configuration, see :c:type:`rkisp1_cif_isp_goc_config`
> >> + */
> >> +struct rkisp1_ext_params_goc_config {
> >> +	struct rkisp1_ext_params_block_header header;
> >> +	struct rkisp1_cif_isp_goc_config config;
> >> +} __attribute__((aligned(8)));
> >> +
> >> +/**
> >> + * struct rkisp1_ext_params_dpf_config - RkISP1 extensible params DPF config
> >> + *
> >> + * RkISP1 extensible parameters De-noise Pre-Filter configuration block.
> >> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF`.
> >> + *
> >> + * @header: The RkISP1 extensible parameters header, see
> >> + *	    :c:type:`rkisp1_ext_params_block_header`
> >> + * @config: De-noise Pre-Filter configuration, see
> >> + *	    :c:type:`rkisp1_cif_isp_dpf_config`
> >> + */
> >> +struct rkisp1_ext_params_dpf_config {
> >> +	struct rkisp1_ext_params_block_header header;
> >> +	struct rkisp1_cif_isp_dpf_config config;
> >> +} __attribute__((aligned(8)));
> >> +
> >> +/**
> >> + * struct rkisp1_ext_params_dpf_strength_config - RkISP1 extensible params DPF
> >> + *						  strength config
> >> + *
> >> + * RkISP1 extensible parameters De-noise Pre-Filter strength configuration
> >> + * block. Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH`.
> >> + *
> >> + * @header: The RkISP1 extensible parameters header, see
> >> + *	    :c:type:`rkisp1_ext_params_block_header`
> >> + * @config: De-noise Pre-Filter strength configuration, see
> >> + *	    :c:type:`rkisp1_cif_isp_dpf_strength_config`
> >> + */
> >> +struct rkisp1_ext_params_dpf_strength_config {
> >> +	struct rkisp1_ext_params_block_header header;
> >> +	struct rkisp1_cif_isp_dpf_strength_config config;
> >> +} __attribute__((aligned(8)));
> >> +
> >> +/**
> >> + * struct rkisp1_ext_params_cproc_config - RkISP1 extensible params CPROC config
> >> + *
> >> + * RkISP1 extensible parameters Color Processing configuration block.
> >> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC`.
> >> + *
> >> + * @header: The RkISP1 extensible parameters header, see
> >> + *	    :c:type:`rkisp1_ext_params_block_header`
> >> + * @config: Color processing configuration, see
> >> + *	    :c:type:`rkisp1_cif_isp_cproc_config`
> >> + */
> >> +struct rkisp1_ext_params_cproc_config {
> >> +	struct rkisp1_ext_params_block_header header;
> >> +	struct rkisp1_cif_isp_cproc_config config;
> >> +} __attribute__((aligned(8)));
> >> +
> >> +/**
> >> + * struct rkisp1_ext_params_ie_config - RkISP1 extensible params IE config
> >> + *
> >> + * RkISP1 extensible parameters Image Effect configuration block. Identified by
> >> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_IE`.
> >> + *
> >> + * @header: The RkISP1 extensible parameters header, see
> >> + *	    :c:type:`rkisp1_ext_params_block_header`
> >> + * @config: Image Effect configuration, see :c:type:`rkisp1_cif_isp_ie_config`
> >> + */
> >> +struct rkisp1_ext_params_ie_config {
> >> +	struct rkisp1_ext_params_block_header header;
> >> +	struct rkisp1_cif_isp_ie_config config;
> >> +} __attribute__((aligned(8)));
> >> +
> >> +/**
> >> + * struct rkisp1_ext_params_awb_meas_config - RkISP1 extensible params AWB
> >> + *					      Meas config
> >> + *
> >> + * RkISP1 extensible parameters Auto-White Balance Measurement configuration
> >> + * block. Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS`.
> >> + *
> >> + * @header: The RkISP1 extensible parameters header, see
> >> + *	    :c:type:`rkisp1_ext_params_block_header`
> >> + * @config: Auto-White Balance measure configuration, see
> >> + *	    :c:type:`rkisp1_cif_isp_awb_meas_config`
> >> + */
> >> +struct rkisp1_ext_params_awb_meas_config {
> >> +	struct rkisp1_ext_params_block_header header;
> >> +	struct rkisp1_cif_isp_awb_meas_config config;
> >> +} __attribute__((aligned(8)));
> >> +
> >> +/**
> >> + * struct rkisp1_ext_params_hst_config - RkISP1 extensible params Histogram config
> >> + *
> >> + * RkISP1 extensible parameters Histogram statistics configuration block.
> >> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS`.
> >> + *
> >> + * @header: The RkISP1 extensible parameters header, see
> >> + *	    :c:type:`rkisp1_ext_params_block_header`
> >> + * @config: Histogram statistics configuration, see
> >> + *	    :c:type:`rkisp1_cif_isp_hst_config`
> >> + */
> >> +struct rkisp1_ext_params_hst_config {
> >> +	struct rkisp1_ext_params_block_header header;
> >> +	struct rkisp1_cif_isp_hst_config config;
> >> +} __attribute__((aligned(8)));
> >> +
> >> +/**
> >> + * struct rkisp1_ext_params_aec_config - RkISP1 extensible params AEC config
> >> + *
> >> + * RkISP1 extensible parameters Auto-Exposure statistics configuration block.
> >> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS`.
> >> + *
> >> + * @header: The RkISP1 extensible parameters header, see
> >> + *	    :c:type:`rkisp1_ext_params_block_header`
> >> + * @config: Auto-Exposure statistics configuration, see
> >> + *	    :c:type:`rkisp1_cif_isp_aec_config`
> >> + */
> >> +struct rkisp1_ext_params_aec_config {
> >> +	struct rkisp1_ext_params_block_header header;
> >> +	struct rkisp1_cif_isp_aec_config config;
> >> +} __attribute__((aligned(8)));
> >> +
> >> +/**
> >> + * struct rkisp1_ext_params_afc_config - RkISP1 extensible params AFC config
> >> + *
> >> + * RkISP1 extensible parameters Auto-Focus statistics configuration block.
> >> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS`.
> >> + *
> >> + * @header: The RkISP1 extensible parameters header, see
> >> + *	    :c:type:`rkisp1_ext_params_block_header`
> >> + * @config: Auto-Focus statistics configuration, see
> >> + *	    :c:type:`rkisp1_cif_isp_afc_config`
> >> + */
> >> +struct rkisp1_ext_params_afc_config {
> >> +	struct rkisp1_ext_params_block_header header;
> >> +	struct rkisp1_cif_isp_afc_config config;
> >> +} __attribute__((aligned(8)));
> >> +
> >> +#define RKISP1_EXT_PARAMS_MAX_SIZE					\
> >> +	(sizeof(struct rkisp1_ext_params_bls_config)			+\
> >> +	sizeof(struct rkisp1_ext_params_dpcc_config)			+\
> >> +	sizeof(struct rkisp1_ext_params_sdg_config)			+\
> >> +	sizeof(struct rkisp1_ext_params_lsc_config)			+\
> >> +	sizeof(struct rkisp1_ext_params_awb_gain_config)		+\
> >> +	sizeof(struct rkisp1_ext_params_flt_config)			+\
> >> +	sizeof(struct rkisp1_ext_params_bdm_config)			+\
> >> +	sizeof(struct rkisp1_ext_params_ctk_config)			+\
> >> +	sizeof(struct rkisp1_ext_params_goc_config)			+\
> >> +	sizeof(struct rkisp1_ext_params_dpf_config)			+\
> >> +	sizeof(struct rkisp1_ext_params_dpf_strength_config)		+\
> >> +	sizeof(struct rkisp1_ext_params_cproc_config)			+\
> >> +	sizeof(struct rkisp1_ext_params_ie_config)			+\
> >> +	sizeof(struct rkisp1_ext_params_awb_meas_config)		+\
> >> +	sizeof(struct rkisp1_ext_params_hst_config)			+\
> >> +	sizeof(struct rkisp1_ext_params_aec_config)			+\
> >> +	sizeof(struct rkisp1_ext_params_afc_config))
> >> +
> >> +/**
> >> + * enum rksip1_ext_param_buffer_version - RkISP1 extensible parameters version
> >> + *
> >> + * @RKISP1_EXT_PARAM_BUFFER_V1: First version of RkISP1 extensible parameters
> >> + */
> >> +enum rksip1_ext_param_buffer_version {
> >> +	RKISP1_EXT_PARAM_BUFFER_V1 = 1,
> >> +};
> >> +
> >> +/**
> >> + * struct rkisp1_ext_params_cfg - RkISP1 extensible parameters configuration
> >> + *
> >> + * This struct contains the configuration parameters of the RkISP1 ISP
> >> + * algorithms, serialized by userspace into a data buffer. Each configuration
> >> + * parameter block is represented by a block-specific structure which contains a
> >> + * :c:type:`rkisp1_ext_params_block_header` entry as first member. Userspace
> >> + * populates the @data buffer with configuration parameters for the blocks that
> >> + * it intends to configure. As a consequence, the data buffer effective size
> >> + * changes according to the number of ISP blocks that userspace intends to
> >> + * configure and is set by userspace in the @data_size field.
> >> + *
> >> + * The parameters buffer is versioned by the @version field to allow modifying
> >> + * and extending its definition. Userspace shall populate the @version field to
> >> + * inform the driver about the version it intends to use. The driver will parse
> >> + * and handle the @data buffer according to the data layout specific to the
> >> + * indicated version and return an error if the desired version is not
> >> + * supported.
> >> + *
> >> + * For each ISP block that userspace wants to configure, a block-specific
> >> + * structure is appended to the @data buffer, one after the other without gaps
> >> + * in between nor overlaps. Userspace shall populate the @data_size field with
> >> + * the effective size, in bytes, of the @data buffer.
> >> + *
> >> + * The expected memory layout of the parameters buffer is::
> >> + *
> >> + *	+-------------------- struct rkisp1_ext_params_cfg -------------------+
> >> + *	| version = RKISP_EXT_PARAMS_BUFFER_V1;                               |
> >> + *	| data_size = sizeof(struct rkisp1_ext_params_bls_config)             |
> >> + *	|           + sizeof(struct rkisp1_ext_params_dpcc_config);           |
> >> + *	| +------------------------- data  ---------------------------------+ |
> >> + *	| | +------------- struct rkisp1_ext_params_bls_config -----------+ | |
> >> + *	| | | +-------- struct rkisp1_ext_params_block_header  ---------+ | | |
> >> + *	| | | | type = RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS;                | | | |
> >> + *	| | | | enable = RKISP1_EXT_PARAMS_BLOCK_ENABLE;                | | | |
> >> + *	| | | | size = sizeof(struct rkisp1_ext_params_bls_config);     | | | |
> >> + *	| | | +---------------------------------------------------------+ | | |
> >> + *	| | | +---------- struct rkisp1_cif_isp_bls_config -------------+ | | |
> >> + *	| | | | enable_auto = 0;                                        | | | |
> >> + *	| | | | fixed_val.r = 256;                                      | | | |
> >> + *	| | | | fixed_val.gr = 256;                                     | | | |
> >> + *	| | | | fixed_val.gb = 256;                                     | | | |
> >> + *	| | | | fixed_val.b = 256;                                      | | | |
> >> + *	| | | +---------------------------------------------------------+ | | |
> >> + *	| | +------------ struct rkisp1_ext_params_dpcc_config -----------+ | |
> >> + *	| | | +-------- struct rkisp1_ext_params_block_header  ---------+ | | |
> >> + *	| | | | type = RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC;               | | | |
> >> + *	| | | | enable = RKISP1_EXT_PARAMS_BLOCK_ENABLE;                | | | |
> >> + *	| | | | size = sizeof(struct rkisp1_ext_params_dpcc_config);    | | | |
> >> + *	| | | +---------------------------------------------------------+ | | |
> >> + *	| | | +---------- struct rkisp1_cif_isp_dpcc_config ------------+ | | |
> >> + *	| | | | mode = RKISP1_CIF_ISP_DPCC_MODE_STAGE1_ENABLE;          | | | |
> >> + *	| | | | output_mode =                                           | | | |
> >> + *	| | | |   RKISP1_CIF_ISP_DPCC_OUTPUT_MODE_STAGE1_INCL_G_CENTER; | | | |
> >> + *	| | | | set_use = ... ;                                         | | | |
> >> + *	| | | | ...  = ... ;                                            | | | |
> >> + *	| | | +---------------------------------------------------------+ | | |
> >> + *	| | +-------------------------------------------------------------+ | |
> >> + *	| +-----------------------------------------------------------------+ |
> >> + *	+---------------------------------------------------------------------+
> >> + *
> >> + * @version: The RkISP1 extensible parameters buffer version, see
> >> + *	     :c:type:`rksip1_ext_param_buffer_version`
> >> + * @data_size: The RkISP1 configuration data effective size, excluding this
> >> + *	       header
> >> + * @data: The RkISP1 extensible configuration data blocks
> >> + */
> >> +struct rkisp1_ext_params_cfg {
> >> +	__u32 version;
> >> +	__u32 data_size;
> >> +	__u8 data[RKISP1_EXT_PARAMS_MAX_SIZE];
> >> +};
> >> +
> >>  #endif /* _UAPI_RKISP1_CONFIG_H */

-- 
Regards,

Laurent Pinchart

Re: [PATCH v7 01/12] media: uapi: rkisp1-config: Add extensible params format

[Hans Verkuil]

On 30/07/2024 14:18, Laurent Pinchart wrote:
> Hi Hans,
> 
> On Tue, Jul 30, 2024 at 02:11:12PM +0200, Hans Verkuil wrote:
>> On 24/07/2024 10:49, Jacopo Mondi wrote:
>>> Add to the rkisp1-config.h header data types and documentation of
>>> the extensible parameters format.
>>>
>>> Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
>>> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
>>> Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
>>> ---
>>>  include/uapi/linux/rkisp1-config.h | 489 +++++++++++++++++++++++++++++
>>>  1 file changed, 489 insertions(+)
>>>
>>> diff --git a/include/uapi/linux/rkisp1-config.h b/include/uapi/linux/rkisp1-config.h
>>> index 6eeaf8bf2362..00b09c92cca7 100644
>>> --- a/include/uapi/linux/rkisp1-config.h
>>> +++ b/include/uapi/linux/rkisp1-config.h
>>> @@ -996,4 +996,493 @@ struct rkisp1_stat_buffer {
>>>  	struct rkisp1_cif_isp_stat params;
>>>  };
>>>  
>>> +/*---------- PART3: Extensible Configuration Parameters  ------------*/
>>> +
>>> +/**
>>> + * enum rkisp1_ext_params_block_type - RkISP1 extensible params block type
>>> + *
>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS: Black level subtraction
>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC: Defect pixel cluster correction
>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG: Sensor de-gamma
>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN: Auto white balance gains
>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT: ISP filtering
>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM: Bayer de-mosaic
>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK: Cross-talk correction
>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC: Gamma out correction
>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF: De-noise pre-filter
>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH: De-noise pre-filter strength
>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC: Color processing
>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_IE: Image effects
>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC: Lens shading correction
>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS: Auto white balance statistics
>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS: Histogram statistics
>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS: Auto exposure statistics
>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS: Auto-focus statistics
>>> + */
>>> +enum rkisp1_ext_params_block_type {
>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS,
>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC,
>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG,
>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN,
>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT,
>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM,
>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK,
>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC,
>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF,
>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH,
>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC,
>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_IE,
>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC,
>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS,
>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS,
>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS,
>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS,
>>> +};
>>> +
>>> +/**
>>> + * enum rkisp1_ext_params_block_enable - RkISP1 extensible parameter block
>>> + *					 enable flags
>>> + *
>>> + * @RKISP1_EXT_PARAMS_BLOCK_DISABLE: Disable the HW block
>>> + * @RKISP1_EXT_PARAMS_BLOCK_ENABLE: Enable the HW block
>>> + */
>>> +enum rkisp1_ext_params_block_enable {
>>> +	RKISP1_EXT_PARAMS_BLOCK_DISABLE,
>>> +	RKISP1_EXT_PARAMS_BLOCK_ENABLE,
>>> +};
>>> +
>>> +/**
>>> + * struct rkisp1_ext_params_block_header - RkISP1 extensible parameter block
>>> + *					   header
>>> + *
>>> + * This structure represents the common part of all the ISP configuration
>>> + * blocks. Each parameters block shall embed an instance of this structure type
>>> + * as its first member, followed by the block-specific configuration data. The
>>> + * driver inspects this common header to discern the block type and its size and
>>> + * properly handle the block content by casting it to the correct block-specific
>>> + * type.
>>> + *
>>> + * The @type field is one of the values enumerated by
>>> + * :c:type:`rkisp1_ext_params_block_type` and specifies how the data should be
>>> + * interpreted by the driver. The @size field specifies the size of the
>>> + * parameters block and is used by the driver for validation purposes.
>>> + *
>>> + * The @enable field specifies the ISP block enablement state. The possible
>>> + * enablement states are enumerated by :c:type:`rkisp1_ext_params_block_enable`.
>>> + * When userspace needs to configure and enable an ISP block it shall fully
>>> + * populate the block configuration and the @enable flag shall be set to
>>> + * RKISP1_EXT_PARAMS_BLOCK_ENABLE. When userspace simply wants to disable the
>>> + * ISP block the @enable flag shall be set to RKISP1_EXT_PARAMS_BLOCK_DISABLE.
>>> + * The driver ignores the rest of the block configuration structure in this
>>> + * case.
>>> + *
>>> + * If a new configuration of an ISP block has to be applied userspace shall
>>> + * fully populate the ISP block configuration and set the @enable flag to
>>> + * RKISP1_EXT_PARAMS_BLOCK_ENABLE.
>>> + *
>>> + * Userspace is responsible for correctly populating the parameters block header
>>> + * fields (@type, @enable and @size) and the block-specific parameters.
>>> + *
>>> + * For example:
>>> + *
>>> + * .. code-block:: c
>>> + *
>>> + *	void populate_bls(struct rkisp1_ext_params_block_header *block) {
>>> + *		struct rkisp1_ext_params_bls_config *bls =
>>> + *			(struct rkisp1_ext_params_bls_config *)block;
>>> + *
>>> + *		bls->header.type = RKISP1_EXT_PARAMS_BLOCK_ID_BLS;
>>> + *		bls->header.enable = RKISP1_EXT_PARAMS_BLOCK_ENABLE;
>>> + *		bls->header.size = sizeof(*bls);
>>> + *
>>> + *		bls->config.enable_auto = 0;
>>> + *		bls->config.fixed_val.r = blackLevelRed_;
>>> + *		bls->config.fixed_val.gr = blackLevelGreenR_;
>>> + *		bls->config.fixed_val.gb = blackLevelGreenB_;
>>> + *		bls->config.fixed_val.b = blackLevelBlue_;
>>> + *	}
>>> + *
>>> + * @type: The parameters block type, see
>>> + *	  :c:type:`rkisp1_ext_params_block_type`
>>> + * @enable: The block enable flag, see
>>> + *	   :c:type:`rkisp1_ext_params_block_enable`
>>> + * @size: Size (in bytes) of the parameters block, including this header
>>> + */
>>> +struct rkisp1_ext_params_block_header {
>>> +	__u16 type;
>>> +	__u16 enable;
>>> +	__u16 size;
>>
>> I would suggest changing this to '__u32 size;'. It ensures the header is8 bytes
>> long (much nicer than 6), and if there is ever a block > 65535, then it is supported.
> 
> I'm pretty confident we will never need a block size larger than 64kB.

Hmm, famous last words :-)

> That would mean more than 64kB of data written to hardware
> registers/SRAM for a single processing block, and it would be incredibly
> expensive in terms of hardware. Keeping size a __u16 means we have two
> bytes of reserved space we could possibly use later, which may come
> handy.

i would prefer to change the size to a u32, but rename the 'enable' field
to 'flags', and assign bit 0 to the enable/disable bit. This is a bit
more flexible IMHO and allows for 15 bits to encode additional data.

 Blocks > 64kB could still be supported in the future by defining
> a new version of the parameters format (RKISP1_EXT_PARAM_BUFFER_V2)
> without needing a different 4CC.
> 
> This being said, the opposite argument can be made, that a 32-bit size
> could come handy if we ever have larger blocks, and a new version of the
> parameters format could be used if we ever need to add more fields to
> the block header. I won't insist either way.
> 
>> i wonder if, with this change, the 'aligned(8)' attributes are even needed, but
>> I didn't dig into that.
> 
> The header would become 8-bytes long, but its larger field would still
> be 4-bytes long, so the compiler would only enforce 4-bytes aligned
> AFAIK.

Normally the actual data blocks (in the non-extensible format) are already aligned
to either 4 or 8 bytes (depending on whether u64 values are used). So an 8 byte
header won't mess up the alignment.

Regards,

	Hans

> 
>> Did you check with pahole for holes etc. in the datastructures?
> 
> That's a good idea in any case.
> 
>>> +} __attribute__((aligned(8)));
>>> +
>>> +/**
>>> + * struct rkisp1_ext_params_bls_config - RkISP1 extensible params BLS config
>>> + *
>>> + * RkISP1 extensible parameters Black Level Subtraction configuration block.
>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS`.
>>> + *
>>> + * @header: The RkISP1 extensible parameters header, see
>>> + *	    :c:type:`rkisp1_ext_params_block_header`
>>> + * @config: Black Level Subtraction configuration, see
>>> + *	    :c:type:`rkisp1_cif_isp_bls_config`
>>> + */
>>> +struct rkisp1_ext_params_bls_config {
>>> +	struct rkisp1_ext_params_block_header header;
>>> +	struct rkisp1_cif_isp_bls_config config;
>>> +} __attribute__((aligned(8)));
>>> +
>>> +/**
>>> + * struct rkisp1_ext_params_dpcc_config - RkISP1 extensible params DPCC config
>>> + *
>>> + * RkISP1 extensible parameters Defective Pixel Cluster Correction configuration
>>> + * block. Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC`.
>>> + *
>>> + * @header: The RkISP1 extensible parameters header, see
>>> + *	    :c:type:`rkisp1_ext_params_block_header`
>>> + * @config: Defective Pixel Cluster Correction configuration, see
>>> + *	    :c:type:`rkisp1_cif_isp_dpcc_config`
>>> + */
>>> +struct rkisp1_ext_params_dpcc_config {
>>> +	struct rkisp1_ext_params_block_header header;
>>> +	struct rkisp1_cif_isp_dpcc_config config;
>>> +} __attribute__((aligned(8)));
>>> +
>>> +/**
>>> + * struct rkisp1_ext_params_sdg_config - RkISP1 extensible params SDG config
>>> + *
>>> + * RkISP1 extensible parameters Sensor Degamma configuration block. Identified
>>> + * by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG`.
>>> + *
>>> + * @header: The RkISP1 extensible parameters header, see
>>> + *	    :c:type:`rkisp1_ext_params_block_header`
>>> + * @config: Sensor Degamma configuration, see
>>> + *	    :c:type:`rkisp1_cif_isp_sdg_config`
>>> + */
>>> +struct rkisp1_ext_params_sdg_config {
>>> +	struct rkisp1_ext_params_block_header header;
>>> +	struct rkisp1_cif_isp_sdg_config config;
>>> +} __attribute__((aligned(8)));
>>> +
>>> +/**
>>> + * struct rkisp1_ext_params_lsc_config - RkISP1 extensible params LSC config
>>> + *
>>> + * RkISP1 extensible parameters Lens Shading Correction configuration block.
>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC`.
>>> + *
>>> + * @header: The RkISP1 extensible parameters header, see
>>> + *	    :c:type:`rkisp1_ext_params_block_header`
>>> + * @config: Lens Shading Correction configuration, see
>>> + *	    :c:type:`rkisp1_cif_isp_lsc_config`
>>> + */
>>> +struct rkisp1_ext_params_lsc_config {
>>> +	struct rkisp1_ext_params_block_header header;
>>> +	struct rkisp1_cif_isp_lsc_config config;
>>> +} __attribute__((aligned(8)));
>>> +
>>> +/**
>>> + * struct rkisp1_ext_params_awb_gain_config - RkISP1 extensible params AWB
>>> + *					      gain config
>>> + *
>>> + * RkISP1 extensible parameters Auto-White Balance Gains configuration block.
>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN`.
>>> + *
>>> + * @header: The RkISP1 extensible parameters header, see
>>> + *	    :c:type:`rkisp1_ext_params_block_header`
>>> + * @config: Auto-White Balance Gains configuration, see
>>> + *	    :c:type:`rkisp1_cif_isp_awb_gain_config`
>>> + */
>>> +struct rkisp1_ext_params_awb_gain_config {
>>> +	struct rkisp1_ext_params_block_header header;
>>> +	struct rkisp1_cif_isp_awb_gain_config config;
>>> +} __attribute__((aligned(8)));
>>> +
>>> +/**
>>> + * struct rkisp1_ext_params_flt_config - RkISP1 extensible params FLT config
>>> + *
>>> + * RkISP1 extensible parameters Filter configuration block. Identified by
>>> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT`.
>>> + *
>>> + * @header: The RkISP1 extensible parameters header, see
>>> + *	    :c:type:`rkisp1_ext_params_block_header`
>>> + * @config: Filter configuration, see :c:type:`rkisp1_cif_isp_flt_config`
>>> + */
>>> +struct rkisp1_ext_params_flt_config {
>>> +	struct rkisp1_ext_params_block_header header;
>>> +	struct rkisp1_cif_isp_flt_config config;
>>> +} __attribute__((aligned(8)));
>>> +
>>> +/**
>>> + * struct rkisp1_ext_params_bdm_config - RkISP1 extensible params BDM config
>>> + *
>>> + * RkISP1 extensible parameters Demosaicing configuration block. Identified by
>>> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM`.
>>> + *
>>> + * @header: The RkISP1 extensible parameters header, see
>>> + *	    :c:type:`rkisp1_ext_params_block_header`
>>> + * @config: Demosaicing configuration, see :c:type:`rkisp1_cif_isp_bdm_config`
>>> + */
>>> +struct rkisp1_ext_params_bdm_config {
>>> +	struct rkisp1_ext_params_block_header header;
>>> +	struct rkisp1_cif_isp_bdm_config config;
>>> +} __attribute__((aligned(8)));
>>> +
>>> +/**
>>> + * struct rkisp1_ext_params_ctk_config - RkISP1 extensible params CTK config
>>> + *
>>> + * RkISP1 extensible parameters Cross-Talk configuration block. Identified by
>>> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK`.
>>> + *
>>> + * @header: The RkISP1 extensible parameters header, see
>>> + *	    :c:type:`rkisp1_ext_params_block_header`
>>> + * @config: Cross-Talk configuration, see :c:type:`rkisp1_cif_isp_ctk_config`
>>> + */
>>> +struct rkisp1_ext_params_ctk_config {
>>> +	struct rkisp1_ext_params_block_header header;
>>> +	struct rkisp1_cif_isp_ctk_config config;
>>> +} __attribute__((aligned(8)));
>>> +
>>> +/**
>>> + * struct rkisp1_ext_params_goc_config - RkISP1 extensible params GOC config
>>> + *
>>> + * RkISP1 extensible parameters Gamma-Out configuration block. Identified by
>>> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC`.
>>> + *
>>> + * @header: The RkISP1 extensible parameters header, see
>>> + *	    :c:type:`rkisp1_ext_params_block_header`
>>> + * @config: Gamma-Out configuration, see :c:type:`rkisp1_cif_isp_goc_config`
>>> + */
>>> +struct rkisp1_ext_params_goc_config {
>>> +	struct rkisp1_ext_params_block_header header;
>>> +	struct rkisp1_cif_isp_goc_config config;
>>> +} __attribute__((aligned(8)));
>>> +
>>> +/**
>>> + * struct rkisp1_ext_params_dpf_config - RkISP1 extensible params DPF config
>>> + *
>>> + * RkISP1 extensible parameters De-noise Pre-Filter configuration block.
>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF`.
>>> + *
>>> + * @header: The RkISP1 extensible parameters header, see
>>> + *	    :c:type:`rkisp1_ext_params_block_header`
>>> + * @config: De-noise Pre-Filter configuration, see
>>> + *	    :c:type:`rkisp1_cif_isp_dpf_config`
>>> + */
>>> +struct rkisp1_ext_params_dpf_config {
>>> +	struct rkisp1_ext_params_block_header header;
>>> +	struct rkisp1_cif_isp_dpf_config config;
>>> +} __attribute__((aligned(8)));
>>> +
>>> +/**
>>> + * struct rkisp1_ext_params_dpf_strength_config - RkISP1 extensible params DPF
>>> + *						  strength config
>>> + *
>>> + * RkISP1 extensible parameters De-noise Pre-Filter strength configuration
>>> + * block. Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH`.
>>> + *
>>> + * @header: The RkISP1 extensible parameters header, see
>>> + *	    :c:type:`rkisp1_ext_params_block_header`
>>> + * @config: De-noise Pre-Filter strength configuration, see
>>> + *	    :c:type:`rkisp1_cif_isp_dpf_strength_config`
>>> + */
>>> +struct rkisp1_ext_params_dpf_strength_config {
>>> +	struct rkisp1_ext_params_block_header header;
>>> +	struct rkisp1_cif_isp_dpf_strength_config config;
>>> +} __attribute__((aligned(8)));
>>> +
>>> +/**
>>> + * struct rkisp1_ext_params_cproc_config - RkISP1 extensible params CPROC config
>>> + *
>>> + * RkISP1 extensible parameters Color Processing configuration block.
>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC`.
>>> + *
>>> + * @header: The RkISP1 extensible parameters header, see
>>> + *	    :c:type:`rkisp1_ext_params_block_header`
>>> + * @config: Color processing configuration, see
>>> + *	    :c:type:`rkisp1_cif_isp_cproc_config`
>>> + */
>>> +struct rkisp1_ext_params_cproc_config {
>>> +	struct rkisp1_ext_params_block_header header;
>>> +	struct rkisp1_cif_isp_cproc_config config;
>>> +} __attribute__((aligned(8)));
>>> +
>>> +/**
>>> + * struct rkisp1_ext_params_ie_config - RkISP1 extensible params IE config
>>> + *
>>> + * RkISP1 extensible parameters Image Effect configuration block. Identified by
>>> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_IE`.
>>> + *
>>> + * @header: The RkISP1 extensible parameters header, see
>>> + *	    :c:type:`rkisp1_ext_params_block_header`
>>> + * @config: Image Effect configuration, see :c:type:`rkisp1_cif_isp_ie_config`
>>> + */
>>> +struct rkisp1_ext_params_ie_config {
>>> +	struct rkisp1_ext_params_block_header header;
>>> +	struct rkisp1_cif_isp_ie_config config;
>>> +} __attribute__((aligned(8)));
>>> +
>>> +/**
>>> + * struct rkisp1_ext_params_awb_meas_config - RkISP1 extensible params AWB
>>> + *					      Meas config
>>> + *
>>> + * RkISP1 extensible parameters Auto-White Balance Measurement configuration
>>> + * block. Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS`.
>>> + *
>>> + * @header: The RkISP1 extensible parameters header, see
>>> + *	    :c:type:`rkisp1_ext_params_block_header`
>>> + * @config: Auto-White Balance measure configuration, see
>>> + *	    :c:type:`rkisp1_cif_isp_awb_meas_config`
>>> + */
>>> +struct rkisp1_ext_params_awb_meas_config {
>>> +	struct rkisp1_ext_params_block_header header;
>>> +	struct rkisp1_cif_isp_awb_meas_config config;
>>> +} __attribute__((aligned(8)));
>>> +
>>> +/**
>>> + * struct rkisp1_ext_params_hst_config - RkISP1 extensible params Histogram config
>>> + *
>>> + * RkISP1 extensible parameters Histogram statistics configuration block.
>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS`.
>>> + *
>>> + * @header: The RkISP1 extensible parameters header, see
>>> + *	    :c:type:`rkisp1_ext_params_block_header`
>>> + * @config: Histogram statistics configuration, see
>>> + *	    :c:type:`rkisp1_cif_isp_hst_config`
>>> + */
>>> +struct rkisp1_ext_params_hst_config {
>>> +	struct rkisp1_ext_params_block_header header;
>>> +	struct rkisp1_cif_isp_hst_config config;
>>> +} __attribute__((aligned(8)));
>>> +
>>> +/**
>>> + * struct rkisp1_ext_params_aec_config - RkISP1 extensible params AEC config
>>> + *
>>> + * RkISP1 extensible parameters Auto-Exposure statistics configuration block.
>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS`.
>>> + *
>>> + * @header: The RkISP1 extensible parameters header, see
>>> + *	    :c:type:`rkisp1_ext_params_block_header`
>>> + * @config: Auto-Exposure statistics configuration, see
>>> + *	    :c:type:`rkisp1_cif_isp_aec_config`
>>> + */
>>> +struct rkisp1_ext_params_aec_config {
>>> +	struct rkisp1_ext_params_block_header header;
>>> +	struct rkisp1_cif_isp_aec_config config;
>>> +} __attribute__((aligned(8)));
>>> +
>>> +/**
>>> + * struct rkisp1_ext_params_afc_config - RkISP1 extensible params AFC config
>>> + *
>>> + * RkISP1 extensible parameters Auto-Focus statistics configuration block.
>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS`.
>>> + *
>>> + * @header: The RkISP1 extensible parameters header, see
>>> + *	    :c:type:`rkisp1_ext_params_block_header`
>>> + * @config: Auto-Focus statistics configuration, see
>>> + *	    :c:type:`rkisp1_cif_isp_afc_config`
>>> + */
>>> +struct rkisp1_ext_params_afc_config {
>>> +	struct rkisp1_ext_params_block_header header;
>>> +	struct rkisp1_cif_isp_afc_config config;
>>> +} __attribute__((aligned(8)));
>>> +
>>> +#define RKISP1_EXT_PARAMS_MAX_SIZE					\
>>> +	(sizeof(struct rkisp1_ext_params_bls_config)			+\
>>> +	sizeof(struct rkisp1_ext_params_dpcc_config)			+\
>>> +	sizeof(struct rkisp1_ext_params_sdg_config)			+\
>>> +	sizeof(struct rkisp1_ext_params_lsc_config)			+\
>>> +	sizeof(struct rkisp1_ext_params_awb_gain_config)		+\
>>> +	sizeof(struct rkisp1_ext_params_flt_config)			+\
>>> +	sizeof(struct rkisp1_ext_params_bdm_config)			+\
>>> +	sizeof(struct rkisp1_ext_params_ctk_config)			+\
>>> +	sizeof(struct rkisp1_ext_params_goc_config)			+\
>>> +	sizeof(struct rkisp1_ext_params_dpf_config)			+\
>>> +	sizeof(struct rkisp1_ext_params_dpf_strength_config)		+\
>>> +	sizeof(struct rkisp1_ext_params_cproc_config)			+\
>>> +	sizeof(struct rkisp1_ext_params_ie_config)			+\
>>> +	sizeof(struct rkisp1_ext_params_awb_meas_config)		+\
>>> +	sizeof(struct rkisp1_ext_params_hst_config)			+\
>>> +	sizeof(struct rkisp1_ext_params_aec_config)			+\
>>> +	sizeof(struct rkisp1_ext_params_afc_config))
>>> +
>>> +/**
>>> + * enum rksip1_ext_param_buffer_version - RkISP1 extensible parameters version
>>> + *
>>> + * @RKISP1_EXT_PARAM_BUFFER_V1: First version of RkISP1 extensible parameters
>>> + */
>>> +enum rksip1_ext_param_buffer_version {
>>> +	RKISP1_EXT_PARAM_BUFFER_V1 = 1,
>>> +};
>>> +
>>> +/**
>>> + * struct rkisp1_ext_params_cfg - RkISP1 extensible parameters configuration
>>> + *
>>> + * This struct contains the configuration parameters of the RkISP1 ISP
>>> + * algorithms, serialized by userspace into a data buffer. Each configuration
>>> + * parameter block is represented by a block-specific structure which contains a
>>> + * :c:type:`rkisp1_ext_params_block_header` entry as first member. Userspace
>>> + * populates the @data buffer with configuration parameters for the blocks that
>>> + * it intends to configure. As a consequence, the data buffer effective size
>>> + * changes according to the number of ISP blocks that userspace intends to
>>> + * configure and is set by userspace in the @data_size field.
>>> + *
>>> + * The parameters buffer is versioned by the @version field to allow modifying
>>> + * and extending its definition. Userspace shall populate the @version field to
>>> + * inform the driver about the version it intends to use. The driver will parse
>>> + * and handle the @data buffer according to the data layout specific to the
>>> + * indicated version and return an error if the desired version is not
>>> + * supported.
>>> + *
>>> + * For each ISP block that userspace wants to configure, a block-specific
>>> + * structure is appended to the @data buffer, one after the other without gaps
>>> + * in between nor overlaps. Userspace shall populate the @data_size field with
>>> + * the effective size, in bytes, of the @data buffer.
>>> + *
>>> + * The expected memory layout of the parameters buffer is::
>>> + *
>>> + *	+-------------------- struct rkisp1_ext_params_cfg -------------------+
>>> + *	| version = RKISP_EXT_PARAMS_BUFFER_V1;                               |
>>> + *	| data_size = sizeof(struct rkisp1_ext_params_bls_config)             |
>>> + *	|           + sizeof(struct rkisp1_ext_params_dpcc_config);           |
>>> + *	| +------------------------- data  ---------------------------------+ |
>>> + *	| | +------------- struct rkisp1_ext_params_bls_config -----------+ | |
>>> + *	| | | +-------- struct rkisp1_ext_params_block_header  ---------+ | | |
>>> + *	| | | | type = RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS;                | | | |
>>> + *	| | | | enable = RKISP1_EXT_PARAMS_BLOCK_ENABLE;                | | | |
>>> + *	| | | | size = sizeof(struct rkisp1_ext_params_bls_config);     | | | |
>>> + *	| | | +---------------------------------------------------------+ | | |
>>> + *	| | | +---------- struct rkisp1_cif_isp_bls_config -------------+ | | |
>>> + *	| | | | enable_auto = 0;                                        | | | |
>>> + *	| | | | fixed_val.r = 256;                                      | | | |
>>> + *	| | | | fixed_val.gr = 256;                                     | | | |
>>> + *	| | | | fixed_val.gb = 256;                                     | | | |
>>> + *	| | | | fixed_val.b = 256;                                      | | | |
>>> + *	| | | +---------------------------------------------------------+ | | |
>>> + *	| | +------------ struct rkisp1_ext_params_dpcc_config -----------+ | |
>>> + *	| | | +-------- struct rkisp1_ext_params_block_header  ---------+ | | |
>>> + *	| | | | type = RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC;               | | | |
>>> + *	| | | | enable = RKISP1_EXT_PARAMS_BLOCK_ENABLE;                | | | |
>>> + *	| | | | size = sizeof(struct rkisp1_ext_params_dpcc_config);    | | | |
>>> + *	| | | +---------------------------------------------------------+ | | |
>>> + *	| | | +---------- struct rkisp1_cif_isp_dpcc_config ------------+ | | |
>>> + *	| | | | mode = RKISP1_CIF_ISP_DPCC_MODE_STAGE1_ENABLE;          | | | |
>>> + *	| | | | output_mode =                                           | | | |
>>> + *	| | | |   RKISP1_CIF_ISP_DPCC_OUTPUT_MODE_STAGE1_INCL_G_CENTER; | | | |
>>> + *	| | | | set_use = ... ;                                         | | | |
>>> + *	| | | | ...  = ... ;                                            | | | |
>>> + *	| | | +---------------------------------------------------------+ | | |
>>> + *	| | +-------------------------------------------------------------+ | |
>>> + *	| +-----------------------------------------------------------------+ |
>>> + *	+---------------------------------------------------------------------+
>>> + *
>>> + * @version: The RkISP1 extensible parameters buffer version, see
>>> + *	     :c:type:`rksip1_ext_param_buffer_version`
>>> + * @data_size: The RkISP1 configuration data effective size, excluding this
>>> + *	       header
>>> + * @data: The RkISP1 extensible configuration data blocks
>>> + */
>>> +struct rkisp1_ext_params_cfg {
>>> +	__u32 version;
>>> +	__u32 data_size;
>>> +	__u8 data[RKISP1_EXT_PARAMS_MAX_SIZE];
>>> +};
>>> +
>>>  #endif /* _UAPI_RKISP1_CONFIG_H */
> 

Re: [PATCH v7 01/12] media: uapi: rkisp1-config: Add extensible params format

[Sakari Ailus]

Hi Hans, Laurent,

On Tue, Jul 30, 2024 at 02:37:04PM +0200, Hans Verkuil wrote:
> On 30/07/2024 14:18, Laurent Pinchart wrote:
> > Hi Hans,
> > 
> > On Tue, Jul 30, 2024 at 02:11:12PM +0200, Hans Verkuil wrote:
> >> On 24/07/2024 10:49, Jacopo Mondi wrote:
> >>> Add to the rkisp1-config.h header data types and documentation of
> >>> the extensible parameters format.
> >>>
> >>> Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
> >>> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> >>> Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
> >>> ---
> >>>  include/uapi/linux/rkisp1-config.h | 489 +++++++++++++++++++++++++++++
> >>>  1 file changed, 489 insertions(+)
> >>>
> >>> diff --git a/include/uapi/linux/rkisp1-config.h b/include/uapi/linux/rkisp1-config.h
> >>> index 6eeaf8bf2362..00b09c92cca7 100644
> >>> --- a/include/uapi/linux/rkisp1-config.h
> >>> +++ b/include/uapi/linux/rkisp1-config.h
> >>> @@ -996,4 +996,493 @@ struct rkisp1_stat_buffer {
> >>>  	struct rkisp1_cif_isp_stat params;
> >>>  };
> >>>  
> >>> +/*---------- PART3: Extensible Configuration Parameters  ------------*/
> >>> +
> >>> +/**
> >>> + * enum rkisp1_ext_params_block_type - RkISP1 extensible params block type
> >>> + *
> >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS: Black level subtraction
> >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC: Defect pixel cluster correction
> >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG: Sensor de-gamma
> >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN: Auto white balance gains
> >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT: ISP filtering
> >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM: Bayer de-mosaic
> >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK: Cross-talk correction
> >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC: Gamma out correction
> >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF: De-noise pre-filter
> >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH: De-noise pre-filter strength
> >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC: Color processing
> >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_IE: Image effects
> >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC: Lens shading correction
> >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS: Auto white balance statistics
> >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS: Histogram statistics
> >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS: Auto exposure statistics
> >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS: Auto-focus statistics
> >>> + */
> >>> +enum rkisp1_ext_params_block_type {
> >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS,
> >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC,
> >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG,
> >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN,
> >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT,
> >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM,
> >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK,
> >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC,
> >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF,
> >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH,
> >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC,
> >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_IE,
> >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC,
> >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS,
> >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS,
> >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS,
> >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS,
> >>> +};
> >>> +
> >>> +/**
> >>> + * enum rkisp1_ext_params_block_enable - RkISP1 extensible parameter block
> >>> + *					 enable flags
> >>> + *
> >>> + * @RKISP1_EXT_PARAMS_BLOCK_DISABLE: Disable the HW block
> >>> + * @RKISP1_EXT_PARAMS_BLOCK_ENABLE: Enable the HW block
> >>> + */
> >>> +enum rkisp1_ext_params_block_enable {
> >>> +	RKISP1_EXT_PARAMS_BLOCK_DISABLE,
> >>> +	RKISP1_EXT_PARAMS_BLOCK_ENABLE,
> >>> +};
> >>> +
> >>> +/**
> >>> + * struct rkisp1_ext_params_block_header - RkISP1 extensible parameter block
> >>> + *					   header
> >>> + *
> >>> + * This structure represents the common part of all the ISP configuration
> >>> + * blocks. Each parameters block shall embed an instance of this structure type
> >>> + * as its first member, followed by the block-specific configuration data. The
> >>> + * driver inspects this common header to discern the block type and its size and
> >>> + * properly handle the block content by casting it to the correct block-specific
> >>> + * type.
> >>> + *
> >>> + * The @type field is one of the values enumerated by
> >>> + * :c:type:`rkisp1_ext_params_block_type` and specifies how the data should be
> >>> + * interpreted by the driver. The @size field specifies the size of the
> >>> + * parameters block and is used by the driver for validation purposes.
> >>> + *
> >>> + * The @enable field specifies the ISP block enablement state. The possible
> >>> + * enablement states are enumerated by :c:type:`rkisp1_ext_params_block_enable`.
> >>> + * When userspace needs to configure and enable an ISP block it shall fully
> >>> + * populate the block configuration and the @enable flag shall be set to
> >>> + * RKISP1_EXT_PARAMS_BLOCK_ENABLE. When userspace simply wants to disable the
> >>> + * ISP block the @enable flag shall be set to RKISP1_EXT_PARAMS_BLOCK_DISABLE.
> >>> + * The driver ignores the rest of the block configuration structure in this
> >>> + * case.
> >>> + *
> >>> + * If a new configuration of an ISP block has to be applied userspace shall
> >>> + * fully populate the ISP block configuration and set the @enable flag to
> >>> + * RKISP1_EXT_PARAMS_BLOCK_ENABLE.
> >>> + *
> >>> + * Userspace is responsible for correctly populating the parameters block header
> >>> + * fields (@type, @enable and @size) and the block-specific parameters.
> >>> + *
> >>> + * For example:
> >>> + *
> >>> + * .. code-block:: c
> >>> + *
> >>> + *	void populate_bls(struct rkisp1_ext_params_block_header *block) {
> >>> + *		struct rkisp1_ext_params_bls_config *bls =
> >>> + *			(struct rkisp1_ext_params_bls_config *)block;
> >>> + *
> >>> + *		bls->header.type = RKISP1_EXT_PARAMS_BLOCK_ID_BLS;
> >>> + *		bls->header.enable = RKISP1_EXT_PARAMS_BLOCK_ENABLE;
> >>> + *		bls->header.size = sizeof(*bls);
> >>> + *
> >>> + *		bls->config.enable_auto = 0;
> >>> + *		bls->config.fixed_val.r = blackLevelRed_;
> >>> + *		bls->config.fixed_val.gr = blackLevelGreenR_;
> >>> + *		bls->config.fixed_val.gb = blackLevelGreenB_;
> >>> + *		bls->config.fixed_val.b = blackLevelBlue_;
> >>> + *	}
> >>> + *
> >>> + * @type: The parameters block type, see
> >>> + *	  :c:type:`rkisp1_ext_params_block_type`
> >>> + * @enable: The block enable flag, see
> >>> + *	   :c:type:`rkisp1_ext_params_block_enable`
> >>> + * @size: Size (in bytes) of the parameters block, including this header
> >>> + */
> >>> +struct rkisp1_ext_params_block_header {
> >>> +	__u16 type;
> >>> +	__u16 enable;
> >>> +	__u16 size;
> >>
> >> I would suggest changing this to '__u32 size;'. It ensures the header is8 bytes
> >> long (much nicer than 6), and if there is ever a block > 65535, then it is supported.
> > 
> > I'm pretty confident we will never need a block size larger than 64kB.
> 
> Hmm, famous last words :-)
> 
> > That would mean more than 64kB of data written to hardware
> > registers/SRAM for a single processing block, and it would be incredibly
> > expensive in terms of hardware. Keeping size a __u16 means we have two
> > bytes of reserved space we could possibly use later, which may come
> > handy.
> 
> i would prefer to change the size to a u32, but rename the 'enable' field
> to 'flags', and assign bit 0 to the enable/disable bit. This is a bit
> more flexible IMHO and allows for 15 bits to encode additional data.
> 
>  Blocks > 64kB could still be supported in the future by defining
> > a new version of the parameters format (RKISP1_EXT_PARAM_BUFFER_V2)
> > without needing a different 4CC.

...or making of use the existing padding. Shouldn't that be a reserved
field btw.?

I'm fine either approach, perhaps leaning slightly towards u32 size.

For the series:

Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>

> > 
> > This being said, the opposite argument can be made, that a 32-bit size
> > could come handy if we ever have larger blocks, and a new version of the
> > parameters format could be used if we ever need to add more fields to
> > the block header. I won't insist either way.
> > 
> >> i wonder if, with this change, the 'aligned(8)' attributes are even needed, but
> >> I didn't dig into that.
> > 
> > The header would become 8-bytes long, but its larger field would still
> > be 4-bytes long, so the compiler would only enforce 4-bytes aligned
> > AFAIK.
> 
> Normally the actual data blocks (in the non-extensible format) are already aligned
> to either 4 or 8 bytes (depending on whether u64 values are used). So an 8 byte
> header won't mess up the alignment.

-- 
Kind regards,

Sakari Ailus

Re: [PATCH v7 01/12] media: uapi: rkisp1-config: Add extensible params format

[Jacopo Mondi]

Hi Hans, Laurent

On Tue, Jul 30, 2024 at 02:37:04PM GMT, Hans Verkuil wrote:
> On 30/07/2024 14:18, Laurent Pinchart wrote:
> > Hi Hans,
> >
> > On Tue, Jul 30, 2024 at 02:11:12PM +0200, Hans Verkuil wrote:
> >> On 24/07/2024 10:49, Jacopo Mondi wrote:
> >>> Add to the rkisp1-config.h header data types and documentation of
> >>> the extensible parameters format.
> >>>
> >>> Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
> >>> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> >>> Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
> >>> ---
> >>>  include/uapi/linux/rkisp1-config.h | 489 +++++++++++++++++++++++++++++
> >>>  1 file changed, 489 insertions(+)
> >>>
> >>> diff --git a/include/uapi/linux/rkisp1-config.h b/include/uapi/linux/rkisp1-config.h
> >>> index 6eeaf8bf2362..00b09c92cca7 100644
> >>> --- a/include/uapi/linux/rkisp1-config.h
> >>> +++ b/include/uapi/linux/rkisp1-config.h
> >>> @@ -996,4 +996,493 @@ struct rkisp1_stat_buffer {
> >>>  	struct rkisp1_cif_isp_stat params;
> >>>  };
> >>>
> >>> +/*---------- PART3: Extensible Configuration Parameters  ------------*/
> >>> +
> >>> +/**
> >>> + * enum rkisp1_ext_params_block_type - RkISP1 extensible params block type
> >>> + *
> >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS: Black level subtraction
> >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC: Defect pixel cluster correction
> >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG: Sensor de-gamma
> >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN: Auto white balance gains
> >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT: ISP filtering
> >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM: Bayer de-mosaic
> >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK: Cross-talk correction
> >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC: Gamma out correction
> >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF: De-noise pre-filter
> >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH: De-noise pre-filter strength
> >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC: Color processing
> >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_IE: Image effects
> >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC: Lens shading correction
> >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS: Auto white balance statistics
> >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS: Histogram statistics
> >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS: Auto exposure statistics
> >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS: Auto-focus statistics
> >>> + */
> >>> +enum rkisp1_ext_params_block_type {
> >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS,
> >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC,
> >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG,
> >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN,
> >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT,
> >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM,
> >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK,
> >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC,
> >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF,
> >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH,
> >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC,
> >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_IE,
> >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC,
> >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS,
> >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS,
> >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS,
> >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS,
> >>> +};
> >>> +
> >>> +/**
> >>> + * enum rkisp1_ext_params_block_enable - RkISP1 extensible parameter block
> >>> + *					 enable flags
> >>> + *
> >>> + * @RKISP1_EXT_PARAMS_BLOCK_DISABLE: Disable the HW block
> >>> + * @RKISP1_EXT_PARAMS_BLOCK_ENABLE: Enable the HW block
> >>> + */
> >>> +enum rkisp1_ext_params_block_enable {
> >>> +	RKISP1_EXT_PARAMS_BLOCK_DISABLE,
> >>> +	RKISP1_EXT_PARAMS_BLOCK_ENABLE,
> >>> +};
> >>> +
> >>> +/**
> >>> + * struct rkisp1_ext_params_block_header - RkISP1 extensible parameter block
> >>> + *					   header
> >>> + *
> >>> + * This structure represents the common part of all the ISP configuration
> >>> + * blocks. Each parameters block shall embed an instance of this structure type
> >>> + * as its first member, followed by the block-specific configuration data. The
> >>> + * driver inspects this common header to discern the block type and its size and
> >>> + * properly handle the block content by casting it to the correct block-specific
> >>> + * type.
> >>> + *
> >>> + * The @type field is one of the values enumerated by
> >>> + * :c:type:`rkisp1_ext_params_block_type` and specifies how the data should be
> >>> + * interpreted by the driver. The @size field specifies the size of the
> >>> + * parameters block and is used by the driver for validation purposes.
> >>> + *
> >>> + * The @enable field specifies the ISP block enablement state. The possible
> >>> + * enablement states are enumerated by :c:type:`rkisp1_ext_params_block_enable`.
> >>> + * When userspace needs to configure and enable an ISP block it shall fully
> >>> + * populate the block configuration and the @enable flag shall be set to
> >>> + * RKISP1_EXT_PARAMS_BLOCK_ENABLE. When userspace simply wants to disable the
> >>> + * ISP block the @enable flag shall be set to RKISP1_EXT_PARAMS_BLOCK_DISABLE.
> >>> + * The driver ignores the rest of the block configuration structure in this
> >>> + * case.
> >>> + *
> >>> + * If a new configuration of an ISP block has to be applied userspace shall
> >>> + * fully populate the ISP block configuration and set the @enable flag to
> >>> + * RKISP1_EXT_PARAMS_BLOCK_ENABLE.
> >>> + *
> >>> + * Userspace is responsible for correctly populating the parameters block header
> >>> + * fields (@type, @enable and @size) and the block-specific parameters.
> >>> + *
> >>> + * For example:
> >>> + *
> >>> + * .. code-block:: c
> >>> + *
> >>> + *	void populate_bls(struct rkisp1_ext_params_block_header *block) {
> >>> + *		struct rkisp1_ext_params_bls_config *bls =
> >>> + *			(struct rkisp1_ext_params_bls_config *)block;
> >>> + *
> >>> + *		bls->header.type = RKISP1_EXT_PARAMS_BLOCK_ID_BLS;
> >>> + *		bls->header.enable = RKISP1_EXT_PARAMS_BLOCK_ENABLE;
> >>> + *		bls->header.size = sizeof(*bls);
> >>> + *
> >>> + *		bls->config.enable_auto = 0;
> >>> + *		bls->config.fixed_val.r = blackLevelRed_;
> >>> + *		bls->config.fixed_val.gr = blackLevelGreenR_;
> >>> + *		bls->config.fixed_val.gb = blackLevelGreenB_;
> >>> + *		bls->config.fixed_val.b = blackLevelBlue_;
> >>> + *	}
> >>> + *
> >>> + * @type: The parameters block type, see
> >>> + *	  :c:type:`rkisp1_ext_params_block_type`
> >>> + * @enable: The block enable flag, see
> >>> + *	   :c:type:`rkisp1_ext_params_block_enable`
> >>> + * @size: Size (in bytes) of the parameters block, including this header
> >>> + */
> >>> +struct rkisp1_ext_params_block_header {
> >>> +	__u16 type;
> >>> +	__u16 enable;
> >>> +	__u16 size;
> >>
> >> I would suggest changing this to '__u32 size;'. It ensures the header is8 bytes
> >> long (much nicer than 6), and if there is ever a block > 65535, then it is supported.
> >
> > I'm pretty confident we will never need a block size larger than 64kB.
>
> Hmm, famous last words :-)
>
> > That would mean more than 64kB of data written to hardware
> > registers/SRAM for a single processing block, and it would be incredibly
> > expensive in terms of hardware. Keeping size a __u16 means we have two
> > bytes of reserved space we could possibly use later, which may come
> > handy.
>
> i would prefer to change the size to a u32, but rename the 'enable' field
> to 'flags', and assign bit 0 to the enable/disable bit. This is a bit
> more flexible IMHO and allows for 15 bits to encode additional data.
>
>  Blocks > 64kB could still be supported in the future by defining
> > a new version of the parameters format (RKISP1_EXT_PARAM_BUFFER_V2)
> > without needing a different 4CC.
> >
> > This being said, the opposite argument can be made, that a 32-bit size
> > could come handy if we ever have larger blocks, and a new version of the
> > parameters format could be used if we ever need to add more fields to
> > the block header. I won't insist either way.
> >
> >> i wonder if, with this change, the 'aligned(8)' attributes are even needed, but
> >> I didn't dig into that.
> >
> > The header would become 8-bytes long, but its larger field would still
> > be 4-bytes long, so the compiler would only enforce 4-bytes aligned
> > AFAIK.
>
> Normally the actual data blocks (in the non-extensible format) are already aligned
> to either 4 or 8 bytes (depending on whether u64 values are used). So an 8 byte
> header won't mess up the alignment.

When it come to existing uAPI types (non-extensible) they sometimes
have holes and are aligned by the compiler to the size of the
largest-member, even when embedded in other structure. In example,
cproc is 7 bytes in size

struct rkisp1_cif_isp_cproc_config {
	__u8                       c_out_range;          /*     0     1 */
	__u8                       y_in_range;           /*     1     1 */
	__u8                       y_out_range;          /*     2     1 */
	__u8                       contrast;             /*     3     1 */
	__u8                       brightness;           /*     4     1 */
	__u8                       sat;                  /*     5     1 */
	__u8                       hue;                  /*     6     1 */

	/* size: 7, cachelines: 1, members: 7 */
	/* last cacheline: 7 bytes */
};

And when embedded in the corresponding extensible type it gets aligned
to the size of the largest member in the structure (4 bytes)
regardless if __attribute__((aligned(8)) is specified or not (by
chance, in this case we get a size which is 8-bytes aligned)

struct rkisp1_ext_params_cproc_config {
	struct rkisp1_ext_params_block_header header;    /*     0     8 */
	struct rkisp1_cif_isp_cproc_config config;       /*     8     7 */

	/* size: 16, cachelines: 1, members: 2 */
	/* padding: 1 */
	/* last cacheline: 16 bytes */
};

Other structures are instead aligned to 4 bytes boundary without the
aligned(8) attribute specified, in example BLS:

struct rkisp1_ext_params_bls_config {
	struct rkisp1_ext_params_block_header header;    /*     0     8 */
	struct rkisp1_cif_isp_bls_config config;         /*     8    28 */

	/* XXX last struct has 1 hole */

	/* size: 36, cachelines: 1, members: 2 */
	/* member types with holes: 1, total: 1 */
	/* last cacheline: 36 bytes */
};

Which is not 8 bytes aligned, compared to the 40 bytes long aligned(8)
version here below:

struct rkisp1_ext_params_bls_config {
	struct rkisp1_ext_params_block_header header;    /*     0     8 */
	struct rkisp1_cif_isp_bls_config config;         /*     8    28 */

	/* XXX last struct has 1 hole */

	/* size: 40, cachelines: 1, members: 2 */
	/* padding: 4 */
	/* member types with holes: 1, total: 1 */
	/* last cacheline: 40 bytes */
} __attribute__((__aligned__(8)));

Now, the question is if we want 8 bytes alignment for all structures
or not.

8-bytes alignment is significant when trying to read an 8-byte data
type from a non-8-bytes-aligned address but as far as I can tell there
are no u64 fields in the uAPI and the compiler would have aligned
them anyway, so this is not a concern.

When it comes to 32-bit compatibility (32 bits userspace running on a
64 bits kernel) I don't see any pointer in the uAPI whose size can
change between a 32-bit and a 64-bit system, and all types have their
size specified, so I don't think we would have any issue there.

The extensible data types are serialized in a u8[] data buffer, and
code can access any location within the array by dereferencing a u64
pointer, but there's nothing we can do to prevent this from happening.

As of now, I'm missing the reason why we decided to align everything
to 8 bytes..

>
> Regards,
>
> 	Hans
>
> >
> >> Did you check with pahole for holes etc. in the datastructures?
> >
> > That's a good idea in any case.
> >

As shown in the above examples, existing types have holes, but there's
nothing we can do about it. When embedded in the extensible types,
after the 8-bytes header, they extensible type gets aligned to the
size of the largest member, which is usually the 32-bits large (now
that I made the size member of the header 32-bits).

> >>> +} __attribute__((aligned(8)));
> >>> +
> >>> +/**
> >>> + * struct rkisp1_ext_params_bls_config - RkISP1 extensible params BLS config
> >>> + *
> >>> + * RkISP1 extensible parameters Black Level Subtraction configuration block.
> >>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS`.
> >>> + *
> >>> + * @header: The RkISP1 extensible parameters header, see
> >>> + *	    :c:type:`rkisp1_ext_params_block_header`
> >>> + * @config: Black Level Subtraction configuration, see
> >>> + *	    :c:type:`rkisp1_cif_isp_bls_config`
> >>> + */
> >>> +struct rkisp1_ext_params_bls_config {
> >>> +	struct rkisp1_ext_params_block_header header;
> >>> +	struct rkisp1_cif_isp_bls_config config;
> >>> +} __attribute__((aligned(8)));
> >>> +
> >>> +/**
> >>> + * struct rkisp1_ext_params_dpcc_config - RkISP1 extensible params DPCC config
> >>> + *
> >>> + * RkISP1 extensible parameters Defective Pixel Cluster Correction configuration
> >>> + * block. Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC`.
> >>> + *
> >>> + * @header: The RkISP1 extensible parameters header, see
> >>> + *	    :c:type:`rkisp1_ext_params_block_header`
> >>> + * @config: Defective Pixel Cluster Correction configuration, see
> >>> + *	    :c:type:`rkisp1_cif_isp_dpcc_config`
> >>> + */
> >>> +struct rkisp1_ext_params_dpcc_config {
> >>> +	struct rkisp1_ext_params_block_header header;
> >>> +	struct rkisp1_cif_isp_dpcc_config config;
> >>> +} __attribute__((aligned(8)));
> >>> +
> >>> +/**
> >>> + * struct rkisp1_ext_params_sdg_config - RkISP1 extensible params SDG config
> >>> + *
> >>> + * RkISP1 extensible parameters Sensor Degamma configuration block. Identified
> >>> + * by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG`.
> >>> + *
> >>> + * @header: The RkISP1 extensible parameters header, see
> >>> + *	    :c:type:`rkisp1_ext_params_block_header`
> >>> + * @config: Sensor Degamma configuration, see
> >>> + *	    :c:type:`rkisp1_cif_isp_sdg_config`
> >>> + */
> >>> +struct rkisp1_ext_params_sdg_config {
> >>> +	struct rkisp1_ext_params_block_header header;
> >>> +	struct rkisp1_cif_isp_sdg_config config;
> >>> +} __attribute__((aligned(8)));
> >>> +
> >>> +/**
> >>> + * struct rkisp1_ext_params_lsc_config - RkISP1 extensible params LSC config
> >>> + *
> >>> + * RkISP1 extensible parameters Lens Shading Correction configuration block.
> >>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC`.
> >>> + *
> >>> + * @header: The RkISP1 extensible parameters header, see
> >>> + *	    :c:type:`rkisp1_ext_params_block_header`
> >>> + * @config: Lens Shading Correction configuration, see
> >>> + *	    :c:type:`rkisp1_cif_isp_lsc_config`
> >>> + */
> >>> +struct rkisp1_ext_params_lsc_config {
> >>> +	struct rkisp1_ext_params_block_header header;
> >>> +	struct rkisp1_cif_isp_lsc_config config;
> >>> +} __attribute__((aligned(8)));
> >>> +
> >>> +/**
> >>> + * struct rkisp1_ext_params_awb_gain_config - RkISP1 extensible params AWB
> >>> + *					      gain config
> >>> + *
> >>> + * RkISP1 extensible parameters Auto-White Balance Gains configuration block.
> >>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN`.
> >>> + *
> >>> + * @header: The RkISP1 extensible parameters header, see
> >>> + *	    :c:type:`rkisp1_ext_params_block_header`
> >>> + * @config: Auto-White Balance Gains configuration, see
> >>> + *	    :c:type:`rkisp1_cif_isp_awb_gain_config`
> >>> + */
> >>> +struct rkisp1_ext_params_awb_gain_config {
> >>> +	struct rkisp1_ext_params_block_header header;
> >>> +	struct rkisp1_cif_isp_awb_gain_config config;
> >>> +} __attribute__((aligned(8)));
> >>> +
> >>> +/**
> >>> + * struct rkisp1_ext_params_flt_config - RkISP1 extensible params FLT config
> >>> + *
> >>> + * RkISP1 extensible parameters Filter configuration block. Identified by
> >>> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT`.
> >>> + *
> >>> + * @header: The RkISP1 extensible parameters header, see
> >>> + *	    :c:type:`rkisp1_ext_params_block_header`
> >>> + * @config: Filter configuration, see :c:type:`rkisp1_cif_isp_flt_config`
> >>> + */
> >>> +struct rkisp1_ext_params_flt_config {
> >>> +	struct rkisp1_ext_params_block_header header;
> >>> +	struct rkisp1_cif_isp_flt_config config;
> >>> +} __attribute__((aligned(8)));
> >>> +
> >>> +/**
> >>> + * struct rkisp1_ext_params_bdm_config - RkISP1 extensible params BDM config
> >>> + *
> >>> + * RkISP1 extensible parameters Demosaicing configuration block. Identified by
> >>> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM`.
> >>> + *
> >>> + * @header: The RkISP1 extensible parameters header, see
> >>> + *	    :c:type:`rkisp1_ext_params_block_header`
> >>> + * @config: Demosaicing configuration, see :c:type:`rkisp1_cif_isp_bdm_config`
> >>> + */
> >>> +struct rkisp1_ext_params_bdm_config {
> >>> +	struct rkisp1_ext_params_block_header header;
> >>> +	struct rkisp1_cif_isp_bdm_config config;
> >>> +} __attribute__((aligned(8)));
> >>> +
> >>> +/**
> >>> + * struct rkisp1_ext_params_ctk_config - RkISP1 extensible params CTK config
> >>> + *
> >>> + * RkISP1 extensible parameters Cross-Talk configuration block. Identified by
> >>> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK`.
> >>> + *
> >>> + * @header: The RkISP1 extensible parameters header, see
> >>> + *	    :c:type:`rkisp1_ext_params_block_header`
> >>> + * @config: Cross-Talk configuration, see :c:type:`rkisp1_cif_isp_ctk_config`
> >>> + */
> >>> +struct rkisp1_ext_params_ctk_config {
> >>> +	struct rkisp1_ext_params_block_header header;
> >>> +	struct rkisp1_cif_isp_ctk_config config;
> >>> +} __attribute__((aligned(8)));
> >>> +
> >>> +/**
> >>> + * struct rkisp1_ext_params_goc_config - RkISP1 extensible params GOC config
> >>> + *
> >>> + * RkISP1 extensible parameters Gamma-Out configuration block. Identified by
> >>> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC`.
> >>> + *
> >>> + * @header: The RkISP1 extensible parameters header, see
> >>> + *	    :c:type:`rkisp1_ext_params_block_header`
> >>> + * @config: Gamma-Out configuration, see :c:type:`rkisp1_cif_isp_goc_config`
> >>> + */
> >>> +struct rkisp1_ext_params_goc_config {
> >>> +	struct rkisp1_ext_params_block_header header;
> >>> +	struct rkisp1_cif_isp_goc_config config;
> >>> +} __attribute__((aligned(8)));
> >>> +
> >>> +/**
> >>> + * struct rkisp1_ext_params_dpf_config - RkISP1 extensible params DPF config
> >>> + *
> >>> + * RkISP1 extensible parameters De-noise Pre-Filter configuration block.
> >>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF`.
> >>> + *
> >>> + * @header: The RkISP1 extensible parameters header, see
> >>> + *	    :c:type:`rkisp1_ext_params_block_header`
> >>> + * @config: De-noise Pre-Filter configuration, see
> >>> + *	    :c:type:`rkisp1_cif_isp_dpf_config`
> >>> + */
> >>> +struct rkisp1_ext_params_dpf_config {
> >>> +	struct rkisp1_ext_params_block_header header;
> >>> +	struct rkisp1_cif_isp_dpf_config config;
> >>> +} __attribute__((aligned(8)));
> >>> +
> >>> +/**
> >>> + * struct rkisp1_ext_params_dpf_strength_config - RkISP1 extensible params DPF
> >>> + *						  strength config
> >>> + *
> >>> + * RkISP1 extensible parameters De-noise Pre-Filter strength configuration
> >>> + * block. Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH`.
> >>> + *
> >>> + * @header: The RkISP1 extensible parameters header, see
> >>> + *	    :c:type:`rkisp1_ext_params_block_header`
> >>> + * @config: De-noise Pre-Filter strength configuration, see
> >>> + *	    :c:type:`rkisp1_cif_isp_dpf_strength_config`
> >>> + */
> >>> +struct rkisp1_ext_params_dpf_strength_config {
> >>> +	struct rkisp1_ext_params_block_header header;
> >>> +	struct rkisp1_cif_isp_dpf_strength_config config;
> >>> +} __attribute__((aligned(8)));
> >>> +
> >>> +/**
> >>> + * struct rkisp1_ext_params_cproc_config - RkISP1 extensible params CPROC config
> >>> + *
> >>> + * RkISP1 extensible parameters Color Processing configuration block.
> >>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC`.
> >>> + *
> >>> + * @header: The RkISP1 extensible parameters header, see
> >>> + *	    :c:type:`rkisp1_ext_params_block_header`
> >>> + * @config: Color processing configuration, see
> >>> + *	    :c:type:`rkisp1_cif_isp_cproc_config`
> >>> + */
> >>> +struct rkisp1_ext_params_cproc_config {
> >>> +	struct rkisp1_ext_params_block_header header;
> >>> +	struct rkisp1_cif_isp_cproc_config config;
> >>> +} __attribute__((aligned(8)));
> >>> +
> >>> +/**
> >>> + * struct rkisp1_ext_params_ie_config - RkISP1 extensible params IE config
> >>> + *
> >>> + * RkISP1 extensible parameters Image Effect configuration block. Identified by
> >>> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_IE`.
> >>> + *
> >>> + * @header: The RkISP1 extensible parameters header, see
> >>> + *	    :c:type:`rkisp1_ext_params_block_header`
> >>> + * @config: Image Effect configuration, see :c:type:`rkisp1_cif_isp_ie_config`
> >>> + */
> >>> +struct rkisp1_ext_params_ie_config {
> >>> +	struct rkisp1_ext_params_block_header header;
> >>> +	struct rkisp1_cif_isp_ie_config config;
> >>> +} __attribute__((aligned(8)));
> >>> +
> >>> +/**
> >>> + * struct rkisp1_ext_params_awb_meas_config - RkISP1 extensible params AWB
> >>> + *					      Meas config
> >>> + *
> >>> + * RkISP1 extensible parameters Auto-White Balance Measurement configuration
> >>> + * block. Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS`.
> >>> + *
> >>> + * @header: The RkISP1 extensible parameters header, see
> >>> + *	    :c:type:`rkisp1_ext_params_block_header`
> >>> + * @config: Auto-White Balance measure configuration, see
> >>> + *	    :c:type:`rkisp1_cif_isp_awb_meas_config`
> >>> + */
> >>> +struct rkisp1_ext_params_awb_meas_config {
> >>> +	struct rkisp1_ext_params_block_header header;
> >>> +	struct rkisp1_cif_isp_awb_meas_config config;
> >>> +} __attribute__((aligned(8)));
> >>> +
> >>> +/**
> >>> + * struct rkisp1_ext_params_hst_config - RkISP1 extensible params Histogram config
> >>> + *
> >>> + * RkISP1 extensible parameters Histogram statistics configuration block.
> >>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS`.
> >>> + *
> >>> + * @header: The RkISP1 extensible parameters header, see
> >>> + *	    :c:type:`rkisp1_ext_params_block_header`
> >>> + * @config: Histogram statistics configuration, see
> >>> + *	    :c:type:`rkisp1_cif_isp_hst_config`
> >>> + */
> >>> +struct rkisp1_ext_params_hst_config {
> >>> +	struct rkisp1_ext_params_block_header header;
> >>> +	struct rkisp1_cif_isp_hst_config config;
> >>> +} __attribute__((aligned(8)));
> >>> +
> >>> +/**
> >>> + * struct rkisp1_ext_params_aec_config - RkISP1 extensible params AEC config
> >>> + *
> >>> + * RkISP1 extensible parameters Auto-Exposure statistics configuration block.
> >>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS`.
> >>> + *
> >>> + * @header: The RkISP1 extensible parameters header, see
> >>> + *	    :c:type:`rkisp1_ext_params_block_header`
> >>> + * @config: Auto-Exposure statistics configuration, see
> >>> + *	    :c:type:`rkisp1_cif_isp_aec_config`
> >>> + */
> >>> +struct rkisp1_ext_params_aec_config {
> >>> +	struct rkisp1_ext_params_block_header header;
> >>> +	struct rkisp1_cif_isp_aec_config config;
> >>> +} __attribute__((aligned(8)));
> >>> +
> >>> +/**
> >>> + * struct rkisp1_ext_params_afc_config - RkISP1 extensible params AFC config
> >>> + *
> >>> + * RkISP1 extensible parameters Auto-Focus statistics configuration block.
> >>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS`.
> >>> + *
> >>> + * @header: The RkISP1 extensible parameters header, see
> >>> + *	    :c:type:`rkisp1_ext_params_block_header`
> >>> + * @config: Auto-Focus statistics configuration, see
> >>> + *	    :c:type:`rkisp1_cif_isp_afc_config`
> >>> + */
> >>> +struct rkisp1_ext_params_afc_config {
> >>> +	struct rkisp1_ext_params_block_header header;
> >>> +	struct rkisp1_cif_isp_afc_config config;
> >>> +} __attribute__((aligned(8)));
> >>> +
> >>> +#define RKISP1_EXT_PARAMS_MAX_SIZE					\
> >>> +	(sizeof(struct rkisp1_ext_params_bls_config)			+\
> >>> +	sizeof(struct rkisp1_ext_params_dpcc_config)			+\
> >>> +	sizeof(struct rkisp1_ext_params_sdg_config)			+\
> >>> +	sizeof(struct rkisp1_ext_params_lsc_config)			+\
> >>> +	sizeof(struct rkisp1_ext_params_awb_gain_config)		+\
> >>> +	sizeof(struct rkisp1_ext_params_flt_config)			+\
> >>> +	sizeof(struct rkisp1_ext_params_bdm_config)			+\
> >>> +	sizeof(struct rkisp1_ext_params_ctk_config)			+\
> >>> +	sizeof(struct rkisp1_ext_params_goc_config)			+\
> >>> +	sizeof(struct rkisp1_ext_params_dpf_config)			+\
> >>> +	sizeof(struct rkisp1_ext_params_dpf_strength_config)		+\
> >>> +	sizeof(struct rkisp1_ext_params_cproc_config)			+\
> >>> +	sizeof(struct rkisp1_ext_params_ie_config)			+\
> >>> +	sizeof(struct rkisp1_ext_params_awb_meas_config)		+\
> >>> +	sizeof(struct rkisp1_ext_params_hst_config)			+\
> >>> +	sizeof(struct rkisp1_ext_params_aec_config)			+\
> >>> +	sizeof(struct rkisp1_ext_params_afc_config))
> >>> +
> >>> +/**
> >>> + * enum rksip1_ext_param_buffer_version - RkISP1 extensible parameters version
> >>> + *
> >>> + * @RKISP1_EXT_PARAM_BUFFER_V1: First version of RkISP1 extensible parameters
> >>> + */
> >>> +enum rksip1_ext_param_buffer_version {
> >>> +	RKISP1_EXT_PARAM_BUFFER_V1 = 1,
> >>> +};
> >>> +
> >>> +/**
> >>> + * struct rkisp1_ext_params_cfg - RkISP1 extensible parameters configuration
> >>> + *
> >>> + * This struct contains the configuration parameters of the RkISP1 ISP
> >>> + * algorithms, serialized by userspace into a data buffer. Each configuration
> >>> + * parameter block is represented by a block-specific structure which contains a
> >>> + * :c:type:`rkisp1_ext_params_block_header` entry as first member. Userspace
> >>> + * populates the @data buffer with configuration parameters for the blocks that
> >>> + * it intends to configure. As a consequence, the data buffer effective size
> >>> + * changes according to the number of ISP blocks that userspace intends to
> >>> + * configure and is set by userspace in the @data_size field.
> >>> + *
> >>> + * The parameters buffer is versioned by the @version field to allow modifying
> >>> + * and extending its definition. Userspace shall populate the @version field to
> >>> + * inform the driver about the version it intends to use. The driver will parse
> >>> + * and handle the @data buffer according to the data layout specific to the
> >>> + * indicated version and return an error if the desired version is not
> >>> + * supported.
> >>> + *
> >>> + * For each ISP block that userspace wants to configure, a block-specific
> >>> + * structure is appended to the @data buffer, one after the other without gaps
> >>> + * in between nor overlaps. Userspace shall populate the @data_size field with
> >>> + * the effective size, in bytes, of the @data buffer.
> >>> + *
> >>> + * The expected memory layout of the parameters buffer is::
> >>> + *
> >>> + *	+-------------------- struct rkisp1_ext_params_cfg -------------------+
> >>> + *	| version = RKISP_EXT_PARAMS_BUFFER_V1;                               |
> >>> + *	| data_size = sizeof(struct rkisp1_ext_params_bls_config)             |
> >>> + *	|           + sizeof(struct rkisp1_ext_params_dpcc_config);           |
> >>> + *	| +------------------------- data  ---------------------------------+ |
> >>> + *	| | +------------- struct rkisp1_ext_params_bls_config -----------+ | |
> >>> + *	| | | +-------- struct rkisp1_ext_params_block_header  ---------+ | | |
> >>> + *	| | | | type = RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS;                | | | |
> >>> + *	| | | | enable = RKISP1_EXT_PARAMS_BLOCK_ENABLE;                | | | |
> >>> + *	| | | | size = sizeof(struct rkisp1_ext_params_bls_config);     | | | |
> >>> + *	| | | +---------------------------------------------------------+ | | |
> >>> + *	| | | +---------- struct rkisp1_cif_isp_bls_config -------------+ | | |
> >>> + *	| | | | enable_auto = 0;                                        | | | |
> >>> + *	| | | | fixed_val.r = 256;                                      | | | |
> >>> + *	| | | | fixed_val.gr = 256;                                     | | | |
> >>> + *	| | | | fixed_val.gb = 256;                                     | | | |
> >>> + *	| | | | fixed_val.b = 256;                                      | | | |
> >>> + *	| | | +---------------------------------------------------------+ | | |
> >>> + *	| | +------------ struct rkisp1_ext_params_dpcc_config -----------+ | |
> >>> + *	| | | +-------- struct rkisp1_ext_params_block_header  ---------+ | | |
> >>> + *	| | | | type = RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC;               | | | |
> >>> + *	| | | | enable = RKISP1_EXT_PARAMS_BLOCK_ENABLE;                | | | |
> >>> + *	| | | | size = sizeof(struct rkisp1_ext_params_dpcc_config);    | | | |
> >>> + *	| | | +---------------------------------------------------------+ | | |
> >>> + *	| | | +---------- struct rkisp1_cif_isp_dpcc_config ------------+ | | |
> >>> + *	| | | | mode = RKISP1_CIF_ISP_DPCC_MODE_STAGE1_ENABLE;          | | | |
> >>> + *	| | | | output_mode =                                           | | | |
> >>> + *	| | | |   RKISP1_CIF_ISP_DPCC_OUTPUT_MODE_STAGE1_INCL_G_CENTER; | | | |
> >>> + *	| | | | set_use = ... ;                                         | | | |
> >>> + *	| | | | ...  = ... ;                                            | | | |
> >>> + *	| | | +---------------------------------------------------------+ | | |
> >>> + *	| | +-------------------------------------------------------------+ | |
> >>> + *	| +-----------------------------------------------------------------+ |
> >>> + *	+---------------------------------------------------------------------+
> >>> + *
> >>> + * @version: The RkISP1 extensible parameters buffer version, see
> >>> + *	     :c:type:`rksip1_ext_param_buffer_version`
> >>> + * @data_size: The RkISP1 configuration data effective size, excluding this
> >>> + *	       header
> >>> + * @data: The RkISP1 extensible configuration data blocks
> >>> + */
> >>> +struct rkisp1_ext_params_cfg {
> >>> +	__u32 version;
> >>> +	__u32 data_size;
> >>> +	__u8 data[RKISP1_EXT_PARAMS_MAX_SIZE];
> >>> +};
> >>> +
> >>>  #endif /* _UAPI_RKISP1_CONFIG_H */
> >
>

Re: [PATCH v7 01/12] media: uapi: rkisp1-config: Add extensible params format

[Jacopo Mondi]

Hi Sakari

On Mon, Aug 05, 2024 at 11:52:29AM GMT, Sakari Ailus wrote:
> Hi Hans, Laurent,
>
> On Tue, Jul 30, 2024 at 02:37:04PM +0200, Hans Verkuil wrote:
> > On 30/07/2024 14:18, Laurent Pinchart wrote:
> > > Hi Hans,
> > >
> > > On Tue, Jul 30, 2024 at 02:11:12PM +0200, Hans Verkuil wrote:
> > >> On 24/07/2024 10:49, Jacopo Mondi wrote:
> > >>> Add to the rkisp1-config.h header data types and documentation of
> > >>> the extensible parameters format.
> > >>>
> > >>> Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
> > >>> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > >>> Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
> > >>> ---
> > >>>  include/uapi/linux/rkisp1-config.h | 489 +++++++++++++++++++++++++++++
> > >>>  1 file changed, 489 insertions(+)
> > >>>
> > >>> diff --git a/include/uapi/linux/rkisp1-config.h b/include/uapi/linux/rkisp1-config.h
> > >>> index 6eeaf8bf2362..00b09c92cca7 100644
> > >>> --- a/include/uapi/linux/rkisp1-config.h
> > >>> +++ b/include/uapi/linux/rkisp1-config.h
> > >>> @@ -996,4 +996,493 @@ struct rkisp1_stat_buffer {
> > >>>  	struct rkisp1_cif_isp_stat params;
> > >>>  };
> > >>>
> > >>> +/*---------- PART3: Extensible Configuration Parameters  ------------*/
> > >>> +
> > >>> +/**
> > >>> + * enum rkisp1_ext_params_block_type - RkISP1 extensible params block type
> > >>> + *
> > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS: Black level subtraction
> > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC: Defect pixel cluster correction
> > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG: Sensor de-gamma
> > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN: Auto white balance gains
> > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT: ISP filtering
> > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM: Bayer de-mosaic
> > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK: Cross-talk correction
> > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC: Gamma out correction
> > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF: De-noise pre-filter
> > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH: De-noise pre-filter strength
> > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC: Color processing
> > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_IE: Image effects
> > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC: Lens shading correction
> > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS: Auto white balance statistics
> > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS: Histogram statistics
> > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS: Auto exposure statistics
> > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS: Auto-focus statistics
> > >>> + */
> > >>> +enum rkisp1_ext_params_block_type {
> > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS,
> > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC,
> > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG,
> > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN,
> > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT,
> > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM,
> > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK,
> > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC,
> > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF,
> > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH,
> > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC,
> > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_IE,
> > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC,
> > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS,
> > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS,
> > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS,
> > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS,
> > >>> +};
> > >>> +
> > >>> +/**
> > >>> + * enum rkisp1_ext_params_block_enable - RkISP1 extensible parameter block
> > >>> + *					 enable flags
> > >>> + *
> > >>> + * @RKISP1_EXT_PARAMS_BLOCK_DISABLE: Disable the HW block
> > >>> + * @RKISP1_EXT_PARAMS_BLOCK_ENABLE: Enable the HW block
> > >>> + */
> > >>> +enum rkisp1_ext_params_block_enable {
> > >>> +	RKISP1_EXT_PARAMS_BLOCK_DISABLE,
> > >>> +	RKISP1_EXT_PARAMS_BLOCK_ENABLE,
> > >>> +};
> > >>> +
> > >>> +/**
> > >>> + * struct rkisp1_ext_params_block_header - RkISP1 extensible parameter block
> > >>> + *					   header
> > >>> + *
> > >>> + * This structure represents the common part of all the ISP configuration
> > >>> + * blocks. Each parameters block shall embed an instance of this structure type
> > >>> + * as its first member, followed by the block-specific configuration data. The
> > >>> + * driver inspects this common header to discern the block type and its size and
> > >>> + * properly handle the block content by casting it to the correct block-specific
> > >>> + * type.
> > >>> + *
> > >>> + * The @type field is one of the values enumerated by
> > >>> + * :c:type:`rkisp1_ext_params_block_type` and specifies how the data should be
> > >>> + * interpreted by the driver. The @size field specifies the size of the
> > >>> + * parameters block and is used by the driver for validation purposes.
> > >>> + *
> > >>> + * The @enable field specifies the ISP block enablement state. The possible
> > >>> + * enablement states are enumerated by :c:type:`rkisp1_ext_params_block_enable`.
> > >>> + * When userspace needs to configure and enable an ISP block it shall fully
> > >>> + * populate the block configuration and the @enable flag shall be set to
> > >>> + * RKISP1_EXT_PARAMS_BLOCK_ENABLE. When userspace simply wants to disable the
> > >>> + * ISP block the @enable flag shall be set to RKISP1_EXT_PARAMS_BLOCK_DISABLE.
> > >>> + * The driver ignores the rest of the block configuration structure in this
> > >>> + * case.
> > >>> + *
> > >>> + * If a new configuration of an ISP block has to be applied userspace shall
> > >>> + * fully populate the ISP block configuration and set the @enable flag to
> > >>> + * RKISP1_EXT_PARAMS_BLOCK_ENABLE.
> > >>> + *
> > >>> + * Userspace is responsible for correctly populating the parameters block header
> > >>> + * fields (@type, @enable and @size) and the block-specific parameters.
> > >>> + *
> > >>> + * For example:
> > >>> + *
> > >>> + * .. code-block:: c
> > >>> + *
> > >>> + *	void populate_bls(struct rkisp1_ext_params_block_header *block) {
> > >>> + *		struct rkisp1_ext_params_bls_config *bls =
> > >>> + *			(struct rkisp1_ext_params_bls_config *)block;
> > >>> + *
> > >>> + *		bls->header.type = RKISP1_EXT_PARAMS_BLOCK_ID_BLS;
> > >>> + *		bls->header.enable = RKISP1_EXT_PARAMS_BLOCK_ENABLE;
> > >>> + *		bls->header.size = sizeof(*bls);
> > >>> + *
> > >>> + *		bls->config.enable_auto = 0;
> > >>> + *		bls->config.fixed_val.r = blackLevelRed_;
> > >>> + *		bls->config.fixed_val.gr = blackLevelGreenR_;
> > >>> + *		bls->config.fixed_val.gb = blackLevelGreenB_;
> > >>> + *		bls->config.fixed_val.b = blackLevelBlue_;
> > >>> + *	}
> > >>> + *
> > >>> + * @type: The parameters block type, see
> > >>> + *	  :c:type:`rkisp1_ext_params_block_type`
> > >>> + * @enable: The block enable flag, see
> > >>> + *	   :c:type:`rkisp1_ext_params_block_enable`
> > >>> + * @size: Size (in bytes) of the parameters block, including this header
> > >>> + */
> > >>> +struct rkisp1_ext_params_block_header {
> > >>> +	__u16 type;
> > >>> +	__u16 enable;
> > >>> +	__u16 size;
> > >>
> > >> I would suggest changing this to '__u32 size;'. It ensures the header is8 bytes
> > >> long (much nicer than 6), and if there is ever a block > 65535, then it is supported.
> > >
> > > I'm pretty confident we will never need a block size larger than 64kB.
> >
> > Hmm, famous last words :-)
> >
> > > That would mean more than 64kB of data written to hardware
> > > registers/SRAM for a single processing block, and it would be incredibly
> > > expensive in terms of hardware. Keeping size a __u16 means we have two
> > > bytes of reserved space we could possibly use later, which may come
> > > handy.
> >
> > i would prefer to change the size to a u32, but rename the 'enable' field
> > to 'flags', and assign bit 0 to the enable/disable bit. This is a bit
> > more flexible IMHO and allows for 15 bits to encode additional data.
> >
> >  Blocks > 64kB could still be supported in the future by defining
> > > a new version of the parameters format (RKISP1_EXT_PARAM_BUFFER_V2)
> > > without needing a different 4CC.
>
> ...or making of use the existing padding. Shouldn't that be a reserved
> field btw.?
>

I might have missed what padding to be made a reserved field you are
referring to :)

> I'm fine either approach, perhaps leaning slightly towards u32 size.
>
> For the series:
>
> Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
>
> > >
> > > This being said, the opposite argument can be made, that a 32-bit size
> > > could come handy if we ever have larger blocks, and a new version of the
> > > parameters format could be used if we ever need to add more fields to
> > > the block header. I won't insist either way.
> > >
> > >> i wonder if, with this change, the 'aligned(8)' attributes are even needed, but
> > >> I didn't dig into that.
> > >
> > > The header would become 8-bytes long, but its larger field would still
> > > be 4-bytes long, so the compiler would only enforce 4-bytes aligned
> > > AFAIK.
> >
> > Normally the actual data blocks (in the non-extensible format) are already aligned
> > to either 4 or 8 bytes (depending on whether u64 values are used). So an 8 byte
> > header won't mess up the alignment.
>
> --
> Kind regards,
>
> Sakari Ailus

Re: [PATCH v7 01/12] media: uapi: rkisp1-config: Add extensible params format

[Hans Verkuil]

On 06/08/2024 09:27, Jacopo Mondi wrote:
> Hi Hans, Laurent
> 
> On Tue, Jul 30, 2024 at 02:37:04PM GMT, Hans Verkuil wrote:
>> On 30/07/2024 14:18, Laurent Pinchart wrote:
>>> Hi Hans,
>>>
>>> On Tue, Jul 30, 2024 at 02:11:12PM +0200, Hans Verkuil wrote:
>>>> On 24/07/2024 10:49, Jacopo Mondi wrote:
>>>>> Add to the rkisp1-config.h header data types and documentation of
>>>>> the extensible parameters format.
>>>>>
>>>>> Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
>>>>> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
>>>>> Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
>>>>> ---
>>>>>  include/uapi/linux/rkisp1-config.h | 489 +++++++++++++++++++++++++++++
>>>>>  1 file changed, 489 insertions(+)
>>>>>
>>>>> diff --git a/include/uapi/linux/rkisp1-config.h b/include/uapi/linux/rkisp1-config.h
>>>>> index 6eeaf8bf2362..00b09c92cca7 100644
>>>>> --- a/include/uapi/linux/rkisp1-config.h
>>>>> +++ b/include/uapi/linux/rkisp1-config.h
>>>>> @@ -996,4 +996,493 @@ struct rkisp1_stat_buffer {
>>>>>  	struct rkisp1_cif_isp_stat params;
>>>>>  };
>>>>>
>>>>> +/*---------- PART3: Extensible Configuration Parameters  ------------*/
>>>>> +
>>>>> +/**
>>>>> + * enum rkisp1_ext_params_block_type - RkISP1 extensible params block type
>>>>> + *
>>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS: Black level subtraction
>>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC: Defect pixel cluster correction
>>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG: Sensor de-gamma
>>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN: Auto white balance gains
>>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT: ISP filtering
>>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM: Bayer de-mosaic
>>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK: Cross-talk correction
>>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC: Gamma out correction
>>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF: De-noise pre-filter
>>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH: De-noise pre-filter strength
>>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC: Color processing
>>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_IE: Image effects
>>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC: Lens shading correction
>>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS: Auto white balance statistics
>>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS: Histogram statistics
>>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS: Auto exposure statistics
>>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS: Auto-focus statistics
>>>>> + */
>>>>> +enum rkisp1_ext_params_block_type {
>>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS,
>>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC,
>>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG,
>>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN,
>>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT,
>>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM,
>>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK,
>>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC,
>>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF,
>>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH,
>>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC,
>>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_IE,
>>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC,
>>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS,
>>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS,
>>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS,
>>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS,
>>>>> +};
>>>>> +
>>>>> +/**
>>>>> + * enum rkisp1_ext_params_block_enable - RkISP1 extensible parameter block
>>>>> + *					 enable flags
>>>>> + *
>>>>> + * @RKISP1_EXT_PARAMS_BLOCK_DISABLE: Disable the HW block
>>>>> + * @RKISP1_EXT_PARAMS_BLOCK_ENABLE: Enable the HW block
>>>>> + */
>>>>> +enum rkisp1_ext_params_block_enable {
>>>>> +	RKISP1_EXT_PARAMS_BLOCK_DISABLE,
>>>>> +	RKISP1_EXT_PARAMS_BLOCK_ENABLE,
>>>>> +};
>>>>> +
>>>>> +/**
>>>>> + * struct rkisp1_ext_params_block_header - RkISP1 extensible parameter block
>>>>> + *					   header
>>>>> + *
>>>>> + * This structure represents the common part of all the ISP configuration
>>>>> + * blocks. Each parameters block shall embed an instance of this structure type
>>>>> + * as its first member, followed by the block-specific configuration data. The
>>>>> + * driver inspects this common header to discern the block type and its size and
>>>>> + * properly handle the block content by casting it to the correct block-specific
>>>>> + * type.
>>>>> + *
>>>>> + * The @type field is one of the values enumerated by
>>>>> + * :c:type:`rkisp1_ext_params_block_type` and specifies how the data should be
>>>>> + * interpreted by the driver. The @size field specifies the size of the
>>>>> + * parameters block and is used by the driver for validation purposes.
>>>>> + *
>>>>> + * The @enable field specifies the ISP block enablement state. The possible
>>>>> + * enablement states are enumerated by :c:type:`rkisp1_ext_params_block_enable`.
>>>>> + * When userspace needs to configure and enable an ISP block it shall fully
>>>>> + * populate the block configuration and the @enable flag shall be set to
>>>>> + * RKISP1_EXT_PARAMS_BLOCK_ENABLE. When userspace simply wants to disable the
>>>>> + * ISP block the @enable flag shall be set to RKISP1_EXT_PARAMS_BLOCK_DISABLE.
>>>>> + * The driver ignores the rest of the block configuration structure in this
>>>>> + * case.
>>>>> + *
>>>>> + * If a new configuration of an ISP block has to be applied userspace shall
>>>>> + * fully populate the ISP block configuration and set the @enable flag to
>>>>> + * RKISP1_EXT_PARAMS_BLOCK_ENABLE.
>>>>> + *
>>>>> + * Userspace is responsible for correctly populating the parameters block header
>>>>> + * fields (@type, @enable and @size) and the block-specific parameters.
>>>>> + *
>>>>> + * For example:
>>>>> + *
>>>>> + * .. code-block:: c
>>>>> + *
>>>>> + *	void populate_bls(struct rkisp1_ext_params_block_header *block) {
>>>>> + *		struct rkisp1_ext_params_bls_config *bls =
>>>>> + *			(struct rkisp1_ext_params_bls_config *)block;
>>>>> + *
>>>>> + *		bls->header.type = RKISP1_EXT_PARAMS_BLOCK_ID_BLS;
>>>>> + *		bls->header.enable = RKISP1_EXT_PARAMS_BLOCK_ENABLE;
>>>>> + *		bls->header.size = sizeof(*bls);
>>>>> + *
>>>>> + *		bls->config.enable_auto = 0;
>>>>> + *		bls->config.fixed_val.r = blackLevelRed_;
>>>>> + *		bls->config.fixed_val.gr = blackLevelGreenR_;
>>>>> + *		bls->config.fixed_val.gb = blackLevelGreenB_;
>>>>> + *		bls->config.fixed_val.b = blackLevelBlue_;
>>>>> + *	}
>>>>> + *
>>>>> + * @type: The parameters block type, see
>>>>> + *	  :c:type:`rkisp1_ext_params_block_type`
>>>>> + * @enable: The block enable flag, see
>>>>> + *	   :c:type:`rkisp1_ext_params_block_enable`
>>>>> + * @size: Size (in bytes) of the parameters block, including this header
>>>>> + */
>>>>> +struct rkisp1_ext_params_block_header {
>>>>> +	__u16 type;
>>>>> +	__u16 enable;
>>>>> +	__u16 size;
>>>>
>>>> I would suggest changing this to '__u32 size;'. It ensures the header is8 bytes
>>>> long (much nicer than 6), and if there is ever a block > 65535, then it is supported.
>>>
>>> I'm pretty confident we will never need a block size larger than 64kB.
>>
>> Hmm, famous last words :-)
>>
>>> That would mean more than 64kB of data written to hardware
>>> registers/SRAM for a single processing block, and it would be incredibly
>>> expensive in terms of hardware. Keeping size a __u16 means we have two
>>> bytes of reserved space we could possibly use later, which may come
>>> handy.
>>
>> i would prefer to change the size to a u32, but rename the 'enable' field
>> to 'flags', and assign bit 0 to the enable/disable bit. This is a bit
>> more flexible IMHO and allows for 15 bits to encode additional data.
>>
>>  Blocks > 64kB could still be supported in the future by defining
>>> a new version of the parameters format (RKISP1_EXT_PARAM_BUFFER_V2)
>>> without needing a different 4CC.
>>>
>>> This being said, the opposite argument can be made, that a 32-bit size
>>> could come handy if we ever have larger blocks, and a new version of the
>>> parameters format could be used if we ever need to add more fields to
>>> the block header. I won't insist either way.
>>>
>>>> i wonder if, with this change, the 'aligned(8)' attributes are even needed, but
>>>> I didn't dig into that.
>>>
>>> The header would become 8-bytes long, but its larger field would still
>>> be 4-bytes long, so the compiler would only enforce 4-bytes aligned
>>> AFAIK.
>>
>> Normally the actual data blocks (in the non-extensible format) are already aligned
>> to either 4 or 8 bytes (depending on whether u64 values are used). So an 8 byte
>> header won't mess up the alignment.
> 
> When it come to existing uAPI types (non-extensible) they sometimes
> have holes and are aligned by the compiler to the size of the
> largest-member, even when embedded in other structure. In example,
> cproc is 7 bytes in size
> 
> struct rkisp1_cif_isp_cproc_config {
> 	__u8                       c_out_range;          /*     0     1 */
> 	__u8                       y_in_range;           /*     1     1 */
> 	__u8                       y_out_range;          /*     2     1 */
> 	__u8                       contrast;             /*     3     1 */
> 	__u8                       brightness;           /*     4     1 */
> 	__u8                       sat;                  /*     5     1 */
> 	__u8                       hue;                  /*     6     1 */
> 
> 	/* size: 7, cachelines: 1, members: 7 */
> 	/* last cacheline: 7 bytes */
> };
> 
> And when embedded in the corresponding extensible type it gets aligned
> to the size of the largest member in the structure (4 bytes)
> regardless if __attribute__((aligned(8)) is specified or not (by
> chance, in this case we get a size which is 8-bytes aligned)
> 
> struct rkisp1_ext_params_cproc_config {
> 	struct rkisp1_ext_params_block_header header;    /*     0     8 */
> 	struct rkisp1_cif_isp_cproc_config config;       /*     8     7 */
> 
> 	/* size: 16, cachelines: 1, members: 2 */
> 	/* padding: 1 */
> 	/* last cacheline: 16 bytes */
> };

A potential problem with padding in a public data structure is that you
have to be careful that no memory is leaked in the padding data from the
kernel to userspace.

Another potential problem is if e.g. rkisp1_cif_isp_cproc_config is extended
with a new byte in the future: in that case the new byte would replace the current
padding byte, but applications using the older struct may have left the
padding byte undefined, so the driver can't rely on that byte being 0
when called from such an application.

For compound control (which have similar problems) I have quite strict
requirements: the structure layout may not contain any holes, and I require (and
test) that any reserved/padding fields at set to 0 by the driver and that it is
documented that userspace sets it to 0 as well.

My recommendation for public APIs that effectively return data structures
is to:

1) ensure the layout is the same for 32 and 64 bit code,
2) there are no holes, instead use reserved[] arrays instead,
3) ensure that reserved fields are always set to 0 by the driver,
   and document that userspace sets it to 0 as well. You could chose
   to test for that and fail if it is not 0.

> 
> Other structures are instead aligned to 4 bytes boundary without the
> aligned(8) attribute specified, in example BLS:
> 
> struct rkisp1_ext_params_bls_config {
> 	struct rkisp1_ext_params_block_header header;    /*     0     8 */
> 	struct rkisp1_cif_isp_bls_config config;         /*     8    28 */
> 
> 	/* XXX last struct has 1 hole */
> 
> 	/* size: 36, cachelines: 1, members: 2 */
> 	/* member types with holes: 1, total: 1 */
> 	/* last cacheline: 36 bytes */
> };
> 
> Which is not 8 bytes aligned, compared to the 40 bytes long aligned(8)
> version here below:
> 
> struct rkisp1_ext_params_bls_config {
> 	struct rkisp1_ext_params_block_header header;    /*     0     8 */
> 	struct rkisp1_cif_isp_bls_config config;         /*     8    28 */
> 
> 	/* XXX last struct has 1 hole */
> 
> 	/* size: 40, cachelines: 1, members: 2 */
> 	/* padding: 4 */
> 	/* member types with holes: 1, total: 1 */
> 	/* last cacheline: 40 bytes */
> } __attribute__((__aligned__(8)));
> 
> Now, the question is if we want 8 bytes alignment for all structures
> or not.
> 
> 8-bytes alignment is significant when trying to read an 8-byte data
> type from a non-8-bytes-aligned address but as far as I can tell there
> are no u64 fields in the uAPI and the compiler would have aligned
> them anyway, so this is not a concern.
> 
> When it comes to 32-bit compatibility (32 bits userspace running on a
> 64 bits kernel) I don't see any pointer in the uAPI whose size can
> change between a 32-bit and a 64-bit system, and all types have their
> size specified, so I don't think we would have any issue there.

If there are no u64/s64 fields and no pointers, and you don't expect
to see such things in the future, then there is no need to align to
8 bytes.

> 
> The extensible data types are serialized in a u8[] data buffer, and
> code can access any location within the array by dereferencing a u64
> pointer, but there's nothing we can do to prevent this from happening.
> 
> As of now, I'm missing the reason why we decided to align everything
> to 8 bytes..
> 
>>
>> Regards,
>>
>> 	Hans
>>
>>>
>>>> Did you check with pahole for holes etc. in the datastructures?
>>>
>>> That's a good idea in any case.
>>>
> 
> As shown in the above examples, existing types have holes, but there's
> nothing we can do about it. When embedded in the extensible types,
> after the 8-bytes header, they extensible type gets aligned to the
> size of the largest member, which is usually the 32-bits large (now
> that I made the size member of the header 32-bits).

As mentioned above, I strongly suggest to replace holes with reserved
fields. It avoids potential future problems.

Regards,

	Hans

> 
>>>>> +} __attribute__((aligned(8)));
>>>>> +
>>>>> +/**
>>>>> + * struct rkisp1_ext_params_bls_config - RkISP1 extensible params BLS config
>>>>> + *
>>>>> + * RkISP1 extensible parameters Black Level Subtraction configuration block.
>>>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS`.
>>>>> + *
>>>>> + * @header: The RkISP1 extensible parameters header, see
>>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
>>>>> + * @config: Black Level Subtraction configuration, see
>>>>> + *	    :c:type:`rkisp1_cif_isp_bls_config`
>>>>> + */
>>>>> +struct rkisp1_ext_params_bls_config {
>>>>> +	struct rkisp1_ext_params_block_header header;
>>>>> +	struct rkisp1_cif_isp_bls_config config;
>>>>> +} __attribute__((aligned(8)));
>>>>> +
>>>>> +/**
>>>>> + * struct rkisp1_ext_params_dpcc_config - RkISP1 extensible params DPCC config
>>>>> + *
>>>>> + * RkISP1 extensible parameters Defective Pixel Cluster Correction configuration
>>>>> + * block. Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC`.
>>>>> + *
>>>>> + * @header: The RkISP1 extensible parameters header, see
>>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
>>>>> + * @config: Defective Pixel Cluster Correction configuration, see
>>>>> + *	    :c:type:`rkisp1_cif_isp_dpcc_config`
>>>>> + */
>>>>> +struct rkisp1_ext_params_dpcc_config {
>>>>> +	struct rkisp1_ext_params_block_header header;
>>>>> +	struct rkisp1_cif_isp_dpcc_config config;
>>>>> +} __attribute__((aligned(8)));
>>>>> +
>>>>> +/**
>>>>> + * struct rkisp1_ext_params_sdg_config - RkISP1 extensible params SDG config
>>>>> + *
>>>>> + * RkISP1 extensible parameters Sensor Degamma configuration block. Identified
>>>>> + * by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG`.
>>>>> + *
>>>>> + * @header: The RkISP1 extensible parameters header, see
>>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
>>>>> + * @config: Sensor Degamma configuration, see
>>>>> + *	    :c:type:`rkisp1_cif_isp_sdg_config`
>>>>> + */
>>>>> +struct rkisp1_ext_params_sdg_config {
>>>>> +	struct rkisp1_ext_params_block_header header;
>>>>> +	struct rkisp1_cif_isp_sdg_config config;
>>>>> +} __attribute__((aligned(8)));
>>>>> +
>>>>> +/**
>>>>> + * struct rkisp1_ext_params_lsc_config - RkISP1 extensible params LSC config
>>>>> + *
>>>>> + * RkISP1 extensible parameters Lens Shading Correction configuration block.
>>>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC`.
>>>>> + *
>>>>> + * @header: The RkISP1 extensible parameters header, see
>>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
>>>>> + * @config: Lens Shading Correction configuration, see
>>>>> + *	    :c:type:`rkisp1_cif_isp_lsc_config`
>>>>> + */
>>>>> +struct rkisp1_ext_params_lsc_config {
>>>>> +	struct rkisp1_ext_params_block_header header;
>>>>> +	struct rkisp1_cif_isp_lsc_config config;
>>>>> +} __attribute__((aligned(8)));
>>>>> +
>>>>> +/**
>>>>> + * struct rkisp1_ext_params_awb_gain_config - RkISP1 extensible params AWB
>>>>> + *					      gain config
>>>>> + *
>>>>> + * RkISP1 extensible parameters Auto-White Balance Gains configuration block.
>>>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN`.
>>>>> + *
>>>>> + * @header: The RkISP1 extensible parameters header, see
>>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
>>>>> + * @config: Auto-White Balance Gains configuration, see
>>>>> + *	    :c:type:`rkisp1_cif_isp_awb_gain_config`
>>>>> + */
>>>>> +struct rkisp1_ext_params_awb_gain_config {
>>>>> +	struct rkisp1_ext_params_block_header header;
>>>>> +	struct rkisp1_cif_isp_awb_gain_config config;
>>>>> +} __attribute__((aligned(8)));
>>>>> +
>>>>> +/**
>>>>> + * struct rkisp1_ext_params_flt_config - RkISP1 extensible params FLT config
>>>>> + *
>>>>> + * RkISP1 extensible parameters Filter configuration block. Identified by
>>>>> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT`.
>>>>> + *
>>>>> + * @header: The RkISP1 extensible parameters header, see
>>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
>>>>> + * @config: Filter configuration, see :c:type:`rkisp1_cif_isp_flt_config`
>>>>> + */
>>>>> +struct rkisp1_ext_params_flt_config {
>>>>> +	struct rkisp1_ext_params_block_header header;
>>>>> +	struct rkisp1_cif_isp_flt_config config;
>>>>> +} __attribute__((aligned(8)));
>>>>> +
>>>>> +/**
>>>>> + * struct rkisp1_ext_params_bdm_config - RkISP1 extensible params BDM config
>>>>> + *
>>>>> + * RkISP1 extensible parameters Demosaicing configuration block. Identified by
>>>>> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM`.
>>>>> + *
>>>>> + * @header: The RkISP1 extensible parameters header, see
>>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
>>>>> + * @config: Demosaicing configuration, see :c:type:`rkisp1_cif_isp_bdm_config`
>>>>> + */
>>>>> +struct rkisp1_ext_params_bdm_config {
>>>>> +	struct rkisp1_ext_params_block_header header;
>>>>> +	struct rkisp1_cif_isp_bdm_config config;
>>>>> +} __attribute__((aligned(8)));
>>>>> +
>>>>> +/**
>>>>> + * struct rkisp1_ext_params_ctk_config - RkISP1 extensible params CTK config
>>>>> + *
>>>>> + * RkISP1 extensible parameters Cross-Talk configuration block. Identified by
>>>>> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK`.
>>>>> + *
>>>>> + * @header: The RkISP1 extensible parameters header, see
>>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
>>>>> + * @config: Cross-Talk configuration, see :c:type:`rkisp1_cif_isp_ctk_config`
>>>>> + */
>>>>> +struct rkisp1_ext_params_ctk_config {
>>>>> +	struct rkisp1_ext_params_block_header header;
>>>>> +	struct rkisp1_cif_isp_ctk_config config;
>>>>> +} __attribute__((aligned(8)));
>>>>> +
>>>>> +/**
>>>>> + * struct rkisp1_ext_params_goc_config - RkISP1 extensible params GOC config
>>>>> + *
>>>>> + * RkISP1 extensible parameters Gamma-Out configuration block. Identified by
>>>>> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC`.
>>>>> + *
>>>>> + * @header: The RkISP1 extensible parameters header, see
>>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
>>>>> + * @config: Gamma-Out configuration, see :c:type:`rkisp1_cif_isp_goc_config`
>>>>> + */
>>>>> +struct rkisp1_ext_params_goc_config {
>>>>> +	struct rkisp1_ext_params_block_header header;
>>>>> +	struct rkisp1_cif_isp_goc_config config;
>>>>> +} __attribute__((aligned(8)));
>>>>> +
>>>>> +/**
>>>>> + * struct rkisp1_ext_params_dpf_config - RkISP1 extensible params DPF config
>>>>> + *
>>>>> + * RkISP1 extensible parameters De-noise Pre-Filter configuration block.
>>>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF`.
>>>>> + *
>>>>> + * @header: The RkISP1 extensible parameters header, see
>>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
>>>>> + * @config: De-noise Pre-Filter configuration, see
>>>>> + *	    :c:type:`rkisp1_cif_isp_dpf_config`
>>>>> + */
>>>>> +struct rkisp1_ext_params_dpf_config {
>>>>> +	struct rkisp1_ext_params_block_header header;
>>>>> +	struct rkisp1_cif_isp_dpf_config config;
>>>>> +} __attribute__((aligned(8)));
>>>>> +
>>>>> +/**
>>>>> + * struct rkisp1_ext_params_dpf_strength_config - RkISP1 extensible params DPF
>>>>> + *						  strength config
>>>>> + *
>>>>> + * RkISP1 extensible parameters De-noise Pre-Filter strength configuration
>>>>> + * block. Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH`.
>>>>> + *
>>>>> + * @header: The RkISP1 extensible parameters header, see
>>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
>>>>> + * @config: De-noise Pre-Filter strength configuration, see
>>>>> + *	    :c:type:`rkisp1_cif_isp_dpf_strength_config`
>>>>> + */
>>>>> +struct rkisp1_ext_params_dpf_strength_config {
>>>>> +	struct rkisp1_ext_params_block_header header;
>>>>> +	struct rkisp1_cif_isp_dpf_strength_config config;
>>>>> +} __attribute__((aligned(8)));
>>>>> +
>>>>> +/**
>>>>> + * struct rkisp1_ext_params_cproc_config - RkISP1 extensible params CPROC config
>>>>> + *
>>>>> + * RkISP1 extensible parameters Color Processing configuration block.
>>>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC`.
>>>>> + *
>>>>> + * @header: The RkISP1 extensible parameters header, see
>>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
>>>>> + * @config: Color processing configuration, see
>>>>> + *	    :c:type:`rkisp1_cif_isp_cproc_config`
>>>>> + */
>>>>> +struct rkisp1_ext_params_cproc_config {
>>>>> +	struct rkisp1_ext_params_block_header header;
>>>>> +	struct rkisp1_cif_isp_cproc_config config;
>>>>> +} __attribute__((aligned(8)));
>>>>> +
>>>>> +/**
>>>>> + * struct rkisp1_ext_params_ie_config - RkISP1 extensible params IE config
>>>>> + *
>>>>> + * RkISP1 extensible parameters Image Effect configuration block. Identified by
>>>>> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_IE`.
>>>>> + *
>>>>> + * @header: The RkISP1 extensible parameters header, see
>>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
>>>>> + * @config: Image Effect configuration, see :c:type:`rkisp1_cif_isp_ie_config`
>>>>> + */
>>>>> +struct rkisp1_ext_params_ie_config {
>>>>> +	struct rkisp1_ext_params_block_header header;
>>>>> +	struct rkisp1_cif_isp_ie_config config;
>>>>> +} __attribute__((aligned(8)));
>>>>> +
>>>>> +/**
>>>>> + * struct rkisp1_ext_params_awb_meas_config - RkISP1 extensible params AWB
>>>>> + *					      Meas config
>>>>> + *
>>>>> + * RkISP1 extensible parameters Auto-White Balance Measurement configuration
>>>>> + * block. Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS`.
>>>>> + *
>>>>> + * @header: The RkISP1 extensible parameters header, see
>>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
>>>>> + * @config: Auto-White Balance measure configuration, see
>>>>> + *	    :c:type:`rkisp1_cif_isp_awb_meas_config`
>>>>> + */
>>>>> +struct rkisp1_ext_params_awb_meas_config {
>>>>> +	struct rkisp1_ext_params_block_header header;
>>>>> +	struct rkisp1_cif_isp_awb_meas_config config;
>>>>> +} __attribute__((aligned(8)));
>>>>> +
>>>>> +/**
>>>>> + * struct rkisp1_ext_params_hst_config - RkISP1 extensible params Histogram config
>>>>> + *
>>>>> + * RkISP1 extensible parameters Histogram statistics configuration block.
>>>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS`.
>>>>> + *
>>>>> + * @header: The RkISP1 extensible parameters header, see
>>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
>>>>> + * @config: Histogram statistics configuration, see
>>>>> + *	    :c:type:`rkisp1_cif_isp_hst_config`
>>>>> + */
>>>>> +struct rkisp1_ext_params_hst_config {
>>>>> +	struct rkisp1_ext_params_block_header header;
>>>>> +	struct rkisp1_cif_isp_hst_config config;
>>>>> +} __attribute__((aligned(8)));
>>>>> +
>>>>> +/**
>>>>> + * struct rkisp1_ext_params_aec_config - RkISP1 extensible params AEC config
>>>>> + *
>>>>> + * RkISP1 extensible parameters Auto-Exposure statistics configuration block.
>>>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS`.
>>>>> + *
>>>>> + * @header: The RkISP1 extensible parameters header, see
>>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
>>>>> + * @config: Auto-Exposure statistics configuration, see
>>>>> + *	    :c:type:`rkisp1_cif_isp_aec_config`
>>>>> + */
>>>>> +struct rkisp1_ext_params_aec_config {
>>>>> +	struct rkisp1_ext_params_block_header header;
>>>>> +	struct rkisp1_cif_isp_aec_config config;
>>>>> +} __attribute__((aligned(8)));
>>>>> +
>>>>> +/**
>>>>> + * struct rkisp1_ext_params_afc_config - RkISP1 extensible params AFC config
>>>>> + *
>>>>> + * RkISP1 extensible parameters Auto-Focus statistics configuration block.
>>>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS`.
>>>>> + *
>>>>> + * @header: The RkISP1 extensible parameters header, see
>>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
>>>>> + * @config: Auto-Focus statistics configuration, see
>>>>> + *	    :c:type:`rkisp1_cif_isp_afc_config`
>>>>> + */
>>>>> +struct rkisp1_ext_params_afc_config {
>>>>> +	struct rkisp1_ext_params_block_header header;
>>>>> +	struct rkisp1_cif_isp_afc_config config;
>>>>> +} __attribute__((aligned(8)));
>>>>> +
>>>>> +#define RKISP1_EXT_PARAMS_MAX_SIZE					\
>>>>> +	(sizeof(struct rkisp1_ext_params_bls_config)			+\
>>>>> +	sizeof(struct rkisp1_ext_params_dpcc_config)			+\
>>>>> +	sizeof(struct rkisp1_ext_params_sdg_config)			+\
>>>>> +	sizeof(struct rkisp1_ext_params_lsc_config)			+\
>>>>> +	sizeof(struct rkisp1_ext_params_awb_gain_config)		+\
>>>>> +	sizeof(struct rkisp1_ext_params_flt_config)			+\
>>>>> +	sizeof(struct rkisp1_ext_params_bdm_config)			+\
>>>>> +	sizeof(struct rkisp1_ext_params_ctk_config)			+\
>>>>> +	sizeof(struct rkisp1_ext_params_goc_config)			+\
>>>>> +	sizeof(struct rkisp1_ext_params_dpf_config)			+\
>>>>> +	sizeof(struct rkisp1_ext_params_dpf_strength_config)		+\
>>>>> +	sizeof(struct rkisp1_ext_params_cproc_config)			+\
>>>>> +	sizeof(struct rkisp1_ext_params_ie_config)			+\
>>>>> +	sizeof(struct rkisp1_ext_params_awb_meas_config)		+\
>>>>> +	sizeof(struct rkisp1_ext_params_hst_config)			+\
>>>>> +	sizeof(struct rkisp1_ext_params_aec_config)			+\
>>>>> +	sizeof(struct rkisp1_ext_params_afc_config))
>>>>> +
>>>>> +/**
>>>>> + * enum rksip1_ext_param_buffer_version - RkISP1 extensible parameters version
>>>>> + *
>>>>> + * @RKISP1_EXT_PARAM_BUFFER_V1: First version of RkISP1 extensible parameters
>>>>> + */
>>>>> +enum rksip1_ext_param_buffer_version {
>>>>> +	RKISP1_EXT_PARAM_BUFFER_V1 = 1,
>>>>> +};
>>>>> +
>>>>> +/**
>>>>> + * struct rkisp1_ext_params_cfg - RkISP1 extensible parameters configuration
>>>>> + *
>>>>> + * This struct contains the configuration parameters of the RkISP1 ISP
>>>>> + * algorithms, serialized by userspace into a data buffer. Each configuration
>>>>> + * parameter block is represented by a block-specific structure which contains a
>>>>> + * :c:type:`rkisp1_ext_params_block_header` entry as first member. Userspace
>>>>> + * populates the @data buffer with configuration parameters for the blocks that
>>>>> + * it intends to configure. As a consequence, the data buffer effective size
>>>>> + * changes according to the number of ISP blocks that userspace intends to
>>>>> + * configure and is set by userspace in the @data_size field.
>>>>> + *
>>>>> + * The parameters buffer is versioned by the @version field to allow modifying
>>>>> + * and extending its definition. Userspace shall populate the @version field to
>>>>> + * inform the driver about the version it intends to use. The driver will parse
>>>>> + * and handle the @data buffer according to the data layout specific to the
>>>>> + * indicated version and return an error if the desired version is not
>>>>> + * supported.
>>>>> + *
>>>>> + * For each ISP block that userspace wants to configure, a block-specific
>>>>> + * structure is appended to the @data buffer, one after the other without gaps
>>>>> + * in between nor overlaps. Userspace shall populate the @data_size field with
>>>>> + * the effective size, in bytes, of the @data buffer.
>>>>> + *
>>>>> + * The expected memory layout of the parameters buffer is::
>>>>> + *
>>>>> + *	+-------------------- struct rkisp1_ext_params_cfg -------------------+
>>>>> + *	| version = RKISP_EXT_PARAMS_BUFFER_V1;                               |
>>>>> + *	| data_size = sizeof(struct rkisp1_ext_params_bls_config)             |
>>>>> + *	|           + sizeof(struct rkisp1_ext_params_dpcc_config);           |
>>>>> + *	| +------------------------- data  ---------------------------------+ |
>>>>> + *	| | +------------- struct rkisp1_ext_params_bls_config -----------+ | |
>>>>> + *	| | | +-------- struct rkisp1_ext_params_block_header  ---------+ | | |
>>>>> + *	| | | | type = RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS;                | | | |
>>>>> + *	| | | | enable = RKISP1_EXT_PARAMS_BLOCK_ENABLE;                | | | |
>>>>> + *	| | | | size = sizeof(struct rkisp1_ext_params_bls_config);     | | | |
>>>>> + *	| | | +---------------------------------------------------------+ | | |
>>>>> + *	| | | +---------- struct rkisp1_cif_isp_bls_config -------------+ | | |
>>>>> + *	| | | | enable_auto = 0;                                        | | | |
>>>>> + *	| | | | fixed_val.r = 256;                                      | | | |
>>>>> + *	| | | | fixed_val.gr = 256;                                     | | | |
>>>>> + *	| | | | fixed_val.gb = 256;                                     | | | |
>>>>> + *	| | | | fixed_val.b = 256;                                      | | | |
>>>>> + *	| | | +---------------------------------------------------------+ | | |
>>>>> + *	| | +------------ struct rkisp1_ext_params_dpcc_config -----------+ | |
>>>>> + *	| | | +-------- struct rkisp1_ext_params_block_header  ---------+ | | |
>>>>> + *	| | | | type = RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC;               | | | |
>>>>> + *	| | | | enable = RKISP1_EXT_PARAMS_BLOCK_ENABLE;                | | | |
>>>>> + *	| | | | size = sizeof(struct rkisp1_ext_params_dpcc_config);    | | | |
>>>>> + *	| | | +---------------------------------------------------------+ | | |
>>>>> + *	| | | +---------- struct rkisp1_cif_isp_dpcc_config ------------+ | | |
>>>>> + *	| | | | mode = RKISP1_CIF_ISP_DPCC_MODE_STAGE1_ENABLE;          | | | |
>>>>> + *	| | | | output_mode =                                           | | | |
>>>>> + *	| | | |   RKISP1_CIF_ISP_DPCC_OUTPUT_MODE_STAGE1_INCL_G_CENTER; | | | |
>>>>> + *	| | | | set_use = ... ;                                         | | | |
>>>>> + *	| | | | ...  = ... ;                                            | | | |
>>>>> + *	| | | +---------------------------------------------------------+ | | |
>>>>> + *	| | +-------------------------------------------------------------+ | |
>>>>> + *	| +-----------------------------------------------------------------+ |
>>>>> + *	+---------------------------------------------------------------------+
>>>>> + *
>>>>> + * @version: The RkISP1 extensible parameters buffer version, see
>>>>> + *	     :c:type:`rksip1_ext_param_buffer_version`
>>>>> + * @data_size: The RkISP1 configuration data effective size, excluding this
>>>>> + *	       header
>>>>> + * @data: The RkISP1 extensible configuration data blocks
>>>>> + */
>>>>> +struct rkisp1_ext_params_cfg {
>>>>> +	__u32 version;
>>>>> +	__u32 data_size;
>>>>> +	__u8 data[RKISP1_EXT_PARAMS_MAX_SIZE];
>>>>> +};
>>>>> +
>>>>>  #endif /* _UAPI_RKISP1_CONFIG_H */
>>>
>>

Re: [PATCH v7 01/12] media: uapi: rkisp1-config: Add extensible params format

[Jacopo Mondi]

Hi Hans

On Tue, Aug 06, 2024 at 10:17:02AM GMT, Hans Verkuil wrote:
> On 06/08/2024 09:27, Jacopo Mondi wrote:
> > Hi Hans, Laurent
> >
> > On Tue, Jul 30, 2024 at 02:37:04PM GMT, Hans Verkuil wrote:
> >> On 30/07/2024 14:18, Laurent Pinchart wrote:
> >>> Hi Hans,
> >>>
> >>> On Tue, Jul 30, 2024 at 02:11:12PM +0200, Hans Verkuil wrote:
> >>>> On 24/07/2024 10:49, Jacopo Mondi wrote:
> >>>>> Add to the rkisp1-config.h header data types and documentation of
> >>>>> the extensible parameters format.
> >>>>>
> >>>>> Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
> >>>>> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> >>>>> Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
> >>>>> ---
> >>>>>  include/uapi/linux/rkisp1-config.h | 489 +++++++++++++++++++++++++++++
> >>>>>  1 file changed, 489 insertions(+)
> >>>>>
> >>>>> diff --git a/include/uapi/linux/rkisp1-config.h b/include/uapi/linux/rkisp1-config.h
> >>>>> index 6eeaf8bf2362..00b09c92cca7 100644
> >>>>> --- a/include/uapi/linux/rkisp1-config.h
> >>>>> +++ b/include/uapi/linux/rkisp1-config.h
> >>>>> @@ -996,4 +996,493 @@ struct rkisp1_stat_buffer {
> >>>>>  	struct rkisp1_cif_isp_stat params;
> >>>>>  };
> >>>>>
> >>>>> +/*---------- PART3: Extensible Configuration Parameters  ------------*/
> >>>>> +
> >>>>> +/**
> >>>>> + * enum rkisp1_ext_params_block_type - RkISP1 extensible params block type
> >>>>> + *
> >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS: Black level subtraction
> >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC: Defect pixel cluster correction
> >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG: Sensor de-gamma
> >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN: Auto white balance gains
> >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT: ISP filtering
> >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM: Bayer de-mosaic
> >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK: Cross-talk correction
> >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC: Gamma out correction
> >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF: De-noise pre-filter
> >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH: De-noise pre-filter strength
> >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC: Color processing
> >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_IE: Image effects
> >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC: Lens shading correction
> >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS: Auto white balance statistics
> >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS: Histogram statistics
> >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS: Auto exposure statistics
> >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS: Auto-focus statistics
> >>>>> + */
> >>>>> +enum rkisp1_ext_params_block_type {
> >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS,
> >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC,
> >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG,
> >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN,
> >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT,
> >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM,
> >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK,
> >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC,
> >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF,
> >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH,
> >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC,
> >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_IE,
> >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC,
> >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS,
> >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS,
> >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS,
> >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS,
> >>>>> +};
> >>>>> +
> >>>>> +/**
> >>>>> + * enum rkisp1_ext_params_block_enable - RkISP1 extensible parameter block
> >>>>> + *					 enable flags
> >>>>> + *
> >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_DISABLE: Disable the HW block
> >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_ENABLE: Enable the HW block
> >>>>> + */
> >>>>> +enum rkisp1_ext_params_block_enable {
> >>>>> +	RKISP1_EXT_PARAMS_BLOCK_DISABLE,
> >>>>> +	RKISP1_EXT_PARAMS_BLOCK_ENABLE,
> >>>>> +};
> >>>>> +
> >>>>> +/**
> >>>>> + * struct rkisp1_ext_params_block_header - RkISP1 extensible parameter block
> >>>>> + *					   header
> >>>>> + *
> >>>>> + * This structure represents the common part of all the ISP configuration
> >>>>> + * blocks. Each parameters block shall embed an instance of this structure type
> >>>>> + * as its first member, followed by the block-specific configuration data. The
> >>>>> + * driver inspects this common header to discern the block type and its size and
> >>>>> + * properly handle the block content by casting it to the correct block-specific
> >>>>> + * type.
> >>>>> + *
> >>>>> + * The @type field is one of the values enumerated by
> >>>>> + * :c:type:`rkisp1_ext_params_block_type` and specifies how the data should be
> >>>>> + * interpreted by the driver. The @size field specifies the size of the
> >>>>> + * parameters block and is used by the driver for validation purposes.
> >>>>> + *
> >>>>> + * The @enable field specifies the ISP block enablement state. The possible
> >>>>> + * enablement states are enumerated by :c:type:`rkisp1_ext_params_block_enable`.
> >>>>> + * When userspace needs to configure and enable an ISP block it shall fully
> >>>>> + * populate the block configuration and the @enable flag shall be set to
> >>>>> + * RKISP1_EXT_PARAMS_BLOCK_ENABLE. When userspace simply wants to disable the
> >>>>> + * ISP block the @enable flag shall be set to RKISP1_EXT_PARAMS_BLOCK_DISABLE.
> >>>>> + * The driver ignores the rest of the block configuration structure in this
> >>>>> + * case.
> >>>>> + *
> >>>>> + * If a new configuration of an ISP block has to be applied userspace shall
> >>>>> + * fully populate the ISP block configuration and set the @enable flag to
> >>>>> + * RKISP1_EXT_PARAMS_BLOCK_ENABLE.
> >>>>> + *
> >>>>> + * Userspace is responsible for correctly populating the parameters block header
> >>>>> + * fields (@type, @enable and @size) and the block-specific parameters.
> >>>>> + *
> >>>>> + * For example:
> >>>>> + *
> >>>>> + * .. code-block:: c
> >>>>> + *
> >>>>> + *	void populate_bls(struct rkisp1_ext_params_block_header *block) {
> >>>>> + *		struct rkisp1_ext_params_bls_config *bls =
> >>>>> + *			(struct rkisp1_ext_params_bls_config *)block;
> >>>>> + *
> >>>>> + *		bls->header.type = RKISP1_EXT_PARAMS_BLOCK_ID_BLS;
> >>>>> + *		bls->header.enable = RKISP1_EXT_PARAMS_BLOCK_ENABLE;
> >>>>> + *		bls->header.size = sizeof(*bls);
> >>>>> + *
> >>>>> + *		bls->config.enable_auto = 0;
> >>>>> + *		bls->config.fixed_val.r = blackLevelRed_;
> >>>>> + *		bls->config.fixed_val.gr = blackLevelGreenR_;
> >>>>> + *		bls->config.fixed_val.gb = blackLevelGreenB_;
> >>>>> + *		bls->config.fixed_val.b = blackLevelBlue_;
> >>>>> + *	}
> >>>>> + *
> >>>>> + * @type: The parameters block type, see
> >>>>> + *	  :c:type:`rkisp1_ext_params_block_type`
> >>>>> + * @enable: The block enable flag, see
> >>>>> + *	   :c:type:`rkisp1_ext_params_block_enable`
> >>>>> + * @size: Size (in bytes) of the parameters block, including this header
> >>>>> + */
> >>>>> +struct rkisp1_ext_params_block_header {
> >>>>> +	__u16 type;
> >>>>> +	__u16 enable;
> >>>>> +	__u16 size;
> >>>>
> >>>> I would suggest changing this to '__u32 size;'. It ensures the header is8 bytes
> >>>> long (much nicer than 6), and if there is ever a block > 65535, then it is supported.
> >>>
> >>> I'm pretty confident we will never need a block size larger than 64kB.
> >>
> >> Hmm, famous last words :-)
> >>
> >>> That would mean more than 64kB of data written to hardware
> >>> registers/SRAM for a single processing block, and it would be incredibly
> >>> expensive in terms of hardware. Keeping size a __u16 means we have two
> >>> bytes of reserved space we could possibly use later, which may come
> >>> handy.
> >>
> >> i would prefer to change the size to a u32, but rename the 'enable' field
> >> to 'flags', and assign bit 0 to the enable/disable bit. This is a bit
> >> more flexible IMHO and allows for 15 bits to encode additional data.
> >>
> >>  Blocks > 64kB could still be supported in the future by defining
> >>> a new version of the parameters format (RKISP1_EXT_PARAM_BUFFER_V2)
> >>> without needing a different 4CC.
> >>>
> >>> This being said, the opposite argument can be made, that a 32-bit size
> >>> could come handy if we ever have larger blocks, and a new version of the
> >>> parameters format could be used if we ever need to add more fields to
> >>> the block header. I won't insist either way.
> >>>
> >>>> i wonder if, with this change, the 'aligned(8)' attributes are even needed, but
> >>>> I didn't dig into that.
> >>>
> >>> The header would become 8-bytes long, but its larger field would still
> >>> be 4-bytes long, so the compiler would only enforce 4-bytes aligned
> >>> AFAIK.
> >>
> >> Normally the actual data blocks (in the non-extensible format) are already aligned
> >> to either 4 or 8 bytes (depending on whether u64 values are used). So an 8 byte
> >> header won't mess up the alignment.
> >
> > When it come to existing uAPI types (non-extensible) they sometimes
> > have holes and are aligned by the compiler to the size of the
> > largest-member, even when embedded in other structure. In example,
> > cproc is 7 bytes in size
> >
> > struct rkisp1_cif_isp_cproc_config {
> > 	__u8                       c_out_range;          /*     0     1 */
> > 	__u8                       y_in_range;           /*     1     1 */
> > 	__u8                       y_out_range;          /*     2     1 */
> > 	__u8                       contrast;             /*     3     1 */
> > 	__u8                       brightness;           /*     4     1 */
> > 	__u8                       sat;                  /*     5     1 */
> > 	__u8                       hue;                  /*     6     1 */
> >
> > 	/* size: 7, cachelines: 1, members: 7 */
> > 	/* last cacheline: 7 bytes */
> > };
> >
> > And when embedded in the corresponding extensible type it gets aligned
> > to the size of the largest member in the structure (4 bytes)
> > regardless if __attribute__((aligned(8)) is specified or not (by
> > chance, in this case we get a size which is 8-bytes aligned)
> >
> > struct rkisp1_ext_params_cproc_config {
> > 	struct rkisp1_ext_params_block_header header;    /*     0     8 */
> > 	struct rkisp1_cif_isp_cproc_config config;       /*     8     7 */
> >
> > 	/* size: 16, cachelines: 1, members: 2 */
> > 	/* padding: 1 */
> > 	/* last cacheline: 16 bytes */
> > };
>
> A potential problem with padding in a public data structure is that you
> have to be careful that no memory is leaked in the padding data from the
> kernel to userspace.

I agree with all the above, but keep in mind the above type is already
part of the uAPI (the so-called FIXED format) and I cannot change it
without changing the associated V4L2_META_FMT_RK_ISP1_PARAMS pixel format.

>
> Another potential problem is if e.g. rkisp1_cif_isp_cproc_config is extended
> with a new byte in the future: in that case the new byte would replace the current
> padding byte, but applications using the older struct may have left the
> padding byte undefined, so the driver can't rely on that byte being 0
> when called from such an application.

This can't happen with the existing fixed V4L2_META_FMT_RK_ISP1_PARAMS
format. If the uAPI types change, a new pixel format would be
needed. That's why we introduced the new extensible (and versioned) format :)

>
> For compound control (which have similar problems) I have quite strict
> requirements: the structure layout may not contain any holes, and I require (and
> test) that any reserved/padding fields at set to 0 by the driver and that it is
> documented that userspace sets it to 0 as well.
>
> My recommendation for public APIs that effectively return data structures
> is to:
>
> 1) ensure the layout is the same for 32 and 64 bit code,
> 2) there are no holes, instead use reserved[] arrays instead,
> 3) ensure that reserved fields are always set to 0 by the driver,
>    and document that userspace sets it to 0 as well. You could chose
>    to test for that and fail if it is not 0.
>
> >
> > Other structures are instead aligned to 4 bytes boundary without the
> > aligned(8) attribute specified, in example BLS:
> >
> > struct rkisp1_ext_params_bls_config {
> > 	struct rkisp1_ext_params_block_header header;    /*     0     8 */
> > 	struct rkisp1_cif_isp_bls_config config;         /*     8    28 */
> >
> > 	/* XXX last struct has 1 hole */
> >
> > 	/* size: 36, cachelines: 1, members: 2 */
> > 	/* member types with holes: 1, total: 1 */
> > 	/* last cacheline: 36 bytes */
> > };
> >
> > Which is not 8 bytes aligned, compared to the 40 bytes long aligned(8)
> > version here below:
> >
> > struct rkisp1_ext_params_bls_config {
> > 	struct rkisp1_ext_params_block_header header;    /*     0     8 */
> > 	struct rkisp1_cif_isp_bls_config config;         /*     8    28 */
> >
> > 	/* XXX last struct has 1 hole */
> >
> > 	/* size: 40, cachelines: 1, members: 2 */
> > 	/* padding: 4 */
> > 	/* member types with holes: 1, total: 1 */
> > 	/* last cacheline: 40 bytes */
> > } __attribute__((__aligned__(8)));
> >
> > Now, the question is if we want 8 bytes alignment for all structures
> > or not.
> >
> > 8-bytes alignment is significant when trying to read an 8-byte data
> > type from a non-8-bytes-aligned address but as far as I can tell there
> > are no u64 fields in the uAPI and the compiler would have aligned
> > them anyway, so this is not a concern.
> >
> > When it comes to 32-bit compatibility (32 bits userspace running on a
> > 64 bits kernel) I don't see any pointer in the uAPI whose size can
> > change between a 32-bit and a 64-bit system, and all types have their
> > size specified, so I don't think we would have any issue there.
>
> If there are no u64/s64 fields and no pointers, and you don't expect
> to see such things in the future, then there is no need to align to
> 8 bytes.
>
> >
> > The extensible data types are serialized in a u8[] data buffer, and
> > code can access any location within the array by dereferencing a u64
> > pointer, but there's nothing we can do to prevent this from happening.
> >
> > As of now, I'm missing the reason why we decided to align everything
> > to 8 bytes..
> >
> >>
> >> Regards,
> >>
> >> 	Hans
> >>
> >>>
> >>>> Did you check with pahole for holes etc. in the datastructures?
> >>>
> >>> That's a good idea in any case.
> >>>
> >
> > As shown in the above examples, existing types have holes, but there's
> > nothing we can do about it. When embedded in the extensible types,
> > after the 8-bytes header, they extensible type gets aligned to the
> > size of the largest member, which is usually the 32-bits large (now
> > that I made the size member of the header 32-bits).
>
> As mentioned above, I strongly suggest to replace holes with reserved
> fields. It avoids potential future problems.
>

Agreed, but unfortunately I cannot change the existing types
associated with V4L2_META_FMT_RK_ISP1_PARAMS..


> Regards,
>
> 	Hans
>
> >
> >>>>> +} __attribute__((aligned(8)));
> >>>>> +
> >>>>> +/**
> >>>>> + * struct rkisp1_ext_params_bls_config - RkISP1 extensible params BLS config
> >>>>> + *
> >>>>> + * RkISP1 extensible parameters Black Level Subtraction configuration block.
> >>>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS`.
> >>>>> + *
> >>>>> + * @header: The RkISP1 extensible parameters header, see
> >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> >>>>> + * @config: Black Level Subtraction configuration, see
> >>>>> + *	    :c:type:`rkisp1_cif_isp_bls_config`
> >>>>> + */
> >>>>> +struct rkisp1_ext_params_bls_config {
> >>>>> +	struct rkisp1_ext_params_block_header header;
> >>>>> +	struct rkisp1_cif_isp_bls_config config;
> >>>>> +} __attribute__((aligned(8)));
> >>>>> +
> >>>>> +/**
> >>>>> + * struct rkisp1_ext_params_dpcc_config - RkISP1 extensible params DPCC config
> >>>>> + *
> >>>>> + * RkISP1 extensible parameters Defective Pixel Cluster Correction configuration
> >>>>> + * block. Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC`.
> >>>>> + *
> >>>>> + * @header: The RkISP1 extensible parameters header, see
> >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> >>>>> + * @config: Defective Pixel Cluster Correction configuration, see
> >>>>> + *	    :c:type:`rkisp1_cif_isp_dpcc_config`
> >>>>> + */
> >>>>> +struct rkisp1_ext_params_dpcc_config {
> >>>>> +	struct rkisp1_ext_params_block_header header;
> >>>>> +	struct rkisp1_cif_isp_dpcc_config config;
> >>>>> +} __attribute__((aligned(8)));
> >>>>> +
> >>>>> +/**
> >>>>> + * struct rkisp1_ext_params_sdg_config - RkISP1 extensible params SDG config
> >>>>> + *
> >>>>> + * RkISP1 extensible parameters Sensor Degamma configuration block. Identified
> >>>>> + * by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG`.
> >>>>> + *
> >>>>> + * @header: The RkISP1 extensible parameters header, see
> >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> >>>>> + * @config: Sensor Degamma configuration, see
> >>>>> + *	    :c:type:`rkisp1_cif_isp_sdg_config`
> >>>>> + */
> >>>>> +struct rkisp1_ext_params_sdg_config {
> >>>>> +	struct rkisp1_ext_params_block_header header;
> >>>>> +	struct rkisp1_cif_isp_sdg_config config;
> >>>>> +} __attribute__((aligned(8)));
> >>>>> +
> >>>>> +/**
> >>>>> + * struct rkisp1_ext_params_lsc_config - RkISP1 extensible params LSC config
> >>>>> + *
> >>>>> + * RkISP1 extensible parameters Lens Shading Correction configuration block.
> >>>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC`.
> >>>>> + *
> >>>>> + * @header: The RkISP1 extensible parameters header, see
> >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> >>>>> + * @config: Lens Shading Correction configuration, see
> >>>>> + *	    :c:type:`rkisp1_cif_isp_lsc_config`
> >>>>> + */
> >>>>> +struct rkisp1_ext_params_lsc_config {
> >>>>> +	struct rkisp1_ext_params_block_header header;
> >>>>> +	struct rkisp1_cif_isp_lsc_config config;
> >>>>> +} __attribute__((aligned(8)));
> >>>>> +
> >>>>> +/**
> >>>>> + * struct rkisp1_ext_params_awb_gain_config - RkISP1 extensible params AWB
> >>>>> + *					      gain config
> >>>>> + *
> >>>>> + * RkISP1 extensible parameters Auto-White Balance Gains configuration block.
> >>>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN`.
> >>>>> + *
> >>>>> + * @header: The RkISP1 extensible parameters header, see
> >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> >>>>> + * @config: Auto-White Balance Gains configuration, see
> >>>>> + *	    :c:type:`rkisp1_cif_isp_awb_gain_config`
> >>>>> + */
> >>>>> +struct rkisp1_ext_params_awb_gain_config {
> >>>>> +	struct rkisp1_ext_params_block_header header;
> >>>>> +	struct rkisp1_cif_isp_awb_gain_config config;
> >>>>> +} __attribute__((aligned(8)));
> >>>>> +
> >>>>> +/**
> >>>>> + * struct rkisp1_ext_params_flt_config - RkISP1 extensible params FLT config
> >>>>> + *
> >>>>> + * RkISP1 extensible parameters Filter configuration block. Identified by
> >>>>> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT`.
> >>>>> + *
> >>>>> + * @header: The RkISP1 extensible parameters header, see
> >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> >>>>> + * @config: Filter configuration, see :c:type:`rkisp1_cif_isp_flt_config`
> >>>>> + */
> >>>>> +struct rkisp1_ext_params_flt_config {
> >>>>> +	struct rkisp1_ext_params_block_header header;
> >>>>> +	struct rkisp1_cif_isp_flt_config config;
> >>>>> +} __attribute__((aligned(8)));
> >>>>> +
> >>>>> +/**
> >>>>> + * struct rkisp1_ext_params_bdm_config - RkISP1 extensible params BDM config
> >>>>> + *
> >>>>> + * RkISP1 extensible parameters Demosaicing configuration block. Identified by
> >>>>> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM`.
> >>>>> + *
> >>>>> + * @header: The RkISP1 extensible parameters header, see
> >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> >>>>> + * @config: Demosaicing configuration, see :c:type:`rkisp1_cif_isp_bdm_config`
> >>>>> + */
> >>>>> +struct rkisp1_ext_params_bdm_config {
> >>>>> +	struct rkisp1_ext_params_block_header header;
> >>>>> +	struct rkisp1_cif_isp_bdm_config config;
> >>>>> +} __attribute__((aligned(8)));
> >>>>> +
> >>>>> +/**
> >>>>> + * struct rkisp1_ext_params_ctk_config - RkISP1 extensible params CTK config
> >>>>> + *
> >>>>> + * RkISP1 extensible parameters Cross-Talk configuration block. Identified by
> >>>>> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK`.
> >>>>> + *
> >>>>> + * @header: The RkISP1 extensible parameters header, see
> >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> >>>>> + * @config: Cross-Talk configuration, see :c:type:`rkisp1_cif_isp_ctk_config`
> >>>>> + */
> >>>>> +struct rkisp1_ext_params_ctk_config {
> >>>>> +	struct rkisp1_ext_params_block_header header;
> >>>>> +	struct rkisp1_cif_isp_ctk_config config;
> >>>>> +} __attribute__((aligned(8)));
> >>>>> +
> >>>>> +/**
> >>>>> + * struct rkisp1_ext_params_goc_config - RkISP1 extensible params GOC config
> >>>>> + *
> >>>>> + * RkISP1 extensible parameters Gamma-Out configuration block. Identified by
> >>>>> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC`.
> >>>>> + *
> >>>>> + * @header: The RkISP1 extensible parameters header, see
> >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> >>>>> + * @config: Gamma-Out configuration, see :c:type:`rkisp1_cif_isp_goc_config`
> >>>>> + */
> >>>>> +struct rkisp1_ext_params_goc_config {
> >>>>> +	struct rkisp1_ext_params_block_header header;
> >>>>> +	struct rkisp1_cif_isp_goc_config config;
> >>>>> +} __attribute__((aligned(8)));
> >>>>> +
> >>>>> +/**
> >>>>> + * struct rkisp1_ext_params_dpf_config - RkISP1 extensible params DPF config
> >>>>> + *
> >>>>> + * RkISP1 extensible parameters De-noise Pre-Filter configuration block.
> >>>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF`.
> >>>>> + *
> >>>>> + * @header: The RkISP1 extensible parameters header, see
> >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> >>>>> + * @config: De-noise Pre-Filter configuration, see
> >>>>> + *	    :c:type:`rkisp1_cif_isp_dpf_config`
> >>>>> + */
> >>>>> +struct rkisp1_ext_params_dpf_config {
> >>>>> +	struct rkisp1_ext_params_block_header header;
> >>>>> +	struct rkisp1_cif_isp_dpf_config config;
> >>>>> +} __attribute__((aligned(8)));
> >>>>> +
> >>>>> +/**
> >>>>> + * struct rkisp1_ext_params_dpf_strength_config - RkISP1 extensible params DPF
> >>>>> + *						  strength config
> >>>>> + *
> >>>>> + * RkISP1 extensible parameters De-noise Pre-Filter strength configuration
> >>>>> + * block. Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH`.
> >>>>> + *
> >>>>> + * @header: The RkISP1 extensible parameters header, see
> >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> >>>>> + * @config: De-noise Pre-Filter strength configuration, see
> >>>>> + *	    :c:type:`rkisp1_cif_isp_dpf_strength_config`
> >>>>> + */
> >>>>> +struct rkisp1_ext_params_dpf_strength_config {
> >>>>> +	struct rkisp1_ext_params_block_header header;
> >>>>> +	struct rkisp1_cif_isp_dpf_strength_config config;
> >>>>> +} __attribute__((aligned(8)));
> >>>>> +
> >>>>> +/**
> >>>>> + * struct rkisp1_ext_params_cproc_config - RkISP1 extensible params CPROC config
> >>>>> + *
> >>>>> + * RkISP1 extensible parameters Color Processing configuration block.
> >>>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC`.
> >>>>> + *
> >>>>> + * @header: The RkISP1 extensible parameters header, see
> >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> >>>>> + * @config: Color processing configuration, see
> >>>>> + *	    :c:type:`rkisp1_cif_isp_cproc_config`
> >>>>> + */
> >>>>> +struct rkisp1_ext_params_cproc_config {
> >>>>> +	struct rkisp1_ext_params_block_header header;
> >>>>> +	struct rkisp1_cif_isp_cproc_config config;
> >>>>> +} __attribute__((aligned(8)));
> >>>>> +
> >>>>> +/**
> >>>>> + * struct rkisp1_ext_params_ie_config - RkISP1 extensible params IE config
> >>>>> + *
> >>>>> + * RkISP1 extensible parameters Image Effect configuration block. Identified by
> >>>>> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_IE`.
> >>>>> + *
> >>>>> + * @header: The RkISP1 extensible parameters header, see
> >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> >>>>> + * @config: Image Effect configuration, see :c:type:`rkisp1_cif_isp_ie_config`
> >>>>> + */
> >>>>> +struct rkisp1_ext_params_ie_config {
> >>>>> +	struct rkisp1_ext_params_block_header header;
> >>>>> +	struct rkisp1_cif_isp_ie_config config;
> >>>>> +} __attribute__((aligned(8)));
> >>>>> +
> >>>>> +/**
> >>>>> + * struct rkisp1_ext_params_awb_meas_config - RkISP1 extensible params AWB
> >>>>> + *					      Meas config
> >>>>> + *
> >>>>> + * RkISP1 extensible parameters Auto-White Balance Measurement configuration
> >>>>> + * block. Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS`.
> >>>>> + *
> >>>>> + * @header: The RkISP1 extensible parameters header, see
> >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> >>>>> + * @config: Auto-White Balance measure configuration, see
> >>>>> + *	    :c:type:`rkisp1_cif_isp_awb_meas_config`
> >>>>> + */
> >>>>> +struct rkisp1_ext_params_awb_meas_config {
> >>>>> +	struct rkisp1_ext_params_block_header header;
> >>>>> +	struct rkisp1_cif_isp_awb_meas_config config;
> >>>>> +} __attribute__((aligned(8)));
> >>>>> +
> >>>>> +/**
> >>>>> + * struct rkisp1_ext_params_hst_config - RkISP1 extensible params Histogram config
> >>>>> + *
> >>>>> + * RkISP1 extensible parameters Histogram statistics configuration block.
> >>>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS`.
> >>>>> + *
> >>>>> + * @header: The RkISP1 extensible parameters header, see
> >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> >>>>> + * @config: Histogram statistics configuration, see
> >>>>> + *	    :c:type:`rkisp1_cif_isp_hst_config`
> >>>>> + */
> >>>>> +struct rkisp1_ext_params_hst_config {
> >>>>> +	struct rkisp1_ext_params_block_header header;
> >>>>> +	struct rkisp1_cif_isp_hst_config config;
> >>>>> +} __attribute__((aligned(8)));
> >>>>> +
> >>>>> +/**
> >>>>> + * struct rkisp1_ext_params_aec_config - RkISP1 extensible params AEC config
> >>>>> + *
> >>>>> + * RkISP1 extensible parameters Auto-Exposure statistics configuration block.
> >>>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS`.
> >>>>> + *
> >>>>> + * @header: The RkISP1 extensible parameters header, see
> >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> >>>>> + * @config: Auto-Exposure statistics configuration, see
> >>>>> + *	    :c:type:`rkisp1_cif_isp_aec_config`
> >>>>> + */
> >>>>> +struct rkisp1_ext_params_aec_config {
> >>>>> +	struct rkisp1_ext_params_block_header header;
> >>>>> +	struct rkisp1_cif_isp_aec_config config;
> >>>>> +} __attribute__((aligned(8)));
> >>>>> +
> >>>>> +/**
> >>>>> + * struct rkisp1_ext_params_afc_config - RkISP1 extensible params AFC config
> >>>>> + *
> >>>>> + * RkISP1 extensible parameters Auto-Focus statistics configuration block.
> >>>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS`.
> >>>>> + *
> >>>>> + * @header: The RkISP1 extensible parameters header, see
> >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> >>>>> + * @config: Auto-Focus statistics configuration, see
> >>>>> + *	    :c:type:`rkisp1_cif_isp_afc_config`
> >>>>> + */
> >>>>> +struct rkisp1_ext_params_afc_config {
> >>>>> +	struct rkisp1_ext_params_block_header header;
> >>>>> +	struct rkisp1_cif_isp_afc_config config;
> >>>>> +} __attribute__((aligned(8)));
> >>>>> +
> >>>>> +#define RKISP1_EXT_PARAMS_MAX_SIZE					\
> >>>>> +	(sizeof(struct rkisp1_ext_params_bls_config)			+\
> >>>>> +	sizeof(struct rkisp1_ext_params_dpcc_config)			+\
> >>>>> +	sizeof(struct rkisp1_ext_params_sdg_config)			+\
> >>>>> +	sizeof(struct rkisp1_ext_params_lsc_config)			+\
> >>>>> +	sizeof(struct rkisp1_ext_params_awb_gain_config)		+\
> >>>>> +	sizeof(struct rkisp1_ext_params_flt_config)			+\
> >>>>> +	sizeof(struct rkisp1_ext_params_bdm_config)			+\
> >>>>> +	sizeof(struct rkisp1_ext_params_ctk_config)			+\
> >>>>> +	sizeof(struct rkisp1_ext_params_goc_config)			+\
> >>>>> +	sizeof(struct rkisp1_ext_params_dpf_config)			+\
> >>>>> +	sizeof(struct rkisp1_ext_params_dpf_strength_config)		+\
> >>>>> +	sizeof(struct rkisp1_ext_params_cproc_config)			+\
> >>>>> +	sizeof(struct rkisp1_ext_params_ie_config)			+\
> >>>>> +	sizeof(struct rkisp1_ext_params_awb_meas_config)		+\
> >>>>> +	sizeof(struct rkisp1_ext_params_hst_config)			+\
> >>>>> +	sizeof(struct rkisp1_ext_params_aec_config)			+\
> >>>>> +	sizeof(struct rkisp1_ext_params_afc_config))
> >>>>> +
> >>>>> +/**
> >>>>> + * enum rksip1_ext_param_buffer_version - RkISP1 extensible parameters version
> >>>>> + *
> >>>>> + * @RKISP1_EXT_PARAM_BUFFER_V1: First version of RkISP1 extensible parameters
> >>>>> + */
> >>>>> +enum rksip1_ext_param_buffer_version {
> >>>>> +	RKISP1_EXT_PARAM_BUFFER_V1 = 1,
> >>>>> +};
> >>>>> +
> >>>>> +/**
> >>>>> + * struct rkisp1_ext_params_cfg - RkISP1 extensible parameters configuration
> >>>>> + *
> >>>>> + * This struct contains the configuration parameters of the RkISP1 ISP
> >>>>> + * algorithms, serialized by userspace into a data buffer. Each configuration
> >>>>> + * parameter block is represented by a block-specific structure which contains a
> >>>>> + * :c:type:`rkisp1_ext_params_block_header` entry as first member. Userspace
> >>>>> + * populates the @data buffer with configuration parameters for the blocks that
> >>>>> + * it intends to configure. As a consequence, the data buffer effective size
> >>>>> + * changes according to the number of ISP blocks that userspace intends to
> >>>>> + * configure and is set by userspace in the @data_size field.
> >>>>> + *
> >>>>> + * The parameters buffer is versioned by the @version field to allow modifying
> >>>>> + * and extending its definition. Userspace shall populate the @version field to
> >>>>> + * inform the driver about the version it intends to use. The driver will parse
> >>>>> + * and handle the @data buffer according to the data layout specific to the
> >>>>> + * indicated version and return an error if the desired version is not
> >>>>> + * supported.
> >>>>> + *
> >>>>> + * For each ISP block that userspace wants to configure, a block-specific
> >>>>> + * structure is appended to the @data buffer, one after the other without gaps
> >>>>> + * in between nor overlaps. Userspace shall populate the @data_size field with
> >>>>> + * the effective size, in bytes, of the @data buffer.
> >>>>> + *
> >>>>> + * The expected memory layout of the parameters buffer is::
> >>>>> + *
> >>>>> + *	+-------------------- struct rkisp1_ext_params_cfg -------------------+
> >>>>> + *	| version = RKISP_EXT_PARAMS_BUFFER_V1;                               |
> >>>>> + *	| data_size = sizeof(struct rkisp1_ext_params_bls_config)             |
> >>>>> + *	|           + sizeof(struct rkisp1_ext_params_dpcc_config);           |
> >>>>> + *	| +------------------------- data  ---------------------------------+ |
> >>>>> + *	| | +------------- struct rkisp1_ext_params_bls_config -----------+ | |
> >>>>> + *	| | | +-------- struct rkisp1_ext_params_block_header  ---------+ | | |
> >>>>> + *	| | | | type = RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS;                | | | |
> >>>>> + *	| | | | enable = RKISP1_EXT_PARAMS_BLOCK_ENABLE;                | | | |
> >>>>> + *	| | | | size = sizeof(struct rkisp1_ext_params_bls_config);     | | | |
> >>>>> + *	| | | +---------------------------------------------------------+ | | |
> >>>>> + *	| | | +---------- struct rkisp1_cif_isp_bls_config -------------+ | | |
> >>>>> + *	| | | | enable_auto = 0;                                        | | | |
> >>>>> + *	| | | | fixed_val.r = 256;                                      | | | |
> >>>>> + *	| | | | fixed_val.gr = 256;                                     | | | |
> >>>>> + *	| | | | fixed_val.gb = 256;                                     | | | |
> >>>>> + *	| | | | fixed_val.b = 256;                                      | | | |
> >>>>> + *	| | | +---------------------------------------------------------+ | | |
> >>>>> + *	| | +------------ struct rkisp1_ext_params_dpcc_config -----------+ | |
> >>>>> + *	| | | +-------- struct rkisp1_ext_params_block_header  ---------+ | | |
> >>>>> + *	| | | | type = RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC;               | | | |
> >>>>> + *	| | | | enable = RKISP1_EXT_PARAMS_BLOCK_ENABLE;                | | | |
> >>>>> + *	| | | | size = sizeof(struct rkisp1_ext_params_dpcc_config);    | | | |
> >>>>> + *	| | | +---------------------------------------------------------+ | | |
> >>>>> + *	| | | +---------- struct rkisp1_cif_isp_dpcc_config ------------+ | | |
> >>>>> + *	| | | | mode = RKISP1_CIF_ISP_DPCC_MODE_STAGE1_ENABLE;          | | | |
> >>>>> + *	| | | | output_mode =                                           | | | |
> >>>>> + *	| | | |   RKISP1_CIF_ISP_DPCC_OUTPUT_MODE_STAGE1_INCL_G_CENTER; | | | |
> >>>>> + *	| | | | set_use = ... ;                                         | | | |
> >>>>> + *	| | | | ...  = ... ;                                            | | | |
> >>>>> + *	| | | +---------------------------------------------------------+ | | |
> >>>>> + *	| | +-------------------------------------------------------------+ | |
> >>>>> + *	| +-----------------------------------------------------------------+ |
> >>>>> + *	+---------------------------------------------------------------------+
> >>>>> + *
> >>>>> + * @version: The RkISP1 extensible parameters buffer version, see
> >>>>> + *	     :c:type:`rksip1_ext_param_buffer_version`
> >>>>> + * @data_size: The RkISP1 configuration data effective size, excluding this
> >>>>> + *	       header
> >>>>> + * @data: The RkISP1 extensible configuration data blocks
> >>>>> + */
> >>>>> +struct rkisp1_ext_params_cfg {
> >>>>> +	__u32 version;
> >>>>> +	__u32 data_size;
> >>>>> +	__u8 data[RKISP1_EXT_PARAMS_MAX_SIZE];
> >>>>> +};
> >>>>> +
> >>>>>  #endif /* _UAPI_RKISP1_CONFIG_H */
> >>>
> >>
>
>

Re: [PATCH v7 01/12] media: uapi: rkisp1-config: Add extensible params format

[Laurent Pinchart]

On Tue, Aug 06, 2024 at 09:30:16AM +0200, Jacopo Mondi wrote:
> On Mon, Aug 05, 2024 at 11:52:29AM GMT, Sakari Ailus wrote:
> > On Tue, Jul 30, 2024 at 02:37:04PM +0200, Hans Verkuil wrote:
> > > On 30/07/2024 14:18, Laurent Pinchart wrote:
> > > > On Tue, Jul 30, 2024 at 02:11:12PM +0200, Hans Verkuil wrote:
> > > >> On 24/07/2024 10:49, Jacopo Mondi wrote:
> > > >>> Add to the rkisp1-config.h header data types and documentation of
> > > >>> the extensible parameters format.
> > > >>>
> > > >>> Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
> > > >>> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > > >>> Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
> > > >>> ---
> > > >>>  include/uapi/linux/rkisp1-config.h | 489 +++++++++++++++++++++++++++++
> > > >>>  1 file changed, 489 insertions(+)
> > > >>>
> > > >>> diff --git a/include/uapi/linux/rkisp1-config.h b/include/uapi/linux/rkisp1-config.h
> > > >>> index 6eeaf8bf2362..00b09c92cca7 100644
> > > >>> --- a/include/uapi/linux/rkisp1-config.h
> > > >>> +++ b/include/uapi/linux/rkisp1-config.h
> > > >>> @@ -996,4 +996,493 @@ struct rkisp1_stat_buffer {
> > > >>>  	struct rkisp1_cif_isp_stat params;
> > > >>>  };
> > > >>>
> > > >>> +/*---------- PART3: Extensible Configuration Parameters  ------------*/
> > > >>> +
> > > >>> +/**
> > > >>> + * enum rkisp1_ext_params_block_type - RkISP1 extensible params block type
> > > >>> + *
> > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS: Black level subtraction
> > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC: Defect pixel cluster correction
> > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG: Sensor de-gamma
> > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN: Auto white balance gains
> > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT: ISP filtering
> > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM: Bayer de-mosaic
> > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK: Cross-talk correction
> > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC: Gamma out correction
> > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF: De-noise pre-filter
> > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH: De-noise pre-filter strength
> > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC: Color processing
> > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_IE: Image effects
> > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC: Lens shading correction
> > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS: Auto white balance statistics
> > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS: Histogram statistics
> > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS: Auto exposure statistics
> > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS: Auto-focus statistics
> > > >>> + */
> > > >>> +enum rkisp1_ext_params_block_type {
> > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS,
> > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC,
> > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG,
> > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN,
> > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT,
> > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM,
> > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK,
> > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC,
> > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF,
> > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH,
> > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC,
> > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_IE,
> > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC,
> > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS,
> > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS,
> > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS,
> > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS,
> > > >>> +};
> > > >>> +
> > > >>> +/**
> > > >>> + * enum rkisp1_ext_params_block_enable - RkISP1 extensible parameter block
> > > >>> + *					 enable flags
> > > >>> + *
> > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_DISABLE: Disable the HW block
> > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_ENABLE: Enable the HW block
> > > >>> + */
> > > >>> +enum rkisp1_ext_params_block_enable {
> > > >>> +	RKISP1_EXT_PARAMS_BLOCK_DISABLE,
> > > >>> +	RKISP1_EXT_PARAMS_BLOCK_ENABLE,
> > > >>> +};
> > > >>> +
> > > >>> +/**
> > > >>> + * struct rkisp1_ext_params_block_header - RkISP1 extensible parameter block
> > > >>> + *					   header
> > > >>> + *
> > > >>> + * This structure represents the common part of all the ISP configuration
> > > >>> + * blocks. Each parameters block shall embed an instance of this structure type
> > > >>> + * as its first member, followed by the block-specific configuration data. The
> > > >>> + * driver inspects this common header to discern the block type and its size and
> > > >>> + * properly handle the block content by casting it to the correct block-specific
> > > >>> + * type.
> > > >>> + *
> > > >>> + * The @type field is one of the values enumerated by
> > > >>> + * :c:type:`rkisp1_ext_params_block_type` and specifies how the data should be
> > > >>> + * interpreted by the driver. The @size field specifies the size of the
> > > >>> + * parameters block and is used by the driver for validation purposes.
> > > >>> + *
> > > >>> + * The @enable field specifies the ISP block enablement state. The possible
> > > >>> + * enablement states are enumerated by :c:type:`rkisp1_ext_params_block_enable`.
> > > >>> + * When userspace needs to configure and enable an ISP block it shall fully
> > > >>> + * populate the block configuration and the @enable flag shall be set to
> > > >>> + * RKISP1_EXT_PARAMS_BLOCK_ENABLE. When userspace simply wants to disable the
> > > >>> + * ISP block the @enable flag shall be set to RKISP1_EXT_PARAMS_BLOCK_DISABLE.
> > > >>> + * The driver ignores the rest of the block configuration structure in this
> > > >>> + * case.
> > > >>> + *
> > > >>> + * If a new configuration of an ISP block has to be applied userspace shall
> > > >>> + * fully populate the ISP block configuration and set the @enable flag to
> > > >>> + * RKISP1_EXT_PARAMS_BLOCK_ENABLE.
> > > >>> + *
> > > >>> + * Userspace is responsible for correctly populating the parameters block header
> > > >>> + * fields (@type, @enable and @size) and the block-specific parameters.
> > > >>> + *
> > > >>> + * For example:
> > > >>> + *
> > > >>> + * .. code-block:: c
> > > >>> + *
> > > >>> + *	void populate_bls(struct rkisp1_ext_params_block_header *block) {
> > > >>> + *		struct rkisp1_ext_params_bls_config *bls =
> > > >>> + *			(struct rkisp1_ext_params_bls_config *)block;
> > > >>> + *
> > > >>> + *		bls->header.type = RKISP1_EXT_PARAMS_BLOCK_ID_BLS;
> > > >>> + *		bls->header.enable = RKISP1_EXT_PARAMS_BLOCK_ENABLE;
> > > >>> + *		bls->header.size = sizeof(*bls);
> > > >>> + *
> > > >>> + *		bls->config.enable_auto = 0;
> > > >>> + *		bls->config.fixed_val.r = blackLevelRed_;
> > > >>> + *		bls->config.fixed_val.gr = blackLevelGreenR_;
> > > >>> + *		bls->config.fixed_val.gb = blackLevelGreenB_;
> > > >>> + *		bls->config.fixed_val.b = blackLevelBlue_;
> > > >>> + *	}
> > > >>> + *
> > > >>> + * @type: The parameters block type, see
> > > >>> + *	  :c:type:`rkisp1_ext_params_block_type`
> > > >>> + * @enable: The block enable flag, see
> > > >>> + *	   :c:type:`rkisp1_ext_params_block_enable`
> > > >>> + * @size: Size (in bytes) of the parameters block, including this header
> > > >>> + */
> > > >>> +struct rkisp1_ext_params_block_header {
> > > >>> +	__u16 type;
> > > >>> +	__u16 enable;
> > > >>> +	__u16 size;
> > > >>
> > > >> I would suggest changing this to '__u32 size;'. It ensures the header is8 bytes
> > > >> long (much nicer than 6), and if there is ever a block > 65535, then it is supported.
> > > >
> > > > I'm pretty confident we will never need a block size larger than 64kB.
> > >
> > > Hmm, famous last words :-)
> > >
> > > > That would mean more than 64kB of data written to hardware
> > > > registers/SRAM for a single processing block, and it would be incredibly
> > > > expensive in terms of hardware. Keeping size a __u16 means we have two
> > > > bytes of reserved space we could possibly use later, which may come
> > > > handy.
> > >
> > > i would prefer to change the size to a u32, but rename the 'enable' field
> > > to 'flags', and assign bit 0 to the enable/disable bit. This is a bit
> > > more flexible IMHO and allows for 15 bits to encode additional data.
> > >
> > >  Blocks > 64kB could still be supported in the future by defining
> > > > a new version of the parameters format (RKISP1_EXT_PARAM_BUFFER_V2)
> > > > without needing a different 4CC.
> >
> > ...or making of use the existing padding. Shouldn't that be a reserved
> > field btw.?
> 
> I might have missed what padding to be made a reserved field you are
> referring to :)

The two bytes at the end of the structure, after the size field.

> > I'm fine either approach, perhaps leaning slightly towards u32 size.
> >
> > For the series:
> >
> > Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> >
> > > > This being said, the opposite argument can be made, that a 32-bit size
> > > > could come handy if we ever have larger blocks, and a new version of the
> > > > parameters format could be used if we ever need to add more fields to
> > > > the block header. I won't insist either way.
> > > >
> > > >> i wonder if, with this change, the 'aligned(8)' attributes are even needed, but
> > > >> I didn't dig into that.
> > > >
> > > > The header would become 8-bytes long, but its larger field would still
> > > > be 4-bytes long, so the compiler would only enforce 4-bytes aligned
> > > > AFAIK.
> > >
> > > Normally the actual data blocks (in the non-extensible format) are already aligned
> > > to either 4 or 8 bytes (depending on whether u64 values are used). So an 8 byte
> > > header won't mess up the alignment.

-- 
Regards,

Laurent Pinchart

Re: [PATCH v7 01/12] media: uapi: rkisp1-config: Add extensible params format

[Sakari Ailus]

Hi Jacopo,

On Tue, Aug 06, 2024 at 09:30:16AM +0200, Jacopo Mondi wrote:
> Hi Sakari
> 
> On Mon, Aug 05, 2024 at 11:52:29AM GMT, Sakari Ailus wrote:
> > Hi Hans, Laurent,
> >
> > On Tue, Jul 30, 2024 at 02:37:04PM +0200, Hans Verkuil wrote:
> > > On 30/07/2024 14:18, Laurent Pinchart wrote:
> > > > Hi Hans,
> > > >
> > > > On Tue, Jul 30, 2024 at 02:11:12PM +0200, Hans Verkuil wrote:
> > > >> On 24/07/2024 10:49, Jacopo Mondi wrote:
> > > >>> Add to the rkisp1-config.h header data types and documentation of
> > > >>> the extensible parameters format.
> > > >>>
> > > >>> Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
> > > >>> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > > >>> Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
> > > >>> ---
> > > >>>  include/uapi/linux/rkisp1-config.h | 489 +++++++++++++++++++++++++++++
> > > >>>  1 file changed, 489 insertions(+)
> > > >>>
> > > >>> diff --git a/include/uapi/linux/rkisp1-config.h b/include/uapi/linux/rkisp1-config.h
> > > >>> index 6eeaf8bf2362..00b09c92cca7 100644
> > > >>> --- a/include/uapi/linux/rkisp1-config.h
> > > >>> +++ b/include/uapi/linux/rkisp1-config.h
> > > >>> @@ -996,4 +996,493 @@ struct rkisp1_stat_buffer {
> > > >>>  	struct rkisp1_cif_isp_stat params;
> > > >>>  };
> > > >>>
> > > >>> +/*---------- PART3: Extensible Configuration Parameters  ------------*/
> > > >>> +
> > > >>> +/**
> > > >>> + * enum rkisp1_ext_params_block_type - RkISP1 extensible params block type
> > > >>> + *
> > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS: Black level subtraction
> > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC: Defect pixel cluster correction
> > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG: Sensor de-gamma
> > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN: Auto white balance gains
> > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT: ISP filtering
> > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM: Bayer de-mosaic
> > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK: Cross-talk correction
> > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC: Gamma out correction
> > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF: De-noise pre-filter
> > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH: De-noise pre-filter strength
> > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC: Color processing
> > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_IE: Image effects
> > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC: Lens shading correction
> > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS: Auto white balance statistics
> > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS: Histogram statistics
> > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS: Auto exposure statistics
> > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS: Auto-focus statistics
> > > >>> + */
> > > >>> +enum rkisp1_ext_params_block_type {
> > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS,
> > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC,
> > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG,
> > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN,
> > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT,
> > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM,
> > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK,
> > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC,
> > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF,
> > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH,
> > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC,
> > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_IE,
> > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC,
> > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS,
> > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS,
> > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS,
> > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS,
> > > >>> +};
> > > >>> +
> > > >>> +/**
> > > >>> + * enum rkisp1_ext_params_block_enable - RkISP1 extensible parameter block
> > > >>> + *					 enable flags
> > > >>> + *
> > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_DISABLE: Disable the HW block
> > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_ENABLE: Enable the HW block
> > > >>> + */
> > > >>> +enum rkisp1_ext_params_block_enable {
> > > >>> +	RKISP1_EXT_PARAMS_BLOCK_DISABLE,
> > > >>> +	RKISP1_EXT_PARAMS_BLOCK_ENABLE,
> > > >>> +};
> > > >>> +
> > > >>> +/**
> > > >>> + * struct rkisp1_ext_params_block_header - RkISP1 extensible parameter block
> > > >>> + *					   header
> > > >>> + *
> > > >>> + * This structure represents the common part of all the ISP configuration
> > > >>> + * blocks. Each parameters block shall embed an instance of this structure type
> > > >>> + * as its first member, followed by the block-specific configuration data. The
> > > >>> + * driver inspects this common header to discern the block type and its size and
> > > >>> + * properly handle the block content by casting it to the correct block-specific
> > > >>> + * type.
> > > >>> + *
> > > >>> + * The @type field is one of the values enumerated by
> > > >>> + * :c:type:`rkisp1_ext_params_block_type` and specifies how the data should be
> > > >>> + * interpreted by the driver. The @size field specifies the size of the
> > > >>> + * parameters block and is used by the driver for validation purposes.
> > > >>> + *
> > > >>> + * The @enable field specifies the ISP block enablement state. The possible
> > > >>> + * enablement states are enumerated by :c:type:`rkisp1_ext_params_block_enable`.
> > > >>> + * When userspace needs to configure and enable an ISP block it shall fully
> > > >>> + * populate the block configuration and the @enable flag shall be set to
> > > >>> + * RKISP1_EXT_PARAMS_BLOCK_ENABLE. When userspace simply wants to disable the
> > > >>> + * ISP block the @enable flag shall be set to RKISP1_EXT_PARAMS_BLOCK_DISABLE.
> > > >>> + * The driver ignores the rest of the block configuration structure in this
> > > >>> + * case.
> > > >>> + *
> > > >>> + * If a new configuration of an ISP block has to be applied userspace shall
> > > >>> + * fully populate the ISP block configuration and set the @enable flag to
> > > >>> + * RKISP1_EXT_PARAMS_BLOCK_ENABLE.
> > > >>> + *
> > > >>> + * Userspace is responsible for correctly populating the parameters block header
> > > >>> + * fields (@type, @enable and @size) and the block-specific parameters.
> > > >>> + *
> > > >>> + * For example:
> > > >>> + *
> > > >>> + * .. code-block:: c
> > > >>> + *
> > > >>> + *	void populate_bls(struct rkisp1_ext_params_block_header *block) {
> > > >>> + *		struct rkisp1_ext_params_bls_config *bls =
> > > >>> + *			(struct rkisp1_ext_params_bls_config *)block;
> > > >>> + *
> > > >>> + *		bls->header.type = RKISP1_EXT_PARAMS_BLOCK_ID_BLS;
> > > >>> + *		bls->header.enable = RKISP1_EXT_PARAMS_BLOCK_ENABLE;
> > > >>> + *		bls->header.size = sizeof(*bls);
> > > >>> + *
> > > >>> + *		bls->config.enable_auto = 0;
> > > >>> + *		bls->config.fixed_val.r = blackLevelRed_;
> > > >>> + *		bls->config.fixed_val.gr = blackLevelGreenR_;
> > > >>> + *		bls->config.fixed_val.gb = blackLevelGreenB_;
> > > >>> + *		bls->config.fixed_val.b = blackLevelBlue_;
> > > >>> + *	}
> > > >>> + *
> > > >>> + * @type: The parameters block type, see
> > > >>> + *	  :c:type:`rkisp1_ext_params_block_type`
> > > >>> + * @enable: The block enable flag, see
> > > >>> + *	   :c:type:`rkisp1_ext_params_block_enable`
> > > >>> + * @size: Size (in bytes) of the parameters block, including this header
> > > >>> + */
> > > >>> +struct rkisp1_ext_params_block_header {
> > > >>> +	__u16 type;
> > > >>> +	__u16 enable;
> > > >>> +	__u16 size;
> > > >>
> > > >> I would suggest changing this to '__u32 size;'. It ensures the header is8 bytes
> > > >> long (much nicer than 6), and if there is ever a block > 65535, then it is supported.
> > > >
> > > > I'm pretty confident we will never need a block size larger than 64kB.
> > >
> > > Hmm, famous last words :-)
> > >
> > > > That would mean more than 64kB of data written to hardware
> > > > registers/SRAM for a single processing block, and it would be incredibly
> > > > expensive in terms of hardware. Keeping size a __u16 means we have two
> > > > bytes of reserved space we could possibly use later, which may come
> > > > handy.
> > >
> > > i would prefer to change the size to a u32, but rename the 'enable' field
> > > to 'flags', and assign bit 0 to the enable/disable bit. This is a bit
> > > more flexible IMHO and allows for 15 bits to encode additional data.
> > >
> > >  Blocks > 64kB could still be supported in the future by defining
> > > > a new version of the parameters format (RKISP1_EXT_PARAM_BUFFER_V2)
> > > > without needing a different 4CC.
> >
> > ...or making of use the existing padding. Shouldn't that be a reserved
> > field btw.?
> >
> 
> I might have missed what padding to be made a reserved field you are
> referring to :)

Related to the struct being discussed, struct
rkisp1_ext_params_block_header? Due to the alignment, there's padding
there, isn't there?

> 
> > I'm fine either approach, perhaps leaning slightly towards u32 size.
> >
> > For the series:
> >
> > Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> >
> > > >
> > > > This being said, the opposite argument can be made, that a 32-bit size
> > > > could come handy if we ever have larger blocks, and a new version of the
> > > > parameters format could be used if we ever need to add more fields to
> > > > the block header. I won't insist either way.
> > > >
> > > >> i wonder if, with this change, the 'aligned(8)' attributes are even needed, but
> > > >> I didn't dig into that.
> > > >
> > > > The header would become 8-bytes long, but its larger field would still
> > > > be 4-bytes long, so the compiler would only enforce 4-bytes aligned
> > > > AFAIK.
> > >
> > > Normally the actual data blocks (in the non-extensible format) are already aligned
> > > to either 4 or 8 bytes (depending on whether u64 values are used). So an 8 byte
> > > header won't mess up the alignment.

-- 
Kind regards,

Sakari Ailus

Re: [PATCH v7 01/12] media: uapi: rkisp1-config: Add extensible params format

[Jacopo Mondi]

Hi Sakari

On Tue, Aug 06, 2024 at 08:53:13AM GMT, Sakari Ailus wrote:
> Hi Jacopo,
>
> On Tue, Aug 06, 2024 at 09:30:16AM +0200, Jacopo Mondi wrote:
> > Hi Sakari
> >
> > On Mon, Aug 05, 2024 at 11:52:29AM GMT, Sakari Ailus wrote:
> > > Hi Hans, Laurent,
> > >
> > > On Tue, Jul 30, 2024 at 02:37:04PM +0200, Hans Verkuil wrote:
> > > > On 30/07/2024 14:18, Laurent Pinchart wrote:
> > > > > Hi Hans,
> > > > >
> > > > > On Tue, Jul 30, 2024 at 02:11:12PM +0200, Hans Verkuil wrote:
> > > > >> On 24/07/2024 10:49, Jacopo Mondi wrote:
> > > > >>> Add to the rkisp1-config.h header data types and documentation of
> > > > >>> the extensible parameters format.
> > > > >>>
> > > > >>> Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
> > > > >>> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > > > >>> Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
> > > > >>> ---
> > > > >>>  include/uapi/linux/rkisp1-config.h | 489 +++++++++++++++++++++++++++++
> > > > >>>  1 file changed, 489 insertions(+)
> > > > >>>
> > > > >>> diff --git a/include/uapi/linux/rkisp1-config.h b/include/uapi/linux/rkisp1-config.h
> > > > >>> index 6eeaf8bf2362..00b09c92cca7 100644
> > > > >>> --- a/include/uapi/linux/rkisp1-config.h
> > > > >>> +++ b/include/uapi/linux/rkisp1-config.h
> > > > >>> @@ -996,4 +996,493 @@ struct rkisp1_stat_buffer {
> > > > >>>  	struct rkisp1_cif_isp_stat params;
> > > > >>>  };
> > > > >>>
> > > > >>> +/*---------- PART3: Extensible Configuration Parameters  ------------*/
> > > > >>> +
> > > > >>> +/**
> > > > >>> + * enum rkisp1_ext_params_block_type - RkISP1 extensible params block type
> > > > >>> + *
> > > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS: Black level subtraction
> > > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC: Defect pixel cluster correction
> > > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG: Sensor de-gamma
> > > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN: Auto white balance gains
> > > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT: ISP filtering
> > > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM: Bayer de-mosaic
> > > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK: Cross-talk correction
> > > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC: Gamma out correction
> > > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF: De-noise pre-filter
> > > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH: De-noise pre-filter strength
> > > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC: Color processing
> > > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_IE: Image effects
> > > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC: Lens shading correction
> > > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS: Auto white balance statistics
> > > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS: Histogram statistics
> > > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS: Auto exposure statistics
> > > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS: Auto-focus statistics
> > > > >>> + */
> > > > >>> +enum rkisp1_ext_params_block_type {
> > > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS,
> > > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC,
> > > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG,
> > > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN,
> > > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT,
> > > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM,
> > > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK,
> > > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC,
> > > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF,
> > > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH,
> > > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC,
> > > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_IE,
> > > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC,
> > > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS,
> > > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS,
> > > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS,
> > > > >>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS,
> > > > >>> +};
> > > > >>> +
> > > > >>> +/**
> > > > >>> + * enum rkisp1_ext_params_block_enable - RkISP1 extensible parameter block
> > > > >>> + *					 enable flags
> > > > >>> + *
> > > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_DISABLE: Disable the HW block
> > > > >>> + * @RKISP1_EXT_PARAMS_BLOCK_ENABLE: Enable the HW block
> > > > >>> + */
> > > > >>> +enum rkisp1_ext_params_block_enable {
> > > > >>> +	RKISP1_EXT_PARAMS_BLOCK_DISABLE,
> > > > >>> +	RKISP1_EXT_PARAMS_BLOCK_ENABLE,
> > > > >>> +};
> > > > >>> +
> > > > >>> +/**
> > > > >>> + * struct rkisp1_ext_params_block_header - RkISP1 extensible parameter block
> > > > >>> + *					   header
> > > > >>> + *
> > > > >>> + * This structure represents the common part of all the ISP configuration
> > > > >>> + * blocks. Each parameters block shall embed an instance of this structure type
> > > > >>> + * as its first member, followed by the block-specific configuration data. The
> > > > >>> + * driver inspects this common header to discern the block type and its size and
> > > > >>> + * properly handle the block content by casting it to the correct block-specific
> > > > >>> + * type.
> > > > >>> + *
> > > > >>> + * The @type field is one of the values enumerated by
> > > > >>> + * :c:type:`rkisp1_ext_params_block_type` and specifies how the data should be
> > > > >>> + * interpreted by the driver. The @size field specifies the size of the
> > > > >>> + * parameters block and is used by the driver for validation purposes.
> > > > >>> + *
> > > > >>> + * The @enable field specifies the ISP block enablement state. The possible
> > > > >>> + * enablement states are enumerated by :c:type:`rkisp1_ext_params_block_enable`.
> > > > >>> + * When userspace needs to configure and enable an ISP block it shall fully
> > > > >>> + * populate the block configuration and the @enable flag shall be set to
> > > > >>> + * RKISP1_EXT_PARAMS_BLOCK_ENABLE. When userspace simply wants to disable the
> > > > >>> + * ISP block the @enable flag shall be set to RKISP1_EXT_PARAMS_BLOCK_DISABLE.
> > > > >>> + * The driver ignores the rest of the block configuration structure in this
> > > > >>> + * case.
> > > > >>> + *
> > > > >>> + * If a new configuration of an ISP block has to be applied userspace shall
> > > > >>> + * fully populate the ISP block configuration and set the @enable flag to
> > > > >>> + * RKISP1_EXT_PARAMS_BLOCK_ENABLE.
> > > > >>> + *
> > > > >>> + * Userspace is responsible for correctly populating the parameters block header
> > > > >>> + * fields (@type, @enable and @size) and the block-specific parameters.
> > > > >>> + *
> > > > >>> + * For example:
> > > > >>> + *
> > > > >>> + * .. code-block:: c
> > > > >>> + *
> > > > >>> + *	void populate_bls(struct rkisp1_ext_params_block_header *block) {
> > > > >>> + *		struct rkisp1_ext_params_bls_config *bls =
> > > > >>> + *			(struct rkisp1_ext_params_bls_config *)block;
> > > > >>> + *
> > > > >>> + *		bls->header.type = RKISP1_EXT_PARAMS_BLOCK_ID_BLS;
> > > > >>> + *		bls->header.enable = RKISP1_EXT_PARAMS_BLOCK_ENABLE;
> > > > >>> + *		bls->header.size = sizeof(*bls);
> > > > >>> + *
> > > > >>> + *		bls->config.enable_auto = 0;
> > > > >>> + *		bls->config.fixed_val.r = blackLevelRed_;
> > > > >>> + *		bls->config.fixed_val.gr = blackLevelGreenR_;
> > > > >>> + *		bls->config.fixed_val.gb = blackLevelGreenB_;
> > > > >>> + *		bls->config.fixed_val.b = blackLevelBlue_;
> > > > >>> + *	}
> > > > >>> + *
> > > > >>> + * @type: The parameters block type, see
> > > > >>> + *	  :c:type:`rkisp1_ext_params_block_type`
> > > > >>> + * @enable: The block enable flag, see
> > > > >>> + *	   :c:type:`rkisp1_ext_params_block_enable`
> > > > >>> + * @size: Size (in bytes) of the parameters block, including this header
> > > > >>> + */
> > > > >>> +struct rkisp1_ext_params_block_header {
> > > > >>> +	__u16 type;
> > > > >>> +	__u16 enable;
> > > > >>> +	__u16 size;
> > > > >>
> > > > >> I would suggest changing this to '__u32 size;'. It ensures the header is8 bytes
> > > > >> long (much nicer than 6), and if there is ever a block > 65535, then it is supported.
> > > > >
> > > > > I'm pretty confident we will never need a block size larger than 64kB.
> > > >
> > > > Hmm, famous last words :-)
> > > >
> > > > > That would mean more than 64kB of data written to hardware
> > > > > registers/SRAM for a single processing block, and it would be incredibly
> > > > > expensive in terms of hardware. Keeping size a __u16 means we have two
> > > > > bytes of reserved space we could possibly use later, which may come
> > > > > handy.
> > > >
> > > > i would prefer to change the size to a u32, but rename the 'enable' field
> > > > to 'flags', and assign bit 0 to the enable/disable bit. This is a bit
> > > > more flexible IMHO and allows for 15 bits to encode additional data.
> > > >
> > > >  Blocks > 64kB could still be supported in the future by defining
> > > > > a new version of the parameters format (RKISP1_EXT_PARAM_BUFFER_V2)
> > > > > without needing a different 4CC.
> > >
> > > ...or making of use the existing padding. Shouldn't that be a reserved
> > > field btw.?
> > >
> >
> > I might have missed what padding to be made a reserved field you are
> > referring to :)
>
> Related to the struct being discussed, struct
> rkisp1_ext_params_block_header? Due to the alignment, there's padding
> there, isn't there?
>

Ah sorry, I assumed 'size' was going to be changed to be a u32, so
there won't be any padding.

> >
> > > I'm fine either approach, perhaps leaning slightly towards u32 size.

Ok, now that I read the two sentences as "either this or that" it
makes sense. I'm going for an u32 size then.

Thanks
  j

> > >
> > > For the series:
> > >
> > > Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> > >
> > > > >
> > > > > This being said, the opposite argument can be made, that a 32-bit size
> > > > > could come handy if we ever have larger blocks, and a new version of the
> > > > > parameters format could be used if we ever need to add more fields to
> > > > > the block header. I won't insist either way.
> > > > >
> > > > >> i wonder if, with this change, the 'aligned(8)' attributes are even needed, but
> > > > >> I didn't dig into that.
> > > > >
> > > > > The header would become 8-bytes long, but its larger field would still
> > > > > be 4-bytes long, so the compiler would only enforce 4-bytes aligned
> > > > > AFAIK.
> > > >
> > > > Normally the actual data blocks (in the non-extensible format) are already aligned
> > > > to either 4 or 8 bytes (depending on whether u64 values are used). So an 8 byte
> > > > header won't mess up the alignment.
>
> --
> Kind regards,
>
> Sakari Ailus

Re: [PATCH v7 01/12] media: uapi: rkisp1-config: Add extensible params format

[Laurent Pinchart]

On Tue, Aug 06, 2024 at 10:24:20AM +0200, Jacopo Mondi wrote:
> On Tue, Aug 06, 2024 at 10:17:02AM GMT, Hans Verkuil wrote:
> > On 06/08/2024 09:27, Jacopo Mondi wrote:
> > > On Tue, Jul 30, 2024 at 02:37:04PM GMT, Hans Verkuil wrote:
> > >> On 30/07/2024 14:18, Laurent Pinchart wrote:
> > >>> On Tue, Jul 30, 2024 at 02:11:12PM +0200, Hans Verkuil wrote:
> > >>>> On 24/07/2024 10:49, Jacopo Mondi wrote:
> > >>>>> Add to the rkisp1-config.h header data types and documentation of
> > >>>>> the extensible parameters format.
> > >>>>>
> > >>>>> Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
> > >>>>> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > >>>>> Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
> > >>>>> ---
> > >>>>>  include/uapi/linux/rkisp1-config.h | 489 +++++++++++++++++++++++++++++
> > >>>>>  1 file changed, 489 insertions(+)
> > >>>>>
> > >>>>> diff --git a/include/uapi/linux/rkisp1-config.h b/include/uapi/linux/rkisp1-config.h
> > >>>>> index 6eeaf8bf2362..00b09c92cca7 100644
> > >>>>> --- a/include/uapi/linux/rkisp1-config.h
> > >>>>> +++ b/include/uapi/linux/rkisp1-config.h
> > >>>>> @@ -996,4 +996,493 @@ struct rkisp1_stat_buffer {
> > >>>>>  	struct rkisp1_cif_isp_stat params;
> > >>>>>  };
> > >>>>>
> > >>>>> +/*---------- PART3: Extensible Configuration Parameters  ------------*/
> > >>>>> +
> > >>>>> +/**
> > >>>>> + * enum rkisp1_ext_params_block_type - RkISP1 extensible params block type
> > >>>>> + *
> > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS: Black level subtraction
> > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC: Defect pixel cluster correction
> > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG: Sensor de-gamma
> > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN: Auto white balance gains
> > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT: ISP filtering
> > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM: Bayer de-mosaic
> > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK: Cross-talk correction
> > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC: Gamma out correction
> > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF: De-noise pre-filter
> > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH: De-noise pre-filter strength
> > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC: Color processing
> > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_IE: Image effects
> > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC: Lens shading correction
> > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS: Auto white balance statistics
> > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS: Histogram statistics
> > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS: Auto exposure statistics
> > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS: Auto-focus statistics
> > >>>>> + */
> > >>>>> +enum rkisp1_ext_params_block_type {
> > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS,
> > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC,
> > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG,
> > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN,
> > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT,
> > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM,
> > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK,
> > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC,
> > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF,
> > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH,
> > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC,
> > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_IE,
> > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC,
> > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS,
> > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS,
> > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS,
> > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS,
> > >>>>> +};
> > >>>>> +
> > >>>>> +/**
> > >>>>> + * enum rkisp1_ext_params_block_enable - RkISP1 extensible parameter block
> > >>>>> + *					 enable flags
> > >>>>> + *
> > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_DISABLE: Disable the HW block
> > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_ENABLE: Enable the HW block
> > >>>>> + */
> > >>>>> +enum rkisp1_ext_params_block_enable {
> > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_DISABLE,
> > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_ENABLE,
> > >>>>> +};
> > >>>>> +
> > >>>>> +/**
> > >>>>> + * struct rkisp1_ext_params_block_header - RkISP1 extensible parameter block
> > >>>>> + *					   header
> > >>>>> + *
> > >>>>> + * This structure represents the common part of all the ISP configuration
> > >>>>> + * blocks. Each parameters block shall embed an instance of this structure type
> > >>>>> + * as its first member, followed by the block-specific configuration data. The
> > >>>>> + * driver inspects this common header to discern the block type and its size and
> > >>>>> + * properly handle the block content by casting it to the correct block-specific
> > >>>>> + * type.
> > >>>>> + *
> > >>>>> + * The @type field is one of the values enumerated by
> > >>>>> + * :c:type:`rkisp1_ext_params_block_type` and specifies how the data should be
> > >>>>> + * interpreted by the driver. The @size field specifies the size of the
> > >>>>> + * parameters block and is used by the driver for validation purposes.
> > >>>>> + *
> > >>>>> + * The @enable field specifies the ISP block enablement state. The possible
> > >>>>> + * enablement states are enumerated by :c:type:`rkisp1_ext_params_block_enable`.
> > >>>>> + * When userspace needs to configure and enable an ISP block it shall fully
> > >>>>> + * populate the block configuration and the @enable flag shall be set to
> > >>>>> + * RKISP1_EXT_PARAMS_BLOCK_ENABLE. When userspace simply wants to disable the
> > >>>>> + * ISP block the @enable flag shall be set to RKISP1_EXT_PARAMS_BLOCK_DISABLE.
> > >>>>> + * The driver ignores the rest of the block configuration structure in this
> > >>>>> + * case.
> > >>>>> + *
> > >>>>> + * If a new configuration of an ISP block has to be applied userspace shall
> > >>>>> + * fully populate the ISP block configuration and set the @enable flag to
> > >>>>> + * RKISP1_EXT_PARAMS_BLOCK_ENABLE.
> > >>>>> + *
> > >>>>> + * Userspace is responsible for correctly populating the parameters block header
> > >>>>> + * fields (@type, @enable and @size) and the block-specific parameters.
> > >>>>> + *
> > >>>>> + * For example:
> > >>>>> + *
> > >>>>> + * .. code-block:: c
> > >>>>> + *
> > >>>>> + *	void populate_bls(struct rkisp1_ext_params_block_header *block) {
> > >>>>> + *		struct rkisp1_ext_params_bls_config *bls =
> > >>>>> + *			(struct rkisp1_ext_params_bls_config *)block;
> > >>>>> + *
> > >>>>> + *		bls->header.type = RKISP1_EXT_PARAMS_BLOCK_ID_BLS;
> > >>>>> + *		bls->header.enable = RKISP1_EXT_PARAMS_BLOCK_ENABLE;
> > >>>>> + *		bls->header.size = sizeof(*bls);
> > >>>>> + *
> > >>>>> + *		bls->config.enable_auto = 0;
> > >>>>> + *		bls->config.fixed_val.r = blackLevelRed_;
> > >>>>> + *		bls->config.fixed_val.gr = blackLevelGreenR_;
> > >>>>> + *		bls->config.fixed_val.gb = blackLevelGreenB_;
> > >>>>> + *		bls->config.fixed_val.b = blackLevelBlue_;
> > >>>>> + *	}
> > >>>>> + *
> > >>>>> + * @type: The parameters block type, see
> > >>>>> + *	  :c:type:`rkisp1_ext_params_block_type`
> > >>>>> + * @enable: The block enable flag, see
> > >>>>> + *	   :c:type:`rkisp1_ext_params_block_enable`
> > >>>>> + * @size: Size (in bytes) of the parameters block, including this header
> > >>>>> + */
> > >>>>> +struct rkisp1_ext_params_block_header {
> > >>>>> +	__u16 type;
> > >>>>> +	__u16 enable;
> > >>>>> +	__u16 size;
> > >>>>
> > >>>> I would suggest changing this to '__u32 size;'. It ensures the header is8 bytes
> > >>>> long (much nicer than 6), and if there is ever a block > 65535, then it is supported.
> > >>>
> > >>> I'm pretty confident we will never need a block size larger than 64kB.
> > >>
> > >> Hmm, famous last words :-)
> > >>
> > >>> That would mean more than 64kB of data written to hardware
> > >>> registers/SRAM for a single processing block, and it would be incredibly
> > >>> expensive in terms of hardware. Keeping size a __u16 means we have two
> > >>> bytes of reserved space we could possibly use later, which may come
> > >>> handy.
> > >>
> > >> i would prefer to change the size to a u32, but rename the 'enable' field
> > >> to 'flags', and assign bit 0 to the enable/disable bit. This is a bit
> > >> more flexible IMHO and allows for 15 bits to encode additional data.
> > >>
> > >>  Blocks > 64kB could still be supported in the future by defining
> > >>> a new version of the parameters format (RKISP1_EXT_PARAM_BUFFER_V2)
> > >>> without needing a different 4CC.
> > >>>
> > >>> This being said, the opposite argument can be made, that a 32-bit size
> > >>> could come handy if we ever have larger blocks, and a new version of the
> > >>> parameters format could be used if we ever need to add more fields to
> > >>> the block header. I won't insist either way.
> > >>>
> > >>>> i wonder if, with this change, the 'aligned(8)' attributes are even needed, but
> > >>>> I didn't dig into that.
> > >>>
> > >>> The header would become 8-bytes long, but its larger field would still
> > >>> be 4-bytes long, so the compiler would only enforce 4-bytes aligned
> > >>> AFAIK.
> > >>
> > >> Normally the actual data blocks (in the non-extensible format) are already aligned
> > >> to either 4 or 8 bytes (depending on whether u64 values are used). So an 8 byte
> > >> header won't mess up the alignment.
> > >
> > > When it come to existing uAPI types (non-extensible) they sometimes
> > > have holes and are aligned by the compiler to the size of the
> > > largest-member, even when embedded in other structure. In example,
> > > cproc is 7 bytes in size
> > >
> > > struct rkisp1_cif_isp_cproc_config {
> > > 	__u8                       c_out_range;          /*     0     1 */
> > > 	__u8                       y_in_range;           /*     1     1 */
> > > 	__u8                       y_out_range;          /*     2     1 */
> > > 	__u8                       contrast;             /*     3     1 */
> > > 	__u8                       brightness;           /*     4     1 */
> > > 	__u8                       sat;                  /*     5     1 */
> > > 	__u8                       hue;                  /*     6     1 */
> > >
> > > 	/* size: 7, cachelines: 1, members: 7 */
> > > 	/* last cacheline: 7 bytes */
> > > };
> > >
> > > And when embedded in the corresponding extensible type it gets aligned
> > > to the size of the largest member in the structure (4 bytes)
> > > regardless if __attribute__((aligned(8)) is specified or not (by
> > > chance, in this case we get a size which is 8-bytes aligned)
> > >
> > > struct rkisp1_ext_params_cproc_config {
> > > 	struct rkisp1_ext_params_block_header header;    /*     0     8 */
> > > 	struct rkisp1_cif_isp_cproc_config config;       /*     8     7 */
> > >
> > > 	/* size: 16, cachelines: 1, members: 2 */
> > > 	/* padding: 1 */
> > > 	/* last cacheline: 16 bytes */
> > > };
> >
> > A potential problem with padding in a public data structure is that you
> > have to be careful that no memory is leaked in the padding data from the
> > kernel to userspace.
> 
> I agree with all the above, but keep in mind the above type is already
> part of the uAPI (the so-called FIXED format) and I cannot change it
> without changing the associated V4L2_META_FMT_RK_ISP1_PARAMS pixel format.
> 
> > Another potential problem is if e.g. rkisp1_cif_isp_cproc_config is extended
> > with a new byte in the future: in that case the new byte would replace the current
> > padding byte, but applications using the older struct may have left the
> > padding byte undefined, so the driver can't rely on that byte being 0
> > when called from such an application.
> 
> This can't happen with the existing fixed V4L2_META_FMT_RK_ISP1_PARAMS
> format. If the uAPI types change, a new pixel format would be
> needed. That's why we introduced the new extensible (and versioned) format :)
> 
> > For compound control (which have similar problems) I have quite strict
> > requirements: the structure layout may not contain any holes, and I require (and
> > test) that any reserved/padding fields at set to 0 by the driver and that it is
> > documented that userspace sets it to 0 as well.
> >
> > My recommendation for public APIs that effectively return data structures
> > is to:
> >
> > 1) ensure the layout is the same for 32 and 64 bit code,

Yes, that's very important.

> > 2) there are no holes, instead use reserved[] arrays instead,

Fine with me.

> > 3) ensure that reserved fields are always set to 0 by the driver,
> >    and document that userspace sets it to 0 as well. You could chose
> >    to test for that and fail if it is not 0.

In this case the fields are set by userspace, not by the driver.
Documenting that applications must set them to 0 is a good idea.

> > > Other structures are instead aligned to 4 bytes boundary without the
> > > aligned(8) attribute specified, in example BLS:
> > >
> > > struct rkisp1_ext_params_bls_config {
> > > 	struct rkisp1_ext_params_block_header header;    /*     0     8 */
> > > 	struct rkisp1_cif_isp_bls_config config;         /*     8    28 */
> > >
> > > 	/* XXX last struct has 1 hole */
> > >
> > > 	/* size: 36, cachelines: 1, members: 2 */
> > > 	/* member types with holes: 1, total: 1 */
> > > 	/* last cacheline: 36 bytes */
> > > };
> > >
> > > Which is not 8 bytes aligned, compared to the 40 bytes long aligned(8)
> > > version here below:
> > >
> > > struct rkisp1_ext_params_bls_config {
> > > 	struct rkisp1_ext_params_block_header header;    /*     0     8 */
> > > 	struct rkisp1_cif_isp_bls_config config;         /*     8    28 */
> > >
> > > 	/* XXX last struct has 1 hole */
> > >
> > > 	/* size: 40, cachelines: 1, members: 2 */
> > > 	/* padding: 4 */
> > > 	/* member types with holes: 1, total: 1 */
> > > 	/* last cacheline: 40 bytes */
> > > } __attribute__((__aligned__(8)));
> > >
> > > Now, the question is if we want 8 bytes alignment for all structures
> > > or not.
> > >
> > > 8-bytes alignment is significant when trying to read an 8-byte data
> > > type from a non-8-bytes-aligned address but as far as I can tell there
> > > are no u64 fields in the uAPI and the compiler would have aligned
> > > them anyway, so this is not a concern.
> > >
> > > When it comes to 32-bit compatibility (32 bits userspace running on a
> > > 64 bits kernel) I don't see any pointer in the uAPI whose size can
> > > change between a 32-bit and a 64-bit system, and all types have their
> > > size specified, so I don't think we would have any issue there.
> >
> > If there are no u64/s64 fields and no pointers, and you don't expect
> > to see such things in the future, then there is no need to align to
> > 8 bytes.

I'd rather not make assumptions on what we will or will not see in
future parameters blocks, and keep aligning all blocks to 8 bytes. I
don't see any drawback in doing so.

> > > The extensible data types are serialized in a u8[] data buffer, and
> > > code can access any location within the array by dereferencing a u64
> > > pointer, but there's nothing we can do to prevent this from happening.
> > >
> > > As of now, I'm missing the reason why we decided to align everything
> > > to 8 bytes..
> > >
> > >>>> Did you check with pahole for holes etc. in the datastructures?
> > >>>
> > >>> That's a good idea in any case.
> > >
> > > As shown in the above examples, existing types have holes, but there's
> > > nothing we can do about it. When embedded in the extensible types,
> > > after the 8-bytes header, they extensible type gets aligned to the
> > > size of the largest member, which is usually the 32-bits large (now
> > > that I made the size member of the header 32-bits).
> >
> > As mentioned above, I strongly suggest to replace holes with reserved
> > fields. It avoids potential future problems.
> 
> Agreed, but unfortunately I cannot change the existing types
> associated with V4L2_META_FMT_RK_ISP1_PARAMS..
> 
> > >>>>> +} __attribute__((aligned(8)));
> > >>>>> +
> > >>>>> +/**
> > >>>>> + * struct rkisp1_ext_params_bls_config - RkISP1 extensible params BLS config
> > >>>>> + *
> > >>>>> + * RkISP1 extensible parameters Black Level Subtraction configuration block.
> > >>>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS`.
> > >>>>> + *
> > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > >>>>> + * @config: Black Level Subtraction configuration, see
> > >>>>> + *	    :c:type:`rkisp1_cif_isp_bls_config`
> > >>>>> + */
> > >>>>> +struct rkisp1_ext_params_bls_config {
> > >>>>> +	struct rkisp1_ext_params_block_header header;
> > >>>>> +	struct rkisp1_cif_isp_bls_config config;
> > >>>>> +} __attribute__((aligned(8)));
> > >>>>> +
> > >>>>> +/**
> > >>>>> + * struct rkisp1_ext_params_dpcc_config - RkISP1 extensible params DPCC config
> > >>>>> + *
> > >>>>> + * RkISP1 extensible parameters Defective Pixel Cluster Correction configuration
> > >>>>> + * block. Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC`.
> > >>>>> + *
> > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > >>>>> + * @config: Defective Pixel Cluster Correction configuration, see
> > >>>>> + *	    :c:type:`rkisp1_cif_isp_dpcc_config`
> > >>>>> + */
> > >>>>> +struct rkisp1_ext_params_dpcc_config {
> > >>>>> +	struct rkisp1_ext_params_block_header header;
> > >>>>> +	struct rkisp1_cif_isp_dpcc_config config;
> > >>>>> +} __attribute__((aligned(8)));
> > >>>>> +
> > >>>>> +/**
> > >>>>> + * struct rkisp1_ext_params_sdg_config - RkISP1 extensible params SDG config
> > >>>>> + *
> > >>>>> + * RkISP1 extensible parameters Sensor Degamma configuration block. Identified
> > >>>>> + * by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG`.
> > >>>>> + *
> > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > >>>>> + * @config: Sensor Degamma configuration, see
> > >>>>> + *	    :c:type:`rkisp1_cif_isp_sdg_config`
> > >>>>> + */
> > >>>>> +struct rkisp1_ext_params_sdg_config {
> > >>>>> +	struct rkisp1_ext_params_block_header header;
> > >>>>> +	struct rkisp1_cif_isp_sdg_config config;
> > >>>>> +} __attribute__((aligned(8)));
> > >>>>> +
> > >>>>> +/**
> > >>>>> + * struct rkisp1_ext_params_lsc_config - RkISP1 extensible params LSC config
> > >>>>> + *
> > >>>>> + * RkISP1 extensible parameters Lens Shading Correction configuration block.
> > >>>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC`.
> > >>>>> + *
> > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > >>>>> + * @config: Lens Shading Correction configuration, see
> > >>>>> + *	    :c:type:`rkisp1_cif_isp_lsc_config`
> > >>>>> + */
> > >>>>> +struct rkisp1_ext_params_lsc_config {
> > >>>>> +	struct rkisp1_ext_params_block_header header;
> > >>>>> +	struct rkisp1_cif_isp_lsc_config config;
> > >>>>> +} __attribute__((aligned(8)));
> > >>>>> +
> > >>>>> +/**
> > >>>>> + * struct rkisp1_ext_params_awb_gain_config - RkISP1 extensible params AWB
> > >>>>> + *					      gain config
> > >>>>> + *
> > >>>>> + * RkISP1 extensible parameters Auto-White Balance Gains configuration block.
> > >>>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN`.
> > >>>>> + *
> > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > >>>>> + * @config: Auto-White Balance Gains configuration, see
> > >>>>> + *	    :c:type:`rkisp1_cif_isp_awb_gain_config`
> > >>>>> + */
> > >>>>> +struct rkisp1_ext_params_awb_gain_config {
> > >>>>> +	struct rkisp1_ext_params_block_header header;
> > >>>>> +	struct rkisp1_cif_isp_awb_gain_config config;
> > >>>>> +} __attribute__((aligned(8)));
> > >>>>> +
> > >>>>> +/**
> > >>>>> + * struct rkisp1_ext_params_flt_config - RkISP1 extensible params FLT config
> > >>>>> + *
> > >>>>> + * RkISP1 extensible parameters Filter configuration block. Identified by
> > >>>>> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT`.
> > >>>>> + *
> > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > >>>>> + * @config: Filter configuration, see :c:type:`rkisp1_cif_isp_flt_config`
> > >>>>> + */
> > >>>>> +struct rkisp1_ext_params_flt_config {
> > >>>>> +	struct rkisp1_ext_params_block_header header;
> > >>>>> +	struct rkisp1_cif_isp_flt_config config;
> > >>>>> +} __attribute__((aligned(8)));
> > >>>>> +
> > >>>>> +/**
> > >>>>> + * struct rkisp1_ext_params_bdm_config - RkISP1 extensible params BDM config
> > >>>>> + *
> > >>>>> + * RkISP1 extensible parameters Demosaicing configuration block. Identified by
> > >>>>> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM`.
> > >>>>> + *
> > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > >>>>> + * @config: Demosaicing configuration, see :c:type:`rkisp1_cif_isp_bdm_config`
> > >>>>> + */
> > >>>>> +struct rkisp1_ext_params_bdm_config {
> > >>>>> +	struct rkisp1_ext_params_block_header header;
> > >>>>> +	struct rkisp1_cif_isp_bdm_config config;
> > >>>>> +} __attribute__((aligned(8)));
> > >>>>> +
> > >>>>> +/**
> > >>>>> + * struct rkisp1_ext_params_ctk_config - RkISP1 extensible params CTK config
> > >>>>> + *
> > >>>>> + * RkISP1 extensible parameters Cross-Talk configuration block. Identified by
> > >>>>> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK`.
> > >>>>> + *
> > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > >>>>> + * @config: Cross-Talk configuration, see :c:type:`rkisp1_cif_isp_ctk_config`
> > >>>>> + */
> > >>>>> +struct rkisp1_ext_params_ctk_config {
> > >>>>> +	struct rkisp1_ext_params_block_header header;
> > >>>>> +	struct rkisp1_cif_isp_ctk_config config;
> > >>>>> +} __attribute__((aligned(8)));
> > >>>>> +
> > >>>>> +/**
> > >>>>> + * struct rkisp1_ext_params_goc_config - RkISP1 extensible params GOC config
> > >>>>> + *
> > >>>>> + * RkISP1 extensible parameters Gamma-Out configuration block. Identified by
> > >>>>> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC`.
> > >>>>> + *
> > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > >>>>> + * @config: Gamma-Out configuration, see :c:type:`rkisp1_cif_isp_goc_config`
> > >>>>> + */
> > >>>>> +struct rkisp1_ext_params_goc_config {
> > >>>>> +	struct rkisp1_ext_params_block_header header;
> > >>>>> +	struct rkisp1_cif_isp_goc_config config;
> > >>>>> +} __attribute__((aligned(8)));
> > >>>>> +
> > >>>>> +/**
> > >>>>> + * struct rkisp1_ext_params_dpf_config - RkISP1 extensible params DPF config
> > >>>>> + *
> > >>>>> + * RkISP1 extensible parameters De-noise Pre-Filter configuration block.
> > >>>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF`.
> > >>>>> + *
> > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > >>>>> + * @config: De-noise Pre-Filter configuration, see
> > >>>>> + *	    :c:type:`rkisp1_cif_isp_dpf_config`
> > >>>>> + */
> > >>>>> +struct rkisp1_ext_params_dpf_config {
> > >>>>> +	struct rkisp1_ext_params_block_header header;
> > >>>>> +	struct rkisp1_cif_isp_dpf_config config;
> > >>>>> +} __attribute__((aligned(8)));
> > >>>>> +
> > >>>>> +/**
> > >>>>> + * struct rkisp1_ext_params_dpf_strength_config - RkISP1 extensible params DPF
> > >>>>> + *						  strength config
> > >>>>> + *
> > >>>>> + * RkISP1 extensible parameters De-noise Pre-Filter strength configuration
> > >>>>> + * block. Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH`.
> > >>>>> + *
> > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > >>>>> + * @config: De-noise Pre-Filter strength configuration, see
> > >>>>> + *	    :c:type:`rkisp1_cif_isp_dpf_strength_config`
> > >>>>> + */
> > >>>>> +struct rkisp1_ext_params_dpf_strength_config {
> > >>>>> +	struct rkisp1_ext_params_block_header header;
> > >>>>> +	struct rkisp1_cif_isp_dpf_strength_config config;
> > >>>>> +} __attribute__((aligned(8)));
> > >>>>> +
> > >>>>> +/**
> > >>>>> + * struct rkisp1_ext_params_cproc_config - RkISP1 extensible params CPROC config
> > >>>>> + *
> > >>>>> + * RkISP1 extensible parameters Color Processing configuration block.
> > >>>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC`.
> > >>>>> + *
> > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > >>>>> + * @config: Color processing configuration, see
> > >>>>> + *	    :c:type:`rkisp1_cif_isp_cproc_config`
> > >>>>> + */
> > >>>>> +struct rkisp1_ext_params_cproc_config {
> > >>>>> +	struct rkisp1_ext_params_block_header header;
> > >>>>> +	struct rkisp1_cif_isp_cproc_config config;
> > >>>>> +} __attribute__((aligned(8)));
> > >>>>> +
> > >>>>> +/**
> > >>>>> + * struct rkisp1_ext_params_ie_config - RkISP1 extensible params IE config
> > >>>>> + *
> > >>>>> + * RkISP1 extensible parameters Image Effect configuration block. Identified by
> > >>>>> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_IE`.
> > >>>>> + *
> > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > >>>>> + * @config: Image Effect configuration, see :c:type:`rkisp1_cif_isp_ie_config`
> > >>>>> + */
> > >>>>> +struct rkisp1_ext_params_ie_config {
> > >>>>> +	struct rkisp1_ext_params_block_header header;
> > >>>>> +	struct rkisp1_cif_isp_ie_config config;
> > >>>>> +} __attribute__((aligned(8)));
> > >>>>> +
> > >>>>> +/**
> > >>>>> + * struct rkisp1_ext_params_awb_meas_config - RkISP1 extensible params AWB
> > >>>>> + *					      Meas config
> > >>>>> + *
> > >>>>> + * RkISP1 extensible parameters Auto-White Balance Measurement configuration
> > >>>>> + * block. Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS`.
> > >>>>> + *
> > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > >>>>> + * @config: Auto-White Balance measure configuration, see
> > >>>>> + *	    :c:type:`rkisp1_cif_isp_awb_meas_config`
> > >>>>> + */
> > >>>>> +struct rkisp1_ext_params_awb_meas_config {
> > >>>>> +	struct rkisp1_ext_params_block_header header;
> > >>>>> +	struct rkisp1_cif_isp_awb_meas_config config;
> > >>>>> +} __attribute__((aligned(8)));
> > >>>>> +
> > >>>>> +/**
> > >>>>> + * struct rkisp1_ext_params_hst_config - RkISP1 extensible params Histogram config
> > >>>>> + *
> > >>>>> + * RkISP1 extensible parameters Histogram statistics configuration block.
> > >>>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS`.
> > >>>>> + *
> > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > >>>>> + * @config: Histogram statistics configuration, see
> > >>>>> + *	    :c:type:`rkisp1_cif_isp_hst_config`
> > >>>>> + */
> > >>>>> +struct rkisp1_ext_params_hst_config {
> > >>>>> +	struct rkisp1_ext_params_block_header header;
> > >>>>> +	struct rkisp1_cif_isp_hst_config config;
> > >>>>> +} __attribute__((aligned(8)));
> > >>>>> +
> > >>>>> +/**
> > >>>>> + * struct rkisp1_ext_params_aec_config - RkISP1 extensible params AEC config
> > >>>>> + *
> > >>>>> + * RkISP1 extensible parameters Auto-Exposure statistics configuration block.
> > >>>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS`.
> > >>>>> + *
> > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > >>>>> + * @config: Auto-Exposure statistics configuration, see
> > >>>>> + *	    :c:type:`rkisp1_cif_isp_aec_config`
> > >>>>> + */
> > >>>>> +struct rkisp1_ext_params_aec_config {
> > >>>>> +	struct rkisp1_ext_params_block_header header;
> > >>>>> +	struct rkisp1_cif_isp_aec_config config;
> > >>>>> +} __attribute__((aligned(8)));
> > >>>>> +
> > >>>>> +/**
> > >>>>> + * struct rkisp1_ext_params_afc_config - RkISP1 extensible params AFC config
> > >>>>> + *
> > >>>>> + * RkISP1 extensible parameters Auto-Focus statistics configuration block.
> > >>>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS`.
> > >>>>> + *
> > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > >>>>> + * @config: Auto-Focus statistics configuration, see
> > >>>>> + *	    :c:type:`rkisp1_cif_isp_afc_config`
> > >>>>> + */
> > >>>>> +struct rkisp1_ext_params_afc_config {
> > >>>>> +	struct rkisp1_ext_params_block_header header;
> > >>>>> +	struct rkisp1_cif_isp_afc_config config;
> > >>>>> +} __attribute__((aligned(8)));
> > >>>>> +
> > >>>>> +#define RKISP1_EXT_PARAMS_MAX_SIZE					\
> > >>>>> +	(sizeof(struct rkisp1_ext_params_bls_config)			+\
> > >>>>> +	sizeof(struct rkisp1_ext_params_dpcc_config)			+\
> > >>>>> +	sizeof(struct rkisp1_ext_params_sdg_config)			+\
> > >>>>> +	sizeof(struct rkisp1_ext_params_lsc_config)			+\
> > >>>>> +	sizeof(struct rkisp1_ext_params_awb_gain_config)		+\
> > >>>>> +	sizeof(struct rkisp1_ext_params_flt_config)			+\
> > >>>>> +	sizeof(struct rkisp1_ext_params_bdm_config)			+\
> > >>>>> +	sizeof(struct rkisp1_ext_params_ctk_config)			+\
> > >>>>> +	sizeof(struct rkisp1_ext_params_goc_config)			+\
> > >>>>> +	sizeof(struct rkisp1_ext_params_dpf_config)			+\
> > >>>>> +	sizeof(struct rkisp1_ext_params_dpf_strength_config)		+\
> > >>>>> +	sizeof(struct rkisp1_ext_params_cproc_config)			+\
> > >>>>> +	sizeof(struct rkisp1_ext_params_ie_config)			+\
> > >>>>> +	sizeof(struct rkisp1_ext_params_awb_meas_config)		+\
> > >>>>> +	sizeof(struct rkisp1_ext_params_hst_config)			+\
> > >>>>> +	sizeof(struct rkisp1_ext_params_aec_config)			+\
> > >>>>> +	sizeof(struct rkisp1_ext_params_afc_config))
> > >>>>> +
> > >>>>> +/**
> > >>>>> + * enum rksip1_ext_param_buffer_version - RkISP1 extensible parameters version
> > >>>>> + *
> > >>>>> + * @RKISP1_EXT_PARAM_BUFFER_V1: First version of RkISP1 extensible parameters
> > >>>>> + */
> > >>>>> +enum rksip1_ext_param_buffer_version {
> > >>>>> +	RKISP1_EXT_PARAM_BUFFER_V1 = 1,
> > >>>>> +};
> > >>>>> +
> > >>>>> +/**
> > >>>>> + * struct rkisp1_ext_params_cfg - RkISP1 extensible parameters configuration
> > >>>>> + *
> > >>>>> + * This struct contains the configuration parameters of the RkISP1 ISP
> > >>>>> + * algorithms, serialized by userspace into a data buffer. Each configuration
> > >>>>> + * parameter block is represented by a block-specific structure which contains a
> > >>>>> + * :c:type:`rkisp1_ext_params_block_header` entry as first member. Userspace
> > >>>>> + * populates the @data buffer with configuration parameters for the blocks that
> > >>>>> + * it intends to configure. As a consequence, the data buffer effective size
> > >>>>> + * changes according to the number of ISP blocks that userspace intends to
> > >>>>> + * configure and is set by userspace in the @data_size field.
> > >>>>> + *
> > >>>>> + * The parameters buffer is versioned by the @version field to allow modifying
> > >>>>> + * and extending its definition. Userspace shall populate the @version field to
> > >>>>> + * inform the driver about the version it intends to use. The driver will parse
> > >>>>> + * and handle the @data buffer according to the data layout specific to the
> > >>>>> + * indicated version and return an error if the desired version is not
> > >>>>> + * supported.
> > >>>>> + *
> > >>>>> + * For each ISP block that userspace wants to configure, a block-specific
> > >>>>> + * structure is appended to the @data buffer, one after the other without gaps
> > >>>>> + * in between nor overlaps. Userspace shall populate the @data_size field with
> > >>>>> + * the effective size, in bytes, of the @data buffer.
> > >>>>> + *
> > >>>>> + * The expected memory layout of the parameters buffer is::
> > >>>>> + *
> > >>>>> + *	+-------------------- struct rkisp1_ext_params_cfg -------------------+
> > >>>>> + *	| version = RKISP_EXT_PARAMS_BUFFER_V1;                               |
> > >>>>> + *	| data_size = sizeof(struct rkisp1_ext_params_bls_config)             |
> > >>>>> + *	|           + sizeof(struct rkisp1_ext_params_dpcc_config);           |
> > >>>>> + *	| +------------------------- data  ---------------------------------+ |
> > >>>>> + *	| | +------------- struct rkisp1_ext_params_bls_config -----------+ | |
> > >>>>> + *	| | | +-------- struct rkisp1_ext_params_block_header  ---------+ | | |
> > >>>>> + *	| | | | type = RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS;                | | | |
> > >>>>> + *	| | | | enable = RKISP1_EXT_PARAMS_BLOCK_ENABLE;                | | | |
> > >>>>> + *	| | | | size = sizeof(struct rkisp1_ext_params_bls_config);     | | | |
> > >>>>> + *	| | | +---------------------------------------------------------+ | | |
> > >>>>> + *	| | | +---------- struct rkisp1_cif_isp_bls_config -------------+ | | |
> > >>>>> + *	| | | | enable_auto = 0;                                        | | | |
> > >>>>> + *	| | | | fixed_val.r = 256;                                      | | | |
> > >>>>> + *	| | | | fixed_val.gr = 256;                                     | | | |
> > >>>>> + *	| | | | fixed_val.gb = 256;                                     | | | |
> > >>>>> + *	| | | | fixed_val.b = 256;                                      | | | |
> > >>>>> + *	| | | +---------------------------------------------------------+ | | |
> > >>>>> + *	| | +------------ struct rkisp1_ext_params_dpcc_config -----------+ | |
> > >>>>> + *	| | | +-------- struct rkisp1_ext_params_block_header  ---------+ | | |
> > >>>>> + *	| | | | type = RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC;               | | | |
> > >>>>> + *	| | | | enable = RKISP1_EXT_PARAMS_BLOCK_ENABLE;                | | | |
> > >>>>> + *	| | | | size = sizeof(struct rkisp1_ext_params_dpcc_config);    | | | |
> > >>>>> + *	| | | +---------------------------------------------------------+ | | |
> > >>>>> + *	| | | +---------- struct rkisp1_cif_isp_dpcc_config ------------+ | | |
> > >>>>> + *	| | | | mode = RKISP1_CIF_ISP_DPCC_MODE_STAGE1_ENABLE;          | | | |
> > >>>>> + *	| | | | output_mode =                                           | | | |
> > >>>>> + *	| | | |   RKISP1_CIF_ISP_DPCC_OUTPUT_MODE_STAGE1_INCL_G_CENTER; | | | |
> > >>>>> + *	| | | | set_use = ... ;                                         | | | |
> > >>>>> + *	| | | | ...  = ... ;                                            | | | |
> > >>>>> + *	| | | +---------------------------------------------------------+ | | |
> > >>>>> + *	| | +-------------------------------------------------------------+ | |
> > >>>>> + *	| +-----------------------------------------------------------------+ |
> > >>>>> + *	+---------------------------------------------------------------------+
> > >>>>> + *
> > >>>>> + * @version: The RkISP1 extensible parameters buffer version, see
> > >>>>> + *	     :c:type:`rksip1_ext_param_buffer_version`
> > >>>>> + * @data_size: The RkISP1 configuration data effective size, excluding this
> > >>>>> + *	       header
> > >>>>> + * @data: The RkISP1 extensible configuration data blocks
> > >>>>> + */
> > >>>>> +struct rkisp1_ext_params_cfg {
> > >>>>> +	__u32 version;
> > >>>>> +	__u32 data_size;
> > >>>>> +	__u8 data[RKISP1_EXT_PARAMS_MAX_SIZE];
> > >>>>> +};
> > >>>>> +
> > >>>>>  #endif /* _UAPI_RKISP1_CONFIG_H */

-- 
Regards,

Laurent Pinchart

Re: [PATCH v7 01/12] media: uapi: rkisp1-config: Add extensible params format

[Jacopo Mondi]

Hi Laurent

On Tue, Aug 06, 2024 at 12:06:23PM GMT, Laurent Pinchart wrote:
> On Tue, Aug 06, 2024 at 10:24:20AM +0200, Jacopo Mondi wrote:
> > On Tue, Aug 06, 2024 at 10:17:02AM GMT, Hans Verkuil wrote:
> > > On 06/08/2024 09:27, Jacopo Mondi wrote:
> > > > On Tue, Jul 30, 2024 at 02:37:04PM GMT, Hans Verkuil wrote:
> > > >> On 30/07/2024 14:18, Laurent Pinchart wrote:
> > > >>> On Tue, Jul 30, 2024 at 02:11:12PM +0200, Hans Verkuil wrote:
> > > >>>> On 24/07/2024 10:49, Jacopo Mondi wrote:
> > > >>>>> Add to the rkisp1-config.h header data types and documentation of
> > > >>>>> the extensible parameters format.
> > > >>>>>
> > > >>>>> Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
> > > >>>>> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > > >>>>> Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
> > > >>>>> ---
> > > >>>>>  include/uapi/linux/rkisp1-config.h | 489 +++++++++++++++++++++++++++++
> > > >>>>>  1 file changed, 489 insertions(+)
> > > >>>>>
> > > >>>>> diff --git a/include/uapi/linux/rkisp1-config.h b/include/uapi/linux/rkisp1-config.h
> > > >>>>> index 6eeaf8bf2362..00b09c92cca7 100644
> > > >>>>> --- a/include/uapi/linux/rkisp1-config.h
> > > >>>>> +++ b/include/uapi/linux/rkisp1-config.h
> > > >>>>> @@ -996,4 +996,493 @@ struct rkisp1_stat_buffer {
> > > >>>>>  	struct rkisp1_cif_isp_stat params;
> > > >>>>>  };
> > > >>>>>
> > > >>>>> +/*---------- PART3: Extensible Configuration Parameters  ------------*/
> > > >>>>> +
> > > >>>>> +/**
> > > >>>>> + * enum rkisp1_ext_params_block_type - RkISP1 extensible params block type
> > > >>>>> + *
> > > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS: Black level subtraction
> > > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC: Defect pixel cluster correction
> > > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG: Sensor de-gamma
> > > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN: Auto white balance gains
> > > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT: ISP filtering
> > > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM: Bayer de-mosaic
> > > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK: Cross-talk correction
> > > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC: Gamma out correction
> > > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF: De-noise pre-filter
> > > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH: De-noise pre-filter strength
> > > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC: Color processing
> > > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_IE: Image effects
> > > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC: Lens shading correction
> > > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS: Auto white balance statistics
> > > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS: Histogram statistics
> > > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS: Auto exposure statistics
> > > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS: Auto-focus statistics
> > > >>>>> + */
> > > >>>>> +enum rkisp1_ext_params_block_type {
> > > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS,
> > > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC,
> > > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG,
> > > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN,
> > > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT,
> > > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM,
> > > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK,
> > > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC,
> > > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF,
> > > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH,
> > > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC,
> > > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_IE,
> > > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC,
> > > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS,
> > > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS,
> > > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS,
> > > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS,
> > > >>>>> +};
> > > >>>>> +
> > > >>>>> +/**
> > > >>>>> + * enum rkisp1_ext_params_block_enable - RkISP1 extensible parameter block
> > > >>>>> + *					 enable flags
> > > >>>>> + *
> > > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_DISABLE: Disable the HW block
> > > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_ENABLE: Enable the HW block
> > > >>>>> + */
> > > >>>>> +enum rkisp1_ext_params_block_enable {
> > > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_DISABLE,
> > > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_ENABLE,
> > > >>>>> +};
> > > >>>>> +
> > > >>>>> +/**
> > > >>>>> + * struct rkisp1_ext_params_block_header - RkISP1 extensible parameter block
> > > >>>>> + *					   header
> > > >>>>> + *
> > > >>>>> + * This structure represents the common part of all the ISP configuration
> > > >>>>> + * blocks. Each parameters block shall embed an instance of this structure type
> > > >>>>> + * as its first member, followed by the block-specific configuration data. The
> > > >>>>> + * driver inspects this common header to discern the block type and its size and
> > > >>>>> + * properly handle the block content by casting it to the correct block-specific
> > > >>>>> + * type.
> > > >>>>> + *
> > > >>>>> + * The @type field is one of the values enumerated by
> > > >>>>> + * :c:type:`rkisp1_ext_params_block_type` and specifies how the data should be
> > > >>>>> + * interpreted by the driver. The @size field specifies the size of the
> > > >>>>> + * parameters block and is used by the driver for validation purposes.
> > > >>>>> + *
> > > >>>>> + * The @enable field specifies the ISP block enablement state. The possible
> > > >>>>> + * enablement states are enumerated by :c:type:`rkisp1_ext_params_block_enable`.
> > > >>>>> + * When userspace needs to configure and enable an ISP block it shall fully
> > > >>>>> + * populate the block configuration and the @enable flag shall be set to
> > > >>>>> + * RKISP1_EXT_PARAMS_BLOCK_ENABLE. When userspace simply wants to disable the
> > > >>>>> + * ISP block the @enable flag shall be set to RKISP1_EXT_PARAMS_BLOCK_DISABLE.
> > > >>>>> + * The driver ignores the rest of the block configuration structure in this
> > > >>>>> + * case.
> > > >>>>> + *
> > > >>>>> + * If a new configuration of an ISP block has to be applied userspace shall
> > > >>>>> + * fully populate the ISP block configuration and set the @enable flag to
> > > >>>>> + * RKISP1_EXT_PARAMS_BLOCK_ENABLE.
> > > >>>>> + *
> > > >>>>> + * Userspace is responsible for correctly populating the parameters block header
> > > >>>>> + * fields (@type, @enable and @size) and the block-specific parameters.
> > > >>>>> + *
> > > >>>>> + * For example:
> > > >>>>> + *
> > > >>>>> + * .. code-block:: c
> > > >>>>> + *
> > > >>>>> + *	void populate_bls(struct rkisp1_ext_params_block_header *block) {
> > > >>>>> + *		struct rkisp1_ext_params_bls_config *bls =
> > > >>>>> + *			(struct rkisp1_ext_params_bls_config *)block;
> > > >>>>> + *
> > > >>>>> + *		bls->header.type = RKISP1_EXT_PARAMS_BLOCK_ID_BLS;
> > > >>>>> + *		bls->header.enable = RKISP1_EXT_PARAMS_BLOCK_ENABLE;
> > > >>>>> + *		bls->header.size = sizeof(*bls);
> > > >>>>> + *
> > > >>>>> + *		bls->config.enable_auto = 0;
> > > >>>>> + *		bls->config.fixed_val.r = blackLevelRed_;
> > > >>>>> + *		bls->config.fixed_val.gr = blackLevelGreenR_;
> > > >>>>> + *		bls->config.fixed_val.gb = blackLevelGreenB_;
> > > >>>>> + *		bls->config.fixed_val.b = blackLevelBlue_;
> > > >>>>> + *	}
> > > >>>>> + *
> > > >>>>> + * @type: The parameters block type, see
> > > >>>>> + *	  :c:type:`rkisp1_ext_params_block_type`
> > > >>>>> + * @enable: The block enable flag, see
> > > >>>>> + *	   :c:type:`rkisp1_ext_params_block_enable`
> > > >>>>> + * @size: Size (in bytes) of the parameters block, including this header
> > > >>>>> + */
> > > >>>>> +struct rkisp1_ext_params_block_header {
> > > >>>>> +	__u16 type;
> > > >>>>> +	__u16 enable;
> > > >>>>> +	__u16 size;
> > > >>>>
> > > >>>> I would suggest changing this to '__u32 size;'. It ensures the header is8 bytes
> > > >>>> long (much nicer than 6), and if there is ever a block > 65535, then it is supported.
> > > >>>
> > > >>> I'm pretty confident we will never need a block size larger than 64kB.
> > > >>
> > > >> Hmm, famous last words :-)
> > > >>
> > > >>> That would mean more than 64kB of data written to hardware
> > > >>> registers/SRAM for a single processing block, and it would be incredibly
> > > >>> expensive in terms of hardware. Keeping size a __u16 means we have two
> > > >>> bytes of reserved space we could possibly use later, which may come
> > > >>> handy.
> > > >>
> > > >> i would prefer to change the size to a u32, but rename the 'enable' field
> > > >> to 'flags', and assign bit 0 to the enable/disable bit. This is a bit
> > > >> more flexible IMHO and allows for 15 bits to encode additional data.
> > > >>
> > > >>  Blocks > 64kB could still be supported in the future by defining
> > > >>> a new version of the parameters format (RKISP1_EXT_PARAM_BUFFER_V2)
> > > >>> without needing a different 4CC.
> > > >>>
> > > >>> This being said, the opposite argument can be made, that a 32-bit size
> > > >>> could come handy if we ever have larger blocks, and a new version of the
> > > >>> parameters format could be used if we ever need to add more fields to
> > > >>> the block header. I won't insist either way.
> > > >>>
> > > >>>> i wonder if, with this change, the 'aligned(8)' attributes are even needed, but
> > > >>>> I didn't dig into that.
> > > >>>
> > > >>> The header would become 8-bytes long, but its larger field would still
> > > >>> be 4-bytes long, so the compiler would only enforce 4-bytes aligned
> > > >>> AFAIK.
> > > >>
> > > >> Normally the actual data blocks (in the non-extensible format) are already aligned
> > > >> to either 4 or 8 bytes (depending on whether u64 values are used). So an 8 byte
> > > >> header won't mess up the alignment.
> > > >
> > > > When it come to existing uAPI types (non-extensible) they sometimes
> > > > have holes and are aligned by the compiler to the size of the
> > > > largest-member, even when embedded in other structure. In example,
> > > > cproc is 7 bytes in size
> > > >
> > > > struct rkisp1_cif_isp_cproc_config {
> > > > 	__u8                       c_out_range;          /*     0     1 */
> > > > 	__u8                       y_in_range;           /*     1     1 */
> > > > 	__u8                       y_out_range;          /*     2     1 */
> > > > 	__u8                       contrast;             /*     3     1 */
> > > > 	__u8                       brightness;           /*     4     1 */
> > > > 	__u8                       sat;                  /*     5     1 */
> > > > 	__u8                       hue;                  /*     6     1 */
> > > >
> > > > 	/* size: 7, cachelines: 1, members: 7 */
> > > > 	/* last cacheline: 7 bytes */
> > > > };
> > > >
> > > > And when embedded in the corresponding extensible type it gets aligned
> > > > to the size of the largest member in the structure (4 bytes)
> > > > regardless if __attribute__((aligned(8)) is specified or not (by
> > > > chance, in this case we get a size which is 8-bytes aligned)
> > > >
> > > > struct rkisp1_ext_params_cproc_config {
> > > > 	struct rkisp1_ext_params_block_header header;    /*     0     8 */
> > > > 	struct rkisp1_cif_isp_cproc_config config;       /*     8     7 */
> > > >
> > > > 	/* size: 16, cachelines: 1, members: 2 */
> > > > 	/* padding: 1 */
> > > > 	/* last cacheline: 16 bytes */
> > > > };
> > >
> > > A potential problem with padding in a public data structure is that you
> > > have to be careful that no memory is leaked in the padding data from the
> > > kernel to userspace.
> >
> > I agree with all the above, but keep in mind the above type is already
> > part of the uAPI (the so-called FIXED format) and I cannot change it
> > without changing the associated V4L2_META_FMT_RK_ISP1_PARAMS pixel format.
> >
> > > Another potential problem is if e.g. rkisp1_cif_isp_cproc_config is extended
> > > with a new byte in the future: in that case the new byte would replace the current
> > > padding byte, but applications using the older struct may have left the
> > > padding byte undefined, so the driver can't rely on that byte being 0
> > > when called from such an application.
> >
> > This can't happen with the existing fixed V4L2_META_FMT_RK_ISP1_PARAMS
> > format. If the uAPI types change, a new pixel format would be
> > needed. That's why we introduced the new extensible (and versioned) format :)
> >
> > > For compound control (which have similar problems) I have quite strict
> > > requirements: the structure layout may not contain any holes, and I require (and
> > > test) that any reserved/padding fields at set to 0 by the driver and that it is
> > > documented that userspace sets it to 0 as well.
> > >
> > > My recommendation for public APIs that effectively return data structures
> > > is to:
> > >
> > > 1) ensure the layout is the same for 32 and 64 bit code,
>
> Yes, that's very important.
>
> > > 2) there are no holes, instead use reserved[] arrays instead,
>
> Fine with me.
>

Do we all agree I can't change the existing types, and we'll have to
live with holes ?

> > > 3) ensure that reserved fields are always set to 0 by the driver,
> > >    and document that userspace sets it to 0 as well. You could chose
> > >    to test for that and fail if it is not 0.
>
> In this case the fields are set by userspace, not by the driver.
> Documenting that applications must set them to 0 is a good idea.
>
> > > > Other structures are instead aligned to 4 bytes boundary without the
> > > > aligned(8) attribute specified, in example BLS:
> > > >
> > > > struct rkisp1_ext_params_bls_config {
> > > > 	struct rkisp1_ext_params_block_header header;    /*     0     8 */
> > > > 	struct rkisp1_cif_isp_bls_config config;         /*     8    28 */
> > > >
> > > > 	/* XXX last struct has 1 hole */
> > > >
> > > > 	/* size: 36, cachelines: 1, members: 2 */
> > > > 	/* member types with holes: 1, total: 1 */
> > > > 	/* last cacheline: 36 bytes */
> > > > };
> > > >
> > > > Which is not 8 bytes aligned, compared to the 40 bytes long aligned(8)
> > > > version here below:
> > > >
> > > > struct rkisp1_ext_params_bls_config {
> > > > 	struct rkisp1_ext_params_block_header header;    /*     0     8 */
> > > > 	struct rkisp1_cif_isp_bls_config config;         /*     8    28 */
> > > >
> > > > 	/* XXX last struct has 1 hole */
> > > >
> > > > 	/* size: 40, cachelines: 1, members: 2 */
> > > > 	/* padding: 4 */
> > > > 	/* member types with holes: 1, total: 1 */
> > > > 	/* last cacheline: 40 bytes */
> > > > } __attribute__((__aligned__(8)));
> > > >
> > > > Now, the question is if we want 8 bytes alignment for all structures
> > > > or not.
> > > >
> > > > 8-bytes alignment is significant when trying to read an 8-byte data
> > > > type from a non-8-bytes-aligned address but as far as I can tell there
> > > > are no u64 fields in the uAPI and the compiler would have aligned
> > > > them anyway, so this is not a concern.
> > > >
> > > > When it comes to 32-bit compatibility (32 bits userspace running on a
> > > > 64 bits kernel) I don't see any pointer in the uAPI whose size can
> > > > change between a 32-bit and a 64-bit system, and all types have their
> > > > size specified, so I don't think we would have any issue there.
> > >
> > > If there are no u64/s64 fields and no pointers, and you don't expect
> > > to see such things in the future, then there is no need to align to
> > > 8 bytes.
>
> I'd rather not make assumptions on what we will or will not see in
> future parameters blocks, and keep aligning all blocks to 8 bytes. I
> don't see any drawback in doing so.
>

A few extra bytes here and there, but I presume this won't make a big
difference. I agree with the better safe than sorry approach and I
will keep the aligned attribute.

> > > > The extensible data types are serialized in a u8[] data buffer, and
> > > > code can access any location within the array by dereferencing a u64
> > > > pointer, but there's nothing we can do to prevent this from happening.
> > > >
> > > > As of now, I'm missing the reason why we decided to align everything
> > > > to 8 bytes..
> > > >
> > > >>>> Did you check with pahole for holes etc. in the datastructures?
> > > >>>
> > > >>> That's a good idea in any case.
> > > >
> > > > As shown in the above examples, existing types have holes, but there's
> > > > nothing we can do about it. When embedded in the extensible types,
> > > > after the 8-bytes header, they extensible type gets aligned to the
> > > > size of the largest member, which is usually the 32-bits large (now
> > > > that I made the size member of the header 32-bits).
> > >
> > > As mentioned above, I strongly suggest to replace holes with reserved
> > > fields. It avoids potential future problems.
> >
> > Agreed, but unfortunately I cannot change the existing types
> > associated with V4L2_META_FMT_RK_ISP1_PARAMS..
> >
> > > >>>>> +} __attribute__((aligned(8)));
> > > >>>>> +
> > > >>>>> +/**
> > > >>>>> + * struct rkisp1_ext_params_bls_config - RkISP1 extensible params BLS config
> > > >>>>> + *
> > > >>>>> + * RkISP1 extensible parameters Black Level Subtraction configuration block.
> > > >>>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS`.
> > > >>>>> + *
> > > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > > >>>>> + * @config: Black Level Subtraction configuration, see
> > > >>>>> + *	    :c:type:`rkisp1_cif_isp_bls_config`
> > > >>>>> + */
> > > >>>>> +struct rkisp1_ext_params_bls_config {
> > > >>>>> +	struct rkisp1_ext_params_block_header header;
> > > >>>>> +	struct rkisp1_cif_isp_bls_config config;
> > > >>>>> +} __attribute__((aligned(8)));
> > > >>>>> +
> > > >>>>> +/**
> > > >>>>> + * struct rkisp1_ext_params_dpcc_config - RkISP1 extensible params DPCC config
> > > >>>>> + *
> > > >>>>> + * RkISP1 extensible parameters Defective Pixel Cluster Correction configuration
> > > >>>>> + * block. Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC`.
> > > >>>>> + *
> > > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > > >>>>> + * @config: Defective Pixel Cluster Correction configuration, see
> > > >>>>> + *	    :c:type:`rkisp1_cif_isp_dpcc_config`
> > > >>>>> + */
> > > >>>>> +struct rkisp1_ext_params_dpcc_config {
> > > >>>>> +	struct rkisp1_ext_params_block_header header;
> > > >>>>> +	struct rkisp1_cif_isp_dpcc_config config;
> > > >>>>> +} __attribute__((aligned(8)));
> > > >>>>> +
> > > >>>>> +/**
> > > >>>>> + * struct rkisp1_ext_params_sdg_config - RkISP1 extensible params SDG config
> > > >>>>> + *
> > > >>>>> + * RkISP1 extensible parameters Sensor Degamma configuration block. Identified
> > > >>>>> + * by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG`.
> > > >>>>> + *
> > > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > > >>>>> + * @config: Sensor Degamma configuration, see
> > > >>>>> + *	    :c:type:`rkisp1_cif_isp_sdg_config`
> > > >>>>> + */
> > > >>>>> +struct rkisp1_ext_params_sdg_config {
> > > >>>>> +	struct rkisp1_ext_params_block_header header;
> > > >>>>> +	struct rkisp1_cif_isp_sdg_config config;
> > > >>>>> +} __attribute__((aligned(8)));
> > > >>>>> +
> > > >>>>> +/**
> > > >>>>> + * struct rkisp1_ext_params_lsc_config - RkISP1 extensible params LSC config
> > > >>>>> + *
> > > >>>>> + * RkISP1 extensible parameters Lens Shading Correction configuration block.
> > > >>>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC`.
> > > >>>>> + *
> > > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > > >>>>> + * @config: Lens Shading Correction configuration, see
> > > >>>>> + *	    :c:type:`rkisp1_cif_isp_lsc_config`
> > > >>>>> + */
> > > >>>>> +struct rkisp1_ext_params_lsc_config {
> > > >>>>> +	struct rkisp1_ext_params_block_header header;
> > > >>>>> +	struct rkisp1_cif_isp_lsc_config config;
> > > >>>>> +} __attribute__((aligned(8)));
> > > >>>>> +
> > > >>>>> +/**
> > > >>>>> + * struct rkisp1_ext_params_awb_gain_config - RkISP1 extensible params AWB
> > > >>>>> + *					      gain config
> > > >>>>> + *
> > > >>>>> + * RkISP1 extensible parameters Auto-White Balance Gains configuration block.
> > > >>>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN`.
> > > >>>>> + *
> > > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > > >>>>> + * @config: Auto-White Balance Gains configuration, see
> > > >>>>> + *	    :c:type:`rkisp1_cif_isp_awb_gain_config`
> > > >>>>> + */
> > > >>>>> +struct rkisp1_ext_params_awb_gain_config {
> > > >>>>> +	struct rkisp1_ext_params_block_header header;
> > > >>>>> +	struct rkisp1_cif_isp_awb_gain_config config;
> > > >>>>> +} __attribute__((aligned(8)));
> > > >>>>> +
> > > >>>>> +/**
> > > >>>>> + * struct rkisp1_ext_params_flt_config - RkISP1 extensible params FLT config
> > > >>>>> + *
> > > >>>>> + * RkISP1 extensible parameters Filter configuration block. Identified by
> > > >>>>> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT`.
> > > >>>>> + *
> > > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > > >>>>> + * @config: Filter configuration, see :c:type:`rkisp1_cif_isp_flt_config`
> > > >>>>> + */
> > > >>>>> +struct rkisp1_ext_params_flt_config {
> > > >>>>> +	struct rkisp1_ext_params_block_header header;
> > > >>>>> +	struct rkisp1_cif_isp_flt_config config;
> > > >>>>> +} __attribute__((aligned(8)));
> > > >>>>> +
> > > >>>>> +/**
> > > >>>>> + * struct rkisp1_ext_params_bdm_config - RkISP1 extensible params BDM config
> > > >>>>> + *
> > > >>>>> + * RkISP1 extensible parameters Demosaicing configuration block. Identified by
> > > >>>>> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM`.
> > > >>>>> + *
> > > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > > >>>>> + * @config: Demosaicing configuration, see :c:type:`rkisp1_cif_isp_bdm_config`
> > > >>>>> + */
> > > >>>>> +struct rkisp1_ext_params_bdm_config {
> > > >>>>> +	struct rkisp1_ext_params_block_header header;
> > > >>>>> +	struct rkisp1_cif_isp_bdm_config config;
> > > >>>>> +} __attribute__((aligned(8)));
> > > >>>>> +
> > > >>>>> +/**
> > > >>>>> + * struct rkisp1_ext_params_ctk_config - RkISP1 extensible params CTK config
> > > >>>>> + *
> > > >>>>> + * RkISP1 extensible parameters Cross-Talk configuration block. Identified by
> > > >>>>> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK`.
> > > >>>>> + *
> > > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > > >>>>> + * @config: Cross-Talk configuration, see :c:type:`rkisp1_cif_isp_ctk_config`
> > > >>>>> + */
> > > >>>>> +struct rkisp1_ext_params_ctk_config {
> > > >>>>> +	struct rkisp1_ext_params_block_header header;
> > > >>>>> +	struct rkisp1_cif_isp_ctk_config config;
> > > >>>>> +} __attribute__((aligned(8)));
> > > >>>>> +
> > > >>>>> +/**
> > > >>>>> + * struct rkisp1_ext_params_goc_config - RkISP1 extensible params GOC config
> > > >>>>> + *
> > > >>>>> + * RkISP1 extensible parameters Gamma-Out configuration block. Identified by
> > > >>>>> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC`.
> > > >>>>> + *
> > > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > > >>>>> + * @config: Gamma-Out configuration, see :c:type:`rkisp1_cif_isp_goc_config`
> > > >>>>> + */
> > > >>>>> +struct rkisp1_ext_params_goc_config {
> > > >>>>> +	struct rkisp1_ext_params_block_header header;
> > > >>>>> +	struct rkisp1_cif_isp_goc_config config;
> > > >>>>> +} __attribute__((aligned(8)));
> > > >>>>> +
> > > >>>>> +/**
> > > >>>>> + * struct rkisp1_ext_params_dpf_config - RkISP1 extensible params DPF config
> > > >>>>> + *
> > > >>>>> + * RkISP1 extensible parameters De-noise Pre-Filter configuration block.
> > > >>>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF`.
> > > >>>>> + *
> > > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > > >>>>> + * @config: De-noise Pre-Filter configuration, see
> > > >>>>> + *	    :c:type:`rkisp1_cif_isp_dpf_config`
> > > >>>>> + */
> > > >>>>> +struct rkisp1_ext_params_dpf_config {
> > > >>>>> +	struct rkisp1_ext_params_block_header header;
> > > >>>>> +	struct rkisp1_cif_isp_dpf_config config;
> > > >>>>> +} __attribute__((aligned(8)));
> > > >>>>> +
> > > >>>>> +/**
> > > >>>>> + * struct rkisp1_ext_params_dpf_strength_config - RkISP1 extensible params DPF
> > > >>>>> + *						  strength config
> > > >>>>> + *
> > > >>>>> + * RkISP1 extensible parameters De-noise Pre-Filter strength configuration
> > > >>>>> + * block. Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH`.
> > > >>>>> + *
> > > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > > >>>>> + * @config: De-noise Pre-Filter strength configuration, see
> > > >>>>> + *	    :c:type:`rkisp1_cif_isp_dpf_strength_config`
> > > >>>>> + */
> > > >>>>> +struct rkisp1_ext_params_dpf_strength_config {
> > > >>>>> +	struct rkisp1_ext_params_block_header header;
> > > >>>>> +	struct rkisp1_cif_isp_dpf_strength_config config;
> > > >>>>> +} __attribute__((aligned(8)));
> > > >>>>> +
> > > >>>>> +/**
> > > >>>>> + * struct rkisp1_ext_params_cproc_config - RkISP1 extensible params CPROC config
> > > >>>>> + *
> > > >>>>> + * RkISP1 extensible parameters Color Processing configuration block.
> > > >>>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC`.
> > > >>>>> + *
> > > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > > >>>>> + * @config: Color processing configuration, see
> > > >>>>> + *	    :c:type:`rkisp1_cif_isp_cproc_config`
> > > >>>>> + */
> > > >>>>> +struct rkisp1_ext_params_cproc_config {
> > > >>>>> +	struct rkisp1_ext_params_block_header header;
> > > >>>>> +	struct rkisp1_cif_isp_cproc_config config;
> > > >>>>> +} __attribute__((aligned(8)));
> > > >>>>> +
> > > >>>>> +/**
> > > >>>>> + * struct rkisp1_ext_params_ie_config - RkISP1 extensible params IE config
> > > >>>>> + *
> > > >>>>> + * RkISP1 extensible parameters Image Effect configuration block. Identified by
> > > >>>>> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_IE`.
> > > >>>>> + *
> > > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > > >>>>> + * @config: Image Effect configuration, see :c:type:`rkisp1_cif_isp_ie_config`
> > > >>>>> + */
> > > >>>>> +struct rkisp1_ext_params_ie_config {
> > > >>>>> +	struct rkisp1_ext_params_block_header header;
> > > >>>>> +	struct rkisp1_cif_isp_ie_config config;
> > > >>>>> +} __attribute__((aligned(8)));
> > > >>>>> +
> > > >>>>> +/**
> > > >>>>> + * struct rkisp1_ext_params_awb_meas_config - RkISP1 extensible params AWB
> > > >>>>> + *					      Meas config
> > > >>>>> + *
> > > >>>>> + * RkISP1 extensible parameters Auto-White Balance Measurement configuration
> > > >>>>> + * block. Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS`.
> > > >>>>> + *
> > > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > > >>>>> + * @config: Auto-White Balance measure configuration, see
> > > >>>>> + *	    :c:type:`rkisp1_cif_isp_awb_meas_config`
> > > >>>>> + */
> > > >>>>> +struct rkisp1_ext_params_awb_meas_config {
> > > >>>>> +	struct rkisp1_ext_params_block_header header;
> > > >>>>> +	struct rkisp1_cif_isp_awb_meas_config config;
> > > >>>>> +} __attribute__((aligned(8)));
> > > >>>>> +
> > > >>>>> +/**
> > > >>>>> + * struct rkisp1_ext_params_hst_config - RkISP1 extensible params Histogram config
> > > >>>>> + *
> > > >>>>> + * RkISP1 extensible parameters Histogram statistics configuration block.
> > > >>>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS`.
> > > >>>>> + *
> > > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > > >>>>> + * @config: Histogram statistics configuration, see
> > > >>>>> + *	    :c:type:`rkisp1_cif_isp_hst_config`
> > > >>>>> + */
> > > >>>>> +struct rkisp1_ext_params_hst_config {
> > > >>>>> +	struct rkisp1_ext_params_block_header header;
> > > >>>>> +	struct rkisp1_cif_isp_hst_config config;
> > > >>>>> +} __attribute__((aligned(8)));
> > > >>>>> +
> > > >>>>> +/**
> > > >>>>> + * struct rkisp1_ext_params_aec_config - RkISP1 extensible params AEC config
> > > >>>>> + *
> > > >>>>> + * RkISP1 extensible parameters Auto-Exposure statistics configuration block.
> > > >>>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS`.
> > > >>>>> + *
> > > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > > >>>>> + * @config: Auto-Exposure statistics configuration, see
> > > >>>>> + *	    :c:type:`rkisp1_cif_isp_aec_config`
> > > >>>>> + */
> > > >>>>> +struct rkisp1_ext_params_aec_config {
> > > >>>>> +	struct rkisp1_ext_params_block_header header;
> > > >>>>> +	struct rkisp1_cif_isp_aec_config config;
> > > >>>>> +} __attribute__((aligned(8)));
> > > >>>>> +
> > > >>>>> +/**
> > > >>>>> + * struct rkisp1_ext_params_afc_config - RkISP1 extensible params AFC config
> > > >>>>> + *
> > > >>>>> + * RkISP1 extensible parameters Auto-Focus statistics configuration block.
> > > >>>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS`.
> > > >>>>> + *
> > > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > > >>>>> + * @config: Auto-Focus statistics configuration, see
> > > >>>>> + *	    :c:type:`rkisp1_cif_isp_afc_config`
> > > >>>>> + */
> > > >>>>> +struct rkisp1_ext_params_afc_config {
> > > >>>>> +	struct rkisp1_ext_params_block_header header;
> > > >>>>> +	struct rkisp1_cif_isp_afc_config config;
> > > >>>>> +} __attribute__((aligned(8)));
> > > >>>>> +
> > > >>>>> +#define RKISP1_EXT_PARAMS_MAX_SIZE					\
> > > >>>>> +	(sizeof(struct rkisp1_ext_params_bls_config)			+\
> > > >>>>> +	sizeof(struct rkisp1_ext_params_dpcc_config)			+\
> > > >>>>> +	sizeof(struct rkisp1_ext_params_sdg_config)			+\
> > > >>>>> +	sizeof(struct rkisp1_ext_params_lsc_config)			+\
> > > >>>>> +	sizeof(struct rkisp1_ext_params_awb_gain_config)		+\
> > > >>>>> +	sizeof(struct rkisp1_ext_params_flt_config)			+\
> > > >>>>> +	sizeof(struct rkisp1_ext_params_bdm_config)			+\
> > > >>>>> +	sizeof(struct rkisp1_ext_params_ctk_config)			+\
> > > >>>>> +	sizeof(struct rkisp1_ext_params_goc_config)			+\
> > > >>>>> +	sizeof(struct rkisp1_ext_params_dpf_config)			+\
> > > >>>>> +	sizeof(struct rkisp1_ext_params_dpf_strength_config)		+\
> > > >>>>> +	sizeof(struct rkisp1_ext_params_cproc_config)			+\
> > > >>>>> +	sizeof(struct rkisp1_ext_params_ie_config)			+\
> > > >>>>> +	sizeof(struct rkisp1_ext_params_awb_meas_config)		+\
> > > >>>>> +	sizeof(struct rkisp1_ext_params_hst_config)			+\
> > > >>>>> +	sizeof(struct rkisp1_ext_params_aec_config)			+\
> > > >>>>> +	sizeof(struct rkisp1_ext_params_afc_config))
> > > >>>>> +
> > > >>>>> +/**
> > > >>>>> + * enum rksip1_ext_param_buffer_version - RkISP1 extensible parameters version
> > > >>>>> + *
> > > >>>>> + * @RKISP1_EXT_PARAM_BUFFER_V1: First version of RkISP1 extensible parameters
> > > >>>>> + */
> > > >>>>> +enum rksip1_ext_param_buffer_version {
> > > >>>>> +	RKISP1_EXT_PARAM_BUFFER_V1 = 1,
> > > >>>>> +};
> > > >>>>> +
> > > >>>>> +/**
> > > >>>>> + * struct rkisp1_ext_params_cfg - RkISP1 extensible parameters configuration
> > > >>>>> + *
> > > >>>>> + * This struct contains the configuration parameters of the RkISP1 ISP
> > > >>>>> + * algorithms, serialized by userspace into a data buffer. Each configuration
> > > >>>>> + * parameter block is represented by a block-specific structure which contains a
> > > >>>>> + * :c:type:`rkisp1_ext_params_block_header` entry as first member. Userspace
> > > >>>>> + * populates the @data buffer with configuration parameters for the blocks that
> > > >>>>> + * it intends to configure. As a consequence, the data buffer effective size
> > > >>>>> + * changes according to the number of ISP blocks that userspace intends to
> > > >>>>> + * configure and is set by userspace in the @data_size field.
> > > >>>>> + *
> > > >>>>> + * The parameters buffer is versioned by the @version field to allow modifying
> > > >>>>> + * and extending its definition. Userspace shall populate the @version field to
> > > >>>>> + * inform the driver about the version it intends to use. The driver will parse
> > > >>>>> + * and handle the @data buffer according to the data layout specific to the
> > > >>>>> + * indicated version and return an error if the desired version is not
> > > >>>>> + * supported.
> > > >>>>> + *
> > > >>>>> + * For each ISP block that userspace wants to configure, a block-specific
> > > >>>>> + * structure is appended to the @data buffer, one after the other without gaps
> > > >>>>> + * in between nor overlaps. Userspace shall populate the @data_size field with
> > > >>>>> + * the effective size, in bytes, of the @data buffer.
> > > >>>>> + *
> > > >>>>> + * The expected memory layout of the parameters buffer is::
> > > >>>>> + *
> > > >>>>> + *	+-------------------- struct rkisp1_ext_params_cfg -------------------+
> > > >>>>> + *	| version = RKISP_EXT_PARAMS_BUFFER_V1;                               |
> > > >>>>> + *	| data_size = sizeof(struct rkisp1_ext_params_bls_config)             |
> > > >>>>> + *	|           + sizeof(struct rkisp1_ext_params_dpcc_config);           |
> > > >>>>> + *	| +------------------------- data  ---------------------------------+ |
> > > >>>>> + *	| | +------------- struct rkisp1_ext_params_bls_config -----------+ | |
> > > >>>>> + *	| | | +-------- struct rkisp1_ext_params_block_header  ---------+ | | |
> > > >>>>> + *	| | | | type = RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS;                | | | |
> > > >>>>> + *	| | | | enable = RKISP1_EXT_PARAMS_BLOCK_ENABLE;                | | | |
> > > >>>>> + *	| | | | size = sizeof(struct rkisp1_ext_params_bls_config);     | | | |
> > > >>>>> + *	| | | +---------------------------------------------------------+ | | |
> > > >>>>> + *	| | | +---------- struct rkisp1_cif_isp_bls_config -------------+ | | |
> > > >>>>> + *	| | | | enable_auto = 0;                                        | | | |
> > > >>>>> + *	| | | | fixed_val.r = 256;                                      | | | |
> > > >>>>> + *	| | | | fixed_val.gr = 256;                                     | | | |
> > > >>>>> + *	| | | | fixed_val.gb = 256;                                     | | | |
> > > >>>>> + *	| | | | fixed_val.b = 256;                                      | | | |
> > > >>>>> + *	| | | +---------------------------------------------------------+ | | |
> > > >>>>> + *	| | +------------ struct rkisp1_ext_params_dpcc_config -----------+ | |
> > > >>>>> + *	| | | +-------- struct rkisp1_ext_params_block_header  ---------+ | | |
> > > >>>>> + *	| | | | type = RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC;               | | | |
> > > >>>>> + *	| | | | enable = RKISP1_EXT_PARAMS_BLOCK_ENABLE;                | | | |
> > > >>>>> + *	| | | | size = sizeof(struct rkisp1_ext_params_dpcc_config);    | | | |
> > > >>>>> + *	| | | +---------------------------------------------------------+ | | |
> > > >>>>> + *	| | | +---------- struct rkisp1_cif_isp_dpcc_config ------------+ | | |
> > > >>>>> + *	| | | | mode = RKISP1_CIF_ISP_DPCC_MODE_STAGE1_ENABLE;          | | | |
> > > >>>>> + *	| | | | output_mode =                                           | | | |
> > > >>>>> + *	| | | |   RKISP1_CIF_ISP_DPCC_OUTPUT_MODE_STAGE1_INCL_G_CENTER; | | | |
> > > >>>>> + *	| | | | set_use = ... ;                                         | | | |
> > > >>>>> + *	| | | | ...  = ... ;                                            | | | |
> > > >>>>> + *	| | | +---------------------------------------------------------+ | | |
> > > >>>>> + *	| | +-------------------------------------------------------------+ | |
> > > >>>>> + *	| +-----------------------------------------------------------------+ |
> > > >>>>> + *	+---------------------------------------------------------------------+
> > > >>>>> + *
> > > >>>>> + * @version: The RkISP1 extensible parameters buffer version, see
> > > >>>>> + *	     :c:type:`rksip1_ext_param_buffer_version`
> > > >>>>> + * @data_size: The RkISP1 configuration data effective size, excluding this
> > > >>>>> + *	       header
> > > >>>>> + * @data: The RkISP1 extensible configuration data blocks
> > > >>>>> + */
> > > >>>>> +struct rkisp1_ext_params_cfg {
> > > >>>>> +	__u32 version;
> > > >>>>> +	__u32 data_size;
> > > >>>>> +	__u8 data[RKISP1_EXT_PARAMS_MAX_SIZE];
> > > >>>>> +};
> > > >>>>> +
> > > >>>>>  #endif /* _UAPI_RKISP1_CONFIG_H */
>
> --
> Regards,
>
> Laurent Pinchart

Re: [PATCH v7 01/12] media: uapi: rkisp1-config: Add extensible params format

[Laurent Pinchart]

On Tue, Aug 06, 2024 at 11:16:05AM +0200, Jacopo Mondi wrote:
> On Tue, Aug 06, 2024 at 12:06:23PM GMT, Laurent Pinchart wrote:
> > On Tue, Aug 06, 2024 at 10:24:20AM +0200, Jacopo Mondi wrote:
> > > On Tue, Aug 06, 2024 at 10:17:02AM GMT, Hans Verkuil wrote:
> > > > On 06/08/2024 09:27, Jacopo Mondi wrote:
> > > > > On Tue, Jul 30, 2024 at 02:37:04PM GMT, Hans Verkuil wrote:
> > > > >> On 30/07/2024 14:18, Laurent Pinchart wrote:
> > > > >>> On Tue, Jul 30, 2024 at 02:11:12PM +0200, Hans Verkuil wrote:
> > > > >>>> On 24/07/2024 10:49, Jacopo Mondi wrote:
> > > > >>>>> Add to the rkisp1-config.h header data types and documentation of
> > > > >>>>> the extensible parameters format.
> > > > >>>>>
> > > > >>>>> Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
> > > > >>>>> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > > > >>>>> Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
> > > > >>>>> ---
> > > > >>>>>  include/uapi/linux/rkisp1-config.h | 489 +++++++++++++++++++++++++++++
> > > > >>>>>  1 file changed, 489 insertions(+)
> > > > >>>>>
> > > > >>>>> diff --git a/include/uapi/linux/rkisp1-config.h b/include/uapi/linux/rkisp1-config.h
> > > > >>>>> index 6eeaf8bf2362..00b09c92cca7 100644
> > > > >>>>> --- a/include/uapi/linux/rkisp1-config.h
> > > > >>>>> +++ b/include/uapi/linux/rkisp1-config.h
> > > > >>>>> @@ -996,4 +996,493 @@ struct rkisp1_stat_buffer {
> > > > >>>>>  	struct rkisp1_cif_isp_stat params;
> > > > >>>>>  };
> > > > >>>>>
> > > > >>>>> +/*---------- PART3: Extensible Configuration Parameters  ------------*/
> > > > >>>>> +
> > > > >>>>> +/**
> > > > >>>>> + * enum rkisp1_ext_params_block_type - RkISP1 extensible params block type
> > > > >>>>> + *
> > > > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS: Black level subtraction
> > > > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC: Defect pixel cluster correction
> > > > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG: Sensor de-gamma
> > > > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN: Auto white balance gains
> > > > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT: ISP filtering
> > > > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM: Bayer de-mosaic
> > > > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK: Cross-talk correction
> > > > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC: Gamma out correction
> > > > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF: De-noise pre-filter
> > > > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH: De-noise pre-filter strength
> > > > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC: Color processing
> > > > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_IE: Image effects
> > > > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC: Lens shading correction
> > > > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS: Auto white balance statistics
> > > > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS: Histogram statistics
> > > > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS: Auto exposure statistics
> > > > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS: Auto-focus statistics
> > > > >>>>> + */
> > > > >>>>> +enum rkisp1_ext_params_block_type {
> > > > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS,
> > > > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC,
> > > > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG,
> > > > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN,
> > > > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT,
> > > > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM,
> > > > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK,
> > > > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC,
> > > > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF,
> > > > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH,
> > > > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC,
> > > > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_IE,
> > > > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC,
> > > > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS,
> > > > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS,
> > > > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS,
> > > > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS,
> > > > >>>>> +};
> > > > >>>>> +
> > > > >>>>> +/**
> > > > >>>>> + * enum rkisp1_ext_params_block_enable - RkISP1 extensible parameter block
> > > > >>>>> + *					 enable flags
> > > > >>>>> + *
> > > > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_DISABLE: Disable the HW block
> > > > >>>>> + * @RKISP1_EXT_PARAMS_BLOCK_ENABLE: Enable the HW block
> > > > >>>>> + */
> > > > >>>>> +enum rkisp1_ext_params_block_enable {
> > > > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_DISABLE,
> > > > >>>>> +	RKISP1_EXT_PARAMS_BLOCK_ENABLE,
> > > > >>>>> +};
> > > > >>>>> +
> > > > >>>>> +/**
> > > > >>>>> + * struct rkisp1_ext_params_block_header - RkISP1 extensible parameter block
> > > > >>>>> + *					   header
> > > > >>>>> + *
> > > > >>>>> + * This structure represents the common part of all the ISP configuration
> > > > >>>>> + * blocks. Each parameters block shall embed an instance of this structure type
> > > > >>>>> + * as its first member, followed by the block-specific configuration data. The
> > > > >>>>> + * driver inspects this common header to discern the block type and its size and
> > > > >>>>> + * properly handle the block content by casting it to the correct block-specific
> > > > >>>>> + * type.
> > > > >>>>> + *
> > > > >>>>> + * The @type field is one of the values enumerated by
> > > > >>>>> + * :c:type:`rkisp1_ext_params_block_type` and specifies how the data should be
> > > > >>>>> + * interpreted by the driver. The @size field specifies the size of the
> > > > >>>>> + * parameters block and is used by the driver for validation purposes.
> > > > >>>>> + *
> > > > >>>>> + * The @enable field specifies the ISP block enablement state. The possible
> > > > >>>>> + * enablement states are enumerated by :c:type:`rkisp1_ext_params_block_enable`.
> > > > >>>>> + * When userspace needs to configure and enable an ISP block it shall fully
> > > > >>>>> + * populate the block configuration and the @enable flag shall be set to
> > > > >>>>> + * RKISP1_EXT_PARAMS_BLOCK_ENABLE. When userspace simply wants to disable the
> > > > >>>>> + * ISP block the @enable flag shall be set to RKISP1_EXT_PARAMS_BLOCK_DISABLE.
> > > > >>>>> + * The driver ignores the rest of the block configuration structure in this
> > > > >>>>> + * case.
> > > > >>>>> + *
> > > > >>>>> + * If a new configuration of an ISP block has to be applied userspace shall
> > > > >>>>> + * fully populate the ISP block configuration and set the @enable flag to
> > > > >>>>> + * RKISP1_EXT_PARAMS_BLOCK_ENABLE.
> > > > >>>>> + *
> > > > >>>>> + * Userspace is responsible for correctly populating the parameters block header
> > > > >>>>> + * fields (@type, @enable and @size) and the block-specific parameters.
> > > > >>>>> + *
> > > > >>>>> + * For example:
> > > > >>>>> + *
> > > > >>>>> + * .. code-block:: c
> > > > >>>>> + *
> > > > >>>>> + *	void populate_bls(struct rkisp1_ext_params_block_header *block) {
> > > > >>>>> + *		struct rkisp1_ext_params_bls_config *bls =
> > > > >>>>> + *			(struct rkisp1_ext_params_bls_config *)block;
> > > > >>>>> + *
> > > > >>>>> + *		bls->header.type = RKISP1_EXT_PARAMS_BLOCK_ID_BLS;
> > > > >>>>> + *		bls->header.enable = RKISP1_EXT_PARAMS_BLOCK_ENABLE;
> > > > >>>>> + *		bls->header.size = sizeof(*bls);
> > > > >>>>> + *
> > > > >>>>> + *		bls->config.enable_auto = 0;
> > > > >>>>> + *		bls->config.fixed_val.r = blackLevelRed_;
> > > > >>>>> + *		bls->config.fixed_val.gr = blackLevelGreenR_;
> > > > >>>>> + *		bls->config.fixed_val.gb = blackLevelGreenB_;
> > > > >>>>> + *		bls->config.fixed_val.b = blackLevelBlue_;
> > > > >>>>> + *	}
> > > > >>>>> + *
> > > > >>>>> + * @type: The parameters block type, see
> > > > >>>>> + *	  :c:type:`rkisp1_ext_params_block_type`
> > > > >>>>> + * @enable: The block enable flag, see
> > > > >>>>> + *	   :c:type:`rkisp1_ext_params_block_enable`
> > > > >>>>> + * @size: Size (in bytes) of the parameters block, including this header
> > > > >>>>> + */
> > > > >>>>> +struct rkisp1_ext_params_block_header {
> > > > >>>>> +	__u16 type;
> > > > >>>>> +	__u16 enable;
> > > > >>>>> +	__u16 size;
> > > > >>>>
> > > > >>>> I would suggest changing this to '__u32 size;'. It ensures the header is8 bytes
> > > > >>>> long (much nicer than 6), and if there is ever a block > 65535, then it is supported.
> > > > >>>
> > > > >>> I'm pretty confident we will never need a block size larger than 64kB.
> > > > >>
> > > > >> Hmm, famous last words :-)
> > > > >>
> > > > >>> That would mean more than 64kB of data written to hardware
> > > > >>> registers/SRAM for a single processing block, and it would be incredibly
> > > > >>> expensive in terms of hardware. Keeping size a __u16 means we have two
> > > > >>> bytes of reserved space we could possibly use later, which may come
> > > > >>> handy.
> > > > >>
> > > > >> i would prefer to change the size to a u32, but rename the 'enable' field
> > > > >> to 'flags', and assign bit 0 to the enable/disable bit. This is a bit
> > > > >> more flexible IMHO and allows for 15 bits to encode additional data.
> > > > >>
> > > > >>  Blocks > 64kB could still be supported in the future by defining
> > > > >>> a new version of the parameters format (RKISP1_EXT_PARAM_BUFFER_V2)
> > > > >>> without needing a different 4CC.
> > > > >>>
> > > > >>> This being said, the opposite argument can be made, that a 32-bit size
> > > > >>> could come handy if we ever have larger blocks, and a new version of the
> > > > >>> parameters format could be used if we ever need to add more fields to
> > > > >>> the block header. I won't insist either way.
> > > > >>>
> > > > >>>> i wonder if, with this change, the 'aligned(8)' attributes are even needed, but
> > > > >>>> I didn't dig into that.
> > > > >>>
> > > > >>> The header would become 8-bytes long, but its larger field would still
> > > > >>> be 4-bytes long, so the compiler would only enforce 4-bytes aligned
> > > > >>> AFAIK.
> > > > >>
> > > > >> Normally the actual data blocks (in the non-extensible format) are already aligned
> > > > >> to either 4 or 8 bytes (depending on whether u64 values are used). So an 8 byte
> > > > >> header won't mess up the alignment.
> > > > >
> > > > > When it come to existing uAPI types (non-extensible) they sometimes
> > > > > have holes and are aligned by the compiler to the size of the
> > > > > largest-member, even when embedded in other structure. In example,
> > > > > cproc is 7 bytes in size
> > > > >
> > > > > struct rkisp1_cif_isp_cproc_config {
> > > > > 	__u8                       c_out_range;          /*     0     1 */
> > > > > 	__u8                       y_in_range;           /*     1     1 */
> > > > > 	__u8                       y_out_range;          /*     2     1 */
> > > > > 	__u8                       contrast;             /*     3     1 */
> > > > > 	__u8                       brightness;           /*     4     1 */
> > > > > 	__u8                       sat;                  /*     5     1 */
> > > > > 	__u8                       hue;                  /*     6     1 */
> > > > >
> > > > > 	/* size: 7, cachelines: 1, members: 7 */
> > > > > 	/* last cacheline: 7 bytes */
> > > > > };
> > > > >
> > > > > And when embedded in the corresponding extensible type it gets aligned
> > > > > to the size of the largest member in the structure (4 bytes)
> > > > > regardless if __attribute__((aligned(8)) is specified or not (by
> > > > > chance, in this case we get a size which is 8-bytes aligned)
> > > > >
> > > > > struct rkisp1_ext_params_cproc_config {
> > > > > 	struct rkisp1_ext_params_block_header header;    /*     0     8 */
> > > > > 	struct rkisp1_cif_isp_cproc_config config;       /*     8     7 */
> > > > >
> > > > > 	/* size: 16, cachelines: 1, members: 2 */
> > > > > 	/* padding: 1 */
> > > > > 	/* last cacheline: 16 bytes */
> > > > > };
> > > >
> > > > A potential problem with padding in a public data structure is that you
> > > > have to be careful that no memory is leaked in the padding data from the
> > > > kernel to userspace.
> > >
> > > I agree with all the above, but keep in mind the above type is already
> > > part of the uAPI (the so-called FIXED format) and I cannot change it
> > > without changing the associated V4L2_META_FMT_RK_ISP1_PARAMS pixel format.
> > >
> > > > Another potential problem is if e.g. rkisp1_cif_isp_cproc_config is extended
> > > > with a new byte in the future: in that case the new byte would replace the current
> > > > padding byte, but applications using the older struct may have left the
> > > > padding byte undefined, so the driver can't rely on that byte being 0
> > > > when called from such an application.
> > >
> > > This can't happen with the existing fixed V4L2_META_FMT_RK_ISP1_PARAMS
> > > format. If the uAPI types change, a new pixel format would be
> > > needed. That's why we introduced the new extensible (and versioned) format :)
> > >
> > > > For compound control (which have similar problems) I have quite strict
> > > > requirements: the structure layout may not contain any holes, and I require (and
> > > > test) that any reserved/padding fields at set to 0 by the driver and that it is
> > > > documented that userspace sets it to 0 as well.
> > > >
> > > > My recommendation for public APIs that effectively return data structures
> > > > is to:
> > > >
> > > > 1) ensure the layout is the same for 32 and 64 bit code,
> >
> > Yes, that's very important.
> >
> > > > 2) there are no holes, instead use reserved[] arrays instead,
> >
> > Fine with me.
> 
> Do we all agree I can't change the existing types, and we'll have to
> live with holes ?

We may be able to change the existing structures, but that would be a
separate patch, outside of the scope of this series.

> > > > 3) ensure that reserved fields are always set to 0 by the driver,
> > > >    and document that userspace sets it to 0 as well. You could chose
> > > >    to test for that and fail if it is not 0.
> >
> > In this case the fields are set by userspace, not by the driver.
> > Documenting that applications must set them to 0 is a good idea.
> >
> > > > > Other structures are instead aligned to 4 bytes boundary without the
> > > > > aligned(8) attribute specified, in example BLS:
> > > > >
> > > > > struct rkisp1_ext_params_bls_config {
> > > > > 	struct rkisp1_ext_params_block_header header;    /*     0     8 */
> > > > > 	struct rkisp1_cif_isp_bls_config config;         /*     8    28 */
> > > > >
> > > > > 	/* XXX last struct has 1 hole */
> > > > >
> > > > > 	/* size: 36, cachelines: 1, members: 2 */
> > > > > 	/* member types with holes: 1, total: 1 */
> > > > > 	/* last cacheline: 36 bytes */
> > > > > };
> > > > >
> > > > > Which is not 8 bytes aligned, compared to the 40 bytes long aligned(8)
> > > > > version here below:
> > > > >
> > > > > struct rkisp1_ext_params_bls_config {
> > > > > 	struct rkisp1_ext_params_block_header header;    /*     0     8 */
> > > > > 	struct rkisp1_cif_isp_bls_config config;         /*     8    28 */
> > > > >
> > > > > 	/* XXX last struct has 1 hole */
> > > > >
> > > > > 	/* size: 40, cachelines: 1, members: 2 */
> > > > > 	/* padding: 4 */
> > > > > 	/* member types with holes: 1, total: 1 */
> > > > > 	/* last cacheline: 40 bytes */
> > > > > } __attribute__((__aligned__(8)));
> > > > >
> > > > > Now, the question is if we want 8 bytes alignment for all structures
> > > > > or not.
> > > > >
> > > > > 8-bytes alignment is significant when trying to read an 8-byte data
> > > > > type from a non-8-bytes-aligned address but as far as I can tell there
> > > > > are no u64 fields in the uAPI and the compiler would have aligned
> > > > > them anyway, so this is not a concern.
> > > > >
> > > > > When it comes to 32-bit compatibility (32 bits userspace running on a
> > > > > 64 bits kernel) I don't see any pointer in the uAPI whose size can
> > > > > change between a 32-bit and a 64-bit system, and all types have their
> > > > > size specified, so I don't think we would have any issue there.
> > > >
> > > > If there are no u64/s64 fields and no pointers, and you don't expect
> > > > to see such things in the future, then there is no need to align to
> > > > 8 bytes.
> >
> > I'd rather not make assumptions on what we will or will not see in
> > future parameters blocks, and keep aligning all blocks to 8 bytes. I
> > don't see any drawback in doing so.
> 
> A few extra bytes here and there, but I presume this won't make a big
> difference. I agree with the better safe than sorry approach and I
> will keep the aligned attribute.
> 
> > > > > The extensible data types are serialized in a u8[] data buffer, and
> > > > > code can access any location within the array by dereferencing a u64
> > > > > pointer, but there's nothing we can do to prevent this from happening.
> > > > >
> > > > > As of now, I'm missing the reason why we decided to align everything
> > > > > to 8 bytes..
> > > > >
> > > > >>>> Did you check with pahole for holes etc. in the datastructures?
> > > > >>>
> > > > >>> That's a good idea in any case.
> > > > >
> > > > > As shown in the above examples, existing types have holes, but there's
> > > > > nothing we can do about it. When embedded in the extensible types,
> > > > > after the 8-bytes header, they extensible type gets aligned to the
> > > > > size of the largest member, which is usually the 32-bits large (now
> > > > > that I made the size member of the header 32-bits).
> > > >
> > > > As mentioned above, I strongly suggest to replace holes with reserved
> > > > fields. It avoids potential future problems.
> > >
> > > Agreed, but unfortunately I cannot change the existing types
> > > associated with V4L2_META_FMT_RK_ISP1_PARAMS..
> > >
> > > > >>>>> +} __attribute__((aligned(8)));
> > > > >>>>> +
> > > > >>>>> +/**
> > > > >>>>> + * struct rkisp1_ext_params_bls_config - RkISP1 extensible params BLS config
> > > > >>>>> + *
> > > > >>>>> + * RkISP1 extensible parameters Black Level Subtraction configuration block.
> > > > >>>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS`.
> > > > >>>>> + *
> > > > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > > > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > > > >>>>> + * @config: Black Level Subtraction configuration, see
> > > > >>>>> + *	    :c:type:`rkisp1_cif_isp_bls_config`
> > > > >>>>> + */
> > > > >>>>> +struct rkisp1_ext_params_bls_config {
> > > > >>>>> +	struct rkisp1_ext_params_block_header header;
> > > > >>>>> +	struct rkisp1_cif_isp_bls_config config;
> > > > >>>>> +} __attribute__((aligned(8)));
> > > > >>>>> +
> > > > >>>>> +/**
> > > > >>>>> + * struct rkisp1_ext_params_dpcc_config - RkISP1 extensible params DPCC config
> > > > >>>>> + *
> > > > >>>>> + * RkISP1 extensible parameters Defective Pixel Cluster Correction configuration
> > > > >>>>> + * block. Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC`.
> > > > >>>>> + *
> > > > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > > > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > > > >>>>> + * @config: Defective Pixel Cluster Correction configuration, see
> > > > >>>>> + *	    :c:type:`rkisp1_cif_isp_dpcc_config`
> > > > >>>>> + */
> > > > >>>>> +struct rkisp1_ext_params_dpcc_config {
> > > > >>>>> +	struct rkisp1_ext_params_block_header header;
> > > > >>>>> +	struct rkisp1_cif_isp_dpcc_config config;
> > > > >>>>> +} __attribute__((aligned(8)));
> > > > >>>>> +
> > > > >>>>> +/**
> > > > >>>>> + * struct rkisp1_ext_params_sdg_config - RkISP1 extensible params SDG config
> > > > >>>>> + *
> > > > >>>>> + * RkISP1 extensible parameters Sensor Degamma configuration block. Identified
> > > > >>>>> + * by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_SDG`.
> > > > >>>>> + *
> > > > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > > > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > > > >>>>> + * @config: Sensor Degamma configuration, see
> > > > >>>>> + *	    :c:type:`rkisp1_cif_isp_sdg_config`
> > > > >>>>> + */
> > > > >>>>> +struct rkisp1_ext_params_sdg_config {
> > > > >>>>> +	struct rkisp1_ext_params_block_header header;
> > > > >>>>> +	struct rkisp1_cif_isp_sdg_config config;
> > > > >>>>> +} __attribute__((aligned(8)));
> > > > >>>>> +
> > > > >>>>> +/**
> > > > >>>>> + * struct rkisp1_ext_params_lsc_config - RkISP1 extensible params LSC config
> > > > >>>>> + *
> > > > >>>>> + * RkISP1 extensible parameters Lens Shading Correction configuration block.
> > > > >>>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_LSC`.
> > > > >>>>> + *
> > > > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > > > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > > > >>>>> + * @config: Lens Shading Correction configuration, see
> > > > >>>>> + *	    :c:type:`rkisp1_cif_isp_lsc_config`
> > > > >>>>> + */
> > > > >>>>> +struct rkisp1_ext_params_lsc_config {
> > > > >>>>> +	struct rkisp1_ext_params_block_header header;
> > > > >>>>> +	struct rkisp1_cif_isp_lsc_config config;
> > > > >>>>> +} __attribute__((aligned(8)));
> > > > >>>>> +
> > > > >>>>> +/**
> > > > >>>>> + * struct rkisp1_ext_params_awb_gain_config - RkISP1 extensible params AWB
> > > > >>>>> + *					      gain config
> > > > >>>>> + *
> > > > >>>>> + * RkISP1 extensible parameters Auto-White Balance Gains configuration block.
> > > > >>>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_GAIN`.
> > > > >>>>> + *
> > > > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > > > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > > > >>>>> + * @config: Auto-White Balance Gains configuration, see
> > > > >>>>> + *	    :c:type:`rkisp1_cif_isp_awb_gain_config`
> > > > >>>>> + */
> > > > >>>>> +struct rkisp1_ext_params_awb_gain_config {
> > > > >>>>> +	struct rkisp1_ext_params_block_header header;
> > > > >>>>> +	struct rkisp1_cif_isp_awb_gain_config config;
> > > > >>>>> +} __attribute__((aligned(8)));
> > > > >>>>> +
> > > > >>>>> +/**
> > > > >>>>> + * struct rkisp1_ext_params_flt_config - RkISP1 extensible params FLT config
> > > > >>>>> + *
> > > > >>>>> + * RkISP1 extensible parameters Filter configuration block. Identified by
> > > > >>>>> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_FLT`.
> > > > >>>>> + *
> > > > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > > > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > > > >>>>> + * @config: Filter configuration, see :c:type:`rkisp1_cif_isp_flt_config`
> > > > >>>>> + */
> > > > >>>>> +struct rkisp1_ext_params_flt_config {
> > > > >>>>> +	struct rkisp1_ext_params_block_header header;
> > > > >>>>> +	struct rkisp1_cif_isp_flt_config config;
> > > > >>>>> +} __attribute__((aligned(8)));
> > > > >>>>> +
> > > > >>>>> +/**
> > > > >>>>> + * struct rkisp1_ext_params_bdm_config - RkISP1 extensible params BDM config
> > > > >>>>> + *
> > > > >>>>> + * RkISP1 extensible parameters Demosaicing configuration block. Identified by
> > > > >>>>> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_BDM`.
> > > > >>>>> + *
> > > > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > > > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > > > >>>>> + * @config: Demosaicing configuration, see :c:type:`rkisp1_cif_isp_bdm_config`
> > > > >>>>> + */
> > > > >>>>> +struct rkisp1_ext_params_bdm_config {
> > > > >>>>> +	struct rkisp1_ext_params_block_header header;
> > > > >>>>> +	struct rkisp1_cif_isp_bdm_config config;
> > > > >>>>> +} __attribute__((aligned(8)));
> > > > >>>>> +
> > > > >>>>> +/**
> > > > >>>>> + * struct rkisp1_ext_params_ctk_config - RkISP1 extensible params CTK config
> > > > >>>>> + *
> > > > >>>>> + * RkISP1 extensible parameters Cross-Talk configuration block. Identified by
> > > > >>>>> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_CTK`.
> > > > >>>>> + *
> > > > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > > > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > > > >>>>> + * @config: Cross-Talk configuration, see :c:type:`rkisp1_cif_isp_ctk_config`
> > > > >>>>> + */
> > > > >>>>> +struct rkisp1_ext_params_ctk_config {
> > > > >>>>> +	struct rkisp1_ext_params_block_header header;
> > > > >>>>> +	struct rkisp1_cif_isp_ctk_config config;
> > > > >>>>> +} __attribute__((aligned(8)));
> > > > >>>>> +
> > > > >>>>> +/**
> > > > >>>>> + * struct rkisp1_ext_params_goc_config - RkISP1 extensible params GOC config
> > > > >>>>> + *
> > > > >>>>> + * RkISP1 extensible parameters Gamma-Out configuration block. Identified by
> > > > >>>>> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_GOC`.
> > > > >>>>> + *
> > > > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > > > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > > > >>>>> + * @config: Gamma-Out configuration, see :c:type:`rkisp1_cif_isp_goc_config`
> > > > >>>>> + */
> > > > >>>>> +struct rkisp1_ext_params_goc_config {
> > > > >>>>> +	struct rkisp1_ext_params_block_header header;
> > > > >>>>> +	struct rkisp1_cif_isp_goc_config config;
> > > > >>>>> +} __attribute__((aligned(8)));
> > > > >>>>> +
> > > > >>>>> +/**
> > > > >>>>> + * struct rkisp1_ext_params_dpf_config - RkISP1 extensible params DPF config
> > > > >>>>> + *
> > > > >>>>> + * RkISP1 extensible parameters De-noise Pre-Filter configuration block.
> > > > >>>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF`.
> > > > >>>>> + *
> > > > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > > > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > > > >>>>> + * @config: De-noise Pre-Filter configuration, see
> > > > >>>>> + *	    :c:type:`rkisp1_cif_isp_dpf_config`
> > > > >>>>> + */
> > > > >>>>> +struct rkisp1_ext_params_dpf_config {
> > > > >>>>> +	struct rkisp1_ext_params_block_header header;
> > > > >>>>> +	struct rkisp1_cif_isp_dpf_config config;
> > > > >>>>> +} __attribute__((aligned(8)));
> > > > >>>>> +
> > > > >>>>> +/**
> > > > >>>>> + * struct rkisp1_ext_params_dpf_strength_config - RkISP1 extensible params DPF
> > > > >>>>> + *						  strength config
> > > > >>>>> + *
> > > > >>>>> + * RkISP1 extensible parameters De-noise Pre-Filter strength configuration
> > > > >>>>> + * block. Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_DPF_STRENGTH`.
> > > > >>>>> + *
> > > > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > > > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > > > >>>>> + * @config: De-noise Pre-Filter strength configuration, see
> > > > >>>>> + *	    :c:type:`rkisp1_cif_isp_dpf_strength_config`
> > > > >>>>> + */
> > > > >>>>> +struct rkisp1_ext_params_dpf_strength_config {
> > > > >>>>> +	struct rkisp1_ext_params_block_header header;
> > > > >>>>> +	struct rkisp1_cif_isp_dpf_strength_config config;
> > > > >>>>> +} __attribute__((aligned(8)));
> > > > >>>>> +
> > > > >>>>> +/**
> > > > >>>>> + * struct rkisp1_ext_params_cproc_config - RkISP1 extensible params CPROC config
> > > > >>>>> + *
> > > > >>>>> + * RkISP1 extensible parameters Color Processing configuration block.
> > > > >>>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_CPROC`.
> > > > >>>>> + *
> > > > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > > > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > > > >>>>> + * @config: Color processing configuration, see
> > > > >>>>> + *	    :c:type:`rkisp1_cif_isp_cproc_config`
> > > > >>>>> + */
> > > > >>>>> +struct rkisp1_ext_params_cproc_config {
> > > > >>>>> +	struct rkisp1_ext_params_block_header header;
> > > > >>>>> +	struct rkisp1_cif_isp_cproc_config config;
> > > > >>>>> +} __attribute__((aligned(8)));
> > > > >>>>> +
> > > > >>>>> +/**
> > > > >>>>> + * struct rkisp1_ext_params_ie_config - RkISP1 extensible params IE config
> > > > >>>>> + *
> > > > >>>>> + * RkISP1 extensible parameters Image Effect configuration block. Identified by
> > > > >>>>> + * :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_IE`.
> > > > >>>>> + *
> > > > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > > > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > > > >>>>> + * @config: Image Effect configuration, see :c:type:`rkisp1_cif_isp_ie_config`
> > > > >>>>> + */
> > > > >>>>> +struct rkisp1_ext_params_ie_config {
> > > > >>>>> +	struct rkisp1_ext_params_block_header header;
> > > > >>>>> +	struct rkisp1_cif_isp_ie_config config;
> > > > >>>>> +} __attribute__((aligned(8)));
> > > > >>>>> +
> > > > >>>>> +/**
> > > > >>>>> + * struct rkisp1_ext_params_awb_meas_config - RkISP1 extensible params AWB
> > > > >>>>> + *					      Meas config
> > > > >>>>> + *
> > > > >>>>> + * RkISP1 extensible parameters Auto-White Balance Measurement configuration
> > > > >>>>> + * block. Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AWB_MEAS`.
> > > > >>>>> + *
> > > > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > > > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > > > >>>>> + * @config: Auto-White Balance measure configuration, see
> > > > >>>>> + *	    :c:type:`rkisp1_cif_isp_awb_meas_config`
> > > > >>>>> + */
> > > > >>>>> +struct rkisp1_ext_params_awb_meas_config {
> > > > >>>>> +	struct rkisp1_ext_params_block_header header;
> > > > >>>>> +	struct rkisp1_cif_isp_awb_meas_config config;
> > > > >>>>> +} __attribute__((aligned(8)));
> > > > >>>>> +
> > > > >>>>> +/**
> > > > >>>>> + * struct rkisp1_ext_params_hst_config - RkISP1 extensible params Histogram config
> > > > >>>>> + *
> > > > >>>>> + * RkISP1 extensible parameters Histogram statistics configuration block.
> > > > >>>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_HST_MEAS`.
> > > > >>>>> + *
> > > > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > > > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > > > >>>>> + * @config: Histogram statistics configuration, see
> > > > >>>>> + *	    :c:type:`rkisp1_cif_isp_hst_config`
> > > > >>>>> + */
> > > > >>>>> +struct rkisp1_ext_params_hst_config {
> > > > >>>>> +	struct rkisp1_ext_params_block_header header;
> > > > >>>>> +	struct rkisp1_cif_isp_hst_config config;
> > > > >>>>> +} __attribute__((aligned(8)));
> > > > >>>>> +
> > > > >>>>> +/**
> > > > >>>>> + * struct rkisp1_ext_params_aec_config - RkISP1 extensible params AEC config
> > > > >>>>> + *
> > > > >>>>> + * RkISP1 extensible parameters Auto-Exposure statistics configuration block.
> > > > >>>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AEC_MEAS`.
> > > > >>>>> + *
> > > > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > > > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > > > >>>>> + * @config: Auto-Exposure statistics configuration, see
> > > > >>>>> + *	    :c:type:`rkisp1_cif_isp_aec_config`
> > > > >>>>> + */
> > > > >>>>> +struct rkisp1_ext_params_aec_config {
> > > > >>>>> +	struct rkisp1_ext_params_block_header header;
> > > > >>>>> +	struct rkisp1_cif_isp_aec_config config;
> > > > >>>>> +} __attribute__((aligned(8)));
> > > > >>>>> +
> > > > >>>>> +/**
> > > > >>>>> + * struct rkisp1_ext_params_afc_config - RkISP1 extensible params AFC config
> > > > >>>>> + *
> > > > >>>>> + * RkISP1 extensible parameters Auto-Focus statistics configuration block.
> > > > >>>>> + * Identified by :c:type:`RKISP1_EXT_PARAMS_BLOCK_TYPE_AFC_MEAS`.
> > > > >>>>> + *
> > > > >>>>> + * @header: The RkISP1 extensible parameters header, see
> > > > >>>>> + *	    :c:type:`rkisp1_ext_params_block_header`
> > > > >>>>> + * @config: Auto-Focus statistics configuration, see
> > > > >>>>> + *	    :c:type:`rkisp1_cif_isp_afc_config`
> > > > >>>>> + */
> > > > >>>>> +struct rkisp1_ext_params_afc_config {
> > > > >>>>> +	struct rkisp1_ext_params_block_header header;
> > > > >>>>> +	struct rkisp1_cif_isp_afc_config config;
> > > > >>>>> +} __attribute__((aligned(8)));
> > > > >>>>> +
> > > > >>>>> +#define RKISP1_EXT_PARAMS_MAX_SIZE					\
> > > > >>>>> +	(sizeof(struct rkisp1_ext_params_bls_config)			+\
> > > > >>>>> +	sizeof(struct rkisp1_ext_params_dpcc_config)			+\
> > > > >>>>> +	sizeof(struct rkisp1_ext_params_sdg_config)			+\
> > > > >>>>> +	sizeof(struct rkisp1_ext_params_lsc_config)			+\
> > > > >>>>> +	sizeof(struct rkisp1_ext_params_awb_gain_config)		+\
> > > > >>>>> +	sizeof(struct rkisp1_ext_params_flt_config)			+\
> > > > >>>>> +	sizeof(struct rkisp1_ext_params_bdm_config)			+\
> > > > >>>>> +	sizeof(struct rkisp1_ext_params_ctk_config)			+\
> > > > >>>>> +	sizeof(struct rkisp1_ext_params_goc_config)			+\
> > > > >>>>> +	sizeof(struct rkisp1_ext_params_dpf_config)			+\
> > > > >>>>> +	sizeof(struct rkisp1_ext_params_dpf_strength_config)		+\
> > > > >>>>> +	sizeof(struct rkisp1_ext_params_cproc_config)			+\
> > > > >>>>> +	sizeof(struct rkisp1_ext_params_ie_config)			+\
> > > > >>>>> +	sizeof(struct rkisp1_ext_params_awb_meas_config)		+\
> > > > >>>>> +	sizeof(struct rkisp1_ext_params_hst_config)			+\
> > > > >>>>> +	sizeof(struct rkisp1_ext_params_aec_config)			+\
> > > > >>>>> +	sizeof(struct rkisp1_ext_params_afc_config))
> > > > >>>>> +
> > > > >>>>> +/**
> > > > >>>>> + * enum rksip1_ext_param_buffer_version - RkISP1 extensible parameters version
> > > > >>>>> + *
> > > > >>>>> + * @RKISP1_EXT_PARAM_BUFFER_V1: First version of RkISP1 extensible parameters
> > > > >>>>> + */
> > > > >>>>> +enum rksip1_ext_param_buffer_version {
> > > > >>>>> +	RKISP1_EXT_PARAM_BUFFER_V1 = 1,
> > > > >>>>> +};
> > > > >>>>> +
> > > > >>>>> +/**
> > > > >>>>> + * struct rkisp1_ext_params_cfg - RkISP1 extensible parameters configuration
> > > > >>>>> + *
> > > > >>>>> + * This struct contains the configuration parameters of the RkISP1 ISP
> > > > >>>>> + * algorithms, serialized by userspace into a data buffer. Each configuration
> > > > >>>>> + * parameter block is represented by a block-specific structure which contains a
> > > > >>>>> + * :c:type:`rkisp1_ext_params_block_header` entry as first member. Userspace
> > > > >>>>> + * populates the @data buffer with configuration parameters for the blocks that
> > > > >>>>> + * it intends to configure. As a consequence, the data buffer effective size
> > > > >>>>> + * changes according to the number of ISP blocks that userspace intends to
> > > > >>>>> + * configure and is set by userspace in the @data_size field.
> > > > >>>>> + *
> > > > >>>>> + * The parameters buffer is versioned by the @version field to allow modifying
> > > > >>>>> + * and extending its definition. Userspace shall populate the @version field to
> > > > >>>>> + * inform the driver about the version it intends to use. The driver will parse
> > > > >>>>> + * and handle the @data buffer according to the data layout specific to the
> > > > >>>>> + * indicated version and return an error if the desired version is not
> > > > >>>>> + * supported.
> > > > >>>>> + *
> > > > >>>>> + * For each ISP block that userspace wants to configure, a block-specific
> > > > >>>>> + * structure is appended to the @data buffer, one after the other without gaps
> > > > >>>>> + * in between nor overlaps. Userspace shall populate the @data_size field with
> > > > >>>>> + * the effective size, in bytes, of the @data buffer.
> > > > >>>>> + *
> > > > >>>>> + * The expected memory layout of the parameters buffer is::
> > > > >>>>> + *
> > > > >>>>> + *	+-------------------- struct rkisp1_ext_params_cfg -------------------+
> > > > >>>>> + *	| version = RKISP_EXT_PARAMS_BUFFER_V1;                               |
> > > > >>>>> + *	| data_size = sizeof(struct rkisp1_ext_params_bls_config)             |
> > > > >>>>> + *	|           + sizeof(struct rkisp1_ext_params_dpcc_config);           |
> > > > >>>>> + *	| +------------------------- data  ---------------------------------+ |
> > > > >>>>> + *	| | +------------- struct rkisp1_ext_params_bls_config -----------+ | |
> > > > >>>>> + *	| | | +-------- struct rkisp1_ext_params_block_header  ---------+ | | |
> > > > >>>>> + *	| | | | type = RKISP1_EXT_PARAMS_BLOCK_TYPE_BLS;                | | | |
> > > > >>>>> + *	| | | | enable = RKISP1_EXT_PARAMS_BLOCK_ENABLE;                | | | |
> > > > >>>>> + *	| | | | size = sizeof(struct rkisp1_ext_params_bls_config);     | | | |
> > > > >>>>> + *	| | | +---------------------------------------------------------+ | | |
> > > > >>>>> + *	| | | +---------- struct rkisp1_cif_isp_bls_config -------------+ | | |
> > > > >>>>> + *	| | | | enable_auto = 0;                                        | | | |
> > > > >>>>> + *	| | | | fixed_val.r = 256;                                      | | | |
> > > > >>>>> + *	| | | | fixed_val.gr = 256;                                     | | | |
> > > > >>>>> + *	| | | | fixed_val.gb = 256;                                     | | | |
> > > > >>>>> + *	| | | | fixed_val.b = 256;                                      | | | |
> > > > >>>>> + *	| | | +---------------------------------------------------------+ | | |
> > > > >>>>> + *	| | +------------ struct rkisp1_ext_params_dpcc_config -----------+ | |
> > > > >>>>> + *	| | | +-------- struct rkisp1_ext_params_block_header  ---------+ | | |
> > > > >>>>> + *	| | | | type = RKISP1_EXT_PARAMS_BLOCK_TYPE_DPCC;               | | | |
> > > > >>>>> + *	| | | | enable = RKISP1_EXT_PARAMS_BLOCK_ENABLE;                | | | |
> > > > >>>>> + *	| | | | size = sizeof(struct rkisp1_ext_params_dpcc_config);    | | | |
> > > > >>>>> + *	| | | +---------------------------------------------------------+ | | |
> > > > >>>>> + *	| | | +---------- struct rkisp1_cif_isp_dpcc_config ------------+ | | |
> > > > >>>>> + *	| | | | mode = RKISP1_CIF_ISP_DPCC_MODE_STAGE1_ENABLE;          | | | |
> > > > >>>>> + *	| | | | output_mode =                                           | | | |
> > > > >>>>> + *	| | | |   RKISP1_CIF_ISP_DPCC_OUTPUT_MODE_STAGE1_INCL_G_CENTER; | | | |
> > > > >>>>> + *	| | | | set_use = ... ;                                         | | | |
> > > > >>>>> + *	| | | | ...  = ... ;                                            | | | |
> > > > >>>>> + *	| | | +---------------------------------------------------------+ | | |
> > > > >>>>> + *	| | +-------------------------------------------------------------+ | |
> > > > >>>>> + *	| +-----------------------------------------------------------------+ |
> > > > >>>>> + *	+---------------------------------------------------------------------+
> > > > >>>>> + *
> > > > >>>>> + * @version: The RkISP1 extensible parameters buffer version, see
> > > > >>>>> + *	     :c:type:`rksip1_ext_param_buffer_version`
> > > > >>>>> + * @data_size: The RkISP1 configuration data effective size, excluding this
> > > > >>>>> + *	       header
> > > > >>>>> + * @data: The RkISP1 extensible configuration data blocks
> > > > >>>>> + */
> > > > >>>>> +struct rkisp1_ext_params_cfg {
> > > > >>>>> +	__u32 version;
> > > > >>>>> +	__u32 data_size;
> > > > >>>>> +	__u8 data[RKISP1_EXT_PARAMS_MAX_SIZE];
> > > > >>>>> +};
> > > > >>>>> +
> > > > >>>>>  #endif /* _UAPI_RKISP1_CONFIG_H */

-- 
Regards,

Laurent Pinchart

Re: [PATCH v7 01/12] media: uapi: rkisp1-config: Add extensible params format

[Sakari Ailus]

Hi Laurent, Jacopo,

On Tue, Aug 06, 2024 at 12:32:22PM +0300, Laurent Pinchart wrote:
> On Tue, Aug 06, 2024 at 11:16:05AM +0200, Jacopo Mondi wrote:
> > On Tue, Aug 06, 2024 at 12:06:23PM GMT, Laurent Pinchart wrote:
> > > On Tue, Aug 06, 2024 at 10:24:20AM +0200, Jacopo Mondi wrote:
> > > > On Tue, Aug 06, 2024 at 10:17:02AM GMT, Hans Verkuil wrote:
> > > > > For compound control (which have similar problems) I have quite strict
> > > > > requirements: the structure layout may not contain any holes, and I require (and
> > > > > test) that any reserved/padding fields at set to 0 by the driver and that it is
> > > > > documented that userspace sets it to 0 as well.
> > > > >
> > > > > My recommendation for public APIs that effectively return data structures
> > > > > is to:
> > > > >
> > > > > 1) ensure the layout is the same for 32 and 64 bit code,
> > >
> > > Yes, that's very important.
> > >
> > > > > 2) there are no holes, instead use reserved[] arrays instead,
> > >
> > > Fine with me.
> > 
> > Do we all agree I can't change the existing types, and we'll have to
> > live with holes ?
> 
> We may be able to change the existing structures, but that would be a
> separate patch, outside of the scope of this series.

I'd say "we can" as long as it doesn't affect the memory layout of the
interface structs.

-- 
Kind regards,

Sakari Ailus