Re: [PATCH v5 07/10] media: uapi: Add stats info and parameters buffer for c3 ISP

Jacopo Mondi
2025-01-23T09:57:11Z

Hi Keke

On Fri, Dec 27, 2024 at 03:09:16PM +0800, Keke Li via B4 Relay wrote:
> From: Keke Li <keke.li@amlogic.com>
>
> Add a header that describes the 3A statistics buffer and the
> parameters buffer for c3 ISP

pahole is now happy and doesn't report holes or padding bytes.
There are a few issues with documentation which are reported here
https://gitlab.freedesktop.org/linux-media/users/jmondi/-/jobs/69823163/raw

./include/uapi/linux/media/amlogic/c3-isp-config.h:272: warning: expecting prototype for enum c3_isp_params_awb_tap_points. Prototype was for enum c3_isp_params_awb_tap_point instead
./include/uapi/linux/media/amlogic/c3-isp-config.h:328: warning: expecting prototype for enum c3_isp_params_ae_tap_points. Prototype was for enum c3_isp_params_ae_tap_point instead
./include/uapi/linux/media/amlogic/c3-isp-config.h:367: warning: expecting prototype for enum c3_isp_params_af_tap_points. Prototype was for enum c3_isp_params_af_tap_point instead

and possibily more.

With the above fixed (you should be able to check them by yourself by
building the documentation)
Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>

Thanks
j

>
> Signed-off-by: Keke Li <keke.li@amlogic.com>
> ---
> MAINTAINERS | 1 +
> include/uapi/linux/media/amlogic/c3-isp-config.h | 564 +++++++++++++++++++++++
> 2 files changed, 565 insertions(+)
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index bdf8b24c773f..274f72c31d9a 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -1248,6 +1248,7 @@ M: Keke Li <keke.li@amlogic.com>
> L: linux-media@vger.kernel.org
> S: Maintained
> F: Documentation/devicetree/bindings/media/amlogic,c3-isp.yaml
> +F: include/uapi/linux/media/amlogic/
>
> AMLOGIC MIPI ADAPTER DRIVER
> M: Keke Li <keke.li@amlogic.com>
> diff --git a/include/uapi/linux/media/amlogic/c3-isp-config.h b/include/uapi/linux/media/amlogic/c3-isp-config.h
> new file mode 100644
> index 000000000000..ee673ed022c0
> --- /dev/null
> +++ b/include/uapi/linux/media/amlogic/c3-isp-config.h
> @@ -0,0 +1,564 @@
> +/* SPDX-License-Identifier: GPL-2.0-only WITH Linux-syscall-note */
> +/*
> + * Copyright (C) 2024 Amlogic, Inc. All rights reserved
> + */
> +
> +#ifndef _UAPI_C3_ISP_CONFIG_H_
> +#define _UAPI_C3_ISP_CONFIG_H_
> +
> +#include <linux/types.h>
> +
> +/*
> + * Frames are split into zones of almost equal width and height - a zone is a
> + * rectangular tile of a frame. The metering blocks within the ISP collect
> + * aggregated statistics per zone.
> + */
> +#define C3_ISP_AE_MAX_ZONES (17 * 15)
> +#define C3_ISP_AF_MAX_ZONES (17 * 15)
> +#define C3_ISP_AWB_MAX_ZONES (32 * 24)
> +
> +/* The maximum number of point on the diagonal of the frame for statistics */
> +#define C3_ISP_AE_MAX_PT_NUM 18
> +#define C3_ISP_AF_MAX_PT_NUM 18
> +#define C3_ISP_AWB_MAX_PT_NUM 33
> +
> +/**
> + * struct c3_isp_awb_zone_stats - AWB statistics of a zone
> + *
> + * AWB zone stats is aligned with 8 bytes
> + *
> + * @rg: the ratio of R / G in a zone
> + * @bg: the ratio of B / G in a zone
> + * @pixel_sum: the total number of pixels used in a zone
> + */
> +struct c3_isp_awb_zone_stats {
> + __u16 rg;
> + __u16 bg;
> + __u32 pixel_sum;
> +};
> +
> +/**
> + * struct c3_isp_awb_stats - Auto white balance statistics information.
> + *
> + * AWB statistical information of all zones.
> + *
> + * @stats: array of auto white balance statistics
> + */
> +struct c3_isp_awb_stats {
> + struct c3_isp_awb_zone_stats stats[C3_ISP_AWB_MAX_ZONES];
> +} __attribute__((aligned(16)));
> +
> +/**
> + * struct c3_isp_ae_zone_stats - AE statistics of a zone
> + *
> + * AE zone stats is aligned with 8 bytes.
> + * This is a 5-bin histogram and the total sum is normalized to 0xffff.
> + * So hist2 = 0xffff - (hist0 + hist1 + hist3 + hist4)
> + *
> + * @hist0: the global normalized pixel count for bin 0
> + * @hist1: the global normalized pixel count for bin 1
> + * @hist3: the global normalized pixel count for bin 3
> + * @hist4: the global normalized pixel count for bin 4
> + */
> +struct c3_isp_ae_zone_stats {
> + __u16 hist0;
> + __u16 hist1;
> + __u16 hist3;
> + __u16 hist4;
> +};
> +
> +/**
> + * struct c3_isp_ae_stats - Exposure statistics information
> + *
> + * AE statistical information consists of all blocks information and a 1024-bin
> + * histogram.
> + *
> + * @stats: array of auto exposure block statistics
> + * @reserved: undefined buffer space
> + * @hist: a 1024-bin histogram for the entire image
> + */
> +struct c3_isp_ae_stats {
> + struct c3_isp_ae_zone_stats stats[C3_ISP_AE_MAX_ZONES];
> + __u32 reserved[2];
> + __u32 hist[1024];
> +} __attribute__((aligned(16)));
> +
> +/**
> + * struct c3_isp_af_zone_stats - AF statistics of a zone
> + *
> + * AF zone stats is aligned with 8 bytes.
> + * The zonal accumulated contrast metrics are stored in floating point format
> + * with 16 bits mantissa and 5 or 6 bits exponent. Apart from contrast metrics
> + * we accumulate squared image and quartic image data over the zone.
> + *
> + * @i2_mat: the mantissa of zonal squared image pixel sum
> + * @i4_mat: the mantissa of zonal quartic image pixel sum
> + * @e4_mat: the mantissa of zonal multi-directional quartic edge sum
> + * @e4_exp: the exponent of zonal multi-directional quartic edge sum
> + * @i2_exp: the exponent of zonal squared image pixel sum
> + * @i4_exp: the exponent of zonal quartic image pixel sum
> + */
> +struct c3_isp_af_zone_stats {
> + __u16 i2_mat;
> + __u16 i4_mat;
> + __u16 e4_mat;
> + __u16 e4_exp : 5;
> + __u16 i2_exp : 5;
> + __u16 i4_exp : 6;
> +};
> +
> +/**
> + * struct c3_isp_af_stats - Auto Focus statistics information
> + *
> + * AF statistical information of each zone
> + *
> + * @stats: array of auto focus block statistics
> + * @reserved: undefined buffer space
> + */
> +struct c3_isp_af_stats {
> + struct c3_isp_af_zone_stats stats[C3_ISP_AF_MAX_ZONES];
> + __u32 reserved[2];
> +} __attribute__((aligned(16)));
> +
> +/**
> + * struct c3_isp_stats_info - V4L2_META_FMT_C3ISP_STATS
> + *
> + * Contains ISP statistics
> + *
> + * @awb: auto white balance stats
> + * @ae: auto exposure stats
> + * @af: auto focus stats
> + */
> +struct c3_isp_stats_info {
> + struct c3_isp_awb_stats awb;
> + struct c3_isp_ae_stats ae;
> + struct c3_isp_af_stats af;
> +};
> +
> +/**
> + * enum c3_isp_params_buffer_version - C3 ISP parameters block versioning
> + *
> + * @C3_ISP_PARAMS_BUFFER_V0: First version of C3 ISP parameters block
> + */
> +enum c3_isp_params_buffer_version {
> + C3_ISP_PARAMS_BUFFER_V0,
> +};
> +
> +/**
> + * enum c3_isp_params_block_type - Enumeration of C3 ISP parameter blocks
> + *
> + * Each block configures a specific processing block of the C3 ISP.
> + * The block type allows the driver to correctly interpret the parameters block
> + * data.
> + *
> + * @C3_ISP_PARAMS_BLOCK_AWB_GAINS: White balance gains
> + * @C3_ISP_PARAMS_BLOCK_AWB_CONFIG: AWB statistic format configuration for all
> + * blocks that control how stats are generated
> + * @C3_ISP_PARAMS_BLOCK_AE_CONFIG: AE statistic format configuration for all
> + * blocks that control how stats are generated
> + * @C3_ISP_PARAMS_BLOCK_AF_CONFIG: AF statistic format configuration for all
> + * blocks that control how stats are generated
> + * @C3_ISP_PARAMS_BLOCK_PST_GAMMA: post gamma parameters
> + * @C3_ISP_PARAMS_BLOCK_CCM: Color correction matrix parameters
> + * @C3_ISP_PARAMS_BLOCK_CSC: Color space conversion parameters
> + * @C3_ISP_PARAMS_BLOCK_BLC: Black level correction parameters
> + * @C3_ISP_PARAMS_BLOCK_SENTINEL: First non-valid block index
> + */
> +enum c3_isp_params_block_type {
> + C3_ISP_PARAMS_BLOCK_AWB_GAINS,
> + C3_ISP_PARAMS_BLOCK_AWB_CONFIG,
> + C3_ISP_PARAMS_BLOCK_AE_CONFIG,
> + C3_ISP_PARAMS_BLOCK_AF_CONFIG,
> + C3_ISP_PARAMS_BLOCK_PST_GAMMA,
> + C3_ISP_PARAMS_BLOCK_CCM,
> + C3_ISP_PARAMS_BLOCK_CSC,
> + C3_ISP_PARAMS_BLOCK_BLC,
> + C3_ISP_PARAMS_BLOCK_SENTINEL
> +};
> +
> +#define C3_ISP_PARAMS_BLOCK_FL_DISABLE (1U << 0)
> +#define C3_ISP_PARAMS_BLOCK_FL_ENABLE (1U << 1)
> +
> +/**
> + * struct c3_isp_params_block_header - C3 ISP 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:`c3_isp_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
> + * @flags field is a bitmask of per-block flags C3_ISP_PARAMS_FL*.
> + *
> + * When userspace wants to disable an ISP block the
> + * C3_ISP_PARAMS_BLOCK_FL_DISABLED bit should be set in the @flags field. In
> + * this case userspace may optionally omit the remainder of the configuration
> + * block, which will be ignored by the driver.
> + *
> + * When a new configuration of an ISP block needs to be applied userspace
> + * shall fully populate the ISP block and omit setting the
> + * C3_ISP_PARAMS_BLOCK_FL_DISABLED bit in the @flags field.
> + *
> + * Userspace is responsible for correctly populating the parameters block header
> + * fields (@type, @flags and @size) and the block-specific parameters.
> + *
> + * For example:
> + *
> + * .. code-block:: c
> + *
> + * void populate_pst_gamma(struct c3_isp_params_block_header *block) {
> + * struct c3_isp_params_pst_gamma *gamma =
> + * (struct c3_isp_params_pst_gamma *)block;
> + *
> + * gamma->header.type = C3_ISP_PARAMS_BLOCK_PST_GAMMA;
> + * gamma->header.flags = C3_ISP_PARAMS_BLOCK_FL_ENABLE;
> + * gamma->header.size = sizeof(*gamma);
> + *
> + * for (unsigned int i = 0; i < 129; i++)
> + * gamma->pst_gamma_lut[i] = i;
> + * }
> + *
> + * @type: The parameters block type from :c:type:`c3_isp_params_block_type`
> + * @flags: A bitmask of block flags
> + * @size: Size (in bytes) of the parameters block, including this header
> + */
> +struct c3_isp_params_block_header {
> + __u16 type;
> + __u16 flags;
> + __u32 size;
> +};
> +
> +/**
> + * struct c3_isp_params_awb_gains - Gains for auto-white balance
> + *
> + * This struct allows users to configure the gains for white balance.
> + * There are four gain settings corresponding to each colour channel in
> + * the bayer domain. All of the gains are stored in Q4.8 format.
> + *
> + * header.type should be set to C3_ISP_PARAMS_BLOCK_AWB_GAINS
> + * from :c:type:`c3_isp_params_block_type`
> + *
> + * @header: The C3 ISP parameters block header
> + * @gr_gain: Multiplier for Gr channel (Q4.8 format)
> + * @r_gain: Multiplier for R channel (Q4.8 format)
> + * @b_gain: Multiplier for B channel (Q4.8 format)
> + * @gb_gain: Multiplier for Gb channel (Q4.8 format)
> + */
> +struct c3_isp_params_awb_gains {
> + struct c3_isp_params_block_header header;
> + __u16 gr_gain;
> + __u16 r_gain;
> + __u16 b_gain;
> + __u16 gb_gain;
> +} __attribute__((aligned(8)));
> +
> +/**
> + * enum c3_isp_params_awb_tap_points - Tap points for the AWB statistics
> + * @C3_ISP_AWB_STATS_TAP_FE: immediately after the optical frontend block
> + * @C3_ISP_AWB_STATS_TAP_GE: immediately after the green equal block
> + * @C3_ISP_AWB_STATS_TAP_BEFORE_WB: immediately before the white balance block
> + * @C3_ISP_AWB_STATS_TAP_AFTER_WB: immediately after the white balance block
> + */
> +enum c3_isp_params_awb_tap_point {
> + C3_ISP_AWB_STATS_TAP_OFE = 0,
> + C3_ISP_AWB_STATS_TAP_GE,
> + C3_ISP_AWB_STATS_TAP_BEFORE_WB,
> + C3_ISP_AWB_STATS_TAP_AFTER_WB,
> +};
> +
> +/**
> + * struct c3_isp_params_awb_config - Stats settings for auto-white balance
> + *
> + * This struct allows the configuration of the statistics generated for auto
> + * white balance.
> + *
> + * header.type should be set to C3_ISP_PARAMS_BLOCK_AWB_CONFIG
> + * from :c:type:`c3_isp_params_block_type`
> + *
> + * @header: the C3 ISP parameters block header
> + * @tap_point: the tap point from enum c3_isp_params_awb_tap_point
> + * @satur_vald: AWB statistic over saturation control
> + * value: 0: disable, 1: enable
> + * @horiz_zones_num: active number of hotizontal zones [0..32]
> + * @vert_zones_num: active number of vertical zones [0..24]
> + * @rg_min: minimum R/G ratio (Q4.8 format)
> + * @rg_max: maximum R/G ratio (Q4.8 format)
> + * @bg_min: minimum B/G ratio (Q4.8 format)
> + * @bg_max: maximum B/G ratio (Q4.8 format)
> + * @rg_low: R/G ratio trim low (Q4.8 format)
> + * @rg_high: R/G ratio trim hight (Q4.8 format)
> + * @bg_low: B/G ratio trim low (Q4.8 format)
> + * @bg_high: B/G ratio trim high (Q4.8 format)
> + * @zone_weight: array of weights for AWB statistics zones [0..15]
> + * @horiz_cood: the horizontal coordinate of points on the diagonal [0..2888]
> + * @vert_cood: the vertical coordinate of points on the diagonal [0..2240]
> + */
> +struct c3_isp_params_awb_config {
> + struct c3_isp_params_block_header header;
> + __u8 tap_point;
> + __u8 satur_vald;
> + __u8 horiz_zones_num;
> + __u8 vert_zones_num;
> + __u16 rg_min;
> + __u16 rg_max;
> + __u16 bg_min;
> + __u16 bg_max;
> + __u16 rg_low;
> + __u16 rg_high;
> + __u16 bg_low;
> + __u16 bg_high;
> + __u8 zone_weight[C3_ISP_AWB_MAX_ZONES];
> + __u16 horiz_cood[C3_ISP_AWB_MAX_PT_NUM];
> + __u16 vert_cood[C3_ISP_AWB_MAX_PT_NUM];
> +} __attribute__((aligned(8)));
> +
> +/**
> + * enum c3_isp_params_ae_tap_points - Tap points for the AE statistics
> + * @C3_ISP_AE_STATS_TAP_GE: immediately after the green equal block
> + * @C3_ISP_AE_STATS_TAP_MLS: immediately after the mesh lens shading block
> + */
> +enum c3_isp_params_ae_tap_point {
> + C3_ISP_AE_STATS_TAP_GE = 0,
> + C3_ISP_AE_STATS_TAP_MLS,
> +};
> +
> +/**
> + * struct c3_isp_params_ae_config - Stats settings for auto-exposure
> + *
> + * This struct allows the configuration of the statistics generated for
> + * auto exposure.
> + *
> + * header.type should be set to C3_ISP_PARAMS_BLOCK_AE_CONFIG
> + * from :c:type:`c3_isp_params_block_type`
> + *
> + * @header: the C3 ISP parameters block header
> + * @horiz_zones_num: active number of horizontal zones [0..17]
> + * @vert_zones_num: active number of vertical zones [0..15]
> + * @tap_point: the tap point from enum c3_isp_params_ae_tap_point
> + * @zone_weight: array of weights for AE statistics zones [0..15]
> + * @horiz_cood: the horizontal coordinate of points on the diagonal [0..2888]
> + * @vert_cood: the vertical coordinate of points on the diagonal [0..2240]
> + * @reserved: applications must zero this array
> + */
> +struct c3_isp_params_ae_config {
> + struct c3_isp_params_block_header header;
> + __u8 tap_point;
> + __u8 horiz_zones_num;
> + __u8 vert_zones_num;
> + __u8 zone_weight[C3_ISP_AE_MAX_ZONES];
> + __u16 horiz_cood[C3_ISP_AE_MAX_PT_NUM];
> + __u16 vert_cood[C3_ISP_AE_MAX_PT_NUM];
> + __u16 reserved[3];
> +} __attribute__((aligned(8)));
> +
> +/**
> + * enum c3_isp_params_af_tap_points - Tap points for the AF statistics
> + * @C3_ISP_AF_STATS_TAP_SNR: immediately after the spatial noise reduce block
> + * @C3_ISP_AF_STATS_TAP_DMS: immediately after the demosaic block
> + */
> +enum c3_isp_params_af_tap_point {
> + C3_ISP_AF_STATS_TAP_SNR = 0,
> + C3_ISP_AF_STATS_TAP_DMS,
> +};
> +
> +/**
> + * struct c3_isp_params_af_config - Stats settings for auto-focus
> + *
> + * This struct allows the configuration of the statistics generated for
> + * auto focus.
> + *
> + * header.type should be set to C3_ISP_PARAMS_BLOCK_AF_CONFIG
> + * from :c:type:`c3_isp_params_block_type`
> + *
> + * @header: the C3 ISP parameters block header
> + * @tap_point: the tap point from enum c3_isp_params_af_tap_point
> + * @horiz_zones_num: active number of hotizontal zones [0..17]
> + * @vert_zones_num: active number of vertical zones [0..15]
> + * @reserved: applications must zero this array
> + * @horiz_cood: the horizontal coordinate of points on the diagonal [0..2888]
> + * @vert_cood: the vertical coordinate of points on the diagonal [0..2240]
> + */
> +struct c3_isp_params_af_config {
> + struct c3_isp_params_block_header header;
> + __u8 tap_point;
> + __u8 horiz_zones_num;
> + __u8 vert_zones_num;
> + __u8 reserved[5];
> + __u16 horiz_cood[C3_ISP_AF_MAX_PT_NUM];
> + __u16 vert_cood[C3_ISP_AF_MAX_PT_NUM];
> +} __attribute__((aligned(8)));
> +
> +/**
> + * struct c3_isp_params_pst_gamma - Post gamma configuration
> + *
> + * This struct allows the configuration of the look up table for
> + * post gamma. The gamma curve consists of 129 points, so need to
> + * set lut[129].
> + *
> + * header.type should be set to C3_ISP_PARAMS_BLOCK_PST_GAMMA
> + * from :c:type:`c3_isp_params_block_type`
> + *
> + * @header: the C3 ISP parameters block header
> + * @lut: lookup table for P-Stitch gamma [0..1023]
> + * @reserved: applications must zero this array
> + */
> +struct c3_isp_params_pst_gamma {
> + struct c3_isp_params_block_header header;
> + __u16 lut[129];
> + __u16 reserved[3];
> +} __attribute__((aligned(8)));
> +
> +/**
> + * struct c3_isp_params_ccm - ISP CCM configuration
> + *
> + * This struct allows the configuration of the matrix for
> + * color correction. The matrix consists of 3 x 3 points,
> + * so need to set matrix[3][3].
> + *
> + * header.type should be set to C3_ISP_PARAMS_BLOCK_CCM
> + * from :c:type:`c3_isp_params_block_type`
> + *
> + * @header: the C3 ISP parameters block header
> + * @matrix: a 3 x 3 matrix used for color correction,
> + * the value of matrix[x][y] is orig_value x 256. [-4096..4095]
> + * @reserved: applications must zero this array
> + */
> +struct c3_isp_params_ccm {
> + struct c3_isp_params_block_header header;
> + __s16 matrix[3][3];
> + __u16 reserved[3];
> +} __attribute__((aligned(8)));
> +
> +/**
> + * struct c3_isp_params_csc - ISP Color Space Conversion configuration
> + *
> + * This struct allows the configuration of the matrix for color space
> + * conversion. The matrix consists of 3 x 3 points, so need to set matrix[3][3].
> + *
> + * header.type should be set to C3_ISP_PARAMS_BLOCK_CSC
> + * from :c:type:`c3_isp_params_block_type`
> + *
> + * @header: the C3 ISP parameters block header
> + * @matrix: a 3x3 matrix used for the color space conversion,
> + * the value of matrix[x][y] is orig_value x 256. [-4096..4095]
> + * @reserved: applications must zero this array
> + */
> +struct c3_isp_params_csc {
> + struct c3_isp_params_block_header header;
> + __s16 matrix[3][3];
> + __u16 reserved[3];
> +} __attribute__((aligned(8)));
> +
> +/**
> + * struct c3_isp_params_blc - ISP Black Level Correction configuration
> + *
> + * This struct allows the configuration of the block level offset for each
> + * color channel.
> + *
> + * header.type should be set to C3_ISP_PARAMS_BLOCK_BLC
> + * from :c:type:`c3_isp_params_block_type`
> + *
> + * @header: the C3 ISP parameters block header
> + * @gr_ofst: Gr blc offset (Q4.8 format)
> + * @r_ofst: R blc offset (Q4.8 format)
> + * @b_ofst: B blc offset (Q4.8 format)
> + * @gb_ofst: Gb blc offset(Q4.8 format)
> + */
> +struct c3_isp_params_blc {
> + struct c3_isp_params_block_header header;
> + __u16 gr_ofst;
> + __u16 r_ofst;
> + __u16 b_ofst;
> + __u16 gb_ofst;
> +};
> +
> +/**
> + * define C3_ISP_PARAMS_MAX_SIZE - Maximum size of all C3 ISP Parameters
> + *
> + * Though the parameters for the C3 ISP are passed as optional blocks, the
> + * driver still needs to know the absolute maximum size so that it can allocate
> + * a buffer sized appropriately to accommodate userspace attempting to set all
> + * possible parameters in a single frame.
> + */
> +#define C3_ISP_PARAMS_MAX_SIZE \
> + (sizeof(struct c3_isp_params_awb_gains) + \
> + sizeof(struct c3_isp_params_awb_config) + \
> + sizeof(struct c3_isp_params_ae_config) + \
> + sizeof(struct c3_isp_params_af_config) + \
> + sizeof(struct c3_isp_params_pst_gamma) + \
> + sizeof(struct c3_isp_params_ccm) + \
> + sizeof(struct c3_isp_params_csc) + \
> + sizeof(struct c3_isp_params_blc))
> +
> +/**
> + * struct c3_isp_params_cfg - C3 ISP configuration parameters
> + *
> + * This struct contains the configuration parameters of the C3 ISP
> + * algorithms, serialized by userspace into an opaque data buffer. Each
> + * configuration parameter block is represented by a block-specific structure
> + * which contains a :c:type:`c3_isp_param_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.
> + *
> + * The parameters buffer is versioned by the @version field to allow modifying
> + * and extending its definition. Userspace should 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 revision and return an error if the desired revision 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 @total_size field with
> + * the effective size, in bytes, of the @data buffer.
> + *
> + * The expected memory layout of the parameters buffer is::
> + *
> + * +-------------------- struct c3_isp_params_cfg ---- ------------------+
> + * | version = C3_ISP_PARAM_BUFFER_V0; |
> + * | data_size = sizeof(struct c3_isp_params_awb_gains) + |
> + * | sizeof(struct c3_isp_params_awb_config); |
> + * | +------------------------- data ---------------------------------+ |
> + * | | +------------ struct c3_isp_params_awb_gains) ------------------+ |
> + * | | | +--------- struct c3_isp_params_block_header header -----+ | | |
> + * | | | | type = C3_ISP_PARAMS_BLOCK_AWB_GAINS; | | | |
> + * | | | | flags = C3_ISP_PARAMS_BLOCK_FL_NONE; | | | |
> + * | | | | size = sizeof(struct c3_isp_params_awb_gains); | | | |
> + * | | | +---------------------------------------------------------+ | | |
> + * | | | gr_gain = ...; | | |
> + * | | | r_gain = ...; | | |
> + * | | | b_gain = ...; | | |
> + * | | | gb_gain = ...; | | |
> + * | | +------------------ struct c3_isp_params_awb_config ----------+ | |
> + * | | | +---------- struct c3_isp_param_block_header header ------+ | | |
> + * | | | | type = C3_ISP_PARAMS_BLOCK_AWB_CONFIG; | | | |
> + * | | | | flags = C3_ISP_PARAMS_BLOCK_FL_NONE; | | | |
> + * | | | | size = sizeof(struct c3_isp_params_awb_config) | | | |
> + * | | | +---------------------------------------------------------+ | | |
> + * | | | tap_point = ...; | | |
> + * | | | satur_vald = ...; | | |
> + * | | | horiz_zones_num = ...; | | |
> + * | | | vert_zones_num = ...; | | |
> + * | | +-------------------------------------------------------------+ | |
> + * | +-----------------------------------------------------------------+ |
> + * +---------------------------------------------------------------------+
> + *
> + * @version: The C3 ISP parameters buffer version
> + * @data_size: The C3 ISP configuration data effective size, excluding this
> + * header
> + * @data: The C3 ISP configuration blocks data
> + */
> +struct c3_isp_params_cfg {
> + __u32 version;
> + __u32 data_size;
> + __u8 data[C3_ISP_PARAMS_MAX_SIZE];
> +};
> +
> +#endif
>
> --
> 2.47.1
>
>
>