Re: [PATCH v4 2/8] media: uapi: Convert RkISP1 to V4L2 extensible params

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

On Wed, Aug 20, 2025 at 02:58:10PM +0200, Jacopo Mondi wrote:
> With the introduction of common types for extensible parameters
> format, convert the rkisp1-config.h header to use the new types.
> 
> Factor-out the documentation that is now part of the common header
> and only keep the driver-specific on in place.
> 
> The conversion to use common types doesn't impact userspace as the
> new types are either identical to the ones already existing in the
> RkISP1 uAPI or are 1-to-1 type convertible.
> 
> Reviewed-by: Daniel Scally <dan.scally@ideasonboard.com>
> Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
> ---
>  include/uapi/linux/rkisp1-config.h | 67 +++++++++++++-------------------------
>  1 file changed, 23 insertions(+), 44 deletions(-)
> 
> diff --git a/include/uapi/linux/rkisp1-config.h b/include/uapi/linux/rkisp1-config.h
> index 3b060ea6eed71b87d79abc8401eae4e9c9f5323a..fc040c7fb13cf18eaf8d9067e7be38bff120e6f6 100644
> --- a/include/uapi/linux/rkisp1-config.h
> +++ b/include/uapi/linux/rkisp1-config.h
> @@ -7,8 +7,13 @@
>  #ifndef _UAPI_RKISP1_CONFIG_H
>  #define _UAPI_RKISP1_CONFIG_H
>  
> +#ifdef __KERNEL__
> +#include <linux/build_bug.h>
> +#endif /* __KERNEL__ */
>  #include <linux/types.h>
>  
> +#include <linux/media/v4l2-extensible-params.h>
> +
>  /* Defect Pixel Cluster Detection */
>  #define RKISP1_CIF_ISP_MODULE_DPCC		(1U << 0)
>  /* Black Level Subtraction */
> @@ -1158,26 +1163,21 @@ enum rkisp1_ext_params_block_type {
>  	RKISP1_EXT_PARAMS_BLOCK_TYPE_WDR,
>  };
>  

/* For backward compatibility */

> -#define RKISP1_EXT_PARAMS_FL_BLOCK_DISABLE	(1U << 0)
> -#define RKISP1_EXT_PARAMS_FL_BLOCK_ENABLE	(1U << 1)
> +#define RKISP1_EXT_PARAMS_FL_BLOCK_DISABLE	V4L2_PARAMS_FL_BLOCK_DISABLE
> +#define RKISP1_EXT_PARAMS_FL_BLOCK_ENABLE	V4L2_PARAMS_FL_BLOCK_ENABLE
>  
>  /* A bitmask of parameters blocks supported on the current hardware. */
>  #define RKISP1_CID_SUPPORTED_PARAMS_BLOCKS	(V4L2_CID_USER_RKISP1_BASE + 0x01)
>  
>  /**
> - * struct rkisp1_ext_params_block_header - RkISP1 extensible parameters block
> - *					   header
> + * rkisp1_ext_params_block_header - RkISP1 extensible parameters 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.
> + * blocks and is identical to :c:type:`v4l2_params_block_header`.
>   *
> - * The @type field is one of the values enumerated by
> + * 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
> + * 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 RKISP1_EXT_PARAMS_FL_*.

@flags leftover.

> @@ -1193,14 +1193,14 @@ enum rkisp1_ext_params_block_type {
>   * If a new configuration of an ISP block has to be applied userspace shall
>   * fully populate the ISP block configuration and omit setting the
>   * RKISP1_EXT_PARAMS_FL_BLOCK_ENABLE and RKISP1_EXT_PARAMS_FL_BLOCK_DISABLE bits
> - * in the @flags field.
> + * in the flags field.
>   *
>   * Setting both the RKISP1_EXT_PARAMS_FL_BLOCK_ENABLE and
> - * RKISP1_EXT_PARAMS_FL_BLOCK_DISABLE bits in the @flags field is not allowed
> + * RKISP1_EXT_PARAMS_FL_BLOCK_DISABLE bits in the flags field is not allowed
>   * and not accepted by the driver.
>   *
>   * Userspace is responsible for correctly populating the parameters block header
> - * fields (@type, @flags and @size) and the block-specific parameters.
> + * fields (type, flags and size) and the block-specific parameters.

Shouldn't you drop the parts of the documentation the duplicate
v4l2_params_block_header ? Same below.

>   *
>   * For example:
>   *
> @@ -1220,17 +1220,8 @@ enum rkisp1_ext_params_block_type {
>   *		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`
> - * @flags: A bitmask of block flags
> - * @size: Size (in bytes) of the parameters block, including this header
>   */
> -struct rkisp1_ext_params_block_header {
> -	__u16 type;
> -	__u16 flags;
> -	__u32 size;
> -};
> +#define rkisp1_ext_params_block_header v4l2_params_block_header
>  
>  /**
>   * struct rkisp1_ext_params_bls_config - RkISP1 extensible params BLS config
> @@ -1594,21 +1585,7 @@ enum rksip1_ext_param_buffer_version {
>  /**
>   * 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.
> + * This is the driver-specific implementation of :c:type:`v4l2_params_buffer`.
>   *
>   * Currently the single RKISP1_EXT_PARAM_BUFFER_V1 version is supported.
>   * When a new format version will be added, a mechanism for userspace to query
> @@ -1624,11 +1601,6 @@ enum rksip1_ext_param_buffer_version {
>   * the maximum value represents the blocks supported by the kernel driver,
>   * independently of the device instance.
>   *
> - * 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 -------------------+
> @@ -1678,4 +1650,11 @@ struct rkisp1_ext_params_cfg {
>  	__u8 data[RKISP1_EXT_PARAMS_MAX_SIZE];
>  };
>  
> +#ifdef __KERNEL__
> +/* Make sure the header is type-convertible to the generic v4l2 params one */
> +static_assert((sizeof(struct rkisp1_ext_params_cfg) -
> +	      RKISP1_EXT_PARAMS_MAX_SIZE) ==
> +	      sizeof(struct v4l2_params_buffer));
> +#endif /* __KERNEL__ */
> +
>  #endif /* _UAPI_RKISP1_CONFIG_H */
> 
> -- 
> 2.50.1
> 

-- 
Regards,

Laurent Pinchart

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