[v4,1/5] include: linux: Add v4l2-isp.h

24542 diff mbox series

Import the v4l2-isp.h header from the Linux kernel sources.

The file has not been merged in mainline Linux yet but is available
at:
https://lore.kernel.org/all/20250915-extensible-parameters-validation-v5-0-e6db94468af3@ideasonboard.com/

Create the include/linux/media/ directory so that header files
exported from the kernel which include this file do not need
to be adjusted when imported in libcamera.

Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Tested-By: Antoine Bouyer <antoine.bouyer@nxp.com>
---
 include/linux/media/v4l2-isp.h | 100 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 100 insertions(+)

On Wed, Oct 01, 2025 at 05:42:30PM +0200, Jacopo Mondi wrote:
> Import the v4l2-isp.h header from the Linux kernel sources.
> 
> The file has not been merged in mainline Linux yet but is available
> at:
> https://lore.kernel.org/all/20250915-extensible-parameters-validation-v5-0-e6db94468af3@ideasonboard.com/
> 
> Create the include/linux/media/ directory so that header files
> exported from the kernel which include this file do not need
> to be adjusted when imported in libcamera.
> 
> Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
> Tested-By: Antoine Bouyer <antoine.bouyer@nxp.com>

The header will change, but I expect the ABI to be preserved, so we can
easily update it later.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

It would be nice to have a patch for utils/update-kernel-headers.sh in
this series, that we'll merge later once the v4l2-isp.h header is merged
upstream.

> ---
>  include/linux/media/v4l2-isp.h | 100 +++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 100 insertions(+)
> 
> diff --git a/include/linux/media/v4l2-isp.h b/include/linux/media/v4l2-isp.h
> new file mode 100644
> index 0000000000000000000000000000000000000000..fed89b5678585a3565d33cf873d0313dc089524f
> --- /dev/null
> +++ b/include/linux/media/v4l2-isp.h
> @@ -0,0 +1,100 @@
> +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
> +/*
> + * Video4Linux2 generic ISP parameters and statistics support
> + *
> + * Copyright (C) 2025 Ideas On Board Oy
> + * Author: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
> + */
> +
> +#ifndef _V4L2_ISP_H_
> +#define _V4L2_ISP_H_
> +
> +#include <linux/stddef.h>
> +#include <linux/types.h>
> +
> +#define V4L2_PARAMS_FL_BLOCK_DISABLE	(1U << 0)
> +#define V4L2_PARAMS_FL_BLOCK_ENABLE	(1U << 1)
> +
> +/*
> + * Reserve the first 8 bits for V4L2_PARAMS_FL_* flag.
> + *
> + * Driver-specific flags should be defined as:
> + * #define PLATFORM_SPECIFIC_FLAG0     ((1U << V4L2_PARAMS_FL_DRIVER_FLAGS(0))
> + * #define PLATFORM_SPECIFIC_FLAG1     ((1U << V4L2_PARAMS_FL_DRIVER_FLAGS(1))
> + */
> +#define V4L2_PARAMS_FL_DRIVER_FLAGS(n)       ((n) + 8)
> +
> +/**
> + * struct v4l2_params_block_header - V4L2 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.
> + *
> + * The @type field is an ISP driver-specific value that identifies the block
> + * type. The @size field specifies the size of the parameters block.
> + *
> + * The @flags field is a bitmask of per-block flags V4L2_PARAMS_FL_* and
> + * driver-specific flags specified by the driver header.
> + *
> + * @type: The parameters block type (driver-specific)
> + * @flags: A bitmask of block flags (driver-specific)
> + * @size: Size (in bytes) of the parameters block, including this header
> + */
> +struct v4l2_params_block_header {
> +	__u16 type;
> +	__u16 flags;
> +	__u32 size;
> +} __attribute__((aligned(8)));
> +
> +/**
> + * v4l2_params_buffer_size - Calculate size of v4l2_params_buffer for a platform
> + *
> + * Users of the v4l2 extensible parameters will have differing sized data arrays
> + * depending on their specific parameter buffers. Drivers and userspace will
> + * need to be able to calculate the appropriate size of the struct to
> + * accommodate all ISP configuration blocks provided by the platform.
> + * This macro provides a convenient tool for the calculation.
> + *
> + * @max_params_size: The total size of the ISP configuration blocks
> + */
> +#define v4l2_params_buffer_size(max_params_size) \
> +	(offsetof(struct v4l2_params_buffer, data) + (max_params_size))
> +
> +/**
> + * struct v4l2_params_buffer - V4L2 extensible parameters configuration
> + *
> + * This struct contains the configuration parameters of the 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:`v4l2_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.
> + *
> + * @version: The parameters buffer version (driver-specific)
> + * @data_size: The configuration data effective size, excluding this header
> + * @data: The configuration data
> + */
> +struct v4l2_params_buffer {
> +	__u32 version;
> +	__u32 data_size;
> +	__u8 data[] __counted_by(data_size);
> +};
> +
> +#endif /* _V4L2_ISP_H_ */

Hi Jacopo

On 01/10/2025 16:42, Jacopo Mondi wrote:
> Import the v4l2-isp.h header from the Linux kernel sources.
> 
> The file has not been merged in mainline Linux yet but is available
> at:
> https://lore.kernel.org/all/20250915-extensible-parameters-validation-v5-0-e6db94468af3@ideasonboard.com/
> 
> Create the include/linux/media/ directory so that header files
> exported from the kernel which include this file do not need
> to be adjusted when imported in libcamera.
> 
> Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
> Tested-By: Antoine Bouyer <antoine.bouyer@nxp.com>

Reviewed-by: Daniel Scally <dan.scally@ideasonboard.com>> ---
>   include/linux/media/v4l2-isp.h | 100 +++++++++++++++++++++++++++++++++++++++++
>   1 file changed, 100 insertions(+)
> 
> diff --git a/include/linux/media/v4l2-isp.h b/include/linux/media/v4l2-isp.h
> new file mode 100644
> index 0000000000000000000000000000000000000000..fed89b5678585a3565d33cf873d0313dc089524f
> --- /dev/null
> +++ b/include/linux/media/v4l2-isp.h
> @@ -0,0 +1,100 @@
> +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
> +/*
> + * Video4Linux2 generic ISP parameters and statistics support
> + *
> + * Copyright (C) 2025 Ideas On Board Oy
> + * Author: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
> + */
> +
> +#ifndef _V4L2_ISP_H_
> +#define _V4L2_ISP_H_
> +
> +#include <linux/stddef.h>
> +#include <linux/types.h>
> +
> +#define V4L2_PARAMS_FL_BLOCK_DISABLE	(1U << 0)
> +#define V4L2_PARAMS_FL_BLOCK_ENABLE	(1U << 1)
> +
> +/*
> + * Reserve the first 8 bits for V4L2_PARAMS_FL_* flag.
> + *
> + * Driver-specific flags should be defined as:
> + * #define PLATFORM_SPECIFIC_FLAG0     ((1U << V4L2_PARAMS_FL_DRIVER_FLAGS(0))
> + * #define PLATFORM_SPECIFIC_FLAG1     ((1U << V4L2_PARAMS_FL_DRIVER_FLAGS(1))
> + */
> +#define V4L2_PARAMS_FL_DRIVER_FLAGS(n)       ((n) + 8)
> +
> +/**
> + * struct v4l2_params_block_header - V4L2 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.
> + *
> + * The @type field is an ISP driver-specific value that identifies the block
> + * type. The @size field specifies the size of the parameters block.
> + *
> + * The @flags field is a bitmask of per-block flags V4L2_PARAMS_FL_* and
> + * driver-specific flags specified by the driver header.
> + *
> + * @type: The parameters block type (driver-specific)
> + * @flags: A bitmask of block flags (driver-specific)
> + * @size: Size (in bytes) of the parameters block, including this header
> + */
> +struct v4l2_params_block_header {
> +	__u16 type;
> +	__u16 flags;
> +	__u32 size;
> +} __attribute__((aligned(8)));
> +
> +/**
> + * v4l2_params_buffer_size - Calculate size of v4l2_params_buffer for a platform
> + *
> + * Users of the v4l2 extensible parameters will have differing sized data arrays
> + * depending on their specific parameter buffers. Drivers and userspace will
> + * need to be able to calculate the appropriate size of the struct to
> + * accommodate all ISP configuration blocks provided by the platform.
> + * This macro provides a convenient tool for the calculation.
> + *
> + * @max_params_size: The total size of the ISP configuration blocks
> + */
> +#define v4l2_params_buffer_size(max_params_size) \
> +	(offsetof(struct v4l2_params_buffer, data) + (max_params_size))
> +
> +/**
> + * struct v4l2_params_buffer - V4L2 extensible parameters configuration
> + *
> + * This struct contains the configuration parameters of the 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:`v4l2_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.
> + *
> + * @version: The parameters buffer version (driver-specific)
> + * @data_size: The configuration data effective size, excluding this header
> + * @data: The configuration data
> + */
> +struct v4l2_params_buffer {
> +	__u32 version;
> +	__u32 data_size;
> +	__u8 data[] __counted_by(data_size);
> +};
> +
> +#endif /* _V4L2_ISP_H_ */
>