v4l2-isp.h

  1/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
  2/*
  3 * Video4Linux2 generic ISP parameters and statistics support
  4 *
  5 * Copyright (C) 2025 Ideas On Board Oy
  6 * Author: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
  7 */
  8
  9#ifndef _UAPI_V4L2_ISP_H_
 10#define _UAPI_V4L2_ISP_H_
 11
 12#include <linux/stddef.h>
 13#include <linux/types.h>
 14
 15/**
 16 * enum v4l2_isp_params_version - V4L2 ISP parameters versioning
 17 *
 18 * @V4L2_ISP_PARAMS_VERSION_V0: First version of the V4L2 ISP parameters format
 19 *				(for compatibility)
 20 * @V4L2_ISP_PARAMS_VERSION_V1: First version of the V4L2 ISP parameters format
 21 *
 22 * V0 and V1 are identical in order to support drivers compatible with the V4L2
 23 * ISP parameters format already upstreamed which use either 0 or 1 as their
 24 * versioning identifier. Both V0 and V1 refers to the first version of the
 25 * V4L2 ISP parameters format.
 26 *
 27 * Future revisions of the V4L2 ISP parameters format should start from the
 28 * value of 2.
 29 */
 30enum v4l2_isp_params_version {
 31	V4L2_ISP_PARAMS_VERSION_V0 = 0,
 32	V4L2_ISP_PARAMS_VERSION_V1
 33};
 34
 35#define V4L2_ISP_PARAMS_FL_BLOCK_DISABLE	(1U << 0)
 36#define V4L2_ISP_PARAMS_FL_BLOCK_ENABLE		(1U << 1)
 37
 38/*
 39 * Reserve the first 8 bits for V4L2_ISP_PARAMS_FL_* flag.
 40 *
 41 * Driver-specific flags should be defined as:
 42 * #define DRIVER_SPECIFIC_FLAG0     ((1U << V4L2_ISP_PARAMS_FL_DRIVER_FLAGS(0))
 43 * #define DRIVER_SPECIFIC_FLAG1     ((1U << V4L2_ISP_PARAMS_FL_DRIVER_FLAGS(1))
 44 */
 45#define V4L2_ISP_PARAMS_FL_DRIVER_FLAGS(n)       ((n) + 8)
 46
 47/**
 48 * struct v4l2_isp_params_block_header - V4L2 extensible parameters block header
 49 * @type: The parameters block type (driver-specific)
 50 * @flags: A bitmask of block flags (driver-specific)
 51 * @size: Size (in bytes) of the parameters block, including this header
 52 *
 53 * This structure represents the common part of all the ISP configuration
 54 * blocks. Each parameters block shall embed an instance of this structure type
 55 * as its first member, followed by the block-specific configuration data.
 56 *
 57 * The @type field is an ISP driver-specific value that identifies the block
 58 * type. The @size field specifies the size of the parameters block.
 59 *
 60 * The @flags field is a bitmask of per-block flags V4L2_PARAMS_ISP_FL_* and
 61 * driver-specific flags specified by the driver header.
 62 */
 63struct v4l2_isp_params_block_header {
 64	__u16 type;
 65	__u16 flags;
 66	__u32 size;
 67} __attribute__((aligned(8)));
 68
 69/**
 70 * struct v4l2_isp_params_buffer - V4L2 extensible parameters configuration
 71 * @version: The parameters buffer version (driver-specific)
 72 * @data_size: The configuration data effective size, excluding this header
 73 * @data: The configuration data
 74 *
 75 * This structure contains the configuration parameters of the ISP algorithms,
 76 * serialized by userspace into a data buffer. Each configuration parameter
 77 * block is represented by a block-specific structure which contains a
 78 * :c:type:`v4l2_isp_params_block_header` entry as first member. Userspace
 79 * populates the @data buffer with configuration parameters for the blocks that
 80 * it intends to configure. As a consequence, the data buffer effective size
 81 * changes according to the number of ISP blocks that userspace intends to
 82 * configure and is set by userspace in the @data_size field.
 83 *
 84 * The parameters buffer is versioned by the @version field to allow modifying
 85 * and extending its definition. Userspace shall populate the @version field to
 86 * inform the driver about the version it intends to use. The driver will parse
 87 * and handle the @data buffer according to the data layout specific to the
 88 * indicated version and return an error if the desired version is not
 89 * supported.
 90 *
 91 * For each ISP block that userspace wants to configure, a block-specific
 92 * structure is appended to the @data buffer, one after the other without gaps
 93 * in between. Userspace shall populate the @data_size field with the effective
 94 * size, in bytes, of the @data buffer.
 95 */
 96struct v4l2_isp_params_buffer {
 97	__u32 version;
 98	__u32 data_size;
 99	__u8 data[] __counted_by(data_size);
100};
101
102#endif /* _UAPI_V4L2_ISP_H_ */