[v5,2/5] include: linux: Add v4l2-isp.h
diff mbox series

Message ID 20251007-v4l2-params-v5-2-8db451a81398@ideasonboard.com
State New
Headers show
Series
  • ipa: libipa: Introduce V4L2Params
Related show

Commit Message

Jacopo Mondi Oct. 7, 2025, 6:17 p.m. UTC
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 v6:
https://lore.kernel.org/all/20251007-extensible-parameters-validation-v6-1-5f719d9f39e5@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: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 include/linux/media/v4l2-isp.h | 82 ++++++++++++++++++++++++++++++++++++++++++
 utils/update-kernel-headers.sh |  1 +
 2 files changed, 83 insertions(+)

Patch
diff mbox series

diff --git a/include/linux/media/v4l2-isp.h b/include/linux/media/v4l2-isp.h
new file mode 100644
index 0000000000000000000000000000000000000000..49b451e30d88cce7d15ab40e6a3d533c7bb7a12c
--- /dev/null
+++ b/include/linux/media/v4l2-isp.h
@@ -0,0 +1,82 @@ 
+/* 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_ISP_PARAMS_FL_BLOCK_DISABLE	(1U << 0)
+#define V4L2_ISP_PARAMS_FL_BLOCK_ENABLE	(1U << 1)
+
+/*
+ * Reserve the first 8 bits for V4L2_ISP_PARAMS_FL_* flag.
+ *
+ * Driver-specific flags should be defined as:
+ * #define DRIVER_SPECIFIC_FLAG0     ((1U << V4L2_ISP_PARAMS_FL_DRIVER_FLAGS(0))
+ * #define DRIVER_SPECIFIC_FLAG1     ((1U << V4L2_ISP_PARAMS_FL_DRIVER_FLAGS(1))
+ */
+#define V4L2_ISP_PARAMS_FL_DRIVER_FLAGS(n)       ((n) + 8)
+
+/**
+ * struct v4l2_isp_params_block_header - V4L2 extensible parameters block 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
+ *
+ * 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 @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_ISP_FL_* and
+ * driver-specific flags specified by the driver header.
+ */
+struct v4l2_isp_params_block_header {
+	__u16 type;
+	__u16 flags;
+	__u32 size;
+} __attribute__((aligned(8)));
+
+/**
+ * struct v4l2_isp_params_buffer - V4L2 extensible parameters configuration
+ * @version: The parameters buffer version (driver-specific)
+ * @data_size: The configuration data effective size, excluding this header
+ * @data: The configuration data
+ *
+ * This structure 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_isp_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. Userspace shall populate the @data_size field with the effective
+ * size, in bytes, of the @data buffer.
+ */
+struct v4l2_isp_params_buffer {
+	__u32 version;
+	__u32 data_size;
+	__u8 data[] __counted_by(data_size);
+};
+
+#endif /* _V4L2_ISP_H_ */
diff --git a/utils/update-kernel-headers.sh b/utils/update-kernel-headers.sh
index 666624f9972ea61067e5b5695237ab7a17c61664..857601df8766c6493e51b62f0f9ca551d7efbd4a 100755
--- a/utils/update-kernel-headers.sh
+++ b/utils/update-kernel-headers.sh
@@ -56,6 +56,7 @@  headers="
 	linux/udmabuf.h
 	linux/v4l2-common.h
 	linux/v4l2-controls.h
+	linux/v4l2-isp.h
 	linux/v4l2-mediabus.h
 	linux/v4l2-subdev.h
 	linux/videodev2.h