[v9,4/8] media: uapi: Add meta pixel format for PiSP BE config

Message ID 20240531080707.34568-5-jacopo.mondi@ideasonboard.com (mailing list archive)
State Changes Requested
Series media: raspberrypi: Add support for PiSP Back End |

Commit Message

Jacopo Mondi May 31, 2024, 8:07 a.m. UTC
  Add format description for the PiSP Back End configuration parameter

Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Reviewed-by: Naushir Patuck <naush@raspberrypi.com>
 .../userspace-api/media/v4l/meta-formats.rst  |  1 +
 .../media/v4l/metafmt-pisp-be.rst             | 56 +++++++++++++++++++
 drivers/media/v4l2-core/v4l2-ioctl.c          |  1 +
 include/uapi/linux/videodev2.h                |  3 +
 4 files changed, 61 insertions(+)
 create mode 100644 Documentation/userspace-api/media/v4l/metafmt-pisp-be.rst


diff --git a/Documentation/userspace-api/media/v4l/meta-formats.rst b/Documentation/userspace-api/media/v4l/meta-formats.rst
index c23aac823d2c..c6e56b5888bc 100644
--- a/Documentation/userspace-api/media/v4l/meta-formats.rst
+++ b/Documentation/userspace-api/media/v4l/meta-formats.rst
@@ -15,6 +15,7 @@  These formats are used for the :ref:`metadata` interface only.
+    metafmt-pisp-be
diff --git a/Documentation/userspace-api/media/v4l/metafmt-pisp-be.rst b/Documentation/userspace-api/media/v4l/metafmt-pisp-be.rst
new file mode 100644
index 000000000000..3281fe366c86
--- /dev/null
+++ b/Documentation/userspace-api/media/v4l/metafmt-pisp-be.rst
@@ -0,0 +1,56 @@ 
+.. SPDX-License-Identifier: GPL-2.0
+.. _v4l2-meta-fmt-rpi-be-cfg:
+Raspberry Pi PiSP Back End configuration format
+The Raspberry Pi PiSP Back End memory-to-memory image signal processor is
+configured by userspace by providing a buffer of configuration parameters
+to the `pispbe-config` output video device node using the
+:c:type:`v4l2_meta_format` interface.
+The PiSP Back End processes images in tiles, and its configuration requires
+specifying two different sets of parameters by populating the members of
+:c:type:`pisp_be_tiles_config` defined in the ``pisp_be_config.h`` header file.
+The `Raspberry Pi PiSP technical specification
+provide detailed description of the ISP back end configuration and programming
+Global configuration data
+The global configuration data describe how the pixels in a particular image are
+to be processed and is therefore shared across all the tiles of the image. So
+for example, LSC (Lens Shading Correction) or Denoise parameters would be common
+across all tiles from the same frame.
+Global configuration data are passed to the ISP by populating the member of
+Tile parameters
+As the ISP processes images in tiles, each set of tiles parameters describe how
+a single tile in an image is going to be processed. A single set of tile
+parameters consist of 160 bytes of data and to process a batch of tiles several
+sets of tiles parameters are required.
+Tiles parameters are passed to the ISP by populating the member of
+``pisp_tile`` and the ``num_tiles`` fields of :c:type:`pisp_be_tiles_config`.
+Raspberry Pi PiSP Back End uAPI data types
+This section describes the data types exposed to userspace by the Raspberry Pi
+PiSP Back End. The section is informative only, for a detailed description of
+each field refer to the `Raspberry Pi PiSP technical specification
+.. kernel-doc:: include/uapi/linux/media/raspberrypi/pisp_be_config.h
diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
index ee97643ff3a7..7c684788997c 100644
--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c
@@ -1465,6 +1465,7 @@  static void v4l_fill_fmtdesc(struct v4l2_fmtdesc *fmt)
 	case V4L2_PIX_FMT_Y210:		descr = "10-bit YUYV Packed"; break;
 	case V4L2_PIX_FMT_Y212:		descr = "12-bit YUYV Packed"; break;
 	case V4L2_PIX_FMT_Y216:		descr = "16-bit YUYV Packed"; break;
+	case V4L2_META_FMT_RPI_BE_CFG:	descr = "RPi PiSP BE Config format"; break;
 	case V4L2_META_FMT_GENERIC_8:	descr = "8-bit Generic Metadata"; break;
 	case V4L2_META_FMT_GENERIC_CSI2_10:	descr = "8-bit Generic Meta, 10b CSI-2"; break;
 	case V4L2_META_FMT_GENERIC_CSI2_12:	descr = "8-bit Generic Meta, 12b CSI-2"; break;
diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index dd6876380fe3..96fc0456081e 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -843,6 +843,9 @@  struct v4l2_pix_format {
 #define V4L2_META_FMT_RK_ISP1_PARAMS	v4l2_fourcc('R', 'K', '1', 'P') /* Rockchip ISP1 3A Parameters */
 #define V4L2_META_FMT_RK_ISP1_STAT_3A	v4l2_fourcc('R', 'K', '1', 'S') /* Rockchip ISP1 3A Statistics */
+/* Vendor specific - used for RaspberryPi PiSP */
+#define V4L2_META_FMT_RPI_BE_CFG	v4l2_fourcc('R', 'P', 'B', 'C') /* PiSP BE configuration */
 #ifdef __KERNEL__
  * Line-based metadata formats. Remember to update v4l_fill_fmtdesc() when