git.ipfire.org Git - thirdparty/openwrt.git/blob

   1 From 7ca73020a5b26599d539083e413784e79891107e Mon Sep 17 00:00:00 2001
   2 From: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
   3 Date: Fri, 26 Jan 2024 15:04:59 +0100
   4 Subject: [PATCH 1150/1215] media: uapi: Document meta pixel format for PiSP BE
   5  config
   6
   7 Add format description for the PiSP Back End configuration parameter
   8 buffer.
   9
  10 Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
  11 Reviewed-by: Naushir Patuck <naush@raspberrypi.com>
  12 ---
  13  .../userspace-api/media/v4l/meta-formats.rst  |  1 +
  14  .../media/v4l/metafmt-pisp-be.rst             | 56 +++++++++++++++++++
  15  2 files changed, 57 insertions(+)
  16  create mode 100644 Documentation/userspace-api/media/v4l/metafmt-pisp-be.rst
  17
  18 --- a/Documentation/userspace-api/media/v4l/meta-formats.rst
  19 +++ b/Documentation/userspace-api/media/v4l/meta-formats.rst
  20 @@ -15,6 +15,7 @@ These formats are used for the :ref:`met
  21      metafmt-bcm2835-isp-stats
  22      metafmt-d4xx
  23      metafmt-intel-ipu3
  24 +    metafmt-pisp-be
  25      metafmt-rkisp1
  26      metafmt-sensor-data
  27      metafmt-uvc
  28 --- /dev/null
  29 +++ b/Documentation/userspace-api/media/v4l/metafmt-pisp-be.rst
  30 @@ -0,0 +1,56 @@
  31 +.. SPDX-License-Identifier: GPL-2.0
  32 +
  33 +.. _v4l2-meta-fmt-rpi-be-cfg:
  34 +
  35 +************************
  36 +V4L2_META_FMT_RPI_BE_CFG
  37 +************************
  38 +
  39 +Raspberry Pi PiSP Back End configuration format
  40 +===============================================
  41 +
  42 +The Raspberry Pi PiSP Back End memory-to-memory image signal processor is
  43 +configured by userspace by providing a buffer of configuration parameters
  44 +to the `pispbe-config` output video device node using the
  45 +:c:type:`v4l2_meta_format` interface.
  46 +
  47 +The PiSP Back End processes images in tiles, and its configuration requires
  48 +specifying two different sets of parameters by populating the members of
  49 +:c:type:`pisp_be_tiles_config` defined in the ``pisp_be_config.h`` header file.
  50 +
  51 +The `Raspberry Pi PiSP technical specification
  52 +<https://datasheets.raspberrypi.com/camera/raspberry-pi-image-signal-processor-specification.pdf>`_
  53 +provide detailed description of the ISP back end configuration and programming
  54 +model.
  55 +
  56 +Global configuration data
  57 +-------------------------
  58 +
  59 +The global configuration data describe how the pixels in a particular image are
  60 +to be processed and is therefore shared across all the tiles of the image. So
  61 +for example, LSC (Lens Shading Correction) or Denoise parameters would be common
  62 +across all tiles from the same frame.
  63 +
  64 +Global configuration data are passed to the ISP by populating the member of
  65 +:c:type:`pisp_be_config`.
  66 +
  67 +Tile parameters
  68 +---------------
  69 +
  70 +As the ISP processes images in tiles, each set of tiles parameters describe how
  71 +a single tile in an image is going to be processed. A single set of tile
  72 +parameters consist of 160 bytes of data and to process a batch of tiles several
  73 +sets of tiles parameters are required.
  74 +
  75 +Tiles parameters are passed to the ISP by populating the member of
  76 +``pisp_tile`` and the ``num_tiles`` fields of :c:type:`pisp_be_tiles_config`.
  77 +
  78 +Raspberry Pi PiSP Back End uAPI data types
  79 +==========================================
  80 +
  81 +This section describes the data types exposed to userspace by the Raspberry Pi
  82 +PiSP Back End. The section is informative only, for a detailed description of
  83 +each field refer to the `Raspberry Pi PiSP technical specification
  84 +<https://datasheets.raspberrypi.com/camera/raspberry-pi-image-signal-processor-specification.pdf>`_.
  85 +
  86 +.. kernel-doc:: include/uapi/linux/media/raspberrypi/pisp_be_config.h