Documentation/admin-guide/media/bcm2835-isp.rst

   1 .. SPDX-License-Identifier: GPL-2.0
   2
   3 BCM2835 ISP Driver
   4 ==================
   5
   6 Introduction
   7 ------------
   8
   9 The BCM2835 Image Sensor Pipeline (ISP) is a fixed function hardware pipeline
  10 for performing image processing operations.  Images are fed to the input
  11 of the ISP through memory frame buffers.  These images may be in various YUV,
  12 RGB, or Bayer formats.  A typical use case would have Bayer images obtained from
  13 an image sensor by the BCM2835 Unicam peripheral, written to a memory
  14 frame buffer, and finally fed into the input of the ISP.  Two concurrent output
  15 images may be generated in YUV or RGB format at different resolutions.
  16 Statistics output is also generated for Bayer input images.
  17
  18 The bcm2835-isp driver exposes the following media pads as V4L2 device nodes:
  19
  20 .. tabularcolumns:: |l|l|l|l|
  21
  22 .. cssclass: longtable
  23
  24 .. flat-table::
  25
  26     * - *Pad*
  27       - *Direction*
  28       - *Purpose*
  29       - *Formats*
  30
  31     * - "bcm2835-isp0-output0"
  32       - sink
  33       - Accepts Bayer, RGB or YUV format frame buffers as input to the ISP HW
  34         pipeline.
  35       - :ref:`RAW8 <V4L2-PIX-FMT-SRGGB8>`,
  36         :ref:`RAW10P <V4L2-PIX-FMT-SRGGB10P>`,
  37         :ref:`RAW12P <V4L2-PIX-FMT-SRGGB12P>`,
  38         :ref:`RAW14P <V4L2-PIX-FMT-SRGGB14P>`,
  39         :ref:`RAW16 <V4L2-PIX-FMT-SRGGB16>`,
  40         :ref:`RGB24/BGR24 <V4L2-PIX-FMT-RGB24>`,
  41         :ref:`YUYV <V4L2-PIX-FMT-YUYV>`,
  42         :ref:`YVYU <V4L2-PIX-FMT-YVYU>`,
  43         :ref:`UYVY <V4L2-PIX-FMT-UYVY>`,
  44         :ref:`VYUY <V4L2-PIX-FMT-VYUY>`,
  45         :ref:`YUV420/YVU420 <V4L2-PIX-FMT-YUV420>`
  46
  47     * - "bcm2835-isp0-capture1"
  48       - source
  49       - High resolution YUV or RGB processed output from the ISP.
  50       - :ref:`RGB565 <V4L2-PIX-FMT-RGB565>`,
  51         :ref:`RGB24/BGR24 <V4L2-PIX-FMT-RGB24>`,
  52         :ref:`ABGR32 <V4L2-PIX-FMT-ABGR32>`,
  53         :ref:`YUYV <V4L2-PIX-FMT-YUYV>`,
  54         :ref:`YVYU <V4L2-PIX-FMT-YVYU>`,
  55         :ref:`UYVY <V4L2-PIX-FMT-UYVY>`,
  56         :ref:`VYUY <V4L2-PIX-FMT-VYUY>`.
  57         :ref:`YUV420/YVU420 <V4L2-PIX-FMT-YUV420>`,
  58         :ref:`NV12/NV21 <V4L2-PIX-FMT-NV12>`,
  59
  60     * - "bcm2835-isp0-capture2"
  61       - source
  62       - Low resolution YUV processed output from the ISP. The output of
  63         this pad cannot have a resolution larger than the "bcm2835-isp0-capture1" pad in any dimension.
  64       - :ref:`YUYV <V4L2-PIX-FMT-YUYV>`,
  65         :ref:`YVYU <V4L2-PIX-FMT-YVYU>`,
  66         :ref:`UYVY <V4L2-PIX-FMT-UYVY>`,
  67         :ref:`VYUY <V4L2-PIX-FMT-VYUY>`.
  68         :ref:`YUV420/YVU420 <V4L2-PIX-FMT-YUV420>`,
  69         :ref:`NV12/NV21 <V4L2-PIX-FMT-NV12>`,
  70
  71     * - "bcm2835-isp0-capture1"
  72       - source
  73       - Image statistics calculated from the input image provided on the
  74         "bcm2835-isp0-output0" pad.  Statistics are only available for Bayer
  75         format input images.
  76       - :ref:`v4l2-meta-fmt-bcm2835-isp-stats`.
  77
  78 Pipeline Configuration
  79 ----------------------
  80
  81 The ISP pipeline can be configure through user-space by calling
  82 :ref:`VIDIOC_S_EXT_CTRLS <VIDIOC_G_EXT_CTRLS>` on the “bcm2835-isp0-output0”
  83 node with the appropriate parameters as shown in the table below.
  84
  85 .. tabularcolumns:: |p{2cm}|p{5.0cm}|
  86
  87 .. cssclass: longtable
  88
  89 .. flat-table::
  90
  91     * - *id*
  92       - *Parameter*
  93
  94     * - ``V4L2_CID_USER_BCM2835_ISP_CC_MATRIX``
  95       - struct :c:type:`bcm2835_isp_custom_ccm`
  96
  97     * - ``V4L2_CID_USER_BCM2835_ISP_LENS_SHADING``
  98       - struct :c:type:`bcm2835_isp_lens_shading`
  99
 100     * - ``V4L2_CID_USER_BCM2835_ISP_BLACK_LEVEL``
 101       - struct :c:type:`bcm2835_isp_black_level`
 102
 103     * - ``V4L2_CID_USER_BCM2835_ISP_GEQ``
 104       - struct :c:type:`bcm2835_isp_geq`
 105
 106     * - ``V4L2_CID_USER_BCM2835_ISP_GAMMA``
 107       - struct :c:type:`bcm2835_isp_gamma`
 108
 109     * - ``V4L2_CID_USER_BCM2835_ISP_DENOISE``
 110       - struct :c:type:`bcm2835_isp_denoise`
 111
 112     * - ``V4L2_CID_USER_BCM2835_ISP_SHARPEN``
 113       - struct :c:type:`bcm2835_isp_sharpen`
 114
 115     * - ``V4L2_CID_USER_BCM2835_ISP_DPC``
 116       - struct :c:type:`bcm2835_isp_dpc`
 117
 118 ++++++++++++++++++++++++
 119 Configuration Parameters
 120 ++++++++++++++++++++++++
 121
 122 .. kernel-doc:: include/uapi/linux/bcm2835-isp.h
 123    :functions: bcm2835_isp_rational bcm2835_isp_ccm bcm2835_isp_custom_ccm
 124                 bcm2835_isp_gain_format bcm2835_isp_lens_shading
 125                 bcm2835_isp_black_level bcm2835_isp_geq bcm2835_isp_gamma
 126                 bcm2835_isp_denoise bcm2835_isp_sharpen
 127                 bcm2835_isp_dpc_mode bcm2835_isp_dpc