Documentation/media/uapi/v4l/vidioc-subdev-enum-mbus-code.rst

   1 .. -*- coding: utf-8; mode: rst -*-
   2
   3 .. _VIDIOC_SUBDEV_ENUM_MBUS_CODE:
   4
   5 **********************************
   6 ioctl VIDIOC_SUBDEV_ENUM_MBUS_CODE
   7 **********************************
   8
   9 Name
  10 ====
  11
  12 VIDIOC_SUBDEV_ENUM_MBUS_CODE - Enumerate media bus formats
  13
  14
  15 Synopsis
  16 ========
  17
  18 .. c:function:: int ioctl( int fd, VIDIOC_SUBDEV_ENUM_MBUS_CODE, struct v4l2_subdev_mbus_code_enum * argp )
  19     :name: VIDIOC_SUBDEV_ENUM_MBUS_CODE
  20
  21
  22 Arguments
  23 =========
  24
  25 ``fd``
  26     File descriptor returned by :ref:`open() <func-open>`.
  27
  28 ``argp``
  29
  30
  31 Description
  32 ===========
  33
  34 To enumerate media bus formats available at a given sub-device pad
  35 applications initialize the ``pad``, ``which`` and ``index`` fields of
  36 struct
  37 :c:type:`v4l2_subdev_mbus_code_enum` and
  38 call the :ref:`VIDIOC_SUBDEV_ENUM_MBUS_CODE` ioctl with a pointer to this
  39 structure. Drivers fill the rest of the structure or return an ``EINVAL``
  40 error code if either the ``pad`` or ``index`` are invalid. All media bus
  41 formats are enumerable by beginning at index zero and incrementing by
  42 one until ``EINVAL`` is returned.
  43
  44 Available media bus formats may depend on the current 'try' formats at
  45 other pads of the sub-device, as well as on the current active links.
  46 See :ref:`VIDIOC_SUBDEV_G_FMT` for more
  47 information about the try formats.
  48
  49
  50 .. c:type:: v4l2_subdev_mbus_code_enum
  51
  52 .. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}|
  53
  54 .. flat-table:: struct v4l2_subdev_mbus_code_enum
  55     :header-rows:  0
  56     :stub-columns: 0
  57     :widths:       1 1 2
  58
  59
  60     -  .. row 1
  61
  62        -  __u32
  63
  64        -  ``pad``
  65
  66        -  Pad number as reported by the media controller API.
  67
  68     -  .. row 2
  69
  70        -  __u32
  71
  72        -  ``index``
  73
  74        -  Number of the format in the enumeration, set by the application.
  75
  76     -  .. row 3
  77
  78        -  __u32
  79
  80        -  ``code``
  81
  82        -  The media bus format code, as defined in
  83           :ref:`v4l2-mbus-format`.
  84
  85     -  .. row 4
  86
  87        -  __u32
  88
  89        -  ``which``
  90
  91        -  Media bus format codes to be enumerated, from enum
  92           :ref:`v4l2_subdev_format_whence <v4l2-subdev-format-whence>`.
  93
  94     -  .. row 5
  95
  96        -  __u32
  97
  98        -  ``reserved``\ [8]
  99
 100        -  Reserved for future extensions. Applications and drivers must set
 101           the array to zero.
 102
 103
 104 Return Value
 105 ============
 106
 107 On success 0 is returned, on error -1 and the ``errno`` variable is set
 108 appropriately. The generic error codes are described at the
 109 :ref:`Generic Error Codes <gen-errors>` chapter.
 110
 111 EINVAL
 112     The struct
 113     :c:type:`v4l2_subdev_mbus_code_enum`
 114     ``pad`` references a non-existing pad, or the ``index`` field is out
 115     of bounds.