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 .. cpp:function:: int ioctl( int fd, int request, struct v4l2_subdev_mbus_code_enum * argp )
  19
  20
  21 Arguments
  22 =========
  23
  24 ``fd``
  25     File descriptor returned by :ref:`open() <func-open>`.
  26
  27 ``request``
  28     VIDIOC_SUBDEV_ENUM_MBUS_CODE
  29
  30 ``argp``
  31
  32
  33 Description
  34 ===========
  35
  36 To enumerate media bus formats available at a given sub-device pad
  37 applications initialize the ``pad``, ``which`` and ``index`` fields of
  38 struct
  39 :ref:`v4l2_subdev_mbus_code_enum <v4l2-subdev-mbus-code-enum>` and
  40 call the :ref:`VIDIOC_SUBDEV_ENUM_MBUS_CODE` ioctl with a pointer to this
  41 structure. Drivers fill the rest of the structure or return an ``EINVAL``
  42 error code if either the ``pad`` or ``index`` are invalid. All media bus
  43 formats are enumerable by beginning at index zero and incrementing by
  44 one until ``EINVAL`` is returned.
  45
  46 Available media bus formats may depend on the current 'try' formats at
  47 other pads of the sub-device, as well as on the current active links.
  48 See :ref:`VIDIOC_SUBDEV_G_FMT` for more
  49 information about the try formats.
  50
  51
  52 .. _v4l2-subdev-mbus-code-enum:
  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     :ref:`v4l2_subdev_mbus_code_enum <v4l2-subdev-mbus-code-enum>`
 114     ``pad`` references a non-existing pad, or the ``index`` field is out
 115     of bounds.