cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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vidioc-subdev-enum-mbus-code.rst (4941B)


      1.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
      2.. c:namespace:: V4L
      3
      4.. _VIDIOC_SUBDEV_ENUM_MBUS_CODE:
      5
      6**********************************
      7ioctl VIDIOC_SUBDEV_ENUM_MBUS_CODE
      8**********************************
      9
     10Name
     11====
     12
     13VIDIOC_SUBDEV_ENUM_MBUS_CODE - Enumerate media bus formats
     14
     15Synopsis
     16========
     17
     18.. c:macro:: VIDIOC_SUBDEV_ENUM_MBUS_CODE
     19
     20``int ioctl(int fd, VIDIOC_SUBDEV_ENUM_MBUS_CODE, struct v4l2_subdev_mbus_code_enum * argp)``
     21
     22Arguments
     23=========
     24
     25``fd``
     26    File descriptor returned by :c:func:`open()`.
     27
     28``argp``
     29    Pointer to struct :c:type:`v4l2_subdev_mbus_code_enum`.
     30
     31Description
     32===========
     33
     34To enumerate media bus formats available at a given sub-device pad
     35applications initialize the ``pad``, ``which`` and ``index`` fields of
     36struct
     37:c:type:`v4l2_subdev_mbus_code_enum` and
     38call the :ref:`VIDIOC_SUBDEV_ENUM_MBUS_CODE` ioctl with a pointer to this
     39structure. Drivers fill the rest of the structure or return an ``EINVAL``
     40error code if either the ``pad`` or ``index`` are invalid. All media bus
     41formats are enumerable by beginning at index zero and incrementing by
     42one until ``EINVAL`` is returned.
     43
     44Available media bus formats may depend on the current 'try' formats at
     45other pads of the sub-device, as well as on the current active links.
     46See :ref:`VIDIOC_SUBDEV_G_FMT` for more
     47information about the try formats.
     48
     49.. c:type:: v4l2_subdev_mbus_code_enum
     50
     51.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.5cm}|
     52
     53.. flat-table:: struct v4l2_subdev_mbus_code_enum
     54    :header-rows:  0
     55    :stub-columns: 0
     56    :widths:       1 1 2
     57
     58    * - __u32
     59      - ``pad``
     60      - Pad number as reported by the media controller API.
     61    * - __u32
     62      - ``index``
     63      - Number of the format in the enumeration, set by the application.
     64    * - __u32
     65      - ``code``
     66      - The media bus format code, as defined in
     67	:ref:`v4l2-mbus-format`.
     68    * - __u32
     69      - ``which``
     70      - Media bus format codes to be enumerated, from enum
     71	:ref:`v4l2_subdev_format_whence <v4l2-subdev-format-whence>`.
     72    * - __u32
     73      - ``flags``
     74      - See :ref:`v4l2-subdev-mbus-code-flags`
     75    * - __u32
     76      - ``reserved``\ [7]
     77      - Reserved for future extensions. Applications and drivers must set
     78	the array to zero.
     79
     80
     81
     82.. raw:: latex
     83
     84   \footnotesize
     85
     86.. tabularcolumns:: |p{8.8cm}|p{2.2cm}|p{6.3cm}|
     87
     88.. _v4l2-subdev-mbus-code-flags:
     89
     90.. flat-table:: Subdev Media Bus Code Enumerate Flags
     91    :header-rows:  0
     92    :stub-columns: 0
     93    :widths:       1 1 2
     94
     95    * - V4L2_SUBDEV_MBUS_CODE_CSC_COLORSPACE
     96      - 0x00000001
     97      - The driver allows the application to try to change the default colorspace
     98	encoding. The application can ask to configure the colorspace of the
     99	subdevice when calling the :ref:`VIDIOC_SUBDEV_S_FMT <VIDIOC_SUBDEV_G_FMT>`
    100	ioctl with :ref:`V4L2_MBUS_FRAMEFMT_SET_CSC <mbus-framefmt-set-csc>` set.
    101	See :ref:`v4l2-mbus-format` on how to do this.
    102    * - V4L2_SUBDEV_MBUS_CODE_CSC_XFER_FUNC
    103      - 0x00000002
    104      - The driver allows the application to try to change the default transform function.
    105	The application can ask to configure the transform function of
    106	the subdevice when calling the :ref:`VIDIOC_SUBDEV_S_FMT <VIDIOC_SUBDEV_G_FMT>`
    107	ioctl with :ref:`V4L2_MBUS_FRAMEFMT_SET_CSC <mbus-framefmt-set-csc>` set.
    108	See :ref:`v4l2-mbus-format` on how to do this.
    109    * - V4L2_SUBDEV_MBUS_CODE_CSC_YCBCR_ENC
    110      - 0x00000004
    111      - The driver allows the application to try to change the default Y'CbCr
    112	encoding. The application can ask to configure the Y'CbCr encoding of the
    113	subdevice when calling the :ref:`VIDIOC_SUBDEV_S_FMT <VIDIOC_SUBDEV_G_FMT>`
    114	ioctl with :ref:`V4L2_MBUS_FRAMEFMT_SET_CSC <mbus-framefmt-set-csc>` set.
    115	See :ref:`v4l2-mbus-format` on how to do this.
    116    * - V4L2_SUBDEV_MBUS_CODE_CSC_HSV_ENC
    117      - 0x00000004
    118      - The driver allows the application to try to change the default HSV
    119	encoding. The application can ask to configure the HSV encoding of the
    120	subdevice when calling the :ref:`VIDIOC_SUBDEV_S_FMT <VIDIOC_SUBDEV_G_FMT>`
    121	ioctl with :ref:`V4L2_MBUS_FRAMEFMT_SET_CSC <mbus-framefmt-set-csc>` set.
    122	See :ref:`v4l2-mbus-format` on how to do this.
    123    * - V4L2_SUBDEV_MBUS_CODE_CSC_QUANTIZATION
    124      - 0x00000008
    125      - The driver allows the application to try to change the default
    126	quantization. The application can ask to configure the quantization of
    127	the subdevice when calling the :ref:`VIDIOC_SUBDEV_S_FMT <VIDIOC_SUBDEV_G_FMT>`
    128	ioctl with :ref:`V4L2_MBUS_FRAMEFMT_SET_CSC <mbus-framefmt-set-csc>` set.
    129	See :ref:`v4l2-mbus-format` on how to do this.
    130
    131.. raw:: latex
    132
    133   \normalsize
    134
    135Return Value
    136============
    137
    138On success 0 is returned, on error -1 and the ``errno`` variable is set
    139appropriately. The generic error codes are described at the
    140:ref:`Generic Error Codes <gen-errors>` chapter.
    141
    142EINVAL
    143    The struct
    144    :c:type:`v4l2_subdev_mbus_code_enum`
    145    ``pad`` references a non-existing pad, or the ``index`` field is out
    146    of bounds.