linux/Documentation/media/uapi/v4l/vidioc-subdev-enum-mbus-cod...

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ReStructuredText

.. -*- coding: utf-8; mode: rst -*-
.. _VIDIOC_SUBDEV_ENUM_MBUS_CODE:
**********************************
ioctl VIDIOC_SUBDEV_ENUM_MBUS_CODE
**********************************
Name
====
VIDIOC_SUBDEV_ENUM_MBUS_CODE - Enumerate media bus formats
Synopsis
========
.. c:function:: int ioctl( int fd, int request, struct v4l2_subdev_mbus_code_enum * argp )
Arguments
=========
``fd``
File descriptor returned by :ref:`open() <func-open>`.
``request``
VIDIOC_SUBDEV_ENUM_MBUS_CODE
``argp``
Description
===========
To enumerate media bus formats available at a given sub-device pad
applications initialize the ``pad``, ``which`` and ``index`` fields of
struct
:ref:`v4l2_subdev_mbus_code_enum <v4l2-subdev-mbus-code-enum>` and
call the :ref:`VIDIOC_SUBDEV_ENUM_MBUS_CODE` ioctl with a pointer to this
structure. Drivers fill the rest of the structure or return an ``EINVAL``
error code if either the ``pad`` or ``index`` are invalid. All media bus
formats are enumerable by beginning at index zero and incrementing by
one until ``EINVAL`` is returned.
Available media bus formats may depend on the current 'try' formats at
other pads of the sub-device, as well as on the current active links.
See :ref:`VIDIOC_SUBDEV_G_FMT` for more
information about the try formats.
.. _v4l2-subdev-mbus-code-enum:
.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}|
.. flat-table:: struct v4l2_subdev_mbus_code_enum
:header-rows: 0
:stub-columns: 0
:widths: 1 1 2
- .. row 1
- __u32
- ``pad``
- Pad number as reported by the media controller API.
- .. row 2
- __u32
- ``index``
- Number of the format in the enumeration, set by the application.
- .. row 3
- __u32
- ``code``
- The media bus format code, as defined in
:ref:`v4l2-mbus-format`.
- .. row 4
- __u32
- ``which``
- Media bus format codes to be enumerated, from enum
:ref:`v4l2_subdev_format_whence <v4l2-subdev-format-whence>`.
- .. row 5
- __u32
- ``reserved``\ [8]
- Reserved for future extensions. Applications and drivers must set
the array to zero.
Return Value
============
On success 0 is returned, on error -1 and the ``errno`` variable is set
appropriately. The generic error codes are described at the
:ref:`Generic Error Codes <gen-errors>` chapter.
EINVAL
The struct
:ref:`v4l2_subdev_mbus_code_enum <v4l2-subdev-mbus-code-enum>`
``pad`` references a non-existing pad, or the ``index`` field is out
of bounds.