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54f38fcae5
Since 2017, there is an space reserved for userspace API,
created by changeset 1d596dee38
("docs: Create a user-space API guide").
As the media subsystem was one of the first subsystems to use
Sphinx, until this patch, we were keeping things on a separate
place.
Let's just use the new location, as having all uAPI altogether
will likely make things easier for developers.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
99 lines
2.8 KiB
ReStructuredText
99 lines
2.8 KiB
ReStructuredText
.. Permission is granted to copy, distribute and/or modify this
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.. document under the terms of the GNU Free Documentation License,
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.. Version 1.1 or any later version published by the Free Software
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.. Foundation, with no Invariant Sections, no Front-Cover Texts
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.. and no Back-Cover Texts. A copy of the license is included at
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.. Documentation/userspace-api/media/fdl-appendix.rst.
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..
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.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections
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.. _VIDIOC_SUBDEV_ENUM_MBUS_CODE:
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**********************************
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ioctl VIDIOC_SUBDEV_ENUM_MBUS_CODE
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**********************************
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Name
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====
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VIDIOC_SUBDEV_ENUM_MBUS_CODE - Enumerate media bus formats
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Synopsis
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========
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.. c:function:: int ioctl( int fd, VIDIOC_SUBDEV_ENUM_MBUS_CODE, struct v4l2_subdev_mbus_code_enum * argp )
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:name: VIDIOC_SUBDEV_ENUM_MBUS_CODE
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Arguments
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=========
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``fd``
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File descriptor returned by :ref:`open() <func-open>`.
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``argp``
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Pointer to struct :c:type:`v4l2_subdev_mbus_code_enum`.
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Description
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===========
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To enumerate media bus formats available at a given sub-device pad
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applications initialize the ``pad``, ``which`` and ``index`` fields of
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struct
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:c:type:`v4l2_subdev_mbus_code_enum` and
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call the :ref:`VIDIOC_SUBDEV_ENUM_MBUS_CODE` ioctl with a pointer to this
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structure. Drivers fill the rest of the structure or return an ``EINVAL``
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error code if either the ``pad`` or ``index`` are invalid. All media bus
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formats are enumerable by beginning at index zero and incrementing by
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one until ``EINVAL`` is returned.
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Available media bus formats may depend on the current 'try' formats at
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other pads of the sub-device, as well as on the current active links.
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See :ref:`VIDIOC_SUBDEV_G_FMT` for more
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information about the try formats.
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.. c:type:: v4l2_subdev_mbus_code_enum
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.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}|
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.. flat-table:: struct v4l2_subdev_mbus_code_enum
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:header-rows: 0
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:stub-columns: 0
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:widths: 1 1 2
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* - __u32
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- ``pad``
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- Pad number as reported by the media controller API.
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* - __u32
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- ``index``
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- Number of the format in the enumeration, set by the application.
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* - __u32
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- ``code``
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- The media bus format code, as defined in
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:ref:`v4l2-mbus-format`.
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* - __u32
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- ``which``
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- Media bus format codes to be enumerated, from enum
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:ref:`v4l2_subdev_format_whence <v4l2-subdev-format-whence>`.
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* - __u32
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- ``reserved``\ [8]
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- Reserved for future extensions. Applications and drivers must set
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the array to zero.
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Return Value
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============
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On success 0 is returned, on error -1 and the ``errno`` variable is set
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appropriately. The generic error codes are described at the
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:ref:`Generic Error Codes <gen-errors>` chapter.
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EINVAL
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The struct
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:c:type:`v4l2_subdev_mbus_code_enum`
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``pad`` references a non-existing pad, or the ``index`` field is out
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of bounds.
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