diff options
author | Mauro Carvalho Chehab <mchehab+huawei@kernel.org> | 2020-03-04 10:21:39 +0100 |
---|---|---|
committer | Mauro Carvalho Chehab <mchehab+huawei@kernel.org> | 2020-04-14 10:31:49 +0200 |
commit | 54f38fcae536ea202ce7d6a359521492fba30c1f (patch) | |
tree | dd1a2b36d8de0b13702f2716526ad3b91650e090 /Documentation/userspace-api/media/v4l/vidioc-enumaudio.rst | |
parent | 5dfb8db56b273740a76e8687ee7efb4b2c0ec83b (diff) |
media: docs: move uAPI book to userspace-api/media
Since 2017, there is an space reserved for userspace API,
created by changeset 1d596dee3862 ("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>
Diffstat (limited to 'Documentation/userspace-api/media/v4l/vidioc-enumaudio.rst')
-rw-r--r-- | Documentation/userspace-api/media/v4l/vidioc-enumaudio.rst | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/Documentation/userspace-api/media/v4l/vidioc-enumaudio.rst b/Documentation/userspace-api/media/v4l/vidioc-enumaudio.rst new file mode 100644 index 000000000000..afe4821e5863 --- /dev/null +++ b/Documentation/userspace-api/media/v4l/vidioc-enumaudio.rst @@ -0,0 +1,62 @@ +.. Permission is granted to copy, distribute and/or modify this +.. document under the terms of the GNU Free Documentation License, +.. Version 1.1 or any later version published by the Free Software +.. Foundation, with no Invariant Sections, no Front-Cover Texts +.. and no Back-Cover Texts. A copy of the license is included at +.. Documentation/userspace-api/media/fdl-appendix.rst. +.. +.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections + +.. _VIDIOC_ENUMAUDIO: + +********************** +ioctl VIDIOC_ENUMAUDIO +********************** + +Name +==== + +VIDIOC_ENUMAUDIO - Enumerate audio inputs + + +Synopsis +======== + +.. c:function:: int ioctl( int fd, VIDIOC_ENUMAUDIO, struct v4l2_audio *argp ) + :name: VIDIOC_ENUMAUDIO + + +Arguments +========= + +``fd`` + File descriptor returned by :ref:`open() <func-open>`. + +``argp`` + Pointer to struct :c:type:`v4l2_audio`. + + +Description +=========== + +To query the attributes of an audio input applications initialize the +``index`` field and zero out the ``reserved`` array of a struct +:c:type:`v4l2_audio` and call the :ref:`VIDIOC_ENUMAUDIO` +ioctl with a pointer to this structure. Drivers fill the rest of the +structure or return an ``EINVAL`` error code when the index is out of +bounds. To enumerate all audio inputs applications shall begin at index +zero, incrementing by one until the driver returns ``EINVAL``. + +See :ref:`VIDIOC_G_AUDIO <VIDIOC_G_AUDIO>` for a description of struct +:c:type:`v4l2_audio`. + + +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 number of the audio input is out of bounds. |