diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-07-27 14:58:31 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-07-27 14:58:31 -0700 |
commit | ff9a082fda424257976f08fce942609f358015e0 (patch) | |
tree | 478e6b449b19baaf842369a13923499ce83ef895 /Documentation/media/uapi/v4l/vidioc-g-std.rst | |
parent | 6a492b0f23d28e1f946cdf08e54617484400dafb (diff) | |
parent | 85538b1ad145c67198cb55d02de14ba269cc323d (diff) | |
download | linux-ff9a082fda424257976f08fce942609f358015e0.tar.gz |
Merge tag 'media/v4.8-4' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media
Pull media documentation updates from Mauro Carvalho Chehab:
"This patch series does the conversion of all media documentation stuff
to Restrutured Text markup format and add them to the
Documentation/index.rst file.
The media documentation was grouped into 4 books:
- media uAPI
- media kAPI
- V4L driver-specific documentation
- DVB driver-specific documentation
It also contains several documentation improvements and one fixup
patch for a core issue with cropcap.
PS. After this patch series, the media DocBook is deprecated and
should be removed. I'll add such patch on a future pull request"
* tag 'media/v4.8-4' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (322 commits)
[media] cx23885-cardlist.rst: add a new card
[media] doc-rst: add some needed escape codes
[media] doc-rst: kapi: use :c:func: instead of :cpp:func
doc-rst: kernel-doc: fix a change introduced by mistake
[media] v4l2-ioctl.h add debug info for struct v4l2_ioctl_ops
[media] dvb_ringbuffer.h: some documentation improvements
[media] v4l2-ctrls.h: fully document the header file
[media] doc-rst: Fix some typedef ugly warnings
[media] doc-rst: reorganize the kAPI v4l2 chapters
[media] rename v4l2-framework.rst to v4l2-intro.rst
[media] move V4L2 clocks to a separate .rst file
[media] v4l2-fh.rst: add cross references and markups
[media] v4l2-fh.rst: add fh contents from v4l2-framework.rst
[media] v4l2-fh.h: add documentation for it
[media] v4l2-event.rst: add cross-references and markups
[media] v4l2-event.h: document all functions
[media] v4l2-event.rst: add text from v4l2-framework.rst
[media] v4l2-framework.rst: remove videobuf quick chapter
[media] v4l2-dev: add cross-references and improve markup
[media] doc-rst: move v4l2-dev doc to a separate file
...
Diffstat (limited to 'Documentation/media/uapi/v4l/vidioc-g-std.rst')
-rw-r--r-- | Documentation/media/uapi/v4l/vidioc-g-std.rst | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/Documentation/media/uapi/v4l/vidioc-g-std.rst b/Documentation/media/uapi/v4l/vidioc-g-std.rst new file mode 100644 index 000000000000..5c2b861f8d26 --- /dev/null +++ b/Documentation/media/uapi/v4l/vidioc-g-std.rst @@ -0,0 +1,68 @@ +.. -*- coding: utf-8; mode: rst -*- + +.. _VIDIOC_G_STD: + +******************************** +ioctl VIDIOC_G_STD, VIDIOC_S_STD +******************************** + +Name +==== + +VIDIOC_G_STD - VIDIOC_S_STD - Query or select the video standard of the current input + + +Synopsis +======== + +.. cpp:function:: int ioctl( int fd, int request, v4l2_std_id *argp ) + +.. cpp:function:: int ioctl( int fd, int request, const v4l2_std_id *argp ) + + +Arguments +========= + +``fd`` + File descriptor returned by :ref:`open() <func-open>`. + +``request`` + VIDIOC_G_STD, VIDIOC_S_STD + +``argp`` + + +Description +=========== + +To query and select the current video standard applications use the +:ref:`VIDIOC_G_STD <VIDIOC_G_STD>` and :ref:`VIDIOC_S_STD <VIDIOC_G_STD>` ioctls which take a pointer to a +:ref:`v4l2_std_id <v4l2-std-id>` type as argument. :ref:`VIDIOC_G_STD <VIDIOC_G_STD>` +can return a single flag or a set of flags as in struct +:ref:`v4l2_standard <v4l2-standard>` field ``id``. The flags must be +unambiguous such that they appear in only one enumerated +:ref:`struct v4l2_standard <v4l2-standard>` structure. + +:ref:`VIDIOC_S_STD <VIDIOC_G_STD>` accepts one or more flags, being a write-only ioctl it +does not return the actual new standard as :ref:`VIDIOC_G_STD <VIDIOC_G_STD>` does. When +no flags are given or the current input does not support the requested +standard the driver returns an ``EINVAL`` error code. When the standard set +is ambiguous drivers may return ``EINVAL`` or choose any of the requested +standards. If the current input or output does not support standard +video timings (e.g. if :ref:`VIDIOC_ENUMINPUT` +does not set the ``V4L2_IN_CAP_STD`` flag), then ``ENODATA`` error code is +returned. + + +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 :ref:`VIDIOC_S_STD <VIDIOC_G_STD>` parameter was unsuitable. + +ENODATA + Standard video timings are not supported for this input or output. |