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author | Mauro Carvalho Chehab <mchehab@s-opensource.com> | 2016-07-27 13:45:04 (GMT) |
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committer | Mauro Carvalho Chehab <mchehab@s-opensource.com> | 2016-07-27 13:45:04 (GMT) |
commit | 85538b1ad145c67198cb55d02de14ba269cc323d (patch) | |
tree | 409fca93b357839b8c89b7099f2888c087694b64 /Documentation/media/uapi/mediactl/media-ioc-setup-link.rst | |
parent | 9c1958fc326a0a0a533ec8e86ea6fa30977207de (diff) | |
parent | d271d3d9b333c94cd54a12fa506e17772a04617c (diff) | |
download | linux-85538b1ad145c67198cb55d02de14ba269cc323d.tar.xz |
Merge branch 'topic/docs-next' into v4l_for_linus
* topic/docs-next: (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/mediactl/media-ioc-setup-link.rst')
-rw-r--r-- | Documentation/media/uapi/mediactl/media-ioc-setup-link.rst | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/Documentation/media/uapi/mediactl/media-ioc-setup-link.rst b/Documentation/media/uapi/mediactl/media-ioc-setup-link.rst new file mode 100644 index 0000000..e02fe23 --- /dev/null +++ b/Documentation/media/uapi/mediactl/media-ioc-setup-link.rst @@ -0,0 +1,68 @@ +.. -*- coding: utf-8; mode: rst -*- + +.. _media_ioc_setup_link: + +************************** +ioctl MEDIA_IOC_SETUP_LINK +************************** + +Name +==== + +MEDIA_IOC_SETUP_LINK - Modify the properties of a link + + +Synopsis +======== + +.. cpp:function:: int ioctl( int fd, int request, struct media_link_desc *argp ) + + +Arguments +========= + +``fd`` + File descriptor returned by :ref:`open() <media-func-open>`. + +``request`` + MEDIA_IOC_SETUP_LINK + +``argp`` + + +Description +=========== + +To change link properties applications fill a struct +:ref:`media_link_desc <media-link-desc>` with link identification +information (source and sink pad) and the new requested link flags. They +then call the MEDIA_IOC_SETUP_LINK ioctl with a pointer to that +structure. + +The only configurable property is the ``ENABLED`` link flag to +enable/disable a link. Links marked with the ``IMMUTABLE`` link flag can +not be enabled or disabled. + +Link configuration has no side effect on other links. If an enabled link +at the sink pad prevents the link from being enabled, the driver returns +with an ``EBUSY`` error code. + +Only links marked with the ``DYNAMIC`` link flag can be enabled/disabled +while streaming media data. Attempting to enable or disable a streaming +non-dynamic link will return an ``EBUSY`` error code. + +If the specified link can't be found the driver returns with an ``EINVAL`` +error code. + + +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:`media_link_desc <media-link-desc>` references a + non-existing link, or the link is immutable and an attempt to modify + its configuration was made. |