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author | Mauro Carvalho Chehab <mchehab@s-opensource.com> | 2016-07-27 10:45:04 -0300 |
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committer | Mauro Carvalho Chehab <mchehab@s-opensource.com> | 2016-07-27 10:45:04 -0300 |
commit | 85538b1ad145c67198cb55d02de14ba269cc323d (patch) | |
tree | 409fca93b357839b8c89b7099f2888c087694b64 /Documentation/media/uapi/cec/cec-func-open.rst | |
parent | 9c1958fc326a0a0a533ec8e86ea6fa30977207de (diff) | |
parent | d271d3d9b333c94cd54a12fa506e17772a04617c (diff) |
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/cec/cec-func-open.rst')
-rw-r--r-- | Documentation/media/uapi/cec/cec-func-open.rst | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/Documentation/media/uapi/cec/cec-func-open.rst b/Documentation/media/uapi/cec/cec-func-open.rst new file mode 100644 index 000000000000..38fd7e0cfccd --- /dev/null +++ b/Documentation/media/uapi/cec/cec-func-open.rst @@ -0,0 +1,80 @@ +.. -*- coding: utf-8; mode: rst -*- + +.. _cec-func-open: + +********** +cec open() +********** + +Name +==== + +cec-open - Open a cec device + +Synopsis +======== + +.. code-block:: c + + #include <fcntl.h> + + +.. cpp:function:: int open( const char *device_name, int flags ) + + +Arguments +========= + +``device_name`` + Device to be opened. + +``flags`` + Open flags. Access mode must be ``O_RDWR``. + + When the ``O_NONBLOCK`` flag is given, the + :ref:`CEC_RECEIVE <CEC_RECEIVE>` and :ref:`CEC_DQEVENT <CEC_DQEVENT>` ioctls + will return the ``EAGAIN`` error code when no message or event is available, and + ioctls :ref:`CEC_TRANSMIT <CEC_TRANSMIT>`, + :ref:`CEC_ADAP_S_PHYS_ADDR <CEC_ADAP_S_PHYS_ADDR>` and + :ref:`CEC_ADAP_S_LOG_ADDRS <CEC_ADAP_S_LOG_ADDRS>` + all return 0. + + Other flags have no effect. + + +Description +=========== + +.. note:: This documents the proposed CEC API. This API is not yet finalized + and is currently only available as a staging kernel module. + +To open a cec device applications call :c:func:`open()` with the +desired device name. The function has no side effects; the device +configuration remain unchanged. + +When the device is opened in read-only mode, attempts to modify its +configuration will result in an error, and ``errno`` will be set to +EBADF. + + +Return Value +============ + +:c:func:`open()` returns the new file descriptor on success. On error, +-1 is returned, and ``errno`` is set appropriately. Possible error codes +include: + +``EACCES`` + The requested access to the file is not allowed. + +``EMFILE`` + The process already has the maximum number of files open. + +``ENFILE`` + The system limit on the total number of open files has been reached. + +``ENOMEM`` + Insufficient kernel memory was available. + +``ENXIO`` + No device corresponding to this device special file exists. |