[media] doc-rst: linux_tv CEC part, DocBook to reST migration

This is the reST migration of media's CEC part.  The migration is based
on media_tree's cec branch:

 https://git.linuxtv.org/media_tree.git

 c7169ad * cec media_tree/cec [media] DocBook/media: add CEC documentation

Signed-off-by: Markus Heiser <markus.heiser@darmarIT.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

1 files changed, 74 insertions, 0 deletions

diff --git a/Documentation/media/uapi/cec/cec-func-poll.rst b/Documentation/media/uapi/cec/cec-func-poll.rst
new file mode 100644
index 000000000000..ee559217c4f1
--- /dev/null
+++ b/Documentation/media/uapi/cec/cec-func-poll.rst
@@ -0,0 +1,74 @@
+.. -*- coding: utf-8; mode: rst -*-
+
+.. _cec-func-poll:
+
+**********
+cec poll()
+**********
+
+*man cec-poll(2)*
+
+Wait for some event on a file descriptor
+
+
+Synopsis
+========
+
+.. code-block:: c
+
+    #include <sys/poll.h>
+
+
+.. c:function:: int poll( struct pollfd *ufds, unsigned int nfds, int timeout )
+
+Description
+===========
+
+Note: this documents the proposed CEC API. This API is not yet finalized
+and is currently only available as a staging kernel module.
+
+With the :c:func:`poll()` function applications can wait for CEC
+events.
+
+On success :c:func:`poll()` returns the number of file descriptors
+that have been selected (that is, file descriptors for which the
+``revents`` field of the respective :c:type:`struct pollfd` structure
+is non-zero). CEC devices set the ``POLLIN`` and ``POLLRDNORM`` flags in
+the ``revents`` field if there are messages in the receive queue. If the
+transmit queue has room for new messages, the ``POLLOUT`` and
+``POLLWRNORM`` flags are set. If there are events in the event queue,
+then the ``POLLPRI`` flag is set. When the function timed out it returns
+a value of zero, on failure it returns -1 and the ``errno`` variable is
+set appropriately.
+
+For more details see the :c:func:`poll()` manual page.
+
+
+Return Value
+============
+
+On success, :c:func:`poll()` returns the number structures which have
+non-zero ``revents`` fields, or zero if the call timed out. On error -1
+is returned, and the ``errno`` variable is set appropriately:
+
+EBADF
+    One or more of the ``ufds`` members specify an invalid file
+    descriptor.
+
+EFAULT
+    ``ufds`` references an inaccessible memory area.
+
+EINTR
+    The call was interrupted by a signal.
+
+EINVAL
+    The ``nfds`` argument is greater than ``OPEN_MAX``.
+
+
+.. ------------------------------------------------------------------------------
+.. This file was automatically converted from DocBook-XML with the dbxml
+.. library (https://github.com/return42/sphkerneldoc). The origin XML comes
+.. from the linux kernel, refer to:
+..
+.. * https://github.com/torvalds/linux/tree/master/Documentation/DocBook
+.. ------------------------------------------------------------------------------