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+.. 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
+
+.. _CA_SEND_MSG:
+
+===========
+CA_SEND_MSG
+===========
+
+Name
+----
+
+CA_SEND_MSG
+
+
+Synopsis
+--------
+
+.. c:function:: int ioctl(fd, CA_SEND_MSG, struct ca_msg *msg)
+    :name: CA_SEND_MSG
+
+
+Arguments
+---------
+
+``fd``
+  File descriptor returned by a previous call to :c:func:`open() <cec-open>`.
+
+``msg``
+  Pointer to struct :c:type:`ca_msg`.
+
+
+Description
+-----------
+
+Sends a message via a CI CA module.
+
+.. note::
+
+   Please notice that, on most drivers, this is done by writing
+   to the /dev/adapter?/ca? device node.
+
+Return Value
+------------
+
+On success 0 is returned.
+
+On error -1 is returned, and the ``errno`` variable is set
+appropriately.
+
+Generic error codes are described at the
+:ref:`Generic Error Codes <gen-errors>` chapter.