linux-stable/Documentation/userspace-api/media/dvb/ca-get-msg.rst
Mauro Carvalho Chehab f9b2e8aa32 media: docs: make DVB documents more compatible with Sphinx 3.1+
Sphinx 3.x broke support for the cdomain.py extension, as the
c domain code was rewritten. Due to that, the c tags need to
be re-written, in order to use the new c domain notation.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-10-15 07:49:39 +02:00

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.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
.. c:namespace:: DTV.ca
.. _CA_GET_MSG:
==========
CA_GET_MSG
==========
Name
----
CA_GET_MSG
Synopsis
--------
.. c:macro:: CA_GET_MSG
``int ioctl(fd, CA_GET_MSG, struct ca_msg *msg)``
Arguments
---------
``fd``
File descriptor returned by a previous call to :c:func:`open()`.
``msg``
Pointer to struct :c:type:`ca_msg`.
Description
-----------
Receives a message via a CI CA module.
.. note::
Please notice that, on most drivers, this is done by reading from
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.