summaryrefslogtreecommitdiffstats
path: root/Documentation/userspace-api/media/cec/cec-func-ioctl.rst
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /Documentation/userspace-api/media/cec/cec-func-ioctl.rst
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'Documentation/userspace-api/media/cec/cec-func-ioctl.rst')
-rw-r--r--Documentation/userspace-api/media/cec/cec-func-ioctl.rst63
1 files changed, 63 insertions, 0 deletions
diff --git a/Documentation/userspace-api/media/cec/cec-func-ioctl.rst b/Documentation/userspace-api/media/cec/cec-func-ioctl.rst
new file mode 100644
index 000000000..7c93f86de
--- /dev/null
+++ b/Documentation/userspace-api/media/cec/cec-func-ioctl.rst
@@ -0,0 +1,63 @@
+.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
+.. c:namespace:: CEC
+
+.. _cec-func-ioctl:
+
+***********
+cec ioctl()
+***********
+
+Name
+====
+
+cec-ioctl - Control a cec device
+
+Synopsis
+========
+
+.. code-block:: c
+
+ #include <sys/ioctl.h>
+
+``int ioctl(int fd, int request, void *argp)``
+
+Arguments
+=========
+
+``fd``
+ File descriptor returned by :c:func:`open()`.
+
+``request``
+ CEC ioctl request code as defined in the cec.h header file, for
+ example :ref:`CEC_ADAP_G_CAPS <CEC_ADAP_G_CAPS>`.
+
+``argp``
+ Pointer to a request-specific structure.
+
+Description
+===========
+
+The :c:func:`ioctl()` function manipulates cec device parameters. The
+argument ``fd`` must be an open file descriptor.
+
+The ioctl ``request`` code specifies the cec function to be called. It
+has encoded in it whether the argument is an input, output or read/write
+parameter, and the size of the argument ``argp`` in bytes.
+
+Macros and structures definitions specifying cec ioctl requests and
+their parameters are located in the cec.h header file. All cec ioctl
+requests, their respective function and parameters are specified in
+:ref:`cec-user-func`.
+
+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.
+
+Request-specific error codes are listed in the individual requests
+descriptions.
+
+When an ioctl that takes an output or read/write parameter fails, the
+parameter remains unmodified.