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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /Documentation/userspace-api/media/mediactl/media-func-ioctl.rst | |
parent | Initial commit. (diff) | |
download | linux-upstream/5.10.209.tar.xz linux-upstream/5.10.209.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | Documentation/userspace-api/media/mediactl/media-func-ioctl.rst | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/Documentation/userspace-api/media/mediactl/media-func-ioctl.rst b/Documentation/userspace-api/media/mediactl/media-func-ioctl.rst new file mode 100644 index 000000000..9e9a838f4 --- /dev/null +++ b/Documentation/userspace-api/media/mediactl/media-func-ioctl.rst @@ -0,0 +1,63 @@ +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later +.. c:namespace:: MC + +.. _media-func-ioctl: + +************* +media ioctl() +************* + +Name +==== + +media-ioctl - Control a media 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`` + Media ioctl request code as defined in the media.h header file, for + example MEDIA_IOC_SETUP_LINK. + +``argp`` + Pointer to a request-specific structure. + +Description +=========== + +The :ref:`ioctl() <media-func-ioctl>` function manipulates media device +parameters. The argument ``fd`` must be an open file descriptor. + +The ioctl ``request`` code specifies the media 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 media ioctl requests and +their parameters are located in the media.h header file. All media ioctl +requests, their respective function and parameters are specified in +:ref:`media-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. |