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author | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2016-10-20 00:10:27 -0300 |
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committer | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2016-10-20 00:10:27 -0300 |
commit | d0b2f91bede3bd5e3d24dd6803e56eee959c1797 (patch) | |
tree | 7fee4ab0509879c373c4f2cbd5b8a5be5b4041ee /Documentation/media/uapi/cec/cec-func-ioctl.rst | |
parent | e914f8eb445e8f74b00303c19c2ffceaedd16a05 (diff) |
Linux-libre 4.8.2-gnupck-4.8.2-gnu
Diffstat (limited to 'Documentation/media/uapi/cec/cec-func-ioctl.rst')
-rw-r--r-- | Documentation/media/uapi/cec/cec-func-ioctl.rst | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/Documentation/media/uapi/cec/cec-func-ioctl.rst b/Documentation/media/uapi/cec/cec-func-ioctl.rst new file mode 100644 index 000000000..d0279e6d2 --- /dev/null +++ b/Documentation/media/uapi/cec/cec-func-ioctl.rst @@ -0,0 +1,68 @@ +.. -*- coding: utf-8; mode: rst -*- + +.. _cec-func-ioctl: + +*********** +cec ioctl() +*********** + +Name +==== + +cec-ioctl - Control a cec device + +Synopsis +======== + +.. code-block:: c + + #include <sys/ioctl.h> + + +.. cpp:function:: int ioctl( int fd, int request, void *argp ) + +Arguments +========= + +``fd`` + File descriptor returned by :ref:`open() <func-open>`. + +``request`` + CEC ioctl request code as defined in the cec.h header file, for + example :ref:`CEC_ADAP_G_CAPS`. + +``argp`` + Pointer to a request-specific structure. + + +Description +=========== + +.. note:: This documents the proposed CEC API. This API is not yet finalized + and is currently only available as a staging kernel module. + +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. |