[deliverable/linux.git] / Documentation / media / uapi / cec / cec-func-ioctl.rst

.. -*- 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>


.. c:function:: int ioctl( int fd, int request, void *argp )
   :name: cec-ioctl

Arguments
=========

``fd``
    File descriptor returned by :c:func:`open() <cec-open>`.

``request``
    CEC ioctl request code as defined in the cec.h header file, for
    example :c:func:`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.
Commit	Line	Data
e2460b1d MH	1	.. -- coding: utf-8; mode: rst --
	2
	3	.. _cec-func-ioctl:
	4
	5	***********
	6	cec ioctl()
	7	***********
	8
21c62694 MH	9	Name
21c62694 MH	10	====
e2460b1d	11
21c62694	12	cec-ioctl - Control a cec device
e2460b1d MH	13
	14	Synopsis
	15	========
	16
	17	.. code-block:: c
	18
	19	#include <sys/ioctl.h>
	20
	21
1b81f010	22	.. c:function:: int ioctl( int fd, int request, void *argp )
99547836	23	:name: cec-ioctl
e2460b1d MH	24
	25	Arguments
	26	=========
	27
	28	``fd``
99547836	29	File descriptor returned by :c:func:`open() <cec-open>`.
e2460b1d MH	30
	31	``request``
	32	CEC ioctl request code as defined in the cec.h header file, for
99547836	33	example :c:func:`CEC_ADAP_G_CAPS`.
e2460b1d MH	34
	35	``argp``
	36	Pointer to a request-specific structure.
	37
	38
	39	Description
	40	===========
	41
b6b6e678 MCC	42	.. note::
	43
	44	This documents the proposed CEC API. This API is not yet finalized
706f8a99	45	and is currently only available as a staging kernel module.
e2460b1d MH	46
	47	The :c:func:`ioctl()` function manipulates cec device parameters. The
	48	argument ``fd`` must be an open file descriptor.
	49
	50	The ioctl ``request`` code specifies the cec function to be called. It
	51	has encoded in it whether the argument is an input, output or read/write
	52	parameter, and the size of the argument ``argp`` in bytes.
	53
	54	Macros and structures definitions specifying cec ioctl requests and
	55	their parameters are located in the cec.h header file. All cec ioctl
	56	requests, their respective function and parameters are specified in
	57	:ref:`cec-user-func`.
	58
	59
	60	Return Value
	61	============
	62
	63	On success 0 is returned, on error -1 and the ``errno`` variable is set
	64	appropriately. The generic error codes are described at the
	65	:ref:`Generic Error Codes <gen-errors>` chapter.
	66
	67	Request-specific error codes are listed in the individual requests
	68	descriptions.
	69
	70	When an ioctl that takes an output or read/write parameter fails, the
	71	parameter remains unmodified.