blob: 116132b19515fdb803ab36e1edba5b8ed8413967 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
|
.. -*- 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 )
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.
|
