1 .. SPDX-License-Identifier: GFDL-1.1-no-invari !! 1 .. Permission is granted to copy, distribute and/or modify this
2 .. c:namespace:: MC !! 2 .. document under the terms of the GNU Free Documentation License,
>> 3 .. Version 1.1 or any later version published by the Free Software
>> 4 .. Foundation, with no Invariant Sections, no Front-Cover Texts
>> 5 .. and no Back-Cover Texts. A copy of the license is included at
>> 6 .. Documentation/userspace-api/media/fdl-appendix.rst.
>> 7 ..
>> 8 .. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections
3 9
4 .. _media-func-ioctl: 10 .. _media-func-ioctl:
5 11
6 ************* 12 *************
7 media ioctl() 13 media ioctl()
8 ************* 14 *************
9 15
10 Name 16 Name
11 ==== 17 ====
12 18
13 media-ioctl - Control a media device 19 media-ioctl - Control a media device
14 20
>> 21
15 Synopsis 22 Synopsis
16 ======== 23 ========
17 24
18 .. code-block:: c 25 .. code-block:: c
19 26
20 #include <sys/ioctl.h> 27 #include <sys/ioctl.h>
21 28
22 ``int ioctl(int fd, int request, void *argp)`` !! 29
>> 30 .. c:function:: int ioctl( int fd, int request, void *argp )
>> 31 :name: mc-ioctl
23 32
24 Arguments 33 Arguments
25 ========= 34 =========
26 35
27 ``fd`` 36 ``fd``
28 File descriptor returned by :c:func:`open( !! 37 File descriptor returned by :c:func:`open() <mc-open>`.
29 38
30 ``request`` 39 ``request``
31 Media ioctl request code as defined in the 40 Media ioctl request code as defined in the media.h header file, for
32 example MEDIA_IOC_SETUP_LINK. 41 example MEDIA_IOC_SETUP_LINK.
33 42
34 ``argp`` 43 ``argp``
35 Pointer to a request-specific structure. 44 Pointer to a request-specific structure.
36 45
>> 46
37 Description 47 Description
38 =========== 48 ===========
39 49
40 The :ref:`ioctl() <media-func-ioctl>` function 50 The :ref:`ioctl() <media-func-ioctl>` function manipulates media device
41 parameters. The argument ``fd`` must be an ope 51 parameters. The argument ``fd`` must be an open file descriptor.
42 52
43 The ioctl ``request`` code specifies the media 53 The ioctl ``request`` code specifies the media function to be called. It
44 has encoded in it whether the argument is an i 54 has encoded in it whether the argument is an input, output or read/write
45 parameter, and the size of the argument ``argp 55 parameter, and the size of the argument ``argp`` in bytes.
46 56
47 Macros and structures definitions specifying m 57 Macros and structures definitions specifying media ioctl requests and
48 their parameters are located in the media.h he 58 their parameters are located in the media.h header file. All media ioctl
49 requests, their respective function and parame 59 requests, their respective function and parameters are specified in
50 :ref:`media-user-func`. 60 :ref:`media-user-func`.
>> 61
51 62
52 Return Value 63 Return Value
53 ============ 64 ============
54 65
55 On success 0 is returned, on error -1 and the 66 On success 0 is returned, on error -1 and the ``errno`` variable is set
56 appropriately. The generic error codes are des 67 appropriately. The generic error codes are described at the
57 :ref:`Generic Error Codes <gen-errors>` chapte 68 :ref:`Generic Error Codes <gen-errors>` chapter.
58 69
59 Request-specific error codes are listed in the 70 Request-specific error codes are listed in the individual requests
60 descriptions. 71 descriptions.
61 72
62 When an ioctl that takes an output or read/wri 73 When an ioctl that takes an output or read/write parameter fails, the
63 parameter remains unmodified. 74 parameter remains unmodified.
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