1 .. SPDX-License-Identifier: GFDL-1.1-no-invari !! 1 .. Permission is granted to copy, distribute and/or modify this
2 .. c:namespace:: V4L !! 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 .. _func-munmap: 10 .. _func-munmap:
5 11
6 ************* 12 *************
7 V4L2 munmap() 13 V4L2 munmap()
8 ************* 14 *************
9 15
10 Name 16 Name
11 ==== 17 ====
12 18
13 v4l2-munmap - Unmap device memory 19 v4l2-munmap - Unmap device memory
14 20
>> 21
15 Synopsis 22 Synopsis
16 ======== 23 ========
17 24
18 .. code-block:: c 25 .. code-block:: c
19 26
20 #include <unistd.h> 27 #include <unistd.h>
21 #include <sys/mman.h> 28 #include <sys/mman.h>
22 29
>> 30
23 .. c:function:: int munmap( void *start, size_ 31 .. c:function:: int munmap( void *start, size_t length )
>> 32 :name: v4l2-munmap
24 33
25 Arguments 34 Arguments
26 ========= 35 =========
27 36
28 ``start`` 37 ``start``
29 Address of the mapped buffer as returned b 38 Address of the mapped buffer as returned by the
30 :c:func:`mmap()` function. !! 39 :ref:`mmap() <func-mmap>` function.
31 40
32 ``length`` 41 ``length``
33 Length of the mapped buffer. This must be 42 Length of the mapped buffer. This must be the same value as given to
34 :c:func:`mmap()` and returned by the drive !! 43 :ref:`mmap() <func-mmap>` and returned by the driver in the struct
35 :c:type:`v4l2_buffer` ``length`` field for 44 :c:type:`v4l2_buffer` ``length`` field for the
36 single-planar API and in the struct 45 single-planar API and in the struct
37 :c:type:`v4l2_plane` ``length`` field for 46 :c:type:`v4l2_plane` ``length`` field for the
38 multi-planar API. 47 multi-planar API.
39 48
>> 49
40 Description 50 Description
41 =========== 51 ===========
42 52
43 Unmaps a previously with the :c:func:`mmap()` !! 53 Unmaps a previously with the :ref:`mmap() <func-mmap>` function mapped
44 buffer and frees it, if possible. 54 buffer and frees it, if possible.
45 55
>> 56
46 Return Value 57 Return Value
47 ============ 58 ============
48 59
49 On success :c:func:`munmap()` returns 0, on fa !! 60 On success :ref:`munmap() <func-munmap>` returns 0, on failure -1 and the
50 ``errno`` variable is set appropriately: 61 ``errno`` variable is set appropriately:
51 62
52 EINVAL 63 EINVAL
53 The ``start`` or ``length`` is incorrect, 64 The ``start`` or ``length`` is incorrect, or no buffers have been
54 mapped yet. 65 mapped yet.
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