blob: 077d58333904b98ab3ec4862e48e6a1864af8f56 (
plain) (
blame)
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
|
.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
.. c:namespace:: V4L
.. _func-munmap:
*************
V4L2 munmap()
*************
Name
====
v4l2-munmap - Unmap device memory
Synopsis
========
.. code-block:: c
#include <unistd.h>
#include <sys/mman.h>
.. c:function:: int munmap( void *start, size_t length )
Arguments
=========
``start``
Address of the mapped buffer as returned by the
:c:func:`mmap()` function.
``length``
Length of the mapped buffer. This must be the same value as given to
:c:func:`mmap()` and returned by the driver in the struct
:c:type:`v4l2_buffer` ``length`` field for the
single-planar API and in the struct
:c:type:`v4l2_plane` ``length`` field for the
multi-planar API.
Description
===========
Unmaps a previously with the :c:func:`mmap()` function mapped
buffer and frees it, if possible.
Return Value
============
On success :c:func:`munmap()` returns 0, on failure -1 and the
``errno`` variable is set appropriately:
EINVAL
The ``start`` or ``length`` is incorrect, or no buffers have been
mapped yet.
|
