2
0
mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-27 22:53:55 +08:00
linux-next/Documentation/media/uapi/v4l/func-munmap.rst
Mauro Carvalho Chehab e8be7e97e6 [media] docs-rst: convert uAPI structs to C domain
instead of declaring the uAPI structs using usual refs, e. g.:
	.. _foo-struct:

Use the C domain way:
	.. c:type:: foo_struct

This way, the kAPI documentation can use cross-references to
point to the uAPI symbols.

That solves about ~100 undefined warnings like:
	WARNING: c:type reference target not found: foo_struct

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-09-09 09:34:01 -03:00

59 lines
1.1 KiB
ReStructuredText

.. -*- coding: utf-8; mode: rst -*-
.. _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 )
:name: v4l2-munmap
Arguments
=========
``start``
Address of the mapped buffer as returned by the
:ref:`mmap() <func-mmap>` function.
``length``
Length of the mapped buffer. This must be the same value as given to
:ref:`mmap() <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 :ref:`mmap() <func-mmap>` function mapped
buffer and frees it, if possible.
Return Value
============
On success :ref:`munmap() <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.