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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /Documentation/userspace-api/media/v4l/func-munmap.rst | |
parent | Initial commit. (diff) | |
download | linux-upstream/5.10.209.tar.xz linux-upstream/5.10.209.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'Documentation/userspace-api/media/v4l/func-munmap.rst')
-rw-r--r-- | Documentation/userspace-api/media/v4l/func-munmap.rst | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/Documentation/userspace-api/media/v4l/func-munmap.rst b/Documentation/userspace-api/media/v4l/func-munmap.rst new file mode 100644 index 000000000..077d58333 --- /dev/null +++ b/Documentation/userspace-api/media/v4l/func-munmap.rst @@ -0,0 +1,54 @@ +.. 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. |