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