162306a36Sopenharmony_ci.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later 262306a36Sopenharmony_ci.. c:namespace:: V4L 362306a36Sopenharmony_ci 462306a36Sopenharmony_ci.. _func-munmap: 562306a36Sopenharmony_ci 662306a36Sopenharmony_ci************* 762306a36Sopenharmony_ciV4L2 munmap() 862306a36Sopenharmony_ci************* 962306a36Sopenharmony_ci 1062306a36Sopenharmony_ciName 1162306a36Sopenharmony_ci==== 1262306a36Sopenharmony_ci 1362306a36Sopenharmony_civ4l2-munmap - Unmap device memory 1462306a36Sopenharmony_ci 1562306a36Sopenharmony_ciSynopsis 1662306a36Sopenharmony_ci======== 1762306a36Sopenharmony_ci 1862306a36Sopenharmony_ci.. code-block:: c 1962306a36Sopenharmony_ci 2062306a36Sopenharmony_ci #include <unistd.h> 2162306a36Sopenharmony_ci #include <sys/mman.h> 2262306a36Sopenharmony_ci 2362306a36Sopenharmony_ci.. c:function:: int munmap( void *start, size_t length ) 2462306a36Sopenharmony_ci 2562306a36Sopenharmony_ciArguments 2662306a36Sopenharmony_ci========= 2762306a36Sopenharmony_ci 2862306a36Sopenharmony_ci``start`` 2962306a36Sopenharmony_ci Address of the mapped buffer as returned by the 3062306a36Sopenharmony_ci :c:func:`mmap()` function. 3162306a36Sopenharmony_ci 3262306a36Sopenharmony_ci``length`` 3362306a36Sopenharmony_ci Length of the mapped buffer. This must be the same value as given to 3462306a36Sopenharmony_ci :c:func:`mmap()` and returned by the driver in the struct 3562306a36Sopenharmony_ci :c:type:`v4l2_buffer` ``length`` field for the 3662306a36Sopenharmony_ci single-planar API and in the struct 3762306a36Sopenharmony_ci :c:type:`v4l2_plane` ``length`` field for the 3862306a36Sopenharmony_ci multi-planar API. 3962306a36Sopenharmony_ci 4062306a36Sopenharmony_ciDescription 4162306a36Sopenharmony_ci=========== 4262306a36Sopenharmony_ci 4362306a36Sopenharmony_ciUnmaps a previously with the :c:func:`mmap()` function mapped 4462306a36Sopenharmony_cibuffer and frees it, if possible. 4562306a36Sopenharmony_ci 4662306a36Sopenharmony_ciReturn Value 4762306a36Sopenharmony_ci============ 4862306a36Sopenharmony_ci 4962306a36Sopenharmony_ciOn success :c:func:`munmap()` returns 0, on failure -1 and the 5062306a36Sopenharmony_ci``errno`` variable is set appropriately: 5162306a36Sopenharmony_ci 5262306a36Sopenharmony_ciEINVAL 5362306a36Sopenharmony_ci The ``start`` or ``length`` is incorrect, or no buffers have been 5462306a36Sopenharmony_ci mapped yet. 55