18c2ecf20Sopenharmony_ci.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later 28c2ecf20Sopenharmony_ci.. c:namespace:: V4L 38c2ecf20Sopenharmony_ci 48c2ecf20Sopenharmony_ci.. _func-munmap: 58c2ecf20Sopenharmony_ci 68c2ecf20Sopenharmony_ci************* 78c2ecf20Sopenharmony_ciV4L2 munmap() 88c2ecf20Sopenharmony_ci************* 98c2ecf20Sopenharmony_ci 108c2ecf20Sopenharmony_ciName 118c2ecf20Sopenharmony_ci==== 128c2ecf20Sopenharmony_ci 138c2ecf20Sopenharmony_civ4l2-munmap - Unmap device memory 148c2ecf20Sopenharmony_ci 158c2ecf20Sopenharmony_ciSynopsis 168c2ecf20Sopenharmony_ci======== 178c2ecf20Sopenharmony_ci 188c2ecf20Sopenharmony_ci.. code-block:: c 198c2ecf20Sopenharmony_ci 208c2ecf20Sopenharmony_ci #include <unistd.h> 218c2ecf20Sopenharmony_ci #include <sys/mman.h> 228c2ecf20Sopenharmony_ci 238c2ecf20Sopenharmony_ci.. c:function:: int munmap( void *start, size_t length ) 248c2ecf20Sopenharmony_ci 258c2ecf20Sopenharmony_ciArguments 268c2ecf20Sopenharmony_ci========= 278c2ecf20Sopenharmony_ci 288c2ecf20Sopenharmony_ci``start`` 298c2ecf20Sopenharmony_ci Address of the mapped buffer as returned by the 308c2ecf20Sopenharmony_ci :c:func:`mmap()` function. 318c2ecf20Sopenharmony_ci 328c2ecf20Sopenharmony_ci``length`` 338c2ecf20Sopenharmony_ci Length of the mapped buffer. This must be the same value as given to 348c2ecf20Sopenharmony_ci :c:func:`mmap()` and returned by the driver in the struct 358c2ecf20Sopenharmony_ci :c:type:`v4l2_buffer` ``length`` field for the 368c2ecf20Sopenharmony_ci single-planar API and in the struct 378c2ecf20Sopenharmony_ci :c:type:`v4l2_plane` ``length`` field for the 388c2ecf20Sopenharmony_ci multi-planar API. 398c2ecf20Sopenharmony_ci 408c2ecf20Sopenharmony_ciDescription 418c2ecf20Sopenharmony_ci=========== 428c2ecf20Sopenharmony_ci 438c2ecf20Sopenharmony_ciUnmaps a previously with the :c:func:`mmap()` function mapped 448c2ecf20Sopenharmony_cibuffer and frees it, if possible. 458c2ecf20Sopenharmony_ci 468c2ecf20Sopenharmony_ciReturn Value 478c2ecf20Sopenharmony_ci============ 488c2ecf20Sopenharmony_ci 498c2ecf20Sopenharmony_ciOn success :c:func:`munmap()` returns 0, on failure -1 and the 508c2ecf20Sopenharmony_ci``errno`` variable is set appropriately: 518c2ecf20Sopenharmony_ci 528c2ecf20Sopenharmony_ciEINVAL 538c2ecf20Sopenharmony_ci The ``start`` or ``length`` is incorrect, or no buffers have been 548c2ecf20Sopenharmony_ci mapped yet. 55