| .. -*- 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. |
