diff options
Diffstat (limited to 'Documentation/userspace-api/media/dvb/dmx-mmap.rst')
| -rw-r--r-- | Documentation/userspace-api/media/dvb/dmx-mmap.rst | 15 |
1 files changed, 6 insertions, 9 deletions
diff --git a/Documentation/userspace-api/media/dvb/dmx-mmap.rst b/Documentation/userspace-api/media/dvb/dmx-mmap.rst index efa9b04be700..8826c6226fb0 100644 --- a/Documentation/userspace-api/media/dvb/dmx-mmap.rst +++ b/Documentation/userspace-api/media/dvb/dmx-mmap.rst @@ -1,4 +1,5 @@ .. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later +.. c:namespace:: DTV.dmx .. _dmx-mmap: @@ -21,9 +22,7 @@ Synopsis #include <unistd.h> #include <sys/mman.h> - .. c:function:: void *mmap( void *start, size_t length, int prot, int flags, int fd, off_t offset ) - :name: dmx-mmap Arguments ========= @@ -54,7 +53,7 @@ Arguments ``MAP_FIXED`` requests that the driver selects no other address than the one specified. If the specified address cannot be used, - :ref:`mmap() <dmx-mmap>` will fail. If ``MAP_FIXED`` is specified, + :c:func:`mmap()` will fail. If ``MAP_FIXED`` is specified, ``start`` must be a multiple of the pagesize. Use of this option is discouraged. @@ -69,17 +68,16 @@ Arguments flags. ``fd`` - File descriptor returned by :ref:`open() <dmx_fopen>`. + File descriptor returned by :c:func:`open()`. ``offset`` Offset of the buffer in device memory, as returned by :ref:`DMX_QUERYBUF` ioctl. - Description =========== -The :ref:`mmap() <dmx-mmap>` function asks to map ``length`` bytes starting at +The :c:func:`mmap()` function asks to map ``length`` bytes starting at ``offset`` in the memory of the device specified by ``fd`` into the application address space, preferably at address ``start``. This latter address is a hint only, and is usually specified as 0. @@ -88,13 +86,12 @@ Suitable length and offset parameters are queried with the :ref:`DMX_QUERYBUF` ioctl. Buffers must be allocated with the :ref:`DMX_REQBUFS` ioctl before they can be queried. -To unmap buffers the :ref:`munmap() <dmx-munmap>` function is used. - +To unmap buffers the :c:func:`munmap()` function is used. Return Value ============ -On success :ref:`mmap() <dmx-mmap>` returns a pointer to the mapped buffer. On +On success :c:func:`mmap()` returns a pointer to the mapped buffer. On error ``MAP_FAILED`` (-1) is returned, and the ``errno`` variable is set appropriately. Possible error codes are: |