diff options
Diffstat (limited to 'Documentation/media/uapi/v4l/vidioc-reqbufs.rst')
| -rw-r--r-- | Documentation/media/uapi/v4l/vidioc-reqbufs.rst | 66 |
1 files changed, 23 insertions, 43 deletions
diff --git a/Documentation/media/uapi/v4l/vidioc-reqbufs.rst b/Documentation/media/uapi/v4l/vidioc-reqbufs.rst index 5d0bc6d31c07..a4180d576ee5 100644 --- a/Documentation/media/uapi/v4l/vidioc-reqbufs.rst +++ b/Documentation/media/uapi/v4l/vidioc-reqbufs.rst @@ -15,7 +15,8 @@ VIDIOC_REQBUFS - Initiate Memory Mapping, User Pointer I/O or DMA buffer I/O Synopsis ======== -.. cpp:function:: int ioctl( int fd, int request, struct v4l2_requestbuffers *argp ) +.. c:function:: int ioctl( int fd, VIDIOC_REQBUFS, struct v4l2_requestbuffers *argp ) + :name: VIDIOC_REQBUFS Arguments @@ -24,9 +25,6 @@ Arguments ``fd`` File descriptor returned by :ref:`open() <func-open>`. -``request`` - VIDIOC_REQBUFS - ``argp`` @@ -45,7 +43,7 @@ configures the driver into DMABUF I/O mode without performing any direct allocation. To allocate device buffers applications initialize all fields of the -:ref:`struct v4l2_requestbuffers <v4l2-requestbuffers>` structure. They set the ``type`` +struct :c:type:`v4l2_requestbuffers` structure. They set the ``type`` field to the respective stream or buffer type, the ``count`` field to the desired number of buffers, ``memory`` must be set to the requested I/O method and the ``reserved`` array must be zeroed. When the ioctl is @@ -67,50 +65,32 @@ any DMA in progress, an implicit :ref:`VIDIOC_STREAMOFF <VIDIOC_STREAMON>`. -.. _v4l2-requestbuffers: +.. c:type:: v4l2_requestbuffers + +.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}| .. flat-table:: struct v4l2_requestbuffers :header-rows: 0 :stub-columns: 0 :widths: 1 1 2 - - - .. row 1 - - - __u32 - - - ``count`` - - - The number of buffers requested or granted. - - - .. row 2 - - - __u32 - - - ``type`` - - - Type of the stream or buffers, this is the same as the struct - :ref:`v4l2_format <v4l2-format>` ``type`` field. See - :ref:`v4l2-buf-type` for valid values. - - - .. row 3 - - - __u32 - - - ``memory`` - - - Applications set this field to ``V4L2_MEMORY_MMAP``, - ``V4L2_MEMORY_DMABUF`` or ``V4L2_MEMORY_USERPTR``. See - :ref:`v4l2-memory`. - - - .. row 4 - - - __u32 - - - ``reserved``\ [2] - - - A place holder for future extensions. Drivers and applications - must set the array to zero. + * - __u32 + - ``count`` + - The number of buffers requested or granted. + * - __u32 + - ``type`` + - Type of the stream or buffers, this is the same as the struct + :c:type:`v4l2_format` ``type`` field. See + :c:type:`v4l2_buf_type` for valid values. + * - __u32 + - ``memory`` + - Applications set this field to ``V4L2_MEMORY_MMAP``, + ``V4L2_MEMORY_DMABUF`` or ``V4L2_MEMORY_USERPTR``. See + :c:type:`v4l2_memory`. + * - __u32 + - ``reserved``\ [2] + - A place holder for future extensions. Drivers and applications + must set the array to zero. Return Value |