X-Git-Url: http://git.cascardo.info/?p=cascardo%2Flinux.git;a=blobdiff_plain;f=Documentation%2Fmedia%2Fuapi%2Fv4l%2Fvidioc-create-bufs.rst;h=aaca12fca06e8b51a8161f9d2c4767c809a8cbd3;hp=dc75f21e4b4c6e0025a80d3df2526ab5b711e950;hb=8a1e377e55f2dca5c689926313beeaa8ac2adb22;hpb=5049d31bc34d64b255b0470cace7d0221f0d6b0f diff --git a/Documentation/media/uapi/v4l/vidioc-create-bufs.rst b/Documentation/media/uapi/v4l/vidioc-create-bufs.rst index dc75f21e4b4c..aaca12fca06e 100644 --- a/Documentation/media/uapi/v4l/vidioc-create-bufs.rst +++ b/Documentation/media/uapi/v4l/vidioc-create-bufs.rst @@ -39,14 +39,14 @@ over buffers is required. This ioctl can be called multiple times to create buffers of different sizes. To allocate the device buffers applications must initialize the relevant -fields of the :ref:`struct v4l2_create_buffers ` structure. The +fields of the struct :c:type:`v4l2_create_buffers` structure. The ``count`` field must be set to the number of requested buffers, the ``memory`` field specifies the requested I/O method and the ``reserved`` array must be zeroed. The ``format`` field specifies the image format that the buffers must be able to handle. The application has to fill in this struct -:ref:`v4l2_format `. Usually this will be done using the +:c:type:`v4l2_format`. Usually this will be done using the :ref:`VIDIOC_TRY_FMT ` or :ref:`VIDIOC_G_FMT ` ioctls to ensure that the requested format is supported by the driver. Based on the format's @@ -71,7 +71,7 @@ the ``index`` fields respectively. On return ``count`` can be smaller than the number requested. -.. _v4l2-create-buffers: +.. c:type:: v4l2_create_buffers .. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}| @@ -80,55 +80,30 @@ than the number requested. :stub-columns: 0 :widths: 1 1 2 - - - .. row 1 - - - __u32 - - - ``index`` - - - The starting buffer index, returned by the driver. - - - .. row 2 - - - __u32 - - - ``count`` - - - The number of buffers requested or granted. If count == 0, then - :ref:`VIDIOC_CREATE_BUFS` will set ``index`` to the current number of - created buffers, and it will check the validity of ``memory`` and - ``format.type``. If those are invalid -1 is returned and errno is - set to ``EINVAL`` error code, otherwise :ref:`VIDIOC_CREATE_BUFS` returns - 0. It will never set errno to ``EBUSY`` error code in this particular - case. - - - .. 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 - - - struct :ref:`v4l2_format ` - - - ``format`` - - - Filled in by the application, preserved by the driver. - - - .. row 5 - - - __u32 - - - ``reserved``\ [8] - - - A place holder for future extensions. Drivers and applications - must set the array to zero. + * - __u32 + - ``index`` + - The starting buffer index, returned by the driver. + * - __u32 + - ``count`` + - The number of buffers requested or granted. If count == 0, then + :ref:`VIDIOC_CREATE_BUFS` will set ``index`` to the current number of + created buffers, and it will check the validity of ``memory`` and + ``format.type``. If those are invalid -1 is returned and errno is + set to ``EINVAL`` error code, otherwise :ref:`VIDIOC_CREATE_BUFS` returns + 0. It will never set errno to ``EBUSY`` error code in this particular + case. + * - __u32 + - ``memory`` + - Applications set this field to ``V4L2_MEMORY_MMAP``, + ``V4L2_MEMORY_DMABUF`` or ``V4L2_MEMORY_USERPTR``. See + :c:type:`v4l2_memory` + * - struct :c:type:`v4l2_format` + - ``format`` + - Filled in by the application, preserved by the driver. + * - __u32 + - ``reserved``\ [8] + - A place holder for future extensions. Drivers and applications + must set the array to zero. Return Value