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diff --git a/Documentation/media/uapi/v4l/vidioc-expbuf.rst b/Documentation/media/uapi/v4l/vidioc-expbuf.rst deleted file mode 100644 index 4bd8cd79754c..000000000000 --- a/Documentation/media/uapi/v4l/vidioc-expbuf.rst +++ /dev/null @@ -1,175 +0,0 @@ -.. Permission is granted to copy, distribute and/or modify this -.. document under the terms of the GNU Free Documentation License, -.. Version 1.1 or any later version published by the Free Software -.. Foundation, with no Invariant Sections, no Front-Cover Texts -.. and no Back-Cover Texts. A copy of the license is included at -.. Documentation/media/uapi/fdl-appendix.rst. -.. -.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections - -.. _VIDIOC_EXPBUF: - -******************* -ioctl VIDIOC_EXPBUF -******************* - -Name -==== - -VIDIOC_EXPBUF - Export a buffer as a DMABUF file descriptor. - - -Synopsis -======== - -.. c:function:: int ioctl( int fd, VIDIOC_EXPBUF, struct v4l2_exportbuffer *argp ) - :name: VIDIOC_EXPBUF - - -Arguments -========= - -``fd`` - File descriptor returned by :ref:`open() <func-open>`. - -``argp`` - Pointer to struct :c:type:`v4l2_exportbuffer`. - - -Description -=========== - -This ioctl is an extension to the :ref:`memory mapping <mmap>` I/O -method, therefore it is available only for ``V4L2_MEMORY_MMAP`` buffers. -It can be used to export a buffer as a DMABUF file at any time after -buffers have been allocated with the -:ref:`VIDIOC_REQBUFS` ioctl. - -To export a buffer, applications fill struct -:c:type:`v4l2_exportbuffer`. The ``type`` field is -set to the same buffer type as was previously used with struct -:c:type:`v4l2_requestbuffers` ``type``. -Applications must also set the ``index`` field. Valid index numbers -range from zero to the number of buffers allocated with -:ref:`VIDIOC_REQBUFS` (struct -:c:type:`v4l2_requestbuffers` ``count``) minus -one. For the multi-planar API, applications set the ``plane`` field to -the index of the plane to be exported. Valid planes range from zero to -the maximal number of valid planes for the currently active format. For -the single-planar API, applications must set ``plane`` to zero. -Additional flags may be posted in the ``flags`` field. Refer to a manual -for open() for details. Currently only O_CLOEXEC, O_RDONLY, O_WRONLY, -and O_RDWR are supported. All other fields must be set to zero. In the -case of multi-planar API, every plane is exported separately using -multiple :ref:`VIDIOC_EXPBUF` calls. - -After calling :ref:`VIDIOC_EXPBUF` the ``fd`` field will be set by a -driver. This is a DMABUF file descriptor. The application may pass it to -other DMABUF-aware devices. Refer to :ref:`DMABUF importing <dmabuf>` -for details about importing DMABUF files into V4L2 nodes. It is -recommended to close a DMABUF file when it is no longer used to allow -the associated memory to be reclaimed. - - -Examples -======== - - -.. code-block:: c - - int buffer_export(int v4lfd, enum v4l2_buf_type bt, int index, int *dmafd) - { - struct v4l2_exportbuffer expbuf; - - memset(&expbuf, 0, sizeof(expbuf)); - expbuf.type = bt; - expbuf.index = index; - if (ioctl(v4lfd, VIDIOC_EXPBUF, &expbuf) == -1) { - perror("VIDIOC_EXPBUF"); - return -1; - } - - *dmafd = expbuf.fd; - - return 0; - } - - -.. code-block:: c - - int buffer_export_mp(int v4lfd, enum v4l2_buf_type bt, int index, - int dmafd[], int n_planes) - { - int i; - - for (i = 0; i < n_planes; ++i) { - struct v4l2_exportbuffer expbuf; - - memset(&expbuf, 0, sizeof(expbuf)); - expbuf.type = bt; - expbuf.index = index; - expbuf.plane = i; - if (ioctl(v4lfd, VIDIOC_EXPBUF, &expbuf) == -1) { - perror("VIDIOC_EXPBUF"); - while (i) - close(dmafd[--i]); - return -1; - } - dmafd[i] = expbuf.fd; - } - - return 0; - } - - -.. c:type:: v4l2_exportbuffer - -.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}| - -.. flat-table:: struct v4l2_exportbuffer - :header-rows: 0 - :stub-columns: 0 - :widths: 1 1 2 - - * - __u32 - - ``type`` - - Type of the buffer, same as struct - :c:type:`v4l2_format` ``type`` or struct - :c:type:`v4l2_requestbuffers` ``type``, set - by the application. See :c:type:`v4l2_buf_type` - * - __u32 - - ``index`` - - Number of the buffer, set by the application. This field is only - used for :ref:`memory mapping <mmap>` I/O and can range from - zero to the number of buffers allocated with the - :ref:`VIDIOC_REQBUFS` and/or - :ref:`VIDIOC_CREATE_BUFS` ioctls. - * - __u32 - - ``plane`` - - Index of the plane to be exported when using the multi-planar API. - Otherwise this value must be set to zero. - * - __u32 - - ``flags`` - - Flags for the newly created file, currently only ``O_CLOEXEC``, - ``O_RDONLY``, ``O_WRONLY``, and ``O_RDWR`` are supported, refer to - the manual of open() for more details. - * - __s32 - - ``fd`` - - The DMABUF file descriptor associated with a buffer. Set by the - driver. - * - __u32 - - ``reserved[11]`` - - Reserved field for future use. Drivers and applications must set - the array to zero. - - -Return Value -============ - -On success 0 is returned, on error -1 and the ``errno`` variable is set -appropriately. The generic error codes are described at the -:ref:`Generic Error Codes <gen-errors>` chapter. - -EINVAL - A queue is not in MMAP mode or DMABUF exporting is not supported or - ``flags`` or ``type`` or ``index`` or ``plane`` fields are invalid. |