diff options
Diffstat (limited to 'Documentation/userspace-api/media/v4l/buffer.rst')
| -rw-r--r-- | Documentation/userspace-api/media/v4l/buffer.rst | 54 |
1 files changed, 4 insertions, 50 deletions
diff --git a/Documentation/userspace-api/media/v4l/buffer.rst b/Documentation/userspace-api/media/v4l/buffer.rst index 57e752aaf414..7dbdfbb4a0a9 100644 --- a/Documentation/userspace-api/media/v4l/buffer.rst +++ b/Documentation/userspace-api/media/v4l/buffer.rst @@ -1,11 +1,5 @@ -.. 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/userspace-api/media/fdl-appendix.rst. -.. -.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later +.. c:namespace:: V4L .. _buffer: @@ -40,7 +34,6 @@ mem-to-mem devices is an exception to the rule: the timestamp source flags are copied from the OUTPUT video buffer to the CAPTURE video buffer. - Interactions between formats, controls and buffers ================================================== @@ -159,7 +152,6 @@ based on the queried sizes (for instance by allocating a set of buffers large enough for all the desired formats and controls, or by allocating separate set of appropriately sized buffers for each use case). - .. c:type:: v4l2_buffer struct v4l2_buffer @@ -264,7 +256,7 @@ struct v4l2_buffer ``V4L2_MEMORY_MMAP`` this is the offset of the buffer from the start of the device memory. The value is returned by the driver and apart of serving as parameter to the - :ref:`mmap() <func-mmap>` function not useful for applications. + :c:func:`mmap()` function not useful for applications. See :ref:`mmap` for details * - unsigned long - ``userptr`` @@ -317,7 +309,6 @@ struct v4l2_buffer given, then ``EINVAL`` will be returned. - .. c:type:: v4l2_plane struct v4l2_plane @@ -357,7 +348,7 @@ struct v4l2_plane - ``mem_offset`` - When the memory type in the containing struct :c:type:`v4l2_buffer` is ``V4L2_MEMORY_MMAP``, this - is the value that should be passed to :ref:`mmap() <func-mmap>`, + is the value that should be passed to :c:func:`mmap()`, similar to the ``offset`` field in struct :c:type:`v4l2_buffer`. * - unsigned long @@ -391,7 +382,6 @@ struct v4l2_plane applications. - .. c:type:: v4l2_buf_type enum v4l2_buf_type @@ -455,7 +445,6 @@ enum v4l2_buf_type - Buffer for metadata output, see :ref:`metadata`. - .. _buffer-flags: Buffer Flags @@ -689,37 +678,6 @@ Buffer Flags .. _memory-flags: -Memory Consistency Flags -======================== - -.. tabularcolumns:: |p{7.0cm}|p{2.2cm}|p{8.3cm}| - -.. cssclass:: longtable - -.. flat-table:: - :header-rows: 0 - :stub-columns: 0 - :widths: 3 1 4 - - * .. _`V4L2-FLAG-MEMORY-NON-CONSISTENT`: - - - ``V4L2_FLAG_MEMORY_NON_CONSISTENT`` - - 0x00000001 - - A buffer is allocated either in consistent (it will be automatically - coherent between the CPU and the bus) or non-consistent memory. The - latter can provide performance gains, for instance the CPU cache - sync/flush operations can be avoided if the buffer is accessed by the - corresponding device only and the CPU does not read/write to/from that - buffer. However, this requires extra care from the driver -- it must - guarantee memory consistency by issuing a cache flush/sync when - consistency is needed. If this flag is set V4L2 will attempt to - allocate the buffer in non-consistent memory. The flag takes effect - only if the buffer is used for :ref:`memory mapping <mmap>` I/O and the - queue reports the :ref:`V4L2_BUF_CAP_SUPPORTS_MMAP_CACHE_HINTS - <V4L2-BUF-CAP-SUPPORTS-MMAP-CACHE-HINTS>` capability. - -.. c:type:: v4l2_memory - enum v4l2_memory ================ @@ -744,7 +702,6 @@ enum v4l2_memory - The buffer is used for :ref:`DMA shared buffer <dmabuf>` I/O. - Timecodes ========= @@ -753,7 +710,6 @@ The :c:type:`v4l2_buffer_timecode` structure is designed to hold a (struct :c:type:`timeval` timestamps are stored in the struct :c:type:`v4l2_buffer` ``timestamp`` field.) - .. c:type:: v4l2_timecode struct v4l2_timecode @@ -790,7 +746,6 @@ struct v4l2_timecode - The "user group" bits from the timecode. - .. _timecode-type: Timecode Types @@ -820,7 +775,6 @@ Timecode Types - - .. _timecode-flags: Timecode Flags |