git.librecmc.org Git - oweals/openwrt.git/blob

   1 From ebd995296afa99a5c53f164e595f7a6d41d32a01 Mon Sep 17 00:00:00 2001
   2 From: Hans Verkuil <hansverk@cisco.com>
   3 Date: Thu, 23 Aug 2018 09:56:22 -0400
   4 Subject: [PATCH] media: videodev2.h: add new capabilities for buffer
   5  types
   6
   7 Upstream commit f35f5d72e70e6b91389eb98fcabf43b79f40587f
   8
   9 VIDIOC_REQBUFS and VIDIOC_CREATE_BUFFERS will return capabilities
  10 telling userspace what the given buffer type is capable of.
  11
  12 Signed-off-by: Hans Verkuil <hansverk@cisco.com>
  13 Reviewed-by: Tomasz Figa <tfiga@chromium.org>
  14 Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
  15 Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
  16 ---
  17  .../media/uapi/v4l/vidioc-create-bufs.rst     | 14 ++++++-
  18  .../media/uapi/v4l/vidioc-reqbufs.rst         | 42 ++++++++++++++++++-
  19  include/uapi/linux/videodev2.h                | 13 +++++-
  20  3 files changed, 65 insertions(+), 4 deletions(-)
  21
  22 --- a/Documentation/media/uapi/v4l/vidioc-create-bufs.rst
  23 +++ b/Documentation/media/uapi/v4l/vidioc-create-bufs.rst
  24 @@ -102,7 +102,19 @@ than the number requested.
  25        - ``format``
  26        - Filled in by the application, preserved by the driver.
  27      * - __u32
  28 -      - ``reserved``\ [8]
  29 +      - ``capabilities``
  30 +      - Set by the driver. If 0, then the driver doesn't support
  31 +        capabilities. In that case all you know is that the driver is
  32 +       guaranteed to support ``V4L2_MEMORY_MMAP`` and *might* support
  33 +       other :c:type:`v4l2_memory` types. It will not support any others
  34 +       capabilities. See :ref:`here <v4l2-buf-capabilities>` for a list of the
  35 +       capabilities.
  36 +
  37 +       If you want to just query the capabilities without making any
  38 +       other changes, then set ``count`` to 0, ``memory`` to
  39 +       ``V4L2_MEMORY_MMAP`` and ``format.type`` to the buffer type.
  40 +    * - __u32
  41 +      - ``reserved``\ [7]
  42        - A place holder for future extensions. Drivers and applications
  43         must set the array to zero.
  44
  45 --- a/Documentation/media/uapi/v4l/vidioc-reqbufs.rst
  46 +++ b/Documentation/media/uapi/v4l/vidioc-reqbufs.rst
  47 @@ -88,10 +88,50 @@ any DMA in progress, an implicit
  48         ``V4L2_MEMORY_DMABUF`` or ``V4L2_MEMORY_USERPTR``. See
  49         :c:type:`v4l2_memory`.
  50      * - __u32
  51 -      - ``reserved``\ [2]
  52 +      - ``capabilities``
  53 +      - Set by the driver. If 0, then the driver doesn't support
  54 +        capabilities. In that case all you know is that the driver is
  55 +       guaranteed to support ``V4L2_MEMORY_MMAP`` and *might* support
  56 +       other :c:type:`v4l2_memory` types. It will not support any others
  57 +       capabilities.
  58 +
  59 +       If you want to query the capabilities with a minimum of side-effects,
  60 +       then this can be called with ``count`` set to 0, ``memory`` set to
  61 +       ``V4L2_MEMORY_MMAP`` and ``type`` set to the buffer type. This will
  62 +       free any previously allocated buffers, so this is typically something
  63 +       that will be done at the start of the application.
  64 +    * - __u32
  65 +      - ``reserved``\ [1]
  66        - A place holder for future extensions. Drivers and applications
  67         must set the array to zero.
  68
  69 +.. tabularcolumns:: |p{6.1cm}|p{2.2cm}|p{8.7cm}|
  70 +
  71 +.. _v4l2-buf-capabilities:
  72 +.. _V4L2-BUF-CAP-SUPPORTS-MMAP:
  73 +.. _V4L2-BUF-CAP-SUPPORTS-USERPTR:
  74 +.. _V4L2-BUF-CAP-SUPPORTS-DMABUF:
  75 +.. _V4L2-BUF-CAP-SUPPORTS-REQUESTS:
  76 +
  77 +.. cssclass:: longtable
  78 +
  79 +.. flat-table:: V4L2 Buffer Capabilities Flags
  80 +    :header-rows:  0
  81 +    :stub-columns: 0
  82 +    :widths:       3 1 4
  83 +
  84 +    * - ``V4L2_BUF_CAP_SUPPORTS_MMAP``
  85 +      - 0x00000001
  86 +      - This buffer type supports the ``V4L2_MEMORY_MMAP`` streaming mode.
  87 +    * - ``V4L2_BUF_CAP_SUPPORTS_USERPTR``
  88 +      - 0x00000002
  89 +      - This buffer type supports the ``V4L2_MEMORY_USERPTR`` streaming mode.
  90 +    * - ``V4L2_BUF_CAP_SUPPORTS_DMABUF``
  91 +      - 0x00000004
  92 +      - This buffer type supports the ``V4L2_MEMORY_DMABUF`` streaming mode.
  93 +    * - ``V4L2_BUF_CAP_SUPPORTS_REQUESTS``
  94 +      - 0x00000008
  95 +      - This buffer type supports :ref:`requests <media-request-api>`.
  96
  97  Return Value
  98  ============
  99 --- a/include/uapi/linux/videodev2.h
 100 +++ b/include/uapi/linux/videodev2.h
 101 @@ -872,9 +872,16 @@ struct v4l2_requestbuffers {
 102         __u32                   count;
 103         __u32                   type;           /* enum v4l2_buf_type */
 104         __u32                   memory;         /* enum v4l2_memory */
 105 -       __u32                   reserved[2];
 106 +       __u32                   capabilities;
 107 +       __u32                   reserved[1];
 108  };
 109
 110 +/* capabilities for struct v4l2_requestbuffers and v4l2_create_buffers */
 111 +#define V4L2_BUF_CAP_SUPPORTS_MMAP     (1 << 0)
 112 +#define V4L2_BUF_CAP_SUPPORTS_USERPTR  (1 << 1)
 113 +#define V4L2_BUF_CAP_SUPPORTS_DMABUF   (1 << 2)
 114 +#define V4L2_BUF_CAP_SUPPORTS_REQUESTS (1 << 3)
 115 +
 116  /**
 117   * struct v4l2_plane - plane info for multi-planar buffers
 118   * @bytesused:         number of bytes occupied by data in the plane (payload)
 119 @@ -2318,6 +2325,7 @@ struct v4l2_dbg_chip_info {
 120   *             return: number of created buffers
 121   * @memory:    enum v4l2_memory; buffer memory type
 122   * @format:    frame format, for which buffers are requested
 123 + * @capabilities: capabilities of this buffer type.
 124   * @reserved:  future extensions
 125   */
 126  struct v4l2_create_buffers {
 127 @@ -2325,7 +2333,8 @@ struct v4l2_create_buffers {
 128         __u32                   count;
 129         __u32                   memory;
 130         struct v4l2_format      format;
 131 -       __u32                   reserved[8];
 132 +       __u32                   capabilities;
 133 +       __u32                   reserved[7];
 134  };
 135
 136  /*