On 26/08/17 13:53, Mauro Carvalho Chehab wrote:
> As both vdev-centric and MC-centric devices may implement the
> same APIs, we need a flag to allow userspace to distinguish
> between them.
>
> Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxxx>
> ---
> Documentation/media/uapi/v4l/open.rst | 7 +++++++
> Documentation/media/uapi/v4l/vidioc-querycap.rst | 5 +++++
> Documentation/media/videodev2.h.rst.exceptions | 1 +
> include/uapi/linux/videodev2.h | 2 ++
> 4 files changed, 15 insertions(+)
>
> diff --git a/Documentation/media/uapi/v4l/open.rst b/Documentation/media/uapi/v4l/open.rst
> index 64b1de047b1b..d0930fc170f0 100644
> --- a/Documentation/media/uapi/v4l/open.rst
> +++ b/Documentation/media/uapi/v4l/open.rst
> @@ -46,6 +46,13 @@ the periferal can be used. For such devices, the sub-devices' configuration
> can be controlled via the :ref:`sub-device API <subdev>`, which creates one
> device node per sub-device.
>
> +.. attention::
> +
> + Devices that require **mc-centric** hardware peripheral control should
MC-centric
As mentioned in my review of a previous patch I dislike the term "peripheral".
I think it should be dropped here.
> + report a ``V4L2_MC_CENTRIC`` :c:type:`v4l2_capability` flag
> + (see :ref:`VIDIOC_QUERYCAP`).
> +
> +
> In summary, for **MC-centric** hardware peripheral control:
>
> - The **V4L2 device** node is responsible for controlling the streaming
> diff --git a/Documentation/media/uapi/v4l/vidioc-querycap.rst b/Documentation/media/uapi/v4l/vidioc-querycap.rst
> index 12e0d9a63cd8..2b08723375bc 100644
> --- a/Documentation/media/uapi/v4l/vidioc-querycap.rst
> +++ b/Documentation/media/uapi/v4l/vidioc-querycap.rst
> @@ -252,6 +252,11 @@ specification the ioctl returns an ``EINVAL`` error code.
> * - ``V4L2_CAP_TOUCH``
> - 0x10000000
> - This is a touch device.
> + * - ``V4L2_MC_CENTRIC``
> + - 0x20000000
> + - Indicates that the device require **mc-centric** hardware
MC-centric
> + control, and thus can't be used by **v4l2-centric** applications.
vdev-centric
TBD: I still think I prefer V4L2-centric over vdev-centric.
> + See :ref:`v4l2_hardware_control` for more details.
> * - ``V4L2_CAP_DEVICE_CAPS``
> - 0x80000000
> - The driver fills the ``device_caps`` field. This capability can
> diff --git a/Documentation/media/videodev2.h.rst.exceptions b/Documentation/media/videodev2.h.rst.exceptions
> index a5cb0a8686ac..b51a575f9f75 100644
> --- a/Documentation/media/videodev2.h.rst.exceptions
> +++ b/Documentation/media/videodev2.h.rst.exceptions
> @@ -157,6 +157,7 @@ replace define V4L2_CAP_META_CAPTURE device-capabilities
> replace define V4L2_CAP_READWRITE device-capabilities
> replace define V4L2_CAP_ASYNCIO device-capabilities
> replace define V4L2_CAP_STREAMING device-capabilities
> +replace define V4L2_CAP_MC_CENTRIC device-capabilities
> replace define V4L2_CAP_DEVICE_CAPS device-capabilities
> replace define V4L2_CAP_TOUCH device-capabilities
>
> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> index 45cf7359822c..7b490fe97980 100644
> --- a/include/uapi/linux/videodev2.h
> +++ b/include/uapi/linux/videodev2.h
> @@ -460,6 +460,8 @@ struct v4l2_capability {
>
> #define V4L2_CAP_TOUCH 0x10000000 /* Is a touch device */
>
> +#define V4L2_CAP_MC_CENTRIC 0x20000000 /* Device require mc-centric hardware control */
requires
MC-centric
> +
> #define V4L2_CAP_DEVICE_CAPS 0x80000000 /* sets device capabilities field */
>
> /*
>
Regards,
Hans
