Re: [PATCH v2 02/10] media: v4l2-ctrl: Document V4L2_CID_CAMERA_SENSOR_LOCATION

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Jacopo,

Thank you for the patch.

On Tue, Aug 27, 2019 at 11:23:28AM +0200, Jacopo Mondi wrote:
> Add documentation for the V4L2_CID_CAMERA_SENSOR_LOCATION camera
> control. The newly added read-only control reports the camera device
> mounting position.
> 
> Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>
> ---
>  .../media/uapi/v4l/ext-ctrls-camera.rst       | 34 +++++++++++++++++++
>  1 file changed, 34 insertions(+)
> 
> diff --git a/Documentation/media/uapi/v4l/ext-ctrls-camera.rst b/Documentation/media/uapi/v4l/ext-ctrls-camera.rst
> index 51c1d5c9eb00..ecf151f3f0f4 100644
> --- a/Documentation/media/uapi/v4l/ext-ctrls-camera.rst
> +++ b/Documentation/media/uapi/v4l/ext-ctrls-camera.rst
> @@ -510,6 +510,40 @@ enum v4l2_scene_mode -
>      value down. A value of zero stops the motion if one is in progress
>      and has no effect otherwise.
>  
> +``V4L2_CID_CAMERA_SENSOR_LOCATION (integer)``
> +    This read-only control describes the camera sensor location by
> +    reporting its mounting position on the device where the camera is
> +    installed. The control value is constant and not modifiable by software
> +    and its value is retrieved from the firmware interface by parsing the
> +    'location' property.

How the value is known to the driver is irrelevant in this context, I
would drop "and its value ...".

> This control is particularly meaningful for
> +    devices which have a well defined orientation, such as phones, laptops
> +    and portable devices as the camera location is expressed as a position
> +    relative to the device intended usage orientation. In example, a camera

s/In example/For example/

> +    sensor installed on the user-facing side of a phone, a tablet or a
> +    laptop device is said to be installed in the ``V4L2_LOCATION_FRONT``
> +    location while camera sensors installed on the side opposed to the

s/opposed to the front one/opposite the front/

> +    front one are said to be installed in the ``V4L2_LOCATION_BACK``
> +    location. Camera sensors connected to the device by extension cables
> +    which are freely movable regardless of the device orientation, such as
> +    webcams and digital cameras, are said to be have
> +    ``V4L2_LOCATION_EXTERNAL`` location.

Same comment as for the DT bindings regarding cables.

> +
> +
> +
> +.. flat-table::
> +    :header-rows:  0
> +    :stub-columns: 0
> +
> +    * - ``V4L2_LOCATION_FRONT``
> +      - The camera sensor is located on the front side of the device.
> +    * - ``V4L2_LOCATION_BACK``
> +      - The camera sensor is located on the back side of the device.
> +    * - ``V4L2_LOCATION_EXTERNAL``
> +      - The camera sensor is connected by extension cables to the device and
> +        it's freely movable.

s/it's/is/

> +
> +
> +
>  .. [#f1]
>     This control may be changed to a menu control in the future, if more
>     options are required.

-- 
Regards,

Laurent Pinchart