On Thu, Aug 15, 2019 at 04:15:10PM +0300, Sakari Ailus wrote: > On Thu, Aug 15, 2019 at 04:10:53PM +0300, Laurent Pinchart wrote: > > On Thu, Aug 15, 2019 at 04:08:49PM +0300, Sakari Ailus wrote: > >> On Thu, Aug 15, 2019 at 03:59:38PM +0300, Laurent Pinchart wrote: > >>> On Thu, Aug 15, 2019 at 10:00:25AM +0300, Sakari Ailus wrote: > >>>> On Wed, Aug 14, 2019 at 10:28:12PM +0200, Jacopo Mondi wrote: > >>>>> Add documentation for the V4L2_CID_LOCATION camera control. The newly > >>>>> added read-only control reports the camera device mounting position. > >>>>> > >>>>> Signed-off-by: Jacopo Mondi <jac...@jmondi.org> > >>>>> --- > >>>>> .../media/uapi/v4l/ext-ctrls-camera.rst | 23 +++++++++++++++++++ > >>>>> 1 file changed, 23 insertions(+) > >>>>> > >>>>> diff --git a/Documentation/media/uapi/v4l/ext-ctrls-camera.rst > >>>>> b/Documentation/media/uapi/v4l/ext-ctrls-camera.rst > >>>>> index 51c1d5c9eb00..fc0a02eee6d4 100644 > >>>>> --- a/Documentation/media/uapi/v4l/ext-ctrls-camera.rst > >>>>> +++ b/Documentation/media/uapi/v4l/ext-ctrls-camera.rst > >>>>> @@ -510,6 +510,29 @@ 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_LOCATION (integer)`` > >>>>> + This read-only control describes the camera location by reporting > >>>>> its > >>>>> + mounting position on the device where the camera is installed. 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 position. In example, a camera installed on the user-facing > >>>>> side > >>>> > >>>> s/In/For/ > >>>> > >>>>> + of a phone device is said to be installed in the > >>>>> ``V4L2_LOCATION_FRONT`` > >>>>> + position. > >>>>> + > >>>>> + > >>>>> + > >>>>> +.. flat-table:: > >>>>> + :header-rows: 0 > >>>>> + :stub-columns: 0 > >>>>> + > >>>>> + * - ``V4L2_LOCATION_FRONT`` > >>>>> + - The camera device is located on the front side of the device. > >>>>> + * - ``V4L2_LOCATION_BACK`` > >>>>> + - The camera device is located on the back side of the device. > >>>>> + > >>>>> + > >>>>> + > >>>>> .. [#f1] > >>>>> This control may be changed to a menu control in the future, if more > >>>>> options are required. > >>>> > >>>> There's an effective limit of 64 for menus. ACPI has less than ten > >>>> different locations for a device, I think 64 will be enough here. > >>>> > >>>> So I'd be actually in favour of switching to a menu. > >>> > >>> Why ? As you explained yourself, it's a static read-only control, all it > >>> needs to report is a single value. > >> > >> Yes. That's true. It wasn't meant for this but it's nevertheless a > >> convenient API to get that information, both as integer and string. > > > > But why is that needed ? The integer seems enough to me. > > Because it's a qualitative control, not a quantitative one.
And ? :-) The integer values are defined in the V4L2 spec, they map to a usage, and a name can easily be derived from that in userspace if desired. -- Regards, Laurent Pinchart
