Hi Jacopo, On Mon, Sep 02, 2019 at 06:40:31PM +0200, Jacopo Mondi wrote: > On Mon, Sep 02, 2019 at 02:38:40PM +0100, Rob Herring wrote: > > On Thu, Aug 29, 2019 at 02:46:40PM +0200, Jacopo Mondi wrote: > >> On Tue, Aug 27, 2019 at 03:21:26PM +0300, Laurent Pinchart wrote: > >>> On Tue, Aug 27, 2019 at 11:23:27AM +0200, Jacopo Mondi wrote: > >>>> Add the 'location' device property, used to specify the camera device > >>>> mounting position. The property is particularly meaningful for mobile > >>>> devices with a well defined usage orientation. > >>>> > >>>> Signed-off-by: Jacopo Mondi <jacopo@xxxxxxxxxx> > >>>> --- > >>>> .../devicetree/bindings/media/video-interfaces.txt | 10 ++++++++++ > >>>> 1 file changed, 10 insertions(+) > >>>> > >>>> diff --git a/Documentation/devicetree/bindings/media/video-interfaces.txt b/Documentation/devicetree/bindings/media/video-interfaces.txt > >>>> index f884ada0bffc..865f4142f432 100644 > >>>> --- a/Documentation/devicetree/bindings/media/video-interfaces.txt > >>>> +++ b/Documentation/devicetree/bindings/media/video-interfaces.txt > >>>> @@ -89,6 +89,16 @@ Optional properties > >>>> but a number of degrees counter clockwise. Typical values are 0 and 180 > >>>> (upside down). > >>>> > >>>> +- location: The camera sensor mounting location, expressed as a position > >>>> + relative to the usage orientation of the device the sensor is installed on. > >>> > >>> DT bindings being ABIs, we need to be precise and thorough there. One > >>> particular point that bothers me is that the property is named location, > >>> and its description refers to camera sensor mounting location. > >>> > >>> I see two options to fix this. One of them is to rename the property to > >>> camera-location, but that would limit its future usage for other types > >>> of devices. The other one is to document the property as applying to a > >>> "device" instead of a "camera sensor", and add one sentence stating that > >>> this property is valid for camera sensors only. > >>> > >>> This will require finding another name for the device that the device is > >>> mounted on though, as using device twice would be very confusing. > >> > >> I had the same concern, but I cannot find another term to convey > >> this... suggestions? > > > > For accelerometers and/or gyroscopes, we already have 'mount-matrix'. > > Pardon my ignorance, but I could not find it documented. Some binding > files refers to an iio/mount-matrix.txt file which I cannot find. Has > it been removed? Anyway, some individual bindings report examples of > mount matrices (ie > Documentation/devicetree/bindings/iio/imu/inv_mpu6050.txt) > > > That would replace 'rotation'. Maybe we can do something similar here? > > I think 'rotation' simply expressed as degrees is fine here, our > problem was to find a term that would make it possible to specify that > rotation/location are applied to a 'device' mounted on a 'device'. > Sakari suggested on irc to use 'system' in place of the second > 'device' and that seems to work well to me. > > Or were you suggesting to use a construct similar to mount-matrix for > a purpose I didn't get :) ? mount-matrix would allow exposing the rotation in a more generic way, and if there are standard DT bindings, I think this would make sense, especially given that we could have device with camera sensors not mounted parallel to the device side. -- Regards, Laurent Pinchart
