Re: [PATCH] dt-bindings: usb: usb-device: Add panel-location

Ricardo Ribalda
2024-12-19T12:42:24Z

On Thu, 19 Dec 2024 at 13:24, Rob Herring <robh@kernel.org> wrote:
>
> On Tue, Dec 17, 2024 at 04:24:27PM +0100, Ricardo Ribalda wrote:
> > Hi Rob
> >
> > On Tue, 17 Dec 2024 at 16:02, Rob Herring <robh@kernel.org> wrote:
> > >
> > > On Thu, Dec 12, 2024 at 09:44:37PM +0000, Ricardo Ribalda wrote:
> > > > For some devices like cameras the system needs to know where they are
> > > > mounted.
> > >
> > > Why do you need this and why only this property and not the dozens
> > > others ACPI has?
> >
> > Userspace needs that information to correctly show it in the UI. Eg;
> >
> > - User facing camera needs to be mirrored during preview.
> > - The user facing camera is selected by default during videoconferences
> > - The world facing camera is selected by default when taking a photo
> > - User facing camera have different parameter defaults than world facing.
>
> We already have "orientation" defined for this purpose.

Do you mean orientation from
bindings/media/video-interface-devices.yaml ?

I see a couple of issues:
- Orientation has a very specific meaning for USB typeC. I'd prefer if
we could avoid using that word.
- For other applications different than cameras it might be useful to
know the positions top, bottom, left, right, which are not available
in video-interface-devices
- The value "external" does not makes too much sense for listed usb devices
- It makes our lives easier if dt and acpi have the same meaning (less
conversion)

All that said, for my specific usecase, reusing orientation from
bindings/media/video-interface-devices.yaml works... So if that is
what you all prefer I can send a v2 with that.
Let me know what you think

>
> >
> > Right now, the only camera driver that expose the ACPI location
> > information is the IPU from intel
> > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/media/pci/intel/ipu-bridge.c#n258
> >
> > And they are only using the panel.
> >
> > If we need more information we can consider adding more parameters in
> > the future.

--
Ricardo Ribalda