On Thu, Dec 12, 2024 at 03:03:51PM +0100, Greg KH wrote: > On Thu, Dec 12, 2024 at 02:42:34PM +0100, Ricardo Ribalda wrote: > > Hi all, > > > > I'm working on a way to annotate the location of a USB device within a > > system, specifically whether it's "user-facing" or "world-facing." > > > > There's precedent for this type of annotation: > > > > - ACPI: Uses the '_PLD' property for this purpose > > (https://uefi.org/htmlspecs/ACPI_Spec_6_4_html/06_Device_Configuration/Device_Configuration.html#pld-physical-location-of-device). > > We already leverage this for MIPI camera sensors > > (https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/media/pci/intel/ipu-bridge.c#n265). > > > > - Device Tree : Has a property for this within > > video-interface-devices.yaml > > (https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/media/video-interface-devices.yaml#n386). > > > > I propose adding a similar property to usb-device.yaml > > (https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/usb/usb-device.yaml). > > > > The ultimate goal is to have this information consumed by the video > > driver and exposed to userspace via the V4L2_CID_CAMERA_ORIENTATION > > control (https://www.kernel.org/doc/html/latest/userspace-api/media/v4l/ext-ctrls-camera.html). > > > > What do you think about this? > > I think you should copy what ACPI does here, as long as it doesn't > conflict with the existing video-interface-devices.yaml definition. Right. While the notions of "user-facing" and "world-facing" might make sense for cameras, they do not make sense for arbitrary USB devices. So they shouldn't be part of the general USB device description. Alan Stern > Will that work? > > thanks, > > greg k-h >
