Re: [PATCH 20/20] arch: dts: Fix DWC USB3 DT nodes name

[Serge Semin]

On Thu, Oct 15, 2020 at 01:15:37PM +0300, Felipe Balbi wrote:
> Serge Semin <Sergey.Semin@xxxxxxxxxxxxxxxxxxxx> writes:
> 
> > On Wed, Oct 14, 2020 at 05:09:37PM +0300, Felipe Balbi wrote:
> >> 
> >> Hi Serge,
> >> 
> >> Serge Semin <Sergey.Semin@xxxxxxxxxxxxxxxxxxxx> writes:
> >> > In accordance with the DWC USB3 bindings the corresponding node name is
> >> > suppose to comply with Generic USB HCD DT schema, which requires the USB
> >> 
> >
> >> DWC3 is not a simple HDC, though.
> >
> > Yeah, strictly speaking it is equipped with a lot of vendor-specific stuff,
> > which are tuned by the DWC USB3 driver in the kernel. But after that the
> > controller is registered as xhci-hcd device so it's serviced by the xHCI driver,
> 

> in Dual-role or host-only builds, that's correct. We can also have
> peripheral-only builds (both SW or HW versions) which means xhci isn't
> even in the picture.

Hm, good point. In that case perhaps we'll need to apply the xHCI DT schema
conditionally. Like this:

- allOf:
-   - $ref: usb-xhci.yaml#
+ allOf:
+   - if:
+       properties:
+         dr_mode:
+           const: peripheral
+     then:
+       $ref: usb-hcd.yaml#
+     else:
+       $ref: usb-xhci.yaml#

Note, we need to have the peripheral device being compatible with the
usb-hcd.yaml schema to support the maximum-speed, dr_mode properties and to
comply with the USB node naming constraint.

-Sergey

> 
> -- 
> balbi