dt-bindings: usb: generic-ehci: Document power-domains property

It is quite common for a generic EHCI block to be embedded in an SoC in
its own power domain.  Hence allow the DTS writer to describe the
controller's position in the power hierarchy, by documenting the
optional presence of a "power-domains" property.

This gets rid of "make dtbs_check" warnings like:

    arch/arm64/boot/dts/renesas/r8a774a1-hihope-rzg2m.dt.yaml: usb@ee080100: 'power-domains' does not match any of the regexes: 'pinctrl-[0-9]+'

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Rob Herring <robh@kernel.org>

diff --git a/Documentation/devicetree/bindings/usb/generic-ehci.yaml b/Documentation/devicetree/bindings/usb/generic-ehci.yaml
index 10edd05872ea25379d2ba02116b0fc1ddedc0161..848eea59bc0030e7845aadf9ac905f78dfecba07 100644 (file)
--- a/Documentation/devicetree/bindings/usb/generic-ehci.yaml
+++ b/Documentation/devicetree/bindings/usb/generic-ehci.yaml
@@ -36,6 +36,9 @@ properties:
         - if a USB DRD channel: first clock should be host and second
           one should be peripheral
 
+  power-domains:
+    maxItems: 1
+
   big-endian:
     $ref: /schemas/types.yaml#/definitions/flag
     description: