linux-arkmicro/linux/Documentation/devicetree/bindings/usb/usb-hcd.txt

Generic USB HCD (Host Controller Device) Properties

Optional properties:
- phys: a list of all USB PHYs on this HCD

Example:
	&usb1 {
		phys = <&usb2_phy1>, <&usb3_phy1>;
	};