linux/Documentation/devicetree/bindings/phy/rockchip-emmc-phy.txt

Rockchip EMMC PHY
-----------------------

Required properties:
 - compatible: rockchip,rk3399-emmc-phy
 - rockchip,grf : phandle to the syscon managing the "general
   register files"
 - #phy-cells: must be 0
 - reg: PHY configure reg address offset in "general
   register files"

Example:

emmcphy: phy {
	compatible = "rockchip,rk3399-emmc-phy";
	rockchip,grf = <&grf>;
	reg = <0xf780>;
	#phy-cells = <0>;
};