rk3399 — dwc3 dts配置

关键词： rk3399; rockchip,rk3399-dwc3; 

rk3399 — dwc3 dts配置，dwc3是 USB SoC 控制器，其dts配置如下：

1、必须配置属性：

- compatible:	compatible 名字为"rockchip,rk3399-dwc3"
- clocks:	指定dwc3需要使用的clocks，与clock-names一一对应。
- clock-names:	clock-names，取如下四个名字，四种clock 源。
  "ref_clk"	控制器的参照clk，必须是24MHz.
  "suspend_clk"	控制器的待机clk，必须是24MHz,或者是32KHz.
  "bus_clk"	主clock，超高速，clock必须>=62.5MHz, 高速,clock必须>=30Mhz.
  "grf_clk"	控制器的grf clk.

2、可选属性：

- needs-reset-on-resume: 用于设置DWM3的待机唤醒复位。

3、以rk3399为例：

	usbdrd3_0: usb@fe800000 {
		compatible = "rockchip,rk3399-dwc3";
		clocks = <&cru SCLK_USB3OTG0_REF>, <&cru SCLK_USB3OTG0_SUSPEND>,
			 <&cru ACLK_USB3OTG0>, <&cru ACLK_USB3_GRF>;
		clock-names = "ref_clk", "suspend_clk",
			      "bus_clk", "grf_clk";
		#address-cells = <2>;
		#size-cells = <2>;
		ranges;
		status = "disabled";
		usbdrd_dwc3_0: dwc3@fe800000 {
			compatible = "snps,dwc3";
			reg = <0x0 0xfe800000 0x0 0x100000>;
			interrupts = <GIC_SPI 105 IRQ_TYPE_LEVEL_HIGH>;
			dr_mode = "otg";
			status = "disabled";
		};
	};

	usbdrd3_1: usb@fe900000 {
		compatible = "rockchip,rk3399-dwc3";
		clocks = <&cru SCLK_USB3OTG1_REF>, <&cru SCLK_USB3OTG1_SUSPEND>,
			 <&cru ACLK_USB3OTG1>, <&cru ACLK_USB3_GRF>;
		clock-names = "ref_clk", "suspend_clk",
			      "bus_clk", "grf_clk";
		#address-cells = <2>;
		#size-cells = <2>;
		ranges;
		status = "disabled";
		usbdrd_dwc3_1: dwc3@fe900000 {
			compatible = "snps,dwc3";
			reg = <0x0 0xfe900000 0x0 0x100000>;
			interrupts = <GIC_SPI 110 IRQ_TYPE_LEVEL_HIGH>;
			dr_mode = "otg";
			status = "disabled";
		};
	};