dt-bindings: usb: dwc3-xilinx: Add documentation for Versal DWC3 Controller

Add documentation for Versal DWC3 controller. Add required property
'reg' for the same. Also add optional properties for snps,dwc3.
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Manish Narani <manish.narani@xilinx.com>
Link: https://lore.kernel.org/r/1615963949-75320-2-git-send-email-manish.narani@xilinx.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/devicetree/bindings/usb/dwc3-xilinx.txt

 Xilinx SuperSpeed DWC3 USB SoC controller
 
 Required properties:
-- compatible:	Should contain "xlnx,zynqmp-dwc3"
+- compatible:	May contain "xlnx,zynqmp-dwc3" or "xlnx,versal-dwc3"
+- reg:		Base address and length of the register control block
 - clocks:	A list of phandles for the clocks listed in clock-names
 - clock-names:	Should contain the following:
   "bus_clk"	 Master/Core clock, have to be >= 125 MHz for SS
 		 operation and >= 60MHz for HS operation
 
   "ref_clk"	 Clock source to core during PHY power down
+- resets:	A list of phandles for resets listed in reset-names
+- reset-names:
+  "usb_crst"	 USB core reset
+  "usb_hibrst"	 USB hibernation reset
+  "usb_apbrst"	 USB APB reset
 
 Required child node:
 A child node must exist to represent the core DWC3 IP block. The name of
 the node is not important. The content of the node is defined in dwc3.txt.
 
+Optional properties for snps,dwc3:
+- dma-coherent:	Enable this flag if CCI is enabled in design. Adding this
+		flag configures Global SoC bus Configuration Register and
+		Xilinx USB 3.0 IP - USB coherency register to enable CCI.
+- interrupt-names: Should contain the following:
+  "dwc_usb3"	USB gadget mode interrupts
+  "otg"		USB OTG mode interrupts
+  "hiber"	USB hibernation interrupts
+
 Example device node:
 
 		usb@0 {
 			#address-cells = <0x2>;
 			#size-cells = <0x1>;
 			compatible = "xlnx,zynqmp-dwc3";
+			reg = <0x0 0xff9d0000 0x0 0x100>;
 			clock-names = "bus_clk", "ref_clk";
 			clocks = <&clk125>, <&clk125>;
+			resets = <&zynqmp_reset ZYNQMP_RESET_USB1_CORERESET>,
+				 <&zynqmp_reset ZYNQMP_RESET_USB1_HIBERRESET>,
+				 <&zynqmp_reset ZYNQMP_RESET_USB1_APB>;
+			reset-names = "usb_crst", "usb_hibrst", "usb_apbrst";
 			ranges;
 
 			dwc3@fe200000 {
 				compatible = "snps,dwc3";
 				reg = <0x0 0xfe200000 0x40000>;
-				interrupts = <0x0 0x41 0x4>;
+				interrupt-names = "dwc_usb3", "otg", "hiber";
+				interrupts = <0 65 4>, <0 69 4>, <0 75 4>;
+				phys = <&psgtr 2 PHY_TYPE_USB3 0 2>;
+				phy-names = "usb3-phy";
 				dr_mode = "host";
+				dma-coherent;
 			};
 		};