dt-bindings: Add support for M31 EUSB2 phy

Add support and documentation of M31 EUSB2 phy.

Change-Id: Ifccecb4743a4d8f000c3c193116c923d0e8fb3c5

bindings/usb/qcom,usb-m31-eusb2-phy.txt

@@ -0,0 +1,57 @@
+Qualcomm Technologies, Inc. eUSB2 M31 USB HSPHY
+
+Required properties:
+ - compatible: Should be "qcom,usb-m31-eusb2-phy"
+ - reg: Address and length of the register set for the device
+   Required regs are:
+	"eusb2_phy_base" : the base register for the PHY
+	"eud_detect_reg" : VIOCTL_EUD_DETECT register
+
+ - <supply-name>-supply: phandle to the regulator device tree node
+   Required "supply-name" examples are:
+	"vdd" : vdd supply for HSPHY digital circuit operation
+	"vdda12" : 1.2v supply for HSPHY
+ - clocks: a list of phandles to the PHY clocks. Use as per
+   Documentation/devicetree/bindings/clock/clock-bindings.txt
+   Required clocks are:
+	"ref_clk_src" : the XO clock for eusb2_phy
+	"ref_clk"     : the repeater/receiver(abstracted as clock)
+
+ - clock-names: Names of the clocks in 1-1 correspondence with the "clocks"
+   property. "ref_clk_src" & "ref_clk" are mandatory clocks.
+ - qcom,vdd-voltage-level: This property must be a list of three integer
+   values (no, min, max) where each value represents either a voltage in
+   microvolts or a value corresponding to voltage corner.
+ - resets: reset specifier pair consists of phandle for the reset controller
+   and reset lines used by this controller.
+ - reset-names: reset signal name strings sorted in the same order as the resets
+   property.
+ - usb-repeater: phandle to eUSB2 repeater which is used with eUSB2 HSPHY for USB
+   functionality.
+ - reg-names: Names of the registers in 1-1 correspondence with "reg".
+
+Optional properties:
+ - qcom,param-override-seq: parameter override sequence with value, reg offset
+   pair.
+ - reg: Address and length of the register set for the device
+   Optional regs are:
+        "eud_enable_reg" : register address to read eud enable/disable status.
+ - dummy-supply: phandle to eUSB2 repeater for enforcing probe ordering for
+   eUSB2 repeater and eUSB2 PHY driver.
+
+Example:
+	hsphy@88e3000 {
+		compatible = "qcom,usb-m31-eusb2-phy";
+		reg = <0x88e3000 0x154>;
+		reg-names = "eusb2_phy_base";
+		vdd-supply = <&pm8841_s2_corner>;
+		vdda12-supply = <&pm8941_l6>;
+		qcom,vdd-voltage-level = <0 880000 880000>;
+		qcom,param-override-seq = <0x43 0x70>;
+		usb-repeater= <&pm8550b_eusb2_repeater>;
+		clocks = <&rpmhcc RPMH_CXO_PAD_CLK>,
+			<&tcsrcc TCSR_USB2_CLKREF_EN>;
+		clock-names = "ref_clk_src", "ref_clk";
+		resets = <&gcc GCC_QUSB2PHY_PRIM_BCR>;
+		reset-names = "phy_reset";
+	};