Documentation: dt-bindings: Add documentation for the Meson USB2 PHYs

Add the documentation for the bindings for the Meson8b and GXBB USB2
PHYs.

Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Acked-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>

diff --git a/Documentation/devicetree/bindings/phy/meson-usb2-phy.txt b/Documentation/devicetree/bindings/phy/meson-usb2-phy.txt
new file mode 100644 (file)
index 0000000..9da5ea2
--- /dev/null
+++ b/Documentation/devicetree/bindings/phy/meson-usb2-phy.txt
@@ -0,0 +1,27 @@
+* Amlogic USB2 PHY
+
+Required properties:
+- compatible:  Depending on the platform this should be one of:
+       "amlogic,meson8b-usb2-phy"
+       "amlogic,meson-gxbb-usb2-phy"
+- reg:         The base address and length of the registers
+- #phys-cells: should be 0 (see phy-bindings.txt in this directory)
+- clocks:      phandle and clock identifier for the phy clocks
+- clock-names: "usb_general" and "usb"
+
+Optional properties:
+- resets:      reference to the reset controller
+- phy-supply:  see phy-bindings.txt in this directory
+
+
+Example:
+
+usb0_phy: usb_phy@0 {
+       compatible = "amlogic,meson-gxbb-usb2-phy";
+       #phy-cells = <0>;
+       reg = <0x0 0x0 0x0 0x20>;
+       resets = <&reset RESET_USB_OTG>;
+       clocks = <&clkc CLKID_USB>, <&clkc CLKID_USB0>;
+       clock-names = "usb_general", "usb";
+       phy-supply = <&usb_vbus>;
+};