arm/dt: add basic usb nodes to tegra device trees

For now they are a minimal binding. It needs to be amended with
vendor-specific settings for phy setup and link tuning, etc.

v2: Added bindings specification and phy_type properties
Signed-off-by: Olof Johansson <olof@lixom.net>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>

Documentation/devicetree/bindings/usb/tegra-usb.txt

+Tegra SOC USB controllers
+
+The device node for a USB controller that is part of a Tegra
+SOC is as described in the document "Open Firmware Recommended
+Practice : Universal Serial Bus" with the following modifications
+and additions :
+
+Required properties :
+ - compatible : Should be "nvidia,tegra20-ehci" for USB controllers
+   used in host mode.
+ - phy_type : Should be one of "ulpi" or "utmi".
+ - nvidia,vbus-gpio : If present, specifies a gpio that needs to be
+   activated for the bus to be powered.

arch/arm/boot/dts/tegra-seaboard.dts

@@ -29,4 +29,8 @@ sdhci@c8000400 {
 	sdhci@c8000600 {
 		support-8bit;
 	};
+
+	usb@c5000000 {
+		nvidia,vbus-gpio = <&gpio 24 0>; /* PD0 */
+	};
 };

arch/arm/boot/dts/tegra20.dtsi

@@ -143,5 +143,26 @@ sdhci@c8000600 {
 		reg = <0xc8000600 0x200>;
 		interrupts = < 63 >;
 	};
+
+	usb@c5000000 {
+		compatible = "nvidia,tegra20-ehci", "usb-ehci";
+		reg = <0xc5000000 0x4000>;
+		interrupts = < 52 >;
+		phy_type = "utmi";
+	};
+
+	usb@c5004000 {
+		compatible = "nvidia,tegra20-ehci", "usb-ehci";
+		reg = <0xc5004000 0x4000>;
+		interrupts = < 53 >;
+		phy_type = "ulpi";
+	};
+
+	usb@c5008000 {
+		compatible = "nvidia,tegra20-ehci", "usb-ehci";
+		reg = <0xc5008000 0x4000>;
+		interrupts = < 129 >;
+		phy_type = "utmi";
+	};
 };