usb: host: ehci-st: Add ehci-st devicetree bindings documentation

This patch documents the device tree bindings required for the
ehci on-chip controller found in ST consumer electronics SoC's.

Signed-off-by: Peter Griffin <peter.griffin@linaro.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/Documentation/devicetree/bindings/usb/ehci-st.txt b/Documentation/devicetree/bindings/usb/ehci-st.txt
new file mode 100644 (file)
index 0000000..fb45fa5
--- /dev/null
+++ b/Documentation/devicetree/bindings/usb/ehci-st.txt
@@ -0,0 +1,39 @@
+ST USB EHCI controller
+
+Required properties:
+ - compatible          : must be "st,st-ehci-300x"
+ - reg                 : physical base addresses of the controller and length of memory mapped
+                         region
+ - interrupts          : one EHCI interrupt should be described here
+ - pinctrl-names       : a pinctrl state named "default" must be defined
+ - pinctrl-0           : phandle referencing pin configuration of the USB controller
+See: Documentation/devicetree/bindings/pinctrl/pinctrl-binding.txt
+ - clocks              : phandle list of usb clocks
+ - clock-names         : should be "ic" for interconnect clock and "clk48"
+See: Documentation/devicetree/bindings/clock/clock-bindings.txt
+
+ - phys                        : phandle for the PHY device
+ - phy-names           : should be "usb"
+ - resets              : phandle + reset specifier pairs to the powerdown and softreset lines
+                         of the USB IP
+ - reset-names         : should be "power" and "softreset"
+See: Documentation/devicetree/bindings/reset/st,sti-powerdown.txt
+See: Documentation/devicetree/bindings/reset/reset.txt
+
+Example:
+
+       ehci1: usb@0xfe203e00 {
+               compatible = "st,st-ehci-300x";
+               reg = <0xfe203e00 0x100>;
+               interrupts = <GIC_SPI 148 IRQ_TYPE_NONE>;
+               pinctrl-names = "default";
+               pinctrl-0 = <&pinctrl_usb1>;
+               clocks = <&clk_s_a1_ls 0>;
+               phys = <&usb2_phy>;
+               phy-names = "usb";
+               status = "okay";
+
+               resets = <&powerdown STIH416_USB1_POWERDOWN>,
+                        <&softreset STIH416_USB1_SOFTRESET>;
+               reset-names = "power", "softreset";
+       };