usb: musb: sunxi: Add support for the Allwinner sunxi musb controller

This is based on initial code to get the Allwinner sunxi musb controller
supported by Chen-Yu Tsai and Roman Byshko.

This adds support for the Allwinner sunxi musb controller in both host only
and otg mode. Peripheral only mode is not supported, as no boards use that.

This has been tested on a cubietruck (A20 SoC) and an UTOO P66 tablet
(A13 SoC) with a variety of devices in host mode and with the g_serial gadget
driver in peripheral mode, plugging otg / host cables in/out a lot of times
in all possible imaginable plug orders.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

Documentation/devicetree/bindings/usb/allwinner,sun4i-a10-musb.txt

+Allwinner sun4i A10 musb DRC/OTG controller
+-------------------------------------------
+
+Required properties:
+ - compatible      : "allwinner,sun4i-a10-musb"
+ - reg             : mmio address range of the musb controller
+ - clocks          : clock specifier for the musb controller ahb gate clock
+ - interrupts      : interrupt to which the musb controller is connected
+ - interrupt-names : must be "mc"
+ - phys            : phy specifier for the otg phy
+ - phy-names       : must be "usb"
+ - dr_mode         : Dual-Role mode must be "host" or "otg"
+ - extcon          : extcon specifier for the otg phy
+
+Example:
+
+	usb_otg: usb@01c13000 {
+		compatible = "allwinner,sun4i-a10-musb";
+		reg = <0x01c13000 0x0400>;
+		clocks = <&ahb_gates 0>;
+		interrupts = <38>;
+		interrupt-names = "mc";
+		phys = <&usbphy 0>;
+		phy-names = "usb";
+		extcon = <&usbphy 0>;
+		status = "disabled";
+	};

drivers/usb/musb/Kconfig

@@ -5,7 +5,7 @@
 
 # (M)HDRC = (Multipoint) Highspeed Dual-Role Controller
 config USB_MUSB_HDRC
-	tristate 'Inventra Highspeed Dual Role Controller (TI, ADI, ...)'
+	tristate 'Inventra Highspeed Dual Role Controller (TI, ADI, AW, ...)'
 	depends on (USB || USB_GADGET)
 	help
 	  Say Y here if your system has a dual role high speed USB
@@ -20,6 +20,8 @@ config USB_MUSB_HDRC
 	  Analog Devices parts using this IP include Blackfin BF54x,
 	  BF525 and BF527.
 
+	  Allwinner SoCs using this IP include A10, A13, A20, ...
+
 	  If you do not know what this is, please say N.
 
 	  To compile this driver as a module, choose M here; the
@@ -60,6 +62,15 @@ endchoice
 
 comment "Platform Glue Layer"
 
+config USB_MUSB_SUNXI
+	tristate "Allwinner (sunxi)"
+	depends on ARCH_SUNXI
+	depends on NOP_USB_XCEIV
+	depends on PHY_SUN4I_USB
+	depends on EXTCON
+	depends on GENERIC_PHY
+	select SUNXI_SRAM
+
 config USB_MUSB_DAVINCI
 	tristate "DaVinci"
 	depends on ARCH_DAVINCI_DMx

drivers/usb/musb/Makefile

@@ -20,6 +20,7 @@ obj-$(CONFIG_USB_MUSB_DA8XX)			+= da8xx.o
 obj-$(CONFIG_USB_MUSB_BLACKFIN)			+= blackfin.o
 obj-$(CONFIG_USB_MUSB_UX500)			+= ux500.o
 obj-$(CONFIG_USB_MUSB_JZ4740)			+= jz4740.o
+obj-$(CONFIG_USB_MUSB_SUNXI)			+= sunxi.o
 
 
 obj-$(CONFIG_USB_MUSB_AM335X_CHILD)		+= musb_am335x.o