usb: dwc2_udc_otg: support 8-bit interface

Define CONFIG_USB_GADGET_DWC2_OTG_PHY_BUS_WIDTH_8 to allow the
physical interface to be 8-bit (rather than 16-bit).

Signed-off-by: Steve Rae <srae@broadcom.com>

drivers/usb/gadget/Kconfig

@@ -52,6 +52,16 @@ config USB_GADGET_DWC2_OTG
 	  driver to operate in Peripheral mode. This option requires
 	  USB_GADGET to be enabled.
 
+if USB_GADGET_DWC2_OTG
+
+config USB_GADGET_DWC2_OTG_PHY_BUS_WIDTH_8
+	bool "DesignWare USB2.0 HS OTG controller 8-bit PHY bus width"
+	help
+	  Set the Designware USB2.0 high-speed OTG controller
+	  PHY interface width to 8 bits, rather than the default (16 bits).
+
+endif # USB_GADGET_DWC2_OTG
+
 config CI_UDC
 	bool "ChipIdea device controller"
 	select USB_GADGET_DUALSPEED

drivers/usb/gadget/dwc2_udc_otg.c

@@ -415,7 +415,11 @@ static void reconfig_usbd(struct dwc2_udc *dev)
 		|0<<7		/* Ulpi DDR sel*/
 		|0<<6		/* 0: high speed utmi+, 1: full speed serial*/
 		|0<<4		/* 0: utmi+, 1:ulpi*/
+#ifdef CONFIG_USB_GADGET_DWC2_OTG_PHY_BUS_WIDTH_8
+		|0<<3		/* phy i/f  0:8bit, 1:16bit*/
+#else
 		|1<<3		/* phy i/f  0:8bit, 1:16bit*/
+#endif
 		|0x7<<0;	/* HS/FS Timeout**/
 
 	if (dev->pdata->usb_gusbcfg)