usb: dwc3: make usb2 phy utmi interface configurable

Support to configure the UTMI+ PHY with an 8- or 16-bit
interface via DT. The UTMI+ PHY interface is a hardware
capability, and it's platform dependent. Normally, the
PHYIF can be configured during coreconsultant.

But for some specific USB cores(e.g. rk3399 SoC DWC3),
the default PHYIF configuration value is false, so we
need to reconfigure it by software.

Signed-off-by: William Wu <william.wu@rock-chips.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 0b7bfd2..edbca03 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -485,6 +485,23 @@
 		break;
 	}
 
+	switch (dwc->hsphy_mode) {
+	case USBPHY_INTERFACE_MODE_UTMI:
+		reg &= ~(DWC3_GUSB2PHYCFG_PHYIF_MASK |
+		       DWC3_GUSB2PHYCFG_USBTRDTIM_MASK);
+		reg |= DWC3_GUSB2PHYCFG_PHYIF(UTMI_PHYIF_8_BIT) |
+		       DWC3_GUSB2PHYCFG_USBTRDTIM(USBTRDTIM_UTMI_8_BIT);
+		break;
+	case USBPHY_INTERFACE_MODE_UTMIW:
+		reg &= ~(DWC3_GUSB2PHYCFG_PHYIF_MASK |
+		       DWC3_GUSB2PHYCFG_USBTRDTIM_MASK);
+		reg |= DWC3_GUSB2PHYCFG_PHYIF(UTMI_PHYIF_16_BIT) |
+		       DWC3_GUSB2PHYCFG_USBTRDTIM(USBTRDTIM_UTMI_16_BIT);
+		break;
+	default:
+		break;
+	}
+
 	/*
 	 * Above 1.94a, it is recommended to set DWC3_GUSB2PHYCFG_SUSPHY to
 	 * '0' during coreConsultant configuration. So default value will
@@ -891,6 +908,7 @@
 
 	dwc->maximum_speed = usb_get_maximum_speed(dev);
 	dwc->dr_mode = usb_get_dr_mode(dev);
+	dwc->hsphy_mode = of_usb_get_phy_mode(dev->of_node);
 
 	dwc->has_lpm_erratum = device_property_read_bool(dev,
 				"snps,has-lpm-erratum");