usb: dwc3: ulpi: conditionally resume ULPI PHY

If PHY is suspended by the time we want to issue ULPI transfers, we
will observe timeouts on the ULPI interface. In order to avoid such
issue, let's make sure PHY is resumed before issuing a ULPI transfer.
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/dwc3/ulpi.c

@@ -41,6 +41,12 @@ static int dwc3_ulpi_read(struct device *dev, u8 addr)
 	u32 reg;
 	int ret;
 
+	reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
+	if (reg & DWC3_GUSB2PHYCFG_SUSPHY) {
+		reg &= ~DWC3_GUSB2PHYCFG_SUSPHY;
+		dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
+	}
+
 	reg = DWC3_GUSB2PHYACC_NEWREGREQ | DWC3_ULPI_ADDR(addr);
 	dwc3_writel(dwc->regs, DWC3_GUSB2PHYACC(0), reg);
 
@@ -58,6 +64,12 @@ static int dwc3_ulpi_write(struct device *dev, u8 addr, u8 val)
 	struct dwc3 *dwc = dev_get_drvdata(dev);
 	u32 reg;
 
+	reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
+	if (reg & DWC3_GUSB2PHYCFG_SUSPHY) {
+		reg &= ~DWC3_GUSB2PHYCFG_SUSPHY;
+		dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
+	}
+
 	reg = DWC3_GUSB2PHYACC_NEWREGREQ | DWC3_ULPI_ADDR(addr);
 	reg |= DWC3_GUSB2PHYACC_WRITE | val;
 	dwc3_writel(dwc->regs, DWC3_GUSB2PHYACC(0), reg);