usb: dwc3: use a helper function for operation mode setting

There are two where need to set operational mode:
- during initialization while we decide to run in host,device or DRD
  mode
- at runtime via the debugfs interface.

This patch provides a new function which sets the operational mode and
moves its initialiation to the mode switch instead in the gadget code
itself.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/dwc3/core.c

@@ -103,7 +103,15 @@ void dwc3_put_device_id(int id)
 }
 EXPORT_SYMBOL_GPL(dwc3_put_device_id);
 
-/* -------------------------------------------------------------------------- */
+void dwc3_set_mode(struct dwc3 *dwc, u32 mode)
+{
+	u32 reg;
+
+	reg = dwc3_readl(dwc->regs, DWC3_GCTL);
+	reg &= ~(DWC3_GCTL_PRTCAPDIR(DWC3_GCTL_PRTCAP_OTG));
+	reg |= DWC3_GCTL_PRTCAPDIR(mode);
+	dwc3_writel(dwc->regs, DWC3_GCTL, reg);
+}
 
 /**
  * dwc3_core_soft_reset - Issues core soft reset and PHY reset
@@ -452,20 +460,23 @@ static int __devinit dwc3_probe(struct platform_device *pdev)
 
 	switch (mode) {
 	case DWC3_MODE_DEVICE:
+		dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_DEVICE);
 		ret = dwc3_gadget_init(dwc);
 		if (ret) {
 			dev_err(&pdev->dev, "failed to initialize gadget\n");
 			goto err4;
 		}
 		break;
 	case DWC3_MODE_HOST:
+		dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_HOST);
 		ret = dwc3_host_init(dwc);
 		if (ret) {
 			dev_err(&pdev->dev, "failed to initialize host\n");
 			goto err4;
 		}
 		break;
 	case DWC3_MODE_DRD:
+		dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_OTG);
 		ret = dwc3_host_init(dwc);
 		if (ret) {
 			dev_err(&pdev->dev, "failed to initialize host\n");

drivers/usb/dwc3/core.h

@@ -786,6 +786,8 @@ union dwc3_event {
 #define DWC3_HAS_OTG			BIT(3)
 
 /* prototypes */
+void dwc3_set_mode(struct dwc3 *dwc, u32 mode);
+
 int dwc3_host_init(struct dwc3 *dwc);
 void dwc3_host_exit(struct dwc3 *dwc);
 

drivers/usb/dwc3/debugfs.c

@@ -443,29 +443,26 @@ static ssize_t dwc3_mode_write(struct file *file,
 	struct seq_file		*s = file->private_data;
 	struct dwc3		*dwc = s->private;
 	unsigned long		flags;
-	u32			reg;
+	u32			mode = 0;
 	char			buf[32];
 
 	if (copy_from_user(&buf, ubuf, min_t(size_t, sizeof(buf) - 1, count)))
 		return -EFAULT;
 
-	spin_lock_irqsave(&dwc->lock, flags);
-	reg = dwc3_readl(dwc->regs, DWC3_GCTL);
-
-	reg &= ~(DWC3_GCTL_PRTCAPDIR(DWC3_GCTL_PRTCAP_OTG));
-
 	if (!strncmp(buf, "host", 4))
-		reg |= DWC3_GCTL_PRTCAP(DWC3_GCTL_PRTCAP_HOST);
+		mode |= DWC3_GCTL_PRTCAP_HOST;
 
 	if (!strncmp(buf, "device", 6))
-		reg |= DWC3_GCTL_PRTCAP(DWC3_GCTL_PRTCAP_DEVICE);
+		mode |= DWC3_GCTL_PRTCAP_DEVICE;
 
 	if (!strncmp(buf, "otg", 3))
-		reg |= DWC3_GCTL_PRTCAP(DWC3_GCTL_PRTCAP_OTG);
-
-	dwc3_writel(dwc->regs, DWC3_GCTL, reg);
-	spin_unlock_irqrestore(&dwc->lock, flags);
+		mode |= DWC3_GCTL_PRTCAP_OTG;
 
+	if (mode) {
+		spin_lock_irqsave(&dwc->lock, flags);
+		dwc3_set_mode(dwc, mode);
+		spin_unlock_irqrestore(&dwc->lock, flags);
+	}
 	return count;
 }
 

drivers/usb/dwc3/gadget.c

@@ -1158,9 +1158,7 @@ static int dwc3_gadget_start(struct usb_gadget *g,
 	reg = dwc3_readl(dwc->regs, DWC3_GCTL);
 
 	reg &= ~DWC3_GCTL_SCALEDOWN(3);
-	reg &= ~DWC3_GCTL_PRTCAPDIR(DWC3_GCTL_PRTCAP_OTG);
 	reg &= ~DWC3_GCTL_DISSCRAMBLE;
-	reg |= DWC3_GCTL_PRTCAPDIR(DWC3_GCTL_PRTCAP_DEVICE);
 
 	switch (DWC3_GHWPARAMS1_EN_PWROPT(dwc->hwparams.hwparams0)) {
 	case DWC3_GHWPARAMS1_EN_PWROPT_CLK: