1 files changed, 97 insertions, 1 deletions

diff --git a/drivers/usb/dwc3/drd.c b/drivers/usb/dwc3/drd.c
index c946d64142ad..7db1ffc92bbd 100644
--- a/drivers/usb/dwc3/drd.c
+++ b/drivers/usb/dwc3/drd.c
@@ -476,6 +476,94 @@ static struct extcon_dev *dwc3_get_extcon(struct dwc3 *dwc)
 	return edev;
 }
 
+#if IS_ENABLED(CONFIG_USB_ROLE_SWITCH)
+#define ROLE_SWITCH 1
+static int dwc3_usb_role_switch_set(struct usb_role_switch *sw,
+				    enum usb_role role)
+{
+	struct dwc3 *dwc = usb_role_switch_get_drvdata(sw);
+	u32 mode;
+
+	switch (role) {
+	case USB_ROLE_HOST:
+		mode = DWC3_GCTL_PRTCAP_HOST;
+		break;
+	case USB_ROLE_DEVICE:
+		mode = DWC3_GCTL_PRTCAP_DEVICE;
+		break;
+	default:
+		if (dwc->role_switch_default_mode == USB_DR_MODE_HOST)
+			mode = DWC3_GCTL_PRTCAP_HOST;
+		else
+			mode = DWC3_GCTL_PRTCAP_DEVICE;
+		break;
+	}
+
+	dwc3_set_mode(dwc, mode);
+	return 0;
+}
+
+static enum usb_role dwc3_usb_role_switch_get(struct usb_role_switch *sw)
+{
+	struct dwc3 *dwc = usb_role_switch_get_drvdata(sw);
+	unsigned long flags;
+	enum usb_role role;
+
+	spin_lock_irqsave(&dwc->lock, flags);
+	switch (dwc->current_dr_role) {
+	case DWC3_GCTL_PRTCAP_HOST:
+		role = USB_ROLE_HOST;
+		break;
+	case DWC3_GCTL_PRTCAP_DEVICE:
+		role = USB_ROLE_DEVICE;
+		break;
+	case DWC3_GCTL_PRTCAP_OTG:
+		role = dwc->current_otg_role;
+		break;
+	default:
+		if (dwc->role_switch_default_mode == USB_DR_MODE_HOST)
+			role = USB_ROLE_HOST;
+		else
+			role = USB_ROLE_DEVICE;
+		break;
+	}
+	spin_unlock_irqrestore(&dwc->lock, flags);
+	return role;
+}
+
+static int dwc3_setup_role_switch(struct dwc3 *dwc)
+{
+	struct usb_role_switch_desc dwc3_role_switch = {NULL};
+	const char *str;
+	u32 mode;
+	int ret;
+
+	ret = device_property_read_string(dwc->dev, "role-switch-default-mode",
+					  &str);
+	if (ret >= 0  && !strncmp(str, "host", strlen("host"))) {
+		dwc->role_switch_default_mode = USB_DR_MODE_HOST;
+		mode = DWC3_GCTL_PRTCAP_HOST;
+	} else {
+		dwc->role_switch_default_mode = USB_DR_MODE_PERIPHERAL;
+		mode = DWC3_GCTL_PRTCAP_DEVICE;
+	}
+
+	dwc3_role_switch.fwnode = dev_fwnode(dwc->dev);
+	dwc3_role_switch.set = dwc3_usb_role_switch_set;
+	dwc3_role_switch.get = dwc3_usb_role_switch_get;
+	dwc3_role_switch.driver_data = dwc;
+	dwc->role_sw = usb_role_switch_register(dwc->dev, &dwc3_role_switch);
+	if (IS_ERR(dwc->role_sw))
+		return PTR_ERR(dwc->role_sw);
+
+	dwc3_set_mode(dwc, mode);
+	return 0;
+}
+#else
+#define ROLE_SWITCH 0
+#define dwc3_setup_role_switch(x) 0
+#endif
+
 int dwc3_drd_init(struct dwc3 *dwc)
 {
 	int ret, irq;
@@ -484,7 +572,12 @@ int dwc3_drd_init(struct dwc3 *dwc)
 	if (IS_ERR(dwc->edev))
 		return PTR_ERR(dwc->edev);
 
-	if (dwc->edev) {
+	if (ROLE_SWITCH &&
+	    device_property_read_bool(dwc->dev, "usb-role-switch")) {
+		ret = dwc3_setup_role_switch(dwc);
+		if (ret < 0)
+			return ret;
+	} else if (dwc->edev) {
 		dwc->edev_nb.notifier_call = dwc3_drd_notifier;
 		ret = extcon_register_notifier(dwc->edev, EXTCON_USB_HOST,
 					       &dwc->edev_nb);
@@ -531,6 +624,9 @@ void dwc3_drd_exit(struct dwc3 *dwc)
 {
 	unsigned long flags;
 
+	if (dwc->role_sw)
+		usb_role_switch_unregister(dwc->role_sw);
+
 	if (dwc->edev)
 		extcon_unregister_notifier(dwc->edev, EXTCON_USB_HOST,
 					   &dwc->edev_nb);