5 files changed, 111 insertions, 4 deletions
diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig
index c5aa235863e8..aee55114d269 100644
--- a/drivers/usb/dwc3/Kconfig
+++ b/drivers/usb/dwc3/Kconfig
@@ -41,6 +41,7 @@ config USB_DWC3_GADGET
 config USB_DWC3_DUAL_ROLE
 	bool "Dual Role mode"
 	depends on ((USB=y || USB=USB_DWC3) && (USB_GADGET=y || USB_GADGET=USB_DWC3))
+	depends on (EXTCON=y || EXTCON=USB_DWC3)
 	help
 	  This is the default mode of working of DWC3 controller where
 	  both host and gadget features are enabled.
diff --git a/drivers/usb/dwc3/Makefile b/drivers/usb/dwc3/Makefile
index ffca34029b21..f15fabbd1e59 100644
--- a/drivers/usb/dwc3/Makefile
+++ b/drivers/usb/dwc3/Makefile
@@ -17,6 +17,10 @@ ifneq ($(filter y,$(CONFIG_USB_DWC3_GADGET) $(CONFIG_USB_DWC3_DUAL_ROLE)),)
 	dwc3-y				+= gadget.o ep0.o
 endif
 
+ifneq ($(CONFIG_USB_DWC3_DUAL_ROLE),)
+	dwc3-y				+= drd.o
+endif
+
 ifneq ($(CONFIG_USB_DWC3_ULPI),)
 	dwc3-y				+= ulpi.o
 endif
diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 458e7c6cc002..455d89a1cd6d 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -921,7 +921,12 @@ static int dwc3_core_init_mode(struct dwc3 *dwc)
 		break;
 	case USB_DR_MODE_OTG:
 		INIT_WORK(&dwc->drd_work, __dwc3_set_mode);
-		dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_DEVICE);
+		ret = dwc3_drd_init(dwc);
+		if (ret) {
+			if (ret != -EPROBE_DEFER)
+				dev_err(dev, "failed to initialize dual-role\n");
+			return ret;
+		}
 		break;
 	default:
 		dev_err(dev, "Unsupported mode of operation %d\n", dwc->dr_mode);
@@ -941,9 +946,7 @@ static void dwc3_core_exit_mode(struct dwc3 *dwc)
 		dwc3_host_exit(dwc);
 		break;
 	case USB_DR_MODE_OTG:
-		dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_DEVICE);
-		dwc3_gadget_exit(dwc);
-		flush_work(&dwc->drd_work);
+		dwc3_drd_exit(dwc);
 		break;
 	default:
 		/* do nothing */
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 1fe23e36485f..981c77f5628e 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -785,6 +785,8 @@ struct dwc3_scratchpad_array {
  * @dr_mode: requested mode of operation
  * @current_dr_role: current role of operation when in dual-role mode
  * @desired_dr_role: desired role of operation when in dual-role mode
+ * @edev: extcon handle
+ * @edev_nb: extcon notifier
  * @hsphy_mode: UTMI phy mode, one of following:
  *		- USBPHY_INTERFACE_MODE_UTMI
  *		- USBPHY_INTERFACE_MODE_UTMIW
@@ -898,6 +900,8 @@ struct dwc3 {
 	enum usb_dr_mode	dr_mode;
 	u32			current_dr_role;
 	u32			desired_dr_role;
+	struct extcon_dev	*edev;
+	struct notifier_block	edev_nb;
 	enum usb_phy_interface	hsphy_mode;
 
 	u32			fladj;
@@ -1218,6 +1222,16 @@ static inline int dwc3_send_gadget_generic_command(struct dwc3 *dwc,
 { return 0; }
 #endif
 
+#if IS_ENABLED(CONFIG_USB_DWC3_DUAL_ROLE)
+int dwc3_drd_init(struct dwc3 *dwc);
+void dwc3_drd_exit(struct dwc3 *dwc);
+#else
+static inline int dwc3_drd_init(struct dwc3 *dwc)
+{ return 0; }
+static inline void dwc3_drd_exit(struct dwc3 *dwc)
+{ }
+#endif
+
 /* power management interface */
 #if !IS_ENABLED(CONFIG_USB_DWC3_HOST)
 int dwc3_gadget_suspend(struct dwc3 *dwc);
diff --git a/drivers/usb/dwc3/drd.c b/drivers/usb/dwc3/drd.c
new file mode 100644
index 000000000000..2765c51c7ef5
--- /dev/null
+++ b/drivers/usb/dwc3/drd.c
@@ -0,0 +1,85 @@
+/**
+ * drd.c - DesignWare USB3 DRD Controller Dual-role support
+ *
+ * Copyright (C) 2017 Texas Instruments Incorporated - http://www.ti.com
+ *
+ * Authors: Roger Quadros <rogerq@ti.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2  of
+ * the License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/extcon.h>
+
+#include "debug.h"
+#include "core.h"
+#include "gadget.h"
+
+static void dwc3_drd_update(struct dwc3 *dwc)
+{
+	int id;
+
+	id = extcon_get_state(dwc->edev, EXTCON_USB_HOST);
+	if (id < 0)
+		id = 0;
+
+	dwc3_set_mode(dwc, id ?
+		      DWC3_GCTL_PRTCAP_HOST :
+		      DWC3_GCTL_PRTCAP_DEVICE);
+}
+
+static int dwc3_drd_notifier(struct notifier_block *nb,
+			     unsigned long event, void *ptr)
+{
+	struct dwc3 *dwc = container_of(nb, struct dwc3, edev_nb);
+
+	dwc3_set_mode(dwc, event ?
+		      DWC3_GCTL_PRTCAP_HOST :
+		      DWC3_GCTL_PRTCAP_DEVICE);
+
+	return NOTIFY_DONE;
+}
+
+int dwc3_drd_init(struct dwc3 *dwc)
+{
+	int ret;
+
+	if (dwc->dev->of_node) {
+		if (of_property_read_bool(dwc->dev->of_node, "extcon"))
+			dwc->edev = extcon_get_edev_by_phandle(dwc->dev, 0);
+
+		if (IS_ERR(dwc->edev))
+			return PTR_ERR(dwc->edev);
+
+		dwc->edev_nb.notifier_call = dwc3_drd_notifier;
+		ret = extcon_register_notifier(dwc->edev, EXTCON_USB_HOST,
+					       &dwc->edev_nb);
+		if (ret < 0) {
+			dev_err(dwc->dev, "couldn't register cable notifier\n");
+			return ret;
+		}
+	}
+
+	dwc3_drd_update(dwc);
+
+	return 0;
+}
+
+void dwc3_drd_exit(struct dwc3 *dwc)
+{
+	extcon_unregister_notifier(dwc->edev, EXTCON_USB_HOST,
+				   &dwc->edev_nb);
+
+	dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_DEVICE);
+	flush_work(&dwc->drd_work);
+	dwc3_gadget_exit(dwc);
+}