1 files changed, 85 insertions, 0 deletions
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);
+}