dm: usb: Allow usb host drivers to implement usb_reset_root_port

Allow usb uclass host drivers to implement usb_reset_root_port, this is
used by single port usb hosts which do not emulate a hub, such as otg
controllers.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Simon Glass <sjg@chromium.org>

drivers/usb/host/usb-uclass.c

@@ -128,6 +128,17 @@ int usb_alloc_device(struct usb_device *udev)
 	return ops->alloc_device(bus, udev);
 }
 
+int usb_reset_root_port(struct usb_device *udev)
+{
+	struct udevice *bus = udev->controller_dev;
+	struct dm_usb_ops *ops = usb_get_ops(bus);
+
+	if (!ops->reset_root_port)
+		return -ENOSYS;
+
+	return ops->reset_root_port(bus, udev);
+}
+
 int usb_stop(void)
 {
 	struct udevice *bus;
@@ -268,11 +279,6 @@ int usb_init(void)
 	return usb_started ? 0 : -1;
 }
 
-int usb_reset_root_port(struct usb_device *udev)
-{
-	return -ENOSYS;
-}
-
 static struct usb_device *find_child_devnum(struct udevice *parent, int devnum)
 {
 	struct usb_device *udev;

include/usb.h

@@ -705,6 +705,11 @@ struct dm_usb_ops {
 	 * is read). This should be NULL for EHCI, which does not need this.
 	 */
 	int (*alloc_device)(struct udevice *bus, struct usb_device *udev);
+
+	/**
+	 * reset_root_port() - Reset usb root port
+	 */
+	int (*reset_root_port)(struct udevice *bus, struct usb_device *udev);
 };
 
 #define usb_get_ops(dev)	((struct dm_usb_ops *)(dev)->driver->ops)