usb_of_get_device_node
port_np = usb_of_get_device_node(usb_dev, port1);
child = usb_of_get_device_node(hub, port1);
EXPORT_SYMBOL_GPL(usb_of_get_device_node);
dev->dev.of_node = usb_of_get_device_node(parent, raw_port);
np = usb_of_get_device_node(parent_hub, i);
struct device_node *usb_of_get_device_node(struct usb_device *hub, int port1);