usb: mtu3: dual-role mode support

support dual-role mode; there are two ways to switch between
host and device modes, one is by idpin, another is by debugfs
which depends on user input.

Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/mtu3/mtu3_host.c

@@ -230,10 +230,16 @@ static void ssusb_host_setup(struct ssusb_mtk *ssusb)
 	 * if support OTG, gadget driver will switch port0 to device mode
 	 */
 	ssusb_host_enable(ssusb);
+
+	/* if port0 supports dual-role, works as host mode by default */
+	ssusb_set_vbus(&ssusb->otg_switch, 1);
 }
 
 static void ssusb_host_cleanup(struct ssusb_mtk *ssusb)
 {
+	if (ssusb->is_host)
+		ssusb_set_vbus(&ssusb->otg_switch, 0);
+
 	ssusb_host_disable(ssusb, false);
 }