usb: chipidea: msm: Use USB PHY API to control PHY state

PHY drivers keep track of the current state of the hardware,
so don't change PHY settings under it.

Cc: 3.16+ <stable@vger.kernel.org>
Cc: Tim Bird <tbird20d@gmail.com>
Signed-off-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Ivan T. Ivanov <iivanov@mm-sol.com>
Acked-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/chipidea/ci_hdrc_msm.c

@@ -20,7 +20,6 @@
 static void ci_hdrc_msm_notify_event(struct ci_hdrc *ci, unsigned event)
 {
 	struct device *dev = ci->gadget.dev.parent;
-	int val;
 
 	switch (event) {
 	case CI_HDRC_CONTROLLER_RESET_EVENT:
@@ -34,10 +33,7 @@ static void ci_hdrc_msm_notify_event(struct ci_hdrc *ci, unsigned event)
 		 * Put the transceiver in non-driving mode. Otherwise host
 		 * may not detect soft-disconnection.
 		 */
-		val = usb_phy_io_read(ci->transceiver, ULPI_FUNC_CTRL);
-		val &= ~ULPI_FUNC_CTRL_OPMODE_MASK;
-		val |= ULPI_FUNC_CTRL_OPMODE_NONDRIVING;
-		usb_phy_io_write(ci->transceiver, val, ULPI_FUNC_CTRL);
+		usb_phy_notify_disconnect(ci->transceiver, USB_SPEED_UNKNOWN);
 		break;
 	default:
 		dev_dbg(dev, "unknown ci_hdrc event\n");