usb: phy: fsm: update OTG HNP state transition conditions according to OTG and EH 2.0 spec.

According to:"On-The-Go and Embedded Host Supplement to the USB Revision 2.0
Specification July 27, 2012 Revision 2.0 version 1.1a"
- From a_host to a_wait_bcon if !b_conn
- Add transition from a_host to a_wait_vfall if id state is high or a_bus_drop
- From a_wait_vfall to a_idle if a_wait_vfall_tmout

Signed-off-by: Li Jun <b47624@freescale.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/phy/phy-fsm-usb.c

@@ -317,10 +317,12 @@ int otg_statemachine(struct otg_fsm *fsm)
 			otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
 		break;
 	case OTG_STATE_A_HOST:
-		if ((!fsm->a_bus_req || fsm->a_suspend_req_inf) &&
+		if (fsm->id || fsm->a_bus_drop)
+			otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
+		else if ((!fsm->a_bus_req || fsm->a_suspend_req_inf) &&
 				fsm->otg->host->b_hnp_enable)
 			otg_set_state(fsm, OTG_STATE_A_SUSPEND);
-		else if (fsm->id || !fsm->b_conn || fsm->a_bus_drop)
+		else if (!fsm->b_conn)
 			otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
 		else if (!fsm->a_vbus_vld)
 			otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
@@ -346,8 +348,7 @@ int otg_statemachine(struct otg_fsm *fsm)
 			otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
 		break;
 	case OTG_STATE_A_WAIT_VFALL:
-		if (fsm->a_wait_vfall_tmout || fsm->id || fsm->a_bus_req ||
-				(!fsm->a_sess_vld && !fsm->b_conn))
+		if (fsm->a_wait_vfall_tmout)
 			otg_set_state(fsm, OTG_STATE_A_IDLE);
 		break;
 	case OTG_STATE_A_VBUS_ERR: