drivers/usb/common/usb-otg-fsm.c - kernel/bruno - Git at Google

 /*
  * OTG Finite State Machine from OTG spec
  *
  * Copyright (C) 2007,2008 Freescale Semiconductor, Inc.
  *
  * Author:	Li Yang <LeoLi@freescale.com>
  *		Jerry Huang <Chang-Ming.Huang@freescale.com>
  *
  * This program is free software; you can redistribute  it and/or modify it
  * under  the terms of  the GNU General  Public License as published by the
  * Free Software Foundation;  either version 2 of the  License, or (at your
  * option) any later version.
  *
  * This program is distributed in the hope that it will be useful, but
  * WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * General Public License for more details.
  *
  * You should have received a copy of the  GNU General Public License along
  * with this program; if not, write  to the Free Software Foundation, Inc.,
  * 675 Mass Ave, Cambridge, MA 02139, USA.
  */

 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/types.h>
 #include <linux/mutex.h>
 #include <linux/delay.h>
 #include <linux/usb.h>
 #include <linux/usb/gadget.h>
 #include <linux/usb/otg.h>
 #include <linux/usb/otg-fsm.h>

 /* Change USB protocol when there is a protocol change */
 static int otg_set_protocol(struct otg_fsm *fsm, int protocol)
 {
 	int ret = 0;

 	if (fsm->protocol != protocol) {
 		VDBG("Changing role fsm->protocol= %d; new protocol= %d\n",
 			fsm->protocol, protocol);
 		/* stop old protocol */
 		if (fsm->protocol == PROTO_HOST)
 			ret = otg_start_host(fsm, 0);
 		else if (fsm->protocol == PROTO_GADGET)
 			ret = otg_start_gadget(fsm, 0);
 		if (ret)
 			return ret;

 		/* start new protocol */
 		if (protocol == PROTO_HOST)
 			ret = otg_start_host(fsm, 1);
 		else if (protocol == PROTO_GADGET)
 			ret = otg_start_gadget(fsm, 1);
 		if (ret)
 			return ret;

 		fsm->protocol = protocol;
 		return 0;
 	}

 	return 0;
 }

 static int state_changed;

 /* Called when leaving a state.  Do state clean up jobs here */
 static void otg_leave_state(struct otg_fsm *fsm, enum usb_otg_state old_state)
 {
 	switch (old_state) {
 	case OTG_STATE_B_IDLE:
 		otg_del_timer(fsm, B_SE0_SRP);
 		fsm->b_se0_srp = 0;
 		fsm->adp_sns = 0;
 		fsm->adp_prb = 0;
 		break;
 	case OTG_STATE_B_SRP_INIT:
 		fsm->data_pulse = 0;
 		fsm->b_srp_done = 0;
 		break;
 	case OTG_STATE_B_PERIPHERAL:
 		break;
 	case OTG_STATE_B_WAIT_ACON:
 		otg_del_timer(fsm, B_ASE0_BRST);
 		fsm->b_ase0_brst_tmout = 0;
 		break;
 	case OTG_STATE_B_HOST:
 		break;
 	case OTG_STATE_A_IDLE:
 		fsm->adp_prb = 0;
 		break;
 	case OTG_STATE_A_WAIT_VRISE:
 		otg_del_timer(fsm, A_WAIT_VRISE);
 		fsm->a_wait_vrise_tmout = 0;
 		break;
 	case OTG_STATE_A_WAIT_BCON:
 		otg_del_timer(fsm, A_WAIT_BCON);
 		fsm->a_wait_bcon_tmout = 0;
 		break;
 	case OTG_STATE_A_HOST:
 		otg_del_timer(fsm, A_WAIT_ENUM);
 		break;
 	case OTG_STATE_A_SUSPEND:
 		otg_del_timer(fsm, A_AIDL_BDIS);
 		fsm->a_aidl_bdis_tmout = 0;
 		fsm->a_suspend_req_inf = 0;
 		break;
 	case OTG_STATE_A_PERIPHERAL:
 		otg_del_timer(fsm, A_BIDL_ADIS);
 		fsm->a_bidl_adis_tmout = 0;
 		break;
 	case OTG_STATE_A_WAIT_VFALL:
 		otg_del_timer(fsm, A_WAIT_VFALL);
 		fsm->a_wait_vfall_tmout = 0;
 		otg_del_timer(fsm, A_WAIT_VRISE);
 		break;
 	case OTG_STATE_A_VBUS_ERR:
 		break;
 	default:
 		break;
 	}
 }

 /* Called when entering a state */
 static int otg_set_state(struct otg_fsm *fsm, enum usb_otg_state new_state)
 {
 	state_changed = 1;
 	if (fsm->otg->state == new_state)
 		return 0;
 	VDBG("Set state: %s\n", usb_otg_state_string(new_state));
 	otg_leave_state(fsm, fsm->otg->state);
 	switch (new_state) {
 	case OTG_STATE_B_IDLE:
 		otg_drv_vbus(fsm, 0);
 		otg_chrg_vbus(fsm, 0);
 		otg_loc_conn(fsm, 0);
 		otg_loc_sof(fsm, 0);
 		/*
 		 * Driver is responsible for starting ADP probing
 		 * if ADP sensing times out.
 		 */
 		otg_start_adp_sns(fsm);
 		otg_set_protocol(fsm, PROTO_UNDEF);
 		otg_add_timer(fsm, B_SE0_SRP);
 		break;
 	case OTG_STATE_B_SRP_INIT:
 		otg_start_pulse(fsm);
 		otg_loc_sof(fsm, 0);
 		otg_set_protocol(fsm, PROTO_UNDEF);
 		otg_add_timer(fsm, B_SRP_FAIL);
 		break;
 	case OTG_STATE_B_PERIPHERAL:
 		otg_chrg_vbus(fsm, 0);
 		otg_loc_sof(fsm, 0);
 		otg_set_protocol(fsm, PROTO_GADGET);
 		otg_loc_conn(fsm, 1);
 		break;
 	case OTG_STATE_B_WAIT_ACON:
 		otg_chrg_vbus(fsm, 0);
 		otg_loc_conn(fsm, 0);
 		otg_loc_sof(fsm, 0);
 		otg_set_protocol(fsm, PROTO_HOST);
 		otg_add_timer(fsm, B_ASE0_BRST);
 		fsm->a_bus_suspend = 0;
 		break;
 	case OTG_STATE_B_HOST:
 		otg_chrg_vbus(fsm, 0);
 		otg_loc_conn(fsm, 0);
 		otg_loc_sof(fsm, 1);
 		otg_set_protocol(fsm, PROTO_HOST);
 		usb_bus_start_enum(fsm->otg->host,
 				fsm->otg->host->otg_port);
 		break;
 	case OTG_STATE_A_IDLE:
 		otg_drv_vbus(fsm, 0);
 		otg_chrg_vbus(fsm, 0);
 		otg_loc_conn(fsm, 0);
 		otg_loc_sof(fsm, 0);
 		otg_start_adp_prb(fsm);
 		otg_set_protocol(fsm, PROTO_HOST);
 		break;
 	case OTG_STATE_A_WAIT_VRISE:
 		otg_drv_vbus(fsm, 1);
 		otg_loc_conn(fsm, 0);
 		otg_loc_sof(fsm, 0);
 		otg_set_protocol(fsm, PROTO_HOST);
 		otg_add_timer(fsm, A_WAIT_VRISE);
 		break;
 	case OTG_STATE_A_WAIT_BCON:
 		otg_drv_vbus(fsm, 1);
 		otg_loc_conn(fsm, 0);
 		otg_loc_sof(fsm, 0);
 		otg_set_protocol(fsm, PROTO_HOST);
 		otg_add_timer(fsm, A_WAIT_BCON);
 		break;
 	case OTG_STATE_A_HOST:
 		otg_drv_vbus(fsm, 1);
 		otg_loc_conn(fsm, 0);
 		otg_loc_sof(fsm, 1);
 		otg_set_protocol(fsm, PROTO_HOST);
 		/*
 		 * When HNP is triggered while a_bus_req = 0, a_host will
 		 * suspend too fast to complete a_set_b_hnp_en
 		 */
 		if (!fsm->a_bus_req || fsm->a_suspend_req_inf)
 			otg_add_timer(fsm, A_WAIT_ENUM);
 		break;
 	case OTG_STATE_A_SUSPEND:
 		otg_drv_vbus(fsm, 1);
 		otg_loc_conn(fsm, 0);
 		otg_loc_sof(fsm, 0);
 		otg_set_protocol(fsm, PROTO_HOST);
 		otg_add_timer(fsm, A_AIDL_BDIS);

 		break;
 	case OTG_STATE_A_PERIPHERAL:
 		otg_loc_sof(fsm, 0);
 		otg_set_protocol(fsm, PROTO_GADGET);
 		otg_drv_vbus(fsm, 1);
 		otg_loc_conn(fsm, 1);
 		otg_add_timer(fsm, A_BIDL_ADIS);
 		break;
 	case OTG_STATE_A_WAIT_VFALL:
 		otg_drv_vbus(fsm, 0);
 		otg_loc_conn(fsm, 0);
 		otg_loc_sof(fsm, 0);
 		otg_set_protocol(fsm, PROTO_HOST);
 		otg_add_timer(fsm, A_WAIT_VFALL);
 		break;
 	case OTG_STATE_A_VBUS_ERR:
 		otg_drv_vbus(fsm, 0);
 		otg_loc_conn(fsm, 0);
 		otg_loc_sof(fsm, 0);
 		otg_set_protocol(fsm, PROTO_UNDEF);
 		break;
 	default:
 		break;
 	}

 	fsm->otg->state = new_state;
 	return 0;
 }

 /* State change judgement */
 int otg_statemachine(struct otg_fsm *fsm)
 {
 	enum usb_otg_state state;

 	mutex_lock(&fsm->lock);

 	state = fsm->otg->state;
 	state_changed = 0;
 	/* State machine state change judgement */

 	switch (state) {
 	case OTG_STATE_UNDEFINED:
 		VDBG("fsm->id = %d\n", fsm->id);
 		if (fsm->id)
 			otg_set_state(fsm, OTG_STATE_B_IDLE);
 		else
 			otg_set_state(fsm, OTG_STATE_A_IDLE);
 		break;
 	case OTG_STATE_B_IDLE:
 		if (!fsm->id)
 			otg_set_state(fsm, OTG_STATE_A_IDLE);
 		else if (fsm->b_sess_vld && fsm->otg->gadget)
 			otg_set_state(fsm, OTG_STATE_B_PERIPHERAL);
 		else if ((fsm->b_bus_req || fsm->adp_change || fsm->power_up) &&
 				fsm->b_ssend_srp && fsm->b_se0_srp)
 			otg_set_state(fsm, OTG_STATE_B_SRP_INIT);
 		break;
 	case OTG_STATE_B_SRP_INIT:
 		if (!fsm->id || fsm->b_srp_done)
 			otg_set_state(fsm, OTG_STATE_B_IDLE);
 		break;
 	case OTG_STATE_B_PERIPHERAL:
 		if (!fsm->id || !fsm->b_sess_vld)
 			otg_set_state(fsm, OTG_STATE_B_IDLE);
 		else if (fsm->b_bus_req && fsm->otg->
 				gadget->b_hnp_enable && fsm->a_bus_suspend)
 			otg_set_state(fsm, OTG_STATE_B_WAIT_ACON);
 		break;
 	case OTG_STATE_B_WAIT_ACON:
 		if (fsm->a_conn)
 			otg_set_state(fsm, OTG_STATE_B_HOST);
 		else if (!fsm->id || !fsm->b_sess_vld)
 			otg_set_state(fsm, OTG_STATE_B_IDLE);
 		else if (fsm->a_bus_resume || fsm->b_ase0_brst_tmout) {
 			fsm->b_ase0_brst_tmout = 0;
 			otg_set_state(fsm, OTG_STATE_B_PERIPHERAL);
 		}
 		break;
 	case OTG_STATE_B_HOST:
 		if (!fsm->id || !fsm->b_sess_vld)
 			otg_set_state(fsm, OTG_STATE_B_IDLE);
 		else if (!fsm->b_bus_req || !fsm->a_conn || fsm->test_device)
 			otg_set_state(fsm, OTG_STATE_B_PERIPHERAL);
 		break;
 	case OTG_STATE_A_IDLE:
 		if (fsm->id)
 			otg_set_state(fsm, OTG_STATE_B_IDLE);
 		else if (!fsm->a_bus_drop && (fsm->a_bus_req ||
 			  fsm->a_srp_det || fsm->adp_change || fsm->power_up))
 			otg_set_state(fsm, OTG_STATE_A_WAIT_VRISE);
 		break;
 	case OTG_STATE_A_WAIT_VRISE:
 		if (fsm->a_vbus_vld)
 			otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
 		else if (fsm->id || fsm->a_bus_drop ||
 				fsm->a_wait_vrise_tmout)
 			otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
 		break;
 	case OTG_STATE_A_WAIT_BCON:
 		if (!fsm->a_vbus_vld)
 			otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
 		else if (fsm->b_conn)
 			otg_set_state(fsm, OTG_STATE_A_HOST);
 		else if (fsm->id || fsm->a_bus_drop || fsm->a_wait_bcon_tmout)
 			otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
 		break;
 	case OTG_STATE_A_HOST:
 		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->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);
 		break;
 	case OTG_STATE_A_SUSPEND:
 		if (!fsm->b_conn && fsm->otg->host->b_hnp_enable)
 			otg_set_state(fsm, OTG_STATE_A_PERIPHERAL);
 		else if (!fsm->b_conn && !fsm->otg->host->b_hnp_enable)
 			otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
 		else if (fsm->a_bus_req || fsm->b_bus_resume)
 			otg_set_state(fsm, OTG_STATE_A_HOST);
 		else if (fsm->id || fsm->a_bus_drop || fsm->a_aidl_bdis_tmout)
 			otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
 		else if (!fsm->a_vbus_vld)
 			otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
 		break;
 	case OTG_STATE_A_PERIPHERAL:
 		if (fsm->id || fsm->a_bus_drop)
 			otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
 		else if (fsm->a_bidl_adis_tmout || fsm->b_bus_suspend)
 			otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
 		else if (!fsm->a_vbus_vld)
 			otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
 		break;
 	case OTG_STATE_A_WAIT_VFALL:
 		if (fsm->a_wait_vfall_tmout)
 			otg_set_state(fsm, OTG_STATE_A_IDLE);
 		break;
 	case OTG_STATE_A_VBUS_ERR:
 		if (fsm->id || fsm->a_bus_drop || fsm->a_clr_err)
 			otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
 		break;
 	default:
 		break;
 	}
 	mutex_unlock(&fsm->lock);

 	VDBG("quit statemachine, changed = %d\n", state_changed);
 	return state_changed;
 }
 EXPORT_SYMBOL_GPL(otg_statemachine);
 MODULE_LICENSE("GPL");
	/*
	* OTG Finite State Machine from OTG spec
	*
	* Copyright (C) 2007,2008 Freescale Semiconductor, Inc.
	*
	* Author: Li Yang <LeoLi@freescale.com>
	* Jerry Huang <Chang-Ming.Huang@freescale.com>
	*
	* This program is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License as published by the
	* Free Software Foundation; either version 2 of the License, or (at your
	* option) any later version.
	*
	* This program is distributed in the hope that it will be useful, but
	* WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License along
	* with this program; if not, write to the Free Software Foundation, Inc.,
	* 675 Mass Ave, Cambridge, MA 02139, USA.
	*/

	#include <linux/module.h>
	#include <linux/kernel.h>
	#include <linux/types.h>
	#include <linux/mutex.h>
	#include <linux/delay.h>
	#include <linux/usb.h>
	#include <linux/usb/gadget.h>
	#include <linux/usb/otg.h>
	#include <linux/usb/otg-fsm.h>

	/* Change USB protocol when there is a protocol change */
	static int otg_set_protocol(struct otg_fsm *fsm, int protocol)
	{
	int ret = 0;

	if (fsm->protocol != protocol) {
	VDBG("Changing role fsm->protocol= %d; new protocol= %d\n",
	fsm->protocol, protocol);
	/* stop old protocol */
	if (fsm->protocol == PROTO_HOST)
	ret = otg_start_host(fsm, 0);
	else if (fsm->protocol == PROTO_GADGET)
	ret = otg_start_gadget(fsm, 0);
	if (ret)
	return ret;

	/* start new protocol */
	if (protocol == PROTO_HOST)
	ret = otg_start_host(fsm, 1);
	else if (protocol == PROTO_GADGET)
	ret = otg_start_gadget(fsm, 1);
	if (ret)
	return ret;

	fsm->protocol = protocol;
	return 0;
	}

	return 0;
	}

	static int state_changed;

	/* Called when leaving a state. Do state clean up jobs here */
	static void otg_leave_state(struct otg_fsm *fsm, enum usb_otg_state old_state)
	{
	switch (old_state) {
	case OTG_STATE_B_IDLE:
	otg_del_timer(fsm, B_SE0_SRP);
	fsm->b_se0_srp = 0;
	fsm->adp_sns = 0;
	fsm->adp_prb = 0;
	break;
	case OTG_STATE_B_SRP_INIT:
	fsm->data_pulse = 0;
	fsm->b_srp_done = 0;
	break;
	case OTG_STATE_B_PERIPHERAL:
	break;
	case OTG_STATE_B_WAIT_ACON:
	otg_del_timer(fsm, B_ASE0_BRST);
	fsm->b_ase0_brst_tmout = 0;
	break;
	case OTG_STATE_B_HOST:
	break;
	case OTG_STATE_A_IDLE:
	fsm->adp_prb = 0;
	break;
	case OTG_STATE_A_WAIT_VRISE:
	otg_del_timer(fsm, A_WAIT_VRISE);
	fsm->a_wait_vrise_tmout = 0;
	break;
	case OTG_STATE_A_WAIT_BCON:
	otg_del_timer(fsm, A_WAIT_BCON);
	fsm->a_wait_bcon_tmout = 0;
	break;
	case OTG_STATE_A_HOST:
	otg_del_timer(fsm, A_WAIT_ENUM);
	break;
	case OTG_STATE_A_SUSPEND:
	otg_del_timer(fsm, A_AIDL_BDIS);
	fsm->a_aidl_bdis_tmout = 0;
	fsm->a_suspend_req_inf = 0;
	break;
	case OTG_STATE_A_PERIPHERAL:
	otg_del_timer(fsm, A_BIDL_ADIS);
	fsm->a_bidl_adis_tmout = 0;
	break;
	case OTG_STATE_A_WAIT_VFALL:
	otg_del_timer(fsm, A_WAIT_VFALL);
	fsm->a_wait_vfall_tmout = 0;
	otg_del_timer(fsm, A_WAIT_VRISE);
	break;
	case OTG_STATE_A_VBUS_ERR:
	break;
	default:
	break;
	}
	}

	/* Called when entering a state */
	static int otg_set_state(struct otg_fsm *fsm, enum usb_otg_state new_state)
	{
	state_changed = 1;
	if (fsm->otg->state == new_state)
	return 0;
	VDBG("Set state: %s\n", usb_otg_state_string(new_state));
	otg_leave_state(fsm, fsm->otg->state);
	switch (new_state) {
	case OTG_STATE_B_IDLE:
	otg_drv_vbus(fsm, 0);
	otg_chrg_vbus(fsm, 0);
	otg_loc_conn(fsm, 0);
	otg_loc_sof(fsm, 0);
	/*
	* Driver is responsible for starting ADP probing
	* if ADP sensing times out.
	*/
	otg_start_adp_sns(fsm);
	otg_set_protocol(fsm, PROTO_UNDEF);
	otg_add_timer(fsm, B_SE0_SRP);
	break;
	case OTG_STATE_B_SRP_INIT:
	otg_start_pulse(fsm);
	otg_loc_sof(fsm, 0);
	otg_set_protocol(fsm, PROTO_UNDEF);
	otg_add_timer(fsm, B_SRP_FAIL);
	break;
	case OTG_STATE_B_PERIPHERAL:
	otg_chrg_vbus(fsm, 0);
	otg_loc_sof(fsm, 0);
	otg_set_protocol(fsm, PROTO_GADGET);
	otg_loc_conn(fsm, 1);
	break;
	case OTG_STATE_B_WAIT_ACON:
	otg_chrg_vbus(fsm, 0);
	otg_loc_conn(fsm, 0);
	otg_loc_sof(fsm, 0);
	otg_set_protocol(fsm, PROTO_HOST);
	otg_add_timer(fsm, B_ASE0_BRST);
	fsm->a_bus_suspend = 0;
	break;
	case OTG_STATE_B_HOST:
	otg_chrg_vbus(fsm, 0);
	otg_loc_conn(fsm, 0);
	otg_loc_sof(fsm, 1);
	otg_set_protocol(fsm, PROTO_HOST);
	usb_bus_start_enum(fsm->otg->host,
	fsm->otg->host->otg_port);
	break;
	case OTG_STATE_A_IDLE:
	otg_drv_vbus(fsm, 0);
	otg_chrg_vbus(fsm, 0);
	otg_loc_conn(fsm, 0);
	otg_loc_sof(fsm, 0);
	otg_start_adp_prb(fsm);
	otg_set_protocol(fsm, PROTO_HOST);
	break;
	case OTG_STATE_A_WAIT_VRISE:
	otg_drv_vbus(fsm, 1);
	otg_loc_conn(fsm, 0);
	otg_loc_sof(fsm, 0);
	otg_set_protocol(fsm, PROTO_HOST);
	otg_add_timer(fsm, A_WAIT_VRISE);
	break;
	case OTG_STATE_A_WAIT_BCON:
	otg_drv_vbus(fsm, 1);
	otg_loc_conn(fsm, 0);
	otg_loc_sof(fsm, 0);
	otg_set_protocol(fsm, PROTO_HOST);
	otg_add_timer(fsm, A_WAIT_BCON);
	break;
	case OTG_STATE_A_HOST:
	otg_drv_vbus(fsm, 1);
	otg_loc_conn(fsm, 0);
	otg_loc_sof(fsm, 1);
	otg_set_protocol(fsm, PROTO_HOST);
	/*
	* When HNP is triggered while a_bus_req = 0, a_host will
	* suspend too fast to complete a_set_b_hnp_en
	*/
	if (!fsm->a_bus_req \|\| fsm->a_suspend_req_inf)
	otg_add_timer(fsm, A_WAIT_ENUM);
	break;
	case OTG_STATE_A_SUSPEND:
	otg_drv_vbus(fsm, 1);
	otg_loc_conn(fsm, 0);
	otg_loc_sof(fsm, 0);
	otg_set_protocol(fsm, PROTO_HOST);
	otg_add_timer(fsm, A_AIDL_BDIS);

	break;
	case OTG_STATE_A_PERIPHERAL:
	otg_loc_sof(fsm, 0);
	otg_set_protocol(fsm, PROTO_GADGET);
	otg_drv_vbus(fsm, 1);
	otg_loc_conn(fsm, 1);
	otg_add_timer(fsm, A_BIDL_ADIS);
	break;
	case OTG_STATE_A_WAIT_VFALL:
	otg_drv_vbus(fsm, 0);
	otg_loc_conn(fsm, 0);
	otg_loc_sof(fsm, 0);
	otg_set_protocol(fsm, PROTO_HOST);
	otg_add_timer(fsm, A_WAIT_VFALL);
	break;
	case OTG_STATE_A_VBUS_ERR:
	otg_drv_vbus(fsm, 0);
	otg_loc_conn(fsm, 0);
	otg_loc_sof(fsm, 0);
	otg_set_protocol(fsm, PROTO_UNDEF);
	break;
	default:
	break;
	}

	fsm->otg->state = new_state;
	return 0;
	}

	/* State change judgement */
	int otg_statemachine(struct otg_fsm *fsm)
	{
	enum usb_otg_state state;

	mutex_lock(&fsm->lock);

	state = fsm->otg->state;
	state_changed = 0;
	/* State machine state change judgement */

	switch (state) {
	case OTG_STATE_UNDEFINED:
	VDBG("fsm->id = %d\n", fsm->id);
	if (fsm->id)
	otg_set_state(fsm, OTG_STATE_B_IDLE);
	else
	otg_set_state(fsm, OTG_STATE_A_IDLE);
	break;
	case OTG_STATE_B_IDLE:
	if (!fsm->id)
	otg_set_state(fsm, OTG_STATE_A_IDLE);
	else if (fsm->b_sess_vld && fsm->otg->gadget)
	otg_set_state(fsm, OTG_STATE_B_PERIPHERAL);
	else if ((fsm->b_bus_req \|\| fsm->adp_change \|\| fsm->power_up) &&
	fsm->b_ssend_srp && fsm->b_se0_srp)
	otg_set_state(fsm, OTG_STATE_B_SRP_INIT);
	break;
	case OTG_STATE_B_SRP_INIT:
	if (!fsm->id \|\| fsm->b_srp_done)
	otg_set_state(fsm, OTG_STATE_B_IDLE);
	break;
	case OTG_STATE_B_PERIPHERAL:
	if (!fsm->id \|\| !fsm->b_sess_vld)
	otg_set_state(fsm, OTG_STATE_B_IDLE);
	else if (fsm->b_bus_req && fsm->otg->
	gadget->b_hnp_enable && fsm->a_bus_suspend)
	otg_set_state(fsm, OTG_STATE_B_WAIT_ACON);
	break;
	case OTG_STATE_B_WAIT_ACON:
	if (fsm->a_conn)
	otg_set_state(fsm, OTG_STATE_B_HOST);
	else if (!fsm->id \|\| !fsm->b_sess_vld)
	otg_set_state(fsm, OTG_STATE_B_IDLE);
	else if (fsm->a_bus_resume \|\| fsm->b_ase0_brst_tmout) {
	fsm->b_ase0_brst_tmout = 0;
	otg_set_state(fsm, OTG_STATE_B_PERIPHERAL);
	}
	break;
	case OTG_STATE_B_HOST:
	if (!fsm->id \|\| !fsm->b_sess_vld)
	otg_set_state(fsm, OTG_STATE_B_IDLE);
	else if (!fsm->b_bus_req \|\| !fsm->a_conn \|\| fsm->test_device)
	otg_set_state(fsm, OTG_STATE_B_PERIPHERAL);
	break;
	case OTG_STATE_A_IDLE:
	if (fsm->id)
	otg_set_state(fsm, OTG_STATE_B_IDLE);
	else if (!fsm->a_bus_drop && (fsm->a_bus_req \|\|
	fsm->a_srp_det \|\| fsm->adp_change \|\| fsm->power_up))
	otg_set_state(fsm, OTG_STATE_A_WAIT_VRISE);
	break;
	case OTG_STATE_A_WAIT_VRISE:
	if (fsm->a_vbus_vld)
	otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
	else if (fsm->id \|\| fsm->a_bus_drop \|\|
	fsm->a_wait_vrise_tmout)
	otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
	break;
	case OTG_STATE_A_WAIT_BCON:
	if (!fsm->a_vbus_vld)
	otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
	else if (fsm->b_conn)
	otg_set_state(fsm, OTG_STATE_A_HOST);
	else if (fsm->id \|\| fsm->a_bus_drop \|\| fsm->a_wait_bcon_tmout)
	otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
	break;
	case OTG_STATE_A_HOST:
	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->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);
	break;
	case OTG_STATE_A_SUSPEND:
	if (!fsm->b_conn && fsm->otg->host->b_hnp_enable)
	otg_set_state(fsm, OTG_STATE_A_PERIPHERAL);
	else if (!fsm->b_conn && !fsm->otg->host->b_hnp_enable)
	otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
	else if (fsm->a_bus_req \|\| fsm->b_bus_resume)
	otg_set_state(fsm, OTG_STATE_A_HOST);
	else if (fsm->id \|\| fsm->a_bus_drop \|\| fsm->a_aidl_bdis_tmout)
	otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
	else if (!fsm->a_vbus_vld)
	otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
	break;
	case OTG_STATE_A_PERIPHERAL:
	if (fsm->id \|\| fsm->a_bus_drop)
	otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
	else if (fsm->a_bidl_adis_tmout \|\| fsm->b_bus_suspend)
	otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
	else if (!fsm->a_vbus_vld)
	otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
	break;
	case OTG_STATE_A_WAIT_VFALL:
	if (fsm->a_wait_vfall_tmout)
	otg_set_state(fsm, OTG_STATE_A_IDLE);
	break;
	case OTG_STATE_A_VBUS_ERR:
	if (fsm->id \|\| fsm->a_bus_drop \|\| fsm->a_clr_err)
	otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
	break;
	default:
	break;
	}
	mutex_unlock(&fsm->lock);

	VDBG("quit statemachine, changed = %d\n", state_changed);
	return state_changed;
	}
	EXPORT_SYMBOL_GPL(otg_statemachine);
	MODULE_LICENSE("GPL");