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v6.8
  1// SPDX-License-Identifier: GPL-2.0+
  2/*
  3 * OTG Finite State Machine from OTG spec
  4 *
  5 * Copyright (C) 2007,2008 Freescale Semiconductor, Inc.
  6 *
  7 * Author:	Li Yang <LeoLi@freescale.com>
  8 *		Jerry Huang <Chang-Ming.Huang@freescale.com>
  9 */
 10
 11#include <linux/module.h>
 12#include <linux/kernel.h>
 13#include <linux/types.h>
 14#include <linux/mutex.h>
 15#include <linux/delay.h>
 16#include <linux/usb.h>
 17#include <linux/usb/gadget.h>
 18#include <linux/usb/otg.h>
 19#include <linux/usb/otg-fsm.h>
 20
 21#ifdef VERBOSE
 22#define VDBG(fmt, args...) pr_debug("[%s]  " fmt, \
 23				 __func__, ## args)
 24#else
 25#define VDBG(stuff...)	do {} while (0)
 26#endif
 27
 28/* Change USB protocol when there is a protocol change */
 29static int otg_set_protocol(struct otg_fsm *fsm, int protocol)
 30{
 31	int ret = 0;
 32
 33	if (fsm->protocol != protocol) {
 34		VDBG("Changing role fsm->protocol= %d; new protocol= %d\n",
 35			fsm->protocol, protocol);
 36		/* stop old protocol */
 37		if (fsm->protocol == PROTO_HOST)
 38			ret = otg_start_host(fsm, 0);
 39		else if (fsm->protocol == PROTO_GADGET)
 40			ret = otg_start_gadget(fsm, 0);
 41		if (ret)
 42			return ret;
 43
 44		/* start new protocol */
 45		if (protocol == PROTO_HOST)
 46			ret = otg_start_host(fsm, 1);
 47		else if (protocol == PROTO_GADGET)
 48			ret = otg_start_gadget(fsm, 1);
 49		if (ret)
 50			return ret;
 51
 52		fsm->protocol = protocol;
 53		return 0;
 54	}
 55
 56	return 0;
 57}
 58
 59/* Called when leaving a state.  Do state clean up jobs here */
 60static void otg_leave_state(struct otg_fsm *fsm, enum usb_otg_state old_state)
 61{
 62	switch (old_state) {
 63	case OTG_STATE_B_IDLE:
 64		otg_del_timer(fsm, B_SE0_SRP);
 65		fsm->b_se0_srp = 0;
 66		fsm->adp_sns = 0;
 67		fsm->adp_prb = 0;
 68		break;
 69	case OTG_STATE_B_SRP_INIT:
 70		fsm->data_pulse = 0;
 71		fsm->b_srp_done = 0;
 72		break;
 73	case OTG_STATE_B_PERIPHERAL:
 74		if (fsm->otg->gadget)
 75			fsm->otg->gadget->host_request_flag = 0;
 76		break;
 77	case OTG_STATE_B_WAIT_ACON:
 78		otg_del_timer(fsm, B_ASE0_BRST);
 79		fsm->b_ase0_brst_tmout = 0;
 80		break;
 81	case OTG_STATE_B_HOST:
 82		break;
 83	case OTG_STATE_A_IDLE:
 84		fsm->adp_prb = 0;
 85		break;
 86	case OTG_STATE_A_WAIT_VRISE:
 87		otg_del_timer(fsm, A_WAIT_VRISE);
 88		fsm->a_wait_vrise_tmout = 0;
 89		break;
 90	case OTG_STATE_A_WAIT_BCON:
 91		otg_del_timer(fsm, A_WAIT_BCON);
 92		fsm->a_wait_bcon_tmout = 0;
 93		break;
 94	case OTG_STATE_A_HOST:
 95		otg_del_timer(fsm, A_WAIT_ENUM);
 96		break;
 97	case OTG_STATE_A_SUSPEND:
 98		otg_del_timer(fsm, A_AIDL_BDIS);
 99		fsm->a_aidl_bdis_tmout = 0;
100		fsm->a_suspend_req_inf = 0;
101		break;
102	case OTG_STATE_A_PERIPHERAL:
103		otg_del_timer(fsm, A_BIDL_ADIS);
104		fsm->a_bidl_adis_tmout = 0;
105		if (fsm->otg->gadget)
106			fsm->otg->gadget->host_request_flag = 0;
107		break;
108	case OTG_STATE_A_WAIT_VFALL:
109		otg_del_timer(fsm, A_WAIT_VFALL);
110		fsm->a_wait_vfall_tmout = 0;
111		otg_del_timer(fsm, A_WAIT_VRISE);
112		break;
113	case OTG_STATE_A_VBUS_ERR:
114		break;
115	default:
116		break;
117	}
118}
119
120static void otg_hnp_polling_work(struct work_struct *work)
121{
122	struct otg_fsm *fsm = container_of(to_delayed_work(work),
123				struct otg_fsm, hnp_polling_work);
124	struct usb_device *udev;
125	enum usb_otg_state state = fsm->otg->state;
126	u8 flag;
127	int retval;
128
129	if (state != OTG_STATE_A_HOST && state != OTG_STATE_B_HOST)
130		return;
131
132	udev = usb_hub_find_child(fsm->otg->host->root_hub, 1);
133	if (!udev) {
134		dev_err(fsm->otg->host->controller,
135			"no usb dev connected, can't start HNP polling\n");
136		return;
137	}
138
139	*fsm->host_req_flag = 0;
140	/* Get host request flag from connected USB device */
141	retval = usb_control_msg(udev,
142				usb_rcvctrlpipe(udev, 0),
143				USB_REQ_GET_STATUS,
144				USB_DIR_IN | USB_RECIP_DEVICE,
145				0,
146				OTG_STS_SELECTOR,
147				fsm->host_req_flag,
148				1,
149				USB_CTRL_GET_TIMEOUT);
150	if (retval != 1) {
151		dev_err(&udev->dev, "Get one byte OTG status failed\n");
152		return;
153	}
154
155	flag = *fsm->host_req_flag;
156	if (flag == 0) {
157		/* Continue HNP polling */
158		schedule_delayed_work(&fsm->hnp_polling_work,
159					msecs_to_jiffies(T_HOST_REQ_POLL));
160		return;
161	} else if (flag != HOST_REQUEST_FLAG) {
162		dev_err(&udev->dev, "host request flag %d is invalid\n", flag);
163		return;
164	}
165
166	/* Host request flag is set */
167	if (state == OTG_STATE_A_HOST) {
168		/* Set b_hnp_enable */
169		if (!fsm->otg->host->b_hnp_enable) {
170			retval = usb_control_msg(udev,
171					usb_sndctrlpipe(udev, 0),
172					USB_REQ_SET_FEATURE, 0,
173					USB_DEVICE_B_HNP_ENABLE,
174					0, NULL, 0,
175					USB_CTRL_SET_TIMEOUT);
176			if (retval >= 0)
177				fsm->otg->host->b_hnp_enable = 1;
178		}
179		fsm->a_bus_req = 0;
180	} else if (state == OTG_STATE_B_HOST) {
181		fsm->b_bus_req = 0;
182	}
183
184	otg_statemachine(fsm);
185}
186
187static void otg_start_hnp_polling(struct otg_fsm *fsm)
188{
189	/*
190	 * The memory of host_req_flag should be allocated by
191	 * controller driver, otherwise, hnp polling is not started.
192	 */
193	if (!fsm->host_req_flag)
194		return;
195
196	if (!fsm->hnp_work_inited) {
197		INIT_DELAYED_WORK(&fsm->hnp_polling_work, otg_hnp_polling_work);
198		fsm->hnp_work_inited = true;
199	}
200
201	schedule_delayed_work(&fsm->hnp_polling_work,
202					msecs_to_jiffies(T_HOST_REQ_POLL));
203}
204
205/* Called when entering a state */
206static int otg_set_state(struct otg_fsm *fsm, enum usb_otg_state new_state)
207{
208	if (fsm->otg->state == new_state)
209		return 0;
210	VDBG("Set state: %s\n", usb_otg_state_string(new_state));
211	otg_leave_state(fsm, fsm->otg->state);
212	switch (new_state) {
213	case OTG_STATE_B_IDLE:
214		otg_drv_vbus(fsm, 0);
215		otg_chrg_vbus(fsm, 0);
216		otg_loc_conn(fsm, 0);
217		otg_loc_sof(fsm, 0);
218		/*
219		 * Driver is responsible for starting ADP probing
220		 * if ADP sensing times out.
221		 */
222		otg_start_adp_sns(fsm);
223		otg_set_protocol(fsm, PROTO_UNDEF);
224		otg_add_timer(fsm, B_SE0_SRP);
225		break;
226	case OTG_STATE_B_SRP_INIT:
227		otg_start_pulse(fsm);
228		otg_loc_sof(fsm, 0);
229		otg_set_protocol(fsm, PROTO_UNDEF);
230		otg_add_timer(fsm, B_SRP_FAIL);
231		break;
232	case OTG_STATE_B_PERIPHERAL:
233		otg_chrg_vbus(fsm, 0);
234		otg_loc_sof(fsm, 0);
235		otg_set_protocol(fsm, PROTO_GADGET);
236		otg_loc_conn(fsm, 1);
237		break;
238	case OTG_STATE_B_WAIT_ACON:
239		otg_chrg_vbus(fsm, 0);
240		otg_loc_conn(fsm, 0);
241		otg_loc_sof(fsm, 0);
242		otg_set_protocol(fsm, PROTO_HOST);
243		otg_add_timer(fsm, B_ASE0_BRST);
244		fsm->a_bus_suspend = 0;
245		break;
246	case OTG_STATE_B_HOST:
247		otg_chrg_vbus(fsm, 0);
248		otg_loc_conn(fsm, 0);
249		otg_loc_sof(fsm, 1);
250		otg_set_protocol(fsm, PROTO_HOST);
251		usb_bus_start_enum(fsm->otg->host,
252				fsm->otg->host->otg_port);
253		otg_start_hnp_polling(fsm);
254		break;
255	case OTG_STATE_A_IDLE:
256		otg_drv_vbus(fsm, 0);
257		otg_chrg_vbus(fsm, 0);
258		otg_loc_conn(fsm, 0);
259		otg_loc_sof(fsm, 0);
260		otg_start_adp_prb(fsm);
261		otg_set_protocol(fsm, PROTO_HOST);
262		break;
263	case OTG_STATE_A_WAIT_VRISE:
264		otg_drv_vbus(fsm, 1);
265		otg_loc_conn(fsm, 0);
266		otg_loc_sof(fsm, 0);
267		otg_set_protocol(fsm, PROTO_HOST);
268		otg_add_timer(fsm, A_WAIT_VRISE);
269		break;
270	case OTG_STATE_A_WAIT_BCON:
271		otg_drv_vbus(fsm, 1);
272		otg_loc_conn(fsm, 0);
273		otg_loc_sof(fsm, 0);
274		otg_set_protocol(fsm, PROTO_HOST);
275		otg_add_timer(fsm, A_WAIT_BCON);
276		break;
277	case OTG_STATE_A_HOST:
278		otg_drv_vbus(fsm, 1);
279		otg_loc_conn(fsm, 0);
280		otg_loc_sof(fsm, 1);
281		otg_set_protocol(fsm, PROTO_HOST);
282		/*
283		 * When HNP is triggered while a_bus_req = 0, a_host will
284		 * suspend too fast to complete a_set_b_hnp_en
285		 */
286		if (!fsm->a_bus_req || fsm->a_suspend_req_inf)
287			otg_add_timer(fsm, A_WAIT_ENUM);
288		otg_start_hnp_polling(fsm);
289		break;
290	case OTG_STATE_A_SUSPEND:
291		otg_drv_vbus(fsm, 1);
292		otg_loc_conn(fsm, 0);
293		otg_loc_sof(fsm, 0);
294		otg_set_protocol(fsm, PROTO_HOST);
295		otg_add_timer(fsm, A_AIDL_BDIS);
296
297		break;
298	case OTG_STATE_A_PERIPHERAL:
299		otg_loc_sof(fsm, 0);
300		otg_set_protocol(fsm, PROTO_GADGET);
301		otg_drv_vbus(fsm, 1);
302		otg_loc_conn(fsm, 1);
303		otg_add_timer(fsm, A_BIDL_ADIS);
304		break;
305	case OTG_STATE_A_WAIT_VFALL:
306		otg_drv_vbus(fsm, 0);
307		otg_loc_conn(fsm, 0);
308		otg_loc_sof(fsm, 0);
309		otg_set_protocol(fsm, PROTO_HOST);
310		otg_add_timer(fsm, A_WAIT_VFALL);
311		break;
312	case OTG_STATE_A_VBUS_ERR:
313		otg_drv_vbus(fsm, 0);
314		otg_loc_conn(fsm, 0);
315		otg_loc_sof(fsm, 0);
316		otg_set_protocol(fsm, PROTO_UNDEF);
317		break;
318	default:
319		break;
320	}
321
322	fsm->otg->state = new_state;
323	fsm->state_changed = 1;
324	return 0;
325}
326
327/* State change judgement */
328int otg_statemachine(struct otg_fsm *fsm)
329{
330	enum usb_otg_state state;
331
332	mutex_lock(&fsm->lock);
333
334	state = fsm->otg->state;
335	fsm->state_changed = 0;
336	/* State machine state change judgement */
337
338	switch (state) {
339	case OTG_STATE_UNDEFINED:
340		VDBG("fsm->id = %d\n", fsm->id);
341		if (fsm->id)
342			otg_set_state(fsm, OTG_STATE_B_IDLE);
343		else
344			otg_set_state(fsm, OTG_STATE_A_IDLE);
345		break;
346	case OTG_STATE_B_IDLE:
347		if (!fsm->id)
348			otg_set_state(fsm, OTG_STATE_A_IDLE);
349		else if (fsm->b_sess_vld && fsm->otg->gadget)
350			otg_set_state(fsm, OTG_STATE_B_PERIPHERAL);
351		else if ((fsm->b_bus_req || fsm->adp_change || fsm->power_up) &&
352				fsm->b_ssend_srp && fsm->b_se0_srp)
353			otg_set_state(fsm, OTG_STATE_B_SRP_INIT);
354		break;
355	case OTG_STATE_B_SRP_INIT:
356		if (!fsm->id || fsm->b_srp_done)
357			otg_set_state(fsm, OTG_STATE_B_IDLE);
358		break;
359	case OTG_STATE_B_PERIPHERAL:
360		if (!fsm->id || !fsm->b_sess_vld)
361			otg_set_state(fsm, OTG_STATE_B_IDLE);
362		else if (fsm->b_bus_req && fsm->otg->
363				gadget->b_hnp_enable && fsm->a_bus_suspend)
364			otg_set_state(fsm, OTG_STATE_B_WAIT_ACON);
365		break;
366	case OTG_STATE_B_WAIT_ACON:
367		if (fsm->a_conn)
368			otg_set_state(fsm, OTG_STATE_B_HOST);
369		else if (!fsm->id || !fsm->b_sess_vld)
370			otg_set_state(fsm, OTG_STATE_B_IDLE);
371		else if (fsm->a_bus_resume || fsm->b_ase0_brst_tmout) {
372			fsm->b_ase0_brst_tmout = 0;
373			otg_set_state(fsm, OTG_STATE_B_PERIPHERAL);
374		}
375		break;
376	case OTG_STATE_B_HOST:
377		if (!fsm->id || !fsm->b_sess_vld)
378			otg_set_state(fsm, OTG_STATE_B_IDLE);
379		else if (!fsm->b_bus_req || !fsm->a_conn || fsm->test_device)
380			otg_set_state(fsm, OTG_STATE_B_PERIPHERAL);
381		break;
382	case OTG_STATE_A_IDLE:
383		if (fsm->id)
384			otg_set_state(fsm, OTG_STATE_B_IDLE);
385		else if (!fsm->a_bus_drop && (fsm->a_bus_req ||
386			  fsm->a_srp_det || fsm->adp_change || fsm->power_up))
387			otg_set_state(fsm, OTG_STATE_A_WAIT_VRISE);
388		break;
389	case OTG_STATE_A_WAIT_VRISE:
390		if (fsm->a_vbus_vld)
391			otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
392		else if (fsm->id || fsm->a_bus_drop ||
393				fsm->a_wait_vrise_tmout)
394			otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
395		break;
396	case OTG_STATE_A_WAIT_BCON:
397		if (!fsm->a_vbus_vld)
398			otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
399		else if (fsm->b_conn)
400			otg_set_state(fsm, OTG_STATE_A_HOST);
401		else if (fsm->id || fsm->a_bus_drop || fsm->a_wait_bcon_tmout)
402			otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
403		break;
404	case OTG_STATE_A_HOST:
405		if (fsm->id || fsm->a_bus_drop)
406			otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
407		else if ((!fsm->a_bus_req || fsm->a_suspend_req_inf) &&
408				fsm->otg->host->b_hnp_enable)
409			otg_set_state(fsm, OTG_STATE_A_SUSPEND);
410		else if (!fsm->b_conn)
411			otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
412		else if (!fsm->a_vbus_vld)
413			otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
414		break;
415	case OTG_STATE_A_SUSPEND:
416		if (!fsm->b_conn && fsm->otg->host->b_hnp_enable)
417			otg_set_state(fsm, OTG_STATE_A_PERIPHERAL);
418		else if (!fsm->b_conn && !fsm->otg->host->b_hnp_enable)
419			otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
420		else if (fsm->a_bus_req || fsm->b_bus_resume)
421			otg_set_state(fsm, OTG_STATE_A_HOST);
422		else if (fsm->id || fsm->a_bus_drop || fsm->a_aidl_bdis_tmout)
423			otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
424		else if (!fsm->a_vbus_vld)
425			otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
426		break;
427	case OTG_STATE_A_PERIPHERAL:
428		if (fsm->id || fsm->a_bus_drop)
429			otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
430		else if (fsm->a_bidl_adis_tmout || fsm->b_bus_suspend)
431			otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
432		else if (!fsm->a_vbus_vld)
433			otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
434		break;
435	case OTG_STATE_A_WAIT_VFALL:
436		if (fsm->a_wait_vfall_tmout)
437			otg_set_state(fsm, OTG_STATE_A_IDLE);
438		break;
439	case OTG_STATE_A_VBUS_ERR:
440		if (fsm->id || fsm->a_bus_drop || fsm->a_clr_err)
441			otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
442		break;
443	default:
444		break;
445	}
446	mutex_unlock(&fsm->lock);
447
448	VDBG("quit statemachine, changed = %d\n", fsm->state_changed);
449	return fsm->state_changed;
450}
451EXPORT_SYMBOL_GPL(otg_statemachine);
452MODULE_LICENSE("GPL");
v6.2
  1// SPDX-License-Identifier: GPL-2.0+
  2/*
  3 * OTG Finite State Machine from OTG spec
  4 *
  5 * Copyright (C) 2007,2008 Freescale Semiconductor, Inc.
  6 *
  7 * Author:	Li Yang <LeoLi@freescale.com>
  8 *		Jerry Huang <Chang-Ming.Huang@freescale.com>
  9 */
 10
 11#include <linux/module.h>
 12#include <linux/kernel.h>
 13#include <linux/types.h>
 14#include <linux/mutex.h>
 15#include <linux/delay.h>
 16#include <linux/usb.h>
 17#include <linux/usb/gadget.h>
 18#include <linux/usb/otg.h>
 19#include <linux/usb/otg-fsm.h>
 20
 21#ifdef VERBOSE
 22#define VDBG(fmt, args...) pr_debug("[%s]  " fmt, \
 23				 __func__, ## args)
 24#else
 25#define VDBG(stuff...)	do {} while (0)
 26#endif
 27
 28/* Change USB protocol when there is a protocol change */
 29static int otg_set_protocol(struct otg_fsm *fsm, int protocol)
 30{
 31	int ret = 0;
 32
 33	if (fsm->protocol != protocol) {
 34		VDBG("Changing role fsm->protocol= %d; new protocol= %d\n",
 35			fsm->protocol, protocol);
 36		/* stop old protocol */
 37		if (fsm->protocol == PROTO_HOST)
 38			ret = otg_start_host(fsm, 0);
 39		else if (fsm->protocol == PROTO_GADGET)
 40			ret = otg_start_gadget(fsm, 0);
 41		if (ret)
 42			return ret;
 43
 44		/* start new protocol */
 45		if (protocol == PROTO_HOST)
 46			ret = otg_start_host(fsm, 1);
 47		else if (protocol == PROTO_GADGET)
 48			ret = otg_start_gadget(fsm, 1);
 49		if (ret)
 50			return ret;
 51
 52		fsm->protocol = protocol;
 53		return 0;
 54	}
 55
 56	return 0;
 57}
 58
 59/* Called when leaving a state.  Do state clean up jobs here */
 60static void otg_leave_state(struct otg_fsm *fsm, enum usb_otg_state old_state)
 61{
 62	switch (old_state) {
 63	case OTG_STATE_B_IDLE:
 64		otg_del_timer(fsm, B_SE0_SRP);
 65		fsm->b_se0_srp = 0;
 66		fsm->adp_sns = 0;
 67		fsm->adp_prb = 0;
 68		break;
 69	case OTG_STATE_B_SRP_INIT:
 70		fsm->data_pulse = 0;
 71		fsm->b_srp_done = 0;
 72		break;
 73	case OTG_STATE_B_PERIPHERAL:
 74		if (fsm->otg->gadget)
 75			fsm->otg->gadget->host_request_flag = 0;
 76		break;
 77	case OTG_STATE_B_WAIT_ACON:
 78		otg_del_timer(fsm, B_ASE0_BRST);
 79		fsm->b_ase0_brst_tmout = 0;
 80		break;
 81	case OTG_STATE_B_HOST:
 82		break;
 83	case OTG_STATE_A_IDLE:
 84		fsm->adp_prb = 0;
 85		break;
 86	case OTG_STATE_A_WAIT_VRISE:
 87		otg_del_timer(fsm, A_WAIT_VRISE);
 88		fsm->a_wait_vrise_tmout = 0;
 89		break;
 90	case OTG_STATE_A_WAIT_BCON:
 91		otg_del_timer(fsm, A_WAIT_BCON);
 92		fsm->a_wait_bcon_tmout = 0;
 93		break;
 94	case OTG_STATE_A_HOST:
 95		otg_del_timer(fsm, A_WAIT_ENUM);
 96		break;
 97	case OTG_STATE_A_SUSPEND:
 98		otg_del_timer(fsm, A_AIDL_BDIS);
 99		fsm->a_aidl_bdis_tmout = 0;
100		fsm->a_suspend_req_inf = 0;
101		break;
102	case OTG_STATE_A_PERIPHERAL:
103		otg_del_timer(fsm, A_BIDL_ADIS);
104		fsm->a_bidl_adis_tmout = 0;
105		if (fsm->otg->gadget)
106			fsm->otg->gadget->host_request_flag = 0;
107		break;
108	case OTG_STATE_A_WAIT_VFALL:
109		otg_del_timer(fsm, A_WAIT_VFALL);
110		fsm->a_wait_vfall_tmout = 0;
111		otg_del_timer(fsm, A_WAIT_VRISE);
112		break;
113	case OTG_STATE_A_VBUS_ERR:
114		break;
115	default:
116		break;
117	}
118}
119
120static void otg_hnp_polling_work(struct work_struct *work)
121{
122	struct otg_fsm *fsm = container_of(to_delayed_work(work),
123				struct otg_fsm, hnp_polling_work);
124	struct usb_device *udev;
125	enum usb_otg_state state = fsm->otg->state;
126	u8 flag;
127	int retval;
128
129	if (state != OTG_STATE_A_HOST && state != OTG_STATE_B_HOST)
130		return;
131
132	udev = usb_hub_find_child(fsm->otg->host->root_hub, 1);
133	if (!udev) {
134		dev_err(fsm->otg->host->controller,
135			"no usb dev connected, can't start HNP polling\n");
136		return;
137	}
138
139	*fsm->host_req_flag = 0;
140	/* Get host request flag from connected USB device */
141	retval = usb_control_msg(udev,
142				usb_rcvctrlpipe(udev, 0),
143				USB_REQ_GET_STATUS,
144				USB_DIR_IN | USB_RECIP_DEVICE,
145				0,
146				OTG_STS_SELECTOR,
147				fsm->host_req_flag,
148				1,
149				USB_CTRL_GET_TIMEOUT);
150	if (retval != 1) {
151		dev_err(&udev->dev, "Get one byte OTG status failed\n");
152		return;
153	}
154
155	flag = *fsm->host_req_flag;
156	if (flag == 0) {
157		/* Continue HNP polling */
158		schedule_delayed_work(&fsm->hnp_polling_work,
159					msecs_to_jiffies(T_HOST_REQ_POLL));
160		return;
161	} else if (flag != HOST_REQUEST_FLAG) {
162		dev_err(&udev->dev, "host request flag %d is invalid\n", flag);
163		return;
164	}
165
166	/* Host request flag is set */
167	if (state == OTG_STATE_A_HOST) {
168		/* Set b_hnp_enable */
169		if (!fsm->otg->host->b_hnp_enable) {
170			retval = usb_control_msg(udev,
171					usb_sndctrlpipe(udev, 0),
172					USB_REQ_SET_FEATURE, 0,
173					USB_DEVICE_B_HNP_ENABLE,
174					0, NULL, 0,
175					USB_CTRL_SET_TIMEOUT);
176			if (retval >= 0)
177				fsm->otg->host->b_hnp_enable = 1;
178		}
179		fsm->a_bus_req = 0;
180	} else if (state == OTG_STATE_B_HOST) {
181		fsm->b_bus_req = 0;
182	}
183
184	otg_statemachine(fsm);
185}
186
187static void otg_start_hnp_polling(struct otg_fsm *fsm)
188{
189	/*
190	 * The memory of host_req_flag should be allocated by
191	 * controller driver, otherwise, hnp polling is not started.
192	 */
193	if (!fsm->host_req_flag)
194		return;
195
196	if (!fsm->hnp_work_inited) {
197		INIT_DELAYED_WORK(&fsm->hnp_polling_work, otg_hnp_polling_work);
198		fsm->hnp_work_inited = true;
199	}
200
201	schedule_delayed_work(&fsm->hnp_polling_work,
202					msecs_to_jiffies(T_HOST_REQ_POLL));
203}
204
205/* Called when entering a state */
206static int otg_set_state(struct otg_fsm *fsm, enum usb_otg_state new_state)
207{
208	if (fsm->otg->state == new_state)
209		return 0;
210	VDBG("Set state: %s\n", usb_otg_state_string(new_state));
211	otg_leave_state(fsm, fsm->otg->state);
212	switch (new_state) {
213	case OTG_STATE_B_IDLE:
214		otg_drv_vbus(fsm, 0);
215		otg_chrg_vbus(fsm, 0);
216		otg_loc_conn(fsm, 0);
217		otg_loc_sof(fsm, 0);
218		/*
219		 * Driver is responsible for starting ADP probing
220		 * if ADP sensing times out.
221		 */
222		otg_start_adp_sns(fsm);
223		otg_set_protocol(fsm, PROTO_UNDEF);
224		otg_add_timer(fsm, B_SE0_SRP);
225		break;
226	case OTG_STATE_B_SRP_INIT:
227		otg_start_pulse(fsm);
228		otg_loc_sof(fsm, 0);
229		otg_set_protocol(fsm, PROTO_UNDEF);
230		otg_add_timer(fsm, B_SRP_FAIL);
231		break;
232	case OTG_STATE_B_PERIPHERAL:
233		otg_chrg_vbus(fsm, 0);
234		otg_loc_sof(fsm, 0);
235		otg_set_protocol(fsm, PROTO_GADGET);
236		otg_loc_conn(fsm, 1);
237		break;
238	case OTG_STATE_B_WAIT_ACON:
239		otg_chrg_vbus(fsm, 0);
240		otg_loc_conn(fsm, 0);
241		otg_loc_sof(fsm, 0);
242		otg_set_protocol(fsm, PROTO_HOST);
243		otg_add_timer(fsm, B_ASE0_BRST);
244		fsm->a_bus_suspend = 0;
245		break;
246	case OTG_STATE_B_HOST:
247		otg_chrg_vbus(fsm, 0);
248		otg_loc_conn(fsm, 0);
249		otg_loc_sof(fsm, 1);
250		otg_set_protocol(fsm, PROTO_HOST);
251		usb_bus_start_enum(fsm->otg->host,
252				fsm->otg->host->otg_port);
253		otg_start_hnp_polling(fsm);
254		break;
255	case OTG_STATE_A_IDLE:
256		otg_drv_vbus(fsm, 0);
257		otg_chrg_vbus(fsm, 0);
258		otg_loc_conn(fsm, 0);
259		otg_loc_sof(fsm, 0);
260		otg_start_adp_prb(fsm);
261		otg_set_protocol(fsm, PROTO_HOST);
262		break;
263	case OTG_STATE_A_WAIT_VRISE:
264		otg_drv_vbus(fsm, 1);
265		otg_loc_conn(fsm, 0);
266		otg_loc_sof(fsm, 0);
267		otg_set_protocol(fsm, PROTO_HOST);
268		otg_add_timer(fsm, A_WAIT_VRISE);
269		break;
270	case OTG_STATE_A_WAIT_BCON:
271		otg_drv_vbus(fsm, 1);
272		otg_loc_conn(fsm, 0);
273		otg_loc_sof(fsm, 0);
274		otg_set_protocol(fsm, PROTO_HOST);
275		otg_add_timer(fsm, A_WAIT_BCON);
276		break;
277	case OTG_STATE_A_HOST:
278		otg_drv_vbus(fsm, 1);
279		otg_loc_conn(fsm, 0);
280		otg_loc_sof(fsm, 1);
281		otg_set_protocol(fsm, PROTO_HOST);
282		/*
283		 * When HNP is triggered while a_bus_req = 0, a_host will
284		 * suspend too fast to complete a_set_b_hnp_en
285		 */
286		if (!fsm->a_bus_req || fsm->a_suspend_req_inf)
287			otg_add_timer(fsm, A_WAIT_ENUM);
288		otg_start_hnp_polling(fsm);
289		break;
290	case OTG_STATE_A_SUSPEND:
291		otg_drv_vbus(fsm, 1);
292		otg_loc_conn(fsm, 0);
293		otg_loc_sof(fsm, 0);
294		otg_set_protocol(fsm, PROTO_HOST);
295		otg_add_timer(fsm, A_AIDL_BDIS);
296
297		break;
298	case OTG_STATE_A_PERIPHERAL:
299		otg_loc_sof(fsm, 0);
300		otg_set_protocol(fsm, PROTO_GADGET);
301		otg_drv_vbus(fsm, 1);
302		otg_loc_conn(fsm, 1);
303		otg_add_timer(fsm, A_BIDL_ADIS);
304		break;
305	case OTG_STATE_A_WAIT_VFALL:
306		otg_drv_vbus(fsm, 0);
307		otg_loc_conn(fsm, 0);
308		otg_loc_sof(fsm, 0);
309		otg_set_protocol(fsm, PROTO_HOST);
310		otg_add_timer(fsm, A_WAIT_VFALL);
311		break;
312	case OTG_STATE_A_VBUS_ERR:
313		otg_drv_vbus(fsm, 0);
314		otg_loc_conn(fsm, 0);
315		otg_loc_sof(fsm, 0);
316		otg_set_protocol(fsm, PROTO_UNDEF);
317		break;
318	default:
319		break;
320	}
321
322	fsm->otg->state = new_state;
323	fsm->state_changed = 1;
324	return 0;
325}
326
327/* State change judgement */
328int otg_statemachine(struct otg_fsm *fsm)
329{
330	enum usb_otg_state state;
331
332	mutex_lock(&fsm->lock);
333
334	state = fsm->otg->state;
335	fsm->state_changed = 0;
336	/* State machine state change judgement */
337
338	switch (state) {
339	case OTG_STATE_UNDEFINED:
340		VDBG("fsm->id = %d\n", fsm->id);
341		if (fsm->id)
342			otg_set_state(fsm, OTG_STATE_B_IDLE);
343		else
344			otg_set_state(fsm, OTG_STATE_A_IDLE);
345		break;
346	case OTG_STATE_B_IDLE:
347		if (!fsm->id)
348			otg_set_state(fsm, OTG_STATE_A_IDLE);
349		else if (fsm->b_sess_vld && fsm->otg->gadget)
350			otg_set_state(fsm, OTG_STATE_B_PERIPHERAL);
351		else if ((fsm->b_bus_req || fsm->adp_change || fsm->power_up) &&
352				fsm->b_ssend_srp && fsm->b_se0_srp)
353			otg_set_state(fsm, OTG_STATE_B_SRP_INIT);
354		break;
355	case OTG_STATE_B_SRP_INIT:
356		if (!fsm->id || fsm->b_srp_done)
357			otg_set_state(fsm, OTG_STATE_B_IDLE);
358		break;
359	case OTG_STATE_B_PERIPHERAL:
360		if (!fsm->id || !fsm->b_sess_vld)
361			otg_set_state(fsm, OTG_STATE_B_IDLE);
362		else if (fsm->b_bus_req && fsm->otg->
363				gadget->b_hnp_enable && fsm->a_bus_suspend)
364			otg_set_state(fsm, OTG_STATE_B_WAIT_ACON);
365		break;
366	case OTG_STATE_B_WAIT_ACON:
367		if (fsm->a_conn)
368			otg_set_state(fsm, OTG_STATE_B_HOST);
369		else if (!fsm->id || !fsm->b_sess_vld)
370			otg_set_state(fsm, OTG_STATE_B_IDLE);
371		else if (fsm->a_bus_resume || fsm->b_ase0_brst_tmout) {
372			fsm->b_ase0_brst_tmout = 0;
373			otg_set_state(fsm, OTG_STATE_B_PERIPHERAL);
374		}
375		break;
376	case OTG_STATE_B_HOST:
377		if (!fsm->id || !fsm->b_sess_vld)
378			otg_set_state(fsm, OTG_STATE_B_IDLE);
379		else if (!fsm->b_bus_req || !fsm->a_conn || fsm->test_device)
380			otg_set_state(fsm, OTG_STATE_B_PERIPHERAL);
381		break;
382	case OTG_STATE_A_IDLE:
383		if (fsm->id)
384			otg_set_state(fsm, OTG_STATE_B_IDLE);
385		else if (!fsm->a_bus_drop && (fsm->a_bus_req ||
386			  fsm->a_srp_det || fsm->adp_change || fsm->power_up))
387			otg_set_state(fsm, OTG_STATE_A_WAIT_VRISE);
388		break;
389	case OTG_STATE_A_WAIT_VRISE:
390		if (fsm->a_vbus_vld)
391			otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
392		else if (fsm->id || fsm->a_bus_drop ||
393				fsm->a_wait_vrise_tmout)
394			otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
395		break;
396	case OTG_STATE_A_WAIT_BCON:
397		if (!fsm->a_vbus_vld)
398			otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
399		else if (fsm->b_conn)
400			otg_set_state(fsm, OTG_STATE_A_HOST);
401		else if (fsm->id || fsm->a_bus_drop || fsm->a_wait_bcon_tmout)
402			otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
403		break;
404	case OTG_STATE_A_HOST:
405		if (fsm->id || fsm->a_bus_drop)
406			otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
407		else if ((!fsm->a_bus_req || fsm->a_suspend_req_inf) &&
408				fsm->otg->host->b_hnp_enable)
409			otg_set_state(fsm, OTG_STATE_A_SUSPEND);
410		else if (!fsm->b_conn)
411			otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
412		else if (!fsm->a_vbus_vld)
413			otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
414		break;
415	case OTG_STATE_A_SUSPEND:
416		if (!fsm->b_conn && fsm->otg->host->b_hnp_enable)
417			otg_set_state(fsm, OTG_STATE_A_PERIPHERAL);
418		else if (!fsm->b_conn && !fsm->otg->host->b_hnp_enable)
419			otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
420		else if (fsm->a_bus_req || fsm->b_bus_resume)
421			otg_set_state(fsm, OTG_STATE_A_HOST);
422		else if (fsm->id || fsm->a_bus_drop || fsm->a_aidl_bdis_tmout)
423			otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
424		else if (!fsm->a_vbus_vld)
425			otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
426		break;
427	case OTG_STATE_A_PERIPHERAL:
428		if (fsm->id || fsm->a_bus_drop)
429			otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
430		else if (fsm->a_bidl_adis_tmout || fsm->b_bus_suspend)
431			otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
432		else if (!fsm->a_vbus_vld)
433			otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
434		break;
435	case OTG_STATE_A_WAIT_VFALL:
436		if (fsm->a_wait_vfall_tmout)
437			otg_set_state(fsm, OTG_STATE_A_IDLE);
438		break;
439	case OTG_STATE_A_VBUS_ERR:
440		if (fsm->id || fsm->a_bus_drop || fsm->a_clr_err)
441			otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
442		break;
443	default:
444		break;
445	}
446	mutex_unlock(&fsm->lock);
447
448	VDBG("quit statemachine, changed = %d\n", fsm->state_changed);
449	return fsm->state_changed;
450}
451EXPORT_SYMBOL_GPL(otg_statemachine);
452MODULE_LICENSE("GPL");