xref: /openbmc/linux/drivers/usb/chipidea/otg_fsm.c (revision 8b235f2f)
1 /*
2  * otg_fsm.c - ChipIdea USB IP core OTG FSM driver
3  *
4  * Copyright (C) 2014 Freescale Semiconductor, Inc.
5  *
6  * Author: Jun Li
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License version 2 as
10  * published by the Free Software Foundation.
11  */
12 
13 /*
14  * This file mainly handles OTG fsm, it includes OTG fsm operations
15  * for HNP and SRP.
16  *
17  * TODO List
18  * - ADP
19  * - OTG test device
20  */
21 
22 #include <linux/usb/otg.h>
23 #include <linux/usb/gadget.h>
24 #include <linux/usb/hcd.h>
25 #include <linux/usb/chipidea.h>
26 #include <linux/regulator/consumer.h>
27 
28 #include "ci.h"
29 #include "bits.h"
30 #include "otg.h"
31 #include "otg_fsm.h"
32 
33 /* Add for otg: interact with user space app */
34 static ssize_t
35 get_a_bus_req(struct device *dev, struct device_attribute *attr, char *buf)
36 {
37 	char		*next;
38 	unsigned	size, t;
39 	struct ci_hdrc	*ci = dev_get_drvdata(dev);
40 
41 	next = buf;
42 	size = PAGE_SIZE;
43 	t = scnprintf(next, size, "%d\n", ci->fsm.a_bus_req);
44 	size -= t;
45 	next += t;
46 
47 	return PAGE_SIZE - size;
48 }
49 
50 static ssize_t
51 set_a_bus_req(struct device *dev, struct device_attribute *attr,
52 					const char *buf, size_t count)
53 {
54 	struct ci_hdrc *ci = dev_get_drvdata(dev);
55 
56 	if (count > 2)
57 		return -1;
58 
59 	mutex_lock(&ci->fsm.lock);
60 	if (buf[0] == '0') {
61 		ci->fsm.a_bus_req = 0;
62 	} else if (buf[0] == '1') {
63 		/* If a_bus_drop is TRUE, a_bus_req can't be set */
64 		if (ci->fsm.a_bus_drop) {
65 			mutex_unlock(&ci->fsm.lock);
66 			return count;
67 		}
68 		ci->fsm.a_bus_req = 1;
69 	}
70 
71 	ci_otg_queue_work(ci);
72 	mutex_unlock(&ci->fsm.lock);
73 
74 	return count;
75 }
76 static DEVICE_ATTR(a_bus_req, S_IRUGO | S_IWUSR, get_a_bus_req, set_a_bus_req);
77 
78 static ssize_t
79 get_a_bus_drop(struct device *dev, struct device_attribute *attr, char *buf)
80 {
81 	char		*next;
82 	unsigned	size, t;
83 	struct ci_hdrc	*ci = dev_get_drvdata(dev);
84 
85 	next = buf;
86 	size = PAGE_SIZE;
87 	t = scnprintf(next, size, "%d\n", ci->fsm.a_bus_drop);
88 	size -= t;
89 	next += t;
90 
91 	return PAGE_SIZE - size;
92 }
93 
94 static ssize_t
95 set_a_bus_drop(struct device *dev, struct device_attribute *attr,
96 					const char *buf, size_t count)
97 {
98 	struct ci_hdrc	*ci = dev_get_drvdata(dev);
99 
100 	if (count > 2)
101 		return -1;
102 
103 	mutex_lock(&ci->fsm.lock);
104 	if (buf[0] == '0') {
105 		ci->fsm.a_bus_drop = 0;
106 	} else if (buf[0] == '1') {
107 		ci->fsm.a_bus_drop = 1;
108 		ci->fsm.a_bus_req = 0;
109 	}
110 
111 	ci_otg_queue_work(ci);
112 	mutex_unlock(&ci->fsm.lock);
113 
114 	return count;
115 }
116 static DEVICE_ATTR(a_bus_drop, S_IRUGO | S_IWUSR, get_a_bus_drop,
117 						set_a_bus_drop);
118 
119 static ssize_t
120 get_b_bus_req(struct device *dev, struct device_attribute *attr, char *buf)
121 {
122 	char		*next;
123 	unsigned	size, t;
124 	struct ci_hdrc	*ci = dev_get_drvdata(dev);
125 
126 	next = buf;
127 	size = PAGE_SIZE;
128 	t = scnprintf(next, size, "%d\n", ci->fsm.b_bus_req);
129 	size -= t;
130 	next += t;
131 
132 	return PAGE_SIZE - size;
133 }
134 
135 static ssize_t
136 set_b_bus_req(struct device *dev, struct device_attribute *attr,
137 					const char *buf, size_t count)
138 {
139 	struct ci_hdrc	*ci = dev_get_drvdata(dev);
140 
141 	if (count > 2)
142 		return -1;
143 
144 	mutex_lock(&ci->fsm.lock);
145 	if (buf[0] == '0')
146 		ci->fsm.b_bus_req = 0;
147 	else if (buf[0] == '1')
148 		ci->fsm.b_bus_req = 1;
149 
150 	ci_otg_queue_work(ci);
151 	mutex_unlock(&ci->fsm.lock);
152 
153 	return count;
154 }
155 static DEVICE_ATTR(b_bus_req, S_IRUGO | S_IWUSR, get_b_bus_req, set_b_bus_req);
156 
157 static ssize_t
158 set_a_clr_err(struct device *dev, struct device_attribute *attr,
159 					const char *buf, size_t count)
160 {
161 	struct ci_hdrc	*ci = dev_get_drvdata(dev);
162 
163 	if (count > 2)
164 		return -1;
165 
166 	mutex_lock(&ci->fsm.lock);
167 	if (buf[0] == '1')
168 		ci->fsm.a_clr_err = 1;
169 
170 	ci_otg_queue_work(ci);
171 	mutex_unlock(&ci->fsm.lock);
172 
173 	return count;
174 }
175 static DEVICE_ATTR(a_clr_err, S_IWUSR, NULL, set_a_clr_err);
176 
177 static struct attribute *inputs_attrs[] = {
178 	&dev_attr_a_bus_req.attr,
179 	&dev_attr_a_bus_drop.attr,
180 	&dev_attr_b_bus_req.attr,
181 	&dev_attr_a_clr_err.attr,
182 	NULL,
183 };
184 
185 static struct attribute_group inputs_attr_group = {
186 	.name = "inputs",
187 	.attrs = inputs_attrs,
188 };
189 
190 /*
191  * Keep this list in the same order as timers indexed
192  * by enum otg_fsm_timer in include/linux/usb/otg-fsm.h
193  */
194 static unsigned otg_timer_ms[] = {
195 	TA_WAIT_VRISE,
196 	TA_WAIT_VFALL,
197 	TA_WAIT_BCON,
198 	TA_AIDL_BDIS,
199 	TB_ASE0_BRST,
200 	TA_BIDL_ADIS,
201 	TB_SE0_SRP,
202 	TB_SRP_FAIL,
203 	0,
204 	TB_DATA_PLS,
205 	TB_SSEND_SRP,
206 };
207 
208 /*
209  * Add timer to active timer list
210  */
211 static void ci_otg_add_timer(struct ci_hdrc *ci, enum otg_fsm_timer t)
212 {
213 	unsigned long flags, timer_sec, timer_nsec;
214 
215 	if (t >= NUM_OTG_FSM_TIMERS)
216 		return;
217 
218 	spin_lock_irqsave(&ci->lock, flags);
219 	timer_sec = otg_timer_ms[t] / MSEC_PER_SEC;
220 	timer_nsec = (otg_timer_ms[t] % MSEC_PER_SEC) * NSEC_PER_MSEC;
221 	ci->hr_timeouts[t] = ktime_add(ktime_get(),
222 				ktime_set(timer_sec, timer_nsec));
223 	ci->enabled_otg_timer_bits |= (1 << t);
224 	if ((ci->next_otg_timer == NUM_OTG_FSM_TIMERS) ||
225 			(ci->hr_timeouts[ci->next_otg_timer].tv64 >
226 						ci->hr_timeouts[t].tv64)) {
227 			ci->next_otg_timer = t;
228 			hrtimer_start_range_ns(&ci->otg_fsm_hrtimer,
229 					ci->hr_timeouts[t], NSEC_PER_MSEC,
230 							HRTIMER_MODE_ABS);
231 	}
232 	spin_unlock_irqrestore(&ci->lock, flags);
233 }
234 
235 /*
236  * Remove timer from active timer list
237  */
238 static void ci_otg_del_timer(struct ci_hdrc *ci, enum otg_fsm_timer t)
239 {
240 	unsigned long flags, enabled_timer_bits;
241 	enum otg_fsm_timer cur_timer, next_timer = NUM_OTG_FSM_TIMERS;
242 
243 	if ((t >= NUM_OTG_FSM_TIMERS) ||
244 			!(ci->enabled_otg_timer_bits & (1 << t)))
245 		return;
246 
247 	spin_lock_irqsave(&ci->lock, flags);
248 	ci->enabled_otg_timer_bits &= ~(1 << t);
249 	if (ci->next_otg_timer == t) {
250 		if (ci->enabled_otg_timer_bits == 0) {
251 			/* No enabled timers after delete it */
252 			hrtimer_cancel(&ci->otg_fsm_hrtimer);
253 			ci->next_otg_timer = NUM_OTG_FSM_TIMERS;
254 		} else {
255 			/* Find the next timer */
256 			enabled_timer_bits = ci->enabled_otg_timer_bits;
257 			for_each_set_bit(cur_timer, &enabled_timer_bits,
258 							NUM_OTG_FSM_TIMERS) {
259 				if ((next_timer == NUM_OTG_FSM_TIMERS) ||
260 					(ci->hr_timeouts[next_timer].tv64 <
261 					ci->hr_timeouts[cur_timer].tv64))
262 					next_timer = cur_timer;
263 			}
264 		}
265 	}
266 	if (next_timer != NUM_OTG_FSM_TIMERS) {
267 		ci->next_otg_timer = next_timer;
268 		hrtimer_start_range_ns(&ci->otg_fsm_hrtimer,
269 			ci->hr_timeouts[next_timer], NSEC_PER_MSEC,
270 							HRTIMER_MODE_ABS);
271 	}
272 	spin_unlock_irqrestore(&ci->lock, flags);
273 }
274 
275 /* OTG FSM timer handlers */
276 static int a_wait_vrise_tmout(struct ci_hdrc *ci)
277 {
278 	ci->fsm.a_wait_vrise_tmout = 1;
279 	return 0;
280 }
281 
282 static int a_wait_vfall_tmout(struct ci_hdrc *ci)
283 {
284 	ci->fsm.a_wait_vfall_tmout = 1;
285 	return 0;
286 }
287 
288 static int a_wait_bcon_tmout(struct ci_hdrc *ci)
289 {
290 	ci->fsm.a_wait_bcon_tmout = 1;
291 	return 0;
292 }
293 
294 static int a_aidl_bdis_tmout(struct ci_hdrc *ci)
295 {
296 	ci->fsm.a_aidl_bdis_tmout = 1;
297 	return 0;
298 }
299 
300 static int b_ase0_brst_tmout(struct ci_hdrc *ci)
301 {
302 	ci->fsm.b_ase0_brst_tmout = 1;
303 	return 0;
304 }
305 
306 static int a_bidl_adis_tmout(struct ci_hdrc *ci)
307 {
308 	ci->fsm.a_bidl_adis_tmout = 1;
309 	return 0;
310 }
311 
312 static int b_se0_srp_tmout(struct ci_hdrc *ci)
313 {
314 	ci->fsm.b_se0_srp = 1;
315 	return 0;
316 }
317 
318 static int b_srp_fail_tmout(struct ci_hdrc *ci)
319 {
320 	ci->fsm.b_srp_done = 1;
321 	return 1;
322 }
323 
324 static int b_data_pls_tmout(struct ci_hdrc *ci)
325 {
326 	ci->fsm.b_srp_done = 1;
327 	ci->fsm.b_bus_req = 0;
328 	if (ci->fsm.power_up)
329 		ci->fsm.power_up = 0;
330 	hw_write_otgsc(ci, OTGSC_HABA, 0);
331 	pm_runtime_put(ci->dev);
332 	return 0;
333 }
334 
335 static int b_ssend_srp_tmout(struct ci_hdrc *ci)
336 {
337 	ci->fsm.b_ssend_srp = 1;
338 	/* only vbus fall below B_sess_vld in b_idle state */
339 	if (ci->fsm.otg->state == OTG_STATE_B_IDLE)
340 		return 0;
341 	else
342 		return 1;
343 }
344 
345 /*
346  * Keep this list in the same order as timers indexed
347  * by enum otg_fsm_timer in include/linux/usb/otg-fsm.h
348  */
349 static int (*otg_timer_handlers[])(struct ci_hdrc *) = {
350 	a_wait_vrise_tmout,	/* A_WAIT_VRISE */
351 	a_wait_vfall_tmout,	/* A_WAIT_VFALL */
352 	a_wait_bcon_tmout,	/* A_WAIT_BCON */
353 	a_aidl_bdis_tmout,	/* A_AIDL_BDIS */
354 	b_ase0_brst_tmout,	/* B_ASE0_BRST */
355 	a_bidl_adis_tmout,	/* A_BIDL_ADIS */
356 	b_se0_srp_tmout,	/* B_SE0_SRP */
357 	b_srp_fail_tmout,	/* B_SRP_FAIL */
358 	NULL,			/* A_WAIT_ENUM */
359 	b_data_pls_tmout,	/* B_DATA_PLS */
360 	b_ssend_srp_tmout,	/* B_SSEND_SRP */
361 };
362 
363 /*
364  * Enable the next nearest enabled timer if have
365  */
366 static enum hrtimer_restart ci_otg_hrtimer_func(struct hrtimer *t)
367 {
368 	struct ci_hdrc *ci = container_of(t, struct ci_hdrc, otg_fsm_hrtimer);
369 	ktime_t	now, *timeout;
370 	unsigned long   enabled_timer_bits;
371 	unsigned long   flags;
372 	enum otg_fsm_timer cur_timer, next_timer = NUM_OTG_FSM_TIMERS;
373 	int ret = -EINVAL;
374 
375 	spin_lock_irqsave(&ci->lock, flags);
376 	enabled_timer_bits = ci->enabled_otg_timer_bits;
377 	ci->next_otg_timer = NUM_OTG_FSM_TIMERS;
378 
379 	now = ktime_get();
380 	for_each_set_bit(cur_timer, &enabled_timer_bits, NUM_OTG_FSM_TIMERS) {
381 		if (now.tv64 >= ci->hr_timeouts[cur_timer].tv64) {
382 			ci->enabled_otg_timer_bits &= ~(1 << cur_timer);
383 			if (otg_timer_handlers[cur_timer])
384 				ret = otg_timer_handlers[cur_timer](ci);
385 		} else {
386 			if ((next_timer == NUM_OTG_FSM_TIMERS) ||
387 				(ci->hr_timeouts[cur_timer].tv64 <
388 					ci->hr_timeouts[next_timer].tv64))
389 				next_timer = cur_timer;
390 		}
391 	}
392 	/* Enable the next nearest timer */
393 	if (next_timer < NUM_OTG_FSM_TIMERS) {
394 		timeout = &ci->hr_timeouts[next_timer];
395 		hrtimer_start_range_ns(&ci->otg_fsm_hrtimer, *timeout,
396 					NSEC_PER_MSEC, HRTIMER_MODE_ABS);
397 		ci->next_otg_timer = next_timer;
398 	}
399 	spin_unlock_irqrestore(&ci->lock, flags);
400 
401 	if (!ret)
402 		ci_otg_queue_work(ci);
403 
404 	return HRTIMER_NORESTART;
405 }
406 
407 /* Initialize timers */
408 static int ci_otg_init_timers(struct ci_hdrc *ci)
409 {
410 	hrtimer_init(&ci->otg_fsm_hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
411 	ci->otg_fsm_hrtimer.function = ci_otg_hrtimer_func;
412 
413 	return 0;
414 }
415 
416 /* -------------------------------------------------------------*/
417 /* Operations that will be called from OTG Finite State Machine */
418 /* -------------------------------------------------------------*/
419 static void ci_otg_fsm_add_timer(struct otg_fsm *fsm, enum otg_fsm_timer t)
420 {
421 	struct ci_hdrc	*ci = container_of(fsm, struct ci_hdrc, fsm);
422 
423 	if (t < NUM_OTG_FSM_TIMERS)
424 		ci_otg_add_timer(ci, t);
425 	return;
426 }
427 
428 static void ci_otg_fsm_del_timer(struct otg_fsm *fsm, enum otg_fsm_timer t)
429 {
430 	struct ci_hdrc	*ci = container_of(fsm, struct ci_hdrc, fsm);
431 
432 	if (t < NUM_OTG_FSM_TIMERS)
433 		ci_otg_del_timer(ci, t);
434 	return;
435 }
436 
437 /*
438  * A-device drive vbus: turn on vbus regulator and enable port power
439  * Data pulse irq should be disabled while vbus is on.
440  */
441 static void ci_otg_drv_vbus(struct otg_fsm *fsm, int on)
442 {
443 	int ret;
444 	struct ci_hdrc	*ci = container_of(fsm, struct ci_hdrc, fsm);
445 
446 	if (on) {
447 		/* Enable power power */
448 		hw_write(ci, OP_PORTSC, PORTSC_W1C_BITS | PORTSC_PP,
449 							PORTSC_PP);
450 		if (ci->platdata->reg_vbus) {
451 			ret = regulator_enable(ci->platdata->reg_vbus);
452 			if (ret) {
453 				dev_err(ci->dev,
454 				"Failed to enable vbus regulator, ret=%d\n",
455 				ret);
456 				return;
457 			}
458 		}
459 		/* Disable data pulse irq */
460 		hw_write_otgsc(ci, OTGSC_DPIE, 0);
461 
462 		fsm->a_srp_det = 0;
463 		fsm->power_up = 0;
464 	} else {
465 		if (ci->platdata->reg_vbus)
466 			regulator_disable(ci->platdata->reg_vbus);
467 
468 		fsm->a_bus_drop = 1;
469 		fsm->a_bus_req = 0;
470 	}
471 }
472 
473 /*
474  * Control data line by Run Stop bit.
475  */
476 static void ci_otg_loc_conn(struct otg_fsm *fsm, int on)
477 {
478 	struct ci_hdrc	*ci = container_of(fsm, struct ci_hdrc, fsm);
479 
480 	if (on)
481 		hw_write(ci, OP_USBCMD, USBCMD_RS, USBCMD_RS);
482 	else
483 		hw_write(ci, OP_USBCMD, USBCMD_RS, 0);
484 }
485 
486 /*
487  * Generate SOF by host.
488  * This is controlled through suspend/resume the port.
489  * In host mode, controller will automatically send SOF.
490  * Suspend will block the data on the port.
491  */
492 static void ci_otg_loc_sof(struct otg_fsm *fsm, int on)
493 {
494 	struct ci_hdrc	*ci = container_of(fsm, struct ci_hdrc, fsm);
495 
496 	if (on)
497 		hw_write(ci, OP_PORTSC, PORTSC_W1C_BITS | PORTSC_FPR,
498 							PORTSC_FPR);
499 	else
500 		hw_write(ci, OP_PORTSC, PORTSC_W1C_BITS | PORTSC_SUSP,
501 							PORTSC_SUSP);
502 }
503 
504 /*
505  * Start SRP pulsing by data-line pulsing,
506  * no v-bus pulsing followed
507  */
508 static void ci_otg_start_pulse(struct otg_fsm *fsm)
509 {
510 	struct ci_hdrc	*ci = container_of(fsm, struct ci_hdrc, fsm);
511 
512 	/* Hardware Assistant Data pulse */
513 	hw_write_otgsc(ci, OTGSC_HADP, OTGSC_HADP);
514 
515 	pm_runtime_get(ci->dev);
516 	ci_otg_add_timer(ci, B_DATA_PLS);
517 }
518 
519 static int ci_otg_start_host(struct otg_fsm *fsm, int on)
520 {
521 	struct ci_hdrc	*ci = container_of(fsm, struct ci_hdrc, fsm);
522 
523 	if (on) {
524 		ci_role_stop(ci);
525 		ci_role_start(ci, CI_ROLE_HOST);
526 	} else {
527 		ci_role_stop(ci);
528 		ci_role_start(ci, CI_ROLE_GADGET);
529 	}
530 	return 0;
531 }
532 
533 static int ci_otg_start_gadget(struct otg_fsm *fsm, int on)
534 {
535 	struct ci_hdrc	*ci = container_of(fsm, struct ci_hdrc, fsm);
536 
537 	if (on)
538 		usb_gadget_vbus_connect(&ci->gadget);
539 	else
540 		usb_gadget_vbus_disconnect(&ci->gadget);
541 
542 	return 0;
543 }
544 
545 static struct otg_fsm_ops ci_otg_ops = {
546 	.drv_vbus = ci_otg_drv_vbus,
547 	.loc_conn = ci_otg_loc_conn,
548 	.loc_sof = ci_otg_loc_sof,
549 	.start_pulse = ci_otg_start_pulse,
550 	.add_timer = ci_otg_fsm_add_timer,
551 	.del_timer = ci_otg_fsm_del_timer,
552 	.start_host = ci_otg_start_host,
553 	.start_gadget = ci_otg_start_gadget,
554 };
555 
556 int ci_otg_fsm_work(struct ci_hdrc *ci)
557 {
558 	/*
559 	 * Don't do fsm transition for B device
560 	 * when there is no gadget class driver
561 	 */
562 	if (ci->fsm.id && !(ci->driver) &&
563 		ci->fsm.otg->state < OTG_STATE_A_IDLE)
564 		return 0;
565 
566 	pm_runtime_get_sync(ci->dev);
567 	if (otg_statemachine(&ci->fsm)) {
568 		if (ci->fsm.otg->state == OTG_STATE_A_IDLE) {
569 			/*
570 			 * Further state change for cases:
571 			 * a_idle to b_idle; or
572 			 * a_idle to a_wait_vrise due to ID change(1->0), so
573 			 * B-dev becomes A-dev can try to start new session
574 			 * consequently; or
575 			 * a_idle to a_wait_vrise when power up
576 			 */
577 			if ((ci->fsm.id) || (ci->id_event) ||
578 						(ci->fsm.power_up)) {
579 				ci_otg_queue_work(ci);
580 			} else {
581 				/* Enable data pulse irq */
582 				hw_write(ci, OP_PORTSC, PORTSC_W1C_BITS |
583 								PORTSC_PP, 0);
584 				hw_write_otgsc(ci, OTGSC_DPIS, OTGSC_DPIS);
585 				hw_write_otgsc(ci, OTGSC_DPIE, OTGSC_DPIE);
586 			}
587 			if (ci->id_event)
588 				ci->id_event = false;
589 		} else if (ci->fsm.otg->state == OTG_STATE_B_IDLE) {
590 			if (ci->fsm.b_sess_vld) {
591 				ci->fsm.power_up = 0;
592 				/*
593 				 * Further transite to b_periphearl state
594 				 * when register gadget driver with vbus on
595 				 */
596 				ci_otg_queue_work(ci);
597 			}
598 		} else if (ci->fsm.otg->state == OTG_STATE_A_HOST) {
599 			pm_runtime_mark_last_busy(ci->dev);
600 			pm_runtime_put_autosuspend(ci->dev);
601 			return 0;
602 		}
603 	}
604 	pm_runtime_put_sync(ci->dev);
605 	return 0;
606 }
607 
608 /*
609  * Update fsm variables in each state if catching expected interrupts,
610  * called by otg fsm isr.
611  */
612 static void ci_otg_fsm_event(struct ci_hdrc *ci)
613 {
614 	u32 intr_sts, otg_bsess_vld, port_conn;
615 	struct otg_fsm *fsm = &ci->fsm;
616 
617 	intr_sts = hw_read_intr_status(ci);
618 	otg_bsess_vld = hw_read_otgsc(ci, OTGSC_BSV);
619 	port_conn = hw_read(ci, OP_PORTSC, PORTSC_CCS);
620 
621 	switch (ci->fsm.otg->state) {
622 	case OTG_STATE_A_WAIT_BCON:
623 		if (port_conn) {
624 			fsm->b_conn = 1;
625 			fsm->a_bus_req = 1;
626 			ci_otg_queue_work(ci);
627 		}
628 		break;
629 	case OTG_STATE_B_IDLE:
630 		if (otg_bsess_vld && (intr_sts & USBi_PCI) && port_conn) {
631 			fsm->b_sess_vld = 1;
632 			ci_otg_queue_work(ci);
633 		}
634 		break;
635 	case OTG_STATE_B_PERIPHERAL:
636 		if ((intr_sts & USBi_SLI) && port_conn && otg_bsess_vld) {
637 			fsm->a_bus_suspend = 1;
638 			ci_otg_queue_work(ci);
639 		} else if (intr_sts & USBi_PCI) {
640 			if (fsm->a_bus_suspend == 1)
641 				fsm->a_bus_suspend = 0;
642 		}
643 		break;
644 	case OTG_STATE_B_HOST:
645 		if ((intr_sts & USBi_PCI) && !port_conn) {
646 			fsm->a_conn = 0;
647 			fsm->b_bus_req = 0;
648 			ci_otg_queue_work(ci);
649 		}
650 		break;
651 	case OTG_STATE_A_PERIPHERAL:
652 		if (intr_sts & USBi_SLI) {
653 			 fsm->b_bus_suspend = 1;
654 			/*
655 			 * Init a timer to know how long this suspend
656 			 * will continue, if time out, indicates B no longer
657 			 * wants to be host role
658 			 */
659 			 ci_otg_add_timer(ci, A_BIDL_ADIS);
660 		}
661 
662 		if (intr_sts & USBi_URI)
663 			ci_otg_del_timer(ci, A_BIDL_ADIS);
664 
665 		if (intr_sts & USBi_PCI) {
666 			if (fsm->b_bus_suspend == 1) {
667 				ci_otg_del_timer(ci, A_BIDL_ADIS);
668 				fsm->b_bus_suspend = 0;
669 			}
670 		}
671 		break;
672 	case OTG_STATE_A_SUSPEND:
673 		if ((intr_sts & USBi_PCI) && !port_conn) {
674 			fsm->b_conn = 0;
675 
676 			/* if gadget driver is binded */
677 			if (ci->driver) {
678 				/* A device to be peripheral mode */
679 				ci->gadget.is_a_peripheral = 1;
680 			}
681 			ci_otg_queue_work(ci);
682 		}
683 		break;
684 	case OTG_STATE_A_HOST:
685 		if ((intr_sts & USBi_PCI) && !port_conn) {
686 			fsm->b_conn = 0;
687 			ci_otg_queue_work(ci);
688 		}
689 		break;
690 	case OTG_STATE_B_WAIT_ACON:
691 		if ((intr_sts & USBi_PCI) && port_conn) {
692 			fsm->a_conn = 1;
693 			ci_otg_queue_work(ci);
694 		}
695 		break;
696 	default:
697 		break;
698 	}
699 }
700 
701 /*
702  * ci_otg_irq - otg fsm related irq handling
703  * and also update otg fsm variable by monitoring usb host and udc
704  * state change interrupts.
705  * @ci: ci_hdrc
706  */
707 irqreturn_t ci_otg_fsm_irq(struct ci_hdrc *ci)
708 {
709 	irqreturn_t retval =  IRQ_NONE;
710 	u32 otgsc, otg_int_src = 0;
711 	struct otg_fsm *fsm = &ci->fsm;
712 
713 	otgsc = hw_read_otgsc(ci, ~0);
714 	otg_int_src = otgsc & OTGSC_INT_STATUS_BITS & (otgsc >> 8);
715 	fsm->id = (otgsc & OTGSC_ID) ? 1 : 0;
716 
717 	if (otg_int_src) {
718 		if (otg_int_src & OTGSC_DPIS) {
719 			hw_write_otgsc(ci, OTGSC_DPIS, OTGSC_DPIS);
720 			fsm->a_srp_det = 1;
721 			fsm->a_bus_drop = 0;
722 		} else if (otg_int_src & OTGSC_IDIS) {
723 			hw_write_otgsc(ci, OTGSC_IDIS, OTGSC_IDIS);
724 			if (fsm->id == 0) {
725 				fsm->a_bus_drop = 0;
726 				fsm->a_bus_req = 1;
727 				ci->id_event = true;
728 			}
729 		} else if (otg_int_src & OTGSC_BSVIS) {
730 			hw_write_otgsc(ci, OTGSC_BSVIS, OTGSC_BSVIS);
731 			if (otgsc & OTGSC_BSV) {
732 				fsm->b_sess_vld = 1;
733 				ci_otg_del_timer(ci, B_SSEND_SRP);
734 				ci_otg_del_timer(ci, B_SRP_FAIL);
735 				fsm->b_ssend_srp = 0;
736 			} else {
737 				fsm->b_sess_vld = 0;
738 				if (fsm->id)
739 					ci_otg_add_timer(ci, B_SSEND_SRP);
740 			}
741 		} else if (otg_int_src & OTGSC_AVVIS) {
742 			hw_write_otgsc(ci, OTGSC_AVVIS, OTGSC_AVVIS);
743 			if (otgsc & OTGSC_AVV) {
744 				fsm->a_vbus_vld = 1;
745 			} else {
746 				fsm->a_vbus_vld = 0;
747 				fsm->b_conn = 0;
748 			}
749 		}
750 		ci_otg_queue_work(ci);
751 		return IRQ_HANDLED;
752 	}
753 
754 	ci_otg_fsm_event(ci);
755 
756 	return retval;
757 }
758 
759 void ci_hdrc_otg_fsm_start(struct ci_hdrc *ci)
760 {
761 	ci_otg_queue_work(ci);
762 }
763 
764 int ci_hdrc_otg_fsm_init(struct ci_hdrc *ci)
765 {
766 	int retval = 0;
767 
768 	if (ci->phy)
769 		ci->otg.phy = ci->phy;
770 	else
771 		ci->otg.usb_phy = ci->usb_phy;
772 
773 	ci->otg.gadget = &ci->gadget;
774 	ci->fsm.otg = &ci->otg;
775 	ci->fsm.power_up = 1;
776 	ci->fsm.id = hw_read_otgsc(ci, OTGSC_ID) ? 1 : 0;
777 	ci->fsm.otg->state = OTG_STATE_UNDEFINED;
778 	ci->fsm.ops = &ci_otg_ops;
779 
780 	mutex_init(&ci->fsm.lock);
781 
782 	retval = ci_otg_init_timers(ci);
783 	if (retval) {
784 		dev_err(ci->dev, "Couldn't init OTG timers\n");
785 		return retval;
786 	}
787 	ci->enabled_otg_timer_bits = 0;
788 	ci->next_otg_timer = NUM_OTG_FSM_TIMERS;
789 
790 	retval = sysfs_create_group(&ci->dev->kobj, &inputs_attr_group);
791 	if (retval < 0) {
792 		dev_dbg(ci->dev,
793 			"Can't register sysfs attr group: %d\n", retval);
794 		return retval;
795 	}
796 
797 	/* Enable A vbus valid irq */
798 	hw_write_otgsc(ci, OTGSC_AVVIE, OTGSC_AVVIE);
799 
800 	if (ci->fsm.id) {
801 		ci->fsm.b_ssend_srp =
802 			hw_read_otgsc(ci, OTGSC_BSV) ? 0 : 1;
803 		ci->fsm.b_sess_vld =
804 			hw_read_otgsc(ci, OTGSC_BSV) ? 1 : 0;
805 		/* Enable BSV irq */
806 		hw_write_otgsc(ci, OTGSC_BSVIE, OTGSC_BSVIE);
807 	}
808 
809 	return 0;
810 }
811 
812 void ci_hdrc_otg_fsm_remove(struct ci_hdrc *ci)
813 {
814 	sysfs_remove_group(&ci->dev->kobj, &inputs_attr_group);
815 }
816