xref: /linux/drivers/usb/chipidea/otg_fsm.c (revision f3539c12d8196ce0a1993364d30b3a18908470d1)
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 		if (ci->fsm.otg->state == OTG_STATE_A_PERIPHERAL) {
70 			ci->gadget.host_request_flag = 1;
71 			mutex_unlock(&ci->fsm.lock);
72 			return count;
73 		}
74 	}
75 
76 	ci_otg_queue_work(ci);
77 	mutex_unlock(&ci->fsm.lock);
78 
79 	return count;
80 }
81 static DEVICE_ATTR(a_bus_req, S_IRUGO | S_IWUSR, get_a_bus_req, set_a_bus_req);
82 
83 static ssize_t
84 get_a_bus_drop(struct device *dev, struct device_attribute *attr, char *buf)
85 {
86 	char		*next;
87 	unsigned	size, t;
88 	struct ci_hdrc	*ci = dev_get_drvdata(dev);
89 
90 	next = buf;
91 	size = PAGE_SIZE;
92 	t = scnprintf(next, size, "%d\n", ci->fsm.a_bus_drop);
93 	size -= t;
94 	next += t;
95 
96 	return PAGE_SIZE - size;
97 }
98 
99 static ssize_t
100 set_a_bus_drop(struct device *dev, struct device_attribute *attr,
101 					const char *buf, size_t count)
102 {
103 	struct ci_hdrc	*ci = dev_get_drvdata(dev);
104 
105 	if (count > 2)
106 		return -1;
107 
108 	mutex_lock(&ci->fsm.lock);
109 	if (buf[0] == '0') {
110 		ci->fsm.a_bus_drop = 0;
111 	} else if (buf[0] == '1') {
112 		ci->fsm.a_bus_drop = 1;
113 		ci->fsm.a_bus_req = 0;
114 	}
115 
116 	ci_otg_queue_work(ci);
117 	mutex_unlock(&ci->fsm.lock);
118 
119 	return count;
120 }
121 static DEVICE_ATTR(a_bus_drop, S_IRUGO | S_IWUSR, get_a_bus_drop,
122 						set_a_bus_drop);
123 
124 static ssize_t
125 get_b_bus_req(struct device *dev, struct device_attribute *attr, char *buf)
126 {
127 	char		*next;
128 	unsigned	size, t;
129 	struct ci_hdrc	*ci = dev_get_drvdata(dev);
130 
131 	next = buf;
132 	size = PAGE_SIZE;
133 	t = scnprintf(next, size, "%d\n", ci->fsm.b_bus_req);
134 	size -= t;
135 	next += t;
136 
137 	return PAGE_SIZE - size;
138 }
139 
140 static ssize_t
141 set_b_bus_req(struct device *dev, struct device_attribute *attr,
142 					const char *buf, size_t count)
143 {
144 	struct ci_hdrc	*ci = dev_get_drvdata(dev);
145 
146 	if (count > 2)
147 		return -1;
148 
149 	mutex_lock(&ci->fsm.lock);
150 	if (buf[0] == '0')
151 		ci->fsm.b_bus_req = 0;
152 	else if (buf[0] == '1') {
153 		ci->fsm.b_bus_req = 1;
154 		if (ci->fsm.otg->state == OTG_STATE_B_PERIPHERAL) {
155 			ci->gadget.host_request_flag = 1;
156 			mutex_unlock(&ci->fsm.lock);
157 			return count;
158 		}
159 	}
160 
161 	ci_otg_queue_work(ci);
162 	mutex_unlock(&ci->fsm.lock);
163 
164 	return count;
165 }
166 static DEVICE_ATTR(b_bus_req, S_IRUGO | S_IWUSR, get_b_bus_req, set_b_bus_req);
167 
168 static ssize_t
169 set_a_clr_err(struct device *dev, struct device_attribute *attr,
170 					const char *buf, size_t count)
171 {
172 	struct ci_hdrc	*ci = dev_get_drvdata(dev);
173 
174 	if (count > 2)
175 		return -1;
176 
177 	mutex_lock(&ci->fsm.lock);
178 	if (buf[0] == '1')
179 		ci->fsm.a_clr_err = 1;
180 
181 	ci_otg_queue_work(ci);
182 	mutex_unlock(&ci->fsm.lock);
183 
184 	return count;
185 }
186 static DEVICE_ATTR(a_clr_err, S_IWUSR, NULL, set_a_clr_err);
187 
188 static struct attribute *inputs_attrs[] = {
189 	&dev_attr_a_bus_req.attr,
190 	&dev_attr_a_bus_drop.attr,
191 	&dev_attr_b_bus_req.attr,
192 	&dev_attr_a_clr_err.attr,
193 	NULL,
194 };
195 
196 static struct attribute_group inputs_attr_group = {
197 	.name = "inputs",
198 	.attrs = inputs_attrs,
199 };
200 
201 /*
202  * Keep this list in the same order as timers indexed
203  * by enum otg_fsm_timer in include/linux/usb/otg-fsm.h
204  */
205 static unsigned otg_timer_ms[] = {
206 	TA_WAIT_VRISE,
207 	TA_WAIT_VFALL,
208 	TA_WAIT_BCON,
209 	TA_AIDL_BDIS,
210 	TB_ASE0_BRST,
211 	TA_BIDL_ADIS,
212 	TB_AIDL_BDIS,
213 	TB_SE0_SRP,
214 	TB_SRP_FAIL,
215 	0,
216 	TB_DATA_PLS,
217 	TB_SSEND_SRP,
218 };
219 
220 /*
221  * Add timer to active timer list
222  */
223 static void ci_otg_add_timer(struct ci_hdrc *ci, enum otg_fsm_timer t)
224 {
225 	unsigned long flags, timer_sec, timer_nsec;
226 
227 	if (t >= NUM_OTG_FSM_TIMERS)
228 		return;
229 
230 	spin_lock_irqsave(&ci->lock, flags);
231 	timer_sec = otg_timer_ms[t] / MSEC_PER_SEC;
232 	timer_nsec = (otg_timer_ms[t] % MSEC_PER_SEC) * NSEC_PER_MSEC;
233 	ci->hr_timeouts[t] = ktime_add(ktime_get(),
234 				ktime_set(timer_sec, timer_nsec));
235 	ci->enabled_otg_timer_bits |= (1 << t);
236 	if ((ci->next_otg_timer == NUM_OTG_FSM_TIMERS) ||
237 			(ci->hr_timeouts[ci->next_otg_timer].tv64 >
238 						ci->hr_timeouts[t].tv64)) {
239 			ci->next_otg_timer = t;
240 			hrtimer_start_range_ns(&ci->otg_fsm_hrtimer,
241 					ci->hr_timeouts[t], NSEC_PER_MSEC,
242 							HRTIMER_MODE_ABS);
243 	}
244 	spin_unlock_irqrestore(&ci->lock, flags);
245 }
246 
247 /*
248  * Remove timer from active timer list
249  */
250 static void ci_otg_del_timer(struct ci_hdrc *ci, enum otg_fsm_timer t)
251 {
252 	unsigned long flags, enabled_timer_bits;
253 	enum otg_fsm_timer cur_timer, next_timer = NUM_OTG_FSM_TIMERS;
254 
255 	if ((t >= NUM_OTG_FSM_TIMERS) ||
256 			!(ci->enabled_otg_timer_bits & (1 << t)))
257 		return;
258 
259 	spin_lock_irqsave(&ci->lock, flags);
260 	ci->enabled_otg_timer_bits &= ~(1 << t);
261 	if (ci->next_otg_timer == t) {
262 		if (ci->enabled_otg_timer_bits == 0) {
263 			/* No enabled timers after delete it */
264 			hrtimer_cancel(&ci->otg_fsm_hrtimer);
265 			ci->next_otg_timer = NUM_OTG_FSM_TIMERS;
266 		} else {
267 			/* Find the next timer */
268 			enabled_timer_bits = ci->enabled_otg_timer_bits;
269 			for_each_set_bit(cur_timer, &enabled_timer_bits,
270 							NUM_OTG_FSM_TIMERS) {
271 				if ((next_timer == NUM_OTG_FSM_TIMERS) ||
272 					(ci->hr_timeouts[next_timer].tv64 <
273 					ci->hr_timeouts[cur_timer].tv64))
274 					next_timer = cur_timer;
275 			}
276 		}
277 	}
278 	if (next_timer != NUM_OTG_FSM_TIMERS) {
279 		ci->next_otg_timer = next_timer;
280 		hrtimer_start_range_ns(&ci->otg_fsm_hrtimer,
281 			ci->hr_timeouts[next_timer], NSEC_PER_MSEC,
282 							HRTIMER_MODE_ABS);
283 	}
284 	spin_unlock_irqrestore(&ci->lock, flags);
285 }
286 
287 /* OTG FSM timer handlers */
288 static int a_wait_vrise_tmout(struct ci_hdrc *ci)
289 {
290 	ci->fsm.a_wait_vrise_tmout = 1;
291 	return 0;
292 }
293 
294 static int a_wait_vfall_tmout(struct ci_hdrc *ci)
295 {
296 	ci->fsm.a_wait_vfall_tmout = 1;
297 	return 0;
298 }
299 
300 static int a_wait_bcon_tmout(struct ci_hdrc *ci)
301 {
302 	ci->fsm.a_wait_bcon_tmout = 1;
303 	return 0;
304 }
305 
306 static int a_aidl_bdis_tmout(struct ci_hdrc *ci)
307 {
308 	ci->fsm.a_aidl_bdis_tmout = 1;
309 	return 0;
310 }
311 
312 static int b_ase0_brst_tmout(struct ci_hdrc *ci)
313 {
314 	ci->fsm.b_ase0_brst_tmout = 1;
315 	return 0;
316 }
317 
318 static int a_bidl_adis_tmout(struct ci_hdrc *ci)
319 {
320 	ci->fsm.a_bidl_adis_tmout = 1;
321 	return 0;
322 }
323 
324 static int b_aidl_bdis_tmout(struct ci_hdrc *ci)
325 {
326 	ci->fsm.a_bus_suspend = 1;
327 	return 0;
328 }
329 
330 static int b_se0_srp_tmout(struct ci_hdrc *ci)
331 {
332 	ci->fsm.b_se0_srp = 1;
333 	return 0;
334 }
335 
336 static int b_srp_fail_tmout(struct ci_hdrc *ci)
337 {
338 	ci->fsm.b_srp_done = 1;
339 	return 1;
340 }
341 
342 static int b_data_pls_tmout(struct ci_hdrc *ci)
343 {
344 	ci->fsm.b_srp_done = 1;
345 	ci->fsm.b_bus_req = 0;
346 	if (ci->fsm.power_up)
347 		ci->fsm.power_up = 0;
348 	hw_write_otgsc(ci, OTGSC_HABA, 0);
349 	pm_runtime_put(ci->dev);
350 	return 0;
351 }
352 
353 static int b_ssend_srp_tmout(struct ci_hdrc *ci)
354 {
355 	ci->fsm.b_ssend_srp = 1;
356 	/* only vbus fall below B_sess_vld in b_idle state */
357 	if (ci->fsm.otg->state == OTG_STATE_B_IDLE)
358 		return 0;
359 	else
360 		return 1;
361 }
362 
363 /*
364  * Keep this list in the same order as timers indexed
365  * by enum otg_fsm_timer in include/linux/usb/otg-fsm.h
366  */
367 static int (*otg_timer_handlers[])(struct ci_hdrc *) = {
368 	a_wait_vrise_tmout,	/* A_WAIT_VRISE */
369 	a_wait_vfall_tmout,	/* A_WAIT_VFALL */
370 	a_wait_bcon_tmout,	/* A_WAIT_BCON */
371 	a_aidl_bdis_tmout,	/* A_AIDL_BDIS */
372 	b_ase0_brst_tmout,	/* B_ASE0_BRST */
373 	a_bidl_adis_tmout,	/* A_BIDL_ADIS */
374 	b_aidl_bdis_tmout,	/* B_AIDL_BDIS */
375 	b_se0_srp_tmout,	/* B_SE0_SRP */
376 	b_srp_fail_tmout,	/* B_SRP_FAIL */
377 	NULL,			/* A_WAIT_ENUM */
378 	b_data_pls_tmout,	/* B_DATA_PLS */
379 	b_ssend_srp_tmout,	/* B_SSEND_SRP */
380 };
381 
382 /*
383  * Enable the next nearest enabled timer if have
384  */
385 static enum hrtimer_restart ci_otg_hrtimer_func(struct hrtimer *t)
386 {
387 	struct ci_hdrc *ci = container_of(t, struct ci_hdrc, otg_fsm_hrtimer);
388 	ktime_t	now, *timeout;
389 	unsigned long   enabled_timer_bits;
390 	unsigned long   flags;
391 	enum otg_fsm_timer cur_timer, next_timer = NUM_OTG_FSM_TIMERS;
392 	int ret = -EINVAL;
393 
394 	spin_lock_irqsave(&ci->lock, flags);
395 	enabled_timer_bits = ci->enabled_otg_timer_bits;
396 	ci->next_otg_timer = NUM_OTG_FSM_TIMERS;
397 
398 	now = ktime_get();
399 	for_each_set_bit(cur_timer, &enabled_timer_bits, NUM_OTG_FSM_TIMERS) {
400 		if (now.tv64 >= ci->hr_timeouts[cur_timer].tv64) {
401 			ci->enabled_otg_timer_bits &= ~(1 << cur_timer);
402 			if (otg_timer_handlers[cur_timer])
403 				ret = otg_timer_handlers[cur_timer](ci);
404 		} else {
405 			if ((next_timer == NUM_OTG_FSM_TIMERS) ||
406 				(ci->hr_timeouts[cur_timer].tv64 <
407 					ci->hr_timeouts[next_timer].tv64))
408 				next_timer = cur_timer;
409 		}
410 	}
411 	/* Enable the next nearest timer */
412 	if (next_timer < NUM_OTG_FSM_TIMERS) {
413 		timeout = &ci->hr_timeouts[next_timer];
414 		hrtimer_start_range_ns(&ci->otg_fsm_hrtimer, *timeout,
415 					NSEC_PER_MSEC, HRTIMER_MODE_ABS);
416 		ci->next_otg_timer = next_timer;
417 	}
418 	spin_unlock_irqrestore(&ci->lock, flags);
419 
420 	if (!ret)
421 		ci_otg_queue_work(ci);
422 
423 	return HRTIMER_NORESTART;
424 }
425 
426 /* Initialize timers */
427 static int ci_otg_init_timers(struct ci_hdrc *ci)
428 {
429 	hrtimer_init(&ci->otg_fsm_hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
430 	ci->otg_fsm_hrtimer.function = ci_otg_hrtimer_func;
431 
432 	return 0;
433 }
434 
435 /* -------------------------------------------------------------*/
436 /* Operations that will be called from OTG Finite State Machine */
437 /* -------------------------------------------------------------*/
438 static void ci_otg_fsm_add_timer(struct otg_fsm *fsm, enum otg_fsm_timer t)
439 {
440 	struct ci_hdrc	*ci = container_of(fsm, struct ci_hdrc, fsm);
441 
442 	if (t < NUM_OTG_FSM_TIMERS)
443 		ci_otg_add_timer(ci, t);
444 	return;
445 }
446 
447 static void ci_otg_fsm_del_timer(struct otg_fsm *fsm, enum otg_fsm_timer t)
448 {
449 	struct ci_hdrc	*ci = container_of(fsm, struct ci_hdrc, fsm);
450 
451 	if (t < NUM_OTG_FSM_TIMERS)
452 		ci_otg_del_timer(ci, t);
453 	return;
454 }
455 
456 /*
457  * A-device drive vbus: turn on vbus regulator and enable port power
458  * Data pulse irq should be disabled while vbus is on.
459  */
460 static void ci_otg_drv_vbus(struct otg_fsm *fsm, int on)
461 {
462 	int ret;
463 	struct ci_hdrc	*ci = container_of(fsm, struct ci_hdrc, fsm);
464 
465 	if (on) {
466 		/* Enable power power */
467 		hw_write(ci, OP_PORTSC, PORTSC_W1C_BITS | PORTSC_PP,
468 							PORTSC_PP);
469 		if (ci->platdata->reg_vbus) {
470 			ret = regulator_enable(ci->platdata->reg_vbus);
471 			if (ret) {
472 				dev_err(ci->dev,
473 				"Failed to enable vbus regulator, ret=%d\n",
474 				ret);
475 				return;
476 			}
477 		}
478 		/* Disable data pulse irq */
479 		hw_write_otgsc(ci, OTGSC_DPIE, 0);
480 
481 		fsm->a_srp_det = 0;
482 		fsm->power_up = 0;
483 	} else {
484 		if (ci->platdata->reg_vbus)
485 			regulator_disable(ci->platdata->reg_vbus);
486 
487 		fsm->a_bus_drop = 1;
488 		fsm->a_bus_req = 0;
489 	}
490 }
491 
492 /*
493  * Control data line by Run Stop bit.
494  */
495 static void ci_otg_loc_conn(struct otg_fsm *fsm, int on)
496 {
497 	struct ci_hdrc	*ci = container_of(fsm, struct ci_hdrc, fsm);
498 
499 	if (on)
500 		hw_write(ci, OP_USBCMD, USBCMD_RS, USBCMD_RS);
501 	else
502 		hw_write(ci, OP_USBCMD, USBCMD_RS, 0);
503 }
504 
505 /*
506  * Generate SOF by host.
507  * In host mode, controller will automatically send SOF.
508  * Suspend will block the data on the port.
509  *
510  * This is controlled through usbcore by usb autosuspend,
511  * so the usb device class driver need support autosuspend,
512  * otherwise the bus suspend will not happen.
513  */
514 static void ci_otg_loc_sof(struct otg_fsm *fsm, int on)
515 {
516 	struct usb_device *udev;
517 
518 	if (!fsm->otg->host)
519 		return;
520 
521 	udev = usb_hub_find_child(fsm->otg->host->root_hub, 1);
522 	if (!udev)
523 		return;
524 
525 	if (on) {
526 		usb_disable_autosuspend(udev);
527 	} else {
528 		pm_runtime_set_autosuspend_delay(&udev->dev, 0);
529 		usb_enable_autosuspend(udev);
530 	}
531 }
532 
533 /*
534  * Start SRP pulsing by data-line pulsing,
535  * no v-bus pulsing followed
536  */
537 static void ci_otg_start_pulse(struct otg_fsm *fsm)
538 {
539 	struct ci_hdrc	*ci = container_of(fsm, struct ci_hdrc, fsm);
540 
541 	/* Hardware Assistant Data pulse */
542 	hw_write_otgsc(ci, OTGSC_HADP, OTGSC_HADP);
543 
544 	pm_runtime_get(ci->dev);
545 	ci_otg_add_timer(ci, B_DATA_PLS);
546 }
547 
548 static int ci_otg_start_host(struct otg_fsm *fsm, int on)
549 {
550 	struct ci_hdrc	*ci = container_of(fsm, struct ci_hdrc, fsm);
551 
552 	if (on) {
553 		ci_role_stop(ci);
554 		ci_role_start(ci, CI_ROLE_HOST);
555 	} else {
556 		ci_role_stop(ci);
557 		ci_role_start(ci, CI_ROLE_GADGET);
558 	}
559 	return 0;
560 }
561 
562 static int ci_otg_start_gadget(struct otg_fsm *fsm, int on)
563 {
564 	struct ci_hdrc	*ci = container_of(fsm, struct ci_hdrc, fsm);
565 
566 	if (on)
567 		usb_gadget_vbus_connect(&ci->gadget);
568 	else
569 		usb_gadget_vbus_disconnect(&ci->gadget);
570 
571 	return 0;
572 }
573 
574 static struct otg_fsm_ops ci_otg_ops = {
575 	.drv_vbus = ci_otg_drv_vbus,
576 	.loc_conn = ci_otg_loc_conn,
577 	.loc_sof = ci_otg_loc_sof,
578 	.start_pulse = ci_otg_start_pulse,
579 	.add_timer = ci_otg_fsm_add_timer,
580 	.del_timer = ci_otg_fsm_del_timer,
581 	.start_host = ci_otg_start_host,
582 	.start_gadget = ci_otg_start_gadget,
583 };
584 
585 int ci_otg_fsm_work(struct ci_hdrc *ci)
586 {
587 	/*
588 	 * Don't do fsm transition for B device
589 	 * when there is no gadget class driver
590 	 */
591 	if (ci->fsm.id && !(ci->driver) &&
592 		ci->fsm.otg->state < OTG_STATE_A_IDLE)
593 		return 0;
594 
595 	pm_runtime_get_sync(ci->dev);
596 	if (otg_statemachine(&ci->fsm)) {
597 		if (ci->fsm.otg->state == OTG_STATE_A_IDLE) {
598 			/*
599 			 * Further state change for cases:
600 			 * a_idle to b_idle; or
601 			 * a_idle to a_wait_vrise due to ID change(1->0), so
602 			 * B-dev becomes A-dev can try to start new session
603 			 * consequently; or
604 			 * a_idle to a_wait_vrise when power up
605 			 */
606 			if ((ci->fsm.id) || (ci->id_event) ||
607 						(ci->fsm.power_up)) {
608 				ci_otg_queue_work(ci);
609 			} else {
610 				/* Enable data pulse irq */
611 				hw_write(ci, OP_PORTSC, PORTSC_W1C_BITS |
612 								PORTSC_PP, 0);
613 				hw_write_otgsc(ci, OTGSC_DPIS, OTGSC_DPIS);
614 				hw_write_otgsc(ci, OTGSC_DPIE, OTGSC_DPIE);
615 			}
616 			if (ci->id_event)
617 				ci->id_event = false;
618 		} else if (ci->fsm.otg->state == OTG_STATE_B_IDLE) {
619 			if (ci->fsm.b_sess_vld) {
620 				ci->fsm.power_up = 0;
621 				/*
622 				 * Further transite to b_periphearl state
623 				 * when register gadget driver with vbus on
624 				 */
625 				ci_otg_queue_work(ci);
626 			}
627 		} else if (ci->fsm.otg->state == OTG_STATE_A_HOST) {
628 			pm_runtime_mark_last_busy(ci->dev);
629 			pm_runtime_put_autosuspend(ci->dev);
630 			return 0;
631 		}
632 	}
633 	pm_runtime_put_sync(ci->dev);
634 	return 0;
635 }
636 
637 /*
638  * Update fsm variables in each state if catching expected interrupts,
639  * called by otg fsm isr.
640  */
641 static void ci_otg_fsm_event(struct ci_hdrc *ci)
642 {
643 	u32 intr_sts, otg_bsess_vld, port_conn;
644 	struct otg_fsm *fsm = &ci->fsm;
645 
646 	intr_sts = hw_read_intr_status(ci);
647 	otg_bsess_vld = hw_read_otgsc(ci, OTGSC_BSV);
648 	port_conn = hw_read(ci, OP_PORTSC, PORTSC_CCS);
649 
650 	switch (ci->fsm.otg->state) {
651 	case OTG_STATE_A_WAIT_BCON:
652 		if (port_conn) {
653 			fsm->b_conn = 1;
654 			fsm->a_bus_req = 1;
655 			ci_otg_queue_work(ci);
656 		}
657 		break;
658 	case OTG_STATE_B_IDLE:
659 		if (otg_bsess_vld && (intr_sts & USBi_PCI) && port_conn) {
660 			fsm->b_sess_vld = 1;
661 			ci_otg_queue_work(ci);
662 		}
663 		break;
664 	case OTG_STATE_B_PERIPHERAL:
665 		if ((intr_sts & USBi_SLI) && port_conn && otg_bsess_vld) {
666 			ci_otg_add_timer(ci, B_AIDL_BDIS);
667 		} else if (intr_sts & USBi_PCI) {
668 			ci_otg_del_timer(ci, B_AIDL_BDIS);
669 			if (fsm->a_bus_suspend == 1)
670 				fsm->a_bus_suspend = 0;
671 		}
672 		break;
673 	case OTG_STATE_B_HOST:
674 		if ((intr_sts & USBi_PCI) && !port_conn) {
675 			fsm->a_conn = 0;
676 			fsm->b_bus_req = 0;
677 			ci_otg_queue_work(ci);
678 		}
679 		break;
680 	case OTG_STATE_A_PERIPHERAL:
681 		if (intr_sts & USBi_SLI) {
682 			 fsm->b_bus_suspend = 1;
683 			/*
684 			 * Init a timer to know how long this suspend
685 			 * will continue, if time out, indicates B no longer
686 			 * wants to be host role
687 			 */
688 			 ci_otg_add_timer(ci, A_BIDL_ADIS);
689 		}
690 
691 		if (intr_sts & USBi_URI)
692 			ci_otg_del_timer(ci, A_BIDL_ADIS);
693 
694 		if (intr_sts & USBi_PCI) {
695 			if (fsm->b_bus_suspend == 1) {
696 				ci_otg_del_timer(ci, A_BIDL_ADIS);
697 				fsm->b_bus_suspend = 0;
698 			}
699 		}
700 		break;
701 	case OTG_STATE_A_SUSPEND:
702 		if ((intr_sts & USBi_PCI) && !port_conn) {
703 			fsm->b_conn = 0;
704 
705 			/* if gadget driver is binded */
706 			if (ci->driver) {
707 				/* A device to be peripheral mode */
708 				ci->gadget.is_a_peripheral = 1;
709 			}
710 			ci_otg_queue_work(ci);
711 		}
712 		break;
713 	case OTG_STATE_A_HOST:
714 		if ((intr_sts & USBi_PCI) && !port_conn) {
715 			fsm->b_conn = 0;
716 			ci_otg_queue_work(ci);
717 		}
718 		break;
719 	case OTG_STATE_B_WAIT_ACON:
720 		if ((intr_sts & USBi_PCI) && port_conn) {
721 			fsm->a_conn = 1;
722 			ci_otg_queue_work(ci);
723 		}
724 		break;
725 	default:
726 		break;
727 	}
728 }
729 
730 /*
731  * ci_otg_irq - otg fsm related irq handling
732  * and also update otg fsm variable by monitoring usb host and udc
733  * state change interrupts.
734  * @ci: ci_hdrc
735  */
736 irqreturn_t ci_otg_fsm_irq(struct ci_hdrc *ci)
737 {
738 	irqreturn_t retval =  IRQ_NONE;
739 	u32 otgsc, otg_int_src = 0;
740 	struct otg_fsm *fsm = &ci->fsm;
741 
742 	otgsc = hw_read_otgsc(ci, ~0);
743 	otg_int_src = otgsc & OTGSC_INT_STATUS_BITS & (otgsc >> 8);
744 	fsm->id = (otgsc & OTGSC_ID) ? 1 : 0;
745 
746 	if (otg_int_src) {
747 		if (otg_int_src & OTGSC_DPIS) {
748 			hw_write_otgsc(ci, OTGSC_DPIS, OTGSC_DPIS);
749 			fsm->a_srp_det = 1;
750 			fsm->a_bus_drop = 0;
751 		} else if (otg_int_src & OTGSC_IDIS) {
752 			hw_write_otgsc(ci, OTGSC_IDIS, OTGSC_IDIS);
753 			if (fsm->id == 0) {
754 				fsm->a_bus_drop = 0;
755 				fsm->a_bus_req = 1;
756 				ci->id_event = true;
757 			}
758 		} else if (otg_int_src & OTGSC_BSVIS) {
759 			hw_write_otgsc(ci, OTGSC_BSVIS, OTGSC_BSVIS);
760 			if (otgsc & OTGSC_BSV) {
761 				fsm->b_sess_vld = 1;
762 				ci_otg_del_timer(ci, B_SSEND_SRP);
763 				ci_otg_del_timer(ci, B_SRP_FAIL);
764 				fsm->b_ssend_srp = 0;
765 			} else {
766 				fsm->b_sess_vld = 0;
767 				if (fsm->id)
768 					ci_otg_add_timer(ci, B_SSEND_SRP);
769 			}
770 		} else if (otg_int_src & OTGSC_AVVIS) {
771 			hw_write_otgsc(ci, OTGSC_AVVIS, OTGSC_AVVIS);
772 			if (otgsc & OTGSC_AVV) {
773 				fsm->a_vbus_vld = 1;
774 			} else {
775 				fsm->a_vbus_vld = 0;
776 				fsm->b_conn = 0;
777 			}
778 		}
779 		ci_otg_queue_work(ci);
780 		return IRQ_HANDLED;
781 	}
782 
783 	ci_otg_fsm_event(ci);
784 
785 	return retval;
786 }
787 
788 void ci_hdrc_otg_fsm_start(struct ci_hdrc *ci)
789 {
790 	ci_otg_queue_work(ci);
791 }
792 
793 int ci_hdrc_otg_fsm_init(struct ci_hdrc *ci)
794 {
795 	int retval = 0;
796 
797 	if (ci->phy)
798 		ci->otg.phy = ci->phy;
799 	else
800 		ci->otg.usb_phy = ci->usb_phy;
801 
802 	ci->otg.gadget = &ci->gadget;
803 	ci->fsm.otg = &ci->otg;
804 	ci->fsm.power_up = 1;
805 	ci->fsm.id = hw_read_otgsc(ci, OTGSC_ID) ? 1 : 0;
806 	ci->fsm.otg->state = OTG_STATE_UNDEFINED;
807 	ci->fsm.ops = &ci_otg_ops;
808 	ci->gadget.hnp_polling_support = 1;
809 	ci->fsm.host_req_flag = devm_kzalloc(ci->dev, 1, GFP_KERNEL);
810 	if (!ci->fsm.host_req_flag)
811 		return -ENOMEM;
812 
813 	mutex_init(&ci->fsm.lock);
814 
815 	retval = ci_otg_init_timers(ci);
816 	if (retval) {
817 		dev_err(ci->dev, "Couldn't init OTG timers\n");
818 		return retval;
819 	}
820 	ci->enabled_otg_timer_bits = 0;
821 	ci->next_otg_timer = NUM_OTG_FSM_TIMERS;
822 
823 	retval = sysfs_create_group(&ci->dev->kobj, &inputs_attr_group);
824 	if (retval < 0) {
825 		dev_dbg(ci->dev,
826 			"Can't register sysfs attr group: %d\n", retval);
827 		return retval;
828 	}
829 
830 	/* Enable A vbus valid irq */
831 	hw_write_otgsc(ci, OTGSC_AVVIE, OTGSC_AVVIE);
832 
833 	if (ci->fsm.id) {
834 		ci->fsm.b_ssend_srp =
835 			hw_read_otgsc(ci, OTGSC_BSV) ? 0 : 1;
836 		ci->fsm.b_sess_vld =
837 			hw_read_otgsc(ci, OTGSC_BSV) ? 1 : 0;
838 		/* Enable BSV irq */
839 		hw_write_otgsc(ci, OTGSC_BSVIE, OTGSC_BSVIE);
840 	}
841 
842 	return 0;
843 }
844 
845 void ci_hdrc_otg_fsm_remove(struct ci_hdrc *ci)
846 {
847 	sysfs_remove_group(&ci->dev->kobj, &inputs_attr_group);
848 }
849