xref: /openbmc/linux/drivers/usb/chipidea/otg_fsm.c (revision fb574682)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * otg_fsm.c - ChipIdea USB IP core OTG FSM driver
4  *
5  * Copyright (C) 2014 Freescale Semiconductor, Inc.
6  *
7  * Author: Jun Li
8  */
9 
10 /*
11  * This file mainly handles OTG fsm, it includes OTG fsm operations
12  * for HNP and SRP.
13  *
14  * TODO List
15  * - ADP
16  * - OTG test device
17  */
18 
19 #include <linux/usb/otg.h>
20 #include <linux/usb/gadget.h>
21 #include <linux/usb/hcd.h>
22 #include <linux/usb/chipidea.h>
23 #include <linux/regulator/consumer.h>
24 
25 #include "ci.h"
26 #include "bits.h"
27 #include "otg.h"
28 #include "otg_fsm.h"
29 
30 /* Add for otg: interact with user space app */
31 static ssize_t
32 a_bus_req_show(struct device *dev, struct device_attribute *attr, char *buf)
33 {
34 	char		*next;
35 	unsigned	size, t;
36 	struct ci_hdrc	*ci = dev_get_drvdata(dev);
37 
38 	next = buf;
39 	size = PAGE_SIZE;
40 	t = scnprintf(next, size, "%d\n", ci->fsm.a_bus_req);
41 	size -= t;
42 	next += t;
43 
44 	return PAGE_SIZE - size;
45 }
46 
47 static ssize_t
48 a_bus_req_store(struct device *dev, struct device_attribute *attr,
49 					const char *buf, size_t count)
50 {
51 	struct ci_hdrc *ci = dev_get_drvdata(dev);
52 
53 	if (count > 2)
54 		return -1;
55 
56 	mutex_lock(&ci->fsm.lock);
57 	if (buf[0] == '0') {
58 		ci->fsm.a_bus_req = 0;
59 	} else if (buf[0] == '1') {
60 		/* If a_bus_drop is TRUE, a_bus_req can't be set */
61 		if (ci->fsm.a_bus_drop) {
62 			mutex_unlock(&ci->fsm.lock);
63 			return count;
64 		}
65 		ci->fsm.a_bus_req = 1;
66 		if (ci->fsm.otg->state == OTG_STATE_A_PERIPHERAL) {
67 			ci->gadget.host_request_flag = 1;
68 			mutex_unlock(&ci->fsm.lock);
69 			return count;
70 		}
71 	}
72 
73 	ci_otg_queue_work(ci);
74 	mutex_unlock(&ci->fsm.lock);
75 
76 	return count;
77 }
78 static DEVICE_ATTR_RW(a_bus_req);
79 
80 static ssize_t
81 a_bus_drop_show(struct device *dev, struct device_attribute *attr, char *buf)
82 {
83 	char		*next;
84 	unsigned	size, t;
85 	struct ci_hdrc	*ci = dev_get_drvdata(dev);
86 
87 	next = buf;
88 	size = PAGE_SIZE;
89 	t = scnprintf(next, size, "%d\n", ci->fsm.a_bus_drop);
90 	size -= t;
91 	next += t;
92 
93 	return PAGE_SIZE - size;
94 }
95 
96 static ssize_t
97 a_bus_drop_store(struct device *dev, struct device_attribute *attr,
98 					const char *buf, size_t count)
99 {
100 	struct ci_hdrc	*ci = dev_get_drvdata(dev);
101 
102 	if (count > 2)
103 		return -1;
104 
105 	mutex_lock(&ci->fsm.lock);
106 	if (buf[0] == '0') {
107 		ci->fsm.a_bus_drop = 0;
108 	} else if (buf[0] == '1') {
109 		ci->fsm.a_bus_drop = 1;
110 		ci->fsm.a_bus_req = 0;
111 	}
112 
113 	ci_otg_queue_work(ci);
114 	mutex_unlock(&ci->fsm.lock);
115 
116 	return count;
117 }
118 static DEVICE_ATTR_RW(a_bus_drop);
119 
120 static ssize_t
121 b_bus_req_show(struct device *dev, struct device_attribute *attr, char *buf)
122 {
123 	char		*next;
124 	unsigned	size, t;
125 	struct ci_hdrc	*ci = dev_get_drvdata(dev);
126 
127 	next = buf;
128 	size = PAGE_SIZE;
129 	t = scnprintf(next, size, "%d\n", ci->fsm.b_bus_req);
130 	size -= t;
131 	next += t;
132 
133 	return PAGE_SIZE - size;
134 }
135 
136 static ssize_t
137 b_bus_req_store(struct device *dev, struct device_attribute *attr,
138 					const char *buf, size_t count)
139 {
140 	struct ci_hdrc	*ci = dev_get_drvdata(dev);
141 
142 	if (count > 2)
143 		return -1;
144 
145 	mutex_lock(&ci->fsm.lock);
146 	if (buf[0] == '0')
147 		ci->fsm.b_bus_req = 0;
148 	else if (buf[0] == '1') {
149 		ci->fsm.b_bus_req = 1;
150 		if (ci->fsm.otg->state == OTG_STATE_B_PERIPHERAL) {
151 			ci->gadget.host_request_flag = 1;
152 			mutex_unlock(&ci->fsm.lock);
153 			return count;
154 		}
155 	}
156 
157 	ci_otg_queue_work(ci);
158 	mutex_unlock(&ci->fsm.lock);
159 
160 	return count;
161 }
162 static DEVICE_ATTR_RW(b_bus_req);
163 
164 static ssize_t
165 a_clr_err_store(struct device *dev, struct device_attribute *attr,
166 					const char *buf, size_t count)
167 {
168 	struct ci_hdrc	*ci = dev_get_drvdata(dev);
169 
170 	if (count > 2)
171 		return -1;
172 
173 	mutex_lock(&ci->fsm.lock);
174 	if (buf[0] == '1')
175 		ci->fsm.a_clr_err = 1;
176 
177 	ci_otg_queue_work(ci);
178 	mutex_unlock(&ci->fsm.lock);
179 
180 	return count;
181 }
182 static DEVICE_ATTR_WO(a_clr_err);
183 
184 static struct attribute *inputs_attrs[] = {
185 	&dev_attr_a_bus_req.attr,
186 	&dev_attr_a_bus_drop.attr,
187 	&dev_attr_b_bus_req.attr,
188 	&dev_attr_a_clr_err.attr,
189 	NULL,
190 };
191 
192 static const struct attribute_group inputs_attr_group = {
193 	.name = "inputs",
194 	.attrs = inputs_attrs,
195 };
196 
197 /*
198  * Keep this list in the same order as timers indexed
199  * by enum otg_fsm_timer in include/linux/usb/otg-fsm.h
200  */
201 static unsigned otg_timer_ms[] = {
202 	TA_WAIT_VRISE,
203 	TA_WAIT_VFALL,
204 	TA_WAIT_BCON,
205 	TA_AIDL_BDIS,
206 	TB_ASE0_BRST,
207 	TA_BIDL_ADIS,
208 	TB_AIDL_BDIS,
209 	TB_SE0_SRP,
210 	TB_SRP_FAIL,
211 	0,
212 	TB_DATA_PLS,
213 	TB_SSEND_SRP,
214 };
215 
216 /*
217  * Add timer to active timer list
218  */
219 static void ci_otg_add_timer(struct ci_hdrc *ci, enum otg_fsm_timer t)
220 {
221 	unsigned long flags, timer_sec, timer_nsec;
222 
223 	if (t >= NUM_OTG_FSM_TIMERS)
224 		return;
225 
226 	spin_lock_irqsave(&ci->lock, flags);
227 	timer_sec = otg_timer_ms[t] / MSEC_PER_SEC;
228 	timer_nsec = (otg_timer_ms[t] % MSEC_PER_SEC) * NSEC_PER_MSEC;
229 	ci->hr_timeouts[t] = ktime_add(ktime_get(),
230 				ktime_set(timer_sec, timer_nsec));
231 	ci->enabled_otg_timer_bits |= (1 << t);
232 	if ((ci->next_otg_timer == NUM_OTG_FSM_TIMERS) ||
233 			ktime_after(ci->hr_timeouts[ci->next_otg_timer],
234 						ci->hr_timeouts[t])) {
235 			ci->next_otg_timer = t;
236 			hrtimer_start_range_ns(&ci->otg_fsm_hrtimer,
237 					ci->hr_timeouts[t], NSEC_PER_MSEC,
238 							HRTIMER_MODE_ABS);
239 	}
240 	spin_unlock_irqrestore(&ci->lock, flags);
241 }
242 
243 /*
244  * Remove timer from active timer list
245  */
246 static void ci_otg_del_timer(struct ci_hdrc *ci, enum otg_fsm_timer t)
247 {
248 	unsigned long flags, enabled_timer_bits;
249 	enum otg_fsm_timer cur_timer, next_timer = NUM_OTG_FSM_TIMERS;
250 
251 	if ((t >= NUM_OTG_FSM_TIMERS) ||
252 			!(ci->enabled_otg_timer_bits & (1 << t)))
253 		return;
254 
255 	spin_lock_irqsave(&ci->lock, flags);
256 	ci->enabled_otg_timer_bits &= ~(1 << t);
257 	if (ci->next_otg_timer == t) {
258 		if (ci->enabled_otg_timer_bits == 0) {
259 			/* No enabled timers after delete it */
260 			hrtimer_cancel(&ci->otg_fsm_hrtimer);
261 			ci->next_otg_timer = NUM_OTG_FSM_TIMERS;
262 		} else {
263 			/* Find the next timer */
264 			enabled_timer_bits = ci->enabled_otg_timer_bits;
265 			for_each_set_bit(cur_timer, &enabled_timer_bits,
266 							NUM_OTG_FSM_TIMERS) {
267 				if ((next_timer == NUM_OTG_FSM_TIMERS) ||
268 					ktime_before(ci->hr_timeouts[next_timer],
269 					 ci->hr_timeouts[cur_timer]))
270 					next_timer = cur_timer;
271 			}
272 		}
273 	}
274 	if (next_timer != NUM_OTG_FSM_TIMERS) {
275 		ci->next_otg_timer = next_timer;
276 		hrtimer_start_range_ns(&ci->otg_fsm_hrtimer,
277 			ci->hr_timeouts[next_timer], NSEC_PER_MSEC,
278 							HRTIMER_MODE_ABS);
279 	}
280 	spin_unlock_irqrestore(&ci->lock, flags);
281 }
282 
283 /* OTG FSM timer handlers */
284 static int a_wait_vrise_tmout(struct ci_hdrc *ci)
285 {
286 	ci->fsm.a_wait_vrise_tmout = 1;
287 	return 0;
288 }
289 
290 static int a_wait_vfall_tmout(struct ci_hdrc *ci)
291 {
292 	ci->fsm.a_wait_vfall_tmout = 1;
293 	return 0;
294 }
295 
296 static int a_wait_bcon_tmout(struct ci_hdrc *ci)
297 {
298 	ci->fsm.a_wait_bcon_tmout = 1;
299 	return 0;
300 }
301 
302 static int a_aidl_bdis_tmout(struct ci_hdrc *ci)
303 {
304 	ci->fsm.a_aidl_bdis_tmout = 1;
305 	return 0;
306 }
307 
308 static int b_ase0_brst_tmout(struct ci_hdrc *ci)
309 {
310 	ci->fsm.b_ase0_brst_tmout = 1;
311 	return 0;
312 }
313 
314 static int a_bidl_adis_tmout(struct ci_hdrc *ci)
315 {
316 	ci->fsm.a_bidl_adis_tmout = 1;
317 	return 0;
318 }
319 
320 static int b_aidl_bdis_tmout(struct ci_hdrc *ci)
321 {
322 	ci->fsm.a_bus_suspend = 1;
323 	return 0;
324 }
325 
326 static int b_se0_srp_tmout(struct ci_hdrc *ci)
327 {
328 	ci->fsm.b_se0_srp = 1;
329 	return 0;
330 }
331 
332 static int b_srp_fail_tmout(struct ci_hdrc *ci)
333 {
334 	ci->fsm.b_srp_done = 1;
335 	return 1;
336 }
337 
338 static int b_data_pls_tmout(struct ci_hdrc *ci)
339 {
340 	ci->fsm.b_srp_done = 1;
341 	ci->fsm.b_bus_req = 0;
342 	if (ci->fsm.power_up)
343 		ci->fsm.power_up = 0;
344 	hw_write_otgsc(ci, OTGSC_HABA, 0);
345 	pm_runtime_put(ci->dev);
346 	return 0;
347 }
348 
349 static int b_ssend_srp_tmout(struct ci_hdrc *ci)
350 {
351 	ci->fsm.b_ssend_srp = 1;
352 	/* only vbus fall below B_sess_vld in b_idle state */
353 	if (ci->fsm.otg->state == OTG_STATE_B_IDLE)
354 		return 0;
355 	else
356 		return 1;
357 }
358 
359 /*
360  * Keep this list in the same order as timers indexed
361  * by enum otg_fsm_timer in include/linux/usb/otg-fsm.h
362  */
363 static int (*otg_timer_handlers[])(struct ci_hdrc *) = {
364 	a_wait_vrise_tmout,	/* A_WAIT_VRISE */
365 	a_wait_vfall_tmout,	/* A_WAIT_VFALL */
366 	a_wait_bcon_tmout,	/* A_WAIT_BCON */
367 	a_aidl_bdis_tmout,	/* A_AIDL_BDIS */
368 	b_ase0_brst_tmout,	/* B_ASE0_BRST */
369 	a_bidl_adis_tmout,	/* A_BIDL_ADIS */
370 	b_aidl_bdis_tmout,	/* B_AIDL_BDIS */
371 	b_se0_srp_tmout,	/* B_SE0_SRP */
372 	b_srp_fail_tmout,	/* B_SRP_FAIL */
373 	NULL,			/* A_WAIT_ENUM */
374 	b_data_pls_tmout,	/* B_DATA_PLS */
375 	b_ssend_srp_tmout,	/* B_SSEND_SRP */
376 };
377 
378 /*
379  * Enable the next nearest enabled timer if have
380  */
381 static enum hrtimer_restart ci_otg_hrtimer_func(struct hrtimer *t)
382 {
383 	struct ci_hdrc *ci = container_of(t, struct ci_hdrc, otg_fsm_hrtimer);
384 	ktime_t	now, *timeout;
385 	unsigned long   enabled_timer_bits;
386 	unsigned long   flags;
387 	enum otg_fsm_timer cur_timer, next_timer = NUM_OTG_FSM_TIMERS;
388 	int ret = -EINVAL;
389 
390 	spin_lock_irqsave(&ci->lock, flags);
391 	enabled_timer_bits = ci->enabled_otg_timer_bits;
392 	ci->next_otg_timer = NUM_OTG_FSM_TIMERS;
393 
394 	now = ktime_get();
395 	for_each_set_bit(cur_timer, &enabled_timer_bits, NUM_OTG_FSM_TIMERS) {
396 		if (ktime_compare(now, ci->hr_timeouts[cur_timer]) >= 0) {
397 			ci->enabled_otg_timer_bits &= ~(1 << cur_timer);
398 			if (otg_timer_handlers[cur_timer])
399 				ret = otg_timer_handlers[cur_timer](ci);
400 		} else {
401 			if ((next_timer == NUM_OTG_FSM_TIMERS) ||
402 				ktime_before(ci->hr_timeouts[cur_timer],
403 					ci->hr_timeouts[next_timer]))
404 				next_timer = cur_timer;
405 		}
406 	}
407 	/* Enable the next nearest timer */
408 	if (next_timer < NUM_OTG_FSM_TIMERS) {
409 		timeout = &ci->hr_timeouts[next_timer];
410 		hrtimer_start_range_ns(&ci->otg_fsm_hrtimer, *timeout,
411 					NSEC_PER_MSEC, HRTIMER_MODE_ABS);
412 		ci->next_otg_timer = next_timer;
413 	}
414 	spin_unlock_irqrestore(&ci->lock, flags);
415 
416 	if (!ret)
417 		ci_otg_queue_work(ci);
418 
419 	return HRTIMER_NORESTART;
420 }
421 
422 /* Initialize timers */
423 static int ci_otg_init_timers(struct ci_hdrc *ci)
424 {
425 	hrtimer_init(&ci->otg_fsm_hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
426 	ci->otg_fsm_hrtimer.function = ci_otg_hrtimer_func;
427 
428 	return 0;
429 }
430 
431 /* -------------------------------------------------------------*/
432 /* Operations that will be called from OTG Finite State Machine */
433 /* -------------------------------------------------------------*/
434 static void ci_otg_fsm_add_timer(struct otg_fsm *fsm, enum otg_fsm_timer t)
435 {
436 	struct ci_hdrc	*ci = container_of(fsm, struct ci_hdrc, fsm);
437 
438 	if (t < NUM_OTG_FSM_TIMERS)
439 		ci_otg_add_timer(ci, t);
440 	return;
441 }
442 
443 static void ci_otg_fsm_del_timer(struct otg_fsm *fsm, enum otg_fsm_timer t)
444 {
445 	struct ci_hdrc	*ci = container_of(fsm, struct ci_hdrc, fsm);
446 
447 	if (t < NUM_OTG_FSM_TIMERS)
448 		ci_otg_del_timer(ci, t);
449 	return;
450 }
451 
452 /*
453  * A-device drive vbus: turn on vbus regulator and enable port power
454  * Data pulse irq should be disabled while vbus is on.
455  */
456 static void ci_otg_drv_vbus(struct otg_fsm *fsm, int on)
457 {
458 	int ret;
459 	struct ci_hdrc	*ci = container_of(fsm, struct ci_hdrc, fsm);
460 
461 	if (on) {
462 		/* Enable power power */
463 		hw_write(ci, OP_PORTSC, PORTSC_W1C_BITS | PORTSC_PP,
464 							PORTSC_PP);
465 		if (ci->platdata->reg_vbus) {
466 			ret = regulator_enable(ci->platdata->reg_vbus);
467 			if (ret) {
468 				dev_err(ci->dev,
469 				"Failed to enable vbus regulator, ret=%d\n",
470 				ret);
471 				return;
472 			}
473 		}
474 		/* Disable data pulse irq */
475 		hw_write_otgsc(ci, OTGSC_DPIE, 0);
476 
477 		fsm->a_srp_det = 0;
478 		fsm->power_up = 0;
479 	} else {
480 		if (ci->platdata->reg_vbus)
481 			regulator_disable(ci->platdata->reg_vbus);
482 
483 		fsm->a_bus_drop = 1;
484 		fsm->a_bus_req = 0;
485 	}
486 }
487 
488 /*
489  * Control data line by Run Stop bit.
490  */
491 static void ci_otg_loc_conn(struct otg_fsm *fsm, int on)
492 {
493 	struct ci_hdrc	*ci = container_of(fsm, struct ci_hdrc, fsm);
494 
495 	if (on)
496 		hw_write(ci, OP_USBCMD, USBCMD_RS, USBCMD_RS);
497 	else
498 		hw_write(ci, OP_USBCMD, USBCMD_RS, 0);
499 }
500 
501 /*
502  * Generate SOF by host.
503  * In host mode, controller will automatically send SOF.
504  * Suspend will block the data on the port.
505  *
506  * This is controlled through usbcore by usb autosuspend,
507  * so the usb device class driver need support autosuspend,
508  * otherwise the bus suspend will not happen.
509  */
510 static void ci_otg_loc_sof(struct otg_fsm *fsm, int on)
511 {
512 	struct usb_device *udev;
513 
514 	if (!fsm->otg->host)
515 		return;
516 
517 	udev = usb_hub_find_child(fsm->otg->host->root_hub, 1);
518 	if (!udev)
519 		return;
520 
521 	if (on) {
522 		usb_disable_autosuspend(udev);
523 	} else {
524 		pm_runtime_set_autosuspend_delay(&udev->dev, 0);
525 		usb_enable_autosuspend(udev);
526 	}
527 }
528 
529 /*
530  * Start SRP pulsing by data-line pulsing,
531  * no v-bus pulsing followed
532  */
533 static void ci_otg_start_pulse(struct otg_fsm *fsm)
534 {
535 	struct ci_hdrc	*ci = container_of(fsm, struct ci_hdrc, fsm);
536 
537 	/* Hardware Assistant Data pulse */
538 	hw_write_otgsc(ci, OTGSC_HADP, OTGSC_HADP);
539 
540 	pm_runtime_get(ci->dev);
541 	ci_otg_add_timer(ci, B_DATA_PLS);
542 }
543 
544 static int ci_otg_start_host(struct otg_fsm *fsm, int on)
545 {
546 	struct ci_hdrc	*ci = container_of(fsm, struct ci_hdrc, fsm);
547 
548 	if (on) {
549 		ci_role_stop(ci);
550 		ci_role_start(ci, CI_ROLE_HOST);
551 	} else {
552 		ci_role_stop(ci);
553 		ci_role_start(ci, CI_ROLE_GADGET);
554 	}
555 	return 0;
556 }
557 
558 static int ci_otg_start_gadget(struct otg_fsm *fsm, int on)
559 {
560 	struct ci_hdrc	*ci = container_of(fsm, struct ci_hdrc, fsm);
561 
562 	if (on)
563 		usb_gadget_vbus_connect(&ci->gadget);
564 	else
565 		usb_gadget_vbus_disconnect(&ci->gadget);
566 
567 	return 0;
568 }
569 
570 static struct otg_fsm_ops ci_otg_ops = {
571 	.drv_vbus = ci_otg_drv_vbus,
572 	.loc_conn = ci_otg_loc_conn,
573 	.loc_sof = ci_otg_loc_sof,
574 	.start_pulse = ci_otg_start_pulse,
575 	.add_timer = ci_otg_fsm_add_timer,
576 	.del_timer = ci_otg_fsm_del_timer,
577 	.start_host = ci_otg_start_host,
578 	.start_gadget = ci_otg_start_gadget,
579 };
580 
581 int ci_otg_fsm_work(struct ci_hdrc *ci)
582 {
583 	/*
584 	 * Don't do fsm transition for B device
585 	 * when there is no gadget class driver
586 	 */
587 	if (ci->fsm.id && !(ci->driver) &&
588 		ci->fsm.otg->state < OTG_STATE_A_IDLE)
589 		return 0;
590 
591 	pm_runtime_get_sync(ci->dev);
592 	if (otg_statemachine(&ci->fsm)) {
593 		if (ci->fsm.otg->state == OTG_STATE_A_IDLE) {
594 			/*
595 			 * Further state change for cases:
596 			 * a_idle to b_idle; or
597 			 * a_idle to a_wait_vrise due to ID change(1->0), so
598 			 * B-dev becomes A-dev can try to start new session
599 			 * consequently; or
600 			 * a_idle to a_wait_vrise when power up
601 			 */
602 			if ((ci->fsm.id) || (ci->id_event) ||
603 						(ci->fsm.power_up)) {
604 				ci_otg_queue_work(ci);
605 			} else {
606 				/* Enable data pulse irq */
607 				hw_write(ci, OP_PORTSC, PORTSC_W1C_BITS |
608 								PORTSC_PP, 0);
609 				hw_write_otgsc(ci, OTGSC_DPIS, OTGSC_DPIS);
610 				hw_write_otgsc(ci, OTGSC_DPIE, OTGSC_DPIE);
611 			}
612 			if (ci->id_event)
613 				ci->id_event = false;
614 		} else if (ci->fsm.otg->state == OTG_STATE_B_IDLE) {
615 			if (ci->fsm.b_sess_vld) {
616 				ci->fsm.power_up = 0;
617 				/*
618 				 * Further transite to b_periphearl state
619 				 * when register gadget driver with vbus on
620 				 */
621 				ci_otg_queue_work(ci);
622 			}
623 		} else if (ci->fsm.otg->state == OTG_STATE_A_HOST) {
624 			pm_runtime_mark_last_busy(ci->dev);
625 			pm_runtime_put_autosuspend(ci->dev);
626 			return 0;
627 		}
628 	}
629 	pm_runtime_put_sync(ci->dev);
630 	return 0;
631 }
632 
633 /*
634  * Update fsm variables in each state if catching expected interrupts,
635  * called by otg fsm isr.
636  */
637 static void ci_otg_fsm_event(struct ci_hdrc *ci)
638 {
639 	u32 intr_sts, otg_bsess_vld, port_conn;
640 	struct otg_fsm *fsm = &ci->fsm;
641 
642 	intr_sts = hw_read_intr_status(ci);
643 	otg_bsess_vld = hw_read_otgsc(ci, OTGSC_BSV);
644 	port_conn = hw_read(ci, OP_PORTSC, PORTSC_CCS);
645 
646 	switch (ci->fsm.otg->state) {
647 	case OTG_STATE_A_WAIT_BCON:
648 		if (port_conn) {
649 			fsm->b_conn = 1;
650 			fsm->a_bus_req = 1;
651 			ci_otg_queue_work(ci);
652 		}
653 		break;
654 	case OTG_STATE_B_IDLE:
655 		if (otg_bsess_vld && (intr_sts & USBi_PCI) && port_conn) {
656 			fsm->b_sess_vld = 1;
657 			ci_otg_queue_work(ci);
658 		}
659 		break;
660 	case OTG_STATE_B_PERIPHERAL:
661 		if ((intr_sts & USBi_SLI) && port_conn && otg_bsess_vld) {
662 			ci_otg_add_timer(ci, B_AIDL_BDIS);
663 		} else if (intr_sts & USBi_PCI) {
664 			ci_otg_del_timer(ci, B_AIDL_BDIS);
665 			if (fsm->a_bus_suspend == 1)
666 				fsm->a_bus_suspend = 0;
667 		}
668 		break;
669 	case OTG_STATE_B_HOST:
670 		if ((intr_sts & USBi_PCI) && !port_conn) {
671 			fsm->a_conn = 0;
672 			fsm->b_bus_req = 0;
673 			ci_otg_queue_work(ci);
674 		}
675 		break;
676 	case OTG_STATE_A_PERIPHERAL:
677 		if (intr_sts & USBi_SLI) {
678 			 fsm->b_bus_suspend = 1;
679 			/*
680 			 * Init a timer to know how long this suspend
681 			 * will continue, if time out, indicates B no longer
682 			 * wants to be host role
683 			 */
684 			 ci_otg_add_timer(ci, A_BIDL_ADIS);
685 		}
686 
687 		if (intr_sts & USBi_URI)
688 			ci_otg_del_timer(ci, A_BIDL_ADIS);
689 
690 		if (intr_sts & USBi_PCI) {
691 			if (fsm->b_bus_suspend == 1) {
692 				ci_otg_del_timer(ci, A_BIDL_ADIS);
693 				fsm->b_bus_suspend = 0;
694 			}
695 		}
696 		break;
697 	case OTG_STATE_A_SUSPEND:
698 		if ((intr_sts & USBi_PCI) && !port_conn) {
699 			fsm->b_conn = 0;
700 
701 			/* if gadget driver is binded */
702 			if (ci->driver) {
703 				/* A device to be peripheral mode */
704 				ci->gadget.is_a_peripheral = 1;
705 			}
706 			ci_otg_queue_work(ci);
707 		}
708 		break;
709 	case OTG_STATE_A_HOST:
710 		if ((intr_sts & USBi_PCI) && !port_conn) {
711 			fsm->b_conn = 0;
712 			ci_otg_queue_work(ci);
713 		}
714 		break;
715 	case OTG_STATE_B_WAIT_ACON:
716 		if ((intr_sts & USBi_PCI) && port_conn) {
717 			fsm->a_conn = 1;
718 			ci_otg_queue_work(ci);
719 		}
720 		break;
721 	default:
722 		break;
723 	}
724 }
725 
726 /*
727  * ci_otg_irq - otg fsm related irq handling
728  * and also update otg fsm variable by monitoring usb host and udc
729  * state change interrupts.
730  * @ci: ci_hdrc
731  */
732 irqreturn_t ci_otg_fsm_irq(struct ci_hdrc *ci)
733 {
734 	irqreturn_t retval =  IRQ_NONE;
735 	u32 otgsc, otg_int_src = 0;
736 	struct otg_fsm *fsm = &ci->fsm;
737 
738 	otgsc = hw_read_otgsc(ci, ~0);
739 	otg_int_src = otgsc & OTGSC_INT_STATUS_BITS & (otgsc >> 8);
740 	fsm->id = (otgsc & OTGSC_ID) ? 1 : 0;
741 
742 	if (otg_int_src) {
743 		if (otg_int_src & OTGSC_DPIS) {
744 			hw_write_otgsc(ci, OTGSC_DPIS, OTGSC_DPIS);
745 			fsm->a_srp_det = 1;
746 			fsm->a_bus_drop = 0;
747 		} else if (otg_int_src & OTGSC_IDIS) {
748 			hw_write_otgsc(ci, OTGSC_IDIS, OTGSC_IDIS);
749 			if (fsm->id == 0) {
750 				fsm->a_bus_drop = 0;
751 				fsm->a_bus_req = 1;
752 				ci->id_event = true;
753 			}
754 		} else if (otg_int_src & OTGSC_BSVIS) {
755 			hw_write_otgsc(ci, OTGSC_BSVIS, OTGSC_BSVIS);
756 			if (otgsc & OTGSC_BSV) {
757 				fsm->b_sess_vld = 1;
758 				ci_otg_del_timer(ci, B_SSEND_SRP);
759 				ci_otg_del_timer(ci, B_SRP_FAIL);
760 				fsm->b_ssend_srp = 0;
761 			} else {
762 				fsm->b_sess_vld = 0;
763 				if (fsm->id)
764 					ci_otg_add_timer(ci, B_SSEND_SRP);
765 			}
766 		} else if (otg_int_src & OTGSC_AVVIS) {
767 			hw_write_otgsc(ci, OTGSC_AVVIS, OTGSC_AVVIS);
768 			if (otgsc & OTGSC_AVV) {
769 				fsm->a_vbus_vld = 1;
770 			} else {
771 				fsm->a_vbus_vld = 0;
772 				fsm->b_conn = 0;
773 			}
774 		}
775 		ci_otg_queue_work(ci);
776 		return IRQ_HANDLED;
777 	}
778 
779 	ci_otg_fsm_event(ci);
780 
781 	return retval;
782 }
783 
784 void ci_hdrc_otg_fsm_start(struct ci_hdrc *ci)
785 {
786 	ci_otg_queue_work(ci);
787 }
788 
789 int ci_hdrc_otg_fsm_init(struct ci_hdrc *ci)
790 {
791 	int retval = 0;
792 
793 	if (ci->phy)
794 		ci->otg.phy = ci->phy;
795 	else
796 		ci->otg.usb_phy = ci->usb_phy;
797 
798 	ci->otg.gadget = &ci->gadget;
799 	ci->fsm.otg = &ci->otg;
800 	ci->fsm.power_up = 1;
801 	ci->fsm.id = hw_read_otgsc(ci, OTGSC_ID) ? 1 : 0;
802 	ci->fsm.otg->state = OTG_STATE_UNDEFINED;
803 	ci->fsm.ops = &ci_otg_ops;
804 	ci->gadget.hnp_polling_support = 1;
805 	ci->fsm.host_req_flag = devm_kzalloc(ci->dev, 1, GFP_KERNEL);
806 	if (!ci->fsm.host_req_flag)
807 		return -ENOMEM;
808 
809 	mutex_init(&ci->fsm.lock);
810 
811 	retval = ci_otg_init_timers(ci);
812 	if (retval) {
813 		dev_err(ci->dev, "Couldn't init OTG timers\n");
814 		return retval;
815 	}
816 	ci->enabled_otg_timer_bits = 0;
817 	ci->next_otg_timer = NUM_OTG_FSM_TIMERS;
818 
819 	retval = sysfs_create_group(&ci->dev->kobj, &inputs_attr_group);
820 	if (retval < 0) {
821 		dev_dbg(ci->dev,
822 			"Can't register sysfs attr group: %d\n", retval);
823 		return retval;
824 	}
825 
826 	/* Enable A vbus valid irq */
827 	hw_write_otgsc(ci, OTGSC_AVVIE, OTGSC_AVVIE);
828 
829 	if (ci->fsm.id) {
830 		ci->fsm.b_ssend_srp =
831 			hw_read_otgsc(ci, OTGSC_BSV) ? 0 : 1;
832 		ci->fsm.b_sess_vld =
833 			hw_read_otgsc(ci, OTGSC_BSV) ? 1 : 0;
834 		/* Enable BSV irq */
835 		hw_write_otgsc(ci, OTGSC_BSVIE, OTGSC_BSVIE);
836 	}
837 
838 	return 0;
839 }
840 
841 void ci_hdrc_otg_fsm_remove(struct ci_hdrc *ci)
842 {
843 	sysfs_remove_group(&ci->dev->kobj, &inputs_attr_group);
844 }
845