xref: /linux/drivers/usb/chipidea/otg_fsm.c (revision 29583dfcd2dd72c766422bd05c16f06c6b1fb356)
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 */
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 
475 		if (ci->platdata->flags & CI_HDRC_PHY_VBUS_CONTROL)
476 			usb_phy_vbus_on(ci->usb_phy);
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 		if (ci->platdata->flags & CI_HDRC_PHY_VBUS_CONTROL)
488 			usb_phy_vbus_off(ci->usb_phy);
489 
490 		fsm->a_bus_drop = 1;
491 		fsm->a_bus_req = 0;
492 	}
493 }
494 
495 /*
496  * Control data line by Run Stop bit.
497  */
498 static void ci_otg_loc_conn(struct otg_fsm *fsm, int on)
499 {
500 	struct ci_hdrc	*ci = container_of(fsm, struct ci_hdrc, fsm);
501 
502 	if (on)
503 		hw_write(ci, OP_USBCMD, USBCMD_RS, USBCMD_RS);
504 	else
505 		hw_write(ci, OP_USBCMD, USBCMD_RS, 0);
506 }
507 
508 /*
509  * Generate SOF by host.
510  * In host mode, controller will automatically send SOF.
511  * Suspend will block the data on the port.
512  *
513  * This is controlled through usbcore by usb autosuspend,
514  * so the usb device class driver need support autosuspend,
515  * otherwise the bus suspend will not happen.
516  */
517 static void ci_otg_loc_sof(struct otg_fsm *fsm, int on)
518 {
519 	struct usb_device *udev;
520 
521 	if (!fsm->otg->host)
522 		return;
523 
524 	udev = usb_hub_find_child(fsm->otg->host->root_hub, 1);
525 	if (!udev)
526 		return;
527 
528 	if (on) {
529 		usb_disable_autosuspend(udev);
530 	} else {
531 		pm_runtime_set_autosuspend_delay(&udev->dev, 0);
532 		usb_enable_autosuspend(udev);
533 	}
534 }
535 
536 /*
537  * Start SRP pulsing by data-line pulsing,
538  * no v-bus pulsing followed
539  */
540 static void ci_otg_start_pulse(struct otg_fsm *fsm)
541 {
542 	struct ci_hdrc	*ci = container_of(fsm, struct ci_hdrc, fsm);
543 
544 	/* Hardware Assistant Data pulse */
545 	hw_write_otgsc(ci, OTGSC_HADP, OTGSC_HADP);
546 
547 	pm_runtime_get(ci->dev);
548 	ci_otg_add_timer(ci, B_DATA_PLS);
549 }
550 
551 static int ci_otg_start_host(struct otg_fsm *fsm, int on)
552 {
553 	struct ci_hdrc	*ci = container_of(fsm, struct ci_hdrc, fsm);
554 
555 	if (on) {
556 		ci_role_stop(ci);
557 		ci_role_start(ci, CI_ROLE_HOST);
558 	} else {
559 		ci_role_stop(ci);
560 		ci_role_start(ci, CI_ROLE_GADGET);
561 	}
562 	return 0;
563 }
564 
565 static int ci_otg_start_gadget(struct otg_fsm *fsm, int on)
566 {
567 	struct ci_hdrc	*ci = container_of(fsm, struct ci_hdrc, fsm);
568 
569 	if (on)
570 		usb_gadget_vbus_connect(&ci->gadget);
571 	else
572 		usb_gadget_vbus_disconnect(&ci->gadget);
573 
574 	return 0;
575 }
576 
577 static struct otg_fsm_ops ci_otg_ops = {
578 	.drv_vbus = ci_otg_drv_vbus,
579 	.loc_conn = ci_otg_loc_conn,
580 	.loc_sof = ci_otg_loc_sof,
581 	.start_pulse = ci_otg_start_pulse,
582 	.add_timer = ci_otg_fsm_add_timer,
583 	.del_timer = ci_otg_fsm_del_timer,
584 	.start_host = ci_otg_start_host,
585 	.start_gadget = ci_otg_start_gadget,
586 };
587 
588 int ci_otg_fsm_work(struct ci_hdrc *ci)
589 {
590 	/*
591 	 * Don't do fsm transition for B device
592 	 * when there is no gadget class driver
593 	 */
594 	if (ci->fsm.id && !(ci->driver) &&
595 		ci->fsm.otg->state < OTG_STATE_A_IDLE)
596 		return 0;
597 
598 	pm_runtime_get_sync(ci->dev);
599 	if (otg_statemachine(&ci->fsm)) {
600 		if (ci->fsm.otg->state == OTG_STATE_A_IDLE) {
601 			/*
602 			 * Further state change for cases:
603 			 * a_idle to b_idle; or
604 			 * a_idle to a_wait_vrise due to ID change(1->0), so
605 			 * B-dev becomes A-dev can try to start new session
606 			 * consequently; or
607 			 * a_idle to a_wait_vrise when power up
608 			 */
609 			if ((ci->fsm.id) || (ci->id_event) ||
610 						(ci->fsm.power_up)) {
611 				ci_otg_queue_work(ci);
612 			} else {
613 				/* Enable data pulse irq */
614 				hw_write(ci, OP_PORTSC, PORTSC_W1C_BITS |
615 								PORTSC_PP, 0);
616 				hw_write_otgsc(ci, OTGSC_DPIS, OTGSC_DPIS);
617 				hw_write_otgsc(ci, OTGSC_DPIE, OTGSC_DPIE);
618 			}
619 			if (ci->id_event)
620 				ci->id_event = false;
621 		} else if (ci->fsm.otg->state == OTG_STATE_B_IDLE) {
622 			if (ci->fsm.b_sess_vld) {
623 				ci->fsm.power_up = 0;
624 				/*
625 				 * Further transite to b_periphearl state
626 				 * when register gadget driver with vbus on
627 				 */
628 				ci_otg_queue_work(ci);
629 			}
630 		} else if (ci->fsm.otg->state == OTG_STATE_A_HOST) {
631 			pm_runtime_mark_last_busy(ci->dev);
632 			pm_runtime_put_autosuspend(ci->dev);
633 			return 0;
634 		}
635 	}
636 	pm_runtime_put_sync(ci->dev);
637 	return 0;
638 }
639 
640 /*
641  * Update fsm variables in each state if catching expected interrupts,
642  * called by otg fsm isr.
643  */
644 static void ci_otg_fsm_event(struct ci_hdrc *ci)
645 {
646 	u32 intr_sts, otg_bsess_vld, port_conn;
647 	struct otg_fsm *fsm = &ci->fsm;
648 
649 	intr_sts = hw_read_intr_status(ci);
650 	otg_bsess_vld = hw_read_otgsc(ci, OTGSC_BSV);
651 	port_conn = hw_read(ci, OP_PORTSC, PORTSC_CCS);
652 
653 	switch (ci->fsm.otg->state) {
654 	case OTG_STATE_A_WAIT_BCON:
655 		if (port_conn) {
656 			fsm->b_conn = 1;
657 			fsm->a_bus_req = 1;
658 			ci_otg_queue_work(ci);
659 		}
660 		break;
661 	case OTG_STATE_B_IDLE:
662 		if (otg_bsess_vld && (intr_sts & USBi_PCI) && port_conn) {
663 			fsm->b_sess_vld = 1;
664 			ci_otg_queue_work(ci);
665 		}
666 		break;
667 	case OTG_STATE_B_PERIPHERAL:
668 		if ((intr_sts & USBi_SLI) && port_conn && otg_bsess_vld) {
669 			ci_otg_add_timer(ci, B_AIDL_BDIS);
670 		} else if (intr_sts & USBi_PCI) {
671 			ci_otg_del_timer(ci, B_AIDL_BDIS);
672 			if (fsm->a_bus_suspend == 1)
673 				fsm->a_bus_suspend = 0;
674 		}
675 		break;
676 	case OTG_STATE_B_HOST:
677 		if ((intr_sts & USBi_PCI) && !port_conn) {
678 			fsm->a_conn = 0;
679 			fsm->b_bus_req = 0;
680 			ci_otg_queue_work(ci);
681 		}
682 		break;
683 	case OTG_STATE_A_PERIPHERAL:
684 		if (intr_sts & USBi_SLI) {
685 			 fsm->b_bus_suspend = 1;
686 			/*
687 			 * Init a timer to know how long this suspend
688 			 * will continue, if time out, indicates B no longer
689 			 * wants to be host role
690 			 */
691 			 ci_otg_add_timer(ci, A_BIDL_ADIS);
692 		}
693 
694 		if (intr_sts & USBi_URI)
695 			ci_otg_del_timer(ci, A_BIDL_ADIS);
696 
697 		if (intr_sts & USBi_PCI) {
698 			if (fsm->b_bus_suspend == 1) {
699 				ci_otg_del_timer(ci, A_BIDL_ADIS);
700 				fsm->b_bus_suspend = 0;
701 			}
702 		}
703 		break;
704 	case OTG_STATE_A_SUSPEND:
705 		if ((intr_sts & USBi_PCI) && !port_conn) {
706 			fsm->b_conn = 0;
707 
708 			/* if gadget driver is binded */
709 			if (ci->driver) {
710 				/* A device to be peripheral mode */
711 				ci->gadget.is_a_peripheral = 1;
712 			}
713 			ci_otg_queue_work(ci);
714 		}
715 		break;
716 	case OTG_STATE_A_HOST:
717 		if ((intr_sts & USBi_PCI) && !port_conn) {
718 			fsm->b_conn = 0;
719 			ci_otg_queue_work(ci);
720 		}
721 		break;
722 	case OTG_STATE_B_WAIT_ACON:
723 		if ((intr_sts & USBi_PCI) && port_conn) {
724 			fsm->a_conn = 1;
725 			ci_otg_queue_work(ci);
726 		}
727 		break;
728 	default:
729 		break;
730 	}
731 }
732 
733 /*
734  * ci_otg_irq - otg fsm related irq handling
735  * and also update otg fsm variable by monitoring usb host and udc
736  * state change interrupts.
737  * @ci: ci_hdrc
738  */
739 irqreturn_t ci_otg_fsm_irq(struct ci_hdrc *ci)
740 {
741 	irqreturn_t retval =  IRQ_NONE;
742 	u32 otgsc, otg_int_src = 0;
743 	struct otg_fsm *fsm = &ci->fsm;
744 
745 	otgsc = hw_read_otgsc(ci, ~0);
746 	otg_int_src = otgsc & OTGSC_INT_STATUS_BITS & (otgsc >> 8);
747 	fsm->id = (otgsc & OTGSC_ID) ? 1 : 0;
748 
749 	if (otg_int_src) {
750 		if (otg_int_src & OTGSC_DPIS) {
751 			hw_write_otgsc(ci, OTGSC_DPIS, OTGSC_DPIS);
752 			fsm->a_srp_det = 1;
753 			fsm->a_bus_drop = 0;
754 		} else if (otg_int_src & OTGSC_IDIS) {
755 			hw_write_otgsc(ci, OTGSC_IDIS, OTGSC_IDIS);
756 			if (fsm->id == 0) {
757 				fsm->a_bus_drop = 0;
758 				fsm->a_bus_req = 1;
759 				ci->id_event = true;
760 			}
761 		} else if (otg_int_src & OTGSC_BSVIS) {
762 			hw_write_otgsc(ci, OTGSC_BSVIS, OTGSC_BSVIS);
763 			if (otgsc & OTGSC_BSV) {
764 				fsm->b_sess_vld = 1;
765 				ci_otg_del_timer(ci, B_SSEND_SRP);
766 				ci_otg_del_timer(ci, B_SRP_FAIL);
767 				fsm->b_ssend_srp = 0;
768 			} else {
769 				fsm->b_sess_vld = 0;
770 				if (fsm->id)
771 					ci_otg_add_timer(ci, B_SSEND_SRP);
772 			}
773 		} else if (otg_int_src & OTGSC_AVVIS) {
774 			hw_write_otgsc(ci, OTGSC_AVVIS, OTGSC_AVVIS);
775 			if (otgsc & OTGSC_AVV) {
776 				fsm->a_vbus_vld = 1;
777 			} else {
778 				fsm->a_vbus_vld = 0;
779 				fsm->b_conn = 0;
780 			}
781 		}
782 		ci_otg_queue_work(ci);
783 		return IRQ_HANDLED;
784 	}
785 
786 	ci_otg_fsm_event(ci);
787 
788 	return retval;
789 }
790 
791 void ci_hdrc_otg_fsm_start(struct ci_hdrc *ci)
792 {
793 	ci_otg_queue_work(ci);
794 }
795 
796 int ci_hdrc_otg_fsm_init(struct ci_hdrc *ci)
797 {
798 	int retval = 0;
799 
800 	if (ci->phy)
801 		ci->otg.phy = ci->phy;
802 	else
803 		ci->otg.usb_phy = ci->usb_phy;
804 
805 	ci->otg.gadget = &ci->gadget;
806 	ci->fsm.otg = &ci->otg;
807 	ci->fsm.power_up = 1;
808 	ci->fsm.id = hw_read_otgsc(ci, OTGSC_ID) ? 1 : 0;
809 	ci->fsm.otg->state = OTG_STATE_UNDEFINED;
810 	ci->fsm.ops = &ci_otg_ops;
811 	ci->gadget.hnp_polling_support = 1;
812 	ci->fsm.host_req_flag = devm_kzalloc(ci->dev, 1, GFP_KERNEL);
813 	if (!ci->fsm.host_req_flag)
814 		return -ENOMEM;
815 
816 	mutex_init(&ci->fsm.lock);
817 
818 	retval = ci_otg_init_timers(ci);
819 	if (retval) {
820 		dev_err(ci->dev, "Couldn't init OTG timers\n");
821 		return retval;
822 	}
823 	ci->enabled_otg_timer_bits = 0;
824 	ci->next_otg_timer = NUM_OTG_FSM_TIMERS;
825 
826 	retval = sysfs_create_group(&ci->dev->kobj, &inputs_attr_group);
827 	if (retval < 0) {
828 		dev_dbg(ci->dev,
829 			"Can't register sysfs attr group: %d\n", retval);
830 		return retval;
831 	}
832 
833 	/* Enable A vbus valid irq */
834 	hw_write_otgsc(ci, OTGSC_AVVIE, OTGSC_AVVIE);
835 
836 	if (ci->fsm.id) {
837 		ci->fsm.b_ssend_srp =
838 			hw_read_otgsc(ci, OTGSC_BSV) ? 0 : 1;
839 		ci->fsm.b_sess_vld =
840 			hw_read_otgsc(ci, OTGSC_BSV) ? 1 : 0;
841 		/* Enable BSV irq */
842 		hw_write_otgsc(ci, OTGSC_BSVIE, OTGSC_BSVIE);
843 	}
844 
845 	return 0;
846 }
847 
848 void ci_hdrc_otg_fsm_remove(struct ci_hdrc *ci)
849 {
850 	sysfs_remove_group(&ci->dev->kobj, &inputs_attr_group);
851 }
852