summaryrefslogtreecommitdiffstats
path: root/drivers/usb/chipidea/otg_fsm.c
blob: ada78daba6df9cd89a616aa30f72cfee2f3d58c1 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
// SPDX-License-Identifier: GPL-2.0
/*
 * otg_fsm.c - ChipIdea USB IP core OTG FSM driver
 *
 * Copyright (C) 2014 Freescale Semiconductor, Inc.
 *
 * Author: Jun Li
 */

/*
 * This file mainly handles OTG fsm, it includes OTG fsm operations
 * for HNP and SRP.
 *
 * TODO List
 * - ADP
 * - OTG test device
 */

#include <linux/usb/otg.h>
#include <linux/usb/gadget.h>
#include <linux/usb/hcd.h>
#include <linux/usb/chipidea.h>
#include <linux/regulator/consumer.h>

#include "ci.h"
#include "bits.h"
#include "otg.h"
#include "otg_fsm.h"

/* Add for otg: interact with user space app */
static ssize_t
a_bus_req_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	char		*next;
	unsigned	size, t;
	struct ci_hdrc	*ci = dev_get_drvdata(dev);

	next = buf;
	size = PAGE_SIZE;
	t = scnprintf(next, size, "%d\n", ci->fsm.a_bus_req);
	size -= t;
	next += t;

	return PAGE_SIZE - size;
}

static ssize_t
a_bus_req_store(struct device *dev, struct device_attribute *attr,
					const char *buf, size_t count)
{
	struct ci_hdrc *ci = dev_get_drvdata(dev);

	if (count > 2)
		return -1;

	mutex_lock(&ci->fsm.lock);
	if (buf[0] == '0') {
		ci->fsm.a_bus_req = 0;
	} else if (buf[0] == '1') {
		/* If a_bus_drop is TRUE, a_bus_req can't be set */
		if (ci->fsm.a_bus_drop) {
			mutex_unlock(&ci->fsm.lock);
			return count;
		}
		ci->fsm.a_bus_req = 1;
		if (ci->fsm.otg->state == OTG_STATE_A_PERIPHERAL) {
			ci->gadget.host_request_flag = 1;
			mutex_unlock(&ci->fsm.lock);
			return count;
		}
	}

	ci_otg_queue_work(ci);
	mutex_unlock(&ci->fsm.lock);

	return count;
}
static DEVICE_ATTR_RW(a_bus_req);

static ssize_t
a_bus_drop_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	char		*next;
	unsigned	size, t;
	struct ci_hdrc	*ci = dev_get_drvdata(dev);

	next = buf;
	size = PAGE_SIZE;
	t = scnprintf(next, size, "%d\n", ci->fsm.a_bus_drop);
	size -= t;
	next += t;

	return PAGE_SIZE - size;
}

static ssize_t
a_bus_drop_store(struct device *dev, struct device_attribute *attr,
					const char *buf, size_t count)
{
	struct ci_hdrc	*ci = dev_get_drvdata(dev);

	if (count > 2)
		return -1;

	mutex_lock(&ci->fsm.lock);
	if (buf[0] == '0') {
		ci->fsm.a_bus_drop = 0;
	} else if (buf[0] == '1') {
		ci->fsm.a_bus_drop = 1;
		ci->fsm.a_bus_req = 0;
	}

	ci_otg_queue_work(ci);
	mutex_unlock(&ci->fsm.lock);

	return count;
}
static DEVICE_ATTR_RW(a_bus_drop);

static ssize_t
b_bus_req_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	char		*next;
	unsigned	size, t;
	struct ci_hdrc	*ci = dev_get_drvdata(dev);

	next = buf;
	size = PAGE_SIZE;
	t = scnprintf(next, size, "%d\n", ci->fsm.b_bus_req);
	size -= t;
	next += t;

	return PAGE_SIZE - size;
}

static ssize_t
b_bus_req_store(struct device *dev, struct device_attribute *attr,
					const char *buf, size_t count)
{
	struct ci_hdrc	*ci = dev_get_drvdata(dev);

	if (count > 2)
		return -1;

	mutex_lock(&ci->fsm.lock);
	if (buf[0] == '0')
		ci->fsm.b_bus_req = 0;
	else if (buf[0] == '1') {
		ci->fsm.b_bus_req = 1;
		if (ci->fsm.otg->state == OTG_STATE_B_PERIPHERAL) {
			ci->gadget.host_request_flag = 1;
			mutex_unlock(&ci->fsm.lock);
			return count;
		}
	}

	ci_otg_queue_work(ci);
	mutex_unlock(&ci->fsm.lock);

	return count;
}
static DEVICE_ATTR_RW(b_bus_req);

static ssize_t
a_clr_err_store(struct device *dev, struct device_attribute *attr,
					const char *buf, size_t count)
{
	struct ci_hdrc	*ci = dev_get_drvdata(dev);

	if (count > 2)
		return -1;

	mutex_lock(&ci->fsm.lock);
	if (buf[0] == '1')
		ci->fsm.a_clr_err = 1;

	ci_otg_queue_work(ci);
	mutex_unlock(&ci->fsm.lock);

	return count;
}
static DEVICE_ATTR_WO(a_clr_err);

static struct attribute *inputs_attrs[] = {
	&dev_attr_a_bus_req.attr,
	&dev_attr_a_bus_drop.attr,
	&dev_attr_b_bus_req.attr,
	&dev_attr_a_clr_err.attr,
	NULL,
};

static const struct attribute_group inputs_attr_group = {
	.name = "inputs",
	.attrs = inputs_attrs,
};

/*
 * Keep this list in the same order as timers indexed
 * by enum otg_fsm_timer in include/linux/usb/otg-fsm.h
 */
static unsigned otg_timer_ms[] = {
	TA_WAIT_VRISE,
	TA_WAIT_VFALL,
	TA_WAIT_BCON,
	TA_AIDL_BDIS,
	TB_ASE0_BRST,
	TA_BIDL_ADIS,
	TB_AIDL_BDIS,
	TB_SE0_SRP,
	TB_SRP_FAIL,
	0,
	TB_DATA_PLS,
	TB_SSEND_SRP,
};

/*
 * Add timer to active timer list
 */
static void ci_otg_add_timer(struct ci_hdrc *ci, enum otg_fsm_timer t)
{
	unsigned long flags, timer_sec, timer_nsec;

	if (t >= NUM_OTG_FSM_TIMERS)
		return;

	spin_lock_irqsave(&ci->lock, flags);
	timer_sec = otg_timer_ms[t] / MSEC_PER_SEC;
	timer_nsec = (otg_timer_ms[t] % MSEC_PER_SEC) * NSEC_PER_MSEC;
	ci->hr_timeouts[t] = ktime_add(ktime_get(),
				ktime_set(timer_sec, timer_nsec));
	ci->enabled_otg_timer_bits |= (1 << t);
	if ((ci->next_otg_timer == NUM_OTG_FSM_TIMERS) ||
			ktime_after(ci->hr_timeouts[ci->next_otg_timer],
						ci->hr_timeouts[t])) {
			ci->next_otg_timer = t;
			hrtimer_start_range_ns(&ci->otg_fsm_hrtimer,
					ci->hr_timeouts[t], NSEC_PER_MSEC,
							HRTIMER_MODE_ABS);
	}
	spin_unlock_irqrestore(&ci->lock, flags);
}

/*
 * Remove timer from active timer list
 */
static void ci_otg_del_timer(struct ci_hdrc *ci, enum otg_fsm_timer t)
{
	unsigned long flags, enabled_timer_bits;
	enum otg_fsm_timer cur_timer, next_timer = NUM_OTG_FSM_TIMERS;

	if ((t >= NUM_OTG_FSM_TIMERS) ||
			!(ci->enabled_otg_timer_bits & (1 << t)))
		return;

	spin_lock_irqsave(&ci->lock, flags);
	ci->enabled_otg_timer_bits &= ~(1 << t);
	if (ci->next_otg_timer == t) {
		if (ci->enabled_otg_timer_bits == 0) {
			/* No enabled timers after delete it */
			hrtimer_cancel(&ci->otg_fsm_hrtimer);
			ci->next_otg_timer = NUM_OTG_FSM_TIMERS;
		} else {
			/* Find the next timer */
			enabled_timer_bits = ci->enabled_otg_timer_bits;
			for_each_set_bit(cur_timer, &enabled_timer_bits,
							NUM_OTG_FSM_TIMERS) {
				if ((next_timer == NUM_OTG_FSM_TIMERS) ||
					ktime_before(ci->hr_timeouts[next_timer],
					 ci->hr_timeouts[cur_timer]))
					next_timer = cur_timer;
			}
		}
	}
	if (next_timer != NUM_OTG_FSM_TIMERS) {
		ci->next_otg_timer = next_timer;
		hrtimer_start_range_ns(&ci->otg_fsm_hrtimer,
			ci->hr_timeouts[next_timer], NSEC_PER_MSEC,
							HRTIMER_MODE_ABS);
	}
	spin_unlock_irqrestore(&ci->lock, flags);
}

/* OTG FSM timer handlers */
static int a_wait_vrise_tmout(struct ci_hdrc *ci)
{
	ci->fsm.a_wait_vrise_tmout = 1;
	return 0;
}

static int a_wait_vfall_tmout(struct ci_hdrc *ci)
{
	ci->fsm.a_wait_vfall_tmout = 1;
	return 0;
}

static int a_wait_bcon_tmout(struct ci_hdrc *ci)
{
	ci->fsm.a_wait_bcon_tmout = 1;
	return 0;
}

static int a_aidl_bdis_tmout(struct ci_hdrc *ci)
{
	ci->fsm.a_aidl_bdis_tmout = 1;
	return 0;
}

static int b_ase0_brst_tmout(struct ci_hdrc *ci)
{
	ci->fsm.b_ase0_brst_tmout = 1;
	return 0;
}

static int a_bidl_adis_tmout(struct ci_hdrc *ci)
{
	ci->fsm.a_bidl_adis_tmout = 1;
	return 0;
}

static int b_aidl_bdis_tmout(struct ci_hdrc *ci)
{
	ci->fsm.a_bus_suspend = 1;
	return 0;
}

static int b_se0_srp_tmout(struct ci_hdrc *ci)
{
	ci->fsm.b_se0_srp = 1;
	return 0;
}

static int b_srp_fail_tmout(struct ci_hdrc *ci)
{
	ci->fsm.b_srp_done = 1;
	return 1;
}

static int b_data_pls_tmout(struct ci_hdrc *ci)
{
	ci->fsm.b_srp_done = 1;
	ci->fsm.b_bus_req = 0;
	if (ci->fsm.power_up)
		ci->fsm.power_up = 0;
	hw_write_otgsc(ci, OTGSC_HABA, 0);
	pm_runtime_put(ci->dev);
	return 0;
}

static int b_ssend_srp_tmout(struct ci_hdrc *ci)
{
	ci->fsm.b_ssend_srp = 1;
	/* only vbus fall below B_sess_vld in b_idle state */
	if (ci->fsm.otg->state == OTG_STATE_B_IDLE)
		return 0;
	else
		return 1;
}

/*
 * Keep this list in the same order as timers indexed
 * by enum otg_fsm_timer in include/linux/usb/otg-fsm.h
 */
static int (*otg_timer_handlers[])(struct ci_hdrc *) = {
	a_wait_vrise_tmout,	/* A_WAIT_VRISE */
	a_wait_vfall_tmout,	/* A_WAIT_VFALL */
	a_wait_bcon_tmout,	/* A_WAIT_BCON */
	a_aidl_bdis_tmout,	/* A_AIDL_BDIS */
	b_ase0_brst_tmout,	/* B_ASE0_BRST */
	a_bidl_adis_tmout,	/* A_BIDL_ADIS */
	b_aidl_bdis_tmout,	/* B_AIDL_BDIS */
	b_se0_srp_tmout,	/* B_SE0_SRP */
	b_srp_fail_tmout,	/* B_SRP_FAIL */
	NULL,			/* A_WAIT_ENUM */
	b_data_pls_tmout,	/* B_DATA_PLS */
	b_ssend_srp_tmout,	/* B_SSEND_SRP */
};

/*
 * Enable the next nearest enabled timer if have
 */
static enum hrtimer_restart ci_otg_hrtimer_func(struct hrtimer *t)
{
	struct ci_hdrc *ci = container_of(t, struct ci_hdrc, otg_fsm_hrtimer);
	ktime_t	now, *timeout;
	unsigned long   enabled_timer_bits;
	unsigned long   flags;
	enum otg_fsm_timer cur_timer, next_timer = NUM_OTG_FSM_TIMERS;
	int ret = -EINVAL;

	spin_lock_irqsave(&ci->lock, flags);
	enabled_timer_bits = ci->enabled_otg_timer_bits;
	ci->next_otg_timer = NUM_OTG_FSM_TIMERS;

	now = ktime_get();
	for_each_set_bit(cur_timer, &enabled_timer_bits, NUM_OTG_FSM_TIMERS) {
		if (ktime_compare(now, ci->hr_timeouts[cur_timer]) >= 0) {
			ci->enabled_otg_timer_bits &= ~(1 << cur_timer);
			if (otg_timer_handlers[cur_timer])
				ret = otg_timer_handlers[cur_timer](ci);
		} else {
			if ((next_timer == NUM_OTG_FSM_TIMERS) ||
				ktime_before(ci->hr_timeouts[cur_timer],
					ci->hr_timeouts[next_timer]))
				next_timer = cur_timer;
		}
	}
	/* Enable the next nearest timer */
	if (next_timer < NUM_OTG_FSM_TIMERS) {
		timeout = &ci->hr_timeouts[next_timer];
		hrtimer_start_range_ns(&ci->otg_fsm_hrtimer, *timeout,
					NSEC_PER_MSEC, HRTIMER_MODE_ABS);
		ci->next_otg_timer = next_timer;
	}
	spin_unlock_irqrestore(&ci->lock, flags);

	if (!ret)
		ci_otg_queue_work(ci);

	return HRTIMER_NORESTART;
}

/* Initialize timers */
static int ci_otg_init_timers(struct ci_hdrc *ci)
{
	hrtimer_init(&ci->otg_fsm_hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
	ci->otg_fsm_hrtimer.function = ci_otg_hrtimer_func;

	return 0;
}

/* -------------------------------------------------------------*/
/* Operations that will be called from OTG Finite State Machine */
/* -------------------------------------------------------------*/
static void ci_otg_fsm_add_timer(struct otg_fsm *fsm, enum otg_fsm_timer t)
{
	struct ci_hdrc	*ci = container_of(fsm, struct ci_hdrc, fsm);

	if (t < NUM_OTG_FSM_TIMERS)
		ci_otg_add_timer(ci, t);
	return;
}

static void ci_otg_fsm_del_timer(struct otg_fsm *fsm, enum otg_fsm_timer t)
{
	struct ci_hdrc	*ci = container_of(fsm, struct ci_hdrc, fsm);

	if (t < NUM_OTG_FSM_TIMERS)
		ci_otg_del_timer(ci, t);
	return;
}

/*
 * A-device drive vbus: turn on vbus regulator and enable port power
 * Data pulse irq should be disabled while vbus is on.
 */
static void ci_otg_drv_vbus(struct otg_fsm *fsm, int on)
{
	int ret;
	struct ci_hdrc	*ci = container_of(fsm, struct ci_hdrc, fsm);

	if (on) {
		/* Enable power */
		hw_write(ci, OP_PORTSC, PORTSC_W1C_BITS | PORTSC_PP,
							PORTSC_PP);
		if (ci->platdata->reg_vbus) {
			ret = regulator_enable(ci->platdata->reg_vbus);
			if (ret) {
				dev_err(ci->dev,
				"Failed to enable vbus regulator, ret=%d\n",
				ret);
				return;
			}
		}

		if (ci->platdata->flags & CI_HDRC_PHY_VBUS_CONTROL)
			usb_phy_vbus_on(ci->usb_phy);

		/* Disable data pulse irq */
		hw_write_otgsc(ci, OTGSC_DPIE, 0);

		fsm->a_srp_det = 0;
		fsm->power_up = 0;
	} else {
		if (ci->platdata->reg_vbus)
			regulator_disable(ci->platdata->reg_vbus);

		if (ci->platdata->flags & CI_HDRC_PHY_VBUS_CONTROL)
			usb_phy_vbus_off(ci->usb_phy);

		fsm->a_bus_drop = 1;
		fsm->a_bus_req = 0;
	}
}

/*
 * Control data line by Run Stop bit.
 */
static void ci_otg_loc_conn(struct otg_fsm *fsm, int on)
{
	struct ci_hdrc	*ci = container_of(fsm, struct ci_hdrc, fsm);

	if (on)
		hw_write(ci, OP_USBCMD, USBCMD_RS, USBCMD_RS);
	else
		hw_write(ci, OP_USBCMD, USBCMD_RS, 0);
}

/*
 * Generate SOF by host.
 * In host mode, controller will automatically send SOF.
 * Suspend will block the data on the port.
 *
 * This is controlled through usbcore by usb autosuspend,
 * so the usb device class driver need support autosuspend,
 * otherwise the bus suspend will not happen.
 */
static void ci_otg_loc_sof(struct otg_fsm *fsm, int on)
{
	struct usb_device *udev;

	if (!fsm->otg->host)
		return;

	udev = usb_hub_find_child(fsm->otg->host->root_hub, 1);
	if (!udev)
		return;

	if (on) {
		usb_disable_autosuspend(udev);
	} else {
		pm_runtime_set_autosuspend_delay(&udev->dev, 0);
		usb_enable_autosuspend(udev);
	}
}

/*
 * Start SRP pulsing by data-line pulsing,
 * no v-bus pulsing followed
 */
static void ci_otg_start_pulse(struct otg_fsm *fsm)
{
	struct ci_hdrc	*ci = container_of(fsm, struct ci_hdrc, fsm);

	/* Hardware Assistant Data pulse */
	hw_write_otgsc(ci, OTGSC_HADP, OTGSC_HADP);

	pm_runtime_get(ci->dev);
	ci_otg_add_timer(ci, B_DATA_PLS);
}

static int ci_otg_start_host(struct otg_fsm *fsm, int on)
{
	struct ci_hdrc	*ci = container_of(fsm, struct ci_hdrc, fsm);

	if (on) {
		ci_role_stop(ci);
		ci_role_start(ci, CI_ROLE_HOST);
	} else {
		ci_role_stop(ci);
		ci_role_start(ci, CI_ROLE_GADGET);
	}
	return 0;
}

static int ci_otg_start_gadget(struct otg_fsm *fsm, int on)
{
	struct ci_hdrc	*ci = container_of(fsm, struct ci_hdrc, fsm);

	if (on)
		usb_gadget_vbus_connect(&ci->gadget);
	else
		usb_gadget_vbus_disconnect(&ci->gadget);

	return 0;
}

static struct otg_fsm_ops ci_otg_ops = {
	.drv_vbus = ci_otg_drv_vbus,
	.loc_conn = ci_otg_loc_conn,
	.loc_sof = ci_otg_loc_sof,
	.start_pulse = ci_otg_start_pulse,
	.add_timer = ci_otg_fsm_add_timer,
	.del_timer = ci_otg_fsm_del_timer,
	.start_host = ci_otg_start_host,
	.start_gadget = ci_otg_start_gadget,
};

int ci_otg_fsm_work(struct ci_hdrc *ci)
{
	/*
	 * Don't do fsm transition for B device
	 * when there is no gadget class driver
	 */
	if (ci->fsm.id && !(ci->driver) &&
		ci->fsm.otg->state < OTG_STATE_A_IDLE)
		return 0;

	pm_runtime_get_sync(ci->dev);
	if (otg_statemachine(&ci->fsm)) {
		if (ci->fsm.otg->state == OTG_STATE_A_IDLE) {
			/*
			 * Further state change for cases:
			 * a_idle to b_idle; or
			 * a_idle to a_wait_vrise due to ID change(1->0), so
			 * B-dev becomes A-dev can try to start new session
			 * consequently; or
			 * a_idle to a_wait_vrise when power up
			 */
			if ((ci->fsm.id) || (ci->id_event) ||
						(ci->fsm.power_up)) {
				ci_otg_queue_work(ci);
			} else {
				/* Enable data pulse irq */
				hw_write(ci, OP_PORTSC, PORTSC_W1C_BITS |
								PORTSC_PP, 0);
				hw_write_otgsc(ci, OTGSC_DPIS, OTGSC_DPIS);
				hw_write_otgsc(ci, OTGSC_DPIE, OTGSC_DPIE);
			}
			if (ci->id_event)
				ci->id_event = false;
		} else if (ci->fsm.otg->state == OTG_STATE_B_IDLE) {
			if (ci->fsm.b_sess_vld) {
				ci->fsm.power_up = 0;
				/*
				 * Further transite to b_periphearl state
				 * when register gadget driver with vbus on
				 */
				ci_otg_queue_work(ci);
			}
		} else if (ci->fsm.otg->state == OTG_STATE_A_HOST) {
			pm_runtime_mark_last_busy(ci->dev);
			pm_runtime_put_autosuspend(ci->dev);
			return 0;
		}
	}
	pm_runtime_put_sync(ci->dev);
	return 0;
}

/*
 * Update fsm variables in each state if catching expected interrupts,
 * called by otg fsm isr.
 */
static void ci_otg_fsm_event(struct ci_hdrc *ci)
{
	u32 intr_sts, otg_bsess_vld, port_conn;
	struct otg_fsm *fsm = &ci->fsm;

	intr_sts = hw_read_intr_status(ci);
	otg_bsess_vld = hw_read_otgsc(ci, OTGSC_BSV);
	port_conn = hw_read(ci, OP_PORTSC, PORTSC_CCS);

	switch (ci->fsm.otg->state) {
	case OTG_STATE_A_WAIT_BCON:
		if (port_conn) {
			fsm->b_conn = 1;
			fsm->a_bus_req = 1;
			ci_otg_queue_work(ci);
		}
		break;
	case OTG_STATE_B_IDLE:
		if (otg_bsess_vld && (intr_sts & USBi_PCI) && port_conn) {
			fsm->b_sess_vld = 1;
			ci_otg_queue_work(ci);
		}
		break;
	case OTG_STATE_B_PERIPHERAL:
		if ((intr_sts & USBi_SLI) && port_conn && otg_bsess_vld) {
			ci_otg_add_timer(ci, B_AIDL_BDIS);
		} else if (intr_sts & USBi_PCI) {
			ci_otg_del_timer(ci, B_AIDL_BDIS);
			if (fsm->a_bus_suspend == 1)
				fsm->a_bus_suspend = 0;
		}
		break;
	case OTG_STATE_B_HOST:
		if ((intr_sts & USBi_PCI) && !port_conn) {
			fsm->a_conn = 0;
			fsm->b_bus_req = 0;
			ci_otg_queue_work(ci);
		}
		break;
	case OTG_STATE_A_PERIPHERAL:
		if (intr_sts & USBi_SLI) {
			 fsm->b_bus_suspend = 1;
			/*
			 * Init a timer to know how long this suspend
			 * will continue, if time out, indicates B no longer
			 * wants to be host role
			 */
			 ci_otg_add_timer(ci, A_BIDL_ADIS);
		}

		if (intr_sts & USBi_URI)
			ci_otg_del_timer(ci, A_BIDL_ADIS);

		if (intr_sts & USBi_PCI) {
			if (fsm->b_bus_suspend == 1) {
				ci_otg_del_timer(ci, A_BIDL_ADIS);
				fsm->b_bus_suspend = 0;
			}
		}
		break;
	case OTG_STATE_A_SUSPEND:
		if ((intr_sts & USBi_PCI) && !port_conn) {
			fsm->b_conn = 0;

			/* if gadget driver is binded */
			if (ci->driver) {
				/* A device to be peripheral mode */
				ci->gadget.is_a_peripheral = 1;
			}
			ci_otg_queue_work(ci);
		}
		break;
	case OTG_STATE_A_HOST:
		if ((intr_sts & USBi_PCI) && !port_conn) {
			fsm->b_conn = 0;
			ci_otg_queue_work(ci);
		}
		break;
	case OTG_STATE_B_WAIT_ACON:
		if ((intr_sts & USBi_PCI) && port_conn) {
			fsm->a_conn = 1;
			ci_otg_queue_work(ci);
		}
		break;
	default:
		break;
	}
}

/*
 * ci_otg_irq - otg fsm related irq handling
 * and also update otg fsm variable by monitoring usb host and udc
 * state change interrupts.
 * @ci: ci_hdrc
 */
irqreturn_t ci_otg_fsm_irq(struct ci_hdrc *ci)
{
	irqreturn_t retval =  IRQ_NONE;
	u32 otgsc, otg_int_src = 0;
	struct otg_fsm *fsm = &ci->fsm;

	otgsc = hw_read_otgsc(ci, ~0);
	otg_int_src = otgsc & OTGSC_INT_STATUS_BITS & (otgsc >> 8);
	fsm->id = (otgsc & OTGSC_ID) ? 1 : 0;

	if (otg_int_src) {
		if (otg_int_src & OTGSC_DPIS) {
			hw_write_otgsc(ci, OTGSC_DPIS, OTGSC_DPIS);
			fsm->a_srp_det = 1;
			fsm->a_bus_drop = 0;
		} else if (otg_int_src & OTGSC_IDIS) {
			hw_write_otgsc(ci, OTGSC_IDIS, OTGSC_IDIS);
			if (fsm->id == 0) {
				fsm->a_bus_drop = 0;
				fsm->a_bus_req = 1;
				ci->id_event = true;
			}
		} else if (otg_int_src & OTGSC_BSVIS) {
			hw_write_otgsc(ci, OTGSC_BSVIS, OTGSC_BSVIS);
			if (otgsc & OTGSC_BSV) {
				fsm->b_sess_vld = 1;
				ci_otg_del_timer(ci, B_SSEND_SRP);
				ci_otg_del_timer(ci, B_SRP_FAIL);
				fsm->b_ssend_srp = 0;
			} else {
				fsm->b_sess_vld = 0;
				if (fsm->id)
					ci_otg_add_timer(ci, B_SSEND_SRP);
			}
		} else if (otg_int_src & OTGSC_AVVIS) {
			hw_write_otgsc(ci, OTGSC_AVVIS, OTGSC_AVVIS);
			if (otgsc & OTGSC_AVV) {
				fsm->a_vbus_vld = 1;
			} else {
				fsm->a_vbus_vld = 0;
				fsm->b_conn = 0;
			}
		}
		ci_otg_queue_work(ci);
		return IRQ_HANDLED;
	}

	ci_otg_fsm_event(ci);

	return retval;
}

void ci_hdrc_otg_fsm_start(struct ci_hdrc *ci)
{
	ci_otg_queue_work(ci);
}

int ci_hdrc_otg_fsm_init(struct ci_hdrc *ci)
{
	int retval = 0;

	if (ci->phy)
		ci->otg.phy = ci->phy;
	else
		ci->otg.usb_phy = ci->usb_phy;

	ci->otg.gadget = &ci->gadget;
	ci->fsm.otg = &ci->otg;
	ci->fsm.power_up = 1;
	ci->fsm.id = hw_read_otgsc(ci, OTGSC_ID) ? 1 : 0;
	ci->fsm.otg->state = OTG_STATE_UNDEFINED;
	ci->fsm.ops = &ci_otg_ops;
	ci->gadget.hnp_polling_support = 1;
	ci->fsm.host_req_flag = devm_kzalloc(ci->dev, 1, GFP_KERNEL);
	if (!ci->fsm.host_req_flag)
		return -ENOMEM;

	mutex_init(&ci->fsm.lock);

	retval = ci_otg_init_timers(ci);
	if (retval) {
		dev_err(ci->dev, "Couldn't init OTG timers\n");
		return retval;
	}
	ci->enabled_otg_timer_bits = 0;
	ci->next_otg_timer = NUM_OTG_FSM_TIMERS;

	retval = sysfs_create_group(&ci->dev->kobj, &inputs_attr_group);
	if (retval < 0) {
		dev_dbg(ci->dev,
			"Can't register sysfs attr group: %d\n", retval);
		return retval;
	}

	/* Enable A vbus valid irq */
	hw_write_otgsc(ci, OTGSC_AVVIE, OTGSC_AVVIE);

	if (ci->fsm.id) {
		ci->fsm.b_ssend_srp =
			hw_read_otgsc(ci, OTGSC_BSV) ? 0 : 1;
		ci->fsm.b_sess_vld =
			hw_read_otgsc(ci, OTGSC_BSV) ? 1 : 0;
		/* Enable BSV irq */
		hw_write_otgsc(ci, OTGSC_BSVIE, OTGSC_BSVIE);
	}

	return 0;
}

void ci_hdrc_otg_fsm_remove(struct ci_hdrc *ci)
{
	sysfs_remove_group(&ci->dev->kobj, &inputs_attr_group);
}