summaryrefslogtreecommitdiffstats
path: root/drivers/usb/phy/phy-mv-usb.c
blob: 7d80c54f0ac66924c2d228944c1fcbf23f45eb5e (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
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
/*
 * Copyright (C) 2011 Marvell International Ltd. All rights reserved.
 * Author: Chao Xie <chao.xie@marvell.com>
 *	   Neil Zhang <zhangwm@marvell.com>
 *
 * This program is free software; you can redistribute  it and/or modify it
 * under  the terms of  the GNU General  Public License as published by the
 * Free Software Foundation;  either version 2 of the  License, or (at your
 * option) any later version.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/io.h>
#include <linux/uaccess.h>
#include <linux/device.h>
#include <linux/proc_fs.h>
#include <linux/clk.h>
#include <linux/workqueue.h>
#include <linux/platform_device.h>

#include <linux/usb.h>
#include <linux/usb/ch9.h>
#include <linux/usb/otg.h>
#include <linux/usb/gadget.h>
#include <linux/usb/hcd.h>
#include <linux/platform_data/mv_usb.h>

#include "phy-mv-usb.h"

#define	DRIVER_DESC	"Marvell USB OTG transceiver driver"
#define	DRIVER_VERSION	"Jan 20, 2010"

MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_VERSION(DRIVER_VERSION);
MODULE_LICENSE("GPL");

static const char driver_name[] = "mv-otg";

static char *state_string[] = {
	"undefined",
	"b_idle",
	"b_srp_init",
	"b_peripheral",
	"b_wait_acon",
	"b_host",
	"a_idle",
	"a_wait_vrise",
	"a_wait_bcon",
	"a_host",
	"a_suspend",
	"a_peripheral",
	"a_wait_vfall",
	"a_vbus_err"
};

static int mv_otg_set_vbus(struct usb_otg *otg, bool on)
{
	struct mv_otg *mvotg = container_of(otg->phy, struct mv_otg, phy);
	if (mvotg->pdata->set_vbus == NULL)
		return -ENODEV;

	return mvotg->pdata->set_vbus(on);
}

static int mv_otg_set_host(struct usb_otg *otg,
			   struct usb_bus *host)
{
	otg->host = host;

	return 0;
}

static int mv_otg_set_peripheral(struct usb_otg *otg,
				 struct usb_gadget *gadget)
{
	otg->gadget = gadget;

	return 0;
}

static void mv_otg_run_state_machine(struct mv_otg *mvotg,
				     unsigned long delay)
{
	dev_dbg(&mvotg->pdev->dev, "transceiver is updated\n");
	if (!mvotg->qwork)
		return;

	queue_delayed_work(mvotg->qwork, &mvotg->work, delay);
}

static void mv_otg_timer_await_bcon(unsigned long data)
{
	struct mv_otg *mvotg = (struct mv_otg *) data;

	mvotg->otg_ctrl.a_wait_bcon_timeout = 1;

	dev_info(&mvotg->pdev->dev, "B Device No Response!\n");

	if (spin_trylock(&mvotg->wq_lock)) {
		mv_otg_run_state_machine(mvotg, 0);
		spin_unlock(&mvotg->wq_lock);
	}
}

static int mv_otg_cancel_timer(struct mv_otg *mvotg, unsigned int id)
{
	struct timer_list *timer;

	if (id >= OTG_TIMER_NUM)
		return -EINVAL;

	timer = &mvotg->otg_ctrl.timer[id];

	if (timer_pending(timer))
		del_timer(timer);

	return 0;
}

static int mv_otg_set_timer(struct mv_otg *mvotg, unsigned int id,
			    unsigned long interval,
			    void (*callback) (unsigned long))
{
	struct timer_list *timer;

	if (id >= OTG_TIMER_NUM)
		return -EINVAL;

	timer = &mvotg->otg_ctrl.timer[id];
	if (timer_pending(timer)) {
		dev_err(&mvotg->pdev->dev, "Timer%d is already running\n", id);
		return -EBUSY;
	}

	init_timer(timer);
	timer->data = (unsigned long) mvotg;
	timer->function = callback;
	timer->expires = jiffies + interval;
	add_timer(timer);

	return 0;
}

static int mv_otg_reset(struct mv_otg *mvotg)
{
	unsigned int loops;
	u32 tmp;

	/* Stop the controller */
	tmp = readl(&mvotg->op_regs->usbcmd);
	tmp &= ~USBCMD_RUN_STOP;
	writel(tmp, &mvotg->op_regs->usbcmd);

	/* Reset the controller to get default values */
	writel(USBCMD_CTRL_RESET, &mvotg->op_regs->usbcmd);

	loops = 500;
	while (readl(&mvotg->op_regs->usbcmd) & USBCMD_CTRL_RESET) {
		if (loops == 0) {
			dev_err(&mvotg->pdev->dev,
				"Wait for RESET completed TIMEOUT\n");
			return -ETIMEDOUT;
		}
		loops--;
		udelay(20);
	}

	writel(0x0, &mvotg->op_regs->usbintr);
	tmp = readl(&mvotg->op_regs->usbsts);
	writel(tmp, &mvotg->op_regs->usbsts);

	return 0;
}

static void mv_otg_init_irq(struct mv_otg *mvotg)
{
	u32 otgsc;

	mvotg->irq_en = OTGSC_INTR_A_SESSION_VALID
	    | OTGSC_INTR_A_VBUS_VALID;
	mvotg->irq_status = OTGSC_INTSTS_A_SESSION_VALID
	    | OTGSC_INTSTS_A_VBUS_VALID;

	if (mvotg->pdata->vbus == NULL) {
		mvotg->irq_en |= OTGSC_INTR_B_SESSION_VALID
		    | OTGSC_INTR_B_SESSION_END;
		mvotg->irq_status |= OTGSC_INTSTS_B_SESSION_VALID
		    | OTGSC_INTSTS_B_SESSION_END;
	}

	if (mvotg->pdata->id == NULL) {
		mvotg->irq_en |= OTGSC_INTR_USB_ID;
		mvotg->irq_status |= OTGSC_INTSTS_USB_ID;
	}

	otgsc = readl(&mvotg->op_regs->otgsc);
	otgsc |= mvotg->irq_en;
	writel(otgsc, &mvotg->op_regs->otgsc);
}

static void mv_otg_start_host(struct mv_otg *mvotg, int on)
{
#ifdef CONFIG_USB
	struct usb_otg *otg = mvotg->phy.otg;
	struct usb_hcd *hcd;

	if (!otg->host)
		return;

	dev_info(&mvotg->pdev->dev, "%s host\n", on ? "start" : "stop");

	hcd = bus_to_hcd(otg->host);

	if (on) {
		usb_add_hcd(hcd, hcd->irq, IRQF_SHARED);
		device_wakeup_enable(hcd->self.controller);
	} else {
		usb_remove_hcd(hcd);
	}
#endif /* CONFIG_USB */
}

static void mv_otg_start_periphrals(struct mv_otg *mvotg, int on)
{
	struct usb_otg *otg = mvotg->phy.otg;

	if (!otg->gadget)
		return;

	dev_info(mvotg->phy.dev, "gadget %s\n", on ? "on" : "off");

	if (on)
		usb_gadget_vbus_connect(otg->gadget);
	else
		usb_gadget_vbus_disconnect(otg->gadget);
}

static void otg_clock_enable(struct mv_otg *mvotg)
{
	clk_prepare_enable(mvotg->clk);
}

static void otg_clock_disable(struct mv_otg *mvotg)
{
	clk_disable_unprepare(mvotg->clk);
}

static int mv_otg_enable_internal(struct mv_otg *mvotg)
{
	int retval = 0;

	if (mvotg->active)
		return 0;

	dev_dbg(&mvotg->pdev->dev, "otg enabled\n");

	otg_clock_enable(mvotg);
	if (mvotg->pdata->phy_init) {
		retval = mvotg->pdata->phy_init(mvotg->phy_regs);
		if (retval) {
			dev_err(&mvotg->pdev->dev,
				"init phy error %d\n", retval);
			otg_clock_disable(mvotg);
			return retval;
		}
	}
	mvotg->active = 1;

	return 0;

}

static int mv_otg_enable(struct mv_otg *mvotg)
{
	if (mvotg->clock_gating)
		return mv_otg_enable_internal(mvotg);

	return 0;
}

static void mv_otg_disable_internal(struct mv_otg *mvotg)
{
	if (mvotg->active) {
		dev_dbg(&mvotg->pdev->dev, "otg disabled\n");
		if (mvotg->pdata->phy_deinit)
			mvotg->pdata->phy_deinit(mvotg->phy_regs);
		otg_clock_disable(mvotg);
		mvotg->active = 0;
	}
}

static void mv_otg_disable(struct mv_otg *mvotg)
{
	if (mvotg->clock_gating)
		mv_otg_disable_internal(mvotg);
}

static void mv_otg_update_inputs(struct mv_otg *mvotg)
{
	struct mv_otg_ctrl *otg_ctrl = &mvotg->otg_ctrl;
	u32 otgsc;

	otgsc = readl(&mvotg->op_regs->otgsc);

	if (mvotg->pdata->vbus) {
		if (mvotg->pdata->vbus->poll() == VBUS_HIGH) {
			otg_ctrl->b_sess_vld = 1;
			otg_ctrl->b_sess_end = 0;
		} else {
			otg_ctrl->b_sess_vld = 0;
			otg_ctrl->b_sess_end = 1;
		}
	} else {
		otg_ctrl->b_sess_vld = !!(otgsc & OTGSC_STS_B_SESSION_VALID);
		otg_ctrl->b_sess_end = !!(otgsc & OTGSC_STS_B_SESSION_END);
	}

	if (mvotg->pdata->id)
		otg_ctrl->id = !!mvotg->pdata->id->poll();
	else
		otg_ctrl->id = !!(otgsc & OTGSC_STS_USB_ID);

	if (mvotg->pdata->otg_force_a_bus_req && !otg_ctrl->id)
		otg_ctrl->a_bus_req = 1;

	otg_ctrl->a_sess_vld = !!(otgsc & OTGSC_STS_A_SESSION_VALID);
	otg_ctrl->a_vbus_vld = !!(otgsc & OTGSC_STS_A_VBUS_VALID);

	dev_dbg(&mvotg->pdev->dev, "%s: ", __func__);
	dev_dbg(&mvotg->pdev->dev, "id %d\n", otg_ctrl->id);
	dev_dbg(&mvotg->pdev->dev, "b_sess_vld %d\n", otg_ctrl->b_sess_vld);
	dev_dbg(&mvotg->pdev->dev, "b_sess_end %d\n", otg_ctrl->b_sess_end);
	dev_dbg(&mvotg->pdev->dev, "a_vbus_vld %d\n", otg_ctrl->a_vbus_vld);
	dev_dbg(&mvotg->pdev->dev, "a_sess_vld %d\n", otg_ctrl->a_sess_vld);
}

static void mv_otg_update_state(struct mv_otg *mvotg)
{
	struct mv_otg_ctrl *otg_ctrl = &mvotg->otg_ctrl;
	struct usb_phy *phy = &mvotg->phy;
	int old_state = phy->state;

	switch (old_state) {
	case OTG_STATE_UNDEFINED:
		phy->state = OTG_STATE_B_IDLE;
		/* FALL THROUGH */
	case OTG_STATE_B_IDLE:
		if (otg_ctrl->id == 0)
			phy->state = OTG_STATE_A_IDLE;
		else if (otg_ctrl->b_sess_vld)
			phy->state = OTG_STATE_B_PERIPHERAL;
		break;
	case OTG_STATE_B_PERIPHERAL:
		if (!otg_ctrl->b_sess_vld || otg_ctrl->id == 0)
			phy->state = OTG_STATE_B_IDLE;
		break;
	case OTG_STATE_A_IDLE:
		if (otg_ctrl->id)
			phy->state = OTG_STATE_B_IDLE;
		else if (!(otg_ctrl->a_bus_drop) &&
			 (otg_ctrl->a_bus_req || otg_ctrl->a_srp_det))
			phy->state = OTG_STATE_A_WAIT_VRISE;
		break;
	case OTG_STATE_A_WAIT_VRISE:
		if (otg_ctrl->a_vbus_vld)
			phy->state = OTG_STATE_A_WAIT_BCON;
		break;
	case OTG_STATE_A_WAIT_BCON:
		if (otg_ctrl->id || otg_ctrl->a_bus_drop
		    || otg_ctrl->a_wait_bcon_timeout) {
			mv_otg_cancel_timer(mvotg, A_WAIT_BCON_TIMER);
			mvotg->otg_ctrl.a_wait_bcon_timeout = 0;
			phy->state = OTG_STATE_A_WAIT_VFALL;
			otg_ctrl->a_bus_req = 0;
		} else if (!otg_ctrl->a_vbus_vld) {
			mv_otg_cancel_timer(mvotg, A_WAIT_BCON_TIMER);
			mvotg->otg_ctrl.a_wait_bcon_timeout = 0;
			phy->state = OTG_STATE_A_VBUS_ERR;
		} else if (otg_ctrl->b_conn) {
			mv_otg_cancel_timer(mvotg, A_WAIT_BCON_TIMER);
			mvotg->otg_ctrl.a_wait_bcon_timeout = 0;
			phy->state = OTG_STATE_A_HOST;
		}
		break;
	case OTG_STATE_A_HOST:
		if (otg_ctrl->id || !otg_ctrl->b_conn
		    || otg_ctrl->a_bus_drop)
			phy->state = OTG_STATE_A_WAIT_BCON;
		else if (!otg_ctrl->a_vbus_vld)
			phy->state = OTG_STATE_A_VBUS_ERR;
		break;
	case OTG_STATE_A_WAIT_VFALL:
		if (otg_ctrl->id
		    || (!otg_ctrl->b_conn && otg_ctrl->a_sess_vld)
		    || otg_ctrl->a_bus_req)
			phy->state = OTG_STATE_A_IDLE;
		break;
	case OTG_STATE_A_VBUS_ERR:
		if (otg_ctrl->id || otg_ctrl->a_clr_err
		    || otg_ctrl->a_bus_drop) {
			otg_ctrl->a_clr_err = 0;
			phy->state = OTG_STATE_A_WAIT_VFALL;
		}
		break;
	default:
		break;
	}
}

static void mv_otg_work(struct work_struct *work)
{
	struct mv_otg *mvotg;
	struct usb_phy *phy;
	struct usb_otg *otg;
	int old_state;

	mvotg = container_of(to_delayed_work(work), struct mv_otg, work);

run:
	/* work queue is single thread, or we need spin_lock to protect */
	phy = &mvotg->phy;
	otg = phy->otg;
	old_state = phy->state;

	if (!mvotg->active)
		return;

	mv_otg_update_inputs(mvotg);
	mv_otg_update_state(mvotg);

	if (old_state != phy->state) {
		dev_info(&mvotg->pdev->dev, "change from state %s to %s\n",
			 state_string[old_state],
			 state_string[phy->state]);

		switch (phy->state) {
		case OTG_STATE_B_IDLE:
			otg->default_a = 0;
			if (old_state == OTG_STATE_B_PERIPHERAL)
				mv_otg_start_periphrals(mvotg, 0);
			mv_otg_reset(mvotg);
			mv_otg_disable(mvotg);
			break;
		case OTG_STATE_B_PERIPHERAL:
			mv_otg_enable(mvotg);
			mv_otg_start_periphrals(mvotg, 1);
			break;
		case OTG_STATE_A_IDLE:
			otg->default_a = 1;
			mv_otg_enable(mvotg);
			if (old_state == OTG_STATE_A_WAIT_VFALL)
				mv_otg_start_host(mvotg, 0);
			mv_otg_reset(mvotg);
			break;
		case OTG_STATE_A_WAIT_VRISE:
			mv_otg_set_vbus(otg, 1);
			break;
		case OTG_STATE_A_WAIT_BCON:
			if (old_state != OTG_STATE_A_HOST)
				mv_otg_start_host(mvotg, 1);
			mv_otg_set_timer(mvotg, A_WAIT_BCON_TIMER,
					 T_A_WAIT_BCON,
					 mv_otg_timer_await_bcon);
			/*
			 * Now, we directly enter A_HOST. So set b_conn = 1
			 * here. In fact, it need host driver to notify us.
			 */
			mvotg->otg_ctrl.b_conn = 1;
			break;
		case OTG_STATE_A_HOST:
			break;
		case OTG_STATE_A_WAIT_VFALL:
			/*
			 * Now, we has exited A_HOST. So set b_conn = 0
			 * here. In fact, it need host driver to notify us.
			 */
			mvotg->otg_ctrl.b_conn = 0;
			mv_otg_set_vbus(otg, 0);
			break;
		case OTG_STATE_A_VBUS_ERR:
			break;
		default:
			break;
		}
		goto run;
	}
}

static irqreturn_t mv_otg_irq(int irq, void *dev)
{
	struct mv_otg *mvotg = dev;
	u32 otgsc;

	otgsc = readl(&mvotg->op_regs->otgsc);
	writel(otgsc, &mvotg->op_regs->otgsc);

	/*
	 * if we have vbus, then the vbus detection for B-device
	 * will be done by mv_otg_inputs_irq().
	 */
	if (mvotg->pdata->vbus)
		if ((otgsc & OTGSC_STS_USB_ID) &&
		    !(otgsc & OTGSC_INTSTS_USB_ID))
			return IRQ_NONE;

	if ((otgsc & mvotg->irq_status) == 0)
		return IRQ_NONE;

	mv_otg_run_state_machine(mvotg, 0);

	return IRQ_HANDLED;
}

static irqreturn_t mv_otg_inputs_irq(int irq, void *dev)
{
	struct mv_otg *mvotg = dev;

	/* The clock may disabled at this time */
	if (!mvotg->active) {
		mv_otg_enable(mvotg);
		mv_otg_init_irq(mvotg);
	}

	mv_otg_run_state_machine(mvotg, 0);

	return IRQ_HANDLED;
}

static ssize_t
get_a_bus_req(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct mv_otg *mvotg = dev_get_drvdata(dev);
	return scnprintf(buf, PAGE_SIZE, "%d\n",
			 mvotg->otg_ctrl.a_bus_req);
}

static ssize_t
set_a_bus_req(struct device *dev, struct device_attribute *attr,
	      const char *buf, size_t count)
{
	struct mv_otg *mvotg = dev_get_drvdata(dev);

	if (count > 2)
		return -1;

	/* We will use this interface to change to A device */
	if (mvotg->phy.state != OTG_STATE_B_IDLE
	    && mvotg->phy.state != OTG_STATE_A_IDLE)
		return -1;

	/* The clock may disabled and we need to set irq for ID detected */
	mv_otg_enable(mvotg);
	mv_otg_init_irq(mvotg);

	if (buf[0] == '1') {
		mvotg->otg_ctrl.a_bus_req = 1;
		mvotg->otg_ctrl.a_bus_drop = 0;
		dev_dbg(&mvotg->pdev->dev,
			"User request: a_bus_req = 1\n");

		if (spin_trylock(&mvotg->wq_lock)) {
			mv_otg_run_state_machine(mvotg, 0);
			spin_unlock(&mvotg->wq_lock);
		}
	}

	return count;
}

static DEVICE_ATTR(a_bus_req, S_IRUGO | S_IWUSR, get_a_bus_req,
		   set_a_bus_req);

static ssize_t
set_a_clr_err(struct device *dev, struct device_attribute *attr,
	      const char *buf, size_t count)
{
	struct mv_otg *mvotg = dev_get_drvdata(dev);
	if (!mvotg->phy.otg->default_a)
		return -1;

	if (count > 2)
		return -1;

	if (buf[0] == '1') {
		mvotg->otg_ctrl.a_clr_err = 1;
		dev_dbg(&mvotg->pdev->dev,
			"User request: a_clr_err = 1\n");
	}

	if (spin_trylock(&mvotg->wq_lock)) {
		mv_otg_run_state_machine(mvotg, 0);
		spin_unlock(&mvotg->wq_lock);
	}

	return count;
}

static DEVICE_ATTR(a_clr_err, S_IWUSR, NULL, set_a_clr_err);

static ssize_t
get_a_bus_drop(struct device *dev, struct device_attribute *attr,
	       char *buf)
{
	struct mv_otg *mvotg = dev_get_drvdata(dev);
	return scnprintf(buf, PAGE_SIZE, "%d\n",
			 mvotg->otg_ctrl.a_bus_drop);
}

static ssize_t
set_a_bus_drop(struct device *dev, struct device_attribute *attr,
	       const char *buf, size_t count)
{
	struct mv_otg *mvotg = dev_get_drvdata(dev);
	if (!mvotg->phy.otg->default_a)
		return -1;

	if (count > 2)
		return -1;

	if (buf[0] == '0') {
		mvotg->otg_ctrl.a_bus_drop = 0;
		dev_dbg(&mvotg->pdev->dev,
			"User request: a_bus_drop = 0\n");
	} else if (buf[0] == '1') {
		mvotg->otg_ctrl.a_bus_drop = 1;
		mvotg->otg_ctrl.a_bus_req = 0;
		dev_dbg(&mvotg->pdev->dev,
			"User request: a_bus_drop = 1\n");
		dev_dbg(&mvotg->pdev->dev,
			"User request: and a_bus_req = 0\n");
	}

	if (spin_trylock(&mvotg->wq_lock)) {
		mv_otg_run_state_machine(mvotg, 0);
		spin_unlock(&mvotg->wq_lock);
	}

	return count;
}

static DEVICE_ATTR(a_bus_drop, S_IRUGO | S_IWUSR,
		   get_a_bus_drop, set_a_bus_drop);

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

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

static int mv_otg_remove(struct platform_device *pdev)
{
	struct mv_otg *mvotg = platform_get_drvdata(pdev);

	sysfs_remove_group(&mvotg->pdev->dev.kobj, &inputs_attr_group);

	if (mvotg->qwork) {
		flush_workqueue(mvotg->qwork);
		destroy_workqueue(mvotg->qwork);
	}

	mv_otg_disable(mvotg);

	usb_remove_phy(&mvotg->phy);

	return 0;
}

static int mv_otg_probe(struct platform_device *pdev)
{
	struct mv_usb_platform_data *pdata = dev_get_platdata(&pdev->dev);
	struct mv_otg *mvotg;
	struct usb_otg *otg;
	struct resource *r;
	int retval = 0, i;

	if (pdata == NULL) {
		dev_err(&pdev->dev, "failed to get platform data\n");
		return -ENODEV;
	}

	mvotg = devm_kzalloc(&pdev->dev, sizeof(*mvotg), GFP_KERNEL);
	if (!mvotg) {
		dev_err(&pdev->dev, "failed to allocate memory!\n");
		return -ENOMEM;
	}

	otg = devm_kzalloc(&pdev->dev, sizeof(*otg), GFP_KERNEL);
	if (!otg)
		return -ENOMEM;

	platform_set_drvdata(pdev, mvotg);

	mvotg->pdev = pdev;
	mvotg->pdata = pdata;

	mvotg->clk = devm_clk_get(&pdev->dev, NULL);
	if (IS_ERR(mvotg->clk))
		return PTR_ERR(mvotg->clk);

	mvotg->qwork = create_singlethread_workqueue("mv_otg_queue");
	if (!mvotg->qwork) {
		dev_dbg(&pdev->dev, "cannot create workqueue for OTG\n");
		return -ENOMEM;
	}

	INIT_DELAYED_WORK(&mvotg->work, mv_otg_work);

	/* OTG common part */
	mvotg->pdev = pdev;
	mvotg->phy.dev = &pdev->dev;
	mvotg->phy.otg = otg;
	mvotg->phy.label = driver_name;
	mvotg->phy.state = OTG_STATE_UNDEFINED;

	otg->phy = &mvotg->phy;
	otg->set_host = mv_otg_set_host;
	otg->set_peripheral = mv_otg_set_peripheral;
	otg->set_vbus = mv_otg_set_vbus;

	for (i = 0; i < OTG_TIMER_NUM; i++)
		init_timer(&mvotg->otg_ctrl.timer[i]);

	r = platform_get_resource_byname(mvotg->pdev,
					 IORESOURCE_MEM, "phyregs");
	if (r == NULL) {
		dev_err(&pdev->dev, "no phy I/O memory resource defined\n");
		retval = -ENODEV;
		goto err_destroy_workqueue;
	}

	mvotg->phy_regs = devm_ioremap(&pdev->dev, r->start, resource_size(r));
	if (mvotg->phy_regs == NULL) {
		dev_err(&pdev->dev, "failed to map phy I/O memory\n");
		retval = -EFAULT;
		goto err_destroy_workqueue;
	}

	r = platform_get_resource_byname(mvotg->pdev,
					 IORESOURCE_MEM, "capregs");
	if (r == NULL) {
		dev_err(&pdev->dev, "no I/O memory resource defined\n");
		retval = -ENODEV;
		goto err_destroy_workqueue;
	}

	mvotg->cap_regs = devm_ioremap(&pdev->dev, r->start, resource_size(r));
	if (mvotg->cap_regs == NULL) {
		dev_err(&pdev->dev, "failed to map I/O memory\n");
		retval = -EFAULT;
		goto err_destroy_workqueue;
	}

	/* we will acces controller register, so enable the udc controller */
	retval = mv_otg_enable_internal(mvotg);
	if (retval) {
		dev_err(&pdev->dev, "mv otg enable error %d\n", retval);
		goto err_destroy_workqueue;
	}

	mvotg->op_regs =
		(struct mv_otg_regs __iomem *) ((unsigned long) mvotg->cap_regs
			+ (readl(mvotg->cap_regs) & CAPLENGTH_MASK));

	if (pdata->id) {
		retval = devm_request_threaded_irq(&pdev->dev, pdata->id->irq,
						NULL, mv_otg_inputs_irq,
						IRQF_ONESHOT, "id", mvotg);
		if (retval) {
			dev_info(&pdev->dev,
				 "Failed to request irq for ID\n");
			pdata->id = NULL;
		}
	}

	if (pdata->vbus) {
		mvotg->clock_gating = 1;
		retval = devm_request_threaded_irq(&pdev->dev, pdata->vbus->irq,
						NULL, mv_otg_inputs_irq,
						IRQF_ONESHOT, "vbus", mvotg);
		if (retval) {
			dev_info(&pdev->dev,
				 "Failed to request irq for VBUS, "
				 "disable clock gating\n");
			mvotg->clock_gating = 0;
			pdata->vbus = NULL;
		}
	}

	if (pdata->disable_otg_clock_gating)
		mvotg->clock_gating = 0;

	mv_otg_reset(mvotg);
	mv_otg_init_irq(mvotg);

	r = platform_get_resource(mvotg->pdev, IORESOURCE_IRQ, 0);
	if (r == NULL) {
		dev_err(&pdev->dev, "no IRQ resource defined\n");
		retval = -ENODEV;
		goto err_disable_clk;
	}

	mvotg->irq = r->start;
	if (devm_request_irq(&pdev->dev, mvotg->irq, mv_otg_irq, IRQF_SHARED,
			driver_name, mvotg)) {
		dev_err(&pdev->dev, "Request irq %d for OTG failed\n",
			mvotg->irq);
		mvotg->irq = 0;
		retval = -ENODEV;
		goto err_disable_clk;
	}

	retval = usb_add_phy(&mvotg->phy, USB_PHY_TYPE_USB2);
	if (retval < 0) {
		dev_err(&pdev->dev, "can't register transceiver, %d\n",
			retval);
		goto err_disable_clk;
	}

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

	spin_lock_init(&mvotg->wq_lock);
	if (spin_trylock(&mvotg->wq_lock)) {
		mv_otg_run_state_machine(mvotg, 2 * HZ);
		spin_unlock(&mvotg->wq_lock);
	}

	dev_info(&pdev->dev,
		 "successful probe OTG device %s clock gating.\n",
		 mvotg->clock_gating ? "with" : "without");

	return 0;

err_remove_phy:
	usb_remove_phy(&mvotg->phy);
err_disable_clk:
	mv_otg_disable_internal(mvotg);
err_destroy_workqueue:
	flush_workqueue(mvotg->qwork);
	destroy_workqueue(mvotg->qwork);

	return retval;
}

#ifdef CONFIG_PM
static int mv_otg_suspend(struct platform_device *pdev, pm_message_t state)
{
	struct mv_otg *mvotg = platform_get_drvdata(pdev);

	if (mvotg->phy.state != OTG_STATE_B_IDLE) {
		dev_info(&pdev->dev,
			 "OTG state is not B_IDLE, it is %d!\n",
			 mvotg->phy.state);
		return -EAGAIN;
	}

	if (!mvotg->clock_gating)
		mv_otg_disable_internal(mvotg);

	return 0;
}

static int mv_otg_resume(struct platform_device *pdev)
{
	struct mv_otg *mvotg = platform_get_drvdata(pdev);
	u32 otgsc;

	if (!mvotg->clock_gating) {
		mv_otg_enable_internal(mvotg);

		otgsc = readl(&mvotg->op_regs->otgsc);
		otgsc |= mvotg->irq_en;
		writel(otgsc, &mvotg->op_regs->otgsc);

		if (spin_trylock(&mvotg->wq_lock)) {
			mv_otg_run_state_machine(mvotg, 0);
			spin_unlock(&mvotg->wq_lock);
		}
	}
	return 0;
}
#endif

static struct platform_driver mv_otg_driver = {
	.probe = mv_otg_probe,
	.remove = mv_otg_remove,
	.driver = {
		   .owner = THIS_MODULE,
		   .name = driver_name,
		   },
#ifdef CONFIG_PM
	.suspend = mv_otg_suspend,
	.resume = mv_otg_resume,
#endif
};
module_platform_driver(mv_otg_driver);