summaryrefslogtreecommitdiffstats
path: root/drivers/usb/dwc3/drd.c
blob: b60b5f7b6dff469b4376080a31c7061b7102b2b6 (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
// SPDX-License-Identifier: GPL-2.0
/*
 * drd.c - DesignWare USB3 DRD Controller Dual-role support
 *
 * Copyright (C) 2017 Texas Instruments Incorporated - https://www.ti.com
 *
 * Authors: Roger Quadros <rogerq@ti.com>
 */

#include <linux/extcon.h>
#include <linux/of_graph.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/property.h>

#include "debug.h"
#include "core.h"
#include "gadget.h"

static void dwc3_otg_disable_events(struct dwc3 *dwc, u32 disable_mask)
{
	u32 reg = dwc3_readl(dwc->regs, DWC3_OEVTEN);

	reg &= ~(disable_mask);
	dwc3_writel(dwc->regs, DWC3_OEVTEN, reg);
}

static void dwc3_otg_enable_events(struct dwc3 *dwc, u32 enable_mask)
{
	u32 reg = dwc3_readl(dwc->regs, DWC3_OEVTEN);

	reg |= (enable_mask);
	dwc3_writel(dwc->regs, DWC3_OEVTEN, reg);
}

static void dwc3_otg_clear_events(struct dwc3 *dwc)
{
	u32 reg = dwc3_readl(dwc->regs, DWC3_OEVT);

	dwc3_writel(dwc->regs, DWC3_OEVTEN, reg);
}

#define DWC3_OTG_ALL_EVENTS	(DWC3_OEVTEN_XHCIRUNSTPSETEN | \
		DWC3_OEVTEN_DEVRUNSTPSETEN | DWC3_OEVTEN_HIBENTRYEN | \
		DWC3_OEVTEN_CONIDSTSCHNGEN | DWC3_OEVTEN_HRRCONFNOTIFEN | \
		DWC3_OEVTEN_HRRINITNOTIFEN | DWC3_OEVTEN_ADEVIDLEEN | \
		DWC3_OEVTEN_ADEVBHOSTENDEN | DWC3_OEVTEN_ADEVHOSTEN | \
		DWC3_OEVTEN_ADEVHNPCHNGEN | DWC3_OEVTEN_ADEVSRPDETEN | \
		DWC3_OEVTEN_ADEVSESSENDDETEN | DWC3_OEVTEN_BDEVBHOSTENDEN | \
		DWC3_OEVTEN_BDEVHNPCHNGEN | DWC3_OEVTEN_BDEVSESSVLDDETEN | \
		DWC3_OEVTEN_BDEVVBUSCHNGEN)

static irqreturn_t dwc3_otg_thread_irq(int irq, void *_dwc)
{
	struct dwc3 *dwc = _dwc;

	spin_lock(&dwc->lock);
	if (dwc->otg_restart_host) {
		dwc3_otg_host_init(dwc);
		dwc->otg_restart_host = false;
	}

	spin_unlock(&dwc->lock);

	dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_OTG);

	return IRQ_HANDLED;
}

static irqreturn_t dwc3_otg_irq(int irq, void *_dwc)
{
	u32 reg;
	struct dwc3 *dwc = _dwc;
	irqreturn_t ret = IRQ_NONE;

	reg = dwc3_readl(dwc->regs, DWC3_OEVT);
	if (reg) {
		/* ignore non OTG events, we can't disable them in OEVTEN */
		if (!(reg & DWC3_OTG_ALL_EVENTS)) {
			dwc3_writel(dwc->regs, DWC3_OEVT, reg);
			return IRQ_NONE;
		}

		if (dwc->current_otg_role == DWC3_OTG_ROLE_HOST &&
		    !(reg & DWC3_OEVT_DEVICEMODE))
			dwc->otg_restart_host = true;
		dwc3_writel(dwc->regs, DWC3_OEVT, reg);
		ret = IRQ_WAKE_THREAD;
	}

	return ret;
}

static void dwc3_otgregs_init(struct dwc3 *dwc)
{
	u32 reg;

	/*
	 * Prevent host/device reset from resetting OTG core.
	 * If we don't do this then xhci_reset (USBCMD.HCRST) will reset
	 * the signal outputs sent to the PHY, the OTG FSM logic of the
	 * core and also the resets to the VBUS filters inside the core.
	 */
	reg = dwc3_readl(dwc->regs, DWC3_OCFG);
	reg |= DWC3_OCFG_SFTRSTMASK;
	dwc3_writel(dwc->regs, DWC3_OCFG, reg);

	/* Disable hibernation for simplicity */
	reg = dwc3_readl(dwc->regs, DWC3_GCTL);
	reg &= ~DWC3_GCTL_GBLHIBERNATIONEN;
	dwc3_writel(dwc->regs, DWC3_GCTL, reg);

	/*
	 * Initialize OTG registers as per
	 * Figure 11-4 OTG Driver Overall Programming Flow
	 */
	/* OCFG.SRPCap = 0, OCFG.HNPCap = 0 */
	reg = dwc3_readl(dwc->regs, DWC3_OCFG);
	reg &= ~(DWC3_OCFG_SRPCAP | DWC3_OCFG_HNPCAP);
	dwc3_writel(dwc->regs, DWC3_OCFG, reg);
	/* OEVT = FFFF */
	dwc3_otg_clear_events(dwc);
	/* OEVTEN = 0 */
	dwc3_otg_disable_events(dwc, DWC3_OTG_ALL_EVENTS);
	/* OEVTEN.ConIDStsChngEn = 1. Instead we enable all events */
	dwc3_otg_enable_events(dwc, DWC3_OTG_ALL_EVENTS);
	/*
	 * OCTL.PeriMode = 1, OCTL.DevSetHNPEn = 0, OCTL.HstSetHNPEn = 0,
	 * OCTL.HNPReq = 0
	 */
	reg = dwc3_readl(dwc->regs, DWC3_OCTL);
	reg |= DWC3_OCTL_PERIMODE;
	reg &= ~(DWC3_OCTL_DEVSETHNPEN | DWC3_OCTL_HSTSETHNPEN |
		 DWC3_OCTL_HNPREQ);
	dwc3_writel(dwc->regs, DWC3_OCTL, reg);
}

static int dwc3_otg_get_irq(struct dwc3 *dwc)
{
	struct platform_device *dwc3_pdev = to_platform_device(dwc->dev);
	int irq;

	irq = platform_get_irq_byname_optional(dwc3_pdev, "otg");
	if (irq > 0)
		goto out;

	if (irq == -EPROBE_DEFER)
		goto out;

	irq = platform_get_irq_byname_optional(dwc3_pdev, "dwc_usb3");
	if (irq > 0)
		goto out;

	if (irq == -EPROBE_DEFER)
		goto out;

	irq = platform_get_irq(dwc3_pdev, 0);
	if (irq > 0)
		goto out;

	if (!irq)
		irq = -EINVAL;

out:
	return irq;
}

void dwc3_otg_init(struct dwc3 *dwc)
{
	u32 reg;

	/*
	 * As per Figure 11-4 OTG Driver Overall Programming Flow,
	 * block "Initialize GCTL for OTG operation".
	 */
	/* GCTL.PrtCapDir=2'b11 */
	dwc3_set_prtcap(dwc, DWC3_GCTL_PRTCAP_OTG);
	/* GUSB2PHYCFG0.SusPHY=0 */
	reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
	reg &= ~DWC3_GUSB2PHYCFG_SUSPHY;
	dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);

	/* Initialize OTG registers */
	dwc3_otgregs_init(dwc);
}

void dwc3_otg_exit(struct dwc3 *dwc)
{
	/* disable all OTG IRQs */
	dwc3_otg_disable_events(dwc, DWC3_OTG_ALL_EVENTS);
	/* clear all events */
	dwc3_otg_clear_events(dwc);
}

/* should be called before Host controller driver is started */
void dwc3_otg_host_init(struct dwc3 *dwc)
{
	u32 reg;

	/* As per Figure 11-10 A-Device Flow Diagram */
	/* OCFG.HNPCap = 0, OCFG.SRPCap = 0. Already 0 */

	/*
	 * OCTL.PeriMode=0, OCTL.TermSelDLPulse = 0,
	 * OCTL.DevSetHNPEn = 0, OCTL.HstSetHNPEn = 0
	 */
	reg = dwc3_readl(dwc->regs, DWC3_OCTL);
	reg &= ~(DWC3_OCTL_PERIMODE | DWC3_OCTL_TERMSELIDPULSE |
			DWC3_OCTL_DEVSETHNPEN | DWC3_OCTL_HSTSETHNPEN);
	dwc3_writel(dwc->regs, DWC3_OCTL, reg);

	/*
	 * OCFG.DisPrtPwrCutoff = 0/1
	 */
	reg = dwc3_readl(dwc->regs, DWC3_OCFG);
	reg &= ~DWC3_OCFG_DISPWRCUTTOFF;
	dwc3_writel(dwc->regs, DWC3_OCFG, reg);

	/*
	 * OCFG.SRPCap = 1, OCFG.HNPCap = GHWPARAMS6.HNP_CAP
	 * We don't want SRP/HNP for simple dual-role so leave
	 * these disabled.
	 */

	/*
	 * OEVTEN.OTGADevHostEvntEn = 1
	 * OEVTEN.OTGADevSessEndDetEvntEn = 1
	 * We don't want HNP/role-swap so leave these disabled.
	 */

	/* GUSB2PHYCFG.ULPIAutoRes = 1/0, GUSB2PHYCFG.SusPHY = 1 */
	if (!dwc->dis_u2_susphy_quirk) {
		reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
		reg |= DWC3_GUSB2PHYCFG_SUSPHY;
		dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
	}

	/* Set Port Power to enable VBUS: OCTL.PrtPwrCtl = 1 */
	reg = dwc3_readl(dwc->regs, DWC3_OCTL);
	reg |= DWC3_OCTL_PRTPWRCTL;
	dwc3_writel(dwc->regs, DWC3_OCTL, reg);
}

/* should be called after Host controller driver is stopped */
static void dwc3_otg_host_exit(struct dwc3 *dwc)
{
	u32 reg;

	/*
	 * Exit from A-device flow as per
	 * Figure 11-4 OTG Driver Overall Programming Flow
	 */

	/*
	 * OEVTEN.OTGADevBHostEndEvntEn=0, OEVTEN.OTGADevHNPChngEvntEn=0
	 * OEVTEN.OTGADevSessEndDetEvntEn=0,
	 * OEVTEN.OTGADevHostEvntEn = 0
	 * But we don't disable any OTG events
	 */

	/* OCTL.HstSetHNPEn = 0, OCTL.PrtPwrCtl=0 */
	reg = dwc3_readl(dwc->regs, DWC3_OCTL);
	reg &= ~(DWC3_OCTL_HSTSETHNPEN | DWC3_OCTL_PRTPWRCTL);
	dwc3_writel(dwc->regs, DWC3_OCTL, reg);
}

/* should be called before the gadget controller driver is started */
static void dwc3_otg_device_init(struct dwc3 *dwc)
{
	u32 reg;

	/* As per Figure 11-20 B-Device Flow Diagram */

	/*
	 * OCFG.HNPCap = GHWPARAMS6.HNP_CAP, OCFG.SRPCap = 1
	 * but we keep them 0 for simple dual-role operation.
	 */
	reg = dwc3_readl(dwc->regs, DWC3_OCFG);
	/* OCFG.OTGSftRstMsk = 0/1 */
	reg |= DWC3_OCFG_SFTRSTMASK;
	dwc3_writel(dwc->regs, DWC3_OCFG, reg);
	/*
	 * OCTL.PeriMode = 1
	 * OCTL.TermSelDLPulse = 0/1, OCTL.HNPReq = 0
	 * OCTL.DevSetHNPEn = 0, OCTL.HstSetHNPEn = 0
	 */
	reg = dwc3_readl(dwc->regs, DWC3_OCTL);
	reg |= DWC3_OCTL_PERIMODE;
	reg &= ~(DWC3_OCTL_TERMSELIDPULSE | DWC3_OCTL_HNPREQ |
			DWC3_OCTL_DEVSETHNPEN | DWC3_OCTL_HSTSETHNPEN);
	dwc3_writel(dwc->regs, DWC3_OCTL, reg);
	/* OEVTEN.OTGBDevSesVldDetEvntEn = 1 */
	dwc3_otg_enable_events(dwc, DWC3_OEVTEN_BDEVSESSVLDDETEN);
	/* GUSB2PHYCFG.ULPIAutoRes = 0, GUSB2PHYCFG0.SusPHY = 1 */
	if (!dwc->dis_u2_susphy_quirk) {
		reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
		reg |= DWC3_GUSB2PHYCFG_SUSPHY;
		dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
	}
	/* GCTL.GblHibernationEn = 0. Already 0. */
}

/* should be called after the gadget controller driver is stopped */
static void dwc3_otg_device_exit(struct dwc3 *dwc)
{
	u32 reg;

	/*
	 * Exit from B-device flow as per
	 * Figure 11-4 OTG Driver Overall Programming Flow
	 */

	/*
	 * OEVTEN.OTGBDevHNPChngEvntEn = 0
	 * OEVTEN.OTGBDevVBusChngEvntEn = 0
	 * OEVTEN.OTGBDevBHostEndEvntEn = 0
	 */
	dwc3_otg_disable_events(dwc, DWC3_OEVTEN_BDEVHNPCHNGEN |
				DWC3_OEVTEN_BDEVVBUSCHNGEN |
				DWC3_OEVTEN_BDEVBHOSTENDEN);

	/* OCTL.DevSetHNPEn = 0, OCTL.HNPReq = 0, OCTL.PeriMode=1 */
	reg = dwc3_readl(dwc->regs, DWC3_OCTL);
	reg &= ~(DWC3_OCTL_DEVSETHNPEN | DWC3_OCTL_HNPREQ);
	reg |= DWC3_OCTL_PERIMODE;
	dwc3_writel(dwc->regs, DWC3_OCTL, reg);
}

void dwc3_otg_update(struct dwc3 *dwc, bool ignore_idstatus)
{
	int ret;
	u32 reg;
	int id;
	unsigned long flags;

	if (dwc->dr_mode != USB_DR_MODE_OTG)
		return;

	/* don't do anything if debug user changed role to not OTG */
	if (dwc->current_dr_role != DWC3_GCTL_PRTCAP_OTG)
		return;

	if (!ignore_idstatus) {
		reg = dwc3_readl(dwc->regs, DWC3_OSTS);
		id = !!(reg & DWC3_OSTS_CONIDSTS);

		dwc->desired_otg_role = id ? DWC3_OTG_ROLE_DEVICE :
					DWC3_OTG_ROLE_HOST;
	}

	if (dwc->desired_otg_role == dwc->current_otg_role)
		return;

	switch (dwc->current_otg_role) {
	case DWC3_OTG_ROLE_HOST:
		dwc3_host_exit(dwc);
		spin_lock_irqsave(&dwc->lock, flags);
		dwc3_otg_host_exit(dwc);
		spin_unlock_irqrestore(&dwc->lock, flags);
		break;
	case DWC3_OTG_ROLE_DEVICE:
		dwc3_gadget_exit(dwc);
		spin_lock_irqsave(&dwc->lock, flags);
		dwc3_event_buffers_cleanup(dwc);
		dwc3_otg_device_exit(dwc);
		spin_unlock_irqrestore(&dwc->lock, flags);
		break;
	default:
		break;
	}

	spin_lock_irqsave(&dwc->lock, flags);

	dwc->current_otg_role = dwc->desired_otg_role;

	spin_unlock_irqrestore(&dwc->lock, flags);

	switch (dwc->desired_otg_role) {
	case DWC3_OTG_ROLE_HOST:
		spin_lock_irqsave(&dwc->lock, flags);
		dwc3_otgregs_init(dwc);
		dwc3_otg_host_init(dwc);
		spin_unlock_irqrestore(&dwc->lock, flags);
		ret = dwc3_host_init(dwc);
		if (ret) {
			dev_err(dwc->dev, "failed to initialize host\n");
		} else {
			if (dwc->usb2_phy)
				otg_set_vbus(dwc->usb2_phy->otg, true);
			if (dwc->usb2_generic_phy)
				phy_set_mode(dwc->usb2_generic_phy,
					     PHY_MODE_USB_HOST);
		}
		break;
	case DWC3_OTG_ROLE_DEVICE:
		spin_lock_irqsave(&dwc->lock, flags);
		dwc3_otgregs_init(dwc);
		dwc3_otg_device_init(dwc);
		dwc3_event_buffers_setup(dwc);
		spin_unlock_irqrestore(&dwc->lock, flags);

		if (dwc->usb2_phy)
			otg_set_vbus(dwc->usb2_phy->otg, false);
		if (dwc->usb2_generic_phy)
			phy_set_mode(dwc->usb2_generic_phy,
				     PHY_MODE_USB_DEVICE);
		ret = dwc3_gadget_init(dwc);
		if (ret)
			dev_err(dwc->dev, "failed to initialize peripheral\n");
		break;
	default:
		break;
	}
}

static void dwc3_drd_update(struct dwc3 *dwc)
{
	int id;

	if (dwc->edev) {
		id = extcon_get_state(dwc->edev, EXTCON_USB_HOST);
		if (id < 0)
			id = 0;
		dwc3_set_mode(dwc, id ?
			      DWC3_GCTL_PRTCAP_HOST :
			      DWC3_GCTL_PRTCAP_DEVICE);
	}
}

static int dwc3_drd_notifier(struct notifier_block *nb,
			     unsigned long event, void *ptr)
{
	struct dwc3 *dwc = container_of(nb, struct dwc3, edev_nb);

	dwc3_set_mode(dwc, event ?
		      DWC3_GCTL_PRTCAP_HOST :
		      DWC3_GCTL_PRTCAP_DEVICE);

	return NOTIFY_DONE;
}

static struct extcon_dev *dwc3_get_extcon(struct dwc3 *dwc)
{
	struct device *dev = dwc->dev;
	struct device_node *np_phy;
	struct extcon_dev *edev = NULL;
	const char *name;

	if (device_property_read_bool(dev, "extcon"))
		return extcon_get_edev_by_phandle(dev, 0);

	/*
	 * Device tree platforms should get extcon via phandle.
	 * On ACPI platforms, we get the name from a device property.
	 * This device property is for kernel internal use only and
	 * is expected to be set by the glue code.
	 */
	if (device_property_read_string(dev, "linux,extcon-name", &name) == 0) {
		edev = extcon_get_extcon_dev(name);
		if (!edev)
			return ERR_PTR(-EPROBE_DEFER);

		return edev;
	}

	/*
	 * Try to get an extcon device from the USB PHY controller's "port"
	 * node. Check if it has the "port" node first, to avoid printing the
	 * error message from underlying code, as it's a valid case: extcon
	 * device (and "port" node) may be missing in case of "usb-role-switch"
	 * or OTG mode.
	 */
	np_phy = of_parse_phandle(dev->of_node, "phys", 0);
	if (of_graph_is_present(np_phy)) {
		struct device_node *np_conn;

		np_conn = of_graph_get_remote_node(np_phy, -1, -1);
		if (np_conn)
			edev = extcon_find_edev_by_node(np_conn);
		of_node_put(np_conn);
	}
	of_node_put(np_phy);

	return edev;
}

#if IS_ENABLED(CONFIG_USB_ROLE_SWITCH)
#define ROLE_SWITCH 1
static int dwc3_usb_role_switch_set(struct usb_role_switch *sw,
				    enum usb_role role)
{
	struct dwc3 *dwc = usb_role_switch_get_drvdata(sw);
	u32 mode;

	switch (role) {
	case USB_ROLE_HOST:
		mode = DWC3_GCTL_PRTCAP_HOST;
		break;
	case USB_ROLE_DEVICE:
		mode = DWC3_GCTL_PRTCAP_DEVICE;
		break;
	default:
		if (dwc->role_switch_default_mode == USB_DR_MODE_HOST)
			mode = DWC3_GCTL_PRTCAP_HOST;
		else
			mode = DWC3_GCTL_PRTCAP_DEVICE;
		break;
	}

	dwc3_set_mode(dwc, mode);
	return 0;
}

static enum usb_role dwc3_usb_role_switch_get(struct usb_role_switch *sw)
{
	struct dwc3 *dwc = usb_role_switch_get_drvdata(sw);
	unsigned long flags;
	enum usb_role role;

	spin_lock_irqsave(&dwc->lock, flags);
	switch (dwc->current_dr_role) {
	case DWC3_GCTL_PRTCAP_HOST:
		role = USB_ROLE_HOST;
		break;
	case DWC3_GCTL_PRTCAP_DEVICE:
		role = USB_ROLE_DEVICE;
		break;
	case DWC3_GCTL_PRTCAP_OTG:
		role = dwc->current_otg_role;
		break;
	default:
		if (dwc->role_switch_default_mode == USB_DR_MODE_HOST)
			role = USB_ROLE_HOST;
		else
			role = USB_ROLE_DEVICE;
		break;
	}
	spin_unlock_irqrestore(&dwc->lock, flags);
	return role;
}

static int dwc3_setup_role_switch(struct dwc3 *dwc)
{
	struct usb_role_switch_desc dwc3_role_switch = {NULL};
	u32 mode;

	dwc->role_switch_default_mode = usb_get_role_switch_default_mode(dwc->dev);
	if (dwc->role_switch_default_mode == USB_DR_MODE_HOST) {
		mode = DWC3_GCTL_PRTCAP_HOST;
	} else {
		dwc->role_switch_default_mode = USB_DR_MODE_PERIPHERAL;
		mode = DWC3_GCTL_PRTCAP_DEVICE;
	}

	dwc3_role_switch.fwnode = dev_fwnode(dwc->dev);
	dwc3_role_switch.set = dwc3_usb_role_switch_set;
	dwc3_role_switch.get = dwc3_usb_role_switch_get;
	dwc3_role_switch.driver_data = dwc;
	dwc->role_sw = usb_role_switch_register(dwc->dev, &dwc3_role_switch);
	if (IS_ERR(dwc->role_sw))
		return PTR_ERR(dwc->role_sw);

	if (dwc->dev->of_node) {
		/* populate connector entry */
		int ret = devm_of_platform_populate(dwc->dev);

		if (ret) {
			usb_role_switch_unregister(dwc->role_sw);
			dwc->role_sw = NULL;
			dev_err(dwc->dev, "DWC3 platform devices creation failed: %i\n", ret);
			return ret;
		}
	}

	dwc3_set_mode(dwc, mode);
	return 0;
}
#else
#define ROLE_SWITCH 0
#define dwc3_setup_role_switch(x) 0
#endif

int dwc3_drd_init(struct dwc3 *dwc)
{
	int ret, irq;

	dwc->edev = dwc3_get_extcon(dwc);
	if (IS_ERR(dwc->edev))
		return PTR_ERR(dwc->edev);

	if (ROLE_SWITCH &&
	    device_property_read_bool(dwc->dev, "usb-role-switch")) {
		ret = dwc3_setup_role_switch(dwc);
		if (ret < 0)
			return ret;
	} else if (dwc->edev) {
		dwc->edev_nb.notifier_call = dwc3_drd_notifier;
		ret = extcon_register_notifier(dwc->edev, EXTCON_USB_HOST,
					       &dwc->edev_nb);
		if (ret < 0) {
			dev_err(dwc->dev, "couldn't register cable notifier\n");
			return ret;
		}

		dwc3_drd_update(dwc);
	} else {
		dwc3_set_prtcap(dwc, DWC3_GCTL_PRTCAP_OTG);

		/* use OTG block to get ID event */
		irq = dwc3_otg_get_irq(dwc);
		if (irq < 0)
			return irq;

		dwc->otg_irq = irq;

		/* disable all OTG IRQs */
		dwc3_otg_disable_events(dwc, DWC3_OTG_ALL_EVENTS);
		/* clear all events */
		dwc3_otg_clear_events(dwc);

		ret = request_threaded_irq(dwc->otg_irq, dwc3_otg_irq,
					   dwc3_otg_thread_irq,
					   IRQF_SHARED, "dwc3-otg", dwc);
		if (ret) {
			dev_err(dwc->dev, "failed to request irq #%d --> %d\n",
				dwc->otg_irq, ret);
			ret = -ENODEV;
			return ret;
		}

		dwc3_otg_init(dwc);
		dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_OTG);
	}

	return 0;
}

void dwc3_drd_exit(struct dwc3 *dwc)
{
	unsigned long flags;

	if (dwc->role_sw)
		usb_role_switch_unregister(dwc->role_sw);

	if (dwc->edev)
		extcon_unregister_notifier(dwc->edev, EXTCON_USB_HOST,
					   &dwc->edev_nb);

	cancel_work_sync(&dwc->drd_work);

	/* debug user might have changed role, clean based on current role */
	switch (dwc->current_dr_role) {
	case DWC3_GCTL_PRTCAP_HOST:
		dwc3_host_exit(dwc);
		break;
	case DWC3_GCTL_PRTCAP_DEVICE:
		dwc3_gadget_exit(dwc);
		dwc3_event_buffers_cleanup(dwc);
		break;
	case DWC3_GCTL_PRTCAP_OTG:
		dwc3_otg_exit(dwc);
		spin_lock_irqsave(&dwc->lock, flags);
		dwc->desired_otg_role = DWC3_OTG_ROLE_IDLE;
		spin_unlock_irqrestore(&dwc->lock, flags);
		dwc3_otg_update(dwc, 1);
		break;
	default:
		break;
	}

	if (dwc->otg_irq)
		free_irq(dwc->otg_irq, dwc);
}