xref: /kernel/linux/linux-5.10/drivers/usb/dwc3/drd.c (revision 8c2ecf20)
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * drd.c - DesignWare USB3 DRD Controller Dual-role support
4 *
5 * Copyright (C) 2017 Texas Instruments Incorporated - https://www.ti.com
6 *
7 * Authors: Roger Quadros <rogerq@ti.com>
8 */
9
10#include <linux/extcon.h>
11#include <linux/of_graph.h>
12#include <linux/platform_device.h>
13#include <linux/property.h>
14
15#include "debug.h"
16#include "core.h"
17#include "gadget.h"
18
19static void dwc3_otg_disable_events(struct dwc3 *dwc, u32 disable_mask)
20{
21	u32 reg = dwc3_readl(dwc->regs, DWC3_OEVTEN);
22
23	reg &= ~(disable_mask);
24	dwc3_writel(dwc->regs, DWC3_OEVTEN, reg);
25}
26
27static void dwc3_otg_enable_events(struct dwc3 *dwc, u32 enable_mask)
28{
29	u32 reg = dwc3_readl(dwc->regs, DWC3_OEVTEN);
30
31	reg |= (enable_mask);
32	dwc3_writel(dwc->regs, DWC3_OEVTEN, reg);
33}
34
35static void dwc3_otg_clear_events(struct dwc3 *dwc)
36{
37	u32 reg = dwc3_readl(dwc->regs, DWC3_OEVT);
38
39	dwc3_writel(dwc->regs, DWC3_OEVTEN, reg);
40}
41
42#define DWC3_OTG_ALL_EVENTS	(DWC3_OEVTEN_XHCIRUNSTPSETEN | \
43		DWC3_OEVTEN_DEVRUNSTPSETEN | DWC3_OEVTEN_HIBENTRYEN | \
44		DWC3_OEVTEN_CONIDSTSCHNGEN | DWC3_OEVTEN_HRRCONFNOTIFEN | \
45		DWC3_OEVTEN_HRRINITNOTIFEN | DWC3_OEVTEN_ADEVIDLEEN | \
46		DWC3_OEVTEN_ADEVBHOSTENDEN | DWC3_OEVTEN_ADEVHOSTEN | \
47		DWC3_OEVTEN_ADEVHNPCHNGEN | DWC3_OEVTEN_ADEVSRPDETEN | \
48		DWC3_OEVTEN_ADEVSESSENDDETEN | DWC3_OEVTEN_BDEVBHOSTENDEN | \
49		DWC3_OEVTEN_BDEVHNPCHNGEN | DWC3_OEVTEN_BDEVSESSVLDDETEN | \
50		DWC3_OEVTEN_BDEVVBUSCHNGEN)
51
52static irqreturn_t dwc3_otg_thread_irq(int irq, void *_dwc)
53{
54	struct dwc3 *dwc = _dwc;
55
56	spin_lock(&dwc->lock);
57	if (dwc->otg_restart_host) {
58		dwc3_otg_host_init(dwc);
59		dwc->otg_restart_host = false;
60	}
61
62	spin_unlock(&dwc->lock);
63
64	dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_OTG);
65
66	return IRQ_HANDLED;
67}
68
69static irqreturn_t dwc3_otg_irq(int irq, void *_dwc)
70{
71	u32 reg;
72	struct dwc3 *dwc = _dwc;
73	irqreturn_t ret = IRQ_NONE;
74
75	reg = dwc3_readl(dwc->regs, DWC3_OEVT);
76	if (reg) {
77		/* ignore non OTG events, we can't disable them in OEVTEN */
78		if (!(reg & DWC3_OTG_ALL_EVENTS)) {
79			dwc3_writel(dwc->regs, DWC3_OEVT, reg);
80			return IRQ_NONE;
81		}
82
83		if (dwc->current_otg_role == DWC3_OTG_ROLE_HOST &&
84		    !(reg & DWC3_OEVT_DEVICEMODE))
85			dwc->otg_restart_host = true;
86		dwc3_writel(dwc->regs, DWC3_OEVT, reg);
87		ret = IRQ_WAKE_THREAD;
88	}
89
90	return ret;
91}
92
93static void dwc3_otgregs_init(struct dwc3 *dwc)
94{
95	u32 reg;
96
97	/*
98	 * Prevent host/device reset from resetting OTG core.
99	 * If we don't do this then xhci_reset (USBCMD.HCRST) will reset
100	 * the signal outputs sent to the PHY, the OTG FSM logic of the
101	 * core and also the resets to the VBUS filters inside the core.
102	 */
103	reg = dwc3_readl(dwc->regs, DWC3_OCFG);
104	reg |= DWC3_OCFG_SFTRSTMASK;
105	dwc3_writel(dwc->regs, DWC3_OCFG, reg);
106
107	/* Disable hibernation for simplicity */
108	reg = dwc3_readl(dwc->regs, DWC3_GCTL);
109	reg &= ~DWC3_GCTL_GBLHIBERNATIONEN;
110	dwc3_writel(dwc->regs, DWC3_GCTL, reg);
111
112	/*
113	 * Initialize OTG registers as per
114	 * Figure 11-4 OTG Driver Overall Programming Flow
115	 */
116	/* OCFG.SRPCap = 0, OCFG.HNPCap = 0 */
117	reg = dwc3_readl(dwc->regs, DWC3_OCFG);
118	reg &= ~(DWC3_OCFG_SRPCAP | DWC3_OCFG_HNPCAP);
119	dwc3_writel(dwc->regs, DWC3_OCFG, reg);
120	/* OEVT = FFFF */
121	dwc3_otg_clear_events(dwc);
122	/* OEVTEN = 0 */
123	dwc3_otg_disable_events(dwc, DWC3_OTG_ALL_EVENTS);
124	/* OEVTEN.ConIDStsChngEn = 1. Instead we enable all events */
125	dwc3_otg_enable_events(dwc, DWC3_OTG_ALL_EVENTS);
126	/*
127	 * OCTL.PeriMode = 1, OCTL.DevSetHNPEn = 0, OCTL.HstSetHNPEn = 0,
128	 * OCTL.HNPReq = 0
129	 */
130	reg = dwc3_readl(dwc->regs, DWC3_OCTL);
131	reg |= DWC3_OCTL_PERIMODE;
132	reg &= ~(DWC3_OCTL_DEVSETHNPEN | DWC3_OCTL_HSTSETHNPEN |
133		 DWC3_OCTL_HNPREQ);
134	dwc3_writel(dwc->regs, DWC3_OCTL, reg);
135}
136
137static int dwc3_otg_get_irq(struct dwc3 *dwc)
138{
139	struct platform_device *dwc3_pdev = to_platform_device(dwc->dev);
140	int irq;
141
142	irq = platform_get_irq_byname_optional(dwc3_pdev, "otg");
143	if (irq > 0)
144		goto out;
145
146	if (irq == -EPROBE_DEFER)
147		goto out;
148
149	irq = platform_get_irq_byname_optional(dwc3_pdev, "dwc_usb3");
150	if (irq > 0)
151		goto out;
152
153	if (irq == -EPROBE_DEFER)
154		goto out;
155
156	irq = platform_get_irq(dwc3_pdev, 0);
157	if (irq > 0)
158		goto out;
159
160	if (!irq)
161		irq = -EINVAL;
162
163out:
164	return irq;
165}
166
167void dwc3_otg_init(struct dwc3 *dwc)
168{
169	u32 reg;
170
171	/*
172	 * As per Figure 11-4 OTG Driver Overall Programming Flow,
173	 * block "Initialize GCTL for OTG operation".
174	 */
175	/* GCTL.PrtCapDir=2'b11 */
176	dwc3_set_prtcap(dwc, DWC3_GCTL_PRTCAP_OTG);
177	/* GUSB2PHYCFG0.SusPHY=0 */
178	reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
179	reg &= ~DWC3_GUSB2PHYCFG_SUSPHY;
180	dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
181
182	/* Initialize OTG registers */
183	dwc3_otgregs_init(dwc);
184}
185
186void dwc3_otg_exit(struct dwc3 *dwc)
187{
188	/* disable all OTG IRQs */
189	dwc3_otg_disable_events(dwc, DWC3_OTG_ALL_EVENTS);
190	/* clear all events */
191	dwc3_otg_clear_events(dwc);
192}
193
194/* should be called before Host controller driver is started */
195void dwc3_otg_host_init(struct dwc3 *dwc)
196{
197	u32 reg;
198
199	/* As per Figure 11-10 A-Device Flow Diagram */
200	/* OCFG.HNPCap = 0, OCFG.SRPCap = 0. Already 0 */
201
202	/*
203	 * OCTL.PeriMode=0, OCTL.TermSelDLPulse = 0,
204	 * OCTL.DevSetHNPEn = 0, OCTL.HstSetHNPEn = 0
205	 */
206	reg = dwc3_readl(dwc->regs, DWC3_OCTL);
207	reg &= ~(DWC3_OCTL_PERIMODE | DWC3_OCTL_TERMSELIDPULSE |
208			DWC3_OCTL_DEVSETHNPEN | DWC3_OCTL_HSTSETHNPEN);
209	dwc3_writel(dwc->regs, DWC3_OCTL, reg);
210
211	/*
212	 * OCFG.DisPrtPwrCutoff = 0/1
213	 */
214	reg = dwc3_readl(dwc->regs, DWC3_OCFG);
215	reg &= ~DWC3_OCFG_DISPWRCUTTOFF;
216	dwc3_writel(dwc->regs, DWC3_OCFG, reg);
217
218	/*
219	 * OCFG.SRPCap = 1, OCFG.HNPCap = GHWPARAMS6.HNP_CAP
220	 * We don't want SRP/HNP for simple dual-role so leave
221	 * these disabled.
222	 */
223
224	/*
225	 * OEVTEN.OTGADevHostEvntEn = 1
226	 * OEVTEN.OTGADevSessEndDetEvntEn = 1
227	 * We don't want HNP/role-swap so leave these disabled.
228	 */
229
230	/* GUSB2PHYCFG.ULPIAutoRes = 1/0, GUSB2PHYCFG.SusPHY = 1 */
231	if (!dwc->dis_u2_susphy_quirk) {
232		reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
233		reg |= DWC3_GUSB2PHYCFG_SUSPHY;
234		dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
235	}
236
237	/* Set Port Power to enable VBUS: OCTL.PrtPwrCtl = 1 */
238	reg = dwc3_readl(dwc->regs, DWC3_OCTL);
239	reg |= DWC3_OCTL_PRTPWRCTL;
240	dwc3_writel(dwc->regs, DWC3_OCTL, reg);
241}
242
243/* should be called after Host controller driver is stopped */
244static void dwc3_otg_host_exit(struct dwc3 *dwc)
245{
246	u32 reg;
247
248	/*
249	 * Exit from A-device flow as per
250	 * Figure 11-4 OTG Driver Overall Programming Flow
251	 */
252
253	/*
254	 * OEVTEN.OTGADevBHostEndEvntEn=0, OEVTEN.OTGADevHNPChngEvntEn=0
255	 * OEVTEN.OTGADevSessEndDetEvntEn=0,
256	 * OEVTEN.OTGADevHostEvntEn = 0
257	 * But we don't disable any OTG events
258	 */
259
260	/* OCTL.HstSetHNPEn = 0, OCTL.PrtPwrCtl=0 */
261	reg = dwc3_readl(dwc->regs, DWC3_OCTL);
262	reg &= ~(DWC3_OCTL_HSTSETHNPEN | DWC3_OCTL_PRTPWRCTL);
263	dwc3_writel(dwc->regs, DWC3_OCTL, reg);
264}
265
266/* should be called before the gadget controller driver is started */
267static void dwc3_otg_device_init(struct dwc3 *dwc)
268{
269	u32 reg;
270
271	/* As per Figure 11-20 B-Device Flow Diagram */
272
273	/*
274	 * OCFG.HNPCap = GHWPARAMS6.HNP_CAP, OCFG.SRPCap = 1
275	 * but we keep them 0 for simple dual-role operation.
276	 */
277	reg = dwc3_readl(dwc->regs, DWC3_OCFG);
278	/* OCFG.OTGSftRstMsk = 0/1 */
279	reg |= DWC3_OCFG_SFTRSTMASK;
280	dwc3_writel(dwc->regs, DWC3_OCFG, reg);
281	/*
282	 * OCTL.PeriMode = 1
283	 * OCTL.TermSelDLPulse = 0/1, OCTL.HNPReq = 0
284	 * OCTL.DevSetHNPEn = 0, OCTL.HstSetHNPEn = 0
285	 */
286	reg = dwc3_readl(dwc->regs, DWC3_OCTL);
287	reg |= DWC3_OCTL_PERIMODE;
288	reg &= ~(DWC3_OCTL_TERMSELIDPULSE | DWC3_OCTL_HNPREQ |
289			DWC3_OCTL_DEVSETHNPEN | DWC3_OCTL_HSTSETHNPEN);
290	dwc3_writel(dwc->regs, DWC3_OCTL, reg);
291	/* OEVTEN.OTGBDevSesVldDetEvntEn = 1 */
292	dwc3_otg_enable_events(dwc, DWC3_OEVTEN_BDEVSESSVLDDETEN);
293	/* GUSB2PHYCFG.ULPIAutoRes = 0, GUSB2PHYCFG0.SusPHY = 1 */
294	if (!dwc->dis_u2_susphy_quirk) {
295		reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
296		reg |= DWC3_GUSB2PHYCFG_SUSPHY;
297		dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
298	}
299	/* GCTL.GblHibernationEn = 0. Already 0. */
300}
301
302/* should be called after the gadget controller driver is stopped */
303static void dwc3_otg_device_exit(struct dwc3 *dwc)
304{
305	u32 reg;
306
307	/*
308	 * Exit from B-device flow as per
309	 * Figure 11-4 OTG Driver Overall Programming Flow
310	 */
311
312	/*
313	 * OEVTEN.OTGBDevHNPChngEvntEn = 0
314	 * OEVTEN.OTGBDevVBusChngEvntEn = 0
315	 * OEVTEN.OTGBDevBHostEndEvntEn = 0
316	 */
317	dwc3_otg_disable_events(dwc, DWC3_OEVTEN_BDEVHNPCHNGEN |
318				DWC3_OEVTEN_BDEVVBUSCHNGEN |
319				DWC3_OEVTEN_BDEVBHOSTENDEN);
320
321	/* OCTL.DevSetHNPEn = 0, OCTL.HNPReq = 0, OCTL.PeriMode=1 */
322	reg = dwc3_readl(dwc->regs, DWC3_OCTL);
323	reg &= ~(DWC3_OCTL_DEVSETHNPEN | DWC3_OCTL_HNPREQ);
324	reg |= DWC3_OCTL_PERIMODE;
325	dwc3_writel(dwc->regs, DWC3_OCTL, reg);
326}
327
328void dwc3_otg_update(struct dwc3 *dwc, bool ignore_idstatus)
329{
330	int ret;
331	u32 reg;
332	int id;
333	unsigned long flags;
334
335	if (dwc->dr_mode != USB_DR_MODE_OTG)
336		return;
337
338	/* don't do anything if debug user changed role to not OTG */
339	if (dwc->current_dr_role != DWC3_GCTL_PRTCAP_OTG)
340		return;
341
342	if (!ignore_idstatus) {
343		reg = dwc3_readl(dwc->regs, DWC3_OSTS);
344		id = !!(reg & DWC3_OSTS_CONIDSTS);
345
346		dwc->desired_otg_role = id ? DWC3_OTG_ROLE_DEVICE :
347					DWC3_OTG_ROLE_HOST;
348	}
349
350	if (dwc->desired_otg_role == dwc->current_otg_role)
351		return;
352
353	switch (dwc->current_otg_role) {
354	case DWC3_OTG_ROLE_HOST:
355		dwc3_host_exit(dwc);
356		spin_lock_irqsave(&dwc->lock, flags);
357		dwc3_otg_host_exit(dwc);
358		spin_unlock_irqrestore(&dwc->lock, flags);
359		break;
360	case DWC3_OTG_ROLE_DEVICE:
361		dwc3_gadget_exit(dwc);
362		spin_lock_irqsave(&dwc->lock, flags);
363		dwc3_event_buffers_cleanup(dwc);
364		dwc3_otg_device_exit(dwc);
365		spin_unlock_irqrestore(&dwc->lock, flags);
366		break;
367	default:
368		break;
369	}
370
371	spin_lock_irqsave(&dwc->lock, flags);
372
373	dwc->current_otg_role = dwc->desired_otg_role;
374
375	spin_unlock_irqrestore(&dwc->lock, flags);
376
377	switch (dwc->desired_otg_role) {
378	case DWC3_OTG_ROLE_HOST:
379		spin_lock_irqsave(&dwc->lock, flags);
380		dwc3_otgregs_init(dwc);
381		dwc3_otg_host_init(dwc);
382		spin_unlock_irqrestore(&dwc->lock, flags);
383		ret = dwc3_host_init(dwc);
384		if (ret) {
385			dev_err(dwc->dev, "failed to initialize host\n");
386		} else {
387			if (dwc->usb2_phy)
388				otg_set_vbus(dwc->usb2_phy->otg, true);
389			if (dwc->usb2_generic_phy)
390				phy_set_mode(dwc->usb2_generic_phy,
391					     PHY_MODE_USB_HOST);
392		}
393		break;
394	case DWC3_OTG_ROLE_DEVICE:
395		spin_lock_irqsave(&dwc->lock, flags);
396		dwc3_otgregs_init(dwc);
397		dwc3_otg_device_init(dwc);
398		dwc3_event_buffers_setup(dwc);
399		spin_unlock_irqrestore(&dwc->lock, flags);
400
401		if (dwc->usb2_phy)
402			otg_set_vbus(dwc->usb2_phy->otg, false);
403		if (dwc->usb2_generic_phy)
404			phy_set_mode(dwc->usb2_generic_phy,
405				     PHY_MODE_USB_DEVICE);
406		ret = dwc3_gadget_init(dwc);
407		if (ret)
408			dev_err(dwc->dev, "failed to initialize peripheral\n");
409		break;
410	default:
411		break;
412	}
413}
414
415static void dwc3_drd_update(struct dwc3 *dwc)
416{
417	int id;
418
419	if (dwc->edev) {
420		id = extcon_get_state(dwc->edev, EXTCON_USB_HOST);
421		if (id < 0)
422			id = 0;
423		dwc3_set_mode(dwc, id ?
424			      DWC3_GCTL_PRTCAP_HOST :
425			      DWC3_GCTL_PRTCAP_DEVICE);
426	}
427}
428
429static int dwc3_drd_notifier(struct notifier_block *nb,
430			     unsigned long event, void *ptr)
431{
432	struct dwc3 *dwc = container_of(nb, struct dwc3, edev_nb);
433
434	dwc3_set_mode(dwc, event ?
435		      DWC3_GCTL_PRTCAP_HOST :
436		      DWC3_GCTL_PRTCAP_DEVICE);
437
438	return NOTIFY_DONE;
439}
440
441static struct extcon_dev *dwc3_get_extcon(struct dwc3 *dwc)
442{
443	struct device *dev = dwc->dev;
444	struct device_node *np_phy, *np_conn;
445	struct extcon_dev *edev;
446	const char *name;
447
448	if (device_property_read_bool(dev, "extcon"))
449		return extcon_get_edev_by_phandle(dev, 0);
450
451	/*
452	 * Device tree platforms should get extcon via phandle.
453	 * On ACPI platforms, we get the name from a device property.
454	 * This device property is for kernel internal use only and
455	 * is expected to be set by the glue code.
456	 */
457	if (device_property_read_string(dev, "linux,extcon-name", &name) == 0) {
458		edev = extcon_get_extcon_dev(name);
459		if (!edev)
460			return ERR_PTR(-EPROBE_DEFER);
461
462		return edev;
463	}
464
465	np_phy = of_parse_phandle(dev->of_node, "phys", 0);
466	np_conn = of_graph_get_remote_node(np_phy, -1, -1);
467
468	if (np_conn)
469		edev = extcon_find_edev_by_node(np_conn);
470	else
471		edev = NULL;
472
473	of_node_put(np_conn);
474	of_node_put(np_phy);
475
476	return edev;
477}
478
479#if IS_ENABLED(CONFIG_USB_ROLE_SWITCH)
480#define ROLE_SWITCH 1
481static int dwc3_usb_role_switch_set(struct usb_role_switch *sw,
482				    enum usb_role role)
483{
484	struct dwc3 *dwc = usb_role_switch_get_drvdata(sw);
485	u32 mode;
486
487	switch (role) {
488	case USB_ROLE_HOST:
489		mode = DWC3_GCTL_PRTCAP_HOST;
490		break;
491	case USB_ROLE_DEVICE:
492		mode = DWC3_GCTL_PRTCAP_DEVICE;
493		break;
494	default:
495		if (dwc->role_switch_default_mode == USB_DR_MODE_HOST)
496			mode = DWC3_GCTL_PRTCAP_HOST;
497		else
498			mode = DWC3_GCTL_PRTCAP_DEVICE;
499		break;
500	}
501
502	dwc3_set_mode(dwc, mode);
503	return 0;
504}
505
506static enum usb_role dwc3_usb_role_switch_get(struct usb_role_switch *sw)
507{
508	struct dwc3 *dwc = usb_role_switch_get_drvdata(sw);
509	unsigned long flags;
510	enum usb_role role;
511
512	spin_lock_irqsave(&dwc->lock, flags);
513	switch (dwc->current_dr_role) {
514	case DWC3_GCTL_PRTCAP_HOST:
515		role = USB_ROLE_HOST;
516		break;
517	case DWC3_GCTL_PRTCAP_DEVICE:
518		role = USB_ROLE_DEVICE;
519		break;
520	case DWC3_GCTL_PRTCAP_OTG:
521		role = dwc->current_otg_role;
522		break;
523	default:
524		if (dwc->role_switch_default_mode == USB_DR_MODE_HOST)
525			role = USB_ROLE_HOST;
526		else
527			role = USB_ROLE_DEVICE;
528		break;
529	}
530	spin_unlock_irqrestore(&dwc->lock, flags);
531	return role;
532}
533
534static int dwc3_setup_role_switch(struct dwc3 *dwc)
535{
536	struct usb_role_switch_desc dwc3_role_switch = {NULL};
537	const char *str;
538	u32 mode;
539	int ret;
540
541	ret = device_property_read_string(dwc->dev, "role-switch-default-mode",
542					  &str);
543	if (ret >= 0  && !strncmp(str, "host", strlen("host"))) {
544		dwc->role_switch_default_mode = USB_DR_MODE_HOST;
545		mode = DWC3_GCTL_PRTCAP_HOST;
546	} else {
547		dwc->role_switch_default_mode = USB_DR_MODE_PERIPHERAL;
548		mode = DWC3_GCTL_PRTCAP_DEVICE;
549	}
550	dwc3_set_mode(dwc, mode);
551
552	dwc3_role_switch.fwnode = dev_fwnode(dwc->dev);
553	dwc3_role_switch.set = dwc3_usb_role_switch_set;
554	dwc3_role_switch.get = dwc3_usb_role_switch_get;
555	dwc3_role_switch.driver_data = dwc;
556	dwc->role_sw = usb_role_switch_register(dwc->dev, &dwc3_role_switch);
557	if (IS_ERR(dwc->role_sw))
558		return PTR_ERR(dwc->role_sw);
559
560	return 0;
561}
562#else
563#define ROLE_SWITCH 0
564#define dwc3_setup_role_switch(x) 0
565#endif
566
567int dwc3_drd_init(struct dwc3 *dwc)
568{
569	int ret, irq;
570
571	if (ROLE_SWITCH &&
572	    device_property_read_bool(dwc->dev, "usb-role-switch"))
573		return dwc3_setup_role_switch(dwc);
574
575	dwc->edev = dwc3_get_extcon(dwc);
576	if (IS_ERR(dwc->edev))
577		return PTR_ERR(dwc->edev);
578
579	if (dwc->edev) {
580		dwc->edev_nb.notifier_call = dwc3_drd_notifier;
581		ret = extcon_register_notifier(dwc->edev, EXTCON_USB_HOST,
582					       &dwc->edev_nb);
583		if (ret < 0) {
584			dev_err(dwc->dev, "couldn't register cable notifier\n");
585			return ret;
586		}
587
588		dwc3_drd_update(dwc);
589	} else {
590		dwc3_set_prtcap(dwc, DWC3_GCTL_PRTCAP_OTG);
591		dwc->current_dr_role = DWC3_GCTL_PRTCAP_OTG;
592
593		/* use OTG block to get ID event */
594		irq = dwc3_otg_get_irq(dwc);
595		if (irq < 0)
596			return irq;
597
598		dwc->otg_irq = irq;
599
600		/* disable all OTG IRQs */
601		dwc3_otg_disable_events(dwc, DWC3_OTG_ALL_EVENTS);
602		/* clear all events */
603		dwc3_otg_clear_events(dwc);
604
605		ret = request_threaded_irq(dwc->otg_irq, dwc3_otg_irq,
606					   dwc3_otg_thread_irq,
607					   IRQF_SHARED, "dwc3-otg", dwc);
608		if (ret) {
609			dev_err(dwc->dev, "failed to request irq #%d --> %d\n",
610				dwc->otg_irq, ret);
611			ret = -ENODEV;
612			return ret;
613		}
614
615		dwc3_otg_init(dwc);
616		dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_OTG);
617	}
618
619	return 0;
620}
621
622void dwc3_drd_exit(struct dwc3 *dwc)
623{
624	unsigned long flags;
625
626	if (dwc->role_sw)
627		usb_role_switch_unregister(dwc->role_sw);
628
629	if (dwc->edev)
630		extcon_unregister_notifier(dwc->edev, EXTCON_USB_HOST,
631					   &dwc->edev_nb);
632
633	cancel_work_sync(&dwc->drd_work);
634
635	/* debug user might have changed role, clean based on current role */
636	switch (dwc->current_dr_role) {
637	case DWC3_GCTL_PRTCAP_HOST:
638		dwc3_host_exit(dwc);
639		break;
640	case DWC3_GCTL_PRTCAP_DEVICE:
641		dwc3_gadget_exit(dwc);
642		dwc3_event_buffers_cleanup(dwc);
643		break;
644	case DWC3_GCTL_PRTCAP_OTG:
645		dwc3_otg_exit(dwc);
646		spin_lock_irqsave(&dwc->lock, flags);
647		dwc->desired_otg_role = DWC3_OTG_ROLE_IDLE;
648		spin_unlock_irqrestore(&dwc->lock, flags);
649		dwc3_otg_update(dwc, 1);
650		break;
651	default:
652		break;
653	}
654
655	if (dwc->otg_irq)
656		free_irq(dwc->otg_irq, dwc);
657}
658