xref: /linux/drivers/usb/dwc3/drd.c (revision d195c39052d1da278a00a6744ce59c383b67b191)
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 - http://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 
19 static 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 
27 static 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 
35 static 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 
52 static 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 = 0;
60 	}
61 
62 	spin_unlock(&dwc->lock);
63 
64 	dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_OTG);
65 
66 	return IRQ_HANDLED;
67 }
68 
69 static 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 = 1;
86 		dwc3_writel(dwc->regs, DWC3_OEVT, reg);
87 		ret = IRQ_WAKE_THREAD;
88 	}
89 
90 	return ret;
91 }
92 
93 static 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 
137 static 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 
163 out:
164 	return irq;
165 }
166 
167 void 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 
186 void 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 */
195 void 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 */
244 static 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 */
267 static 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 */
303 static 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 
328 void 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 
415 static 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 
429 static 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 
441 static 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
481 static 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 
506 static 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 
534 static 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 
551 	dwc3_role_switch.fwnode = dev_fwnode(dwc->dev);
552 	dwc3_role_switch.set = dwc3_usb_role_switch_set;
553 	dwc3_role_switch.get = dwc3_usb_role_switch_get;
554 	dwc3_role_switch.driver_data = dwc;
555 	dwc->role_sw = usb_role_switch_register(dwc->dev, &dwc3_role_switch);
556 	if (IS_ERR(dwc->role_sw))
557 		return PTR_ERR(dwc->role_sw);
558 
559 	dwc3_set_mode(dwc, mode);
560 	return 0;
561 }
562 #else
563 #define ROLE_SWITCH 0
564 #define dwc3_setup_role_switch(x) 0
565 #endif
566 
567 int dwc3_drd_init(struct dwc3 *dwc)
568 {
569 	int ret, irq;
570 
571 	dwc->edev = dwc3_get_extcon(dwc);
572 	if (IS_ERR(dwc->edev))
573 		return PTR_ERR(dwc->edev);
574 
575 	if (ROLE_SWITCH &&
576 	    device_property_read_bool(dwc->dev, "usb-role-switch")) {
577 		ret = dwc3_setup_role_switch(dwc);
578 		if (ret < 0)
579 			return ret;
580 	} else if (dwc->edev) {
581 		dwc->edev_nb.notifier_call = dwc3_drd_notifier;
582 		ret = extcon_register_notifier(dwc->edev, EXTCON_USB_HOST,
583 					       &dwc->edev_nb);
584 		if (ret < 0) {
585 			dev_err(dwc->dev, "couldn't register cable notifier\n");
586 			return ret;
587 		}
588 
589 		dwc3_drd_update(dwc);
590 	} else {
591 		dwc3_set_prtcap(dwc, DWC3_GCTL_PRTCAP_OTG);
592 		dwc->current_dr_role = DWC3_GCTL_PRTCAP_OTG;
593 
594 		/* use OTG block to get ID event */
595 		irq = dwc3_otg_get_irq(dwc);
596 		if (irq < 0)
597 			return irq;
598 
599 		dwc->otg_irq = irq;
600 
601 		/* disable all OTG IRQs */
602 		dwc3_otg_disable_events(dwc, DWC3_OTG_ALL_EVENTS);
603 		/* clear all events */
604 		dwc3_otg_clear_events(dwc);
605 
606 		ret = request_threaded_irq(dwc->otg_irq, dwc3_otg_irq,
607 					   dwc3_otg_thread_irq,
608 					   IRQF_SHARED, "dwc3-otg", dwc);
609 		if (ret) {
610 			dev_err(dwc->dev, "failed to request irq #%d --> %d\n",
611 				dwc->otg_irq, ret);
612 			ret = -ENODEV;
613 			return ret;
614 		}
615 
616 		dwc3_otg_init(dwc);
617 		dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_OTG);
618 	}
619 
620 	return 0;
621 }
622 
623 void dwc3_drd_exit(struct dwc3 *dwc)
624 {
625 	unsigned long flags;
626 
627 	if (dwc->role_sw)
628 		usb_role_switch_unregister(dwc->role_sw);
629 
630 	if (dwc->edev)
631 		extcon_unregister_notifier(dwc->edev, EXTCON_USB_HOST,
632 					   &dwc->edev_nb);
633 
634 	cancel_work_sync(&dwc->drd_work);
635 
636 	/* debug user might have changed role, clean based on current role */
637 	switch (dwc->current_dr_role) {
638 	case DWC3_GCTL_PRTCAP_HOST:
639 		dwc3_host_exit(dwc);
640 		break;
641 	case DWC3_GCTL_PRTCAP_DEVICE:
642 		dwc3_gadget_exit(dwc);
643 		dwc3_event_buffers_cleanup(dwc);
644 		break;
645 	case DWC3_GCTL_PRTCAP_OTG:
646 		dwc3_otg_exit(dwc);
647 		spin_lock_irqsave(&dwc->lock, flags);
648 		dwc->desired_otg_role = DWC3_OTG_ROLE_IDLE;
649 		spin_unlock_irqrestore(&dwc->lock, flags);
650 		dwc3_otg_update(dwc, 1);
651 		break;
652 	default:
653 		break;
654 	}
655 
656 	if (!dwc->edev)
657 		free_irq(dwc->otg_irq, dwc);
658 }
659