xref: /linux/drivers/usb/dwc3/drd.c (revision c358f53871605a1a8d7ed6e544a05ea00e9c80cb)
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/of_platform.h>
13 #include <linux/platform_device.h>
14 #include <linux/property.h>
15 
16 #include "debug.h"
17 #include "core.h"
18 #include "gadget.h"
19 
20 static void dwc3_otg_disable_events(struct dwc3 *dwc, u32 disable_mask)
21 {
22 	u32 reg = dwc3_readl(dwc->regs, DWC3_OEVTEN);
23 
24 	reg &= ~(disable_mask);
25 	dwc3_writel(dwc->regs, DWC3_OEVTEN, reg);
26 }
27 
28 static void dwc3_otg_enable_events(struct dwc3 *dwc, u32 enable_mask)
29 {
30 	u32 reg = dwc3_readl(dwc->regs, DWC3_OEVTEN);
31 
32 	reg |= (enable_mask);
33 	dwc3_writel(dwc->regs, DWC3_OEVTEN, reg);
34 }
35 
36 static void dwc3_otg_clear_events(struct dwc3 *dwc)
37 {
38 	u32 reg = dwc3_readl(dwc->regs, DWC3_OEVT);
39 
40 	dwc3_writel(dwc->regs, DWC3_OEVTEN, reg);
41 }
42 
43 #define DWC3_OTG_ALL_EVENTS	(DWC3_OEVTEN_XHCIRUNSTPSETEN | \
44 		DWC3_OEVTEN_DEVRUNSTPSETEN | DWC3_OEVTEN_HIBENTRYEN | \
45 		DWC3_OEVTEN_CONIDSTSCHNGEN | DWC3_OEVTEN_HRRCONFNOTIFEN | \
46 		DWC3_OEVTEN_HRRINITNOTIFEN | DWC3_OEVTEN_ADEVIDLEEN | \
47 		DWC3_OEVTEN_ADEVBHOSTENDEN | DWC3_OEVTEN_ADEVHOSTEN | \
48 		DWC3_OEVTEN_ADEVHNPCHNGEN | DWC3_OEVTEN_ADEVSRPDETEN | \
49 		DWC3_OEVTEN_ADEVSESSENDDETEN | DWC3_OEVTEN_BDEVBHOSTENDEN | \
50 		DWC3_OEVTEN_BDEVHNPCHNGEN | DWC3_OEVTEN_BDEVSESSVLDDETEN | \
51 		DWC3_OEVTEN_BDEVVBUSCHNGEN)
52 
53 static irqreturn_t dwc3_otg_thread_irq(int irq, void *_dwc)
54 {
55 	struct dwc3 *dwc = _dwc;
56 
57 	spin_lock(&dwc->lock);
58 	if (dwc->otg_restart_host) {
59 		dwc3_otg_host_init(dwc);
60 		dwc->otg_restart_host = false;
61 	}
62 
63 	spin_unlock(&dwc->lock);
64 
65 	dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_OTG);
66 
67 	return IRQ_HANDLED;
68 }
69 
70 static irqreturn_t dwc3_otg_irq(int irq, void *_dwc)
71 {
72 	u32 reg;
73 	struct dwc3 *dwc = _dwc;
74 	irqreturn_t ret = IRQ_NONE;
75 
76 	reg = dwc3_readl(dwc->regs, DWC3_OEVT);
77 	if (reg) {
78 		/* ignore non OTG events, we can't disable them in OEVTEN */
79 		if (!(reg & DWC3_OTG_ALL_EVENTS)) {
80 			dwc3_writel(dwc->regs, DWC3_OEVT, reg);
81 			return IRQ_NONE;
82 		}
83 
84 		if (dwc->current_otg_role == DWC3_OTG_ROLE_HOST &&
85 		    !(reg & DWC3_OEVT_DEVICEMODE))
86 			dwc->otg_restart_host = true;
87 		dwc3_writel(dwc->regs, DWC3_OEVT, reg);
88 		ret = IRQ_WAKE_THREAD;
89 	}
90 
91 	return ret;
92 }
93 
94 static void dwc3_otgregs_init(struct dwc3 *dwc)
95 {
96 	u32 reg;
97 
98 	/*
99 	 * Prevent host/device reset from resetting OTG core.
100 	 * If we don't do this then xhci_reset (USBCMD.HCRST) will reset
101 	 * the signal outputs sent to the PHY, the OTG FSM logic of the
102 	 * core and also the resets to the VBUS filters inside the core.
103 	 */
104 	reg = dwc3_readl(dwc->regs, DWC3_OCFG);
105 	reg |= DWC3_OCFG_SFTRSTMASK;
106 	dwc3_writel(dwc->regs, DWC3_OCFG, reg);
107 
108 	/* Disable hibernation for simplicity */
109 	reg = dwc3_readl(dwc->regs, DWC3_GCTL);
110 	reg &= ~DWC3_GCTL_GBLHIBERNATIONEN;
111 	dwc3_writel(dwc->regs, DWC3_GCTL, reg);
112 
113 	/*
114 	 * Initialize OTG registers as per
115 	 * Figure 11-4 OTG Driver Overall Programming Flow
116 	 */
117 	/* OCFG.SRPCap = 0, OCFG.HNPCap = 0 */
118 	reg = dwc3_readl(dwc->regs, DWC3_OCFG);
119 	reg &= ~(DWC3_OCFG_SRPCAP | DWC3_OCFG_HNPCAP);
120 	dwc3_writel(dwc->regs, DWC3_OCFG, reg);
121 	/* OEVT = FFFF */
122 	dwc3_otg_clear_events(dwc);
123 	/* OEVTEN = 0 */
124 	dwc3_otg_disable_events(dwc, DWC3_OTG_ALL_EVENTS);
125 	/* OEVTEN.ConIDStsChngEn = 1. Instead we enable all events */
126 	dwc3_otg_enable_events(dwc, DWC3_OTG_ALL_EVENTS);
127 	/*
128 	 * OCTL.PeriMode = 1, OCTL.DevSetHNPEn = 0, OCTL.HstSetHNPEn = 0,
129 	 * OCTL.HNPReq = 0
130 	 */
131 	reg = dwc3_readl(dwc->regs, DWC3_OCTL);
132 	reg |= DWC3_OCTL_PERIMODE;
133 	reg &= ~(DWC3_OCTL_DEVSETHNPEN | DWC3_OCTL_HSTSETHNPEN |
134 		 DWC3_OCTL_HNPREQ);
135 	dwc3_writel(dwc->regs, DWC3_OCTL, reg);
136 }
137 
138 static int dwc3_otg_get_irq(struct dwc3 *dwc)
139 {
140 	struct platform_device *dwc3_pdev = to_platform_device(dwc->dev);
141 	int irq;
142 
143 	irq = platform_get_irq_byname_optional(dwc3_pdev, "otg");
144 	if (irq > 0)
145 		goto out;
146 
147 	if (irq == -EPROBE_DEFER)
148 		goto out;
149 
150 	irq = platform_get_irq_byname_optional(dwc3_pdev, "dwc_usb3");
151 	if (irq > 0)
152 		goto out;
153 
154 	if (irq == -EPROBE_DEFER)
155 		goto out;
156 
157 	irq = platform_get_irq(dwc3_pdev, 0);
158 	if (irq > 0)
159 		goto out;
160 
161 	if (!irq)
162 		irq = -EINVAL;
163 
164 out:
165 	return irq;
166 }
167 
168 void dwc3_otg_init(struct dwc3 *dwc)
169 {
170 	u32 reg;
171 
172 	/*
173 	 * As per Figure 11-4 OTG Driver Overall Programming Flow,
174 	 * block "Initialize GCTL for OTG operation".
175 	 */
176 	/* GCTL.PrtCapDir=2'b11 */
177 	dwc3_set_prtcap(dwc, DWC3_GCTL_PRTCAP_OTG);
178 	/* GUSB2PHYCFG0.SusPHY=0 */
179 	reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
180 	reg &= ~DWC3_GUSB2PHYCFG_SUSPHY;
181 	dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
182 
183 	/* Initialize OTG registers */
184 	dwc3_otgregs_init(dwc);
185 }
186 
187 void dwc3_otg_exit(struct dwc3 *dwc)
188 {
189 	/* disable all OTG IRQs */
190 	dwc3_otg_disable_events(dwc, DWC3_OTG_ALL_EVENTS);
191 	/* clear all events */
192 	dwc3_otg_clear_events(dwc);
193 }
194 
195 /* should be called before Host controller driver is started */
196 void dwc3_otg_host_init(struct dwc3 *dwc)
197 {
198 	u32 reg;
199 
200 	/* As per Figure 11-10 A-Device Flow Diagram */
201 	/* OCFG.HNPCap = 0, OCFG.SRPCap = 0. Already 0 */
202 
203 	/*
204 	 * OCTL.PeriMode=0, OCTL.TermSelDLPulse = 0,
205 	 * OCTL.DevSetHNPEn = 0, OCTL.HstSetHNPEn = 0
206 	 */
207 	reg = dwc3_readl(dwc->regs, DWC3_OCTL);
208 	reg &= ~(DWC3_OCTL_PERIMODE | DWC3_OCTL_TERMSELIDPULSE |
209 			DWC3_OCTL_DEVSETHNPEN | DWC3_OCTL_HSTSETHNPEN);
210 	dwc3_writel(dwc->regs, DWC3_OCTL, reg);
211 
212 	/*
213 	 * OCFG.DisPrtPwrCutoff = 0/1
214 	 */
215 	reg = dwc3_readl(dwc->regs, DWC3_OCFG);
216 	reg &= ~DWC3_OCFG_DISPWRCUTTOFF;
217 	dwc3_writel(dwc->regs, DWC3_OCFG, reg);
218 
219 	/*
220 	 * OCFG.SRPCap = 1, OCFG.HNPCap = GHWPARAMS6.HNP_CAP
221 	 * We don't want SRP/HNP for simple dual-role so leave
222 	 * these disabled.
223 	 */
224 
225 	/*
226 	 * OEVTEN.OTGADevHostEvntEn = 1
227 	 * OEVTEN.OTGADevSessEndDetEvntEn = 1
228 	 * We don't want HNP/role-swap so leave these disabled.
229 	 */
230 
231 	/* GUSB2PHYCFG.ULPIAutoRes = 1/0, GUSB2PHYCFG.SusPHY = 1 */
232 	if (!dwc->dis_u2_susphy_quirk) {
233 		reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
234 		reg |= DWC3_GUSB2PHYCFG_SUSPHY;
235 		dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
236 	}
237 
238 	/* Set Port Power to enable VBUS: OCTL.PrtPwrCtl = 1 */
239 	reg = dwc3_readl(dwc->regs, DWC3_OCTL);
240 	reg |= DWC3_OCTL_PRTPWRCTL;
241 	dwc3_writel(dwc->regs, DWC3_OCTL, reg);
242 }
243 
244 /* should be called after Host controller driver is stopped */
245 static void dwc3_otg_host_exit(struct dwc3 *dwc)
246 {
247 	u32 reg;
248 
249 	/*
250 	 * Exit from A-device flow as per
251 	 * Figure 11-4 OTG Driver Overall Programming Flow
252 	 */
253 
254 	/*
255 	 * OEVTEN.OTGADevBHostEndEvntEn=0, OEVTEN.OTGADevHNPChngEvntEn=0
256 	 * OEVTEN.OTGADevSessEndDetEvntEn=0,
257 	 * OEVTEN.OTGADevHostEvntEn = 0
258 	 * But we don't disable any OTG events
259 	 */
260 
261 	/* OCTL.HstSetHNPEn = 0, OCTL.PrtPwrCtl=0 */
262 	reg = dwc3_readl(dwc->regs, DWC3_OCTL);
263 	reg &= ~(DWC3_OCTL_HSTSETHNPEN | DWC3_OCTL_PRTPWRCTL);
264 	dwc3_writel(dwc->regs, DWC3_OCTL, reg);
265 }
266 
267 /* should be called before the gadget controller driver is started */
268 static void dwc3_otg_device_init(struct dwc3 *dwc)
269 {
270 	u32 reg;
271 
272 	/* As per Figure 11-20 B-Device Flow Diagram */
273 
274 	/*
275 	 * OCFG.HNPCap = GHWPARAMS6.HNP_CAP, OCFG.SRPCap = 1
276 	 * but we keep them 0 for simple dual-role operation.
277 	 */
278 	reg = dwc3_readl(dwc->regs, DWC3_OCFG);
279 	/* OCFG.OTGSftRstMsk = 0/1 */
280 	reg |= DWC3_OCFG_SFTRSTMASK;
281 	dwc3_writel(dwc->regs, DWC3_OCFG, reg);
282 	/*
283 	 * OCTL.PeriMode = 1
284 	 * OCTL.TermSelDLPulse = 0/1, OCTL.HNPReq = 0
285 	 * OCTL.DevSetHNPEn = 0, OCTL.HstSetHNPEn = 0
286 	 */
287 	reg = dwc3_readl(dwc->regs, DWC3_OCTL);
288 	reg |= DWC3_OCTL_PERIMODE;
289 	reg &= ~(DWC3_OCTL_TERMSELIDPULSE | DWC3_OCTL_HNPREQ |
290 			DWC3_OCTL_DEVSETHNPEN | DWC3_OCTL_HSTSETHNPEN);
291 	dwc3_writel(dwc->regs, DWC3_OCTL, reg);
292 	/* OEVTEN.OTGBDevSesVldDetEvntEn = 1 */
293 	dwc3_otg_enable_events(dwc, DWC3_OEVTEN_BDEVSESSVLDDETEN);
294 	/* GUSB2PHYCFG.ULPIAutoRes = 0, GUSB2PHYCFG0.SusPHY = 1 */
295 	if (!dwc->dis_u2_susphy_quirk) {
296 		reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
297 		reg |= DWC3_GUSB2PHYCFG_SUSPHY;
298 		dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
299 	}
300 	/* GCTL.GblHibernationEn = 0. Already 0. */
301 }
302 
303 /* should be called after the gadget controller driver is stopped */
304 static void dwc3_otg_device_exit(struct dwc3 *dwc)
305 {
306 	u32 reg;
307 
308 	/*
309 	 * Exit from B-device flow as per
310 	 * Figure 11-4 OTG Driver Overall Programming Flow
311 	 */
312 
313 	/*
314 	 * OEVTEN.OTGBDevHNPChngEvntEn = 0
315 	 * OEVTEN.OTGBDevVBusChngEvntEn = 0
316 	 * OEVTEN.OTGBDevBHostEndEvntEn = 0
317 	 */
318 	dwc3_otg_disable_events(dwc, DWC3_OEVTEN_BDEVHNPCHNGEN |
319 				DWC3_OEVTEN_BDEVVBUSCHNGEN |
320 				DWC3_OEVTEN_BDEVBHOSTENDEN);
321 
322 	/* OCTL.DevSetHNPEn = 0, OCTL.HNPReq = 0, OCTL.PeriMode=1 */
323 	reg = dwc3_readl(dwc->regs, DWC3_OCTL);
324 	reg &= ~(DWC3_OCTL_DEVSETHNPEN | DWC3_OCTL_HNPREQ);
325 	reg |= DWC3_OCTL_PERIMODE;
326 	dwc3_writel(dwc->regs, DWC3_OCTL, reg);
327 }
328 
329 void dwc3_otg_update(struct dwc3 *dwc, bool ignore_idstatus)
330 {
331 	int ret;
332 	u32 reg;
333 	int id;
334 	unsigned long flags;
335 
336 	if (dwc->dr_mode != USB_DR_MODE_OTG)
337 		return;
338 
339 	/* don't do anything if debug user changed role to not OTG */
340 	if (dwc->current_dr_role != DWC3_GCTL_PRTCAP_OTG)
341 		return;
342 
343 	if (!ignore_idstatus) {
344 		reg = dwc3_readl(dwc->regs, DWC3_OSTS);
345 		id = !!(reg & DWC3_OSTS_CONIDSTS);
346 
347 		dwc->desired_otg_role = id ? DWC3_OTG_ROLE_DEVICE :
348 					DWC3_OTG_ROLE_HOST;
349 	}
350 
351 	if (dwc->desired_otg_role == dwc->current_otg_role)
352 		return;
353 
354 	switch (dwc->current_otg_role) {
355 	case DWC3_OTG_ROLE_HOST:
356 		dwc3_host_exit(dwc);
357 		spin_lock_irqsave(&dwc->lock, flags);
358 		dwc3_otg_host_exit(dwc);
359 		spin_unlock_irqrestore(&dwc->lock, flags);
360 		break;
361 	case DWC3_OTG_ROLE_DEVICE:
362 		dwc3_gadget_exit(dwc);
363 		spin_lock_irqsave(&dwc->lock, flags);
364 		dwc3_event_buffers_cleanup(dwc);
365 		dwc3_otg_device_exit(dwc);
366 		spin_unlock_irqrestore(&dwc->lock, flags);
367 		break;
368 	default:
369 		break;
370 	}
371 
372 	spin_lock_irqsave(&dwc->lock, flags);
373 
374 	dwc->current_otg_role = dwc->desired_otg_role;
375 
376 	spin_unlock_irqrestore(&dwc->lock, flags);
377 
378 	switch (dwc->desired_otg_role) {
379 	case DWC3_OTG_ROLE_HOST:
380 		spin_lock_irqsave(&dwc->lock, flags);
381 		dwc3_otgregs_init(dwc);
382 		dwc3_otg_host_init(dwc);
383 		spin_unlock_irqrestore(&dwc->lock, flags);
384 		ret = dwc3_host_init(dwc);
385 		if (ret) {
386 			dev_err(dwc->dev, "failed to initialize host\n");
387 		} else {
388 			if (dwc->usb2_phy)
389 				otg_set_vbus(dwc->usb2_phy->otg, true);
390 			if (dwc->usb2_generic_phy)
391 				phy_set_mode(dwc->usb2_generic_phy,
392 					     PHY_MODE_USB_HOST);
393 		}
394 		break;
395 	case DWC3_OTG_ROLE_DEVICE:
396 		spin_lock_irqsave(&dwc->lock, flags);
397 		dwc3_otgregs_init(dwc);
398 		dwc3_otg_device_init(dwc);
399 		dwc3_event_buffers_setup(dwc);
400 		spin_unlock_irqrestore(&dwc->lock, flags);
401 
402 		if (dwc->usb2_phy)
403 			otg_set_vbus(dwc->usb2_phy->otg, false);
404 		if (dwc->usb2_generic_phy)
405 			phy_set_mode(dwc->usb2_generic_phy,
406 				     PHY_MODE_USB_DEVICE);
407 		ret = dwc3_gadget_init(dwc);
408 		if (ret)
409 			dev_err(dwc->dev, "failed to initialize peripheral\n");
410 		break;
411 	default:
412 		break;
413 	}
414 }
415 
416 static void dwc3_drd_update(struct dwc3 *dwc)
417 {
418 	int id;
419 
420 	if (dwc->edev) {
421 		id = extcon_get_state(dwc->edev, EXTCON_USB_HOST);
422 		if (id < 0)
423 			id = 0;
424 		dwc3_set_mode(dwc, id ?
425 			      DWC3_GCTL_PRTCAP_HOST :
426 			      DWC3_GCTL_PRTCAP_DEVICE);
427 	}
428 }
429 
430 static int dwc3_drd_notifier(struct notifier_block *nb,
431 			     unsigned long event, void *ptr)
432 {
433 	struct dwc3 *dwc = container_of(nb, struct dwc3, edev_nb);
434 
435 	dwc3_set_mode(dwc, event ?
436 		      DWC3_GCTL_PRTCAP_HOST :
437 		      DWC3_GCTL_PRTCAP_DEVICE);
438 
439 	return NOTIFY_DONE;
440 }
441 
442 static struct extcon_dev *dwc3_get_extcon(struct dwc3 *dwc)
443 {
444 	struct device *dev = dwc->dev;
445 	struct device_node *np_phy;
446 	struct extcon_dev *edev = NULL;
447 	const char *name;
448 
449 	if (device_property_read_bool(dev, "extcon"))
450 		return extcon_get_edev_by_phandle(dev, 0);
451 
452 	/*
453 	 * Device tree platforms should get extcon via phandle.
454 	 * On ACPI platforms, we get the name from a device property.
455 	 * This device property is for kernel internal use only and
456 	 * is expected to be set by the glue code.
457 	 */
458 	if (device_property_read_string(dev, "linux,extcon-name", &name) == 0) {
459 		edev = extcon_get_extcon_dev(name);
460 		if (!edev)
461 			return ERR_PTR(-EPROBE_DEFER);
462 
463 		return edev;
464 	}
465 
466 	/*
467 	 * Try to get an extcon device from the USB PHY controller's "port"
468 	 * node. Check if it has the "port" node first, to avoid printing the
469 	 * error message from underlying code, as it's a valid case: extcon
470 	 * device (and "port" node) may be missing in case of "usb-role-switch"
471 	 * or OTG mode.
472 	 */
473 	np_phy = of_parse_phandle(dev->of_node, "phys", 0);
474 	if (of_graph_is_present(np_phy)) {
475 		struct device_node *np_conn;
476 
477 		np_conn = of_graph_get_remote_node(np_phy, -1, -1);
478 		if (np_conn)
479 			edev = extcon_find_edev_by_node(np_conn);
480 		of_node_put(np_conn);
481 	}
482 	of_node_put(np_phy);
483 
484 	return edev;
485 }
486 
487 #if IS_ENABLED(CONFIG_USB_ROLE_SWITCH)
488 #define ROLE_SWITCH 1
489 static int dwc3_usb_role_switch_set(struct usb_role_switch *sw,
490 				    enum usb_role role)
491 {
492 	struct dwc3 *dwc = usb_role_switch_get_drvdata(sw);
493 	u32 mode;
494 
495 	switch (role) {
496 	case USB_ROLE_HOST:
497 		mode = DWC3_GCTL_PRTCAP_HOST;
498 		break;
499 	case USB_ROLE_DEVICE:
500 		mode = DWC3_GCTL_PRTCAP_DEVICE;
501 		break;
502 	default:
503 		if (dwc->role_switch_default_mode == USB_DR_MODE_HOST)
504 			mode = DWC3_GCTL_PRTCAP_HOST;
505 		else
506 			mode = DWC3_GCTL_PRTCAP_DEVICE;
507 		break;
508 	}
509 
510 	dwc3_set_mode(dwc, mode);
511 	return 0;
512 }
513 
514 static enum usb_role dwc3_usb_role_switch_get(struct usb_role_switch *sw)
515 {
516 	struct dwc3 *dwc = usb_role_switch_get_drvdata(sw);
517 	unsigned long flags;
518 	enum usb_role role;
519 
520 	spin_lock_irqsave(&dwc->lock, flags);
521 	switch (dwc->current_dr_role) {
522 	case DWC3_GCTL_PRTCAP_HOST:
523 		role = USB_ROLE_HOST;
524 		break;
525 	case DWC3_GCTL_PRTCAP_DEVICE:
526 		role = USB_ROLE_DEVICE;
527 		break;
528 	case DWC3_GCTL_PRTCAP_OTG:
529 		role = dwc->current_otg_role;
530 		break;
531 	default:
532 		if (dwc->role_switch_default_mode == USB_DR_MODE_HOST)
533 			role = USB_ROLE_HOST;
534 		else
535 			role = USB_ROLE_DEVICE;
536 		break;
537 	}
538 	spin_unlock_irqrestore(&dwc->lock, flags);
539 	return role;
540 }
541 
542 static int dwc3_setup_role_switch(struct dwc3 *dwc)
543 {
544 	struct usb_role_switch_desc dwc3_role_switch = {NULL};
545 	u32 mode;
546 
547 	dwc->role_switch_default_mode = usb_get_role_switch_default_mode(dwc->dev);
548 	if (dwc->role_switch_default_mode == USB_DR_MODE_HOST) {
549 		mode = DWC3_GCTL_PRTCAP_HOST;
550 	} else {
551 		dwc->role_switch_default_mode = USB_DR_MODE_PERIPHERAL;
552 		mode = DWC3_GCTL_PRTCAP_DEVICE;
553 	}
554 
555 	dwc3_role_switch.fwnode = dev_fwnode(dwc->dev);
556 	dwc3_role_switch.set = dwc3_usb_role_switch_set;
557 	dwc3_role_switch.get = dwc3_usb_role_switch_get;
558 	dwc3_role_switch.driver_data = dwc;
559 	dwc->role_sw = usb_role_switch_register(dwc->dev, &dwc3_role_switch);
560 	if (IS_ERR(dwc->role_sw))
561 		return PTR_ERR(dwc->role_sw);
562 
563 	if (dwc->dev->of_node) {
564 		/* populate connector entry */
565 		int ret = devm_of_platform_populate(dwc->dev);
566 
567 		if (ret) {
568 			usb_role_switch_unregister(dwc->role_sw);
569 			dwc->role_sw = NULL;
570 			dev_err(dwc->dev, "DWC3 platform devices creation failed: %i\n", ret);
571 			return ret;
572 		}
573 	}
574 
575 	dwc3_set_mode(dwc, mode);
576 	return 0;
577 }
578 #else
579 #define ROLE_SWITCH 0
580 #define dwc3_setup_role_switch(x) 0
581 #endif
582 
583 int dwc3_drd_init(struct dwc3 *dwc)
584 {
585 	int ret, irq;
586 
587 	if (ROLE_SWITCH &&
588 	    device_property_read_bool(dwc->dev, "usb-role-switch"))
589 		return dwc3_setup_role_switch(dwc);
590 
591 	dwc->edev = dwc3_get_extcon(dwc);
592 	if (IS_ERR(dwc->edev))
593 		return PTR_ERR(dwc->edev);
594 
595 	if (dwc->edev) {
596 		dwc->edev_nb.notifier_call = dwc3_drd_notifier;
597 		ret = extcon_register_notifier(dwc->edev, EXTCON_USB_HOST,
598 					       &dwc->edev_nb);
599 		if (ret < 0) {
600 			dev_err(dwc->dev, "couldn't register cable notifier\n");
601 			return ret;
602 		}
603 
604 		dwc3_drd_update(dwc);
605 	} else {
606 		dwc3_set_prtcap(dwc, DWC3_GCTL_PRTCAP_OTG);
607 
608 		/* use OTG block to get ID event */
609 		irq = dwc3_otg_get_irq(dwc);
610 		if (irq < 0)
611 			return irq;
612 
613 		dwc->otg_irq = irq;
614 
615 		/* disable all OTG IRQs */
616 		dwc3_otg_disable_events(dwc, DWC3_OTG_ALL_EVENTS);
617 		/* clear all events */
618 		dwc3_otg_clear_events(dwc);
619 
620 		ret = request_threaded_irq(dwc->otg_irq, dwc3_otg_irq,
621 					   dwc3_otg_thread_irq,
622 					   IRQF_SHARED, "dwc3-otg", dwc);
623 		if (ret) {
624 			dev_err(dwc->dev, "failed to request irq #%d --> %d\n",
625 				dwc->otg_irq, ret);
626 			ret = -ENODEV;
627 			return ret;
628 		}
629 
630 		dwc3_otg_init(dwc);
631 		dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_OTG);
632 	}
633 
634 	return 0;
635 }
636 
637 void dwc3_drd_exit(struct dwc3 *dwc)
638 {
639 	unsigned long flags;
640 
641 	if (dwc->role_sw)
642 		usb_role_switch_unregister(dwc->role_sw);
643 
644 	if (dwc->edev)
645 		extcon_unregister_notifier(dwc->edev, EXTCON_USB_HOST,
646 					   &dwc->edev_nb);
647 
648 	cancel_work_sync(&dwc->drd_work);
649 
650 	/* debug user might have changed role, clean based on current role */
651 	switch (dwc->current_dr_role) {
652 	case DWC3_GCTL_PRTCAP_HOST:
653 		dwc3_host_exit(dwc);
654 		break;
655 	case DWC3_GCTL_PRTCAP_DEVICE:
656 		dwc3_gadget_exit(dwc);
657 		dwc3_event_buffers_cleanup(dwc);
658 		break;
659 	case DWC3_GCTL_PRTCAP_OTG:
660 		dwc3_otg_exit(dwc);
661 		spin_lock_irqsave(&dwc->lock, flags);
662 		dwc->desired_otg_role = DWC3_OTG_ROLE_IDLE;
663 		spin_unlock_irqrestore(&dwc->lock, flags);
664 		dwc3_otg_update(dwc, 1);
665 		break;
666 	default:
667 		break;
668 	}
669 
670 	if (dwc->otg_irq)
671 		free_irq(dwc->otg_irq, dwc);
672 }
673