xref: /openbmc/linux/drivers/usb/dwc3/drd.c (revision d2ba09c1)
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/platform_device.h>
12 
13 #include "debug.h"
14 #include "core.h"
15 #include "gadget.h"
16 
17 static void dwc3_otg_disable_events(struct dwc3 *dwc, u32 disable_mask)
18 {
19 	u32 reg = dwc3_readl(dwc->regs, DWC3_OEVTEN);
20 
21 	reg &= ~(disable_mask);
22 	dwc3_writel(dwc->regs, DWC3_OEVTEN, reg);
23 }
24 
25 static void dwc3_otg_enable_events(struct dwc3 *dwc, u32 enable_mask)
26 {
27 	u32 reg = dwc3_readl(dwc->regs, DWC3_OEVTEN);
28 
29 	reg |= (enable_mask);
30 	dwc3_writel(dwc->regs, DWC3_OEVTEN, reg);
31 }
32 
33 static void dwc3_otg_clear_events(struct dwc3 *dwc)
34 {
35 	u32 reg = dwc3_readl(dwc->regs, DWC3_OEVT);
36 
37 	dwc3_writel(dwc->regs, DWC3_OEVTEN, reg);
38 }
39 
40 #define DWC3_OTG_ALL_EVENTS	(DWC3_OEVTEN_XHCIRUNSTPSETEN | \
41 		DWC3_OEVTEN_DEVRUNSTPSETEN | DWC3_OEVTEN_HIBENTRYEN | \
42 		DWC3_OEVTEN_CONIDSTSCHNGEN | DWC3_OEVTEN_HRRCONFNOTIFEN | \
43 		DWC3_OEVTEN_HRRINITNOTIFEN | DWC3_OEVTEN_ADEVIDLEEN | \
44 		DWC3_OEVTEN_ADEVBHOSTENDEN | DWC3_OEVTEN_ADEVHOSTEN | \
45 		DWC3_OEVTEN_ADEVHNPCHNGEN | DWC3_OEVTEN_ADEVSRPDETEN | \
46 		DWC3_OEVTEN_ADEVSESSENDDETEN | DWC3_OEVTEN_BDEVBHOSTENDEN | \
47 		DWC3_OEVTEN_BDEVHNPCHNGEN | DWC3_OEVTEN_BDEVSESSVLDDETEN | \
48 		DWC3_OEVTEN_BDEVVBUSCHNGEN)
49 
50 static irqreturn_t dwc3_otg_thread_irq(int irq, void *_dwc)
51 {
52 	struct dwc3 *dwc = _dwc;
53 
54 	spin_lock(&dwc->lock);
55 	if (dwc->otg_restart_host) {
56 		dwc3_otg_host_init(dwc);
57 		dwc->otg_restart_host = 0;
58 	}
59 
60 	spin_unlock(&dwc->lock);
61 
62 	dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_OTG);
63 
64 	return IRQ_HANDLED;
65 }
66 
67 static irqreturn_t dwc3_otg_irq(int irq, void *_dwc)
68 {
69 	u32 reg;
70 	struct dwc3 *dwc = _dwc;
71 	irqreturn_t ret = IRQ_NONE;
72 
73 	reg = dwc3_readl(dwc->regs, DWC3_OEVT);
74 	if (reg) {
75 		/* ignore non OTG events, we can't disable them in OEVTEN */
76 		if (!(reg & DWC3_OTG_ALL_EVENTS)) {
77 			dwc3_writel(dwc->regs, DWC3_OEVT, reg);
78 			return IRQ_NONE;
79 		}
80 
81 		if (dwc->current_otg_role == DWC3_OTG_ROLE_HOST &&
82 		    !(reg & DWC3_OEVT_DEVICEMODE))
83 			dwc->otg_restart_host = 1;
84 		dwc3_writel(dwc->regs, DWC3_OEVT, reg);
85 		ret = IRQ_WAKE_THREAD;
86 	}
87 
88 	return ret;
89 }
90 
91 static void dwc3_otgregs_init(struct dwc3 *dwc)
92 {
93 	u32 reg;
94 
95 	/*
96 	 * Prevent host/device reset from resetting OTG core.
97 	 * If we don't do this then xhci_reset (USBCMD.HCRST) will reset
98 	 * the signal outputs sent to the PHY, the OTG FSM logic of the
99 	 * core and also the resets to the VBUS filters inside the core.
100 	 */
101 	reg = dwc3_readl(dwc->regs, DWC3_OCFG);
102 	reg |= DWC3_OCFG_SFTRSTMASK;
103 	dwc3_writel(dwc->regs, DWC3_OCFG, reg);
104 
105 	/* Disable hibernation for simplicity */
106 	reg = dwc3_readl(dwc->regs, DWC3_GCTL);
107 	reg &= ~DWC3_GCTL_GBLHIBERNATIONEN;
108 	dwc3_writel(dwc->regs, DWC3_GCTL, reg);
109 
110 	/*
111 	 * Initialize OTG registers as per
112 	 * Figure 11-4 OTG Driver Overall Programming Flow
113 	 */
114 	/* OCFG.SRPCap = 0, OCFG.HNPCap = 0 */
115 	reg = dwc3_readl(dwc->regs, DWC3_OCFG);
116 	reg &= ~(DWC3_OCFG_SRPCAP | DWC3_OCFG_HNPCAP);
117 	dwc3_writel(dwc->regs, DWC3_OCFG, reg);
118 	/* OEVT = FFFF */
119 	dwc3_otg_clear_events(dwc);
120 	/* OEVTEN = 0 */
121 	dwc3_otg_disable_events(dwc, DWC3_OTG_ALL_EVENTS);
122 	/* OEVTEN.ConIDStsChngEn = 1. Instead we enable all events */
123 	dwc3_otg_enable_events(dwc, DWC3_OTG_ALL_EVENTS);
124 	/*
125 	 * OCTL.PeriMode = 1, OCTL.DevSetHNPEn = 0, OCTL.HstSetHNPEn = 0,
126 	 * OCTL.HNPReq = 0
127 	 */
128 	reg = dwc3_readl(dwc->regs, DWC3_OCTL);
129 	reg |= DWC3_OCTL_PERIMODE;
130 	reg &= ~(DWC3_OCTL_DEVSETHNPEN | DWC3_OCTL_HSTSETHNPEN |
131 		 DWC3_OCTL_HNPREQ);
132 	dwc3_writel(dwc->regs, DWC3_OCTL, reg);
133 }
134 
135 static int dwc3_otg_get_irq(struct dwc3 *dwc)
136 {
137 	struct platform_device *dwc3_pdev = to_platform_device(dwc->dev);
138 	int irq;
139 
140 	irq = platform_get_irq_byname(dwc3_pdev, "otg");
141 	if (irq > 0)
142 		goto out;
143 
144 	if (irq == -EPROBE_DEFER)
145 		goto out;
146 
147 	irq = platform_get_irq_byname(dwc3_pdev, "dwc_usb3");
148 	if (irq > 0)
149 		goto out;
150 
151 	if (irq == -EPROBE_DEFER)
152 		goto out;
153 
154 	irq = platform_get_irq(dwc3_pdev, 0);
155 	if (irq > 0)
156 		goto out;
157 
158 	if (irq != -EPROBE_DEFER)
159 		dev_err(dwc->dev, "missing OTG IRQ\n");
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 int dwc3_drd_init(struct dwc3 *dwc)
443 {
444 	int ret, irq;
445 
446 	if (dwc->dev->of_node &&
447 	    of_property_read_bool(dwc->dev->of_node, "extcon")) {
448 		dwc->edev = extcon_get_edev_by_phandle(dwc->dev, 0);
449 
450 		if (IS_ERR(dwc->edev))
451 			return PTR_ERR(dwc->edev);
452 
453 		dwc->edev_nb.notifier_call = dwc3_drd_notifier;
454 		ret = extcon_register_notifier(dwc->edev, EXTCON_USB_HOST,
455 					       &dwc->edev_nb);
456 		if (ret < 0) {
457 			dev_err(dwc->dev, "couldn't register cable notifier\n");
458 			return ret;
459 		}
460 
461 		dwc3_drd_update(dwc);
462 	} else {
463 		dwc3_set_prtcap(dwc, DWC3_GCTL_PRTCAP_OTG);
464 		dwc->current_dr_role = DWC3_GCTL_PRTCAP_OTG;
465 
466 		/* use OTG block to get ID event */
467 		irq = dwc3_otg_get_irq(dwc);
468 		if (irq < 0)
469 			return irq;
470 
471 		dwc->otg_irq = irq;
472 
473 		/* disable all OTG IRQs */
474 		dwc3_otg_disable_events(dwc, DWC3_OTG_ALL_EVENTS);
475 		/* clear all events */
476 		dwc3_otg_clear_events(dwc);
477 
478 		ret = request_threaded_irq(dwc->otg_irq, dwc3_otg_irq,
479 					   dwc3_otg_thread_irq,
480 					   IRQF_SHARED, "dwc3-otg", dwc);
481 		if (ret) {
482 			dev_err(dwc->dev, "failed to request irq #%d --> %d\n",
483 				dwc->otg_irq, ret);
484 			ret = -ENODEV;
485 			return ret;
486 		}
487 
488 		dwc3_otg_init(dwc);
489 		dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_OTG);
490 	}
491 
492 	return 0;
493 }
494 
495 void dwc3_drd_exit(struct dwc3 *dwc)
496 {
497 	unsigned long flags;
498 
499 	if (dwc->edev)
500 		extcon_unregister_notifier(dwc->edev, EXTCON_USB_HOST,
501 					   &dwc->edev_nb);
502 
503 	cancel_work_sync(&dwc->drd_work);
504 
505 	/* debug user might have changed role, clean based on current role */
506 	switch (dwc->current_dr_role) {
507 	case DWC3_GCTL_PRTCAP_HOST:
508 		dwc3_host_exit(dwc);
509 		break;
510 	case DWC3_GCTL_PRTCAP_DEVICE:
511 		dwc3_gadget_exit(dwc);
512 		dwc3_event_buffers_cleanup(dwc);
513 		break;
514 	case DWC3_GCTL_PRTCAP_OTG:
515 		dwc3_otg_exit(dwc);
516 		spin_lock_irqsave(&dwc->lock, flags);
517 		dwc->desired_otg_role = DWC3_OTG_ROLE_IDLE;
518 		spin_unlock_irqrestore(&dwc->lock, flags);
519 		dwc3_otg_update(dwc, 1);
520 		break;
521 	default:
522 		break;
523 	}
524 
525 	if (!dwc->edev)
526 		free_irq(dwc->otg_irq, dwc);
527 }
528