xref: /openbmc/linux/drivers/usb/dwc3/drd.c (revision a17922de)
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 
14 #include "debug.h"
15 #include "core.h"
16 #include "gadget.h"
17 
18 static void dwc3_otg_disable_events(struct dwc3 *dwc, u32 disable_mask)
19 {
20 	u32 reg = dwc3_readl(dwc->regs, DWC3_OEVTEN);
21 
22 	reg &= ~(disable_mask);
23 	dwc3_writel(dwc->regs, DWC3_OEVTEN, reg);
24 }
25 
26 static void dwc3_otg_enable_events(struct dwc3 *dwc, u32 enable_mask)
27 {
28 	u32 reg = dwc3_readl(dwc->regs, DWC3_OEVTEN);
29 
30 	reg |= (enable_mask);
31 	dwc3_writel(dwc->regs, DWC3_OEVTEN, reg);
32 }
33 
34 static void dwc3_otg_clear_events(struct dwc3 *dwc)
35 {
36 	u32 reg = dwc3_readl(dwc->regs, DWC3_OEVT);
37 
38 	dwc3_writel(dwc->regs, DWC3_OEVTEN, reg);
39 }
40 
41 #define DWC3_OTG_ALL_EVENTS	(DWC3_OEVTEN_XHCIRUNSTPSETEN | \
42 		DWC3_OEVTEN_DEVRUNSTPSETEN | DWC3_OEVTEN_HIBENTRYEN | \
43 		DWC3_OEVTEN_CONIDSTSCHNGEN | DWC3_OEVTEN_HRRCONFNOTIFEN | \
44 		DWC3_OEVTEN_HRRINITNOTIFEN | DWC3_OEVTEN_ADEVIDLEEN | \
45 		DWC3_OEVTEN_ADEVBHOSTENDEN | DWC3_OEVTEN_ADEVHOSTEN | \
46 		DWC3_OEVTEN_ADEVHNPCHNGEN | DWC3_OEVTEN_ADEVSRPDETEN | \
47 		DWC3_OEVTEN_ADEVSESSENDDETEN | DWC3_OEVTEN_BDEVBHOSTENDEN | \
48 		DWC3_OEVTEN_BDEVHNPCHNGEN | DWC3_OEVTEN_BDEVSESSVLDDETEN | \
49 		DWC3_OEVTEN_BDEVVBUSCHNGEN)
50 
51 static irqreturn_t dwc3_otg_thread_irq(int irq, void *_dwc)
52 {
53 	struct dwc3 *dwc = _dwc;
54 
55 	spin_lock(&dwc->lock);
56 	if (dwc->otg_restart_host) {
57 		dwc3_otg_host_init(dwc);
58 		dwc->otg_restart_host = 0;
59 	}
60 
61 	spin_unlock(&dwc->lock);
62 
63 	dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_OTG);
64 
65 	return IRQ_HANDLED;
66 }
67 
68 static irqreturn_t dwc3_otg_irq(int irq, void *_dwc)
69 {
70 	u32 reg;
71 	struct dwc3 *dwc = _dwc;
72 	irqreturn_t ret = IRQ_NONE;
73 
74 	reg = dwc3_readl(dwc->regs, DWC3_OEVT);
75 	if (reg) {
76 		/* ignore non OTG events, we can't disable them in OEVTEN */
77 		if (!(reg & DWC3_OTG_ALL_EVENTS)) {
78 			dwc3_writel(dwc->regs, DWC3_OEVT, reg);
79 			return IRQ_NONE;
80 		}
81 
82 		if (dwc->current_otg_role == DWC3_OTG_ROLE_HOST &&
83 		    !(reg & DWC3_OEVT_DEVICEMODE))
84 			dwc->otg_restart_host = 1;
85 		dwc3_writel(dwc->regs, DWC3_OEVT, reg);
86 		ret = IRQ_WAKE_THREAD;
87 	}
88 
89 	return ret;
90 }
91 
92 static void dwc3_otgregs_init(struct dwc3 *dwc)
93 {
94 	u32 reg;
95 
96 	/*
97 	 * Prevent host/device reset from resetting OTG core.
98 	 * If we don't do this then xhci_reset (USBCMD.HCRST) will reset
99 	 * the signal outputs sent to the PHY, the OTG FSM logic of the
100 	 * core and also the resets to the VBUS filters inside the core.
101 	 */
102 	reg = dwc3_readl(dwc->regs, DWC3_OCFG);
103 	reg |= DWC3_OCFG_SFTRSTMASK;
104 	dwc3_writel(dwc->regs, DWC3_OCFG, reg);
105 
106 	/* Disable hibernation for simplicity */
107 	reg = dwc3_readl(dwc->regs, DWC3_GCTL);
108 	reg &= ~DWC3_GCTL_GBLHIBERNATIONEN;
109 	dwc3_writel(dwc->regs, DWC3_GCTL, reg);
110 
111 	/*
112 	 * Initialize OTG registers as per
113 	 * Figure 11-4 OTG Driver Overall Programming Flow
114 	 */
115 	/* OCFG.SRPCap = 0, OCFG.HNPCap = 0 */
116 	reg = dwc3_readl(dwc->regs, DWC3_OCFG);
117 	reg &= ~(DWC3_OCFG_SRPCAP | DWC3_OCFG_HNPCAP);
118 	dwc3_writel(dwc->regs, DWC3_OCFG, reg);
119 	/* OEVT = FFFF */
120 	dwc3_otg_clear_events(dwc);
121 	/* OEVTEN = 0 */
122 	dwc3_otg_disable_events(dwc, DWC3_OTG_ALL_EVENTS);
123 	/* OEVTEN.ConIDStsChngEn = 1. Instead we enable all events */
124 	dwc3_otg_enable_events(dwc, DWC3_OTG_ALL_EVENTS);
125 	/*
126 	 * OCTL.PeriMode = 1, OCTL.DevSetHNPEn = 0, OCTL.HstSetHNPEn = 0,
127 	 * OCTL.HNPReq = 0
128 	 */
129 	reg = dwc3_readl(dwc->regs, DWC3_OCTL);
130 	reg |= DWC3_OCTL_PERIMODE;
131 	reg &= ~(DWC3_OCTL_DEVSETHNPEN | DWC3_OCTL_HSTSETHNPEN |
132 		 DWC3_OCTL_HNPREQ);
133 	dwc3_writel(dwc->regs, DWC3_OCTL, reg);
134 }
135 
136 static int dwc3_otg_get_irq(struct dwc3 *dwc)
137 {
138 	struct platform_device *dwc3_pdev = to_platform_device(dwc->dev);
139 	int irq;
140 
141 	irq = platform_get_irq_byname(dwc3_pdev, "otg");
142 	if (irq > 0)
143 		goto out;
144 
145 	if (irq == -EPROBE_DEFER)
146 		goto out;
147 
148 	irq = platform_get_irq_byname(dwc3_pdev, "dwc_usb3");
149 	if (irq > 0)
150 		goto out;
151 
152 	if (irq == -EPROBE_DEFER)
153 		goto out;
154 
155 	irq = platform_get_irq(dwc3_pdev, 0);
156 	if (irq > 0)
157 		goto out;
158 
159 	if (irq != -EPROBE_DEFER)
160 		dev_err(dwc->dev, "missing OTG IRQ\n");
161 
162 	if (!irq)
163 		irq = -EINVAL;
164 
165 out:
166 	return irq;
167 }
168 
169 void dwc3_otg_init(struct dwc3 *dwc)
170 {
171 	u32 reg;
172 
173 	/*
174 	 * As per Figure 11-4 OTG Driver Overall Programming Flow,
175 	 * block "Initialize GCTL for OTG operation".
176 	 */
177 	/* GCTL.PrtCapDir=2'b11 */
178 	dwc3_set_prtcap(dwc, DWC3_GCTL_PRTCAP_OTG);
179 	/* GUSB2PHYCFG0.SusPHY=0 */
180 	reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
181 	reg &= ~DWC3_GUSB2PHYCFG_SUSPHY;
182 	dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
183 
184 	/* Initialize OTG registers */
185 	dwc3_otgregs_init(dwc);
186 }
187 
188 void dwc3_otg_exit(struct dwc3 *dwc)
189 {
190 	/* disable all OTG IRQs */
191 	dwc3_otg_disable_events(dwc, DWC3_OTG_ALL_EVENTS);
192 	/* clear all events */
193 	dwc3_otg_clear_events(dwc);
194 }
195 
196 /* should be called before Host controller driver is started */
197 void dwc3_otg_host_init(struct dwc3 *dwc)
198 {
199 	u32 reg;
200 
201 	/* As per Figure 11-10 A-Device Flow Diagram */
202 	/* OCFG.HNPCap = 0, OCFG.SRPCap = 0. Already 0 */
203 
204 	/*
205 	 * OCTL.PeriMode=0, OCTL.TermSelDLPulse = 0,
206 	 * OCTL.DevSetHNPEn = 0, OCTL.HstSetHNPEn = 0
207 	 */
208 	reg = dwc3_readl(dwc->regs, DWC3_OCTL);
209 	reg &= ~(DWC3_OCTL_PERIMODE | DWC3_OCTL_TERMSELIDPULSE |
210 			DWC3_OCTL_DEVSETHNPEN | DWC3_OCTL_HSTSETHNPEN);
211 	dwc3_writel(dwc->regs, DWC3_OCTL, reg);
212 
213 	/*
214 	 * OCFG.DisPrtPwrCutoff = 0/1
215 	 */
216 	reg = dwc3_readl(dwc->regs, DWC3_OCFG);
217 	reg &= ~DWC3_OCFG_DISPWRCUTTOFF;
218 	dwc3_writel(dwc->regs, DWC3_OCFG, reg);
219 
220 	/*
221 	 * OCFG.SRPCap = 1, OCFG.HNPCap = GHWPARAMS6.HNP_CAP
222 	 * We don't want SRP/HNP for simple dual-role so leave
223 	 * these disabled.
224 	 */
225 
226 	/*
227 	 * OEVTEN.OTGADevHostEvntEn = 1
228 	 * OEVTEN.OTGADevSessEndDetEvntEn = 1
229 	 * We don't want HNP/role-swap so leave these disabled.
230 	 */
231 
232 	/* GUSB2PHYCFG.ULPIAutoRes = 1/0, GUSB2PHYCFG.SusPHY = 1 */
233 	if (!dwc->dis_u2_susphy_quirk) {
234 		reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
235 		reg |= DWC3_GUSB2PHYCFG_SUSPHY;
236 		dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
237 	}
238 
239 	/* Set Port Power to enable VBUS: OCTL.PrtPwrCtl = 1 */
240 	reg = dwc3_readl(dwc->regs, DWC3_OCTL);
241 	reg |= DWC3_OCTL_PRTPWRCTL;
242 	dwc3_writel(dwc->regs, DWC3_OCTL, reg);
243 }
244 
245 /* should be called after Host controller driver is stopped */
246 static void dwc3_otg_host_exit(struct dwc3 *dwc)
247 {
248 	u32 reg;
249 
250 	/*
251 	 * Exit from A-device flow as per
252 	 * Figure 11-4 OTG Driver Overall Programming Flow
253 	 */
254 
255 	/*
256 	 * OEVTEN.OTGADevBHostEndEvntEn=0, OEVTEN.OTGADevHNPChngEvntEn=0
257 	 * OEVTEN.OTGADevSessEndDetEvntEn=0,
258 	 * OEVTEN.OTGADevHostEvntEn = 0
259 	 * But we don't disable any OTG events
260 	 */
261 
262 	/* OCTL.HstSetHNPEn = 0, OCTL.PrtPwrCtl=0 */
263 	reg = dwc3_readl(dwc->regs, DWC3_OCTL);
264 	reg &= ~(DWC3_OCTL_HSTSETHNPEN | DWC3_OCTL_PRTPWRCTL);
265 	dwc3_writel(dwc->regs, DWC3_OCTL, reg);
266 }
267 
268 /* should be called before the gadget controller driver is started */
269 static void dwc3_otg_device_init(struct dwc3 *dwc)
270 {
271 	u32 reg;
272 
273 	/* As per Figure 11-20 B-Device Flow Diagram */
274 
275 	/*
276 	 * OCFG.HNPCap = GHWPARAMS6.HNP_CAP, OCFG.SRPCap = 1
277 	 * but we keep them 0 for simple dual-role operation.
278 	 */
279 	reg = dwc3_readl(dwc->regs, DWC3_OCFG);
280 	/* OCFG.OTGSftRstMsk = 0/1 */
281 	reg |= DWC3_OCFG_SFTRSTMASK;
282 	dwc3_writel(dwc->regs, DWC3_OCFG, reg);
283 	/*
284 	 * OCTL.PeriMode = 1
285 	 * OCTL.TermSelDLPulse = 0/1, OCTL.HNPReq = 0
286 	 * OCTL.DevSetHNPEn = 0, OCTL.HstSetHNPEn = 0
287 	 */
288 	reg = dwc3_readl(dwc->regs, DWC3_OCTL);
289 	reg |= DWC3_OCTL_PERIMODE;
290 	reg &= ~(DWC3_OCTL_TERMSELIDPULSE | DWC3_OCTL_HNPREQ |
291 			DWC3_OCTL_DEVSETHNPEN | DWC3_OCTL_HSTSETHNPEN);
292 	dwc3_writel(dwc->regs, DWC3_OCTL, reg);
293 	/* OEVTEN.OTGBDevSesVldDetEvntEn = 1 */
294 	dwc3_otg_enable_events(dwc, DWC3_OEVTEN_BDEVSESSVLDDETEN);
295 	/* GUSB2PHYCFG.ULPIAutoRes = 0, GUSB2PHYCFG0.SusPHY = 1 */
296 	if (!dwc->dis_u2_susphy_quirk) {
297 		reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
298 		reg |= DWC3_GUSB2PHYCFG_SUSPHY;
299 		dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
300 	}
301 	/* GCTL.GblHibernationEn = 0. Already 0. */
302 }
303 
304 /* should be called after the gadget controller driver is stopped */
305 static void dwc3_otg_device_exit(struct dwc3 *dwc)
306 {
307 	u32 reg;
308 
309 	/*
310 	 * Exit from B-device flow as per
311 	 * Figure 11-4 OTG Driver Overall Programming Flow
312 	 */
313 
314 	/*
315 	 * OEVTEN.OTGBDevHNPChngEvntEn = 0
316 	 * OEVTEN.OTGBDevVBusChngEvntEn = 0
317 	 * OEVTEN.OTGBDevBHostEndEvntEn = 0
318 	 */
319 	dwc3_otg_disable_events(dwc, DWC3_OEVTEN_BDEVHNPCHNGEN |
320 				DWC3_OEVTEN_BDEVVBUSCHNGEN |
321 				DWC3_OEVTEN_BDEVBHOSTENDEN);
322 
323 	/* OCTL.DevSetHNPEn = 0, OCTL.HNPReq = 0, OCTL.PeriMode=1 */
324 	reg = dwc3_readl(dwc->regs, DWC3_OCTL);
325 	reg &= ~(DWC3_OCTL_DEVSETHNPEN | DWC3_OCTL_HNPREQ);
326 	reg |= DWC3_OCTL_PERIMODE;
327 	dwc3_writel(dwc->regs, DWC3_OCTL, reg);
328 }
329 
330 void dwc3_otg_update(struct dwc3 *dwc, bool ignore_idstatus)
331 {
332 	int ret;
333 	u32 reg;
334 	int id;
335 	unsigned long flags;
336 
337 	if (dwc->dr_mode != USB_DR_MODE_OTG)
338 		return;
339 
340 	/* don't do anything if debug user changed role to not OTG */
341 	if (dwc->current_dr_role != DWC3_GCTL_PRTCAP_OTG)
342 		return;
343 
344 	if (!ignore_idstatus) {
345 		reg = dwc3_readl(dwc->regs, DWC3_OSTS);
346 		id = !!(reg & DWC3_OSTS_CONIDSTS);
347 
348 		dwc->desired_otg_role = id ? DWC3_OTG_ROLE_DEVICE :
349 					DWC3_OTG_ROLE_HOST;
350 	}
351 
352 	if (dwc->desired_otg_role == dwc->current_otg_role)
353 		return;
354 
355 	switch (dwc->current_otg_role) {
356 	case DWC3_OTG_ROLE_HOST:
357 		dwc3_host_exit(dwc);
358 		spin_lock_irqsave(&dwc->lock, flags);
359 		dwc3_otg_host_exit(dwc);
360 		spin_unlock_irqrestore(&dwc->lock, flags);
361 		break;
362 	case DWC3_OTG_ROLE_DEVICE:
363 		dwc3_gadget_exit(dwc);
364 		spin_lock_irqsave(&dwc->lock, flags);
365 		dwc3_event_buffers_cleanup(dwc);
366 		dwc3_otg_device_exit(dwc);
367 		spin_unlock_irqrestore(&dwc->lock, flags);
368 		break;
369 	default:
370 		break;
371 	}
372 
373 	spin_lock_irqsave(&dwc->lock, flags);
374 
375 	dwc->current_otg_role = dwc->desired_otg_role;
376 
377 	spin_unlock_irqrestore(&dwc->lock, flags);
378 
379 	switch (dwc->desired_otg_role) {
380 	case DWC3_OTG_ROLE_HOST:
381 		spin_lock_irqsave(&dwc->lock, flags);
382 		dwc3_otgregs_init(dwc);
383 		dwc3_otg_host_init(dwc);
384 		spin_unlock_irqrestore(&dwc->lock, flags);
385 		ret = dwc3_host_init(dwc);
386 		if (ret) {
387 			dev_err(dwc->dev, "failed to initialize host\n");
388 		} else {
389 			if (dwc->usb2_phy)
390 				otg_set_vbus(dwc->usb2_phy->otg, true);
391 			if (dwc->usb2_generic_phy)
392 				phy_set_mode(dwc->usb2_generic_phy,
393 					     PHY_MODE_USB_HOST);
394 		}
395 		break;
396 	case DWC3_OTG_ROLE_DEVICE:
397 		spin_lock_irqsave(&dwc->lock, flags);
398 		dwc3_otgregs_init(dwc);
399 		dwc3_otg_device_init(dwc);
400 		dwc3_event_buffers_setup(dwc);
401 		spin_unlock_irqrestore(&dwc->lock, flags);
402 
403 		if (dwc->usb2_phy)
404 			otg_set_vbus(dwc->usb2_phy->otg, false);
405 		if (dwc->usb2_generic_phy)
406 			phy_set_mode(dwc->usb2_generic_phy,
407 				     PHY_MODE_USB_DEVICE);
408 		ret = dwc3_gadget_init(dwc);
409 		if (ret)
410 			dev_err(dwc->dev, "failed to initialize peripheral\n");
411 		break;
412 	default:
413 		break;
414 	}
415 }
416 
417 static void dwc3_drd_update(struct dwc3 *dwc)
418 {
419 	int id;
420 
421 	if (dwc->edev) {
422 		id = extcon_get_state(dwc->edev, EXTCON_USB_HOST);
423 		if (id < 0)
424 			id = 0;
425 		dwc3_set_mode(dwc, id ?
426 			      DWC3_GCTL_PRTCAP_HOST :
427 			      DWC3_GCTL_PRTCAP_DEVICE);
428 	}
429 }
430 
431 static int dwc3_drd_notifier(struct notifier_block *nb,
432 			     unsigned long event, void *ptr)
433 {
434 	struct dwc3 *dwc = container_of(nb, struct dwc3, edev_nb);
435 
436 	dwc3_set_mode(dwc, event ?
437 		      DWC3_GCTL_PRTCAP_HOST :
438 		      DWC3_GCTL_PRTCAP_DEVICE);
439 
440 	return NOTIFY_DONE;
441 }
442 
443 static struct extcon_dev *dwc3_get_extcon(struct dwc3 *dwc)
444 {
445 	struct device *dev = dwc->dev;
446 	struct device_node *np_phy, *np_conn;
447 	struct extcon_dev *edev;
448 
449 	if (of_property_read_bool(dev->of_node, "extcon"))
450 		return extcon_get_edev_by_phandle(dwc->dev, 0);
451 
452 	np_phy = of_parse_phandle(dev->of_node, "phys", 0);
453 	np_conn = of_graph_get_remote_node(np_phy, -1, -1);
454 
455 	if (np_conn)
456 		edev = extcon_find_edev_by_node(np_conn);
457 	else
458 		edev = NULL;
459 
460 	of_node_put(np_conn);
461 	of_node_put(np_phy);
462 
463 	return edev;
464 }
465 
466 int dwc3_drd_init(struct dwc3 *dwc)
467 {
468 	int ret, irq;
469 
470 	dwc->edev = dwc3_get_extcon(dwc);
471 	if (IS_ERR(dwc->edev))
472 		return PTR_ERR(dwc->edev);
473 
474 	if (dwc->edev) {
475 		dwc->edev_nb.notifier_call = dwc3_drd_notifier;
476 		ret = extcon_register_notifier(dwc->edev, EXTCON_USB_HOST,
477 					       &dwc->edev_nb);
478 		if (ret < 0) {
479 			dev_err(dwc->dev, "couldn't register cable notifier\n");
480 			return ret;
481 		}
482 
483 		dwc3_drd_update(dwc);
484 	} else {
485 		dwc3_set_prtcap(dwc, DWC3_GCTL_PRTCAP_OTG);
486 		dwc->current_dr_role = DWC3_GCTL_PRTCAP_OTG;
487 
488 		/* use OTG block to get ID event */
489 		irq = dwc3_otg_get_irq(dwc);
490 		if (irq < 0)
491 			return irq;
492 
493 		dwc->otg_irq = irq;
494 
495 		/* disable all OTG IRQs */
496 		dwc3_otg_disable_events(dwc, DWC3_OTG_ALL_EVENTS);
497 		/* clear all events */
498 		dwc3_otg_clear_events(dwc);
499 
500 		ret = request_threaded_irq(dwc->otg_irq, dwc3_otg_irq,
501 					   dwc3_otg_thread_irq,
502 					   IRQF_SHARED, "dwc3-otg", dwc);
503 		if (ret) {
504 			dev_err(dwc->dev, "failed to request irq #%d --> %d\n",
505 				dwc->otg_irq, ret);
506 			ret = -ENODEV;
507 			return ret;
508 		}
509 
510 		dwc3_otg_init(dwc);
511 		dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_OTG);
512 	}
513 
514 	return 0;
515 }
516 
517 void dwc3_drd_exit(struct dwc3 *dwc)
518 {
519 	unsigned long flags;
520 
521 	if (dwc->edev)
522 		extcon_unregister_notifier(dwc->edev, EXTCON_USB_HOST,
523 					   &dwc->edev_nb);
524 
525 	cancel_work_sync(&dwc->drd_work);
526 
527 	/* debug user might have changed role, clean based on current role */
528 	switch (dwc->current_dr_role) {
529 	case DWC3_GCTL_PRTCAP_HOST:
530 		dwc3_host_exit(dwc);
531 		break;
532 	case DWC3_GCTL_PRTCAP_DEVICE:
533 		dwc3_gadget_exit(dwc);
534 		dwc3_event_buffers_cleanup(dwc);
535 		break;
536 	case DWC3_GCTL_PRTCAP_OTG:
537 		dwc3_otg_exit(dwc);
538 		spin_lock_irqsave(&dwc->lock, flags);
539 		dwc->desired_otg_role = DWC3_OTG_ROLE_IDLE;
540 		spin_unlock_irqrestore(&dwc->lock, flags);
541 		dwc3_otg_update(dwc, 1);
542 		break;
543 	default:
544 		break;
545 	}
546 
547 	if (!dwc->edev)
548 		free_irq(dwc->otg_irq, dwc);
549 }
550