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  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
 17static 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
 25static 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
 33static 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
 50static 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
 67static 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
 91static 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
135static 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
164out:
165	return irq;
166}
167
168void 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
187void 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 */
196void 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 */
245static 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 */
268static 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 */
304static 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
329void 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
416static 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
430static 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
442int 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
495void 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}