1// SPDX-License-Identifier: GPL-2.0
2/*
3 * MUSB OTG driver virtual root hub support
4 *
5 * Copyright 2005 Mentor Graphics Corporation
6 * Copyright (C) 2005-2006 by Texas Instruments
7 * Copyright (C) 2006-2007 Nokia Corporation
8 */
9
10#include <linux/module.h>
11#include <linux/kernel.h>
12#include <linux/sched.h>
13#include <linux/errno.h>
14#include <linux/time.h>
15#include <linux/timer.h>
16
17#include <asm/unaligned.h>
18
19#include "musb_core.h"
20
21void musb_host_finish_resume(struct work_struct *work)
22{
23	struct musb *musb;
24	unsigned long flags;
25	u8 power;
26
27	musb = container_of(work, struct musb, finish_resume_work.work);
28
29	spin_lock_irqsave(&musb->lock, flags);
30
31	power = musb_readb(musb->mregs, MUSB_POWER);
32	power &= ~MUSB_POWER_RESUME;
33	musb_dbg(musb, "root port resume stopped, power %02x", power);
34	musb_writeb(musb->mregs, MUSB_POWER, power);
35
36	/*
37	 * ISSUE:  DaVinci (RTL 1.300) disconnects after
38	 * resume of high speed peripherals (but not full
39	 * speed ones).
40	 */
41	musb->is_active = 1;
42	musb->port1_status &= ~(USB_PORT_STAT_SUSPEND | MUSB_PORT_STAT_RESUME);
43	musb->port1_status |= USB_PORT_STAT_C_SUSPEND << 16;
44	usb_hcd_poll_rh_status(musb->hcd);
45	/* NOTE: it might really be A_WAIT_BCON ... */
46	musb->xceiv->otg->state = OTG_STATE_A_HOST;
47
48	spin_unlock_irqrestore(&musb->lock, flags);
49}
50
51int musb_port_suspend(struct musb *musb, bool do_suspend)
52{
53	struct usb_otg	*otg = musb->xceiv->otg;
54	u8		power;
55	void __iomem	*mbase = musb->mregs;
56
57	if (!is_host_active(musb))
58		return 0;
59
60	/* NOTE:  this doesn't necessarily put PHY into low power mode,
61	 * turning off its clock; that's a function of PHY integration and
62	 * MUSB_POWER_ENSUSPEND.  PHY may need a clock (sigh) to detect
63	 * SE0 changing to connect (J) or wakeup (K) states.
64	 */
65	power = musb_readb(mbase, MUSB_POWER);
66	if (do_suspend) {
67		int retries = 10000;
68
69		if (power & MUSB_POWER_RESUME)
70			return -EBUSY;
71
72		if (!(power & MUSB_POWER_SUSPENDM)) {
73			power |= MUSB_POWER_SUSPENDM;
74			musb_writeb(mbase, MUSB_POWER, power);
75
76			/* Needed for OPT A tests */
77			power = musb_readb(mbase, MUSB_POWER);
78			while (power & MUSB_POWER_SUSPENDM) {
79				power = musb_readb(mbase, MUSB_POWER);
80				if (retries-- < 1)
81					break;
82			}
83		}
84
85		musb_dbg(musb, "Root port suspended, power %02x", power);
86
87		musb->port1_status |= USB_PORT_STAT_SUSPEND;
88		switch (musb->xceiv->otg->state) {
89		case OTG_STATE_A_HOST:
90			musb->xceiv->otg->state = OTG_STATE_A_SUSPEND;
91			musb->is_active = otg->host->b_hnp_enable;
92			if (musb->is_active)
93				mod_timer(&musb->otg_timer, jiffies
94					+ msecs_to_jiffies(
95						OTG_TIME_A_AIDL_BDIS));
96			musb_platform_try_idle(musb, 0);
97			break;
98		case OTG_STATE_B_HOST:
99			musb->xceiv->otg->state = OTG_STATE_B_WAIT_ACON;
100			musb->is_active = otg->host->b_hnp_enable;
101			musb_platform_try_idle(musb, 0);
102			break;
103		default:
104			musb_dbg(musb, "bogus rh suspend? %s",
105				usb_otg_state_string(musb->xceiv->otg->state));
106		}
107	} else if (power & MUSB_POWER_SUSPENDM) {
108		power &= ~MUSB_POWER_SUSPENDM;
109		power |= MUSB_POWER_RESUME;
110		musb_writeb(mbase, MUSB_POWER, power);
111
112		musb_dbg(musb, "Root port resuming, power %02x", power);
113
114		musb->port1_status |= MUSB_PORT_STAT_RESUME;
115		schedule_delayed_work(&musb->finish_resume_work,
116				      msecs_to_jiffies(USB_RESUME_TIMEOUT));
117	}
118	return 0;
119}
120
121void musb_port_reset(struct musb *musb, bool do_reset)
122{
123	u8		power;
124	void __iomem	*mbase = musb->mregs;
125
126	if (musb->xceiv->otg->state == OTG_STATE_B_IDLE) {
127		musb_dbg(musb, "HNP: Returning from HNP; no hub reset from b_idle");
128		musb->port1_status &= ~USB_PORT_STAT_RESET;
129		return;
130	}
131
132	if (!is_host_active(musb))
133		return;
134
135	/* NOTE:  caller guarantees it will turn off the reset when
136	 * the appropriate amount of time has passed
137	 */
138	power = musb_readb(mbase, MUSB_POWER);
139	if (do_reset) {
140		/*
141		 * If RESUME is set, we must make sure it stays minimum 20 ms.
142		 * Then we must clear RESUME and wait a bit to let musb start
143		 * generating SOFs. If we don't do this, OPT HS A 6.8 tests
144		 * fail with "Error! Did not receive an SOF before suspend
145		 * detected".
146		 */
147		if (power &  MUSB_POWER_RESUME) {
148			long remain = (unsigned long) musb->rh_timer - jiffies;
149
150			if (musb->rh_timer > 0 && remain > 0) {
151				/* take into account the minimum delay after resume */
152				schedule_delayed_work(
153					&musb->deassert_reset_work, remain);
154				return;
155			}
156
157			musb_writeb(mbase, MUSB_POWER,
158				    power & ~MUSB_POWER_RESUME);
159
160			/* Give the core 1 ms to clear MUSB_POWER_RESUME */
161			schedule_delayed_work(&musb->deassert_reset_work,
162					      msecs_to_jiffies(1));
163			return;
164		}
165
166		power &= 0xf0;
167		musb_writeb(mbase, MUSB_POWER,
168				power | MUSB_POWER_RESET);
169
170		musb->port1_status |= USB_PORT_STAT_RESET;
171		musb->port1_status &= ~USB_PORT_STAT_ENABLE;
172		schedule_delayed_work(&musb->deassert_reset_work,
173				      msecs_to_jiffies(50));
174	} else {
175		musb_dbg(musb, "root port reset stopped");
176		musb_platform_pre_root_reset_end(musb);
177		musb_writeb(mbase, MUSB_POWER,
178				power & ~MUSB_POWER_RESET);
179		musb_platform_post_root_reset_end(musb);
180
181		power = musb_readb(mbase, MUSB_POWER);
182		if (power & MUSB_POWER_HSMODE) {
183			musb_dbg(musb, "high-speed device connected");
184			musb->port1_status |= USB_PORT_STAT_HIGH_SPEED;
185		}
186
187		musb->port1_status &= ~USB_PORT_STAT_RESET;
188		musb->port1_status |= USB_PORT_STAT_ENABLE
189					| (USB_PORT_STAT_C_RESET << 16)
190					| (USB_PORT_STAT_C_ENABLE << 16);
191		usb_hcd_poll_rh_status(musb->hcd);
192
193		musb->vbuserr_retry = VBUSERR_RETRY_COUNT;
194	}
195}
196
197void musb_root_disconnect(struct musb *musb)
198{
199	struct usb_otg	*otg = musb->xceiv->otg;
200
201	musb->port1_status = USB_PORT_STAT_POWER
202			| (USB_PORT_STAT_C_CONNECTION << 16);
203
204	usb_hcd_poll_rh_status(musb->hcd);
205	musb->is_active = 0;
206
207	switch (musb->xceiv->otg->state) {
208	case OTG_STATE_A_SUSPEND:
209		if (otg->host->b_hnp_enable) {
210			musb->xceiv->otg->state = OTG_STATE_A_PERIPHERAL;
211			musb->g.is_a_peripheral = 1;
212			break;
213		}
214		fallthrough;
215	case OTG_STATE_A_HOST:
216		musb->xceiv->otg->state = OTG_STATE_A_WAIT_BCON;
217		musb->is_active = 0;
218		break;
219	case OTG_STATE_A_WAIT_VFALL:
220		musb->xceiv->otg->state = OTG_STATE_B_IDLE;
221		break;
222	default:
223		musb_dbg(musb, "host disconnect (%s)",
224			usb_otg_state_string(musb->xceiv->otg->state));
225	}
226}
227EXPORT_SYMBOL_GPL(musb_root_disconnect);
228
229
230/*---------------------------------------------------------------------*/
231
232/* Caller may or may not hold musb->lock */
233int musb_hub_status_data(struct usb_hcd *hcd, char *buf)
234{
235	struct musb	*musb = hcd_to_musb(hcd);
236	int		retval = 0;
237
238	/* called in_irq() via usb_hcd_poll_rh_status() */
239	if (musb->port1_status & 0xffff0000) {
240		*buf = 0x02;
241		retval = 1;
242	}
243	return retval;
244}
245
246static int musb_has_gadget(struct musb *musb)
247{
248	/*
249	 * In host-only mode we start a connection right away. In OTG mode
250	 * we have to wait until we loaded a gadget. We don't really need a
251	 * gadget if we operate as a host but we should not start a session
252	 * as a device without a gadget or else we explode.
253	 */
254#ifdef CONFIG_USB_MUSB_HOST
255	return 1;
256#else
257	return musb->port_mode == MUSB_HOST;
258#endif
259}
260
261int musb_hub_control(
262	struct usb_hcd	*hcd,
263	u16		typeReq,
264	u16		wValue,
265	u16		wIndex,
266	char		*buf,
267	u16		wLength)
268{
269	struct musb	*musb = hcd_to_musb(hcd);
270	u32		temp;
271	int		retval = 0;
272	unsigned long	flags;
273	bool		start_musb = false;
274
275	spin_lock_irqsave(&musb->lock, flags);
276
277	if (unlikely(!HCD_HW_ACCESSIBLE(hcd))) {
278		spin_unlock_irqrestore(&musb->lock, flags);
279		return -ESHUTDOWN;
280	}
281
282	/* hub features:  always zero, setting is a NOP
283	 * port features: reported, sometimes updated when host is active
284	 * no indicators
285	 */
286	switch (typeReq) {
287	case ClearHubFeature:
288	case SetHubFeature:
289		switch (wValue) {
290		case C_HUB_OVER_CURRENT:
291		case C_HUB_LOCAL_POWER:
292			break;
293		default:
294			goto error;
295		}
296		break;
297	case ClearPortFeature:
298		if ((wIndex & 0xff) != 1)
299			goto error;
300
301		switch (wValue) {
302		case USB_PORT_FEAT_ENABLE:
303			break;
304		case USB_PORT_FEAT_SUSPEND:
305			musb_port_suspend(musb, false);
306			break;
307		case USB_PORT_FEAT_POWER:
308			if (!hcd->self.is_b_host)
309				musb_platform_set_vbus(musb, 0);
310			break;
311		case USB_PORT_FEAT_C_CONNECTION:
312		case USB_PORT_FEAT_C_ENABLE:
313		case USB_PORT_FEAT_C_OVER_CURRENT:
314		case USB_PORT_FEAT_C_RESET:
315		case USB_PORT_FEAT_C_SUSPEND:
316			break;
317		default:
318			goto error;
319		}
320		musb_dbg(musb, "clear feature %d", wValue);
321		musb->port1_status &= ~(1 << wValue);
322		break;
323	case GetHubDescriptor:
324		{
325		struct usb_hub_descriptor *desc = (void *)buf;
326
327		desc->bDescLength = 9;
328		desc->bDescriptorType = USB_DT_HUB;
329		desc->bNbrPorts = 1;
330		desc->wHubCharacteristics = cpu_to_le16(
331			HUB_CHAR_INDV_PORT_LPSM /* per-port power switching */
332			| HUB_CHAR_NO_OCPM	/* no overcurrent reporting */
333			);
334		desc->bPwrOn2PwrGood = 5;	/* msec/2 */
335		desc->bHubContrCurrent = 0;
336
337		/* workaround bogus struct definition */
338		desc->u.hs.DeviceRemovable[0] = 0x02;	/* port 1 */
339		desc->u.hs.DeviceRemovable[1] = 0xff;
340		}
341		break;
342	case GetHubStatus:
343		temp = 0;
344		*(__le32 *) buf = cpu_to_le32(temp);
345		break;
346	case GetPortStatus:
347		if (wIndex != 1)
348			goto error;
349
350		put_unaligned(cpu_to_le32(musb->port1_status
351					& ~MUSB_PORT_STAT_RESUME),
352				(__le32 *) buf);
353
354		/* port change status is more interesting */
355		musb_dbg(musb, "port status %08x", musb->port1_status);
356		break;
357	case SetPortFeature:
358		if ((wIndex & 0xff) != 1)
359			goto error;
360
361		switch (wValue) {
362		case USB_PORT_FEAT_POWER:
363			/* NOTE: this controller has a strange state machine
364			 * that involves "requesting sessions" according to
365			 * magic side effects from incompletely-described
366			 * rules about startup...
367			 *
368			 * This call is what really starts the host mode; be
369			 * very careful about side effects if you reorder any
370			 * initialization logic, e.g. for OTG, or change any
371			 * logic relating to VBUS power-up.
372			 */
373			if (!hcd->self.is_b_host && musb_has_gadget(musb))
374				start_musb = true;
375			break;
376		case USB_PORT_FEAT_RESET:
377			musb_port_reset(musb, true);
378			break;
379		case USB_PORT_FEAT_SUSPEND:
380			musb_port_suspend(musb, true);
381			break;
382		case USB_PORT_FEAT_TEST:
383			if (unlikely(is_host_active(musb)))
384				goto error;
385
386			wIndex >>= 8;
387			switch (wIndex) {
388			case USB_TEST_J:
389				pr_debug("USB_TEST_J\n");
390				temp = MUSB_TEST_J;
391				break;
392			case USB_TEST_K:
393				pr_debug("USB_TEST_K\n");
394				temp = MUSB_TEST_K;
395				break;
396			case USB_TEST_SE0_NAK:
397				pr_debug("USB_TEST_SE0_NAK\n");
398				temp = MUSB_TEST_SE0_NAK;
399				break;
400			case USB_TEST_PACKET:
401				pr_debug("USB_TEST_PACKET\n");
402				temp = MUSB_TEST_PACKET;
403				musb_load_testpacket(musb);
404				break;
405			case USB_TEST_FORCE_ENABLE:
406				pr_debug("USB_TEST_FORCE_ENABLE\n");
407				temp = MUSB_TEST_FORCE_HOST
408					| MUSB_TEST_FORCE_HS;
409
410				musb_writeb(musb->mregs, MUSB_DEVCTL,
411						MUSB_DEVCTL_SESSION);
412				break;
413			case 6:
414				pr_debug("TEST_FIFO_ACCESS\n");
415				temp = MUSB_TEST_FIFO_ACCESS;
416				break;
417			default:
418				goto error;
419			}
420			musb_writeb(musb->mregs, MUSB_TESTMODE, temp);
421			break;
422		default:
423			goto error;
424		}
425		musb_dbg(musb, "set feature %d", wValue);
426		musb->port1_status |= 1 << wValue;
427		break;
428
429	default:
430error:
431		/* "protocol stall" on error */
432		retval = -EPIPE;
433	}
434	spin_unlock_irqrestore(&musb->lock, flags);
435
436	if (start_musb)
437		musb_start(musb);
438
439	return retval;
440}
441