xref: /openbmc/linux/drivers/usb/musb/musb_virthub.c (revision be709d48)
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 
21 void 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 
51 int 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 
121 void 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 
197 void 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 }
227 EXPORT_SYMBOL_GPL(musb_root_disconnect);
228 
229 
230 /*---------------------------------------------------------------------*/
231 
232 /* Caller may or may not hold musb->lock */
233 int 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 
246 static 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 
261 int 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 1:
389 				pr_debug("TEST_J\n");
390 				temp = MUSB_TEST_J;
391 				break;
392 			case 2:
393 				pr_debug("TEST_K\n");
394 				temp = MUSB_TEST_K;
395 				break;
396 			case 3:
397 				pr_debug("TEST_SE0_NAK\n");
398 				temp = MUSB_TEST_SE0_NAK;
399 				break;
400 			case 4:
401 				pr_debug("TEST_PACKET\n");
402 				temp = MUSB_TEST_PACKET;
403 				musb_load_testpacket(musb);
404 				break;
405 			case 5:
406 				pr_debug("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:
430 error:
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