xref: /linux/drivers/usb/musb/musb_virthub.c (revision 60684c2bd35064043360e6f716d1b7c20e967b7d)
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_set_state(musb, 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 	u8		power;
54 	void __iomem	*mbase = musb->mregs;
55 
56 	if (!is_host_active(musb))
57 		return 0;
58 
59 	/* NOTE:  this doesn't necessarily put PHY into low power mode,
60 	 * turning off its clock; that's a function of PHY integration and
61 	 * MUSB_POWER_ENSUSPEND.  PHY may need a clock (sigh) to detect
62 	 * SE0 changing to connect (J) or wakeup (K) states.
63 	 */
64 	power = musb_readb(mbase, MUSB_POWER);
65 	if (do_suspend) {
66 		int retries = 10000;
67 
68 		if (power & MUSB_POWER_RESUME)
69 			return -EBUSY;
70 
71 		if (!(power & MUSB_POWER_SUSPENDM)) {
72 			power |= MUSB_POWER_SUSPENDM;
73 			musb_writeb(mbase, MUSB_POWER, power);
74 
75 			/* Needed for OPT A tests */
76 			power = musb_readb(mbase, MUSB_POWER);
77 			while (power & MUSB_POWER_SUSPENDM) {
78 				power = musb_readb(mbase, MUSB_POWER);
79 				if (retries-- < 1)
80 					break;
81 			}
82 		}
83 
84 		musb_dbg(musb, "Root port suspended, power %02x", power);
85 
86 		musb->port1_status |= USB_PORT_STAT_SUSPEND;
87 		switch (musb_get_state(musb)) {
88 		case OTG_STATE_A_HOST:
89 			musb_set_state(musb, OTG_STATE_A_SUSPEND);
90 			musb->is_active = musb->xceiv &&
91 				musb->xceiv->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_set_state(musb, OTG_STATE_B_WAIT_ACON);
100 			musb->is_active = musb->xceiv &&
101 				musb->xceiv->otg->host->b_hnp_enable;
102 			musb_platform_try_idle(musb, 0);
103 			break;
104 		default:
105 			musb_dbg(musb, "bogus rh suspend? %s",
106 				 musb_otg_state_string(musb));
107 		}
108 	} else if (power & MUSB_POWER_SUSPENDM) {
109 		power &= ~MUSB_POWER_SUSPENDM;
110 		power |= MUSB_POWER_RESUME;
111 		musb_writeb(mbase, MUSB_POWER, power);
112 
113 		musb_dbg(musb, "Root port resuming, power %02x", power);
114 
115 		musb->port1_status |= MUSB_PORT_STAT_RESUME;
116 		schedule_delayed_work(&musb->finish_resume_work,
117 				      msecs_to_jiffies(USB_RESUME_TIMEOUT));
118 	}
119 	return 0;
120 }
121 
122 void musb_port_reset(struct musb *musb, bool do_reset)
123 {
124 	u8		power;
125 	void __iomem	*mbase = musb->mregs;
126 
127 	if (musb_get_state(musb) == OTG_STATE_B_IDLE) {
128 		musb_dbg(musb, "HNP: Returning from HNP; no hub reset from b_idle");
129 		musb->port1_status &= ~USB_PORT_STAT_RESET;
130 		return;
131 	}
132 
133 	if (!is_host_active(musb))
134 		return;
135 
136 	/* NOTE:  caller guarantees it will turn off the reset when
137 	 * the appropriate amount of time has passed
138 	 */
139 	power = musb_readb(mbase, MUSB_POWER);
140 	if (do_reset) {
141 		/*
142 		 * If RESUME is set, we must make sure it stays minimum 20 ms.
143 		 * Then we must clear RESUME and wait a bit to let musb start
144 		 * generating SOFs. If we don't do this, OPT HS A 6.8 tests
145 		 * fail with "Error! Did not receive an SOF before suspend
146 		 * detected".
147 		 */
148 		if (power &  MUSB_POWER_RESUME) {
149 			long remain = (unsigned long) musb->rh_timer - jiffies;
150 
151 			if (musb->rh_timer > 0 && remain > 0) {
152 				/* take into account the minimum delay after resume */
153 				schedule_delayed_work(
154 					&musb->deassert_reset_work, remain);
155 				return;
156 			}
157 
158 			musb_writeb(mbase, MUSB_POWER,
159 				    power & ~MUSB_POWER_RESUME);
160 
161 			/* Give the core 1 ms to clear MUSB_POWER_RESUME */
162 			schedule_delayed_work(&musb->deassert_reset_work,
163 					      msecs_to_jiffies(1));
164 			return;
165 		}
166 
167 		power &= 0xf0;
168 		musb_writeb(mbase, MUSB_POWER,
169 				power | MUSB_POWER_RESET);
170 
171 		musb->port1_status |= USB_PORT_STAT_RESET;
172 		musb->port1_status &= ~USB_PORT_STAT_ENABLE;
173 		schedule_delayed_work(&musb->deassert_reset_work,
174 				      msecs_to_jiffies(50));
175 	} else {
176 		musb_dbg(musb, "root port reset stopped");
177 		musb_platform_pre_root_reset_end(musb);
178 		musb_writeb(mbase, MUSB_POWER,
179 				power & ~MUSB_POWER_RESET);
180 		musb_platform_post_root_reset_end(musb);
181 
182 		power = musb_readb(mbase, MUSB_POWER);
183 		if (power & MUSB_POWER_HSMODE) {
184 			musb_dbg(musb, "high-speed device connected");
185 			musb->port1_status |= USB_PORT_STAT_HIGH_SPEED;
186 		}
187 
188 		musb->port1_status &= ~USB_PORT_STAT_RESET;
189 		musb->port1_status |= USB_PORT_STAT_ENABLE
190 					| (USB_PORT_STAT_C_RESET << 16)
191 					| (USB_PORT_STAT_C_ENABLE << 16);
192 		usb_hcd_poll_rh_status(musb->hcd);
193 
194 		musb->vbuserr_retry = VBUSERR_RETRY_COUNT;
195 	}
196 }
197 
198 void musb_root_disconnect(struct musb *musb)
199 {
200 	musb->port1_status = USB_PORT_STAT_POWER
201 			| (USB_PORT_STAT_C_CONNECTION << 16);
202 
203 	usb_hcd_poll_rh_status(musb->hcd);
204 	musb->is_active = 0;
205 
206 	switch (musb_get_state(musb)) {
207 	case OTG_STATE_A_SUSPEND:
208 		if (musb->xceiv && musb->xceiv->otg->host->b_hnp_enable) {
209 			musb_set_state(musb, OTG_STATE_A_PERIPHERAL);
210 			musb->g.is_a_peripheral = 1;
211 			break;
212 		}
213 		fallthrough;
214 	case OTG_STATE_A_HOST:
215 		musb_set_state(musb, OTG_STATE_A_WAIT_BCON);
216 		musb->is_active = 0;
217 		break;
218 	case OTG_STATE_A_WAIT_VFALL:
219 		musb_set_state(musb, OTG_STATE_B_IDLE);
220 		break;
221 	default:
222 		musb_dbg(musb, "host disconnect (%s)",
223 			 musb_otg_state_string(musb));
224 	}
225 }
226 EXPORT_SYMBOL_GPL(musb_root_disconnect);
227 
228 
229 /*---------------------------------------------------------------------*/
230 
231 /* Caller may or may not hold musb->lock */
232 int musb_hub_status_data(struct usb_hcd *hcd, char *buf)
233 {
234 	struct musb	*musb = hcd_to_musb(hcd);
235 	int		retval = 0;
236 
237 	/* called in_irq() via usb_hcd_poll_rh_status() */
238 	if (musb->port1_status & 0xffff0000) {
239 		*buf = 0x02;
240 		retval = 1;
241 	}
242 	return retval;
243 }
244 
245 static int musb_has_gadget(struct musb *musb)
246 {
247 	/*
248 	 * In host-only mode we start a connection right away. In OTG mode
249 	 * we have to wait until we loaded a gadget. We don't really need a
250 	 * gadget if we operate as a host but we should not start a session
251 	 * as a device without a gadget or else we explode.
252 	 */
253 #ifdef CONFIG_USB_MUSB_HOST
254 	return 1;
255 #else
256 	return musb->port_mode == MUSB_HOST;
257 #endif
258 }
259 
260 int musb_hub_control(
261 	struct usb_hcd	*hcd,
262 	u16		typeReq,
263 	u16		wValue,
264 	u16		wIndex,
265 	char		*buf,
266 	u16		wLength)
267 {
268 	struct musb	*musb = hcd_to_musb(hcd);
269 	u32		temp;
270 	int		retval = 0;
271 	unsigned long	flags;
272 	bool		start_musb = false;
273 
274 	spin_lock_irqsave(&musb->lock, flags);
275 
276 	if (unlikely(!HCD_HW_ACCESSIBLE(hcd))) {
277 		spin_unlock_irqrestore(&musb->lock, flags);
278 		return -ESHUTDOWN;
279 	}
280 
281 	/* hub features:  always zero, setting is a NOP
282 	 * port features: reported, sometimes updated when host is active
283 	 * no indicators
284 	 */
285 	switch (typeReq) {
286 	case ClearHubFeature:
287 	case SetHubFeature:
288 		switch (wValue) {
289 		case C_HUB_OVER_CURRENT:
290 		case C_HUB_LOCAL_POWER:
291 			break;
292 		default:
293 			goto error;
294 		}
295 		break;
296 	case ClearPortFeature:
297 		if ((wIndex & 0xff) != 1)
298 			goto error;
299 
300 		switch (wValue) {
301 		case USB_PORT_FEAT_ENABLE:
302 			break;
303 		case USB_PORT_FEAT_SUSPEND:
304 			musb_port_suspend(musb, false);
305 			break;
306 		case USB_PORT_FEAT_POWER:
307 			if (!hcd->self.is_b_host)
308 				musb_platform_set_vbus(musb, 0);
309 			break;
310 		case USB_PORT_FEAT_C_CONNECTION:
311 		case USB_PORT_FEAT_C_ENABLE:
312 		case USB_PORT_FEAT_C_OVER_CURRENT:
313 		case USB_PORT_FEAT_C_RESET:
314 		case USB_PORT_FEAT_C_SUSPEND:
315 			break;
316 		default:
317 			goto error;
318 		}
319 		musb_dbg(musb, "clear feature %d", wValue);
320 		musb->port1_status &= ~(1 << wValue);
321 		break;
322 	case GetHubDescriptor:
323 		{
324 		struct usb_hub_descriptor *desc = (void *)buf;
325 
326 		desc->bDescLength = 9;
327 		desc->bDescriptorType = USB_DT_HUB;
328 		desc->bNbrPorts = 1;
329 		desc->wHubCharacteristics = cpu_to_le16(
330 			HUB_CHAR_INDV_PORT_LPSM /* per-port power switching */
331 			| HUB_CHAR_NO_OCPM	/* no overcurrent reporting */
332 			);
333 		desc->bPwrOn2PwrGood = 5;	/* msec/2 */
334 		desc->bHubContrCurrent = 0;
335 
336 		/* workaround bogus struct definition */
337 		desc->u.hs.DeviceRemovable[0] = 0x02;	/* port 1 */
338 		desc->u.hs.DeviceRemovable[1] = 0xff;
339 		}
340 		break;
341 	case GetHubStatus:
342 		temp = 0;
343 		*(__le32 *) buf = cpu_to_le32(temp);
344 		break;
345 	case GetPortStatus:
346 		if (wIndex != 1)
347 			goto error;
348 
349 		put_unaligned(cpu_to_le32(musb->port1_status
350 					& ~MUSB_PORT_STAT_RESUME),
351 				(__le32 *) buf);
352 
353 		/* port change status is more interesting */
354 		musb_dbg(musb, "port status %08x", musb->port1_status);
355 		break;
356 	case SetPortFeature:
357 		if ((wIndex & 0xff) != 1)
358 			goto error;
359 
360 		switch (wValue) {
361 		case USB_PORT_FEAT_POWER:
362 			/* NOTE: this controller has a strange state machine
363 			 * that involves "requesting sessions" according to
364 			 * magic side effects from incompletely-described
365 			 * rules about startup...
366 			 *
367 			 * This call is what really starts the host mode; be
368 			 * very careful about side effects if you reorder any
369 			 * initialization logic, e.g. for OTG, or change any
370 			 * logic relating to VBUS power-up.
371 			 */
372 			if (!hcd->self.is_b_host && musb_has_gadget(musb))
373 				start_musb = true;
374 			break;
375 		case USB_PORT_FEAT_RESET:
376 			musb_port_reset(musb, true);
377 			break;
378 		case USB_PORT_FEAT_SUSPEND:
379 			musb_port_suspend(musb, true);
380 			break;
381 		case USB_PORT_FEAT_TEST:
382 			if (unlikely(is_host_active(musb)))
383 				goto error;
384 
385 			wIndex >>= 8;
386 			switch (wIndex) {
387 			case USB_TEST_J:
388 				pr_debug("USB_TEST_J\n");
389 				temp = MUSB_TEST_J;
390 				break;
391 			case USB_TEST_K:
392 				pr_debug("USB_TEST_K\n");
393 				temp = MUSB_TEST_K;
394 				break;
395 			case USB_TEST_SE0_NAK:
396 				pr_debug("USB_TEST_SE0_NAK\n");
397 				temp = MUSB_TEST_SE0_NAK;
398 				break;
399 			case USB_TEST_PACKET:
400 				pr_debug("USB_TEST_PACKET\n");
401 				temp = MUSB_TEST_PACKET;
402 				musb_load_testpacket(musb);
403 				break;
404 			case USB_TEST_FORCE_ENABLE:
405 				pr_debug("USB_TEST_FORCE_ENABLE\n");
406 				temp = MUSB_TEST_FORCE_HOST
407 					| MUSB_TEST_FORCE_HS;
408 
409 				musb_writeb(musb->mregs, MUSB_DEVCTL,
410 						MUSB_DEVCTL_SESSION);
411 				break;
412 			case 6:
413 				pr_debug("TEST_FIFO_ACCESS\n");
414 				temp = MUSB_TEST_FIFO_ACCESS;
415 				break;
416 			default:
417 				goto error;
418 			}
419 			musb_writeb(musb->mregs, MUSB_TESTMODE, temp);
420 			break;
421 		default:
422 			goto error;
423 		}
424 		musb_dbg(musb, "set feature %d", wValue);
425 		musb->port1_status |= 1 << wValue;
426 		break;
427 
428 	default:
429 error:
430 		/* "protocol stall" on error */
431 		retval = -EPIPE;
432 	}
433 	spin_unlock_irqrestore(&musb->lock, flags);
434 
435 	if (start_musb)
436 		musb_start(musb);
437 
438 	return retval;
439 }
440