xref: /linux/drivers/usb/host/ohci-hub.c (revision c0c914eca7f251c70facc37dfebeaf176601918d)
1 /*
2  * OHCI HCD (Host Controller Driver) for USB.
3  *
4  * (C) Copyright 1999 Roman Weissgaerber <weissg@vienna.at>
5  * (C) Copyright 2000-2004 David Brownell <dbrownell@users.sourceforge.net>
6  *
7  * This file is licenced under GPL
8  */
9 
10 /*-------------------------------------------------------------------------*/
11 
12 /*
13  * OHCI Root Hub ... the nonsharable stuff
14  */
15 
16 #define dbg_port(hc,label,num,value) \
17 	ohci_dbg (hc, \
18 		"%s roothub.portstatus [%d] " \
19 		"= 0x%08x%s%s%s%s%s%s%s%s%s%s%s%s\n", \
20 		label, num, temp, \
21 		(temp & RH_PS_PRSC) ? " PRSC" : "", \
22 		(temp & RH_PS_OCIC) ? " OCIC" : "", \
23 		(temp & RH_PS_PSSC) ? " PSSC" : "", \
24 		(temp & RH_PS_PESC) ? " PESC" : "", \
25 		(temp & RH_PS_CSC) ? " CSC" : "", \
26 		\
27 		(temp & RH_PS_LSDA) ? " LSDA" : "", \
28 		(temp & RH_PS_PPS) ? " PPS" : "", \
29 		(temp & RH_PS_PRS) ? " PRS" : "", \
30 		(temp & RH_PS_POCI) ? " POCI" : "", \
31 		(temp & RH_PS_PSS) ? " PSS" : "", \
32 		\
33 		(temp & RH_PS_PES) ? " PES" : "", \
34 		(temp & RH_PS_CCS) ? " CCS" : "" \
35 		);
36 
37 /*-------------------------------------------------------------------------*/
38 
39 #define OHCI_SCHED_ENABLES \
40 	(OHCI_CTRL_CLE|OHCI_CTRL_BLE|OHCI_CTRL_PLE|OHCI_CTRL_IE)
41 
42 static void update_done_list(struct ohci_hcd *);
43 static void ohci_work(struct ohci_hcd *);
44 
45 #ifdef	CONFIG_PM
46 static int ohci_rh_suspend (struct ohci_hcd *ohci, int autostop)
47 __releases(ohci->lock)
48 __acquires(ohci->lock)
49 {
50 	int			status = 0;
51 
52 	ohci->hc_control = ohci_readl (ohci, &ohci->regs->control);
53 	switch (ohci->hc_control & OHCI_CTRL_HCFS) {
54 	case OHCI_USB_RESUME:
55 		ohci_dbg (ohci, "resume/suspend?\n");
56 		ohci->hc_control &= ~OHCI_CTRL_HCFS;
57 		ohci->hc_control |= OHCI_USB_RESET;
58 		ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
59 		(void) ohci_readl (ohci, &ohci->regs->control);
60 		/* FALL THROUGH */
61 	case OHCI_USB_RESET:
62 		status = -EBUSY;
63 		ohci_dbg (ohci, "needs reinit!\n");
64 		goto done;
65 	case OHCI_USB_SUSPEND:
66 		if (!ohci->autostop) {
67 			ohci_dbg (ohci, "already suspended\n");
68 			goto done;
69 		}
70 	}
71 	ohci_dbg (ohci, "%s root hub\n",
72 			autostop ? "auto-stop" : "suspend");
73 
74 	/* First stop any processing */
75 	if (!autostop && (ohci->hc_control & OHCI_SCHED_ENABLES)) {
76 		ohci->hc_control &= ~OHCI_SCHED_ENABLES;
77 		ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
78 		ohci->hc_control = ohci_readl (ohci, &ohci->regs->control);
79 		ohci_writel (ohci, OHCI_INTR_SF, &ohci->regs->intrstatus);
80 
81 		/* sched disables take effect on the next frame,
82 		 * then the last WDH could take 6+ msec
83 		 */
84 		ohci_dbg (ohci, "stopping schedules ...\n");
85 		ohci->autostop = 0;
86 		spin_unlock_irq (&ohci->lock);
87 		msleep (8);
88 		spin_lock_irq (&ohci->lock);
89 	}
90 	update_done_list(ohci);
91 	ohci_work(ohci);
92 
93 	/*
94 	 * Some controllers don't handle "global" suspend properly if
95 	 * there are unsuspended ports.  For these controllers, put all
96 	 * the enabled ports into suspend before suspending the root hub.
97 	 */
98 	if (ohci->flags & OHCI_QUIRK_GLOBAL_SUSPEND) {
99 		__hc32 __iomem	*portstat = ohci->regs->roothub.portstatus;
100 		int		i;
101 		unsigned	temp;
102 
103 		for (i = 0; i < ohci->num_ports; (++i, ++portstat)) {
104 			temp = ohci_readl(ohci, portstat);
105 			if ((temp & (RH_PS_PES | RH_PS_PSS)) ==
106 					RH_PS_PES)
107 				ohci_writel(ohci, RH_PS_PSS, portstat);
108 		}
109 	}
110 
111 	/* maybe resume can wake root hub */
112 	if (ohci_to_hcd(ohci)->self.root_hub->do_remote_wakeup || autostop) {
113 		ohci->hc_control |= OHCI_CTRL_RWE;
114 	} else {
115 		ohci_writel(ohci, OHCI_INTR_RHSC | OHCI_INTR_RD,
116 				&ohci->regs->intrdisable);
117 		ohci->hc_control &= ~OHCI_CTRL_RWE;
118 	}
119 
120 	/* Suspend hub ... this is the "global (to this bus) suspend" mode,
121 	 * which doesn't imply ports will first be individually suspended.
122 	 */
123 	ohci->hc_control &= ~OHCI_CTRL_HCFS;
124 	ohci->hc_control |= OHCI_USB_SUSPEND;
125 	ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
126 	(void) ohci_readl (ohci, &ohci->regs->control);
127 
128 	/* no resumes until devices finish suspending */
129 	if (!autostop) {
130 		ohci->next_statechange = jiffies + msecs_to_jiffies (5);
131 		ohci->autostop = 0;
132 		ohci->rh_state = OHCI_RH_SUSPENDED;
133 	}
134 
135 done:
136 	return status;
137 }
138 
139 static inline struct ed *find_head (struct ed *ed)
140 {
141 	/* for bulk and control lists */
142 	while (ed->ed_prev)
143 		ed = ed->ed_prev;
144 	return ed;
145 }
146 
147 /* caller has locked the root hub */
148 static int ohci_rh_resume (struct ohci_hcd *ohci)
149 __releases(ohci->lock)
150 __acquires(ohci->lock)
151 {
152 	struct usb_hcd		*hcd = ohci_to_hcd (ohci);
153 	u32			temp, enables;
154 	int			status = -EINPROGRESS;
155 	int			autostopped = ohci->autostop;
156 
157 	ohci->autostop = 0;
158 	ohci->hc_control = ohci_readl (ohci, &ohci->regs->control);
159 
160 	if (ohci->hc_control & (OHCI_CTRL_IR | OHCI_SCHED_ENABLES)) {
161 		/* this can happen after resuming a swsusp snapshot */
162 		if (ohci->rh_state != OHCI_RH_RUNNING) {
163 			ohci_dbg (ohci, "BIOS/SMM active, control %03x\n",
164 					ohci->hc_control);
165 			status = -EBUSY;
166 		/* this happens when pmcore resumes HC then root */
167 		} else {
168 			ohci_dbg (ohci, "duplicate resume\n");
169 			status = 0;
170 		}
171 	} else switch (ohci->hc_control & OHCI_CTRL_HCFS) {
172 	case OHCI_USB_SUSPEND:
173 		ohci->hc_control &= ~(OHCI_CTRL_HCFS|OHCI_SCHED_ENABLES);
174 		ohci->hc_control |= OHCI_USB_RESUME;
175 		ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
176 		(void) ohci_readl (ohci, &ohci->regs->control);
177 		ohci_dbg (ohci, "%s root hub\n",
178 				autostopped ? "auto-start" : "resume");
179 		break;
180 	case OHCI_USB_RESUME:
181 		/* HCFS changes sometime after INTR_RD */
182 		ohci_dbg(ohci, "%swakeup root hub\n",
183 				autostopped ? "auto-" : "");
184 		break;
185 	case OHCI_USB_OPER:
186 		/* this can happen after resuming a swsusp snapshot */
187 		ohci_dbg (ohci, "snapshot resume? reinit\n");
188 		status = -EBUSY;
189 		break;
190 	default:		/* RESET, we lost power */
191 		ohci_dbg (ohci, "lost power\n");
192 		status = -EBUSY;
193 	}
194 	if (status == -EBUSY) {
195 		if (!autostopped) {
196 			spin_unlock_irq (&ohci->lock);
197 			status = ohci_restart (ohci);
198 
199 			usb_root_hub_lost_power(hcd->self.root_hub);
200 
201 			spin_lock_irq (&ohci->lock);
202 		}
203 		return status;
204 	}
205 	if (status != -EINPROGRESS)
206 		return status;
207 	if (autostopped)
208 		goto skip_resume;
209 	spin_unlock_irq (&ohci->lock);
210 
211 	/* Some controllers (lucent erratum) need extra-long delays */
212 	msleep (20 /* usb 11.5.1.10 */ + 12 /* 32 msec counter */ + 1);
213 
214 	temp = ohci_readl (ohci, &ohci->regs->control);
215 	temp &= OHCI_CTRL_HCFS;
216 	if (temp != OHCI_USB_RESUME) {
217 		ohci_err (ohci, "controller won't resume\n");
218 		spin_lock_irq(&ohci->lock);
219 		return -EBUSY;
220 	}
221 
222 	/* disable old schedule state, reinit from scratch */
223 	ohci_writel (ohci, 0, &ohci->regs->ed_controlhead);
224 	ohci_writel (ohci, 0, &ohci->regs->ed_controlcurrent);
225 	ohci_writel (ohci, 0, &ohci->regs->ed_bulkhead);
226 	ohci_writel (ohci, 0, &ohci->regs->ed_bulkcurrent);
227 	ohci_writel (ohci, 0, &ohci->regs->ed_periodcurrent);
228 	ohci_writel (ohci, (u32) ohci->hcca_dma, &ohci->regs->hcca);
229 
230 	/* Sometimes PCI D3 suspend trashes frame timings ... */
231 	periodic_reinit (ohci);
232 
233 	/*
234 	 * The following code is executed with ohci->lock held and
235 	 * irqs disabled if and only if autostopped is true.  This
236 	 * will cause sparse to warn about a "context imbalance".
237 	 */
238 skip_resume:
239 	/* interrupts might have been disabled */
240 	ohci_writel (ohci, OHCI_INTR_INIT, &ohci->regs->intrenable);
241 	if (ohci->ed_rm_list)
242 		ohci_writel (ohci, OHCI_INTR_SF, &ohci->regs->intrenable);
243 
244 	/* Then re-enable operations */
245 	ohci_writel (ohci, OHCI_USB_OPER, &ohci->regs->control);
246 	(void) ohci_readl (ohci, &ohci->regs->control);
247 	if (!autostopped)
248 		msleep (3);
249 
250 	temp = ohci->hc_control;
251 	temp &= OHCI_CTRL_RWC;
252 	temp |= OHCI_CONTROL_INIT | OHCI_USB_OPER;
253 	ohci->hc_control = temp;
254 	ohci_writel (ohci, temp, &ohci->regs->control);
255 	(void) ohci_readl (ohci, &ohci->regs->control);
256 
257 	/* TRSMRCY */
258 	if (!autostopped) {
259 		msleep (10);
260 		spin_lock_irq (&ohci->lock);
261 	}
262 	/* now ohci->lock is always held and irqs are always disabled */
263 
264 	/* keep it alive for more than ~5x suspend + resume costs */
265 	ohci->next_statechange = jiffies + STATECHANGE_DELAY;
266 
267 	/* maybe turn schedules back on */
268 	enables = 0;
269 	temp = 0;
270 	if (!ohci->ed_rm_list) {
271 		if (ohci->ed_controltail) {
272 			ohci_writel (ohci,
273 					find_head (ohci->ed_controltail)->dma,
274 					&ohci->regs->ed_controlhead);
275 			enables |= OHCI_CTRL_CLE;
276 			temp |= OHCI_CLF;
277 		}
278 		if (ohci->ed_bulktail) {
279 			ohci_writel (ohci, find_head (ohci->ed_bulktail)->dma,
280 				&ohci->regs->ed_bulkhead);
281 			enables |= OHCI_CTRL_BLE;
282 			temp |= OHCI_BLF;
283 		}
284 	}
285 	if (hcd->self.bandwidth_isoc_reqs || hcd->self.bandwidth_int_reqs)
286 		enables |= OHCI_CTRL_PLE|OHCI_CTRL_IE;
287 	if (enables) {
288 		ohci_dbg (ohci, "restarting schedules ... %08x\n", enables);
289 		ohci->hc_control |= enables;
290 		ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
291 		if (temp)
292 			ohci_writel (ohci, temp, &ohci->regs->cmdstatus);
293 		(void) ohci_readl (ohci, &ohci->regs->control);
294 	}
295 
296 	ohci->rh_state = OHCI_RH_RUNNING;
297 	return 0;
298 }
299 
300 static int ohci_bus_suspend (struct usb_hcd *hcd)
301 {
302 	struct ohci_hcd		*ohci = hcd_to_ohci (hcd);
303 	int			rc;
304 
305 	spin_lock_irq (&ohci->lock);
306 
307 	if (unlikely(!HCD_HW_ACCESSIBLE(hcd)))
308 		rc = -ESHUTDOWN;
309 	else
310 		rc = ohci_rh_suspend (ohci, 0);
311 	spin_unlock_irq (&ohci->lock);
312 
313 	if (rc == 0)
314 		del_timer_sync(&ohci->io_watchdog);
315 	return rc;
316 }
317 
318 static int ohci_bus_resume (struct usb_hcd *hcd)
319 {
320 	struct ohci_hcd		*ohci = hcd_to_ohci (hcd);
321 	int			rc;
322 
323 	if (time_before (jiffies, ohci->next_statechange))
324 		msleep(5);
325 
326 	spin_lock_irq (&ohci->lock);
327 
328 	if (unlikely(!HCD_HW_ACCESSIBLE(hcd)))
329 		rc = -ESHUTDOWN;
330 	else
331 		rc = ohci_rh_resume (ohci);
332 	spin_unlock_irq (&ohci->lock);
333 
334 	/* poll until we know a device is connected or we autostop */
335 	if (rc == 0)
336 		usb_hcd_poll_rh_status(hcd);
337 	return rc;
338 }
339 
340 /* Carry out polling-, autostop-, and autoresume-related state changes */
341 static int ohci_root_hub_state_changes(struct ohci_hcd *ohci, int changed,
342 		int any_connected, int rhsc_status)
343 {
344 	int	poll_rh = 1;
345 	int	rhsc_enable;
346 
347 	/* Some broken controllers never turn off RHSC in the interrupt
348 	 * status register.  For their sake we won't re-enable RHSC
349 	 * interrupts if the interrupt bit is already active.
350 	 */
351 	rhsc_enable = ohci_readl(ohci, &ohci->regs->intrenable) &
352 			OHCI_INTR_RHSC;
353 
354 	switch (ohci->hc_control & OHCI_CTRL_HCFS) {
355 	case OHCI_USB_OPER:
356 		/* If no status changes are pending, enable RHSC interrupts. */
357 		if (!rhsc_enable && !rhsc_status && !changed) {
358 			rhsc_enable = OHCI_INTR_RHSC;
359 			ohci_writel(ohci, rhsc_enable, &ohci->regs->intrenable);
360 		}
361 
362 		/* Keep on polling until we know a device is connected
363 		 * and RHSC is enabled, or until we autostop.
364 		 */
365 		if (!ohci->autostop) {
366 			if (any_connected ||
367 					!device_may_wakeup(&ohci_to_hcd(ohci)
368 						->self.root_hub->dev)) {
369 				if (rhsc_enable)
370 					poll_rh = 0;
371 			} else {
372 				ohci->autostop = 1;
373 				ohci->next_statechange = jiffies + HZ;
374 			}
375 
376 		/* if no devices have been attached for one second, autostop */
377 		} else {
378 			if (changed || any_connected) {
379 				ohci->autostop = 0;
380 				ohci->next_statechange = jiffies +
381 						STATECHANGE_DELAY;
382 			} else if (time_after_eq(jiffies,
383 						ohci->next_statechange)
384 					&& !ohci->ed_rm_list
385 					&& !(ohci->hc_control &
386 						OHCI_SCHED_ENABLES)) {
387 				ohci_rh_suspend(ohci, 1);
388 				if (rhsc_enable)
389 					poll_rh = 0;
390 			}
391 		}
392 		break;
393 
394 	case OHCI_USB_SUSPEND:
395 	case OHCI_USB_RESUME:
396 		/* if there is a port change, autostart or ask to be resumed */
397 		if (changed) {
398 			if (ohci->autostop)
399 				ohci_rh_resume(ohci);
400 			else
401 				usb_hcd_resume_root_hub(ohci_to_hcd(ohci));
402 
403 		/* If remote wakeup is disabled, stop polling */
404 		} else if (!ohci->autostop &&
405 				!ohci_to_hcd(ohci)->self.root_hub->
406 					do_remote_wakeup) {
407 			poll_rh = 0;
408 
409 		} else {
410 			/* If no status changes are pending,
411 			 * enable RHSC interrupts
412 			 */
413 			if (!rhsc_enable && !rhsc_status) {
414 				rhsc_enable = OHCI_INTR_RHSC;
415 				ohci_writel(ohci, rhsc_enable,
416 						&ohci->regs->intrenable);
417 			}
418 			/* Keep polling until RHSC is enabled */
419 			if (rhsc_enable)
420 				poll_rh = 0;
421 		}
422 		break;
423 	}
424 	return poll_rh;
425 }
426 
427 #else	/* CONFIG_PM */
428 
429 static inline int ohci_rh_resume(struct ohci_hcd *ohci)
430 {
431 	return 0;
432 }
433 
434 /* Carry out polling-related state changes.
435  * autostop isn't used when CONFIG_PM is turned off.
436  */
437 static int ohci_root_hub_state_changes(struct ohci_hcd *ohci, int changed,
438 		int any_connected, int rhsc_status)
439 {
440 	/* If RHSC is enabled, don't poll */
441 	if (ohci_readl(ohci, &ohci->regs->intrenable) & OHCI_INTR_RHSC)
442 		return 0;
443 
444 	/* If status changes are pending, continue polling.
445 	 * Conversely, if no status changes are pending but the RHSC
446 	 * status bit was set, then RHSC may be broken so continue polling.
447 	 */
448 	if (changed || rhsc_status)
449 		return 1;
450 
451 	/* It's safe to re-enable RHSC interrupts */
452 	ohci_writel(ohci, OHCI_INTR_RHSC, &ohci->regs->intrenable);
453 	return 0;
454 }
455 
456 #endif	/* CONFIG_PM */
457 
458 /*-------------------------------------------------------------------------*/
459 
460 /* build "status change" packet (one or two bytes) from HC registers */
461 
462 int ohci_hub_status_data(struct usb_hcd *hcd, char *buf)
463 {
464 	struct ohci_hcd	*ohci = hcd_to_ohci (hcd);
465 	int		i, changed = 0, length = 1;
466 	int		any_connected = 0;
467 	int		rhsc_status;
468 	unsigned long	flags;
469 
470 	spin_lock_irqsave (&ohci->lock, flags);
471 	if (!HCD_HW_ACCESSIBLE(hcd))
472 		goto done;
473 
474 	/* undocumented erratum seen on at least rev D */
475 	if ((ohci->flags & OHCI_QUIRK_AMD756)
476 			&& (roothub_a (ohci) & RH_A_NDP) > MAX_ROOT_PORTS) {
477 		ohci_warn (ohci, "bogus NDP, rereads as NDP=%d\n",
478 			  ohci_readl (ohci, &ohci->regs->roothub.a) & RH_A_NDP);
479 		/* retry later; "should not happen" */
480 		goto done;
481 	}
482 
483 	/* init status */
484 	if (roothub_status (ohci) & (RH_HS_LPSC | RH_HS_OCIC))
485 		buf [0] = changed = 1;
486 	else
487 		buf [0] = 0;
488 	if (ohci->num_ports > 7) {
489 		buf [1] = 0;
490 		length++;
491 	}
492 
493 	/* Clear the RHSC status flag before reading the port statuses */
494 	ohci_writel(ohci, OHCI_INTR_RHSC, &ohci->regs->intrstatus);
495 	rhsc_status = ohci_readl(ohci, &ohci->regs->intrstatus) &
496 			OHCI_INTR_RHSC;
497 
498 	/* look at each port */
499 	for (i = 0; i < ohci->num_ports; i++) {
500 		u32	status = roothub_portstatus (ohci, i);
501 
502 		/* can't autostop if ports are connected */
503 		any_connected |= (status & RH_PS_CCS);
504 
505 		if (status & (RH_PS_CSC | RH_PS_PESC | RH_PS_PSSC
506 				| RH_PS_OCIC | RH_PS_PRSC)) {
507 			changed = 1;
508 			if (i < 7)
509 			    buf [0] |= 1 << (i + 1);
510 			else
511 			    buf [1] |= 1 << (i - 7);
512 		}
513 	}
514 
515 	if (ohci_root_hub_state_changes(ohci, changed,
516 			any_connected, rhsc_status))
517 		set_bit(HCD_FLAG_POLL_RH, &hcd->flags);
518 	else
519 		clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
520 
521 
522 done:
523 	spin_unlock_irqrestore (&ohci->lock, flags);
524 
525 	return changed ? length : 0;
526 }
527 EXPORT_SYMBOL_GPL(ohci_hub_status_data);
528 
529 /*-------------------------------------------------------------------------*/
530 
531 static void
532 ohci_hub_descriptor (
533 	struct ohci_hcd			*ohci,
534 	struct usb_hub_descriptor	*desc
535 ) {
536 	u32		rh = roothub_a (ohci);
537 	u16		temp;
538 
539 	desc->bDescriptorType = USB_DT_HUB;
540 	desc->bPwrOn2PwrGood = (rh & RH_A_POTPGT) >> 24;
541 	desc->bHubContrCurrent = 0;
542 
543 	desc->bNbrPorts = ohci->num_ports;
544 	temp = 1 + (ohci->num_ports / 8);
545 	desc->bDescLength = 7 + 2 * temp;
546 
547 	temp = HUB_CHAR_COMMON_LPSM | HUB_CHAR_COMMON_OCPM;
548 	if (rh & RH_A_NPS)		/* no power switching? */
549 		temp |= HUB_CHAR_NO_LPSM;
550 	if (rh & RH_A_PSM)		/* per-port power switching? */
551 		temp |= HUB_CHAR_INDV_PORT_LPSM;
552 	if (rh & RH_A_NOCP)		/* no overcurrent reporting? */
553 		temp |= HUB_CHAR_NO_OCPM;
554 	else if (rh & RH_A_OCPM)	/* per-port overcurrent reporting? */
555 		temp |= HUB_CHAR_INDV_PORT_OCPM;
556 	desc->wHubCharacteristics = cpu_to_le16(temp);
557 
558 	/* ports removable, and usb 1.0 legacy PortPwrCtrlMask */
559 	rh = roothub_b (ohci);
560 	memset(desc->u.hs.DeviceRemovable, 0xff,
561 			sizeof(desc->u.hs.DeviceRemovable));
562 	desc->u.hs.DeviceRemovable[0] = rh & RH_B_DR;
563 	if (ohci->num_ports > 7) {
564 		desc->u.hs.DeviceRemovable[1] = (rh & RH_B_DR) >> 8;
565 		desc->u.hs.DeviceRemovable[2] = 0xff;
566 	} else
567 		desc->u.hs.DeviceRemovable[1] = 0xff;
568 }
569 
570 /*-------------------------------------------------------------------------*/
571 
572 #ifdef	CONFIG_USB_OTG
573 
574 static int ohci_start_port_reset (struct usb_hcd *hcd, unsigned port)
575 {
576 	struct ohci_hcd	*ohci = hcd_to_ohci (hcd);
577 	u32			status;
578 
579 	if (!port)
580 		return -EINVAL;
581 	port--;
582 
583 	/* start port reset before HNP protocol times out */
584 	status = ohci_readl(ohci, &ohci->regs->roothub.portstatus [port]);
585 	if (!(status & RH_PS_CCS))
586 		return -ENODEV;
587 
588 	/* hub_wq will finish the reset later */
589 	ohci_writel(ohci, RH_PS_PRS, &ohci->regs->roothub.portstatus [port]);
590 	return 0;
591 }
592 
593 #else
594 
595 #define	ohci_start_port_reset		NULL
596 
597 #endif
598 
599 /*-------------------------------------------------------------------------*/
600 
601 
602 /* See usb 7.1.7.5:  root hubs must issue at least 50 msec reset signaling,
603  * not necessarily continuous ... to guard against resume signaling.
604  */
605 #define	PORT_RESET_MSEC		50
606 
607 /* this timer value might be vendor-specific ... */
608 #define	PORT_RESET_HW_MSEC	10
609 
610 /* wrap-aware logic morphed from <linux/jiffies.h> */
611 #define tick_before(t1,t2) ((s16)(((s16)(t1))-((s16)(t2))) < 0)
612 
613 /* called from some task, normally hub_wq */
614 static inline int root_port_reset (struct ohci_hcd *ohci, unsigned port)
615 {
616 	__hc32 __iomem *portstat = &ohci->regs->roothub.portstatus [port];
617 	u32	temp = 0;
618 	u16	now = ohci_readl(ohci, &ohci->regs->fmnumber);
619 	u16	reset_done = now + PORT_RESET_MSEC;
620 	int	limit_1 = DIV_ROUND_UP(PORT_RESET_MSEC, PORT_RESET_HW_MSEC);
621 
622 	/* build a "continuous enough" reset signal, with up to
623 	 * 3msec gap between pulses.  scheduler HZ==100 must work;
624 	 * this might need to be deadline-scheduled.
625 	 */
626 	do {
627 		int limit_2;
628 
629 		/* spin until any current reset finishes */
630 		limit_2 = PORT_RESET_HW_MSEC * 2;
631 		while (--limit_2 >= 0) {
632 			temp = ohci_readl (ohci, portstat);
633 			/* handle e.g. CardBus eject */
634 			if (temp == ~(u32)0)
635 				return -ESHUTDOWN;
636 			if (!(temp & RH_PS_PRS))
637 				break;
638 			udelay (500);
639 		}
640 
641 		/* timeout (a hardware error) has been observed when
642 		 * EHCI sets CF while this driver is resetting a port;
643 		 * presumably other disconnect paths might do it too.
644 		 */
645 		if (limit_2 < 0) {
646 			ohci_dbg(ohci,
647 				"port[%d] reset timeout, stat %08x\n",
648 				port, temp);
649 			break;
650 		}
651 
652 		if (!(temp & RH_PS_CCS))
653 			break;
654 		if (temp & RH_PS_PRSC)
655 			ohci_writel (ohci, RH_PS_PRSC, portstat);
656 
657 		/* start the next reset, sleep till it's probably done */
658 		ohci_writel (ohci, RH_PS_PRS, portstat);
659 		msleep(PORT_RESET_HW_MSEC);
660 		now = ohci_readl(ohci, &ohci->regs->fmnumber);
661 	} while (tick_before(now, reset_done) && --limit_1 >= 0);
662 
663 	/* caller synchronizes using PRSC ... and handles PRS
664 	 * still being set when this returns.
665 	 */
666 
667 	return 0;
668 }
669 
670 int ohci_hub_control(
671 	struct usb_hcd	*hcd,
672 	u16		typeReq,
673 	u16		wValue,
674 	u16		wIndex,
675 	char		*buf,
676 	u16		wLength
677 ) {
678 	struct ohci_hcd	*ohci = hcd_to_ohci (hcd);
679 	int		ports = ohci->num_ports;
680 	u32		temp;
681 	int		retval = 0;
682 
683 	if (unlikely(!HCD_HW_ACCESSIBLE(hcd)))
684 		return -ESHUTDOWN;
685 
686 	switch (typeReq) {
687 	case ClearHubFeature:
688 		switch (wValue) {
689 		case C_HUB_OVER_CURRENT:
690 			ohci_writel (ohci, RH_HS_OCIC,
691 					&ohci->regs->roothub.status);
692 		case C_HUB_LOCAL_POWER:
693 			break;
694 		default:
695 			goto error;
696 		}
697 		break;
698 	case ClearPortFeature:
699 		if (!wIndex || wIndex > ports)
700 			goto error;
701 		wIndex--;
702 
703 		switch (wValue) {
704 		case USB_PORT_FEAT_ENABLE:
705 			temp = RH_PS_CCS;
706 			break;
707 		case USB_PORT_FEAT_C_ENABLE:
708 			temp = RH_PS_PESC;
709 			break;
710 		case USB_PORT_FEAT_SUSPEND:
711 			temp = RH_PS_POCI;
712 			break;
713 		case USB_PORT_FEAT_C_SUSPEND:
714 			temp = RH_PS_PSSC;
715 			break;
716 		case USB_PORT_FEAT_POWER:
717 			temp = RH_PS_LSDA;
718 			break;
719 		case USB_PORT_FEAT_C_CONNECTION:
720 			temp = RH_PS_CSC;
721 			break;
722 		case USB_PORT_FEAT_C_OVER_CURRENT:
723 			temp = RH_PS_OCIC;
724 			break;
725 		case USB_PORT_FEAT_C_RESET:
726 			temp = RH_PS_PRSC;
727 			break;
728 		default:
729 			goto error;
730 		}
731 		ohci_writel (ohci, temp,
732 				&ohci->regs->roothub.portstatus [wIndex]);
733 		// ohci_readl (ohci, &ohci->regs->roothub.portstatus [wIndex]);
734 		break;
735 	case GetHubDescriptor:
736 		ohci_hub_descriptor (ohci, (struct usb_hub_descriptor *) buf);
737 		break;
738 	case GetHubStatus:
739 		temp = roothub_status (ohci) & ~(RH_HS_CRWE | RH_HS_DRWE);
740 		put_unaligned_le32(temp, buf);
741 		break;
742 	case GetPortStatus:
743 		if (!wIndex || wIndex > ports)
744 			goto error;
745 		wIndex--;
746 		temp = roothub_portstatus (ohci, wIndex);
747 		put_unaligned_le32(temp, buf);
748 
749 		if (*(u16*)(buf+2))	/* only if wPortChange is interesting */
750 			dbg_port(ohci, "GetStatus", wIndex, temp);
751 		break;
752 	case SetHubFeature:
753 		switch (wValue) {
754 		case C_HUB_OVER_CURRENT:
755 			// FIXME:  this can be cleared, yes?
756 		case C_HUB_LOCAL_POWER:
757 			break;
758 		default:
759 			goto error;
760 		}
761 		break;
762 	case SetPortFeature:
763 		if (!wIndex || wIndex > ports)
764 			goto error;
765 		wIndex--;
766 		switch (wValue) {
767 		case USB_PORT_FEAT_SUSPEND:
768 #ifdef	CONFIG_USB_OTG
769 			if (hcd->self.otg_port == (wIndex + 1)
770 					&& hcd->self.b_hnp_enable)
771 				ohci->start_hnp(ohci);
772 			else
773 #endif
774 			ohci_writel (ohci, RH_PS_PSS,
775 				&ohci->regs->roothub.portstatus [wIndex]);
776 			break;
777 		case USB_PORT_FEAT_POWER:
778 			ohci_writel (ohci, RH_PS_PPS,
779 				&ohci->regs->roothub.portstatus [wIndex]);
780 			break;
781 		case USB_PORT_FEAT_RESET:
782 			retval = root_port_reset (ohci, wIndex);
783 			break;
784 		default:
785 			goto error;
786 		}
787 		break;
788 
789 	default:
790 error:
791 		/* "protocol stall" on error */
792 		retval = -EPIPE;
793 	}
794 	return retval;
795 }
796 EXPORT_SYMBOL_GPL(ohci_hub_control);
797