xref: /linux/drivers/usb/host/ohci-hub.c (revision c4ee0af3fa0dc65f690fc908f02b8355f9576ea0)
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 dl_done_list (struct ohci_hcd *);
43 static void finish_unlinks (struct ohci_hcd *, u16);
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 	dl_done_list (ohci);
91 	finish_unlinks (ohci, ohci_frame_no(ohci));
92 
93 	/* maybe resume can wake root hub */
94 	if (ohci_to_hcd(ohci)->self.root_hub->do_remote_wakeup || autostop) {
95 		ohci->hc_control |= OHCI_CTRL_RWE;
96 	} else {
97 		ohci_writel(ohci, OHCI_INTR_RHSC | OHCI_INTR_RD,
98 				&ohci->regs->intrdisable);
99 		ohci->hc_control &= ~OHCI_CTRL_RWE;
100 	}
101 
102 	/* Suspend hub ... this is the "global (to this bus) suspend" mode,
103 	 * which doesn't imply ports will first be individually suspended.
104 	 */
105 	ohci->hc_control &= ~OHCI_CTRL_HCFS;
106 	ohci->hc_control |= OHCI_USB_SUSPEND;
107 	ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
108 	(void) ohci_readl (ohci, &ohci->regs->control);
109 
110 	/* no resumes until devices finish suspending */
111 	if (!autostop) {
112 		ohci->next_statechange = jiffies + msecs_to_jiffies (5);
113 		ohci->autostop = 0;
114 		ohci->rh_state = OHCI_RH_SUSPENDED;
115 	}
116 
117 done:
118 	return status;
119 }
120 
121 static inline struct ed *find_head (struct ed *ed)
122 {
123 	/* for bulk and control lists */
124 	while (ed->ed_prev)
125 		ed = ed->ed_prev;
126 	return ed;
127 }
128 
129 /* caller has locked the root hub */
130 static int ohci_rh_resume (struct ohci_hcd *ohci)
131 __releases(ohci->lock)
132 __acquires(ohci->lock)
133 {
134 	struct usb_hcd		*hcd = ohci_to_hcd (ohci);
135 	u32			temp, enables;
136 	int			status = -EINPROGRESS;
137 	int			autostopped = ohci->autostop;
138 
139 	ohci->autostop = 0;
140 	ohci->hc_control = ohci_readl (ohci, &ohci->regs->control);
141 
142 	if (ohci->hc_control & (OHCI_CTRL_IR | OHCI_SCHED_ENABLES)) {
143 		/* this can happen after resuming a swsusp snapshot */
144 		if (ohci->rh_state != OHCI_RH_RUNNING) {
145 			ohci_dbg (ohci, "BIOS/SMM active, control %03x\n",
146 					ohci->hc_control);
147 			status = -EBUSY;
148 		/* this happens when pmcore resumes HC then root */
149 		} else {
150 			ohci_dbg (ohci, "duplicate resume\n");
151 			status = 0;
152 		}
153 	} else switch (ohci->hc_control & OHCI_CTRL_HCFS) {
154 	case OHCI_USB_SUSPEND:
155 		ohci->hc_control &= ~(OHCI_CTRL_HCFS|OHCI_SCHED_ENABLES);
156 		ohci->hc_control |= OHCI_USB_RESUME;
157 		ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
158 		(void) ohci_readl (ohci, &ohci->regs->control);
159 		ohci_dbg (ohci, "%s root hub\n",
160 				autostopped ? "auto-start" : "resume");
161 		break;
162 	case OHCI_USB_RESUME:
163 		/* HCFS changes sometime after INTR_RD */
164 		ohci_dbg(ohci, "%swakeup root hub\n",
165 				autostopped ? "auto-" : "");
166 		break;
167 	case OHCI_USB_OPER:
168 		/* this can happen after resuming a swsusp snapshot */
169 		ohci_dbg (ohci, "snapshot resume? reinit\n");
170 		status = -EBUSY;
171 		break;
172 	default:		/* RESET, we lost power */
173 		ohci_dbg (ohci, "lost power\n");
174 		status = -EBUSY;
175 	}
176 	if (status == -EBUSY) {
177 		if (!autostopped) {
178 			spin_unlock_irq (&ohci->lock);
179 			status = ohci_restart (ohci);
180 
181 			usb_root_hub_lost_power(hcd->self.root_hub);
182 
183 			spin_lock_irq (&ohci->lock);
184 		}
185 		return status;
186 	}
187 	if (status != -EINPROGRESS)
188 		return status;
189 	if (autostopped)
190 		goto skip_resume;
191 	spin_unlock_irq (&ohci->lock);
192 
193 	/* Some controllers (lucent erratum) need extra-long delays */
194 	msleep (20 /* usb 11.5.1.10 */ + 12 /* 32 msec counter */ + 1);
195 
196 	temp = ohci_readl (ohci, &ohci->regs->control);
197 	temp &= OHCI_CTRL_HCFS;
198 	if (temp != OHCI_USB_RESUME) {
199 		ohci_err (ohci, "controller won't resume\n");
200 		spin_lock_irq(&ohci->lock);
201 		return -EBUSY;
202 	}
203 
204 	/* disable old schedule state, reinit from scratch */
205 	ohci_writel (ohci, 0, &ohci->regs->ed_controlhead);
206 	ohci_writel (ohci, 0, &ohci->regs->ed_controlcurrent);
207 	ohci_writel (ohci, 0, &ohci->regs->ed_bulkhead);
208 	ohci_writel (ohci, 0, &ohci->regs->ed_bulkcurrent);
209 	ohci_writel (ohci, 0, &ohci->regs->ed_periodcurrent);
210 	ohci_writel (ohci, (u32) ohci->hcca_dma, &ohci->regs->hcca);
211 
212 	/* Sometimes PCI D3 suspend trashes frame timings ... */
213 	periodic_reinit (ohci);
214 
215 	/*
216 	 * The following code is executed with ohci->lock held and
217 	 * irqs disabled if and only if autostopped is true.  This
218 	 * will cause sparse to warn about a "context imbalance".
219 	 */
220 skip_resume:
221 	/* interrupts might have been disabled */
222 	ohci_writel (ohci, OHCI_INTR_INIT, &ohci->regs->intrenable);
223 	if (ohci->ed_rm_list)
224 		ohci_writel (ohci, OHCI_INTR_SF, &ohci->regs->intrenable);
225 
226 	/* Then re-enable operations */
227 	ohci_writel (ohci, OHCI_USB_OPER, &ohci->regs->control);
228 	(void) ohci_readl (ohci, &ohci->regs->control);
229 	if (!autostopped)
230 		msleep (3);
231 
232 	temp = ohci->hc_control;
233 	temp &= OHCI_CTRL_RWC;
234 	temp |= OHCI_CONTROL_INIT | OHCI_USB_OPER;
235 	ohci->hc_control = temp;
236 	ohci_writel (ohci, temp, &ohci->regs->control);
237 	(void) ohci_readl (ohci, &ohci->regs->control);
238 
239 	/* TRSMRCY */
240 	if (!autostopped) {
241 		msleep (10);
242 		spin_lock_irq (&ohci->lock);
243 	}
244 	/* now ohci->lock is always held and irqs are always disabled */
245 
246 	/* keep it alive for more than ~5x suspend + resume costs */
247 	ohci->next_statechange = jiffies + STATECHANGE_DELAY;
248 
249 	/* maybe turn schedules back on */
250 	enables = 0;
251 	temp = 0;
252 	if (!ohci->ed_rm_list) {
253 		if (ohci->ed_controltail) {
254 			ohci_writel (ohci,
255 					find_head (ohci->ed_controltail)->dma,
256 					&ohci->regs->ed_controlhead);
257 			enables |= OHCI_CTRL_CLE;
258 			temp |= OHCI_CLF;
259 		}
260 		if (ohci->ed_bulktail) {
261 			ohci_writel (ohci, find_head (ohci->ed_bulktail)->dma,
262 				&ohci->regs->ed_bulkhead);
263 			enables |= OHCI_CTRL_BLE;
264 			temp |= OHCI_BLF;
265 		}
266 	}
267 	if (hcd->self.bandwidth_isoc_reqs || hcd->self.bandwidth_int_reqs)
268 		enables |= OHCI_CTRL_PLE|OHCI_CTRL_IE;
269 	if (enables) {
270 		ohci_dbg (ohci, "restarting schedules ... %08x\n", enables);
271 		ohci->hc_control |= enables;
272 		ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
273 		if (temp)
274 			ohci_writel (ohci, temp, &ohci->regs->cmdstatus);
275 		(void) ohci_readl (ohci, &ohci->regs->control);
276 	}
277 
278 	ohci->rh_state = OHCI_RH_RUNNING;
279 	return 0;
280 }
281 
282 static int ohci_bus_suspend (struct usb_hcd *hcd)
283 {
284 	struct ohci_hcd		*ohci = hcd_to_ohci (hcd);
285 	int			rc;
286 
287 	spin_lock_irq (&ohci->lock);
288 
289 	if (unlikely(!HCD_HW_ACCESSIBLE(hcd)))
290 		rc = -ESHUTDOWN;
291 	else
292 		rc = ohci_rh_suspend (ohci, 0);
293 	spin_unlock_irq (&ohci->lock);
294 	return rc;
295 }
296 
297 static int ohci_bus_resume (struct usb_hcd *hcd)
298 {
299 	struct ohci_hcd		*ohci = hcd_to_ohci (hcd);
300 	int			rc;
301 
302 	if (time_before (jiffies, ohci->next_statechange))
303 		msleep(5);
304 
305 	spin_lock_irq (&ohci->lock);
306 
307 	if (unlikely(!HCD_HW_ACCESSIBLE(hcd)))
308 		rc = -ESHUTDOWN;
309 	else
310 		rc = ohci_rh_resume (ohci);
311 	spin_unlock_irq (&ohci->lock);
312 
313 	/* poll until we know a device is connected or we autostop */
314 	if (rc == 0)
315 		usb_hcd_poll_rh_status(hcd);
316 	return rc;
317 }
318 
319 /* Carry out polling-, autostop-, and autoresume-related state changes */
320 static int ohci_root_hub_state_changes(struct ohci_hcd *ohci, int changed,
321 		int any_connected, int rhsc_status)
322 {
323 	int	poll_rh = 1;
324 	int	rhsc_enable;
325 
326 	/* Some broken controllers never turn off RHSC in the interrupt
327 	 * status register.  For their sake we won't re-enable RHSC
328 	 * interrupts if the interrupt bit is already active.
329 	 */
330 	rhsc_enable = ohci_readl(ohci, &ohci->regs->intrenable) &
331 			OHCI_INTR_RHSC;
332 
333 	switch (ohci->hc_control & OHCI_CTRL_HCFS) {
334 	case OHCI_USB_OPER:
335 		/* If no status changes are pending, enable RHSC interrupts. */
336 		if (!rhsc_enable && !rhsc_status && !changed) {
337 			rhsc_enable = OHCI_INTR_RHSC;
338 			ohci_writel(ohci, rhsc_enable, &ohci->regs->intrenable);
339 		}
340 
341 		/* Keep on polling until we know a device is connected
342 		 * and RHSC is enabled, or until we autostop.
343 		 */
344 		if (!ohci->autostop) {
345 			if (any_connected ||
346 					!device_may_wakeup(&ohci_to_hcd(ohci)
347 						->self.root_hub->dev)) {
348 				if (rhsc_enable)
349 					poll_rh = 0;
350 			} else {
351 				ohci->autostop = 1;
352 				ohci->next_statechange = jiffies + HZ;
353 			}
354 
355 		/* if no devices have been attached for one second, autostop */
356 		} else {
357 			if (changed || any_connected) {
358 				ohci->autostop = 0;
359 				ohci->next_statechange = jiffies +
360 						STATECHANGE_DELAY;
361 			} else if (time_after_eq(jiffies,
362 						ohci->next_statechange)
363 					&& !ohci->ed_rm_list
364 					&& !(ohci->hc_control &
365 						OHCI_SCHED_ENABLES)) {
366 				ohci_rh_suspend(ohci, 1);
367 				if (rhsc_enable)
368 					poll_rh = 0;
369 			}
370 		}
371 		break;
372 
373 	case OHCI_USB_SUSPEND:
374 	case OHCI_USB_RESUME:
375 		/* if there is a port change, autostart or ask to be resumed */
376 		if (changed) {
377 			if (ohci->autostop)
378 				ohci_rh_resume(ohci);
379 			else
380 				usb_hcd_resume_root_hub(ohci_to_hcd(ohci));
381 
382 		/* If remote wakeup is disabled, stop polling */
383 		} else if (!ohci->autostop &&
384 				!ohci_to_hcd(ohci)->self.root_hub->
385 					do_remote_wakeup) {
386 			poll_rh = 0;
387 
388 		} else {
389 			/* If no status changes are pending,
390 			 * enable RHSC interrupts
391 			 */
392 			if (!rhsc_enable && !rhsc_status) {
393 				rhsc_enable = OHCI_INTR_RHSC;
394 				ohci_writel(ohci, rhsc_enable,
395 						&ohci->regs->intrenable);
396 			}
397 			/* Keep polling until RHSC is enabled */
398 			if (rhsc_enable)
399 				poll_rh = 0;
400 		}
401 		break;
402 	}
403 	return poll_rh;
404 }
405 
406 #else	/* CONFIG_PM */
407 
408 static inline int ohci_rh_resume(struct ohci_hcd *ohci)
409 {
410 	return 0;
411 }
412 
413 /* Carry out polling-related state changes.
414  * autostop isn't used when CONFIG_PM is turned off.
415  */
416 static int ohci_root_hub_state_changes(struct ohci_hcd *ohci, int changed,
417 		int any_connected, int rhsc_status)
418 {
419 	/* If RHSC is enabled, don't poll */
420 	if (ohci_readl(ohci, &ohci->regs->intrenable) & OHCI_INTR_RHSC)
421 		return 0;
422 
423 	/* If status changes are pending, continue polling.
424 	 * Conversely, if no status changes are pending but the RHSC
425 	 * status bit was set, then RHSC may be broken so continue polling.
426 	 */
427 	if (changed || rhsc_status)
428 		return 1;
429 
430 	/* It's safe to re-enable RHSC interrupts */
431 	ohci_writel(ohci, OHCI_INTR_RHSC, &ohci->regs->intrenable);
432 	return 0;
433 }
434 
435 #endif	/* CONFIG_PM */
436 
437 /*-------------------------------------------------------------------------*/
438 
439 /* build "status change" packet (one or two bytes) from HC registers */
440 
441 static int
442 ohci_hub_status_data (struct usb_hcd *hcd, char *buf)
443 {
444 	struct ohci_hcd	*ohci = hcd_to_ohci (hcd);
445 	int		i, changed = 0, length = 1;
446 	int		any_connected = 0;
447 	int		rhsc_status;
448 	unsigned long	flags;
449 
450 	spin_lock_irqsave (&ohci->lock, flags);
451 	if (!HCD_HW_ACCESSIBLE(hcd))
452 		goto done;
453 
454 	/* undocumented erratum seen on at least rev D */
455 	if ((ohci->flags & OHCI_QUIRK_AMD756)
456 			&& (roothub_a (ohci) & RH_A_NDP) > MAX_ROOT_PORTS) {
457 		ohci_warn (ohci, "bogus NDP, rereads as NDP=%d\n",
458 			  ohci_readl (ohci, &ohci->regs->roothub.a) & RH_A_NDP);
459 		/* retry later; "should not happen" */
460 		goto done;
461 	}
462 
463 	/* init status */
464 	if (roothub_status (ohci) & (RH_HS_LPSC | RH_HS_OCIC))
465 		buf [0] = changed = 1;
466 	else
467 		buf [0] = 0;
468 	if (ohci->num_ports > 7) {
469 		buf [1] = 0;
470 		length++;
471 	}
472 
473 	/* Clear the RHSC status flag before reading the port statuses */
474 	ohci_writel(ohci, OHCI_INTR_RHSC, &ohci->regs->intrstatus);
475 	rhsc_status = ohci_readl(ohci, &ohci->regs->intrstatus) &
476 			OHCI_INTR_RHSC;
477 
478 	/* look at each port */
479 	for (i = 0; i < ohci->num_ports; i++) {
480 		u32	status = roothub_portstatus (ohci, i);
481 
482 		/* can't autostop if ports are connected */
483 		any_connected |= (status & RH_PS_CCS);
484 
485 		if (status & (RH_PS_CSC | RH_PS_PESC | RH_PS_PSSC
486 				| RH_PS_OCIC | RH_PS_PRSC)) {
487 			changed = 1;
488 			if (i < 7)
489 			    buf [0] |= 1 << (i + 1);
490 			else
491 			    buf [1] |= 1 << (i - 7);
492 		}
493 	}
494 
495 	if (ohci_root_hub_state_changes(ohci, changed,
496 			any_connected, rhsc_status))
497 		set_bit(HCD_FLAG_POLL_RH, &hcd->flags);
498 	else
499 		clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
500 
501 
502 done:
503 	spin_unlock_irqrestore (&ohci->lock, flags);
504 
505 	return changed ? length : 0;
506 }
507 
508 /*-------------------------------------------------------------------------*/
509 
510 static void
511 ohci_hub_descriptor (
512 	struct ohci_hcd			*ohci,
513 	struct usb_hub_descriptor	*desc
514 ) {
515 	u32		rh = roothub_a (ohci);
516 	u16		temp;
517 
518 	desc->bDescriptorType = 0x29;
519 	desc->bPwrOn2PwrGood = (rh & RH_A_POTPGT) >> 24;
520 	desc->bHubContrCurrent = 0;
521 
522 	desc->bNbrPorts = ohci->num_ports;
523 	temp = 1 + (ohci->num_ports / 8);
524 	desc->bDescLength = 7 + 2 * temp;
525 
526 	temp = 0;
527 	if (rh & RH_A_NPS)		/* no power switching? */
528 	    temp |= 0x0002;
529 	if (rh & RH_A_PSM)		/* per-port power switching? */
530 	    temp |= 0x0001;
531 	if (rh & RH_A_NOCP)		/* no overcurrent reporting? */
532 	    temp |= 0x0010;
533 	else if (rh & RH_A_OCPM)	/* per-port overcurrent reporting? */
534 	    temp |= 0x0008;
535 	desc->wHubCharacteristics = cpu_to_le16(temp);
536 
537 	/* ports removable, and usb 1.0 legacy PortPwrCtrlMask */
538 	rh = roothub_b (ohci);
539 	memset(desc->u.hs.DeviceRemovable, 0xff,
540 			sizeof(desc->u.hs.DeviceRemovable));
541 	desc->u.hs.DeviceRemovable[0] = rh & RH_B_DR;
542 	if (ohci->num_ports > 7) {
543 		desc->u.hs.DeviceRemovable[1] = (rh & RH_B_DR) >> 8;
544 		desc->u.hs.DeviceRemovable[2] = 0xff;
545 	} else
546 		desc->u.hs.DeviceRemovable[1] = 0xff;
547 }
548 
549 /*-------------------------------------------------------------------------*/
550 
551 #ifdef	CONFIG_USB_OTG
552 
553 static int ohci_start_port_reset (struct usb_hcd *hcd, unsigned port)
554 {
555 	struct ohci_hcd	*ohci = hcd_to_ohci (hcd);
556 	u32			status;
557 
558 	if (!port)
559 		return -EINVAL;
560 	port--;
561 
562 	/* start port reset before HNP protocol times out */
563 	status = ohci_readl(ohci, &ohci->regs->roothub.portstatus [port]);
564 	if (!(status & RH_PS_CCS))
565 		return -ENODEV;
566 
567 	/* khubd will finish the reset later */
568 	ohci_writel(ohci, RH_PS_PRS, &ohci->regs->roothub.portstatus [port]);
569 	return 0;
570 }
571 
572 #else
573 
574 #define	ohci_start_port_reset		NULL
575 
576 #endif
577 
578 /*-------------------------------------------------------------------------*/
579 
580 
581 /* See usb 7.1.7.5:  root hubs must issue at least 50 msec reset signaling,
582  * not necessarily continuous ... to guard against resume signaling.
583  */
584 #define	PORT_RESET_MSEC		50
585 
586 /* this timer value might be vendor-specific ... */
587 #define	PORT_RESET_HW_MSEC	10
588 
589 /* wrap-aware logic morphed from <linux/jiffies.h> */
590 #define tick_before(t1,t2) ((s16)(((s16)(t1))-((s16)(t2))) < 0)
591 
592 /* called from some task, normally khubd */
593 static inline int root_port_reset (struct ohci_hcd *ohci, unsigned port)
594 {
595 	__hc32 __iomem *portstat = &ohci->regs->roothub.portstatus [port];
596 	u32	temp = 0;
597 	u16	now = ohci_readl(ohci, &ohci->regs->fmnumber);
598 	u16	reset_done = now + PORT_RESET_MSEC;
599 	int	limit_1 = DIV_ROUND_UP(PORT_RESET_MSEC, PORT_RESET_HW_MSEC);
600 
601 	/* build a "continuous enough" reset signal, with up to
602 	 * 3msec gap between pulses.  scheduler HZ==100 must work;
603 	 * this might need to be deadline-scheduled.
604 	 */
605 	do {
606 		int limit_2;
607 
608 		/* spin until any current reset finishes */
609 		limit_2 = PORT_RESET_HW_MSEC * 2;
610 		while (--limit_2 >= 0) {
611 			temp = ohci_readl (ohci, portstat);
612 			/* handle e.g. CardBus eject */
613 			if (temp == ~(u32)0)
614 				return -ESHUTDOWN;
615 			if (!(temp & RH_PS_PRS))
616 				break;
617 			udelay (500);
618 		}
619 
620 		/* timeout (a hardware error) has been observed when
621 		 * EHCI sets CF while this driver is resetting a port;
622 		 * presumably other disconnect paths might do it too.
623 		 */
624 		if (limit_2 < 0) {
625 			ohci_dbg(ohci,
626 				"port[%d] reset timeout, stat %08x\n",
627 				port, temp);
628 			break;
629 		}
630 
631 		if (!(temp & RH_PS_CCS))
632 			break;
633 		if (temp & RH_PS_PRSC)
634 			ohci_writel (ohci, RH_PS_PRSC, portstat);
635 
636 		/* start the next reset, sleep till it's probably done */
637 		ohci_writel (ohci, RH_PS_PRS, portstat);
638 		msleep(PORT_RESET_HW_MSEC);
639 		now = ohci_readl(ohci, &ohci->regs->fmnumber);
640 	} while (tick_before(now, reset_done) && --limit_1 >= 0);
641 
642 	/* caller synchronizes using PRSC ... and handles PRS
643 	 * still being set when this returns.
644 	 */
645 
646 	return 0;
647 }
648 
649 static int ohci_hub_control (
650 	struct usb_hcd	*hcd,
651 	u16		typeReq,
652 	u16		wValue,
653 	u16		wIndex,
654 	char		*buf,
655 	u16		wLength
656 ) {
657 	struct ohci_hcd	*ohci = hcd_to_ohci (hcd);
658 	int		ports = ohci->num_ports;
659 	u32		temp;
660 	int		retval = 0;
661 
662 	if (unlikely(!HCD_HW_ACCESSIBLE(hcd)))
663 		return -ESHUTDOWN;
664 
665 	switch (typeReq) {
666 	case ClearHubFeature:
667 		switch (wValue) {
668 		case C_HUB_OVER_CURRENT:
669 			ohci_writel (ohci, RH_HS_OCIC,
670 					&ohci->regs->roothub.status);
671 		case C_HUB_LOCAL_POWER:
672 			break;
673 		default:
674 			goto error;
675 		}
676 		break;
677 	case ClearPortFeature:
678 		if (!wIndex || wIndex > ports)
679 			goto error;
680 		wIndex--;
681 
682 		switch (wValue) {
683 		case USB_PORT_FEAT_ENABLE:
684 			temp = RH_PS_CCS;
685 			break;
686 		case USB_PORT_FEAT_C_ENABLE:
687 			temp = RH_PS_PESC;
688 			break;
689 		case USB_PORT_FEAT_SUSPEND:
690 			temp = RH_PS_POCI;
691 			break;
692 		case USB_PORT_FEAT_C_SUSPEND:
693 			temp = RH_PS_PSSC;
694 			break;
695 		case USB_PORT_FEAT_POWER:
696 			temp = RH_PS_LSDA;
697 			break;
698 		case USB_PORT_FEAT_C_CONNECTION:
699 			temp = RH_PS_CSC;
700 			break;
701 		case USB_PORT_FEAT_C_OVER_CURRENT:
702 			temp = RH_PS_OCIC;
703 			break;
704 		case USB_PORT_FEAT_C_RESET:
705 			temp = RH_PS_PRSC;
706 			break;
707 		default:
708 			goto error;
709 		}
710 		ohci_writel (ohci, temp,
711 				&ohci->regs->roothub.portstatus [wIndex]);
712 		// ohci_readl (ohci, &ohci->regs->roothub.portstatus [wIndex]);
713 		break;
714 	case GetHubDescriptor:
715 		ohci_hub_descriptor (ohci, (struct usb_hub_descriptor *) buf);
716 		break;
717 	case GetHubStatus:
718 		temp = roothub_status (ohci) & ~(RH_HS_CRWE | RH_HS_DRWE);
719 		put_unaligned_le32(temp, buf);
720 		break;
721 	case GetPortStatus:
722 		if (!wIndex || wIndex > ports)
723 			goto error;
724 		wIndex--;
725 		temp = roothub_portstatus (ohci, wIndex);
726 		put_unaligned_le32(temp, buf);
727 
728 #ifndef	OHCI_VERBOSE_DEBUG
729 	if (*(u16*)(buf+2))	/* only if wPortChange is interesting */
730 #endif
731 		dbg_port (ohci, "GetStatus", wIndex, temp);
732 		break;
733 	case SetHubFeature:
734 		switch (wValue) {
735 		case C_HUB_OVER_CURRENT:
736 			// FIXME:  this can be cleared, yes?
737 		case C_HUB_LOCAL_POWER:
738 			break;
739 		default:
740 			goto error;
741 		}
742 		break;
743 	case SetPortFeature:
744 		if (!wIndex || wIndex > ports)
745 			goto error;
746 		wIndex--;
747 		switch (wValue) {
748 		case USB_PORT_FEAT_SUSPEND:
749 #ifdef	CONFIG_USB_OTG
750 			if (hcd->self.otg_port == (wIndex + 1)
751 					&& hcd->self.b_hnp_enable)
752 				ohci->start_hnp(ohci);
753 			else
754 #endif
755 			ohci_writel (ohci, RH_PS_PSS,
756 				&ohci->regs->roothub.portstatus [wIndex]);
757 			break;
758 		case USB_PORT_FEAT_POWER:
759 			ohci_writel (ohci, RH_PS_PPS,
760 				&ohci->regs->roothub.portstatus [wIndex]);
761 			break;
762 		case USB_PORT_FEAT_RESET:
763 			retval = root_port_reset (ohci, wIndex);
764 			break;
765 		default:
766 			goto error;
767 		}
768 		break;
769 
770 	default:
771 error:
772 		/* "protocol stall" on error */
773 		retval = -EPIPE;
774 	}
775 	return retval;
776 }
777 
778