xref: /openbmc/linux/drivers/usb/host/ohci-hub.c (revision 63705da3)
1 // SPDX-License-Identifier: GPL-1.0+
2 /*
3  * OHCI HCD (Host Controller Driver) for USB.
4  *
5  * (C) Copyright 1999 Roman Weissgaerber <weissg@vienna.at>
6  * (C) Copyright 2000-2004 David Brownell <dbrownell@users.sourceforge.net>
7  *
8  * This file is licenced under GPL
9  */
10 
11 /*-------------------------------------------------------------------------*/
12 
13 /*
14  * OHCI Root Hub ... the nonsharable stuff
15  */
16 
17 #define dbg_port(hc,label,num,value) \
18 	ohci_dbg (hc, \
19 		"%s roothub.portstatus [%d] " \
20 		"= 0x%08x%s%s%s%s%s%s%s%s%s%s%s%s\n", \
21 		label, num, value, \
22 		(value & RH_PS_PRSC) ? " PRSC" : "", \
23 		(value & RH_PS_OCIC) ? " OCIC" : "", \
24 		(value & RH_PS_PSSC) ? " PSSC" : "", \
25 		(value & RH_PS_PESC) ? " PESC" : "", \
26 		(value & RH_PS_CSC) ? " CSC" : "", \
27 		\
28 		(value & RH_PS_LSDA) ? " LSDA" : "", \
29 		(value & RH_PS_PPS) ? " PPS" : "", \
30 		(value & RH_PS_PRS) ? " PRS" : "", \
31 		(value & RH_PS_POCI) ? " POCI" : "", \
32 		(value & RH_PS_PSS) ? " PSS" : "", \
33 		\
34 		(value & RH_PS_PES) ? " PES" : "", \
35 		(value & RH_PS_CCS) ? " CCS" : "" \
36 		);
37 
38 /*-------------------------------------------------------------------------*/
39 
40 #define OHCI_SCHED_ENABLES \
41 	(OHCI_CTRL_CLE|OHCI_CTRL_BLE|OHCI_CTRL_PLE|OHCI_CTRL_IE)
42 
43 static void update_done_list(struct ohci_hcd *);
44 static void ohci_work(struct ohci_hcd *);
45 
46 #ifdef	CONFIG_PM
47 static int ohci_rh_suspend (struct ohci_hcd *ohci, int autostop)
48 __releases(ohci->lock)
49 __acquires(ohci->lock)
50 {
51 	int			status = 0;
52 
53 	ohci->hc_control = ohci_readl (ohci, &ohci->regs->control);
54 	switch (ohci->hc_control & OHCI_CTRL_HCFS) {
55 	case OHCI_USB_RESUME:
56 		ohci_dbg (ohci, "resume/suspend?\n");
57 		ohci->hc_control &= ~OHCI_CTRL_HCFS;
58 		ohci->hc_control |= OHCI_USB_RESET;
59 		ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
60 		(void) ohci_readl (ohci, &ohci->regs->control);
61 		fallthrough;
62 	case OHCI_USB_RESET:
63 		status = -EBUSY;
64 		ohci_dbg (ohci, "needs reinit!\n");
65 		goto done;
66 	case OHCI_USB_SUSPEND:
67 		if (!ohci->autostop) {
68 			ohci_dbg (ohci, "already suspended\n");
69 			goto done;
70 		}
71 	}
72 	ohci_dbg (ohci, "%s root hub\n",
73 			autostop ? "auto-stop" : "suspend");
74 
75 	/* First stop any processing */
76 	if (!autostop && (ohci->hc_control & OHCI_SCHED_ENABLES)) {
77 		ohci->hc_control &= ~OHCI_SCHED_ENABLES;
78 		ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
79 		ohci->hc_control = ohci_readl (ohci, &ohci->regs->control);
80 		ohci_writel (ohci, OHCI_INTR_SF, &ohci->regs->intrstatus);
81 
82 		/* sched disables take effect on the next frame,
83 		 * then the last WDH could take 6+ msec
84 		 */
85 		ohci_dbg (ohci, "stopping schedules ...\n");
86 		ohci->autostop = 0;
87 		spin_unlock_irq (&ohci->lock);
88 		msleep (8);
89 		spin_lock_irq (&ohci->lock);
90 	}
91 	update_done_list(ohci);
92 	ohci_work(ohci);
93 
94 	/* All ED unlinks should be finished, no need for SOF interrupts */
95 	ohci_writel(ohci, OHCI_INTR_SF, &ohci->regs->intrdisable);
96 
97 	/*
98 	 * Some controllers don't handle "global" suspend properly if
99 	 * there are unsuspended ports.  For these controllers, put all
100 	 * the enabled ports into suspend before suspending the root hub.
101 	 */
102 	if (ohci->flags & OHCI_QUIRK_GLOBAL_SUSPEND) {
103 		__hc32 __iomem	*portstat = ohci->regs->roothub.portstatus;
104 		int		i;
105 		unsigned	temp;
106 
107 		for (i = 0; i < ohci->num_ports; (++i, ++portstat)) {
108 			temp = ohci_readl(ohci, portstat);
109 			if ((temp & (RH_PS_PES | RH_PS_PSS)) ==
110 					RH_PS_PES)
111 				ohci_writel(ohci, RH_PS_PSS, portstat);
112 		}
113 	}
114 
115 	/* maybe resume can wake root hub */
116 	if (ohci_to_hcd(ohci)->self.root_hub->do_remote_wakeup || autostop) {
117 		ohci->hc_control |= OHCI_CTRL_RWE;
118 	} else {
119 		ohci_writel(ohci, OHCI_INTR_RHSC | OHCI_INTR_RD,
120 				&ohci->regs->intrdisable);
121 		ohci->hc_control &= ~OHCI_CTRL_RWE;
122 	}
123 
124 	/* Suspend hub ... this is the "global (to this bus) suspend" mode,
125 	 * which doesn't imply ports will first be individually suspended.
126 	 */
127 	ohci->hc_control &= ~OHCI_CTRL_HCFS;
128 	ohci->hc_control |= OHCI_USB_SUSPEND;
129 	ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
130 	(void) ohci_readl (ohci, &ohci->regs->control);
131 
132 	/* no resumes until devices finish suspending */
133 	if (!autostop) {
134 		ohci->next_statechange = jiffies + msecs_to_jiffies (5);
135 		ohci->autostop = 0;
136 		ohci->rh_state = OHCI_RH_SUSPENDED;
137 	}
138 
139 done:
140 	return status;
141 }
142 
143 static inline struct ed *find_head (struct ed *ed)
144 {
145 	/* for bulk and control lists */
146 	while (ed->ed_prev)
147 		ed = ed->ed_prev;
148 	return ed;
149 }
150 
151 /* caller has locked the root hub */
152 static int ohci_rh_resume (struct ohci_hcd *ohci)
153 __releases(ohci->lock)
154 __acquires(ohci->lock)
155 {
156 	struct usb_hcd		*hcd = ohci_to_hcd (ohci);
157 	u32			temp, enables;
158 	int			status = -EINPROGRESS;
159 	int			autostopped = ohci->autostop;
160 
161 	ohci->autostop = 0;
162 	ohci->hc_control = ohci_readl (ohci, &ohci->regs->control);
163 
164 	if (ohci->hc_control & (OHCI_CTRL_IR | OHCI_SCHED_ENABLES)) {
165 		/* this can happen after resuming a swsusp snapshot */
166 		if (ohci->rh_state != OHCI_RH_RUNNING) {
167 			ohci_dbg (ohci, "BIOS/SMM active, control %03x\n",
168 					ohci->hc_control);
169 			status = -EBUSY;
170 		/* this happens when pmcore resumes HC then root */
171 		} else {
172 			ohci_dbg (ohci, "duplicate resume\n");
173 			status = 0;
174 		}
175 	} else switch (ohci->hc_control & OHCI_CTRL_HCFS) {
176 	case OHCI_USB_SUSPEND:
177 		ohci->hc_control &= ~(OHCI_CTRL_HCFS|OHCI_SCHED_ENABLES);
178 		ohci->hc_control |= OHCI_USB_RESUME;
179 		ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
180 		(void) ohci_readl (ohci, &ohci->regs->control);
181 		ohci_dbg (ohci, "%s root hub\n",
182 				autostopped ? "auto-start" : "resume");
183 		break;
184 	case OHCI_USB_RESUME:
185 		/* HCFS changes sometime after INTR_RD */
186 		ohci_dbg(ohci, "%swakeup root hub\n",
187 				autostopped ? "auto-" : "");
188 		break;
189 	case OHCI_USB_OPER:
190 		/* this can happen after resuming a swsusp snapshot */
191 		ohci_dbg (ohci, "snapshot resume? reinit\n");
192 		status = -EBUSY;
193 		break;
194 	default:		/* RESET, we lost power */
195 		ohci_dbg (ohci, "lost power\n");
196 		status = -EBUSY;
197 	}
198 	if (status == -EBUSY) {
199 		if (!autostopped) {
200 			spin_unlock_irq (&ohci->lock);
201 			status = ohci_restart (ohci);
202 
203 			usb_root_hub_lost_power(hcd->self.root_hub);
204 
205 			spin_lock_irq (&ohci->lock);
206 		}
207 		return status;
208 	}
209 	if (status != -EINPROGRESS)
210 		return status;
211 	if (autostopped)
212 		goto skip_resume;
213 	spin_unlock_irq (&ohci->lock);
214 
215 	/* Some controllers (lucent erratum) need extra-long delays */
216 	msleep (20 /* usb 11.5.1.10 */ + 12 /* 32 msec counter */ + 1);
217 
218 	temp = ohci_readl (ohci, &ohci->regs->control);
219 	temp &= OHCI_CTRL_HCFS;
220 	if (temp != OHCI_USB_RESUME) {
221 		ohci_err (ohci, "controller won't resume\n");
222 		spin_lock_irq(&ohci->lock);
223 		return -EBUSY;
224 	}
225 
226 	/* disable old schedule state, reinit from scratch */
227 	ohci_writel (ohci, 0, &ohci->regs->ed_controlhead);
228 	ohci_writel (ohci, 0, &ohci->regs->ed_controlcurrent);
229 	ohci_writel (ohci, 0, &ohci->regs->ed_bulkhead);
230 	ohci_writel (ohci, 0, &ohci->regs->ed_bulkcurrent);
231 	ohci_writel (ohci, 0, &ohci->regs->ed_periodcurrent);
232 	ohci_writel (ohci, (u32) ohci->hcca_dma, &ohci->regs->hcca);
233 
234 	/* Sometimes PCI D3 suspend trashes frame timings ... */
235 	periodic_reinit (ohci);
236 
237 	/*
238 	 * The following code is executed with ohci->lock held and
239 	 * irqs disabled if and only if autostopped is true.  This
240 	 * will cause sparse to warn about a "context imbalance".
241 	 */
242 skip_resume:
243 	/* interrupts might have been disabled */
244 	ohci_writel (ohci, OHCI_INTR_INIT, &ohci->regs->intrenable);
245 	if (ohci->ed_rm_list)
246 		ohci_writel (ohci, OHCI_INTR_SF, &ohci->regs->intrenable);
247 
248 	/* Then re-enable operations */
249 	ohci_writel (ohci, OHCI_USB_OPER, &ohci->regs->control);
250 	(void) ohci_readl (ohci, &ohci->regs->control);
251 	if (!autostopped)
252 		msleep (3);
253 
254 	temp = ohci->hc_control;
255 	temp &= OHCI_CTRL_RWC;
256 	temp |= OHCI_CONTROL_INIT | OHCI_USB_OPER;
257 	ohci->hc_control = temp;
258 	ohci_writel (ohci, temp, &ohci->regs->control);
259 	(void) ohci_readl (ohci, &ohci->regs->control);
260 
261 	/* TRSMRCY */
262 	if (!autostopped) {
263 		msleep (10);
264 		spin_lock_irq (&ohci->lock);
265 	}
266 	/* now ohci->lock is always held and irqs are always disabled */
267 
268 	/* keep it alive for more than ~5x suspend + resume costs */
269 	ohci->next_statechange = jiffies + STATECHANGE_DELAY;
270 
271 	/* maybe turn schedules back on */
272 	enables = 0;
273 	temp = 0;
274 	if (!ohci->ed_rm_list) {
275 		if (ohci->ed_controltail) {
276 			ohci_writel (ohci,
277 					find_head (ohci->ed_controltail)->dma,
278 					&ohci->regs->ed_controlhead);
279 			enables |= OHCI_CTRL_CLE;
280 			temp |= OHCI_CLF;
281 		}
282 		if (ohci->ed_bulktail) {
283 			ohci_writel (ohci, find_head (ohci->ed_bulktail)->dma,
284 				&ohci->regs->ed_bulkhead);
285 			enables |= OHCI_CTRL_BLE;
286 			temp |= OHCI_BLF;
287 		}
288 	}
289 	if (hcd->self.bandwidth_isoc_reqs || hcd->self.bandwidth_int_reqs)
290 		enables |= OHCI_CTRL_PLE|OHCI_CTRL_IE;
291 	if (enables) {
292 		ohci_dbg (ohci, "restarting schedules ... %08x\n", enables);
293 		ohci->hc_control |= enables;
294 		ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
295 		if (temp)
296 			ohci_writel (ohci, temp, &ohci->regs->cmdstatus);
297 		(void) ohci_readl (ohci, &ohci->regs->control);
298 	}
299 
300 	ohci->rh_state = OHCI_RH_RUNNING;
301 	return 0;
302 }
303 
304 static int ohci_bus_suspend (struct usb_hcd *hcd)
305 {
306 	struct ohci_hcd		*ohci = hcd_to_ohci (hcd);
307 	int			rc;
308 
309 	spin_lock_irq (&ohci->lock);
310 
311 	if (unlikely(!HCD_HW_ACCESSIBLE(hcd)))
312 		rc = -ESHUTDOWN;
313 	else
314 		rc = ohci_rh_suspend (ohci, 0);
315 	spin_unlock_irq (&ohci->lock);
316 
317 	if (rc == 0) {
318 		del_timer_sync(&ohci->io_watchdog);
319 		ohci->prev_frame_no = IO_WATCHDOG_OFF;
320 	}
321 	return rc;
322 }
323 
324 static int ohci_bus_resume (struct usb_hcd *hcd)
325 {
326 	struct ohci_hcd		*ohci = hcd_to_ohci (hcd);
327 	int			rc;
328 
329 	if (time_before (jiffies, ohci->next_statechange))
330 		msleep(5);
331 
332 	spin_lock_irq (&ohci->lock);
333 
334 	if (unlikely(!HCD_HW_ACCESSIBLE(hcd)))
335 		rc = -ESHUTDOWN;
336 	else
337 		rc = ohci_rh_resume (ohci);
338 	spin_unlock_irq (&ohci->lock);
339 
340 	/* poll until we know a device is connected or we autostop */
341 	if (rc == 0)
342 		usb_hcd_poll_rh_status(hcd);
343 	return rc;
344 }
345 
346 /* Carry out polling-, autostop-, and autoresume-related state changes */
347 static int ohci_root_hub_state_changes(struct ohci_hcd *ohci, int changed,
348 		int any_connected, int rhsc_status)
349 {
350 	int	poll_rh = 1;
351 	int	rhsc_enable;
352 
353 	/* Some broken controllers never turn off RHSC in the interrupt
354 	 * status register.  For their sake we won't re-enable RHSC
355 	 * interrupts if the interrupt bit is already active.
356 	 */
357 	rhsc_enable = ohci_readl(ohci, &ohci->regs->intrenable) &
358 			OHCI_INTR_RHSC;
359 
360 	switch (ohci->hc_control & OHCI_CTRL_HCFS) {
361 	case OHCI_USB_OPER:
362 		/* If no status changes are pending, enable RHSC interrupts. */
363 		if (!rhsc_enable && !rhsc_status && !changed) {
364 			rhsc_enable = OHCI_INTR_RHSC;
365 			ohci_writel(ohci, rhsc_enable, &ohci->regs->intrenable);
366 		}
367 
368 		/* Keep on polling until we know a device is connected
369 		 * and RHSC is enabled, or until we autostop.
370 		 */
371 		if (!ohci->autostop) {
372 			if (any_connected ||
373 					!device_may_wakeup(&ohci_to_hcd(ohci)
374 						->self.root_hub->dev)) {
375 				if (rhsc_enable)
376 					poll_rh = 0;
377 			} else {
378 				ohci->autostop = 1;
379 				ohci->next_statechange = jiffies + HZ;
380 			}
381 
382 		/* if no devices have been attached for one second, autostop */
383 		} else {
384 			if (changed || any_connected) {
385 				ohci->autostop = 0;
386 				ohci->next_statechange = jiffies +
387 						STATECHANGE_DELAY;
388 			} else if (time_after_eq(jiffies,
389 						ohci->next_statechange)
390 					&& !ohci->ed_rm_list
391 					&& !(ohci->hc_control &
392 						OHCI_SCHED_ENABLES)) {
393 				ohci_rh_suspend(ohci, 1);
394 				if (rhsc_enable)
395 					poll_rh = 0;
396 			}
397 		}
398 		break;
399 
400 	case OHCI_USB_SUSPEND:
401 	case OHCI_USB_RESUME:
402 		/* if there is a port change, autostart or ask to be resumed */
403 		if (changed) {
404 			if (ohci->autostop)
405 				ohci_rh_resume(ohci);
406 			else
407 				usb_hcd_resume_root_hub(ohci_to_hcd(ohci));
408 
409 		/* If remote wakeup is disabled, stop polling */
410 		} else if (!ohci->autostop &&
411 				!ohci_to_hcd(ohci)->self.root_hub->
412 					do_remote_wakeup) {
413 			poll_rh = 0;
414 
415 		} else {
416 			/* If no status changes are pending,
417 			 * enable RHSC interrupts
418 			 */
419 			if (!rhsc_enable && !rhsc_status) {
420 				rhsc_enable = OHCI_INTR_RHSC;
421 				ohci_writel(ohci, rhsc_enable,
422 						&ohci->regs->intrenable);
423 			}
424 			/* Keep polling until RHSC is enabled */
425 			if (rhsc_enable)
426 				poll_rh = 0;
427 		}
428 		break;
429 	}
430 	return poll_rh;
431 }
432 
433 #else	/* CONFIG_PM */
434 
435 static inline int ohci_rh_resume(struct ohci_hcd *ohci)
436 {
437 	return 0;
438 }
439 
440 /* Carry out polling-related state changes.
441  * autostop isn't used when CONFIG_PM is turned off.
442  */
443 static int ohci_root_hub_state_changes(struct ohci_hcd *ohci, int changed,
444 		int any_connected, int rhsc_status)
445 {
446 	/* If RHSC is enabled, don't poll */
447 	if (ohci_readl(ohci, &ohci->regs->intrenable) & OHCI_INTR_RHSC)
448 		return 0;
449 
450 	/* If status changes are pending, continue polling.
451 	 * Conversely, if no status changes are pending but the RHSC
452 	 * status bit was set, then RHSC may be broken so continue polling.
453 	 */
454 	if (changed || rhsc_status)
455 		return 1;
456 
457 	/* It's safe to re-enable RHSC interrupts */
458 	ohci_writel(ohci, OHCI_INTR_RHSC, &ohci->regs->intrenable);
459 	return 0;
460 }
461 
462 #endif	/* CONFIG_PM */
463 
464 /*-------------------------------------------------------------------------*/
465 
466 /* build "status change" packet (one or two bytes) from HC registers */
467 
468 int ohci_hub_status_data(struct usb_hcd *hcd, char *buf)
469 {
470 	struct ohci_hcd	*ohci = hcd_to_ohci (hcd);
471 	int		i, changed = 0, length = 1;
472 	int		any_connected = 0;
473 	int		rhsc_status;
474 	unsigned long	flags;
475 
476 	spin_lock_irqsave (&ohci->lock, flags);
477 	if (!HCD_HW_ACCESSIBLE(hcd))
478 		goto done;
479 
480 	/* undocumented erratum seen on at least rev D */
481 	if ((ohci->flags & OHCI_QUIRK_AMD756)
482 			&& (roothub_a (ohci) & RH_A_NDP) > MAX_ROOT_PORTS) {
483 		ohci_warn (ohci, "bogus NDP, rereads as NDP=%d\n",
484 			  ohci_readl (ohci, &ohci->regs->roothub.a) & RH_A_NDP);
485 		/* retry later; "should not happen" */
486 		goto done;
487 	}
488 
489 	/* init status */
490 	if (roothub_status (ohci) & (RH_HS_LPSC | RH_HS_OCIC))
491 		buf [0] = changed = 1;
492 	else
493 		buf [0] = 0;
494 	if (ohci->num_ports > 7) {
495 		buf [1] = 0;
496 		length++;
497 	}
498 
499 	/* Clear the RHSC status flag before reading the port statuses */
500 	ohci_writel(ohci, OHCI_INTR_RHSC, &ohci->regs->intrstatus);
501 	rhsc_status = ohci_readl(ohci, &ohci->regs->intrstatus) &
502 			OHCI_INTR_RHSC;
503 
504 	/* look at each port */
505 	for (i = 0; i < ohci->num_ports; i++) {
506 		u32	status = roothub_portstatus (ohci, i);
507 
508 		/* can't autostop if ports are connected */
509 		any_connected |= (status & RH_PS_CCS);
510 
511 		if (status & (RH_PS_CSC | RH_PS_PESC | RH_PS_PSSC
512 				| RH_PS_OCIC | RH_PS_PRSC)) {
513 			changed = 1;
514 			if (i < 7)
515 			    buf [0] |= 1 << (i + 1);
516 			else
517 			    buf [1] |= 1 << (i - 7);
518 		}
519 	}
520 
521 	if (ohci_root_hub_state_changes(ohci, changed,
522 			any_connected, rhsc_status))
523 		set_bit(HCD_FLAG_POLL_RH, &hcd->flags);
524 	else
525 		clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
526 
527 
528 done:
529 	spin_unlock_irqrestore (&ohci->lock, flags);
530 
531 	return changed ? length : 0;
532 }
533 EXPORT_SYMBOL_GPL(ohci_hub_status_data);
534 
535 /*-------------------------------------------------------------------------*/
536 
537 static void
538 ohci_hub_descriptor (
539 	struct ohci_hcd			*ohci,
540 	struct usb_hub_descriptor	*desc
541 ) {
542 	u32		rh = roothub_a (ohci);
543 	u16		temp;
544 
545 	desc->bDescriptorType = USB_DT_HUB;
546 	desc->bPwrOn2PwrGood = (rh & RH_A_POTPGT) >> 24;
547 	desc->bHubContrCurrent = 0;
548 
549 	desc->bNbrPorts = ohci->num_ports;
550 	temp = 1 + (ohci->num_ports / 8);
551 	desc->bDescLength = 7 + 2 * temp;
552 
553 	temp = HUB_CHAR_COMMON_LPSM | HUB_CHAR_COMMON_OCPM;
554 	if (rh & RH_A_NPS)		/* no power switching? */
555 		temp |= HUB_CHAR_NO_LPSM;
556 	if (rh & RH_A_PSM)		/* per-port power switching? */
557 		temp |= HUB_CHAR_INDV_PORT_LPSM;
558 	if (rh & RH_A_NOCP)		/* no overcurrent reporting? */
559 		temp |= HUB_CHAR_NO_OCPM;
560 	else if (rh & RH_A_OCPM)	/* per-port overcurrent reporting? */
561 		temp |= HUB_CHAR_INDV_PORT_OCPM;
562 	desc->wHubCharacteristics = cpu_to_le16(temp);
563 
564 	/* ports removable, and usb 1.0 legacy PortPwrCtrlMask */
565 	rh = roothub_b (ohci);
566 	memset(desc->u.hs.DeviceRemovable, 0xff,
567 			sizeof(desc->u.hs.DeviceRemovable));
568 	desc->u.hs.DeviceRemovable[0] = rh & RH_B_DR;
569 	if (ohci->num_ports > 7) {
570 		desc->u.hs.DeviceRemovable[1] = (rh & RH_B_DR) >> 8;
571 		desc->u.hs.DeviceRemovable[2] = 0xff;
572 	} else
573 		desc->u.hs.DeviceRemovable[1] = 0xff;
574 }
575 
576 /*-------------------------------------------------------------------------*/
577 
578 #ifdef	CONFIG_USB_OTG
579 
580 static int ohci_start_port_reset (struct usb_hcd *hcd, unsigned port)
581 {
582 	struct ohci_hcd	*ohci = hcd_to_ohci (hcd);
583 	u32			status;
584 
585 	if (!port)
586 		return -EINVAL;
587 	port--;
588 
589 	/* start port reset before HNP protocol times out */
590 	status = ohci_readl(ohci, &ohci->regs->roothub.portstatus [port]);
591 	if (!(status & RH_PS_CCS))
592 		return -ENODEV;
593 
594 	/* hub_wq will finish the reset later */
595 	ohci_writel(ohci, RH_PS_PRS, &ohci->regs->roothub.portstatus [port]);
596 	return 0;
597 }
598 
599 #else
600 
601 #define	ohci_start_port_reset		NULL
602 
603 #endif
604 
605 /*-------------------------------------------------------------------------*/
606 
607 
608 /* See usb 7.1.7.5:  root hubs must issue at least 50 msec reset signaling,
609  * not necessarily continuous ... to guard against resume signaling.
610  */
611 #define	PORT_RESET_MSEC		50
612 
613 /* this timer value might be vendor-specific ... */
614 #define	PORT_RESET_HW_MSEC	10
615 
616 /* wrap-aware logic morphed from <linux/jiffies.h> */
617 #define tick_before(t1,t2) ((s16)(((s16)(t1))-((s16)(t2))) < 0)
618 
619 /* called from some task, normally hub_wq */
620 static inline int root_port_reset (struct ohci_hcd *ohci, unsigned port)
621 {
622 	__hc32 __iomem *portstat = &ohci->regs->roothub.portstatus [port];
623 	u32	temp = 0;
624 	u16	now = ohci_readl(ohci, &ohci->regs->fmnumber);
625 	u16	reset_done = now + PORT_RESET_MSEC;
626 	int	limit_1 = DIV_ROUND_UP(PORT_RESET_MSEC, PORT_RESET_HW_MSEC);
627 
628 	/* build a "continuous enough" reset signal, with up to
629 	 * 3msec gap between pulses.  scheduler HZ==100 must work;
630 	 * this might need to be deadline-scheduled.
631 	 */
632 	do {
633 		int limit_2;
634 
635 		/* spin until any current reset finishes */
636 		limit_2 = PORT_RESET_HW_MSEC * 2;
637 		while (--limit_2 >= 0) {
638 			temp = ohci_readl (ohci, portstat);
639 			/* handle e.g. CardBus eject */
640 			if (temp == ~(u32)0)
641 				return -ESHUTDOWN;
642 			if (!(temp & RH_PS_PRS))
643 				break;
644 			udelay (500);
645 		}
646 
647 		/* timeout (a hardware error) has been observed when
648 		 * EHCI sets CF while this driver is resetting a port;
649 		 * presumably other disconnect paths might do it too.
650 		 */
651 		if (limit_2 < 0) {
652 			ohci_dbg(ohci,
653 				"port[%d] reset timeout, stat %08x\n",
654 				port, temp);
655 			break;
656 		}
657 
658 		if (!(temp & RH_PS_CCS))
659 			break;
660 		if (temp & RH_PS_PRSC)
661 			ohci_writel (ohci, RH_PS_PRSC, portstat);
662 
663 		/* start the next reset, sleep till it's probably done */
664 		ohci_writel (ohci, RH_PS_PRS, portstat);
665 		msleep(PORT_RESET_HW_MSEC);
666 		now = ohci_readl(ohci, &ohci->regs->fmnumber);
667 	} while (tick_before(now, reset_done) && --limit_1 >= 0);
668 
669 	/* caller synchronizes using PRSC ... and handles PRS
670 	 * still being set when this returns.
671 	 */
672 
673 	return 0;
674 }
675 
676 int ohci_hub_control(
677 	struct usb_hcd	*hcd,
678 	u16		typeReq,
679 	u16		wValue,
680 	u16		wIndex,
681 	char		*buf,
682 	u16		wLength
683 ) {
684 	struct ohci_hcd	*ohci = hcd_to_ohci (hcd);
685 	int		ports = ohci->num_ports;
686 	u32		temp;
687 	int		retval = 0;
688 
689 	if (unlikely(!HCD_HW_ACCESSIBLE(hcd)))
690 		return -ESHUTDOWN;
691 
692 	switch (typeReq) {
693 	case ClearHubFeature:
694 		switch (wValue) {
695 		case C_HUB_OVER_CURRENT:
696 			ohci_writel (ohci, RH_HS_OCIC,
697 					&ohci->regs->roothub.status);
698 			break;
699 		case C_HUB_LOCAL_POWER:
700 			break;
701 		default:
702 			goto error;
703 		}
704 		break;
705 	case ClearPortFeature:
706 		if (!wIndex || wIndex > ports)
707 			goto error;
708 		wIndex--;
709 
710 		switch (wValue) {
711 		case USB_PORT_FEAT_ENABLE:
712 			temp = RH_PS_CCS;
713 			break;
714 		case USB_PORT_FEAT_C_ENABLE:
715 			temp = RH_PS_PESC;
716 			break;
717 		case USB_PORT_FEAT_SUSPEND:
718 			temp = RH_PS_POCI;
719 			break;
720 		case USB_PORT_FEAT_C_SUSPEND:
721 			temp = RH_PS_PSSC;
722 			break;
723 		case USB_PORT_FEAT_POWER:
724 			temp = RH_PS_LSDA;
725 			break;
726 		case USB_PORT_FEAT_C_CONNECTION:
727 			temp = RH_PS_CSC;
728 			break;
729 		case USB_PORT_FEAT_C_OVER_CURRENT:
730 			temp = RH_PS_OCIC;
731 			break;
732 		case USB_PORT_FEAT_C_RESET:
733 			temp = RH_PS_PRSC;
734 			break;
735 		default:
736 			goto error;
737 		}
738 		ohci_writel (ohci, temp,
739 				&ohci->regs->roothub.portstatus [wIndex]);
740 		// ohci_readl (ohci, &ohci->regs->roothub.portstatus [wIndex]);
741 		break;
742 	case GetHubDescriptor:
743 		ohci_hub_descriptor (ohci, (struct usb_hub_descriptor *) buf);
744 		break;
745 	case GetHubStatus:
746 		temp = roothub_status (ohci) & ~(RH_HS_CRWE | RH_HS_DRWE);
747 		put_unaligned_le32(temp, buf);
748 		break;
749 	case GetPortStatus:
750 		if (!wIndex || wIndex > ports)
751 			goto error;
752 		wIndex--;
753 		temp = roothub_portstatus (ohci, wIndex);
754 		put_unaligned_le32(temp, buf);
755 
756 		if (*(u16*)(buf+2))	/* only if wPortChange is interesting */
757 			dbg_port(ohci, "GetStatus", wIndex, temp);
758 		break;
759 	case SetHubFeature:
760 		switch (wValue) {
761 		case C_HUB_OVER_CURRENT:
762 			// FIXME:  this can be cleared, yes?
763 		case C_HUB_LOCAL_POWER:
764 			break;
765 		default:
766 			goto error;
767 		}
768 		break;
769 	case SetPortFeature:
770 		if (!wIndex || wIndex > ports)
771 			goto error;
772 		wIndex--;
773 		switch (wValue) {
774 		case USB_PORT_FEAT_SUSPEND:
775 #ifdef	CONFIG_USB_OTG
776 			if (hcd->self.otg_port == (wIndex + 1)
777 					&& hcd->self.b_hnp_enable)
778 				ohci->start_hnp(ohci);
779 			else
780 #endif
781 			ohci_writel (ohci, RH_PS_PSS,
782 				&ohci->regs->roothub.portstatus [wIndex]);
783 			break;
784 		case USB_PORT_FEAT_POWER:
785 			ohci_writel (ohci, RH_PS_PPS,
786 				&ohci->regs->roothub.portstatus [wIndex]);
787 			break;
788 		case USB_PORT_FEAT_RESET:
789 			retval = root_port_reset (ohci, wIndex);
790 			break;
791 		default:
792 			goto error;
793 		}
794 		break;
795 
796 	default:
797 error:
798 		/* "protocol stall" on error */
799 		retval = -EPIPE;
800 	}
801 	return retval;
802 }
803 EXPORT_SYMBOL_GPL(ohci_hub_control);
804