xref: /openbmc/linux/drivers/usb/host/ehci-hub.c (revision c21b37f6)
1 /*
2  * Copyright (C) 2001-2004 by David Brownell
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms of the GNU General Public License as published by the
6  * Free Software Foundation; either version 2 of the License, or (at your
7  * option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful, but
10  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
11  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12  * for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software Foundation,
16  * Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
17  */
18 
19 /* this file is part of ehci-hcd.c */
20 
21 /*-------------------------------------------------------------------------*/
22 
23 /*
24  * EHCI Root Hub ... the nonsharable stuff
25  *
26  * Registers don't need cpu_to_le32, that happens transparently
27  */
28 
29 /*-------------------------------------------------------------------------*/
30 
31 #ifdef	CONFIG_USB_PERSIST
32 
33 static int ehci_hub_control(
34 	struct usb_hcd	*hcd,
35 	u16		typeReq,
36 	u16		wValue,
37 	u16		wIndex,
38 	char		*buf,
39 	u16		wLength
40 );
41 
42 /* After a power loss, ports that were owned by the companion must be
43  * reset so that the companion can still own them.
44  */
45 static void ehci_handover_companion_ports(struct ehci_hcd *ehci)
46 {
47 	u32 __iomem	*reg;
48 	u32		status;
49 	int		port;
50 	__le32		buf;
51 	struct usb_hcd	*hcd = ehci_to_hcd(ehci);
52 
53 	if (!ehci->owned_ports)
54 		return;
55 
56 	/* Give the connections some time to appear */
57 	msleep(20);
58 
59 	port = HCS_N_PORTS(ehci->hcs_params);
60 	while (port--) {
61 		if (test_bit(port, &ehci->owned_ports)) {
62 			reg = &ehci->regs->port_status[port];
63 			status = ehci_readl(ehci, reg) & ~PORT_RWC_BITS;
64 
65 			/* Port already owned by companion? */
66 			if (status & PORT_OWNER)
67 				clear_bit(port, &ehci->owned_ports);
68 			else if (test_bit(port, &ehci->companion_ports))
69 				ehci_writel(ehci, status & ~PORT_PE, reg);
70 			else
71 				ehci_hub_control(hcd, SetPortFeature,
72 						USB_PORT_FEAT_RESET, port + 1,
73 						NULL, 0);
74 		}
75 	}
76 
77 	if (!ehci->owned_ports)
78 		return;
79 	msleep(90);		/* Wait for resets to complete */
80 
81 	port = HCS_N_PORTS(ehci->hcs_params);
82 	while (port--) {
83 		if (test_bit(port, &ehci->owned_ports)) {
84 			ehci_hub_control(hcd, GetPortStatus,
85 					0, port + 1,
86 					(char *) &buf, sizeof(buf));
87 
88 			/* The companion should now own the port,
89 			 * but if something went wrong the port must not
90 			 * remain enabled.
91 			 */
92 			reg = &ehci->regs->port_status[port];
93 			status = ehci_readl(ehci, reg) & ~PORT_RWC_BITS;
94 			if (status & PORT_OWNER)
95 				ehci_writel(ehci, status | PORT_CSC, reg);
96 			else {
97 				ehci_dbg(ehci, "failed handover port %d: %x\n",
98 						port + 1, status);
99 				ehci_writel(ehci, status & ~PORT_PE, reg);
100 			}
101 		}
102 	}
103 
104 	ehci->owned_ports = 0;
105 }
106 
107 #else	/* CONFIG_USB_PERSIST */
108 
109 static inline void ehci_handover_companion_ports(struct ehci_hcd *ehci)
110 { }
111 
112 #endif
113 
114 #ifdef	CONFIG_PM
115 
116 static int ehci_bus_suspend (struct usb_hcd *hcd)
117 {
118 	struct ehci_hcd		*ehci = hcd_to_ehci (hcd);
119 	int			port;
120 	int			mask;
121 
122 	ehci_dbg(ehci, "suspend root hub\n");
123 
124 	if (time_before (jiffies, ehci->next_statechange))
125 		msleep(5);
126 
127 	port = HCS_N_PORTS (ehci->hcs_params);
128 	spin_lock_irq (&ehci->lock);
129 
130 	/* stop schedules, clean any completed work */
131 	if (HC_IS_RUNNING(hcd->state)) {
132 		ehci_quiesce (ehci);
133 		hcd->state = HC_STATE_QUIESCING;
134 	}
135 	ehci->command = ehci_readl(ehci, &ehci->regs->command);
136 	if (ehci->reclaim)
137 		ehci->reclaim_ready = 1;
138 	ehci_work(ehci);
139 
140 	/* Unlike other USB host controller types, EHCI doesn't have
141 	 * any notion of "global" or bus-wide suspend.  The driver has
142 	 * to manually suspend all the active unsuspended ports, and
143 	 * then manually resume them in the bus_resume() routine.
144 	 */
145 	ehci->bus_suspended = 0;
146 	ehci->owned_ports = 0;
147 	while (port--) {
148 		u32 __iomem	*reg = &ehci->regs->port_status [port];
149 		u32		t1 = ehci_readl(ehci, reg) & ~PORT_RWC_BITS;
150 		u32		t2 = t1;
151 
152 		/* keep track of which ports we suspend */
153 		if (t1 & PORT_OWNER)
154 			set_bit(port, &ehci->owned_ports);
155 		else if ((t1 & PORT_PE) && !(t1 & PORT_SUSPEND)) {
156 			t2 |= PORT_SUSPEND;
157 			set_bit(port, &ehci->bus_suspended);
158 		}
159 
160 		/* enable remote wakeup on all ports */
161 		if (device_may_wakeup(&hcd->self.root_hub->dev))
162 			t2 |= PORT_WKOC_E|PORT_WKDISC_E|PORT_WKCONN_E;
163 		else
164 			t2 &= ~(PORT_WKOC_E|PORT_WKDISC_E|PORT_WKCONN_E);
165 
166 		if (t1 != t2) {
167 			ehci_vdbg (ehci, "port %d, %08x -> %08x\n",
168 				port + 1, t1, t2);
169 			ehci_writel(ehci, t2, reg);
170 		}
171 	}
172 
173 	/* turn off now-idle HC */
174 	del_timer_sync (&ehci->watchdog);
175 	ehci_halt (ehci);
176 	hcd->state = HC_STATE_SUSPENDED;
177 
178 	/* allow remote wakeup */
179 	mask = INTR_MASK;
180 	if (!device_may_wakeup(&hcd->self.root_hub->dev))
181 		mask &= ~STS_PCD;
182 	ehci_writel(ehci, mask, &ehci->regs->intr_enable);
183 	ehci_readl(ehci, &ehci->regs->intr_enable);
184 
185 	ehci->next_statechange = jiffies + msecs_to_jiffies(10);
186 	spin_unlock_irq (&ehci->lock);
187 	return 0;
188 }
189 
190 
191 /* caller has locked the root hub, and should reset/reinit on error */
192 static int ehci_bus_resume (struct usb_hcd *hcd)
193 {
194 	struct ehci_hcd		*ehci = hcd_to_ehci (hcd);
195 	u32			temp;
196 	u32			power_okay;
197 	int			i;
198 
199 	if (time_before (jiffies, ehci->next_statechange))
200 		msleep(5);
201 	spin_lock_irq (&ehci->lock);
202 	if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags)) {
203 		spin_unlock_irq(&ehci->lock);
204 		return -ESHUTDOWN;
205 	}
206 
207 	/* Ideally and we've got a real resume here, and no port's power
208 	 * was lost.  (For PCI, that means Vaux was maintained.)  But we
209 	 * could instead be restoring a swsusp snapshot -- so that BIOS was
210 	 * the last user of the controller, not reset/pm hardware keeping
211 	 * state we gave to it.
212 	 */
213 	power_okay = ehci_readl(ehci, &ehci->regs->intr_enable);
214 	ehci_dbg(ehci, "resume root hub%s\n",
215 			power_okay ? "" : " after power loss");
216 
217 	/* at least some APM implementations will try to deliver
218 	 * IRQs right away, so delay them until we're ready.
219 	 */
220 	ehci_writel(ehci, 0, &ehci->regs->intr_enable);
221 
222 	/* re-init operational registers */
223 	ehci_writel(ehci, 0, &ehci->regs->segment);
224 	ehci_writel(ehci, ehci->periodic_dma, &ehci->regs->frame_list);
225 	ehci_writel(ehci, (u32) ehci->async->qh_dma, &ehci->regs->async_next);
226 
227 	/* restore CMD_RUN, framelist size, and irq threshold */
228 	ehci_writel(ehci, ehci->command, &ehci->regs->command);
229 
230 	/* Some controller/firmware combinations need a delay during which
231 	 * they set up the port statuses.  See Bugzilla #8190. */
232 	mdelay(8);
233 
234 	/* manually resume the ports we suspended during bus_suspend() */
235 	i = HCS_N_PORTS (ehci->hcs_params);
236 	while (i--) {
237 		temp = ehci_readl(ehci, &ehci->regs->port_status [i]);
238 		temp &= ~(PORT_RWC_BITS
239 			| PORT_WKOC_E | PORT_WKDISC_E | PORT_WKCONN_E);
240 		if (test_bit(i, &ehci->bus_suspended) &&
241 				(temp & PORT_SUSPEND)) {
242 			ehci->reset_done [i] = jiffies + msecs_to_jiffies (20);
243 			temp |= PORT_RESUME;
244 		}
245 		ehci_writel(ehci, temp, &ehci->regs->port_status [i]);
246 	}
247 	i = HCS_N_PORTS (ehci->hcs_params);
248 	mdelay (20);
249 	while (i--) {
250 		temp = ehci_readl(ehci, &ehci->regs->port_status [i]);
251 		if (test_bit(i, &ehci->bus_suspended) &&
252 				(temp & PORT_SUSPEND)) {
253 			temp &= ~(PORT_RWC_BITS | PORT_RESUME);
254 			ehci_writel(ehci, temp, &ehci->regs->port_status [i]);
255 			ehci_vdbg (ehci, "resumed port %d\n", i + 1);
256 		}
257 	}
258 	(void) ehci_readl(ehci, &ehci->regs->command);
259 
260 	/* maybe re-activate the schedule(s) */
261 	temp = 0;
262 	if (ehci->async->qh_next.qh)
263 		temp |= CMD_ASE;
264 	if (ehci->periodic_sched)
265 		temp |= CMD_PSE;
266 	if (temp) {
267 		ehci->command |= temp;
268 		ehci_writel(ehci, ehci->command, &ehci->regs->command);
269 	}
270 
271 	ehci->next_statechange = jiffies + msecs_to_jiffies(5);
272 	hcd->state = HC_STATE_RUNNING;
273 
274 	/* Now we can safely re-enable irqs */
275 	ehci_writel(ehci, INTR_MASK, &ehci->regs->intr_enable);
276 
277 	spin_unlock_irq (&ehci->lock);
278 
279 	if (!power_okay)
280 		ehci_handover_companion_ports(ehci);
281 	return 0;
282 }
283 
284 #else
285 
286 #define ehci_bus_suspend	NULL
287 #define ehci_bus_resume		NULL
288 
289 #endif	/* CONFIG_PM */
290 
291 /*-------------------------------------------------------------------------*/
292 
293 /* Display the ports dedicated to the companion controller */
294 static ssize_t show_companion(struct class_device *class_dev, char *buf)
295 {
296 	struct ehci_hcd		*ehci;
297 	int			nports, index, n;
298 	int			count = PAGE_SIZE;
299 	char			*ptr = buf;
300 
301 	ehci = hcd_to_ehci(bus_to_hcd(class_get_devdata(class_dev)));
302 	nports = HCS_N_PORTS(ehci->hcs_params);
303 
304 	for (index = 0; index < nports; ++index) {
305 		if (test_bit(index, &ehci->companion_ports)) {
306 			n = scnprintf(ptr, count, "%d\n", index + 1);
307 			ptr += n;
308 			count -= n;
309 		}
310 	}
311 	return ptr - buf;
312 }
313 
314 /*
315  * Dedicate or undedicate a port to the companion controller.
316  * Syntax is "[-]portnum", where a leading '-' sign means
317  * return control of the port to the EHCI controller.
318  */
319 static ssize_t store_companion(struct class_device *class_dev,
320 		const char *buf, size_t count)
321 {
322 	struct ehci_hcd		*ehci;
323 	int			portnum, new_owner, try;
324 	u32 __iomem		*status_reg;
325 	u32			port_status;
326 
327 	ehci = hcd_to_ehci(bus_to_hcd(class_get_devdata(class_dev)));
328 	new_owner = PORT_OWNER;		/* Owned by companion */
329 	if (sscanf(buf, "%d", &portnum) != 1)
330 		return -EINVAL;
331 	if (portnum < 0) {
332 		portnum = - portnum;
333 		new_owner = 0;		/* Owned by EHCI */
334 	}
335 	if (portnum <= 0 || portnum > HCS_N_PORTS(ehci->hcs_params))
336 		return -ENOENT;
337 	status_reg = &ehci->regs->port_status[--portnum];
338 	if (new_owner)
339 		set_bit(portnum, &ehci->companion_ports);
340 	else
341 		clear_bit(portnum, &ehci->companion_ports);
342 
343 	/*
344 	 * The controller won't set the OWNER bit if the port is
345 	 * enabled, so this loop will sometimes require at least two
346 	 * iterations: one to disable the port and one to set OWNER.
347 	 */
348 
349 	for (try = 4; try > 0; --try) {
350 		spin_lock_irq(&ehci->lock);
351 		port_status = ehci_readl(ehci, status_reg);
352 		if ((port_status & PORT_OWNER) == new_owner
353 				|| (port_status & (PORT_OWNER | PORT_CONNECT))
354 					== 0)
355 			try = 0;
356 		else {
357 			port_status ^= PORT_OWNER;
358 			port_status &= ~(PORT_PE | PORT_RWC_BITS);
359 			ehci_writel(ehci, port_status, status_reg);
360 		}
361 		spin_unlock_irq(&ehci->lock);
362 		if (try > 1)
363 			msleep(5);
364 	}
365 	return count;
366 }
367 static CLASS_DEVICE_ATTR(companion, 0644, show_companion, store_companion);
368 
369 static inline void create_companion_file(struct ehci_hcd *ehci)
370 {
371 	int	i;
372 
373 	/* with integrated TT there is no companion! */
374 	if (!ehci_is_TDI(ehci))
375 		i = class_device_create_file(ehci_to_hcd(ehci)->self.class_dev,
376 				&class_device_attr_companion);
377 }
378 
379 static inline void remove_companion_file(struct ehci_hcd *ehci)
380 {
381 	/* with integrated TT there is no companion! */
382 	if (!ehci_is_TDI(ehci))
383 		class_device_remove_file(ehci_to_hcd(ehci)->self.class_dev,
384 				&class_device_attr_companion);
385 }
386 
387 
388 /*-------------------------------------------------------------------------*/
389 
390 static int check_reset_complete (
391 	struct ehci_hcd	*ehci,
392 	int		index,
393 	u32 __iomem	*status_reg,
394 	int		port_status
395 ) {
396 	if (!(port_status & PORT_CONNECT)) {
397 		ehci->reset_done [index] = 0;
398 		return port_status;
399 	}
400 
401 	/* if reset finished and it's still not enabled -- handoff */
402 	if (!(port_status & PORT_PE)) {
403 
404 		/* with integrated TT, there's nobody to hand it to! */
405 		if (ehci_is_TDI(ehci)) {
406 			ehci_dbg (ehci,
407 				"Failed to enable port %d on root hub TT\n",
408 				index+1);
409 			return port_status;
410 		}
411 
412 		ehci_dbg (ehci, "port %d full speed --> companion\n",
413 			index + 1);
414 
415 		// what happens if HCS_N_CC(params) == 0 ?
416 		port_status |= PORT_OWNER;
417 		port_status &= ~PORT_RWC_BITS;
418 		ehci_writel(ehci, port_status, status_reg);
419 
420 	} else
421 		ehci_dbg (ehci, "port %d high speed\n", index + 1);
422 
423 	return port_status;
424 }
425 
426 /*-------------------------------------------------------------------------*/
427 
428 
429 /* build "status change" packet (one or two bytes) from HC registers */
430 
431 static int
432 ehci_hub_status_data (struct usb_hcd *hcd, char *buf)
433 {
434 	struct ehci_hcd	*ehci = hcd_to_ehci (hcd);
435 	u32		temp, status = 0;
436 	u32		mask;
437 	int		ports, i, retval = 1;
438 	unsigned long	flags;
439 
440 	/* if !USB_SUSPEND, root hub timers won't get shut down ... */
441 	if (!HC_IS_RUNNING(hcd->state))
442 		return 0;
443 
444 	/* init status to no-changes */
445 	buf [0] = 0;
446 	ports = HCS_N_PORTS (ehci->hcs_params);
447 	if (ports > 7) {
448 		buf [1] = 0;
449 		retval++;
450 	}
451 
452 	/* Some boards (mostly VIA?) report bogus overcurrent indications,
453 	 * causing massive log spam unless we completely ignore them.  It
454 	 * may be relevant that VIA VT8235 controlers, where PORT_POWER is
455 	 * always set, seem to clear PORT_OCC and PORT_CSC when writing to
456 	 * PORT_POWER; that's surprising, but maybe within-spec.
457 	 */
458 	if (!ignore_oc)
459 		mask = PORT_CSC | PORT_PEC | PORT_OCC;
460 	else
461 		mask = PORT_CSC | PORT_PEC;
462 	// PORT_RESUME from hardware ~= PORT_STAT_C_SUSPEND
463 
464 	/* no hub change reports (bit 0) for now (power, ...) */
465 
466 	/* port N changes (bit N)? */
467 	spin_lock_irqsave (&ehci->lock, flags);
468 	for (i = 0; i < ports; i++) {
469 		temp = ehci_readl(ehci, &ehci->regs->port_status [i]);
470 
471 		/*
472 		 * Return status information even for ports with OWNER set.
473 		 * Otherwise khubd wouldn't see the disconnect event when a
474 		 * high-speed device is switched over to the companion
475 		 * controller by the user.
476 		 */
477 
478 		if (!(temp & PORT_CONNECT))
479 			ehci->reset_done [i] = 0;
480 		if ((temp & mask) != 0
481 				|| ((temp & PORT_RESUME) != 0
482 					&& time_after_eq(jiffies,
483 						ehci->reset_done[i]))) {
484 			if (i < 7)
485 			    buf [0] |= 1 << (i + 1);
486 			else
487 			    buf [1] |= 1 << (i - 7);
488 			status = STS_PCD;
489 		}
490 	}
491 	/* FIXME autosuspend idle root hubs */
492 	spin_unlock_irqrestore (&ehci->lock, flags);
493 	return status ? retval : 0;
494 }
495 
496 /*-------------------------------------------------------------------------*/
497 
498 static void
499 ehci_hub_descriptor (
500 	struct ehci_hcd			*ehci,
501 	struct usb_hub_descriptor	*desc
502 ) {
503 	int		ports = HCS_N_PORTS (ehci->hcs_params);
504 	u16		temp;
505 
506 	desc->bDescriptorType = 0x29;
507 	desc->bPwrOn2PwrGood = 10;	/* ehci 1.0, 2.3.9 says 20ms max */
508 	desc->bHubContrCurrent = 0;
509 
510 	desc->bNbrPorts = ports;
511 	temp = 1 + (ports / 8);
512 	desc->bDescLength = 7 + 2 * temp;
513 
514 	/* two bitmaps:  ports removable, and usb 1.0 legacy PortPwrCtrlMask */
515 	memset (&desc->bitmap [0], 0, temp);
516 	memset (&desc->bitmap [temp], 0xff, temp);
517 
518 	temp = 0x0008;			/* per-port overcurrent reporting */
519 	if (HCS_PPC (ehci->hcs_params))
520 		temp |= 0x0001;		/* per-port power control */
521 	else
522 		temp |= 0x0002;		/* no power switching */
523 #if 0
524 // re-enable when we support USB_PORT_FEAT_INDICATOR below.
525 	if (HCS_INDICATOR (ehci->hcs_params))
526 		temp |= 0x0080;		/* per-port indicators (LEDs) */
527 #endif
528 	desc->wHubCharacteristics = (__force __u16)cpu_to_le16 (temp);
529 }
530 
531 /*-------------------------------------------------------------------------*/
532 
533 #define	PORT_WAKE_BITS	(PORT_WKOC_E|PORT_WKDISC_E|PORT_WKCONN_E)
534 
535 static int ehci_hub_control (
536 	struct usb_hcd	*hcd,
537 	u16		typeReq,
538 	u16		wValue,
539 	u16		wIndex,
540 	char		*buf,
541 	u16		wLength
542 ) {
543 	struct ehci_hcd	*ehci = hcd_to_ehci (hcd);
544 	int		ports = HCS_N_PORTS (ehci->hcs_params);
545 	u32 __iomem	*status_reg = &ehci->regs->port_status[
546 				(wIndex & 0xff) - 1];
547 	u32		temp, status;
548 	unsigned long	flags;
549 	int		retval = 0;
550 	unsigned	selector;
551 
552 	/*
553 	 * FIXME:  support SetPortFeatures USB_PORT_FEAT_INDICATOR.
554 	 * HCS_INDICATOR may say we can change LEDs to off/amber/green.
555 	 * (track current state ourselves) ... blink for diagnostics,
556 	 * power, "this is the one", etc.  EHCI spec supports this.
557 	 */
558 
559 	spin_lock_irqsave (&ehci->lock, flags);
560 	switch (typeReq) {
561 	case ClearHubFeature:
562 		switch (wValue) {
563 		case C_HUB_LOCAL_POWER:
564 		case C_HUB_OVER_CURRENT:
565 			/* no hub-wide feature/status flags */
566 			break;
567 		default:
568 			goto error;
569 		}
570 		break;
571 	case ClearPortFeature:
572 		if (!wIndex || wIndex > ports)
573 			goto error;
574 		wIndex--;
575 		temp = ehci_readl(ehci, status_reg);
576 
577 		/*
578 		 * Even if OWNER is set, so the port is owned by the
579 		 * companion controller, khubd needs to be able to clear
580 		 * the port-change status bits (especially
581 		 * USB_PORT_FEAT_C_CONNECTION).
582 		 */
583 
584 		switch (wValue) {
585 		case USB_PORT_FEAT_ENABLE:
586 			ehci_writel(ehci, temp & ~PORT_PE, status_reg);
587 			break;
588 		case USB_PORT_FEAT_C_ENABLE:
589 			ehci_writel(ehci, (temp & ~PORT_RWC_BITS) | PORT_PEC,
590 					status_reg);
591 			break;
592 		case USB_PORT_FEAT_SUSPEND:
593 			if (temp & PORT_RESET)
594 				goto error;
595 			if (ehci->no_selective_suspend)
596 				break;
597 			if (temp & PORT_SUSPEND) {
598 				if ((temp & PORT_PE) == 0)
599 					goto error;
600 				/* resume signaling for 20 msec */
601 				temp &= ~(PORT_RWC_BITS | PORT_WAKE_BITS);
602 				ehci_writel(ehci, temp | PORT_RESUME,
603 						status_reg);
604 				ehci->reset_done [wIndex] = jiffies
605 						+ msecs_to_jiffies (20);
606 			}
607 			break;
608 		case USB_PORT_FEAT_C_SUSPEND:
609 			/* we auto-clear this feature */
610 			break;
611 		case USB_PORT_FEAT_POWER:
612 			if (HCS_PPC (ehci->hcs_params))
613 				ehci_writel(ehci,
614 					  temp & ~(PORT_RWC_BITS | PORT_POWER),
615 					  status_reg);
616 			break;
617 		case USB_PORT_FEAT_C_CONNECTION:
618 			ehci_writel(ehci, (temp & ~PORT_RWC_BITS) | PORT_CSC,
619 					status_reg);
620 			break;
621 		case USB_PORT_FEAT_C_OVER_CURRENT:
622 			ehci_writel(ehci, (temp & ~PORT_RWC_BITS) | PORT_OCC,
623 					status_reg);
624 			break;
625 		case USB_PORT_FEAT_C_RESET:
626 			/* GetPortStatus clears reset */
627 			break;
628 		default:
629 			goto error;
630 		}
631 		ehci_readl(ehci, &ehci->regs->command);	/* unblock posted write */
632 		break;
633 	case GetHubDescriptor:
634 		ehci_hub_descriptor (ehci, (struct usb_hub_descriptor *)
635 			buf);
636 		break;
637 	case GetHubStatus:
638 		/* no hub-wide feature/status flags */
639 		memset (buf, 0, 4);
640 		//cpu_to_le32s ((u32 *) buf);
641 		break;
642 	case GetPortStatus:
643 		if (!wIndex || wIndex > ports)
644 			goto error;
645 		wIndex--;
646 		status = 0;
647 		temp = ehci_readl(ehci, status_reg);
648 
649 		// wPortChange bits
650 		if (temp & PORT_CSC)
651 			status |= 1 << USB_PORT_FEAT_C_CONNECTION;
652 		if (temp & PORT_PEC)
653 			status |= 1 << USB_PORT_FEAT_C_ENABLE;
654 
655 		if ((temp & PORT_OCC) && !ignore_oc){
656 			status |= 1 << USB_PORT_FEAT_C_OVER_CURRENT;
657 
658 			/*
659 			 * Hubs should disable port power on over-current.
660 			 * However, not all EHCI implementations do this
661 			 * automatically, even if they _do_ support per-port
662 			 * power switching; they're allowed to just limit the
663 			 * current.  khubd will turn the power back on.
664 			 */
665 			if (HCS_PPC (ehci->hcs_params)){
666 				ehci_writel(ehci,
667 					temp & ~(PORT_RWC_BITS | PORT_POWER),
668 					status_reg);
669 			}
670 		}
671 
672 		/* whoever resumes must GetPortStatus to complete it!! */
673 		if (temp & PORT_RESUME) {
674 
675 			/* Remote Wakeup received? */
676 			if (!ehci->reset_done[wIndex]) {
677 				/* resume signaling for 20 msec */
678 				ehci->reset_done[wIndex] = jiffies
679 						+ msecs_to_jiffies(20);
680 				/* check the port again */
681 				mod_timer(&ehci_to_hcd(ehci)->rh_timer,
682 						ehci->reset_done[wIndex]);
683 			}
684 
685 			/* resume completed? */
686 			else if (time_after_eq(jiffies,
687 					ehci->reset_done[wIndex])) {
688 				status |= 1 << USB_PORT_FEAT_C_SUSPEND;
689 				ehci->reset_done[wIndex] = 0;
690 
691 				/* stop resume signaling */
692 				temp = ehci_readl(ehci, status_reg);
693 				ehci_writel(ehci,
694 					temp & ~(PORT_RWC_BITS | PORT_RESUME),
695 					status_reg);
696 				retval = handshake(ehci, status_reg,
697 					   PORT_RESUME, 0, 2000 /* 2msec */);
698 				if (retval != 0) {
699 					ehci_err(ehci,
700 						"port %d resume error %d\n",
701 						wIndex + 1, retval);
702 					goto error;
703 				}
704 				temp &= ~(PORT_SUSPEND|PORT_RESUME|(3<<10));
705 			}
706 		}
707 
708 		/* whoever resets must GetPortStatus to complete it!! */
709 		if ((temp & PORT_RESET)
710 				&& time_after_eq(jiffies,
711 					ehci->reset_done[wIndex])) {
712 			status |= 1 << USB_PORT_FEAT_C_RESET;
713 			ehci->reset_done [wIndex] = 0;
714 
715 			/* force reset to complete */
716 			ehci_writel(ehci, temp & ~(PORT_RWC_BITS | PORT_RESET),
717 					status_reg);
718 			/* REVISIT:  some hardware needs 550+ usec to clear
719 			 * this bit; seems too long to spin routinely...
720 			 */
721 			retval = handshake(ehci, status_reg,
722 					PORT_RESET, 0, 750);
723 			if (retval != 0) {
724 				ehci_err (ehci, "port %d reset error %d\n",
725 					wIndex + 1, retval);
726 				goto error;
727 			}
728 
729 			/* see what we found out */
730 			temp = check_reset_complete (ehci, wIndex, status_reg,
731 					ehci_readl(ehci, status_reg));
732 		}
733 
734 		/* transfer dedicated ports to the companion hc */
735 		if ((temp & PORT_CONNECT) &&
736 				test_bit(wIndex, &ehci->companion_ports)) {
737 			temp &= ~PORT_RWC_BITS;
738 			temp |= PORT_OWNER;
739 			ehci_writel(ehci, temp, status_reg);
740 			ehci_dbg(ehci, "port %d --> companion\n", wIndex + 1);
741 			temp = ehci_readl(ehci, status_reg);
742 		}
743 
744 		/*
745 		 * Even if OWNER is set, there's no harm letting khubd
746 		 * see the wPortStatus values (they should all be 0 except
747 		 * for PORT_POWER anyway).
748 		 */
749 
750 		if (temp & PORT_CONNECT) {
751 			status |= 1 << USB_PORT_FEAT_CONNECTION;
752 			// status may be from integrated TT
753 			status |= ehci_port_speed(ehci, temp);
754 		}
755 		if (temp & PORT_PE)
756 			status |= 1 << USB_PORT_FEAT_ENABLE;
757 		if (temp & (PORT_SUSPEND|PORT_RESUME))
758 			status |= 1 << USB_PORT_FEAT_SUSPEND;
759 		if (temp & PORT_OC)
760 			status |= 1 << USB_PORT_FEAT_OVER_CURRENT;
761 		if (temp & PORT_RESET)
762 			status |= 1 << USB_PORT_FEAT_RESET;
763 		if (temp & PORT_POWER)
764 			status |= 1 << USB_PORT_FEAT_POWER;
765 
766 #ifndef	EHCI_VERBOSE_DEBUG
767 	if (status & ~0xffff)	/* only if wPortChange is interesting */
768 #endif
769 		dbg_port (ehci, "GetStatus", wIndex + 1, temp);
770 		put_unaligned(cpu_to_le32 (status), (__le32 *) buf);
771 		break;
772 	case SetHubFeature:
773 		switch (wValue) {
774 		case C_HUB_LOCAL_POWER:
775 		case C_HUB_OVER_CURRENT:
776 			/* no hub-wide feature/status flags */
777 			break;
778 		default:
779 			goto error;
780 		}
781 		break;
782 	case SetPortFeature:
783 		selector = wIndex >> 8;
784 		wIndex &= 0xff;
785 		if (!wIndex || wIndex > ports)
786 			goto error;
787 		wIndex--;
788 		temp = ehci_readl(ehci, status_reg);
789 		if (temp & PORT_OWNER)
790 			break;
791 
792 		temp &= ~PORT_RWC_BITS;
793 		switch (wValue) {
794 		case USB_PORT_FEAT_SUSPEND:
795 			if (ehci->no_selective_suspend)
796 				break;
797 			if ((temp & PORT_PE) == 0
798 					|| (temp & PORT_RESET) != 0)
799 				goto error;
800 			if (device_may_wakeup(&hcd->self.root_hub->dev))
801 				temp |= PORT_WAKE_BITS;
802 			ehci_writel(ehci, temp | PORT_SUSPEND, status_reg);
803 			break;
804 		case USB_PORT_FEAT_POWER:
805 			if (HCS_PPC (ehci->hcs_params))
806 				ehci_writel(ehci, temp | PORT_POWER,
807 						status_reg);
808 			break;
809 		case USB_PORT_FEAT_RESET:
810 			if (temp & PORT_RESUME)
811 				goto error;
812 			/* line status bits may report this as low speed,
813 			 * which can be fine if this root hub has a
814 			 * transaction translator built in.
815 			 */
816 			if ((temp & (PORT_PE|PORT_CONNECT)) == PORT_CONNECT
817 					&& !ehci_is_TDI(ehci)
818 					&& PORT_USB11 (temp)) {
819 				ehci_dbg (ehci,
820 					"port %d low speed --> companion\n",
821 					wIndex + 1);
822 				temp |= PORT_OWNER;
823 			} else {
824 				ehci_vdbg (ehci, "port %d reset\n", wIndex + 1);
825 				temp |= PORT_RESET;
826 				temp &= ~PORT_PE;
827 
828 				/*
829 				 * caller must wait, then call GetPortStatus
830 				 * usb 2.0 spec says 50 ms resets on root
831 				 */
832 				ehci->reset_done [wIndex] = jiffies
833 						+ msecs_to_jiffies (50);
834 			}
835 			ehci_writel(ehci, temp, status_reg);
836 			break;
837 
838 		/* For downstream facing ports (these):  one hub port is put
839 		 * into test mode according to USB2 11.24.2.13, then the hub
840 		 * must be reset (which for root hub now means rmmod+modprobe,
841 		 * or else system reboot).  See EHCI 2.3.9 and 4.14 for info
842 		 * about the EHCI-specific stuff.
843 		 */
844 		case USB_PORT_FEAT_TEST:
845 			if (!selector || selector > 5)
846 				goto error;
847 			ehci_quiesce(ehci);
848 			ehci_halt(ehci);
849 			temp |= selector << 16;
850 			ehci_writel(ehci, temp, status_reg);
851 			break;
852 
853 		default:
854 			goto error;
855 		}
856 		ehci_readl(ehci, &ehci->regs->command);	/* unblock posted writes */
857 		break;
858 
859 	default:
860 error:
861 		/* "stall" on error */
862 		retval = -EPIPE;
863 	}
864 	spin_unlock_irqrestore (&ehci->lock, flags);
865 	return retval;
866 }
867