summaryrefslogtreecommitdiffstats
path: root/drivers/usb/host/pci-quirks.c
blob: 1d586d4f7b56d5e3a0c38cf793dfec8dbf2554af (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
/*
 * This file contains code to reset and initialize USB host controllers.
 * Some of it includes work-arounds for PCI hardware and BIOS quirks.
 * It may need to run early during booting -- before USB would normally
 * initialize -- to ensure that Linux doesn't use any legacy modes.
 *
 *  Copyright (c) 1999 Martin Mares <mj@ucw.cz>
 *  (and others)
 */

#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/acpi.h>
#include "pci-quirks.h"
#include "xhci-ext-caps.h"


#define UHCI_USBLEGSUP		0xc0		/* legacy support */
#define UHCI_USBCMD		0		/* command register */
#define UHCI_USBINTR		4		/* interrupt register */
#define UHCI_USBLEGSUP_RWC	0x8f00		/* the R/WC bits */
#define UHCI_USBLEGSUP_RO	0x5040		/* R/O and reserved bits */
#define UHCI_USBCMD_RUN		0x0001		/* RUN/STOP bit */
#define UHCI_USBCMD_HCRESET	0x0002		/* Host Controller reset */
#define UHCI_USBCMD_EGSM	0x0008		/* Global Suspend Mode */
#define UHCI_USBCMD_CONFIGURE	0x0040		/* Config Flag */
#define UHCI_USBINTR_RESUME	0x0002		/* Resume interrupt enable */

#define OHCI_CONTROL		0x04
#define OHCI_CMDSTATUS		0x08
#define OHCI_INTRSTATUS		0x0c
#define OHCI_INTRENABLE		0x10
#define OHCI_INTRDISABLE	0x14
#define OHCI_OCR		(1 << 3)	/* ownership change request */
#define OHCI_CTRL_RWC		(1 << 9)	/* remote wakeup connected */
#define OHCI_CTRL_IR		(1 << 8)	/* interrupt routing */
#define OHCI_INTR_OC		(1 << 30)	/* ownership change */

#define EHCI_HCC_PARAMS		0x08		/* extended capabilities */
#define EHCI_USBCMD		0		/* command register */
#define EHCI_USBCMD_RUN		(1 << 0)	/* RUN/STOP bit */
#define EHCI_USBSTS		4		/* status register */
#define EHCI_USBSTS_HALTED	(1 << 12)	/* HCHalted bit */
#define EHCI_USBINTR		8		/* interrupt register */
#define EHCI_CONFIGFLAG		0x40		/* configured flag register */
#define EHCI_USBLEGSUP		0		/* legacy support register */
#define EHCI_USBLEGSUP_BIOS	(1 << 16)	/* BIOS semaphore */
#define EHCI_USBLEGSUP_OS	(1 << 24)	/* OS semaphore */
#define EHCI_USBLEGCTLSTS	4		/* legacy control/status */
#define EHCI_USBLEGCTLSTS_SOOE	(1 << 13)	/* SMI on ownership change */

/* AMD quirk use */
#define	AB_REG_BAR_LOW		0xe0
#define	AB_REG_BAR_HIGH		0xe1
#define	AB_REG_BAR_SB700	0xf0
#define	AB_INDX(addr)		((addr) + 0x00)
#define	AB_DATA(addr)		((addr) + 0x04)
#define	AX_INDXC		0x30
#define	AX_DATAC		0x34

#define	NB_PCIE_INDX_ADDR	0xe0
#define	NB_PCIE_INDX_DATA	0xe4
#define	PCIE_P_CNTL		0x10040
#define	BIF_NB			0x10002
#define	NB_PIF0_PWRDOWN_0	0x01100012
#define	NB_PIF0_PWRDOWN_1	0x01100013

static struct amd_chipset_info {
	struct pci_dev	*nb_dev;
	struct pci_dev	*smbus_dev;
	int nb_type;
	int sb_type;
	int isoc_reqs;
	int probe_count;
	int probe_result;
} amd_chipset;

static DEFINE_SPINLOCK(amd_lock);

int usb_amd_find_chipset_info(void)
{
	u8 rev = 0;
	unsigned long flags;

	spin_lock_irqsave(&amd_lock, flags);

	amd_chipset.probe_count++;
	/* probe only once */
	if (amd_chipset.probe_count > 1) {
		spin_unlock_irqrestore(&amd_lock, flags);
		return amd_chipset.probe_result;
	}

	amd_chipset.smbus_dev = pci_get_device(PCI_VENDOR_ID_ATI, 0x4385, NULL);
	if (amd_chipset.smbus_dev) {
		rev = amd_chipset.smbus_dev->revision;
		if (rev >= 0x40)
			amd_chipset.sb_type = 1;
		else if (rev >= 0x30 && rev <= 0x3b)
			amd_chipset.sb_type = 3;
	} else {
		amd_chipset.smbus_dev = pci_get_device(PCI_VENDOR_ID_AMD,
							0x780b, NULL);
		if (!amd_chipset.smbus_dev) {
			spin_unlock_irqrestore(&amd_lock, flags);
			return 0;
		}
		rev = amd_chipset.smbus_dev->revision;
		if (rev >= 0x11 && rev <= 0x18)
			amd_chipset.sb_type = 2;
	}

	if (amd_chipset.sb_type == 0) {
		if (amd_chipset.smbus_dev) {
			pci_dev_put(amd_chipset.smbus_dev);
			amd_chipset.smbus_dev = NULL;
		}
		spin_unlock_irqrestore(&amd_lock, flags);
		return 0;
	}

	amd_chipset.nb_dev = pci_get_device(PCI_VENDOR_ID_AMD, 0x9601, NULL);
	if (amd_chipset.nb_dev) {
		amd_chipset.nb_type = 1;
	} else {
		amd_chipset.nb_dev = pci_get_device(PCI_VENDOR_ID_AMD,
							0x1510, NULL);
		if (amd_chipset.nb_dev) {
			amd_chipset.nb_type = 2;
		} else  {
			amd_chipset.nb_dev = pci_get_device(PCI_VENDOR_ID_AMD,
								0x9600, NULL);
			if (amd_chipset.nb_dev)
				amd_chipset.nb_type = 3;
		}
	}

	amd_chipset.probe_result = 1;
	printk(KERN_DEBUG "QUIRK: Enable AMD PLL fix\n");

	spin_unlock_irqrestore(&amd_lock, flags);
	return amd_chipset.probe_result;
}
EXPORT_SYMBOL_GPL(usb_amd_find_chipset_info);

/*
 * The hardware normally enables the A-link power management feature, which
 * lets the system lower the power consumption in idle states.
 *
 * This USB quirk prevents the link going into that lower power state
 * during isochronous transfers.
 *
 * Without this quirk, isochronous stream on OHCI/EHCI/xHCI controllers of
 * some AMD platforms may stutter or have breaks occasionally.
 */
static void usb_amd_quirk_pll(int disable)
{
	u32 addr, addr_low, addr_high, val;
	u32 bit = disable ? 0 : 1;
	unsigned long flags;

	spin_lock_irqsave(&amd_lock, flags);

	if (disable) {
		amd_chipset.isoc_reqs++;
		if (amd_chipset.isoc_reqs > 1) {
			spin_unlock_irqrestore(&amd_lock, flags);
			return;
		}
	} else {
		amd_chipset.isoc_reqs--;
		if (amd_chipset.isoc_reqs > 0) {
			spin_unlock_irqrestore(&amd_lock, flags);
			return;
		}
	}

	if (amd_chipset.sb_type == 1 || amd_chipset.sb_type == 2) {
		outb_p(AB_REG_BAR_LOW, 0xcd6);
		addr_low = inb_p(0xcd7);
		outb_p(AB_REG_BAR_HIGH, 0xcd6);
		addr_high = inb_p(0xcd7);
		addr = addr_high << 8 | addr_low;

		outl_p(0x30, AB_INDX(addr));
		outl_p(0x40, AB_DATA(addr));
		outl_p(0x34, AB_INDX(addr));
		val = inl_p(AB_DATA(addr));
	} else if (amd_chipset.sb_type == 3) {
		pci_read_config_dword(amd_chipset.smbus_dev,
					AB_REG_BAR_SB700, &addr);
		outl(AX_INDXC, AB_INDX(addr));
		outl(0x40, AB_DATA(addr));
		outl(AX_DATAC, AB_INDX(addr));
		val = inl(AB_DATA(addr));
	} else {
		spin_unlock_irqrestore(&amd_lock, flags);
		return;
	}

	if (disable) {
		val &= ~0x08;
		val |= (1 << 4) | (1 << 9);
	} else {
		val |= 0x08;
		val &= ~((1 << 4) | (1 << 9));
	}
	outl_p(val, AB_DATA(addr));

	if (!amd_chipset.nb_dev) {
		spin_unlock_irqrestore(&amd_lock, flags);
		return;
	}

	if (amd_chipset.nb_type == 1 || amd_chipset.nb_type == 3) {
		addr = PCIE_P_CNTL;
		pci_write_config_dword(amd_chipset.nb_dev,
					NB_PCIE_INDX_ADDR, addr);
		pci_read_config_dword(amd_chipset.nb_dev,
					NB_PCIE_INDX_DATA, &val);

		val &= ~(1 | (1 << 3) | (1 << 4) | (1 << 9) | (1 << 12));
		val |= bit | (bit << 3) | (bit << 12);
		val |= ((!bit) << 4) | ((!bit) << 9);
		pci_write_config_dword(amd_chipset.nb_dev,
					NB_PCIE_INDX_DATA, val);

		addr = BIF_NB;
		pci_write_config_dword(amd_chipset.nb_dev,
					NB_PCIE_INDX_ADDR, addr);
		pci_read_config_dword(amd_chipset.nb_dev,
					NB_PCIE_INDX_DATA, &val);
		val &= ~(1 << 8);
		val |= bit << 8;

		pci_write_config_dword(amd_chipset.nb_dev,
					NB_PCIE_INDX_DATA, val);
	} else if (amd_chipset.nb_type == 2) {
		addr = NB_PIF0_PWRDOWN_0;
		pci_write_config_dword(amd_chipset.nb_dev,
					NB_PCIE_INDX_ADDR, addr);
		pci_read_config_dword(amd_chipset.nb_dev,
					NB_PCIE_INDX_DATA, &val);
		if (disable)
			val &= ~(0x3f << 7);
		else
			val |= 0x3f << 7;

		pci_write_config_dword(amd_chipset.nb_dev,
					NB_PCIE_INDX_DATA, val);

		addr = NB_PIF0_PWRDOWN_1;
		pci_write_config_dword(amd_chipset.nb_dev,
					NB_PCIE_INDX_ADDR, addr);
		pci_read_config_dword(amd_chipset.nb_dev,
					NB_PCIE_INDX_DATA, &val);
		if (disable)
			val &= ~(0x3f << 7);
		else
			val |= 0x3f << 7;

		pci_write_config_dword(amd_chipset.nb_dev,
					NB_PCIE_INDX_DATA, val);
	}

	spin_unlock_irqrestore(&amd_lock, flags);
	return;
}

void usb_amd_quirk_pll_disable(void)
{
	usb_amd_quirk_pll(1);
}
EXPORT_SYMBOL_GPL(usb_amd_quirk_pll_disable);

void usb_amd_quirk_pll_enable(void)
{
	usb_amd_quirk_pll(0);
}
EXPORT_SYMBOL_GPL(usb_amd_quirk_pll_enable);

void usb_amd_dev_put(void)
{
	unsigned long flags;

	spin_lock_irqsave(&amd_lock, flags);

	amd_chipset.probe_count--;
	if (amd_chipset.probe_count > 0) {
		spin_unlock_irqrestore(&amd_lock, flags);
		return;
	}

	if (amd_chipset.nb_dev) {
		pci_dev_put(amd_chipset.nb_dev);
		amd_chipset.nb_dev = NULL;
	}
	if (amd_chipset.smbus_dev) {
		pci_dev_put(amd_chipset.smbus_dev);
		amd_chipset.smbus_dev = NULL;
	}
	amd_chipset.nb_type = 0;
	amd_chipset.sb_type = 0;
	amd_chipset.isoc_reqs = 0;
	amd_chipset.probe_result = 0;

	spin_unlock_irqrestore(&amd_lock, flags);
}
EXPORT_SYMBOL_GPL(usb_amd_dev_put);

/*
 * Make sure the controller is completely inactive, unable to
 * generate interrupts or do DMA.
 */
void uhci_reset_hc(struct pci_dev *pdev, unsigned long base)
{
	/* Turn off PIRQ enable and SMI enable.  (This also turns off the
	 * BIOS's USB Legacy Support.)  Turn off all the R/WC bits too.
	 */
	pci_write_config_word(pdev, UHCI_USBLEGSUP, UHCI_USBLEGSUP_RWC);

	/* Reset the HC - this will force us to get a
	 * new notification of any already connected
	 * ports due to the virtual disconnect that it
	 * implies.
	 */
	outw(UHCI_USBCMD_HCRESET, base + UHCI_USBCMD);
	mb();
	udelay(5);
	if (inw(base + UHCI_USBCMD) & UHCI_USBCMD_HCRESET)
		dev_warn(&pdev->dev, "HCRESET not completed yet!\n");

	/* Just to be safe, disable interrupt requests and
	 * make sure the controller is stopped.
	 */
	outw(0, base + UHCI_USBINTR);
	outw(0, base + UHCI_USBCMD);
}
EXPORT_SYMBOL_GPL(uhci_reset_hc);

/*
 * Initialize a controller that was newly discovered or has just been
 * resumed.  In either case we can't be sure of its previous state.
 *
 * Returns: 1 if the controller was reset, 0 otherwise.
 */
int uhci_check_and_reset_hc(struct pci_dev *pdev, unsigned long base)
{
	u16 legsup;
	unsigned int cmd, intr;

	/*
	 * When restarting a suspended controller, we expect all the
	 * settings to be the same as we left them:
	 *
	 *	PIRQ and SMI disabled, no R/W bits set in USBLEGSUP;
	 *	Controller is stopped and configured with EGSM set;
	 *	No interrupts enabled except possibly Resume Detect.
	 *
	 * If any of these conditions are violated we do a complete reset.
	 */
	pci_read_config_word(pdev, UHCI_USBLEGSUP, &legsup);
	if (legsup & ~(UHCI_USBLEGSUP_RO | UHCI_USBLEGSUP_RWC)) {
		dev_dbg(&pdev->dev, "%s: legsup = 0x%04x\n",
				__func__, legsup);
		goto reset_needed;
	}

	cmd = inw(base + UHCI_USBCMD);
	if ((cmd & UHCI_USBCMD_RUN) || !(cmd & UHCI_USBCMD_CONFIGURE) ||
			!(cmd & UHCI_USBCMD_EGSM)) {
		dev_dbg(&pdev->dev, "%s: cmd = 0x%04x\n",
				__func__, cmd);
		goto reset_needed;
	}

	intr = inw(base + UHCI_USBINTR);
	if (intr & (~UHCI_USBINTR_RESUME)) {
		dev_dbg(&pdev->dev, "%s: intr = 0x%04x\n",
				__func__, intr);
		goto reset_needed;
	}
	return 0;

reset_needed:
	dev_dbg(&pdev->dev, "Performing full reset\n");
	uhci_reset_hc(pdev, base);
	return 1;
}
EXPORT_SYMBOL_GPL(uhci_check_and_reset_hc);

static inline int io_type_enabled(struct pci_dev *pdev, unsigned int mask)
{
	u16 cmd;
	return !pci_read_config_word(pdev, PCI_COMMAND, &cmd) && (cmd & mask);
}

#define pio_enabled(dev) io_type_enabled(dev, PCI_COMMAND_IO)
#define mmio_enabled(dev) io_type_enabled(dev, PCI_COMMAND_MEMORY)

static void __devinit quirk_usb_handoff_uhci(struct pci_dev *pdev)
{
	unsigned long base = 0;
	int i;

	if (!pio_enabled(pdev))
		return;

	for (i = 0; i < PCI_ROM_RESOURCE; i++)
		if ((pci_resource_flags(pdev, i) & IORESOURCE_IO)) {
			base = pci_resource_start(pdev, i);
			break;
		}

	if (base)
		uhci_check_and_reset_hc(pdev, base);
}

static int __devinit mmio_resource_enabled(struct pci_dev *pdev, int idx)
{
	return pci_resource_start(pdev, idx) && mmio_enabled(pdev);
}

static void __devinit quirk_usb_handoff_ohci(struct pci_dev *pdev)
{
	void __iomem *base;
	u32 control;

	if (!mmio_resource_enabled(pdev, 0))
		return;

	base = pci_ioremap_bar(pdev, 0);
	if (base == NULL)
		return;

	control = readl(base + OHCI_CONTROL);

/* On PA-RISC, PDC can leave IR set incorrectly; ignore it there. */
#ifdef __hppa__
#define	OHCI_CTRL_MASK		(OHCI_CTRL_RWC | OHCI_CTRL_IR)
#else
#define	OHCI_CTRL_MASK		OHCI_CTRL_RWC

	if (control & OHCI_CTRL_IR) {
		int wait_time = 500; /* arbitrary; 5 seconds */
		writel(OHCI_INTR_OC, base + OHCI_INTRENABLE);
		writel(OHCI_OCR, base + OHCI_CMDSTATUS);
		while (wait_time > 0 &&
				readl(base + OHCI_CONTROL) & OHCI_CTRL_IR) {
			wait_time -= 10;
			msleep(10);
		}
		if (wait_time <= 0)
			dev_warn(&pdev->dev, "OHCI: BIOS handoff failed"
					" (BIOS bug?) %08x\n",
					readl(base + OHCI_CONTROL));
	}
#endif

	/* reset controller, preserving RWC (and possibly IR) */
	writel(control & OHCI_CTRL_MASK, base + OHCI_CONTROL);

	/*
	 * disable interrupts
	 */
	writel(~(u32)0, base + OHCI_INTRDISABLE);
	writel(~(u32)0, base + OHCI_INTRSTATUS);

	iounmap(base);
}

static void __devinit quirk_usb_disable_ehci(struct pci_dev *pdev)
{
	int wait_time, delta;
	void __iomem *base, *op_reg_base;
	u32	hcc_params, val;
	u8	offset, cap_length;
	int	count = 256/4;
	int	tried_handoff = 0;

	if (!mmio_resource_enabled(pdev, 0))
		return;

	base = pci_ioremap_bar(pdev, 0);
	if (base == NULL)
		return;

	cap_length = readb(base);
	op_reg_base = base + cap_length;

	/* EHCI 0.96 and later may have "extended capabilities"
	 * spec section 5.1 explains the bios handoff, e.g. for
	 * booting from USB disk or using a usb keyboard
	 */
	hcc_params = readl(base + EHCI_HCC_PARAMS);
	offset = (hcc_params >> 8) & 0xff;
	while (offset && --count) {
		u32		cap;
		int		msec;

		pci_read_config_dword(pdev, offset, &cap);
		switch (cap & 0xff) {
		case 1:			/* BIOS/SMM/... handoff support */
			if ((cap & EHCI_USBLEGSUP_BIOS)) {
				dev_dbg(&pdev->dev, "EHCI: BIOS handoff\n");

#if 0
/* aleksey_gorelov@phoenix.com reports that some systems need SMI forced on,
 * but that seems dubious in general (the BIOS left it off intentionally)
 * and is known to prevent some systems from booting.  so we won't do this
 * unless maybe we can determine when we're on a system that needs SMI forced.
 */
				/* BIOS workaround (?): be sure the
				 * pre-Linux code receives the SMI
				 */
				pci_read_config_dword(pdev,
						offset + EHCI_USBLEGCTLSTS,
						&val);
				pci_write_config_dword(pdev,
						offset + EHCI_USBLEGCTLSTS,
						val | EHCI_USBLEGCTLSTS_SOOE);
#endif

				/* some systems get upset if this semaphore is
				 * set for any other reason than forcing a BIOS
				 * handoff..
				 */
				pci_write_config_byte(pdev, offset + 3, 1);
			}

			/* if boot firmware now owns EHCI, spin till
			 * it hands it over.
			 */
			msec = 1000;
			while ((cap & EHCI_USBLEGSUP_BIOS) && (msec > 0)) {
				tried_handoff = 1;
				msleep(10);
				msec -= 10;
				pci_read_config_dword(pdev, offset, &cap);
			}

			if (cap & EHCI_USBLEGSUP_BIOS) {
				/* well, possibly buggy BIOS... try to shut
				 * it down, and hope nothing goes too wrong
				 */
				dev_warn(&pdev->dev, "EHCI: BIOS handoff failed"
						" (BIOS bug?) %08x\n", cap);
				pci_write_config_byte(pdev, offset + 2, 0);
			}

			/* just in case, always disable EHCI SMIs */
			pci_write_config_dword(pdev,
					offset + EHCI_USBLEGCTLSTS,
					0);

			/* If the BIOS ever owned the controller then we
			 * can't expect any power sessions to remain intact.
			 */
			if (tried_handoff)
				writel(0, op_reg_base + EHCI_CONFIGFLAG);
			break;
		case 0:			/* illegal reserved capability */
			cap = 0;
			/* FALLTHROUGH */
		default:
			dev_warn(&pdev->dev, "EHCI: unrecognized capability "
					"%02x\n", cap & 0xff);
			break;
		}
		offset = (cap >> 8) & 0xff;
	}
	if (!count)
		dev_printk(KERN_DEBUG, &pdev->dev, "EHCI: capability loop?\n");

	/*
	 * halt EHCI & disable its interrupts in any case
	 */
	val = readl(op_reg_base + EHCI_USBSTS);
	if ((val & EHCI_USBSTS_HALTED) == 0) {
		val = readl(op_reg_base + EHCI_USBCMD);
		val &= ~EHCI_USBCMD_RUN;
		writel(val, op_reg_base + EHCI_USBCMD);

		wait_time = 2000;
		delta = 100;
		do {
			writel(0x3f, op_reg_base + EHCI_USBSTS);
			udelay(delta);
			wait_time -= delta;
			val = readl(op_reg_base + EHCI_USBSTS);
			if ((val == ~(u32)0) || (val & EHCI_USBSTS_HALTED)) {
				break;
			}
		} while (wait_time > 0);
	}
	writel(0, op_reg_base + EHCI_USBINTR);
	writel(0x3f, op_reg_base + EHCI_USBSTS);

	iounmap(base);
}

/*
 * handshake - spin reading a register until handshake completes
 * @ptr: address of hc register to be read
 * @mask: bits to look at in result of read
 * @done: value of those bits when handshake succeeds
 * @wait_usec: timeout in microseconds
 * @delay_usec: delay in microseconds to wait between polling
 *
 * Polls a register every delay_usec microseconds.
 * Returns 0 when the mask bits have the value done.
 * Returns -ETIMEDOUT if this condition is not true after
 * wait_usec microseconds have passed.
 */
static int handshake(void __iomem *ptr, u32 mask, u32 done,
		int wait_usec, int delay_usec)
{
	u32	result;

	do {
		result = readl(ptr);
		result &= mask;
		if (result == done)
			return 0;
		udelay(delay_usec);
		wait_usec -= delay_usec;
	} while (wait_usec > 0);
	return -ETIMEDOUT;
}

/**
 * PCI Quirks for xHCI.
 *
 * Takes care of the handoff between the Pre-OS (i.e. BIOS) and the OS.
 * It signals to the BIOS that the OS wants control of the host controller,
 * and then waits 5 seconds for the BIOS to hand over control.
 * If we timeout, assume the BIOS is broken and take control anyway.
 */
static void __devinit quirk_usb_handoff_xhci(struct pci_dev *pdev)
{
	void __iomem *base;
	int ext_cap_offset;
	void __iomem *op_reg_base;
	u32 val;
	int timeout;

	if (!mmio_resource_enabled(pdev, 0))
		return;

	base = ioremap_nocache(pci_resource_start(pdev, 0),
				pci_resource_len(pdev, 0));
	if (base == NULL)
		return;

	/*
	 * Find the Legacy Support Capability register -
	 * this is optional for xHCI host controllers.
	 */
	ext_cap_offset = xhci_find_next_cap_offset(base, XHCI_HCC_PARAMS_OFFSET);
	do {
		if (!ext_cap_offset)
			/* We've reached the end of the extended capabilities */
			goto hc_init;
		val = readl(base + ext_cap_offset);
		if (XHCI_EXT_CAPS_ID(val) == XHCI_EXT_CAPS_LEGACY)
			break;
		ext_cap_offset = xhci_find_next_cap_offset(base, ext_cap_offset);
	} while (1);

	/* If the BIOS owns the HC, signal that the OS wants it, and wait */
	if (val & XHCI_HC_BIOS_OWNED) {
		writel(val & XHCI_HC_OS_OWNED, base + ext_cap_offset);

		/* Wait for 5 seconds with 10 microsecond polling interval */
		timeout = handshake(base + ext_cap_offset, XHCI_HC_BIOS_OWNED,
				0, 5000, 10);

		/* Assume a buggy BIOS and take HC ownership anyway */
		if (timeout) {
			dev_warn(&pdev->dev, "xHCI BIOS handoff failed"
					" (BIOS bug ?) %08x\n", val);
			writel(val & ~XHCI_HC_BIOS_OWNED, base + ext_cap_offset);
		}
	}

	/* Disable any BIOS SMIs */
	writel(XHCI_LEGACY_DISABLE_SMI,
			base + ext_cap_offset + XHCI_LEGACY_CONTROL_OFFSET);

hc_init:
	op_reg_base = base + XHCI_HC_LENGTH(readl(base));

	/* Wait for the host controller to be ready before writing any
	 * operational or runtime registers.  Wait 5 seconds and no more.
	 */
	timeout = handshake(op_reg_base + XHCI_STS_OFFSET, XHCI_STS_CNR, 0,
			5000, 10);
	/* Assume a buggy HC and start HC initialization anyway */
	if (timeout) {
		val = readl(op_reg_base + XHCI_STS_OFFSET);
		dev_warn(&pdev->dev,
				"xHCI HW not ready after 5 sec (HC bug?) "
				"status = 0x%x\n", val);
	}

	/* Send the halt and disable interrupts command */
	val = readl(op_reg_base + XHCI_CMD_OFFSET);
	val &= ~(XHCI_CMD_RUN | XHCI_IRQS);
	writel(val, op_reg_base + XHCI_CMD_OFFSET);

	/* Wait for the HC to halt - poll every 125 usec (one microframe). */
	timeout = handshake(op_reg_base + XHCI_STS_OFFSET, XHCI_STS_HALT, 1,
			XHCI_MAX_HALT_USEC, 125);
	if (timeout) {
		val = readl(op_reg_base + XHCI_STS_OFFSET);
		dev_warn(&pdev->dev,
				"xHCI HW did not halt within %d usec "
				"status = 0x%x\n", XHCI_MAX_HALT_USEC, val);
	}

	iounmap(base);
}

static void __devinit quirk_usb_early_handoff(struct pci_dev *pdev)
{
	if (pdev->class == PCI_CLASS_SERIAL_USB_UHCI)
		quirk_usb_handoff_uhci(pdev);
	else if (pdev->class == PCI_CLASS_SERIAL_USB_OHCI)
		quirk_usb_handoff_ohci(pdev);
	else if (pdev->class == PCI_CLASS_SERIAL_USB_EHCI)
		quirk_usb_disable_ehci(pdev);
	else if (pdev->class == PCI_CLASS_SERIAL_USB_XHCI)
		quirk_usb_handoff_xhci(pdev);
}
DECLARE_PCI_FIXUP_FINAL(PCI_ANY_ID, PCI_ANY_ID, quirk_usb_early_handoff);