aboutsummaryrefslogtreecommitdiff
path: root/drivers/usb/host/pci-quirks.c
blob: 32dada8c8b4f31e639227d120203482fe487d229 (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
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
/*
 * 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/export.h>
#include <linux/acpi.h>
#include <linux/dmi.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_FMINTERVAL		0x34
#define OHCI_HCFS		(3 << 6)	/* hc functional state */
#define OHCI_HCR		(1 << 0)	/* host controller reset */
#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

#define USB_INTEL_XUSB2PR      0xD0
#define USB_INTEL_USB3_PSSEN   0xD8

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;
	struct amd_chipset_info info;
	int ret;

	spin_lock_irqsave(&amd_lock, flags);

	/* probe only once */
	if (amd_chipset.probe_count > 0) {
		amd_chipset.probe_count++;
		spin_unlock_irqrestore(&amd_lock, flags);
		return amd_chipset.probe_result;
	}
	memset(&info, 0, sizeof(info));
	spin_unlock_irqrestore(&amd_lock, flags);

	info.smbus_dev = pci_get_device(PCI_VENDOR_ID_ATI, 0x4385, NULL);
	if (info.smbus_dev) {
		rev = info.smbus_dev->revision;
		if (rev >= 0x40)
			info.sb_type = 1;
		else if (rev >= 0x30 && rev <= 0x3b)
			info.sb_type = 3;
	} else {
		info.smbus_dev = pci_get_device(PCI_VENDOR_ID_AMD,
						0x780b, NULL);
		if (!info.smbus_dev) {
			ret = 0;
			goto commit;
		}

		rev = info.smbus_dev->revision;
		if (rev >= 0x11 && rev <= 0x18)
			info.sb_type = 2;
	}

	if (info.sb_type == 0) {
		if (info.smbus_dev) {
			pci_dev_put(info.smbus_dev);
			info.smbus_dev = NULL;
		}
		ret = 0;
		goto commit;
	}

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

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

commit:

	spin_lock_irqsave(&amd_lock, flags);
	if (amd_chipset.probe_count > 0) {
		/* race - someone else was faster - drop devices */

		/* Mark that we where here */
		amd_chipset.probe_count++;
		ret = amd_chipset.probe_result;

		spin_unlock_irqrestore(&amd_lock, flags);

		if (info.nb_dev)
			pci_dev_put(info.nb_dev);
		if (info.smbus_dev)
			pci_dev_put(info.smbus_dev);

	} else {
		/* no race - commit the result */
		info.probe_count++;
		amd_chipset = info;
		spin_unlock_irqrestore(&amd_lock, flags);
	}

	return ret;
}
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)
{
	struct pci_dev *nb, *smbus;
	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;
	}

	/* save them to pci_dev_put outside of spinlock */
	nb    = amd_chipset.nb_dev;
	smbus = amd_chipset.smbus_dev;

	amd_chipset.nb_dev = NULL;
	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);

	if (nb)
		pci_dev_put(nb);
	if (smbus)
		pci_dev_put(smbus);
}
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;
	u32 fminterval;
	int cnt;

	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

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

	/* Reset the USB bus, if the controller isn't already in RESET */
	if (control & OHCI_HCFS) {
		/* Go into RESET, preserving RWC (and possibly IR) */
		writel(control & OHCI_CTRL_MASK, base + OHCI_CONTROL);
		readl(base + OHCI_CONTROL);

		/* drive bus reset for at least 50 ms (7.1.7.5) */
		msleep(50);
	}

	/* software reset of the controller, preserving HcFmInterval */
	fminterval = readl(base + OHCI_FMINTERVAL);
	writel(OHCI_HCR, base + OHCI_CMDSTATUS);

	/* reset requires max 10 us delay */
	for (cnt = 30; cnt > 0; --cnt) {	/* ... allow extra time */
		if ((readl(base + OHCI_CMDSTATUS) & OHCI_HCR) == 0)
			break;
		udelay(1);
	}
	writel(fminterval, base + OHCI_FMINTERVAL);

	/* Now the controller is safely in SUSPEND and nothing can wake it up */
	iounmap(base);
}

static const struct dmi_system_id __devinitconst ehci_dmi_nohandoff_table[] = {
	{
		/*  Pegatron Lucid (ExoPC) */
		.matches = {
			DMI_MATCH(DMI_BOARD_NAME, "EXOPG06411"),
			DMI_MATCH(DMI_BIOS_VERSION, "Lucid-CE-133"),
		},
	},
	{
		/*  Pegatron Lucid (Ordissimo AIRIS) */
		.matches = {
			DMI_MATCH(DMI_BOARD_NAME, "M11JB"),
			DMI_MATCH(DMI_BIOS_VERSION, "Lucid-GE-133"),
		},
	},
	{ }
};

static void __devinit ehci_bios_handoff(struct pci_dev *pdev,
					void __iomem *op_reg_base,
					u32 cap, u8 offset)
{
	int try_handoff = 1, tried_handoff = 0;

	/* The Pegatron Lucid tablet sporadically waits for 98 seconds trying
	 * the handoff on its unused controller.  Skip it. */
	if (pdev->vendor == 0x8086 && pdev->device == 0x283a) {
		if (dmi_check_system(ehci_dmi_nohandoff_table))
			try_handoff = 0;
	}

	if (try_handoff && (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. */
	if (try_handoff) {
		int 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
		 */
		if (try_handoff)
			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);
}

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

	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) {
		pci_read_config_dword(pdev, offset, &cap);

		switch (cap & 0xff) {
		case 1:
			ehci_bios_handoff(pdev, op_reg_base, cap, offset);
			break;
		case 0: /* Illegal reserved cap, set cap=0 so we exit */
			cap = 0; /* then fallthrough... */
		default:
			dev_warn(&pdev->dev, "EHCI: unrecognized capability "
				 "%02x\n", cap & 0xff);
		}
		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;
		do {
			writel(0x3f, op_reg_base + EHCI_USBSTS);
			udelay(100);
			wait_time -= 100;
			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;
}

bool usb_is_intel_switchable_xhci(struct pci_dev *pdev)
{
	return pdev->class == PCI_CLASS_SERIAL_USB_XHCI &&
		pdev->vendor == PCI_VENDOR_ID_INTEL &&
		pdev->device == PCI_DEVICE_ID_INTEL_PANTHERPOINT_XHCI;
}
EXPORT_SYMBOL_GPL(usb_is_intel_switchable_xhci);

/*
 * Intel's Panther Point chipset has two host controllers (EHCI and xHCI) that
 * share some number of ports.  These ports can be switched between either
 * controller.  Not all of the ports under the EHCI host controller may be
 * switchable.
 *
 * The ports should be switched over to xHCI before PCI probes for any device
 * start.  This avoids active devices under EHCI being disconnected during the
 * port switchover, which could cause loss of data on USB storage devices, or
 * failed boot when the root file system is on a USB mass storage device and is
 * enumerated under EHCI first.
 *
 * We write into the xHC's PCI configuration space in some Intel-specific
 * registers to switch the ports over.  The USB 3.0 terminations and the USB
 * 2.0 data wires are switched separately.  We want to enable the SuperSpeed
 * terminations before switching the USB 2.0 wires over, so that USB 3.0
 * devices connect at SuperSpeed, rather than at USB 2.0 speeds.
 */
void usb_enable_xhci_ports(struct pci_dev *xhci_pdev)
{
	u32		ports_available;

	ports_available = 0xffffffff;
	/* Write USB3_PSSEN, the USB 3.0 Port SuperSpeed Enable
	 * Register, to turn on SuperSpeed terminations for all
	 * available ports.
	 */
	pci_write_config_dword(xhci_pdev, USB_INTEL_USB3_PSSEN,
			cpu_to_le32(ports_available));

	pci_read_config_dword(xhci_pdev, USB_INTEL_USB3_PSSEN,
			&ports_available);
	dev_dbg(&xhci_pdev->dev, "USB 3.0 ports that are now enabled "
			"under xHCI: 0x%x\n", ports_available);

	ports_available = 0xffffffff;
	/* Write XUSB2PR, the xHC USB 2.0 Port Routing Register, to
	 * switch the USB 2.0 power and data lines over to the xHCI
	 * host.
	 */
	pci_write_config_dword(xhci_pdev, USB_INTEL_XUSB2PR,
			cpu_to_le32(ports_available));

	pci_read_config_dword(xhci_pdev, USB_INTEL_XUSB2PR,
			&ports_available);
	dev_dbg(&xhci_pdev->dev, "USB 2.0 ports that are now switched over "
			"to xHCI: 0x%x\n", ports_available);
}
EXPORT_SYMBOL_GPL(usb_enable_xhci_ports);

/**
 * 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);
		}
	}

	val = readl(base + ext_cap_offset + XHCI_LEGACY_CONTROL_OFFSET);
	/* Mask off (turn off) any enabled SMIs */
	val &= XHCI_LEGACY_DISABLE_SMI;
	/* Mask all SMI events bits, RW1C */
	val |= XHCI_LEGACY_SMI_EVENTS;
	/* Disable any BIOS SMIs and clear all SMI events*/
	writel(val, base + ext_cap_offset + XHCI_LEGACY_CONTROL_OFFSET);

	if (usb_is_intel_switchable_xhci(pdev))
		usb_enable_xhci_ports(pdev);
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)
{
	/* Skip Netlogic mips SoC's internal PCI USB controller.
	 * This device does not need/support EHCI/OHCI handoff
	 */
	if (pdev->vendor == 0x184e)	/* vendor Netlogic */
		return;
	if (pdev->class != PCI_CLASS_SERIAL_USB_UHCI &&
			pdev->class != PCI_CLASS_SERIAL_USB_OHCI &&
			pdev->class != PCI_CLASS_SERIAL_USB_EHCI &&
			pdev->class != PCI_CLASS_SERIAL_USB_XHCI)
		return;

	if (pci_enable_device(pdev) < 0) {
		dev_warn(&pdev->dev, "Can't enable PCI device, "
				"BIOS handoff failed.\n");
		return;
	}
	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);
	pci_disable_device(pdev);
}
DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_ANY_ID, PCI_ANY_ID,
			PCI_CLASS_SERIAL_USB, 8, quirk_usb_early_handoff);