xref: /linux/drivers/usb/host/pci-quirks.c (revision 60e13231561b3a4c5269bfa1ef6c0569ad6f28ec)
1 /*
2  * This file contains code to reset and initialize USB host controllers.
3  * Some of it includes work-arounds for PCI hardware and BIOS quirks.
4  * It may need to run early during booting -- before USB would normally
5  * initialize -- to ensure that Linux doesn't use any legacy modes.
6  *
7  *  Copyright (c) 1999 Martin Mares <mj@ucw.cz>
8  *  (and others)
9  */
10 
11 #include <linux/types.h>
12 #include <linux/kernel.h>
13 #include <linux/pci.h>
14 #include <linux/init.h>
15 #include <linux/delay.h>
16 #include <linux/acpi.h>
17 #include <linux/dmi.h>
18 #include "pci-quirks.h"
19 #include "xhci-ext-caps.h"
20 
21 
22 #define UHCI_USBLEGSUP		0xc0		/* legacy support */
23 #define UHCI_USBCMD		0		/* command register */
24 #define UHCI_USBINTR		4		/* interrupt register */
25 #define UHCI_USBLEGSUP_RWC	0x8f00		/* the R/WC bits */
26 #define UHCI_USBLEGSUP_RO	0x5040		/* R/O and reserved bits */
27 #define UHCI_USBCMD_RUN		0x0001		/* RUN/STOP bit */
28 #define UHCI_USBCMD_HCRESET	0x0002		/* Host Controller reset */
29 #define UHCI_USBCMD_EGSM	0x0008		/* Global Suspend Mode */
30 #define UHCI_USBCMD_CONFIGURE	0x0040		/* Config Flag */
31 #define UHCI_USBINTR_RESUME	0x0002		/* Resume interrupt enable */
32 
33 #define OHCI_CONTROL		0x04
34 #define OHCI_CMDSTATUS		0x08
35 #define OHCI_INTRSTATUS		0x0c
36 #define OHCI_INTRENABLE		0x10
37 #define OHCI_INTRDISABLE	0x14
38 #define OHCI_FMINTERVAL		0x34
39 #define OHCI_HCR		(1 << 0)	/* host controller reset */
40 #define OHCI_OCR		(1 << 3)	/* ownership change request */
41 #define OHCI_CTRL_RWC		(1 << 9)	/* remote wakeup connected */
42 #define OHCI_CTRL_IR		(1 << 8)	/* interrupt routing */
43 #define OHCI_INTR_OC		(1 << 30)	/* ownership change */
44 
45 #define EHCI_HCC_PARAMS		0x08		/* extended capabilities */
46 #define EHCI_USBCMD		0		/* command register */
47 #define EHCI_USBCMD_RUN		(1 << 0)	/* RUN/STOP bit */
48 #define EHCI_USBSTS		4		/* status register */
49 #define EHCI_USBSTS_HALTED	(1 << 12)	/* HCHalted bit */
50 #define EHCI_USBINTR		8		/* interrupt register */
51 #define EHCI_CONFIGFLAG		0x40		/* configured flag register */
52 #define EHCI_USBLEGSUP		0		/* legacy support register */
53 #define EHCI_USBLEGSUP_BIOS	(1 << 16)	/* BIOS semaphore */
54 #define EHCI_USBLEGSUP_OS	(1 << 24)	/* OS semaphore */
55 #define EHCI_USBLEGCTLSTS	4		/* legacy control/status */
56 #define EHCI_USBLEGCTLSTS_SOOE	(1 << 13)	/* SMI on ownership change */
57 
58 /* AMD quirk use */
59 #define	AB_REG_BAR_LOW		0xe0
60 #define	AB_REG_BAR_HIGH		0xe1
61 #define	AB_REG_BAR_SB700	0xf0
62 #define	AB_INDX(addr)		((addr) + 0x00)
63 #define	AB_DATA(addr)		((addr) + 0x04)
64 #define	AX_INDXC		0x30
65 #define	AX_DATAC		0x34
66 
67 #define	NB_PCIE_INDX_ADDR	0xe0
68 #define	NB_PCIE_INDX_DATA	0xe4
69 #define	PCIE_P_CNTL		0x10040
70 #define	BIF_NB			0x10002
71 #define	NB_PIF0_PWRDOWN_0	0x01100012
72 #define	NB_PIF0_PWRDOWN_1	0x01100013
73 
74 #define USB_INTEL_XUSB2PR      0xD0
75 #define USB_INTEL_USB3_PSSEN   0xD8
76 
77 static struct amd_chipset_info {
78 	struct pci_dev	*nb_dev;
79 	struct pci_dev	*smbus_dev;
80 	int nb_type;
81 	int sb_type;
82 	int isoc_reqs;
83 	int probe_count;
84 	int probe_result;
85 } amd_chipset;
86 
87 static DEFINE_SPINLOCK(amd_lock);
88 
89 int usb_amd_find_chipset_info(void)
90 {
91 	u8 rev = 0;
92 	unsigned long flags;
93 	struct amd_chipset_info info;
94 	int ret;
95 
96 	spin_lock_irqsave(&amd_lock, flags);
97 
98 	/* probe only once */
99 	if (amd_chipset.probe_count > 0) {
100 		amd_chipset.probe_count++;
101 		spin_unlock_irqrestore(&amd_lock, flags);
102 		return amd_chipset.probe_result;
103 	}
104 	memset(&info, 0, sizeof(info));
105 	spin_unlock_irqrestore(&amd_lock, flags);
106 
107 	info.smbus_dev = pci_get_device(PCI_VENDOR_ID_ATI, 0x4385, NULL);
108 	if (info.smbus_dev) {
109 		rev = info.smbus_dev->revision;
110 		if (rev >= 0x40)
111 			info.sb_type = 1;
112 		else if (rev >= 0x30 && rev <= 0x3b)
113 			info.sb_type = 3;
114 	} else {
115 		info.smbus_dev = pci_get_device(PCI_VENDOR_ID_AMD,
116 						0x780b, NULL);
117 		if (!info.smbus_dev) {
118 			ret = 0;
119 			goto commit;
120 		}
121 
122 		rev = info.smbus_dev->revision;
123 		if (rev >= 0x11 && rev <= 0x18)
124 			info.sb_type = 2;
125 	}
126 
127 	if (info.sb_type == 0) {
128 		if (info.smbus_dev) {
129 			pci_dev_put(info.smbus_dev);
130 			info.smbus_dev = NULL;
131 		}
132 		ret = 0;
133 		goto commit;
134 	}
135 
136 	info.nb_dev = pci_get_device(PCI_VENDOR_ID_AMD, 0x9601, NULL);
137 	if (info.nb_dev) {
138 		info.nb_type = 1;
139 	} else {
140 		info.nb_dev = pci_get_device(PCI_VENDOR_ID_AMD, 0x1510, NULL);
141 		if (info.nb_dev) {
142 			info.nb_type = 2;
143 		} else {
144 			info.nb_dev = pci_get_device(PCI_VENDOR_ID_AMD,
145 						     0x9600, NULL);
146 			if (info.nb_dev)
147 				info.nb_type = 3;
148 		}
149 	}
150 
151 	ret = info.probe_result = 1;
152 	printk(KERN_DEBUG "QUIRK: Enable AMD PLL fix\n");
153 
154 commit:
155 
156 	spin_lock_irqsave(&amd_lock, flags);
157 	if (amd_chipset.probe_count > 0) {
158 		/* race - someone else was faster - drop devices */
159 
160 		/* Mark that we where here */
161 		amd_chipset.probe_count++;
162 		ret = amd_chipset.probe_result;
163 
164 		spin_unlock_irqrestore(&amd_lock, flags);
165 
166 		if (info.nb_dev)
167 			pci_dev_put(info.nb_dev);
168 		if (info.smbus_dev)
169 			pci_dev_put(info.smbus_dev);
170 
171 	} else {
172 		/* no race - commit the result */
173 		info.probe_count++;
174 		amd_chipset = info;
175 		spin_unlock_irqrestore(&amd_lock, flags);
176 	}
177 
178 	return ret;
179 }
180 EXPORT_SYMBOL_GPL(usb_amd_find_chipset_info);
181 
182 /*
183  * The hardware normally enables the A-link power management feature, which
184  * lets the system lower the power consumption in idle states.
185  *
186  * This USB quirk prevents the link going into that lower power state
187  * during isochronous transfers.
188  *
189  * Without this quirk, isochronous stream on OHCI/EHCI/xHCI controllers of
190  * some AMD platforms may stutter or have breaks occasionally.
191  */
192 static void usb_amd_quirk_pll(int disable)
193 {
194 	u32 addr, addr_low, addr_high, val;
195 	u32 bit = disable ? 0 : 1;
196 	unsigned long flags;
197 
198 	spin_lock_irqsave(&amd_lock, flags);
199 
200 	if (disable) {
201 		amd_chipset.isoc_reqs++;
202 		if (amd_chipset.isoc_reqs > 1) {
203 			spin_unlock_irqrestore(&amd_lock, flags);
204 			return;
205 		}
206 	} else {
207 		amd_chipset.isoc_reqs--;
208 		if (amd_chipset.isoc_reqs > 0) {
209 			spin_unlock_irqrestore(&amd_lock, flags);
210 			return;
211 		}
212 	}
213 
214 	if (amd_chipset.sb_type == 1 || amd_chipset.sb_type == 2) {
215 		outb_p(AB_REG_BAR_LOW, 0xcd6);
216 		addr_low = inb_p(0xcd7);
217 		outb_p(AB_REG_BAR_HIGH, 0xcd6);
218 		addr_high = inb_p(0xcd7);
219 		addr = addr_high << 8 | addr_low;
220 
221 		outl_p(0x30, AB_INDX(addr));
222 		outl_p(0x40, AB_DATA(addr));
223 		outl_p(0x34, AB_INDX(addr));
224 		val = inl_p(AB_DATA(addr));
225 	} else if (amd_chipset.sb_type == 3) {
226 		pci_read_config_dword(amd_chipset.smbus_dev,
227 					AB_REG_BAR_SB700, &addr);
228 		outl(AX_INDXC, AB_INDX(addr));
229 		outl(0x40, AB_DATA(addr));
230 		outl(AX_DATAC, AB_INDX(addr));
231 		val = inl(AB_DATA(addr));
232 	} else {
233 		spin_unlock_irqrestore(&amd_lock, flags);
234 		return;
235 	}
236 
237 	if (disable) {
238 		val &= ~0x08;
239 		val |= (1 << 4) | (1 << 9);
240 	} else {
241 		val |= 0x08;
242 		val &= ~((1 << 4) | (1 << 9));
243 	}
244 	outl_p(val, AB_DATA(addr));
245 
246 	if (!amd_chipset.nb_dev) {
247 		spin_unlock_irqrestore(&amd_lock, flags);
248 		return;
249 	}
250 
251 	if (amd_chipset.nb_type == 1 || amd_chipset.nb_type == 3) {
252 		addr = PCIE_P_CNTL;
253 		pci_write_config_dword(amd_chipset.nb_dev,
254 					NB_PCIE_INDX_ADDR, addr);
255 		pci_read_config_dword(amd_chipset.nb_dev,
256 					NB_PCIE_INDX_DATA, &val);
257 
258 		val &= ~(1 | (1 << 3) | (1 << 4) | (1 << 9) | (1 << 12));
259 		val |= bit | (bit << 3) | (bit << 12);
260 		val |= ((!bit) << 4) | ((!bit) << 9);
261 		pci_write_config_dword(amd_chipset.nb_dev,
262 					NB_PCIE_INDX_DATA, val);
263 
264 		addr = BIF_NB;
265 		pci_write_config_dword(amd_chipset.nb_dev,
266 					NB_PCIE_INDX_ADDR, addr);
267 		pci_read_config_dword(amd_chipset.nb_dev,
268 					NB_PCIE_INDX_DATA, &val);
269 		val &= ~(1 << 8);
270 		val |= bit << 8;
271 
272 		pci_write_config_dword(amd_chipset.nb_dev,
273 					NB_PCIE_INDX_DATA, val);
274 	} else if (amd_chipset.nb_type == 2) {
275 		addr = NB_PIF0_PWRDOWN_0;
276 		pci_write_config_dword(amd_chipset.nb_dev,
277 					NB_PCIE_INDX_ADDR, addr);
278 		pci_read_config_dword(amd_chipset.nb_dev,
279 					NB_PCIE_INDX_DATA, &val);
280 		if (disable)
281 			val &= ~(0x3f << 7);
282 		else
283 			val |= 0x3f << 7;
284 
285 		pci_write_config_dword(amd_chipset.nb_dev,
286 					NB_PCIE_INDX_DATA, val);
287 
288 		addr = NB_PIF0_PWRDOWN_1;
289 		pci_write_config_dword(amd_chipset.nb_dev,
290 					NB_PCIE_INDX_ADDR, addr);
291 		pci_read_config_dword(amd_chipset.nb_dev,
292 					NB_PCIE_INDX_DATA, &val);
293 		if (disable)
294 			val &= ~(0x3f << 7);
295 		else
296 			val |= 0x3f << 7;
297 
298 		pci_write_config_dword(amd_chipset.nb_dev,
299 					NB_PCIE_INDX_DATA, val);
300 	}
301 
302 	spin_unlock_irqrestore(&amd_lock, flags);
303 	return;
304 }
305 
306 void usb_amd_quirk_pll_disable(void)
307 {
308 	usb_amd_quirk_pll(1);
309 }
310 EXPORT_SYMBOL_GPL(usb_amd_quirk_pll_disable);
311 
312 void usb_amd_quirk_pll_enable(void)
313 {
314 	usb_amd_quirk_pll(0);
315 }
316 EXPORT_SYMBOL_GPL(usb_amd_quirk_pll_enable);
317 
318 void usb_amd_dev_put(void)
319 {
320 	struct pci_dev *nb, *smbus;
321 	unsigned long flags;
322 
323 	spin_lock_irqsave(&amd_lock, flags);
324 
325 	amd_chipset.probe_count--;
326 	if (amd_chipset.probe_count > 0) {
327 		spin_unlock_irqrestore(&amd_lock, flags);
328 		return;
329 	}
330 
331 	/* save them to pci_dev_put outside of spinlock */
332 	nb    = amd_chipset.nb_dev;
333 	smbus = amd_chipset.smbus_dev;
334 
335 	amd_chipset.nb_dev = NULL;
336 	amd_chipset.smbus_dev = NULL;
337 	amd_chipset.nb_type = 0;
338 	amd_chipset.sb_type = 0;
339 	amd_chipset.isoc_reqs = 0;
340 	amd_chipset.probe_result = 0;
341 
342 	spin_unlock_irqrestore(&amd_lock, flags);
343 
344 	if (nb)
345 		pci_dev_put(nb);
346 	if (smbus)
347 		pci_dev_put(smbus);
348 }
349 EXPORT_SYMBOL_GPL(usb_amd_dev_put);
350 
351 /*
352  * Make sure the controller is completely inactive, unable to
353  * generate interrupts or do DMA.
354  */
355 void uhci_reset_hc(struct pci_dev *pdev, unsigned long base)
356 {
357 	/* Turn off PIRQ enable and SMI enable.  (This also turns off the
358 	 * BIOS's USB Legacy Support.)  Turn off all the R/WC bits too.
359 	 */
360 	pci_write_config_word(pdev, UHCI_USBLEGSUP, UHCI_USBLEGSUP_RWC);
361 
362 	/* Reset the HC - this will force us to get a
363 	 * new notification of any already connected
364 	 * ports due to the virtual disconnect that it
365 	 * implies.
366 	 */
367 	outw(UHCI_USBCMD_HCRESET, base + UHCI_USBCMD);
368 	mb();
369 	udelay(5);
370 	if (inw(base + UHCI_USBCMD) & UHCI_USBCMD_HCRESET)
371 		dev_warn(&pdev->dev, "HCRESET not completed yet!\n");
372 
373 	/* Just to be safe, disable interrupt requests and
374 	 * make sure the controller is stopped.
375 	 */
376 	outw(0, base + UHCI_USBINTR);
377 	outw(0, base + UHCI_USBCMD);
378 }
379 EXPORT_SYMBOL_GPL(uhci_reset_hc);
380 
381 /*
382  * Initialize a controller that was newly discovered or has just been
383  * resumed.  In either case we can't be sure of its previous state.
384  *
385  * Returns: 1 if the controller was reset, 0 otherwise.
386  */
387 int uhci_check_and_reset_hc(struct pci_dev *pdev, unsigned long base)
388 {
389 	u16 legsup;
390 	unsigned int cmd, intr;
391 
392 	/*
393 	 * When restarting a suspended controller, we expect all the
394 	 * settings to be the same as we left them:
395 	 *
396 	 *	PIRQ and SMI disabled, no R/W bits set in USBLEGSUP;
397 	 *	Controller is stopped and configured with EGSM set;
398 	 *	No interrupts enabled except possibly Resume Detect.
399 	 *
400 	 * If any of these conditions are violated we do a complete reset.
401 	 */
402 	pci_read_config_word(pdev, UHCI_USBLEGSUP, &legsup);
403 	if (legsup & ~(UHCI_USBLEGSUP_RO | UHCI_USBLEGSUP_RWC)) {
404 		dev_dbg(&pdev->dev, "%s: legsup = 0x%04x\n",
405 				__func__, legsup);
406 		goto reset_needed;
407 	}
408 
409 	cmd = inw(base + UHCI_USBCMD);
410 	if ((cmd & UHCI_USBCMD_RUN) || !(cmd & UHCI_USBCMD_CONFIGURE) ||
411 			!(cmd & UHCI_USBCMD_EGSM)) {
412 		dev_dbg(&pdev->dev, "%s: cmd = 0x%04x\n",
413 				__func__, cmd);
414 		goto reset_needed;
415 	}
416 
417 	intr = inw(base + UHCI_USBINTR);
418 	if (intr & (~UHCI_USBINTR_RESUME)) {
419 		dev_dbg(&pdev->dev, "%s: intr = 0x%04x\n",
420 				__func__, intr);
421 		goto reset_needed;
422 	}
423 	return 0;
424 
425 reset_needed:
426 	dev_dbg(&pdev->dev, "Performing full reset\n");
427 	uhci_reset_hc(pdev, base);
428 	return 1;
429 }
430 EXPORT_SYMBOL_GPL(uhci_check_and_reset_hc);
431 
432 static inline int io_type_enabled(struct pci_dev *pdev, unsigned int mask)
433 {
434 	u16 cmd;
435 	return !pci_read_config_word(pdev, PCI_COMMAND, &cmd) && (cmd & mask);
436 }
437 
438 #define pio_enabled(dev) io_type_enabled(dev, PCI_COMMAND_IO)
439 #define mmio_enabled(dev) io_type_enabled(dev, PCI_COMMAND_MEMORY)
440 
441 static void __devinit quirk_usb_handoff_uhci(struct pci_dev *pdev)
442 {
443 	unsigned long base = 0;
444 	int i;
445 
446 	if (!pio_enabled(pdev))
447 		return;
448 
449 	for (i = 0; i < PCI_ROM_RESOURCE; i++)
450 		if ((pci_resource_flags(pdev, i) & IORESOURCE_IO)) {
451 			base = pci_resource_start(pdev, i);
452 			break;
453 		}
454 
455 	if (base)
456 		uhci_check_and_reset_hc(pdev, base);
457 }
458 
459 static int __devinit mmio_resource_enabled(struct pci_dev *pdev, int idx)
460 {
461 	return pci_resource_start(pdev, idx) && mmio_enabled(pdev);
462 }
463 
464 static void __devinit quirk_usb_handoff_ohci(struct pci_dev *pdev)
465 {
466 	void __iomem *base;
467 	u32 control;
468 
469 	if (!mmio_resource_enabled(pdev, 0))
470 		return;
471 
472 	base = pci_ioremap_bar(pdev, 0);
473 	if (base == NULL)
474 		return;
475 
476 	control = readl(base + OHCI_CONTROL);
477 
478 /* On PA-RISC, PDC can leave IR set incorrectly; ignore it there. */
479 #ifdef __hppa__
480 #define	OHCI_CTRL_MASK		(OHCI_CTRL_RWC | OHCI_CTRL_IR)
481 #else
482 #define	OHCI_CTRL_MASK		OHCI_CTRL_RWC
483 
484 	if (control & OHCI_CTRL_IR) {
485 		int wait_time = 500; /* arbitrary; 5 seconds */
486 		writel(OHCI_INTR_OC, base + OHCI_INTRENABLE);
487 		writel(OHCI_OCR, base + OHCI_CMDSTATUS);
488 		while (wait_time > 0 &&
489 				readl(base + OHCI_CONTROL) & OHCI_CTRL_IR) {
490 			wait_time -= 10;
491 			msleep(10);
492 		}
493 		if (wait_time <= 0)
494 			dev_warn(&pdev->dev, "OHCI: BIOS handoff failed"
495 					" (BIOS bug?) %08x\n",
496 					readl(base + OHCI_CONTROL));
497 	}
498 #endif
499 
500 	/* reset controller, preserving RWC (and possibly IR) */
501 	writel(control & OHCI_CTRL_MASK, base + OHCI_CONTROL);
502 	readl(base + OHCI_CONTROL);
503 
504 	/* Some NVIDIA controllers stop working if kept in RESET for too long */
505 	if (pdev->vendor == PCI_VENDOR_ID_NVIDIA) {
506 		u32 fminterval;
507 		int cnt;
508 
509 		/* drive reset for at least 50 ms (7.1.7.5) */
510 		msleep(50);
511 
512 		/* software reset of the controller, preserving HcFmInterval */
513 		fminterval = readl(base + OHCI_FMINTERVAL);
514 		writel(OHCI_HCR, base + OHCI_CMDSTATUS);
515 
516 		/* reset requires max 10 us delay */
517 		for (cnt = 30; cnt > 0; --cnt) {	/* ... allow extra time */
518 			if ((readl(base + OHCI_CMDSTATUS) & OHCI_HCR) == 0)
519 				break;
520 			udelay(1);
521 		}
522 		writel(fminterval, base + OHCI_FMINTERVAL);
523 
524 		/* Now we're in the SUSPEND state with all devices reset
525 		 * and wakeups and interrupts disabled
526 		 */
527 	}
528 
529 	/*
530 	 * disable interrupts
531 	 */
532 	writel(~(u32)0, base + OHCI_INTRDISABLE);
533 	writel(~(u32)0, base + OHCI_INTRSTATUS);
534 
535 	iounmap(base);
536 }
537 
538 static const struct dmi_system_id __devinitconst ehci_dmi_nohandoff_table[] = {
539 	{
540 		/*  Pegatron Lucid (ExoPC) */
541 		.matches = {
542 			DMI_MATCH(DMI_BOARD_NAME, "EXOPG06411"),
543 			DMI_MATCH(DMI_BIOS_VERSION, "Lucid-CE-133"),
544 		},
545 	},
546 	{
547 		/*  Pegatron Lucid (Ordissimo AIRIS) */
548 		.matches = {
549 			DMI_MATCH(DMI_BOARD_NAME, "M11JB"),
550 			DMI_MATCH(DMI_BIOS_VERSION, "Lucid-GE-133"),
551 		},
552 	},
553 	{ }
554 };
555 
556 static void __devinit ehci_bios_handoff(struct pci_dev *pdev,
557 					void __iomem *op_reg_base,
558 					u32 cap, u8 offset)
559 {
560 	int try_handoff = 1, tried_handoff = 0;
561 
562 	/* The Pegatron Lucid tablet sporadically waits for 98 seconds trying
563 	 * the handoff on its unused controller.  Skip it. */
564 	if (pdev->vendor == 0x8086 && pdev->device == 0x283a) {
565 		if (dmi_check_system(ehci_dmi_nohandoff_table))
566 			try_handoff = 0;
567 	}
568 
569 	if (try_handoff && (cap & EHCI_USBLEGSUP_BIOS)) {
570 		dev_dbg(&pdev->dev, "EHCI: BIOS handoff\n");
571 
572 #if 0
573 /* aleksey_gorelov@phoenix.com reports that some systems need SMI forced on,
574  * but that seems dubious in general (the BIOS left it off intentionally)
575  * and is known to prevent some systems from booting.  so we won't do this
576  * unless maybe we can determine when we're on a system that needs SMI forced.
577  */
578 		/* BIOS workaround (?): be sure the pre-Linux code
579 		 * receives the SMI
580 		 */
581 		pci_read_config_dword(pdev, offset + EHCI_USBLEGCTLSTS, &val);
582 		pci_write_config_dword(pdev, offset + EHCI_USBLEGCTLSTS,
583 				       val | EHCI_USBLEGCTLSTS_SOOE);
584 #endif
585 
586 		/* some systems get upset if this semaphore is
587 		 * set for any other reason than forcing a BIOS
588 		 * handoff..
589 		 */
590 		pci_write_config_byte(pdev, offset + 3, 1);
591 	}
592 
593 	/* if boot firmware now owns EHCI, spin till it hands it over. */
594 	if (try_handoff) {
595 		int msec = 1000;
596 		while ((cap & EHCI_USBLEGSUP_BIOS) && (msec > 0)) {
597 			tried_handoff = 1;
598 			msleep(10);
599 			msec -= 10;
600 			pci_read_config_dword(pdev, offset, &cap);
601 		}
602 	}
603 
604 	if (cap & EHCI_USBLEGSUP_BIOS) {
605 		/* well, possibly buggy BIOS... try to shut it down,
606 		 * and hope nothing goes too wrong
607 		 */
608 		if (try_handoff)
609 			dev_warn(&pdev->dev, "EHCI: BIOS handoff failed"
610 				 " (BIOS bug?) %08x\n", cap);
611 		pci_write_config_byte(pdev, offset + 2, 0);
612 	}
613 
614 	/* just in case, always disable EHCI SMIs */
615 	pci_write_config_dword(pdev, offset + EHCI_USBLEGCTLSTS, 0);
616 
617 	/* If the BIOS ever owned the controller then we can't expect
618 	 * any power sessions to remain intact.
619 	 */
620 	if (tried_handoff)
621 		writel(0, op_reg_base + EHCI_CONFIGFLAG);
622 }
623 
624 static void __devinit quirk_usb_disable_ehci(struct pci_dev *pdev)
625 {
626 	void __iomem *base, *op_reg_base;
627 	u32	hcc_params, cap, val;
628 	u8	offset, cap_length;
629 	int	wait_time, delta, count = 256/4;
630 
631 	if (!mmio_resource_enabled(pdev, 0))
632 		return;
633 
634 	base = pci_ioremap_bar(pdev, 0);
635 	if (base == NULL)
636 		return;
637 
638 	cap_length = readb(base);
639 	op_reg_base = base + cap_length;
640 
641 	/* EHCI 0.96 and later may have "extended capabilities"
642 	 * spec section 5.1 explains the bios handoff, e.g. for
643 	 * booting from USB disk or using a usb keyboard
644 	 */
645 	hcc_params = readl(base + EHCI_HCC_PARAMS);
646 	offset = (hcc_params >> 8) & 0xff;
647 	while (offset && --count) {
648 		pci_read_config_dword(pdev, offset, &cap);
649 
650 		switch (cap & 0xff) {
651 		case 1:
652 			ehci_bios_handoff(pdev, op_reg_base, cap, offset);
653 			break;
654 		case 0: /* Illegal reserved cap, set cap=0 so we exit */
655 			cap = 0; /* then fallthrough... */
656 		default:
657 			dev_warn(&pdev->dev, "EHCI: unrecognized capability "
658 				 "%02x\n", cap & 0xff);
659 		}
660 		offset = (cap >> 8) & 0xff;
661 	}
662 	if (!count)
663 		dev_printk(KERN_DEBUG, &pdev->dev, "EHCI: capability loop?\n");
664 
665 	/*
666 	 * halt EHCI & disable its interrupts in any case
667 	 */
668 	val = readl(op_reg_base + EHCI_USBSTS);
669 	if ((val & EHCI_USBSTS_HALTED) == 0) {
670 		val = readl(op_reg_base + EHCI_USBCMD);
671 		val &= ~EHCI_USBCMD_RUN;
672 		writel(val, op_reg_base + EHCI_USBCMD);
673 
674 		wait_time = 2000;
675 		delta = 100;
676 		do {
677 			writel(0x3f, op_reg_base + EHCI_USBSTS);
678 			udelay(delta);
679 			wait_time -= delta;
680 			val = readl(op_reg_base + EHCI_USBSTS);
681 			if ((val == ~(u32)0) || (val & EHCI_USBSTS_HALTED)) {
682 				break;
683 			}
684 		} while (wait_time > 0);
685 	}
686 	writel(0, op_reg_base + EHCI_USBINTR);
687 	writel(0x3f, op_reg_base + EHCI_USBSTS);
688 
689 	iounmap(base);
690 }
691 
692 /*
693  * handshake - spin reading a register until handshake completes
694  * @ptr: address of hc register to be read
695  * @mask: bits to look at in result of read
696  * @done: value of those bits when handshake succeeds
697  * @wait_usec: timeout in microseconds
698  * @delay_usec: delay in microseconds to wait between polling
699  *
700  * Polls a register every delay_usec microseconds.
701  * Returns 0 when the mask bits have the value done.
702  * Returns -ETIMEDOUT if this condition is not true after
703  * wait_usec microseconds have passed.
704  */
705 static int handshake(void __iomem *ptr, u32 mask, u32 done,
706 		int wait_usec, int delay_usec)
707 {
708 	u32	result;
709 
710 	do {
711 		result = readl(ptr);
712 		result &= mask;
713 		if (result == done)
714 			return 0;
715 		udelay(delay_usec);
716 		wait_usec -= delay_usec;
717 	} while (wait_usec > 0);
718 	return -ETIMEDOUT;
719 }
720 
721 bool usb_is_intel_switchable_xhci(struct pci_dev *pdev)
722 {
723 	return pdev->class == PCI_CLASS_SERIAL_USB_XHCI &&
724 		pdev->vendor == PCI_VENDOR_ID_INTEL &&
725 		pdev->device == PCI_DEVICE_ID_INTEL_PANTHERPOINT_XHCI;
726 }
727 EXPORT_SYMBOL_GPL(usb_is_intel_switchable_xhci);
728 
729 /*
730  * Intel's Panther Point chipset has two host controllers (EHCI and xHCI) that
731  * share some number of ports.  These ports can be switched between either
732  * controller.  Not all of the ports under the EHCI host controller may be
733  * switchable.
734  *
735  * The ports should be switched over to xHCI before PCI probes for any device
736  * start.  This avoids active devices under EHCI being disconnected during the
737  * port switchover, which could cause loss of data on USB storage devices, or
738  * failed boot when the root file system is on a USB mass storage device and is
739  * enumerated under EHCI first.
740  *
741  * We write into the xHC's PCI configuration space in some Intel-specific
742  * registers to switch the ports over.  The USB 3.0 terminations and the USB
743  * 2.0 data wires are switched separately.  We want to enable the SuperSpeed
744  * terminations before switching the USB 2.0 wires over, so that USB 3.0
745  * devices connect at SuperSpeed, rather than at USB 2.0 speeds.
746  */
747 void usb_enable_xhci_ports(struct pci_dev *xhci_pdev)
748 {
749 	u32		ports_available;
750 
751 	ports_available = 0xffffffff;
752 	/* Write USB3_PSSEN, the USB 3.0 Port SuperSpeed Enable
753 	 * Register, to turn on SuperSpeed terminations for all
754 	 * available ports.
755 	 */
756 	pci_write_config_dword(xhci_pdev, USB_INTEL_USB3_PSSEN,
757 			cpu_to_le32(ports_available));
758 
759 	pci_read_config_dword(xhci_pdev, USB_INTEL_USB3_PSSEN,
760 			&ports_available);
761 	dev_dbg(&xhci_pdev->dev, "USB 3.0 ports that are now enabled "
762 			"under xHCI: 0x%x\n", ports_available);
763 
764 	ports_available = 0xffffffff;
765 	/* Write XUSB2PR, the xHC USB 2.0 Port Routing Register, to
766 	 * switch the USB 2.0 power and data lines over to the xHCI
767 	 * host.
768 	 */
769 	pci_write_config_dword(xhci_pdev, USB_INTEL_XUSB2PR,
770 			cpu_to_le32(ports_available));
771 
772 	pci_read_config_dword(xhci_pdev, USB_INTEL_XUSB2PR,
773 			&ports_available);
774 	dev_dbg(&xhci_pdev->dev, "USB 2.0 ports that are now switched over "
775 			"to xHCI: 0x%x\n", ports_available);
776 }
777 EXPORT_SYMBOL_GPL(usb_enable_xhci_ports);
778 
779 /**
780  * PCI Quirks for xHCI.
781  *
782  * Takes care of the handoff between the Pre-OS (i.e. BIOS) and the OS.
783  * It signals to the BIOS that the OS wants control of the host controller,
784  * and then waits 5 seconds for the BIOS to hand over control.
785  * If we timeout, assume the BIOS is broken and take control anyway.
786  */
787 static void __devinit quirk_usb_handoff_xhci(struct pci_dev *pdev)
788 {
789 	void __iomem *base;
790 	int ext_cap_offset;
791 	void __iomem *op_reg_base;
792 	u32 val;
793 	int timeout;
794 
795 	if (!mmio_resource_enabled(pdev, 0))
796 		return;
797 
798 	base = ioremap_nocache(pci_resource_start(pdev, 0),
799 				pci_resource_len(pdev, 0));
800 	if (base == NULL)
801 		return;
802 
803 	/*
804 	 * Find the Legacy Support Capability register -
805 	 * this is optional for xHCI host controllers.
806 	 */
807 	ext_cap_offset = xhci_find_next_cap_offset(base, XHCI_HCC_PARAMS_OFFSET);
808 	do {
809 		if (!ext_cap_offset)
810 			/* We've reached the end of the extended capabilities */
811 			goto hc_init;
812 		val = readl(base + ext_cap_offset);
813 		if (XHCI_EXT_CAPS_ID(val) == XHCI_EXT_CAPS_LEGACY)
814 			break;
815 		ext_cap_offset = xhci_find_next_cap_offset(base, ext_cap_offset);
816 	} while (1);
817 
818 	/* If the BIOS owns the HC, signal that the OS wants it, and wait */
819 	if (val & XHCI_HC_BIOS_OWNED) {
820 		writel(val | XHCI_HC_OS_OWNED, base + ext_cap_offset);
821 
822 		/* Wait for 5 seconds with 10 microsecond polling interval */
823 		timeout = handshake(base + ext_cap_offset, XHCI_HC_BIOS_OWNED,
824 				0, 5000, 10);
825 
826 		/* Assume a buggy BIOS and take HC ownership anyway */
827 		if (timeout) {
828 			dev_warn(&pdev->dev, "xHCI BIOS handoff failed"
829 					" (BIOS bug ?) %08x\n", val);
830 			writel(val & ~XHCI_HC_BIOS_OWNED, base + ext_cap_offset);
831 		}
832 	}
833 
834 	/* Disable any BIOS SMIs */
835 	writel(XHCI_LEGACY_DISABLE_SMI,
836 			base + ext_cap_offset + XHCI_LEGACY_CONTROL_OFFSET);
837 
838 	if (usb_is_intel_switchable_xhci(pdev))
839 		usb_enable_xhci_ports(pdev);
840 hc_init:
841 	op_reg_base = base + XHCI_HC_LENGTH(readl(base));
842 
843 	/* Wait for the host controller to be ready before writing any
844 	 * operational or runtime registers.  Wait 5 seconds and no more.
845 	 */
846 	timeout = handshake(op_reg_base + XHCI_STS_OFFSET, XHCI_STS_CNR, 0,
847 			5000, 10);
848 	/* Assume a buggy HC and start HC initialization anyway */
849 	if (timeout) {
850 		val = readl(op_reg_base + XHCI_STS_OFFSET);
851 		dev_warn(&pdev->dev,
852 				"xHCI HW not ready after 5 sec (HC bug?) "
853 				"status = 0x%x\n", val);
854 	}
855 
856 	/* Send the halt and disable interrupts command */
857 	val = readl(op_reg_base + XHCI_CMD_OFFSET);
858 	val &= ~(XHCI_CMD_RUN | XHCI_IRQS);
859 	writel(val, op_reg_base + XHCI_CMD_OFFSET);
860 
861 	/* Wait for the HC to halt - poll every 125 usec (one microframe). */
862 	timeout = handshake(op_reg_base + XHCI_STS_OFFSET, XHCI_STS_HALT, 1,
863 			XHCI_MAX_HALT_USEC, 125);
864 	if (timeout) {
865 		val = readl(op_reg_base + XHCI_STS_OFFSET);
866 		dev_warn(&pdev->dev,
867 				"xHCI HW did not halt within %d usec "
868 				"status = 0x%x\n", XHCI_MAX_HALT_USEC, val);
869 	}
870 
871 	iounmap(base);
872 }
873 
874 static void __devinit quirk_usb_early_handoff(struct pci_dev *pdev)
875 {
876 	if (pdev->class == PCI_CLASS_SERIAL_USB_UHCI)
877 		quirk_usb_handoff_uhci(pdev);
878 	else if (pdev->class == PCI_CLASS_SERIAL_USB_OHCI)
879 		quirk_usb_handoff_ohci(pdev);
880 	else if (pdev->class == PCI_CLASS_SERIAL_USB_EHCI)
881 		quirk_usb_disable_ehci(pdev);
882 	else if (pdev->class == PCI_CLASS_SERIAL_USB_XHCI)
883 		quirk_usb_handoff_xhci(pdev);
884 }
885 DECLARE_PCI_FIXUP_FINAL(PCI_ANY_ID, PCI_ANY_ID, quirk_usb_early_handoff);
886