xref: /openbmc/linux/drivers/usb/host/pci-quirks.c (revision 54cbac81)
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/kconfig.h>
13 #include <linux/kernel.h>
14 #include <linux/pci.h>
15 #include <linux/init.h>
16 #include <linux/delay.h>
17 #include <linux/export.h>
18 #include <linux/acpi.h>
19 #include <linux/dmi.h>
20 #include "pci-quirks.h"
21 #include "xhci-ext-caps.h"
22 
23 
24 #define UHCI_USBLEGSUP		0xc0		/* legacy support */
25 #define UHCI_USBCMD		0		/* command register */
26 #define UHCI_USBINTR		4		/* interrupt register */
27 #define UHCI_USBLEGSUP_RWC	0x8f00		/* the R/WC bits */
28 #define UHCI_USBLEGSUP_RO	0x5040		/* R/O and reserved bits */
29 #define UHCI_USBCMD_RUN		0x0001		/* RUN/STOP bit */
30 #define UHCI_USBCMD_HCRESET	0x0002		/* Host Controller reset */
31 #define UHCI_USBCMD_EGSM	0x0008		/* Global Suspend Mode */
32 #define UHCI_USBCMD_CONFIGURE	0x0040		/* Config Flag */
33 #define UHCI_USBINTR_RESUME	0x0002		/* Resume interrupt enable */
34 
35 #define OHCI_CONTROL		0x04
36 #define OHCI_CMDSTATUS		0x08
37 #define OHCI_INTRSTATUS		0x0c
38 #define OHCI_INTRENABLE		0x10
39 #define OHCI_INTRDISABLE	0x14
40 #define OHCI_FMINTERVAL		0x34
41 #define OHCI_HCFS		(3 << 6)	/* hc functional state */
42 #define OHCI_HCR		(1 << 0)	/* host controller reset */
43 #define OHCI_OCR		(1 << 3)	/* ownership change request */
44 #define OHCI_CTRL_RWC		(1 << 9)	/* remote wakeup connected */
45 #define OHCI_CTRL_IR		(1 << 8)	/* interrupt routing */
46 #define OHCI_INTR_OC		(1 << 30)	/* ownership change */
47 
48 #define EHCI_HCC_PARAMS		0x08		/* extended capabilities */
49 #define EHCI_USBCMD		0		/* command register */
50 #define EHCI_USBCMD_RUN		(1 << 0)	/* RUN/STOP bit */
51 #define EHCI_USBSTS		4		/* status register */
52 #define EHCI_USBSTS_HALTED	(1 << 12)	/* HCHalted bit */
53 #define EHCI_USBINTR		8		/* interrupt register */
54 #define EHCI_CONFIGFLAG		0x40		/* configured flag register */
55 #define EHCI_USBLEGSUP		0		/* legacy support register */
56 #define EHCI_USBLEGSUP_BIOS	(1 << 16)	/* BIOS semaphore */
57 #define EHCI_USBLEGSUP_OS	(1 << 24)	/* OS semaphore */
58 #define EHCI_USBLEGCTLSTS	4		/* legacy control/status */
59 #define EHCI_USBLEGCTLSTS_SOOE	(1 << 13)	/* SMI on ownership change */
60 
61 /* AMD quirk use */
62 #define	AB_REG_BAR_LOW		0xe0
63 #define	AB_REG_BAR_HIGH		0xe1
64 #define	AB_REG_BAR_SB700	0xf0
65 #define	AB_INDX(addr)		((addr) + 0x00)
66 #define	AB_DATA(addr)		((addr) + 0x04)
67 #define	AX_INDXC		0x30
68 #define	AX_DATAC		0x34
69 
70 #define	NB_PCIE_INDX_ADDR	0xe0
71 #define	NB_PCIE_INDX_DATA	0xe4
72 #define	PCIE_P_CNTL		0x10040
73 #define	BIF_NB			0x10002
74 #define	NB_PIF0_PWRDOWN_0	0x01100012
75 #define	NB_PIF0_PWRDOWN_1	0x01100013
76 
77 #define USB_INTEL_XUSB2PR      0xD0
78 #define USB_INTEL_USB2PRM      0xD4
79 #define USB_INTEL_USB3_PSSEN   0xD8
80 #define USB_INTEL_USB3PRM      0xDC
81 
82 static struct amd_chipset_info {
83 	struct pci_dev	*nb_dev;
84 	struct pci_dev	*smbus_dev;
85 	int nb_type;
86 	int sb_type;
87 	int isoc_reqs;
88 	int probe_count;
89 	int probe_result;
90 } amd_chipset;
91 
92 static DEFINE_SPINLOCK(amd_lock);
93 
94 int usb_amd_find_chipset_info(void)
95 {
96 	u8 rev = 0;
97 	unsigned long flags;
98 	struct amd_chipset_info info;
99 	int ret;
100 
101 	spin_lock_irqsave(&amd_lock, flags);
102 
103 	/* probe only once */
104 	if (amd_chipset.probe_count > 0) {
105 		amd_chipset.probe_count++;
106 		spin_unlock_irqrestore(&amd_lock, flags);
107 		return amd_chipset.probe_result;
108 	}
109 	memset(&info, 0, sizeof(info));
110 	spin_unlock_irqrestore(&amd_lock, flags);
111 
112 	info.smbus_dev = pci_get_device(PCI_VENDOR_ID_ATI, 0x4385, NULL);
113 	if (info.smbus_dev) {
114 		rev = info.smbus_dev->revision;
115 		if (rev >= 0x40)
116 			info.sb_type = 1;
117 		else if (rev >= 0x30 && rev <= 0x3b)
118 			info.sb_type = 3;
119 	} else {
120 		info.smbus_dev = pci_get_device(PCI_VENDOR_ID_AMD,
121 						0x780b, NULL);
122 		if (!info.smbus_dev) {
123 			ret = 0;
124 			goto commit;
125 		}
126 
127 		rev = info.smbus_dev->revision;
128 		if (rev >= 0x11 && rev <= 0x18)
129 			info.sb_type = 2;
130 	}
131 
132 	if (info.sb_type == 0) {
133 		if (info.smbus_dev) {
134 			pci_dev_put(info.smbus_dev);
135 			info.smbus_dev = NULL;
136 		}
137 		ret = 0;
138 		goto commit;
139 	}
140 
141 	info.nb_dev = pci_get_device(PCI_VENDOR_ID_AMD, 0x9601, NULL);
142 	if (info.nb_dev) {
143 		info.nb_type = 1;
144 	} else {
145 		info.nb_dev = pci_get_device(PCI_VENDOR_ID_AMD, 0x1510, NULL);
146 		if (info.nb_dev) {
147 			info.nb_type = 2;
148 		} else {
149 			info.nb_dev = pci_get_device(PCI_VENDOR_ID_AMD,
150 						     0x9600, NULL);
151 			if (info.nb_dev)
152 				info.nb_type = 3;
153 		}
154 	}
155 
156 	ret = info.probe_result = 1;
157 	printk(KERN_DEBUG "QUIRK: Enable AMD PLL fix\n");
158 
159 commit:
160 
161 	spin_lock_irqsave(&amd_lock, flags);
162 	if (amd_chipset.probe_count > 0) {
163 		/* race - someone else was faster - drop devices */
164 
165 		/* Mark that we where here */
166 		amd_chipset.probe_count++;
167 		ret = amd_chipset.probe_result;
168 
169 		spin_unlock_irqrestore(&amd_lock, flags);
170 
171 		if (info.nb_dev)
172 			pci_dev_put(info.nb_dev);
173 		if (info.smbus_dev)
174 			pci_dev_put(info.smbus_dev);
175 
176 	} else {
177 		/* no race - commit the result */
178 		info.probe_count++;
179 		amd_chipset = info;
180 		spin_unlock_irqrestore(&amd_lock, flags);
181 	}
182 
183 	return ret;
184 }
185 EXPORT_SYMBOL_GPL(usb_amd_find_chipset_info);
186 
187 /*
188  * The hardware normally enables the A-link power management feature, which
189  * lets the system lower the power consumption in idle states.
190  *
191  * This USB quirk prevents the link going into that lower power state
192  * during isochronous transfers.
193  *
194  * Without this quirk, isochronous stream on OHCI/EHCI/xHCI controllers of
195  * some AMD platforms may stutter or have breaks occasionally.
196  */
197 static void usb_amd_quirk_pll(int disable)
198 {
199 	u32 addr, addr_low, addr_high, val;
200 	u32 bit = disable ? 0 : 1;
201 	unsigned long flags;
202 
203 	spin_lock_irqsave(&amd_lock, flags);
204 
205 	if (disable) {
206 		amd_chipset.isoc_reqs++;
207 		if (amd_chipset.isoc_reqs > 1) {
208 			spin_unlock_irqrestore(&amd_lock, flags);
209 			return;
210 		}
211 	} else {
212 		amd_chipset.isoc_reqs--;
213 		if (amd_chipset.isoc_reqs > 0) {
214 			spin_unlock_irqrestore(&amd_lock, flags);
215 			return;
216 		}
217 	}
218 
219 	if (amd_chipset.sb_type == 1 || amd_chipset.sb_type == 2) {
220 		outb_p(AB_REG_BAR_LOW, 0xcd6);
221 		addr_low = inb_p(0xcd7);
222 		outb_p(AB_REG_BAR_HIGH, 0xcd6);
223 		addr_high = inb_p(0xcd7);
224 		addr = addr_high << 8 | addr_low;
225 
226 		outl_p(0x30, AB_INDX(addr));
227 		outl_p(0x40, AB_DATA(addr));
228 		outl_p(0x34, AB_INDX(addr));
229 		val = inl_p(AB_DATA(addr));
230 	} else if (amd_chipset.sb_type == 3) {
231 		pci_read_config_dword(amd_chipset.smbus_dev,
232 					AB_REG_BAR_SB700, &addr);
233 		outl(AX_INDXC, AB_INDX(addr));
234 		outl(0x40, AB_DATA(addr));
235 		outl(AX_DATAC, AB_INDX(addr));
236 		val = inl(AB_DATA(addr));
237 	} else {
238 		spin_unlock_irqrestore(&amd_lock, flags);
239 		return;
240 	}
241 
242 	if (disable) {
243 		val &= ~0x08;
244 		val |= (1 << 4) | (1 << 9);
245 	} else {
246 		val |= 0x08;
247 		val &= ~((1 << 4) | (1 << 9));
248 	}
249 	outl_p(val, AB_DATA(addr));
250 
251 	if (!amd_chipset.nb_dev) {
252 		spin_unlock_irqrestore(&amd_lock, flags);
253 		return;
254 	}
255 
256 	if (amd_chipset.nb_type == 1 || amd_chipset.nb_type == 3) {
257 		addr = PCIE_P_CNTL;
258 		pci_write_config_dword(amd_chipset.nb_dev,
259 					NB_PCIE_INDX_ADDR, addr);
260 		pci_read_config_dword(amd_chipset.nb_dev,
261 					NB_PCIE_INDX_DATA, &val);
262 
263 		val &= ~(1 | (1 << 3) | (1 << 4) | (1 << 9) | (1 << 12));
264 		val |= bit | (bit << 3) | (bit << 12);
265 		val |= ((!bit) << 4) | ((!bit) << 9);
266 		pci_write_config_dword(amd_chipset.nb_dev,
267 					NB_PCIE_INDX_DATA, val);
268 
269 		addr = BIF_NB;
270 		pci_write_config_dword(amd_chipset.nb_dev,
271 					NB_PCIE_INDX_ADDR, addr);
272 		pci_read_config_dword(amd_chipset.nb_dev,
273 					NB_PCIE_INDX_DATA, &val);
274 		val &= ~(1 << 8);
275 		val |= bit << 8;
276 
277 		pci_write_config_dword(amd_chipset.nb_dev,
278 					NB_PCIE_INDX_DATA, val);
279 	} else if (amd_chipset.nb_type == 2) {
280 		addr = NB_PIF0_PWRDOWN_0;
281 		pci_write_config_dword(amd_chipset.nb_dev,
282 					NB_PCIE_INDX_ADDR, addr);
283 		pci_read_config_dword(amd_chipset.nb_dev,
284 					NB_PCIE_INDX_DATA, &val);
285 		if (disable)
286 			val &= ~(0x3f << 7);
287 		else
288 			val |= 0x3f << 7;
289 
290 		pci_write_config_dword(amd_chipset.nb_dev,
291 					NB_PCIE_INDX_DATA, val);
292 
293 		addr = NB_PIF0_PWRDOWN_1;
294 		pci_write_config_dword(amd_chipset.nb_dev,
295 					NB_PCIE_INDX_ADDR, addr);
296 		pci_read_config_dword(amd_chipset.nb_dev,
297 					NB_PCIE_INDX_DATA, &val);
298 		if (disable)
299 			val &= ~(0x3f << 7);
300 		else
301 			val |= 0x3f << 7;
302 
303 		pci_write_config_dword(amd_chipset.nb_dev,
304 					NB_PCIE_INDX_DATA, val);
305 	}
306 
307 	spin_unlock_irqrestore(&amd_lock, flags);
308 	return;
309 }
310 
311 void usb_amd_quirk_pll_disable(void)
312 {
313 	usb_amd_quirk_pll(1);
314 }
315 EXPORT_SYMBOL_GPL(usb_amd_quirk_pll_disable);
316 
317 void usb_amd_quirk_pll_enable(void)
318 {
319 	usb_amd_quirk_pll(0);
320 }
321 EXPORT_SYMBOL_GPL(usb_amd_quirk_pll_enable);
322 
323 void usb_amd_dev_put(void)
324 {
325 	struct pci_dev *nb, *smbus;
326 	unsigned long flags;
327 
328 	spin_lock_irqsave(&amd_lock, flags);
329 
330 	amd_chipset.probe_count--;
331 	if (amd_chipset.probe_count > 0) {
332 		spin_unlock_irqrestore(&amd_lock, flags);
333 		return;
334 	}
335 
336 	/* save them to pci_dev_put outside of spinlock */
337 	nb    = amd_chipset.nb_dev;
338 	smbus = amd_chipset.smbus_dev;
339 
340 	amd_chipset.nb_dev = NULL;
341 	amd_chipset.smbus_dev = NULL;
342 	amd_chipset.nb_type = 0;
343 	amd_chipset.sb_type = 0;
344 	amd_chipset.isoc_reqs = 0;
345 	amd_chipset.probe_result = 0;
346 
347 	spin_unlock_irqrestore(&amd_lock, flags);
348 
349 	if (nb)
350 		pci_dev_put(nb);
351 	if (smbus)
352 		pci_dev_put(smbus);
353 }
354 EXPORT_SYMBOL_GPL(usb_amd_dev_put);
355 
356 /*
357  * Make sure the controller is completely inactive, unable to
358  * generate interrupts or do DMA.
359  */
360 void uhci_reset_hc(struct pci_dev *pdev, unsigned long base)
361 {
362 	/* Turn off PIRQ enable and SMI enable.  (This also turns off the
363 	 * BIOS's USB Legacy Support.)  Turn off all the R/WC bits too.
364 	 */
365 	pci_write_config_word(pdev, UHCI_USBLEGSUP, UHCI_USBLEGSUP_RWC);
366 
367 	/* Reset the HC - this will force us to get a
368 	 * new notification of any already connected
369 	 * ports due to the virtual disconnect that it
370 	 * implies.
371 	 */
372 	outw(UHCI_USBCMD_HCRESET, base + UHCI_USBCMD);
373 	mb();
374 	udelay(5);
375 	if (inw(base + UHCI_USBCMD) & UHCI_USBCMD_HCRESET)
376 		dev_warn(&pdev->dev, "HCRESET not completed yet!\n");
377 
378 	/* Just to be safe, disable interrupt requests and
379 	 * make sure the controller is stopped.
380 	 */
381 	outw(0, base + UHCI_USBINTR);
382 	outw(0, base + UHCI_USBCMD);
383 }
384 EXPORT_SYMBOL_GPL(uhci_reset_hc);
385 
386 /*
387  * Initialize a controller that was newly discovered or has just been
388  * resumed.  In either case we can't be sure of its previous state.
389  *
390  * Returns: 1 if the controller was reset, 0 otherwise.
391  */
392 int uhci_check_and_reset_hc(struct pci_dev *pdev, unsigned long base)
393 {
394 	u16 legsup;
395 	unsigned int cmd, intr;
396 
397 	/*
398 	 * When restarting a suspended controller, we expect all the
399 	 * settings to be the same as we left them:
400 	 *
401 	 *	PIRQ and SMI disabled, no R/W bits set in USBLEGSUP;
402 	 *	Controller is stopped and configured with EGSM set;
403 	 *	No interrupts enabled except possibly Resume Detect.
404 	 *
405 	 * If any of these conditions are violated we do a complete reset.
406 	 */
407 	pci_read_config_word(pdev, UHCI_USBLEGSUP, &legsup);
408 	if (legsup & ~(UHCI_USBLEGSUP_RO | UHCI_USBLEGSUP_RWC)) {
409 		dev_dbg(&pdev->dev, "%s: legsup = 0x%04x\n",
410 				__func__, legsup);
411 		goto reset_needed;
412 	}
413 
414 	cmd = inw(base + UHCI_USBCMD);
415 	if ((cmd & UHCI_USBCMD_RUN) || !(cmd & UHCI_USBCMD_CONFIGURE) ||
416 			!(cmd & UHCI_USBCMD_EGSM)) {
417 		dev_dbg(&pdev->dev, "%s: cmd = 0x%04x\n",
418 				__func__, cmd);
419 		goto reset_needed;
420 	}
421 
422 	intr = inw(base + UHCI_USBINTR);
423 	if (intr & (~UHCI_USBINTR_RESUME)) {
424 		dev_dbg(&pdev->dev, "%s: intr = 0x%04x\n",
425 				__func__, intr);
426 		goto reset_needed;
427 	}
428 	return 0;
429 
430 reset_needed:
431 	dev_dbg(&pdev->dev, "Performing full reset\n");
432 	uhci_reset_hc(pdev, base);
433 	return 1;
434 }
435 EXPORT_SYMBOL_GPL(uhci_check_and_reset_hc);
436 
437 static inline int io_type_enabled(struct pci_dev *pdev, unsigned int mask)
438 {
439 	u16 cmd;
440 	return !pci_read_config_word(pdev, PCI_COMMAND, &cmd) && (cmd & mask);
441 }
442 
443 #define pio_enabled(dev) io_type_enabled(dev, PCI_COMMAND_IO)
444 #define mmio_enabled(dev) io_type_enabled(dev, PCI_COMMAND_MEMORY)
445 
446 static void quirk_usb_handoff_uhci(struct pci_dev *pdev)
447 {
448 	unsigned long base = 0;
449 	int i;
450 
451 	if (!pio_enabled(pdev))
452 		return;
453 
454 	for (i = 0; i < PCI_ROM_RESOURCE; i++)
455 		if ((pci_resource_flags(pdev, i) & IORESOURCE_IO)) {
456 			base = pci_resource_start(pdev, i);
457 			break;
458 		}
459 
460 	if (base)
461 		uhci_check_and_reset_hc(pdev, base);
462 }
463 
464 static int mmio_resource_enabled(struct pci_dev *pdev, int idx)
465 {
466 	return pci_resource_start(pdev, idx) && mmio_enabled(pdev);
467 }
468 
469 static void quirk_usb_handoff_ohci(struct pci_dev *pdev)
470 {
471 	void __iomem *base;
472 	u32 control;
473 	u32 fminterval;
474 	int cnt;
475 
476 	if (!mmio_resource_enabled(pdev, 0))
477 		return;
478 
479 	base = pci_ioremap_bar(pdev, 0);
480 	if (base == NULL)
481 		return;
482 
483 	control = readl(base + OHCI_CONTROL);
484 
485 /* On PA-RISC, PDC can leave IR set incorrectly; ignore it there. */
486 #ifdef __hppa__
487 #define	OHCI_CTRL_MASK		(OHCI_CTRL_RWC | OHCI_CTRL_IR)
488 #else
489 #define	OHCI_CTRL_MASK		OHCI_CTRL_RWC
490 
491 	if (control & OHCI_CTRL_IR) {
492 		int wait_time = 500; /* arbitrary; 5 seconds */
493 		writel(OHCI_INTR_OC, base + OHCI_INTRENABLE);
494 		writel(OHCI_OCR, base + OHCI_CMDSTATUS);
495 		while (wait_time > 0 &&
496 				readl(base + OHCI_CONTROL) & OHCI_CTRL_IR) {
497 			wait_time -= 10;
498 			msleep(10);
499 		}
500 		if (wait_time <= 0)
501 			dev_warn(&pdev->dev, "OHCI: BIOS handoff failed"
502 					" (BIOS bug?) %08x\n",
503 					readl(base + OHCI_CONTROL));
504 	}
505 #endif
506 
507 	/* disable interrupts */
508 	writel((u32) ~0, base + OHCI_INTRDISABLE);
509 
510 	/* Reset the USB bus, if the controller isn't already in RESET */
511 	if (control & OHCI_HCFS) {
512 		/* Go into RESET, preserving RWC (and possibly IR) */
513 		writel(control & OHCI_CTRL_MASK, base + OHCI_CONTROL);
514 		readl(base + OHCI_CONTROL);
515 
516 		/* drive bus reset for at least 50 ms (7.1.7.5) */
517 		msleep(50);
518 	}
519 
520 	/* software reset of the controller, preserving HcFmInterval */
521 	fminterval = readl(base + OHCI_FMINTERVAL);
522 	writel(OHCI_HCR, base + OHCI_CMDSTATUS);
523 
524 	/* reset requires max 10 us delay */
525 	for (cnt = 30; cnt > 0; --cnt) {	/* ... allow extra time */
526 		if ((readl(base + OHCI_CMDSTATUS) & OHCI_HCR) == 0)
527 			break;
528 		udelay(1);
529 	}
530 	writel(fminterval, base + OHCI_FMINTERVAL);
531 
532 	/* Now the controller is safely in SUSPEND and nothing can wake it up */
533 	iounmap(base);
534 }
535 
536 static const struct dmi_system_id ehci_dmi_nohandoff_table[] = {
537 	{
538 		/*  Pegatron Lucid (ExoPC) */
539 		.matches = {
540 			DMI_MATCH(DMI_BOARD_NAME, "EXOPG06411"),
541 			DMI_MATCH(DMI_BIOS_VERSION, "Lucid-CE-133"),
542 		},
543 	},
544 	{
545 		/*  Pegatron Lucid (Ordissimo AIRIS) */
546 		.matches = {
547 			DMI_MATCH(DMI_BOARD_NAME, "M11JB"),
548 			DMI_MATCH(DMI_BIOS_VERSION, "Lucid-"),
549 		},
550 	},
551 	{
552 		/*  Pegatron Lucid (Ordissimo) */
553 		.matches = {
554 			DMI_MATCH(DMI_BOARD_NAME, "Ordissimo"),
555 			DMI_MATCH(DMI_BIOS_VERSION, "Lucid-"),
556 		},
557 	},
558 	{ }
559 };
560 
561 static void ehci_bios_handoff(struct pci_dev *pdev,
562 					void __iomem *op_reg_base,
563 					u32 cap, u8 offset)
564 {
565 	int try_handoff = 1, tried_handoff = 0;
566 
567 	/* The Pegatron Lucid tablet sporadically waits for 98 seconds trying
568 	 * the handoff on its unused controller.  Skip it. */
569 	if (pdev->vendor == 0x8086 && pdev->device == 0x283a) {
570 		if (dmi_check_system(ehci_dmi_nohandoff_table))
571 			try_handoff = 0;
572 	}
573 
574 	if (try_handoff && (cap & EHCI_USBLEGSUP_BIOS)) {
575 		dev_dbg(&pdev->dev, "EHCI: BIOS handoff\n");
576 
577 #if 0
578 /* aleksey_gorelov@phoenix.com reports that some systems need SMI forced on,
579  * but that seems dubious in general (the BIOS left it off intentionally)
580  * and is known to prevent some systems from booting.  so we won't do this
581  * unless maybe we can determine when we're on a system that needs SMI forced.
582  */
583 		/* BIOS workaround (?): be sure the pre-Linux code
584 		 * receives the SMI
585 		 */
586 		pci_read_config_dword(pdev, offset + EHCI_USBLEGCTLSTS, &val);
587 		pci_write_config_dword(pdev, offset + EHCI_USBLEGCTLSTS,
588 				       val | EHCI_USBLEGCTLSTS_SOOE);
589 #endif
590 
591 		/* some systems get upset if this semaphore is
592 		 * set for any other reason than forcing a BIOS
593 		 * handoff..
594 		 */
595 		pci_write_config_byte(pdev, offset + 3, 1);
596 	}
597 
598 	/* if boot firmware now owns EHCI, spin till it hands it over. */
599 	if (try_handoff) {
600 		int msec = 1000;
601 		while ((cap & EHCI_USBLEGSUP_BIOS) && (msec > 0)) {
602 			tried_handoff = 1;
603 			msleep(10);
604 			msec -= 10;
605 			pci_read_config_dword(pdev, offset, &cap);
606 		}
607 	}
608 
609 	if (cap & EHCI_USBLEGSUP_BIOS) {
610 		/* well, possibly buggy BIOS... try to shut it down,
611 		 * and hope nothing goes too wrong
612 		 */
613 		if (try_handoff)
614 			dev_warn(&pdev->dev, "EHCI: BIOS handoff failed"
615 				 " (BIOS bug?) %08x\n", cap);
616 		pci_write_config_byte(pdev, offset + 2, 0);
617 	}
618 
619 	/* just in case, always disable EHCI SMIs */
620 	pci_write_config_dword(pdev, offset + EHCI_USBLEGCTLSTS, 0);
621 
622 	/* If the BIOS ever owned the controller then we can't expect
623 	 * any power sessions to remain intact.
624 	 */
625 	if (tried_handoff)
626 		writel(0, op_reg_base + EHCI_CONFIGFLAG);
627 }
628 
629 static void quirk_usb_disable_ehci(struct pci_dev *pdev)
630 {
631 	void __iomem *base, *op_reg_base;
632 	u32	hcc_params, cap, val;
633 	u8	offset, cap_length;
634 	int	wait_time, count = 256/4;
635 
636 	if (!mmio_resource_enabled(pdev, 0))
637 		return;
638 
639 	base = pci_ioremap_bar(pdev, 0);
640 	if (base == NULL)
641 		return;
642 
643 	cap_length = readb(base);
644 	op_reg_base = base + cap_length;
645 
646 	/* EHCI 0.96 and later may have "extended capabilities"
647 	 * spec section 5.1 explains the bios handoff, e.g. for
648 	 * booting from USB disk or using a usb keyboard
649 	 */
650 	hcc_params = readl(base + EHCI_HCC_PARAMS);
651 	offset = (hcc_params >> 8) & 0xff;
652 	while (offset && --count) {
653 		pci_read_config_dword(pdev, offset, &cap);
654 
655 		switch (cap & 0xff) {
656 		case 1:
657 			ehci_bios_handoff(pdev, op_reg_base, cap, offset);
658 			break;
659 		case 0: /* Illegal reserved cap, set cap=0 so we exit */
660 			cap = 0; /* then fallthrough... */
661 		default:
662 			dev_warn(&pdev->dev, "EHCI: unrecognized capability "
663 				 "%02x\n", cap & 0xff);
664 		}
665 		offset = (cap >> 8) & 0xff;
666 	}
667 	if (!count)
668 		dev_printk(KERN_DEBUG, &pdev->dev, "EHCI: capability loop?\n");
669 
670 	/*
671 	 * halt EHCI & disable its interrupts in any case
672 	 */
673 	val = readl(op_reg_base + EHCI_USBSTS);
674 	if ((val & EHCI_USBSTS_HALTED) == 0) {
675 		val = readl(op_reg_base + EHCI_USBCMD);
676 		val &= ~EHCI_USBCMD_RUN;
677 		writel(val, op_reg_base + EHCI_USBCMD);
678 
679 		wait_time = 2000;
680 		do {
681 			writel(0x3f, op_reg_base + EHCI_USBSTS);
682 			udelay(100);
683 			wait_time -= 100;
684 			val = readl(op_reg_base + EHCI_USBSTS);
685 			if ((val == ~(u32)0) || (val & EHCI_USBSTS_HALTED)) {
686 				break;
687 			}
688 		} while (wait_time > 0);
689 	}
690 	writel(0, op_reg_base + EHCI_USBINTR);
691 	writel(0x3f, op_reg_base + EHCI_USBSTS);
692 
693 	iounmap(base);
694 }
695 
696 /*
697  * handshake - spin reading a register until handshake completes
698  * @ptr: address of hc register to be read
699  * @mask: bits to look at in result of read
700  * @done: value of those bits when handshake succeeds
701  * @wait_usec: timeout in microseconds
702  * @delay_usec: delay in microseconds to wait between polling
703  *
704  * Polls a register every delay_usec microseconds.
705  * Returns 0 when the mask bits have the value done.
706  * Returns -ETIMEDOUT if this condition is not true after
707  * wait_usec microseconds have passed.
708  */
709 static int handshake(void __iomem *ptr, u32 mask, u32 done,
710 		int wait_usec, int delay_usec)
711 {
712 	u32	result;
713 
714 	do {
715 		result = readl(ptr);
716 		result &= mask;
717 		if (result == done)
718 			return 0;
719 		udelay(delay_usec);
720 		wait_usec -= delay_usec;
721 	} while (wait_usec > 0);
722 	return -ETIMEDOUT;
723 }
724 
725 #define PCI_DEVICE_ID_INTEL_LYNX_POINT_XHCI	0x8C31
726 #define PCI_DEVICE_ID_INTEL_LYNX_POINT_LP_XHCI	0x9C31
727 
728 bool usb_is_intel_ppt_switchable_xhci(struct pci_dev *pdev)
729 {
730 	return pdev->class == PCI_CLASS_SERIAL_USB_XHCI &&
731 		pdev->vendor == PCI_VENDOR_ID_INTEL &&
732 		pdev->device == PCI_DEVICE_ID_INTEL_PANTHERPOINT_XHCI;
733 }
734 
735 /* The Intel Lynx Point chipset also has switchable ports. */
736 bool usb_is_intel_lpt_switchable_xhci(struct pci_dev *pdev)
737 {
738 	return pdev->class == PCI_CLASS_SERIAL_USB_XHCI &&
739 		pdev->vendor == PCI_VENDOR_ID_INTEL &&
740 		(pdev->device == PCI_DEVICE_ID_INTEL_LYNX_POINT_XHCI ||
741 		 pdev->device == PCI_DEVICE_ID_INTEL_LYNX_POINT_LP_XHCI);
742 }
743 
744 bool usb_is_intel_switchable_xhci(struct pci_dev *pdev)
745 {
746 	return usb_is_intel_ppt_switchable_xhci(pdev) ||
747 		usb_is_intel_lpt_switchable_xhci(pdev);
748 }
749 EXPORT_SYMBOL_GPL(usb_is_intel_switchable_xhci);
750 
751 /*
752  * Intel's Panther Point chipset has two host controllers (EHCI and xHCI) that
753  * share some number of ports.  These ports can be switched between either
754  * controller.  Not all of the ports under the EHCI host controller may be
755  * switchable.
756  *
757  * The ports should be switched over to xHCI before PCI probes for any device
758  * start.  This avoids active devices under EHCI being disconnected during the
759  * port switchover, which could cause loss of data on USB storage devices, or
760  * failed boot when the root file system is on a USB mass storage device and is
761  * enumerated under EHCI first.
762  *
763  * We write into the xHC's PCI configuration space in some Intel-specific
764  * registers to switch the ports over.  The USB 3.0 terminations and the USB
765  * 2.0 data wires are switched separately.  We want to enable the SuperSpeed
766  * terminations before switching the USB 2.0 wires over, so that USB 3.0
767  * devices connect at SuperSpeed, rather than at USB 2.0 speeds.
768  */
769 void usb_enable_xhci_ports(struct pci_dev *xhci_pdev)
770 {
771 	u32		ports_available;
772 
773 	/* Don't switchover the ports if the user hasn't compiled the xHCI
774 	 * driver.  Otherwise they will see "dead" USB ports that don't power
775 	 * the devices.
776 	 */
777 	if (!IS_ENABLED(CONFIG_USB_XHCI_HCD)) {
778 		dev_warn(&xhci_pdev->dev,
779 				"CONFIG_USB_XHCI_HCD is turned off, "
780 				"defaulting to EHCI.\n");
781 		dev_warn(&xhci_pdev->dev,
782 				"USB 3.0 devices will work at USB 2.0 speeds.\n");
783 		return;
784 	}
785 
786 	/* Read USB3PRM, the USB 3.0 Port Routing Mask Register
787 	 * Indicate the ports that can be changed from OS.
788 	 */
789 	pci_read_config_dword(xhci_pdev, USB_INTEL_USB3PRM,
790 			&ports_available);
791 
792 	dev_dbg(&xhci_pdev->dev, "Configurable ports to enable SuperSpeed: 0x%x\n",
793 			ports_available);
794 
795 	/* Write USB3_PSSEN, the USB 3.0 Port SuperSpeed Enable
796 	 * Register, to turn on SuperSpeed terminations for the
797 	 * switchable ports.
798 	 */
799 	pci_write_config_dword(xhci_pdev, USB_INTEL_USB3_PSSEN,
800 			cpu_to_le32(ports_available));
801 
802 	pci_read_config_dword(xhci_pdev, USB_INTEL_USB3_PSSEN,
803 			&ports_available);
804 	dev_dbg(&xhci_pdev->dev, "USB 3.0 ports that are now enabled "
805 			"under xHCI: 0x%x\n", ports_available);
806 
807 	/* Read XUSB2PRM, xHCI USB 2.0 Port Routing Mask Register
808 	 * Indicate the USB 2.0 ports to be controlled by the xHCI host.
809 	 */
810 
811 	pci_read_config_dword(xhci_pdev, USB_INTEL_USB2PRM,
812 			&ports_available);
813 
814 	dev_dbg(&xhci_pdev->dev, "Configurable USB 2.0 ports to hand over to xCHI: 0x%x\n",
815 			ports_available);
816 
817 	/* Write XUSB2PR, the xHC USB 2.0 Port Routing Register, to
818 	 * switch the USB 2.0 power and data lines over to the xHCI
819 	 * host.
820 	 */
821 	pci_write_config_dword(xhci_pdev, USB_INTEL_XUSB2PR,
822 			cpu_to_le32(ports_available));
823 
824 	pci_read_config_dword(xhci_pdev, USB_INTEL_XUSB2PR,
825 			&ports_available);
826 	dev_dbg(&xhci_pdev->dev, "USB 2.0 ports that are now switched over "
827 			"to xHCI: 0x%x\n", ports_available);
828 }
829 EXPORT_SYMBOL_GPL(usb_enable_xhci_ports);
830 
831 void usb_disable_xhci_ports(struct pci_dev *xhci_pdev)
832 {
833 	pci_write_config_dword(xhci_pdev, USB_INTEL_USB3_PSSEN, 0x0);
834 	pci_write_config_dword(xhci_pdev, USB_INTEL_XUSB2PR, 0x0);
835 }
836 EXPORT_SYMBOL_GPL(usb_disable_xhci_ports);
837 
838 /**
839  * PCI Quirks for xHCI.
840  *
841  * Takes care of the handoff between the Pre-OS (i.e. BIOS) and the OS.
842  * It signals to the BIOS that the OS wants control of the host controller,
843  * and then waits 5 seconds for the BIOS to hand over control.
844  * If we timeout, assume the BIOS is broken and take control anyway.
845  */
846 static void quirk_usb_handoff_xhci(struct pci_dev *pdev)
847 {
848 	void __iomem *base;
849 	int ext_cap_offset;
850 	void __iomem *op_reg_base;
851 	u32 val;
852 	int timeout;
853 	int len = pci_resource_len(pdev, 0);
854 
855 	if (!mmio_resource_enabled(pdev, 0))
856 		return;
857 
858 	base = ioremap_nocache(pci_resource_start(pdev, 0), len);
859 	if (base == NULL)
860 		return;
861 
862 	/*
863 	 * Find the Legacy Support Capability register -
864 	 * this is optional for xHCI host controllers.
865 	 */
866 	ext_cap_offset = xhci_find_next_cap_offset(base, XHCI_HCC_PARAMS_OFFSET);
867 	do {
868 		if ((ext_cap_offset + sizeof(val)) > len) {
869 			/* We're reading garbage from the controller */
870 			dev_warn(&pdev->dev,
871 				 "xHCI controller failing to respond");
872 			return;
873 		}
874 
875 		if (!ext_cap_offset)
876 			/* We've reached the end of the extended capabilities */
877 			goto hc_init;
878 
879 		val = readl(base + ext_cap_offset);
880 		if (XHCI_EXT_CAPS_ID(val) == XHCI_EXT_CAPS_LEGACY)
881 			break;
882 		ext_cap_offset = xhci_find_next_cap_offset(base, ext_cap_offset);
883 	} while (1);
884 
885 	/* If the BIOS owns the HC, signal that the OS wants it, and wait */
886 	if (val & XHCI_HC_BIOS_OWNED) {
887 		writel(val | XHCI_HC_OS_OWNED, base + ext_cap_offset);
888 
889 		/* Wait for 5 seconds with 10 microsecond polling interval */
890 		timeout = handshake(base + ext_cap_offset, XHCI_HC_BIOS_OWNED,
891 				0, 5000, 10);
892 
893 		/* Assume a buggy BIOS and take HC ownership anyway */
894 		if (timeout) {
895 			dev_warn(&pdev->dev, "xHCI BIOS handoff failed"
896 					" (BIOS bug ?) %08x\n", val);
897 			writel(val & ~XHCI_HC_BIOS_OWNED, base + ext_cap_offset);
898 		}
899 	}
900 
901 	val = readl(base + ext_cap_offset + XHCI_LEGACY_CONTROL_OFFSET);
902 	/* Mask off (turn off) any enabled SMIs */
903 	val &= XHCI_LEGACY_DISABLE_SMI;
904 	/* Mask all SMI events bits, RW1C */
905 	val |= XHCI_LEGACY_SMI_EVENTS;
906 	/* Disable any BIOS SMIs and clear all SMI events*/
907 	writel(val, base + ext_cap_offset + XHCI_LEGACY_CONTROL_OFFSET);
908 
909 hc_init:
910 	if (usb_is_intel_switchable_xhci(pdev))
911 		usb_enable_xhci_ports(pdev);
912 
913 	op_reg_base = base + XHCI_HC_LENGTH(readl(base));
914 
915 	/* Wait for the host controller to be ready before writing any
916 	 * operational or runtime registers.  Wait 5 seconds and no more.
917 	 */
918 	timeout = handshake(op_reg_base + XHCI_STS_OFFSET, XHCI_STS_CNR, 0,
919 			5000, 10);
920 	/* Assume a buggy HC and start HC initialization anyway */
921 	if (timeout) {
922 		val = readl(op_reg_base + XHCI_STS_OFFSET);
923 		dev_warn(&pdev->dev,
924 				"xHCI HW not ready after 5 sec (HC bug?) "
925 				"status = 0x%x\n", val);
926 	}
927 
928 	/* Send the halt and disable interrupts command */
929 	val = readl(op_reg_base + XHCI_CMD_OFFSET);
930 	val &= ~(XHCI_CMD_RUN | XHCI_IRQS);
931 	writel(val, op_reg_base + XHCI_CMD_OFFSET);
932 
933 	/* Wait for the HC to halt - poll every 125 usec (one microframe). */
934 	timeout = handshake(op_reg_base + XHCI_STS_OFFSET, XHCI_STS_HALT, 1,
935 			XHCI_MAX_HALT_USEC, 125);
936 	if (timeout) {
937 		val = readl(op_reg_base + XHCI_STS_OFFSET);
938 		dev_warn(&pdev->dev,
939 				"xHCI HW did not halt within %d usec "
940 				"status = 0x%x\n", XHCI_MAX_HALT_USEC, val);
941 	}
942 
943 	iounmap(base);
944 }
945 
946 static void quirk_usb_early_handoff(struct pci_dev *pdev)
947 {
948 	/* Skip Netlogic mips SoC's internal PCI USB controller.
949 	 * This device does not need/support EHCI/OHCI handoff
950 	 */
951 	if (pdev->vendor == 0x184e)	/* vendor Netlogic */
952 		return;
953 	if (pdev->class != PCI_CLASS_SERIAL_USB_UHCI &&
954 			pdev->class != PCI_CLASS_SERIAL_USB_OHCI &&
955 			pdev->class != PCI_CLASS_SERIAL_USB_EHCI &&
956 			pdev->class != PCI_CLASS_SERIAL_USB_XHCI)
957 		return;
958 
959 	if (pci_enable_device(pdev) < 0) {
960 		dev_warn(&pdev->dev, "Can't enable PCI device, "
961 				"BIOS handoff failed.\n");
962 		return;
963 	}
964 	if (pdev->class == PCI_CLASS_SERIAL_USB_UHCI)
965 		quirk_usb_handoff_uhci(pdev);
966 	else if (pdev->class == PCI_CLASS_SERIAL_USB_OHCI)
967 		quirk_usb_handoff_ohci(pdev);
968 	else if (pdev->class == PCI_CLASS_SERIAL_USB_EHCI)
969 		quirk_usb_disable_ehci(pdev);
970 	else if (pdev->class == PCI_CLASS_SERIAL_USB_XHCI)
971 		quirk_usb_handoff_xhci(pdev);
972 	pci_disable_device(pdev);
973 }
974 DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_ANY_ID, PCI_ANY_ID,
975 			PCI_CLASS_SERIAL_USB, 8, quirk_usb_early_handoff);
976