xref: /openbmc/linux/drivers/usb/host/pci-quirks.c (revision e23feb16)
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 void sb800_prefetch(struct device *dev, int on)
95 {
96 	u16 misc;
97 	struct pci_dev *pdev = to_pci_dev(dev);
98 
99 	pci_read_config_word(pdev, 0x50, &misc);
100 	if (on == 0)
101 		pci_write_config_word(pdev, 0x50, misc & 0xfcff);
102 	else
103 		pci_write_config_word(pdev, 0x50, misc | 0x0300);
104 }
105 EXPORT_SYMBOL_GPL(sb800_prefetch);
106 
107 int usb_amd_find_chipset_info(void)
108 {
109 	u8 rev = 0;
110 	unsigned long flags;
111 	struct amd_chipset_info info;
112 	int ret;
113 
114 	spin_lock_irqsave(&amd_lock, flags);
115 
116 	/* probe only once */
117 	if (amd_chipset.probe_count > 0) {
118 		amd_chipset.probe_count++;
119 		spin_unlock_irqrestore(&amd_lock, flags);
120 		return amd_chipset.probe_result;
121 	}
122 	memset(&info, 0, sizeof(info));
123 	spin_unlock_irqrestore(&amd_lock, flags);
124 
125 	info.smbus_dev = pci_get_device(PCI_VENDOR_ID_ATI, 0x4385, NULL);
126 	if (info.smbus_dev) {
127 		rev = info.smbus_dev->revision;
128 		if (rev >= 0x40)
129 			info.sb_type = 1;
130 		else if (rev >= 0x30 && rev <= 0x3b)
131 			info.sb_type = 3;
132 	} else {
133 		info.smbus_dev = pci_get_device(PCI_VENDOR_ID_AMD,
134 						0x780b, NULL);
135 		if (!info.smbus_dev) {
136 			ret = 0;
137 			goto commit;
138 		}
139 
140 		rev = info.smbus_dev->revision;
141 		if (rev >= 0x11 && rev <= 0x18)
142 			info.sb_type = 2;
143 	}
144 
145 	if (info.sb_type == 0) {
146 		if (info.smbus_dev) {
147 			pci_dev_put(info.smbus_dev);
148 			info.smbus_dev = NULL;
149 		}
150 		ret = 0;
151 		goto commit;
152 	}
153 
154 	info.nb_dev = pci_get_device(PCI_VENDOR_ID_AMD, 0x9601, NULL);
155 	if (info.nb_dev) {
156 		info.nb_type = 1;
157 	} else {
158 		info.nb_dev = pci_get_device(PCI_VENDOR_ID_AMD, 0x1510, NULL);
159 		if (info.nb_dev) {
160 			info.nb_type = 2;
161 		} else {
162 			info.nb_dev = pci_get_device(PCI_VENDOR_ID_AMD,
163 						     0x9600, NULL);
164 			if (info.nb_dev)
165 				info.nb_type = 3;
166 		}
167 	}
168 
169 	ret = info.probe_result = 1;
170 	printk(KERN_DEBUG "QUIRK: Enable AMD PLL fix\n");
171 
172 commit:
173 
174 	spin_lock_irqsave(&amd_lock, flags);
175 	if (amd_chipset.probe_count > 0) {
176 		/* race - someone else was faster - drop devices */
177 
178 		/* Mark that we where here */
179 		amd_chipset.probe_count++;
180 		ret = amd_chipset.probe_result;
181 
182 		spin_unlock_irqrestore(&amd_lock, flags);
183 
184 		if (info.nb_dev)
185 			pci_dev_put(info.nb_dev);
186 		if (info.smbus_dev)
187 			pci_dev_put(info.smbus_dev);
188 
189 	} else {
190 		/* no race - commit the result */
191 		info.probe_count++;
192 		amd_chipset = info;
193 		spin_unlock_irqrestore(&amd_lock, flags);
194 	}
195 
196 	return ret;
197 }
198 EXPORT_SYMBOL_GPL(usb_amd_find_chipset_info);
199 
200 /*
201  * The hardware normally enables the A-link power management feature, which
202  * lets the system lower the power consumption in idle states.
203  *
204  * This USB quirk prevents the link going into that lower power state
205  * during isochronous transfers.
206  *
207  * Without this quirk, isochronous stream on OHCI/EHCI/xHCI controllers of
208  * some AMD platforms may stutter or have breaks occasionally.
209  */
210 static void usb_amd_quirk_pll(int disable)
211 {
212 	u32 addr, addr_low, addr_high, val;
213 	u32 bit = disable ? 0 : 1;
214 	unsigned long flags;
215 
216 	spin_lock_irqsave(&amd_lock, flags);
217 
218 	if (disable) {
219 		amd_chipset.isoc_reqs++;
220 		if (amd_chipset.isoc_reqs > 1) {
221 			spin_unlock_irqrestore(&amd_lock, flags);
222 			return;
223 		}
224 	} else {
225 		amd_chipset.isoc_reqs--;
226 		if (amd_chipset.isoc_reqs > 0) {
227 			spin_unlock_irqrestore(&amd_lock, flags);
228 			return;
229 		}
230 	}
231 
232 	if (amd_chipset.sb_type == 1 || amd_chipset.sb_type == 2) {
233 		outb_p(AB_REG_BAR_LOW, 0xcd6);
234 		addr_low = inb_p(0xcd7);
235 		outb_p(AB_REG_BAR_HIGH, 0xcd6);
236 		addr_high = inb_p(0xcd7);
237 		addr = addr_high << 8 | addr_low;
238 
239 		outl_p(0x30, AB_INDX(addr));
240 		outl_p(0x40, AB_DATA(addr));
241 		outl_p(0x34, AB_INDX(addr));
242 		val = inl_p(AB_DATA(addr));
243 	} else if (amd_chipset.sb_type == 3) {
244 		pci_read_config_dword(amd_chipset.smbus_dev,
245 					AB_REG_BAR_SB700, &addr);
246 		outl(AX_INDXC, AB_INDX(addr));
247 		outl(0x40, AB_DATA(addr));
248 		outl(AX_DATAC, AB_INDX(addr));
249 		val = inl(AB_DATA(addr));
250 	} else {
251 		spin_unlock_irqrestore(&amd_lock, flags);
252 		return;
253 	}
254 
255 	if (disable) {
256 		val &= ~0x08;
257 		val |= (1 << 4) | (1 << 9);
258 	} else {
259 		val |= 0x08;
260 		val &= ~((1 << 4) | (1 << 9));
261 	}
262 	outl_p(val, AB_DATA(addr));
263 
264 	if (!amd_chipset.nb_dev) {
265 		spin_unlock_irqrestore(&amd_lock, flags);
266 		return;
267 	}
268 
269 	if (amd_chipset.nb_type == 1 || amd_chipset.nb_type == 3) {
270 		addr = PCIE_P_CNTL;
271 		pci_write_config_dword(amd_chipset.nb_dev,
272 					NB_PCIE_INDX_ADDR, addr);
273 		pci_read_config_dword(amd_chipset.nb_dev,
274 					NB_PCIE_INDX_DATA, &val);
275 
276 		val &= ~(1 | (1 << 3) | (1 << 4) | (1 << 9) | (1 << 12));
277 		val |= bit | (bit << 3) | (bit << 12);
278 		val |= ((!bit) << 4) | ((!bit) << 9);
279 		pci_write_config_dword(amd_chipset.nb_dev,
280 					NB_PCIE_INDX_DATA, val);
281 
282 		addr = BIF_NB;
283 		pci_write_config_dword(amd_chipset.nb_dev,
284 					NB_PCIE_INDX_ADDR, addr);
285 		pci_read_config_dword(amd_chipset.nb_dev,
286 					NB_PCIE_INDX_DATA, &val);
287 		val &= ~(1 << 8);
288 		val |= bit << 8;
289 
290 		pci_write_config_dword(amd_chipset.nb_dev,
291 					NB_PCIE_INDX_DATA, val);
292 	} else if (amd_chipset.nb_type == 2) {
293 		addr = NB_PIF0_PWRDOWN_0;
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 		addr = NB_PIF0_PWRDOWN_1;
307 		pci_write_config_dword(amd_chipset.nb_dev,
308 					NB_PCIE_INDX_ADDR, addr);
309 		pci_read_config_dword(amd_chipset.nb_dev,
310 					NB_PCIE_INDX_DATA, &val);
311 		if (disable)
312 			val &= ~(0x3f << 7);
313 		else
314 			val |= 0x3f << 7;
315 
316 		pci_write_config_dword(amd_chipset.nb_dev,
317 					NB_PCIE_INDX_DATA, val);
318 	}
319 
320 	spin_unlock_irqrestore(&amd_lock, flags);
321 	return;
322 }
323 
324 void usb_amd_quirk_pll_disable(void)
325 {
326 	usb_amd_quirk_pll(1);
327 }
328 EXPORT_SYMBOL_GPL(usb_amd_quirk_pll_disable);
329 
330 void usb_amd_quirk_pll_enable(void)
331 {
332 	usb_amd_quirk_pll(0);
333 }
334 EXPORT_SYMBOL_GPL(usb_amd_quirk_pll_enable);
335 
336 void usb_amd_dev_put(void)
337 {
338 	struct pci_dev *nb, *smbus;
339 	unsigned long flags;
340 
341 	spin_lock_irqsave(&amd_lock, flags);
342 
343 	amd_chipset.probe_count--;
344 	if (amd_chipset.probe_count > 0) {
345 		spin_unlock_irqrestore(&amd_lock, flags);
346 		return;
347 	}
348 
349 	/* save them to pci_dev_put outside of spinlock */
350 	nb    = amd_chipset.nb_dev;
351 	smbus = amd_chipset.smbus_dev;
352 
353 	amd_chipset.nb_dev = NULL;
354 	amd_chipset.smbus_dev = NULL;
355 	amd_chipset.nb_type = 0;
356 	amd_chipset.sb_type = 0;
357 	amd_chipset.isoc_reqs = 0;
358 	amd_chipset.probe_result = 0;
359 
360 	spin_unlock_irqrestore(&amd_lock, flags);
361 
362 	if (nb)
363 		pci_dev_put(nb);
364 	if (smbus)
365 		pci_dev_put(smbus);
366 }
367 EXPORT_SYMBOL_GPL(usb_amd_dev_put);
368 
369 /*
370  * Make sure the controller is completely inactive, unable to
371  * generate interrupts or do DMA.
372  */
373 void uhci_reset_hc(struct pci_dev *pdev, unsigned long base)
374 {
375 	/* Turn off PIRQ enable and SMI enable.  (This also turns off the
376 	 * BIOS's USB Legacy Support.)  Turn off all the R/WC bits too.
377 	 */
378 	pci_write_config_word(pdev, UHCI_USBLEGSUP, UHCI_USBLEGSUP_RWC);
379 
380 	/* Reset the HC - this will force us to get a
381 	 * new notification of any already connected
382 	 * ports due to the virtual disconnect that it
383 	 * implies.
384 	 */
385 	outw(UHCI_USBCMD_HCRESET, base + UHCI_USBCMD);
386 	mb();
387 	udelay(5);
388 	if (inw(base + UHCI_USBCMD) & UHCI_USBCMD_HCRESET)
389 		dev_warn(&pdev->dev, "HCRESET not completed yet!\n");
390 
391 	/* Just to be safe, disable interrupt requests and
392 	 * make sure the controller is stopped.
393 	 */
394 	outw(0, base + UHCI_USBINTR);
395 	outw(0, base + UHCI_USBCMD);
396 }
397 EXPORT_SYMBOL_GPL(uhci_reset_hc);
398 
399 /*
400  * Initialize a controller that was newly discovered or has just been
401  * resumed.  In either case we can't be sure of its previous state.
402  *
403  * Returns: 1 if the controller was reset, 0 otherwise.
404  */
405 int uhci_check_and_reset_hc(struct pci_dev *pdev, unsigned long base)
406 {
407 	u16 legsup;
408 	unsigned int cmd, intr;
409 
410 	/*
411 	 * When restarting a suspended controller, we expect all the
412 	 * settings to be the same as we left them:
413 	 *
414 	 *	PIRQ and SMI disabled, no R/W bits set in USBLEGSUP;
415 	 *	Controller is stopped and configured with EGSM set;
416 	 *	No interrupts enabled except possibly Resume Detect.
417 	 *
418 	 * If any of these conditions are violated we do a complete reset.
419 	 */
420 	pci_read_config_word(pdev, UHCI_USBLEGSUP, &legsup);
421 	if (legsup & ~(UHCI_USBLEGSUP_RO | UHCI_USBLEGSUP_RWC)) {
422 		dev_dbg(&pdev->dev, "%s: legsup = 0x%04x\n",
423 				__func__, legsup);
424 		goto reset_needed;
425 	}
426 
427 	cmd = inw(base + UHCI_USBCMD);
428 	if ((cmd & UHCI_USBCMD_RUN) || !(cmd & UHCI_USBCMD_CONFIGURE) ||
429 			!(cmd & UHCI_USBCMD_EGSM)) {
430 		dev_dbg(&pdev->dev, "%s: cmd = 0x%04x\n",
431 				__func__, cmd);
432 		goto reset_needed;
433 	}
434 
435 	intr = inw(base + UHCI_USBINTR);
436 	if (intr & (~UHCI_USBINTR_RESUME)) {
437 		dev_dbg(&pdev->dev, "%s: intr = 0x%04x\n",
438 				__func__, intr);
439 		goto reset_needed;
440 	}
441 	return 0;
442 
443 reset_needed:
444 	dev_dbg(&pdev->dev, "Performing full reset\n");
445 	uhci_reset_hc(pdev, base);
446 	return 1;
447 }
448 EXPORT_SYMBOL_GPL(uhci_check_and_reset_hc);
449 
450 static inline int io_type_enabled(struct pci_dev *pdev, unsigned int mask)
451 {
452 	u16 cmd;
453 	return !pci_read_config_word(pdev, PCI_COMMAND, &cmd) && (cmd & mask);
454 }
455 
456 #define pio_enabled(dev) io_type_enabled(dev, PCI_COMMAND_IO)
457 #define mmio_enabled(dev) io_type_enabled(dev, PCI_COMMAND_MEMORY)
458 
459 static void quirk_usb_handoff_uhci(struct pci_dev *pdev)
460 {
461 	unsigned long base = 0;
462 	int i;
463 
464 	if (!pio_enabled(pdev))
465 		return;
466 
467 	for (i = 0; i < PCI_ROM_RESOURCE; i++)
468 		if ((pci_resource_flags(pdev, i) & IORESOURCE_IO)) {
469 			base = pci_resource_start(pdev, i);
470 			break;
471 		}
472 
473 	if (base)
474 		uhci_check_and_reset_hc(pdev, base);
475 }
476 
477 static int mmio_resource_enabled(struct pci_dev *pdev, int idx)
478 {
479 	return pci_resource_start(pdev, idx) && mmio_enabled(pdev);
480 }
481 
482 static void quirk_usb_handoff_ohci(struct pci_dev *pdev)
483 {
484 	void __iomem *base;
485 	u32 control;
486 	u32 fminterval;
487 	int cnt;
488 
489 	if (!mmio_resource_enabled(pdev, 0))
490 		return;
491 
492 	base = pci_ioremap_bar(pdev, 0);
493 	if (base == NULL)
494 		return;
495 
496 	control = readl(base + OHCI_CONTROL);
497 
498 /* On PA-RISC, PDC can leave IR set incorrectly; ignore it there. */
499 #ifdef __hppa__
500 #define	OHCI_CTRL_MASK		(OHCI_CTRL_RWC | OHCI_CTRL_IR)
501 #else
502 #define	OHCI_CTRL_MASK		OHCI_CTRL_RWC
503 
504 	if (control & OHCI_CTRL_IR) {
505 		int wait_time = 500; /* arbitrary; 5 seconds */
506 		writel(OHCI_INTR_OC, base + OHCI_INTRENABLE);
507 		writel(OHCI_OCR, base + OHCI_CMDSTATUS);
508 		while (wait_time > 0 &&
509 				readl(base + OHCI_CONTROL) & OHCI_CTRL_IR) {
510 			wait_time -= 10;
511 			msleep(10);
512 		}
513 		if (wait_time <= 0)
514 			dev_warn(&pdev->dev, "OHCI: BIOS handoff failed"
515 					" (BIOS bug?) %08x\n",
516 					readl(base + OHCI_CONTROL));
517 	}
518 #endif
519 
520 	/* disable interrupts */
521 	writel((u32) ~0, base + OHCI_INTRDISABLE);
522 
523 	/* Reset the USB bus, if the controller isn't already in RESET */
524 	if (control & OHCI_HCFS) {
525 		/* Go into RESET, preserving RWC (and possibly IR) */
526 		writel(control & OHCI_CTRL_MASK, base + OHCI_CONTROL);
527 		readl(base + OHCI_CONTROL);
528 
529 		/* drive bus reset for at least 50 ms (7.1.7.5) */
530 		msleep(50);
531 	}
532 
533 	/* software reset of the controller, preserving HcFmInterval */
534 	fminterval = readl(base + OHCI_FMINTERVAL);
535 	writel(OHCI_HCR, base + OHCI_CMDSTATUS);
536 
537 	/* reset requires max 10 us delay */
538 	for (cnt = 30; cnt > 0; --cnt) {	/* ... allow extra time */
539 		if ((readl(base + OHCI_CMDSTATUS) & OHCI_HCR) == 0)
540 			break;
541 		udelay(1);
542 	}
543 	writel(fminterval, base + OHCI_FMINTERVAL);
544 
545 	/* Now the controller is safely in SUSPEND and nothing can wake it up */
546 	iounmap(base);
547 }
548 
549 static const struct dmi_system_id ehci_dmi_nohandoff_table[] = {
550 	{
551 		/*  Pegatron Lucid (ExoPC) */
552 		.matches = {
553 			DMI_MATCH(DMI_BOARD_NAME, "EXOPG06411"),
554 			DMI_MATCH(DMI_BIOS_VERSION, "Lucid-CE-133"),
555 		},
556 	},
557 	{
558 		/*  Pegatron Lucid (Ordissimo AIRIS) */
559 		.matches = {
560 			DMI_MATCH(DMI_BOARD_NAME, "M11JB"),
561 			DMI_MATCH(DMI_BIOS_VERSION, "Lucid-"),
562 		},
563 	},
564 	{
565 		/*  Pegatron Lucid (Ordissimo) */
566 		.matches = {
567 			DMI_MATCH(DMI_BOARD_NAME, "Ordissimo"),
568 			DMI_MATCH(DMI_BIOS_VERSION, "Lucid-"),
569 		},
570 	},
571 	{ }
572 };
573 
574 static void ehci_bios_handoff(struct pci_dev *pdev,
575 					void __iomem *op_reg_base,
576 					u32 cap, u8 offset)
577 {
578 	int try_handoff = 1, tried_handoff = 0;
579 
580 	/* The Pegatron Lucid tablet sporadically waits for 98 seconds trying
581 	 * the handoff on its unused controller.  Skip it. */
582 	if (pdev->vendor == 0x8086 && pdev->device == 0x283a) {
583 		if (dmi_check_system(ehci_dmi_nohandoff_table))
584 			try_handoff = 0;
585 	}
586 
587 	if (try_handoff && (cap & EHCI_USBLEGSUP_BIOS)) {
588 		dev_dbg(&pdev->dev, "EHCI: BIOS handoff\n");
589 
590 #if 0
591 /* aleksey_gorelov@phoenix.com reports that some systems need SMI forced on,
592  * but that seems dubious in general (the BIOS left it off intentionally)
593  * and is known to prevent some systems from booting.  so we won't do this
594  * unless maybe we can determine when we're on a system that needs SMI forced.
595  */
596 		/* BIOS workaround (?): be sure the pre-Linux code
597 		 * receives the SMI
598 		 */
599 		pci_read_config_dword(pdev, offset + EHCI_USBLEGCTLSTS, &val);
600 		pci_write_config_dword(pdev, offset + EHCI_USBLEGCTLSTS,
601 				       val | EHCI_USBLEGCTLSTS_SOOE);
602 #endif
603 
604 		/* some systems get upset if this semaphore is
605 		 * set for any other reason than forcing a BIOS
606 		 * handoff..
607 		 */
608 		pci_write_config_byte(pdev, offset + 3, 1);
609 	}
610 
611 	/* if boot firmware now owns EHCI, spin till it hands it over. */
612 	if (try_handoff) {
613 		int msec = 1000;
614 		while ((cap & EHCI_USBLEGSUP_BIOS) && (msec > 0)) {
615 			tried_handoff = 1;
616 			msleep(10);
617 			msec -= 10;
618 			pci_read_config_dword(pdev, offset, &cap);
619 		}
620 	}
621 
622 	if (cap & EHCI_USBLEGSUP_BIOS) {
623 		/* well, possibly buggy BIOS... try to shut it down,
624 		 * and hope nothing goes too wrong
625 		 */
626 		if (try_handoff)
627 			dev_warn(&pdev->dev, "EHCI: BIOS handoff failed"
628 				 " (BIOS bug?) %08x\n", cap);
629 		pci_write_config_byte(pdev, offset + 2, 0);
630 	}
631 
632 	/* just in case, always disable EHCI SMIs */
633 	pci_write_config_dword(pdev, offset + EHCI_USBLEGCTLSTS, 0);
634 
635 	/* If the BIOS ever owned the controller then we can't expect
636 	 * any power sessions to remain intact.
637 	 */
638 	if (tried_handoff)
639 		writel(0, op_reg_base + EHCI_CONFIGFLAG);
640 }
641 
642 static void quirk_usb_disable_ehci(struct pci_dev *pdev)
643 {
644 	void __iomem *base, *op_reg_base;
645 	u32	hcc_params, cap, val;
646 	u8	offset, cap_length;
647 	int	wait_time, count = 256/4;
648 
649 	if (!mmio_resource_enabled(pdev, 0))
650 		return;
651 
652 	base = pci_ioremap_bar(pdev, 0);
653 	if (base == NULL)
654 		return;
655 
656 	cap_length = readb(base);
657 	op_reg_base = base + cap_length;
658 
659 	/* EHCI 0.96 and later may have "extended capabilities"
660 	 * spec section 5.1 explains the bios handoff, e.g. for
661 	 * booting from USB disk or using a usb keyboard
662 	 */
663 	hcc_params = readl(base + EHCI_HCC_PARAMS);
664 	offset = (hcc_params >> 8) & 0xff;
665 	while (offset && --count) {
666 		pci_read_config_dword(pdev, offset, &cap);
667 
668 		switch (cap & 0xff) {
669 		case 1:
670 			ehci_bios_handoff(pdev, op_reg_base, cap, offset);
671 			break;
672 		case 0: /* Illegal reserved cap, set cap=0 so we exit */
673 			cap = 0; /* then fallthrough... */
674 		default:
675 			dev_warn(&pdev->dev, "EHCI: unrecognized capability "
676 				 "%02x\n", cap & 0xff);
677 		}
678 		offset = (cap >> 8) & 0xff;
679 	}
680 	if (!count)
681 		dev_printk(KERN_DEBUG, &pdev->dev, "EHCI: capability loop?\n");
682 
683 	/*
684 	 * halt EHCI & disable its interrupts in any case
685 	 */
686 	val = readl(op_reg_base + EHCI_USBSTS);
687 	if ((val & EHCI_USBSTS_HALTED) == 0) {
688 		val = readl(op_reg_base + EHCI_USBCMD);
689 		val &= ~EHCI_USBCMD_RUN;
690 		writel(val, op_reg_base + EHCI_USBCMD);
691 
692 		wait_time = 2000;
693 		do {
694 			writel(0x3f, op_reg_base + EHCI_USBSTS);
695 			udelay(100);
696 			wait_time -= 100;
697 			val = readl(op_reg_base + EHCI_USBSTS);
698 			if ((val == ~(u32)0) || (val & EHCI_USBSTS_HALTED)) {
699 				break;
700 			}
701 		} while (wait_time > 0);
702 	}
703 	writel(0, op_reg_base + EHCI_USBINTR);
704 	writel(0x3f, op_reg_base + EHCI_USBSTS);
705 
706 	iounmap(base);
707 }
708 
709 /*
710  * handshake - spin reading a register until handshake completes
711  * @ptr: address of hc register to be read
712  * @mask: bits to look at in result of read
713  * @done: value of those bits when handshake succeeds
714  * @wait_usec: timeout in microseconds
715  * @delay_usec: delay in microseconds to wait between polling
716  *
717  * Polls a register every delay_usec microseconds.
718  * Returns 0 when the mask bits have the value done.
719  * Returns -ETIMEDOUT if this condition is not true after
720  * wait_usec microseconds have passed.
721  */
722 static int handshake(void __iomem *ptr, u32 mask, u32 done,
723 		int wait_usec, int delay_usec)
724 {
725 	u32	result;
726 
727 	do {
728 		result = readl(ptr);
729 		result &= mask;
730 		if (result == done)
731 			return 0;
732 		udelay(delay_usec);
733 		wait_usec -= delay_usec;
734 	} while (wait_usec > 0);
735 	return -ETIMEDOUT;
736 }
737 
738 /*
739  * Intel's Panther Point chipset has two host controllers (EHCI and xHCI) that
740  * share some number of ports.  These ports can be switched between either
741  * controller.  Not all of the ports under the EHCI host controller may be
742  * switchable.
743  *
744  * The ports should be switched over to xHCI before PCI probes for any device
745  * start.  This avoids active devices under EHCI being disconnected during the
746  * port switchover, which could cause loss of data on USB storage devices, or
747  * failed boot when the root file system is on a USB mass storage device and is
748  * enumerated under EHCI first.
749  *
750  * We write into the xHC's PCI configuration space in some Intel-specific
751  * registers to switch the ports over.  The USB 3.0 terminations and the USB
752  * 2.0 data wires are switched separately.  We want to enable the SuperSpeed
753  * terminations before switching the USB 2.0 wires over, so that USB 3.0
754  * devices connect at SuperSpeed, rather than at USB 2.0 speeds.
755  */
756 void usb_enable_intel_xhci_ports(struct pci_dev *xhci_pdev)
757 {
758 	u32		ports_available;
759 	bool		ehci_found = false;
760 	struct pci_dev	*companion = NULL;
761 
762 	/* make sure an intel EHCI controller exists */
763 	for_each_pci_dev(companion) {
764 		if (companion->class == PCI_CLASS_SERIAL_USB_EHCI &&
765 		    companion->vendor == PCI_VENDOR_ID_INTEL) {
766 			ehci_found = true;
767 			break;
768 		}
769 	}
770 
771 	if (!ehci_found)
772 		return;
773 
774 	/* Don't switchover the ports if the user hasn't compiled the xHCI
775 	 * driver.  Otherwise they will see "dead" USB ports that don't power
776 	 * the devices.
777 	 */
778 	if (!IS_ENABLED(CONFIG_USB_XHCI_HCD)) {
779 		dev_warn(&xhci_pdev->dev,
780 				"CONFIG_USB_XHCI_HCD is turned off, "
781 				"defaulting to EHCI.\n");
782 		dev_warn(&xhci_pdev->dev,
783 				"USB 3.0 devices will work at USB 2.0 speeds.\n");
784 		usb_disable_xhci_ports(xhci_pdev);
785 		return;
786 	}
787 
788 	/* Read USB3PRM, the USB 3.0 Port Routing Mask Register
789 	 * Indicate the ports that can be changed from OS.
790 	 */
791 	pci_read_config_dword(xhci_pdev, USB_INTEL_USB3PRM,
792 			&ports_available);
793 
794 	dev_dbg(&xhci_pdev->dev, "Configurable ports to enable SuperSpeed: 0x%x\n",
795 			ports_available);
796 
797 	/* Write USB3_PSSEN, the USB 3.0 Port SuperSpeed Enable
798 	 * Register, to turn on SuperSpeed terminations for the
799 	 * switchable ports.
800 	 */
801 	pci_write_config_dword(xhci_pdev, USB_INTEL_USB3_PSSEN,
802 			cpu_to_le32(ports_available));
803 
804 	pci_read_config_dword(xhci_pdev, USB_INTEL_USB3_PSSEN,
805 			&ports_available);
806 	dev_dbg(&xhci_pdev->dev, "USB 3.0 ports that are now enabled "
807 			"under xHCI: 0x%x\n", ports_available);
808 
809 	/* Read XUSB2PRM, xHCI USB 2.0 Port Routing Mask Register
810 	 * Indicate the USB 2.0 ports to be controlled by the xHCI host.
811 	 */
812 
813 	pci_read_config_dword(xhci_pdev, USB_INTEL_USB2PRM,
814 			&ports_available);
815 
816 	dev_dbg(&xhci_pdev->dev, "Configurable USB 2.0 ports to hand over to xCHI: 0x%x\n",
817 			ports_available);
818 
819 	/* Write XUSB2PR, the xHC USB 2.0 Port Routing Register, to
820 	 * switch the USB 2.0 power and data lines over to the xHCI
821 	 * host.
822 	 */
823 	pci_write_config_dword(xhci_pdev, USB_INTEL_XUSB2PR,
824 			cpu_to_le32(ports_available));
825 
826 	pci_read_config_dword(xhci_pdev, USB_INTEL_XUSB2PR,
827 			&ports_available);
828 	dev_dbg(&xhci_pdev->dev, "USB 2.0 ports that are now switched over "
829 			"to xHCI: 0x%x\n", ports_available);
830 }
831 EXPORT_SYMBOL_GPL(usb_enable_intel_xhci_ports);
832 
833 void usb_disable_xhci_ports(struct pci_dev *xhci_pdev)
834 {
835 	pci_write_config_dword(xhci_pdev, USB_INTEL_USB3_PSSEN, 0x0);
836 	pci_write_config_dword(xhci_pdev, USB_INTEL_XUSB2PR, 0x0);
837 }
838 EXPORT_SYMBOL_GPL(usb_disable_xhci_ports);
839 
840 /**
841  * PCI Quirks for xHCI.
842  *
843  * Takes care of the handoff between the Pre-OS (i.e. BIOS) and the OS.
844  * It signals to the BIOS that the OS wants control of the host controller,
845  * and then waits 5 seconds for the BIOS to hand over control.
846  * If we timeout, assume the BIOS is broken and take control anyway.
847  */
848 static void quirk_usb_handoff_xhci(struct pci_dev *pdev)
849 {
850 	void __iomem *base;
851 	int ext_cap_offset;
852 	void __iomem *op_reg_base;
853 	u32 val;
854 	int timeout;
855 	int len = pci_resource_len(pdev, 0);
856 
857 	if (!mmio_resource_enabled(pdev, 0))
858 		return;
859 
860 	base = ioremap_nocache(pci_resource_start(pdev, 0), len);
861 	if (base == NULL)
862 		return;
863 
864 	/*
865 	 * Find the Legacy Support Capability register -
866 	 * this is optional for xHCI host controllers.
867 	 */
868 	ext_cap_offset = xhci_find_next_cap_offset(base, XHCI_HCC_PARAMS_OFFSET);
869 	do {
870 		if ((ext_cap_offset + sizeof(val)) > len) {
871 			/* We're reading garbage from the controller */
872 			dev_warn(&pdev->dev,
873 				 "xHCI controller failing to respond");
874 			return;
875 		}
876 
877 		if (!ext_cap_offset)
878 			/* We've reached the end of the extended capabilities */
879 			goto hc_init;
880 
881 		val = readl(base + ext_cap_offset);
882 		if (XHCI_EXT_CAPS_ID(val) == XHCI_EXT_CAPS_LEGACY)
883 			break;
884 		ext_cap_offset = xhci_find_next_cap_offset(base, ext_cap_offset);
885 	} while (1);
886 
887 	/* If the BIOS owns the HC, signal that the OS wants it, and wait */
888 	if (val & XHCI_HC_BIOS_OWNED) {
889 		writel(val | XHCI_HC_OS_OWNED, base + ext_cap_offset);
890 
891 		/* Wait for 5 seconds with 10 microsecond polling interval */
892 		timeout = handshake(base + ext_cap_offset, XHCI_HC_BIOS_OWNED,
893 				0, 5000, 10);
894 
895 		/* Assume a buggy BIOS and take HC ownership anyway */
896 		if (timeout) {
897 			dev_warn(&pdev->dev, "xHCI BIOS handoff failed"
898 					" (BIOS bug ?) %08x\n", val);
899 			writel(val & ~XHCI_HC_BIOS_OWNED, base + ext_cap_offset);
900 		}
901 	}
902 
903 	val = readl(base + ext_cap_offset + XHCI_LEGACY_CONTROL_OFFSET);
904 	/* Mask off (turn off) any enabled SMIs */
905 	val &= XHCI_LEGACY_DISABLE_SMI;
906 	/* Mask all SMI events bits, RW1C */
907 	val |= XHCI_LEGACY_SMI_EVENTS;
908 	/* Disable any BIOS SMIs and clear all SMI events*/
909 	writel(val, base + ext_cap_offset + XHCI_LEGACY_CONTROL_OFFSET);
910 
911 hc_init:
912 	if (pdev->vendor == PCI_VENDOR_ID_INTEL)
913 		usb_enable_intel_xhci_ports(pdev);
914 
915 	op_reg_base = base + XHCI_HC_LENGTH(readl(base));
916 
917 	/* Wait for the host controller to be ready before writing any
918 	 * operational or runtime registers.  Wait 5 seconds and no more.
919 	 */
920 	timeout = handshake(op_reg_base + XHCI_STS_OFFSET, XHCI_STS_CNR, 0,
921 			5000, 10);
922 	/* Assume a buggy HC and start HC initialization anyway */
923 	if (timeout) {
924 		val = readl(op_reg_base + XHCI_STS_OFFSET);
925 		dev_warn(&pdev->dev,
926 				"xHCI HW not ready after 5 sec (HC bug?) "
927 				"status = 0x%x\n", val);
928 	}
929 
930 	/* Send the halt and disable interrupts command */
931 	val = readl(op_reg_base + XHCI_CMD_OFFSET);
932 	val &= ~(XHCI_CMD_RUN | XHCI_IRQS);
933 	writel(val, op_reg_base + XHCI_CMD_OFFSET);
934 
935 	/* Wait for the HC to halt - poll every 125 usec (one microframe). */
936 	timeout = handshake(op_reg_base + XHCI_STS_OFFSET, XHCI_STS_HALT, 1,
937 			XHCI_MAX_HALT_USEC, 125);
938 	if (timeout) {
939 		val = readl(op_reg_base + XHCI_STS_OFFSET);
940 		dev_warn(&pdev->dev,
941 				"xHCI HW did not halt within %d usec "
942 				"status = 0x%x\n", XHCI_MAX_HALT_USEC, val);
943 	}
944 
945 	iounmap(base);
946 }
947 
948 static void quirk_usb_early_handoff(struct pci_dev *pdev)
949 {
950 	/* Skip Netlogic mips SoC's internal PCI USB controller.
951 	 * This device does not need/support EHCI/OHCI handoff
952 	 */
953 	if (pdev->vendor == 0x184e)	/* vendor Netlogic */
954 		return;
955 	if (pdev->class != PCI_CLASS_SERIAL_USB_UHCI &&
956 			pdev->class != PCI_CLASS_SERIAL_USB_OHCI &&
957 			pdev->class != PCI_CLASS_SERIAL_USB_EHCI &&
958 			pdev->class != PCI_CLASS_SERIAL_USB_XHCI)
959 		return;
960 
961 	if (pci_enable_device(pdev) < 0) {
962 		dev_warn(&pdev->dev, "Can't enable PCI device, "
963 				"BIOS handoff failed.\n");
964 		return;
965 	}
966 	if (pdev->class == PCI_CLASS_SERIAL_USB_UHCI)
967 		quirk_usb_handoff_uhci(pdev);
968 	else if (pdev->class == PCI_CLASS_SERIAL_USB_OHCI)
969 		quirk_usb_handoff_ohci(pdev);
970 	else if (pdev->class == PCI_CLASS_SERIAL_USB_EHCI)
971 		quirk_usb_disable_ehci(pdev);
972 	else if (pdev->class == PCI_CLASS_SERIAL_USB_XHCI)
973 		quirk_usb_handoff_xhci(pdev);
974 	pci_disable_device(pdev);
975 }
976 DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_ANY_ID, PCI_ANY_ID,
977 			PCI_CLASS_SERIAL_USB, 8, quirk_usb_early_handoff);
978