text: /*
   * 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/kconfig.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_USB2PRM      0xD4
  #define USB_INTEL_USB3_PSSEN   0xD8
  #define USB_INTEL_USB3PRM      0xDC
  
  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 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 mmio_resource_enabled(struct pci_dev *pdev, int idx)
  {
  	return pci_resource_start(pdev, idx) && mmio_enabled(pdev);
  }
  
  static void quirk_usb_handoff_ohci(struct pci_dev *pdev)
  {
  	void __iomem *base;
  	u32 control;
  	u32 fminterval = 0;
  	bool no_fminterval = false;
  	int cnt;
  
  	if (!mmio_resource_enabled(pdev, 0))
  		return;
  
  	base = pci_ioremap_bar(pdev, 0);
  	if (base == NULL)
  		return;
  
  	/*
  	 * ULi M5237 OHCI controller locks the whole system when accessing
  	 * the OHCI_FMINTERVAL offset.
  	 */
  	if (pdev->vendor == PCI_VENDOR_ID_AL && pdev->device == 0x5237)
  		no_fminterval = true;
  
  	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 */
  	if (!no_fminterval)
  		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);
  	}
  
  	if (!no_fminterval)
  		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 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-"),
  		},
  	},
  	{
  		/*  Pegatron Lucid (Ordissimo) */
  		.matches = {
  			DMI_MATCH(DMI_BOARD_NAME, "Ordissimo"),
  			DMI_MATCH(DMI_BIOS_VERSION, "Lucid-"),
  		},
  	},
  	{
  		/* HASEE E200 */
  		.matches = {
  			DMI_MATCH(DMI_BOARD_VENDOR, "HASEE"),
  			DMI_MATCH(DMI_BOARD_NAME, "E210"),
  			DMI_MATCH(DMI_BIOS_VERSION, "6.00"),
  		},
  	},
  	{ }
  };
  
  static void 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.
  	 *
  	 * The HASEE E200 hangs when the semaphore is set (bugzilla #77021).
  	 */
  	if (pdev->vendor == 0x8086 && (pdev->device == 0x283a ||
  			pdev->device == 0x27cc)) {
  		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 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;
  }
  
  #define PCI_DEVICE_ID_INTEL_LYNX_POINT_XHCI	0x8C31
  #define PCI_DEVICE_ID_INTEL_LYNX_POINT_LP_XHCI	0x9C31
  
  bool usb_is_intel_ppt_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;
  }
  
  /* The Intel Lynx Point chipset also has switchable ports. */
  bool usb_is_intel_lpt_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_LYNX_POINT_XHCI ||
  		 pdev->device == PCI_DEVICE_ID_INTEL_LYNX_POINT_LP_XHCI);
  }
  
  bool usb_is_intel_switchable_xhci(struct pci_dev *pdev)
  {
  	return usb_is_intel_ppt_switchable_xhci(pdev) ||
  		usb_is_intel_lpt_switchable_xhci(pdev);
  }
  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;
  
  	/* Don't switchover the ports if the user hasn't compiled the xHCI
  	 * driver.  Otherwise they will see "dead" USB ports that don't power
  	 * the devices.
  	 */
  	if (!IS_ENABLED(CONFIG_USB_XHCI_HCD)) {
  		dev_warn(&xhci_pdev->dev,
  				"CONFIG_USB_XHCI_HCD is turned off, "
  				"defaulting to EHCI.\n");
  		dev_warn(&xhci_pdev->dev,
  				"USB 3.0 devices will work at USB 2.0 speeds.\n");
  		usb_disable_xhci_ports(xhci_pdev);
  		return;
  	}
  
  	/* Read USB3PRM, the USB 3.0 Port Routing Mask Register
  	 * Indicate the ports that can be changed from OS.
  	 */
  	pci_read_config_dword(xhci_pdev, USB_INTEL_USB3PRM,
  			&ports_available);
  
  	dev_dbg(&xhci_pdev->dev, "Configurable ports to enable SuperSpeed: 0x%x\n",
  			ports_available);
  
  	/* Write USB3_PSSEN, the USB 3.0 Port SuperSpeed Enable
  	 * Register, to turn on SuperSpeed terminations for the
  	 * switchable 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);
  
  	/* Read XUSB2PRM, xHCI USB 2.0 Port Routing Mask Register
  	 * Indicate the USB 2.0 ports to be controlled by the xHCI host.
  	 */
  
  	pci_read_config_dword(xhci_pdev, USB_INTEL_USB2PRM,
  			&ports_available);
  
  	dev_dbg(&xhci_pdev->dev, "Configurable USB 2.0 ports to hand over to xCHI: 0x%x\n",
  			ports_available);
  
  	/* 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);
  
  void usb_disable_xhci_ports(struct pci_dev *xhci_pdev)
  {
  	pci_write_config_dword(xhci_pdev, USB_INTEL_USB3_PSSEN, 0x0);
  	pci_write_config_dword(xhci_pdev, USB_INTEL_XUSB2PR, 0x0);
  }
  EXPORT_SYMBOL_GPL(usb_disable_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 quirk_usb_handoff_xhci(struct pci_dev *pdev)
  {
  	void __iomem *base;
  	int ext_cap_offset;
  	void __iomem *op_reg_base;
  	u32 val;
  	int timeout;
  	int len = pci_resource_len(pdev, 0);
  
  	if (!mmio_resource_enabled(pdev, 0))
  		return;
  
  	base = ioremap_nocache(pci_resource_start(pdev, 0), len);
  	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 + sizeof(val)) > len) {
  			/* We're reading garbage from the controller */
  			dev_warn(&pdev->dev,
  				 "xHCI controller failing to respond");
  			return;
  		}
  
  		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);
  
  hc_init:
  	if (usb_is_intel_switchable_xhci(pdev))
  		usb_enable_xhci_ports(pdev);
  
  	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 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);
  