/*
 * 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;
        int cnt;

        if (!mmio_resource_enabled(pdev, 0))
                return;

        base = pci_ioremap_bar(pdev, 0);
        if (base == NULL)
                return;

        control = readl(base + OHCI_CONTROL);

/* On PA-RISC, PDC can leave IR set incorrectly; ignore it there. */
#ifdef __hppa__
#define OHCI_CTRL_MASK          (OHCI_CTRL_RWC | OHCI_CTRL_IR)
#else
#define OHCI_CTRL_MASK          OHCI_CTRL_RWC

        if (control & OHCI_CTRL_IR) {
                int wait_time = 500; /* arbitrary; 5 seconds */
                writel(OHCI_INTR_OC, base + OHCI_INTRENABLE);
                writel(OHCI_OCR, base + OHCI_CMDSTATUS);
                while (wait_time > 0 &&
                                readl(base + OHCI_CONTROL) & OHCI_CTRL_IR) {
                        wait_time -= 10;
                        msleep(10);
                }
                if (wait_time <= 0)
                        dev_warn(&pdev->dev, "OHCI: BIOS handoff failed"
                                        " (BIOS bug?) %08x\n",
                                        readl(base + OHCI_CONTROL));
        }
#endif

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

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

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

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

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

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

static const struct dmi_system_id 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-"),
                },
        },
        { }
};

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. */
        if (pdev->vendor == 0x8086 && pdev->device == 0x283a) {
                if (dmi_check_system(ehci_dmi_nohandoff_table))
                        try_handoff = 0;
        }

        if (try_handoff && (cap & EHCI_USBLEGSUP_BIOS)) {
                dev_dbg(&pdev->dev, "EHCI: BIOS handoff\n");

#if 0
/* aleksey_gorelov@phoenix.com reports that some systems need SMI forced on,
 * but that seems dubious in general (the BIOS left it off intentionally)
 * and is known to prevent some systems from booting.  so we won't do this
 * unless maybe we can determine when we're on a system that needs SMI forced.
 */
                /* BIOS workaround (?): be sure the pre-Linux code
                 * receives the SMI
                 */
                pci_read_config_dword(pdev, offset + EHCI_USBLEGCTLSTS, &val);
                pci_write_config_dword(pdev, offset + EHCI_USBLEGCTLSTS,
                                       val | EHCI_USBLEGCTLSTS_SOOE);
#endif

                /* some systems get upset if this semaphore is
                 * set for any other reason than forcing a BIOS
                 * handoff..
                 */
                pci_write_config_byte(pdev, offset + 3, 1);
        }

        /* if boot firmware now owns EHCI, spin till it hands it over. */
        if (try_handoff) {
                int msec = 1000;
                while ((cap & EHCI_USBLEGSUP_BIOS) && (msec > 0)) {
                        tried_handoff = 1;
                        msleep(10);
                        msec -= 10;
                        pci_read_config_dword(pdev, offset, &cap);
                }
        }

        if (cap & EHCI_USBLEGSUP_BIOS) {
                /* well, possibly buggy BIOS... try to shut it down,
                 * and hope nothing goes too wrong
                 */
                if (try_handoff)
                        dev_warn(&pdev->dev, "EHCI: BIOS handoff failed"
                                 " (BIOS bug?) %08x\n", cap);
                pci_write_config_byte(pdev, offset + 2, 0);
        }

        /* just in case, always disable EHCI SMIs */
        pci_write_config_dword(pdev, offset + EHCI_USBLEGCTLSTS, 0);

        /* If the BIOS ever owned the controller then we can't expect
         * any power sessions to remain intact.
         */
        if (tried_handoff)
                writel(0, op_reg_base + EHCI_CONFIGFLAG);
}

static void 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);