// SPDX-License-Identifier: GPL-2.0+
/*
 * (C) Copyright David Brownell 2000-2002
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/usb.h>
#include <linux/usb/hcd.h>

#include <asm/io.h>
#include <asm/irq.h>

#ifdef CONFIG_PPC_PMAC
#include <asm/machdep.h>
#include <asm/pmac_feature.h>
#include <asm/prom.h>
#endif

#include "usb.h"


/* PCI-based HCs are common, but plenty of non-PCI HCs are used too */

/*
 * Coordinate handoffs between EHCI and companion controllers
 * during EHCI probing and system resume.
 */

static DECLARE_RWSEM(companions_rwsem);

#define CL_UHCI         PCI_CLASS_SERIAL_USB_UHCI
#define CL_OHCI         PCI_CLASS_SERIAL_USB_OHCI
#define CL_EHCI         PCI_CLASS_SERIAL_USB_EHCI

static inline int is_ohci_or_uhci(struct pci_dev *pdev)
{
        return pdev->class == CL_OHCI || pdev->class == CL_UHCI;
}

typedef void (*companion_fn)(struct pci_dev *pdev, struct usb_hcd *hcd,
                struct pci_dev *companion, struct usb_hcd *companion_hcd);

/* Iterate over PCI devices in the same slot as pdev and call fn for each */
static void for_each_companion(struct pci_dev *pdev, struct usb_hcd *hcd,
                companion_fn fn)
{
        struct pci_dev          *companion;
        struct usb_hcd          *companion_hcd;
        unsigned int            slot = PCI_SLOT(pdev->devfn);

        /*
         * Iterate through other PCI functions in the same slot.
         * If the function's drvdata isn't set then it isn't bound to
         * a USB host controller driver, so skip it.
         */
        companion = NULL;
        for_each_pci_dev(companion) {
                if (companion->bus != pdev->bus ||
                                PCI_SLOT(companion->devfn) != slot)
                        continue;

                /*
                 * Companion device should be either UHCI,OHCI or EHCI host
                 * controller, otherwise skip.
                 */
                if (companion->class != CL_UHCI && companion->class != CL_OHCI &&
                                companion->class != CL_EHCI)
                        continue;

                companion_hcd = pci_get_drvdata(companion);
                if (!companion_hcd || !companion_hcd->self.root_hub)
                        continue;
                fn(pdev, hcd, companion, companion_hcd);
        }
}

/*
 * We're about to add an EHCI controller, which will unceremoniously grab
 * all the port connections away from its companions.  To prevent annoying
 * error messages, lock the companion's root hub and gracefully unconfigure
 * it beforehand.  Leave it locked until the EHCI controller is all set.
 */
static void ehci_pre_add(struct pci_dev *pdev, struct usb_hcd *hcd,
                struct pci_dev *companion, struct usb_hcd *companion_hcd)
{
        struct usb_device *udev;

        if (is_ohci_or_uhci(companion)) {
                udev = companion_hcd->self.root_hub;
                usb_lock_device(udev);
                usb_set_configuration(udev, 0);
        }
}

/*
 * Adding the EHCI controller has either succeeded or failed.  Set the
 * companion pointer accordingly, and in either case, reconfigure and
 * unlock the root hub.
 */
static void ehci_post_add(struct pci_dev *pdev, struct usb_hcd *hcd,
                struct pci_dev *companion, struct usb_hcd *companion_hcd)
{
        struct usb_device *udev;

        if (is_ohci_or_uhci(companion)) {
                if (dev_get_drvdata(&pdev->dev)) {      /* Succeeded */
                        dev_dbg(&pdev->dev, "HS companion for %s\n",
                                        dev_name(&companion->dev));
                        companion_hcd->self.hs_companion = &hcd->self;
                }
                udev = companion_hcd->self.root_hub;
                usb_set_configuration(udev, 1);
                usb_unlock_device(udev);
        }
}

/*
 * We just added a non-EHCI controller.  Find the EHCI controller to
 * which it is a companion, and store a pointer to the bus structure.
 */
static void non_ehci_add(struct pci_dev *pdev, struct usb_hcd *hcd,
                struct pci_dev *companion, struct usb_hcd *companion_hcd)
{
        if (is_ohci_or_uhci(pdev) && companion->class == CL_EHCI) {
                dev_dbg(&pdev->dev, "FS/LS companion for %s\n",
                                dev_name(&companion->dev));
                hcd->self.hs_companion = &companion_hcd->self;
        }
}

/* We are removing an EHCI controller.  Clear the companions' pointers. */
static void ehci_remove(struct pci_dev *pdev, struct usb_hcd *hcd,
                struct pci_dev *companion, struct usb_hcd *companion_hcd)
{
        if (is_ohci_or_uhci(companion))
                companion_hcd->self.hs_companion = NULL;
}

#ifdef  CONFIG_PM

/* An EHCI controller must wait for its companions before resuming. */
static void ehci_wait_for_companions(struct pci_dev *pdev, struct usb_hcd *hcd,
                struct pci_dev *companion, struct usb_hcd *companion_hcd)
{
        if (is_ohci_or_uhci(companion))
                device_pm_wait_for_dev(&pdev->dev, &companion->dev);
}

#endif  /* CONFIG_PM */

/*-------------------------------------------------------------------------*/

/* configure so an HC device and id are always provided */
/* always called with process context; sleeping is OK */

/**
 * usb_hcd_pci_probe - initialize PCI-based HCDs
 * @dev: USB Host Controller being probed
 * @id: pci hotplug id connecting controller to HCD framework
 * Context: !in_interrupt()
 *
 * Allocates basic PCI resources for this USB host controller, and
 * then invokes the start() method for the HCD associated with it
 * through the hotplug entry's driver_data.
 *
 * Store this function in the HCD's struct pci_driver as probe().
 *
 * Return: 0 if successful.
 */
int usb_hcd_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
{
        struct hc_driver        *driver;
        struct usb_hcd          *hcd;
        int                     retval;
        int                     hcd_irq = 0;

        if (usb_disabled())
                return -ENODEV;

        if (!id)
                return -EINVAL;
        driver = (struct hc_driver *)id->driver_data;
        if (!driver)
                return -EINVAL;

        if (pci_enable_device(dev) < 0)
                return -ENODEV;

        /*
         * The xHCI driver has its own irq management
         * make sure irq setup is not touched for xhci in generic hcd code
         */
        if ((driver->flags & HCD_MASK) < HCD_USB3) {
                if (!dev->irq) {
                        dev_err(&dev->dev,
                        "Found HC with no IRQ. Check BIOS/PCI %s setup!\n",
                                pci_name(dev));
                        retval = -ENODEV;
                        goto disable_pci;
                }
                hcd_irq = dev->irq;
        }

        hcd = usb_create_hcd(driver, &dev->dev, pci_name(dev));
        if (!hcd) {
                retval = -ENOMEM;
                goto disable_pci;
        }

        hcd->amd_resume_bug = (usb_hcd_amd_remote_wakeup_quirk(dev) &&
                        driver->flags & (HCD_USB11 | HCD_USB3)) ? 1 : 0;

        if (driver->flags & HCD_MEMORY) {
                /* EHCI, OHCI */
                hcd->rsrc_start = pci_resource_start(dev, 0);
                hcd->rsrc_len = pci_resource_len(dev, 0);
                if (!devm_request_mem_region(&dev->dev, hcd->rsrc_start,
                                hcd->rsrc_len, driver->description)) {
                        dev_dbg(&dev->dev, "controller already in use\n");
                        retval = -EBUSY;
                        goto put_hcd;
                }
                hcd->regs = devm_ioremap_nocache(&dev->dev, hcd->rsrc_start,
                                hcd->rsrc_len);
                if (hcd->regs == NULL) {
                        dev_dbg(&dev->dev, "error mapping memory\n");
                        retval = -EFAULT;
                        goto put_hcd;
                }

        } else {
                /* UHCI */
                int     region;

                for (region = 0; region < PCI_ROM_RESOURCE; region++) {
                        if (!(pci_resource_flags(dev, region) &
                                        IORESOURCE_IO))
                                continue;

                        hcd->rsrc_start = pci_resource_start(dev, region);
                        hcd->rsrc_len = pci_resource_len(dev, region);
                        if (devm_request_region(&dev->dev, hcd->rsrc_start,
                                        hcd->rsrc_len, driver->description))
                                break;
                }
                if (region == PCI_ROM_RESOURCE) {
                        dev_dbg(&dev->dev, "no i/o regions available\n");
                        retval = -EBUSY;
                        goto put_hcd;
                }
        }

        pci_set_master(dev);

        /* Note: dev_set_drvdata must be called while holding the rwsem */
        if (dev->class == CL_EHCI) {
                down_write(&companions_rwsem);
                dev_set_drvdata(&dev->dev, hcd);
                for_each_companion(dev, hcd, ehci_pre_add);
                retval = usb_add_hcd(hcd, hcd_irq, IRQF_SHARED);
                if (retval != 0)
                        dev_set_drvdata(&dev->dev, NULL);
                for_each_companion(dev, hcd, ehci_post_add);
                up_write(&companions_rwsem);
        } else {
                down_read(&companions_rwsem);
                dev_set_drvdata(&dev->dev, hcd);
                retval = usb_add_hcd(hcd, hcd_irq, IRQF_SHARED);
                if (retval != 0)
                        dev_set_drvdata(&dev->dev, NULL);
                else
                        for_each_companion(dev, hcd, non_ehci_add);
                up_read(&companions_rwsem);
        }

        if (retval != 0)
                goto put_hcd;
        device_wakeup_enable(hcd->self.controller);

        if (pci_dev_run_wake(dev))
                pm_runtime_put_noidle(&dev->dev);
        return retval;

put_hcd:
        usb_put_hcd(hcd);
disable_pci:
        pci_disable_device(dev);
        dev_err(&dev->dev, "init %s fail, %d\n", pci_name(dev), retval);
        return retval;
}
EXPORT_SYMBOL_GPL(usb_hcd_pci_probe);


/* may be called without controller electrically present */
/* may be called with controller, bus, and devices active */

/**
 * usb_hcd_pci_remove - shutdown processing for PCI-based HCDs
 * @dev: USB Host Controller being removed
 * Context: !in_interrupt()
 *
 * Reverses the effect of usb_hcd_pci_probe(), first invoking
 * the HCD's stop() method.  It is always called from a thread
 * context, normally "rmmod", "apmd", or something similar.
 *
 * Store this function in the HCD's struct pci_driver as remove().
 */
void usb_hcd_pci_remove(struct pci_dev *dev)
{
        struct usb_hcd          *hcd;

        hcd = pci_get_drvdata(dev);
        if (!hcd)
                return;

        if (pci_dev_run_wake(dev))
                pm_runtime_get_noresume(&dev->dev);

        /* Fake an interrupt request in order to give the driver a chance
         * to test whether the controller hardware has been removed (e.g.,
         * cardbus physical eject).
         */
        local_irq_disable();
        usb_hcd_irq(0, hcd);
        local_irq_enable();

        /* Note: dev_set_drvdata must be called while holding the rwsem */
        if (dev->class == CL_EHCI) {
                down_write(&companions_rwsem);
                for_each_companion(dev, hcd, ehci_remove);
                usb_remove_hcd(hcd);
                dev_set_drvdata(&dev->dev, NULL);
                up_write(&companions_rwsem);
        } else {
                /* Not EHCI; just clear the companion pointer */
                down_read(&companions_rwsem);
                hcd->self.hs_companion = NULL;
                usb_remove_hcd(hcd);
                dev_set_drvdata(&dev->dev, NULL);
                up_read(&companions_rwsem);
        }
        usb_put_hcd(hcd);
        pci_disable_device(dev);
}
EXPORT_SYMBOL_GPL(usb_hcd_pci_remove);

/**
 * usb_hcd_pci_shutdown - shutdown host controller
 * @dev: USB Host Controller being shutdown
 */
void usb_hcd_pci_shutdown(struct pci_dev *dev)
{
        struct usb_hcd          *hcd;

        hcd = pci_get_drvdata(dev);
        if (!hcd)
                return;

        if (test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags) &&
                        hcd->driver->shutdown) {
                hcd->driver->shutdown(hcd);
                if (usb_hcd_is_primary_hcd(hcd) && hcd->irq > 0)
                        free_irq(hcd->irq, hcd);
                pci_disable_device(dev);
        }
}
EXPORT_SYMBOL_GPL(usb_hcd_pci_shutdown);

#ifdef  CONFIG_PM

#ifdef  CONFIG_PPC_PMAC
static void powermac_set_asic(struct pci_dev *pci_dev, int enable)
{
        /* Enanble or disable ASIC clocks for USB */
        if (machine_is(powermac)) {
                struct device_node      *of_node;

                of_node = pci_device_to_OF_node(pci_dev);
                if (of_node)
                        pmac_call_feature(PMAC_FTR_USB_ENABLE,
                                        of_node, 0, enable);
        }
}

#else

static inline void powermac_set_asic(struct pci_dev *pci_dev, int enable)
{}

#endif  /* CONFIG_PPC_PMAC */

static int check_root_hub_suspended(struct device *dev)
{
        struct usb_hcd          *hcd = dev_get_drvdata(dev);

        if (HCD_RH_RUNNING(hcd)) {
                dev_warn(dev, "Root hub is not suspended\n");
                return -EBUSY;
        }
        if (hcd->shared_hcd) {
                hcd = hcd->shared_hcd;
                if (HCD_RH_RUNNING(hcd)) {
                        dev_warn(dev, "Secondary root hub is not suspended\n");
                        return -EBUSY;
                }
        }
        return 0;
}

static int suspend_common(struct device *dev, bool do_wakeup)
{
        struct pci_dev          *pci_dev = to_pci_dev(dev);
        struct usb_hcd          *hcd = pci_get_drvdata(pci_dev);
        int                     retval;

        /* Root hub suspend should have stopped all downstream traffic,
         * and all bus master traffic.  And done so for both the interface
         * and the stub usb_device (which we check here).  But maybe it
         * didn't; writing sysfs power/state files ignores such rules...
         */
        retval = check_root_hub_suspended(dev);
        if (retval)
                return retval;

        if (hcd->driver->pci_suspend && !HCD_DEAD(hcd)) {
                /* Optimization: Don't suspend if a root-hub wakeup is
                 * pending and it would cause the HCD to wake up anyway.
                 */
                if (do_wakeup && HCD_WAKEUP_PENDING(hcd))
                        return -EBUSY;
                if (do_wakeup && hcd->shared_hcd &&
                                HCD_WAKEUP_PENDING(hcd->shared_hcd))
                        return -EBUSY;
                retval = hcd->driver->pci_suspend(hcd, do_wakeup);
                suspend_report_result(hcd->driver->pci_suspend, retval);

                /* Check again in case wakeup raced with pci_suspend */
                if ((retval == 0 && do_wakeup && HCD_WAKEUP_PENDING(hcd)) ||
                                (retval == 0 && do_wakeup && hcd->shared_hcd &&
                                 HCD_WAKEUP_PENDING(hcd->shared_hcd))) {
                        if (hcd->driver->pci_resume)
                                hcd->driver->pci_resume(hcd, false);
                        retval = -EBUSY;
                }
                if (retval)
                        return retval;
        }

        /* If MSI-X is enabled, the driver will have synchronized all vectors
         * in pci_suspend(). If MSI or legacy PCI is enabled, that will be
         * synchronized here.
         */
        if (!hcd->msix_enabled)
                synchronize_irq(pci_dev->irq);

        /* Downstream ports from this root hub should already be quiesced, so
         * there will be no DMA activity.  Now we can shut down the upstream
         * link (except maybe for PME# resume signaling).  We'll enter a
         * low power state during suspend_noirq, if the hardware allows.
         */
        pci_disable_device(pci_dev);
        return retval;
}

static int resume_common(struct device *dev, int event)
{
        struct pci_dev          *pci_dev = to_pci_dev(dev);
        struct usb_hcd          *hcd = pci_get_drvdata(pci_dev);
        int                     retval;

        if (HCD_RH_RUNNING(hcd) ||
                        (hcd->shared_hcd &&
                         HCD_RH_RUNNING(hcd->shared_hcd))) {
                dev_dbg(dev, "can't resume, not suspended!\n");
                return 0;
        }

        retval = pci_enable_device(pci_dev);
        if (retval < 0) {
                dev_err(dev, "can't re-enable after resume, %d!\n", retval);
                return retval;
        }

        pci_set_master(pci_dev);

        if (hcd->driver->pci_resume && !HCD_DEAD(hcd)) {

                /*
                 * Only EHCI controllers have to wait for their companions.
                 * No locking is needed because PCI controller drivers do not
                 * get unbound during system resume.
                 */
                if (pci_dev->class == CL_EHCI && event != PM_EVENT_AUTO_RESUME)
                        for_each_companion(pci_dev, hcd,
                                        ehci_wait_for_companions);

                retval = hcd->driver->pci_resume(hcd,
                                event == PM_EVENT_RESTORE);
                if (retval) {
                        dev_err(dev, "PCI post-resume error %d!\n", retval);
                        usb_hc_died(hcd);
                }
        }
        return retval;
}

#ifdef  CONFIG_PM_SLEEP

static int hcd_pci_suspend(struct device *dev)
{
        return suspend_common(dev, device_may_wakeup(dev));
}

static int hcd_pci_suspend_noirq(struct device *dev)
{
        struct pci_dev          *pci_dev = to_pci_dev(dev);
        struct usb_hcd          *hcd = pci_get_drvdata(pci_dev);
        int                     retval;

        retval = check_root_hub_suspended(dev);
        if (retval)
                return retval;

        pci_save_state(pci_dev);

        /* If the root hub is dead rather than suspended, disallow remote
         * wakeup.  usb_hc_died() should ensure that both hosts are marked as
         * dying, so we only need to check the primary roothub.
         */
        if (HCD_DEAD(hcd))
                device_set_wakeup_enable(dev, 0);
        dev_dbg(dev, "wakeup: %d\n", device_may_wakeup(dev));

        /* Possibly enable remote wakeup,
         * choose the appropriate low-power state, and go to that state.
         */
        retval = pci_prepare_to_sleep(pci_dev);
        if (retval == -EIO) {           /* Low-power not supported */
                dev_dbg(dev, "--> PCI D0 legacy\n");
                retval = 0;
        } else if (retval == 0) {
                dev_dbg(dev, "--> PCI %s\n",
                                pci_power_name(pci_dev->current_state));
        } else {
                suspend_report_result(pci_prepare_to_sleep, retval);
                return retval;
        }

        powermac_set_asic(pci_dev, 0);
        return retval;
}

static int hcd_pci_resume_noirq(struct device *dev)
{
        powermac_set_asic(to_pci_dev(dev), 1);
        return 0;
}

static int hcd_pci_resume(struct device *dev)
{
        return resume_common(dev, PM_EVENT_RESUME);
}

static int hcd_pci_restore(struct device *dev)
{
        return resume_common(dev, PM_EVENT_RESTORE);
}

#else

#define hcd_pci_suspend         NULL
#define hcd_pci_suspend_noirq   NULL
#define hcd_pci_resume_noirq    NULL
#define hcd_pci_resume          NULL
#define hcd_pci_restore         NULL

#endif  /* CONFIG_PM_SLEEP */

static int hcd_pci_runtime_suspend(struct device *dev)
{
        int     retval;

        retval = suspend_common(dev, true);
        if (retval == 0)
                powermac_set_asic(to_pci_dev(dev), 0);
        dev_dbg(dev, "hcd_pci_runtime_suspend: %d\n", retval);
        return retval;
}

static int hcd_pci_runtime_resume(struct device *dev)
{
        int     retval;

        powermac_set_asic(to_pci_dev(dev), 1);
        retval = resume_common(dev, PM_EVENT_AUTO_RESUME);
        dev_dbg(dev, "hcd_pci_runtime_resume: %d\n", retval);
        return retval;
}

const struct dev_pm_ops usb_hcd_pci_pm_ops = {
        .suspend        = hcd_pci_suspend,
        .suspend_noirq  = hcd_pci_suspend_noirq,
        .resume_noirq   = hcd_pci_resume_noirq,
        .resume         = hcd_pci_resume,
        .freeze         = check_root_hub_suspended,
        .freeze_noirq   = check_root_hub_suspended,
        .thaw_noirq     = NULL,
        .thaw           = NULL,
        .poweroff       = hcd_pci_suspend,
        .poweroff_noirq = hcd_pci_suspend_noirq,
        .restore_noirq  = hcd_pci_resume_noirq,
        .restore        = hcd_pci_restore,
        .runtime_suspend = hcd_pci_runtime_suspend,
        .runtime_resume = hcd_pci_runtime_resume,
};
EXPORT_SYMBOL_GPL(usb_hcd_pci_pm_ops);

#endif  /* CONFIG_PM */