/*
 * Open Host Controller Interface (OHCI) driver for USB.
 *
 * Maintainer: Alan Stern <stern@rowland.harvard.edu>
 *
 * (C) Copyright 1999 Roman Weissgaerber <weissg@vienna.at>
 * (C) Copyright 2000-2004 David Brownell <dbrownell@users.sourceforge.net>
 *
 * [ Initialisation is based on Linus'  ]
 * [ uhci code and gregs ohci fragments ]
 * [ (C) Copyright 1999 Linus Torvalds  ]
 * [ (C) Copyright 1999 Gregory P. Smith]
 *
 *
 * OHCI is the main "non-Intel/VIA" standard for USB 1.1 host controller
 * interfaces (though some non-x86 Intel chips use it).  It supports
 * smarter hardware than UHCI.  A download link for the spec available
 * through the http://www.usb.org website.
 *
 * This file is licenced under the GPL.
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/pci.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/ioport.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/timer.h>
#include <linux/list.h>
#include <linux/usb.h>
#include <linux/usb/otg.h>
#include <linux/usb/hcd.h>
#include <linux/dma-mapping.h>
#include <linux/dmapool.h>
#include <linux/workqueue.h>
#include <linux/debugfs.h>

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


#define DRIVER_AUTHOR "Roman Weissgaerber, David Brownell"
#define DRIVER_DESC "USB 1.1 'Open' Host Controller (OHCI) Driver"

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

#undef OHCI_VERBOSE_DEBUG       /* not always helpful */

/* For initializing controller (mask in an HCFS mode too) */
#define OHCI_CONTROL_INIT       OHCI_CTRL_CBSR
#define OHCI_INTR_INIT \
                (OHCI_INTR_MIE | OHCI_INTR_RHSC | OHCI_INTR_UE \
                | OHCI_INTR_RD | OHCI_INTR_WDH)

#ifdef __hppa__
/* On PA-RISC, PDC can leave IR set incorrectly; ignore it there. */
#define IR_DISABLE
#endif

#ifdef CONFIG_ARCH_OMAP
/* OMAP doesn't support IR (no SMM; not needed) */
#define IR_DISABLE
#endif

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

static const char       hcd_name [] = "ohci_hcd";

#define STATECHANGE_DELAY       msecs_to_jiffies(300)

#include "ohci.h"
#include "pci-quirks.h"

static void ohci_dump (struct ohci_hcd *ohci, int verbose);
static int ohci_init (struct ohci_hcd *ohci);
static void ohci_stop (struct usb_hcd *hcd);

#if defined(CONFIG_PM) || defined(CONFIG_PCI)
static int ohci_restart (struct ohci_hcd *ohci);
#endif

#ifdef CONFIG_PCI
static void sb800_prefetch(struct ohci_hcd *ohci, int on);
#else
static inline void sb800_prefetch(struct ohci_hcd *ohci, int on)
{
        return;
}
#endif


#include "ohci-hub.c"
#include "ohci-dbg.c"
#include "ohci-mem.c"
#include "ohci-q.c"


/*
 * On architectures with edge-triggered interrupts we must never return
 * IRQ_NONE.
 */
#if defined(CONFIG_SA1111)  /* ... or other edge-triggered systems */
#define IRQ_NOTMINE     IRQ_HANDLED
#else
#define IRQ_NOTMINE     IRQ_NONE
#endif


/* Some boards misreport power switching/overcurrent */
static bool distrust_firmware = 1;
module_param (distrust_firmware, bool, 0);
MODULE_PARM_DESC (distrust_firmware,
        "true to distrust firmware power/overcurrent setup");

/* Some boards leave IR set wrongly, since they fail BIOS/SMM handshakes */
static bool no_handshake = 0;
module_param (no_handshake, bool, 0);
MODULE_PARM_DESC (no_handshake, "true (not default) disables BIOS handshake");

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

/*
 * queue up an urb for anything except the root hub
 */
static int ohci_urb_enqueue (
        struct usb_hcd  *hcd,
        struct urb      *urb,
        gfp_t           mem_flags
) {
        struct ohci_hcd *ohci = hcd_to_ohci (hcd);
        struct ed       *ed;
        urb_priv_t      *urb_priv;
        unsigned int    pipe = urb->pipe;
        int             i, size = 0;
        unsigned long   flags;
        int             retval = 0;

#ifdef OHCI_VERBOSE_DEBUG
        urb_print(urb, "SUB", usb_pipein(pipe), -EINPROGRESS);
#endif

        /* every endpoint has a ed, locate and maybe (re)initialize it */
        if (! (ed = ed_get (ohci, urb->ep, urb->dev, pipe, urb->interval)))
                return -ENOMEM;

        /* for the private part of the URB we need the number of TDs (size) */
        switch (ed->type) {
                case PIPE_CONTROL:
                        /* td_submit_urb() doesn't yet handle these */
                        if (urb->transfer_buffer_length > 4096)
                                return -EMSGSIZE;

                        /* 1 TD for setup, 1 for ACK, plus ... */
                        size = 2;
                        /* FALLTHROUGH */
                // case PIPE_INTERRUPT:
                // case PIPE_BULK:
                default:
                        /* one TD for every 4096 Bytes (can be up to 8K) */
                        size += urb->transfer_buffer_length / 4096;
                        /* ... and for any remaining bytes ... */
                        if ((urb->transfer_buffer_length % 4096) != 0)
                                size++;
                        /* ... and maybe a zero length packet to wrap it up */
                        if (size == 0)
                                size++;
                        else if ((urb->transfer_flags & URB_ZERO_PACKET) != 0
                                && (urb->transfer_buffer_length
                                        % usb_maxpacket (urb->dev, pipe,
                                                usb_pipeout (pipe))) == 0)
                                size++;
                        break;
                case PIPE_ISOCHRONOUS: /* number of packets from URB */
                        size = urb->number_of_packets;
                        break;
        }

        /* allocate the private part of the URB */
        urb_priv = kzalloc (sizeof (urb_priv_t) + size * sizeof (struct td *),
                        mem_flags);
        if (!urb_priv)
                return -ENOMEM;
        INIT_LIST_HEAD (&urb_priv->pending);
        urb_priv->length = size;
        urb_priv->ed = ed;

        /* allocate the TDs (deferring hash chain updates) */
        for (i = 0; i < size; i++) {
                urb_priv->td [i] = td_alloc (ohci, mem_flags);
                if (!urb_priv->td [i]) {
                        urb_priv->length = i;
                        urb_free_priv (ohci, urb_priv);
                        return -ENOMEM;
                }
        }

        spin_lock_irqsave (&ohci->lock, flags);

        /* don't submit to a dead HC */
        if (!HCD_HW_ACCESSIBLE(hcd)) {
                retval = -ENODEV;
                goto fail;
        }
        if (ohci->rh_state != OHCI_RH_RUNNING) {
                retval = -ENODEV;
                goto fail;
        }
        retval = usb_hcd_link_urb_to_ep(hcd, urb);
        if (retval)
                goto fail;

        /* schedule the ed if needed */
        if (ed->state == ED_IDLE) {
                retval = ed_schedule (ohci, ed);
                if (retval < 0) {
                        usb_hcd_unlink_urb_from_ep(hcd, urb);
                        goto fail;
                }
                if (ed->type == PIPE_ISOCHRONOUS) {
                        u16     frame = ohci_frame_no(ohci);

                        /* delay a few frames before the first TD */
                        frame += max_t (u16, 8, ed->interval);
                        frame &= ~(ed->interval - 1);
                        frame |= ed->branch;
                        urb->start_frame = frame;

                        /* yes, only URB_ISO_ASAP is supported, and
                         * urb->start_frame is never used as input.
                         */
                }
        } else if (ed->type == PIPE_ISOCHRONOUS)
                urb->start_frame = ed->last_iso + ed->interval;

        /* fill the TDs and link them to the ed; and
         * enable that part of the schedule, if needed
         * and update count of queued periodic urbs
         */
        urb->hcpriv = urb_priv;
        td_submit_urb (ohci, urb);

fail:
        if (retval)
                urb_free_priv (ohci, urb_priv);
        spin_unlock_irqrestore (&ohci->lock, flags);
        return retval;
}

/*
 * decouple the URB from the HC queues (TDs, urb_priv).
 * reporting is always done
 * asynchronously, and we might be dealing with an urb that's
 * partially transferred, or an ED with other urbs being unlinked.
 */
static int ohci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
{
        struct ohci_hcd         *ohci = hcd_to_ohci (hcd);
        unsigned long           flags;
        int                     rc;

#ifdef OHCI_VERBOSE_DEBUG
        urb_print(urb, "UNLINK", 1, status);
#endif

        spin_lock_irqsave (&ohci->lock, flags);
        rc = usb_hcd_check_unlink_urb(hcd, urb, status);
        if (rc) {
                ;       /* Do nothing */
        } else if (ohci->rh_state == OHCI_RH_RUNNING) {
                urb_priv_t  *urb_priv;

                /* Unless an IRQ completed the unlink while it was being
                 * handed to us, flag it for unlink and giveback, and force
                 * some upcoming INTR_SF to call finish_unlinks()
                 */
                urb_priv = urb->hcpriv;
                if (urb_priv) {
                        if (urb_priv->ed->state == ED_OPER)
                                start_ed_unlink (ohci, urb_priv->ed);
                }
        } else {
                /*
                 * with HC dead, we won't respect hc queue pointers
                 * any more ... just clean up every urb's memory.
                 */
                if (urb->hcpriv)
                        finish_urb(ohci, urb, status);
        }
        spin_unlock_irqrestore (&ohci->lock, flags);
        return rc;
}

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

/* frees config/altsetting state for endpoints,
 * including ED memory, dummy TD, and bulk/intr data toggle
 */

static void
ohci_endpoint_disable (struct usb_hcd *hcd, struct usb_host_endpoint *ep)
{
        struct ohci_hcd         *ohci = hcd_to_ohci (hcd);
        unsigned long           flags;
        struct ed               *ed = ep->hcpriv;
        unsigned                limit = 1000;

        /* ASSERT:  any requests/urbs are being unlinked */
        /* ASSERT:  nobody can be submitting urbs for this any more */

        if (!ed)
                return;

rescan:
        spin_lock_irqsave (&ohci->lock, flags);

        if (ohci->rh_state != OHCI_RH_RUNNING) {
sanitize:
                ed->state = ED_IDLE;
                if (quirk_zfmicro(ohci) && ed->type == PIPE_INTERRUPT)
                        ohci->eds_scheduled--;
                finish_unlinks (ohci, 0);
        }

        switch (ed->state) {
        case ED_UNLINK:         /* wait for hw to finish? */
                /* major IRQ delivery trouble loses INTR_SF too... */
                if (limit-- == 0) {
                        ohci_warn(ohci, "ED unlink timeout\n");
                        if (quirk_zfmicro(ohci)) {
                                ohci_warn(ohci, "Attempting ZF TD recovery\n");
                                ohci->ed_to_check = ed;
                                ohci->zf_delay = 2;
                        }
                        goto sanitize;
                }
                spin_unlock_irqrestore (&ohci->lock, flags);
                schedule_timeout_uninterruptible(1);
                goto rescan;
        case ED_IDLE:           /* fully unlinked */
                if (list_empty (&ed->td_list)) {
                        td_free (ohci, ed->dummy);
                        ed_free (ohci, ed);
                        break;
                }
                /* else FALL THROUGH */
        default:
                /* caller was supposed to have unlinked any requests;
                 * that's not our job.  can't recover; must leak ed.
                 */
                ohci_err (ohci, "leak ed %p (#%02x) state %d%s\n",
                        ed, ep->desc.bEndpointAddress, ed->state,
                        list_empty (&ed->td_list) ? "" : " (has tds)");
                td_free (ohci, ed->dummy);
                break;
        }
        ep->hcpriv = NULL;
        spin_unlock_irqrestore (&ohci->lock, flags);
}

static int ohci_get_frame (struct usb_hcd *hcd)
{
        struct ohci_hcd         *ohci = hcd_to_ohci (hcd);

        return ohci_frame_no(ohci);
}

static void ohci_usb_reset (struct ohci_hcd *ohci)
{
        ohci->hc_control = ohci_readl (ohci, &ohci->regs->control);
        ohci->hc_control &= OHCI_CTRL_RWC;
        ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
        ohci->rh_state = OHCI_RH_HALTED;
}

/* ohci_shutdown forcibly disables IRQs and DMA, helping kexec and
 * other cases where the next software may expect clean state from the
 * "firmware".  this is bus-neutral, unlike shutdown() methods.
 */
static void
ohci_shutdown (struct usb_hcd *hcd)
{
        struct ohci_hcd *ohci;

        ohci = hcd_to_ohci (hcd);
        ohci_writel(ohci, (u32) ~0, &ohci->regs->intrdisable);

        /* Software reset, after which the controller goes into SUSPEND */
        ohci_writel(ohci, OHCI_HCR, &ohci->regs->cmdstatus);
        ohci_readl(ohci, &ohci->regs->cmdstatus);       /* flush the writes */
        udelay(10);

        ohci_writel(ohci, ohci->fminterval, &ohci->regs->fminterval);
}

static int check_ed(struct ohci_hcd *ohci, struct ed *ed)
{
        return (hc32_to_cpu(ohci, ed->hwINFO) & ED_IN) != 0
                && (hc32_to_cpu(ohci, ed->hwHeadP) & TD_MASK)
                        == (hc32_to_cpu(ohci, ed->hwTailP) & TD_MASK)
                && !list_empty(&ed->td_list);
}

/* ZF Micro watchdog timer callback. The ZF Micro chipset sometimes completes
 * an interrupt TD but neglects to add it to the donelist.  On systems with
 * this chipset, we need to periodically check the state of the queues to look
 * for such "lost" TDs.
 */
static void unlink_watchdog_func(unsigned long _ohci)
{
        unsigned long   flags;
        unsigned        max;
        unsigned        seen_count = 0;
        unsigned        i;
        struct ed       **seen = NULL;
        struct ohci_hcd *ohci = (struct ohci_hcd *) _ohci;

        spin_lock_irqsave(&ohci->lock, flags);
        max = ohci->eds_scheduled;
        if (!max)
                goto done;

        if (ohci->ed_to_check)
                goto out;

        seen = kcalloc(max, sizeof *seen, GFP_ATOMIC);
        if (!seen)
                goto out;

        for (i = 0; i < NUM_INTS; i++) {
                struct ed       *ed = ohci->periodic[i];

                while (ed) {
                        unsigned        temp;

                        /* scan this branch of the periodic schedule tree */
                        for (temp = 0; temp < seen_count; temp++) {
                                if (seen[temp] == ed) {
                                        /* we've checked it and what's after */
                                        ed = NULL;
                                        break;
                                }
                        }
                        if (!ed)
                                break;
                        seen[seen_count++] = ed;
                        if (!check_ed(ohci, ed)) {
                                ed = ed->ed_next;
                                continue;
                        }

                        /* HC's TD list is empty, but HCD sees at least one
                         * TD that's not been sent through the donelist.
                         */
                        ohci->ed_to_check = ed;
                        ohci->zf_delay = 2;

                        /* The HC may wait until the next frame to report the
                         * TD as done through the donelist and INTR_WDH.  (We
                         * just *assume* it's not a multi-TD interrupt URB;
                         * those could defer the IRQ more than one frame, using
                         * DI...)  Check again after the next INTR_SF.
                         */
                        ohci_writel(ohci, OHCI_INTR_SF,
                                        &ohci->regs->intrstatus);
                        ohci_writel(ohci, OHCI_INTR_SF,
                                        &ohci->regs->intrenable);

                        /* flush those writes */
                        (void) ohci_readl(ohci, &ohci->regs->control);

                        goto out;
                }
        }
out:
        kfree(seen);
        if (ohci->eds_scheduled)
                mod_timer(&ohci->unlink_watchdog, round_jiffies(jiffies + HZ));
done:
        spin_unlock_irqrestore(&ohci->lock, flags);
}

/*-------------------------------------------------------------------------*
 * HC functions
 *-------------------------------------------------------------------------*/

/* init memory, and kick BIOS/SMM off */

static int ohci_init (struct ohci_hcd *ohci)
{
        int ret;
        struct usb_hcd *hcd = ohci_to_hcd(ohci);

        if (distrust_firmware)
                ohci->flags |= OHCI_QUIRK_HUB_POWER;

        ohci->rh_state = OHCI_RH_HALTED;
        ohci->regs = hcd->regs;

        /* REVISIT this BIOS handshake is now moved into PCI "quirks", and
         * was never needed for most non-PCI systems ... remove the code?
         */

#ifndef IR_DISABLE
        /* SMM owns the HC?  not for long! */
        if (!no_handshake && ohci_readl (ohci,
                                        &ohci->regs->control) & OHCI_CTRL_IR) {
                u32 temp;

                ohci_dbg (ohci, "USB HC TakeOver from BIOS/SMM\n");

                /* this timeout is arbitrary.  we make it long, so systems
                 * depending on usb keyboards may be usable even if the
                 * BIOS/SMM code seems pretty broken.
                 */
                temp = 500;     /* arbitrary: five seconds */

                ohci_writel (ohci, OHCI_INTR_OC, &ohci->regs->intrenable);
                ohci_writel (ohci, OHCI_OCR, &ohci->regs->cmdstatus);
                while (ohci_readl (ohci, &ohci->regs->control) & OHCI_CTRL_IR) {
                        msleep (10);
                        if (--temp == 0) {
                                ohci_err (ohci, "USB HC takeover failed!"
                                        "  (BIOS/SMM bug)\n");
                                return -EBUSY;
                        }
                }
                ohci_usb_reset (ohci);
        }
#endif

        /* Disable HC interrupts */
        ohci_writel (ohci, OHCI_INTR_MIE, &ohci->regs->intrdisable);

        /* flush the writes, and save key bits like RWC */
        if (ohci_readl (ohci, &ohci->regs->control) & OHCI_CTRL_RWC)
                ohci->hc_control |= OHCI_CTRL_RWC;

        /* Read the number of ports unless overridden */
        if (ohci->num_ports == 0)
                ohci->num_ports = roothub_a(ohci) & RH_A_NDP;

        if (ohci->hcca)
                return 0;

        ohci->hcca = dma_alloc_coherent (hcd->self.controller,
                        sizeof *ohci->hcca, &ohci->hcca_dma, 0);
        if (!ohci->hcca)
                return -ENOMEM;

        if ((ret = ohci_mem_init (ohci)) < 0)
                ohci_stop (hcd);
        else {
                create_debug_files (ohci);
        }

        return ret;
}

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

/* Start an OHCI controller, set the BUS operational
 * resets USB and controller
 * enable interrupts
 */
static int ohci_run (struct ohci_hcd *ohci)
{
        u32                     mask, val;
        int                     first = ohci->fminterval == 0;
        struct usb_hcd          *hcd = ohci_to_hcd(ohci);

        ohci->rh_state = OHCI_RH_HALTED;

        /* boot firmware should have set this up (5.1.1.3.1) */
        if (first) {

                val = ohci_readl (ohci, &ohci->regs->fminterval);
                ohci->fminterval = val & 0x3fff;
                if (ohci->fminterval != FI)
                        ohci_dbg (ohci, "fminterval delta %d\n",
                                ohci->fminterval - FI);
                ohci->fminterval |= FSMP (ohci->fminterval) << 16;
                /* also: power/overcurrent flags in roothub.a */
        }

        /* Reset USB nearly "by the book".  RemoteWakeupConnected has
         * to be checked in case boot firmware (BIOS/SMM/...) has set up
         * wakeup in a way the bus isn't aware of (e.g., legacy PCI PM).
         * If the bus glue detected wakeup capability then it should
         * already be enabled; if so we'll just enable it again.
         */
        if ((ohci->hc_control & OHCI_CTRL_RWC) != 0)
                device_set_wakeup_capable(hcd->self.controller, 1);

        switch (ohci->hc_control & OHCI_CTRL_HCFS) {
        case OHCI_USB_OPER:
                val = 0;
                break;
        case OHCI_USB_SUSPEND:
        case OHCI_USB_RESUME:
                ohci->hc_control &= OHCI_CTRL_RWC;
                ohci->hc_control |= OHCI_USB_RESUME;
                val = 10 /* msec wait */;
                break;
        // case OHCI_USB_RESET:
        default:
                ohci->hc_control &= OHCI_CTRL_RWC;
                ohci->hc_control |= OHCI_USB_RESET;
                val = 50 /* msec wait */;
                break;
        }
        ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
        // flush the writes
        (void) ohci_readl (ohci, &ohci->regs->control);
        msleep(val);

        memset (ohci->hcca, 0, sizeof (struct ohci_hcca));

        /* 2msec timelimit here means no irqs/preempt */
        spin_lock_irq (&ohci->lock);

retry:
        /* HC Reset requires max 10 us delay */
        ohci_writel (ohci, OHCI_HCR,  &ohci->regs->cmdstatus);
        val = 30;       /* ... allow extra time */
        while ((ohci_readl (ohci, &ohci->regs->cmdstatus) & OHCI_HCR) != 0) {
                if (--val == 0) {
                        spin_unlock_irq (&ohci->lock);
                        ohci_err (ohci, "USB HC reset timed out!\n");
                        return -1;
                }
                udelay (1);
        }

        /* now we're in the SUSPEND state ... must go OPERATIONAL
         * within 2msec else HC enters RESUME
         *
         * ... but some hardware won't init fmInterval "by the book"
         * (SiS, OPTi ...), so reset again instead.  SiS doesn't need
         * this if we write fmInterval after we're OPERATIONAL.
         * Unclear about ALi, ServerWorks, and others ... this could
         * easily be a longstanding bug in chip init on Linux.
         */
        if (ohci->flags & OHCI_QUIRK_INITRESET) {
                ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
                // flush those writes
                (void) ohci_readl (ohci, &ohci->regs->control);
        }

        /* Tell the controller where the control and bulk lists are
         * The lists are empty now. */
        ohci_writel (ohci, 0, &ohci->regs->ed_controlhead);
        ohci_writel (ohci, 0, &ohci->regs->ed_bulkhead);

        /* a reset clears this */
        ohci_writel (ohci, (u32) ohci->hcca_dma, &ohci->regs->hcca);

        periodic_reinit (ohci);

        /* some OHCI implementations are finicky about how they init.
         * bogus values here mean not even enumeration could work.
         */
        if ((ohci_readl (ohci, &ohci->regs->fminterval) & 0x3fff0000) == 0
                        || !ohci_readl (ohci, &ohci->regs->periodicstart)) {
                if (!(ohci->flags & OHCI_QUIRK_INITRESET)) {
                        ohci->flags |= OHCI_QUIRK_INITRESET;
                        ohci_dbg (ohci, "enabling initreset quirk\n");
                        goto retry;
                }
                spin_unlock_irq (&ohci->lock);
                ohci_err (ohci, "init err (%08x %04x)\n",
                        ohci_readl (ohci, &ohci->regs->fminterval),
                        ohci_readl (ohci, &ohci->regs->periodicstart));
                return -EOVERFLOW;
        }

        /* use rhsc irqs after khubd is fully initialized */
        set_bit(HCD_FLAG_POLL_RH, &hcd->flags);
        hcd->uses_new_polling = 1;

        /* start controller operations */
        ohci->hc_control &= OHCI_CTRL_RWC;
        ohci->hc_control |= OHCI_CONTROL_INIT | OHCI_USB_OPER;
        ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
        ohci->rh_state = OHCI_RH_RUNNING;

        /* wake on ConnectStatusChange, matching external hubs */
        ohci_writel (ohci, RH_HS_DRWE, &ohci->regs->roothub.status);

        /* Choose the interrupts we care about now, others later on demand */
        mask = OHCI_INTR_INIT;
        ohci_writel (ohci, ~0, &ohci->regs->intrstatus);
        ohci_writel (ohci, mask, &ohci->regs->intrenable);

        /* handle root hub init quirks ... */
        val = roothub_a (ohci);
        val &= ~(RH_A_PSM | RH_A_OCPM);
        if (ohci->flags & OHCI_QUIRK_SUPERIO) {
                /* NSC 87560 and maybe others */
                val |= RH_A_NOCP;
                val &= ~(RH_A_POTPGT | RH_A_NPS);
                ohci_writel (ohci, val, &ohci->regs->roothub.a);
        } else if ((ohci->flags & OHCI_QUIRK_AMD756) ||
                        (ohci->flags & OHCI_QUIRK_HUB_POWER)) {
                /* hub power always on; required for AMD-756 and some
                 * Mac platforms.  ganged overcurrent reporting, if any.
                 */
                val |= RH_A_NPS;
                ohci_writel (ohci, val, &ohci->regs->roothub.a);
        }
        ohci_writel (ohci, RH_HS_LPSC, &ohci->regs->roothub.status);
        ohci_writel (ohci, (val & RH_A_NPS) ? 0 : RH_B_PPCM,
                                                &ohci->regs->roothub.b);
        // flush those writes
        (void) ohci_readl (ohci, &ohci->regs->control);

        ohci->next_statechange = jiffies + STATECHANGE_DELAY;
        spin_unlock_irq (&ohci->lock);

        // POTPGT delay is bits 24-31, in 2 ms units.
        mdelay ((val >> 23) & 0x1fe);

        if (quirk_zfmicro(ohci)) {
                /* Create timer to watch for bad queue state on ZF Micro */
                setup_timer(&ohci->unlink_watchdog, unlink_watchdog_func,
                                (unsigned long) ohci);

                ohci->eds_scheduled = 0;
                ohci->ed_to_check = NULL;
        }

        ohci_dump (ohci, 1);

        return 0;
}

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

/* an interrupt happens */

static irqreturn_t ohci_irq (struct usb_hcd *hcd)
{
        struct ohci_hcd         *ohci = hcd_to_ohci (hcd);
        struct ohci_regs __iomem *regs = ohci->regs;
        int                     ints;

        /* Read interrupt status (and flush pending writes).  We ignore the
         * optimization of checking the LSB of hcca->done_head; it doesn't
         * work on all systems (edge triggering for OHCI can be a factor).
         */
        ints = ohci_readl(ohci, &regs->intrstatus);

        /* Check for an all 1's result which is a typical consequence
         * of dead, unclocked, or unplugged (CardBus...) devices
         */
        if (ints == ~(u32)0) {
                ohci->rh_state = OHCI_RH_HALTED;
                ohci_dbg (ohci, "device removed!\n");
                usb_hc_died(hcd);
                return IRQ_HANDLED;
        }

        /* We only care about interrupts that are enabled */
        ints &= ohci_readl(ohci, &regs->intrenable);

        /* interrupt for some other device? */
        if (ints == 0 || unlikely(ohci->rh_state == OHCI_RH_HALTED))
                return IRQ_NOTMINE;

        if (ints & OHCI_INTR_UE) {
                // e.g. due to PCI Master/Target Abort
                if (quirk_nec(ohci)) {
                        /* Workaround for a silicon bug in some NEC chips used
                         * in Apple's PowerBooks. Adapted from Darwin code.
                         */
                        ohci_err (ohci, "OHCI Unrecoverable Error, scheduling NEC chip restart\n");

                        ohci_writel (ohci, OHCI_INTR_UE, &regs->intrdisable);

                        schedule_work (&ohci->nec_work);
                } else {
                        ohci_err (ohci, "OHCI Unrecoverable Error, disabled\n");
                        ohci->rh_state = OHCI_RH_HALTED;
                        usb_hc_died(hcd);
                }

                ohci_dump (ohci, 1);
                ohci_usb_reset (ohci);
        }

        if (ints & OHCI_INTR_RHSC) {
                ohci_vdbg(ohci, "rhsc\n");
                ohci->next_statechange = jiffies + STATECHANGE_DELAY;
                ohci_writel(ohci, OHCI_INTR_RD | OHCI_INTR_RHSC,
                                &regs->intrstatus);

                /* NOTE: Vendors didn't always make the same implementation
                 * choices for RHSC.  Many followed the spec; RHSC triggers
                 * on an edge, like setting and maybe clearing a port status
                 * change bit.  With others it's level-triggered, active
                 * until khubd clears all the port status change bits.  We'll
                 * always disable it here and rely on polling until khubd
                 * re-enables it.
                 */
                ohci_writel(ohci, OHCI_INTR_RHSC, &regs->intrdisable);
                usb_hcd_poll_rh_status(hcd);
        }

        /* For connect and disconnect events, we expect the controller
         * to turn on RHSC along with RD.  But for remote wakeup events
         * this might not happen.
         */
        else if (ints & OHCI_INTR_RD) {
                ohci_vdbg(ohci, "resume detect\n");
                ohci_writel(ohci, OHCI_INTR_RD, &regs->intrstatus);
                set_bit(HCD_FLAG_POLL_RH, &hcd->flags);
                if (ohci->autostop) {
                        spin_lock (&ohci->lock);
                        ohci_rh_resume (ohci);
                        spin_unlock (&ohci->lock);
                } else
                        usb_hcd_resume_root_hub(hcd);
        }

        if (ints & OHCI_INTR_WDH) {
                spin_lock (&ohci->lock);
                dl_done_list (ohci);
                spin_unlock (&ohci->lock);
        }

        if (quirk_zfmicro(ohci) && (ints & OHCI_INTR_SF)) {
                spin_lock(&ohci->lock);
                if (ohci->ed_to_check) {
                        struct ed *ed = ohci->ed_to_check;

                        if (check_ed(ohci, ed)) {
                                /* HC thinks the TD list is empty; HCD knows
                                 * at least one TD is outstanding
                                 */
                                if (--ohci->zf_delay == 0) {
                                        struct td *td = list_entry(
                                                ed->td_list.next,
                                                struct td, td_list);
                                        ohci_warn(ohci,
                                                  "Reclaiming orphan TD %p\n",
                                                  td);
                                        takeback_td(ohci, td);
                                        ohci->ed_to_check = NULL;
                                }
                        } else
                                ohci->ed_to_check = NULL;
                }
                spin_unlock(&ohci->lock);
        }

        /* could track INTR_SO to reduce available PCI/... bandwidth */

        /* handle any pending URB/ED unlinks, leaving INTR_SF enabled
         * when there's still unlinking to be done (next frame).
         */
        spin_lock (&ohci->lock);
        if (ohci->ed_rm_list)
                finish_unlinks (ohci, ohci_frame_no(ohci));
        if ((ints & OHCI_INTR_SF) != 0
                        && !ohci->ed_rm_list
                        && !ohci->ed_to_check
                        && ohci->rh_state == OHCI_RH_RUNNING)
                ohci_writel (ohci, OHCI_INTR_SF, &regs->intrdisable);
        spin_unlock (&ohci->lock);

        if (ohci->rh_state == OHCI_RH_RUNNING) {
                ohci_writel (ohci, ints, &regs->intrstatus);
                ohci_writel (ohci, OHCI_INTR_MIE, &regs->intrenable);
                // flush those writes
                (void) ohci_readl (ohci, &ohci->regs->control);
        }

        return IRQ_HANDLED;
}

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

static void ohci_stop (struct usb_hcd *hcd)
{
        struct ohci_hcd         *ohci = hcd_to_ohci (hcd);

        ohci_dump (ohci, 1);

        if (quirk_nec(ohci))
                flush_work_sync(&ohci->nec_work);

        ohci_usb_reset (ohci);
        ohci_writel (ohci, OHCI_INTR_MIE, &ohci->regs->intrdisable);
        free_irq(hcd->irq, hcd);
        hcd->irq = 0;

        if (quirk_zfmicro(ohci))
                del_timer(&ohci->unlink_watchdog);
        if (quirk_amdiso(ohci))
                usb_amd_dev_put();

        remove_debug_files (ohci);
        ohci_mem_cleanup (ohci);
        if (ohci->hcca) {
                dma_free_coherent (hcd->self.controller,
                                sizeof *ohci->hcca,
                                ohci->hcca, ohci->hcca_dma);
                ohci->hcca = NULL;
                ohci->hcca_dma = 0;
        }
}

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

#if defined(CONFIG_PM) || defined(CONFIG_PCI)

/* must not be called from interrupt context */
static int ohci_restart (struct ohci_hcd *ohci)
{
        int temp;
        int i;
        struct urb_priv *priv;

        spin_lock_irq(&ohci->lock);
        ohci->rh_state = OHCI_RH_HALTED;

        /* Recycle any "live" eds/tds (and urbs). */
        if (!list_empty (&ohci->pending))
                ohci_dbg(ohci, "abort schedule...\n");
        list_for_each_entry (priv, &ohci->pending, pending) {
                struct urb      *urb = priv->td[0]->urb;
                struct ed       *ed = priv->ed;

                switch (ed->state) {
                case ED_OPER:
                        ed->state = ED_UNLINK;
                        ed->hwINFO |= cpu_to_hc32(ohci, ED_DEQUEUE);
                        ed_deschedule (ohci, ed);

                        ed->ed_next = ohci->ed_rm_list;
                        ed->ed_prev = NULL;
                        ohci->ed_rm_list = ed;
                        /* FALLTHROUGH */
                case ED_UNLINK:
                        break;
                default:
                        ohci_dbg(ohci, "bogus ed %p state %d\n",
                                        ed, ed->state);
                }

                if (!urb->unlinked)
                        urb->unlinked = -ESHUTDOWN;
        }
        finish_unlinks (ohci, 0);
        spin_unlock_irq(&ohci->lock);

        /* paranoia, in case that didn't work: */

        /* empty the interrupt branches */
        for (i = 0; i < NUM_INTS; i++) ohci->load [i] = 0;
        for (i = 0; i < NUM_INTS; i++) ohci->hcca->int_table [i] = 0;

        /* no EDs to remove */
        ohci->ed_rm_list = NULL;

        /* empty control and bulk lists */
        ohci->ed_controltail = NULL;
        ohci->ed_bulktail    = NULL;

        if ((temp = ohci_run (ohci)) < 0) {
                ohci_err (ohci, "can't restart, %d\n", temp);
                return temp;
        }
        ohci_dbg(ohci, "restart complete\n");
        return 0;
}

#endif

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

MODULE_AUTHOR (DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE ("GPL");

#ifdef CONFIG_PCI
#include "ohci-pci.c"
#define PCI_DRIVER              ohci_pci_driver
#endif

#if defined(CONFIG_ARCH_SA1100) && defined(CONFIG_SA1111)
#include "ohci-sa1111.c"
#define SA1111_DRIVER           ohci_hcd_sa1111_driver
#endif

#if defined(CONFIG_ARCH_S3C24XX) || defined(CONFIG_ARCH_S3C64XX)
#include "ohci-s3c2410.c"
#define PLATFORM_DRIVER         ohci_hcd_s3c2410_driver
#endif

#ifdef CONFIG_USB_OHCI_EXYNOS
#include "ohci-exynos.c"
#define PLATFORM_DRIVER         exynos_ohci_driver
#endif

#ifdef CONFIG_USB_OHCI_HCD_OMAP1
#include "ohci-omap.c"
#define OMAP1_PLATFORM_DRIVER   ohci_hcd_omap_driver
#endif

#ifdef CONFIG_USB_OHCI_HCD_OMAP3
#include "ohci-omap3.c"
#define OMAP3_PLATFORM_DRIVER   ohci_hcd_omap3_driver
#endif

#if defined(CONFIG_PXA27x) || defined(CONFIG_PXA3xx)
#include "ohci-pxa27x.c"
#define PLATFORM_DRIVER         ohci_hcd_pxa27x_driver
#endif

#ifdef CONFIG_ARCH_EP93XX
#include "ohci-ep93xx.c"
#define PLATFORM_DRIVER         ohci_hcd_ep93xx_driver
#endif

#ifdef CONFIG_MIPS_ALCHEMY
#include "ohci-au1xxx.c"
#define PLATFORM_DRIVER         ohci_hcd_au1xxx_driver
#endif

#ifdef CONFIG_PNX8550
#include "ohci-pnx8550.c"
#define PLATFORM_DRIVER         ohci_hcd_pnx8550_driver
#endif

#ifdef CONFIG_USB_OHCI_HCD_PPC_SOC
#include "ohci-ppc-soc.c"
#define PLATFORM_DRIVER         ohci_hcd_ppc_soc_driver
#endif

#ifdef CONFIG_ARCH_AT91
#include "ohci-at91.c"
#define PLATFORM_DRIVER         ohci_hcd_at91_driver
#endif

#if defined(CONFIG_ARCH_PNX4008) || defined(CONFIG_ARCH_LPC32XX)
#include "ohci-nxp.c"
#define PLATFORM_DRIVER         usb_hcd_nxp_driver
#endif

#ifdef CONFIG_ARCH_DAVINCI_DA8XX
#include "ohci-da8xx.c"
#define PLATFORM_DRIVER         ohci_hcd_da8xx_driver
#endif

#ifdef CONFIG_USB_OHCI_SH
#include "ohci-sh.c"
#define PLATFORM_DRIVER         ohci_hcd_sh_driver
#endif


#ifdef CONFIG_USB_OHCI_HCD_PPC_OF
#include "ohci-ppc-of.c"
#define OF_PLATFORM_DRIVER      ohci_hcd_ppc_of_driver
#endif

#ifdef CONFIG_PLAT_SPEAR
#include "ohci-spear.c"
#define PLATFORM_DRIVER         spear_ohci_hcd_driver
#endif

#ifdef CONFIG_PPC_PS3
#include "ohci-ps3.c"
#define PS3_SYSTEM_BUS_DRIVER   ps3_ohci_driver
#endif

#ifdef CONFIG_MFD_SM501
#include "ohci-sm501.c"
#define SM501_OHCI_DRIVER       ohci_hcd_sm501_driver
#endif

#ifdef CONFIG_MFD_TC6393XB
#include "ohci-tmio.c"
#define TMIO_OHCI_DRIVER        ohci_hcd_tmio_driver
#endif

#ifdef CONFIG_MACH_JZ4740
#include "ohci-jz4740.c"
#define PLATFORM_DRIVER ohci_hcd_jz4740_driver
#endif

#ifdef CONFIG_USB_OCTEON_OHCI
#include "ohci-octeon.c"
#define PLATFORM_DRIVER         ohci_octeon_driver
#endif

#ifdef CONFIG_TILE_USB
#include "ohci-tilegx.c"
#define PLATFORM_DRIVER         ohci_hcd_tilegx_driver
#endif

#ifdef CONFIG_USB_CNS3XXX_OHCI
#include "ohci-cns3xxx.c"
#define PLATFORM_DRIVER         ohci_hcd_cns3xxx_driver
#endif

#ifdef CONFIG_CPU_XLR
#include "ohci-xls.c"
#define PLATFORM_DRIVER         ohci_xls_driver
#endif

#ifdef CONFIG_USB_OHCI_HCD_PLATFORM
#include "ohci-platform.c"
#define PLATFORM_DRIVER         ohci_platform_driver
#endif

#if     !defined(PCI_DRIVER) &&         \
        !defined(PLATFORM_DRIVER) &&    \
        !defined(OMAP1_PLATFORM_DRIVER) &&      \
        !defined(OMAP3_PLATFORM_DRIVER) &&      \
        !defined(OF_PLATFORM_DRIVER) && \
        !defined(SA1111_DRIVER) &&      \
        !defined(PS3_SYSTEM_BUS_DRIVER) && \
        !defined(SM501_OHCI_DRIVER) && \
        !defined(TMIO_OHCI_DRIVER)
#error "missing bus glue for ohci-hcd"
#endif

static int __init ohci_hcd_mod_init(void)
{
        int retval = 0;

        if (usb_disabled())
                return -ENODEV;

        printk(KERN_INFO "%s: " DRIVER_DESC "\n", hcd_name);
        pr_debug ("%s: block sizes: ed %Zd td %Zd\n", hcd_name,
                sizeof (struct ed), sizeof (struct td));
        set_bit(USB_OHCI_LOADED, &usb_hcds_loaded);

#ifdef DEBUG
        ohci_debug_root = debugfs_create_dir("ohci", usb_debug_root);
        if (!ohci_debug_root) {
                retval = -ENOENT;
                goto error_debug;
        }
#endif

#ifdef PS3_SYSTEM_BUS_DRIVER
        retval = ps3_ohci_driver_register(&PS3_SYSTEM_BUS_DRIVER);
        if (retval < 0)
                goto error_ps3;
#endif

#ifdef PLATFORM_DRIVER
        retval = platform_driver_register(&PLATFORM_DRIVER);
        if (retval < 0)
                goto error_platform;
#endif

#ifdef OMAP1_PLATFORM_DRIVER
        retval = platform_driver_register(&OMAP1_PLATFORM_DRIVER);
        if (retval < 0)
                goto error_omap1_platform;
#endif

#ifdef OMAP3_PLATFORM_DRIVER
        retval = platform_driver_register(&OMAP3_PLATFORM_DRIVER);
        if (retval < 0)
                goto error_omap3_platform;
#endif

#ifdef OF_PLATFORM_DRIVER
        retval = platform_driver_register(&OF_PLATFORM_DRIVER);
        if (retval < 0)
                goto error_of_platform;
#endif

#ifdef SA1111_DRIVER
        retval = sa1111_driver_register(&SA1111_DRIVER);
        if (retval < 0)
                goto error_sa1111;
#endif

#ifdef PCI_DRIVER
        retval = pci_register_driver(&PCI_DRIVER);
        if (retval < 0)
                goto error_pci;
#endif

#ifdef SM501_OHCI_DRIVER
        retval = platform_driver_register(&SM501_OHCI_DRIVER);
        if (retval < 0)
                goto error_sm501;
#endif

#ifdef TMIO_OHCI_DRIVER
        retval = platform_driver_register(&TMIO_OHCI_DRIVER);
        if (retval < 0)
                goto error_tmio;
#endif

        return retval;

        /* Error path */
#ifdef TMIO_OHCI_DRIVER
        platform_driver_unregister(&TMIO_OHCI_DRIVER);
 error_tmio:
#endif
#ifdef SM501_OHCI_DRIVER
        platform_driver_unregister(&SM501_OHCI_DRIVER);
 error_sm501:
#endif
#ifdef PCI_DRIVER
        pci_unregister_driver(&PCI_DRIVER);
 error_pci:
#endif
#ifdef SA1111_DRIVER
        sa1111_driver_unregister(&SA1111_DRIVER);
 error_sa1111:
#endif
#ifdef OF_PLATFORM_DRIVER
        platform_driver_unregister(&OF_PLATFORM_DRIVER);
 error_of_platform:
#endif
#ifdef PLATFORM_DRIVER
        platform_driver_unregister(&PLATFORM_DRIVER);
 error_platform:
#endif
#ifdef OMAP1_PLATFORM_DRIVER
        platform_driver_unregister(&OMAP1_PLATFORM_DRIVER);
 error_omap1_platform:
#endif
#ifdef OMAP3_PLATFORM_DRIVER
        platform_driver_unregister(&OMAP3_PLATFORM_DRIVER);
 error_omap3_platform:
#endif
#ifdef PS3_SYSTEM_BUS_DRIVER
        ps3_ohci_driver_unregister(&PS3_SYSTEM_BUS_DRIVER);
 error_ps3:
#endif
#ifdef DEBUG
        debugfs_remove(ohci_debug_root);
        ohci_debug_root = NULL;
 error_debug:
#endif

        clear_bit(USB_OHCI_LOADED, &usb_hcds_loaded);
        return retval;
}
module_init(ohci_hcd_mod_init);

static void __exit ohci_hcd_mod_exit(void)
{
#ifdef TMIO_OHCI_DRIVER
        platform_driver_unregister(&TMIO_OHCI_DRIVER);
#endif
#ifdef SM501_OHCI_DRIVER
        platform_driver_unregister(&SM501_OHCI_DRIVER);
#endif
#ifdef PCI_DRIVER
        pci_unregister_driver(&PCI_DRIVER);
#endif
#ifdef SA1111_DRIVER
        sa1111_driver_unregister(&SA1111_DRIVER);
#endif
#ifdef OF_PLATFORM_DRIVER
        platform_driver_unregister(&OF_PLATFORM_DRIVER);
#endif
#ifdef PLATFORM_DRIVER
        platform_driver_unregister(&PLATFORM_DRIVER);
#endif
#ifdef OMAP3_PLATFORM_DRIVER
        platform_driver_unregister(&OMAP3_PLATFORM_DRIVER);
#endif
#ifdef PS3_SYSTEM_BUS_DRIVER
        ps3_ohci_driver_unregister(&PS3_SYSTEM_BUS_DRIVER);
#endif
#ifdef DEBUG
        debugfs_remove(ohci_debug_root);
#endif
        clear_bit(USB_OHCI_LOADED, &usb_hcds_loaded);
}
module_exit(ohci_hcd_mod_exit);