Linux-2.6.12-rc2

[mirror_ubuntu-artful-kernel.git] / drivers / usb / host / ohci-hcd.c

/*
 * OHCI HCD (Host Controller Driver) for USB.
 *
 * (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.
 *
 * History:
 * 
 * 2004/03/24 LH7A404 support (Durgesh Pattamatta & Marc Singer)
 * 2004/02/04 use generic dma_* functions instead of pci_* (dsaxena@plexity.net)
 * 2003/02/24 show registers in sysfs (Kevin Brosius)
 *
 * 2002/09/03 get rid of ed hashtables, rework periodic scheduling and
 *      bandwidth accounting; if debugging, show schedules in driverfs
 * 2002/07/19 fixes to management of ED and schedule state.
 * 2002/06/09 SA-1111 support (Christopher Hoover)
 * 2002/06/01 remember frame when HC won't see EDs any more; use that info
 *      to fix urb unlink races caused by interrupt latency assumptions;
 *      minor ED field and function naming updates
 * 2002/01/18 package as a patch for 2.5.3; this should match the
 *      2.4.17 kernel modulo some bugs being fixed.
 *
 * 2001/10/18 merge pmac cleanup (Benjamin Herrenschmidt) and bugfixes
 *      from post-2.4.5 patches.
 * 2001/09/20 URB_ZERO_PACKET support; hcca_dma portability, OPTi warning
 * 2001/09/07 match PCI PM changes, errnos from Linus' tree
 * 2001/05/05 fork 2.4.5 version into "hcd" framework, cleanup, simplify;
 *      pbook pci quirks gone (please fix pbook pci sw!) (db)
 *
 * 2001/04/08 Identify version on module load (gb)
 * 2001/03/24 td/ed hashing to remove bus_to_virt (Steve Longerbeam);
        pci_map_single (db)
 * 2001/03/21 td and dev/ed allocation uses new pci_pool API (db)
 * 2001/03/07 hcca allocation uses pci_alloc_consistent (Steve Longerbeam)
 *
 * 2000/09/26 fixed races in removing the private portion of the urb
 * 2000/09/07 disable bulk and control lists when unlinking the last
 *      endpoint descriptor in order to avoid unrecoverable errors on
 *      the Lucent chips. (rwc@sgi)
 * 2000/08/29 use bandwidth claiming hooks (thanks Randy!), fix some
 *      urb unlink probs, indentation fixes
 * 2000/08/11 various oops fixes mostly affecting iso and cleanup from
 *      device unplugs.
 * 2000/06/28 use PCI hotplug framework, for better power management
 *      and for Cardbus support (David Brownell)
 * 2000/earlier:  fixes for NEC/Lucent chips; suspend/resume handling
 *      when the controller loses power; handle UE; cleanup; ...
 *
 * v5.2 1999/12/07 URB 3rd preview, 
 * v5.1 1999/11/30 URB 2nd preview, cpia, (usb-scsi)
 * v5.0 1999/11/22 URB Technical preview, Paul Mackerras powerbook susp/resume 
 *      i386: HUB, Keyboard, Mouse, Printer 
 *
 * v4.3 1999/10/27 multiple HCs, bulk_request
 * v4.2 1999/09/05 ISO API alpha, new dev alloc, neg Error-codes
 * v4.1 1999/08/27 Randy Dunlap's - ISO API first impl.
 * v4.0 1999/08/18 
 * v3.0 1999/06/25 
 * v2.1 1999/05/09  code clean up
 * v2.0 1999/05/04 
 * v1.0 1999/04/27 initial release
 *
 * This file is licenced under the GPL.
 */
 
#include <linux/config.h>

#ifdef CONFIG_USB_DEBUG
#       define DEBUG
#else
#       undef DEBUG
#endif

#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/smp_lock.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/timer.h>
#include <linux/list.h>
#include <linux/interrupt.h>  /* for in_interrupt () */
#include <linux/usb.h>
#include <linux/usb_otg.h>
#include "../core/hcd.h"
#include <linux/dma-mapping.h> 
#include <linux/dmapool.h>    /* needed by ohci-mem.c when no PCI */

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


#define DRIVER_VERSION "2004 Nov 08"
#define DRIVER_AUTHOR "Roman Weissgaerber, David Brownell"
#define DRIVER_DESC "USB 1.1 'Open' Host Controller (OHCI) Driver"

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

// #define 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_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";

#include "ohci.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);

#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 int 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 int 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 usb_host_endpoint *ep,
        struct urb      *urb,
        int             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));
#endif
        
        /* every endpoint has a ed, locate and maybe (re)initialize it */
        if (! (ed = ed_get (ohci, 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 upto 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 = kmalloc (sizeof (urb_priv_t) + size * sizeof (struct td *),
                        mem_flags);
        if (!urb_priv)
                return -ENOMEM;
        memset (urb_priv, 0, sizeof (urb_priv_t) + size * sizeof (struct td *));
        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 (!HC_IS_RUNNING(hcd->state)) {
                retval = -ENODEV;
                goto fail;
        }

        /* in case of unlink-during-submit */
        spin_lock (&urb->lock);
        if (urb->status != -EINPROGRESS) {
                spin_unlock (&urb->lock);
                urb->hcpriv = urb_priv;
                finish_urb (ohci, urb, NULL);
                retval = 0;
                goto fail;
        }

        /* schedule the ed if needed */
        if (ed->state == ED_IDLE) {
                retval = ed_schedule (ohci, ed);
                if (retval < 0)
                        goto fail0;
                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);

fail0:
        spin_unlock (&urb->lock);
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); it's
 * already marked using urb->status.  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)
{
        struct ohci_hcd         *ohci = hcd_to_ohci (hcd);
        unsigned long           flags;
        
#ifdef OHCI_VERBOSE_DEBUG
        urb_print (urb, "UNLINK", 1);
#endif            

        spin_lock_irqsave (&ohci->lock, flags);
        if (HC_IS_RUNNING(hcd->state)) {
                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, NULL);
        }
        spin_unlock_irqrestore (&ohci->lock, flags);
        return 0;
}

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

/* 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 (!HC_IS_RUNNING (hcd->state)) {
sanitize:
                ed->state = ED_IDLE;
                finish_unlinks (ohci, 0, NULL);
        }

        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, "IRQ INTR_SF lossage\n");
                        goto sanitize;
                }
                spin_unlock_irqrestore (&ohci->lock, flags);
                set_current_state (TASK_UNINTERRUPTIBLE);
                schedule_timeout (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);
        return;
}

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);
}

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

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

static int ohci_init (struct ohci_hcd *ohci)
{
        int ret;

        disable (ohci);
        ohci->regs = ohci_to_hcd(ohci)->regs;
        ohci->next_statechange = jiffies;

#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
        (void) ohci_readl (ohci, &ohci->regs->control);

        if (ohci->hcca)
                return 0;

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

        if ((ret = ohci_mem_init (ohci)) < 0)
                ohci_stop (ohci_to_hcd(ohci));

        return ret;

}

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

/* Start an OHCI controller, set the BUS operational
 * resets USB and controller
 * enable interrupts 
 * connect the virtual root hub
 */
static int ohci_run (struct ohci_hcd *ohci)
{
        u32                     mask, temp;
        struct usb_device       *udev;
        struct usb_bus          *bus;
        int                     first = ohci->fminterval == 0;

        disable (ohci);

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

                temp = ohci_readl (ohci, &ohci->regs->fminterval);
                ohci->fminterval = temp & 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
         * saved if boot firmware (BIOS/SMM/...) told us it's connected
         * (for OHCI integrated on mainboard, it normally is)
         */
        ohci->hc_control = ohci_readl (ohci, &ohci->regs->control);
        ohci_dbg (ohci, "resetting from state '%s', control = 0x%x\n",
                        hcfs2string (ohci->hc_control & OHCI_CTRL_HCFS),
                        ohci->hc_control);

        if (ohci->hc_control & OHCI_CTRL_RWC
                        && !(ohci->flags & OHCI_QUIRK_AMD756))
                ohci_to_hcd(ohci)->can_wakeup = 1;

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

                /* power down each port */
                for (temp = 0; temp < ports; temp++)
                        ohci_writel (ohci, RH_PS_LSDA,
                                &ohci->regs->roothub.portstatus [temp]);
        }
        // flush those writes
        (void) ohci_readl (ohci, &ohci->regs->control);
        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);
        temp = 30;      /* ... allow extra time */
        while ((ohci_readl (ohci, &ohci->regs->cmdstatus) & OHCI_HCR) != 0) {
                if (--temp == 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;
        }

        /* 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_to_hcd(ohci)->state = HC_STATE_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, mask, &ohci->regs->intrstatus);
        ohci_writel (ohci, mask, &ohci->regs->intrenable);

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

        spin_unlock_irq (&ohci->lock);

        // POTPGT delay is bits 24-31, in 2 ms units.
        mdelay ((temp >> 23) & 0x1fe);
        bus = &ohci_to_hcd(ohci)->self;
        ohci_to_hcd(ohci)->state = HC_STATE_RUNNING;

        ohci_dump (ohci, 1);

        udev = bus->root_hub;
        if (udev) {
                return 0;
        }
 
        /* connect the virtual root hub */
        udev = usb_alloc_dev (NULL, bus, 0);
        if (!udev) {
                disable (ohci);
                ohci->hc_control &= ~OHCI_CTRL_HCFS;
                ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
                return -ENOMEM;
        }

        udev->speed = USB_SPEED_FULL;
        if (usb_hcd_register_root_hub (udev, ohci_to_hcd(ohci)) != 0) {
                usb_put_dev (udev);
                disable (ohci);
                ohci->hc_control &= ~OHCI_CTRL_HCFS;
                ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
                return -ENODEV;
        }
        if (ohci->power_budget)
                hub_set_power_budget(udev, ohci->power_budget);

        create_debug_files (ohci);
        return 0;
}

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

/* an interrupt happens */

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

        /* we can eliminate a (slow) ohci_readl()
           if _only_ WDH caused this irq */
        if ((ohci->hcca->done_head != 0)
                        && ! (hc32_to_cpup (ohci, &ohci->hcca->done_head)
                                & 0x01)) {
                ints =  OHCI_INTR_WDH;

        /* cardbus/... hardware gone before remove() */
        } else if ((ints = ohci_readl (ohci, &regs->intrstatus)) == ~(u32)0) {
                disable (ohci);
                ohci_dbg (ohci, "device removed!\n");
                return IRQ_HANDLED;

        /* interrupt for some other device? */
        } else if ((ints &= ohci_readl (ohci, &regs->intrenable)) == 0) {
                return IRQ_NOTMINE;
        } 

        if (ints & OHCI_INTR_UE) {
                disable (ohci);
                ohci_err (ohci, "OHCI Unrecoverable Error, disabled\n");
                // e.g. due to PCI Master/Target Abort

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

        if (ints & OHCI_INTR_RD) {
                ohci_vdbg (ohci, "resume detect\n");
                if (hcd->state != HC_STATE_QUIESCING)
                        schedule_work(&ohci->rh_resume);
        }

        if (ints & OHCI_INTR_WDH) {
                if (HC_IS_RUNNING(hcd->state))
                        ohci_writel (ohci, OHCI_INTR_WDH, &regs->intrdisable);  
                spin_lock (&ohci->lock);
                dl_done_list (ohci, ptregs);
                spin_unlock (&ohci->lock);
                if (HC_IS_RUNNING(hcd->state))
                        ohci_writel (ohci, OHCI_INTR_WDH, &regs->intrenable); 
        }
  
        /* 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), ptregs);
        if ((ints & OHCI_INTR_SF) != 0 && !ohci->ed_rm_list
                        && HC_IS_RUNNING(hcd->state))
                ohci_writel (ohci, OHCI_INTR_SF, &regs->intrdisable);   
        spin_unlock (&ohci->lock);

        if (HC_IS_RUNNING(hcd->state)) {
                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_dbg (ohci, "stop %s controller (state 0x%02x)\n",
                hcfs2string (ohci->hc_control & OHCI_CTRL_HCFS),
                hcd->state);
        ohci_dump (ohci, 1);

        flush_scheduled_work();

        ohci_usb_reset (ohci);
        ohci_writel (ohci, OHCI_INTR_MIE, &ohci->regs->intrdisable);
        
        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;
        }
}

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

/* must not be called from interrupt context */

#if     defined(CONFIG_USB_SUSPEND) || defined(CONFIG_PM)

static int ohci_restart (struct ohci_hcd *ohci)
{
        int temp;
        int i;
        struct urb_priv *priv;
        struct usb_device *root = ohci_to_hcd(ohci)->self.root_hub;

        /* mark any devices gone, so they do nothing till khubd disconnects.
         * recycle any "live" eds/tds (and urbs) right away.
         * later, khubd disconnect processing will recycle the other state,
         * (either as disconnect/reconnect, or maybe someday as a reset).
         */ 
        spin_lock_irq(&ohci->lock);
        disable (ohci);
        for (i = 0; i < root->maxchild; i++) {
                if (root->children [i])
                        usb_set_device_state (root->children[i],
                                USB_STATE_NOTATTACHED);
        }
        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);
                }

                spin_lock (&urb->lock);
                urb->status = -ESHUTDOWN;
                spin_unlock (&urb->lock);
        }
        finish_unlinks (ohci, 0, NULL);
        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;
        } else {
                /* here we "know" root ports should always stay powered,
                 * and that if we try to turn them back on the root hub
                 * will respond to CSC processing.
                 */
                i = roothub_a (ohci) & RH_A_NDP;
                while (i--)
                        ohci_writel (ohci, RH_PS_PSS,
                                &ohci->regs->roothub.portstatus [temp]);
                ohci_dbg (ohci, "restart complete\n");
        }
        return 0;
}
#endif

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

#define DRIVER_INFO DRIVER_VERSION " " DRIVER_DESC

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

#ifdef CONFIG_PCI
#include "ohci-pci.c"
#endif

#ifdef CONFIG_SA1111
#include "ohci-sa1111.c"
#endif

#ifdef CONFIG_ARCH_OMAP
#include "ohci-omap.c"
#endif

#ifdef CONFIG_ARCH_LH7A404
#include "ohci-lh7a404.c"
#endif

#ifdef CONFIG_PXA27x
#include "ohci-pxa27x.c"
#endif

#ifdef CONFIG_SOC_AU1X00
#include "ohci-au1xxx.c"
#endif

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

#if !(defined(CONFIG_PCI) \
      || defined(CONFIG_SA1111) \
      || defined(CONFIG_ARCH_OMAP) \
      || defined (CONFIG_ARCH_LH7A404) \
      || defined (CONFIG_PXA27x) \
      || defined (CONFIG_SOC_AU1X00) \
      || defined (CONFIG_USB_OHCI_HCD_PPC_SOC) \
        )
#error "missing bus glue for ohci-hcd"
#endif