PM / sleep: Asynchronous threads for suspend_noirq

[linux/fpc-iii.git] / drivers / usb / host / uhci-hcd.c

/*
 * Universal Host Controller Interface driver for USB.
 *
 * Maintainer: Alan Stern <stern@rowland.harvard.edu>
 *
 * (C) Copyright 1999 Linus Torvalds
 * (C) Copyright 1999-2002 Johannes Erdfelt, johannes@erdfelt.com
 * (C) Copyright 1999 Randy Dunlap
 * (C) Copyright 1999 Georg Acher, acher@in.tum.de
 * (C) Copyright 1999 Deti Fliegl, deti@fliegl.de
 * (C) Copyright 1999 Thomas Sailer, sailer@ife.ee.ethz.ch
 * (C) Copyright 1999 Roman Weissgaerber, weissg@vienna.at
 * (C) Copyright 2000 Yggdrasil Computing, Inc. (port of new PCI interface
 *               support from usb-ohci.c by Adam Richter, adam@yggdrasil.com).
 * (C) Copyright 1999 Gregory P. Smith (from usb-ohci.c)
 * (C) Copyright 2004-2007 Alan Stern, stern@rowland.harvard.edu
 *
 * Intel documents this fairly well, and as far as I know there
 * are no royalties or anything like that, but even so there are
 * people who decided that they want to do the same thing in a
 * completely different way.
 *
 */

#include <linux/module.h>
#include <linux/pci.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/ioport.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/unistd.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/debugfs.h>
#include <linux/pm.h>
#include <linux/dmapool.h>
#include <linux/dma-mapping.h>
#include <linux/usb.h>
#include <linux/usb/hcd.h>
#include <linux/bitops.h>
#include <linux/dmi.h>

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

#include "uhci-hcd.h"

/*
 * Version Information
 */
#define DRIVER_AUTHOR                                                   \
        "Linus 'Frodo Rabbit' Torvalds, Johannes Erdfelt, "             \
        "Randy Dunlap, Georg Acher, Deti Fliegl, Thomas Sailer, "       \
        "Roman Weissgaerber, Alan Stern"
#define DRIVER_DESC "USB Universal Host Controller Interface driver"

/* for flakey hardware, ignore overcurrent indicators */
static bool ignore_oc;
module_param(ignore_oc, bool, S_IRUGO);
MODULE_PARM_DESC(ignore_oc, "ignore hardware overcurrent indications");

/*
 * debug = 0, no debugging messages
 * debug = 1, dump failed URBs except for stalls
 * debug = 2, dump all failed URBs (including stalls)
 *            show all queues in /sys/kernel/debug/uhci/[pci_addr]
 * debug = 3, show all TDs in URBs when dumping
 */
#ifdef CONFIG_DYNAMIC_DEBUG

static int debug = 1;
module_param(debug, int, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(debug, "Debug level");
static char *errbuf;

#else

#define debug 0
#define errbuf NULL

#endif


#define ERRBUF_LEN    (32 * 1024)

static struct kmem_cache *uhci_up_cachep;       /* urb_priv */

static void suspend_rh(struct uhci_hcd *uhci, enum uhci_rh_state new_state);
static void wakeup_rh(struct uhci_hcd *uhci);
static void uhci_get_current_frame_number(struct uhci_hcd *uhci);

/*
 * Calculate the link pointer DMA value for the first Skeleton QH in a frame.
 */
static __hc32 uhci_frame_skel_link(struct uhci_hcd *uhci, int frame)
{
        int skelnum;

        /*
         * The interrupt queues will be interleaved as evenly as possible.
         * There's not much to be done about period-1 interrupts; they have
         * to occur in every frame.  But we can schedule period-2 interrupts
         * in odd-numbered frames, period-4 interrupts in frames congruent
         * to 2 (mod 4), and so on.  This way each frame only has two
         * interrupt QHs, which will help spread out bandwidth utilization.
         *
         * ffs (Find First bit Set) does exactly what we need:
         * 1,3,5,...  => ffs = 0 => use period-2 QH = skelqh[8],
         * 2,6,10,... => ffs = 1 => use period-4 QH = skelqh[7], etc.
         * ffs >= 7 => not on any high-period queue, so use
         *      period-1 QH = skelqh[9].
         * Add in UHCI_NUMFRAMES to insure at least one bit is set.
         */
        skelnum = 8 - (int) __ffs(frame | UHCI_NUMFRAMES);
        if (skelnum <= 1)
                skelnum = 9;
        return LINK_TO_QH(uhci, uhci->skelqh[skelnum]);
}

#include "uhci-debug.c"
#include "uhci-q.c"
#include "uhci-hub.c"

/*
 * Finish up a host controller reset and update the recorded state.
 */
static void finish_reset(struct uhci_hcd *uhci)
{
        int port;

        /* HCRESET doesn't affect the Suspend, Reset, and Resume Detect
         * bits in the port status and control registers.
         * We have to clear them by hand.
         */
        for (port = 0; port < uhci->rh_numports; ++port)
                uhci_writew(uhci, 0, USBPORTSC1 + (port * 2));

        uhci->port_c_suspend = uhci->resuming_ports = 0;
        uhci->rh_state = UHCI_RH_RESET;
        uhci->is_stopped = UHCI_IS_STOPPED;
        clear_bit(HCD_FLAG_POLL_RH, &uhci_to_hcd(uhci)->flags);
}

/*
 * Last rites for a defunct/nonfunctional controller
 * or one we don't want to use any more.
 */
static void uhci_hc_died(struct uhci_hcd *uhci)
{
        uhci_get_current_frame_number(uhci);
        uhci->reset_hc(uhci);
        finish_reset(uhci);
        uhci->dead = 1;

        /* The current frame may already be partway finished */
        ++uhci->frame_number;
}

/*
 * Initialize a controller that was newly discovered or has lost power
 * or otherwise been reset while it was suspended.  In none of these cases
 * can we be sure of its previous state.
 */
static void check_and_reset_hc(struct uhci_hcd *uhci)
{
        if (uhci->check_and_reset_hc(uhci))
                finish_reset(uhci);
}

#if defined(CONFIG_USB_UHCI_SUPPORT_NON_PCI_HC)
/*
 * The two functions below are generic reset functions that are used on systems
 * that do not have keyboard and mouse legacy support. We assume that we are
 * running on such a system if CONFIG_USB_UHCI_SUPPORT_NON_PCI_HC is defined.
 */

/*
 * Make sure the controller is completely inactive, unable to
 * generate interrupts or do DMA.
 */
static void uhci_generic_reset_hc(struct uhci_hcd *uhci)
{
        /* Reset the HC - this will force us to get a
         * new notification of any already connected
         * ports due to the virtual disconnect that it
         * implies.
         */
        uhci_writew(uhci, USBCMD_HCRESET, USBCMD);
        mb();
        udelay(5);
        if (uhci_readw(uhci, USBCMD) & USBCMD_HCRESET)
                dev_warn(uhci_dev(uhci), "HCRESET not completed yet!\n");

        /* Just to be safe, disable interrupt requests and
         * make sure the controller is stopped.
         */
        uhci_writew(uhci, 0, USBINTR);
        uhci_writew(uhci, 0, USBCMD);
}

/*
 * Initialize a controller that was newly discovered or has just been
 * resumed.  In either case we can't be sure of its previous state.
 *
 * Returns: 1 if the controller was reset, 0 otherwise.
 */
static int uhci_generic_check_and_reset_hc(struct uhci_hcd *uhci)
{
        unsigned int cmd, intr;

        /*
         * When restarting a suspended controller, we expect all the
         * settings to be the same as we left them:
         *
         *      Controller is stopped and configured with EGSM set;
         *      No interrupts enabled except possibly Resume Detect.
         *
         * If any of these conditions are violated we do a complete reset.
         */

        cmd = uhci_readw(uhci, USBCMD);
        if ((cmd & USBCMD_RS) || !(cmd & USBCMD_CF) || !(cmd & USBCMD_EGSM)) {
                dev_dbg(uhci_dev(uhci), "%s: cmd = 0x%04x\n",
                                __func__, cmd);
                goto reset_needed;
        }

        intr = uhci_readw(uhci, USBINTR);
        if (intr & (~USBINTR_RESUME)) {
                dev_dbg(uhci_dev(uhci), "%s: intr = 0x%04x\n",
                                __func__, intr);
                goto reset_needed;
        }
        return 0;

reset_needed:
        dev_dbg(uhci_dev(uhci), "Performing full reset\n");
        uhci_generic_reset_hc(uhci);
        return 1;
}
#endif /* CONFIG_USB_UHCI_SUPPORT_NON_PCI_HC */

/*
 * Store the basic register settings needed by the controller.
 */
static void configure_hc(struct uhci_hcd *uhci)
{
        /* Set the frame length to the default: 1 ms exactly */
        uhci_writeb(uhci, USBSOF_DEFAULT, USBSOF);

        /* Store the frame list base address */
        uhci_writel(uhci, uhci->frame_dma_handle, USBFLBASEADD);

        /* Set the current frame number */
        uhci_writew(uhci, uhci->frame_number & UHCI_MAX_SOF_NUMBER,
                        USBFRNUM);

        /* perform any arch/bus specific configuration */
        if (uhci->configure_hc)
                uhci->configure_hc(uhci);
}

static int resume_detect_interrupts_are_broken(struct uhci_hcd *uhci)
{
        /* If we have to ignore overcurrent events then almost by definition
         * we can't depend on resume-detect interrupts. */
        if (ignore_oc)
                return 1;

        return uhci->resume_detect_interrupts_are_broken ?
                uhci->resume_detect_interrupts_are_broken(uhci) : 0;
}

static int global_suspend_mode_is_broken(struct uhci_hcd *uhci)
{
        return uhci->global_suspend_mode_is_broken ?
                uhci->global_suspend_mode_is_broken(uhci) : 0;
}

static void suspend_rh(struct uhci_hcd *uhci, enum uhci_rh_state new_state)
__releases(uhci->lock)
__acquires(uhci->lock)
{
        int auto_stop;
        int int_enable, egsm_enable, wakeup_enable;
        struct usb_device *rhdev = uhci_to_hcd(uhci)->self.root_hub;

        auto_stop = (new_state == UHCI_RH_AUTO_STOPPED);
        dev_dbg(&rhdev->dev, "%s%s\n", __func__,
                        (auto_stop ? " (auto-stop)" : ""));

        /* Start off by assuming Resume-Detect interrupts and EGSM work
         * and that remote wakeups should be enabled.
         */
        egsm_enable = USBCMD_EGSM;
        int_enable = USBINTR_RESUME;
        wakeup_enable = 1;

        /*
         * In auto-stop mode, we must be able to detect new connections.
         * The user can force us to poll by disabling remote wakeup;
         * otherwise we will use the EGSM/RD mechanism.
         */
        if (auto_stop) {
                if (!device_may_wakeup(&rhdev->dev))
                        egsm_enable = int_enable = 0;
        }

#ifdef CONFIG_PM
        /*
         * In bus-suspend mode, we use the wakeup setting specified
         * for the root hub.
         */
        else {
                if (!rhdev->do_remote_wakeup)
                        wakeup_enable = 0;
        }
#endif

        /*
         * UHCI doesn't distinguish between wakeup requests from downstream
         * devices and local connect/disconnect events.  There's no way to
         * enable one without the other; both are controlled by EGSM.  Thus
         * if wakeups are disallowed then EGSM must be turned off -- in which
         * case remote wakeup requests from downstream during system sleep
         * will be lost.
         *
         * In addition, if EGSM is broken then we can't use it.  Likewise,
         * if Resume-Detect interrupts are broken then we can't use them.
         *
         * Finally, neither EGSM nor RD is useful by itself.  Without EGSM,
         * the RD status bit will never get set.  Without RD, the controller
         * won't generate interrupts to tell the system about wakeup events.
         */
        if (!wakeup_enable || global_suspend_mode_is_broken(uhci) ||
                        resume_detect_interrupts_are_broken(uhci))
                egsm_enable = int_enable = 0;

        uhci->RD_enable = !!int_enable;
        uhci_writew(uhci, int_enable, USBINTR);
        uhci_writew(uhci, egsm_enable | USBCMD_CF, USBCMD);
        mb();
        udelay(5);

        /* If we're auto-stopping then no devices have been attached
         * for a while, so there shouldn't be any active URBs and the
         * controller should stop after a few microseconds.  Otherwise
         * we will give the controller one frame to stop.
         */
        if (!auto_stop && !(uhci_readw(uhci, USBSTS) & USBSTS_HCH)) {
                uhci->rh_state = UHCI_RH_SUSPENDING;
                spin_unlock_irq(&uhci->lock);
                msleep(1);
                spin_lock_irq(&uhci->lock);
                if (uhci->dead)
                        return;
        }
        if (!(uhci_readw(uhci, USBSTS) & USBSTS_HCH))
                dev_warn(uhci_dev(uhci), "Controller not stopped yet!\n");

        uhci_get_current_frame_number(uhci);

        uhci->rh_state = new_state;
        uhci->is_stopped = UHCI_IS_STOPPED;

        /*
         * If remote wakeup is enabled but either EGSM or RD interrupts
         * doesn't work, then we won't get an interrupt when a wakeup event
         * occurs.  Thus the suspended root hub needs to be polled.
         */
        if (wakeup_enable && (!int_enable || !egsm_enable))
                set_bit(HCD_FLAG_POLL_RH, &uhci_to_hcd(uhci)->flags);
        else
                clear_bit(HCD_FLAG_POLL_RH, &uhci_to_hcd(uhci)->flags);

        uhci_scan_schedule(uhci);
        uhci_fsbr_off(uhci);
}

static void start_rh(struct uhci_hcd *uhci)
{
        uhci->is_stopped = 0;

        /* Mark it configured and running with a 64-byte max packet.
         * All interrupts are enabled, even though RESUME won't do anything.
         */
        uhci_writew(uhci, USBCMD_RS | USBCMD_CF | USBCMD_MAXP, USBCMD);
        uhci_writew(uhci, USBINTR_TIMEOUT | USBINTR_RESUME |
                USBINTR_IOC | USBINTR_SP, USBINTR);
        mb();
        uhci->rh_state = UHCI_RH_RUNNING;
        set_bit(HCD_FLAG_POLL_RH, &uhci_to_hcd(uhci)->flags);
}

static void wakeup_rh(struct uhci_hcd *uhci)
__releases(uhci->lock)
__acquires(uhci->lock)
{
        dev_dbg(&uhci_to_hcd(uhci)->self.root_hub->dev,
                        "%s%s\n", __func__,
                        uhci->rh_state == UHCI_RH_AUTO_STOPPED ?
                                " (auto-start)" : "");

        /* If we are auto-stopped then no devices are attached so there's
         * no need for wakeup signals.  Otherwise we send Global Resume
         * for 20 ms.
         */
        if (uhci->rh_state == UHCI_RH_SUSPENDED) {
                unsigned egsm;

                /* Keep EGSM on if it was set before */
                egsm = uhci_readw(uhci, USBCMD) & USBCMD_EGSM;
                uhci->rh_state = UHCI_RH_RESUMING;
                uhci_writew(uhci, USBCMD_FGR | USBCMD_CF | egsm, USBCMD);
                spin_unlock_irq(&uhci->lock);
                msleep(20);
                spin_lock_irq(&uhci->lock);
                if (uhci->dead)
                        return;

                /* End Global Resume and wait for EOP to be sent */
                uhci_writew(uhci, USBCMD_CF, USBCMD);
                mb();
                udelay(4);
                if (uhci_readw(uhci, USBCMD) & USBCMD_FGR)
                        dev_warn(uhci_dev(uhci), "FGR not stopped yet!\n");
        }

        start_rh(uhci);

        /* Restart root hub polling */
        mod_timer(&uhci_to_hcd(uhci)->rh_timer, jiffies);
}

static irqreturn_t uhci_irq(struct usb_hcd *hcd)
{
        struct uhci_hcd *uhci = hcd_to_uhci(hcd);
        unsigned short status;

        /*
         * Read the interrupt status, and write it back to clear the
         * interrupt cause.  Contrary to the UHCI specification, the
         * "HC Halted" status bit is persistent: it is RO, not R/WC.
         */
        status = uhci_readw(uhci, USBSTS);
        if (!(status & ~USBSTS_HCH))    /* shared interrupt, not mine */
                return IRQ_NONE;
        uhci_writew(uhci, status, USBSTS);              /* Clear it */

        spin_lock(&uhci->lock);
        if (unlikely(!uhci->is_initialized))    /* not yet configured */
                goto done;

        if (status & ~(USBSTS_USBINT | USBSTS_ERROR | USBSTS_RD)) {
                if (status & USBSTS_HSE)
                        dev_err(uhci_dev(uhci),
                                "host system error, PCI problems?\n");
                if (status & USBSTS_HCPE)
                        dev_err(uhci_dev(uhci),
                                "host controller process error, something bad happened!\n");
                if (status & USBSTS_HCH) {
                        if (uhci->rh_state >= UHCI_RH_RUNNING) {
                                dev_err(uhci_dev(uhci),
                                        "host controller halted, very bad!\n");
                                if (debug > 1 && errbuf) {
                                        /* Print the schedule for debugging */
                                        uhci_sprint_schedule(uhci, errbuf,
                                                ERRBUF_LEN - EXTRA_SPACE);
                                        lprintk(errbuf);
                                }
                                uhci_hc_died(uhci);
                                usb_hc_died(hcd);

                                /* Force a callback in case there are
                                 * pending unlinks */
                                mod_timer(&hcd->rh_timer, jiffies);
                        }
                }
        }

        if (status & USBSTS_RD) {
                spin_unlock(&uhci->lock);
                usb_hcd_poll_rh_status(hcd);
        } else {
                uhci_scan_schedule(uhci);
 done:
                spin_unlock(&uhci->lock);
        }

        return IRQ_HANDLED;
}

/*
 * Store the current frame number in uhci->frame_number if the controller
 * is running.  Expand from 11 bits (of which we use only 10) to a
 * full-sized integer.
 *
 * Like many other parts of the driver, this code relies on being polled
 * more than once per second as long as the controller is running.
 */
static void uhci_get_current_frame_number(struct uhci_hcd *uhci)
{
        if (!uhci->is_stopped) {
                unsigned delta;

                delta = (uhci_readw(uhci, USBFRNUM) - uhci->frame_number) &
                                (UHCI_NUMFRAMES - 1);
                uhci->frame_number += delta;
        }
}

/*
 * De-allocate all resources
 */
static void release_uhci(struct uhci_hcd *uhci)
{
        int i;


        spin_lock_irq(&uhci->lock);
        uhci->is_initialized = 0;
        spin_unlock_irq(&uhci->lock);

        debugfs_remove(uhci->dentry);

        for (i = 0; i < UHCI_NUM_SKELQH; i++)
                uhci_free_qh(uhci, uhci->skelqh[i]);

        uhci_free_td(uhci, uhci->term_td);

        dma_pool_destroy(uhci->qh_pool);

        dma_pool_destroy(uhci->td_pool);

        kfree(uhci->frame_cpu);

        dma_free_coherent(uhci_dev(uhci),
                        UHCI_NUMFRAMES * sizeof(*uhci->frame),
                        uhci->frame, uhci->frame_dma_handle);
}

/*
 * Allocate a frame list, and then setup the skeleton
 *
 * The hardware doesn't really know any difference
 * in the queues, but the order does matter for the
 * protocols higher up.  The order in which the queues
 * are encountered by the hardware is:
 *
 *  - All isochronous events are handled before any
 *    of the queues. We don't do that here, because
 *    we'll create the actual TD entries on demand.
 *  - The first queue is the high-period interrupt queue.
 *  - The second queue is the period-1 interrupt and async
 *    (low-speed control, full-speed control, then bulk) queue.
 *  - The third queue is the terminating bandwidth reclamation queue,
 *    which contains no members, loops back to itself, and is present
 *    only when FSBR is on and there are no full-speed control or bulk QHs.
 */
static int uhci_start(struct usb_hcd *hcd)
{
        struct uhci_hcd *uhci = hcd_to_uhci(hcd);
        int retval = -EBUSY;
        int i;
        struct dentry __maybe_unused *dentry;

        hcd->uses_new_polling = 1;
        /* Accept arbitrarily long scatter-gather lists */
        if (!(hcd->driver->flags & HCD_LOCAL_MEM))
                hcd->self.sg_tablesize = ~0;

        spin_lock_init(&uhci->lock);
        setup_timer(&uhci->fsbr_timer, uhci_fsbr_timeout,
                        (unsigned long) uhci);
        INIT_LIST_HEAD(&uhci->idle_qh_list);
        init_waitqueue_head(&uhci->waitqh);

#ifdef UHCI_DEBUG_OPS
        dentry = debugfs_create_file(hcd->self.bus_name,
                        S_IFREG|S_IRUGO|S_IWUSR, uhci_debugfs_root,
                        uhci, &uhci_debug_operations);
        if (!dentry) {
                dev_err(uhci_dev(uhci), "couldn't create uhci debugfs entry\n");
                return -ENOMEM;
        }
        uhci->dentry = dentry;
#endif

        uhci->frame = dma_alloc_coherent(uhci_dev(uhci),
                        UHCI_NUMFRAMES * sizeof(*uhci->frame),
                        &uhci->frame_dma_handle, 0);
        if (!uhci->frame) {
                dev_err(uhci_dev(uhci),
                        "unable to allocate consistent memory for frame list\n");
                goto err_alloc_frame;
        }
        memset(uhci->frame, 0, UHCI_NUMFRAMES * sizeof(*uhci->frame));

        uhci->frame_cpu = kcalloc(UHCI_NUMFRAMES, sizeof(*uhci->frame_cpu),
                        GFP_KERNEL);
        if (!uhci->frame_cpu) {
                dev_err(uhci_dev(uhci),
                        "unable to allocate memory for frame pointers\n");
                goto err_alloc_frame_cpu;
        }

        uhci->td_pool = dma_pool_create("uhci_td", uhci_dev(uhci),
                        sizeof(struct uhci_td), 16, 0);
        if (!uhci->td_pool) {
                dev_err(uhci_dev(uhci), "unable to create td dma_pool\n");
                goto err_create_td_pool;
        }

        uhci->qh_pool = dma_pool_create("uhci_qh", uhci_dev(uhci),
                        sizeof(struct uhci_qh), 16, 0);
        if (!uhci->qh_pool) {
                dev_err(uhci_dev(uhci), "unable to create qh dma_pool\n");
                goto err_create_qh_pool;
        }

        uhci->term_td = uhci_alloc_td(uhci);
        if (!uhci->term_td) {
                dev_err(uhci_dev(uhci), "unable to allocate terminating TD\n");
                goto err_alloc_term_td;
        }

        for (i = 0; i < UHCI_NUM_SKELQH; i++) {
                uhci->skelqh[i] = uhci_alloc_qh(uhci, NULL, NULL);
                if (!uhci->skelqh[i]) {
                        dev_err(uhci_dev(uhci), "unable to allocate QH\n");
                        goto err_alloc_skelqh;
                }
        }

        /*
         * 8 Interrupt queues; link all higher int queues to int1 = async
         */
        for (i = SKEL_ISO + 1; i < SKEL_ASYNC; ++i)
                uhci->skelqh[i]->link = LINK_TO_QH(uhci, uhci->skel_async_qh);
        uhci->skel_async_qh->link = UHCI_PTR_TERM(uhci);
        uhci->skel_term_qh->link = LINK_TO_QH(uhci, uhci->skel_term_qh);

        /* This dummy TD is to work around a bug in Intel PIIX controllers */
        uhci_fill_td(uhci, uhci->term_td, 0, uhci_explen(0) |
                        (0x7f << TD_TOKEN_DEVADDR_SHIFT) | USB_PID_IN, 0);
        uhci->term_td->link = UHCI_PTR_TERM(uhci);
        uhci->skel_async_qh->element = uhci->skel_term_qh->element =
                LINK_TO_TD(uhci, uhci->term_td);

        /*
         * Fill the frame list: make all entries point to the proper
         * interrupt queue.
         */
        for (i = 0; i < UHCI_NUMFRAMES; i++) {

                /* Only place we don't use the frame list routines */
                uhci->frame[i] = uhci_frame_skel_link(uhci, i);
        }

        /*
         * Some architectures require a full mb() to enforce completion of
         * the memory writes above before the I/O transfers in configure_hc().
         */
        mb();

        spin_lock_irq(&uhci->lock);
        configure_hc(uhci);
        uhci->is_initialized = 1;
        start_rh(uhci);
        spin_unlock_irq(&uhci->lock);
        return 0;

/*
 * error exits:
 */
err_alloc_skelqh:
        for (i = 0; i < UHCI_NUM_SKELQH; i++) {
                if (uhci->skelqh[i])
                        uhci_free_qh(uhci, uhci->skelqh[i]);
        }

        uhci_free_td(uhci, uhci->term_td);

err_alloc_term_td:
        dma_pool_destroy(uhci->qh_pool);

err_create_qh_pool:
        dma_pool_destroy(uhci->td_pool);

err_create_td_pool:
        kfree(uhci->frame_cpu);

err_alloc_frame_cpu:
        dma_free_coherent(uhci_dev(uhci),
                        UHCI_NUMFRAMES * sizeof(*uhci->frame),
                        uhci->frame, uhci->frame_dma_handle);

err_alloc_frame:
        debugfs_remove(uhci->dentry);

        return retval;
}

static void uhci_stop(struct usb_hcd *hcd)
{
        struct uhci_hcd *uhci = hcd_to_uhci(hcd);

        spin_lock_irq(&uhci->lock);
        if (HCD_HW_ACCESSIBLE(hcd) && !uhci->dead)
                uhci_hc_died(uhci);
        uhci_scan_schedule(uhci);
        spin_unlock_irq(&uhci->lock);
        synchronize_irq(hcd->irq);

        del_timer_sync(&uhci->fsbr_timer);
        release_uhci(uhci);
}

#ifdef CONFIG_PM
static int uhci_rh_suspend(struct usb_hcd *hcd)
{
        struct uhci_hcd *uhci = hcd_to_uhci(hcd);
        int rc = 0;

        spin_lock_irq(&uhci->lock);
        if (!HCD_HW_ACCESSIBLE(hcd))
                rc = -ESHUTDOWN;
        else if (uhci->dead)
                ;               /* Dead controllers tell no tales */

        /* Once the controller is stopped, port resumes that are already
         * in progress won't complete.  Hence if remote wakeup is enabled
         * for the root hub and any ports are in the middle of a resume or
         * remote wakeup, we must fail the suspend.
         */
        else if (hcd->self.root_hub->do_remote_wakeup &&
                        uhci->resuming_ports) {
                dev_dbg(uhci_dev(uhci),
                        "suspend failed because a port is resuming\n");
                rc = -EBUSY;
        } else
                suspend_rh(uhci, UHCI_RH_SUSPENDED);
        spin_unlock_irq(&uhci->lock);
        return rc;
}

static int uhci_rh_resume(struct usb_hcd *hcd)
{
        struct uhci_hcd *uhci = hcd_to_uhci(hcd);
        int rc = 0;

        spin_lock_irq(&uhci->lock);
        if (!HCD_HW_ACCESSIBLE(hcd))
                rc = -ESHUTDOWN;
        else if (!uhci->dead)
                wakeup_rh(uhci);
        spin_unlock_irq(&uhci->lock);
        return rc;
}

#endif

/* Wait until a particular device/endpoint's QH is idle, and free it */
static void uhci_hcd_endpoint_disable(struct usb_hcd *hcd,
                struct usb_host_endpoint *hep)
{
        struct uhci_hcd *uhci = hcd_to_uhci(hcd);
        struct uhci_qh *qh;

        spin_lock_irq(&uhci->lock);
        qh = (struct uhci_qh *) hep->hcpriv;
        if (qh == NULL)
                goto done;

        while (qh->state != QH_STATE_IDLE) {
                ++uhci->num_waiting;
                spin_unlock_irq(&uhci->lock);
                wait_event_interruptible(uhci->waitqh,
                                qh->state == QH_STATE_IDLE);
                spin_lock_irq(&uhci->lock);
                --uhci->num_waiting;
        }

        uhci_free_qh(uhci, qh);
done:
        spin_unlock_irq(&uhci->lock);
}

static int uhci_hcd_get_frame_number(struct usb_hcd *hcd)
{
        struct uhci_hcd *uhci = hcd_to_uhci(hcd);
        unsigned frame_number;
        unsigned delta;

        /* Minimize latency by avoiding the spinlock */
        frame_number = uhci->frame_number;
        barrier();
        delta = (uhci_readw(uhci, USBFRNUM) - frame_number) &
                        (UHCI_NUMFRAMES - 1);
        return frame_number + delta;
}

/* Determines number of ports on controller */
static int uhci_count_ports(struct usb_hcd *hcd)
{
        struct uhci_hcd *uhci = hcd_to_uhci(hcd);
        unsigned io_size = (unsigned) hcd->rsrc_len;
        int port;

        /* The UHCI spec says devices must have 2 ports, and goes on to say
         * they may have more but gives no way to determine how many there
         * are.  However according to the UHCI spec, Bit 7 of the port
         * status and control register is always set to 1.  So we try to
         * use this to our advantage.  Another common failure mode when
         * a nonexistent register is addressed is to return all ones, so
         * we test for that also.
         */
        for (port = 0; port < (io_size - USBPORTSC1) / 2; port++) {
                unsigned int portstatus;

                portstatus = uhci_readw(uhci, USBPORTSC1 + (port * 2));
                if (!(portstatus & 0x0080) || portstatus == 0xffff)
                        break;
        }
        if (debug)
                dev_info(uhci_dev(uhci), "detected %d ports\n", port);

        /* Anything greater than 7 is weird so we'll ignore it. */
        if (port > UHCI_RH_MAXCHILD) {
                dev_info(uhci_dev(uhci),
                        "port count misdetected? forcing to 2 ports\n");
                port = 2;
        }

        return port;
}

static const char hcd_name[] = "uhci_hcd";

#ifdef CONFIG_PCI
#include "uhci-pci.c"
#define PCI_DRIVER              uhci_pci_driver
#endif

#ifdef CONFIG_SPARC_LEON
#include "uhci-grlib.c"
#define PLATFORM_DRIVER         uhci_grlib_driver
#endif

#ifdef CONFIG_USB_UHCI_PLATFORM
#include "uhci-platform.c"
#define PLATFORM_DRIVER         uhci_platform_driver
#endif

#if !defined(PCI_DRIVER) && !defined(PLATFORM_DRIVER)
#error "missing bus glue for uhci-hcd"
#endif

static int __init uhci_hcd_init(void)
{
        int retval = -ENOMEM;

        if (usb_disabled())
                return -ENODEV;

        printk(KERN_INFO "uhci_hcd: " DRIVER_DESC "%s\n",
                        ignore_oc ? ", overcurrent ignored" : "");
        set_bit(USB_UHCI_LOADED, &usb_hcds_loaded);

#ifdef CONFIG_DYNAMIC_DEBUG
        errbuf = kmalloc(ERRBUF_LEN, GFP_KERNEL);
        if (!errbuf)
                goto errbuf_failed;
        uhci_debugfs_root = debugfs_create_dir("uhci", usb_debug_root);
        if (!uhci_debugfs_root)
                goto debug_failed;
#endif

        uhci_up_cachep = kmem_cache_create("uhci_urb_priv",
                sizeof(struct urb_priv), 0, 0, NULL);
        if (!uhci_up_cachep)
                goto up_failed;

#ifdef PLATFORM_DRIVER
        retval = platform_driver_register(&PLATFORM_DRIVER);
        if (retval < 0)
                goto clean0;
#endif

#ifdef PCI_DRIVER
        retval = pci_register_driver(&PCI_DRIVER);
        if (retval < 0)
                goto clean1;
#endif

        return 0;

#ifdef PCI_DRIVER
clean1:
#endif
#ifdef PLATFORM_DRIVER
        platform_driver_unregister(&PLATFORM_DRIVER);
clean0:
#endif
        kmem_cache_destroy(uhci_up_cachep);

up_failed:
#if defined(DEBUG) || defined(CONFIG_DYNAMIC_DEBUG)
        debugfs_remove(uhci_debugfs_root);

debug_failed:
        kfree(errbuf);

errbuf_failed:
#endif

        clear_bit(USB_UHCI_LOADED, &usb_hcds_loaded);
        return retval;
}

static void __exit uhci_hcd_cleanup(void) 
{
#ifdef PLATFORM_DRIVER
        platform_driver_unregister(&PLATFORM_DRIVER);
#endif
#ifdef PCI_DRIVER
        pci_unregister_driver(&PCI_DRIVER);
#endif
        kmem_cache_destroy(uhci_up_cachep);
        debugfs_remove(uhci_debugfs_root);
#ifdef CONFIG_DYNAMIC_DEBUG
        kfree(errbuf);
#endif
        clear_bit(USB_UHCI_LOADED, &usb_hcds_loaded);
}

module_init(uhci_hcd_init);
module_exit(uhci_hcd_cleanup);

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