[safe/jmp/linux-2.6] / drivers / usb / gadget / pxa2xx_udc.c

/*
 * linux/drivers/usb/gadget/pxa2xx_udc.c
 * Intel PXA25x and IXP4xx on-chip full speed USB device controllers
 *
 * Copyright (C) 2002 Intrinsyc, Inc. (Frank Becker)
 * Copyright (C) 2003 Robert Schwebel, Pengutronix
 * Copyright (C) 2003 Benedikt Spranger, Pengutronix
 * Copyright (C) 2003 David Brownell
 * Copyright (C) 2003 Joshua Wise
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

// #define      VERBOSE DBG_VERBOSE

#include <linux/device.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/ioport.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/timer.h>
#include <linux/list.h>
#include <linux/interrupt.h>
#include <linux/proc_fs.h>
#include <linux/mm.h>
#include <linux/platform_device.h>
#include <linux/dma-mapping.h>
#include <linux/irq.h>
#include <linux/clk.h>
#include <linux/err.h>

#include <asm/byteorder.h>
#include <asm/dma.h>
#include <asm/gpio.h>
#include <asm/io.h>
#include <asm/system.h>
#include <asm/mach-types.h>
#include <asm/unaligned.h>
#include <asm/hardware.h>

#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>

#include <asm/mach/udc_pxa2xx.h>


/*
 * This driver handles the USB Device Controller (UDC) in Intel's PXA 25x
 * series processors.  The UDC for the IXP 4xx series is very similar.
 * There are fifteen endpoints, in addition to ep0.
 *
 * Such controller drivers work with a gadget driver.  The gadget driver
 * returns descriptors, implements configuration and data protocols used
 * by the host to interact with this device, and allocates endpoints to
 * the different protocol interfaces.  The controller driver virtualizes
 * usb hardware so that the gadget drivers will be more portable.
 *
 * This UDC hardware wants to implement a bit too much USB protocol, so
 * it constrains the sorts of USB configuration change events that work.
 * The errata for these chips are misleading; some "fixed" bugs from
 * pxa250 a0/a1 b0/b1/b2 sure act like they're still there.
 *
 * Note that the UDC hardware supports DMA (except on IXP) but that's
 * not used here.  IN-DMA (to host) is simple enough, when the data is
 * suitably aligned (16 bytes) ... the network stack doesn't do that,
 * other software can.  OUT-DMA is buggy in most chip versions, as well
 * as poorly designed (data toggle not automatic).  So this driver won't
 * bother using DMA.  (Mostly-working IN-DMA support was available in
 * kernels before 2.6.23, but was never enabled or well tested.)
 */

#define DRIVER_VERSION  "30-June-2007"
#define DRIVER_DESC     "PXA 25x USB Device Controller driver"


static const char driver_name [] = "pxa2xx_udc";

static const char ep0name [] = "ep0";


#ifdef CONFIG_ARCH_IXP4XX

/* cpu-specific register addresses are compiled in to this code */
#ifdef CONFIG_ARCH_PXA
#error "Can't configure both IXP and PXA"
#endif

#endif

#include "pxa2xx_udc.h"


#ifdef  CONFIG_USB_PXA2XX_SMALL
#define SIZE_STR        " (small)"
#else
#define SIZE_STR        ""
#endif

/* ---------------------------------------------------------------------------
 *      endpoint related parts of the api to the usb controller hardware,
 *      used by gadget driver; and the inner talker-to-hardware core.
 * ---------------------------------------------------------------------------
 */

static void pxa2xx_ep_fifo_flush (struct usb_ep *ep);
static void nuke (struct pxa2xx_ep *, int status);

/* one GPIO should be used to detect VBUS from the host */
static int is_vbus_present(void)
{
        struct pxa2xx_udc_mach_info             *mach = the_controller->mach;

        if (mach->gpio_vbus)
                return gpio_get_value(mach->gpio_vbus);
        if (mach->udc_is_connected)
                return mach->udc_is_connected();
        return 1;
}

/* one GPIO should control a D+ pullup, so host sees this device (or not) */
static void pullup_off(void)
{
        struct pxa2xx_udc_mach_info             *mach = the_controller->mach;

        if (mach->gpio_pullup)
                gpio_set_value(mach->gpio_pullup, 0);
        else if (mach->udc_command)
                mach->udc_command(PXA2XX_UDC_CMD_DISCONNECT);
}

static void pullup_on(void)
{
        struct pxa2xx_udc_mach_info             *mach = the_controller->mach;

        if (mach->gpio_pullup)
                gpio_set_value(mach->gpio_pullup, 1);
        else if (mach->udc_command)
                mach->udc_command(PXA2XX_UDC_CMD_CONNECT);
}

static void pio_irq_enable(int bEndpointAddress)
{
        bEndpointAddress &= 0xf;
        if (bEndpointAddress < 8)
                UICR0 &= ~(1 << bEndpointAddress);
        else {
                bEndpointAddress -= 8;
                UICR1 &= ~(1 << bEndpointAddress);
        }
}

static void pio_irq_disable(int bEndpointAddress)
{
        bEndpointAddress &= 0xf;
        if (bEndpointAddress < 8)
                UICR0 |= 1 << bEndpointAddress;
        else {
                bEndpointAddress -= 8;
                UICR1 |= 1 << bEndpointAddress;
        }
}

/* The UDCCR reg contains mask and interrupt status bits,
 * so using '|=' isn't safe as it may ack an interrupt.
 */
#define UDCCR_MASK_BITS         (UDCCR_REM | UDCCR_SRM | UDCCR_UDE)

static inline void udc_set_mask_UDCCR(int mask)
{
        UDCCR = (UDCCR & UDCCR_MASK_BITS) | (mask & UDCCR_MASK_BITS);
}

static inline void udc_clear_mask_UDCCR(int mask)
{
        UDCCR = (UDCCR & UDCCR_MASK_BITS) & ~(mask & UDCCR_MASK_BITS);
}

static inline void udc_ack_int_UDCCR(int mask)
{
        /* udccr contains the bits we dont want to change */
        __u32 udccr = UDCCR & UDCCR_MASK_BITS;

        UDCCR = udccr | (mask & ~UDCCR_MASK_BITS);
}

/*
 * endpoint enable/disable
 *
 * we need to verify the descriptors used to enable endpoints.  since pxa2xx
 * endpoint configurations are fixed, and are pretty much always enabled,
 * there's not a lot to manage here.
 *
 * because pxa2xx can't selectively initialize bulk (or interrupt) endpoints,
 * (resetting endpoint halt and toggle), SET_INTERFACE is unusable except
 * for a single interface (with only the default altsetting) and for gadget
 * drivers that don't halt endpoints (not reset by set_interface).  that also
 * means that if you use ISO, you must violate the USB spec rule that all
 * iso endpoints must be in non-default altsettings.
 */
static int pxa2xx_ep_enable (struct usb_ep *_ep,
                const struct usb_endpoint_descriptor *desc)
{
        struct pxa2xx_ep        *ep;
        struct pxa2xx_udc       *dev;

        ep = container_of (_ep, struct pxa2xx_ep, ep);
        if (!_ep || !desc || ep->desc || _ep->name == ep0name
                        || desc->bDescriptorType != USB_DT_ENDPOINT
                        || ep->bEndpointAddress != desc->bEndpointAddress
                        || ep->fifo_size < le16_to_cpu
                                                (desc->wMaxPacketSize)) {
                DMSG("%s, bad ep or descriptor\n", __FUNCTION__);
                return -EINVAL;
        }

        /* xfer types must match, except that interrupt ~= bulk */
        if (ep->bmAttributes != desc->bmAttributes
                        && ep->bmAttributes != USB_ENDPOINT_XFER_BULK
                        && desc->bmAttributes != USB_ENDPOINT_XFER_INT) {
                DMSG("%s, %s type mismatch\n", __FUNCTION__, _ep->name);
                return -EINVAL;
        }

        /* hardware _could_ do smaller, but driver doesn't */
        if ((desc->bmAttributes == USB_ENDPOINT_XFER_BULK
                                && le16_to_cpu (desc->wMaxPacketSize)
                                                != BULK_FIFO_SIZE)
                        || !desc->wMaxPacketSize) {
                DMSG("%s, bad %s maxpacket\n", __FUNCTION__, _ep->name);
                return -ERANGE;
        }

        dev = ep->dev;
        if (!dev->driver || dev->gadget.speed == USB_SPEED_UNKNOWN) {
                DMSG("%s, bogus device state\n", __FUNCTION__);
                return -ESHUTDOWN;
        }

        ep->desc = desc;
        ep->stopped = 0;
        ep->pio_irqs = 0;
        ep->ep.maxpacket = le16_to_cpu (desc->wMaxPacketSize);

        /* flush fifo (mostly for OUT buffers) */
        pxa2xx_ep_fifo_flush (_ep);

        /* ... reset halt state too, if we could ... */

        DBG(DBG_VERBOSE, "enabled %s\n", _ep->name);
        return 0;
}

static int pxa2xx_ep_disable (struct usb_ep *_ep)
{
        struct pxa2xx_ep        *ep;
        unsigned long           flags;

        ep = container_of (_ep, struct pxa2xx_ep, ep);
        if (!_ep || !ep->desc) {
                DMSG("%s, %s not enabled\n", __FUNCTION__,
                        _ep ? ep->ep.name : NULL);
                return -EINVAL;
        }
        local_irq_save(flags);

        nuke (ep, -ESHUTDOWN);

        /* flush fifo (mostly for IN buffers) */
        pxa2xx_ep_fifo_flush (_ep);

        ep->desc = NULL;
        ep->stopped = 1;

        local_irq_restore(flags);
        DBG(DBG_VERBOSE, "%s disabled\n", _ep->name);
        return 0;
}

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

/* for the pxa2xx, these can just wrap kmalloc/kfree.  gadget drivers
 * must still pass correctly initialized endpoints, since other controller
 * drivers may care about how it's currently set up (dma issues etc).
 */

/*
 *      pxa2xx_ep_alloc_request - allocate a request data structure
 */
static struct usb_request *
pxa2xx_ep_alloc_request (struct usb_ep *_ep, gfp_t gfp_flags)
{
        struct pxa2xx_request *req;

        req = kzalloc(sizeof(*req), gfp_flags);
        if (!req)
                return NULL;

        INIT_LIST_HEAD (&req->queue);
        return &req->req;
}


/*
 *      pxa2xx_ep_free_request - deallocate a request data structure
 */
static void
pxa2xx_ep_free_request (struct usb_ep *_ep, struct usb_request *_req)
{
        struct pxa2xx_request   *req;

        req = container_of (_req, struct pxa2xx_request, req);
        WARN_ON (!list_empty (&req->queue));
        kfree(req);
}

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

/*
 *      done - retire a request; caller blocked irqs
 */
static void done(struct pxa2xx_ep *ep, struct pxa2xx_request *req, int status)
{
        unsigned                stopped = ep->stopped;

        list_del_init(&req->queue);

        if (likely (req->req.status == -EINPROGRESS))
                req->req.status = status;
        else
                status = req->req.status;

        if (status && status != -ESHUTDOWN)
                DBG(DBG_VERBOSE, "complete %s req %p stat %d len %u/%u\n",
                        ep->ep.name, &req->req, status,
                        req->req.actual, req->req.length);

        /* don't modify queue heads during completion callback */
        ep->stopped = 1;
        req->req.complete(&ep->ep, &req->req);
        ep->stopped = stopped;
}


static inline void ep0_idle (struct pxa2xx_udc *dev)
{
        dev->ep0state = EP0_IDLE;
}

static int
write_packet(volatile u32 *uddr, struct pxa2xx_request *req, unsigned max)
{
        u8              *buf;
        unsigned        length, count;

        buf = req->req.buf + req->req.actual;
        prefetch(buf);

        /* how big will this packet be? */
        length = min(req->req.length - req->req.actual, max);
        req->req.actual += length;

        count = length;
        while (likely(count--))
                *uddr = *buf++;

        return length;
}

/*
 * write to an IN endpoint fifo, as many packets as possible.
 * irqs will use this to write the rest later.
 * caller guarantees at least one packet buffer is ready (or a zlp).
 */
static int
write_fifo (struct pxa2xx_ep *ep, struct pxa2xx_request *req)
{
        unsigned                max;

        max = le16_to_cpu(ep->desc->wMaxPacketSize);
        do {
                unsigned        count;
                int             is_last, is_short;

                count = write_packet(ep->reg_uddr, req, max);

                /* last packet is usually short (or a zlp) */
                if (unlikely (count != max))
                        is_last = is_short = 1;
                else {
                        if (likely(req->req.length != req->req.actual)
                                        || req->req.zero)
                                is_last = 0;
                        else
                                is_last = 1;
                        /* interrupt/iso maxpacket may not fill the fifo */
                        is_short = unlikely (max < ep->fifo_size);
                }

                DBG(DBG_VERY_NOISY, "wrote %s %d bytes%s%s %d left %p\n",
                        ep->ep.name, count,
                        is_last ? "/L" : "", is_short ? "/S" : "",
                        req->req.length - req->req.actual, req);

                /* let loose that packet. maybe try writing another one,
                 * double buffering might work.  TSP, TPC, and TFS
                 * bit values are the same for all normal IN endpoints.
                 */
                *ep->reg_udccs = UDCCS_BI_TPC;
                if (is_short)
                        *ep->reg_udccs = UDCCS_BI_TSP;

                /* requests complete when all IN data is in the FIFO */
                if (is_last) {
                        done (ep, req, 0);
                        if (list_empty(&ep->queue))
                                pio_irq_disable (ep->bEndpointAddress);
                        return 1;
                }

                // TODO experiment: how robust can fifo mode tweaking be?
                // double buffering is off in the default fifo mode, which
                // prevents TFS from being set here.

        } while (*ep->reg_udccs & UDCCS_BI_TFS);
        return 0;
}

/* caller asserts req->pending (ep0 irq status nyet cleared); starts
 * ep0 data stage.  these chips want very simple state transitions.
 */
static inline
void ep0start(struct pxa2xx_udc *dev, u32 flags, const char *tag)
{
        UDCCS0 = flags|UDCCS0_SA|UDCCS0_OPR;
        USIR0 = USIR0_IR0;
        dev->req_pending = 0;
        DBG(DBG_VERY_NOISY, "%s %s, %02x/%02x\n",
                __FUNCTION__, tag, UDCCS0, flags);
}

static int
write_ep0_fifo (struct pxa2xx_ep *ep, struct pxa2xx_request *req)
{
        unsigned        count;
        int             is_short;

        count = write_packet(&UDDR0, req, EP0_FIFO_SIZE);
        ep->dev->stats.write.bytes += count;

        /* last packet "must be" short (or a zlp) */
        is_short = (count != EP0_FIFO_SIZE);

        DBG(DBG_VERY_NOISY, "ep0in %d bytes %d left %p\n", count,
                req->req.length - req->req.actual, req);

        if (unlikely (is_short)) {
                if (ep->dev->req_pending)
                        ep0start(ep->dev, UDCCS0_IPR, "short IN");
                else
                        UDCCS0 = UDCCS0_IPR;

                count = req->req.length;
                done (ep, req, 0);
                ep0_idle(ep->dev);
#ifndef CONFIG_ARCH_IXP4XX
#if 1
                /* This seems to get rid of lost status irqs in some cases:
                 * host responds quickly, or next request involves config
                 * change automagic, or should have been hidden, or ...
                 *
                 * FIXME get rid of all udelays possible...
                 */
                if (count >= EP0_FIFO_SIZE) {
                        count = 100;
                        do {
                                if ((UDCCS0 & UDCCS0_OPR) != 0) {
                                        /* clear OPR, generate ack */
                                        UDCCS0 = UDCCS0_OPR;
                                        break;
                                }
                                count--;
                                udelay(1);
                        } while (count);
                }
#endif
#endif
        } else if (ep->dev->req_pending)
                ep0start(ep->dev, 0, "IN");
        return is_short;
}


/*
 * read_fifo -  unload packet(s) from the fifo we use for usb OUT
 * transfers and put them into the request.  caller should have made
 * sure there's at least one packet ready.
 *
 * returns true if the request completed because of short packet or the
 * request buffer having filled (and maybe overran till end-of-packet).
 */
static int
read_fifo (struct pxa2xx_ep *ep, struct pxa2xx_request *req)
{
        for (;;) {
                u32             udccs;
                u8              *buf;
                unsigned        bufferspace, count, is_short;

                /* make sure there's a packet in the FIFO.
                 * UDCCS_{BO,IO}_RPC are all the same bit value.
                 * UDCCS_{BO,IO}_RNE are all the same bit value.
                 */
                udccs = *ep->reg_udccs;
                if (unlikely ((udccs & UDCCS_BO_RPC) == 0))
                        break;
                buf = req->req.buf + req->req.actual;
                prefetchw(buf);
                bufferspace = req->req.length - req->req.actual;

                /* read all bytes from this packet */
                if (likely (udccs & UDCCS_BO_RNE)) {
                        count = 1 + (0x0ff & *ep->reg_ubcr);
                        req->req.actual += min (count, bufferspace);
                } else /* zlp */
                        count = 0;
                is_short = (count < ep->ep.maxpacket);
                DBG(DBG_VERY_NOISY, "read %s %02x, %d bytes%s req %p %d/%d\n",
                        ep->ep.name, udccs, count,
                        is_short ? "/S" : "",
                        req, req->req.actual, req->req.length);
                while (likely (count-- != 0)) {
                        u8      byte = (u8) *ep->reg_uddr;

                        if (unlikely (bufferspace == 0)) {
                                /* this happens when the driver's buffer
                                 * is smaller than what the host sent.
                                 * discard the extra data.
                                 */
                                if (req->req.status != -EOVERFLOW)
                                        DMSG("%s overflow %d\n",
                                                ep->ep.name, count);
                                req->req.status = -EOVERFLOW;
                        } else {
                                *buf++ = byte;
                                bufferspace--;
                        }
                }
                *ep->reg_udccs =  UDCCS_BO_RPC;
                /* RPC/RSP/RNE could now reflect the other packet buffer */

                /* iso is one request per packet */
                if (ep->bmAttributes == USB_ENDPOINT_XFER_ISOC) {
                        if (udccs & UDCCS_IO_ROF)
                                req->req.status = -EHOSTUNREACH;
                        /* more like "is_done" */
                        is_short = 1;
                }

                /* completion */
                if (is_short || req->req.actual == req->req.length) {
                        done (ep, req, 0);
                        if (list_empty(&ep->queue))
                                pio_irq_disable (ep->bEndpointAddress);
                        return 1;
                }

                /* finished that packet.  the next one may be waiting... */
        }
        return 0;
}

/*
 * special ep0 version of the above.  no UBCR0 or double buffering; status
 * handshaking is magic.  most device protocols don't need control-OUT.
 * CDC vendor commands (and RNDIS), mass storage CB/CBI, and some other
 * protocols do use them.
 */
static int
read_ep0_fifo (struct pxa2xx_ep *ep, struct pxa2xx_request *req)
{
        u8              *buf, byte;
        unsigned        bufferspace;

        buf = req->req.buf + req->req.actual;
        bufferspace = req->req.length - req->req.actual;

        while (UDCCS0 & UDCCS0_RNE) {
                byte = (u8) UDDR0;

                if (unlikely (bufferspace == 0)) {
                        /* this happens when the driver's buffer
                         * is smaller than what the host sent.
                         * discard the extra data.
                         */
                        if (req->req.status != -EOVERFLOW)
                                DMSG("%s overflow\n", ep->ep.name);
                        req->req.status = -EOVERFLOW;
                } else {
                        *buf++ = byte;
                        req->req.actual++;
                        bufferspace--;
                }
        }

        UDCCS0 = UDCCS0_OPR | UDCCS0_IPR;

        /* completion */
        if (req->req.actual >= req->req.length)
                return 1;

        /* finished that packet.  the next one may be waiting... */
        return 0;
}

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

static int
pxa2xx_ep_queue(struct usb_ep *_ep, struct usb_request *_req, gfp_t gfp_flags)
{
        struct pxa2xx_request   *req;
        struct pxa2xx_ep        *ep;
        struct pxa2xx_udc       *dev;
        unsigned long           flags;

        req = container_of(_req, struct pxa2xx_request, req);
        if (unlikely (!_req || !_req->complete || !_req->buf
                        || !list_empty(&req->queue))) {
                DMSG("%s, bad params\n", __FUNCTION__);
                return -EINVAL;
        }

        ep = container_of(_ep, struct pxa2xx_ep, ep);
        if (unlikely (!_ep || (!ep->desc && ep->ep.name != ep0name))) {
                DMSG("%s, bad ep\n", __FUNCTION__);
                return -EINVAL;
        }

        dev = ep->dev;
        if (unlikely (!dev->driver
                        || dev->gadget.speed == USB_SPEED_UNKNOWN)) {
                DMSG("%s, bogus device state\n", __FUNCTION__);
                return -ESHUTDOWN;
        }

        /* iso is always one packet per request, that's the only way
         * we can report per-packet status.  that also helps with dma.
         */
        if (unlikely (ep->bmAttributes == USB_ENDPOINT_XFER_ISOC
                        && req->req.length > le16_to_cpu
                                                (ep->desc->wMaxPacketSize)))
                return -EMSGSIZE;

        DBG(DBG_NOISY, "%s queue req %p, len %d buf %p\n",
                _ep->name, _req, _req->length, _req->buf);

        local_irq_save(flags);

        _req->status = -EINPROGRESS;
        _req->actual = 0;

        /* kickstart this i/o queue? */
        if (list_empty(&ep->queue) && !ep->stopped) {
                if (ep->desc == 0 /* ep0 */) {
                        unsigned        length = _req->length;

                        switch (dev->ep0state) {
                        case EP0_IN_DATA_PHASE:
                                dev->stats.write.ops++;
                                if (write_ep0_fifo(ep, req))
                                        req = NULL;
                                break;

                        case EP0_OUT_DATA_PHASE:
                                dev->stats.read.ops++;
                                /* messy ... */
                                if (dev->req_config) {
                                        DBG(DBG_VERBOSE, "ep0 config ack%s\n",
                                                dev->has_cfr ?  "" : " raced");
                                        if (dev->has_cfr)
                                                UDCCFR = UDCCFR_AREN|UDCCFR_ACM
                                                        |UDCCFR_MB1;
                                        done(ep, req, 0);
                                        dev->ep0state = EP0_END_XFER;
                                        local_irq_restore (flags);
                                        return 0;
                                }
                                if (dev->req_pending)
                                        ep0start(dev, UDCCS0_IPR, "OUT");
                                if (length == 0 || ((UDCCS0 & UDCCS0_RNE) != 0
                                                && read_ep0_fifo(ep, req))) {
                                        ep0_idle(dev);
                                        done(ep, req, 0);
                                        req = NULL;
                                }
                                break;

                        default:
                                DMSG("ep0 i/o, odd state %d\n", dev->ep0state);
                                local_irq_restore (flags);
                                return -EL2HLT;
                        }
                /* can the FIFO can satisfy the request immediately? */
                } else if ((ep->bEndpointAddress & USB_DIR_IN) != 0) {
                        if ((*ep->reg_udccs & UDCCS_BI_TFS) != 0
                                        && write_fifo(ep, req))
                                req = NULL;
                } else if ((*ep->reg_udccs & UDCCS_BO_RFS) != 0
                                && read_fifo(ep, req)) {
                        req = NULL;
                }

                if (likely (req && ep->desc))
                        pio_irq_enable(ep->bEndpointAddress);
        }

        /* pio or dma irq handler advances the queue. */
        if (likely (req != 0))
                list_add_tail(&req->queue, &ep->queue);
        local_irq_restore(flags);

        return 0;
}


/*
 *      nuke - dequeue ALL requests
 */
static void nuke(struct pxa2xx_ep *ep, int status)
{
        struct pxa2xx_request *req;

        /* called with irqs blocked */
        while (!list_empty(&ep->queue)) {
                req = list_entry(ep->queue.next,
                                struct pxa2xx_request,
                                queue);
                done(ep, req, status);
        }
        if (ep->desc)
                pio_irq_disable (ep->bEndpointAddress);
}


/* dequeue JUST ONE request */
static int pxa2xx_ep_dequeue(struct usb_ep *_ep, struct usb_request *_req)
{
        struct pxa2xx_ep        *ep;
        struct pxa2xx_request   *req;
        unsigned long           flags;

        ep = container_of(_ep, struct pxa2xx_ep, ep);
        if (!_ep || ep->ep.name == ep0name)
                return -EINVAL;

        local_irq_save(flags);

        /* make sure it's actually queued on this endpoint */
        list_for_each_entry (req, &ep->queue, queue) {
                if (&req->req == _req)
                        break;
        }
        if (&req->req != _req) {
                local_irq_restore(flags);
                return -EINVAL;
        }

        done(ep, req, -ECONNRESET);

        local_irq_restore(flags);
        return 0;
}

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

static int pxa2xx_ep_set_halt(struct usb_ep *_ep, int value)
{
        struct pxa2xx_ep        *ep;
        unsigned long           flags;

        ep = container_of(_ep, struct pxa2xx_ep, ep);
        if (unlikely (!_ep
                        || (!ep->desc && ep->ep.name != ep0name))
                        || ep->bmAttributes == USB_ENDPOINT_XFER_ISOC) {
                DMSG("%s, bad ep\n", __FUNCTION__);
                return -EINVAL;
        }
        if (value == 0) {
                /* this path (reset toggle+halt) is needed to implement
                 * SET_INTERFACE on normal hardware.  but it can't be
                 * done from software on the PXA UDC, and the hardware
                 * forgets to do it as part of SET_INTERFACE automagic.
                 */
                DMSG("only host can clear %s halt\n", _ep->name);
                return -EROFS;
        }

        local_irq_save(flags);

        if ((ep->bEndpointAddress & USB_DIR_IN) != 0
                        && ((*ep->reg_udccs & UDCCS_BI_TFS) == 0
                           || !list_empty(&ep->queue))) {
                local_irq_restore(flags);
                return -EAGAIN;
        }

        /* FST bit is the same for control, bulk in, bulk out, interrupt in */
        *ep->reg_udccs = UDCCS_BI_FST|UDCCS_BI_FTF;

        /* ep0 needs special care */
        if (!ep->desc) {
                start_watchdog(ep->dev);
                ep->dev->req_pending = 0;
                ep->dev->ep0state = EP0_STALL;

        /* and bulk/intr endpoints like dropping stalls too */
        } else {
                unsigned i;
                for (i = 0; i < 1000; i += 20) {
                        if (*ep->reg_udccs & UDCCS_BI_SST)
                                break;
                        udelay(20);
                }
        }
        local_irq_restore(flags);

        DBG(DBG_VERBOSE, "%s halt\n", _ep->name);
        return 0;
}

static int pxa2xx_ep_fifo_status(struct usb_ep *_ep)
{
        struct pxa2xx_ep        *ep;

        ep = container_of(_ep, struct pxa2xx_ep, ep);
        if (!_ep) {
                DMSG("%s, bad ep\n", __FUNCTION__);
                return -ENODEV;
        }
        /* pxa can't report unclaimed bytes from IN fifos */
        if ((ep->bEndpointAddress & USB_DIR_IN) != 0)
                return -EOPNOTSUPP;
        if (ep->dev->gadget.speed == USB_SPEED_UNKNOWN
                        || (*ep->reg_udccs & UDCCS_BO_RFS) == 0)
                return 0;
        else
                return (*ep->reg_ubcr & 0xfff) + 1;
}

static void pxa2xx_ep_fifo_flush(struct usb_ep *_ep)
{
        struct pxa2xx_ep        *ep;

        ep = container_of(_ep, struct pxa2xx_ep, ep);
        if (!_ep || ep->ep.name == ep0name || !list_empty(&ep->queue)) {
                DMSG("%s, bad ep\n", __FUNCTION__);
                return;
        }

        /* toggle and halt bits stay unchanged */

        /* for OUT, just read and discard the FIFO contents. */
        if ((ep->bEndpointAddress & USB_DIR_IN) == 0) {
                while (((*ep->reg_udccs) & UDCCS_BO_RNE) != 0)
                        (void) *ep->reg_uddr;
                return;
        }

        /* most IN status is the same, but ISO can't stall */
        *ep->reg_udccs = UDCCS_BI_TPC|UDCCS_BI_FTF|UDCCS_BI_TUR
                | (ep->bmAttributes == USB_ENDPOINT_XFER_ISOC)
                        ? 0 : UDCCS_BI_SST;
}


static struct usb_ep_ops pxa2xx_ep_ops = {
        .enable         = pxa2xx_ep_enable,
        .disable        = pxa2xx_ep_disable,

        .alloc_request  = pxa2xx_ep_alloc_request,
        .free_request   = pxa2xx_ep_free_request,

        .queue          = pxa2xx_ep_queue,
        .dequeue        = pxa2xx_ep_dequeue,

        .set_halt       = pxa2xx_ep_set_halt,
        .fifo_status    = pxa2xx_ep_fifo_status,
        .fifo_flush     = pxa2xx_ep_fifo_flush,
};


/* ---------------------------------------------------------------------------
 *      device-scoped parts of the api to the usb controller hardware
 * ---------------------------------------------------------------------------
 */

static int pxa2xx_udc_get_frame(struct usb_gadget *_gadget)
{
        return ((UFNRH & 0x07) << 8) | (UFNRL & 0xff);
}

static int pxa2xx_udc_wakeup(struct usb_gadget *_gadget)
{
        /* host may not have enabled remote wakeup */
        if ((UDCCS0 & UDCCS0_DRWF) == 0)
                return -EHOSTUNREACH;
        udc_set_mask_UDCCR(UDCCR_RSM);
        return 0;
}

static void stop_activity(struct pxa2xx_udc *, struct usb_gadget_driver *);
static void udc_enable (struct pxa2xx_udc *);
static void udc_disable(struct pxa2xx_udc *);

/* We disable the UDC -- and its 48 MHz clock -- whenever it's not
 * in active use.
 */
static int pullup(struct pxa2xx_udc *udc, int is_active)
{
        is_active = is_active && udc->vbus && udc->pullup;
        DMSG("%s\n", is_active ? "active" : "inactive");
        if (is_active)
                udc_enable(udc);
        else {
                if (udc->gadget.speed != USB_SPEED_UNKNOWN) {
                        DMSG("disconnect %s\n", udc->driver
                                ? udc->driver->driver.name
                                : "(no driver)");
                        stop_activity(udc, udc->driver);
                }
                udc_disable(udc);
        }
        return 0;
}

/* VBUS reporting logically comes from a transceiver */
static int pxa2xx_udc_vbus_session(struct usb_gadget *_gadget, int is_active)
{
        struct pxa2xx_udc       *udc;

        udc = container_of(_gadget, struct pxa2xx_udc, gadget);
        udc->vbus = is_active = (is_active != 0);
        DMSG("vbus %s\n", is_active ? "supplied" : "inactive");
        pullup(udc, is_active);
        return 0;
}

/* drivers may have software control over D+ pullup */
static int pxa2xx_udc_pullup(struct usb_gadget *_gadget, int is_active)
{
        struct pxa2xx_udc       *udc;

        udc = container_of(_gadget, struct pxa2xx_udc, gadget);

        /* not all boards support pullup control */
        if (!udc->mach->gpio_pullup && !udc->mach->udc_command)
                return -EOPNOTSUPP;

        is_active = (is_active != 0);
        udc->pullup = is_active;
        pullup(udc, is_active);
        return 0;
}

static const struct usb_gadget_ops pxa2xx_udc_ops = {
        .get_frame      = pxa2xx_udc_get_frame,
        .wakeup         = pxa2xx_udc_wakeup,
        .vbus_session   = pxa2xx_udc_vbus_session,
        .pullup         = pxa2xx_udc_pullup,

        // .vbus_draw ... boards may consume current from VBUS, up to
        // 100-500mA based on config.  the 500uA suspend ceiling means
        // that exclusively vbus-powered PXA designs violate USB specs.
};

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

#ifdef CONFIG_USB_GADGET_DEBUG_FILES

static const char proc_node_name [] = "driver/udc";

static int
udc_proc_read(char *page, char **start, off_t off, int count,
                int *eof, void *_dev)
{
        char                    *buf = page;
        struct pxa2xx_udc       *dev = _dev;
        char                    *next = buf;
        unsigned                size = count;
        unsigned long           flags;
        int                     i, t;
        u32                     tmp;

        if (off != 0)
                return 0;

        local_irq_save(flags);

        /* basic device status */
        t = scnprintf(next, size, DRIVER_DESC "\n"
                "%s version: %s\nGadget driver: %s\nHost %s\n\n",
                driver_name, DRIVER_VERSION SIZE_STR "(pio)",
                dev->driver ? dev->driver->driver.name : "(none)",
                is_vbus_present() ? "full speed" : "disconnected");
        size -= t;
        next += t;

        /* registers for device and ep0 */
        t = scnprintf(next, size,
                "uicr %02X.%02X, usir %02X.%02x, ufnr %02X.%02X\n",
                UICR1, UICR0, USIR1, USIR0, UFNRH, UFNRL);
        size -= t;
        next += t;

        tmp = UDCCR;
        t = scnprintf(next, size,
                "udccr %02X =%s%s%s%s%s%s%s%s\n", tmp,
                (tmp & UDCCR_REM) ? " rem" : "",
                (tmp & UDCCR_RSTIR) ? " rstir" : "",
                (tmp & UDCCR_SRM) ? " srm" : "",
                (tmp & UDCCR_SUSIR) ? " susir" : "",
                (tmp & UDCCR_RESIR) ? " resir" : "",
                (tmp & UDCCR_RSM) ? " rsm" : "",
                (tmp & UDCCR_UDA) ? " uda" : "",
                (tmp & UDCCR_UDE) ? " ude" : "");
        size -= t;
        next += t;

        tmp = UDCCS0;
        t = scnprintf(next, size,
                "udccs0 %02X =%s%s%s%s%s%s%s%s\n", tmp,
                (tmp & UDCCS0_SA) ? " sa" : "",
                (tmp & UDCCS0_RNE) ? " rne" : "",
                (tmp & UDCCS0_FST) ? " fst" : "",
                (tmp & UDCCS0_SST) ? " sst" : "",
                (tmp & UDCCS0_DRWF) ? " dwrf" : "",
                (tmp & UDCCS0_FTF) ? " ftf" : "",
                (tmp & UDCCS0_IPR) ? " ipr" : "",
                (tmp & UDCCS0_OPR) ? " opr" : "");
        size -= t;
        next += t;

        if (dev->has_cfr) {
                tmp = UDCCFR;
                t = scnprintf(next, size,
                        "udccfr %02X =%s%s\n", tmp,
                        (tmp & UDCCFR_AREN) ? " aren" : "",
                        (tmp & UDCCFR_ACM) ? " acm" : "");
                size -= t;
                next += t;
        }

        if (!is_vbus_present() || !dev->driver)
                goto done;

        t = scnprintf(next, size, "ep0 IN %lu/%lu, OUT %lu/%lu\nirqs %lu\n\n",
                dev->stats.write.bytes, dev->stats.write.ops,
                dev->stats.read.bytes, dev->stats.read.ops,
                dev->stats.irqs);
        size -= t;
        next += t;

        /* dump endpoint queues */
        for (i = 0; i < PXA_UDC_NUM_ENDPOINTS; i++) {
                struct pxa2xx_ep        *ep = &dev->ep [i];
                struct pxa2xx_request   *req;

                if (i != 0) {
                        const struct usb_endpoint_descriptor    *d;

                        d = ep->desc;
                        if (!d)
                                continue;
                        tmp = *dev->ep [i].reg_udccs;
                        t = scnprintf(next, size,
                                "%s max %d %s udccs %02x irqs %lu\n",
                                ep->ep.name, le16_to_cpu (d->wMaxPacketSize),
                                "pio", tmp, ep->pio_irqs);
                        /* TODO translate all five groups of udccs bits! */

                } else /* ep0 should only have one transfer queued */
                        t = scnprintf(next, size, "ep0 max 16 pio irqs %lu\n",
                                ep->pio_irqs);
                if (t <= 0 || t > size)
                        goto done;
                size -= t;
                next += t;

                if (list_empty(&ep->queue)) {
                        t = scnprintf(next, size, "\t(nothing queued)\n");
                        if (t <= 0 || t > size)
                                goto done;
                        size -= t;
                        next += t;
                        continue;
                }
                list_for_each_entry(req, &ep->queue, queue) {
                        t = scnprintf(next, size,
                                        "\treq %p len %d/%d buf %p\n",
                                        &req->req, req->req.actual,
                                        req->req.length, req->req.buf);
                        if (t <= 0 || t > size)
                                goto done;
                        size -= t;
                        next += t;
                }
        }

done:
        local_irq_restore(flags);
        *eof = 1;
        return count - size;
}

#define create_proc_files() \
        create_proc_read_entry(proc_node_name, 0, NULL, udc_proc_read, dev)
#define remove_proc_files() \
        remove_proc_entry(proc_node_name, NULL)

#else   /* !CONFIG_USB_GADGET_DEBUG_FILES */

#define create_proc_files() do {} while (0)
#define remove_proc_files() do {} while (0)

#endif  /* CONFIG_USB_GADGET_DEBUG_FILES */

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

/*
 *      udc_disable - disable USB device controller
 */
static void udc_disable(struct pxa2xx_udc *dev)
{
        /* block all irqs */
        udc_set_mask_UDCCR(UDCCR_SRM|UDCCR_REM);
        UICR0 = UICR1 = 0xff;
        UFNRH = UFNRH_SIM;

        /* if hardware supports it, disconnect from usb */
        pullup_off();

        udc_clear_mask_UDCCR(UDCCR_UDE);

#ifdef  CONFIG_ARCH_PXA
        /* Disable clock for USB device */
        clk_disable(dev->clk);
#endif

        ep0_idle (dev);
        dev->gadget.speed = USB_SPEED_UNKNOWN;
}


/*
 *      udc_reinit - initialize software state
 */
static void udc_reinit(struct pxa2xx_udc *dev)
{
        u32     i;

        /* device/ep0 records init */
        INIT_LIST_HEAD (&dev->gadget.ep_list);
        INIT_LIST_HEAD (&dev->gadget.ep0->ep_list);
        dev->ep0state = EP0_IDLE;

        /* basic endpoint records init */
        for (i = 0; i < PXA_UDC_NUM_ENDPOINTS; i++) {
                struct pxa2xx_ep *ep = &dev->ep[i];

                if (i != 0)
                        list_add_tail (&ep->ep.ep_list, &dev->gadget.ep_list);

                ep->desc = NULL;
                ep->stopped = 0;
                INIT_LIST_HEAD (&ep->queue);
                ep->pio_irqs = 0;
        }

        /* the rest was statically initialized, and is read-only */
}

/* until it's enabled, this UDC should be completely invisible
 * to any USB host.
 */
static void udc_enable (struct pxa2xx_udc *dev)
{
        udc_clear_mask_UDCCR(UDCCR_UDE);

#ifdef  CONFIG_ARCH_PXA
        /* Enable clock for USB device */
        clk_enable(dev->clk);
#endif

        /* try to clear these bits before we enable the udc */
        udc_ack_int_UDCCR(UDCCR_SUSIR|/*UDCCR_RSTIR|*/UDCCR_RESIR);

        ep0_idle(dev);
        dev->gadget.speed = USB_SPEED_UNKNOWN;
        dev->stats.irqs = 0;

        /*
         * sequence taken from chapter 12.5.10, PXA250 AppProcDevManual:
         * - enable UDC
         * - if RESET is already in progress, ack interrupt
         * - unmask reset interrupt
         */
        udc_set_mask_UDCCR(UDCCR_UDE);
        if (!(UDCCR & UDCCR_UDA))
                udc_ack_int_UDCCR(UDCCR_RSTIR);

        if (dev->has_cfr /* UDC_RES2 is defined */) {
                /* pxa255 (a0+) can avoid a set_config race that could
                 * prevent gadget drivers from configuring correctly
                 */
                UDCCFR = UDCCFR_ACM | UDCCFR_MB1;
        } else {
                /* "USB test mode" for pxa250 errata 40-42 (stepping a0, a1)
                 * which could result in missing packets and interrupts.
                 * supposedly one bit per endpoint, controlling whether it
                 * double buffers or not; ACM/AREN bits fit into the holes.
                 * zero bits (like USIR0_IRx) disable double buffering.
                 */
                UDC_RES1 = 0x00;
                UDC_RES2 = 0x00;
        }

        /* enable suspend/resume and reset irqs */
        udc_clear_mask_UDCCR(UDCCR_SRM | UDCCR_REM);

        /* enable ep0 irqs */
        UICR0 &= ~UICR0_IM0;

        /* if hardware supports it, pullup D+ and wait for reset */
        pullup_on();
}


/* when a driver is successfully registered, it will receive
 * control requests including set_configuration(), which enables
 * non-control requests.  then usb traffic follows until a
 * disconnect is reported.  then a host may connect again, or
 * the driver might get unbound.
 */
int usb_gadget_register_driver(struct usb_gadget_driver *driver)
{
        struct pxa2xx_udc       *dev = the_controller;
        int                     retval;

        if (!driver
                        || driver->speed < USB_SPEED_FULL
                        || !driver->bind
                        || !driver->disconnect
                        || !driver->setup)
                return -EINVAL;
        if (!dev)
                return -ENODEV;
        if (dev->driver)
                return -EBUSY;

        /* first hook up the driver ... */
        dev->driver = driver;
        dev->gadget.dev.driver = &driver->driver;
        dev->pullup = 1;

        retval = device_add (&dev->gadget.dev);
        if (retval) {
fail:
                dev->driver = NULL;
                dev->gadget.dev.driver = NULL;
                return retval;
        }
        retval = driver->bind(&dev->gadget);
        if (retval) {
                DMSG("bind to driver %s --> error %d\n",
                                driver->driver.name, retval);
                device_del (&dev->gadget.dev);
                goto fail;
        }

        /* ... then enable host detection and ep0; and we're ready
         * for set_configuration as well as eventual disconnect.
         */
        DMSG("registered gadget driver '%s'\n", driver->driver.name);
        pullup(dev, 1);
        dump_state(dev);
        return 0;
}
EXPORT_SYMBOL(usb_gadget_register_driver);

static void
stop_activity(struct pxa2xx_udc *dev, struct usb_gadget_driver *driver)
{
        int i;

        /* don't disconnect drivers more than once */
        if (dev->gadget.speed == USB_SPEED_UNKNOWN)
                driver = NULL;
        dev->gadget.speed = USB_SPEED_UNKNOWN;

        /* prevent new request submissions, kill any outstanding requests  */
        for (i = 0; i < PXA_UDC_NUM_ENDPOINTS; i++) {
                struct pxa2xx_ep *ep = &dev->ep[i];

                ep->stopped = 1;
                nuke(ep, -ESHUTDOWN);
        }
        del_timer_sync(&dev->timer);

        /* report disconnect; the driver is already quiesced */
        if (driver)
                driver->disconnect(&dev->gadget);

        /* re-init driver-visible data structures */
        udc_reinit(dev);
}

int usb_gadget_unregister_driver(struct usb_gadget_driver *driver)
{
        struct pxa2xx_udc       *dev = the_controller;

        if (!dev)
                return -ENODEV;
        if (!driver || driver != dev->driver || !driver->unbind)
                return -EINVAL;

        local_irq_disable();
        pullup(dev, 0);
        stop_activity(dev, driver);
        local_irq_enable();

        driver->unbind(&dev->gadget);
        dev->gadget.dev.driver = NULL;
        dev->driver = NULL;

        device_del (&dev->gadget.dev);

        DMSG("unregistered gadget driver '%s'\n", driver->driver.name);
        dump_state(dev);
        return 0;
}
EXPORT_SYMBOL(usb_gadget_unregister_driver);


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

#ifdef CONFIG_ARCH_LUBBOCK

/* Lubbock has separate connect and disconnect irqs.  More typical designs
 * use one GPIO as the VBUS IRQ, and another to control the D+ pullup.
 */

static irqreturn_t
lubbock_vbus_irq(int irq, void *_dev)
{
        struct pxa2xx_udc       *dev = _dev;
        int                     vbus;

        dev->stats.irqs++;
        switch (irq) {
        case LUBBOCK_USB_IRQ:
                vbus = 1;
                disable_irq(LUBBOCK_USB_IRQ);
                enable_irq(LUBBOCK_USB_DISC_IRQ);
                break;
        case LUBBOCK_USB_DISC_IRQ:
                vbus = 0;
                disable_irq(LUBBOCK_USB_DISC_IRQ);
                enable_irq(LUBBOCK_USB_IRQ);
                break;
        default:
                return IRQ_NONE;
        }

        pxa2xx_udc_vbus_session(&dev->gadget, vbus);
        return IRQ_HANDLED;
}

#endif

static irqreturn_t udc_vbus_irq(int irq, void *_dev)
{
        struct pxa2xx_udc       *dev = _dev;
        int                     vbus = gpio_get_value(dev->mach->gpio_vbus);

        pxa2xx_udc_vbus_session(&dev->gadget, vbus);
        return IRQ_HANDLED;
}


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

static inline void clear_ep_state (struct pxa2xx_udc *dev)
{
        unsigned i;

        /* hardware SET_{CONFIGURATION,INTERFACE} automagic resets endpoint
         * fifos, and pending transactions mustn't be continued in any case.
         */
        for (i = 1; i < PXA_UDC_NUM_ENDPOINTS; i++)
                nuke(&dev->ep[i], -ECONNABORTED);
}

static void udc_watchdog(unsigned long _dev)
{
        struct pxa2xx_udc       *dev = (void *)_dev;

        local_irq_disable();
        if (dev->ep0state == EP0_STALL
                        && (UDCCS0 & UDCCS0_FST) == 0
                        && (UDCCS0 & UDCCS0_SST) == 0) {
                UDCCS0 = UDCCS0_FST|UDCCS0_FTF;
                DBG(DBG_VERBOSE, "ep0 re-stall\n");
                start_watchdog(dev);
        }
        local_irq_enable();
}

static void handle_ep0 (struct pxa2xx_udc *dev)
{
        u32                     udccs0 = UDCCS0;
        struct pxa2xx_ep        *ep = &dev->ep [0];
        struct pxa2xx_request   *req;
        union {
                struct usb_ctrlrequest  r;
                u8                      raw [8];
                u32                     word [2];
        } u;

        if (list_empty(&ep->queue))
                req = NULL;
        else
                req = list_entry(ep->queue.next, struct pxa2xx_request, queue);

        /* clear stall status */
        if (udccs0 & UDCCS0_SST) {
                nuke(ep, -EPIPE);
                UDCCS0 = UDCCS0_SST;
                del_timer(&dev->timer);
                ep0_idle(dev);
        }

        /* previous request unfinished?  non-error iff back-to-back ... */
        if ((udccs0 & UDCCS0_SA) != 0 && dev->ep0state != EP0_IDLE) {
                nuke(ep, 0);
                del_timer(&dev->timer);
                ep0_idle(dev);
        }

        switch (dev->ep0state) {
        case EP0_IDLE:
                /* late-breaking status? */
                udccs0 = UDCCS0;

                /* start control request? */
                if (likely((udccs0 & (UDCCS0_OPR|UDCCS0_SA|UDCCS0_RNE))
                                == (UDCCS0_OPR|UDCCS0_SA|UDCCS0_RNE))) {
                        int i;

                        nuke (ep, -EPROTO);

                        /* read SETUP packet */
                        for (i = 0; i < 8; i++) {
                                if (unlikely(!(UDCCS0 & UDCCS0_RNE))) {
bad_setup:
                                        DMSG("SETUP %d!\n", i);
                                        goto stall;
                                }
                                u.raw [i] = (u8) UDDR0;
                        }
                        if (unlikely((UDCCS0 & UDCCS0_RNE) != 0))
                                goto bad_setup;

got_setup:
                        DBG(DBG_VERBOSE, "SETUP %02x.%02x v%04x i%04x l%04x\n",
                                u.r.bRequestType, u.r.bRequest,
                                le16_to_cpu(u.r.wValue),
                                le16_to_cpu(u.r.wIndex),
                                le16_to_cpu(u.r.wLength));

                        /* cope with automagic for some standard requests. */
                        dev->req_std = (u.r.bRequestType & USB_TYPE_MASK)
                                                == USB_TYPE_STANDARD;
                        dev->req_config = 0;
                        dev->req_pending = 1;
                        switch (u.r.bRequest) {
                        /* hardware restricts gadget drivers here! */
                        case USB_REQ_SET_CONFIGURATION:
                                if (u.r.bRequestType == USB_RECIP_DEVICE) {
                                        /* reflect hardware's automagic
                                         * up to the gadget driver.
                                         */
config_change:
                                        dev->req_config = 1;
                                        clear_ep_state(dev);
                                        /* if !has_cfr, there's no synch
                                         * else use AREN (later) not SA|OPR
                                         * USIR0_IR0 acts edge sensitive
                                         */
                                }
                                break;
                        /* ... and here, even more ... */
                        case USB_REQ_SET_INTERFACE:
                                if (u.r.bRequestType == USB_RECIP_INTERFACE) {
                                        /* udc hardware is broken by design:
                                         *  - altsetting may only be zero;
                                         *  - hw resets all interfaces' eps;
                                         *  - ep reset doesn't include halt(?).
                                         */
                                        DMSG("broken set_interface (%d/%d)\n",
                                                le16_to_cpu(u.r.wIndex),
                                                le16_to_cpu(u.r.wValue));
                                        goto config_change;
                                }
                                break;
                        /* hardware was supposed to hide this */
                        case USB_REQ_SET_ADDRESS:
                                if (u.r.bRequestType == USB_RECIP_DEVICE) {
                                        ep0start(dev, 0, "address");
                                        return;
                                }
                                break;
                        }

                        if (u.r.bRequestType & USB_DIR_IN)
                                dev->ep0state = EP0_IN_DATA_PHASE;
                        else
                                dev->ep0state = EP0_OUT_DATA_PHASE;

                        i = dev->driver->setup(&dev->gadget, &u.r);
                        if (i < 0) {
                                /* hardware automagic preventing STALL... */
                                if (dev->req_config) {
                                        /* hardware sometimes neglects to tell
                                         * tell us about config change events,
                                         * so later ones may fail...
                                         */
                                        WARN("config change %02x fail %d?\n",
                                                u.r.bRequest, i);
                                        return;
                                        /* TODO experiment:  if has_cfr,
                                         * hardware didn't ACK; maybe we
                                         * could actually STALL!
                                         */
                                }
                                DBG(DBG_VERBOSE, "protocol STALL, "
                                        "%02x err %d\n", UDCCS0, i);
stall:
                                /* the watchdog timer helps deal with cases
                                 * where udc seems to clear FST wrongly, and
                                 * then NAKs instead of STALLing.
                                 */
                                ep0start(dev, UDCCS0_FST|UDCCS0_FTF, "stall");
                                start_watchdog(dev);
                                dev->ep0state = EP0_STALL;

                        /* deferred i/o == no response yet */
                        } else if (dev->req_pending) {
                                if (likely(dev->ep0state == EP0_IN_DATA_PHASE
                                                || dev->req_std || u.r.wLength))
                                        ep0start(dev, 0, "defer");
                                else
                                        ep0start(dev, UDCCS0_IPR, "defer/IPR");
                        }

                        /* expect at least one data or status stage irq */
                        return;

                } else if (likely((udccs0 & (UDCCS0_OPR|UDCCS0_SA))
                                == (UDCCS0_OPR|UDCCS0_SA))) {
                        unsigned i;

                        /* pxa210/250 erratum 131 for B0/B1 says RNE lies.
                         * still observed on a pxa255 a0.
                         */
                        DBG(DBG_VERBOSE, "e131\n");
                        nuke(ep, -EPROTO);

                        /* read SETUP data, but don't trust it too much */
                        for (i = 0; i < 8; i++)
                                u.raw [i] = (u8) UDDR0;
                        if ((u.r.bRequestType & USB_RECIP_MASK)
                                        > USB_RECIP_OTHER)
                                goto stall;
                        if (u.word [0] == 0 && u.word [1] == 0)
                                goto stall;
                        goto got_setup;
                } else {
                        /* some random early IRQ:
                         * - we acked FST
                         * - IPR cleared
                         * - OPR got set, without SA (likely status stage)
                         */
                        UDCCS0 = udccs0 & (UDCCS0_SA|UDCCS0_OPR);
                }
                break;
        case EP0_IN_DATA_PHASE:                 /* GET_DESCRIPTOR etc */
                if (udccs0 & UDCCS0_OPR) {
                        UDCCS0 = UDCCS0_OPR|UDCCS0_FTF;
                        DBG(DBG_VERBOSE, "ep0in premature status\n");
                        if (req)
                                done(ep, req, 0);
                        ep0_idle(dev);
                } else /* irq was IPR clearing */ {
                        if (req) {
                                /* this IN packet might finish the request */
                                (void) write_ep0_fifo(ep, req);
                        } /* else IN token before response was written */
                }
                break;
        case EP0_OUT_DATA_PHASE:                /* SET_DESCRIPTOR etc */
                if (udccs0 & UDCCS0_OPR) {
                        if (req) {
                                /* this OUT packet might finish the request */
                                if (read_ep0_fifo(ep, req))
                                        done(ep, req, 0);
                                /* else more OUT packets expected */
                        } /* else OUT token before read was issued */
                } else /* irq was IPR clearing */ {
                        DBG(DBG_VERBOSE, "ep0out premature status\n");
                        if (req)
                                done(ep, req, 0);
                        ep0_idle(dev);
                }
                break;
        case EP0_END_XFER:
                if (req)
                        done(ep, req, 0);
                /* ack control-IN status (maybe in-zlp was skipped)
                 * also appears after some config change events.
                 */
                if (udccs0 & UDCCS0_OPR)
                        UDCCS0 = UDCCS0_OPR;
                ep0_idle(dev);
                break;
        case EP0_STALL:
                UDCCS0 = UDCCS0_FST;
                break;
        }
        USIR0 = USIR0_IR0;
}

static void handle_ep(struct pxa2xx_ep *ep)
{
        struct pxa2xx_request   *req;
        int                     is_in = ep->bEndpointAddress & USB_DIR_IN;
        int                     completed;
        u32                     udccs, tmp;

        do {
                completed = 0;
                if (likely (!list_empty(&ep->queue)))
                        req = list_entry(ep->queue.next,
                                        struct pxa2xx_request, queue);
                else
                        req = NULL;

                // TODO check FST handling

                udccs = *ep->reg_udccs;
                if (unlikely(is_in)) {  /* irq from TPC, SST, or (ISO) TUR */
                        tmp = UDCCS_BI_TUR;
                        if (likely(ep->bmAttributes == USB_ENDPOINT_XFER_BULK))
                                tmp |= UDCCS_BI_SST;
                        tmp &= udccs;
                        if (likely (tmp))
                                *ep->reg_udccs = tmp;
                        if (req && likely ((udccs & UDCCS_BI_TFS) != 0))
                                completed = write_fifo(ep, req);

                } else {        /* irq from RPC (or for ISO, ROF) */
                        if (likely(ep->bmAttributes == USB_ENDPOINT_XFER_BULK))
                                tmp = UDCCS_BO_SST | UDCCS_BO_DME;
                        else
                                tmp = UDCCS_IO_ROF | UDCCS_IO_DME;
                        tmp &= udccs;
                        if (likely(tmp))
                                *ep->reg_udccs = tmp;

                        /* fifos can hold packets, ready for reading... */
                        if (likely(req)) {
                                completed = read_fifo(ep, req);
                        } else
                                pio_irq_disable (ep->bEndpointAddress);
                }
                ep->pio_irqs++;
        } while (completed);
}

/*
 *      pxa2xx_udc_irq - interrupt handler
 *
 * avoid delays in ep0 processing. the control handshaking isn't always
 * under software control (pxa250c0 and the pxa255 are better), and delays
 * could cause usb protocol errors.
 */
static irqreturn_t
pxa2xx_udc_irq(int irq, void *_dev)
{
        struct pxa2xx_udc       *dev = _dev;
        int                     handled;

        dev->stats.irqs++;
        do {
                u32             udccr = UDCCR;

                handled = 0;

                /* SUSpend Interrupt Request */
                if (unlikely(udccr & UDCCR_SUSIR)) {
                        udc_ack_int_UDCCR(UDCCR_SUSIR);
                        handled = 1;
                        DBG(DBG_VERBOSE, "USB suspend%s\n", is_vbus_present()
                                ? "" : "+disconnect");

                        if (!is_vbus_present())
                                stop_activity(dev, dev->driver);
                        else if (dev->gadget.speed != USB_SPEED_UNKNOWN
                                        && dev->driver
                                        && dev->driver->suspend)
                                dev->driver->suspend(&dev->gadget);
                        ep0_idle (dev);
                }

                /* RESume Interrupt Request */
                if (unlikely(udccr & UDCCR_RESIR)) {
                        udc_ack_int_UDCCR(UDCCR_RESIR);
                        handled = 1;
                        DBG(DBG_VERBOSE, "USB resume\n");

                        if (dev->gadget.speed != USB_SPEED_UNKNOWN
                                        && dev->driver
                                        && dev->driver->resume
                                        && is_vbus_present())
                                dev->driver->resume(&dev->gadget);
                }

                /* ReSeT Interrupt Request - USB reset */
                if (unlikely(udccr & UDCCR_RSTIR)) {
                        udc_ack_int_UDCCR(UDCCR_RSTIR);
                        handled = 1;

                        if ((UDCCR & UDCCR_UDA) == 0) {
                                DBG(DBG_VERBOSE, "USB reset start\n");

                                /* reset driver and endpoints,
                                 * in case that's not yet done
                                 */
                                stop_activity (dev, dev->driver);

                        } else {
                                DBG(DBG_VERBOSE, "USB reset end\n");
                                dev->gadget.speed = USB_SPEED_FULL;
                                memset(&dev->stats, 0, sizeof dev->stats);
                                /* driver and endpoints are still reset */
                        }

                } else {
                        u32     usir0 = USIR0 & ~UICR0;
                        u32     usir1 = USIR1 & ~UICR1;
                        int     i;

                        if (unlikely (!usir0 && !usir1))
                                continue;

                        DBG(DBG_VERY_NOISY, "irq %02x.%02x\n", usir1, usir0);

                        /* control traffic */
                        if (usir0 & USIR0_IR0) {
                                dev->ep[0].pio_irqs++;
                                handle_ep0(dev);
                                handled = 1;
                        }

                        /* endpoint data transfers */
                        for (i = 0; i < 8; i++) {
                                u32     tmp = 1 << i;

                                if (i && (usir0 & tmp)) {
                                        handle_ep(&dev->ep[i]);
                                        USIR0 |= tmp;
                                        handled = 1;
                                }
                                if (usir1 & tmp) {
                                        handle_ep(&dev->ep[i+8]);
                                        USIR1 |= tmp;
                                        handled = 1;
                                }
                        }
                }

                /* we could also ask for 1 msec SOF (SIR) interrupts */

        } while (handled);
        return IRQ_HANDLED;
}

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

static void nop_release (struct device *dev)
{
        DMSG("%s %s\n", __FUNCTION__, dev->bus_id);
}

/* this uses load-time allocation and initialization (instead of
 * doing it at run-time) to save code, eliminate fault paths, and
 * be more obviously correct.
 */
static struct pxa2xx_udc memory = {
        .gadget = {
                .ops            = &pxa2xx_udc_ops,
                .ep0            = &memory.ep[0].ep,
                .name           = driver_name,
                .dev = {
                        .bus_id         = "gadget",
                        .release        = nop_release,
                },
        },

        /* control endpoint */
        .ep[0] = {
                .ep = {
                        .name           = ep0name,
                        .ops            = &pxa2xx_ep_ops,
                        .maxpacket      = EP0_FIFO_SIZE,
                },
                .dev            = &memory,
                .reg_udccs      = &UDCCS0,
                .reg_uddr       = &UDDR0,
        },

        /* first group of endpoints */
        .ep[1] = {
                .ep = {
                        .name           = "ep1in-bulk",
                        .ops            = &pxa2xx_ep_ops,
                        .maxpacket      = BULK_FIFO_SIZE,
                },
                .dev            = &memory,
                .fifo_size      = BULK_FIFO_SIZE,
                .bEndpointAddress = USB_DIR_IN | 1,
                .bmAttributes   = USB_ENDPOINT_XFER_BULK,
                .reg_udccs      = &UDCCS1,
                .reg_uddr       = &UDDR1,
        },
        .ep[2] = {
                .ep = {
                        .name           = "ep2out-bulk",
                        .ops            = &pxa2xx_ep_ops,
                        .maxpacket      = BULK_FIFO_SIZE,
                },
                .dev            = &memory,
                .fifo_size      = BULK_FIFO_SIZE,
                .bEndpointAddress = 2,
                .bmAttributes   = USB_ENDPOINT_XFER_BULK,
                .reg_udccs      = &UDCCS2,
                .reg_ubcr       = &UBCR2,
                .reg_uddr       = &UDDR2,
        },
#ifndef CONFIG_USB_PXA2XX_SMALL
        .ep[3] = {
                .ep = {
                        .name           = "ep3in-iso",
                        .ops            = &pxa2xx_ep_ops,
                        .maxpacket      = ISO_FIFO_SIZE,
                },
                .dev            = &memory,
                .fifo_size      = ISO_FIFO_SIZE,
                .bEndpointAddress = USB_DIR_IN | 3,
                .bmAttributes   = USB_ENDPOINT_XFER_ISOC,
                .reg_udccs      = &UDCCS3,
                .reg_uddr       = &UDDR3,
        },
        .ep[4] = {
                .ep = {
                        .name           = "ep4out-iso",
                        .ops            = &pxa2xx_ep_ops,
                        .maxpacket      = ISO_FIFO_SIZE,
                },
                .dev            = &memory,
                .fifo_size      = ISO_FIFO_SIZE,
                .bEndpointAddress = 4,
                .bmAttributes   = USB_ENDPOINT_XFER_ISOC,
                .reg_udccs      = &UDCCS4,
                .reg_ubcr       = &UBCR4,
                .reg_uddr       = &UDDR4,
        },
        .ep[5] = {
                .ep = {
                        .name           = "ep5in-int",
                        .ops            = &pxa2xx_ep_ops,
                        .maxpacket      = INT_FIFO_SIZE,
                },
                .dev            = &memory,
                .fifo_size      = INT_FIFO_SIZE,
                .bEndpointAddress = USB_DIR_IN | 5,
                .bmAttributes   = USB_ENDPOINT_XFER_INT,
                .reg_udccs      = &UDCCS5,
                .reg_uddr       = &UDDR5,
        },

        /* second group of endpoints */
        .ep[6] = {
                .ep = {
                        .name           = "ep6in-bulk",
                        .ops            = &pxa2xx_ep_ops,
                        .maxpacket      = BULK_FIFO_SIZE,
                },
                .dev            = &memory,
                .fifo_size      = BULK_FIFO_SIZE,
                .bEndpointAddress = USB_DIR_IN | 6,
                .bmAttributes   = USB_ENDPOINT_XFER_BULK,
                .reg_udccs      = &UDCCS6,
                .reg_uddr       = &UDDR6,
        },
        .ep[7] = {
                .ep = {
                        .name           = "ep7out-bulk",
                        .ops            = &pxa2xx_ep_ops,
                        .maxpacket      = BULK_FIFO_SIZE,
                },
                .dev            = &memory,
                .fifo_size      = BULK_FIFO_SIZE,
                .bEndpointAddress = 7,
                .bmAttributes   = USB_ENDPOINT_XFER_BULK,
                .reg_udccs      = &UDCCS7,
                .reg_ubcr       = &UBCR7,
                .reg_uddr       = &UDDR7,
        },
        .ep[8] = {
                .ep = {
                        .name           = "ep8in-iso",
                        .ops            = &pxa2xx_ep_ops,
                        .maxpacket      = ISO_FIFO_SIZE,
                },
                .dev            = &memory,
                .fifo_size      = ISO_FIFO_SIZE,
                .bEndpointAddress = USB_DIR_IN | 8,
                .bmAttributes   = USB_ENDPOINT_XFER_ISOC,
                .reg_udccs      = &UDCCS8,
                .reg_uddr       = &UDDR8,
        },
        .ep[9] = {
                .ep = {
                        .name           = "ep9out-iso",
                        .ops            = &pxa2xx_ep_ops,
                        .maxpacket      = ISO_FIFO_SIZE,
                },
                .dev            = &memory,
                .fifo_size      = ISO_FIFO_SIZE,
                .bEndpointAddress = 9,
                .bmAttributes   = USB_ENDPOINT_XFER_ISOC,
                .reg_udccs      = &UDCCS9,
                .reg_ubcr       = &UBCR9,
                .reg_uddr       = &UDDR9,
        },
        .ep[10] = {
                .ep = {
                        .name           = "ep10in-int",
                        .ops            = &pxa2xx_ep_ops,
                        .maxpacket      = INT_FIFO_SIZE,
                },
                .dev            = &memory,
                .fifo_size      = INT_FIFO_SIZE,
                .bEndpointAddress = USB_DIR_IN | 10,
                .bmAttributes   = USB_ENDPOINT_XFER_INT,
                .reg_udccs      = &UDCCS10,
                .reg_uddr       = &UDDR10,
        },

        /* third group of endpoints */
        .ep[11] = {
                .ep = {
                        .name           = "ep11in-bulk",
                        .ops            = &pxa2xx_ep_ops,
                        .maxpacket      = BULK_FIFO_SIZE,
                },
                .dev            = &memory,
                .fifo_size      = BULK_FIFO_SIZE,
                .bEndpointAddress = USB_DIR_IN | 11,
                .bmAttributes   = USB_ENDPOINT_XFER_BULK,
                .reg_udccs      = &UDCCS11,
                .reg_uddr       = &UDDR11,
        },
        .ep[12] = {
                .ep = {
                        .name           = "ep12out-bulk",
                        .ops            = &pxa2xx_ep_ops,
                        .maxpacket      = BULK_FIFO_SIZE,
                },
                .dev            = &memory,
                .fifo_size      = BULK_FIFO_SIZE,
                .bEndpointAddress = 12,
                .bmAttributes   = USB_ENDPOINT_XFER_BULK,
                .reg_udccs      = &UDCCS12,
                .reg_ubcr       = &UBCR12,
                .reg_uddr       = &UDDR12,
        },
        .ep[13] = {
                .ep = {
                        .name           = "ep13in-iso",
                        .ops            = &pxa2xx_ep_ops,
                        .maxpacket      = ISO_FIFO_SIZE,
                },
                .dev            = &memory,
                .fifo_size      = ISO_FIFO_SIZE,
                .bEndpointAddress = USB_DIR_IN | 13,
                .bmAttributes   = USB_ENDPOINT_XFER_ISOC,
                .reg_udccs      = &UDCCS13,
                .reg_uddr       = &UDDR13,
        },
        .ep[14] = {
                .ep = {
                        .name           = "ep14out-iso",
                        .ops            = &pxa2xx_ep_ops,
                        .maxpacket      = ISO_FIFO_SIZE,
                },
                .dev            = &memory,
                .fifo_size      = ISO_FIFO_SIZE,
                .bEndpointAddress = 14,
                .bmAttributes   = USB_ENDPOINT_XFER_ISOC,
                .reg_udccs      = &UDCCS14,
                .reg_ubcr       = &UBCR14,
                .reg_uddr       = &UDDR14,
        },
        .ep[15] = {
                .ep = {
                        .name           = "ep15in-int",
                        .ops            = &pxa2xx_ep_ops,
                        .maxpacket      = INT_FIFO_SIZE,
                },
                .dev            = &memory,
                .fifo_size      = INT_FIFO_SIZE,
                .bEndpointAddress = USB_DIR_IN | 15,
                .bmAttributes   = USB_ENDPOINT_XFER_INT,
                .reg_udccs      = &UDCCS15,
                .reg_uddr       = &UDDR15,
        },
#endif /* !CONFIG_USB_PXA2XX_SMALL */
};

#define CP15R0_VENDOR_MASK      0xffffe000

#if     defined(CONFIG_ARCH_PXA)
#define CP15R0_XSCALE_VALUE     0x69052000      /* intel/arm/xscale */

#elif   defined(CONFIG_ARCH_IXP4XX)
#define CP15R0_XSCALE_VALUE     0x69054000      /* intel/arm/ixp4xx */

#endif

#define CP15R0_PROD_MASK        0x000003f0
#define PXA25x                  0x00000100      /* and PXA26x */
#define PXA210                  0x00000120

#define CP15R0_REV_MASK         0x0000000f

#define CP15R0_PRODREV_MASK     (CP15R0_PROD_MASK | CP15R0_REV_MASK)

#define PXA255_A0               0x00000106      /* or PXA260_B1 */
#define PXA250_C0               0x00000105      /* or PXA26x_B0 */
#define PXA250_B2               0x00000104
#define PXA250_B1               0x00000103      /* or PXA260_A0 */
#define PXA250_B0               0x00000102
#define PXA250_A1               0x00000101
#define PXA250_A0               0x00000100

#define PXA210_C0               0x00000125
#define PXA210_B2               0x00000124
#define PXA210_B1               0x00000123
#define PXA210_B0               0x00000122
#define IXP425_A0               0x000001c1
#define IXP425_B0               0x000001f1
#define IXP465_AD               0x00000200

/*
 *      probe - binds to the platform device
 */
static int __init pxa2xx_udc_probe(struct platform_device *pdev)
{
        struct pxa2xx_udc *dev = &memory;
        int retval, vbus_irq, irq;
        u32 chiprev;

        /* insist on Intel/ARM/XScale */
        asm("mrc%? p15, 0, %0, c0, c0" : "=r" (chiprev));
        if ((chiprev & CP15R0_VENDOR_MASK) != CP15R0_XSCALE_VALUE) {
                pr_err("%s: not XScale!\n", driver_name);
                return -ENODEV;
        }

        /* trigger chiprev-specific logic */
        switch (chiprev & CP15R0_PRODREV_MASK) {
#if     defined(CONFIG_ARCH_PXA)
        case PXA255_A0:
                dev->has_cfr = 1;
                break;
        case PXA250_A0:
        case PXA250_A1:
                /* A0/A1 "not released"; ep 13, 15 unusable */
                /* fall through */
        case PXA250_B2: case PXA210_B2:
        case PXA250_B1: case PXA210_B1:
        case PXA250_B0: case PXA210_B0:
                /* OUT-DMA is broken ... */
                /* fall through */
        case PXA250_C0: case PXA210_C0:
                break;
#elif   defined(CONFIG_ARCH_IXP4XX)
        case IXP425_A0:
        case IXP425_B0:
        case IXP465_AD:
                dev->has_cfr = 1;
                break;
#endif
        default:
                pr_err("%s: unrecognized processor: %08x\n",
                        driver_name, chiprev);
                /* iop3xx, ixp4xx, ... */
                return -ENODEV;
        }

        irq = platform_get_irq(pdev, 0);
        if (irq < 0)
                return -ENODEV;

#ifdef  CONFIG_ARCH_PXA
        dev->clk = clk_get(&pdev->dev, "UDCCLK");
        if (IS_ERR(dev->clk)) {
                retval = PTR_ERR(dev->clk);
                goto err_clk;
        }
#endif

        pr_debug("%s: IRQ %d%s%s\n", driver_name, irq,
                dev->has_cfr ? "" : " (!cfr)",
                SIZE_STR "(pio)"
                );

        /* other non-static parts of init */
        dev->dev = &pdev->dev;
        dev->mach = pdev->dev.platform_data;

        if (dev->mach->gpio_vbus) {
                if ((retval = gpio_request(dev->mach->gpio_vbus,
                                "pxa2xx_udc GPIO VBUS"))) {
                        dev_dbg(&pdev->dev,
                                "can't get vbus gpio %d, err: %d\n",
                                dev->mach->gpio_vbus, retval);
                        goto err_gpio_vbus;
                }
                gpio_direction_input(dev->mach->gpio_vbus);
                vbus_irq = gpio_to_irq(dev->mach->gpio_vbus);
        } else
                vbus_irq = 0;

        if (dev->mach->gpio_pullup) {
                if ((retval = gpio_request(dev->mach->gpio_pullup,
                                "pca2xx_udc GPIO PULLUP"))) {
                        dev_dbg(&pdev->dev,
                                "can't get pullup gpio %d, err: %d\n",
                                dev->mach->gpio_pullup, retval);
                        goto err_gpio_pullup;
                }
                gpio_direction_output(dev->mach->gpio_pullup, 0);
        }

        init_timer(&dev->timer);
        dev->timer.function = udc_watchdog;
        dev->timer.data = (unsigned long) dev;

        device_initialize(&dev->gadget.dev);
        dev->gadget.dev.parent = &pdev->dev;
        dev->gadget.dev.dma_mask = pdev->dev.dma_mask;

        the_controller = dev;
        platform_set_drvdata(pdev, dev);

        udc_disable(dev);
        udc_reinit(dev);

        dev->vbus = is_vbus_present();

        /* irq setup after old hardware state is cleaned up */
        retval = request_irq(irq, pxa2xx_udc_irq,
                        IRQF_DISABLED, driver_name, dev);
        if (retval != 0) {
                pr_err("%s: can't get irq %d, err %d\n",
                        driver_name, irq, retval);
                goto err_irq1;
        }
        dev->got_irq = 1;

#ifdef CONFIG_ARCH_LUBBOCK
        if (machine_is_lubbock()) {
                retval = request_irq(LUBBOCK_USB_DISC_IRQ,
                                lubbock_vbus_irq,
                                IRQF_DISABLED | IRQF_SAMPLE_RANDOM,
                                driver_name, dev);
                if (retval != 0) {
                        pr_err("%s: can't get irq %i, err %d\n",
                                driver_name, LUBBOCK_USB_DISC_IRQ, retval);
lubbock_fail0:
                        goto err_irq_lub;
                }
                retval = request_irq(LUBBOCK_USB_IRQ,
                                lubbock_vbus_irq,
                                IRQF_DISABLED | IRQF_SAMPLE_RANDOM,
                                driver_name, dev);
                if (retval != 0) {
                        pr_err("%s: can't get irq %i, err %d\n",
                                driver_name, LUBBOCK_USB_IRQ, retval);
                        free_irq(LUBBOCK_USB_DISC_IRQ, dev);
                        goto lubbock_fail0;
                }
        } else
#endif
        if (vbus_irq) {
                retval = request_irq(vbus_irq, udc_vbus_irq,
                                IRQF_DISABLED | IRQF_SAMPLE_RANDOM |
                                IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
                                driver_name, dev);
                if (retval != 0) {
                        pr_err("%s: can't get irq %i, err %d\n",
                                driver_name, vbus_irq, retval);
                        goto err_vbus_irq;
                }
        }
        create_proc_files();

        return 0;

 err_vbus_irq:
#ifdef  CONFIG_ARCH_LUBBOCK
        free_irq(LUBBOCK_USB_DISC_IRQ, dev);
 err_irq_lub:
#endif
        free_irq(irq, dev);
 err_irq1:
        if (dev->mach->gpio_pullup)
                gpio_free(dev->mach->gpio_pullup);
 err_gpio_pullup:
        if (dev->mach->gpio_vbus)
                gpio_free(dev->mach->gpio_vbus);
 err_gpio_vbus:
#ifdef  CONFIG_ARCH_PXA
        clk_put(dev->clk);
 err_clk:
#endif
        return retval;
}

static void pxa2xx_udc_shutdown(struct platform_device *_dev)
{
        pullup_off();
}

static int __exit pxa2xx_udc_remove(struct platform_device *pdev)
{
        struct pxa2xx_udc *dev = platform_get_drvdata(pdev);

        if (dev->driver)
                return -EBUSY;

        udc_disable(dev);
        remove_proc_files();

        if (dev->got_irq) {
                free_irq(platform_get_irq(pdev, 0), dev);
                dev->got_irq = 0;
        }
#ifdef CONFIG_ARCH_LUBBOCK
        if (machine_is_lubbock()) {
                free_irq(LUBBOCK_USB_DISC_IRQ, dev);
                free_irq(LUBBOCK_USB_IRQ, dev);
        }
#endif
        if (dev->mach->gpio_vbus) {
                free_irq(gpio_to_irq(dev->mach->gpio_vbus), dev);
                gpio_free(dev->mach->gpio_vbus);
        }
        if (dev->mach->gpio_pullup)
                gpio_free(dev->mach->gpio_pullup);

#ifdef  CONFIG_ARCH_PXA
        clk_put(dev->clk);
#endif

        platform_set_drvdata(pdev, NULL);
        the_controller = NULL;
        return 0;
}

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

#ifdef  CONFIG_PM

/* USB suspend (controlled by the host) and system suspend (controlled
 * by the PXA) don't necessarily work well together.  If USB is active,
 * the 48 MHz clock is required; so the system can't enter 33 MHz idle
 * mode, or any deeper PM saving state.
 *
 * For now, we punt and forcibly disconnect from the USB host when PXA
 * enters any suspend state.  While we're disconnected, we always disable
 * the 48MHz USB clock ... allowing PXA sleep and/or 33 MHz idle states.
 * Boards without software pullup control shouldn't use those states.
 * VBUS IRQs should probably be ignored so that the PXA device just acts
 * "dead" to USB hosts until system resume.
 */
static int pxa2xx_udc_suspend(struct platform_device *dev, pm_message_t state)
{
        struct pxa2xx_udc       *udc = platform_get_drvdata(dev);

        if (!udc->mach->gpio_pullup && !udc->mach->udc_command)
                WARN("USB host won't detect disconnect!\n");
        pullup(udc, 0);

        return 0;
}

static int pxa2xx_udc_resume(struct platform_device *dev)
{
        struct pxa2xx_udc       *udc = platform_get_drvdata(dev);

        pullup(udc, 1);

        return 0;
}

#else
#define pxa2xx_udc_suspend      NULL
#define pxa2xx_udc_resume       NULL
#endif

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

static struct platform_driver udc_driver = {
        .shutdown       = pxa2xx_udc_shutdown,
        .remove         = __exit_p(pxa2xx_udc_remove),
        .suspend        = pxa2xx_udc_suspend,
        .resume         = pxa2xx_udc_resume,
        .driver         = {
                .owner  = THIS_MODULE,
                .name   = "pxa2xx-udc",
        },
};

static int __init udc_init(void)
{
        pr_info("%s: version %s\n", driver_name, DRIVER_VERSION);
        return platform_driver_probe(&udc_driver, pxa2xx_udc_probe);
}
module_init(udc_init);

static void __exit udc_exit(void)
{
        platform_driver_unregister(&udc_driver);
}
module_exit(udc_exit);

MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_AUTHOR("Frank Becker, Robert Schwebel, David Brownell");
MODULE_LICENSE("GPL");