/*
 * 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
 * Copyright (C) 2012 Lukasz Dalek <luk0104@gmail.com>
 *
 * 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
 *
 * MODULE_AUTHOR("Frank Becker, Robert Schwebel, David Brownell");
 */

#define CONFIG_USB_PXA25X_SMALL
#define DRIVER_NAME "pxa25x_udc_linux"
#define ARCH_HAS_PREFETCH

#include <common.h>
#include <errno.h>
#include <asm/byteorder.h>
#include <asm/system.h>
#include <asm/mach-types.h>
#include <asm/unaligned.h>
#include <linux/compat.h>
#include <malloc.h>
#include <asm/io.h>
#include <asm/arch/pxa.h>

#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>
#include <usb/lin_gadget_compat.h>
#include <asm/arch/pxa-regs.h>

#include "pxa25x_udc.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  "18-August-2012"
#define DRIVER_DESC     "PXA 25x USB Device Controller driver"

static const char driver_name[] = "pxa25x_udc";
static const char ep0name[] = "ep0";

/* Watchdog */
static inline void start_watchdog(struct pxa25x_udc *udc)
{
        debug("Started watchdog\n");
        udc->watchdog.base = get_timer(0);
        udc->watchdog.running = 1;
}

static inline void stop_watchdog(struct pxa25x_udc *udc)
{
        udc->watchdog.running = 0;
        debug("Stopped watchdog\n");
}

static inline void test_watchdog(struct pxa25x_udc *udc)
{
        if (!udc->watchdog.running)
                return;

        debug("watchdog %ld %ld\n", get_timer(udc->watchdog.base),
                udc->watchdog.period);

        if (get_timer(udc->watchdog.base) >= udc->watchdog.period) {
                stop_watchdog(udc);
                udc->watchdog.function(udc);
        }
}

static void udc_watchdog(struct pxa25x_udc *dev)
{
        uint32_t udccs0 = readl(&dev->regs->udccs[0]);

        debug("Fired up udc_watchdog\n");

        local_irq_disable();
        if (dev->ep0state == EP0_STALL
                        && (udccs0 & UDCCS0_FST) == 0
                        && (udccs0 & UDCCS0_SST) == 0) {
                writel(UDCCS0_FST|UDCCS0_FTF, &dev->regs->udccs[0]);
                debug("ep0 re-stall\n");
                start_watchdog(dev);
        }
        local_irq_enable();
}

#ifdef DEBUG

static const char * const state_name[] = {
        "EP0_IDLE",
        "EP0_IN_DATA_PHASE", "EP0_OUT_DATA_PHASE",
        "EP0_END_XFER", "EP0_STALL"
};

static void
dump_udccr(const char *label)
{
        u32 udccr = readl(&UDC_REGS->udccr);
        debug("%s %02X =%s%s%s%s%s%s%s%s\n",
                label, udccr,
                (udccr & UDCCR_REM) ? " rem" : "",
                (udccr & UDCCR_RSTIR) ? " rstir" : "",
                (udccr & UDCCR_SRM) ? " srm" : "",
                (udccr & UDCCR_SUSIR) ? " susir" : "",
                (udccr & UDCCR_RESIR) ? " resir" : "",
                (udccr & UDCCR_RSM) ? " rsm" : "",
                (udccr & UDCCR_UDA) ? " uda" : "",
                (udccr & UDCCR_UDE) ? " ude" : "");
}

static void
dump_udccs0(const char *label)
{
        u32 udccs0 = readl(&UDC_REGS->udccs[0]);

        debug("%s %s %02X =%s%s%s%s%s%s%s%s\n",
                label, state_name[the_controller->ep0state], udccs0,
                (udccs0 & UDCCS0_SA) ? " sa" : "",
                (udccs0 & UDCCS0_RNE) ? " rne" : "",
                (udccs0 & UDCCS0_FST) ? " fst" : "",
                (udccs0 & UDCCS0_SST) ? " sst" : "",
                (udccs0 & UDCCS0_DRWF) ? " dwrf" : "",
                (udccs0 & UDCCS0_FTF) ? " ftf" : "",
                (udccs0 & UDCCS0_IPR) ? " ipr" : "",
                (udccs0 & UDCCS0_OPR) ? " opr" : "");
}

static void
dump_state(struct pxa25x_udc *dev)
{
        u32 tmp;
        unsigned i;

        debug("%s, uicr %02X.%02X, usir %02X.%02x, ufnr %02X.%02X\n",
                state_name[dev->ep0state],
                readl(&UDC_REGS->uicr1), readl(&UDC_REGS->uicr0),
                readl(&UDC_REGS->usir1), readl(&UDC_REGS->usir0),
                readl(&UDC_REGS->ufnrh), readl(&UDC_REGS->ufnrl));
        dump_udccr("udccr");
        if (dev->has_cfr) {
                tmp = readl(&UDC_REGS->udccfr);
                debug("udccfr %02X =%s%s\n", tmp,
                        (tmp & UDCCFR_AREN) ? " aren" : "",
                        (tmp & UDCCFR_ACM) ? " acm" : "");
        }

        if (!dev->driver) {
                debug("no gadget driver bound\n");
                return;
        } else
                debug("ep0 driver '%s'\n", "ether");

        dump_udccs0("udccs0");
        debug("ep0 IN %lu/%lu, OUT %lu/%lu\n",
                dev->stats.write.bytes, dev->stats.write.ops,
                dev->stats.read.bytes, dev->stats.read.ops);

        for (i = 1; i < PXA_UDC_NUM_ENDPOINTS; i++) {
                if (dev->ep[i].desc == NULL)
                        continue;
                debug("udccs%d = %02x\n", i, *dev->ep->reg_udccs);
        }
}

#else /* DEBUG */

static inline void dump_udccr(const char *label) { }
static inline void dump_udccs0(const char *label) { }
static inline void dump_state(struct pxa25x_udc *dev) { }

#endif /* DEBUG */

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

static void pxa25x_ep_fifo_flush(struct usb_ep *ep);
static void nuke(struct pxa25x_ep *, int status);

/* 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->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->udc_command)
                mach->udc_command(PXA2XX_UDC_CMD_CONNECT);
}

static void pio_irq_enable(int bEndpointAddress)
{
        bEndpointAddress &= 0xf;
        if (bEndpointAddress < 8) {
                clrbits_le32(&the_controller->regs->uicr0,
                        1 << bEndpointAddress);
        } else {
                bEndpointAddress -= 8;
                clrbits_le32(&the_controller->regs->uicr1,
                        1 << bEndpointAddress);
        }
}

static void pio_irq_disable(int bEndpointAddress)
{
        bEndpointAddress &= 0xf;
        if (bEndpointAddress < 8) {
                setbits_le32(&the_controller->regs->uicr0,
                        1 << bEndpointAddress);
        } else {
                bEndpointAddress -= 8;
                setbits_le32(&the_controller->regs->uicr1,
                        1 << bEndpointAddress);
        }
}

static inline void udc_set_mask_UDCCR(int mask)
{
        /*
         * The UDCCR reg contains mask and interrupt status bits,
         * so using '|=' isn't safe as it may ack an interrupt.
         */
        const uint32_t mask_bits = UDCCR_REM | UDCCR_SRM | UDCCR_UDE;

        mask &= mask_bits;
        clrsetbits_le32(&the_controller->regs->udccr, ~mask_bits, mask);
}

static inline void udc_clear_mask_UDCCR(int mask)
{
        const uint32_t mask_bits = UDCCR_REM | UDCCR_SRM | UDCCR_UDE;

        mask = ~mask & mask_bits;
        clrbits_le32(&the_controller->regs->udccr, ~mask);
}

static inline void udc_ack_int_UDCCR(int mask)
{
        const uint32_t mask_bits = UDCCR_REM | UDCCR_SRM | UDCCR_UDE;

        mask &= ~mask_bits;
        clrsetbits_le32(&the_controller->regs->udccr, ~mask_bits, mask);
}

/*
 * endpoint enable/disable
 *
 * we need to verify the descriptors used to enable endpoints.  since pxa25x
 * endpoint configurations are fixed, and are pretty much always enabled,
 * there's not a lot to manage here.
 *
 * because pxa25x 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 pxa25x_ep_enable(struct usb_ep *_ep,
                const struct usb_endpoint_descriptor *desc)
{
        struct pxa25x_ep *ep;
        struct pxa25x_udc *dev;

        ep = container_of(_ep, struct pxa25x_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)) {
                printf("%s, bad ep or descriptor\n", __func__);
                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) {
                printf("%s, %s type mismatch\n", __func__, _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) {
                printf("%s, bad %s maxpacket\n", __func__, _ep->name);
                return -ERANGE;
        }

        dev = ep->dev;
        if (!dev->driver || dev->gadget.speed == USB_SPEED_UNKNOWN) {
                printf("%s, bogus device state\n", __func__);
                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) */
        pxa25x_ep_fifo_flush(_ep);

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

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

static int pxa25x_ep_disable(struct usb_ep *_ep)
{
        struct pxa25x_ep *ep;
        unsigned long flags;

        ep = container_of(_ep, struct pxa25x_ep, ep);
        if (!_ep || !ep->desc) {
                printf("%s, %s not enabled\n", __func__,
                        _ep ? ep->ep.name : NULL);
                return -EINVAL;
        }
        local_irq_save(flags);

        nuke(ep, -ESHUTDOWN);

        /* flush fifo (mostly for IN buffers) */
        pxa25x_ep_fifo_flush(_ep);

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

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

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

/*
 * for the pxa25x, 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).
 */

/*
 *      pxa25x_ep_alloc_request - allocate a request data structure
 */
static struct usb_request *
pxa25x_ep_alloc_request(struct usb_ep *_ep, gfp_t gfp_flags)
{
        struct pxa25x_request *req;

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

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


/*
 *      pxa25x_ep_free_request - deallocate a request data structure
 */
static void
pxa25x_ep_free_request(struct usb_ep *_ep, struct usb_request *_req)
{
        struct pxa25x_request   *req;

        req = container_of(_req, struct pxa25x_request, req);
        WARN_ON(!list_empty(&req->queue));
        kfree(req);
}

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

/*
 *      done - retire a request; caller blocked irqs
 */
static void done(struct pxa25x_ep *ep, struct pxa25x_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)
                debug("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 pxa25x_udc *dev)
{
        dev->ep0state = EP0_IDLE;
}

static int
write_packet(u32 *uddr, struct pxa25x_request *req, unsigned max)
{
        u8 *buf;
        unsigned length, count;

        debug("%s(): uddr %p\n", __func__, uddr);

        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--))
                writeb(*buf++, uddr);

        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 pxa25x_ep *ep, struct pxa25x_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);
                }

                debug_cond(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.
                 */
                writel(UDCCS_BI_TPC, ep->reg_udccs);
                if (is_short)
                        writel(UDCCS_BI_TSP, ep->reg_udccs);

                /* 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 (readl(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 pxa25x_udc *dev, u32 flags, const char *tag)
{
        writel(flags|UDCCS0_SA|UDCCS0_OPR, &dev->regs->udccs[0]);
        writel(USIR0_IR0, &dev->regs->usir0);
        dev->req_pending = 0;
        debug_cond(NOISY, "%s() %s, udccs0: %02x/%02x usir: %X.%X\n",
                __func__, tag, readl(&dev->regs->udccs[0]), flags,
                readl(&dev->regs->usir1), readl(&dev->regs->usir0));
}

static int
write_ep0_fifo(struct pxa25x_ep *ep, struct pxa25x_request *req)
{
        unsigned count;
        int is_short;

        count = write_packet(&ep->dev->regs->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);

        debug_cond(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
                        writel(UDCCS0_IPR, &ep->dev->regs->udccs[0]);

                count = req->req.length;
                done(ep, req, 0);
                ep0_idle(ep->dev);

                /*
                 * 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 ((readl(&ep->dev->regs->udccs[0]) &
                                     UDCCS0_OPR) != 0) {
                                        /* clear OPR, generate ack */
                                        writel(UDCCS0_OPR,
                                                &ep->dev->regs->udccs[0]);
                                        break;
                                }
                                count--;
                                udelay(1);
                        } while (count);
                }
        } 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 pxa25x_ep *ep, struct pxa25x_request *req)
{
        u32 udccs;
        u8 *buf;
        unsigned bufferspace, count, is_short;

        for (;;) {
                /*
                 * 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 = readl(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 & readl(ep->reg_ubcr));
                        req->req.actual += min(count, bufferspace);
                } else /* zlp */
                        count = 0;
                is_short = (count < ep->ep.maxpacket);
                debug_cond(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 = readb(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)
                                        printf("%s overflow %d\n",
                                                ep->ep.name, count);
                                req->req.status = -EOVERFLOW;
                        } else {
                                *buf++ = byte;
                                bufferspace--;
                        }
                }
                writel(UDCCS_BO_RPC, ep->reg_udccs);
                /* 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 pxa25x_ep *ep, struct pxa25x_request *req)
{
        u8 *buf, byte;
        unsigned bufferspace;

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

        while (readl(&ep->dev->regs->udccs[0]) & UDCCS0_RNE) {
                byte = (u8)readb(&ep->dev->regs->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)
                                printf("%s overflow\n", ep->ep.name);
                        req->req.status = -EOVERFLOW;
                } else {
                        *buf++ = byte;
                        req->req.actual++;
                        bufferspace--;
                }
        }

        writel(UDCCS0_OPR | UDCCS0_IPR, &ep->dev->regs->udccs[0]);

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

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

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

static int
pxa25x_ep_queue(struct usb_ep *_ep, struct usb_request *_req, gfp_t gfp_flags)
{
        struct pxa25x_request *req;
        struct pxa25x_ep *ep;
        struct pxa25x_udc *dev;
        unsigned long flags;

        req = container_of(_req, struct pxa25x_request, req);
        if (unlikely(!_req || !_req->complete || !_req->buf
                        || !list_empty(&req->queue))) {
                printf("%s, bad params\n", __func__);
                return -EINVAL;
        }

        ep = container_of(_ep, struct pxa25x_ep, ep);
        if (unlikely(!_ep || (!ep->desc && ep->ep.name != ep0name))) {
                printf("%s, bad ep\n", __func__);
                return -EINVAL;
        }

        dev = ep->dev;
        if (unlikely(!dev->driver
                        || dev->gadget.speed == USB_SPEED_UNKNOWN)) {
                printf("%s, bogus device state\n", __func__);
                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;

        debug_cond(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 == NULL/* 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) {
                                        debug("ep0 config ack%s\n",
                                                dev->has_cfr ?  "" : " raced");
                                        if (dev->has_cfr)
                                                writel(UDCCFR_AREN|UDCCFR_ACM
                                                        |UDCCFR_MB1,
                                                        &ep->dev->regs->udccfr);
                                        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 ||
                                                ((readl(
                                                &ep->dev->regs->udccs[0])
                                                & UDCCS0_RNE) != 0
                                                && read_ep0_fifo(ep, req))) {
                                        ep0_idle(dev);
                                        done(ep, req, 0);
                                        req = NULL;
                                }
                                break;

                        default:
                                printf("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 ((readl(ep->reg_udccs) & UDCCS_BI_TFS) != 0
                                        && write_fifo(ep, req))
                                req = NULL;
                } else if ((readl(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 != NULL))
                list_add_tail(&req->queue, &ep->queue);
        local_irq_restore(flags);

        return 0;
}


/*
 *      nuke - dequeue ALL requests
 */
static void nuke(struct pxa25x_ep *ep, int status)
{
        struct pxa25x_request *req;

        /* called with irqs blocked */
        while (!list_empty(&ep->queue)) {
                req = list_entry(ep->queue.next,
                                struct pxa25x_request,
                                queue);
                done(ep, req, status);
        }
        if (ep->desc)
                pio_irq_disable(ep->bEndpointAddress);
}


/* dequeue JUST ONE request */
static int pxa25x_ep_dequeue(struct usb_ep *_ep, struct usb_request *_req)
{
        struct pxa25x_ep *ep;
        struct pxa25x_request *req;
        unsigned long flags;

        ep = container_of(_ep, struct pxa25x_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 pxa25x_ep_set_halt(struct usb_ep *_ep, int value)
{
        struct pxa25x_ep *ep;
        unsigned long flags;

        ep = container_of(_ep, struct pxa25x_ep, ep);
        if (unlikely(!_ep
                        || (!ep->desc && ep->ep.name != ep0name))
                        || ep->bmAttributes == USB_ENDPOINT_XFER_ISOC) {
                printf("%s, bad ep\n", __func__);
                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.
                 */
                printf("only host can clear %s halt\n", _ep->name);
                return -EROFS;
        }

        local_irq_save(flags);

        if ((ep->bEndpointAddress & USB_DIR_IN) != 0
                        && ((readl(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 */
        writel(UDCCS_BI_FST|UDCCS_BI_FTF, ep->reg_udccs);

        /* 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 (readl(ep->reg_udccs) & UDCCS_BI_SST)
                                break;
                        udelay(20);
                }
        }
        local_irq_restore(flags);

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

static int pxa25x_ep_fifo_status(struct usb_ep *_ep)
{
        struct pxa25x_ep        *ep;

        ep = container_of(_ep, struct pxa25x_ep, ep);
        if (!_ep) {
                printf("%s, bad ep\n", __func__);
                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
                        || (readl(ep->reg_udccs) & UDCCS_BO_RFS) == 0)
                return 0;
        else
                return (readl(ep->reg_ubcr) & 0xfff) + 1;
}

static void pxa25x_ep_fifo_flush(struct usb_ep *_ep)
{
        struct pxa25x_ep        *ep;

        ep = container_of(_ep, struct pxa25x_ep, ep);
        if (!_ep || ep->ep.name == ep0name || !list_empty(&ep->queue)) {
                printf("%s, bad ep\n", __func__);
                return;
        }

        /* toggle and halt bits stay unchanged */

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

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


static struct usb_ep_ops pxa25x_ep_ops = {

        .enable         = pxa25x_ep_enable,
        .disable        = pxa25x_ep_disable,

        .alloc_request  = pxa25x_ep_alloc_request,
        .free_request   = pxa25x_ep_free_request,

        .queue          = pxa25x_ep_queue,
        .dequeue        = pxa25x_ep_dequeue,

        .set_halt       = pxa25x_ep_set_halt,
        .fifo_status    = pxa25x_ep_fifo_status,
        .fifo_flush     = pxa25x_ep_fifo_flush,
};


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

static int pxa25x_udc_get_frame(struct usb_gadget *_gadget)
{
        return ((readl(&the_controller->regs->ufnrh) & 0x07) << 8) |
                (readl(&the_controller->regs->ufnrl) & 0xff);
}

static int pxa25x_udc_wakeup(struct usb_gadget *_gadget)
{
        /* host may not have enabled remote wakeup */
        if ((readl(&the_controller->regs->udccs[0]) & UDCCS0_DRWF) == 0)
                return -EHOSTUNREACH;
        udc_set_mask_UDCCR(UDCCR_RSM);
        return 0;
}

static void stop_activity(struct pxa25x_udc *, struct usb_gadget_driver *);
static void udc_enable(struct pxa25x_udc *);
static void udc_disable(struct pxa25x_udc *);

/*
 * We disable the UDC -- and its 48 MHz clock -- whenever it's not
 * in active use.
 */
static int pullup(struct pxa25x_udc *udc)
{
        if (udc->pullup)
                pullup_on();
        else
                pullup_off();


        int is_active = udc->pullup;
        if (is_active) {
                if (!udc->active) {
                        udc->active = 1;
                        udc_enable(udc);
                }
        } else {
                if (udc->active) {
                        if (udc->gadget.speed != USB_SPEED_UNKNOWN)
                                stop_activity(udc, udc->driver);
                        udc_disable(udc);
                        udc->active = 0;
                }

        }
        return 0;
}

/* VBUS reporting logically comes from a transceiver */
static int pxa25x_udc_vbus_session(struct usb_gadget *_gadget, int is_active)
{
        struct pxa25x_udc *udc;

        udc = container_of(_gadget, struct pxa25x_udc, gadget);
        printf("vbus %s\n", is_active ? "supplied" : "inactive");
        pullup(udc);
        return 0;
}

/* drivers may have software control over D+ pullup */
static int pxa25x_udc_pullup(struct usb_gadget *_gadget, int is_active)
{
        struct pxa25x_udc       *udc;

        udc = container_of(_gadget, struct pxa25x_udc, gadget);

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

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

/*
 * 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.
 */
static int pxa25x_udc_vbus_draw(struct usb_gadget *_gadget, unsigned mA)
{
        return -EOPNOTSUPP;
}

static const struct usb_gadget_ops pxa25x_udc_ops = {
        .get_frame      = pxa25x_udc_get_frame,
        .wakeup         = pxa25x_udc_wakeup,
        .vbus_session   = pxa25x_udc_vbus_session,
        .pullup         = pxa25x_udc_pullup,
        .vbus_draw      = pxa25x_udc_vbus_draw,
};

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

/*
 *      udc_disable - disable USB device controller
 */
static void udc_disable(struct pxa25x_udc *dev)
{
        /* block all irqs */
        udc_set_mask_UDCCR(UDCCR_SRM|UDCCR_REM);
        writel(0xff, &dev->regs->uicr0);
        writel(0xff, &dev->regs->uicr1);
        writel(UFNRH_SIM, &dev->regs->ufnrh);

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

        udc_clear_mask_UDCCR(UDCCR_UDE);

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

/*
 *      udc_reinit - initialize software state
 */
static void udc_reinit(struct pxa25x_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 pxa25x_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 pxa25x_udc *dev)
{
        debug("udc: enabling udc\n");

        udc_clear_mask_UDCCR(UDCCR_UDE);

        /*
         * Try to clear these bits before we enable the udc.
         * Do not touch reset ack bit, we would take care of it in
         * interrupt handle routine
         */
        udc_ack_int_UDCCR(UDCCR_SUSIR|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 (!(readl(&dev->regs->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
                 */
                writel(UDCCFR_ACM | UDCCFR_MB1, &dev->regs->udccfr);
        }

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

        /* enable ep0 irqs */
        clrbits_le32(&dev->regs->uicr0, UICR0_IM0);

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

static inline void clear_ep_state(struct pxa25x_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 handle_ep0(struct pxa25x_udc *dev)
{
        u32 udccs0 = readl(&dev->regs->udccs[0]);
        struct pxa25x_ep *ep = &dev->ep[0];
        struct pxa25x_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 pxa25x_request, queue);

        /* clear stall status */
        if (udccs0 & UDCCS0_SST) {
                nuke(ep, -EPIPE);
                writel(UDCCS0_SST, &dev->regs->udccs[0]);
                stop_watchdog(dev);
                ep0_idle(dev);
        }

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

        switch (dev->ep0state) {
        case EP0_IDLE:
                /* late-breaking status? */
                udccs0 = readl(&dev->regs->udccs[0]);

                /* 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(!(readl(&dev->regs->udccs[0]) &
                                                UDCCS0_RNE))) {
bad_setup:
                                        debug("SETUP %d!\n", i);
                                        goto stall;
                                }
                                u.raw[i] = (u8)readb(&dev->regs->uddr0);
                        }
                        if (unlikely((readl(&dev->regs->udccs[0]) &
                                        UDCCS0_RNE) != 0))
                                goto bad_setup;

got_setup:
                        debug("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:
                                debug("GOT SET_CONFIGURATION\n");
                                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(?).
                                         */
                                        printf("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:
                                debug("GOT SET ADDRESS\n");
                                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...
                                         */
                                        printf("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!
                                         */
                                }
                                if (0) {
stall:
                                        /* uninitialized when goto stall */
                                        i = 0;
                                }
                                debug("protocol STALL, "
                                        "%02x err %d\n",
                                        readl(&dev->regs->udccs[0]), i);

                                /*
                                 * 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.
                         */
                        debug("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)readb(&dev->regs->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)
                         */
                        debug("random IRQ %X %X\n", udccs0,
                                readl(&dev->regs->udccs[0]));
                        writel(udccs0 & (UDCCS0_SA|UDCCS0_OPR),
                                &dev->regs->udccs[0]);
                }
                break;
        case EP0_IN_DATA_PHASE:                 /* GET_DESCRIPTOR etc */
                if (udccs0 & UDCCS0_OPR) {
                        debug("ep0in premature status\n");
                        if (req)
                                done(ep, req, 0);
                        ep0_idle(dev);
                } else /* irq was IPR clearing */ {
                        if (req) {
                                debug("next ep0 in packet\n");
                                /* 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 */ {
                        debug("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)
                        writel(UDCCS0_OPR, &dev->regs->udccs[0]);
                ep0_idle(dev);
                break;
        case EP0_STALL:
                writel(UDCCS0_FST, &dev->regs->udccs[0]);
                break;
        }

        writel(USIR0_IR0, &dev->regs->usir0);
}

static void handle_ep(struct pxa25x_ep *ep)
{
        struct pxa25x_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 pxa25x_request, queue);
                else
                        req = NULL;

                /* TODO check FST handling */

                udccs = readl(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))
                                writel(tmp, ep->reg_udccs);
                        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))
                                writel(tmp, ep->reg_udccs);

                        /* 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);
}

/*
 *      pxa25x_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 struct pxa25x_udc memory;
static int
pxa25x_udc_irq(void)
{
        struct pxa25x_udc *dev = &memory;
        int handled;

        test_watchdog(dev);

        dev->stats.irqs++;
        do {
                u32 udccr = readl(&dev->regs->udccr);

                handled = 0;

                /* SUSpend Interrupt Request */
                if (unlikely(udccr & UDCCR_SUSIR)) {
                        udc_ack_int_UDCCR(UDCCR_SUSIR);
                        handled = 1;
                        debug("USB suspend\n");

                        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;
                        debug("USB resume\n");

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

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

                        if ((readl(&dev->regs->udccr) & UDCCR_UDA) == 0) {
                                debug("USB reset start\n");

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

                        } else {
                                debug("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 uicr0 = readl(&dev->regs->uicr0);
                        u32 uicr1 = readl(&dev->regs->uicr1);
                        u32 usir0 = readl(&dev->regs->usir0);
                        u32 usir1 = readl(&dev->regs->usir1);

                        usir0 = usir0 & ~uicr0;
                        usir1 = usir1 & ~uicr1;
                        int i;

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

                        debug_cond(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]);
                                        setbits_le32(&dev->regs->usir0, tmp);
                                        handled = 1;
                                }
#ifndef CONFIG_USB_PXA25X_SMALL
                                if (usir1 & tmp) {
                                        handle_ep(&dev->ep[i+8]);
                                        setbits_le32(&dev->regs->usir1, tmp);
                                        handled = 1;
                                }
#endif
                        }
                }

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

        } while (handled);
        return IRQ_HANDLED;
}

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

/*
 * 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 pxa25x_udc memory = {
        .regs = UDC_REGS,

        .gadget = {
                .ops            = &pxa25x_udc_ops,
                .ep0            = &memory.ep[0].ep,
                .name           = driver_name,
        },

        /* control endpoint */
        .ep[0] = {
                .ep = {
                        .name           = ep0name,
                        .ops            = &pxa25x_ep_ops,
                        .maxpacket      = EP0_FIFO_SIZE,
                },
                .dev            = &memory,
                .reg_udccs      = &UDC_REGS->udccs[0],
                .reg_uddr       = &UDC_REGS->uddr0,
        },

        /* first group of endpoints */
        .ep[1] = {
                .ep = {
                        .name           = "ep1in-bulk",
                        .ops            = &pxa25x_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      = &UDC_REGS->udccs[1],
                .reg_uddr       = &UDC_REGS->uddr1,
        },
        .ep[2] = {
                .ep = {
                        .name           = "ep2out-bulk",
                        .ops            = &pxa25x_ep_ops,
                        .maxpacket      = BULK_FIFO_SIZE,
                },
                .dev            = &memory,
                .fifo_size      = BULK_FIFO_SIZE,
                .bEndpointAddress = 2,
                .bmAttributes   = USB_ENDPOINT_XFER_BULK,
                .reg_udccs      = &UDC_REGS->udccs[2],
                .reg_ubcr       = &UDC_REGS->ubcr2,
                .reg_uddr       = &UDC_REGS->uddr2,
        },
#ifndef CONFIG_USB_PXA25X_SMALL
        .ep[3] = {
                .ep = {
                        .name           = "ep3in-iso",
                        .ops            = &pxa25x_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      = &UDC_REGS->udccs[3],
                .reg_uddr       = &UDC_REGS->uddr3,
        },
        .ep[4] = {
                .ep = {
                        .name           = "ep4out-iso",
                        .ops            = &pxa25x_ep_ops,
                        .maxpacket      = ISO_FIFO_SIZE,
                },
                .dev            = &memory,
                .fifo_size      = ISO_FIFO_SIZE,
                .bEndpointAddress = 4,
                .bmAttributes   = USB_ENDPOINT_XFER_ISOC,
                .reg_udccs      = &UDC_REGS->udccs[4],
                .reg_ubcr       = &UDC_REGS->ubcr4,
                .reg_uddr       = &UDC_REGS->uddr4,
        },
        .ep[5] = {
                .ep = {
                        .name           = "ep5in-int",
                        .ops            = &pxa25x_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      = &UDC_REGS->udccs[5],
                .reg_uddr       = &UDC_REGS->uddr5,
        },

        /* second group of endpoints */
        .ep[6] = {
                .ep = {
                        .name           = "ep6in-bulk",
                        .ops            = &pxa25x_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      = &UDC_REGS->udccs[6],
                .reg_uddr       = &UDC_REGS->uddr6,
        },
        .ep[7] = {
                .ep = {
                        .name           = "ep7out-bulk",
                        .ops            = &pxa25x_ep_ops,
                        .maxpacket      = BULK_FIFO_SIZE,
                },
                .dev            = &memory,
                .fifo_size      = BULK_FIFO_SIZE,
                .bEndpointAddress = 7,
                .bmAttributes   = USB_ENDPOINT_XFER_BULK,
                .reg_udccs      = &UDC_REGS->udccs[7],
                .reg_ubcr       = &UDC_REGS->ubcr7,
                .reg_uddr       = &UDC_REGS->uddr7,
        },
        .ep[8] = {
                .ep = {
                        .name           = "ep8in-iso",
                        .ops            = &pxa25x_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      = &UDC_REGS->udccs[8],
                .reg_uddr       = &UDC_REGS->uddr8,
        },
        .ep[9] = {
                .ep = {
                        .name           = "ep9out-iso",
                        .ops            = &pxa25x_ep_ops,
                        .maxpacket      = ISO_FIFO_SIZE,
                },
                .dev            = &memory,
                .fifo_size      = ISO_FIFO_SIZE,
                .bEndpointAddress = 9,
                .bmAttributes   = USB_ENDPOINT_XFER_ISOC,
                .reg_udccs      = &UDC_REGS->udccs[9],
                .reg_ubcr       = &UDC_REGS->ubcr9,
                .reg_uddr       = &UDC_REGS->uddr9,
        },
        .ep[10] = {
                .ep = {
                        .name           = "ep10in-int",
                        .ops            = &pxa25x_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      = &UDC_REGS->udccs[10],
                .reg_uddr       = &UDC_REGS->uddr10,
        },

        /* third group of endpoints */
        .ep[11] = {
                .ep = {
                        .name           = "ep11in-bulk",
                        .ops            = &pxa25x_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      = &UDC_REGS->udccs[11],
                .reg_uddr       = &UDC_REGS->uddr11,
        },
        .ep[12] = {
                .ep = {
                        .name           = "ep12out-bulk",
                        .ops            = &pxa25x_ep_ops,
                        .maxpacket      = BULK_FIFO_SIZE,
                },
                .dev            = &memory,
                .fifo_size      = BULK_FIFO_SIZE,
                .bEndpointAddress = 12,
                .bmAttributes   = USB_ENDPOINT_XFER_BULK,
                .reg_udccs      = &UDC_REGS->udccs[12],
                .reg_ubcr       = &UDC_REGS->ubcr12,
                .reg_uddr       = &UDC_REGS->uddr12,
        },
        .ep[13] = {
                .ep = {
                        .name           = "ep13in-iso",
                        .ops            = &pxa25x_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      = &UDC_REGS->udccs[13],
                .reg_uddr       = &UDC_REGS->uddr13,
        },
        .ep[14] = {
                .ep = {
                        .name           = "ep14out-iso",
                        .ops            = &pxa25x_ep_ops,
                        .maxpacket      = ISO_FIFO_SIZE,
                },
                .dev            = &memory,
                .fifo_size      = ISO_FIFO_SIZE,
                .bEndpointAddress = 14,
                .bmAttributes   = USB_ENDPOINT_XFER_ISOC,
                .reg_udccs      = &UDC_REGS->udccs[14],
                .reg_ubcr       = &UDC_REGS->ubcr14,
                .reg_uddr       = &UDC_REGS->uddr14,
        },
        .ep[15] = {
                .ep = {
                        .name           = "ep15in-int",
                        .ops            = &pxa25x_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      = &UDC_REGS->udccs[15],
                .reg_uddr       = &UDC_REGS->uddr15,
        },
#endif /* !CONFIG_USB_PXA25X_SMALL */
};

static void udc_command(int cmd)
{
        switch (cmd) {
        case PXA2XX_UDC_CMD_CONNECT:
                setbits_le32(GPDR(CONFIG_USB_DEV_PULLUP_GPIO),
                        GPIO_bit(CONFIG_USB_DEV_PULLUP_GPIO));

                /* enable pullup */
                writel(GPIO_bit(CONFIG_USB_DEV_PULLUP_GPIO),
                        GPCR(CONFIG_USB_DEV_PULLUP_GPIO));

                debug("Connected to USB\n");
                break;

        case PXA2XX_UDC_CMD_DISCONNECT:
                /* disable pullup resistor */
                writel(GPIO_bit(CONFIG_USB_DEV_PULLUP_GPIO),
                        GPSR(CONFIG_USB_DEV_PULLUP_GPIO));

                /* setup pin as input, line will float */
                clrbits_le32(GPDR(CONFIG_USB_DEV_PULLUP_GPIO),
                        GPIO_bit(CONFIG_USB_DEV_PULLUP_GPIO));

                debug("Disconnected from USB\n");
                break;
        }
}

static struct pxa2xx_udc_mach_info mach_info = {
        .udc_command = udc_command,
};

/*
 * 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 pxa25x_udc *dev = &memory;
        int retval;
        uint32_t chiprev;

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

        /* Enable clock for usb controller */
        setbits_le32(CKEN, CKEN11_USB);

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

        /* trigger chiprev-specific logic */
        switch ((chiprev = pxa_get_cpu_revision())) {
        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;
        default:
                printf("%s: unrecognized processor: %08x\n",
                        DRIVER_NAME, chiprev);
                return -ENODEV;
        }

        the_controller = dev;

        /* prepare watchdog timer */
        dev->watchdog.running = 0;
        dev->watchdog.period = 5000 * CONFIG_SYS_HZ / 1000000; /* 5 ms */
        dev->watchdog.function = udc_watchdog;

        udc_disable(dev);
        udc_reinit(dev);

        dev->mach = &mach_info;

        dev->gadget.name = "pxa2xx_udc";
        retval = driver->bind(&dev->gadget);
        if (retval) {
                printf("bind to driver %s --> error %d\n",
                                DRIVER_NAME, retval);
                dev->driver = NULL;
                return retval;
        }

        /*
         * ... then enable host detection and ep0; and we're ready
         * for set_configuration as well as eventual disconnect.
         */
        printf("registered gadget driver '%s'\n", DRIVER_NAME);

        pullup(dev);
        dump_state(dev);
        return 0;
}

static void
stop_activity(struct pxa25x_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 pxa25x_ep *ep = &dev->ep[i];

                ep->stopped = 1;
                nuke(ep, -ESHUTDOWN);
        }
        stop_watchdog(dev);

        /* 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 pxa25x_udc       *dev = the_controller;

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

        local_irq_disable();
        dev->pullup = 0;
        pullup(dev);
        stop_activity(dev, driver);
        local_irq_enable();

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

        printf("unregistered gadget driver '%s'\n", DRIVER_NAME);
        dump_state(dev);

        the_controller = NULL;

        clrbits_le32(CKEN, CKEN11_USB);

        return 0;
}

extern void udc_disconnect(void)
{
        setbits_le32(CKEN, CKEN11_USB);
        udc_clear_mask_UDCCR(UDCCR_UDE);
        udc_command(PXA2XX_UDC_CMD_DISCONNECT);
        clrbits_le32(CKEN, CKEN11_USB);
}

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

extern int
usb_gadget_handle_interrupts(void)
{
        return pxa25x_udc_irq();
}