// SPDX-License-Identifier: GPL-2.0+
/*
 * amd5536.c -- AMD 5536 UDC high/full speed USB device controller
 *
 * Copyright (C) 2005-2007 AMD (http://www.amd.com)
 * Author: Thomas Dahlmann
 */

/*
 * This file does the core driver implementation for the UDC that is based
 * on Synopsys device controller IP (different than HS OTG IP) that is either
 * connected through PCI bus or integrated to SoC platforms.
 */

/* Driver strings */
#define UDC_MOD_DESCRIPTION             "Synopsys USB Device Controller"
#define UDC_DRIVER_VERSION_STRING       "01.00.0206"

#include <linux/module.h>
#include <linux/pci.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/ioport.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/timer.h>
#include <linux/list.h>
#include <linux/interrupt.h>
#include <linux/ioctl.h>
#include <linux/fs.h>
#include <linux/dmapool.h>
#include <linux/prefetch.h>
#include <linux/moduleparam.h>
#include <asm/byteorder.h>
#include <asm/unaligned.h>
#include "amd5536udc.h"

static void udc_tasklet_disconnect(unsigned long);
static void udc_setup_endpoints(struct udc *dev);
static void udc_soft_reset(struct udc *dev);
static struct udc_request *udc_alloc_bna_dummy(struct udc_ep *ep);
static void udc_free_request(struct usb_ep *usbep, struct usb_request *usbreq);

/* description */
static const char mod_desc[] = UDC_MOD_DESCRIPTION;
static const char name[] = "udc";

/* structure to hold endpoint function pointers */
static const struct usb_ep_ops udc_ep_ops;

/* received setup data */
static union udc_setup_data setup_data;

/* pointer to device object */
static struct udc *udc;

/* irq spin lock for soft reset */
static DEFINE_SPINLOCK(udc_irq_spinlock);
/* stall spin lock */
static DEFINE_SPINLOCK(udc_stall_spinlock);

/*
* slave mode: pending bytes in rx fifo after nyet,
* used if EPIN irq came but no req was available
*/
static unsigned int udc_rxfifo_pending;

/* count soft resets after suspend to avoid loop */
static int soft_reset_occured;
static int soft_reset_after_usbreset_occured;

/* timer */
static struct timer_list udc_timer;
static int stop_timer;

/* set_rde -- Is used to control enabling of RX DMA. Problem is
 * that UDC has only one bit (RDE) to enable/disable RX DMA for
 * all OUT endpoints. So we have to handle race conditions like
 * when OUT data reaches the fifo but no request was queued yet.
 * This cannot be solved by letting the RX DMA disabled until a
 * request gets queued because there may be other OUT packets
 * in the FIFO (important for not blocking control traffic).
 * The value of set_rde controls the correspondig timer.
 *
 * set_rde -1 == not used, means it is alloed to be set to 0 or 1
 * set_rde  0 == do not touch RDE, do no start the RDE timer
 * set_rde  1 == timer function will look whether FIFO has data
 * set_rde  2 == set by timer function to enable RX DMA on next call
 */
static int set_rde = -1;

static DECLARE_COMPLETION(on_exit);
static struct timer_list udc_pollstall_timer;
static int stop_pollstall_timer;
static DECLARE_COMPLETION(on_pollstall_exit);

/* tasklet for usb disconnect */
static DECLARE_TASKLET(disconnect_tasklet, udc_tasklet_disconnect,
                (unsigned long) &udc);


/* endpoint names used for print */
static const char ep0_string[] = "ep0in";
static const struct {
        const char *name;
        const struct usb_ep_caps caps;
} ep_info[] = {
#define EP_INFO(_name, _caps) \
        { \
                .name = _name, \
                .caps = _caps, \
        }

        EP_INFO(ep0_string,
                USB_EP_CAPS(USB_EP_CAPS_TYPE_CONTROL, USB_EP_CAPS_DIR_IN)),
        EP_INFO("ep1in-int",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_IN)),
        EP_INFO("ep2in-bulk",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_IN)),
        EP_INFO("ep3in-bulk",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_IN)),
        EP_INFO("ep4in-bulk",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_IN)),
        EP_INFO("ep5in-bulk",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_IN)),
        EP_INFO("ep6in-bulk",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_IN)),
        EP_INFO("ep7in-bulk",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_IN)),
        EP_INFO("ep8in-bulk",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_IN)),
        EP_INFO("ep9in-bulk",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_IN)),
        EP_INFO("ep10in-bulk",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_IN)),
        EP_INFO("ep11in-bulk",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_IN)),
        EP_INFO("ep12in-bulk",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_IN)),
        EP_INFO("ep13in-bulk",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_IN)),
        EP_INFO("ep14in-bulk",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_IN)),
        EP_INFO("ep15in-bulk",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_IN)),
        EP_INFO("ep0out",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_CONTROL, USB_EP_CAPS_DIR_OUT)),
        EP_INFO("ep1out-bulk",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_OUT)),
        EP_INFO("ep2out-bulk",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_OUT)),
        EP_INFO("ep3out-bulk",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_OUT)),
        EP_INFO("ep4out-bulk",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_OUT)),
        EP_INFO("ep5out-bulk",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_OUT)),
        EP_INFO("ep6out-bulk",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_OUT)),
        EP_INFO("ep7out-bulk",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_OUT)),
        EP_INFO("ep8out-bulk",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_OUT)),
        EP_INFO("ep9out-bulk",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_OUT)),
        EP_INFO("ep10out-bulk",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_OUT)),
        EP_INFO("ep11out-bulk",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_OUT)),
        EP_INFO("ep12out-bulk",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_OUT)),
        EP_INFO("ep13out-bulk",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_OUT)),
        EP_INFO("ep14out-bulk",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_OUT)),
        EP_INFO("ep15out-bulk",
                USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_OUT)),

#undef EP_INFO
};

/* buffer fill mode */
static int use_dma_bufferfill_mode;
/* tx buffer size for high speed */
static unsigned long hs_tx_buf = UDC_EPIN_BUFF_SIZE;

/*---------------------------------------------------------------------------*/
/* Prints UDC device registers and endpoint irq registers */
static void print_regs(struct udc *dev)
{
        DBG(dev, "------- Device registers -------\n");
        DBG(dev, "dev config     = %08x\n", readl(&dev->regs->cfg));
        DBG(dev, "dev control    = %08x\n", readl(&dev->regs->ctl));
        DBG(dev, "dev status     = %08x\n", readl(&dev->regs->sts));
        DBG(dev, "\n");
        DBG(dev, "dev int's      = %08x\n", readl(&dev->regs->irqsts));
        DBG(dev, "dev intmask    = %08x\n", readl(&dev->regs->irqmsk));
        DBG(dev, "\n");
        DBG(dev, "dev ep int's   = %08x\n", readl(&dev->regs->ep_irqsts));
        DBG(dev, "dev ep intmask = %08x\n", readl(&dev->regs->ep_irqmsk));
        DBG(dev, "\n");
        DBG(dev, "USE DMA        = %d\n", use_dma);
        if (use_dma && use_dma_ppb && !use_dma_ppb_du) {
                DBG(dev, "DMA mode       = PPBNDU (packet per buffer "
                        "WITHOUT desc. update)\n");
                dev_info(dev->dev, "DMA mode (%s)\n", "PPBNDU");
        } else if (use_dma && use_dma_ppb && use_dma_ppb_du) {
                DBG(dev, "DMA mode       = PPBDU (packet per buffer "
                        "WITH desc. update)\n");
                dev_info(dev->dev, "DMA mode (%s)\n", "PPBDU");
        }
        if (use_dma && use_dma_bufferfill_mode) {
                DBG(dev, "DMA mode       = BF (buffer fill mode)\n");
                dev_info(dev->dev, "DMA mode (%s)\n", "BF");
        }
        if (!use_dma)
                dev_info(dev->dev, "FIFO mode\n");
        DBG(dev, "-------------------------------------------------------\n");
}

/* Masks unused interrupts */
int udc_mask_unused_interrupts(struct udc *dev)
{
        u32 tmp;

        /* mask all dev interrupts */
        tmp =   AMD_BIT(UDC_DEVINT_SVC) |
                AMD_BIT(UDC_DEVINT_ENUM) |
                AMD_BIT(UDC_DEVINT_US) |
                AMD_BIT(UDC_DEVINT_UR) |
                AMD_BIT(UDC_DEVINT_ES) |
                AMD_BIT(UDC_DEVINT_SI) |
                AMD_BIT(UDC_DEVINT_SOF)|
                AMD_BIT(UDC_DEVINT_SC);
        writel(tmp, &dev->regs->irqmsk);

        /* mask all ep interrupts */
        writel(UDC_EPINT_MSK_DISABLE_ALL, &dev->regs->ep_irqmsk);

        return 0;
}
EXPORT_SYMBOL_GPL(udc_mask_unused_interrupts);

/* Enables endpoint 0 interrupts */
static int udc_enable_ep0_interrupts(struct udc *dev)
{
        u32 tmp;

        DBG(dev, "udc_enable_ep0_interrupts()\n");

        /* read irq mask */
        tmp = readl(&dev->regs->ep_irqmsk);
        /* enable ep0 irq's */
        tmp &= AMD_UNMASK_BIT(UDC_EPINT_IN_EP0)
                & AMD_UNMASK_BIT(UDC_EPINT_OUT_EP0);
        writel(tmp, &dev->regs->ep_irqmsk);

        return 0;
}

/* Enables device interrupts for SET_INTF and SET_CONFIG */
int udc_enable_dev_setup_interrupts(struct udc *dev)
{
        u32 tmp;

        DBG(dev, "enable device interrupts for setup data\n");

        /* read irq mask */
        tmp = readl(&dev->regs->irqmsk);

        /* enable SET_INTERFACE, SET_CONFIG and other needed irq's */
        tmp &= AMD_UNMASK_BIT(UDC_DEVINT_SI)
                & AMD_UNMASK_BIT(UDC_DEVINT_SC)
                & AMD_UNMASK_BIT(UDC_DEVINT_UR)
                & AMD_UNMASK_BIT(UDC_DEVINT_SVC)
                & AMD_UNMASK_BIT(UDC_DEVINT_ENUM);
        writel(tmp, &dev->regs->irqmsk);

        return 0;
}
EXPORT_SYMBOL_GPL(udc_enable_dev_setup_interrupts);

/* Calculates fifo start of endpoint based on preceding endpoints */
static int udc_set_txfifo_addr(struct udc_ep *ep)
{
        struct udc      *dev;
        u32 tmp;
        int i;

        if (!ep || !(ep->in))
                return -EINVAL;

        dev = ep->dev;
        ep->txfifo = dev->txfifo;

        /* traverse ep's */
        for (i = 0; i < ep->num; i++) {
                if (dev->ep[i].regs) {
                        /* read fifo size */
                        tmp = readl(&dev->ep[i].regs->bufin_framenum);
                        tmp = AMD_GETBITS(tmp, UDC_EPIN_BUFF_SIZE);
                        ep->txfifo += tmp;
                }
        }
        return 0;
}

/* CNAK pending field: bit0 = ep0in, bit16 = ep0out */
static u32 cnak_pending;

static void UDC_QUEUE_CNAK(struct udc_ep *ep, unsigned num)
{
        if (readl(&ep->regs->ctl) & AMD_BIT(UDC_EPCTL_NAK)) {
                DBG(ep->dev, "NAK could not be cleared for ep%d\n", num);
                cnak_pending |= 1 << (num);
                ep->naking = 1;
        } else
                cnak_pending = cnak_pending & (~(1 << (num)));
}


/* Enables endpoint, is called by gadget driver */
static int
udc_ep_enable(struct usb_ep *usbep, const struct usb_endpoint_descriptor *desc)
{
        struct udc_ep           *ep;
        struct udc              *dev;
        u32                     tmp;
        unsigned long           iflags;
        u8 udc_csr_epix;
        unsigned                maxpacket;

        if (!usbep
                        || usbep->name == ep0_string
                        || !desc
                        || desc->bDescriptorType != USB_DT_ENDPOINT)
                return -EINVAL;

        ep = container_of(usbep, struct udc_ep, ep);
        dev = ep->dev;

        DBG(dev, "udc_ep_enable() ep %d\n", ep->num);

        if (!dev->driver || dev->gadget.speed == USB_SPEED_UNKNOWN)
                return -ESHUTDOWN;

        spin_lock_irqsave(&dev->lock, iflags);
        ep->ep.desc = desc;

        ep->halted = 0;

        /* set traffic type */
        tmp = readl(&dev->ep[ep->num].regs->ctl);
        tmp = AMD_ADDBITS(tmp, desc->bmAttributes, UDC_EPCTL_ET);
        writel(tmp, &dev->ep[ep->num].regs->ctl);

        /* set max packet size */
        maxpacket = usb_endpoint_maxp(desc);
        tmp = readl(&dev->ep[ep->num].regs->bufout_maxpkt);
        tmp = AMD_ADDBITS(tmp, maxpacket, UDC_EP_MAX_PKT_SIZE);
        ep->ep.maxpacket = maxpacket;
        writel(tmp, &dev->ep[ep->num].regs->bufout_maxpkt);

        /* IN ep */
        if (ep->in) {

                /* ep ix in UDC CSR register space */
                udc_csr_epix = ep->num;

                /* set buffer size (tx fifo entries) */
                tmp = readl(&dev->ep[ep->num].regs->bufin_framenum);
                /* double buffering: fifo size = 2 x max packet size */
                tmp = AMD_ADDBITS(
                                tmp,
                                maxpacket * UDC_EPIN_BUFF_SIZE_MULT
                                          / UDC_DWORD_BYTES,
                                UDC_EPIN_BUFF_SIZE);
                writel(tmp, &dev->ep[ep->num].regs->bufin_framenum);

                /* calc. tx fifo base addr */
                udc_set_txfifo_addr(ep);

                /* flush fifo */
                tmp = readl(&ep->regs->ctl);
                tmp |= AMD_BIT(UDC_EPCTL_F);
                writel(tmp, &ep->regs->ctl);

        /* OUT ep */
        } else {
                /* ep ix in UDC CSR register space */
                udc_csr_epix = ep->num - UDC_CSR_EP_OUT_IX_OFS;

                /* set max packet size UDC CSR  */
                tmp = readl(&dev->csr->ne[ep->num - UDC_CSR_EP_OUT_IX_OFS]);
                tmp = AMD_ADDBITS(tmp, maxpacket,
                                        UDC_CSR_NE_MAX_PKT);
                writel(tmp, &dev->csr->ne[ep->num - UDC_CSR_EP_OUT_IX_OFS]);

                if (use_dma && !ep->in) {
                        /* alloc and init BNA dummy request */
                        ep->bna_dummy_req = udc_alloc_bna_dummy(ep);
                        ep->bna_occurred = 0;
                }

                if (ep->num != UDC_EP0OUT_IX)
                        dev->data_ep_enabled = 1;
        }

        /* set ep values */
        tmp = readl(&dev->csr->ne[udc_csr_epix]);
        /* max packet */
        tmp = AMD_ADDBITS(tmp, maxpacket, UDC_CSR_NE_MAX_PKT);
        /* ep number */
        tmp = AMD_ADDBITS(tmp, desc->bEndpointAddress, UDC_CSR_NE_NUM);
        /* ep direction */
        tmp = AMD_ADDBITS(tmp, ep->in, UDC_CSR_NE_DIR);
        /* ep type */
        tmp = AMD_ADDBITS(tmp, desc->bmAttributes, UDC_CSR_NE_TYPE);
        /* ep config */
        tmp = AMD_ADDBITS(tmp, ep->dev->cur_config, UDC_CSR_NE_CFG);
        /* ep interface */
        tmp = AMD_ADDBITS(tmp, ep->dev->cur_intf, UDC_CSR_NE_INTF);
        /* ep alt */
        tmp = AMD_ADDBITS(tmp, ep->dev->cur_alt, UDC_CSR_NE_ALT);
        /* write reg */
        writel(tmp, &dev->csr->ne[udc_csr_epix]);

        /* enable ep irq */
        tmp = readl(&dev->regs->ep_irqmsk);
        tmp &= AMD_UNMASK_BIT(ep->num);
        writel(tmp, &dev->regs->ep_irqmsk);

        /*
         * clear NAK by writing CNAK
         * avoid BNA for OUT DMA, don't clear NAK until DMA desc. written
         */
        if (!use_dma || ep->in) {
                tmp = readl(&ep->regs->ctl);
                tmp |= AMD_BIT(UDC_EPCTL_CNAK);
                writel(tmp, &ep->regs->ctl);
                ep->naking = 0;
                UDC_QUEUE_CNAK(ep, ep->num);
        }
        tmp = desc->bEndpointAddress;
        DBG(dev, "%s enabled\n", usbep->name);

        spin_unlock_irqrestore(&dev->lock, iflags);
        return 0;
}

/* Resets endpoint */
static void ep_init(struct udc_regs __iomem *regs, struct udc_ep *ep)
{
        u32             tmp;

        VDBG(ep->dev, "ep-%d reset\n", ep->num);
        ep->ep.desc = NULL;
        ep->ep.ops = &udc_ep_ops;
        INIT_LIST_HEAD(&ep->queue);

        usb_ep_set_maxpacket_limit(&ep->ep,(u16) ~0);
        /* set NAK */
        tmp = readl(&ep->regs->ctl);
        tmp |= AMD_BIT(UDC_EPCTL_SNAK);
        writel(tmp, &ep->regs->ctl);
        ep->naking = 1;

        /* disable interrupt */
        tmp = readl(&regs->ep_irqmsk);
        tmp |= AMD_BIT(ep->num);
        writel(tmp, &regs->ep_irqmsk);

        if (ep->in) {
                /* unset P and IN bit of potential former DMA */
                tmp = readl(&ep->regs->ctl);
                tmp &= AMD_UNMASK_BIT(UDC_EPCTL_P);
                writel(tmp, &ep->regs->ctl);

                tmp = readl(&ep->regs->sts);
                tmp |= AMD_BIT(UDC_EPSTS_IN);
                writel(tmp, &ep->regs->sts);

                /* flush the fifo */
                tmp = readl(&ep->regs->ctl);
                tmp |= AMD_BIT(UDC_EPCTL_F);
                writel(tmp, &ep->regs->ctl);

        }
        /* reset desc pointer */
        writel(0, &ep->regs->desptr);
}

/* Disables endpoint, is called by gadget driver */
static int udc_ep_disable(struct usb_ep *usbep)
{
        struct udc_ep   *ep = NULL;
        unsigned long   iflags;

        if (!usbep)
                return -EINVAL;

        ep = container_of(usbep, struct udc_ep, ep);
        if (usbep->name == ep0_string || !ep->ep.desc)
                return -EINVAL;

        DBG(ep->dev, "Disable ep-%d\n", ep->num);

        spin_lock_irqsave(&ep->dev->lock, iflags);
        udc_free_request(&ep->ep, &ep->bna_dummy_req->req);
        empty_req_queue(ep);
        ep_init(ep->dev->regs, ep);
        spin_unlock_irqrestore(&ep->dev->lock, iflags);

        return 0;
}

/* Allocates request packet, called by gadget driver */
static struct usb_request *
udc_alloc_request(struct usb_ep *usbep, gfp_t gfp)
{
        struct udc_request      *req;
        struct udc_data_dma     *dma_desc;
        struct udc_ep   *ep;

        if (!usbep)
                return NULL;

        ep = container_of(usbep, struct udc_ep, ep);

        VDBG(ep->dev, "udc_alloc_req(): ep%d\n", ep->num);
        req = kzalloc(sizeof(struct udc_request), gfp);
        if (!req)
                return NULL;

        req->req.dma = DMA_DONT_USE;
        INIT_LIST_HEAD(&req->queue);

        if (ep->dma) {
                /* ep0 in requests are allocated from data pool here */
                dma_desc = dma_pool_alloc(ep->dev->data_requests, gfp,
                                                &req->td_phys);
                if (!dma_desc) {
                        kfree(req);
                        return NULL;
                }

                VDBG(ep->dev, "udc_alloc_req: req = %p dma_desc = %p, "
                                "td_phys = %lx\n",
                                req, dma_desc,
                                (unsigned long)req->td_phys);
                /* prevent from using desc. - set HOST BUSY */
                dma_desc->status = AMD_ADDBITS(dma_desc->status,
                                                UDC_DMA_STP_STS_BS_HOST_BUSY,
                                                UDC_DMA_STP_STS_BS);
                dma_desc->bufptr = cpu_to_le32(DMA_DONT_USE);
                req->td_data = dma_desc;
                req->td_data_last = NULL;
                req->chain_len = 1;
        }

        return &req->req;
}

/* frees pci pool descriptors of a DMA chain */
static void udc_free_dma_chain(struct udc *dev, struct udc_request *req)
{
        struct udc_data_dma *td = req->td_data;
        unsigned int i;

        dma_addr_t addr_next = 0x00;
        dma_addr_t addr = (dma_addr_t)td->next;

        DBG(dev, "free chain req = %p\n", req);

        /* do not free first desc., will be done by free for request */
        for (i = 1; i < req->chain_len; i++) {
                td = phys_to_virt(addr);
                addr_next = (dma_addr_t)td->next;
                dma_pool_free(dev->data_requests, td, addr);
                addr = addr_next;
        }
}

/* Frees request packet, called by gadget driver */
static void
udc_free_request(struct usb_ep *usbep, struct usb_request *usbreq)
{
        struct udc_ep   *ep;
        struct udc_request      *req;

        if (!usbep || !usbreq)
                return;

        ep = container_of(usbep, struct udc_ep, ep);
        req = container_of(usbreq, struct udc_request, req);
        VDBG(ep->dev, "free_req req=%p\n", req);
        BUG_ON(!list_empty(&req->queue));
        if (req->td_data) {
                VDBG(ep->dev, "req->td_data=%p\n", req->td_data);

                /* free dma chain if created */
                if (req->chain_len > 1)
                        udc_free_dma_chain(ep->dev, req);

                dma_pool_free(ep->dev->data_requests, req->td_data,
                                                        req->td_phys);
        }
        kfree(req);
}

/* Init BNA dummy descriptor for HOST BUSY and pointing to itself */
static void udc_init_bna_dummy(struct udc_request *req)
{
        if (req) {
                /* set last bit */
                req->td_data->status |= AMD_BIT(UDC_DMA_IN_STS_L);
                /* set next pointer to itself */
                req->td_data->next = req->td_phys;
                /* set HOST BUSY */
                req->td_data->status
                        = AMD_ADDBITS(req->td_data->status,
                                        UDC_DMA_STP_STS_BS_DMA_DONE,
                                        UDC_DMA_STP_STS_BS);
#ifdef UDC_VERBOSE
                pr_debug("bna desc = %p, sts = %08x\n",
                        req->td_data, req->td_data->status);
#endif
        }
}

/* Allocate BNA dummy descriptor */
static struct udc_request *udc_alloc_bna_dummy(struct udc_ep *ep)
{
        struct udc_request *req = NULL;
        struct usb_request *_req = NULL;

        /* alloc the dummy request */
        _req = udc_alloc_request(&ep->ep, GFP_ATOMIC);
        if (_req) {
                req = container_of(_req, struct udc_request, req);
                ep->bna_dummy_req = req;
                udc_init_bna_dummy(req);
        }
        return req;
}

/* Write data to TX fifo for IN packets */
static void
udc_txfifo_write(struct udc_ep *ep, struct usb_request *req)
{
        u8                      *req_buf;
        u32                     *buf;
        int                     i, j;
        unsigned                bytes = 0;
        unsigned                remaining = 0;

        if (!req || !ep)
                return;

        req_buf = req->buf + req->actual;
        prefetch(req_buf);
        remaining = req->length - req->actual;

        buf = (u32 *) req_buf;

        bytes = ep->ep.maxpacket;
        if (bytes > remaining)
                bytes = remaining;

        /* dwords first */
        for (i = 0; i < bytes / UDC_DWORD_BYTES; i++)
                writel(*(buf + i), ep->txfifo);

        /* remaining bytes must be written by byte access */
        for (j = 0; j < bytes % UDC_DWORD_BYTES; j++) {
                writeb((u8)(*(buf + i) >> (j << UDC_BITS_PER_BYTE_SHIFT)),
                                                        ep->txfifo);
        }

        /* dummy write confirm */
        writel(0, &ep->regs->confirm);
}

/* Read dwords from RX fifo for OUT transfers */
static int udc_rxfifo_read_dwords(struct udc *dev, u32 *buf, int dwords)
{
        int i;

        VDBG(dev, "udc_read_dwords(): %d dwords\n", dwords);

        for (i = 0; i < dwords; i++)
                *(buf + i) = readl(dev->rxfifo);
        return 0;
}

/* Read bytes from RX fifo for OUT transfers */
static int udc_rxfifo_read_bytes(struct udc *dev, u8 *buf, int bytes)
{
        int i, j;
        u32 tmp;

        VDBG(dev, "udc_read_bytes(): %d bytes\n", bytes);

        /* dwords first */
        for (i = 0; i < bytes / UDC_DWORD_BYTES; i++)
                *((u32 *)(buf + (i<<2))) = readl(dev->rxfifo);

        /* remaining bytes must be read by byte access */
        if (bytes % UDC_DWORD_BYTES) {
                tmp = readl(dev->rxfifo);
                for (j = 0; j < bytes % UDC_DWORD_BYTES; j++) {
                        *(buf + (i<<2) + j) = (u8)(tmp & UDC_BYTE_MASK);
                        tmp = tmp >> UDC_BITS_PER_BYTE;
                }
        }

        return 0;
}

/* Read data from RX fifo for OUT transfers */
static int
udc_rxfifo_read(struct udc_ep *ep, struct udc_request *req)
{
        u8 *buf;
        unsigned buf_space;
        unsigned bytes = 0;
        unsigned finished = 0;

        /* received number bytes */
        bytes = readl(&ep->regs->sts);
        bytes = AMD_GETBITS(bytes, UDC_EPSTS_RX_PKT_SIZE);

        buf_space = req->req.length - req->req.actual;
        buf = req->req.buf + req->req.actual;
        if (bytes > buf_space) {
                if ((buf_space % ep->ep.maxpacket) != 0) {
                        DBG(ep->dev,
                                "%s: rx %d bytes, rx-buf space = %d bytesn\n",
                                ep->ep.name, bytes, buf_space);
                        req->req.status = -EOVERFLOW;
                }
                bytes = buf_space;
        }
        req->req.actual += bytes;

        /* last packet ? */
        if (((bytes % ep->ep.maxpacket) != 0) || (!bytes)
                || ((req->req.actual == req->req.length) && !req->req.zero))
                finished = 1;

        /* read rx fifo bytes */
        VDBG(ep->dev, "ep %s: rxfifo read %d bytes\n", ep->ep.name, bytes);
        udc_rxfifo_read_bytes(ep->dev, buf, bytes);

        return finished;
}

/* Creates or re-inits a DMA chain */
static int udc_create_dma_chain(
        struct udc_ep *ep,
        struct udc_request *req,
        unsigned long buf_len, gfp_t gfp_flags
)
{
        unsigned long bytes = req->req.length;
        unsigned int i;
        dma_addr_t dma_addr;
        struct udc_data_dma     *td = NULL;
        struct udc_data_dma     *last = NULL;
        unsigned long txbytes;
        unsigned create_new_chain = 0;
        unsigned len;

        VDBG(ep->dev, "udc_create_dma_chain: bytes=%ld buf_len=%ld\n",
             bytes, buf_len);
        dma_addr = DMA_DONT_USE;

        /* unset L bit in first desc for OUT */
        if (!ep->in)
                req->td_data->status &= AMD_CLEAR_BIT(UDC_DMA_IN_STS_L);

        /* alloc only new desc's if not already available */
        len = req->req.length / ep->ep.maxpacket;
        if (req->req.length % ep->ep.maxpacket)
                len++;

        if (len > req->chain_len) {
                /* shorter chain already allocated before */
                if (req->chain_len > 1)
                        udc_free_dma_chain(ep->dev, req);
                req->chain_len = len;
                create_new_chain = 1;
        }

        td = req->td_data;
        /* gen. required number of descriptors and buffers */
        for (i = buf_len; i < bytes; i += buf_len) {
                /* create or determine next desc. */
                if (create_new_chain) {
                        td = dma_pool_alloc(ep->dev->data_requests,
                                            gfp_flags, &dma_addr);
                        if (!td)
                                return -ENOMEM;

                        td->status = 0;
                } else if (i == buf_len) {
                        /* first td */
                        td = (struct udc_data_dma *)phys_to_virt(
                                                req->td_data->next);
                        td->status = 0;
                } else {
                        td = (struct udc_data_dma *)phys_to_virt(last->next);
                        td->status = 0;
                }

                if (td)
                        td->bufptr = req->req.dma + i; /* assign buffer */
                else
                        break;

                /* short packet ? */
                if ((bytes - i) >= buf_len) {
                        txbytes = buf_len;
                } else {
                        /* short packet */
                        txbytes = bytes - i;
                }

                /* link td and assign tx bytes */
                if (i == buf_len) {
                        if (create_new_chain)
                                req->td_data->next = dma_addr;
                        /*
                         * else
                         *      req->td_data->next = virt_to_phys(td);
                         */
                        /* write tx bytes */
                        if (ep->in) {
                                /* first desc */
                                req->td_data->status =
                                        AMD_ADDBITS(req->td_data->status,
                                                    ep->ep.maxpacket,
                                                    UDC_DMA_IN_STS_TXBYTES);
                                /* second desc */
                                td->status = AMD_ADDBITS(td->status,
                                                        txbytes,
                                                        UDC_DMA_IN_STS_TXBYTES);
                        }
                } else {
                        if (create_new_chain)
                                last->next = dma_addr;
                        /*
                         * else
                         *      last->next = virt_to_phys(td);
                         */
                        if (ep->in) {
                                /* write tx bytes */
                                td->status = AMD_ADDBITS(td->status,
                                                        txbytes,
                                                        UDC_DMA_IN_STS_TXBYTES);
                        }
                }
                last = td;
        }
        /* set last bit */
        if (td) {
                td->status |= AMD_BIT(UDC_DMA_IN_STS_L);
                /* last desc. points to itself */
                req->td_data_last = td;
        }

        return 0;
}

/* create/re-init a DMA descriptor or a DMA descriptor chain */
static int prep_dma(struct udc_ep *ep, struct udc_request *req, gfp_t gfp)
{
        int     retval = 0;
        u32     tmp;

        VDBG(ep->dev, "prep_dma\n");
        VDBG(ep->dev, "prep_dma ep%d req->td_data=%p\n",
                        ep->num, req->td_data);

        /* set buffer pointer */
        req->td_data->bufptr = req->req.dma;

        /* set last bit */
        req->td_data->status |= AMD_BIT(UDC_DMA_IN_STS_L);

        /* build/re-init dma chain if maxpkt scatter mode, not for EP0 */
        if (use_dma_ppb) {

                retval = udc_create_dma_chain(ep, req, ep->ep.maxpacket, gfp);
                if (retval != 0) {
                        if (retval == -ENOMEM)
                                DBG(ep->dev, "Out of DMA memory\n");
                        return retval;
                }
                if (ep->in) {
                        if (req->req.length == ep->ep.maxpacket) {
                                /* write tx bytes */
                                req->td_data->status =
                                        AMD_ADDBITS(req->td_data->status,
                                                ep->ep.maxpacket,
                                                UDC_DMA_IN_STS_TXBYTES);

                        }
                }

        }

        if (ep->in) {
                VDBG(ep->dev, "IN: use_dma_ppb=%d req->req.len=%d "
                                "maxpacket=%d ep%d\n",
                                use_dma_ppb, req->req.length,
                                ep->ep.maxpacket, ep->num);
                /*
                 * if bytes < max packet then tx bytes must
                 * be written in packet per buffer mode
                 */
                if (!use_dma_ppb || req->req.length < ep->ep.maxpacket
                                || ep->num == UDC_EP0OUT_IX
                                || ep->num == UDC_EP0IN_IX) {
                        /* write tx bytes */
                        req->td_data->status =
                                AMD_ADDBITS(req->td_data->status,
                                                req->req.length,
                                                UDC_DMA_IN_STS_TXBYTES);
                        /* reset frame num */
                        req->td_data->status =
                                AMD_ADDBITS(req->td_data->status,
                                                0,
                                                UDC_DMA_IN_STS_FRAMENUM);
                }
                /* set HOST BUSY */
                req->td_data->status =
                        AMD_ADDBITS(req->td_data->status,
                                UDC_DMA_STP_STS_BS_HOST_BUSY,
                                UDC_DMA_STP_STS_BS);
        } else {
                VDBG(ep->dev, "OUT set host ready\n");
                /* set HOST READY */
                req->td_data->status =
                        AMD_ADDBITS(req->td_data->status,
                                UDC_DMA_STP_STS_BS_HOST_READY,
                                UDC_DMA_STP_STS_BS);


                        /* clear NAK by writing CNAK */
                        if (ep->naking) {
                                tmp = readl(&ep->regs->ctl);
                                tmp |= AMD_BIT(UDC_EPCTL_CNAK);
                                writel(tmp, &ep->regs->ctl);
                                ep->naking = 0;
                                UDC_QUEUE_CNAK(ep, ep->num);
                        }

        }

        return retval;
}

/* Completes request packet ... caller MUST hold lock */
static void
complete_req(struct udc_ep *ep, struct udc_request *req, int sts)
__releases(ep->dev->lock)
__acquires(ep->dev->lock)
{
        struct udc              *dev;
        unsigned                halted;

        VDBG(ep->dev, "complete_req(): ep%d\n", ep->num);

        dev = ep->dev;
        /* unmap DMA */
        if (ep->dma)
                usb_gadget_unmap_request(&dev->gadget, &req->req, ep->in);

        halted = ep->halted;
        ep->halted = 1;

        /* set new status if pending */
        if (req->req.status == -EINPROGRESS)
                req->req.status = sts;

        /* remove from ep queue */
        list_del_init(&req->queue);

        VDBG(ep->dev, "req %p => complete %d bytes at %s with sts %d\n",
                &req->req, req->req.length, ep->ep.name, sts);

        spin_unlock(&dev->lock);
        usb_gadget_giveback_request(&ep->ep, &req->req);
        spin_lock(&dev->lock);
        ep->halted = halted;
}

/* Iterates to the end of a DMA chain and returns last descriptor */

static struct udc_data_dma *udc_get_last_dma_desc(struct udc_request *req)
{
        struct udc_data_dma     *td;

        td = req->td_data;
        while (td && !(td->status & AMD_BIT(UDC_DMA_IN_STS_L)))
                td = phys_to_virt(td->next);

        return td;

}

/* Iterates to the end of a DMA chain and counts bytes received */
static u32 udc_get_ppbdu_rxbytes(struct udc_request *req)
{
        struct udc_data_dma     *td;
        u32 count;

        td = req->td_data;
        /* received number bytes */
        count = AMD_GETBITS(td->status, UDC_DMA_OUT_STS_RXBYTES);

        while (td && !(td->status & AMD_BIT(UDC_DMA_IN_STS_L))) {
                td = phys_to_virt(td->next);
                /* received number bytes */
                if (td) {
                        count += AMD_GETBITS(td->status,
                                UDC_DMA_OUT_STS_RXBYTES);
                }
        }

        return count;

}

/* Enabling RX DMA */
static void udc_set_rde(struct udc *dev)
{
        u32 tmp;

        VDBG(dev, "udc_set_rde()\n");
        /* stop RDE timer */
        if (timer_pending(&udc_timer)) {
                set_rde = 0;
                mod_timer(&udc_timer, jiffies - 1);
        }
        /* set RDE */
        tmp = readl(&dev->regs->ctl);
        tmp |= AMD_BIT(UDC_DEVCTL_RDE);
        writel(tmp, &dev->regs->ctl);
}

/* Queues a request packet, called by gadget driver */
static int
udc_queue(struct usb_ep *usbep, struct usb_request *usbreq, gfp_t gfp)
{
        int                     retval = 0;
        u8                      open_rxfifo = 0;
        unsigned long           iflags;
        struct udc_ep           *ep;
        struct udc_request      *req;
        struct udc              *dev;
        u32                     tmp;

        /* check the inputs */
        req = container_of(usbreq, struct udc_request, req);

        if (!usbep || !usbreq || !usbreq->complete || !usbreq->buf
                        || !list_empty(&req->queue))
                return -EINVAL;

        ep = container_of(usbep, struct udc_ep, ep);
        if (!ep->ep.desc && (ep->num != 0 && ep->num != UDC_EP0OUT_IX))
                return -EINVAL;

        VDBG(ep->dev, "udc_queue(): ep%d-in=%d\n", ep->num, ep->in);
        dev = ep->dev;

        if (!dev->driver || dev->gadget.speed == USB_SPEED_UNKNOWN)
                return -ESHUTDOWN;

        /* map dma (usually done before) */
        if (ep->dma) {
                VDBG(dev, "DMA map req %p\n", req);
                retval = usb_gadget_map_request(&udc->gadget, usbreq, ep->in);
                if (retval)
                        return retval;
        }

        VDBG(dev, "%s queue req %p, len %d req->td_data=%p buf %p\n",
                        usbep->name, usbreq, usbreq->length,
                        req->td_data, usbreq->buf);

        spin_lock_irqsave(&dev->lock, iflags);
        usbreq->actual = 0;
        usbreq->status = -EINPROGRESS;
        req->dma_done = 0;

        /* on empty queue just do first transfer */
        if (list_empty(&ep->queue)) {
                /* zlp */
                if (usbreq->length == 0) {
                        /* IN zlp's are handled by hardware */
                        complete_req(ep, req, 0);
                        VDBG(dev, "%s: zlp\n", ep->ep.name);
                        /*
                         * if set_config or set_intf is waiting for ack by zlp
                         * then set CSR_DONE
                         */
                        if (dev->set_cfg_not_acked) {
                                tmp = readl(&dev->regs->ctl);
                                tmp |= AMD_BIT(UDC_DEVCTL_CSR_DONE);
                                writel(tmp, &dev->regs->ctl);
                                dev->set_cfg_not_acked = 0;
                        }
                        /* setup command is ACK'ed now by zlp */
                        if (dev->waiting_zlp_ack_ep0in) {
                                /* clear NAK by writing CNAK in EP0_IN */
                                tmp = readl(&dev->ep[UDC_EP0IN_IX].regs->ctl);
                                tmp |= AMD_BIT(UDC_EPCTL_CNAK);
                                writel(tmp, &dev->ep[UDC_EP0IN_IX].regs->ctl);
                                dev->ep[UDC_EP0IN_IX].naking = 0;
                                UDC_QUEUE_CNAK(&dev->ep[UDC_EP0IN_IX],
                                                        UDC_EP0IN_IX);
                                dev->waiting_zlp_ack_ep0in = 0;
                        }
                        goto finished;
                }
                if (ep->dma) {
                        retval = prep_dma(ep, req, GFP_ATOMIC);
                        if (retval != 0)
                                goto finished;
                        /* write desc pointer to enable DMA */
                        if (ep->in) {
                                /* set HOST READY */
                                req->td_data->status =
                                        AMD_ADDBITS(req->td_data->status,
                                                UDC_DMA_IN_STS_BS_HOST_READY,
                                                UDC_DMA_IN_STS_BS);
                        }

                        /* disabled rx dma while descriptor update */
                        if (!ep->in) {
                                /* stop RDE timer */
                                if (timer_pending(&udc_timer)) {
                                        set_rde = 0;
                                        mod_timer(&udc_timer, jiffies - 1);
                                }
                                /* clear RDE */
                                tmp = readl(&dev->regs->ctl);
                                tmp &= AMD_UNMASK_BIT(UDC_DEVCTL_RDE);
                                writel(tmp, &dev->regs->ctl);
                                open_rxfifo = 1;

                                /*
                                 * if BNA occurred then let BNA dummy desc.
                                 * point to current desc.
                                 */
                                if (ep->bna_occurred) {
                                        VDBG(dev, "copy to BNA dummy desc.\n");
                                        memcpy(ep->bna_dummy_req->td_data,
                                                req->td_data,
                                                sizeof(struct udc_data_dma));
                                }
                        }
                        /* write desc pointer */
                        writel(req->td_phys, &ep->regs->desptr);

                        /* clear NAK by writing CNAK */
                        if (ep->naking) {
                                tmp = readl(&ep->regs->ctl);
                                tmp |= AMD_BIT(UDC_EPCTL_CNAK);
                                writel(tmp, &ep->regs->ctl);
                                ep->naking = 0;
                                UDC_QUEUE_CNAK(ep, ep->num);
                        }

                        if (ep->in) {
                                /* enable ep irq */
                                tmp = readl(&dev->regs->ep_irqmsk);
                                tmp &= AMD_UNMASK_BIT(ep->num);
                                writel(tmp, &dev->regs->ep_irqmsk);
                        }
                } else if (ep->in) {
                                /* enable ep irq */
                                tmp = readl(&dev->regs->ep_irqmsk);
                                tmp &= AMD_UNMASK_BIT(ep->num);
                                writel(tmp, &dev->regs->ep_irqmsk);
                        }

        } else if (ep->dma) {

                /*
                 * prep_dma not used for OUT ep's, this is not possible
                 * for PPB modes, because of chain creation reasons
                 */
                if (ep->in) {
                        retval = prep_dma(ep, req, GFP_ATOMIC);
                        if (retval != 0)
                                goto finished;
                }
        }
        VDBG(dev, "list_add\n");
        /* add request to ep queue */
        if (req) {

                list_add_tail(&req->queue, &ep->queue);

                /* open rxfifo if out data queued */
                if (open_rxfifo) {
                        /* enable DMA */
                        req->dma_going = 1;
                        udc_set_rde(dev);
                        if (ep->num != UDC_EP0OUT_IX)
                                dev->data_ep_queued = 1;
                }
                /* stop OUT naking */
                if (!ep->in) {
                        if (!use_dma && udc_rxfifo_pending) {
                                DBG(dev, "udc_queue(): pending bytes in "
                                        "rxfifo after nyet\n");
                                /*
                                 * read pending bytes afer nyet:
                                 * referring to isr
                                 */
                                if (udc_rxfifo_read(ep, req)) {
                                        /* finish */
                                        complete_req(ep, req, 0);
                                }
                                udc_rxfifo_pending = 0;

                        }
                }
        }

finished:
        spin_unlock_irqrestore(&dev->lock, iflags);
        return retval;
}

/* Empty request queue of an endpoint; caller holds spinlock */
void empty_req_queue(struct udc_ep *ep)
{
        struct udc_request      *req;

        ep->halted = 1;
        while (!list_empty(&ep->queue)) {
                req = list_entry(ep->queue.next,
                        struct udc_request,
                        queue);
                complete_req(ep, req, -ESHUTDOWN);
        }
}
EXPORT_SYMBOL_GPL(empty_req_queue);

/* Dequeues a request packet, called by gadget driver */
static int udc_dequeue(struct usb_ep *usbep, struct usb_request *usbreq)
{
        struct udc_ep           *ep;
        struct udc_request      *req;
        unsigned                halted;
        unsigned long           iflags;

        ep = container_of(usbep, struct udc_ep, ep);
        if (!usbep || !usbreq || (!ep->ep.desc && (ep->num != 0
                                && ep->num != UDC_EP0OUT_IX)))
                return -EINVAL;

        req = container_of(usbreq, struct udc_request, req);

        spin_lock_irqsave(&ep->dev->lock, iflags);
        halted = ep->halted;
        ep->halted = 1;
        /* request in processing or next one */
        if (ep->queue.next == &req->queue) {
                if (ep->dma && req->dma_going) {
                        if (ep->in)
                                ep->cancel_transfer = 1;
                        else {
                                u32 tmp;
                                u32 dma_sts;
                                /* stop potential receive DMA */
                                tmp = readl(&udc->regs->ctl);
                                writel(tmp & AMD_UNMASK_BIT(UDC_DEVCTL_RDE),
                                                        &udc->regs->ctl);
                                /*
                                 * Cancel transfer later in ISR
                                 * if descriptor was touched.
                                 */
                                dma_sts = AMD_GETBITS(req->td_data->status,
                                                        UDC_DMA_OUT_STS_BS);
                                if (dma_sts != UDC_DMA_OUT_STS_BS_HOST_READY)
                                        ep->cancel_transfer = 1;
                                else {
                                        udc_init_bna_dummy(ep->req);
                                        writel(ep->bna_dummy_req->td_phys,
                                                &ep->regs->desptr);
                                }
                                writel(tmp, &udc->regs->ctl);
                        }
                }
        }
        complete_req(ep, req, -ECONNRESET);
        ep->halted = halted;

        spin_unlock_irqrestore(&ep->dev->lock, iflags);
        return 0;
}

/* Halt or clear halt of endpoint */
static int
udc_set_halt(struct usb_ep *usbep, int halt)
{
        struct udc_ep   *ep;
        u32 tmp;
        unsigned long iflags;
        int retval = 0;

        if (!usbep)
                return -EINVAL;

        pr_debug("set_halt %s: halt=%d\n", usbep->name, halt);

        ep = container_of(usbep, struct udc_ep, ep);
        if (!ep->ep.desc && (ep->num != 0 && ep->num != UDC_EP0OUT_IX))
                return -EINVAL;
        if (!ep->dev->driver || ep->dev->gadget.speed == USB_SPEED_UNKNOWN)
                return -ESHUTDOWN;

        spin_lock_irqsave(&udc_stall_spinlock, iflags);
        /* halt or clear halt */
        if (halt) {
                if (ep->num == 0)
                        ep->dev->stall_ep0in = 1;
                else {
                        /*
                         * set STALL
                         * rxfifo empty not taken into acount
                         */
                        tmp = readl(&ep->regs->ctl);
                        tmp |= AMD_BIT(UDC_EPCTL_S);
                        writel(tmp, &ep->regs->ctl);
                        ep->halted = 1;

                        /* setup poll timer */
                        if (!timer_pending(&udc_pollstall_timer)) {
                                udc_pollstall_timer.expires = jiffies +
                                        HZ * UDC_POLLSTALL_TIMER_USECONDS
                                        / (1000 * 1000);
                                if (!stop_pollstall_timer) {
                                        DBG(ep->dev, "start polltimer\n");
                                        add_timer(&udc_pollstall_timer);
                                }
                        }
                }
        } else {
                /* ep is halted by set_halt() before */
                if (ep->halted) {
                        tmp = readl(&ep->regs->ctl);
                        /* clear stall bit */
                        tmp = tmp & AMD_CLEAR_BIT(UDC_EPCTL_S);
                        /* clear NAK by writing CNAK */
                        tmp |= AMD_BIT(UDC_EPCTL_CNAK);
                        writel(tmp, &ep->regs->ctl);
                        ep->halted = 0;
                        UDC_QUEUE_CNAK(ep, ep->num);
                }
        }
        spin_unlock_irqrestore(&udc_stall_spinlock, iflags);
        return retval;
}

/* gadget interface */
static const struct usb_ep_ops udc_ep_ops = {
        .enable         = udc_ep_enable,
        .disable        = udc_ep_disable,

        .alloc_request  = udc_alloc_request,
        .free_request   = udc_free_request,

        .queue          = udc_queue,
        .dequeue        = udc_dequeue,

        .set_halt       = udc_set_halt,
        /* fifo ops not implemented */
};

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

/* Get frame counter (not implemented) */
static int udc_get_frame(struct usb_gadget *gadget)
{
        return -EOPNOTSUPP;
}

/* Initiates a remote wakeup */
static int udc_remote_wakeup(struct udc *dev)
{
        unsigned long flags;
        u32 tmp;

        DBG(dev, "UDC initiates remote wakeup\n");

        spin_lock_irqsave(&dev->lock, flags);

        tmp = readl(&dev->regs->ctl);
        tmp |= AMD_BIT(UDC_DEVCTL_RES);
        writel(tmp, &dev->regs->ctl);
        tmp &= AMD_CLEAR_BIT(UDC_DEVCTL_RES);
        writel(tmp, &dev->regs->ctl);

        spin_unlock_irqrestore(&dev->lock, flags);
        return 0;
}

/* Remote wakeup gadget interface */
static int udc_wakeup(struct usb_gadget *gadget)
{
        struct udc              *dev;

        if (!gadget)
                return -EINVAL;
        dev = container_of(gadget, struct udc, gadget);
        udc_remote_wakeup(dev);

        return 0;
}

static int amd5536_udc_start(struct usb_gadget *g,
                struct usb_gadget_driver *driver);
static int amd5536_udc_stop(struct usb_gadget *g);

static const struct usb_gadget_ops udc_ops = {
        .wakeup         = udc_wakeup,
        .get_frame      = udc_get_frame,
        .udc_start      = amd5536_udc_start,
        .udc_stop       = amd5536_udc_stop,
};

/* Setups endpoint parameters, adds endpoints to linked list */
static void make_ep_lists(struct udc *dev)
{
        /* make gadget ep lists */
        INIT_LIST_HEAD(&dev->gadget.ep_list);
        list_add_tail(&dev->ep[UDC_EPIN_STATUS_IX].ep.ep_list,
                                                &dev->gadget.ep_list);
        list_add_tail(&dev->ep[UDC_EPIN_IX].ep.ep_list,
                                                &dev->gadget.ep_list);
        list_add_tail(&dev->ep[UDC_EPOUT_IX].ep.ep_list,
                                                &dev->gadget.ep_list);

        /* fifo config */
        dev->ep[UDC_EPIN_STATUS_IX].fifo_depth = UDC_EPIN_SMALLINT_BUFF_SIZE;
        if (dev->gadget.speed == USB_SPEED_FULL)
                dev->ep[UDC_EPIN_IX].fifo_depth = UDC_FS_EPIN_BUFF_SIZE;
        else if (dev->gadget.speed == USB_SPEED_HIGH)
                dev->ep[UDC_EPIN_IX].fifo_depth = hs_tx_buf;
        dev->ep[UDC_EPOUT_IX].fifo_depth = UDC_RXFIFO_SIZE;
}

/* Inits UDC context */
void udc_basic_init(struct udc *dev)
{
        u32     tmp;

        DBG(dev, "udc_basic_init()\n");

        dev->gadget.speed = USB_SPEED_UNKNOWN;

        /* stop RDE timer */
        if (timer_pending(&udc_timer)) {
                set_rde = 0;
                mod_timer(&udc_timer, jiffies - 1);
        }
        /* stop poll stall timer */
        if (timer_pending(&udc_pollstall_timer))
                mod_timer(&udc_pollstall_timer, jiffies - 1);
        /* disable DMA */
        tmp = readl(&dev->regs->ctl);
        tmp &= AMD_UNMASK_BIT(UDC_DEVCTL_RDE);
        tmp &= AMD_UNMASK_BIT(UDC_DEVCTL_TDE);
        writel(tmp, &dev->regs->ctl);

        /* enable dynamic CSR programming */
        tmp = readl(&dev->regs->cfg);
        tmp |= AMD_BIT(UDC_DEVCFG_CSR_PRG);
        /* set self powered */
        tmp |= AMD_BIT(UDC_DEVCFG_SP);
        /* set remote wakeupable */
        tmp |= AMD_BIT(UDC_DEVCFG_RWKP);
        writel(tmp, &dev->regs->cfg);

        make_ep_lists(dev);

        dev->data_ep_enabled = 0;
        dev->data_ep_queued = 0;
}
EXPORT_SYMBOL_GPL(udc_basic_init);

/* init registers at driver load time */
static int startup_registers(struct udc *dev)
{
        u32 tmp;

        /* init controller by soft reset */
        udc_soft_reset(dev);

        /* mask not needed interrupts */
        udc_mask_unused_interrupts(dev);

        /* put into initial config */
        udc_basic_init(dev);
        /* link up all endpoints */
        udc_setup_endpoints(dev);

        /* program speed */
        tmp = readl(&dev->regs->cfg);
        if (use_fullspeed)
                tmp = AMD_ADDBITS(tmp, UDC_DEVCFG_SPD_FS, UDC_DEVCFG_SPD);
        else
                tmp = AMD_ADDBITS(tmp, UDC_DEVCFG_SPD_HS, UDC_DEVCFG_SPD);
        writel(tmp, &dev->regs->cfg);

        return 0;
}

/* Sets initial endpoint parameters */
static void udc_setup_endpoints(struct udc *dev)
{
        struct udc_ep   *ep;
        u32     tmp;
        u32     reg;

        DBG(dev, "udc_setup_endpoints()\n");

        /* read enum speed */
        tmp = readl(&dev->regs->sts);
        tmp = AMD_GETBITS(tmp, UDC_DEVSTS_ENUM_SPEED);
        if (tmp == UDC_DEVSTS_ENUM_SPEED_HIGH)
                dev->gadget.speed = USB_SPEED_HIGH;
        else if (tmp == UDC_DEVSTS_ENUM_SPEED_FULL)
                dev->gadget.speed = USB_SPEED_FULL;

        /* set basic ep parameters */
        for (tmp = 0; tmp < UDC_EP_NUM; tmp++) {
                ep = &dev->ep[tmp];
                ep->dev = dev;
                ep->ep.name = ep_info[tmp].name;
                ep->ep.caps = ep_info[tmp].caps;
                ep->num = tmp;
                /* txfifo size is calculated at enable time */
                ep->txfifo = dev->txfifo;

                /* fifo size */
                if (tmp < UDC_EPIN_NUM) {
                        ep->fifo_depth = UDC_TXFIFO_SIZE;
                        ep->in = 1;
                } else {
                        ep->fifo_depth = UDC_RXFIFO_SIZE;
                        ep->in = 0;

                }
                ep->regs = &dev->ep_regs[tmp];
                /*
                 * ep will be reset only if ep was not enabled before to avoid
                 * disabling ep interrupts when ENUM interrupt occurs but ep is
                 * not enabled by gadget driver
                 */
                if (!ep->ep.desc)
                        ep_init(dev->regs, ep);

                if (use_dma) {
                        /*
                         * ep->dma is not really used, just to indicate that
                         * DMA is active: remove this
                         * dma regs = dev control regs
                         */
                        ep->dma = &dev->regs->ctl;

                        /* nak OUT endpoints until enable - not for ep0 */
                        if (tmp != UDC_EP0IN_IX && tmp != UDC_EP0OUT_IX
                                                && tmp > UDC_EPIN_NUM) {
                                /* set NAK */
                                reg = readl(&dev->ep[tmp].regs->ctl);
                                reg |= AMD_BIT(UDC_EPCTL_SNAK);
                                writel(reg, &dev->ep[tmp].regs->ctl);
                                dev->ep[tmp].naking = 1;

                        }
                }
        }
        /* EP0 max packet */
        if (dev->gadget.speed == USB_SPEED_FULL) {
                usb_ep_set_maxpacket_limit(&dev->ep[UDC_EP0IN_IX].ep,
                                           UDC_FS_EP0IN_MAX_PKT_SIZE);
                usb_ep_set_maxpacket_limit(&dev->ep[UDC_EP0OUT_IX].ep,
                                           UDC_FS_EP0OUT_MAX_PKT_SIZE);
        } else if (dev->gadget.speed == USB_SPEED_HIGH) {
                usb_ep_set_maxpacket_limit(&dev->ep[UDC_EP0IN_IX].ep,
                                           UDC_EP0IN_MAX_PKT_SIZE);
                usb_ep_set_maxpacket_limit(&dev->ep[UDC_EP0OUT_IX].ep,
                                           UDC_EP0OUT_MAX_PKT_SIZE);
        }

        /*
         * with suspend bug workaround, ep0 params for gadget driver
         * are set at gadget driver bind() call
         */
        dev->gadget.ep0 = &dev->ep[UDC_EP0IN_IX].ep;
        dev->ep[UDC_EP0IN_IX].halted = 0;
        INIT_LIST_HEAD(&dev->gadget.ep0->ep_list);

        /* init cfg/alt/int */
        dev->cur_config = 0;
        dev->cur_intf = 0;
        dev->cur_alt = 0;
}

/* Bringup after Connect event, initial bringup to be ready for ep0 events */
static void usb_connect(struct udc *dev)
{
        /* Return if already connected */
        if (dev->connected)
                return;

        dev_info(dev->dev, "USB Connect\n");

        dev->connected = 1;

        /* put into initial config */
        udc_basic_init(dev);

        /* enable device setup interrupts */
        udc_enable_dev_setup_interrupts(dev);
}

/*
 * Calls gadget with disconnect event and resets the UDC and makes
 * initial bringup to be ready for ep0 events
 */
static void usb_disconnect(struct udc *dev)
{
        /* Return if already disconnected */
        if (!dev->connected)
                return;

        dev_info(dev->dev, "USB Disconnect\n");

        dev->connected = 0;

        /* mask interrupts */
        udc_mask_unused_interrupts(dev);

        /* REVISIT there doesn't seem to be a point to having this
         * talk to a tasklet ... do it directly, we already hold
         * the spinlock needed to process the disconnect.
         */

        tasklet_schedule(&disconnect_tasklet);
}

/* Tasklet for disconnect to be outside of interrupt context */
static void udc_tasklet_disconnect(unsigned long par)
{
        struct udc *dev = (struct udc *)(*((struct udc **) par));
        u32 tmp;

        DBG(dev, "Tasklet disconnect\n");
        spin_lock_irq(&dev->lock);

        if (dev->driver) {
                spin_unlock(&dev->lock);
                dev->driver->disconnect(&dev->gadget);
                spin_lock(&dev->lock);

                /* empty queues */
                for (tmp = 0; tmp < UDC_EP_NUM; tmp++)
                        empty_req_queue(&dev->ep[tmp]);

        }

        /* disable ep0 */
        ep_init(dev->regs,
                        &dev->ep[UDC_EP0IN_IX]);


        if (!soft_reset_occured) {
                /* init controller by soft reset */
                udc_soft_reset(dev);
                soft_reset_occured++;
        }

        /* re-enable dev interrupts */
        udc_enable_dev_setup_interrupts(dev);
        /* back to full speed ? */
        if (use_fullspeed) {
                tmp = readl(&dev->regs->cfg);
                tmp = AMD_ADDBITS(tmp, UDC_DEVCFG_SPD_FS, UDC_DEVCFG_SPD);
                writel(tmp, &dev->regs->cfg);
        }

        spin_unlock_irq(&dev->lock);
}

/* Reset the UDC core */
static void udc_soft_reset(struct udc *dev)
{
        unsigned long   flags;

        DBG(dev, "Soft reset\n");
        /*
         * reset possible waiting interrupts, because int.
         * status is lost after soft reset,
         * ep int. status reset
         */
        writel(UDC_EPINT_MSK_DISABLE_ALL, &dev->regs->ep_irqsts);
        /* device int. status reset */
        writel(UDC_DEV_MSK_DISABLE, &dev->regs->irqsts);

        /* Don't do this for Broadcom UDC since this is a reserved
         * bit.
         */
        if (dev->chiprev != UDC_BCM_REV) {
                spin_lock_irqsave(&udc_irq_spinlock, flags);
                writel(AMD_BIT(UDC_DEVCFG_SOFTRESET), &dev->regs->cfg);
                readl(&dev->regs->cfg);
                spin_unlock_irqrestore(&udc_irq_spinlock, flags);
        }
}

/* RDE timer callback to set RDE bit */
static void udc_timer_function(struct timer_list *unused)
{
        u32 tmp;

        spin_lock_irq(&udc_irq_spinlock);

        if (set_rde > 0) {
                /*
                 * open the fifo if fifo was filled on last timer call
                 * conditionally
                 */
                if (set_rde > 1) {
                        /* set RDE to receive setup data */
                        tmp = readl(&udc->regs->ctl);
                        tmp |= AMD_BIT(UDC_DEVCTL_RDE);
                        writel(tmp, &udc->regs->ctl);
                        set_rde = -1;
                } else if (readl(&udc->regs->sts)
                                & AMD_BIT(UDC_DEVSTS_RXFIFO_EMPTY)) {
                        /*
                         * if fifo empty setup polling, do not just
                         * open the fifo
                         */
                        udc_timer.expires = jiffies + HZ/UDC_RDE_TIMER_DIV;
                        if (!stop_timer)
                                add_timer(&udc_timer);
                } else {
                        /*
                         * fifo contains data now, setup timer for opening
                         * the fifo when timer expires to be able to receive
                         * setup packets, when data packets gets queued by
                         * gadget layer then timer will forced to expire with
                         * set_rde=0 (RDE is set in udc_queue())
                         */
                        set_rde++;
                        /* debug: lhadmot_timer_start = 221070 */
                        udc_timer.expires = jiffies + HZ*UDC_RDE_TIMER_SECONDS;
                        if (!stop_timer)
                                add_timer(&udc_timer);
                }

        } else
                set_rde = -1; /* RDE was set by udc_queue() */
        spin_unlock_irq(&udc_irq_spinlock);
        if (stop_timer)
                complete(&on_exit);

}

/* Handle halt state, used in stall poll timer */
static void udc_handle_halt_state(struct udc_ep *ep)
{
        u32 tmp;
        /* set stall as long not halted */
        if (ep->halted == 1) {
                tmp = readl(&ep->regs->ctl);
                /* STALL cleared ? */
                if (!(tmp & AMD_BIT(UDC_EPCTL_S))) {
                        /*
                         * FIXME: MSC spec requires that stall remains
                         * even on receivng of CLEAR_FEATURE HALT. So
                         * we would set STALL again here to be compliant.
                         * But with current mass storage drivers this does
                         * not work (would produce endless host retries).
                         * So we clear halt on CLEAR_FEATURE.
                         *
                        DBG(ep->dev, "ep %d: set STALL again\n", ep->num);
                        tmp |= AMD_BIT(UDC_EPCTL_S);
                        writel(tmp, &ep->regs->ctl);*/

                        /* clear NAK by writing CNAK */
                        tmp |= AMD_BIT(UDC_EPCTL_CNAK);
                        writel(tmp, &ep->regs->ctl);
                        ep->halted = 0;
                        UDC_QUEUE_CNAK(ep, ep->num);
                }
        }
}

/* Stall timer callback to poll S bit and set it again after */
static void udc_pollstall_timer_function(struct timer_list *unused)
{
        struct udc_ep *ep;
        int halted = 0;

        spin_lock_irq(&udc_stall_spinlock);
        /*
         * only one IN and OUT endpoints are handled
         * IN poll stall
         */
        ep = &udc->ep[UDC_EPIN_IX];
        udc_handle_halt_state(ep);
        if (ep->halted)
                halted = 1;
        /* OUT poll stall */
        ep = &udc->ep[UDC_EPOUT_IX];
        udc_handle_halt_state(ep);
        if (ep->halted)
                halted = 1;

        /* setup timer again when still halted */
        if (!stop_pollstall_timer && halted) {
                udc_pollstall_timer.expires = jiffies +
                                        HZ * UDC_POLLSTALL_TIMER_USECONDS
                                        / (1000 * 1000);
                add_timer(&udc_pollstall_timer);
        }
        spin_unlock_irq(&udc_stall_spinlock);

        if (stop_pollstall_timer)
                complete(&on_pollstall_exit);
}

/* Inits endpoint 0 so that SETUP packets are processed */
static void activate_control_endpoints(struct udc *dev)
{
        u32 tmp;

        DBG(dev, "activate_control_endpoints\n");

        /* flush fifo */
        tmp = readl(&dev->ep[UDC_EP0IN_IX].regs->ctl);
        tmp |= AMD_BIT(UDC_EPCTL_F);
        writel(tmp, &dev->ep[UDC_EP0IN_IX].regs->ctl);

        /* set ep0 directions */
        dev->ep[UDC_EP0IN_IX].in = 1;
        dev->ep[UDC_EP0OUT_IX].in = 0;

        /* set buffer size (tx fifo entries) of EP0_IN */
        tmp = readl(&dev->ep[UDC_EP0IN_IX].regs->bufin_framenum);
        if (dev->gadget.speed == USB_SPEED_FULL)
                tmp = AMD_ADDBITS(tmp, UDC_FS_EPIN0_BUFF_SIZE,
                                        UDC_EPIN_BUFF_SIZE);
        else if (dev->gadget.speed == USB_SPEED_HIGH)
                tmp = AMD_ADDBITS(tmp, UDC_EPIN0_BUFF_SIZE,
                                        UDC_EPIN_BUFF_SIZE);
        writel(tmp, &dev->ep[UDC_EP0IN_IX].regs->bufin_framenum);

        /* set max packet size of EP0_IN */
        tmp = readl(&dev->ep[UDC_EP0IN_IX].regs->bufout_maxpkt);
        if (dev->gadget.speed == USB_SPEED_FULL)
                tmp = AMD_ADDBITS(tmp, UDC_FS_EP0IN_MAX_PKT_SIZE,
                                        UDC_EP_MAX_PKT_SIZE);
        else if (dev->gadget.speed == USB_SPEED_HIGH)
                tmp = AMD_ADDBITS(tmp, UDC_EP0IN_MAX_PKT_SIZE,
                                UDC_EP_MAX_PKT_SIZE);
        writel(tmp, &dev->ep[UDC_EP0IN_IX].regs->bufout_maxpkt);

        /* set max packet size of EP0_OUT */
        tmp = readl(&dev->ep[UDC_EP0OUT_IX].regs->bufout_maxpkt);
        if (dev->gadget.speed == USB_SPEED_FULL)
                tmp = AMD_ADDBITS(tmp, UDC_FS_EP0OUT_MAX_PKT_SIZE,
                                        UDC_EP_MAX_PKT_SIZE);
        else if (dev->gadget.speed == USB_SPEED_HIGH)
                tmp = AMD_ADDBITS(tmp, UDC_EP0OUT_MAX_PKT_SIZE,
                                        UDC_EP_MAX_PKT_SIZE);
        writel(tmp, &dev->ep[UDC_EP0OUT_IX].regs->bufout_maxpkt);

        /* set max packet size of EP0 in UDC CSR */
        tmp = readl(&dev->csr->ne[0]);
        if (dev->gadget.speed == USB_SPEED_FULL)
                tmp = AMD_ADDBITS(tmp, UDC_FS_EP0OUT_MAX_PKT_SIZE,
                                        UDC_CSR_NE_MAX_PKT);
        else if (dev->gadget.speed == USB_SPEED_HIGH)
                tmp = AMD_ADDBITS(tmp, UDC_EP0OUT_MAX_PKT_SIZE,
                                        UDC_CSR_NE_MAX_PKT);
        writel(tmp, &dev->csr->ne[0]);

        if (use_dma) {
                dev->ep[UDC_EP0OUT_IX].td->status |=
                        AMD_BIT(UDC_DMA_OUT_STS_L);
                /* write dma desc address */
                writel(dev->ep[UDC_EP0OUT_IX].td_stp_dma,
                        &dev->ep[UDC_EP0OUT_IX].regs->subptr);
                writel(dev->ep[UDC_EP0OUT_IX].td_phys,
                        &dev->ep[UDC_EP0OUT_IX].regs->desptr);
                /* stop RDE timer */
                if (timer_pending(&udc_timer)) {
                        set_rde = 0;
                        mod_timer(&udc_timer, jiffies - 1);
                }
                /* stop pollstall timer */
                if (timer_pending(&udc_pollstall_timer))
                        mod_timer(&udc_pollstall_timer, jiffies - 1);
                /* enable DMA */
                tmp = readl(&dev->regs->ctl);
                tmp |= AMD_BIT(UDC_DEVCTL_MODE)
                                | AMD_BIT(UDC_DEVCTL_RDE)
                                | AMD_BIT(UDC_DEVCTL_TDE);
                if (use_dma_bufferfill_mode)
                        tmp |= AMD_BIT(UDC_DEVCTL_BF);
                else if (use_dma_ppb_du)
                        tmp |= AMD_BIT(UDC_DEVCTL_DU);
                writel(tmp, &dev->regs->ctl);
        }

        /* clear NAK by writing CNAK for EP0IN */
        tmp = readl(&dev->ep[UDC_EP0IN_IX].regs->ctl);
        tmp |= AMD_BIT(UDC_EPCTL_CNAK);
        writel(tmp, &dev->ep[UDC_EP0IN_IX].regs->ctl);
        dev->ep[UDC_EP0IN_IX].naking = 0;
        UDC_QUEUE_CNAK(&dev->ep[UDC_EP0IN_IX], UDC_EP0IN_IX);

        /* clear NAK by writing CNAK for EP0OUT */
        tmp = readl(&dev->ep[UDC_EP0OUT_IX].regs->ctl);
        tmp |= AMD_BIT(UDC_EPCTL_CNAK);
        writel(tmp, &dev->ep[UDC_EP0OUT_IX].regs->ctl);
        dev->ep[UDC_EP0OUT_IX].naking = 0;
        UDC_QUEUE_CNAK(&dev->ep[UDC_EP0OUT_IX], UDC_EP0OUT_IX);
}

/* Make endpoint 0 ready for control traffic */
static int setup_ep0(struct udc *dev)
{
        activate_control_endpoints(dev);
        /* enable ep0 interrupts */
        udc_enable_ep0_interrupts(dev);
        /* enable device setup interrupts */
        udc_enable_dev_setup_interrupts(dev);

        return 0;
}

/* Called by gadget driver to register itself */
static int amd5536_udc_start(struct usb_gadget *g,
                struct usb_gadget_driver *driver)
{
        struct udc *dev = to_amd5536_udc(g);
        u32 tmp;

        driver->driver.bus = NULL;
        dev->driver = driver;

        /* Some gadget drivers use both ep0 directions.
         * NOTE: to gadget driver, ep0 is just one endpoint...
         */
        dev->ep[UDC_EP0OUT_IX].ep.driver_data =
                dev->ep[UDC_EP0IN_IX].ep.driver_data;

        /* get ready for ep0 traffic */
        setup_ep0(dev);

        /* clear SD */
        tmp = readl(&dev->regs->ctl);
        tmp = tmp & AMD_CLEAR_BIT(UDC_DEVCTL_SD);
        writel(tmp, &dev->regs->ctl);

        usb_connect(dev);

        return 0;
}

/* shutdown requests and disconnect from gadget */
static void
shutdown(struct udc *dev, struct usb_gadget_driver *driver)
__releases(dev->lock)
__acquires(dev->lock)
{
        int tmp;

        /* empty queues and init hardware */
        udc_basic_init(dev);

        for (tmp = 0; tmp < UDC_EP_NUM; tmp++)
                empty_req_queue(&dev->ep[tmp]);

        udc_setup_endpoints(dev);
}

/* Called by gadget driver to unregister itself */
static int amd5536_udc_stop(struct usb_gadget *g)
{
        struct udc *dev = to_amd5536_udc(g);
        unsigned long flags;
        u32 tmp;

        spin_lock_irqsave(&dev->lock, flags);
        udc_mask_unused_interrupts(dev);
        shutdown(dev, NULL);
        spin_unlock_irqrestore(&dev->lock, flags);

        dev->driver = NULL;

        /* set SD */
        tmp = readl(&dev->regs->ctl);
        tmp |= AMD_BIT(UDC_DEVCTL_SD);
        writel(tmp, &dev->regs->ctl);

        return 0;
}

/* Clear pending NAK bits */
static void udc_process_cnak_queue(struct udc *dev)
{
        u32 tmp;
        u32 reg;

        /* check epin's */
        DBG(dev, "CNAK pending queue processing\n");
        for (tmp = 0; tmp < UDC_EPIN_NUM_USED; tmp++) {
                if (cnak_pending & (1 << tmp)) {
                        DBG(dev, "CNAK pending for ep%d\n", tmp);
                        /* clear NAK by writing CNAK */
                        reg = readl(&dev->ep[tmp].regs->ctl);
                        reg |= AMD_BIT(UDC_EPCTL_CNAK);
                        writel(reg, &dev->ep[tmp].regs->ctl);
                        dev->ep[tmp].naking = 0;
                        UDC_QUEUE_CNAK(&dev->ep[tmp], dev->ep[tmp].num);
                }
        }
        /* ...  and ep0out */
        if (cnak_pending & (1 << UDC_EP0OUT_IX)) {
                DBG(dev, "CNAK pending for ep%d\n", UDC_EP0OUT_IX);
                /* clear NAK by writing CNAK */
                reg = readl(&dev->ep[UDC_EP0OUT_IX].regs->ctl);
                reg |= AMD_BIT(UDC_EPCTL_CNAK);
                writel(reg, &dev->ep[UDC_EP0OUT_IX].regs->ctl);
                dev->ep[UDC_EP0OUT_IX].naking = 0;
                UDC_QUEUE_CNAK(&dev->ep[UDC_EP0OUT_IX],
                                dev->ep[UDC_EP0OUT_IX].num);
        }
}

/* Enabling RX DMA after setup packet */
static void udc_ep0_set_rde(struct udc *dev)
{
        if (use_dma) {
                /*
                 * only enable RXDMA when no data endpoint enabled
                 * or data is queued
                 */
                if (!dev->data_ep_enabled || dev->data_ep_queued) {
                        udc_set_rde(dev);
                } else {
                        /*
                         * setup timer for enabling RDE (to not enable
                         * RXFIFO DMA for data endpoints to early)
                         */
                        if (set_rde != 0 && !timer_pending(&udc_timer)) {
                                udc_timer.expires =
                                        jiffies + HZ/UDC_RDE_TIMER_DIV;
                                set_rde = 1;
                                if (!stop_timer)
                                        add_timer(&udc_timer);
                        }
                }
        }
}


/* Interrupt handler for data OUT traffic */
static irqreturn_t udc_data_out_isr(struct udc *dev, int ep_ix)
{
        irqreturn_t             ret_val = IRQ_NONE;
        u32                     tmp;
        struct udc_ep           *ep;
        struct udc_request      *req;
        unsigned int            count;
        struct udc_data_dma     *td = NULL;
        unsigned                dma_done;

        VDBG(dev, "ep%d irq\n", ep_ix);
        ep = &dev->ep[ep_ix];

        tmp = readl(&ep->regs->sts);
        if (use_dma) {
                /* BNA event ? */
                if (tmp & AMD_BIT(UDC_EPSTS_BNA)) {
                        DBG(dev, "BNA ep%dout occurred - DESPTR = %x\n",
                                        ep->num, readl(&ep->regs->desptr));
                        /* clear BNA */
                        writel(tmp | AMD_BIT(UDC_EPSTS_BNA), &ep->regs->sts);
                        if (!ep->cancel_transfer)
                                ep->bna_occurred = 1;
                        else
                                ep->cancel_transfer = 0;
                        ret_val = IRQ_HANDLED;
                        goto finished;
                }
        }
        /* HE event ? */
        if (tmp & AMD_BIT(UDC_EPSTS_HE)) {
                dev_err(dev->dev, "HE ep%dout occurred\n", ep->num);

                /* clear HE */
                writel(tmp | AMD_BIT(UDC_EPSTS_HE), &ep->regs->sts);
                ret_val = IRQ_HANDLED;
                goto finished;
        }

        if (!list_empty(&ep->queue)) {

                /* next request */
                req = list_entry(ep->queue.next,
                        struct udc_request, queue);
        } else {
                req = NULL;
                udc_rxfifo_pending = 1;
        }
        VDBG(dev, "req = %p\n", req);
        /* fifo mode */
        if (!use_dma) {

                /* read fifo */
                if (req && udc_rxfifo_read(ep, req)) {
                        ret_val = IRQ_HANDLED;

                        /* finish */
                        complete_req(ep, req, 0);
                        /* next request */
                        if (!list_empty(&ep->queue) && !ep->halted) {
                                req = list_entry(ep->queue.next,
                                        struct udc_request, queue);
                        } else
                                req = NULL;
                }

        /* DMA */
        } else if (!ep->cancel_transfer && req) {
                ret_val = IRQ_HANDLED;

                /* check for DMA done */
                if (!use_dma_ppb) {
                        dma_done = AMD_GETBITS(req->td_data->status,
                                                UDC_DMA_OUT_STS_BS);
                /* packet per buffer mode - rx bytes */
                } else {
                        /*
                         * if BNA occurred then recover desc. from
                         * BNA dummy desc.
                         */
                        if (ep->bna_occurred) {
                                VDBG(dev, "Recover desc. from BNA dummy\n");
                                memcpy(req->td_data, ep->bna_dummy_req->td_data,
                                                sizeof(struct udc_data_dma));
                                ep->bna_occurred = 0;
                                udc_init_bna_dummy(ep->req);
                        }
                        td = udc_get_last_dma_desc(req);
                        dma_done = AMD_GETBITS(td->status, UDC_DMA_OUT_STS_BS);
                }
                if (dma_done == UDC_DMA_OUT_STS_BS_DMA_DONE) {
                        /* buffer fill mode - rx bytes */
                        if (!use_dma_ppb) {
                                /* received number bytes */
                                count = AMD_GETBITS(req->td_data->status,
                                                UDC_DMA_OUT_STS_RXBYTES);
                                VDBG(dev, "rx bytes=%u\n", count);
                        /* packet per buffer mode - rx bytes */
                        } else {
                                VDBG(dev, "req->td_data=%p\n", req->td_data);
                                VDBG(dev, "last desc = %p\n", td);
                                /* received number bytes */
                                if (use_dma_ppb_du) {
                                        /* every desc. counts bytes */
                                        count = udc_get_ppbdu_rxbytes(req);
                                } else {
                                        /* last desc. counts bytes */
                                        count = AMD_GETBITS(td->status,
                                                UDC_DMA_OUT_STS_RXBYTES);
                                        if (!count && req->req.length
                                                == UDC_DMA_MAXPACKET) {
                                                /*
                                                 * on 64k packets the RXBYTES
                                                 * field is zero
                                                 */
                                                count = UDC_DMA_MAXPACKET;
                                        }
                                }
                                VDBG(dev, "last desc rx bytes=%u\n", count);
                        }

                        tmp = req->req.length - req->req.actual;
                        if (count > tmp) {
                                if ((tmp % ep->ep.maxpacket) != 0) {
                                        DBG(dev, "%s: rx %db, space=%db\n",
                                                ep->ep.name, count, tmp);
                                        req->req.status = -EOVERFLOW;
                                }
                                count = tmp;
                        }
                        req->req.actual += count;
                        req->dma_going = 0;
                        /* complete request */
                        complete_req(ep, req, 0);

                        /* next request */
                        if (!list_empty(&ep->queue) && !ep->halted) {
                                req = list_entry(ep->queue.next,
                                        struct udc_request,
                                        queue);
                                /*
                                 * DMA may be already started by udc_queue()
                                 * called by gadget drivers completion
                                 * routine. This happens when queue
                                 * holds one request only.
                                 */
                                if (req->dma_going == 0) {
                                        /* next dma */
                                        if (prep_dma(ep, req, GFP_ATOMIC) != 0)
                                                goto finished;
                                        /* write desc pointer */
                                        writel(req->td_phys,
                                                &ep->regs->desptr);
                                        req->dma_going = 1;
                                        /* enable DMA */
                                        udc_set_rde(dev);
                                }
                        } else {
                                /*
                                 * implant BNA dummy descriptor to allow
                                 * RXFIFO opening by RDE
                                 */
                                if (ep->bna_dummy_req) {
                                        /* write desc pointer */
                                        writel(ep->bna_dummy_req->td_phys,
                                                &ep->regs->desptr);
                                        ep->bna_occurred = 0;
                                }

                                /*
                                 * schedule timer for setting RDE if queue
                                 * remains empty to allow ep0 packets pass
                                 * through
                                 */
                                if (set_rde != 0
                                                && !timer_pending(&udc_timer)) {
                                        udc_timer.expires =
                                                jiffies
                                                + HZ*UDC_RDE_TIMER_SECONDS;
                                        set_rde = 1;
                                        if (!stop_timer)
                                                add_timer(&udc_timer);
                                }
                                if (ep->num != UDC_EP0OUT_IX)
                                        dev->data_ep_queued = 0;
                        }

                } else {
                        /*
                        * RX DMA must be reenabled for each desc in PPBDU mode
                        * and must be enabled for PPBNDU mode in case of BNA
                        */
                        udc_set_rde(dev);
                }

        } else if (ep->cancel_transfer) {
                ret_val = IRQ_HANDLED;
                ep->cancel_transfer = 0;
        }

        /* check pending CNAKS */
        if (cnak_pending) {
                /* CNAk processing when rxfifo empty only */
                if (readl(&dev->regs->sts) & AMD_BIT(UDC_DEVSTS_RXFIFO_EMPTY))
                        udc_process_cnak_queue(dev);
        }

        /* clear OUT bits in ep status */
        writel(UDC_EPSTS_OUT_CLEAR, &ep->regs->sts);
finished:
        return ret_val;
}

/* Interrupt handler for data IN traffic */
static irqreturn_t udc_data_in_isr(struct udc *dev, int ep_ix)
{
        irqreturn_t ret_val = IRQ_NONE;
        u32 tmp;
        u32 epsts;
        struct udc_ep *ep;
        struct udc_request *req;
        struct udc_data_dma *td;
        unsigned len;

        ep = &dev->ep[ep_ix];

        epsts = readl(&ep->regs->sts);
        if (use_dma) {
                /* BNA ? */
                if (epsts & AMD_BIT(UDC_EPSTS_BNA)) {
                        dev_err(dev->dev,
                                "BNA ep%din occurred - DESPTR = %08lx\n",
                                ep->num,
                                (unsigned long) readl(&ep->regs->desptr));

                        /* clear BNA */
                        writel(epsts, &ep->regs->sts);
                        ret_val = IRQ_HANDLED;
                        goto finished;
                }
        }
        /* HE event ? */
        if (epsts & AMD_BIT(UDC_EPSTS_HE)) {
                dev_err(dev->dev,
                        "HE ep%dn occurred - DESPTR = %08lx\n",
                        ep->num, (unsigned long) readl(&ep->regs->desptr));

                /* clear HE */
                writel(epsts | AMD_BIT(UDC_EPSTS_HE), &ep->regs->sts);
                ret_val = IRQ_HANDLED;
                goto finished;
        }

        /* DMA completion */
        if (epsts & AMD_BIT(UDC_EPSTS_TDC)) {
                VDBG(dev, "TDC set- completion\n");
                ret_val = IRQ_HANDLED;
                if (!ep->cancel_transfer && !list_empty(&ep->queue)) {
                        req = list_entry(ep->queue.next,
                                        struct udc_request, queue);
                        /*
                         * length bytes transferred
                         * check dma done of last desc. in PPBDU mode
                         */
                        if (use_dma_ppb_du) {
                                td = udc_get_last_dma_desc(req);
                                if (td)
                                        req->req.actual = req->req.length;
                        } else {
                                /* assume all bytes transferred */
                                req->req.actual = req->req.length;
                        }

                        if (req->req.actual == req->req.length) {
                                /* complete req */
                                complete_req(ep, req, 0);
                                req->dma_going = 0;
                                /* further request available ? */
                                if (list_empty(&ep->queue)) {
                                        /* disable interrupt */
                                        tmp = readl(&dev->regs->ep_irqmsk);
                                        tmp |= AMD_BIT(ep->num);
                                        writel(tmp, &dev->regs->ep_irqmsk);
                                }
                        }
                }
                ep->cancel_transfer = 0;

        }
        /*
         * status reg has IN bit set and TDC not set (if TDC was handled,
         * IN must not be handled (UDC defect) ?
         */
        if ((epsts & AMD_BIT(UDC_EPSTS_IN))
                        && !(epsts & AMD_BIT(UDC_EPSTS_TDC))) {
                ret_val = IRQ_HANDLED;
                if (!list_empty(&ep->queue)) {
                        /* next request */
                        req = list_entry(ep->queue.next,
                                        struct udc_request, queue);
                        /* FIFO mode */
                        if (!use_dma) {
                                /* write fifo */
                                udc_txfifo_write(ep, &req->req);
                                len = req->req.length - req->req.actual;
                                if (len > ep->ep.maxpacket)
                                        len = ep->ep.maxpacket;
                                req->req.actual += len;
                                if (req->req.actual == req->req.length
                                        || (len != ep->ep.maxpacket)) {
                                        /* complete req */
                                        complete_req(ep, req, 0);
                                }
                        /* DMA */
                        } else if (req && !req->dma_going) {
                                VDBG(dev, "IN DMA : req=%p req->td_data=%p\n",
                                        req, req->td_data);
                                if (req->td_data) {

                                        req->dma_going = 1;

                                        /*
                                         * unset L bit of first desc.
                                         * for chain
                                         */
                                        if (use_dma_ppb && req->req.length >
                                                        ep->ep.maxpacket) {
                                                req->td_data->status &=
                                                        AMD_CLEAR_BIT(
                                                        UDC_DMA_IN_STS_L);
                                        }

                                        /* write desc pointer */
                                        writel(req->td_phys, &ep->regs->desptr);

                                        /* set HOST READY */
                                        req->td_data->status =
                                                AMD_ADDBITS(
                                                req->td_data->status,
                                                UDC_DMA_IN_STS_BS_HOST_READY,
                                                UDC_DMA_IN_STS_BS);

                                        /* set poll demand bit */
                                        tmp = readl(&ep->regs->ctl);
                                        tmp |= AMD_BIT(UDC_EPCTL_P);
                                        writel(tmp, &ep->regs->ctl);
                                }
                        }

                } else if (!use_dma && ep->in) {
                        /* disable interrupt */
                        tmp = readl(
                                &dev->regs->ep_irqmsk);
                        tmp |= AMD_BIT(ep->num);
                        writel(tmp,
                                &dev->regs->ep_irqmsk);
                }
        }
        /* clear status bits */
        writel(epsts, &ep->regs->sts);

finished:
        return ret_val;

}

/* Interrupt handler for Control OUT traffic */
static irqreturn_t udc_control_out_isr(struct udc *dev)
__releases(dev->lock)
__acquires(dev->lock)
{
        irqreturn_t ret_val = IRQ_NONE;
        u32 tmp;
        int setup_supported;
        u32 count;
        int set = 0;
        struct udc_ep   *ep;
        struct udc_ep   *ep_tmp;

        ep = &dev->ep[UDC_EP0OUT_IX];

        /* clear irq */
        writel(AMD_BIT(UDC_EPINT_OUT_EP0), &dev->regs->ep_irqsts);

        tmp = readl(&dev->ep[UDC_EP0OUT_IX].regs->sts);
        /* check BNA and clear if set */
        if (tmp & AMD_BIT(UDC_EPSTS_BNA)) {
                VDBG(dev, "ep0: BNA set\n");
                writel(AMD_BIT(UDC_EPSTS_BNA),
                        &dev->ep[UDC_EP0OUT_IX].regs->sts);
                ep->bna_occurred = 1;
                ret_val = IRQ_HANDLED;
                goto finished;
        }

        /* type of data: SETUP or DATA 0 bytes */
        tmp = AMD_GETBITS(tmp, UDC_EPSTS_OUT);
        VDBG(dev, "data_typ = %x\n", tmp);

        /* setup data */
        if (tmp == UDC_EPSTS_OUT_SETUP) {
                ret_val = IRQ_HANDLED;

                ep->dev->stall_ep0in = 0;
                dev->waiting_zlp_ack_ep0in = 0;

                /* set NAK for EP0_IN */
                tmp = readl(&dev->ep[UDC_EP0IN_IX].regs->ctl);
                tmp |= AMD_BIT(UDC_EPCTL_SNAK);
                writel(tmp, &dev->ep[UDC_EP0IN_IX].regs->ctl);
                dev->ep[UDC_EP0IN_IX].naking = 1;
                /* get setup data */
                if (use_dma) {

                        /* clear OUT bits in ep status */
                        writel(UDC_EPSTS_OUT_CLEAR,
                                &dev->ep[UDC_EP0OUT_IX].regs->sts);

                        setup_data.data[0] =
                                dev->ep[UDC_EP0OUT_IX].td_stp->data12;
                        setup_data.data[1] =
                                dev->ep[UDC_EP0OUT_IX].td_stp->data34;
                        /* set HOST READY */
                        dev->ep[UDC_EP0OUT_IX].td_stp->status =
                                        UDC_DMA_STP_STS_BS_HOST_READY;
                } else {
                        /* read fifo */
                        udc_rxfifo_read_dwords(dev, setup_data.data, 2);
                }

                /* determine direction of control data */
                if ((setup_data.request.bRequestType & USB_DIR_IN) != 0) {
                        dev->gadget.ep0 = &dev->ep[UDC_EP0IN_IX].ep;
                        /* enable RDE */
                        udc_ep0_set_rde(dev);
                        set = 0;
                } else {
                        dev->gadget.ep0 = &dev->ep[UDC_EP0OUT_IX].ep;
                        /*
                         * implant BNA dummy descriptor to allow RXFIFO opening
                         * by RDE
                         */
                        if (ep->bna_dummy_req) {
                                /* write desc pointer */
                                writel(ep->bna_dummy_req->td_phys,
                                        &dev->ep[UDC_EP0OUT_IX].regs->desptr);
                                ep->bna_occurred = 0;
                        }

                        set = 1;
                        dev->ep[UDC_EP0OUT_IX].naking = 1;
                        /*
                         * setup timer for enabling RDE (to not enable
                         * RXFIFO DMA for data to early)
                         */
                        set_rde = 1;
                        if (!timer_pending(&udc_timer)) {
                                udc_timer.expires = jiffies +
                                                        HZ/UDC_RDE_TIMER_DIV;
                                if (!stop_timer)
                                        add_timer(&udc_timer);
                        }
                }

                /*
                 * mass storage reset must be processed here because
                 * next packet may be a CLEAR_FEATURE HALT which would not
                 * clear the stall bit when no STALL handshake was received
                 * before (autostall can cause this)
                 */
                if (setup_data.data[0] == UDC_MSCRES_DWORD0
                                && setup_data.data[1] == UDC_MSCRES_DWORD1) {
                        DBG(dev, "MSC Reset\n");
                        /*
                         * clear stall bits
                         * only one IN and OUT endpoints are handled
                         */
                        ep_tmp = &udc->ep[UDC_EPIN_IX];
                        udc_set_halt(&ep_tmp->ep, 0);
                        ep_tmp = &udc->ep[UDC_EPOUT_IX];
                        udc_set_halt(&ep_tmp->ep, 0);
                }

                /* call gadget with setup data received */
                spin_unlock(&dev->lock);
                setup_supported = dev->driver->setup(&dev->gadget,
                                                &setup_data.request);
                spin_lock(&dev->lock);

                tmp = readl(&dev->ep[UDC_EP0IN_IX].regs->ctl);
                /* ep0 in returns data (not zlp) on IN phase */
                if (setup_supported >= 0 && setup_supported <
                                UDC_EP0IN_MAXPACKET) {
                        /* clear NAK by writing CNAK in EP0_IN */
                        tmp |= AMD_BIT(UDC_EPCTL_CNAK);
                        writel(tmp, &dev->ep[UDC_EP0IN_IX].regs->ctl);
                        dev->ep[UDC_EP0IN_IX].naking = 0;
                        UDC_QUEUE_CNAK(&dev->ep[UDC_EP0IN_IX], UDC_EP0IN_IX);

                /* if unsupported request then stall */
                } else if (setup_supported < 0) {
                        tmp |= AMD_BIT(UDC_EPCTL_S);
                        writel(tmp, &dev->ep[UDC_EP0IN_IX].regs->ctl);
                } else
                        dev->waiting_zlp_ack_ep0in = 1;


                /* clear NAK by writing CNAK in EP0_OUT */
                if (!set) {
                        tmp = readl(&dev->ep[UDC_EP0OUT_IX].regs->ctl);
                        tmp |= AMD_BIT(UDC_EPCTL_CNAK);
                        writel(tmp, &dev->ep[UDC_EP0OUT_IX].regs->ctl);
                        dev->ep[UDC_EP0OUT_IX].naking = 0;
                        UDC_QUEUE_CNAK(&dev->ep[UDC_EP0OUT_IX], UDC_EP0OUT_IX);
                }

                if (!use_dma) {
                        /* clear OUT bits in ep status */
                        writel(UDC_EPSTS_OUT_CLEAR,
                                &dev->ep[UDC_EP0OUT_IX].regs->sts);
                }

        /* data packet 0 bytes */
        } else if (tmp == UDC_EPSTS_OUT_DATA) {
                /* clear OUT bits in ep status */
                writel(UDC_EPSTS_OUT_CLEAR, &dev->ep[UDC_EP0OUT_IX].regs->sts);

                /* get setup data: only 0 packet */
                if (use_dma) {
                        /* no req if 0 packet, just reactivate */
                        if (list_empty(&dev->ep[UDC_EP0OUT_IX].queue)) {
                                VDBG(dev, "ZLP\n");

                                /* set HOST READY */
                                dev->ep[UDC_EP0OUT_IX].td->status =
                                        AMD_ADDBITS(
                                        dev->ep[UDC_EP0OUT_IX].td->status,
                                        UDC_DMA_OUT_STS_BS_HOST_READY,
                                        UDC_DMA_OUT_STS_BS);
                                /* enable RDE */
                                udc_ep0_set_rde(dev);
                                ret_val = IRQ_HANDLED;

                        } else {
                                /* control write */
                                ret_val |= udc_data_out_isr(dev, UDC_EP0OUT_IX);
                                /* re-program desc. pointer for possible ZLPs */
                                writel(dev->ep[UDC_EP0OUT_IX].td_phys,
                                        &dev->ep[UDC_EP0OUT_IX].regs->desptr);
                                /* enable RDE */
                                udc_ep0_set_rde(dev);
                        }
                } else {

                        /* received number bytes */
                        count = readl(&dev->ep[UDC_EP0OUT_IX].regs->sts);
                        count = AMD_GETBITS(count, UDC_EPSTS_RX_PKT_SIZE);
                        /* out data for fifo mode not working */
                        count = 0;

                        /* 0 packet or real data ? */
                        if (count != 0) {
                                ret_val |= udc_data_out_isr(dev, UDC_EP0OUT_IX);
                        } else {
                                /* dummy read confirm */
                                readl(&dev->ep[UDC_EP0OUT_IX].regs->confirm);
                                ret_val = IRQ_HANDLED;
                        }
                }
        }

        /* check pending CNAKS */
        if (cnak_pending) {
                /* CNAk processing when rxfifo empty only */
                if (readl(&dev->regs->sts) & AMD_BIT(UDC_DEVSTS_RXFIFO_EMPTY))
                        udc_process_cnak_queue(dev);
        }

finished:
        return ret_val;
}

/* Interrupt handler for Control IN traffic */
static irqreturn_t udc_control_in_isr(struct udc *dev)
{
        irqreturn_t ret_val = IRQ_NONE;
        u32 tmp;
        struct udc_ep *ep;
        struct udc_request *req;
        unsigned len;

        ep = &dev->ep[UDC_EP0IN_IX];

        /* clear irq */
        writel(AMD_BIT(UDC_EPINT_IN_EP0), &dev->regs->ep_irqsts);

        tmp = readl(&dev->ep[UDC_EP0IN_IX].regs->sts);
        /* DMA completion */
        if (tmp & AMD_BIT(UDC_EPSTS_TDC)) {
                VDBG(dev, "isr: TDC clear\n");
                ret_val = IRQ_HANDLED;

                /* clear TDC bit */
                writel(AMD_BIT(UDC_EPSTS_TDC),
                                &dev->ep[UDC_EP0IN_IX].regs->sts);

        /* status reg has IN bit set ? */
        } else if (tmp & AMD_BIT(UDC_EPSTS_IN)) {
                ret_val = IRQ_HANDLED;

                if (ep->dma) {
                        /* clear IN bit */
                        writel(AMD_BIT(UDC_EPSTS_IN),
                                &dev->ep[UDC_EP0IN_IX].regs->sts);
                }
                if (dev->stall_ep0in) {
                        DBG(dev, "stall ep0in\n");
                        /* halt ep0in */
                        tmp = readl(&ep->regs->ctl);
                        tmp |= AMD_BIT(UDC_EPCTL_S);
                        writel(tmp, &ep->regs->ctl);
                } else {
                        if (!list_empty(&ep->queue)) {
                                /* next request */
                                req = list_entry(ep->queue.next,
                                                struct udc_request, queue);

                                if (ep->dma) {
                                        /* write desc pointer */
                                        writel(req->td_phys, &ep->regs->desptr);
                                        /* set HOST READY */
                                        req->td_data->status =
                                                AMD_ADDBITS(
                                                req->td_data->status,
                                                UDC_DMA_STP_STS_BS_HOST_READY,
                                                UDC_DMA_STP_STS_BS);

                                        /* set poll demand bit */
                                        tmp =
                                        readl(&dev->ep[UDC_EP0IN_IX].regs->ctl);
                                        tmp |= AMD_BIT(UDC_EPCTL_P);
                                        writel(tmp,
                                        &dev->ep[UDC_EP0IN_IX].regs->ctl);

                                        /* all bytes will be transferred */
                                        req->req.actual = req->req.length;

                                        /* complete req */
                                        complete_req(ep, req, 0);

                                } else {
                                        /* write fifo */
                                        udc_txfifo_write(ep, &req->req);

                                        /* lengh bytes transferred */
                                        len = req->req.length - req->req.actual;
                                        if (len > ep->ep.maxpacket)
                                                len = ep->ep.maxpacket;

                                        req->req.actual += len;
                                        if (req->req.actual == req->req.length
                                                || (len != ep->ep.maxpacket)) {
                                                /* complete req */
                                                complete_req(ep, req, 0);
                                        }
                                }

                        }
                }
                ep->halted = 0;
                dev->stall_ep0in = 0;
                if (!ep->dma) {
                        /* clear IN bit */
                        writel(AMD_BIT(UDC_EPSTS_IN),
                                &dev->ep[UDC_EP0IN_IX].regs->sts);
                }
        }

        return ret_val;
}


/* Interrupt handler for global device events */
static irqreturn_t udc_dev_isr(struct udc *dev, u32 dev_irq)
__releases(dev->lock)
__acquires(dev->lock)
{
        irqreturn_t ret_val = IRQ_NONE;
        u32 tmp;
        u32 cfg;
        struct udc_ep *ep;
        u16 i;
        u8 udc_csr_epix;

        /* SET_CONFIG irq ? */
        if (dev_irq & AMD_BIT(UDC_DEVINT_SC)) {
                ret_val = IRQ_HANDLED;

                /* read config value */
                tmp = readl(&dev->regs->sts);
                cfg = AMD_GETBITS(tmp, UDC_DEVSTS_CFG);
                DBG(dev, "SET_CONFIG interrupt: config=%d\n", cfg);
                dev->cur_config = cfg;
                dev->set_cfg_not_acked = 1;

                /* make usb request for gadget driver */
                memset(&setup_data, 0 , sizeof(union udc_setup_data));
                setup_data.request.bRequest = USB_REQ_SET_CONFIGURATION;
                setup_data.request.wValue = cpu_to_le16(dev->cur_config);

                /* programm the NE registers */
                for (i = 0; i < UDC_EP_NUM; i++) {
                        ep = &dev->ep[i];
                        if (ep->in) {

                                /* ep ix in UDC CSR register space */
                                udc_csr_epix = ep->num;


                        /* OUT ep */
                        } else {
                                /* ep ix in UDC CSR register space */
                                udc_csr_epix = ep->num - UDC_CSR_EP_OUT_IX_OFS;
                        }

                        tmp = readl(&dev->csr->ne[udc_csr_epix]);
                        /* ep cfg */
                        tmp = AMD_ADDBITS(tmp, ep->dev->cur_config,
                                                UDC_CSR_NE_CFG);
                        /* write reg */
                        writel(tmp, &dev->csr->ne[udc_csr_epix]);

                        /* clear stall bits */
                        ep->halted = 0;
                        tmp = readl(&ep->regs->ctl);
                        tmp = tmp & AMD_CLEAR_BIT(UDC_EPCTL_S);
                        writel(tmp, &ep->regs->ctl);
                }
                /* call gadget zero with setup data received */
                spin_unlock(&dev->lock);
                tmp = dev->driver->setup(&dev->gadget, &setup_data.request);
                spin_lock(&dev->lock);

        } /* SET_INTERFACE ? */
        if (dev_irq & AMD_BIT(UDC_DEVINT_SI)) {
                ret_val = IRQ_HANDLED;

                dev->set_cfg_not_acked = 1;
                /* read interface and alt setting values */
                tmp = readl(&dev->regs->sts);
                dev->cur_alt = AMD_GETBITS(tmp, UDC_DEVSTS_ALT);
                dev->cur_intf = AMD_GETBITS(tmp, UDC_DEVSTS_INTF);

                /* make usb request for gadget driver */
                memset(&setup_data, 0 , sizeof(union udc_setup_data));
                setup_data.request.bRequest = USB_REQ_SET_INTERFACE;
                setup_data.request.bRequestType = USB_RECIP_INTERFACE;
                setup_data.request.wValue = cpu_to_le16(dev->cur_alt);
                setup_data.request.wIndex = cpu_to_le16(dev->cur_intf);

                DBG(dev, "SET_INTERFACE interrupt: alt=%d intf=%d\n",
                                dev->cur_alt, dev->cur_intf);

                /* programm the NE registers */
                for (i = 0; i < UDC_EP_NUM; i++) {
                        ep = &dev->ep[i];
                        if (ep->in) {

                                /* ep ix in UDC CSR register space */
                                udc_csr_epix = ep->num;


                        /* OUT ep */
                        } else {
                                /* ep ix in UDC CSR register space */
                                udc_csr_epix = ep->num - UDC_CSR_EP_OUT_IX_OFS;
                        }

                        /* UDC CSR reg */
                        /* set ep values */
                        tmp = readl(&dev->csr->ne[udc_csr_epix]);
                        /* ep interface */
                        tmp = AMD_ADDBITS(tmp, ep->dev->cur_intf,
                                                UDC_CSR_NE_INTF);
                        /* tmp = AMD_ADDBITS(tmp, 2, UDC_CSR_NE_INTF); */
                        /* ep alt */
                        tmp = AMD_ADDBITS(tmp, ep->dev->cur_alt,
                                                UDC_CSR_NE_ALT);
                        /* write reg */
                        writel(tmp, &dev->csr->ne[udc_csr_epix]);

                        /* clear stall bits */
                        ep->halted = 0;
                        tmp = readl(&ep->regs->ctl);
                        tmp = tmp & AMD_CLEAR_BIT(UDC_EPCTL_S);
                        writel(tmp, &ep->regs->ctl);
                }

                /* call gadget zero with setup data received */
                spin_unlock(&dev->lock);
                tmp = dev->driver->setup(&dev->gadget, &setup_data.request);
                spin_lock(&dev->lock);

        } /* USB reset */
        if (dev_irq & AMD_BIT(UDC_DEVINT_UR)) {
                DBG(dev, "USB Reset interrupt\n");
                ret_val = IRQ_HANDLED;

                /* allow soft reset when suspend occurs */
                soft_reset_occured = 0;

                dev->waiting_zlp_ack_ep0in = 0;
                dev->set_cfg_not_acked = 0;

                /* mask not needed interrupts */
                udc_mask_unused_interrupts(dev);

                /* call gadget to resume and reset configs etc. */
                spin_unlock(&dev->lock);
                if (dev->sys_suspended && dev->driver->resume) {
                        dev->driver->resume(&dev->gadget);
                        dev->sys_suspended = 0;
                }
                usb_gadget_udc_reset(&dev->gadget, dev->driver);
                spin_lock(&dev->lock);

                /* disable ep0 to empty req queue */
                empty_req_queue(&dev->ep[UDC_EP0IN_IX]);
                ep_init(dev->regs, &dev->ep[UDC_EP0IN_IX]);

                /* soft reset when rxfifo not empty */
                tmp = readl(&dev->regs->sts);
                if (!(tmp & AMD_BIT(UDC_DEVSTS_RXFIFO_EMPTY))
                                && !soft_reset_after_usbreset_occured) {
                        udc_soft_reset(dev);
                        soft_reset_after_usbreset_occured++;
                }

                /*
                 * DMA reset to kill potential old DMA hw hang,
                 * POLL bit is already reset by ep_init() through
                 * disconnect()
                 */
                DBG(dev, "DMA machine reset\n");
                tmp = readl(&dev->regs->cfg);
                writel(tmp | AMD_BIT(UDC_DEVCFG_DMARST), &dev->regs->cfg);
                writel(tmp, &dev->regs->cfg);

                /* put into initial config */
                udc_basic_init(dev);

                /* enable device setup interrupts */
                udc_enable_dev_setup_interrupts(dev);

                /* enable suspend interrupt */
                tmp = readl(&dev->regs->irqmsk);
                tmp &= AMD_UNMASK_BIT(UDC_DEVINT_US);
                writel(tmp, &dev->regs->irqmsk);

        } /* USB suspend */
        if (dev_irq & AMD_BIT(UDC_DEVINT_US)) {
                DBG(dev, "USB Suspend interrupt\n");
                ret_val = IRQ_HANDLED;
                if (dev->driver->suspend) {
                        spin_unlock(&dev->lock);
                        dev->sys_suspended = 1;
                        dev->driver->suspend(&dev->gadget);
                        spin_lock(&dev->lock);
                }
        } /* new speed ? */
        if (dev_irq & AMD_BIT(UDC_DEVINT_ENUM)) {
                DBG(dev, "ENUM interrupt\n");
                ret_val = IRQ_HANDLED;
                soft_reset_after_usbreset_occured = 0;

                /* disable ep0 to empty req queue */
                empty_req_queue(&dev->ep[UDC_EP0IN_IX]);
                ep_init(dev->regs, &dev->ep[UDC_EP0IN_IX]);

                /* link up all endpoints */
                udc_setup_endpoints(dev);
                dev_info(dev->dev, "Connect: %s\n",
                         usb_speed_string(dev->gadget.speed));

                /* init ep 0 */
                activate_control_endpoints(dev);

                /* enable ep0 interrupts */
                udc_enable_ep0_interrupts(dev);
        }
        /* session valid change interrupt */
        if (dev_irq & AMD_BIT(UDC_DEVINT_SVC)) {
                DBG(dev, "USB SVC interrupt\n");
                ret_val = IRQ_HANDLED;

                /* check that session is not valid to detect disconnect */
                tmp = readl(&dev->regs->sts);
                if (!(tmp & AMD_BIT(UDC_DEVSTS_SESSVLD))) {
                        /* disable suspend interrupt */
                        tmp = readl(&dev->regs->irqmsk);
                        tmp |= AMD_BIT(UDC_DEVINT_US);
                        writel(tmp, &dev->regs->irqmsk);
                        DBG(dev, "USB Disconnect (session valid low)\n");
                        /* cleanup on disconnect */
                        usb_disconnect(udc);
                }

        }

        return ret_val;
}

/* Interrupt Service Routine, see Linux Kernel Doc for parameters */
irqreturn_t udc_irq(int irq, void *pdev)
{
        struct udc *dev = pdev;
        u32 reg;