/*
 * Copyright (C) 2011 Marvell International Ltd. All rights reserved.
 * Author: Chao Xie <chao.xie@marvell.com>
 *         Neil Zhang <zhangwm@marvell.com>
 *
 * This program is free software; you can redistribute  it and/or modify it
 * under  the terms of  the GNU General  Public License as published by the
 * Free Software Foundation;  either version 2 of the  License, or (at your
 * option) any later version.
 */

#include <linux/module.h>
#include <linux/pci.h>
#include <linux/dma-mapping.h>
#include <linux/dmapool.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/err.h>
#include <linux/init.h>
#include <linux/timer.h>
#include <linux/list.h>
#include <linux/interrupt.h>
#include <linux/moduleparam.h>
#include <linux/device.h>
#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>
#include <linux/usb/otg.h>
#include <linux/pm.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/platform_device.h>
#include <linux/clk.h>
#include <linux/platform_data/mv_usb.h>
#include <asm/unaligned.h>

#include "mv_udc.h"

#define DRIVER_DESC             "Marvell PXA USB Device Controller driver"
#define DRIVER_VERSION          "8 Nov 2010"

#define ep_dir(ep)      (((ep)->ep_num == 0) ? \
                                ((ep)->udc->ep0_dir) : ((ep)->direction))

/* timeout value -- usec */
#define RESET_TIMEOUT           10000
#define FLUSH_TIMEOUT           10000
#define EPSTATUS_TIMEOUT        10000
#define PRIME_TIMEOUT           10000
#define READSAFE_TIMEOUT        1000

#define LOOPS_USEC_SHIFT        1
#define LOOPS_USEC              (1 << LOOPS_USEC_SHIFT)
#define LOOPS(timeout)          ((timeout) >> LOOPS_USEC_SHIFT)

static DECLARE_COMPLETION(release_done);

static const char driver_name[] = "mv_udc";
static const char driver_desc[] = DRIVER_DESC;

static void nuke(struct mv_ep *ep, int status);
static void stop_activity(struct mv_udc *udc, struct usb_gadget_driver *driver);

/* for endpoint 0 operations */
static const struct usb_endpoint_descriptor mv_ep0_desc = {
        .bLength =              USB_DT_ENDPOINT_SIZE,
        .bDescriptorType =      USB_DT_ENDPOINT,
        .bEndpointAddress =     0,
        .bmAttributes =         USB_ENDPOINT_XFER_CONTROL,
        .wMaxPacketSize =       EP0_MAX_PKT_SIZE,
};

static void ep0_reset(struct mv_udc *udc)
{
        struct mv_ep *ep;
        u32 epctrlx;
        int i = 0;

        /* ep0 in and out */
        for (i = 0; i < 2; i++) {
                ep = &udc->eps[i];
                ep->udc = udc;

                /* ep0 dQH */
                ep->dqh = &udc->ep_dqh[i];

                /* configure ep0 endpoint capabilities in dQH */
                ep->dqh->max_packet_length =
                        (EP0_MAX_PKT_SIZE << EP_QUEUE_HEAD_MAX_PKT_LEN_POS)
                        | EP_QUEUE_HEAD_IOS;

                ep->dqh->next_dtd_ptr = EP_QUEUE_HEAD_NEXT_TERMINATE;

                epctrlx = readl(&udc->op_regs->epctrlx[0]);
                if (i) {        /* TX */
                        epctrlx |= EPCTRL_TX_ENABLE
                                | (USB_ENDPOINT_XFER_CONTROL
                                        << EPCTRL_TX_EP_TYPE_SHIFT);

                } else {        /* RX */
                        epctrlx |= EPCTRL_RX_ENABLE
                                | (USB_ENDPOINT_XFER_CONTROL
                                        << EPCTRL_RX_EP_TYPE_SHIFT);
                }

                writel(epctrlx, &udc->op_regs->epctrlx[0]);
        }
}

/* protocol ep0 stall, will automatically be cleared on new transaction */
static void ep0_stall(struct mv_udc *udc)
{
        u32     epctrlx;

        /* set TX and RX to stall */
        epctrlx = readl(&udc->op_regs->epctrlx[0]);
        epctrlx |= EPCTRL_RX_EP_STALL | EPCTRL_TX_EP_STALL;
        writel(epctrlx, &udc->op_regs->epctrlx[0]);

        /* update ep0 state */
        udc->ep0_state = WAIT_FOR_SETUP;
        udc->ep0_dir = EP_DIR_OUT;
}

static int process_ep_req(struct mv_udc *udc, int index,
        struct mv_req *curr_req)
{
        struct mv_dtd   *curr_dtd;
        struct mv_dqh   *curr_dqh;
        int td_complete, actual, remaining_length;
        int i, direction;
        int retval = 0;
        u32 errors;
        u32 bit_pos;

        curr_dqh = &udc->ep_dqh[index];
        direction = index % 2;

        curr_dtd = curr_req->head;
        td_complete = 0;
        actual = curr_req->req.length;

        for (i = 0; i < curr_req->dtd_count; i++) {
                if (curr_dtd->size_ioc_sts & DTD_STATUS_ACTIVE) {
                        dev_dbg(&udc->dev->dev, "%s, dTD not completed\n",
                                udc->eps[index].name);
                        return 1;
                }

                errors = curr_dtd->size_ioc_sts & DTD_ERROR_MASK;
                if (!errors) {
                        remaining_length =
                                (curr_dtd->size_ioc_sts & DTD_PACKET_SIZE)
                                        >> DTD_LENGTH_BIT_POS;
                        actual -= remaining_length;

                        if (remaining_length) {
                                if (direction) {
                                        dev_dbg(&udc->dev->dev,
                                                "TX dTD remains data\n");
                                        retval = -EPROTO;
                                        break;
                                } else
                                        break;
                        }
                } else {
                        dev_info(&udc->dev->dev,
                                "complete_tr error: ep=%d %s: error = 0x%x\n",
                                index >> 1, direction ? "SEND" : "RECV",
                                errors);
                        if (errors & DTD_STATUS_HALTED) {
                                /* Clear the errors and Halt condition */
                                curr_dqh->size_ioc_int_sts &= ~errors;
                                retval = -EPIPE;
                        } else if (errors & DTD_STATUS_DATA_BUFF_ERR) {
                                retval = -EPROTO;
                        } else if (errors & DTD_STATUS_TRANSACTION_ERR) {
                                retval = -EILSEQ;
                        }
                }
                if (i != curr_req->dtd_count - 1)
                        curr_dtd = (struct mv_dtd *)curr_dtd->next_dtd_virt;
        }
        if (retval)
                return retval;

        if (direction == EP_DIR_OUT)
                bit_pos = 1 << curr_req->ep->ep_num;
        else
                bit_pos = 1 << (16 + curr_req->ep->ep_num);

        while ((curr_dqh->curr_dtd_ptr == curr_dtd->td_dma)) {
                if (curr_dtd->dtd_next == EP_QUEUE_HEAD_NEXT_TERMINATE) {
                        while (readl(&udc->op_regs->epstatus) & bit_pos)
                                udelay(1);
                        break;
                }
                udelay(1);
        }

        curr_req->req.actual = actual;

        return 0;
}

/*
 * done() - retire a request; caller blocked irqs
 * @status : request status to be set, only works when
 * request is still in progress.
 */
static void done(struct mv_ep *ep, struct mv_req *req, int status)
        __releases(&ep->udc->lock)
        __acquires(&ep->udc->lock)
{
        struct mv_udc *udc = NULL;
        unsigned char stopped = ep->stopped;
        struct mv_dtd *curr_td, *next_td;
        int j;

        udc = (struct mv_udc *)ep->udc;
        /* Removed the req from fsl_ep->queue */
        list_del_init(&req->queue);

        /* req.status should be set as -EINPROGRESS in ep_queue() */
        if (req->req.status == -EINPROGRESS)
                req->req.status = status;
        else
                status = req->req.status;

        /* Free dtd for the request */
        next_td = req->head;
        for (j = 0; j < req->dtd_count; j++) {
                curr_td = next_td;
                if (j != req->dtd_count - 1)
                        next_td = curr_td->next_dtd_virt;
                dma_pool_free(udc->dtd_pool, curr_td, curr_td->td_dma);
        }

        usb_gadget_unmap_request(&udc->gadget, &req->req, ep_dir(ep));

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

        ep->stopped = 1;

        spin_unlock(&ep->udc->lock);
        /*
         * complete() is from gadget layer,
         * eg fsg->bulk_in_complete()
         */
        if (req->req.complete)
                req->req.complete(&ep->ep, &req->req);

        spin_lock(&ep->udc->lock);
        ep->stopped = stopped;
}

static int queue_dtd(struct mv_ep *ep, struct mv_req *req)
{
        struct mv_udc *udc;
        struct mv_dqh *dqh;
        u32 bit_pos, direction;
        u32 usbcmd, epstatus;
        unsigned int loops;
        int retval = 0;

        udc = ep->udc;
        direction = ep_dir(ep);
        dqh = &(udc->ep_dqh[ep->ep_num * 2 + direction]);
        bit_pos = 1 << (((direction == EP_DIR_OUT) ? 0 : 16) + ep->ep_num);

        /* check if the pipe is empty */
        if (!(list_empty(&ep->queue))) {
                struct mv_req *lastreq;
                lastreq = list_entry(ep->queue.prev, struct mv_req, queue);
                lastreq->tail->dtd_next =
                        req->head->td_dma & EP_QUEUE_HEAD_NEXT_POINTER_MASK;

                wmb();

                if (readl(&udc->op_regs->epprime) & bit_pos)
                        goto done;

                loops = LOOPS(READSAFE_TIMEOUT);
                while (1) {
                        /* start with setting the semaphores */
                        usbcmd = readl(&udc->op_regs->usbcmd);
                        usbcmd |= USBCMD_ATDTW_TRIPWIRE_SET;
                        writel(usbcmd, &udc->op_regs->usbcmd);

                        /* read the endpoint status */
                        epstatus = readl(&udc->op_regs->epstatus) & bit_pos;

                        /*
                         * Reread the ATDTW semaphore bit to check if it is
                         * cleared. When hardware see a hazard, it will clear
                         * the bit or else we remain set to 1 and we can
                         * proceed with priming of endpoint if not already
                         * primed.
                         */
                        if (readl(&udc->op_regs->usbcmd)
                                & USBCMD_ATDTW_TRIPWIRE_SET)
                                break;

                        loops--;
                        if (loops == 0) {
                                dev_err(&udc->dev->dev,
                                        "Timeout for ATDTW_TRIPWIRE...\n");
                                retval = -ETIME;
                                goto done;
                        }
                        udelay(LOOPS_USEC);
                }

                /* Clear the semaphore */
                usbcmd = readl(&udc->op_regs->usbcmd);
                usbcmd &= USBCMD_ATDTW_TRIPWIRE_CLEAR;
                writel(usbcmd, &udc->op_regs->usbcmd);

                if (epstatus)
                        goto done;
        }

        /* Write dQH next pointer and terminate bit to 0 */
        dqh->next_dtd_ptr = req->head->td_dma
                                & EP_QUEUE_HEAD_NEXT_POINTER_MASK;

        /* clear active and halt bit, in case set from a previous error */
        dqh->size_ioc_int_sts &= ~(DTD_STATUS_ACTIVE | DTD_STATUS_HALTED);

        /* Ensure that updates to the QH will occure before priming. */
        wmb();

        /* Prime the Endpoint */
        writel(bit_pos, &udc->op_regs->epprime);

done:
        return retval;
}

static struct mv_dtd *build_dtd(struct mv_req *req, unsigned *length,
                dma_addr_t *dma, int *is_last)
{
        struct mv_dtd *dtd;
        struct mv_udc *udc;
        struct mv_dqh *dqh;
        u32 temp, mult = 0;

        /* how big will this transfer be? */
        if (usb_endpoint_xfer_isoc(req->ep->ep.desc)) {
                dqh = req->ep->dqh;
                mult = (dqh->max_packet_length >> EP_QUEUE_HEAD_MULT_POS)
                                & 0x3;
                *length = min(req->req.length - req->req.actual,
                                (unsigned)(mult * req->ep->ep.maxpacket));
        } else
                *length = min(req->req.length - req->req.actual,
                                (unsigned)EP_MAX_LENGTH_TRANSFER);

        udc = req->ep->udc;

        /*
         * Be careful that no _GFP_HIGHMEM is set,
         * or we can not use dma_to_virt
         */
        dtd = dma_pool_alloc(udc->dtd_pool, GFP_ATOMIC, dma);
        if (dtd == NULL)
                return dtd;

        dtd->td_dma = *dma;
        /* initialize buffer page pointers */
        temp = (u32)(req->req.dma + req->req.actual);
        dtd->buff_ptr0 = cpu_to_le32(temp);
        temp &= ~0xFFF;
        dtd->buff_ptr1 = cpu_to_le32(temp + 0x1000);
        dtd->buff_ptr2 = cpu_to_le32(temp + 0x2000);
        dtd->buff_ptr3 = cpu_to_le32(temp + 0x3000);
        dtd->buff_ptr4 = cpu_to_le32(temp + 0x4000);

        req->req.actual += *length;

        /* zlp is needed if req->req.zero is set */
        if (req->req.zero) {
                if (*length == 0 || (*length % req->ep->ep.maxpacket) != 0)
                        *is_last = 1;
                else
                        *is_last = 0;
        } else if (req->req.length == req->req.actual)
                *is_last = 1;
        else
                *is_last = 0;

        /* Fill in the transfer size; set active bit */
        temp = ((*length << DTD_LENGTH_BIT_POS) | DTD_STATUS_ACTIVE);

        /* Enable interrupt for the last dtd of a request */
        if (*is_last && !req->req.no_interrupt)
                temp |= DTD_IOC;

        temp |= mult << 10;

        dtd->size_ioc_sts = temp;

        mb();

        return dtd;
}

/* generate dTD linked list for a request */
static int req_to_dtd(struct mv_req *req)
{
        unsigned count;
        int is_last, is_first = 1;
        struct mv_dtd *dtd, *last_dtd = NULL;
        struct mv_udc *udc;
        dma_addr_t dma;

        udc = req->ep->udc;

        do {
                dtd = build_dtd(req, &count, &dma, &is_last);
                if (dtd == NULL)
                        return -ENOMEM;

                if (is_first) {
                        is_first = 0;
                        req->head = dtd;
                } else {
                        last_dtd->dtd_next = dma;
                        last_dtd->next_dtd_virt = dtd;
                }
                last_dtd = dtd;
                req->dtd_count++;
        } while (!is_last);

        /* set terminate bit to 1 for the last dTD */
        dtd->dtd_next = DTD_NEXT_TERMINATE;

        req->tail = dtd;

        return 0;
}

static int mv_ep_enable(struct usb_ep *_ep,
                const struct usb_endpoint_descriptor *desc)
{
        struct mv_udc *udc;
        struct mv_ep *ep;
        struct mv_dqh *dqh;
        u16 max = 0;
        u32 bit_pos, epctrlx, direction;
        unsigned char zlt = 0, ios = 0, mult = 0;
        unsigned long flags;

        ep = container_of(_ep, struct mv_ep, ep);
        udc = ep->udc;

        if (!_ep || !desc
                        || desc->bDescriptorType != USB_DT_ENDPOINT)
                return -EINVAL;

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

        direction = ep_dir(ep);
        max = usb_endpoint_maxp(desc);

        /*
         * disable HW zero length termination select
         * driver handles zero length packet through req->req.zero
         */
        zlt = 1;

        bit_pos = 1 << ((direction == EP_DIR_OUT ? 0 : 16) + ep->ep_num);

        /* Check if the Endpoint is Primed */
        if ((readl(&udc->op_regs->epprime) & bit_pos)
                || (readl(&udc->op_regs->epstatus) & bit_pos)) {
                dev_info(&udc->dev->dev,
                        "ep=%d %s: Init ERROR: ENDPTPRIME=0x%x,"
                        " ENDPTSTATUS=0x%x, bit_pos=0x%x\n",
                        (unsigned)ep->ep_num, direction ? "SEND" : "RECV",
                        (unsigned)readl(&udc->op_regs->epprime),
                        (unsigned)readl(&udc->op_regs->epstatus),
                        (unsigned)bit_pos);
                goto en_done;
        }
        /* Set the max packet length, interrupt on Setup and Mult fields */
        switch (desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) {
        case USB_ENDPOINT_XFER_BULK:
                zlt = 1;
                mult = 0;
                break;
        case USB_ENDPOINT_XFER_CONTROL:
                ios = 1;
        case USB_ENDPOINT_XFER_INT:
                mult = 0;
                break;
        case USB_ENDPOINT_XFER_ISOC:
                /* Calculate transactions needed for high bandwidth iso */
                mult = (unsigned char)(1 + ((max >> 11) & 0x03));
                max = max & 0x7ff;      /* bit 0~10 */
                /* 3 transactions at most */
                if (mult > 3)
                        goto en_done;
                break;
        default:
                goto en_done;
        }

        spin_lock_irqsave(&udc->lock, flags);
        /* Get the endpoint queue head address */
        dqh = ep->dqh;
        dqh->max_packet_length = (max << EP_QUEUE_HEAD_MAX_PKT_LEN_POS)
                | (mult << EP_QUEUE_HEAD_MULT_POS)
                | (zlt ? EP_QUEUE_HEAD_ZLT_SEL : 0)
                | (ios ? EP_QUEUE_HEAD_IOS : 0);
        dqh->next_dtd_ptr = 1;
        dqh->size_ioc_int_sts = 0;

        ep->ep.maxpacket = max;
        ep->ep.desc = desc;
        ep->stopped = 0;

        /* Enable the endpoint for Rx or Tx and set the endpoint type */
        epctrlx = readl(&udc->op_regs->epctrlx[ep->ep_num]);
        if (direction == EP_DIR_IN) {
                epctrlx &= ~EPCTRL_TX_ALL_MASK;
                epctrlx |= EPCTRL_TX_ENABLE | EPCTRL_TX_DATA_TOGGLE_RST
                        | ((desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
                                << EPCTRL_TX_EP_TYPE_SHIFT);
        } else {
                epctrlx &= ~EPCTRL_RX_ALL_MASK;
                epctrlx |= EPCTRL_RX_ENABLE | EPCTRL_RX_DATA_TOGGLE_RST
                        | ((desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
                                << EPCTRL_RX_EP_TYPE_SHIFT);
        }
        writel(epctrlx, &udc->op_regs->epctrlx[ep->ep_num]);

        /*
         * Implement Guideline (GL# USB-7) The unused endpoint type must
         * be programmed to bulk.
         */
        epctrlx = readl(&udc->op_regs->epctrlx[ep->ep_num]);
        if ((epctrlx & EPCTRL_RX_ENABLE) == 0) {
                epctrlx |= (USB_ENDPOINT_XFER_BULK
                                << EPCTRL_RX_EP_TYPE_SHIFT);
                writel(epctrlx, &udc->op_regs->epctrlx[ep->ep_num]);
        }

        epctrlx = readl(&udc->op_regs->epctrlx[ep->ep_num]);
        if ((epctrlx & EPCTRL_TX_ENABLE) == 0) {
                epctrlx |= (USB_ENDPOINT_XFER_BULK
                                << EPCTRL_TX_EP_TYPE_SHIFT);
                writel(epctrlx, &udc->op_regs->epctrlx[ep->ep_num]);
        }

        spin_unlock_irqrestore(&udc->lock, flags);

        return 0;
en_done:
        return -EINVAL;
}

static int  mv_ep_disable(struct usb_ep *_ep)
{
        struct mv_udc *udc;
        struct mv_ep *ep;
        struct mv_dqh *dqh;
        u32 bit_pos, epctrlx, direction;
        unsigned long flags;

        ep = container_of(_ep, struct mv_ep, ep);
        if ((_ep == NULL) || !ep->ep.desc)
                return -EINVAL;

        udc = ep->udc;

        /* Get the endpoint queue head address */
        dqh = ep->dqh;

        spin_lock_irqsave(&udc->lock, flags);

        direction = ep_dir(ep);
        bit_pos = 1 << ((direction == EP_DIR_OUT ? 0 : 16) + ep->ep_num);

        /* Reset the max packet length and the interrupt on Setup */
        dqh->max_packet_length = 0;

        /* Disable the endpoint for Rx or Tx and reset the endpoint type */
        epctrlx = readl(&udc->op_regs->epctrlx[ep->ep_num]);
        epctrlx &= ~((direction == EP_DIR_IN)
                        ? (EPCTRL_TX_ENABLE | EPCTRL_TX_TYPE)
                        : (EPCTRL_RX_ENABLE | EPCTRL_RX_TYPE));
        writel(epctrlx, &udc->op_regs->epctrlx[ep->ep_num]);

        /* nuke all pending requests (does flush) */
        nuke(ep, -ESHUTDOWN);

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

        spin_unlock_irqrestore(&udc->lock, flags);

        return 0;
}

static struct usb_request *
mv_alloc_request(struct usb_ep *_ep, gfp_t gfp_flags)
{
        struct mv_req *req = NULL;

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

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

        return &req->req;
}

static void mv_free_request(struct usb_ep *_ep, struct usb_request *_req)
{
        struct mv_req *req = NULL;

        req = container_of(_req, struct mv_req, req);

        if (_req)
                kfree(req);
}

static void mv_ep_fifo_flush(struct usb_ep *_ep)
{
        struct mv_udc *udc;
        u32 bit_pos, direction;
        struct mv_ep *ep;
        unsigned int loops;

        if (!_ep)
                return;

        ep = container_of(_ep, struct mv_ep, ep);
        if (!ep->ep.desc)
                return;

        udc = ep->udc;
        direction = ep_dir(ep);

        if (ep->ep_num == 0)
                bit_pos = (1 << 16) | 1;
        else if (direction == EP_DIR_OUT)
                bit_pos = 1 << ep->ep_num;
        else
                bit_pos = 1 << (16 + ep->ep_num);

        loops = LOOPS(EPSTATUS_TIMEOUT);
        do {
                unsigned int inter_loops;

                if (loops == 0) {
                        dev_err(&udc->dev->dev,
                                "TIMEOUT for ENDPTSTATUS=0x%x, bit_pos=0x%x\n",
                                (unsigned)readl(&udc->op_regs->epstatus),
                                (unsigned)bit_pos);
                        return;
                }
                /* Write 1 to the Flush register */
                writel(bit_pos, &udc->op_regs->epflush);

                /* Wait until flushing completed */
                inter_loops = LOOPS(FLUSH_TIMEOUT);
                while (readl(&udc->op_regs->epflush)) {
                        /*
                         * ENDPTFLUSH bit should be cleared to indicate this
                         * operation is complete
                         */
                        if (inter_loops == 0) {
                                dev_err(&udc->dev->dev,
                                        "TIMEOUT for ENDPTFLUSH=0x%x,"
                                        "bit_pos=0x%x\n",
                                        (unsigned)readl(&udc->op_regs->epflush),
                                        (unsigned)bit_pos);
                                return;
                        }
                        inter_loops--;
                        udelay(LOOPS_USEC);
                }
                loops--;
        } while (readl(&udc->op_regs->epstatus) & bit_pos);
}

/* queues (submits) an I/O request to an endpoint */
static int
mv_ep_queue(struct usb_ep *_ep, struct usb_request *_req, gfp_t gfp_flags)
{
        struct mv_ep *ep = container_of(_ep, struct mv_ep, ep);
        struct mv_req *req = container_of(_req, struct mv_req, req);
        struct mv_udc *udc = ep->udc;
        unsigned long flags;
        int retval;

        /* catch various bogus parameters */
        if (!_req || !req->req.complete || !req->req.buf
                        || !list_empty(&req->queue)) {
                dev_err(&udc->dev->dev, "%s, bad params", __func__);
                return -EINVAL;
        }
        if (unlikely(!_ep || !ep->ep.desc)) {
                dev_err(&udc->dev->dev, "%s, bad ep", __func__);
                return -EINVAL;
        }

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

        req->ep = ep;

        /* map virtual address to hardware */
        retval = usb_gadget_map_request(&udc->gadget, _req, ep_dir(ep));
        if (retval)
                return retval;

        req->req.status = -EINPROGRESS;
        req->req.actual = 0;
        req->dtd_count = 0;

        spin_lock_irqsave(&udc->lock, flags);

        /* build dtds and push them to device queue */
        if (!req_to_dtd(req)) {
                retval = queue_dtd(ep, req);
                if (retval) {
                        spin_unlock_irqrestore(&udc->lock, flags);
                        dev_err(&udc->dev->dev, "Failed to queue dtd\n");
                        goto err_unmap_dma;
                }
        } else {
                spin_unlock_irqrestore(&udc->lock, flags);
                dev_err(&udc->dev->dev, "Failed to dma_pool_alloc\n");
                retval = -ENOMEM;
                goto err_unmap_dma;
        }

        /* Update ep0 state */
        if (ep->ep_num == 0)
                udc->ep0_state = DATA_STATE_XMIT;

        /* irq handler advances the queue */
        list_add_tail(&req->queue, &ep->queue);
        spin_unlock_irqrestore(&udc->lock, flags);

        return 0;

err_unmap_dma:
        usb_gadget_unmap_request(&udc->gadget, _req, ep_dir(ep));

        return retval;
}

static void mv_prime_ep(struct mv_ep *ep, struct mv_req *req)
{
        struct mv_dqh *dqh = ep->dqh;
        u32 bit_pos;

        /* Write dQH next pointer and terminate bit to 0 */
        dqh->next_dtd_ptr = req->head->td_dma
                & EP_QUEUE_HEAD_NEXT_POINTER_MASK;

        /* clear active and halt bit, in case set from a previous error */
        dqh->size_ioc_int_sts &= ~(DTD_STATUS_ACTIVE | DTD_STATUS_HALTED);

        /* Ensure that updates to the QH will occure before priming. */
        wmb();

        bit_pos = 1 << (((ep_dir(ep) == EP_DIR_OUT) ? 0 : 16) + ep->ep_num);

        /* Prime the Endpoint */
        writel(bit_pos, &ep->udc->op_regs->epprime);
}

/* dequeues (cancels, unlinks) an I/O request from an endpoint */
static int mv_ep_dequeue(struct usb_ep *_ep, struct usb_request *_req)
{
        struct mv_ep *ep = container_of(_ep, struct mv_ep, ep);
        struct mv_req *req;
        struct mv_udc *udc = ep->udc;
        unsigned long flags;
        int stopped, ret = 0;
        u32 epctrlx;

        if (!_ep || !_req)
                return -EINVAL;

        spin_lock_irqsave(&ep->udc->lock, flags);
        stopped = ep->stopped;

        /* Stop the ep before we deal with the queue */
        ep->stopped = 1;
        epctrlx = readl(&udc->op_regs->epctrlx[ep->ep_num]);
        if (ep_dir(ep) == EP_DIR_IN)
                epctrlx &= ~EPCTRL_TX_ENABLE;
        else
                epctrlx &= ~EPCTRL_RX_ENABLE;
        writel(epctrlx, &udc->op_regs->epctrlx[ep->ep_num]);

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

        /* The request is in progress, or completed but not dequeued */
        if (ep->queue.next == &req->queue) {
                _req->status = -ECONNRESET;
                mv_ep_fifo_flush(_ep);  /* flush current transfer */

                /* The request isn't the last request in this ep queue */
                if (req->queue.next != &ep->queue) {
                        struct mv_req *next_req;

                        next_req = list_entry(req->queue.next,
                                struct mv_req, queue);

                        /* Point the QH to the first TD of next request */
                        mv_prime_ep(ep, next_req);
                } else {
                        struct mv_dqh *qh;

                        qh = ep->dqh;
                        qh->next_dtd_ptr = 1;
                        qh->size_ioc_int_sts = 0;
                }

                /* The request hasn't been processed, patch up the TD chain */
        } else {
                struct mv_req *prev_req;

                prev_req = list_entry(req->queue.prev, struct mv_req, queue);
                writel(readl(&req->tail->dtd_next),
                                &prev_req->tail->dtd_next);

        }

        done(ep, req, -ECONNRESET);

        /* Enable EP */
out:
        epctrlx = readl(&udc->op_regs->epctrlx[ep->ep_num]);
        if (ep_dir(ep) == EP_DIR_IN)
                epctrlx |= EPCTRL_TX_ENABLE;
        else
                epctrlx |= EPCTRL_RX_ENABLE;
        writel(epctrlx, &udc->op_regs->epctrlx[ep->ep_num]);
        ep->stopped = stopped;

        spin_unlock_irqrestore(&ep->udc->lock, flags);
        return ret;
}

static void ep_set_stall(struct mv_udc *udc, u8 ep_num, u8 direction, int stall)
{
        u32 epctrlx;

        epctrlx = readl(&udc->op_regs->epctrlx[ep_num]);

        if (stall) {
                if (direction == EP_DIR_IN)
                        epctrlx |= EPCTRL_TX_EP_STALL;
                else
                        epctrlx |= EPCTRL_RX_EP_STALL;
        } else {
                if (direction == EP_DIR_IN) {
                        epctrlx &= ~EPCTRL_TX_EP_STALL;
                        epctrlx |= EPCTRL_TX_DATA_TOGGLE_RST;
                } else {
                        epctrlx &= ~EPCTRL_RX_EP_STALL;
                        epctrlx |= EPCTRL_RX_DATA_TOGGLE_RST;
                }
        }
        writel(epctrlx, &udc->op_regs->epctrlx[ep_num]);
}

static int ep_is_stall(struct mv_udc *udc, u8 ep_num, u8 direction)
{
        u32 epctrlx;

        epctrlx = readl(&udc->op_regs->epctrlx[ep_num]);

        if (direction == EP_DIR_OUT)
                return (epctrlx & EPCTRL_RX_EP_STALL) ? 1 : 0;
        else
                return (epctrlx & EPCTRL_TX_EP_STALL) ? 1 : 0;
}

static int mv_ep_set_halt_wedge(struct usb_ep *_ep, int halt, int wedge)
{
        struct mv_ep *ep;
        unsigned long flags = 0;
        int status = 0;
        struct mv_udc *udc;

        ep = container_of(_ep, struct mv_ep, ep);
        udc = ep->udc;
        if (!_ep || !ep->ep.desc) {
                status = -EINVAL;
                goto out;
        }

        if (ep->ep.desc->bmAttributes == USB_ENDPOINT_XFER_ISOC) {
                status = -EOPNOTSUPP;
                goto out;
        }

        /*
         * Attempt to halt IN ep will fail if any transfer requests
         * are still queue
         */
        if (halt && (ep_dir(ep) == EP_DIR_IN) && !list_empty(&ep->queue)) {
                status = -EAGAIN;
                goto out;
        }

        spin_lock_irqsave(&ep->udc->lock, flags);
        ep_set_stall(udc, ep->ep_num, ep_dir(ep), halt);
        if (halt && wedge)
                ep->wedge = 1;
        else if (!halt)
                ep->wedge = 0;
        spin_unlock_irqrestore(&ep->udc->lock, flags);

        if (ep->ep_num == 0) {
                udc->ep0_state = WAIT_FOR_SETUP;
                udc->ep0_dir = EP_DIR_OUT;
        }
out:
        return status;
}

static int mv_ep_set_halt(struct usb_ep *_ep, int halt)
{
        return mv_ep_set_halt_wedge(_ep, halt, 0);
}

static int mv_ep_set_wedge(struct usb_ep *_ep)
{
        return mv_ep_set_halt_wedge(_ep, 1, 1);
}

static struct usb_ep_ops mv_ep_ops = {
        .enable         = mv_ep_enable,
        .disable        = mv_ep_disable,

        .alloc_request  = mv_alloc_request,
        .free_request   = mv_free_request,

        .queue          = mv_ep_queue,
        .dequeue        = mv_ep_dequeue,

        .set_wedge      = mv_ep_set_wedge,
        .set_halt       = mv_ep_set_halt,
        .fifo_flush     = mv_ep_fifo_flush,     /* flush fifo */
};

static void udc_clock_enable(struct mv_udc *udc)
{
        clk_prepare_enable(udc->clk);
}

static void udc_clock_disable(struct mv_udc *udc)
{
        clk_disable_unprepare(udc->clk);
}

static void udc_stop(struct mv_udc *udc)
{
        u32 tmp;

        /* Disable interrupts */
        tmp = readl(&udc->op_regs->usbintr);
        tmp &= ~(USBINTR_INT_EN | USBINTR_ERR_INT_EN |
                USBINTR_PORT_CHANGE_DETECT_EN | USBINTR_RESET_EN);
        writel(tmp, &udc->op_regs->usbintr);

        udc->stopped = 1;

        /* Reset the Run the bit in the command register to stop VUSB */
        tmp = readl(&udc->op_regs->usbcmd);
        tmp &= ~USBCMD_RUN_STOP;
        writel(tmp, &udc->op_regs->usbcmd);

}

static void udc_start(struct mv_udc *udc)
{
        u32 usbintr;

        usbintr = USBINTR_INT_EN | USBINTR_ERR_INT_EN
                | USBINTR_PORT_CHANGE_DETECT_EN
                | USBINTR_RESET_EN | USBINTR_DEVICE_SUSPEND;
        /* Enable interrupts */
        writel(usbintr, &udc->op_regs->usbintr);

        udc->stopped = 0;

        /* Set the Run bit in the command register */
        writel(USBCMD_RUN_STOP, &udc->op_regs->usbcmd);
}

static int udc_reset(struct mv_udc *udc)
{
        unsigned int loops;
        u32 tmp, portsc;

        /* Stop the controller */
        tmp = readl(&udc->op_regs->usbcmd);
        tmp &= ~USBCMD_RUN_STOP;
        writel(tmp, &udc->op_regs->usbcmd);

        /* Reset the controller to get default values */
        writel(USBCMD_CTRL_RESET, &udc->op_regs->usbcmd);

        /* wait for reset to complete */
        loops = LOOPS(RESET_TIMEOUT);
        while (readl(&udc->op_regs->usbcmd) & USBCMD_CTRL_RESET) {
                if (loops == 0) {
                        dev_err(&udc->dev->dev,
                                "Wait for RESET completed TIMEOUT\n");
                        return -ETIMEDOUT;
                }
                loops--;
                udelay(LOOPS_USEC);
        }

        /* set controller to device mode */
        tmp = readl(&udc->op_regs->usbmode);
        tmp |= USBMODE_CTRL_MODE_DEVICE;

        /* turn setup lockout off, require setup tripwire in usbcmd */
        tmp |= USBMODE_SETUP_LOCK_OFF;

        writel(tmp, &udc->op_regs->usbmode);

        writel(0x0, &udc->op_regs->epsetupstat);

        /* Configure the Endpoint List Address */
        writel(udc->ep_dqh_dma & USB_EP_LIST_ADDRESS_MASK,
                &udc->op_regs->eplistaddr);

        portsc = readl(&udc->op_regs->portsc[0]);
        if (readl(&udc->cap_regs->hcsparams) & HCSPARAMS_PPC)
                portsc &= (~PORTSCX_W1C_BITS | ~PORTSCX_PORT_POWER);

        if (udc->force_fs)
                portsc |= PORTSCX_FORCE_FULL_SPEED_CONNECT;
        else
                portsc &= (~PORTSCX_FORCE_FULL_SPEED_CONNECT);

        writel(portsc, &udc->op_regs->portsc[0]);

        tmp = readl(&udc->op_regs->epctrlx[0]);
        tmp &= ~(EPCTRL_TX_EP_STALL | EPCTRL_RX_EP_STALL);
        writel(tmp, &udc->op_regs->epctrlx[0]);

        return 0;
}

static int mv_udc_enable_internal(struct mv_udc *udc)
{
        int retval;

        if (udc->active)
                return 0;

        dev_dbg(&udc->dev->dev, "enable udc\n");
        udc_clock_enable(udc);
        if (udc->pdata->phy_init) {
                retval = udc->pdata->phy_init(udc->phy_regs);
                if (retval) {
                        dev_err(&udc->dev->dev,
                                "init phy error %d\n", retval);
                        udc_clock_disable(udc);
                        return retval;
                }
        }
        udc->active = 1;

        return 0;
}

static int mv_udc_enable(struct mv_udc *udc)
{
        if (udc->clock_gating)
                return mv_udc_enable_internal(udc);

        return 0;
}

static void mv_udc_disable_internal(struct mv_udc *udc)
{
        if (udc->active) {
                dev_dbg(&udc->dev->dev, "disable udc\n");
                if (udc->pdata->phy_deinit)
                        udc->pdata->phy_deinit(udc->phy_regs);
                udc_clock_disable(udc);
                udc->active = 0;
        }
}

static void mv_udc_disable(struct mv_udc *udc)
{
        if (udc->clock_gating)
                mv_udc_disable_internal(udc);
}

static int mv_udc_get_frame(struct usb_gadget *gadget)
{
        struct mv_udc *udc;
        u16     retval;

        if (!gadget)
                return -ENODEV;

        udc = container_of(gadget, struct mv_udc, gadget);

        retval = readl(&udc->op_regs->frindex) & USB_FRINDEX_MASKS;

        return retval;
}

/* Tries to wake up the host connected to this gadget */
static int mv_udc_wakeup(struct usb_gadget *gadget)
{
        struct mv_udc *udc = container_of(gadget, struct mv_udc, gadget);
        u32 portsc;

        /* Remote wakeup feature not enabled by host */
        if (!udc->remote_wakeup)
                return -ENOTSUPP;

        portsc = readl(&udc->op_regs->portsc);
        /* not suspended? */
        if (!(portsc & PORTSCX_PORT_SUSPEND))
                return 0;
        /* trigger force resume */
        portsc |= PORTSCX_PORT_FORCE_RESUME;
        writel(portsc, &udc->op_regs->portsc[0]);
        return 0;
}

static int mv_udc_vbus_session(struct usb_gadget *gadget, int is_active)
{
        struct mv_udc *udc;
        unsigned long flags;
        int retval = 0;

        udc = container_of(gadget, struct mv_udc, gadget);
        spin_lock_irqsave(&udc->lock, flags);

        udc->vbus_active = (is_active != 0);

        dev_dbg(&udc->dev->dev, "%s: softconnect %d, vbus_active %d\n",
                __func__, udc->softconnect, udc->vbus_active);

        if (udc->driver && udc->softconnect && udc->vbus_active) {
                retval = mv_udc_enable(udc);
                if (retval == 0) {
                        /* Clock is disabled, need re-init registers */
                        udc_reset(udc);
                        ep0_reset(udc);
                        udc_start(udc);
                }
        } else if (udc->driver && udc->softconnect) {
                if (!udc->active)
                        goto out;

                /* stop all the transfer in queue*/
                stop_activity(udc, udc->driver);
                udc_stop(udc);
                mv_udc_disable(udc);
        }

out:
        spin_unlock_irqrestore(&udc->lock, flags);
        return retval;
}

static int mv_udc_pullup(struct usb_gadget *gadget, int is_on)
{
        struct mv_udc *udc;
        unsigned long flags;
        int retval = 0;

        udc = container_of(gadget, struct mv_udc, gadget);
        spin_lock_irqsave(&udc->lock, flags);

        udc->softconnect = (is_on != 0);

        dev_dbg(&udc->dev->dev, "%s: softconnect %d, vbus_active %d\n",
                        __func__, udc->softconnect, udc->vbus_active);

        if (udc->driver && udc->softconnect && udc->vbus_active) {
                retval = mv_udc_enable(udc);
                if (retval == 0) {
                        /* Clock is disabled, need re-init registers */
                        udc_reset(udc);
                        ep0_reset(udc);
                        udc_start(udc);
                }
        } else if (udc->driver && udc->vbus_active) {
                /* stop all the transfer in queue*/
                stop_activity(udc, udc->driver);
                udc_stop(udc);
                mv_udc_disable(udc);
        }

        spin_unlock_irqrestore(&udc->lock, flags);
        return retval;
}

static int mv_udc_start(struct usb_gadget *, struct usb_gadget_driver *);
static int mv_udc_stop(struct usb_gadget *, struct usb_gadget_driver *);
/* device controller usb_gadget_ops structure */
static const struct usb_gadget_ops mv_ops = {

        /* returns the current frame number */
        .get_frame      = mv_udc_get_frame,

        /* tries to wake up the host connected to this gadget */
        .wakeup         = mv_udc_wakeup,

        /* notify controller that VBUS is powered or not */
        .vbus_session   = mv_udc_vbus_session,

        /* D+ pullup, software-controlled connect/disconnect to USB host */
        .pullup         = mv_udc_pullup,
        .udc_start      = mv_udc_start,
        .udc_stop       = mv_udc_stop,
};

static int eps_init(struct mv_udc *udc)
{
        struct mv_ep    *ep;
        char name[14];
        int i;

        /* initialize ep0 */
        ep = &udc->eps[0];
        ep->udc = udc;
        strncpy(ep->name, "ep0", sizeof(ep->name));
        ep->ep.name = ep->name;
        ep->ep.ops = &mv_ep_ops;
        ep->wedge = 0;
        ep->stopped = 0;
        ep->ep.maxpacket = EP0_MAX_PKT_SIZE;
        ep->ep_num = 0;
        ep->ep.desc = &mv_ep0_desc;
        INIT_LIST_HEAD(&ep->queue);

        ep->ep_type = USB_ENDPOINT_XFER_CONTROL;

        /* initialize other endpoints */
        for (i = 2; i < udc->max_eps * 2; i++) {
                ep = &udc->eps[i];
                if (i % 2) {
                        snprintf(name, sizeof(name), "ep%din", i / 2);
                        ep->direction = EP_DIR_IN;
                } else {
                        snprintf(name, sizeof(name), "ep%dout", i / 2);
                        ep->direction = EP_DIR_OUT;
                }
                ep->udc = udc;
                strncpy(ep->name, name, sizeof(ep->name));
                ep->ep.name = ep->name;

                ep->ep.ops = &mv_ep_ops;
                ep->stopped = 0;
                ep->ep.maxpacket = (unsigned short) ~0;
                ep->ep_num = i / 2;

                INIT_LIST_HEAD(&ep->queue);
                list_add_tail(&ep->ep.ep_list, &udc->gadget.ep_list);

                ep->dqh = &udc->ep_dqh[i];
        }

        return 0;
}

/* delete all endpoint requests, called with spinlock held */
static void nuke(struct mv_ep *ep, int status)
{
        /* called with spinlock held */
        ep->stopped = 1;

        /* endpoint fifo flush */
        mv_ep_fifo_flush(&ep->ep);

        while (!list_empty(&ep->queue)) {
                struct mv_req *req = NULL;
                req = list_entry(ep->queue.next, struct mv_req, queue);
                done(ep, req, status);
        }
}

/* stop all USB activities */
static void stop_activity(struct mv_udc *udc, struct usb_gadget_driver *driver)
{
        struct mv_ep    *ep;

        nuke(&udc->eps[0], -ESHUTDOWN);

        list_for_each_entry(ep, &udc->gadget.ep_list, ep.ep_list) {
                nuke(ep, -ESHUTDOWN);
        }

        /* report disconnect; the driver is already quiesced */
        if (driver) {
                spin_unlock(&udc->lock);
                driver->disconnect(&udc->gadget);
                spin_lock(&udc->lock);
        }
}

static int mv_udc_start(struct usb_gadget *gadget,
                struct usb_gadget_driver *driver)
{
        struct mv_udc *udc;
        int retval = 0;
        unsigned long flags;

        udc = container_of(gadget, struct mv_udc, gadget);

        if (udc->driver)
                return -EBUSY;

        spin_lock_irqsave(&udc->lock, flags);

        /* hook up the driver ... */
        driver->driver.bus = NULL;
        udc->driver = driver;

        udc->usb_state = USB_STATE_ATTACHED;
        udc->ep0_state = WAIT_FOR_SETUP;
        udc->ep0_dir = EP_DIR_OUT;

        spin_unlock_irqrestore(&udc->lock, flags);

        if (udc->transceiver) {
                retval = otg_set_peripheral(udc->transceiver->otg,
                                        &udc->gadget);
                if (retval) {
                        dev_err(&udc->dev->dev,
                                "unable to register peripheral to otg\n");
                        udc->driver = NULL;
                        return retval;
                }
        }

        /* pullup is always on */
        mv_udc_pullup(&udc->gadget, 1);

        /* When boot with cable attached, there will be no vbus irq occurred */
        if (udc->qwork)
                queue_work(udc->qwork, &udc->vbus_work);

        return 0;
}

static int mv_udc_stop(struct usb_gadget *gadget,
                struct usb_gadget_driver *driver)
{
        struct mv_udc *udc;
        unsigned long flags;

        udc = container_of(gadget, struct mv_udc, gadget);

        spin_lock_irqsave(&udc->lock, flags);

        mv_udc_enable(udc);
        udc_stop(udc);

        /* stop all usb activities */
        udc->gadget.speed = USB_SPEED_UNKNOWN;
        stop_activity(udc, driver);
        mv_udc_disable(udc);

        spin_unlock_irqrestore(&udc->lock, flags);

        /* unbind gadget driver */
        udc->driver = NULL;

        return 0;
}

static void mv_set_ptc(struct mv_udc *udc, u32 mode)
{
        u32 portsc;

        portsc = readl(&udc->op_regs->portsc[0]);
        portsc |= mode << 16;
        writel(portsc, &udc->op_regs->portsc[0]);
}

static void prime_status_complete(struct usb_ep *ep, struct usb_request *_req)
{
        struct mv_ep *mvep = container_of(ep, struct mv_ep, ep);
        struct mv_req *req = container_of(_req, struct mv_req, req);
        struct mv_udc *udc;
        unsigned long flags;

        udc = mvep->udc;

        dev_info(&udc->dev->dev, "switch to test mode %d\n", req->test_mode);

        spin_lock_irqsave(&udc->lock, flags);
        if (req->test_mode) {
                mv_set_ptc(udc, req->test_mode);
                req->test_mode = 0;
        }
        spin_unlock_irqrestore(&udc->lock, flags);
}

static int
udc_prime_status(struct mv_udc *udc, u8 direction, u16 status, bool empty)
{
        int retval = 0;
        struct mv_req *req;
        struct mv_ep *ep;

        ep = &udc->eps[0];
        udc->ep0_dir = direction;
        udc->ep0_state = WAIT_FOR_OUT_STATUS;

        req = udc->status_req;

        /* fill in the reqest structure */
        if (empty == false) {
                *((u16 *) req->req.buf) = cpu_to_le16(status);
                req->req.length = 2;
        } else
                req->req.length = 0;

        req->ep = ep;
        req->req.status = -EINPROGRESS;
        req->req.actual = 0;
        if (udc->test_mode) {
                req->req.complete = prime_status_complete;
                req->test_mode = udc->test_mode;
                udc->test_mode = 0;
        } else
                req->req.complete = NULL;
        req->dtd_count = 0;

        if (req->req.dma == DMA_ADDR_INVALID) {
                req->req.dma = dma_map_single(ep->udc->gadget.dev.parent,
                                req->req.buf, req->req.length,
                                ep_dir(ep) ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
                req->mapped = 1;
        }

        /* prime the data phase */
        if (!req_to_dtd(req)) {
                retval = queue_dtd(ep, req);
                if (retval) {
                        dev_err(&udc->dev->dev,
                                "Failed to queue dtd when prime status\n");
                        goto out;
                }
        } else{ /* no mem */
                retval = -ENOMEM;
                dev_err(&udc->dev->dev,
                        "Failed to dma_pool_alloc when prime status\n");
                goto out;
        }

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

        return 0;
out:
        usb_gadget_unmap_request(&udc->gadget, &req->req, ep_dir(ep));

        return retval;
}

static void mv_udc_testmode(struct mv_udc *udc, u16 index)
{
        if (index <= TEST_FORCE_EN) {
                udc->test_mode = index;
                if (udc_prime_status(udc, EP_DIR_IN, 0, true))
                        ep0_stall(udc);
        } else
                dev_err(&udc->dev->dev,
                        "This test mode(%d) is not supported\n", index);
}

static void ch9setaddress(struct mv_udc *udc, struct usb_ctrlrequest *setup)
{
        udc->dev_addr = (u8)setup->wValue;

        /* update usb state */
        udc->usb_state = USB_STATE_ADDRESS;

        if (udc_prime_status(udc, EP_DIR_IN, 0, true))
                ep0_stall(udc);
}

static void ch9getstatus(struct mv_udc *udc, u8 ep_num,
        struct usb_ctrlrequest *setup)
{
        u16 status = 0;
        int retval;

        if ((setup->bRequestType & (USB_DIR_IN | USB_TYPE_MASK))
                != (USB_DIR_IN | USB_TYPE_STANDARD))
                return;

        if ((setup->bRequestType & USB_RECIP_MASK) == USB_RECIP_DEVICE) {
                status = 1 << USB_DEVICE_SELF_POWERED;
                status |= udc->remote_wakeup << USB_DEVICE_REMOTE_WAKEUP;
        } else if ((setup->bRequestType & USB_RECIP_MASK)
                        == USB_RECIP_INTERFACE) {
                /* get interface status */
                status = 0;
        } else if ((setup->bRequestType & USB_RECIP_MASK)
                        == USB_RECIP_ENDPOINT) {
                u8 ep_num, direction;

                ep_num = setup->wIndex & USB_ENDPOINT_NUMBER_MASK;
                direction = (setup->wIndex & USB_ENDPOINT_DIR_MASK)
                                ? EP_DIR_IN : EP_DIR_OUT;
                status = ep_is_stall(udc, ep_num, direction)
                                << USB_ENDPOINT_HALT;
        }

        retval = udc_prime_status(udc, EP_DIR_IN, status, false);
        if (retval)
                ep0_stall(udc);
        else
                udc->ep0_state = DATA_STATE_XMIT;
}

static void ch9clearfeature(struct mv_udc *udc, struct usb_ctrlrequest *setup)
{
        u8 ep_num;
        u8 direction;
        struct mv_ep *ep;

        if ((setup->bRequestType & (USB_TYPE_MASK | USB_RECIP_MASK))
                == ((USB_TYPE_STANDARD | USB_RECIP_DEVICE))) {
                switch (setup->wValue) {
                case USB_DEVICE_REMOTE_WAKEUP:
                        udc->remote_wakeup = 0;
                        break;
                default:
                        goto out;
                }
        } else if ((setup->bRequestType & (USB_TYPE_MASK | USB_RECIP_MASK))
                == ((USB_TYPE_STANDARD | USB_RECIP_ENDPOINT))) {
                switch (setup->wValue) {
                case USB_ENDPOINT_HALT:
                        ep_num = setup->wIndex & USB_ENDPOINT_NUMBER_MASK;
                        direction = (setup->wIndex & USB_ENDPOINT_DIR_MASK)
                                ? EP_DIR_IN : EP_DIR_OUT;
                        if (setup->wValue != 0 || setup->wLength != 0
                                || ep_num > udc->max_eps)
                                goto out;
                        ep = &udc->eps[ep_num * 2 + direction];
                        if (ep->wedge == 1)
                                break;
                        spin_unlock(&udc->lock);
                        ep_set_stall(udc, ep_num, direction, 0);
                        spin_lock(&udc->lock);
                        break;
                default:
                        goto out;
                }
        } else
                goto out;

        if (udc_prime_status(udc, EP_DIR_IN, 0, true))
                ep0_stall(udc);
out:
        return;
}

static void ch9setfeature(struct mv_udc *udc, struct usb_ctrlrequest *setup)
{
        u8 ep_num;
        u8 direction;

        if ((setup->bRequestType & (USB_TYPE_MASK | USB_RECIP_MASK))
                == ((USB_TYPE_STANDARD | USB_RECIP_DEVICE))) {
                switch (setup->wValue) {
                case USB_DEVICE_REMOTE_WAKEUP:
                        udc->remote_wakeup = 1;
                        break;
                case USB_DEVICE_TEST_MODE:
                        if (setup->wIndex & 0xFF
                                ||  udc->gadget.speed != USB_SPEED_HIGH)
                                ep0_stall(udc);

                        if (udc->usb_state != USB_STATE_CONFIGURED
                                && udc->usb_state != USB_STATE_ADDRESS
                                && udc->usb_state != USB_STATE_DEFAULT)
                                ep0_stall(udc);

                        mv_udc_testmode(udc, (setup->wIndex >> 8));
                        goto out;
                default:
                        goto out;
                }
        } else if ((setup->bRequestType & (USB_TYPE_MASK | USB_RECIP_MASK))
                == ((USB_TYPE_STANDARD | USB_RECIP_ENDPOINT))) {
                switch (setup->wValue) {
                case USB_ENDPOINT_HALT:
                        ep_num = setup->wIndex & USB_ENDPOINT_NUMBER_MASK;
                        direction = (setup->wIndex & USB_ENDPOINT_DIR_MASK)
                                ? EP_DIR_IN : EP_DIR_OUT;
                        if (setup->wValue != 0 || setup->wLength != 0
                                || ep_num > udc->max_eps)
                                goto out;
                        spin_unlock(&udc->lock);
                        ep_set_stall(udc, ep_num, direction, 1);
                        spin_lock(&udc->lock);
                        break;
                default:
                        goto out;
                }
        } else
                goto out;

        if (udc_prime_status(udc, EP_DIR_IN, 0, true))
                ep0_stall(udc);
out:
        return;
}

static void handle_setup_packet(struct mv_udc *udc, u8 ep_num,
        struct usb_ctrlrequest *setup)
        __releases(&ep->udc->lock)
        __acquires(&ep->udc->lock)
{
        bool delegate = false;

        nuke(&udc->eps[ep_num * 2 + EP_DIR_OUT], -ESHUTDOWN);

        dev_dbg(&udc->dev->dev, "SETUP %02x.%02x v%04x i%04x l%04x\n",
                        setup->bRequestType, setup->bRequest,
                        setup->wValue, setup->wIndex, setup->wLength);
        /* We process some stardard setup requests here */
        if ((setup->bRequestType & USB_TYPE_MASK) == USB_TYPE_STANDARD) {
                switch (setup->bRequest) {
                case USB_REQ_GET_STATUS:
                        ch9getstatus(udc, ep_num, setup);
                        break;

                case USB_REQ_SET_ADDRESS:
                        ch9setaddress(udc, setup);
                        break;

                case USB_REQ_CLEAR_FEATURE:
                        ch9clearfeature(udc, setup);
                        break;

                case USB_REQ_SET_FEATURE:
                        ch9setfeature(udc, setup);
                        break;

                default:
                        delegate = true;
                }
        } else
                delegate = true;

        /* delegate USB standard requests to the gadget driver */
        if (delegate == true) {
                /* USB requests handled by gadget */
                if (setup->wLength) {
                        /* DATA phase from gadget, STATUS phase from udc */
                        udc->ep0_dir = (setup->bRequestType & USB_DIR_IN)
                                        ?  EP_DIR_IN : EP_DIR_OUT;
                        spin_unlock(&udc->lock);
                        if (udc->driver->setup(&udc->gadget,
                                &udc->local_setup_buff) < 0)
                                ep0_stall(udc);
                        spin_lock(&udc->lock);
                        udc->ep0_state = (setup->bRequestType & USB_DIR_IN)
                                        ?  DATA_STATE_XMIT : DATA_STATE_RECV;
                } else {
                        /* no DATA phase, IN STATUS phase from gadget */
                        udc->ep0_dir = EP_DIR_IN;
                        spin_unlock(&udc->lock);
                        if (udc->driver->setup(&udc->gadget,
                                &udc->local_setup_buff) < 0)
                                ep0_stall(udc);
                        spin_lock(&udc->lock);
                        udc->ep0_state = WAIT_FOR_OUT_STATUS;
                }
        }
}

/* complete DATA or STATUS phase of ep0 prime status phase if needed */
static void ep0_req_complete(struct mv_udc *udc,
        struct mv_ep *ep0, struct mv_req *req)
{
        u32 new_addr;

        if (udc->usb_state == USB_STATE_ADDRESS) {
                /* set the new address */
                new_addr = (u32)udc->dev_addr;
                writel(new_addr << USB_DEVICE_ADDRESS_BIT_SHIFT,
                        &udc->op_regs->deviceaddr);
        }

        done(ep0, req, 0);

        switch (udc->ep0_state) {
        case DATA_STATE_XMIT:
                /* receive status phase */
                if (udc_prime_status(udc, EP_DIR_OUT, 0, true))
                        ep0_stall(udc);
                break;
        case DATA_STATE_RECV:
                /* send status phase */
                if (udc_prime_status(udc, EP_DIR_IN, 0 , true))
                        ep0_stall(udc);
                break;
        case WAIT_FOR_OUT_STATUS:
                udc->ep0_state = WAIT_FOR_SETUP;
                break;
        case WAIT_FOR_SETUP:
                dev_err(&udc->dev->dev, "unexpect ep0 packets\n");
                break;
        default:
                ep0_stall(udc);
                break;
        }
}

static void get_setup_data(struct mv_udc *udc, u8 ep_num, u8 *buffer_ptr)
{
        u32 temp;
        struct mv_dqh *dqh;

        dqh = &udc->ep_dqh[ep_num * 2 + EP_DIR_OUT];

        /* Clear bit in ENDPTSETUPSTAT */
        writel((1 << ep_num), &udc->op_regs->epsetupstat);

        /* while a hazard exists when setup package arrives */
        do {
                /* Set Setup Tripwire */
                temp = readl(&udc->op_regs->usbcmd);
                writel(temp | USBCMD_SETUP_TRIPWIRE_SET, &udc->op_regs->usbcmd);

                /* Copy the setup packet to local buffer */
                memcpy(buffer_ptr, (u8 *) dqh->setup_buffer, 8);
        } while (!(readl(&udc->op_regs->usbcmd) & USBCMD_SETUP_TRIPWIRE_SET));

        /* Clear Setup Tripwire */
        temp = readl(&udc->op_regs->usbcmd);
        writel(temp & ~USBCMD_SETUP_TRIPWIRE_SET, &udc->op_regs->usbcmd);
}

static void irq_process_tr_complete(struct mv_udc *udc)
{
        u32 tmp, bit_pos;
        int i, ep_num = 0, direction = 0;
        struct mv_ep    *curr_ep;
        struct mv_req *curr_req, *temp_req;
        int status;

        /*
         * We use separate loops for ENDPTSETUPSTAT and ENDPTCOMPLETE
         * because the setup packets are to be read ASAP
         */

        /* Process all Setup packet received interrupts */
        tmp = readl(&udc->op_regs->epsetupstat);

        if (tmp) {
                for (i = 0; i < udc->max_eps; i++) {
                        if (tmp & (1 << i)) {
                                get_setup_data(udc, i,
                                        (u8 *)(&udc->local_setup_buff));
                                handle_setup_packet(udc, i,
                                        &udc->local_setup_buff);
                        }
                }
        }

        /* Don't clear the endpoint setup status register here.
         * It is cleared as a setup packet is read out of the buffer
         */

        /* Process non-setup transaction complete interrupts */
        tmp = readl(&udc->op_regs->epcomplete);

        if (!tmp)
                return;

        writel(tmp, &udc->op_regs->epcomplete);

        for (i = 0; i < udc->max_eps * 2; i++) {
                ep_num = i >> 1;
                direction = i % 2;

                bit_pos = 1 << (ep_num + 16 * direction);

                if (!(bit_pos & tmp))
                        continue;

                if (i == 1)
                        curr_ep = &udc->eps[0];
                else
                        curr_ep = &udc->eps[i];
                /* process the req queue until an uncomplete request */
                list_for_each_entry_safe(curr_req, temp_req,
                        &curr_ep->queue, queue) {
                        status = process_ep_req(udc, i, curr_req);
                        if (status)
                                break;

                        /* write back status to req */
                        curr_req->req.status = status;

                        /* ep0 request completion */
                        if (ep_num == 0) {
                                ep0_req_complete(udc, curr_ep, curr_req);
                                break;
                        } else {
                                done(curr_ep, curr_req, status);
                        }
                }
        }
}

static void irq_process_reset(struct mv_udc *udc)
{
        u32 tmp;
        unsigned int loops;

        udc->ep0_dir = EP_DIR_OUT;
        udc->ep0_state = WAIT_FOR_SETUP;
        udc->remote_wakeup = 0;         /* default to 0 on reset */

        /* The address bits are past bit 25-31. Set the address */
        tmp = readl(&udc->op_regs->deviceaddr);
        tmp &= ~(USB_DEVICE_ADDRESS_MASK);
        writel(tmp, &udc->op_regs->deviceaddr);

        /* Clear all the setup token semaphores */
        tmp = readl(&udc->op_regs->epsetupstat);
        writel(tmp, &udc->op_regs->epsetupstat);

        /* Clear all the endpoint complete status bits */
        tmp = readl(&udc->op_regs->epcomplete);
        writel(tmp, &udc->op_regs->epcomplete);

        /* wait until all endptprime bits cleared */
        loops = LOOPS(PRIME_TIMEOUT);
        while (readl(&udc->op_regs->epprime) & 0xFFFFFFFF) {
                if (loops == 0) {
                        dev_err(&udc->dev->dev,
                                "Timeout for ENDPTPRIME = 0x%x\n",
                                readl(&udc->op_regs->epprime));
                        break;
                }
                loops--;
                udelay(LOOPS_USEC);
        }

        /* Write 1s to the Flush register */
        writel((u32)~0, &udc->op_regs->epflush);

        if (readl(&udc->op_regs->portsc[0]) & PORTSCX_PORT_RESET) {
                dev_info(&udc->dev->dev, "usb bus reset\n");
                udc->usb_state = USB_STATE_DEFAULT;
                /* reset all the queues, stop all USB activities */
                stop_activity(udc, udc->driver);
        } else {
                dev_info(&udc->dev->dev, "USB reset portsc 0x%x\n",
                        readl(&udc->op_regs->portsc));

                /*
                 * re-initialize
                 * controller reset
                 */
                udc_reset(udc);

                /* reset all the queues, stop all USB activities */
                stop_activity(udc, udc->driver);

                /* reset ep0 dQH and endptctrl */
                ep0_reset(udc);

                /* enable interrupt and set controller to run state */
                udc_start(udc);

                udc->usb_state = USB_STATE_ATTACHED;
        }
}

static void handle_bus_resume(struct mv_udc *udc)
{
        udc->usb_state = udc->resume_state;
        udc->resume_state = 0;

        /* report resume to the driver */
        if (udc->driver) {
                if (udc->driver->resume) {
                        spin_unlock(&udc->lock);
                        udc->driver->resume(&udc->gadget);
                        spin_lock(&udc->lock);
                }
        }
}

static void irq_process_suspend(struct mv_udc *udc)
{
        udc->resume_state = udc->usb_state;
        udc->usb_state = USB_STATE_SUSPENDED;

        if (udc->driver->suspend) {
                spin_unlock(&udc->lock);
                udc->driver->suspend(&udc->gadget);
                spin_lock(&udc->lock);
        }
}

static void irq_process_port_change(struct mv_udc *udc)
{
        u32 portsc;

        portsc = readl(&udc->op_regs->portsc[0]);
        if (!(portsc & PORTSCX_PORT_RESET)) {
                /* Get the speed */
                u32 speed = portsc & PORTSCX_PORT_SPEED_MASK;
                switch (speed) {
                case PORTSCX_PORT_SPEED_HIGH:
                        udc->gadget.speed = USB_SPEED_HIGH;
                        break;
                case PORTSCX_PORT_SPEED_FULL:
                        udc->gadget.speed = USB_SPEED_FULL;
                        break;
                case PORTSCX_PORT_SPEED_LOW:
                        udc->gadget.speed = USB_SPEED_LOW;
                        break;
                default:
                        udc->gadget.speed = USB_SPEED_UNKNOWN;
                        break;
                }
        }

        if (portsc & PORTSCX_PORT_SUSPEND) {
                udc->resume_state = udc->usb_state;
                udc->usb_state = USB_STATE_SUSPENDED;
                if (udc->driver->suspend) {
                        spin_unlock(&udc->lock);
                        udc->driver->suspend(&udc->gadget);
                        spin_lock(&udc->lock);
                }
        }

        if (!(portsc & PORTSCX_PORT_SUSPEND)
                && udc->usb_state == USB_STATE_SUSPENDED) {
                handle_bus_resume(udc);
        }

        if (!udc->resume_state)
                udc->usb_state = USB_STATE_DEFAULT;
}

static void irq_process_error(struct mv_udc *udc)
{
        /* Increment the error count */
        udc->errors++;
}

static irqreturn_t mv_udc_irq(int irq, void *dev)
{
        struct mv_udc *udc = (struct mv_udc *)dev;
        u32 status, intr;

        /* Disable ISR when stopped bit is set */
        if (udc->stopped)
                return IRQ_NONE;

        spin_lock(&udc->lock);

        status = readl(&udc->op_regs->usbsts);
        intr = readl(&udc->op_regs->usbintr);
        status &= intr;

        if (status == 0) {
                spin_unlock(&udc->lock);
                return IRQ_NONE;
        }

        /* Clear all the interrupts occurred */
        writel(status, &udc->op_regs->usbsts);

        if (status & USBSTS_ERR)
                irq_process_error(udc);

        if (status & USBSTS_RESET)
                irq_process_reset(udc);

        if (status & USBSTS_PORT_CHANGE)
                irq_process_port_change(udc);

        if (status & USBSTS_INT)
                irq_process_tr_complete(udc);

        if (status & USBSTS_SUSPEND)
                irq_process_suspend(udc);

        spin_unlock(&udc->lock);

        return IRQ_HANDLED;
}

static irqreturn_t mv_udc_vbus_irq(int irq, void *dev)
{
        struct mv_udc *udc = (struct mv_udc *)dev;

        /* polling VBUS and init phy may cause too much time*/
        if (udc->qwork)
                queue_work(udc->qwork, &udc->vbus_work);

        return IRQ_HANDLED;
}

static void mv_udc_vbus_work(struct work_struct *work)
{
        struct mv_udc *udc;
        unsigned int vbus;

        udc = container_of(work, struct mv_udc, vbus_work);
        if (!udc->pdata->vbus)
                return;

        vbus = udc->pdata->vbus->poll();
        dev_info(&udc->dev->dev, "vbus is %d\n", vbus);

        if (vbus == VBUS_HIGH)
                mv_udc_vbus_session(&udc->gadget, 1);
        else if (vbus == VBUS_LOW)
                mv_udc_vbus_session(&udc->gadget, 0);
}

/* release device structure */
static void gadget_release(struct device *_dev)
{
        struct mv_udc *udc;

        udc = dev_get_drvdata(_dev);

        complete(udc->done);
}

static int mv_udc_remove(struct platform_device *pdev)
{
        struct mv_udc *udc;

        udc = platform_get_drvdata(pdev);

        usb_del_gadget_udc(&udc->gadget);

        if (udc->qwork) {
                flush_workqueue(udc->qwork);
                destroy_workqueue(udc->qwork);
        }

        /* free memory allocated in probe */
        if (udc->dtd_pool)
                dma_pool_destroy(udc->dtd_pool);

        if (udc->ep_dqh)
                dma_free_coherent(&pdev->dev, udc->ep_dqh_size,
                        udc->ep_dqh, udc->ep_dqh_dma);

        mv_udc_disable(udc);

        /* free dev, wait for the release() finished */
        wait_for_completion(udc->done);

        return 0;
}

static int mv_udc_probe(struct platform_device *pdev)
{
        struct mv_usb_platform_data *pdata = pdev->dev.platform_data;
        struct mv_udc *udc;
        int retval = 0;
        struct resource *r;
        size_t size;

        if (pdata == NULL) {
                dev_err(&pdev->dev, "missing platform_data\n");
                return -ENODEV;
        }

        udc = devm_kzalloc(&pdev->dev, sizeof(*udc), GFP_KERNEL);
        if (udc == NULL) {
                dev_err(&pdev->dev, "failed to allocate memory for udc\n");
                return -ENOMEM;
        }

        udc->done = &release_done;
        udc->pdata = pdev->dev.platform_data;
        spin_lock_init(&udc->lock);

        udc->dev = pdev;

        if (pdata->mode == MV_USB_MODE_OTG) {
                udc->transceiver = devm_usb_get_phy(&pdev->dev,
                                        USB_PHY_TYPE_USB2);
                if (IS_ERR(udc->transceiver)) {
                        retval = PTR_ERR(udc->transceiver);

                        if (retval == -ENXIO)
                                return retval;

                        udc->transceiver = NULL;
                        return -EPROBE_DEFER;
                }
        }

        /* udc only have one sysclk. */
        udc->clk = devm_clk_get(&pdev->dev, NULL);
        if (IS_ERR(udc->clk))
                return PTR_ERR(udc->clk);

        r = platform_get_resource_byname(udc->dev, IORESOURCE_MEM, "capregs");
        if (r == NULL) {
                dev_err(&pdev->dev, "no I/O memory resource defined\n");
                return -ENODEV;
        }

        udc->cap_regs = (struct mv_cap_regs __iomem *)
                devm_ioremap(&pdev->dev, r->start, resource_size(r));
        if (udc->cap_regs == NULL) {
                dev_err(&pdev->dev, "failed to map I/O memory\n");
                return -EBUSY;
        }

        r = platform_get_resource_byname(udc->dev, IORESOURCE_MEM, "phyregs");
        if (r == NULL) {
                dev_err(&pdev->dev, "no phy I/O memory resource defined\n");
                return -ENODEV;
        }

        udc->phy_regs = ioremap(r->start, resource_size(r));
        if (udc->phy_regs == NULL) {
                dev_err(&pdev->dev, "failed to map phy I/O memory\n");
                return -EBUSY;
        }

        /* we will acces controller register, so enable the clk */
        retval = mv_udc_enable_internal(udc);
        if (retval)
                return retval;

        udc->op_regs =
                (struct mv_op_regs __iomem *)((unsigned long)udc->cap_regs
                + (readl(&udc->cap_regs->caplength_hciversion)
                        & CAPLENGTH_MASK));
        udc->max_eps = readl(&udc->cap_regs->dccparams) & DCCPARAMS_DEN_MASK;

        /*
         * some platform will use usb to download image, it may not disconnect
         * usb gadget before loading kernel. So first stop udc here.
         */
        udc_stop(udc);
        writel(0xFFFFFFFF, &udc->op_regs->usbsts);

        size = udc->max_eps * sizeof(struct mv_dqh) *2;
        size = (size + DQH_ALIGNMENT - 1) & ~(DQH_ALIGNMENT - 1);
        udc->ep_dqh = dma_alloc_coherent(&pdev->dev, size,
                                        &udc->ep_dqh_dma, GFP_KERNEL);

        if (udc->ep_dqh == NULL) {
                dev_err(&pdev->dev, "allocate dQH memory failed\n");
                retval = -ENOMEM;
                goto err_disable_clock;
        }
        udc->ep_dqh_size = size;

        /* create dTD dma_pool resource */
        udc->dtd_pool = dma_pool_create("mv_dtd",
                        &pdev->dev,
                        sizeof(struct mv_dtd),
                        DTD_ALIGNMENT,
                        DMA_BOUNDARY);

        if (!udc->dtd_pool) {
                retval = -ENOMEM;
                goto err_free_dma;
        }

        size = udc->max_eps * sizeof(struct mv_ep) *2;
        udc->eps = devm_kzalloc(&pdev->dev, size, GFP_KERNEL);
        if (udc->eps == NULL) {
                dev_err(&pdev->dev, "allocate ep memory failed\n");
                retval = -ENOMEM;
                goto err_destroy_dma;
        }

        /* initialize ep0 status request structure */
        udc->status_req = devm_kzalloc(&pdev->dev, sizeof(struct mv_req),
                                        GFP_KERNEL);
        if (!udc->status_req) {
                dev_err(&pdev->dev, "allocate status_req memory failed\n");
                retval = -ENOMEM;
                goto err_destroy_dma;
        }
        INIT_LIST_HEAD(&udc->status_req->queue);

        /* allocate a small amount of memory to get valid address */
        udc->status_req->req.buf = kzalloc(8, GFP_KERNEL);
        udc->status_req->req.dma = DMA_ADDR_INVALID;

        udc->resume_state = USB_STATE_NOTATTACHED;
        udc->usb_state = USB_STATE_POWERED;
        udc->ep0_dir = EP_DIR_OUT;
        udc->remote_wakeup = 0;

        r = platform_get_resource(udc->dev, IORESOURCE_IRQ, 0);
        if (r == NULL) {
                dev_err(&pdev->dev, "no IRQ resource defined\n");
                retval = -ENODEV;
                goto err_destroy_dma;
        }
        udc->irq = r->start;
        if (devm_request_irq(&pdev->dev, udc->irq, mv_udc_irq,
                IRQF_SHARED, driver_name, udc)) {
                dev_err(&pdev->dev, "Request irq %d for UDC failed\n",
                        udc->irq);
                retval = -ENODEV;
                goto err_destroy_dma;
        }

        /* initialize gadget structure */
        udc->gadget.ops = &mv_ops;      /* usb_gadget_ops */
        udc->gadget.ep0 = &udc->eps[0].ep;      /* gadget ep0 */
        INIT_LIST_HEAD(&udc->gadget.ep_list);   /* ep_list */
        udc->gadget.speed = USB_SPEED_UNKNOWN;  /* speed */
        udc->gadget.max_speed = USB_SPEED_HIGH; /* support dual speed */

        /* the "gadget" abstracts/virtualizes the controller */
        udc->gadget.name = driver_name;         /* gadget name */

        eps_init(udc);

        /* VBUS detect: we can disable/enable clock on demand.*/
        if (udc->transceiver)
                udc->clock_gating = 1;
        else if (pdata->vbus) {
                udc->clock_gating = 1;
                retval = devm_request_threaded_irq(&pdev->dev,
                                pdata->vbus->irq, NULL,
                                mv_udc_vbus_irq, IRQF_ONESHOT, "vbus", udc);
                if (retval) {
                        dev_info(&pdev->dev,
                                "Can not request irq for VBUS, "
                                "disable clock gating\n");
                        udc->clock_gating = 0;
                }

                udc->qwork = create_singlethread_workqueue("mv_udc_queue");
                if (!udc->qwork) {
                        dev_err(&pdev->dev, "cannot create workqueue\n");
                        retval = -ENOMEM;
                        goto err_destroy_dma;
                }

                INIT_WORK(&udc->vbus_work, mv_udc_vbus_work);
        }

        /*
         * When clock gating is supported, we can disable clk and phy.
         * If not, it means that VBUS detection is not supported, we
         * have to enable vbus active all the time to let controller work.
         */
        if (udc->clock_gating)
                mv_udc_disable_internal(udc);
        else
                udc->vbus_active = 1;

        retval = usb_add_gadget_udc_release(&pdev->dev, &udc->gadget,
                        gadget_release);
        if (retval)
                goto err_create_workqueue;

        platform_set_drvdata(pdev, udc);
        dev_info(&pdev->dev, "successful probe UDC device %s clock gating.\n",
                udc->clock_gating ? "with" : "without");

        return 0;

err_create_workqueue:
        destroy_workqueue(udc->qwork);
err_destroy_dma:
        dma_pool_destroy(udc->dtd_pool);
err_free_dma:
        dma_free_coherent(&pdev->dev, udc->ep_dqh_size,
                        udc->ep_dqh, udc->ep_dqh_dma);
err_disable_clock:
        mv_udc_disable_internal(udc);

        return retval;
}

#ifdef CONFIG_PM
static int mv_udc_suspend(struct device *dev)
{
        struct mv_udc *udc;

        udc = dev_get_drvdata(dev);

        /* if OTG is enabled, the following will be done in OTG driver*/
        if (udc->transceiver)
                return 0;

        if (udc->pdata->vbus && udc->pdata->vbus->poll)
                if (udc->pdata->vbus->poll() == VBUS_HIGH) {
                        dev_info(&udc->dev->dev, "USB cable is connected!\n");
                        return -EAGAIN;
                }

        /*
         * only cable is unplugged, udc can suspend.
         * So do not care about clock_gating == 1.
         */
        if (!udc->clock_gating) {
                udc_stop(udc);

                spin_lock_irq(&udc->lock);
                /* stop all usb activities */
                stop_activity(udc, udc->driver);
                spin_unlock_irq(&udc->lock);

                mv_udc_disable_internal(udc);
        }

        return 0;
}

static int mv_udc_resume(struct device *dev)
{
        struct mv_udc *udc;
        int retval;

        udc = dev_get_drvdata(dev);

        /* if OTG is enabled, the following will be done in OTG driver*/
        if (udc->transceiver)
                return 0;

        if (!udc->clock_gating) {
                retval = mv_udc_enable_internal(udc);
                if (retval)
                        return retval;

                if (udc->driver && udc->softconnect) {
                        udc_reset(udc);
                        ep0_reset(udc);
                        udc_start(udc);
                }
        }

        return 0;
}

static const struct dev_pm_ops mv_udc_pm_ops = {
        .suspend        = mv_udc_suspend,
        .resume         = mv_udc_resume,
};
#endif

static void mv_udc_shutdown(struct platform_device *pdev)
{
        struct mv_udc *udc;
        u32 mode;

        udc = platform_get_drvdata(pdev);
        /* reset controller mode to IDLE */
        mv_udc_enable(udc);
        mode = readl(&udc->op_regs->usbmode);
        mode &= ~3;
        writel(mode, &udc->op_regs->usbmode);
        mv_udc_disable(udc);
}

static struct platform_driver udc_driver = {
        .probe          = mv_udc_probe,
        .remove         = mv_udc_remove,
        .shutdown       = mv_udc_shutdown,
        .driver         = {
                .owner  = THIS_MODULE,
                .name   = "mv-udc",
#ifdef CONFIG_PM
                .pm     = &mv_udc_pm_ops,
#endif
        },
};

module_platform_driver(udc_driver);
MODULE_ALIAS("platform:mv-udc");
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_AUTHOR("Chao Xie <chao.xie@marvell.com>");
MODULE_VERSION(DRIVER_VERSION);
MODULE_LICENSE("GPL");