/*
 * Copyright (C) 2011 Marvell International Ltd. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 */

#include <linux/module.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/timer.h>
#include <linux/list.h>
#include <linux/notifier.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/pm.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/platform_device.h>
#include <linux/platform_data/mv_usb.h>
#include <linux/clk.h>

#include "mv_u3d.h"

#define DRIVER_DESC             "Marvell PXA USB3.0 Device Controller driver"

static const char driver_name[] = "mv_u3d";
static const char driver_desc[] = DRIVER_DESC;

static void mv_u3d_nuke(struct mv_u3d_ep *ep, int status);
static void mv_u3d_stop_activity(struct mv_u3d *u3d,
                        struct usb_gadget_driver *driver);

/* for endpoint 0 operations */
static const struct usb_endpoint_descriptor mv_u3d_ep0_desc = {
        .bLength =              USB_DT_ENDPOINT_SIZE,
        .bDescriptorType =      USB_DT_ENDPOINT,
        .bEndpointAddress =     0,
        .bmAttributes =         USB_ENDPOINT_XFER_CONTROL,
        .wMaxPacketSize =       MV_U3D_EP0_MAX_PKT_SIZE,
};

static void mv_u3d_ep0_reset(struct mv_u3d *u3d)
{
        struct mv_u3d_ep *ep;
        u32 epxcr;
        int i;

        for (i = 0; i < 2; i++) {
                ep = &u3d->eps[i];
                ep->u3d = u3d;

                /* ep0 ep context, ep0 in and out share the same ep context */
                ep->ep_context = &u3d->ep_context[1];
        }

        /* reset ep state machine */
        /* reset ep0 out */
        epxcr = ioread32(&u3d->vuc_regs->epcr[0].epxoutcr0);
        epxcr |= MV_U3D_EPXCR_EP_INIT;
        iowrite32(epxcr, &u3d->vuc_regs->epcr[0].epxoutcr0);
        udelay(5);
        epxcr &= ~MV_U3D_EPXCR_EP_INIT;
        iowrite32(epxcr, &u3d->vuc_regs->epcr[0].epxoutcr0);

        epxcr = ((MV_U3D_EP0_MAX_PKT_SIZE
                << MV_U3D_EPXCR_MAX_PACKET_SIZE_SHIFT)
                | (1 << MV_U3D_EPXCR_MAX_BURST_SIZE_SHIFT)
                | (1 << MV_U3D_EPXCR_EP_ENABLE_SHIFT)
                | MV_U3D_EPXCR_EP_TYPE_CONTROL);
        iowrite32(epxcr, &u3d->vuc_regs->epcr[0].epxoutcr1);

        /* reset ep0 in */
        epxcr = ioread32(&u3d->vuc_regs->epcr[0].epxincr0);
        epxcr |= MV_U3D_EPXCR_EP_INIT;
        iowrite32(epxcr, &u3d->vuc_regs->epcr[0].epxincr0);
        udelay(5);
        epxcr &= ~MV_U3D_EPXCR_EP_INIT;
        iowrite32(epxcr, &u3d->vuc_regs->epcr[0].epxincr0);

        epxcr = ((MV_U3D_EP0_MAX_PKT_SIZE
                << MV_U3D_EPXCR_MAX_PACKET_SIZE_SHIFT)
                | (1 << MV_U3D_EPXCR_MAX_BURST_SIZE_SHIFT)
                | (1 << MV_U3D_EPXCR_EP_ENABLE_SHIFT)
                | MV_U3D_EPXCR_EP_TYPE_CONTROL);
        iowrite32(epxcr, &u3d->vuc_regs->epcr[0].epxincr1);
}

static void mv_u3d_ep0_stall(struct mv_u3d *u3d)
{
        u32 tmp;
        dev_dbg(u3d->dev, "%s\n", __func__);

        /* set TX and RX to stall */
        tmp = ioread32(&u3d->vuc_regs->epcr[0].epxoutcr0);
        tmp |= MV_U3D_EPXCR_EP_HALT;
        iowrite32(tmp, &u3d->vuc_regs->epcr[0].epxoutcr0);

        tmp = ioread32(&u3d->vuc_regs->epcr[0].epxincr0);
        tmp |= MV_U3D_EPXCR_EP_HALT;
        iowrite32(tmp, &u3d->vuc_regs->epcr[0].epxincr0);

        /* update ep0 state */
        u3d->ep0_state = MV_U3D_WAIT_FOR_SETUP;
        u3d->ep0_dir = MV_U3D_EP_DIR_OUT;
}

static int mv_u3d_process_ep_req(struct mv_u3d *u3d, int index,
        struct mv_u3d_req *curr_req)
{
        struct mv_u3d_trb       *curr_trb;
        dma_addr_t cur_deq_lo;
        struct mv_u3d_ep_context        *curr_ep_context;
        int trb_complete, actual, remaining_length = 0;
        int direction, ep_num;
        int retval = 0;
        u32 tmp, status, length;

        curr_ep_context = &u3d->ep_context[index];
        direction = index % 2;
        ep_num = index / 2;

        trb_complete = 0;
        actual = curr_req->req.length;

        while (!list_empty(&curr_req->trb_list)) {
                curr_trb = list_entry(curr_req->trb_list.next,
                                        struct mv_u3d_trb, trb_list);
                if (!curr_trb->trb_hw->ctrl.own) {
                        dev_err(u3d->dev, "%s, TRB own error!\n",
                                u3d->eps[index].name);
                        return 1;
                }

                curr_trb->trb_hw->ctrl.own = 0;
                if (direction == MV_U3D_EP_DIR_OUT) {
                        tmp = ioread32(&u3d->vuc_regs->rxst[ep_num].statuslo);
                        cur_deq_lo =
                                ioread32(&u3d->vuc_regs->rxst[ep_num].curdeqlo);
                } else {
                        tmp = ioread32(&u3d->vuc_regs->txst[ep_num].statuslo);
                        cur_deq_lo =
                                ioread32(&u3d->vuc_regs->txst[ep_num].curdeqlo);
                }

                status = tmp >> MV_U3D_XFERSTATUS_COMPLETE_SHIFT;
                length = tmp & MV_U3D_XFERSTATUS_TRB_LENGTH_MASK;

                if (status == MV_U3D_COMPLETE_SUCCESS ||
                        (status == MV_U3D_COMPLETE_SHORT_PACKET &&
                        direction == MV_U3D_EP_DIR_OUT)) {
                        remaining_length += length;
                        actual -= remaining_length;
                } else {
                        dev_err(u3d->dev,
                                "complete_tr error: ep=%d %s: error = 0x%x\n",
                                index >> 1, direction ? "SEND" : "RECV",
                                status);
                        retval = -EPROTO;
                }

                list_del_init(&curr_trb->trb_list);
        }
        if (retval)
                return retval;

        curr_req->req.actual = actual;
        return 0;
}

/*
 * mv_u3d_done() - retire a request; caller blocked irqs
 * @status : request status to be set, only works when
 * request is still in progress.
 */
static
void mv_u3d_done(struct mv_u3d_ep *ep, struct mv_u3d_req *req, int status)
        __releases(&ep->udc->lock)
        __acquires(&ep->udc->lock)
{
        struct mv_u3d *u3d = (struct mv_u3d *)ep->u3d;

        dev_dbg(u3d->dev, "mv_u3d_done: remove req->queue\n");
        /* Removed the req from 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 trb for the request */
        if (!req->chain)
                dma_pool_free(u3d->trb_pool,
                        req->trb_head->trb_hw, req->trb_head->trb_dma);
        else {
                dma_unmap_single(ep->u3d->gadget.dev.parent,
                        (dma_addr_t)req->trb_head->trb_dma,
                        req->trb_count * sizeof(struct mv_u3d_trb_hw),
                        DMA_BIDIRECTIONAL);
                kfree(req->trb_head->trb_hw);
        }
        kfree(req->trb_head);

        usb_gadget_unmap_request(&u3d->gadget, &req->req, mv_u3d_ep_dir(ep));

        if (status && (status != -ESHUTDOWN)) {
                dev_dbg(u3d->dev, "complete %s req %p stat %d len %u/%u",
                        ep->ep.name, &req->req, status,
                        req->req.actual, req->req.length);
        }

        spin_unlock(&ep->u3d->lock);

        usb_gadget_giveback_request(&ep->ep, &req->req);

        spin_lock(&ep->u3d->lock);
}

static int mv_u3d_queue_trb(struct mv_u3d_ep *ep, struct mv_u3d_req *req)
{
        u32 tmp, direction;
        struct mv_u3d *u3d;
        struct mv_u3d_ep_context *ep_context;
        int retval = 0;

        u3d = ep->u3d;
        direction = mv_u3d_ep_dir(ep);

        /* ep0 in and out share the same ep context slot 1*/
        if (ep->ep_num == 0)
                ep_context = &(u3d->ep_context[1]);
        else
                ep_context = &(u3d->ep_context[ep->ep_num * 2 + direction]);

        /* check if the pipe is empty or not */
        if (!list_empty(&ep->queue)) {
                dev_err(u3d->dev, "add trb to non-empty queue!\n");
                retval = -ENOMEM;
                WARN_ON(1);
        } else {
                ep_context->rsvd0 = cpu_to_le32(1);
                ep_context->rsvd1 = 0;

                /* Configure the trb address and set the DCS bit.
                 * Both DCS bit and own bit in trb should be set.
                 */
                ep_context->trb_addr_lo =
                        cpu_to_le32(req->trb_head->trb_dma | DCS_ENABLE);
                ep_context->trb_addr_hi = 0;

                /* Ensure that updates to the EP Context will
                 * occure before Ring Bell.
                 */
                wmb();

                /* ring bell the ep */
                if (ep->ep_num == 0)
                        tmp = 0x1;
                else
                        tmp = ep->ep_num * 2
                                + ((direction == MV_U3D_EP_DIR_OUT) ? 0 : 1);

                iowrite32(tmp, &u3d->op_regs->doorbell);
        }
        return retval;
}

static struct mv_u3d_trb *mv_u3d_build_trb_one(struct mv_u3d_req *req,
                                unsigned *length, dma_addr_t *dma)
{
        u32 temp;
        unsigned int direction;
        struct mv_u3d_trb *trb;
        struct mv_u3d_trb_hw *trb_hw;
        struct mv_u3d *u3d;

        /* how big will this transfer be? */
        *length = req->req.length - req->req.actual;
        BUG_ON(*length > (unsigned)MV_U3D_EP_MAX_LENGTH_TRANSFER);

        u3d = req->ep->u3d;

        trb = kzalloc(sizeof(*trb), GFP_ATOMIC);
        if (!trb)
                return NULL;

        /*
         * Be careful that no _GFP_HIGHMEM is set,
         * or we can not use dma_to_virt
         * cannot use GFP_KERNEL in spin lock
         */
        trb_hw = dma_pool_alloc(u3d->trb_pool, GFP_ATOMIC, dma);
        if (!trb_hw) {
                kfree(trb);
                dev_err(u3d->dev,
                        "%s, dma_pool_alloc fail\n", __func__);
                return NULL;
        }
        trb->trb_dma = *dma;
        trb->trb_hw = trb_hw;

        /* initialize buffer page pointers */
        temp = (u32)(req->req.dma + req->req.actual);

        trb_hw->buf_addr_lo = cpu_to_le32(temp);
        trb_hw->buf_addr_hi = 0;
        trb_hw->trb_len = cpu_to_le32(*length);
        trb_hw->ctrl.own = 1;

        if (req->ep->ep_num == 0)
                trb_hw->ctrl.type = TYPE_DATA;
        else
                trb_hw->ctrl.type = TYPE_NORMAL;

        req->req.actual += *length;

        direction = mv_u3d_ep_dir(req->ep);
        if (direction == MV_U3D_EP_DIR_IN)
                trb_hw->ctrl.dir = 1;
        else
                trb_hw->ctrl.dir = 0;

        /* Enable interrupt for the last trb of a request */
        if (!req->req.no_interrupt)
                trb_hw->ctrl.ioc = 1;

        trb_hw->ctrl.chain = 0;

        wmb();
        return trb;
}

static int mv_u3d_build_trb_chain(struct mv_u3d_req *req, unsigned *length,
                struct mv_u3d_trb *trb, int *is_last)
{
        u32 temp;
        unsigned int direction;
        struct mv_u3d *u3d;

        /* how big will this transfer be? */
        *length = min(req->req.length - req->req.actual,
                        (unsigned)MV_U3D_EP_MAX_LENGTH_TRANSFER);

        u3d = req->ep->u3d;

        trb->trb_dma = 0;

        /* initialize buffer page pointers */
        temp = (u32)(req->req.dma + req->req.actual);

        trb->trb_hw->buf_addr_lo = cpu_to_le32(temp);
        trb->trb_hw->buf_addr_hi = 0;
        trb->trb_hw->trb_len = cpu_to_le32(*length);
        trb->trb_hw->ctrl.own = 1;

        if (req->ep->ep_num == 0)
                trb->trb_hw->ctrl.type = TYPE_DATA;
        else
                trb->trb_hw->ctrl.type = TYPE_NORMAL;

        req->req.actual += *length;

        direction = mv_u3d_ep_dir(req->ep);
        if (direction == MV_U3D_EP_DIR_IN)
                trb->trb_hw->ctrl.dir = 1;
        else
                trb->trb_hw->ctrl.dir = 0;

        /* 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;

        /* Enable interrupt for the last trb of a request */
        if (*is_last && !req->req.no_interrupt)
                trb->trb_hw->ctrl.ioc = 1;

        if (*is_last)
                trb->trb_hw->ctrl.chain = 0;
        else {
                trb->trb_hw->ctrl.chain = 1;
                dev_dbg(u3d->dev, "chain trb\n");
        }

        wmb();

        return 0;
}

/* generate TRB linked list for a request
 * usb controller only supports continous trb chain,
 * that trb structure physical address should be continous.
 */
static int mv_u3d_req_to_trb(struct mv_u3d_req *req)
{
        unsigned count;
        int is_last;
        struct mv_u3d_trb *trb;
        struct mv_u3d_trb_hw *trb_hw;
        struct mv_u3d *u3d;
        dma_addr_t dma;
        unsigned length;
        unsigned trb_num;

        u3d = req->ep->u3d;

        INIT_LIST_HEAD(&req->trb_list);

        length = req->req.length - req->req.actual;
        /* normally the request transfer length is less than 16KB.
         * we use buil_trb_one() to optimize it.
         */
        if (length <= (unsigned)MV_U3D_EP_MAX_LENGTH_TRANSFER) {
                trb = mv_u3d_build_trb_one(req, &count, &dma);
                list_add_tail(&trb->trb_list, &req->trb_list);
                req->trb_head = trb;
                req->trb_count = 1;
                req->chain = 0;
        } else {
                trb_num = length / MV_U3D_EP_MAX_LENGTH_TRANSFER;
                if (length % MV_U3D_EP_MAX_LENGTH_TRANSFER)
                        trb_num++;

                trb = kcalloc(trb_num, sizeof(*trb), GFP_ATOMIC);
                if (!trb)
                        return -ENOMEM;

                trb_hw = kcalloc(trb_num, sizeof(*trb_hw), GFP_ATOMIC);
                if (!trb_hw) {
                        kfree(trb);
                        return -ENOMEM;
                }

                do {
                        trb->trb_hw = trb_hw;
                        if (mv_u3d_build_trb_chain(req, &count,
                                                trb, &is_last)) {
                                dev_err(u3d->dev,
                                        "%s, mv_u3d_build_trb_chain fail\n",
                                        __func__);
                                return -EIO;
                        }

                        list_add_tail(&trb->trb_list, &req->trb_list);
                        req->trb_count++;
                        trb++;
                        trb_hw++;
                } while (!is_last);

                req->trb_head = list_entry(req->trb_list.next,
                                        struct mv_u3d_trb, trb_list);
                req->trb_head->trb_dma = dma_map_single(u3d->gadget.dev.parent,
                                        req->trb_head->trb_hw,
                                        trb_num * sizeof(*trb_hw),
                                        DMA_BIDIRECTIONAL);

                req->chain = 1;
        }

        return 0;
}

static int
mv_u3d_start_queue(struct mv_u3d_ep *ep)
{
        struct mv_u3d *u3d = ep->u3d;
        struct mv_u3d_req *req;
        int ret;

        if (!list_empty(&ep->req_list) && !ep->processing)
                req = list_entry(ep->req_list.next, struct mv_u3d_req, list);
        else
                return 0;

        ep->processing = 1;

        /* set up dma mapping */
        ret = usb_gadget_map_request(&u3d->gadget, &req->req,
                                        mv_u3d_ep_dir(ep));
        if (ret)
                return ret;

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

        /* build trbs and push them to device queue */
        if (!mv_u3d_req_to_trb(req)) {
                ret = mv_u3d_queue_trb(ep, req);
                if (ret) {
                        ep->processing = 0;
                        return ret;
                }
        } else {
                ep->processing = 0;
                dev_err(u3d->dev, "%s, mv_u3d_req_to_trb fail\n", __func__);
                return -ENOMEM;
        }

        /* irq handler advances the queue */
        if (req)
                list_add_tail(&req->queue, &ep->queue);

        return 0;
}

static int mv_u3d_ep_enable(struct usb_ep *_ep,
                const struct usb_endpoint_descriptor *desc)
{
        struct mv_u3d *u3d;
        struct mv_u3d_ep *ep;
        struct mv_u3d_ep_context *ep_context;
        u16 max = 0;
        unsigned maxburst = 0;
        u32 epxcr, direction;

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

        ep = container_of(_ep, struct mv_u3d_ep, ep);
        u3d = ep->u3d;

        if (!u3d->driver || u3d->gadget.speed == USB_SPEED_UNKNOWN)
                return -ESHUTDOWN;

        direction = mv_u3d_ep_dir(ep);
        max = le16_to_cpu(desc->wMaxPacketSize);

        if (!_ep->maxburst)
                _ep->maxburst = 1;
        maxburst = _ep->maxburst;

        /* Get the endpoint context address */
        ep_context = (struct mv_u3d_ep_context *)ep->ep_context;

        /* Set the max burst size */
        switch (desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) {
        case USB_ENDPOINT_XFER_BULK:
                if (maxburst > 16) {
                        dev_dbg(u3d->dev,
                                "max burst should not be greater "
                                "than 16 on bulk ep\n");
                        maxburst = 1;
                        _ep->maxburst = maxburst;
                }
                dev_dbg(u3d->dev,
                        "maxburst: %d on bulk %s\n", maxburst, ep->name);
                break;
        case USB_ENDPOINT_XFER_CONTROL:
                /* control transfer only supports maxburst as one */
                maxburst = 1;
                _ep->maxburst = maxburst;
                break;
        case USB_ENDPOINT_XFER_INT:
                if (maxburst != 1) {
                        dev_dbg(u3d->dev,
                                "max burst should be 1 on int ep "
                                "if transfer size is not 1024\n");
                        maxburst = 1;
                        _ep->maxburst = maxburst;
                }
                break;
        case USB_ENDPOINT_XFER_ISOC:
                if (maxburst != 1) {
                        dev_dbg(u3d->dev,
                                "max burst should be 1 on isoc ep "
                                "if transfer size is not 1024\n");
                        maxburst = 1;
                        _ep->maxburst = maxburst;
                }
                break;
        default:
                goto en_done;
        }

        ep->ep.maxpacket = max;
        ep->ep.desc = desc;
        ep->enabled = 1;

        /* Enable the endpoint for Rx or Tx and set the endpoint type */
        if (direction == MV_U3D_EP_DIR_OUT) {
                epxcr = ioread32(&u3d->vuc_regs->epcr[ep->ep_num].epxoutcr0);
                epxcr |= MV_U3D_EPXCR_EP_INIT;
                iowrite32(epxcr, &u3d->vuc_regs->epcr[ep->ep_num].epxoutcr0);
                udelay(5);
                epxcr &= ~MV_U3D_EPXCR_EP_INIT;
                iowrite32(epxcr, &u3d->vuc_regs->epcr[ep->ep_num].epxoutcr0);

                epxcr = ((max << MV_U3D_EPXCR_MAX_PACKET_SIZE_SHIFT)
                      | ((maxburst - 1) << MV_U3D_EPXCR_MAX_BURST_SIZE_SHIFT)
                      | (1 << MV_U3D_EPXCR_EP_ENABLE_SHIFT)
                      | (desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK));
                iowrite32(epxcr, &u3d->vuc_regs->epcr[ep->ep_num].epxoutcr1);
        } else {
                epxcr = ioread32(&u3d->vuc_regs->epcr[ep->ep_num].epxincr0);
                epxcr |= MV_U3D_EPXCR_EP_INIT;
                iowrite32(epxcr, &u3d->vuc_regs->epcr[ep->ep_num].epxincr0);
                udelay(5);
                epxcr &= ~MV_U3D_EPXCR_EP_INIT;
                iowrite32(epxcr, &u3d->vuc_regs->epcr[ep->ep_num].epxincr0);

                epxcr = ((max << MV_U3D_EPXCR_MAX_PACKET_SIZE_SHIFT)
                      | ((maxburst - 1) << MV_U3D_EPXCR_MAX_BURST_SIZE_SHIFT)
                      | (1 << MV_U3D_EPXCR_EP_ENABLE_SHIFT)
                      | (desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK));
                iowrite32(epxcr, &u3d->vuc_regs->epcr[ep->ep_num].epxincr1);
        }

        return 0;
en_done:
        return -EINVAL;
}

static int  mv_u3d_ep_disable(struct usb_ep *_ep)
{
        struct mv_u3d *u3d;
        struct mv_u3d_ep *ep;
        struct mv_u3d_ep_context *ep_context;
        u32 epxcr, direction;
        unsigned long flags;

        if (!_ep)
                return -EINVAL;

        ep = container_of(_ep, struct mv_u3d_ep, ep);
        if (!ep->ep.desc)
                return -EINVAL;

        u3d = ep->u3d;

        /* Get the endpoint context address */
        ep_context = ep->ep_context;

        direction = mv_u3d_ep_dir(ep);

        /* nuke all pending requests (does flush) */
        spin_lock_irqsave(&u3d->lock, flags);
        mv_u3d_nuke(ep, -ESHUTDOWN);
        spin_unlock_irqrestore(&u3d->lock, flags);

        /* Disable the endpoint for Rx or Tx and reset the endpoint type */
        if (direction == MV_U3D_EP_DIR_OUT) {
                epxcr = ioread32(&u3d->vuc_regs->epcr[ep->ep_num].epxoutcr1);
                epxcr &= ~((1 << MV_U3D_EPXCR_EP_ENABLE_SHIFT)
                      | USB_ENDPOINT_XFERTYPE_MASK);
                iowrite32(epxcr, &u3d->vuc_regs->epcr[ep->ep_num].epxoutcr1);
        } else {
                epxcr = ioread32(&u3d->vuc_regs->epcr[ep->ep_num].epxincr1);
                epxcr &= ~((1 << MV_U3D_EPXCR_EP_ENABLE_SHIFT)
                      | USB_ENDPOINT_XFERTYPE_MASK);
                iowrite32(epxcr, &u3d->vuc_regs->epcr[ep->ep_num].epxincr1);
        }

        ep->enabled = 0;

        ep->ep.desc = NULL;
        return 0;
}

static struct usb_request *
mv_u3d_alloc_request(struct usb_ep *_ep, gfp_t gfp_flags)
{
        struct mv_u3d_req *req = NULL;

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

        INIT_LIST_HEAD(&req->queue);

        return &req->req;
}

static void mv_u3d_free_request(struct usb_ep *_ep, struct usb_request *_req)
{
        struct mv_u3d_req *req = container_of(_req, struct mv_u3d_req, req);

        kfree(req);
}

static void mv_u3d_ep_fifo_flush(struct usb_ep *_ep)
{
        struct mv_u3d *u3d;
        u32 direction;
        struct mv_u3d_ep *ep = container_of(_ep, struct mv_u3d_ep, ep);
        unsigned int loops;
        u32 tmp;

        /* if endpoint is not enabled, cannot flush endpoint */
        if (!ep->enabled)
                return;

        u3d = ep->u3d;
        direction = mv_u3d_ep_dir(ep);

        /* ep0 need clear bit after flushing fifo. */
        if (!ep->ep_num) {
                if (direction == MV_U3D_EP_DIR_OUT) {
                        tmp = ioread32(&u3d->vuc_regs->epcr[0].epxoutcr0);
                        tmp |= MV_U3D_EPXCR_EP_FLUSH;
                        iowrite32(tmp, &u3d->vuc_regs->epcr[0].epxoutcr0);
                        udelay(10);
                        tmp &= ~MV_U3D_EPXCR_EP_FLUSH;
                        iowrite32(tmp, &u3d->vuc_regs->epcr[0].epxoutcr0);
                } else {
                        tmp = ioread32(&u3d->vuc_regs->epcr[0].epxincr0);
                        tmp |= MV_U3D_EPXCR_EP_FLUSH;
                        iowrite32(tmp, &u3d->vuc_regs->epcr[0].epxincr0);
                        udelay(10);
                        tmp &= ~MV_U3D_EPXCR_EP_FLUSH;
                        iowrite32(tmp, &u3d->vuc_regs->epcr[0].epxincr0);
                }
                return;
        }

        if (direction == MV_U3D_EP_DIR_OUT) {
                tmp = ioread32(&u3d->vuc_regs->epcr[ep->ep_num].epxoutcr0);
                tmp |= MV_U3D_EPXCR_EP_FLUSH;
                iowrite32(tmp, &u3d->vuc_regs->epcr[ep->ep_num].epxoutcr0);

                /* Wait until flushing completed */
                loops = LOOPS(MV_U3D_FLUSH_TIMEOUT);
                while (ioread32(&u3d->vuc_regs->epcr[ep->ep_num].epxoutcr0) &
                        MV_U3D_EPXCR_EP_FLUSH) {
                        /*
                         * EP_FLUSH bit should be cleared to indicate this
                         * operation is complete
                         */
                        if (loops == 0) {
                                dev_dbg(u3d->dev,
                                    "EP FLUSH TIMEOUT for ep%d%s\n", ep->ep_num,
                                    direction ? "in" : "out");
                                return;
                        }
                        loops--;
                        udelay(LOOPS_USEC);
                }
        } else {        /* EP_DIR_IN */
                tmp = ioread32(&u3d->vuc_regs->epcr[ep->ep_num].epxincr0);
                tmp |= MV_U3D_EPXCR_EP_FLUSH;
                iowrite32(tmp, &u3d->vuc_regs->epcr[ep->ep_num].epxincr0);

                /* Wait until flushing completed */
                loops = LOOPS(MV_U3D_FLUSH_TIMEOUT);
                while (ioread32(&u3d->vuc_regs->epcr[ep->ep_num].epxincr0) &
                        MV_U3D_EPXCR_EP_FLUSH) {
                        /*
                        * EP_FLUSH bit should be cleared to indicate this
                        * operation is complete
                        */
                        if (loops == 0) {
                                dev_dbg(u3d->dev,
                                    "EP FLUSH TIMEOUT for ep%d%s\n", ep->ep_num,
                                    direction ? "in" : "out");
                                return;
                        }
                        loops--;
                        udelay(LOOPS_USEC);
                }
        }
}

/* queues (submits) an I/O request to an endpoint */
static int
mv_u3d_ep_queue(struct usb_ep *_ep, struct usb_request *_req, gfp_t gfp_flags)
{
        struct mv_u3d_ep *ep;
        struct mv_u3d_req *req;
        struct mv_u3d *u3d;
        unsigned long flags;
        int is_first_req = 0;

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

        ep = container_of(_ep, struct mv_u3d_ep, ep);
        u3d = ep->u3d;

        req = container_of(_req, struct mv_u3d_req, req);

        if (!ep->ep_num
                && u3d->ep0_state == MV_U3D_STATUS_STAGE
                && !_req->length) {
                dev_dbg(u3d->dev, "ep0 status stage\n");
                u3d->ep0_state = MV_U3D_WAIT_FOR_SETUP;
                return 0;
        }

        dev_dbg(u3d->dev, "%s: %s, req: 0x%p\n",
                        __func__, _ep->name, req);

        /* catch various bogus parameters */
        if (!req->req.complete || !req->req.buf
                        || !list_empty(&req->queue)) {
                dev_err(u3d->dev,
                        "%s, bad params, _req: 0x%p,"
                        "req->req.complete: 0x%p, req->req.buf: 0x%p,"
                        "list_empty: 0x%x\n",
                        __func__, _req,
                        req->req.complete, req->req.buf,
                        list_empty(&req->queue));
                return -EINVAL;
        }
        if (unlikely(!ep->ep.desc)) {
                dev_err(u3d->dev, "%s, bad ep\n", __func__);
                return -EINVAL;
        }
        if (ep->ep.desc->bmAttributes == USB_ENDPOINT_XFER_ISOC) {
                if (req->req.length > ep->ep.maxpacket)
                        return -EMSGSIZE;
        }

        if (!u3d->driver || u3d->gadget.speed == USB_SPEED_UNKNOWN) {
                dev_err(u3d->dev,
                        "bad params of driver/speed\n");
                return -ESHUTDOWN;
        }

        req->ep = ep;

        /* Software list handles usb request. */
        spin_lock_irqsave(&ep->req_lock, flags);
        is_first_req = list_empty(&ep->req_list);
        list_add_tail(&req->list, &ep->req_list);
        spin_unlock_irqrestore(&ep->req_lock, flags);
        if (!is_first_req) {
                dev_dbg(u3d->dev, "list is not empty\n");
                return 0;
        }

        dev_dbg(u3d->dev, "call mv_u3d_start_queue from usb_ep_queue\n");
        spin_lock_irqsave(&u3d->lock, flags);
        mv_u3d_start_queue(ep);
        spin_unlock_irqrestore(&u3d->lock, flags);
        return 0;
}

/* dequeues (cancels, unlinks) an I/O request from an endpoint */
static int mv_u3d_ep_dequeue(struct usb_ep *_ep, struct usb_request *_req)
{
        struct mv_u3d_ep *ep;
        struct mv_u3d_req *req;
        struct mv_u3d *u3d;
        struct mv_u3d_ep_context *ep_context;
        struct mv_u3d_req *next_req;

        unsigned long flags;
        int ret = 0;

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

        ep = container_of(_ep, struct mv_u3d_ep, ep);
        u3d = ep->u3d;

        spin_lock_irqsave(&ep->u3d->lock, flags);

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

        /* The request is in progress, or completed but not dequeued */
        if (ep->queue.next == &req->queue) {
                _req->status = -ECONNRESET;
                mv_u3d_ep_fifo_flush(_ep);

                /* The request isn't the last request in this ep queue */
                if (req->queue.next != &ep->queue) {
                        dev_dbg(u3d->dev,
                                "it is the last request in this ep queue\n");
                        ep_context = ep->ep_context;
                        next_req = list_entry(req->queue.next,
                                        struct mv_u3d_req, queue);

                        /* Point first TRB of next request to the EP context. */
                        iowrite32((unsigned long) next_req->trb_head,
                                        &ep_context->trb_addr_lo);
                } else {
                        struct mv_u3d_ep_context *ep_context;
                        ep_context = ep->ep_context;
                        ep_context->trb_addr_lo = 0;
                        ep_context->trb_addr_hi = 0;
                }

        } else
                WARN_ON(1);

        mv_u3d_done(ep, req, -ECONNRESET);

        /* remove the req from the ep req list */
        if (!list_empty(&ep->req_list)) {
                struct mv_u3d_req *curr_req;
                curr_req = list_entry(ep->req_list.next,
                                        struct mv_u3d_req, list);
                if (curr_req == req) {
                        list_del_init(&req->list);
                        ep->processing = 0;
                }
        }

out:
        spin_unlock_irqrestore(&ep->u3d->lock, flags);
        return ret;
}

static void
mv_u3d_ep_set_stall(struct mv_u3d *u3d, u8 ep_num, u8 direction, int stall)
{
        u32 tmp;
        struct mv_u3d_ep *ep = u3d->eps;

        dev_dbg(u3d->dev, "%s\n", __func__);
        if (direction == MV_U3D_EP_DIR_OUT) {
                tmp = ioread32(&u3d->vuc_regs->epcr[ep->ep_num].epxoutcr0);
                if (stall)
                        tmp |= MV_U3D_EPXCR_EP_HALT;
                else
                        tmp &= ~MV_U3D_EPXCR_EP_HALT;
                iowrite32(tmp, &u3d->vuc_regs->epcr[ep->ep_num].epxoutcr0);
        } else {
                tmp = ioread32(&u3d->vuc_regs->epcr[ep->ep_num].epxincr0);
                if (stall)
                        tmp |= MV_U3D_EPXCR_EP_HALT;
                else
                        tmp &= ~MV_U3D_EPXCR_EP_HALT;
                iowrite32(tmp, &u3d->vuc_regs->epcr[ep->ep_num].epxincr0);
        }
}

static int mv_u3d_ep_set_halt_wedge(struct usb_ep *_ep, int halt, int wedge)
{
        struct mv_u3d_ep *ep;
        unsigned long flags = 0;
        int status = 0;
        struct mv_u3d *u3d;

        ep = container_of(_ep, struct mv_u3d_ep, ep);
        u3d = ep->u3d;
        if (!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 && (mv_u3d_ep_dir(ep) == MV_U3D_EP_DIR_IN)
                        && !list_empty(&ep->queue)) {
                status = -EAGAIN;
                goto out;
        }

        spin_lock_irqsave(&ep->u3d->lock, flags);
        mv_u3d_ep_set_stall(u3d, ep->ep_num, mv_u3d_ep_dir(ep), halt);
        if (halt && wedge)
                ep->wedge = 1;
        else if (!halt)
                ep->wedge = 0;
        spin_unlock_irqrestore(&ep->u3d->lock, flags);

        if (ep->ep_num == 0)
                u3d->ep0_dir = MV_U3D_EP_DIR_OUT;
out:
        return status;
}

static int mv_u3d_ep_set_halt(struct usb_ep *_ep, int halt)
{
        return mv_u3d_ep_set_halt_wedge(_ep, halt, 0);
}

static int mv_u3d_ep_set_wedge(struct usb_ep *_ep)
{
        return mv_u3d_ep_set_halt_wedge(_ep, 1, 1);
}

static struct usb_ep_ops mv_u3d_ep_ops = {
        .enable         = mv_u3d_ep_enable,
        .disable        = mv_u3d_ep_disable,

        .alloc_request  = mv_u3d_alloc_request,
        .free_request   = mv_u3d_free_request,

        .queue          = mv_u3d_ep_queue,
        .dequeue        = mv_u3d_ep_dequeue,

        .set_wedge      = mv_u3d_ep_set_wedge,
        .set_halt       = mv_u3d_ep_set_halt,
        .fifo_flush     = mv_u3d_ep_fifo_flush,
};

static void mv_u3d_controller_stop(struct mv_u3d *u3d)
{
        u32 tmp;

        if (!u3d->clock_gating && u3d->vbus_valid_detect)
                iowrite32(MV_U3D_INTR_ENABLE_VBUS_VALID,
                                &u3d->vuc_regs->intrenable);
        else
                iowrite32(0, &u3d->vuc_regs->intrenable);
        iowrite32(~0x0, &u3d->vuc_regs->endcomplete);
        iowrite32(~0x0, &u3d->vuc_regs->trbunderrun);
        iowrite32(~0x0, &u3d->vuc_regs->trbcomplete);
        iowrite32(~0x0, &u3d->vuc_regs->linkchange);
        iowrite32(0x1, &u3d->vuc_regs->setuplock);

        /* Reset the RUN bit in the command register to stop USB */
        tmp = ioread32(&u3d->op_regs->usbcmd);
        tmp &= ~MV_U3D_CMD_RUN_STOP;
        iowrite32(tmp, &u3d->op_regs->usbcmd);
        dev_dbg(u3d->dev, "after u3d_stop, USBCMD 0x%x\n",
                ioread32(&u3d->op_regs->usbcmd));
}

static void mv_u3d_controller_start(struct mv_u3d *u3d)
{
        u32 usbintr;
        u32 temp;

        /* enable link LTSSM state machine */
        temp = ioread32(&u3d->vuc_regs->ltssm);
        temp |= MV_U3D_LTSSM_PHY_INIT_DONE;
        iowrite32(temp, &u3d->vuc_regs->ltssm);

        /* Enable interrupts */
        usbintr = MV_U3D_INTR_ENABLE_LINK_CHG | MV_U3D_INTR_ENABLE_TXDESC_ERR |
                MV_U3D_INTR_ENABLE_RXDESC_ERR | MV_U3D_INTR_ENABLE_TX_COMPLETE |
                MV_U3D_INTR_ENABLE_RX_COMPLETE | MV_U3D_INTR_ENABLE_SETUP |
                (u3d->vbus_valid_detect ? MV_U3D_INTR_ENABLE_VBUS_VALID : 0);
        iowrite32(usbintr, &u3d->vuc_regs->intrenable);

        /* Enable ctrl ep */
        iowrite32(0x1, &u3d->vuc_regs->ctrlepenable);

        /* Set the Run bit in the command register */
        iowrite32(MV_U3D_CMD_RUN_STOP, &u3d->op_regs->usbcmd);
        dev_dbg(u3d->dev, "after u3d_start, USBCMD 0x%x\n",
                ioread32(&u3d->op_regs->usbcmd));
}

static int mv_u3d_controller_reset(struct mv_u3d *u3d)
{
        unsigned int loops;
        u32 tmp;

        /* Stop the controller */
        tmp = ioread32(&u3d->op_regs->usbcmd);
        tmp &= ~MV_U3D_CMD_RUN_STOP;
        iowrite32(tmp, &u3d->op_regs->usbcmd);

        /* Reset the controller to get default values */
        iowrite32(MV_U3D_CMD_CTRL_RESET, &u3d->op_regs->usbcmd);

        /* wait for reset to complete */
        loops = LOOPS(MV_U3D_RESET_TIMEOUT);
        while (ioread32(&u3d->op_regs->usbcmd) & MV_U3D_CMD_CTRL_RESET) {
                if (loops == 0) {
                        dev_err(u3d->dev,
                                "Wait for RESET completed TIMEOUT\n");
                        return -ETIMEDOUT;
                }
                loops--;
                udelay(LOOPS_USEC);
        }

        /* Configure the Endpoint Context Address */
        iowrite32(u3d->ep_context_dma, &u3d->op_regs->dcbaapl);
        iowrite32(0, &u3d->op_regs->dcbaaph);

        return 0;
}

static int mv_u3d_enable(struct mv_u3d *u3d)
{
        struct mv_usb_platform_data *pdata = dev_get_platdata(u3d->dev);
        int retval;

        if (u3d->active)
                return 0;

        if (!u3d->clock_gating) {
                u3d->active = 1;
                return 0;
        }

        dev_dbg(u3d->dev, "enable u3d\n");
        clk_enable(u3d->clk);
        if (pdata->phy_init) {
                retval = pdata->phy_init(u3d->phy_regs);
                if (retval) {
                        dev_err(u3d->dev,
                                "init phy error %d\n", retval);
                        clk_disable(u3d->clk);
                        return retval;
                }
        }
        u3d->active = 1;

        return 0;
}

static void mv_u3d_disable(struct mv_u3d *u3d)
{
        struct mv_usb_platform_data *pdata = dev_get_platdata(u3d->dev);
        if (u3d->clock_gating && u3d->active) {
                dev_dbg(u3d->dev, "disable u3d\n");
                if (pdata->phy_deinit)
                        pdata->phy_deinit(u3d->phy_regs);
                clk_disable(u3d->clk);
                u3d->active = 0;
        }
}

static int mv_u3d_vbus_session(struct usb_gadget *gadget, int is_active)
{
        struct mv_u3d *u3d;
        unsigned long flags;
        int retval = 0;

        u3d = container_of(gadget, struct mv_u3d, gadget);

        spin_lock_irqsave(&u3d->lock, flags);

        u3d->vbus_active = (is_active != 0);
        dev_dbg(u3d->dev, "%s: softconnect %d, vbus_active %d\n",
                __func__, u3d->softconnect, u3d->vbus_active);
        /*
         * 1. external VBUS detect: we can disable/enable clock on demand.
         * 2. UDC VBUS detect: we have to enable clock all the time.
         * 3. No VBUS detect: we have to enable clock all the time.
         */
        if (u3d->driver && u3d->softconnect && u3d->vbus_active) {
                retval = mv_u3d_enable(u3d);
                if (retval == 0) {
                        /*
                         * after clock is disabled, we lost all the register
                         *  context. We have to re-init registers
                         */
                        mv_u3d_controller_reset(u3d);
                        mv_u3d_ep0_reset(u3d);
                        mv_u3d_controller_start(u3d);
                }
        } else if (u3d->driver && u3d->softconnect) {
                if (!u3d->active)
                        goto out;

                /* stop all the transfer in queue*/
                mv_u3d_stop_activity(u3d, u3d->driver);
                mv_u3d_controller_stop(u3d);
                mv_u3d_disable(u3d);
        }

out:
        spin_unlock_irqrestore(&u3d->lock, flags);
        return retval;
}

/* constrain controller's VBUS power usage
 * This call is used by gadget drivers during SET_CONFIGURATION calls,
 * reporting how much power the device may consume.  For example, this
 * could affect how quickly batteries are recharged.
 *
 * Returns zero on success, else negative errno.
 */
static int mv_u3d_vbus_draw(struct usb_gadget *gadget, unsigned mA)
{
        struct mv_u3d *u3d = container_of(gadget, struct mv_u3d, gadget);

        u3d->power = mA;

        return 0;
}

static int mv_u3d_pullup(struct usb_gadget *gadget, int is_on)
{
        struct mv_u3d *u3d = container_of(gadget, struct mv_u3d, gadget);
        unsigned long flags;
        int retval = 0;

        spin_lock_irqsave(&u3d->lock, flags);

        dev_dbg(u3d->dev, "%s: softconnect %d, vbus_active %d\n",
                __func__, u3d->softconnect, u3d->vbus_active);
        u3d->softconnect = (is_on != 0);
        if (u3d->driver && u3d->softconnect && u3d->vbus_active) {
                retval = mv_u3d_enable(u3d);
                if (retval == 0) {
                        /*
                         * after clock is disabled, we lost all the register
                         *  context. We have to re-init registers
                         */
                        mv_u3d_controller_reset(u3d);
                        mv_u3d_ep0_reset(u3d);
                        mv_u3d_controller_start(u3d);
                }
        } else if (u3d->driver && u3d->vbus_active) {
                /* stop all the transfer in queue*/
                mv_u3d_stop_activity(u3d, u3d->driver);
                mv_u3d_controller_stop(u3d);
                mv_u3d_disable(u3d);
        }

        spin_unlock_irqrestore(&u3d->lock, flags);

        return retval;
}

static int mv_u3d_start(struct usb_gadget *g,
                struct usb_gadget_driver *driver)
{
        struct mv_u3d *u3d = container_of(g, struct mv_u3d, gadget);
        struct mv_usb_platform_data *pdata = dev_get_platdata(u3d->dev);
        unsigned long flags;

        if (u3d->driver)
                return -EBUSY;

        spin_lock_irqsave(&u3d->lock, flags);

        if (!u3d->clock_gating) {
                clk_enable(u3d->clk);
                if (pdata->phy_init)
                        pdata->phy_init(u3d->phy_regs);
        }

        /* hook up the driver ... */
        driver->driver.bus = NULL;
        u3d->driver = driver;

        u3d->ep0_dir = USB_DIR_OUT;

        spin_unlock_irqrestore(&u3d->lock, flags);

        u3d->vbus_valid_detect = 1;

        return 0;
}

static int mv_u3d_stop(struct usb_gadget *g)
{
        struct mv_u3d *u3d = container_of(g, struct mv_u3d, gadget);
        struct mv_usb_platform_data *pdata = dev_get_platdata(u3d->dev);
        unsigned long flags;

        u3d->vbus_valid_detect = 0;
        spin_lock_irqsave(&u3d->lock, flags);

        /* enable clock to access controller register */
        clk_enable(u3d->clk);
        if (pdata->phy_init)
                pdata->phy_init(u3d->phy_regs);

        mv_u3d_controller_stop(u3d);
        /* stop all usb activities */
        u3d->gadget.speed = USB_SPEED_UNKNOWN;
        mv_u3d_stop_activity(u3d, NULL);
        mv_u3d_disable(u3d);

        if (pdata->phy_deinit)
                pdata->phy_deinit(u3d->phy_regs);
        clk_disable(u3d->clk);

        spin_unlock_irqrestore(&u3d->lock, flags);

        u3d->driver = NULL;

        return 0;
}

/* device controller usb_gadget_ops structure */
static const struct usb_gadget_ops mv_u3d_ops = {
        /* notify controller that VBUS is powered or not */
        .vbus_session   = mv_u3d_vbus_session,

        /* constrain controller's VBUS power usage */
        .vbus_draw      = mv_u3d_vbus_draw,

        .pullup         = mv_u3d_pullup,
        .udc_start      = mv_u3d_start,
        .udc_stop       = mv_u3d_stop,
};

static int mv_u3d_eps_init(struct mv_u3d *u3d)
{
        struct mv_u3d_ep        *ep;
        char name[14];
        int i;

        /* initialize ep0, ep0 in/out use eps[1] */
        ep = &u3d->eps[1];
        ep->u3d = u3d;
        strncpy(ep->name, "ep0", sizeof(ep->name));
        ep->ep.name = ep->name;
        ep->ep.ops = &mv_u3d_ep_ops;
        ep->wedge = 0;
        usb_ep_set_maxpacket_limit(&ep->ep, MV_U3D_EP0_MAX_PKT_SIZE);
        ep->ep_num = 0;
        ep->ep.desc = &mv_u3d_ep0_desc;
        INIT_LIST_HEAD(&ep->queue);
        INIT_LIST_HEAD(&ep->req_list);
        ep->ep_type = USB_ENDPOINT_XFER_CONTROL;

        /* add ep0 ep_context */
        ep->ep_context = &u3d->ep_context[1];

        /* initialize other endpoints */
        for (i = 2; i < u3d->max_eps * 2; i++) {
                ep = &u3d->eps[i];
                if (i & 1) {
                        snprintf(name, sizeof(name), "ep%din", i >> 1);
                        ep->direction = MV_U3D_EP_DIR_IN;
                } else {
                        snprintf(name, sizeof(name), "ep%dout", i >> 1);
                        ep->direction = MV_U3D_EP_DIR_OUT;
                }
                ep->u3d = u3d;
                strncpy(ep->name, name, sizeof(ep->name));
                ep->ep.name = ep->name;

                ep->ep.ops = &mv_u3d_ep_ops;
                usb_ep_set_maxpacket_limit(&ep->ep, (unsigned short) ~0);
                ep->ep_num = i / 2;

                INIT_LIST_HEAD(&ep->queue);
                list_add_tail(&ep->ep.ep_list, &u3d->gadget.ep_list);

                INIT_LIST_HEAD(&ep->req_list);
                spin_lock_init(&ep->req_lock);
                ep->ep_context = &u3d->ep_context[i];
        }

        return 0;
}

/* delete all endpoint requests, called with spinlock held */
static void mv_u3d_nuke(struct mv_u3d_ep *ep, int status)
{
        /* endpoint fifo flush */
        mv_u3d_ep_fifo_flush(&ep->ep);

        while (!list_empty(&ep->queue)) {
                struct mv_u3d_req *req = NULL;
                req = list_entry(ep->queue.next, struct mv_u3d_req, queue);
                mv_u3d_done(ep, req, status);
        }
}

/* stop all USB activities */
static
void mv_u3d_stop_activity(struct mv_u3d *u3d, struct usb_gadget_driver *driver)
{
        struct mv_u3d_ep        *ep;

        mv_u3d_nuke(&u3d->eps[1], -ESHUTDOWN);

        list_for_each_entry(ep, &u3d->gadget.ep_list, ep.ep_list) {
                mv_u3d_nuke(ep, -ESHUTDOWN);
        }

        /* report disconnect; the driver is already quiesced */
        if (driver) {
                spin_unlock(&u3d->lock);
                driver->disconnect(&u3d->gadget);
                spin_lock(&u3d->lock);
        }
}

static void mv_u3d_irq_process_error(struct mv_u3d *u3d)
{
        /* Increment the error count */
        u3d->errors++;
        dev_err(u3d->dev, "%s\n", __func__);
}

static void mv_u3d_irq_process_link_change(struct mv_u3d *u3d)
{
        u32 linkchange;

        linkchange = ioread32(&u3d->vuc_regs->linkchange);
        iowrite32(linkchange, &u3d->vuc_regs->linkchange);

        dev_dbg(u3d->dev, "linkchange: 0x%x\n", linkchange);

        if (linkchange & MV_U3D_LINK_CHANGE_LINK_UP) {
                dev_dbg(u3d->dev, "link up: ltssm state: 0x%x\n",
                        ioread32(&u3d->vuc_regs->ltssmstate));

                u3d->usb_state = USB_STATE_DEFAULT;
                u3d->ep0_dir = MV_U3D_EP_DIR_OUT;
                u3d->ep0_state = MV_U3D_WAIT_FOR_SETUP;

                /* set speed */
                u3d->gadget.speed = USB_SPEED_SUPER;
        }

        if (linkchange & MV_U3D_LINK_CHANGE_SUSPEND) {
                dev_dbg(u3d->dev, "link suspend\n");
                u3d->resume_state = u3d->usb_state;
                u3d->usb_state = USB_STATE_SUSPENDED;
        }

        if (linkchange & MV_U3D_LINK_CHANGE_RESUME) {
                dev_dbg(u3d->dev, "link resume\n");
                u3d->usb_state = u3d->resume_state;
                u3d->resume_state = 0;
        }

        if (linkchange & MV_U3D_LINK_CHANGE_WRESET) {
                dev_dbg(u3d->dev, "warm reset\n");
                u3d->usb_state = USB_STATE_POWERED;
        }

        if (linkchange & MV_U3D_LINK_CHANGE_HRESET) {
                dev_dbg(u3d->dev, "hot reset\n");
                u3d->usb_state = USB_STATE_DEFAULT;
        }

        if (linkchange & MV_U3D_LINK_CHANGE_INACT)
                dev_dbg(u3d->dev, "inactive\n");

        if (linkchange & MV_U3D_LINK_CHANGE_DISABLE_AFTER_U0)
                dev_dbg(u3d->dev, "ss.disabled\n");

        if (linkchange & MV_U3D_LINK_CHANGE_VBUS_INVALID) {
                dev_dbg(u3d->dev, "vbus invalid\n");
                u3d->usb_state = USB_STATE_ATTACHED;
                u3d->vbus_valid_detect = 1;
                /* if external vbus detect is not supported,
                 * we handle it here.
                 */
                if (!u3d->vbus) {
                        spin_unlock(&u3d->lock);
                        mv_u3d_vbus_session(&u3d->gadget, 0);
                        spin_lock(&u3d->lock);
                }
        }
}

static void mv_u3d_ch9setaddress(struct mv_u3d *u3d,
                                struct usb_ctrlrequest *setup)
{
        u32 tmp;

        if (u3d->usb_state != USB_STATE_DEFAULT) {
                dev_err(u3d->dev,
                        "%s, cannot setaddr in this state (%d)\n",
                        __func__, u3d->usb_state);
                goto err;
        }

        u3d->dev_addr = (u8)setup->wValue;

        dev_dbg(u3d->dev, "%s: 0x%x\n", __func__, u3d->dev_addr);

        if (u3d->dev_addr > 127) {
                dev_err(u3d->dev,
                        "%s, u3d address is wrong (out of range)\n", __func__);
                u3d->dev_addr = 0;
                goto err;
        }

        /* update usb state */
        u3d->usb_state = USB_STATE_ADDRESS;

        /* set the new address */
        tmp = ioread32(&u3d->vuc_regs->devaddrtiebrkr);
        tmp &= ~0x7F;
        tmp |= (u32)u3d->dev_addr;
        iowrite32(tmp, &u3d->vuc_regs->devaddrtiebrkr);

        return;
err:
        mv_u3d_ep0_stall(u3d);
}

static int mv_u3d_is_set_configuration(struct usb_ctrlrequest *setup)
{
        if ((setup->bRequestType & USB_TYPE_MASK) == USB_TYPE_STANDARD)
                if (setup->bRequest == USB_REQ_SET_CONFIGURATION)
                        return 1;

        return 0;
}

static void mv_u3d_handle_setup_packet(struct mv_u3d *u3d, u8 ep_num,
        struct usb_ctrlrequest *setup)
        __releases(&u3c->lock)
        __acquires(&u3c->lock)
{
        bool delegate = false;

        mv_u3d_nuke(&u3d->eps[ep_num * 2 + MV_U3D_EP_DIR_IN], -ESHUTDOWN);

        dev_dbg(u3d->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:
                        delegate = true;
                        break;

                case USB_REQ_SET_ADDRESS:
                        mv_u3d_ch9setaddress(u3d, setup);
                        break;

                case USB_REQ_CLEAR_FEATURE:
                        delegate = true;
                        break;

                case USB_REQ_SET_FEATURE:
                        delegate = true;
                        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 u3d */
                        u3d->ep0_dir = (setup->bRequestType & USB_DIR_IN)
                                        ? MV_U3D_EP_DIR_IN : MV_U3D_EP_DIR_OUT;
                        spin_unlock(&u3d->lock);
                        if (u3d->driver->setup(&u3d->gadget,
                                &u3d->local_setup_buff) < 0) {
                                dev_err(u3d->dev, "setup error!\n");
                                mv_u3d_ep0_stall(u3d);
                        }
                        spin_lock(&u3d->lock);
                } else {
                        /* no DATA phase, STATUS phase from gadget */
                        u3d->ep0_dir = MV_U3D_EP_DIR_IN;
                        u3d->ep0_state = MV_U3D_STATUS_STAGE;
                        spin_unlock(&u3d->lock);
                        if (u3d->driver->setup(&u3d->gadget,
                                &u3d->local_setup_buff) < 0)
                                mv_u3d_ep0_stall(u3d);
                        spin_lock(&u3d->lock);
                }

                if (mv_u3d_is_set_configuration(setup)) {
                        dev_dbg(u3d->dev, "u3d configured\n");
                        u3d->usb_state = USB_STATE_CONFIGURED;
                }
        }
}

static void mv_u3d_get_setup_data(struct mv_u3d *u3d, u8 ep_num, u8 *buffer_ptr)
{
        struct mv_u3d_ep_context *epcontext;

        epcontext = &u3d->ep_context[ep_num * 2 + MV_U3D_EP_DIR_IN];

        /* Copy the setup packet to local buffer */
        memcpy(buffer_ptr, (u8 *) &epcontext->setup_buffer, 8);
}

static void mv_u3d_irq_process_setup(struct mv_u3d *u3d)
{
        u32 tmp, i;
        /* Process all Setup packet received interrupts */
        tmp = ioread32(&u3d->vuc_regs->setuplock);
        if (tmp) {
                for (i = 0; i < u3d->max_eps; i++) {
                        if (tmp & (1 << i)) {
                                mv_u3d_get_setup_data(u3d, i,
                                        (u8 *)(&u3d->local_setup_buff));
                                mv_u3d_handle_setup_packet(u3d, i,
                                        &u3d->local_setup_buff);
                        }
                }
        }

        iowrite32(tmp, &u3d->vuc_regs->setuplock);
}

static void mv_u3d_irq_process_tr_complete(struct mv_u3d *u3d)
{
        u32 tmp, bit_pos;
        int i, ep_num = 0, direction = 0;
        struct mv_u3d_ep        *curr_ep;
        struct mv_u3d_req *curr_req, *temp_req;
        int status;

        tmp = ioread32(&u3d->vuc_regs->endcomplete);

        dev_dbg(u3d->dev, "tr_complete: ep: 0x%x\n", tmp);
        if (!tmp)
                return;
        iowrite32(tmp, &u3d->vuc_regs->endcomplete);

        for (i = 0; i < u3d->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 == 0)
                        curr_ep = &u3d->eps[1];
                else
                        curr_ep = &u3d->eps[i];

                /* remove req out of ep request list after completion */
                dev_dbg(u3d->dev, "tr comp: check req_list\n");
                spin_lock(&curr_ep->req_lock);
                if (!list_empty(&curr_ep->req_list)) {
                        struct mv_u3d_req *req;
                        req = list_entry(curr_ep->req_list.next,
                                                struct mv_u3d_req, list);
                        list_del_init(&req->list);
                        curr_ep->processing = 0;
                }
                spin_unlock(&curr_ep->req_lock);

                /* process the req queue until an uncomplete request */
                list_for_each_entry_safe(curr_req, temp_req,
                        &curr_ep->queue, queue) {
                        status = mv_u3d_process_ep_req(u3d, i, curr_req);
                        if (status)
                                break;
                        /* write back status to req */
                        curr_req->req.status = status;

                        /* ep0 request completion */
                        if (ep_num == 0) {
                                mv_u3d_done(curr_ep, curr_req, 0);
                                break;
                        } else {
                                mv_u3d_done(curr_ep, curr_req, status);
                        }
                }

                dev_dbg(u3d->dev, "call mv_u3d_start_queue from ep complete\n");
                mv_u3d_start_queue(curr_ep);
        }
}

static irqreturn_t mv_u3d_irq(int irq, void *dev)
{
        struct mv_u3d *u3d = (struct mv_u3d *)dev;
        u32 status, intr;
        u32 bridgesetting;
        u32 trbunderrun;

        spin_lock(&u3d->lock);

        status = ioread32(&u3d->vuc_regs->intrcause);
        intr = ioread32(&u3d->vuc_regs->intrenable);
        status &= intr;

        if (status == 0) {
                spin_unlock(&u3d->lock);
                dev_err(u3d->dev, "irq error!\n");
                return IRQ_NONE;
        }

        if (status & MV_U3D_USBINT_VBUS_VALID) {
                bridgesetting = ioread32(&u3d->vuc_regs->bridgesetting);
                if (bridgesetting & MV_U3D_BRIDGE_SETTING_VBUS_VALID) {
                        /* write vbus valid bit of bridge setting to clear */
                        bridgesetting = MV_U3D_BRIDGE_SETTING_VBUS_VALID;
                        iowrite32(bridgesetting, &u3d->vuc_regs->bridgesetting);
                        dev_dbg(u3d->dev, "vbus valid\n");

                        u3d->usb_state = USB_STATE_POWERED;
                        u3d->vbus_valid_detect = 0;
                        /* if external vbus detect is not supported,
                         * we handle it here.
                         */
                        if (!u3d->vbus) {
                                spin_unlock(&u3d->lock);
                                mv_u3d_vbus_session(&u3d->gadget, 1);
                                spin_lock(&u3d->lock);
                        }
                } else
                        dev_err(u3d->dev, "vbus bit is not set\n");
        }

        /* RX data is already in the 16KB FIFO.*/
        if (status & MV_U3D_USBINT_UNDER_RUN) {
                trbunderrun = ioread32(&u3d->vuc_regs->trbunderrun);
                dev_err(u3d->dev, "under run, ep%d\n", trbunderrun);
                iowrite32(trbunderrun, &u3d->vuc_regs->trbunderrun);
                mv_u3d_irq_process_error(u3d);
        }

        if (status & (MV_U3D_USBINT_RXDESC_ERR | MV_U3D_USBINT_TXDESC_ERR)) {
                /* write one to clear */
                iowrite32(status & (MV_U3D_USBINT_RXDESC_ERR
                        | MV_U3D_USBINT_TXDESC_ERR),
                        &u3d->vuc_regs->intrcause);
                dev_err(u3d->dev, "desc err 0x%x\n", status);
                mv_u3d_irq_process_error(u3d);
        }

        if (status & MV_U3D_USBINT_LINK_CHG)
                mv_u3d_irq_process_link_change(u3d);

        if (status & MV_U3D_USBINT_TX_COMPLETE)
                mv_u3d_irq_process_tr_complete(u3d);

        if (status & MV_U3D_USBINT_RX_COMPLETE)
                mv_u3d_irq_process_tr_complete(u3d);

        if (status & MV_U3D_USBINT_SETUP)
                mv_u3d_irq_process_setup(u3d);

        spin_unlock(&u3d->lock);
        return IRQ_HANDLED;
}

static int mv_u3d_remove(struct platform_device *dev)
{
        struct mv_u3d *u3d = platform_get_drvdata(dev);

        BUG_ON(u3d == NULL);

        usb_del_gadget_udc(&u3d->gadget);

        /* free memory allocated in probe */
        if (u3d->trb_pool)
                dma_pool_destroy(u3d->trb_pool);

        if (u3d->ep_context)
                dma_free_coherent(&dev->dev, u3d->ep_context_size,
                        u3d->ep_context, u3d->ep_context_dma);

        kfree(u3d->eps);

        if (u3d->irq)
                free_irq(u3d->irq, u3d);

        if (u3d->cap_regs)
                iounmap(u3d->cap_regs);
        u3d->cap_regs = NULL;

        kfree(u3d->status_req);

        clk_put(u3d->clk);

        kfree(u3d);

        return 0;
}

static int mv_u3d_probe(struct platform_device *dev)
{
        struct mv_u3d *u3d = NULL;
        struct mv_usb_platform_data *pdata = dev_get_platdata(&dev->dev);
        int retval = 0;
        struct resource *r;
        size_t size;

        if (!dev_get_platdata(&dev->dev)) {
                dev_err(&dev->dev, "missing platform_data\n");
                retval = -ENODEV;
                goto err_pdata;
        }

        u3d = kzalloc(sizeof(*u3d), GFP_KERNEL);
        if (!u3d) {
                retval = -ENOMEM;
                goto err_alloc_private;
        }

        spin_lock_init(&u3d->lock);

        platform_set_drvdata(dev, u3d);

        u3d->dev = &dev->dev;
        u3d->vbus = pdata->vbus;

        u3d->clk = clk_get(&dev->dev, NULL);
        if (IS_ERR(u3d->clk)) {
                retval = PTR_ERR(u3d->clk);
                goto err_get_clk;
        }

        r = platform_get_resource_byname(dev, IORESOURCE_MEM, "capregs");
        if (!r) {
                dev_err(&dev->dev, "no I/O memory resource defined\n");
                retval = -ENODEV;
                goto err_get_cap_regs;
        }

        u3d->cap_regs = (struct mv_u3d_cap_regs __iomem *)
                ioremap(r->start, resource_size(r));
        if (!u3d->cap_regs) {
                dev_err(&dev->dev, "failed to map I/O memory\n");
                retval = -EBUSY;
                goto err_map_cap_regs;
        } else {
                dev_dbg(&dev->dev, "cap_regs address: 0x%lx/0x%lx\n",
                        (unsigned long) r->start,
                        (unsigned long) u3d->cap_regs);
        }

        /* we will access controller register, so enable the u3d controller */
        clk_enable(u3d->clk);

        if (pdata->phy_init) {
                retval = pdata->phy_init(u3d->phy_regs);
                if (retval) {
                        dev_err(&dev->dev, "init phy error %d\n", retval);
                        goto err_u3d_enable;
                }
        }

        u3d->op_regs = (struct mv_u3d_op_regs __iomem *)(u3d->cap_regs
                + MV_U3D_USB3_OP_REGS_OFFSET);

        u3d->vuc_regs = (struct mv_u3d_vuc_regs __iomem *)(u3d->cap_regs
                + ioread32(&u3d->cap_regs->vuoff));

        u3d->max_eps = 16;

        /*
         * some platform will use usb to download image, it may not disconnect
         * usb gadget before loading kernel. So first stop u3d here.
         */
        mv_u3d_controller_stop(u3d);
        iowrite32(0xFFFFFFFF, &u3d->vuc_regs->intrcause);

        if (pdata->phy_deinit)
                pdata->phy_deinit(u3d->phy_regs);
        clk_disable(u3d->clk);

        size = u3d->max_eps * sizeof(struct mv_u3d_ep_context) * 2;
        size = (size + MV_U3D_EP_CONTEXT_ALIGNMENT - 1)
                & ~(MV_U3D_EP_CONTEXT_ALIGNMENT - 1);
        u3d->ep_context = dma_alloc_coherent(&dev->dev, size,
                                        &u3d->ep_context_dma, GFP_KERNEL);
        if (!u3d->ep_context) {
                dev_err(&dev->dev, "allocate ep context memory failed\n");
                retval = -ENOMEM;
                goto err_alloc_ep_context;
        }
        u3d->ep_context_size = size;

        /* create TRB dma_pool resource */
        u3d->trb_pool = dma_pool_create("u3d_trb",
                        &dev->dev,
                        sizeof(struct mv_u3d_trb_hw),
                        MV_U3D_TRB_ALIGNMENT,
                        MV_U3D_DMA_BOUNDARY);

        if (!u3d->trb_pool) {
                retval = -ENOMEM;
                goto err_alloc_trb_pool;
        }

        size = u3d->max_eps * sizeof(struct mv_u3d_ep) * 2;
        u3d->eps = kzalloc(size, GFP_KERNEL);
        if (!u3d->eps) {
                retval = -ENOMEM;
                goto err_alloc_eps;
        }

        /* initialize ep0 status request structure */
        u3d->status_req = kzalloc(sizeof(struct mv_u3d_req) + 8, GFP_KERNEL);
        if (!u3d->status_req) {
                retval = -ENOMEM;
                goto err_alloc_status_req;
        }
        INIT_LIST_HEAD(&u3d->status_req->queue);

        /* allocate a small amount of memory to get valid address */
        u3d->status_req->req.buf = (char *)u3d->status_req
                                        + sizeof(struct mv_u3d_req);
        u3d->status_req->req.dma = virt_to_phys(u3d->status_req->req.buf);

        u3d->resume_state = USB_STATE_NOTATTACHED;
        u3d->usb_state = USB_STATE_ATTACHED;
        u3d->ep0_dir = MV_U3D_EP_DIR_OUT;
        u3d->remote_wakeup = 0;

        r = platform_get_resource(dev, IORESOURCE_IRQ, 0);
        if (!r) {
                dev_err(&dev->dev, "no IRQ resource defined\n");
                retval = -ENODEV;
                goto err_get_irq;
        }
        u3d->irq = r->start;
        if (request_irq(u3d->irq, mv_u3d_irq,
                IRQF_SHARED, driver_name, u3d)) {
                u3d->irq = 0;
                dev_err(&dev->dev, "Request irq %d for u3d failed\n",
                        u3d->irq);
                retval = -ENODEV;
                goto err_request_irq;
        }

        /* initialize gadget structure */
        u3d->gadget.ops = &mv_u3d_ops;  /* usb_gadget_ops */
        u3d->gadget.ep0 = &u3d->eps[1].ep;      /* gadget ep0 */
        INIT_LIST_HEAD(&u3d->gadget.ep_list);   /* ep_list */
        u3d->gadget.speed = USB_SPEED_UNKNOWN;  /* speed */

        /* the "gadget" abstracts/virtualizes the controller */
        u3d->gadget.name = driver_name;         /* gadget name */

        mv_u3d_eps_init(u3d);

        /* external vbus detection */
        if (u3d->vbus) {
                u3d->clock_gating = 1;
                dev_err(&dev->dev, "external vbus detection\n");
        }

        if (!u3d->clock_gating)
                u3d->vbus_active = 1;

        /* enable usb3 controller vbus detection */
        u3d->vbus_valid_detect = 1;

        retval = usb_add_gadget_udc(&dev->dev, &u3d->gadget);
        if (retval)
                goto err_unregister;

        dev_dbg(&dev->dev, "successful probe usb3 device %s clock gating.\n",
                u3d->clock_gating ? "with" : "without");

        return 0;

err_unregister:
        free_irq(u3d->irq, u3d);
err_request_irq:
err_get_irq:
        kfree(u3d->status_req);
err_alloc_status_req:
        kfree(u3d->eps);
err_alloc_eps:
        dma_pool_destroy(u3d->trb_pool);
err_alloc_trb_pool:
        dma_free_coherent(&dev->dev, u3d->ep_context_size,
                u3d->ep_context, u3d->ep_context_dma);
err_alloc_ep_context:
        if (pdata->phy_deinit)
                pdata->phy_deinit(u3d->phy_regs);
        clk_disable(u3d->clk);
err_u3d_enable:
        iounmap(u3d->cap_regs);
err_map_cap_regs:
err_get_cap_regs:
err_get_clk:
        clk_put(u3d->clk);
        kfree(u3d);
err_alloc_private:
err_pdata:
        return retval;
}

#ifdef CONFIG_PM_SLEEP
static int mv_u3d_suspend(struct device *dev)
{
        struct mv_u3d *u3d = dev_get_drvdata(dev);

        /*
         * only cable is unplugged, usb can suspend.
         * So do not care about clock_gating == 1, it is handled by

         * vbus session.
         */
        if (!u3d->clock_gating) {
                mv_u3d_controller_stop(u3d);

                spin_lock_irq(&u3d->lock);
                /* stop all usb activities */
                mv_u3d_stop_activity(u3d, u3d->driver);
                spin_unlock_irq(&u3d->lock);

                mv_u3d_disable(u3d);
        }

        return 0;
}

static int mv_u3d_resume(struct device *dev)
{
        struct mv_u3d *u3d = dev_get_drvdata(dev);
        int retval;

        if (!u3d->clock_gating) {
                retval = mv_u3d_enable(u3d);
                if (retval)
                        return retval;

                if (u3d->driver && u3d->softconnect) {
                        mv_u3d_controller_reset(u3d);
                        mv_u3d_ep0_reset(u3d);
                        mv_u3d_controller_start(u3d);
                }
        }

        return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(mv_u3d_pm_ops, mv_u3d_suspend, mv_u3d_resume);

static void mv_u3d_shutdown(struct platform_device *dev)
{
        struct mv_u3d *u3d = platform_get_drvdata(dev);
        u32 tmp;

        tmp = ioread32(&u3d->op_regs->usbcmd);
        tmp &= ~MV_U3D_CMD_RUN_STOP;
        iowrite32(tmp, &u3d->op_regs->usbcmd);
}

static struct platform_driver mv_u3d_driver = {
        .probe          = mv_u3d_probe,
        .remove         = mv_u3d_remove,
        .shutdown       = mv_u3d_shutdown,
        .driver         = {
                .name   = "mv-u3d",
                .pm     = &mv_u3d_pm_ops,
        },
};

module_platform_driver(mv_u3d_driver);
MODULE_ALIAS("platform:mv-u3d");
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_AUTHOR("Yu Xu <yuxu@marvell.com>");
MODULE_LICENSE("GPL");