/*
 * Faraday USB 2.0 OTG Controller
 *
 * (C) Copyright 2010 Faraday Technology
 * Dante Su <dantesu@faraday-tech.com>
 *
 * SPDX-License-Identifier:     GPL-2.0+
 */

#include <common.h>
#include <command.h>
#include <config.h>
#include <net.h>
#include <malloc.h>
#include <asm/io.h>
#include <asm/errno.h>
#include <linux/types.h>
#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>

#include <usb/fotg210.h>

#define CFG_NUM_ENDPOINTS               4
#define CFG_EP0_MAX_PACKET_SIZE 64
#define CFG_EPX_MAX_PACKET_SIZE 512

#define CFG_CMD_TIMEOUT (CONFIG_SYS_HZ >> 2) /* 250 ms */

struct fotg210_chip;

struct fotg210_ep {
        struct usb_ep ep;

        uint maxpacket;
        uint id;
        uint stopped;

        struct list_head                      queue;
        struct fotg210_chip                  *chip;
        const struct usb_endpoint_descriptor *desc;
};

struct fotg210_request {
        struct usb_request req;
        struct list_head   queue;
        struct fotg210_ep *ep;
};

struct fotg210_chip {
        struct usb_gadget         gadget;
        struct usb_gadget_driver *driver;
        struct fotg210_regs      *regs;
        uint8_t                   irq;
        uint16_t                  addr;
        int                       pullup;
        enum usb_device_state     state;
        struct fotg210_ep         ep[1 + CFG_NUM_ENDPOINTS];
};

static struct usb_endpoint_descriptor ep0_desc = {
        .bLength = sizeof(struct usb_endpoint_descriptor),
        .bDescriptorType = USB_DT_ENDPOINT,
        .bEndpointAddress = USB_DIR_IN,
        .bmAttributes = USB_ENDPOINT_XFER_CONTROL,
};

static inline int fifo_to_ep(struct fotg210_chip *chip, int id, int in)
{
        return (id < 0) ? 0 : ((id & 0x03) + 1);
}

static inline int ep_to_fifo(struct fotg210_chip *chip, int id)
{
        return (id <= 0) ? -1 : ((id - 1) & 0x03);
}

static inline int ep_reset(struct fotg210_chip *chip, uint8_t ep_addr)
{
        int ep = ep_addr & USB_ENDPOINT_NUMBER_MASK;
        struct fotg210_regs *regs = chip->regs;

        if (ep_addr & USB_DIR_IN) {
                /* reset endpoint */
                setbits_le32(&regs->iep[ep - 1], IEP_RESET);
                mdelay(1);
                clrbits_le32(&regs->iep[ep - 1], IEP_RESET);
                /* clear endpoint stall */
                clrbits_le32(&regs->iep[ep - 1], IEP_STALL);
        } else {
                /* reset endpoint */
                setbits_le32(&regs->oep[ep - 1], OEP_RESET);
                mdelay(1);
                clrbits_le32(&regs->oep[ep - 1], OEP_RESET);
                /* clear endpoint stall */
                clrbits_le32(&regs->oep[ep - 1], OEP_STALL);
        }

        return 0;
}

static int fotg210_reset(struct fotg210_chip *chip)
{
        struct fotg210_regs *regs = chip->regs;
        uint32_t i;

        chip->state = USB_STATE_POWERED;

        /* chip enable */
        writel(DEVCTRL_EN, &regs->dev_ctrl);

        /* device address reset */
        chip->addr = 0;
        writel(0, &regs->dev_addr);

        /* set idle counter to 7ms */
        writel(7, &regs->idle);

        /* disable all interrupts */
        writel(IMR_MASK, &regs->imr);
        writel(GIMR_MASK, &regs->gimr);
        writel(GIMR0_MASK, &regs->gimr0);
        writel(GIMR1_MASK, &regs->gimr1);
        writel(GIMR2_MASK, &regs->gimr2);

        /* clear interrupts */
        writel(ISR_MASK, &regs->isr);
        writel(0, &regs->gisr);
        writel(0, &regs->gisr0);
        writel(0, &regs->gisr1);
        writel(0, &regs->gisr2);

        /* chip reset */
        setbits_le32(&regs->dev_ctrl, DEVCTRL_RESET);
        mdelay(10);
        if (readl(&regs->dev_ctrl) & DEVCTRL_RESET) {
                printf("fotg210: chip reset failed\n");
                return -1;
        }

        /* CX FIFO reset */
        setbits_le32(&regs->cxfifo, CXFIFO_CXFIFOCLR);
        mdelay(10);
        if (readl(&regs->cxfifo) & CXFIFO_CXFIFOCLR) {
                printf("fotg210: ep0 fifo reset failed\n");
                return -1;
        }

        /* create static ep-fifo map (EP1 <-> FIFO0, EP2 <-> FIFO1 ...) */
        writel(EPMAP14_DEFAULT, &regs->epmap14);
        writel(EPMAP58_DEFAULT, &regs->epmap58);
        writel(FIFOMAP_DEFAULT, &regs->fifomap);
        writel(0, &regs->fifocfg);
        for (i = 0; i < 8; ++i) {
                writel(CFG_EPX_MAX_PACKET_SIZE, &regs->iep[i]);
                writel(CFG_EPX_MAX_PACKET_SIZE, &regs->oep[i]);
        }

        /* FIFO reset */
        for (i = 0; i < 4; ++i) {
                writel(FIFOCSR_RESET, &regs->fifocsr[i]);
                mdelay(10);
                if (readl(&regs->fifocsr[i]) & FIFOCSR_RESET) {
                        printf("fotg210: fifo%d reset failed\n", i);
                        return -1;
                }
        }

        /* enable only device interrupt and triggered at level-high */
        writel(IMR_IRQLH | IMR_HOST | IMR_OTG, &regs->imr);
        writel(ISR_MASK, &regs->isr);
        /* disable EP0 IN/OUT interrupt */
        writel(GIMR0_CXOUT | GIMR0_CXIN, &regs->gimr0);
        /* disable EPX IN+SPK+OUT interrupts */
        writel(GIMR1_MASK, &regs->gimr1);
        /* disable wakeup+idle+dma+zlp interrupts */
        writel(GIMR2_WAKEUP | GIMR2_IDLE | GIMR2_DMAERR | GIMR2_DMAFIN
                | GIMR2_ZLPRX | GIMR2_ZLPTX, &regs->gimr2);
        /* enable all group interrupt */
        writel(0, &regs->gimr);

        /* suspend delay = 3 ms */
        writel(3, &regs->idle);

        /* turn-on device interrupts */
        setbits_le32(&regs->dev_ctrl, DEVCTRL_GIRQ_EN);

        return 0;
}

static inline int fotg210_cxwait(struct fotg210_chip *chip, uint32_t mask)
{
        struct fotg210_regs *regs = chip->regs;
        int ret = -1;
        ulong ts;

        for (ts = get_timer(0); get_timer(ts) < CFG_CMD_TIMEOUT; ) {
                if ((readl(&regs->cxfifo) & mask) != mask)
                        continue;
                ret = 0;
                break;
        }

        if (ret)
                printf("fotg210: cx/ep0 timeout\n");

        return ret;
}

static int fotg210_dma(struct fotg210_ep *ep, struct fotg210_request *req)
{
        struct fotg210_chip *chip = ep->chip;
        struct fotg210_regs *regs = chip->regs;
        uint32_t tmp, ts;
        uint8_t *buf  = req->req.buf + req->req.actual;
        uint32_t len  = req->req.length - req->req.actual;
        int fifo = ep_to_fifo(chip, ep->id);
        int ret = -EBUSY;

        /* 1. init dma buffer */
        if (len > ep->maxpacket)
                len = ep->maxpacket;

        /* 2. wait for dma ready (hardware) */
        for (ts = get_timer(0); get_timer(ts) < CFG_CMD_TIMEOUT; ) {
                if (!(readl(&regs->dma_ctrl) & DMACTRL_START)) {
                        ret = 0;
                        break;
                }
        }
        if (ret) {
                printf("fotg210: dma busy\n");
                req->req.status = ret;
                return ret;
        }

        /* 3. DMA target setup */
        if (ep->desc->bEndpointAddress & USB_DIR_IN)
                flush_dcache_range((ulong)buf, (ulong)buf + len);
        else
                invalidate_dcache_range((ulong)buf, (ulong)buf + len);

        writel(virt_to_phys(buf), &regs->dma_addr);

        if (ep->desc->bEndpointAddress & USB_DIR_IN) {
                if (ep->id == 0) {
                        /* Wait until cx/ep0 fifo empty */
                        fotg210_cxwait(chip, CXFIFO_CXFIFOE);
                        udelay(1);
                        writel(DMAFIFO_CX, &regs->dma_fifo);
                } else {
                        /* Wait until epx fifo empty */
                        fotg210_cxwait(chip, CXFIFO_FIFOE(fifo));
                        writel(DMAFIFO_FIFO(fifo), &regs->dma_fifo);
                }
                writel(DMACTRL_LEN(len) | DMACTRL_MEM2FIFO, &regs->dma_ctrl);
        } else {
                uint32_t blen;

                if (ep->id == 0) {
                        writel(DMAFIFO_CX, &regs->dma_fifo);
                        do {
                                blen = CXFIFO_BYTES(readl(&regs->cxfifo));
                        } while (blen < len);
                } else {
                        writel(DMAFIFO_FIFO(fifo), &regs->dma_fifo);
                        blen = FIFOCSR_BYTES(readl(&regs->fifocsr[fifo]));
                }
                len  = (len < blen) ? len : blen;
                writel(DMACTRL_LEN(len) | DMACTRL_FIFO2MEM, &regs->dma_ctrl);
        }

        /* 4. DMA start */
        setbits_le32(&regs->dma_ctrl, DMACTRL_START);

        /* 5. DMA wait */
        ret = -EBUSY;
        for (ts = get_timer(0); get_timer(ts) < CFG_CMD_TIMEOUT; ) {
                tmp = readl(&regs->gisr2);
                /* DMA complete */
                if (tmp & GISR2_DMAFIN) {
                        ret = 0;
                        break;
                }
                /* DMA error */
                if (tmp & GISR2_DMAERR) {
                        printf("fotg210: dma error\n");
                        break;
                }
                /* resume, suspend, reset */
                if (tmp & (GISR2_RESUME | GISR2_SUSPEND | GISR2_RESET)) {
                        printf("fotg210: dma reset by host\n");
                        break;
                }
        }

        /* 7. DMA target reset */
        if (ret)
                writel(DMACTRL_ABORT | DMACTRL_CLRFF, &regs->dma_ctrl);

        writel(0, &regs->gisr2);
        writel(0, &regs->dma_fifo);

        req->req.status = ret;
        if (!ret)
                req->req.actual += len;
        else
                printf("fotg210: ep%d dma error(code=%d)\n", ep->id, ret);

        return len;
}

/*
 * result of setup packet
 */
#define CX_IDLE         0
#define CX_FINISH       1
#define CX_STALL        2

static void fotg210_setup(struct fotg210_chip *chip)
{
        int id, ret = CX_IDLE;
        uint32_t tmp[2];
        struct usb_ctrlrequest *req = (struct usb_ctrlrequest *)tmp;
        struct fotg210_regs *regs = chip->regs;

        /*
         * If this is the first Cx 8 byte command,
         * we can now query USB mode (high/full speed; USB 2.0/USB 1.0)
         */
        if (chip->state == USB_STATE_POWERED) {
                chip->state = USB_STATE_DEFAULT;
                if (readl(&regs->otgcsr) & OTGCSR_DEV_B) {
                        /* Mini-B */
                        if (readl(&regs->dev_ctrl) & DEVCTRL_HS) {
                                puts("fotg210: HS\n");
                                chip->gadget.speed = USB_SPEED_HIGH;
                                /* SOF mask timer = 1100 ticks */
                                writel(SOFMTR_TMR(1100), &regs->sof_mtr);
                        } else {
                                puts("fotg210: FS\n");
                                chip->gadget.speed = USB_SPEED_FULL;
                                /* SOF mask timer = 10000 ticks */
                                writel(SOFMTR_TMR(10000), &regs->sof_mtr);
                        }
                } else {
                        printf("fotg210: mini-A?\n");
                }
        }

        /* switch data port to ep0 */
        writel(DMAFIFO_CX, &regs->dma_fifo);
        /* fetch 8 bytes setup packet */
        tmp[0] = readl(&regs->ep0_data);
        tmp[1] = readl(&regs->ep0_data);
        /* release data port */
        writel(0, &regs->dma_fifo);

        if (req->bRequestType & USB_DIR_IN)
                ep0_desc.bEndpointAddress = USB_DIR_IN;
        else
                ep0_desc.bEndpointAddress = USB_DIR_OUT;

        ret = CX_IDLE;

        if ((req->bRequestType & USB_TYPE_MASK) == USB_TYPE_STANDARD) {
                switch (req->bRequest) {
                case USB_REQ_SET_CONFIGURATION:
                        debug("fotg210: set_cfg(%d)\n", req->wValue & 0x00FF);
                        if (!(req->wValue & 0x00FF)) {
                                chip->state = USB_STATE_ADDRESS;
                                writel(chip->addr, &regs->dev_addr);
                        } else {
                                chip->state = USB_STATE_CONFIGURED;
                                writel(chip->addr | DEVADDR_CONF,
                                        &regs->dev_addr);
                        }
                        ret = CX_IDLE;
                        break;

                case USB_REQ_SET_ADDRESS:
                        debug("fotg210: set_addr(0x%04X)\n", req->wValue);
                        chip->state = USB_STATE_ADDRESS;
                        chip->addr  = req->wValue & DEVADDR_ADDR_MASK;
                        ret = CX_FINISH;
                        writel(chip->addr, &regs->dev_addr);
                        break;

                case USB_REQ_CLEAR_FEATURE:
                        debug("fotg210: clr_feature(%d, %d)\n",
                                req->bRequestType & 0x03, req->wValue);
                        switch (req->wValue) {
                        case 0:    /* [Endpoint] halt */
                                ep_reset(chip, req->wIndex);
                                ret = CX_FINISH;
                                break;
                        case 1:    /* [Device] remote wake-up */
                        case 2:    /* [Device] test mode */
                        default:
                                ret = CX_STALL;
                                break;
                        }
                        break;

                case USB_REQ_SET_FEATURE:
                        debug("fotg210: set_feature(%d, %d)\n",
                                req->wValue, req->wIndex & 0xf);
                        switch (req->wValue) {
                        case 0:    /* Endpoint Halt */
                                id = req->wIndex & 0xf;
                                setbits_le32(&regs->iep[id - 1], IEP_STALL);
                                setbits_le32(&regs->oep[id - 1], OEP_STALL);
                                ret = CX_FINISH;
                                break;
                        case 1:    /* Remote Wakeup */
                        case 2:    /* Test Mode */
                        default:
                                ret = CX_STALL;
                                break;
                        }
                        break;

                case USB_REQ_GET_STATUS:
                        debug("fotg210: get_status\n");
                        ret = CX_STALL;
                        break;

                case USB_REQ_SET_DESCRIPTOR:
                        debug("fotg210: set_descriptor\n");
                        ret = CX_STALL;
                        break;

                case USB_REQ_SYNCH_FRAME:
                        debug("fotg210: sync frame\n");
                        ret = CX_STALL;
                        break;
                }
        } /* if ((req->bRequestType & USB_TYPE_MASK) == USB_TYPE_STANDARD) */

        if (ret == CX_IDLE && chip->driver->setup) {
                if (chip->driver->setup(&chip->gadget, req) < 0)
                        ret = CX_STALL;
                else
                        ret = CX_FINISH;
        }

        switch (ret) {
        case CX_FINISH:
                setbits_le32(&regs->cxfifo, CXFIFO_CXFIN);
                break;

        case CX_STALL:
                setbits_le32(&regs->cxfifo, CXFIFO_CXSTALL | CXFIFO_CXFIN);
                printf("fotg210: cx_stall!\n");
                break;

        case CX_IDLE:
                debug("fotg210: cx_idle?\n");
        default:
                break;
        }
}

/*
 * fifo - FIFO id
 * zlp  - zero length packet
 */
static void fotg210_recv(struct fotg210_chip *chip, int ep_id)
{
        struct fotg210_regs *regs = chip->regs;
        struct fotg210_ep *ep = chip->ep + ep_id;
        struct fotg210_request *req;
        int len;

        if (ep->stopped || (ep->desc->bEndpointAddress & USB_DIR_IN)) {
                printf("fotg210: ep%d recv, invalid!\n", ep->id);
                return;
        }

        if (list_empty(&ep->queue)) {
                printf("fotg210: ep%d recv, drop!\n", ep->id);
                return;
        }

        req = list_first_entry(&ep->queue, struct fotg210_request, queue);
        len = fotg210_dma(ep, req);
        if (len < ep->ep.maxpacket || req->req.length <= req->req.actual) {
                list_del_init(&req->queue);
                if (req->req.complete)
                        req->req.complete(&ep->ep, &req->req);
        }

        if (ep->id > 0 && list_empty(&ep->queue)) {
                setbits_le32(&regs->gimr1,
                        GIMR1_FIFO_RX(ep_to_fifo(chip, ep->id)));
        }
}

/*
 * USB Gadget Layer
 */
static int fotg210_ep_enable(
        struct usb_ep *_ep, const struct usb_endpoint_descriptor *desc)
{
        struct fotg210_ep *ep = container_of(_ep, struct fotg210_ep, ep);
        struct fotg210_chip *chip = ep->chip;
        struct fotg210_regs *regs = chip->regs;
        int id = ep_to_fifo(chip, ep->id);
        int in = (desc->bEndpointAddress & USB_DIR_IN) ? 1 : 0;

        if (!_ep || !desc
                || desc->bDescriptorType != USB_DT_ENDPOINT
                || le16_to_cpu(desc->wMaxPacketSize) == 0) {
                printf("fotg210: bad ep or descriptor\n");
                return -EINVAL;
        }

        ep->desc = desc;
        ep->stopped = 0;

        if (in)
                setbits_le32(&regs->fifomap, FIFOMAP(id, FIFOMAP_IN));

        switch (desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) {
        case USB_ENDPOINT_XFER_CONTROL:
                return -EINVAL;

        case USB_ENDPOINT_XFER_ISOC:
                setbits_le32(&regs->fifocfg,
                        FIFOCFG(id, FIFOCFG_EN | FIFOCFG_ISOC));
                break;

        case USB_ENDPOINT_XFER_BULK:
                setbits_le32(&regs->fifocfg,
                        FIFOCFG(id, FIFOCFG_EN | FIFOCFG_BULK));
                break;

        case USB_ENDPOINT_XFER_INT:
                setbits_le32(&regs->fifocfg,
                        FIFOCFG(id, FIFOCFG_EN | FIFOCFG_INTR));
                break;
        }

        return 0;
}

static int fotg210_ep_disable(struct usb_ep *_ep)
{
        struct fotg210_ep *ep = container_of(_ep, struct fotg210_ep, ep);
        struct fotg210_chip *chip = ep->chip;
        struct fotg210_regs *regs = chip->regs;
        int id = ep_to_fifo(chip, ep->id);

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

        clrbits_le32(&regs->fifocfg, FIFOCFG(id, FIFOCFG_CFG_MASK));
        clrbits_le32(&regs->fifomap, FIFOMAP(id, FIFOMAP_DIR_MASK));

        return 0;
}

static struct usb_request *fotg210_ep_alloc_request(
        struct usb_ep *_ep, gfp_t gfp_flags)
{
        struct fotg210_request *req = malloc(sizeof(*req));

        if (req) {
                memset(req, 0, sizeof(*req));
                INIT_LIST_HEAD(&req->queue);
        }
        return &req->req;
}

static void fotg210_ep_free_request(
        struct usb_ep *_ep, struct usb_request *_req)
{
        struct fotg210_request *req;

        req = container_of(_req, struct fotg210_request, req);
        free(req);
}

static int fotg210_ep_queue(
        struct usb_ep *_ep, struct usb_request *_req, gfp_t gfp_flags)
{
        struct fotg210_ep *ep = container_of(_ep, struct fotg210_ep, ep);
        struct fotg210_chip *chip = ep->chip;
        struct fotg210_regs *regs = chip->regs;
        struct fotg210_request *req;

        req = container_of(_req, struct fotg210_request, req);
        if (!_req || !_req->complete || !_req->buf
                || !list_empty(&req->queue)) {
                printf("fotg210: invalid request to ep%d\n", ep->id);
                return -EINVAL;
        }

        if (!chip || chip->state == USB_STATE_SUSPENDED) {
                printf("fotg210: request while chip suspended\n");
                return -EINVAL;
        }

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

        if (req->req.length == 0) {
                req->req.status = 0;
                if (req->req.complete)
                        req->req.complete(&ep->ep, &req->req);
                return 0;
        }

        if (ep->id == 0) {
                do {
                        int len = fotg210_dma(ep, req);
                        if (len < ep->ep.maxpacket)
                                break;
                        if (ep->desc->bEndpointAddress & USB_DIR_IN)
                                udelay(100);
                } while (req->req.length > req->req.actual);
        } else {
                if (ep->desc->bEndpointAddress & USB_DIR_IN) {
                        do {
                                int len = fotg210_dma(ep, req);
                                if (len < ep->ep.maxpacket)
                                        break;
                        } while (req->req.length > req->req.actual);
                } else {
                        list_add_tail(&req->queue, &ep->queue);
                        clrbits_le32(&regs->gimr1,
                                GIMR1_FIFO_RX(ep_to_fifo(chip, ep->id)));
                }
        }

        if (ep->id == 0 || (ep->desc->bEndpointAddress & USB_DIR_IN)) {
                if (req->req.complete)
                        req->req.complete(&ep->ep, &req->req);
        }

        return 0;
}

static int fotg210_ep_dequeue(struct usb_ep *_ep, struct usb_request *_req)
{
        struct fotg210_ep *ep = container_of(_ep, struct fotg210_ep, ep);
        struct fotg210_request *req;

        /* 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)
                return -EINVAL;

        /* remove the request */
        list_del_init(&req->queue);

        /* update status & invoke complete callback */
        if (req->req.status == -EINPROGRESS) {
                req->req.status = -ECONNRESET;
                if (req->req.complete)
                        req->req.complete(_ep, &req->req);
        }

        return 0;
}

static int fotg210_ep_halt(struct usb_ep *_ep, int halt)
{
        struct fotg210_ep *ep = container_of(_ep, struct fotg210_ep, ep);
        struct fotg210_chip *chip = ep->chip;
        struct fotg210_regs *regs = chip->regs;
        int ret = -1;

        debug("fotg210: ep%d halt=%d\n", ep->id, halt);

        /* Endpoint STALL */
        if (ep->id > 0 && ep->id <= CFG_NUM_ENDPOINTS) {
                if (halt) {
                        /* wait until all ep fifo empty */
                        fotg210_cxwait(chip, 0xf00);
                        /* stall */
                        if (ep->desc->bEndpointAddress & USB_DIR_IN) {
                                setbits_le32(&regs->iep[ep->id - 1],
                                        IEP_STALL);
                        } else {
                                setbits_le32(&regs->oep[ep->id - 1],
                                        OEP_STALL);
                        }
                } else {
                        if (ep->desc->bEndpointAddress & USB_DIR_IN) {
                                clrbits_le32(&regs->iep[ep->id - 1],
                                        IEP_STALL);
                        } else {
                                clrbits_le32(&regs->oep[ep->id - 1],
                                        OEP_STALL);
                        }
                }
                ret = 0;
        }

        return ret;
}

/*
 * activate/deactivate link with host.
 */
static void pullup(struct fotg210_chip *chip, int is_on)
{
        struct fotg210_regs *regs = chip->regs;

        if (is_on) {
                if (!chip->pullup) {
                        chip->state = USB_STATE_POWERED;
                        chip->pullup = 1;
                        /* enable the chip */
                        setbits_le32(&regs->dev_ctrl, DEVCTRL_EN);
                        /* clear unplug bit (BIT0) */
                        clrbits_le32(&regs->phy_tmsr, PHYTMSR_UNPLUG);
                }
        } else {
                chip->state = USB_STATE_NOTATTACHED;
                chip->pullup = 0;
                chip->addr = 0;
                writel(chip->addr, &regs->dev_addr);
                /* set unplug bit (BIT0) */
                setbits_le32(&regs->phy_tmsr, PHYTMSR_UNPLUG);
                /* disable the chip */
                clrbits_le32(&regs->dev_ctrl, DEVCTRL_EN);
        }
}

static int fotg210_pullup(struct usb_gadget *_gadget, int is_on)
{
        struct fotg210_chip *chip;

        chip = container_of(_gadget, struct fotg210_chip, gadget);

        debug("fotg210: pullup=%d\n", is_on);

        pullup(chip, is_on);

        return 0;
}

static int fotg210_get_frame(struct usb_gadget *_gadget)
{
        struct fotg210_chip *chip;
        struct fotg210_regs *regs;

        chip = container_of(_gadget, struct fotg210_chip, gadget);
        regs = chip->regs;

        return SOFFNR_FNR(readl(&regs->sof_fnr));
}

static struct usb_gadget_ops fotg210_gadget_ops = {
        .get_frame = fotg210_get_frame,
        .pullup = fotg210_pullup,
};

static struct usb_ep_ops fotg210_ep_ops = {
        .enable         = fotg210_ep_enable,
        .disable        = fotg210_ep_disable,
        .queue          = fotg210_ep_queue,
        .dequeue        = fotg210_ep_dequeue,
        .set_halt       = fotg210_ep_halt,
        .alloc_request  = fotg210_ep_alloc_request,
        .free_request   = fotg210_ep_free_request,
};

static struct fotg210_chip controller = {
        .regs = (void __iomem *)CONFIG_FOTG210_BASE,
        .gadget = {
                .name = "fotg210_udc",
                .ops = &fotg210_gadget_ops,
                .ep0 = &controller.ep[0].ep,
                .speed = USB_SPEED_UNKNOWN,
                .is_dualspeed = 1,
                .is_otg = 0,
                .is_a_peripheral = 0,
                .b_hnp_enable = 0,
                .a_hnp_support = 0,
                .a_alt_hnp_support = 0,
        },
        .ep[0] = {
                .id = 0,
                .ep = {
                        .name  = "ep0",
                        .ops   = &fotg210_ep_ops,
                },
                .desc      = &ep0_desc,
                .chip      = &controller,
                .maxpacket = CFG_EP0_MAX_PACKET_SIZE,
        },
        .ep[1] = {
                .id = 1,
                .ep = {
                        .name  = "ep1",
                        .ops   = &fotg210_ep_ops,
                },
                .chip      = &controller,
                .maxpacket = CFG_EPX_MAX_PACKET_SIZE,
        },
        .ep[2] = {
                .id = 2,
                .ep = {
                        .name  = "ep2",
                        .ops   = &fotg210_ep_ops,
                },
                .chip      = &controller,
                .maxpacket = CFG_EPX_MAX_PACKET_SIZE,
        },
        .ep[3] = {
                .id = 3,
                .ep = {
                        .name  = "ep3",
                        .ops   = &fotg210_ep_ops,
                },
                .chip      = &controller,
                .maxpacket = CFG_EPX_MAX_PACKET_SIZE,
        },
        .ep[4] = {
                .id = 4,
                .ep = {
                        .name  = "ep4",
                        .ops   = &fotg210_ep_ops,
                },
                .chip      = &controller,
                .maxpacket = CFG_EPX_MAX_PACKET_SIZE,
        },
};

int usb_gadget_handle_interrupts(int index)
{
        struct fotg210_chip *chip = &controller;
        struct fotg210_regs *regs = chip->regs;
        uint32_t id, st, isr, gisr;

        isr  = readl(&regs->isr) & (~readl(&regs->imr));
        gisr = readl(&regs->gisr) & (~readl(&regs->gimr));
        if (!(isr & ISR_DEV) || !gisr)
                return 0;

        writel(ISR_DEV, &regs->isr);

        /* CX interrupts */
        if (gisr & GISR_GRP0) {
                st = readl(&regs->gisr0);
                /*
                 * Write 1 and then 0 works for both W1C & RW.
                 *
                 * HW v1.11.0+: It's a W1C register (write 1 clear)
                 * HW v1.10.0-: It's a R/W register (write 0 clear)
                 */
                writel(st & GISR0_CXABORT, &regs->gisr0);
                writel(0, &regs->gisr0);

                if (st & GISR0_CXERR)
                        printf("fotg210: cmd error\n");

                if (st & GISR0_CXABORT)
                        printf("fotg210: cmd abort\n");

                if (st & GISR0_CXSETUP)    /* setup */
                        fotg210_setup(chip);
                else if (st & GISR0_CXEND) /* command finish */
                        setbits_le32(&regs->cxfifo, CXFIFO_CXFIN);
        }

        /* FIFO interrupts */
        if (gisr & GISR_GRP1) {
                st = readl(&regs->gisr1);
                for (id = 0; id < 4; ++id) {
                        if (st & GISR1_RX_FIFO(id))
                                fotg210_recv(chip, fifo_to_ep(chip, id, 0));
                }
        }

        /* Device Status Interrupts */
        if (gisr & GISR_GRP2) {
                st = readl(&regs->gisr2);
                /*
                 * Write 1 and then 0 works for both W1C & RW.
                 *
                 * HW v1.11.0+: It's a W1C register (write 1 clear)
                 * HW v1.10.0-: It's a R/W register (write 0 clear)
                 */
                writel(st, &regs->gisr2);
                writel(0, &regs->gisr2);

                if (st & GISR2_RESET)
                        printf("fotg210: reset by host\n");
                else if (st & GISR2_SUSPEND)
                        printf("fotg210: suspend/removed\n");
                else if (st & GISR2_RESUME)
                        printf("fotg210: resume\n");

                /* Errors */
                if (st & GISR2_ISOCERR)
                        printf("fotg210: iso error\n");
                if (st & GISR2_ISOCABT)
                        printf("fotg210: iso abort\n");
                if (st & GISR2_DMAERR)
                        printf("fotg210: dma error\n");
        }

        return 0;
}

int usb_gadget_register_driver(struct usb_gadget_driver *driver)
{
        int i, ret = 0;
        struct fotg210_chip *chip = &controller;

        if (!driver    || !driver->bind || !driver->setup) {
                puts("fotg210: bad parameter.\n");
                return -EINVAL;
        }

        INIT_LIST_HEAD(&chip->gadget.ep_list);
        for (i = 0; i < CFG_NUM_ENDPOINTS + 1; ++i) {
                struct fotg210_ep *ep = chip->ep + i;

                ep->ep.maxpacket = ep->maxpacket;
                INIT_LIST_HEAD(&ep->queue);

                if (ep->id == 0) {
                        ep->stopped = 0;
                } else {
                        ep->stopped = 1;
                        list_add_tail(&ep->ep.ep_list, &chip->gadget.ep_list);
                }
        }

        if (fotg210_reset(chip)) {
                puts("fotg210: reset failed.\n");
                return -EINVAL;
        }

        ret = driver->bind(&chip->gadget);
        if (ret) {
                debug("fotg210: driver->bind() returned %d\n", ret);
                return ret;
        }
        chip->driver = driver;

        return ret;
}

int usb_gadget_unregister_driver(struct usb_gadget_driver *driver)
{
        struct fotg210_chip *chip = &controller;

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

        pullup(chip, 0);

        return 0;
}