/*
 * Renesas USB driver
 *
 * Copyright (C) 2011 Renesas Solutions Corp.
 * Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */
#include <linux/dma-mapping.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>
#include "common.h"

/*
 *              struct
 */
struct usbhsg_request {
        struct usb_request      req;
        struct usbhs_pkt        pkt;
};

#define EP_NAME_SIZE 8
struct usbhsg_gpriv;
struct usbhsg_uep {
        struct usb_ep            ep;
        struct usbhs_pipe       *pipe;

        char ep_name[EP_NAME_SIZE];

        struct usbhsg_gpriv *gpriv;
};

struct usbhsg_gpriv {
        struct usb_gadget        gadget;
        struct usbhs_mod         mod;
        struct list_head         link;

        struct usbhsg_uep       *uep;
        int                      uep_size;

        struct usb_gadget_driver        *driver;

        u32     status;
#define USBHSG_STATUS_STARTED           (1 << 0)
#define USBHSG_STATUS_REGISTERD         (1 << 1)
#define USBHSG_STATUS_WEDGE             (1 << 2)
};

struct usbhsg_recip_handle {
        char *name;
        int (*device)(struct usbhs_priv *priv, struct usbhsg_uep *uep,
                      struct usb_ctrlrequest *ctrl);
        int (*interface)(struct usbhs_priv *priv, struct usbhsg_uep *uep,
                         struct usb_ctrlrequest *ctrl);
        int (*endpoint)(struct usbhs_priv *priv, struct usbhsg_uep *uep,
                        struct usb_ctrlrequest *ctrl);
};

/*
 *              macro
 */
#define usbhsg_priv_to_gpriv(priv)                      \
        container_of(                                   \
                usbhs_mod_get(priv, USBHS_GADGET),      \
                struct usbhsg_gpriv, mod)

#define __usbhsg_for_each_uep(start, pos, g, i) \
        for (i = start, pos = (g)->uep + i;     \
             i < (g)->uep_size;                 \
             i++, pos = (g)->uep + i)

#define usbhsg_for_each_uep(pos, gpriv, i)      \
        __usbhsg_for_each_uep(1, pos, gpriv, i)

#define usbhsg_for_each_uep_with_dcp(pos, gpriv, i)     \
        __usbhsg_for_each_uep(0, pos, gpriv, i)

#define usbhsg_gadget_to_gpriv(g)\
        container_of(g, struct usbhsg_gpriv, gadget)

#define usbhsg_req_to_ureq(r)\
        container_of(r, struct usbhsg_request, req)

#define usbhsg_ep_to_uep(e)             container_of(e, struct usbhsg_uep, ep)
#define usbhsg_gpriv_to_dev(gp)         usbhs_priv_to_dev((gp)->mod.priv)
#define usbhsg_gpriv_to_priv(gp)        ((gp)->mod.priv)
#define usbhsg_gpriv_to_dcp(gp)         ((gp)->uep)
#define usbhsg_gpriv_to_nth_uep(gp, i)  ((gp)->uep + i)
#define usbhsg_uep_to_gpriv(u)          ((u)->gpriv)
#define usbhsg_uep_to_pipe(u)           ((u)->pipe)
#define usbhsg_pipe_to_uep(p)           ((p)->mod_private)
#define usbhsg_is_dcp(u)                ((u) == usbhsg_gpriv_to_dcp((u)->gpriv))

#define usbhsg_ureq_to_pkt(u)           (&(u)->pkt)
#define usbhsg_pkt_to_ureq(i)   \
        container_of(i, struct usbhsg_request, pkt)

#define usbhsg_is_not_connected(gp) ((gp)->gadget.speed == USB_SPEED_UNKNOWN)

/* status */
#define usbhsg_status_init(gp)   do {(gp)->status = 0; } while (0)
#define usbhsg_status_set(gp, b) (gp->status |=  b)
#define usbhsg_status_clr(gp, b) (gp->status &= ~b)
#define usbhsg_status_has(gp, b) (gp->status &   b)

/* controller */
LIST_HEAD(the_controller_link);

#define usbhsg_for_each_controller(gpriv)\
        list_for_each_entry(gpriv, &the_controller_link, link)
#define usbhsg_controller_register(gpriv)\
        list_add_tail(&(gpriv)->link, &the_controller_link)
#define usbhsg_controller_unregister(gpriv)\
        list_del_init(&(gpriv)->link)

/*
 *              queue push/pop
 */
static void usbhsg_queue_pop(struct usbhsg_uep *uep,
                             struct usbhsg_request *ureq,
                             int status)
{
        struct usbhsg_gpriv *gpriv = usbhsg_uep_to_gpriv(uep);
        struct usbhs_pipe *pipe = usbhsg_uep_to_pipe(uep);
        struct device *dev = usbhsg_gpriv_to_dev(gpriv);

        dev_dbg(dev, "pipe %d : queue pop\n", usbhs_pipe_number(pipe));

        ureq->req.status = status;
        ureq->req.complete(&uep->ep, &ureq->req);
}

static void usbhsg_queue_done(struct usbhs_priv *priv, struct usbhs_pkt *pkt)
{
        struct usbhs_pipe *pipe = pkt->pipe;
        struct usbhsg_uep *uep = usbhsg_pipe_to_uep(pipe);
        struct usbhsg_request *ureq = usbhsg_pkt_to_ureq(pkt);

        ureq->req.actual = pkt->actual;

        usbhsg_queue_pop(uep, ureq, 0);
}

static void usbhsg_queue_push(struct usbhsg_uep *uep,
                              struct usbhsg_request *ureq)
{
        struct usbhsg_gpriv *gpriv = usbhsg_uep_to_gpriv(uep);
        struct device *dev = usbhsg_gpriv_to_dev(gpriv);
        struct usbhs_pipe *pipe = usbhsg_uep_to_pipe(uep);
        struct usbhs_pkt *pkt = usbhsg_ureq_to_pkt(ureq);
        struct usb_request *req = &ureq->req;

        req->actual = 0;
        req->status = -EINPROGRESS;
        usbhs_pkt_push(pipe, pkt, usbhsg_queue_done,
                       req->buf, req->length, req->zero);
        usbhs_pkt_start(pipe);

        dev_dbg(dev, "pipe %d : queue push (%d)\n",
                usbhs_pipe_number(pipe),
                req->length);
}

/*
 *              dma map/unmap
 */
static int usbhsg_dma_map(struct device *dev,
                          struct usbhs_pkt *pkt,
                          enum dma_data_direction dir)
{
        struct usbhsg_request *ureq = usbhsg_pkt_to_ureq(pkt);
        struct usb_request *req = &ureq->req;

        if (pkt->dma != DMA_ADDR_INVALID) {
                dev_err(dev, "dma is already mapped\n");
                return -EIO;
        }

        if (req->dma == DMA_ADDR_INVALID) {
                pkt->dma = dma_map_single(dev, pkt->buf, pkt->length, dir);
        } else {
                dma_sync_single_for_device(dev, req->dma, req->length, dir);
                pkt->dma = req->dma;
        }

        if (dma_mapping_error(dev, pkt->dma)) {
                dev_err(dev, "dma mapping error %x\n", pkt->dma);
                return -EIO;
        }

        return 0;
}

static int usbhsg_dma_unmap(struct device *dev,
                            struct usbhs_pkt *pkt,
                            enum dma_data_direction dir)
{
        struct usbhsg_request *ureq = usbhsg_pkt_to_ureq(pkt);
        struct usb_request *req = &ureq->req;

        if (pkt->dma == DMA_ADDR_INVALID) {
                dev_err(dev, "dma is not mapped\n");
                return -EIO;
        }

        if (req->dma == DMA_ADDR_INVALID)
                dma_unmap_single(dev, pkt->dma, pkt->length, dir);
        else
                dma_sync_single_for_cpu(dev, req->dma, req->length, dir);

        pkt->dma = DMA_ADDR_INVALID;

        return 0;
}

static int usbhsg_dma_map_ctrl(struct usbhs_pkt *pkt, int map)
{
        struct usbhs_pipe *pipe = pkt->pipe;
        struct usbhsg_uep *uep = usbhsg_pipe_to_uep(pipe);
        struct usbhsg_gpriv *gpriv = usbhsg_uep_to_gpriv(uep);
        struct device *dev = usbhsg_gpriv_to_dev(gpriv);
        enum dma_data_direction dir;

        dir = usbhs_pipe_is_dir_in(pipe) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;

        if (map)
                return usbhsg_dma_map(dev, pkt, dir);
        else
                return usbhsg_dma_unmap(dev, pkt, dir);
}

/*
 *              USB_TYPE_STANDARD / clear feature functions
 */
static int usbhsg_recip_handler_std_control_done(struct usbhs_priv *priv,
                                                 struct usbhsg_uep *uep,
                                                 struct usb_ctrlrequest *ctrl)
{
        struct usbhsg_gpriv *gpriv = usbhsg_priv_to_gpriv(priv);
        struct usbhsg_uep *dcp = usbhsg_gpriv_to_dcp(gpriv);
        struct usbhs_pipe *pipe = usbhsg_uep_to_pipe(dcp);

        usbhs_dcp_control_transfer_done(pipe);

        return 0;
}

static int usbhsg_recip_handler_std_clear_endpoint(struct usbhs_priv *priv,
                                                   struct usbhsg_uep *uep,
                                                   struct usb_ctrlrequest *ctrl)
{
        struct usbhsg_gpriv *gpriv = usbhsg_uep_to_gpriv(uep);
        struct usbhs_pipe *pipe = usbhsg_uep_to_pipe(uep);

        if (!usbhsg_status_has(gpriv, USBHSG_STATUS_WEDGE)) {
                usbhs_pipe_disable(pipe);
                usbhs_pipe_sequence_data0(pipe);
                usbhs_pipe_enable(pipe);
        }

        usbhsg_recip_handler_std_control_done(priv, uep, ctrl);

        return 0;
}

struct usbhsg_recip_handle req_clear_feature = {
        .name           = "clear feature",
        .device         = usbhsg_recip_handler_std_control_done,
        .interface      = usbhsg_recip_handler_std_control_done,
        .endpoint       = usbhsg_recip_handler_std_clear_endpoint,
};

/*
 *              USB_TYPE handler
 */
static int usbhsg_recip_run_handle(struct usbhs_priv *priv,
                                   struct usbhsg_recip_handle *handler,
                                   struct usb_ctrlrequest *ctrl)
{
        struct usbhsg_gpriv *gpriv = usbhsg_priv_to_gpriv(priv);
        struct device *dev = usbhsg_gpriv_to_dev(gpriv);
        struct usbhsg_uep *uep;
        struct usbhs_pipe *pipe;
        int recip = ctrl->bRequestType & USB_RECIP_MASK;
        int nth = le16_to_cpu(ctrl->wIndex) & USB_ENDPOINT_NUMBER_MASK;
        int ret;
        int (*func)(struct usbhs_priv *priv, struct usbhsg_uep *uep,
                    struct usb_ctrlrequest *ctrl);
        char *msg;

        uep = usbhsg_gpriv_to_nth_uep(gpriv, nth);
        pipe = usbhsg_uep_to_pipe(uep);
        if (!pipe) {
                dev_err(dev, "wrong recip request\n");
                ret = -EINVAL;
                goto usbhsg_recip_run_handle_end;
        }

        switch (recip) {
        case USB_RECIP_DEVICE:
                msg     = "DEVICE";
                func    = handler->device;
                break;
        case USB_RECIP_INTERFACE:
                msg     = "INTERFACE";
                func    = handler->interface;
                break;
        case USB_RECIP_ENDPOINT:
                msg     = "ENDPOINT";
                func    = handler->endpoint;
                break;
        default:
                dev_warn(dev, "unsupported RECIP(%d)\n", recip);
                func = NULL;
                ret = -EINVAL;
        }

        if (func) {
                unsigned long flags;

                dev_dbg(dev, "%s (pipe %d :%s)\n", handler->name, nth, msg);

                /********************  spin lock ********************/
                usbhs_lock(priv, flags);
                ret = func(priv, uep, ctrl);
                usbhs_unlock(priv, flags);
                /********************  spin unlock ******************/
        }

usbhsg_recip_run_handle_end:
        usbhs_pkt_start(pipe);

        return ret;
}

/*
 *              irq functions
 *
 * it will be called from usbhs_interrupt
 */
static int usbhsg_irq_dev_state(struct usbhs_priv *priv,
                                struct usbhs_irq_state *irq_state)
{
        struct usbhsg_gpriv *gpriv = usbhsg_priv_to_gpriv(priv);
        struct device *dev = usbhsg_gpriv_to_dev(gpriv);

        gpriv->gadget.speed = usbhs_bus_get_speed(priv);

        dev_dbg(dev, "state = %x : speed : %d\n",
                usbhs_status_get_device_state(irq_state),
                gpriv->gadget.speed);

        return 0;
}

static int usbhsg_irq_ctrl_stage(struct usbhs_priv *priv,
                                 struct usbhs_irq_state *irq_state)
{
        struct usbhsg_gpriv *gpriv = usbhsg_priv_to_gpriv(priv);
        struct usbhsg_uep *dcp = usbhsg_gpriv_to_dcp(gpriv);
        struct usbhs_pipe *pipe = usbhsg_uep_to_pipe(dcp);
        struct device *dev = usbhsg_gpriv_to_dev(gpriv);
        struct usb_ctrlrequest ctrl;
        struct usbhsg_recip_handle *recip_handler = NULL;
        int stage = usbhs_status_get_ctrl_stage(irq_state);
        int ret = 0;

        dev_dbg(dev, "stage = %d\n", stage);

        /*
         * see Manual
         *
         *  "Operation"
         *  - "Interrupt Function"
         *    - "Control Transfer Stage Transition Interrupt"
         *      - Fig. "Control Transfer Stage Transitions"
         */

        switch (stage) {
        case READ_DATA_STAGE:
                pipe->handler = &usbhs_fifo_pio_push_handler;
                break;
        case WRITE_DATA_STAGE:
                pipe->handler = &usbhs_fifo_pio_pop_handler;
                break;
        case NODATA_STATUS_STAGE:
                pipe->handler = &usbhs_ctrl_stage_end_handler;
                break;
        default:
                return ret;
        }

        /*
         * get usb request
         */
        usbhs_usbreq_get_val(priv, &ctrl);

        switch (ctrl.bRequestType & USB_TYPE_MASK) {
        case USB_TYPE_STANDARD:
                switch (ctrl.bRequest) {
                case USB_REQ_CLEAR_FEATURE:
                        recip_handler = &req_clear_feature;
                        break;
                }
        }

        /*
         * setup stage / run recip
         */
        if (recip_handler)
                ret = usbhsg_recip_run_handle(priv, recip_handler, &ctrl);
        else
                ret = gpriv->driver->setup(&gpriv->gadget, &ctrl);

        if (ret < 0)
                usbhs_pipe_stall(pipe);

        return ret;
}

/*
 *
 *              usb_dcp_ops
 *
 */
static int usbhsg_pipe_disable(struct usbhsg_uep *uep)
{
        struct usbhs_pipe *pipe = usbhsg_uep_to_pipe(uep);
        struct usbhs_pkt *pkt;

        usbhs_pipe_disable(pipe);

        while (1) {
                pkt = usbhs_pkt_pop(pipe, NULL);
                if (!pkt)
                        break;
        }

        return 0;
}

static void usbhsg_uep_init(struct usbhsg_gpriv *gpriv)
{
        int i;
        struct usbhsg_uep *uep;

        usbhsg_for_each_uep_with_dcp(uep, gpriv, i)
                uep->pipe = NULL;
}

/*
 *
 *              usb_ep_ops
 *
 */
static int usbhsg_ep_enable(struct usb_ep *ep,
                         const struct usb_endpoint_descriptor *desc)
{
        struct usbhsg_uep *uep   = usbhsg_ep_to_uep(ep);
        struct usbhsg_gpriv *gpriv = usbhsg_uep_to_gpriv(uep);
        struct usbhs_priv *priv = usbhsg_gpriv_to_priv(gpriv);
        struct usbhs_pipe *pipe;
        int ret = -EIO;

        /*
         * if it already have pipe,
         * nothing to do
         */
        if (uep->pipe) {
                usbhs_pipe_clear(uep->pipe);
                usbhs_pipe_sequence_data0(uep->pipe);
                return 0;
        }

        pipe = usbhs_pipe_malloc(priv,
                                 usb_endpoint_type(desc),
                                 usb_endpoint_dir_in(desc));
        if (pipe) {
                uep->pipe               = pipe;
                pipe->mod_private       = uep;

                /* set epnum / maxp */
                usbhs_pipe_config_update(pipe, 0,
                                         usb_endpoint_num(desc),
                                         usb_endpoint_maxp(desc));

                /*
                 * usbhs_fifo_dma_push/pop_handler try to
                 * use dmaengine if possible.
                 * It will use pio handler if impossible.
                 */
                if (usb_endpoint_dir_in(desc))
                        pipe->handler = &usbhs_fifo_dma_push_handler;
                else
                        pipe->handler = &usbhs_fifo_dma_pop_handler;

                ret = 0;
        }

        return ret;
}

static int usbhsg_ep_disable(struct usb_ep *ep)
{
        struct usbhsg_uep *uep = usbhsg_ep_to_uep(ep);

        return usbhsg_pipe_disable(uep);
}

static struct usb_request *usbhsg_ep_alloc_request(struct usb_ep *ep,
                                                   gfp_t gfp_flags)
{
        struct usbhsg_request *ureq;

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

        usbhs_pkt_init(usbhsg_ureq_to_pkt(ureq));

        ureq->req.dma = DMA_ADDR_INVALID;

        return &ureq->req;
}

static void usbhsg_ep_free_request(struct usb_ep *ep,
                                   struct usb_request *req)
{
        struct usbhsg_request *ureq = usbhsg_req_to_ureq(req);

        WARN_ON(!list_empty(&ureq->pkt.node));
        kfree(ureq);
}

static int usbhsg_ep_queue(struct usb_ep *ep, struct usb_request *req,
                          gfp_t gfp_flags)
{
        struct usbhsg_uep *uep = usbhsg_ep_to_uep(ep);
        struct usbhsg_gpriv *gpriv = usbhsg_uep_to_gpriv(uep);
        struct usbhsg_request *ureq = usbhsg_req_to_ureq(req);
        struct usbhs_pipe *pipe = usbhsg_uep_to_pipe(uep);

        /* param check */
        if (usbhsg_is_not_connected(gpriv)      ||
            unlikely(!gpriv->driver)            ||
            unlikely(!pipe))
                return -ESHUTDOWN;

        usbhsg_queue_push(uep, ureq);

        return 0;
}

static int usbhsg_ep_dequeue(struct usb_ep *ep, struct usb_request *req)
{
        struct usbhsg_uep *uep = usbhsg_ep_to_uep(ep);
        struct usbhsg_request *ureq = usbhsg_req_to_ureq(req);
        struct usbhs_pipe *pipe = usbhsg_uep_to_pipe(uep);

        usbhs_pkt_pop(pipe, usbhsg_ureq_to_pkt(ureq));
        usbhsg_queue_pop(uep, ureq, -ECONNRESET);

        return 0;
}

static int __usbhsg_ep_set_halt_wedge(struct usb_ep *ep, int halt, int wedge)
{
        struct usbhsg_uep *uep = usbhsg_ep_to_uep(ep);
        struct usbhs_pipe *pipe = usbhsg_uep_to_pipe(uep);
        struct usbhsg_gpriv *gpriv = usbhsg_uep_to_gpriv(uep);
        struct usbhs_priv *priv = usbhsg_gpriv_to_priv(gpriv);
        struct device *dev = usbhsg_gpriv_to_dev(gpriv);
        unsigned long flags;

        usbhsg_pipe_disable(uep);

        dev_dbg(dev, "set halt %d (pipe %d)\n",
                halt, usbhs_pipe_number(pipe));

        /********************  spin lock ********************/
        usbhs_lock(priv, flags);

        if (halt)
                usbhs_pipe_stall(pipe);
        else
                usbhs_pipe_disable(pipe);

        if (halt && wedge)
                usbhsg_status_set(gpriv, USBHSG_STATUS_WEDGE);
        else
                usbhsg_status_clr(gpriv, USBHSG_STATUS_WEDGE);

        usbhs_unlock(priv, flags);
        /********************  spin unlock ******************/

        return 0;
}

static int usbhsg_ep_set_halt(struct usb_ep *ep, int value)
{
        return __usbhsg_ep_set_halt_wedge(ep, value, 0);
}

static int usbhsg_ep_set_wedge(struct usb_ep *ep)
{
        return __usbhsg_ep_set_halt_wedge(ep, 1, 1);
}

static struct usb_ep_ops usbhsg_ep_ops = {
        .enable         = usbhsg_ep_enable,
        .disable        = usbhsg_ep_disable,

        .alloc_request  = usbhsg_ep_alloc_request,
        .free_request   = usbhsg_ep_free_request,

        .queue          = usbhsg_ep_queue,
        .dequeue        = usbhsg_ep_dequeue,

        .set_halt       = usbhsg_ep_set_halt,
        .set_wedge      = usbhsg_ep_set_wedge,
};

/*
 *              usb module start/end
 */
static int usbhsg_try_start(struct usbhs_priv *priv, u32 status)
{
        struct usbhsg_gpriv *gpriv = usbhsg_priv_to_gpriv(priv);
        struct usbhsg_uep *dcp = usbhsg_gpriv_to_dcp(gpriv);
        struct usbhs_mod *mod = usbhs_mod_get_current(priv);
        struct device *dev = usbhs_priv_to_dev(priv);
        unsigned long flags;
        int ret = 0;

        /********************  spin lock ********************/
        usbhs_lock(priv, flags);

        usbhsg_status_set(gpriv, status);
        if (!(usbhsg_status_has(gpriv, USBHSG_STATUS_STARTED) &&
              usbhsg_status_has(gpriv, USBHSG_STATUS_REGISTERD)))
                ret = -1; /* not ready */

        usbhs_unlock(priv, flags);
        /********************  spin unlock ********************/

        if (ret < 0)
                return 0; /* not ready is not error */

        /*
         * enable interrupt and systems if ready
         */
        dev_dbg(dev, "start gadget\n");

        /*
         * pipe initialize and enable DCP
         */
        usbhs_pipe_init(priv,
                        usbhsg_dma_map_ctrl);
        usbhs_fifo_init(priv);
        usbhsg_uep_init(gpriv);

        /* dcp init */
        dcp->pipe               = usbhs_dcp_malloc(priv);
        dcp->pipe->mod_private  = dcp;
        usbhs_pipe_config_update(dcp->pipe, 0, 0, 64);

        /*
         * system config enble
         * - HI speed
         * - function
         * - usb module
         */
        usbhs_sys_hispeed_ctrl(priv, 1);
        usbhs_sys_function_ctrl(priv, 1);
        usbhs_sys_usb_ctrl(priv, 1);

        /*
         * enable irq callback
         */
        mod->irq_dev_state      = usbhsg_irq_dev_state;
        mod->irq_ctrl_stage     = usbhsg_irq_ctrl_stage;
        usbhs_irq_callback_update(priv, mod);

        return 0;
}

static int usbhsg_try_stop(struct usbhs_priv *priv, u32 status)
{
        struct usbhsg_gpriv *gpriv = usbhsg_priv_to_gpriv(priv);
        struct usbhs_mod *mod = usbhs_mod_get_current(priv);
        struct usbhsg_uep *dcp = usbhsg_gpriv_to_dcp(gpriv);
        struct device *dev = usbhs_priv_to_dev(priv);
        unsigned long flags;
        int ret = 0;

        /********************  spin lock ********************/
        usbhs_lock(priv, flags);

        usbhsg_status_clr(gpriv, status);
        if (!usbhsg_status_has(gpriv, USBHSG_STATUS_STARTED) &&
            !usbhsg_status_has(gpriv, USBHSG_STATUS_REGISTERD))
                ret = -1; /* already done */

        usbhs_unlock(priv, flags);
        /********************  spin unlock ********************/

        if (ret < 0)
                return 0; /* already done is not error */

        /*
         * disable interrupt and systems if 1st try
         */
        usbhs_fifo_quit(priv);

        /* disable all irq */
        mod->irq_dev_state      = NULL;
        mod->irq_ctrl_stage     = NULL;
        usbhs_irq_callback_update(priv, mod);

        gpriv->gadget.speed = USB_SPEED_UNKNOWN;

        /* disable sys */
        usbhs_sys_hispeed_ctrl(priv, 0);
        usbhs_sys_function_ctrl(priv, 0);
        usbhs_sys_usb_ctrl(priv, 0);

        usbhsg_pipe_disable(dcp);

        dev_dbg(dev, "stop gadget\n");

        return 0;
}

/*
 *
 *              linux usb function
 *
 */
static int usbhsg_gadget_start(struct usb_gadget *gadget,
                struct usb_gadget_driver *driver)
{
        struct usbhsg_gpriv *gpriv = usbhsg_gadget_to_gpriv(gadget);
        struct usbhs_priv *priv = usbhsg_gpriv_to_priv(gpriv);

        if (!driver             ||
            !driver->setup      ||
            driver->speed < USB_SPEED_FULL)
                return -EINVAL;

        /* first hook up the driver ... */
        gpriv->driver = driver;
        gpriv->gadget.dev.driver = &driver->driver;

        return usbhsg_try_start(priv, USBHSG_STATUS_REGISTERD);
}

static int usbhsg_gadget_stop(struct usb_gadget *gadget,
                struct usb_gadget_driver *driver)
{
        struct usbhsg_gpriv *gpriv = usbhsg_gadget_to_gpriv(gadget);
        struct usbhs_priv *priv = usbhsg_gpriv_to_priv(gpriv);

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

        usbhsg_try_stop(priv, USBHSG_STATUS_REGISTERD);
        gpriv->gadget.dev.driver = NULL;
        gpriv->driver = NULL;

        return 0;
}

/*
 *              usb gadget ops
 */
static int usbhsg_get_frame(struct usb_gadget *gadget)
{
        struct usbhsg_gpriv *gpriv = usbhsg_gadget_to_gpriv(gadget);
        struct usbhs_priv *priv = usbhsg_gpriv_to_priv(gpriv);

        return usbhs_frame_get_num(priv);
}

static struct usb_gadget_ops usbhsg_gadget_ops = {
        .get_frame              = usbhsg_get_frame,
        .udc_start              = usbhsg_gadget_start,
        .udc_stop               = usbhsg_gadget_stop,
};

static int usbhsg_start(struct usbhs_priv *priv)
{
        return usbhsg_try_start(priv, USBHSG_STATUS_STARTED);
}

static int usbhsg_stop(struct usbhs_priv *priv)
{
        struct usbhsg_gpriv *gpriv = usbhsg_priv_to_gpriv(priv);

        /* cable disconnect */
        if (gpriv->driver &&
            gpriv->driver->disconnect)
                gpriv->driver->disconnect(&gpriv->gadget);

        return usbhsg_try_stop(priv, USBHSG_STATUS_STARTED);
}

int usbhs_mod_gadget_probe(struct usbhs_priv *priv)
{
        struct usbhsg_gpriv *gpriv;
        struct usbhsg_uep *uep;
        struct device *dev = usbhs_priv_to_dev(priv);
        int pipe_size = usbhs_get_dparam(priv, pipe_size);
        int i;
        int ret;

        gpriv = kzalloc(sizeof(struct usbhsg_gpriv), GFP_KERNEL);
        if (!gpriv) {
                dev_err(dev, "Could not allocate gadget priv\n");
                return -ENOMEM;
        }

        uep = kzalloc(sizeof(struct usbhsg_uep) * pipe_size, GFP_KERNEL);
        if (!uep) {
                dev_err(dev, "Could not allocate ep\n");
                ret = -ENOMEM;
                goto usbhs_mod_gadget_probe_err_gpriv;
        }

        /*
         * CAUTION
         *
         * There is no guarantee that it is possible to access usb module here.
         * Don't accesses to it.
         * The accesse will be enable after "usbhsg_start"
         */

        /*
         * register itself
         */
        usbhs_mod_register(priv, &gpriv->mod, USBHS_GADGET);

        /* init gpriv */
        gpriv->mod.name         = "gadget";
        gpriv->mod.start        = usbhsg_start;
        gpriv->mod.stop         = usbhsg_stop;
        gpriv->uep              = uep;
        gpriv->uep_size         = pipe_size;
        usbhsg_status_init(gpriv);

        /*
         * init gadget
         */
        dev_set_name(&gpriv->gadget.dev, "gadget");
        gpriv->gadget.dev.parent        = dev;
        gpriv->gadget.name              = "renesas_usbhs_udc";
        gpriv->gadget.ops               = &usbhsg_gadget_ops;
        gpriv->gadget.is_dualspeed      = 1;
        ret = device_register(&gpriv->gadget.dev);
        if (ret < 0)
                goto err_add_udc;

        INIT_LIST_HEAD(&gpriv->gadget.ep_list);

        /*
         * init usb_ep
         */
        usbhsg_for_each_uep_with_dcp(uep, gpriv, i) {
                uep->gpriv      = gpriv;
                snprintf(uep->ep_name, EP_NAME_SIZE, "ep%d", i);

                uep->ep.name            = uep->ep_name;
                uep->ep.ops             = &usbhsg_ep_ops;
                INIT_LIST_HEAD(&uep->ep.ep_list);

                /* init DCP */
                if (usbhsg_is_dcp(uep)) {
                        gpriv->gadget.ep0 = &uep->ep;
                        uep->ep.maxpacket = 64;
                }
                /* init normal pipe */
                else {
                        uep->ep.maxpacket = 512;
                        list_add_tail(&uep->ep.ep_list, &gpriv->gadget.ep_list);
                }
        }

        usbhsg_controller_register(gpriv);

        ret = usb_add_gadget_udc(dev, &gpriv->gadget);
        if (ret)
                goto err_register;


        dev_info(dev, "gadget probed\n");

        return 0;

err_register:
        device_unregister(&gpriv->gadget.dev);
err_add_udc:
        kfree(gpriv->uep);

usbhs_mod_gadget_probe_err_gpriv:
        kfree(gpriv);

        return ret;
}

void usbhs_mod_gadget_remove(struct usbhs_priv *priv)
{
        struct usbhsg_gpriv *gpriv = usbhsg_priv_to_gpriv(priv);

        usb_del_gadget_udc(&gpriv->gadget);

        device_unregister(&gpriv->gadget.dev);

        usbhsg_controller_unregister(gpriv);

        kfree(gpriv->uep);
        kfree(gpriv);
}