usb: renesas_usbhs: don't re-allocation pipe buffer

[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / usb / renesas_usbhs / mod_gadget.c

/*
 * 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/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 list_head        node;
};

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

        char ep_name[EP_NAME_SIZE];

        struct usbhsg_gpriv *gpriv;
        struct usbhsg_pipe_handle *handler;
};

struct usbhsg_gpriv {
        struct usb_gadget        gadget;
        struct usbhs_mod         mod;

        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_pipe_handle {
        int (*prepare)(struct usbhsg_uep *uep, struct usbhsg_request *ureq);
        int (*try_run)(struct usbhsg_uep *uep, struct usbhsg_request *ureq);
        void (*irq_mask)(struct usbhsg_uep *uep, int enable);
};

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 < (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_lock(gp)        usbhs_priv_to_lock((gp)->mod.priv)
#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_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)

/*
 *              list push/pop
 */
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);

        /*
         *********  assume under spin lock  *********
         */
        list_del_init(&ureq->node);
        list_add_tail(&ureq->node, &uep->list);
        ureq->req.actual = 0;
        ureq->req.status = -EINPROGRESS;

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

static struct usbhsg_request *usbhsg_queue_get(struct usbhsg_uep *uep)
{
        /*
         *********  assume under spin lock  *********
         */
        if (list_empty(&uep->list))
                return NULL;

        return list_entry(uep->list.next, struct usbhsg_request, node);
}

#define usbhsg_queue_prepare(uep) __usbhsg_queue_handler(uep, 1);
#define usbhsg_queue_handle(uep)  __usbhsg_queue_handler(uep, 0);
static int __usbhsg_queue_handler(struct usbhsg_uep *uep, int prepare)
{
        struct usbhsg_gpriv *gpriv = usbhsg_uep_to_gpriv(uep);
        struct device *dev = usbhsg_gpriv_to_dev(gpriv);
        struct usbhsg_request *ureq;
        spinlock_t *lock = usbhsg_gpriv_to_lock(gpriv);
        unsigned long flags;
        int is_locked;
        int ret = 0;

        if (!uep->handler) {
                dev_err(dev, "no handler function\n");
                return -EIO;
        }

        /*
         * CAUTION [*queue handler*]
         *
         * This function will be called for start/restart queue operation.
         * OTOH the most much worry for USB driver is spinlock nest.
         * Specially it are
         *   - usb_ep_ops  :: queue
         *   - usb_request :: complete
         *
         * But the caller of this function need not care about spinlock.
         * This function is using spin_trylock_irqsave for it.
         * if "is_locked" is 1, this mean this function lock it.
         * but if it is 0, this mean it is already under spin lock.
         * see also
         *   CAUTION [*endpoint queue*]
         *   CAUTION [*request complete*]
         */

        /******************  spin try lock *******************/
        is_locked = spin_trylock_irqsave(lock, flags);
        ureq = usbhsg_queue_get(uep);
        if (ureq) {
                if (prepare)
                        ret = uep->handler->prepare(uep, ureq);
                else
                        ret = uep->handler->try_run(uep, ureq);
        }
        if (is_locked)
                spin_unlock_irqrestore(lock, flags);
        /********************  spin unlock ******************/

        return ret;
}

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);

        /*
         *********  assume under spin lock  *********
         */

        /*
         * CAUTION [*request complete*]
         *
         * There is a possibility not to be called in correct order
         * if "complete" is called without spinlock.
         *
         * So, this function assume it is under spinlock,
         * and call usb_request :: complete.
         *
         * But this "complete" will push next usb_request.
         * It mean "usb_ep_ops :: queue" which is using spinlock is called
         * under spinlock.
         *
         * To avoid dead-lock, this driver is using spin_trylock.
         *   CAUTION [*endpoint queue*]
         *   CAUTION [*queue handler*]
         */

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

        list_del_init(&ureq->node);

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

        /* more request ? */
        if (0 == status)
                usbhsg_queue_prepare(uep);
}

/*
 *              irq enable/disable function
 */
#define usbhsg_irq_callback_ctrl(uep, status, enable)                   \
        ({                                                              \
                struct usbhsg_gpriv *gpriv = usbhsg_uep_to_gpriv(uep);  \
                struct usbhs_pipe *pipe = usbhsg_uep_to_pipe(uep);      \
                struct usbhs_priv *priv = usbhsg_gpriv_to_priv(gpriv);  \
                struct usbhs_mod *mod = usbhs_mod_get_current(priv);    \
                if (!mod)                                               \
                        return;                                         \
                if (enable)                                             \
                        mod->irq_##status |= (1 << usbhs_pipe_number(pipe)); \
                else                                                    \
                        mod->irq_##status &= ~(1 << usbhs_pipe_number(pipe)); \
                usbhs_irq_callback_update(priv, mod);                   \
        })

static void usbhsg_irq_empty_ctrl(struct usbhsg_uep *uep, int enable)
{
        usbhsg_irq_callback_ctrl(uep, bempsts, enable);
}

static void usbhsg_irq_ready_ctrl(struct usbhsg_uep *uep, int enable)
{
        usbhsg_irq_callback_ctrl(uep, brdysts, enable);
}

/*
 *              handler function
 */
static int usbhsg_try_run_ctrl_stage_end(struct usbhsg_uep *uep,
                                         struct usbhsg_request *ureq)
{
        struct usbhs_pipe *pipe = usbhsg_uep_to_pipe(uep);

        /*
         *********  assume under spin lock  *********
         */

        usbhs_dcp_control_transfer_done(pipe);
        usbhsg_queue_pop(uep, ureq, 0);

        return 0;
}

static int usbhsg_try_run_send_packet(struct usbhsg_uep *uep,
                                      struct usbhsg_request *ureq)
{
        struct usbhs_pipe *pipe = usbhsg_uep_to_pipe(uep);
        struct usb_request *req = &ureq->req;
        struct usbhsg_gpriv *gpriv = usbhsg_uep_to_gpriv(uep);
        struct device *dev = usbhsg_gpriv_to_dev(gpriv);
        void *buf;
        int remainder, send;
        int is_done = 0;
        int enable;
        int maxp;

        /*
         *********  assume under spin lock  *********
         */

        maxp            = usbhs_pipe_get_maxpacket(pipe);
        buf             = req->buf    + req->actual;
        remainder       = req->length - req->actual;

        send = usbhs_fifo_write(pipe, buf, remainder);

        /*
         * send < 0 : pipe busy
         * send = 0 : send zero packet
         * send > 0 : send data
         *
         * send <= max_packet
         */
        if (send > 0)
                req->actual += send;

        /* send all packet ? */
        if (send < remainder)
                is_done = 0;            /* there are remainder data */
        else if (send < maxp)
                is_done = 1;            /* short packet */
        else
                is_done = !req->zero;   /* send zero packet ? */

        dev_dbg(dev, "  send %d (%d/ %d/ %d/ %d)\n",
                usbhs_pipe_number(pipe),
                remainder, send, is_done, req->zero);

        /*
         * enable interrupt and send again in irq handler
         * if it still have remainder data which should be sent.
         */
        enable = !is_done;
        uep->handler->irq_mask(uep, enable);

        /*
         * usbhs_fifo_enable execute
         *  - after callback_update,
         *  - before queue_pop / stage_end
         */
        usbhs_fifo_enable(pipe);

        /*
         * all data were sent ?
         */
        if (is_done) {
                /* it care below call in
                   "function mode" */
                if (usbhsg_is_dcp(uep))
                        usbhs_dcp_control_transfer_done(pipe);

                usbhsg_queue_pop(uep, ureq, 0);
        }

        return 0;
}

static int usbhsg_prepare_send_packet(struct usbhsg_uep *uep,
                                      struct usbhsg_request *ureq)
{
        struct usbhs_pipe *pipe = usbhsg_uep_to_pipe(uep);

        /*
         *********  assume under spin lock  *********
         */

        usbhs_fifo_prepare_write(pipe);
        usbhsg_try_run_send_packet(uep, ureq);

        return 0;
}

static int usbhsg_try_run_receive_packet(struct usbhsg_uep *uep,
                                         struct usbhsg_request *ureq)
{
        struct usbhs_pipe *pipe = usbhsg_uep_to_pipe(uep);
        struct usb_request *req = &ureq->req;
        struct usbhsg_gpriv *gpriv = usbhsg_uep_to_gpriv(uep);
        struct device *dev = usbhsg_gpriv_to_dev(gpriv);
        void *buf;
        int maxp;
        int remainder, recv;
        int is_done = 0;

        /*
         *********  assume under spin lock  *********
         */

        maxp            = usbhs_pipe_get_maxpacket(pipe);
        buf             = req->buf    + req->actual;
        remainder       = req->length - req->actual;

        recv = usbhs_fifo_read(pipe, buf, remainder);
        /*
         * recv < 0  : pipe busy
         * recv >= 0 : receive data
         *
         * recv <= max_packet
         */
        if (recv < 0)
                return -EBUSY;

        /* update parameters */
        req->actual += recv;

        if ((recv == remainder) ||      /* receive all data */
            (recv < maxp))              /* short packet */
                is_done = 1;

        dev_dbg(dev, "  recv %d (%d/ %d/ %d/ %d)\n",
                usbhs_pipe_number(pipe),
                remainder, recv, is_done, req->zero);

        /* read all data ? */
        if (is_done) {
                int disable = 0;

                uep->handler->irq_mask(uep, disable);
                usbhs_fifo_disable(pipe);
                usbhsg_queue_pop(uep, ureq, 0);
        }

        return 0;
}

static int usbhsg_prepare_receive_packet(struct usbhsg_uep *uep,
                                         struct usbhsg_request *ureq)
{
        struct usbhs_pipe *pipe = usbhsg_uep_to_pipe(uep);
        int enable = 1;
        int ret;

        /*
         *********  assume under spin lock  *********
         */

        ret = usbhs_fifo_prepare_read(pipe);
        if (ret < 0)
                return ret;

        /*
         * data will be read in interrupt handler
         */
        uep->handler->irq_mask(uep, enable);

        return ret;
}

static struct usbhsg_pipe_handle usbhsg_handler_send_by_empty = {
        .prepare        = usbhsg_prepare_send_packet,
        .try_run        = usbhsg_try_run_send_packet,
        .irq_mask       = usbhsg_irq_empty_ctrl,
};

static struct usbhsg_pipe_handle usbhsg_handler_send_by_ready = {
        .prepare        = usbhsg_prepare_send_packet,
        .try_run        = usbhsg_try_run_send_packet,
        .irq_mask       = usbhsg_irq_ready_ctrl,
};

static struct usbhsg_pipe_handle usbhsg_handler_recv_by_ready = {
        .prepare        = usbhsg_prepare_receive_packet,
        .try_run        = usbhsg_try_run_receive_packet,
        .irq_mask       = usbhsg_irq_ready_ctrl,
};

static struct usbhsg_pipe_handle usbhsg_handler_ctrl_stage_end = {
        .prepare        = usbhsg_try_run_ctrl_stage_end,
        .try_run        = usbhsg_try_run_ctrl_stage_end,
};

/*
 * DCP pipe can NOT use "ready interrupt" for "send"
 * it should use "empty" interrupt.
 * see
 *   "Operation" - "Interrupt Function" - "BRDY Interrupt"
 *
 * on the other hand, normal pipe can use "ready interrupt" for "send"
 * even though it is single/double buffer
 */
#define usbhsg_handler_send_ctrl        usbhsg_handler_send_by_empty
#define usbhsg_handler_recv_ctrl        usbhsg_handler_recv_by_ready

#define usbhsg_handler_send_packet      usbhsg_handler_send_by_ready
#define usbhsg_handler_recv_packet      usbhsg_handler_recv_by_ready

/*
 *              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_fifo_disable(pipe);
                usbhs_pipe_clear_sequence(pipe);
                usbhs_fifo_enable(pipe);
        }

        usbhsg_recip_handler_std_control_done(priv, uep, ctrl);

        usbhsg_queue_prepare(uep);

        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;
        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);

        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) {
                dev_dbg(dev, "%s (pipe %d :%s)\n", handler->name, nth, msg);
                ret = func(priv, uep, ctrl);
        }

        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_status_get_usb_speed(irq_state);

        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:
                dcp->handler = &usbhsg_handler_send_ctrl;
                break;
        case WRITE_DATA_STAGE:
                dcp->handler = &usbhsg_handler_recv_ctrl;
                break;
        case NODATA_STATUS_STAGE:
                dcp->handler = &usbhsg_handler_ctrl_stage_end;
                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_fifo_stall(pipe);

        return ret;
}

static int usbhsg_irq_empty(struct usbhs_priv *priv,
                            struct usbhs_irq_state *irq_state)
{
        struct usbhsg_gpriv *gpriv = usbhsg_priv_to_gpriv(priv);
        struct usbhsg_uep *uep;
        struct usbhs_pipe *pipe;
        struct device *dev = usbhsg_gpriv_to_dev(gpriv);
        int i, ret;

        if (!irq_state->bempsts) {
                dev_err(dev, "debug %s !!\n", __func__);
                return -EIO;
        }

        dev_dbg(dev, "irq empty [0x%04x]\n", irq_state->bempsts);

        /*
         * search interrupted "pipe"
         * not "uep".
         */
        usbhs_for_each_pipe_with_dcp(pipe, priv, i) {
                if (!(irq_state->bempsts & (1 << i)))
                        continue;

                uep     = usbhsg_pipe_to_uep(pipe);
                ret     = usbhsg_queue_handle(uep);
                if (ret < 0)
                        dev_err(dev, "send error %d : %d\n", i, ret);
        }

        return 0;
}

static int usbhsg_irq_ready(struct usbhs_priv *priv,
                            struct usbhs_irq_state *irq_state)
{
        struct usbhsg_gpriv *gpriv = usbhsg_priv_to_gpriv(priv);
        struct usbhsg_uep *uep;
        struct usbhs_pipe *pipe;
        struct device *dev = usbhsg_gpriv_to_dev(gpriv);
        int i, ret;

        if (!irq_state->brdysts) {
                dev_err(dev, "debug %s !!\n", __func__);
                return -EIO;
        }

        dev_dbg(dev, "irq ready [0x%04x]\n", irq_state->brdysts);

        /*
         * search interrupted "pipe"
         * not "uep".
         */
        usbhs_for_each_pipe_with_dcp(pipe, priv, i) {
                if (!(irq_state->brdysts & (1 << i)))
                        continue;

                uep     = usbhsg_pipe_to_uep(pipe);
                ret     = usbhsg_queue_handle(uep);
                if (ret < 0)
                        dev_err(dev, "receive error %d : %d\n", i, ret);
        }

        return 0;
}

/*
 *
 *              usb_dcp_ops
 *
 */
static int usbhsg_dcp_enable(struct usbhsg_uep *uep)
{
        struct usbhsg_gpriv *gpriv = usbhsg_uep_to_gpriv(uep);
        struct usbhs_priv *priv = usbhsg_gpriv_to_priv(gpriv);
        struct usbhs_pipe *pipe;

        /*
         *********  assume under spin lock  *********
         */

        pipe = usbhs_dcp_malloc(priv);
        if (!pipe)
                return -EIO;

        uep->pipe               = pipe;
        uep->pipe->mod_private  = uep;
        INIT_LIST_HEAD(&uep->list);

        return 0;
}

#define usbhsg_dcp_disable usbhsg_pipe_disable
static int usbhsg_pipe_disable(struct usbhsg_uep *uep)
{
        struct usbhs_pipe *pipe = usbhsg_uep_to_pipe(uep);
        struct usbhsg_request *ureq;
        int disable = 0;

        /*
         *********  assume under spin lock  *********
         */

        usbhs_fifo_disable(pipe);

        /*
         * disable pipe irq
         */
        usbhsg_irq_empty_ctrl(uep, disable);
        usbhsg_irq_ready_ctrl(uep, disable);

        while (1) {
                ureq = usbhsg_queue_get(uep);
                if (!ureq)
                        break;

                usbhsg_queue_pop(uep, ureq, -ECONNRESET);
        }

        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;
        spinlock_t *lock = usbhsg_gpriv_to_lock(gpriv);
        unsigned long flags;
        int ret = -EIO;

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

        /********************  spin lock ********************/
        spin_lock_irqsave(lock, flags);

        pipe = usbhs_pipe_malloc(priv, desc);
        if (pipe) {
                uep->pipe               = pipe;
                pipe->mod_private       = uep;
                INIT_LIST_HEAD(&uep->list);

                if (usb_endpoint_dir_in(desc))
                        uep->handler = &usbhsg_handler_send_packet;
                else
                        uep->handler = &usbhsg_handler_recv_packet;

                ret = 0;
        }
        spin_unlock_irqrestore(lock, flags);
        /********************  spin unlock ******************/

        return ret;
}

static int usbhsg_ep_disable(struct usb_ep *ep)
{
        struct usbhsg_uep *uep = usbhsg_ep_to_uep(ep);
        struct usbhsg_gpriv *gpriv = usbhsg_uep_to_gpriv(uep);
        spinlock_t *lock = usbhsg_gpriv_to_lock(gpriv);
        unsigned long flags;
        int ret;

        /********************  spin lock ********************/
        spin_lock_irqsave(lock, flags);
        ret = usbhsg_pipe_disable(uep);
        spin_unlock_irqrestore(lock, flags);
        /********************  spin unlock ******************/

        return ret;
}

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;

        INIT_LIST_HEAD(&ureq->node);
        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->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);
        spinlock_t *lock = usbhsg_gpriv_to_lock(gpriv);
        unsigned long flags;
        int ret = 0;
        int is_locked;

        /*
         * CAUTION [*endpoint queue*]
         *
         * This function will be called from usb_request :: complete
         * or usb driver timing.
         * If this function is called from usb_request :: complete,
         * it is already under spinlock on this driver.
         * but it is called frm usb driver, this function should call spinlock.
         *
         * This function is using spin_trylock_irqsave to solve this issue.
         * if "is_locked" is 1, this mean this function lock it.
         * but if it is 0, this mean it is already under spin lock.
         * see also
         *   CAUTION [*queue handler*]
         *   CAUTION [*request complete*]
         */

        /********************  spin lock ********************/
        is_locked = spin_trylock_irqsave(lock, flags);

        /* param check */
        if (usbhsg_is_not_connected(gpriv)      ||
            unlikely(!gpriv->driver)            ||
            unlikely(!pipe))
                ret = -ESHUTDOWN;
        else
                usbhsg_queue_push(uep, ureq);

        if (is_locked)
                spin_unlock_irqrestore(lock, flags);
        /********************  spin unlock ******************/

        usbhsg_queue_prepare(uep);

        return ret;
}

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 usbhsg_gpriv *gpriv = usbhsg_uep_to_gpriv(uep);
        spinlock_t *lock = usbhsg_gpriv_to_lock(gpriv);
        unsigned long flags;
        int is_locked;

        /*
         * see
         *   CAUTION [*queue handler*]
         *   CAUTION [*endpoint queue*]
         *   CAUTION [*request complete*]
         */

        /********************  spin lock ********************/
        is_locked = spin_trylock_irqsave(lock, flags);

        usbhsg_queue_pop(uep, ureq, -ECONNRESET);

        if (is_locked)
                spin_unlock_irqrestore(lock, flags);
        /********************  spin unlock ******************/

        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 device *dev = usbhsg_gpriv_to_dev(gpriv);
        spinlock_t *lock = usbhsg_gpriv_to_lock(gpriv);
        unsigned long flags;
        int ret = -EAGAIN;
        int is_locked;

        /*
         * see
         *   CAUTION [*queue handler*]
         *   CAUTION [*endpoint queue*]
         *   CAUTION [*request complete*]
         */

        /********************  spin lock ********************/
        is_locked = spin_trylock_irqsave(lock, flags);
        if (!usbhsg_queue_get(uep)) {

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

                if (halt)
                        usbhs_fifo_stall(pipe);
                else
                        usbhs_fifo_disable(pipe);

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

                ret = 0;
        }

        if (is_locked)
                spin_unlock_irqrestore(lock, flags);
        /********************  spin unlock ******************/

        return ret;
}

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);
        spinlock_t *lock = usbhsg_gpriv_to_lock(gpriv);
        unsigned long flags;

        /********************  spin lock ********************/
        spin_lock_irqsave(lock, flags);

        /*
         * enable interrupt and systems if ready
         */
        usbhsg_status_set(gpriv, status);
        if (!(usbhsg_status_has(gpriv, USBHSG_STATUS_STARTED) &&
              usbhsg_status_has(gpriv, USBHSG_STATUS_REGISTERD)))
                goto usbhsg_try_start_unlock;

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

        /*
         * pipe initialize and enable DCP
         */
        usbhs_pipe_init(priv);
        usbhsg_uep_init(gpriv);
        usbhsg_dcp_enable(dcp);

        /*
         * 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;
        mod->irq_empty          = usbhsg_irq_empty;
        mod->irq_ready          = usbhsg_irq_ready;
        mod->irq_bempsts        = 0;
        mod->irq_brdysts        = 0;
        usbhs_irq_callback_update(priv, mod);

usbhsg_try_start_unlock:
        spin_unlock_irqrestore(lock, flags);
        /********************  spin unlock ********************/

        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);
        spinlock_t *lock = usbhsg_gpriv_to_lock(gpriv);
        unsigned long flags;

        /********************  spin lock ********************/
        spin_lock_irqsave(lock, flags);

        /*
         * disable interrupt and systems if 1st try
         */
        usbhsg_status_clr(gpriv, status);
        if (!usbhsg_status_has(gpriv, USBHSG_STATUS_STARTED) &&
            !usbhsg_status_has(gpriv, USBHSG_STATUS_REGISTERD))
                goto usbhsg_try_stop_unlock;

        /* disable all irq */
        mod->irq_dev_state      = NULL;
        mod->irq_ctrl_stage     = NULL;
        mod->irq_empty          = NULL;
        mod->irq_ready          = NULL;
        mod->irq_bempsts        = 0;
        mod->irq_brdysts        = 0;
        usbhs_irq_callback_update(priv, mod);

        usbhsg_dcp_disable(dcp);

        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);

        spin_unlock_irqrestore(lock, flags);
        /********************  spin unlock ********************/

        if (gpriv->driver &&
            gpriv->driver->disconnect)
                gpriv->driver->disconnect(&gpriv->gadget);

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

        return 0;

usbhsg_try_stop_unlock:
        spin_unlock_irqrestore(lock, flags);

        return 0;
}

/*
 *
 *              linux usb function
 *
 */
struct usbhsg_gpriv *the_controller;
int usb_gadget_probe_driver(struct usb_gadget_driver *driver,
                            int (*bind)(struct usb_gadget *))
{
        struct usbhsg_gpriv *gpriv = the_controller;
        struct usbhs_priv *priv;
        struct device *dev;
        int ret;

        if (!bind               ||
            !driver             ||
            !driver->setup      ||
            driver->speed != USB_SPEED_HIGH)
                return -EINVAL;
        if (!gpriv)
                return -ENODEV;
        if (gpriv->driver)
                return -EBUSY;

        dev  = usbhsg_gpriv_to_dev(gpriv);
        priv = usbhsg_gpriv_to_priv(gpriv);

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

        ret = device_add(&gpriv->gadget.dev);
        if (ret) {
                dev_err(dev, "device_add error %d\n", ret);
                goto add_fail;
        }

        ret = bind(&gpriv->gadget);
        if (ret) {
                dev_err(dev, "bind to driver %s error %d\n",
                        driver->driver.name, ret);
                goto bind_fail;
        }

        dev_dbg(dev, "bind %s\n", driver->driver.name);

        return usbhsg_try_start(priv, USBHSG_STATUS_REGISTERD);

bind_fail:
        device_del(&gpriv->gadget.dev);
add_fail:
        gpriv->driver = NULL;
        gpriv->gadget.dev.driver = NULL;

        return ret;
}
EXPORT_SYMBOL(usb_gadget_probe_driver);

int usb_gadget_unregister_driver(struct usb_gadget_driver *driver)
{
        struct usbhsg_gpriv *gpriv = the_controller;
        struct usbhs_priv *priv;
        struct device *dev = usbhsg_gpriv_to_dev(gpriv);

        if (!gpriv)
                return -ENODEV;

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

        dev  = usbhsg_gpriv_to_dev(gpriv);
        priv = usbhsg_gpriv_to_priv(gpriv);

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

        if (driver->disconnect)
                driver->disconnect(&gpriv->gadget);

        driver->unbind(&gpriv->gadget);
        dev_dbg(dev, "unbind %s\n", driver->driver.name);

        return 0;
}
EXPORT_SYMBOL(usb_gadget_unregister_driver);

/*
 *              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,
};

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

static int usbhsg_stop(struct usbhs_priv *priv)
{
        return usbhsg_try_stop(priv, USBHSG_STATUS_STARTED);
}

int __devinit 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;

        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");
                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
         */
        device_initialize(&gpriv->gadget.dev);
        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;

        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_LIST_HEAD(&uep->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);
                }
        }

        the_controller = gpriv;

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

        return 0;

usbhs_mod_gadget_probe_err_gpriv:
        kfree(gpriv);

        return -ENOMEM;
}

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

        kfree(gpriv);
}