mod_host.c

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/*
 * Renesas USB driver
 *
 * Copyright (C) 2011 Renesas Solutions Corp.
 * Kuninori Morimoto <[email protected]>
 *
 * 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/list.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/usb.h>
#include <linux/usb/hcd.h>
#include "common.h"

/*
 *** HARDWARE LIMITATION ***
 *
 * 1) renesas_usbhs has a limited number of controllable devices.
 *    it can control only 9 devices in generally.
 *  see DEVADDn / DCPMAXP / PIPEMAXP.
 *
 * 2) renesas_usbhs pipe number is limited.
 *    the pipe will be re-used for each devices.
 *    so, software should control DATA0/1 sequence of each devices.
 */


/*
 *      image of mod_host
 *
 * +--------+
 * | udev 0 | --> it is used when set address
 * +--------+
 *
 * +--------+                   pipes are reused for each uep.
 * | udev 1 |-+- [uep 0 (dcp) ] --+     pipe will be switched when
 * +--------+ |           |     other device requested
 *        +- [uep 1 (bulk)] --|---+        +--------------+
 *        |           +--------------> | pipe0 (dcp)  |
 *        +- [uep 2 (bulk)] -@    |        +--------------+
 *                    |        | pipe1 (isoc) |
 * +--------+                 |        +--------------+
 * | udev 2 |-+- [uep 0 (dcp) ] -@    +----------> | pipe2 (bulk) |
 * +--------+ |                    +--------------+
 *        +- [uep 1 (int) ] ----+     +------> | pipe3 (bulk) |
 *                  |     |    +--------------+
 * +--------+               +-----|------> | pipe4 (int)  |
 * | udev 3 |-+- [uep 0 (dcp) ] -@    |    +--------------+
 * +--------+ |               |    | ....     |
 *        +- [uep 1 (bulk)] -@    |    | ....     |
 *        |               |
 *        +- [uep 2 (bulk)]-----------+
 *
 * @ :  uep requested free pipe, but all have been used.
 *  now it is waiting for free pipe
 */


/*
 *      struct
 */
struct usbhsh_request {
    struct urb      *urb;
    struct usbhs_pkt    pkt;
};

struct usbhsh_device {
    struct usb_device   *usbv;
    struct list_head    ep_list_head; /* list of usbhsh_ep */
};

struct usbhsh_ep {
    struct usbhs_pipe   *pipe;   /* attached pipe */
    struct usbhsh_device    *udev;   /* attached udev */
    struct usb_host_endpoint *ep;
    struct list_head    ep_list; /* list to usbhsh_device */
};

#define USBHSH_DEVICE_MAX   10 /* see DEVADDn / DCPMAXP / PIPEMAXP */
#define USBHSH_PORT_MAX      7 /* see DEVADDn :: HUBPORT */
struct usbhsh_hpriv {
    struct usbhs_mod    mod;
    struct usbhs_pipe   *dcp;

    struct usbhsh_device    udev[USBHSH_DEVICE_MAX];

    u32 port_stat;  /* USB_PORT_STAT_xxx */

    struct completion   setup_ack_done;
};


static const char usbhsh_hcd_name[] = "renesas_usbhs host";

/*
 *      macro
 */
#define usbhsh_priv_to_hpriv(priv) \
    container_of(usbhs_mod_get(priv, USBHS_HOST), struct usbhsh_hpriv, mod)

#define __usbhsh_for_each_udev(start, pos, h, i)    \
    for (i = start, pos = (h)->udev + i;        \
         i < USBHSH_DEVICE_MAX;         \
         i++, pos = (h)->udev + i)

#define usbhsh_for_each_udev(pos, hpriv, i) \
    __usbhsh_for_each_udev(1, pos, hpriv, i)

#define usbhsh_for_each_udev_with_dev0(pos, hpriv, i)   \
    __usbhsh_for_each_udev(0, pos, hpriv, i)

#define usbhsh_hcd_to_hpriv(h)  (struct usbhsh_hpriv *)((h)->hcd_priv)
#define usbhsh_hcd_to_dev(h)    ((h)->self.controller)

#define usbhsh_hpriv_to_priv(h) ((h)->mod.priv)
#define usbhsh_hpriv_to_dcp(h)  ((h)->dcp)
#define usbhsh_hpriv_to_hcd(h)  \
    container_of((void *)h, struct usb_hcd, hcd_priv)

#define usbhsh_ep_to_uep(u) ((u)->hcpriv)
#define usbhsh_uep_to_pipe(u)   ((u)->pipe)
#define usbhsh_uep_to_udev(u)   ((u)->udev)
#define usbhsh_uep_to_ep(u) ((u)->ep)

#define usbhsh_urb_to_ureq(u)   ((u)->hcpriv)
#define usbhsh_urb_to_usbv(u)   ((u)->dev)

#define usbhsh_usbv_to_udev(d)  dev_get_drvdata(&(d)->dev)

#define usbhsh_udev_to_usbv(h)  ((h)->usbv)
#define usbhsh_udev_is_used(h)  usbhsh_udev_to_usbv(h)

#define usbhsh_pipe_to_uep(p)   ((p)->mod_private)

#define usbhsh_device_parent(d)     (usbhsh_usbv_to_udev((d)->usbv->parent))
#define usbhsh_device_hubport(d)    ((d)->usbv->portnum)
#define usbhsh_device_number(h, d)  ((int)((d) - (h)->udev))
#define usbhsh_device_nth(h, d)     ((h)->udev + d)
#define usbhsh_device0(h)       usbhsh_device_nth(h, 0)

#define usbhsh_port_stat_init(h)    ((h)->port_stat = 0)
#define usbhsh_port_stat_set(h, s)  ((h)->port_stat |= (s))
#define usbhsh_port_stat_clear(h, s)    ((h)->port_stat &= ~(s))
#define usbhsh_port_stat_get(h)     ((h)->port_stat)

#define usbhsh_pkt_to_ureq(p)   \
    container_of((void *)p, struct usbhsh_request, pkt)

/*
 *      req alloc/free
 */
static struct usbhsh_request *usbhsh_ureq_alloc(struct usbhsh_hpriv *hpriv,
                           struct urb *urb,
                           gfp_t mem_flags)
{
    struct usbhsh_request *ureq;
    struct usbhs_priv *priv = usbhsh_hpriv_to_priv(hpriv);
    struct device *dev = usbhs_priv_to_dev(priv);

    ureq = kzalloc(sizeof(struct usbhsh_request), mem_flags);
    if (!ureq) {
        dev_err(dev, "ureq alloc fail\n");
        return NULL;
    }

    usbhs_pkt_init(&ureq->pkt);
    ureq->urb = urb;
    usbhsh_urb_to_ureq(urb) = ureq;

    return ureq;
}

static void usbhsh_ureq_free(struct usbhsh_hpriv *hpriv,
                struct usbhsh_request *ureq)
{
    usbhsh_urb_to_ureq(ureq->urb) = NULL;
    ureq->urb = NULL;

    kfree(ureq);
}

/*
 *      status
 */
static int usbhsh_is_running(struct usbhsh_hpriv *hpriv)
{
    /*
     * we can decide some device is attached or not
     * by checking mod.irq_attch
     * see
     *  usbhsh_irq_attch()
     *  usbhsh_irq_dtch()
     */
    return (hpriv->mod.irq_attch == NULL);
}

/*
 *      pipe control
 */
static void usbhsh_endpoint_sequence_save(struct usbhsh_hpriv *hpriv,
                      struct urb *urb,
                      struct usbhs_pkt *pkt)
{
    int len = urb->actual_length;
    int maxp = usb_endpoint_maxp(&urb->ep->desc);
    int t = 0;

    /* DCP is out of sequence control */
    if (usb_pipecontrol(urb->pipe))
        return;

    /*
     * renesas_usbhs pipe has a limitation in a number.
     * So, driver should re-use the limited pipe for each device/endpoint.
     * DATA0/1 sequence should be saved for it.
     * see [image of mod_host]
     *     [HARDWARE LIMITATION]
     */

    /*
     * next sequence depends on actual_length
     *
     * ex) actual_length = 1147, maxp = 512
     * data0 : 512
     * data1 : 512
     * data0 : 123
     * data1 is the next sequence
     */
    t = len / maxp;
    if (len % maxp)
        t++;
    if (pkt->zero)
        t++;
    t %= 2;

    if (t)
        usb_dotoggle(urb->dev,
                 usb_pipeendpoint(urb->pipe),
                 usb_pipeout(urb->pipe));
}

static struct usbhsh_device *usbhsh_device_get(struct usbhsh_hpriv *hpriv,
                           struct urb *urb);

static int usbhsh_pipe_attach(struct usbhsh_hpriv *hpriv,
                  struct urb *urb)
{
    struct usbhs_priv *priv = usbhsh_hpriv_to_priv(hpriv);
    struct usbhsh_ep *uep = usbhsh_ep_to_uep(urb->ep);
    struct usbhsh_device *udev = usbhsh_device_get(hpriv, urb);
    struct usbhs_pipe *pipe;
    struct usb_endpoint_descriptor *desc = &urb->ep->desc;
    struct device *dev = usbhs_priv_to_dev(priv);
    unsigned long flags;
    int dir_in_req = !!usb_pipein(urb->pipe);
    int is_dcp = usb_endpoint_xfer_control(desc);
    int i, dir_in;
    int ret = -EBUSY;

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

    if (unlikely(usbhsh_uep_to_pipe(uep))) {
        dev_err(dev, "uep already has pipe\n");
        goto usbhsh_pipe_attach_done;
    }

    usbhs_for_each_pipe_with_dcp(pipe, priv, i) {

        /* check pipe type */
        if (!usbhs_pipe_type_is(pipe, usb_endpoint_type(desc)))
            continue;

        /* check pipe direction if normal pipe */
        if (!is_dcp) {
            dir_in = !!usbhs_pipe_is_dir_in(pipe);
            if (0 != (dir_in - dir_in_req))
                continue;
        }

        /* check pipe is free */
        if (usbhsh_pipe_to_uep(pipe))
            continue;

        /*
         * attach pipe to uep
         *
         * usbhs_pipe_config_update() should be called after
         * usbhs_set_device_config()
         * see
         *  DCPMAXP/PIPEMAXP
         */
        usbhsh_uep_to_pipe(uep)     = pipe;
        usbhsh_pipe_to_uep(pipe)    = uep;

        usbhs_pipe_config_update(pipe,
                     usbhsh_device_number(hpriv, udev),
                     usb_endpoint_num(desc),
                     usb_endpoint_maxp(desc));

        dev_dbg(dev, "%s [%d-%d(%s:%s)]\n", __func__,
            usbhsh_device_number(hpriv, udev),
            usb_endpoint_num(desc),
            usbhs_pipe_name(pipe),
            dir_in_req ? "in" : "out");

        ret = 0;
        break;
    }

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

    return ret;
}

static void usbhsh_pipe_detach(struct usbhsh_hpriv *hpriv,
                   struct usbhsh_ep *uep)
{
    struct usbhs_priv *priv = usbhsh_hpriv_to_priv(hpriv);
    struct usbhs_pipe *pipe;
    struct device *dev = usbhs_priv_to_dev(priv);
    unsigned long flags;

    if (unlikely(!uep)) {
        dev_err(dev, "no uep\n");
        return;
    }

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

    pipe = usbhsh_uep_to_pipe(uep);

    if (unlikely(!pipe)) {
        dev_err(dev, "uep doens't have pipe\n");
    } else {
        struct usb_host_endpoint *ep = usbhsh_uep_to_ep(uep);
        struct usbhsh_device *udev = usbhsh_uep_to_udev(uep);

        /* detach pipe from uep */
        usbhsh_uep_to_pipe(uep)     = NULL;
        usbhsh_pipe_to_uep(pipe)    = NULL;

        dev_dbg(dev, "%s [%d-%d(%s)]\n", __func__,
            usbhsh_device_number(hpriv, udev),
            usb_endpoint_num(&ep->desc),
            usbhs_pipe_name(pipe));
    }

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

/*
 *      endpoint control
 */
static int usbhsh_endpoint_attach(struct usbhsh_hpriv *hpriv,
                  struct urb *urb,
                  gfp_t mem_flags)
{
    struct usbhs_priv *priv = usbhsh_hpriv_to_priv(hpriv);
    struct usbhsh_device *udev = usbhsh_device_get(hpriv, urb);
    struct usb_host_endpoint *ep = urb->ep;
    struct usbhsh_ep *uep;
    struct device *dev = usbhs_priv_to_dev(priv);
    struct usb_endpoint_descriptor *desc = &ep->desc;
    unsigned long flags;

    uep = kzalloc(sizeof(struct usbhsh_ep), mem_flags);
    if (!uep) {
        dev_err(dev, "usbhsh_ep alloc fail\n");
        return -ENOMEM;
    }

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

    /*
     * init endpoint
     */
    INIT_LIST_HEAD(&uep->ep_list);
    list_add_tail(&uep->ep_list, &udev->ep_list_head);

    usbhsh_uep_to_udev(uep) = udev;
    usbhsh_uep_to_ep(uep)   = ep;
    usbhsh_ep_to_uep(ep)    = uep;

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

    dev_dbg(dev, "%s [%d-%d]\n", __func__,
        usbhsh_device_number(hpriv, udev),
        usb_endpoint_num(desc));

    return 0;
}

static void usbhsh_endpoint_detach(struct usbhsh_hpriv *hpriv,
                   struct usb_host_endpoint *ep)
{
    struct usbhs_priv *priv = usbhsh_hpriv_to_priv(hpriv);
    struct device *dev = usbhs_priv_to_dev(priv);
    struct usbhsh_ep *uep = usbhsh_ep_to_uep(ep);
    unsigned long flags;

    if (!uep)
        return;

    dev_dbg(dev, "%s [%d-%d]\n", __func__,
        usbhsh_device_number(hpriv, usbhsh_uep_to_udev(uep)),
        usb_endpoint_num(&ep->desc));

    if (usbhsh_uep_to_pipe(uep))
        usbhsh_pipe_detach(hpriv, uep);

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

    /* remove this endpoint from udev */
    list_del_init(&uep->ep_list);

    usbhsh_uep_to_udev(uep) = NULL;
    usbhsh_uep_to_ep(uep)   = NULL;
    usbhsh_ep_to_uep(ep)    = NULL;

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

    kfree(uep);
}

static void usbhsh_endpoint_detach_all(struct usbhsh_hpriv *hpriv,
                       struct usbhsh_device *udev)
{
    struct usbhsh_ep *uep, *next;

    list_for_each_entry_safe(uep, next, &udev->ep_list_head, ep_list)
        usbhsh_endpoint_detach(hpriv, usbhsh_uep_to_ep(uep));
}

/*
 *      device control
 */
static int usbhsh_connected_to_rhdev(struct usb_hcd *hcd,
                     struct usbhsh_device *udev)
{
    struct usb_device *usbv = usbhsh_udev_to_usbv(udev);

    return hcd->self.root_hub == usbv->parent;
}

static int usbhsh_device_has_endpoint(struct usbhsh_device *udev)
{
    return !list_empty(&udev->ep_list_head);
}

static struct usbhsh_device *usbhsh_device_get(struct usbhsh_hpriv *hpriv,
                           struct urb *urb)
{
    struct usb_device *usbv = usbhsh_urb_to_usbv(urb);
    struct usbhsh_device *udev = usbhsh_usbv_to_udev(usbv);

    /* usbhsh_device_attach() is still not called */
    if (!udev)
        return NULL;

    /* if it is device0, return it */
    if (0 == usb_pipedevice(urb->pipe))
        return usbhsh_device0(hpriv);

    /* return attached device */
    return udev;
}

static struct usbhsh_device *usbhsh_device_attach(struct usbhsh_hpriv *hpriv,
                         struct urb *urb)
{
    struct usbhsh_device *udev = NULL;
    struct usbhsh_device *udev0 = usbhsh_device0(hpriv);
    struct usbhsh_device *pos;
    struct usb_hcd *hcd = usbhsh_hpriv_to_hcd(hpriv);
    struct device *dev = usbhsh_hcd_to_dev(hcd);
    struct usb_device *usbv = usbhsh_urb_to_usbv(urb);
    struct usbhs_priv *priv = usbhsh_hpriv_to_priv(hpriv);
    unsigned long flags;
    u16 upphub, hubport;
    int i;

    /*
     * This function should be called only while urb is pointing to device0.
     * It will attach unused usbhsh_device to urb (usbv),
     * and initialize device0.
     * You can use usbhsh_device_get() to get "current" udev,
     * and usbhsh_usbv_to_udev() is for "attached" udev.
     */
    if (0 != usb_pipedevice(urb->pipe)) {
        dev_err(dev, "%s fail: urb isn't pointing device0\n", __func__);
        return NULL;
    }

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

    /*
     * find unused device
     */
    usbhsh_for_each_udev(pos, hpriv, i) {
        if (usbhsh_udev_is_used(pos))
            continue;
        udev = pos;
        break;
    }

    if (udev) {
        /*
         * usbhsh_usbv_to_udev()
         * usbhsh_udev_to_usbv()
         * will be enable
         */
        dev_set_drvdata(&usbv->dev, udev);
        udev->usbv = usbv;
    }

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

    if (!udev) {
        dev_err(dev, "no free usbhsh_device\n");
        return NULL;
    }

    if (usbhsh_device_has_endpoint(udev)) {
        dev_warn(dev, "udev have old endpoint\n");
        usbhsh_endpoint_detach_all(hpriv, udev);
    }

    if (usbhsh_device_has_endpoint(udev0)) {
        dev_warn(dev, "udev0 have old endpoint\n");
        usbhsh_endpoint_detach_all(hpriv, udev0);
    }

    /* uep will be attached */
    INIT_LIST_HEAD(&udev0->ep_list_head);
    INIT_LIST_HEAD(&udev->ep_list_head);

    /*
     * set device0 config
     */
    usbhs_set_device_config(priv,
                0, 0, 0, usbv->speed);

    /*
     * set new device config
     */
    upphub  = 0;
    hubport = 0;
    if (!usbhsh_connected_to_rhdev(hcd, udev)) {
        /* if udev is not connected to rhdev, it means parent is Hub */
        struct usbhsh_device *parent = usbhsh_device_parent(udev);

        upphub  = usbhsh_device_number(hpriv, parent);
        hubport = usbhsh_device_hubport(udev);

        dev_dbg(dev, "%s connecte to Hub [%d:%d](%p)\n", __func__,
            upphub, hubport, parent);
    }

    usbhs_set_device_config(priv,
                   usbhsh_device_number(hpriv, udev),
                   upphub, hubport, usbv->speed);

    dev_dbg(dev, "%s [%d](%p)\n", __func__,
        usbhsh_device_number(hpriv, udev), udev);

    return udev;
}

static void usbhsh_device_detach(struct usbhsh_hpriv *hpriv,
                   struct usbhsh_device *udev)
{
    struct usb_hcd *hcd = usbhsh_hpriv_to_hcd(hpriv);
    struct usbhs_priv *priv = usbhsh_hpriv_to_priv(hpriv);
    struct device *dev = usbhsh_hcd_to_dev(hcd);
    struct usb_device *usbv = usbhsh_udev_to_usbv(udev);
    unsigned long flags;

    dev_dbg(dev, "%s [%d](%p)\n", __func__,
        usbhsh_device_number(hpriv, udev), udev);

    if (usbhsh_device_has_endpoint(udev)) {
        dev_warn(dev, "udev still have endpoint\n");
        usbhsh_endpoint_detach_all(hpriv, udev);
    }

    /*
     * There is nothing to do if it is device0.
     * see
     *  usbhsh_device_attach()
     *  usbhsh_device_get()
     */
    if (0 == usbhsh_device_number(hpriv, udev))
        return;

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

    /*
     * usbhsh_usbv_to_udev()
     * usbhsh_udev_to_usbv()
     * will be disable
     */
    dev_set_drvdata(&usbv->dev, NULL);
    udev->usbv = NULL;

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

/*
 *      queue push/pop
 */
static void usbhsh_queue_done(struct usbhs_priv *priv, struct usbhs_pkt *pkt)
{
    struct usbhsh_request *ureq = usbhsh_pkt_to_ureq(pkt);
    struct usbhsh_hpriv *hpriv = usbhsh_priv_to_hpriv(priv);
    struct usb_hcd *hcd = usbhsh_hpriv_to_hcd(hpriv);
    struct urb *urb = ureq->urb;
    struct device *dev = usbhs_priv_to_dev(priv);
    int status = 0;

    dev_dbg(dev, "%s\n", __func__);

    if (!urb) {
        dev_warn(dev, "pkt doesn't have urb\n");
        return;
    }

    if (!usbhsh_is_running(hpriv))
        status = -ESHUTDOWN;

    urb->actual_length = pkt->actual;
    usbhsh_ureq_free(hpriv, ureq);

    usbhsh_endpoint_sequence_save(hpriv, urb, pkt);
    usbhsh_pipe_detach(hpriv, usbhsh_ep_to_uep(urb->ep));

    usb_hcd_unlink_urb_from_ep(hcd, urb);
    usb_hcd_giveback_urb(hcd, urb, status);
}

static int usbhsh_queue_push(struct usb_hcd *hcd,
                 struct urb *urb,
                 gfp_t mem_flags)
{
    struct usbhsh_hpriv *hpriv = usbhsh_hcd_to_hpriv(hcd);
    struct usbhsh_ep *uep = usbhsh_ep_to_uep(urb->ep);
    struct usbhs_pipe *pipe = usbhsh_uep_to_pipe(uep);
    struct device *dev = usbhsh_hcd_to_dev(hcd);
    struct usbhsh_request *ureq;
    void *buf;
    int len, sequence;

    if (usb_pipeisoc(urb->pipe)) {
        dev_err(dev, "pipe iso is not supported now\n");
        return -EIO;
    }

    /* this ureq will be freed on usbhsh_queue_done() */
    ureq = usbhsh_ureq_alloc(hpriv, urb, mem_flags);
    if (unlikely(!ureq)) {
        dev_err(dev, "ureq alloc fail\n");
        return -ENOMEM;
    }

    if (usb_pipein(urb->pipe))
        pipe->handler = &usbhs_fifo_pio_pop_handler;
    else
        pipe->handler = &usbhs_fifo_pio_push_handler;

    buf = (void *)(urb->transfer_buffer + urb->actual_length);
    len = urb->transfer_buffer_length - urb->actual_length;

    sequence = usb_gettoggle(urb->dev,
                 usb_pipeendpoint(urb->pipe),
                 usb_pipeout(urb->pipe));

    dev_dbg(dev, "%s\n", __func__);
    usbhs_pkt_push(pipe, &ureq->pkt, usbhsh_queue_done,
               buf, len, (urb->transfer_flags & URB_ZERO_PACKET),
               sequence);

    usbhs_pkt_start(pipe);

    return 0;
}

static void usbhsh_queue_force_pop(struct usbhs_priv *priv,
                   struct usbhs_pipe *pipe)
{
    struct usbhs_pkt *pkt;

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

        /*
         * if all packet are gone, usbhsh_endpoint_disable()
         * will be called.
         * then, attached device/endpoint/pipe will be detached
         */
        usbhsh_queue_done(priv, pkt);
    }
}

static void usbhsh_queue_force_pop_all(struct usbhs_priv *priv)
{
    struct usbhs_pipe *pos;
    int i;

    usbhs_for_each_pipe_with_dcp(pos, priv, i)
        usbhsh_queue_force_pop(priv, pos);
}

/*
 *      DCP setup stage
 */
static int usbhsh_is_request_address(struct urb *urb)
{
    struct usb_ctrlrequest *req;

    req = (struct usb_ctrlrequest *)urb->setup_packet;

    if ((DeviceOutRequest    == req->bRequestType << 8) &&
        (USB_REQ_SET_ADDRESS == req->bRequest))
        return 1;
    else
        return 0;
}

static void usbhsh_setup_stage_packet_push(struct usbhsh_hpriv *hpriv,
                       struct urb *urb,
                       struct usbhs_pipe *pipe)
{
    struct usbhs_priv *priv = usbhsh_hpriv_to_priv(hpriv);
    struct usb_ctrlrequest req;
    struct device *dev = usbhs_priv_to_dev(priv);

    /*
     * wait setup packet ACK
     * see
     *  usbhsh_irq_setup_ack()
     *  usbhsh_irq_setup_err()
     */
    init_completion(&hpriv->setup_ack_done);

    /* copy original request */
    memcpy(&req, urb->setup_packet, sizeof(struct usb_ctrlrequest));

    /*
     * renesas_usbhs can not use original usb address.
     * see HARDWARE LIMITATION.
     * modify usb address here to use attached device.
     * see usbhsh_device_attach()
     */
    if (usbhsh_is_request_address(urb)) {
        struct usb_device *usbv = usbhsh_urb_to_usbv(urb);
        struct usbhsh_device *udev = usbhsh_usbv_to_udev(usbv);

        /* udev is a attached device */
        req.wValue = usbhsh_device_number(hpriv, udev);
        dev_dbg(dev, "create new address - %d\n", req.wValue);
    }

    /* set request */
    usbhs_usbreq_set_val(priv, &req);

    /*
     * wait setup packet ACK
     */
    wait_for_completion(&hpriv->setup_ack_done);

    dev_dbg(dev, "%s done\n", __func__);
}

/*
 *      DCP data stage
 */
static void usbhsh_data_stage_packet_done(struct usbhs_priv *priv,
                      struct usbhs_pkt *pkt)
{
    struct usbhsh_request *ureq = usbhsh_pkt_to_ureq(pkt);
    struct usbhsh_hpriv *hpriv = usbhsh_priv_to_hpriv(priv);

    /* this ureq was connected to urb when usbhsh_urb_enqueue()  */

    usbhsh_ureq_free(hpriv, ureq);
}

static int usbhsh_data_stage_packet_push(struct usbhsh_hpriv *hpriv,
                     struct urb *urb,
                     struct usbhs_pipe *pipe,
                     gfp_t mem_flags)

{
    struct usbhsh_request *ureq;

    /* this ureq will be freed on usbhsh_data_stage_packet_done() */
    ureq = usbhsh_ureq_alloc(hpriv, urb, mem_flags);
    if (unlikely(!ureq))
        return -ENOMEM;

    if (usb_pipein(urb->pipe))
        pipe->handler = &usbhs_dcp_data_stage_in_handler;
    else
        pipe->handler = &usbhs_dcp_data_stage_out_handler;

    usbhs_pkt_push(pipe, &ureq->pkt,
               usbhsh_data_stage_packet_done,
               urb->transfer_buffer,
               urb->transfer_buffer_length,
               (urb->transfer_flags & URB_ZERO_PACKET),
               -1);

    return 0;
}

/*
 *      DCP status stage
 */
static int usbhsh_status_stage_packet_push(struct usbhsh_hpriv *hpriv,
                        struct urb *urb,
                        struct usbhs_pipe *pipe,
                        gfp_t mem_flags)
{
    struct usbhsh_request *ureq;

    /* This ureq will be freed on usbhsh_queue_done() */
    ureq = usbhsh_ureq_alloc(hpriv, urb, mem_flags);
    if (unlikely(!ureq))
        return -ENOMEM;

    if (usb_pipein(urb->pipe))
        pipe->handler = &usbhs_dcp_status_stage_in_handler;
    else
        pipe->handler = &usbhs_dcp_status_stage_out_handler;

    usbhs_pkt_push(pipe, &ureq->pkt,
               usbhsh_queue_done,
               NULL,
               urb->transfer_buffer_length,
               0, -1);

    return 0;
}

static int usbhsh_dcp_queue_push(struct usb_hcd *hcd,
                 struct urb *urb,
                 gfp_t mflags)
{
    struct usbhsh_hpriv *hpriv = usbhsh_hcd_to_hpriv(hcd);
    struct usbhsh_ep *uep = usbhsh_ep_to_uep(urb->ep);
    struct usbhs_pipe *pipe = usbhsh_uep_to_pipe(uep);
    struct device *dev = usbhsh_hcd_to_dev(hcd);
    int ret;

    dev_dbg(dev, "%s\n", __func__);

    /*
     * setup stage
     *
     * usbhsh_send_setup_stage_packet() wait SACK/SIGN
     */
    usbhsh_setup_stage_packet_push(hpriv, urb, pipe);

    /*
     * data stage
     *
     * It is pushed only when urb has buffer.
     */
    if (urb->transfer_buffer_length) {
        ret = usbhsh_data_stage_packet_push(hpriv, urb, pipe, mflags);
        if (ret < 0) {
            dev_err(dev, "data stage failed\n");
            return ret;
        }
    }

    /*
     * status stage
     */
    ret = usbhsh_status_stage_packet_push(hpriv, urb, pipe, mflags);
    if (ret < 0) {
        dev_err(dev, "status stage failed\n");
        return ret;
    }

    /*
     * start pushed packets
     */
    usbhs_pkt_start(pipe);

    return 0;
}

/*
 *      dma map functions
 */
static int usbhsh_dma_map_ctrl(struct usbhs_pkt *pkt, int map)
{
    return 0;
}

/*
 *      for hc_driver
 */
static int usbhsh_host_start(struct usb_hcd *hcd)
{
    return 0;
}

static void usbhsh_host_stop(struct usb_hcd *hcd)
{
}

static int usbhsh_urb_enqueue(struct usb_hcd *hcd,
                  struct urb *urb,
                  gfp_t mem_flags)
{
    struct usbhsh_hpriv *hpriv = usbhsh_hcd_to_hpriv(hcd);
    struct usbhs_priv *priv = usbhsh_hpriv_to_priv(hpriv);
    struct device *dev = usbhs_priv_to_dev(priv);
    struct usb_host_endpoint *ep = urb->ep;
    struct usbhsh_device *new_udev = NULL;
    int is_dir_in = usb_pipein(urb->pipe);
    int i;
    int ret;

    dev_dbg(dev, "%s (%s)\n", __func__, is_dir_in ? "in" : "out");

    if (!usbhsh_is_running(hpriv)) {
        ret = -EIO;
        dev_err(dev, "host is not running\n");
        goto usbhsh_urb_enqueue_error_not_linked;
    }

    ret = usb_hcd_link_urb_to_ep(hcd, urb);
    if (ret) {
        dev_err(dev, "urb link failed\n");
        goto usbhsh_urb_enqueue_error_not_linked;
    }

    /*
     * attach udev if needed
     * see [image of mod_host]
     */
    if (!usbhsh_device_get(hpriv, urb)) {
        new_udev = usbhsh_device_attach(hpriv, urb);
        if (!new_udev) {
            ret = -EIO;
            dev_err(dev, "device attach failed\n");
            goto usbhsh_urb_enqueue_error_not_linked;
        }
    }

    /*
     * attach endpoint if needed
     * see [image of mod_host]
     */
    if (!usbhsh_ep_to_uep(ep)) {
        ret = usbhsh_endpoint_attach(hpriv, urb, mem_flags);
        if (ret < 0) {
            dev_err(dev, "endpoint attach failed\n");
            goto usbhsh_urb_enqueue_error_free_device;
        }
    }

    /*
     * attach pipe to endpoint
     * see [image of mod_host]
     */
    for (i = 0; i < 1024; i++) {
        ret = usbhsh_pipe_attach(hpriv, urb);
        if (ret < 0)
            msleep(100);
        else
            break;
    }
    if (ret < 0) {
        dev_err(dev, "pipe attach failed\n");
        goto usbhsh_urb_enqueue_error_free_endpoint;
    }

    /*
     * push packet
     */
    if (usb_pipecontrol(urb->pipe))
        ret = usbhsh_dcp_queue_push(hcd, urb, mem_flags);
    else
        ret = usbhsh_queue_push(hcd, urb, mem_flags);

    return ret;

usbhsh_urb_enqueue_error_free_endpoint:
    usbhsh_endpoint_detach(hpriv, ep);
usbhsh_urb_enqueue_error_free_device:
    if (new_udev)
        usbhsh_device_detach(hpriv, new_udev);
usbhsh_urb_enqueue_error_not_linked:

    dev_dbg(dev, "%s error\n", __func__);

    return ret;
}

static int usbhsh_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
{
    struct usbhsh_hpriv *hpriv = usbhsh_hcd_to_hpriv(hcd);
    struct usbhsh_request *ureq = usbhsh_urb_to_ureq(urb);

    if (ureq) {
        struct usbhs_priv *priv = usbhsh_hpriv_to_priv(hpriv);
        struct usbhs_pkt *pkt = &ureq->pkt;

        usbhs_pkt_pop(pkt->pipe, pkt);
        usbhsh_queue_done(priv, pkt);
    }

    return 0;
}

static void usbhsh_endpoint_disable(struct usb_hcd *hcd,
                    struct usb_host_endpoint *ep)
{
    struct usbhsh_ep *uep = usbhsh_ep_to_uep(ep);
    struct usbhsh_device *udev;
    struct usbhsh_hpriv *hpriv;

    /*
     * this function might be called manytimes by same hcd/ep
     * in-endpoint == out-endpoint if ep == dcp.
     */
    if (!uep)
        return;

    udev    = usbhsh_uep_to_udev(uep);
    hpriv   = usbhsh_hcd_to_hpriv(hcd);

    usbhsh_endpoint_detach(hpriv, ep);

    /*
     * if there is no endpoint,
     * free device
     */
    if (!usbhsh_device_has_endpoint(udev))
        usbhsh_device_detach(hpriv, udev);
}

static int usbhsh_hub_status_data(struct usb_hcd *hcd, char *buf)
{
    struct usbhsh_hpriv *hpriv = usbhsh_hcd_to_hpriv(hcd);
    struct usbhs_priv *priv = usbhsh_hpriv_to_priv(hpriv);
    struct device *dev = usbhs_priv_to_dev(priv);
    int roothub_id = 1; /* only 1 root hub */

    /*
     * does port stat was changed ?
     * check USB_PORT_STAT_C_xxx << 16
     */
    if (usbhsh_port_stat_get(hpriv) & 0xFFFF0000)
        *buf = (1 << roothub_id);
    else
        *buf = 0;

    dev_dbg(dev, "%s (%02x)\n", __func__, *buf);

    return !!(*buf);
}

static int __usbhsh_hub_hub_feature(struct usbhsh_hpriv *hpriv,
                    u16 typeReq, u16 wValue,
                    u16 wIndex, char *buf, u16 wLength)
{
    struct usbhs_priv *priv = usbhsh_hpriv_to_priv(hpriv);
    struct device *dev = usbhs_priv_to_dev(priv);

    switch (wValue) {
    case C_HUB_OVER_CURRENT:
    case C_HUB_LOCAL_POWER:
        dev_dbg(dev, "%s :: C_HUB_xx\n", __func__);
        return 0;
    }

    return -EPIPE;
}

static int __usbhsh_hub_port_feature(struct usbhsh_hpriv *hpriv,
                     u16 typeReq, u16 wValue,
                     u16 wIndex, char *buf, u16 wLength)
{
    struct usbhs_priv *priv = usbhsh_hpriv_to_priv(hpriv);
    struct device *dev = usbhs_priv_to_dev(priv);
    int enable = (typeReq == SetPortFeature);
    int speed, i, timeout = 128;
    int roothub_id = 1; /* only 1 root hub */

    /* common error */
    if (wIndex > roothub_id || wLength != 0)
        return -EPIPE;

    /* check wValue */
    switch (wValue) {
    case USB_PORT_FEAT_POWER:
        usbhs_vbus_ctrl(priv, enable);
        dev_dbg(dev, "%s :: USB_PORT_FEAT_POWER\n", __func__);
        break;

    case USB_PORT_FEAT_ENABLE:
    case USB_PORT_FEAT_SUSPEND:
    case USB_PORT_FEAT_C_ENABLE:
    case USB_PORT_FEAT_C_SUSPEND:
    case USB_PORT_FEAT_C_CONNECTION:
    case USB_PORT_FEAT_C_OVER_CURRENT:
    case USB_PORT_FEAT_C_RESET:
        dev_dbg(dev, "%s :: USB_PORT_FEAT_xxx\n", __func__);
        break;

    case USB_PORT_FEAT_RESET:
        if (!enable)
            break;

        usbhsh_port_stat_clear(hpriv,
                       USB_PORT_STAT_HIGH_SPEED |
                       USB_PORT_STAT_LOW_SPEED);

        usbhsh_queue_force_pop_all(priv);

        usbhs_bus_send_reset(priv);
        msleep(20);
        usbhs_bus_send_sof_enable(priv);

        for (i = 0; i < timeout ; i++) {
            switch (usbhs_bus_get_speed(priv)) {
            case USB_SPEED_LOW:
                speed = USB_PORT_STAT_LOW_SPEED;
                goto got_usb_bus_speed;
            case USB_SPEED_HIGH:
                speed = USB_PORT_STAT_HIGH_SPEED;
                goto got_usb_bus_speed;
            case USB_SPEED_FULL:
                speed = 0;
                goto got_usb_bus_speed;
            }

            msleep(20);
        }
        return -EPIPE;

got_usb_bus_speed:
        usbhsh_port_stat_set(hpriv, speed);
        usbhsh_port_stat_set(hpriv, USB_PORT_STAT_ENABLE);

        dev_dbg(dev, "%s :: USB_PORT_FEAT_RESET (speed = %d)\n",
            __func__, speed);

        /* status change is not needed */
        return 0;

    default:
        return -EPIPE;
    }

    /* set/clear status */
    if (enable)
        usbhsh_port_stat_set(hpriv, (1 << wValue));
    else
        usbhsh_port_stat_clear(hpriv, (1 << wValue));

    return 0;
}

static int __usbhsh_hub_get_status(struct usbhsh_hpriv *hpriv,
                   u16 typeReq, u16 wValue,
                   u16 wIndex, char *buf, u16 wLength)
{
    struct usbhs_priv *priv = usbhsh_hpriv_to_priv(hpriv);
    struct usb_hub_descriptor *desc = (struct usb_hub_descriptor *)buf;
    struct device *dev = usbhs_priv_to_dev(priv);
    int roothub_id = 1; /* only 1 root hub */

    switch (typeReq) {
    case GetHubStatus:
        dev_dbg(dev, "%s :: GetHubStatus\n", __func__);

        *buf = 0x00;
        break;

    case GetPortStatus:
        if (wIndex != roothub_id)
            return -EPIPE;

        dev_dbg(dev, "%s :: GetPortStatus\n", __func__);
        *(__le32 *)buf = cpu_to_le32(usbhsh_port_stat_get(hpriv));
        break;

    case GetHubDescriptor:
        desc->bDescriptorType       = 0x29;
        desc->bHubContrCurrent      = 0;
        desc->bNbrPorts         = roothub_id;
        desc->bDescLength       = 9;
        desc->bPwrOn2PwrGood        = 0;
        desc->wHubCharacteristics   = cpu_to_le16(0x0011);
        desc->u.hs.DeviceRemovable[0]   = (roothub_id << 1);
        desc->u.hs.DeviceRemovable[1]   = ~0;
        dev_dbg(dev, "%s :: GetHubDescriptor\n", __func__);
        break;
    }

    return 0;
}

static int usbhsh_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
                  u16 wIndex, char *buf, u16 wLength)
{
    struct usbhsh_hpriv *hpriv = usbhsh_hcd_to_hpriv(hcd);
    struct usbhs_priv *priv = usbhsh_hpriv_to_priv(hpriv);
    struct device *dev = usbhs_priv_to_dev(priv);
    int ret = -EPIPE;

    switch (typeReq) {

    /* Hub Feature */
    case ClearHubFeature:
    case SetHubFeature:
        ret = __usbhsh_hub_hub_feature(hpriv, typeReq,
                           wValue, wIndex, buf, wLength);
        break;

    /* Port Feature */
    case SetPortFeature:
    case ClearPortFeature:
        ret = __usbhsh_hub_port_feature(hpriv, typeReq,
                        wValue, wIndex, buf, wLength);
        break;

    /* Get status */
    case GetHubStatus:
    case GetPortStatus:
    case GetHubDescriptor:
        ret = __usbhsh_hub_get_status(hpriv, typeReq,
                          wValue, wIndex, buf, wLength);
        break;
    }

    dev_dbg(dev, "typeReq = %x, ret = %d, port_stat = %x\n",
        typeReq, ret, usbhsh_port_stat_get(hpriv));

    return ret;
}

static int usbhsh_bus_nop(struct usb_hcd *hcd)
{
    /* nothing to do */
    return 0;
}

static struct hc_driver usbhsh_driver = {
    .description =      usbhsh_hcd_name,
    .hcd_priv_size =    sizeof(struct usbhsh_hpriv),

    /*
     * generic hardware linkage
     */
    .flags =        HCD_USB2,

    .start =        usbhsh_host_start,
    .stop =         usbhsh_host_stop,

    /*
     * managing i/o requests and associated device resources
     */
    .urb_enqueue =      usbhsh_urb_enqueue,
    .urb_dequeue =      usbhsh_urb_dequeue,
    .endpoint_disable = usbhsh_endpoint_disable,

    /*
     * root hub
     */
    .hub_status_data =  usbhsh_hub_status_data,
    .hub_control =      usbhsh_hub_control,
    .bus_suspend =      usbhsh_bus_nop,
    .bus_resume =       usbhsh_bus_nop,
};

/*
 *      interrupt functions
 */
static int usbhsh_irq_attch(struct usbhs_priv *priv,
                struct usbhs_irq_state *irq_state)
{
    struct usbhsh_hpriv *hpriv = usbhsh_priv_to_hpriv(priv);
    struct device *dev = usbhs_priv_to_dev(priv);

    dev_dbg(dev, "device attached\n");

    usbhsh_port_stat_set(hpriv, USB_PORT_STAT_CONNECTION);
    usbhsh_port_stat_set(hpriv, USB_PORT_STAT_C_CONNECTION << 16);

    /*
     * attch interrupt might happen infinitely on some device
     * (on self power USB hub ?)
     * disable it here.
     *
     * usbhsh_is_running() becomes effective
     * according to this process.
     * see
     *  usbhsh_is_running()
     *  usbhsh_urb_enqueue()
     */
    hpriv->mod.irq_attch = NULL;
    usbhs_irq_callback_update(priv, &hpriv->mod);

    return 0;
}

static int usbhsh_irq_dtch(struct usbhs_priv *priv,
               struct usbhs_irq_state *irq_state)
{
    struct usbhsh_hpriv *hpriv = usbhsh_priv_to_hpriv(priv);
    struct device *dev = usbhs_priv_to_dev(priv);

    dev_dbg(dev, "device detached\n");

    usbhsh_port_stat_clear(hpriv, USB_PORT_STAT_CONNECTION);
    usbhsh_port_stat_set(hpriv, USB_PORT_STAT_C_CONNECTION << 16);

    /*
     * enable attch interrupt again
     *
     * usbhsh_is_running() becomes invalid
     * according to this process.
     * see
     *  usbhsh_is_running()
     *  usbhsh_urb_enqueue()
     */
    hpriv->mod.irq_attch = usbhsh_irq_attch;
    usbhs_irq_callback_update(priv, &hpriv->mod);

    /*
     * usbhsh_queue_force_pop_all() should be called
     * after usbhsh_is_running() becomes invalid.
     */
    usbhsh_queue_force_pop_all(priv);

    return 0;
}

static int usbhsh_irq_setup_ack(struct usbhs_priv *priv,
                struct usbhs_irq_state *irq_state)
{
    struct usbhsh_hpriv *hpriv = usbhsh_priv_to_hpriv(priv);
    struct device *dev = usbhs_priv_to_dev(priv);

    dev_dbg(dev, "setup packet OK\n");

    complete(&hpriv->setup_ack_done); /* see usbhsh_urb_enqueue() */

    return 0;
}

static int usbhsh_irq_setup_err(struct usbhs_priv *priv,
                struct usbhs_irq_state *irq_state)
{
    struct usbhsh_hpriv *hpriv = usbhsh_priv_to_hpriv(priv);
    struct device *dev = usbhs_priv_to_dev(priv);

    dev_dbg(dev, "setup packet Err\n");

    complete(&hpriv->setup_ack_done); /* see usbhsh_urb_enqueue() */

    return 0;
}

/*
 *      module start/stop
 */
static void usbhsh_pipe_init_for_host(struct usbhs_priv *priv)
{
    struct usbhsh_hpriv *hpriv = usbhsh_priv_to_hpriv(priv);
    struct usbhs_pipe *pipe;
    u32 *pipe_type = usbhs_get_dparam(priv, pipe_type);
    int pipe_size = usbhs_get_dparam(priv, pipe_size);
    int old_type, dir_in, i;

    /* init all pipe */
    old_type = USB_ENDPOINT_XFER_CONTROL;
    for (i = 0; i < pipe_size; i++) {

        /*
         * data "output" will be finished as soon as possible,
         * but there is no guaranty at data "input" case.
         *
         * "input" needs "standby" pipe.
         * So, "input" direction pipe > "output" direction pipe
         * is good idea.
         *
         * 1st USB_ENDPOINT_XFER_xxx will be output direction,
         * and the other will be input direction here.
         *
         * ex)
         * ...
         * USB_ENDPOINT_XFER_ISOC -> dir out
         * USB_ENDPOINT_XFER_ISOC -> dir in
         * USB_ENDPOINT_XFER_BULK -> dir out
         * USB_ENDPOINT_XFER_BULK -> dir in
         * USB_ENDPOINT_XFER_BULK -> dir in
         * ...
         */
        dir_in = (pipe_type[i] == old_type);
        old_type = pipe_type[i];

        if (USB_ENDPOINT_XFER_CONTROL == pipe_type[i]) {
            pipe = usbhs_dcp_malloc(priv);
            usbhsh_hpriv_to_dcp(hpriv) = pipe;
        } else {
            pipe = usbhs_pipe_malloc(priv,
                         pipe_type[i],
                         dir_in);
        }

        pipe->mod_private = NULL;
    }
}

static int usbhsh_start(struct usbhs_priv *priv)
{
    struct usbhsh_hpriv *hpriv = usbhsh_priv_to_hpriv(priv);
    struct usb_hcd *hcd = usbhsh_hpriv_to_hcd(hpriv);
    struct usbhs_mod *mod = usbhs_mod_get_current(priv);
    struct device *dev = usbhs_priv_to_dev(priv);
    int ret;

    /* add hcd */
    ret = usb_add_hcd(hcd, 0, 0);
    if (ret < 0)
        return 0;

    /*
     * pipe initialize and enable DCP
     */
    usbhs_pipe_init(priv,
            usbhsh_dma_map_ctrl);
    usbhs_fifo_init(priv);
    usbhsh_pipe_init_for_host(priv);

    /*
     * system config enble
     * - HI speed
     * - host
     * - usb module
     */
    usbhs_sys_host_ctrl(priv, 1);

    /*
     * enable irq callback
     */
    mod->irq_attch      = usbhsh_irq_attch;
    mod->irq_dtch       = usbhsh_irq_dtch;
    mod->irq_sack       = usbhsh_irq_setup_ack;
    mod->irq_sign       = usbhsh_irq_setup_err;
    usbhs_irq_callback_update(priv, mod);

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

    return ret;
}

static int usbhsh_stop(struct usbhs_priv *priv)
{
    struct usbhsh_hpriv *hpriv = usbhsh_priv_to_hpriv(priv);
    struct usb_hcd *hcd = usbhsh_hpriv_to_hcd(hpriv);
    struct usbhs_mod *mod = usbhs_mod_get_current(priv);
    struct device *dev = usbhs_priv_to_dev(priv);

    /*
     * disable irq callback
     */
    mod->irq_attch  = NULL;
    mod->irq_dtch   = NULL;
    mod->irq_sack   = NULL;
    mod->irq_sign   = NULL;
    usbhs_irq_callback_update(priv, mod);

    usb_remove_hcd(hcd);

    /* disable sys */
    usbhs_sys_host_ctrl(priv, 0);

    dev_dbg(dev, "quit host\n");

    return 0;
}

int usbhs_mod_host_probe(struct usbhs_priv *priv)
{
    struct usbhsh_hpriv *hpriv;
    struct usb_hcd *hcd;
    struct usbhsh_device *udev;
    struct device *dev = usbhs_priv_to_dev(priv);
    int i;

    /* initialize hcd */
    hcd = usb_create_hcd(&usbhsh_driver, dev, usbhsh_hcd_name);
    if (!hcd) {
        dev_err(dev, "Failed to create hcd\n");
        return -ENOMEM;
    }
    hcd->has_tt = 1; /* for low/full speed */

    /*
     * 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 "usbhsh_start"
     */

    hpriv = usbhsh_hcd_to_hpriv(hcd);

    /*
     * register itself
     */
    usbhs_mod_register(priv, &hpriv->mod, USBHS_HOST);

    /* init hpriv */
    hpriv->mod.name     = "host";
    hpriv->mod.start    = usbhsh_start;
    hpriv->mod.stop     = usbhsh_stop;
    usbhsh_port_stat_init(hpriv);

    /* init all device */
    usbhsh_for_each_udev_with_dev0(udev, hpriv, i) {
        udev->usbv  = NULL;
        INIT_LIST_HEAD(&udev->ep_list_head);
    }

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

    return 0;
}

int usbhs_mod_host_remove(struct usbhs_priv *priv)
{
    struct usbhsh_hpriv *hpriv = usbhsh_priv_to_hpriv(priv);
    struct usb_hcd *hcd = usbhsh_hpriv_to_hcd(hpriv);

    usb_put_hcd(hcd);

    return 0;
}