/*      $OpenBSD: ugen.c,v 1.119 2024/12/30 02:46:00 guenther Exp $ */
/*      $NetBSD: ugen.c,v 1.63 2002/11/26 18:49:48 christos Exp $       */
/*      $FreeBSD: src/sys/dev/usb/ugen.c,v 1.26 1999/11/17 22:33:41 n_hibma Exp $       */

/*
 * Copyright (c) 1998 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Lennart Augustsson (lennart@augustsson.net) at
 * Carlstedt Research & Technology.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */


#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/device.h>
#include <sys/ioctl.h>
#include <sys/conf.h>
#include <sys/tty.h>
#include <sys/fcntl.h>
#include <sys/selinfo.h>
#include <sys/vnode.h>

#include <machine/bus.h>

#include <dev/usb/usb.h>
#include <dev/usb/usbdi.h>
#include <dev/usb/usbdi_util.h>

#ifdef UGEN_DEBUG
#define DPRINTF(x)      do { if (ugendebug) printf x; } while (0)
#define DPRINTFN(n,x)   do { if (ugendebug>(n)) printf x; } while (0)
int     ugendebug = 0;
#else
#define DPRINTF(x)
#define DPRINTFN(n,x)
#endif

#define UGEN_CHUNK      128     /* chunk size for read */
#define UGEN_IBSIZE     1020    /* buffer size */
#define UGEN_BBSIZE     1024

#define UGEN_NISOFRAMES 500     /* 0.5 seconds worth */
#define UGEN_NISOREQS   6       /* number of outstanding xfer requests */
#define UGEN_NISORFRMS  4       /* number of frames (milliseconds) per req */

struct ugen_endpoint {
        struct ugen_softc *sc;
        usb_endpoint_descriptor_t *edesc;
        struct usbd_interface *iface;
        int state;
#define UGEN_ASLP       0x02    /* waiting for data */
#define UGEN_SHORT_OK   0x04    /* short xfers are OK */
        struct usbd_pipe *pipeh;
        struct clist q;
        struct selinfo rsel;
        u_char *ibuf;           /* start of buffer (circular for isoc) */
        size_t  ibuflen;
        u_char *fill;           /* location for input (isoc) */
        u_char *limit;          /* end of circular buffer (isoc) */
        u_char *cur;            /* current read location (isoc) */
        u_int32_t timeout;
        struct isoreq {
                struct ugen_endpoint *sce;
                struct usbd_xfer *xfer;
                void *dmabuf;
                u_int16_t sizes[UGEN_NISORFRMS];
        } isoreqs[UGEN_NISOREQS];
};

struct ugen_softc {
        struct device sc_dev;           /* base device */
        struct usbd_device *sc_udev;

        char sc_is_open[USB_MAX_ENDPOINTS];
        struct ugen_endpoint sc_endpoints[USB_MAX_ENDPOINTS][2];
#define OUT 0
#define IN  1

        int sc_refcnt;
        u_char sc_secondary;
};

void ugenintr(struct usbd_xfer *, void *, usbd_status);
void ugen_isoc_rintr(struct usbd_xfer *, void *, usbd_status);
int ugen_do_read(struct ugen_softc *, int, struct uio *, int);
int ugen_do_write(struct ugen_softc *, int, struct uio *, int);
int ugen_do_ioctl(struct ugen_softc *, int, u_long, caddr_t, int,
        struct proc *);
int ugen_do_close(struct ugen_softc *, int, int);
int ugen_set_config(struct ugen_softc *, int);
int ugen_set_interface(struct ugen_softc *, int, int);
int ugen_get_alt_index(struct ugen_softc *, int);
void ugen_clear_iface_eps(struct ugen_softc *, struct usbd_interface *);

#define UGENUNIT(n) ((minor(n) >> 4) & 0xf)
#define UGENENDPOINT(n) (minor(n) & 0xf)
#define UGENDEV(u, e) (makedev(0, ((u) << 4) | (e)))

int ugen_match(struct device *, void *, void *);
void ugen_attach(struct device *, struct device *, void *);
int ugen_detach(struct device *, int);

struct cfdriver ugen_cd = {
        NULL, "ugen", DV_DULL
};

const struct cfattach ugen_ca = {
        sizeof(struct ugen_softc), ugen_match, ugen_attach, ugen_detach
};

int
ugen_match(struct device *parent, void *match, void *aux)
{
        struct usb_attach_arg *uaa = aux;

        if (uaa->usegeneric) {
                return (UMATCH_GENERIC);
        } else
                return (UMATCH_NONE);
}

void
ugen_attach(struct device *parent, struct device *self, void *aux)
{
        struct ugen_softc *sc = (struct ugen_softc *)self;
        struct usb_attach_arg *uaa = aux;
        struct usbd_device *udev;
        usbd_status err;
        int conf;

        sc->sc_udev = udev = uaa->device;

        if (usbd_get_devcnt(udev) > 0)
                sc->sc_secondary = 1;

        if (!sc->sc_secondary) {
                /* First set configuration index 0, the default one for ugen. */
                err = usbd_set_config_index(udev, 0, 0);
                if (err) {
                        printf("%s: setting configuration index 0 failed\n",
                               sc->sc_dev.dv_xname);
                        usbd_deactivate(sc->sc_udev);
                        return;
                }
        }
        conf = usbd_get_config_descriptor(udev)->bConfigurationValue;

        /* Set up all the local state for this configuration. */
        err = ugen_set_config(sc, conf);
        if (err) {
                printf("%s: setting configuration %d failed\n",
                       sc->sc_dev.dv_xname, conf);
                usbd_deactivate(sc->sc_udev);
                return;
        }
}

int
ugen_set_config(struct ugen_softc *sc, int configno)
{
        struct usbd_device *dev = sc->sc_udev;
        usb_config_descriptor_t *cdesc;
        usb_interface_descriptor_t *id;
        struct usbd_interface *iface;
        usb_endpoint_descriptor_t *ed;
        struct ugen_endpoint *sce;
        int ifaceno, endptno, endpt;
        int err, dir;

        DPRINTFN(1,("ugen_set_config: %s to configno %d, sc=%p\n",
                    sc->sc_dev.dv_xname, configno, sc));

        /*
         * We start at 1, not 0, because we don't care whether the
         * control endpoint is open or not. It is always present.
         */
        for (endptno = 1; endptno < USB_MAX_ENDPOINTS; endptno++)
                if (sc->sc_is_open[endptno]) {
                        DPRINTFN(1,
                             ("ugen_set_config: %s - endpoint %d is open\n",
                              sc->sc_dev.dv_xname, endptno));
                        return (USBD_IN_USE);
                }

        /* Avoid setting the current value. */
        cdesc = usbd_get_config_descriptor(dev);
        if (cdesc == NULL || cdesc->bConfigurationValue != configno) {
                if (sc->sc_secondary) {
                        printf("%s: secondary, not changing config to %d\n",
                            __func__, configno);
                        return (USBD_IN_USE);
                } else {
                        err = usbd_set_config_no(dev, configno, 1);
                        if (err)
                                return (err);
                        cdesc = usbd_get_config_descriptor(dev);
                        if (cdesc == NULL ||
                            cdesc->bConfigurationValue != configno)
                                return (USBD_INVAL);
                }
        }

        memset(sc->sc_endpoints, 0, sizeof sc->sc_endpoints);
        for (ifaceno = 0; ifaceno < cdesc->bNumInterfaces; ifaceno++) {
                DPRINTFN(1,("ugen_set_config: ifaceno %d\n", ifaceno));
                if (usbd_iface_claimed(sc->sc_udev, ifaceno)) {
                        DPRINTF(("%s: iface %d not available\n", __func__,
                            ifaceno));
                        continue;
                }
                err = usbd_device2interface_handle(dev, ifaceno, &iface);
                if (err)
                        return (err);
                id = usbd_get_interface_descriptor(iface);
                for (endptno = 0; endptno < id->bNumEndpoints; endptno++) {
                        ed = usbd_interface2endpoint_descriptor(iface,endptno);
                        endpt = ed->bEndpointAddress;
                        dir = UE_GET_DIR(endpt) == UE_DIR_IN ? IN : OUT;
                        sce = &sc->sc_endpoints[UE_GET_ADDR(endpt)][dir];
                        DPRINTFN(1,("ugen_set_config: endptno %d, endpt=0x%02x"
                                    "(%d,%d), sce=%p\n",
                                    endptno, endpt, UE_GET_ADDR(endpt),
                                    UE_GET_DIR(endpt), sce));
                        sce->sc = sc;
                        sce->edesc = ed;
                        sce->iface = iface;
                }
        }
        return (0);
}

int
ugenopen(dev_t dev, int flag, int mode, struct proc *p)
{
        struct ugen_softc *sc;
        int unit = UGENUNIT(dev);
        int endpt = UGENENDPOINT(dev);
        usb_endpoint_descriptor_t *edesc;
        struct ugen_endpoint *sce;
        int dir, isize;
        usbd_status err;
        struct usbd_xfer *xfer;
        void *buf;
        int i, j;

        if (unit >= ugen_cd.cd_ndevs)
                return (ENXIO);
        sc = ugen_cd.cd_devs[unit];
        if (sc == NULL)
                return (ENXIO);

        DPRINTFN(5, ("ugenopen: flag=%d, mode=%d, unit=%d endpt=%d\n",
                     flag, mode, unit, endpt));

        if (sc == NULL || usbd_is_dying(sc->sc_udev))
                return (ENXIO);

        if (sc->sc_is_open[endpt])
                return (EBUSY);

        if (endpt == USB_CONTROL_ENDPOINT) {
                sc->sc_is_open[USB_CONTROL_ENDPOINT] = 1;
                return (0);
        }

        /* Make sure there are pipes for all directions. */
        for (dir = OUT; dir <= IN; dir++) {
                if (flag & (dir == OUT ? FWRITE : FREAD)) {
                        sce = &sc->sc_endpoints[endpt][dir];
                        if (sce == 0 || sce->edesc == 0)
                                return (ENXIO);
                }
        }

        /* Actually open the pipes. */
        /* XXX Should back out properly if it fails. */
        for (dir = OUT; dir <= IN; dir++) {
                if (!(flag & (dir == OUT ? FWRITE : FREAD)))
                        continue;
                sce = &sc->sc_endpoints[endpt][dir];
                sce->state = 0;
                sce->timeout = USBD_NO_TIMEOUT;
                DPRINTFN(5, ("ugenopen: sc=%p, endpt=%d, dir=%d, sce=%p\n",
                             sc, endpt, dir, sce));
                edesc = sce->edesc;
                /* Clear device endpoint toggle. */
                ugen_clear_iface_eps(sc, sce->iface);
                switch (UE_GET_XFERTYPE(edesc->bmAttributes)) {
                case UE_INTERRUPT:
                        if (dir == OUT) {
                                err = usbd_open_pipe(sce->iface,
                                    edesc->bEndpointAddress, 0, &sce->pipeh);
                                if (err)
                                        return (EIO);
                                break;
                        }
                        isize = UGETW(edesc->wMaxPacketSize);
                        if (isize == 0) /* shouldn't happen */
                                return (EINVAL);
                        sce->ibuflen = isize;
                        sce->ibuf = malloc(sce->ibuflen, M_USBDEV, M_WAITOK);
                        DPRINTFN(5, ("ugenopen: intr endpt=%d,isize=%d\n",
                                     endpt, isize));
                        clalloc(&sce->q, UGEN_IBSIZE, 0);
                        err = usbd_open_pipe_intr(sce->iface,
                                  edesc->bEndpointAddress,
                                  USBD_SHORT_XFER_OK, &sce->pipeh, sce,
                                  sce->ibuf, isize, ugenintr,
                                  USBD_DEFAULT_INTERVAL);
                        if (err) {
                                free(sce->ibuf, M_USBDEV, sce->ibuflen);
                                clfree(&sce->q);
                                return (EIO);
                        }
                        /* Clear HC endpoint toggle. */
                        usbd_clear_endpoint_toggle(sce->pipeh);
                        DPRINTFN(5, ("ugenopen: interrupt open done\n"));
                        break;
                case UE_BULK:
                        err = usbd_open_pipe(sce->iface,
                                  edesc->bEndpointAddress, 0, &sce->pipeh);
                        if (err)
                                return (EIO);
                        /* Clear HC endpoint toggle. */
                        usbd_clear_endpoint_toggle(sce->pipeh);
                        break;
                case UE_ISOCHRONOUS:
                        if (dir == OUT)
                                return (EINVAL);
                        isize = UGETW(edesc->wMaxPacketSize);
                        if (isize == 0) /* shouldn't happen */
                                return (EINVAL);
                        sce->ibuflen = isize * UGEN_NISOFRAMES;
                        sce->ibuf = mallocarray(isize, UGEN_NISOFRAMES,
                                M_USBDEV, M_WAITOK);
                        sce->cur = sce->fill = sce->ibuf;
                        sce->limit = sce->ibuf + isize * UGEN_NISOFRAMES;
                        DPRINTFN(5, ("ugenopen: isoc endpt=%d, isize=%d\n",
                                     endpt, isize));
                        err = usbd_open_pipe(sce->iface,
                                  edesc->bEndpointAddress, 0, &sce->pipeh);
                        if (err) {
                                free(sce->ibuf, M_USBDEV, sce->ibuflen);
                                return (EIO);
                        }
                        for(i = 0; i < UGEN_NISOREQS; ++i) {
                                sce->isoreqs[i].sce = sce;
                                xfer = usbd_alloc_xfer(sc->sc_udev);
                                if (xfer == 0)
                                        goto bad;
                                sce->isoreqs[i].xfer = xfer;
                                buf = usbd_alloc_buffer
                                        (xfer, isize * UGEN_NISORFRMS);
                                if (buf == 0) {
                                        i++;
                                        goto bad;
                                }
                                sce->isoreqs[i].dmabuf = buf;
                                for(j = 0; j < UGEN_NISORFRMS; ++j)
                                        sce->isoreqs[i].sizes[j] = isize;
                                usbd_setup_isoc_xfer(xfer, sce->pipeh,
                                    &sce->isoreqs[i], sce->isoreqs[i].sizes,
                                    UGEN_NISORFRMS, USBD_NO_COPY |
                                    USBD_SHORT_XFER_OK, ugen_isoc_rintr);
                                (void)usbd_transfer(xfer);
                        }
                        DPRINTFN(5, ("ugenopen: isoc open done\n"));
                        break;
                bad:
                        while (--i >= 0) /* implicit buffer free */
                                usbd_free_xfer(sce->isoreqs[i].xfer);
                        return (ENOMEM);
                case UE_CONTROL:
                        sce->timeout = USBD_DEFAULT_TIMEOUT;
                        return (EINVAL);
                }
        }
        sc->sc_is_open[endpt] = 1;
        return (0);
}

int
ugenclose(dev_t dev, int flag, int mode, struct proc *p)
{
        struct ugen_softc *sc = ugen_cd.cd_devs[UGENUNIT(dev)];
        int endpt = UGENENDPOINT(dev);
        int error;

        if (sc == NULL || usbd_is_dying(sc->sc_udev))
                return (EIO);

        DPRINTFN(5, ("ugenclose: flag=%d, mode=%d, unit=%d, endpt=%d\n",
                     flag, mode, UGENUNIT(dev), endpt));

        sc->sc_refcnt++;
        error = ugen_do_close(sc, endpt, flag);
        if (--sc->sc_refcnt < 0)
                usb_detach_wakeup(&sc->sc_dev);

        return (error);
}

int
ugen_do_close(struct ugen_softc *sc, int endpt, int flag)
{
        struct ugen_endpoint *sce;
        int dir, i;

#ifdef DIAGNOSTIC
        if (!sc->sc_is_open[endpt]) {
                printf("ugenclose: not open\n");
                return (EINVAL);
        }
#endif

        if (endpt == USB_CONTROL_ENDPOINT) {
                DPRINTFN(5, ("ugenclose: close control\n"));
                sc->sc_is_open[endpt] = 0;
                return (0);
        }

        for (dir = OUT; dir <= IN; dir++) {
                if (!(flag & (dir == OUT ? FWRITE : FREAD)))
                        continue;
                sce = &sc->sc_endpoints[endpt][dir];
                if (sce == NULL || sce->pipeh == NULL)
                        continue;
                DPRINTFN(5, ("ugenclose: endpt=%d dir=%d sce=%p\n",
                             endpt, dir, sce));

                usbd_close_pipe(sce->pipeh);
                sce->pipeh = NULL;

                switch (UE_GET_XFERTYPE(sce->edesc->bmAttributes)) {
                case UE_INTERRUPT:
                        ndflush(&sce->q, sce->q.c_cc);
                        clfree(&sce->q);
                        break;
                case UE_ISOCHRONOUS:
                        for (i = 0; i < UGEN_NISOREQS; ++i)
                                usbd_free_xfer(sce->isoreqs[i].xfer);

                default:
                        break;
                }

                if (sce->ibuf != NULL) {
                        free(sce->ibuf, M_USBDEV, sce->ibuflen);
                        sce->ibuf = NULL;
                }
        }
        sc->sc_is_open[endpt] = 0;

        return (0);
}

int
ugen_do_read(struct ugen_softc *sc, int endpt, struct uio *uio, int flag)
{
        struct ugen_endpoint *sce = &sc->sc_endpoints[endpt][IN];
        u_int32_t tn;
        size_t n;
        char buf[UGEN_BBSIZE];
        struct usbd_xfer *xfer;
        usbd_status err;
        int s;
        int flags, error = 0;
        u_char buffer[UGEN_CHUNK];

        DPRINTFN(5, ("%s: ugenread: %d\n", sc->sc_dev.dv_xname, endpt));

        if (usbd_is_dying(sc->sc_udev))
                return (EIO);

        if (endpt == USB_CONTROL_ENDPOINT)
                return (ENODEV);

#ifdef DIAGNOSTIC
        if (sce->edesc == NULL) {
                printf("ugenread: no edesc\n");
                return (EIO);
        }
        if (sce->pipeh == NULL) {
                printf("ugenread: no pipe\n");
                return (EIO);
        }
#endif

        switch (UE_GET_XFERTYPE(sce->edesc->bmAttributes)) {
        case UE_INTERRUPT:
                /* Block until activity occurred. */
                s = splusb();
                while (sce->q.c_cc == 0) {
                        if (flag & IO_NDELAY) {
                                splx(s);
                                return (EWOULDBLOCK);
                        }
                        sce->state |= UGEN_ASLP;
                        DPRINTFN(5, ("ugenread: sleep on %p\n", sce));
                        error = tsleep_nsec(sce, PZERO | PCATCH, "ugenrintr",
                            MSEC_TO_NSEC(sce->timeout));
                        sce->state &= ~UGEN_ASLP;
                        DPRINTFN(5, ("ugenread: woke, error=%d\n", error));
                        if (usbd_is_dying(sc->sc_udev))
                                error = EIO;
                        if (error == EWOULDBLOCK) {     /* timeout, return 0 */
                                error = 0;
                                break;
                        }
                        if (error)
                                break;
                }
                splx(s);

                /* Transfer as many chunks as possible. */
                while (sce->q.c_cc > 0 && uio->uio_resid > 0 && !error) {
                        n = ulmin(sce->q.c_cc, uio->uio_resid);
                        if (n > sizeof(buffer))
                                n = sizeof(buffer);

                        /* Remove a small chunk from the input queue. */
                        q_to_b(&sce->q, buffer, n);
                        DPRINTFN(5, ("ugenread: got %zu chars\n", n));

                        /* Copy the data to the user process. */
                        error = uiomove(buffer, n, uio);
                        if (error)
                                break;
                }
                break;
        case UE_BULK:
                xfer = usbd_alloc_xfer(sc->sc_udev);
                if (xfer == 0)
                        return (ENOMEM);
                flags = USBD_SYNCHRONOUS;
                if (sce->state & UGEN_SHORT_OK)
                        flags |= USBD_SHORT_XFER_OK;
                if (sce->timeout == 0)
                        flags |= USBD_CATCH;
                while ((n = ulmin(UGEN_BBSIZE, uio->uio_resid)) != 0) {
                        DPRINTFN(1, ("ugenread: start transfer %zu bytes\n",n));
                        usbd_setup_xfer(xfer, sce->pipeh, 0, buf, n,
                            flags, sce->timeout, NULL);
                        err = usbd_transfer(xfer);
                        if (err) {
                                usbd_clear_endpoint_stall(sce->pipeh);
                                if (err == USBD_INTERRUPTED)
                                        error = EINTR;
                                else if (err == USBD_TIMEOUT)
                                        error = ETIMEDOUT;
                                else
                                        error = EIO;
                                break;
                        }
                        usbd_get_xfer_status(xfer, NULL, NULL, &tn, NULL);
                        DPRINTFN(1, ("ugenread: got %u bytes\n", tn));
                        error = uiomove(buf, tn, uio);
                        if (error || tn < n)
                                break;
                }
                usbd_free_xfer(xfer);
                break;
        case UE_ISOCHRONOUS:
                s = splusb();
                while (sce->cur == sce->fill) {
                        if (flag & IO_NDELAY) {
                                splx(s);
                                return (EWOULDBLOCK);
                        }
                        sce->state |= UGEN_ASLP;
                        DPRINTFN(5, ("ugenread: sleep on %p\n", sce));
                        error = tsleep_nsec(sce, PZERO | PCATCH, "ugenriso",
                            MSEC_TO_NSEC(sce->timeout));
                        sce->state &= ~UGEN_ASLP;
                        DPRINTFN(5, ("ugenread: woke, error=%d\n", error));
                        if (usbd_is_dying(sc->sc_udev))
                                error = EIO;
                        if (error == EWOULDBLOCK) {     /* timeout, return 0 */
                                error = 0;
                                break;
                        }
                        if (error)
                                break;
                }

                while (sce->cur != sce->fill && uio->uio_resid > 0 && !error) {
                        if(sce->fill > sce->cur)
                                n = ulmin(sce->fill - sce->cur, uio->uio_resid);
                        else
                                n = ulmin(sce->limit - sce->cur, uio->uio_resid);

                        DPRINTFN(5, ("ugenread: isoc got %zu chars\n", n));

                        /* Copy the data to the user process. */
                        error = uiomove(sce->cur, n, uio);
                        if (error)
                                break;
                        sce->cur += n;
                        if(sce->cur >= sce->limit)
                                sce->cur = sce->ibuf;
                }
                splx(s);
                break;


        default:
                return (ENXIO);
        }
        return (error);
}

int
ugenread(dev_t dev, struct uio *uio, int flag)
{
        int endpt = UGENENDPOINT(dev);
        struct ugen_softc *sc;
        int error;

        sc = ugen_cd.cd_devs[UGENUNIT(dev)];

        sc->sc_refcnt++;
        error = ugen_do_read(sc, endpt, uio, flag);
        if (--sc->sc_refcnt < 0)
                usb_detach_wakeup(&sc->sc_dev);
        return (error);
}

int
ugen_do_write(struct ugen_softc *sc, int endpt, struct uio *uio, int flag)
{
        struct ugen_endpoint *sce = &sc->sc_endpoints[endpt][OUT];
        size_t n;
        int flags, error = 0;
        char buf[UGEN_BBSIZE];
        struct usbd_xfer *xfer;
        usbd_status err;

        DPRINTFN(5, ("%s: ugenwrite: %d\n", sc->sc_dev.dv_xname, endpt));

        if (usbd_is_dying(sc->sc_udev))
                return (EIO);

        if (endpt == USB_CONTROL_ENDPOINT)
                return (ENODEV);

#ifdef DIAGNOSTIC
        if (sce->edesc == NULL) {
                printf("ugenwrite: no edesc\n");
                return (EIO);
        }
        if (sce->pipeh == NULL) {
                printf("ugenwrite: no pipe\n");
                return (EIO);
        }
#endif
        flags = USBD_SYNCHRONOUS;
        if (sce->timeout == 0)
                flags |= USBD_CATCH;

        switch (UE_GET_XFERTYPE(sce->edesc->bmAttributes)) {
        case UE_BULK:
                xfer = usbd_alloc_xfer(sc->sc_udev);
                if (xfer == 0)
                        return (EIO);
                while ((n = ulmin(UGEN_BBSIZE, uio->uio_resid)) != 0) {
                        error = uiomove(buf, n, uio);
                        if (error)
                                break;
                        DPRINTFN(1, ("ugenwrite: transfer %zu bytes\n", n));
                        usbd_setup_xfer(xfer, sce->pipeh, 0, buf, n,
                            flags, sce->timeout, NULL);
                        err = usbd_transfer(xfer);
                        if (err) {
                                usbd_clear_endpoint_stall(sce->pipeh);
                                if (err == USBD_INTERRUPTED)
                                        error = EINTR;
                                else if (err == USBD_TIMEOUT)
                                        error = ETIMEDOUT;
                                else
                                        error = EIO;
                                break;
                        }
                }
                usbd_free_xfer(xfer);
                break;
        case UE_INTERRUPT:
                xfer = usbd_alloc_xfer(sc->sc_udev);
                if (xfer == 0)
                        return (EIO);
                while ((n = ulmin(UGETW(sce->edesc->wMaxPacketSize),
                    uio->uio_resid)) != 0) {
                        error = uiomove(buf, n, uio);
                        if (error)
                                break;
                        DPRINTFN(1, ("ugenwrite: transfer %zu bytes\n", n));
                        usbd_setup_xfer(xfer, sce->pipeh, 0, buf, n,
                            flags, sce->timeout, NULL);
                        err = usbd_transfer(xfer);
                        if (err) {
                                usbd_clear_endpoint_stall(sce->pipeh);
                                if (err == USBD_INTERRUPTED)
                                        error = EINTR;
                                else if (err == USBD_TIMEOUT)
                                        error = ETIMEDOUT;
                                else
                                        error = EIO;
                                break;
                        }
                }
                usbd_free_xfer(xfer);
                break;
        default:
                return (ENXIO);
        }
        return (error);
}

int
ugenwrite(dev_t dev, struct uio *uio, int flag)
{
        int endpt = UGENENDPOINT(dev);
        struct ugen_softc *sc;
        int error;

        sc = ugen_cd.cd_devs[UGENUNIT(dev)];

        sc->sc_refcnt++;
        error = ugen_do_write(sc, endpt, uio, flag);
        if (--sc->sc_refcnt < 0)
                usb_detach_wakeup(&sc->sc_dev);
        return (error);
}

int
ugen_detach(struct device *self, int flags)
{
        struct ugen_softc *sc = (struct ugen_softc *)self;
        struct ugen_endpoint *sce;
        int i, dir, endptno;
        int s, maj, mn;

        DPRINTF(("ugen_detach: sc=%p flags=%d\n", sc, flags));

        /* Abort all pipes.  Causes processes waiting for transfer to wake. */
        for (i = 0; i < USB_MAX_ENDPOINTS; i++) {
                for (dir = OUT; dir <= IN; dir++) {
                        sce = &sc->sc_endpoints[i][dir];
                        if (sce && sce->pipeh)
                                usbd_abort_pipe(sce->pipeh);
                }
        }

        s = splusb();
        if (--sc->sc_refcnt >= 0) {
                /* Wake everyone */
                for (i = 0; i < USB_MAX_ENDPOINTS; i++)
                        wakeup(&sc->sc_endpoints[i][IN]);
                /* Wait for processes to go away. */
                usb_detach_wait(&sc->sc_dev);
        }
        splx(s);

        /* locate the major number */
        for (maj = 0; maj < nchrdev; maj++)
                if (cdevsw[maj].d_open == ugenopen)
                        break;

        /* Nuke the vnodes for any open instances (calls close). */
        mn = self->dv_unit * USB_MAX_ENDPOINTS;
        vdevgone(maj, mn, mn + USB_MAX_ENDPOINTS - 1, VCHR);

        for (endptno = 0; endptno < USB_MAX_ENDPOINTS; endptno++) {
                if (sc->sc_is_open[endptno])
                        ugen_do_close(sc, endptno, FREAD|FWRITE);

                /* ugenkqfilter() always uses IN. */
                sce = &sc->sc_endpoints[endptno][IN];
                klist_invalidate(&sce->rsel.si_note);
        }
        return (0);
}

void
ugenintr(struct usbd_xfer *xfer, void *addr, usbd_status status)
{
        struct ugen_endpoint *sce = addr;
        /*struct ugen_softc *sc = sce->sc;*/
        u_int32_t count;
        u_char *ibuf;

        if (status == USBD_CANCELLED)
                return;

        if (status != USBD_NORMAL_COMPLETION) {
                DPRINTF(("ugenintr: status=%d\n", status));
                if (status == USBD_STALLED)
                        usbd_clear_endpoint_stall_async(sce->pipeh);
                return;
        }

        usbd_get_xfer_status(xfer, NULL, NULL, &count, NULL);
        ibuf = sce->ibuf;

        DPRINTFN(5, ("ugenintr: xfer=%p status=%d count=%d\n",
                     xfer, status, count));
        DPRINTFN(5, ("          data = %02x %02x %02x\n",
                     ibuf[0], ibuf[1], ibuf[2]));

        (void)b_to_q(ibuf, count, &sce->q);

        if (sce->state & UGEN_ASLP) {
                sce->state &= ~UGEN_ASLP;
                DPRINTFN(5, ("ugen_intr: waking %p\n", sce));
                wakeup(sce);
        }
        selwakeup(&sce->rsel);
}

void
ugen_isoc_rintr(struct usbd_xfer *xfer, void *addr, usbd_status status)
{
        struct isoreq *req = addr;
        struct ugen_endpoint *sce = req->sce;
        u_int32_t count, n;
        int i, isize;

        /* Return if we are aborting. */
        if (status == USBD_CANCELLED)
                return;

        usbd_get_xfer_status(xfer, NULL, NULL, &count, NULL);
        DPRINTFN(5,("%s: xfer %ld, count=%d\n", __func__, req - sce->isoreqs,
            count));

        /* throw away oldest input if the buffer is full */
        if(sce->fill < sce->cur && sce->cur <= sce->fill + count) {
                sce->cur += count;
                if(sce->cur >= sce->limit)
                        sce->cur = sce->ibuf + (sce->limit - sce->cur);
                DPRINTFN(5, ("%s: throwing away %d bytes\n", __func__, count));
        }

        isize = UGETW(sce->edesc->wMaxPacketSize);
        for (i = 0; i < UGEN_NISORFRMS; i++) {
                u_int32_t actlen = req->sizes[i];
                char const *buf = (char const *)req->dmabuf + isize * i;

                /* copy data to buffer */
                while (actlen > 0) {
                        n = min(actlen, sce->limit - sce->fill);
                        memcpy(sce->fill, buf, n);

                        buf += n;
                        actlen -= n;
                        sce->fill += n;
                        if(sce->fill == sce->limit)
                                sce->fill = sce->ibuf;
                }

                /* setup size for next transfer */
                req->sizes[i] = isize;
        }

        usbd_setup_isoc_xfer(xfer, sce->pipeh, req, req->sizes, UGEN_NISORFRMS,
            USBD_NO_COPY | USBD_SHORT_XFER_OK, ugen_isoc_rintr);
        (void)usbd_transfer(xfer);

        if (sce->state & UGEN_ASLP) {
                sce->state &= ~UGEN_ASLP;
                DPRINTFN(5, ("ugen_isoc_rintr: waking %p\n", sce));
                wakeup(sce);
        }
        selwakeup(&sce->rsel);
}

int 
ugen_set_interface(struct ugen_softc *sc, int ifaceno, int altno)
{
        struct usbd_interface *iface;
        usb_config_descriptor_t *cdesc;
        usb_interface_descriptor_t *id;
        usb_endpoint_descriptor_t *ed;
        struct ugen_endpoint *sce;
        uint8_t  endptno, endpt;
        int dir, err;

        DPRINTFN(15, ("ugen_set_interface %d %d\n", ifaceno, altno));

        cdesc = usbd_get_config_descriptor(sc->sc_udev);
        if (ifaceno < 0 || ifaceno >= cdesc->bNumInterfaces ||
            usbd_iface_claimed(sc->sc_udev, ifaceno))
                return (USBD_INVAL);

        err = usbd_device2interface_handle(sc->sc_udev, ifaceno, &iface);
        if (err)
                return (err);
        id = usbd_get_interface_descriptor(iface);
        for (endptno = 0; endptno < id->bNumEndpoints; endptno++) {
                ed = usbd_interface2endpoint_descriptor(iface,endptno);
                endpt = ed->bEndpointAddress;
                dir = UE_GET_DIR(endpt) == UE_DIR_IN ? IN : OUT;
                sce = &sc->sc_endpoints[UE_GET_ADDR(endpt)][dir];
                sce->sc = 0;
                sce->edesc = 0;
                sce->iface = 0;
        }

        /* Try to change setting, if this fails put back the descriptors. */
        err = usbd_set_interface(iface, altno);

        id = usbd_get_interface_descriptor(iface);
        for (endptno = 0; endptno < id->bNumEndpoints; endptno++) {
                ed = usbd_interface2endpoint_descriptor(iface,endptno);
                endpt = ed->bEndpointAddress;
                dir = UE_GET_DIR(endpt) == UE_DIR_IN ? IN : OUT;
                sce = &sc->sc_endpoints[UE_GET_ADDR(endpt)][dir];
                sce->sc = sc;
                sce->edesc = ed;
                sce->iface = iface;
        }
        return (err);
}

int
ugen_get_alt_index(struct ugen_softc *sc, int ifaceno)
{
        struct usbd_interface *iface;
        usbd_status err;

        err = usbd_device2interface_handle(sc->sc_udev, ifaceno, &iface);
        if (err)
                return (-1);
        return (usbd_get_interface_altindex(iface));
}

int
ugen_do_ioctl(struct ugen_softc *sc, int endpt, u_long cmd, caddr_t addr,
    int flag, struct proc *p)
{
        struct ugen_endpoint *sce;
        int err, cdesc_len;
        struct usbd_interface *iface;
        struct usb_config_desc *cd;
        usb_config_descriptor_t *cdesc;
        struct usb_interface_desc *id;
        usb_interface_descriptor_t *idesc;
        struct usb_endpoint_desc *ed;
        usb_endpoint_descriptor_t *edesc;
        struct usb_alt_interface *ai;
        u_int8_t conf, alt;

        DPRINTFN(5, ("ugenioctl: cmd=%08lx\n", cmd));
        if (usbd_is_dying(sc->sc_udev))
                return (EIO);

        switch (cmd) {
        case USB_SET_SHORT_XFER:
                if (endpt == USB_CONTROL_ENDPOINT)
                        return (EINVAL);
                /* This flag only affects read */
                sce = &sc->sc_endpoints[endpt][IN];
                if (sce == NULL || sce->pipeh == NULL)
                        return (EINVAL);
                if (*(int *)addr)
                        sce->state |= UGEN_SHORT_OK;
                else
                        sce->state &= ~UGEN_SHORT_OK;
                return (0);
        case USB_SET_TIMEOUT:
                sce = &sc->sc_endpoints[endpt][IN];
                if (sce == NULL)
                        return (EINVAL);
                sce->timeout = *(int *)addr;
                sce = &sc->sc_endpoints[endpt][OUT];
                if (sce == NULL)
                        return (EINVAL);
                sce->timeout = *(int *)addr;
                return (0);
        default:
                break;
        }

        if (endpt != USB_CONTROL_ENDPOINT)
                return (EINVAL);

        switch (cmd) {
#ifdef UGEN_DEBUG
        case USB_SETDEBUG:
                ugendebug = *(int *)addr;
                break;
#endif
        case USB_GET_CONFIG:
                err = usbd_get_config(sc->sc_udev, &conf);
                if (err)
                        return (EIO);
                *(int *)addr = conf;
                break;
        case USB_SET_CONFIG:
                if (!(flag & FWRITE))
                        return (EPERM);
                err = ugen_set_config(sc, *(int *)addr);
                switch (err) {
                case USBD_NORMAL_COMPLETION:
                        break;
                case USBD_IN_USE:
                        return (EBUSY);
                default:
                        return (EIO);
                }
                break;
        case USB_GET_ALTINTERFACE:
                ai = (struct usb_alt_interface *)addr;
                err = usbd_device2interface_handle(sc->sc_udev,
                          ai->uai_interface_index, &iface);
                if (err)
                        return (EINVAL);
                idesc = usbd_get_interface_descriptor(iface);
                if (idesc == NULL)
                        return (EIO);
                ai->uai_alt_no = idesc->bAlternateSetting;
                break;
        case USB_SET_ALTINTERFACE:
                if (!(flag & FWRITE))
                        return (EPERM);
                ai = (struct usb_alt_interface *)addr;
                err = usbd_device2interface_handle(sc->sc_udev,
                          ai->uai_interface_index, &iface);
                if (err)
                        return (EINVAL);
                err = ugen_set_interface(sc, ai->uai_interface_index,
                    ai->uai_alt_no);
                if (err)
                        return (EINVAL);
                break;
        case USB_GET_NO_ALT:
                ai = (struct usb_alt_interface *)addr;
                cdesc = usbd_get_cdesc(sc->sc_udev, ai->uai_config_index,
                    &cdesc_len);
                if (cdesc == NULL)
                        return (EINVAL);
                idesc = usbd_find_idesc(cdesc, ai->uai_interface_index, 0);
                if (idesc == NULL) {
                        free(cdesc, M_TEMP, UGETW(cdesc->wTotalLength));
                        return (EINVAL);
                }
                ai->uai_alt_no = usbd_get_no_alts(cdesc,
                    idesc->bInterfaceNumber);
                free(cdesc, M_TEMP, cdesc_len);
                break;
        case USB_GET_DEVICE_DESC:
                *(usb_device_descriptor_t *)addr =
                        *usbd_get_device_descriptor(sc->sc_udev);
                break;
        case USB_GET_CONFIG_DESC:
                cd = (struct usb_config_desc *)addr;
                cdesc = usbd_get_cdesc(sc->sc_udev, cd->ucd_config_index,
                    &cdesc_len);
                if (cdesc == NULL)
                        return (EINVAL);
                cd->ucd_desc = *cdesc;
                free(cdesc, M_TEMP, cdesc_len);
                break;
        case USB_GET_INTERFACE_DESC:
                id = (struct usb_interface_desc *)addr;
                cdesc = usbd_get_cdesc(sc->sc_udev, id->uid_config_index,
                    &cdesc_len);
                if (cdesc == NULL)
                        return (EINVAL);
                if (id->uid_config_index == USB_CURRENT_CONFIG_INDEX &&
                    id->uid_alt_index == USB_CURRENT_ALT_INDEX)
                        alt = ugen_get_alt_index(sc, id->uid_interface_index);
                else
                        alt = id->uid_alt_index;
                idesc = usbd_find_idesc(cdesc, id->uid_interface_index, alt);
                if (idesc == NULL) {
                        free(cdesc, M_TEMP, UGETW(cdesc->wTotalLength));
                        return (EINVAL);
                }
                id->uid_desc = *idesc;
                free(cdesc, M_TEMP, cdesc_len);
                break;
        case USB_GET_ENDPOINT_DESC:
                ed = (struct usb_endpoint_desc *)addr;
                cdesc = usbd_get_cdesc(sc->sc_udev, ed->ued_config_index,
                    &cdesc_len);
                if (cdesc == NULL)
                        return (EINVAL);
                if (ed->ued_config_index == USB_CURRENT_CONFIG_INDEX &&
                    ed->ued_alt_index == USB_CURRENT_ALT_INDEX)
                        alt = ugen_get_alt_index(sc, ed->ued_interface_index);
                else
                        alt = ed->ued_alt_index;
                edesc = usbd_find_edesc(cdesc, ed->ued_interface_index,
                                        alt, ed->ued_endpoint_index);
                if (edesc == NULL) {
                        free(cdesc, M_TEMP, UGETW(cdesc->wTotalLength));
                        return (EINVAL);
                }
                ed->ued_desc = *edesc;
                free(cdesc, M_TEMP, cdesc_len);
                break;
        case USB_GET_FULL_DESC:
        {
                u_int len;
                struct iovec iov;
                struct uio uio;
                struct usb_full_desc *fd = (struct usb_full_desc *)addr;
                int error;

                cdesc = usbd_get_cdesc(sc->sc_udev, fd->ufd_config_index,
                    &cdesc_len);
                if (cdesc == NULL)
                        return (EINVAL);
                len = cdesc_len;
                if (len > fd->ufd_size)
                        len = fd->ufd_size;
                iov.iov_base = (caddr_t)fd->ufd_data;
                iov.iov_len = len;
                uio.uio_iov = &iov;
                uio.uio_iovcnt = 1;
                uio.uio_resid = len;
                uio.uio_offset = 0;
                uio.uio_segflg = UIO_USERSPACE;
                uio.uio_rw = UIO_READ;
                uio.uio_procp = p;
                error = uiomove((void *)cdesc, len, &uio);
                free(cdesc, M_TEMP, cdesc_len);
                return (error);
        }
        case USB_DO_REQUEST:
        {
                struct usb_ctl_request *ur = (void *)addr;
                size_t len = UGETW(ur->ucr_request.wLength), mlen;
                struct iovec iov;
                struct uio uio;
                void *ptr = NULL;
                int error = 0;

                if (!(flag & FWRITE))
                        return (EPERM);
                /* Avoid requests that would damage the bus integrity. */
                if ((ur->ucr_request.bmRequestType == UT_WRITE_DEVICE &&
                     ur->ucr_request.bRequest == UR_SET_ADDRESS) ||
                    (ur->ucr_request.bmRequestType == UT_WRITE_DEVICE &&
                     ur->ucr_request.bRequest == UR_SET_CONFIG) ||
                    (ur->ucr_request.bmRequestType == UT_WRITE_INTERFACE &&
                     ur->ucr_request.bRequest == UR_SET_INTERFACE))
                        return (EINVAL);

                if (len > 32767)
                        return (EINVAL);
                if (len != 0) {
                        iov.iov_base = (caddr_t)ur->ucr_data;
                        iov.iov_len = len;
                        uio.uio_iov = &iov;
                        uio.uio_iovcnt = 1;
                        uio.uio_resid = len;
                        uio.uio_offset = 0;
                        uio.uio_segflg = UIO_USERSPACE;
                        uio.uio_rw =
                                ur->ucr_request.bmRequestType & UT_READ ?
                                UIO_READ : UIO_WRITE;
                        uio.uio_procp = p;
                        if ((ptr = malloc(len, M_TEMP, M_NOWAIT)) == NULL) {
                                error = ENOMEM;
                                goto ret;
                        }
                        if (uio.uio_rw == UIO_WRITE) {
                                error = uiomove(ptr, len, &uio);
                                if (error)
                                        goto ret;
                        }
                }
                sce = &sc->sc_endpoints[endpt][IN];
                err = usbd_do_request_flags(sc->sc_udev, &ur->ucr_request,
                          ptr, ur->ucr_flags, &ur->ucr_actlen, sce->timeout);
                if (err) {
                        error = EIO;
                        goto ret;
                }
                /* Only if USBD_SHORT_XFER_OK is set. */
                mlen = len;
                if (mlen > ur->ucr_actlen)
                        mlen = ur->ucr_actlen;
                if (mlen != 0) {
                        if (uio.uio_rw == UIO_READ) {
                                error = uiomove(ptr, mlen, &uio);
                                if (error)
                                        goto ret;
                        }
                }
        ret:
                free(ptr, M_TEMP, len);
                return (error);
        }
        case USB_GET_DEVICEINFO:
                usbd_fill_deviceinfo(sc->sc_udev,
                                     (struct usb_device_info *)addr);
                break;
        default:
                return (EINVAL);
        }
        return (0);
}

int
ugenioctl(dev_t dev, u_long cmd, caddr_t addr, int flag, struct proc *p)
{
        int endpt = UGENENDPOINT(dev);
        struct ugen_softc *sc;
        int error;

        sc = ugen_cd.cd_devs[UGENUNIT(dev)];

        sc->sc_refcnt++;
        error = ugen_do_ioctl(sc, endpt, cmd, addr, flag, p);
        if (--sc->sc_refcnt < 0)
                usb_detach_wakeup(&sc->sc_dev);
        return (error);
}

void filt_ugenrdetach(struct knote *);
int filt_ugenread_intr(struct knote *, long);
int filt_ugenread_isoc(struct knote *, long);
int ugenkqfilter(dev_t, struct knote *);

void
filt_ugenrdetach(struct knote *kn)
{
        struct ugen_endpoint *sce = (void *)kn->kn_hook;
        int s;

        s = splusb();
        klist_remove_locked(&sce->rsel.si_note, kn);
        splx(s);
}

int
filt_ugenread_intr(struct knote *kn, long hint)
{
        struct ugen_endpoint *sce = (void *)kn->kn_hook;

        kn->kn_data = sce->q.c_cc;
        return (kn->kn_data > 0);
}

int
filt_ugenread_isoc(struct knote *kn, long hint)
{
        struct ugen_endpoint *sce = (void *)kn->kn_hook;

        if (sce->cur == sce->fill)
                return (0);

        if (sce->cur < sce->fill)
                kn->kn_data = sce->fill - sce->cur;
        else
                kn->kn_data = (sce->limit - sce->cur) +
                    (sce->fill - sce->ibuf);

        return (1);
}

const struct filterops ugenread_intr_filtops = {
        .f_flags        = FILTEROP_ISFD,
        .f_attach       = NULL,
        .f_detach       = filt_ugenrdetach,
        .f_event        = filt_ugenread_intr,
};

const struct filterops ugenread_isoc_filtops = {
        .f_flags        = FILTEROP_ISFD,
        .f_attach       = NULL,
        .f_detach       = filt_ugenrdetach,
        .f_event        = filt_ugenread_isoc,
};

int
ugenkqfilter(dev_t dev, struct knote *kn)
{
        struct ugen_softc *sc;
        struct ugen_endpoint *sce;
        struct klist *klist;
        int s;

        sc = ugen_cd.cd_devs[UGENUNIT(dev)];

        if (usbd_is_dying(sc->sc_udev))
                return (ENXIO);

        /* XXX always IN */
        sce = &sc->sc_endpoints[UGENENDPOINT(dev)][IN];
        if (sce == NULL)
                return (ENXIO);

        switch (kn->kn_filter) {
        case EVFILT_READ:
                klist = &sce->rsel.si_note;
                switch (UE_GET_XFERTYPE(sce->edesc->bmAttributes)) {
                case UE_INTERRUPT:
                        kn->kn_fop = &ugenread_intr_filtops;
                        break;
                case UE_ISOCHRONOUS:
                        kn->kn_fop = &ugenread_isoc_filtops;
                        break;
                case UE_BULK:
                        /*
                         * We have no easy way of determining if a read will
                         * yield any data or a write will happen.
                         */
                        return (seltrue_kqfilter(dev, kn));
                default:
                        return (EINVAL);
                }
                break;

        case EVFILT_WRITE:
                klist = &sce->rsel.si_note;
                switch (UE_GET_XFERTYPE(sce->edesc->bmAttributes)) {
                case UE_INTERRUPT:
                case UE_ISOCHRONOUS:
                        /* XXX poll doesn't support this */
                        return (EINVAL);

                case UE_BULK:
                        /*
                         * We have no easy way of determining if a read will
                         * yield any data or a write will happen.
                         */
                        return (seltrue_kqfilter(dev, kn));
                default:
                        return (EINVAL);
                }
                break;

        default:
                return (EINVAL);
        }

        kn->kn_hook = (void *)sce;

        s = splusb();
        klist_insert_locked(klist, kn);
        splx(s);

        return (0);
}

void
ugen_clear_iface_eps(struct ugen_softc *sc, struct usbd_interface *iface)
{
        usb_interface_descriptor_t *id;
        usb_endpoint_descriptor_t *ed;
        uint8_t xfertype;
        int i;

        /* Only clear interface endpoints when none are in use. */
        for (i = 0; i < USB_MAX_ENDPOINTS; i++) {
                if (i == USB_CONTROL_ENDPOINT)
                        continue;
                if (sc->sc_is_open[i] != 0)
                        return;
        }
        DPRINTFN(1,("%s: clear interface eps\n", __func__));

        id = usbd_get_interface_descriptor(iface);
        if (id == NULL)
                goto bad;

        for (i = 0; i < id->bNumEndpoints; i++) {
                ed = usbd_interface2endpoint_descriptor(iface, i);
                if (ed == NULL)
                        goto bad;

                xfertype = UE_GET_XFERTYPE(ed->bmAttributes);
                if (xfertype == UE_BULK || xfertype == UE_INTERRUPT) {
                        if (usbd_clear_endpoint_feature(sc->sc_udev,
                            ed->bEndpointAddress, UF_ENDPOINT_HALT))
                                goto bad;
                }
        }
        return;
bad:
        printf("%s: clear endpoints failed!\n", __func__);
}