There is no need to explicitly call ttwakeup() and ttwwakeup() after

[dragonfly/port-amd64.git] / sys / dev / usbmisc / ucom / ucom.c

/*
 * $NetBSD: ucom.c,v 1.39 2001/08/16 22:31:24 augustss Exp $
 * $NetBSD: ucom.c,v 1.40 2001/11/13 06:24:54 lukem Exp $
 * $FreeBSD: src/sys/dev/usb/ucom.c,v 1.35 2003/11/16 11:58:21 akiyama Exp $
 * $DragonFly: src/sys/dev/usbmisc/ucom/ucom.c,v 1.31 2007/08/07 13:14:11 hasso Exp $
 */
/*-
 * Copyright (c) 2001-2002, Shunsuke Akiyama <akiyama@jp.FreeBSD.org>.
 * All rights reserved.
 *
 * 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 AUTHOR 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 AUTHOR 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.
 */

/*
 * Copyright (c) 1998, 2000 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *        This product includes software developed by the NetBSD
 *        Foundation, Inc. and its contributors.
 * 4. Neither the name of The NetBSD Foundation nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * 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/kernel.h>
#include <sys/malloc.h>
#include <sys/bus.h>
#include <sys/ioccom.h>
#include <sys/fcntl.h>
#include <sys/conf.h>
#include <sys/tty.h>
#include <sys/clist.h>
#include <sys/file.h>
#include <sys/select.h>
#include <sys/proc.h>
#include <sys/poll.h>
#include <sys/sysctl.h>
#include <sys/thread2.h>

#include <bus/usb/usb.h>
#include <bus/usb/usbcdc.h>

#include <bus/usb/usbdi.h>
#include <bus/usb/usbdi_util.h>
#include <bus/usb/usbdevs.h>
#include <bus/usb/usb_quirks.h>

#include "ucomvar.h"

#ifdef USB_DEBUG
static int      ucomdebug = 0;
SYSCTL_NODE(_hw_usb, OID_AUTO, ucom, CTLFLAG_RW, 0, "USB ucom");
SYSCTL_INT(_hw_usb_ucom, OID_AUTO, debug, CTLFLAG_RW,
           &ucomdebug, 0, "ucom debug level");
#define DPRINTF(x)      do { \
                                if (ucomdebug) \
                                        kprintf x; \
                        } while (0)

#define DPRINTFN(n, x)  do { \
                                if (ucomdebug > (n)) \
                                        kprintf x; \
                        } while (0)
#else
#define DPRINTF(x)
#define DPRINTFN(n, x)
#endif

static d_open_t  ucomopen;
static d_close_t ucomclose;
static d_read_t  ucomread;
static d_write_t ucomwrite;
static d_ioctl_t ucomioctl;

#define UCOM_CDEV_MAJOR  138

static struct dev_ops ucom_ops = {
        { "ucom", UCOM_CDEV_MAJOR, D_TTY | D_KQFILTER },
        .d_open =       ucomopen,
        .d_close =      ucomclose,
        .d_read =       ucomread,
        .d_write =      ucomwrite,
        .d_ioctl =      ucomioctl,
        .d_poll =       ttypoll,
        .d_kqfilter =   ttykqfilter
};

static void ucom_cleanup(struct ucom_softc *);
static int ucomctl(struct ucom_softc *, int, int);
static int ucomparam(struct tty *, struct termios *);
static void ucomstart(struct tty *);
static void ucomstop(struct tty *, int);
static void ucom_shutdown(struct ucom_softc *);
static void ucom_dtr(struct ucom_softc *, int);
static void ucom_rts(struct ucom_softc *, int);
static void ucom_break(struct ucom_softc *, int);
static usbd_status ucomstartread(struct ucom_softc *);
static void ucomreadcb(usbd_xfer_handle, usbd_private_handle, usbd_status);
static void ucomwritecb(usbd_xfer_handle, usbd_private_handle, usbd_status);
static void ucomstopread(struct ucom_softc *);
static void disc_optim(struct tty *, struct termios *, struct ucom_softc *);

devclass_t ucom_devclass;

static moduledata_t ucom_mod = {
        "ucom",
        NULL,
        NULL
};

DECLARE_MODULE(ucom, ucom_mod, SI_SUB_DRIVERS, SI_ORDER_MIDDLE);
MODULE_DEPEND(ucom, usb, 1, 1, 1);
MODULE_VERSION(ucom, UCOM_MODVER);

int
ucom_attach(struct ucom_softc *sc)
{
        struct tty *tp;
        int unit;
        cdev_t dev;

        unit = device_get_unit(sc->sc_dev);

        sc->sc_tty = tp = ttymalloc(sc->sc_tty);
        tp->t_oproc = ucomstart;
        tp->t_param = ucomparam;
        tp->t_stop = ucomstop;

        DPRINTF(("ucom_attach: tty_attach tp = %p\n", tp));

        DPRINTF(("ucom_attach: make_dev: ucom%d\n", unit));

        dev_ops_add(&ucom_ops, UCOMUNIT_MASK, unit);
        dev = make_dev(&ucom_ops, unit | UCOM_CALLOUT_MASK,
                        UID_UUCP, GID_DIALER, 0660,
                        "ucom%d", unit);
        dev->si_tty = tp;

        return (0);
}

int
ucom_detach(struct ucom_softc *sc)
{
        struct tty *tp = sc->sc_tty;
        int unit;

        DPRINTF(("ucom_detach: sc = %p, tp = %p\n", sc, sc->sc_tty));

        sc->sc_dying = 1;

        if (sc->sc_bulkin_pipe != NULL)
                usbd_abort_pipe(sc->sc_bulkin_pipe);
        if (sc->sc_bulkout_pipe != NULL)
                usbd_abort_pipe(sc->sc_bulkout_pipe);

        if (tp != NULL) {
                if (tp->t_state & TS_ISOPEN) {
                        device_printf(sc->sc_dev,
                                      "still open, forcing close\n");
                        (*linesw[tp->t_line].l_close)(tp, 0);
                        ttyclose(tp);
                }
        } else {
                DPRINTF(("ucom_detach: no tty\n"));
                return (0);
        }

        crit_enter();
        if (--sc->sc_refcnt >= 0) {
                /* Wait for processes to go away. */
                usb_detach_wait(sc->sc_dev);
        }
        crit_exit();

        unit = device_get_unit(sc->sc_dev);
        dev_ops_remove(&ucom_ops, UCOMUNIT_MASK, unit);

        return (0);
}

static void
ucom_shutdown(struct ucom_softc *sc)
{
        struct tty *tp = sc->sc_tty;

        DPRINTF(("ucom_shutdown\n"));
        /*
         * Hang up if necessary.  Wait a bit, so the other side has time to
         * notice even if we immediately open the port again.
         */
        if (ISSET(tp->t_cflag, HUPCL)) {
                (void)ucomctl(sc, TIOCM_DTR, DMBIC);
                (void)tsleep(sc, 0, "ucomsd", hz);
        }
}

static int
ucomopen(struct dev_open_args *ap)
{
        cdev_t dev = ap->a_head.a_dev;
        int unit = UCOMUNIT(dev);
        struct ucom_softc *sc;
        usbd_status err;
        struct tty *tp;
        int error;

        sc = devclass_get_softc(ucom_devclass, unit);
        if (sc == NULL)
                return (ENXIO);

        if (sc->sc_dying)
                return (ENXIO);

        tp = sc->sc_tty;

        DPRINTF(("%s: ucomopen: tp = %p\n", device_get_nameunit(sc->sc_dev), tp));

        if (ISSET(tp->t_state, TS_ISOPEN) &&
            ISSET(tp->t_state, TS_XCLUDE) &&
            suser_cred(ap->a_cred, 0)
        ) {
                return (EBUSY);
        }

        /*
         * Do the following iff this is a first open.
         */
        crit_enter();
        while (sc->sc_opening)
                tsleep(&sc->sc_opening, 0, "ucomop", 0);
        sc->sc_opening = 1;

        if (!ISSET(tp->t_state, TS_ISOPEN)) {
                struct termios t;

                sc->sc_poll = 0;
                sc->sc_lsr = sc->sc_msr = sc->sc_mcr = 0;

                tp->t_dev = reference_dev(dev);

                /*
                 * Initialize the termios status to the defaults.  Add in the
                 * sticky bits from TIOCSFLAGS.
                 */
                t.c_ispeed = 0;
                t.c_ospeed = TTYDEF_SPEED;
                t.c_cflag = TTYDEF_CFLAG;
                /* Make sure ucomparam() will do something. */
                tp->t_ospeed = 0;
                (void)ucomparam(tp, &t);
                tp->t_iflag = TTYDEF_IFLAG;
                tp->t_oflag = TTYDEF_OFLAG;
                tp->t_lflag = TTYDEF_LFLAG;
                ttychars(tp);
                ttsetwater(tp);

                /*
                 * Turn on DTR.  We must always do this, even if carrier is not
                 * present, because otherwise we'd have to use TIOCSDTR
                 * immediately after setting CLOCAL, which applications do not
                 * expect.  We always assert DTR while the device is open
                 * unless explicitly requested to deassert it.
                 */
                (void)ucomctl(sc, TIOCM_DTR | TIOCM_RTS, DMBIS);

                /* Device specific open */
                if (sc->sc_callback->ucom_open != NULL) {
                        error = sc->sc_callback->ucom_open(sc->sc_parent,
                                                           sc->sc_portno);
                        if (error) {
                                ucom_cleanup(sc);
                                sc->sc_opening = 0;
                                wakeup(&sc->sc_opening);
                                crit_exit();
                                return (error);
                        }
                }

                DPRINTF(("ucomopen: open pipes in = %d out = %d\n",
                         sc->sc_bulkin_no, sc->sc_bulkout_no));

                /* Open the bulk pipes */
                /* Bulk-in pipe */
                err = usbd_open_pipe(sc->sc_iface, sc->sc_bulkin_no, 0,
                                     &sc->sc_bulkin_pipe);
                if (err) {
                        kprintf("%s: open bulk in error (addr %d): %s\n",
                               device_get_nameunit(sc->sc_dev), sc->sc_bulkin_no,
                               usbd_errstr(err));
                        error = EIO;
                        goto fail_0;
                }
                /* Bulk-out pipe */
                err = usbd_open_pipe(sc->sc_iface, sc->sc_bulkout_no,
                                     USBD_EXCLUSIVE_USE, &sc->sc_bulkout_pipe);
                if (err) {
                        kprintf("%s: open bulk out error (addr %d): %s\n",
                               device_get_nameunit(sc->sc_dev), sc->sc_bulkout_no,
                               usbd_errstr(err));
                        error = EIO;
                        goto fail_1;
                }

                /* Allocate a request and an input buffer and start reading. */
                sc->sc_ixfer = usbd_alloc_xfer(sc->sc_udev);
                if (sc->sc_ixfer == NULL) {
                        error = ENOMEM;
                        goto fail_2;
                }

                sc->sc_ibuf = usbd_alloc_buffer(sc->sc_ixfer,
                                                sc->sc_ibufsizepad);
                if (sc->sc_ibuf == NULL) {
                        error = ENOMEM;
                        goto fail_3;
                }

                sc->sc_oxfer = usbd_alloc_xfer(sc->sc_udev);
                if (sc->sc_oxfer == NULL) {
                        error = ENOMEM;
                        goto fail_3;
                }

                sc->sc_obuf = usbd_alloc_buffer(sc->sc_oxfer,
                                                sc->sc_obufsize +
                                                sc->sc_opkthdrlen);
                if (sc->sc_obuf == NULL) {
                        error = ENOMEM;
                        goto fail_4;
                }

                /*
                 * Handle initial DCD.
                 */
                if (ISSET(sc->sc_msr, UMSR_DCD) ||
                    (minor(dev) & UCOM_CALLOUT_MASK))
                        (*linesw[tp->t_line].l_modem)(tp, 1);

                ucomstartread(sc);
        }

        sc->sc_opening = 0;
        wakeup(&sc->sc_opening);
        crit_exit();

        error = ttyopen(dev, tp);
        if (error)
                goto bad;

        error = (*linesw[tp->t_line].l_open)(dev, tp);
        if (error)
                goto bad;

        disc_optim(tp, &tp->t_termios, sc);

        DPRINTF(("%s: ucomopen: success\n", device_get_nameunit(sc->sc_dev)));

        sc->sc_poll = 1;
        sc->sc_refcnt++;

        return (0);

fail_4:
        usbd_free_xfer(sc->sc_oxfer);
        sc->sc_oxfer = NULL;
fail_3:
        usbd_free_xfer(sc->sc_ixfer);
        sc->sc_ixfer = NULL;
fail_2:
        usbd_close_pipe(sc->sc_bulkout_pipe);
        sc->sc_bulkout_pipe = NULL;
fail_1:
        usbd_close_pipe(sc->sc_bulkin_pipe);
        sc->sc_bulkin_pipe = NULL;
fail_0:
        sc->sc_opening = 0;
        wakeup(&sc->sc_opening);
        crit_exit();
        return (error);

bad:
        if (!ISSET(tp->t_state, TS_ISOPEN)) {
                /*
                 * We failed to open the device, and nobody else had it opened.
                 * Clean up the state as appropriate.
                 */
                ucom_cleanup(sc);
        }

        DPRINTF(("%s: ucomopen: failed\n", device_get_nameunit(sc->sc_dev)));

        return (error);
}

static int
ucomclose(struct dev_close_args *ap)
{
        cdev_t dev = ap->a_head.a_dev;
        struct ucom_softc *sc;
        struct tty *tp;

        sc = devclass_get_softc(ucom_devclass, UCOMUNIT(dev));

        tp = sc->sc_tty;

        DPRINTF(("%s: ucomclose: unit = %d\n",
                device_get_nameunit(sc->sc_dev), UCOMUNIT(dev)));

        if (!ISSET(tp->t_state, TS_ISOPEN))
                goto quit;

        crit_enter();
        (*linesw[tp->t_line].l_close)(tp, ap->a_fflag);
        disc_optim(tp, &tp->t_termios, sc);
        ttyclose(tp);
        crit_exit();

        if (sc->sc_dying)
                goto quit;

        if (!ISSET(tp->t_state, TS_ISOPEN)) {
                /*
                 * Although we got a last close, the device may still be in
                 * use; e.g. if this was the dialout node, and there are still
                 * processes waiting for carrier on the non-dialout node.
                 */
                ucom_cleanup(sc);
        }

        if (sc->sc_callback->ucom_close != NULL)
                sc->sc_callback->ucom_close(sc->sc_parent, sc->sc_portno);

quit:
        if (tp->t_dev) {
                release_dev(tp->t_dev);
                tp->t_dev = NULL;
        }

        if (--sc->sc_refcnt < 0)
                usb_detach_wakeup(sc->sc_dev);

        return (0);
}

static int
ucomread(struct dev_read_args *ap)
{
        cdev_t dev = ap->a_head.a_dev;
        struct ucom_softc *sc;
        struct tty *tp;
        int error;

        sc = devclass_get_softc(ucom_devclass, UCOMUNIT(dev));
        tp = sc->sc_tty;

        DPRINTF(("ucomread: tp = %p, flag = 0x%x\n", tp, ap->a_ioflag));

        if (sc->sc_dying)
                return (EIO);

        error = (*linesw[tp->t_line].l_read)(tp, ap->a_uio, ap->a_ioflag);

        DPRINTF(("ucomread: error = %d\n", error));

        return (error);
}

static int
ucomwrite(struct dev_write_args *ap)
{
        cdev_t dev = ap->a_head.a_dev;
        struct ucom_softc *sc;
        struct tty *tp;
        int error;

        sc = devclass_get_softc(ucom_devclass, UCOMUNIT(dev));
        tp = sc->sc_tty;

        DPRINTF(("ucomwrite: tp = %p, flag = 0x%x\n", tp, ap->a_ioflag));

        if (sc->sc_dying)
                return (EIO);

        error = (*linesw[tp->t_line].l_write)(tp, ap->a_uio, ap->a_ioflag);

        DPRINTF(("ucomwrite: error = %d\n", error));

        return (error);
}

static int
ucomioctl(struct dev_ioctl_args *ap)
{
        cdev_t dev = ap->a_head.a_dev;
        struct ucom_softc *sc;
        struct tty *tp;
        int error;
        int d;

        sc = devclass_get_softc(ucom_devclass, UCOMUNIT(dev));
        tp = sc->sc_tty;

        if (sc->sc_dying)
                return (EIO);

        DPRINTF(("ucomioctl: cmd = 0x%08lx\n", ap->a_cmd));

        error = (*linesw[tp->t_line].l_ioctl)(tp, ap->a_cmd, ap->a_data,
                                              ap->a_fflag, ap->a_cred);
        if (error != ENOIOCTL) {
                DPRINTF(("ucomioctl: l_ioctl: error = %d\n", error));
                return (error);
        }

        crit_enter();

        error = ttioctl(tp, ap->a_cmd, ap->a_data, ap->a_fflag);
        disc_optim(tp, &tp->t_termios, sc);
        if (error != ENOIOCTL) {
                crit_exit();
                DPRINTF(("ucomioctl: ttioctl: error = %d\n", error));
                return (error);
        }

        if (sc->sc_callback->ucom_ioctl != NULL) {
                error = sc->sc_callback->ucom_ioctl(sc->sc_parent,
                                                    sc->sc_portno,
                                                    ap->a_cmd, ap->a_data,
                                                    ap->a_fflag, curthread);
                if (error >= 0) {
                        crit_exit();
                        return (error);
                }
        }

        error = 0;

        DPRINTF(("ucomioctl: our cmd = 0x%08lx\n", ap->a_cmd));

        switch (ap->a_cmd) {
        case TIOCSBRK:
                DPRINTF(("ucomioctl: TIOCSBRK\n"));
                ucom_break(sc, 1);
                break;
        case TIOCCBRK:
                DPRINTF(("ucomioctl: TIOCCBRK\n"));
                ucom_break(sc, 0);
                break;

        case TIOCSDTR:
                DPRINTF(("ucomioctl: TIOCSDTR\n"));
                (void)ucomctl(sc, TIOCM_DTR, DMBIS);
                break;
        case TIOCCDTR:
                DPRINTF(("ucomioctl: TIOCCDTR\n"));
                (void)ucomctl(sc, TIOCM_DTR, DMBIC);
                break;

        case TIOCMSET:
                d = *(int *)ap->a_data;
                DPRINTF(("ucomioctl: TIOCMSET, 0x%x\n", d));
                (void)ucomctl(sc, d, DMSET);
                break;
        case TIOCMBIS:
                d = *(int *)ap->a_data;
                DPRINTF(("ucomioctl: TIOCMBIS, 0x%x\n", d));
                (void)ucomctl(sc, d, DMBIS);
                break;
        case TIOCMBIC:
                d = *(int *)ap->a_data;
                DPRINTF(("ucomioctl: TIOCMBIC, 0x%x\n", d));
                (void)ucomctl(sc, d, DMBIC);
                break;
        case TIOCMGET:
                d = ucomctl(sc, 0, DMGET);
                DPRINTF(("ucomioctl: TIOCMGET, 0x%x\n", d));
                *(int *)ap->a_data = d;
                break;

        default:
                DPRINTF(("ucomioctl: error: our cmd = 0x%08lx\n", ap->a_cmd));
                error = ENOTTY;
                break;
        }

        crit_exit();

        return (error);
}

static int
ucomctl(struct ucom_softc *sc, int bits, int how)
{
        int     mcr;
        int     msr;
        int     onoff;

        DPRINTF(("ucomctl: bits = 0x%x, how = %d\n", bits, how));

        if (how == DMGET) {
                SET(bits, TIOCM_LE);            /* always set TIOCM_LE bit */
                DPRINTF(("ucomctl: DMGET: LE"));

                mcr = sc->sc_mcr;
                if (ISSET(mcr, UMCR_DTR)) {
                        SET(bits, TIOCM_DTR);
                        DPRINTF((" DTR"));
                }
                if (ISSET(mcr, UMCR_RTS)) {
                        SET(bits, TIOCM_RTS);
                        DPRINTF((" RTS"));
                }

                msr = sc->sc_msr;
                if (ISSET(msr, UMSR_CTS)) {
                        SET(bits, TIOCM_CTS);
                        DPRINTF((" CTS"));
                }
                if (ISSET(msr, UMSR_DCD)) {
                        SET(bits, TIOCM_CD);
                        DPRINTF((" CD"));
                }
                if (ISSET(msr, UMSR_DSR)) {
                        SET(bits, TIOCM_DSR);
                        DPRINTF((" DSR"));
                }
                if (ISSET(msr, UMSR_RI)) {
                        SET(bits, TIOCM_RI);
                        DPRINTF((" RI"));
                }

                DPRINTF(("\n"));

                return (bits);
        }

        mcr = 0;
        if (ISSET(bits, TIOCM_DTR))
                SET(mcr, UMCR_DTR);
        if (ISSET(bits, TIOCM_RTS))
                SET(mcr, UMCR_RTS);

        switch (how) {
        case DMSET:
                sc->sc_mcr = mcr;
                break;
        case DMBIS:
                sc->sc_mcr |= mcr;
                break;
        case DMBIC:
                sc->sc_mcr &= ~mcr;
                break;
        }

        onoff = ISSET(sc->sc_mcr, UMCR_DTR) ? 1 : 0;
        ucom_dtr(sc, onoff);

        onoff = ISSET(sc->sc_mcr, UMCR_RTS) ? 1 : 0;
        ucom_rts(sc, onoff);

        return (0);
}

static void
ucom_break(struct ucom_softc *sc, int onoff)
{
        DPRINTF(("ucom_break: onoff = %d\n", onoff));

        if (sc->sc_callback->ucom_set == NULL)
                return;
        sc->sc_callback->ucom_set(sc->sc_parent, sc->sc_portno,
                                  UCOM_SET_BREAK, onoff);
}

static void
ucom_dtr(struct ucom_softc *sc, int onoff)
{
        DPRINTF(("ucom_dtr: onoff = %d\n", onoff));

        if (sc->sc_callback->ucom_set == NULL)
                return;
        sc->sc_callback->ucom_set(sc->sc_parent, sc->sc_portno,
                                  UCOM_SET_DTR, onoff);
}

static void
ucom_rts(struct ucom_softc *sc, int onoff)
{
        DPRINTF(("ucom_rts: onoff = %d\n", onoff));

        if (sc->sc_callback->ucom_set == NULL)
                return;
        sc->sc_callback->ucom_set(sc->sc_parent, sc->sc_portno,
                                  UCOM_SET_RTS, onoff);
}

void
ucom_status_change(struct ucom_softc *sc)
{
        struct tty *tp = sc->sc_tty;
        u_char old_msr;
        int onoff;

        if (sc->sc_callback->ucom_get_status == NULL) {
                sc->sc_lsr = 0;
                sc->sc_msr = 0;
                return;
        }

        old_msr = sc->sc_msr;
        sc->sc_callback->ucom_get_status(sc->sc_parent, sc->sc_portno,
                                         &sc->sc_lsr, &sc->sc_msr);
        if (ISSET((sc->sc_msr ^ old_msr), UMSR_DCD)) {
                if (sc->sc_poll == 0)
                        return;
                onoff = ISSET(sc->sc_msr, UMSR_DCD) ? 1 : 0;
                DPRINTF(("ucom_status_change: DCD changed to %d\n", onoff));
                (*linesw[tp->t_line].l_modem)(tp, onoff);
        }
}

static int
ucomparam(struct tty *tp, struct termios *t)
{
        struct ucom_softc *sc;
        int error;
        usbd_status uerr;

        sc = devclass_get_softc(ucom_devclass, UCOMUNIT(tp->t_dev));

        if (sc->sc_dying)
                return (EIO);

        DPRINTF(("ucomparam: sc = %p\n", sc));

        /* Check requested parameters. */
        if (t->c_ospeed < 0) {
                DPRINTF(("ucomparam: negative ospeed\n"));
                return (EINVAL);
        }
        if (t->c_ispeed && t->c_ispeed != t->c_ospeed) {
                DPRINTF(("ucomparam: mismatch ispeed and ospeed\n"));
                return (EINVAL);
        }

        /*
         * If there were no changes, don't do anything.  This avoids dropping
         * input and improves performance when all we did was frob things like
         * VMIN and VTIME.
         */
        if (tp->t_ospeed == t->c_ospeed &&
            tp->t_cflag == t->c_cflag)
                return (0);

        /* And copy to tty. */
        tp->t_ispeed = 0;
        tp->t_ospeed = t->c_ospeed;
        tp->t_cflag = t->c_cflag;

        if (sc->sc_callback->ucom_param == NULL)
                return (0);

        ucomstopread(sc);

        error = sc->sc_callback->ucom_param(sc->sc_parent, sc->sc_portno, t);
        if (error) {
                DPRINTF(("ucomparam: callback: error = %d\n", error));
                return (error);
        }

        ttsetwater(tp);

        if (t->c_cflag & CRTS_IFLOW) {
                sc->sc_state |= UCS_RTS_IFLOW;
        } else if (sc->sc_state & UCS_RTS_IFLOW) {
                sc->sc_state &= ~UCS_RTS_IFLOW;
                (void)ucomctl(sc, UMCR_RTS, DMBIS);
        }

        disc_optim(tp, t, sc);

        uerr = ucomstartread(sc);
        if (uerr != USBD_NORMAL_COMPLETION)
                return (EIO);

        return (0);
}

static void
ucomstart(struct tty *tp)
{
        struct ucom_softc *sc;
        struct cblock *cbp;
        usbd_status err;
        u_char *data;
        int cnt;

        sc = devclass_get_softc(ucom_devclass, UCOMUNIT(tp->t_dev));
        DPRINTF(("ucomstart: sc = %p\n", sc));

        if (sc->sc_dying)
                return;

        crit_enter();

        if (tp->t_state & TS_TBLOCK) {
                if (ISSET(sc->sc_mcr, UMCR_RTS) &&
                    ISSET(sc->sc_state, UCS_RTS_IFLOW)) {
                        DPRINTF(("ucomstart: clear RTS\n"));
                        (void)ucomctl(sc, UMCR_RTS, DMBIC);
                }
        } else {
                if (!ISSET(sc->sc_mcr, UMCR_RTS) &&
                    tp->t_rawq.c_cc <= tp->t_ilowat &&
                    ISSET(sc->sc_state, UCS_RTS_IFLOW)) {
                        DPRINTF(("ucomstart: set RTS\n"));
                        (void)ucomctl(sc, UMCR_RTS, DMBIS);
                }
        }

        if (ISSET(tp->t_state, TS_BUSY | TS_TIMEOUT | TS_TTSTOP)) {
                ttwwakeup(tp);
                DPRINTF(("ucomstart: stopped\n"));
                goto out;
        }

        if (tp->t_outq.c_cc <= tp->t_olowat) {
                if (ISSET(tp->t_state, TS_SO_OLOWAT)) {
                        CLR(tp->t_state, TS_SO_OLOWAT);
                        wakeup(TSA_OLOWAT(tp));
                }
                selwakeup(&tp->t_wsel);
                if (tp->t_outq.c_cc == 0) {
                        if (ISSET(tp->t_state, TS_BUSY | TS_SO_OCOMPLETE) ==
                            TS_SO_OCOMPLETE && tp->t_outq.c_cc == 0) {
                                CLR(tp->t_state, TS_SO_OCOMPLETE);
                                wakeup(TSA_OCOMPLETE(tp));
                        }
                        goto out;
                }
        }

        /* Grab the first contiguous region of buffer space. */
        data = tp->t_outq.c_cf;
        cbp = (struct cblock *) ((intptr_t) tp->t_outq.c_cf & ~CROUND);
        cnt = min((char *) (cbp+1) - tp->t_outq.c_cf, tp->t_outq.c_cc);

        if (cnt == 0) {
                DPRINTF(("ucomstart: cnt == 0\n"));
                goto out;
        }

        SET(tp->t_state, TS_BUSY);

        if (cnt > sc->sc_obufsize) {
                DPRINTF(("ucomstart: big buffer %d chars\n", cnt));
                cnt = sc->sc_obufsize;
        }
        if (sc->sc_callback->ucom_write != NULL)
                sc->sc_callback->ucom_write(sc->sc_parent, sc->sc_portno,
                                            sc->sc_obuf, data, &cnt);
        else
                memcpy(sc->sc_obuf, data, cnt);

        DPRINTF(("ucomstart: %d chars\n", cnt));
        usbd_setup_xfer(sc->sc_oxfer, sc->sc_bulkout_pipe,
                        (usbd_private_handle)sc, sc->sc_obuf, cnt,
                        USBD_NO_COPY, USBD_NO_TIMEOUT, ucomwritecb);
        /* What can we do on error? */
        err = usbd_transfer(sc->sc_oxfer);
        if (err != USBD_IN_PROGRESS)
                kprintf("ucomstart: err=%s\n", usbd_errstr(err));

        ttwwakeup(tp);

    out:
        crit_exit();
}

static void
ucomstop(struct tty *tp, int flag)
{
        struct ucom_softc *sc;

        sc = devclass_get_softc(ucom_devclass, UCOMUNIT(tp->t_dev));

        DPRINTF(("ucomstop: %d\n", flag));

        if (flag & FREAD) {
                /*
                 * This is just supposed to flush pending receive data,
                 * not stop the reception of data entirely!
                 */
                DPRINTF(("ucomstop: read\n"));
                ucomstopread(sc);
                ucomstartread(sc);
        }

        if (flag & FWRITE) {
                DPRINTF(("ucomstop: write\n"));
                crit_enter();
                if (ISSET(tp->t_state, TS_BUSY)) {
                        /* XXX do what? */
                        if (!ISSET(tp->t_state, TS_TTSTOP))
                                SET(tp->t_state, TS_FLUSH);
                }
                crit_exit();
        }

        DPRINTF(("ucomstop: done\n"));
}

static void
ucomwritecb(usbd_xfer_handle xfer, usbd_private_handle p, usbd_status status)
{
        struct ucom_softc *sc = (struct ucom_softc *)p;
        struct tty *tp = sc->sc_tty;
        u_int32_t cc;

        DPRINTF(("ucomwritecb: status = %d\n", status));

        if (status == USBD_CANCELLED || sc->sc_dying)
                goto error;

        if (status != USBD_NORMAL_COMPLETION) {
                kprintf("%s: ucomwritecb: %s\n",
                       device_get_nameunit(sc->sc_dev), usbd_errstr(status));
                if (status == USBD_STALLED)
                        usbd_clear_endpoint_stall_async(sc->sc_bulkin_pipe);
                /*
                 * XXX.  We may need a flag to sequence ucomstopread() and
                 * ucomstartread() to handle the case where ucomstartread()
                 * is called after ucomstopread() but before the request has
                 * been properly canceled?
                 */
                goto error;
        }

        usbd_get_xfer_status(xfer, NULL, NULL, &cc, NULL);
        DPRINTF(("ucomwritecb: cc = %d\n", cc));
        if (cc <= sc->sc_opkthdrlen) {
                kprintf("%s: sent size too small, cc = %d\n",
                        device_get_nameunit(sc->sc_dev), cc);
                goto error;
        }

        /* convert from USB bytes to tty bytes */
        cc -= sc->sc_opkthdrlen;

        crit_enter();
        CLR(tp->t_state, TS_BUSY);
        if (ISSET(tp->t_state, TS_FLUSH))
                CLR(tp->t_state, TS_FLUSH);
        else
                ndflush(&tp->t_outq, cc);
        (*linesw[tp->t_line].l_start)(tp);
        crit_exit();

        return;

  error:
        crit_enter();
        CLR(tp->t_state, TS_BUSY);
        crit_exit();
        return;
}

static usbd_status
ucomstartread(struct ucom_softc *sc)
{
        usbd_status err;

        DPRINTF(("ucomstartread: start\n"));

        sc->sc_state &= ~UCS_RXSTOP;

        if (sc->sc_bulkin_pipe == NULL)
                return (USBD_NORMAL_COMPLETION);

        usbd_setup_xfer(sc->sc_ixfer, sc->sc_bulkin_pipe,
                        (usbd_private_handle)sc,
                        sc->sc_ibuf, sc->sc_ibufsize,
                        USBD_SHORT_XFER_OK | USBD_NO_COPY,
                        USBD_NO_TIMEOUT, ucomreadcb);

        err = usbd_transfer(sc->sc_ixfer);
        if (err != USBD_IN_PROGRESS) {
                DPRINTF(("ucomstartread: err = %s\n", usbd_errstr(err)));
                return (err);
        }

        return (USBD_NORMAL_COMPLETION);
}

static void
ucomreadcb(usbd_xfer_handle xfer, usbd_private_handle p, usbd_status status)
{
        struct ucom_softc *sc = (struct ucom_softc *)p;
        struct tty *tp = sc->sc_tty;
        int (*rint) (int c, struct tty *tp) = linesw[tp->t_line].l_rint;
        usbd_status err;
        u_int32_t cc;
        u_char *cp;
        int lostcc;

        DPRINTF(("ucomreadcb: status = %d\n", status));

        if (status != USBD_NORMAL_COMPLETION) {
                if (!(sc->sc_state & UCS_RXSTOP))
                        kprintf("%s: ucomreadcb: %s\n",
                               device_get_nameunit(sc->sc_dev), usbd_errstr(status));
                if (status == USBD_STALLED)
                        usbd_clear_endpoint_stall_async(sc->sc_bulkin_pipe);
                /* XXX we should restart after some delay. */
                return;
        }

        usbd_get_xfer_status(xfer, NULL, (void **)&cp, &cc, NULL);
        DPRINTF(("ucomreadcb: got %d chars, tp = %p\n", cc, tp));
        if (cc == 0)
                goto resubmit;

        if (sc->sc_callback->ucom_read != NULL) {
                sc->sc_callback->ucom_read(sc->sc_parent, sc->sc_portno,
                                           &cp, &cc);
        }

        if (cc > sc->sc_ibufsize) {
                kprintf("%s: invalid receive data size, %d chars\n",
                        device_get_nameunit(sc->sc_dev), cc);
                goto resubmit;
        }
        if (cc < 1)
                goto resubmit;

        crit_enter();
        if (tp->t_state & TS_CAN_BYPASS_L_RINT) {
                if (tp->t_rawq.c_cc + cc > tp->t_ihiwat
                    && (sc->sc_state & UCS_RTS_IFLOW
                        || tp->t_iflag & IXOFF)
                    && !(tp->t_state & TS_TBLOCK))
                        ttyblock(tp);
                lostcc = b_to_q((char *)cp, cc, &tp->t_rawq);
                tp->t_rawcc += cc;
                if (sc->hotchar) {
                        while (cc) {
                                if (*cp == sc->hotchar)
                                        break;
                                --cc;
                                ++cp;
                        }
                        if (cc)
                                setsofttty();
                }
                ttwakeup(tp);
                if (tp->t_state & TS_TTSTOP
                    && (tp->t_iflag & IXANY
                        || tp->t_cc[VSTART] == tp->t_cc[VSTOP])) {
                        tp->t_state &= ~TS_TTSTOP;
                        tp->t_lflag &= ~FLUSHO;
                        ucomstart(tp);
                }
                if (lostcc > 0)
                        kprintf("%s: lost %d chars\n", device_get_nameunit(sc->sc_dev),
                               lostcc);
        } else {
                /* Give characters to tty layer. */
                while (cc > 0) {
                        DPRINTFN(7, ("ucomreadcb: char = 0x%02x\n", *cp));
                        if ((*rint)(*cp, tp) == -1) {
                                /* XXX what should we do? */
                                kprintf("%s: lost %d chars\n",
                                       device_get_nameunit(sc->sc_dev), cc);
                                break;
                        }
                        cc--;
                        cp++;
                }
        }
        crit_exit();

resubmit:
        err = ucomstartread(sc);
        if (err) {
                kprintf("%s: read start failed\n", device_get_nameunit(sc->sc_dev));
                /* XXX what should we dow now? */
        }

        if ((sc->sc_state & UCS_RTS_IFLOW) && !ISSET(sc->sc_mcr, UMCR_RTS)
            && !(tp->t_state & TS_TBLOCK))
                ucomctl(sc, UMCR_RTS, DMBIS);
}

static void
ucom_cleanup(struct ucom_softc *sc)
{
        DPRINTF(("ucom_cleanup: closing pipes\n"));

        ucom_shutdown(sc);
        if (sc->sc_bulkin_pipe != NULL) {
                usbd_abort_pipe(sc->sc_bulkin_pipe);
                usbd_close_pipe(sc->sc_bulkin_pipe);
                sc->sc_bulkin_pipe = NULL;
        }
        if (sc->sc_bulkout_pipe != NULL) {
                usbd_abort_pipe(sc->sc_bulkout_pipe);
                usbd_close_pipe(sc->sc_bulkout_pipe);
                sc->sc_bulkout_pipe = NULL;
        }
        if (sc->sc_ixfer != NULL) {
                usbd_free_xfer(sc->sc_ixfer);
                sc->sc_ixfer = NULL;
        }
        if (sc->sc_oxfer != NULL) {
                usbd_free_xfer(sc->sc_oxfer);
                sc->sc_oxfer = NULL;
        }
}

static void
ucomstopread(struct ucom_softc *sc)
{
        usbd_status err;

        DPRINTF(("ucomstopread: enter\n"));

        if (!(sc->sc_state & UCS_RXSTOP)) {
                sc->sc_state |= UCS_RXSTOP;
                if (sc->sc_bulkin_pipe == NULL) {
                        DPRINTF(("ucomstopread: bulkin pipe NULL\n"));
                        return;
                }
                err = usbd_abort_pipe(sc->sc_bulkin_pipe);
                if (err) {
                        DPRINTF(("ucomstopread: err = %s\n",
                                 usbd_errstr(err)));
                }
        }

        DPRINTF(("ucomstopread: leave\n"));
}

static void
disc_optim(struct tty *tp, struct termios *t, struct ucom_softc *sc)
{
        if (!(t->c_iflag & (ICRNL | IGNCR | IMAXBEL | INLCR | ISTRIP | IXON))
            && (!(t->c_iflag & BRKINT) || (t->c_iflag & IGNBRK))
            && (!(t->c_iflag & PARMRK)
                || (t->c_iflag & (IGNPAR | IGNBRK)) == (IGNPAR | IGNBRK))
            && !(t->c_lflag & (ECHO | ICANON | IEXTEN | ISIG | PENDIN))
            && linesw[tp->t_line].l_rint == ttyinput) {
                DPRINTF(("disc_optim: bypass l_rint\n"));
                tp->t_state |= TS_CAN_BYPASS_L_RINT;
        } else {
                DPRINTF(("disc_optim: can't bypass l_rint\n"));
                tp->t_state &= ~TS_CAN_BYPASS_L_RINT;
        }
        sc->hotchar = linesw[tp->t_line].l_hotchar;
}