/*      $OpenBSD: ucom.c,v 1.79 2024/05/23 03:21:09 jsg Exp $ */
/*      $NetBSD: ucom.c,v 1.49 2003/01/01 00:10:25 thorpej Exp $        */

/*
 * 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.
 *
 * 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.
 */
/*
 * This code is very heavily based on the 16550 driver, com.c.
 */

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

#include <dev/usb/usb.h>

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

#include <dev/usb/ucomvar.h>

#include "ucom.h"

#if NUCOM > 0

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

#define UCOMUNIT_MASK           0x7f
#define UCOMCUA_MASK            0x80

#define LINESW(tp, func)        (linesw[(tp)->t_line].func)

#define UCOMUNIT(x)             (minor(x) & UCOMUNIT_MASK)
#define UCOMCUA(x)              (minor(x) & UCOMCUA_MASK)

#define ROUTEROOTPORT(_x)       ((_x) & 0xff)
#define ROUTESTRING(_x)         (((_x) >> 8) & 0xfffff)

struct ucom_softc {
        struct device           sc_dev;         /* base device */

        struct usbd_device      *sc_uparent;    /* USB device */
        struct uhidev_softc     *sc_uhidev;     /* hid device (if deeper) */

        struct usbd_interface   *sc_iface;      /* data interface */

        int                     sc_bulkin_no;   /* bulk in endpoint address */
        struct usbd_pipe        *sc_bulkin_pipe;/* bulk in pipe */
        struct usbd_xfer        *sc_ixfer;      /* read request */
        u_char                  *sc_ibuf;       /* read buffer */
        u_int                   sc_ibufsize;    /* read buffer size */
        u_int                   sc_ibufsizepad; /* read buffer size padded */

        int                     sc_bulkout_no;  /* bulk out endpoint address */
        struct usbd_pipe        *sc_bulkout_pipe;/* bulk out pipe */
        struct usbd_xfer        *sc_oxfer;      /* write request */
        u_char                  *sc_obuf;       /* write buffer */
        u_int                   sc_obufsize;    /* write buffer size */
        u_int                   sc_opkthdrlen;  /* header length of
                                                 * output packet */

        struct usbd_pipe        *sc_ipipe;      /* hid interrupt input pipe */
        struct usbd_pipe        *sc_opipe;      /* hid interrupt pipe */

        const struct ucom_methods *sc_methods;
        void                    *sc_parent;
        int                     sc_portno;

        struct tty              *sc_tty;        /* our tty */
        u_char                  sc_lsr;
        u_char                  sc_msr;
        u_char                  sc_mcr;
        u_char                  sc_tx_stopped;
        int                     sc_swflags;

        u_char                  sc_cua;
        int                     sc_error;

        struct rwlock           sc_lock;        /* lock during open */
        int                     sc_open;
        int                     sc_refcnt;
};

void    ucom_cleanup(struct ucom_softc *);
void    ucom_hwiflow(struct ucom_softc *);
int     ucomparam(struct tty *, struct termios *);
void    ucomstart(struct tty *);
void    ucom_shutdown(struct ucom_softc *);
int     ucom_do_open(dev_t, int, int, struct proc *);
int     ucom_do_ioctl(struct ucom_softc *, u_long, caddr_t, int, struct proc *);
int     ucom_do_close(struct ucom_softc *, int, int , struct proc *);
void    ucom_dtr(struct ucom_softc *, int);
void    ucom_rts(struct ucom_softc *, int);
void    ucom_break(struct ucom_softc *, int);
usbd_status ucomstartread(struct ucom_softc *);
void    ucomreadcb(struct usbd_xfer *, void *, usbd_status);
void    ucomwritecb(struct usbd_xfer *, void *, usbd_status);
void    tiocm_to_ucom(struct ucom_softc *, u_long, int);
int     ucom_to_tiocm(struct ucom_softc *);
void    ucom_lock(struct ucom_softc *);
void    ucom_unlock(struct ucom_softc *);

int ucom_match(struct device *, void *, void *);
void ucom_attach(struct device *, struct device *, void *);
int ucom_detach(struct device *, int);

struct cfdriver ucom_cd = {
        NULL, "ucom", DV_TTY
};

const struct cfattach ucom_ca = {
        sizeof(struct ucom_softc),
        ucom_match,
        ucom_attach,
        ucom_detach,
};

static int ucom_change;
struct rwlock sysctl_ucomlock = RWLOCK_INITIALIZER("sysctlulk");

void
ucom_lock(struct ucom_softc *sc)
{
        rw_enter_write(&sc->sc_lock);
}

void
ucom_unlock(struct ucom_softc *sc)
{
        rw_exit_write(&sc->sc_lock);
}

int
ucom_match(struct device *parent, void *match, void *aux)
{
        return (1);
}

void
ucom_attach(struct device *parent, struct device *self, void *aux)
{
        char path[32];  /* "usb000.000.00000.000" */
        struct ucom_softc *sc = (struct ucom_softc *)self;
        struct ucom_attach_args *uca = aux;
        struct tty *tp;
        uint32_t route;
        uint8_t bus, ifaceno;

        if (uca->info != NULL)
                printf(", %s", uca->info);

        sc->sc_uparent = uca->device;
        sc->sc_iface = uca->iface;
        sc->sc_bulkout_no = uca->bulkout;
        sc->sc_bulkin_no = uca->bulkin;
        sc->sc_uhidev = uca->uhidev;
        sc->sc_ibufsize = uca->ibufsize;
        sc->sc_ibufsizepad = uca->ibufsizepad;
        sc->sc_obufsize = uca->obufsize;
        sc->sc_opkthdrlen = uca->opkthdrlen;
        sc->sc_methods = uca->methods;
        sc->sc_parent = uca->arg;
        sc->sc_portno = uca->portno;

        if (usbd_get_location(sc->sc_uparent, sc->sc_iface, &bus, &route,
            &ifaceno) == 0) {
                if (snprintf(path, sizeof(path), "usb%u.%u.%05x.%u", bus,
                    ROUTEROOTPORT(route), ROUTESTRING(route), ifaceno) <
                    sizeof(path))
                        printf(": %s", path);
        }
        printf("\n");

        tp = ttymalloc(1000000);
        tp->t_oproc = ucomstart;
        tp->t_param = ucomparam;
        sc->sc_tty = tp;
        sc->sc_cua = 0;

        ucom_change = 1;
        rw_init(&sc->sc_lock, "ucomlk");
}

int
ucom_detach(struct device *self, int flags)
{
        struct ucom_softc *sc = (struct ucom_softc *)self;
        struct tty *tp = sc->sc_tty;
        int maj, mn;
        int s;

        DPRINTF(("ucom_detach: sc=%p flags=%d tp=%p, pipe=%d,%d\n",
                 sc, flags, tp, sc->sc_bulkin_no, sc->sc_bulkout_no));

        if (sc->sc_bulkin_pipe != NULL) {
                usbd_close_pipe(sc->sc_bulkin_pipe);
                sc->sc_bulkin_pipe = NULL;
        }
        if (sc->sc_bulkout_pipe != NULL) {
                usbd_close_pipe(sc->sc_bulkout_pipe);
                sc->sc_bulkout_pipe = NULL;
        }
        if (sc->sc_ixfer != NULL) {
                if (sc->sc_bulkin_no != -1) {
                        usbd_free_buffer(sc->sc_ixfer);
                        sc->sc_ibuf = NULL;
                        usbd_free_xfer(sc->sc_ixfer);
                }
                sc->sc_ixfer = NULL;
        }
        if (sc->sc_oxfer != NULL) {
                usbd_free_buffer(sc->sc_oxfer);
                sc->sc_obuf = NULL;
                if (sc->sc_bulkin_no != -1)
                        usbd_free_xfer(sc->sc_oxfer);
                sc->sc_oxfer = NULL;
        }

        s = splusb();
        if (--sc->sc_refcnt >= 0) {
                /* Wake up anyone waiting */
                if (tp != NULL) {
                        CLR(tp->t_state, TS_CARR_ON);
                        CLR(tp->t_cflag, CLOCAL | MDMBUF);
                        ttyflush(tp, FREAD|FWRITE);
                }
                usb_detach_wait(&sc->sc_dev);
        }
        splx(s);

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

        /* Nuke the vnodes for any open instances. */
        mn = self->dv_unit;
        DPRINTF(("ucom_detach: maj=%d mn=%d\n", maj, mn));
        vdevgone(maj, mn, mn, VCHR);
        vdevgone(maj, mn | UCOMCUA_MASK, mn | UCOMCUA_MASK, VCHR);

        /* Detach and free the tty. */
        if (tp != NULL) {
                (*LINESW(tp, l_close))(tp, FNONBLOCK, curproc);
                s = spltty();
                CLR(tp->t_state, TS_BUSY | TS_FLUSH);
                ttyclose(tp);
                splx(s);
                ttyfree(tp);
                sc->sc_tty = NULL;
        }

        ucom_change = 1;
        return (0);
}

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)) {
                ucom_dtr(sc, 0);
                ucom_rts(sc, 0);
                tsleep_nsec(sc, TTIPRI, ttclos, SEC_TO_NSEC(1));
        }
}

int
ucomopen(dev_t dev, int flag, int mode, struct proc *p)
{
        int unit = UCOMUNIT(dev);
        struct ucom_softc *sc;
        int error;

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

        sc->sc_error = 0;

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

        if (ISSET(sc->sc_dev.dv_flags, DVF_ACTIVE) == 0)
                return (ENXIO);

        sc->sc_refcnt++;
        error = ucom_do_open(dev, flag, mode, p);
        if (--sc->sc_refcnt < 0)
                usb_detach_wakeup(&sc->sc_dev);

        return (error);
}

int
ucom_do_open(dev_t dev, int flag, int mode, struct proc *p)
{
        struct ucom_softc *sc = ucom_cd.cd_devs[UCOMUNIT(dev)];
        usbd_status err;
        struct tty *tp;
        struct termios t;
        int error, s;

        /* open the pipes if this is the first open */
        ucom_lock(sc);
        s = splusb();
        if (sc->sc_open == 0) {
                DPRINTF(("ucomopen: open pipes in=%d out=%d\n",
                    sc->sc_bulkin_no, sc->sc_bulkout_no));
                DPRINTF(("ucomopen: hid %p pipes in=%p out=%p\n",
                    sc->sc_uhidev, sc->sc_ipipe, sc->sc_opipe));

                if (sc->sc_bulkin_no != -1) {

                        /* Open the bulk pipes */
                        err = usbd_open_pipe(sc->sc_iface, sc->sc_bulkin_no, 0,
                            &sc->sc_bulkin_pipe);
                        if (err) {
                                DPRINTF(("%s: open bulk out error (addr %d), err=%s\n",
                                    sc->sc_dev.dv_xname, sc->sc_bulkin_no,
                                    usbd_errstr(err)));
                                error = EIO;
                                goto fail_0;
                        }
                        err = usbd_open_pipe(sc->sc_iface, sc->sc_bulkout_no,
                            USBD_EXCLUSIVE_USE, &sc->sc_bulkout_pipe);
                        if (err) {
                                DPRINTF(("%s: open bulk in error (addr %d), err=%s\n",
                                    sc->sc_dev.dv_xname, 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_uparent);
                        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_2;
                        }

                        sc->sc_oxfer = usbd_alloc_xfer(sc->sc_uparent);
                        if (sc->sc_oxfer == NULL) {
                                error = ENOMEM;
                                goto fail_3;
                        }
                } else {
                        /*
                         * input/output pipes and xfers already allocated
                         * as is the input buffer.
                         */
                        sc->sc_ipipe = sc->sc_uhidev->sc_ipipe;
                        sc->sc_ixfer = sc->sc_uhidev->sc_ixfer;
                        sc->sc_opipe = sc->sc_uhidev->sc_opipe;
                        sc->sc_oxfer = sc->sc_uhidev->sc_oxfer;
                }

                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;
                }

                if (sc->sc_methods->ucom_open != NULL) {
                        error = sc->sc_methods->ucom_open(sc->sc_parent,
                            sc->sc_portno);
                        if (error) {
                                ucom_cleanup(sc);
                                splx(s);
                                ucom_unlock(sc);
                                return (error);
                        }
                }

                ucom_status_change(sc);

                ucomstartread(sc);
                sc->sc_open = 1;
        }
        splx(s);
        s = spltty();
        ucom_unlock(sc);
        tp = sc->sc_tty;
        splx(s);

        DPRINTF(("ucomopen: unit=%d, tp=%p\n", UCOMUNIT(dev), tp));

        tp->t_dev = dev;
        if (!ISSET(tp->t_state, TS_ISOPEN)) {
                SET(tp->t_state, TS_WOPEN);
                ttychars(tp);

                /*
                 * 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;
                if (ISSET(sc->sc_swflags, TIOCFLAG_CLOCAL))
                        SET(t.c_cflag, CLOCAL);
                if (ISSET(sc->sc_swflags, TIOCFLAG_CRTSCTS))
                        SET(t.c_cflag, CRTSCTS);
                if (ISSET(sc->sc_swflags, TIOCFLAG_MDMBUF))
                        SET(t.c_cflag, MDMBUF);

                /* 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;

                s = spltty();
                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.
                 */
                ucom_dtr(sc, 1);
                /* When not using CRTSCTS, RTS follows DTR. */
                if (!ISSET(t.c_cflag, CRTSCTS))
                        ucom_rts(sc, 1);

                /* XXX CLR(sc->sc_rx_flags, RX_ANY_BLOCK);*/
                ucom_hwiflow(sc);

                if (ISSET(sc->sc_swflags, TIOCFLAG_SOFTCAR) || UCOMCUA(dev) ||
                    ISSET(sc->sc_msr, UMSR_DCD) || ISSET(tp->t_cflag, MDMBUF))
                        SET(tp->t_state, TS_CARR_ON);
                else
                        CLR(tp->t_state, TS_CARR_ON);
        } else if (ISSET(tp->t_state, TS_XCLUDE) && suser(p) != 0)
                return (EBUSY);
        else
                s = spltty();

        if (UCOMCUA(dev)) {
                if (ISSET(tp->t_state, TS_ISOPEN)) {
                        /* Someone is already dialed in */
                        splx(s);
                        return (EBUSY);
                }
                sc->sc_cua = 1;
        } else {
                /* tty (not cua) device, wait for carrier */
                if (ISSET(flag, O_NONBLOCK)) {
                        if (sc->sc_cua) {
                                splx(s);
                                return (EBUSY);
                        }
                } else {
                        while (sc->sc_cua || (!ISSET(tp->t_cflag, CLOCAL) &&
                            !ISSET(tp->t_state, TS_CARR_ON))) {
                                SET(tp->t_state, TS_WOPEN);
                                error = ttysleep(tp, &tp->t_rawq,
                                    TTIPRI | PCATCH, ttopen);

                                if (usbd_is_dying(sc->sc_uparent)) {
                                        splx(s);
                                        return (EIO);
                                }

                                /*
                                 * If TS_WOPEN has been reset, that means the
                                 * cua device has been closed.  We don't want
                                 * to fail in that case, so just go around
                                 * again.
                                 */
                                if (error && ISSET(tp->t_state, TS_WOPEN)) {
                                        CLR(tp->t_state, TS_WOPEN);
                                        splx(s);
                                        goto bad;
                                }
                        }
                }
        }
        splx(s);

        error = (*LINESW(tp, l_open))(dev, tp, p);
        if (error)
                goto bad;

        return (0);

fail_4:
        if (sc->sc_bulkin_no != -1)
                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:
        splx(s);
        ucom_unlock(sc);
        return (error);

bad:
        ucom_lock(sc);
        ucom_cleanup(sc);
        ucom_unlock(sc);

        return (error);
}

int
ucomclose(dev_t dev, int flag, int mode, struct proc *p)
{
        struct ucom_softc *sc = ucom_cd.cd_devs[UCOMUNIT(dev)];
        int error;

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

        DPRINTF(("ucomclose: unit=%d\n", UCOMUNIT(dev)));

        sc->sc_refcnt++;
        error = ucom_do_close(sc, flag, mode, p);
        if (--sc->sc_refcnt < 0)
                usb_detach_wakeup(&sc->sc_dev);

        return (error);
}

int
ucom_do_close(struct ucom_softc *sc, int flag, int mode, struct proc *p)
{
        struct tty *tp = sc->sc_tty;
        int s;

        if (!ISSET(tp->t_state, TS_ISOPEN))
                return (0);

        ucom_lock(sc);

        (*LINESW(tp, l_close))(tp, flag, p);
        s = spltty();
        CLR(tp->t_state, TS_BUSY | TS_FLUSH);
        sc->sc_cua = 0;
        ttyclose(tp);
        splx(s);
        ucom_cleanup(sc);

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

        ucom_unlock(sc);

        return (0);
}

int
ucomread(dev_t dev, struct uio *uio, int flag)
{
        struct ucom_softc *sc = ucom_cd.cd_devs[UCOMUNIT(dev)];
        struct tty *tp;
        int error;

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

        if (sc->sc_error)
                return (sc->sc_error);

        sc->sc_refcnt++;
        tp = sc->sc_tty;
        error = (*LINESW(tp, l_read))(tp, uio, flag);
        if (--sc->sc_refcnt < 0)
                usb_detach_wakeup(&sc->sc_dev);
        return (error);
}

int
ucomwrite(dev_t dev, struct uio *uio, int flag)
{
        struct ucom_softc *sc = ucom_cd.cd_devs[UCOMUNIT(dev)];
        struct tty *tp;
        int error;

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

        sc->sc_refcnt++;
        tp = sc->sc_tty;
        error = (*LINESW(tp, l_write))(tp, uio, flag);
        if (--sc->sc_refcnt < 0)
                usb_detach_wakeup(&sc->sc_dev);
        return (error);
}

struct tty *
ucomtty(dev_t dev)
{
        struct ucom_softc *sc = ucom_cd.cd_devs[UCOMUNIT(dev)];

        /*
         * Return a pointer to our tty even if the device is dying
         * in order to properly close it in the detach routine.
         */
        if (sc == NULL)
                return (NULL);

        return (sc->sc_tty);
}

int
ucomioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct proc *p)
{
        struct ucom_softc *sc = ucom_cd.cd_devs[UCOMUNIT(dev)];
        int error;

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

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

int
ucom_do_ioctl(struct ucom_softc *sc, u_long cmd, caddr_t data,
              int flag, struct proc *p)
{
        struct tty *tp = sc->sc_tty;
        int error;
        int s;

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

        error = (*LINESW(tp, l_ioctl))(tp, cmd, data, flag, p);
        if (error >= 0)
                return (error);

        error = ttioctl(tp, cmd, data, flag, p);
        if (error >= 0)
                return (error);

        if (sc->sc_methods->ucom_ioctl != NULL) {
                error = sc->sc_methods->ucom_ioctl(sc->sc_parent,
                            sc->sc_portno, cmd, data, flag, p);
                if (error != ENOTTY)
                        return (error);
        }

        error = 0;

        DPRINTF(("ucomioctl: our cmd=0x%08lx\n", cmd));
        s = spltty();

        switch (cmd) {
        case TIOCSBRK:
                ucom_break(sc, 1);
                break;

        case TIOCCBRK:
                ucom_break(sc, 0);
                break;

        case TIOCSDTR:
                ucom_dtr(sc, 1);
                break;

        case TIOCCDTR:
                ucom_dtr(sc, 0);
                break;

        case TIOCGFLAGS:
                *(int *)data = sc->sc_swflags;
                break;

        case TIOCSFLAGS:
                error = suser(p);
                if (error)
                        break;
                sc->sc_swflags = *(int *)data;
                break;

        case TIOCMSET:
        case TIOCMBIS:
        case TIOCMBIC:
                tiocm_to_ucom(sc, cmd, *(int *)data);
                break;

        case TIOCMGET:
                *(int *)data = ucom_to_tiocm(sc);
                break;

        default:
                error = ENOTTY;
                break;
        }

        splx(s);

        return (error);
}

void
tiocm_to_ucom(struct ucom_softc *sc, u_long how, int ttybits)
{
        u_char combits;

        combits = 0;
        if (ISSET(ttybits, TIOCM_DTR))
                SET(combits, UMCR_DTR);
        if (ISSET(ttybits, TIOCM_RTS))
                SET(combits, UMCR_RTS);

        switch (how) {
        case TIOCMBIC:
                CLR(sc->sc_mcr, combits);
                break;

        case TIOCMBIS:
                SET(sc->sc_mcr, combits);
                break;

        case TIOCMSET:
                CLR(sc->sc_mcr, UMCR_DTR | UMCR_RTS);
                SET(sc->sc_mcr, combits);
                break;
        }

        if (how == TIOCMSET || ISSET(combits, UMCR_DTR))
                ucom_dtr(sc, (sc->sc_mcr & UMCR_DTR) != 0);
        if (how == TIOCMSET || ISSET(combits, UMCR_RTS))
                ucom_rts(sc, (sc->sc_mcr & UMCR_RTS) != 0);
}

int
ucom_to_tiocm(struct ucom_softc *sc)
{
        u_char combits;
        int ttybits = 0;

        combits = sc->sc_mcr;
        if (ISSET(combits, UMCR_DTR))
                SET(ttybits, TIOCM_DTR);
        if (ISSET(combits, UMCR_RTS))
                SET(ttybits, TIOCM_RTS);

        combits = sc->sc_msr;
        if (ISSET(combits, UMSR_DCD))
                SET(ttybits, TIOCM_CD);
        if (ISSET(combits, UMSR_CTS))
                SET(ttybits, TIOCM_CTS);
        if (ISSET(combits, UMSR_DSR))
                SET(ttybits, TIOCM_DSR);
        if (ISSET(combits, UMSR_RI | UMSR_TERI))
                SET(ttybits, TIOCM_RI);

#if 0
XXX;
        if (sc->sc_ier != 0)
                SET(ttybits, TIOCM_LE);
#endif

        return (ttybits);
}

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

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

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

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

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

        if (sc->sc_methods->ucom_set != NULL)
                sc->sc_methods->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;

        if (sc->sc_methods->ucom_get_status != NULL) {
                old_msr = sc->sc_msr;
                sc->sc_methods->ucom_get_status(sc->sc_parent, sc->sc_portno,
                    &sc->sc_lsr, &sc->sc_msr);

                ttytstamp(tp, old_msr & UMSR_CTS, sc->sc_msr & UMSR_CTS,
                    old_msr & UMSR_DCD, sc->sc_msr & UMSR_DCD);

                if (ISSET((sc->sc_msr ^ old_msr), UMSR_DCD))
                        (*LINESW(tp, l_modem))(tp,
                            ISSET(sc->sc_msr, UMSR_DCD));
        } else {
                sc->sc_lsr = 0;
                sc->sc_msr = 0;
        }
}

int
ucomparam(struct tty *tp, struct termios *t)
{
        struct ucom_softc *sc = ucom_cd.cd_devs[UCOMUNIT(tp->t_dev)];
        int error;

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

        /* Check requested parameters. */
        if (t->c_ispeed && t->c_ispeed != t->c_ospeed)
                return (EINVAL);

        /*
         * For the console, always force CLOCAL and !HUPCL, so that the port
         * is always active.
         */
        if (ISSET(sc->sc_swflags, TIOCFLAG_SOFTCAR)) {
                SET(t->c_cflag, CLOCAL);
                CLR(t->c_cflag, HUPCL);
        }

        /*
         * 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);

        /* XXX lcr = ISSET(sc->sc_lcr, LCR_SBREAK) | cflag2lcr(t->c_cflag); */

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

        /*
         * When not using CRTSCTS, RTS follows DTR.
         * This assumes that the ucom_param() call will enable these signals
         * for real.
         */
        if (!ISSET(t->c_cflag, CRTSCTS))
                sc->sc_mcr = UMCR_DTR | UMCR_RTS;
        else
                sc->sc_mcr = UMCR_DTR;

        if (sc->sc_methods->ucom_param != NULL) {
                error = sc->sc_methods->ucom_param(sc->sc_parent, sc->sc_portno,
                            t);
                if (error)
                        return (error);
        }

        /* XXX worry about CHWFLOW */

        /*
         * Update the tty layer's idea of the carrier bit, in case we changed
         * CLOCAL or MDMBUF.  We don't hang up here; we only do that by
         * explicit request.
         */
        DPRINTF(("ucomparam: l_modem\n"));
        (void) (*LINESW(tp, l_modem))(tp, 1 /* XXX carrier */ );

#if 0
XXX what if the hardware is not open
        if (!ISSET(t->c_cflag, CHWFLOW)) {
                if (sc->sc_tx_stopped) {
                        sc->sc_tx_stopped = 0;
                        ucomstart(tp);
                }
        }
#endif

        return (0);
}

/*
 * (un)block input via hw flowcontrol
 */
void
ucom_hwiflow(struct ucom_softc *sc)
{
        DPRINTF(("ucom_hwiflow:\n"));
#if 0
XXX
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;

        if (sc->sc_mcr_rts == 0)
                return;

        if (ISSET(sc->sc_rx_flags, RX_ANY_BLOCK)) {
                CLR(sc->sc_mcr, sc->sc_mcr_rts);
                CLR(sc->sc_mcr_active, sc->sc_mcr_rts);
        } else {
                SET(sc->sc_mcr, sc->sc_mcr_rts);
                SET(sc->sc_mcr_active, sc->sc_mcr_rts);
        }
        bus_space_write_1(iot, ioh, com_mcr, sc->sc_mcr_active);
#endif
}

void
ucomstart(struct tty *tp)
{
        struct ucom_softc *sc = ucom_cd.cd_devs[UCOMUNIT(tp->t_dev)];
        usbd_status err;
        int s;
        u_char *data;
        int cnt;

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

        s = spltty();
        if (ISSET(tp->t_state, TS_BUSY | TS_TIMEOUT | TS_TTSTOP)) {
                DPRINTFN(4,("ucomstart: no go, state=0x%x\n", tp->t_state));
                goto out;
        }
        if (sc->sc_tx_stopped)
                goto out;

        ttwakeupwr(tp);
        if (tp->t_outq.c_cc == 0)
                goto out;

        /* Grab the first contiguous region of buffer space. */
        data = tp->t_outq.c_cf;
        cnt = ndqb(&tp->t_outq, 0);

        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_methods->ucom_write != NULL)
                sc->sc_methods->ucom_write(sc->sc_parent, sc->sc_portno,
                                           sc->sc_obuf, data, &cnt);
        else
                memcpy(sc->sc_obuf, data, cnt);

        DPRINTFN(4,("ucomstart: %d chars\n", cnt));
#ifdef DIAGNOSTIC
        if (sc->sc_oxfer == NULL) {
                printf("ucomstart: null oxfer\n");
                goto out;
        }
#endif
        if (sc->sc_bulkout_pipe != NULL) {
                usbd_setup_xfer(sc->sc_oxfer, sc->sc_bulkout_pipe,
                    (void *)sc, sc->sc_obuf, cnt,
                    USBD_NO_COPY, USBD_NO_TIMEOUT, ucomwritecb);
        } else {
                usbd_setup_xfer(sc->sc_oxfer, sc->sc_opipe,
                    (void *)sc, sc->sc_obuf, cnt,
                    USBD_NO_COPY, USBD_NO_TIMEOUT, ucomwritecb);
        }
        /* What can we do on error? */
        err = usbd_transfer(sc->sc_oxfer);
#ifdef DIAGNOSTIC
        if (err != USBD_IN_PROGRESS)
                printf("ucomstart: err=%s\n", usbd_errstr(err));
#endif

out:
        splx(s);
}

int
ucomstop(struct tty *tp, int flag)
{
        DPRINTF(("ucomstop: flag=%d\n", flag));
#if 0
        /*struct ucom_softc *sc = ucom_cd.cd_devs[UCOMUNIT(tp->t_dev)];*/
        int s;

        s = spltty();
        if (ISSET(tp->t_state, TS_BUSY)) {
                DPRINTF(("ucomstop: XXX\n"));
                /* sc->sc_tx_stopped = 1; */
                if (!ISSET(tp->t_state, TS_TTSTOP))
                        SET(tp->t_state, TS_FLUSH);
        }
        splx(s);
#endif
        return (0);
}

void
ucomwritecb(struct usbd_xfer *xfer, void *p, usbd_status status)
{
        struct ucom_softc *sc = (struct ucom_softc *)p;
        struct tty *tp = sc->sc_tty;
        u_int32_t cc;
        int s;

        DPRINTFN(5,("ucomwritecb: %p %p status=%d\n", xfer, p, status));

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

        if (sc->sc_bulkin_pipe != NULL) {
                if (status) {
                        usbd_clear_endpoint_stall_async(sc->sc_bulkin_pipe);
                        /* XXX we should restart after some delay. */
                        goto error;
                }
                usbd_get_xfer_status(xfer, NULL, NULL, &cc, NULL);
        } else {
                usbd_get_xfer_status(xfer, NULL, NULL, &cc, NULL);
                // XXX above gives me wrong cc, no?
        }

        DPRINTFN(5,("ucomwritecb: cc=%d\n", cc));
        /* convert from USB bytes to tty bytes */
        cc -= sc->sc_opkthdrlen;

        s = spltty();
        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, l_start))(tp);
        splx(s);
        return;

error:
        s = spltty();
        CLR(tp->t_state, TS_BUSY);
        splx(s);
}

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

        DPRINTFN(5,("ucomstartread: start\n"));
#ifdef DIAGNOSTIC
        if (sc->sc_ixfer == NULL) {
                DPRINTF(("ucomstartread: null ixfer\n"));
                return (USBD_INVAL);
        }
#endif

        if (sc->sc_bulkin_pipe != NULL) {
                usbd_setup_xfer(sc->sc_ixfer, sc->sc_bulkin_pipe,
                        (void *)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);
}

void
ucomreadcb(struct usbd_xfer *xfer, void *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, l_rint);
        usbd_status err;
        u_int32_t cc;
        u_char *cp;
        int s;

        DPRINTFN(5,("ucomreadcb: status=%d\n", status));

        if (status == USBD_CANCELLED || status == USBD_IOERROR ||
            usbd_is_dying(sc->sc_uparent)) {
                DPRINTF(("ucomreadcb: dying\n"));
                /* Send something to wake upper layer */
                sc->sc_error = EIO;
                s = spltty();
                (*rint)('\n', tp);
                ttwakeup(tp);
                splx(s);
                return;
        }

        if (status) {
                if (sc->sc_bulkin_pipe != NULL) {
                        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);
        DPRINTFN(5,("ucomreadcb: got %d chars, tp=%p\n", cc, tp));
        if (sc->sc_methods->ucom_read != NULL)
                sc->sc_methods->ucom_read(sc->sc_parent, sc->sc_portno,
                                          &cp, &cc);

        s = spltty();
        /* 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? */
                        printf("%s: lost %d chars\n", sc->sc_dev.dv_xname,
                               cc);
                        break;
                }
        }
        splx(s);

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

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

        sc->sc_open = 0;

        ucom_shutdown(sc);
        if (sc->sc_bulkin_pipe != NULL) {
                usbd_close_pipe(sc->sc_bulkin_pipe);
                sc->sc_bulkin_pipe = NULL;
        }
        if (sc->sc_bulkout_pipe != NULL) {
                usbd_close_pipe(sc->sc_bulkout_pipe);
                sc->sc_bulkout_pipe = NULL;
        }
        if (sc->sc_ixfer != NULL) {
                if (sc->sc_bulkin_no != -1) {
                        usbd_free_buffer(sc->sc_ixfer);
                        sc->sc_ibuf = NULL;
                        usbd_free_xfer(sc->sc_ixfer);
                }
                sc->sc_ixfer = NULL;
        }
        if (sc->sc_oxfer != NULL) {
                usbd_free_buffer(sc->sc_oxfer);
                sc->sc_obuf = NULL;
                if (sc->sc_bulkin_no != -1)
                        usbd_free_xfer(sc->sc_oxfer);
                sc->sc_oxfer = NULL;
        }
}

/*
 * Update ucom names for export by sysctl.
 */
char *
sysctl_ucominit(void)
{
        static char *ucoms = NULL;
        static size_t ucomslen = 0;
        char name[64];  /* dv_xname + ":usb000.000.00000.000," */
        struct ucom_softc *sc;
        int rslt;
        unsigned int unit;
        uint32_t route;
        uint8_t bus, ifaceno;

        KERNEL_ASSERT_LOCKED();

        if (rw_enter(&sysctl_ucomlock, RW_WRITE|RW_INTR) != 0)
                return NULL;

        if (ucoms == NULL || ucom_change) {
                free(ucoms, M_SYSCTL, ucomslen);
                ucomslen = ucom_cd.cd_ndevs * sizeof(name);
                ucoms = malloc(ucomslen, M_SYSCTL, M_WAITOK | M_ZERO);
                for (unit = 0; unit < ucom_cd.cd_ndevs; unit++) {
                        sc = ucom_cd.cd_devs[unit];
                        if (sc == NULL || sc->sc_iface == NULL)
                                continue;
                        if (usbd_get_location(sc->sc_uparent, sc->sc_iface,
                            &bus, &route, &ifaceno) == -1)
                                continue;
                        rslt = snprintf(name, sizeof(name),
                            "%s:usb%u.%u.%05x.%u,", sc->sc_dev.dv_xname, bus,
                            ROUTEROOTPORT(route), ROUTESTRING(route), ifaceno);
                        if (rslt < sizeof(name) && (strlen(ucoms) + rslt) <
                            ucomslen)
                                strlcat(ucoms, name, ucomslen);
                }
        }

        /* Remove trailing ','. */
        if (strlen(ucoms))
                ucoms[strlen(ucoms) - 1] = '\0';

        rw_exit_write(&sysctl_ucomlock);

        return ucoms;
}
#endif  /* NUCOM > 0 */

int
ucomprint(void *aux, const char *pnp)
{
        struct ucom_attach_args *uca = aux;

        if (pnp)
                printf("ucom at %s", pnp);
        if (uca->portno != UCOM_UNK_PORTNO)
                printf(" portno %d", uca->portno);
        return (UNCONF);
}

int
ucomsubmatch(struct device *parent, void *match, void *aux)
{
        struct ucom_attach_args *uca = aux;
        struct cfdata *cf = match;

        if (uca->portno != UCOM_UNK_PORTNO &&
            cf->ucomcf_portno != UCOM_UNK_PORTNO &&
            cf->ucomcf_portno != uca->portno)
                return (0);
        return ((*cf->cf_attach->ca_match)(parent, cf, aux));
}