/*      $NetBSD: wsmux.c,v 1.69 2025/11/22 15:39:23 riastradh Exp $     */

/*
 * Copyright (c) 1998, 2005 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * Author: Lennart Augustsson <lennart@augustsson.net>
 *         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.
 */

/*
 * wscons mux device.
 *
 * The mux device is a collection of real mice and keyboards and acts as
 * a merge point for all the events from the different real devices.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: wsmux.c,v 1.69 2025/11/22 15:39:23 riastradh Exp $");

#ifdef _KERNEL_OPT
#include "opt_compat_netbsd.h"
#include "opt_modular.h"
#endif

#include "wsdisplay.h"
#include "wsmux.h"
#include "wskbd.h"
#include "wsmouse.h"

#include <sys/param.h>
#include <sys/conf.h>
#include <sys/ioctl.h>
#include <sys/poll.h>
#include <sys/fcntl.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/proc.h>
#include <sys/queue.h>
#include <sys/syslog.h>
#include <sys/systm.h>
#include <sys/tty.h>
#include <sys/signalvar.h>
#include <sys/device.h>
#include <sys/device_impl.h>    /* XXX autoconf abuse */

#include "opt_wsdisplay_compat.h"

#include <dev/wscons/wsconsio.h>
#include <dev/wscons/wsksymdef.h>
#include <dev/wscons/wseventvar.h>
#include <dev/wscons/wscons_callbacks.h>
#include <dev/wscons/wsmuxvar.h>

#include "ioconf.h"

#ifdef WSMUX_DEBUG
#define DPRINTF(x)      if (wsmuxdebug) printf x
#define DPRINTFN(n,x)   if (wsmuxdebug > (n)) printf x
int     wsmuxdebug = 0;
#else
#define DPRINTF(x)
#define DPRINTFN(n,x)
#endif

/*
 * The wsmux pseudo device is used to multiplex events from several wsmouse,
 * wskbd, and/or wsmux devices together.
 * The devices connected together form a tree with muxes in the interior
 * and real devices (mouse and kbd) at the leaves.  The special case of
 * a tree with one node (mux or other) is supported as well.
 * Only the device at the root of the tree can be opened (if a non-root
 * device is opened the subtree rooted at that point is severed from the
 * containing tree).  When the root is opened it allocates a wseventvar
 * struct which all the nodes in the tree will send their events too.
 * An ioctl() performed on the root is propagated to all the nodes.
 * There are also ioctl() operations to add and remove nodes from a tree.
 */

static int wsmux_mux_open(struct wsevsrc *, struct wseventvar *);
static int wsmux_mux_close(struct wsevsrc *);

static void wsmux_do_open(struct wsmux_softc *, struct wseventvar *);

static void wsmux_do_close(struct wsmux_softc *);
#if NWSDISPLAY > 0
static int wsmux_evsrc_set_display(device_t, struct wsevsrc *);
#else
#define wsmux_evsrc_set_display NULL
#endif

static int wsmux_do_displayioctl(device_t dev, u_long cmd,
                                 void *data, int flag, struct lwp *l);
static int wsmux_do_ioctl(device_t, u_long, void *,int,struct lwp *);

static int wsmux_add_mux(int, struct wsmux_softc *);

#define WSMUXDEV(n) ((n) & 0x7f)
#define WSMUXCTL(n) ((n) & 0x80)

dev_type_open(wsmuxopen);
dev_type_close(wsmuxclose);
dev_type_read(wsmuxread);
dev_type_ioctl(wsmuxioctl);
dev_type_poll(wsmuxpoll);
dev_type_kqfilter(wsmuxkqfilter);

const struct cdevsw wsmux_cdevsw = {
        .d_open = wsmuxopen,
        .d_close = wsmuxclose,
        .d_read = wsmuxread,
        .d_write = nowrite,
        .d_ioctl = wsmuxioctl,
        .d_stop = nostop,
        .d_tty = notty,
        .d_poll = wsmuxpoll,
        .d_mmap = nommap,
        .d_kqfilter = wsmuxkqfilter,
        .d_discard = nodiscard,
        .d_flag = D_OTHER
};

struct wssrcops wsmux_srcops = {
        WSMUX_MUX,
        wsmux_mux_open, wsmux_mux_close, wsmux_do_ioctl, wsmux_do_displayioctl,
        wsmux_evsrc_set_display
};

/* From upper level */
void
wsmuxattach(int n)
{
}

/* Keep track of all muxes that have been allocated */
static struct wsmux_softc **wsmuxdevs = NULL;
static int nwsmux = 0;

/* Return mux n, create if necessary */
struct wsmux_softc *
wsmux_getmux(int n)
{
        struct wsmux_softc *sc;

        n = WSMUXDEV(n);        /* limit range */

        /* Make sure there is room for mux n in the table */
        if (n >= nwsmux) {
                void *new;

                new = realloc(wsmuxdevs, (n + 1) * sizeof(*wsmuxdevs),
                    M_DEVBUF, M_ZERO | M_WAITOK);
                wsmuxdevs = new;
                nwsmux = n + 1;
        }

        sc = wsmuxdevs[n];
        if (sc == NULL) {
                sc = wsmux_create("wsmux", n);
                wsmuxdevs[n] = sc;
        }
        return (sc);
}

/*
 * open() of the pseudo device from device table.
 */
int
wsmuxopen(dev_t dev, int flags, int mode, struct lwp *l)
{
        struct wsmux_softc *sc;
        struct wseventvar *evar;
        int minr, unit;

        minr = minor(dev);
        unit = WSMUXDEV(minr);
        sc = wsmux_getmux(unit);
        if (sc == NULL)
                return (ENXIO);

        DPRINTF(("wsmuxopen: %s: sc=%p l=%p\n",
                 device_xname(sc->sc_base.me_dv), sc, l));

        if (WSMUXCTL(minr)) {
                /* This is the control device which does not allow reads. */
                if (flags & FREAD)
                        return (EINVAL);
                return (0);
        }
        if ((flags & (FREAD | FWRITE)) == FWRITE)
                /* Allow write only open */
                return (0);

        if (sc->sc_base.me_parent != NULL) {
                /* Grab the mux out of the greedy hands of the parent mux. */
                DPRINTF(("wsmuxopen: detach\n"));
                wsmux_detach_sc(&sc->sc_base);
        }

        if (sc->sc_base.me_evp != NULL)
                /* Already open. */
                return (EBUSY);

        evar = &sc->sc_base.me_evar;
        wsevent_init(evar, l->l_proc);
#ifdef WSDISPLAY_COMPAT_RAWKBD
        sc->sc_rawkbd = 0;
#endif

        wsmux_do_open(sc, evar);

        return (0);
}

/*
 * Open of a mux via the parent mux.
 */
int
wsmux_mux_open(struct wsevsrc *me, struct wseventvar *evar)
{
        struct wsmux_softc *sc = (struct wsmux_softc *)me;

        if (sc->sc_base.me_evp != NULL)
                return (EBUSY);

        KASSERTMSG(sc->sc_base.me_parent != NULL,
                "wsmux_mux_open: no parent\n");

        wsmux_do_open(sc, evar);

        return (0);
}

/* Common part of opening a mux. */
void
wsmux_do_open(struct wsmux_softc *sc, struct wseventvar *evar)
{
        struct wsevsrc *me;
        int error;

        sc->sc_base.me_evp = evar; /* remember event variable, mark as open */

        /* Open all children. */
        TAILQ_FOREACH(me, &sc->sc_cld, me_next) {
                DPRINTF(("wsmuxopen: %s: m=%p dev=%s\n",
                         device_xname(sc->sc_base.me_dv), me,
                         device_xname(me->me_dv)));

                if (me->me_evp != NULL) {
                        DPRINTF(("wsmuxopen: dev %s already in use\n",
                                device_xname(me->me_dv)));
                        continue;
                }

                KASSERTMSG(me->me_parent == sc,
                        "wsmux_do_open: bad child=%p\n", me);

                error = wsevsrc_open(me, evar);
                if (error) {
                        DPRINTF(("wsmuxopen: open failed %d\n", error));
                }
        }
}

/*
 * close() of the pseudo device from device table.
 */
int
wsmuxclose(dev_t dev, int flags, int mode,
    struct lwp *l)
{
        int minr = minor(dev);
        struct wsmux_softc *sc = wsmuxdevs[WSMUXDEV(minr)];
        struct wseventvar *evar = sc->sc_base.me_evp;

        if (WSMUXCTL(minr))
                /* control device */
                return (0);
        if (evar == NULL)
                /* Not open for read */
                return (0);

        wsmux_do_close(sc);
        sc->sc_base.me_evp = NULL;
        wsevent_fini(evar);
        return (0);
}

/*
 * Close of a mux via the parent mux.
 */
int
wsmux_mux_close(struct wsevsrc *me)
{
        wsmux_do_close((struct wsmux_softc *)me);
        me->me_evp = NULL;
        return (0);
}

/* Common part of closing a mux. */
void
wsmux_do_close(struct wsmux_softc *sc)
{
        struct wsevsrc *me;

        DPRINTF(("wsmuxclose: %s: sc=%p\n",
                 device_xname(sc->sc_base.me_dv), sc));

        /* Close all the children. */
        TAILQ_FOREACH(me, &sc->sc_cld, me_next) {
                DPRINTF(("wsmuxclose %s: m=%p dev=%s\n",
                         device_xname(sc->sc_base.me_dv), me,
                         device_xname(me->me_dv)));

                KASSERTMSG(me->me_parent == sc,
                        "wsmuxclose: bad child=%p\n", me);

                if (me->me_evp != sc->sc_base.me_evp) {
                        DPRINTF(("wsmuxclose: dev %s opened elsewhere\n",
                                device_xname(me->me_dv)));
                        continue;
                }

                (void)wsevsrc_close(me);
                me->me_evp = NULL;
        }
}

/*
 * read() of the pseudo device from device table.
 */
int
wsmuxread(dev_t dev, struct uio *uio, int flags)
{
        int minr = minor(dev);
        struct wsmux_softc *sc = wsmuxdevs[WSMUXDEV(minr)];
        struct wseventvar *evar;
        int error;

        if (WSMUXCTL(minr)) {
                /* control device */
                return (EINVAL);
        }

        evar = sc->sc_base.me_evp;
        KASSERTMSG(evar != NULL, "wsmuxread: not open\n");

        DPRINTFN(5,("wsmuxread: %s event read evar=%p\n",
                    device_xname(sc->sc_base.me_dv), evar));
        error = wsevent_read(evar, uio, flags);
        DPRINTFN(5,("wsmuxread: %s event read ==> error=%d\n",
                    device_xname(sc->sc_base.me_dv), error));
        return (error);
}

/*
 * ioctl of the pseudo device from device table.
 */
int
wsmuxioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
{
        int u = WSMUXDEV(minor(dev));

        return wsmux_do_ioctl(wsmuxdevs[u]->sc_base.me_dv, cmd, data, flag, l);
}

/*
 * ioctl of a mux via the parent mux, continuation of wsmuxioctl().
 */
int
wsmux_do_ioctl(device_t dv, u_long cmd, void *data, int flag,
               struct lwp *lwp)
{
        struct wsmux_softc *sc = device_private(dv);
        struct wsevsrc *me;
        int error, ok;
        int s, n;
        struct wseventvar *evar;
        struct wscons_event event;
        struct wsmux_device_list *l;

        DPRINTF(("wsmux_do_ioctl: %s: enter sc=%p, cmd=%08lx\n",
                 device_xname(sc->sc_base.me_dv), sc, cmd));

        switch (cmd) {
#if defined(COMPAT_50) || defined(MODULAR)
        case WSMUXIO_OINJECTEVENT:
#endif /* defined(COMPAT_50) || defined(MODULAR) */
        case WSMUXIO_INJECTEVENT:
                /* Inject an event, e.g., from moused. */
                DPRINTF(("%s: inject\n", device_xname(sc->sc_base.me_dv)));

                evar = sc->sc_base.me_evp;
                if (evar == NULL) {
                        /* No event sink, so ignore it. */
                        DPRINTF(("wsmux_do_ioctl: event ignored\n"));
                        return (0);
                }

                s = spltty();
                event.type = ((struct wscons_event *)data)->type;
                event.value = ((struct wscons_event *)data)->value;
                error = wsevent_inject(evar, &event, 1);
                splx(s);

                return error;
        case WSMUXIO_ADD_DEVICE:
#define d ((struct wsmux_device *)data)
                DPRINTF(("%s: add type=%d, no=%d\n",
                         device_xname(sc->sc_base.me_dv), d->type, d->idx));
                switch (d->type) {
#if NWSMOUSE > 0
                case WSMUX_MOUSE:
                        return (wsmouse_add_mux(d->idx, sc));
#endif
#if NWSKBD > 0
                case WSMUX_KBD:
                        return (wskbd_add_mux(d->idx, sc));
#endif
                case WSMUX_MUX:
                        return (wsmux_add_mux(d->idx, sc));
                case WSMUX_BELL:
                        return (wsbell_add_mux(d->idx, sc));
                default:
                        return (EINVAL);
                }
        case WSMUXIO_REMOVE_DEVICE:
                DPRINTF(("%s: rem type=%d, no=%d\n",
                         device_xname(sc->sc_base.me_dv), d->type, d->idx));
                /* Locate the device */
                TAILQ_FOREACH(me, &sc->sc_cld, me_next) {
                        if (me->me_ops->type == d->type &&
                            device_unit(me->me_dv) == d->idx) {
                                DPRINTF(("wsmux_do_ioctl: detach\n"));
                                wsmux_detach_sc(me);
                                return (0);
                        }
                }
                return (EINVAL);
#undef d

        case WSMUXIO_LIST_DEVICES:
                DPRINTF(("%s: list\n", device_xname(sc->sc_base.me_dv)));
                l = (struct wsmux_device_list *)data;
                n = 0;
                TAILQ_FOREACH(me, &sc->sc_cld, me_next) {
                        if (n >= WSMUX_MAXDEV)
                                break;
                        l->devices[n].type = me->me_ops->type;
                        l->devices[n].idx = device_unit(me->me_dv);
                        n++;
                }
                l->ndevices = n;
                return (0);
#ifdef WSDISPLAY_COMPAT_RAWKBD
        case WSKBDIO_SETMODE:
                sc->sc_rawkbd = *(int *)data;
                DPRINTF(("wsmux_do_ioctl: save rawkbd = %d\n", sc->sc_rawkbd));
                break;
#endif

        case WSKBDIO_SETVERSION:
        case WSMOUSEIO_SETVERSION:
        case WSDISPLAYIO_SETVERSION:
                DPRINTF(("%s: WSxxxIO_SETVERSION\n",
                        device_xname(sc->sc_base.me_dv)));
                evar = sc->sc_base.me_evp;
                if (evar == NULL)
                        return (EINVAL);
                return wsevent_setversion(evar, *(int *)data);

        case FIONBIO:
                DPRINTF(("%s: FIONBIO\n", device_xname(sc->sc_base.me_dv)));
                return (0);

        case FIOASYNC:
                DPRINTF(("%s: FIOASYNC\n", device_xname(sc->sc_base.me_dv)));
                evar = sc->sc_base.me_evp;
                if (evar == NULL)
                        return (EINVAL);
                evar->async = *(int *)data != 0;
                return (0);
        case FIOSETOWN:
                DPRINTF(("%s: FIOSETOWN\n", device_xname(sc->sc_base.me_dv)));
                evar = sc->sc_base.me_evp;
                if (evar == NULL)
                        return (EINVAL);
                if (-*(int *)data != evar->io->p_pgid
                    && *(int *)data != evar->io->p_pid)
                        return (EPERM);
                return (0);
        case TIOCSPGRP:
                DPRINTF(("%s: TIOCSPGRP\n", device_xname(sc->sc_base.me_dv)));
                evar = sc->sc_base.me_evp;
                if (evar == NULL)
                        return (EINVAL);
                if (*(int *)data != evar->io->p_pgid)
                        return (EPERM);
                return (0);
        default:
                DPRINTF(("%s: unknown\n", device_xname(sc->sc_base.me_dv)));
                break;
        }

        if (sc->sc_base.me_evp == NULL
#if NWSDISPLAY > 0
            && sc->sc_base.me_dispdv == NULL
#endif
            )
                return (EACCES);

        /* Return 0 if any of the ioctl() succeeds, otherwise the last error */
        error = 0;
        ok = 0;
        TAILQ_FOREACH(me, &sc->sc_cld, me_next) {
                /* XXX check evp? */
                KASSERTMSG(me->me_parent == sc,
                        "wsmux_do_ioctl: bad child %p\n", me);

                error = wsevsrc_ioctl(me, cmd, data, flag, lwp);
                DPRINTF(("wsmux_do_ioctl: %s: me=%p dev=%s ==> %d\n",
                         device_xname(sc->sc_base.me_dv), me,
                         device_xname(me->me_dv), error));
                if (!error)
                        ok = 1;
        }
        if (ok) {
                error = 0;
                if (cmd == WSKBDIO_SETENCODING) {
                        sc->sc_kbd_layout = *((kbd_t *)data);
                }

        }

        return (error);
}

/*
 * poll() of the pseudo device from device table.
 */
int
wsmuxpoll(dev_t dev, int events, struct lwp *l)
{
        int minr = minor(dev);
        struct wsmux_softc *sc = wsmuxdevs[WSMUXDEV(minr)];

        if (WSMUXCTL(minr)) {
                /* control device */
                return (0);
        }

        KASSERTMSG(sc->sc_base.me_evp != NULL, "wsmuxpoll: not open\n");

        return (wsevent_poll(sc->sc_base.me_evp, events, l));
}

/*
 * kqfilter() of the pseudo device from device table.
 */
int
wsmuxkqfilter(dev_t dev, struct knote *kn)
{
        int minr = minor(dev);
        struct wsmux_softc *sc = wsmuxdevs[WSMUXDEV(minr)];

        if (WSMUXCTL(minr)) {
                /* control device */
                return (1);
        }

        KASSERTMSG(sc->sc_base.me_evp != NULL, "wsmuxkqfilter: not open\n");

        return (wsevent_kqfilter(sc->sc_base.me_evp, kn));
}

/*
 * Add mux unit as a child to muxsc.
 */
int
wsmux_add_mux(int unit, struct wsmux_softc *muxsc)
{
        struct wsmux_softc *sc, *m;

        sc = wsmux_getmux(unit);
        if (sc == NULL)
                return (ENXIO);

        DPRINTF(("wsmux_add_mux: %s(%p) to %s(%p)\n",
                 device_xname(sc->sc_base.me_dv), sc,
                 device_xname(muxsc->sc_base.me_dv), muxsc));

        if (sc->sc_base.me_parent != NULL || sc->sc_base.me_evp != NULL)
                return (EBUSY);

        /* The mux we are adding must not be an ancestor of itself. */
        for (m = muxsc; m != NULL ; m = m->sc_base.me_parent)
                if (m == sc)
                        return (EINVAL);

        return (wsmux_attach_sc(muxsc, &sc->sc_base));
}

/* Create a new mux softc. */
struct wsmux_softc *
wsmux_create(const char *name, int unit)
{
        struct wsmux_softc *sc;

        /* XXX This is wrong -- should use autoconfiguration framework */

        DPRINTF(("wsmux_create: allocating\n"));
        sc = malloc(sizeof *sc, M_DEVBUF, M_WAITOK|M_ZERO);
        sc->sc_base.me_dv = malloc(sizeof(struct device), M_DEVBUF,
            M_WAITOK|M_ZERO);
        TAILQ_INIT(&sc->sc_cld);
        snprintf(sc->sc_base.me_dv->dv_xname,
            sizeof sc->sc_base.me_dv->dv_xname, "%s%d", name, unit);
        sc->sc_base.me_dv->dv_private = sc;
        sc->sc_base.me_dv->dv_unit = unit;
        sc->sc_base.me_ops = &wsmux_srcops;
        sc->sc_kbd_layout = KB_NONE;
        return (sc);
}

/* Attach me as a child to sc. */
int
wsmux_attach_sc(struct wsmux_softc *sc, struct wsevsrc *me)
{
        int error;

        if (sc == NULL)
                return (EINVAL);

        DPRINTF(("wsmux_attach_sc: %s(%p): type=%d\n",
                 device_xname(sc->sc_base.me_dv), sc, me->me_ops->type));

        /* This was checked in wsmux_add_mux() */
        KASSERT(me->me_parent == NULL);

        me->me_parent = sc;
        TAILQ_INSERT_TAIL(&sc->sc_cld, me, me_next);

        error = 0;
#if NWSDISPLAY > 0
        if (sc->sc_base.me_dispdv != NULL) {
                /* This is a display mux, so attach the new device to it. */
                DPRINTF(("wsmux_attach_sc: %s: set display %p\n",
                         device_xname(sc->sc_base.me_dv),
                         sc->sc_base.me_dispdv));
                if (me->me_ops->dsetdisplay != NULL) {
                        error = wsevsrc_set_display(me, &sc->sc_base);
                        /* Ignore that the console already has a display. */
                        if (error == EBUSY)
                                error = 0;
                        if (!error) {
#ifdef WSDISPLAY_COMPAT_RAWKBD
                                DPRINTF(("wsmux_attach_sc: %s set rawkbd=%d\n",
                                         device_xname(me->me_dv),
                                         sc->sc_rawkbd));
                                (void)wsevsrc_ioctl(me, WSKBDIO_SETMODE,
                                                    &sc->sc_rawkbd, 0, 0);
#endif
                                if (sc->sc_kbd_layout != KB_NONE)
                                        (void)wsevsrc_ioctl(me,
                                            WSKBDIO_SETENCODING,
                                            &sc->sc_kbd_layout, FWRITE, 0);
                        }
                }
        }
#endif
        if (sc->sc_base.me_evp != NULL) {
                /* Mux is open, so open the new subdevice */
                DPRINTF(("wsmux_attach_sc: %s: calling open of %s\n",
                         device_xname(sc->sc_base.me_dv),
                         device_xname(me->me_dv)));
                error = wsevsrc_open(me, sc->sc_base.me_evp);
        } else {
                DPRINTF(("wsmux_attach_sc: %s not open\n",
                         device_xname(sc->sc_base.me_dv)));
        }

        if (error) {
                me->me_parent = NULL;
                TAILQ_REMOVE(&sc->sc_cld, me, me_next);
        }

        DPRINTF(("wsmux_attach_sc: %s(%p) done, error=%d\n",
                 device_xname(sc->sc_base.me_dv), sc, error));
        return (error);
}

/* Remove me from the parent. */
void
wsmux_detach_sc(struct wsevsrc *me)
{
        struct wsmux_softc *sc = me->me_parent;

        DPRINTF(("wsmux_detach_sc: %s(%p) parent=%p\n",
                 device_xname(me->me_dv), me, sc));

        KASSERTMSG(sc != NULL, "wsmux_detach_sc: %s has no parent\n",
                device_xname(me->me_dv));

#if NWSDISPLAY > 0
        if (sc->sc_base.me_dispdv != NULL) {
                if (me->me_ops->dsetdisplay != NULL)
                        /* ignore error, there's nothing we can do */
                        (void)wsevsrc_set_display(me, NULL);
        } else
#endif
        if (me->me_evp != NULL) {
                DPRINTF(("wsmux_detach_sc: close\n"));
                /* mux device is open, so close multiplexee */
                (void)wsevsrc_close(me);
        }

        TAILQ_REMOVE(&sc->sc_cld, me, me_next);
        me->me_parent = NULL;

        DPRINTF(("wsmux_detach_sc: done sc=%p\n", sc));
}

/*
 * Display ioctl() of a mux via the parent mux.
 */
int
wsmux_do_displayioctl(device_t dv, u_long cmd, void *data, int flag,
                      struct lwp *l)
{
        struct wsmux_softc *sc = device_private(dv);
        struct wsevsrc *me;
        int error, ok;

        DPRINTF(("wsmux_displayioctl: %s: sc=%p, cmd=%08lx\n",
                 device_xname(sc->sc_base.me_dv), sc, cmd));

#ifdef WSDISPLAY_COMPAT_RAWKBD
        if (cmd == WSKBDIO_SETMODE) {
                sc->sc_rawkbd = *(int *)data;
                DPRINTF(("wsmux_displayioctl: rawkbd = %d\n", sc->sc_rawkbd));
        }
#endif

        /*
         * Return 0 if any of the ioctl() succeeds, otherwise the last error.
         * Return EPASSTHROUGH if no mux component accepts the ioctl.
         */
        error = EPASSTHROUGH;
        ok = 0;
        TAILQ_FOREACH(me, &sc->sc_cld, me_next) {
                DPRINTF(("wsmux_displayioctl: me=%p\n", me));

                KASSERTMSG(me->me_parent == sc,
                        "wsmux_displayioctl: bad child %p\n", me);

                if (me->me_ops->ddispioctl != NULL) {
                        error = wsevsrc_display_ioctl(me, cmd, data, flag, l);
                        DPRINTF(("wsmux_displayioctl: me=%p dev=%s ==> %d\n",
                                 me, device_xname(me->me_dv), error));
                        if (!error)
                                ok = 1;
                }
        }
        if (ok)
                error = 0;

        return (error);
}

#if NWSDISPLAY > 0
/*
 * Set display of a mux via the parent mux.
 */
int
wsmux_evsrc_set_display(device_t dv, struct wsevsrc *ame)
{
        struct wsmux_softc *muxsc = (struct wsmux_softc *)ame;
        struct wsmux_softc *sc = device_private(dv);
        device_t displaydv = muxsc ? muxsc->sc_base.me_dispdv : NULL;

        DPRINTF(("wsmux_set_display: %s: displaydv=%p\n",
                 device_xname(sc->sc_base.me_dv), displaydv));

        if (displaydv != NULL) {
                if (sc->sc_base.me_dispdv != NULL)
                        return (EBUSY);
        } else {
                if (sc->sc_base.me_dispdv == NULL)
                        return (ENXIO);
        }

        return wsmux_set_display(sc, displaydv);
}

int
wsmux_set_display(struct wsmux_softc *sc, device_t displaydv)
{
        device_t odisplaydv;
        struct wsevsrc *me;
        struct wsmux_softc *nsc = displaydv ? sc : NULL;
        int error, ok;

        odisplaydv = sc->sc_base.me_dispdv;
        sc->sc_base.me_dispdv = displaydv;

        if (displaydv)
                aprint_verbose_dev(sc->sc_base.me_dv, "connecting to %s\n",
                       device_xname(displaydv));
        ok = 0;
        error = 0;
        TAILQ_FOREACH(me, &sc->sc_cld,me_next) {
                KASSERTMSG(me->me_parent == sc,
                        "wsmux_set_display: bad child parent %p\n", me);

                if (me->me_ops->dsetdisplay != NULL) {
                        error = wsevsrc_set_display(me, &nsc->sc_base);
                        DPRINTF(("wsmux_set_display: m=%p dev=%s error=%d\n",
                                 me, device_xname(me->me_dv), error));
                        if (!error) {
                                ok = 1;
#ifdef WSDISPLAY_COMPAT_RAWKBD
                                DPRINTF(("wsmux_set_display: %s set rawkbd=%d\n",
                                         device_xname(me->me_dv), sc->sc_rawkbd));
                                (void)wsevsrc_ioctl(me, WSKBDIO_SETMODE,
                                                    &sc->sc_rawkbd, 0, 0);
#endif
                        }
                }
        }
        if (ok)
                error = 0;

        if (displaydv == NULL)
                aprint_verbose("%s: disconnecting from %s\n",
                       device_xname(sc->sc_base.me_dv),
                       device_xname(odisplaydv));

        return (error);
}
#endif /* NWSDISPLAY > 0 */