NetBSD/sys/dev/wscons/wsdisplay.c

/* $NetBSD: wsdisplay.c,v 1.4 1998/04/07 16:06:33 drochner Exp $ */

/*
 * Copyright (c) 1996, 1997 Christopher G. Demetriou.  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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Christopher G. Demetriou
 *	for the NetBSD Project.
 * 4. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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.
 */

static const char _copyright[] __attribute__ ((unused)) =
    "Copyright (c) 1996, 1997 Christopher G. Demetriou.  All rights reserved.";
static const char _rcsid[] __attribute__ ((unused)) =
    "$NetBSD: wsdisplay.c,v 1.4 1998/04/07 16:06:33 drochner Exp $";

#include <sys/param.h>
#include <sys/conf.h>
#include <sys/device.h>
#include <sys/ioctl.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/malloc.h>
#include <sys/syslog.h>
#include <sys/systm.h>
#include <sys/tty.h>
#include <sys/signalvar.h>
#include <sys/errno.h>
#include <sys/fcntl.h>

#include <dev/wscons/wsconsio.h>
#include <dev/wscons/wsdisplayvar.h>
#include <dev/wscons/wsemulvar.h>
#include <dev/wscons/wscons_callbacks.h>
#include <dev/cons.h>

struct wsdisplay_conf {
	const struct wsdisplay_emulops *emulops;
	void	*emulcookie;

	const struct wsscreen_descr *scrdata;

	const struct wsemul_ops *wsemul;
	void	*wsemulcookie;
};

struct wsscreen {
	struct wsdisplay_conf *scr_dconf;

	struct tty *scr_tty;
	int	scr_open;			/* is it open? */
	int	scr_graphics;			/* graphics mode? */
	int	scr_hold_screen;		/* hold tty output */

	struct wsdisplay_softc *sc;
};

struct wsscreen *wsscreen_attach __P((struct wsdisplay_softc *, int,
				      const char *,
				      const struct wsscreen_descr *, void *,
				      int, int));

#define WSDISPLAY_MAXSCREEN 8

struct wsdisplay_softc {
	struct device sc_dv;

	const struct wsdisplay_accessops *sc_accessops;
	void	*sc_accesscookie;

	struct wsscreen *sc_scr[WSDISPLAY_MAXSCREEN];
	struct wsscreen *sc_focus;

	int	sc_isconsole;
	struct device *sc_kbddv;
};

extern struct cfdriver wsdisplay_cd;

/* Autoconfiguration definitions. */
static int wsdisplay_emul_match __P((struct device *, struct cfdata *,
	    void *));
static void wsdisplay_emul_attach __P((struct device *, struct device *,
	    void *));
static int wsdisplay_noemul_match __P((struct device *, struct cfdata *,
	    void *));
static void wsdisplay_noemul_attach __P((struct device *, struct device *,
	    void *));

struct cfattach wsdisplay_emul_ca = {
	sizeof (struct wsdisplay_softc),
	wsdisplay_emul_match,
	wsdisplay_emul_attach,
};
 
struct cfattach wsdisplay_noemul_ca = {
	sizeof (struct wsdisplay_softc),
	wsdisplay_noemul_match,
	wsdisplay_noemul_attach,
};
 
/* Exported tty- and cdevsw-related functions. */
cdev_decl(wsdisplay);

static void wsdisplaystart __P((struct tty *));
static int wsdisplayparam __P((struct tty *, struct termios *));


/* Internal macros, functions, and variables. */
#define	SET(t, f)	(t) |= (f)
#define	CLR(t, f)	(t) &= ~(f)
#define	ISSET(t, f)	((t) & (f))

#define	WSDISPLAYUNIT(dev)	(minor(dev) >> 8)
#define	WSDISPLAYSCREEN(dev)	(minor(dev) & 0xff)
#define WSDISPLAYMINOR(unit, screen)	(((unit) << 8) | (screen))
#define	WSDISPLAYBURST		(OBUFSIZ - 1)

#define	WSSCREEN_HAS_EMULATOR(scr)	((scr)->scr_dconf->emulops != NULL)
#define	WSSCREEN_GRAPHICS_MODE(scr) \
	    (WSSCREEN_HAS_EMULATOR(scr) && (scr)->scr_graphics != 0)

static void wsdisplay_common_attach __P((struct wsdisplay_softc *sc,
	    int console, struct wsscreen_list *,
	    const struct wsdisplay_accessops *accessops,
	    void *accesscookie));

static int wsdisplay_internal_ioctl __P((struct wsdisplay_softc *sc,
					 struct wsscreen *,
					 u_long cmd, caddr_t data,
					 int flag, struct proc *p));

static int wsdisplay_console_initted;
static struct wsdisplay_softc *wsdisplay_console_device;
static struct wsdisplay_conf wsdisplay_console_conf;

static int wsdisplay_getc_dummy __P((dev_t));
static void wsdisplay_pollc_dummy __P((dev_t, int));

static struct consdev wsdisplay_cons = {
	NULL, NULL, wsdisplay_getc_dummy, wsdisplay_cnputc,
	wsdisplay_pollc_dummy, NODEV, CN_NORMAL
};

struct wsscreen *wsscreen_attach(sc, console, emul, type, cookie, ccol, crow)
	struct wsdisplay_softc *sc;
	int console;
	const char *emul;
	const struct wsscreen_descr *type;
	void *cookie;
	int ccol, crow;
{
	struct wsdisplay_conf *dconf;
	struct wsscreen *scr;

	scr = malloc(sizeof(struct wsscreen), M_DEVBUF, M_WAITOK);
	if (!scr)
		return (NULL);

	if (console) {
		dconf = &wsdisplay_console_conf;
		/*
		 * If there's an emulation, tell it about the callback argument.
		 * The other stuff is already there.
		 */
		if (dconf->wsemul != NULL)
			(*dconf->wsemul->attach)(1, 0, 0, 0, 0, scr);
	} else { /* not console */
		dconf = malloc(sizeof(struct wsdisplay_conf),
			       M_DEVBUF, M_NOWAIT);
		dconf->emulops = type->textops;
		dconf->emulcookie = cookie;
		if (dconf->emulops) {
			dconf->wsemul = wsemul_pick(emul);
			dconf->wsemulcookie =
			  (*dconf->wsemul->attach)(0, type, cookie,
						   ccol, crow, scr);
		} else
			dconf->wsemul = NULL;
		dconf->scrdata = type;
	}

	scr->scr_dconf = dconf;

	/*
	 * we allocate a tty even for those devices that don't have
	 * emulators, so that e.g. 'getty' can be safely run on the
	 * devices, and so that the interface provided by all wsdisplay
	 * devices is uniform.  This is a bit of a hack.
	 */
	scr->scr_tty = ttymalloc();
	tty_attach(scr->scr_tty);

	scr->scr_open = 0;
#if 0
	scr->scr_graphics =
	    type->textops ? WSDISPLAYIO_MODE_EMUL : WSDISPLAYIO_MODE_MAPPED;
#else /* XXX again, for getty */
	scr->scr_graphics = WSDISPLAYIO_MODE_EMUL;
#endif
	scr->scr_hold_screen = 0;
	scr->sc = sc;
	return (scr);
}

/*
 * Autoconfiguration functions.
 */
int
wsdisplay_emul_match(parent, match, aux)
	struct device *parent;
	struct cfdata *match;
	void *aux;
{
	struct wsemuldisplaydev_attach_args *ap = aux;

	if (match->wsemuldisplaydevcf_console !=
	    WSEMULDISPLAYDEVCF_CONSOLE_UNK) {
		/*
		 * If console-ness of device specified, either match
		 * exactly (at high priority), or fail.
		 */
		if (match->wsemuldisplaydevcf_console != 0 &&
		    ap->console != 0)
			return (10);
		else
			return (0);
	}

	/* If console-ness unspecified, it wins. */
	return (1);
}

void
wsdisplay_emul_attach(parent, self, aux)
	struct device *parent, *self;
	void *aux;
{
	struct wsdisplay_softc *sc = (struct wsdisplay_softc *)self;
	struct wsemuldisplaydev_attach_args *ap = aux;

	wsdisplay_common_attach(sc, ap->console, ap->scrdata,
				ap->accessops, ap->accesscookie);

	if (ap->console) {
		int maj;

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

		cn_tab->cn_dev = makedev(maj, WSDISPLAYMINOR(self->dv_unit, 0));
	}
}

/* Print function (for parent devices). */
int
wsemuldisplaydevprint(aux, pnp)
	void *aux;
	const char *pnp;
{
#if 0 /* -Wunused */
	struct wsemuldisplaydev_attach_args *ap = aux;
#endif

	if (pnp)
		printf("wsdisplay at %s", pnp);
#if 0 /* don't bother; it's ugly */
	printf(" console %d", ap->console);
#endif

	return (UNCONF);
}

int
wsdisplay_noemul_match(parent, match, aux)
	struct device *parent;
	struct cfdata *match;
	void *aux;
{
#if 0 /* -Wunused */
	struct wsdisplaydev_attach_args *ap = aux;
#endif

	/* Always match. */
	return (1);
}

void
wsdisplay_noemul_attach(parent, self, aux)
	struct device *parent, *self;
	void *aux;
{
	struct wsdisplay_softc *sc = (struct wsdisplay_softc *)self;
	struct wsdisplaydev_attach_args *ap = aux;

	wsdisplay_common_attach(sc, 0, NULL, ap->accessops, ap->accesscookie);
}

/* Print function (for parent devices). */
int
wsdisplaydevprint(aux, pnp)
	void *aux;
	const char *pnp;
{
#if 0 /* -Wunused */
	struct wsdisplaydev_attach_args *ap = aux;
#endif

	if (pnp)
		printf("wsdisplay at %s", pnp);

	return (UNCONF);
}

static void
wsdisplay_common_attach(sc, console, scrdata, accessops, accesscookie)
	struct wsdisplay_softc *sc;
	int console;
	struct wsscreen_list *scrdata;
	const struct wsdisplay_accessops *accessops;
	void *accesscookie;
{
	const struct wsscreen_descr *scr;
	int res, i = 0;

	if (console) {
		KASSERT(wsdisplay_console_initted);
		KASSERT(wsdisplay_console_device == NULL);

		sc->sc_scr[0] = wsscreen_attach(sc, 1, 0, 0, 0, 0, 0);
		wsdisplay_console_device = sc;

		printf(": console (%s, %s emulation)",
		       wsdisplay_console_conf.scrdata->name,
		       wsdisplay_console_conf.wsemul->name);

		i++;
	}

	printf("\n");

#if 1 /* XXX do this in ioctl() - user selects screen type and emulation */
	KASSERT(scrdata->nscreens > 0);
	scr = scrdata->screens[0];

	for (; i < WSDISPLAY_MAXSCREEN; i++) {
		void *cookie;
		int ccol, crow;

		res = ((*accessops->alloc_screen)(accesscookie, scr,
						  &cookie, &ccol, &crow));
		if (res)
			break;

		sc->sc_scr[i] = wsscreen_attach(sc, 0, 0, scr, cookie,
						ccol, crow);
	}
#endif

	sc->sc_focus = sc->sc_scr[0];

	sc->sc_accessops = accessops;
	sc->sc_accesscookie = accesscookie;

	sc->sc_isconsole = console;
	sc->sc_kbddv = NULL;

	wscons_glue_set_callback();
}

void
wsdisplay_cnattach(type, cookie, ccol, crow)
	const struct wsscreen_descr *type;
	void *cookie;
	int ccol, crow;
{
	const struct wsemul_ops *wsemul;

	KASSERT(!wsdisplay_console_initted);
	KASSERT(type->nrows > 0);
	KASSERT(type->ncols > 0);
	KASSERT(crow < type->nrows);
	KASSERT(ccol < type->ncols);

	wsdisplay_console_conf.emulops = type->textops;
	wsdisplay_console_conf.emulcookie = cookie;
	wsdisplay_console_conf.scrdata = type;

	wsemul = wsemul_pick(0); /* default */
	wsdisplay_console_conf.wsemul = wsemul;
	wsdisplay_console_conf.wsemulcookie = (*wsemul->cnattach)(type, cookie,
								  ccol, crow);

	cn_tab = &wsdisplay_cons;

	wsdisplay_console_initted = 1;
}

/*
 * Tty and cdevsw functions.
 */
int
wsdisplayopen(dev, flag, mode, p)
	dev_t dev;
	int flag, mode;
	struct proc *p;
{
	struct wsdisplay_softc *sc;
	struct tty *tp;
	int unit, newopen, error;
	struct wsscreen *scr;

	unit = WSDISPLAYUNIT(dev);
	if (unit >= wsdisplay_cd.cd_ndevs ||	/* make sure it was attached */
	    (sc = wsdisplay_cd.cd_devs[unit]) == NULL)
		return (ENXIO);

	scr = sc->sc_scr[WSDISPLAYSCREEN(dev)];
	if (!scr)
		return (ENXIO);

	tp = scr->scr_tty;
	tp->t_oproc = wsdisplaystart;
	tp->t_param = wsdisplayparam;
	tp->t_dev = dev;
	newopen = (tp->t_state & TS_ISOPEN) == 0;
	if (newopen) {
		ttychars(tp);
		tp->t_iflag = TTYDEF_IFLAG;
		tp->t_oflag = TTYDEF_OFLAG;
		tp->t_cflag = TTYDEF_CFLAG;
		tp->t_lflag = TTYDEF_LFLAG;
		tp->t_ispeed = tp->t_ospeed = TTYDEF_SPEED;
		wsdisplayparam(tp, &tp->t_termios);
		ttsetwater(tp);
	} else if ((tp->t_state & TS_XCLUDE) != 0 && p->p_ucred->cr_uid != 0)
		return EBUSY;
	tp->t_state |= TS_CARR_ON;

	error = ((*linesw[tp->t_line].l_open)(dev, tp));
	if (newopen && (error == 0)) {
		scr->scr_open = 1;

		/* set window sizes as appropriate, and reset the emulation */
		tp->t_winsize.ws_row = scr->scr_dconf->scrdata->nrows;
		tp->t_winsize.ws_col = scr->scr_dconf->scrdata->ncols;

		/* wsdisplay_set_emulation() */
	}
	return (error);
}

int
wsdisplayclose(dev, flag, mode, p)
	dev_t dev;
	int flag, mode;
	struct proc *p;
{
	struct wsdisplay_softc *sc;
	struct tty *tp;
	int unit;
	struct wsscreen *scr;

	unit = WSDISPLAYUNIT(dev);
	if (unit >= wsdisplay_cd.cd_ndevs ||	/* make sure it was attached */
	    (sc = wsdisplay_cd.cd_devs[unit]) == NULL)
		return (ENXIO);

	scr = sc->sc_scr[WSDISPLAYSCREEN(dev)];

	if (WSSCREEN_HAS_EMULATOR(scr)) {
		if (scr->scr_hold_screen) {
			int s;

			/* XXX RESET KEYBOARD LEDS, etc. */
			s = spltty();	/* avoid conflict with keyboard */
			wsdisplay_kbdholdscreen((struct device *)sc, 0);
			splx(s);
		}
		tp = scr->scr_tty;
		(*linesw[tp->t_line].l_close)(tp, flag);
		ttyclose(tp);
	}
	/* XXX RESET EMULATOR? */
#if 0
	scr->scr_graphics =
	    wsemul ? WSDISPLAYIO_MODE_EMUL : WSDISPLAYIO_MODE_MAPPED;
#else /* XXX for getty */
	scr->scr_graphics = WSDISPLAYIO_MODE_EMUL;
#endif
	if (sc->sc_kbddv != NULL)
		wskbd_set_translation(sc->sc_kbddv,
		    scr->scr_graphics == WSDISPLAYIO_MODE_EMUL);
	scr->scr_open = 0;

	return (0);
}

int
wsdisplayread(dev, uio, flag)
	dev_t dev;
	struct uio *uio;
	int flag;
{
	struct wsdisplay_softc *sc;
	struct tty *tp;
	int unit;
	struct wsscreen *scr;

	unit = WSDISPLAYUNIT(dev);
	if (unit >= wsdisplay_cd.cd_ndevs ||	/* make sure it was attached */
	    (sc = wsdisplay_cd.cd_devs[unit]) == NULL)
		return (ENXIO);

	scr = sc->sc_scr[WSDISPLAYSCREEN(dev)];

	if (WSSCREEN_GRAPHICS_MODE(scr))
		return (ENODEV);

	tp = scr->scr_tty;
	return ((*linesw[tp->t_line].l_read)(tp, uio, flag));
}

int
wsdisplaywrite(dev, uio, flag)
	dev_t dev;
	struct uio *uio;
	int flag;
{
	struct wsdisplay_softc *sc;
	struct tty *tp;
	int unit;
	struct wsscreen *scr;

	unit = WSDISPLAYUNIT(dev);
	if (unit >= wsdisplay_cd.cd_ndevs ||	/* make sure it was attached */
	    (sc = wsdisplay_cd.cd_devs[unit]) == NULL)
		return (ENXIO);

	scr = sc->sc_scr[WSDISPLAYSCREEN(dev)];

	if (WSSCREEN_GRAPHICS_MODE(scr))
		return (ENODEV);

	tp = scr->scr_tty;
	return ((*linesw[tp->t_line].l_write)(tp, uio, flag));
}

struct tty *
wsdisplaytty(dev)
	dev_t dev;
{
	struct wsdisplay_softc *sc;
	int unit;
	struct wsscreen *scr;

	unit = WSDISPLAYUNIT(dev);
	if (unit >= wsdisplay_cd.cd_ndevs ||	/* make sure it was attached */
	    (sc = wsdisplay_cd.cd_devs[unit]) == NULL)
		return (NULL);

	scr = sc->sc_scr[WSDISPLAYSCREEN(dev)];

	return (scr->scr_tty);
}

int
wsdisplayioctl(dev, cmd, data, flag, p)
	dev_t dev;
	u_long cmd;
	caddr_t data;
	int flag;
	struct proc *p;
{
	struct wsdisplay_softc *sc;
	struct tty *tp;
	int unit, error;
	struct wsscreen *scr;

	unit = WSDISPLAYUNIT(dev);
	if (unit >= wsdisplay_cd.cd_ndevs ||	/* make sure it was attached */
	    (sc = wsdisplay_cd.cd_devs[unit]) == NULL)
		return (ENXIO);

	scr = sc->sc_scr[WSDISPLAYSCREEN(dev)];

	if (!WSSCREEN_GRAPHICS_MODE(scr)) {
		tp = scr->scr_tty;

/* printf("disc\n"); */
		/* do the line discipline ioctls first */
		error = (*linesw[tp->t_line].l_ioctl)(tp, cmd, data, flag, p);
		if (error >= 0)
			return error;

/* printf("tty\n"); */
		/* then the tty ioctls */
		error = ttioctl(tp, cmd, data, flag, p);
		if (error >= 0)
			return error;
	}

	error = wsdisplay_internal_ioctl(sc, scr, cmd, data, flag, p);
	return (error != -1 ? error : ENOTTY);
}

int
wsdisplay_internal_ioctl(sc, scr, cmd, data, flag, p)
	struct wsdisplay_softc *sc;
	struct wsscreen *scr;
	u_long cmd;
	caddr_t data;
	int flag;
	struct proc *p;
{
	int error, flush;
	void *buf;

	if (!WSSCREEN_GRAPHICS_MODE(scr) && sc->sc_kbddv != NULL) {
		/* check ioctls for keyboard */
/* printf("kbdcallback\n"); */
		error = wskbd_displayioctl(sc->sc_kbddv, cmd, data, flag, p);
		if (error >= 0)
			return error;
	}

/* printf("display\n"); */
	switch (cmd) {
	case WSDISPLAYIO_GMODE:
		*(u_int *)data = scr->scr_graphics;
		return (0);

	case WSDISPLAYIO_SMODE:
		if (*(u_int *)data != WSDISPLAYIO_MODE_EMUL &&
		    *(u_int *)data != WSDISPLAYIO_MODE_MAPPED)
			return (EINVAL);
		flush = (scr->scr_graphics != *(u_int *)data);
		scr->scr_graphics = *(u_int *)data;
		if (sc->sc_kbddv != NULL)
			wskbd_set_translation(sc->sc_kbddv,
			    scr->scr_graphics == WSDISPLAYIO_MODE_EMUL);
		if (flush)
			ttyflush(scr->scr_tty, FREAD | FWRITE);
		return (0);

	case WSDISPLAYIO_SFONT:
#define d ((struct wsdisplay_font *)data)
		if (d->fontheight != scr->scr_dconf->scrdata->fontheight ||
		    d->fontwidth != scr->scr_dconf->scrdata->fontwidth)
			return (EINVAL);
		buf = malloc(d->fontheight * d->stride * d->numchars,
			     M_DEVBUF, M_WAITOK);
		error = copyin(d->data, buf,
			       d->fontheight * d->stride * d->numchars);
		if (error) {
			free(buf, M_DEVBUF);
			return (error);
		}
		error =
		  (*sc->sc_accessops->load_font)(sc->sc_accesscookie,
						 scr->scr_dconf->emulcookie,
						 d->firstchar, d->numchars,
						 d->stride, buf);
		free(buf, M_DEVBUF);
#undef d
		return (error);
	}

	/* check ioctls for display */
	return ((*sc->sc_accessops->ioctl)(sc->sc_accesscookie, cmd, data,
	    flag, p));
}

int
wsdisplaymmap(dev, offset, prot)
	dev_t dev;
	int offset;		/* XXX */
	int prot;
{
	struct wsdisplay_softc *sc;
	int unit;

	unit = WSDISPLAYUNIT(dev);
	if (unit >= wsdisplay_cd.cd_ndevs ||	/* make sure it was attached */
	    (sc = wsdisplay_cd.cd_devs[unit]) == NULL)
		return (ENXIO);
#if 0
	if (!WSDISPLAY_GRAPHICS_MODE(sc) && 0)
		return (-1);
#endif
	/* pass mmap to display */
	return ((*sc->sc_accessops->mmap)(sc->sc_accesscookie, offset, prot));
}

int
wsdisplaypoll(dev, events, p)
	dev_t dev;
	int events;
	struct proc *p;
{
	struct wsdisplay_softc *sc = wsdisplay_cd.cd_devs[minor(dev)];
	struct wsscreen *scr;

	scr = sc->sc_scr[WSDISPLAYSCREEN(dev)];

	if (WSSCREEN_GRAPHICS_MODE(scr))
		return (0);
	else
		return (ttpoll(dev, events, p));
}

void
wsdisplaystart(tp)
	register struct tty *tp;
{
	struct wsdisplay_softc *sc;
	struct wsscreen *scr;
	register int s, n;
	u_char buf[WSDISPLAYBURST];
		
	s = spltty();
	if (tp->t_state & (TS_TIMEOUT | TS_BUSY | TS_TTSTOP)) {
		splx(s);
		return;
	}
	sc = wsdisplay_cd.cd_devs[WSDISPLAYUNIT(tp->t_dev)];
	scr = sc->sc_scr[WSDISPLAYSCREEN(tp->t_dev)];
	if (scr->scr_hold_screen) {
		tp->t_state |= TS_TIMEOUT;
		splx(s);
		return;
	}
	tp->t_state |= TS_BUSY; 
	splx(s);
	
	n = q_to_b(&tp->t_outq, buf, sizeof(buf));

	if (WSSCREEN_HAS_EMULATOR(scr))
		(*scr->scr_dconf->wsemul->output)(scr->scr_dconf->wsemulcookie,
		    buf, n);

	s = spltty();
	tp->t_state &= ~TS_BUSY;
	/* Come back if there's more to do */
	if (tp->t_outq.c_cc) {
		tp->t_state |= TS_TIMEOUT;
		timeout(ttrstrt, tp, (hz > 128) ? (hz / 128) : 1);
	}
	if (tp->t_outq.c_cc <= tp->t_lowat) {
		if (tp->t_state&TS_ASLEEP) {
			tp->t_state &= ~TS_ASLEEP;
			wakeup((caddr_t)&tp->t_outq);
		}
		selwakeup(&tp->t_wsel);
	}
	splx(s);
}

void
wsdisplaystop(tp, flag)
	struct tty *tp;
	int flag;
{
	int s;

	s = spltty();
	if (ISSET(tp->t_state, TS_BUSY))
		if (!ISSET(tp->t_state, TS_TTSTOP))
			SET(tp->t_state, TS_FLUSH);
	splx(s);
}

/* Set line parameters. */
int
wsdisplayparam(tp, t)
	struct tty *tp;
	struct termios *t;
{

	tp->t_ispeed = t->c_ispeed;
	tp->t_ospeed = t->c_ospeed;
	tp->t_cflag = t->c_cflag;
	return 0;
}

/*
 * Callbacks for the emulation code.
 */
void
wsdisplay_emulbell(v)
	void *v;
{
	struct wsscreen *scr = v;

	if (scr == NULL)		/* console, before real attach */
		return;

	if (WSSCREEN_GRAPHICS_MODE(scr)) /* can this happen? */
		return;

	(void) wsdisplay_internal_ioctl(scr->sc, scr, WSKBDIO_BELL, NULL,
					FWRITE, NULL);
}

void
wsdisplay_emulinput(v, data, count)
	void *v;
	const u_char *data;
	u_int count;
{
	struct wsscreen *scr = v;
	struct tty *tp;

	if (v == NULL)			/* console, before real attach */
		return;

	if (WSSCREEN_GRAPHICS_MODE(scr)) /* XXX can't happen */
		return;

	tp = scr->scr_tty;
	while (count-- > 0)
		(*linesw[tp->t_line].l_rint)(*data++, tp);
};

/*
 * Calls from the keyboard interface.
 */
void
wsdisplay_kbdinput(dev, data, count)
	struct device *dev;
	const u_char *data;
	u_int count;
{
	struct wsdisplay_softc *sc = (struct wsdisplay_softc *)dev;
	struct wsscreen *scr;
	struct tty *tp;

	KASSERT(sc != NULL);
	scr = sc->sc_focus;

	KASSERT(scr != NULL);

	if (WSSCREEN_GRAPHICS_MODE(scr))
		return;

	tp = scr->scr_tty;
	while (count-- > 0)
		(*linesw[tp->t_line].l_rint)(*data++, tp);
}

int
wsdisplay_switch(dev, no)
	struct device *dev;
	int no;
{
	struct wsdisplay_softc *sc = (struct wsdisplay_softc *)dev;
	struct wsscreen *ws;
	int s;

	if (no < 0 || no >= WSDISPLAY_MAXSCREEN)
		return (ENXIO);

	ws = sc->sc_scr[no];
	if (!ws)
		return (ENXIO);

	s = spltty();

	(*sc->sc_accessops->show_screen)(sc->sc_accesscookie,
					 ws->scr_dconf->emulcookie);
	sc->sc_focus = ws;
	/* keyboard state??? */

	splx(s);

	return (0);
}

void
wsdisplay_kbdholdscreen(dev, hold)
	struct device *dev;
	int hold;
{
	struct wsdisplay_softc *sc = (struct wsdisplay_softc *)dev;
	struct wsscreen *scr;

	scr = sc->sc_focus;

	if (hold)
		scr->scr_hold_screen = 1;
	else {
		scr->scr_hold_screen = 0;
		timeout(ttrstrt, scr->scr_tty, 0);	/* "immediate" */
	}
}

/*
 * Calls from the glue code.
 */
int
wsdisplay_is_console(dv)
	struct device *dv;
{
	struct wsdisplay_softc *sc = (struct wsdisplay_softc *)dv;

	KASSERT(sc != NULL);
	return (sc->sc_isconsole);
}

int
wsdisplay_has_emulator(dv)
	struct device *dv;
{
	struct wsdisplay_softc *sc = (struct wsdisplay_softc *)dv;
	struct wsscreen *scr;

	scr = sc->sc_focus; /* ??? */

	KASSERT(sc != NULL);
	KASSERT(scr != NULL);
	return (WSSCREEN_HAS_EMULATOR(scr)); /* XXX XXX */
}

struct device *
wsdisplay_kbd(dv)
	struct device *dv;
{
	struct wsdisplay_softc *sc = (struct wsdisplay_softc *)dv;

	KASSERT(sc != NULL);
	return (sc->sc_kbddv);
}

void
wsdisplay_set_kbd(dv, kbddv)
	struct device *dv, *kbddv;
{
	struct wsdisplay_softc *sc = (struct wsdisplay_softc *)dv;

	KASSERT(sc != NULL);
	sc->sc_kbddv = kbddv;
}

/*
 * Console interface.
 */
void
wsdisplay_cnputc(dev, i)
	dev_t dev;
	int i;
{
	struct wsdisplay_conf *dc;
	char c = i;

	if (!wsdisplay_console_initted)
		return;

	if (wsdisplay_console_device != NULL &&
	    WSSCREEN_GRAPHICS_MODE(wsdisplay_console_device->sc_scr[0]))
		return;

	dc = &wsdisplay_console_conf;
	(*dc->wsemul->output)(dc->wsemulcookie, &c, 1);
}

static int
wsdisplay_getc_dummy(dev)
	dev_t dev;
{
	/* panic? */
	return (0);
}

static void
wsdisplay_pollc_dummy(dev, on)
	dev_t dev;
	int on;
{
}

void
wsdisplay_set_cons_kbd(get, poll)
	int (*get) __P((dev_t));
	void (*poll) __P((dev_t, int));
{
	wsdisplay_cons.cn_getc = get;
	wsdisplay_cons.cn_pollc = poll;
}