NetBSD/sys/arch/da30/dev/zs.c

/*	$NetBSD: zs.c,v 1.4 1994/10/26 02:33:32 cgd Exp $	*/

/*
 * Copyright (c) 1993 Paul Mackerras.
 * 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. The name of the author may not be used to endorse or promote products
 *    derived from this software withough 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.
 */
/*
 * Serial I/O via an SCC,
 * also support for SCSI interface interrupts.
 */
#include <sys/param.h>
#include <sys/conf.h>
#include <sys/ioctl.h>
#include <sys/proc.h>
#include <sys/user.h>
#include <sys/tty.h>
#include <sys/uio.h>
#include <sys/callout.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/syslog.h>
#include <sys/fcntl.h>
#include <sys/device.h>
#include <machine/cpu.h>
#include <dev/cons.h>
#include <da30/da30/isr.h>
#include <da30/da30/iio.h>
#include <da30/dev/scc.h>

#include "zs.h"
#if NZS > 0

#define PCLK_FREQ	8333333
#define NZSLINE		(NZS*2)

/*
 * The SCSI bus interface controller (SBIC) is connected to the
 * modem lines of this unit.
 */
#define SCSI_UNIT	3

#define RECV_BUF	512
#define ERROR_DET	0xed

#define TS_DRAIN	TS_FLUSH	/* waiting for output to drain */

#define splzs()		spl6()

struct zs {
    short		flags;		/* see below */
    char		rr0;		/* holds previous CTS, DCD state */
    unsigned char	imask;		/* mask for input chars */
    int			nzs_open;	/* # opens as /dev/zsn */
    int			nkbd_open;	/* # opens as a keyboard */
    int			gsp_unit;	/* unit to send kbd chars to */
    struct tty		*tty;		/* link to tty structure */
    struct sccregs	scc;		/* SCC shadow registers */
    u_char		*rcv_get;
    u_char		*rcv_put;
    u_char		*rcv_end;
    volatile int	rcv_count;
    int			rcv_len;
    char		*send_ptr;
    int			send_count;
    int			sent_count;
    volatile char	modem_state;
    volatile char	modem_change;
    volatile short	hflags;
    char		rcv_buf[RECV_BUF];
};

/* Bits in flags */
#define ZS_SIDEA	1
#define ZS_INITED	2
#define ZS_INTEN	4
#define ZS_RESET	8
#define ZS_SCSI		0x10
#define ZS_CONSOLE	0x20

/* Bits in hflags */
#define ZH_OBLOCK	1		/* output blocked by CTS */
#define ZH_SIRQ		2		/* soft interrupt request */
#define ZH_TXING	4		/* transmitter active */
#define ZH_RXOVF	8		/* receiver buffer overflow */

struct zssoftc {
    struct device	dev;
    struct isr		isr;
    struct zs		zs[2];
};

struct tty *zs_tty[NZSLINE];

struct termios zs_cons_termios;
int zs_cons_unit = 0;
int zs_is_console = 0;
struct sccregs *zs_cons_scc;

int	zsopen __P((dev_t, int, int, struct proc *));
void	zsstart __P((struct tty *));
int	zsparam __P((struct tty *, struct termios *));
int	zsirq __P((int unit));
void	zs_softint __P((void));

extern unsigned long sir_scsi;
struct zs *zs_scsi;
#define setsoftscsi()	setsoftint(sir_scsi)

unsigned long sir_zs;
void zs_softint();

#define zsunit(dev)	(minor(dev) >> 1)
#define zsside(dev)	(minor(dev) & 1)

/*
 * Autoconfiguration stuff.
 */
void zsattach __P((struct device *, struct device *, void *));
int  zsmatch __P((struct device *, struct cfdata *, void *));

struct cfdriver zscd = {
    NULL, "zs", zsmatch, zsattach, DV_TTY, sizeof(struct zssoftc), 0
};

int
zsmatch(parent, cf, args)
    struct device *parent;
    struct cfdata *cf;
    void *args;
{
    return !badbaddr((caddr_t) IIO_CFLOC_ADDR(cf));
}

void
zsattach(parent, self, args)
    struct device *parent, *self;
    void *args;
{
    struct zssoftc *dv;
    struct zs *zp, *zc;
    volatile struct scc *scc;

    iio_print(self->dv_cfdata);

    /* connect the interrupt */
    dv = (struct zssoftc *) self;
    dv->isr.isr_intr = zsirq;
    dv->isr.isr_arg = self->dv_unit;
    dv->isr.isr_ipl = IIO_CFLOC_LEVEL(self->dv_cfdata);
    isrlink(&dv->isr);

    zp = &dv->zs[0];
    scc = (volatile struct scc *) IIO_CFLOC_ADDR(self->dv_cfdata);

    if( zs_is_console && self->dv_unit == zsunit(zs_cons_unit) ){
	/* SCC is the console - it's already reset */
	zc = zp + zsside(zs_cons_unit);
	zc->scc = *zs_cons_scc;
	zs_cons_scc = &zc->scc;
	zc->flags |= ZS_CONSOLE;
    } else {
	/* reset the SCC */
	scc->cr = 0;
	scc->cr = 9;
	scc->cr = 0xC0;		/* hardware reset of SCC, both sides */
    }

    /* side A */
    zp->scc.s_adr = scc + 1;
    zp->flags |= ZS_SIDEA | ZS_RESET;

    /* side B */
    ++zp;
    zp->scc.s_adr = scc;
    zp->flags |= ZS_RESET;

    if( sir_zs == 0 )
	sir_zs = allocate_sir(zs_softint, 0);

    if( self->dv_unit == zsunit(SCSI_UNIT) ){
	zs_scsi = &dv->zs[zsside(SCSI_UNIT)];
	zs_scsi->flags |= ZS_SCSI;
    }
}

zs_ttydef(struct zs *zp)
{
    struct tty *tp = zp->tty;

    if( (zp->flags & ZS_CONSOLE) == 0 ){
	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;
    } else
	tp->t_termios = zs_cons_termios;
    ttychars(tp);
    ttsetwater(tp);
    tp->t_oproc = zsstart;
    tp->t_param = zsparam;

    zp->rcv_get = zp->rcv_buf;
    zp->rcv_put = zp->rcv_buf;
    zp->rcv_end = zp->rcv_buf + sizeof(zp->rcv_buf);
    zp->rcv_len = sizeof(zp->rcv_buf) / 2;
}

/* ARGSUSED */
zsopen(dev_t dev, int flag, int mode, struct proc *p)
{
    register struct tty *tp;
    int error;
    struct zs *zp;
    struct zssoftc *dv;

    if( zsunit(dev) > zscd.cd_ndevs
       || (dv = (struct zssoftc *) zscd.cd_devs[zsunit(dev)]) == NULL )
	return ENODEV;

    zp = &dv->zs[zsside(dev)];
    if( zp->tty == NULL ){
	zp->tty = ttymalloc();
	zs_ttydef(zp);
	if( minor(dev) < NZSLINE )
	    zs_tty[minor(dev)] = zp->tty;
    }
    tp = zp->tty;
    tp->t_dev = dev;

    if ((tp->t_state & TS_ISOPEN) == 0) {
	tp->t_state |= TS_WOPEN;
	zs_init(zp);
	if( (zp->modem_state & SCC_DCD) != 0 )
	    tp->t_state |= TS_CARR_ON;
    } else if (tp->t_state&TS_XCLUDE && p->p_ucred->cr_uid != 0)
	return (EBUSY);

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

    if( error == 0 )
	++zp->nzs_open;
    return error;
}

int
zsclose(dev, flag, mode, p)
    dev_t dev;
    int flag, mode;
    struct proc *p;
{
    struct zs *zp;
    struct tty *tp;
    struct zssoftc *dv;
    int s;

    if( zsunit(dev) > zscd.cd_ndevs
       || (dv = (struct zssoftc *) zscd.cd_devs[zsunit(dev)]) == NULL )
	return ENODEV;
    zp = &dv->zs[zsside(dev)];
    tp = zp->tty;

    if( zp->nkbd_open == 0){
	(*linesw[tp->t_line].l_close)(tp, flag);
	s = splzs();
	if( (tp->t_cflag & HUPCL) != 0 && (zp->flags & ZS_SCSI) == 0 ){
	    ZBIC(&zp->scc, 5, 0x82);	/* drop DTR, RTS */
	}
	ZBIC(&zp->scc, 3, 1);	/* disable receiver */
	splx(s);
	ttyclose(tp);
    }
    zp->nzs_open = 0;
    return(0);
}

/*ARGSUSED*/
zsread(dev, uio, flag)
    dev_t dev;
    struct uio *uio;
    int flag;
{
    struct zssoftc *dv = (struct zssoftc *) zscd.cd_devs[zsunit(dev)];
    struct zs *zp = &dv->zs[zsside(dev)];
    struct tty *tp = zp->tty;

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

/*ARGSUSED*/
zswrite(dev, uio, flag)
    dev_t dev;
    struct uio *uio;
    int flag;
{
    struct zssoftc *dv = (struct zssoftc *) zscd.cd_devs[zsunit(dev)];
    struct zs *zp = &dv->zs[zsside(dev)];
    struct tty *tp = zp->tty;

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

zsioctl(dev, cmd, data, flag, p)
    dev_t dev;
    caddr_t data;
    int cmd, flag;
    struct proc *p;
{
    struct zssoftc *dv = (struct zssoftc *) zscd.cd_devs[zsunit(dev)];
    struct zs *zp = &dv->zs[zsside(dev)];
    struct tty *tp = zp->tty;
    register struct sccregs *scc = &zp->scc;
    register int error, s;

    error = (*linesw[tp->t_line].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( (zp->flags & ZS_SCSI) != 0 )
	return ENOTTY;
    error = 0;
    s = splzs();
    switch( cmd ){
    case TIOCSDTR:
	ZBIS(scc, 5, 0x80);
	break;
    case TIOCCDTR:
	ZBIC(scc, 5, 0x80);
	break;
    case TIOCSBRK:
	splx(s);
	zs_drain(zp);
	s = splzs();
	ZBIS(scc, 5, 0x10);
	spltty();
	zs_unblock(tp);
	break;
    case TIOCCBRK:
	ZBIC(scc, 5, 0x10);
	break;
    case TIOCMGET:
	*(int *)data = zscc_mget(scc);
	break;
    case TIOCMSET:
	zscc_mset(scc, *(int *)data);
	zscc_mclr(scc, ~*(int *)data);
	break;
    case TIOCMBIS:
	zscc_mset(scc, *(int *)data);
	break;
    case TIOCMBIC:
	zscc_mclr(scc, *(int *)data);
	break;
    default:
	error = ENOTTY;
    }
    splx(s);
    return error;
}

zsparam(tp, t)
struct tty *tp;
struct termios *t;
{
    struct zssoftc *dv = (struct zssoftc *) zscd.cd_devs[zsunit(tp->t_dev)];
    struct zs *zp = &dv->zs[zsside(tp->t_dev)];
    register int s;

    zs_drain(zp);
    s = splzs();
    zp->imask = zscc_params(&zp->scc, t, !(zp->flags & ZS_SCSI));
    tp->t_ispeed = t->c_ispeed;
    tp->t_ospeed = t->c_ospeed;
    tp->t_cflag = t->c_cflag;
    if( (tp->t_cflag & CCTS_OFLOW) == 0 )
	zp->hflags &= ~ZH_OBLOCK;
    else if( (zp->modem_state & 0x20) == 0 && (zp->flags & ZS_SCSI) == 0 )
	zp->hflags |= ZH_OBLOCK;
    spltty();
    zs_unblock(tp);
    splx(s);
    return 0;
}

void
zsstart(tp)
struct tty *tp;
{
    struct zssoftc *dv = (struct zssoftc *) zscd.cd_devs[zsunit(tp->t_dev)];
    struct zs *zp = &dv->zs[zsside(tp->t_dev)];
    register int s, n;

    s = spltty();
    if( (tp->t_state & (TS_TIMEOUT|TS_BUSY|TS_TTSTOP|TS_DRAIN)) == 0 ){
	n = ndqb(&tp->t_outq, 0);
	if( n > 0 ){
	    tp->t_state |= TS_BUSY;
	    splzs();
	    zp->hflags |= ZH_TXING;
	    zp->send_ptr = tp->t_outq.c_cf;
	    zp->send_count = n;
	    zp->sent_count = 0;
	    zs_txint(zp);
	    spltty();
	}

    }
    splx(s);
}

zsstop(struct tty *tp, int flag)
{
    struct zssoftc *dv = (struct zssoftc *) zscd.cd_devs[zsunit(tp->t_dev)];
    struct zs *zp = &dv->zs[zsside(tp->t_dev)];
    int s, n;

    s = splzs();
    zp->send_count = 0;
    n = zp->sent_count;
    zp->sent_count = 0;
    if( (tp->t_state & TS_BUSY) != 0 && (flag & FWRITE) == 0 ){
	tp->t_state &= ~TS_BUSY;
	spltty();
	ndflush(&tp->t_outq, n);
	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);
}

zs_init(zp)
struct zs *zp;
{
    register int s;

    s = splzs();
    zscc_init(zp, &zp->tty->t_termios);
    zp->rr0 = zp->modem_state = ZREAD0(&zp->scc);
    ZBIS(&zp->scc, 1, 0x13);		/* ints on tx, rx and ext/status */
    ZBIS(&zp->scc, 9, 8);		/* enable ints */
    zp->flags |= ZS_INTEN;
    splx(s);
}

zscc_init(zp, par)
struct zs *zp;
struct termios *par;
{
    struct sccregs *scc;

    scc = &zp->scc;
    ZWRITE(scc, 2, 0);
    ZWRITE(scc, 10, 0);
    ZWRITE(scc, 11, 0x50);		/* rx & tx clock = brgen */
    ZWRITE(scc, 14, 3);			/* brgen enabled, from pclk */
    zp->imask = zscc_params(scc, par, !(zp->flags & ZS_SCSI));
    if( (zp->flags & ZS_SCSI) == 0 )
	ZBIS(scc, 5, 0x82);		/* set DTR and RTS */
    zp->flags |= ZS_INITED;
}

int
zscc_params(scc, par, use_modem_lines)
    struct sccregs *scc;
    struct termios *par;
    int use_modem_lines;
{
    unsigned divisor, speed;
    int spd, imask, ints;

    speed = par->c_ospeed;
    if( speed == 0 ){
	/* disconnect - drop DTR & RTS, disable receiver */
	if( use_modem_lines )
	    ZBIC(scc, 5, 0x82);
	ZBIC(scc, 3, 1);
	return 0xFF;
    }
    if( (par->c_cflag & CREAD) == 0 )
	ZBIC(scc, 3, 1);	/* disable receiver */
    divisor = (PCLK_FREQ/32 + (speed >> 1)) / speed - 2;
    ZWRITE(scc, 12, divisor);
    ZWRITE(scc, 13, divisor >> 8);
    switch( par->c_cflag & CSIZE ){
    case CS5:	spd = 0;	imask = 0x1F;	break;
    case CS6:	spd = 0x40;	imask = 0x3F;	break;
    case CS7:	spd = 0x20;	imask = 0x7F;	break;
    default:	spd = 0x60;	imask = 0xFF;
    }
    ZWRITE(scc, 5, (scc->s_val[5] & ~0x60) | spd);
    ZWRITE(scc, 3, (scc->s_val[3] & ~0xC0) | (spd << 1));
    spd = par->c_cflag & CSTOPB? 8: 0;
    spd |= par->c_cflag & PARENB? par->c_cflag & PARODD? 1: 3: 0;
    ZWRITE(scc, 4, 0x44 | spd);
    ZBIS(scc, 5, 8);		/* enable transmitter */
    if( (par->c_cflag & CREAD) != 0 )
	ZBIS(scc, 3, 1);	/* enable receiver */
    ints = 0;
    if( use_modem_lines ){
	if( (par->c_cflag & CLOCAL) == 0 )
	    ints |= SCC_DCD;
	if( (par->c_cflag & CCTS_OFLOW) != 0 )
	    ints |= SCC_CTS;
	ZWRITE(scc, 15, ints);
    }
    return imask;
}

zscc_mget(register struct sccregs *scc)
{
    int bits = 0, rr0;

    if( (scc->s_val[3] & SCC_RCVEN) != 0 )
	bits |= TIOCM_LE;
    if( (scc->s_val[5] & SCC_DTR) != 0 )
	bits |= TIOCM_DTR;
    if( (scc->s_val[5] & SCC_RTS) != 0 )
	bits |= TIOCM_RTS;
    rr0 = ZREAD0(scc);
    if( (rr0 & SCC_CTS) != 0 )
	bits |= TIOCM_CTS;
    if( (rr0 & SCC_DCD) != 0 )
	bits |= TIOCM_CAR;
    return bits;
}

zscc_mset(register struct sccregs *scc, int bits)
{
    if( (bits & TIOCM_LE) != 0 )
	ZBIS(scc, 3, SCC_RCVEN);
    if( (bits & TIOCM_DTR) != 0 )
	ZBIS(scc, 5, SCC_DTR);
    if( (bits & TIOCM_RTS) != 0 )
	ZBIS(scc, 5, SCC_RTS);
}

zscc_mclr(register struct sccregs *scc, int bits)
{
    if( (bits & TIOCM_LE) != 0 )
	ZBIC(scc, 3, SCC_RCVEN);
    if( (bits & TIOCM_DTR) != 0 )
	ZBIC(scc, 5, TIOCM_DTR);
    if( (bits & TIOCM_RTS) != 0 )
	ZBIC(scc, 5, SCC_RTS);
}

zs_drain(register struct zs *zp)
{
    register int s;

    zp->tty->t_state |= TS_DRAIN;
    /* wait for Tx buffer empty and All sent bits to be set */
    s = splzs();
    while( (ZREAD0(&zp->scc) & SCC_TXRDY) == 0
	  || (ZREAD(&zp->scc, 1) & 1) == 0 ){
	splx(s);
	DELAY(100);
	s = splzs();
    }
    splx(s);
}

zs_unblock(register struct tty *tp)
{
    tp->t_state &= ~TS_DRAIN;
    if( tp->t_outq.c_cc != 0 )
	zsstart(tp);
}

/*
 * Hardware interrupt from an SCC.
 */
int
zsirq(int unit)
{
    struct zssoftc *dv = (struct zssoftc *) zscd.cd_devs[unit];
    register struct zs *zp = &dv->zs[0];
    register int ipend, x;
    register volatile struct scc *scc;

    x = splzs();
    scc = zp->scc.s_adr;
    scc->cr = 3;			/* read int pending from A side */
    DELAY(5);
    ipend = scc->cr;
    if( (ipend & 0x20) != 0 )
	zs_rxint(zp);
    if( (ipend & 0x10) != 0 )
	zs_txint(zp);
    if( (ipend & 0x8) != 0 )
	zs_extint(zp);
    ++zp;				/* now look for B side ints */
    if( (ipend & 0x4) != 0 )
	zs_rxint(zp);
    if( (ipend & 0x2) != 0 )
	zs_txint(zp);
    if( (ipend & 0x1) != 0 )
	zs_extint(zp);
    splx(x);
    return ipend != 0;
}

zs_txint(register struct zs *zp)
{
    struct tty *tp = zp->tty;
    struct sccregs *scc;
    int c;
    u_char *get;

    scc = &zp->scc;
    ZWRITE0(scc, 0x28);		/* reset Tx interrupt */
    if( (zp->hflags & ZH_OBLOCK) == 0 ){
	get = zp->send_ptr;
	while( (ZREAD0(scc) & SCC_TXRDY) != 0 && zp->send_count > 0 ){
	    c = *get++;
	    ZWRITED(scc, c);
	    --zp->send_count;
	    ++zp->sent_count;
	}
	zp->send_ptr = get;
	if( zp->send_count == 0 && (zp->hflags & ZH_TXING) != 0 ){
	    zp->hflags &= ~ZH_TXING;
	    zp->hflags |= ZH_SIRQ;
	    setsoftint(sir_zs);
	}
    }
}

zs_rxint(register struct zs *zp)
{
    register int stat, c, n, extra;
    u_char *put;

    put = zp->rcv_put;
    n = zp->rcv_count;
    for(;;){
	if( (ZREAD0(&zp->scc) & SCC_RXFULL) == 0 )	/* check Rx full */
	    break;
	stat = ZREAD(&zp->scc, 1) & 0x70;
	c = ZREADD(&zp->scc) & zp->imask;
	/* stat encodes parity, overrun, framing errors */
	if( stat != 0 )
	    ZWRITE0(&zp->scc, 0x30);	/* reset error */
	if( (zp->hflags & ZH_RXOVF) != 0 ){
	    zp->hflags &= ~ZH_RXOVF;
	    stat |= 0x20;
	}
	extra = (stat != 0 || c == ERROR_DET)? 2: 0;
	if( n + extra + 1 < zp->rcv_len ){
	    if( extra != 0 ){
		*put++ = ERROR_DET;
		if( put >= zp->rcv_end )
		    put = zp->rcv_buf;
		*put++ = stat;
		if( put >= zp->rcv_end )
		    put = zp->rcv_buf;
		n += 2;
	    }
	    *put++ = c;
	    if( put >= zp->rcv_end )
		put = zp->rcv_buf;
	    ++n;
	} else
	    zp->hflags |= ZH_RXOVF;
    }
    if( n > zp->rcv_count ){
	zp->rcv_put = put;
	zp->rcv_count = n;
	zp->hflags |= ZH_SIRQ;
	setsoftint(sir_zs);
    }
}

/* Ext/status interrupt */
zs_extint(register struct zs *zp)
{
    int rr0;
    struct tty *tp = zp->tty;

    rr0 = ZREAD0(&zp->scc);
    ZWRITE0(&zp->scc, 0x10);	/* reset ext/status int */
    if( (zp->flags & ZS_SCSI) != 0 )
	zs_scsiint(zp, rr0);
    else {
	if( (tp->t_cflag & CCTS_OFLOW) != 0 && (zp->flags & ZS_SCSI) == 0 ){
	    if( (rr0 & 0x20) == 0 )
		zp->hflags |= ZH_OBLOCK;
	    else {
		zp->hflags &= ~ZH_OBLOCK;
		if( (rr0 & SCC_TXRDY) != 0 )
		    zs_txint(zp);
	    }
	}
	zp->modem_change |= rr0 ^ zp->modem_state;
	zp->modem_state = rr0;
	zp->hflags |= ZH_SIRQ;
	setsoftint(sir_zs);
    }
}

void
zs_softint()
{
    int s, n, n0, c, stat, rr0;
    struct zs *zp;
    struct tty *tp;
    u_char *get;
    int unit, side;

    s = splzs();
    for( unit = 0; unit < zscd.cd_ndevs; ++unit ){
	if( zscd.cd_devs[unit] == NULL )
	    continue;
	zp = &((struct zssoftc *) zscd.cd_devs[unit])->zs[0];
	for( side = 0; side < 2; ++side, ++zp ){
	    if( (zp->hflags & ZH_SIRQ) == 0 )
		continue;
	    zp->hflags &= ~ZH_SIRQ;
	    tp = zp->tty;

	    /* check for tx done */
	    spltty();
	    if( tp != NULL && zp->send_count == 0
	       && (tp->t_state & TS_BUSY) != 0 ){
		tp->t_state &= ~(TS_BUSY | TS_FLUSH);
		ndflush(&tp->t_outq, zp->sent_count);
		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);
		}
		if( tp->t_line != 0 )
		    (*linesw[tp->t_line].l_start)(tp);
		else
		    zsstart(tp);
	    }
	    splzs();

	    /* check for received characters */
	    get = zp->rcv_get;
	    while( zp->rcv_count > 0 ){
		c = *get++;
		if( get >= zp->rcv_end )
		    get = zp->rcv_buf;
		if( c == ERROR_DET ){
		    stat = *get++;
		    if( get >= zp->rcv_end )
			get = zp->rcv_buf;
		    c = *get++;
		    if( get >= zp->rcv_end )
			get = zp->rcv_buf;
		    zp->rcv_count -= 3;
		} else {
		    stat = 0;
		    --zp->rcv_count;
		}
		spltty();
		if( tp == NULL || (tp->t_state & TS_ISOPEN) == 0 )
		    continue;
		if( zp->nzs_open == 0 ){
		    if( stat == 0 )
			kbd_newchar(zp->gsp_unit, c);
		} else {
		    if( (stat & 0x10) != 0 )
			c |= TTY_PE;
		    if( (stat & 0x20) != 0 ){
			log(LOG_WARNING, "zs: fifo overflow\n");
			c |= TTY_FE;	/* need some error for slip stuff */
		    }
		    if( (stat & 0x40) != 0 )
			c |= TTY_FE;
		    (*linesw[tp->t_line].l_rint)(c, tp);
		}
		splzs();
	    }
	    zp->rcv_get = get;

	    /* check for modem lines changing */
	    while( zp->modem_change != 0 || zp->modem_state != zp->rr0 ){
		rr0 = zp->rr0 ^ zp->modem_change;
		zp->modem_change = rr0 ^ zp->modem_state;

		/* Check if DCD (carrier detect) has changed */
		if( tp != NULL && (rr0 & 8) != (zp->rr0 & 8) ){
		    spltty();
		    ttymodem(tp, rr0 & 8);
		    /* XXX possibly should disable line if return value is 0 */
		    splzs();
		}
		zp->rr0 = rr0;
	    }
	}
    }
    splx(s);
}

/*
 * Routines to divert an SCC channel to the input side of /dev/gsp
 * for the keyboard.
 */
int
zs_kbdopen(int unit, int gsp_unit, struct termios *tiop, struct proc *p)
{
    struct zssoftc *dv = (struct zssoftc *) zscd.cd_devs[zsunit(unit)];
    struct zs *zp = &dv->zs[zsside(unit)];
    int error;

    error = zsopen(unit, 0, 0, p);
    if( error != 0 )
	return error;
    ++zp->nkbd_open;
    --zp->nzs_open;
    zsparam(zp->tty, tiop);
    zp->gsp_unit = gsp_unit;
    return 0;
}

void
zs_kbdclose(int unit)
{
    struct zssoftc *dv = (struct zssoftc *) zscd.cd_devs[zsunit(unit)];
    struct zs *zp = &dv->zs[zsside(unit)];

    zp->nkbd_open = 0;
    if( zp->nzs_open == 0 )
	zsclose(unit, 0, 0, 0);
}

void
zs_kbdput(int unit, int c)
{
    struct zssoftc *dv = (struct zssoftc *) zscd.cd_devs[zsunit(unit)];
    struct zs *zp = &dv->zs[zsside(unit)];
    struct tty *tp = zp->tty;

    putc(c, &tp->t_outq);
    zsstart(tp);
}

/*
 * Routines for controlling the SBIC through the modem control
 * lines of an SCC.
 *
 * Interrupts from the SCSI Bus Interface Controller (sbic)
 * come in through the DCD input of the keyboard SCC.  Other
 * lines are connected as follows: CTS to the SBIC data
 * request (DRQ) output, RTS to the SCSI bus RESET line and
 * the SBIC MR (master reset) input, and DTR to the SBIC
 * DMA acknowledge input.
 */
zs_scsiint(struct zs *zp, int rr0)
{
    ZWRITE(&zp->scc, 15, 0);		/* clear ext/status IEs */
    ZBIC(&zp->scc, 1, 1);		/* disable ext/status int */
    setsoftscsi();			/* post soft int for SCSI */
}

sbic_int_enable()
{
    register struct sccregs *scc;
    register int x;

    if( zs_scsi == NULL )
	panic("SCC controlling SBIC not configured");
    scc = &zs_scsi->scc;
    x = splzs();
    ZWRITE(scc, 15, SCC_DCD|SCC_CTS);	/* enable ints from DCD & CTS */
    ZBIS(scc, 1, 1);		/* ext/status master IE */
    ZBIS(scc, 9, 8);		/* SCC master IE */
    splx(x);
}

sbic_int_disable()
{
    register struct sccregs *scc;
    register int x;

    scc = &zs_scsi->scc;
    x = splzs();
    ZWRITE(scc, 15, 0);		/* disable ext/status ints */
    ZBIC(scc, 1, 1);
    splx(x);
}

sbic_reset_scsi(int reset_on)
{
    register struct sccregs *scc;
    register int x;

    scc = &zs_scsi->scc;
    x = splzs();
    if( reset_on )
	ZBIS(scc, 5, SCC_RTS);	/* assert RTS line */
    else
	ZBIC(scc, 5, SCC_RTS);	/* negate RTS line */
    splx(x);
}

sbic_assert_dack(int dack_on)
{
    register struct sccregs *scc;
    register int x;

    scc = &zs_scsi->scc;
    x = splzs();
    if( dack_on )
	ZBIS(scc, 5, SCC_DTR);	/* assert DTR line */
    else
	ZBIC(scc, 5, SCC_DTR);	/* negate DTR line */
    splx(x);
}

/*
 * Routines for using side A of the first SCC as a console.
 */

/* probe for the SCC; should check hardware */
zscnprobe(cp)
    struct consdev *cp;
{
    int maj;
    char *prom_cons;
    extern char *prom_getvar();

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

    /* initialize required fields */
    cp->cn_dev = makedev(maj, 0);
    cp->cn_pri = CN_NORMAL;

    prom_cons = prom_getvar("console");
    if( prom_cons != NULL && strcmp(prom_cons, "0") == 0 )
	cp->cn_pri = CN_REMOTE;

    return 1;
}

/* initialize the keyboard for use as the console */
struct termios zscn_termios = {
	TTYDEF_IFLAG,
	TTYDEF_OFLAG,
	TTYDEF_CFLAG,
	TTYDEF_LFLAG,
	{0},
	TTYDEF_SPEED,
	TTYDEF_SPEED
};

struct sccregs zs_cons_sccregs;
int zs_cons_imask;

unsigned zs_cons_addrs[] = {0xE00000, 0xE10000};

zscninit()
{
    zs_cnsetup(0, &zscn_termios);
}

/* Polling routine for console input from a serial port. */
int
zscngetc(dev_t dev)
{
    register struct sccregs *scc = zs_cons_scc;
    int c, s, stat;

    s = splzs();
    for(;;){
	while( (ZREAD0(scc) & SCC_RXFULL) == 0 )	/* wait for Rx full */
	    ;
	stat = ZREAD(scc, 1) & 0x70;
	c = ZREADD(scc) & zs_cons_imask;
	/* stat encodes parity, overrun, framing errors */
	if( stat == 0 )
	    break;
	ZWRITE0(scc, 0x30);	/* reset error */
    }
    splx(s);
    return c;
}

zscnputc(dev_t dev, int c)
{
    register struct sccregs *scc = zs_cons_scc;
    int s;

    s = splzs();
    while( (ZREAD0(scc) & SCC_TXRDY) == 0 )
	;
    ZWRITED(scc, c);
    splx(s);
}

zs_cnsetup(int unit, struct termios *tiop)
{
    register volatile struct scc *scc_adr;
    register struct sccregs *scc;

    zs_cons_unit = unit;
    zs_is_console = 1;
    zs_cons_scc = scc = &zs_cons_sccregs;

    scc_adr = (volatile struct scc *) IIOV(zs_cons_addrs[zsunit(unit)]);
    scc_adr[1].cr = 0;
    scc_adr[1].cr = 9;
    scc_adr[1].cr = 0xC0;	/* hardware reset of SCC, both sides */
    if( !zsside(unit) )
	++scc_adr;

    scc->s_adr = scc_adr;
    ZWRITE(scc, 2, 0);
    ZWRITE(scc, 10, 0);
    ZWRITE(scc, 11, 0x50);	/* rx & tx clock = brgen */
    ZWRITE(scc, 14, 3);		/* brgen enabled, from pclk */
    zs_cons_imask = zscc_params(scc, tiop, unit != SCSI_UNIT);
    if( unit != SCSI_UNIT )
	ZBIS(scc, 5, 0x82);		/* set DTR and RTS */

    zs_cons_termios = *tiop;	/* save for later */
}

/*
 * Routines for using the keyboard SCC as the input side of
 * the 'gsp' console device.
 */

/* probe for the keyboard; should check hardware */
zs_kbdcnprobe(cp, unit)
    struct consdev *cp;
    int unit;
{
    return (unsigned) unit < NZSLINE;
}

#endif /* NZS */