NetBSD/sys/arch/mac68k/dev/ser.c

/*	$NetBSD: ser.c,v 1.30 1995/10/09 12:42:16 briggs Exp $	*/

/*
 * Copyright (c) 1994 Gordon W. Ross
 * Copyright (c) 1992, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This software was developed by the Computer Systems Engineering group
 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
 * contributed to Berkeley.
 *
 * All advertising materials mentioning features or use of this software
 * must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Lawrence Berkeley Laboratory.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
 *
 *	@(#)zs.c	8.1 (Berkeley) 7/19/93
 */

/*
 * Originally a custom driver.
 *	Hacked by Brad Parker, <brad@fcr.com>
 *		added CTS input flow control
 *		added DCD event detection
 *		added software fifo's
 *
 *	Mac II serial device interface
 *
 * 	Information used in this source was gleaned from low-memory
 *	 global variables in MacOS and the Advanced Micro Devices
 *	 1992 Data Book/Handbook.
 *
 *	Further hacked by Bill Studenmund <wrstuden@loki.stanford.edu>
 *		merged in much of the sun's SCC code, hence the new
 *		copyright--there's not much original ser.c code in
 *		here at all.
 *
 *	Further information from Zilog Serial Communication Controllers
 *	databook.
 */


/*
 * Zilog Z8530 (ZSCC) driver.
 *
 * Runs two tty ports (ttya and ttyb) on zs0,
 * and runs a keyboard and mouse on zs1. (at least on a sun it will!)
 *
 * This driver knows far too much about chip to usage mappings.
 */
#define NZS     1               /* XXX */

/* #include "ser.h" */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/ioctl.h>
#include <sys/tty.h>
#include <sys/proc.h>
#include <sys/conf.h>
#include <sys/file.h>
#include <sys/uio.h>
#include <sys/kernel.h>
#include <sys/syslog.h>
#include <sys/device.h>

#include <machine/cpu.h>
#include <machine/frame.h>

#include <dev/cons.h>

#undef LOCORE
#include "z8530reg.h"
#include "zsvar.h"

/* Defines for mapping zs onto the mac68k. */
#undef	ZS_DELAY()
#define ZS_DELAY()
#define	mon_printf	printf
#define	splzs		splhigh
#define isr_soft_clear(x)
#define	isr_soft_request(x) setsoftserial()
#define isr_add_autovect(x, y, z)
#define ZS_CHAN(x)	(volatile struct zschan *)(((long)addr)+x*2)
#define zsopen seropen
#define zsclose serclose
#define zsioctl serioctl
#define zsread serread
#define zswrite serwrite
#define zsparam serparam
#define zsstart serstart
#define zsstop serstop
#define zstty sertty
#define DEBUG
#undef DEBUG

#define ZSMAJOR 12              /* XXX */
/* Conveniently, this is the major number for Mac ser devices. :-) */

#define ZSHARD_PRI      4       /* Wired on the CPU board... */
#define ZSSOFT_PRI      3       /* Want tty pri (4) but this is OK. */

#define ZS_KBD          2       /* XXX */
#define ZS_MOUSE        3       /* XXX */

/*
 * Above calculation gets us to the chip clock value.
 * Needed as there are /16's scattered all over.
 */
#define	PCLK	(mac68k_machine.sccClkConst*2)

#define	ZS_HFC	(ZSRR0_DCD | ZSRR0_CTS)

/*
 * Software state per found chip.  This would be called `zs_softc',
 * but the previous driver had a rather different zs_softc....
 */
struct zsinfo {
        struct  device zi_dev;          /* base device */
        volatile struct zsdevice *zi_zs;/* chip registers */
        struct  zs_chanstate zi_cs[2];  /* channel A and B software state */
};

static struct tty *zs_tty[NZS * 2];     /* XXX should be dynamic */

/* Definition of the driver for autoconfig. */
static int      zs_match(struct device *, void *, void *);
static void     zs_attach(struct device *, struct device *, void *);

/* struct cfdriver zscd = {
        NULL, "zs", zs_match, zs_attach,
        DV_TTY, sizeof(struct zsinfo) }; */
#define	zscd	sercd
/* HACK until finished cleaning up configuration stuff */

extern int matchbyname();

struct cfdriver sercd = {
	NULL, "ser", matchbyname, zs_attach, DV_TTY, sizeof(struct zsinfo)
};

/* Interrupt handlers. */
int      zshard(int);
int      zssoft(int);
void	zsinit(void);

struct zs_chanstate *zslist;

volatile unsigned char *sccA = 0;

static void serstart __P((register struct tty *));
static int serparam __P((register struct tty *, register struct termios *));

/* Routines called from other code. */
int zsopen(dev_t, int, int, struct proc *);
int zsclose(dev_t, int, int, struct proc *);
static void     zsiopen(struct tty *);
static void     zsiclose(struct tty *);
static void     zsstart(struct tty *);
void            zsstop(struct tty *, int);
static int      zsparam(struct tty *, struct termios *);

/* Routines purely local to this driver. */
static int      zs_getspeed(volatile struct zschan *);
static void     zs_reset(volatile struct zschan *, int, int);
static void     zs_modem(struct zs_chanstate *, int);
static void     zs_loadchannelregs(volatile struct zschan *, u_char *);
static u_char zs_read(volatile struct zschan *, u_char);
static u_char zs_write(volatile struct zschan *, u_char, u_char);
static void	zs_restart(struct zs_chanstate *, volatile struct zschan *);

/* Console stuff. */
static volatile struct zschan *zs_conschan;

#ifdef KGDB
/* KGDB stuff.  Must reboot to change zs_kgdbunit. */
extern int kgdb_dev, kgdb_rate;
static int zs_kgdb_savedspeed;
static void zs_checkkgdb(int, struct zs_chanstate *, struct tty *);
#endif

static int initted = 0;
static int serdefaultrate = TTYDEF_SPEED;

static int zsinitted = 0;

extern struct tty *constty;

/*
 * Console keyboard L1-A processing is done in the hardware interrupt code,
 * so we need to duplicate some of the console keyboard decode state.  (We
 * must not use the regular state as the hardware code keeps ahead of the
 * software state: the software state tracks the most recent ring input but
 * the hardware state tracks the most recent ZSCC input.)  See also kbd.h.
 */
static struct conk_state {      /* console keyboard state */
        char    conk_id;        /* true => ID coming up (console only) */
        char    conk_l1;        /* true => L1 pressed (console only) */
} zsconk_state;

int zshardscope;
int zsshortcuts;                /* number of "shortcut" software interrupts */

int zssoftpending;              /* We have done isr_soft_request() */

static struct zsdevice *zsaddr[NZS];    /* XXX, but saves work */

/* Default OBIO addresses. */
/* static int zs_physaddr[NZS] = { OBIO_ZS, OBIO_KEYBD_MS }; not until we have OBIO */

static u_char zs_init_reg[16] = {
        0,      /* 0: CMD (reset, etc.) */
        ZSWR1_RIE | ZSWR1_TIE | ZSWR1_SIE,
        0x18 + ZSHARD_PRI,      /* IVECT */
        ZSWR3_RX_8 | ZSWR3_RX_ENABLE,
        ZSWR4_CLK_X16 | ZSWR4_ONESB | ZSWR4_EVENP,
        ZSWR5_TX_8 | ZSWR5_TX_ENABLE,
        0,      /* 6: TXSYNC/SYNCLO */
        0,      /* 7: RXSYNC/SYNCHI */
        0,      /* 8: alias for data port */
        0,      /* 9: ZSWR9_MASTER_IE (later) */
        0,      /*10: Misc. TX/RX control bits */
        ZSWR11_TXCLK_BAUD | ZSWR11_RXCLK_BAUD,
        0,      /*12: BAUDLO (later) */
        0,      /*13: BAUDHI (later) */
/*        ZSWR14_BAUD_FROM_PCLK | ZSWR14_BAUD_ENA, */
	ZSWR14_BAUD_ENA,
        ZSWR15_BREAK_IE | ZSWR15_DCD_IE | ZSWR15_CTS_IE,
};

/* Find PROM mappings (for console support). */
void zs_init()
{
        int i;

        for (i = 0; i < NZS; i++) {
              /*  zsaddr[i] = (struct zsdevice *)
                        obio_find_mapping(zs_physaddr[i], OBIO_ZS_SIZE); */
        }
}

/*
 * Match slave number to zs unit number, so that misconfiguration will
 * not set up the keyboard as ttya, etc.
 */
static int
zs_match(struct device *parent, void *vcf, void *args)
{
	struct cfdata *cf = vcf;
	struct confargs *ca = args;
	int unit, x;
	void *zsva;

	unit = cf->cf_unit;
	if (unit < 0 || unit >= NZS)
		return (0);

	zsva = zsaddr[unit];
	if (zsva == NULL)
		return (0);

/*	if (ca->ca_paddr == -1)
		ca->ca_paddr = zs_physaddr[unit];
	if (ca->ca_intpri == -1)
		ca->ca_intpri = ZSHARD_PRI;
*/
	/* This returns -1 on a fault (bus error). */
/*	x = peek_byte(zsva); */
	return (x != -1);
}

/*
 * Attach a found zs.
 *
 * USE ROM PROPERTIES port-a-ignore-cd AND port-b-ignore-cd FOR
 * SOFT CARRIER, AND keyboard PROPERTY FOR KEYBOARD/MOUSE?
 */
static void
zs_attach(struct device *parent, struct device *self, void *args)
{
	struct cfdata *cf;
	struct confargs *ca;
	register int zs, unit;
	register struct zsinfo *zi;
	register struct zs_chanstate *cs;
	register volatile struct zsdevice *addr;
	register struct tty *tp, *ctp;
	int softcar;
	static int didintr;

	cf = self->dv_cfdata;
	zs = self->dv_unit;
	ca = args;

#ifdef DEBUG
	printf(" softpri %d\n", ZSSOFT_PRI);
#endif

	if (!zsinitted)
		zsinit();

	if (zsaddr[zs] == NULL)
		panic("zs_attach: zs%d not mapped\n", zs);
	addr = zsaddr[zs];

	if (!didintr) {
		didintr = 1;
		/* On the mac, these are not used. */
		isr_add_autovect(zssoft, NULL, ZSSOFT_PRI);
		isr_add_autovect(zshard, NULL, ZSHARD_PRI);
	}

	zi = (struct zsinfo *)self;
	zi->zi_zs = addr;
	unit = zs * 2;
	cs = zi->zi_cs;
	softcar = cf->cf_flags;

	if(!zs_tty[unit])
		zs_tty[unit] = ttymalloc();
	if(!zs_tty[unit+1])
		zs_tty[unit+1] = ttymalloc();
#ifdef DEBUG
	printf("units are %x, %x\n", zs_tty[unit], zs_tty[unit+1]);
#endif

	/* link into interrupt list with order (A,B) (B=A+1) */
	cs[0].cs_next = &cs[1];
	cs[1].cs_next = zslist;
	zslist = cs;

	cs->cs_unit = unit;
	cs->cs_zc = ZS_CHAN(ZS_CHAN_A);
#ifdef DEBUG
	printf("zs channel a at %x\n",cs->cs_zc);
#endif
	cs->cs_speed = zs_getspeed(cs->cs_zc);
#ifdef	DEBUG
	mon_printf("zs%da speed %d ",  zs, cs->cs_speed);
#endif
	cs->cs_softcar = softcar & 1;
        cs->cs_rr0_mask = 0;            /* CTS is broken on the mac */
        cs->cs_SFC = 0;
        cs->cs_holdSFC = 0;
        cs->cs_tiu = 0;

	tp = zs_tty[unit];
	cs->cs_ttyp = tp;
	tp->t_dev = makedev(ZSMAJOR, unit);
	tp->t_oproc = zsstart;
	tp->t_param = zsparam;
	if (cs->cs_zc == zs_conschan) {
#ifdef DEBUG
		printf("We got a console!, unit %d\n",unit);
#endif
		/* This unit is the console. */
		cs->cs_consio = 1;
		cs->cs_brkabort = 1;
		cs->cs_softcar = 1;
		/* Call zsparam so interrupts get enabled. */
		tp->t_ispeed = tp->t_ospeed = cs->cs_speed;
		tp->t_cflag = TTYDEF_CFLAG;
		(void) zsparam(tp, &tp->t_termios);
	} else {
		/* Can not run kgdb on the console? */
#ifdef KGDB
		zs_checkkgdb(unit, cs, tp);
#endif
	}
#if 0
	/* XXX - Drop carrier here? -gwr */
	zs_modem(cs, cs->cs_softcar ? 1 : 0);
#endif

	if (unit == ZS_KBD) {
#ifdef DEBUG
		printf("We got a KBD!, unit %d\n",unit);
#endif
		/*
		 * Keyboard: tell /dev/kbd driver how to talk to us.
		 */
		tp->t_ispeed = tp->t_ospeed = cs->cs_speed;
		tp->t_cflag = CS8;
		/* zsparam called by zsiopen */
		/*kbd_serial(tp, zsiopen, zsiclose); HACK */
		cs->cs_conk = 1;		/* do L1-A processing */
	}
	unit++;
	cs++;

	cs->cs_unit = unit;
	cs->cs_zc = ZS_CHAN(ZS_CHAN_B);
#ifdef DEBUG
	printf("zs channel b at %x\n",cs->cs_zc);
#endif
	cs->cs_speed = zs_getspeed(cs->cs_zc);
#ifdef	DEBUG
	mon_printf("zs%db speed %d\n", zs, cs->cs_speed);
#endif
	cs->cs_softcar = softcar & 2;
        cs->cs_rr0_mask = 0;            /* CTS is broken on the mac */
        cs->cs_SFC = 0;
        cs->cs_holdSFC = 0;
        cs->cs_tiu = 0;

	tp = zs_tty[unit];
	cs->cs_ttyp = tp;
	tp->t_dev = makedev(ZSMAJOR, unit);
	tp->t_oproc = zsstart;
	tp->t_param = zsparam;
	if (cs->cs_zc == zs_conschan) {
#ifdef DEBUG
		printf("We got a console!, unit %d\n",unit);
#endif
		/* This unit is the console. */
		cs->cs_consio = 1;
		cs->cs_brkabort = 1;
		cs->cs_softcar = 1;
		tp->t_ispeed = tp->t_ospeed = cs->cs_speed;
		tp->t_cflag = TTYDEF_CFLAG;
		(void) zsparam(tp, &tp->t_termios);
	} else {
		/* Can not run kgdb on the console? */
#ifdef KGDB
		zs_checkkgdb(unit, cs, tp);
#endif
	}
#if 0
	/* XXX - Drop carrier here? -gwr */
	zs_modem(cs, cs->cs_softcar ? 1 : 0);
#endif

	if (unit == ZS_MOUSE) {
#ifdef DEBUG
		printf("We got a mouse!, unit %d\n",unit);
#endif
		/*
		 * Mouse: tell /dev/mouse driver how to talk to us.
		 */
		tp->t_ispeed = tp->t_ospeed = cs->cs_speed;
		tp->t_cflag = CS8;
		/* zsparam called by zsiopen */
		/* ms_serial(tp, zsiopen, zsiclose); HACK */
	}
}

/*
 * XXX - Temporary hack...
 */
struct tty *
zstty(dev)
	dev_t dev;
{
	int unit = minor(dev);

#ifdef DEBUG
	printf("Fetching tty unit %i\n", unit);
#endif

	return (zs_tty[unit]);
}

/*
 * Put a channel in a known state.  Interrupts may be left disabled
 * or enabled, as desired.  (Used only by kgdb)
 */
static void
zs_reset(zc, inten, speed)
	volatile struct zschan *zc;
	int inten, speed;
{
	int tconst;
	u_char reg[16];

	bcopy(zs_init_reg, reg, 16);
	if (inten)
		reg[9] |= ZSWR9_MASTER_IE;

	tconst = BPS_TO_TCONST(PCLK , speed);
	reg[12] = tconst;
	reg[13] = tconst >> 8;
	zs_loadchannelregs(zc, reg);
}

/*
 * Console support
 */

/*
 * Used by the kd driver to find out if it can work.
 */
int
zscnprobe_kbd()
{
	if (zsaddr[1] == NULL) {
		mon_printf("zscnprobe_kbd: zs1 not yet mapped\n");
		return CN_DEAD;
	}
	return CN_INTERNAL;
}

/*
 * This is the console probe routine for ttya and ttyb.
 */
static int
zscnprobe(struct consdev *cn, int unit)
{
	int maj;

	if (zsaddr[0] == NULL) {
		mon_printf("zscnprobe: zs0 not mapped\n");
		cn->cn_pri = CN_DEAD;
		return 0;
	}
	/* XXX - Also try to make sure it exists? */

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

	cn->cn_dev = makedev(maj, unit);

	/* Use EEPROM console setting to decide "remote" console. */
	/* Note: EE_CONS_TTYA + 1 == EE_CONS_TTYB */
/*	if (ee_console == (EE_CONS_TTYA + unit)) {
		cn->cn_pri = CN_REMOTE;
	} else { HACK */
		cn->cn_pri = CN_NORMAL;
/*	 } HACK */
	return (0);
}

/* This is the constab entry for TTYA. */
int
zscnprobe_a(struct consdev *cn)
{
	return (zscnprobe(cn, 0));
}

/* This is the constab entry for TTYB. */
int
zscnprobe_b(struct consdev *cn)
{
	return (zscnprobe(cn, 1));
}

/* Called by kdcninit() or below. */
void
zs_set_conschan(unit, ab)
	int unit, ab;
{
	volatile struct zsdevice *addr;

	addr = zsaddr[unit];
	zs_conschan = ((ab == 0) ? (ZS_CHAN(ZS_CHAN_A)):(ZS_CHAN(ZS_CHAN_B)));
}

/* Attach as console.  Also set zs_conschan */
int
zscninit(struct consdev *cn)
{
	int ab = minor(cn->cn_dev) & 1;
	zs_set_conschan(0, ab);
	mon_printf("console on zs0 (tty%c)\n", 'a' + ab);
}


/*
 * Polled console input putchar.
 */
int
zscngetc(dev)
	dev_t dev;
{
	register volatile struct zschan *zc = zs_conschan;
	register int s, c, rr0;

	if (zc == NULL)
		return (0);

	s = splhigh();

	/* Wait for a character to arrive. */
	do {
		rr0 = zc->zc_csr;
		ZS_DELAY();
	} while ((rr0 & ZSRR0_RX_READY) == 0);

	c = zc->zc_data;
	ZS_DELAY();

	splx(s);

	/*
	 * This is used by the kd driver to read scan codes,
	 * so don't translate '\r' ==> '\n' here...
	 */
	return (c);
}

/*
 * Polled console output putchar.
 */
int
zscnputc(dev, c)
	dev_t dev;
	int c;
{
	register volatile struct zschan *zc = zs_conschan;
	register int s, rr0;

	if (zc == NULL) {
		s = splhigh();
		/* mon_putchar(c); */
		splx(s);
		return (0);
	}
	s = splhigh();

	/* Wait for transmitter to become ready. */
	do {
		rr0 = zc->zc_csr;
		ZS_DELAY();
	} while ((rr0 & ZSRR0_TX_READY) == 0);

	zc->zc_data = c;
	ZS_DELAY();
	splx(s);
}

#ifdef KGDB
/*
 * The kgdb zs port, if any, was altered at boot time (see zs_kgdb_init).
 * Pick up the current speed and character size and restore the original
 * speed.
 */
static void
zs_checkkgdb(int unit, struct zs_chanstate *cs, struct tty *tp)
{

	if (kgdb_dev == makedev(ZSMAJOR, unit)) {
		tp->t_ispeed = tp->t_ospeed = kgdb_rate;
		tp->t_cflag = CS8;
		cs->cs_kgdb = 1;
		cs->cs_speed = zs_kgdb_savedspeed;
		(void) zsparam(tp, &tp->t_termios);
	}
}
#endif

/*
 * Compute the current baud rate given a ZSCC channel.
 */
static int
zs_getspeed(zc)
	register volatile struct zschan *zc;
{
	register int tconst;

	tconst = ZS_READ(zc, 12);
	tconst |= ZS_READ(zc, 13) << 8;
#ifdef DEBUG
	printf("Time const is %x \n",tconst);
#endif
	return (TCONST_TO_BPS(PCLK , tconst));
}


/*
 * Do an internal open.
 */
static void
zsiopen(tp)
	struct tty *tp;
{

	(void) zsparam(tp, &tp->t_termios);
	ttsetwater(tp);
	tp->t_state = TS_ISOPEN | TS_CARR_ON;
}

/*
 * Do an internal close.  Eventually we should shut off the chip when both
 * ports on it are closed.
 */
static void
zsiclose(tp)
	struct tty *tp;
{
#ifdef DEBUG
	printf("zs internal close.\n");
#endif

	ttylclose(tp, 0);	/* ??? */
	ttyclose(tp);		/* ??? */
	tp->t_state = 0;
}


/*
 * Open a zs serial port.  This interface may not be used to open
 * the keyboard and mouse ports. (XXX)
 */
int
zsopen(dev, flags, mode, p)
	dev_t dev;
	int flags;
	int mode;
	struct proc *p;
{
	register struct tty *tp;
	register struct zs_chanstate *cs;
	struct zsinfo *zi;
	int unit = minor(dev), zs = unit >> 1, error, s;

#ifdef	DEBUG
	mon_printf("zs_open to channel at %x\n",cs->cs_zc);
#endif
	if (zs >= zscd.cd_ndevs || (zi = zscd.cd_devs[zs]) == NULL ||
	    unit == ZS_KBD || unit == ZS_MOUSE)
		return (ENXIO);
	cs = &zi->zi_cs[unit & 1];
	tp = cs->cs_ttyp;
	s = spltty();
	if ((tp->t_state & TS_ISOPEN) == 0) {
		ttychars(tp);
		if (tp->t_ispeed == 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 = cs->cs_speed;
		}
		(void) zsparam(tp, &tp->t_termios);
		ttsetwater(tp);
	} else if (tp->t_state & TS_XCLUDE && p->p_ucred->cr_uid != 0) {
		splx(s);
		return (EBUSY);
	}
	error = 0;
#ifdef	DEBUG
	mon_printf("wait for carrier...\n");
#endif
	for (;;) {
		register int rr0;

		/* loop, turning on the device, until carrier present */
		zs_modem(cs, 1);
		/* May never get status intr if carrier already on. -gwr */
		rr0 = cs->cs_zc->zc_csr;
		ZS_DELAY();
		if (rr0 & ZSRR0_DCD)
			tp->t_state |= TS_CARR_ON;
		if (cs->cs_softcar)
			tp->t_state |= TS_CARR_ON;
		if (flags & O_NONBLOCK || tp->t_cflag & CLOCAL ||
		    tp->t_state & TS_CARR_ON)
			break;
		tp->t_state |= TS_WOPEN;
		if (error = ttysleep(tp, (caddr_t)&tp->t_rawq, TTIPRI | PCATCH,
		    ttopen, 0)) {
			if (!(tp->t_state & TS_ISOPEN)) {
				zs_modem(cs, 0);
				tp->t_state &= ~TS_WOPEN;
				ttwakeup(tp);
			}
			splx(s);
			return error;
		}
	}
#ifdef	DEBUG
	mon_printf("...carrier %s\n",
			   (tp->t_state & TS_CARR_ON) ? "on" : "off");
#endif
	splx(s);
	if (error == 0)
		error = linesw[tp->t_line].l_open(dev, tp);
	if (error)
		zs_modem(cs, 0);
	return (error);
}

/*
 * Close a zs serial port.
 */
int
zsclose(dev, flags, mode, p)
	dev_t dev;
	int flags;
	int mode;
	struct proc *p;
{
	register struct zs_chanstate *cs;
	register struct tty *tp;
	struct zsinfo *zi;
	int unit = minor(dev), s;

#ifdef	DEBUG
	mon_printf("zs_close\n");
#endif
	zi = zscd.cd_devs[unit >> 1];
	cs = &zi->zi_cs[unit & 1];
	tp = cs->cs_ttyp;
	linesw[tp->t_line].l_close(tp, flags);
/*	printf("My zsclose tty is %x, ",tp);
	printf("Stored values are: iflag %x, oflag %x, cflag %x, ospeed %x\n",tp->t_iflag, tp->t_oflag,\
		tp->t_cflag, tp->t_ospeed); */
	if (tp->t_cflag & HUPCL || tp->t_state & TS_WOPEN ||
	    (tp->t_state & TS_ISOPEN) == 0) {
		zs_modem(cs, 0);
		/* hold low for 1 second */
		(void) tsleep((caddr_t)cs, TTIPRI, ttclos, hz);
	}
	if (cs->cs_creg[5] & ZSWR5_BREAK)
	{
		s = splzs();
		cs->cs_preg[5] &= ~ZSWR5_BREAK;
		cs->cs_creg[5] &= ~ZSWR5_BREAK;
		ZS_WRITE(cs->cs_zc, 5, cs->cs_creg[5]);
		splx(s);
	}
	ttyclose(tp);
#ifdef KGDB
	/* Reset the speed if we're doing kgdb on this port */
	if (cs->cs_kgdb) {
		tp->t_ispeed = tp->t_ospeed = kgdb_rate;
		(void) zsparam(tp, &tp->t_termios);
	}
#endif
	return (0);
}

/*
 * Read/write zs serial port.
 */
int
zsread(dev, uio, flags)
	dev_t dev;
	struct uio *uio;
	int flags;
{
	register struct tty *tp = zs_tty[minor(dev)];

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

int
zswrite(dev, uio, flags)
	dev_t dev;
	struct uio *uio;
	int flags;
{
	register struct tty *tp = zs_tty[minor(dev)];
#ifdef DEBUG
	printf("Writing\n");
#endif

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

/*
 * ZS hardware interrupt.  Scan all ZS channels.  NB: we know here that
 * channels are kept in (A,B) pairs.
 *
 * Do just a little, then get out; set a software interrupt if more
 * work is needed.
 *
 * We deliberately ignore the vectoring Zilog gives us, and match up
 * only the number of `reset interrupt under service' operations, not
 * the order.
 */
/* ARGSUSED */
int
zshard(intrarg)
	int intrarg;
{
	register struct zs_chanstate *a;
#define	b (a + 1)
	register volatile struct zschan *zc;
	register int rr3, intflags = 0, i;
	register long v;
	static long zsrint(struct zs_chanstate *, volatile struct zschan *);
	static long zsxint(struct zs_chanstate *, volatile struct zschan *);
	static long zssint(struct zs_chanstate *, volatile struct zschan *);

	if (!sccA) return;

	for (a = zslist; a != NULL; a = b->cs_next) {
		rr3 = ZS_READ(a->cs_zc, 3);

		/* XXX - This should loop to empty the on-chip fifo. */
		if (rr3 & (ZSRR3_IP_A_RX|ZSRR3_IP_A_TX|ZSRR3_IP_A_STAT)) {
			intflags |= 2;
			zc = a->cs_zc;
#ifdef DEBUG
			printf("z %x ",ZS_READ(a->cs_zc,0));
#endif
			i = a->cs_rbput;
			if (rr3 & ZSRR3_IP_A_RX && (v = zsrint(a, zc)) != 0) {
				a->cs_rbuf[i++ & ZLRB_RING_MASK] = v;
				intflags |= 1;
				while (ZS_READ(a->cs_zc, 0) & ZSRR0_RX_READY)
					if ((v = zsrint(a, zc)) != 0)
						a->cs_rbuf[i++ & ZLRB_RING_MASK] = v;
			}
			if (rr3 & ZSRR3_IP_A_TX && (v = zsxint(a, zc)) != 0) {
				a->cs_rbuf[i++ & ZLRB_RING_MASK] = v;
				intflags |= 1;
			}
			if (rr3 & ZSRR3_IP_A_STAT && (v = zssint(a, zc)) != 0) {
				a->cs_rbuf[i++ & ZLRB_RING_MASK] = v;
				intflags |= 1;
			}
			a->cs_rbput = i;
		}

		/* XXX - This should loop to empty the on-chip fifo. */
		if (rr3 & (ZSRR3_IP_B_RX|ZSRR3_IP_B_TX|ZSRR3_IP_B_STAT)) {
			intflags |= 2;
			zc = b->cs_zc;
#ifdef DEBUG
			printf("zb %x ",ZS_READ(b->cs_zc,0));
#endif
			i = b->cs_rbput;
			if (rr3 & ZSRR3_IP_B_RX && (v = zsrint(b, zc)) != 0) {
				b->cs_rbuf[i++ & ZLRB_RING_MASK] = v;
				intflags |= 1;
				while (ZS_READ(b->cs_zc, 0) & ZSRR0_RX_READY)
					if ((v = zsrint(b, zc)) != 0)
						b->cs_rbuf[i++ & ZLRB_RING_MASK] = v;
			}
			if (rr3 & ZSRR3_IP_B_TX && (v = zsxint(b, zc)) != 0) {
				b->cs_rbuf[i++ & ZLRB_RING_MASK] = v;
				intflags |= 1;
			}
			if (rr3 & ZSRR3_IP_B_STAT && (v = zssint(b, zc)) != 0) {
				b->cs_rbuf[i++ & ZLRB_RING_MASK] = v;
				intflags |= 1;
			}
			b->cs_rbput = i;
		}
	}
#undef b
	if (intflags & 1) {
		if (zssoftpending == 0) {
			/* We are at splzs here, so no need to lock. */
			zssoftpending = ZSSOFT_PRI;
			isr_soft_request(ZSSOFT_PRI);
		}
	}
	return (intflags & 2);
}

static long
zsrint(cs, zc)
	register struct zs_chanstate *cs;
	register volatile struct zschan *zc;
{
	register long c;

	c = zc->zc_data;
	ZS_DELAY();
#ifdef DEBUG
	printf("r%x ",c);
#endif

	if (cs->cs_conk) {
		register struct conk_state *conk = &zsconk_state;

#define	KBD_RESET 0
#define	KBD_L1    4
#define	KBD_UP    2
#define	KBD_A	  8
		/*
		 * Check here for console abort function, so that we
		 * can abort even when interrupts are locking up the
		 * machine.
		 */
		if (c == KBD_RESET) {
			conk->conk_id = 1;	/* ignore next byte */
			conk->conk_l1 = 0;
		} else if (conk->conk_id)
			conk->conk_id = 0;	/* stop ignoring bytes */
		else if (c == KBD_L1)
			conk->conk_l1 = 1;	/* L1 went down */
		else if (c == (KBD_L1|KBD_UP))
			conk->conk_l1 = 0;	/* L1 went up */
		else if (c == KBD_A && conk->conk_l1) {
			zsabort();
			/* Debugger done.  Send L1-up in case X is running. */
			conk->conk_l1 = 0;
			c = (KBD_L1|KBD_UP);
		}
	}
#ifdef KGDB
	/*if (c == FRAME_START && cs->cs_kgdb && 
	    (cs->cs_ttyp->t_state & TS_ISOPEN) == 0) {
		zskgdb(cs->cs_unit);
		c = 0;
		goto clearit;
	} */
#endif
	/* compose receive character and status */
	c <<= 8;
	c |= ZS_READ(zc, 1);
	c = ZRING_MAKE(ZRING_RINT, c);

clearit:
	/* clear receive error & interrupt condition */
	zc->zc_csr = ZSWR0_RESET_ERRORS;
	ZS_DELAY();
	zc->zc_csr = ZSWR0_CLR_INTR;
	ZS_DELAY();
	return (c);
}

static long
zsxint(cs, zc)
	register struct zs_chanstate *cs;
	register volatile struct zschan *zc;
{
	register int i = cs->cs_tbc;

	if (i == 0) {
		zc->zc_csr = ZSWR0_RESET_TXINT;
		ZS_DELAY();
		zc->zc_csr = ZSWR0_CLR_INTR;
		ZS_DELAY();
		cs->cs_tiu = 0;
#ifdef DEBUG
		printf("Td ");
#endif
		return (ZRING_MAKE(ZRING_XINT, 0));
	}
#ifdef DEBUGTX
	printf(" t%x ",(u_char)*cs->cs_tba);
#endif
	if (cs->cs_holdSFC) {
		cs->cs_tiu = 0;		/* transmitter is no longer in use */
		zc->zc_csr = ZSWR0_RESET_TXINT;
		ZS_DELAY();
		zc->zc_csr = ZSWR0_CLR_INTR;
		ZS_DELAY();
		return (0);
	}
	cs->cs_tbc = i - 1;
	zc->zc_data = *cs->cs_tba++;
	ZS_DELAY();
	zc->zc_csr = ZSWR0_CLR_INTR;
	ZS_DELAY();
	return (0);
}

static long
zssint(cs, zc)
	register struct zs_chanstate *cs;
	register volatile struct zschan *zc;
{
	register int rr0;

	rr0 = zc->zc_csr;
	ZS_DELAY();
	rr0 = zc->zc_csr;
	ZS_DELAY();
	zc->zc_csr = ZSWR0_RESET_STATUS;
	ZS_DELAY();
	zc->zc_csr = ZSWR0_CLR_INTR;
	ZS_DELAY();
	/*
	 * The chip's hardware flow control is, as noted in zsreg.h,
	 * busted---if the DCD line goes low the chip shuts off the
	 * receiver (!).  If we want hardware CTS flow control but do
	 * not have it, and carrier is now on, turn HFC on; if we have
	 * HFC now but carrier has gone low, turn it off.
	 */
	/* if (rr0 & ZSRR0_DCD) {
		if (cs->cs_ttyp->t_cflag & CCTS_OFLOW &&
		    (cs->cs_creg[3] & ZSWR3_HFC) == 0) {
			cs->cs_creg[3] |= ZSWR3_HFC;
			ZS_WRITE(zc, 3, cs->cs_creg[3]);
		}
	} else {
		if (cs->cs_creg[3] & ZSWR3_HFC) {
			cs->cs_creg[3] &= ~ZSWR3_HFC;
			ZS_WRITE(zc, 3, cs->cs_creg[3]);
		}
	} */
	if (cs->cs_SFC) {
		register u_char nhold = \
				(((rr0 ^ cs->cs_rr0_mask) & ZS_HFC)==ZS_HFC) ? 1 : 0;
		if (nhold != cs->cs_holdSFC) { /* our holding state has changed */
			cs->cs_holdSFC = nhold;
			if ((nhold == 0) && (cs->cs_tbc != 0)) {
				/* a character is waiting; send it */
				zs_restart(cs, zc);
			}
#ifdef DEBUG
			printf(" ntd CTS change, hl %d ",nhold);
#endif 
		}
	}
	if ((rr0 & ZSRR0_BREAK) && cs->cs_brkabort) {
		/* Wait for end of break to avoid PROM abort. */
		do {
			rr0 = zc->zc_csr;
			ZS_DELAY();
		} while (rr0 & ZSRR0_BREAK);
		zsabort();
		return (0);
	}
#ifdef DEBUG
	printf(" s%x ",rr0);
#endif
	return (ZRING_MAKE(ZRING_SINT, rr0));
}

static void
zs_restart(cs, zc)
        register struct zs_chanstate *cs;
        register volatile struct zschan *zc;
{
	cs->cs_tbc -= 1;
	zc->zc_data = *cs->cs_tba++;
	ZS_DELAY();
	cs->cs_tiu = 1;
#ifdef DEBUG
	printf(" restart tx ");
#endif
}

zsabort()
{
#ifdef DDB
	Debugger();
#endif
}

#ifdef KGDB
/*
 * KGDB framing character received: enter kernel debugger.  This probably
 * should time out after a few seconds to avoid hanging on spurious input.
 */
zskgdb(unit)
	int unit;
{

	printf("zs%d%c: kgdb interrupt\n", unit >> 1, (unit & 1) + 'a');
	kgdb_connect(1);
}
#endif

/*
 * Print out a ring or fifo overrun error message.
 */
static void
zsoverrun(unit, ptime, what)
	int unit;
	long *ptime;
	char *what;
{

	if (*ptime != time.tv_sec) {
		*ptime = time.tv_sec;
		log(LOG_WARNING, "zs%d%c: %s overrun\n", unit >> 1,
		    (unit & 1) + 'a', what);
	}
}

/*
 * ZS software interrupt.  Scan all channels for deferred interrupts.
 */
int
zssoft(arg)
	int arg;
{
	register struct zs_chanstate *cs;
	register volatile struct zschan *zc;
	register struct linesw *line;
	register struct tty *tp;
	register int get, n, c, cc, unit, s;

	/* This is not the only ISR on this IPL. */
	if (zssoftpending == 0)
		return (0);
#ifdef DEBUG
	printf("zs");
#endif

	/*
	 * The soft intr. bit will be set by zshard only if
	 * the variable zssoftpending is zero.  The order of
	 * these next two statements prevents our clearing
	 * the soft intr bit just after zshard has set it.
	 */
	isr_soft_clear(ZSSOFT_PRI);
	zssoftpending = 0;	/* Now zshard may set it again. */

	for (cs = zslist; cs != NULL; cs = cs->cs_next) {
		get = cs->cs_rbget;
again:
		n = cs->cs_rbput;	/* atomic */
		if (get == n)		/* nothing more on this line */
			continue;
		unit = cs->cs_unit;	/* set up to handle interrupts */
		zc = cs->cs_zc;
		tp = cs->cs_ttyp;
		line = &linesw[tp->t_line];
		/*
		 * Compute the number of interrupts in the receive ring.
		 * If the count is overlarge, we lost some events, and
		 * must advance to the first valid one.  It may get
		 * overwritten if more data are arriving, but this is
		 * too expensive to check and gains nothing (we already
		 * lost out; all we can do at this point is trade one
		 * kind of loss for another).
		 */
		n -= get;
		if (n > ZLRB_RING_SIZE) {
			zsoverrun(unit, &cs->cs_rotime, "ring");
			get += n - ZLRB_RING_SIZE;
			n = ZLRB_RING_SIZE;
		}
		while (--n >= 0) {
			/* race to keep ahead of incoming interrupts */
			c = cs->cs_rbuf[get++ & ZLRB_RING_MASK];
			switch (ZRING_TYPE(c)) {

			case ZRING_RINT:
				c = ZRING_VALUE(c);
				if (c & ZSRR1_DO)
					zsoverrun(unit, &cs->cs_fotime, "fifo");
				cc = c >> 8;
				if (c & ZSRR1_FE)
					cc |= TTY_FE;
				if (c & ZSRR1_PE)
					cc |= TTY_PE;
				/*
				 * this should be done through
				 * bstreams	XXX gag choke
				 */
				/* if (unit == ZS_KBD)
					kbd_rint(cc);
				else if (unit == ZS_MOUSE)
					ms_rint(cc);
				else */
					if ((tp->t_state & TS_ISOPEN) != 0)
						line->l_rint(cc, tp);
				break;

			case ZRING_XINT:
				/*
				 * Transmit done: change registers and resume,
				 * or clear BUSY.
				 */
				if (cs->cs_heldchange) {
					s = splzs();
					c = zc->zc_csr;
					ZS_DELAY();
					if ((c & ZSRR0_DCD) == 0)
						cs->cs_preg[3] &= ~ZSWR3_HFC;
					bcopy((caddr_t)cs->cs_preg,
					    (caddr_t)cs->cs_creg, 16);
					zs_loadchannelregs(zc, cs->cs_creg);
					splx(s);
					cs->cs_heldchange = 0;
					if (cs->cs_heldtbc &&
					    (tp->t_state & TS_TTSTOP) == 0) {
						cs->cs_tbc = cs->cs_heldtbc - 1;
						zc->zc_data = *cs->cs_tba++;
						ZS_DELAY();
						goto again;
					}
				}
				tp->t_state &= ~TS_BUSY;
				if (tp->t_state & TS_FLUSH)
					tp->t_state &= ~TS_FLUSH;
				else
					ndflush(&tp->t_outq, cs->cs_tba -
						(caddr_t) tp->t_outq.c_cf);
				if ((tp->t_state & TS_ISOPEN) != 0)
					line->l_start(tp);
				break;

			case ZRING_SINT:
				/*
				 * Status line change.  HFC bit is run in
				 * hardware interrupt, to avoid locking
				 * at splzs here.
				 */
				c = ZRING_VALUE(c);
				if ((c ^ cs->cs_rr0) & ZSRR0_DCD) {
					cc = (c & ZSRR0_DCD) != 0;
					if (line->l_modem(tp, cc) == 0)
						zs_modem(cs, cc);
				}
				cs->cs_rr0 = c;
				break;

			default:
				log(LOG_ERR, "zs%d%c: bad ZRING_TYPE (%x)\n",
				    unit >> 1, (unit & 1) + 'a', c);
				break;
			}
		}
		cs->cs_rbget = get;
		goto again;
	}
	return (1);
}

int
zsioctl(dev, cmd, data, flag, p)
	dev_t dev;
	u_long cmd;
	caddr_t data;
	int flag;
	struct proc *p;
{
	int unit = minor(dev);
	struct zsinfo *zi = zscd.cd_devs[unit >> 1];
	register struct zs_chanstate *cs = &zi->zi_cs[unit & 1];
	register struct tty *tp = cs->cs_ttyp;
	register int error, s;

#ifdef DEBUG
	printf("My tty in zsioctl is %x, my command is %x, and my zc is %x\n",tp,cmd,cs->cs_zc);
#endif

	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);

	switch (cmd) {

	case TIOCSBRK:
		s = splzs();
		cs->cs_preg[5] |= ZSWR5_BREAK;
		cs->cs_creg[5] |= ZSWR5_BREAK;
		ZS_WRITE(cs->cs_zc, 5, cs->cs_creg[5]);
		splx(s);
		break;

	case TIOCCBRK:
		s = splzs();
		cs->cs_preg[5] &= ~ZSWR5_BREAK;
		cs->cs_creg[5] &= ~ZSWR5_BREAK;
		ZS_WRITE(cs->cs_zc, 5, cs->cs_creg[5]);
		splx(s);
		break;

	case TIOCGFLAGS: {
		int bits = 0;

		if (cs->cs_softcar)
			bits |= TIOCFLAG_SOFTCAR;
		if (cs->cs_creg[15] & ZSWR15_DCD_IE)
			bits |= TIOCFLAG_CLOCAL;
		if (cs->cs_creg[3] & ZSWR3_HFC)
			bits |= TIOCFLAG_CRTSCTS;
		*(int *)data = bits;
		break;
	}

	case TIOCSFLAGS: {
		int userbits, driverbits = 0;

		error = suser(p->p_ucred, &p->p_acflag);
		if (error != 0)
			return (EPERM);

		userbits = *(int *)data;

		/*
		 * can have `local' or `softcar', and `rtscts' or `mdmbuf'
		 * defaulting to software flow control.
		 */
		if (userbits & TIOCFLAG_SOFTCAR && userbits & TIOCFLAG_CLOCAL)
			return(EINVAL);
		if (userbits & TIOCFLAG_MDMBUF)	/* don't support this (yet?) */
			return(ENXIO);

		s = splzs();
		if ((userbits & TIOCFLAG_SOFTCAR) ||
			(cs->cs_zc == zs_conschan))
		{
			cs->cs_softcar = 1;	/* turn on softcar */
			cs->cs_preg[15] &= ~ZSWR15_DCD_IE; /* turn off dcd */
			cs->cs_creg[15] &= ~ZSWR15_DCD_IE;
			ZS_WRITE(cs->cs_zc, 15, cs->cs_creg[15]);
		} else if (userbits & TIOCFLAG_CLOCAL) {
			cs->cs_softcar = 0; 	/* turn off softcar */
			cs->cs_preg[15] |= ZSWR15_DCD_IE; /* turn on dcd */
			cs->cs_creg[15] |= ZSWR15_DCD_IE;
			ZS_WRITE(cs->cs_zc, 15, cs->cs_creg[15]);
			tp->t_termios.c_cflag |= CLOCAL;
		}
		if (userbits & TIOCFLAG_CRTSCTS) {
			cs->cs_preg[15] |= ZSWR15_CTS_IE;
			cs->cs_creg[15] |= ZSWR15_CTS_IE;
			ZS_WRITE(cs->cs_zc, 15, cs->cs_creg[15]);
			cs->cs_preg[3] |= ZSWR3_HFC;
			cs->cs_creg[3] |= ZSWR3_HFC;
			ZS_WRITE(cs->cs_zc, 3, cs->cs_creg[3]);
			tp->t_termios.c_cflag |= CRTSCTS;
		} else {
			/* no mdmbuf, so we must want software flow control */
			cs->cs_preg[15] &= ~ZSWR15_CTS_IE;
			cs->cs_creg[15] &= ~ZSWR15_CTS_IE;
			ZS_WRITE(cs->cs_zc, 15, cs->cs_creg[15]);
			cs->cs_preg[3] &= ~ZSWR3_HFC;
			cs->cs_creg[3] &= ~ZSWR3_HFC;
			ZS_WRITE(cs->cs_zc, 3, cs->cs_creg[3]);
			tp->t_termios.c_cflag &= ~CRTSCTS;
		}
		splx(s);
		break;
	}

	case TIOCSDTR:
		zs_modem(cs, 1);
		break;
	case TIOCCDTR:
		zs_modem(cs, 0);
		break;

	case TIOCMSET:
	case TIOCMBIS:
	case TIOCMBIC:
	case TIOCMGET:
	default:
		return (ENOTTY);
	}
	return (0);
}

/*
 * Start or restart transmission.
 */
static void
zsstart(tp)
	register struct tty *tp;
{
	register struct zs_chanstate *cs;
	register int s, nch;
	int unit = minor(tp->t_dev);
	struct zsinfo *zi = zscd.cd_devs[unit >> 1];

	cs = &zi->zi_cs[unit & 1];
	s = spltty();

	/*
	 * If currently active or delaying, no need to do anything.
	 */
	if (tp->t_state & (TS_TIMEOUT | TS_BUSY | TS_TTSTOP))
		goto out;

	/*
	 * If there are sleepers, and output has drained below low
	 * water mark, awaken.
	 */
	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);
	}
#ifdef DEBUG
	printf("stat %x ",ZS_READ(cs->cs_zc,0));
#endif

	nch = ndqb(&tp->t_outq, 0);	/* XXX */
	if (nch) {
		register char *p = tp->t_outq.c_cf;

		/* mark busy, enable tx done interrupts, & send first byte */
		tp->t_state |= TS_BUSY;
#ifdef DEBUG
		printf(" out w/ %x ",(u_char)*p);
#endif
		(void) splzs();
		cs->cs_preg[1] |= ZSWR1_TIE;
		cs->cs_creg[1] |= ZSWR1_TIE;
		ZS_WRITE(cs->cs_zc, 1, cs->cs_creg[1]);
		cs->cs_tba = p;
		cs->cs_tbc = nch;
		if ((cs->cs_SFC == 0) || (cs->cs_holdSFC == 0))
			zs_restart(cs, cs->cs_zc);
	} else {
		/*
		 * Nothing to send, turn off transmit done interrupts.
		 * This is useful if something is doing polled output.
		 */
#ifdef DEBUG
		printf(" off ");
#endif
		(void) splzs();
		cs->cs_preg[1] &= ~ZSWR1_TIE;
		cs->cs_creg[1] &= ~ZSWR1_TIE;
		ZS_WRITE(cs->cs_zc, 1, cs->cs_creg[1]);
	}
out:
	splx(s);
}

/*
 * Stop output, e.g., for ^S or output flush.
 */
void
zsstop(tp, flag)
	register struct tty *tp;
	int flag;
{
	register struct zs_chanstate *cs;
	register int s, unit = minor(tp->t_dev);
	struct zsinfo *zi = zscd.cd_devs[unit >> 1];

	cs = &zi->zi_cs[unit & 1];
	s = splzs();
	if (tp->t_state & TS_BUSY) {
		/*
		 * Device is transmitting; must stop it.
		 */
		cs->cs_tbc = 0;
		if ((tp->t_state & TS_TTSTOP) == 0)
			tp->t_state |= TS_FLUSH;
	}
	splx(s);
}

/*
 * Set ZS tty parameters from termios.
 */
static int
zsparam(tp, t)
	register struct tty *tp;
	register struct termios *t;
{
	int unit = minor(tp->t_dev);
	struct zsinfo *zi = zscd.cd_devs[unit >> 1];
	register struct zs_chanstate *cs = &zi->zi_cs[unit & 1];
	register int tmp, tmp5, cflag, s, tmpx;

	/*
	 * Because PCLK is only run at 4.9 MHz, the fastest we
	 * can go is 51200 baud (this corresponds to TC=1).
	 * This is somewhat unfortunate as there is no real
	 * reason we should not be able to handle higher rates.
	 */
	tmp = t->c_ospeed;
	if (tmp < 0 || (t->c_ispeed && t->c_ispeed != tmp))
		return (EINVAL);
	if (tmp == 0) {
		/* stty 0 => drop DTR and RTS */
		zs_modem(cs, 0);
		return (0);
	}
	tmp = BPS_TO_TCONST(PCLK , tmp);
	if (tmp < 0)
		return (EINVAL);

	cflag = t->c_cflag;
	tp->t_ispeed = tp->t_ospeed = TCONST_TO_BPS(PCLK , tmp);
	tp->t_cflag = cflag;

	/*
	 * Block interrupts so that state will not
	 * be altered until we are done setting it up.
	 */
	s = splzs();
	bcopy(zs_init_reg, cs->cs_preg, 16);
	cs->cs_preg[12] = tmp & 255;
	cs->cs_preg[13] = tmp >> 8;
	cs->cs_preg[9] |= ZSWR9_MASTER_IE;
	switch (cflag & CSIZE) {
	case CS5:
		tmp = ZSWR3_RX_5;
		tmp5 = ZSWR5_TX_5;
		break;
	case CS6:
		tmp = ZSWR3_RX_6;
		tmp5 = ZSWR5_TX_6;
		break;
	case CS7:
		tmp = ZSWR3_RX_7;
		tmp5 = ZSWR5_TX_7;
		break;
	case CS8:
	default:
		tmp = ZSWR3_RX_8;
		tmp5 = ZSWR5_TX_8;
		break;
	}

	/*
	 * Output hardware flow control on the chip is horrendous: if
	 * carrier detect drops, the receiver is disabled.  Hence we
	 * can only do this when the carrier is on.
	 */
	tmp |= ZSWR3_RX_ENABLE;
	if (cflag & CCTS_OFLOW) {
	    if (1) {
		cs->cs_SFC = 1;
		cs->cs_holdSFC = (((cs->cs_zc->zc_csr ^ cs->cs_rr0_mask) & ZS_HFC)==ZS_HFC) ? 1 : 0;
	    } else {
		if (cs->cs_zc->zc_csr & ZSRR0_DCD)
			tmp |= ZSWR3_HFC;
		ZS_DELAY();
	    }
	} else {
		tmpx = (cs->cs_SFC ? cs->cs_holdSFC : 0); /* (cs_SFC !=0) && (cs_holdSFC !=0) */
		cs->cs_SFC = 0;
		cs->cs_holdSFC = 0;
		if (tmpx)
			zs_restart(cs, cs->cs_zc); /* we were waiting because of SFC, but now we don't */
	}

	cs->cs_preg[3] = tmp;
	cs->cs_preg[5] = tmp5 | ZSWR5_TX_ENABLE | ZSWR5_DTR | ZSWR5_RTS;;

	tmp = ZSWR4_CLK_X16 | (cflag & CSTOPB ? ZSWR4_TWOSB : ZSWR4_ONESB);
	if ((cflag & PARODD) == 0)
		tmp |= ZSWR4_EVENP;
	if (cflag & PARENB)
		tmp |= ZSWR4_PARENB;
	cs->cs_preg[4] = tmp;

	/*
	 * If nothing is being transmitted, set up new current values,
	 * else mark them as pending.
	 */
	if (cs->cs_heldchange == 0) {
		if (cs->cs_ttyp->t_state & TS_BUSY) {
			cs->cs_heldtbc = cs->cs_tbc;
			cs->cs_tbc = 0;
			cs->cs_heldchange = 1;
		} else {
			bcopy((caddr_t)cs->cs_preg, (caddr_t)cs->cs_creg, 16);
			zs_loadchannelregs(cs->cs_zc, cs->cs_creg);
		}
	}
	splx(s);
#ifdef DEBUG
	printf("My zsparam tty is %x, my termios is %x, iflag %x, oflag %x, cflag %x\n",tp,t, \
		t->c_iflag, t->c_oflag, t->c_cflag);
	printf("Stored values are: iflag %x, oflag %x, cflag %x, ospeed %x\n",tp->t_iflag, tp->t_oflag,\
		tp->t_cflag, tp->t_ospeed);
#endif
	return (0);
}

/*
 * Raise or lower modem control (DTR/RTS) signals.  If a character is
 * in transmission, the change is deferred.
 */
static void
zs_modem(cs, onoff)
	struct zs_chanstate *cs;
	int onoff;
{
	int s, bis, and;

	if (onoff) {
		bis = ZSWR5_DTR | ZSWR5_RTS;
		and = ~0;
	} else {
		bis = 0;
		and = ~(ZSWR5_DTR | ZSWR5_RTS);
	}
	s = splzs();
	cs->cs_preg[5] = (cs->cs_preg[5] | bis) & and;
	if (cs->cs_heldchange == 0) {
		if (cs->cs_ttyp->t_state & TS_BUSY) {
			cs->cs_heldtbc = cs->cs_tbc;
			cs->cs_tbc = 0;
			cs->cs_heldchange = 1;
		} else {
			cs->cs_creg[5] = (cs->cs_creg[5] | bis) & and;
			ZS_WRITE(cs->cs_zc, 5, cs->cs_creg[5]);
		}
	}
	splx(s);
}

/*
 * Write the given register set to the given zs channel in the proper order.
 * The channel must not be transmitting at the time.  The receiver will
 * be disabled for the time it takes to write all the registers.
 */
static void
zs_loadchannelregs(zc, reg)
	volatile struct zschan *zc;
	u_char *reg;
{
	int i;

	zc->zc_csr = ZSM_RESET_ERR;	/* reset error condition */
	ZS_DELAY();

#if 1	/* XXX - Is this really a good idea? -gwr */
	i = zc->zc_data;		/* drain fifo */
	ZS_DELAY();
	i = zc->zc_data;
	ZS_DELAY();
	i = zc->zc_data;
	ZS_DELAY();
#endif

	/* baud clock divisor, stop bits, parity */
	ZS_WRITE(zc, 4, reg[4]);

	/* misc. TX/RX control bits */
	ZS_WRITE(zc, 10, reg[10]);

	/* char size, enable (RX/TX) */
	ZS_WRITE(zc, 3, reg[3] & ~ZSWR3_RX_ENABLE);
	ZS_WRITE(zc, 5, reg[5] & ~ZSWR5_TX_ENABLE);

	/* interrupt enables: TX, TX, STATUS */
	ZS_WRITE(zc, 1, reg[1]);

	/* interrupt vector */
	ZS_WRITE(zc, 2, reg[2]);

	/* master interrupt control */
	ZS_WRITE(zc, 9, reg[9]);

	/* clock mode control */
	ZS_WRITE(zc, 11, reg[11]);

	/* baud rate (lo/hi) */
	ZS_WRITE(zc, 12, reg[12]);
	ZS_WRITE(zc, 13, reg[13]);

	/* Misc. control bits */
	ZS_WRITE(zc, 14, reg[14]);

	/* which lines cause status interrupts */
	ZS_WRITE(zc, 15, reg[15]| 1);
	ZS_WRITE(zc, 7, 0);
	ZS_WRITE(zc, 15, reg[15]);

	/* char size, enable (RX/TX)*/
	ZS_WRITE(zc, 3, reg[3]);
	ZS_WRITE(zc, 5, reg[5]);
#ifdef DEBUG
	printf("Params %x %x %x %x %x %x %x %x %x %x %x %x %x\n", reg[0], reg[1], reg[2], reg[3], \
			reg[4], reg[5], reg[9], reg[10], reg[11], reg[12], reg[13], reg[14], reg[15]);
#endif
}

static u_char
zs_read(zc, reg)
	volatile struct zschan *zc;
	u_char reg;
{
	u_char val;

	zc->zc_csr = reg;
	ZS_DELAY();
	val = zc->zc_csr;
	ZS_DELAY();
	return val;
}

static u_char
zs_write(zc, reg, val)
	volatile struct zschan *zc;
	u_char reg, val;
{
	zc->zc_csr = reg;
	ZS_DELAY();
	zc->zc_csr = val;
	ZS_DELAY();
	return val;
}

#ifdef KGDB
/*
 * Get a character from the given kgdb channel.  Called at splhigh().
 * XXX - Add delays, or combine with zscngetc()...
 */
static int
zs_kgdb_getc(arg)
	void *arg;
{
	register volatile struct zschan *zc = (volatile struct zschan *)arg;
	register int c, rr0;

	do {
		rr0 = zc->zc_csr;
		ZS_DELAY();
	} while ((rr0 & ZSRR0_RX_READY) == 0);
	c = zc->zc_data;
	ZS_DELAY();
	return (c);
}

/*
 * Put a character to the given kgdb channel.  Called at splhigh().
 */
static void
zs_kgdb_putc(arg, c)
	void *arg;
	int c;
{
	register volatile struct zschan *zc = (volatile struct zschan *)arg;
	register int c, rr0;

	do {
		rr0 = zc->zc_csr;
		ZS_DELAY();
	} while ((rr0 & ZSRR0_TX_READY) == 0);
	zc->zc_data = c;
	ZS_DELAY();
}

/*
 * Set up for kgdb; called at boot time before configuration.
 * KGDB interrupts will be enabled later when zs0 is configured.
 */
void
zs_kgdb_init()
{
	volatile struct zsdevice *addr;
	volatile struct zschan *zc;
	int unit, zs;

	if (major(kgdb_dev) != ZSMAJOR)
		return;
	unit = minor(kgdb_dev);
	/*
	 * Unit must be 0 or 1 (zs0).
	 */
	if ((unsigned)unit >= ZS_KBD) {
		printf("zs_kgdb_init: bad minor dev %d\n", unit);
		return;
	}
	zs = unit >> 1;
	unit &= 1;

	if (zsaddr[0] == NULL)
		panic("kbdb_attach: zs0 not yet mapped");
	addr = zsaddr[0];

	zc = (unit == 0) ?
		&addr->zs_chan[ZS_CHAN_A] :
		&addr->zs_chan[ZS_CHAN_B];
	zs_kgdb_savedspeed = zs_getspeed(zc);
	printf("zs_kgdb_init: attaching zs%d%c at %d baud\n",
	    zs, unit + 'a', kgdb_rate);
	zs_reset(zc, 1, kgdb_rate);
	kgdb_attach(zs_kgdb_getc, zs_kgdb_putc, (void *)zc);
}
#endif /* KGDB */

void	zsinit(void)
{
	volatile struct zschan	*zc;
	u_char  ch;

	zsaddr[0] = (struct zsdevice *)sccA;	/* get the base address of the chip */
	zsinitted = 1;

	zc=(volatile struct zschan *)zsaddr[0];
	ch=zc->zc_csr;
	ch=zc->zc_csr;
}

/*
 * Console functions.
 */
dev_t   mac68k_serdev;

sercnprobe(struct consdev * cp)
{
	int     maj, unit;

/*****
	for (maj = 0; maj < nchrdev; maj++) {
		if (cdevsw[maj].d_open == seropen) {
			break;
		}
	}
	if (maj == nchrdev)
		goto nosercon;

	cp->cn_pri = CN_NORMAL;	/* Lower than CN_INTERNAL *\
	if (mac68k_machine.serial_console & 0x01)
		cp->cn_pri = CN_REMOTE;	/* Higher than CN_INTERNAL *\

	unit = (mac68k_machine.serial_console & 0x02) ? 1 : 0;

	cp->cn_dev = makedev(maj, unit);

	mac68k_machine.serial_boot_echo = 0;
	return 0;

nosercon:
	if (mac68k_machine.serial_boot_echo) {
		/* major number doesn't really matter. *\
		mac68k_serdev = makedev(maj, 0);
		serinit(0);
	}
	return 0;
*****/
}

sercninit(struct consdev * cp)
{
	extern u_long	IOBase;

/*****
	mac68k_set_io_offsets(IOBase);
	serinit(0);
*****/
}

sercngetc(dev_t dev)
{
	return zscngetc(dev);
/*****
	int     unit, c;

	unit = UNIT(dev);

	while (!(SER_STATUS(unit, 0) & ZSRR0_RX_READY));
	c = SCCRDWR(unit);
	SER_STATUS(unit, 0) = ZSWR0_RESET_STATUS;

	return c;
*****/
}

sercnputc(dev_t dev, int c)
{
	return zscnputc(dev, c);
/*****
	int     unit;


	unit = UNIT(dev);

	while (!(SER_STATUS(unit, 0) & ZSRR0_TX_READY));
	SCCRDWR(unit) = c;
*****/
}