text: /*	$NetBSD: zs.c,v 1.9 1999/03/27 01:21:36 wrstuden Exp $	*/
  
  /*-
   * Copyright (c) 1996 The NetBSD Foundation, Inc.
   * All rights reserved.
   *
   * This code is derived from software contributed to The NetBSD Foundation
   * by Gordon W. Ross.
   *
   * 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 NetBSD
   *        Foundation, Inc. and its contributors.
   * 4. Neither the name of The NetBSD Foundation 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 NETBSD FOUNDATION, INC. AND CONTRIBUTORS
   * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
   * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
   * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
   * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
   * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
   * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   * POSSIBILITY OF SUCH DAMAGE.
   */
  
  /*
   * Zilog Z8530 Dual UART driver (machine-dependent part)
   *
   * Runs two serial lines per chip using slave drivers.
   * Plain tty/async lines use the zs_async slave.
   * Sun keyboard/mouse uses the zs_kbd/zs_ms slaves.
   */
  
  #include "opt_ddb.h"
  
  #include <sys/param.h>
  #include <sys/systm.h>
  #include <sys/conf.h>
  #include <sys/device.h>
  #include <sys/file.h>
  #include <sys/ioctl.h>
  #include <sys/kernel.h>
  #include <sys/proc.h>
  #include <sys/tty.h>
  #include <sys/time.h>
  #include <sys/syslog.h>
  
  #include <machine/autoconf.h>
  #include <machine/openfirm.h>
  #include <machine/bsd_openprom.h>
  #include <machine/conf.h>
  #include <machine/cpu.h>
  #include <machine/eeprom.h>
  #include <machine/psl.h>
  #include <machine/z8530var.h>
  
  #include <dev/cons.h>
  #include <dev/ic/z8530reg.h>
  
  #include <sparc64/sparc64/vaddrs.h>
  #include <sparc64/sparc64/auxreg.h>
  #include <sparc64/dev/cons.h>
  
  #include "kbd.h"	/* NKBD */
  #include "zs.h" 	/* NZS */
  
  /* Make life easier for the initialized arrays here. */
  #if NZS < 3
  #undef  NZS
  #define NZS 3
  #endif
  
  /*
   * Some warts needed by z8530tty.c -
   * The default parity REALLY needs to be the same as the PROM uses,
   * or you can not see messages done with printf during boot-up...
   */
  int zs_def_cflag = (CREAD | CS8 | HUPCL);
  int zs_major = 12;
  
  /*
   * The Sun provides a 4.9152 MHz clock to the ZS chips.
   */
  #define PCLK	(9600 * 512)	/* PCLK pin input clock rate */
  
  /*
   * Select software interrupt bit based on TTY ipl.
   */
  #if PIL_TTY == 1
  # define IE_ZSSOFT IE_L1
  #elif PIL_TTY == 4
  # define IE_ZSSOFT IE_L4
  #elif PIL_TTY == 6
  # define IE_ZSSOFT IE_L6
  #else
  # error "no suitable software interrupt bit"
  #endif
  
  #define	ZS_DELAY()		(0)
  
  /* The layout of this is hardware-dependent (padding, order). */
  struct zschan {
  	volatile u_char	zc_csr;		/* ctrl,status, and indirect access */
  	u_char		zc_xxx0;
  	volatile u_char	zc_data;	/* data */
  	u_char		zc_xxx1;
  };
  struct zsdevice {
  	/* Yes, they are backwards. */
  	struct	zschan zs_chan_b;
  	struct	zschan zs_chan_a;
  };
  
  /* Saved PROM mappings */
  static struct zsdevice *zsaddr[NZS];
  
  /* Flags from cninit() */
  static int zs_hwflags[NZS][2];
  
  /* Default speed for each channel */
  static int zs_defspeed[NZS][2] = {
  	{ 9600, 	/* ttya */
  	  9600 },	/* ttyb */
  	{ 1200, 	/* keyboard */
  	  1200 },	/* mouse */
  	{ 9600, 	/* ttyc */
  	  9600 },	/* ttyd */
  };
  
  static u_char zs_init_reg[16] = {
  	0,	/* 0: CMD (reset, etc.) */
  	0,	/* 1: No interrupts yet. */
  	0,	/* 2: 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 */
  	ZSWR9_MASTER_IE | ZSWR9_NO_VECTOR,
  	0,	/*10: Misc. TX/RX control bits */
  	ZSWR11_TXCLK_BAUD | ZSWR11_RXCLK_BAUD,
  	((PCLK/32)/9600)-2,	/*12: BAUDLO (default=9600) */
  	0,			/*13: BAUDHI (default=9600) */
  	ZSWR14_BAUD_ENA | ZSWR14_BAUD_FROM_PCLK,
  	ZSWR15_BREAK_IE,
  };
  
  struct zschan *
  zs_get_chan_addr(zs_unit, channel)
  	int zs_unit, channel;
  {
  	struct zsdevice	*addr;
  	struct zschan	*zc;
  
  	if (zs_unit >= NZS)
  		return (NULL);
  	addr = zsaddr[zs_unit];
  	if (addr == NULL)
  		addr = zsaddr[zs_unit] = findzs(zs_unit);
  	if (addr == NULL)
  		return (NULL);
  	if (channel == 0) {
  		zc = &addr->zs_chan_a;
  	} else {
  		zc = &addr->zs_chan_b;
  	}
  	return (zc);
  }
  
  
  /****************************************************************
   * Autoconfig
   ****************************************************************/
  
  /* Definition of the driver for autoconfig. */
  static int  zs_match_sbus __P((struct device *, struct cfdata *, void *));
  static int  zs_match_mainbus __P((struct device *, struct cfdata *, void *));
  static int  zs_match_obio __P((struct device *, struct cfdata *, void *));
  static void zs_attach_sbus __P((struct device *, struct device *, void *));
  static void zs_attach_mainbus __P((struct device *, struct device *, void *));
  static void zs_attach_obio __P((struct device *, struct device *, void *));
  
  static void zs_attach __P((struct zsc_softc *, int));
  static int  zs_print __P((void *, const char *name));
  
  struct cfattach zs_ca = {
  	sizeof(struct zsc_softc), zs_match_sbus, zs_attach_sbus
  };
  
  struct cfattach zs_mainbus_ca = {
  	sizeof(struct zsc_softc), zs_match_mainbus, zs_attach_mainbus
  };
  
  struct cfattach zs_obio_ca = {
  	sizeof(struct zsc_softc), zs_match_obio, zs_attach_obio
  };
  
  extern struct cfdriver zs_cd;
  
  /* Interrupt handlers. */
  static int zshard __P((void *));
  static int zssoft __P((void *));
  static struct intrhand levelsoft = { zssoft };
  
  static int zs_get_speed __P((struct zs_chanstate *));
  
  
  /*
   * Is the zs chip present?
   */
  static int
  zs_match_mainbus(parent, cf, aux)
  	struct device *parent;
  	struct cfdata *cf;
  	void *aux;
  {
  	struct mainbus_attach_args *ma = aux;
  
  	if (strcmp(cf->cf_driver->cd_name, ma->ma_name) != 0)
  		return (0);
  
  	return (getpropint(ma->ma_node, "slave", -2) == cf->cf_unit);
  }
  
  static int
  zs_match_sbus(parent, cf, aux)
  	struct device *parent;
  	struct cfdata *cf;
  	void *aux;
  {
  	struct sbus_attach_args *sa = aux;
  
  	if (strcmp(cf->cf_driver->cd_name, sa->sa_name) != 0)
  		return (0);
  
  	return 1;
  }
  
  static int
  zs_match_obio(parent, cf, aux)
  	struct device *parent;
  	struct cfdata *cf;
  	void *aux;
  {
  #ifdef SUN4U
  	return 0;
  #else
  	union obio_attach_args *uoba = aux;
  	struct obio4_attach_args *oba;
  
  	if (uoba->uoba_isobio4 == 0) {
  		struct sbus_attach_args *sa = &uoba->uoba_sbus;
  
  		if (strcmp(cf->cf_driver->cd_name, sa->sa_name) != 0)
  			return (0);
  
  		return (getpropint(sa->sa_node, "slave", -2) == cf->cf_unit);
  	}
  
  	oba = &uoba->uoba_oba4;
  	return (bus_space_probe(oba->oba_bustag, 0, oba->oba_paddr,
  			        1, 0, 0, NULL, NULL));
  #endif
  }
  
  static void
  zs_attach_mainbus(parent, self, aux)
  	struct device *parent;
  	struct device *self;
  	void *aux;
  {
  #ifdef SUN4U
  	return 0;
  #else
  	struct zsc_softc *zsc = (void *) self;
  	struct mainbus_attach_args *ma = aux;
  	int zs_unit = zsc->zsc_dev.dv_unit;
  
  	zsc->zsc_bustag = ma->ma_bustag;
  	zsc->zsc_dmatag = ma->ma_dmatag;
  
  	/* Use the mapping setup by the Sun PROM. */
  	if (zsaddr[zs_unit] == NULL)
  		zsaddr[zs_unit] = findzs(zs_unit);
  	if ((void*)zsaddr[zs_unit] != (void*)(u_long)ma->ma_address[0])
  		panic("zsattach_mainbus");
  	zs_attach(zsc, ma->ma_pri);
  #endif
  }
  
  
  static void
  zs_attach_sbus(parent, self, aux)
  	struct device *parent;
  	struct device *self;
  	void *aux;
  {
  	struct zsc_softc *zsc = (void *) self;
  	struct sbus_attach_args *sa = aux;
  	int zs_unit = zsc->zsc_dev.dv_unit;
  
  	zsc->zsc_bustag = sa->sa_bustag;
  	zsc->zsc_dmatag = sa->sa_dmatag;
  
  	/* Use the mapping setup by the Sun PROM. */
  	if (zsaddr[zs_unit] == NULL)
  		zsaddr[zs_unit] = findzs(zs_unit);
  	zs_attach(zsc, sa->sa_pri);
  }
  
  static void
  zs_attach_obio(parent, self, aux)
  	struct device *parent;
  	struct device *self;
  	void *aux;
  {
  #ifndef SUN4U
  	struct zsc_softc *zsc = (void *) self;
  	union obio_attach_args *uoba = aux;
  	int zs_unit = zsc->zsc_dev.dv_unit;
  
  	/* Use the mapping setup by the Sun PROM. */
  	if (zsaddr[zs_unit] == NULL)
  		zsaddr[zs_unit] = findzs(zs_unit);
  
  	if (uoba->uoba_isobio4 == 0) {
  		struct sbus_attach_args *sa = &uoba->uoba_sbus;
  		zsc->zsc_bustag = sa->sa_bustag;
  		zsc->zsc_dmatag = sa->sa_dmatag;
  		zs_attach(zsc, sa->sa_pri);
  	} else {
  		struct obio4_attach_args *oba = &uoba->uoba_oba4;
  		zsc->zsc_bustag = oba->oba_bustag;
  		zsc->zsc_dmatag = oba->oba_dmatag;
  		zs_attach(zsc, oba->oba_pri);
  	}
  #endif
  }
  /*
   * 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(zsc, pri)
  	struct zsc_softc *zsc;
  	int pri;
  {
  	struct zsc_attach_args zsc_args;
  	volatile struct zschan *zc;
  	struct zs_chanstate *cs;
  	int s, zs_unit, channel;
  	static int didintr, prevpri;
  
  	printf(" softpri %d\n", PIL_TTY);
  
  	/*
  	 * Initialize software state for each channel.
  	 */
  	zs_unit = zsc->zsc_dev.dv_unit;
  	for (channel = 0; channel < 2; channel++) {
  		zsc_args.channel = channel;
  		zsc_args.hwflags = zs_hwflags[zs_unit][channel];
  		cs = &zsc->zsc_cs_store[channel];
  		zsc->zsc_cs[channel] = cs;
  
  		cs->cs_channel = channel;
  		cs->cs_private = NULL;
  		cs->cs_ops = &zsops_null;
  		cs->cs_brg_clk = PCLK / 16;
  
  		zc = zs_get_chan_addr(zs_unit, channel);
  		cs->cs_reg_csr  = &zc->zc_csr;
  		cs->cs_reg_data = &zc->zc_data;
  
  		bcopy(zs_init_reg, cs->cs_creg, 16);
  		bcopy(zs_init_reg, cs->cs_preg, 16);
  
  		/* XXX: Get these from the PROM properties! */
  		/* XXX: See the mvme167 code.  Better. */
  		if (zsc_args.hwflags & ZS_HWFLAG_CONSOLE)
  			cs->cs_defspeed = zs_get_speed(cs);
  		else
  			cs->cs_defspeed = zs_defspeed[zs_unit][channel];
  		cs->cs_defcflag = zs_def_cflag;
  
  		/* Make these correspond to cs_defcflag (-crtscts) */
  		cs->cs_rr0_dcd = ZSRR0_DCD;
  		cs->cs_rr0_cts = 0;
  		cs->cs_wr5_dtr = ZSWR5_DTR | ZSWR5_RTS;
  		cs->cs_wr5_rts = 0;
  
  		/*
  		 * Clear the master interrupt enable.
  		 * The INTENA is common to both channels,
  		 * so just do it on the A channel.
  		 */
  		if (channel == 0) {
  			zs_write_reg(cs, 9, 0);
  		}
  
  		/*
  		 * Look for a child driver for this channel.
  		 * The child attach will setup the hardware.
  		 */
  		if (!config_found(&zsc->zsc_dev, (void *)&zsc_args, zs_print)) {
  			/* No sub-driver.  Just reset it. */
  			u_char reset = (channel == 0) ?
  				ZSWR9_A_RESET : ZSWR9_B_RESET;
  			s = splzs();
  			zs_write_reg(cs,  9, reset);
  			splx(s);
  		}
  	}
  
  	/*
  	 * Now safe to install interrupt handlers.  Note the arguments
  	 * to the interrupt handlers aren't used.  Note, we only do this
  	 * once since both SCCs interrupt at the same level and vector.
  	 */
  	if (!didintr) {
  		didintr = 1;
  		prevpri = pri;
  		bus_intr_establish(zsc->zsc_bustag, pri, 0, zshard, NULL);
  		intr_establish(PIL_TTY, &levelsoft);
  	} else if (pri != prevpri)
  		panic("broken zs interrupt scheme");
  
  	evcnt_attach(&zsc->zsc_dev, "intr", &zsc->zsc_intrcnt);
  
  	/*
  	 * Set the master interrupt enable and interrupt vector.
  	 * (common to both channels, do it on A)
  	 */
  	cs = zsc->zsc_cs[0];
  	s = splhigh();
  	/* interrupt vector */
  	zs_write_reg(cs, 2, zs_init_reg[2]);
  	/* master interrupt control (enable) */
  	zs_write_reg(cs, 9, zs_init_reg[9]);
  	splx(s);
  
  #if 0
  	/*
  	 * XXX: L1A hack - We would like to be able to break into
  	 * the debugger during the rest of autoconfiguration, so
  	 * lower interrupts just enough to let zs interrupts in.
  	 * This is done after both zs devices are attached.
  	 */
  	if (zs_unit == 1) {
  		printf("zs1: enabling zs interrupts\n");
  		(void)splfd(); /* XXX: splzs - 1 */
  	}
  #endif
  }
  
  static int
  zs_print(aux, name)
  	void *aux;
  	const char *name;
  {
  	struct zsc_attach_args *args = aux;
  
  	if (name != NULL)
  		printf("%s: ", name);
  
  	if (args->channel != -1)
  		printf(" channel %d", args->channel);
  
  	return (UNCONF);
  }
  
  static volatile int zssoftpending;
  
  /*
   * Our ZS chips all share a common, autovectored interrupt,
   * so we have to look at all of them on each interrupt.
   */
  static int
  zshard(arg)
  	void *arg;
  {
  	register struct zsc_softc *zsc;
  	register int unit, rr3, rval, softreq;
  
  	rval = softreq = 0;
  	for (unit = 0; unit < zs_cd.cd_ndevs; unit++) {
  		zsc = zs_cd.cd_devs[unit];
  		if (zsc == NULL)
  			continue;
  		rr3 = zsc_intr_hard(zsc);
  		/* Count up the interrupts. */
  		if (rr3) {
  			rval |= rr3;
  			zsc->zsc_intrcnt.ev_count++;
  		}
  		softreq |= zsc->zsc_cs[0]->cs_softreq;
  		softreq |= zsc->zsc_cs[1]->cs_softreq;
  	}
  
  	/* We are at splzs here, so no need to lock. */
  	if (softreq && (zssoftpending == 0)) {
  		zssoftpending = IE_ZSSOFT;
  #if defined(SUN4M)
  		if (CPU_ISSUN4M)
  			raise(0, PIL_TTY);
  		else
  #endif
  			ienab_bis(IE_ZSSOFT);
  	}
  	return (rval);
  }
  
  /*
   * Similar scheme as for zshard (look at all of them)
   */
  static int
  zssoft(arg)
  	void *arg;
  {
  	register struct zsc_softc *zsc;
  	register int s, unit;
  
  	/* This is not the only ISR on this IPL. */
  	if (zssoftpending == 0)
  		return (0);
  
  	/*
  	 * 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.
  	 */
  	/* ienab_bic(IE_ZSSOFT); */
  	zssoftpending = 0;
  
  	/* Make sure we call the tty layer at spltty. */
  	s = spltty();
  	for (unit = 0; unit < zs_cd.cd_ndevs; unit++) {
  		zsc = zs_cd.cd_devs[unit];
  		if (zsc == NULL)
  			continue;
  		(void)zsc_intr_soft(zsc);
  	}
  	splx(s);
  	return (1);
  }
  
  
  /*
   * Compute the current baud rate given a ZS channel.
   */
  static int
  zs_get_speed(cs)
  	struct zs_chanstate *cs;
  {
  	int tconst;
  
  	tconst = zs_read_reg(cs, 12);
  	tconst |= zs_read_reg(cs, 13) << 8;
  	return (TCONST_TO_BPS(cs->cs_brg_clk, tconst));
  }
  
  /*
   * MD functions for setting the baud rate and control modes.
   */
  int
  zs_set_speed(cs, bps)
  	struct zs_chanstate *cs;
  	int bps;	/* bits per second */
  {
  	int tconst, real_bps;
  
  	if (bps == 0)
  		return (0);
  
  #ifdef	DIAGNOSTIC
  	if (cs->cs_brg_clk == 0)
  		panic("zs_set_speed");
  #endif
  
  	tconst = BPS_TO_TCONST(cs->cs_brg_clk, bps);
  	if (tconst < 0)
  		return (EINVAL);
  
  	/* Convert back to make sure we can do it. */
  	real_bps = TCONST_TO_BPS(cs->cs_brg_clk, tconst);
  
  	/* XXX - Allow some tolerance here? */
  	if (real_bps != bps)
  		return (EINVAL);
  
  	cs->cs_preg[12] = tconst;
  	cs->cs_preg[13] = tconst >> 8;
  
  	/* Caller will stuff the pending registers. */
  	return (0);
  }
  
  int
  zs_set_modes(cs, cflag)
  	struct zs_chanstate *cs;
  	int cflag;	/* bits per second */
  {
  	int s;
  
  	/*
  	 * Output hardware flow control on the chip is horrendous:
  	 * if carrier detect drops, the receiver is disabled, and if
  	 * CTS drops, the transmitter is stoped IN MID CHARACTER!
  	 * Therefore, NEVER set the HFC bit, and instead use the
  	 * status interrupt to detect CTS changes.
  	 */
  	s = splzs();
  	cs->cs_rr0_pps = 0;
  	if ((cflag & (CLOCAL | MDMBUF)) != 0) {
  		cs->cs_rr0_dcd = 0;
  		if ((cflag & MDMBUF) == 0)
  			cs->cs_rr0_pps = ZSRR0_DCD;
  	} else
  		cs->cs_rr0_dcd = ZSRR0_DCD;
  	if ((cflag & CRTSCTS) != 0) {
  		cs->cs_wr5_dtr = ZSWR5_DTR;
  		cs->cs_wr5_rts = ZSWR5_RTS;
  		cs->cs_rr0_cts = ZSRR0_CTS;
  	} else if ((cflag & CDTRCTS) != 0) {
  		cs->cs_wr5_dtr = 0;
  		cs->cs_wr5_rts = ZSWR5_DTR;
  		cs->cs_rr0_cts = ZSRR0_CTS;
  	} else if ((cflag & MDMBUF) != 0) {
  		cs->cs_wr5_dtr = 0;
  		cs->cs_wr5_rts = ZSWR5_DTR;
  		cs->cs_rr0_cts = ZSRR0_DCD;
  	} else {
  		cs->cs_wr5_dtr = ZSWR5_DTR | ZSWR5_RTS;
  		cs->cs_wr5_rts = 0;
  		cs->cs_rr0_cts = 0;
  	}
  	splx(s);
  
  	/* Caller will stuff the pending registers. */
  	return (0);
  }
  
  
  /*
   * Read or write the chip with suitable delays.
   */
  
  u_char
  zs_read_reg(cs, reg)
  	struct zs_chanstate *cs;
  	u_char reg;
  {
  	u_char val;
  
  	*cs->cs_reg_csr = reg;
  	ZS_DELAY();
  	val = *cs->cs_reg_csr;
  	ZS_DELAY();
  	return (val);
  }
  
  void
  zs_write_reg(cs, reg, val)
  	struct zs_chanstate *cs;
  	u_char reg, val;
  {
  	*cs->cs_reg_csr = reg;
  	ZS_DELAY();
  	*cs->cs_reg_csr = val;
  	ZS_DELAY();
  }
  
  u_char
  zs_read_csr(cs)
  	struct zs_chanstate *cs;
  {
  	register u_char val;
  
  	val = *cs->cs_reg_csr;
  	ZS_DELAY();
  	return (val);
  }
  
  void  zs_write_csr(cs, val)
  	struct zs_chanstate *cs;
  	u_char val;
  {
  	*cs->cs_reg_csr = val;
  	ZS_DELAY();
  }
  
  u_char zs_read_data(cs)
  	struct zs_chanstate *cs;
  {
  	register u_char val;
  
  	val = *cs->cs_reg_data;
  	ZS_DELAY();
  	return (val);
  }
  
  void  zs_write_data(cs, val)
  	struct zs_chanstate *cs;
  	u_char val;
  {
  	*cs->cs_reg_data = val;
  	ZS_DELAY();
  }
  
  /****************************************************************
   * Console support functions (Sun specific!)
   * Note: this code is allowed to know about the layout of
   * the chip registers, and uses that to keep things simple.
   * XXX - I think I like the mvme167 code better. -gwr
   ****************************************************************/
  
  extern void Debugger __P((void));
  void *zs_conschan;
  
  /*
   * Handle user request to enter kernel debugger.
   */
  void
  zs_abort(cs)
  	struct zs_chanstate *cs;
  {
  	register volatile struct zschan *zc = zs_conschan;
  	int rr0;
  
  	/* Wait for end of break to avoid PROM abort. */
  	/* XXX - Limit the wait? */
  	do {
  		rr0 = zc->zc_csr;
  		ZS_DELAY();
  	} while (rr0 & ZSRR0_BREAK);
  
  #if defined(KGDB)
  	zskgdb(cs);
  #elif defined(DDB)
  	Debugger();
  #else
  	printf("stopping on keyboard abort\n");
  	callrom();
  #endif
  }
  
  /*
   * Polled input char.
   */
  int
  zs_getc(arg)
  	void *arg;
  {
  	register volatile struct zschan *zc = arg;
  	register int s, c, rr0;
  
  	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 output char.
   */
  void
  zs_putc(arg, c)
  	void *arg;
  	int c;
  {
  	register volatile struct zschan *zc = arg;
  	register int s, rr0;
  
  	s = splhigh();
  
  	/* Wait for transmitter to become ready. */
  	do {
  		rr0 = zc->zc_csr;
  		ZS_DELAY();
  	} while ((rr0 & ZSRR0_TX_READY) == 0);
  
  	/*
  	 * Send the next character.
  	 * Now you'd think that this could be followed by a ZS_DELAY()
  	 * just like all the other chip accesses, but it turns out that
  	 * the `transmit-ready' interrupt isn't de-asserted until
  	 * some period of time after the register write completes
  	 * (more than a couple instructions).  So to avoid stray
  	 * interrupts we put in the 2us delay regardless of cpu model.
  	 */
  	zc->zc_data = c;
  	delay(2);
  
  	splx(s);
  }
  
  /*****************************************************************/
  
  static void zscninit __P((struct consdev *));
  static int  zscngetc __P((dev_t));
  static void zscnputc __P((dev_t, int));
  static void zscnpollc __P((dev_t, int));
  /*
   * Console table shared by ttya, ttyb
   */
  struct consdev consdev_tty = {
  	nullcnprobe,
  	zscninit,
  	zscngetc,
  	zscnputc,
  	zscnpollc,
  };
  
  static void
  zscninit(cn)
  	struct consdev *cn;
  {
  }
  
  /*
   * Polled console input putchar.
   */
  static int
  zscngetc(dev)
  	dev_t dev;
  {
  	return (zs_getc(zs_conschan));
  }
  
  /*
   * Polled console output putchar.
   */
  static void
  zscnputc(dev, c)
  	dev_t dev;
  	int c;
  {
  	zs_putc(zs_conschan, c);
  }
  
  int swallow_zsintrs;
  
  static void
  zscnpollc(dev, on)
  	dev_t dev;
  	int on;
  {
  	/* 
  	 * Need to tell zs driver to acknowledge all interrupts or we get
  	 * annoying spurious interrupt messages.  This is because mucking
  	 * with spl() levels during polling does not prevent interrupts from
  	 * being generated.
  	 */
  
  	if (on) swallow_zsintrs++;
  	else swallow_zsintrs--;
  }
  
  /*****************************************************************/
  
  static void prom_cninit __P((struct consdev *));
  static int  prom_cngetc __P((dev_t));
  static void prom_cnputc __P((dev_t, int));
  
  int stdin = NULL, stdout = NULL;
  
  /*
   * The console is set to this one initially,
   * which lets us use the PROM until consinit()
   * is called to select a real console.
   */
  struct consdev consdev_prom = {
  	nullcnprobe,
  	prom_cninit,
  	prom_cngetc,
  	prom_cnputc,
  	nullcnpollc,
  };
  
  /*
   * The console table pointer is statically initialized
   * to point to the PROM (output only) table, so that
   * early calls to printf will work.
   */
  struct consdev *cn_tab = &consdev_prom;
  
  void
  nullcnprobe(cn)
  	struct consdev *cn;
  {
  }
  
  static void
  prom_cninit(cn)
  	struct consdev *cn;
  {
  }
  
  /*
   * PROM console input putchar.
   * (dummy - this is output only)
   */
  static int
  prom_cngetc(dev)
  	dev_t dev;
  {
  	int s;
  	char c0;
  
  	if (!stdin) {
  		int node = OF_finddevice("/chosen");
  		OF_getprop(node, "stdin",  &stdin, sizeof(stdin));
  	}
  	if (OF_read(stdin, &c0, 1) == 1)
  		return (c0 & 0x7f);
  	return -1;
  }
  
  /*
   * PROM console output putchar.
   */
  static void
  prom_cnputc(dev, c)
  	dev_t dev;
  	int c;
  {
  	int s;
  	char c0 = (c & 0x7f);
  
  	if (!stdout) {
  		int node = OF_finddevice("/chosen");
  		OF_getprop(node, "stdout",  &stdout, sizeof(stdout));
  	}
  
  	s = splhigh();
  	OF_write(stdout, &c0, 1);
  	splx(s);
  }
  
  /*****************************************************************/
  
  extern struct consdev consdev_kd;
  
  static char *prom_inSrc_name[] = {
  	"keyboard/display",
  	"ttya", "ttyb",
  	"ttyc", "ttyd" };
  
  #ifdef	DEBUG
  #define	DBPRINT(x)	printf x
  #else
  #define	DBPRINT(x)
  #endif
  
  /*
   * This function replaces sys/dev/cninit.c
   * Determine which device is the console using
   * the PROM "input source" and "output sink".
   */
  void
  consinit()
  {
  	struct zschan *zc;
  	struct consdev *cn;
  	int channel, zs_unit, zstty_unit;
  	int inSource, outSink;
  	register int node;
  	char buffer[128];
  	register char *cp;
  	extern int fbnode;
  
  	DBPRINT(("consinit()\r\n"));
  	if (cn_tab != &consdev_prom) return;
  
  	inSource = outSink = -1;
  	
  	DBPRINT(("setting up stdin\r\n"));
  	node = OF_finddevice("/chosen");
  	OF_getprop(node, "stdin",  &stdin, sizeof(stdin));
  	DBPRINT(("stdin instance = %x\r\n", stdin));
  
  	node = OF_instance_to_package(stdin);
  	DBPRINT(("stdin package = %x\r\n", node));
  	if (OF_getproplen(node,"keyboard") >= 0) {
  		inSource = PROMDEV_KBD;
  		goto setup_output;
  	}
  	if (strcmp(getpropstring(node,"device_type"),"serial") != 0) {
  		/* not a serial, not keyboard. what is it?!? */
  		inSource = -1;
  		goto setup_output;
  	}
  	/*
  	 * At this point we assume the device path is in the form
  	 *   ....device@x,y:a for ttya and ...device@x,y:b for ttyb.
  	 * If it isn't, we defer to the ROM
  	 */
  	if(OF_instance_to_path(stdin, buffer, sizeof(buffer)) <= 0) {
  		printf("consinit: bogus stdin path.\n");
  		goto setup_output;
  	}
  	cp = buffer;
  	while (*cp)
  		cp++;
  	cp -= 2;
  #ifdef DEBUG
  	if (cp < buffer)
  		panic("consinit: bad stdin path %s",buffer);
  #endif
  	/* XXX: only allows tty's a->z, assumes PROMDEV_TTYx contig */
  	if (cp[0]==':' && cp[1] >= 'a' && cp[1] <= 'z')
  		inSource = PROMDEV_TTYA + (cp[1] - 'a');
  	/* else use rom */
  setup_output:
  	DBPRINT(("setting up stdout\r\n"));
  	node = OF_finddevice("/chosen");
  	OF_getprop(node, "stdout", &stdout, sizeof(stdout));
  	
  	DBPRINT(("stdout instance = %x\r\n", stdout));
  
  	node = OF_instance_to_package(stdout);
  	DBPRINT(("stdout package = %x\r\n", node));
  	if (strcmp(getpropstring(node,"device_type"),"display") == 0) {
  		/* frame buffer output */
  		outSink = PROMDEV_SCREEN;
  		fbnode = node;
  	} else if (strcmp(getpropstring(node,"device_type"), "serial")
  		   != 0) {
  		/* not screen, not serial. Whatzit? */
  		outSink = -1;
  	} else { /* serial console. which? */
  		/*
  		 * At this point we assume the device path is in the
  		 * form:
  		 * ....device@x,y:a for ttya, etc.
  		 * If it isn't, we defer to the ROM
  		 */
  		if(OF_instance_to_path(stdout, buffer, sizeof(buffer)) <= 0) {
  			printf("consinit: bogus stdin path.\n");
  			goto setup_output;
  		}
  		cp = buffer;
  		while (*cp)
  			cp++;
  		cp -= 2;
  #ifdef DEBUG
  		if (cp < buffer)
  			panic("consinit: bad stdout path %s",buffer);
  #endif
  		/* XXX: only allows tty's a->z, assumes PROMDEV_TTYx contig */
  		if (cp[0]==':' && cp[1] >= 'a' && cp[1] <= 'z')
  			outSink = PROMDEV_TTYA + (cp[1] - 'a');
  		else outSink = -1;
  	}	
  	if (inSource != outSink) {
  		printf("cninit: mismatched PROM output selector\n");
  	}
  
  	switch (inSource) {
  	default:
  		printf("cninit: invalid inSource=%d\n", inSource);
  		callrom();
  		inSource = PROMDEV_KBD;
  		/* fall through */
  
  	case 0:	/* keyboard/display */
  #if NKBD > 0
  		zs_unit = 1;	/* XXX - config info! */
  		channel = 0;
  		cn = &consdev_kd;
  		/* Set cn_dev, cn_pri in kd.c */
  		break;
  #else	/* NKBD */
  		printf("cninit: kdb/display not configured\n");
  		callrom();
  		inSource = PROMDEV_TTYA;
  		/* fall through */
  #endif	/* NKBD */
  
  	case PROMDEV_TTYA:
  	case PROMDEV_TTYB:
  		zstty_unit = inSource - PROMDEV_TTYA;
  		zs_unit = 0;	/* XXX - config info! */
  		channel = zstty_unit & 1;
  		cn = &consdev_tty;
  		cn->cn_dev = makedev(zs_major, zstty_unit);
  		cn->cn_pri = CN_REMOTE;
  		break;
  
  	}
  	/* Now that inSource has been validated, print it. */
  	printf("console is %s\n", prom_inSrc_name[inSource]);
  
  	zc = zs_get_chan_addr(zs_unit, channel);
  	if (zc == NULL) {
  		printf("cninit: zs not mapped.\n");
  		return;
  	}
  	zs_conschan = zc;
  	zs_hwflags[zs_unit][channel] = ZS_HWFLAG_CONSOLE;
  	cn_tab = cn;
  	(*cn->cn_init)(cn);
  #ifdef	KGDB
  	zs_kgdb_init();
  #endif
  }
  