Home | History | Annotate | Line # | Download | only in dev
zs.c revision 1.8
      1 /*	$NetBSD: zs.c,v 1.8 1996/09/16 05:24:21 scottr Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1995 Gordon W. Ross
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. The name of the author may not be used to endorse or promote products
     16  *    derived from this software without specific prior written permission.
     17  * 4. All advertising materials mentioning features or use of this software
     18  *    must display the following acknowledgement:
     19  *      This product includes software developed by Gordon Ross
     20  *
     21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     22  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     23  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     24  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     26  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     27  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     28  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     29  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     30  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     31  */
     32 
     33 /*
     34  * Zilog Z8530 Dual UART driver (machine-dependent part)
     35  *
     36  * Runs two serial lines per chip using slave drivers.
     37  * Plain tty/async lines use the zs_async slave.
     38  * Sun keyboard/mouse uses the zs_kbd/zs_ms slaves.
     39  */
     40 
     41 #include <sys/param.h>
     42 #include <sys/systm.h>
     43 #include <sys/proc.h>
     44 #include <sys/device.h>
     45 #include <sys/conf.h>
     46 #include <sys/file.h>
     47 #include <sys/ioctl.h>
     48 #include <sys/tty.h>
     49 #include <sys/time.h>
     50 #include <sys/kernel.h>
     51 #include <sys/syslog.h>
     52 
     53 #include <dev/cons.h>
     54 #include "z8530reg.h"
     55 #include <machine/z8530var.h>
     56 
     57 #include <machine/autoconf.h>
     58 #include <machine/cpu.h>
     59 #include <machine/viareg.h>
     60 
     61 /*
     62  * XXX: Hard code this to make console init easier...
     63  */
     64 #define	NZSC	1		/* XXX */
     65 
     66 /*
     67  * Define interrupt levels.
     68  */
     69 #define ZSHARD_PRI	6	/* Wired on the CPU board... */
     70 #define ZSSOFT_PRI	3	/* Want tty pri (4) but this is OK. */
     71 
     72 /* The layout of this is hardware-dependent (padding, order). */
     73 struct zschan {
     74 	volatile u_char	zc_csr;		/* ctrl,status, and indirect access */
     75 	u_char		zc_xxx0;
     76 	u_char		zc_xxx1;
     77 	u_char		zc_xxx2;
     78 	volatile u_char	zc_data;	/* data */
     79 	u_char		zc_xxx3;
     80 	u_char		zc_xxx4;
     81 	u_char		zc_xxx5;
     82 };
     83 /*
     84  * The zsdevice structure is not used on the mac68k port as the
     85  * chip is wired up weird. Channel B & A are interspursed with
     86  * the data & control bytes
     87 struct zsdevice {
     88 	/! Yes, they are backwards. !/
     89 	struct	zschan zs_chan_b;
     90 	struct	zschan zs_chan_a;
     91 };
     92 */
     93 
     94 /* Saved PROM mappings */
     95 static char *zsaddr[NZSC];	/* See zs_init() */
     96 /* Flags from cninit() */
     97 static int zs_hwflags[NZSC][2];
     98 /* Default speed for each channel */
     99 static int zs_defspeed[NZSC][2] = {
    100 	{ 9600, 	/* tty00 */
    101 	  9600 },	/* tty01 */
    102 };
    103 /* console stuff */
    104 void *zs_conschan = 0;
    105 int   zs_consunit;
    106 /* device that the console is attached to--if serial. */
    107 dev_t	mac68k_zsdev;
    108 /* Mac stuff, some vestages of old mac serial driver here */
    109 volatile unsigned char *sccA = 0;
    110 
    111 static struct zschan	*zs_get_chan_addr __P((int zsc_unit, int channel));
    112 void			zs_init __P((void));
    113 
    114 static struct zschan *
    115 zs_get_chan_addr(zsc_unit, channel)
    116 	int zsc_unit, channel;
    117 {
    118 	char *addr;
    119 	struct zschan *zc;
    120 
    121 	if (zsc_unit >= NZSC)
    122 		return NULL;
    123 	addr = zsaddr[zsc_unit];
    124 	if (addr == NULL)
    125 		return NULL;
    126 	if (channel == 0) {
    127 		zc = (struct zschan *)(addr +2);
    128 		/* handle the fact the ports are intertwined. */
    129 	} else {
    130 		zc = (struct zschan *)(addr);
    131 	}
    132 	return (zc);
    133 }
    134 
    135 
    136 /* Find PROM mappings (for console support). */
    137 static int zsinited = 0; /* 0 = not, 1 = inited, not attached, 2= attached */
    138 
    139 void
    140 zs_init()
    141 {
    142 	if ((zsinited == 2)&&(zsaddr[0] != (char *) sccA))
    143 		panic("Moved zs0 address after attached!");
    144 	zsaddr[0] = (char *) sccA;
    145 	zsinited = 1;
    146 	if (zs_conschan != 0){ /* we might have moved io under the console */
    147 		zs_conschan = zs_get_chan_addr(0, zs_consunit);
    148 		/* so recalc the console port */
    149 	}
    150 }
    151 
    152 
    153 /*
    154  * Even though zsparam will set up the clock multiples, etc., we
    155  * still set them here as: 1) mice & keyboards don't use zsparam,
    156  * and 2) the console stuff uses these defaults before device
    157  * attach.
    158  */
    159 
    160 static u_char zs_init_reg[16] = {
    161 	0,	/* 0: CMD (reset, etc.) */
    162 	ZSWR1_RIE | ZSWR1_TIE | ZSWR1_SIE,
    163 	0x18 + ZSHARD_PRI,	/* IVECT */
    164 	ZSWR3_RX_8 | ZSWR3_RX_ENABLE,
    165 	ZSWR4_CLK_X16 | ZSWR4_ONESB | ZSWR4_EVENP,
    166 	ZSWR5_TX_8 | ZSWR5_TX_ENABLE,
    167 	0,	/* 6: TXSYNC/SYNCLO */
    168 	0,	/* 7: RXSYNC/SYNCHI */
    169 	0,	/* 8: alias for data port */
    170 	ZSWR9_MASTER_IE,
    171 	0,	/*10: Misc. TX/RX control bits */
    172 	ZSWR11_TXCLK_BAUD | ZSWR11_RXCLK_BAUD,
    173 	14,	/*12: BAUDLO (default=9600) */
    174 	0,	/*13: BAUDHI (default=9600) */
    175 	ZSWR14_BAUD_ENA,
    176 	ZSWR15_BREAK_IE | ZSWR15_DCD_IE | ZSWR15_CTS_IE,
    177 };
    178 
    179 
    180 /****************************************************************
    181  * Autoconfig
    182  ****************************************************************/
    183 
    184 /* Definition of the driver for autoconfig. */
    185 static int	zsc_match __P((struct device *, void *, void *));
    186 static void	zsc_attach __P((struct device *, struct device *, void *));
    187 static int	zsc_print __P((void *aux, const char *name));
    188 
    189 struct cfattach zsc_ca = {
    190 	sizeof(struct zsc_softc), zsc_match, zsc_attach
    191 };
    192 
    193 struct cfdriver zsc_cd = {
    194 	NULL, "zsc", DV_DULL
    195 };
    196 
    197 int	zshard __P((void *));
    198 int	zssoft __P((void *));
    199 
    200 
    201 /*
    202  * Is the zs chip present?
    203  */
    204 static int
    205 zsc_match(parent, vcf, aux)
    206 	struct device *parent;
    207 	void *vcf;
    208 	void *aux;
    209 {
    210 	return 1;
    211 }
    212 
    213 static int
    214 zsc_print(aux, name)
    215 	void *aux;
    216 	const char *name;
    217 {
    218 	struct zsc_attach_args *args = aux;
    219 
    220 	if (name != NULL)
    221 		printf("%s: ", name);
    222 
    223 	if (args->channel != -1)
    224 		printf(" channel %d", args->channel);
    225 
    226 	return UNCONF;
    227 }
    228 
    229 /*
    230  * Attach a found zs.
    231  *
    232  * Match slave number to zs unit number, so that misconfiguration will
    233  * not set up the keyboard as ttya, etc.
    234  */
    235 static void
    236 zsc_attach(parent, self, aux)
    237 	struct device *parent;
    238 	struct device *self;
    239 	void *aux;
    240 {
    241 	struct zsc_softc *zsc = (void *) self;
    242 	struct zsc_attach_args zsc_args;
    243 	volatile struct zschan *zc;
    244 	struct zs_chanstate *cs;
    245 	int zsc_unit, channel;
    246 	int reset, s, chip;
    247 
    248 	if (!zsinited) zs_init();
    249 	zsinited = 2;
    250 
    251 	zsc_unit = zsc->zsc_dev.dv_unit;
    252 
    253 	/* Make sure everything's inited ok. */
    254 	if (zsaddr[zsc_unit] == NULL)
    255 		panic("zs_attach: zs%d not mapped\n", zsc_unit);
    256 
    257 	/*
    258 	 * Initialize software state for each channel.
    259 	 */
    260 	for (channel = 0; channel < 2; channel++) {
    261 		cs = &zsc->zsc_cs[channel];
    262 
    263 		zc = zs_get_chan_addr(zsc_unit, channel);
    264 		cs->cs_reg_csr  = &zc->zc_csr;
    265 		cs->cs_reg_data = &zc->zc_data;
    266 
    267 		cs->cs_channel = channel;
    268 		cs->cs_private = NULL;
    269 		cs->cs_ops = &zsops_null;
    270 
    271 		/* Define BAUD rate clock for the MI code. */
    272 		cs->cs_pclk_div16 = mac68k_machine.sccClkConst*2;
    273 		cs->cs_csource = 0;
    274 		cs->cs_psource = 0;
    275 
    276 		cs->cs_defspeed = zs_defspeed[zsc_unit][channel];
    277 
    278 		bcopy(zs_init_reg, cs->cs_creg, 16);
    279 		bcopy(zs_init_reg, cs->cs_preg, 16);
    280 
    281 		/*
    282 		 * Clear the master interrupt enable.
    283 		 * The INTENA is common to both channels,
    284 		 * so just do it on the A channel.
    285 		 */
    286 		if (channel == 0) {
    287 			zs_write_reg(cs, 9, 0);
    288 
    289 			chip = 0; /* We'll turn chip checking on post 1.2 */
    290 			printf(" chip type %d \n",chip);
    291 		}
    292 		cs->cs_chip = chip;
    293 
    294 		/*
    295 		 * Look for a child driver for this channel.
    296 		 * The child attach will setup the hardware.
    297 		 */
    298 		zsc_args.channel = channel;
    299 		zsc_args.hwflags = zs_hwflags[zsc_unit][channel];
    300 		if (!config_found(self, (void *) &zsc_args, zsc_print)) {
    301 			/* No sub-driver.  Just reset it. */
    302 			reset = (channel == 0) ?
    303 				ZSWR9_A_RESET : ZSWR9_B_RESET;
    304 			s = splzs();
    305 			zs_write_reg(cs,  9, reset);
    306 			splx(s);
    307 		}
    308 	}
    309 
    310 	/*
    311 	 * Set the master interrupt enable and interrupt vector.
    312 	 * (common to both channels, do it on A)
    313 	 */
    314 	cs = &zsc->zsc_cs[0];
    315 	s = splzs();
    316 	/* interrupt vector */
    317 	zs_write_reg(cs, 2, zs_init_reg[2]);
    318 	/* master interrupt control (enable) */
    319 	zs_write_reg(cs, 9, zs_init_reg[9]);
    320 	splx(s);
    321 }
    322 
    323 void
    324 zstty_mdattach(zsc, zst, cs, tp)
    325 	struct zsc_softc *zsc;
    326 	struct zstty_softc *zst;
    327 	struct zs_chanstate *cs;
    328 	struct tty *tp;
    329 {
    330 	int theflags;
    331 
    332 	zst->zst_resetdef = 0;
    333 	cs->cs_clock_count = 3; /* internal + externals */
    334 	cs->cs_cclk_flag = 0;  /* Not doing anything fancy by default */
    335 	cs->cs_pclk_flag = 0;
    336 	cs->cs_clocks[0].clk = mac68k_machine.sccClkConst*32;
    337 	cs->cs_clocks[0].flags = ZSC_RTXBRG; /* allowing divide by 16 will
    338 					melt the driver! */
    339 
    340 	cs->cs_clocks[1].flags = ZSC_RTXBRG | ZSC_RTXDIV | ZSC_VARIABLE | ZSC_EXTERN;
    341 	cs->cs_clocks[2].flags = ZSC_TRXDIV | ZSC_VARIABLE;
    342 	if (zst->zst_dev.dv_unit == 0) {
    343 		theflags = mac68k_machine.modem_flags;
    344 		cs->cs_clocks[1].clk = mac68k_machine.modem_dcd_clk;
    345 		cs->cs_clocks[2].clk = mac68k_machine.modem_cts_clk;
    346 	} else if (zst->zst_dev.dv_unit == 1) {
    347 		theflags = mac68k_machine.print_flags;
    348 		cs->cs_clocks[1].flags = ZSC_VARIABLE;
    349 		/*
    350 		 * Yes, we aren't defining ANY clock source enables for the
    351 		 * printer's DCD clock in. The hardware won't let us
    352 		 * use it. But a clock will freak out the chip, so we
    353 		 * let you set it, telling us to bar interrupts on the line.
    354 		 */
    355 		cs->cs_clocks[1].clk = mac68k_machine.print_dcd_clk;
    356 		cs->cs_clocks[2].clk = mac68k_machine.print_cts_clk;
    357 	}
    358 
    359 	if (cs->cs_clocks[1].clk)
    360 		zst->zst_hwflags |= ZS_HWFLAG_IGDCD;
    361 	if (cs->cs_clocks[2].clk)
    362 		zst->zst_hwflags |= ZS_HWFLAG_IGCTS;
    363 
    364 	if (theflags & ZSMAC_RAW) {
    365 		zst->zst_cflag = ZSTTY_RAW_CFLAG;
    366 		zst->zst_iflag = ZSTTY_RAW_IFLAG;
    367 		zst->zst_lflag = ZSTTY_RAW_LFLAG;
    368 		zst->zst_oflag = ZSTTY_RAW_OFLAG;
    369 		printf(" (raw defaults)");
    370 	}
    371 	if (theflags & ZSMAC_LOCALTALK) {
    372 		printf(" shielding from LocalTalk");
    373 		zst->zst_ospeed = tp->t_ospeed = 1;
    374 		zst->zst_ispeed = tp->t_ispeed = 1;
    375 		cs->cs_defspeed = 1;
    376 		cs->cs_creg[ZSRR_BAUDLO] = cs->cs_preg[ZSRR_BAUDLO] = 0xff;
    377 		cs->cs_creg[ZSRR_BAUDHI] = cs->cs_preg[ZSRR_BAUDHI] = 0xff;
    378 		zs_write_reg(cs, ZSRR_BAUDLO, 0xff);
    379 		zs_write_reg(cs, ZSRR_BAUDHI, 0xff);
    380 		/*
    381 		 * If we might have LocalTalk, then make sure we have the
    382 		 * Baud rate low-enough to not do any damage.
    383 		 */
    384 	}
    385 
    386 	/* For the mac, we have rtscts = check CTS for output control, no
    387 	 * input control. mdmbuf means check DCD for output, and use DTR
    388 	 * for input control. mdmbuf & rtscts means use CTS for output
    389 	 * control, and DTR for input control. */
    390 
    391 	zst->zst_hwimasks[1] = 0;
    392 	zst->zst_hwimasks[2] = ZSWR5_DTR;
    393 	zst->zst_hwimasks[3] = ZSWR5_DTR;
    394 }
    395 
    396 int
    397 zsmdioctl(tp, com, data, flag, p)
    398 	struct tty *tp;
    399 	u_long com;
    400 	caddr_t data;
    401 	int flag;
    402 	struct proc *p;
    403 {
    404 	return (-1);
    405 }
    406 
    407 void
    408 zsmd_setclock(cs)
    409 	struct zs_chanstate *cs;
    410 {
    411 	if (cs->cs_channel != 0)
    412 		return;
    413 	/*
    414 	 * If the new clock has the external bit set, then select the
    415 	 * external source.
    416 	 */
    417 	via_set_modem((cs->cs_pclk_flag & ZSC_EXTERN) ? 1 : 0);
    418 }
    419 
    420 int
    421 zshard(arg)
    422 	void *arg;
    423 {
    424 	struct zsc_softc *zsc;
    425 	int unit, rval;
    426 #ifdef ZSMACDEBUG
    427 	itecnputc(mac68k_zsdev, 'Z');
    428 #endif
    429 
    430 	rval = 0;
    431 	unit = zsc_cd.cd_ndevs;
    432 	while (--unit >= 0) {
    433 		zsc = zsc_cd.cd_devs[unit];
    434 		if (zsc != NULL) {
    435 			rval |= zsc_intr_hard(zsc);
    436 		}
    437 	}
    438 #ifdef ZSMACDEBUG
    439 	itecnputc(mac68k_zsdev, '\n');
    440 #endif
    441 	return (rval);
    442 }
    443 
    444 int zssoftpending;
    445 
    446 void
    447 zsc_req_softint(zsc)
    448 	struct zsc_softc *zsc;
    449 {
    450 	if (zssoftpending == 0) {
    451 		/* We are at splzs here, so no need to lock. */
    452 		zssoftpending = ZSSOFT_PRI;
    453 	/*	isr_soft_request(ZSSOFT_PRI); */
    454 		setsoftserial();
    455 	}
    456 }
    457 
    458 int
    459 zssoft(arg)
    460 	void *arg;
    461 {
    462 	struct zsc_softc *zsc;
    463 	int unit;
    464 
    465 	/* This is not the only ISR on this IPL. */
    466 	if (zssoftpending == 0)
    467 		return (0);
    468 
    469 	/*
    470 	 * The soft intr. bit will be set by zshard only if
    471 	 * the variable zssoftpending is zero.  The order of
    472 	 * these next two statements prevents our clearing
    473 	 * the soft intr bit just after zshard has set it.
    474 	 */
    475 /*	isr_soft_clear(ZSSOFT_PRI); */
    476 	zssoftpending = 0;
    477 
    478 	/* Do ttya/ttyb first, because they go faster. */
    479 	unit = zsc_cd.cd_ndevs;
    480 	while (--unit >= 0) {
    481 		zsc = zsc_cd.cd_devs[unit];
    482 		if (zsc != NULL) {
    483 			(void) zsc_intr_soft(zsc);
    484 		}
    485 	}
    486 	return (1);
    487 }
    488 
    489 
    490 /*
    491  * Read or write the chip with suitable delays.
    492  */
    493 #define	ZS_DELAY()
    494 /*
    495  * MacII hardware has the delay built in. No need for extra delay. :-)
    496  */
    497 
    498 u_char
    499 zs_read_reg(cs, reg)
    500 	struct zs_chanstate *cs;
    501 	u_char reg;
    502 {
    503 	u_char val;
    504 
    505 	*cs->cs_reg_csr = reg;
    506 	ZS_DELAY();
    507 	val = *cs->cs_reg_csr;
    508 	ZS_DELAY();
    509 	return val;
    510 }
    511 
    512 void
    513 zs_write_reg(cs, reg, val)
    514 	struct zs_chanstate *cs;
    515 	u_char reg, val;
    516 {
    517 	*cs->cs_reg_csr = reg;
    518 	ZS_DELAY();
    519 	*cs->cs_reg_csr = val;
    520 	ZS_DELAY();
    521 }
    522 
    523 u_char zs_read_csr(cs)
    524 	struct zs_chanstate *cs;
    525 {
    526 	register u_char v;
    527 
    528 	v = (*cs->cs_reg_csr) ^ ZSRR0_CTS;
    529 	/* make up for the fact CTS is wired backwards */
    530 	ZS_DELAY();
    531 	return v;
    532 }
    533 
    534 u_char zs_read_data(cs)
    535 	struct zs_chanstate *cs;
    536 {
    537 	register u_char v;
    538 
    539 	v = *cs->cs_reg_data;
    540 	ZS_DELAY();
    541 	return v;
    542 }
    543 
    544 void  zs_write_csr(cs, val)
    545 	struct zs_chanstate *cs;
    546 	u_char val;
    547 {
    548 	*cs->cs_reg_csr = val;
    549 	ZS_DELAY();
    550 }
    551 
    552 void  zs_write_data(cs, val)
    553 	struct zs_chanstate *cs;
    554 	u_char val;
    555 {
    556 	*cs->cs_reg_data = val;
    557 	ZS_DELAY();
    558 }
    559 
    560 /****************************************************************
    561  * Console support functions (Originally Sun3 specific!)
    562  * Now works w/ just mac68k port!
    563  ****************************************************************/
    564 
    565 #define zscnpollc	nullcnpollc
    566 cons_decl(zs);
    567 
    568 static void	zs_putc __P((register volatile struct zschan *, int));
    569 static int	zs_getc __P((register volatile struct zschan *));
    570 static void	zscnsetup __P((void));
    571 extern int	zsopen __P(( dev_t dev, int flags, int mode, struct proc *p));
    572 
    573 /*
    574  * Console functions.
    575  */
    576 
    577 /*
    578  * This code modled after the zs_setparam routine in zskgdb
    579  * It sets the console unit to a known state so we can output
    580  * correctly.
    581  */
    582 static void
    583 zscnsetup()
    584 {
    585 	struct zs_chanstate cs;
    586 	struct zschan *zc;
    587 	int    tconst, s;
    588 
    589 	/* Setup temporary chanstate. */
    590 	bzero((caddr_t)&cs, sizeof(cs));
    591 	zc = zs_conschan;
    592 	cs.cs_reg_csr  = &zc->zc_csr;
    593 	cs.cs_reg_data = &zc->zc_data;
    594 	cs.cs_channel = zs_consunit;
    595 
    596 	bcopy(zs_init_reg, cs.cs_preg, 16);
    597 	tconst = BPS_TO_TCONST(mac68k_machine.sccClkConst*2, zs_defspeed[0][zs_consunit]);
    598         cs.cs_preg[5] |= ZSWR5_DTR | ZSWR5_RTS;
    599 	cs.cs_preg[1] = 0; /* don't enable interrupts */
    600         cs.cs_preg[12] = tconst;
    601         cs.cs_preg[13] = tconst >> 8;
    602 
    603         s = splhigh();
    604         zs_loadchannelregs(&cs);
    605         splx(s);
    606 }
    607 
    608 /*
    609  * zscnprobe is the routine which gets called as the kernel is trying to
    610  * figure out where the console should be. Each io driver which might
    611  * be the console (as defined in mac68k/conf.c) gets probed. The probe
    612  * fills in the consdev structure. Important parts are the device #,
    613  * and the console priority. Values are CN_DEAD (don't touch me),
    614  * CN_NORMAL (I'm here, but elsewhere might be better), CN_INTERNAL
    615  * (the video, better than CN_NORMAL), and CN_REMOTE (pick me!)
    616  *
    617  * As the mac's a bit different, we do extra work here. We mainly check
    618  * to see if we have serial echo going on, and if the tty's are supposed
    619  * to default to raw or not.
    620  */
    621 void
    622 zscnprobe(struct consdev * cp)
    623 {
    624         extern u_long   IOBase;
    625         int     maj, unit;
    626 
    627         for (maj = 0; maj < nchrdev; maj++) {
    628                 if (cdevsw[maj].d_open == zsopen) {
    629                         break;
    630                 }
    631         }
    632         if (maj == nchrdev) {
    633                 /* no console entry for us */
    634                 if (mac68k_machine.serial_boot_echo) {
    635                         mac68k_set_io_offsets(IOBase);
    636                 	zs_conschan = (struct zschan *) -1; /* dummy flag for zs_init() */
    637 			zs_consunit = 1;
    638 			zs_hwflags[0][zs_consunit] = ZS_HWFLAG_CONSOLE;
    639 			zs_init();
    640                         zscnsetup();
    641                 }
    642                 return;
    643         }
    644 
    645         cp->cn_pri = CN_NORMAL;                 /* Lower than CN_INTERNAL */
    646         if (mac68k_machine.serial_console != 0) {
    647                 cp->cn_pri = CN_REMOTE;         /* Higher than CN_INTERNAL */
    648                 mac68k_machine.serial_boot_echo =0;
    649         }
    650 
    651         unit = (mac68k_machine.serial_console == 1) ? 0 : 1;
    652 	zs_consunit = unit;
    653 
    654         mac68k_zsdev = cp->cn_dev = makedev(maj, unit);
    655 
    656         if (mac68k_machine.serial_boot_echo) {
    657                 /*
    658                  * at this point, we know that we don't have a serial
    659                  * console, but are doing echo
    660                  */
    661                 mac68k_set_io_offsets(IOBase);
    662                 zs_conschan = (struct zschan *) -1; /* dummy flag for zs_init() */
    663 		zs_consunit = 1;
    664 		zs_hwflags[0][zs_consunit] = ZS_HWFLAG_CONSOLE;
    665 		zs_init();
    666                 zscnsetup();
    667         }
    668         return;
    669 }
    670 
    671 void
    672 zscninit(struct consdev * cp)
    673 {
    674         extern u_long   IOBase;
    675 	int chan = minor(cp->cn_dev & 1);
    676 
    677         mac68k_set_io_offsets(IOBase);
    678 	zs_conschan = (struct zschan *) -1;
    679 	zs_consunit = chan;
    680 	zs_hwflags[0][zs_consunit] = ZS_HWFLAG_CONSOLE;
    681 #ifdef ZS_CONSOLE_ABORT
    682 	zs_hwflags[0][zs_consunit] |= ZS_HWFLAG_CONABRT;
    683 #endif
    684 	zs_init();
    685         /*
    686 	 * zsinit will set up the addresses of the scc. It will also, if
    687 	 * zs_conschan != 0, calculate the new address of the conschan for
    688 	 * unit zs_consunit. So zs_init implicitly sets zs_conschan to the right
    689 	 * number. :-)
    690          */
    691         zscnsetup();
    692         printf("\nNetBSD/mac68k console\n");
    693 }
    694 
    695 
    696 /*
    697  * Polled input char.
    698  */
    699 static int
    700 zs_getc(zc)
    701 	register volatile struct zschan *zc;
    702 {
    703 	register int s, c, rr0;
    704 
    705 	s = splhigh();
    706 	/* Wait for a character to arrive. */
    707 	do {
    708 		rr0 = zc->zc_csr;
    709 		ZS_DELAY();
    710 	} while ((rr0 & ZSRR0_RX_READY) == 0);
    711 
    712 	c = zc->zc_data;
    713 	ZS_DELAY();
    714 	splx(s);
    715 
    716 	/*
    717 	 * This is used by the kd driver to read scan codes,
    718 	 * so don't translate '\r' ==> '\n' here...
    719 	 */
    720 	return (c);
    721 }
    722 
    723 /*
    724  * Polled output char.
    725  */
    726 static void
    727 zs_putc(zc, c)
    728 	register volatile struct zschan *zc;
    729 	int c;
    730 {
    731 	register int s, rr0;
    732 	register long wait = 0;
    733 
    734 	s = splhigh();
    735 	/* Wait for transmitter to become ready. */
    736 	do {
    737 		rr0 = zc->zc_csr;
    738 		ZS_DELAY();
    739 	} while (((rr0 & ZSRR0_TX_READY) == 0) && (wait++ < 1000000));
    740 
    741 	if ((rr0 & ZSRR0_TX_READY) != 0) {
    742 		zc->zc_data = c;
    743 		ZS_DELAY();
    744 	}
    745 	splx(s);
    746 }
    747 
    748 
    749 /*
    750  * Polled console input putchar.
    751  */
    752 int
    753 zscngetc(dev)
    754 	dev_t dev;
    755 {
    756 	register volatile struct zschan *zc = zs_conschan;
    757 	register int c;
    758 
    759 	c = zs_getc(zc);
    760 	return (c);
    761 }
    762 
    763 /*
    764  * Polled console output putchar.
    765  */
    766 void
    767 zscnputc(dev, c)
    768 	dev_t dev;
    769 	int c;
    770 {
    771 	register volatile struct zschan *zc = zs_conschan;
    772 
    773 	zs_putc(zc, c);
    774 }
    775 
    776 
    777 
    778 /*
    779  * Handle user request to enter kernel debugger.
    780  */
    781 void
    782 zs_abort(zst)
    783 	register struct zstty_softc *zst;
    784 {
    785 	register volatile struct zschan *zc = zs_conschan;
    786 	int rr0;
    787 	register long wait = 0;
    788 
    789 	if ((zst->zst_hwflags & ZS_HWFLAG_CONABRT) == 0)
    790 		return;
    791 
    792 	/* Wait for end of break to avoid PROM abort. */
    793 	/* XXX - Limit the wait? */
    794 	do {
    795 		rr0 = zc->zc_csr;
    796 		ZS_DELAY();
    797 	} while ((rr0 & ZSRR0_BREAK) && (wait++ < ZSABORT_DELAY));
    798 
    799 	if (wait > ZSABORT_DELAY) {
    800 		if (zst != NULL) zst->zst_hwflags &= ~ZS_HWFLAG_CONABRT;
    801 	/* If we time out, turn off the abort ability! */
    802 	}
    803 
    804 	/* XXX - Always available, but may be the PROM monitor. */
    805 	Debugger();
    806 }
    807