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zs.c revision 1.1
      1 /*	$NetBSD: zs.c,v 1.1 1996/05/18 18:54:37 briggs 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 
     60 /*
     61  * XXX: Hard code this to make console init easier...
     62  */
     63 #define	NZSC	1		/* XXX */
     64 
     65 /*
     66  * Define interrupt levels.
     67  */
     68 #define ZSHARD_PRI	6	/* Wired on the CPU board... */
     69 #define ZSSOFT_PRI	3	/* Want tty pri (4) but this is OK. */
     70 
     71 /* The layout of this is hardware-dependent (padding, order). */
     72 struct zschan {
     73 	volatile u_char	zc_csr;		/* ctrl,status, and indirect access */
     74 	u_char		zc_xxx0;
     75 	u_char		zc_xxx1;
     76 	u_char		zc_xxx2;
     77 	volatile u_char	zc_data;	/* data */
     78 	u_char		zc_xxx3;
     79 	u_char		zc_xxx4;
     80 	u_char		zc_xxx5;
     81 };
     82 /*
     83  * The zsdevice structure is not used on the mac68k port as the
     84  * chip is wired up weird. Channel B & A are interspursed with
     85  * the data & control bytes
     86 struct zsdevice {
     87 	/! Yes, they are backwards. !/
     88 	struct	zschan zs_chan_b;
     89 	struct	zschan zs_chan_a;
     90 };
     91 */
     92 
     93 /* Saved PROM mappings */
     94 static char *zsaddr[NZSC];	/* See zs_init() */
     95 /* Flags from cninit() */
     96 static int zs_hwflags[NZSC][2];
     97 /* Default speed for each channel */
     98 static int zs_defspeed[NZSC][2] = {
     99 	{ 9600, 	/* tty00 */
    100 	  9600 },	/* tty01 */
    101 };
    102 /* console stuff */
    103 void *zs_conschan = 0;
    104 int   zs_consunit;
    105 /* device that the console is attached to--if serial. */
    106 dev_t	mac68k_zsdev;
    107 /* Mac stuff, some vestages of old mac serial driver here */
    108 volatile unsigned char *sccA = 0;
    109 
    110 static struct zschan	*zs_get_chan_addr __P((int zsc_unit, int channel));
    111 void			zs_init __P((void));
    112 
    113 static struct zschan *
    114 zs_get_chan_addr(zsc_unit, channel)
    115 	int zsc_unit, channel;
    116 {
    117 	char *addr;
    118 	struct zschan *zc;
    119 
    120 	if (zsc_unit >= NZSC)
    121 		return NULL;
    122 	addr = zsaddr[zsc_unit];
    123 	if (addr == NULL)
    124 		return NULL;
    125 	if (channel == 0) {
    126 		zc = (struct zschan *)(addr +2);
    127 		/* handle the fact the ports are intertwined. */
    128 	} else {
    129 		zc = (struct zschan *)(addr);
    130 	}
    131 	return (zc);
    132 }
    133 
    134 
    135 /* Find PROM mappings (for console support). */
    136 static int zsinited = 0; /* 0 = not, 1 = inited, not attached, 2= attached */
    137 
    138 void
    139 zs_init()
    140 {
    141 	if ((zsinited == 2)&&(zsaddr[0] != (char *) sccA))
    142 		panic("Moved zs0 address after attached!");
    143 	zsaddr[0] = (char *) sccA;
    144 	zsinited = 1;
    145 	if (zs_conschan != 0){ /* we might have moved io under the console */
    146 		zs_conschan = zs_get_chan_addr(0, zs_consunit);
    147 		/* so recalc the console port */
    148 	}
    149 }
    150 
    151 
    152 /*
    153  * Even though zsparam will set up the clock multiples, etc., we
    154  * still set them here as: 1) mice & keyboards don't use zsparam,
    155  * and 2) the console stuff uses these defaults before device
    156  * attach.
    157  */
    158 
    159 static u_char zs_init_reg[16] = {
    160 	0,	/* 0: CMD (reset, etc.) */
    161 	ZSWR1_RIE | ZSWR1_TIE | ZSWR1_SIE,
    162 	0x18 + ZSHARD_PRI,	/* IVECT */
    163 	ZSWR3_RX_8 | ZSWR3_RX_ENABLE,
    164 	ZSWR4_CLK_X16 | ZSWR4_ONESB | ZSWR4_EVENP,
    165 	ZSWR5_TX_8 | ZSWR5_TX_ENABLE,
    166 	0,	/* 6: TXSYNC/SYNCLO */
    167 	0,	/* 7: RXSYNC/SYNCHI */
    168 	0,	/* 8: alias for data port */
    169 	ZSWR9_MASTER_IE,
    170 	0,	/*10: Misc. TX/RX control bits */
    171 	ZSWR11_TXCLK_BAUD | ZSWR11_RXCLK_BAUD,
    172 	14,	/*12: BAUDLO (default=9600) */
    173 	0,	/*13: BAUDHI (default=9600) */
    174 	ZSWR14_BAUD_ENA,
    175 	ZSWR15_BREAK_IE | ZSWR15_DCD_IE | ZSWR15_CTS_IE,
    176 };
    177 
    178 
    179 /****************************************************************
    180  * Autoconfig
    181  ****************************************************************/
    182 
    183 /* Definition of the driver for autoconfig. */
    184 static int	zsc_match __P((struct device *, void *, void *));
    185 static void	zsc_attach __P((struct device *, struct device *, void *));
    186 static int	zsc_print __P((void *aux, char *name));
    187 
    188 struct cfattach zsc_ca = {
    189 	sizeof(struct zsc_softc), zsc_match, zsc_attach
    190 };
    191 
    192 struct cfdriver zsc_cd = {
    193 	NULL, "zsc", DV_DULL
    194 };
    195 
    196 int	zshard __P((void *));
    197 int	zssoft __P((void *));
    198 
    199 
    200 /*
    201  * Is the zs chip present?
    202  */
    203 static int
    204 zsc_match(parent, vcf, aux)
    205 	struct device *parent;
    206 	void *vcf;
    207 	void *aux;
    208 {
    209 	return 1;
    210 }
    211 
    212 static int
    213 zsc_print(aux, name)
    214 	void *aux;
    215 	char *name;
    216 {
    217 	struct zsc_attach_args *args = aux;
    218 
    219 	if (name != NULL)
    220 		printf("%s: ", name);
    221 
    222 	if (args->channel != -1)
    223 		printf(" channel %d", args->channel);
    224 
    225 	return UNCONF;
    226 }
    227 
    228 /*
    229  * Attach a found zs.
    230  *
    231  * Match slave number to zs unit number, so that misconfiguration will
    232  * not set up the keyboard as ttya, etc.
    233  */
    234 static void
    235 zsc_attach(parent, self, aux)
    236 	struct device *parent;
    237 	struct device *self;
    238 	void *aux;
    239 {
    240 	struct zsc_softc *zsc = (void *) self;
    241 	struct zsc_attach_args zsc_args;
    242 	volatile struct zschan *zc;
    243 	struct zs_chanstate *cs;
    244 	int zsc_unit, channel;
    245 	int reset, s, chip;
    246 
    247 	if (!zsinited) zs_init();
    248 	zsinited = 2;
    249 
    250 	zsc_unit = zsc->zsc_dev.dv_unit;
    251 
    252 	/* Make sure everything's inited ok. */
    253 	if (zsaddr[zsc_unit] == NULL)
    254 		panic("zs_attach: zs%d not mapped\n", zsc_unit);
    255 
    256 	/*
    257 	 * Initialize software state for each channel.
    258 	 */
    259 	for (channel = 0; channel < 2; channel++) {
    260 		cs = &zsc->zsc_cs[channel];
    261 
    262 		zc = zs_get_chan_addr(zsc_unit, channel);
    263 		cs->cs_reg_csr  = &zc->zc_csr;
    264 		cs->cs_reg_data = &zc->zc_data;
    265 
    266 		cs->cs_channel = channel;
    267 		cs->cs_private = NULL;
    268 		cs->cs_ops = &zsops_null;
    269 
    270 		/* Define BAUD rate clock for the MI code. */
    271 		cs->cs_pclk_div16 = mac68k_machine.sccClkConst*2;
    272 		cs->cs_csource = 0;
    273 		cs->cs_psource = 0;
    274 
    275 		cs->cs_defspeed = zs_defspeed[zsc_unit][channel];
    276 
    277 		bcopy(zs_init_reg, cs->cs_creg, 16);
    278 		bcopy(zs_init_reg, cs->cs_preg, 16);
    279 
    280 		/*
    281 		 * Clear the master interrupt enable.
    282 		 * The INTENA is common to both channels,
    283 		 * so just do it on the A channel.
    284 		 */
    285 		if (channel == 0) {
    286 			zs_write_reg(cs, 9, 0);
    287 
    288 			chip = zs_checkchip(cs);
    289 			printf(" chip type %d \n",chip);
    290 		}
    291 		cs->cs_chip = chip;
    292 
    293 		/*
    294 		 * Look for a child driver for this channel.
    295 		 * The child attach will setup the hardware.
    296 		 */
    297 		zsc_args.channel = channel;
    298 		zsc_args.hwflags = zs_hwflags[zsc_unit][channel];
    299 		if (!config_found(self, (void *) &zsc_args, zsc_print)) {
    300 			/* No sub-driver.  Just reset it. */
    301 			reset = (channel == 0) ?
    302 				ZSWR9_A_RESET : ZSWR9_B_RESET;
    303 			s = splzs();
    304 			zs_write_reg(cs,  9, reset);
    305 			splx(s);
    306 		}
    307 	}
    308 
    309 	/*
    310 	 * Set the master interrupt enable and interrupt vector.
    311 	 * (common to both channels, do it on A)
    312 	 */
    313 	cs = &zsc->zsc_cs[0];
    314 	s = splzs();
    315 	/* interrupt vector */
    316 	zs_write_reg(cs, 2, zs_init_reg[2]);
    317 	/* master interrupt control (enable) */
    318 	zs_write_reg(cs, 9, zs_init_reg[9]);
    319 	splx(s);
    320 }
    321 
    322 void
    323 zstty_mdattach(zsc, zst, cs, tp)
    324 	struct zsc_softc *zsc;
    325 	struct zstty_softc *zst;
    326 	struct zs_chanstate *cs;
    327 	struct tty *tp;
    328 {
    329 	zst->zst_resetdef = 0;
    330 	cs->cs_clock_count = 3; /* internal + externals */
    331 	cs->cs_cclk_flag = 0;  /* Not doing anything fancy by default */
    332 	cs->cs_pclk_flag = 0;
    333 	cs->cs_clocks[0].clk = mac68k_machine.sccClkConst*32;
    334 	cs->cs_clocks[0].flags = ZSC_RTXBRG; /* allowing divide by 16 will
    335 					melt the driver! */
    336 	cs->cs_clocks[1].clk = 0;
    337 	cs->cs_clocks[1].flags = ZSC_RTXBRG | ZSC_RTXDIV | ZSC_VARIABLE | ZSC_EXTERN;
    338 	cs->cs_clocks[2].clk = 0;
    339 	cs->cs_clocks[2].flags = ZSC_TRXDIV | ZSC_VARIABLE;
    340 
    341 	/* For the mac, we have rtscts = check CTS for output control, no
    342 	 * input control. mdmbuf means check DCD for output, and use DTR
    343 	 * for input control. mdmbuf & rtscts means use CTS for output
    344 	 * control, and DTR for input control. */
    345 
    346 	zst->zst_hwimasks[1] = 0;
    347 	zst->zst_hwimasks[2] = ZSWR5_DTR;
    348 	zst->zst_hwimasks[3] = ZSWR5_DTR;
    349 }
    350 
    351 int
    352 zsmdioctl(tp, com, data, flag, p)
    353 	struct tty *tp;
    354 	u_long com;
    355 	caddr_t data;
    356 	int flag;
    357 	struct proc *p;
    358 {
    359 	return (-1);
    360 }
    361 
    362 void
    363 zsmd_setclock(cs)
    364 	struct zs_chanstate *cs;
    365 {
    366 	if (cs->cs_pclk_flag & ZSC_EXTERN) {
    367 	/* XXX need to set the via! */
    368 	}
    369 }
    370 
    371 int
    372 zshard(arg)
    373 	void *arg;
    374 {
    375 	struct zsc_softc *zsc;
    376 	int unit, rval;
    377 #ifdef ZSMACDEBUG
    378 	itecnputc(mac68k_zsdev, 'Z');
    379 #endif
    380 
    381 	rval = 0;
    382 	unit = zsc_cd.cd_ndevs;
    383 	while (--unit >= 0) {
    384 		zsc = zsc_cd.cd_devs[unit];
    385 		if (zsc != NULL) {
    386 			rval |= zsc_intr_hard(zsc);
    387 		}
    388 	}
    389 #ifdef ZSMACDEBUG
    390 	itecnputc(mac68k_zsdev, '\n');
    391 #endif
    392 	return (rval);
    393 }
    394 
    395 int zssoftpending;
    396 
    397 void
    398 zsc_req_softint(zsc)
    399 	struct zsc_softc *zsc;
    400 {
    401 	if (zssoftpending == 0) {
    402 		/* We are at splzs here, so no need to lock. */
    403 		zssoftpending = ZSSOFT_PRI;
    404 	/*	isr_soft_request(ZSSOFT_PRI); */
    405 		setsoftserial();
    406 	}
    407 }
    408 
    409 int
    410 zssoft(arg)
    411 	void *arg;
    412 {
    413 	struct zsc_softc *zsc;
    414 	int unit;
    415 
    416 	/* This is not the only ISR on this IPL. */
    417 	if (zssoftpending == 0)
    418 		return (0);
    419 
    420 	/*
    421 	 * The soft intr. bit will be set by zshard only if
    422 	 * the variable zssoftpending is zero.  The order of
    423 	 * these next two statements prevents our clearing
    424 	 * the soft intr bit just after zshard has set it.
    425 	 */
    426 /*	isr_soft_clear(ZSSOFT_PRI); */
    427 	zssoftpending = 0;
    428 
    429 	/* Do ttya/ttyb first, because they go faster. */
    430 	unit = zsc_cd.cd_ndevs;
    431 	while (--unit >= 0) {
    432 		zsc = zsc_cd.cd_devs[unit];
    433 		if (zsc != NULL) {
    434 			(void) zsc_intr_soft(zsc);
    435 		}
    436 	}
    437 	return (1);
    438 }
    439 
    440 
    441 /*
    442  * Read or write the chip with suitable delays.
    443  */
    444 #define	ZS_DELAY()
    445 /*
    446  * MacII hardware has the delay built in. No need for extra delay. :-)
    447  */
    448 
    449 u_char
    450 zs_read_reg(cs, reg)
    451 	struct zs_chanstate *cs;
    452 	u_char reg;
    453 {
    454 	u_char val;
    455 
    456 	*cs->cs_reg_csr = reg;
    457 	ZS_DELAY();
    458 	val = *cs->cs_reg_csr;
    459 	ZS_DELAY();
    460 	return val;
    461 }
    462 
    463 void
    464 zs_write_reg(cs, reg, val)
    465 	struct zs_chanstate *cs;
    466 	u_char reg, val;
    467 {
    468 	*cs->cs_reg_csr = reg;
    469 	ZS_DELAY();
    470 	*cs->cs_reg_csr = val;
    471 	ZS_DELAY();
    472 }
    473 
    474 u_char zs_read_csr(cs)
    475 	struct zs_chanstate *cs;
    476 {
    477 	register u_char v;
    478 
    479 	v = (*cs->cs_reg_csr) ^ ZSRR0_CTS;
    480 	/* make up for the fact CTS is wired backwards */
    481 	ZS_DELAY();
    482 	return v;
    483 }
    484 
    485 u_char zs_read_data(cs)
    486 	struct zs_chanstate *cs;
    487 {
    488 	register u_char v;
    489 
    490 	v = *cs->cs_reg_data;
    491 	ZS_DELAY();
    492 	return v;
    493 }
    494 
    495 void  zs_write_csr(cs, val)
    496 	struct zs_chanstate *cs;
    497 	u_char val;
    498 {
    499 	*cs->cs_reg_csr = val;
    500 	ZS_DELAY();
    501 }
    502 
    503 void  zs_write_data(cs, val)
    504 	struct zs_chanstate *cs;
    505 	u_char val;
    506 {
    507 	*cs->cs_reg_data = val;
    508 	ZS_DELAY();
    509 }
    510 
    511 /****************************************************************
    512  * Console support functions (Originally Sun3 specific!)
    513  * Now works w/ just mac68k port!
    514  ****************************************************************/
    515 
    516 #define zscnpollc	nullcnpollc
    517 cons_decl(zs);
    518 
    519 static void	zs_putc __P((register volatile struct zschan *, int));
    520 static int	zs_getc __P((register volatile struct zschan *));
    521 static void	zscnsetup __P((void));
    522 extern int	zsopen __P(( dev_t dev, int flags, int mode, struct proc *p));
    523 
    524 /*
    525  * Console functions.
    526  */
    527 
    528 /*
    529  * This code modled after the zs_setparam routine in zskgdb
    530  * It sets the console unit to a known state so we can output
    531  * correctly.
    532  */
    533 static void
    534 zscnsetup()
    535 {
    536 	struct zs_chanstate cs;
    537 	struct zschan *zc;
    538 	int    tconst, s;
    539 
    540 	/* Setup temporary chanstate. */
    541 	bzero((caddr_t)&cs, sizeof(cs));
    542 	zc = zs_conschan;
    543 	cs.cs_reg_csr  = &zc->zc_csr;
    544 	cs.cs_reg_data = &zc->zc_data;
    545 	cs.cs_channel = zs_consunit;
    546 
    547 	bcopy(zs_init_reg, cs.cs_preg, 16);
    548 	tconst = BPS_TO_TCONST(mac68k_machine.sccClkConst*2, zs_defspeed[0][zs_consunit]);
    549         cs.cs_preg[5] |= ZSWR5_DTR | ZSWR5_RTS;
    550 	cs.cs_preg[1] = 0; /* don't enable interrupts */
    551         cs.cs_preg[12] = tconst;
    552         cs.cs_preg[13] = tconst >> 8;
    553 
    554         s = splhigh();
    555         zs_loadchannelregs(&cs);
    556         splx(s);
    557 }
    558 
    559 /*
    560  * zscnprobe is the routine which gets called as the kernel is trying to
    561  * figure out where the console should be. Each io driver which might
    562  * be the console (as defined in mac68k/conf.c) gets probed. The probe
    563  * fills in the consdev structure. Important parts are the device #,
    564  * and the console priority. Values are CN_DEAD (don't touch me),
    565  * CN_NORMAL (I'm here, but elsewhere might be better), CN_INTERNAL
    566  * (the video, better than CN_NORMAL), and CN_REMOTE (pick me!)
    567  *
    568  * As the mac's a bit different, we do extra work here. We mainly check
    569  * to see if we have serial echo going on, and if the tty's are supposed
    570  * to default to raw or not.
    571  */
    572 void
    573 zscnprobe(struct consdev * cp)
    574 {
    575         extern u_long   IOBase;
    576         int     maj, unit;
    577 
    578         for (maj = 0; maj < nchrdev; maj++) {
    579                 if (cdevsw[maj].d_open == zsopen) {
    580                         break;
    581                 }
    582         }
    583         if (maj == nchrdev) {
    584                 /* no console entry for us */
    585                 if (mac68k_machine.serial_boot_echo) {
    586                         mac68k_set_io_offsets(IOBase);
    587                 	zs_conschan = (struct zschan *) -1; /* dummy flag for zs_init() */
    588 			zs_consunit = 1;
    589 			zs_hwflags[0][zs_consunit] = ZS_HWFLAG_CONSOLE;
    590 			zs_init();
    591                         zscnsetup();
    592                 }
    593                 return;
    594         }
    595 
    596         cp->cn_pri = CN_NORMAL;                 /* Lower than CN_INTERNAL */
    597         if (mac68k_machine.serial_console != 0) {
    598                 cp->cn_pri = CN_REMOTE;         /* Higher than CN_INTERNAL */
    599                 mac68k_machine.serial_boot_echo =0;
    600         }
    601 
    602         unit = (mac68k_machine.serial_console == 1) ? 0 : 1;
    603 	zs_consunit = unit;
    604 
    605         mac68k_zsdev = cp->cn_dev = makedev(maj, unit);
    606 
    607         if (mac68k_machine.serial_boot_echo) {
    608                 /*
    609                  * at this point, we know that we don't have a serial
    610                  * console, but are doing echo
    611                  */
    612                 mac68k_set_io_offsets(IOBase);
    613                 zs_conschan = (struct zschan *) -1; /* dummy flag for zs_init() */
    614 		zs_consunit = 1;
    615 		zs_hwflags[0][zs_consunit] = ZS_HWFLAG_CONSOLE;
    616 		zs_init();
    617                 zscnsetup();
    618         }
    619         return;
    620 }
    621 
    622 void
    623 zscninit(struct consdev * cp)
    624 {
    625         extern u_long   IOBase;
    626 	int chan = minor(cp->cn_dev & 1);
    627 
    628         mac68k_set_io_offsets(IOBase);
    629 	zs_conschan = (struct zschan *) -1;
    630 	zs_consunit = chan;
    631 	zs_hwflags[0][zs_consunit] = ZS_HWFLAG_CONSOLE | ZS_HWFLAG_CONABRT;
    632 	zs_init();
    633         /*
    634 	 * zsinit will set up the addresses of the scc. It will also, if
    635 	 * zs_conschan != 0, calculate the new address of the conschan for
    636 	 * unit zs_consunit. So zs_init implicitly sets zs_conschan to the right
    637 	 * number. :-)
    638          */
    639         zscnsetup();
    640         printf("Whee! we are the console!\n");
    641 }
    642 
    643 
    644 /*
    645  * Polled input char.
    646  */
    647 static int
    648 zs_getc(zc)
    649 	register volatile struct zschan *zc;
    650 {
    651 	register int s, c, rr0;
    652 
    653 	s = splhigh();
    654 	/* Wait for a character to arrive. */
    655 	do {
    656 		rr0 = zc->zc_csr;
    657 		ZS_DELAY();
    658 	} while ((rr0 & ZSRR0_RX_READY) == 0);
    659 
    660 	c = zc->zc_data;
    661 	ZS_DELAY();
    662 	splx(s);
    663 
    664 	/*
    665 	 * This is used by the kd driver to read scan codes,
    666 	 * so don't translate '\r' ==> '\n' here...
    667 	 */
    668 	return (c);
    669 }
    670 
    671 /*
    672  * Polled output char.
    673  */
    674 static void
    675 zs_putc(zc, c)
    676 	register volatile struct zschan *zc;
    677 	int c;
    678 {
    679 	register int s, rr0;
    680 	register long wait = 0;
    681 
    682 	s = splhigh();
    683 	/* Wait for transmitter to become ready. */
    684 	do {
    685 		rr0 = zc->zc_csr;
    686 		ZS_DELAY();
    687 	} while (((rr0 & ZSRR0_TX_READY) == 0) && (wait++ < 1000000));
    688 
    689 	if ((rr0 & ZSRR0_TX_READY) != 0) {
    690 		zc->zc_data = c;
    691 		ZS_DELAY();
    692 	}
    693 	splx(s);
    694 }
    695 
    696 
    697 /*
    698  * Polled console input putchar.
    699  */
    700 int
    701 zscngetc(dev)
    702 	dev_t dev;
    703 {
    704 	register volatile struct zschan *zc = zs_conschan;
    705 	register int c;
    706 
    707 	c = zs_getc(zc);
    708 	return (c);
    709 }
    710 
    711 /*
    712  * Polled console output putchar.
    713  */
    714 void
    715 zscnputc(dev, c)
    716 	dev_t dev;
    717 	int c;
    718 {
    719 	register volatile struct zschan *zc = zs_conschan;
    720 
    721 	zs_putc(zc, c);
    722 }
    723 
    724 
    725 
    726 /*
    727  * Handle user request to enter kernel debugger.
    728  */
    729 void
    730 zs_abort(zst)
    731 	register struct zstty_softc *zst;
    732 {
    733 	register volatile struct zschan *zc = zs_conschan;
    734 	int rr0;
    735 	register long wait = 0;
    736 
    737 	/* Wait for end of break to avoid PROM abort. */
    738 	/* XXX - Limit the wait? */
    739 	do {
    740 		rr0 = zc->zc_csr;
    741 		ZS_DELAY();
    742 	} while ((rr0 & ZSRR0_BREAK) && (wait++ < ZSABORT_DELAY));
    743 
    744 	if (wait > ZSABORT_DELAY) {
    745 		if (zst != NULL) zst->zst_hwflags &= ~ZS_HWFLAG_CONABRT;
    746 	/* If we time out, turn off the abort ability! */
    747 	}
    748 
    749 	/* XXX - Always available, but may be the PROM monitor. */
    750 	Debugger();
    751 }
    752