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zs.c revision 1.14
      1 /*	$NetBSD: zs.c,v 1.14 2007/03/11 06:34:53 tsutsui Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1996 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Gordon W. Ross.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  * 3. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *        This product includes software developed by the NetBSD
     21  *        Foundation, Inc. and its contributors.
     22  * 4. Neither the name of The NetBSD Foundation nor the names of its
     23  *    contributors may be used to endorse or promote products derived
     24  *    from this software without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     36  * POSSIBILITY OF SUCH DAMAGE.
     37  */
     38 
     39 /*
     40  * Zilog Z8530 Dual UART driver (machine-dependent part)
     41  *
     42  * Runs two serial lines per chip using slave drivers.
     43  * Plain tty/async lines use the zs_async slave.
     44  * Sun keyboard/mouse uses the zs_kbd/zs_ms slaves.
     45  */
     46 
     47 #include <sys/cdefs.h>
     48 __KERNEL_RCSID(0, "$NetBSD: zs.c,v 1.14 2007/03/11 06:34:53 tsutsui Exp $");
     49 
     50 #include "opt_ddb.h"
     51 #include "opt_kgdb.h"
     52 
     53 #include <sys/param.h>
     54 #include <sys/systm.h>
     55 #include <sys/conf.h>
     56 #include <sys/device.h>
     57 #include <sys/file.h>
     58 #include <sys/ioctl.h>
     59 #include <sys/kernel.h>
     60 #include <sys/proc.h>
     61 #include <sys/tty.h>
     62 #include <sys/time.h>
     63 #include <sys/syslog.h>
     64 
     65 #include <machine/autoconf.h>
     66 #include <machine/promlib.h>
     67 #include <machine/cpu.h>
     68 #include <machine/eeprom.h>
     69 #include <machine/psl.h>
     70 #include <machine/z8530var.h>
     71 
     72 #include <dev/cons.h>
     73 #include <dev/ic/z8530reg.h>
     74 #include <dev/sun/kbd_ms_ttyvar.h>
     75 #include <ddb/db_output.h>
     76 
     77 #include <sun2/dev/cons.h>
     78 
     79 #include "kbd.h"	/* NKBD */
     80 #include "ms.h"		/* NMS */
     81 
     82 /*
     83  * Some warts needed by z8530tty.c -
     84  * The default parity REALLY needs to be the same as the PROM uses,
     85  * or you can not see messages done with printf during boot-up...
     86  */
     87 int zs_def_cflag = (CREAD | CS8 | HUPCL);
     88 
     89 /* ZS channel used as the console device (if any) */
     90 void *zs_conschan_get, *zs_conschan_put;
     91 
     92 static u_char zs_init_reg[16] = {
     93 	0,	/* 0: CMD (reset, etc.) */
     94 	0,	/* 1: No interrupts yet. */
     95 #ifdef  ZS_INIT_IVECT
     96 	ZS_INIT_IVECT,	/* 2: IVECT */
     97 #else
     98 	0,	/* 2: IVECT */
     99 #endif
    100 	ZSWR3_RX_8 | ZSWR3_RX_ENABLE,
    101 	ZSWR4_CLK_X16 | ZSWR4_ONESB | ZSWR4_EVENP,
    102 	ZSWR5_TX_8 | ZSWR5_TX_ENABLE,
    103 	0,	/* 6: TXSYNC/SYNCLO */
    104 	0,	/* 7: RXSYNC/SYNCHI */
    105 	0,	/* 8: alias for data port */
    106 #ifdef  ZS_INIT_IVECT
    107 	ZSWR9_MASTER_IE,
    108 #else
    109 	ZSWR9_MASTER_IE | ZSWR9_NO_VECTOR,
    110 #endif
    111 	0,	/*10: Misc. TX/RX control bits */
    112 	ZSWR11_TXCLK_BAUD | ZSWR11_RXCLK_BAUD,
    113 	((PCLK/32)/9600)-2,	/*12: BAUDLO (default=9600) */
    114 	0,			/*13: BAUDHI (default=9600) */
    115 	ZSWR14_BAUD_ENA | ZSWR14_BAUD_FROM_PCLK,
    116 	ZSWR15_BREAK_IE,
    117 };
    118 
    119 /* Console ops */
    120 static int  zscngetc(dev_t);
    121 static void zscnputc(dev_t, int);
    122 static void zscnpollc(dev_t, int);
    123 
    124 struct consdev zs_consdev = {
    125 	NULL,
    126 	NULL,
    127 	zscngetc,
    128 	zscnputc,
    129 	zscnpollc,
    130 	NULL,
    131 };
    132 
    133 
    134 /****************************************************************
    135  * Autoconfig
    136  ****************************************************************/
    137 
    138 static int  zs_print(void *, const char *name);
    139 
    140 extern struct cfdriver zs_cd;
    141 
    142 /* Interrupt handlers. */
    143 int zscheckintr(void *);
    144 static int zshard(void *);
    145 static void zssoft(void *);
    146 
    147 static int zs_get_speed(struct zs_chanstate *);
    148 
    149 /*
    150  * Attach a found zs.
    151  *
    152  * USE ROM PROPERTIES port-a-ignore-cd AND port-b-ignore-cd FOR
    153  * SOFT CARRIER, AND keyboard PROPERTY FOR KEYBOARD/MOUSE?
    154  */
    155 void
    156 zs_attach(struct zsc_softc *zsc, struct zsdevice *zsd, int pri)
    157 {
    158 	struct zsc_attach_args zsc_args;
    159 	struct zs_chanstate *cs;
    160 	int s, channel, softpri = IPL_SOFTSERIAL;
    161 
    162 	if (zsd == NULL) {
    163 		printf("configuration incomplete\n");
    164 		return;
    165 	}
    166 
    167 	/* we should use ipl2si(softpri) but it isn't exported */
    168 	printf(" softpri %d\n", _IPL_SOFT_LEVEL3);
    169 
    170 	/*
    171 	 * Initialize software state for each channel.
    172 	 */
    173 	for (channel = 0; channel < 2; channel++) {
    174 		struct zschan *zc;
    175 		struct device *child;
    176 
    177 		zsc_args.channel = channel;
    178 		cs = &zsc->zsc_cs_store[channel];
    179 		zsc->zsc_cs[channel] = cs;
    180 
    181 		simple_lock_init(&cs->cs_lock);
    182 		cs->cs_channel = channel;
    183 		cs->cs_private = NULL;
    184 		cs->cs_ops = &zsops_null;
    185 		cs->cs_brg_clk = PCLK / 16;
    186 
    187 		zc = (channel == 0) ? &zsd->zs_chan_a : &zsd->zs_chan_b;
    188 
    189 		zsc_args.consdev = NULL;
    190 		zsc_args.hwflags = zs_console_flags(zsc->zsc_promunit,
    191 						    zsc->zsc_node,
    192 						    channel);
    193 
    194 		if (zsc_args.hwflags & ZS_HWFLAG_CONSOLE) {
    195 			zsc_args.hwflags |= ZS_HWFLAG_USE_CONSDEV;
    196 			zsc_args.consdev = &zs_consdev;
    197 		}
    198 
    199 		if ((zsc_args.hwflags & ZS_HWFLAG_CONSOLE_INPUT) != 0) {
    200 			zs_conschan_get = zc;
    201 		}
    202 		if ((zsc_args.hwflags & ZS_HWFLAG_CONSOLE_OUTPUT) != 0) {
    203 			zs_conschan_put = zc;
    204 		}
    205 
    206 		/* Children need to set cn_dev, etc */
    207 		cs->cs_reg_csr  = &zc->zc_csr;
    208 		cs->cs_reg_data = &zc->zc_data;
    209 
    210 		memcpy(cs->cs_creg, zs_init_reg, 16);
    211 		memcpy(cs->cs_preg, zs_init_reg, 16);
    212 
    213 		/* XXX: Consult PROM properties for this?! */
    214 		cs->cs_defspeed = zs_get_speed(cs);
    215 		cs->cs_defcflag = zs_def_cflag;
    216 
    217 		/* Make these correspond to cs_defcflag (-crtscts) */
    218 		cs->cs_rr0_dcd = ZSRR0_DCD;
    219 		cs->cs_rr0_cts = 0;
    220 		cs->cs_wr5_dtr = ZSWR5_DTR | ZSWR5_RTS;
    221 		cs->cs_wr5_rts = 0;
    222 
    223 		/*
    224 		 * Clear the master interrupt enable.
    225 		 * The INTENA is common to both channels,
    226 		 * so just do it on the A channel.
    227 		 */
    228 		if (channel == 0) {
    229 			zs_write_reg(cs, 9, 0);
    230 		}
    231 
    232 		/*
    233 		 * Look for a child driver for this channel.
    234 		 * The child attach will setup the hardware.
    235 		 */
    236 		if (!(child =
    237 		      config_found(&zsc->zsc_dev, (void *)&zsc_args, zs_print))) {
    238 			/* No sub-driver.  Just reset it. */
    239 			u_char reset = (channel == 0) ?
    240 				ZSWR9_A_RESET : ZSWR9_B_RESET;
    241 			s = splzs();
    242 			zs_write_reg(cs,  9, reset);
    243 			splx(s);
    244 		}
    245 #if (NKBD > 0) || (NMS > 0)
    246 		/*
    247 		 * If this was a zstty it has a keyboard
    248 		 * property on it we need to attach the
    249 		 * sunkbd and sunms line disciplines.
    250 		 */
    251 		if (child
    252 		    && device_is_a(child, "zstty")) {
    253 			struct kbd_ms_tty_attach_args kma;
    254 			struct zstty_softc {
    255 				/* The following are the only fields we need here */
    256 				struct	device zst_dev;
    257 				struct  tty *zst_tty;
    258 				struct	zs_chanstate *zst_cs;
    259 			} *zst = (struct zstty_softc *)child;
    260 			struct tty *tp;
    261 
    262 			kma.kmta_tp = tp = zst->zst_tty;
    263 			if (tp != NULL) {
    264 				kma.kmta_dev = tp->t_dev;
    265 				kma.kmta_consdev = zsc_args.consdev;
    266 
    267 				/* Attach 'em if we got 'em. */
    268 				switch(zs_peripheral_type(zsc->zsc_promunit,
    269 						 	  zsc->zsc_node,
    270 						  	  channel)) {
    271 				case ZS_PERIPHERAL_SUNKBD:
    272 #if (NKBD > 0)
    273 					kma.kmta_name = "keyboard";
    274 					config_found(child, (void *)&kma, NULL);
    275 #endif
    276 					break;
    277 				case ZS_PERIPHERAL_SUNMS:
    278 #if (NMS > 0)
    279 					kma.kmta_name = "mouse";
    280 					config_found(child, (void *)&kma, NULL);
    281 #endif
    282 					break;
    283 				default:
    284 					break;
    285 				}
    286 			}
    287 		}
    288 #endif
    289 	}
    290 
    291 	/*
    292 	 * Now safe to install interrupt handlers.
    293 	 */
    294 	bus_intr_establish(zsc->zsc_bustag, pri, IPL_SERIAL, 0, zshard, zsc);
    295 	if (!(zsc->zsc_softintr = softintr_establish(softpri, zssoft, zsc)))
    296 		panic("zsattach: could not establish soft interrupt");
    297 
    298 	evcnt_attach_dynamic(&zsc->zsc_intrcnt, EVCNT_TYPE_INTR, NULL,
    299 	    zsc->zsc_dev.dv_xname, "intr");
    300 
    301 
    302 	/*
    303 	 * Set the master interrupt enable and interrupt vector.
    304 	 * (common to both channels, do it on A)
    305 	 */
    306 	cs = zsc->zsc_cs[0];
    307 	s = splhigh();
    308 	/* interrupt vector */
    309 	zs_write_reg(cs, 2, zs_init_reg[2]);
    310 	/* master interrupt control (enable) */
    311 	zs_write_reg(cs, 9, zs_init_reg[9]);
    312 	splx(s);
    313 
    314 }
    315 
    316 static int
    317 zs_print(void *aux, const char *name)
    318 {
    319 	struct zsc_attach_args *args = aux;
    320 
    321 	if (name != NULL)
    322 		aprint_normal("%s: ", name);
    323 
    324 	if (args->channel != -1)
    325 		aprint_normal(" channel %d", args->channel);
    326 
    327 	return (UNCONF);
    328 }
    329 
    330 static int
    331 zshard(void *arg)
    332 {
    333 	struct zsc_softc *zsc = (struct zsc_softc *)arg;
    334 	int rr3, rval;
    335 
    336 	rval = 0;
    337 	while ((rr3 = zsc_intr_hard(zsc))) {
    338 		/* Count up the interrupts. */
    339 		rval |= rr3;
    340 		zsc->zsc_intrcnt.ev_count++;
    341 	}
    342 	if (((zsc->zsc_cs[0] && zsc->zsc_cs[0]->cs_softreq) ||
    343 	     (zsc->zsc_cs[1] && zsc->zsc_cs[1]->cs_softreq)) &&
    344 	    zsc->zsc_softintr) {
    345 		softintr_schedule(zsc->zsc_softintr);
    346 	}
    347 	return (rval);
    348 }
    349 
    350 int
    351 zscheckintr(void *arg)
    352 {
    353 	struct zsc_softc *zsc;
    354 	int unit, rval;
    355 
    356 	rval = 0;
    357 	for (unit = 0; unit < zs_cd.cd_ndevs; unit++) {
    358 
    359 		zsc = zs_cd.cd_devs[unit];
    360 		if (zsc == NULL)
    361 			continue;
    362 		rval = (zshard((void *)zsc) || rval);
    363 	}
    364 	return (rval);
    365 }
    366 
    367 
    368 /*
    369  * We need this only for TTY_DEBUG purposes.
    370  */
    371 static void
    372 zssoft(void *arg)
    373 {
    374 	struct zsc_softc *zsc = (struct zsc_softc *)arg;
    375 	int s;
    376 
    377 	/* Make sure we call the tty layer at spltty. */
    378 	s = spltty();
    379 	(void)zsc_intr_soft(zsc);
    380 #ifdef TTY_DEBUG
    381 	{
    382 		struct zstty_softc *zst0 = zsc->zsc_cs[0]->cs_private;
    383 		struct zstty_softc *zst1 = zsc->zsc_cs[1]->cs_private;
    384 		if (zst0->zst_overflows || zst1->zst_overflows ) {
    385 			struct trapframe *frame = (struct trapframe *)arg;
    386 
    387 			printf("zs silo overflow from %p\n",
    388 			       (long)frame->tf_pc);
    389 		}
    390 	}
    391 #endif
    392 	splx(s);
    393 }
    394 
    395 
    396 /*
    397  * Compute the current baud rate given a ZS channel.
    398  */
    399 static int
    400 zs_get_speed(struct zs_chanstate *cs)
    401 {
    402 	int tconst;
    403 
    404 	tconst = zs_read_reg(cs, 12);
    405 	tconst |= zs_read_reg(cs, 13) << 8;
    406 	return (TCONST_TO_BPS(cs->cs_brg_clk, tconst));
    407 }
    408 
    409 /*
    410  * MD functions for setting the baud rate and control modes.
    411  */
    412 int
    413 zs_set_speed(struct zs_chanstate *cs, int bps)
    414 {
    415 	int tconst, real_bps;
    416 
    417 	if (bps == 0)
    418 		return (0);
    419 
    420 #ifdef	DIAGNOSTIC
    421 	if (cs->cs_brg_clk == 0)
    422 		panic("zs_set_speed");
    423 #endif
    424 
    425 	tconst = BPS_TO_TCONST(cs->cs_brg_clk, bps);
    426 	if (tconst < 0)
    427 		return (EINVAL);
    428 
    429 	/* Convert back to make sure we can do it. */
    430 	real_bps = TCONST_TO_BPS(cs->cs_brg_clk, tconst);
    431 
    432 	/* XXX - Allow some tolerance here? */
    433 	if (real_bps != bps)
    434 		return (EINVAL);
    435 
    436 	cs->cs_preg[12] = tconst;
    437 	cs->cs_preg[13] = tconst >> 8;
    438 
    439 	/* Caller will stuff the pending registers. */
    440 	return (0);
    441 }
    442 
    443 int
    444 zs_set_modes(struct zs_chanstate *cs, int cflag	/* bits per second */)
    445 {
    446 	int s;
    447 
    448 	/*
    449 	 * Output hardware flow control on the chip is horrendous:
    450 	 * if carrier detect drops, the receiver is disabled, and if
    451 	 * CTS drops, the transmitter is stoped IN MID CHARACTER!
    452 	 * Therefore, NEVER set the HFC bit, and instead use the
    453 	 * status interrupt to detect CTS changes.
    454 	 */
    455 	s = splzs();
    456 	cs->cs_rr0_pps = 0;
    457 	if ((cflag & (CLOCAL | MDMBUF)) != 0) {
    458 		cs->cs_rr0_dcd = 0;
    459 		if ((cflag & MDMBUF) == 0)
    460 			cs->cs_rr0_pps = ZSRR0_DCD;
    461 	} else
    462 		cs->cs_rr0_dcd = ZSRR0_DCD;
    463 	if ((cflag & CRTSCTS) != 0) {
    464 		cs->cs_wr5_dtr = ZSWR5_DTR;
    465 		cs->cs_wr5_rts = ZSWR5_RTS;
    466 		cs->cs_rr0_cts = ZSRR0_CTS;
    467 	} else if ((cflag & CDTRCTS) != 0) {
    468 		cs->cs_wr5_dtr = 0;
    469 		cs->cs_wr5_rts = ZSWR5_DTR;
    470 		cs->cs_rr0_cts = ZSRR0_CTS;
    471 	} else if ((cflag & MDMBUF) != 0) {
    472 		cs->cs_wr5_dtr = 0;
    473 		cs->cs_wr5_rts = ZSWR5_DTR;
    474 		cs->cs_rr0_cts = ZSRR0_DCD;
    475 	} else {
    476 		cs->cs_wr5_dtr = ZSWR5_DTR | ZSWR5_RTS;
    477 		cs->cs_wr5_rts = 0;
    478 		cs->cs_rr0_cts = 0;
    479 	}
    480 	splx(s);
    481 
    482 	/* Caller will stuff the pending registers. */
    483 	return (0);
    484 }
    485 
    486 
    487 /*
    488  * Read or write the chip with suitable delays.
    489  */
    490 
    491 u_char
    492 zs_read_reg(struct zs_chanstate *cs, u_char reg)
    493 {
    494 	u_char val;
    495 
    496 	*cs->cs_reg_csr = reg;
    497 	ZS_DELAY();
    498 	val = *cs->cs_reg_csr;
    499 	ZS_DELAY();
    500 	return (val);
    501 }
    502 
    503 void
    504 zs_write_reg(struct zs_chanstate *cs, u_char reg, u_char val)
    505 {
    506 	*cs->cs_reg_csr = reg;
    507 	ZS_DELAY();
    508 	*cs->cs_reg_csr = val;
    509 	ZS_DELAY();
    510 }
    511 
    512 u_char
    513 zs_read_csr(struct zs_chanstate *cs)
    514 {
    515 	u_char val;
    516 
    517 	val = *cs->cs_reg_csr;
    518 	ZS_DELAY();
    519 	return (val);
    520 }
    521 
    522 void
    523 zs_write_csr(struct zs_chanstate *cs, u_char val)
    524 {
    525 	*cs->cs_reg_csr = val;
    526 	ZS_DELAY();
    527 }
    528 
    529 u_char
    530 zs_read_data(struct zs_chanstate *cs)
    531 {
    532 	u_char val;
    533 
    534 	val = *cs->cs_reg_data;
    535 	ZS_DELAY();
    536 	return (val);
    537 }
    538 
    539 void
    540 zs_write_data(struct zs_chanstate *cs, u_char val)
    541 {
    542 	*cs->cs_reg_data = val;
    543 	ZS_DELAY();
    544 }
    545 
    546 /****************************************************************
    547  * Console support functions (Sun specific!)
    548  * Note: this code is allowed to know about the layout of
    549  * the chip registers, and uses that to keep things simple.
    550  * XXX - I think I like the mvme167 code better. -gwr
    551  ****************************************************************/
    552 
    553 extern void Debugger(void);
    554 
    555 /*
    556  * Handle user request to enter kernel debugger.
    557  */
    558 void
    559 zs_abort(struct zs_chanstate *cs)
    560 {
    561 	volatile struct zschan *zc = zs_conschan_get;
    562 	int rr0;
    563 
    564 	/* Wait for end of break to avoid PROM abort. */
    565 	/* XXX - Limit the wait? */
    566 	do {
    567 		rr0 = zc->zc_csr;
    568 		ZS_DELAY();
    569 	} while (rr0 & ZSRR0_BREAK);
    570 
    571 #if defined(KGDB)
    572 	zskgdb(cs);
    573 #elif defined(DDB)
    574 	{
    575 		extern int db_active;
    576 
    577 		if (!db_active)
    578 			Debugger();
    579 		else
    580 			/* Debugger is probably hozed */
    581 			callrom();
    582 	}
    583 #else
    584 	printf("stopping on keyboard abort\n");
    585 	callrom();
    586 #endif
    587 }
    588 
    589 
    590 /*
    591  * Polled input char.
    592  */
    593 int
    594 zs_getc(void *arg)
    595 {
    596 	volatile struct zschan *zc = arg;
    597 	int s, c, rr0;
    598 
    599 	s = splhigh();
    600 	/* Wait for a character to arrive. */
    601 	do {
    602 		rr0 = zc->zc_csr;
    603 		ZS_DELAY();
    604 	} while ((rr0 & ZSRR0_RX_READY) == 0);
    605 
    606 	c = zc->zc_data;
    607 	ZS_DELAY();
    608 	splx(s);
    609 
    610 	/*
    611 	 * This is used by the kd driver to read scan codes,
    612 	 * so don't translate '\r' ==> '\n' here...
    613 	 */
    614 	return (c);
    615 }
    616 
    617 /*
    618  * Polled output char.
    619  */
    620 void
    621 zs_putc(void *arg, int c)
    622 {
    623 	volatile struct zschan *zc = arg;
    624 	int s, rr0;
    625 
    626 	s = splhigh();
    627 
    628 	/* Wait for transmitter to become ready. */
    629 	do {
    630 		rr0 = zc->zc_csr;
    631 		ZS_DELAY();
    632 	} while ((rr0 & ZSRR0_TX_READY) == 0);
    633 
    634 	/*
    635 	 * Send the next character.
    636 	 * Now you'd think that this could be followed by a ZS_DELAY()
    637 	 * just like all the other chip accesses, but it turns out that
    638 	 * the `transmit-ready' interrupt isn't de-asserted until
    639 	 * some period of time after the register write completes
    640 	 * (more than a couple instructions).  So to avoid stray
    641 	 * interrupts we put in the 2us delay regardless of CPU model.
    642 	 */
    643 	zc->zc_data = c;
    644 	delay(2);
    645 
    646 	splx(s);
    647 }
    648 
    649 /*****************************************************************/
    650 
    651 
    652 
    653 
    654 /*
    655  * Polled console input putchar.
    656  */
    657 static int
    658 zscngetc(dev_t dev)
    659 {
    660 	return (zs_getc(zs_conschan_get));
    661 }
    662 
    663 /*
    664  * Polled console output putchar.
    665  */
    666 static void
    667 zscnputc(dev_t dev, int c)
    668 {
    669 	zs_putc(zs_conschan_put, c);
    670 }
    671 
    672 int swallow_zsintrs;
    673 
    674 static void
    675 zscnpollc(dev_t dev, int on)
    676 {
    677 	/*
    678 	 * Need to tell zs driver to acknowledge all interrupts or we get
    679 	 * annoying spurious interrupt messages.  This is because mucking
    680 	 * with spl() levels during polling does not prevent interrupts from
    681 	 * being generated.
    682 	 */
    683 
    684 	if (on) swallow_zsintrs++;
    685 	else swallow_zsintrs--;
    686 }
    687 
    688