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dz.c revision 1.1.8.2
      1 /*	$NetBSD: dz.c,v 1.1.8.2 2002/03/16 16:00:50 jdolecek Exp $	*/
      2 /*
      3  * Copyright (c) 1996  Ken C. Wellsch.  All rights reserved.
      4  * Copyright (c) 1992, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * This code is derived from software contributed to Berkeley by
      8  * Ralph Campbell and Rick Macklem.
      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 University of
     21  *	California, Berkeley and its contributors.
     22  * 4. Neither the name of the University nor the names of its contributors
     23  *    may be used to endorse or promote products derived from this software
     24  *    without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     36  * SUCH DAMAGE.
     37  */
     38 
     39 #include <sys/cdefs.h>
     40 __KERNEL_RCSID(0, "$NetBSD: dz.c,v 1.1.8.2 2002/03/16 16:00:50 jdolecek Exp $");
     41 
     42 #include "opt_ddb.h"
     43 
     44 #include <sys/param.h>
     45 #include <sys/systm.h>
     46 #include <sys/callout.h>
     47 #include <sys/ioctl.h>
     48 #include <sys/tty.h>
     49 #include <sys/proc.h>
     50 #include <sys/map.h>
     51 #include <sys/buf.h>
     52 #include <sys/conf.h>
     53 #include <sys/file.h>
     54 #include <sys/uio.h>
     55 #include <sys/kernel.h>
     56 #include <sys/syslog.h>
     57 #include <sys/device.h>
     58 
     59 #include <machine/bus.h>
     60 
     61 #include <dev/dec/dzreg.h>
     62 #include <dev/dec/dzvar.h>
     63 
     64 #define	DZ_READ_BYTE(adr) \
     65 	bus_space_read_1(sc->sc_iot, sc->sc_ioh, sc->sc_dr.adr)
     66 #define	DZ_READ_WORD(adr) \
     67 	bus_space_read_2(sc->sc_iot, sc->sc_ioh, sc->sc_dr.adr)
     68 #define	DZ_WRITE_BYTE(adr, val) \
     69 	bus_space_write_1(sc->sc_iot, sc->sc_ioh, sc->sc_dr.adr, val)
     70 #define	DZ_WRITE_WORD(adr, val) \
     71 	bus_space_write_2(sc->sc_iot, sc->sc_ioh, sc->sc_dr.adr, val)
     72 
     73 #include "ioconf.h"
     74 
     75 /* A DZ-11 has 8 ports while a DZV/DZQ-11 has only 4. We use 8 by default */
     76 
     77 #define	NDZLINE 	8
     78 
     79 #define DZ_C2I(c)	((c)<<3)	/* convert controller # to index */
     80 #define DZ_I2C(c)	((c)>>3)	/* convert minor to controller # */
     81 #define DZ_PORT(u)	((u)&07)	/* extract the port # */
     82 
     83 /* Flags used to monitor modem bits, make them understood outside driver */
     84 
     85 #define DML_DTR		TIOCM_DTR
     86 #define DML_DCD		TIOCM_CD
     87 #define DML_RI		TIOCM_RI
     88 #define DML_BRK		0100000		/* no equivalent, we will mask */
     89 
     90 static struct speedtab dzspeedtab[] =
     91 {
     92   {       0,	0		},
     93   {      50,	DZ_LPR_B50	},
     94   {      75,	DZ_LPR_B75	},
     95   {     110,	DZ_LPR_B110	},
     96   {     134,	DZ_LPR_B134	},
     97   {     150,	DZ_LPR_B150	},
     98   {     300,	DZ_LPR_B300	},
     99   {     600,	DZ_LPR_B600	},
    100   {    1200,	DZ_LPR_B1200	},
    101   {    1800,	DZ_LPR_B1800	},
    102   {    2000,	DZ_LPR_B2000	},
    103   {    2400,	DZ_LPR_B2400	},
    104   {    3600,	DZ_LPR_B3600	},
    105   {    4800,	DZ_LPR_B4800	},
    106   {    7200,	DZ_LPR_B7200	},
    107   {    9600,	DZ_LPR_B9600	},
    108   {   19200,	DZ_LPR_B19200	},
    109   {      -1,	-1		}
    110 };
    111 
    112 static void	dzstart(struct tty *);
    113 static int	dzparam(struct tty *, struct termios *);
    114 static unsigned	dzmctl(struct dz_softc *, int, int, int);
    115 static void	dzscan(void *);
    116 cdev_decl(dz);
    117 
    118 /*
    119  * The DZ series doesn't interrupt on carrier transitions,
    120  * so we have to use a timer to watch it.
    121  */
    122 int	dz_timer;	/* true if timer started */
    123 struct callout dzscan_ch;
    124 
    125 #define DZ_DZ	8		/* Unibus DZ-11 board linecount */
    126 #define DZ_DZV	4		/* Q-bus DZV-11 or DZQ-11 */
    127 
    128 void
    129 dzattach(struct dz_softc *sc, struct evcnt *parent_evcnt)
    130 {
    131 	int n;
    132 
    133 	sc->sc_rxint = sc->sc_brk = 0;
    134 
    135 	sc->sc_dr.dr_tcrw = sc->sc_dr.dr_tcr;
    136 	DZ_WRITE_WORD(dr_csr, DZ_CSR_MSE | DZ_CSR_RXIE | DZ_CSR_TXIE);
    137 	DZ_WRITE_BYTE(dr_dtr, 0);
    138 	DZ_WRITE_BYTE(dr_break, 0);
    139 
    140 	/* Initialize our softc structure. Should be done in open? */
    141 
    142 	for (n = 0; n < sc->sc_type; n++)
    143 		sc->sc_dz[n].dz_tty = ttymalloc();
    144 
    145 	evcnt_attach_dynamic(&sc->sc_rintrcnt, EVCNT_TYPE_INTR, parent_evcnt,
    146 		sc->sc_dev.dv_xname, "rintr");
    147 	evcnt_attach_dynamic(&sc->sc_tintrcnt, EVCNT_TYPE_INTR, parent_evcnt,
    148 		sc->sc_dev.dv_xname, "tintr");
    149 
    150 	/* Alas no interrupt on modem bit changes, so we manually scan */
    151 
    152 	if (dz_timer == 0) {
    153 		dz_timer = 1;
    154 		callout_init(&dzscan_ch);
    155 		callout_reset(&dzscan_ch, hz, dzscan, NULL);
    156 	}
    157 	printf("\n");
    158 	return;
    159 }
    160 
    161 /* Receiver Interrupt */
    162 
    163 void
    164 dzrint(void *arg)
    165 {
    166 	struct dz_softc *sc = arg;
    167 	struct tty *tp;
    168 	int cc, line;
    169 	unsigned c;
    170 	int overrun = 0;
    171 
    172 	sc->sc_rxint++;
    173 
    174 	while ((c = DZ_READ_WORD(dr_rbuf)) & DZ_RBUF_DATA_VALID) {
    175 		cc = c & 0xFF;
    176 		line = DZ_PORT(c>>8);
    177 		tp = sc->sc_dz[line].dz_tty;
    178 
    179 		/* Must be caught early */
    180 		if (sc->sc_dz[line].dz_catch &&
    181 		    (*sc->sc_dz[line].dz_catch)(sc->sc_dz[line].dz_private, cc))
    182 			continue;
    183 
    184 		if (!(tp->t_state & TS_ISOPEN)) {
    185 			wakeup((caddr_t)&tp->t_rawq);
    186 			continue;
    187 		}
    188 
    189 		if ((c & DZ_RBUF_OVERRUN_ERR) && overrun == 0) {
    190 			log(LOG_WARNING, "%s: silo overflow, line %d\n",
    191 			    sc->sc_dev.dv_xname, line);
    192 			overrun = 1;
    193 		}
    194 
    195 		/* A BREAK key will appear as a NULL with a framing error */
    196 		if (c & DZ_RBUF_FRAMING_ERR)
    197 			cc |= TTY_FE;
    198 		if (c & DZ_RBUF_PARITY_ERR)
    199 			cc |= TTY_PE;
    200 
    201 		(*tp->t_linesw->l_rint)(cc, tp);
    202 	}
    203 }
    204 
    205 /* Transmitter Interrupt */
    206 
    207 void
    208 dzxint(void *arg)
    209 {
    210 	struct dz_softc *sc = arg;
    211 	struct tty *tp;
    212 	struct clist *cl;
    213 	int line, ch, csr;
    214 	u_char tcr;
    215 
    216 	/*
    217 	 * Switch to POLLED mode.
    218 	 *   Some simple measurements indicated that even on
    219 	 *  one port, by freeing the scanner in the controller
    220 	 *  by either providing a character or turning off
    221 	 *  the port when output is complete, the transmitter
    222 	 *  was ready to accept more output when polled again.
    223 	 *   With just two ports running the game "worms,"
    224 	 *  almost every interrupt serviced both transmitters!
    225 	 *   Each UART is double buffered, so if the scanner
    226 	 *  is quick enough and timing works out, we can even
    227 	 *  feed the same port twice.
    228 	 *
    229 	 * Ragge 980517:
    230 	 * Do not need to turn off interrupts, already at interrupt level.
    231 	 * Remove the pdma stuff; no great need of it right now.
    232 	 */
    233 
    234 	while (((csr = DZ_READ_WORD(dr_csr)) & DZ_CSR_TX_READY) != 0) {
    235 
    236 		line = DZ_PORT(csr>>8);
    237 
    238 		tp = sc->sc_dz[line].dz_tty;
    239 		cl = &tp->t_outq;
    240 		tp->t_state &= ~TS_BUSY;
    241 
    242 		/* Just send out a char if we have one */
    243 		/* As long as we can fill the chip buffer, we just loop here */
    244 		if (cl->c_cc) {
    245 			tp->t_state |= TS_BUSY;
    246 			ch = getc(cl);
    247 			DZ_WRITE_BYTE(dr_tbuf, ch);
    248 			continue;
    249 		}
    250 		/* Nothing to send; clear the scan bit */
    251 		/* Clear xmit scanner bit; dzstart may set it again */
    252 		tcr = DZ_READ_WORD(dr_tcrw);
    253 		tcr &= 255;
    254 		tcr &= ~(1 << line);
    255 		DZ_WRITE_BYTE(dr_tcr, tcr);
    256 		if (sc->sc_dz[line].dz_catch)
    257 			continue;
    258 
    259 		if (tp->t_state & TS_FLUSH)
    260 			tp->t_state &= ~TS_FLUSH;
    261 		else
    262 			ndflush (&tp->t_outq, cl->c_cc);
    263 
    264 		(*tp->t_linesw->l_start)(tp);
    265 	}
    266 }
    267 
    268 int
    269 dzopen(dev_t dev, int flag, int mode, struct proc *p)
    270 {
    271 	struct tty *tp;
    272 	int unit, line;
    273 	struct	dz_softc *sc;
    274 	int s, error = 0;
    275 
    276 	unit = DZ_I2C(minor(dev));
    277 	line = DZ_PORT(minor(dev));
    278 	if (unit >= dz_cd.cd_ndevs ||  dz_cd.cd_devs[unit] == NULL)
    279 		return (ENXIO);
    280 
    281 	sc = dz_cd.cd_devs[unit];
    282 
    283 	if (line >= sc->sc_type)
    284 		return ENXIO;
    285 
    286 	/* if some other device is using the line, it's busy */
    287 	if (sc->sc_dz[line].dz_catch)
    288 		return EBUSY;
    289 
    290 	tp = sc->sc_dz[line].dz_tty;
    291 	if (tp == NULL)
    292 		return (ENODEV);
    293 	tp->t_oproc   = dzstart;
    294 	tp->t_param   = dzparam;
    295 	tp->t_dev = dev;
    296 	if ((tp->t_state & TS_ISOPEN) == 0) {
    297 		ttychars(tp);
    298 		if (tp->t_ispeed == 0) {
    299 			tp->t_iflag = TTYDEF_IFLAG;
    300 			tp->t_oflag = TTYDEF_OFLAG;
    301 			tp->t_cflag = TTYDEF_CFLAG;
    302 			tp->t_lflag = TTYDEF_LFLAG;
    303 			tp->t_ispeed = tp->t_ospeed = TTYDEF_SPEED;
    304 		}
    305 		(void) dzparam(tp, &tp->t_termios);
    306 		ttsetwater(tp);
    307 	} else if ((tp->t_state & TS_XCLUDE) && p->p_ucred->cr_uid != 0)
    308 		return (EBUSY);
    309 	/* Use DMBIS and *not* DMSET or else we clobber incoming bits */
    310 	if (dzmctl(sc, line, DML_DTR, DMBIS) & DML_DCD)
    311 		tp->t_state |= TS_CARR_ON;
    312 	s = spltty();
    313 	while (!(flag & O_NONBLOCK) && !(tp->t_cflag & CLOCAL) &&
    314 	       !(tp->t_state & TS_CARR_ON)) {
    315 		tp->t_wopen++;
    316 		error = ttysleep(tp, (caddr_t)&tp->t_rawq,
    317 				TTIPRI | PCATCH, ttopen, 0);
    318 		tp->t_wopen--;
    319 		if (error)
    320 			break;
    321 	}
    322 	(void) splx(s);
    323 	if (error)
    324 		return (error);
    325 	return ((*tp->t_linesw->l_open)(dev, tp));
    326 }
    327 
    328 /*ARGSUSED*/
    329 int
    330 dzclose(dev_t dev, int flag, int mode, struct proc *p)
    331 {
    332 	struct	dz_softc *sc;
    333 	struct tty *tp;
    334 	int unit, line;
    335 
    336 
    337 	unit = DZ_I2C(minor(dev));
    338 	line = DZ_PORT(minor(dev));
    339 	sc = dz_cd.cd_devs[unit];
    340 
    341 	tp = sc->sc_dz[line].dz_tty;
    342 
    343 	(*tp->t_linesw->l_close)(tp, flag);
    344 
    345 	/* Make sure a BREAK state is not left enabled. */
    346 	(void) dzmctl(sc, line, DML_BRK, DMBIC);
    347 
    348 	/* Do a hangup if so required. */
    349 	if ((tp->t_cflag & HUPCL) || tp->t_wopen || !(tp->t_state & TS_ISOPEN))
    350 		(void) dzmctl(sc, line, 0, DMSET);
    351 
    352 	return (ttyclose(tp));
    353 }
    354 
    355 int
    356 dzread(dev_t dev, struct uio *uio, int flag)
    357 {
    358 	struct tty *tp;
    359 	struct	dz_softc *sc;
    360 
    361 	sc = dz_cd.cd_devs[DZ_I2C(minor(dev))];
    362 
    363 	tp = sc->sc_dz[DZ_PORT(minor(dev))].dz_tty;
    364 	return ((*tp->t_linesw->l_read)(tp, uio, flag));
    365 }
    366 
    367 int
    368 dzwrite(dev_t dev, struct uio *uio, int flag)
    369 {
    370 	struct tty *tp;
    371 	struct	dz_softc *sc;
    372 
    373 	sc = dz_cd.cd_devs[DZ_I2C(minor(dev))];
    374 
    375 	tp = sc->sc_dz[DZ_PORT(minor(dev))].dz_tty;
    376 	return ((*tp->t_linesw->l_write)(tp, uio, flag));
    377 }
    378 
    379 int
    380 dzpoll(dev, events, p)
    381 	dev_t dev;
    382 	int events;
    383 	struct proc *p;
    384 {
    385 	struct tty *tp;
    386 	struct	dz_softc *sc;
    387 
    388 	sc = dz_cd.cd_devs[DZ_I2C(minor(dev))];
    389 
    390 	tp = sc->sc_dz[DZ_PORT(minor(dev))].dz_tty;
    391 	return ((*tp->t_linesw->l_poll)(tp, events, p));
    392 }
    393 
    394 /*ARGSUSED*/
    395 int
    396 dzioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct proc *p)
    397 {
    398 	struct	dz_softc *sc;
    399 	struct tty *tp;
    400 	int unit, line;
    401 	int error;
    402 
    403 	unit = DZ_I2C(minor(dev));
    404 	line = DZ_PORT(minor(dev));
    405 	sc = dz_cd.cd_devs[unit];
    406 	tp = sc->sc_dz[line].dz_tty;
    407 
    408 	error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, p);
    409 	if (error >= 0)
    410 		return (error);
    411 	error = ttioctl(tp, cmd, data, flag, p);
    412 	if (error >= 0)
    413 		return (error);
    414 
    415 	switch (cmd) {
    416 
    417 	case TIOCSBRK:
    418 		(void) dzmctl(sc, line, DML_BRK, DMBIS);
    419 		break;
    420 
    421 	case TIOCCBRK:
    422 		(void) dzmctl(sc, line, DML_BRK, DMBIC);
    423 		break;
    424 
    425 	case TIOCSDTR:
    426 		(void) dzmctl(sc, line, DML_DTR, DMBIS);
    427 		break;
    428 
    429 	case TIOCCDTR:
    430 		(void) dzmctl(sc, line, DML_DTR, DMBIC);
    431 		break;
    432 
    433 	case TIOCMSET:
    434 		(void) dzmctl(sc, line, *(int *)data, DMSET);
    435 		break;
    436 
    437 	case TIOCMBIS:
    438 		(void) dzmctl(sc, line, *(int *)data, DMBIS);
    439 		break;
    440 
    441 	case TIOCMBIC:
    442 		(void) dzmctl(sc, line, *(int *)data, DMBIC);
    443 		break;
    444 
    445 	case TIOCMGET:
    446 		*(int *)data = (dzmctl(sc, line, 0, DMGET) & ~DML_BRK);
    447 		break;
    448 
    449 	default:
    450 		return (ENOTTY);
    451 	}
    452 	return (0);
    453 }
    454 
    455 struct tty *
    456 dztty(dev_t dev)
    457 {
    458 	struct	dz_softc *sc = dz_cd.cd_devs[DZ_I2C(minor(dev))];
    459         struct tty *tp = sc->sc_dz[DZ_PORT(minor(dev))].dz_tty;
    460 
    461         return (tp);
    462 }
    463 
    464 /*ARGSUSED*/
    465 void
    466 dzstop(struct tty *tp, int flag)
    467 {
    468 	if (tp->t_state & TS_BUSY)
    469 		if (!(tp->t_state & TS_TTSTOP))
    470 			tp->t_state |= TS_FLUSH;
    471 }
    472 
    473 void
    474 dzstart(struct tty *tp)
    475 {
    476 	struct dz_softc *sc;
    477 	struct clist *cl;
    478 	int unit, line, s;
    479 	char state;
    480 
    481 	unit = DZ_I2C(minor(tp->t_dev));
    482 	line = DZ_PORT(minor(tp->t_dev));
    483 	sc = dz_cd.cd_devs[unit];
    484 
    485 	s = spltty();
    486 	if (tp->t_state & (TS_TIMEOUT|TS_BUSY|TS_TTSTOP))
    487 		return;
    488 	cl = &tp->t_outq;
    489 	if (cl->c_cc <= tp->t_lowat) {
    490 		if (tp->t_state & TS_ASLEEP) {
    491 			tp->t_state &= ~TS_ASLEEP;
    492 			wakeup((caddr_t)cl);
    493 		}
    494 		selwakeup(&tp->t_wsel);
    495 	}
    496 	if (cl->c_cc == 0)
    497 		return;
    498 
    499 	tp->t_state |= TS_BUSY;
    500 
    501 	state = DZ_READ_WORD(dr_tcrw) & 255;
    502 	if ((state & (1 << line)) == 0) {
    503 		DZ_WRITE_BYTE(dr_tcr, state | (1 << line));
    504 	}
    505 	dzxint(sc);
    506 	splx(s);
    507 }
    508 
    509 static int
    510 dzparam(struct tty *tp, struct termios *t)
    511 {
    512 	struct	dz_softc *sc;
    513 	int cflag = t->c_cflag;
    514 	int unit, line;
    515 	int ispeed = ttspeedtab(t->c_ispeed, dzspeedtab);
    516 	int ospeed = ttspeedtab(t->c_ospeed, dzspeedtab);
    517 	unsigned lpr;
    518 	int s;
    519 
    520 	unit = DZ_I2C(minor(tp->t_dev));
    521 	line = DZ_PORT(minor(tp->t_dev));
    522 	sc = dz_cd.cd_devs[unit];
    523 
    524 	/* check requested parameters */
    525         if (ospeed < 0 || ispeed < 0 || ispeed != ospeed)
    526                 return (EINVAL);
    527 
    528         tp->t_ispeed = t->c_ispeed;
    529         tp->t_ospeed = t->c_ospeed;
    530         tp->t_cflag = cflag;
    531 
    532 	if (ospeed == 0) {
    533 		(void) dzmctl(sc, line, 0, DMSET);	/* hang up line */
    534 		return (0);
    535 	}
    536 
    537 	s = spltty();
    538 
    539 	lpr = DZ_LPR_RX_ENABLE | ((ispeed&0xF)<<8) | line;
    540 
    541 	switch (cflag & CSIZE)
    542 	{
    543 	  case CS5:
    544 		lpr |= DZ_LPR_5_BIT_CHAR;
    545 		break;
    546 	  case CS6:
    547 		lpr |= DZ_LPR_6_BIT_CHAR;
    548 		break;
    549 	  case CS7:
    550 		lpr |= DZ_LPR_7_BIT_CHAR;
    551 		break;
    552 	  default:
    553 		lpr |= DZ_LPR_8_BIT_CHAR;
    554 		break;
    555 	}
    556 	if (cflag & PARENB)
    557 		lpr |= DZ_LPR_PARENB;
    558 	if (cflag & PARODD)
    559 		lpr |= DZ_LPR_OPAR;
    560 	if (cflag & CSTOPB)
    561 		lpr |= DZ_LPR_2_STOP;
    562 
    563 	DZ_WRITE_WORD(dr_lpr, lpr);
    564 
    565 	(void) splx(s);
    566 	return (0);
    567 }
    568 
    569 static unsigned
    570 dzmctl(struct dz_softc *sc, int line, int bits, int how)
    571 {
    572 	unsigned status;
    573 	unsigned mbits;
    574 	unsigned bit;
    575 	int s;
    576 
    577 	s = spltty();
    578 
    579 	mbits = 0;
    580 
    581 	bit = (1 << line);
    582 
    583 	/* external signals as seen from the port */
    584 
    585 	status = DZ_READ_BYTE(dr_dcd) | sc->sc_dsr;
    586 
    587 	if (status & bit)
    588 		mbits |= DML_DCD;
    589 
    590 	status = DZ_READ_BYTE(dr_ring);
    591 
    592 	if (status & bit)
    593 		mbits |= DML_RI;
    594 
    595 	/* internal signals/state delivered to port */
    596 
    597 	status = DZ_READ_BYTE(dr_dtr);
    598 
    599 	if (status & bit)
    600 		mbits |= DML_DTR;
    601 
    602 	if (sc->sc_brk & bit)
    603 		mbits |= DML_BRK;
    604 
    605 	switch (how)
    606 	{
    607 	  case DMSET:
    608 		mbits = bits;
    609 		break;
    610 
    611 	  case DMBIS:
    612 		mbits |= bits;
    613 		break;
    614 
    615 	  case DMBIC:
    616 		mbits &= ~bits;
    617 		break;
    618 
    619 	  case DMGET:
    620 		(void) splx(s);
    621 		return (mbits);
    622 	}
    623 
    624 	if (mbits & DML_DTR) {
    625 		DZ_WRITE_BYTE(dr_dtr, DZ_READ_BYTE(dr_dtr) | bit);
    626 	} else {
    627 		DZ_WRITE_BYTE(dr_dtr, DZ_READ_BYTE(dr_dtr) & ~bit);
    628 	}
    629 
    630 	if (mbits & DML_BRK) {
    631 		sc->sc_brk |= bit;
    632 		DZ_WRITE_BYTE(dr_break, sc->sc_brk);
    633 	} else {
    634 		sc->sc_brk &= ~bit;
    635 		DZ_WRITE_BYTE(dr_break, sc->sc_brk);
    636 	}
    637 
    638 	(void) splx(s);
    639 	return (mbits);
    640 }
    641 
    642 /*
    643  * This is called by timeout() periodically.
    644  * Check to see if modem status bits have changed.
    645  */
    646 static void
    647 dzscan(void *arg)
    648 {
    649 	struct dz_softc *sc;
    650 	struct tty *tp;
    651 	int n, bit, port;
    652 	unsigned csr;
    653 	int s;
    654 
    655 	s = spltty();
    656 
    657 	for (n = 0; n < dz_cd.cd_ndevs; n++) {
    658 
    659 		if (dz_cd.cd_devs[n] == NULL)
    660 			continue;
    661 
    662 		sc = dz_cd.cd_devs[n];
    663 
    664 		for (port = 0; port < sc->sc_type; port++) {
    665 
    666 			tp = sc->sc_dz[port].dz_tty;
    667 			bit = (1 << port);
    668 
    669 			if ((DZ_READ_BYTE(dr_dcd) | sc->sc_dsr) & bit) {
    670 				if (!(tp->t_state & TS_CARR_ON))
    671 					(*tp->t_linesw->l_modem) (tp, 1);
    672 			} else if ((tp->t_state & TS_CARR_ON) &&
    673 			    (*tp->t_linesw->l_modem)(tp, 0) == 0) {
    674 				DZ_WRITE_BYTE(dr_tcr,
    675 				    (DZ_READ_WORD(dr_tcrw) & 255) & ~bit);
    676 			}
    677 	    	}
    678 
    679 		/*
    680 		 *  If the RX interrupt rate is this high, switch
    681 		 *  the controller to Silo Alarm - which means don't
    682 	 	 *  interrupt until the RX silo has 16 characters in
    683 	 	 *  it (the silo is 64 characters in all).
    684 		 *  Avoid oscillating SA on and off by not turning
    685 		 *  if off unless the rate is appropriately low.
    686 		 */
    687 
    688 		csr = DZ_READ_WORD(dr_csr);
    689 
    690 		if (sc->sc_rxint > (16*10)) {
    691 			if ((csr & DZ_CSR_SAE) == 0)
    692 				DZ_WRITE_WORD(dr_csr, csr | DZ_CSR_SAE);
    693 	    	} else if ((csr & DZ_CSR_SAE) != 0)
    694 			if (sc->sc_rxint < 10)
    695 				DZ_WRITE_WORD(dr_csr, csr & ~(DZ_CSR_SAE));
    696 
    697 		sc->sc_rxint = 0;
    698 	}
    699 	(void) splx(s);
    700 	callout_reset(&dzscan_ch, hz, dzscan, NULL);
    701 	return;
    702 }
    703 
    704 /*
    705  * Called after an ubareset. The DZ card is reset, but the only thing
    706  * that must be done is to start the receiver and transmitter again.
    707  * No DMA setup to care about.
    708  */
    709 void
    710 dzreset(struct device *dev)
    711 {
    712 	struct dz_softc *sc = (void *)dev;
    713 	struct tty *tp;
    714 	int i;
    715 
    716 	for (i = 0; i < sc->sc_type; i++) {
    717 		tp = sc->sc_dz[i].dz_tty;
    718 
    719 		if (((tp->t_state & TS_ISOPEN) == 0) || (tp->t_wopen == 0))
    720 			continue;
    721 
    722 		dzparam(tp, &tp->t_termios);
    723 		dzmctl(sc, i, DML_DTR, DMSET);
    724 		tp->t_state &= ~TS_BUSY;
    725 		dzstart(tp);	/* Kick off transmitter again */
    726 	}
    727 }
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