xref: /netbsd/sys/dev/dec/dz.c (revision bf9ec67e)
1 /*	$NetBSD: dz.c,v 1.2 2002/03/17 19:40:54 atatat 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 1.2 2002/03/17 19:40:54 atatat 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 
412 	error = ttioctl(tp, cmd, data, flag, p);
413 	if (error >= 0)
414 		return (error);
415 
416 	switch (cmd) {
417 
418 	case TIOCSBRK:
419 		(void) dzmctl(sc, line, DML_BRK, DMBIS);
420 		break;
421 
422 	case TIOCCBRK:
423 		(void) dzmctl(sc, line, DML_BRK, DMBIC);
424 		break;
425 
426 	case TIOCSDTR:
427 		(void) dzmctl(sc, line, DML_DTR, DMBIS);
428 		break;
429 
430 	case TIOCCDTR:
431 		(void) dzmctl(sc, line, DML_DTR, DMBIC);
432 		break;
433 
434 	case TIOCMSET:
435 		(void) dzmctl(sc, line, *(int *)data, DMSET);
436 		break;
437 
438 	case TIOCMBIS:
439 		(void) dzmctl(sc, line, *(int *)data, DMBIS);
440 		break;
441 
442 	case TIOCMBIC:
443 		(void) dzmctl(sc, line, *(int *)data, DMBIC);
444 		break;
445 
446 	case TIOCMGET:
447 		*(int *)data = (dzmctl(sc, line, 0, DMGET) & ~DML_BRK);
448 		break;
449 
450 	default:
451 		return (EPASSTHROUGH);
452 	}
453 	return (0);
454 }
455 
456 struct tty *
457 dztty(dev_t dev)
458 {
459 	struct	dz_softc *sc = dz_cd.cd_devs[DZ_I2C(minor(dev))];
460         struct tty *tp = sc->sc_dz[DZ_PORT(minor(dev))].dz_tty;
461 
462         return (tp);
463 }
464 
465 /*ARGSUSED*/
466 void
467 dzstop(struct tty *tp, int flag)
468 {
469 	if (tp->t_state & TS_BUSY)
470 		if (!(tp->t_state & TS_TTSTOP))
471 			tp->t_state |= TS_FLUSH;
472 }
473 
474 void
475 dzstart(struct tty *tp)
476 {
477 	struct dz_softc *sc;
478 	struct clist *cl;
479 	int unit, line, s;
480 	char state;
481 
482 	unit = DZ_I2C(minor(tp->t_dev));
483 	line = DZ_PORT(minor(tp->t_dev));
484 	sc = dz_cd.cd_devs[unit];
485 
486 	s = spltty();
487 	if (tp->t_state & (TS_TIMEOUT|TS_BUSY|TS_TTSTOP))
488 		return;
489 	cl = &tp->t_outq;
490 	if (cl->c_cc <= tp->t_lowat) {
491 		if (tp->t_state & TS_ASLEEP) {
492 			tp->t_state &= ~TS_ASLEEP;
493 			wakeup((caddr_t)cl);
494 		}
495 		selwakeup(&tp->t_wsel);
496 	}
497 	if (cl->c_cc == 0)
498 		return;
499 
500 	tp->t_state |= TS_BUSY;
501 
502 	state = DZ_READ_WORD(dr_tcrw) & 255;
503 	if ((state & (1 << line)) == 0) {
504 		DZ_WRITE_BYTE(dr_tcr, state | (1 << line));
505 	}
506 	dzxint(sc);
507 	splx(s);
508 }
509 
510 static int
511 dzparam(struct tty *tp, struct termios *t)
512 {
513 	struct	dz_softc *sc;
514 	int cflag = t->c_cflag;
515 	int unit, line;
516 	int ispeed = ttspeedtab(t->c_ispeed, dzspeedtab);
517 	int ospeed = ttspeedtab(t->c_ospeed, dzspeedtab);
518 	unsigned lpr;
519 	int s;
520 
521 	unit = DZ_I2C(minor(tp->t_dev));
522 	line = DZ_PORT(minor(tp->t_dev));
523 	sc = dz_cd.cd_devs[unit];
524 
525 	/* check requested parameters */
526         if (ospeed < 0 || ispeed < 0 || ispeed != ospeed)
527                 return (EINVAL);
528 
529         tp->t_ispeed = t->c_ispeed;
530         tp->t_ospeed = t->c_ospeed;
531         tp->t_cflag = cflag;
532 
533 	if (ospeed == 0) {
534 		(void) dzmctl(sc, line, 0, DMSET);	/* hang up line */
535 		return (0);
536 	}
537 
538 	s = spltty();
539 
540 	lpr = DZ_LPR_RX_ENABLE | ((ispeed&0xF)<<8) | line;
541 
542 	switch (cflag & CSIZE)
543 	{
544 	  case CS5:
545 		lpr |= DZ_LPR_5_BIT_CHAR;
546 		break;
547 	  case CS6:
548 		lpr |= DZ_LPR_6_BIT_CHAR;
549 		break;
550 	  case CS7:
551 		lpr |= DZ_LPR_7_BIT_CHAR;
552 		break;
553 	  default:
554 		lpr |= DZ_LPR_8_BIT_CHAR;
555 		break;
556 	}
557 	if (cflag & PARENB)
558 		lpr |= DZ_LPR_PARENB;
559 	if (cflag & PARODD)
560 		lpr |= DZ_LPR_OPAR;
561 	if (cflag & CSTOPB)
562 		lpr |= DZ_LPR_2_STOP;
563 
564 	DZ_WRITE_WORD(dr_lpr, lpr);
565 
566 	(void) splx(s);
567 	return (0);
568 }
569 
570 static unsigned
571 dzmctl(struct dz_softc *sc, int line, int bits, int how)
572 {
573 	unsigned status;
574 	unsigned mbits;
575 	unsigned bit;
576 	int s;
577 
578 	s = spltty();
579 
580 	mbits = 0;
581 
582 	bit = (1 << line);
583 
584 	/* external signals as seen from the port */
585 
586 	status = DZ_READ_BYTE(dr_dcd) | sc->sc_dsr;
587 
588 	if (status & bit)
589 		mbits |= DML_DCD;
590 
591 	status = DZ_READ_BYTE(dr_ring);
592 
593 	if (status & bit)
594 		mbits |= DML_RI;
595 
596 	/* internal signals/state delivered to port */
597 
598 	status = DZ_READ_BYTE(dr_dtr);
599 
600 	if (status & bit)
601 		mbits |= DML_DTR;
602 
603 	if (sc->sc_brk & bit)
604 		mbits |= DML_BRK;
605 
606 	switch (how)
607 	{
608 	  case DMSET:
609 		mbits = bits;
610 		break;
611 
612 	  case DMBIS:
613 		mbits |= bits;
614 		break;
615 
616 	  case DMBIC:
617 		mbits &= ~bits;
618 		break;
619 
620 	  case DMGET:
621 		(void) splx(s);
622 		return (mbits);
623 	}
624 
625 	if (mbits & DML_DTR) {
626 		DZ_WRITE_BYTE(dr_dtr, DZ_READ_BYTE(dr_dtr) | bit);
627 	} else {
628 		DZ_WRITE_BYTE(dr_dtr, DZ_READ_BYTE(dr_dtr) & ~bit);
629 	}
630 
631 	if (mbits & DML_BRK) {
632 		sc->sc_brk |= bit;
633 		DZ_WRITE_BYTE(dr_break, sc->sc_brk);
634 	} else {
635 		sc->sc_brk &= ~bit;
636 		DZ_WRITE_BYTE(dr_break, sc->sc_brk);
637 	}
638 
639 	(void) splx(s);
640 	return (mbits);
641 }
642 
643 /*
644  * This is called by timeout() periodically.
645  * Check to see if modem status bits have changed.
646  */
647 static void
648 dzscan(void *arg)
649 {
650 	struct dz_softc *sc;
651 	struct tty *tp;
652 	int n, bit, port;
653 	unsigned csr;
654 	int s;
655 
656 	s = spltty();
657 
658 	for (n = 0; n < dz_cd.cd_ndevs; n++) {
659 
660 		if (dz_cd.cd_devs[n] == NULL)
661 			continue;
662 
663 		sc = dz_cd.cd_devs[n];
664 
665 		for (port = 0; port < sc->sc_type; port++) {
666 
667 			tp = sc->sc_dz[port].dz_tty;
668 			bit = (1 << port);
669 
670 			if ((DZ_READ_BYTE(dr_dcd) | sc->sc_dsr) & bit) {
671 				if (!(tp->t_state & TS_CARR_ON))
672 					(*tp->t_linesw->l_modem) (tp, 1);
673 			} else if ((tp->t_state & TS_CARR_ON) &&
674 			    (*tp->t_linesw->l_modem)(tp, 0) == 0) {
675 				DZ_WRITE_BYTE(dr_tcr,
676 				    (DZ_READ_WORD(dr_tcrw) & 255) & ~bit);
677 			}
678 	    	}
679 
680 		/*
681 		 *  If the RX interrupt rate is this high, switch
682 		 *  the controller to Silo Alarm - which means don't
683 	 	 *  interrupt until the RX silo has 16 characters in
684 	 	 *  it (the silo is 64 characters in all).
685 		 *  Avoid oscillating SA on and off by not turning
686 		 *  if off unless the rate is appropriately low.
687 		 */
688 
689 		csr = DZ_READ_WORD(dr_csr);
690 
691 		if (sc->sc_rxint > (16*10)) {
692 			if ((csr & DZ_CSR_SAE) == 0)
693 				DZ_WRITE_WORD(dr_csr, csr | DZ_CSR_SAE);
694 	    	} else if ((csr & DZ_CSR_SAE) != 0)
695 			if (sc->sc_rxint < 10)
696 				DZ_WRITE_WORD(dr_csr, csr & ~(DZ_CSR_SAE));
697 
698 		sc->sc_rxint = 0;
699 	}
700 	(void) splx(s);
701 	callout_reset(&dzscan_ch, hz, dzscan, NULL);
702 	return;
703 }
704 
705 /*
706  * Called after an ubareset. The DZ card is reset, but the only thing
707  * that must be done is to start the receiver and transmitter again.
708  * No DMA setup to care about.
709  */
710 void
711 dzreset(struct device *dev)
712 {
713 	struct dz_softc *sc = (void *)dev;
714 	struct tty *tp;
715 	int i;
716 
717 	for (i = 0; i < sc->sc_type; i++) {
718 		tp = sc->sc_dz[i].dz_tty;
719 
720 		if (((tp->t_state & TS_ISOPEN) == 0) || (tp->t_wopen == 0))
721 			continue;
722 
723 		dzparam(tp, &tp->t_termios);
724 		dzmctl(sc, i, DML_DTR, DMSET);
725 		tp->t_state &= ~TS_BUSY;
726 		dzstart(tp);	/* Kick off transmitter again */
727 	}
728 }
729