xref: /netbsd/sys/dev/ic/cy.c (revision c4a72b64)
1 /*	$NetBSD: cy.c,v 1.28 2002/10/23 09:13:16 jdolecek Exp $	*/
2 
3 /*
4  * cy.c
5  *
6  * Driver for Cyclades Cyclom-8/16/32 multiport serial cards
7  * (currently not tested with Cyclom-32 cards)
8  *
9  * Timo Rossi, 1996
10  *
11  * Supports both ISA and PCI Cyclom cards
12  *
13  * Lots of debug output can be enabled by defining CY_DEBUG
14  * Some debugging counters (number of receive/transmit interrupts etc.)
15  * can be enabled by defining CY_DEBUG1
16  */
17 
18 #include <sys/cdefs.h>
19 __KERNEL_RCSID(0, "$NetBSD: cy.c,v 1.28 2002/10/23 09:13:16 jdolecek Exp $");
20 
21 #include <sys/param.h>
22 #include <sys/ioctl.h>
23 #include <sys/syslog.h>
24 #include <sys/fcntl.h>
25 #include <sys/tty.h>
26 #include <sys/proc.h>
27 #include <sys/conf.h>
28 #include <sys/user.h>
29 #include <sys/ioctl.h>
30 #include <sys/select.h>
31 #include <sys/device.h>
32 #include <sys/malloc.h>
33 #include <sys/systm.h>
34 #include <sys/callout.h>
35 
36 #include <machine/bus.h>
37 
38 #include <dev/ic/cd1400reg.h>
39 #include <dev/ic/cyreg.h>
40 #include <dev/ic/cyvar.h>
41 
42 /* Macros to clear/set/test flags. */
43 #define	SET(t, f)	(t) |= (f)
44 #define	CLR(t, f)	(t) &= ~(f)
45 #define	ISSET(t, f)	((t) & (f))
46 
47 int	cyparam(struct tty *, struct termios *);
48 void	cystart(struct tty *);
49 void	cy_poll(void *);
50 int	cy_modem_control(struct cy_softc *, struct cy_port *, int, int);
51 void	cy_enable_transmitter(struct cy_softc *, struct cy_port *);
52 void	cd1400_channel_cmd(struct cy_softc *, struct cy_port *, int);
53 int	cy_speed(speed_t, int *, int *, int);
54 
55 extern struct cfdriver cy_cd;
56 
57 dev_type_open(cyopen);
58 dev_type_close(cyclose);
59 dev_type_read(cyread);
60 dev_type_write(cywrite);
61 dev_type_ioctl(cyioctl);
62 dev_type_stop(cystop);
63 dev_type_tty(cytty);
64 dev_type_poll(cypoll);
65 
66 const struct cdevsw cy_cdevsw = {
67 	cyopen, cyclose, cyread, cywrite, cyioctl,
68 	cystop, cytty, cypoll, nommap, ttykqfilter, D_TTY
69 };
70 
71 static int      cy_open = 0;
72 static int      cy_events = 0;
73 
74 int	cy_attached_ttys;
75 
76 struct callout cy_poll_callout = CALLOUT_INITIALIZER;
77 
78 /*
79  * Common probe routine
80  */
81 int
82 cy_find(struct cy_softc *sc)
83 {
84 	int cy_chip, chip;
85 	u_char firmware_ver;
86 	bus_space_tag_t tag = sc->sc_memt;
87 	bus_space_handle_t bsh = sc->sc_bsh;
88 	int bustype = sc->sc_bustype;
89 
90 	/* Cyclom card hardware reset */
91 	bus_space_write_1(tag, bsh, CY16_RESET << bustype, 0);
92 	DELAY(500);		/* wait for reset to complete */
93 	bus_space_write_1(tag, bsh, CY_CLEAR_INTR << bustype, 0);
94 
95 #ifdef CY_DEBUG
96 	printf("cy: card reset done\n");
97 #endif
98 	sc->sc_nchips = 0;
99 
100 	for (cy_chip = 0, chip = 0; cy_chip < CY_MAX_CD1400s;
101 	    cy_chip++, chip += (CY_CD1400_MEMSPACING << bustype)) {
102 		int i;
103 
104 		/*
105 		 * the last 4 nchips are 'interleaved' with the first 4 on
106 		 * 32-port boards
107 		 */
108 		if (cy_chip == 4)
109 			chip -= (CY32_ADDR_FIX << bustype);
110 
111 #ifdef CY_DEBUG
112 		printf("%s probe chip %d offset 0x%x ... ",
113 		    sc->sc_dev.dv_xname, cy_chip, chip);
114 #endif
115 
116 		/* wait until the chip is ready for command */
117 		DELAY(1000);
118 		if (bus_space_read_1(tag, bsh, chip +
119 		    ((CD1400_CCR << 1) << bustype)) != 0) {
120 #ifdef CY_DEBUG
121 			printf("not ready for command\n");
122 #endif
123 			break;
124 		}
125 		/* clear the firmware version reg. */
126 		bus_space_write_1(tag, bsh, chip +
127 		    ((CD1400_GFRCR << 1) << bustype), 0);
128 
129 		/*
130 	         * On Cyclom-16 references to non-existent chip 4
131 	         * actually access chip 0 (address line 9 not decoded).
132 	         * Here we check if the clearing of chip 4 GFRCR actually
133 	         * cleared chip 0 GFRCR. In that case we have a 16 port card.
134 	         */
135 		if (cy_chip == 4 &&
136 		    bus_space_read_1(tag, bsh, /* off for chip 0 (0) + */
137 		       ((CD1400_GFRCR << 1) << bustype)) == 0)
138 			break;
139 
140 		/* reset the chip */
141 		bus_space_write_1(tag, bsh, chip +
142 		    ((CD1400_CCR << 1) << bustype),
143 		    CD1400_CCR_CMDRESET | CD1400_CCR_FULLRESET);
144 
145 		/* wait for the chip to initialize itself */
146 		for (i = 0; i < 200; i++) {
147 			DELAY(50);
148 			firmware_ver = bus_space_read_1(tag, bsh, chip +
149 			    ((CD1400_GFRCR << 1) << bustype));
150 			if ((firmware_ver & 0xf0) == 0x40) /* found a CD1400 */
151 				break;
152 		}
153 #ifdef CY_DEBUG
154 		printf("firmware version 0x%x\n", firmware_ver);
155 #endif
156 
157 		if ((firmware_ver & 0xf0) != 0x40)
158 			break;
159 
160 		/* firmware version OK, CD1400 found */
161 		sc->sc_nchips++;
162 	}
163 
164 	if (sc->sc_nchips == 0) {
165 #ifdef CY_DEBUG
166 		printf("no CD1400s found\n");
167 #endif
168 		return 0;
169 	}
170 #ifdef CY_DEBUG
171 	printf("found %d CD1400s\n", sc->sc_nchips);
172 #endif
173 
174 	return 1;
175 }
176 
177 void
178 cy_attach(struct cy_softc *sc)
179 {
180 	int port, cy_chip, num_chips, cdu, chip;
181 	int cy_clock;
182 
183 	num_chips = sc->sc_nchips;
184 	if (num_chips == 0)
185 		return;
186 
187 	memset(sc->sc_ports, 0, sizeof(sc->sc_ports));
188 
189 	port = 0;
190 	for (cy_chip = 0, chip = 0; cy_chip < num_chips; cy_chip++,
191 	    chip += (CY_CD1400_MEMSPACING << sc->sc_bustype)) {
192 
193 		if (cy_chip == 4)
194 			chip -= (CY32_ADDR_FIX << sc->sc_bustype);
195 
196 #ifdef CY_DEBUG
197 		printf("attach CD1400 #%d offset 0x%x\n", cy_chip, chip);
198 #endif
199 		sc->sc_cd1400_offs[cy_chip] = chip;
200 
201 		/*
202 		 * configure port 0 as serial port (should already be after
203 		 * reset)
204 		 */
205 		cd_write_reg(sc, cy_chip, CD1400_GCR, 0);
206 
207 		if (cd_read_reg(sc, cy_chip, CD1400_GFRCR) <= 0x46)
208 			cy_clock = CY_CLOCK;
209 		else
210 			cy_clock = CY_CLOCK_60;
211 
212 		/* set up a receive timeout period (1ms) */
213 		cd_write_reg(sc, cy_chip, CD1400_PPR,
214 		    (cy_clock / CD1400_PPR_PRESCALER / 1000) + 1);
215 
216 		for (cdu = 0; cdu < CD1400_NO_OF_CHANNELS; cdu++) {
217 			sc->sc_ports[port].cy_softc = sc;
218 			sc->sc_ports[port].cy_port_num = port;
219 			sc->sc_ports[port].cy_chip = cy_chip;
220 			sc->sc_ports[port].cy_clock = cy_clock;
221 
222 			/* should we initialize anything else here? */
223 			port++;
224 		} /* for(each port on one CD1400...) */
225 
226 	} /* for(each CD1400 on a card... ) */
227 
228 	sc->sc_nchannels = port;
229 
230 	printf("%s: %d channels (ttyCY%03d..ttyCY%03d)\n",
231 	    sc->sc_dev.dv_xname, sc->sc_nchannels, cy_attached_ttys,
232 	    cy_attached_ttys + (sc->sc_nchannels - 1));
233 
234 	cy_attached_ttys += sc->sc_nchannels;
235 
236 	/* ensure an edge for the next interrupt */
237 	bus_space_write_1(sc->sc_memt, sc->sc_bsh,
238 	    CY_CLEAR_INTR << sc->sc_bustype, 0);
239 }
240 
241 #define	CYDIALOUT_MASK		0x80000
242 #define	CY_DIALOUT(dev)		(minor(dev) & CYDIALOUT_MASK)
243 
244 #define	CY_PORT(dev)		cy_getport((dev))
245 #define	CY_BOARD(cy)		((cy)->cy_softc)
246 
247 static struct cy_port *
248 cy_getport(dev_t dev)
249 {
250 	int i, j, k, u = minor(dev) & ~CYDIALOUT_MASK;
251 	struct cy_softc *sc;
252 
253 	for (i = 0, j = 0; i < cy_cd.cd_ndevs; i++) {
254 		k = j;
255 		sc = device_lookup(&cy_cd, i);
256 		if (sc == NULL)
257 			continue;
258 		if (sc->sc_nchannels == 0)
259 			continue;
260 		j += sc->sc_nchannels;
261 		if (j > u)
262 			break;
263 	}
264 
265 	if (i == cy_cd.cd_ndevs)
266 		return (NULL);
267 	else
268 		return (&sc->sc_ports[u - k]);
269 }
270 
271 /*
272  * open routine. returns zero if successfull, else error code
273  */
274 int
275 cyopen(dev_t dev, int flag, int mode, struct proc *p)
276 {
277 	struct cy_softc *sc;
278 	struct cy_port *cy;
279 	struct tty *tp;
280 	int s, error;
281 
282 	cy = CY_PORT(dev);
283 	if (cy == NULL)
284 		return (ENXIO);
285 	sc = CY_BOARD(cy);
286 
287 	s = spltty();
288 	if (cy->cy_tty == NULL) {
289 		if ((cy->cy_tty = ttymalloc()) == NULL) {
290 			splx(s);
291 			printf("%s: port %d: can't allocate tty\n",
292 			    sc->sc_dev.dv_xname, cy->cy_port_num);
293 			return (ENOMEM);
294 		}
295 		tty_attach(cy->cy_tty);
296 	}
297 	splx(s);
298 
299 	tp = cy->cy_tty;
300 	tp->t_oproc = cystart;
301 	tp->t_param = cyparam;
302 	tp->t_dev = dev;
303 
304 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
305 		ttychars(tp);
306 		tp->t_iflag = TTYDEF_IFLAG;
307 		tp->t_oflag = TTYDEF_OFLAG;
308 		tp->t_cflag = TTYDEF_CFLAG;
309 		if (ISSET(cy->cy_openflags, TIOCFLAG_CLOCAL))
310 			SET(tp->t_cflag, CLOCAL);
311 		if (ISSET(cy->cy_openflags, TIOCFLAG_CRTSCTS))
312 			SET(tp->t_cflag, CRTSCTS);
313 		if (ISSET(cy->cy_openflags, TIOCFLAG_MDMBUF))
314 			SET(tp->t_cflag, MDMBUF);
315 		tp->t_lflag = TTYDEF_LFLAG;
316 		tp->t_ispeed = tp->t_ospeed = TTYDEF_SPEED;
317 
318 		s = spltty();
319 
320 		/*
321 		 * Allocate input ring buffer if we don't already have one
322 		 */
323 		if (cy->cy_ibuf == NULL) {
324 			cy->cy_ibuf = malloc(CY_IBUF_SIZE, M_DEVBUF, M_NOWAIT);
325 			if (cy->cy_ibuf == NULL) {
326 				printf("%s: port %d: can't allocate input buffer\n",
327 				       sc->sc_dev.dv_xname, cy->cy_port_num);
328 				splx(s);
329 				return ENOMEM;
330 			}
331 			cy->cy_ibuf_end = cy->cy_ibuf + CY_IBUF_SIZE;
332 		}
333 		/* mark the ring buffer as empty */
334 		cy->cy_ibuf_rd_ptr = cy->cy_ibuf_wr_ptr = cy->cy_ibuf;
335 
336 		/* select CD1400 channel */
337 		cd_write_reg(sc, cy->cy_chip, CD1400_CAR,
338 		    cy->cy_port_num & CD1400_CAR_CHAN);
339 		/* reset the channel */
340 		cd1400_channel_cmd(sc, cy, CD1400_CCR_CMDRESET);
341 		/* encode unit (port) number in LIVR */
342 		/* there is just enough space for 5 bits (32 ports) */
343 		cd_write_reg(sc, cy->cy_chip, CD1400_LIVR,
344 		    cy->cy_port_num << 3);
345 
346 		cy->cy_channel_control = 0;
347 
348 		/* hmm... need spltty() here? */
349 		if (cy_open == 0) {
350 			cy_open = 1;
351 			callout_reset(&cy_poll_callout, 1, cy_poll, NULL);
352 		}
353 		/* this sets parameters and raises DTR */
354 		cyparam(tp, &tp->t_termios);
355 
356 		ttsetwater(tp);
357 
358 		/* raise RTS too */
359 		cy_modem_control(sc, cy, TIOCM_RTS, DMBIS);
360 
361 		cy->cy_carrier_stat =
362 			cd_read_reg(sc, cy->cy_chip, CD1400_MSVR2);
363 
364 		/* enable receiver and modem change interrupts */
365 		cd_write_reg(sc, cy->cy_chip, CD1400_SRER,
366 		    CD1400_SRER_MDMCH | CD1400_SRER_RXDATA);
367 
368 		if (CY_DIALOUT(dev) ||
369 		    ISSET(cy->cy_openflags, TIOCFLAG_SOFTCAR) ||
370 		    ISSET(tp->t_cflag, MDMBUF) ||
371 		    ISSET(cy->cy_carrier_stat, CD1400_MSVR2_CD))
372 			SET(tp->t_state, TS_CARR_ON);
373 		else
374 			CLR(tp->t_state, TS_CARR_ON);
375 	} else if (ISSET(tp->t_state, TS_XCLUDE) && p->p_ucred->cr_uid != 0) {
376 		return EBUSY;
377 	} else {
378 		s = spltty();
379 	}
380 
381 	/* wait for carrier if necessary */
382 	if (!ISSET(flag, O_NONBLOCK)) {
383 		while (!ISSET(tp->t_cflag, CLOCAL) &&
384 		    !ISSET(tp->t_state, TS_CARR_ON)) {
385 			tp->t_wopen++;
386 			error = ttysleep(tp, &tp->t_rawq, TTIPRI | PCATCH,
387 			    "cydcd", 0);
388 			tp->t_wopen--;
389 			if (error != 0) {
390 				splx(s);
391 				return error;
392 			}
393 		}
394 	}
395 	splx(s);
396 
397 	return (*tp->t_linesw->l_open) (dev, tp);
398 }
399 
400 /*
401  * close routine. returns zero if successfull, else error code
402  */
403 int
404 cyclose(dev_t dev, int flag, int mode, struct proc *p)
405 {
406 	struct cy_softc *sc;
407 	struct cy_port *cy;
408 	struct tty *tp;
409 	int s;
410 
411 	cy = CY_PORT(dev);
412 	sc = CY_BOARD(cy);
413 	tp = cy->cy_tty;
414 
415 	(*tp->t_linesw->l_close) (tp, flag);
416 	s = spltty();
417 
418 	if (ISSET(tp->t_cflag, HUPCL) &&
419 	    !ISSET(cy->cy_openflags, TIOCFLAG_SOFTCAR)) {
420 		/*
421 		 * drop DTR and RTS (should we wait for output buffer to
422 		 * become empty first?)
423 		 */
424 		cy_modem_control(sc, cy, 0, DMSET);
425 	}
426 	/*
427 	 * XXX should we disable modem change and
428 	 * receive interrupts here or somewhere ?
429 	 */
430 	CLR(tp->t_state, TS_BUSY | TS_FLUSH);
431 
432 	splx(s);
433 	ttyclose(tp);
434 
435 	return 0;
436 }
437 
438 /*
439  * Read routine
440  */
441 int
442 cyread(dev_t dev, struct uio *uio, int flag)
443 {
444 	struct cy_port *cy;
445 	struct tty *tp;
446 
447 	cy = CY_PORT(dev);
448 	tp = cy->cy_tty;
449 
450 	return ((*tp->t_linesw->l_read)(tp, uio, flag));
451 }
452 
453 /*
454  * Write routine
455  */
456 int
457 cywrite(dev_t dev, struct uio *uio, int flag)
458 {
459 	struct cy_port *cy;
460 	struct tty *tp;
461 
462 	cy = CY_PORT(dev);
463 	tp = cy->cy_tty;
464 
465 	return ((*tp->t_linesw->l_write)(tp, uio, flag));
466 }
467 
468 /*
469  * Poll routine
470  */
471 int
472 cypoll(dev, events, p)
473 	dev_t dev;
474 	int events;
475 	struct proc *p;
476 {
477 	struct cy_port *cy;
478 	struct tty *tp;
479 
480 	cy = CY_PORT(dev);
481 	tp = cy->cy_tty;
482 
483 	return ((*tp->t_linesw->l_poll)(tp, events, p));
484 }
485 
486 /*
487  * return tty pointer
488  */
489 struct tty *
490 cytty(dev_t dev)
491 {
492 	struct cy_port *cy;
493 
494 	cy = CY_PORT(dev);
495 
496 	return (cy->cy_tty);
497 }
498 
499 /*
500  * ioctl routine
501  */
502 int
503 cyioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct proc *p)
504 {
505 	struct cy_softc *sc;
506 	struct cy_port *cy;
507 	struct tty *tp;
508 	int error;
509 
510 	cy = CY_PORT(dev);
511 	sc = CY_BOARD(cy);
512 	tp = cy->cy_tty;
513 
514 	error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, p);
515 	if (error != EPASSTHROUGH)
516 		return error;
517 
518 	error = ttioctl(tp, cmd, data, flag, p);
519 	if (error != EPASSTHROUGH)
520 		return error;
521 
522 	/* XXX should not allow dropping DTR when dialin? */
523 
524 	switch (cmd) {
525 	case TIOCSBRK:		/* start break */
526 		SET(cy->cy_flags, CY_F_START_BREAK);
527 		cy_enable_transmitter(sc, cy);
528 		break;
529 
530 	case TIOCCBRK:		/* stop break */
531 		SET(cy->cy_flags, CY_F_END_BREAK);
532 		cy_enable_transmitter(sc, cy);
533 		break;
534 
535 	case TIOCSDTR:		/* DTR on */
536 		cy_modem_control(sc, cy, TIOCM_DTR, DMBIS);
537 		break;
538 
539 	case TIOCCDTR:		/* DTR off */
540 		cy_modem_control(sc, cy, TIOCM_DTR, DMBIC);
541 		break;
542 
543 	case TIOCMSET:		/* set new modem control line values */
544 		cy_modem_control(sc, cy, *((int *) data), DMSET);
545 		break;
546 
547 	case TIOCMBIS:		/* turn modem control bits on */
548 		cy_modem_control(sc, cy, *((int *) data), DMBIS);
549 		break;
550 
551 	case TIOCMBIC:		/* turn modem control bits off */
552 		cy_modem_control(sc, cy, *((int *) data), DMBIC);
553 		break;
554 
555 	case TIOCMGET:		/* get modem control/status line state */
556 		*((int *) data) = cy_modem_control(sc, cy, 0, DMGET);
557 		break;
558 
559 	case TIOCGFLAGS:
560 		*((int *) data) = cy->cy_openflags |
561 			(CY_DIALOUT(dev) ? TIOCFLAG_SOFTCAR : 0);
562 		break;
563 
564 	case TIOCSFLAGS:
565 		error = suser(p->p_ucred, &p->p_acflag);
566 		if (error != 0)
567 			return EPERM;
568 
569 		cy->cy_openflags = *((int *) data) &
570 		    (TIOCFLAG_SOFTCAR | TIOCFLAG_CLOCAL |
571 		     TIOCFLAG_CRTSCTS | TIOCFLAG_MDMBUF);
572 		break;
573 
574 	default:
575 		return EPASSTHROUGH;
576 	}
577 
578 	return 0;
579 }
580 
581 /*
582  * start output
583  */
584 void
585 cystart(struct tty *tp)
586 {
587 	struct cy_softc *sc;
588 	struct cy_port *cy;
589 	int s;
590 
591 	cy = CY_PORT(tp->t_dev);
592 	sc = cy->cy_softc;
593 
594 	s = spltty();
595 
596 #ifdef CY_DEBUG1
597 	cy->cy_start_count++;
598 #endif
599 
600 	if (!ISSET(tp->t_state, TS_TTSTOP | TS_TIMEOUT | TS_BUSY)) {
601 		if (tp->t_outq.c_cc <= tp->t_lowat) {
602 			if (ISSET(tp->t_state, TS_ASLEEP)) {
603 				CLR(tp->t_state, TS_ASLEEP);
604 				wakeup(&tp->t_outq);
605 			}
606 			selwakeup(&tp->t_wsel);
607 
608 			if (tp->t_outq.c_cc == 0)
609 				goto out;
610 		}
611 		SET(tp->t_state, TS_BUSY);
612 		cy_enable_transmitter(sc, cy);
613 	}
614 out:
615 
616 	splx(s);
617 }
618 
619 /*
620  * stop output
621  */
622 void
623 cystop(struct tty *tp, int flag)
624 {
625 	struct cy_port *cy;
626 	int s;
627 
628 	cy = CY_PORT(tp->t_dev);
629 
630 	s = spltty();
631 	if (ISSET(tp->t_state, TS_BUSY)) {
632 		if (!ISSET(tp->t_state, TS_TTSTOP))
633 			SET(tp->t_state, TS_FLUSH);
634 
635 		/*
636 		 * the transmit interrupt routine will disable transmit when it
637 		 * notices that CY_F_STOP has been set.
638 		 */
639 		SET(cy->cy_flags, CY_F_STOP);
640 	}
641 	splx(s);
642 }
643 
644 /*
645  * parameter setting routine.
646  * returns 0 if successfull, else returns error code
647  */
648 int
649 cyparam(struct tty *tp, struct termios *t)
650 {
651 	struct cy_softc *sc;
652 	struct cy_port *cy;
653 	int ibpr, obpr, i_clk_opt, o_clk_opt, s, opt;
654 
655 	cy = CY_PORT(tp->t_dev);
656 	sc = CY_BOARD(cy);
657 
658 	if (t->c_ospeed != 0 && cy_speed(t->c_ospeed, &o_clk_opt, &obpr, cy->cy_clock) < 0)
659 		return EINVAL;
660 
661 	if (t->c_ispeed != 0 && cy_speed(t->c_ispeed, &i_clk_opt, &ibpr, cy->cy_clock) < 0)
662 		return EINVAL;
663 
664 	s = spltty();
665 
666 	/* hang up the line is ospeed is zero, else turn DTR on */
667 	cy_modem_control(sc, cy, TIOCM_DTR, (t->c_ospeed == 0 ? DMBIC : DMBIS));
668 
669 	/* channel was selected by the above call to cy_modem_control() */
670 #if 0
671 	cd_write_reg(sc, cy->cy_chip, CD1400_CAR, port & CD1400_CAR_CHAN);
672 #endif
673 
674 	/* set transmit speed */
675 	if (t->c_ospeed != 0) {
676 		cd_write_reg(sc, cy->cy_chip, CD1400_TCOR, o_clk_opt);
677 		cd_write_reg(sc, cy->cy_chip, CD1400_TBPR, obpr);
678 	}
679 	/* set receive speed */
680 	if (t->c_ispeed != 0) {
681 		cd_write_reg(sc, cy->cy_chip, CD1400_RCOR, i_clk_opt);
682 		cd_write_reg(sc, cy->cy_chip, CD1400_RBPR, ibpr);
683 	}
684 	opt = CD1400_CCR_CMDCHANCTL | CD1400_CCR_XMTEN
685 		| (ISSET(t->c_cflag, CREAD) ? CD1400_CCR_RCVEN : CD1400_CCR_RCVDIS);
686 
687 	if (opt != cy->cy_channel_control) {
688 		cy->cy_channel_control = opt;
689 		cd1400_channel_cmd(sc, cy, opt);
690 	}
691 	/* compute COR1 contents */
692 	opt = 0;
693 	if (ISSET(t->c_cflag, PARENB)) {
694 		if (ISSET(t->c_cflag, PARODD))
695 			opt |= CD1400_COR1_PARODD;
696 		opt |= CD1400_COR1_PARNORMAL;
697 	}
698 	if (!ISSET(t->c_iflag, INPCK))
699 		opt |= CD1400_COR1_NOINPCK;	/* no parity checking */
700 
701 	if (ISSET(t->c_cflag, CSTOPB))
702 		opt |= CD1400_COR1_STOP2;
703 
704 	switch (t->c_cflag & CSIZE) {
705 	case CS5:
706 		opt |= CD1400_COR1_CS5;
707 		break;
708 
709 	case CS6:
710 		opt |= CD1400_COR1_CS6;
711 		break;
712 
713 	case CS7:
714 		opt |= CD1400_COR1_CS7;
715 		break;
716 
717 	default:
718 		opt |= CD1400_COR1_CS8;
719 		break;
720 	}
721 
722 	cd_write_reg(sc, cy->cy_chip, CD1400_COR1, opt);
723 
724 #ifdef CY_DEBUG
725 	printf("cor1 = 0x%x...", opt);
726 #endif
727 
728 	/*
729 	 * use the CD1400 automatic CTS flow control if CRTSCTS is set
730 	 *
731 	 * CD1400_COR2_ETC is used because breaks are generated with
732 	 * embedded transmit commands
733 	 */
734 	cd_write_reg(sc, cy->cy_chip, CD1400_COR2,
735 		     CD1400_COR2_ETC |
736 		 (ISSET(t->c_cflag, CRTSCTS) ? CD1400_COR2_CCTS_OFLOW : 0));
737 
738 	cd_write_reg(sc, cy->cy_chip, CD1400_COR3, CY_RX_FIFO_THRESHOLD);
739 
740 	cd1400_channel_cmd(sc, cy, CD1400_CCR_CMDCORCHG |
741 	    CD1400_CCR_COR1 | CD1400_CCR_COR2 | CD1400_CCR_COR3);
742 
743 	cd_write_reg(sc, cy->cy_chip, CD1400_COR4, CD1400_COR4_PFO_EXCEPTION);
744 	cd_write_reg(sc, cy->cy_chip, CD1400_COR5, 0);
745 
746 	/*
747          * set modem change option registers to generate interrupts
748          * on carrier detect changes.
749          *
750          * if hardware RTS handshaking is used
751          * also set the handshaking threshold.
752          */
753 	if (cy->cy_clock == CY_CLOCK_60) {
754 	   cd_write_reg(sc, cy->cy_chip, CD1400_MCOR1, CD1400_MCOR1_CDzd |
755     	      (ISSET(t->c_cflag, CRTSCTS) ? CY_RX_DTR_THRESHOLD : 0));
756 	} else {
757 	   cd_write_reg(sc, cy->cy_chip, CD1400_MCOR1, CD1400_MCOR1_CDzd);
758 	}
759 
760 	cd_write_reg(sc, cy->cy_chip, CD1400_MCOR2, CD1400_MCOR2_CDod);
761 
762 	/*
763          * set receive timeout to approx. 2ms
764          * could use more complex logic here...
765          * (but is it actually needed or even useful?)
766          */
767 	cd_write_reg(sc, cy->cy_chip, CD1400_RTPR, 2);
768 
769 	/*
770          * should do anything else here?
771          * XXX check MDMBUF handshaking like in com.c?
772          */
773 
774 	splx(s);
775 	return 0;
776 }
777 
778 /*
779  * set/get modem line status
780  *
781  * bits can be: TIOCM_DTR, TIOCM_RTS, TIOCM_CTS, TIOCM_CD, TIOCM_RI, TIOCM_DSR
782  */
783 int
784 cy_modem_control(struct cy_softc *sc, struct cy_port *cy, int bits, int howto)
785 {
786 	struct tty *tp = cy->cy_tty;
787 	int s, msvr;
788 
789 	s = spltty();
790 
791 	/* select channel */
792 	cd_write_reg(sc, cy->cy_chip, CD1400_CAR,
793 	    cy->cy_port_num & CD1400_CAR_CHAN);
794 
795 	/* Does not manipulate RTS if it is used for flow control. */
796 	switch (howto) {
797 	case DMGET:
798 		bits = 0;
799 		if (cy->cy_channel_control & CD1400_CCR_RCVEN)
800 			bits |= TIOCM_LE;
801 		msvr = cd_read_reg(sc, cy->cy_chip, CD1400_MSVR2);
802 		if (cy->cy_clock == CY_CLOCK_60) {
803 			if (cd_read_reg(sc, cy->cy_chip, CD1400_MSVR1) &
804 		    		CD1400_MSVR1_RTS)
805 				bits |= TIOCM_DTR;
806 			if (msvr & CD1400_MSVR2_DTR)
807 				bits |= TIOCM_RTS;
808 		} else {
809 			if (cd_read_reg(sc, cy->cy_chip, CD1400_MSVR1) &
810 			    CD1400_MSVR1_RTS)
811 				bits |= TIOCM_RTS;
812 			if (msvr & CD1400_MSVR2_DTR)
813 				bits |= TIOCM_DTR;
814 		}
815 		if (msvr & CD1400_MSVR2_CTS)
816 			bits |= TIOCM_CTS;
817 		if (msvr & CD1400_MSVR2_CD)
818 			bits |= TIOCM_CD;
819 		/* Not connected on some Cyclom-Y boards? */
820 		if (msvr & CD1400_MSVR2_DSR)
821 			bits |= TIOCM_DSR;
822 		/* Not connected on some Cyclom-8Y boards? */
823 		if (msvr & CD1400_MSVR2_RI)
824 			bits |= TIOCM_RI;
825 		break;
826 
827 	case DMSET:		/* replace old values with new ones */
828 		if (cy->cy_clock == CY_CLOCK_60) {
829 			if (!ISSET(tp->t_cflag, CRTSCTS))
830 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR2,
831 				   ((bits & TIOCM_RTS) ? CD1400_MSVR2_DTR : 0));
832 			cd_write_reg(sc, cy->cy_chip, CD1400_MSVR1,
833 			    ((bits & TIOCM_DTR) ? CD1400_MSVR1_RTS : 0));
834 		} else {
835 			if (!ISSET(tp->t_cflag, CRTSCTS))
836 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR1,
837 				   ((bits & TIOCM_RTS) ? CD1400_MSVR1_RTS : 0));
838 			cd_write_reg(sc, cy->cy_chip, CD1400_MSVR2,
839 			    ((bits & TIOCM_DTR) ? CD1400_MSVR2_DTR : 0));
840 		}
841 		break;
842 
843 	case DMBIS:		/* set bits */
844 		if (cy->cy_clock == CY_CLOCK_60) {
845 			if (!ISSET(tp->t_cflag, CRTSCTS) &&
846 			    (bits & TIOCM_RTS) != 0)
847 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR2,
848 				    CD1400_MSVR2_DTR);
849 			if (bits & TIOCM_DTR)
850 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR1,
851 				    CD1400_MSVR1_RTS);
852 		} else {
853 			if (!ISSET(tp->t_cflag, CRTSCTS) &&
854 			    (bits & TIOCM_RTS) != 0)
855 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR1,
856 				    CD1400_MSVR1_RTS);
857 			if (bits & TIOCM_DTR)
858 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR2,
859 				    CD1400_MSVR2_DTR);
860 		}
861 		break;
862 
863 	case DMBIC:		/* clear bits */
864 		if (cy->cy_clock == CY_CLOCK_60) {
865 			if (!ISSET(tp->t_cflag, CRTSCTS) && (bits & TIOCM_RTS))
866 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR2, 0);
867 			if (bits & TIOCM_DTR)
868 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR1, 0);
869 		} else {
870 			if (!ISSET(tp->t_cflag, CRTSCTS) && (bits & TIOCM_RTS))
871 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR1, 0);
872 			if (bits & TIOCM_DTR)
873 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR2, 0);
874 		}
875 		break;
876 	}
877 	splx(s);
878 	return ((howto == DMGET) ? bits : 0);
879 }
880 
881 /*
882  * Upper-level handler loop (called from timer interrupt?)
883  * This routine is common for multiple cards
884  */
885 void
886 cy_poll(void *arg)
887 {
888 	int card, port;
889 	struct cy_softc *sc;
890 	struct cy_port *cy;
891 	struct tty *tp;
892 	static int counter = 0;
893 #ifdef CY_DEBUG1
894 	int did_something;
895 #endif
896 	int s = spltty();
897 
898 	if (cy_events == 0 && ++counter < 200) {
899 		splx(s);
900 		goto out;
901 	}
902 	cy_events = 0;
903 	splx(s);
904 
905 	for (card = 0; card < cy_cd.cd_ndevs; card++) {
906 		sc = device_lookup(&cy_cd, card);
907 		if (sc == NULL)
908 			continue;
909 
910 #ifdef CY_DEBUG1
911 		sc->sc_poll_count1++;
912 		did_something = 0;
913 #endif
914 
915 		for (port = 0; port < sc->sc_nchannels; port++) {
916 			cy = &sc->sc_ports[port];
917 			if ((tp = cy->cy_tty) == NULL || cy->cy_ibuf == NULL ||
918 			    (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0))
919 				continue;
920 
921 			/*
922 		         * handle received data
923 		         */
924 			while (cy->cy_ibuf_rd_ptr != cy->cy_ibuf_wr_ptr) {
925 				u_char line_stat;
926 				int chr;
927 
928 				line_stat = cy->cy_ibuf_rd_ptr[0];
929 				chr = cy->cy_ibuf_rd_ptr[1];
930 
931 				if (line_stat &
932 				    (CD1400_RDSR_BREAK | CD1400_RDSR_FE))
933 					chr |= TTY_FE;
934 				if (line_stat & CD1400_RDSR_PE)
935 					chr |= TTY_PE;
936 
937 				/*
938 				 * on an overrun error the data is treated as
939 				 * good just as it should be.
940 				 */
941 
942 #ifdef CY_DEBUG
943 				printf("%s: port %d ttyinput 0x%x\n",
944 				    sc->sc_dev.dv_xname, port, chr);
945 #endif
946 
947 				(*tp->t_linesw->l_rint) (chr, tp);
948 
949 				s = spltty();	/* really necessary? */
950 				if ((cy->cy_ibuf_rd_ptr += 2) ==
951 				    cy->cy_ibuf_end)
952 					cy->cy_ibuf_rd_ptr = cy->cy_ibuf;
953 				splx(s);
954 
955 #ifdef CY_DEBUG1
956 				did_something = 1;
957 #endif
958 			}
959 
960 			/*
961 			 * If we don't have any received data in ibuf and
962 			 * CRTSCTS is on and RTS is turned off, it is time to
963 			 * turn RTS back on
964 			 */
965 			if (ISSET(tp->t_cflag, CRTSCTS)) {
966 				/*
967 				 * we can't use cy_modem_control() here as it
968 				 * doesn't change RTS if RTSCTS is on
969 				 */
970 				cd_write_reg(sc, cy->cy_chip, CD1400_CAR,
971 				    port & CD1400_CAR_CHAN);
972 
973 				if (cy->cy_clock == CY_CLOCK_60) {
974 				  if ((cd_read_reg(sc, cy->cy_chip,
975 				    CD1400_MSVR2) & CD1400_MSVR2_DTR) == 0) {
976 					cd_write_reg(sc, cy->cy_chip,
977 					CD1400_MSVR2,CD1400_MSVR2_DTR);
978 #ifdef CY_DEBUG1
979 					did_something = 1;
980 #endif
981 				  }
982 				} else {
983 				  if ((cd_read_reg(sc, cy->cy_chip,
984 				    CD1400_MSVR1) & CD1400_MSVR1_RTS) == 0) {
985 					cd_write_reg(sc, cy->cy_chip,
986 					CD1400_MSVR1,CD1400_MSVR1_RTS);
987 #ifdef CY_DEBUG1
988 					did_something = 1;
989 #endif
990 				  }
991 				}
992 			}
993 
994 			/*
995 		         * handle carrier changes
996 		         */
997 			s = spltty();
998 			if (ISSET(cy->cy_flags, CY_F_CARRIER_CHANGED)) {
999 				int             carrier;
1000 
1001 				CLR(cy->cy_flags, CY_F_CARRIER_CHANGED);
1002 				splx(s);
1003 
1004 				carrier = ((cy->cy_carrier_stat &
1005 				    CD1400_MSVR2_CD) != 0);
1006 
1007 #ifdef CY_DEBUG
1008 				printf("cy_poll: carrier change "
1009 				    "(card %d, port %d, carrier %d)\n",
1010 				    card, port, carrier);
1011 #endif
1012 				if (CY_DIALOUT(tp->t_dev) == 0 &&
1013 				    !(*tp->t_linesw->l_modem)(tp, carrier))
1014 					cy_modem_control(sc, cy,
1015 					    TIOCM_DTR, DMBIC);
1016 
1017 #ifdef CY_DEBUG1
1018 				did_something = 1;
1019 #endif
1020 			} else
1021 				splx(s);
1022 
1023 			s = spltty();
1024 			if (ISSET(cy->cy_flags, CY_F_START)) {
1025 				CLR(cy->cy_flags, CY_F_START);
1026 				splx(s);
1027 
1028 				(*tp->t_linesw->l_start) (tp);
1029 
1030 #ifdef CY_DEBUG1
1031 				did_something = 1;
1032 #endif
1033 			} else
1034 				splx(s);
1035 
1036 			/* could move this to even upper level... */
1037 			if (cy->cy_fifo_overruns) {
1038 				cy->cy_fifo_overruns = 0;
1039 				/*
1040 				 * doesn't report overrun count, but
1041 				 * shouldn't really matter
1042 				 */
1043 				log(LOG_WARNING, "%s: port %d fifo overrun\n",
1044 				    sc->sc_dev.dv_xname, port);
1045 			}
1046 			if (cy->cy_ibuf_overruns) {
1047 				cy->cy_ibuf_overruns = 0;
1048 				log(LOG_WARNING, "%s: port %d ibuf overrun\n",
1049 				    sc->sc_dev.dv_xname, port);
1050 			}
1051 		}		/* for(port...) */
1052 #ifdef CY_DEBUG1
1053 		if (did_something && counter >= 200)
1054 			sc->sc_poll_count2++;
1055 #endif
1056 	} /* for(card...) */
1057 
1058 	counter = 0;
1059 
1060 out:
1061 	callout_reset(&cy_poll_callout, 1, cy_poll, NULL);
1062 }
1063 
1064 /*
1065  * hardware interrupt routine
1066  */
1067 int
1068 cy_intr(void *arg)
1069 {
1070 	struct cy_softc *sc = arg;
1071 	struct cy_port *cy;
1072 	int cy_chip, stat;
1073 	int int_serviced = 0;
1074 
1075 	/*
1076 	 * Check interrupt status of each CD1400 chip on this card
1077 	 * (multiple cards cannot share the same interrupt)
1078 	 */
1079 	for (cy_chip = 0; cy_chip < sc->sc_nchips; cy_chip++) {
1080 
1081 		stat = cd_read_reg(sc, cy_chip, CD1400_SVRR);
1082 		if (stat == 0)
1083 			continue;
1084 
1085 		if (ISSET(stat, CD1400_SVRR_RXRDY)) {
1086 			u_char save_car, save_rir, serv_type;
1087 			u_char line_stat, recv_data, n_chars;
1088 			u_char *buf_p;
1089 
1090 			save_rir = cd_read_reg(sc, cy_chip, CD1400_RIR);
1091 			save_car = cd_read_reg(sc, cy_chip, CD1400_CAR);
1092 			/* enter rx service */
1093 			cd_write_reg(sc, cy_chip, CD1400_CAR, save_rir);
1094 
1095 			serv_type = cd_read_reg(sc, cy_chip, CD1400_RIVR);
1096 			cy = &sc->sc_ports[serv_type >> 3];
1097 
1098 #ifdef CY_DEBUG1
1099 			cy->cy_rx_int_count++;
1100 #endif
1101 
1102 			buf_p = cy->cy_ibuf_wr_ptr;
1103 
1104 			if (ISSET(serv_type, CD1400_RIVR_EXCEPTION)) {
1105 				line_stat = cd_read_reg(sc, cy->cy_chip,
1106 				    CD1400_RDSR);
1107 				recv_data = cd_read_reg(sc, cy->cy_chip,
1108 				    CD1400_RDSR);
1109 
1110 				if (cy->cy_tty == NULL ||
1111 				    !ISSET(cy->cy_tty->t_state, TS_ISOPEN))
1112 					goto end_rx_serv;
1113 
1114 #ifdef CY_DEBUG
1115 				printf("%s port %d recv exception, line_stat 0x%x, char 0x%x\n",
1116 				sc->sc_dev.dv_xname, cy->cy_port_num, line_stat, recv_data);
1117 #endif
1118 				if (ISSET(line_stat, CD1400_RDSR_OE))
1119 					cy->cy_fifo_overruns++;
1120 
1121 				*buf_p++ = line_stat;
1122 				*buf_p++ = recv_data;
1123 				if (buf_p == cy->cy_ibuf_end)
1124 					buf_p = cy->cy_ibuf;
1125 
1126 				if (buf_p == cy->cy_ibuf_rd_ptr) {
1127 					if (buf_p == cy->cy_ibuf)
1128 						buf_p = cy->cy_ibuf_end;
1129 					buf_p -= 2;
1130 					cy->cy_ibuf_overruns++;
1131 				}
1132 				cy_events = 1;
1133 			} else {/* no exception, received data OK */
1134 				n_chars = cd_read_reg(sc, cy->cy_chip,
1135 				    CD1400_RDCR);
1136 
1137 				/* If no tty or not open, discard data */
1138 				if (cy->cy_tty == NULL ||
1139 				    !ISSET(cy->cy_tty->t_state, TS_ISOPEN)) {
1140 					while (n_chars--)
1141 						cd_read_reg(sc, cy->cy_chip,
1142 							    CD1400_RDSR);
1143 					goto end_rx_serv;
1144 				}
1145 
1146 #ifdef CY_DEBUG
1147 				printf("%s port %d receive ok %d chars\n",
1148 				    sc->sc_dev.dv_xname, cy->cy_port_num, n_chars);
1149 #endif
1150 				while (n_chars--) {
1151 					*buf_p++ = 0;	/* status: OK */
1152 					/* data byte */
1153 					*buf_p++ = cd_read_reg(sc,
1154 					    cy->cy_chip, CD1400_RDSR);
1155 					if (buf_p == cy->cy_ibuf_end)
1156 						buf_p = cy->cy_ibuf;
1157 					if (buf_p == cy->cy_ibuf_rd_ptr) {
1158 						if (buf_p == cy->cy_ibuf)
1159 							buf_p = cy->cy_ibuf_end;
1160 						buf_p -= 2;
1161 						cy->cy_ibuf_overruns++;
1162 						break;
1163 					}
1164 				}
1165 				cy_events = 1;
1166 			}
1167 
1168 			cy->cy_ibuf_wr_ptr = buf_p;
1169 
1170 			/* RTS handshaking for incoming data */
1171 			if (ISSET(cy->cy_tty->t_cflag, CRTSCTS)) {
1172 				int bf, msvr;
1173 
1174 				bf = buf_p - cy->cy_ibuf_rd_ptr;
1175 				if (bf < 0)
1176 					bf += CY_IBUF_SIZE;
1177 
1178 				if (bf > (CY_IBUF_SIZE / 2)) {
1179 					/* turn RTS off */
1180 					if (cy->cy_clock == CY_CLOCK_60)
1181 						msvr = CD1400_MSVR2;
1182 					else
1183 						msvr = CD1400_MSVR1;
1184 					cd_write_reg(sc, cy->cy_chip, msvr, 0);
1185 				}
1186 			}
1187 
1188 	end_rx_serv:
1189 			/* terminate service context */
1190 			cd_write_reg(sc, cy->cy_chip, CD1400_RIR,
1191 				     save_rir & 0x3f);
1192 			cd_write_reg(sc, cy->cy_chip, CD1400_CAR, save_car);
1193 			int_serviced = 1;
1194 		} /* if (rx_service...) */
1195 		if (ISSET(stat, CD1400_SVRR_MDMCH)) {
1196 			u_char save_car, save_mir, serv_type, modem_stat;
1197 
1198 			save_mir = cd_read_reg(sc, cy_chip, CD1400_MIR);
1199 			save_car = cd_read_reg(sc, cy_chip, CD1400_CAR);
1200 			/* enter modem service */
1201 			cd_write_reg(sc, cy_chip, CD1400_CAR, save_mir);
1202 
1203 			serv_type = cd_read_reg(sc, cy_chip, CD1400_MIVR);
1204 			cy = &sc->sc_ports[serv_type >> 3];
1205 
1206 #ifdef CY_DEBUG1
1207 			cy->cy_modem_int_count++;
1208 #endif
1209 
1210 			modem_stat = cd_read_reg(sc, cy->cy_chip, CD1400_MSVR2);
1211 
1212 #ifdef CY_DEBUG
1213 			printf("%s port %d modem line change, new stat 0x%x\n",
1214 			       sc->sc_dev.dv_xname, cy->cy_port_num, modem_stat);
1215 #endif
1216 			if (ISSET((cy->cy_carrier_stat ^ modem_stat), CD1400_MSVR2_CD)) {
1217 				SET(cy->cy_flags, CY_F_CARRIER_CHANGED);
1218 				cy_events = 1;
1219 			}
1220 			cy->cy_carrier_stat = modem_stat;
1221 
1222 			/* terminate service context */
1223 			cd_write_reg(sc, cy->cy_chip, CD1400_MIR, save_mir & 0x3f);
1224 			cd_write_reg(sc, cy->cy_chip, CD1400_CAR, save_car);
1225 			int_serviced = 1;
1226 		} /* if (modem_service...) */
1227 		if (ISSET(stat, CD1400_SVRR_TXRDY)) {
1228 			u_char          save_car, save_tir, serv_type,
1229 			                count, ch;
1230 			struct tty     *tp;
1231 
1232 			save_tir = cd_read_reg(sc, cy_chip, CD1400_TIR);
1233 			save_car = cd_read_reg(sc, cy_chip, CD1400_CAR);
1234 			/* enter tx service */
1235 			cd_write_reg(sc, cy_chip, CD1400_CAR, save_tir);
1236 
1237 			serv_type = cd_read_reg(sc, cy_chip, CD1400_TIVR);
1238 			cy = &sc->sc_ports[serv_type >> 3];
1239 
1240 #ifdef CY_DEBUG1
1241 			cy->cy_tx_int_count++;
1242 #endif
1243 #ifdef CY_DEBUG
1244 			printf("%s port %d tx service\n", sc->sc_dev.dv_xname,
1245 			    cy->cy_port_num);
1246 #endif
1247 
1248 			/* stop transmitting if no tty or CY_F_STOP set */
1249 			tp = cy->cy_tty;
1250 			if (tp == NULL || ISSET(cy->cy_flags, CY_F_STOP))
1251 				goto txdone;
1252 
1253 			count = 0;
1254 			if (ISSET(cy->cy_flags, CY_F_SEND_NUL)) {
1255 				cd_write_reg(sc, cy->cy_chip, CD1400_TDR, 0);
1256 				cd_write_reg(sc, cy->cy_chip, CD1400_TDR, 0);
1257 				count += 2;
1258 				CLR(cy->cy_flags, CY_F_SEND_NUL);
1259 			}
1260 			if (tp->t_outq.c_cc > 0) {
1261 				SET(tp->t_state, TS_BUSY);
1262 				while (tp->t_outq.c_cc > 0 &&
1263 				    count < CD1400_TX_FIFO_SIZE) {
1264 					ch = getc(&tp->t_outq);
1265 					/*
1266 					 * remember to double NUL characters
1267 					 * because embedded transmit commands
1268 					 * are enabled
1269 					 */
1270 					if (ch == 0) {
1271 						if (count >= CD1400_TX_FIFO_SIZE - 2) {
1272 							SET(cy->cy_flags, CY_F_SEND_NUL);
1273 							break;
1274 						}
1275 						cd_write_reg(sc, cy->cy_chip,
1276 						    CD1400_TDR, ch);
1277 						count++;
1278 					}
1279 					cd_write_reg(sc, cy->cy_chip,
1280 					    CD1400_TDR, ch);
1281 					count++;
1282 				}
1283 			} else {
1284 				/*
1285 				 * no data to send -- check if we should
1286 				 * start/stop a break
1287 				 */
1288 				/*
1289 				 * XXX does this cause too much delay before
1290 				 * breaks?
1291 				 */
1292 				if (ISSET(cy->cy_flags, CY_F_START_BREAK)) {
1293 					cd_write_reg(sc, cy->cy_chip,
1294 					    CD1400_TDR, 0);
1295 					cd_write_reg(sc, cy->cy_chip,
1296 					    CD1400_TDR, 0x81);
1297 					CLR(cy->cy_flags, CY_F_START_BREAK);
1298 				}
1299 				if (ISSET(cy->cy_flags, CY_F_END_BREAK)) {
1300 					cd_write_reg(sc, cy->cy_chip,
1301 					    CD1400_TDR, 0);
1302 					cd_write_reg(sc, cy->cy_chip,
1303 					    CD1400_TDR, 0x83);
1304 					CLR(cy->cy_flags, CY_F_END_BREAK);
1305 				}
1306 			}
1307 
1308 			if (tp->t_outq.c_cc == 0) {
1309 		txdone:
1310 				/*
1311 				 * No data to send or requested to stop.
1312 				 * Disable transmit interrupt
1313 				 */
1314 				cd_write_reg(sc, cy->cy_chip, CD1400_SRER,
1315 				     cd_read_reg(sc, cy->cy_chip, CD1400_SRER)
1316 				     & ~CD1400_SRER_TXRDY);
1317 				CLR(cy->cy_flags, CY_F_STOP);
1318 				CLR(tp->t_state, TS_BUSY);
1319 			}
1320 			if (tp->t_outq.c_cc <= tp->t_lowat) {
1321 				SET(cy->cy_flags, CY_F_START);
1322 				cy_events = 1;
1323 			}
1324 			/* terminate service context */
1325 			cd_write_reg(sc, cy->cy_chip, CD1400_TIR, save_tir & 0x3f);
1326 			cd_write_reg(sc, cy->cy_chip, CD1400_CAR, save_car);
1327 			int_serviced = 1;
1328 		}		/* if (tx_service...) */
1329 	}			/* for(...all CD1400s on a card) */
1330 
1331 	/* ensure an edge for next interrupt */
1332 	bus_space_write_1(sc->sc_memt, sc->sc_bsh,
1333 			CY_CLEAR_INTR << sc->sc_bustype, 0);
1334 	return int_serviced;
1335 }
1336 
1337 /*
1338  * subroutine to enable CD1400 transmitter
1339  */
1340 void
1341 cy_enable_transmitter(struct cy_softc *sc, struct cy_port *cy)
1342 {
1343 	int s = spltty();
1344 	cd_write_reg(sc, cy->cy_chip, CD1400_CAR,
1345 	    cy->cy_port_num & CD1400_CAR_CHAN);
1346 	cd_write_reg(sc, cy->cy_chip, CD1400_SRER,
1347 	    cd_read_reg(sc, cy->cy_chip, CD1400_SRER) | CD1400_SRER_TXRDY);
1348 	splx(s);
1349 }
1350 
1351 /*
1352  * Execute a CD1400 channel command
1353  */
1354 void
1355 cd1400_channel_cmd(struct cy_softc *sc, struct cy_port *cy, int cmd)
1356 {
1357 	u_int waitcnt = 5 * 8 * 1024;	/* approx 5 ms */
1358 
1359 #ifdef CY_DEBUG
1360 	printf("c1400_channel_cmd cy %p command 0x%x\n", cy, cmd);
1361 #endif
1362 
1363 	/* wait until cd1400 is ready to process a new command */
1364 	while (cd_read_reg(sc, cy->cy_chip, CD1400_CCR) != 0 && waitcnt-- > 0);
1365 
1366 	if (waitcnt == 0)
1367 		log(LOG_ERR, "%s: channel command timeout\n",
1368 		    sc->sc_dev.dv_xname);
1369 
1370 	cd_write_reg(sc, cy->cy_chip, CD1400_CCR, cmd);
1371 }
1372 
1373 /*
1374  * Compute clock option register and baud rate register values
1375  * for a given speed. Return 0 on success, -1 on failure.
1376  *
1377  * The error between requested and actual speed seems
1378  * to be well within allowed limits (less than 3%)
1379  * with every speed value between 50 and 150000 bps.
1380  */
1381 int
1382 cy_speed(speed_t speed, int *cor, int *bpr, int cy_clock)
1383 {
1384 	int c, co, br;
1385 
1386 	if (speed < 50 || speed > 150000)
1387 		return -1;
1388 
1389 	for (c = 0, co = 8; co <= 2048; co <<= 2, c++) {
1390 		br = (cy_clock + (co * speed) / 2) / (co * speed);
1391 		if (br < 0x100) {
1392 			*bpr = br;
1393 			*cor = c;
1394 			return 0;
1395 		}
1396 	}
1397 
1398 	return -1;
1399 }
1400