xref: /netbsd-src/sys/dev/ic/cy.c (revision c0179c282a5968435315a82f4128c61372c68fc3)
1 /*	$NetBSD: cy.c,v 1.48 2006/11/16 01:32:51 christos 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 1.48 2006/11/16 01:32:51 christos 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 #include <sys/kauth.h>
36 
37 #include <machine/bus.h>
38 
39 #include <dev/ic/cd1400reg.h>
40 #include <dev/ic/cyreg.h>
41 #include <dev/ic/cyvar.h>
42 
43 int	cyparam(struct tty *, struct termios *);
44 void	cystart(struct tty *);
45 void	cy_poll(void *);
46 int	cy_modem_control(struct cy_softc *, struct cy_port *, int, int);
47 void	cy_enable_transmitter(struct cy_softc *, struct cy_port *);
48 void	cd1400_channel_cmd(struct cy_softc *, struct cy_port *, int);
49 int	cy_speed(speed_t, int *, int *, int);
50 
51 extern struct cfdriver cy_cd;
52 
53 dev_type_open(cyopen);
54 dev_type_close(cyclose);
55 dev_type_read(cyread);
56 dev_type_write(cywrite);
57 dev_type_ioctl(cyioctl);
58 dev_type_stop(cystop);
59 dev_type_tty(cytty);
60 dev_type_poll(cypoll);
61 
62 const struct cdevsw cy_cdevsw = {
63 	cyopen, cyclose, cyread, cywrite, cyioctl,
64 	cystop, cytty, cypoll, nommap, ttykqfilter, D_TTY
65 };
66 
67 static int      cy_open = 0;
68 static int      cy_events = 0;
69 
70 int	cy_attached_ttys;
71 
72 struct callout cy_poll_callout = CALLOUT_INITIALIZER;
73 
74 /*
75  * Common probe routine
76  */
77 int
78 cy_find(struct cy_softc *sc)
79 {
80 	int cy_chip, chip;
81 	u_char firmware_ver;
82 	bus_space_tag_t tag = sc->sc_memt;
83 	bus_space_handle_t bsh = sc->sc_bsh;
84 	int bustype = sc->sc_bustype;
85 
86 	/* Cyclom card hardware reset */
87 	bus_space_write_1(tag, bsh, CY16_RESET << bustype, 0);
88 	DELAY(500);		/* wait for reset to complete */
89 	bus_space_write_1(tag, bsh, CY_CLEAR_INTR << bustype, 0);
90 
91 #ifdef CY_DEBUG
92 	printf("cy: card reset done\n");
93 #endif
94 	sc->sc_nchips = 0;
95 
96 	for (cy_chip = 0, chip = 0; cy_chip < CY_MAX_CD1400s;
97 	    cy_chip++, chip += (CY_CD1400_MEMSPACING << bustype)) {
98 		int i;
99 
100 		/*
101 		 * the last 4 nchips are 'interleaved' with the first 4 on
102 		 * 32-port boards
103 		 */
104 		if (cy_chip == 4)
105 			chip -= (CY32_ADDR_FIX << bustype);
106 
107 #ifdef CY_DEBUG
108 		printf("%s probe chip %d offset 0x%x ... ",
109 		    sc->sc_dev.dv_xname, cy_chip, chip);
110 #endif
111 
112 		/* wait until the chip is ready for command */
113 		DELAY(1000);
114 		if (bus_space_read_1(tag, bsh, chip +
115 		    ((CD1400_CCR << 1) << bustype)) != 0) {
116 #ifdef CY_DEBUG
117 			printf("not ready for command\n");
118 #endif
119 			break;
120 		}
121 		/* clear the firmware version reg. */
122 		bus_space_write_1(tag, bsh, chip +
123 		    ((CD1400_GFRCR << 1) << bustype), 0);
124 
125 		/*
126 	         * On Cyclom-16 references to non-existent chip 4
127 	         * actually access chip 0 (address line 9 not decoded).
128 	         * Here we check if the clearing of chip 4 GFRCR actually
129 	         * cleared chip 0 GFRCR. In that case we have a 16 port card.
130 	         */
131 		if (cy_chip == 4 &&
132 		    bus_space_read_1(tag, bsh, /* off for chip 0 (0) + */
133 		       ((CD1400_GFRCR << 1) << bustype)) == 0)
134 			break;
135 
136 		/* reset the chip */
137 		bus_space_write_1(tag, bsh, chip +
138 		    ((CD1400_CCR << 1) << bustype),
139 		    CD1400_CCR_CMDRESET | CD1400_CCR_FULLRESET);
140 
141 		/* wait for the chip to initialize itself */
142 		for (i = 0; i < 200; i++) {
143 			DELAY(50);
144 			firmware_ver = bus_space_read_1(tag, bsh, chip +
145 			    ((CD1400_GFRCR << 1) << bustype));
146 			if ((firmware_ver & 0xf0) == 0x40) /* found a CD1400 */
147 				break;
148 		}
149 #ifdef CY_DEBUG
150 		printf("firmware version 0x%x\n", firmware_ver);
151 #endif
152 
153 		if ((firmware_ver & 0xf0) != 0x40)
154 			break;
155 
156 		/* firmware version OK, CD1400 found */
157 		sc->sc_nchips++;
158 	}
159 
160 	if (sc->sc_nchips == 0) {
161 #ifdef CY_DEBUG
162 		printf("no CD1400s found\n");
163 #endif
164 		return 0;
165 	}
166 #ifdef CY_DEBUG
167 	printf("found %d CD1400s\n", sc->sc_nchips);
168 #endif
169 
170 	return 1;
171 }
172 
173 void
174 cy_attach(struct cy_softc *sc)
175 {
176 	int port, cy_chip, num_chips, cdu, chip;
177 	int cy_clock;
178 
179 	num_chips = sc->sc_nchips;
180 	if (num_chips == 0)
181 		return;
182 
183 	memset(sc->sc_ports, 0, sizeof(sc->sc_ports));
184 
185 	port = 0;
186 	for (cy_chip = 0, chip = 0; cy_chip < num_chips; cy_chip++,
187 	    chip += (CY_CD1400_MEMSPACING << sc->sc_bustype)) {
188 
189 		if (cy_chip == 4)
190 			chip -= (CY32_ADDR_FIX << sc->sc_bustype);
191 
192 #ifdef CY_DEBUG
193 		aprint_debug("attach CD1400 #%d offset 0x%x\n", cy_chip, chip);
194 #endif
195 		sc->sc_cd1400_offs[cy_chip] = chip;
196 
197 		/*
198 		 * configure port 0 as serial port (should already be after
199 		 * reset)
200 		 */
201 		cd_write_reg(sc, cy_chip, CD1400_GCR, 0);
202 
203 		if (cd_read_reg(sc, cy_chip, CD1400_GFRCR) <= 0x46)
204 			cy_clock = CY_CLOCK;
205 		else
206 			cy_clock = CY_CLOCK_60;
207 
208 		/* set up a receive timeout period (1ms) */
209 		cd_write_reg(sc, cy_chip, CD1400_PPR,
210 		    (cy_clock / CD1400_PPR_PRESCALER / 1000) + 1);
211 
212 		for (cdu = 0; cdu < CD1400_NO_OF_CHANNELS; cdu++) {
213 			sc->sc_ports[port].cy_softc = sc;
214 			sc->sc_ports[port].cy_port_num = port;
215 			sc->sc_ports[port].cy_chip = cy_chip;
216 			sc->sc_ports[port].cy_clock = cy_clock;
217 
218 			/* should we initialize anything else here? */
219 			port++;
220 		} /* for(each port on one CD1400...) */
221 
222 	} /* for(each CD1400 on a card... ) */
223 
224 	sc->sc_nchannels = port;
225 
226 	aprint_normal("%s: %d channels (ttyCY%03d..ttyCY%03d)\n",
227 	    sc->sc_dev.dv_xname, sc->sc_nchannels, cy_attached_ttys,
228 	    cy_attached_ttys + (sc->sc_nchannels - 1));
229 
230 	cy_attached_ttys += sc->sc_nchannels;
231 
232 	/* ensure an edge for the next interrupt */
233 	bus_space_write_1(sc->sc_memt, sc->sc_bsh,
234 	    CY_CLEAR_INTR << sc->sc_bustype, 0);
235 }
236 
237 #define	CYDIALOUT_MASK		0x80000
238 #define	CY_DIALOUT(dev)		(minor(dev) & CYDIALOUT_MASK)
239 
240 #define	CY_PORT(dev)		cy_getport((dev))
241 #define	CY_BOARD(cy)		((cy)->cy_softc)
242 
243 static struct cy_port *
244 cy_getport(dev_t dev)
245 {
246 	int i, j, k, u = minor(dev) & ~CYDIALOUT_MASK;
247 	struct cy_softc *sc;
248 
249 	for (i = 0, j = 0; i < cy_cd.cd_ndevs; i++) {
250 		k = j;
251 		sc = device_lookup(&cy_cd, i);
252 		if (sc == NULL)
253 			continue;
254 		if (sc->sc_nchannels == 0)
255 			continue;
256 		j += sc->sc_nchannels;
257 		if (j > u)
258 			return (&sc->sc_ports[u - k]);
259 	}
260 
261 	return (NULL);
262 }
263 
264 /*
265  * open routine. returns zero if successful, else error code
266  */
267 int
268 cyopen(dev_t dev, int flag, int mode, struct lwp *l)
269 {
270 	struct cy_softc *sc;
271 	struct cy_port *cy;
272 	struct tty *tp;
273 	int s, error;
274 
275 	cy = CY_PORT(dev);
276 	if (cy == NULL)
277 		return (ENXIO);
278 	sc = CY_BOARD(cy);
279 
280 	s = spltty();
281 	if (cy->cy_tty == NULL) {
282 		if ((cy->cy_tty = ttymalloc()) == NULL) {
283 			splx(s);
284 			printf("%s: port %d: can't allocate tty\n",
285 			    sc->sc_dev.dv_xname, cy->cy_port_num);
286 			return (ENOMEM);
287 		}
288 		tty_attach(cy->cy_tty);
289 	}
290 	splx(s);
291 
292 	tp = cy->cy_tty;
293 	tp->t_oproc = cystart;
294 	tp->t_param = cyparam;
295 	tp->t_dev = dev;
296 
297 	if (kauth_authorize_device_tty(l->l_cred, KAUTH_DEVICE_TTY_OPEN, tp))
298 		return (EBUSY);
299 
300 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
301 		ttychars(tp);
302 		tp->t_iflag = TTYDEF_IFLAG;
303 		tp->t_oflag = TTYDEF_OFLAG;
304 		tp->t_cflag = TTYDEF_CFLAG;
305 		if (ISSET(cy->cy_openflags, TIOCFLAG_CLOCAL))
306 			SET(tp->t_cflag, CLOCAL);
307 		if (ISSET(cy->cy_openflags, TIOCFLAG_CRTSCTS))
308 			SET(tp->t_cflag, CRTSCTS);
309 		if (ISSET(cy->cy_openflags, TIOCFLAG_MDMBUF))
310 			SET(tp->t_cflag, MDMBUF);
311 		tp->t_lflag = TTYDEF_LFLAG;
312 		tp->t_ispeed = tp->t_ospeed = TTYDEF_SPEED;
313 
314 		s = spltty();
315 
316 		/*
317 		 * Allocate input ring buffer if we don't already have one
318 		 */
319 		if (cy->cy_ibuf == NULL) {
320 			cy->cy_ibuf = malloc(CY_IBUF_SIZE, M_DEVBUF, M_NOWAIT);
321 			if (cy->cy_ibuf == NULL) {
322 				printf("%s: port %d: can't allocate input buffer\n",
323 				       sc->sc_dev.dv_xname, cy->cy_port_num);
324 				splx(s);
325 				return ENOMEM;
326 			}
327 			cy->cy_ibuf_end = cy->cy_ibuf + CY_IBUF_SIZE;
328 		}
329 		/* mark the ring buffer as empty */
330 		cy->cy_ibuf_rd_ptr = cy->cy_ibuf_wr_ptr = cy->cy_ibuf;
331 
332 		/* select CD1400 channel */
333 		cd_write_reg(sc, cy->cy_chip, CD1400_CAR,
334 		    cy->cy_port_num & CD1400_CAR_CHAN);
335 		/* reset the channel */
336 		cd1400_channel_cmd(sc, cy, CD1400_CCR_CMDRESET);
337 		/* encode unit (port) number in LIVR */
338 		/* there is just enough space for 5 bits (32 ports) */
339 		cd_write_reg(sc, cy->cy_chip, CD1400_LIVR,
340 		    cy->cy_port_num << 3);
341 
342 		cy->cy_channel_control = 0;
343 
344 		/* hmm... need spltty() here? */
345 		if (cy_open == 0) {
346 			cy_open = 1;
347 			callout_reset(&cy_poll_callout, 1, cy_poll, NULL);
348 		}
349 		/* this sets parameters and raises DTR */
350 		cyparam(tp, &tp->t_termios);
351 
352 		ttsetwater(tp);
353 
354 		/* raise RTS too */
355 		cy_modem_control(sc, cy, TIOCM_RTS, DMBIS);
356 
357 		cy->cy_carrier_stat =
358 			cd_read_reg(sc, cy->cy_chip, CD1400_MSVR2);
359 
360 		/* enable receiver and modem change interrupts */
361 		cd_write_reg(sc, cy->cy_chip, CD1400_SRER,
362 		    CD1400_SRER_MDMCH | CD1400_SRER_RXDATA);
363 
364 		if (CY_DIALOUT(dev) ||
365 		    ISSET(cy->cy_openflags, TIOCFLAG_SOFTCAR) ||
366 		    ISSET(tp->t_cflag, MDMBUF) ||
367 		    ISSET(cy->cy_carrier_stat, CD1400_MSVR2_CD))
368 			SET(tp->t_state, TS_CARR_ON);
369 		else
370 			CLR(tp->t_state, TS_CARR_ON);
371 	} else {
372 		s = spltty();
373 	}
374 
375 	/* wait for carrier if necessary */
376 	if (!ISSET(flag, O_NONBLOCK)) {
377 		while (!ISSET(tp->t_cflag, CLOCAL) &&
378 		    !ISSET(tp->t_state, TS_CARR_ON)) {
379 			tp->t_wopen++;
380 			error = ttysleep(tp, &tp->t_rawq, TTIPRI | PCATCH,
381 			    "cydcd", 0);
382 			tp->t_wopen--;
383 			if (error != 0) {
384 				splx(s);
385 				return error;
386 			}
387 		}
388 	}
389 	splx(s);
390 
391 	return (*tp->t_linesw->l_open) (dev, tp);
392 }
393 
394 /*
395  * close routine. returns zero if successful, else error code
396  */
397 int
398 cyclose(dev_t dev, int flag, int mode, struct lwp *l)
399 {
400 	struct cy_softc *sc;
401 	struct cy_port *cy;
402 	struct tty *tp;
403 	int s;
404 
405 	cy = CY_PORT(dev);
406 	sc = CY_BOARD(cy);
407 	tp = cy->cy_tty;
408 
409 	(*tp->t_linesw->l_close) (tp, flag);
410 	s = spltty();
411 
412 	if (ISSET(tp->t_cflag, HUPCL) &&
413 	    !ISSET(cy->cy_openflags, TIOCFLAG_SOFTCAR)) {
414 		/*
415 		 * drop DTR and RTS (should we wait for output buffer to
416 		 * become empty first?)
417 		 */
418 		cy_modem_control(sc, cy, 0, DMSET);
419 	}
420 	/*
421 	 * XXX should we disable modem change and
422 	 * receive interrupts here or somewhere ?
423 	 */
424 	CLR(tp->t_state, TS_BUSY | TS_FLUSH);
425 
426 	splx(s);
427 	ttyclose(tp);
428 
429 	return 0;
430 }
431 
432 /*
433  * Read routine
434  */
435 int
436 cyread(dev_t dev, struct uio *uio, int flag)
437 {
438 	struct cy_port *cy;
439 	struct tty *tp;
440 
441 	cy = CY_PORT(dev);
442 	tp = cy->cy_tty;
443 
444 	return ((*tp->t_linesw->l_read)(tp, uio, flag));
445 }
446 
447 /*
448  * Write routine
449  */
450 int
451 cywrite(dev_t dev, struct uio *uio, int flag)
452 {
453 	struct cy_port *cy;
454 	struct tty *tp;
455 
456 	cy = CY_PORT(dev);
457 	tp = cy->cy_tty;
458 
459 	return ((*tp->t_linesw->l_write)(tp, uio, flag));
460 }
461 
462 /*
463  * Poll routine
464  */
465 int
466 cypoll(dev_t dev, int events, struct lwp *l)
467 {
468 	struct cy_port *cy;
469 	struct tty *tp;
470 
471 	cy = CY_PORT(dev);
472 	tp = cy->cy_tty;
473 
474 	return ((*tp->t_linesw->l_poll)(tp, events, l));
475 }
476 
477 /*
478  * return tty pointer
479  */
480 struct tty *
481 cytty(dev_t dev)
482 {
483 	struct cy_port *cy;
484 
485 	cy = CY_PORT(dev);
486 
487 	return (cy->cy_tty);
488 }
489 
490 /*
491  * ioctl routine
492  */
493 int
494 cyioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct lwp *l)
495 {
496 	struct cy_softc *sc;
497 	struct cy_port *cy;
498 	struct tty *tp;
499 	int error;
500 
501 	cy = CY_PORT(dev);
502 	sc = CY_BOARD(cy);
503 	tp = cy->cy_tty;
504 
505 	error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, l);
506 	if (error != EPASSTHROUGH)
507 		return error;
508 
509 	error = ttioctl(tp, cmd, data, flag, l);
510 	if (error != EPASSTHROUGH)
511 		return error;
512 
513 	/* XXX should not allow dropping DTR when dialin? */
514 
515 	switch (cmd) {
516 	case TIOCSBRK:		/* start break */
517 		SET(cy->cy_flags, CY_F_START_BREAK);
518 		cy_enable_transmitter(sc, cy);
519 		break;
520 
521 	case TIOCCBRK:		/* stop break */
522 		SET(cy->cy_flags, CY_F_END_BREAK);
523 		cy_enable_transmitter(sc, cy);
524 		break;
525 
526 	case TIOCSDTR:		/* DTR on */
527 		cy_modem_control(sc, cy, TIOCM_DTR, DMBIS);
528 		break;
529 
530 	case TIOCCDTR:		/* DTR off */
531 		cy_modem_control(sc, cy, TIOCM_DTR, DMBIC);
532 		break;
533 
534 	case TIOCMSET:		/* set new modem control line values */
535 		cy_modem_control(sc, cy, *((int *) data), DMSET);
536 		break;
537 
538 	case TIOCMBIS:		/* turn modem control bits on */
539 		cy_modem_control(sc, cy, *((int *) data), DMBIS);
540 		break;
541 
542 	case TIOCMBIC:		/* turn modem control bits off */
543 		cy_modem_control(sc, cy, *((int *) data), DMBIC);
544 		break;
545 
546 	case TIOCMGET:		/* get modem control/status line state */
547 		*((int *) data) = cy_modem_control(sc, cy, 0, DMGET);
548 		break;
549 
550 	case TIOCGFLAGS:
551 		*((int *) data) = cy->cy_openflags |
552 			(CY_DIALOUT(dev) ? TIOCFLAG_SOFTCAR : 0);
553 		break;
554 
555 	case TIOCSFLAGS:
556 		error = kauth_authorize_device_tty(l->l_cred,
557 		    KAUTH_DEVICE_TTY_PRIVSET, tp);
558 		if (error != 0)
559 			return EPERM;
560 
561 		cy->cy_openflags = *((int *) data) &
562 		    (TIOCFLAG_SOFTCAR | TIOCFLAG_CLOCAL |
563 		     TIOCFLAG_CRTSCTS | TIOCFLAG_MDMBUF);
564 		break;
565 
566 	default:
567 		return EPASSTHROUGH;
568 	}
569 
570 	return 0;
571 }
572 
573 /*
574  * start output
575  */
576 void
577 cystart(struct tty *tp)
578 {
579 	struct cy_softc *sc;
580 	struct cy_port *cy;
581 	int s;
582 
583 	cy = CY_PORT(tp->t_dev);
584 	sc = cy->cy_softc;
585 
586 	s = spltty();
587 
588 #ifdef CY_DEBUG1
589 	cy->cy_start_count++;
590 #endif
591 
592 	if (!ISSET(tp->t_state, TS_TTSTOP | TS_TIMEOUT | TS_BUSY)) {
593 		if (tp->t_outq.c_cc <= tp->t_lowat) {
594 			if (ISSET(tp->t_state, TS_ASLEEP)) {
595 				CLR(tp->t_state, TS_ASLEEP);
596 				wakeup(&tp->t_outq);
597 			}
598 			selwakeup(&tp->t_wsel);
599 
600 			if (tp->t_outq.c_cc == 0)
601 				goto out;
602 		}
603 		SET(tp->t_state, TS_BUSY);
604 		cy_enable_transmitter(sc, cy);
605 	}
606 out:
607 
608 	splx(s);
609 }
610 
611 /*
612  * stop output
613  */
614 void
615 cystop(struct tty *tp, int flag)
616 {
617 	struct cy_port *cy;
618 	int s;
619 
620 	cy = CY_PORT(tp->t_dev);
621 
622 	s = spltty();
623 	if (ISSET(tp->t_state, TS_BUSY)) {
624 		if (!ISSET(tp->t_state, TS_TTSTOP))
625 			SET(tp->t_state, TS_FLUSH);
626 
627 		/*
628 		 * the transmit interrupt routine will disable transmit when it
629 		 * notices that CY_F_STOP has been set.
630 		 */
631 		SET(cy->cy_flags, CY_F_STOP);
632 	}
633 	splx(s);
634 }
635 
636 /*
637  * parameter setting routine.
638  * returns 0 if successful, else returns error code
639  */
640 int
641 cyparam(struct tty *tp, struct termios *t)
642 {
643 	struct cy_softc *sc;
644 	struct cy_port *cy;
645 	int ibpr = 0, obpr = 0, i_clk_opt = 0, o_clk_opt = 0;	/* XXX: GCC */
646 	int s, opt;
647 
648 	cy = CY_PORT(tp->t_dev);
649 	sc = CY_BOARD(cy);
650 
651 	if (t->c_ospeed != 0 && cy_speed(t->c_ospeed, &o_clk_opt, &obpr, cy->cy_clock) < 0)
652 		return EINVAL;
653 
654 	if (t->c_ispeed != 0 && cy_speed(t->c_ispeed, &i_clk_opt, &ibpr, cy->cy_clock) < 0)
655 		return EINVAL;
656 
657 	s = spltty();
658 
659 	/* hang up the line is ospeed is zero, else turn DTR on */
660 	cy_modem_control(sc, cy, TIOCM_DTR, (t->c_ospeed == 0 ? DMBIC : DMBIS));
661 
662 	/* channel was selected by the above call to cy_modem_control() */
663 #if 0
664 	cd_write_reg(sc, cy->cy_chip, CD1400_CAR, port & CD1400_CAR_CHAN);
665 #endif
666 
667 	/* set transmit speed */
668 	if (t->c_ospeed != 0) {
669 		cd_write_reg(sc, cy->cy_chip, CD1400_TCOR, o_clk_opt);
670 		cd_write_reg(sc, cy->cy_chip, CD1400_TBPR, obpr);
671 	}
672 	/* set receive speed */
673 	if (t->c_ispeed != 0) {
674 		cd_write_reg(sc, cy->cy_chip, CD1400_RCOR, i_clk_opt);
675 		cd_write_reg(sc, cy->cy_chip, CD1400_RBPR, ibpr);
676 	}
677 	opt = CD1400_CCR_CMDCHANCTL | CD1400_CCR_XMTEN
678 		| (ISSET(t->c_cflag, CREAD) ? CD1400_CCR_RCVEN : CD1400_CCR_RCVDIS);
679 
680 	if (opt != cy->cy_channel_control) {
681 		cy->cy_channel_control = opt;
682 		cd1400_channel_cmd(sc, cy, opt);
683 	}
684 	/* compute COR1 contents */
685 	opt = 0;
686 	if (ISSET(t->c_cflag, PARENB)) {
687 		if (ISSET(t->c_cflag, PARODD))
688 			opt |= CD1400_COR1_PARODD;
689 		opt |= CD1400_COR1_PARNORMAL;
690 	}
691 	if (!ISSET(t->c_iflag, INPCK))
692 		opt |= CD1400_COR1_NOINPCK;	/* no parity checking */
693 
694 	if (ISSET(t->c_cflag, CSTOPB))
695 		opt |= CD1400_COR1_STOP2;
696 
697 	switch (t->c_cflag & CSIZE) {
698 	case CS5:
699 		opt |= CD1400_COR1_CS5;
700 		break;
701 
702 	case CS6:
703 		opt |= CD1400_COR1_CS6;
704 		break;
705 
706 	case CS7:
707 		opt |= CD1400_COR1_CS7;
708 		break;
709 
710 	default:
711 		opt |= CD1400_COR1_CS8;
712 		break;
713 	}
714 
715 	cd_write_reg(sc, cy->cy_chip, CD1400_COR1, opt);
716 
717 #ifdef CY_DEBUG
718 	printf("cor1 = 0x%x...", opt);
719 #endif
720 
721 	/*
722 	 * use the CD1400 automatic CTS flow control if CRTSCTS is set
723 	 *
724 	 * CD1400_COR2_ETC is used because breaks are generated with
725 	 * embedded transmit commands
726 	 */
727 	cd_write_reg(sc, cy->cy_chip, CD1400_COR2,
728 		     CD1400_COR2_ETC |
729 		 (ISSET(t->c_cflag, CRTSCTS) ? CD1400_COR2_CCTS_OFLOW : 0));
730 
731 	cd_write_reg(sc, cy->cy_chip, CD1400_COR3, CY_RX_FIFO_THRESHOLD);
732 
733 	cd1400_channel_cmd(sc, cy, CD1400_CCR_CMDCORCHG |
734 	    CD1400_CCR_COR1 | CD1400_CCR_COR2 | CD1400_CCR_COR3);
735 
736 	cd_write_reg(sc, cy->cy_chip, CD1400_COR4, CD1400_COR4_PFO_EXCEPTION);
737 	cd_write_reg(sc, cy->cy_chip, CD1400_COR5, 0);
738 
739 	/*
740          * set modem change option registers to generate interrupts
741          * on carrier detect changes.
742          *
743          * if hardware RTS handshaking is used
744          * also set the handshaking threshold.
745          */
746 	if (cy->cy_clock == CY_CLOCK_60) {
747 	   cd_write_reg(sc, cy->cy_chip, CD1400_MCOR1, CD1400_MCOR1_CDzd |
748     	      (ISSET(t->c_cflag, CRTSCTS) ? CY_RX_DTR_THRESHOLD : 0));
749 	} else {
750 	   cd_write_reg(sc, cy->cy_chip, CD1400_MCOR1, CD1400_MCOR1_CDzd);
751 	}
752 
753 	cd_write_reg(sc, cy->cy_chip, CD1400_MCOR2, CD1400_MCOR2_CDod);
754 
755 	/*
756          * set receive timeout to approx. 2ms
757          * could use more complex logic here...
758          * (but is it actually needed or even useful?)
759          */
760 	cd_write_reg(sc, cy->cy_chip, CD1400_RTPR, 2);
761 
762 	/*
763          * should do anything else here?
764          * XXX check MDMBUF handshaking like in com.c?
765          */
766 
767 	splx(s);
768 	return 0;
769 }
770 
771 /*
772  * set/get modem line status
773  *
774  * bits can be: TIOCM_DTR, TIOCM_RTS, TIOCM_CTS, TIOCM_CD, TIOCM_RI, TIOCM_DSR
775  */
776 int
777 cy_modem_control(struct cy_softc *sc, struct cy_port *cy, int bits, int howto)
778 {
779 	struct tty *tp = cy->cy_tty;
780 	int s, msvr;
781 
782 	s = spltty();
783 
784 	/* select channel */
785 	cd_write_reg(sc, cy->cy_chip, CD1400_CAR,
786 	    cy->cy_port_num & CD1400_CAR_CHAN);
787 
788 	/* Does not manipulate RTS if it is used for flow control. */
789 	switch (howto) {
790 	case DMGET:
791 		bits = 0;
792 		if (cy->cy_channel_control & CD1400_CCR_RCVEN)
793 			bits |= TIOCM_LE;
794 		msvr = cd_read_reg(sc, cy->cy_chip, CD1400_MSVR2);
795 		if (cy->cy_clock == CY_CLOCK_60) {
796 			if (cd_read_reg(sc, cy->cy_chip, CD1400_MSVR1) &
797 		    		CD1400_MSVR1_RTS)
798 				bits |= TIOCM_DTR;
799 			if (msvr & CD1400_MSVR2_DTR)
800 				bits |= TIOCM_RTS;
801 		} else {
802 			if (cd_read_reg(sc, cy->cy_chip, CD1400_MSVR1) &
803 			    CD1400_MSVR1_RTS)
804 				bits |= TIOCM_RTS;
805 			if (msvr & CD1400_MSVR2_DTR)
806 				bits |= TIOCM_DTR;
807 		}
808 		if (msvr & CD1400_MSVR2_CTS)
809 			bits |= TIOCM_CTS;
810 		if (msvr & CD1400_MSVR2_CD)
811 			bits |= TIOCM_CD;
812 		/* Not connected on some Cyclom-Y boards? */
813 		if (msvr & CD1400_MSVR2_DSR)
814 			bits |= TIOCM_DSR;
815 		/* Not connected on some Cyclom-8Y boards? */
816 		if (msvr & CD1400_MSVR2_RI)
817 			bits |= TIOCM_RI;
818 		break;
819 
820 	case DMSET:		/* replace old values with new ones */
821 		if (cy->cy_clock == CY_CLOCK_60) {
822 			if (!ISSET(tp->t_cflag, CRTSCTS))
823 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR2,
824 				   ((bits & TIOCM_RTS) ? CD1400_MSVR2_DTR : 0));
825 			cd_write_reg(sc, cy->cy_chip, CD1400_MSVR1,
826 			    ((bits & TIOCM_DTR) ? CD1400_MSVR1_RTS : 0));
827 		} else {
828 			if (!ISSET(tp->t_cflag, CRTSCTS))
829 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR1,
830 				   ((bits & TIOCM_RTS) ? CD1400_MSVR1_RTS : 0));
831 			cd_write_reg(sc, cy->cy_chip, CD1400_MSVR2,
832 			    ((bits & TIOCM_DTR) ? CD1400_MSVR2_DTR : 0));
833 		}
834 		break;
835 
836 	case DMBIS:		/* set bits */
837 		if (cy->cy_clock == CY_CLOCK_60) {
838 			if (!ISSET(tp->t_cflag, CRTSCTS) &&
839 			    (bits & TIOCM_RTS) != 0)
840 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR2,
841 				    CD1400_MSVR2_DTR);
842 			if (bits & TIOCM_DTR)
843 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR1,
844 				    CD1400_MSVR1_RTS);
845 		} else {
846 			if (!ISSET(tp->t_cflag, CRTSCTS) &&
847 			    (bits & TIOCM_RTS) != 0)
848 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR1,
849 				    CD1400_MSVR1_RTS);
850 			if (bits & TIOCM_DTR)
851 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR2,
852 				    CD1400_MSVR2_DTR);
853 		}
854 		break;
855 
856 	case DMBIC:		/* clear bits */
857 		if (cy->cy_clock == CY_CLOCK_60) {
858 			if (!ISSET(tp->t_cflag, CRTSCTS) && (bits & TIOCM_RTS))
859 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR2, 0);
860 			if (bits & TIOCM_DTR)
861 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR1, 0);
862 		} else {
863 			if (!ISSET(tp->t_cflag, CRTSCTS) && (bits & TIOCM_RTS))
864 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR1, 0);
865 			if (bits & TIOCM_DTR)
866 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR2, 0);
867 		}
868 		break;
869 	}
870 	splx(s);
871 	return ((howto == DMGET) ? bits : 0);
872 }
873 
874 /*
875  * Upper-level handler loop (called from timer interrupt?)
876  * This routine is common for multiple cards
877  */
878 void
879 cy_poll(void *arg)
880 {
881 	int card, port;
882 	struct cy_softc *sc;
883 	struct cy_port *cy;
884 	struct tty *tp;
885 	static int counter = 0;
886 #ifdef CY_DEBUG1
887 	int did_something;
888 #endif
889 	int s = spltty();
890 
891 	if (cy_events == 0 && ++counter < 200) {
892 		splx(s);
893 		goto out;
894 	}
895 	cy_events = 0;
896 	splx(s);
897 
898 	for (card = 0; card < cy_cd.cd_ndevs; card++) {
899 		sc = device_lookup(&cy_cd, card);
900 		if (sc == NULL)
901 			continue;
902 
903 #ifdef CY_DEBUG1
904 		sc->sc_poll_count1++;
905 		did_something = 0;
906 #endif
907 
908 		for (port = 0; port < sc->sc_nchannels; port++) {
909 			cy = &sc->sc_ports[port];
910 			if ((tp = cy->cy_tty) == NULL || cy->cy_ibuf == NULL ||
911 			    (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0))
912 				continue;
913 
914 			/*
915 		         * handle received data
916 		         */
917 			while (cy->cy_ibuf_rd_ptr != cy->cy_ibuf_wr_ptr) {
918 				u_char line_stat;
919 				int chr;
920 
921 				line_stat = cy->cy_ibuf_rd_ptr[0];
922 				chr = cy->cy_ibuf_rd_ptr[1];
923 
924 				if (line_stat &
925 				    (CD1400_RDSR_BREAK | CD1400_RDSR_FE))
926 					chr |= TTY_FE;
927 				if (line_stat & CD1400_RDSR_PE)
928 					chr |= TTY_PE;
929 
930 				/*
931 				 * on an overrun error the data is treated as
932 				 * good just as it should be.
933 				 */
934 
935 #ifdef CY_DEBUG
936 				printf("%s: port %d ttyinput 0x%x\n",
937 				    sc->sc_dev.dv_xname, port, chr);
938 #endif
939 
940 				(*tp->t_linesw->l_rint) (chr, tp);
941 
942 				s = spltty();	/* really necessary? */
943 				if ((cy->cy_ibuf_rd_ptr += 2) ==
944 				    cy->cy_ibuf_end)
945 					cy->cy_ibuf_rd_ptr = cy->cy_ibuf;
946 				splx(s);
947 
948 #ifdef CY_DEBUG1
949 				did_something = 1;
950 #endif
951 			}
952 
953 			/*
954 			 * If we don't have any received data in ibuf and
955 			 * CRTSCTS is on and RTS is turned off, it is time to
956 			 * turn RTS back on
957 			 */
958 			if (ISSET(tp->t_cflag, CRTSCTS)) {
959 				/*
960 				 * we can't use cy_modem_control() here as it
961 				 * doesn't change RTS if RTSCTS is on
962 				 */
963 				cd_write_reg(sc, cy->cy_chip, CD1400_CAR,
964 				    port & CD1400_CAR_CHAN);
965 
966 				if (cy->cy_clock == CY_CLOCK_60) {
967 				  if ((cd_read_reg(sc, cy->cy_chip,
968 				    CD1400_MSVR2) & CD1400_MSVR2_DTR) == 0) {
969 					cd_write_reg(sc, cy->cy_chip,
970 					CD1400_MSVR2,CD1400_MSVR2_DTR);
971 #ifdef CY_DEBUG1
972 					did_something = 1;
973 #endif
974 				  }
975 				} else {
976 				  if ((cd_read_reg(sc, cy->cy_chip,
977 				    CD1400_MSVR1) & CD1400_MSVR1_RTS) == 0) {
978 					cd_write_reg(sc, cy->cy_chip,
979 					CD1400_MSVR1,CD1400_MSVR1_RTS);
980 #ifdef CY_DEBUG1
981 					did_something = 1;
982 #endif
983 				  }
984 				}
985 			}
986 
987 			/*
988 		         * handle carrier changes
989 		         */
990 			s = spltty();
991 			if (ISSET(cy->cy_flags, CY_F_CARRIER_CHANGED)) {
992 				int             carrier;
993 
994 				CLR(cy->cy_flags, CY_F_CARRIER_CHANGED);
995 				splx(s);
996 
997 				carrier = ((cy->cy_carrier_stat &
998 				    CD1400_MSVR2_CD) != 0);
999 
1000 #ifdef CY_DEBUG
1001 				printf("cy_poll: carrier change "
1002 				    "(card %d, port %d, carrier %d)\n",
1003 				    card, port, carrier);
1004 #endif
1005 				if (CY_DIALOUT(tp->t_dev) == 0 &&
1006 				    !(*tp->t_linesw->l_modem)(tp, carrier))
1007 					cy_modem_control(sc, cy,
1008 					    TIOCM_DTR, DMBIC);
1009 
1010 #ifdef CY_DEBUG1
1011 				did_something = 1;
1012 #endif
1013 			} else
1014 				splx(s);
1015 
1016 			s = spltty();
1017 			if (ISSET(cy->cy_flags, CY_F_START)) {
1018 				CLR(cy->cy_flags, CY_F_START);
1019 				splx(s);
1020 
1021 				(*tp->t_linesw->l_start) (tp);
1022 
1023 #ifdef CY_DEBUG1
1024 				did_something = 1;
1025 #endif
1026 			} else
1027 				splx(s);
1028 
1029 			/* could move this to even upper level... */
1030 			if (cy->cy_fifo_overruns) {
1031 				cy->cy_fifo_overruns = 0;
1032 				/*
1033 				 * doesn't report overrun count, but
1034 				 * shouldn't really matter
1035 				 */
1036 				log(LOG_WARNING, "%s: port %d fifo overrun\n",
1037 				    sc->sc_dev.dv_xname, port);
1038 			}
1039 			if (cy->cy_ibuf_overruns) {
1040 				cy->cy_ibuf_overruns = 0;
1041 				log(LOG_WARNING, "%s: port %d ibuf overrun\n",
1042 				    sc->sc_dev.dv_xname, port);
1043 			}
1044 		}		/* for(port...) */
1045 #ifdef CY_DEBUG1
1046 		if (did_something && counter >= 200)
1047 			sc->sc_poll_count2++;
1048 #endif
1049 	} /* for(card...) */
1050 
1051 	counter = 0;
1052 
1053 out:
1054 	callout_reset(&cy_poll_callout, 1, cy_poll, NULL);
1055 }
1056 
1057 /*
1058  * hardware interrupt routine
1059  */
1060 int
1061 cy_intr(void *arg)
1062 {
1063 	struct cy_softc *sc = arg;
1064 	struct cy_port *cy;
1065 	int cy_chip, stat;
1066 	int int_serviced = 0;
1067 
1068 	/*
1069 	 * Check interrupt status of each CD1400 chip on this card
1070 	 * (multiple cards cannot share the same interrupt)
1071 	 */
1072 	for (cy_chip = 0; cy_chip < sc->sc_nchips; cy_chip++) {
1073 
1074 		stat = cd_read_reg(sc, cy_chip, CD1400_SVRR);
1075 		if (stat == 0)
1076 			continue;
1077 
1078 		if (ISSET(stat, CD1400_SVRR_RXRDY)) {
1079 			u_char save_car, save_rir, serv_type;
1080 			u_char line_stat, recv_data, n_chars;
1081 			u_char *buf_p;
1082 
1083 			save_rir = cd_read_reg(sc, cy_chip, CD1400_RIR);
1084 			save_car = cd_read_reg(sc, cy_chip, CD1400_CAR);
1085 			/* enter rx service */
1086 			cd_write_reg(sc, cy_chip, CD1400_CAR, save_rir);
1087 
1088 			serv_type = cd_read_reg(sc, cy_chip, CD1400_RIVR);
1089 			cy = &sc->sc_ports[serv_type >> 3];
1090 
1091 #ifdef CY_DEBUG1
1092 			cy->cy_rx_int_count++;
1093 #endif
1094 
1095 			buf_p = cy->cy_ibuf_wr_ptr;
1096 
1097 			if (ISSET(serv_type, CD1400_RIVR_EXCEPTION)) {
1098 				line_stat = cd_read_reg(sc, cy->cy_chip,
1099 				    CD1400_RDSR);
1100 				recv_data = cd_read_reg(sc, cy->cy_chip,
1101 				    CD1400_RDSR);
1102 
1103 				if (cy->cy_tty == NULL ||
1104 				    !ISSET(cy->cy_tty->t_state, TS_ISOPEN))
1105 					goto end_rx_serv;
1106 
1107 #ifdef CY_DEBUG
1108 				printf("%s port %d recv exception, line_stat 0x%x, char 0x%x\n",
1109 				sc->sc_dev.dv_xname, cy->cy_port_num, line_stat, recv_data);
1110 #endif
1111 				if (ISSET(line_stat, CD1400_RDSR_OE))
1112 					cy->cy_fifo_overruns++;
1113 
1114 				*buf_p++ = line_stat;
1115 				*buf_p++ = recv_data;
1116 				if (buf_p == cy->cy_ibuf_end)
1117 					buf_p = cy->cy_ibuf;
1118 
1119 				if (buf_p == cy->cy_ibuf_rd_ptr) {
1120 					if (buf_p == cy->cy_ibuf)
1121 						buf_p = cy->cy_ibuf_end;
1122 					buf_p -= 2;
1123 					cy->cy_ibuf_overruns++;
1124 				}
1125 				cy_events = 1;
1126 			} else {/* no exception, received data OK */
1127 				n_chars = cd_read_reg(sc, cy->cy_chip,
1128 				    CD1400_RDCR);
1129 
1130 				/* If no tty or not open, discard data */
1131 				if (cy->cy_tty == NULL ||
1132 				    !ISSET(cy->cy_tty->t_state, TS_ISOPEN)) {
1133 					while (n_chars--)
1134 						(void)cd_read_reg(sc,
1135 						    cy->cy_chip, CD1400_RDSR);
1136 					goto end_rx_serv;
1137 				}
1138 
1139 #ifdef CY_DEBUG
1140 				printf("%s port %d receive ok %d chars\n",
1141 				    sc->sc_dev.dv_xname, cy->cy_port_num, n_chars);
1142 #endif
1143 				while (n_chars--) {
1144 					*buf_p++ = 0;	/* status: OK */
1145 					/* data byte */
1146 					*buf_p++ = cd_read_reg(sc,
1147 					    cy->cy_chip, CD1400_RDSR);
1148 					if (buf_p == cy->cy_ibuf_end)
1149 						buf_p = cy->cy_ibuf;
1150 					if (buf_p == cy->cy_ibuf_rd_ptr) {
1151 						if (buf_p == cy->cy_ibuf)
1152 							buf_p = cy->cy_ibuf_end;
1153 						buf_p -= 2;
1154 						cy->cy_ibuf_overruns++;
1155 						break;
1156 					}
1157 				}
1158 				cy_events = 1;
1159 			}
1160 
1161 			cy->cy_ibuf_wr_ptr = buf_p;
1162 
1163 			/* RTS handshaking for incoming data */
1164 			if (ISSET(cy->cy_tty->t_cflag, CRTSCTS)) {
1165 				int bf, msvr;
1166 
1167 				bf = buf_p - cy->cy_ibuf_rd_ptr;
1168 				if (bf < 0)
1169 					bf += CY_IBUF_SIZE;
1170 
1171 				if (bf > (CY_IBUF_SIZE / 2)) {
1172 					/* turn RTS off */
1173 					if (cy->cy_clock == CY_CLOCK_60)
1174 						msvr = CD1400_MSVR2;
1175 					else
1176 						msvr = CD1400_MSVR1;
1177 					cd_write_reg(sc, cy->cy_chip, msvr, 0);
1178 				}
1179 			}
1180 
1181 	end_rx_serv:
1182 			/* terminate service context */
1183 			cd_write_reg(sc, cy->cy_chip, CD1400_RIR,
1184 				     save_rir & 0x3f);
1185 			cd_write_reg(sc, cy->cy_chip, CD1400_CAR, save_car);
1186 			int_serviced = 1;
1187 		} /* if (rx_service...) */
1188 		if (ISSET(stat, CD1400_SVRR_MDMCH)) {
1189 			u_char save_car, save_mir, serv_type, modem_stat;
1190 
1191 			save_mir = cd_read_reg(sc, cy_chip, CD1400_MIR);
1192 			save_car = cd_read_reg(sc, cy_chip, CD1400_CAR);
1193 			/* enter modem service */
1194 			cd_write_reg(sc, cy_chip, CD1400_CAR, save_mir);
1195 
1196 			serv_type = cd_read_reg(sc, cy_chip, CD1400_MIVR);
1197 			cy = &sc->sc_ports[serv_type >> 3];
1198 
1199 #ifdef CY_DEBUG1
1200 			cy->cy_modem_int_count++;
1201 #endif
1202 
1203 			modem_stat = cd_read_reg(sc, cy->cy_chip, CD1400_MSVR2);
1204 
1205 #ifdef CY_DEBUG
1206 			printf("%s port %d modem line change, new stat 0x%x\n",
1207 			       sc->sc_dev.dv_xname, cy->cy_port_num, modem_stat);
1208 #endif
1209 			if (ISSET((cy->cy_carrier_stat ^ modem_stat), CD1400_MSVR2_CD)) {
1210 				SET(cy->cy_flags, CY_F_CARRIER_CHANGED);
1211 				cy_events = 1;
1212 			}
1213 			cy->cy_carrier_stat = modem_stat;
1214 
1215 			/* terminate service context */
1216 			cd_write_reg(sc, cy->cy_chip, CD1400_MIR, save_mir & 0x3f);
1217 			cd_write_reg(sc, cy->cy_chip, CD1400_CAR, save_car);
1218 			int_serviced = 1;
1219 		} /* if (modem_service...) */
1220 		if (ISSET(stat, CD1400_SVRR_TXRDY)) {
1221 			u_char          save_car, save_tir, serv_type,
1222 			                count, ch;
1223 			struct tty     *tp;
1224 
1225 			save_tir = cd_read_reg(sc, cy_chip, CD1400_TIR);
1226 			save_car = cd_read_reg(sc, cy_chip, CD1400_CAR);
1227 			/* enter tx service */
1228 			cd_write_reg(sc, cy_chip, CD1400_CAR, save_tir);
1229 
1230 			serv_type = cd_read_reg(sc, cy_chip, CD1400_TIVR);
1231 			cy = &sc->sc_ports[serv_type >> 3];
1232 
1233 #ifdef CY_DEBUG1
1234 			cy->cy_tx_int_count++;
1235 #endif
1236 #ifdef CY_DEBUG
1237 			printf("%s port %d tx service\n", sc->sc_dev.dv_xname,
1238 			    cy->cy_port_num);
1239 #endif
1240 
1241 			/* stop transmitting if no tty or CY_F_STOP set */
1242 			tp = cy->cy_tty;
1243 			if (tp == NULL || ISSET(cy->cy_flags, CY_F_STOP))
1244 				goto txdone;
1245 
1246 			count = 0;
1247 			if (ISSET(cy->cy_flags, CY_F_SEND_NUL)) {
1248 				cd_write_reg(sc, cy->cy_chip, CD1400_TDR, 0);
1249 				cd_write_reg(sc, cy->cy_chip, CD1400_TDR, 0);
1250 				count += 2;
1251 				CLR(cy->cy_flags, CY_F_SEND_NUL);
1252 			}
1253 			if (tp->t_outq.c_cc > 0) {
1254 				SET(tp->t_state, TS_BUSY);
1255 				while (tp->t_outq.c_cc > 0 &&
1256 				    count < CD1400_TX_FIFO_SIZE) {
1257 					ch = getc(&tp->t_outq);
1258 					/*
1259 					 * remember to double NUL characters
1260 					 * because embedded transmit commands
1261 					 * are enabled
1262 					 */
1263 					if (ch == 0) {
1264 						if (count >= CD1400_TX_FIFO_SIZE - 2) {
1265 							SET(cy->cy_flags, CY_F_SEND_NUL);
1266 							break;
1267 						}
1268 						cd_write_reg(sc, cy->cy_chip,
1269 						    CD1400_TDR, ch);
1270 						count++;
1271 					}
1272 					cd_write_reg(sc, cy->cy_chip,
1273 					    CD1400_TDR, ch);
1274 					count++;
1275 				}
1276 			} else {
1277 				/*
1278 				 * no data to send -- check if we should
1279 				 * start/stop a break
1280 				 */
1281 				/*
1282 				 * XXX does this cause too much delay before
1283 				 * breaks?
1284 				 */
1285 				if (ISSET(cy->cy_flags, CY_F_START_BREAK)) {
1286 					cd_write_reg(sc, cy->cy_chip,
1287 					    CD1400_TDR, 0);
1288 					cd_write_reg(sc, cy->cy_chip,
1289 					    CD1400_TDR, 0x81);
1290 					CLR(cy->cy_flags, CY_F_START_BREAK);
1291 				}
1292 				if (ISSET(cy->cy_flags, CY_F_END_BREAK)) {
1293 					cd_write_reg(sc, cy->cy_chip,
1294 					    CD1400_TDR, 0);
1295 					cd_write_reg(sc, cy->cy_chip,
1296 					    CD1400_TDR, 0x83);
1297 					CLR(cy->cy_flags, CY_F_END_BREAK);
1298 				}
1299 			}
1300 
1301 			if (tp->t_outq.c_cc == 0) {
1302 		txdone:
1303 				/*
1304 				 * No data to send or requested to stop.
1305 				 * Disable transmit interrupt
1306 				 */
1307 				cd_write_reg(sc, cy->cy_chip, CD1400_SRER,
1308 				     cd_read_reg(sc, cy->cy_chip, CD1400_SRER)
1309 				     & ~CD1400_SRER_TXRDY);
1310 				CLR(cy->cy_flags, CY_F_STOP);
1311 				CLR(tp->t_state, TS_BUSY);
1312 			}
1313 			if (tp->t_outq.c_cc <= tp->t_lowat) {
1314 				SET(cy->cy_flags, CY_F_START);
1315 				cy_events = 1;
1316 			}
1317 			/* terminate service context */
1318 			cd_write_reg(sc, cy->cy_chip, CD1400_TIR, save_tir & 0x3f);
1319 			cd_write_reg(sc, cy->cy_chip, CD1400_CAR, save_car);
1320 			int_serviced = 1;
1321 		}		/* if (tx_service...) */
1322 	}			/* for(...all CD1400s on a card) */
1323 
1324 	/* ensure an edge for next interrupt */
1325 	bus_space_write_1(sc->sc_memt, sc->sc_bsh,
1326 			CY_CLEAR_INTR << sc->sc_bustype, 0);
1327 	return int_serviced;
1328 }
1329 
1330 /*
1331  * subroutine to enable CD1400 transmitter
1332  */
1333 void
1334 cy_enable_transmitter(struct cy_softc *sc, struct cy_port *cy)
1335 {
1336 	int s = spltty();
1337 	cd_write_reg(sc, cy->cy_chip, CD1400_CAR,
1338 	    cy->cy_port_num & CD1400_CAR_CHAN);
1339 	cd_write_reg(sc, cy->cy_chip, CD1400_SRER,
1340 	    cd_read_reg(sc, cy->cy_chip, CD1400_SRER) | CD1400_SRER_TXRDY);
1341 	splx(s);
1342 }
1343 
1344 /*
1345  * Execute a CD1400 channel command
1346  */
1347 void
1348 cd1400_channel_cmd(struct cy_softc *sc, struct cy_port *cy, int cmd)
1349 {
1350 	u_int waitcnt = 5 * 8 * 1024;	/* approx 5 ms */
1351 
1352 #ifdef CY_DEBUG
1353 	printf("c1400_channel_cmd cy %p command 0x%x\n", cy, cmd);
1354 #endif
1355 
1356 	/* wait until cd1400 is ready to process a new command */
1357 	while (cd_read_reg(sc, cy->cy_chip, CD1400_CCR) != 0 && waitcnt-- > 0);
1358 
1359 	if (waitcnt == 0)
1360 		log(LOG_ERR, "%s: channel command timeout\n",
1361 		    sc->sc_dev.dv_xname);
1362 
1363 	cd_write_reg(sc, cy->cy_chip, CD1400_CCR, cmd);
1364 }
1365 
1366 /*
1367  * Compute clock option register and baud rate register values
1368  * for a given speed. Return 0 on success, -1 on failure.
1369  *
1370  * The error between requested and actual speed seems
1371  * to be well within allowed limits (less than 3%)
1372  * with every speed value between 50 and 150000 bps.
1373  */
1374 int
1375 cy_speed(speed_t speed, int *cor, int *bpr, int cy_clock)
1376 {
1377 	int c, co, br;
1378 
1379 	if (speed < 50 || speed > 150000)
1380 		return -1;
1381 
1382 	for (c = 0, co = 8; co <= 2048; co <<= 2, c++) {
1383 		br = (cy_clock + (co * speed) / 2) / (co * speed);
1384 		if (br < 0x100) {
1385 			*bpr = br;
1386 			*cor = c;
1387 			return 0;
1388 		}
1389 	}
1390 
1391 	return -1;
1392 }
1393