xref: /netbsd-src/sys/dev/ic/cy.c (revision 06be8101a16cc95f40783b3cb7afd12112103a9a)
1 /*	$NetBSD: cy.c,v 1.24 2001/11/13 13:14:36 lukem 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 1.24 2001/11/13 13:14:36 lukem Exp $");
20 
21 #include <sys/types.h>
22 #include <sys/param.h>
23 #include <sys/ioctl.h>
24 #include <sys/syslog.h>
25 #include <sys/fcntl.h>
26 #include <sys/tty.h>
27 #include <sys/proc.h>
28 #include <sys/conf.h>
29 #include <sys/user.h>
30 #include <sys/ioctl.h>
31 #include <sys/select.h>
32 #include <sys/device.h>
33 #include <sys/malloc.h>
34 #include <sys/systm.h>
35 #include <sys/callout.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 /* Macros to clear/set/test flags. */
44 #define	SET(t, f)	(t) |= (f)
45 #define	CLR(t, f)	(t) &= ~(f)
46 #define	ISSET(t, f)	((t) & (f))
47 
48 int	cyparam(struct tty *, struct termios *);
49 void	cystart(struct tty *);
50 void	cy_poll(void *);
51 int	cy_modem_control(struct cy_softc *, struct cy_port *, int, int);
52 void	cy_enable_transmitter(struct cy_softc *, struct cy_port *);
53 void	cd1400_channel_cmd(struct cy_softc *, struct cy_port *, int);
54 int	cy_speed(speed_t, int *, int *, int);
55 
56 extern struct cfdriver cy_cd;
57 
58 static int      cy_open = 0;
59 static int      cy_events = 0;
60 
61 int	cy_attached_ttys;
62 
63 cdev_decl(cy);
64 
65 struct callout cy_poll_callout = CALLOUT_INITIALIZER;
66 
67 /*
68  * Common probe routine
69  */
70 int
71 cy_find(struct cy_softc *sc)
72 {
73 	int cy_chip, chip;
74 	u_char firmware_ver;
75 	bus_space_tag_t tag = sc->sc_memt;
76 	bus_space_handle_t bsh = sc->sc_bsh;
77 	int bustype = sc->sc_bustype;
78 
79 	/* Cyclom card hardware reset */
80 	bus_space_write_1(tag, bsh, CY16_RESET << bustype, 0);
81 	DELAY(500);		/* wait for reset to complete */
82 	bus_space_write_1(tag, bsh, CY_CLEAR_INTR << bustype, 0);
83 
84 #ifdef CY_DEBUG
85 	printf("cy: card reset done\n");
86 #endif
87 	sc->sc_nchips = 0;
88 
89 	for (cy_chip = 0, chip = 0; cy_chip < CY_MAX_CD1400s;
90 	    cy_chip++, chip += (CY_CD1400_MEMSPACING << bustype)) {
91 		int i;
92 
93 		/*
94 		 * the last 4 nchips are 'interleaved' with the first 4 on
95 		 * 32-port boards
96 		 */
97 		if (cy_chip == 4)
98 			chip -= (CY32_ADDR_FIX << bustype);
99 
100 #ifdef CY_DEBUG
101 		printf("%s probe chip %d offset 0x%x ... ",
102 		    sc->sc_dev.dv_xname, cy_chip, chip);
103 #endif
104 
105 		/* wait until the chip is ready for command */
106 		DELAY(1000);
107 		if (bus_space_read_1(tag, bsh, chip +
108 		    ((CD1400_CCR << 1) << bustype)) != 0) {
109 #ifdef CY_DEBUG
110 			printf("not ready for command\n");
111 #endif
112 			break;
113 		}
114 		/* clear the firmware version reg. */
115 		bus_space_write_1(tag, bsh, chip +
116 		    ((CD1400_GFRCR << 1) << bustype), 0);
117 
118 		/*
119 	         * On Cyclom-16 references to non-existent chip 4
120 	         * actually access chip 0 (address line 9 not decoded).
121 	         * Here we check if the clearing of chip 4 GFRCR actually
122 	         * cleared chip 0 GFRCR. In that case we have a 16 port card.
123 	         */
124 		if (cy_chip == 4 &&
125 		    bus_space_read_1(tag, bsh, /* off for chip 0 (0) + */
126 		       ((CD1400_GFRCR << 1) << bustype)) == 0)
127 			break;
128 
129 		/* reset the chip */
130 		bus_space_write_1(tag, bsh, chip +
131 		    ((CD1400_CCR << 1) << bustype),
132 		    CD1400_CCR_CMDRESET | CD1400_CCR_FULLRESET);
133 
134 		/* wait for the chip to initialize itself */
135 		for (i = 0; i < 200; i++) {
136 			DELAY(50);
137 			firmware_ver = bus_space_read_1(tag, bsh, chip +
138 			    ((CD1400_GFRCR << 1) << bustype));
139 			if ((firmware_ver & 0xf0) == 0x40) /* found a CD1400 */
140 				break;
141 		}
142 #ifdef CY_DEBUG
143 		printf("firmware version 0x%x\n", firmware_ver);
144 #endif
145 
146 		if ((firmware_ver & 0xf0) != 0x40)
147 			break;
148 
149 		/* firmware version OK, CD1400 found */
150 		sc->sc_nchips++;
151 	}
152 
153 	if (sc->sc_nchips == 0) {
154 #ifdef CY_DEBUG
155 		printf("no CD1400s found\n");
156 #endif
157 		return 0;
158 	}
159 #ifdef CY_DEBUG
160 	printf("found %d CD1400s\n", sc->sc_nchips);
161 #endif
162 
163 	return 1;
164 }
165 
166 void
167 cy_attach(struct cy_softc *sc)
168 {
169 	int port, cy_chip, num_chips, cdu, chip;
170 	int cy_clock;
171 
172 	num_chips = sc->sc_nchips;
173 	if (num_chips == 0)
174 		return;
175 
176 	memset(sc->sc_ports, 0, sizeof(sc->sc_ports));
177 
178 	port = 0;
179 	for (cy_chip = 0, chip = 0; cy_chip < num_chips; cy_chip++,
180 	    chip += (CY_CD1400_MEMSPACING << sc->sc_bustype)) {
181 
182 		if (cy_chip == 4)
183 			chip -= (CY32_ADDR_FIX << sc->sc_bustype);
184 
185 #ifdef CY_DEBUG
186 		printf("attach CD1400 #%d offset 0x%x\n", cy_chip, chip);
187 #endif
188 		sc->sc_cd1400_offs[cy_chip] = chip;
189 
190 		/*
191 		 * configure port 0 as serial port (should already be after
192 		 * reset)
193 		 */
194 		cd_write_reg(sc, cy_chip, CD1400_GCR, 0);
195 
196 		if (cd_read_reg(sc, cy_chip, CD1400_GFRCR) <= 0x46)
197 			cy_clock = CY_CLOCK;
198 		else
199 			cy_clock = CY_CLOCK_60;
200 
201 		/* set up a receive timeout period (1ms) */
202 		cd_write_reg(sc, cy_chip, CD1400_PPR,
203 		    (cy_clock / CD1400_PPR_PRESCALER / 1000) + 1);
204 
205 		for (cdu = 0; cdu < CD1400_NO_OF_CHANNELS; cdu++) {
206 			sc->sc_ports[port].cy_softc = sc;
207 			sc->sc_ports[port].cy_port_num = port;
208 			sc->sc_ports[port].cy_chip = cy_chip;
209 			sc->sc_ports[port].cy_clock = cy_clock;
210 
211 			/* should we initialize anything else here? */
212 			port++;
213 		} /* for(each port on one CD1400...) */
214 
215 	} /* for(each CD1400 on a card... ) */
216 
217 	sc->sc_nchannels = port;
218 
219 	printf("%s: %d channels (ttyCY%03d..ttyCY%03d)\n",
220 	    sc->sc_dev.dv_xname, sc->sc_nchannels, cy_attached_ttys,
221 	    cy_attached_ttys + (sc->sc_nchannels - 1));
222 
223 	cy_attached_ttys += sc->sc_nchannels;
224 
225 	/* ensure an edge for the next interrupt */
226 	bus_space_write_1(sc->sc_memt, sc->sc_bsh,
227 	    CY_CLEAR_INTR << sc->sc_bustype, 0);
228 }
229 
230 #define	CYDIALOUT_MASK		0x80000
231 #define	CY_DIALOUT(dev)		(minor(dev) & CYDIALOUT_MASK)
232 
233 #define	CY_PORT(dev)		cy_getport((dev))
234 #define	CY_BOARD(cy)		((cy)->cy_softc)
235 
236 static struct cy_port *
237 cy_getport(dev_t dev)
238 {
239 	int i, j, k, u = minor(dev) & ~CYDIALOUT_MASK;
240 	struct cy_softc *sc;
241 
242 	for (i = 0, j = 0; i < cy_cd.cd_ndevs; i++) {
243 		k = j;
244 		sc = device_lookup(&cy_cd, i);
245 		if (sc == NULL)
246 			continue;
247 		if (sc->sc_nchannels == 0)
248 			continue;
249 		j += sc->sc_nchannels;
250 		if (j > u)
251 			break;
252 	}
253 
254 	if (i == cy_cd.cd_ndevs)
255 		return (NULL);
256 	else
257 		return (&sc->sc_ports[u - k]);
258 }
259 
260 /*
261  * open routine. returns zero if successfull, else error code
262  */
263 int
264 cyopen(dev_t dev, int flag, int mode, struct proc *p)
265 {
266 	struct cy_softc *sc;
267 	struct cy_port *cy;
268 	struct tty *tp;
269 	int s, error;
270 
271 	cy = CY_PORT(dev);
272 	if (cy == NULL)
273 		return (ENXIO);
274 	sc = CY_BOARD(cy);
275 
276 	s = spltty();
277 	if (cy->cy_tty == NULL) {
278 		if ((cy->cy_tty = ttymalloc()) == NULL) {
279 			splx(s);
280 			printf("%s: port %d: can't allocate tty\n",
281 			    sc->sc_dev.dv_xname, cy->cy_port_num);
282 			return (ENOMEM);
283 		}
284 		tty_attach(cy->cy_tty);
285 	}
286 	splx(s);
287 
288 	tp = cy->cy_tty;
289 	tp->t_oproc = cystart;
290 	tp->t_param = cyparam;
291 	tp->t_dev = dev;
292 
293 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
294 		ttychars(tp);
295 		tp->t_iflag = TTYDEF_IFLAG;
296 		tp->t_oflag = TTYDEF_OFLAG;
297 		tp->t_cflag = TTYDEF_CFLAG;
298 		if (ISSET(cy->cy_openflags, TIOCFLAG_CLOCAL))
299 			SET(tp->t_cflag, CLOCAL);
300 		if (ISSET(cy->cy_openflags, TIOCFLAG_CRTSCTS))
301 			SET(tp->t_cflag, CRTSCTS);
302 		if (ISSET(cy->cy_openflags, TIOCFLAG_MDMBUF))
303 			SET(tp->t_cflag, MDMBUF);
304 		tp->t_lflag = TTYDEF_LFLAG;
305 		tp->t_ispeed = tp->t_ospeed = TTYDEF_SPEED;
306 
307 		s = spltty();
308 
309 		/*
310 		 * Allocate input ring buffer if we don't already have one
311 		 */
312 		if (cy->cy_ibuf == NULL) {
313 			cy->cy_ibuf = malloc(CY_IBUF_SIZE, M_DEVBUF, M_NOWAIT);
314 			if (cy->cy_ibuf == NULL) {
315 				printf("%s: port %d: can't allocate input buffer\n",
316 				       sc->sc_dev.dv_xname, cy->cy_port_num);
317 				splx(s);
318 				return ENOMEM;
319 			}
320 			cy->cy_ibuf_end = cy->cy_ibuf + CY_IBUF_SIZE;
321 		}
322 		/* mark the ring buffer as empty */
323 		cy->cy_ibuf_rd_ptr = cy->cy_ibuf_wr_ptr = cy->cy_ibuf;
324 
325 		/* select CD1400 channel */
326 		cd_write_reg(sc, cy->cy_chip, CD1400_CAR,
327 		    cy->cy_port_num & CD1400_CAR_CHAN);
328 		/* reset the channel */
329 		cd1400_channel_cmd(sc, cy, CD1400_CCR_CMDRESET);
330 		/* encode unit (port) number in LIVR */
331 		/* there is just enough space for 5 bits (32 ports) */
332 		cd_write_reg(sc, cy->cy_chip, CD1400_LIVR,
333 		    cy->cy_port_num << 3);
334 
335 		cy->cy_channel_control = 0;
336 
337 		/* hmm... need spltty() here? */
338 		if (cy_open == 0) {
339 			cy_open = 1;
340 			callout_reset(&cy_poll_callout, 1, cy_poll, NULL);
341 		}
342 		/* this sets parameters and raises DTR */
343 		cyparam(tp, &tp->t_termios);
344 
345 		ttsetwater(tp);
346 
347 		/* raise RTS too */
348 		cy_modem_control(sc, cy, TIOCM_RTS, DMBIS);
349 
350 		cy->cy_carrier_stat =
351 			cd_read_reg(sc, cy->cy_chip, CD1400_MSVR2);
352 
353 		/* enable receiver and modem change interrupts */
354 		cd_write_reg(sc, cy->cy_chip, CD1400_SRER,
355 		    CD1400_SRER_MDMCH | CD1400_SRER_RXDATA);
356 
357 		if (CY_DIALOUT(dev) ||
358 		    ISSET(cy->cy_openflags, TIOCFLAG_SOFTCAR) ||
359 		    ISSET(tp->t_cflag, MDMBUF) ||
360 		    ISSET(cy->cy_carrier_stat, CD1400_MSVR2_CD))
361 			SET(tp->t_state, TS_CARR_ON);
362 		else
363 			CLR(tp->t_state, TS_CARR_ON);
364 	} else if (ISSET(tp->t_state, TS_XCLUDE) && p->p_ucred->cr_uid != 0) {
365 		return EBUSY;
366 	} else {
367 		s = spltty();
368 	}
369 
370 	/* wait for carrier if necessary */
371 	if (!ISSET(flag, O_NONBLOCK)) {
372 		while (!ISSET(tp->t_cflag, CLOCAL) &&
373 		    !ISSET(tp->t_state, TS_CARR_ON)) {
374 			tp->t_wopen++;
375 			error = ttysleep(tp, &tp->t_rawq, TTIPRI | PCATCH,
376 			    "cydcd", 0);
377 			tp->t_wopen--;
378 			if (error != 0) {
379 				splx(s);
380 				return error;
381 			}
382 		}
383 	}
384 	splx(s);
385 
386 	return (*tp->t_linesw->l_open) (dev, tp);
387 }
388 
389 /*
390  * close routine. returns zero if successfull, else error code
391  */
392 int
393 cyclose(dev_t dev, int flag, int mode, struct proc *p)
394 {
395 	struct cy_softc *sc;
396 	struct cy_port *cy;
397 	struct tty *tp;
398 	int s;
399 
400 	cy = CY_PORT(dev);
401 	sc = CY_BOARD(cy);
402 	tp = cy->cy_tty;
403 
404 	(*tp->t_linesw->l_close) (tp, flag);
405 	s = spltty();
406 
407 	if (ISSET(tp->t_cflag, HUPCL) &&
408 	    !ISSET(cy->cy_openflags, TIOCFLAG_SOFTCAR)) {
409 		/*
410 		 * drop DTR and RTS (should we wait for output buffer to
411 		 * become empty first?)
412 		 */
413 		cy_modem_control(sc, cy, 0, DMSET);
414 	}
415 	/*
416 	 * XXX should we disable modem change and
417 	 * receive interrupts here or somewhere ?
418 	 */
419 	CLR(tp->t_state, TS_BUSY | TS_FLUSH);
420 
421 	splx(s);
422 	ttyclose(tp);
423 
424 	return 0;
425 }
426 
427 /*
428  * Read routine
429  */
430 int
431 cyread(dev_t dev, struct uio *uio, int flag)
432 {
433 	struct cy_port *cy;
434 	struct tty *tp;
435 
436 	cy = CY_PORT(dev);
437 	tp = cy->cy_tty;
438 
439 	return ((*tp->t_linesw->l_read)(tp, uio, flag));
440 }
441 
442 /*
443  * Write routine
444  */
445 int
446 cywrite(dev_t dev, struct uio *uio, int flag)
447 {
448 	struct cy_port *cy;
449 	struct tty *tp;
450 
451 	cy = CY_PORT(dev);
452 	tp = cy->cy_tty;
453 
454 	return ((*tp->t_linesw->l_write)(tp, uio, flag));
455 }
456 
457 /*
458  * Poll routine
459  */
460 int
461 cypoll(dev, events, p)
462 	dev_t dev;
463 	int events;
464 	struct proc *p;
465 {
466 	struct cy_port *cy;
467 	struct tty *tp;
468 
469 	cy = CY_PORT(dev);
470 	tp = cy->cy_tty;
471 
472 	return ((*tp->t_linesw->l_poll)(tp, events, p));
473 }
474 
475 /*
476  * return tty pointer
477  */
478 struct tty *
479 cytty(dev_t dev)
480 {
481 	struct cy_port *cy;
482 
483 	cy = CY_PORT(dev);
484 
485 	return (cy->cy_tty);
486 }
487 
488 /*
489  * ioctl routine
490  */
491 int
492 cyioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct proc *p)
493 {
494 	struct cy_softc *sc;
495 	struct cy_port *cy;
496 	struct tty *tp;
497 	int error;
498 
499 	cy = CY_PORT(dev);
500 	sc = CY_BOARD(cy);
501 	tp = cy->cy_tty;
502 
503 	error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, p);
504 	if (error >= 0)
505 		return error;
506 
507 	error = ttioctl(tp, cmd, data, flag, p);
508 	if (error >= 0)
509 		return error;
510 
511 	/* XXX should not allow dropping DTR when dialin? */
512 
513 	switch (cmd) {
514 	case TIOCSBRK:		/* start break */
515 		SET(cy->cy_flags, CY_F_START_BREAK);
516 		cy_enable_transmitter(sc, cy);
517 		break;
518 
519 	case TIOCCBRK:		/* stop break */
520 		SET(cy->cy_flags, CY_F_END_BREAK);
521 		cy_enable_transmitter(sc, cy);
522 		break;
523 
524 	case TIOCSDTR:		/* DTR on */
525 		cy_modem_control(sc, cy, TIOCM_DTR, DMBIS);
526 		break;
527 
528 	case TIOCCDTR:		/* DTR off */
529 		cy_modem_control(sc, cy, TIOCM_DTR, DMBIC);
530 		break;
531 
532 	case TIOCMSET:		/* set new modem control line values */
533 		cy_modem_control(sc, cy, *((int *) data), DMSET);
534 		break;
535 
536 	case TIOCMBIS:		/* turn modem control bits on */
537 		cy_modem_control(sc, cy, *((int *) data), DMBIS);
538 		break;
539 
540 	case TIOCMBIC:		/* turn modem control bits off */
541 		cy_modem_control(sc, cy, *((int *) data), DMBIC);
542 		break;
543 
544 	case TIOCMGET:		/* get modem control/status line state */
545 		*((int *) data) = cy_modem_control(sc, cy, 0, DMGET);
546 		break;
547 
548 	case TIOCGFLAGS:
549 		*((int *) data) = cy->cy_openflags |
550 			(CY_DIALOUT(dev) ? TIOCFLAG_SOFTCAR : 0);
551 		break;
552 
553 	case TIOCSFLAGS:
554 		error = suser(p->p_ucred, &p->p_acflag);
555 		if (error != 0)
556 			return EPERM;
557 
558 		cy->cy_openflags = *((int *) data) &
559 		    (TIOCFLAG_SOFTCAR | TIOCFLAG_CLOCAL |
560 		     TIOCFLAG_CRTSCTS | TIOCFLAG_MDMBUF);
561 		break;
562 
563 	default:
564 		return ENOTTY;
565 	}
566 
567 	return 0;
568 }
569 
570 /*
571  * start output
572  */
573 void
574 cystart(struct tty *tp)
575 {
576 	struct cy_softc *sc;
577 	struct cy_port *cy;
578 	int s;
579 
580 	cy = CY_PORT(tp->t_dev);
581 	sc = cy->cy_softc;
582 
583 	s = spltty();
584 
585 #ifdef CY_DEBUG1
586 	cy->cy_start_count++;
587 #endif
588 
589 	if (!ISSET(tp->t_state, TS_TTSTOP | TS_TIMEOUT | TS_BUSY)) {
590 		if (tp->t_outq.c_cc <= tp->t_lowat) {
591 			if (ISSET(tp->t_state, TS_ASLEEP)) {
592 				CLR(tp->t_state, TS_ASLEEP);
593 				wakeup(&tp->t_outq);
594 			}
595 			selwakeup(&tp->t_wsel);
596 
597 			if (tp->t_outq.c_cc == 0)
598 				goto out;
599 		}
600 		SET(tp->t_state, TS_BUSY);
601 		cy_enable_transmitter(sc, cy);
602 	}
603 out:
604 
605 	splx(s);
606 }
607 
608 /*
609  * stop output
610  */
611 void
612 cystop(struct tty *tp, int flag)
613 {
614 	struct cy_port *cy;
615 	int s;
616 
617 	cy = CY_PORT(tp->t_dev);
618 
619 	s = spltty();
620 	if (ISSET(tp->t_state, TS_BUSY)) {
621 		if (!ISSET(tp->t_state, TS_TTSTOP))
622 			SET(tp->t_state, TS_FLUSH);
623 
624 		/*
625 		 * the transmit interrupt routine will disable transmit when it
626 		 * notices that CY_F_STOP has been set.
627 		 */
628 		SET(cy->cy_flags, CY_F_STOP);
629 	}
630 	splx(s);
631 }
632 
633 /*
634  * parameter setting routine.
635  * returns 0 if successfull, else returns error code
636  */
637 int
638 cyparam(struct tty *tp, struct termios *t)
639 {
640 	struct cy_softc *sc;
641 	struct cy_port *cy;
642 	int ibpr, obpr, i_clk_opt, o_clk_opt, s, opt;
643 
644 	cy = CY_PORT(tp->t_dev);
645 	sc = CY_BOARD(cy);
646 
647 	if (t->c_ospeed != 0 && cy_speed(t->c_ospeed, &o_clk_opt, &obpr, cy->cy_clock) < 0)
648 		return EINVAL;
649 
650 	if (t->c_ispeed != 0 && cy_speed(t->c_ispeed, &i_clk_opt, &ibpr, cy->cy_clock) < 0)
651 		return EINVAL;
652 
653 	s = spltty();
654 
655 	/* hang up the line is ospeed is zero, else turn DTR on */
656 	cy_modem_control(sc, cy, TIOCM_DTR, (t->c_ospeed == 0 ? DMBIC : DMBIS));
657 
658 	/* channel was selected by the above call to cy_modem_control() */
659 #if 0
660 	cd_write_reg(sc, cy->cy_chip, CD1400_CAR, port & CD1400_CAR_CHAN);
661 #endif
662 
663 	/* set transmit speed */
664 	if (t->c_ospeed != 0) {
665 		cd_write_reg(sc, cy->cy_chip, CD1400_TCOR, o_clk_opt);
666 		cd_write_reg(sc, cy->cy_chip, CD1400_TBPR, obpr);
667 	}
668 	/* set receive speed */
669 	if (t->c_ispeed != 0) {
670 		cd_write_reg(sc, cy->cy_chip, CD1400_RCOR, i_clk_opt);
671 		cd_write_reg(sc, cy->cy_chip, CD1400_RBPR, ibpr);
672 	}
673 	opt = CD1400_CCR_CMDCHANCTL | CD1400_CCR_XMTEN
674 		| (ISSET(t->c_cflag, CREAD) ? CD1400_CCR_RCVEN : CD1400_CCR_RCVDIS);
675 
676 	if (opt != cy->cy_channel_control) {
677 		cy->cy_channel_control = opt;
678 		cd1400_channel_cmd(sc, cy, opt);
679 	}
680 	/* compute COR1 contents */
681 	opt = 0;
682 	if (ISSET(t->c_cflag, PARENB)) {
683 		if (ISSET(t->c_cflag, PARODD))
684 			opt |= CD1400_COR1_PARODD;
685 		opt |= CD1400_COR1_PARNORMAL;
686 	}
687 	if (!ISSET(t->c_iflag, INPCK))
688 		opt |= CD1400_COR1_NOINPCK;	/* no parity checking */
689 
690 	if (ISSET(t->c_cflag, CSTOPB))
691 		opt |= CD1400_COR1_STOP2;
692 
693 	switch (t->c_cflag & CSIZE) {
694 	case CS5:
695 		opt |= CD1400_COR1_CS5;
696 		break;
697 
698 	case CS6:
699 		opt |= CD1400_COR1_CS6;
700 		break;
701 
702 	case CS7:
703 		opt |= CD1400_COR1_CS7;
704 		break;
705 
706 	default:
707 		opt |= CD1400_COR1_CS8;
708 		break;
709 	}
710 
711 	cd_write_reg(sc, cy->cy_chip, CD1400_COR1, opt);
712 
713 #ifdef CY_DEBUG
714 	printf("cor1 = 0x%x...", opt);
715 #endif
716 
717 	/*
718 	 * use the CD1400 automatic CTS flow control if CRTSCTS is set
719 	 *
720 	 * CD1400_COR2_ETC is used because breaks are generated with
721 	 * embedded transmit commands
722 	 */
723 	cd_write_reg(sc, cy->cy_chip, CD1400_COR2,
724 		     CD1400_COR2_ETC |
725 		 (ISSET(t->c_cflag, CRTSCTS) ? CD1400_COR2_CCTS_OFLOW : 0));
726 
727 	cd_write_reg(sc, cy->cy_chip, CD1400_COR3, CY_RX_FIFO_THRESHOLD);
728 
729 	cd1400_channel_cmd(sc, cy, CD1400_CCR_CMDCORCHG |
730 	    CD1400_CCR_COR1 | CD1400_CCR_COR2 | CD1400_CCR_COR3);
731 
732 	cd_write_reg(sc, cy->cy_chip, CD1400_COR4, CD1400_COR4_PFO_EXCEPTION);
733 	cd_write_reg(sc, cy->cy_chip, CD1400_COR5, 0);
734 
735 	/*
736          * set modem change option registers to generate interrupts
737          * on carrier detect changes.
738          *
739          * if hardware RTS handshaking is used
740          * also set the handshaking threshold.
741          */
742 	if (cy->cy_clock == CY_CLOCK_60) {
743 	   cd_write_reg(sc, cy->cy_chip, CD1400_MCOR1, CD1400_MCOR1_CDzd |
744     	      (ISSET(t->c_cflag, CRTSCTS) ? CY_RX_DTR_THRESHOLD : 0));
745 	} else {
746 	   cd_write_reg(sc, cy->cy_chip, CD1400_MCOR1, CD1400_MCOR1_CDzd);
747 	}
748 
749 	cd_write_reg(sc, cy->cy_chip, CD1400_MCOR2, CD1400_MCOR2_CDod);
750 
751 	/*
752          * set receive timeout to approx. 2ms
753          * could use more complex logic here...
754          * (but is it actually needed or even useful?)
755          */
756 	cd_write_reg(sc, cy->cy_chip, CD1400_RTPR, 2);
757 
758 	/*
759          * should do anything else here?
760          * XXX check MDMBUF handshaking like in com.c?
761          */
762 
763 	splx(s);
764 	return 0;
765 }
766 
767 /*
768  * set/get modem line status
769  *
770  * bits can be: TIOCM_DTR, TIOCM_RTS, TIOCM_CTS, TIOCM_CD, TIOCM_RI, TIOCM_DSR
771  */
772 int
773 cy_modem_control(struct cy_softc *sc, struct cy_port *cy, int bits, int howto)
774 {
775 	struct tty *tp = cy->cy_tty;
776 	int s, msvr;
777 
778 	s = spltty();
779 
780 	/* select channel */
781 	cd_write_reg(sc, cy->cy_chip, CD1400_CAR,
782 	    cy->cy_port_num & CD1400_CAR_CHAN);
783 
784 	/* Does not manipulate RTS if it is used for flow control. */
785 	switch (howto) {
786 	case DMGET:
787 		bits = 0;
788 		if (cy->cy_channel_control & CD1400_CCR_RCVEN)
789 			bits |= TIOCM_LE;
790 		msvr = cd_read_reg(sc, cy->cy_chip, CD1400_MSVR2);
791 		if (cy->cy_clock == CY_CLOCK_60) {
792 			if (cd_read_reg(sc, cy->cy_chip, CD1400_MSVR1) &
793 		    		CD1400_MSVR1_RTS)
794 				bits |= TIOCM_DTR;
795 			if (msvr & CD1400_MSVR2_DTR)
796 				bits |= TIOCM_RTS;
797 		} else {
798 			if (cd_read_reg(sc, cy->cy_chip, CD1400_MSVR1) &
799 			    CD1400_MSVR1_RTS)
800 				bits |= TIOCM_RTS;
801 			if (msvr & CD1400_MSVR2_DTR)
802 				bits |= TIOCM_DTR;
803 		}
804 		if (msvr & CD1400_MSVR2_CTS)
805 			bits |= TIOCM_CTS;
806 		if (msvr & CD1400_MSVR2_CD)
807 			bits |= TIOCM_CD;
808 		/* Not connected on some Cyclom-Y boards? */
809 		if (msvr & CD1400_MSVR2_DSR)
810 			bits |= TIOCM_DSR;
811 		/* Not connected on some Cyclom-8Y boards? */
812 		if (msvr & CD1400_MSVR2_RI)
813 			bits |= TIOCM_RI;
814 		break;
815 
816 	case DMSET:		/* replace old values with new ones */
817 		if (cy->cy_clock == CY_CLOCK_60) {
818 			if (!ISSET(tp->t_cflag, CRTSCTS))
819 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR2,
820 				   ((bits & TIOCM_RTS) ? CD1400_MSVR2_DTR : 0));
821 			cd_write_reg(sc, cy->cy_chip, CD1400_MSVR1,
822 			    ((bits & TIOCM_DTR) ? CD1400_MSVR1_RTS : 0));
823 		} else {
824 			if (!ISSET(tp->t_cflag, CRTSCTS))
825 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR1,
826 				   ((bits & TIOCM_RTS) ? CD1400_MSVR1_RTS : 0));
827 			cd_write_reg(sc, cy->cy_chip, CD1400_MSVR2,
828 			    ((bits & TIOCM_DTR) ? CD1400_MSVR2_DTR : 0));
829 		}
830 		break;
831 
832 	case DMBIS:		/* set bits */
833 		if (cy->cy_clock == CY_CLOCK_60) {
834 			if (!ISSET(tp->t_cflag, CRTSCTS) &&
835 			    (bits & TIOCM_RTS) != 0)
836 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR2,
837 				    CD1400_MSVR2_DTR);
838 			if (bits & TIOCM_DTR)
839 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR1,
840 				    CD1400_MSVR1_RTS);
841 		} else {
842 			if (!ISSET(tp->t_cflag, CRTSCTS) &&
843 			    (bits & TIOCM_RTS) != 0)
844 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR1,
845 				    CD1400_MSVR1_RTS);
846 			if (bits & TIOCM_DTR)
847 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR2,
848 				    CD1400_MSVR2_DTR);
849 		}
850 		break;
851 
852 	case DMBIC:		/* clear bits */
853 		if (cy->cy_clock == CY_CLOCK_60) {
854 			if (!ISSET(tp->t_cflag, CRTSCTS) && (bits & TIOCM_RTS))
855 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR2, 0);
856 			if (bits & TIOCM_DTR)
857 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR1, 0);
858 		} else {
859 			if (!ISSET(tp->t_cflag, CRTSCTS) && (bits & TIOCM_RTS))
860 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR1, 0);
861 			if (bits & TIOCM_DTR)
862 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR2, 0);
863 		}
864 		break;
865 	}
866 	splx(s);
867 	return ((howto == DMGET) ? bits : 0);
868 }
869 
870 /*
871  * Upper-level handler loop (called from timer interrupt?)
872  * This routine is common for multiple cards
873  */
874 void
875 cy_poll(void *arg)
876 {
877 	int card, port;
878 	struct cy_softc *sc;
879 	struct cy_port *cy;
880 	struct tty *tp;
881 	static int counter = 0;
882 #ifdef CY_DEBUG1
883 	int did_something;
884 #endif
885 	int s = spltty();
886 
887 	if (cy_events == 0 && ++counter < 200) {
888 		splx(s);
889 		goto out;
890 	}
891 	cy_events = 0;
892 	splx(s);
893 
894 	for (card = 0; card < cy_cd.cd_ndevs; card++) {
895 		sc = device_lookup(&cy_cd, card);
896 		if (sc == NULL)
897 			continue;
898 
899 #ifdef CY_DEBUG1
900 		sc->sc_poll_count1++;
901 		did_something = 0;
902 #endif
903 
904 		for (port = 0; port < sc->sc_nchannels; port++) {
905 			cy = &sc->sc_ports[port];
906 			if ((tp = cy->cy_tty) == NULL || cy->cy_ibuf == NULL ||
907 			    (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0))
908 				continue;
909 
910 			/*
911 		         * handle received data
912 		         */
913 			while (cy->cy_ibuf_rd_ptr != cy->cy_ibuf_wr_ptr) {
914 				u_char line_stat;
915 				int chr;
916 
917 				line_stat = cy->cy_ibuf_rd_ptr[0];
918 				chr = cy->cy_ibuf_rd_ptr[1];
919 
920 				if (line_stat &
921 				    (CD1400_RDSR_BREAK | CD1400_RDSR_FE))
922 					chr |= TTY_FE;
923 				if (line_stat & CD1400_RDSR_PE)
924 					chr |= TTY_PE;
925 
926 				/*
927 				 * on an overrun error the data is treated as
928 				 * good just as it should be.
929 				 */
930 
931 #ifdef CY_DEBUG
932 				printf("%s: port %d ttyinput 0x%x\n",
933 				    sc->sc_dev.dv_xname, port, chr);
934 #endif
935 
936 				(*tp->t_linesw->l_rint) (chr, tp);
937 
938 				s = spltty();	/* really necessary? */
939 				if ((cy->cy_ibuf_rd_ptr += 2) ==
940 				    cy->cy_ibuf_end)
941 					cy->cy_ibuf_rd_ptr = cy->cy_ibuf;
942 				splx(s);
943 
944 #ifdef CY_DEBUG1
945 				did_something = 1;
946 #endif
947 			}
948 
949 			/*
950 			 * If we don't have any received data in ibuf and
951 			 * CRTSCTS is on and RTS is turned off, it is time to
952 			 * turn RTS back on
953 			 */
954 			if (ISSET(tp->t_cflag, CRTSCTS)) {
955 				/*
956 				 * we can't use cy_modem_control() here as it
957 				 * doesn't change RTS if RTSCTS is on
958 				 */
959 				cd_write_reg(sc, cy->cy_chip, CD1400_CAR,
960 				    port & CD1400_CAR_CHAN);
961 
962 				if (cy->cy_clock == CY_CLOCK_60) {
963 				  if ((cd_read_reg(sc, cy->cy_chip,
964 				    CD1400_MSVR2) & CD1400_MSVR2_DTR) == 0) {
965 					cd_write_reg(sc, cy->cy_chip,
966 					CD1400_MSVR2,CD1400_MSVR2_DTR);
967 #ifdef CY_DEBUG1
968 					did_something = 1;
969 #endif
970 				  }
971 				} else {
972 				  if ((cd_read_reg(sc, cy->cy_chip,
973 				    CD1400_MSVR1) & CD1400_MSVR1_RTS) == 0) {
974 					cd_write_reg(sc, cy->cy_chip,
975 					CD1400_MSVR1,CD1400_MSVR1_RTS);
976 #ifdef CY_DEBUG1
977 					did_something = 1;
978 #endif
979 				  }
980 				}
981 			}
982 
983 			/*
984 		         * handle carrier changes
985 		         */
986 			s = spltty();
987 			if (ISSET(cy->cy_flags, CY_F_CARRIER_CHANGED)) {
988 				int             carrier;
989 
990 				CLR(cy->cy_flags, CY_F_CARRIER_CHANGED);
991 				splx(s);
992 
993 				carrier = ((cy->cy_carrier_stat &
994 				    CD1400_MSVR2_CD) != 0);
995 
996 #ifdef CY_DEBUG
997 				printf("cy_poll: carrier change "
998 				    "(card %d, port %d, carrier %d)\n",
999 				    card, port, carrier);
1000 #endif
1001 				if (CY_DIALOUT(tp->t_dev) == 0 &&
1002 				    !(*tp->t_linesw->l_modem)(tp, carrier))
1003 					cy_modem_control(sc, cy,
1004 					    TIOCM_DTR, DMBIC);
1005 
1006 #ifdef CY_DEBUG1
1007 				did_something = 1;
1008 #endif
1009 			} else
1010 				splx(s);
1011 
1012 			s = spltty();
1013 			if (ISSET(cy->cy_flags, CY_F_START)) {
1014 				CLR(cy->cy_flags, CY_F_START);
1015 				splx(s);
1016 
1017 				(*tp->t_linesw->l_start) (tp);
1018 
1019 #ifdef CY_DEBUG1
1020 				did_something = 1;
1021 #endif
1022 			} else
1023 				splx(s);
1024 
1025 			/* could move this to even upper level... */
1026 			if (cy->cy_fifo_overruns) {
1027 				cy->cy_fifo_overruns = 0;
1028 				/*
1029 				 * doesn't report overrun count, but
1030 				 * shouldn't really matter
1031 				 */
1032 				log(LOG_WARNING, "%s: port %d fifo overrun\n",
1033 				    sc->sc_dev.dv_xname, port);
1034 			}
1035 			if (cy->cy_ibuf_overruns) {
1036 				cy->cy_ibuf_overruns = 0;
1037 				log(LOG_WARNING, "%s: port %d ibuf overrun\n",
1038 				    sc->sc_dev.dv_xname, port);
1039 			}
1040 		}		/* for(port...) */
1041 #ifdef CY_DEBUG1
1042 		if (did_something && counter >= 200)
1043 			sc->sc_poll_count2++;
1044 #endif
1045 	} /* for(card...) */
1046 
1047 	counter = 0;
1048 
1049 out:
1050 	callout_reset(&cy_poll_callout, 1, cy_poll, NULL);
1051 }
1052 
1053 /*
1054  * hardware interrupt routine
1055  */
1056 int
1057 cy_intr(void *arg)
1058 {
1059 	struct cy_softc *sc = arg;
1060 	struct cy_port *cy;
1061 	int cy_chip, stat;
1062 	int int_serviced = 0;
1063 
1064 	/*
1065 	 * Check interrupt status of each CD1400 chip on this card
1066 	 * (multiple cards cannot share the same interrupt)
1067 	 */
1068 	for (cy_chip = 0; cy_chip < sc->sc_nchips; cy_chip++) {
1069 
1070 		stat = cd_read_reg(sc, cy_chip, CD1400_SVRR);
1071 		if (stat == 0)
1072 			continue;
1073 
1074 		if (ISSET(stat, CD1400_SVRR_RXRDY)) {
1075 			u_char save_car, save_rir, serv_type;
1076 			u_char line_stat, recv_data, n_chars;
1077 			u_char *buf_p;
1078 
1079 			save_rir = cd_read_reg(sc, cy_chip, CD1400_RIR);
1080 			save_car = cd_read_reg(sc, cy_chip, CD1400_CAR);
1081 			/* enter rx service */
1082 			cd_write_reg(sc, cy_chip, CD1400_CAR, save_rir);
1083 
1084 			serv_type = cd_read_reg(sc, cy_chip, CD1400_RIVR);
1085 			cy = &sc->sc_ports[serv_type >> 3];
1086 
1087 #ifdef CY_DEBUG1
1088 			cy->cy_rx_int_count++;
1089 #endif
1090 
1091 			buf_p = cy->cy_ibuf_wr_ptr;
1092 
1093 			if (ISSET(serv_type, CD1400_RIVR_EXCEPTION)) {
1094 				line_stat = cd_read_reg(sc, cy->cy_chip,
1095 				    CD1400_RDSR);
1096 				recv_data = cd_read_reg(sc, cy->cy_chip,
1097 				    CD1400_RDSR);
1098 
1099 				if (cy->cy_tty == NULL ||
1100 				    !ISSET(cy->cy_tty->t_state, TS_ISOPEN))
1101 					goto end_rx_serv;
1102 
1103 #ifdef CY_DEBUG
1104 				printf("%s port %d recv exception, line_stat 0x%x, char 0x%x\n",
1105 				sc->sc_dev.dv_xname, cy->cy_port_num, line_stat, recv_data);
1106 #endif
1107 				if (ISSET(line_stat, CD1400_RDSR_OE))
1108 					cy->cy_fifo_overruns++;
1109 
1110 				*buf_p++ = line_stat;
1111 				*buf_p++ = recv_data;
1112 				if (buf_p == cy->cy_ibuf_end)
1113 					buf_p = cy->cy_ibuf;
1114 
1115 				if (buf_p == cy->cy_ibuf_rd_ptr) {
1116 					if (buf_p == cy->cy_ibuf)
1117 						buf_p = cy->cy_ibuf_end;
1118 					buf_p -= 2;
1119 					cy->cy_ibuf_overruns++;
1120 				}
1121 				cy_events = 1;
1122 			} else {/* no exception, received data OK */
1123 				n_chars = cd_read_reg(sc, cy->cy_chip,
1124 				    CD1400_RDCR);
1125 
1126 				/* If no tty or not open, discard data */
1127 				if (cy->cy_tty == NULL ||
1128 				    !ISSET(cy->cy_tty->t_state, TS_ISOPEN)) {
1129 					while (n_chars--)
1130 						cd_read_reg(sc, cy->cy_chip,
1131 							    CD1400_RDSR);
1132 					goto end_rx_serv;
1133 				}
1134 
1135 #ifdef CY_DEBUG
1136 				printf("%s port %d receive ok %d chars\n",
1137 				    sc->sc_dev.dv_xname, cy->cy_port_num, n_chars);
1138 #endif
1139 				while (n_chars--) {
1140 					*buf_p++ = 0;	/* status: OK */
1141 					/* data byte */
1142 					*buf_p++ = cd_read_reg(sc,
1143 					    cy->cy_chip, CD1400_RDSR);
1144 					if (buf_p == cy->cy_ibuf_end)
1145 						buf_p = cy->cy_ibuf;
1146 					if (buf_p == cy->cy_ibuf_rd_ptr) {
1147 						if (buf_p == cy->cy_ibuf)
1148 							buf_p = cy->cy_ibuf_end;
1149 						buf_p -= 2;
1150 						cy->cy_ibuf_overruns++;
1151 						break;
1152 					}
1153 				}
1154 				cy_events = 1;
1155 			}
1156 
1157 			cy->cy_ibuf_wr_ptr = buf_p;
1158 
1159 			/* RTS handshaking for incoming data */
1160 			if (ISSET(cy->cy_tty->t_cflag, CRTSCTS)) {
1161 				int bf, msvr;
1162 
1163 				bf = buf_p - cy->cy_ibuf_rd_ptr;
1164 				if (bf < 0)
1165 					bf += CY_IBUF_SIZE;
1166 
1167 				if (bf > (CY_IBUF_SIZE / 2)) {
1168 					/* turn RTS off */
1169 					if (cy->cy_clock == CY_CLOCK_60)
1170 						msvr = CD1400_MSVR2;
1171 					else
1172 						msvr = CD1400_MSVR1;
1173 					cd_write_reg(sc, cy->cy_chip, msvr, 0);
1174 				}
1175 			}
1176 
1177 	end_rx_serv:
1178 			/* terminate service context */
1179 			cd_write_reg(sc, cy->cy_chip, CD1400_RIR,
1180 				     save_rir & 0x3f);
1181 			cd_write_reg(sc, cy->cy_chip, CD1400_CAR, save_car);
1182 			int_serviced = 1;
1183 		} /* if (rx_service...) */
1184 		if (ISSET(stat, CD1400_SVRR_MDMCH)) {
1185 			u_char save_car, save_mir, serv_type, modem_stat;
1186 
1187 			save_mir = cd_read_reg(sc, cy_chip, CD1400_MIR);
1188 			save_car = cd_read_reg(sc, cy_chip, CD1400_CAR);
1189 			/* enter modem service */
1190 			cd_write_reg(sc, cy_chip, CD1400_CAR, save_mir);
1191 
1192 			serv_type = cd_read_reg(sc, cy_chip, CD1400_MIVR);
1193 			cy = &sc->sc_ports[serv_type >> 3];
1194 
1195 #ifdef CY_DEBUG1
1196 			cy->cy_modem_int_count++;
1197 #endif
1198 
1199 			modem_stat = cd_read_reg(sc, cy->cy_chip, CD1400_MSVR2);
1200 
1201 #ifdef CY_DEBUG
1202 			printf("%s port %d modem line change, new stat 0x%x\n",
1203 			       sc->sc_dev.dv_xname, cy->cy_port_num, modem_stat);
1204 #endif
1205 			if (ISSET((cy->cy_carrier_stat ^ modem_stat), CD1400_MSVR2_CD)) {
1206 				SET(cy->cy_flags, CY_F_CARRIER_CHANGED);
1207 				cy_events = 1;
1208 			}
1209 			cy->cy_carrier_stat = modem_stat;
1210 
1211 			/* terminate service context */
1212 			cd_write_reg(sc, cy->cy_chip, CD1400_MIR, save_mir & 0x3f);
1213 			cd_write_reg(sc, cy->cy_chip, CD1400_CAR, save_car);
1214 			int_serviced = 1;
1215 		} /* if (modem_service...) */
1216 		if (ISSET(stat, CD1400_SVRR_TXRDY)) {
1217 			u_char          save_car, save_tir, serv_type,
1218 			                count, ch;
1219 			struct tty     *tp;
1220 
1221 			save_tir = cd_read_reg(sc, cy_chip, CD1400_TIR);
1222 			save_car = cd_read_reg(sc, cy_chip, CD1400_CAR);
1223 			/* enter tx service */
1224 			cd_write_reg(sc, cy_chip, CD1400_CAR, save_tir);
1225 
1226 			serv_type = cd_read_reg(sc, cy_chip, CD1400_TIVR);
1227 			cy = &sc->sc_ports[serv_type >> 3];
1228 
1229 #ifdef CY_DEBUG1
1230 			cy->cy_tx_int_count++;
1231 #endif
1232 #ifdef CY_DEBUG
1233 			printf("%s port %d tx service\n", sc->sc_dev.dv_xname,
1234 			    cy->cy_port_num);
1235 #endif
1236 
1237 			/* stop transmitting if no tty or CY_F_STOP set */
1238 			tp = cy->cy_tty;
1239 			if (tp == NULL || ISSET(cy->cy_flags, CY_F_STOP))
1240 				goto txdone;
1241 
1242 			count = 0;
1243 			if (ISSET(cy->cy_flags, CY_F_SEND_NUL)) {
1244 				cd_write_reg(sc, cy->cy_chip, CD1400_TDR, 0);
1245 				cd_write_reg(sc, cy->cy_chip, CD1400_TDR, 0);
1246 				count += 2;
1247 				CLR(cy->cy_flags, CY_F_SEND_NUL);
1248 			}
1249 			if (tp->t_outq.c_cc > 0) {
1250 				SET(tp->t_state, TS_BUSY);
1251 				while (tp->t_outq.c_cc > 0 &&
1252 				    count < CD1400_TX_FIFO_SIZE) {
1253 					ch = getc(&tp->t_outq);
1254 					/*
1255 					 * remember to double NUL characters
1256 					 * because embedded transmit commands
1257 					 * are enabled
1258 					 */
1259 					if (ch == 0) {
1260 						if (count >= CD1400_TX_FIFO_SIZE - 2) {
1261 							SET(cy->cy_flags, CY_F_SEND_NUL);
1262 							break;
1263 						}
1264 						cd_write_reg(sc, cy->cy_chip,
1265 						    CD1400_TDR, ch);
1266 						count++;
1267 					}
1268 					cd_write_reg(sc, cy->cy_chip,
1269 					    CD1400_TDR, ch);
1270 					count++;
1271 				}
1272 			} else {
1273 				/*
1274 				 * no data to send -- check if we should
1275 				 * start/stop a break
1276 				 */
1277 				/*
1278 				 * XXX does this cause too much delay before
1279 				 * breaks?
1280 				 */
1281 				if (ISSET(cy->cy_flags, CY_F_START_BREAK)) {
1282 					cd_write_reg(sc, cy->cy_chip,
1283 					    CD1400_TDR, 0);
1284 					cd_write_reg(sc, cy->cy_chip,
1285 					    CD1400_TDR, 0x81);
1286 					CLR(cy->cy_flags, CY_F_START_BREAK);
1287 				}
1288 				if (ISSET(cy->cy_flags, CY_F_END_BREAK)) {
1289 					cd_write_reg(sc, cy->cy_chip,
1290 					    CD1400_TDR, 0);
1291 					cd_write_reg(sc, cy->cy_chip,
1292 					    CD1400_TDR, 0x83);
1293 					CLR(cy->cy_flags, CY_F_END_BREAK);
1294 				}
1295 			}
1296 
1297 			if (tp->t_outq.c_cc == 0) {
1298 		txdone:
1299 				/*
1300 				 * No data to send or requested to stop.
1301 				 * Disable transmit interrupt
1302 				 */
1303 				cd_write_reg(sc, cy->cy_chip, CD1400_SRER,
1304 				     cd_read_reg(sc, cy->cy_chip, CD1400_SRER)
1305 				     & ~CD1400_SRER_TXRDY);
1306 				CLR(cy->cy_flags, CY_F_STOP);
1307 				CLR(tp->t_state, TS_BUSY);
1308 			}
1309 			if (tp->t_outq.c_cc <= tp->t_lowat) {
1310 				SET(cy->cy_flags, CY_F_START);
1311 				cy_events = 1;
1312 			}
1313 			/* terminate service context */
1314 			cd_write_reg(sc, cy->cy_chip, CD1400_TIR, save_tir & 0x3f);
1315 			cd_write_reg(sc, cy->cy_chip, CD1400_CAR, save_car);
1316 			int_serviced = 1;
1317 		}		/* if (tx_service...) */
1318 	}			/* for(...all CD1400s on a card) */
1319 
1320 	/* ensure an edge for next interrupt */
1321 	bus_space_write_1(sc->sc_memt, sc->sc_bsh,
1322 			CY_CLEAR_INTR << sc->sc_bustype, 0);
1323 	return int_serviced;
1324 }
1325 
1326 /*
1327  * subroutine to enable CD1400 transmitter
1328  */
1329 void
1330 cy_enable_transmitter(struct cy_softc *sc, struct cy_port *cy)
1331 {
1332 	int s = spltty();
1333 	cd_write_reg(sc, cy->cy_chip, CD1400_CAR,
1334 	    cy->cy_port_num & CD1400_CAR_CHAN);
1335 	cd_write_reg(sc, cy->cy_chip, CD1400_SRER,
1336 	    cd_read_reg(sc, cy->cy_chip, CD1400_SRER) | CD1400_SRER_TXRDY);
1337 	splx(s);
1338 }
1339 
1340 /*
1341  * Execute a CD1400 channel command
1342  */
1343 void
1344 cd1400_channel_cmd(struct cy_softc *sc, struct cy_port *cy, int cmd)
1345 {
1346 	u_int waitcnt = 5 * 8 * 1024;	/* approx 5 ms */
1347 
1348 #ifdef CY_DEBUG
1349 	printf("c1400_channel_cmd cy %p command 0x%x\n", cy, cmd);
1350 #endif
1351 
1352 	/* wait until cd1400 is ready to process a new command */
1353 	while (cd_read_reg(sc, cy->cy_chip, CD1400_CCR) != 0 && waitcnt-- > 0);
1354 
1355 	if (waitcnt == 0)
1356 		log(LOG_ERR, "%s: channel command timeout\n",
1357 		    sc->sc_dev.dv_xname);
1358 
1359 	cd_write_reg(sc, cy->cy_chip, CD1400_CCR, cmd);
1360 }
1361 
1362 /*
1363  * Compute clock option register and baud rate register values
1364  * for a given speed. Return 0 on success, -1 on failure.
1365  *
1366  * The error between requested and actual speed seems
1367  * to be well within allowed limits (less than 3%)
1368  * with every speed value between 50 and 150000 bps.
1369  */
1370 int
1371 cy_speed(speed_t speed, int *cor, int *bpr, int cy_clock)
1372 {
1373 	int c, co, br;
1374 
1375 	if (speed < 50 || speed > 150000)
1376 		return -1;
1377 
1378 	for (c = 0, co = 8; co <= 2048; co <<= 2, c++) {
1379 		br = (cy_clock + (co * speed) / 2) / (co * speed);
1380 		if (br < 0x100) {
1381 			*bpr = br;
1382 			*cor = c;
1383 			return 0;
1384 		}
1385 	}
1386 
1387 	return -1;
1388 }
1389