xref: /netbsd/sys/dev/ic/cy.c (revision 6550d01e)
1 /*	$NetBSD: cy.c,v 1.57 2009/11/23 02:13:46 rmind 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 1.57 2009/11/23 02:13:46 rmind 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/select.h>
29 #include <sys/device.h>
30 #include <sys/malloc.h>
31 #include <sys/systm.h>
32 #include <sys/callout.h>
33 #include <sys/kauth.h>
34 
35 #include <sys/bus.h>
36 
37 #include <dev/ic/cd1400reg.h>
38 #include <dev/ic/cyreg.h>
39 #include <dev/ic/cyvar.h>
40 
41 static int	cyparam(struct tty *, struct termios *);
42 static void	cystart(struct tty *);
43 static void	cy_poll(void *);
44 static int	cy_modem_control(struct cy_softc *, struct cy_port *, int, int);
45 static void	cy_enable_transmitter(struct cy_softc *, struct cy_port *);
46 static void	cd1400_channel_cmd(struct cy_softc *, struct cy_port *, int);
47 static int	cy_speed(speed_t, int *, int *, int);
48 
49 extern struct cfdriver cy_cd;
50 
51 static dev_type_open(cyopen);
52 static dev_type_close(cyclose);
53 static dev_type_read(cyread);
54 static dev_type_write(cywrite);
55 static dev_type_ioctl(cyioctl);
56 static dev_type_stop(cystop);
57 static dev_type_tty(cytty);
58 static dev_type_poll(cypoll);
59 
60 const struct cdevsw cy_cdevsw = {
61 	.d_open = cyopen,
62 	.d_close = cyclose,
63 	.d_read = cyread,
64 	.d_write = cywrite,
65 	.d_ioctl = cyioctl,
66 	.d_stop = cystop,
67 	.d_tty = cytty,
68 	.d_poll = cypoll,
69 	.d_mmap = nommap,
70 	.d_kqfilter = ttykqfilter,
71 	.d_flag = D_TTY
72 };
73 
74 static int      cy_open = 0;
75 static int      cy_events = 0;
76 
77 int	cy_attached_ttys;
78 bool	cy_callout_init;
79 callout_t cy_poll_callout;
80 
81 /*
82  * Common probe routine
83  */
84 int
85 cy_find(struct cy_softc *sc)
86 {
87 	int cy_chip, chip;
88 	u_char firmware_ver;
89 	bus_space_tag_t tag = sc->sc_memt;
90 	bus_space_handle_t bsh = sc->sc_bsh;
91 	int bustype = sc->sc_bustype;
92 
93 	/* Cyclom card hardware reset */
94 	bus_space_write_1(tag, bsh, CY16_RESET << bustype, 0);
95 	DELAY(500);		/* wait for reset to complete */
96 	bus_space_write_1(tag, bsh, CY_CLEAR_INTR << bustype, 0);
97 
98 #ifdef CY_DEBUG
99 	printf("cy: card reset done\n");
100 #endif
101 	sc->sc_nchips = 0;
102 
103 	for (cy_chip = 0, chip = 0; cy_chip < CY_MAX_CD1400s;
104 	    cy_chip++, chip += (CY_CD1400_MEMSPACING << bustype)) {
105 		int i;
106 
107 		/*
108 		 * the last 4 nchips are 'interleaved' with the first 4 on
109 		 * 32-port boards
110 		 */
111 		if (cy_chip == 4)
112 			chip -= (CY32_ADDR_FIX << bustype);
113 
114 #ifdef CY_DEBUG
115 		printf("sy: probe chip %d offset 0x%x ... ", cy_chip, chip);
116 #endif
117 
118 		/* wait until the chip is ready for command */
119 		DELAY(1000);
120 		if (bus_space_read_1(tag, bsh, chip +
121 		    ((CD1400_CCR << 1) << bustype)) != 0) {
122 #ifdef CY_DEBUG
123 			printf("not ready for command\n");
124 #endif
125 			break;
126 		}
127 		/* clear the firmware version reg. */
128 		bus_space_write_1(tag, bsh, chip +
129 		    ((CD1400_GFRCR << 1) << bustype), 0);
130 
131 		/*
132 	         * On Cyclom-16 references to non-existent chip 4
133 	         * actually access chip 0 (address line 9 not decoded).
134 	         * Here we check if the clearing of chip 4 GFRCR actually
135 	         * cleared chip 0 GFRCR. In that case we have a 16 port card.
136 	         */
137 		if (cy_chip == 4 &&
138 		    bus_space_read_1(tag, bsh, /* off for chip 0 (0) + */
139 		       ((CD1400_GFRCR << 1) << bustype)) == 0)
140 			break;
141 
142 		/* reset the chip */
143 		bus_space_write_1(tag, bsh, chip +
144 		    ((CD1400_CCR << 1) << bustype),
145 		    CD1400_CCR_CMDRESET | CD1400_CCR_FULLRESET);
146 
147 		/* wait for the chip to initialize itself */
148 		for (i = 0; i < 200; i++) {
149 			DELAY(50);
150 			firmware_ver = bus_space_read_1(tag, bsh, chip +
151 			    ((CD1400_GFRCR << 1) << bustype));
152 			if ((firmware_ver & 0xf0) == 0x40) /* found a CD1400 */
153 				break;
154 		}
155 #ifdef CY_DEBUG
156 		printf("firmware version 0x%x\n", firmware_ver);
157 #endif
158 
159 		if ((firmware_ver & 0xf0) != 0x40)
160 			break;
161 
162 		/* firmware version OK, CD1400 found */
163 		sc->sc_nchips++;
164 	}
165 
166 	if (sc->sc_nchips == 0) {
167 #ifdef CY_DEBUG
168 		printf("no CD1400s found\n");
169 #endif
170 		return 0;
171 	}
172 #ifdef CY_DEBUG
173 	printf("found %d CD1400s\n", sc->sc_nchips);
174 #endif
175 
176 	return 1;
177 }
178 
179 void
180 cy_attach(struct cy_softc *sc)
181 {
182 	int port, cy_chip, num_chips, cdu, chip;
183 	int cy_clock;
184 
185 	if (!cy_callout_init) {
186 		cy_callout_init = true;
187 		callout_init(&cy_poll_callout, 0);
188 	}
189 
190 	num_chips = sc->sc_nchips;
191 	if (num_chips == 0)
192 		return;
193 
194 	memset(sc->sc_ports, 0, sizeof(sc->sc_ports));
195 
196 	port = 0;
197 	for (cy_chip = 0, chip = 0; cy_chip < num_chips; cy_chip++,
198 	    chip += (CY_CD1400_MEMSPACING << sc->sc_bustype)) {
199 
200 		if (cy_chip == 4)
201 			chip -= (CY32_ADDR_FIX << sc->sc_bustype);
202 
203 #ifdef CY_DEBUG
204 		aprint_debug("attach CD1400 #%d offset 0x%x\n", cy_chip, chip);
205 #endif
206 		sc->sc_cd1400_offs[cy_chip] = chip;
207 
208 		/*
209 		 * configure port 0 as serial port (should already be after
210 		 * reset)
211 		 */
212 		cd_write_reg(sc, cy_chip, CD1400_GCR, 0);
213 
214 		if (cd_read_reg(sc, cy_chip, CD1400_GFRCR) <= 0x46)
215 			cy_clock = CY_CLOCK;
216 		else
217 			cy_clock = CY_CLOCK_60;
218 
219 		/* set up a receive timeout period (1ms) */
220 		cd_write_reg(sc, cy_chip, CD1400_PPR,
221 		    (cy_clock / CD1400_PPR_PRESCALER / 1000) + 1);
222 
223 		for (cdu = 0; cdu < CD1400_NO_OF_CHANNELS; cdu++) {
224 			sc->sc_ports[port].cy_softc = sc;
225 			sc->sc_ports[port].cy_port_num = port;
226 			sc->sc_ports[port].cy_chip = cy_chip;
227 			sc->sc_ports[port].cy_clock = cy_clock;
228 
229 			/* should we initialize anything else here? */
230 			port++;
231 		} /* for(each port on one CD1400...) */
232 
233 	} /* for(each CD1400 on a card... ) */
234 
235 	sc->sc_nchannels = port;
236 
237 	aprint_normal_dev(sc->sc_dev, "%d channels (ttyCY%03d..ttyCY%03d)\n",
238 	    sc->sc_nchannels, cy_attached_ttys,
239 	    cy_attached_ttys + (sc->sc_nchannels - 1));
240 
241 	cy_attached_ttys += sc->sc_nchannels;
242 
243 	/* ensure an edge for the next interrupt */
244 	bus_space_write_1(sc->sc_memt, sc->sc_bsh,
245 	    CY_CLEAR_INTR << sc->sc_bustype, 0);
246 }
247 
248 #define	CYDIALOUT_MASK		0x80000
249 #define	CY_DIALOUT(dev)		(minor(dev) & CYDIALOUT_MASK)
250 
251 #define	CY_PORT(dev)		cy_getport((dev))
252 #define	CY_BOARD(cy)		((cy)->cy_softc)
253 
254 static struct cy_port *
255 cy_getport(dev_t dev)
256 {
257 	int i, j, k, u = minor(dev) & ~CYDIALOUT_MASK;
258 	struct cy_softc *sc;
259 
260 	for (i = 0, j = 0; i < cy_cd.cd_ndevs; i++) {
261 		k = j;
262 		sc = device_lookup_private(&cy_cd, i);
263 		if (sc == NULL)
264 			continue;
265 		if (sc->sc_nchannels == 0)
266 			continue;
267 		j += sc->sc_nchannels;
268 		if (j > u)
269 			return (&sc->sc_ports[u - k]);
270 	}
271 
272 	return (NULL);
273 }
274 
275 /*
276  * open routine. returns zero if successful, else error code
277  */
278 int
279 cyopen(dev_t dev, int flag, int mode, struct lwp *l)
280 {
281 	struct cy_softc *sc;
282 	struct cy_port *cy;
283 	struct tty *tp;
284 	int s, error;
285 
286 	cy = CY_PORT(dev);
287 	if (cy == NULL)
288 		return (ENXIO);
289 	sc = CY_BOARD(cy);
290 
291 	s = spltty();
292 	if (cy->cy_tty == NULL) {
293 		if ((cy->cy_tty = ttymalloc()) == NULL) {
294 			splx(s);
295 			aprint_error_dev(sc->sc_dev,
296 			    "port %d: can't allocate tty\n",
297 			    cy->cy_port_num);
298 			return (ENOMEM);
299 		}
300 		tty_attach(cy->cy_tty);
301 	}
302 	splx(s);
303 
304 	tp = cy->cy_tty;
305 	tp->t_oproc = cystart;
306 	tp->t_param = cyparam;
307 	tp->t_dev = dev;
308 
309 	if (kauth_authorize_device_tty(l->l_cred, KAUTH_DEVICE_TTY_OPEN, tp))
310 		return (EBUSY);
311 
312 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
313 		ttychars(tp);
314 		tp->t_iflag = TTYDEF_IFLAG;
315 		tp->t_oflag = TTYDEF_OFLAG;
316 		tp->t_cflag = TTYDEF_CFLAG;
317 		if (ISSET(cy->cy_openflags, TIOCFLAG_CLOCAL))
318 			SET(tp->t_cflag, CLOCAL);
319 		if (ISSET(cy->cy_openflags, TIOCFLAG_CRTSCTS))
320 			SET(tp->t_cflag, CRTSCTS);
321 		if (ISSET(cy->cy_openflags, TIOCFLAG_MDMBUF))
322 			SET(tp->t_cflag, MDMBUF);
323 		tp->t_lflag = TTYDEF_LFLAG;
324 		tp->t_ispeed = tp->t_ospeed = TTYDEF_SPEED;
325 
326 		s = spltty();
327 
328 		/*
329 		 * Allocate input ring buffer if we don't already have one
330 		 */
331 		if (cy->cy_ibuf == NULL) {
332 			cy->cy_ibuf = malloc(CY_IBUF_SIZE, M_DEVBUF, M_NOWAIT);
333 			if (cy->cy_ibuf == NULL) {
334 				aprint_error_dev(sc->sc_dev,
335 				    "port %d: can't allocate input buffer\n",
336 				    cy->cy_port_num);
337 				splx(s);
338 				return ENOMEM;
339 			}
340 			cy->cy_ibuf_end = cy->cy_ibuf + CY_IBUF_SIZE;
341 		}
342 		/* mark the ring buffer as empty */
343 		cy->cy_ibuf_rd_ptr = cy->cy_ibuf_wr_ptr = cy->cy_ibuf;
344 
345 		/* select CD1400 channel */
346 		cd_write_reg(sc, cy->cy_chip, CD1400_CAR,
347 		    cy->cy_port_num & CD1400_CAR_CHAN);
348 		/* reset the channel */
349 		cd1400_channel_cmd(sc, cy, CD1400_CCR_CMDRESET);
350 		/* encode unit (port) number in LIVR */
351 		/* there is just enough space for 5 bits (32 ports) */
352 		cd_write_reg(sc, cy->cy_chip, CD1400_LIVR,
353 		    cy->cy_port_num << 3);
354 
355 		cy->cy_channel_control = 0;
356 
357 		/* hmm... need spltty() here? */
358 		if (cy_open == 0) {
359 			cy_open = 1;
360 			callout_reset(&cy_poll_callout, 1, cy_poll, NULL);
361 		}
362 		/* this sets parameters and raises DTR */
363 		cyparam(tp, &tp->t_termios);
364 
365 		ttsetwater(tp);
366 
367 		/* raise RTS too */
368 		cy_modem_control(sc, cy, TIOCM_RTS, DMBIS);
369 
370 		cy->cy_carrier_stat =
371 			cd_read_reg(sc, cy->cy_chip, CD1400_MSVR2);
372 
373 		/* enable receiver and modem change interrupts */
374 		cd_write_reg(sc, cy->cy_chip, CD1400_SRER,
375 		    CD1400_SRER_MDMCH | CD1400_SRER_RXDATA);
376 
377 		if (CY_DIALOUT(dev) ||
378 		    ISSET(cy->cy_openflags, TIOCFLAG_SOFTCAR) ||
379 		    ISSET(tp->t_cflag, MDMBUF) ||
380 		    ISSET(cy->cy_carrier_stat, CD1400_MSVR2_CD))
381 			SET(tp->t_state, TS_CARR_ON);
382 		else
383 			CLR(tp->t_state, TS_CARR_ON);
384 		splx(s);
385 	}
386 
387 	/* wait for carrier if necessary */
388 	if (!ISSET(flag, O_NONBLOCK)) {
389 		mutex_spin_enter(&tty_lock);
390 		while (!ISSET(tp->t_cflag, CLOCAL) &&
391 		    !ISSET(tp->t_state, TS_CARR_ON)) {
392 			tp->t_wopen++;
393 			error = ttysleep(tp, &tp->t_rawcv, true, 0);
394 			tp->t_wopen--;
395 			if (error != 0) {
396 				mutex_spin_exit(&tty_lock);
397 				return error;
398 			}
399 		}
400 		mutex_spin_exit(&tty_lock);
401 	}
402 
403 	return (*tp->t_linesw->l_open) (dev, tp);
404 }
405 
406 /*
407  * close routine. returns zero if successful, else error code
408  */
409 int
410 cyclose(dev_t dev, int flag, int mode, struct lwp *l)
411 {
412 	struct cy_softc *sc;
413 	struct cy_port *cy;
414 	struct tty *tp;
415 	int s;
416 
417 	cy = CY_PORT(dev);
418 	sc = CY_BOARD(cy);
419 	tp = cy->cy_tty;
420 
421 	(*tp->t_linesw->l_close) (tp, flag);
422 	s = spltty();
423 
424 	if (ISSET(tp->t_cflag, HUPCL) &&
425 	    !ISSET(cy->cy_openflags, TIOCFLAG_SOFTCAR)) {
426 		/*
427 		 * drop DTR and RTS (should we wait for output buffer to
428 		 * become empty first?)
429 		 */
430 		cy_modem_control(sc, cy, 0, DMSET);
431 	}
432 	/*
433 	 * XXX should we disable modem change and
434 	 * receive interrupts here or somewhere ?
435 	 */
436 	CLR(tp->t_state, TS_BUSY | TS_FLUSH);
437 
438 	splx(s);
439 	ttyclose(tp);
440 
441 	return 0;
442 }
443 
444 /*
445  * Read routine
446  */
447 int
448 cyread(dev_t dev, struct uio *uio, int flag)
449 {
450 	struct cy_port *cy;
451 	struct tty *tp;
452 
453 	cy = CY_PORT(dev);
454 	tp = cy->cy_tty;
455 
456 	return ((*tp->t_linesw->l_read)(tp, uio, flag));
457 }
458 
459 /*
460  * Write routine
461  */
462 int
463 cywrite(dev_t dev, struct uio *uio, int flag)
464 {
465 	struct cy_port *cy;
466 	struct tty *tp;
467 
468 	cy = CY_PORT(dev);
469 	tp = cy->cy_tty;
470 
471 	return ((*tp->t_linesw->l_write)(tp, uio, flag));
472 }
473 
474 /*
475  * Poll routine
476  */
477 int
478 cypoll(dev_t dev, int events, struct lwp *l)
479 {
480 	struct cy_port *cy;
481 	struct tty *tp;
482 
483 	cy = CY_PORT(dev);
484 	tp = cy->cy_tty;
485 
486 	return ((*tp->t_linesw->l_poll)(tp, events, l));
487 }
488 
489 /*
490  * return tty pointer
491  */
492 struct tty *
493 cytty(dev_t dev)
494 {
495 	struct cy_port *cy;
496 
497 	cy = CY_PORT(dev);
498 
499 	return (cy->cy_tty);
500 }
501 
502 /*
503  * ioctl routine
504  */
505 int
506 cyioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
507 {
508 	struct cy_softc *sc;
509 	struct cy_port *cy;
510 	struct tty *tp;
511 	int error;
512 
513 	cy = CY_PORT(dev);
514 	sc = CY_BOARD(cy);
515 	tp = cy->cy_tty;
516 
517 	error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, l);
518 	if (error != EPASSTHROUGH)
519 		return error;
520 
521 	error = ttioctl(tp, cmd, data, flag, l);
522 	if (error != EPASSTHROUGH)
523 		return error;
524 
525 	/* XXX should not allow dropping DTR when dialin? */
526 
527 	switch (cmd) {
528 	case TIOCSBRK:		/* start break */
529 		SET(cy->cy_flags, CY_F_START_BREAK);
530 		cy_enable_transmitter(sc, cy);
531 		break;
532 
533 	case TIOCCBRK:		/* stop break */
534 		SET(cy->cy_flags, CY_F_END_BREAK);
535 		cy_enable_transmitter(sc, cy);
536 		break;
537 
538 	case TIOCSDTR:		/* DTR on */
539 		cy_modem_control(sc, cy, TIOCM_DTR, DMBIS);
540 		break;
541 
542 	case TIOCCDTR:		/* DTR off */
543 		cy_modem_control(sc, cy, TIOCM_DTR, DMBIC);
544 		break;
545 
546 	case TIOCMSET:		/* set new modem control line values */
547 		cy_modem_control(sc, cy, *((int *) data), DMSET);
548 		break;
549 
550 	case TIOCMBIS:		/* turn modem control bits on */
551 		cy_modem_control(sc, cy, *((int *) data), DMBIS);
552 		break;
553 
554 	case TIOCMBIC:		/* turn modem control bits off */
555 		cy_modem_control(sc, cy, *((int *) data), DMBIC);
556 		break;
557 
558 	case TIOCMGET:		/* get modem control/status line state */
559 		*((int *) data) = cy_modem_control(sc, cy, 0, DMGET);
560 		break;
561 
562 	case TIOCGFLAGS:
563 		*((int *) data) = cy->cy_openflags |
564 			(CY_DIALOUT(dev) ? TIOCFLAG_SOFTCAR : 0);
565 		break;
566 
567 	case TIOCSFLAGS:
568 		error = kauth_authorize_device_tty(l->l_cred,
569 		    KAUTH_DEVICE_TTY_PRIVSET, tp);
570 		if (error != 0)
571 			return EPERM;
572 
573 		cy->cy_openflags = *((int *) data) &
574 		    (TIOCFLAG_SOFTCAR | TIOCFLAG_CLOCAL |
575 		     TIOCFLAG_CRTSCTS | TIOCFLAG_MDMBUF);
576 		break;
577 
578 	default:
579 		return EPASSTHROUGH;
580 	}
581 
582 	return 0;
583 }
584 
585 /*
586  * start output
587  */
588 void
589 cystart(struct tty *tp)
590 {
591 	struct cy_softc *sc;
592 	struct cy_port *cy;
593 	int s;
594 
595 	cy = CY_PORT(tp->t_dev);
596 	sc = cy->cy_softc;
597 
598 	s = spltty();
599 
600 #ifdef CY_DEBUG1
601 	cy->cy_start_count++;
602 #endif
603 
604 	if (!ISSET(tp->t_state, TS_TTSTOP | TS_TIMEOUT | TS_BUSY)) {
605 		if (!ttypull(tp))
606 			goto out;
607 		SET(tp->t_state, TS_BUSY);
608 		cy_enable_transmitter(sc, cy);
609 	}
610 out:
611 
612 	splx(s);
613 }
614 
615 /*
616  * stop output
617  */
618 void
619 cystop(struct tty *tp, int flag)
620 {
621 	struct cy_port *cy;
622 	int s;
623 
624 	cy = CY_PORT(tp->t_dev);
625 
626 	s = spltty();
627 	if (ISSET(tp->t_state, TS_BUSY)) {
628 		if (!ISSET(tp->t_state, TS_TTSTOP))
629 			SET(tp->t_state, TS_FLUSH);
630 
631 		/*
632 		 * the transmit interrupt routine will disable transmit when it
633 		 * notices that CY_F_STOP has been set.
634 		 */
635 		SET(cy->cy_flags, CY_F_STOP);
636 	}
637 	splx(s);
638 }
639 
640 /*
641  * parameter setting routine.
642  * returns 0 if successful, else returns error code
643  */
644 int
645 cyparam(struct tty *tp, struct termios *t)
646 {
647 	struct cy_softc *sc;
648 	struct cy_port *cy;
649 	int ibpr = 0, obpr = 0, i_clk_opt = 0, o_clk_opt = 0;	/* XXX: GCC */
650 	int s, opt;
651 
652 	cy = CY_PORT(tp->t_dev);
653 	sc = CY_BOARD(cy);
654 
655 	if (t->c_ospeed != 0 && cy_speed(t->c_ospeed, &o_clk_opt, &obpr, cy->cy_clock) < 0)
656 		return EINVAL;
657 
658 	if (t->c_ispeed != 0 && cy_speed(t->c_ispeed, &i_clk_opt, &ibpr, cy->cy_clock) < 0)
659 		return EINVAL;
660 
661 	s = spltty();
662 
663 	/* hang up the line is ospeed is zero, else turn DTR on */
664 	cy_modem_control(sc, cy, TIOCM_DTR, (t->c_ospeed == 0 ? DMBIC : DMBIS));
665 
666 	/* channel was selected by the above call to cy_modem_control() */
667 #if 0
668 	cd_write_reg(sc, cy->cy_chip, CD1400_CAR, port & CD1400_CAR_CHAN);
669 #endif
670 
671 	/* set transmit speed */
672 	if (t->c_ospeed != 0) {
673 		cd_write_reg(sc, cy->cy_chip, CD1400_TCOR, o_clk_opt);
674 		cd_write_reg(sc, cy->cy_chip, CD1400_TBPR, obpr);
675 	}
676 	/* set receive speed */
677 	if (t->c_ispeed != 0) {
678 		cd_write_reg(sc, cy->cy_chip, CD1400_RCOR, i_clk_opt);
679 		cd_write_reg(sc, cy->cy_chip, CD1400_RBPR, ibpr);
680 	}
681 	opt = CD1400_CCR_CMDCHANCTL | CD1400_CCR_XMTEN
682 		| (ISSET(t->c_cflag, CREAD) ? CD1400_CCR_RCVEN : CD1400_CCR_RCVDIS);
683 
684 	if (opt != cy->cy_channel_control) {
685 		cy->cy_channel_control = opt;
686 		cd1400_channel_cmd(sc, cy, opt);
687 	}
688 	/* compute COR1 contents */
689 	opt = 0;
690 	if (ISSET(t->c_cflag, PARENB)) {
691 		if (ISSET(t->c_cflag, PARODD))
692 			opt |= CD1400_COR1_PARODD;
693 		opt |= CD1400_COR1_PARNORMAL;
694 	}
695 	if (!ISSET(t->c_iflag, INPCK))
696 		opt |= CD1400_COR1_NOINPCK;	/* no parity checking */
697 
698 	if (ISSET(t->c_cflag, CSTOPB))
699 		opt |= CD1400_COR1_STOP2;
700 
701 	switch (t->c_cflag & CSIZE) {
702 	case CS5:
703 		opt |= CD1400_COR1_CS5;
704 		break;
705 
706 	case CS6:
707 		opt |= CD1400_COR1_CS6;
708 		break;
709 
710 	case CS7:
711 		opt |= CD1400_COR1_CS7;
712 		break;
713 
714 	default:
715 		opt |= CD1400_COR1_CS8;
716 		break;
717 	}
718 
719 	cd_write_reg(sc, cy->cy_chip, CD1400_COR1, opt);
720 
721 #ifdef CY_DEBUG
722 	printf("cor1 = 0x%x...", opt);
723 #endif
724 
725 	/*
726 	 * use the CD1400 automatic CTS flow control if CRTSCTS is set
727 	 *
728 	 * CD1400_COR2_ETC is used because breaks are generated with
729 	 * embedded transmit commands
730 	 */
731 	cd_write_reg(sc, cy->cy_chip, CD1400_COR2,
732 		     CD1400_COR2_ETC |
733 		 (ISSET(t->c_cflag, CRTSCTS) ? CD1400_COR2_CCTS_OFLOW : 0));
734 
735 	cd_write_reg(sc, cy->cy_chip, CD1400_COR3, CY_RX_FIFO_THRESHOLD);
736 
737 	cd1400_channel_cmd(sc, cy, CD1400_CCR_CMDCORCHG |
738 	    CD1400_CCR_COR1 | CD1400_CCR_COR2 | CD1400_CCR_COR3);
739 
740 	cd_write_reg(sc, cy->cy_chip, CD1400_COR4, CD1400_COR4_PFO_EXCEPTION);
741 	cd_write_reg(sc, cy->cy_chip, CD1400_COR5, 0);
742 
743 	/*
744          * set modem change option registers to generate interrupts
745          * on carrier detect changes.
746          *
747          * if hardware RTS handshaking is used
748          * also set the handshaking threshold.
749          */
750 	if (cy->cy_clock == CY_CLOCK_60) {
751 	   cd_write_reg(sc, cy->cy_chip, CD1400_MCOR1, CD1400_MCOR1_CDzd |
752     	      (ISSET(t->c_cflag, CRTSCTS) ? CY_RX_DTR_THRESHOLD : 0));
753 	} else {
754 	   cd_write_reg(sc, cy->cy_chip, CD1400_MCOR1, CD1400_MCOR1_CDzd);
755 	}
756 
757 	cd_write_reg(sc, cy->cy_chip, CD1400_MCOR2, CD1400_MCOR2_CDod);
758 
759 	/*
760          * set receive timeout to approx. 2ms
761          * could use more complex logic here...
762          * (but is it actually needed or even useful?)
763          */
764 	cd_write_reg(sc, cy->cy_chip, CD1400_RTPR, 2);
765 
766 	/*
767          * should do anything else here?
768          * XXX check MDMBUF handshaking like in com.c?
769          */
770 
771 	splx(s);
772 	return 0;
773 }
774 
775 /*
776  * set/get modem line status
777  *
778  * bits can be: TIOCM_DTR, TIOCM_RTS, TIOCM_CTS, TIOCM_CD, TIOCM_RI, TIOCM_DSR
779  */
780 int
781 cy_modem_control(struct cy_softc *sc, struct cy_port *cy, int bits, int howto)
782 {
783 	struct tty *tp = cy->cy_tty;
784 	int s, msvr;
785 
786 	s = spltty();
787 
788 	/* select channel */
789 	cd_write_reg(sc, cy->cy_chip, CD1400_CAR,
790 	    cy->cy_port_num & CD1400_CAR_CHAN);
791 
792 	/* Does not manipulate RTS if it is used for flow control. */
793 	switch (howto) {
794 	case DMGET:
795 		bits = 0;
796 		if (cy->cy_channel_control & CD1400_CCR_RCVEN)
797 			bits |= TIOCM_LE;
798 		msvr = cd_read_reg(sc, cy->cy_chip, CD1400_MSVR2);
799 		if (cy->cy_clock == CY_CLOCK_60) {
800 			if (cd_read_reg(sc, cy->cy_chip, CD1400_MSVR1) &
801 		    		CD1400_MSVR1_RTS)
802 				bits |= TIOCM_DTR;
803 			if (msvr & CD1400_MSVR2_DTR)
804 				bits |= TIOCM_RTS;
805 		} else {
806 			if (cd_read_reg(sc, cy->cy_chip, CD1400_MSVR1) &
807 			    CD1400_MSVR1_RTS)
808 				bits |= TIOCM_RTS;
809 			if (msvr & CD1400_MSVR2_DTR)
810 				bits |= TIOCM_DTR;
811 		}
812 		if (msvr & CD1400_MSVR2_CTS)
813 			bits |= TIOCM_CTS;
814 		if (msvr & CD1400_MSVR2_CD)
815 			bits |= TIOCM_CD;
816 		/* Not connected on some Cyclom-Y boards? */
817 		if (msvr & CD1400_MSVR2_DSR)
818 			bits |= TIOCM_DSR;
819 		/* Not connected on some Cyclom-8Y boards? */
820 		if (msvr & CD1400_MSVR2_RI)
821 			bits |= TIOCM_RI;
822 		break;
823 
824 	case DMSET:		/* replace old values with new ones */
825 		if (cy->cy_clock == CY_CLOCK_60) {
826 			if (!ISSET(tp->t_cflag, CRTSCTS))
827 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR2,
828 				   ((bits & TIOCM_RTS) ? CD1400_MSVR2_DTR : 0));
829 			cd_write_reg(sc, cy->cy_chip, CD1400_MSVR1,
830 			    ((bits & TIOCM_DTR) ? CD1400_MSVR1_RTS : 0));
831 		} else {
832 			if (!ISSET(tp->t_cflag, CRTSCTS))
833 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR1,
834 				   ((bits & TIOCM_RTS) ? CD1400_MSVR1_RTS : 0));
835 			cd_write_reg(sc, cy->cy_chip, CD1400_MSVR2,
836 			    ((bits & TIOCM_DTR) ? CD1400_MSVR2_DTR : 0));
837 		}
838 		break;
839 
840 	case DMBIS:		/* set bits */
841 		if (cy->cy_clock == CY_CLOCK_60) {
842 			if (!ISSET(tp->t_cflag, CRTSCTS) &&
843 			    (bits & TIOCM_RTS) != 0)
844 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR2,
845 				    CD1400_MSVR2_DTR);
846 			if (bits & TIOCM_DTR)
847 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR1,
848 				    CD1400_MSVR1_RTS);
849 		} else {
850 			if (!ISSET(tp->t_cflag, CRTSCTS) &&
851 			    (bits & TIOCM_RTS) != 0)
852 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR1,
853 				    CD1400_MSVR1_RTS);
854 			if (bits & TIOCM_DTR)
855 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR2,
856 				    CD1400_MSVR2_DTR);
857 		}
858 		break;
859 
860 	case DMBIC:		/* clear bits */
861 		if (cy->cy_clock == CY_CLOCK_60) {
862 			if (!ISSET(tp->t_cflag, CRTSCTS) && (bits & TIOCM_RTS))
863 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR2, 0);
864 			if (bits & TIOCM_DTR)
865 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR1, 0);
866 		} else {
867 			if (!ISSET(tp->t_cflag, CRTSCTS) && (bits & TIOCM_RTS))
868 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR1, 0);
869 			if (bits & TIOCM_DTR)
870 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR2, 0);
871 		}
872 		break;
873 	}
874 	splx(s);
875 	return ((howto == DMGET) ? bits : 0);
876 }
877 
878 /*
879  * Upper-level handler loop (called from timer interrupt?)
880  * This routine is common for multiple cards
881  */
882 void
883 cy_poll(void *arg)
884 {
885 	int card, port;
886 	struct cy_softc *sc;
887 	struct cy_port *cy;
888 	struct tty *tp;
889 	static int counter = 0;
890 #ifdef CY_DEBUG1
891 	int did_something;
892 #endif
893 	int s = spltty();
894 
895 	if (cy_events == 0 && ++counter < 200) {
896 		splx(s);
897 		goto out;
898 	}
899 	cy_events = 0;
900 	splx(s);
901 
902 	for (card = 0; card < cy_cd.cd_ndevs; card++) {
903 		sc = device_lookup_private(&cy_cd, card);
904 		if (sc == NULL)
905 			continue;
906 
907 #ifdef CY_DEBUG1
908 		sc->sc_poll_count1++;
909 		did_something = 0;
910 #endif
911 
912 		for (port = 0; port < sc->sc_nchannels; port++) {
913 			cy = &sc->sc_ports[port];
914 			if ((tp = cy->cy_tty) == NULL || cy->cy_ibuf == NULL ||
915 			    (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0))
916 				continue;
917 
918 			/*
919 		         * handle received data
920 		         */
921 			while (cy->cy_ibuf_rd_ptr != cy->cy_ibuf_wr_ptr) {
922 				u_char line_stat;
923 				int chr;
924 
925 				line_stat = cy->cy_ibuf_rd_ptr[0];
926 				chr = cy->cy_ibuf_rd_ptr[1];
927 
928 				if (line_stat &
929 				    (CD1400_RDSR_BREAK | CD1400_RDSR_FE))
930 					chr |= TTY_FE;
931 				if (line_stat & CD1400_RDSR_PE)
932 					chr |= TTY_PE;
933 
934 				/*
935 				 * on an overrun error the data is treated as
936 				 * good just as it should be.
937 				 */
938 
939 #ifdef CY_DEBUG
940 				aprint_debug_dev(sc->sc_dev,
941 				    "port %d ttyinput 0x%x\n",
942 				    port, chr);
943 #endif
944 
945 				(*tp->t_linesw->l_rint) (chr, tp);
946 
947 				s = spltty();	/* really necessary? */
948 				if ((cy->cy_ibuf_rd_ptr += 2) ==
949 				    cy->cy_ibuf_end)
950 					cy->cy_ibuf_rd_ptr = cy->cy_ibuf;
951 				splx(s);
952 
953 #ifdef CY_DEBUG1
954 				did_something = 1;
955 #endif
956 			}
957 
958 			/*
959 			 * If we don't have any received data in ibuf and
960 			 * CRTSCTS is on and RTS is turned off, it is time to
961 			 * turn RTS back on
962 			 */
963 			if (ISSET(tp->t_cflag, CRTSCTS)) {
964 				/*
965 				 * we can't use cy_modem_control() here as it
966 				 * doesn't change RTS if RTSCTS is on
967 				 */
968 				cd_write_reg(sc, cy->cy_chip, CD1400_CAR,
969 				    port & CD1400_CAR_CHAN);
970 
971 				if (cy->cy_clock == CY_CLOCK_60) {
972 				  if ((cd_read_reg(sc, cy->cy_chip,
973 				    CD1400_MSVR2) & CD1400_MSVR2_DTR) == 0) {
974 					cd_write_reg(sc, cy->cy_chip,
975 					CD1400_MSVR2,CD1400_MSVR2_DTR);
976 #ifdef CY_DEBUG1
977 					did_something = 1;
978 #endif
979 				  }
980 				} else {
981 				  if ((cd_read_reg(sc, cy->cy_chip,
982 				    CD1400_MSVR1) & CD1400_MSVR1_RTS) == 0) {
983 					cd_write_reg(sc, cy->cy_chip,
984 					CD1400_MSVR1,CD1400_MSVR1_RTS);
985 #ifdef CY_DEBUG1
986 					did_something = 1;
987 #endif
988 				  }
989 				}
990 			}
991 
992 			/*
993 		         * handle carrier changes
994 		         */
995 			s = spltty();
996 			if (ISSET(cy->cy_flags, CY_F_CARRIER_CHANGED)) {
997 				int             carrier;
998 
999 				CLR(cy->cy_flags, CY_F_CARRIER_CHANGED);
1000 				splx(s);
1001 
1002 				carrier = ((cy->cy_carrier_stat &
1003 				    CD1400_MSVR2_CD) != 0);
1004 
1005 #ifdef CY_DEBUG
1006 				printf("cy_poll: carrier change "
1007 				    "(card %d, port %d, carrier %d)\n",
1008 				    card, port, carrier);
1009 #endif
1010 				if (CY_DIALOUT(tp->t_dev) == 0 &&
1011 				    !(*tp->t_linesw->l_modem)(tp, carrier))
1012 					cy_modem_control(sc, cy,
1013 					    TIOCM_DTR, DMBIC);
1014 
1015 #ifdef CY_DEBUG1
1016 				did_something = 1;
1017 #endif
1018 			} else
1019 				splx(s);
1020 
1021 			s = spltty();
1022 			if (ISSET(cy->cy_flags, CY_F_START)) {
1023 				CLR(cy->cy_flags, CY_F_START);
1024 				splx(s);
1025 
1026 				(*tp->t_linesw->l_start) (tp);
1027 
1028 #ifdef CY_DEBUG1
1029 				did_something = 1;
1030 #endif
1031 			} else
1032 				splx(s);
1033 
1034 			/* could move this to even upper level... */
1035 			if (cy->cy_fifo_overruns) {
1036 				cy->cy_fifo_overruns = 0;
1037 				/*
1038 				 * doesn't report overrun count, but
1039 				 * shouldn't really matter
1040 				 */
1041 				log(LOG_WARNING, "%s: port %d fifo overrun\n",
1042 				    device_xname(sc->sc_dev), port);
1043 			}
1044 			if (cy->cy_ibuf_overruns) {
1045 				cy->cy_ibuf_overruns = 0;
1046 				log(LOG_WARNING, "%s: port %d ibuf overrun\n",
1047 				    device_xname(sc->sc_dev), port);
1048 			}
1049 		}		/* for(port...) */
1050 #ifdef CY_DEBUG1
1051 		if (did_something && counter >= 200)
1052 			sc->sc_poll_count2++;
1053 #endif
1054 	} /* for(card...) */
1055 
1056 	counter = 0;
1057 
1058 out:
1059 	callout_reset(&cy_poll_callout, 1, cy_poll, NULL);
1060 }
1061 
1062 /*
1063  * hardware interrupt routine
1064  */
1065 int
1066 cy_intr(void *arg)
1067 {
1068 	struct cy_softc *sc = arg;
1069 	struct cy_port *cy;
1070 	int cy_chip, stat;
1071 	int int_serviced = 0;
1072 
1073 	/*
1074 	 * Check interrupt status of each CD1400 chip on this card
1075 	 * (multiple cards cannot share the same interrupt)
1076 	 */
1077 	for (cy_chip = 0; cy_chip < sc->sc_nchips; cy_chip++) {
1078 
1079 		stat = cd_read_reg(sc, cy_chip, CD1400_SVRR);
1080 		if (stat == 0)
1081 			continue;
1082 
1083 		if (ISSET(stat, CD1400_SVRR_RXRDY)) {
1084 			u_char save_car, save_rir, serv_type;
1085 			u_char line_stat, recv_data, n_chars;
1086 			u_char *buf_p;
1087 
1088 			save_rir = cd_read_reg(sc, cy_chip, CD1400_RIR);
1089 			save_car = cd_read_reg(sc, cy_chip, CD1400_CAR);
1090 			/* enter rx service */
1091 			cd_write_reg(sc, cy_chip, CD1400_CAR, save_rir);
1092 
1093 			serv_type = cd_read_reg(sc, cy_chip, CD1400_RIVR);
1094 			cy = &sc->sc_ports[serv_type >> 3];
1095 
1096 #ifdef CY_DEBUG1
1097 			cy->cy_rx_int_count++;
1098 #endif
1099 
1100 			buf_p = cy->cy_ibuf_wr_ptr;
1101 
1102 			if (ISSET(serv_type, CD1400_RIVR_EXCEPTION)) {
1103 				line_stat = cd_read_reg(sc, cy->cy_chip,
1104 				    CD1400_RDSR);
1105 				recv_data = cd_read_reg(sc, cy->cy_chip,
1106 				    CD1400_RDSR);
1107 
1108 				if (cy->cy_tty == NULL ||
1109 				    !ISSET(cy->cy_tty->t_state, TS_ISOPEN))
1110 					goto end_rx_serv;
1111 
1112 #ifdef CY_DEBUG
1113 				aprint_debug_dev(
1114 				    sc->sc_dev,
1115 				    "port %d recv exception, "
1116 				    "line_stat 0x%x, char 0x%x\n",
1117 				    cy->cy_port_num, line_stat, recv_data);
1118 #endif
1119 				if (ISSET(line_stat, CD1400_RDSR_OE))
1120 					cy->cy_fifo_overruns++;
1121 
1122 				*buf_p++ = line_stat;
1123 				*buf_p++ = recv_data;
1124 				if (buf_p == cy->cy_ibuf_end)
1125 					buf_p = cy->cy_ibuf;
1126 
1127 				if (buf_p == cy->cy_ibuf_rd_ptr) {
1128 					if (buf_p == cy->cy_ibuf)
1129 						buf_p = cy->cy_ibuf_end;
1130 					buf_p -= 2;
1131 					cy->cy_ibuf_overruns++;
1132 				}
1133 				cy_events = 1;
1134 			} else {/* no exception, received data OK */
1135 				n_chars = cd_read_reg(sc, cy->cy_chip,
1136 				    CD1400_RDCR);
1137 
1138 				/* If no tty or not open, discard data */
1139 				if (cy->cy_tty == NULL ||
1140 				    !ISSET(cy->cy_tty->t_state, TS_ISOPEN)) {
1141 					while (n_chars--)
1142 						(void)cd_read_reg(sc,
1143 						    cy->cy_chip, CD1400_RDSR);
1144 					goto end_rx_serv;
1145 				}
1146 
1147 #ifdef CY_DEBUG
1148 				aprint_debug_dev(sc->sc_dev,
1149 				    "port %d receive ok %d chars\n",
1150 				    cy->cy_port_num, n_chars);
1151 #endif
1152 				while (n_chars--) {
1153 					*buf_p++ = 0;	/* status: OK */
1154 					/* data byte */
1155 					*buf_p++ = cd_read_reg(sc,
1156 					    cy->cy_chip, CD1400_RDSR);
1157 					if (buf_p == cy->cy_ibuf_end)
1158 						buf_p = cy->cy_ibuf;
1159 					if (buf_p == cy->cy_ibuf_rd_ptr) {
1160 						if (buf_p == cy->cy_ibuf)
1161 							buf_p = cy->cy_ibuf_end;
1162 						buf_p -= 2;
1163 						cy->cy_ibuf_overruns++;
1164 						break;
1165 					}
1166 				}
1167 				cy_events = 1;
1168 			}
1169 
1170 			cy->cy_ibuf_wr_ptr = buf_p;
1171 
1172 			/* RTS handshaking for incoming data */
1173 			if (ISSET(cy->cy_tty->t_cflag, CRTSCTS)) {
1174 				int bf, msvr;
1175 
1176 				bf = buf_p - cy->cy_ibuf_rd_ptr;
1177 				if (bf < 0)
1178 					bf += CY_IBUF_SIZE;
1179 
1180 				if (bf > (CY_IBUF_SIZE / 2)) {
1181 					/* turn RTS off */
1182 					if (cy->cy_clock == CY_CLOCK_60)
1183 						msvr = CD1400_MSVR2;
1184 					else
1185 						msvr = CD1400_MSVR1;
1186 					cd_write_reg(sc, cy->cy_chip, msvr, 0);
1187 				}
1188 			}
1189 
1190 	end_rx_serv:
1191 			/* terminate service context */
1192 			cd_write_reg(sc, cy->cy_chip, CD1400_RIR,
1193 				     save_rir & 0x3f);
1194 			cd_write_reg(sc, cy->cy_chip, CD1400_CAR, save_car);
1195 			int_serviced = 1;
1196 		} /* if (rx_service...) */
1197 		if (ISSET(stat, CD1400_SVRR_MDMCH)) {
1198 			u_char save_car, save_mir, serv_type, modem_stat;
1199 
1200 			save_mir = cd_read_reg(sc, cy_chip, CD1400_MIR);
1201 			save_car = cd_read_reg(sc, cy_chip, CD1400_CAR);
1202 			/* enter modem service */
1203 			cd_write_reg(sc, cy_chip, CD1400_CAR, save_mir);
1204 
1205 			serv_type = cd_read_reg(sc, cy_chip, CD1400_MIVR);
1206 			cy = &sc->sc_ports[serv_type >> 3];
1207 
1208 #ifdef CY_DEBUG1
1209 			cy->cy_modem_int_count++;
1210 #endif
1211 
1212 			modem_stat = cd_read_reg(sc, cy->cy_chip, CD1400_MSVR2);
1213 
1214 #ifdef CY_DEBUG
1215 			aprint_debug_dev(sc->sc_dev,
1216 			    "port %d modem line change, new stat 0x%x\n",
1217 			    cy->cy_port_num, modem_stat);
1218 #endif
1219 			if (ISSET((cy->cy_carrier_stat ^ modem_stat), CD1400_MSVR2_CD)) {
1220 				SET(cy->cy_flags, CY_F_CARRIER_CHANGED);
1221 				cy_events = 1;
1222 			}
1223 			cy->cy_carrier_stat = modem_stat;
1224 
1225 			/* terminate service context */
1226 			cd_write_reg(sc, cy->cy_chip, CD1400_MIR, save_mir & 0x3f);
1227 			cd_write_reg(sc, cy->cy_chip, CD1400_CAR, save_car);
1228 			int_serviced = 1;
1229 		} /* if (modem_service...) */
1230 		if (ISSET(stat, CD1400_SVRR_TXRDY)) {
1231 			u_char          save_car, save_tir, serv_type,
1232 			                count, ch;
1233 			struct tty     *tp;
1234 
1235 			save_tir = cd_read_reg(sc, cy_chip, CD1400_TIR);
1236 			save_car = cd_read_reg(sc, cy_chip, CD1400_CAR);
1237 			/* enter tx service */
1238 			cd_write_reg(sc, cy_chip, CD1400_CAR, save_tir);
1239 
1240 			serv_type = cd_read_reg(sc, cy_chip, CD1400_TIVR);
1241 			cy = &sc->sc_ports[serv_type >> 3];
1242 
1243 #ifdef CY_DEBUG1
1244 			cy->cy_tx_int_count++;
1245 #endif
1246 #ifdef CY_DEBUG
1247 			aprint_debug_dev(sc->sc_dev, "port %d tx service\n",
1248 			    cy->cy_port_num);
1249 #endif
1250 
1251 			/* stop transmitting if no tty or CY_F_STOP set */
1252 			tp = cy->cy_tty;
1253 			if (tp == NULL || ISSET(cy->cy_flags, CY_F_STOP))
1254 				goto txdone;
1255 
1256 			count = 0;
1257 			if (ISSET(cy->cy_flags, CY_F_SEND_NUL)) {
1258 				cd_write_reg(sc, cy->cy_chip, CD1400_TDR, 0);
1259 				cd_write_reg(sc, cy->cy_chip, CD1400_TDR, 0);
1260 				count += 2;
1261 				CLR(cy->cy_flags, CY_F_SEND_NUL);
1262 			}
1263 			if (tp->t_outq.c_cc > 0) {
1264 				SET(tp->t_state, TS_BUSY);
1265 				while (tp->t_outq.c_cc > 0 &&
1266 				    count < CD1400_TX_FIFO_SIZE) {
1267 					ch = getc(&tp->t_outq);
1268 					/*
1269 					 * remember to double NUL characters
1270 					 * because embedded transmit commands
1271 					 * are enabled
1272 					 */
1273 					if (ch == 0) {
1274 						if (count >= CD1400_TX_FIFO_SIZE - 2) {
1275 							SET(cy->cy_flags, CY_F_SEND_NUL);
1276 							break;
1277 						}
1278 						cd_write_reg(sc, cy->cy_chip,
1279 						    CD1400_TDR, ch);
1280 						count++;
1281 					}
1282 					cd_write_reg(sc, cy->cy_chip,
1283 					    CD1400_TDR, ch);
1284 					count++;
1285 				}
1286 			} else {
1287 				/*
1288 				 * no data to send -- check if we should
1289 				 * start/stop a break
1290 				 */
1291 				/*
1292 				 * XXX does this cause too much delay before
1293 				 * breaks?
1294 				 */
1295 				if (ISSET(cy->cy_flags, CY_F_START_BREAK)) {
1296 					cd_write_reg(sc, cy->cy_chip,
1297 					    CD1400_TDR, 0);
1298 					cd_write_reg(sc, cy->cy_chip,
1299 					    CD1400_TDR, 0x81);
1300 					CLR(cy->cy_flags, CY_F_START_BREAK);
1301 				}
1302 				if (ISSET(cy->cy_flags, CY_F_END_BREAK)) {
1303 					cd_write_reg(sc, cy->cy_chip,
1304 					    CD1400_TDR, 0);
1305 					cd_write_reg(sc, cy->cy_chip,
1306 					    CD1400_TDR, 0x83);
1307 					CLR(cy->cy_flags, CY_F_END_BREAK);
1308 				}
1309 			}
1310 
1311 			if (tp->t_outq.c_cc == 0) {
1312 		txdone:
1313 				/*
1314 				 * No data to send or requested to stop.
1315 				 * Disable transmit interrupt
1316 				 */
1317 				cd_write_reg(sc, cy->cy_chip, CD1400_SRER,
1318 				     cd_read_reg(sc, cy->cy_chip, CD1400_SRER)
1319 				     & ~CD1400_SRER_TXRDY);
1320 				CLR(cy->cy_flags, CY_F_STOP);
1321 				CLR(tp->t_state, TS_BUSY);
1322 			}
1323 			if (tp->t_outq.c_cc <= tp->t_lowat) {
1324 				SET(cy->cy_flags, CY_F_START);
1325 				cy_events = 1;
1326 			}
1327 			/* terminate service context */
1328 			cd_write_reg(sc, cy->cy_chip, CD1400_TIR, save_tir & 0x3f);
1329 			cd_write_reg(sc, cy->cy_chip, CD1400_CAR, save_car);
1330 			int_serviced = 1;
1331 		}		/* if (tx_service...) */
1332 	}			/* for(...all CD1400s on a card) */
1333 
1334 	/* ensure an edge for next interrupt */
1335 	bus_space_write_1(sc->sc_memt, sc->sc_bsh,
1336 			CY_CLEAR_INTR << sc->sc_bustype, 0);
1337 	return int_serviced;
1338 }
1339 
1340 /*
1341  * subroutine to enable CD1400 transmitter
1342  */
1343 void
1344 cy_enable_transmitter(struct cy_softc *sc, struct cy_port *cy)
1345 {
1346 	int s = spltty();
1347 	cd_write_reg(sc, cy->cy_chip, CD1400_CAR,
1348 	    cy->cy_port_num & CD1400_CAR_CHAN);
1349 	cd_write_reg(sc, cy->cy_chip, CD1400_SRER,
1350 	    cd_read_reg(sc, cy->cy_chip, CD1400_SRER) | CD1400_SRER_TXRDY);
1351 	splx(s);
1352 }
1353 
1354 /*
1355  * Execute a CD1400 channel command
1356  */
1357 void
1358 cd1400_channel_cmd(struct cy_softc *sc, struct cy_port *cy, int cmd)
1359 {
1360 	u_int waitcnt = 5 * 8 * 1024;	/* approx 5 ms */
1361 
1362 #ifdef CY_DEBUG
1363 	printf("c1400_channel_cmd cy %p command 0x%x\n", cy, cmd);
1364 #endif
1365 
1366 	/* wait until cd1400 is ready to process a new command */
1367 	while (cd_read_reg(sc, cy->cy_chip, CD1400_CCR) != 0 && waitcnt-- > 0);
1368 
1369 	if (waitcnt == 0)
1370 		log(LOG_ERR, "%s: channel command timeout\n",
1371 		    device_xname(sc->sc_dev));
1372 
1373 	cd_write_reg(sc, cy->cy_chip, CD1400_CCR, cmd);
1374 }
1375 
1376 /*
1377  * Compute clock option register and baud rate register values
1378  * for a given speed. Return 0 on success, -1 on failure.
1379  *
1380  * The error between requested and actual speed seems
1381  * to be well within allowed limits (less than 3%)
1382  * with every speed value between 50 and 150000 bps.
1383  */
1384 int
1385 cy_speed(speed_t speed, int *cor, int *bpr, int cy_clock)
1386 {
1387 	int c, co, br;
1388 
1389 	if (speed < 50 || speed > 150000)
1390 		return -1;
1391 
1392 	for (c = 0, co = 8; co <= 2048; co <<= 2, c++) {
1393 		br = (cy_clock + (co * speed) / 2) / (co * speed);
1394 		if (br < 0x100) {
1395 			*bpr = br;
1396 			*cor = c;
1397 			return 0;
1398 		}
1399 	}
1400 
1401 	return -1;
1402 }
1403