xref: /netbsd-src/sys/dev/ic/cy.c (revision 3b01aba77a7a698587faaae455bbfe740923c1f5)
1 /*	$NetBSD: cy.c,v 1.23 2001/07/07 16:13:47 thorpej 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/types.h>
19 #include <sys/param.h>
20 #include <sys/ioctl.h>
21 #include <sys/syslog.h>
22 #include <sys/fcntl.h>
23 #include <sys/tty.h>
24 #include <sys/proc.h>
25 #include <sys/conf.h>
26 #include <sys/user.h>
27 #include <sys/ioctl.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 
34 #include <machine/bus.h>
35 
36 #include <dev/ic/cd1400reg.h>
37 #include <dev/ic/cyreg.h>
38 #include <dev/ic/cyvar.h>
39 
40 /* Macros to clear/set/test flags. */
41 #define	SET(t, f)	(t) |= (f)
42 #define	CLR(t, f)	(t) &= ~(f)
43 #define	ISSET(t, f)	((t) & (f))
44 
45 int	cyparam(struct tty *, struct termios *);
46 void	cystart(struct tty *);
47 void	cy_poll(void *);
48 int	cy_modem_control(struct cy_softc *, struct cy_port *, int, int);
49 void	cy_enable_transmitter(struct cy_softc *, struct cy_port *);
50 void	cd1400_channel_cmd(struct cy_softc *, struct cy_port *, int);
51 int	cy_speed(speed_t, int *, int *, int);
52 
53 extern struct cfdriver cy_cd;
54 
55 static int      cy_open = 0;
56 static int      cy_events = 0;
57 
58 int	cy_attached_ttys;
59 
60 cdev_decl(cy);
61 
62 struct callout cy_poll_callout = CALLOUT_INITIALIZER;
63 
64 /*
65  * Common probe routine
66  */
67 int
68 cy_find(struct cy_softc *sc)
69 {
70 	int cy_chip, chip;
71 	u_char firmware_ver;
72 	bus_space_tag_t tag = sc->sc_memt;
73 	bus_space_handle_t bsh = sc->sc_bsh;
74 	int bustype = sc->sc_bustype;
75 
76 	/* Cyclom card hardware reset */
77 	bus_space_write_1(tag, bsh, CY16_RESET << bustype, 0);
78 	DELAY(500);		/* wait for reset to complete */
79 	bus_space_write_1(tag, bsh, CY_CLEAR_INTR << bustype, 0);
80 
81 #ifdef CY_DEBUG
82 	printf("cy: card reset done\n");
83 #endif
84 	sc->sc_nchips = 0;
85 
86 	for (cy_chip = 0, chip = 0; cy_chip < CY_MAX_CD1400s;
87 	    cy_chip++, chip += (CY_CD1400_MEMSPACING << bustype)) {
88 		int i;
89 
90 		/*
91 		 * the last 4 nchips are 'interleaved' with the first 4 on
92 		 * 32-port boards
93 		 */
94 		if (cy_chip == 4)
95 			chip -= (CY32_ADDR_FIX << bustype);
96 
97 #ifdef CY_DEBUG
98 		printf("%s probe chip %d offset 0x%x ... ",
99 		    sc->sc_dev.dv_xname, cy_chip, chip);
100 #endif
101 
102 		/* wait until the chip is ready for command */
103 		DELAY(1000);
104 		if (bus_space_read_1(tag, bsh, chip +
105 		    ((CD1400_CCR << 1) << bustype)) != 0) {
106 #ifdef CY_DEBUG
107 			printf("not ready for command\n");
108 #endif
109 			break;
110 		}
111 		/* clear the firmware version reg. */
112 		bus_space_write_1(tag, bsh, chip +
113 		    ((CD1400_GFRCR << 1) << bustype), 0);
114 
115 		/*
116 	         * On Cyclom-16 references to non-existent chip 4
117 	         * actually access chip 0 (address line 9 not decoded).
118 	         * Here we check if the clearing of chip 4 GFRCR actually
119 	         * cleared chip 0 GFRCR. In that case we have a 16 port card.
120 	         */
121 		if (cy_chip == 4 &&
122 		    bus_space_read_1(tag, bsh, /* off for chip 0 (0) + */
123 		       ((CD1400_GFRCR << 1) << bustype)) == 0)
124 			break;
125 
126 		/* reset the chip */
127 		bus_space_write_1(tag, bsh, chip +
128 		    ((CD1400_CCR << 1) << bustype),
129 		    CD1400_CCR_CMDRESET | CD1400_CCR_FULLRESET);
130 
131 		/* wait for the chip to initialize itself */
132 		for (i = 0; i < 200; i++) {
133 			DELAY(50);
134 			firmware_ver = bus_space_read_1(tag, bsh, chip +
135 			    ((CD1400_GFRCR << 1) << bustype));
136 			if ((firmware_ver & 0xf0) == 0x40) /* found a CD1400 */
137 				break;
138 		}
139 #ifdef CY_DEBUG
140 		printf("firmware version 0x%x\n", firmware_ver);
141 #endif
142 
143 		if ((firmware_ver & 0xf0) != 0x40)
144 			break;
145 
146 		/* firmware version OK, CD1400 found */
147 		sc->sc_nchips++;
148 	}
149 
150 	if (sc->sc_nchips == 0) {
151 #ifdef CY_DEBUG
152 		printf("no CD1400s found\n");
153 #endif
154 		return 0;
155 	}
156 #ifdef CY_DEBUG
157 	printf("found %d CD1400s\n", sc->sc_nchips);
158 #endif
159 
160 	return 1;
161 }
162 
163 void
164 cy_attach(struct cy_softc *sc)
165 {
166 	int port, cy_chip, num_chips, cdu, chip;
167 	int cy_clock;
168 
169 	num_chips = sc->sc_nchips;
170 	if (num_chips == 0)
171 		return;
172 
173 	memset(sc->sc_ports, 0, sizeof(sc->sc_ports));
174 
175 	port = 0;
176 	for (cy_chip = 0, chip = 0; cy_chip < num_chips; cy_chip++,
177 	    chip += (CY_CD1400_MEMSPACING << sc->sc_bustype)) {
178 
179 		if (cy_chip == 4)
180 			chip -= (CY32_ADDR_FIX << sc->sc_bustype);
181 
182 #ifdef CY_DEBUG
183 		printf("attach CD1400 #%d offset 0x%x\n", cy_chip, chip);
184 #endif
185 		sc->sc_cd1400_offs[cy_chip] = chip;
186 
187 		/*
188 		 * configure port 0 as serial port (should already be after
189 		 * reset)
190 		 */
191 		cd_write_reg(sc, cy_chip, CD1400_GCR, 0);
192 
193 		if (cd_read_reg(sc, cy_chip, CD1400_GFRCR) <= 0x46)
194 			cy_clock = CY_CLOCK;
195 		else
196 			cy_clock = CY_CLOCK_60;
197 
198 		/* set up a receive timeout period (1ms) */
199 		cd_write_reg(sc, cy_chip, CD1400_PPR,
200 		    (cy_clock / CD1400_PPR_PRESCALER / 1000) + 1);
201 
202 		for (cdu = 0; cdu < CD1400_NO_OF_CHANNELS; cdu++) {
203 			sc->sc_ports[port].cy_softc = sc;
204 			sc->sc_ports[port].cy_port_num = port;
205 			sc->sc_ports[port].cy_chip = cy_chip;
206 			sc->sc_ports[port].cy_clock = cy_clock;
207 
208 			/* should we initialize anything else here? */
209 			port++;
210 		} /* for(each port on one CD1400...) */
211 
212 	} /* for(each CD1400 on a card... ) */
213 
214 	sc->sc_nchannels = port;
215 
216 	printf("%s: %d channels (ttyCY%03d..ttyCY%03d)\n",
217 	    sc->sc_dev.dv_xname, sc->sc_nchannels, cy_attached_ttys,
218 	    cy_attached_ttys + (sc->sc_nchannels - 1));
219 
220 	cy_attached_ttys += sc->sc_nchannels;
221 
222 	/* ensure an edge for the next interrupt */
223 	bus_space_write_1(sc->sc_memt, sc->sc_bsh,
224 	    CY_CLEAR_INTR << sc->sc_bustype, 0);
225 }
226 
227 #define	CYDIALOUT_MASK		0x80000
228 #define	CY_DIALOUT(dev)		(minor(dev) & CYDIALOUT_MASK)
229 
230 #define	CY_PORT(dev)		cy_getport((dev))
231 #define	CY_BOARD(cy)		((cy)->cy_softc)
232 
233 static struct cy_port *
234 cy_getport(dev_t dev)
235 {
236 	int i, j, k, u = minor(dev) & ~CYDIALOUT_MASK;
237 	struct cy_softc *sc;
238 
239 	for (i = 0, j = 0; i < cy_cd.cd_ndevs; i++) {
240 		k = j;
241 		sc = device_lookup(&cy_cd, i);
242 		if (sc == NULL)
243 			continue;
244 		if (sc->sc_nchannels == 0)
245 			continue;
246 		j += sc->sc_nchannels;
247 		if (j > u)
248 			break;
249 	}
250 
251 	if (i == cy_cd.cd_ndevs)
252 		return (NULL);
253 	else
254 		return (&sc->sc_ports[u - k]);
255 }
256 
257 /*
258  * open routine. returns zero if successfull, else error code
259  */
260 int
261 cyopen(dev_t dev, int flag, int mode, struct proc *p)
262 {
263 	struct cy_softc *sc;
264 	struct cy_port *cy;
265 	struct tty *tp;
266 	int s, error;
267 
268 	cy = CY_PORT(dev);
269 	if (cy == NULL)
270 		return (ENXIO);
271 	sc = CY_BOARD(cy);
272 
273 	s = spltty();
274 	if (cy->cy_tty == NULL) {
275 		if ((cy->cy_tty = ttymalloc()) == NULL) {
276 			splx(s);
277 			printf("%s: port %d: can't allocate tty\n",
278 			    sc->sc_dev.dv_xname, cy->cy_port_num);
279 			return (ENOMEM);
280 		}
281 		tty_attach(cy->cy_tty);
282 	}
283 	splx(s);
284 
285 	tp = cy->cy_tty;
286 	tp->t_oproc = cystart;
287 	tp->t_param = cyparam;
288 	tp->t_dev = dev;
289 
290 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
291 		ttychars(tp);
292 		tp->t_iflag = TTYDEF_IFLAG;
293 		tp->t_oflag = TTYDEF_OFLAG;
294 		tp->t_cflag = TTYDEF_CFLAG;
295 		if (ISSET(cy->cy_openflags, TIOCFLAG_CLOCAL))
296 			SET(tp->t_cflag, CLOCAL);
297 		if (ISSET(cy->cy_openflags, TIOCFLAG_CRTSCTS))
298 			SET(tp->t_cflag, CRTSCTS);
299 		if (ISSET(cy->cy_openflags, TIOCFLAG_MDMBUF))
300 			SET(tp->t_cflag, MDMBUF);
301 		tp->t_lflag = TTYDEF_LFLAG;
302 		tp->t_ispeed = tp->t_ospeed = TTYDEF_SPEED;
303 
304 		s = spltty();
305 
306 		/*
307 		 * Allocate input ring buffer if we don't already have one
308 		 */
309 		if (cy->cy_ibuf == NULL) {
310 			cy->cy_ibuf = malloc(CY_IBUF_SIZE, M_DEVBUF, M_NOWAIT);
311 			if (cy->cy_ibuf == NULL) {
312 				printf("%s: port %d: can't allocate input buffer\n",
313 				       sc->sc_dev.dv_xname, cy->cy_port_num);
314 				splx(s);
315 				return ENOMEM;
316 			}
317 			cy->cy_ibuf_end = cy->cy_ibuf + CY_IBUF_SIZE;
318 		}
319 		/* mark the ring buffer as empty */
320 		cy->cy_ibuf_rd_ptr = cy->cy_ibuf_wr_ptr = cy->cy_ibuf;
321 
322 		/* select CD1400 channel */
323 		cd_write_reg(sc, cy->cy_chip, CD1400_CAR,
324 		    cy->cy_port_num & CD1400_CAR_CHAN);
325 		/* reset the channel */
326 		cd1400_channel_cmd(sc, cy, CD1400_CCR_CMDRESET);
327 		/* encode unit (port) number in LIVR */
328 		/* there is just enough space for 5 bits (32 ports) */
329 		cd_write_reg(sc, cy->cy_chip, CD1400_LIVR,
330 		    cy->cy_port_num << 3);
331 
332 		cy->cy_channel_control = 0;
333 
334 		/* hmm... need spltty() here? */
335 		if (cy_open == 0) {
336 			cy_open = 1;
337 			callout_reset(&cy_poll_callout, 1, cy_poll, NULL);
338 		}
339 		/* this sets parameters and raises DTR */
340 		cyparam(tp, &tp->t_termios);
341 
342 		ttsetwater(tp);
343 
344 		/* raise RTS too */
345 		cy_modem_control(sc, cy, TIOCM_RTS, DMBIS);
346 
347 		cy->cy_carrier_stat =
348 			cd_read_reg(sc, cy->cy_chip, CD1400_MSVR2);
349 
350 		/* enable receiver and modem change interrupts */
351 		cd_write_reg(sc, cy->cy_chip, CD1400_SRER,
352 		    CD1400_SRER_MDMCH | CD1400_SRER_RXDATA);
353 
354 		if (CY_DIALOUT(dev) ||
355 		    ISSET(cy->cy_openflags, TIOCFLAG_SOFTCAR) ||
356 		    ISSET(tp->t_cflag, MDMBUF) ||
357 		    ISSET(cy->cy_carrier_stat, CD1400_MSVR2_CD))
358 			SET(tp->t_state, TS_CARR_ON);
359 		else
360 			CLR(tp->t_state, TS_CARR_ON);
361 	} else if (ISSET(tp->t_state, TS_XCLUDE) && p->p_ucred->cr_uid != 0) {
362 		return EBUSY;
363 	} else {
364 		s = spltty();
365 	}
366 
367 	/* wait for carrier if necessary */
368 	if (!ISSET(flag, O_NONBLOCK)) {
369 		while (!ISSET(tp->t_cflag, CLOCAL) &&
370 		    !ISSET(tp->t_state, TS_CARR_ON)) {
371 			tp->t_wopen++;
372 			error = ttysleep(tp, &tp->t_rawq, TTIPRI | PCATCH,
373 			    "cydcd", 0);
374 			tp->t_wopen--;
375 			if (error != 0) {
376 				splx(s);
377 				return error;
378 			}
379 		}
380 	}
381 	splx(s);
382 
383 	return (*tp->t_linesw->l_open) (dev, tp);
384 }
385 
386 /*
387  * close routine. returns zero if successfull, else error code
388  */
389 int
390 cyclose(dev_t dev, int flag, int mode, struct proc *p)
391 {
392 	struct cy_softc *sc;
393 	struct cy_port *cy;
394 	struct tty *tp;
395 	int s;
396 
397 	cy = CY_PORT(dev);
398 	sc = CY_BOARD(cy);
399 	tp = cy->cy_tty;
400 
401 	(*tp->t_linesw->l_close) (tp, flag);
402 	s = spltty();
403 
404 	if (ISSET(tp->t_cflag, HUPCL) &&
405 	    !ISSET(cy->cy_openflags, TIOCFLAG_SOFTCAR)) {
406 		/*
407 		 * drop DTR and RTS (should we wait for output buffer to
408 		 * become empty first?)
409 		 */
410 		cy_modem_control(sc, cy, 0, DMSET);
411 	}
412 	/*
413 	 * XXX should we disable modem change and
414 	 * receive interrupts here or somewhere ?
415 	 */
416 	CLR(tp->t_state, TS_BUSY | TS_FLUSH);
417 
418 	splx(s);
419 	ttyclose(tp);
420 
421 	return 0;
422 }
423 
424 /*
425  * Read routine
426  */
427 int
428 cyread(dev_t dev, struct uio *uio, int flag)
429 {
430 	struct cy_port *cy;
431 	struct tty *tp;
432 
433 	cy = CY_PORT(dev);
434 	tp = cy->cy_tty;
435 
436 	return ((*tp->t_linesw->l_read)(tp, uio, flag));
437 }
438 
439 /*
440  * Write routine
441  */
442 int
443 cywrite(dev_t dev, struct uio *uio, int flag)
444 {
445 	struct cy_port *cy;
446 	struct tty *tp;
447 
448 	cy = CY_PORT(dev);
449 	tp = cy->cy_tty;
450 
451 	return ((*tp->t_linesw->l_write)(tp, uio, flag));
452 }
453 
454 /*
455  * Poll routine
456  */
457 int
458 cypoll(dev, events, p)
459 	dev_t dev;
460 	int events;
461 	struct proc *p;
462 {
463 	struct cy_port *cy;
464 	struct tty *tp;
465 
466 	cy = CY_PORT(dev);
467 	tp = cy->cy_tty;
468 
469 	return ((*tp->t_linesw->l_poll)(tp, events, p));
470 }
471 
472 /*
473  * return tty pointer
474  */
475 struct tty *
476 cytty(dev_t dev)
477 {
478 	struct cy_port *cy;
479 
480 	cy = CY_PORT(dev);
481 
482 	return (cy->cy_tty);
483 }
484 
485 /*
486  * ioctl routine
487  */
488 int
489 cyioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct proc *p)
490 {
491 	struct cy_softc *sc;
492 	struct cy_port *cy;
493 	struct tty *tp;
494 	int error;
495 
496 	cy = CY_PORT(dev);
497 	sc = CY_BOARD(cy);
498 	tp = cy->cy_tty;
499 
500 	error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, p);
501 	if (error >= 0)
502 		return error;
503 
504 	error = ttioctl(tp, cmd, data, flag, p);
505 	if (error >= 0)
506 		return error;
507 
508 	/* XXX should not allow dropping DTR when dialin? */
509 
510 	switch (cmd) {
511 	case TIOCSBRK:		/* start break */
512 		SET(cy->cy_flags, CY_F_START_BREAK);
513 		cy_enable_transmitter(sc, cy);
514 		break;
515 
516 	case TIOCCBRK:		/* stop break */
517 		SET(cy->cy_flags, CY_F_END_BREAK);
518 		cy_enable_transmitter(sc, cy);
519 		break;
520 
521 	case TIOCSDTR:		/* DTR on */
522 		cy_modem_control(sc, cy, TIOCM_DTR, DMBIS);
523 		break;
524 
525 	case TIOCCDTR:		/* DTR off */
526 		cy_modem_control(sc, cy, TIOCM_DTR, DMBIC);
527 		break;
528 
529 	case TIOCMSET:		/* set new modem control line values */
530 		cy_modem_control(sc, cy, *((int *) data), DMSET);
531 		break;
532 
533 	case TIOCMBIS:		/* turn modem control bits on */
534 		cy_modem_control(sc, cy, *((int *) data), DMBIS);
535 		break;
536 
537 	case TIOCMBIC:		/* turn modem control bits off */
538 		cy_modem_control(sc, cy, *((int *) data), DMBIC);
539 		break;
540 
541 	case TIOCMGET:		/* get modem control/status line state */
542 		*((int *) data) = cy_modem_control(sc, cy, 0, DMGET);
543 		break;
544 
545 	case TIOCGFLAGS:
546 		*((int *) data) = cy->cy_openflags |
547 			(CY_DIALOUT(dev) ? TIOCFLAG_SOFTCAR : 0);
548 		break;
549 
550 	case TIOCSFLAGS:
551 		error = suser(p->p_ucred, &p->p_acflag);
552 		if (error != 0)
553 			return EPERM;
554 
555 		cy->cy_openflags = *((int *) data) &
556 		    (TIOCFLAG_SOFTCAR | TIOCFLAG_CLOCAL |
557 		     TIOCFLAG_CRTSCTS | TIOCFLAG_MDMBUF);
558 		break;
559 
560 	default:
561 		return ENOTTY;
562 	}
563 
564 	return 0;
565 }
566 
567 /*
568  * start output
569  */
570 void
571 cystart(struct tty *tp)
572 {
573 	struct cy_softc *sc;
574 	struct cy_port *cy;
575 	int s;
576 
577 	cy = CY_PORT(tp->t_dev);
578 	sc = cy->cy_softc;
579 
580 	s = spltty();
581 
582 #ifdef CY_DEBUG1
583 	cy->cy_start_count++;
584 #endif
585 
586 	if (!ISSET(tp->t_state, TS_TTSTOP | TS_TIMEOUT | TS_BUSY)) {
587 		if (tp->t_outq.c_cc <= tp->t_lowat) {
588 			if (ISSET(tp->t_state, TS_ASLEEP)) {
589 				CLR(tp->t_state, TS_ASLEEP);
590 				wakeup(&tp->t_outq);
591 			}
592 			selwakeup(&tp->t_wsel);
593 
594 			if (tp->t_outq.c_cc == 0)
595 				goto out;
596 		}
597 		SET(tp->t_state, TS_BUSY);
598 		cy_enable_transmitter(sc, cy);
599 	}
600 out:
601 
602 	splx(s);
603 }
604 
605 /*
606  * stop output
607  */
608 void
609 cystop(struct tty *tp, int flag)
610 {
611 	struct cy_port *cy;
612 	int s;
613 
614 	cy = CY_PORT(tp->t_dev);
615 
616 	s = spltty();
617 	if (ISSET(tp->t_state, TS_BUSY)) {
618 		if (!ISSET(tp->t_state, TS_TTSTOP))
619 			SET(tp->t_state, TS_FLUSH);
620 
621 		/*
622 		 * the transmit interrupt routine will disable transmit when it
623 		 * notices that CY_F_STOP has been set.
624 		 */
625 		SET(cy->cy_flags, CY_F_STOP);
626 	}
627 	splx(s);
628 }
629 
630 /*
631  * parameter setting routine.
632  * returns 0 if successfull, else returns error code
633  */
634 int
635 cyparam(struct tty *tp, struct termios *t)
636 {
637 	struct cy_softc *sc;
638 	struct cy_port *cy;
639 	int ibpr, obpr, i_clk_opt, o_clk_opt, s, opt;
640 
641 	cy = CY_PORT(tp->t_dev);
642 	sc = CY_BOARD(cy);
643 
644 	if (t->c_ospeed != 0 && cy_speed(t->c_ospeed, &o_clk_opt, &obpr, cy->cy_clock) < 0)
645 		return EINVAL;
646 
647 	if (t->c_ispeed != 0 && cy_speed(t->c_ispeed, &i_clk_opt, &ibpr, cy->cy_clock) < 0)
648 		return EINVAL;
649 
650 	s = spltty();
651 
652 	/* hang up the line is ospeed is zero, else turn DTR on */
653 	cy_modem_control(sc, cy, TIOCM_DTR, (t->c_ospeed == 0 ? DMBIC : DMBIS));
654 
655 	/* channel was selected by the above call to cy_modem_control() */
656 #if 0
657 	cd_write_reg(sc, cy->cy_chip, CD1400_CAR, port & CD1400_CAR_CHAN);
658 #endif
659 
660 	/* set transmit speed */
661 	if (t->c_ospeed != 0) {
662 		cd_write_reg(sc, cy->cy_chip, CD1400_TCOR, o_clk_opt);
663 		cd_write_reg(sc, cy->cy_chip, CD1400_TBPR, obpr);
664 	}
665 	/* set receive speed */
666 	if (t->c_ispeed != 0) {
667 		cd_write_reg(sc, cy->cy_chip, CD1400_RCOR, i_clk_opt);
668 		cd_write_reg(sc, cy->cy_chip, CD1400_RBPR, ibpr);
669 	}
670 	opt = CD1400_CCR_CMDCHANCTL | CD1400_CCR_XMTEN
671 		| (ISSET(t->c_cflag, CREAD) ? CD1400_CCR_RCVEN : CD1400_CCR_RCVDIS);
672 
673 	if (opt != cy->cy_channel_control) {
674 		cy->cy_channel_control = opt;
675 		cd1400_channel_cmd(sc, cy, opt);
676 	}
677 	/* compute COR1 contents */
678 	opt = 0;
679 	if (ISSET(t->c_cflag, PARENB)) {
680 		if (ISSET(t->c_cflag, PARODD))
681 			opt |= CD1400_COR1_PARODD;
682 		opt |= CD1400_COR1_PARNORMAL;
683 	}
684 	if (!ISSET(t->c_iflag, INPCK))
685 		opt |= CD1400_COR1_NOINPCK;	/* no parity checking */
686 
687 	if (ISSET(t->c_cflag, CSTOPB))
688 		opt |= CD1400_COR1_STOP2;
689 
690 	switch (t->c_cflag & CSIZE) {
691 	case CS5:
692 		opt |= CD1400_COR1_CS5;
693 		break;
694 
695 	case CS6:
696 		opt |= CD1400_COR1_CS6;
697 		break;
698 
699 	case CS7:
700 		opt |= CD1400_COR1_CS7;
701 		break;
702 
703 	default:
704 		opt |= CD1400_COR1_CS8;
705 		break;
706 	}
707 
708 	cd_write_reg(sc, cy->cy_chip, CD1400_COR1, opt);
709 
710 #ifdef CY_DEBUG
711 	printf("cor1 = 0x%x...", opt);
712 #endif
713 
714 	/*
715 	 * use the CD1400 automatic CTS flow control if CRTSCTS is set
716 	 *
717 	 * CD1400_COR2_ETC is used because breaks are generated with
718 	 * embedded transmit commands
719 	 */
720 	cd_write_reg(sc, cy->cy_chip, CD1400_COR2,
721 		     CD1400_COR2_ETC |
722 		 (ISSET(t->c_cflag, CRTSCTS) ? CD1400_COR2_CCTS_OFLOW : 0));
723 
724 	cd_write_reg(sc, cy->cy_chip, CD1400_COR3, CY_RX_FIFO_THRESHOLD);
725 
726 	cd1400_channel_cmd(sc, cy, CD1400_CCR_CMDCORCHG |
727 	    CD1400_CCR_COR1 | CD1400_CCR_COR2 | CD1400_CCR_COR3);
728 
729 	cd_write_reg(sc, cy->cy_chip, CD1400_COR4, CD1400_COR4_PFO_EXCEPTION);
730 	cd_write_reg(sc, cy->cy_chip, CD1400_COR5, 0);
731 
732 	/*
733          * set modem change option registers to generate interrupts
734          * on carrier detect changes.
735          *
736          * if hardware RTS handshaking is used
737          * also set the handshaking threshold.
738          */
739 	if (cy->cy_clock == CY_CLOCK_60) {
740 	   cd_write_reg(sc, cy->cy_chip, CD1400_MCOR1, CD1400_MCOR1_CDzd |
741     	      (ISSET(t->c_cflag, CRTSCTS) ? CY_RX_DTR_THRESHOLD : 0));
742 	} else {
743 	   cd_write_reg(sc, cy->cy_chip, CD1400_MCOR1, CD1400_MCOR1_CDzd);
744 	}
745 
746 	cd_write_reg(sc, cy->cy_chip, CD1400_MCOR2, CD1400_MCOR2_CDod);
747 
748 	/*
749          * set receive timeout to approx. 2ms
750          * could use more complex logic here...
751          * (but is it actually needed or even useful?)
752          */
753 	cd_write_reg(sc, cy->cy_chip, CD1400_RTPR, 2);
754 
755 	/*
756          * should do anything else here?
757          * XXX check MDMBUF handshaking like in com.c?
758          */
759 
760 	splx(s);
761 	return 0;
762 }
763 
764 /*
765  * set/get modem line status
766  *
767  * bits can be: TIOCM_DTR, TIOCM_RTS, TIOCM_CTS, TIOCM_CD, TIOCM_RI, TIOCM_DSR
768  */
769 int
770 cy_modem_control(struct cy_softc *sc, struct cy_port *cy, int bits, int howto)
771 {
772 	struct tty *tp = cy->cy_tty;
773 	int s, msvr;
774 
775 	s = spltty();
776 
777 	/* select channel */
778 	cd_write_reg(sc, cy->cy_chip, CD1400_CAR,
779 	    cy->cy_port_num & CD1400_CAR_CHAN);
780 
781 	/* Does not manipulate RTS if it is used for flow control. */
782 	switch (howto) {
783 	case DMGET:
784 		bits = 0;
785 		if (cy->cy_channel_control & CD1400_CCR_RCVEN)
786 			bits |= TIOCM_LE;
787 		msvr = cd_read_reg(sc, cy->cy_chip, CD1400_MSVR2);
788 		if (cy->cy_clock == CY_CLOCK_60) {
789 			if (cd_read_reg(sc, cy->cy_chip, CD1400_MSVR1) &
790 		    		CD1400_MSVR1_RTS)
791 				bits |= TIOCM_DTR;
792 			if (msvr & CD1400_MSVR2_DTR)
793 				bits |= TIOCM_RTS;
794 		} else {
795 			if (cd_read_reg(sc, cy->cy_chip, CD1400_MSVR1) &
796 			    CD1400_MSVR1_RTS)
797 				bits |= TIOCM_RTS;
798 			if (msvr & CD1400_MSVR2_DTR)
799 				bits |= TIOCM_DTR;
800 		}
801 		if (msvr & CD1400_MSVR2_CTS)
802 			bits |= TIOCM_CTS;
803 		if (msvr & CD1400_MSVR2_CD)
804 			bits |= TIOCM_CD;
805 		/* Not connected on some Cyclom-Y boards? */
806 		if (msvr & CD1400_MSVR2_DSR)
807 			bits |= TIOCM_DSR;
808 		/* Not connected on some Cyclom-8Y boards? */
809 		if (msvr & CD1400_MSVR2_RI)
810 			bits |= TIOCM_RI;
811 		break;
812 
813 	case DMSET:		/* replace old values with new ones */
814 		if (cy->cy_clock == CY_CLOCK_60) {
815 			if (!ISSET(tp->t_cflag, CRTSCTS))
816 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR2,
817 				   ((bits & TIOCM_RTS) ? CD1400_MSVR2_DTR : 0));
818 			cd_write_reg(sc, cy->cy_chip, CD1400_MSVR1,
819 			    ((bits & TIOCM_DTR) ? CD1400_MSVR1_RTS : 0));
820 		} else {
821 			if (!ISSET(tp->t_cflag, CRTSCTS))
822 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR1,
823 				   ((bits & TIOCM_RTS) ? CD1400_MSVR1_RTS : 0));
824 			cd_write_reg(sc, cy->cy_chip, CD1400_MSVR2,
825 			    ((bits & TIOCM_DTR) ? CD1400_MSVR2_DTR : 0));
826 		}
827 		break;
828 
829 	case DMBIS:		/* set bits */
830 		if (cy->cy_clock == CY_CLOCK_60) {
831 			if (!ISSET(tp->t_cflag, CRTSCTS) &&
832 			    (bits & TIOCM_RTS) != 0)
833 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR2,
834 				    CD1400_MSVR2_DTR);
835 			if (bits & TIOCM_DTR)
836 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR1,
837 				    CD1400_MSVR1_RTS);
838 		} else {
839 			if (!ISSET(tp->t_cflag, CRTSCTS) &&
840 			    (bits & TIOCM_RTS) != 0)
841 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR1,
842 				    CD1400_MSVR1_RTS);
843 			if (bits & TIOCM_DTR)
844 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR2,
845 				    CD1400_MSVR2_DTR);
846 		}
847 		break;
848 
849 	case DMBIC:		/* clear bits */
850 		if (cy->cy_clock == CY_CLOCK_60) {
851 			if (!ISSET(tp->t_cflag, CRTSCTS) && (bits & TIOCM_RTS))
852 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR2, 0);
853 			if (bits & TIOCM_DTR)
854 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR1, 0);
855 		} else {
856 			if (!ISSET(tp->t_cflag, CRTSCTS) && (bits & TIOCM_RTS))
857 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR1, 0);
858 			if (bits & TIOCM_DTR)
859 				cd_write_reg(sc, cy->cy_chip, CD1400_MSVR2, 0);
860 		}
861 		break;
862 	}
863 	splx(s);
864 	return ((howto == DMGET) ? bits : 0);
865 }
866 
867 /*
868  * Upper-level handler loop (called from timer interrupt?)
869  * This routine is common for multiple cards
870  */
871 void
872 cy_poll(void *arg)
873 {
874 	int card, port;
875 	struct cy_softc *sc;
876 	struct cy_port *cy;
877 	struct tty *tp;
878 	static int counter = 0;
879 #ifdef CY_DEBUG1
880 	int did_something;
881 #endif
882 	int s = spltty();
883 
884 	if (cy_events == 0 && ++counter < 200) {
885 		splx(s);
886 		goto out;
887 	}
888 	cy_events = 0;
889 	splx(s);
890 
891 	for (card = 0; card < cy_cd.cd_ndevs; card++) {
892 		sc = device_lookup(&cy_cd, card);
893 		if (sc == NULL)
894 			continue;
895 
896 #ifdef CY_DEBUG1
897 		sc->sc_poll_count1++;
898 		did_something = 0;
899 #endif
900 
901 		for (port = 0; port < sc->sc_nchannels; port++) {
902 			cy = &sc->sc_ports[port];
903 			if ((tp = cy->cy_tty) == NULL || cy->cy_ibuf == NULL ||
904 			    (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0))
905 				continue;
906 
907 			/*
908 		         * handle received data
909 		         */
910 			while (cy->cy_ibuf_rd_ptr != cy->cy_ibuf_wr_ptr) {
911 				u_char line_stat;
912 				int chr;
913 
914 				line_stat = cy->cy_ibuf_rd_ptr[0];
915 				chr = cy->cy_ibuf_rd_ptr[1];
916 
917 				if (line_stat &
918 				    (CD1400_RDSR_BREAK | CD1400_RDSR_FE))
919 					chr |= TTY_FE;
920 				if (line_stat & CD1400_RDSR_PE)
921 					chr |= TTY_PE;
922 
923 				/*
924 				 * on an overrun error the data is treated as
925 				 * good just as it should be.
926 				 */
927 
928 #ifdef CY_DEBUG
929 				printf("%s: port %d ttyinput 0x%x\n",
930 				    sc->sc_dev.dv_xname, port, chr);
931 #endif
932 
933 				(*tp->t_linesw->l_rint) (chr, tp);
934 
935 				s = spltty();	/* really necessary? */
936 				if ((cy->cy_ibuf_rd_ptr += 2) ==
937 				    cy->cy_ibuf_end)
938 					cy->cy_ibuf_rd_ptr = cy->cy_ibuf;
939 				splx(s);
940 
941 #ifdef CY_DEBUG1
942 				did_something = 1;
943 #endif
944 			}
945 
946 			/*
947 			 * If we don't have any received data in ibuf and
948 			 * CRTSCTS is on and RTS is turned off, it is time to
949 			 * turn RTS back on
950 			 */
951 			if (ISSET(tp->t_cflag, CRTSCTS)) {
952 				/*
953 				 * we can't use cy_modem_control() here as it
954 				 * doesn't change RTS if RTSCTS is on
955 				 */
956 				cd_write_reg(sc, cy->cy_chip, CD1400_CAR,
957 				    port & CD1400_CAR_CHAN);
958 
959 				if (cy->cy_clock == CY_CLOCK_60) {
960 				  if ((cd_read_reg(sc, cy->cy_chip,
961 				    CD1400_MSVR2) & CD1400_MSVR2_DTR) == 0) {
962 					cd_write_reg(sc, cy->cy_chip,
963 					CD1400_MSVR2,CD1400_MSVR2_DTR);
964 #ifdef CY_DEBUG1
965 					did_something = 1;
966 #endif
967 				  }
968 				} else {
969 				  if ((cd_read_reg(sc, cy->cy_chip,
970 				    CD1400_MSVR1) & CD1400_MSVR1_RTS) == 0) {
971 					cd_write_reg(sc, cy->cy_chip,
972 					CD1400_MSVR1,CD1400_MSVR1_RTS);
973 #ifdef CY_DEBUG1
974 					did_something = 1;
975 #endif
976 				  }
977 				}
978 			}
979 
980 			/*
981 		         * handle carrier changes
982 		         */
983 			s = spltty();
984 			if (ISSET(cy->cy_flags, CY_F_CARRIER_CHANGED)) {
985 				int             carrier;
986 
987 				CLR(cy->cy_flags, CY_F_CARRIER_CHANGED);
988 				splx(s);
989 
990 				carrier = ((cy->cy_carrier_stat &
991 				    CD1400_MSVR2_CD) != 0);
992 
993 #ifdef CY_DEBUG
994 				printf("cy_poll: carrier change "
995 				    "(card %d, port %d, carrier %d)\n",
996 				    card, port, carrier);
997 #endif
998 				if (CY_DIALOUT(tp->t_dev) == 0 &&
999 				    !(*tp->t_linesw->l_modem)(tp, carrier))
1000 					cy_modem_control(sc, cy,
1001 					    TIOCM_DTR, DMBIC);
1002 
1003 #ifdef CY_DEBUG1
1004 				did_something = 1;
1005 #endif
1006 			} else
1007 				splx(s);
1008 
1009 			s = spltty();
1010 			if (ISSET(cy->cy_flags, CY_F_START)) {
1011 				CLR(cy->cy_flags, CY_F_START);
1012 				splx(s);
1013 
1014 				(*tp->t_linesw->l_start) (tp);
1015 
1016 #ifdef CY_DEBUG1
1017 				did_something = 1;
1018 #endif
1019 			} else
1020 				splx(s);
1021 
1022 			/* could move this to even upper level... */
1023 			if (cy->cy_fifo_overruns) {
1024 				cy->cy_fifo_overruns = 0;
1025 				/*
1026 				 * doesn't report overrun count, but
1027 				 * shouldn't really matter
1028 				 */
1029 				log(LOG_WARNING, "%s: port %d fifo overrun\n",
1030 				    sc->sc_dev.dv_xname, port);
1031 			}
1032 			if (cy->cy_ibuf_overruns) {
1033 				cy->cy_ibuf_overruns = 0;
1034 				log(LOG_WARNING, "%s: port %d ibuf overrun\n",
1035 				    sc->sc_dev.dv_xname, port);
1036 			}
1037 		}		/* for(port...) */
1038 #ifdef CY_DEBUG1
1039 		if (did_something && counter >= 200)
1040 			sc->sc_poll_count2++;
1041 #endif
1042 	} /* for(card...) */
1043 
1044 	counter = 0;
1045 
1046 out:
1047 	callout_reset(&cy_poll_callout, 1, cy_poll, NULL);
1048 }
1049 
1050 /*
1051  * hardware interrupt routine
1052  */
1053 int
1054 cy_intr(void *arg)
1055 {
1056 	struct cy_softc *sc = arg;
1057 	struct cy_port *cy;
1058 	int cy_chip, stat;
1059 	int int_serviced = 0;
1060 
1061 	/*
1062 	 * Check interrupt status of each CD1400 chip on this card
1063 	 * (multiple cards cannot share the same interrupt)
1064 	 */
1065 	for (cy_chip = 0; cy_chip < sc->sc_nchips; cy_chip++) {
1066 
1067 		stat = cd_read_reg(sc, cy_chip, CD1400_SVRR);
1068 		if (stat == 0)
1069 			continue;
1070 
1071 		if (ISSET(stat, CD1400_SVRR_RXRDY)) {
1072 			u_char save_car, save_rir, serv_type;
1073 			u_char line_stat, recv_data, n_chars;
1074 			u_char *buf_p;
1075 
1076 			save_rir = cd_read_reg(sc, cy_chip, CD1400_RIR);
1077 			save_car = cd_read_reg(sc, cy_chip, CD1400_CAR);
1078 			/* enter rx service */
1079 			cd_write_reg(sc, cy_chip, CD1400_CAR, save_rir);
1080 
1081 			serv_type = cd_read_reg(sc, cy_chip, CD1400_RIVR);
1082 			cy = &sc->sc_ports[serv_type >> 3];
1083 
1084 #ifdef CY_DEBUG1
1085 			cy->cy_rx_int_count++;
1086 #endif
1087 
1088 			buf_p = cy->cy_ibuf_wr_ptr;
1089 
1090 			if (ISSET(serv_type, CD1400_RIVR_EXCEPTION)) {
1091 				line_stat = cd_read_reg(sc, cy->cy_chip,
1092 				    CD1400_RDSR);
1093 				recv_data = cd_read_reg(sc, cy->cy_chip,
1094 				    CD1400_RDSR);
1095 
1096 				if (cy->cy_tty == NULL ||
1097 				    !ISSET(cy->cy_tty->t_state, TS_ISOPEN))
1098 					goto end_rx_serv;
1099 
1100 #ifdef CY_DEBUG
1101 				printf("%s port %d recv exception, line_stat 0x%x, char 0x%x\n",
1102 				sc->sc_dev.dv_xname, cy->cy_port_num, line_stat, recv_data);
1103 #endif
1104 				if (ISSET(line_stat, CD1400_RDSR_OE))
1105 					cy->cy_fifo_overruns++;
1106 
1107 				*buf_p++ = line_stat;
1108 				*buf_p++ = recv_data;
1109 				if (buf_p == cy->cy_ibuf_end)
1110 					buf_p = cy->cy_ibuf;
1111 
1112 				if (buf_p == cy->cy_ibuf_rd_ptr) {
1113 					if (buf_p == cy->cy_ibuf)
1114 						buf_p = cy->cy_ibuf_end;
1115 					buf_p -= 2;
1116 					cy->cy_ibuf_overruns++;
1117 				}
1118 				cy_events = 1;
1119 			} else {/* no exception, received data OK */
1120 				n_chars = cd_read_reg(sc, cy->cy_chip,
1121 				    CD1400_RDCR);
1122 
1123 				/* If no tty or not open, discard data */
1124 				if (cy->cy_tty == NULL ||
1125 				    !ISSET(cy->cy_tty->t_state, TS_ISOPEN)) {
1126 					while (n_chars--)
1127 						cd_read_reg(sc, cy->cy_chip,
1128 							    CD1400_RDSR);
1129 					goto end_rx_serv;
1130 				}
1131 
1132 #ifdef CY_DEBUG
1133 				printf("%s port %d receive ok %d chars\n",
1134 				    sc->sc_dev.dv_xname, cy->cy_port_num, n_chars);
1135 #endif
1136 				while (n_chars--) {
1137 					*buf_p++ = 0;	/* status: OK */
1138 					/* data byte */
1139 					*buf_p++ = cd_read_reg(sc,
1140 					    cy->cy_chip, CD1400_RDSR);
1141 					if (buf_p == cy->cy_ibuf_end)
1142 						buf_p = cy->cy_ibuf;
1143 					if (buf_p == cy->cy_ibuf_rd_ptr) {
1144 						if (buf_p == cy->cy_ibuf)
1145 							buf_p = cy->cy_ibuf_end;
1146 						buf_p -= 2;
1147 						cy->cy_ibuf_overruns++;
1148 						break;
1149 					}
1150 				}
1151 				cy_events = 1;
1152 			}
1153 
1154 			cy->cy_ibuf_wr_ptr = buf_p;
1155 
1156 			/* RTS handshaking for incoming data */
1157 			if (ISSET(cy->cy_tty->t_cflag, CRTSCTS)) {
1158 				int bf, msvr;
1159 
1160 				bf = buf_p - cy->cy_ibuf_rd_ptr;
1161 				if (bf < 0)
1162 					bf += CY_IBUF_SIZE;
1163 
1164 				if (bf > (CY_IBUF_SIZE / 2)) {
1165 					/* turn RTS off */
1166 					if (cy->cy_clock == CY_CLOCK_60)
1167 						msvr = CD1400_MSVR2;
1168 					else
1169 						msvr = CD1400_MSVR1;
1170 					cd_write_reg(sc, cy->cy_chip, msvr, 0);
1171 				}
1172 			}
1173 
1174 	end_rx_serv:
1175 			/* terminate service context */
1176 			cd_write_reg(sc, cy->cy_chip, CD1400_RIR,
1177 				     save_rir & 0x3f);
1178 			cd_write_reg(sc, cy->cy_chip, CD1400_CAR, save_car);
1179 			int_serviced = 1;
1180 		} /* if (rx_service...) */
1181 		if (ISSET(stat, CD1400_SVRR_MDMCH)) {
1182 			u_char save_car, save_mir, serv_type, modem_stat;
1183 
1184 			save_mir = cd_read_reg(sc, cy_chip, CD1400_MIR);
1185 			save_car = cd_read_reg(sc, cy_chip, CD1400_CAR);
1186 			/* enter modem service */
1187 			cd_write_reg(sc, cy_chip, CD1400_CAR, save_mir);
1188 
1189 			serv_type = cd_read_reg(sc, cy_chip, CD1400_MIVR);
1190 			cy = &sc->sc_ports[serv_type >> 3];
1191 
1192 #ifdef CY_DEBUG1
1193 			cy->cy_modem_int_count++;
1194 #endif
1195 
1196 			modem_stat = cd_read_reg(sc, cy->cy_chip, CD1400_MSVR2);
1197 
1198 #ifdef CY_DEBUG
1199 			printf("%s port %d modem line change, new stat 0x%x\n",
1200 			       sc->sc_dev.dv_xname, cy->cy_port_num, modem_stat);
1201 #endif
1202 			if (ISSET((cy->cy_carrier_stat ^ modem_stat), CD1400_MSVR2_CD)) {
1203 				SET(cy->cy_flags, CY_F_CARRIER_CHANGED);
1204 				cy_events = 1;
1205 			}
1206 			cy->cy_carrier_stat = modem_stat;
1207 
1208 			/* terminate service context */
1209 			cd_write_reg(sc, cy->cy_chip, CD1400_MIR, save_mir & 0x3f);
1210 			cd_write_reg(sc, cy->cy_chip, CD1400_CAR, save_car);
1211 			int_serviced = 1;
1212 		} /* if (modem_service...) */
1213 		if (ISSET(stat, CD1400_SVRR_TXRDY)) {
1214 			u_char          save_car, save_tir, serv_type,
1215 			                count, ch;
1216 			struct tty     *tp;
1217 
1218 			save_tir = cd_read_reg(sc, cy_chip, CD1400_TIR);
1219 			save_car = cd_read_reg(sc, cy_chip, CD1400_CAR);
1220 			/* enter tx service */
1221 			cd_write_reg(sc, cy_chip, CD1400_CAR, save_tir);
1222 
1223 			serv_type = cd_read_reg(sc, cy_chip, CD1400_TIVR);
1224 			cy = &sc->sc_ports[serv_type >> 3];
1225 
1226 #ifdef CY_DEBUG1
1227 			cy->cy_tx_int_count++;
1228 #endif
1229 #ifdef CY_DEBUG
1230 			printf("%s port %d tx service\n", sc->sc_dev.dv_xname,
1231 			    cy->cy_port_num);
1232 #endif
1233 
1234 			/* stop transmitting if no tty or CY_F_STOP set */
1235 			tp = cy->cy_tty;
1236 			if (tp == NULL || ISSET(cy->cy_flags, CY_F_STOP))
1237 				goto txdone;
1238 
1239 			count = 0;
1240 			if (ISSET(cy->cy_flags, CY_F_SEND_NUL)) {
1241 				cd_write_reg(sc, cy->cy_chip, CD1400_TDR, 0);
1242 				cd_write_reg(sc, cy->cy_chip, CD1400_TDR, 0);
1243 				count += 2;
1244 				CLR(cy->cy_flags, CY_F_SEND_NUL);
1245 			}
1246 			if (tp->t_outq.c_cc > 0) {
1247 				SET(tp->t_state, TS_BUSY);
1248 				while (tp->t_outq.c_cc > 0 &&
1249 				    count < CD1400_TX_FIFO_SIZE) {
1250 					ch = getc(&tp->t_outq);
1251 					/*
1252 					 * remember to double NUL characters
1253 					 * because embedded transmit commands
1254 					 * are enabled
1255 					 */
1256 					if (ch == 0) {
1257 						if (count >= CD1400_TX_FIFO_SIZE - 2) {
1258 							SET(cy->cy_flags, CY_F_SEND_NUL);
1259 							break;
1260 						}
1261 						cd_write_reg(sc, cy->cy_chip,
1262 						    CD1400_TDR, ch);
1263 						count++;
1264 					}
1265 					cd_write_reg(sc, cy->cy_chip,
1266 					    CD1400_TDR, ch);
1267 					count++;
1268 				}
1269 			} else {
1270 				/*
1271 				 * no data to send -- check if we should
1272 				 * start/stop a break
1273 				 */
1274 				/*
1275 				 * XXX does this cause too much delay before
1276 				 * breaks?
1277 				 */
1278 				if (ISSET(cy->cy_flags, CY_F_START_BREAK)) {
1279 					cd_write_reg(sc, cy->cy_chip,
1280 					    CD1400_TDR, 0);
1281 					cd_write_reg(sc, cy->cy_chip,
1282 					    CD1400_TDR, 0x81);
1283 					CLR(cy->cy_flags, CY_F_START_BREAK);
1284 				}
1285 				if (ISSET(cy->cy_flags, CY_F_END_BREAK)) {
1286 					cd_write_reg(sc, cy->cy_chip,
1287 					    CD1400_TDR, 0);
1288 					cd_write_reg(sc, cy->cy_chip,
1289 					    CD1400_TDR, 0x83);
1290 					CLR(cy->cy_flags, CY_F_END_BREAK);
1291 				}
1292 			}
1293 
1294 			if (tp->t_outq.c_cc == 0) {
1295 		txdone:
1296 				/*
1297 				 * No data to send or requested to stop.
1298 				 * Disable transmit interrupt
1299 				 */
1300 				cd_write_reg(sc, cy->cy_chip, CD1400_SRER,
1301 				     cd_read_reg(sc, cy->cy_chip, CD1400_SRER)
1302 				     & ~CD1400_SRER_TXRDY);
1303 				CLR(cy->cy_flags, CY_F_STOP);
1304 				CLR(tp->t_state, TS_BUSY);
1305 			}
1306 			if (tp->t_outq.c_cc <= tp->t_lowat) {
1307 				SET(cy->cy_flags, CY_F_START);
1308 				cy_events = 1;
1309 			}
1310 			/* terminate service context */
1311 			cd_write_reg(sc, cy->cy_chip, CD1400_TIR, save_tir & 0x3f);
1312 			cd_write_reg(sc, cy->cy_chip, CD1400_CAR, save_car);
1313 			int_serviced = 1;
1314 		}		/* if (tx_service...) */
1315 	}			/* for(...all CD1400s on a card) */
1316 
1317 	/* ensure an edge for next interrupt */
1318 	bus_space_write_1(sc->sc_memt, sc->sc_bsh,
1319 			CY_CLEAR_INTR << sc->sc_bustype, 0);
1320 	return int_serviced;
1321 }
1322 
1323 /*
1324  * subroutine to enable CD1400 transmitter
1325  */
1326 void
1327 cy_enable_transmitter(struct cy_softc *sc, struct cy_port *cy)
1328 {
1329 	int s = spltty();
1330 	cd_write_reg(sc, cy->cy_chip, CD1400_CAR,
1331 	    cy->cy_port_num & CD1400_CAR_CHAN);
1332 	cd_write_reg(sc, cy->cy_chip, CD1400_SRER,
1333 	    cd_read_reg(sc, cy->cy_chip, CD1400_SRER) | CD1400_SRER_TXRDY);
1334 	splx(s);
1335 }
1336 
1337 /*
1338  * Execute a CD1400 channel command
1339  */
1340 void
1341 cd1400_channel_cmd(struct cy_softc *sc, struct cy_port *cy, int cmd)
1342 {
1343 	u_int waitcnt = 5 * 8 * 1024;	/* approx 5 ms */
1344 
1345 #ifdef CY_DEBUG
1346 	printf("c1400_channel_cmd cy %p command 0x%x\n", cy, cmd);
1347 #endif
1348 
1349 	/* wait until cd1400 is ready to process a new command */
1350 	while (cd_read_reg(sc, cy->cy_chip, CD1400_CCR) != 0 && waitcnt-- > 0);
1351 
1352 	if (waitcnt == 0)
1353 		log(LOG_ERR, "%s: channel command timeout\n",
1354 		    sc->sc_dev.dv_xname);
1355 
1356 	cd_write_reg(sc, cy->cy_chip, CD1400_CCR, cmd);
1357 }
1358 
1359 /*
1360  * Compute clock option register and baud rate register values
1361  * for a given speed. Return 0 on success, -1 on failure.
1362  *
1363  * The error between requested and actual speed seems
1364  * to be well within allowed limits (less than 3%)
1365  * with every speed value between 50 and 150000 bps.
1366  */
1367 int
1368 cy_speed(speed_t speed, int *cor, int *bpr, int cy_clock)
1369 {
1370 	int c, co, br;
1371 
1372 	if (speed < 50 || speed > 150000)
1373 		return -1;
1374 
1375 	for (c = 0, co = 8; co <= 2048; co <<= 2, c++) {
1376 		br = (cy_clock + (co * speed) / 2) / (co * speed);
1377 		if (br < 0x100) {
1378 			*bpr = br;
1379 			*cor = c;
1380 			return 0;
1381 		}
1382 	}
1383 
1384 	return -1;
1385 }
1386