xref: /netbsd-src/sys/dev/ic/cd18xx.c (revision 6a493d6bc668897c91594964a732d38505b70cbb)
1 /*	$NetBSD: cd18xx.c,v 1.29 2012/10/27 17:18:19 chs Exp $	*/
2 
3 /*
4  * Copyright (c) 1998, 2001 Matthew R. Green
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
22  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 /*-
30  * Copyright (c) 1998, 1999 The NetBSD Foundation, Inc.
31  * All rights reserved.
32  *
33  * This code is derived from software contributed to The NetBSD Foundation
34  * by Charles M. Hannum.
35  *
36  * Redistribution and use in source and binary forms, with or without
37  * modification, are permitted provided that the following conditions
38  * are met:
39  * 1. Redistributions of source code must retain the above copyright
40  *    notice, this list of conditions and the following disclaimer.
41  * 2. Redistributions in binary form must reproduce the above copyright
42  *    notice, this list of conditions and the following disclaimer in the
43  *    documentation and/or other materials provided with the distribution.
44  *
45  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
46  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
47  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
48  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
49  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
50  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
51  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
52  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
53  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
54  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
55  * POSSIBILITY OF SUCH DAMAGE.
56  */
57 
58 /*
59  * Copyright (c) 1991 The Regents of the University of California.
60  * All rights reserved.
61  *
62  * Redistribution and use in source and binary forms, with or without
63  * modification, are permitted provided that the following conditions
64  * are met:
65  * 1. Redistributions of source code must retain the above copyright
66  *    notice, this list of conditions and the following disclaimer.
67  * 2. Redistributions in binary form must reproduce the above copyright
68  *    notice, this list of conditions and the following disclaimer in the
69  *    documentation and/or other materials provided with the distribution.
70  * 3. Neither the name of the University nor the names of its contributors
71  *    may be used to endorse or promote products derived from this software
72  *    without specific prior written permission.
73  *
74  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
75  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
76  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
77  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
78  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
79  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
80  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
81  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
82  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
83  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
84  * SUCH DAMAGE.
85  *
86  *	@(#)com.c	7.5 (Berkeley) 5/16/91
87  */
88 
89 /*
90  * cirrus logic CL-CD180/CD1864/CD1865 driver, based in (large) parts on
91  * the com and z8530 drivers.  thanks charles.
92  */
93 
94 #include <sys/cdefs.h>
95 __KERNEL_RCSID(0, "$NetBSD: cd18xx.c,v 1.29 2012/10/27 17:18:19 chs Exp $");
96 
97 #include <sys/param.h>
98 #include <sys/conf.h>
99 #include <sys/device.h>
100 #include <sys/systm.h>
101 #include <sys/malloc.h>
102 #include <sys/proc.h>
103 #include <sys/kernel.h>
104 #include <sys/tty.h>
105 #include <sys/fcntl.h>
106 #include <sys/kauth.h>
107 #include <sys/intr.h>
108 
109 #include <sys/bus.h>
110 
111 #include <dev/ic/cd18xxvar.h>
112 #include <dev/ic/cd18xxreg.h>
113 
114 #include "ioconf.h"
115 
116 /*
117  * some helpers
118  */
119 
120 static void	cdtty_attach(struct cd18xx_softc *, int);
121 
122 static inline void cd18xx_rint(struct cd18xx_softc *, int *);
123 static inline void cd18xx_tint(struct cd18xx_softc *, int *);
124 static inline void cd18xx_mint(struct cd18xx_softc *, int *);
125 
126 void cdtty_rxsoft(struct cd18xx_softc *, struct cdtty_port *, struct tty *);
127 void cdtty_txsoft(struct cd18xx_softc *, struct cdtty_port *, struct tty *);
128 void cdtty_stsoft(struct cd18xx_softc *, struct cdtty_port *, struct tty *);
129 void cd18xx_softintr(void *);
130 
131 dev_type_open(cdttyopen);
132 dev_type_close(cdttyclose);
133 dev_type_read(cdttyread);
134 dev_type_write(cdttywrite);
135 dev_type_ioctl(cdttyioctl);
136 dev_type_stop(cdttystop);
137 dev_type_tty(cdttytty);
138 dev_type_poll(cdttypoll);
139 
140 const struct cdevsw cdtty_cdevsw = {
141 	cdttyopen, cdttyclose, cdttyread, cdttywrite, cdttyioctl,
142 	cdttystop, cdttytty, cdttypoll, nommap, ttykqfilter, D_TTY
143 };
144 
145 static void	cdtty_shutdown(struct cd18xx_softc *, struct cdtty_port *);
146 static void	cdttystart(struct tty *);
147 static int	cdttyparam(struct tty *, struct termios *);
148 static void	cdtty_break(struct cd18xx_softc *, struct cdtty_port *, int);
149 static void	cdtty_modem(struct cd18xx_softc *, struct cdtty_port *, int);
150 static int	cdttyhwiflow(struct tty *, int);
151 static void	cdtty_hwiflow(struct cd18xx_softc *, struct cdtty_port *);
152 
153 static void	cdtty_loadchannelregs(struct cd18xx_softc *,
154 					   struct cdtty_port *);
155 
156 /* default read buffer size */
157 u_int cdtty_rbuf_size = CDTTY_RING_SIZE;
158 
159 /* Stop input when 3/4 of the ring is full; restart when only 1/4 is full. */
160 u_int cdtty_rbuf_hiwat = (CDTTY_RING_SIZE * 1) / 4;
161 u_int cdtty_rbuf_lowat = (CDTTY_RING_SIZE * 3) / 4;
162 
163 #define CD18XXDEBUG
164 #ifdef CD18XXDEBUG
165 #define CDD_INFO	0x0001
166 #define CDD_INTR	0x0002
167 int cd18xx_debug = CDD_INTR|CDD_INFO;
168 # define DPRINTF(l, x)	if (cd18xx_debug & l) printf x
169 #else
170 # define DPRINTF(l, x)	/* nothing */
171 #endif
172 
173 /* Known supported revisions. */
174 struct cd18xx_revs {
175 	u_char		revision;
176 	u_char		onehundred_pin;
177 	const char	*name;
178 } cd18xx_revs[] = {
179 	{ CD180_GFRCR_REV_B,		0, "CL-CD180 rev. B" },
180 	{ CD180_GFRCR_REV_C,		0, "CL-CD180 rev. C" },
181 	{ CD1864_GFRCR_REVISION_A,	1, "CL-CD1864 rev. A" },
182 	{ CD1865_GFRCR_REVISION_A,	1, "CL-CD1865 rev. A" },
183 	{ CD1865_GFRCR_REVISION_B,	1, "CL-CD1865 rev. B" },
184 	{ CD1865_GFRCR_REVISION_C,	1, "CL-CD1865 rev. C" },
185 	{ 0, 0, 0 }
186 };
187 
188 /* wait for the CCR to go to zero */
189 static inline int cd18xx_wait_ccr(struct cd18xx_softc *);
190 static inline int
191 cd18xx_wait_ccr(struct cd18xx_softc *sc)
192 {
193 	int i = 100000;
194 
195 	while (--i &&
196 	    bus_space_read_1(sc->sc_tag, sc->sc_handle, CD18xx_CCR) != 0)
197 		;
198 	return (i == 0);
199 }
200 
201 /*
202  * device attach routine, high-end portion
203  */
204 void
205 cd18xx_attach(struct cd18xx_softc *sc)
206 {
207 	static int chip_id_next = 1;
208 	int onehundred_pin, revision, i, port;
209 
210 	/* read and print the revision */
211 	revision = cd18xx_read(sc, CD18xx_GFRCR);
212 	onehundred_pin = ISSET(cd18xx_read(sc, CD18xx_SRCR),CD18xx_SRCR_PKGTYP);
213 	for (i = 0; cd18xx_revs[i].name; i++)
214 		if (revision == cd18xx_revs[i].revision ||
215 		    onehundred_pin == cd18xx_revs[i].onehundred_pin) {
216 			printf(": %s", cd18xx_revs[i].name);
217 			break;
218 		}
219 
220 	if (cd18xx_revs[i].name == NULL) {
221 		aprint_error_dev(sc->sc_dev, "unknown revision, bailing.\n");
222 		return;
223 	}
224 
225 	/* prepare for reset */
226 	cd18xx_set_car(sc, 0);
227 	cd18xx_write(sc, CD18xx_GSVR, CD18xx_GSVR_CLEAR);
228 
229 	/* wait for CCR to go to zero */
230 	if (cd18xx_wait_ccr(sc)) {
231 		printf("cd18xx_attach: reset change command timed out\n");
232 		return;
233 	}
234 
235 	/* full reset of all channels */
236 	cd18xx_write(sc, CD18xx_CCR,
237 	    CD18xx_CCR_RESET|CD18xx_CCR_RESET_HARD);
238 
239 	/* loop until the GSVR is ready */
240 	i = 100000;
241 	while (--i && cd18xx_read(sc, CD18xx_GSVR) == CD18xx_GSVR_READY)
242 		;
243 	if (i == 0) {
244 		aprint_normal("\n");
245 		aprint_error_dev(sc->sc_dev, "did not reset!\n");
246 		return;
247 	}
248 
249 	/* write the chip_id */
250 	sc->sc_chip_id = chip_id_next++;
251 #ifdef DIAGNOSTIC
252 	if (sc->sc_chip_id > 31)
253 		panic("more than 31 cd18xx's?  help.");
254 #endif
255 	cd18xx_write(sc, CD18xx_GSVR, CD18xx_GSVR_SETID(sc));
256 
257 	/* rx/tx/modem service match vectors, initalised by higher level */
258 	cd18xx_write(sc, CD18xx_MSMR, sc->sc_msmr | 0x80);
259 	cd18xx_write(sc, CD18xx_TSMR, sc->sc_tsmr | 0x80);
260 	cd18xx_write(sc, CD18xx_RSMR, sc->sc_rsmr | 0x80);
261 
262 	printf(", gsvr %x msmr %x tsmr %x rsmr %x",
263 	    cd18xx_read(sc, CD18xx_GSVR),
264 	    cd18xx_read(sc, CD18xx_MSMR),
265 	    cd18xx_read(sc, CD18xx_TSMR),
266 	    cd18xx_read(sc, CD18xx_RSMR));
267 
268 	/* prescale registers */
269 	sc->sc_pprh = 0xf0;
270 	sc->sc_pprl = 0;
271 	cd18xx_write(sc, CD18xx_PPRH, sc->sc_pprh);
272 	cd18xx_write(sc, CD18xx_PPRL, sc->sc_pprl);
273 
274 	/* establish our soft interrupt. */
275 	sc->sc_si = softint_establish(SOFTINT_SERIAL, cd18xx_softintr, sc);
276 
277 	printf(", 8 ports ready (chip id %d)\n", sc->sc_chip_id);
278 
279 	/*
280 	 * finally, we loop over all 8 channels initialising them
281 	 */
282 	for (port = 0; port < 8; port++)
283 		cdtty_attach(sc, port);
284 }
285 
286 /* tty portion of the code */
287 
288 /*
289  * tty portion attach routine
290  */
291 void
292 cdtty_attach(struct cd18xx_softc *sc, int port)
293 {
294 	struct cdtty_port *p = &sc->sc_ports[port];
295 
296 	/* load CAR with channel number */
297 	cd18xx_set_car(sc, port);
298 
299 	/* wait for CCR to go to zero */
300 	if (cd18xx_wait_ccr(sc)) {
301 		printf("cd18xx_attach: change command timed out setting "
302 		       "CAR for port %d\n", port);
303 		return;
304 	}
305 
306 	/* set the RPTR to (arbitrary) 8 */
307 	cd18xx_write(sc, CD18xx_RTPR, 8);
308 
309 	/* reset the modem signal value register */
310 	sc->sc_ports[port].p_msvr = CD18xx_MSVR_RESET;
311 
312 	/* zero the service request enable register */
313 	cd18xx_write(sc, CD18xx_SRER, 0);
314 
315 	/* enable the transmitter & receiver */
316 	SET(p->p_chanctl, CD18xx_CCR_CHANCTL |
317 		          CD18xx_CCR_CHANCTL_TxEN |
318 		          CD18xx_CCR_CHANCTL_RxEN);
319 
320 	/* XXX no console or kgdb support yet! */
321 
322 	/* get a tty structure */
323 	p->p_tty = tty_alloc();
324 	p->p_tty->t_oproc = cdttystart;
325 	p->p_tty->t_param = cdttyparam;
326 	p->p_tty->t_hwiflow = cdttyhwiflow;
327 
328 	p->p_rbuf = malloc(cdtty_rbuf_size << 1, M_DEVBUF, M_WAITOK);
329 	p->p_rbput = p->p_rbget = p->p_rbuf;
330 	p->p_rbavail = cdtty_rbuf_size;
331 	if (p->p_rbuf == NULL) {
332 		aprint_error_dev(sc->sc_dev, "unable to allocate ring buffer for tty %d\n", port);
333 		return;
334 	}
335 	p->p_ebuf = p->p_rbuf + (cdtty_rbuf_size << 1);
336 
337 	tty_attach(p->p_tty);
338 }
339 
340 /*
341  * cdtty_shutdown: called when the device is last closed.
342  */
343 void
344 cdtty_shutdown(struct cd18xx_softc *sc, struct cdtty_port *p)
345 {
346 	struct tty *tp = p->p_tty;
347 	int s;
348 
349 	s = splserial();
350 
351 	/* If we were asserting flow control, then deassert it. */
352 	SET(p->p_rx_flags, RX_IBUF_BLOCKED);
353 	cdtty_hwiflow(sc, p);
354 
355 	/* Clear any break condition set with TIOCSBRK. */
356 	cdtty_break(sc, p, 0);
357 
358 	/*
359 	 * Hang up if necessary.  Wait a bit, so the other side has time to
360 	 * notice even if we immediately open the port again.
361 	 * Avoid tsleeping above splhigh().
362 	 */
363 	if (ISSET(tp->t_cflag, HUPCL)) {
364 		cdtty_modem(sc, p, 0);
365 		splx(s);
366 		/* XXX tsleep will only timeout */
367 		(void) tsleep(sc, TTIPRI, ttclos, hz);
368 		s = splserial();
369 	}
370 
371 	/* Turn off interrupts. */
372 	p->p_srer = 0;
373 	cd18xx_write(sc, CD18xx_SRER, p->p_srer);
374 
375 	splx(s);
376 }
377 
378 /*
379  * cdttyopen:  open syscall for cdtty terminals..
380  */
381 int
382 cdttyopen(dev_t dev, int flag, int mode, struct lwp *l)
383 {
384 	struct tty *tp;
385 	struct cd18xx_softc *sc;
386 	struct cdtty_port *port;
387 	int channel, instance, s, error;
388 
389 	channel = CD18XX_CHANNEL(dev);
390 	instance = CD18XX_INSTANCE(dev);
391 
392 	/* ensure instance is valid */
393 	if (instance >= clcd_cd.cd_ndevs)
394 		return (ENXIO);
395 
396 	/* get softc and port */
397 	sc = device_lookup_private(&clcd_cd, instance);
398 	if (sc == NULL)
399 		return (ENXIO);
400 	port = &sc->sc_ports[channel];
401 	if (port == NULL || port->p_rbuf == NULL)
402 		return (ENXIO);
403 
404 	/* kgdb support?  maybe later... */
405 
406 	tp = port->p_tty;
407 
408 	if (kauth_authorize_device_tty(l->l_cred, KAUTH_DEVICE_TTY_OPEN, tp))
409 		return (EBUSY);
410 
411 	s = spltty();
412 
413 	/*
414 	 * Do the following iff this is a first open.
415 	 */
416 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
417 		struct termios t;
418 
419 		/* set up things in tp as necessary */
420 		tp->t_dev = dev;
421 
422 		/*
423 		 * Initialize the termios status to the defaults.  Add in the
424 		 * sticky bits from TIOCSFLAGS.
425 		 */
426 		t.c_ispeed = 0;
427 		t.c_ospeed = TTYDEF_SPEED;
428 		t.c_cflag = TTYDEF_CFLAG;
429 
430 		if (ISSET(port->p_swflags, TIOCFLAG_CLOCAL))
431 			SET(t.c_cflag, CLOCAL);
432 		if (ISSET(port->p_swflags, TIOCFLAG_CRTSCTS))
433 			SET(t.c_cflag, CRTSCTS);
434 		if (ISSET(port->p_swflags, TIOCFLAG_CDTRCTS))
435 			SET(t.c_cflag, CDTRCTS);
436 		if (ISSET(port->p_swflags, TIOCFLAG_MDMBUF))
437 			SET(t.c_cflag, MDMBUF);
438 
439 		/* Make sure param will see changes. */
440 		tp->t_ospeed = 0;	/* XXX set above ignored? */
441 		(void)cdttyparam(tp, &t);
442 
443 		tp->t_iflag = TTYDEF_IFLAG;
444 		tp->t_oflag = TTYDEF_OFLAG;
445 		tp->t_lflag = TTYDEF_LFLAG;
446 		ttychars(tp);
447 		ttsetwater(tp);
448 
449 		(void)splserial();
450 
451 		/* turn on rx and modem interrupts */
452 		cd18xx_set_car(sc, CD18XX_CHANNEL(dev));
453 		SET(port->p_srer, CD18xx_SRER_Rx |
454 				  CD18xx_SRER_RxSC |
455 				  CD18xx_SRER_CD);
456 		cd18xx_write(sc, CD18xx_SRER, port->p_srer);
457 
458 		/* always turn on DTR when open */
459 		cdtty_modem(sc, port, 1);
460 
461 		/* initialise ring buffer */
462 		port->p_rbget = port->p_rbput = port->p_rbuf;
463 		port->p_rbavail = cdtty_rbuf_size;
464 		CLR(port->p_rx_flags, RX_ANY_BLOCK);
465 		cdtty_hwiflow(sc, port);
466 	}
467 
468 	/* drop spl back before going into the line open */
469 	splx(s);
470 
471 	error = ttyopen(tp, CD18XX_DIALOUT(dev), ISSET(flag, O_NONBLOCK));
472 	if (error == 0)
473 		error = (*tp->t_linesw->l_open)(dev, tp);
474 
475 	return (error);
476 }
477 
478 /*
479  * cdttyclose:  close syscall for cdtty terminals..
480  */
481 int
482 cdttyclose(dev_t dev, int flag, int mode, struct lwp *l)
483 {
484 	struct cd18xx_softc *sc;
485 	struct cdtty_port *port;
486 	struct tty *tp;
487 	int channel, instance;
488 
489 	channel = CD18XX_CHANNEL(dev);
490 	instance = CD18XX_INSTANCE(dev);
491 
492 	/* ensure instance is valid */
493 	if (instance >= clcd_cd.cd_ndevs)
494 		return (ENXIO);
495 
496 	/* get softc and port */
497 	sc = device_lookup_private(&clcd_cd, instance);
498 	if (sc == NULL)
499 		return (ENXIO);
500 	port = &sc->sc_ports[channel];
501 
502 	tp = port->p_tty;
503 
504 	(*tp->t_linesw->l_close)(tp, flag);
505 	ttyclose(tp);
506 
507 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
508 		/*
509 		 * Although we got a last close, the device may still be in
510 		 * use; e.g. if this was the dialout node, and there are still
511 		 * processes waiting for carrier on the non-dialout node.
512 		 */
513 		cdtty_shutdown(sc, port);
514 	}
515 
516 	return (0);
517 }
518 
519 /*
520  * cdttyread:  read syscall for cdtty terminals..
521  */
522 int
523 cdttyread(dev_t dev, struct uio *uio, int flag)
524 {
525 	struct cd18xx_softc *sc = device_lookup_private(&clcd_cd, CD18XX_INSTANCE(dev));
526 	struct cdtty_port *port = &sc->sc_ports[CD18XX_CHANNEL(dev)];
527 	struct tty *tp = port->p_tty;
528 
529 	return ((*tp->t_linesw->l_read)(tp, uio, flag));
530 }
531 
532 /*
533  * cdttywrite:  write syscall for cdtty terminals..
534  */
535 int
536 cdttywrite(dev_t dev, struct uio *uio, int flag)
537 {
538 	struct cd18xx_softc *sc = device_lookup_private(&clcd_cd, CD18XX_INSTANCE(dev));
539 	struct cdtty_port *port = &sc->sc_ports[CD18XX_CHANNEL(dev)];
540 	struct tty *tp = port->p_tty;
541 
542 	return ((*tp->t_linesw->l_write)(tp, uio, flag));
543 }
544 
545 int
546 cdttypoll(dev_t dev, int events, struct lwp *l)
547 {
548 	struct cd18xx_softc *sc = device_lookup_private(&clcd_cd, CD18XX_INSTANCE(dev));
549 	struct cdtty_port *port = &sc->sc_ports[CD18XX_CHANNEL(dev)];
550 	struct tty *tp = port->p_tty;
551 
552 	return ((*tp->t_linesw->l_poll)(tp, events, l));
553 }
554 
555 /*
556  * cdttytty:  return a pointer to our (cdtty) tp.
557  */
558 struct tty *
559 cdttytty(dev_t dev)
560 {
561 	struct cd18xx_softc *sc = device_lookup_private(&clcd_cd, CD18XX_INSTANCE(dev));
562 	struct cdtty_port *port = &sc->sc_ports[CD18XX_CHANNEL(dev)];
563 
564 	return (port->p_tty);
565 }
566 
567 /*
568  * cdttyioctl:  ioctl syscall for cdtty terminals..
569  */
570 int
571 cdttyioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
572 {
573 	struct cd18xx_softc *sc = device_lookup_private(&clcd_cd, CD18XX_INSTANCE(dev));
574 	struct cdtty_port *port = &sc->sc_ports[CD18XX_CHANNEL(dev)];
575 	struct tty *tp = port->p_tty;
576 	int error, s;
577 
578 	error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, l);
579 	if (error != EPASSTHROUGH)
580 		return (error);
581 
582 	error = ttioctl(tp, cmd, data, flag, l);
583 	if (error != EPASSTHROUGH)
584 		return (error);
585 
586 	s = splserial();
587 
588 	switch (cmd) {
589 	case TIOCSBRK:
590 		cdtty_break(sc, port, 1);
591 		break;
592 
593 	case TIOCCBRK:
594 		cdtty_break(sc, port, 0);
595 		break;
596 
597 	case TIOCSDTR:
598 		cdtty_modem(sc, port, 1);
599 		break;
600 
601 	case TIOCCDTR:
602 		cdtty_modem(sc, port, 0);
603 		break;
604 
605 	case TIOCGFLAGS:
606 		*(int *)data = port->p_swflags;
607 		break;
608 
609 	case TIOCSFLAGS:
610 		error = kauth_authorize_device_tty(l->l_cred,
611 		    KAUTH_DEVICE_TTY_PRIVSET, tp);
612 		if (error)
613 			return (error);
614 		port->p_swflags = *(int *)data;
615 		break;
616 
617 	case TIOCMSET:
618 	case TIOCMBIS:
619 	case TIOCMBIC:
620 	case TIOCMGET:
621 	default:
622 		return (EPASSTHROUGH);
623 	}
624 
625 	splx(s);
626 	return (0);
627 }
628 
629 /*
630  * Start or restart transmission.
631  */
632 static void
633 cdttystart(struct tty *tp)
634 {
635 	struct cd18xx_softc *sc = device_lookup_private(&clcd_cd, CD18XX_INSTANCE(tp->t_dev));
636 	struct cdtty_port *p = &sc->sc_ports[CD18XX_CHANNEL(tp->t_dev)];
637 	int s;
638 
639 	s = spltty();
640 	if (ISSET(tp->t_state, TS_BUSY | TS_TIMEOUT | TS_TTSTOP))
641 		goto out;
642 	if (p->p_tx_stopped)
643 		goto out;
644 
645 	if (!ttypull(tp))
646 		goto out;
647 
648 	/* Grab the first contiguous region of buffer space. */
649 	{
650 		u_char *tba;
651 		int tbc;
652 
653 		tba = tp->t_outq.c_cf;
654 		tbc = ndqb(&tp->t_outq, 0);
655 
656 		(void)splserial();
657 
658 		p->p_tba = tba;
659 		p->p_tbc = tbc;
660 	}
661 
662 	SET(tp->t_state, TS_BUSY);
663 	p->p_tx_busy = 1;
664 
665 	/* turn on tx interrupts */
666 	if ((p->p_srer & CD18xx_SRER_Tx) == 0) {
667 		cd18xx_set_car(sc, CD18XX_CHANNEL(tp->t_dev));
668 		SET(p->p_srer, CD18xx_SRER_Tx);
669 		cd18xx_write(sc, CD18xx_SRER, p->p_srer);
670 	}
671 
672 	/*
673 	 * Now bail; we can't actually transmit bytes until we're in a
674 	 * transmit interrupt service routine.
675 	 */
676 out:
677 	splx(s);
678 	return;
679 }
680 
681 /*
682  * cdttystop:  handing ^S or other stop signals, for a cdtty
683  */
684 void
685 cdttystop(struct tty *tp, int flag)
686 {
687 	struct cd18xx_softc *sc = device_lookup_private(&clcd_cd, CD18XX_INSTANCE(tp->t_dev));
688 	struct cdtty_port *p = &sc->sc_ports[CD18XX_CHANNEL(tp->t_dev)];
689 	int s;
690 
691 	s = splserial();
692 	if (ISSET(tp->t_state, TS_BUSY)) {
693 		/* Stop transmitting at the next chunk. */
694 		p->p_tbc = 0;
695 		p->p_heldtbc = 0;
696 		if (!ISSET(tp->t_state, TS_TTSTOP))
697 			SET(tp->t_state, TS_FLUSH);
698 	}
699 	splx(s);
700 }
701 
702 /*
703  * load a channel's registers.
704  */
705 void
706 cdtty_loadchannelregs(struct cd18xx_softc *sc, struct cdtty_port *p)
707 {
708 
709 	cd18xx_set_car(sc, CD18XX_CHANNEL(p->p_tty->t_dev));
710 	cd18xx_write(sc, CD18xx_SRER, p->p_srer);
711 	cd18xx_write(sc, CD18xx_MSVR, p->p_msvr_active = p->p_msvr);
712 	cd18xx_write(sc, CD18xx_COR1, p->p_cor1);
713 	cd18xx_write(sc, CD18xx_COR2, p->p_cor2);
714 	cd18xx_write(sc, CD18xx_COR3, p->p_cor3);
715 	/*
716 	 * COR2 and COR3 change commands are not required here for
717 	 * the CL-CD1865 but we do them anyway for simplicity.
718 	 */
719 	cd18xx_write(sc, CD18xx_CCR, CD18xx_CCR_CORCHG |
720 				     CD18xx_CCR_CORCHG_COR1 |
721 				     CD18xx_CCR_CORCHG_COR2 |
722 				     CD18xx_CCR_CORCHG_COR3);
723 	cd18xx_write(sc, CD18xx_RBPRH, p->p_rbprh);
724 	cd18xx_write(sc, CD18xx_RBPRL, p->p_rbprl);
725 	cd18xx_write(sc, CD18xx_TBPRH, p->p_tbprh);
726 	cd18xx_write(sc, CD18xx_TBPRL, p->p_tbprl);
727 	if (cd18xx_wait_ccr(sc)) {
728 		DPRINTF(CDD_INFO,
729 		    ("%s: cdtty_loadchannelregs ccr wait timed out\n",
730 		    device_xname(sc->sc_dev)));
731 	}
732 	cd18xx_write(sc, CD18xx_CCR, p->p_chanctl);
733 }
734 
735 /*
736  * Set tty parameters from termios.
737  * XXX - Should just copy the whole termios after
738  * making sure all the changes could be done.
739  */
740 static int
741 cdttyparam(struct tty *tp, struct termios *t)
742 {
743 	struct cd18xx_softc *sc = device_lookup_private(&clcd_cd, CD18XX_INSTANCE(tp->t_dev));
744 	struct cdtty_port *p = &sc->sc_ports[CD18XX_CHANNEL(tp->t_dev)];
745 	int s;
746 
747 	/* Check requested parameters. */
748 	if (t->c_ospeed < 0)
749 		return (EINVAL);
750 	if (t->c_ispeed && t->c_ispeed != t->c_ospeed)
751 		return (EINVAL);
752 
753 	/*
754 	 * For the console, always force CLOCAL and !HUPCL, so that the port
755 	 * is always active.
756 	 */
757 	if (ISSET(p->p_swflags, TIOCFLAG_SOFTCAR)) {
758 		SET(t->c_cflag, CLOCAL);
759 		CLR(t->c_cflag, HUPCL);
760 	}
761 
762 	/*
763 	 * If there were no changes, don't do anything.  This avoids dropping
764 	 * input and improves performance when all we did was frob things like
765 	 * VMIN and VTIME.
766 	 */
767 	if (tp->t_ospeed == t->c_ospeed &&
768 	    tp->t_cflag == t->c_cflag)
769 		return (0);
770 
771 	/*
772 	 * Block interrupts so that state will not
773 	 * be altered until we are done setting it up.
774 	 */
775 	s = splserial();
776 
777 	/*
778 	 * Copy across the size, parity and stop bit info.
779 	 */
780 	switch (t->c_cflag & CSIZE) {
781 	case CS5:
782 		p->p_cor1 = CD18xx_COR1_CS5;
783 		break;
784 	case CS6:
785 		p->p_cor1 = CD18xx_COR1_CS6;
786 		break;
787 	case CS7:
788 		p->p_cor1 = CD18xx_COR1_CS7;
789 		break;
790 	default:
791 		p->p_cor1 = CD18xx_COR1_CS8;
792 		break;
793 	}
794 	if (ISSET(t->c_cflag, PARENB)) {
795 		SET(p->p_cor1, CD18xx_COR1_PARITY_NORMAL);
796 		if (ISSET(t->c_cflag, PARODD))
797 			SET(p->p_cor1, CD18xx_COR1_PARITY_ODD);
798 	}
799 	if (!ISSET(t->c_iflag, INPCK))
800 		SET(p->p_cor1, CD18xx_COR1_IGNORE);
801 	if (ISSET(t->c_cflag, CSTOPB))
802 		SET(p->p_cor1, CD18xx_COR1_STOPBIT_2);
803 
804 	/*
805 	 * If we're not in a mode that assumes a connection is present, then
806 	 * ignore carrier changes.
807 	 */
808 	if (ISSET(t->c_cflag, CLOCAL | MDMBUF))
809 		p->p_msvr_dcd = 0;
810 	else
811 		p->p_msvr_dcd = CD18xx_MSVR_CD;
812 
813 	/*
814 	 * Set the flow control pins depending on the current flow control
815 	 * mode.
816 	 */
817 	if (ISSET(t->c_cflag, CRTSCTS)) {
818 		p->p_mcor1_dtr = CD18xx_MCOR1_DTR;
819 		p->p_msvr_rts = CD18xx_MSVR_RTS;
820 		p->p_msvr_cts = CD18xx_MSVR_CTS;
821 		p->p_cor2 = CD18xx_COR2_RTSAOE|CD18xx_COR2_CTSAE;
822 	} else if (ISSET(t->c_cflag, MDMBUF)) {
823 		/*
824 		 * For DTR/DCD flow control, make sure we don't toggle DTR for
825 		 * carrier detection.
826 		 */
827 		p->p_mcor1_dtr = 0;
828 		p->p_msvr_rts = CD18xx_MSVR_DTR;
829 		p->p_msvr_cts = CD18xx_MSVR_CD;
830 		p->p_cor2 = 0;
831 	} else {
832 		/*
833 		 * If no flow control, then always set RTS.  This will make
834 		 * the other side happy if it mistakenly thinks we're doing
835 		 * RTS/CTS flow control.
836 		 */
837 		p->p_mcor1_dtr = CD18xx_MSVR_DTR;
838 		p->p_msvr_rts = 0;
839 		p->p_msvr_cts = 0;
840 		p->p_cor2 = 0;
841 	}
842 	p->p_msvr_mask = p->p_msvr_cts | p->p_msvr_dcd;
843 
844 	/*
845 	 * Set the FIFO threshold based on the receive speed.
846 	 *
847 	 *  * If it's a low speed, it's probably a mouse or some other
848 	 *    interactive device, so set the threshold low.
849 	 *  * If it's a high speed, trim the trigger level down to prevent
850 	 *    overflows.
851 	 *  * Otherwise set it a bit higher.
852 	 */
853 	p->p_cor3 = (t->c_ospeed <= 1200 ? 1 : t->c_ospeed <= 38400 ? 8 : 4);
854 
855 #define PORT_RATE(o, s)	\
856 	(((((o) + (s)/2) / (s)) + CD18xx_xBRPR_TPC/2) / CD18xx_xBRPR_TPC)
857 	/* Compute BPS for the requested speeds */
858 	if (t->c_ospeed) {
859 		u_int32_t tbpr = PORT_RATE(sc->sc_osc, t->c_ospeed);
860 
861 		if (tbpr == 0 || tbpr > 0xffff)
862 			return (EINVAL);
863 
864 		p->p_tbprh = tbpr >> 8;
865 		p->p_tbprl = tbpr & 0xff;
866 	}
867 
868 	if (t->c_ispeed) {
869 		u_int32_t rbpr = PORT_RATE(sc->sc_osc, t->c_ispeed);
870 
871 		if (rbpr == 0 || rbpr > 0xffff)
872 			return (EINVAL);
873 
874 		p->p_rbprh = rbpr >> 8;
875 		p->p_rbprl = rbpr & 0xff;
876 	}
877 
878 	/* And copy to tty. */
879 	tp->t_ispeed = 0;
880 	tp->t_ospeed = t->c_ospeed;
881 	tp->t_cflag = t->c_cflag;
882 
883 	if (!p->p_heldchange) {
884 		if (p->p_tx_busy) {
885 			p->p_heldtbc = p->p_tbc;
886 			p->p_tbc = 0;
887 			p->p_heldchange = 1;
888 		} else
889 			cdtty_loadchannelregs(sc, p);
890 	}
891 
892 	if (!ISSET(t->c_cflag, CHWFLOW)) {
893 		/* Disable the high water mark. */
894 		p->p_r_hiwat = 0;
895 		p->p_r_lowat = 0;
896 		if (ISSET(p->p_rx_flags, RX_TTY_OVERFLOWED)) {
897 			CLR(p->p_rx_flags, RX_TTY_OVERFLOWED);
898 			softint_schedule(sc->sc_si);
899 		}
900 		if (ISSET(p->p_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED)) {
901 			CLR(p->p_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED);
902 			cdtty_hwiflow(sc, p);
903 		}
904 	} else {
905 		p->p_r_hiwat = cdtty_rbuf_hiwat;
906 		p->p_r_lowat = cdtty_rbuf_lowat;
907 	}
908 
909 	splx(s);
910 
911 	/*
912 	 * Update the tty layer's idea of the carrier bit, in case we changed
913 	 * CLOCAL or MDMBUF.  We don't hang up here; we only do that by
914 	 * explicit request.
915 	 */
916 	(void) (*tp->t_linesw->l_modem)(tp, ISSET(p->p_msvr, CD18xx_MSVR_CD));
917 
918 	if (!ISSET(t->c_cflag, CHWFLOW)) {
919 		if (p->p_tx_stopped) {
920 			p->p_tx_stopped = 0;
921 			cdttystart(tp);
922 		}
923 	}
924 
925 	return (0);
926 }
927 
928 static void
929 cdtty_break(struct cd18xx_softc *sc, struct cdtty_port *p, int onoff)
930 {
931 
932 	/* tell tx intr handler we need a break */
933 	p->p_needbreak = !!onoff;
934 
935 	/* turn on tx interrupts if break has changed */
936 	if (p->p_needbreak != p->p_break)
937 		SET(p->p_srer, CD18xx_SRER_Tx);
938 
939 	if (!p->p_heldchange) {
940 		if (p->p_tx_busy) {
941 			p->p_heldtbc = p->p_tbc;
942 			p->p_tbc = 0;
943 			p->p_heldchange = 1;
944 		} else
945 			cdtty_loadchannelregs(sc, p);
946 	}
947 }
948 
949 /*
950  * Raise or lower modem control (DTR/RTS) signals.  If a character is
951  * in transmission, the change is deferred.
952  */
953 static void
954 cdtty_modem(struct cd18xx_softc *sc, struct cdtty_port *p, int onoff)
955 {
956 
957 	if (p->p_mcor1_dtr == 0)
958 		return;
959 
960 	if (onoff)
961 		CLR(p->p_mcor1, p->p_mcor1_dtr);
962 	else
963 		SET(p->p_mcor1, p->p_mcor1_dtr);
964 
965 	if (!p->p_heldchange) {
966 		if (p->p_tx_busy) {
967 			p->p_heldtbc = p->p_tbc;
968 			p->p_tbc = 0;
969 			p->p_heldchange = 1;
970 		} else
971 			cdtty_loadchannelregs(sc, p);
972 	}
973 }
974 
975 /*
976  * Try to block or unblock input using hardware flow-control.
977  * This is called by kern/tty.c if MDMBUF|CRTSCTS is set, and
978  * if this function returns non-zero, the TS_TBLOCK flag will
979  * be set or cleared according to the "block" arg passed.
980  */
981 int
982 cdttyhwiflow(struct tty *tp, int block)
983 {
984 	struct cd18xx_softc *sc = device_lookup_private(&clcd_cd, CD18XX_INSTANCE(tp->t_dev));
985 	struct cdtty_port *p = &sc->sc_ports[CD18XX_CHANNEL(tp->t_dev)];
986 	int s;
987 
988 	if (p->p_msvr_rts == 0)
989 		return (0);
990 
991 	s = splserial();
992 	if (block) {
993 		if (!ISSET(p->p_rx_flags, RX_TTY_BLOCKED)) {
994 			SET(p->p_rx_flags, RX_TTY_BLOCKED);
995 			cdtty_hwiflow(sc, p);
996 		}
997 	} else {
998 		if (ISSET(p->p_rx_flags, RX_TTY_OVERFLOWED)) {
999 			CLR(p->p_rx_flags, RX_TTY_OVERFLOWED);
1000 			softint_schedule(sc->sc_si);
1001 		}
1002 		if (ISSET(p->p_rx_flags, RX_TTY_BLOCKED)) {
1003 			CLR(p->p_rx_flags, RX_TTY_BLOCKED);
1004 			cdtty_hwiflow(sc, p);
1005 		}
1006 	}
1007 	splx(s);
1008 	return (1);
1009 }
1010 
1011 /*
1012  * Internal version of cdttyhwiflow, called at cdtty's priority.
1013  */
1014 static void
1015 cdtty_hwiflow(struct cd18xx_softc *sc, struct cdtty_port *p)
1016 {
1017 
1018 	if (p->p_msvr_rts == 0)
1019 		return;
1020 
1021 	if (ISSET(p->p_rx_flags, RX_ANY_BLOCK)) {
1022 		CLR(p->p_msvr, p->p_msvr_rts);
1023 		CLR(p->p_msvr_active, p->p_msvr_rts);
1024 	} else {
1025 		SET(p->p_msvr, p->p_msvr_rts);
1026 		SET(p->p_msvr_active, p->p_msvr_rts);
1027 	}
1028 	cd18xx_set_car(sc, CD18XX_CHANNEL(p->p_tty->t_dev));
1029 	cd18xx_write(sc, CD18xx_MSVR, p->p_msvr_active);
1030 }
1031 
1032 /*
1033  * indiviual interrupt routines.
1034  */
1035 
1036 /*
1037  * this is the number of interrupts allowed, total.  set it to 0
1038  * to allow unlimited interrpts
1039  */
1040 #define INTR_MAX_ALLOWED	0
1041 
1042 #if INTR_MAX_ALLOWED == 0
1043 #define GOTINTR(sc, p)	/* nothing */
1044 #else
1045 int intrcount;
1046 #define GOTINTR(sc, p)	\
1047 do { \
1048 	if (intrcount++ == INTR_MAX_ALLOWED) { \
1049 		CLR(p->p_srer, CD18xx_SRER_Tx); \
1050 		cd18xx_write(sc, CD18xx_SRER, p->p_srer); \
1051 	} \
1052 	DPRINTF(CDD_INTR, (", intrcount %d srer %x", intrcount, p->p_srer)); \
1053 } while (0)
1054 #endif
1055 
1056 /* receiver interrupt */
1057 static inline void
1058 cd18xx_rint(struct cd18xx_softc *sc, int *ns)
1059 {
1060 	struct cdtty_port *p;
1061 	u_int channel, count;
1062 	u_char *put, *end;
1063 	u_int cc;
1064 
1065 	/* work out the channel and softc */
1066 	channel = cd18xx_get_gscr1_channel(sc);
1067 	p = &sc->sc_ports[channel];
1068 	DPRINTF(CDD_INTR, ("%s: rint: channel %d", device_xname(sc->sc_dev), channel));
1069 	GOTINTR(sc, p);
1070 
1071 	end = p->p_ebuf;
1072 	put = p->p_rbput;
1073 	cc = p->p_rbavail;
1074 
1075 	/* read as many bytes as necessary */
1076 	count = cd18xx_read(sc, CD18xx_RDCR);
1077 	DPRINTF(CDD_INTR, (", %d bytes available: ", count));
1078 
1079 	while (cc > 0 && count > 0) {
1080 		u_char rcsr = cd18xx_read(sc, CD18xx_RCSR);
1081 
1082 		put[0] = cd18xx_read(sc, CD18xx_RDR);
1083 		put[1] = rcsr;
1084 
1085 		if (rcsr)
1086 			*ns = 1;
1087 
1088 		put += 2;
1089 		if (put >= end)
1090 			put = p->p_rbuf;
1091 
1092 		DPRINTF(CDD_INTR, ("."));
1093 		cc--;
1094 		count--;
1095 	}
1096 
1097 	DPRINTF(CDD_INTR, (" finished reading"));
1098 
1099 	/*
1100 	 * Current string of incoming characters ended because
1101 	 * no more data was available or we ran out of space.
1102 	 * If we're out of space, turn off receive interrupts.
1103 	 */
1104 	p->p_rbput = put;
1105 	p->p_rbavail = cc;
1106 	if (!ISSET(p->p_rx_flags, RX_TTY_OVERFLOWED)) {
1107 		p->p_rx_ready = 1;
1108 	}
1109 
1110 	/*
1111 	 * If we're out of space, disable receive interrupts
1112 	 * until the queue has drained a bit.
1113 	 */
1114 	if (!cc) {
1115 		SET(p->p_rx_flags, RX_IBUF_OVERFLOWED);
1116 		CLR(p->p_srer, CD18xx_SRER_Rx |
1117 			       CD18xx_SRER_RxSC |
1118 			       CD18xx_SRER_CD);
1119 		cd18xx_write(sc, CD18xx_SRER, p->p_srer);
1120 	}
1121 
1122 	/* finish the interrupt transaction with the IC */
1123 	cd18xx_write(sc, CD18xx_EOSRR, 0);
1124 	DPRINTF(CDD_INTR, (", done\n"));
1125 }
1126 
1127 /*
1128  * transmitter interrupt
1129  *
1130  * note this relys on the fact that we allow the transmitter FIFO to
1131  * drain completely
1132  */
1133 static inline void
1134 cd18xx_tint(struct cd18xx_softc *sc, int *ns)
1135 {
1136 	struct cdtty_port *p;
1137 	u_int channel;
1138 
1139 	/* work out the channel and softc */
1140 	channel = cd18xx_get_gscr1_channel(sc);
1141 	p = &sc->sc_ports[channel];
1142 	DPRINTF(CDD_INTR, ("%s: tint: channel %d", device_xname(sc->sc_dev),
1143 	    channel));
1144 	GOTINTR(sc, p);
1145 
1146 	/* if the current break condition is wrong, fix it */
1147 	if (p->p_break != p->p_needbreak) {
1148 		u_char buf[2];
1149 
1150 		DPRINTF(CDD_INTR, (", changing break to %d", p->p_needbreak));
1151 
1152 		/* turn on ETC processing */
1153 		cd18xx_write(sc, CD18xx_COR2, p->p_cor2 | CD18xx_COR2_ETC);
1154 
1155 		buf[0] = CD18xx_TDR_ETC_BYTE;
1156 		buf[1] = p->p_needbreak ? CD18xx_TDR_BREAK_BYTE :
1157 					    CD18xx_TDR_NOBREAK_BYTE;
1158 		cd18xx_write_multi(sc, CD18xx_TDR, buf, 2);
1159 
1160 		p->p_break = p->p_needbreak;
1161 
1162 		/* turn off ETC processing */
1163 		cd18xx_write(sc, CD18xx_COR2, p->p_cor2);
1164 	}
1165 
1166 	/*
1167 	 * If we've delayed a parameter change, do it now, and restart
1168 	 * output.
1169 	 */
1170 	if (p->p_heldchange) {
1171 		cdtty_loadchannelregs(sc, p);
1172 		p->p_heldchange = 0;
1173 		p->p_tbc = p->p_heldtbc;
1174 		p->p_heldtbc = 0;
1175 	}
1176 
1177 	/* Output the next chunk of the contiguous buffer, if any. */
1178 	if (p->p_tbc > 0) {
1179 		int n;
1180 
1181 		n = p->p_tbc;
1182 		if (n > 8) /* write up to 8 entries */
1183 			n = 8;
1184 		DPRINTF(CDD_INTR, (", writing %d bytes to TDR", n));
1185 		cd18xx_write_multi(sc, CD18xx_TDR, p->p_tba, n);
1186 		p->p_tbc -= n;
1187 		p->p_tba += n;
1188 	}
1189 
1190 	/* Disable transmit completion interrupts if we ran out of bytes. */
1191 	if (p->p_tbc == 0) {
1192 		/* Note that Tx interrupts should already be enabled */
1193 		if (ISSET(p->p_srer, CD18xx_SRER_Tx)) {
1194 			DPRINTF(CDD_INTR, (", disabling tx interrupts"));
1195 			CLR(p->p_srer, CD18xx_SRER_Tx);
1196 			cd18xx_write(sc, CD18xx_SRER, p->p_srer);
1197 		}
1198 		if (p->p_tx_busy) {
1199 			p->p_tx_busy = 0;
1200 			p->p_tx_done = 1;
1201 		}
1202 	}
1203 	*ns = 1;
1204 
1205 	/* finish the interrupt transaction with the IC */
1206 	cd18xx_write(sc, CD18xx_EOSRR, 0);
1207 	DPRINTF(CDD_INTR, (", done\n"));
1208 }
1209 
1210 /* modem signal change interrupt */
1211 static inline void
1212 cd18xx_mint(struct cd18xx_softc *sc, int *ns)
1213 {
1214 	struct cdtty_port *p;
1215 	u_int channel;
1216 	u_char msvr, delta;
1217 
1218 	/* work out the channel and softc */
1219 	channel = cd18xx_get_gscr1_channel(sc);
1220 	p = &sc->sc_ports[channel];
1221 	DPRINTF(CDD_INTR, ("%s: mint: channel %d", device_xname(sc->sc_dev), channel));
1222 	GOTINTR(sc, p);
1223 
1224 	/*
1225 	 * We ignore the MCR register, and handle detecting deltas
1226 	 * via software, like many other serial drivers.
1227 	 */
1228 	msvr = cd18xx_read(sc, CD18xx_MSVR);
1229 	delta = msvr ^ p->p_msvr;
1230 	DPRINTF(CDD_INTR, (", msvr %d", msvr));
1231 
1232 	/*
1233 	 * Process normal status changes
1234 	 */
1235 	if (ISSET(delta, p->p_msvr_mask)) {
1236 		SET(p->p_msvr_delta, delta);
1237 
1238 		DPRINTF(CDD_INTR, (", status changed delta %d", delta));
1239 		/*
1240 		 * Stop output immediately if we lose the output
1241 		 * flow control signal or carrier detect.
1242 		 */
1243 		if (ISSET(~msvr, p->p_msvr_mask)) {
1244 			p->p_tbc = 0;
1245 			p->p_heldtbc = 0;
1246 			/* Stop modem interrupt processing */
1247 		}
1248 		p->p_st_check = 1;
1249 		*ns = 1;
1250 	}
1251 
1252 	/* reset the modem signal register */
1253 	cd18xx_write(sc, CD18xx_MCR, 0);
1254 
1255 	/* finish the interrupt transaction with the IC */
1256 	cd18xx_write(sc, CD18xx_EOSRR, 0);
1257 	DPRINTF(CDD_INTR, (", done\n"));
1258 }
1259 
1260 /*
1261  * hardware interrupt routine.  call the relevant interrupt routines until
1262  * no interrupts are pending.
1263  *
1264  * note:  we do receive interrupts before all others (as we'd rather lose
1265  * a chance to transmit, than lose a character).  and we do transmit
1266  * interrupts before modem interrupts.
1267  *
1268  * we have to traverse all of the cd18xx's attached, unfortunately.
1269  */
1270 int
1271 cd18xx_hardintr(void *v)
1272 {
1273 	int i, rv = 0;
1274 	u_char ack;
1275 
1276 	DPRINTF(CDD_INTR, ("cd18xx_hardintr (ndevs %d):\n", clcd_cd.cd_ndevs));
1277 	for (i = 0; i < clcd_cd.cd_ndevs; i++)
1278 	{
1279 		struct cd18xx_softc *sc = device_lookup_private(&clcd_cd, i);
1280 		int status, ns = 0;
1281 		int count = 1;	/* process only 1 interrupts at a time for now */
1282 
1283 		if (sc == NULL)
1284 			continue;
1285 
1286 		DPRINTF(CDD_INTR, ("%s:", device_xname(sc->sc_dev)));
1287 		while (count-- &&
1288 		    (status = (cd18xx_read(sc, CD18xx_SRSR) &
1289 		     CD18xx_SRSR_PENDING))) {
1290 			rv = 1;
1291 
1292 			DPRINTF(CDD_INTR, (" status %x:", status));
1293 			if (ISSET(status, CD18xx_SRSR_RxPEND)) {
1294 				ack = (*sc->sc_ackfunc)(sc->sc_ackfunc_arg,
1295 				    CD18xx_INTRACK_RxINT);
1296 				DPRINTF(CDD_INTR, (" rx: ack1 %x\n", ack));
1297 				cd18xx_rint(sc, &ns);
1298 			}
1299 			if (ISSET(status, CD18xx_SRSR_TxPEND)) {
1300 				ack = (*sc->sc_ackfunc)(sc->sc_ackfunc_arg,
1301 				    CD18xx_INTRACK_TxINT);
1302 				DPRINTF(CDD_INTR, (" tx: ack1 %x\n", ack));
1303 				cd18xx_tint(sc, &ns);
1304 
1305 			}
1306 			if (ISSET(status, CD18xx_SRSR_MxPEND)) {
1307 				ack = (*sc->sc_ackfunc)(sc->sc_ackfunc_arg,
1308 				    CD18xx_INTRACK_MxINT);
1309 				DPRINTF(CDD_INTR, (" mx: ack1 %x\n", ack));
1310 				cd18xx_mint(sc, &ns);
1311 			}
1312 		}
1313 		if (ns)
1314 			softint_schedule(sc->sc_si);
1315 	}
1316 
1317 	return (rv);
1318 }
1319 
1320 /*
1321  * software interrupt
1322  */
1323 
1324 void
1325 cdtty_rxsoft(struct cd18xx_softc *sc, struct cdtty_port *p, struct tty *tp)
1326 {
1327 	u_char *get, *end;
1328 	u_int cc, scc;
1329 	u_char rcsr;
1330 	int code;
1331 	int s;
1332 
1333 	end = p->p_ebuf;
1334 	get = p->p_rbget;
1335 	scc = cc = cdtty_rbuf_size - p->p_rbavail;
1336 
1337 	if (cc == cdtty_rbuf_size) {
1338 		p->p_floods++;
1339 #if 0
1340 		if (p->p_errors++ == 0)
1341 			callout_reset(&p->p_diag_callout, 60 * hz,
1342 			    cdttydiag, p);
1343 #endif
1344 	}
1345 
1346 	while (cc) {
1347 		code = get[0];
1348 		rcsr = get[1];
1349 		if (ISSET(rcsr, CD18xx_RCSR_OVERRUNERR | CD18xx_RCSR_BREAK |
1350 				CD18xx_RCSR_FRAMERR | CD18xx_RCSR_PARITYERR)) {
1351 			if (ISSET(rcsr, CD18xx_RCSR_OVERRUNERR)) {
1352 				p->p_overflows++;
1353 #if 0
1354 				if (p->p_errors++ == 0)
1355 					callout_reset(&p->p_diag_callout,
1356 					    60 * hz, cdttydiag, p);
1357 #endif
1358 			}
1359 			if (ISSET(rcsr, CD18xx_RCSR_BREAK|CD18xx_RCSR_FRAMERR))
1360 				SET(code, TTY_FE);
1361 			if (ISSET(rcsr, CD18xx_RCSR_PARITYERR))
1362 				SET(code, TTY_PE);
1363 		}
1364 		if ((*tp->t_linesw->l_rint)(code, tp) == -1) {
1365 			/*
1366 			 * The line discipline's buffer is out of space.
1367 			 */
1368 			if (!ISSET(p->p_rx_flags, RX_TTY_BLOCKED)) {
1369 				/*
1370 				 * We're either not using flow control, or the
1371 				 * line discipline didn't tell us to block for
1372 				 * some reason.  Either way, we have no way to
1373 				 * know when there's more space available, so
1374 				 * just drop the rest of the data.
1375 				 */
1376 				get += cc << 1;
1377 				if (get >= end)
1378 					get -= cdtty_rbuf_size << 1;
1379 				cc = 0;
1380 			} else {
1381 				/*
1382 				 * Don't schedule any more receive processing
1383 				 * until the line discipline tells us there's
1384 				 * space available (through cdttyhwiflow()).
1385 				 * Leave the rest of the data in the input
1386 				 * buffer.
1387 				 */
1388 				SET(p->p_rx_flags, RX_TTY_OVERFLOWED);
1389 			}
1390 			break;
1391 		}
1392 		get += 2;
1393 		if (get >= end)
1394 			get = p->p_rbuf;
1395 		cc--;
1396 	}
1397 
1398 	if (cc != scc) {
1399 		p->p_rbget = get;
1400 		s = splserial();
1401 
1402 		cc = p->p_rbavail += scc - cc;
1403 		/* Buffers should be ok again, release possible block. */
1404 		if (cc >= p->p_r_lowat) {
1405 			if (ISSET(p->p_rx_flags, RX_IBUF_OVERFLOWED)) {
1406 				CLR(p->p_rx_flags, RX_IBUF_OVERFLOWED);
1407 				cd18xx_set_car(sc, CD18XX_CHANNEL(tp->t_dev));
1408 				SET(p->p_srer, CD18xx_SRER_Rx |
1409 					       CD18xx_SRER_RxSC |
1410 					       CD18xx_SRER_CD);
1411 				cd18xx_write(sc, CD18xx_SRER, p->p_srer);
1412 			}
1413 			if (ISSET(p->p_rx_flags, RX_IBUF_BLOCKED)) {
1414 				CLR(p->p_rx_flags, RX_IBUF_BLOCKED);
1415 				cdtty_hwiflow(sc, p);
1416 			}
1417 		}
1418 		splx(s);
1419 	}
1420 }
1421 
1422 void
1423 cdtty_txsoft(struct cd18xx_softc *sc, struct cdtty_port *p, struct tty *tp)
1424 {
1425 
1426 	CLR(tp->t_state, TS_BUSY);
1427 	if (ISSET(tp->t_state, TS_FLUSH))
1428 		CLR(tp->t_state, TS_FLUSH);
1429 	else
1430 		ndflush(&tp->t_outq, (int)(p->p_tba - tp->t_outq.c_cf));
1431 	(*tp->t_linesw->l_start)(tp);
1432 }
1433 
1434 void
1435 cdtty_stsoft(struct cd18xx_softc *sc, struct cdtty_port *p, struct tty *tp)
1436 {
1437 	u_char msvr, delta;
1438 	int s;
1439 
1440 	s = splserial();
1441 	msvr = p->p_msvr;
1442 	delta = p->p_msvr_delta;
1443 	p->p_msvr_delta = 0;
1444 	splx(s);
1445 
1446 	if (ISSET(delta, p->p_msvr_dcd)) {
1447 		/*
1448 		 * Inform the tty layer that carrier detect changed.
1449 		 */
1450 		(void) (*tp->t_linesw->l_modem)(tp, ISSET(msvr, CD18xx_MSVR_CD));
1451 	}
1452 
1453 	if (ISSET(delta, p->p_msvr_cts)) {
1454 		/* Block or unblock output according to flow control. */
1455 		if (ISSET(msvr, p->p_msvr_cts)) {
1456 			p->p_tx_stopped = 0;
1457 			(*tp->t_linesw->l_start)(tp);
1458 		} else {
1459 			p->p_tx_stopped = 1;
1460 		}
1461 	}
1462 }
1463 
1464 void
1465 cd18xx_softintr(void *v)
1466 {
1467 	struct cd18xx_softc *sc = v;
1468 	struct cdtty_port *p;
1469 	struct tty *tp;
1470 	int i;
1471 
1472 	for (i = 0; i < 8; i++) {
1473 		p = &sc->sc_ports[i];
1474 
1475 		tp = p->p_tty;
1476 		if (tp == NULL)
1477 			continue;
1478 		if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0)
1479 			continue;
1480 
1481 		if (p->p_rx_ready) {
1482 			p->p_rx_ready = 0;
1483 			cdtty_rxsoft(sc, p, tp);
1484 		}
1485 
1486 		if (p->p_st_check) {
1487 			p->p_st_check = 0;
1488 			cdtty_stsoft(sc, p, tp);
1489 		}
1490 
1491 		if (p->p_tx_done) {
1492 			p->p_tx_done = 0;
1493 			cdtty_txsoft(sc, p, tp);
1494 		}
1495 	}
1496 }
1497