xref: /netbsd-src/sys/dev/ic/cd18xx.c (revision b7b7574d3bf8eeb51a1fa3977b59142ec6434a55)
1 /*	$NetBSD: cd18xx.c,v 1.30 2014/03/16 05:20:27 dholland 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 1.30 2014/03/16 05:20:27 dholland 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 	.d_open = cdttyopen,
142 	.d_close = cdttyclose,
143 	.d_read = cdttyread,
144 	.d_write = cdttywrite,
145 	.d_ioctl = cdttyioctl,
146 	.d_stop = cdttystop,
147 	.d_tty = cdttytty,
148 	.d_poll = cdttypoll,
149 	.d_mmap = nommap,
150 	.d_kqfilter = ttykqfilter,
151 	.d_flag = D_TTY
152 };
153 
154 static void	cdtty_shutdown(struct cd18xx_softc *, struct cdtty_port *);
155 static void	cdttystart(struct tty *);
156 static int	cdttyparam(struct tty *, struct termios *);
157 static void	cdtty_break(struct cd18xx_softc *, struct cdtty_port *, int);
158 static void	cdtty_modem(struct cd18xx_softc *, struct cdtty_port *, int);
159 static int	cdttyhwiflow(struct tty *, int);
160 static void	cdtty_hwiflow(struct cd18xx_softc *, struct cdtty_port *);
161 
162 static void	cdtty_loadchannelregs(struct cd18xx_softc *,
163 					   struct cdtty_port *);
164 
165 /* default read buffer size */
166 u_int cdtty_rbuf_size = CDTTY_RING_SIZE;
167 
168 /* Stop input when 3/4 of the ring is full; restart when only 1/4 is full. */
169 u_int cdtty_rbuf_hiwat = (CDTTY_RING_SIZE * 1) / 4;
170 u_int cdtty_rbuf_lowat = (CDTTY_RING_SIZE * 3) / 4;
171 
172 #define CD18XXDEBUG
173 #ifdef CD18XXDEBUG
174 #define CDD_INFO	0x0001
175 #define CDD_INTR	0x0002
176 int cd18xx_debug = CDD_INTR|CDD_INFO;
177 # define DPRINTF(l, x)	if (cd18xx_debug & l) printf x
178 #else
179 # define DPRINTF(l, x)	/* nothing */
180 #endif
181 
182 /* Known supported revisions. */
183 struct cd18xx_revs {
184 	u_char		revision;
185 	u_char		onehundred_pin;
186 	const char	*name;
187 } cd18xx_revs[] = {
188 	{ CD180_GFRCR_REV_B,		0, "CL-CD180 rev. B" },
189 	{ CD180_GFRCR_REV_C,		0, "CL-CD180 rev. C" },
190 	{ CD1864_GFRCR_REVISION_A,	1, "CL-CD1864 rev. A" },
191 	{ CD1865_GFRCR_REVISION_A,	1, "CL-CD1865 rev. A" },
192 	{ CD1865_GFRCR_REVISION_B,	1, "CL-CD1865 rev. B" },
193 	{ CD1865_GFRCR_REVISION_C,	1, "CL-CD1865 rev. C" },
194 	{ 0, 0, 0 }
195 };
196 
197 /* wait for the CCR to go to zero */
198 static inline int cd18xx_wait_ccr(struct cd18xx_softc *);
199 static inline int
200 cd18xx_wait_ccr(struct cd18xx_softc *sc)
201 {
202 	int i = 100000;
203 
204 	while (--i &&
205 	    bus_space_read_1(sc->sc_tag, sc->sc_handle, CD18xx_CCR) != 0)
206 		;
207 	return (i == 0);
208 }
209 
210 /*
211  * device attach routine, high-end portion
212  */
213 void
214 cd18xx_attach(struct cd18xx_softc *sc)
215 {
216 	static int chip_id_next = 1;
217 	int onehundred_pin, revision, i, port;
218 
219 	/* read and print the revision */
220 	revision = cd18xx_read(sc, CD18xx_GFRCR);
221 	onehundred_pin = ISSET(cd18xx_read(sc, CD18xx_SRCR),CD18xx_SRCR_PKGTYP);
222 	for (i = 0; cd18xx_revs[i].name; i++)
223 		if (revision == cd18xx_revs[i].revision ||
224 		    onehundred_pin == cd18xx_revs[i].onehundred_pin) {
225 			printf(": %s", cd18xx_revs[i].name);
226 			break;
227 		}
228 
229 	if (cd18xx_revs[i].name == NULL) {
230 		aprint_error_dev(sc->sc_dev, "unknown revision, bailing.\n");
231 		return;
232 	}
233 
234 	/* prepare for reset */
235 	cd18xx_set_car(sc, 0);
236 	cd18xx_write(sc, CD18xx_GSVR, CD18xx_GSVR_CLEAR);
237 
238 	/* wait for CCR to go to zero */
239 	if (cd18xx_wait_ccr(sc)) {
240 		printf("cd18xx_attach: reset change command timed out\n");
241 		return;
242 	}
243 
244 	/* full reset of all channels */
245 	cd18xx_write(sc, CD18xx_CCR,
246 	    CD18xx_CCR_RESET|CD18xx_CCR_RESET_HARD);
247 
248 	/* loop until the GSVR is ready */
249 	i = 100000;
250 	while (--i && cd18xx_read(sc, CD18xx_GSVR) == CD18xx_GSVR_READY)
251 		;
252 	if (i == 0) {
253 		aprint_normal("\n");
254 		aprint_error_dev(sc->sc_dev, "did not reset!\n");
255 		return;
256 	}
257 
258 	/* write the chip_id */
259 	sc->sc_chip_id = chip_id_next++;
260 #ifdef DIAGNOSTIC
261 	if (sc->sc_chip_id > 31)
262 		panic("more than 31 cd18xx's?  help.");
263 #endif
264 	cd18xx_write(sc, CD18xx_GSVR, CD18xx_GSVR_SETID(sc));
265 
266 	/* rx/tx/modem service match vectors, initalised by higher level */
267 	cd18xx_write(sc, CD18xx_MSMR, sc->sc_msmr | 0x80);
268 	cd18xx_write(sc, CD18xx_TSMR, sc->sc_tsmr | 0x80);
269 	cd18xx_write(sc, CD18xx_RSMR, sc->sc_rsmr | 0x80);
270 
271 	printf(", gsvr %x msmr %x tsmr %x rsmr %x",
272 	    cd18xx_read(sc, CD18xx_GSVR),
273 	    cd18xx_read(sc, CD18xx_MSMR),
274 	    cd18xx_read(sc, CD18xx_TSMR),
275 	    cd18xx_read(sc, CD18xx_RSMR));
276 
277 	/* prescale registers */
278 	sc->sc_pprh = 0xf0;
279 	sc->sc_pprl = 0;
280 	cd18xx_write(sc, CD18xx_PPRH, sc->sc_pprh);
281 	cd18xx_write(sc, CD18xx_PPRL, sc->sc_pprl);
282 
283 	/* establish our soft interrupt. */
284 	sc->sc_si = softint_establish(SOFTINT_SERIAL, cd18xx_softintr, sc);
285 
286 	printf(", 8 ports ready (chip id %d)\n", sc->sc_chip_id);
287 
288 	/*
289 	 * finally, we loop over all 8 channels initialising them
290 	 */
291 	for (port = 0; port < 8; port++)
292 		cdtty_attach(sc, port);
293 }
294 
295 /* tty portion of the code */
296 
297 /*
298  * tty portion attach routine
299  */
300 void
301 cdtty_attach(struct cd18xx_softc *sc, int port)
302 {
303 	struct cdtty_port *p = &sc->sc_ports[port];
304 
305 	/* load CAR with channel number */
306 	cd18xx_set_car(sc, port);
307 
308 	/* wait for CCR to go to zero */
309 	if (cd18xx_wait_ccr(sc)) {
310 		printf("cd18xx_attach: change command timed out setting "
311 		       "CAR for port %d\n", port);
312 		return;
313 	}
314 
315 	/* set the RPTR to (arbitrary) 8 */
316 	cd18xx_write(sc, CD18xx_RTPR, 8);
317 
318 	/* reset the modem signal value register */
319 	sc->sc_ports[port].p_msvr = CD18xx_MSVR_RESET;
320 
321 	/* zero the service request enable register */
322 	cd18xx_write(sc, CD18xx_SRER, 0);
323 
324 	/* enable the transmitter & receiver */
325 	SET(p->p_chanctl, CD18xx_CCR_CHANCTL |
326 		          CD18xx_CCR_CHANCTL_TxEN |
327 		          CD18xx_CCR_CHANCTL_RxEN);
328 
329 	/* XXX no console or kgdb support yet! */
330 
331 	/* get a tty structure */
332 	p->p_tty = tty_alloc();
333 	p->p_tty->t_oproc = cdttystart;
334 	p->p_tty->t_param = cdttyparam;
335 	p->p_tty->t_hwiflow = cdttyhwiflow;
336 
337 	p->p_rbuf = malloc(cdtty_rbuf_size << 1, M_DEVBUF, M_WAITOK);
338 	p->p_rbput = p->p_rbget = p->p_rbuf;
339 	p->p_rbavail = cdtty_rbuf_size;
340 	if (p->p_rbuf == NULL) {
341 		aprint_error_dev(sc->sc_dev, "unable to allocate ring buffer for tty %d\n", port);
342 		return;
343 	}
344 	p->p_ebuf = p->p_rbuf + (cdtty_rbuf_size << 1);
345 
346 	tty_attach(p->p_tty);
347 }
348 
349 /*
350  * cdtty_shutdown: called when the device is last closed.
351  */
352 void
353 cdtty_shutdown(struct cd18xx_softc *sc, struct cdtty_port *p)
354 {
355 	struct tty *tp = p->p_tty;
356 	int s;
357 
358 	s = splserial();
359 
360 	/* If we were asserting flow control, then deassert it. */
361 	SET(p->p_rx_flags, RX_IBUF_BLOCKED);
362 	cdtty_hwiflow(sc, p);
363 
364 	/* Clear any break condition set with TIOCSBRK. */
365 	cdtty_break(sc, p, 0);
366 
367 	/*
368 	 * Hang up if necessary.  Wait a bit, so the other side has time to
369 	 * notice even if we immediately open the port again.
370 	 * Avoid tsleeping above splhigh().
371 	 */
372 	if (ISSET(tp->t_cflag, HUPCL)) {
373 		cdtty_modem(sc, p, 0);
374 		splx(s);
375 		/* XXX tsleep will only timeout */
376 		(void) tsleep(sc, TTIPRI, ttclos, hz);
377 		s = splserial();
378 	}
379 
380 	/* Turn off interrupts. */
381 	p->p_srer = 0;
382 	cd18xx_write(sc, CD18xx_SRER, p->p_srer);
383 
384 	splx(s);
385 }
386 
387 /*
388  * cdttyopen:  open syscall for cdtty terminals..
389  */
390 int
391 cdttyopen(dev_t dev, int flag, int mode, struct lwp *l)
392 {
393 	struct tty *tp;
394 	struct cd18xx_softc *sc;
395 	struct cdtty_port *port;
396 	int channel, instance, s, error;
397 
398 	channel = CD18XX_CHANNEL(dev);
399 	instance = CD18XX_INSTANCE(dev);
400 
401 	/* ensure instance is valid */
402 	if (instance >= clcd_cd.cd_ndevs)
403 		return (ENXIO);
404 
405 	/* get softc and port */
406 	sc = device_lookup_private(&clcd_cd, instance);
407 	if (sc == NULL)
408 		return (ENXIO);
409 	port = &sc->sc_ports[channel];
410 	if (port == NULL || port->p_rbuf == NULL)
411 		return (ENXIO);
412 
413 	/* kgdb support?  maybe later... */
414 
415 	tp = port->p_tty;
416 
417 	if (kauth_authorize_device_tty(l->l_cred, KAUTH_DEVICE_TTY_OPEN, tp))
418 		return (EBUSY);
419 
420 	s = spltty();
421 
422 	/*
423 	 * Do the following iff this is a first open.
424 	 */
425 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
426 		struct termios t;
427 
428 		/* set up things in tp as necessary */
429 		tp->t_dev = dev;
430 
431 		/*
432 		 * Initialize the termios status to the defaults.  Add in the
433 		 * sticky bits from TIOCSFLAGS.
434 		 */
435 		t.c_ispeed = 0;
436 		t.c_ospeed = TTYDEF_SPEED;
437 		t.c_cflag = TTYDEF_CFLAG;
438 
439 		if (ISSET(port->p_swflags, TIOCFLAG_CLOCAL))
440 			SET(t.c_cflag, CLOCAL);
441 		if (ISSET(port->p_swflags, TIOCFLAG_CRTSCTS))
442 			SET(t.c_cflag, CRTSCTS);
443 		if (ISSET(port->p_swflags, TIOCFLAG_CDTRCTS))
444 			SET(t.c_cflag, CDTRCTS);
445 		if (ISSET(port->p_swflags, TIOCFLAG_MDMBUF))
446 			SET(t.c_cflag, MDMBUF);
447 
448 		/* Make sure param will see changes. */
449 		tp->t_ospeed = 0;	/* XXX set above ignored? */
450 		(void)cdttyparam(tp, &t);
451 
452 		tp->t_iflag = TTYDEF_IFLAG;
453 		tp->t_oflag = TTYDEF_OFLAG;
454 		tp->t_lflag = TTYDEF_LFLAG;
455 		ttychars(tp);
456 		ttsetwater(tp);
457 
458 		(void)splserial();
459 
460 		/* turn on rx and modem interrupts */
461 		cd18xx_set_car(sc, CD18XX_CHANNEL(dev));
462 		SET(port->p_srer, CD18xx_SRER_Rx |
463 				  CD18xx_SRER_RxSC |
464 				  CD18xx_SRER_CD);
465 		cd18xx_write(sc, CD18xx_SRER, port->p_srer);
466 
467 		/* always turn on DTR when open */
468 		cdtty_modem(sc, port, 1);
469 
470 		/* initialise ring buffer */
471 		port->p_rbget = port->p_rbput = port->p_rbuf;
472 		port->p_rbavail = cdtty_rbuf_size;
473 		CLR(port->p_rx_flags, RX_ANY_BLOCK);
474 		cdtty_hwiflow(sc, port);
475 	}
476 
477 	/* drop spl back before going into the line open */
478 	splx(s);
479 
480 	error = ttyopen(tp, CD18XX_DIALOUT(dev), ISSET(flag, O_NONBLOCK));
481 	if (error == 0)
482 		error = (*tp->t_linesw->l_open)(dev, tp);
483 
484 	return (error);
485 }
486 
487 /*
488  * cdttyclose:  close syscall for cdtty terminals..
489  */
490 int
491 cdttyclose(dev_t dev, int flag, int mode, struct lwp *l)
492 {
493 	struct cd18xx_softc *sc;
494 	struct cdtty_port *port;
495 	struct tty *tp;
496 	int channel, instance;
497 
498 	channel = CD18XX_CHANNEL(dev);
499 	instance = CD18XX_INSTANCE(dev);
500 
501 	/* ensure instance is valid */
502 	if (instance >= clcd_cd.cd_ndevs)
503 		return (ENXIO);
504 
505 	/* get softc and port */
506 	sc = device_lookup_private(&clcd_cd, instance);
507 	if (sc == NULL)
508 		return (ENXIO);
509 	port = &sc->sc_ports[channel];
510 
511 	tp = port->p_tty;
512 
513 	(*tp->t_linesw->l_close)(tp, flag);
514 	ttyclose(tp);
515 
516 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
517 		/*
518 		 * Although we got a last close, the device may still be in
519 		 * use; e.g. if this was the dialout node, and there are still
520 		 * processes waiting for carrier on the non-dialout node.
521 		 */
522 		cdtty_shutdown(sc, port);
523 	}
524 
525 	return (0);
526 }
527 
528 /*
529  * cdttyread:  read syscall for cdtty terminals..
530  */
531 int
532 cdttyread(dev_t dev, struct uio *uio, int flag)
533 {
534 	struct cd18xx_softc *sc = device_lookup_private(&clcd_cd, CD18XX_INSTANCE(dev));
535 	struct cdtty_port *port = &sc->sc_ports[CD18XX_CHANNEL(dev)];
536 	struct tty *tp = port->p_tty;
537 
538 	return ((*tp->t_linesw->l_read)(tp, uio, flag));
539 }
540 
541 /*
542  * cdttywrite:  write syscall for cdtty terminals..
543  */
544 int
545 cdttywrite(dev_t dev, struct uio *uio, int flag)
546 {
547 	struct cd18xx_softc *sc = device_lookup_private(&clcd_cd, CD18XX_INSTANCE(dev));
548 	struct cdtty_port *port = &sc->sc_ports[CD18XX_CHANNEL(dev)];
549 	struct tty *tp = port->p_tty;
550 
551 	return ((*tp->t_linesw->l_write)(tp, uio, flag));
552 }
553 
554 int
555 cdttypoll(dev_t dev, int events, struct lwp *l)
556 {
557 	struct cd18xx_softc *sc = device_lookup_private(&clcd_cd, CD18XX_INSTANCE(dev));
558 	struct cdtty_port *port = &sc->sc_ports[CD18XX_CHANNEL(dev)];
559 	struct tty *tp = port->p_tty;
560 
561 	return ((*tp->t_linesw->l_poll)(tp, events, l));
562 }
563 
564 /*
565  * cdttytty:  return a pointer to our (cdtty) tp.
566  */
567 struct tty *
568 cdttytty(dev_t dev)
569 {
570 	struct cd18xx_softc *sc = device_lookup_private(&clcd_cd, CD18XX_INSTANCE(dev));
571 	struct cdtty_port *port = &sc->sc_ports[CD18XX_CHANNEL(dev)];
572 
573 	return (port->p_tty);
574 }
575 
576 /*
577  * cdttyioctl:  ioctl syscall for cdtty terminals..
578  */
579 int
580 cdttyioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
581 {
582 	struct cd18xx_softc *sc = device_lookup_private(&clcd_cd, CD18XX_INSTANCE(dev));
583 	struct cdtty_port *port = &sc->sc_ports[CD18XX_CHANNEL(dev)];
584 	struct tty *tp = port->p_tty;
585 	int error, s;
586 
587 	error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, l);
588 	if (error != EPASSTHROUGH)
589 		return (error);
590 
591 	error = ttioctl(tp, cmd, data, flag, l);
592 	if (error != EPASSTHROUGH)
593 		return (error);
594 
595 	s = splserial();
596 
597 	switch (cmd) {
598 	case TIOCSBRK:
599 		cdtty_break(sc, port, 1);
600 		break;
601 
602 	case TIOCCBRK:
603 		cdtty_break(sc, port, 0);
604 		break;
605 
606 	case TIOCSDTR:
607 		cdtty_modem(sc, port, 1);
608 		break;
609 
610 	case TIOCCDTR:
611 		cdtty_modem(sc, port, 0);
612 		break;
613 
614 	case TIOCGFLAGS:
615 		*(int *)data = port->p_swflags;
616 		break;
617 
618 	case TIOCSFLAGS:
619 		error = kauth_authorize_device_tty(l->l_cred,
620 		    KAUTH_DEVICE_TTY_PRIVSET, tp);
621 		if (error)
622 			return (error);
623 		port->p_swflags = *(int *)data;
624 		break;
625 
626 	case TIOCMSET:
627 	case TIOCMBIS:
628 	case TIOCMBIC:
629 	case TIOCMGET:
630 	default:
631 		return (EPASSTHROUGH);
632 	}
633 
634 	splx(s);
635 	return (0);
636 }
637 
638 /*
639  * Start or restart transmission.
640  */
641 static void
642 cdttystart(struct tty *tp)
643 {
644 	struct cd18xx_softc *sc = device_lookup_private(&clcd_cd, CD18XX_INSTANCE(tp->t_dev));
645 	struct cdtty_port *p = &sc->sc_ports[CD18XX_CHANNEL(tp->t_dev)];
646 	int s;
647 
648 	s = spltty();
649 	if (ISSET(tp->t_state, TS_BUSY | TS_TIMEOUT | TS_TTSTOP))
650 		goto out;
651 	if (p->p_tx_stopped)
652 		goto out;
653 
654 	if (!ttypull(tp))
655 		goto out;
656 
657 	/* Grab the first contiguous region of buffer space. */
658 	{
659 		u_char *tba;
660 		int tbc;
661 
662 		tba = tp->t_outq.c_cf;
663 		tbc = ndqb(&tp->t_outq, 0);
664 
665 		(void)splserial();
666 
667 		p->p_tba = tba;
668 		p->p_tbc = tbc;
669 	}
670 
671 	SET(tp->t_state, TS_BUSY);
672 	p->p_tx_busy = 1;
673 
674 	/* turn on tx interrupts */
675 	if ((p->p_srer & CD18xx_SRER_Tx) == 0) {
676 		cd18xx_set_car(sc, CD18XX_CHANNEL(tp->t_dev));
677 		SET(p->p_srer, CD18xx_SRER_Tx);
678 		cd18xx_write(sc, CD18xx_SRER, p->p_srer);
679 	}
680 
681 	/*
682 	 * Now bail; we can't actually transmit bytes until we're in a
683 	 * transmit interrupt service routine.
684 	 */
685 out:
686 	splx(s);
687 	return;
688 }
689 
690 /*
691  * cdttystop:  handing ^S or other stop signals, for a cdtty
692  */
693 void
694 cdttystop(struct tty *tp, int flag)
695 {
696 	struct cd18xx_softc *sc = device_lookup_private(&clcd_cd, CD18XX_INSTANCE(tp->t_dev));
697 	struct cdtty_port *p = &sc->sc_ports[CD18XX_CHANNEL(tp->t_dev)];
698 	int s;
699 
700 	s = splserial();
701 	if (ISSET(tp->t_state, TS_BUSY)) {
702 		/* Stop transmitting at the next chunk. */
703 		p->p_tbc = 0;
704 		p->p_heldtbc = 0;
705 		if (!ISSET(tp->t_state, TS_TTSTOP))
706 			SET(tp->t_state, TS_FLUSH);
707 	}
708 	splx(s);
709 }
710 
711 /*
712  * load a channel's registers.
713  */
714 void
715 cdtty_loadchannelregs(struct cd18xx_softc *sc, struct cdtty_port *p)
716 {
717 
718 	cd18xx_set_car(sc, CD18XX_CHANNEL(p->p_tty->t_dev));
719 	cd18xx_write(sc, CD18xx_SRER, p->p_srer);
720 	cd18xx_write(sc, CD18xx_MSVR, p->p_msvr_active = p->p_msvr);
721 	cd18xx_write(sc, CD18xx_COR1, p->p_cor1);
722 	cd18xx_write(sc, CD18xx_COR2, p->p_cor2);
723 	cd18xx_write(sc, CD18xx_COR3, p->p_cor3);
724 	/*
725 	 * COR2 and COR3 change commands are not required here for
726 	 * the CL-CD1865 but we do them anyway for simplicity.
727 	 */
728 	cd18xx_write(sc, CD18xx_CCR, CD18xx_CCR_CORCHG |
729 				     CD18xx_CCR_CORCHG_COR1 |
730 				     CD18xx_CCR_CORCHG_COR2 |
731 				     CD18xx_CCR_CORCHG_COR3);
732 	cd18xx_write(sc, CD18xx_RBPRH, p->p_rbprh);
733 	cd18xx_write(sc, CD18xx_RBPRL, p->p_rbprl);
734 	cd18xx_write(sc, CD18xx_TBPRH, p->p_tbprh);
735 	cd18xx_write(sc, CD18xx_TBPRL, p->p_tbprl);
736 	if (cd18xx_wait_ccr(sc)) {
737 		DPRINTF(CDD_INFO,
738 		    ("%s: cdtty_loadchannelregs ccr wait timed out\n",
739 		    device_xname(sc->sc_dev)));
740 	}
741 	cd18xx_write(sc, CD18xx_CCR, p->p_chanctl);
742 }
743 
744 /*
745  * Set tty parameters from termios.
746  * XXX - Should just copy the whole termios after
747  * making sure all the changes could be done.
748  */
749 static int
750 cdttyparam(struct tty *tp, struct termios *t)
751 {
752 	struct cd18xx_softc *sc = device_lookup_private(&clcd_cd, CD18XX_INSTANCE(tp->t_dev));
753 	struct cdtty_port *p = &sc->sc_ports[CD18XX_CHANNEL(tp->t_dev)];
754 	int s;
755 
756 	/* Check requested parameters. */
757 	if (t->c_ospeed < 0)
758 		return (EINVAL);
759 	if (t->c_ispeed && t->c_ispeed != t->c_ospeed)
760 		return (EINVAL);
761 
762 	/*
763 	 * For the console, always force CLOCAL and !HUPCL, so that the port
764 	 * is always active.
765 	 */
766 	if (ISSET(p->p_swflags, TIOCFLAG_SOFTCAR)) {
767 		SET(t->c_cflag, CLOCAL);
768 		CLR(t->c_cflag, HUPCL);
769 	}
770 
771 	/*
772 	 * If there were no changes, don't do anything.  This avoids dropping
773 	 * input and improves performance when all we did was frob things like
774 	 * VMIN and VTIME.
775 	 */
776 	if (tp->t_ospeed == t->c_ospeed &&
777 	    tp->t_cflag == t->c_cflag)
778 		return (0);
779 
780 	/*
781 	 * Block interrupts so that state will not
782 	 * be altered until we are done setting it up.
783 	 */
784 	s = splserial();
785 
786 	/*
787 	 * Copy across the size, parity and stop bit info.
788 	 */
789 	switch (t->c_cflag & CSIZE) {
790 	case CS5:
791 		p->p_cor1 = CD18xx_COR1_CS5;
792 		break;
793 	case CS6:
794 		p->p_cor1 = CD18xx_COR1_CS6;
795 		break;
796 	case CS7:
797 		p->p_cor1 = CD18xx_COR1_CS7;
798 		break;
799 	default:
800 		p->p_cor1 = CD18xx_COR1_CS8;
801 		break;
802 	}
803 	if (ISSET(t->c_cflag, PARENB)) {
804 		SET(p->p_cor1, CD18xx_COR1_PARITY_NORMAL);
805 		if (ISSET(t->c_cflag, PARODD))
806 			SET(p->p_cor1, CD18xx_COR1_PARITY_ODD);
807 	}
808 	if (!ISSET(t->c_iflag, INPCK))
809 		SET(p->p_cor1, CD18xx_COR1_IGNORE);
810 	if (ISSET(t->c_cflag, CSTOPB))
811 		SET(p->p_cor1, CD18xx_COR1_STOPBIT_2);
812 
813 	/*
814 	 * If we're not in a mode that assumes a connection is present, then
815 	 * ignore carrier changes.
816 	 */
817 	if (ISSET(t->c_cflag, CLOCAL | MDMBUF))
818 		p->p_msvr_dcd = 0;
819 	else
820 		p->p_msvr_dcd = CD18xx_MSVR_CD;
821 
822 	/*
823 	 * Set the flow control pins depending on the current flow control
824 	 * mode.
825 	 */
826 	if (ISSET(t->c_cflag, CRTSCTS)) {
827 		p->p_mcor1_dtr = CD18xx_MCOR1_DTR;
828 		p->p_msvr_rts = CD18xx_MSVR_RTS;
829 		p->p_msvr_cts = CD18xx_MSVR_CTS;
830 		p->p_cor2 = CD18xx_COR2_RTSAOE|CD18xx_COR2_CTSAE;
831 	} else if (ISSET(t->c_cflag, MDMBUF)) {
832 		/*
833 		 * For DTR/DCD flow control, make sure we don't toggle DTR for
834 		 * carrier detection.
835 		 */
836 		p->p_mcor1_dtr = 0;
837 		p->p_msvr_rts = CD18xx_MSVR_DTR;
838 		p->p_msvr_cts = CD18xx_MSVR_CD;
839 		p->p_cor2 = 0;
840 	} else {
841 		/*
842 		 * If no flow control, then always set RTS.  This will make
843 		 * the other side happy if it mistakenly thinks we're doing
844 		 * RTS/CTS flow control.
845 		 */
846 		p->p_mcor1_dtr = CD18xx_MSVR_DTR;
847 		p->p_msvr_rts = 0;
848 		p->p_msvr_cts = 0;
849 		p->p_cor2 = 0;
850 	}
851 	p->p_msvr_mask = p->p_msvr_cts | p->p_msvr_dcd;
852 
853 	/*
854 	 * Set the FIFO threshold based on the receive speed.
855 	 *
856 	 *  * If it's a low speed, it's probably a mouse or some other
857 	 *    interactive device, so set the threshold low.
858 	 *  * If it's a high speed, trim the trigger level down to prevent
859 	 *    overflows.
860 	 *  * Otherwise set it a bit higher.
861 	 */
862 	p->p_cor3 = (t->c_ospeed <= 1200 ? 1 : t->c_ospeed <= 38400 ? 8 : 4);
863 
864 #define PORT_RATE(o, s)	\
865 	(((((o) + (s)/2) / (s)) + CD18xx_xBRPR_TPC/2) / CD18xx_xBRPR_TPC)
866 	/* Compute BPS for the requested speeds */
867 	if (t->c_ospeed) {
868 		u_int32_t tbpr = PORT_RATE(sc->sc_osc, t->c_ospeed);
869 
870 		if (tbpr == 0 || tbpr > 0xffff)
871 			return (EINVAL);
872 
873 		p->p_tbprh = tbpr >> 8;
874 		p->p_tbprl = tbpr & 0xff;
875 	}
876 
877 	if (t->c_ispeed) {
878 		u_int32_t rbpr = PORT_RATE(sc->sc_osc, t->c_ispeed);
879 
880 		if (rbpr == 0 || rbpr > 0xffff)
881 			return (EINVAL);
882 
883 		p->p_rbprh = rbpr >> 8;
884 		p->p_rbprl = rbpr & 0xff;
885 	}
886 
887 	/* And copy to tty. */
888 	tp->t_ispeed = 0;
889 	tp->t_ospeed = t->c_ospeed;
890 	tp->t_cflag = t->c_cflag;
891 
892 	if (!p->p_heldchange) {
893 		if (p->p_tx_busy) {
894 			p->p_heldtbc = p->p_tbc;
895 			p->p_tbc = 0;
896 			p->p_heldchange = 1;
897 		} else
898 			cdtty_loadchannelregs(sc, p);
899 	}
900 
901 	if (!ISSET(t->c_cflag, CHWFLOW)) {
902 		/* Disable the high water mark. */
903 		p->p_r_hiwat = 0;
904 		p->p_r_lowat = 0;
905 		if (ISSET(p->p_rx_flags, RX_TTY_OVERFLOWED)) {
906 			CLR(p->p_rx_flags, RX_TTY_OVERFLOWED);
907 			softint_schedule(sc->sc_si);
908 		}
909 		if (ISSET(p->p_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED)) {
910 			CLR(p->p_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED);
911 			cdtty_hwiflow(sc, p);
912 		}
913 	} else {
914 		p->p_r_hiwat = cdtty_rbuf_hiwat;
915 		p->p_r_lowat = cdtty_rbuf_lowat;
916 	}
917 
918 	splx(s);
919 
920 	/*
921 	 * Update the tty layer's idea of the carrier bit, in case we changed
922 	 * CLOCAL or MDMBUF.  We don't hang up here; we only do that by
923 	 * explicit request.
924 	 */
925 	(void) (*tp->t_linesw->l_modem)(tp, ISSET(p->p_msvr, CD18xx_MSVR_CD));
926 
927 	if (!ISSET(t->c_cflag, CHWFLOW)) {
928 		if (p->p_tx_stopped) {
929 			p->p_tx_stopped = 0;
930 			cdttystart(tp);
931 		}
932 	}
933 
934 	return (0);
935 }
936 
937 static void
938 cdtty_break(struct cd18xx_softc *sc, struct cdtty_port *p, int onoff)
939 {
940 
941 	/* tell tx intr handler we need a break */
942 	p->p_needbreak = !!onoff;
943 
944 	/* turn on tx interrupts if break has changed */
945 	if (p->p_needbreak != p->p_break)
946 		SET(p->p_srer, CD18xx_SRER_Tx);
947 
948 	if (!p->p_heldchange) {
949 		if (p->p_tx_busy) {
950 			p->p_heldtbc = p->p_tbc;
951 			p->p_tbc = 0;
952 			p->p_heldchange = 1;
953 		} else
954 			cdtty_loadchannelregs(sc, p);
955 	}
956 }
957 
958 /*
959  * Raise or lower modem control (DTR/RTS) signals.  If a character is
960  * in transmission, the change is deferred.
961  */
962 static void
963 cdtty_modem(struct cd18xx_softc *sc, struct cdtty_port *p, int onoff)
964 {
965 
966 	if (p->p_mcor1_dtr == 0)
967 		return;
968 
969 	if (onoff)
970 		CLR(p->p_mcor1, p->p_mcor1_dtr);
971 	else
972 		SET(p->p_mcor1, p->p_mcor1_dtr);
973 
974 	if (!p->p_heldchange) {
975 		if (p->p_tx_busy) {
976 			p->p_heldtbc = p->p_tbc;
977 			p->p_tbc = 0;
978 			p->p_heldchange = 1;
979 		} else
980 			cdtty_loadchannelregs(sc, p);
981 	}
982 }
983 
984 /*
985  * Try to block or unblock input using hardware flow-control.
986  * This is called by kern/tty.c if MDMBUF|CRTSCTS is set, and
987  * if this function returns non-zero, the TS_TBLOCK flag will
988  * be set or cleared according to the "block" arg passed.
989  */
990 int
991 cdttyhwiflow(struct tty *tp, int block)
992 {
993 	struct cd18xx_softc *sc = device_lookup_private(&clcd_cd, CD18XX_INSTANCE(tp->t_dev));
994 	struct cdtty_port *p = &sc->sc_ports[CD18XX_CHANNEL(tp->t_dev)];
995 	int s;
996 
997 	if (p->p_msvr_rts == 0)
998 		return (0);
999 
1000 	s = splserial();
1001 	if (block) {
1002 		if (!ISSET(p->p_rx_flags, RX_TTY_BLOCKED)) {
1003 			SET(p->p_rx_flags, RX_TTY_BLOCKED);
1004 			cdtty_hwiflow(sc, p);
1005 		}
1006 	} else {
1007 		if (ISSET(p->p_rx_flags, RX_TTY_OVERFLOWED)) {
1008 			CLR(p->p_rx_flags, RX_TTY_OVERFLOWED);
1009 			softint_schedule(sc->sc_si);
1010 		}
1011 		if (ISSET(p->p_rx_flags, RX_TTY_BLOCKED)) {
1012 			CLR(p->p_rx_flags, RX_TTY_BLOCKED);
1013 			cdtty_hwiflow(sc, p);
1014 		}
1015 	}
1016 	splx(s);
1017 	return (1);
1018 }
1019 
1020 /*
1021  * Internal version of cdttyhwiflow, called at cdtty's priority.
1022  */
1023 static void
1024 cdtty_hwiflow(struct cd18xx_softc *sc, struct cdtty_port *p)
1025 {
1026 
1027 	if (p->p_msvr_rts == 0)
1028 		return;
1029 
1030 	if (ISSET(p->p_rx_flags, RX_ANY_BLOCK)) {
1031 		CLR(p->p_msvr, p->p_msvr_rts);
1032 		CLR(p->p_msvr_active, p->p_msvr_rts);
1033 	} else {
1034 		SET(p->p_msvr, p->p_msvr_rts);
1035 		SET(p->p_msvr_active, p->p_msvr_rts);
1036 	}
1037 	cd18xx_set_car(sc, CD18XX_CHANNEL(p->p_tty->t_dev));
1038 	cd18xx_write(sc, CD18xx_MSVR, p->p_msvr_active);
1039 }
1040 
1041 /*
1042  * indiviual interrupt routines.
1043  */
1044 
1045 /*
1046  * this is the number of interrupts allowed, total.  set it to 0
1047  * to allow unlimited interrpts
1048  */
1049 #define INTR_MAX_ALLOWED	0
1050 
1051 #if INTR_MAX_ALLOWED == 0
1052 #define GOTINTR(sc, p)	/* nothing */
1053 #else
1054 int intrcount;
1055 #define GOTINTR(sc, p)	\
1056 do { \
1057 	if (intrcount++ == INTR_MAX_ALLOWED) { \
1058 		CLR(p->p_srer, CD18xx_SRER_Tx); \
1059 		cd18xx_write(sc, CD18xx_SRER, p->p_srer); \
1060 	} \
1061 	DPRINTF(CDD_INTR, (", intrcount %d srer %x", intrcount, p->p_srer)); \
1062 } while (0)
1063 #endif
1064 
1065 /* receiver interrupt */
1066 static inline void
1067 cd18xx_rint(struct cd18xx_softc *sc, int *ns)
1068 {
1069 	struct cdtty_port *p;
1070 	u_int channel, count;
1071 	u_char *put, *end;
1072 	u_int cc;
1073 
1074 	/* work out the channel and softc */
1075 	channel = cd18xx_get_gscr1_channel(sc);
1076 	p = &sc->sc_ports[channel];
1077 	DPRINTF(CDD_INTR, ("%s: rint: channel %d", device_xname(sc->sc_dev), channel));
1078 	GOTINTR(sc, p);
1079 
1080 	end = p->p_ebuf;
1081 	put = p->p_rbput;
1082 	cc = p->p_rbavail;
1083 
1084 	/* read as many bytes as necessary */
1085 	count = cd18xx_read(sc, CD18xx_RDCR);
1086 	DPRINTF(CDD_INTR, (", %d bytes available: ", count));
1087 
1088 	while (cc > 0 && count > 0) {
1089 		u_char rcsr = cd18xx_read(sc, CD18xx_RCSR);
1090 
1091 		put[0] = cd18xx_read(sc, CD18xx_RDR);
1092 		put[1] = rcsr;
1093 
1094 		if (rcsr)
1095 			*ns = 1;
1096 
1097 		put += 2;
1098 		if (put >= end)
1099 			put = p->p_rbuf;
1100 
1101 		DPRINTF(CDD_INTR, ("."));
1102 		cc--;
1103 		count--;
1104 	}
1105 
1106 	DPRINTF(CDD_INTR, (" finished reading"));
1107 
1108 	/*
1109 	 * Current string of incoming characters ended because
1110 	 * no more data was available or we ran out of space.
1111 	 * If we're out of space, turn off receive interrupts.
1112 	 */
1113 	p->p_rbput = put;
1114 	p->p_rbavail = cc;
1115 	if (!ISSET(p->p_rx_flags, RX_TTY_OVERFLOWED)) {
1116 		p->p_rx_ready = 1;
1117 	}
1118 
1119 	/*
1120 	 * If we're out of space, disable receive interrupts
1121 	 * until the queue has drained a bit.
1122 	 */
1123 	if (!cc) {
1124 		SET(p->p_rx_flags, RX_IBUF_OVERFLOWED);
1125 		CLR(p->p_srer, CD18xx_SRER_Rx |
1126 			       CD18xx_SRER_RxSC |
1127 			       CD18xx_SRER_CD);
1128 		cd18xx_write(sc, CD18xx_SRER, p->p_srer);
1129 	}
1130 
1131 	/* finish the interrupt transaction with the IC */
1132 	cd18xx_write(sc, CD18xx_EOSRR, 0);
1133 	DPRINTF(CDD_INTR, (", done\n"));
1134 }
1135 
1136 /*
1137  * transmitter interrupt
1138  *
1139  * note this relys on the fact that we allow the transmitter FIFO to
1140  * drain completely
1141  */
1142 static inline void
1143 cd18xx_tint(struct cd18xx_softc *sc, int *ns)
1144 {
1145 	struct cdtty_port *p;
1146 	u_int channel;
1147 
1148 	/* work out the channel and softc */
1149 	channel = cd18xx_get_gscr1_channel(sc);
1150 	p = &sc->sc_ports[channel];
1151 	DPRINTF(CDD_INTR, ("%s: tint: channel %d", device_xname(sc->sc_dev),
1152 	    channel));
1153 	GOTINTR(sc, p);
1154 
1155 	/* if the current break condition is wrong, fix it */
1156 	if (p->p_break != p->p_needbreak) {
1157 		u_char buf[2];
1158 
1159 		DPRINTF(CDD_INTR, (", changing break to %d", p->p_needbreak));
1160 
1161 		/* turn on ETC processing */
1162 		cd18xx_write(sc, CD18xx_COR2, p->p_cor2 | CD18xx_COR2_ETC);
1163 
1164 		buf[0] = CD18xx_TDR_ETC_BYTE;
1165 		buf[1] = p->p_needbreak ? CD18xx_TDR_BREAK_BYTE :
1166 					    CD18xx_TDR_NOBREAK_BYTE;
1167 		cd18xx_write_multi(sc, CD18xx_TDR, buf, 2);
1168 
1169 		p->p_break = p->p_needbreak;
1170 
1171 		/* turn off ETC processing */
1172 		cd18xx_write(sc, CD18xx_COR2, p->p_cor2);
1173 	}
1174 
1175 	/*
1176 	 * If we've delayed a parameter change, do it now, and restart
1177 	 * output.
1178 	 */
1179 	if (p->p_heldchange) {
1180 		cdtty_loadchannelregs(sc, p);
1181 		p->p_heldchange = 0;
1182 		p->p_tbc = p->p_heldtbc;
1183 		p->p_heldtbc = 0;
1184 	}
1185 
1186 	/* Output the next chunk of the contiguous buffer, if any. */
1187 	if (p->p_tbc > 0) {
1188 		int n;
1189 
1190 		n = p->p_tbc;
1191 		if (n > 8) /* write up to 8 entries */
1192 			n = 8;
1193 		DPRINTF(CDD_INTR, (", writing %d bytes to TDR", n));
1194 		cd18xx_write_multi(sc, CD18xx_TDR, p->p_tba, n);
1195 		p->p_tbc -= n;
1196 		p->p_tba += n;
1197 	}
1198 
1199 	/* Disable transmit completion interrupts if we ran out of bytes. */
1200 	if (p->p_tbc == 0) {
1201 		/* Note that Tx interrupts should already be enabled */
1202 		if (ISSET(p->p_srer, CD18xx_SRER_Tx)) {
1203 			DPRINTF(CDD_INTR, (", disabling tx interrupts"));
1204 			CLR(p->p_srer, CD18xx_SRER_Tx);
1205 			cd18xx_write(sc, CD18xx_SRER, p->p_srer);
1206 		}
1207 		if (p->p_tx_busy) {
1208 			p->p_tx_busy = 0;
1209 			p->p_tx_done = 1;
1210 		}
1211 	}
1212 	*ns = 1;
1213 
1214 	/* finish the interrupt transaction with the IC */
1215 	cd18xx_write(sc, CD18xx_EOSRR, 0);
1216 	DPRINTF(CDD_INTR, (", done\n"));
1217 }
1218 
1219 /* modem signal change interrupt */
1220 static inline void
1221 cd18xx_mint(struct cd18xx_softc *sc, int *ns)
1222 {
1223 	struct cdtty_port *p;
1224 	u_int channel;
1225 	u_char msvr, delta;
1226 
1227 	/* work out the channel and softc */
1228 	channel = cd18xx_get_gscr1_channel(sc);
1229 	p = &sc->sc_ports[channel];
1230 	DPRINTF(CDD_INTR, ("%s: mint: channel %d", device_xname(sc->sc_dev), channel));
1231 	GOTINTR(sc, p);
1232 
1233 	/*
1234 	 * We ignore the MCR register, and handle detecting deltas
1235 	 * via software, like many other serial drivers.
1236 	 */
1237 	msvr = cd18xx_read(sc, CD18xx_MSVR);
1238 	delta = msvr ^ p->p_msvr;
1239 	DPRINTF(CDD_INTR, (", msvr %d", msvr));
1240 
1241 	/*
1242 	 * Process normal status changes
1243 	 */
1244 	if (ISSET(delta, p->p_msvr_mask)) {
1245 		SET(p->p_msvr_delta, delta);
1246 
1247 		DPRINTF(CDD_INTR, (", status changed delta %d", delta));
1248 		/*
1249 		 * Stop output immediately if we lose the output
1250 		 * flow control signal or carrier detect.
1251 		 */
1252 		if (ISSET(~msvr, p->p_msvr_mask)) {
1253 			p->p_tbc = 0;
1254 			p->p_heldtbc = 0;
1255 			/* Stop modem interrupt processing */
1256 		}
1257 		p->p_st_check = 1;
1258 		*ns = 1;
1259 	}
1260 
1261 	/* reset the modem signal register */
1262 	cd18xx_write(sc, CD18xx_MCR, 0);
1263 
1264 	/* finish the interrupt transaction with the IC */
1265 	cd18xx_write(sc, CD18xx_EOSRR, 0);
1266 	DPRINTF(CDD_INTR, (", done\n"));
1267 }
1268 
1269 /*
1270  * hardware interrupt routine.  call the relevant interrupt routines until
1271  * no interrupts are pending.
1272  *
1273  * note:  we do receive interrupts before all others (as we'd rather lose
1274  * a chance to transmit, than lose a character).  and we do transmit
1275  * interrupts before modem interrupts.
1276  *
1277  * we have to traverse all of the cd18xx's attached, unfortunately.
1278  */
1279 int
1280 cd18xx_hardintr(void *v)
1281 {
1282 	int i, rv = 0;
1283 	u_char ack;
1284 
1285 	DPRINTF(CDD_INTR, ("cd18xx_hardintr (ndevs %d):\n", clcd_cd.cd_ndevs));
1286 	for (i = 0; i < clcd_cd.cd_ndevs; i++)
1287 	{
1288 		struct cd18xx_softc *sc = device_lookup_private(&clcd_cd, i);
1289 		int status, ns = 0;
1290 		int count = 1;	/* process only 1 interrupts at a time for now */
1291 
1292 		if (sc == NULL)
1293 			continue;
1294 
1295 		DPRINTF(CDD_INTR, ("%s:", device_xname(sc->sc_dev)));
1296 		while (count-- &&
1297 		    (status = (cd18xx_read(sc, CD18xx_SRSR) &
1298 		     CD18xx_SRSR_PENDING))) {
1299 			rv = 1;
1300 
1301 			DPRINTF(CDD_INTR, (" status %x:", status));
1302 			if (ISSET(status, CD18xx_SRSR_RxPEND)) {
1303 				ack = (*sc->sc_ackfunc)(sc->sc_ackfunc_arg,
1304 				    CD18xx_INTRACK_RxINT);
1305 				DPRINTF(CDD_INTR, (" rx: ack1 %x\n", ack));
1306 				cd18xx_rint(sc, &ns);
1307 			}
1308 			if (ISSET(status, CD18xx_SRSR_TxPEND)) {
1309 				ack = (*sc->sc_ackfunc)(sc->sc_ackfunc_arg,
1310 				    CD18xx_INTRACK_TxINT);
1311 				DPRINTF(CDD_INTR, (" tx: ack1 %x\n", ack));
1312 				cd18xx_tint(sc, &ns);
1313 
1314 			}
1315 			if (ISSET(status, CD18xx_SRSR_MxPEND)) {
1316 				ack = (*sc->sc_ackfunc)(sc->sc_ackfunc_arg,
1317 				    CD18xx_INTRACK_MxINT);
1318 				DPRINTF(CDD_INTR, (" mx: ack1 %x\n", ack));
1319 				cd18xx_mint(sc, &ns);
1320 			}
1321 		}
1322 		if (ns)
1323 			softint_schedule(sc->sc_si);
1324 	}
1325 
1326 	return (rv);
1327 }
1328 
1329 /*
1330  * software interrupt
1331  */
1332 
1333 void
1334 cdtty_rxsoft(struct cd18xx_softc *sc, struct cdtty_port *p, struct tty *tp)
1335 {
1336 	u_char *get, *end;
1337 	u_int cc, scc;
1338 	u_char rcsr;
1339 	int code;
1340 	int s;
1341 
1342 	end = p->p_ebuf;
1343 	get = p->p_rbget;
1344 	scc = cc = cdtty_rbuf_size - p->p_rbavail;
1345 
1346 	if (cc == cdtty_rbuf_size) {
1347 		p->p_floods++;
1348 #if 0
1349 		if (p->p_errors++ == 0)
1350 			callout_reset(&p->p_diag_callout, 60 * hz,
1351 			    cdttydiag, p);
1352 #endif
1353 	}
1354 
1355 	while (cc) {
1356 		code = get[0];
1357 		rcsr = get[1];
1358 		if (ISSET(rcsr, CD18xx_RCSR_OVERRUNERR | CD18xx_RCSR_BREAK |
1359 				CD18xx_RCSR_FRAMERR | CD18xx_RCSR_PARITYERR)) {
1360 			if (ISSET(rcsr, CD18xx_RCSR_OVERRUNERR)) {
1361 				p->p_overflows++;
1362 #if 0
1363 				if (p->p_errors++ == 0)
1364 					callout_reset(&p->p_diag_callout,
1365 					    60 * hz, cdttydiag, p);
1366 #endif
1367 			}
1368 			if (ISSET(rcsr, CD18xx_RCSR_BREAK|CD18xx_RCSR_FRAMERR))
1369 				SET(code, TTY_FE);
1370 			if (ISSET(rcsr, CD18xx_RCSR_PARITYERR))
1371 				SET(code, TTY_PE);
1372 		}
1373 		if ((*tp->t_linesw->l_rint)(code, tp) == -1) {
1374 			/*
1375 			 * The line discipline's buffer is out of space.
1376 			 */
1377 			if (!ISSET(p->p_rx_flags, RX_TTY_BLOCKED)) {
1378 				/*
1379 				 * We're either not using flow control, or the
1380 				 * line discipline didn't tell us to block for
1381 				 * some reason.  Either way, we have no way to
1382 				 * know when there's more space available, so
1383 				 * just drop the rest of the data.
1384 				 */
1385 				get += cc << 1;
1386 				if (get >= end)
1387 					get -= cdtty_rbuf_size << 1;
1388 				cc = 0;
1389 			} else {
1390 				/*
1391 				 * Don't schedule any more receive processing
1392 				 * until the line discipline tells us there's
1393 				 * space available (through cdttyhwiflow()).
1394 				 * Leave the rest of the data in the input
1395 				 * buffer.
1396 				 */
1397 				SET(p->p_rx_flags, RX_TTY_OVERFLOWED);
1398 			}
1399 			break;
1400 		}
1401 		get += 2;
1402 		if (get >= end)
1403 			get = p->p_rbuf;
1404 		cc--;
1405 	}
1406 
1407 	if (cc != scc) {
1408 		p->p_rbget = get;
1409 		s = splserial();
1410 
1411 		cc = p->p_rbavail += scc - cc;
1412 		/* Buffers should be ok again, release possible block. */
1413 		if (cc >= p->p_r_lowat) {
1414 			if (ISSET(p->p_rx_flags, RX_IBUF_OVERFLOWED)) {
1415 				CLR(p->p_rx_flags, RX_IBUF_OVERFLOWED);
1416 				cd18xx_set_car(sc, CD18XX_CHANNEL(tp->t_dev));
1417 				SET(p->p_srer, CD18xx_SRER_Rx |
1418 					       CD18xx_SRER_RxSC |
1419 					       CD18xx_SRER_CD);
1420 				cd18xx_write(sc, CD18xx_SRER, p->p_srer);
1421 			}
1422 			if (ISSET(p->p_rx_flags, RX_IBUF_BLOCKED)) {
1423 				CLR(p->p_rx_flags, RX_IBUF_BLOCKED);
1424 				cdtty_hwiflow(sc, p);
1425 			}
1426 		}
1427 		splx(s);
1428 	}
1429 }
1430 
1431 void
1432 cdtty_txsoft(struct cd18xx_softc *sc, struct cdtty_port *p, struct tty *tp)
1433 {
1434 
1435 	CLR(tp->t_state, TS_BUSY);
1436 	if (ISSET(tp->t_state, TS_FLUSH))
1437 		CLR(tp->t_state, TS_FLUSH);
1438 	else
1439 		ndflush(&tp->t_outq, (int)(p->p_tba - tp->t_outq.c_cf));
1440 	(*tp->t_linesw->l_start)(tp);
1441 }
1442 
1443 void
1444 cdtty_stsoft(struct cd18xx_softc *sc, struct cdtty_port *p, struct tty *tp)
1445 {
1446 	u_char msvr, delta;
1447 	int s;
1448 
1449 	s = splserial();
1450 	msvr = p->p_msvr;
1451 	delta = p->p_msvr_delta;
1452 	p->p_msvr_delta = 0;
1453 	splx(s);
1454 
1455 	if (ISSET(delta, p->p_msvr_dcd)) {
1456 		/*
1457 		 * Inform the tty layer that carrier detect changed.
1458 		 */
1459 		(void) (*tp->t_linesw->l_modem)(tp, ISSET(msvr, CD18xx_MSVR_CD));
1460 	}
1461 
1462 	if (ISSET(delta, p->p_msvr_cts)) {
1463 		/* Block or unblock output according to flow control. */
1464 		if (ISSET(msvr, p->p_msvr_cts)) {
1465 			p->p_tx_stopped = 0;
1466 			(*tp->t_linesw->l_start)(tp);
1467 		} else {
1468 			p->p_tx_stopped = 1;
1469 		}
1470 	}
1471 }
1472 
1473 void
1474 cd18xx_softintr(void *v)
1475 {
1476 	struct cd18xx_softc *sc = v;
1477 	struct cdtty_port *p;
1478 	struct tty *tp;
1479 	int i;
1480 
1481 	for (i = 0; i < 8; i++) {
1482 		p = &sc->sc_ports[i];
1483 
1484 		tp = p->p_tty;
1485 		if (tp == NULL)
1486 			continue;
1487 		if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0)
1488 			continue;
1489 
1490 		if (p->p_rx_ready) {
1491 			p->p_rx_ready = 0;
1492 			cdtty_rxsoft(sc, p, tp);
1493 		}
1494 
1495 		if (p->p_st_check) {
1496 			p->p_st_check = 0;
1497 			cdtty_stsoft(sc, p, tp);
1498 		}
1499 
1500 		if (p->p_tx_done) {
1501 			p->p_tx_done = 0;
1502 			cdtty_txsoft(sc, p, tp);
1503 		}
1504 	}
1505 }
1506