xref: /netbsd-src/sys/arch/evbarm/dev/plcom.c (revision fad4c9f71477ae11cea2ee75ec82151ac770a534)
1 /*	$NetBSD: plcom.c,v 1.16 2006/05/14 21:55:10 elad Exp $	*/
2 
3 /*-
4  * Copyright (c) 2001 ARM Ltd
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  * 3. The name of the company may not be used to endorse or promote
16  *    products derived from this software without specific prior written
17  *    permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
20  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
21  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22  * IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
23  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
24  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
25  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  * Copyright (c) 1998, 1999 The NetBSD Foundation, Inc.
32  * All rights reserved.
33  *
34  * This code is derived from software contributed to The NetBSD Foundation
35  * by Charles M. Hannum.
36  *
37  * Redistribution and use in source and binary forms, with or without
38  * modification, are permitted provided that the following conditions
39  * are met:
40  * 1. Redistributions of source code must retain the above copyright
41  *    notice, this list of conditions and the following disclaimer.
42  * 2. Redistributions in binary form must reproduce the above copyright
43  *    notice, this list of conditions and the following disclaimer in the
44  *    documentation and/or other materials provided with the distribution.
45  * 3. All advertising materials mentioning features or use of this software
46  *    must display the following acknowledgement:
47  *        This product includes software developed by the NetBSD
48  *        Foundation, Inc. and its contributors.
49  * 4. Neither the name of The NetBSD Foundation nor the names of its
50  *    contributors may be used to endorse or promote products derived
51  *    from this software without specific prior written permission.
52  *
53  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
54  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
55  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
56  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
57  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
58  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
59  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
60  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
61  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
62  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
63  * POSSIBILITY OF SUCH DAMAGE.
64  */
65 
66 /*
67  * Copyright (c) 1991 The Regents of the University of California.
68  * All rights reserved.
69  *
70  * Redistribution and use in source and binary forms, with or without
71  * modification, are permitted provided that the following conditions
72  * are met:
73  * 1. Redistributions of source code must retain the above copyright
74  *    notice, this list of conditions and the following disclaimer.
75  * 2. Redistributions in binary form must reproduce the above copyright
76  *    notice, this list of conditions and the following disclaimer in the
77  *    documentation and/or other materials provided with the distribution.
78  * 3. Neither the name of the University nor the names of its contributors
79  *    may be used to endorse or promote products derived from this software
80  *    without specific prior written permission.
81  *
82  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
83  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
84  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
85  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
86  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
87  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
88  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
89  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
90  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
91  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
92  * SUCH DAMAGE.
93  *
94  *	@(#)com.c	7.5 (Berkeley) 5/16/91
95  */
96 
97 /*
98  * COM driver for the Prime Cell PL010 UART, which is similar to the 16C550,
99  * but has a completely different programmer's model.
100  * Derived from the NS16550AF com driver.
101  */
102 
103 #include <sys/cdefs.h>
104 __KERNEL_RCSID(0, "$NetBSD: plcom.c,v 1.16 2006/05/14 21:55:10 elad Exp $");
105 
106 #include "opt_plcom.h"
107 #include "opt_ddb.h"
108 #include "opt_kgdb.h"
109 #include "opt_lockdebug.h"
110 #include "opt_multiprocessor.h"
111 
112 #include "rnd.h"
113 #if NRND > 0 && defined(RND_COM)
114 #include <sys/rnd.h>
115 #endif
116 
117 /*
118  * Override cnmagic(9) macro before including <sys/systm.h>.
119  * We need to know if cn_check_magic triggered debugger, so set a flag.
120  * Callers of cn_check_magic must declare int cn_trapped = 0;
121  * XXX: this is *ugly*!
122  */
123 #define cn_trap()				\
124 	do {					\
125 		console_debugger();		\
126 		cn_trapped = 1;			\
127 	} while (/* CONSTCOND */ 0)
128 
129 #include <sys/param.h>
130 #include <sys/systm.h>
131 #include <sys/ioctl.h>
132 #include <sys/select.h>
133 #include <sys/tty.h>
134 #include <sys/proc.h>
135 #include <sys/user.h>
136 #include <sys/conf.h>
137 #include <sys/file.h>
138 #include <sys/uio.h>
139 #include <sys/kernel.h>
140 #include <sys/syslog.h>
141 #include <sys/types.h>
142 #include <sys/device.h>
143 #include <sys/malloc.h>
144 #include <sys/timepps.h>
145 #include <sys/vnode.h>
146 #include <sys/kauth.h>
147 
148 #include <machine/intr.h>
149 #include <machine/bus.h>
150 
151 #include <evbarm/dev/plcomreg.h>
152 #include <evbarm/dev/plcomvar.h>
153 
154 #include <dev/cons.h>
155 
156 static void plcom_enable_debugport (struct plcom_softc *);
157 
158 void	plcom_config	(struct plcom_softc *);
159 void	plcom_shutdown	(struct plcom_softc *);
160 int	plcomspeed	(long, long);
161 static	u_char	cflag2lcr (tcflag_t);
162 int	plcomparam	(struct tty *, struct termios *);
163 void	plcomstart	(struct tty *);
164 int	plcomhwiflow	(struct tty *, int);
165 
166 void	plcom_loadchannelregs (struct plcom_softc *);
167 void	plcom_hwiflow	(struct plcom_softc *);
168 void	plcom_break	(struct plcom_softc *, int);
169 void	plcom_modem	(struct plcom_softc *, int);
170 void	tiocm_to_plcom	(struct plcom_softc *, u_long, int);
171 int	plcom_to_tiocm	(struct plcom_softc *);
172 void	plcom_iflush	(struct plcom_softc *);
173 
174 int	plcom_common_getc (dev_t, bus_space_tag_t, bus_space_handle_t);
175 void	plcom_common_putc (dev_t, bus_space_tag_t, bus_space_handle_t, int);
176 
177 int	plcominit	(bus_space_tag_t, bus_addr_t, int, int, tcflag_t,
178 			    bus_space_handle_t *);
179 
180 dev_type_open(plcomopen);
181 dev_type_close(plcomclose);
182 dev_type_read(plcomread);
183 dev_type_write(plcomwrite);
184 dev_type_ioctl(plcomioctl);
185 dev_type_stop(plcomstop);
186 dev_type_tty(plcomtty);
187 dev_type_poll(plcompoll);
188 
189 int	plcomcngetc	(dev_t);
190 void	plcomcnputc	(dev_t, int);
191 void	plcomcnpollc	(dev_t, int);
192 
193 #define	integrate	static inline
194 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
195 void 	plcomsoft	(void *);
196 #else
197 #ifndef __NO_SOFT_SERIAL_INTERRUPT
198 void 	plcomsoft	(void);
199 #else
200 void 	plcomsoft	(void *);
201 struct callout plcomsoft_callout = CALLOUT_INITIALIZER;
202 #endif
203 #endif
204 integrate void plcom_rxsoft	(struct plcom_softc *, struct tty *);
205 integrate void plcom_txsoft	(struct plcom_softc *, struct tty *);
206 integrate void plcom_stsoft	(struct plcom_softc *, struct tty *);
207 integrate void plcom_schedrx	(struct plcom_softc *);
208 void	plcomdiag		(void *);
209 
210 extern struct cfdriver plcom_cd;
211 
212 const struct cdevsw plcom_cdevsw = {
213 	plcomopen, plcomclose, plcomread, plcomwrite, plcomioctl,
214 	plcomstop, plcomtty, plcompoll, nommap, ttykqfilter, D_TTY
215 };
216 
217 /*
218  * Make this an option variable one can patch.
219  * But be warned:  this must be a power of 2!
220  */
221 u_int plcom_rbuf_size = PLCOM_RING_SIZE;
222 
223 /* Stop input when 3/4 of the ring is full; restart when only 1/4 is full. */
224 u_int plcom_rbuf_hiwat = (PLCOM_RING_SIZE * 1) / 4;
225 u_int plcom_rbuf_lowat = (PLCOM_RING_SIZE * 3) / 4;
226 
227 static int	plcomconsunit = -1;
228 static bus_space_tag_t plcomconstag;
229 static bus_space_handle_t plcomconsioh;
230 static int	plcomconsattached;
231 static int plcomconsrate;
232 static tcflag_t plcomconscflag;
233 static struct cnm_state plcom_cnm_state;
234 
235 static int ppscap =
236 	PPS_TSFMT_TSPEC |
237 	PPS_CAPTUREASSERT |
238 	PPS_CAPTURECLEAR |
239 #ifdef  PPS_SYNC
240 	PPS_HARDPPSONASSERT | PPS_HARDPPSONCLEAR |
241 #endif	/* PPS_SYNC */
242 	PPS_OFFSETASSERT | PPS_OFFSETCLEAR;
243 
244 #ifndef __HAVE_GENERIC_SOFT_INTERRUPTS
245 #ifdef __NO_SOFT_SERIAL_INTERRUPT
246 volatile int	plcom_softintr_scheduled;
247 #endif
248 #endif
249 
250 #ifdef KGDB
251 #include <sys/kgdb.h>
252 
253 static int plcom_kgdb_unit;
254 static bus_space_tag_t plcom_kgdb_iot;
255 static bus_space_handle_t plcom_kgdb_ioh;
256 static int plcom_kgdb_attached;
257 
258 int	plcom_kgdb_getc (void *);
259 void	plcom_kgdb_putc (void *, int);
260 #endif /* KGDB */
261 
262 #define	PLCOMUNIT_MASK	0x7ffff
263 #define	PLCOMDIALOUT_MASK	0x80000
264 
265 #define	PLCOMUNIT(x)	(minor(x) & PLCOMUNIT_MASK)
266 #define	PLCOMDIALOUT(x)	(minor(x) & PLCOMDIALOUT_MASK)
267 
268 #define	PLCOM_ISALIVE(sc)	((sc)->enabled != 0 && \
269 				 device_is_active(&(sc)->sc_dev))
270 
271 #define	BR	BUS_SPACE_BARRIER_READ
272 #define	BW	BUS_SPACE_BARRIER_WRITE
273 #define PLCOM_BARRIER(t, h, f) bus_space_barrier((t), (h), 0, PLCOM_UART_SIZE, (f))
274 
275 #define PLCOM_LOCK(sc) simple_lock(&(sc)->sc_lock)
276 #define PLCOM_UNLOCK(sc) simple_unlock(&(sc)->sc_lock)
277 
278 int
279 plcomspeed(long speed, long frequency)
280 {
281 #define	divrnd(n, q)	(((n)*2/(q)+1)/2)	/* divide and round off */
282 
283 	int x, err;
284 
285 #if 0
286 	if (speed == 0)
287 		return 0;
288 #endif
289 	if (speed <= 0)
290 		return -1;
291 	x = divrnd(frequency / 16, speed);
292 	if (x <= 0)
293 		return -1;
294 	err = divrnd(((quad_t)frequency) * 1000 / 16, speed * x) - 1000;
295 	if (err < 0)
296 		err = -err;
297 	if (err > PLCOM_TOLERANCE)
298 		return -1;
299 	return x;
300 
301 #undef	divrnd
302 }
303 
304 #ifdef PLCOM_DEBUG
305 int	plcom_debug = 0;
306 
307 void plcomstatus (struct plcom_softc *, char *);
308 void
309 plcomstatus(struct plcom_softc *sc, char *str)
310 {
311 	struct tty *tp = sc->sc_tty;
312 
313 	printf("%s: %s %sclocal  %sdcd %sts_carr_on %sdtr %stx_stopped\n",
314 	    sc->sc_dev.dv_xname, str,
315 	    ISSET(tp->t_cflag, CLOCAL) ? "+" : "-",
316 	    ISSET(sc->sc_msr, MSR_DCD) ? "+" : "-",
317 	    ISSET(tp->t_state, TS_CARR_ON) ? "+" : "-",
318 	    ISSET(sc->sc_mcr, MCR_DTR) ? "+" : "-",
319 	    sc->sc_tx_stopped ? "+" : "-");
320 
321 	printf("%s: %s %scrtscts %scts %sts_ttstop  %srts %xrx_flags\n",
322 	    sc->sc_dev.dv_xname, str,
323 	    ISSET(tp->t_cflag, CRTSCTS) ? "+" : "-",
324 	    ISSET(sc->sc_msr, MSR_CTS) ? "+" : "-",
325 	    ISSET(tp->t_state, TS_TTSTOP) ? "+" : "-",
326 	    ISSET(sc->sc_mcr, MCR_RTS) ? "+" : "-",
327 	    sc->sc_rx_flags);
328 }
329 #endif
330 
331 int
332 plcomprobe1(bus_space_tag_t iot, bus_space_handle_t ioh)
333 {
334 	int data;
335 
336 	/* Disable the UART.  */
337 	bus_space_write_1(iot, ioh, plcom_cr, 0);
338 	/* Make sure the FIFO is off.  */
339 	bus_space_write_1(iot, ioh, plcom_lcr, LCR_8BITS);
340 	/* Disable interrupts.  */
341 	bus_space_write_1(iot, ioh, plcom_iir, 0);
342 
343 	/* Make sure we swallow anything in the receiving register.  */
344 	data = bus_space_read_1(iot, ioh, plcom_dr);
345 
346 	if (bus_space_read_1(iot, ioh, plcom_lcr) != LCR_8BITS)
347 		return 0;
348 
349 	data = bus_space_read_1(iot, ioh, plcom_fr) & (FR_RXFF | FR_RXFE);
350 
351 	if (data != FR_RXFE)
352 		return 0;
353 
354 	return 1;
355 }
356 
357 static void
358 plcom_enable_debugport(struct plcom_softc *sc)
359 {
360 	int s;
361 
362 	/* Turn on line break interrupt, set carrier. */
363 	s = splserial();
364 	PLCOM_LOCK(sc);
365 	sc->sc_cr = CR_RIE | CR_RTIE | CR_UARTEN;
366 	bus_space_write_1(sc->sc_iot, sc->sc_ioh, plcom_cr, sc->sc_cr);
367 	SET(sc->sc_mcr, MCR_DTR | MCR_RTS);
368 	/* XXX device_unit() abuse */
369 	sc->sc_set_mcr(sc->sc_set_mcr_arg, device_unit(&sc->sc_dev),
370 	    sc->sc_mcr);
371 	PLCOM_UNLOCK(sc);
372 	splx(s);
373 }
374 
375 void
376 plcom_attach_subr(struct plcom_softc *sc)
377 {
378 	int unit = sc->sc_iounit;
379 	bus_space_tag_t iot = sc->sc_iot;
380 	bus_space_handle_t ioh = sc->sc_ioh;
381 	struct tty *tp;
382 
383 	callout_init(&sc->sc_diag_callout);
384 	simple_lock_init(&sc->sc_lock);
385 
386 	/* Disable interrupts before configuring the device. */
387 	sc->sc_cr = 0;
388 
389 	if (plcomconstag && unit == plcomconsunit) {
390 		plcomconsattached = 1;
391 
392 		plcomconstag = iot;
393 		plcomconsioh = ioh;
394 
395 		/* Make sure the console is always "hardwired". */
396 		delay(1000);			/* wait for output to finish */
397 		SET(sc->sc_hwflags, PLCOM_HW_CONSOLE);
398 		SET(sc->sc_swflags, TIOCFLAG_SOFTCAR);
399 		/* Must re-enable the console immediately, or we will
400 		   hang when trying to print.  */
401 		sc->sc_cr = CR_UARTEN;
402 	}
403 
404 	bus_space_write_1(iot, ioh, plcom_cr, sc->sc_cr);
405 
406 	/* The PL010 has a 16-byte fifo, but the tx interrupt triggers when
407 	   there is space for 8 more bytes.  */
408 	sc->sc_fifolen = 8;
409 	printf("\n");
410 
411 	if (ISSET(sc->sc_hwflags, PLCOM_HW_TXFIFO_DISABLE)) {
412 		sc->sc_fifolen = 1;
413 		printf("%s: txfifo disabled\n", sc->sc_dev.dv_xname);
414 	}
415 
416 	if (sc->sc_fifolen > 1)
417 		SET(sc->sc_hwflags, PLCOM_HW_FIFO);
418 
419 	tp = ttymalloc();
420 	tp->t_oproc = plcomstart;
421 	tp->t_param = plcomparam;
422 	tp->t_hwiflow = plcomhwiflow;
423 
424 	sc->sc_tty = tp;
425 	sc->sc_rbuf = malloc(plcom_rbuf_size << 1, M_DEVBUF, M_NOWAIT);
426 	sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
427 	sc->sc_rbavail = plcom_rbuf_size;
428 	if (sc->sc_rbuf == NULL) {
429 		printf("%s: unable to allocate ring buffer\n",
430 		    sc->sc_dev.dv_xname);
431 		return;
432 	}
433 	sc->sc_ebuf = sc->sc_rbuf + (plcom_rbuf_size << 1);
434 
435 	tty_attach(tp);
436 
437 	if (ISSET(sc->sc_hwflags, PLCOM_HW_CONSOLE)) {
438 		int maj;
439 
440 		/* locate the major number */
441 		maj = cdevsw_lookup_major(&plcom_cdevsw);
442 
443 		cn_tab->cn_dev = makedev(maj, device_unit(&sc->sc_dev));
444 
445 		printf("%s: console\n", sc->sc_dev.dv_xname);
446 	}
447 
448 #ifdef KGDB
449 	/*
450 	 * Allow kgdb to "take over" this port.  If this is
451 	 * the kgdb device, it has exclusive use.
452 	 */
453 	if (iot == plcom_kgdb_iot && unit == plcom_kgdb_unit) {
454 		plcom_kgdb_attached = 1;
455 
456 		SET(sc->sc_hwflags, PLCOM_HW_KGDB);
457 		printf("%s: kgdb\n", sc->sc_dev.dv_xname);
458 	}
459 #endif
460 
461 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
462 	sc->sc_si = softintr_establish(IPL_SOFTSERIAL, plcomsoft, sc);
463 #endif
464 
465 #if NRND > 0 && defined(RND_COM)
466 	rnd_attach_source(&sc->rnd_source, sc->sc_dev.dv_xname,
467 			  RND_TYPE_TTY, 0);
468 #endif
469 
470 	/* if there are no enable/disable functions, assume the device
471 	   is always enabled */
472 	if (!sc->enable)
473 		sc->enabled = 1;
474 
475 	plcom_config(sc);
476 
477 	SET(sc->sc_hwflags, PLCOM_HW_DEV_OK);
478 }
479 
480 void
481 plcom_config(struct plcom_softc *sc)
482 {
483 	bus_space_tag_t iot = sc->sc_iot;
484 	bus_space_handle_t ioh = sc->sc_ioh;
485 
486 	/* Disable interrupts before configuring the device. */
487 	sc->sc_cr = 0;
488 	bus_space_write_1(iot, ioh, plcom_cr, sc->sc_cr);
489 
490 	if (ISSET(sc->sc_hwflags, PLCOM_HW_CONSOLE|PLCOM_HW_KGDB))
491 		plcom_enable_debugport(sc);
492 }
493 
494 int
495 plcom_detach(self, flags)
496 	struct device *self;
497 	int flags;
498 {
499 	struct plcom_softc *sc = (struct plcom_softc *)self;
500 	int maj, mn;
501 
502 	/* locate the major number */
503 	maj = cdevsw_lookup_major(&plcom_cdevsw);
504 
505 	/* Nuke the vnodes for any open instances. */
506 	mn = device_unit(self);
507 	vdevgone(maj, mn, mn, VCHR);
508 
509 	mn |= PLCOMDIALOUT_MASK;
510 	vdevgone(maj, mn, mn, VCHR);
511 
512 	/* Free the receive buffer. */
513 	free(sc->sc_rbuf, M_DEVBUF);
514 
515 	/* Detach and free the tty. */
516 	tty_detach(sc->sc_tty);
517 	ttyfree(sc->sc_tty);
518 
519 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
520 	/* Unhook the soft interrupt handler. */
521 	softintr_disestablish(sc->sc_si);
522 #endif
523 
524 #if NRND > 0 && defined(RND_COM)
525 	/* Unhook the entropy source. */
526 	rnd_detach_source(&sc->rnd_source);
527 #endif
528 
529 	return 0;
530 }
531 
532 int
533 plcom_activate(struct device *self, enum devact act)
534 {
535 	struct plcom_softc *sc = (struct plcom_softc *)self;
536 	int s, rv = 0;
537 
538 	s = splserial();
539 	PLCOM_LOCK(sc);
540 	switch (act) {
541 	case DVACT_ACTIVATE:
542 		rv = EOPNOTSUPP;
543 		break;
544 
545 	case DVACT_DEACTIVATE:
546 		if (sc->sc_hwflags & (PLCOM_HW_CONSOLE|PLCOM_HW_KGDB)) {
547 			rv = EBUSY;
548 			break;
549 		}
550 
551 		if (sc->disable != NULL && sc->enabled != 0) {
552 			(*sc->disable)(sc);
553 			sc->enabled = 0;
554 		}
555 		break;
556 	}
557 
558 	PLCOM_UNLOCK(sc);
559 	splx(s);
560 	return rv;
561 }
562 
563 void
564 plcom_shutdown(struct plcom_softc *sc)
565 {
566 	struct tty *tp = sc->sc_tty;
567 	int s;
568 
569 	s = splserial();
570 	PLCOM_LOCK(sc);
571 
572 	/* If we were asserting flow control, then deassert it. */
573 	SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
574 	plcom_hwiflow(sc);
575 
576 	/* Clear any break condition set with TIOCSBRK. */
577 	plcom_break(sc, 0);
578 
579 	/* Turn off PPS capture on last close. */
580 	sc->sc_ppsmask = 0;
581 	sc->ppsparam.mode = 0;
582 
583 	/*
584 	 * Hang up if necessary.  Wait a bit, so the other side has time to
585 	 * notice even if we immediately open the port again.
586 	 * Avoid tsleeping above splhigh().
587 	 */
588 	if (ISSET(tp->t_cflag, HUPCL)) {
589 		plcom_modem(sc, 0);
590 		PLCOM_UNLOCK(sc);
591 		splx(s);
592 		/* XXX tsleep will only timeout */
593 		(void) tsleep(sc, TTIPRI, ttclos, hz);
594 		s = splserial();
595 		PLCOM_LOCK(sc);
596 	}
597 
598 	/* Turn off interrupts. */
599 	if (ISSET(sc->sc_hwflags, PLCOM_HW_CONSOLE))
600 		/* interrupt on break */
601 		sc->sc_cr = CR_RIE | CR_RTIE | CR_UARTEN;
602 	else
603 		sc->sc_cr = 0;
604 	bus_space_write_1(sc->sc_iot, sc->sc_ioh, plcom_cr, sc->sc_cr);
605 
606 	if (sc->disable) {
607 #ifdef DIAGNOSTIC
608 		if (!sc->enabled)
609 			panic("plcom_shutdown: not enabled?");
610 #endif
611 		(*sc->disable)(sc);
612 		sc->enabled = 0;
613 	}
614 	PLCOM_UNLOCK(sc);
615 	splx(s);
616 }
617 
618 int
619 plcomopen(dev_t dev, int flag, int mode, struct lwp *l)
620 {
621 	struct plcom_softc *sc;
622 	struct tty *tp;
623 	int s, s2;
624 	int error;
625 
626 	sc = device_lookup(&plcom_cd, PLCOMUNIT(dev));
627 	if (sc == NULL || !ISSET(sc->sc_hwflags, PLCOM_HW_DEV_OK) ||
628 		sc->sc_rbuf == NULL)
629 		return ENXIO;
630 
631 	if (!device_is_active(&sc->sc_dev))
632 		return ENXIO;
633 
634 #ifdef KGDB
635 	/*
636 	 * If this is the kgdb port, no other use is permitted.
637 	 */
638 	if (ISSET(sc->sc_hwflags, PLCOM_HW_KGDB))
639 		return EBUSY;
640 #endif
641 
642 	tp = sc->sc_tty;
643 
644 	if (ISSET(tp->t_state, TS_ISOPEN) &&
645 	    ISSET(tp->t_state, TS_XCLUDE) &&
646 		kauth_authorize_generic(l->l_proc->p_cred,
647 				  KAUTH_GENERIC_ISSUSER,
648 				  &l->l_proc->p_acflag) != 0)
649 		return EBUSY;
650 
651 	s = spltty();
652 
653 	/*
654 	 * Do the following iff this is a first open.
655 	 */
656 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
657 		struct termios t;
658 
659 		tp->t_dev = dev;
660 
661 		s2 = splserial();
662 		PLCOM_LOCK(sc);
663 
664 		if (sc->enable) {
665 			if ((*sc->enable)(sc)) {
666 				PLCOM_UNLOCK(sc);
667 				splx(s2);
668 				splx(s);
669 				printf("%s: device enable failed\n",
670 				       sc->sc_dev.dv_xname);
671 				return EIO;
672 			}
673 			sc->enabled = 1;
674 			plcom_config(sc);
675 		}
676 
677 		/* Turn on interrupts. */
678 		/* IER_ERXRDY | IER_ERLS | IER_EMSC;  */
679 		sc->sc_cr = CR_RIE | CR_RTIE | CR_MSIE | CR_UARTEN;
680 		bus_space_write_1(sc->sc_iot, sc->sc_ioh, plcom_cr, sc->sc_cr);
681 
682 		/* Fetch the current modem control status, needed later. */
683 		sc->sc_msr = bus_space_read_1(sc->sc_iot, sc->sc_ioh, plcom_fr);
684 
685 		/* Clear PPS capture state on first open. */
686 		sc->sc_ppsmask = 0;
687 		sc->ppsparam.mode = 0;
688 
689 		PLCOM_UNLOCK(sc);
690 		splx(s2);
691 
692 		/*
693 		 * Initialize the termios status to the defaults.  Add in the
694 		 * sticky bits from TIOCSFLAGS.
695 		 */
696 		t.c_ispeed = 0;
697 		if (ISSET(sc->sc_hwflags, PLCOM_HW_CONSOLE)) {
698 			t.c_ospeed = plcomconsrate;
699 			t.c_cflag = plcomconscflag;
700 		} else {
701 			t.c_ospeed = TTYDEF_SPEED;
702 			t.c_cflag = TTYDEF_CFLAG;
703 		}
704 		if (ISSET(sc->sc_swflags, TIOCFLAG_CLOCAL))
705 			SET(t.c_cflag, CLOCAL);
706 		if (ISSET(sc->sc_swflags, TIOCFLAG_CRTSCTS))
707 			SET(t.c_cflag, CRTSCTS);
708 		if (ISSET(sc->sc_swflags, TIOCFLAG_MDMBUF))
709 			SET(t.c_cflag, MDMBUF);
710 		/* Make sure plcomparam() will do something. */
711 		tp->t_ospeed = 0;
712 		(void) plcomparam(tp, &t);
713 		tp->t_iflag = TTYDEF_IFLAG;
714 		tp->t_oflag = TTYDEF_OFLAG;
715 		tp->t_lflag = TTYDEF_LFLAG;
716 		ttychars(tp);
717 		ttsetwater(tp);
718 
719 		s2 = splserial();
720 		PLCOM_LOCK(sc);
721 
722 		/*
723 		 * Turn on DTR.  We must always do this, even if carrier is not
724 		 * present, because otherwise we'd have to use TIOCSDTR
725 		 * immediately after setting CLOCAL, which applications do not
726 		 * expect.  We always assert DTR while the device is open
727 		 * unless explicitly requested to deassert it.
728 		 */
729 		plcom_modem(sc, 1);
730 
731 		/* Clear the input ring, and unblock. */
732 		sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
733 		sc->sc_rbavail = plcom_rbuf_size;
734 		plcom_iflush(sc);
735 		CLR(sc->sc_rx_flags, RX_ANY_BLOCK);
736 		plcom_hwiflow(sc);
737 
738 #ifdef PLCOM_DEBUG
739 		if (plcom_debug)
740 			plcomstatus(sc, "plcomopen  ");
741 #endif
742 
743 		PLCOM_UNLOCK(sc);
744 		splx(s2);
745 	}
746 
747 	splx(s);
748 
749 	error = ttyopen(tp, PLCOMDIALOUT(dev), ISSET(flag, O_NONBLOCK));
750 	if (error)
751 		goto bad;
752 
753 	error = (*tp->t_linesw->l_open)(dev, tp);
754 	if (error)
755 		goto bad;
756 
757 	return 0;
758 
759 bad:
760 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
761 		/*
762 		 * We failed to open the device, and nobody else had it opened.
763 		 * Clean up the state as appropriate.
764 		 */
765 		plcom_shutdown(sc);
766 	}
767 
768 	return error;
769 }
770 
771 int
772 plcomclose(dev_t dev, int flag, int mode, struct lwp *l)
773 {
774 	struct plcom_softc *sc = device_lookup(&plcom_cd, PLCOMUNIT(dev));
775 	struct tty *tp = sc->sc_tty;
776 
777 	/* XXX This is for cons.c. */
778 	if (!ISSET(tp->t_state, TS_ISOPEN))
779 		return 0;
780 
781 	(*tp->t_linesw->l_close)(tp, flag);
782 	ttyclose(tp);
783 
784 	if (PLCOM_ISALIVE(sc) == 0)
785 		return 0;
786 
787 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
788 		/*
789 		 * Although we got a last close, the device may still be in
790 		 * use; e.g. if this was the dialout node, and there are still
791 		 * processes waiting for carrier on the non-dialout node.
792 		 */
793 		plcom_shutdown(sc);
794 	}
795 
796 	return 0;
797 }
798 
799 int
800 plcomread(dev_t dev, struct uio *uio, int flag)
801 {
802 	struct plcom_softc *sc = device_lookup(&plcom_cd, PLCOMUNIT(dev));
803 	struct tty *tp = sc->sc_tty;
804 
805 	if (PLCOM_ISALIVE(sc) == 0)
806 		return EIO;
807 
808 	return (*tp->t_linesw->l_read)(tp, uio, flag);
809 }
810 
811 int
812 plcomwrite(dev_t dev, struct uio *uio, int flag)
813 {
814 	struct plcom_softc *sc = device_lookup(&plcom_cd, PLCOMUNIT(dev));
815 	struct tty *tp = sc->sc_tty;
816 
817 	if (PLCOM_ISALIVE(sc) == 0)
818 		return EIO;
819 
820 	return (*tp->t_linesw->l_write)(tp, uio, flag);
821 }
822 
823 int
824 plcompoll(dev_t dev, int events, struct lwp *l)
825 {
826 	struct plcom_softc *sc = device_lookup(&plcom_cd, PLCOMUNIT(dev));
827 	struct tty *tp = sc->sc_tty;
828 
829 	if (PLCOM_ISALIVE(sc) == 0)
830 		return EIO;
831 
832 	return (*tp->t_linesw->l_poll)(tp, events, l);
833 }
834 
835 struct tty *
836 plcomtty(dev_t dev)
837 {
838 	struct plcom_softc *sc = device_lookup(&plcom_cd, PLCOMUNIT(dev));
839 	struct tty *tp = sc->sc_tty;
840 
841 	return tp;
842 }
843 
844 int
845 plcomioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct lwp *l)
846 {
847 	struct plcom_softc *sc = device_lookup(&plcom_cd, PLCOMUNIT(dev));
848 	struct tty *tp = sc->sc_tty;
849 	int error;
850 	int s;
851 
852 	if (PLCOM_ISALIVE(sc) == 0)
853 		return EIO;
854 
855 	error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, l);
856 	if (error != EPASSTHROUGH)
857 		return error;
858 
859 	error = ttioctl(tp, cmd, data, flag, l);
860 	if (error != EPASSTHROUGH)
861 		return error;
862 
863 	error = 0;
864 
865 	s = splserial();
866 	PLCOM_LOCK(sc);
867 
868 	switch (cmd) {
869 	case TIOCSBRK:
870 		plcom_break(sc, 1);
871 		break;
872 
873 	case TIOCCBRK:
874 		plcom_break(sc, 0);
875 		break;
876 
877 	case TIOCSDTR:
878 		plcom_modem(sc, 1);
879 		break;
880 
881 	case TIOCCDTR:
882 		plcom_modem(sc, 0);
883 		break;
884 
885 	case TIOCGFLAGS:
886 		*(int *)data = sc->sc_swflags;
887 		break;
888 
889 	case TIOCSFLAGS:
890 		error = kauth_authorize_generic(l->l_proc->p_cred,
891 					  KAUTH_GENERIC_ISSUSER,
892 					  &l->l_proc->p_acflag);
893 		if (error)
894 			break;
895 		sc->sc_swflags = *(int *)data;
896 		break;
897 
898 	case TIOCMSET:
899 	case TIOCMBIS:
900 	case TIOCMBIC:
901 		tiocm_to_plcom(sc, cmd, *(int *)data);
902 		break;
903 
904 	case TIOCMGET:
905 		*(int *)data = plcom_to_tiocm(sc);
906 		break;
907 
908 	case PPS_IOC_CREATE:
909 		break;
910 
911 	case PPS_IOC_DESTROY:
912 		break;
913 
914 	case PPS_IOC_GETPARAMS: {
915 		pps_params_t *pp;
916 		pp = (pps_params_t *)data;
917 		*pp = sc->ppsparam;
918 		break;
919 	}
920 
921 	case PPS_IOC_SETPARAMS: {
922 	  	pps_params_t *pp;
923 		int mode;
924 		pp = (pps_params_t *)data;
925 		if (pp->mode & ~ppscap) {
926 			error = EINVAL;
927 			break;
928 		}
929 		sc->ppsparam = *pp;
930 	 	/*
931 		 * Compute msr masks from user-specified timestamp state.
932 		 */
933 		mode = sc->ppsparam.mode;
934 #ifdef	PPS_SYNC
935 		if (mode & PPS_HARDPPSONASSERT) {
936 			mode |= PPS_CAPTUREASSERT;
937 			/* XXX revoke any previous HARDPPS source */
938 		}
939 		if (mode & PPS_HARDPPSONCLEAR) {
940 			mode |= PPS_CAPTURECLEAR;
941 			/* XXX revoke any previous HARDPPS source */
942 		}
943 #endif	/* PPS_SYNC */
944 		switch (mode & PPS_CAPTUREBOTH) {
945 		case 0:
946 			sc->sc_ppsmask = 0;
947 			break;
948 
949 		case PPS_CAPTUREASSERT:
950 			sc->sc_ppsmask = MSR_DCD;
951 			sc->sc_ppsassert = MSR_DCD;
952 			sc->sc_ppsclear = -1;
953 			break;
954 
955 		case PPS_CAPTURECLEAR:
956 			sc->sc_ppsmask = MSR_DCD;
957 			sc->sc_ppsassert = -1;
958 			sc->sc_ppsclear = 0;
959 			break;
960 
961 		case PPS_CAPTUREBOTH:
962 			sc->sc_ppsmask = MSR_DCD;
963 			sc->sc_ppsassert = MSR_DCD;
964 			sc->sc_ppsclear = 0;
965 			break;
966 
967 		default:
968 			error = EINVAL;
969 			break;
970 		}
971 		break;
972 	}
973 
974 	case PPS_IOC_GETCAP:
975 		*(int*)data = ppscap;
976 		break;
977 
978 	case PPS_IOC_FETCH: {
979 		pps_info_t *pi;
980 		pi = (pps_info_t *)data;
981 		*pi = sc->ppsinfo;
982 		break;
983 	}
984 
985 	case TIOCDCDTIMESTAMP:	/* XXX old, overloaded  API used by xntpd v3 */
986 		/*
987 		 * Some GPS clocks models use the falling rather than
988 		 * rising edge as the on-the-second signal.
989 		 * The old API has no way to specify PPS polarity.
990 		 */
991 		sc->sc_ppsmask = MSR_DCD;
992 #ifndef PPS_TRAILING_EDGE
993 		sc->sc_ppsassert = MSR_DCD;
994 		sc->sc_ppsclear = -1;
995 		TIMESPEC_TO_TIMEVAL((struct timeval *)data,
996 		    &sc->ppsinfo.assert_timestamp);
997 #else
998 		sc->sc_ppsassert = -1
999 		sc->sc_ppsclear = 0;
1000 		TIMESPEC_TO_TIMEVAL((struct timeval *)data,
1001 		    &sc->ppsinfo.clear_timestamp);
1002 #endif
1003 		break;
1004 
1005 	default:
1006 		error = EPASSTHROUGH;
1007 		break;
1008 	}
1009 
1010 	PLCOM_UNLOCK(sc);
1011 	splx(s);
1012 
1013 #ifdef PLCOM_DEBUG
1014 	if (plcom_debug)
1015 		plcomstatus(sc, "plcomioctl ");
1016 #endif
1017 
1018 	return error;
1019 }
1020 
1021 integrate void
1022 plcom_schedrx(struct plcom_softc *sc)
1023 {
1024 
1025 	sc->sc_rx_ready = 1;
1026 
1027 	/* Wake up the poller. */
1028 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
1029 	softintr_schedule(sc->sc_si);
1030 #else
1031 #ifndef __NO_SOFT_SERIAL_INTERRUPT
1032 	setsoftserial();
1033 #else
1034 	if (!plcom_softintr_scheduled) {
1035 		plcom_softintr_scheduled = 1;
1036 		callout_reset(&plcomsoft_callout, 1, plcomsoft, NULL);
1037 	}
1038 #endif
1039 #endif
1040 }
1041 
1042 void
1043 plcom_break(struct plcom_softc *sc, int onoff)
1044 {
1045 
1046 	if (onoff)
1047 		SET(sc->sc_lcr, LCR_BRK);
1048 	else
1049 		CLR(sc->sc_lcr, LCR_BRK);
1050 
1051 	if (!sc->sc_heldchange) {
1052 		if (sc->sc_tx_busy) {
1053 			sc->sc_heldtbc = sc->sc_tbc;
1054 			sc->sc_tbc = 0;
1055 			sc->sc_heldchange = 1;
1056 		} else
1057 			plcom_loadchannelregs(sc);
1058 	}
1059 }
1060 
1061 void
1062 plcom_modem(struct plcom_softc *sc, int onoff)
1063 {
1064 
1065 	if (sc->sc_mcr_dtr == 0)
1066 		return;
1067 
1068 	if (onoff)
1069 		SET(sc->sc_mcr, sc->sc_mcr_dtr);
1070 	else
1071 		CLR(sc->sc_mcr, sc->sc_mcr_dtr);
1072 
1073 	if (!sc->sc_heldchange) {
1074 		if (sc->sc_tx_busy) {
1075 			sc->sc_heldtbc = sc->sc_tbc;
1076 			sc->sc_tbc = 0;
1077 			sc->sc_heldchange = 1;
1078 		} else
1079 			plcom_loadchannelregs(sc);
1080 	}
1081 }
1082 
1083 void
1084 tiocm_to_plcom(struct plcom_softc *sc, u_long how, int ttybits)
1085 {
1086 	u_char plcombits;
1087 
1088 	plcombits = 0;
1089 	if (ISSET(ttybits, TIOCM_DTR))
1090 		SET(plcombits, MCR_DTR);
1091 	if (ISSET(ttybits, TIOCM_RTS))
1092 		SET(plcombits, MCR_RTS);
1093 
1094 	switch (how) {
1095 	case TIOCMBIC:
1096 		CLR(sc->sc_mcr, plcombits);
1097 		break;
1098 
1099 	case TIOCMBIS:
1100 		SET(sc->sc_mcr, plcombits);
1101 		break;
1102 
1103 	case TIOCMSET:
1104 		CLR(sc->sc_mcr, MCR_DTR | MCR_RTS);
1105 		SET(sc->sc_mcr, plcombits);
1106 		break;
1107 	}
1108 
1109 	if (!sc->sc_heldchange) {
1110 		if (sc->sc_tx_busy) {
1111 			sc->sc_heldtbc = sc->sc_tbc;
1112 			sc->sc_tbc = 0;
1113 			sc->sc_heldchange = 1;
1114 		} else
1115 			plcom_loadchannelregs(sc);
1116 	}
1117 }
1118 
1119 int
1120 plcom_to_tiocm(struct plcom_softc *sc)
1121 {
1122 	u_char plcombits;
1123 	int ttybits = 0;
1124 
1125 	plcombits = sc->sc_mcr;
1126 	if (ISSET(plcombits, MCR_DTR))
1127 		SET(ttybits, TIOCM_DTR);
1128 	if (ISSET(plcombits, MCR_RTS))
1129 		SET(ttybits, TIOCM_RTS);
1130 
1131 	plcombits = sc->sc_msr;
1132 	if (ISSET(plcombits, MSR_DCD))
1133 		SET(ttybits, TIOCM_CD);
1134 	if (ISSET(plcombits, MSR_CTS))
1135 		SET(ttybits, TIOCM_CTS);
1136 	if (ISSET(plcombits, MSR_DSR))
1137 		SET(ttybits, TIOCM_DSR);
1138 
1139 	if (sc->sc_cr != 0)
1140 		SET(ttybits, TIOCM_LE);
1141 
1142 	return ttybits;
1143 }
1144 
1145 static u_char
1146 cflag2lcr(tcflag_t cflag)
1147 {
1148 	u_char lcr = 0;
1149 
1150 	switch (ISSET(cflag, CSIZE)) {
1151 	case CS5:
1152 		SET(lcr, LCR_5BITS);
1153 		break;
1154 	case CS6:
1155 		SET(lcr, LCR_6BITS);
1156 		break;
1157 	case CS7:
1158 		SET(lcr, LCR_7BITS);
1159 		break;
1160 	case CS8:
1161 		SET(lcr, LCR_8BITS);
1162 		break;
1163 	}
1164 	if (ISSET(cflag, PARENB)) {
1165 		SET(lcr, LCR_PEN);
1166 		if (!ISSET(cflag, PARODD))
1167 			SET(lcr, LCR_EPS);
1168 	}
1169 	if (ISSET(cflag, CSTOPB))
1170 		SET(lcr, LCR_STP2);
1171 
1172 	return lcr;
1173 }
1174 
1175 int
1176 plcomparam(struct tty *tp, struct termios *t)
1177 {
1178 	struct plcom_softc *sc = device_lookup(&plcom_cd, PLCOMUNIT(tp->t_dev));
1179 	int ospeed;
1180 	u_char lcr;
1181 	int s;
1182 
1183 	if (PLCOM_ISALIVE(sc) == 0)
1184 		return EIO;
1185 
1186 	ospeed = plcomspeed(t->c_ospeed, sc->sc_frequency);
1187 
1188 	/* Check requested parameters. */
1189 	if (ospeed < 0)
1190 		return EINVAL;
1191 	if (t->c_ispeed && t->c_ispeed != t->c_ospeed)
1192 		return EINVAL;
1193 
1194 	/*
1195 	 * For the console, always force CLOCAL and !HUPCL, so that the port
1196 	 * is always active.
1197 	 */
1198 	if (ISSET(sc->sc_swflags, TIOCFLAG_SOFTCAR) ||
1199 	    ISSET(sc->sc_hwflags, PLCOM_HW_CONSOLE)) {
1200 		SET(t->c_cflag, CLOCAL);
1201 		CLR(t->c_cflag, HUPCL);
1202 	}
1203 
1204 	/*
1205 	 * If there were no changes, don't do anything.  This avoids dropping
1206 	 * input and improves performance when all we did was frob things like
1207 	 * VMIN and VTIME.
1208 	 */
1209 	if (tp->t_ospeed == t->c_ospeed &&
1210 	    tp->t_cflag == t->c_cflag)
1211 		return 0;
1212 
1213 	lcr = ISSET(sc->sc_lcr, LCR_BRK) | cflag2lcr(t->c_cflag);
1214 
1215 	s = splserial();
1216 	PLCOM_LOCK(sc);
1217 
1218 	sc->sc_lcr = lcr;
1219 
1220 	/*
1221 	 * PL010 has a fixed-length FIFO trigger point.
1222 	 */
1223 	if (ISSET(sc->sc_hwflags, PLCOM_HW_FIFO))
1224 		sc->sc_fifo = 1;
1225 	else
1226 		sc->sc_fifo = 0;
1227 
1228 	if (sc->sc_fifo)
1229 		SET(sc->sc_lcr, LCR_FEN);
1230 
1231 	/*
1232 	 * If we're not in a mode that assumes a connection is present, then
1233 	 * ignore carrier changes.
1234 	 */
1235 	if (ISSET(t->c_cflag, CLOCAL | MDMBUF))
1236 		sc->sc_msr_dcd = 0;
1237 	else
1238 		sc->sc_msr_dcd = MSR_DCD;
1239 	/*
1240 	 * Set the flow control pins depending on the current flow control
1241 	 * mode.
1242 	 */
1243 	if (ISSET(t->c_cflag, CRTSCTS)) {
1244 		sc->sc_mcr_dtr = MCR_DTR;
1245 		sc->sc_mcr_rts = MCR_RTS;
1246 		sc->sc_msr_cts = MSR_CTS;
1247 	} else if (ISSET(t->c_cflag, MDMBUF)) {
1248 		/*
1249 		 * For DTR/DCD flow control, make sure we don't toggle DTR for
1250 		 * carrier detection.
1251 		 */
1252 		sc->sc_mcr_dtr = 0;
1253 		sc->sc_mcr_rts = MCR_DTR;
1254 		sc->sc_msr_cts = MSR_DCD;
1255 	} else {
1256 		/*
1257 		 * If no flow control, then always set RTS.  This will make
1258 		 * the other side happy if it mistakenly thinks we're doing
1259 		 * RTS/CTS flow control.
1260 		 */
1261 		sc->sc_mcr_dtr = MCR_DTR | MCR_RTS;
1262 		sc->sc_mcr_rts = 0;
1263 		sc->sc_msr_cts = 0;
1264 		if (ISSET(sc->sc_mcr, MCR_DTR))
1265 			SET(sc->sc_mcr, MCR_RTS);
1266 		else
1267 			CLR(sc->sc_mcr, MCR_RTS);
1268 	}
1269 	sc->sc_msr_mask = sc->sc_msr_cts | sc->sc_msr_dcd;
1270 
1271 #if 0
1272 	if (ospeed == 0)
1273 		CLR(sc->sc_mcr, sc->sc_mcr_dtr);
1274 	else
1275 		SET(sc->sc_mcr, sc->sc_mcr_dtr);
1276 #endif
1277 
1278 	sc->sc_dlbl = ospeed;
1279 	sc->sc_dlbh = ospeed >> 8;
1280 
1281 	/* And copy to tty. */
1282 	tp->t_ispeed = 0;
1283 	tp->t_ospeed = t->c_ospeed;
1284 	tp->t_cflag = t->c_cflag;
1285 
1286 	if (!sc->sc_heldchange) {
1287 		if (sc->sc_tx_busy) {
1288 			sc->sc_heldtbc = sc->sc_tbc;
1289 			sc->sc_tbc = 0;
1290 			sc->sc_heldchange = 1;
1291 		} else
1292 			plcom_loadchannelregs(sc);
1293 	}
1294 
1295 	if (!ISSET(t->c_cflag, CHWFLOW)) {
1296 		/* Disable the high water mark. */
1297 		sc->sc_r_hiwat = 0;
1298 		sc->sc_r_lowat = 0;
1299 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
1300 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1301 			plcom_schedrx(sc);
1302 		}
1303 		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED)) {
1304 			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED);
1305 			plcom_hwiflow(sc);
1306 		}
1307 	} else {
1308 		sc->sc_r_hiwat = plcom_rbuf_hiwat;
1309 		sc->sc_r_lowat = plcom_rbuf_lowat;
1310 	}
1311 
1312 	PLCOM_UNLOCK(sc);
1313 	splx(s);
1314 
1315 	/*
1316 	 * Update the tty layer's idea of the carrier bit, in case we changed
1317 	 * CLOCAL or MDMBUF.  We don't hang up here; we only do that by
1318 	 * explicit request.
1319 	 */
1320 	(void) (*tp->t_linesw->l_modem)(tp, ISSET(sc->sc_msr, MSR_DCD));
1321 
1322 #ifdef PLCOM_DEBUG
1323 	if (plcom_debug)
1324 		plcomstatus(sc, "plcomparam ");
1325 #endif
1326 
1327 	if (!ISSET(t->c_cflag, CHWFLOW)) {
1328 		if (sc->sc_tx_stopped) {
1329 			sc->sc_tx_stopped = 0;
1330 			plcomstart(tp);
1331 		}
1332 	}
1333 
1334 	return 0;
1335 }
1336 
1337 void
1338 plcom_iflush(struct plcom_softc *sc)
1339 {
1340 	bus_space_tag_t iot = sc->sc_iot;
1341 	bus_space_handle_t ioh = sc->sc_ioh;
1342 #ifdef DIAGNOSTIC
1343 	int reg;
1344 #endif
1345 	int timo;
1346 
1347 #ifdef DIAGNOSTIC
1348 	reg = 0xffff;
1349 #endif
1350 	timo = 50000;
1351 	/* flush any pending I/O */
1352 	while (! ISSET(bus_space_read_1(iot, ioh, plcom_fr), FR_RXFE)
1353 	    && --timo)
1354 #ifdef DIAGNOSTIC
1355 		reg =
1356 #else
1357 		    (void)
1358 #endif
1359 		    bus_space_read_1(iot, ioh, plcom_dr);
1360 #ifdef DIAGNOSTIC
1361 	if (!timo)
1362 		printf("%s: plcom_iflush timeout %02x\n", sc->sc_dev.dv_xname,
1363 		       reg);
1364 #endif
1365 }
1366 
1367 void
1368 plcom_loadchannelregs(struct plcom_softc *sc)
1369 {
1370 	bus_space_tag_t iot = sc->sc_iot;
1371 	bus_space_handle_t ioh = sc->sc_ioh;
1372 
1373 	/* XXXXX necessary? */
1374 	plcom_iflush(sc);
1375 
1376 	bus_space_write_1(iot, ioh, plcom_cr, 0);
1377 
1378 	bus_space_write_1(iot, ioh, plcom_dlbl, sc->sc_dlbl);
1379 	bus_space_write_1(iot, ioh, plcom_dlbh, sc->sc_dlbh);
1380 	bus_space_write_1(iot, ioh, plcom_lcr, sc->sc_lcr);
1381 	/* XXX device_unit() abuse */
1382 	sc->sc_set_mcr(sc->sc_set_mcr_arg, device_unit(&sc->sc_dev),
1383 	    sc->sc_mcr_active = sc->sc_mcr);
1384 
1385 	bus_space_write_1(iot, ioh, plcom_cr, sc->sc_cr);
1386 }
1387 
1388 int
1389 plcomhwiflow(struct tty *tp, int block)
1390 {
1391 	struct plcom_softc *sc = device_lookup(&plcom_cd, PLCOMUNIT(tp->t_dev));
1392 	int s;
1393 
1394 	if (PLCOM_ISALIVE(sc) == 0)
1395 		return 0;
1396 
1397 	if (sc->sc_mcr_rts == 0)
1398 		return 0;
1399 
1400 	s = splserial();
1401 	PLCOM_LOCK(sc);
1402 
1403 	if (block) {
1404 		if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1405 			SET(sc->sc_rx_flags, RX_TTY_BLOCKED);
1406 			plcom_hwiflow(sc);
1407 		}
1408 	} else {
1409 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
1410 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1411 			plcom_schedrx(sc);
1412 		}
1413 		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1414 			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED);
1415 			plcom_hwiflow(sc);
1416 		}
1417 	}
1418 
1419 	PLCOM_UNLOCK(sc);
1420 	splx(s);
1421 	return 1;
1422 }
1423 
1424 /*
1425  * (un)block input via hw flowcontrol
1426  */
1427 void
1428 plcom_hwiflow(struct plcom_softc *sc)
1429 {
1430 	if (sc->sc_mcr_rts == 0)
1431 		return;
1432 
1433 	if (ISSET(sc->sc_rx_flags, RX_ANY_BLOCK)) {
1434 		CLR(sc->sc_mcr, sc->sc_mcr_rts);
1435 		CLR(sc->sc_mcr_active, sc->sc_mcr_rts);
1436 	} else {
1437 		SET(sc->sc_mcr, sc->sc_mcr_rts);
1438 		SET(sc->sc_mcr_active, sc->sc_mcr_rts);
1439 	}
1440 	/* XXX device_unit() abuse */
1441 	sc->sc_set_mcr(sc->sc_set_mcr_arg, device_unit(&sc->sc_dev),
1442 	    sc->sc_mcr_active);
1443 }
1444 
1445 
1446 void
1447 plcomstart(struct tty *tp)
1448 {
1449 	struct plcom_softc *sc = device_lookup(&plcom_cd, PLCOMUNIT(tp->t_dev));
1450 	bus_space_tag_t iot = sc->sc_iot;
1451 	bus_space_handle_t ioh = sc->sc_ioh;
1452 	int s;
1453 
1454 	if (PLCOM_ISALIVE(sc) == 0)
1455 		return;
1456 
1457 	s = spltty();
1458 	if (ISSET(tp->t_state, TS_BUSY | TS_TIMEOUT | TS_TTSTOP))
1459 		goto out;
1460 	if (sc->sc_tx_stopped)
1461 		goto out;
1462 
1463 	if (tp->t_outq.c_cc <= tp->t_lowat) {
1464 		if (ISSET(tp->t_state, TS_ASLEEP)) {
1465 			CLR(tp->t_state, TS_ASLEEP);
1466 			wakeup(&tp->t_outq);
1467 		}
1468 		selwakeup(&tp->t_wsel);
1469 		if (tp->t_outq.c_cc == 0)
1470 			goto out;
1471 	}
1472 
1473 	/* Grab the first contiguous region of buffer space. */
1474 	{
1475 		u_char *tba;
1476 		int tbc;
1477 
1478 		tba = tp->t_outq.c_cf;
1479 		tbc = ndqb(&tp->t_outq, 0);
1480 
1481 		(void)splserial();
1482 		PLCOM_LOCK(sc);
1483 
1484 		sc->sc_tba = tba;
1485 		sc->sc_tbc = tbc;
1486 	}
1487 
1488 	SET(tp->t_state, TS_BUSY);
1489 	sc->sc_tx_busy = 1;
1490 
1491 	/* Enable transmit completion interrupts if necessary. */
1492 	if (!ISSET(sc->sc_cr, CR_TIE)) {
1493 		SET(sc->sc_cr, CR_TIE);
1494 		bus_space_write_1(iot, ioh, plcom_cr, sc->sc_cr);
1495 	}
1496 
1497 	/* Output the first chunk of the contiguous buffer. */
1498 	{
1499 		int n;
1500 
1501 		n = sc->sc_tbc;
1502 		if (n > sc->sc_fifolen)
1503 			n = sc->sc_fifolen;
1504 		bus_space_write_multi_1(iot, ioh, plcom_dr, sc->sc_tba, n);
1505 		sc->sc_tbc -= n;
1506 		sc->sc_tba += n;
1507 	}
1508 	PLCOM_UNLOCK(sc);
1509 out:
1510 	splx(s);
1511 	return;
1512 }
1513 
1514 /*
1515  * Stop output on a line.
1516  */
1517 void
1518 plcomstop(struct tty *tp, int flag)
1519 {
1520 	struct plcom_softc *sc = device_lookup(&plcom_cd, PLCOMUNIT(tp->t_dev));
1521 	int s;
1522 
1523 	s = splserial();
1524 	PLCOM_LOCK(sc);
1525 	if (ISSET(tp->t_state, TS_BUSY)) {
1526 		/* Stop transmitting at the next chunk. */
1527 		sc->sc_tbc = 0;
1528 		sc->sc_heldtbc = 0;
1529 		if (!ISSET(tp->t_state, TS_TTSTOP))
1530 			SET(tp->t_state, TS_FLUSH);
1531 	}
1532 	PLCOM_UNLOCK(sc);
1533 	splx(s);
1534 }
1535 
1536 void
1537 plcomdiag(void *arg)
1538 {
1539 	struct plcom_softc *sc = arg;
1540 	int overflows, floods;
1541 	int s;
1542 
1543 	s = splserial();
1544 	PLCOM_LOCK(sc);
1545 	overflows = sc->sc_overflows;
1546 	sc->sc_overflows = 0;
1547 	floods = sc->sc_floods;
1548 	sc->sc_floods = 0;
1549 	sc->sc_errors = 0;
1550 	PLCOM_UNLOCK(sc);
1551 	splx(s);
1552 
1553 	log(LOG_WARNING, "%s: %d silo overflow%s, %d ibuf flood%s\n",
1554 	    sc->sc_dev.dv_xname,
1555 	    overflows, overflows == 1 ? "" : "s",
1556 	    floods, floods == 1 ? "" : "s");
1557 }
1558 
1559 integrate void
1560 plcom_rxsoft(struct plcom_softc *sc, struct tty *tp)
1561 {
1562 	int (*rint) (int, struct tty *) = tp->t_linesw->l_rint;
1563 	u_char *get, *end;
1564 	u_int cc, scc;
1565 	u_char rsr;
1566 	int code;
1567 	int s;
1568 
1569 	end = sc->sc_ebuf;
1570 	get = sc->sc_rbget;
1571 	scc = cc = plcom_rbuf_size - sc->sc_rbavail;
1572 
1573 	if (cc == plcom_rbuf_size) {
1574 		sc->sc_floods++;
1575 		if (sc->sc_errors++ == 0)
1576 			callout_reset(&sc->sc_diag_callout, 60 * hz,
1577 			    plcomdiag, sc);
1578 	}
1579 
1580 	while (cc) {
1581 		code = get[0];
1582 		rsr = get[1];
1583 		if (ISSET(rsr, RSR_OE | RSR_BE | RSR_FE | RSR_PE)) {
1584 			if (ISSET(rsr, RSR_OE)) {
1585 				sc->sc_overflows++;
1586 				if (sc->sc_errors++ == 0)
1587 					callout_reset(&sc->sc_diag_callout,
1588 					    60 * hz, plcomdiag, sc);
1589 			}
1590 			if (ISSET(rsr, RSR_BE | RSR_FE))
1591 				SET(code, TTY_FE);
1592 			if (ISSET(rsr, RSR_PE))
1593 				SET(code, TTY_PE);
1594 		}
1595 		if ((*rint)(code, tp) == -1) {
1596 			/*
1597 			 * The line discipline's buffer is out of space.
1598 			 */
1599 			if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1600 				/*
1601 				 * We're either not using flow control, or the
1602 				 * line discipline didn't tell us to block for
1603 				 * some reason.  Either way, we have no way to
1604 				 * know when there's more space available, so
1605 				 * just drop the rest of the data.
1606 				 */
1607 				get += cc << 1;
1608 				if (get >= end)
1609 					get -= plcom_rbuf_size << 1;
1610 				cc = 0;
1611 			} else {
1612 				/*
1613 				 * Don't schedule any more receive processing
1614 				 * until the line discipline tells us there's
1615 				 * space available (through plcomhwiflow()).
1616 				 * Leave the rest of the data in the input
1617 				 * buffer.
1618 				 */
1619 				SET(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1620 			}
1621 			break;
1622 		}
1623 		get += 2;
1624 		if (get >= end)
1625 			get = sc->sc_rbuf;
1626 		cc--;
1627 	}
1628 
1629 	if (cc != scc) {
1630 		sc->sc_rbget = get;
1631 		s = splserial();
1632 		PLCOM_LOCK(sc);
1633 
1634 		cc = sc->sc_rbavail += scc - cc;
1635 		/* Buffers should be ok again, release possible block. */
1636 		if (cc >= sc->sc_r_lowat) {
1637 			if (ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
1638 				CLR(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
1639 				SET(sc->sc_cr, CR_RIE | CR_RTIE);
1640 				bus_space_write_1(sc->sc_iot, sc->sc_ioh, plcom_cr, sc->sc_cr);
1641 			}
1642 			if (ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED)) {
1643 				CLR(sc->sc_rx_flags, RX_IBUF_BLOCKED);
1644 				plcom_hwiflow(sc);
1645 			}
1646 		}
1647 		PLCOM_UNLOCK(sc);
1648 		splx(s);
1649 	}
1650 }
1651 
1652 integrate void
1653 plcom_txsoft(struct plcom_softc *sc, struct tty *tp)
1654 {
1655 
1656 	CLR(tp->t_state, TS_BUSY);
1657 	if (ISSET(tp->t_state, TS_FLUSH))
1658 		CLR(tp->t_state, TS_FLUSH);
1659 	else
1660 		ndflush(&tp->t_outq, (int)(sc->sc_tba - tp->t_outq.c_cf));
1661 	(*tp->t_linesw->l_start)(tp);
1662 }
1663 
1664 integrate void
1665 plcom_stsoft(struct plcom_softc *sc, struct tty *tp)
1666 {
1667 	u_char msr, delta;
1668 	int s;
1669 
1670 	s = splserial();
1671 	PLCOM_LOCK(sc);
1672 	msr = sc->sc_msr;
1673 	delta = sc->sc_msr_delta;
1674 	sc->sc_msr_delta = 0;
1675 	PLCOM_UNLOCK(sc);
1676 	splx(s);
1677 
1678 	if (ISSET(delta, sc->sc_msr_dcd)) {
1679 		/*
1680 		 * Inform the tty layer that carrier detect changed.
1681 		 */
1682 		(void) (*tp->t_linesw->l_modem)(tp, ISSET(msr, MSR_DCD));
1683 	}
1684 
1685 	if (ISSET(delta, sc->sc_msr_cts)) {
1686 		/* Block or unblock output according to flow control. */
1687 		if (ISSET(msr, sc->sc_msr_cts)) {
1688 			sc->sc_tx_stopped = 0;
1689 			(*tp->t_linesw->l_start)(tp);
1690 		} else {
1691 			sc->sc_tx_stopped = 1;
1692 		}
1693 	}
1694 
1695 #ifdef PLCOM_DEBUG
1696 	if (plcom_debug)
1697 		plcomstatus(sc, "plcom_stsoft");
1698 #endif
1699 }
1700 
1701 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
1702 void
1703 plcomsoft(void *arg)
1704 {
1705 	struct plcom_softc *sc = arg;
1706 	struct tty *tp;
1707 
1708 	if (PLCOM_ISALIVE(sc) == 0)
1709 		return;
1710 
1711 	{
1712 #else
1713 void
1714 #ifndef __NO_SOFT_SERIAL_INTERRUPT
1715 plcomsoft(void)
1716 #else
1717 plcomsoft(void *arg)
1718 #endif
1719 {
1720 	struct plcom_softc	*sc;
1721 	struct tty	*tp;
1722 	int	unit;
1723 #ifdef __NO_SOFT_SERIAL_INTERRUPT
1724 	int s;
1725 
1726 	s = splsoftserial();
1727 	plcom_softintr_scheduled = 0;
1728 #endif
1729 
1730 	for (unit = 0; unit < plcom_cd.cd_ndevs; unit++) {
1731 		sc = device_lookup(&plcom_cd, unit);
1732 		if (sc == NULL || !ISSET(sc->sc_hwflags, PLCOM_HW_DEV_OK))
1733 			continue;
1734 
1735 		if (PLCOM_ISALIVE(sc) == 0)
1736 			continue;
1737 
1738 		tp = sc->sc_tty;
1739 		if (tp == NULL)
1740 			continue;
1741 		if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0)
1742 			continue;
1743 #endif
1744 		tp = sc->sc_tty;
1745 
1746 		if (sc->sc_rx_ready) {
1747 			sc->sc_rx_ready = 0;
1748 			plcom_rxsoft(sc, tp);
1749 		}
1750 
1751 		if (sc->sc_st_check) {
1752 			sc->sc_st_check = 0;
1753 			plcom_stsoft(sc, tp);
1754 		}
1755 
1756 		if (sc->sc_tx_done) {
1757 			sc->sc_tx_done = 0;
1758 			plcom_txsoft(sc, tp);
1759 		}
1760 	}
1761 
1762 #ifndef __HAVE_GENERIC_SOFT_INTERRUPTS
1763 #ifdef __NO_SOFT_SERIAL_INTERRUPT
1764 	splx(s);
1765 #endif
1766 #endif
1767 }
1768 
1769 #ifdef __ALIGN_BRACKET_LEVEL_FOR_CTAGS
1770 	/* there has got to be a better way to do plcomsoft() */
1771 }}
1772 #endif
1773 
1774 int
1775 plcomintr(void *arg)
1776 {
1777 	struct plcom_softc *sc = arg;
1778 	bus_space_tag_t iot = sc->sc_iot;
1779 	bus_space_handle_t ioh = sc->sc_ioh;
1780 	u_char *put, *end;
1781 	u_int cc;
1782 	u_char rsr, iir;
1783 
1784 	if (PLCOM_ISALIVE(sc) == 0)
1785 		return 0;
1786 
1787 	PLCOM_LOCK(sc);
1788 	iir = bus_space_read_1(iot, ioh, plcom_iir);
1789 	if (! ISSET(iir, IIR_IMASK)) {
1790 		PLCOM_UNLOCK(sc);
1791 		return 0;
1792 	}
1793 
1794 	end = sc->sc_ebuf;
1795 	put = sc->sc_rbput;
1796 	cc = sc->sc_rbavail;
1797 
1798 	do {
1799 		u_char	msr, delta, fr;
1800 
1801 		fr = bus_space_read_1(iot, ioh, plcom_fr);
1802 
1803 		if (!ISSET(fr, FR_RXFE) &&
1804 		    !ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
1805 			while (cc > 0) {
1806 				int cn_trapped = 0;
1807 				put[0] = bus_space_read_1(iot, ioh,
1808 				    plcom_dr);
1809 				rsr = bus_space_read_1(iot, ioh, plcom_rsr);
1810 				/* Clear any error status.  */
1811 				if (ISSET(rsr,
1812 				    (RSR_BE | RSR_OE | RSR_PE | RSR_FE)))
1813 					bus_space_write_1(iot, ioh, plcom_ecr,
1814 					    0);
1815 				if (ISSET(rsr, RSR_BE)) {
1816 					cn_trapped = 0;
1817 					cn_check_magic(sc->sc_tty->t_dev,
1818 					    CNC_BREAK, plcom_cnm_state);
1819 					if (cn_trapped)
1820 						continue;
1821 #if defined(KGDB)
1822 					if (ISSET(sc->sc_hwflags,
1823 					    PLCOM_HW_KGDB)) {
1824 						kgdb_connect(1);
1825 						continue;
1826 					}
1827 #endif
1828 				}
1829 
1830 				put[1] = rsr;
1831 				cn_trapped = 0;
1832 				cn_check_magic(sc->sc_tty->t_dev,
1833 					       put[0], plcom_cnm_state);
1834 				if (cn_trapped) {
1835 					fr = bus_space_read_1(iot, ioh,
1836 					    plcom_fr);
1837 					if (ISSET(fr, FR_RXFE))
1838 						break;
1839 
1840 					continue;
1841 				}
1842 				put += 2;
1843 				if (put >= end)
1844 					put = sc->sc_rbuf;
1845 				cc--;
1846 
1847 				fr = bus_space_read_1(iot, ioh, plcom_fr);
1848 				if (ISSET(fr, FR_RXFE))
1849 					break;
1850 			}
1851 
1852 			/*
1853 			 * Current string of incoming characters ended because
1854 			 * no more data was available or we ran out of space.
1855 			 * Schedule a receive event if any data was received.
1856 			 * If we're out of space, turn off receive interrupts.
1857 			 */
1858 			sc->sc_rbput = put;
1859 			sc->sc_rbavail = cc;
1860 			if (!ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED))
1861 				sc->sc_rx_ready = 1;
1862 
1863 			/*
1864 			 * See if we are in danger of overflowing a buffer. If
1865 			 * so, use hardware flow control to ease the pressure.
1866 			 */
1867 			if (!ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED) &&
1868 			    cc < sc->sc_r_hiwat) {
1869 				SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
1870 				plcom_hwiflow(sc);
1871 			}
1872 
1873 			/*
1874 			 * If we're out of space, disable receive interrupts
1875 			 * until the queue has drained a bit.
1876 			 */
1877 			if (!cc) {
1878 				SET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
1879 				CLR(sc->sc_cr, CR_RIE | CR_RTIE);
1880 				bus_space_write_1(iot, ioh, plcom_cr,
1881 				    sc->sc_cr);
1882 			}
1883 		} else {
1884 			if (ISSET(iir, IIR_RIS)) {
1885 				bus_space_write_1(iot, ioh, plcom_cr, 0);
1886 				delay(10);
1887 				bus_space_write_1(iot, ioh, plcom_cr,
1888 				    sc->sc_cr);
1889 				continue;
1890 			}
1891 		}
1892 
1893 		msr = bus_space_read_1(iot, ioh, plcom_fr);
1894 		delta = msr ^ sc->sc_msr;
1895 		sc->sc_msr = msr;
1896 		/* Clear any pending modem status interrupt.  */
1897 		if (iir & IIR_MIS)
1898 			bus_space_write_1(iot, ioh, plcom_icr, 0);
1899 		/*
1900 		 * Pulse-per-second (PSS) signals on edge of DCD?
1901 		 * Process these even if line discipline is ignoring DCD.
1902 		 */
1903 		if (delta & sc->sc_ppsmask) {
1904 			struct timeval tv;
1905 		    	if ((msr & sc->sc_ppsmask) == sc->sc_ppsassert) {
1906 				/* XXX nanotime() */
1907 				microtime(&tv);
1908 				TIMEVAL_TO_TIMESPEC(&tv,
1909 				    &sc->ppsinfo.assert_timestamp);
1910 				if (sc->ppsparam.mode & PPS_OFFSETASSERT) {
1911 					timespecadd(&sc->ppsinfo.assert_timestamp,
1912 					    &sc->ppsparam.assert_offset,
1913 						    &sc->ppsinfo.assert_timestamp);
1914 				}
1915 
1916 #ifdef PPS_SYNC
1917 				if (sc->ppsparam.mode & PPS_HARDPPSONASSERT)
1918 					hardpps(&tv, tv.tv_usec);
1919 #endif
1920 				sc->ppsinfo.assert_sequence++;
1921 				sc->ppsinfo.current_mode = sc->ppsparam.mode;
1922 
1923 			} else if ((msr & sc->sc_ppsmask) == sc->sc_ppsclear) {
1924 				/* XXX nanotime() */
1925 				microtime(&tv);
1926 				TIMEVAL_TO_TIMESPEC(&tv,
1927 				    &sc->ppsinfo.clear_timestamp);
1928 				if (sc->ppsparam.mode & PPS_OFFSETCLEAR) {
1929 					timespecadd(&sc->ppsinfo.clear_timestamp,
1930 					    &sc->ppsparam.clear_offset,
1931 					    &sc->ppsinfo.clear_timestamp);
1932 				}
1933 
1934 #ifdef PPS_SYNC
1935 				if (sc->ppsparam.mode & PPS_HARDPPSONCLEAR)
1936 					hardpps(&tv, tv.tv_usec);
1937 #endif
1938 				sc->ppsinfo.clear_sequence++;
1939 				sc->ppsinfo.current_mode = sc->ppsparam.mode;
1940 			}
1941 		}
1942 
1943 		/*
1944 		 * Process normal status changes
1945 		 */
1946 		if (ISSET(delta, sc->sc_msr_mask)) {
1947 			SET(sc->sc_msr_delta, delta);
1948 
1949 			/*
1950 			 * Stop output immediately if we lose the output
1951 			 * flow control signal or carrier detect.
1952 			 */
1953 			if (ISSET(~msr, sc->sc_msr_mask)) {
1954 				sc->sc_tbc = 0;
1955 				sc->sc_heldtbc = 0;
1956 #ifdef PLCOM_DEBUG
1957 				if (plcom_debug)
1958 					plcomstatus(sc, "plcomintr  ");
1959 #endif
1960 			}
1961 
1962 			sc->sc_st_check = 1;
1963 		}
1964 
1965 		/*
1966 		 * Done handling any receive interrupts. See if data
1967 		 * can be * transmitted as well. Schedule tx done
1968 		 * event if no data left * and tty was marked busy.
1969 		 */
1970 		if (ISSET(iir, IIR_TIS)) {
1971 			/*
1972 			 * If we've delayed a parameter change, do it
1973 			 * now, and restart * output.
1974 			 */
1975 			if (sc->sc_heldchange) {
1976 				plcom_loadchannelregs(sc);
1977 				sc->sc_heldchange = 0;
1978 				sc->sc_tbc = sc->sc_heldtbc;
1979 				sc->sc_heldtbc = 0;
1980 			}
1981 
1982 			/*
1983 			 * Output the next chunk of the contiguous
1984 			 * buffer, if any.
1985 			 */
1986 			if (sc->sc_tbc > 0) {
1987 				int n;
1988 
1989 				n = sc->sc_tbc;
1990 				if (n > sc->sc_fifolen)
1991 					n = sc->sc_fifolen;
1992 				bus_space_write_multi_1(iot, ioh, plcom_dr,
1993 				    sc->sc_tba, n);
1994 				sc->sc_tbc -= n;
1995 				sc->sc_tba += n;
1996 			} else {
1997 				/*
1998 				 * Disable transmit plcompletion
1999 				 * interrupts if necessary.
2000 				 */
2001 				if (ISSET(sc->sc_cr, CR_TIE)) {
2002 					CLR(sc->sc_cr, CR_TIE);
2003 					bus_space_write_1(iot, ioh, plcom_cr,
2004 					    sc->sc_cr);
2005 				}
2006 				if (sc->sc_tx_busy) {
2007 					sc->sc_tx_busy = 0;
2008 					sc->sc_tx_done = 1;
2009 				}
2010 			}
2011 		}
2012 	} while (ISSET((iir = bus_space_read_1(iot, ioh, plcom_iir)),
2013 	    IIR_IMASK));
2014 
2015 	PLCOM_UNLOCK(sc);
2016 
2017 	/* Wake up the poller. */
2018 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
2019 	softintr_schedule(sc->sc_si);
2020 #else
2021 #ifndef __NO_SOFT_SERIAL_INTERRUPT
2022 	setsoftserial();
2023 #else
2024 	if (!plcom_softintr_scheduled) {
2025 		plcom_softintr_scheduled = 1;
2026 		callout_reset(&plcomsoft_callout, 1, plcomsoft, NULL);
2027 	}
2028 #endif
2029 #endif
2030 
2031 #if NRND > 0 && defined(RND_COM)
2032 	rnd_add_uint32(&sc->rnd_source, iir | rsr);
2033 #endif
2034 
2035 	return 1;
2036 }
2037 
2038 /*
2039  * The following functions are polled getc and putc routines, shared
2040  * by the console and kgdb glue.
2041  *
2042  * The read-ahead code is so that you can detect pending in-band
2043  * cn_magic in polled mode while doing output rather than having to
2044  * wait until the kernel decides it needs input.
2045  */
2046 
2047 #define MAX_READAHEAD	20
2048 static int plcom_readahead[MAX_READAHEAD];
2049 static int plcom_readaheadcount = 0;
2050 
2051 int
2052 plcom_common_getc(dev_t dev, bus_space_tag_t iot, bus_space_handle_t ioh)
2053 {
2054 	int s = splserial();
2055 	u_char stat, c;
2056 
2057 	/* got a character from reading things earlier */
2058 	if (plcom_readaheadcount > 0) {
2059 		int i;
2060 
2061 		c = plcom_readahead[0];
2062 		for (i = 1; i < plcom_readaheadcount; i++) {
2063 			plcom_readahead[i-1] = plcom_readahead[i];
2064 		}
2065 		plcom_readaheadcount--;
2066 		splx(s);
2067 		return c;
2068 	}
2069 
2070 	/* block until a character becomes available */
2071 	while (ISSET(stat = bus_space_read_1(iot, ioh, plcom_fr), FR_RXFE))
2072 		;
2073 
2074 	c = bus_space_read_1(iot, ioh, plcom_dr);
2075 	stat = bus_space_read_1(iot, ioh, plcom_iir);
2076 	{
2077 		int cn_trapped = 0; /* unused */
2078 #ifdef DDB
2079 		extern int db_active;
2080 		if (!db_active)
2081 #endif
2082 			cn_check_magic(dev, c, plcom_cnm_state);
2083 	}
2084 	splx(s);
2085 	return c;
2086 }
2087 
2088 void
2089 plcom_common_putc(dev_t dev, bus_space_tag_t iot, bus_space_handle_t ioh,
2090     int c)
2091 {
2092 	int s = splserial();
2093 	int timo;
2094 
2095 	int cin, stat;
2096 	if (plcom_readaheadcount < MAX_READAHEAD
2097 	     && !ISSET(stat = bus_space_read_1(iot, ioh, plcom_fr), FR_RXFE)) {
2098 		int cn_trapped = 0;
2099 		cin = bus_space_read_1(iot, ioh, plcom_dr);
2100 		stat = bus_space_read_1(iot, ioh, plcom_iir);
2101 		cn_check_magic(dev, cin, plcom_cnm_state);
2102 		plcom_readahead[plcom_readaheadcount++] = cin;
2103 	}
2104 
2105 	/* wait for any pending transmission to finish */
2106 	timo = 150000;
2107 	while (!ISSET(bus_space_read_1(iot, ioh, plcom_fr), FR_TXFE) && --timo)
2108 		continue;
2109 
2110 	bus_space_write_1(iot, ioh, plcom_dr, c);
2111 	PLCOM_BARRIER(iot, ioh, BR | BW);
2112 
2113 	/* wait for this transmission to complete */
2114 	timo = 1500000;
2115 	while (!ISSET(bus_space_read_1(iot, ioh, plcom_fr), FR_TXFE) && --timo)
2116 		continue;
2117 
2118 	splx(s);
2119 }
2120 
2121 /*
2122  * Initialize UART for use as console or KGDB line.
2123  */
2124 int
2125 plcominit(bus_space_tag_t iot, bus_addr_t iobase, int rate, int frequency,
2126     tcflag_t cflag, bus_space_handle_t *iohp)
2127 {
2128 	bus_space_handle_t ioh;
2129 
2130 	if (bus_space_map(iot, iobase, PLCOM_UART_SIZE, 0, &ioh))
2131 		return ENOMEM; /* ??? */
2132 
2133 	rate = plcomspeed(rate, frequency);
2134 	bus_space_write_1(iot, ioh, plcom_cr, 0);
2135 	bus_space_write_1(iot, ioh, plcom_dlbl, rate);
2136 	bus_space_write_1(iot, ioh, plcom_dlbh, rate >> 8);
2137 	bus_space_write_1(iot, ioh, plcom_lcr, cflag2lcr(cflag) | LCR_FEN);
2138 	bus_space_write_1(iot, ioh, plcom_cr, CR_UARTEN);
2139 
2140 #if 0
2141 	/* Ought to do something like this, but we have no sc to
2142 	   dereference. */
2143 	/* XXX device_unit() abuse */
2144 	sc->sc_set_mcr(sc->sc_set_mcr_arg, device_unit(&sc->sc_dev),
2145 	    MCR_DTR | MCR_RTS);
2146 #endif
2147 
2148 	*iohp = ioh;
2149 	return 0;
2150 }
2151 
2152 /*
2153  * Following are all routines needed for PLCOM to act as console
2154  */
2155 struct consdev plcomcons = {
2156 	NULL, NULL, plcomcngetc, plcomcnputc, plcomcnpollc, NULL,
2157 	NULL, NULL, NODEV, CN_NORMAL
2158 };
2159 
2160 
2161 int
2162 plcomcnattach(bus_space_tag_t iot, bus_addr_t iobase, int rate, int frequency,
2163     tcflag_t cflag, int unit)
2164 {
2165 	int res;
2166 
2167 	res = plcominit(iot, iobase, rate, frequency, cflag, &plcomconsioh);
2168 	if (res)
2169 		return res;
2170 
2171 	cn_tab = &plcomcons;
2172 	cn_init_magic(&plcom_cnm_state);
2173 	cn_set_magic("\047\001"); /* default magic is BREAK */
2174 
2175 	plcomconstag = iot;
2176 	plcomconsunit = unit;
2177 	plcomconsrate = rate;
2178 	plcomconscflag = cflag;
2179 
2180 	return 0;
2181 }
2182 
2183 void
2184 plcomcndetach(void)
2185 {
2186 	bus_space_unmap(plcomconstag, plcomconsioh, PLCOM_UART_SIZE);
2187 	plcomconstag = NULL;
2188 
2189 	cn_tab = NULL;
2190 }
2191 
2192 int
2193 plcomcngetc(dev_t dev)
2194 {
2195 	return plcom_common_getc(dev, plcomconstag, plcomconsioh);
2196 }
2197 
2198 /*
2199  * Console kernel output character routine.
2200  */
2201 void
2202 plcomcnputc(dev_t dev, int c)
2203 {
2204 	plcom_common_putc(dev, plcomconstag, plcomconsioh, c);
2205 }
2206 
2207 void
2208 plcomcnpollc(dev_t dev, int on)
2209 {
2210 
2211 }
2212 
2213 #ifdef KGDB
2214 int
2215 plcom_kgdb_attach(bus_space_tag_t iot, bus_addr_t iobase, int rate,
2216    int frequency, tcflag_t cflag, int unit)
2217 {
2218 	int res;
2219 
2220 	if (iot == plcomconstag && iobase == plcomconsunit)
2221 		return EBUSY; /* cannot share with console */
2222 
2223 	res = plcominit(iot, iobase, rate, frequency, cflag, &plcom_kgdb_ioh);
2224 	if (res)
2225 		return res;
2226 
2227 	kgdb_attach(plcom_kgdb_getc, plcom_kgdb_putc, NULL);
2228 	kgdb_dev = 123; /* unneeded, only to satisfy some tests */
2229 
2230 	plcom_kgdb_iot = iot;
2231 	plcom_kgdb_unit = unit;
2232 
2233 	return 0;
2234 }
2235 
2236 /* ARGSUSED */
2237 int
2238 plcom_kgdb_getc(void *arg)
2239 {
2240 	return plcom_common_getc(NODEV, plcom_kgdb_iot, plcom_kgdb_ioh);
2241 }
2242 
2243 /* ARGSUSED */
2244 void
2245 plcom_kgdb_putc(void *arg, int c)
2246 {
2247 	plcom_common_putc(NODEV, plcom_kgdb_iot, plcom_kgdb_ioh, c);
2248 }
2249 #endif /* KGDB */
2250 
2251 /* helper function to identify the plcom ports used by
2252  console or KGDB (and not yet autoconf attached) */
2253 int
2254 plcom_is_console(bus_space_tag_t iot, int unit,
2255     bus_space_handle_t *ioh)
2256 {
2257 	bus_space_handle_t help;
2258 
2259 	if (!plcomconsattached &&
2260 	    iot == plcomconstag && unit == plcomconsunit)
2261 		help = plcomconsioh;
2262 #ifdef KGDB
2263 	else if (!plcom_kgdb_attached &&
2264 	    iot == plcom_kgdb_iot && unit == plcom_kgdb_unit)
2265 		help = plcom_kgdb_ioh;
2266 #endif
2267 	else
2268 		return 0;
2269 
2270 	if (ioh)
2271 		*ioh = help;
2272 	return 1;
2273 }
2274