xref: /netbsd-src/sys/arch/evbarm/dev/plcom.c (revision 8b0f9554ff8762542c4defc4f70e1eb76fb508fa)
1 /*	$NetBSD: plcom.c,v 1.24 2007/11/19 18:51:39 ad 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 1.24 2007/11/19 18:51:39 ad 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 void 	plcomsoft	(void *);
195 integrate void plcom_rxsoft	(struct plcom_softc *, struct tty *);
196 integrate void plcom_txsoft	(struct plcom_softc *, struct tty *);
197 integrate void plcom_stsoft	(struct plcom_softc *, struct tty *);
198 integrate void plcom_schedrx	(struct plcom_softc *);
199 void	plcomdiag		(void *);
200 
201 extern struct cfdriver plcom_cd;
202 
203 const struct cdevsw plcom_cdevsw = {
204 	plcomopen, plcomclose, plcomread, plcomwrite, plcomioctl,
205 	plcomstop, plcomtty, plcompoll, nommap, ttykqfilter, D_TTY
206 };
207 
208 /*
209  * Make this an option variable one can patch.
210  * But be warned:  this must be a power of 2!
211  */
212 u_int plcom_rbuf_size = PLCOM_RING_SIZE;
213 
214 /* Stop input when 3/4 of the ring is full; restart when only 1/4 is full. */
215 u_int plcom_rbuf_hiwat = (PLCOM_RING_SIZE * 1) / 4;
216 u_int plcom_rbuf_lowat = (PLCOM_RING_SIZE * 3) / 4;
217 
218 static int	plcomconsunit = -1;
219 static bus_space_tag_t plcomconstag;
220 static bus_space_handle_t plcomconsioh;
221 static int	plcomconsattached;
222 static int plcomconsrate;
223 static tcflag_t plcomconscflag;
224 static struct cnm_state plcom_cnm_state;
225 
226 static int ppscap =
227 	PPS_TSFMT_TSPEC |
228 	PPS_CAPTUREASSERT |
229 	PPS_CAPTURECLEAR |
230 #ifdef  PPS_SYNC
231 	PPS_HARDPPSONASSERT | PPS_HARDPPSONCLEAR |
232 #endif	/* PPS_SYNC */
233 	PPS_OFFSETASSERT | PPS_OFFSETCLEAR;
234 
235 #ifdef KGDB
236 #include <sys/kgdb.h>
237 
238 static int plcom_kgdb_unit;
239 static bus_space_tag_t plcom_kgdb_iot;
240 static bus_space_handle_t plcom_kgdb_ioh;
241 static int plcom_kgdb_attached;
242 
243 int	plcom_kgdb_getc (void *);
244 void	plcom_kgdb_putc (void *, int);
245 #endif /* KGDB */
246 
247 #define	PLCOMUNIT_MASK	0x7ffff
248 #define	PLCOMDIALOUT_MASK	0x80000
249 
250 #define	PLCOMUNIT(x)	(minor(x) & PLCOMUNIT_MASK)
251 #define	PLCOMDIALOUT(x)	(minor(x) & PLCOMDIALOUT_MASK)
252 
253 #define	PLCOM_ISALIVE(sc)	((sc)->enabled != 0 && \
254 				 device_is_active(&(sc)->sc_dev))
255 
256 #define	BR	BUS_SPACE_BARRIER_READ
257 #define	BW	BUS_SPACE_BARRIER_WRITE
258 #define PLCOM_BARRIER(t, h, f) bus_space_barrier((t), (h), 0, PLCOM_UART_SIZE, (f))
259 
260 #define PLCOM_LOCK(sc) simple_lock(&(sc)->sc_lock)
261 #define PLCOM_UNLOCK(sc) simple_unlock(&(sc)->sc_lock)
262 
263 int
264 plcomspeed(long speed, long frequency)
265 {
266 #define	divrnd(n, q)	(((n)*2/(q)+1)/2)	/* divide and round off */
267 
268 	int x, err;
269 
270 #if 0
271 	if (speed == 0)
272 		return 0;
273 #endif
274 	if (speed <= 0)
275 		return -1;
276 	x = divrnd(frequency / 16, speed);
277 	if (x <= 0)
278 		return -1;
279 	err = divrnd(((quad_t)frequency) * 1000 / 16, speed * x) - 1000;
280 	if (err < 0)
281 		err = -err;
282 	if (err > PLCOM_TOLERANCE)
283 		return -1;
284 	return x;
285 
286 #undef	divrnd
287 }
288 
289 #ifdef PLCOM_DEBUG
290 int	plcom_debug = 0;
291 
292 void plcomstatus (struct plcom_softc *, char *);
293 void
294 plcomstatus(struct plcom_softc *sc, char *str)
295 {
296 	struct tty *tp = sc->sc_tty;
297 
298 	printf("%s: %s %sclocal  %sdcd %sts_carr_on %sdtr %stx_stopped\n",
299 	    sc->sc_dev.dv_xname, str,
300 	    ISSET(tp->t_cflag, CLOCAL) ? "+" : "-",
301 	    ISSET(sc->sc_msr, MSR_DCD) ? "+" : "-",
302 	    ISSET(tp->t_state, TS_CARR_ON) ? "+" : "-",
303 	    ISSET(sc->sc_mcr, MCR_DTR) ? "+" : "-",
304 	    sc->sc_tx_stopped ? "+" : "-");
305 
306 	printf("%s: %s %scrtscts %scts %sts_ttstop  %srts %xrx_flags\n",
307 	    sc->sc_dev.dv_xname, str,
308 	    ISSET(tp->t_cflag, CRTSCTS) ? "+" : "-",
309 	    ISSET(sc->sc_msr, MSR_CTS) ? "+" : "-",
310 	    ISSET(tp->t_state, TS_TTSTOP) ? "+" : "-",
311 	    ISSET(sc->sc_mcr, MCR_RTS) ? "+" : "-",
312 	    sc->sc_rx_flags);
313 }
314 #endif
315 
316 int
317 plcomprobe1(bus_space_tag_t iot, bus_space_handle_t ioh)
318 {
319 	int data;
320 
321 	/* Disable the UART.  */
322 	bus_space_write_1(iot, ioh, plcom_cr, 0);
323 	/* Make sure the FIFO is off.  */
324 	bus_space_write_1(iot, ioh, plcom_lcr, LCR_8BITS);
325 	/* Disable interrupts.  */
326 	bus_space_write_1(iot, ioh, plcom_iir, 0);
327 
328 	/* Make sure we swallow anything in the receiving register.  */
329 	data = bus_space_read_1(iot, ioh, plcom_dr);
330 
331 	if (bus_space_read_1(iot, ioh, plcom_lcr) != LCR_8BITS)
332 		return 0;
333 
334 	data = bus_space_read_1(iot, ioh, plcom_fr) & (FR_RXFF | FR_RXFE);
335 
336 	if (data != FR_RXFE)
337 		return 0;
338 
339 	return 1;
340 }
341 
342 static void
343 plcom_enable_debugport(struct plcom_softc *sc)
344 {
345 	int s;
346 
347 	/* Turn on line break interrupt, set carrier. */
348 	s = splserial();
349 	PLCOM_LOCK(sc);
350 	sc->sc_cr = CR_RIE | CR_RTIE | CR_UARTEN;
351 	bus_space_write_1(sc->sc_iot, sc->sc_ioh, plcom_cr, sc->sc_cr);
352 	SET(sc->sc_mcr, MCR_DTR | MCR_RTS);
353 	/* XXX device_unit() abuse */
354 	sc->sc_set_mcr(sc->sc_set_mcr_arg, device_unit(&sc->sc_dev),
355 	    sc->sc_mcr);
356 	PLCOM_UNLOCK(sc);
357 	splx(s);
358 }
359 
360 void
361 plcom_attach_subr(struct plcom_softc *sc)
362 {
363 	int unit = sc->sc_iounit;
364 	bus_space_tag_t iot = sc->sc_iot;
365 	bus_space_handle_t ioh = sc->sc_ioh;
366 	struct tty *tp;
367 
368 	callout_init(&sc->sc_diag_callout, 0);
369 	simple_lock_init(&sc->sc_lock);
370 
371 	/* Disable interrupts before configuring the device. */
372 	sc->sc_cr = 0;
373 
374 	if (plcomconstag && unit == plcomconsunit) {
375 		plcomconsattached = 1;
376 
377 		plcomconstag = iot;
378 		plcomconsioh = ioh;
379 
380 		/* Make sure the console is always "hardwired". */
381 		delay(1000);			/* wait for output to finish */
382 		SET(sc->sc_hwflags, PLCOM_HW_CONSOLE);
383 		SET(sc->sc_swflags, TIOCFLAG_SOFTCAR);
384 		/* Must re-enable the console immediately, or we will
385 		   hang when trying to print.  */
386 		sc->sc_cr = CR_UARTEN;
387 	}
388 
389 	bus_space_write_1(iot, ioh, plcom_cr, sc->sc_cr);
390 
391 	/* The PL010 has a 16-byte fifo, but the tx interrupt triggers when
392 	   there is space for 8 more bytes.  */
393 	sc->sc_fifolen = 8;
394 	printf("\n");
395 
396 	if (ISSET(sc->sc_hwflags, PLCOM_HW_TXFIFO_DISABLE)) {
397 		sc->sc_fifolen = 1;
398 		printf("%s: txfifo disabled\n", sc->sc_dev.dv_xname);
399 	}
400 
401 	if (sc->sc_fifolen > 1)
402 		SET(sc->sc_hwflags, PLCOM_HW_FIFO);
403 
404 	tp = ttymalloc();
405 	tp->t_oproc = plcomstart;
406 	tp->t_param = plcomparam;
407 	tp->t_hwiflow = plcomhwiflow;
408 
409 	sc->sc_tty = tp;
410 	sc->sc_rbuf = malloc(plcom_rbuf_size << 1, M_DEVBUF, M_NOWAIT);
411 	sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
412 	sc->sc_rbavail = plcom_rbuf_size;
413 	if (sc->sc_rbuf == NULL) {
414 		printf("%s: unable to allocate ring buffer\n",
415 		    sc->sc_dev.dv_xname);
416 		return;
417 	}
418 	sc->sc_ebuf = sc->sc_rbuf + (plcom_rbuf_size << 1);
419 
420 	tty_attach(tp);
421 
422 	if (ISSET(sc->sc_hwflags, PLCOM_HW_CONSOLE)) {
423 		int maj;
424 
425 		/* locate the major number */
426 		maj = cdevsw_lookup_major(&plcom_cdevsw);
427 
428 		cn_tab->cn_dev = makedev(maj, device_unit(&sc->sc_dev));
429 
430 		printf("%s: console\n", sc->sc_dev.dv_xname);
431 	}
432 
433 #ifdef KGDB
434 	/*
435 	 * Allow kgdb to "take over" this port.  If this is
436 	 * the kgdb device, it has exclusive use.
437 	 */
438 	if (iot == plcom_kgdb_iot && unit == plcom_kgdb_unit) {
439 		plcom_kgdb_attached = 1;
440 
441 		SET(sc->sc_hwflags, PLCOM_HW_KGDB);
442 		printf("%s: kgdb\n", sc->sc_dev.dv_xname);
443 	}
444 #endif
445 
446 	sc->sc_si = softintr_establish(IPL_SOFTSERIAL, plcomsoft, sc);
447 
448 #if NRND > 0 && defined(RND_COM)
449 	rnd_attach_source(&sc->rnd_source, sc->sc_dev.dv_xname,
450 			  RND_TYPE_TTY, 0);
451 #endif
452 
453 	/* if there are no enable/disable functions, assume the device
454 	   is always enabled */
455 	if (!sc->enable)
456 		sc->enabled = 1;
457 
458 	plcom_config(sc);
459 
460 	SET(sc->sc_hwflags, PLCOM_HW_DEV_OK);
461 }
462 
463 void
464 plcom_config(struct plcom_softc *sc)
465 {
466 	bus_space_tag_t iot = sc->sc_iot;
467 	bus_space_handle_t ioh = sc->sc_ioh;
468 
469 	/* Disable interrupts before configuring the device. */
470 	sc->sc_cr = 0;
471 	bus_space_write_1(iot, ioh, plcom_cr, sc->sc_cr);
472 
473 	if (ISSET(sc->sc_hwflags, PLCOM_HW_CONSOLE|PLCOM_HW_KGDB))
474 		plcom_enable_debugport(sc);
475 }
476 
477 int
478 plcom_detach(self, flags)
479 	struct device *self;
480 	int flags;
481 {
482 	struct plcom_softc *sc = (struct plcom_softc *)self;
483 	int maj, mn;
484 
485 	/* locate the major number */
486 	maj = cdevsw_lookup_major(&plcom_cdevsw);
487 
488 	/* Nuke the vnodes for any open instances. */
489 	mn = device_unit(self);
490 	vdevgone(maj, mn, mn, VCHR);
491 
492 	mn |= PLCOMDIALOUT_MASK;
493 	vdevgone(maj, mn, mn, VCHR);
494 
495 	/* Free the receive buffer. */
496 	free(sc->sc_rbuf, M_DEVBUF);
497 
498 	/* Detach and free the tty. */
499 	tty_detach(sc->sc_tty);
500 	ttyfree(sc->sc_tty);
501 
502 	/* Unhook the soft interrupt handler. */
503 	softintr_disestablish(sc->sc_si);
504 
505 #if NRND > 0 && defined(RND_COM)
506 	/* Unhook the entropy source. */
507 	rnd_detach_source(&sc->rnd_source);
508 #endif
509 
510 	return 0;
511 }
512 
513 int
514 plcom_activate(struct device *self, enum devact act)
515 {
516 	struct plcom_softc *sc = (struct plcom_softc *)self;
517 	int s, rv = 0;
518 
519 	s = splserial();
520 	PLCOM_LOCK(sc);
521 	switch (act) {
522 	case DVACT_ACTIVATE:
523 		rv = EOPNOTSUPP;
524 		break;
525 
526 	case DVACT_DEACTIVATE:
527 		if (sc->sc_hwflags & (PLCOM_HW_CONSOLE|PLCOM_HW_KGDB)) {
528 			rv = EBUSY;
529 			break;
530 		}
531 
532 		if (sc->disable != NULL && sc->enabled != 0) {
533 			(*sc->disable)(sc);
534 			sc->enabled = 0;
535 		}
536 		break;
537 	}
538 
539 	PLCOM_UNLOCK(sc);
540 	splx(s);
541 	return rv;
542 }
543 
544 void
545 plcom_shutdown(struct plcom_softc *sc)
546 {
547 	struct tty *tp = sc->sc_tty;
548 	int s;
549 
550 	s = splserial();
551 	PLCOM_LOCK(sc);
552 
553 	/* If we were asserting flow control, then deassert it. */
554 	SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
555 	plcom_hwiflow(sc);
556 
557 	/* Clear any break condition set with TIOCSBRK. */
558 	plcom_break(sc, 0);
559 
560 	/* Turn off PPS capture on last close. */
561 	sc->sc_ppsmask = 0;
562 	sc->ppsparam.mode = 0;
563 
564 	/*
565 	 * Hang up if necessary.  Wait a bit, so the other side has time to
566 	 * notice even if we immediately open the port again.
567 	 * Avoid tsleeping above splhigh().
568 	 */
569 	if (ISSET(tp->t_cflag, HUPCL)) {
570 		plcom_modem(sc, 0);
571 		PLCOM_UNLOCK(sc);
572 		splx(s);
573 		/* XXX tsleep will only timeout */
574 		(void) tsleep(sc, TTIPRI, ttclos, hz);
575 		s = splserial();
576 		PLCOM_LOCK(sc);
577 	}
578 
579 	/* Turn off interrupts. */
580 	if (ISSET(sc->sc_hwflags, PLCOM_HW_CONSOLE))
581 		/* interrupt on break */
582 		sc->sc_cr = CR_RIE | CR_RTIE | CR_UARTEN;
583 	else
584 		sc->sc_cr = 0;
585 	bus_space_write_1(sc->sc_iot, sc->sc_ioh, plcom_cr, sc->sc_cr);
586 
587 	if (sc->disable) {
588 #ifdef DIAGNOSTIC
589 		if (!sc->enabled)
590 			panic("plcom_shutdown: not enabled?");
591 #endif
592 		(*sc->disable)(sc);
593 		sc->enabled = 0;
594 	}
595 	PLCOM_UNLOCK(sc);
596 	splx(s);
597 }
598 
599 int
600 plcomopen(dev_t dev, int flag, int mode, struct lwp *l)
601 {
602 	struct plcom_softc *sc;
603 	struct tty *tp;
604 	int s, s2;
605 	int error;
606 
607 	sc = device_lookup(&plcom_cd, PLCOMUNIT(dev));
608 	if (sc == NULL || !ISSET(sc->sc_hwflags, PLCOM_HW_DEV_OK) ||
609 		sc->sc_rbuf == NULL)
610 		return ENXIO;
611 
612 	if (!device_is_active(&sc->sc_dev))
613 		return ENXIO;
614 
615 #ifdef KGDB
616 	/*
617 	 * If this is the kgdb port, no other use is permitted.
618 	 */
619 	if (ISSET(sc->sc_hwflags, PLCOM_HW_KGDB))
620 		return EBUSY;
621 #endif
622 
623 	tp = sc->sc_tty;
624 
625 	if (kauth_authorize_device_tty(l->l_cred, KAUTH_DEVICE_TTY_OPEN, tp))
626 		return (EBUSY);
627 
628 	s = spltty();
629 
630 	/*
631 	 * Do the following iff this is a first open.
632 	 */
633 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
634 		struct termios t;
635 
636 		tp->t_dev = dev;
637 
638 		s2 = splserial();
639 		PLCOM_LOCK(sc);
640 
641 		if (sc->enable) {
642 			if ((*sc->enable)(sc)) {
643 				PLCOM_UNLOCK(sc);
644 				splx(s2);
645 				splx(s);
646 				printf("%s: device enable failed\n",
647 				       sc->sc_dev.dv_xname);
648 				return EIO;
649 			}
650 			sc->enabled = 1;
651 			plcom_config(sc);
652 		}
653 
654 		/* Turn on interrupts. */
655 		/* IER_ERXRDY | IER_ERLS | IER_EMSC;  */
656 		sc->sc_cr = CR_RIE | CR_RTIE | CR_MSIE | CR_UARTEN;
657 		bus_space_write_1(sc->sc_iot, sc->sc_ioh, plcom_cr, sc->sc_cr);
658 
659 		/* Fetch the current modem control status, needed later. */
660 		sc->sc_msr = bus_space_read_1(sc->sc_iot, sc->sc_ioh, plcom_fr);
661 
662 		/* Clear PPS capture state on first open. */
663 		sc->sc_ppsmask = 0;
664 		sc->ppsparam.mode = 0;
665 
666 		PLCOM_UNLOCK(sc);
667 		splx(s2);
668 
669 		/*
670 		 * Initialize the termios status to the defaults.  Add in the
671 		 * sticky bits from TIOCSFLAGS.
672 		 */
673 		t.c_ispeed = 0;
674 		if (ISSET(sc->sc_hwflags, PLCOM_HW_CONSOLE)) {
675 			t.c_ospeed = plcomconsrate;
676 			t.c_cflag = plcomconscflag;
677 		} else {
678 			t.c_ospeed = TTYDEF_SPEED;
679 			t.c_cflag = TTYDEF_CFLAG;
680 		}
681 		if (ISSET(sc->sc_swflags, TIOCFLAG_CLOCAL))
682 			SET(t.c_cflag, CLOCAL);
683 		if (ISSET(sc->sc_swflags, TIOCFLAG_CRTSCTS))
684 			SET(t.c_cflag, CRTSCTS);
685 		if (ISSET(sc->sc_swflags, TIOCFLAG_MDMBUF))
686 			SET(t.c_cflag, MDMBUF);
687 		/* Make sure plcomparam() will do something. */
688 		tp->t_ospeed = 0;
689 		(void) plcomparam(tp, &t);
690 		tp->t_iflag = TTYDEF_IFLAG;
691 		tp->t_oflag = TTYDEF_OFLAG;
692 		tp->t_lflag = TTYDEF_LFLAG;
693 		ttychars(tp);
694 		ttsetwater(tp);
695 
696 		s2 = splserial();
697 		PLCOM_LOCK(sc);
698 
699 		/*
700 		 * Turn on DTR.  We must always do this, even if carrier is not
701 		 * present, because otherwise we'd have to use TIOCSDTR
702 		 * immediately after setting CLOCAL, which applications do not
703 		 * expect.  We always assert DTR while the device is open
704 		 * unless explicitly requested to deassert it.
705 		 */
706 		plcom_modem(sc, 1);
707 
708 		/* Clear the input ring, and unblock. */
709 		sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
710 		sc->sc_rbavail = plcom_rbuf_size;
711 		plcom_iflush(sc);
712 		CLR(sc->sc_rx_flags, RX_ANY_BLOCK);
713 		plcom_hwiflow(sc);
714 
715 #ifdef PLCOM_DEBUG
716 		if (plcom_debug)
717 			plcomstatus(sc, "plcomopen  ");
718 #endif
719 
720 		PLCOM_UNLOCK(sc);
721 		splx(s2);
722 	}
723 
724 	splx(s);
725 
726 	error = ttyopen(tp, PLCOMDIALOUT(dev), ISSET(flag, O_NONBLOCK));
727 	if (error)
728 		goto bad;
729 
730 	error = (*tp->t_linesw->l_open)(dev, tp);
731 	if (error)
732 		goto bad;
733 
734 	return 0;
735 
736 bad:
737 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
738 		/*
739 		 * We failed to open the device, and nobody else had it opened.
740 		 * Clean up the state as appropriate.
741 		 */
742 		plcom_shutdown(sc);
743 	}
744 
745 	return error;
746 }
747 
748 int
749 plcomclose(dev_t dev, int flag, int mode, struct lwp *l)
750 {
751 	struct plcom_softc *sc = device_lookup(&plcom_cd, PLCOMUNIT(dev));
752 	struct tty *tp = sc->sc_tty;
753 
754 	/* XXX This is for cons.c. */
755 	if (!ISSET(tp->t_state, TS_ISOPEN))
756 		return 0;
757 
758 	(*tp->t_linesw->l_close)(tp, flag);
759 	ttyclose(tp);
760 
761 	if (PLCOM_ISALIVE(sc) == 0)
762 		return 0;
763 
764 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
765 		/*
766 		 * Although we got a last close, the device may still be in
767 		 * use; e.g. if this was the dialout node, and there are still
768 		 * processes waiting for carrier on the non-dialout node.
769 		 */
770 		plcom_shutdown(sc);
771 	}
772 
773 	return 0;
774 }
775 
776 int
777 plcomread(dev_t dev, struct uio *uio, int flag)
778 {
779 	struct plcom_softc *sc = device_lookup(&plcom_cd, PLCOMUNIT(dev));
780 	struct tty *tp = sc->sc_tty;
781 
782 	if (PLCOM_ISALIVE(sc) == 0)
783 		return EIO;
784 
785 	return (*tp->t_linesw->l_read)(tp, uio, flag);
786 }
787 
788 int
789 plcomwrite(dev_t dev, struct uio *uio, int flag)
790 {
791 	struct plcom_softc *sc = device_lookup(&plcom_cd, PLCOMUNIT(dev));
792 	struct tty *tp = sc->sc_tty;
793 
794 	if (PLCOM_ISALIVE(sc) == 0)
795 		return EIO;
796 
797 	return (*tp->t_linesw->l_write)(tp, uio, flag);
798 }
799 
800 int
801 plcompoll(dev_t dev, int events, struct lwp *l)
802 {
803 	struct plcom_softc *sc = device_lookup(&plcom_cd, PLCOMUNIT(dev));
804 	struct tty *tp = sc->sc_tty;
805 
806 	if (PLCOM_ISALIVE(sc) == 0)
807 		return EIO;
808 
809 	return (*tp->t_linesw->l_poll)(tp, events, l);
810 }
811 
812 struct tty *
813 plcomtty(dev_t dev)
814 {
815 	struct plcom_softc *sc = device_lookup(&plcom_cd, PLCOMUNIT(dev));
816 	struct tty *tp = sc->sc_tty;
817 
818 	return tp;
819 }
820 
821 int
822 plcomioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
823 {
824 	struct plcom_softc *sc = device_lookup(&plcom_cd, PLCOMUNIT(dev));
825 	struct tty *tp = sc->sc_tty;
826 	int error;
827 	int s;
828 
829 	if (PLCOM_ISALIVE(sc) == 0)
830 		return EIO;
831 
832 	error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, l);
833 	if (error != EPASSTHROUGH)
834 		return error;
835 
836 	error = ttioctl(tp, cmd, data, flag, l);
837 	if (error != EPASSTHROUGH)
838 		return error;
839 
840 	error = 0;
841 
842 	s = splserial();
843 	PLCOM_LOCK(sc);
844 
845 	switch (cmd) {
846 	case TIOCSBRK:
847 		plcom_break(sc, 1);
848 		break;
849 
850 	case TIOCCBRK:
851 		plcom_break(sc, 0);
852 		break;
853 
854 	case TIOCSDTR:
855 		plcom_modem(sc, 1);
856 		break;
857 
858 	case TIOCCDTR:
859 		plcom_modem(sc, 0);
860 		break;
861 
862 	case TIOCGFLAGS:
863 		*(int *)data = sc->sc_swflags;
864 		break;
865 
866 	case TIOCSFLAGS:
867 		error = kauth_authorize_device_tty(l->l_cred,
868 		    KAUTH_DEVICE_TTY_PRIVSET, tp);
869 		if (error)
870 			break;
871 		sc->sc_swflags = *(int *)data;
872 		break;
873 
874 	case TIOCMSET:
875 	case TIOCMBIS:
876 	case TIOCMBIC:
877 		tiocm_to_plcom(sc, cmd, *(int *)data);
878 		break;
879 
880 	case TIOCMGET:
881 		*(int *)data = plcom_to_tiocm(sc);
882 		break;
883 
884 	case PPS_IOC_CREATE:
885 		break;
886 
887 	case PPS_IOC_DESTROY:
888 		break;
889 
890 	case PPS_IOC_GETPARAMS: {
891 		pps_params_t *pp;
892 		pp = (pps_params_t *)data;
893 		*pp = sc->ppsparam;
894 		break;
895 	}
896 
897 	case PPS_IOC_SETPARAMS: {
898 	  	pps_params_t *pp;
899 		int mode;
900 		pp = (pps_params_t *)data;
901 		if (pp->mode & ~ppscap) {
902 			error = EINVAL;
903 			break;
904 		}
905 		sc->ppsparam = *pp;
906 	 	/*
907 		 * Compute msr masks from user-specified timestamp state.
908 		 */
909 		mode = sc->ppsparam.mode;
910 #ifdef	PPS_SYNC
911 		if (mode & PPS_HARDPPSONASSERT) {
912 			mode |= PPS_CAPTUREASSERT;
913 			/* XXX revoke any previous HARDPPS source */
914 		}
915 		if (mode & PPS_HARDPPSONCLEAR) {
916 			mode |= PPS_CAPTURECLEAR;
917 			/* XXX revoke any previous HARDPPS source */
918 		}
919 #endif	/* PPS_SYNC */
920 		switch (mode & PPS_CAPTUREBOTH) {
921 		case 0:
922 			sc->sc_ppsmask = 0;
923 			break;
924 
925 		case PPS_CAPTUREASSERT:
926 			sc->sc_ppsmask = MSR_DCD;
927 			sc->sc_ppsassert = MSR_DCD;
928 			sc->sc_ppsclear = -1;
929 			break;
930 
931 		case PPS_CAPTURECLEAR:
932 			sc->sc_ppsmask = MSR_DCD;
933 			sc->sc_ppsassert = -1;
934 			sc->sc_ppsclear = 0;
935 			break;
936 
937 		case PPS_CAPTUREBOTH:
938 			sc->sc_ppsmask = MSR_DCD;
939 			sc->sc_ppsassert = MSR_DCD;
940 			sc->sc_ppsclear = 0;
941 			break;
942 
943 		default:
944 			error = EINVAL;
945 			break;
946 		}
947 		break;
948 	}
949 
950 	case PPS_IOC_GETCAP:
951 		*(int*)data = ppscap;
952 		break;
953 
954 	case PPS_IOC_FETCH: {
955 		pps_info_t *pi;
956 		pi = (pps_info_t *)data;
957 		*pi = sc->ppsinfo;
958 		break;
959 	}
960 
961 	case TIOCDCDTIMESTAMP:	/* XXX old, overloaded  API used by xntpd v3 */
962 		/*
963 		 * Some GPS clocks models use the falling rather than
964 		 * rising edge as the on-the-second signal.
965 		 * The old API has no way to specify PPS polarity.
966 		 */
967 		sc->sc_ppsmask = MSR_DCD;
968 #ifndef PPS_TRAILING_EDGE
969 		sc->sc_ppsassert = MSR_DCD;
970 		sc->sc_ppsclear = -1;
971 		TIMESPEC_TO_TIMEVAL((struct timeval *)data,
972 		    &sc->ppsinfo.assert_timestamp);
973 #else
974 		sc->sc_ppsassert = -1
975 		sc->sc_ppsclear = 0;
976 		TIMESPEC_TO_TIMEVAL((struct timeval *)data,
977 		    &sc->ppsinfo.clear_timestamp);
978 #endif
979 		break;
980 
981 	default:
982 		error = EPASSTHROUGH;
983 		break;
984 	}
985 
986 	PLCOM_UNLOCK(sc);
987 	splx(s);
988 
989 #ifdef PLCOM_DEBUG
990 	if (plcom_debug)
991 		plcomstatus(sc, "plcomioctl ");
992 #endif
993 
994 	return error;
995 }
996 
997 integrate void
998 plcom_schedrx(struct plcom_softc *sc)
999 {
1000 
1001 	sc->sc_rx_ready = 1;
1002 
1003 	/* Wake up the poller. */
1004 	softintr_schedule(sc->sc_si);
1005 }
1006 
1007 void
1008 plcom_break(struct plcom_softc *sc, int onoff)
1009 {
1010 
1011 	if (onoff)
1012 		SET(sc->sc_lcr, LCR_BRK);
1013 	else
1014 		CLR(sc->sc_lcr, LCR_BRK);
1015 
1016 	if (!sc->sc_heldchange) {
1017 		if (sc->sc_tx_busy) {
1018 			sc->sc_heldtbc = sc->sc_tbc;
1019 			sc->sc_tbc = 0;
1020 			sc->sc_heldchange = 1;
1021 		} else
1022 			plcom_loadchannelregs(sc);
1023 	}
1024 }
1025 
1026 void
1027 plcom_modem(struct plcom_softc *sc, int onoff)
1028 {
1029 
1030 	if (sc->sc_mcr_dtr == 0)
1031 		return;
1032 
1033 	if (onoff)
1034 		SET(sc->sc_mcr, sc->sc_mcr_dtr);
1035 	else
1036 		CLR(sc->sc_mcr, sc->sc_mcr_dtr);
1037 
1038 	if (!sc->sc_heldchange) {
1039 		if (sc->sc_tx_busy) {
1040 			sc->sc_heldtbc = sc->sc_tbc;
1041 			sc->sc_tbc = 0;
1042 			sc->sc_heldchange = 1;
1043 		} else
1044 			plcom_loadchannelregs(sc);
1045 	}
1046 }
1047 
1048 void
1049 tiocm_to_plcom(struct plcom_softc *sc, u_long how, int ttybits)
1050 {
1051 	u_char plcombits;
1052 
1053 	plcombits = 0;
1054 	if (ISSET(ttybits, TIOCM_DTR))
1055 		SET(plcombits, MCR_DTR);
1056 	if (ISSET(ttybits, TIOCM_RTS))
1057 		SET(plcombits, MCR_RTS);
1058 
1059 	switch (how) {
1060 	case TIOCMBIC:
1061 		CLR(sc->sc_mcr, plcombits);
1062 		break;
1063 
1064 	case TIOCMBIS:
1065 		SET(sc->sc_mcr, plcombits);
1066 		break;
1067 
1068 	case TIOCMSET:
1069 		CLR(sc->sc_mcr, MCR_DTR | MCR_RTS);
1070 		SET(sc->sc_mcr, plcombits);
1071 		break;
1072 	}
1073 
1074 	if (!sc->sc_heldchange) {
1075 		if (sc->sc_tx_busy) {
1076 			sc->sc_heldtbc = sc->sc_tbc;
1077 			sc->sc_tbc = 0;
1078 			sc->sc_heldchange = 1;
1079 		} else
1080 			plcom_loadchannelregs(sc);
1081 	}
1082 }
1083 
1084 int
1085 plcom_to_tiocm(struct plcom_softc *sc)
1086 {
1087 	u_char plcombits;
1088 	int ttybits = 0;
1089 
1090 	plcombits = sc->sc_mcr;
1091 	if (ISSET(plcombits, MCR_DTR))
1092 		SET(ttybits, TIOCM_DTR);
1093 	if (ISSET(plcombits, MCR_RTS))
1094 		SET(ttybits, TIOCM_RTS);
1095 
1096 	plcombits = sc->sc_msr;
1097 	if (ISSET(plcombits, MSR_DCD))
1098 		SET(ttybits, TIOCM_CD);
1099 	if (ISSET(plcombits, MSR_CTS))
1100 		SET(ttybits, TIOCM_CTS);
1101 	if (ISSET(plcombits, MSR_DSR))
1102 		SET(ttybits, TIOCM_DSR);
1103 
1104 	if (sc->sc_cr != 0)
1105 		SET(ttybits, TIOCM_LE);
1106 
1107 	return ttybits;
1108 }
1109 
1110 static u_char
1111 cflag2lcr(tcflag_t cflag)
1112 {
1113 	u_char lcr = 0;
1114 
1115 	switch (ISSET(cflag, CSIZE)) {
1116 	case CS5:
1117 		SET(lcr, LCR_5BITS);
1118 		break;
1119 	case CS6:
1120 		SET(lcr, LCR_6BITS);
1121 		break;
1122 	case CS7:
1123 		SET(lcr, LCR_7BITS);
1124 		break;
1125 	case CS8:
1126 		SET(lcr, LCR_8BITS);
1127 		break;
1128 	}
1129 	if (ISSET(cflag, PARENB)) {
1130 		SET(lcr, LCR_PEN);
1131 		if (!ISSET(cflag, PARODD))
1132 			SET(lcr, LCR_EPS);
1133 	}
1134 	if (ISSET(cflag, CSTOPB))
1135 		SET(lcr, LCR_STP2);
1136 
1137 	return lcr;
1138 }
1139 
1140 int
1141 plcomparam(struct tty *tp, struct termios *t)
1142 {
1143 	struct plcom_softc *sc = device_lookup(&plcom_cd, PLCOMUNIT(tp->t_dev));
1144 	int ospeed;
1145 	u_char lcr;
1146 	int s;
1147 
1148 	if (PLCOM_ISALIVE(sc) == 0)
1149 		return EIO;
1150 
1151 	ospeed = plcomspeed(t->c_ospeed, sc->sc_frequency);
1152 
1153 	/* Check requested parameters. */
1154 	if (ospeed < 0)
1155 		return EINVAL;
1156 	if (t->c_ispeed && t->c_ispeed != t->c_ospeed)
1157 		return EINVAL;
1158 
1159 	/*
1160 	 * For the console, always force CLOCAL and !HUPCL, so that the port
1161 	 * is always active.
1162 	 */
1163 	if (ISSET(sc->sc_swflags, TIOCFLAG_SOFTCAR) ||
1164 	    ISSET(sc->sc_hwflags, PLCOM_HW_CONSOLE)) {
1165 		SET(t->c_cflag, CLOCAL);
1166 		CLR(t->c_cflag, HUPCL);
1167 	}
1168 
1169 	/*
1170 	 * If there were no changes, don't do anything.  This avoids dropping
1171 	 * input and improves performance when all we did was frob things like
1172 	 * VMIN and VTIME.
1173 	 */
1174 	if (tp->t_ospeed == t->c_ospeed &&
1175 	    tp->t_cflag == t->c_cflag)
1176 		return 0;
1177 
1178 	lcr = ISSET(sc->sc_lcr, LCR_BRK) | cflag2lcr(t->c_cflag);
1179 
1180 	s = splserial();
1181 	PLCOM_LOCK(sc);
1182 
1183 	sc->sc_lcr = lcr;
1184 
1185 	/*
1186 	 * PL010 has a fixed-length FIFO trigger point.
1187 	 */
1188 	if (ISSET(sc->sc_hwflags, PLCOM_HW_FIFO))
1189 		sc->sc_fifo = 1;
1190 	else
1191 		sc->sc_fifo = 0;
1192 
1193 	if (sc->sc_fifo)
1194 		SET(sc->sc_lcr, LCR_FEN);
1195 
1196 	/*
1197 	 * If we're not in a mode that assumes a connection is present, then
1198 	 * ignore carrier changes.
1199 	 */
1200 	if (ISSET(t->c_cflag, CLOCAL | MDMBUF))
1201 		sc->sc_msr_dcd = 0;
1202 	else
1203 		sc->sc_msr_dcd = MSR_DCD;
1204 	/*
1205 	 * Set the flow control pins depending on the current flow control
1206 	 * mode.
1207 	 */
1208 	if (ISSET(t->c_cflag, CRTSCTS)) {
1209 		sc->sc_mcr_dtr = MCR_DTR;
1210 		sc->sc_mcr_rts = MCR_RTS;
1211 		sc->sc_msr_cts = MSR_CTS;
1212 	} else if (ISSET(t->c_cflag, MDMBUF)) {
1213 		/*
1214 		 * For DTR/DCD flow control, make sure we don't toggle DTR for
1215 		 * carrier detection.
1216 		 */
1217 		sc->sc_mcr_dtr = 0;
1218 		sc->sc_mcr_rts = MCR_DTR;
1219 		sc->sc_msr_cts = MSR_DCD;
1220 	} else {
1221 		/*
1222 		 * If no flow control, then always set RTS.  This will make
1223 		 * the other side happy if it mistakenly thinks we're doing
1224 		 * RTS/CTS flow control.
1225 		 */
1226 		sc->sc_mcr_dtr = MCR_DTR | MCR_RTS;
1227 		sc->sc_mcr_rts = 0;
1228 		sc->sc_msr_cts = 0;
1229 		if (ISSET(sc->sc_mcr, MCR_DTR))
1230 			SET(sc->sc_mcr, MCR_RTS);
1231 		else
1232 			CLR(sc->sc_mcr, MCR_RTS);
1233 	}
1234 	sc->sc_msr_mask = sc->sc_msr_cts | sc->sc_msr_dcd;
1235 
1236 #if 0
1237 	if (ospeed == 0)
1238 		CLR(sc->sc_mcr, sc->sc_mcr_dtr);
1239 	else
1240 		SET(sc->sc_mcr, sc->sc_mcr_dtr);
1241 #endif
1242 
1243 	sc->sc_dlbl = ospeed;
1244 	sc->sc_dlbh = ospeed >> 8;
1245 
1246 	/* And copy to tty. */
1247 	tp->t_ispeed = 0;
1248 	tp->t_ospeed = t->c_ospeed;
1249 	tp->t_cflag = t->c_cflag;
1250 
1251 	if (!sc->sc_heldchange) {
1252 		if (sc->sc_tx_busy) {
1253 			sc->sc_heldtbc = sc->sc_tbc;
1254 			sc->sc_tbc = 0;
1255 			sc->sc_heldchange = 1;
1256 		} else
1257 			plcom_loadchannelregs(sc);
1258 	}
1259 
1260 	if (!ISSET(t->c_cflag, CHWFLOW)) {
1261 		/* Disable the high water mark. */
1262 		sc->sc_r_hiwat = 0;
1263 		sc->sc_r_lowat = 0;
1264 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
1265 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1266 			plcom_schedrx(sc);
1267 		}
1268 		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED)) {
1269 			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED);
1270 			plcom_hwiflow(sc);
1271 		}
1272 	} else {
1273 		sc->sc_r_hiwat = plcom_rbuf_hiwat;
1274 		sc->sc_r_lowat = plcom_rbuf_lowat;
1275 	}
1276 
1277 	PLCOM_UNLOCK(sc);
1278 	splx(s);
1279 
1280 	/*
1281 	 * Update the tty layer's idea of the carrier bit, in case we changed
1282 	 * CLOCAL or MDMBUF.  We don't hang up here; we only do that by
1283 	 * explicit request.
1284 	 */
1285 	(void) (*tp->t_linesw->l_modem)(tp, ISSET(sc->sc_msr, MSR_DCD));
1286 
1287 #ifdef PLCOM_DEBUG
1288 	if (plcom_debug)
1289 		plcomstatus(sc, "plcomparam ");
1290 #endif
1291 
1292 	if (!ISSET(t->c_cflag, CHWFLOW)) {
1293 		if (sc->sc_tx_stopped) {
1294 			sc->sc_tx_stopped = 0;
1295 			plcomstart(tp);
1296 		}
1297 	}
1298 
1299 	return 0;
1300 }
1301 
1302 void
1303 plcom_iflush(struct plcom_softc *sc)
1304 {
1305 	bus_space_tag_t iot = sc->sc_iot;
1306 	bus_space_handle_t ioh = sc->sc_ioh;
1307 #ifdef DIAGNOSTIC
1308 	int reg;
1309 #endif
1310 	int timo;
1311 
1312 #ifdef DIAGNOSTIC
1313 	reg = 0xffff;
1314 #endif
1315 	timo = 50000;
1316 	/* flush any pending I/O */
1317 	while (! ISSET(bus_space_read_1(iot, ioh, plcom_fr), FR_RXFE)
1318 	    && --timo)
1319 #ifdef DIAGNOSTIC
1320 		reg =
1321 #else
1322 		    (void)
1323 #endif
1324 		    bus_space_read_1(iot, ioh, plcom_dr);
1325 #ifdef DIAGNOSTIC
1326 	if (!timo)
1327 		printf("%s: plcom_iflush timeout %02x\n", sc->sc_dev.dv_xname,
1328 		       reg);
1329 #endif
1330 }
1331 
1332 void
1333 plcom_loadchannelregs(struct plcom_softc *sc)
1334 {
1335 	bus_space_tag_t iot = sc->sc_iot;
1336 	bus_space_handle_t ioh = sc->sc_ioh;
1337 
1338 	/* XXXXX necessary? */
1339 	plcom_iflush(sc);
1340 
1341 	bus_space_write_1(iot, ioh, plcom_cr, 0);
1342 
1343 	bus_space_write_1(iot, ioh, plcom_dlbl, sc->sc_dlbl);
1344 	bus_space_write_1(iot, ioh, plcom_dlbh, sc->sc_dlbh);
1345 	bus_space_write_1(iot, ioh, plcom_lcr, sc->sc_lcr);
1346 	/* XXX device_unit() abuse */
1347 	sc->sc_set_mcr(sc->sc_set_mcr_arg, device_unit(&sc->sc_dev),
1348 	    sc->sc_mcr_active = sc->sc_mcr);
1349 
1350 	bus_space_write_1(iot, ioh, plcom_cr, sc->sc_cr);
1351 }
1352 
1353 int
1354 plcomhwiflow(struct tty *tp, int block)
1355 {
1356 	struct plcom_softc *sc = device_lookup(&plcom_cd, PLCOMUNIT(tp->t_dev));
1357 	int s;
1358 
1359 	if (PLCOM_ISALIVE(sc) == 0)
1360 		return 0;
1361 
1362 	if (sc->sc_mcr_rts == 0)
1363 		return 0;
1364 
1365 	s = splserial();
1366 	PLCOM_LOCK(sc);
1367 
1368 	if (block) {
1369 		if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1370 			SET(sc->sc_rx_flags, RX_TTY_BLOCKED);
1371 			plcom_hwiflow(sc);
1372 		}
1373 	} else {
1374 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
1375 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1376 			plcom_schedrx(sc);
1377 		}
1378 		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1379 			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED);
1380 			plcom_hwiflow(sc);
1381 		}
1382 	}
1383 
1384 	PLCOM_UNLOCK(sc);
1385 	splx(s);
1386 	return 1;
1387 }
1388 
1389 /*
1390  * (un)block input via hw flowcontrol
1391  */
1392 void
1393 plcom_hwiflow(struct plcom_softc *sc)
1394 {
1395 	if (sc->sc_mcr_rts == 0)
1396 		return;
1397 
1398 	if (ISSET(sc->sc_rx_flags, RX_ANY_BLOCK)) {
1399 		CLR(sc->sc_mcr, sc->sc_mcr_rts);
1400 		CLR(sc->sc_mcr_active, sc->sc_mcr_rts);
1401 	} else {
1402 		SET(sc->sc_mcr, sc->sc_mcr_rts);
1403 		SET(sc->sc_mcr_active, sc->sc_mcr_rts);
1404 	}
1405 	/* XXX device_unit() abuse */
1406 	sc->sc_set_mcr(sc->sc_set_mcr_arg, device_unit(&sc->sc_dev),
1407 	    sc->sc_mcr_active);
1408 }
1409 
1410 
1411 void
1412 plcomstart(struct tty *tp)
1413 {
1414 	struct plcom_softc *sc = device_lookup(&plcom_cd, PLCOMUNIT(tp->t_dev));
1415 	bus_space_tag_t iot = sc->sc_iot;
1416 	bus_space_handle_t ioh = sc->sc_ioh;
1417 	int s;
1418 
1419 	if (PLCOM_ISALIVE(sc) == 0)
1420 		return;
1421 
1422 	s = spltty();
1423 	if (ISSET(tp->t_state, TS_BUSY | TS_TIMEOUT | TS_TTSTOP))
1424 		goto out;
1425 	if (sc->sc_tx_stopped)
1426 		goto out;
1427 
1428 	if (!ttypull(tp))
1429 		goto out;
1430 
1431 	/* Grab the first contiguous region of buffer space. */
1432 	{
1433 		u_char *tba;
1434 		int tbc;
1435 
1436 		tba = tp->t_outq.c_cf;
1437 		tbc = ndqb(&tp->t_outq, 0);
1438 
1439 		(void)splserial();
1440 		PLCOM_LOCK(sc);
1441 
1442 		sc->sc_tba = tba;
1443 		sc->sc_tbc = tbc;
1444 	}
1445 
1446 	SET(tp->t_state, TS_BUSY);
1447 	sc->sc_tx_busy = 1;
1448 
1449 	/* Enable transmit completion interrupts if necessary. */
1450 	if (!ISSET(sc->sc_cr, CR_TIE)) {
1451 		SET(sc->sc_cr, CR_TIE);
1452 		bus_space_write_1(iot, ioh, plcom_cr, sc->sc_cr);
1453 	}
1454 
1455 	/* Output the first chunk of the contiguous buffer. */
1456 	{
1457 		int n;
1458 
1459 		n = sc->sc_tbc;
1460 		if (n > sc->sc_fifolen)
1461 			n = sc->sc_fifolen;
1462 		bus_space_write_multi_1(iot, ioh, plcom_dr, sc->sc_tba, n);
1463 		sc->sc_tbc -= n;
1464 		sc->sc_tba += n;
1465 	}
1466 	PLCOM_UNLOCK(sc);
1467 out:
1468 	splx(s);
1469 	return;
1470 }
1471 
1472 /*
1473  * Stop output on a line.
1474  */
1475 void
1476 plcomstop(struct tty *tp, int flag)
1477 {
1478 	struct plcom_softc *sc = device_lookup(&plcom_cd, PLCOMUNIT(tp->t_dev));
1479 	int s;
1480 
1481 	s = splserial();
1482 	PLCOM_LOCK(sc);
1483 	if (ISSET(tp->t_state, TS_BUSY)) {
1484 		/* Stop transmitting at the next chunk. */
1485 		sc->sc_tbc = 0;
1486 		sc->sc_heldtbc = 0;
1487 		if (!ISSET(tp->t_state, TS_TTSTOP))
1488 			SET(tp->t_state, TS_FLUSH);
1489 	}
1490 	PLCOM_UNLOCK(sc);
1491 	splx(s);
1492 }
1493 
1494 void
1495 plcomdiag(void *arg)
1496 {
1497 	struct plcom_softc *sc = arg;
1498 	int overflows, floods;
1499 	int s;
1500 
1501 	s = splserial();
1502 	PLCOM_LOCK(sc);
1503 	overflows = sc->sc_overflows;
1504 	sc->sc_overflows = 0;
1505 	floods = sc->sc_floods;
1506 	sc->sc_floods = 0;
1507 	sc->sc_errors = 0;
1508 	PLCOM_UNLOCK(sc);
1509 	splx(s);
1510 
1511 	log(LOG_WARNING, "%s: %d silo overflow%s, %d ibuf flood%s\n",
1512 	    sc->sc_dev.dv_xname,
1513 	    overflows, overflows == 1 ? "" : "s",
1514 	    floods, floods == 1 ? "" : "s");
1515 }
1516 
1517 integrate void
1518 plcom_rxsoft(struct plcom_softc *sc, struct tty *tp)
1519 {
1520 	int (*rint) (int, struct tty *) = tp->t_linesw->l_rint;
1521 	u_char *get, *end;
1522 	u_int cc, scc;
1523 	u_char rsr;
1524 	int code;
1525 	int s;
1526 
1527 	end = sc->sc_ebuf;
1528 	get = sc->sc_rbget;
1529 	scc = cc = plcom_rbuf_size - sc->sc_rbavail;
1530 
1531 	if (cc == plcom_rbuf_size) {
1532 		sc->sc_floods++;
1533 		if (sc->sc_errors++ == 0)
1534 			callout_reset(&sc->sc_diag_callout, 60 * hz,
1535 			    plcomdiag, sc);
1536 	}
1537 
1538 	while (cc) {
1539 		code = get[0];
1540 		rsr = get[1];
1541 		if (ISSET(rsr, RSR_OE | RSR_BE | RSR_FE | RSR_PE)) {
1542 			if (ISSET(rsr, RSR_OE)) {
1543 				sc->sc_overflows++;
1544 				if (sc->sc_errors++ == 0)
1545 					callout_reset(&sc->sc_diag_callout,
1546 					    60 * hz, plcomdiag, sc);
1547 			}
1548 			if (ISSET(rsr, RSR_BE | RSR_FE))
1549 				SET(code, TTY_FE);
1550 			if (ISSET(rsr, RSR_PE))
1551 				SET(code, TTY_PE);
1552 		}
1553 		if ((*rint)(code, tp) == -1) {
1554 			/*
1555 			 * The line discipline's buffer is out of space.
1556 			 */
1557 			if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1558 				/*
1559 				 * We're either not using flow control, or the
1560 				 * line discipline didn't tell us to block for
1561 				 * some reason.  Either way, we have no way to
1562 				 * know when there's more space available, so
1563 				 * just drop the rest of the data.
1564 				 */
1565 				get += cc << 1;
1566 				if (get >= end)
1567 					get -= plcom_rbuf_size << 1;
1568 				cc = 0;
1569 			} else {
1570 				/*
1571 				 * Don't schedule any more receive processing
1572 				 * until the line discipline tells us there's
1573 				 * space available (through plcomhwiflow()).
1574 				 * Leave the rest of the data in the input
1575 				 * buffer.
1576 				 */
1577 				SET(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1578 			}
1579 			break;
1580 		}
1581 		get += 2;
1582 		if (get >= end)
1583 			get = sc->sc_rbuf;
1584 		cc--;
1585 	}
1586 
1587 	if (cc != scc) {
1588 		sc->sc_rbget = get;
1589 		s = splserial();
1590 		PLCOM_LOCK(sc);
1591 
1592 		cc = sc->sc_rbavail += scc - cc;
1593 		/* Buffers should be ok again, release possible block. */
1594 		if (cc >= sc->sc_r_lowat) {
1595 			if (ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
1596 				CLR(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
1597 				SET(sc->sc_cr, CR_RIE | CR_RTIE);
1598 				bus_space_write_1(sc->sc_iot, sc->sc_ioh, plcom_cr, sc->sc_cr);
1599 			}
1600 			if (ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED)) {
1601 				CLR(sc->sc_rx_flags, RX_IBUF_BLOCKED);
1602 				plcom_hwiflow(sc);
1603 			}
1604 		}
1605 		PLCOM_UNLOCK(sc);
1606 		splx(s);
1607 	}
1608 }
1609 
1610 integrate void
1611 plcom_txsoft(struct plcom_softc *sc, struct tty *tp)
1612 {
1613 
1614 	CLR(tp->t_state, TS_BUSY);
1615 	if (ISSET(tp->t_state, TS_FLUSH))
1616 		CLR(tp->t_state, TS_FLUSH);
1617 	else
1618 		ndflush(&tp->t_outq, (int)(sc->sc_tba - tp->t_outq.c_cf));
1619 	(*tp->t_linesw->l_start)(tp);
1620 }
1621 
1622 integrate void
1623 plcom_stsoft(struct plcom_softc *sc, struct tty *tp)
1624 {
1625 	u_char msr, delta;
1626 	int s;
1627 
1628 	s = splserial();
1629 	PLCOM_LOCK(sc);
1630 	msr = sc->sc_msr;
1631 	delta = sc->sc_msr_delta;
1632 	sc->sc_msr_delta = 0;
1633 	PLCOM_UNLOCK(sc);
1634 	splx(s);
1635 
1636 	if (ISSET(delta, sc->sc_msr_dcd)) {
1637 		/*
1638 		 * Inform the tty layer that carrier detect changed.
1639 		 */
1640 		(void) (*tp->t_linesw->l_modem)(tp, ISSET(msr, MSR_DCD));
1641 	}
1642 
1643 	if (ISSET(delta, sc->sc_msr_cts)) {
1644 		/* Block or unblock output according to flow control. */
1645 		if (ISSET(msr, sc->sc_msr_cts)) {
1646 			sc->sc_tx_stopped = 0;
1647 			(*tp->t_linesw->l_start)(tp);
1648 		} else {
1649 			sc->sc_tx_stopped = 1;
1650 		}
1651 	}
1652 
1653 #ifdef PLCOM_DEBUG
1654 	if (plcom_debug)
1655 		plcomstatus(sc, "plcom_stsoft");
1656 #endif
1657 }
1658 
1659 void
1660 plcomsoft(void *arg)
1661 {
1662 	struct plcom_softc *sc = arg;
1663 	struct tty *tp;
1664 
1665 	if (PLCOM_ISALIVE(sc) == 0)
1666 		return;
1667 
1668 	tp = sc->sc_tty;
1669 
1670 	if (sc->sc_rx_ready) {
1671 		sc->sc_rx_ready = 0;
1672 		plcom_rxsoft(sc, tp);
1673 	}
1674 
1675 	if (sc->sc_st_check) {
1676 		sc->sc_st_check = 0;
1677 		plcom_stsoft(sc, tp);
1678 	}
1679 
1680 	if (sc->sc_tx_done) {
1681 		sc->sc_tx_done = 0;
1682 		plcom_txsoft(sc, tp);
1683 	}
1684 }
1685 
1686 int
1687 plcomintr(void *arg)
1688 {
1689 	struct plcom_softc *sc = arg;
1690 	bus_space_tag_t iot = sc->sc_iot;
1691 	bus_space_handle_t ioh = sc->sc_ioh;
1692 	u_char *put, *end;
1693 	u_int cc;
1694 	u_char rsr, iir;
1695 
1696 	if (PLCOM_ISALIVE(sc) == 0)
1697 		return 0;
1698 
1699 	PLCOM_LOCK(sc);
1700 	iir = bus_space_read_1(iot, ioh, plcom_iir);
1701 	if (! ISSET(iir, IIR_IMASK)) {
1702 		PLCOM_UNLOCK(sc);
1703 		return 0;
1704 	}
1705 
1706 	end = sc->sc_ebuf;
1707 	put = sc->sc_rbput;
1708 	cc = sc->sc_rbavail;
1709 
1710 	do {
1711 		u_char	msr, delta, fr;
1712 
1713 		fr = bus_space_read_1(iot, ioh, plcom_fr);
1714 
1715 		if (!ISSET(fr, FR_RXFE) &&
1716 		    !ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
1717 			while (cc > 0) {
1718 				int cn_trapped = 0;
1719 				put[0] = bus_space_read_1(iot, ioh,
1720 				    plcom_dr);
1721 				rsr = bus_space_read_1(iot, ioh, plcom_rsr);
1722 				/* Clear any error status.  */
1723 				if (ISSET(rsr,
1724 				    (RSR_BE | RSR_OE | RSR_PE | RSR_FE)))
1725 					bus_space_write_1(iot, ioh, plcom_ecr,
1726 					    0);
1727 				if (ISSET(rsr, RSR_BE)) {
1728 					cn_trapped = 0;
1729 					cn_check_magic(sc->sc_tty->t_dev,
1730 					    CNC_BREAK, plcom_cnm_state);
1731 					if (cn_trapped)
1732 						continue;
1733 #if defined(KGDB)
1734 					if (ISSET(sc->sc_hwflags,
1735 					    PLCOM_HW_KGDB)) {
1736 						kgdb_connect(1);
1737 						continue;
1738 					}
1739 #endif
1740 				}
1741 
1742 				put[1] = rsr;
1743 				cn_trapped = 0;
1744 				cn_check_magic(sc->sc_tty->t_dev,
1745 					       put[0], plcom_cnm_state);
1746 				if (cn_trapped) {
1747 					fr = bus_space_read_1(iot, ioh,
1748 					    plcom_fr);
1749 					if (ISSET(fr, FR_RXFE))
1750 						break;
1751 
1752 					continue;
1753 				}
1754 				put += 2;
1755 				if (put >= end)
1756 					put = sc->sc_rbuf;
1757 				cc--;
1758 
1759 				fr = bus_space_read_1(iot, ioh, plcom_fr);
1760 				if (ISSET(fr, FR_RXFE))
1761 					break;
1762 			}
1763 
1764 			/*
1765 			 * Current string of incoming characters ended because
1766 			 * no more data was available or we ran out of space.
1767 			 * Schedule a receive event if any data was received.
1768 			 * If we're out of space, turn off receive interrupts.
1769 			 */
1770 			sc->sc_rbput = put;
1771 			sc->sc_rbavail = cc;
1772 			if (!ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED))
1773 				sc->sc_rx_ready = 1;
1774 
1775 			/*
1776 			 * See if we are in danger of overflowing a buffer. If
1777 			 * so, use hardware flow control to ease the pressure.
1778 			 */
1779 			if (!ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED) &&
1780 			    cc < sc->sc_r_hiwat) {
1781 				SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
1782 				plcom_hwiflow(sc);
1783 			}
1784 
1785 			/*
1786 			 * If we're out of space, disable receive interrupts
1787 			 * until the queue has drained a bit.
1788 			 */
1789 			if (!cc) {
1790 				SET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
1791 				CLR(sc->sc_cr, CR_RIE | CR_RTIE);
1792 				bus_space_write_1(iot, ioh, plcom_cr,
1793 				    sc->sc_cr);
1794 			}
1795 		} else {
1796 			if (ISSET(iir, IIR_RIS)) {
1797 				bus_space_write_1(iot, ioh, plcom_cr, 0);
1798 				delay(10);
1799 				bus_space_write_1(iot, ioh, plcom_cr,
1800 				    sc->sc_cr);
1801 				continue;
1802 			}
1803 		}
1804 
1805 		msr = bus_space_read_1(iot, ioh, plcom_fr);
1806 		delta = msr ^ sc->sc_msr;
1807 		sc->sc_msr = msr;
1808 		/* Clear any pending modem status interrupt.  */
1809 		if (iir & IIR_MIS)
1810 			bus_space_write_1(iot, ioh, plcom_icr, 0);
1811 		/*
1812 		 * Pulse-per-second (PSS) signals on edge of DCD?
1813 		 * Process these even if line discipline is ignoring DCD.
1814 		 */
1815 		if (delta & sc->sc_ppsmask) {
1816 			struct timeval tv;
1817 		    	if ((msr & sc->sc_ppsmask) == sc->sc_ppsassert) {
1818 				/* XXX nanotime() */
1819 				microtime(&tv);
1820 				TIMEVAL_TO_TIMESPEC(&tv,
1821 				    &sc->ppsinfo.assert_timestamp);
1822 				if (sc->ppsparam.mode & PPS_OFFSETASSERT) {
1823 					timespecadd(&sc->ppsinfo.assert_timestamp,
1824 					    &sc->ppsparam.assert_offset,
1825 						    &sc->ppsinfo.assert_timestamp);
1826 				}
1827 
1828 #ifdef PPS_SYNC
1829 				if (sc->ppsparam.mode & PPS_HARDPPSONASSERT)
1830 					hardpps(&tv, tv.tv_usec);
1831 #endif
1832 				sc->ppsinfo.assert_sequence++;
1833 				sc->ppsinfo.current_mode = sc->ppsparam.mode;
1834 
1835 			} else if ((msr & sc->sc_ppsmask) == sc->sc_ppsclear) {
1836 				/* XXX nanotime() */
1837 				microtime(&tv);
1838 				TIMEVAL_TO_TIMESPEC(&tv,
1839 				    &sc->ppsinfo.clear_timestamp);
1840 				if (sc->ppsparam.mode & PPS_OFFSETCLEAR) {
1841 					timespecadd(&sc->ppsinfo.clear_timestamp,
1842 					    &sc->ppsparam.clear_offset,
1843 					    &sc->ppsinfo.clear_timestamp);
1844 				}
1845 
1846 #ifdef PPS_SYNC
1847 				if (sc->ppsparam.mode & PPS_HARDPPSONCLEAR)
1848 					hardpps(&tv, tv.tv_usec);
1849 #endif
1850 				sc->ppsinfo.clear_sequence++;
1851 				sc->ppsinfo.current_mode = sc->ppsparam.mode;
1852 			}
1853 		}
1854 
1855 		/*
1856 		 * Process normal status changes
1857 		 */
1858 		if (ISSET(delta, sc->sc_msr_mask)) {
1859 			SET(sc->sc_msr_delta, delta);
1860 
1861 			/*
1862 			 * Stop output immediately if we lose the output
1863 			 * flow control signal or carrier detect.
1864 			 */
1865 			if (ISSET(~msr, sc->sc_msr_mask)) {
1866 				sc->sc_tbc = 0;
1867 				sc->sc_heldtbc = 0;
1868 #ifdef PLCOM_DEBUG
1869 				if (plcom_debug)
1870 					plcomstatus(sc, "plcomintr  ");
1871 #endif
1872 			}
1873 
1874 			sc->sc_st_check = 1;
1875 		}
1876 
1877 		/*
1878 		 * Done handling any receive interrupts. See if data
1879 		 * can be * transmitted as well. Schedule tx done
1880 		 * event if no data left * and tty was marked busy.
1881 		 */
1882 		if (ISSET(iir, IIR_TIS)) {
1883 			/*
1884 			 * If we've delayed a parameter change, do it
1885 			 * now, and restart * output.
1886 			 */
1887 			if (sc->sc_heldchange) {
1888 				plcom_loadchannelregs(sc);
1889 				sc->sc_heldchange = 0;
1890 				sc->sc_tbc = sc->sc_heldtbc;
1891 				sc->sc_heldtbc = 0;
1892 			}
1893 
1894 			/*
1895 			 * Output the next chunk of the contiguous
1896 			 * buffer, if any.
1897 			 */
1898 			if (sc->sc_tbc > 0) {
1899 				int n;
1900 
1901 				n = sc->sc_tbc;
1902 				if (n > sc->sc_fifolen)
1903 					n = sc->sc_fifolen;
1904 				bus_space_write_multi_1(iot, ioh, plcom_dr,
1905 				    sc->sc_tba, n);
1906 				sc->sc_tbc -= n;
1907 				sc->sc_tba += n;
1908 			} else {
1909 				/*
1910 				 * Disable transmit plcompletion
1911 				 * interrupts if necessary.
1912 				 */
1913 				if (ISSET(sc->sc_cr, CR_TIE)) {
1914 					CLR(sc->sc_cr, CR_TIE);
1915 					bus_space_write_1(iot, ioh, plcom_cr,
1916 					    sc->sc_cr);
1917 				}
1918 				if (sc->sc_tx_busy) {
1919 					sc->sc_tx_busy = 0;
1920 					sc->sc_tx_done = 1;
1921 				}
1922 			}
1923 		}
1924 	} while (ISSET((iir = bus_space_read_1(iot, ioh, plcom_iir)),
1925 	    IIR_IMASK));
1926 
1927 	PLCOM_UNLOCK(sc);
1928 
1929 	/* Wake up the poller. */
1930 	softintr_schedule(sc->sc_si);
1931 
1932 #if NRND > 0 && defined(RND_COM)
1933 	rnd_add_uint32(&sc->rnd_source, iir | rsr);
1934 #endif
1935 
1936 	return 1;
1937 }
1938 
1939 /*
1940  * The following functions are polled getc and putc routines, shared
1941  * by the console and kgdb glue.
1942  *
1943  * The read-ahead code is so that you can detect pending in-band
1944  * cn_magic in polled mode while doing output rather than having to
1945  * wait until the kernel decides it needs input.
1946  */
1947 
1948 #define MAX_READAHEAD	20
1949 static int plcom_readahead[MAX_READAHEAD];
1950 static int plcom_readaheadcount = 0;
1951 
1952 int
1953 plcom_common_getc(dev_t dev, bus_space_tag_t iot, bus_space_handle_t ioh)
1954 {
1955 	int s = splserial();
1956 	u_char stat, c;
1957 
1958 	/* got a character from reading things earlier */
1959 	if (plcom_readaheadcount > 0) {
1960 		int i;
1961 
1962 		c = plcom_readahead[0];
1963 		for (i = 1; i < plcom_readaheadcount; i++) {
1964 			plcom_readahead[i-1] = plcom_readahead[i];
1965 		}
1966 		plcom_readaheadcount--;
1967 		splx(s);
1968 		return c;
1969 	}
1970 
1971 	/* block until a character becomes available */
1972 	while (ISSET(stat = bus_space_read_1(iot, ioh, plcom_fr), FR_RXFE))
1973 		;
1974 
1975 	c = bus_space_read_1(iot, ioh, plcom_dr);
1976 	stat = bus_space_read_1(iot, ioh, plcom_iir);
1977 	{
1978 		int cn_trapped = 0; /* unused */
1979 #ifdef DDB
1980 		extern int db_active;
1981 		if (!db_active)
1982 #endif
1983 			cn_check_magic(dev, c, plcom_cnm_state);
1984 	}
1985 	splx(s);
1986 	return c;
1987 }
1988 
1989 void
1990 plcom_common_putc(dev_t dev, bus_space_tag_t iot, bus_space_handle_t ioh,
1991     int c)
1992 {
1993 	int s = splserial();
1994 	int timo;
1995 
1996 	int cin, stat;
1997 	if (plcom_readaheadcount < MAX_READAHEAD
1998 	     && !ISSET(stat = bus_space_read_1(iot, ioh, plcom_fr), FR_RXFE)) {
1999 		int cn_trapped = 0;
2000 		cin = bus_space_read_1(iot, ioh, plcom_dr);
2001 		stat = bus_space_read_1(iot, ioh, plcom_iir);
2002 		cn_check_magic(dev, cin, plcom_cnm_state);
2003 		plcom_readahead[plcom_readaheadcount++] = cin;
2004 	}
2005 
2006 	/* wait for any pending transmission to finish */
2007 	timo = 150000;
2008 	while (!ISSET(bus_space_read_1(iot, ioh, plcom_fr), FR_TXFE) && --timo)
2009 		continue;
2010 
2011 	bus_space_write_1(iot, ioh, plcom_dr, c);
2012 	PLCOM_BARRIER(iot, ioh, BR | BW);
2013 
2014 	/* wait for this transmission to complete */
2015 	timo = 1500000;
2016 	while (!ISSET(bus_space_read_1(iot, ioh, plcom_fr), FR_TXFE) && --timo)
2017 		continue;
2018 
2019 	splx(s);
2020 }
2021 
2022 /*
2023  * Initialize UART for use as console or KGDB line.
2024  */
2025 int
2026 plcominit(bus_space_tag_t iot, bus_addr_t iobase, int rate, int frequency,
2027     tcflag_t cflag, bus_space_handle_t *iohp)
2028 {
2029 	bus_space_handle_t ioh;
2030 
2031 	if (bus_space_map(iot, iobase, PLCOM_UART_SIZE, 0, &ioh))
2032 		return ENOMEM; /* ??? */
2033 
2034 	rate = plcomspeed(rate, frequency);
2035 	bus_space_write_1(iot, ioh, plcom_cr, 0);
2036 	bus_space_write_1(iot, ioh, plcom_dlbl, rate);
2037 	bus_space_write_1(iot, ioh, plcom_dlbh, rate >> 8);
2038 	bus_space_write_1(iot, ioh, plcom_lcr, cflag2lcr(cflag) | LCR_FEN);
2039 	bus_space_write_1(iot, ioh, plcom_cr, CR_UARTEN);
2040 
2041 #if 0
2042 	/* Ought to do something like this, but we have no sc to
2043 	   dereference. */
2044 	/* XXX device_unit() abuse */
2045 	sc->sc_set_mcr(sc->sc_set_mcr_arg, device_unit(&sc->sc_dev),
2046 	    MCR_DTR | MCR_RTS);
2047 #endif
2048 
2049 	*iohp = ioh;
2050 	return 0;
2051 }
2052 
2053 /*
2054  * Following are all routines needed for PLCOM to act as console
2055  */
2056 struct consdev plcomcons = {
2057 	NULL, NULL, plcomcngetc, plcomcnputc, plcomcnpollc, NULL,
2058 	NULL, NULL, NODEV, CN_NORMAL
2059 };
2060 
2061 
2062 int
2063 plcomcnattach(bus_space_tag_t iot, bus_addr_t iobase, int rate, int frequency,
2064     tcflag_t cflag, int unit)
2065 {
2066 	int res;
2067 
2068 	res = plcominit(iot, iobase, rate, frequency, cflag, &plcomconsioh);
2069 	if (res)
2070 		return res;
2071 
2072 	cn_tab = &plcomcons;
2073 	cn_init_magic(&plcom_cnm_state);
2074 	cn_set_magic("\047\001"); /* default magic is BREAK */
2075 
2076 	plcomconstag = iot;
2077 	plcomconsunit = unit;
2078 	plcomconsrate = rate;
2079 	plcomconscflag = cflag;
2080 
2081 	return 0;
2082 }
2083 
2084 void
2085 plcomcndetach(void)
2086 {
2087 	bus_space_unmap(plcomconstag, plcomconsioh, PLCOM_UART_SIZE);
2088 	plcomconstag = NULL;
2089 
2090 	cn_tab = NULL;
2091 }
2092 
2093 int
2094 plcomcngetc(dev_t dev)
2095 {
2096 	return plcom_common_getc(dev, plcomconstag, plcomconsioh);
2097 }
2098 
2099 /*
2100  * Console kernel output character routine.
2101  */
2102 void
2103 plcomcnputc(dev_t dev, int c)
2104 {
2105 	plcom_common_putc(dev, plcomconstag, plcomconsioh, c);
2106 }
2107 
2108 void
2109 plcomcnpollc(dev_t dev, int on)
2110 {
2111 
2112 }
2113 
2114 #ifdef KGDB
2115 int
2116 plcom_kgdb_attach(bus_space_tag_t iot, bus_addr_t iobase, int rate,
2117    int frequency, tcflag_t cflag, int unit)
2118 {
2119 	int res;
2120 
2121 	if (iot == plcomconstag && iobase == plcomconsunit)
2122 		return EBUSY; /* cannot share with console */
2123 
2124 	res = plcominit(iot, iobase, rate, frequency, cflag, &plcom_kgdb_ioh);
2125 	if (res)
2126 		return res;
2127 
2128 	kgdb_attach(plcom_kgdb_getc, plcom_kgdb_putc, NULL);
2129 	kgdb_dev = 123; /* unneeded, only to satisfy some tests */
2130 
2131 	plcom_kgdb_iot = iot;
2132 	plcom_kgdb_unit = unit;
2133 
2134 	return 0;
2135 }
2136 
2137 /* ARGSUSED */
2138 int
2139 plcom_kgdb_getc(void *arg)
2140 {
2141 	return plcom_common_getc(NODEV, plcom_kgdb_iot, plcom_kgdb_ioh);
2142 }
2143 
2144 /* ARGSUSED */
2145 void
2146 plcom_kgdb_putc(void *arg, int c)
2147 {
2148 	plcom_common_putc(NODEV, plcom_kgdb_iot, plcom_kgdb_ioh, c);
2149 }
2150 #endif /* KGDB */
2151 
2152 /* helper function to identify the plcom ports used by
2153  console or KGDB (and not yet autoconf attached) */
2154 int
2155 plcom_is_console(bus_space_tag_t iot, int unit,
2156     bus_space_handle_t *ioh)
2157 {
2158 	bus_space_handle_t help;
2159 
2160 	if (!plcomconsattached &&
2161 	    iot == plcomconstag && unit == plcomconsunit)
2162 		help = plcomconsioh;
2163 #ifdef KGDB
2164 	else if (!plcom_kgdb_attached &&
2165 	    iot == plcom_kgdb_iot && unit == plcom_kgdb_unit)
2166 		help = plcom_kgdb_ioh;
2167 #endif
2168 	else
2169 		return 0;
2170 
2171 	if (ioh)
2172 		*ioh = help;
2173 	return 1;
2174 }
2175