xref: /netbsd-src/sys/arch/evbarm/dev/plcom.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /*	$NetBSD: plcom.c,v 1.31 2009/12/06 21:38:42 dyoung 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  *
46  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
47  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
48  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
49  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
50  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
51  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
52  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
53  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
54  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
55  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
56  * POSSIBILITY OF SUCH DAMAGE.
57  */
58 
59 /*
60  * Copyright (c) 1991 The Regents of the University of California.
61  * All rights reserved.
62  *
63  * Redistribution and use in source and binary forms, with or without
64  * modification, are permitted provided that the following conditions
65  * are met:
66  * 1. Redistributions of source code must retain the above copyright
67  *    notice, this list of conditions and the following disclaimer.
68  * 2. Redistributions in binary form must reproduce the above copyright
69  *    notice, this list of conditions and the following disclaimer in the
70  *    documentation and/or other materials provided with the distribution.
71  * 3. Neither the name of the University nor the names of its contributors
72  *    may be used to endorse or promote products derived from this software
73  *    without specific prior written permission.
74  *
75  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
76  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
77  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
78  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
79  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
80  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
81  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
82  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
83  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
84  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
85  * SUCH DAMAGE.
86  *
87  *	@(#)com.c	7.5 (Berkeley) 5/16/91
88  */
89 
90 /*
91  * COM driver for the Prime Cell PL010 UART, which is similar to the 16C550,
92  * but has a completely different programmer's model.
93  * Derived from the NS16550AF com driver.
94  */
95 
96 #include <sys/cdefs.h>
97 __KERNEL_RCSID(0, "$NetBSD: plcom.c,v 1.31 2009/12/06 21:38:42 dyoung Exp $");
98 
99 #include "opt_plcom.h"
100 #include "opt_ddb.h"
101 #include "opt_kgdb.h"
102 #include "opt_lockdebug.h"
103 #include "opt_multiprocessor.h"
104 
105 #include "rnd.h"
106 #if NRND > 0 && defined(RND_COM)
107 #include <sys/rnd.h>
108 #endif
109 
110 /*
111  * Override cnmagic(9) macro before including <sys/systm.h>.
112  * We need to know if cn_check_magic triggered debugger, so set a flag.
113  * Callers of cn_check_magic must declare int cn_trapped = 0;
114  * XXX: this is *ugly*!
115  */
116 #define cn_trap()				\
117 	do {					\
118 		console_debugger();		\
119 		cn_trapped = 1;			\
120 	} while (/* CONSTCOND */ 0)
121 
122 #include <sys/param.h>
123 #include <sys/systm.h>
124 #include <sys/ioctl.h>
125 #include <sys/select.h>
126 #include <sys/tty.h>
127 #include <sys/proc.h>
128 #include <sys/conf.h>
129 #include <sys/file.h>
130 #include <sys/uio.h>
131 #include <sys/kernel.h>
132 #include <sys/syslog.h>
133 #include <sys/types.h>
134 #include <sys/device.h>
135 #include <sys/malloc.h>
136 #include <sys/timepps.h>
137 #include <sys/vnode.h>
138 #include <sys/kauth.h>
139 #include <sys/intr.h>
140 #include <sys/bus.h>
141 
142 #include <evbarm/dev/plcomreg.h>
143 #include <evbarm/dev/plcomvar.h>
144 
145 #include <dev/cons.h>
146 
147 static void plcom_enable_debugport (struct plcom_softc *);
148 
149 void	plcom_config	(struct plcom_softc *);
150 void	plcom_shutdown	(struct plcom_softc *);
151 int	plcomspeed	(long, long);
152 static	u_char	cflag2lcr (tcflag_t);
153 int	plcomparam	(struct tty *, struct termios *);
154 void	plcomstart	(struct tty *);
155 int	plcomhwiflow	(struct tty *, int);
156 
157 void	plcom_loadchannelregs (struct plcom_softc *);
158 void	plcom_hwiflow	(struct plcom_softc *);
159 void	plcom_break	(struct plcom_softc *, int);
160 void	plcom_modem	(struct plcom_softc *, int);
161 void	tiocm_to_plcom	(struct plcom_softc *, u_long, int);
162 int	plcom_to_tiocm	(struct plcom_softc *);
163 void	plcom_iflush	(struct plcom_softc *);
164 
165 int	plcom_common_getc (dev_t, bus_space_tag_t, bus_space_handle_t);
166 void	plcom_common_putc (dev_t, bus_space_tag_t, bus_space_handle_t, int);
167 
168 int	plcominit	(bus_space_tag_t, bus_addr_t, int, int, tcflag_t,
169 			    bus_space_handle_t *);
170 
171 dev_type_open(plcomopen);
172 dev_type_close(plcomclose);
173 dev_type_read(plcomread);
174 dev_type_write(plcomwrite);
175 dev_type_ioctl(plcomioctl);
176 dev_type_stop(plcomstop);
177 dev_type_tty(plcomtty);
178 dev_type_poll(plcompoll);
179 
180 int	plcomcngetc	(dev_t);
181 void	plcomcnputc	(dev_t, int);
182 void	plcomcnpollc	(dev_t, int);
183 
184 #define	integrate	static inline
185 void 	plcomsoft	(void *);
186 integrate void plcom_rxsoft	(struct plcom_softc *, struct tty *);
187 integrate void plcom_txsoft	(struct plcom_softc *, struct tty *);
188 integrate void plcom_stsoft	(struct plcom_softc *, struct tty *);
189 integrate void plcom_schedrx	(struct plcom_softc *);
190 void	plcomdiag		(void *);
191 
192 extern struct cfdriver plcom_cd;
193 
194 const struct cdevsw plcom_cdevsw = {
195 	plcomopen, plcomclose, plcomread, plcomwrite, plcomioctl,
196 	plcomstop, plcomtty, plcompoll, nommap, ttykqfilter, D_TTY
197 };
198 
199 /*
200  * Make this an option variable one can patch.
201  * But be warned:  this must be a power of 2!
202  */
203 u_int plcom_rbuf_size = PLCOM_RING_SIZE;
204 
205 /* Stop input when 3/4 of the ring is full; restart when only 1/4 is full. */
206 u_int plcom_rbuf_hiwat = (PLCOM_RING_SIZE * 1) / 4;
207 u_int plcom_rbuf_lowat = (PLCOM_RING_SIZE * 3) / 4;
208 
209 static int	plcomconsunit = -1;
210 static bus_space_tag_t plcomconstag;
211 static bus_space_handle_t plcomconsioh;
212 static int	plcomconsattached;
213 static int plcomconsrate;
214 static tcflag_t plcomconscflag;
215 static struct cnm_state plcom_cnm_state;
216 
217 static int ppscap =
218 	PPS_TSFMT_TSPEC |
219 	PPS_CAPTUREASSERT |
220 	PPS_CAPTURECLEAR |
221 #ifdef  PPS_SYNC
222 	PPS_HARDPPSONASSERT | PPS_HARDPPSONCLEAR |
223 #endif	/* PPS_SYNC */
224 	PPS_OFFSETASSERT | PPS_OFFSETCLEAR;
225 
226 #ifdef KGDB
227 #include <sys/kgdb.h>
228 
229 static int plcom_kgdb_unit;
230 static bus_space_tag_t plcom_kgdb_iot;
231 static bus_space_handle_t plcom_kgdb_ioh;
232 static int plcom_kgdb_attached;
233 
234 int	plcom_kgdb_getc (void *);
235 void	plcom_kgdb_putc (void *, int);
236 #endif /* KGDB */
237 
238 #define	PLCOMUNIT_MASK	0x7ffff
239 #define	PLCOMDIALOUT_MASK	0x80000
240 
241 #define	PLCOMUNIT(x)	(minor(x) & PLCOMUNIT_MASK)
242 #define	PLCOMDIALOUT(x)	(minor(x) & PLCOMDIALOUT_MASK)
243 
244 #define	PLCOM_ISALIVE(sc)	((sc)->enabled != 0 && \
245 				 device_is_active(&(sc)->sc_dev))
246 
247 #define	BR	BUS_SPACE_BARRIER_READ
248 #define	BW	BUS_SPACE_BARRIER_WRITE
249 #define PLCOM_BARRIER(t, h, f) bus_space_barrier((t), (h), 0, PLCOM_UART_SIZE, (f))
250 
251 #define PLCOM_LOCK(sc) simple_lock(&(sc)->sc_lock)
252 #define PLCOM_UNLOCK(sc) simple_unlock(&(sc)->sc_lock)
253 
254 int
255 plcomspeed(long speed, long frequency)
256 {
257 #define	divrnd(n, q)	(((n)*2/(q)+1)/2)	/* divide and round off */
258 
259 	int x, err;
260 
261 #if 0
262 	if (speed == 0)
263 		return 0;
264 #endif
265 	if (speed <= 0)
266 		return -1;
267 	x = divrnd(frequency / 16, speed);
268 	if (x <= 0)
269 		return -1;
270 	err = divrnd(((quad_t)frequency) * 1000 / 16, speed * x) - 1000;
271 	if (err < 0)
272 		err = -err;
273 	if (err > PLCOM_TOLERANCE)
274 		return -1;
275 	return x;
276 
277 #undef	divrnd
278 }
279 
280 #ifdef PLCOM_DEBUG
281 int	plcom_debug = 0;
282 
283 void plcomstatus (struct plcom_softc *, char *);
284 void
285 plcomstatus(struct plcom_softc *sc, char *str)
286 {
287 	struct tty *tp = sc->sc_tty;
288 
289 	printf("%s: %s %sclocal  %sdcd %sts_carr_on %sdtr %stx_stopped\n",
290 	    sc->sc_dev.dv_xname, str,
291 	    ISSET(tp->t_cflag, CLOCAL) ? "+" : "-",
292 	    ISSET(sc->sc_msr, MSR_DCD) ? "+" : "-",
293 	    ISSET(tp->t_state, TS_CARR_ON) ? "+" : "-",
294 	    ISSET(sc->sc_mcr, MCR_DTR) ? "+" : "-",
295 	    sc->sc_tx_stopped ? "+" : "-");
296 
297 	printf("%s: %s %scrtscts %scts %sts_ttstop  %srts %xrx_flags\n",
298 	    sc->sc_dev.dv_xname, str,
299 	    ISSET(tp->t_cflag, CRTSCTS) ? "+" : "-",
300 	    ISSET(sc->sc_msr, MSR_CTS) ? "+" : "-",
301 	    ISSET(tp->t_state, TS_TTSTOP) ? "+" : "-",
302 	    ISSET(sc->sc_mcr, MCR_RTS) ? "+" : "-",
303 	    sc->sc_rx_flags);
304 }
305 #endif
306 
307 int
308 plcomprobe1(bus_space_tag_t iot, bus_space_handle_t ioh)
309 {
310 	int data;
311 
312 	/* Disable the UART.  */
313 	bus_space_write_1(iot, ioh, plcom_cr, 0);
314 	/* Make sure the FIFO is off.  */
315 	bus_space_write_1(iot, ioh, plcom_lcr, LCR_8BITS);
316 	/* Disable interrupts.  */
317 	bus_space_write_1(iot, ioh, plcom_iir, 0);
318 
319 	/* Make sure we swallow anything in the receiving register.  */
320 	data = bus_space_read_1(iot, ioh, plcom_dr);
321 
322 	if (bus_space_read_1(iot, ioh, plcom_lcr) != LCR_8BITS)
323 		return 0;
324 
325 	data = bus_space_read_1(iot, ioh, plcom_fr) & (FR_RXFF | FR_RXFE);
326 
327 	if (data != FR_RXFE)
328 		return 0;
329 
330 	return 1;
331 }
332 
333 static void
334 plcom_enable_debugport(struct plcom_softc *sc)
335 {
336 	int s;
337 
338 	/* Turn on line break interrupt, set carrier. */
339 	s = splserial();
340 	PLCOM_LOCK(sc);
341 	sc->sc_cr = CR_RIE | CR_RTIE | CR_UARTEN;
342 	bus_space_write_1(sc->sc_iot, sc->sc_ioh, plcom_cr, sc->sc_cr);
343 	SET(sc->sc_mcr, MCR_DTR | MCR_RTS);
344 	/* XXX device_unit() abuse */
345 	sc->sc_set_mcr(sc->sc_set_mcr_arg, device_unit(&sc->sc_dev),
346 	    sc->sc_mcr);
347 	PLCOM_UNLOCK(sc);
348 	splx(s);
349 }
350 
351 void
352 plcom_attach_subr(struct plcom_softc *sc)
353 {
354 	int unit = sc->sc_iounit;
355 	bus_space_tag_t iot = sc->sc_iot;
356 	bus_space_handle_t ioh = sc->sc_ioh;
357 	struct tty *tp;
358 
359 	callout_init(&sc->sc_diag_callout, 0);
360 	simple_lock_init(&sc->sc_lock);
361 
362 	/* Disable interrupts before configuring the device. */
363 	sc->sc_cr = 0;
364 
365 	if (plcomconstag && unit == plcomconsunit) {
366 		plcomconsattached = 1;
367 
368 		plcomconstag = iot;
369 		plcomconsioh = ioh;
370 
371 		/* Make sure the console is always "hardwired". */
372 		delay(1000);			/* wait for output to finish */
373 		SET(sc->sc_hwflags, PLCOM_HW_CONSOLE);
374 		SET(sc->sc_swflags, TIOCFLAG_SOFTCAR);
375 		/* Must re-enable the console immediately, or we will
376 		   hang when trying to print.  */
377 		sc->sc_cr = CR_UARTEN;
378 	}
379 
380 	bus_space_write_1(iot, ioh, plcom_cr, sc->sc_cr);
381 
382 	/* The PL010 has a 16-byte fifo, but the tx interrupt triggers when
383 	   there is space for 8 more bytes.  */
384 	sc->sc_fifolen = 8;
385 	printf("\n");
386 
387 	if (ISSET(sc->sc_hwflags, PLCOM_HW_TXFIFO_DISABLE)) {
388 		sc->sc_fifolen = 1;
389 		printf("%s: txfifo disabled\n", sc->sc_dev.dv_xname);
390 	}
391 
392 	if (sc->sc_fifolen > 1)
393 		SET(sc->sc_hwflags, PLCOM_HW_FIFO);
394 
395 	tp = ttymalloc();
396 	tp->t_oproc = plcomstart;
397 	tp->t_param = plcomparam;
398 	tp->t_hwiflow = plcomhwiflow;
399 
400 	sc->sc_tty = tp;
401 	sc->sc_rbuf = malloc(plcom_rbuf_size << 1, M_DEVBUF, M_NOWAIT);
402 	sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
403 	sc->sc_rbavail = plcom_rbuf_size;
404 	if (sc->sc_rbuf == NULL) {
405 		printf("%s: unable to allocate ring buffer\n",
406 		    sc->sc_dev.dv_xname);
407 		return;
408 	}
409 	sc->sc_ebuf = sc->sc_rbuf + (plcom_rbuf_size << 1);
410 
411 	tty_attach(tp);
412 
413 	if (ISSET(sc->sc_hwflags, PLCOM_HW_CONSOLE)) {
414 		int maj;
415 
416 		/* locate the major number */
417 		maj = cdevsw_lookup_major(&plcom_cdevsw);
418 
419 		cn_tab->cn_dev = makedev(maj, device_unit(&sc->sc_dev));
420 
421 		printf("%s: console\n", sc->sc_dev.dv_xname);
422 	}
423 
424 #ifdef KGDB
425 	/*
426 	 * Allow kgdb to "take over" this port.  If this is
427 	 * the kgdb device, it has exclusive use.
428 	 */
429 	if (iot == plcom_kgdb_iot && unit == plcom_kgdb_unit) {
430 		plcom_kgdb_attached = 1;
431 
432 		SET(sc->sc_hwflags, PLCOM_HW_KGDB);
433 		printf("%s: kgdb\n", sc->sc_dev.dv_xname);
434 	}
435 #endif
436 
437 	sc->sc_si = softint_establish(SOFTINT_SERIAL, plcomsoft, sc);
438 
439 #if NRND > 0 && defined(RND_COM)
440 	rnd_attach_source(&sc->rnd_source, sc->sc_dev.dv_xname,
441 			  RND_TYPE_TTY, 0);
442 #endif
443 
444 	/* if there are no enable/disable functions, assume the device
445 	   is always enabled */
446 	if (!sc->enable)
447 		sc->enabled = 1;
448 
449 	plcom_config(sc);
450 
451 	SET(sc->sc_hwflags, PLCOM_HW_DEV_OK);
452 }
453 
454 void
455 plcom_config(struct plcom_softc *sc)
456 {
457 	bus_space_tag_t iot = sc->sc_iot;
458 	bus_space_handle_t ioh = sc->sc_ioh;
459 
460 	/* Disable interrupts before configuring the device. */
461 	sc->sc_cr = 0;
462 	bus_space_write_1(iot, ioh, plcom_cr, sc->sc_cr);
463 
464 	if (ISSET(sc->sc_hwflags, PLCOM_HW_CONSOLE|PLCOM_HW_KGDB))
465 		plcom_enable_debugport(sc);
466 }
467 
468 int
469 plcom_detach(struct device *self, int flags)
470 {
471 	struct plcom_softc *sc = (struct plcom_softc *)self;
472 	int maj, mn;
473 
474 	if (sc->sc_hwflags & (PLCOM_HW_CONSOLE|PLCOM_HW_KGDB))
475 		return EBUSY;
476 
477 	if (sc->disable != NULL && sc->enabled != 0) {
478 		(*sc->disable)(sc);
479 		sc->enabled = 0;
480 	}
481 
482 	/* locate the major number */
483 	maj = cdevsw_lookup_major(&plcom_cdevsw);
484 
485 	/* Nuke the vnodes for any open instances. */
486 	mn = device_unit(self);
487 	vdevgone(maj, mn, mn, VCHR);
488 
489 	mn |= PLCOMDIALOUT_MASK;
490 	vdevgone(maj, mn, mn, VCHR);
491 
492 	/* Free the receive buffer. */
493 	free(sc->sc_rbuf, M_DEVBUF);
494 
495 	/* Detach and free the tty. */
496 	tty_detach(sc->sc_tty);
497 	ttyfree(sc->sc_tty);
498 
499 	/* Unhook the soft interrupt handler. */
500 	softint_disestablish(sc->sc_si);
501 
502 #if NRND > 0 && defined(RND_COM)
503 	/* Unhook the entropy source. */
504 	rnd_detach_source(&sc->rnd_source);
505 #endif
506 
507 	return 0;
508 }
509 
510 int
511 plcom_activate(device_t self, enum devact act)
512 {
513 	struct plcom_softc *sc = device_private(self);
514 
515 	switch (act) {
516 	case DVACT_DEACTIVATE:
517 		sc->enabled = 0;
518 		return 0;
519 	default:
520 		return EOPNOTSUPP;
521 	}
522 }
523 
524 void
525 plcom_shutdown(struct plcom_softc *sc)
526 {
527 	struct tty *tp = sc->sc_tty;
528 	int s;
529 
530 	s = splserial();
531 	PLCOM_LOCK(sc);
532 
533 	/* If we were asserting flow control, then deassert it. */
534 	SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
535 	plcom_hwiflow(sc);
536 
537 	/* Clear any break condition set with TIOCSBRK. */
538 	plcom_break(sc, 0);
539 
540 	/* Turn off PPS capture on last close. */
541 	mutex_spin_enter(&timecounter_lock);
542 	sc->sc_ppsmask = 0;
543 	sc->ppsparam.mode = 0;
544 	mutex_spin_exit(&timecounter_lock);
545 
546 	/*
547 	 * Hang up if necessary.  Wait a bit, so the other side has time to
548 	 * notice even if we immediately open the port again.
549 	 * Avoid tsleeping above splhigh().
550 	 */
551 	if (ISSET(tp->t_cflag, HUPCL)) {
552 		plcom_modem(sc, 0);
553 		PLCOM_UNLOCK(sc);
554 		splx(s);
555 		/* XXX tsleep will only timeout */
556 		(void) tsleep(sc, TTIPRI, ttclos, hz);
557 		s = splserial();
558 		PLCOM_LOCK(sc);
559 	}
560 
561 	/* Turn off interrupts. */
562 	if (ISSET(sc->sc_hwflags, PLCOM_HW_CONSOLE))
563 		/* interrupt on break */
564 		sc->sc_cr = CR_RIE | CR_RTIE | CR_UARTEN;
565 	else
566 		sc->sc_cr = 0;
567 	bus_space_write_1(sc->sc_iot, sc->sc_ioh, plcom_cr, sc->sc_cr);
568 
569 	if (sc->disable) {
570 #ifdef DIAGNOSTIC
571 		if (!sc->enabled)
572 			panic("plcom_shutdown: not enabled?");
573 #endif
574 		(*sc->disable)(sc);
575 		sc->enabled = 0;
576 	}
577 	PLCOM_UNLOCK(sc);
578 	splx(s);
579 }
580 
581 int
582 plcomopen(dev_t dev, int flag, int mode, struct lwp *l)
583 {
584 	struct plcom_softc *sc;
585 	struct tty *tp;
586 	int s, s2;
587 	int error;
588 
589 	sc = device_lookup_private(&plcom_cd, PLCOMUNIT(dev));
590 	if (sc == NULL || !ISSET(sc->sc_hwflags, PLCOM_HW_DEV_OK) ||
591 		sc->sc_rbuf == NULL)
592 		return ENXIO;
593 
594 	if (!device_is_active(&sc->sc_dev))
595 		return ENXIO;
596 
597 #ifdef KGDB
598 	/*
599 	 * If this is the kgdb port, no other use is permitted.
600 	 */
601 	if (ISSET(sc->sc_hwflags, PLCOM_HW_KGDB))
602 		return EBUSY;
603 #endif
604 
605 	tp = sc->sc_tty;
606 
607 	if (kauth_authorize_device_tty(l->l_cred, KAUTH_DEVICE_TTY_OPEN, tp))
608 		return (EBUSY);
609 
610 	s = spltty();
611 
612 	/*
613 	 * Do the following iff this is a first open.
614 	 */
615 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
616 		struct termios t;
617 
618 		tp->t_dev = dev;
619 
620 		s2 = splserial();
621 		PLCOM_LOCK(sc);
622 
623 		if (sc->enable) {
624 			if ((*sc->enable)(sc)) {
625 				PLCOM_UNLOCK(sc);
626 				splx(s2);
627 				splx(s);
628 				printf("%s: device enable failed\n",
629 				       sc->sc_dev.dv_xname);
630 				return EIO;
631 			}
632 			sc->enabled = 1;
633 			plcom_config(sc);
634 		}
635 
636 		/* Turn on interrupts. */
637 		/* IER_ERXRDY | IER_ERLS | IER_EMSC;  */
638 		sc->sc_cr = CR_RIE | CR_RTIE | CR_MSIE | CR_UARTEN;
639 		bus_space_write_1(sc->sc_iot, sc->sc_ioh, plcom_cr, sc->sc_cr);
640 
641 		/* Fetch the current modem control status, needed later. */
642 		sc->sc_msr = bus_space_read_1(sc->sc_iot, sc->sc_ioh, plcom_fr);
643 
644 		/* Clear PPS capture state on first open. */
645 
646 		mutex_spin_enter(&timecounter_lock);
647 		sc->sc_ppsmask = 0;
648 		sc->ppsparam.mode = 0;
649 		mutex_spin_exit(&timecounter_lock);
650 
651 		PLCOM_UNLOCK(sc);
652 		splx(s2);
653 
654 		/*
655 		 * Initialize the termios status to the defaults.  Add in the
656 		 * sticky bits from TIOCSFLAGS.
657 		 */
658 		t.c_ispeed = 0;
659 		if (ISSET(sc->sc_hwflags, PLCOM_HW_CONSOLE)) {
660 			t.c_ospeed = plcomconsrate;
661 			t.c_cflag = plcomconscflag;
662 		} else {
663 			t.c_ospeed = TTYDEF_SPEED;
664 			t.c_cflag = TTYDEF_CFLAG;
665 		}
666 		if (ISSET(sc->sc_swflags, TIOCFLAG_CLOCAL))
667 			SET(t.c_cflag, CLOCAL);
668 		if (ISSET(sc->sc_swflags, TIOCFLAG_CRTSCTS))
669 			SET(t.c_cflag, CRTSCTS);
670 		if (ISSET(sc->sc_swflags, TIOCFLAG_MDMBUF))
671 			SET(t.c_cflag, MDMBUF);
672 		/* Make sure plcomparam() will do something. */
673 		tp->t_ospeed = 0;
674 		(void) plcomparam(tp, &t);
675 		tp->t_iflag = TTYDEF_IFLAG;
676 		tp->t_oflag = TTYDEF_OFLAG;
677 		tp->t_lflag = TTYDEF_LFLAG;
678 		ttychars(tp);
679 		ttsetwater(tp);
680 
681 		s2 = splserial();
682 		PLCOM_LOCK(sc);
683 
684 		/*
685 		 * Turn on DTR.  We must always do this, even if carrier is not
686 		 * present, because otherwise we'd have to use TIOCSDTR
687 		 * immediately after setting CLOCAL, which applications do not
688 		 * expect.  We always assert DTR while the device is open
689 		 * unless explicitly requested to deassert it.
690 		 */
691 		plcom_modem(sc, 1);
692 
693 		/* Clear the input ring, and unblock. */
694 		sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
695 		sc->sc_rbavail = plcom_rbuf_size;
696 		plcom_iflush(sc);
697 		CLR(sc->sc_rx_flags, RX_ANY_BLOCK);
698 		plcom_hwiflow(sc);
699 
700 #ifdef PLCOM_DEBUG
701 		if (plcom_debug)
702 			plcomstatus(sc, "plcomopen  ");
703 #endif
704 
705 		PLCOM_UNLOCK(sc);
706 		splx(s2);
707 	}
708 
709 	splx(s);
710 
711 	error = ttyopen(tp, PLCOMDIALOUT(dev), ISSET(flag, O_NONBLOCK));
712 	if (error)
713 		goto bad;
714 
715 	error = (*tp->t_linesw->l_open)(dev, tp);
716 	if (error)
717 		goto bad;
718 
719 	return 0;
720 
721 bad:
722 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
723 		/*
724 		 * We failed to open the device, and nobody else had it opened.
725 		 * Clean up the state as appropriate.
726 		 */
727 		plcom_shutdown(sc);
728 	}
729 
730 	return error;
731 }
732 
733 int
734 plcomclose(dev_t dev, int flag, int mode, struct lwp *l)
735 {
736 	struct plcom_softc *sc =
737 		device_lookup_private(&plcom_cd, PLCOMUNIT(dev));
738 	struct tty *tp = sc->sc_tty;
739 
740 	/* XXX This is for cons.c. */
741 	if (!ISSET(tp->t_state, TS_ISOPEN))
742 		return 0;
743 
744 	(*tp->t_linesw->l_close)(tp, flag);
745 	ttyclose(tp);
746 
747 	if (PLCOM_ISALIVE(sc) == 0)
748 		return 0;
749 
750 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
751 		/*
752 		 * Although we got a last close, the device may still be in
753 		 * use; e.g. if this was the dialout node, and there are still
754 		 * processes waiting for carrier on the non-dialout node.
755 		 */
756 		plcom_shutdown(sc);
757 	}
758 
759 	return 0;
760 }
761 
762 int
763 plcomread(dev_t dev, struct uio *uio, int flag)
764 {
765 	struct plcom_softc *sc =
766 		device_lookup_private(&plcom_cd, PLCOMUNIT(dev));
767 	struct tty *tp = sc->sc_tty;
768 
769 	if (PLCOM_ISALIVE(sc) == 0)
770 		return EIO;
771 
772 	return (*tp->t_linesw->l_read)(tp, uio, flag);
773 }
774 
775 int
776 plcomwrite(dev_t dev, struct uio *uio, int flag)
777 {
778 	struct plcom_softc *sc =
779 		device_lookup_private(&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_write)(tp, uio, flag);
786 }
787 
788 int
789 plcompoll(dev_t dev, int events, struct lwp *l)
790 {
791 	struct plcom_softc *sc =
792 		device_lookup_private(&plcom_cd, PLCOMUNIT(dev));
793 	struct tty *tp = sc->sc_tty;
794 
795 	if (PLCOM_ISALIVE(sc) == 0)
796 		return EIO;
797 
798 	return (*tp->t_linesw->l_poll)(tp, events, l);
799 }
800 
801 struct tty *
802 plcomtty(dev_t dev)
803 {
804 	struct plcom_softc *sc =
805 		device_lookup_private(&plcom_cd, PLCOMUNIT(dev));
806 	struct tty *tp = sc->sc_tty;
807 
808 	return tp;
809 }
810 
811 int
812 plcomioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
813 {
814 	struct plcom_softc *sc =
815 		device_lookup_private(&plcom_cd, PLCOMUNIT(dev));
816 	struct tty *tp = sc->sc_tty;
817 	int error;
818 	int s;
819 
820 	if (PLCOM_ISALIVE(sc) == 0)
821 		return EIO;
822 
823 	error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, l);
824 	if (error != EPASSTHROUGH)
825 		return error;
826 
827 	error = ttioctl(tp, cmd, data, flag, l);
828 	if (error != EPASSTHROUGH)
829 		return error;
830 
831 	error = 0;
832 
833 	s = splserial();
834 	PLCOM_LOCK(sc);
835 
836 	switch (cmd) {
837 	case TIOCSBRK:
838 		plcom_break(sc, 1);
839 		break;
840 
841 	case TIOCCBRK:
842 		plcom_break(sc, 0);
843 		break;
844 
845 	case TIOCSDTR:
846 		plcom_modem(sc, 1);
847 		break;
848 
849 	case TIOCCDTR:
850 		plcom_modem(sc, 0);
851 		break;
852 
853 	case TIOCGFLAGS:
854 		*(int *)data = sc->sc_swflags;
855 		break;
856 
857 	case TIOCSFLAGS:
858 		error = kauth_authorize_device_tty(l->l_cred,
859 		    KAUTH_DEVICE_TTY_PRIVSET, tp);
860 		if (error)
861 			break;
862 		sc->sc_swflags = *(int *)data;
863 		break;
864 
865 	case TIOCMSET:
866 	case TIOCMBIS:
867 	case TIOCMBIC:
868 		tiocm_to_plcom(sc, cmd, *(int *)data);
869 		break;
870 
871 	case TIOCMGET:
872 		*(int *)data = plcom_to_tiocm(sc);
873 		break;
874 
875 	case PPS_IOC_CREATE:
876 		break;
877 
878 	case PPS_IOC_DESTROY:
879 		break;
880 
881 	case PPS_IOC_GETPARAMS: {
882 		pps_params_t *pp;
883 		pp = (pps_params_t *)data;
884 		mutex_spin_enter(&timecounter_lock);
885 		*pp = sc->ppsparam;
886 		mutex_spin_exit(&timecounter_lock);
887 		break;
888 	}
889 
890 	case PPS_IOC_SETPARAMS: {
891 	  	pps_params_t *pp;
892 		int mode;
893 		pp = (pps_params_t *)data;
894 		mutex_spin_enter(&timecounter_lock);
895 		if (pp->mode & ~ppscap) {
896 			error = EINVAL;
897 			mutex_spin_exit(&timecounter_lock);
898 			break;
899 		}
900 		sc->ppsparam = *pp;
901 	 	/*
902 		 * Compute msr masks from user-specified timestamp state.
903 		 */
904 		mode = sc->ppsparam.mode;
905 #ifdef	PPS_SYNC
906 		if (mode & PPS_HARDPPSONASSERT) {
907 			mode |= PPS_CAPTUREASSERT;
908 			/* XXX revoke any previous HARDPPS source */
909 		}
910 		if (mode & PPS_HARDPPSONCLEAR) {
911 			mode |= PPS_CAPTURECLEAR;
912 			/* XXX revoke any previous HARDPPS source */
913 		}
914 #endif	/* PPS_SYNC */
915 		switch (mode & PPS_CAPTUREBOTH) {
916 		case 0:
917 			sc->sc_ppsmask = 0;
918 			break;
919 
920 		case PPS_CAPTUREASSERT:
921 			sc->sc_ppsmask = MSR_DCD;
922 			sc->sc_ppsassert = MSR_DCD;
923 			sc->sc_ppsclear = -1;
924 			break;
925 
926 		case PPS_CAPTURECLEAR:
927 			sc->sc_ppsmask = MSR_DCD;
928 			sc->sc_ppsassert = -1;
929 			sc->sc_ppsclear = 0;
930 			break;
931 
932 		case PPS_CAPTUREBOTH:
933 			sc->sc_ppsmask = MSR_DCD;
934 			sc->sc_ppsassert = MSR_DCD;
935 			sc->sc_ppsclear = 0;
936 			break;
937 
938 		default:
939 			error = EINVAL;
940 			break;
941 		}
942 		mutex_spin_exit(&timecounter_lock);
943 		break;
944 	}
945 
946 	case PPS_IOC_GETCAP:
947 		*(int*)data = ppscap;
948 		break;
949 
950 	case PPS_IOC_FETCH: {
951 		pps_info_t *pi;
952 		pi = (pps_info_t *)data;
953 		mutex_spin_enter(&timecounter_lock);
954 		*pi = sc->ppsinfo;
955 		mutex_spin_exit(&timecounter_lock);
956 		break;
957 	}
958 
959 	case TIOCDCDTIMESTAMP:	/* XXX old, overloaded  API used by xntpd v3 */
960 		/*
961 		 * Some GPS clocks models use the falling rather than
962 		 * rising edge as the on-the-second signal.
963 		 * The old API has no way to specify PPS polarity.
964 		 */
965 		mutex_spin_enter(&timecounter_lock);
966 		sc->sc_ppsmask = MSR_DCD;
967 #ifndef PPS_TRAILING_EDGE
968 		sc->sc_ppsassert = MSR_DCD;
969 		sc->sc_ppsclear = -1;
970 		TIMESPEC_TO_TIMEVAL((struct timeval *)data,
971 		    &sc->ppsinfo.assert_timestamp);
972 #else
973 		sc->sc_ppsassert = -1
974 		sc->sc_ppsclear = 0;
975 		TIMESPEC_TO_TIMEVAL((struct timeval *)data,
976 		    &sc->ppsinfo.clear_timestamp);
977 #endif
978 		mutex_spin_exit(&timecounter_lock);
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 	softint_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 =
1144 		device_lookup_private(&plcom_cd, PLCOMUNIT(tp->t_dev));
1145 	int ospeed;
1146 	u_char lcr;
1147 	int s;
1148 
1149 	if (PLCOM_ISALIVE(sc) == 0)
1150 		return EIO;
1151 
1152 	ospeed = plcomspeed(t->c_ospeed, sc->sc_frequency);
1153 
1154 	/* Check requested parameters. */
1155 	if (ospeed < 0)
1156 		return EINVAL;
1157 	if (t->c_ispeed && t->c_ispeed != t->c_ospeed)
1158 		return EINVAL;
1159 
1160 	/*
1161 	 * For the console, always force CLOCAL and !HUPCL, so that the port
1162 	 * is always active.
1163 	 */
1164 	if (ISSET(sc->sc_swflags, TIOCFLAG_SOFTCAR) ||
1165 	    ISSET(sc->sc_hwflags, PLCOM_HW_CONSOLE)) {
1166 		SET(t->c_cflag, CLOCAL);
1167 		CLR(t->c_cflag, HUPCL);
1168 	}
1169 
1170 	/*
1171 	 * If there were no changes, don't do anything.  This avoids dropping
1172 	 * input and improves performance when all we did was frob things like
1173 	 * VMIN and VTIME.
1174 	 */
1175 	if (tp->t_ospeed == t->c_ospeed &&
1176 	    tp->t_cflag == t->c_cflag)
1177 		return 0;
1178 
1179 	lcr = ISSET(sc->sc_lcr, LCR_BRK) | cflag2lcr(t->c_cflag);
1180 
1181 	s = splserial();
1182 	PLCOM_LOCK(sc);
1183 
1184 	sc->sc_lcr = lcr;
1185 
1186 	/*
1187 	 * PL010 has a fixed-length FIFO trigger point.
1188 	 */
1189 	if (ISSET(sc->sc_hwflags, PLCOM_HW_FIFO))
1190 		sc->sc_fifo = 1;
1191 	else
1192 		sc->sc_fifo = 0;
1193 
1194 	if (sc->sc_fifo)
1195 		SET(sc->sc_lcr, LCR_FEN);
1196 
1197 	/*
1198 	 * If we're not in a mode that assumes a connection is present, then
1199 	 * ignore carrier changes.
1200 	 */
1201 	if (ISSET(t->c_cflag, CLOCAL | MDMBUF))
1202 		sc->sc_msr_dcd = 0;
1203 	else
1204 		sc->sc_msr_dcd = MSR_DCD;
1205 	/*
1206 	 * Set the flow control pins depending on the current flow control
1207 	 * mode.
1208 	 */
1209 	if (ISSET(t->c_cflag, CRTSCTS)) {
1210 		sc->sc_mcr_dtr = MCR_DTR;
1211 		sc->sc_mcr_rts = MCR_RTS;
1212 		sc->sc_msr_cts = MSR_CTS;
1213 	} else if (ISSET(t->c_cflag, MDMBUF)) {
1214 		/*
1215 		 * For DTR/DCD flow control, make sure we don't toggle DTR for
1216 		 * carrier detection.
1217 		 */
1218 		sc->sc_mcr_dtr = 0;
1219 		sc->sc_mcr_rts = MCR_DTR;
1220 		sc->sc_msr_cts = MSR_DCD;
1221 	} else {
1222 		/*
1223 		 * If no flow control, then always set RTS.  This will make
1224 		 * the other side happy if it mistakenly thinks we're doing
1225 		 * RTS/CTS flow control.
1226 		 */
1227 		sc->sc_mcr_dtr = MCR_DTR | MCR_RTS;
1228 		sc->sc_mcr_rts = 0;
1229 		sc->sc_msr_cts = 0;
1230 		if (ISSET(sc->sc_mcr, MCR_DTR))
1231 			SET(sc->sc_mcr, MCR_RTS);
1232 		else
1233 			CLR(sc->sc_mcr, MCR_RTS);
1234 	}
1235 	sc->sc_msr_mask = sc->sc_msr_cts | sc->sc_msr_dcd;
1236 
1237 #if 0
1238 	if (ospeed == 0)
1239 		CLR(sc->sc_mcr, sc->sc_mcr_dtr);
1240 	else
1241 		SET(sc->sc_mcr, sc->sc_mcr_dtr);
1242 #endif
1243 
1244 	sc->sc_dlbl = ospeed;
1245 	sc->sc_dlbh = ospeed >> 8;
1246 
1247 	/* And copy to tty. */
1248 	tp->t_ispeed = 0;
1249 	tp->t_ospeed = t->c_ospeed;
1250 	tp->t_cflag = t->c_cflag;
1251 
1252 	if (!sc->sc_heldchange) {
1253 		if (sc->sc_tx_busy) {
1254 			sc->sc_heldtbc = sc->sc_tbc;
1255 			sc->sc_tbc = 0;
1256 			sc->sc_heldchange = 1;
1257 		} else
1258 			plcom_loadchannelregs(sc);
1259 	}
1260 
1261 	if (!ISSET(t->c_cflag, CHWFLOW)) {
1262 		/* Disable the high water mark. */
1263 		sc->sc_r_hiwat = 0;
1264 		sc->sc_r_lowat = 0;
1265 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
1266 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1267 			plcom_schedrx(sc);
1268 		}
1269 		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED)) {
1270 			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED);
1271 			plcom_hwiflow(sc);
1272 		}
1273 	} else {
1274 		sc->sc_r_hiwat = plcom_rbuf_hiwat;
1275 		sc->sc_r_lowat = plcom_rbuf_lowat;
1276 	}
1277 
1278 	PLCOM_UNLOCK(sc);
1279 	splx(s);
1280 
1281 	/*
1282 	 * Update the tty layer's idea of the carrier bit, in case we changed
1283 	 * CLOCAL or MDMBUF.  We don't hang up here; we only do that by
1284 	 * explicit request.
1285 	 */
1286 	(void) (*tp->t_linesw->l_modem)(tp, ISSET(sc->sc_msr, MSR_DCD));
1287 
1288 #ifdef PLCOM_DEBUG
1289 	if (plcom_debug)
1290 		plcomstatus(sc, "plcomparam ");
1291 #endif
1292 
1293 	if (!ISSET(t->c_cflag, CHWFLOW)) {
1294 		if (sc->sc_tx_stopped) {
1295 			sc->sc_tx_stopped = 0;
1296 			plcomstart(tp);
1297 		}
1298 	}
1299 
1300 	return 0;
1301 }
1302 
1303 void
1304 plcom_iflush(struct plcom_softc *sc)
1305 {
1306 	bus_space_tag_t iot = sc->sc_iot;
1307 	bus_space_handle_t ioh = sc->sc_ioh;
1308 #ifdef DIAGNOSTIC
1309 	int reg;
1310 #endif
1311 	int timo;
1312 
1313 #ifdef DIAGNOSTIC
1314 	reg = 0xffff;
1315 #endif
1316 	timo = 50000;
1317 	/* flush any pending I/O */
1318 	while (! ISSET(bus_space_read_1(iot, ioh, plcom_fr), FR_RXFE)
1319 	    && --timo)
1320 #ifdef DIAGNOSTIC
1321 		reg =
1322 #else
1323 		    (void)
1324 #endif
1325 		    bus_space_read_1(iot, ioh, plcom_dr);
1326 #ifdef DIAGNOSTIC
1327 	if (!timo)
1328 		printf("%s: plcom_iflush timeout %02x\n", sc->sc_dev.dv_xname,
1329 		       reg);
1330 #endif
1331 }
1332 
1333 void
1334 plcom_loadchannelregs(struct plcom_softc *sc)
1335 {
1336 	bus_space_tag_t iot = sc->sc_iot;
1337 	bus_space_handle_t ioh = sc->sc_ioh;
1338 
1339 	/* XXXXX necessary? */
1340 	plcom_iflush(sc);
1341 
1342 	bus_space_write_1(iot, ioh, plcom_cr, 0);
1343 
1344 	bus_space_write_1(iot, ioh, plcom_dlbl, sc->sc_dlbl);
1345 	bus_space_write_1(iot, ioh, plcom_dlbh, sc->sc_dlbh);
1346 	bus_space_write_1(iot, ioh, plcom_lcr, sc->sc_lcr);
1347 	/* XXX device_unit() abuse */
1348 	sc->sc_set_mcr(sc->sc_set_mcr_arg, device_unit(&sc->sc_dev),
1349 	    sc->sc_mcr_active = sc->sc_mcr);
1350 
1351 	bus_space_write_1(iot, ioh, plcom_cr, sc->sc_cr);
1352 }
1353 
1354 int
1355 plcomhwiflow(struct tty *tp, int block)
1356 {
1357 	struct plcom_softc *sc =
1358 		device_lookup_private(&plcom_cd, PLCOMUNIT(tp->t_dev));
1359 	int s;
1360 
1361 	if (PLCOM_ISALIVE(sc) == 0)
1362 		return 0;
1363 
1364 	if (sc->sc_mcr_rts == 0)
1365 		return 0;
1366 
1367 	s = splserial();
1368 	PLCOM_LOCK(sc);
1369 
1370 	if (block) {
1371 		if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1372 			SET(sc->sc_rx_flags, RX_TTY_BLOCKED);
1373 			plcom_hwiflow(sc);
1374 		}
1375 	} else {
1376 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
1377 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1378 			plcom_schedrx(sc);
1379 		}
1380 		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1381 			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED);
1382 			plcom_hwiflow(sc);
1383 		}
1384 	}
1385 
1386 	PLCOM_UNLOCK(sc);
1387 	splx(s);
1388 	return 1;
1389 }
1390 
1391 /*
1392  * (un)block input via hw flowcontrol
1393  */
1394 void
1395 plcom_hwiflow(struct plcom_softc *sc)
1396 {
1397 	if (sc->sc_mcr_rts == 0)
1398 		return;
1399 
1400 	if (ISSET(sc->sc_rx_flags, RX_ANY_BLOCK)) {
1401 		CLR(sc->sc_mcr, sc->sc_mcr_rts);
1402 		CLR(sc->sc_mcr_active, sc->sc_mcr_rts);
1403 	} else {
1404 		SET(sc->sc_mcr, sc->sc_mcr_rts);
1405 		SET(sc->sc_mcr_active, sc->sc_mcr_rts);
1406 	}
1407 	/* XXX device_unit() abuse */
1408 	sc->sc_set_mcr(sc->sc_set_mcr_arg, device_unit(&sc->sc_dev),
1409 	    sc->sc_mcr_active);
1410 }
1411 
1412 
1413 void
1414 plcomstart(struct tty *tp)
1415 {
1416 	struct plcom_softc *sc =
1417 		device_lookup_private(&plcom_cd, PLCOMUNIT(tp->t_dev));
1418 	bus_space_tag_t iot = sc->sc_iot;
1419 	bus_space_handle_t ioh = sc->sc_ioh;
1420 	int s;
1421 
1422 	if (PLCOM_ISALIVE(sc) == 0)
1423 		return;
1424 
1425 	s = spltty();
1426 	if (ISSET(tp->t_state, TS_BUSY | TS_TIMEOUT | TS_TTSTOP))
1427 		goto out;
1428 	if (sc->sc_tx_stopped)
1429 		goto out;
1430 
1431 	if (!ttypull(tp))
1432 		goto out;
1433 
1434 	/* Grab the first contiguous region of buffer space. */
1435 	{
1436 		u_char *tba;
1437 		int tbc;
1438 
1439 		tba = tp->t_outq.c_cf;
1440 		tbc = ndqb(&tp->t_outq, 0);
1441 
1442 		(void)splserial();
1443 		PLCOM_LOCK(sc);
1444 
1445 		sc->sc_tba = tba;
1446 		sc->sc_tbc = tbc;
1447 	}
1448 
1449 	SET(tp->t_state, TS_BUSY);
1450 	sc->sc_tx_busy = 1;
1451 
1452 	/* Enable transmit completion interrupts if necessary. */
1453 	if (!ISSET(sc->sc_cr, CR_TIE)) {
1454 		SET(sc->sc_cr, CR_TIE);
1455 		bus_space_write_1(iot, ioh, plcom_cr, sc->sc_cr);
1456 	}
1457 
1458 	/* Output the first chunk of the contiguous buffer. */
1459 	{
1460 		int n;
1461 
1462 		n = sc->sc_tbc;
1463 		if (n > sc->sc_fifolen)
1464 			n = sc->sc_fifolen;
1465 		bus_space_write_multi_1(iot, ioh, plcom_dr, sc->sc_tba, n);
1466 		sc->sc_tbc -= n;
1467 		sc->sc_tba += n;
1468 	}
1469 	PLCOM_UNLOCK(sc);
1470 out:
1471 	splx(s);
1472 	return;
1473 }
1474 
1475 /*
1476  * Stop output on a line.
1477  */
1478 void
1479 plcomstop(struct tty *tp, int flag)
1480 {
1481 	struct plcom_softc *sc =
1482 		device_lookup_private(&plcom_cd, PLCOMUNIT(tp->t_dev));
1483 	int s;
1484 
1485 	s = splserial();
1486 	PLCOM_LOCK(sc);
1487 	if (ISSET(tp->t_state, TS_BUSY)) {
1488 		/* Stop transmitting at the next chunk. */
1489 		sc->sc_tbc = 0;
1490 		sc->sc_heldtbc = 0;
1491 		if (!ISSET(tp->t_state, TS_TTSTOP))
1492 			SET(tp->t_state, TS_FLUSH);
1493 	}
1494 	PLCOM_UNLOCK(sc);
1495 	splx(s);
1496 }
1497 
1498 void
1499 plcomdiag(void *arg)
1500 {
1501 	struct plcom_softc *sc = arg;
1502 	int overflows, floods;
1503 	int s;
1504 
1505 	s = splserial();
1506 	PLCOM_LOCK(sc);
1507 	overflows = sc->sc_overflows;
1508 	sc->sc_overflows = 0;
1509 	floods = sc->sc_floods;
1510 	sc->sc_floods = 0;
1511 	sc->sc_errors = 0;
1512 	PLCOM_UNLOCK(sc);
1513 	splx(s);
1514 
1515 	log(LOG_WARNING, "%s: %d silo overflow%s, %d ibuf flood%s\n",
1516 	    sc->sc_dev.dv_xname,
1517 	    overflows, overflows == 1 ? "" : "s",
1518 	    floods, floods == 1 ? "" : "s");
1519 }
1520 
1521 integrate void
1522 plcom_rxsoft(struct plcom_softc *sc, struct tty *tp)
1523 {
1524 	int (*rint) (int, struct tty *) = tp->t_linesw->l_rint;
1525 	u_char *get, *end;
1526 	u_int cc, scc;
1527 	u_char rsr;
1528 	int code;
1529 	int s;
1530 
1531 	end = sc->sc_ebuf;
1532 	get = sc->sc_rbget;
1533 	scc = cc = plcom_rbuf_size - sc->sc_rbavail;
1534 
1535 	if (cc == plcom_rbuf_size) {
1536 		sc->sc_floods++;
1537 		if (sc->sc_errors++ == 0)
1538 			callout_reset(&sc->sc_diag_callout, 60 * hz,
1539 			    plcomdiag, sc);
1540 	}
1541 
1542 	while (cc) {
1543 		code = get[0];
1544 		rsr = get[1];
1545 		if (ISSET(rsr, RSR_OE | RSR_BE | RSR_FE | RSR_PE)) {
1546 			if (ISSET(rsr, RSR_OE)) {
1547 				sc->sc_overflows++;
1548 				if (sc->sc_errors++ == 0)
1549 					callout_reset(&sc->sc_diag_callout,
1550 					    60 * hz, plcomdiag, sc);
1551 			}
1552 			if (ISSET(rsr, RSR_BE | RSR_FE))
1553 				SET(code, TTY_FE);
1554 			if (ISSET(rsr, RSR_PE))
1555 				SET(code, TTY_PE);
1556 		}
1557 		if ((*rint)(code, tp) == -1) {
1558 			/*
1559 			 * The line discipline's buffer is out of space.
1560 			 */
1561 			if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1562 				/*
1563 				 * We're either not using flow control, or the
1564 				 * line discipline didn't tell us to block for
1565 				 * some reason.  Either way, we have no way to
1566 				 * know when there's more space available, so
1567 				 * just drop the rest of the data.
1568 				 */
1569 				get += cc << 1;
1570 				if (get >= end)
1571 					get -= plcom_rbuf_size << 1;
1572 				cc = 0;
1573 			} else {
1574 				/*
1575 				 * Don't schedule any more receive processing
1576 				 * until the line discipline tells us there's
1577 				 * space available (through plcomhwiflow()).
1578 				 * Leave the rest of the data in the input
1579 				 * buffer.
1580 				 */
1581 				SET(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1582 			}
1583 			break;
1584 		}
1585 		get += 2;
1586 		if (get >= end)
1587 			get = sc->sc_rbuf;
1588 		cc--;
1589 	}
1590 
1591 	if (cc != scc) {
1592 		sc->sc_rbget = get;
1593 		s = splserial();
1594 		PLCOM_LOCK(sc);
1595 
1596 		cc = sc->sc_rbavail += scc - cc;
1597 		/* Buffers should be ok again, release possible block. */
1598 		if (cc >= sc->sc_r_lowat) {
1599 			if (ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
1600 				CLR(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
1601 				SET(sc->sc_cr, CR_RIE | CR_RTIE);
1602 				bus_space_write_1(sc->sc_iot, sc->sc_ioh, plcom_cr, sc->sc_cr);
1603 			}
1604 			if (ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED)) {
1605 				CLR(sc->sc_rx_flags, RX_IBUF_BLOCKED);
1606 				plcom_hwiflow(sc);
1607 			}
1608 		}
1609 		PLCOM_UNLOCK(sc);
1610 		splx(s);
1611 	}
1612 }
1613 
1614 integrate void
1615 plcom_txsoft(struct plcom_softc *sc, struct tty *tp)
1616 {
1617 
1618 	CLR(tp->t_state, TS_BUSY);
1619 	if (ISSET(tp->t_state, TS_FLUSH))
1620 		CLR(tp->t_state, TS_FLUSH);
1621 	else
1622 		ndflush(&tp->t_outq, (int)(sc->sc_tba - tp->t_outq.c_cf));
1623 	(*tp->t_linesw->l_start)(tp);
1624 }
1625 
1626 integrate void
1627 plcom_stsoft(struct plcom_softc *sc, struct tty *tp)
1628 {
1629 	u_char msr, delta;
1630 	int s;
1631 
1632 	s = splserial();
1633 	PLCOM_LOCK(sc);
1634 	msr = sc->sc_msr;
1635 	delta = sc->sc_msr_delta;
1636 	sc->sc_msr_delta = 0;
1637 	PLCOM_UNLOCK(sc);
1638 	splx(s);
1639 
1640 	if (ISSET(delta, sc->sc_msr_dcd)) {
1641 		/*
1642 		 * Inform the tty layer that carrier detect changed.
1643 		 */
1644 		(void) (*tp->t_linesw->l_modem)(tp, ISSET(msr, MSR_DCD));
1645 	}
1646 
1647 	if (ISSET(delta, sc->sc_msr_cts)) {
1648 		/* Block or unblock output according to flow control. */
1649 		if (ISSET(msr, sc->sc_msr_cts)) {
1650 			sc->sc_tx_stopped = 0;
1651 			(*tp->t_linesw->l_start)(tp);
1652 		} else {
1653 			sc->sc_tx_stopped = 1;
1654 		}
1655 	}
1656 
1657 #ifdef PLCOM_DEBUG
1658 	if (plcom_debug)
1659 		plcomstatus(sc, "plcom_stsoft");
1660 #endif
1661 }
1662 
1663 void
1664 plcomsoft(void *arg)
1665 {
1666 	struct plcom_softc *sc = arg;
1667 	struct tty *tp;
1668 
1669 	if (PLCOM_ISALIVE(sc) == 0)
1670 		return;
1671 
1672 	tp = sc->sc_tty;
1673 
1674 	if (sc->sc_rx_ready) {
1675 		sc->sc_rx_ready = 0;
1676 		plcom_rxsoft(sc, tp);
1677 	}
1678 
1679 	if (sc->sc_st_check) {
1680 		sc->sc_st_check = 0;
1681 		plcom_stsoft(sc, tp);
1682 	}
1683 
1684 	if (sc->sc_tx_done) {
1685 		sc->sc_tx_done = 0;
1686 		plcom_txsoft(sc, tp);
1687 	}
1688 }
1689 
1690 int
1691 plcomintr(void *arg)
1692 {
1693 	struct plcom_softc *sc = arg;
1694 	bus_space_tag_t iot = sc->sc_iot;
1695 	bus_space_handle_t ioh = sc->sc_ioh;
1696 	u_char *put, *end;
1697 	u_int cc;
1698 	u_char rsr, iir;
1699 
1700 	if (PLCOM_ISALIVE(sc) == 0)
1701 		return 0;
1702 
1703 	PLCOM_LOCK(sc);
1704 	iir = bus_space_read_1(iot, ioh, plcom_iir);
1705 	if (! ISSET(iir, IIR_IMASK)) {
1706 		PLCOM_UNLOCK(sc);
1707 		return 0;
1708 	}
1709 
1710 	end = sc->sc_ebuf;
1711 	put = sc->sc_rbput;
1712 	cc = sc->sc_rbavail;
1713 
1714 	do {
1715 		u_char	msr, delta, fr;
1716 
1717 		fr = bus_space_read_1(iot, ioh, plcom_fr);
1718 
1719 		if (!ISSET(fr, FR_RXFE) &&
1720 		    !ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
1721 			while (cc > 0) {
1722 				int cn_trapped = 0;
1723 				put[0] = bus_space_read_1(iot, ioh,
1724 				    plcom_dr);
1725 				rsr = bus_space_read_1(iot, ioh, plcom_rsr);
1726 				/* Clear any error status.  */
1727 				if (ISSET(rsr,
1728 				    (RSR_BE | RSR_OE | RSR_PE | RSR_FE)))
1729 					bus_space_write_1(iot, ioh, plcom_ecr,
1730 					    0);
1731 				if (ISSET(rsr, RSR_BE)) {
1732 					cn_trapped = 0;
1733 					cn_check_magic(sc->sc_tty->t_dev,
1734 					    CNC_BREAK, plcom_cnm_state);
1735 					if (cn_trapped)
1736 						continue;
1737 #if defined(KGDB)
1738 					if (ISSET(sc->sc_hwflags,
1739 					    PLCOM_HW_KGDB)) {
1740 						kgdb_connect(1);
1741 						continue;
1742 					}
1743 #endif
1744 				}
1745 
1746 				put[1] = rsr;
1747 				cn_trapped = 0;
1748 				cn_check_magic(sc->sc_tty->t_dev,
1749 					       put[0], plcom_cnm_state);
1750 				if (cn_trapped) {
1751 					fr = bus_space_read_1(iot, ioh,
1752 					    plcom_fr);
1753 					if (ISSET(fr, FR_RXFE))
1754 						break;
1755 
1756 					continue;
1757 				}
1758 				put += 2;
1759 				if (put >= end)
1760 					put = sc->sc_rbuf;
1761 				cc--;
1762 
1763 				fr = bus_space_read_1(iot, ioh, plcom_fr);
1764 				if (ISSET(fr, FR_RXFE))
1765 					break;
1766 			}
1767 
1768 			/*
1769 			 * Current string of incoming characters ended because
1770 			 * no more data was available or we ran out of space.
1771 			 * Schedule a receive event if any data was received.
1772 			 * If we're out of space, turn off receive interrupts.
1773 			 */
1774 			sc->sc_rbput = put;
1775 			sc->sc_rbavail = cc;
1776 			if (!ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED))
1777 				sc->sc_rx_ready = 1;
1778 
1779 			/*
1780 			 * See if we are in danger of overflowing a buffer. If
1781 			 * so, use hardware flow control to ease the pressure.
1782 			 */
1783 			if (!ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED) &&
1784 			    cc < sc->sc_r_hiwat) {
1785 				SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
1786 				plcom_hwiflow(sc);
1787 			}
1788 
1789 			/*
1790 			 * If we're out of space, disable receive interrupts
1791 			 * until the queue has drained a bit.
1792 			 */
1793 			if (!cc) {
1794 				SET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
1795 				CLR(sc->sc_cr, CR_RIE | CR_RTIE);
1796 				bus_space_write_1(iot, ioh, plcom_cr,
1797 				    sc->sc_cr);
1798 			}
1799 		} else {
1800 			if (ISSET(iir, IIR_RIS)) {
1801 				bus_space_write_1(iot, ioh, plcom_cr, 0);
1802 				delay(10);
1803 				bus_space_write_1(iot, ioh, plcom_cr,
1804 				    sc->sc_cr);
1805 				continue;
1806 			}
1807 		}
1808 
1809 		msr = bus_space_read_1(iot, ioh, plcom_fr);
1810 		delta = msr ^ sc->sc_msr;
1811 		sc->sc_msr = msr;
1812 		/* Clear any pending modem status interrupt.  */
1813 		if (iir & IIR_MIS)
1814 			bus_space_write_1(iot, ioh, plcom_icr, 0);
1815 		/*
1816 		 * Pulse-per-second (PSS) signals on edge of DCD?
1817 		 * Process these even if line discipline is ignoring DCD.
1818 		 */
1819 		if (delta & sc->sc_ppsmask) {
1820 			struct timeval tv;
1821 			mutex_spin_enter(&timecounter_lock);
1822 		    	if ((msr & sc->sc_ppsmask) == sc->sc_ppsassert) {
1823 				/* XXX nanotime() */
1824 				microtime(&tv);
1825 				TIMEVAL_TO_TIMESPEC(&tv,
1826 				    &sc->ppsinfo.assert_timestamp);
1827 				if (sc->ppsparam.mode & PPS_OFFSETASSERT) {
1828 					timespecadd(&sc->ppsinfo.assert_timestamp,
1829 					    &sc->ppsparam.assert_offset,
1830 						    &sc->ppsinfo.assert_timestamp);
1831 				}
1832 
1833 #ifdef PPS_SYNC
1834 				if (sc->ppsparam.mode & PPS_HARDPPSONASSERT)
1835 					hardpps(&tv, tv.tv_usec);
1836 #endif
1837 				sc->ppsinfo.assert_sequence++;
1838 				sc->ppsinfo.current_mode = sc->ppsparam.mode;
1839 
1840 			} else if ((msr & sc->sc_ppsmask) == sc->sc_ppsclear) {
1841 				/* XXX nanotime() */
1842 				microtime(&tv);
1843 				TIMEVAL_TO_TIMESPEC(&tv,
1844 				    &sc->ppsinfo.clear_timestamp);
1845 				if (sc->ppsparam.mode & PPS_OFFSETCLEAR) {
1846 					timespecadd(&sc->ppsinfo.clear_timestamp,
1847 					    &sc->ppsparam.clear_offset,
1848 					    &sc->ppsinfo.clear_timestamp);
1849 				}
1850 
1851 #ifdef PPS_SYNC
1852 				if (sc->ppsparam.mode & PPS_HARDPPSONCLEAR)
1853 					hardpps(&tv, tv.tv_usec);
1854 #endif
1855 				sc->ppsinfo.clear_sequence++;
1856 				sc->ppsinfo.current_mode = sc->ppsparam.mode;
1857 			}
1858 			mutex_spin_exit(&timecounter_lock);
1859 		}
1860 
1861 		/*
1862 		 * Process normal status changes
1863 		 */
1864 		if (ISSET(delta, sc->sc_msr_mask)) {
1865 			SET(sc->sc_msr_delta, delta);
1866 
1867 			/*
1868 			 * Stop output immediately if we lose the output
1869 			 * flow control signal or carrier detect.
1870 			 */
1871 			if (ISSET(~msr, sc->sc_msr_mask)) {
1872 				sc->sc_tbc = 0;
1873 				sc->sc_heldtbc = 0;
1874 #ifdef PLCOM_DEBUG
1875 				if (plcom_debug)
1876 					plcomstatus(sc, "plcomintr  ");
1877 #endif
1878 			}
1879 
1880 			sc->sc_st_check = 1;
1881 		}
1882 
1883 		/*
1884 		 * Done handling any receive interrupts. See if data
1885 		 * can be * transmitted as well. Schedule tx done
1886 		 * event if no data left * and tty was marked busy.
1887 		 */
1888 		if (ISSET(iir, IIR_TIS)) {
1889 			/*
1890 			 * If we've delayed a parameter change, do it
1891 			 * now, and restart * output.
1892 			 */
1893 			if (sc->sc_heldchange) {
1894 				plcom_loadchannelregs(sc);
1895 				sc->sc_heldchange = 0;
1896 				sc->sc_tbc = sc->sc_heldtbc;
1897 				sc->sc_heldtbc = 0;
1898 			}
1899 
1900 			/*
1901 			 * Output the next chunk of the contiguous
1902 			 * buffer, if any.
1903 			 */
1904 			if (sc->sc_tbc > 0) {
1905 				int n;
1906 
1907 				n = sc->sc_tbc;
1908 				if (n > sc->sc_fifolen)
1909 					n = sc->sc_fifolen;
1910 				bus_space_write_multi_1(iot, ioh, plcom_dr,
1911 				    sc->sc_tba, n);
1912 				sc->sc_tbc -= n;
1913 				sc->sc_tba += n;
1914 			} else {
1915 				/*
1916 				 * Disable transmit plcompletion
1917 				 * interrupts if necessary.
1918 				 */
1919 				if (ISSET(sc->sc_cr, CR_TIE)) {
1920 					CLR(sc->sc_cr, CR_TIE);
1921 					bus_space_write_1(iot, ioh, plcom_cr,
1922 					    sc->sc_cr);
1923 				}
1924 				if (sc->sc_tx_busy) {
1925 					sc->sc_tx_busy = 0;
1926 					sc->sc_tx_done = 1;
1927 				}
1928 			}
1929 		}
1930 	} while (ISSET((iir = bus_space_read_1(iot, ioh, plcom_iir)),
1931 	    IIR_IMASK));
1932 
1933 	PLCOM_UNLOCK(sc);
1934 
1935 	/* Wake up the poller. */
1936 	softint_schedule(sc->sc_si);
1937 
1938 #if NRND > 0 && defined(RND_COM)
1939 	rnd_add_uint32(&sc->rnd_source, iir | rsr);
1940 #endif
1941 
1942 	return 1;
1943 }
1944 
1945 /*
1946  * The following functions are polled getc and putc routines, shared
1947  * by the console and kgdb glue.
1948  *
1949  * The read-ahead code is so that you can detect pending in-band
1950  * cn_magic in polled mode while doing output rather than having to
1951  * wait until the kernel decides it needs input.
1952  */
1953 
1954 #define MAX_READAHEAD	20
1955 static int plcom_readahead[MAX_READAHEAD];
1956 static int plcom_readaheadcount = 0;
1957 
1958 int
1959 plcom_common_getc(dev_t dev, bus_space_tag_t iot, bus_space_handle_t ioh)
1960 {
1961 	int s = splserial();
1962 	u_char stat, c;
1963 
1964 	/* got a character from reading things earlier */
1965 	if (plcom_readaheadcount > 0) {
1966 		int i;
1967 
1968 		c = plcom_readahead[0];
1969 		for (i = 1; i < plcom_readaheadcount; i++) {
1970 			plcom_readahead[i-1] = plcom_readahead[i];
1971 		}
1972 		plcom_readaheadcount--;
1973 		splx(s);
1974 		return c;
1975 	}
1976 
1977 	/* block until a character becomes available */
1978 	while (ISSET(stat = bus_space_read_1(iot, ioh, plcom_fr), FR_RXFE))
1979 		;
1980 
1981 	c = bus_space_read_1(iot, ioh, plcom_dr);
1982 	stat = bus_space_read_1(iot, ioh, plcom_iir);
1983 	{
1984 		int cn_trapped = 0; /* unused */
1985 #ifdef DDB
1986 		extern int db_active;
1987 		if (!db_active)
1988 #endif
1989 			cn_check_magic(dev, c, plcom_cnm_state);
1990 	}
1991 	splx(s);
1992 	return c;
1993 }
1994 
1995 void
1996 plcom_common_putc(dev_t dev, bus_space_tag_t iot, bus_space_handle_t ioh,
1997     int c)
1998 {
1999 	int s = splserial();
2000 	int timo;
2001 
2002 	int cin, stat;
2003 	if (plcom_readaheadcount < MAX_READAHEAD
2004 	     && !ISSET(stat = bus_space_read_1(iot, ioh, plcom_fr), FR_RXFE)) {
2005 		int cn_trapped = 0;
2006 		cin = bus_space_read_1(iot, ioh, plcom_dr);
2007 		stat = bus_space_read_1(iot, ioh, plcom_iir);
2008 		cn_check_magic(dev, cin, plcom_cnm_state);
2009 		plcom_readahead[plcom_readaheadcount++] = cin;
2010 	}
2011 
2012 	/* wait for any pending transmission to finish */
2013 	timo = 150000;
2014 	while (!ISSET(bus_space_read_1(iot, ioh, plcom_fr), FR_TXFE) && --timo)
2015 		continue;
2016 
2017 	bus_space_write_1(iot, ioh, plcom_dr, c);
2018 	PLCOM_BARRIER(iot, ioh, BR | BW);
2019 
2020 	/* wait for this transmission to complete */
2021 	timo = 1500000;
2022 	while (!ISSET(bus_space_read_1(iot, ioh, plcom_fr), FR_TXFE) && --timo)
2023 		continue;
2024 
2025 	splx(s);
2026 }
2027 
2028 /*
2029  * Initialize UART for use as console or KGDB line.
2030  */
2031 int
2032 plcominit(bus_space_tag_t iot, bus_addr_t iobase, int rate, int frequency,
2033     tcflag_t cflag, bus_space_handle_t *iohp)
2034 {
2035 	bus_space_handle_t ioh;
2036 
2037 	if (bus_space_map(iot, iobase, PLCOM_UART_SIZE, 0, &ioh))
2038 		return ENOMEM; /* ??? */
2039 
2040 	rate = plcomspeed(rate, frequency);
2041 	bus_space_write_1(iot, ioh, plcom_cr, 0);
2042 	bus_space_write_1(iot, ioh, plcom_dlbl, rate);
2043 	bus_space_write_1(iot, ioh, plcom_dlbh, rate >> 8);
2044 	bus_space_write_1(iot, ioh, plcom_lcr, cflag2lcr(cflag) | LCR_FEN);
2045 	bus_space_write_1(iot, ioh, plcom_cr, CR_UARTEN);
2046 
2047 #if 0
2048 	/* Ought to do something like this, but we have no sc to
2049 	   dereference. */
2050 	/* XXX device_unit() abuse */
2051 	sc->sc_set_mcr(sc->sc_set_mcr_arg, device_unit(&sc->sc_dev),
2052 	    MCR_DTR | MCR_RTS);
2053 #endif
2054 
2055 	*iohp = ioh;
2056 	return 0;
2057 }
2058 
2059 /*
2060  * Following are all routines needed for PLCOM to act as console
2061  */
2062 struct consdev plcomcons = {
2063 	NULL, NULL, plcomcngetc, plcomcnputc, plcomcnpollc, NULL,
2064 	NULL, NULL, NODEV, CN_NORMAL
2065 };
2066 
2067 
2068 int
2069 plcomcnattach(bus_space_tag_t iot, bus_addr_t iobase, int rate, int frequency,
2070     tcflag_t cflag, int unit)
2071 {
2072 	int res;
2073 
2074 	res = plcominit(iot, iobase, rate, frequency, cflag, &plcomconsioh);
2075 	if (res)
2076 		return res;
2077 
2078 	cn_tab = &plcomcons;
2079 	cn_init_magic(&plcom_cnm_state);
2080 	cn_set_magic("\047\001"); /* default magic is BREAK */
2081 
2082 	plcomconstag = iot;
2083 	plcomconsunit = unit;
2084 	plcomconsrate = rate;
2085 	plcomconscflag = cflag;
2086 
2087 	return 0;
2088 }
2089 
2090 void
2091 plcomcndetach(void)
2092 {
2093 	bus_space_unmap(plcomconstag, plcomconsioh, PLCOM_UART_SIZE);
2094 	plcomconstag = NULL;
2095 
2096 	cn_tab = NULL;
2097 }
2098 
2099 int
2100 plcomcngetc(dev_t dev)
2101 {
2102 	return plcom_common_getc(dev, plcomconstag, plcomconsioh);
2103 }
2104 
2105 /*
2106  * Console kernel output character routine.
2107  */
2108 void
2109 plcomcnputc(dev_t dev, int c)
2110 {
2111 	plcom_common_putc(dev, plcomconstag, plcomconsioh, c);
2112 }
2113 
2114 void
2115 plcomcnpollc(dev_t dev, int on)
2116 {
2117 
2118 }
2119 
2120 #ifdef KGDB
2121 int
2122 plcom_kgdb_attach(bus_space_tag_t iot, bus_addr_t iobase, int rate,
2123    int frequency, tcflag_t cflag, int unit)
2124 {
2125 	int res;
2126 
2127 	if (iot == plcomconstag && iobase == plcomconsunit)
2128 		return EBUSY; /* cannot share with console */
2129 
2130 	res = plcominit(iot, iobase, rate, frequency, cflag, &plcom_kgdb_ioh);
2131 	if (res)
2132 		return res;
2133 
2134 	kgdb_attach(plcom_kgdb_getc, plcom_kgdb_putc, NULL);
2135 	kgdb_dev = 123; /* unneeded, only to satisfy some tests */
2136 
2137 	plcom_kgdb_iot = iot;
2138 	plcom_kgdb_unit = unit;
2139 
2140 	return 0;
2141 }
2142 
2143 /* ARGSUSED */
2144 int
2145 plcom_kgdb_getc(void *arg)
2146 {
2147 	return plcom_common_getc(NODEV, plcom_kgdb_iot, plcom_kgdb_ioh);
2148 }
2149 
2150 /* ARGSUSED */
2151 void
2152 plcom_kgdb_putc(void *arg, int c)
2153 {
2154 	plcom_common_putc(NODEV, plcom_kgdb_iot, plcom_kgdb_ioh, c);
2155 }
2156 #endif /* KGDB */
2157 
2158 /* helper function to identify the plcom ports used by
2159  console or KGDB (and not yet autoconf attached) */
2160 int
2161 plcom_is_console(bus_space_tag_t iot, int unit,
2162     bus_space_handle_t *ioh)
2163 {
2164 	bus_space_handle_t help;
2165 
2166 	if (!plcomconsattached &&
2167 	    iot == plcomconstag && unit == plcomconsunit)
2168 		help = plcomconsioh;
2169 #ifdef KGDB
2170 	else if (!plcom_kgdb_attached &&
2171 	    iot == plcom_kgdb_iot && unit == plcom_kgdb_unit)
2172 		help = plcom_kgdb_ioh;
2173 #endif
2174 	else
2175 		return 0;
2176 
2177 	if (ioh)
2178 		*ioh = help;
2179 	return 1;
2180 }
2181