xref: /netbsd-src/sys/dev/ic/com.c (revision 1ffa7b76c40339c17a0fb2a09fac93f287cfc046)
1 /*	$NetBSD: com.c,v 1.206 2003/04/28 02:46:09 briggs Exp $	*/
2 
3 /*-
4  * Copyright (c) 1998, 1999 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Charles M. Hannum.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *        This product includes software developed by the NetBSD
21  *        Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 /*
40  * Copyright (c) 1991 The Regents of the University of California.
41  * All rights reserved.
42  *
43  * Redistribution and use in source and binary forms, with or without
44  * modification, are permitted provided that the following conditions
45  * are met:
46  * 1. Redistributions of source code must retain the above copyright
47  *    notice, this list of conditions and the following disclaimer.
48  * 2. Redistributions in binary form must reproduce the above copyright
49  *    notice, this list of conditions and the following disclaimer in the
50  *    documentation and/or other materials provided with the distribution.
51  * 3. All advertising materials mentioning features or use of this software
52  *    must display the following acknowledgement:
53  *	This product includes software developed by the University of
54  *	California, Berkeley and its contributors.
55  * 4. Neither the name of the University nor the names of its contributors
56  *    may be used to endorse or promote products derived from this software
57  *    without specific prior written permission.
58  *
59  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
60  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
61  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
62  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
63  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
64  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
65  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
66  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
67  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
68  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
69  * SUCH DAMAGE.
70  *
71  *	@(#)com.c	7.5 (Berkeley) 5/16/91
72  */
73 
74 /*
75  * COM driver, uses National Semiconductor NS16450/NS16550AF UART
76  * Supports automatic hardware flow control on StarTech ST16C650A UART
77  */
78 
79 #include <sys/cdefs.h>
80 __KERNEL_RCSID(0, "$NetBSD: com.c,v 1.206 2003/04/28 02:46:09 briggs Exp $");
81 
82 #include "opt_com.h"
83 #include "opt_ddb.h"
84 #include "opt_kgdb.h"
85 
86 #include "rnd.h"
87 #if NRND > 0 && defined(RND_COM)
88 #include <sys/rnd.h>
89 #endif
90 
91 /*
92  * Override cnmagic(9) macro before including <sys/systm.h>.
93  * We need to know if cn_check_magic triggered debugger, so set a flag.
94  * Callers of cn_check_magic must declare int cn_trapped = 0;
95  * XXX: this is *ugly*!
96  */
97 #define cn_trap()				\
98 	do {					\
99 		console_debugger();		\
100 		cn_trapped = 1;			\
101 	} while (/* CONSTCOND */ 0)
102 
103 #include <sys/param.h>
104 #include <sys/systm.h>
105 #include <sys/ioctl.h>
106 #include <sys/select.h>
107 #include <sys/tty.h>
108 #include <sys/proc.h>
109 #include <sys/user.h>
110 #include <sys/conf.h>
111 #include <sys/file.h>
112 #include <sys/uio.h>
113 #include <sys/kernel.h>
114 #include <sys/syslog.h>
115 #include <sys/device.h>
116 #include <sys/malloc.h>
117 #include <sys/timepps.h>
118 #include <sys/vnode.h>
119 
120 #include <machine/intr.h>
121 #include <machine/bus.h>
122 
123 #include <dev/ic/comreg.h>
124 #include <dev/ic/comvar.h>
125 #include <dev/ic/ns16550reg.h>
126 #include <dev/ic/st16650reg.h>
127 #ifdef COM_HAYESP
128 #include <dev/ic/hayespreg.h>
129 #endif
130 #define	com_lcr	com_cfcr
131 #include <dev/cons.h>
132 
133 #ifdef COM_HAYESP
134 int comprobeHAYESP(bus_space_handle_t hayespioh, struct com_softc *sc);
135 #endif
136 
137 static void com_enable_debugport(struct com_softc *);
138 
139 void	com_config(struct com_softc *);
140 void	com_shutdown(struct com_softc *);
141 int	comspeed(long, long);
142 static	u_char	cflag2lcr(tcflag_t);
143 int	comparam(struct tty *, struct termios *);
144 void	comstart(struct tty *);
145 int	comhwiflow(struct tty *, int);
146 
147 void	com_loadchannelregs(struct com_softc *);
148 void	com_hwiflow(struct com_softc *);
149 void	com_break(struct com_softc *, int);
150 void	com_modem(struct com_softc *, int);
151 void	tiocm_to_com(struct com_softc *, u_long, int);
152 int	com_to_tiocm(struct com_softc *);
153 void	com_iflush(struct com_softc *);
154 
155 int	com_common_getc(dev_t, bus_space_tag_t, bus_space_handle_t);
156 void	com_common_putc(dev_t, bus_space_tag_t, bus_space_handle_t, int);
157 
158 int	cominit(bus_space_tag_t, bus_addr_t, int, int, tcflag_t,
159 	    bus_space_handle_t *);
160 
161 int	comcngetc(dev_t);
162 void	comcnputc(dev_t, int);
163 void	comcnpollc(dev_t, int);
164 
165 #define	integrate	static inline
166 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
167 void 	comsoft(void *);
168 #else
169 #ifndef __NO_SOFT_SERIAL_INTERRUPT
170 void 	comsoft(void);
171 #else
172 void 	comsoft(void *);
173 struct callout comsoft_callout = CALLOUT_INITIALIZER;
174 #endif
175 #endif
176 integrate void com_rxsoft(struct com_softc *, struct tty *);
177 integrate void com_txsoft(struct com_softc *, struct tty *);
178 integrate void com_stsoft(struct com_softc *, struct tty *);
179 integrate void com_schedrx(struct com_softc *);
180 void	comdiag(void *);
181 
182 extern struct cfdriver com_cd;
183 
184 dev_type_open(comopen);
185 dev_type_close(comclose);
186 dev_type_read(comread);
187 dev_type_write(comwrite);
188 dev_type_ioctl(comioctl);
189 dev_type_stop(comstop);
190 dev_type_tty(comtty);
191 dev_type_poll(compoll);
192 
193 const struct cdevsw com_cdevsw = {
194 	comopen, comclose, comread, comwrite, comioctl,
195 	comstop, comtty, compoll, nommap, ttykqfilter, D_TTY
196 };
197 
198 /*
199  * Make this an option variable one can patch.
200  * But be warned:  this must be a power of 2!
201  */
202 u_int com_rbuf_size = COM_RING_SIZE;
203 
204 /* Stop input when 3/4 of the ring is full; restart when only 1/4 is full. */
205 u_int com_rbuf_hiwat = (COM_RING_SIZE * 1) / 4;
206 u_int com_rbuf_lowat = (COM_RING_SIZE * 3) / 4;
207 
208 static bus_addr_t	comconsaddr;
209 static bus_space_tag_t comconstag;
210 static bus_space_handle_t comconsioh;
211 static int	comconsattached;
212 static int comconsrate;
213 static tcflag_t comconscflag;
214 static struct cnm_state com_cnm_state;
215 
216 static int ppscap =
217 	PPS_TSFMT_TSPEC |
218 	PPS_CAPTUREASSERT |
219 	PPS_CAPTURECLEAR |
220 #ifdef  PPS_SYNC
221 	PPS_HARDPPSONASSERT | PPS_HARDPPSONCLEAR |
222 #endif	/* PPS_SYNC */
223 	PPS_OFFSETASSERT | PPS_OFFSETCLEAR;
224 
225 #ifndef __HAVE_GENERIC_SOFT_INTERRUPTS
226 #ifdef __NO_SOFT_SERIAL_INTERRUPT
227 volatile int	com_softintr_scheduled;
228 #endif
229 #endif
230 
231 #ifdef KGDB
232 #include <sys/kgdb.h>
233 
234 static bus_addr_t com_kgdb_addr;
235 static bus_space_tag_t com_kgdb_iot;
236 static bus_space_handle_t com_kgdb_ioh;
237 static int com_kgdb_attached;
238 
239 int	com_kgdb_getc(void *);
240 void	com_kgdb_putc(void *, int);
241 #endif /* KGDB */
242 
243 #define	COMUNIT_MASK	0x7ffff
244 #define	COMDIALOUT_MASK	0x80000
245 
246 #define	COMUNIT(x)	(minor(x) & COMUNIT_MASK)
247 #define	COMDIALOUT(x)	(minor(x) & COMDIALOUT_MASK)
248 
249 #define	COM_ISALIVE(sc)	((sc)->enabled != 0 && \
250 			 ISSET((sc)->sc_dev.dv_flags, DVF_ACTIVE))
251 
252 #define	BR	BUS_SPACE_BARRIER_READ
253 #define	BW	BUS_SPACE_BARRIER_WRITE
254 #define COM_BARRIER(t, h, f) bus_space_barrier((t), (h), 0, COM_NPORTS, (f))
255 
256 #if (defined(MULTIPROCESSOR) || defined(LOCKDEBUG)) && defined(COM_MPLOCK)
257 
258 #define COM_LOCK(sc) simple_lock(&(sc)->sc_lock)
259 #define COM_UNLOCK(sc) simple_unlock(&(sc)->sc_lock)
260 
261 #else
262 
263 #define COM_LOCK(sc)
264 #define COM_UNLOCK(sc)
265 
266 #endif
267 
268 int
269 comspeed(long speed, long frequency)
270 {
271 #define	divrnd(n, q)	(((n)*2/(q)+1)/2)	/* divide and round off */
272 
273 	int x, err;
274 
275 #if 0
276 	if (speed == 0)
277 		return (0);
278 #endif
279 	if (speed <= 0)
280 		return (-1);
281 	x = divrnd(frequency / 16, speed);
282 	if (x <= 0)
283 		return (-1);
284 	err = divrnd(((quad_t)frequency) * 1000 / 16, speed * x) - 1000;
285 	if (err < 0)
286 		err = -err;
287 	if (err > COM_TOLERANCE)
288 		return (-1);
289 	return (x);
290 
291 #undef	divrnd
292 }
293 
294 #ifdef COM_DEBUG
295 int	com_debug = 0;
296 
297 void comstatus(struct com_softc *, char *);
298 void
299 comstatus(struct com_softc *sc, char *str)
300 {
301 	struct tty *tp = sc->sc_tty;
302 
303 	printf("%s: %s %sclocal  %sdcd %sts_carr_on %sdtr %stx_stopped\n",
304 	    sc->sc_dev.dv_xname, str,
305 	    ISSET(tp->t_cflag, CLOCAL) ? "+" : "-",
306 	    ISSET(sc->sc_msr, MSR_DCD) ? "+" : "-",
307 	    ISSET(tp->t_state, TS_CARR_ON) ? "+" : "-",
308 	    ISSET(sc->sc_mcr, MCR_DTR) ? "+" : "-",
309 	    sc->sc_tx_stopped ? "+" : "-");
310 
311 	printf("%s: %s %scrtscts %scts %sts_ttstop  %srts %xrx_flags\n",
312 	    sc->sc_dev.dv_xname, str,
313 	    ISSET(tp->t_cflag, CRTSCTS) ? "+" : "-",
314 	    ISSET(sc->sc_msr, MSR_CTS) ? "+" : "-",
315 	    ISSET(tp->t_state, TS_TTSTOP) ? "+" : "-",
316 	    ISSET(sc->sc_mcr, MCR_RTS) ? "+" : "-",
317 	    sc->sc_rx_flags);
318 }
319 #endif
320 
321 int
322 comprobe1(bus_space_tag_t iot, bus_space_handle_t ioh)
323 {
324 
325 	/* force access to id reg */
326 	bus_space_write_1(iot, ioh, com_lcr, LCR_8BITS);
327 	bus_space_write_1(iot, ioh, com_iir, 0);
328 	if ((bus_space_read_1(iot, ioh, com_lcr) != LCR_8BITS) ||
329 	    (bus_space_read_1(iot, ioh, com_iir) & 0x38))
330 		return (0);
331 
332 	return (1);
333 }
334 
335 #ifdef COM_HAYESP
336 int
337 comprobeHAYESP(bus_space_handle_t hayespioh, struct com_softc *sc)
338 {
339 	char	val, dips;
340 	int	combaselist[] = { 0x3f8, 0x2f8, 0x3e8, 0x2e8 };
341 	bus_space_tag_t iot = sc->sc_iot;
342 
343 	/*
344 	 * Hayes ESP cards have two iobases.  One is for compatibility with
345 	 * 16550 serial chips, and at the same ISA PC base addresses.  The
346 	 * other is for ESP-specific enhanced features, and lies at a
347 	 * different addressing range entirely (0x140, 0x180, 0x280, or 0x300).
348 	 */
349 
350 	/* Test for ESP signature */
351 	if ((bus_space_read_1(iot, hayespioh, 0) & 0xf3) == 0)
352 		return (0);
353 
354 	/*
355 	 * ESP is present at ESP enhanced base address; unknown com port
356 	 */
357 
358 	/* Get the dip-switch configurations */
359 	bus_space_write_1(iot, hayespioh, HAYESP_CMD1, HAYESP_GETDIPS);
360 	dips = bus_space_read_1(iot, hayespioh, HAYESP_STATUS1);
361 
362 	/* Determine which com port this ESP card services: bits 0,1 of  */
363 	/*  dips is the port # (0-3); combaselist[val] is the com_iobase */
364 	if (sc->sc_iobase != combaselist[dips & 0x03])
365 		return (0);
366 
367 	printf(": ESP");
368 
369  	/* Check ESP Self Test bits. */
370 	/* Check for ESP version 2.0: bits 4,5,6 == 010 */
371 	bus_space_write_1(iot, hayespioh, HAYESP_CMD1, HAYESP_GETTEST);
372 	val = bus_space_read_1(iot, hayespioh, HAYESP_STATUS1); /* Clear reg1 */
373 	val = bus_space_read_1(iot, hayespioh, HAYESP_STATUS2);
374 	if ((val & 0x70) < 0x20) {
375 		printf("-old (%o)", val & 0x70);
376 		/* we do not support the necessary features */
377 		return (0);
378 	}
379 
380 	/* Check for ability to emulate 16550: bit 8 == 1 */
381 	if ((dips & 0x80) == 0) {
382 		printf(" slave");
383 		/* XXX Does slave really mean no 16550 support?? */
384 		return (0);
385 	}
386 
387 	/*
388 	 * If we made it this far, we are a full-featured ESP v2.0 (or
389 	 * better), at the correct com port address.
390 	 */
391 
392 	SET(sc->sc_hwflags, COM_HW_HAYESP);
393 	printf(", 1024 byte fifo\n");
394 	return (1);
395 }
396 #endif
397 
398 static void
399 com_enable_debugport(struct com_softc *sc)
400 {
401 	int s;
402 
403 	/* Turn on line break interrupt, set carrier. */
404 	s = splserial();
405 	COM_LOCK(sc);
406 	sc->sc_ier = IER_ERXRDY;
407 	bus_space_write_1(sc->sc_iot, sc->sc_ioh, com_ier, sc->sc_ier);
408 	SET(sc->sc_mcr, MCR_DTR | MCR_RTS);
409 	bus_space_write_1(sc->sc_iot, sc->sc_ioh, com_mcr, sc->sc_mcr);
410 	COM_UNLOCK(sc);
411 	splx(s);
412 }
413 
414 void
415 com_attach_subr(struct com_softc *sc)
416 {
417 	bus_addr_t iobase = sc->sc_iobase;
418 	bus_space_tag_t iot = sc->sc_iot;
419 	bus_space_handle_t ioh = sc->sc_ioh;
420 	struct tty *tp;
421 #ifdef COM16650
422 	u_int8_t lcr;
423 #endif
424 #ifdef COM_HAYESP
425 	int	hayesp_ports[] = { 0x140, 0x180, 0x280, 0x300, 0 };
426 	int	*hayespp;
427 #endif
428 
429 	callout_init(&sc->sc_diag_callout);
430 #if (defined(MULTIPROCESSOR) || defined(LOCKDEBUG)) && defined(COM_MPLOCK)
431 	simple_lock_init(&sc->sc_lock);
432 #endif
433 
434 	/* Disable interrupts before configuring the device. */
435 	sc->sc_ier = 0;
436 	bus_space_write_1(iot, ioh, com_ier, sc->sc_ier);
437 
438 	if (iot == comconstag && iobase == comconsaddr) {
439 		comconsattached = 1;
440 
441 		/* Make sure the console is always "hardwired". */
442 		delay(1000);			/* wait for output to finish */
443 		SET(sc->sc_hwflags, COM_HW_CONSOLE);
444 		SET(sc->sc_swflags, TIOCFLAG_SOFTCAR);
445 	}
446 
447 #ifdef COM_HAYESP
448 	sc->sc_prescaler = 0;			/* set prescaler to x1. */
449 
450 	/* Look for a Hayes ESP board. */
451 	for (hayespp = hayesp_ports; *hayespp != 0; hayespp++) {
452 		bus_space_handle_t hayespioh;
453 
454 #define	HAYESP_NPORTS	8			/* XXX XXX XXX ??? ??? ??? */
455 		if (bus_space_map(iot, *hayespp, HAYESP_NPORTS, 0, &hayespioh))
456 			continue;
457 		if (comprobeHAYESP(hayespioh, sc)) {
458 			sc->sc_hayespioh = hayespioh;
459 			sc->sc_fifolen = 1024;
460 
461 			break;
462 		}
463 		bus_space_unmap(iot, hayespioh, HAYESP_NPORTS);
464 	}
465 	/* No ESP; look for other things. */
466 	if (!ISSET(sc->sc_hwflags, COM_HW_HAYESP)) {
467 #endif
468 	sc->sc_fifolen = 1;
469 	/* look for a NS 16550AF UART with FIFOs */
470 	bus_space_write_1(iot, ioh, com_fifo,
471 	    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_14);
472 	delay(100);
473 	if (ISSET(bus_space_read_1(iot, ioh, com_iir), IIR_FIFO_MASK)
474 	    == IIR_FIFO_MASK)
475 		if (ISSET(bus_space_read_1(iot, ioh, com_fifo), FIFO_TRIGGER_14)
476 		    == FIFO_TRIGGER_14) {
477 			SET(sc->sc_hwflags, COM_HW_FIFO);
478 
479 #ifdef COM16650
480 			/*
481 			 * IIR changes into the EFR if LCR is set to LCR_EERS
482 			 * on 16650s. We also know IIR != 0 at this point.
483 			 * Write 0 into the EFR, and read it. If the result
484 			 * is 0, we have a 16650.
485 			 *
486 			 * Older 16650s were broken; the test to detect them
487 			 * is taken from the Linux driver. Apparently
488 			 * setting DLAB enable gives access to the EFR on
489 			 * these chips.
490 			 */
491 			lcr = bus_space_read_1(iot, ioh, com_lcr);
492 			bus_space_write_1(iot, ioh, com_lcr, LCR_EERS);
493 			bus_space_write_1(iot, ioh, com_efr, 0);
494 			if (bus_space_read_1(iot, ioh, com_efr) == 0) {
495 				bus_space_write_1(iot, ioh, com_lcr,
496 				    lcr | LCR_DLAB);
497 				if (bus_space_read_1(iot, ioh, com_efr) == 0) {
498 					CLR(sc->sc_hwflags, COM_HW_FIFO);
499 					sc->sc_fifolen = 0;
500 				} else {
501 					SET(sc->sc_hwflags, COM_HW_FLOW);
502 					sc->sc_fifolen = 32;
503 				}
504 			} else
505 #endif
506 				sc->sc_fifolen = 16;
507 
508 #ifdef COM16650
509 			bus_space_write_1(iot, ioh, com_lcr, lcr);
510 			if (sc->sc_fifolen == 0)
511 				aprint_normal(": st16650, broken fifo\n");
512 			else if (sc->sc_fifolen == 32)
513 				aprint_normal(": st16650a, working fifo\n");
514 			else
515 #endif
516 				aprint_normal(": ns16550a, working fifo\n");
517 		} else
518 			aprint_normal(": ns16550, broken fifo\n");
519 	else
520 		aprint_normal(": ns8250 or ns16450, no fifo\n");
521 	bus_space_write_1(iot, ioh, com_fifo, 0);
522 	if (ISSET(sc->sc_hwflags, COM_HW_TXFIFO_DISABLE)) {
523 		sc->sc_fifolen = 1;
524 		aprint_normal("%s: txfifo disabled\n", sc->sc_dev.dv_xname);
525 	}
526 #ifdef COM_HAYESP
527 	}
528 #endif
529 
530 	tp = ttymalloc();
531 	tp->t_oproc = comstart;
532 	tp->t_param = comparam;
533 	tp->t_hwiflow = comhwiflow;
534 
535 	sc->sc_tty = tp;
536 	sc->sc_rbuf = malloc(com_rbuf_size << 1, M_DEVBUF, M_NOWAIT);
537 	sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
538 	sc->sc_rbavail = com_rbuf_size;
539 	if (sc->sc_rbuf == NULL) {
540 		aprint_error("%s: unable to allocate ring buffer\n",
541 		    sc->sc_dev.dv_xname);
542 		return;
543 	}
544 	sc->sc_ebuf = sc->sc_rbuf + (com_rbuf_size << 1);
545 
546 	tty_attach(tp);
547 
548 	if (!ISSET(sc->sc_hwflags, COM_HW_NOIEN))
549 		SET(sc->sc_mcr, MCR_IENABLE);
550 
551 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
552 		int maj;
553 
554 		/* locate the major number */
555 		maj = cdevsw_lookup_major(&com_cdevsw);
556 
557 		cn_tab->cn_dev = makedev(maj, sc->sc_dev.dv_unit);
558 
559 		aprint_normal("%s: console\n", sc->sc_dev.dv_xname);
560 	}
561 
562 #ifdef KGDB
563 	/*
564 	 * Allow kgdb to "take over" this port.  If this is
565 	 * not the console and is the kgdb device, it has
566 	 * exclusive use.  If it's the console _and_ the
567 	 * kgdb device, it doesn't.
568 	 */
569 	if (iot == com_kgdb_iot && iobase == com_kgdb_addr) {
570 		if (!ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
571 			com_kgdb_attached = 1;
572 
573 			SET(sc->sc_hwflags, COM_HW_KGDB);
574 		}
575 		aprint_normal("%s: kgdb\n", sc->sc_dev.dv_xname);
576 	}
577 #endif
578 
579 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
580 	sc->sc_si = softintr_establish(IPL_SOFTSERIAL, comsoft, sc);
581 #endif
582 
583 #if NRND > 0 && defined(RND_COM)
584 	rnd_attach_source(&sc->rnd_source, sc->sc_dev.dv_xname,
585 			  RND_TYPE_TTY, 0);
586 #endif
587 
588 	/* if there are no enable/disable functions, assume the device
589 	   is always enabled */
590 	if (!sc->enable)
591 		sc->enabled = 1;
592 
593 	com_config(sc);
594 
595 	SET(sc->sc_hwflags, COM_HW_DEV_OK);
596 }
597 
598 void
599 com_config(struct com_softc *sc)
600 {
601 	bus_space_tag_t iot = sc->sc_iot;
602 	bus_space_handle_t ioh = sc->sc_ioh;
603 
604 	/* Disable interrupts before configuring the device. */
605 	sc->sc_ier = 0;
606 	bus_space_write_1(iot, ioh, com_ier, sc->sc_ier);
607 
608 #ifdef COM_HAYESP
609 	/* Look for a Hayes ESP board. */
610 	if (ISSET(sc->sc_hwflags, COM_HW_HAYESP)) {
611 		sc->sc_fifolen = 1024;
612 
613 		/* Set 16550 compatibility mode */
614 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD1,
615 				  HAYESP_SETMODE);
616 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
617 				  HAYESP_MODE_FIFO|HAYESP_MODE_RTS|
618 				  HAYESP_MODE_SCALE);
619 
620 		/* Set RTS/CTS flow control */
621 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD1,
622 				  HAYESP_SETFLOWTYPE);
623 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
624 				  HAYESP_FLOW_RTS);
625 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
626 				  HAYESP_FLOW_CTS);
627 
628 		/* Set flow control levels */
629 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD1,
630 				  HAYESP_SETRXFLOW);
631 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
632 				  HAYESP_HIBYTE(HAYESP_RXHIWMARK));
633 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
634 				  HAYESP_LOBYTE(HAYESP_RXHIWMARK));
635 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
636 				  HAYESP_HIBYTE(HAYESP_RXLOWMARK));
637 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
638 				  HAYESP_LOBYTE(HAYESP_RXLOWMARK));
639 	}
640 #endif
641 
642 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE|COM_HW_KGDB))
643 		com_enable_debugport(sc);
644 }
645 
646 int
647 com_detach(struct device *self, int flags)
648 {
649 	struct com_softc *sc = (struct com_softc *)self;
650 	int maj, mn;
651 
652 	/* locate the major number */
653 	maj = cdevsw_lookup_major(&com_cdevsw);
654 
655 	/* Nuke the vnodes for any open instances. */
656 	mn = self->dv_unit;
657 	vdevgone(maj, mn, mn, VCHR);
658 
659 	mn |= COMDIALOUT_MASK;
660 	vdevgone(maj, mn, mn, VCHR);
661 
662 	if (sc->sc_rbuf == NULL) {
663 		/*
664 		 * Ring buffer allocation failed in the com_attach_subr,
665 		 * only the tty is allocated, and nothing else.
666 		 */
667 		ttyfree(sc->sc_tty);
668 		return 0;
669 	}
670 
671 	/* Free the receive buffer. */
672 	free(sc->sc_rbuf, M_DEVBUF);
673 
674 	/* Detach and free the tty. */
675 	tty_detach(sc->sc_tty);
676 	ttyfree(sc->sc_tty);
677 
678 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
679 	/* Unhook the soft interrupt handler. */
680 	softintr_disestablish(sc->sc_si);
681 #endif
682 
683 #if NRND > 0 && defined(RND_COM)
684 	/* Unhook the entropy source. */
685 	rnd_detach_source(&sc->rnd_source);
686 #endif
687 
688 	return (0);
689 }
690 
691 int
692 com_activate(struct device *self, enum devact act)
693 {
694 	struct com_softc *sc = (struct com_softc *)self;
695 	int s, rv = 0;
696 
697 	s = splserial();
698 	COM_LOCK(sc);
699 	switch (act) {
700 	case DVACT_ACTIVATE:
701 		rv = EOPNOTSUPP;
702 		break;
703 
704 	case DVACT_DEACTIVATE:
705 		if (sc->sc_hwflags & (COM_HW_CONSOLE|COM_HW_KGDB)) {
706 			rv = EBUSY;
707 			break;
708 		}
709 
710 		if (sc->disable != NULL && sc->enabled != 0) {
711 			(*sc->disable)(sc);
712 			sc->enabled = 0;
713 		}
714 		break;
715 	}
716 
717 	COM_UNLOCK(sc);
718 	splx(s);
719 	return (rv);
720 }
721 
722 void
723 com_shutdown(struct com_softc *sc)
724 {
725 	struct tty *tp = sc->sc_tty;
726 	int s;
727 
728 	s = splserial();
729 	COM_LOCK(sc);
730 
731 	/* If we were asserting flow control, then deassert it. */
732 	SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
733 	com_hwiflow(sc);
734 
735 	/* Clear any break condition set with TIOCSBRK. */
736 	com_break(sc, 0);
737 
738 	/* Turn off PPS capture on last close. */
739 	sc->sc_ppsmask = 0;
740 	sc->ppsparam.mode = 0;
741 
742 	/*
743 	 * Hang up if necessary.  Wait a bit, so the other side has time to
744 	 * notice even if we immediately open the port again.
745 	 * Avoid tsleeping above splhigh().
746 	 */
747 	if (ISSET(tp->t_cflag, HUPCL)) {
748 		com_modem(sc, 0);
749 		COM_UNLOCK(sc);
750 		splx(s);
751 		/* XXX tsleep will only timeout */
752 		(void) tsleep(sc, TTIPRI, ttclos, hz);
753 		s = splserial();
754 		COM_LOCK(sc);
755 	}
756 
757 	/* Turn off interrupts. */
758 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE))
759 		sc->sc_ier = IER_ERXRDY; /* interrupt on break */
760 	else
761 		sc->sc_ier = 0;
762 	bus_space_write_1(sc->sc_iot, sc->sc_ioh, com_ier, sc->sc_ier);
763 
764 	if (sc->disable) {
765 #ifdef DIAGNOSTIC
766 		if (!sc->enabled)
767 			panic("com_shutdown: not enabled?");
768 #endif
769 		(*sc->disable)(sc);
770 		sc->enabled = 0;
771 	}
772 	COM_UNLOCK(sc);
773 	splx(s);
774 }
775 
776 int
777 comopen(dev_t dev, int flag, int mode, struct proc *p)
778 {
779 	struct com_softc *sc;
780 	struct tty *tp;
781 	int s, s2;
782 	int error;
783 
784 	sc = device_lookup(&com_cd, COMUNIT(dev));
785 	if (sc == NULL || !ISSET(sc->sc_hwflags, COM_HW_DEV_OK) ||
786 		sc->sc_rbuf == NULL)
787 		return (ENXIO);
788 
789 	if (ISSET(sc->sc_dev.dv_flags, DVF_ACTIVE) == 0)
790 		return (ENXIO);
791 
792 #ifdef KGDB
793 	/*
794 	 * If this is the kgdb port, no other use is permitted.
795 	 */
796 	if (ISSET(sc->sc_hwflags, COM_HW_KGDB))
797 		return (EBUSY);
798 #endif
799 
800 	tp = sc->sc_tty;
801 
802 	if (ISSET(tp->t_state, TS_ISOPEN) &&
803 	    ISSET(tp->t_state, TS_XCLUDE) &&
804 		p->p_ucred->cr_uid != 0)
805 		return (EBUSY);
806 
807 	s = spltty();
808 
809 	/*
810 	 * Do the following iff this is a first open.
811 	 */
812 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
813 		struct termios t;
814 
815 		tp->t_dev = dev;
816 
817 		s2 = splserial();
818 		COM_LOCK(sc);
819 
820 		if (sc->enable) {
821 			if ((*sc->enable)(sc)) {
822 				COM_UNLOCK(sc);
823 				splx(s2);
824 				splx(s);
825 				printf("%s: device enable failed\n",
826 				       sc->sc_dev.dv_xname);
827 				return (EIO);
828 			}
829 			sc->enabled = 1;
830 			com_config(sc);
831 		}
832 
833 		/* Turn on interrupts. */
834 		sc->sc_ier = IER_ERXRDY | IER_ERLS | IER_EMSC;
835 		bus_space_write_1(sc->sc_iot, sc->sc_ioh, com_ier, sc->sc_ier);
836 
837 		/* Fetch the current modem control status, needed later. */
838 		sc->sc_msr = bus_space_read_1(sc->sc_iot, sc->sc_ioh, com_msr);
839 
840 		/* Clear PPS capture state on first open. */
841 		sc->sc_ppsmask = 0;
842 		sc->ppsparam.mode = 0;
843 
844 		COM_UNLOCK(sc);
845 		splx(s2);
846 
847 		/*
848 		 * Initialize the termios status to the defaults.  Add in the
849 		 * sticky bits from TIOCSFLAGS.
850 		 */
851 		t.c_ispeed = 0;
852 		if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
853 			t.c_ospeed = comconsrate;
854 			t.c_cflag = comconscflag;
855 		} else {
856 			t.c_ospeed = TTYDEF_SPEED;
857 			t.c_cflag = TTYDEF_CFLAG;
858 		}
859 		if (ISSET(sc->sc_swflags, TIOCFLAG_CLOCAL))
860 			SET(t.c_cflag, CLOCAL);
861 		if (ISSET(sc->sc_swflags, TIOCFLAG_CRTSCTS))
862 			SET(t.c_cflag, CRTSCTS);
863 		if (ISSET(sc->sc_swflags, TIOCFLAG_MDMBUF))
864 			SET(t.c_cflag, MDMBUF);
865 		/* Make sure comparam() will do something. */
866 		tp->t_ospeed = 0;
867 		(void) comparam(tp, &t);
868 		tp->t_iflag = TTYDEF_IFLAG;
869 		tp->t_oflag = TTYDEF_OFLAG;
870 		tp->t_lflag = TTYDEF_LFLAG;
871 		ttychars(tp);
872 		ttsetwater(tp);
873 
874 		s2 = splserial();
875 		COM_LOCK(sc);
876 
877 		/*
878 		 * Turn on DTR.  We must always do this, even if carrier is not
879 		 * present, because otherwise we'd have to use TIOCSDTR
880 		 * immediately after setting CLOCAL, which applications do not
881 		 * expect.  We always assert DTR while the device is open
882 		 * unless explicitly requested to deassert it.
883 		 */
884 		com_modem(sc, 1);
885 
886 		/* Clear the input ring, and unblock. */
887 		sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
888 		sc->sc_rbavail = com_rbuf_size;
889 		com_iflush(sc);
890 		CLR(sc->sc_rx_flags, RX_ANY_BLOCK);
891 		com_hwiflow(sc);
892 
893 #ifdef COM_DEBUG
894 		if (com_debug)
895 			comstatus(sc, "comopen  ");
896 #endif
897 
898 		COM_UNLOCK(sc);
899 		splx(s2);
900 	}
901 
902 	splx(s);
903 
904 	error = ttyopen(tp, COMDIALOUT(dev), ISSET(flag, O_NONBLOCK));
905 	if (error)
906 		goto bad;
907 
908 	error = (*tp->t_linesw->l_open)(dev, tp);
909 	if (error)
910 		goto bad;
911 
912 	return (0);
913 
914 bad:
915 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
916 		/*
917 		 * We failed to open the device, and nobody else had it opened.
918 		 * Clean up the state as appropriate.
919 		 */
920 		com_shutdown(sc);
921 	}
922 
923 	return (error);
924 }
925 
926 int
927 comclose(dev_t dev, int flag, int mode, struct proc *p)
928 {
929 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(dev));
930 	struct tty *tp = sc->sc_tty;
931 
932 	/* XXX This is for cons.c. */
933 	if (!ISSET(tp->t_state, TS_ISOPEN))
934 		return (0);
935 
936 	(*tp->t_linesw->l_close)(tp, flag);
937 	ttyclose(tp);
938 
939 	if (COM_ISALIVE(sc) == 0)
940 		return (0);
941 
942 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
943 		/*
944 		 * Although we got a last close, the device may still be in
945 		 * use; e.g. if this was the dialout node, and there are still
946 		 * processes waiting for carrier on the non-dialout node.
947 		 */
948 		com_shutdown(sc);
949 	}
950 
951 	return (0);
952 }
953 
954 int
955 comread(dev_t dev, struct uio *uio, int flag)
956 {
957 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(dev));
958 	struct tty *tp = sc->sc_tty;
959 
960 	if (COM_ISALIVE(sc) == 0)
961 		return (EIO);
962 
963 	return ((*tp->t_linesw->l_read)(tp, uio, flag));
964 }
965 
966 int
967 comwrite(dev_t dev, struct uio *uio, int flag)
968 {
969 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(dev));
970 	struct tty *tp = sc->sc_tty;
971 
972 	if (COM_ISALIVE(sc) == 0)
973 		return (EIO);
974 
975 	return ((*tp->t_linesw->l_write)(tp, uio, flag));
976 }
977 
978 int
979 compoll(dev_t dev, int events, struct proc *p)
980 {
981 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(dev));
982 	struct tty *tp = sc->sc_tty;
983 
984 	if (COM_ISALIVE(sc) == 0)
985 		return (EIO);
986 
987 	return ((*tp->t_linesw->l_poll)(tp, events, p));
988 }
989 
990 struct tty *
991 comtty(dev_t dev)
992 {
993 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(dev));
994 	struct tty *tp = sc->sc_tty;
995 
996 	return (tp);
997 }
998 
999 int
1000 comioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct proc *p)
1001 {
1002 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(dev));
1003 	struct tty *tp = sc->sc_tty;
1004 	int error;
1005 	int s;
1006 
1007 	if (COM_ISALIVE(sc) == 0)
1008 		return (EIO);
1009 
1010 	error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, p);
1011 	if (error != EPASSTHROUGH)
1012 		return (error);
1013 
1014 	error = ttioctl(tp, cmd, data, flag, p);
1015 	if (error != EPASSTHROUGH)
1016 		return (error);
1017 
1018 	error = 0;
1019 
1020 	s = splserial();
1021 	COM_LOCK(sc);
1022 
1023 	switch (cmd) {
1024 	case TIOCSBRK:
1025 		com_break(sc, 1);
1026 		break;
1027 
1028 	case TIOCCBRK:
1029 		com_break(sc, 0);
1030 		break;
1031 
1032 	case TIOCSDTR:
1033 		com_modem(sc, 1);
1034 		break;
1035 
1036 	case TIOCCDTR:
1037 		com_modem(sc, 0);
1038 		break;
1039 
1040 	case TIOCGFLAGS:
1041 		*(int *)data = sc->sc_swflags;
1042 		break;
1043 
1044 	case TIOCSFLAGS:
1045 		error = suser(p->p_ucred, &p->p_acflag);
1046 		if (error)
1047 			break;
1048 		sc->sc_swflags = *(int *)data;
1049 		break;
1050 
1051 	case TIOCMSET:
1052 	case TIOCMBIS:
1053 	case TIOCMBIC:
1054 		tiocm_to_com(sc, cmd, *(int *)data);
1055 		break;
1056 
1057 	case TIOCMGET:
1058 		*(int *)data = com_to_tiocm(sc);
1059 		break;
1060 
1061 	case PPS_IOC_CREATE:
1062 		break;
1063 
1064 	case PPS_IOC_DESTROY:
1065 		break;
1066 
1067 	case PPS_IOC_GETPARAMS: {
1068 		pps_params_t *pp;
1069 		pp = (pps_params_t *)data;
1070 		*pp = sc->ppsparam;
1071 		break;
1072 	}
1073 
1074 	case PPS_IOC_SETPARAMS: {
1075 	  	pps_params_t *pp;
1076 		int mode;
1077 		pp = (pps_params_t *)data;
1078 		if (pp->mode & ~ppscap) {
1079 			error = EINVAL;
1080 			break;
1081 		}
1082 		sc->ppsparam = *pp;
1083 	 	/*
1084 		 * Compute msr masks from user-specified timestamp state.
1085 		 */
1086 		mode = sc->ppsparam.mode;
1087 #ifdef	PPS_SYNC
1088 		if (mode & PPS_HARDPPSONASSERT) {
1089 			mode |= PPS_CAPTUREASSERT;
1090 			/* XXX revoke any previous HARDPPS source */
1091 		}
1092 		if (mode & PPS_HARDPPSONCLEAR) {
1093 			mode |= PPS_CAPTURECLEAR;
1094 			/* XXX revoke any previous HARDPPS source */
1095 		}
1096 #endif	/* PPS_SYNC */
1097 		switch (mode & PPS_CAPTUREBOTH) {
1098 		case 0:
1099 			sc->sc_ppsmask = 0;
1100 			break;
1101 
1102 		case PPS_CAPTUREASSERT:
1103 			sc->sc_ppsmask = MSR_DCD;
1104 			sc->sc_ppsassert = MSR_DCD;
1105 			sc->sc_ppsclear = -1;
1106 			break;
1107 
1108 		case PPS_CAPTURECLEAR:
1109 			sc->sc_ppsmask = MSR_DCD;
1110 			sc->sc_ppsassert = -1;
1111 			sc->sc_ppsclear = 0;
1112 			break;
1113 
1114 		case PPS_CAPTUREBOTH:
1115 			sc->sc_ppsmask = MSR_DCD;
1116 			sc->sc_ppsassert = MSR_DCD;
1117 			sc->sc_ppsclear = 0;
1118 			break;
1119 
1120 		default:
1121 			error = EINVAL;
1122 			break;
1123 		}
1124 		break;
1125 	}
1126 
1127 	case PPS_IOC_GETCAP:
1128 		*(int*)data = ppscap;
1129 		break;
1130 
1131 	case PPS_IOC_FETCH: {
1132 		pps_info_t *pi;
1133 		pi = (pps_info_t *)data;
1134 		*pi = sc->ppsinfo;
1135 		break;
1136 	}
1137 
1138 	case TIOCDCDTIMESTAMP:	/* XXX old, overloaded  API used by xntpd v3 */
1139 		/*
1140 		 * Some GPS clocks models use the falling rather than
1141 		 * rising edge as the on-the-second signal.
1142 		 * The old API has no way to specify PPS polarity.
1143 		 */
1144 		sc->sc_ppsmask = MSR_DCD;
1145 #ifndef PPS_TRAILING_EDGE
1146 		sc->sc_ppsassert = MSR_DCD;
1147 		sc->sc_ppsclear = -1;
1148 		TIMESPEC_TO_TIMEVAL((struct timeval *)data,
1149 		    &sc->ppsinfo.assert_timestamp);
1150 #else
1151 		sc->sc_ppsassert = -1
1152 		sc->sc_ppsclear = 0;
1153 		TIMESPEC_TO_TIMEVAL((struct timeval *)data,
1154 		    &sc->ppsinfo.clear_timestamp);
1155 #endif
1156 		break;
1157 
1158 	default:
1159 		error = EPASSTHROUGH;
1160 		break;
1161 	}
1162 
1163 	COM_UNLOCK(sc);
1164 	splx(s);
1165 
1166 #ifdef COM_DEBUG
1167 	if (com_debug)
1168 		comstatus(sc, "comioctl ");
1169 #endif
1170 
1171 	return (error);
1172 }
1173 
1174 integrate void
1175 com_schedrx(struct com_softc *sc)
1176 {
1177 
1178 	sc->sc_rx_ready = 1;
1179 
1180 	/* Wake up the poller. */
1181 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
1182 	softintr_schedule(sc->sc_si);
1183 #else
1184 #ifndef __NO_SOFT_SERIAL_INTERRUPT
1185 	setsoftserial();
1186 #else
1187 	if (!com_softintr_scheduled) {
1188 		com_softintr_scheduled = 1;
1189 		callout_reset(&comsoft_callout, 1, comsoft, NULL);
1190 	}
1191 #endif
1192 #endif
1193 }
1194 
1195 void
1196 com_break(struct com_softc *sc, int onoff)
1197 {
1198 
1199 	if (onoff)
1200 		SET(sc->sc_lcr, LCR_SBREAK);
1201 	else
1202 		CLR(sc->sc_lcr, LCR_SBREAK);
1203 
1204 	if (!sc->sc_heldchange) {
1205 		if (sc->sc_tx_busy) {
1206 			sc->sc_heldtbc = sc->sc_tbc;
1207 			sc->sc_tbc = 0;
1208 			sc->sc_heldchange = 1;
1209 		} else
1210 			com_loadchannelregs(sc);
1211 	}
1212 }
1213 
1214 void
1215 com_modem(struct com_softc *sc, int onoff)
1216 {
1217 
1218 	if (sc->sc_mcr_dtr == 0)
1219 		return;
1220 
1221 	if (onoff)
1222 		SET(sc->sc_mcr, sc->sc_mcr_dtr);
1223 	else
1224 		CLR(sc->sc_mcr, sc->sc_mcr_dtr);
1225 
1226 	if (!sc->sc_heldchange) {
1227 		if (sc->sc_tx_busy) {
1228 			sc->sc_heldtbc = sc->sc_tbc;
1229 			sc->sc_tbc = 0;
1230 			sc->sc_heldchange = 1;
1231 		} else
1232 			com_loadchannelregs(sc);
1233 	}
1234 }
1235 
1236 void
1237 tiocm_to_com(struct com_softc *sc, u_long how, int ttybits)
1238 {
1239 	u_char combits;
1240 
1241 	combits = 0;
1242 	if (ISSET(ttybits, TIOCM_DTR))
1243 		SET(combits, MCR_DTR);
1244 	if (ISSET(ttybits, TIOCM_RTS))
1245 		SET(combits, MCR_RTS);
1246 
1247 	switch (how) {
1248 	case TIOCMBIC:
1249 		CLR(sc->sc_mcr, combits);
1250 		break;
1251 
1252 	case TIOCMBIS:
1253 		SET(sc->sc_mcr, combits);
1254 		break;
1255 
1256 	case TIOCMSET:
1257 		CLR(sc->sc_mcr, MCR_DTR | MCR_RTS);
1258 		SET(sc->sc_mcr, combits);
1259 		break;
1260 	}
1261 
1262 	if (!sc->sc_heldchange) {
1263 		if (sc->sc_tx_busy) {
1264 			sc->sc_heldtbc = sc->sc_tbc;
1265 			sc->sc_tbc = 0;
1266 			sc->sc_heldchange = 1;
1267 		} else
1268 			com_loadchannelregs(sc);
1269 	}
1270 }
1271 
1272 int
1273 com_to_tiocm(struct com_softc *sc)
1274 {
1275 	u_char combits;
1276 	int ttybits = 0;
1277 
1278 	combits = sc->sc_mcr;
1279 	if (ISSET(combits, MCR_DTR))
1280 		SET(ttybits, TIOCM_DTR);
1281 	if (ISSET(combits, MCR_RTS))
1282 		SET(ttybits, TIOCM_RTS);
1283 
1284 	combits = sc->sc_msr;
1285 	if (ISSET(combits, MSR_DCD))
1286 		SET(ttybits, TIOCM_CD);
1287 	if (ISSET(combits, MSR_CTS))
1288 		SET(ttybits, TIOCM_CTS);
1289 	if (ISSET(combits, MSR_DSR))
1290 		SET(ttybits, TIOCM_DSR);
1291 	if (ISSET(combits, MSR_RI | MSR_TERI))
1292 		SET(ttybits, TIOCM_RI);
1293 
1294 	if (sc->sc_ier != 0)
1295 		SET(ttybits, TIOCM_LE);
1296 
1297 	return (ttybits);
1298 }
1299 
1300 static u_char
1301 cflag2lcr(tcflag_t cflag)
1302 {
1303 	u_char lcr = 0;
1304 
1305 	switch (ISSET(cflag, CSIZE)) {
1306 	case CS5:
1307 		SET(lcr, LCR_5BITS);
1308 		break;
1309 	case CS6:
1310 		SET(lcr, LCR_6BITS);
1311 		break;
1312 	case CS7:
1313 		SET(lcr, LCR_7BITS);
1314 		break;
1315 	case CS8:
1316 		SET(lcr, LCR_8BITS);
1317 		break;
1318 	}
1319 	if (ISSET(cflag, PARENB)) {
1320 		SET(lcr, LCR_PENAB);
1321 		if (!ISSET(cflag, PARODD))
1322 			SET(lcr, LCR_PEVEN);
1323 	}
1324 	if (ISSET(cflag, CSTOPB))
1325 		SET(lcr, LCR_STOPB);
1326 
1327 	return (lcr);
1328 }
1329 
1330 int
1331 comparam(struct tty *tp, struct termios *t)
1332 {
1333 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(tp->t_dev));
1334 	int ospeed;
1335 	u_char lcr;
1336 	int s;
1337 
1338 	if (COM_ISALIVE(sc) == 0)
1339 		return (EIO);
1340 
1341 #ifdef COM_HAYESP
1342 	if (ISSET(sc->sc_hwflags, COM_HW_HAYESP)) {
1343 		int prescaler, speed;
1344 
1345 		/*
1346 		 * Calculate UART clock prescaler.  It should be in
1347 		 * range of 0 .. 3.
1348 		 */
1349 		for (prescaler = 0, speed = t->c_ospeed; prescaler < 4;
1350 		    prescaler++, speed /= 2)
1351 			if ((ospeed = comspeed(speed, sc->sc_frequency)) > 0)
1352 				break;
1353 
1354 		if (prescaler == 4)
1355 			return (EINVAL);
1356 		sc->sc_prescaler = prescaler;
1357 	} else
1358 #endif
1359 	ospeed = comspeed(t->c_ospeed, sc->sc_frequency);
1360 
1361 	/* Check requested parameters. */
1362 	if (ospeed < 0)
1363 		return (EINVAL);
1364 	if (t->c_ispeed && t->c_ispeed != t->c_ospeed)
1365 		return (EINVAL);
1366 
1367 	/*
1368 	 * For the console, always force CLOCAL and !HUPCL, so that the port
1369 	 * is always active.
1370 	 */
1371 	if (ISSET(sc->sc_swflags, TIOCFLAG_SOFTCAR) ||
1372 	    ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
1373 		SET(t->c_cflag, CLOCAL);
1374 		CLR(t->c_cflag, HUPCL);
1375 	}
1376 
1377 	/*
1378 	 * If there were no changes, don't do anything.  This avoids dropping
1379 	 * input and improves performance when all we did was frob things like
1380 	 * VMIN and VTIME.
1381 	 */
1382 	if (tp->t_ospeed == t->c_ospeed &&
1383 	    tp->t_cflag == t->c_cflag)
1384 		return (0);
1385 
1386 	lcr = ISSET(sc->sc_lcr, LCR_SBREAK) | cflag2lcr(t->c_cflag);
1387 
1388 	s = splserial();
1389 	COM_LOCK(sc);
1390 
1391 	sc->sc_lcr = lcr;
1392 
1393 	/*
1394 	 * If we're not in a mode that assumes a connection is present, then
1395 	 * ignore carrier changes.
1396 	 */
1397 	if (ISSET(t->c_cflag, CLOCAL | MDMBUF))
1398 		sc->sc_msr_dcd = 0;
1399 	else
1400 		sc->sc_msr_dcd = MSR_DCD;
1401 	/*
1402 	 * Set the flow control pins depending on the current flow control
1403 	 * mode.
1404 	 */
1405 	if (ISSET(t->c_cflag, CRTSCTS)) {
1406 		sc->sc_mcr_dtr = MCR_DTR;
1407 		sc->sc_mcr_rts = MCR_RTS;
1408 		sc->sc_msr_cts = MSR_CTS;
1409 		sc->sc_efr = EFR_AUTORTS | EFR_AUTOCTS;
1410 	} else if (ISSET(t->c_cflag, MDMBUF)) {
1411 		/*
1412 		 * For DTR/DCD flow control, make sure we don't toggle DTR for
1413 		 * carrier detection.
1414 		 */
1415 		sc->sc_mcr_dtr = 0;
1416 		sc->sc_mcr_rts = MCR_DTR;
1417 		sc->sc_msr_cts = MSR_DCD;
1418 		sc->sc_efr = 0;
1419 	} else {
1420 		/*
1421 		 * If no flow control, then always set RTS.  This will make
1422 		 * the other side happy if it mistakenly thinks we're doing
1423 		 * RTS/CTS flow control.
1424 		 */
1425 		sc->sc_mcr_dtr = MCR_DTR | MCR_RTS;
1426 		sc->sc_mcr_rts = 0;
1427 		sc->sc_msr_cts = 0;
1428 		sc->sc_efr = 0;
1429 		if (ISSET(sc->sc_mcr, MCR_DTR))
1430 			SET(sc->sc_mcr, MCR_RTS);
1431 		else
1432 			CLR(sc->sc_mcr, MCR_RTS);
1433 	}
1434 	sc->sc_msr_mask = sc->sc_msr_cts | sc->sc_msr_dcd;
1435 
1436 #if 0
1437 	if (ospeed == 0)
1438 		CLR(sc->sc_mcr, sc->sc_mcr_dtr);
1439 	else
1440 		SET(sc->sc_mcr, sc->sc_mcr_dtr);
1441 #endif
1442 
1443 	sc->sc_dlbl = ospeed;
1444 	sc->sc_dlbh = ospeed >> 8;
1445 
1446 	/*
1447 	 * Set the FIFO threshold based on the receive speed.
1448 	 *
1449 	 *  * If it's a low speed, it's probably a mouse or some other
1450 	 *    interactive device, so set the threshold low.
1451 	 *  * If it's a high speed, trim the trigger level down to prevent
1452 	 *    overflows.
1453 	 *  * Otherwise set it a bit higher.
1454 	 */
1455 	if (ISSET(sc->sc_hwflags, COM_HW_HAYESP))
1456 		sc->sc_fifo = FIFO_DMA_MODE | FIFO_ENABLE | FIFO_TRIGGER_8;
1457 	else if (ISSET(sc->sc_hwflags, COM_HW_FIFO))
1458 		sc->sc_fifo = FIFO_ENABLE |
1459 		    (t->c_ospeed <= 1200 ? FIFO_TRIGGER_1 :
1460 		     t->c_ospeed <= 38400 ? FIFO_TRIGGER_8 : FIFO_TRIGGER_4);
1461 	else
1462 		sc->sc_fifo = 0;
1463 
1464 	/* And copy to tty. */
1465 	tp->t_ispeed = 0;
1466 	tp->t_ospeed = t->c_ospeed;
1467 	tp->t_cflag = t->c_cflag;
1468 
1469 	if (!sc->sc_heldchange) {
1470 		if (sc->sc_tx_busy) {
1471 			sc->sc_heldtbc = sc->sc_tbc;
1472 			sc->sc_tbc = 0;
1473 			sc->sc_heldchange = 1;
1474 		} else
1475 			com_loadchannelregs(sc);
1476 	}
1477 
1478 	if (!ISSET(t->c_cflag, CHWFLOW)) {
1479 		/* Disable the high water mark. */
1480 		sc->sc_r_hiwat = 0;
1481 		sc->sc_r_lowat = 0;
1482 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
1483 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1484 			com_schedrx(sc);
1485 		}
1486 		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED)) {
1487 			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED);
1488 			com_hwiflow(sc);
1489 		}
1490 	} else {
1491 		sc->sc_r_hiwat = com_rbuf_hiwat;
1492 		sc->sc_r_lowat = com_rbuf_lowat;
1493 	}
1494 
1495 	COM_UNLOCK(sc);
1496 	splx(s);
1497 
1498 	/*
1499 	 * Update the tty layer's idea of the carrier bit, in case we changed
1500 	 * CLOCAL or MDMBUF.  We don't hang up here; we only do that by
1501 	 * explicit request.
1502 	 */
1503 	(void) (*tp->t_linesw->l_modem)(tp, ISSET(sc->sc_msr, MSR_DCD));
1504 
1505 #ifdef COM_DEBUG
1506 	if (com_debug)
1507 		comstatus(sc, "comparam ");
1508 #endif
1509 
1510 	if (!ISSET(t->c_cflag, CHWFLOW)) {
1511 		if (sc->sc_tx_stopped) {
1512 			sc->sc_tx_stopped = 0;
1513 			comstart(tp);
1514 		}
1515 	}
1516 
1517 	return (0);
1518 }
1519 
1520 void
1521 com_iflush(struct com_softc *sc)
1522 {
1523 	bus_space_tag_t iot = sc->sc_iot;
1524 	bus_space_handle_t ioh = sc->sc_ioh;
1525 #ifdef DIAGNOSTIC
1526 	int reg;
1527 #endif
1528 	int timo;
1529 
1530 #ifdef DIAGNOSTIC
1531 	reg = 0xffff;
1532 #endif
1533 	timo = 50000;
1534 	/* flush any pending I/O */
1535 	while (ISSET(bus_space_read_1(iot, ioh, com_lsr), LSR_RXRDY)
1536 	    && --timo)
1537 #ifdef DIAGNOSTIC
1538 		reg =
1539 #else
1540 		    (void)
1541 #endif
1542 		    bus_space_read_1(iot, ioh, com_data);
1543 #ifdef DIAGNOSTIC
1544 	if (!timo)
1545 		printf("%s: com_iflush timeout %02x\n", sc->sc_dev.dv_xname,
1546 		       reg);
1547 #endif
1548 }
1549 
1550 void
1551 com_loadchannelregs(struct com_softc *sc)
1552 {
1553 	bus_space_tag_t iot = sc->sc_iot;
1554 	bus_space_handle_t ioh = sc->sc_ioh;
1555 
1556 	/* XXXXX necessary? */
1557 	com_iflush(sc);
1558 
1559 	bus_space_write_1(iot, ioh, com_ier, 0);
1560 
1561 	if (ISSET(sc->sc_hwflags, COM_HW_FLOW)) {
1562 		bus_space_write_1(iot, ioh, com_lcr, LCR_EERS);
1563 		bus_space_write_1(iot, ioh, com_efr, sc->sc_efr);
1564 	}
1565 	bus_space_write_1(iot, ioh, com_lcr, sc->sc_lcr | LCR_DLAB);
1566 	bus_space_write_1(iot, ioh, com_dlbl, sc->sc_dlbl);
1567 	bus_space_write_1(iot, ioh, com_dlbh, sc->sc_dlbh);
1568 	bus_space_write_1(iot, ioh, com_lcr, sc->sc_lcr);
1569 	bus_space_write_1(iot, ioh, com_mcr, sc->sc_mcr_active = sc->sc_mcr);
1570 	bus_space_write_1(iot, ioh, com_fifo, sc->sc_fifo);
1571 #ifdef COM_HAYESP
1572 	if (ISSET(sc->sc_hwflags, COM_HW_HAYESP)) {
1573 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD1,
1574 		    HAYESP_SETPRESCALER);
1575 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
1576 		    sc->sc_prescaler);
1577 	}
1578 #endif
1579 
1580 	bus_space_write_1(iot, ioh, com_ier, sc->sc_ier);
1581 }
1582 
1583 int
1584 comhwiflow(struct tty *tp, int block)
1585 {
1586 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(tp->t_dev));
1587 	int s;
1588 
1589 	if (COM_ISALIVE(sc) == 0)
1590 		return (0);
1591 
1592 	if (sc->sc_mcr_rts == 0)
1593 		return (0);
1594 
1595 	s = splserial();
1596 	COM_LOCK(sc);
1597 
1598 	if (block) {
1599 		if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1600 			SET(sc->sc_rx_flags, RX_TTY_BLOCKED);
1601 			com_hwiflow(sc);
1602 		}
1603 	} else {
1604 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
1605 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1606 			com_schedrx(sc);
1607 		}
1608 		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1609 			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED);
1610 			com_hwiflow(sc);
1611 		}
1612 	}
1613 
1614 	COM_UNLOCK(sc);
1615 	splx(s);
1616 	return (1);
1617 }
1618 
1619 /*
1620  * (un)block input via hw flowcontrol
1621  */
1622 void
1623 com_hwiflow(struct com_softc *sc)
1624 {
1625 	bus_space_tag_t iot = sc->sc_iot;
1626 	bus_space_handle_t ioh = sc->sc_ioh;
1627 
1628 	if (sc->sc_mcr_rts == 0)
1629 		return;
1630 
1631 	if (ISSET(sc->sc_rx_flags, RX_ANY_BLOCK)) {
1632 		CLR(sc->sc_mcr, sc->sc_mcr_rts);
1633 		CLR(sc->sc_mcr_active, sc->sc_mcr_rts);
1634 	} else {
1635 		SET(sc->sc_mcr, sc->sc_mcr_rts);
1636 		SET(sc->sc_mcr_active, sc->sc_mcr_rts);
1637 	}
1638 	bus_space_write_1(iot, ioh, com_mcr, sc->sc_mcr_active);
1639 }
1640 
1641 
1642 void
1643 comstart(struct tty *tp)
1644 {
1645 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(tp->t_dev));
1646 	bus_space_tag_t iot = sc->sc_iot;
1647 	bus_space_handle_t ioh = sc->sc_ioh;
1648 	int s;
1649 
1650 	if (COM_ISALIVE(sc) == 0)
1651 		return;
1652 
1653 	s = spltty();
1654 	if (ISSET(tp->t_state, TS_BUSY | TS_TIMEOUT | TS_TTSTOP))
1655 		goto out;
1656 	if (sc->sc_tx_stopped)
1657 		goto out;
1658 
1659 	if (tp->t_outq.c_cc <= tp->t_lowat) {
1660 		if (ISSET(tp->t_state, TS_ASLEEP)) {
1661 			CLR(tp->t_state, TS_ASLEEP);
1662 			wakeup(&tp->t_outq);
1663 		}
1664 		selwakeup(&tp->t_wsel);
1665 		if (tp->t_outq.c_cc == 0)
1666 			goto out;
1667 	}
1668 
1669 	/* Grab the first contiguous region of buffer space. */
1670 	{
1671 		u_char *tba;
1672 		int tbc;
1673 
1674 		tba = tp->t_outq.c_cf;
1675 		tbc = ndqb(&tp->t_outq, 0);
1676 
1677 		(void)splserial();
1678 		COM_LOCK(sc);
1679 
1680 		sc->sc_tba = tba;
1681 		sc->sc_tbc = tbc;
1682 	}
1683 
1684 	SET(tp->t_state, TS_BUSY);
1685 	sc->sc_tx_busy = 1;
1686 
1687 	/* Enable transmit completion interrupts if necessary. */
1688 	if (!ISSET(sc->sc_ier, IER_ETXRDY)) {
1689 		SET(sc->sc_ier, IER_ETXRDY);
1690 		bus_space_write_1(iot, ioh, com_ier, sc->sc_ier);
1691 	}
1692 
1693 	/* Output the first chunk of the contiguous buffer. */
1694 	if (!ISSET(sc->sc_hwflags, COM_HW_NO_TXPRELOAD)) {
1695 		u_int n;
1696 
1697 		n = sc->sc_tbc;
1698 		if (n > sc->sc_fifolen)
1699 			n = sc->sc_fifolen;
1700 		bus_space_write_multi_1(iot, ioh, com_data, sc->sc_tba, n);
1701 		sc->sc_tbc -= n;
1702 		sc->sc_tba += n;
1703 	}
1704 	COM_UNLOCK(sc);
1705 out:
1706 	splx(s);
1707 	return;
1708 }
1709 
1710 /*
1711  * Stop output on a line.
1712  */
1713 void
1714 comstop(struct tty *tp, int flag)
1715 {
1716 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(tp->t_dev));
1717 	int s;
1718 
1719 	s = splserial();
1720 	COM_LOCK(sc);
1721 	if (ISSET(tp->t_state, TS_BUSY)) {
1722 		/* Stop transmitting at the next chunk. */
1723 		sc->sc_tbc = 0;
1724 		sc->sc_heldtbc = 0;
1725 		if (!ISSET(tp->t_state, TS_TTSTOP))
1726 			SET(tp->t_state, TS_FLUSH);
1727 	}
1728 	COM_UNLOCK(sc);
1729 	splx(s);
1730 }
1731 
1732 void
1733 comdiag(void *arg)
1734 {
1735 	struct com_softc *sc = arg;
1736 	int overflows, floods;
1737 	int s;
1738 
1739 	s = splserial();
1740 	COM_LOCK(sc);
1741 	overflows = sc->sc_overflows;
1742 	sc->sc_overflows = 0;
1743 	floods = sc->sc_floods;
1744 	sc->sc_floods = 0;
1745 	sc->sc_errors = 0;
1746 	COM_UNLOCK(sc);
1747 	splx(s);
1748 
1749 	log(LOG_WARNING, "%s: %d silo overflow%s, %d ibuf flood%s\n",
1750 	    sc->sc_dev.dv_xname,
1751 	    overflows, overflows == 1 ? "" : "s",
1752 	    floods, floods == 1 ? "" : "s");
1753 }
1754 
1755 integrate void
1756 com_rxsoft(struct com_softc *sc, struct tty *tp)
1757 {
1758 	int (*rint)(int, struct tty *) = tp->t_linesw->l_rint;
1759 	u_char *get, *end;
1760 	u_int cc, scc;
1761 	u_char lsr;
1762 	int code;
1763 	int s;
1764 
1765 	end = sc->sc_ebuf;
1766 	get = sc->sc_rbget;
1767 	scc = cc = com_rbuf_size - sc->sc_rbavail;
1768 
1769 	if (cc == com_rbuf_size) {
1770 		sc->sc_floods++;
1771 		if (sc->sc_errors++ == 0)
1772 			callout_reset(&sc->sc_diag_callout, 60 * hz,
1773 			    comdiag, sc);
1774 	}
1775 
1776 	/* If not yet open, drop the entire buffer content here */
1777 	if (!ISSET(tp->t_state, TS_ISOPEN)) {
1778 		get += cc << 1;
1779 		if (get >= end)
1780 			get -= com_rbuf_size << 1;
1781 		cc = 0;
1782 	}
1783 	while (cc) {
1784 		code = get[0];
1785 		lsr = get[1];
1786 		if (ISSET(lsr, LSR_OE | LSR_BI | LSR_FE | LSR_PE)) {
1787 			if (ISSET(lsr, LSR_OE)) {
1788 				sc->sc_overflows++;
1789 				if (sc->sc_errors++ == 0)
1790 					callout_reset(&sc->sc_diag_callout,
1791 					    60 * hz, comdiag, sc);
1792 			}
1793 			if (ISSET(lsr, LSR_BI | LSR_FE))
1794 				SET(code, TTY_FE);
1795 			if (ISSET(lsr, LSR_PE))
1796 				SET(code, TTY_PE);
1797 		}
1798 		if ((*rint)(code, tp) == -1) {
1799 			/*
1800 			 * The line discipline's buffer is out of space.
1801 			 */
1802 			if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1803 				/*
1804 				 * We're either not using flow control, or the
1805 				 * line discipline didn't tell us to block for
1806 				 * some reason.  Either way, we have no way to
1807 				 * know when there's more space available, so
1808 				 * just drop the rest of the data.
1809 				 */
1810 				get += cc << 1;
1811 				if (get >= end)
1812 					get -= com_rbuf_size << 1;
1813 				cc = 0;
1814 			} else {
1815 				/*
1816 				 * Don't schedule any more receive processing
1817 				 * until the line discipline tells us there's
1818 				 * space available (through comhwiflow()).
1819 				 * Leave the rest of the data in the input
1820 				 * buffer.
1821 				 */
1822 				SET(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1823 			}
1824 			break;
1825 		}
1826 		get += 2;
1827 		if (get >= end)
1828 			get = sc->sc_rbuf;
1829 		cc--;
1830 	}
1831 
1832 	if (cc != scc) {
1833 		sc->sc_rbget = get;
1834 		s = splserial();
1835 		COM_LOCK(sc);
1836 
1837 		cc = sc->sc_rbavail += scc - cc;
1838 		/* Buffers should be ok again, release possible block. */
1839 		if (cc >= sc->sc_r_lowat) {
1840 			if (ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
1841 				CLR(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
1842 				SET(sc->sc_ier, IER_ERXRDY);
1843 				bus_space_write_1(sc->sc_iot, sc->sc_ioh, com_ier, sc->sc_ier);
1844 			}
1845 			if (ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED)) {
1846 				CLR(sc->sc_rx_flags, RX_IBUF_BLOCKED);
1847 				com_hwiflow(sc);
1848 			}
1849 		}
1850 		COM_UNLOCK(sc);
1851 		splx(s);
1852 	}
1853 }
1854 
1855 integrate void
1856 com_txsoft(struct com_softc *sc, struct tty *tp)
1857 {
1858 
1859 	CLR(tp->t_state, TS_BUSY);
1860 	if (ISSET(tp->t_state, TS_FLUSH))
1861 		CLR(tp->t_state, TS_FLUSH);
1862 	else
1863 		ndflush(&tp->t_outq, (int)(sc->sc_tba - tp->t_outq.c_cf));
1864 	(*tp->t_linesw->l_start)(tp);
1865 }
1866 
1867 integrate void
1868 com_stsoft(struct com_softc *sc, struct tty *tp)
1869 {
1870 	u_char msr, delta;
1871 	int s;
1872 
1873 	s = splserial();
1874 	COM_LOCK(sc);
1875 	msr = sc->sc_msr;
1876 	delta = sc->sc_msr_delta;
1877 	sc->sc_msr_delta = 0;
1878 	COM_UNLOCK(sc);
1879 	splx(s);
1880 
1881 	if (ISSET(delta, sc->sc_msr_dcd)) {
1882 		/*
1883 		 * Inform the tty layer that carrier detect changed.
1884 		 */
1885 		(void) (*tp->t_linesw->l_modem)(tp, ISSET(msr, MSR_DCD));
1886 	}
1887 
1888 	if (ISSET(delta, sc->sc_msr_cts)) {
1889 		/* Block or unblock output according to flow control. */
1890 		if (ISSET(msr, sc->sc_msr_cts)) {
1891 			sc->sc_tx_stopped = 0;
1892 			(*tp->t_linesw->l_start)(tp);
1893 		} else {
1894 			sc->sc_tx_stopped = 1;
1895 		}
1896 	}
1897 
1898 #ifdef COM_DEBUG
1899 	if (com_debug)
1900 		comstatus(sc, "com_stsoft");
1901 #endif
1902 }
1903 
1904 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
1905 void
1906 comsoft(void *arg)
1907 {
1908 	struct com_softc *sc = arg;
1909 	struct tty *tp;
1910 
1911 	if (COM_ISALIVE(sc) == 0)
1912 		return;
1913 
1914 	{
1915 #else
1916 void
1917 #ifndef __NO_SOFT_SERIAL_INTERRUPT
1918 comsoft(void)
1919 #else
1920 comsoft(void *arg)
1921 #endif
1922 {
1923 	struct com_softc	*sc;
1924 	struct tty	*tp;
1925 	int	unit;
1926 #ifdef __NO_SOFT_SERIAL_INTERRUPT
1927 	int s;
1928 
1929 	s = splsoftserial();
1930 	com_softintr_scheduled = 0;
1931 #endif
1932 
1933 	for (unit = 0; unit < com_cd.cd_ndevs; unit++) {
1934 		sc = device_lookup(&com_cd, unit);
1935 		if (sc == NULL || !ISSET(sc->sc_hwflags, COM_HW_DEV_OK))
1936 			continue;
1937 
1938 		if (COM_ISALIVE(sc) == 0)
1939 			continue;
1940 
1941 		tp = sc->sc_tty;
1942 		if (tp == NULL)
1943 			continue;
1944 		if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0)
1945 			continue;
1946 #endif
1947 		tp = sc->sc_tty;
1948 
1949 		if (sc->sc_rx_ready) {
1950 			sc->sc_rx_ready = 0;
1951 			com_rxsoft(sc, tp);
1952 		}
1953 
1954 		if (sc->sc_st_check) {
1955 			sc->sc_st_check = 0;
1956 			com_stsoft(sc, tp);
1957 		}
1958 
1959 		if (sc->sc_tx_done) {
1960 			sc->sc_tx_done = 0;
1961 			com_txsoft(sc, tp);
1962 		}
1963 	}
1964 
1965 #ifndef __HAVE_GENERIC_SOFT_INTERRUPTS
1966 #ifdef __NO_SOFT_SERIAL_INTERRUPT
1967 	splx(s);
1968 #endif
1969 #endif
1970 }
1971 
1972 #ifdef __ALIGN_BRACKET_LEVEL_FOR_CTAGS
1973 	/* there has got to be a better way to do comsoft() */
1974 }}
1975 #endif
1976 
1977 int
1978 comintr(void *arg)
1979 {
1980 	struct com_softc *sc = arg;
1981 	bus_space_tag_t iot = sc->sc_iot;
1982 	bus_space_handle_t ioh = sc->sc_ioh;
1983 	u_char *put, *end;
1984 	u_int cc;
1985 	u_char lsr, iir;
1986 
1987 	if (COM_ISALIVE(sc) == 0)
1988 		return (0);
1989 
1990 	COM_LOCK(sc);
1991 	iir = bus_space_read_1(iot, ioh, com_iir);
1992 	if (ISSET(iir, IIR_NOPEND)) {
1993 		COM_UNLOCK(sc);
1994 		return (0);
1995 	}
1996 
1997 	end = sc->sc_ebuf;
1998 	put = sc->sc_rbput;
1999 	cc = sc->sc_rbavail;
2000 
2001 again:	do {
2002 		u_char	msr, delta;
2003 
2004 		lsr = bus_space_read_1(iot, ioh, com_lsr);
2005 		if (ISSET(lsr, LSR_BI)) {
2006 			int cn_trapped = 0;
2007 			cn_check_magic(sc->sc_tty->t_dev,
2008 				       CNC_BREAK, com_cnm_state);
2009 			if (cn_trapped)
2010 				continue;
2011 #if defined(KGDB) && !defined(DDB)
2012 			if (ISSET(sc->sc_hwflags, COM_HW_KGDB)) {
2013 				kgdb_connect(1);
2014 				continue;
2015 			}
2016 #endif
2017 		}
2018 
2019 		if (ISSET(lsr, LSR_RCV_MASK) &&
2020 		    !ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
2021 			while (cc > 0) {
2022 				int cn_trapped = 0;
2023 				put[0] = bus_space_read_1(iot, ioh, com_data);
2024 				put[1] = lsr;
2025 				cn_check_magic(sc->sc_tty->t_dev,
2026 					       put[0], com_cnm_state);
2027 				if (cn_trapped) {
2028 					lsr = bus_space_read_1(iot, ioh, com_lsr);
2029 					if (!ISSET(lsr, LSR_RCV_MASK))
2030 						break;
2031 
2032 					continue;
2033 				}
2034 				put += 2;
2035 				if (put >= end)
2036 					put = sc->sc_rbuf;
2037 				cc--;
2038 
2039 				lsr = bus_space_read_1(iot, ioh, com_lsr);
2040 				if (!ISSET(lsr, LSR_RCV_MASK))
2041 					break;
2042 			}
2043 
2044 			/*
2045 			 * Current string of incoming characters ended because
2046 			 * no more data was available or we ran out of space.
2047 			 * Schedule a receive event if any data was received.
2048 			 * If we're out of space, turn off receive interrupts.
2049 			 */
2050 			sc->sc_rbput = put;
2051 			sc->sc_rbavail = cc;
2052 			if (!ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED))
2053 				sc->sc_rx_ready = 1;
2054 
2055 			/*
2056 			 * See if we are in danger of overflowing a buffer. If
2057 			 * so, use hardware flow control to ease the pressure.
2058 			 */
2059 			if (!ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED) &&
2060 			    cc < sc->sc_r_hiwat) {
2061 				SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
2062 				com_hwiflow(sc);
2063 			}
2064 
2065 			/*
2066 			 * If we're out of space, disable receive interrupts
2067 			 * until the queue has drained a bit.
2068 			 */
2069 			if (!cc) {
2070 				SET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
2071 				CLR(sc->sc_ier, IER_ERXRDY);
2072 				bus_space_write_1(iot, ioh, com_ier, sc->sc_ier);
2073 			}
2074 		} else {
2075 			if ((iir & IIR_IMASK) == IIR_RXRDY) {
2076 				bus_space_write_1(iot, ioh, com_ier, 0);
2077 				delay(10);
2078 				bus_space_write_1(iot, ioh, com_ier,sc->sc_ier);
2079 				continue;
2080 			}
2081 		}
2082 
2083 		msr = bus_space_read_1(iot, ioh, com_msr);
2084 		delta = msr ^ sc->sc_msr;
2085 		sc->sc_msr = msr;
2086 		/*
2087 		 * Pulse-per-second (PSS) signals on edge of DCD?
2088 		 * Process these even if line discipline is ignoring DCD.
2089 		 */
2090 		if (delta & sc->sc_ppsmask) {
2091 			struct timeval tv;
2092 		    	if ((msr & sc->sc_ppsmask) == sc->sc_ppsassert) {
2093 				/* XXX nanotime() */
2094 				microtime(&tv);
2095 				TIMEVAL_TO_TIMESPEC(&tv,
2096 				    &sc->ppsinfo.assert_timestamp);
2097 				if (sc->ppsparam.mode & PPS_OFFSETASSERT) {
2098 					timespecadd(&sc->ppsinfo.assert_timestamp,
2099 					    &sc->ppsparam.assert_offset,
2100 						    &sc->ppsinfo.assert_timestamp);
2101 				}
2102 
2103 #ifdef PPS_SYNC
2104 				if (sc->ppsparam.mode & PPS_HARDPPSONASSERT)
2105 					hardpps(&tv, tv.tv_usec);
2106 #endif
2107 				sc->ppsinfo.assert_sequence++;
2108 				sc->ppsinfo.current_mode = sc->ppsparam.mode;
2109 
2110 			} else if ((msr & sc->sc_ppsmask) == sc->sc_ppsclear) {
2111 				/* XXX nanotime() */
2112 				microtime(&tv);
2113 				TIMEVAL_TO_TIMESPEC(&tv,
2114 				    &sc->ppsinfo.clear_timestamp);
2115 				if (sc->ppsparam.mode & PPS_OFFSETCLEAR) {
2116 					timespecadd(&sc->ppsinfo.clear_timestamp,
2117 					    &sc->ppsparam.clear_offset,
2118 					    &sc->ppsinfo.clear_timestamp);
2119 				}
2120 
2121 #ifdef PPS_SYNC
2122 				if (sc->ppsparam.mode & PPS_HARDPPSONCLEAR)
2123 					hardpps(&tv, tv.tv_usec);
2124 #endif
2125 				sc->ppsinfo.clear_sequence++;
2126 				sc->ppsinfo.current_mode = sc->ppsparam.mode;
2127 			}
2128 		}
2129 
2130 		/*
2131 		 * Process normal status changes
2132 		 */
2133 		if (ISSET(delta, sc->sc_msr_mask)) {
2134 			SET(sc->sc_msr_delta, delta);
2135 
2136 			/*
2137 			 * Stop output immediately if we lose the output
2138 			 * flow control signal or carrier detect.
2139 			 */
2140 			if (ISSET(~msr, sc->sc_msr_mask)) {
2141 				sc->sc_tbc = 0;
2142 				sc->sc_heldtbc = 0;
2143 #ifdef COM_DEBUG
2144 				if (com_debug)
2145 					comstatus(sc, "comintr  ");
2146 #endif
2147 			}
2148 
2149 			sc->sc_st_check = 1;
2150 		}
2151 	} while (ISSET((iir = bus_space_read_1(iot, ioh, com_iir)), IIR_RXRDY)
2152 	    || ((iir & IIR_IMASK) == 0));
2153 
2154 	/*
2155 	 * Done handling any receive interrupts. See if data can be
2156 	 * transmitted as well. Schedule tx done event if no data left
2157 	 * and tty was marked busy.
2158 	 */
2159 	if (ISSET(lsr, LSR_TXRDY)) {
2160 		/*
2161 		 * If we've delayed a parameter change, do it now, and restart
2162 		 * output.
2163 		 */
2164 		if (sc->sc_heldchange) {
2165 			com_loadchannelregs(sc);
2166 			sc->sc_heldchange = 0;
2167 			sc->sc_tbc = sc->sc_heldtbc;
2168 			sc->sc_heldtbc = 0;
2169 		}
2170 
2171 		/* Output the next chunk of the contiguous buffer, if any. */
2172 		if (sc->sc_tbc > 0) {
2173 			u_int n;
2174 
2175 			n = sc->sc_tbc;
2176 			if (n > sc->sc_fifolen)
2177 				n = sc->sc_fifolen;
2178 			bus_space_write_multi_1(iot, ioh, com_data, sc->sc_tba, n);
2179 			sc->sc_tbc -= n;
2180 			sc->sc_tba += n;
2181 		} else {
2182 			/* Disable transmit completion interrupts if necessary. */
2183 			if (ISSET(sc->sc_ier, IER_ETXRDY)) {
2184 				CLR(sc->sc_ier, IER_ETXRDY);
2185 				bus_space_write_1(iot, ioh, com_ier, sc->sc_ier);
2186 			}
2187 			if (sc->sc_tx_busy) {
2188 				sc->sc_tx_busy = 0;
2189 				sc->sc_tx_done = 1;
2190 			}
2191 		}
2192 	}
2193 
2194 	if (!ISSET((iir = bus_space_read_1(iot, ioh, com_iir)), IIR_NOPEND))
2195 		goto again;
2196 
2197 	COM_UNLOCK(sc);
2198 
2199 	/* Wake up the poller. */
2200 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
2201 	softintr_schedule(sc->sc_si);
2202 #else
2203 #ifndef __NO_SOFT_SERIAL_INTERRUPT
2204 	setsoftserial();
2205 #else
2206 	if (!com_softintr_scheduled) {
2207 		com_softintr_scheduled = 1;
2208 		callout_reset(&comsoft_callout, 1, comsoft, NULL);
2209 	}
2210 #endif
2211 #endif
2212 
2213 #if NRND > 0 && defined(RND_COM)
2214 	rnd_add_uint32(&sc->rnd_source, iir | lsr);
2215 #endif
2216 
2217 	return (1);
2218 }
2219 
2220 /*
2221  * The following functions are polled getc and putc routines, shared
2222  * by the console and kgdb glue.
2223  *
2224  * The read-ahead code is so that you can detect pending in-band
2225  * cn_magic in polled mode while doing output rather than having to
2226  * wait until the kernel decides it needs input.
2227  */
2228 
2229 #define MAX_READAHEAD	20
2230 static int com_readahead[MAX_READAHEAD];
2231 static int com_readaheadcount = 0;
2232 
2233 int
2234 com_common_getc(dev_t dev, bus_space_tag_t iot, bus_space_handle_t ioh)
2235 {
2236 	int s = splserial();
2237 	u_char stat, c;
2238 
2239 	/* got a character from reading things earlier */
2240 	if (com_readaheadcount > 0) {
2241 		int i;
2242 
2243 		c = com_readahead[0];
2244 		for (i = 1; i < com_readaheadcount; i++) {
2245 			com_readahead[i-1] = com_readahead[i];
2246 		}
2247 		com_readaheadcount--;
2248 		splx(s);
2249 		return (c);
2250 	}
2251 
2252 	/* block until a character becomes available */
2253 	while (!ISSET(stat = bus_space_read_1(iot, ioh, com_lsr), LSR_RXRDY))
2254 		;
2255 
2256 	c = bus_space_read_1(iot, ioh, com_data);
2257 	stat = bus_space_read_1(iot, ioh, com_iir);
2258 	{
2259 		int cn_trapped = 0; /* unused */
2260 #ifdef DDB
2261 		extern int db_active;
2262 		if (!db_active)
2263 #endif
2264 			cn_check_magic(dev, c, com_cnm_state);
2265 	}
2266 	splx(s);
2267 	return (c);
2268 }
2269 
2270 void
2271 com_common_putc(dev_t dev, bus_space_tag_t iot, bus_space_handle_t ioh, int c)
2272 {
2273 	int s = splserial();
2274 	int cin, stat, timo;
2275 
2276 	if (com_readaheadcount < MAX_READAHEAD
2277 	     && ISSET(stat = bus_space_read_1(iot, ioh, com_lsr), LSR_RXRDY)) {
2278 		int cn_trapped = 0;
2279 		cin = bus_space_read_1(iot, ioh, com_data);
2280 		stat = bus_space_read_1(iot, ioh, com_iir);
2281 		cn_check_magic(dev, cin, com_cnm_state);
2282 		com_readahead[com_readaheadcount++] = cin;
2283 	}
2284 
2285 	/* wait for any pending transmission to finish */
2286 	timo = 150000;
2287 	while (!ISSET(bus_space_read_1(iot, ioh, com_lsr), LSR_TXRDY) && --timo)
2288 		continue;
2289 
2290 	bus_space_write_1(iot, ioh, com_data, c);
2291 	COM_BARRIER(iot, ioh, BR | BW);
2292 
2293 	/* wait for this transmission to complete */
2294 	timo = 1500000;
2295 	while (!ISSET(bus_space_read_1(iot, ioh, com_lsr), LSR_TXRDY) && --timo)
2296 		continue;
2297 
2298 	splx(s);
2299 }
2300 
2301 /*
2302  * Initialize UART for use as console or KGDB line.
2303  */
2304 int
2305 cominit(bus_space_tag_t iot, bus_addr_t iobase, int rate, int frequency,
2306     tcflag_t cflag, bus_space_handle_t *iohp)
2307 {
2308 	bus_space_handle_t ioh;
2309 
2310 	if (bus_space_map(iot, iobase, COM_NPORTS, 0, &ioh))
2311 		return (ENOMEM); /* ??? */
2312 
2313 	bus_space_write_1(iot, ioh, com_lcr, LCR_EERS);
2314 	bus_space_write_1(iot, ioh, com_efr, 0);
2315 	bus_space_write_1(iot, ioh, com_lcr, LCR_DLAB);
2316 	rate = comspeed(rate, frequency);
2317 	bus_space_write_1(iot, ioh, com_dlbl, rate);
2318 	bus_space_write_1(iot, ioh, com_dlbh, rate >> 8);
2319 	bus_space_write_1(iot, ioh, com_lcr, cflag2lcr(cflag));
2320 	bus_space_write_1(iot, ioh, com_mcr, MCR_DTR | MCR_RTS);
2321 	bus_space_write_1(iot, ioh, com_fifo,
2322 	    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_1);
2323 	bus_space_write_1(iot, ioh, com_ier, 0);
2324 
2325 	*iohp = ioh;
2326 	return (0);
2327 }
2328 
2329 /*
2330  * Following are all routines needed for COM to act as console
2331  */
2332 struct consdev comcons = {
2333 	NULL, NULL, comcngetc, comcnputc, comcnpollc, NULL, NULL, NULL,
2334 	NODEV, CN_NORMAL
2335 };
2336 
2337 
2338 int
2339 comcnattach(bus_space_tag_t iot, bus_addr_t iobase, int rate, int frequency,
2340     tcflag_t cflag)
2341 {
2342 	int res;
2343 
2344 	res = cominit(iot, iobase, rate, frequency, cflag, &comconsioh);
2345 	if (res)
2346 		return (res);
2347 
2348 	cn_tab = &comcons;
2349 	cn_init_magic(&com_cnm_state);
2350 	cn_set_magic("\047\001"); /* default magic is BREAK */
2351 
2352 	comconstag = iot;
2353 	comconsaddr = iobase;
2354 	comconsrate = rate;
2355 	comconscflag = cflag;
2356 
2357 	return (0);
2358 }
2359 
2360 int
2361 comcngetc(dev_t dev)
2362 {
2363 
2364 	return (com_common_getc(dev, comconstag, comconsioh));
2365 }
2366 
2367 /*
2368  * Console kernel output character routine.
2369  */
2370 void
2371 comcnputc(dev_t dev, int c)
2372 {
2373 
2374 	com_common_putc(dev, comconstag, comconsioh, c);
2375 }
2376 
2377 void
2378 comcnpollc(dev_t dev, int on)
2379 {
2380 
2381 }
2382 
2383 #ifdef KGDB
2384 int
2385 com_kgdb_attach(bus_space_tag_t iot, bus_addr_t iobase, int rate,
2386     int frequency, tcflag_t cflag)
2387 {
2388 	int res;
2389 
2390 	if (iot == comconstag && iobase == comconsaddr) {
2391 #if !defined(DDB)
2392 		return (EBUSY); /* cannot share with console */
2393 #else
2394 		com_kgdb_ioh = comconsioh;
2395 #endif
2396 	} else {
2397 
2398 		res = cominit(iot, iobase, rate, frequency, cflag,
2399 			      &com_kgdb_ioh);
2400 		if (res)
2401 			return (res);
2402 
2403 		/*
2404 		 * XXXfvdl this shouldn't be needed, but the cn_magic goo
2405 		 * expects this to be initialized
2406 		 */
2407 		cn_init_magic(&com_cnm_state);
2408 		cn_set_magic("\047\001");
2409 	}
2410 
2411 	kgdb_attach(com_kgdb_getc, com_kgdb_putc, NULL);
2412 	kgdb_dev = 123; /* unneeded, only to satisfy some tests */
2413 
2414 	com_kgdb_iot = iot;
2415 	com_kgdb_addr = iobase;
2416 
2417 	return (0);
2418 }
2419 
2420 /* ARGSUSED */
2421 int
2422 com_kgdb_getc(void *arg)
2423 {
2424 
2425 	return (com_common_getc(NODEV, com_kgdb_iot, com_kgdb_ioh));
2426 }
2427 
2428 /* ARGSUSED */
2429 void
2430 com_kgdb_putc(void *arg, int c)
2431 {
2432 
2433 	com_common_putc(NODEV, com_kgdb_iot, com_kgdb_ioh, c);
2434 }
2435 #endif /* KGDB */
2436 
2437 /* helper function to identify the com ports used by
2438  console or KGDB (and not yet autoconf attached) */
2439 int
2440 com_is_console(bus_space_tag_t iot, bus_addr_t iobase, bus_space_handle_t *ioh)
2441 {
2442 	bus_space_handle_t help;
2443 
2444 	if (!comconsattached &&
2445 	    iot == comconstag && iobase == comconsaddr)
2446 		help = comconsioh;
2447 #ifdef KGDB
2448 	else if (!com_kgdb_attached &&
2449 	    iot == com_kgdb_iot && iobase == com_kgdb_addr)
2450 		help = com_kgdb_ioh;
2451 #endif
2452 	else
2453 		return (0);
2454 
2455 	if (ioh)
2456 		*ioh = help;
2457 	return (1);
2458 }
2459