xref: /netbsd/sys/dev/ic/com.c (revision c4a72b64)
1 /*	$NetBSD: com.c,v 1.201 2002/11/07 08:07:26 thorpej 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 1.201 2002/11/07 08:07:26 thorpej 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 				printf(": st16650, broken fifo\n");
512 			else if (sc->sc_fifolen == 32)
513 				printf(": st16650a, working fifo\n");
514 			else
515 #endif
516 				printf(": ns16550a, working fifo\n");
517 		} else
518 			printf(": ns16550, broken fifo\n");
519 	else
520 		printf(": 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 		printf("%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 		printf("%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 		printf("%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 	 * the kgdb device, it has exclusive use.
566 	 */
567 	if (iot == com_kgdb_iot && iobase == com_kgdb_addr) {
568 		com_kgdb_attached = 1;
569 
570 		SET(sc->sc_hwflags, COM_HW_KGDB);
571 		printf("%s: kgdb\n", sc->sc_dev.dv_xname);
572 	}
573 #endif
574 
575 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
576 	sc->sc_si = softintr_establish(IPL_SOFTSERIAL, comsoft, sc);
577 #endif
578 
579 #if NRND > 0 && defined(RND_COM)
580 	rnd_attach_source(&sc->rnd_source, sc->sc_dev.dv_xname,
581 			  RND_TYPE_TTY, 0);
582 #endif
583 
584 	/* if there are no enable/disable functions, assume the device
585 	   is always enabled */
586 	if (!sc->enable)
587 		sc->enabled = 1;
588 
589 	com_config(sc);
590 
591 	SET(sc->sc_hwflags, COM_HW_DEV_OK);
592 }
593 
594 void
595 com_config(struct com_softc *sc)
596 {
597 	bus_space_tag_t iot = sc->sc_iot;
598 	bus_space_handle_t ioh = sc->sc_ioh;
599 
600 	/* Disable interrupts before configuring the device. */
601 	sc->sc_ier = 0;
602 	bus_space_write_1(iot, ioh, com_ier, sc->sc_ier);
603 
604 #ifdef COM_HAYESP
605 	/* Look for a Hayes ESP board. */
606 	if (ISSET(sc->sc_hwflags, COM_HW_HAYESP)) {
607 		sc->sc_fifolen = 1024;
608 
609 		/* Set 16550 compatibility mode */
610 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD1,
611 				  HAYESP_SETMODE);
612 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
613 				  HAYESP_MODE_FIFO|HAYESP_MODE_RTS|
614 				  HAYESP_MODE_SCALE);
615 
616 		/* Set RTS/CTS flow control */
617 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD1,
618 				  HAYESP_SETFLOWTYPE);
619 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
620 				  HAYESP_FLOW_RTS);
621 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
622 				  HAYESP_FLOW_CTS);
623 
624 		/* Set flow control levels */
625 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD1,
626 				  HAYESP_SETRXFLOW);
627 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
628 				  HAYESP_HIBYTE(HAYESP_RXHIWMARK));
629 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
630 				  HAYESP_LOBYTE(HAYESP_RXHIWMARK));
631 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
632 				  HAYESP_HIBYTE(HAYESP_RXLOWMARK));
633 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
634 				  HAYESP_LOBYTE(HAYESP_RXLOWMARK));
635 	}
636 #endif
637 
638 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE|COM_HW_KGDB))
639 		com_enable_debugport(sc);
640 }
641 
642 int
643 com_detach(struct device *self, int flags)
644 {
645 	struct com_softc *sc = (struct com_softc *)self;
646 	int maj, mn;
647 
648 	/* locate the major number */
649 	maj = cdevsw_lookup_major(&com_cdevsw);
650 
651 	/* Nuke the vnodes for any open instances. */
652 	mn = self->dv_unit;
653 	vdevgone(maj, mn, mn, VCHR);
654 
655 	mn |= COMDIALOUT_MASK;
656 	vdevgone(maj, mn, mn, VCHR);
657 
658 	if (sc->sc_rbuf == NULL) {
659 		/*
660 		 * Ring buffer allocation failed in the com_attach_subr,
661 		 * only the tty is allocated, and nothing else.
662 		 */
663 		ttyfree(sc->sc_tty);
664 		return 0;
665 	}
666 
667 	/* Free the receive buffer. */
668 	free(sc->sc_rbuf, M_DEVBUF);
669 
670 	/* Detach and free the tty. */
671 	tty_detach(sc->sc_tty);
672 	ttyfree(sc->sc_tty);
673 
674 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
675 	/* Unhook the soft interrupt handler. */
676 	softintr_disestablish(sc->sc_si);
677 #endif
678 
679 #if NRND > 0 && defined(RND_COM)
680 	/* Unhook the entropy source. */
681 	rnd_detach_source(&sc->rnd_source);
682 #endif
683 
684 	return (0);
685 }
686 
687 int
688 com_activate(struct device *self, enum devact act)
689 {
690 	struct com_softc *sc = (struct com_softc *)self;
691 	int s, rv = 0;
692 
693 	s = splserial();
694 	COM_LOCK(sc);
695 	switch (act) {
696 	case DVACT_ACTIVATE:
697 		rv = EOPNOTSUPP;
698 		break;
699 
700 	case DVACT_DEACTIVATE:
701 		if (sc->sc_hwflags & (COM_HW_CONSOLE|COM_HW_KGDB)) {
702 			rv = EBUSY;
703 			break;
704 		}
705 
706 		if (sc->disable != NULL && sc->enabled != 0) {
707 			(*sc->disable)(sc);
708 			sc->enabled = 0;
709 		}
710 		break;
711 	}
712 
713 	COM_UNLOCK(sc);
714 	splx(s);
715 	return (rv);
716 }
717 
718 void
719 com_shutdown(struct com_softc *sc)
720 {
721 	struct tty *tp = sc->sc_tty;
722 	int s;
723 
724 	s = splserial();
725 	COM_LOCK(sc);
726 
727 	/* If we were asserting flow control, then deassert it. */
728 	SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
729 	com_hwiflow(sc);
730 
731 	/* Clear any break condition set with TIOCSBRK. */
732 	com_break(sc, 0);
733 
734 	/* Turn off PPS capture on last close. */
735 	sc->sc_ppsmask = 0;
736 	sc->ppsparam.mode = 0;
737 
738 	/*
739 	 * Hang up if necessary.  Wait a bit, so the other side has time to
740 	 * notice even if we immediately open the port again.
741 	 * Avoid tsleeping above splhigh().
742 	 */
743 	if (ISSET(tp->t_cflag, HUPCL)) {
744 		com_modem(sc, 0);
745 		COM_UNLOCK(sc);
746 		splx(s);
747 		/* XXX tsleep will only timeout */
748 		(void) tsleep(sc, TTIPRI, ttclos, hz);
749 		s = splserial();
750 		COM_LOCK(sc);
751 	}
752 
753 	/* Turn off interrupts. */
754 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE))
755 		sc->sc_ier = IER_ERXRDY; /* interrupt on break */
756 	else
757 		sc->sc_ier = 0;
758 	bus_space_write_1(sc->sc_iot, sc->sc_ioh, com_ier, sc->sc_ier);
759 
760 	if (sc->disable) {
761 #ifdef DIAGNOSTIC
762 		if (!sc->enabled)
763 			panic("com_shutdown: not enabled?");
764 #endif
765 		(*sc->disable)(sc);
766 		sc->enabled = 0;
767 	}
768 	COM_UNLOCK(sc);
769 	splx(s);
770 }
771 
772 int
773 comopen(dev_t dev, int flag, int mode, struct proc *p)
774 {
775 	struct com_softc *sc;
776 	struct tty *tp;
777 	int s, s2;
778 	int error;
779 
780 	sc = device_lookup(&com_cd, COMUNIT(dev));
781 	if (sc == NULL || !ISSET(sc->sc_hwflags, COM_HW_DEV_OK) ||
782 		sc->sc_rbuf == NULL)
783 		return (ENXIO);
784 
785 	if (ISSET(sc->sc_dev.dv_flags, DVF_ACTIVE) == 0)
786 		return (ENXIO);
787 
788 #ifdef KGDB
789 	/*
790 	 * If this is the kgdb port, no other use is permitted.
791 	 */
792 	if (ISSET(sc->sc_hwflags, COM_HW_KGDB))
793 		return (EBUSY);
794 #endif
795 
796 	tp = sc->sc_tty;
797 
798 	if (ISSET(tp->t_state, TS_ISOPEN) &&
799 	    ISSET(tp->t_state, TS_XCLUDE) &&
800 		p->p_ucred->cr_uid != 0)
801 		return (EBUSY);
802 
803 	s = spltty();
804 
805 	/*
806 	 * Do the following iff this is a first open.
807 	 */
808 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
809 		struct termios t;
810 
811 		tp->t_dev = dev;
812 
813 		s2 = splserial();
814 		COM_LOCK(sc);
815 
816 		if (sc->enable) {
817 			if ((*sc->enable)(sc)) {
818 				COM_UNLOCK(sc);
819 				splx(s2);
820 				splx(s);
821 				printf("%s: device enable failed\n",
822 				       sc->sc_dev.dv_xname);
823 				return (EIO);
824 			}
825 			sc->enabled = 1;
826 			com_config(sc);
827 		}
828 
829 		/* Turn on interrupts. */
830 		sc->sc_ier = IER_ERXRDY | IER_ERLS | IER_EMSC;
831 		bus_space_write_1(sc->sc_iot, sc->sc_ioh, com_ier, sc->sc_ier);
832 
833 		/* Fetch the current modem control status, needed later. */
834 		sc->sc_msr = bus_space_read_1(sc->sc_iot, sc->sc_ioh, com_msr);
835 
836 		/* Clear PPS capture state on first open. */
837 		sc->sc_ppsmask = 0;
838 		sc->ppsparam.mode = 0;
839 
840 		COM_UNLOCK(sc);
841 		splx(s2);
842 
843 		/*
844 		 * Initialize the termios status to the defaults.  Add in the
845 		 * sticky bits from TIOCSFLAGS.
846 		 */
847 		t.c_ispeed = 0;
848 		if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
849 			t.c_ospeed = comconsrate;
850 			t.c_cflag = comconscflag;
851 		} else {
852 			t.c_ospeed = TTYDEF_SPEED;
853 			t.c_cflag = TTYDEF_CFLAG;
854 		}
855 		if (ISSET(sc->sc_swflags, TIOCFLAG_CLOCAL))
856 			SET(t.c_cflag, CLOCAL);
857 		if (ISSET(sc->sc_swflags, TIOCFLAG_CRTSCTS))
858 			SET(t.c_cflag, CRTSCTS);
859 		if (ISSET(sc->sc_swflags, TIOCFLAG_MDMBUF))
860 			SET(t.c_cflag, MDMBUF);
861 		/* Make sure comparam() will do something. */
862 		tp->t_ospeed = 0;
863 		(void) comparam(tp, &t);
864 		tp->t_iflag = TTYDEF_IFLAG;
865 		tp->t_oflag = TTYDEF_OFLAG;
866 		tp->t_lflag = TTYDEF_LFLAG;
867 		ttychars(tp);
868 		ttsetwater(tp);
869 
870 		s2 = splserial();
871 		COM_LOCK(sc);
872 
873 		/*
874 		 * Turn on DTR.  We must always do this, even if carrier is not
875 		 * present, because otherwise we'd have to use TIOCSDTR
876 		 * immediately after setting CLOCAL, which applications do not
877 		 * expect.  We always assert DTR while the device is open
878 		 * unless explicitly requested to deassert it.
879 		 */
880 		com_modem(sc, 1);
881 
882 		/* Clear the input ring, and unblock. */
883 		sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
884 		sc->sc_rbavail = com_rbuf_size;
885 		com_iflush(sc);
886 		CLR(sc->sc_rx_flags, RX_ANY_BLOCK);
887 		com_hwiflow(sc);
888 
889 #ifdef COM_DEBUG
890 		if (com_debug)
891 			comstatus(sc, "comopen  ");
892 #endif
893 
894 		COM_UNLOCK(sc);
895 		splx(s2);
896 	}
897 
898 	splx(s);
899 
900 	error = ttyopen(tp, COMDIALOUT(dev), ISSET(flag, O_NONBLOCK));
901 	if (error)
902 		goto bad;
903 
904 	error = (*tp->t_linesw->l_open)(dev, tp);
905 	if (error)
906 		goto bad;
907 
908 	return (0);
909 
910 bad:
911 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
912 		/*
913 		 * We failed to open the device, and nobody else had it opened.
914 		 * Clean up the state as appropriate.
915 		 */
916 		com_shutdown(sc);
917 	}
918 
919 	return (error);
920 }
921 
922 int
923 comclose(dev_t dev, int flag, int mode, struct proc *p)
924 {
925 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(dev));
926 	struct tty *tp = sc->sc_tty;
927 
928 	/* XXX This is for cons.c. */
929 	if (!ISSET(tp->t_state, TS_ISOPEN))
930 		return (0);
931 
932 	(*tp->t_linesw->l_close)(tp, flag);
933 	ttyclose(tp);
934 
935 	if (COM_ISALIVE(sc) == 0)
936 		return (0);
937 
938 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
939 		/*
940 		 * Although we got a last close, the device may still be in
941 		 * use; e.g. if this was the dialout node, and there are still
942 		 * processes waiting for carrier on the non-dialout node.
943 		 */
944 		com_shutdown(sc);
945 	}
946 
947 	return (0);
948 }
949 
950 int
951 comread(dev_t dev, struct uio *uio, int flag)
952 {
953 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(dev));
954 	struct tty *tp = sc->sc_tty;
955 
956 	if (COM_ISALIVE(sc) == 0)
957 		return (EIO);
958 
959 	return ((*tp->t_linesw->l_read)(tp, uio, flag));
960 }
961 
962 int
963 comwrite(dev_t dev, struct uio *uio, int flag)
964 {
965 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(dev));
966 	struct tty *tp = sc->sc_tty;
967 
968 	if (COM_ISALIVE(sc) == 0)
969 		return (EIO);
970 
971 	return ((*tp->t_linesw->l_write)(tp, uio, flag));
972 }
973 
974 int
975 compoll(dev_t dev, int events, struct proc *p)
976 {
977 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(dev));
978 	struct tty *tp = sc->sc_tty;
979 
980 	if (COM_ISALIVE(sc) == 0)
981 		return (EIO);
982 
983 	return ((*tp->t_linesw->l_poll)(tp, events, p));
984 }
985 
986 struct tty *
987 comtty(dev_t dev)
988 {
989 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(dev));
990 	struct tty *tp = sc->sc_tty;
991 
992 	return (tp);
993 }
994 
995 int
996 comioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct proc *p)
997 {
998 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(dev));
999 	struct tty *tp = sc->sc_tty;
1000 	int error;
1001 	int s;
1002 
1003 	if (COM_ISALIVE(sc) == 0)
1004 		return (EIO);
1005 
1006 	error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, p);
1007 	if (error != EPASSTHROUGH)
1008 		return (error);
1009 
1010 	error = ttioctl(tp, cmd, data, flag, p);
1011 	if (error != EPASSTHROUGH)
1012 		return (error);
1013 
1014 	error = 0;
1015 
1016 	s = splserial();
1017 	COM_LOCK(sc);
1018 
1019 	switch (cmd) {
1020 	case TIOCSBRK:
1021 		com_break(sc, 1);
1022 		break;
1023 
1024 	case TIOCCBRK:
1025 		com_break(sc, 0);
1026 		break;
1027 
1028 	case TIOCSDTR:
1029 		com_modem(sc, 1);
1030 		break;
1031 
1032 	case TIOCCDTR:
1033 		com_modem(sc, 0);
1034 		break;
1035 
1036 	case TIOCGFLAGS:
1037 		*(int *)data = sc->sc_swflags;
1038 		break;
1039 
1040 	case TIOCSFLAGS:
1041 		error = suser(p->p_ucred, &p->p_acflag);
1042 		if (error)
1043 			break;
1044 		sc->sc_swflags = *(int *)data;
1045 		break;
1046 
1047 	case TIOCMSET:
1048 	case TIOCMBIS:
1049 	case TIOCMBIC:
1050 		tiocm_to_com(sc, cmd, *(int *)data);
1051 		break;
1052 
1053 	case TIOCMGET:
1054 		*(int *)data = com_to_tiocm(sc);
1055 		break;
1056 
1057 	case PPS_IOC_CREATE:
1058 		break;
1059 
1060 	case PPS_IOC_DESTROY:
1061 		break;
1062 
1063 	case PPS_IOC_GETPARAMS: {
1064 		pps_params_t *pp;
1065 		pp = (pps_params_t *)data;
1066 		*pp = sc->ppsparam;
1067 		break;
1068 	}
1069 
1070 	case PPS_IOC_SETPARAMS: {
1071 	  	pps_params_t *pp;
1072 		int mode;
1073 		pp = (pps_params_t *)data;
1074 		if (pp->mode & ~ppscap) {
1075 			error = EINVAL;
1076 			break;
1077 		}
1078 		sc->ppsparam = *pp;
1079 	 	/*
1080 		 * Compute msr masks from user-specified timestamp state.
1081 		 */
1082 		mode = sc->ppsparam.mode;
1083 #ifdef	PPS_SYNC
1084 		if (mode & PPS_HARDPPSONASSERT) {
1085 			mode |= PPS_CAPTUREASSERT;
1086 			/* XXX revoke any previous HARDPPS source */
1087 		}
1088 		if (mode & PPS_HARDPPSONCLEAR) {
1089 			mode |= PPS_CAPTURECLEAR;
1090 			/* XXX revoke any previous HARDPPS source */
1091 		}
1092 #endif	/* PPS_SYNC */
1093 		switch (mode & PPS_CAPTUREBOTH) {
1094 		case 0:
1095 			sc->sc_ppsmask = 0;
1096 			break;
1097 
1098 		case PPS_CAPTUREASSERT:
1099 			sc->sc_ppsmask = MSR_DCD;
1100 			sc->sc_ppsassert = MSR_DCD;
1101 			sc->sc_ppsclear = -1;
1102 			break;
1103 
1104 		case PPS_CAPTURECLEAR:
1105 			sc->sc_ppsmask = MSR_DCD;
1106 			sc->sc_ppsassert = -1;
1107 			sc->sc_ppsclear = 0;
1108 			break;
1109 
1110 		case PPS_CAPTUREBOTH:
1111 			sc->sc_ppsmask = MSR_DCD;
1112 			sc->sc_ppsassert = MSR_DCD;
1113 			sc->sc_ppsclear = 0;
1114 			break;
1115 
1116 		default:
1117 			error = EINVAL;
1118 			break;
1119 		}
1120 		break;
1121 	}
1122 
1123 	case PPS_IOC_GETCAP:
1124 		*(int*)data = ppscap;
1125 		break;
1126 
1127 	case PPS_IOC_FETCH: {
1128 		pps_info_t *pi;
1129 		pi = (pps_info_t *)data;
1130 		*pi = sc->ppsinfo;
1131 		break;
1132 	}
1133 
1134 	case TIOCDCDTIMESTAMP:	/* XXX old, overloaded  API used by xntpd v3 */
1135 		/*
1136 		 * Some GPS clocks models use the falling rather than
1137 		 * rising edge as the on-the-second signal.
1138 		 * The old API has no way to specify PPS polarity.
1139 		 */
1140 		sc->sc_ppsmask = MSR_DCD;
1141 #ifndef PPS_TRAILING_EDGE
1142 		sc->sc_ppsassert = MSR_DCD;
1143 		sc->sc_ppsclear = -1;
1144 		TIMESPEC_TO_TIMEVAL((struct timeval *)data,
1145 		    &sc->ppsinfo.assert_timestamp);
1146 #else
1147 		sc->sc_ppsassert = -1
1148 		sc->sc_ppsclear = 0;
1149 		TIMESPEC_TO_TIMEVAL((struct timeval *)data,
1150 		    &sc->ppsinfo.clear_timestamp);
1151 #endif
1152 		break;
1153 
1154 	default:
1155 		error = EPASSTHROUGH;
1156 		break;
1157 	}
1158 
1159 	COM_UNLOCK(sc);
1160 	splx(s);
1161 
1162 #ifdef COM_DEBUG
1163 	if (com_debug)
1164 		comstatus(sc, "comioctl ");
1165 #endif
1166 
1167 	return (error);
1168 }
1169 
1170 integrate void
1171 com_schedrx(struct com_softc *sc)
1172 {
1173 
1174 	sc->sc_rx_ready = 1;
1175 
1176 	/* Wake up the poller. */
1177 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
1178 	softintr_schedule(sc->sc_si);
1179 #else
1180 #ifndef __NO_SOFT_SERIAL_INTERRUPT
1181 	setsoftserial();
1182 #else
1183 	if (!com_softintr_scheduled) {
1184 		com_softintr_scheduled = 1;
1185 		callout_reset(&comsoft_callout, 1, comsoft, NULL);
1186 	}
1187 #endif
1188 #endif
1189 }
1190 
1191 void
1192 com_break(struct com_softc *sc, int onoff)
1193 {
1194 
1195 	if (onoff)
1196 		SET(sc->sc_lcr, LCR_SBREAK);
1197 	else
1198 		CLR(sc->sc_lcr, LCR_SBREAK);
1199 
1200 	if (!sc->sc_heldchange) {
1201 		if (sc->sc_tx_busy) {
1202 			sc->sc_heldtbc = sc->sc_tbc;
1203 			sc->sc_tbc = 0;
1204 			sc->sc_heldchange = 1;
1205 		} else
1206 			com_loadchannelregs(sc);
1207 	}
1208 }
1209 
1210 void
1211 com_modem(struct com_softc *sc, int onoff)
1212 {
1213 
1214 	if (sc->sc_mcr_dtr == 0)
1215 		return;
1216 
1217 	if (onoff)
1218 		SET(sc->sc_mcr, sc->sc_mcr_dtr);
1219 	else
1220 		CLR(sc->sc_mcr, sc->sc_mcr_dtr);
1221 
1222 	if (!sc->sc_heldchange) {
1223 		if (sc->sc_tx_busy) {
1224 			sc->sc_heldtbc = sc->sc_tbc;
1225 			sc->sc_tbc = 0;
1226 			sc->sc_heldchange = 1;
1227 		} else
1228 			com_loadchannelregs(sc);
1229 	}
1230 }
1231 
1232 void
1233 tiocm_to_com(struct com_softc *sc, u_long how, int ttybits)
1234 {
1235 	u_char combits;
1236 
1237 	combits = 0;
1238 	if (ISSET(ttybits, TIOCM_DTR))
1239 		SET(combits, MCR_DTR);
1240 	if (ISSET(ttybits, TIOCM_RTS))
1241 		SET(combits, MCR_RTS);
1242 
1243 	switch (how) {
1244 	case TIOCMBIC:
1245 		CLR(sc->sc_mcr, combits);
1246 		break;
1247 
1248 	case TIOCMBIS:
1249 		SET(sc->sc_mcr, combits);
1250 		break;
1251 
1252 	case TIOCMSET:
1253 		CLR(sc->sc_mcr, MCR_DTR | MCR_RTS);
1254 		SET(sc->sc_mcr, combits);
1255 		break;
1256 	}
1257 
1258 	if (!sc->sc_heldchange) {
1259 		if (sc->sc_tx_busy) {
1260 			sc->sc_heldtbc = sc->sc_tbc;
1261 			sc->sc_tbc = 0;
1262 			sc->sc_heldchange = 1;
1263 		} else
1264 			com_loadchannelregs(sc);
1265 	}
1266 }
1267 
1268 int
1269 com_to_tiocm(struct com_softc *sc)
1270 {
1271 	u_char combits;
1272 	int ttybits = 0;
1273 
1274 	combits = sc->sc_mcr;
1275 	if (ISSET(combits, MCR_DTR))
1276 		SET(ttybits, TIOCM_DTR);
1277 	if (ISSET(combits, MCR_RTS))
1278 		SET(ttybits, TIOCM_RTS);
1279 
1280 	combits = sc->sc_msr;
1281 	if (ISSET(combits, MSR_DCD))
1282 		SET(ttybits, TIOCM_CD);
1283 	if (ISSET(combits, MSR_CTS))
1284 		SET(ttybits, TIOCM_CTS);
1285 	if (ISSET(combits, MSR_DSR))
1286 		SET(ttybits, TIOCM_DSR);
1287 	if (ISSET(combits, MSR_RI | MSR_TERI))
1288 		SET(ttybits, TIOCM_RI);
1289 
1290 	if (sc->sc_ier != 0)
1291 		SET(ttybits, TIOCM_LE);
1292 
1293 	return (ttybits);
1294 }
1295 
1296 static u_char
1297 cflag2lcr(tcflag_t cflag)
1298 {
1299 	u_char lcr = 0;
1300 
1301 	switch (ISSET(cflag, CSIZE)) {
1302 	case CS5:
1303 		SET(lcr, LCR_5BITS);
1304 		break;
1305 	case CS6:
1306 		SET(lcr, LCR_6BITS);
1307 		break;
1308 	case CS7:
1309 		SET(lcr, LCR_7BITS);
1310 		break;
1311 	case CS8:
1312 		SET(lcr, LCR_8BITS);
1313 		break;
1314 	}
1315 	if (ISSET(cflag, PARENB)) {
1316 		SET(lcr, LCR_PENAB);
1317 		if (!ISSET(cflag, PARODD))
1318 			SET(lcr, LCR_PEVEN);
1319 	}
1320 	if (ISSET(cflag, CSTOPB))
1321 		SET(lcr, LCR_STOPB);
1322 
1323 	return (lcr);
1324 }
1325 
1326 int
1327 comparam(struct tty *tp, struct termios *t)
1328 {
1329 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(tp->t_dev));
1330 	int ospeed;
1331 	u_char lcr;
1332 	int s;
1333 
1334 	if (COM_ISALIVE(sc) == 0)
1335 		return (EIO);
1336 
1337 #ifdef COM_HAYESP
1338 	if (ISSET(sc->sc_hwflags, COM_HW_HAYESP)) {
1339 		int prescaler, speed;
1340 
1341 		/*
1342 		 * Calculate UART clock prescaler.  It should be in
1343 		 * range of 0 .. 3.
1344 		 */
1345 		for (prescaler = 0, speed = t->c_ospeed; prescaler < 4;
1346 		    prescaler++, speed /= 2)
1347 			if ((ospeed = comspeed(speed, sc->sc_frequency)) > 0)
1348 				break;
1349 
1350 		if (prescaler == 4)
1351 			return (EINVAL);
1352 		sc->sc_prescaler = prescaler;
1353 	} else
1354 #endif
1355 	ospeed = comspeed(t->c_ospeed, sc->sc_frequency);
1356 
1357 	/* Check requested parameters. */
1358 	if (ospeed < 0)
1359 		return (EINVAL);
1360 	if (t->c_ispeed && t->c_ispeed != t->c_ospeed)
1361 		return (EINVAL);
1362 
1363 	/*
1364 	 * For the console, always force CLOCAL and !HUPCL, so that the port
1365 	 * is always active.
1366 	 */
1367 	if (ISSET(sc->sc_swflags, TIOCFLAG_SOFTCAR) ||
1368 	    ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
1369 		SET(t->c_cflag, CLOCAL);
1370 		CLR(t->c_cflag, HUPCL);
1371 	}
1372 
1373 	/*
1374 	 * If there were no changes, don't do anything.  This avoids dropping
1375 	 * input and improves performance when all we did was frob things like
1376 	 * VMIN and VTIME.
1377 	 */
1378 	if (tp->t_ospeed == t->c_ospeed &&
1379 	    tp->t_cflag == t->c_cflag)
1380 		return (0);
1381 
1382 	lcr = ISSET(sc->sc_lcr, LCR_SBREAK) | cflag2lcr(t->c_cflag);
1383 
1384 	s = splserial();
1385 	COM_LOCK(sc);
1386 
1387 	sc->sc_lcr = lcr;
1388 
1389 	/*
1390 	 * If we're not in a mode that assumes a connection is present, then
1391 	 * ignore carrier changes.
1392 	 */
1393 	if (ISSET(t->c_cflag, CLOCAL | MDMBUF))
1394 		sc->sc_msr_dcd = 0;
1395 	else
1396 		sc->sc_msr_dcd = MSR_DCD;
1397 	/*
1398 	 * Set the flow control pins depending on the current flow control
1399 	 * mode.
1400 	 */
1401 	if (ISSET(t->c_cflag, CRTSCTS)) {
1402 		sc->sc_mcr_dtr = MCR_DTR;
1403 		sc->sc_mcr_rts = MCR_RTS;
1404 		sc->sc_msr_cts = MSR_CTS;
1405 		sc->sc_efr = EFR_AUTORTS | EFR_AUTOCTS;
1406 	} else if (ISSET(t->c_cflag, MDMBUF)) {
1407 		/*
1408 		 * For DTR/DCD flow control, make sure we don't toggle DTR for
1409 		 * carrier detection.
1410 		 */
1411 		sc->sc_mcr_dtr = 0;
1412 		sc->sc_mcr_rts = MCR_DTR;
1413 		sc->sc_msr_cts = MSR_DCD;
1414 		sc->sc_efr = 0;
1415 	} else {
1416 		/*
1417 		 * If no flow control, then always set RTS.  This will make
1418 		 * the other side happy if it mistakenly thinks we're doing
1419 		 * RTS/CTS flow control.
1420 		 */
1421 		sc->sc_mcr_dtr = MCR_DTR | MCR_RTS;
1422 		sc->sc_mcr_rts = 0;
1423 		sc->sc_msr_cts = 0;
1424 		sc->sc_efr = 0;
1425 		if (ISSET(sc->sc_mcr, MCR_DTR))
1426 			SET(sc->sc_mcr, MCR_RTS);
1427 		else
1428 			CLR(sc->sc_mcr, MCR_RTS);
1429 	}
1430 	sc->sc_msr_mask = sc->sc_msr_cts | sc->sc_msr_dcd;
1431 
1432 #if 0
1433 	if (ospeed == 0)
1434 		CLR(sc->sc_mcr, sc->sc_mcr_dtr);
1435 	else
1436 		SET(sc->sc_mcr, sc->sc_mcr_dtr);
1437 #endif
1438 
1439 	sc->sc_dlbl = ospeed;
1440 	sc->sc_dlbh = ospeed >> 8;
1441 
1442 	/*
1443 	 * Set the FIFO threshold based on the receive speed.
1444 	 *
1445 	 *  * If it's a low speed, it's probably a mouse or some other
1446 	 *    interactive device, so set the threshold low.
1447 	 *  * If it's a high speed, trim the trigger level down to prevent
1448 	 *    overflows.
1449 	 *  * Otherwise set it a bit higher.
1450 	 */
1451 	if (ISSET(sc->sc_hwflags, COM_HW_HAYESP))
1452 		sc->sc_fifo = FIFO_DMA_MODE | FIFO_ENABLE | FIFO_TRIGGER_8;
1453 	else if (ISSET(sc->sc_hwflags, COM_HW_FIFO))
1454 		sc->sc_fifo = FIFO_ENABLE |
1455 		    (t->c_ospeed <= 1200 ? FIFO_TRIGGER_1 :
1456 		     t->c_ospeed <= 38400 ? FIFO_TRIGGER_8 : FIFO_TRIGGER_4);
1457 	else
1458 		sc->sc_fifo = 0;
1459 
1460 	/* And copy to tty. */
1461 	tp->t_ispeed = 0;
1462 	tp->t_ospeed = t->c_ospeed;
1463 	tp->t_cflag = t->c_cflag;
1464 
1465 	if (!sc->sc_heldchange) {
1466 		if (sc->sc_tx_busy) {
1467 			sc->sc_heldtbc = sc->sc_tbc;
1468 			sc->sc_tbc = 0;
1469 			sc->sc_heldchange = 1;
1470 		} else
1471 			com_loadchannelregs(sc);
1472 	}
1473 
1474 	if (!ISSET(t->c_cflag, CHWFLOW)) {
1475 		/* Disable the high water mark. */
1476 		sc->sc_r_hiwat = 0;
1477 		sc->sc_r_lowat = 0;
1478 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
1479 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1480 			com_schedrx(sc);
1481 		}
1482 		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED)) {
1483 			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED);
1484 			com_hwiflow(sc);
1485 		}
1486 	} else {
1487 		sc->sc_r_hiwat = com_rbuf_hiwat;
1488 		sc->sc_r_lowat = com_rbuf_lowat;
1489 	}
1490 
1491 	COM_UNLOCK(sc);
1492 	splx(s);
1493 
1494 	/*
1495 	 * Update the tty layer's idea of the carrier bit, in case we changed
1496 	 * CLOCAL or MDMBUF.  We don't hang up here; we only do that by
1497 	 * explicit request.
1498 	 */
1499 	(void) (*tp->t_linesw->l_modem)(tp, ISSET(sc->sc_msr, MSR_DCD));
1500 
1501 #ifdef COM_DEBUG
1502 	if (com_debug)
1503 		comstatus(sc, "comparam ");
1504 #endif
1505 
1506 	if (!ISSET(t->c_cflag, CHWFLOW)) {
1507 		if (sc->sc_tx_stopped) {
1508 			sc->sc_tx_stopped = 0;
1509 			comstart(tp);
1510 		}
1511 	}
1512 
1513 	return (0);
1514 }
1515 
1516 void
1517 com_iflush(struct com_softc *sc)
1518 {
1519 	bus_space_tag_t iot = sc->sc_iot;
1520 	bus_space_handle_t ioh = sc->sc_ioh;
1521 #ifdef DIAGNOSTIC
1522 	int reg;
1523 #endif
1524 	int timo;
1525 
1526 #ifdef DIAGNOSTIC
1527 	reg = 0xffff;
1528 #endif
1529 	timo = 50000;
1530 	/* flush any pending I/O */
1531 	while (ISSET(bus_space_read_1(iot, ioh, com_lsr), LSR_RXRDY)
1532 	    && --timo)
1533 #ifdef DIAGNOSTIC
1534 		reg =
1535 #else
1536 		    (void)
1537 #endif
1538 		    bus_space_read_1(iot, ioh, com_data);
1539 #ifdef DIAGNOSTIC
1540 	if (!timo)
1541 		printf("%s: com_iflush timeout %02x\n", sc->sc_dev.dv_xname,
1542 		       reg);
1543 #endif
1544 }
1545 
1546 void
1547 com_loadchannelregs(struct com_softc *sc)
1548 {
1549 	bus_space_tag_t iot = sc->sc_iot;
1550 	bus_space_handle_t ioh = sc->sc_ioh;
1551 
1552 	/* XXXXX necessary? */
1553 	com_iflush(sc);
1554 
1555 	bus_space_write_1(iot, ioh, com_ier, 0);
1556 
1557 	if (ISSET(sc->sc_hwflags, COM_HW_FLOW)) {
1558 		bus_space_write_1(iot, ioh, com_lcr, LCR_EERS);
1559 		bus_space_write_1(iot, ioh, com_efr, sc->sc_efr);
1560 	}
1561 	bus_space_write_1(iot, ioh, com_lcr, sc->sc_lcr | LCR_DLAB);
1562 	bus_space_write_1(iot, ioh, com_dlbl, sc->sc_dlbl);
1563 	bus_space_write_1(iot, ioh, com_dlbh, sc->sc_dlbh);
1564 	bus_space_write_1(iot, ioh, com_lcr, sc->sc_lcr);
1565 	bus_space_write_1(iot, ioh, com_mcr, sc->sc_mcr_active = sc->sc_mcr);
1566 	bus_space_write_1(iot, ioh, com_fifo, sc->sc_fifo);
1567 #ifdef COM_HAYESP
1568 	if (ISSET(sc->sc_hwflags, COM_HW_HAYESP)) {
1569 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD1,
1570 		    HAYESP_SETPRESCALER);
1571 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
1572 		    sc->sc_prescaler);
1573 	}
1574 #endif
1575 
1576 	bus_space_write_1(iot, ioh, com_ier, sc->sc_ier);
1577 }
1578 
1579 int
1580 comhwiflow(struct tty *tp, int block)
1581 {
1582 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(tp->t_dev));
1583 	int s;
1584 
1585 	if (COM_ISALIVE(sc) == 0)
1586 		return (0);
1587 
1588 	if (sc->sc_mcr_rts == 0)
1589 		return (0);
1590 
1591 	s = splserial();
1592 	COM_LOCK(sc);
1593 
1594 	if (block) {
1595 		if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1596 			SET(sc->sc_rx_flags, RX_TTY_BLOCKED);
1597 			com_hwiflow(sc);
1598 		}
1599 	} else {
1600 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
1601 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1602 			com_schedrx(sc);
1603 		}
1604 		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1605 			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED);
1606 			com_hwiflow(sc);
1607 		}
1608 	}
1609 
1610 	COM_UNLOCK(sc);
1611 	splx(s);
1612 	return (1);
1613 }
1614 
1615 /*
1616  * (un)block input via hw flowcontrol
1617  */
1618 void
1619 com_hwiflow(struct com_softc *sc)
1620 {
1621 	bus_space_tag_t iot = sc->sc_iot;
1622 	bus_space_handle_t ioh = sc->sc_ioh;
1623 
1624 	if (sc->sc_mcr_rts == 0)
1625 		return;
1626 
1627 	if (ISSET(sc->sc_rx_flags, RX_ANY_BLOCK)) {
1628 		CLR(sc->sc_mcr, sc->sc_mcr_rts);
1629 		CLR(sc->sc_mcr_active, sc->sc_mcr_rts);
1630 	} else {
1631 		SET(sc->sc_mcr, sc->sc_mcr_rts);
1632 		SET(sc->sc_mcr_active, sc->sc_mcr_rts);
1633 	}
1634 	bus_space_write_1(iot, ioh, com_mcr, sc->sc_mcr_active);
1635 }
1636 
1637 
1638 void
1639 comstart(struct tty *tp)
1640 {
1641 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(tp->t_dev));
1642 	bus_space_tag_t iot = sc->sc_iot;
1643 	bus_space_handle_t ioh = sc->sc_ioh;
1644 	int s;
1645 
1646 	if (COM_ISALIVE(sc) == 0)
1647 		return;
1648 
1649 	s = spltty();
1650 	if (ISSET(tp->t_state, TS_BUSY | TS_TIMEOUT | TS_TTSTOP))
1651 		goto out;
1652 	if (sc->sc_tx_stopped)
1653 		goto out;
1654 
1655 	if (tp->t_outq.c_cc <= tp->t_lowat) {
1656 		if (ISSET(tp->t_state, TS_ASLEEP)) {
1657 			CLR(tp->t_state, TS_ASLEEP);
1658 			wakeup(&tp->t_outq);
1659 		}
1660 		selwakeup(&tp->t_wsel);
1661 		if (tp->t_outq.c_cc == 0)
1662 			goto out;
1663 	}
1664 
1665 	/* Grab the first contiguous region of buffer space. */
1666 	{
1667 		u_char *tba;
1668 		int tbc;
1669 
1670 		tba = tp->t_outq.c_cf;
1671 		tbc = ndqb(&tp->t_outq, 0);
1672 
1673 		(void)splserial();
1674 		COM_LOCK(sc);
1675 
1676 		sc->sc_tba = tba;
1677 		sc->sc_tbc = tbc;
1678 	}
1679 
1680 	SET(tp->t_state, TS_BUSY);
1681 	sc->sc_tx_busy = 1;
1682 
1683 	/* Enable transmit completion interrupts if necessary. */
1684 	if (!ISSET(sc->sc_ier, IER_ETXRDY)) {
1685 		SET(sc->sc_ier, IER_ETXRDY);
1686 		bus_space_write_1(iot, ioh, com_ier, sc->sc_ier);
1687 	}
1688 
1689 	/* Output the first chunk of the contiguous buffer. */
1690 	if (!ISSET(sc->sc_hwflags, COM_HW_NO_TXPRELOAD)) {
1691 		u_int n;
1692 
1693 		n = sc->sc_tbc;
1694 		if (n > sc->sc_fifolen)
1695 			n = sc->sc_fifolen;
1696 		bus_space_write_multi_1(iot, ioh, com_data, sc->sc_tba, n);
1697 		sc->sc_tbc -= n;
1698 		sc->sc_tba += n;
1699 	}
1700 	COM_UNLOCK(sc);
1701 out:
1702 	splx(s);
1703 	return;
1704 }
1705 
1706 /*
1707  * Stop output on a line.
1708  */
1709 void
1710 comstop(struct tty *tp, int flag)
1711 {
1712 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(tp->t_dev));
1713 	int s;
1714 
1715 	s = splserial();
1716 	COM_LOCK(sc);
1717 	if (ISSET(tp->t_state, TS_BUSY)) {
1718 		/* Stop transmitting at the next chunk. */
1719 		sc->sc_tbc = 0;
1720 		sc->sc_heldtbc = 0;
1721 		if (!ISSET(tp->t_state, TS_TTSTOP))
1722 			SET(tp->t_state, TS_FLUSH);
1723 	}
1724 	COM_UNLOCK(sc);
1725 	splx(s);
1726 }
1727 
1728 void
1729 comdiag(void *arg)
1730 {
1731 	struct com_softc *sc = arg;
1732 	int overflows, floods;
1733 	int s;
1734 
1735 	s = splserial();
1736 	COM_LOCK(sc);
1737 	overflows = sc->sc_overflows;
1738 	sc->sc_overflows = 0;
1739 	floods = sc->sc_floods;
1740 	sc->sc_floods = 0;
1741 	sc->sc_errors = 0;
1742 	COM_UNLOCK(sc);
1743 	splx(s);
1744 
1745 	log(LOG_WARNING, "%s: %d silo overflow%s, %d ibuf flood%s\n",
1746 	    sc->sc_dev.dv_xname,
1747 	    overflows, overflows == 1 ? "" : "s",
1748 	    floods, floods == 1 ? "" : "s");
1749 }
1750 
1751 integrate void
1752 com_rxsoft(struct com_softc *sc, struct tty *tp)
1753 {
1754 	int (*rint)(int, struct tty *) = tp->t_linesw->l_rint;
1755 	u_char *get, *end;
1756 	u_int cc, scc;
1757 	u_char lsr;
1758 	int code;
1759 	int s;
1760 
1761 	end = sc->sc_ebuf;
1762 	get = sc->sc_rbget;
1763 	scc = cc = com_rbuf_size - sc->sc_rbavail;
1764 
1765 	if (cc == com_rbuf_size) {
1766 		sc->sc_floods++;
1767 		if (sc->sc_errors++ == 0)
1768 			callout_reset(&sc->sc_diag_callout, 60 * hz,
1769 			    comdiag, sc);
1770 	}
1771 
1772 	while (cc) {
1773 		code = get[0];
1774 		lsr = get[1];
1775 		if (ISSET(lsr, LSR_OE | LSR_BI | LSR_FE | LSR_PE)) {
1776 			if (ISSET(lsr, LSR_OE)) {
1777 				sc->sc_overflows++;
1778 				if (sc->sc_errors++ == 0)
1779 					callout_reset(&sc->sc_diag_callout,
1780 					    60 * hz, comdiag, sc);
1781 			}
1782 			if (ISSET(lsr, LSR_BI | LSR_FE))
1783 				SET(code, TTY_FE);
1784 			if (ISSET(lsr, LSR_PE))
1785 				SET(code, TTY_PE);
1786 		}
1787 		if ((*rint)(code, tp) == -1) {
1788 			/*
1789 			 * The line discipline's buffer is out of space.
1790 			 */
1791 			if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1792 				/*
1793 				 * We're either not using flow control, or the
1794 				 * line discipline didn't tell us to block for
1795 				 * some reason.  Either way, we have no way to
1796 				 * know when there's more space available, so
1797 				 * just drop the rest of the data.
1798 				 */
1799 				get += cc << 1;
1800 				if (get >= end)
1801 					get -= com_rbuf_size << 1;
1802 				cc = 0;
1803 			} else {
1804 				/*
1805 				 * Don't schedule any more receive processing
1806 				 * until the line discipline tells us there's
1807 				 * space available (through comhwiflow()).
1808 				 * Leave the rest of the data in the input
1809 				 * buffer.
1810 				 */
1811 				SET(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1812 			}
1813 			break;
1814 		}
1815 		get += 2;
1816 		if (get >= end)
1817 			get = sc->sc_rbuf;
1818 		cc--;
1819 	}
1820 
1821 	if (cc != scc) {
1822 		sc->sc_rbget = get;
1823 		s = splserial();
1824 		COM_LOCK(sc);
1825 
1826 		cc = sc->sc_rbavail += scc - cc;
1827 		/* Buffers should be ok again, release possible block. */
1828 		if (cc >= sc->sc_r_lowat) {
1829 			if (ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
1830 				CLR(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
1831 				SET(sc->sc_ier, IER_ERXRDY);
1832 				bus_space_write_1(sc->sc_iot, sc->sc_ioh, com_ier, sc->sc_ier);
1833 			}
1834 			if (ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED)) {
1835 				CLR(sc->sc_rx_flags, RX_IBUF_BLOCKED);
1836 				com_hwiflow(sc);
1837 			}
1838 		}
1839 		COM_UNLOCK(sc);
1840 		splx(s);
1841 	}
1842 }
1843 
1844 integrate void
1845 com_txsoft(struct com_softc *sc, struct tty *tp)
1846 {
1847 
1848 	CLR(tp->t_state, TS_BUSY);
1849 	if (ISSET(tp->t_state, TS_FLUSH))
1850 		CLR(tp->t_state, TS_FLUSH);
1851 	else
1852 		ndflush(&tp->t_outq, (int)(sc->sc_tba - tp->t_outq.c_cf));
1853 	(*tp->t_linesw->l_start)(tp);
1854 }
1855 
1856 integrate void
1857 com_stsoft(struct com_softc *sc, struct tty *tp)
1858 {
1859 	u_char msr, delta;
1860 	int s;
1861 
1862 	s = splserial();
1863 	COM_LOCK(sc);
1864 	msr = sc->sc_msr;
1865 	delta = sc->sc_msr_delta;
1866 	sc->sc_msr_delta = 0;
1867 	COM_UNLOCK(sc);
1868 	splx(s);
1869 
1870 	if (ISSET(delta, sc->sc_msr_dcd)) {
1871 		/*
1872 		 * Inform the tty layer that carrier detect changed.
1873 		 */
1874 		(void) (*tp->t_linesw->l_modem)(tp, ISSET(msr, MSR_DCD));
1875 	}
1876 
1877 	if (ISSET(delta, sc->sc_msr_cts)) {
1878 		/* Block or unblock output according to flow control. */
1879 		if (ISSET(msr, sc->sc_msr_cts)) {
1880 			sc->sc_tx_stopped = 0;
1881 			(*tp->t_linesw->l_start)(tp);
1882 		} else {
1883 			sc->sc_tx_stopped = 1;
1884 		}
1885 	}
1886 
1887 #ifdef COM_DEBUG
1888 	if (com_debug)
1889 		comstatus(sc, "com_stsoft");
1890 #endif
1891 }
1892 
1893 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
1894 void
1895 comsoft(void *arg)
1896 {
1897 	struct com_softc *sc = arg;
1898 	struct tty *tp;
1899 
1900 	if (COM_ISALIVE(sc) == 0)
1901 		return;
1902 
1903 	{
1904 #else
1905 void
1906 #ifndef __NO_SOFT_SERIAL_INTERRUPT
1907 comsoft(void)
1908 #else
1909 comsoft(void *arg)
1910 #endif
1911 {
1912 	struct com_softc	*sc;
1913 	struct tty	*tp;
1914 	int	unit;
1915 #ifdef __NO_SOFT_SERIAL_INTERRUPT
1916 	int s;
1917 
1918 	s = splsoftserial();
1919 	com_softintr_scheduled = 0;
1920 #endif
1921 
1922 	for (unit = 0; unit < com_cd.cd_ndevs; unit++) {
1923 		sc = device_lookup(&com_cd, unit);
1924 		if (sc == NULL || !ISSET(sc->sc_hwflags, COM_HW_DEV_OK))
1925 			continue;
1926 
1927 		if (COM_ISALIVE(sc) == 0)
1928 			continue;
1929 
1930 		tp = sc->sc_tty;
1931 		if (tp == NULL)
1932 			continue;
1933 		if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0)
1934 			continue;
1935 #endif
1936 		tp = sc->sc_tty;
1937 
1938 		if (sc->sc_rx_ready) {
1939 			sc->sc_rx_ready = 0;
1940 			com_rxsoft(sc, tp);
1941 		}
1942 
1943 		if (sc->sc_st_check) {
1944 			sc->sc_st_check = 0;
1945 			com_stsoft(sc, tp);
1946 		}
1947 
1948 		if (sc->sc_tx_done) {
1949 			sc->sc_tx_done = 0;
1950 			com_txsoft(sc, tp);
1951 		}
1952 	}
1953 
1954 #ifndef __HAVE_GENERIC_SOFT_INTERRUPTS
1955 #ifdef __NO_SOFT_SERIAL_INTERRUPT
1956 	splx(s);
1957 #endif
1958 #endif
1959 }
1960 
1961 #ifdef __ALIGN_BRACKET_LEVEL_FOR_CTAGS
1962 	/* there has got to be a better way to do comsoft() */
1963 }}
1964 #endif
1965 
1966 int
1967 comintr(void *arg)
1968 {
1969 	struct com_softc *sc = arg;
1970 	bus_space_tag_t iot = sc->sc_iot;
1971 	bus_space_handle_t ioh = sc->sc_ioh;
1972 	u_char *put, *end;
1973 	u_int cc;
1974 	u_char lsr, iir;
1975 
1976 	if (COM_ISALIVE(sc) == 0)
1977 		return (0);
1978 
1979 	COM_LOCK(sc);
1980 	iir = bus_space_read_1(iot, ioh, com_iir);
1981 	if (ISSET(iir, IIR_NOPEND)) {
1982 		COM_UNLOCK(sc);
1983 		return (0);
1984 	}
1985 
1986 	end = sc->sc_ebuf;
1987 	put = sc->sc_rbput;
1988 	cc = sc->sc_rbavail;
1989 
1990 again:	do {
1991 		u_char	msr, delta;
1992 
1993 		lsr = bus_space_read_1(iot, ioh, com_lsr);
1994 		if (ISSET(lsr, LSR_BI)) {
1995 			int cn_trapped = 0;
1996 			cn_check_magic(sc->sc_tty->t_dev,
1997 				       CNC_BREAK, com_cnm_state);
1998 			if (cn_trapped)
1999 				continue;
2000 #if defined(KGDB)
2001 			if (ISSET(sc->sc_hwflags, COM_HW_KGDB)) {
2002 				kgdb_connect(1);
2003 				continue;
2004 			}
2005 #endif
2006 		}
2007 
2008 		if (ISSET(lsr, LSR_RCV_MASK) &&
2009 		    !ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
2010 			while (cc > 0) {
2011 				int cn_trapped = 0;
2012 				put[0] = bus_space_read_1(iot, ioh, com_data);
2013 				put[1] = lsr;
2014 				cn_check_magic(sc->sc_tty->t_dev,
2015 					       put[0], com_cnm_state);
2016 				if (cn_trapped) {
2017 					lsr = bus_space_read_1(iot, ioh, com_lsr);
2018 					if (!ISSET(lsr, LSR_RCV_MASK))
2019 						break;
2020 
2021 					continue;
2022 				}
2023 				put += 2;
2024 				if (put >= end)
2025 					put = sc->sc_rbuf;
2026 				cc--;
2027 
2028 				lsr = bus_space_read_1(iot, ioh, com_lsr);
2029 				if (!ISSET(lsr, LSR_RCV_MASK))
2030 					break;
2031 			}
2032 
2033 			/*
2034 			 * Current string of incoming characters ended because
2035 			 * no more data was available or we ran out of space.
2036 			 * Schedule a receive event if any data was received.
2037 			 * If we're out of space, turn off receive interrupts.
2038 			 */
2039 			sc->sc_rbput = put;
2040 			sc->sc_rbavail = cc;
2041 			if (!ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED))
2042 				sc->sc_rx_ready = 1;
2043 
2044 			/*
2045 			 * See if we are in danger of overflowing a buffer. If
2046 			 * so, use hardware flow control to ease the pressure.
2047 			 */
2048 			if (!ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED) &&
2049 			    cc < sc->sc_r_hiwat) {
2050 				SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
2051 				com_hwiflow(sc);
2052 			}
2053 
2054 			/*
2055 			 * If we're out of space, disable receive interrupts
2056 			 * until the queue has drained a bit.
2057 			 */
2058 			if (!cc) {
2059 				SET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
2060 				CLR(sc->sc_ier, IER_ERXRDY);
2061 				bus_space_write_1(iot, ioh, com_ier, sc->sc_ier);
2062 			}
2063 		} else {
2064 			if ((iir & IIR_IMASK) == IIR_RXRDY) {
2065 				bus_space_write_1(iot, ioh, com_ier, 0);
2066 				delay(10);
2067 				bus_space_write_1(iot, ioh, com_ier,sc->sc_ier);
2068 				continue;
2069 			}
2070 		}
2071 
2072 		msr = bus_space_read_1(iot, ioh, com_msr);
2073 		delta = msr ^ sc->sc_msr;
2074 		sc->sc_msr = msr;
2075 		/*
2076 		 * Pulse-per-second (PSS) signals on edge of DCD?
2077 		 * Process these even if line discipline is ignoring DCD.
2078 		 */
2079 		if (delta & sc->sc_ppsmask) {
2080 			struct timeval tv;
2081 		    	if ((msr & sc->sc_ppsmask) == sc->sc_ppsassert) {
2082 				/* XXX nanotime() */
2083 				microtime(&tv);
2084 				TIMEVAL_TO_TIMESPEC(&tv,
2085 				    &sc->ppsinfo.assert_timestamp);
2086 				if (sc->ppsparam.mode & PPS_OFFSETASSERT) {
2087 					timespecadd(&sc->ppsinfo.assert_timestamp,
2088 					    &sc->ppsparam.assert_offset,
2089 						    &sc->ppsinfo.assert_timestamp);
2090 				}
2091 
2092 #ifdef PPS_SYNC
2093 				if (sc->ppsparam.mode & PPS_HARDPPSONASSERT)
2094 					hardpps(&tv, tv.tv_usec);
2095 #endif
2096 				sc->ppsinfo.assert_sequence++;
2097 				sc->ppsinfo.current_mode = sc->ppsparam.mode;
2098 
2099 			} else if ((msr & sc->sc_ppsmask) == sc->sc_ppsclear) {
2100 				/* XXX nanotime() */
2101 				microtime(&tv);
2102 				TIMEVAL_TO_TIMESPEC(&tv,
2103 				    &sc->ppsinfo.clear_timestamp);
2104 				if (sc->ppsparam.mode & PPS_OFFSETCLEAR) {
2105 					timespecadd(&sc->ppsinfo.clear_timestamp,
2106 					    &sc->ppsparam.clear_offset,
2107 					    &sc->ppsinfo.clear_timestamp);
2108 				}
2109 
2110 #ifdef PPS_SYNC
2111 				if (sc->ppsparam.mode & PPS_HARDPPSONCLEAR)
2112 					hardpps(&tv, tv.tv_usec);
2113 #endif
2114 				sc->ppsinfo.clear_sequence++;
2115 				sc->ppsinfo.current_mode = sc->ppsparam.mode;
2116 			}
2117 		}
2118 
2119 		/*
2120 		 * Process normal status changes
2121 		 */
2122 		if (ISSET(delta, sc->sc_msr_mask)) {
2123 			SET(sc->sc_msr_delta, delta);
2124 
2125 			/*
2126 			 * Stop output immediately if we lose the output
2127 			 * flow control signal or carrier detect.
2128 			 */
2129 			if (ISSET(~msr, sc->sc_msr_mask)) {
2130 				sc->sc_tbc = 0;
2131 				sc->sc_heldtbc = 0;
2132 #ifdef COM_DEBUG
2133 				if (com_debug)
2134 					comstatus(sc, "comintr  ");
2135 #endif
2136 			}
2137 
2138 			sc->sc_st_check = 1;
2139 		}
2140 	} while (ISSET((iir = bus_space_read_1(iot, ioh, com_iir)), IIR_RXRDY)
2141 	    || ((iir & IIR_IMASK) == 0));
2142 
2143 	/*
2144 	 * Done handling any receive interrupts. See if data can be
2145 	 * transmitted as well. Schedule tx done event if no data left
2146 	 * and tty was marked busy.
2147 	 */
2148 	if (ISSET(lsr, LSR_TXRDY)) {
2149 		/*
2150 		 * If we've delayed a parameter change, do it now, and restart
2151 		 * output.
2152 		 */
2153 		if (sc->sc_heldchange) {
2154 			com_loadchannelregs(sc);
2155 			sc->sc_heldchange = 0;
2156 			sc->sc_tbc = sc->sc_heldtbc;
2157 			sc->sc_heldtbc = 0;
2158 		}
2159 
2160 		/* Output the next chunk of the contiguous buffer, if any. */
2161 		if (sc->sc_tbc > 0) {
2162 			u_int n;
2163 
2164 			n = sc->sc_tbc;
2165 			if (n > sc->sc_fifolen)
2166 				n = sc->sc_fifolen;
2167 			bus_space_write_multi_1(iot, ioh, com_data, sc->sc_tba, n);
2168 			sc->sc_tbc -= n;
2169 			sc->sc_tba += n;
2170 		} else {
2171 			/* Disable transmit completion interrupts if necessary. */
2172 			if (ISSET(sc->sc_ier, IER_ETXRDY)) {
2173 				CLR(sc->sc_ier, IER_ETXRDY);
2174 				bus_space_write_1(iot, ioh, com_ier, sc->sc_ier);
2175 			}
2176 			if (sc->sc_tx_busy) {
2177 				sc->sc_tx_busy = 0;
2178 				sc->sc_tx_done = 1;
2179 			}
2180 		}
2181 	}
2182 
2183 	if (!ISSET((iir = bus_space_read_1(iot, ioh, com_iir)), IIR_NOPEND))
2184 		goto again;
2185 
2186 	COM_UNLOCK(sc);
2187 
2188 	/* Wake up the poller. */
2189 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
2190 	softintr_schedule(sc->sc_si);
2191 #else
2192 #ifndef __NO_SOFT_SERIAL_INTERRUPT
2193 	setsoftserial();
2194 #else
2195 	if (!com_softintr_scheduled) {
2196 		com_softintr_scheduled = 1;
2197 		callout_reset(&comsoft_callout, 1, comsoft, NULL);
2198 	}
2199 #endif
2200 #endif
2201 
2202 #if NRND > 0 && defined(RND_COM)
2203 	rnd_add_uint32(&sc->rnd_source, iir | lsr);
2204 #endif
2205 
2206 	return (1);
2207 }
2208 
2209 /*
2210  * The following functions are polled getc and putc routines, shared
2211  * by the console and kgdb glue.
2212  *
2213  * The read-ahead code is so that you can detect pending in-band
2214  * cn_magic in polled mode while doing output rather than having to
2215  * wait until the kernel decides it needs input.
2216  */
2217 
2218 #define MAX_READAHEAD	20
2219 static int com_readahead[MAX_READAHEAD];
2220 static int com_readaheadcount = 0;
2221 
2222 int
2223 com_common_getc(dev_t dev, bus_space_tag_t iot, bus_space_handle_t ioh)
2224 {
2225 	int s = splserial();
2226 	u_char stat, c;
2227 
2228 	/* got a character from reading things earlier */
2229 	if (com_readaheadcount > 0) {
2230 		int i;
2231 
2232 		c = com_readahead[0];
2233 		for (i = 1; i < com_readaheadcount; i++) {
2234 			com_readahead[i-1] = com_readahead[i];
2235 		}
2236 		com_readaheadcount--;
2237 		splx(s);
2238 		return (c);
2239 	}
2240 
2241 	/* block until a character becomes available */
2242 	while (!ISSET(stat = bus_space_read_1(iot, ioh, com_lsr), LSR_RXRDY))
2243 		;
2244 
2245 	c = bus_space_read_1(iot, ioh, com_data);
2246 	stat = bus_space_read_1(iot, ioh, com_iir);
2247 	{
2248 		int cn_trapped = 0; /* unused */
2249 #ifdef DDB
2250 		extern int db_active;
2251 		if (!db_active)
2252 #endif
2253 			cn_check_magic(dev, c, com_cnm_state);
2254 	}
2255 	splx(s);
2256 	return (c);
2257 }
2258 
2259 void
2260 com_common_putc(dev_t dev, bus_space_tag_t iot, bus_space_handle_t ioh, int c)
2261 {
2262 	int s = splserial();
2263 	int timo;
2264 
2265 	int cin, stat;
2266 	if (com_readaheadcount < MAX_READAHEAD
2267 	     && ISSET(stat = bus_space_read_1(iot, ioh, com_lsr), LSR_RXRDY)) {
2268 		int cn_trapped = 0;
2269 		cin = bus_space_read_1(iot, ioh, com_data);
2270 		stat = bus_space_read_1(iot, ioh, com_iir);
2271 		cn_check_magic(dev, cin, com_cnm_state);
2272 		com_readahead[com_readaheadcount++] = cin;
2273 	}
2274 
2275 	/* wait for any pending transmission to finish */
2276 	timo = 150000;
2277 	while (!ISSET(bus_space_read_1(iot, ioh, com_lsr), LSR_TXRDY) && --timo)
2278 		continue;
2279 
2280 	bus_space_write_1(iot, ioh, com_data, c);
2281 	COM_BARRIER(iot, ioh, BR | BW);
2282 
2283 	/* wait for this transmission to complete */
2284 	timo = 1500000;
2285 	while (!ISSET(bus_space_read_1(iot, ioh, com_lsr), LSR_TXRDY) && --timo)
2286 		continue;
2287 
2288 	splx(s);
2289 }
2290 
2291 /*
2292  * Initialize UART for use as console or KGDB line.
2293  */
2294 int
2295 cominit(bus_space_tag_t iot, bus_addr_t iobase, int rate, int frequency,
2296     tcflag_t cflag, bus_space_handle_t *iohp)
2297 {
2298 	bus_space_handle_t ioh;
2299 
2300 	if (bus_space_map(iot, iobase, COM_NPORTS, 0, &ioh))
2301 		return (ENOMEM); /* ??? */
2302 
2303 	bus_space_write_1(iot, ioh, com_lcr, LCR_EERS);
2304 	bus_space_write_1(iot, ioh, com_efr, 0);
2305 	bus_space_write_1(iot, ioh, com_lcr, LCR_DLAB);
2306 	rate = comspeed(rate, frequency);
2307 	bus_space_write_1(iot, ioh, com_dlbl, rate);
2308 	bus_space_write_1(iot, ioh, com_dlbh, rate >> 8);
2309 	bus_space_write_1(iot, ioh, com_lcr, cflag2lcr(cflag));
2310 	bus_space_write_1(iot, ioh, com_mcr, MCR_DTR | MCR_RTS);
2311 	bus_space_write_1(iot, ioh, com_fifo,
2312 	    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_1);
2313 	bus_space_write_1(iot, ioh, com_ier, 0);
2314 
2315 	*iohp = ioh;
2316 	return (0);
2317 }
2318 
2319 /*
2320  * Following are all routines needed for COM to act as console
2321  */
2322 struct consdev comcons = {
2323 	NULL, NULL, comcngetc, comcnputc, comcnpollc, NULL,
2324 	NODEV, CN_NORMAL
2325 };
2326 
2327 
2328 int
2329 comcnattach(bus_space_tag_t iot, bus_addr_t iobase, int rate, int frequency,
2330     tcflag_t cflag)
2331 {
2332 	int res;
2333 
2334 	res = cominit(iot, iobase, rate, frequency, cflag, &comconsioh);
2335 	if (res)
2336 		return (res);
2337 
2338 	cn_tab = &comcons;
2339 	cn_init_magic(&com_cnm_state);
2340 	cn_set_magic("\047\001"); /* default magic is BREAK */
2341 
2342 	comconstag = iot;
2343 	comconsaddr = iobase;
2344 	comconsrate = rate;
2345 	comconscflag = cflag;
2346 
2347 	return (0);
2348 }
2349 
2350 int
2351 comcngetc(dev_t dev)
2352 {
2353 
2354 	return (com_common_getc(dev, comconstag, comconsioh));
2355 }
2356 
2357 /*
2358  * Console kernel output character routine.
2359  */
2360 void
2361 comcnputc(dev_t dev, int c)
2362 {
2363 
2364 	com_common_putc(dev, comconstag, comconsioh, c);
2365 }
2366 
2367 void
2368 comcnpollc(dev_t dev, int on)
2369 {
2370 
2371 }
2372 
2373 #ifdef KGDB
2374 int
2375 com_kgdb_attach(bus_space_tag_t iot, bus_addr_t iobase, int rate,
2376     int frequency, tcflag_t cflag)
2377 {
2378 	int res;
2379 
2380 	if (iot == comconstag && iobase == comconsaddr)
2381 		return (EBUSY); /* cannot share with console */
2382 
2383 	res = cominit(iot, iobase, rate, frequency, cflag, &com_kgdb_ioh);
2384 	if (res)
2385 		return (res);
2386 
2387 	/*
2388 	 * XXXfvdl this shouldn't be needed, but the cn_magic goo
2389 	 * expects this to be initialized
2390 	 */
2391 	cn_init_magic(&com_cnm_state);
2392 	cn_set_magic("\047\001");
2393 
2394 	kgdb_attach(com_kgdb_getc, com_kgdb_putc, NULL);
2395 	kgdb_dev = 123; /* unneeded, only to satisfy some tests */
2396 
2397 	com_kgdb_iot = iot;
2398 	com_kgdb_addr = iobase;
2399 
2400 	return (0);
2401 }
2402 
2403 /* ARGSUSED */
2404 int
2405 com_kgdb_getc(void *arg)
2406 {
2407 
2408 	return (com_common_getc(NODEV, com_kgdb_iot, com_kgdb_ioh));
2409 }
2410 
2411 /* ARGSUSED */
2412 void
2413 com_kgdb_putc(void *arg, int c)
2414 {
2415 
2416 	com_common_putc(NODEV, com_kgdb_iot, com_kgdb_ioh, c);
2417 }
2418 #endif /* KGDB */
2419 
2420 /* helper function to identify the com ports used by
2421  console or KGDB (and not yet autoconf attached) */
2422 int
2423 com_is_console(bus_space_tag_t iot, bus_addr_t iobase, bus_space_handle_t *ioh)
2424 {
2425 	bus_space_handle_t help;
2426 
2427 	if (!comconsattached &&
2428 	    iot == comconstag && iobase == comconsaddr)
2429 		help = comconsioh;
2430 #ifdef KGDB
2431 	else if (!com_kgdb_attached &&
2432 	    iot == com_kgdb_iot && iobase == com_kgdb_addr)
2433 		help = com_kgdb_ioh;
2434 #endif
2435 	else
2436 		return (0);
2437 
2438 	if (ioh)
2439 		*ioh = help;
2440 	return (1);
2441 }
2442