xref: /netbsd-src/sys/dev/ic/com.c (revision 3b01aba77a7a698587faaae455bbfe740923c1f5)
1 /*	$NetBSD: com.c,v 1.186 2001/06/20 03:07:25 uwe 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 "opt_com.h"
80 #include "opt_ddb.h"
81 #include "opt_ddbparam.h"
82 #include "opt_kgdb.h"
83 
84 #include "rnd.h"
85 #if NRND > 0 && defined(RND_COM)
86 #include <sys/rnd.h>
87 #endif
88 
89 /*
90  * Override cnmagic(9) macro before including <sys/systm.h>.
91  * We need to know if cn_check_magic triggered debugger, so set a flag.
92  * Callers of cn_check_magic must declare int cn_trapped = 0;
93  * XXX: this is *ugly*!
94  */
95 #define cn_trap()				\
96 	do {					\
97 		console_debugger();		\
98 		cn_trapped = 1;			\
99 	} while (/* CONSTCOND */ 0)
100 
101 #include <sys/param.h>
102 #include <sys/systm.h>
103 #include <sys/ioctl.h>
104 #include <sys/select.h>
105 #include <sys/tty.h>
106 #include <sys/proc.h>
107 #include <sys/user.h>
108 #include <sys/conf.h>
109 #include <sys/file.h>
110 #include <sys/uio.h>
111 #include <sys/kernel.h>
112 #include <sys/syslog.h>
113 #include <sys/types.h>
114 #include <sys/device.h>
115 #include <sys/malloc.h>
116 #include <sys/timepps.h>
117 #include <sys/vnode.h>
118 
119 #include <machine/intr.h>
120 #include <machine/bus.h>
121 
122 #include <dev/ic/comreg.h>
123 #include <dev/ic/comvar.h>
124 #include <dev/ic/ns16550reg.h>
125 #include <dev/ic/st16650reg.h>
126 #ifdef COM_HAYESP
127 #include <dev/ic/hayespreg.h>
128 #endif
129 #define	com_lcr	com_cfcr
130 #include <dev/cons.h>
131 
132 #include "com.h"
133 
134 #ifdef COM_HAYESP
135 int comprobeHAYESP __P((bus_space_handle_t hayespioh, struct com_softc *sc));
136 #endif
137 
138 static void com_enable_debugport __P((struct com_softc *));
139 
140 void	com_config	__P((struct com_softc *));
141 void	com_shutdown	__P((struct com_softc *));
142 int	comspeed	__P((long, long));
143 static	u_char	cflag2lcr __P((tcflag_t));
144 int	comparam	__P((struct tty *, struct termios *));
145 void	comstart	__P((struct tty *));
146 void	comstop		__P((struct tty *, int));
147 int	comhwiflow	__P((struct tty *, int));
148 
149 void	com_loadchannelregs __P((struct com_softc *));
150 void	com_hwiflow	__P((struct com_softc *));
151 void	com_break	__P((struct com_softc *, int));
152 void	com_modem	__P((struct com_softc *, int));
153 void	tiocm_to_com	__P((struct com_softc *, u_long, int));
154 int	com_to_tiocm	__P((struct com_softc *));
155 void	com_iflush	__P((struct com_softc *));
156 
157 int	com_common_getc	__P((dev_t, bus_space_tag_t, bus_space_handle_t));
158 void	com_common_putc	__P((dev_t, bus_space_tag_t, bus_space_handle_t, int));
159 
160 /* XXX: These belong elsewhere */
161 cdev_decl(com);
162 bdev_decl(com);
163 
164 int	comcngetc	__P((dev_t));
165 void	comcnputc	__P((dev_t, int));
166 void	comcnpollc	__P((dev_t, int));
167 
168 #define	integrate	static inline
169 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
170 void 	comsoft		__P((void *));
171 #else
172 #ifndef __NO_SOFT_SERIAL_INTERRUPT
173 void 	comsoft		__P((void));
174 #else
175 void 	comsoft		__P((void *));
176 struct callout comsoft_callout = CALLOUT_INITIALIZER;
177 #endif
178 #endif
179 integrate void com_rxsoft	__P((struct com_softc *, struct tty *));
180 integrate void com_txsoft	__P((struct com_softc *, struct tty *));
181 integrate void com_stsoft	__P((struct com_softc *, struct tty *));
182 integrate void com_schedrx	__P((struct com_softc *));
183 void	comdiag		__P((void *));
184 
185 extern struct cfdriver com_cd;
186 
187 /*
188  * Make this an option variable one can patch.
189  * But be warned:  this must be a power of 2!
190  */
191 u_int com_rbuf_size = COM_RING_SIZE;
192 
193 /* Stop input when 3/4 of the ring is full; restart when only 1/4 is full. */
194 u_int com_rbuf_hiwat = (COM_RING_SIZE * 1) / 4;
195 u_int com_rbuf_lowat = (COM_RING_SIZE * 3) / 4;
196 
197 static bus_addr_t	comconsaddr;
198 static bus_space_tag_t comconstag;
199 static bus_space_handle_t comconsioh;
200 static int	comconsattached;
201 static int comconsrate;
202 static tcflag_t comconscflag;
203 static struct cnm_state com_cnm_state;
204 
205 static int ppscap =
206 	PPS_TSFMT_TSPEC |
207 	PPS_CAPTUREASSERT |
208 	PPS_CAPTURECLEAR |
209 #ifdef  PPS_SYNC
210 	PPS_HARDPPSONASSERT | PPS_HARDPPSONCLEAR |
211 #endif	/* PPS_SYNC */
212 	PPS_OFFSETASSERT | PPS_OFFSETCLEAR;
213 
214 #ifndef __HAVE_GENERIC_SOFT_INTERRUPTS
215 #ifdef __NO_SOFT_SERIAL_INTERRUPT
216 volatile int	com_softintr_scheduled;
217 #endif
218 #endif
219 
220 #ifdef KGDB
221 #include <sys/kgdb.h>
222 
223 static bus_addr_t com_kgdb_addr;
224 static bus_space_tag_t com_kgdb_iot;
225 static bus_space_handle_t com_kgdb_ioh;
226 static int com_kgdb_attached;
227 
228 int	com_kgdb_getc __P((void *));
229 void	com_kgdb_putc __P((void *, int));
230 #endif /* KGDB */
231 
232 #define	COMUNIT_MASK	0x7ffff
233 #define	COMDIALOUT_MASK	0x80000
234 
235 #define	COMUNIT(x)	(minor(x) & COMUNIT_MASK)
236 #define	COMDIALOUT(x)	(minor(x) & COMDIALOUT_MASK)
237 
238 #define	COM_ISALIVE(sc)	((sc)->enabled != 0 && \
239 			 ISSET((sc)->sc_dev.dv_flags, DVF_ACTIVE))
240 
241 #define	BR	BUS_SPACE_BARRIER_READ
242 #define	BW	BUS_SPACE_BARRIER_WRITE
243 #define COM_BARRIER(t, h, f) bus_space_barrier((t), (h), 0, COM_NPORTS, (f))
244 
245 #if (defined(MULTIPROCESSOR) || defined(LOCKDEBUG)) && defined(COM_MPLOCK)
246 
247 #define COM_LOCK(sc) simple_lock(&(sc)->sc_lock)
248 #define COM_UNLOCK(sc) simple_unlock(&(sc)->sc_lock)
249 
250 #else
251 
252 #define COM_LOCK(sc)
253 #define COM_UNLOCK(sc)
254 
255 #endif
256 
257 int
258 comspeed(speed, frequency)
259 	long speed, frequency;
260 {
261 #define	divrnd(n, q)	(((n)*2/(q)+1)/2)	/* divide and round off */
262 
263 	int x, err;
264 
265 #if 0
266 	if (speed == 0)
267 		return (0);
268 #endif
269 	if (speed <= 0)
270 		return (-1);
271 	x = divrnd(frequency / 16, speed);
272 	if (x <= 0)
273 		return (-1);
274 	err = divrnd(((quad_t)frequency) * 1000 / 16, speed * x) - 1000;
275 	if (err < 0)
276 		err = -err;
277 	if (err > COM_TOLERANCE)
278 		return (-1);
279 	return (x);
280 
281 #undef	divrnd
282 }
283 
284 #ifdef COM_DEBUG
285 int	com_debug = 0;
286 
287 void comstatus __P((struct com_softc *, char *));
288 void
289 comstatus(sc, str)
290 	struct com_softc *sc;
291 	char *str;
292 {
293 	struct tty *tp = sc->sc_tty;
294 
295 	printf("%s: %s %sclocal  %sdcd %sts_carr_on %sdtr %stx_stopped\n",
296 	    sc->sc_dev.dv_xname, str,
297 	    ISSET(tp->t_cflag, CLOCAL) ? "+" : "-",
298 	    ISSET(sc->sc_msr, MSR_DCD) ? "+" : "-",
299 	    ISSET(tp->t_state, TS_CARR_ON) ? "+" : "-",
300 	    ISSET(sc->sc_mcr, MCR_DTR) ? "+" : "-",
301 	    sc->sc_tx_stopped ? "+" : "-");
302 
303 	printf("%s: %s %scrtscts %scts %sts_ttstop  %srts %xrx_flags\n",
304 	    sc->sc_dev.dv_xname, str,
305 	    ISSET(tp->t_cflag, CRTSCTS) ? "+" : "-",
306 	    ISSET(sc->sc_msr, MSR_CTS) ? "+" : "-",
307 	    ISSET(tp->t_state, TS_TTSTOP) ? "+" : "-",
308 	    ISSET(sc->sc_mcr, MCR_RTS) ? "+" : "-",
309 	    sc->sc_rx_flags);
310 }
311 #endif
312 
313 int
314 comprobe1(iot, ioh)
315 	bus_space_tag_t iot;
316 	bus_space_handle_t ioh;
317 {
318 
319 	/* force access to id reg */
320 	bus_space_write_1(iot, ioh, com_lcr, LCR_8BITS);
321 	bus_space_write_1(iot, ioh, com_iir, 0);
322 	if ((bus_space_read_1(iot, ioh, com_lcr) != LCR_8BITS) ||
323 	    (bus_space_read_1(iot, ioh, com_iir) & 0x38))
324 		return (0);
325 
326 	return (1);
327 }
328 
329 #ifdef COM_HAYESP
330 int
331 comprobeHAYESP(hayespioh, sc)
332 	bus_space_handle_t hayespioh;
333 	struct com_softc *sc;
334 {
335 	char	val, dips;
336 	int	combaselist[] = { 0x3f8, 0x2f8, 0x3e8, 0x2e8 };
337 	bus_space_tag_t iot = sc->sc_iot;
338 
339 	/*
340 	 * Hayes ESP cards have two iobases.  One is for compatibility with
341 	 * 16550 serial chips, and at the same ISA PC base addresses.  The
342 	 * other is for ESP-specific enhanced features, and lies at a
343 	 * different addressing range entirely (0x140, 0x180, 0x280, or 0x300).
344 	 */
345 
346 	/* Test for ESP signature */
347 	if ((bus_space_read_1(iot, hayespioh, 0) & 0xf3) == 0)
348 		return (0);
349 
350 	/*
351 	 * ESP is present at ESP enhanced base address; unknown com port
352 	 */
353 
354 	/* Get the dip-switch configurations */
355 	bus_space_write_1(iot, hayespioh, HAYESP_CMD1, HAYESP_GETDIPS);
356 	dips = bus_space_read_1(iot, hayespioh, HAYESP_STATUS1);
357 
358 	/* Determine which com port this ESP card services: bits 0,1 of  */
359 	/*  dips is the port # (0-3); combaselist[val] is the com_iobase */
360 	if (sc->sc_iobase != combaselist[dips & 0x03])
361 		return (0);
362 
363 	printf(": ESP");
364 
365  	/* Check ESP Self Test bits. */
366 	/* Check for ESP version 2.0: bits 4,5,6 == 010 */
367 	bus_space_write_1(iot, hayespioh, HAYESP_CMD1, HAYESP_GETTEST);
368 	val = bus_space_read_1(iot, hayespioh, HAYESP_STATUS1); /* Clear reg1 */
369 	val = bus_space_read_1(iot, hayespioh, HAYESP_STATUS2);
370 	if ((val & 0x70) < 0x20) {
371 		printf("-old (%o)", val & 0x70);
372 		/* we do not support the necessary features */
373 		return (0);
374 	}
375 
376 	/* Check for ability to emulate 16550: bit 8 == 1 */
377 	if ((dips & 0x80) == 0) {
378 		printf(" slave");
379 		/* XXX Does slave really mean no 16550 support?? */
380 		return (0);
381 	}
382 
383 	/*
384 	 * If we made it this far, we are a full-featured ESP v2.0 (or
385 	 * better), at the correct com port address.
386 	 */
387 
388 	SET(sc->sc_hwflags, COM_HW_HAYESP);
389 	printf(", 1024 byte fifo\n");
390 	return (1);
391 }
392 #endif
393 
394 static void
395 com_enable_debugport(sc)
396 	struct com_softc *sc;
397 {
398 	int s;
399 
400 	/* Turn on line break interrupt, set carrier. */
401 	s = splserial();
402 	COM_LOCK(sc);
403 	sc->sc_ier = IER_ERXRDY;
404 	bus_space_write_1(sc->sc_iot, sc->sc_ioh, com_ier, sc->sc_ier);
405 	SET(sc->sc_mcr, MCR_DTR | MCR_RTS);
406 	bus_space_write_1(sc->sc_iot, sc->sc_ioh, com_mcr, sc->sc_mcr);
407 	COM_UNLOCK(sc);
408 	splx(s);
409 }
410 
411 void
412 com_attach_subr(sc)
413 	struct com_softc *sc;
414 {
415 	bus_addr_t iobase = sc->sc_iobase;
416 	bus_space_tag_t iot = sc->sc_iot;
417 	bus_space_handle_t ioh = sc->sc_ioh;
418 	struct tty *tp;
419 #ifdef COM16650
420 	u_int8_t lcr;
421 #endif
422 #ifdef COM_HAYESP
423 	int	hayesp_ports[] = { 0x140, 0x180, 0x280, 0x300, 0 };
424 	int	*hayespp;
425 #endif
426 
427 	callout_init(&sc->sc_diag_callout);
428 #if (defined(MULTIPROCESSOR) || defined(LOCKDEBUG)) && defined(COM_MPLOCK)
429 	simple_lock_init(&sc->sc_lock);
430 #endif
431 
432 	/* Disable interrupts before configuring the device. */
433 	sc->sc_ier = 0;
434 	bus_space_write_1(iot, ioh, com_ier, sc->sc_ier);
435 
436 	if (iot == comconstag && iobase == comconsaddr) {
437 		comconsattached = 1;
438 
439 		/* Make sure the console is always "hardwired". */
440 		delay(1000);			/* wait for output to finish */
441 		SET(sc->sc_hwflags, COM_HW_CONSOLE);
442 		SET(sc->sc_swflags, TIOCFLAG_SOFTCAR);
443 	}
444 
445 #ifdef COM_HAYESP
446 	/* Look for a Hayes ESP board. */
447 	for (hayespp = hayesp_ports; *hayespp != 0; hayespp++) {
448 		bus_space_handle_t hayespioh;
449 
450 #define	HAYESP_NPORTS	8			/* XXX XXX XXX ??? ??? ??? */
451 		if (bus_space_map(iot, *hayespp, HAYESP_NPORTS, 0, &hayespioh))
452 			continue;
453 		if (comprobeHAYESP(hayespioh, sc)) {
454 			sc->sc_hayespioh = hayespioh;
455 			sc->sc_fifolen = 1024;
456 
457 			break;
458 		}
459 		bus_space_unmap(iot, hayespioh, HAYESP_NPORTS);
460 	}
461 	/* No ESP; look for other things. */
462 	if (!ISSET(sc->sc_hwflags, COM_HW_HAYESP)) {
463 #endif
464 	sc->sc_fifolen = 1;
465 	/* look for a NS 16550AF UART with FIFOs */
466 	bus_space_write_1(iot, ioh, com_fifo,
467 	    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_14);
468 	delay(100);
469 	if (ISSET(bus_space_read_1(iot, ioh, com_iir), IIR_FIFO_MASK)
470 	    == IIR_FIFO_MASK)
471 		if (ISSET(bus_space_read_1(iot, ioh, com_fifo), FIFO_TRIGGER_14)
472 		    == FIFO_TRIGGER_14) {
473 			SET(sc->sc_hwflags, COM_HW_FIFO);
474 
475 #ifdef COM16650
476 			/*
477 			 * IIR changes into the EFR if LCR is set to LCR_EERS
478 			 * on 16650s. We also know IIR != 0 at this point.
479 			 * Write 0 into the EFR, and read it. If the result
480 			 * is 0, we have a 16650.
481 			 *
482 			 * Older 16650s were broken; the test to detect them
483 			 * is taken from the Linux driver. Apparently
484 			 * setting DLAB enable gives access to the EFR on
485 			 * these chips.
486 			 */
487 			lcr = bus_space_read_1(iot, ioh, com_lcr);
488 			bus_space_write_1(iot, ioh, com_lcr, LCR_EERS);
489 			bus_space_write_1(iot, ioh, com_efr, 0);
490 			if (bus_space_read_1(iot, ioh, com_efr) == 0) {
491 				bus_space_write_1(iot, ioh, com_lcr,
492 				    lcr | LCR_DLAB);
493 				if (bus_space_read_1(iot, ioh, com_efr) == 0) {
494 					CLR(sc->sc_hwflags, COM_HW_FIFO);
495 					sc->sc_fifolen = 0;
496 				} else {
497 					SET(sc->sc_hwflags, COM_HW_FLOW);
498 					sc->sc_fifolen = 32;
499 				}
500 			} else
501 #endif
502 				sc->sc_fifolen = 16;
503 
504 #ifdef COM16650
505 			bus_space_write_1(iot, ioh, com_lcr, lcr);
506 			if (sc->sc_fifolen == 0)
507 				printf(": st16650, broken fifo\n");
508 			else if (sc->sc_fifolen == 32)
509 				printf(": st16650a, working fifo\n");
510 			else
511 #endif
512 				printf(": ns16550a, working fifo\n");
513 		} else
514 			printf(": ns16550, broken fifo\n");
515 	else
516 		printf(": ns8250 or ns16450, no fifo\n");
517 	bus_space_write_1(iot, ioh, com_fifo, 0);
518 	if (ISSET(sc->sc_hwflags, COM_HW_TXFIFO_DISABLE)) {
519 		sc->sc_fifolen = 1;
520 		printf("%s: txfifo disabled\n", sc->sc_dev.dv_xname);
521 	}
522 #ifdef COM_HAYESP
523 	}
524 #endif
525 
526 	tp = ttymalloc();
527 	tp->t_oproc = comstart;
528 	tp->t_param = comparam;
529 	tp->t_hwiflow = comhwiflow;
530 
531 	sc->sc_tty = tp;
532 	sc->sc_rbuf = malloc(com_rbuf_size << 1, M_DEVBUF, M_NOWAIT);
533 	sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
534 	sc->sc_rbavail = com_rbuf_size;
535 	if (sc->sc_rbuf == NULL) {
536 		printf("%s: unable to allocate ring buffer\n",
537 		    sc->sc_dev.dv_xname);
538 		return;
539 	}
540 	sc->sc_ebuf = sc->sc_rbuf + (com_rbuf_size << 1);
541 
542 	tty_attach(tp);
543 
544 	if (!ISSET(sc->sc_hwflags, COM_HW_NOIEN))
545 		SET(sc->sc_mcr, MCR_IENABLE);
546 
547 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
548 		int maj;
549 
550 		/* locate the major number */
551 		for (maj = 0; maj < nchrdev; maj++)
552 			if (cdevsw[maj].d_open == comopen)
553 				break;
554 
555 		cn_tab->cn_dev = makedev(maj, sc->sc_dev.dv_unit);
556 
557 		printf("%s: console\n", sc->sc_dev.dv_xname);
558 	}
559 
560 #ifdef KGDB
561 	/*
562 	 * Allow kgdb to "take over" this port.  If this is
563 	 * the kgdb device, it has exclusive use.
564 	 */
565 	if (iot == com_kgdb_iot && iobase == com_kgdb_addr) {
566 		com_kgdb_attached = 1;
567 
568 		SET(sc->sc_hwflags, COM_HW_KGDB);
569 		printf("%s: kgdb\n", sc->sc_dev.dv_xname);
570 	}
571 #endif
572 
573 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
574 	sc->sc_si = softintr_establish(IPL_SOFTSERIAL, comsoft, sc);
575 #endif
576 
577 #if NRND > 0 && defined(RND_COM)
578 	rnd_attach_source(&sc->rnd_source, sc->sc_dev.dv_xname,
579 			  RND_TYPE_TTY, 0);
580 #endif
581 
582 	/* if there are no enable/disable functions, assume the device
583 	   is always enabled */
584 	if (!sc->enable)
585 		sc->enabled = 1;
586 
587 	com_config(sc);
588 
589 	SET(sc->sc_hwflags, COM_HW_DEV_OK);
590 }
591 
592 void
593 com_config(sc)
594 	struct com_softc *sc;
595 {
596 	bus_space_tag_t iot = sc->sc_iot;
597 	bus_space_handle_t ioh = sc->sc_ioh;
598 
599 	/* Disable interrupts before configuring the device. */
600 	sc->sc_ier = 0;
601 	bus_space_write_1(iot, ioh, com_ier, sc->sc_ier);
602 
603 #ifdef COM_HAYESP
604 	/* Look for a Hayes ESP board. */
605 	if (ISSET(sc->sc_hwflags, COM_HW_HAYESP)) {
606 		sc->sc_fifolen = 1024;
607 
608 		/* Set 16550 compatibility mode */
609 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD1,
610 				  HAYESP_SETMODE);
611 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
612 				  HAYESP_MODE_FIFO|HAYESP_MODE_RTS|
613 				  HAYESP_MODE_SCALE);
614 
615 		/* Set RTS/CTS flow control */
616 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD1,
617 				  HAYESP_SETFLOWTYPE);
618 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
619 				  HAYESP_FLOW_RTS);
620 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
621 				  HAYESP_FLOW_CTS);
622 
623 		/* Set flow control levels */
624 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD1,
625 				  HAYESP_SETRXFLOW);
626 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
627 				  HAYESP_HIBYTE(HAYESP_RXHIWMARK));
628 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
629 				  HAYESP_LOBYTE(HAYESP_RXHIWMARK));
630 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
631 				  HAYESP_HIBYTE(HAYESP_RXLOWMARK));
632 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
633 				  HAYESP_LOBYTE(HAYESP_RXLOWMARK));
634 	}
635 #endif
636 
637 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE|COM_HW_KGDB))
638 		com_enable_debugport(sc);
639 }
640 
641 int
642 com_detach(self, flags)
643 	struct device *self;
644 	int flags;
645 {
646 	struct com_softc *sc = (struct com_softc *)self;
647 	int maj, mn;
648 
649 	/* locate the major number */
650 	for (maj = 0; maj < nchrdev; maj++)
651 		if (cdevsw[maj].d_open == comopen)
652 			break;
653 
654 	/* Nuke the vnodes for any open instances. */
655 	mn = self->dv_unit;
656 	vdevgone(maj, mn, mn, VCHR);
657 
658 	mn |= COMDIALOUT_MASK;
659 	vdevgone(maj, mn, mn, VCHR);
660 
661 	/* Free the receive buffer. */
662 	free(sc->sc_rbuf, M_DEVBUF);
663 
664 	/* Detach and free the tty. */
665 	tty_detach(sc->sc_tty);
666 	ttyfree(sc->sc_tty);
667 
668 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
669 	/* Unhook the soft interrupt handler. */
670 	softintr_disestablish(sc->sc_si);
671 #endif
672 
673 #if NRND > 0 && defined(RND_COM)
674 	/* Unhook the entropy source. */
675 	rnd_detach_source(&sc->rnd_source);
676 #endif
677 
678 	return (0);
679 }
680 
681 int
682 com_activate(self, act)
683 	struct device *self;
684 	enum devact act;
685 {
686 	struct com_softc *sc = (struct com_softc *)self;
687 	int s, rv = 0;
688 
689 	s = splserial();
690 	COM_LOCK(sc);
691 	switch (act) {
692 	case DVACT_ACTIVATE:
693 		rv = EOPNOTSUPP;
694 		break;
695 
696 	case DVACT_DEACTIVATE:
697 		if (sc->sc_hwflags & (COM_HW_CONSOLE|COM_HW_KGDB)) {
698 			rv = EBUSY;
699 			break;
700 		}
701 
702 		if (sc->disable != NULL && sc->enabled != 0) {
703 			(*sc->disable)(sc);
704 			sc->enabled = 0;
705 		}
706 		break;
707 	}
708 
709 	COM_UNLOCK(sc);
710 	splx(s);
711 	return (rv);
712 }
713 
714 void
715 com_shutdown(sc)
716 	struct com_softc *sc;
717 {
718 	struct tty *tp = sc->sc_tty;
719 	int s;
720 
721 	s = splserial();
722 	COM_LOCK(sc);
723 
724 	/* If we were asserting flow control, then deassert it. */
725 	SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
726 	com_hwiflow(sc);
727 
728 	/* Clear any break condition set with TIOCSBRK. */
729 	com_break(sc, 0);
730 
731 	/* Turn off PPS capture on last close. */
732 	sc->sc_ppsmask = 0;
733 	sc->ppsparam.mode = 0;
734 
735 	/*
736 	 * Hang up if necessary.  Wait a bit, so the other side has time to
737 	 * notice even if we immediately open the port again.
738 	 * Avoid tsleeping above splhigh().
739 	 */
740 	if (ISSET(tp->t_cflag, HUPCL)) {
741 		com_modem(sc, 0);
742 		COM_UNLOCK(sc);
743 		splx(s);
744 		/* XXX tsleep will only timeout */
745 		(void) tsleep(sc, TTIPRI, ttclos, hz);
746 		s = splserial();
747 		COM_LOCK(sc);
748 	}
749 
750 	/* Turn off interrupts. */
751 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE))
752 		sc->sc_ier = IER_ERXRDY; /* interrupt on break */
753 	else
754 		sc->sc_ier = 0;
755 	bus_space_write_1(sc->sc_iot, sc->sc_ioh, com_ier, sc->sc_ier);
756 
757 	if (sc->disable) {
758 #ifdef DIAGNOSTIC
759 		if (!sc->enabled)
760 			panic("com_shutdown: not enabled?");
761 #endif
762 		(*sc->disable)(sc);
763 		sc->enabled = 0;
764 	}
765 	COM_UNLOCK(sc);
766 	splx(s);
767 }
768 
769 int
770 comopen(dev, flag, mode, p)
771 	dev_t dev;
772 	int flag, mode;
773 	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, flag, mode, p)
924 	dev_t dev;
925 	int flag, mode;
926 	struct proc *p;
927 {
928 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(dev));
929 	struct tty *tp = sc->sc_tty;
930 
931 	/* XXX This is for cons.c. */
932 	if (!ISSET(tp->t_state, TS_ISOPEN))
933 		return (0);
934 
935 	(*tp->t_linesw->l_close)(tp, flag);
936 	ttyclose(tp);
937 
938 	if (COM_ISALIVE(sc) == 0)
939 		return (0);
940 
941 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
942 		/*
943 		 * Although we got a last close, the device may still be in
944 		 * use; e.g. if this was the dialout node, and there are still
945 		 * processes waiting for carrier on the non-dialout node.
946 		 */
947 		com_shutdown(sc);
948 	}
949 
950 	return (0);
951 }
952 
953 int
954 comread(dev, uio, flag)
955 	dev_t dev;
956 	struct uio *uio;
957 	int flag;
958 {
959 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(dev));
960 	struct tty *tp = sc->sc_tty;
961 
962 	if (COM_ISALIVE(sc) == 0)
963 		return (EIO);
964 
965 	return ((*tp->t_linesw->l_read)(tp, uio, flag));
966 }
967 
968 int
969 comwrite(dev, uio, flag)
970 	dev_t dev;
971 	struct uio *uio;
972 	int flag;
973 {
974 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(dev));
975 	struct tty *tp = sc->sc_tty;
976 
977 	if (COM_ISALIVE(sc) == 0)
978 		return (EIO);
979 
980 	return ((*tp->t_linesw->l_write)(tp, uio, flag));
981 }
982 
983 int
984 compoll(dev, events, p)
985 	dev_t dev;
986 	int events;
987 	struct proc *p;
988 {
989 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(dev));
990 	struct tty *tp = sc->sc_tty;
991 
992 	if (COM_ISALIVE(sc) == 0)
993 		return (EIO);
994 
995 	return ((*tp->t_linesw->l_poll)(tp, events, p));
996 }
997 
998 struct tty *
999 comtty(dev)
1000 	dev_t dev;
1001 {
1002 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(dev));
1003 	struct tty *tp = sc->sc_tty;
1004 
1005 	return (tp);
1006 }
1007 
1008 int
1009 comioctl(dev, cmd, data, flag, p)
1010 	dev_t dev;
1011 	u_long cmd;
1012 	caddr_t data;
1013 	int flag;
1014 	struct proc *p;
1015 {
1016 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(dev));
1017 	struct tty *tp = sc->sc_tty;
1018 	int error;
1019 	int s;
1020 
1021 	if (COM_ISALIVE(sc) == 0)
1022 		return (EIO);
1023 
1024 	error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, p);
1025 	if (error >= 0)
1026 		return (error);
1027 
1028 	error = ttioctl(tp, cmd, data, flag, p);
1029 	if (error >= 0)
1030 		return (error);
1031 
1032 	error = 0;
1033 
1034 	s = splserial();
1035 	COM_LOCK(sc);
1036 
1037 	switch (cmd) {
1038 	case TIOCSBRK:
1039 		com_break(sc, 1);
1040 		break;
1041 
1042 	case TIOCCBRK:
1043 		com_break(sc, 0);
1044 		break;
1045 
1046 	case TIOCSDTR:
1047 		com_modem(sc, 1);
1048 		break;
1049 
1050 	case TIOCCDTR:
1051 		com_modem(sc, 0);
1052 		break;
1053 
1054 	case TIOCGFLAGS:
1055 		*(int *)data = sc->sc_swflags;
1056 		break;
1057 
1058 	case TIOCSFLAGS:
1059 		error = suser(p->p_ucred, &p->p_acflag);
1060 		if (error)
1061 			break;
1062 		sc->sc_swflags = *(int *)data;
1063 		break;
1064 
1065 	case TIOCMSET:
1066 	case TIOCMBIS:
1067 	case TIOCMBIC:
1068 		tiocm_to_com(sc, cmd, *(int *)data);
1069 		break;
1070 
1071 	case TIOCMGET:
1072 		*(int *)data = com_to_tiocm(sc);
1073 		break;
1074 
1075 	case PPS_IOC_CREATE:
1076 		break;
1077 
1078 	case PPS_IOC_DESTROY:
1079 		break;
1080 
1081 	case PPS_IOC_GETPARAMS: {
1082 		pps_params_t *pp;
1083 		pp = (pps_params_t *)data;
1084 		*pp = sc->ppsparam;
1085 		break;
1086 	}
1087 
1088 	case PPS_IOC_SETPARAMS: {
1089 	  	pps_params_t *pp;
1090 		int mode;
1091 		pp = (pps_params_t *)data;
1092 		if (pp->mode & ~ppscap) {
1093 			error = EINVAL;
1094 			break;
1095 		}
1096 		sc->ppsparam = *pp;
1097 	 	/*
1098 		 * Compute msr masks from user-specified timestamp state.
1099 		 */
1100 		mode = sc->ppsparam.mode;
1101 #ifdef	PPS_SYNC
1102 		if (mode & PPS_HARDPPSONASSERT) {
1103 			mode |= PPS_CAPTUREASSERT;
1104 			/* XXX revoke any previous HARDPPS source */
1105 		}
1106 		if (mode & PPS_HARDPPSONCLEAR) {
1107 			mode |= PPS_CAPTURECLEAR;
1108 			/* XXX revoke any previous HARDPPS source */
1109 		}
1110 #endif	/* PPS_SYNC */
1111 		switch (mode & PPS_CAPTUREBOTH) {
1112 		case 0:
1113 			sc->sc_ppsmask = 0;
1114 			break;
1115 
1116 		case PPS_CAPTUREASSERT:
1117 			sc->sc_ppsmask = MSR_DCD;
1118 			sc->sc_ppsassert = MSR_DCD;
1119 			sc->sc_ppsclear = -1;
1120 			break;
1121 
1122 		case PPS_CAPTURECLEAR:
1123 			sc->sc_ppsmask = MSR_DCD;
1124 			sc->sc_ppsassert = -1;
1125 			sc->sc_ppsclear = 0;
1126 			break;
1127 
1128 		case PPS_CAPTUREBOTH:
1129 			sc->sc_ppsmask = MSR_DCD;
1130 			sc->sc_ppsassert = MSR_DCD;
1131 			sc->sc_ppsclear = 0;
1132 			break;
1133 
1134 		default:
1135 			error = EINVAL;
1136 			break;
1137 		}
1138 		break;
1139 	}
1140 
1141 	case PPS_IOC_GETCAP:
1142 		*(int*)data = ppscap;
1143 		break;
1144 
1145 	case PPS_IOC_FETCH: {
1146 		pps_info_t *pi;
1147 		pi = (pps_info_t *)data;
1148 		*pi = sc->ppsinfo;
1149 		break;
1150 	}
1151 
1152 	case TIOCDCDTIMESTAMP:	/* XXX old, overloaded  API used by xntpd v3 */
1153 		/*
1154 		 * Some GPS clocks models use the falling rather than
1155 		 * rising edge as the on-the-second signal.
1156 		 * The old API has no way to specify PPS polarity.
1157 		 */
1158 		sc->sc_ppsmask = MSR_DCD;
1159 #ifndef PPS_TRAILING_EDGE
1160 		sc->sc_ppsassert = MSR_DCD;
1161 		sc->sc_ppsclear = -1;
1162 		TIMESPEC_TO_TIMEVAL((struct timeval *)data,
1163 		    &sc->ppsinfo.assert_timestamp);
1164 #else
1165 		sc->sc_ppsassert = -1
1166 		sc->sc_ppsclear = 0;
1167 		TIMESPEC_TO_TIMEVAL((struct timeval *)data,
1168 		    &sc->ppsinfo.clear_timestamp);
1169 #endif
1170 		break;
1171 
1172 	default:
1173 		error = ENOTTY;
1174 		break;
1175 	}
1176 
1177 	COM_UNLOCK(sc);
1178 	splx(s);
1179 
1180 #ifdef COM_DEBUG
1181 	if (com_debug)
1182 		comstatus(sc, "comioctl ");
1183 #endif
1184 
1185 	return (error);
1186 }
1187 
1188 integrate void
1189 com_schedrx(sc)
1190 	struct com_softc *sc;
1191 {
1192 
1193 	sc->sc_rx_ready = 1;
1194 
1195 	/* Wake up the poller. */
1196 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
1197 	softintr_schedule(sc->sc_si);
1198 #else
1199 #ifndef __NO_SOFT_SERIAL_INTERRUPT
1200 	setsoftserial();
1201 #else
1202 	if (!com_softintr_scheduled) {
1203 		com_softintr_scheduled = 1;
1204 		callout_reset(&comsoft_callout, 1, comsoft, NULL);
1205 	}
1206 #endif
1207 #endif
1208 }
1209 
1210 void
1211 com_break(sc, onoff)
1212 	struct com_softc *sc;
1213 	int onoff;
1214 {
1215 
1216 	if (onoff)
1217 		SET(sc->sc_lcr, LCR_SBREAK);
1218 	else
1219 		CLR(sc->sc_lcr, LCR_SBREAK);
1220 
1221 	if (!sc->sc_heldchange) {
1222 		if (sc->sc_tx_busy) {
1223 			sc->sc_heldtbc = sc->sc_tbc;
1224 			sc->sc_tbc = 0;
1225 			sc->sc_heldchange = 1;
1226 		} else
1227 			com_loadchannelregs(sc);
1228 	}
1229 }
1230 
1231 void
1232 com_modem(sc, onoff)
1233 	struct com_softc *sc;
1234 	int onoff;
1235 {
1236 
1237 	if (sc->sc_mcr_dtr == 0)
1238 		return;
1239 
1240 	if (onoff)
1241 		SET(sc->sc_mcr, sc->sc_mcr_dtr);
1242 	else
1243 		CLR(sc->sc_mcr, sc->sc_mcr_dtr);
1244 
1245 	if (!sc->sc_heldchange) {
1246 		if (sc->sc_tx_busy) {
1247 			sc->sc_heldtbc = sc->sc_tbc;
1248 			sc->sc_tbc = 0;
1249 			sc->sc_heldchange = 1;
1250 		} else
1251 			com_loadchannelregs(sc);
1252 	}
1253 }
1254 
1255 void
1256 tiocm_to_com(sc, how, ttybits)
1257 	struct com_softc *sc;
1258 	u_long how;
1259 	int ttybits;
1260 {
1261 	u_char combits;
1262 
1263 	combits = 0;
1264 	if (ISSET(ttybits, TIOCM_DTR))
1265 		SET(combits, MCR_DTR);
1266 	if (ISSET(ttybits, TIOCM_RTS))
1267 		SET(combits, MCR_RTS);
1268 
1269 	switch (how) {
1270 	case TIOCMBIC:
1271 		CLR(sc->sc_mcr, combits);
1272 		break;
1273 
1274 	case TIOCMBIS:
1275 		SET(sc->sc_mcr, combits);
1276 		break;
1277 
1278 	case TIOCMSET:
1279 		CLR(sc->sc_mcr, MCR_DTR | MCR_RTS);
1280 		SET(sc->sc_mcr, combits);
1281 		break;
1282 	}
1283 
1284 	if (!sc->sc_heldchange) {
1285 		if (sc->sc_tx_busy) {
1286 			sc->sc_heldtbc = sc->sc_tbc;
1287 			sc->sc_tbc = 0;
1288 			sc->sc_heldchange = 1;
1289 		} else
1290 			com_loadchannelregs(sc);
1291 	}
1292 }
1293 
1294 int
1295 com_to_tiocm(sc)
1296 	struct com_softc *sc;
1297 {
1298 	u_char combits;
1299 	int ttybits = 0;
1300 
1301 	combits = sc->sc_mcr;
1302 	if (ISSET(combits, MCR_DTR))
1303 		SET(ttybits, TIOCM_DTR);
1304 	if (ISSET(combits, MCR_RTS))
1305 		SET(ttybits, TIOCM_RTS);
1306 
1307 	combits = sc->sc_msr;
1308 	if (ISSET(combits, MSR_DCD))
1309 		SET(ttybits, TIOCM_CD);
1310 	if (ISSET(combits, MSR_CTS))
1311 		SET(ttybits, TIOCM_CTS);
1312 	if (ISSET(combits, MSR_DSR))
1313 		SET(ttybits, TIOCM_DSR);
1314 	if (ISSET(combits, MSR_RI | MSR_TERI))
1315 		SET(ttybits, TIOCM_RI);
1316 
1317 	if (sc->sc_ier != 0)
1318 		SET(ttybits, TIOCM_LE);
1319 
1320 	return (ttybits);
1321 }
1322 
1323 static u_char
1324 cflag2lcr(cflag)
1325 	tcflag_t cflag;
1326 {
1327 	u_char lcr = 0;
1328 
1329 	switch (ISSET(cflag, CSIZE)) {
1330 	case CS5:
1331 		SET(lcr, LCR_5BITS);
1332 		break;
1333 	case CS6:
1334 		SET(lcr, LCR_6BITS);
1335 		break;
1336 	case CS7:
1337 		SET(lcr, LCR_7BITS);
1338 		break;
1339 	case CS8:
1340 		SET(lcr, LCR_8BITS);
1341 		break;
1342 	}
1343 	if (ISSET(cflag, PARENB)) {
1344 		SET(lcr, LCR_PENAB);
1345 		if (!ISSET(cflag, PARODD))
1346 			SET(lcr, LCR_PEVEN);
1347 	}
1348 	if (ISSET(cflag, CSTOPB))
1349 		SET(lcr, LCR_STOPB);
1350 
1351 	return (lcr);
1352 }
1353 
1354 int
1355 comparam(tp, t)
1356 	struct tty *tp;
1357 	struct termios *t;
1358 {
1359 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(tp->t_dev));
1360 	int ospeed = comspeed(t->c_ospeed, sc->sc_frequency);
1361 	u_char lcr;
1362 	int s;
1363 
1364 	if (COM_ISALIVE(sc) == 0)
1365 		return (EIO);
1366 
1367 	/* Check requested parameters. */
1368 	if (ospeed < 0)
1369 		return (EINVAL);
1370 	if (t->c_ispeed && t->c_ispeed != t->c_ospeed)
1371 		return (EINVAL);
1372 
1373 	/*
1374 	 * For the console, always force CLOCAL and !HUPCL, so that the port
1375 	 * is always active.
1376 	 */
1377 	if (ISSET(sc->sc_swflags, TIOCFLAG_SOFTCAR) ||
1378 	    ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
1379 		SET(t->c_cflag, CLOCAL);
1380 		CLR(t->c_cflag, HUPCL);
1381 	}
1382 
1383 	/*
1384 	 * If there were no changes, don't do anything.  This avoids dropping
1385 	 * input and improves performance when all we did was frob things like
1386 	 * VMIN and VTIME.
1387 	 */
1388 	if (tp->t_ospeed == t->c_ospeed &&
1389 	    tp->t_cflag == t->c_cflag)
1390 		return (0);
1391 
1392 	lcr = ISSET(sc->sc_lcr, LCR_SBREAK) | cflag2lcr(t->c_cflag);
1393 
1394 	s = splserial();
1395 	COM_LOCK(sc);
1396 
1397 	sc->sc_lcr = lcr;
1398 
1399 	/*
1400 	 * If we're not in a mode that assumes a connection is present, then
1401 	 * ignore carrier changes.
1402 	 */
1403 	if (ISSET(t->c_cflag, CLOCAL | MDMBUF))
1404 		sc->sc_msr_dcd = 0;
1405 	else
1406 		sc->sc_msr_dcd = MSR_DCD;
1407 	/*
1408 	 * Set the flow control pins depending on the current flow control
1409 	 * mode.
1410 	 */
1411 	if (ISSET(t->c_cflag, CRTSCTS)) {
1412 		sc->sc_mcr_dtr = MCR_DTR;
1413 		sc->sc_mcr_rts = MCR_RTS;
1414 		sc->sc_msr_cts = MSR_CTS;
1415 		sc->sc_efr = EFR_AUTORTS | EFR_AUTOCTS;
1416 	} else if (ISSET(t->c_cflag, MDMBUF)) {
1417 		/*
1418 		 * For DTR/DCD flow control, make sure we don't toggle DTR for
1419 		 * carrier detection.
1420 		 */
1421 		sc->sc_mcr_dtr = 0;
1422 		sc->sc_mcr_rts = MCR_DTR;
1423 		sc->sc_msr_cts = MSR_DCD;
1424 		sc->sc_efr = 0;
1425 	} else {
1426 		/*
1427 		 * If no flow control, then always set RTS.  This will make
1428 		 * the other side happy if it mistakenly thinks we're doing
1429 		 * RTS/CTS flow control.
1430 		 */
1431 		sc->sc_mcr_dtr = MCR_DTR | MCR_RTS;
1432 		sc->sc_mcr_rts = 0;
1433 		sc->sc_msr_cts = 0;
1434 		sc->sc_efr = 0;
1435 		if (ISSET(sc->sc_mcr, MCR_DTR))
1436 			SET(sc->sc_mcr, MCR_RTS);
1437 		else
1438 			CLR(sc->sc_mcr, MCR_RTS);
1439 	}
1440 	sc->sc_msr_mask = sc->sc_msr_cts | sc->sc_msr_dcd;
1441 
1442 #if 0
1443 	if (ospeed == 0)
1444 		CLR(sc->sc_mcr, sc->sc_mcr_dtr);
1445 	else
1446 		SET(sc->sc_mcr, sc->sc_mcr_dtr);
1447 #endif
1448 
1449 	sc->sc_dlbl = ospeed;
1450 	sc->sc_dlbh = ospeed >> 8;
1451 
1452 	/*
1453 	 * Set the FIFO threshold based on the receive speed.
1454 	 *
1455 	 *  * If it's a low speed, it's probably a mouse or some other
1456 	 *    interactive device, so set the threshold low.
1457 	 *  * If it's a high speed, trim the trigger level down to prevent
1458 	 *    overflows.
1459 	 *  * Otherwise set it a bit higher.
1460 	 */
1461 	if (ISSET(sc->sc_hwflags, COM_HW_HAYESP))
1462 		sc->sc_fifo = FIFO_DMA_MODE | FIFO_ENABLE | FIFO_TRIGGER_8;
1463 	else if (ISSET(sc->sc_hwflags, COM_HW_FIFO))
1464 		sc->sc_fifo = FIFO_ENABLE |
1465 		    (t->c_ospeed <= 1200 ? FIFO_TRIGGER_1 :
1466 		     t->c_ospeed <= 38400 ? FIFO_TRIGGER_8 : FIFO_TRIGGER_4);
1467 	else
1468 		sc->sc_fifo = 0;
1469 
1470 	/* And copy to tty. */
1471 	tp->t_ispeed = 0;
1472 	tp->t_ospeed = t->c_ospeed;
1473 	tp->t_cflag = t->c_cflag;
1474 
1475 	if (!sc->sc_heldchange) {
1476 		if (sc->sc_tx_busy) {
1477 			sc->sc_heldtbc = sc->sc_tbc;
1478 			sc->sc_tbc = 0;
1479 			sc->sc_heldchange = 1;
1480 		} else
1481 			com_loadchannelregs(sc);
1482 	}
1483 
1484 	if (!ISSET(t->c_cflag, CHWFLOW)) {
1485 		/* Disable the high water mark. */
1486 		sc->sc_r_hiwat = 0;
1487 		sc->sc_r_lowat = 0;
1488 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
1489 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1490 			com_schedrx(sc);
1491 		}
1492 		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED)) {
1493 			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED);
1494 			com_hwiflow(sc);
1495 		}
1496 	} else {
1497 		sc->sc_r_hiwat = com_rbuf_hiwat;
1498 		sc->sc_r_lowat = com_rbuf_lowat;
1499 	}
1500 
1501 	COM_UNLOCK(sc);
1502 	splx(s);
1503 
1504 	/*
1505 	 * Update the tty layer's idea of the carrier bit, in case we changed
1506 	 * CLOCAL or MDMBUF.  We don't hang up here; we only do that by
1507 	 * explicit request.
1508 	 */
1509 	(void) (*tp->t_linesw->l_modem)(tp, ISSET(sc->sc_msr, MSR_DCD));
1510 
1511 #ifdef COM_DEBUG
1512 	if (com_debug)
1513 		comstatus(sc, "comparam ");
1514 #endif
1515 
1516 	if (!ISSET(t->c_cflag, CHWFLOW)) {
1517 		if (sc->sc_tx_stopped) {
1518 			sc->sc_tx_stopped = 0;
1519 			comstart(tp);
1520 		}
1521 	}
1522 
1523 	return (0);
1524 }
1525 
1526 void
1527 com_iflush(sc)
1528 	struct com_softc *sc;
1529 {
1530 	bus_space_tag_t iot = sc->sc_iot;
1531 	bus_space_handle_t ioh = sc->sc_ioh;
1532 #ifdef DIAGNOSTIC
1533 	int reg;
1534 #endif
1535 	int timo;
1536 
1537 #ifdef DIAGNOSTIC
1538 	reg = 0xffff;
1539 #endif
1540 	timo = 50000;
1541 	/* flush any pending I/O */
1542 	while (ISSET(bus_space_read_1(iot, ioh, com_lsr), LSR_RXRDY)
1543 	    && --timo)
1544 #ifdef DIAGNOSTIC
1545 		reg =
1546 #else
1547 		    (void)
1548 #endif
1549 		    bus_space_read_1(iot, ioh, com_data);
1550 #ifdef DIAGNOSTIC
1551 	if (!timo)
1552 		printf("%s: com_iflush timeout %02x\n", sc->sc_dev.dv_xname,
1553 		       reg);
1554 #endif
1555 }
1556 
1557 void
1558 com_loadchannelregs(sc)
1559 	struct com_softc *sc;
1560 {
1561 	bus_space_tag_t iot = sc->sc_iot;
1562 	bus_space_handle_t ioh = sc->sc_ioh;
1563 
1564 	/* XXXXX necessary? */
1565 	com_iflush(sc);
1566 
1567 	bus_space_write_1(iot, ioh, com_ier, 0);
1568 
1569 	if (ISSET(sc->sc_hwflags, COM_HW_FLOW)) {
1570 		bus_space_write_1(iot, ioh, com_lcr, LCR_EERS);
1571 		bus_space_write_1(iot, ioh, com_efr, sc->sc_efr);
1572 	}
1573 	bus_space_write_1(iot, ioh, com_lcr, sc->sc_lcr | LCR_DLAB);
1574 	bus_space_write_1(iot, ioh, com_dlbl, sc->sc_dlbl);
1575 	bus_space_write_1(iot, ioh, com_dlbh, sc->sc_dlbh);
1576 	bus_space_write_1(iot, ioh, com_lcr, sc->sc_lcr);
1577 	bus_space_write_1(iot, ioh, com_mcr, sc->sc_mcr_active = sc->sc_mcr);
1578 	bus_space_write_1(iot, ioh, com_fifo, sc->sc_fifo);
1579 
1580 	bus_space_write_1(iot, ioh, com_ier, sc->sc_ier);
1581 }
1582 
1583 int
1584 comhwiflow(tp, block)
1585 	struct tty *tp;
1586 	int block;
1587 {
1588 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(tp->t_dev));
1589 	int s;
1590 
1591 	if (COM_ISALIVE(sc) == 0)
1592 		return (0);
1593 
1594 	if (sc->sc_mcr_rts == 0)
1595 		return (0);
1596 
1597 	s = splserial();
1598 	COM_LOCK(sc);
1599 
1600 	if (block) {
1601 		if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1602 			SET(sc->sc_rx_flags, RX_TTY_BLOCKED);
1603 			com_hwiflow(sc);
1604 		}
1605 	} else {
1606 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
1607 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1608 			com_schedrx(sc);
1609 		}
1610 		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1611 			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED);
1612 			com_hwiflow(sc);
1613 		}
1614 	}
1615 
1616 	COM_UNLOCK(sc);
1617 	splx(s);
1618 	return (1);
1619 }
1620 
1621 /*
1622  * (un)block input via hw flowcontrol
1623  */
1624 void
1625 com_hwiflow(sc)
1626 	struct com_softc *sc;
1627 {
1628 	bus_space_tag_t iot = sc->sc_iot;
1629 	bus_space_handle_t ioh = sc->sc_ioh;
1630 
1631 	if (sc->sc_mcr_rts == 0)
1632 		return;
1633 
1634 	if (ISSET(sc->sc_rx_flags, RX_ANY_BLOCK)) {
1635 		CLR(sc->sc_mcr, sc->sc_mcr_rts);
1636 		CLR(sc->sc_mcr_active, sc->sc_mcr_rts);
1637 	} else {
1638 		SET(sc->sc_mcr, sc->sc_mcr_rts);
1639 		SET(sc->sc_mcr_active, sc->sc_mcr_rts);
1640 	}
1641 	bus_space_write_1(iot, ioh, com_mcr, sc->sc_mcr_active);
1642 }
1643 
1644 
1645 void
1646 comstart(tp)
1647 	struct tty *tp;
1648 {
1649 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(tp->t_dev));
1650 	bus_space_tag_t iot = sc->sc_iot;
1651 	bus_space_handle_t ioh = sc->sc_ioh;
1652 	int s;
1653 
1654 	if (COM_ISALIVE(sc) == 0)
1655 		return;
1656 
1657 	s = spltty();
1658 	if (ISSET(tp->t_state, TS_BUSY | TS_TIMEOUT | TS_TTSTOP))
1659 		goto out;
1660 	if (sc->sc_tx_stopped)
1661 		goto out;
1662 
1663 	if (tp->t_outq.c_cc <= tp->t_lowat) {
1664 		if (ISSET(tp->t_state, TS_ASLEEP)) {
1665 			CLR(tp->t_state, TS_ASLEEP);
1666 			wakeup(&tp->t_outq);
1667 		}
1668 		selwakeup(&tp->t_wsel);
1669 		if (tp->t_outq.c_cc == 0)
1670 			goto out;
1671 	}
1672 
1673 	/* Grab the first contiguous region of buffer space. */
1674 	{
1675 		u_char *tba;
1676 		int tbc;
1677 
1678 		tba = tp->t_outq.c_cf;
1679 		tbc = ndqb(&tp->t_outq, 0);
1680 
1681 		(void)splserial();
1682 		COM_LOCK(sc);
1683 
1684 		sc->sc_tba = tba;
1685 		sc->sc_tbc = tbc;
1686 	}
1687 
1688 	SET(tp->t_state, TS_BUSY);
1689 	sc->sc_tx_busy = 1;
1690 
1691 	/* Enable transmit completion interrupts if necessary. */
1692 	if (!ISSET(sc->sc_ier, IER_ETXRDY)) {
1693 		SET(sc->sc_ier, IER_ETXRDY);
1694 		bus_space_write_1(iot, ioh, com_ier, sc->sc_ier);
1695 	}
1696 
1697 	/* Output the first chunk of the contiguous buffer. */
1698 	{
1699 		int n;
1700 
1701 		n = sc->sc_tbc;
1702 		if (n > sc->sc_fifolen)
1703 			n = sc->sc_fifolen;
1704 		bus_space_write_multi_1(iot, ioh, com_data, sc->sc_tba, n);
1705 		sc->sc_tbc -= n;
1706 		sc->sc_tba += n;
1707 	}
1708 	COM_UNLOCK(sc);
1709 out:
1710 	splx(s);
1711 	return;
1712 }
1713 
1714 /*
1715  * Stop output on a line.
1716  */
1717 void
1718 comstop(tp, flag)
1719 	struct tty *tp;
1720 	int flag;
1721 {
1722 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(tp->t_dev));
1723 	int s;
1724 
1725 	s = splserial();
1726 	COM_LOCK(sc);
1727 	if (ISSET(tp->t_state, TS_BUSY)) {
1728 		/* Stop transmitting at the next chunk. */
1729 		sc->sc_tbc = 0;
1730 		sc->sc_heldtbc = 0;
1731 		if (!ISSET(tp->t_state, TS_TTSTOP))
1732 			SET(tp->t_state, TS_FLUSH);
1733 	}
1734 	COM_UNLOCK(sc);
1735 	splx(s);
1736 }
1737 
1738 void
1739 comdiag(arg)
1740 	void *arg;
1741 {
1742 	struct com_softc *sc = arg;
1743 	int overflows, floods;
1744 	int s;
1745 
1746 	s = splserial();
1747 	COM_LOCK(sc);
1748 	overflows = sc->sc_overflows;
1749 	sc->sc_overflows = 0;
1750 	floods = sc->sc_floods;
1751 	sc->sc_floods = 0;
1752 	sc->sc_errors = 0;
1753 	COM_UNLOCK(sc);
1754 	splx(s);
1755 
1756 	log(LOG_WARNING, "%s: %d silo overflow%s, %d ibuf flood%s\n",
1757 	    sc->sc_dev.dv_xname,
1758 	    overflows, overflows == 1 ? "" : "s",
1759 	    floods, floods == 1 ? "" : "s");
1760 }
1761 
1762 integrate void
1763 com_rxsoft(sc, tp)
1764 	struct com_softc *sc;
1765 	struct tty *tp;
1766 {
1767 	int (*rint) __P((int c, struct tty *tp)) = tp->t_linesw->l_rint;
1768 	u_char *get, *end;
1769 	u_int cc, scc;
1770 	u_char lsr;
1771 	int code;
1772 	int s;
1773 
1774 	end = sc->sc_ebuf;
1775 	get = sc->sc_rbget;
1776 	scc = cc = com_rbuf_size - sc->sc_rbavail;
1777 
1778 	if (cc == com_rbuf_size) {
1779 		sc->sc_floods++;
1780 		if (sc->sc_errors++ == 0)
1781 			callout_reset(&sc->sc_diag_callout, 60 * hz,
1782 			    comdiag, sc);
1783 	}
1784 
1785 	while (cc) {
1786 		code = get[0];
1787 		lsr = get[1];
1788 		if (ISSET(lsr, LSR_OE | LSR_BI | LSR_FE | LSR_PE)) {
1789 			if (ISSET(lsr, LSR_OE)) {
1790 				sc->sc_overflows++;
1791 				if (sc->sc_errors++ == 0)
1792 					callout_reset(&sc->sc_diag_callout,
1793 					    60 * hz, comdiag, sc);
1794 			}
1795 			if (ISSET(lsr, LSR_BI | LSR_FE))
1796 				SET(code, TTY_FE);
1797 			if (ISSET(lsr, LSR_PE))
1798 				SET(code, TTY_PE);
1799 		}
1800 		if ((*rint)(code, tp) == -1) {
1801 			/*
1802 			 * The line discipline's buffer is out of space.
1803 			 */
1804 			if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1805 				/*
1806 				 * We're either not using flow control, or the
1807 				 * line discipline didn't tell us to block for
1808 				 * some reason.  Either way, we have no way to
1809 				 * know when there's more space available, so
1810 				 * just drop the rest of the data.
1811 				 */
1812 				get += cc << 1;
1813 				if (get >= end)
1814 					get -= com_rbuf_size << 1;
1815 				cc = 0;
1816 			} else {
1817 				/*
1818 				 * Don't schedule any more receive processing
1819 				 * until the line discipline tells us there's
1820 				 * space available (through comhwiflow()).
1821 				 * Leave the rest of the data in the input
1822 				 * buffer.
1823 				 */
1824 				SET(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1825 			}
1826 			break;
1827 		}
1828 		get += 2;
1829 		if (get >= end)
1830 			get = sc->sc_rbuf;
1831 		cc--;
1832 	}
1833 
1834 	if (cc != scc) {
1835 		sc->sc_rbget = get;
1836 		s = splserial();
1837 		COM_LOCK(sc);
1838 
1839 		cc = sc->sc_rbavail += scc - cc;
1840 		/* Buffers should be ok again, release possible block. */
1841 		if (cc >= sc->sc_r_lowat) {
1842 			if (ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
1843 				CLR(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
1844 				SET(sc->sc_ier, IER_ERXRDY);
1845 				bus_space_write_1(sc->sc_iot, sc->sc_ioh, com_ier, sc->sc_ier);
1846 			}
1847 			if (ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED)) {
1848 				CLR(sc->sc_rx_flags, RX_IBUF_BLOCKED);
1849 				com_hwiflow(sc);
1850 			}
1851 		}
1852 		COM_UNLOCK(sc);
1853 		splx(s);
1854 	}
1855 }
1856 
1857 integrate void
1858 com_txsoft(sc, tp)
1859 	struct com_softc *sc;
1860 	struct tty *tp;
1861 {
1862 
1863 	CLR(tp->t_state, TS_BUSY);
1864 	if (ISSET(tp->t_state, TS_FLUSH))
1865 		CLR(tp->t_state, TS_FLUSH);
1866 	else
1867 		ndflush(&tp->t_outq, (int)(sc->sc_tba - tp->t_outq.c_cf));
1868 	(*tp->t_linesw->l_start)(tp);
1869 }
1870 
1871 integrate void
1872 com_stsoft(sc, tp)
1873 	struct com_softc *sc;
1874 	struct tty *tp;
1875 {
1876 	u_char msr, delta;
1877 	int s;
1878 
1879 	s = splserial();
1880 	COM_LOCK(sc);
1881 	msr = sc->sc_msr;
1882 	delta = sc->sc_msr_delta;
1883 	sc->sc_msr_delta = 0;
1884 	COM_UNLOCK(sc);
1885 	splx(s);
1886 
1887 	if (ISSET(delta, sc->sc_msr_dcd)) {
1888 		/*
1889 		 * Inform the tty layer that carrier detect changed.
1890 		 */
1891 		(void) (*tp->t_linesw->l_modem)(tp, ISSET(msr, MSR_DCD));
1892 	}
1893 
1894 	if (ISSET(delta, sc->sc_msr_cts)) {
1895 		/* Block or unblock output according to flow control. */
1896 		if (ISSET(msr, sc->sc_msr_cts)) {
1897 			sc->sc_tx_stopped = 0;
1898 			(*tp->t_linesw->l_start)(tp);
1899 		} else {
1900 			sc->sc_tx_stopped = 1;
1901 		}
1902 	}
1903 
1904 #ifdef COM_DEBUG
1905 	if (com_debug)
1906 		comstatus(sc, "com_stsoft");
1907 #endif
1908 }
1909 
1910 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
1911 void
1912 comsoft(arg)
1913 	void *arg;
1914 {
1915 	struct com_softc *sc = arg;
1916 	struct tty *tp;
1917 
1918 	if (COM_ISALIVE(sc) == 0)
1919 		return;
1920 
1921 	{
1922 #else
1923 void
1924 #ifndef __NO_SOFT_SERIAL_INTERRUPT
1925 comsoft()
1926 #else
1927 comsoft(arg)
1928 	void *arg;
1929 #endif
1930 {
1931 	struct com_softc	*sc;
1932 	struct tty	*tp;
1933 	int	unit;
1934 #ifdef __NO_SOFT_SERIAL_INTERRUPT
1935 	int s;
1936 
1937 	s = splsoftserial();
1938 	com_softintr_scheduled = 0;
1939 #endif
1940 
1941 	for (unit = 0; unit < com_cd.cd_ndevs; unit++) {
1942 		sc = device_lookup(&com_cd, unit);
1943 		if (sc == NULL || !ISSET(sc->sc_hwflags, COM_HW_DEV_OK))
1944 			continue;
1945 
1946 		if (COM_ISALIVE(sc) == 0)
1947 			continue;
1948 
1949 		tp = sc->sc_tty;
1950 		if (tp == NULL)
1951 			continue;
1952 		if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0)
1953 			continue;
1954 #endif
1955 		tp = sc->sc_tty;
1956 
1957 		if (sc->sc_rx_ready) {
1958 			sc->sc_rx_ready = 0;
1959 			com_rxsoft(sc, tp);
1960 		}
1961 
1962 		if (sc->sc_st_check) {
1963 			sc->sc_st_check = 0;
1964 			com_stsoft(sc, tp);
1965 		}
1966 
1967 		if (sc->sc_tx_done) {
1968 			sc->sc_tx_done = 0;
1969 			com_txsoft(sc, tp);
1970 		}
1971 	}
1972 
1973 #ifndef __HAVE_GENERIC_SOFT_INTERRUPTS
1974 #ifdef __NO_SOFT_SERIAL_INTERRUPT
1975 	splx(s);
1976 #endif
1977 #endif
1978 }
1979 
1980 #ifdef __ALIGN_BRACKET_LEVEL_FOR_CTAGS
1981 	/* there has got to be a better way to do comsoft() */
1982 }}
1983 #endif
1984 
1985 int
1986 comintr(arg)
1987 	void *arg;
1988 {
1989 	struct com_softc *sc = arg;
1990 	bus_space_tag_t iot = sc->sc_iot;
1991 	bus_space_handle_t ioh = sc->sc_ioh;
1992 	u_char *put, *end;
1993 	u_int cc;
1994 	u_char lsr, iir;
1995 
1996 	if (COM_ISALIVE(sc) == 0)
1997 		return (0);
1998 
1999 	COM_LOCK(sc);
2000 	iir = bus_space_read_1(iot, ioh, com_iir);
2001 	if (ISSET(iir, IIR_NOPEND)) {
2002 		COM_UNLOCK(sc);
2003 		return (0);
2004 	}
2005 
2006 	end = sc->sc_ebuf;
2007 	put = sc->sc_rbput;
2008 	cc = sc->sc_rbavail;
2009 
2010 	do {
2011 		u_char	msr, delta;
2012 
2013 		lsr = bus_space_read_1(iot, ioh, com_lsr);
2014 		if (ISSET(lsr, LSR_BI)) {
2015 			int cn_trapped = 0;
2016 			cn_check_magic(sc->sc_tty->t_dev,
2017 				       CNC_BREAK, com_cnm_state);
2018 			if (cn_trapped)
2019 				continue;
2020 #if defined(KGDB)
2021 			if (ISSET(sc->sc_hwflags, COM_HW_KGDB)) {
2022 				kgdb_connect(1);
2023 				continue;
2024 			}
2025 #endif
2026 		}
2027 
2028 		if (ISSET(lsr, LSR_RCV_MASK) &&
2029 		    !ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
2030 			while (cc > 0) {
2031 				int cn_trapped = 0;
2032 				put[0] = bus_space_read_1(iot, ioh, com_data);
2033 				put[1] = lsr;
2034 				cn_check_magic(sc->sc_tty->t_dev,
2035 					       put[0], com_cnm_state);
2036 				if (cn_trapped) {
2037 					lsr = bus_space_read_1(iot, ioh, com_lsr);
2038 					if (!ISSET(lsr, LSR_RCV_MASK))
2039 						break;
2040 
2041 					continue;
2042 				}
2043 				put += 2;
2044 				if (put >= end)
2045 					put = sc->sc_rbuf;
2046 				cc--;
2047 
2048 				lsr = bus_space_read_1(iot, ioh, com_lsr);
2049 				if (!ISSET(lsr, LSR_RCV_MASK))
2050 					break;
2051 			}
2052 
2053 			/*
2054 			 * Current string of incoming characters ended because
2055 			 * no more data was available or we ran out of space.
2056 			 * Schedule a receive event if any data was received.
2057 			 * If we're out of space, turn off receive interrupts.
2058 			 */
2059 			sc->sc_rbput = put;
2060 			sc->sc_rbavail = cc;
2061 			if (!ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED))
2062 				sc->sc_rx_ready = 1;
2063 
2064 			/*
2065 			 * See if we are in danger of overflowing a buffer. If
2066 			 * so, use hardware flow control to ease the pressure.
2067 			 */
2068 			if (!ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED) &&
2069 			    cc < sc->sc_r_hiwat) {
2070 				SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
2071 				com_hwiflow(sc);
2072 			}
2073 
2074 			/*
2075 			 * If we're out of space, disable receive interrupts
2076 			 * until the queue has drained a bit.
2077 			 */
2078 			if (!cc) {
2079 				SET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
2080 				CLR(sc->sc_ier, IER_ERXRDY);
2081 				bus_space_write_1(iot, ioh, com_ier, sc->sc_ier);
2082 			}
2083 		} else {
2084 			if ((iir & IIR_IMASK) == IIR_RXRDY) {
2085 				bus_space_write_1(iot, ioh, com_ier, 0);
2086 				delay(10);
2087 				bus_space_write_1(iot, ioh, com_ier,sc->sc_ier);
2088 				iir = IIR_NOPEND;
2089 				continue;
2090 			}
2091 		}
2092 
2093 		msr = bus_space_read_1(iot, ioh, com_msr);
2094 		delta = msr ^ sc->sc_msr;
2095 		sc->sc_msr = msr;
2096 		/*
2097 		 * Pulse-per-second (PSS) signals on edge of DCD?
2098 		 * Process these even if line discipline is ignoring DCD.
2099 		 */
2100 		if (delta & sc->sc_ppsmask) {
2101 			struct timeval tv;
2102 		    	if ((msr & sc->sc_ppsmask) == sc->sc_ppsassert) {
2103 				/* XXX nanotime() */
2104 				microtime(&tv);
2105 				TIMEVAL_TO_TIMESPEC(&tv,
2106 				    &sc->ppsinfo.assert_timestamp);
2107 				if (sc->ppsparam.mode & PPS_OFFSETASSERT) {
2108 					timespecadd(&sc->ppsinfo.assert_timestamp,
2109 					    &sc->ppsparam.assert_offset,
2110 						    &sc->ppsinfo.assert_timestamp);
2111 				}
2112 
2113 #ifdef PPS_SYNC
2114 				if (sc->ppsparam.mode & PPS_HARDPPSONASSERT)
2115 					hardpps(&tv, tv.tv_usec);
2116 #endif
2117 				sc->ppsinfo.assert_sequence++;
2118 				sc->ppsinfo.current_mode = sc->ppsparam.mode;
2119 
2120 			} else if ((msr & sc->sc_ppsmask) == sc->sc_ppsclear) {
2121 				/* XXX nanotime() */
2122 				microtime(&tv);
2123 				TIMEVAL_TO_TIMESPEC(&tv,
2124 				    &sc->ppsinfo.clear_timestamp);
2125 				if (sc->ppsparam.mode & PPS_OFFSETCLEAR) {
2126 					timespecadd(&sc->ppsinfo.clear_timestamp,
2127 					    &sc->ppsparam.clear_offset,
2128 					    &sc->ppsinfo.clear_timestamp);
2129 				}
2130 
2131 #ifdef PPS_SYNC
2132 				if (sc->ppsparam.mode & PPS_HARDPPSONCLEAR)
2133 					hardpps(&tv, tv.tv_usec);
2134 #endif
2135 				sc->ppsinfo.clear_sequence++;
2136 				sc->ppsinfo.current_mode = sc->ppsparam.mode;
2137 			}
2138 		}
2139 
2140 		/*
2141 		 * Process normal status changes
2142 		 */
2143 		if (ISSET(delta, sc->sc_msr_mask)) {
2144 			SET(sc->sc_msr_delta, delta);
2145 
2146 			/*
2147 			 * Stop output immediately if we lose the output
2148 			 * flow control signal or carrier detect.
2149 			 */
2150 			if (ISSET(~msr, sc->sc_msr_mask)) {
2151 				sc->sc_tbc = 0;
2152 				sc->sc_heldtbc = 0;
2153 #ifdef COM_DEBUG
2154 				if (com_debug)
2155 					comstatus(sc, "comintr  ");
2156 #endif
2157 			}
2158 
2159 			sc->sc_st_check = 1;
2160 		}
2161 	} while (!ISSET((iir = bus_space_read_1(iot, ioh, com_iir)), IIR_NOPEND));
2162 
2163 	/*
2164 	 * Done handling any receive interrupts. See if data can be
2165 	 * transmitted as well. Schedule tx done event if no data left
2166 	 * and tty was marked busy.
2167 	 */
2168 	if (ISSET(lsr, LSR_TXRDY)) {
2169 		/*
2170 		 * If we've delayed a parameter change, do it now, and restart
2171 		 * output.
2172 		 */
2173 		if (sc->sc_heldchange) {
2174 			com_loadchannelregs(sc);
2175 			sc->sc_heldchange = 0;
2176 			sc->sc_tbc = sc->sc_heldtbc;
2177 			sc->sc_heldtbc = 0;
2178 		}
2179 
2180 		/* Output the next chunk of the contiguous buffer, if any. */
2181 		if (sc->sc_tbc > 0) {
2182 			int n;
2183 
2184 			n = sc->sc_tbc;
2185 			if (n > sc->sc_fifolen)
2186 				n = sc->sc_fifolen;
2187 			bus_space_write_multi_1(iot, ioh, com_data, sc->sc_tba, n);
2188 			sc->sc_tbc -= n;
2189 			sc->sc_tba += n;
2190 		} else {
2191 			/* Disable transmit completion interrupts if necessary. */
2192 			if (ISSET(sc->sc_ier, IER_ETXRDY)) {
2193 				CLR(sc->sc_ier, IER_ETXRDY);
2194 				bus_space_write_1(iot, ioh, com_ier, sc->sc_ier);
2195 			}
2196 			if (sc->sc_tx_busy) {
2197 				sc->sc_tx_busy = 0;
2198 				sc->sc_tx_done = 1;
2199 			}
2200 		}
2201 	}
2202 	COM_UNLOCK(sc);
2203 
2204 	/* Wake up the poller. */
2205 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
2206 	softintr_schedule(sc->sc_si);
2207 #else
2208 #ifndef __NO_SOFT_SERIAL_INTERRUPT
2209 	setsoftserial();
2210 #else
2211 	if (!com_softintr_scheduled) {
2212 		com_softintr_scheduled = 1;
2213 		callout_reset(&comsoft_callout, 1, comsoft, NULL);
2214 	}
2215 #endif
2216 #endif
2217 
2218 #if NRND > 0 && defined(RND_COM)
2219 	rnd_add_uint32(&sc->rnd_source, iir | lsr);
2220 #endif
2221 
2222 	return (1);
2223 }
2224 
2225 /*
2226  * The following functions are polled getc and putc routines, shared
2227  * by the console and kgdb glue.
2228  *
2229  * The read-ahead code is so that you can detect pending in-band
2230  * cn_magic in polled mode while doing output rather than having to
2231  * wait until the kernel decides it needs input.
2232  */
2233 
2234 #define MAX_READAHEAD	20
2235 static int com_readahead[MAX_READAHEAD];
2236 static int com_readaheadcount = 0;
2237 
2238 int
2239 com_common_getc(dev, iot, ioh)
2240 	dev_t dev;
2241 	bus_space_tag_t iot;
2242 	bus_space_handle_t ioh;
2243 {
2244 	int s = splserial();
2245 	u_char stat, c;
2246 
2247 	/* got a character from reading things earlier */
2248 	if (com_readaheadcount > 0) {
2249 		int i;
2250 
2251 		c = com_readahead[0];
2252 		for (i = 1; i < com_readaheadcount; i++) {
2253 			com_readahead[i-1] = com_readahead[i];
2254 		}
2255 		com_readaheadcount--;
2256 		splx(s);
2257 		return (c);
2258 	}
2259 
2260 	/* block until a character becomes available */
2261 	while (!ISSET(stat = bus_space_read_1(iot, ioh, com_lsr), LSR_RXRDY))
2262 		;
2263 
2264 	c = bus_space_read_1(iot, ioh, com_data);
2265 	stat = bus_space_read_1(iot, ioh, com_iir);
2266 	{
2267 		int cn_trapped = 0; /* unused */
2268 #ifdef DDB
2269 		extern int db_active;
2270 		if (!db_active)
2271 #endif
2272 			cn_check_magic(dev, c, com_cnm_state);
2273 	}
2274 	splx(s);
2275 	return (c);
2276 }
2277 
2278 void
2279 com_common_putc(dev, iot, ioh, c)
2280 	dev_t dev;
2281 	bus_space_tag_t iot;
2282 	bus_space_handle_t ioh;
2283 	int c;
2284 {
2285 	int s = splserial();
2286 	int timo;
2287 
2288 	int cin, stat;
2289 	if (com_readaheadcount < MAX_READAHEAD
2290 	     && ISSET(stat = bus_space_read_1(iot, ioh, com_lsr), LSR_RXRDY)) {
2291 		int cn_trapped = 0;
2292 		cin = bus_space_read_1(iot, ioh, com_data);
2293 		stat = bus_space_read_1(iot, ioh, com_iir);
2294 		cn_check_magic(dev, cin, com_cnm_state);
2295 		com_readahead[com_readaheadcount++] = cin;
2296 	}
2297 
2298 	/* wait for any pending transmission to finish */
2299 	timo = 150000;
2300 	while (!ISSET(bus_space_read_1(iot, ioh, com_lsr), LSR_TXRDY) && --timo)
2301 		continue;
2302 
2303 	bus_space_write_1(iot, ioh, com_data, c);
2304 	COM_BARRIER(iot, ioh, BR | BW);
2305 
2306 	/* wait for this transmission to complete */
2307 	timo = 1500000;
2308 	while (!ISSET(bus_space_read_1(iot, ioh, com_lsr), LSR_TXRDY) && --timo)
2309 		continue;
2310 
2311 	splx(s);
2312 }
2313 
2314 /*
2315  * Initialize UART for use as console or KGDB line.
2316  */
2317 int
2318 cominit(iot, iobase, rate, frequency, cflag, iohp)
2319 	bus_space_tag_t iot;
2320 	bus_addr_t iobase;
2321 	int rate, frequency;
2322 	tcflag_t cflag;
2323 	bus_space_handle_t *iohp;
2324 {
2325 	bus_space_handle_t ioh;
2326 
2327 	if (bus_space_map(iot, iobase, COM_NPORTS, 0, &ioh))
2328 		return (ENOMEM); /* ??? */
2329 
2330 	bus_space_write_1(iot, ioh, com_lcr, LCR_EERS);
2331 	bus_space_write_1(iot, ioh, com_efr, 0);
2332 	bus_space_write_1(iot, ioh, com_lcr, LCR_DLAB);
2333 	rate = comspeed(rate, frequency);
2334 	bus_space_write_1(iot, ioh, com_dlbl, rate);
2335 	bus_space_write_1(iot, ioh, com_dlbh, rate >> 8);
2336 	bus_space_write_1(iot, ioh, com_lcr, cflag2lcr(cflag));
2337 	bus_space_write_1(iot, ioh, com_mcr, MCR_DTR | MCR_RTS);
2338 	bus_space_write_1(iot, ioh, com_fifo,
2339 	    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_1);
2340 	bus_space_write_1(iot, ioh, com_ier, 0);
2341 
2342 	*iohp = ioh;
2343 	return (0);
2344 }
2345 
2346 /*
2347  * Following are all routines needed for COM to act as console
2348  */
2349 struct consdev comcons = {
2350 	NULL, NULL, comcngetc, comcnputc, comcnpollc, NULL,
2351 	NODEV, CN_NORMAL
2352 };
2353 
2354 
2355 int
2356 comcnattach(iot, iobase, rate, frequency, cflag)
2357 	bus_space_tag_t iot;
2358 	bus_addr_t iobase;
2359 	int rate, frequency;
2360 	tcflag_t cflag;
2361 {
2362 	int res;
2363 
2364 	res = cominit(iot, iobase, rate, frequency, cflag, &comconsioh);
2365 	if (res)
2366 		return (res);
2367 
2368 	cn_tab = &comcons;
2369 	cn_init_magic(&com_cnm_state);
2370 	cn_set_magic("\047\001"); /* default magic is BREAK */
2371 
2372 	comconstag = iot;
2373 	comconsaddr = iobase;
2374 	comconsrate = rate;
2375 	comconscflag = cflag;
2376 
2377 	return (0);
2378 }
2379 
2380 int
2381 comcngetc(dev)
2382 	dev_t dev;
2383 {
2384 	return (com_common_getc(dev, comconstag, comconsioh));
2385 }
2386 
2387 /*
2388  * Console kernel output character routine.
2389  */
2390 void
2391 comcnputc(dev, c)
2392 	dev_t dev;
2393 	int c;
2394 {
2395 	com_common_putc(dev, comconstag, comconsioh, c);
2396 }
2397 
2398 void
2399 comcnpollc(dev, on)
2400 	dev_t dev;
2401 	int on;
2402 {
2403 
2404 }
2405 
2406 #ifdef KGDB
2407 int
2408 com_kgdb_attach(iot, iobase, rate, frequency, cflag)
2409 	bus_space_tag_t iot;
2410 	bus_addr_t iobase;
2411 	int rate, frequency;
2412 	tcflag_t cflag;
2413 {
2414 	int res;
2415 
2416 	if (iot == comconstag && iobase == comconsaddr)
2417 		return (EBUSY); /* cannot share with console */
2418 
2419 	res = cominit(iot, iobase, rate, frequency, cflag, &com_kgdb_ioh);
2420 	if (res)
2421 		return (res);
2422 
2423 	kgdb_attach(com_kgdb_getc, com_kgdb_putc, NULL);
2424 	kgdb_dev = 123; /* unneeded, only to satisfy some tests */
2425 
2426 	com_kgdb_iot = iot;
2427 	com_kgdb_addr = iobase;
2428 
2429 	return (0);
2430 }
2431 
2432 /* ARGSUSED */
2433 int
2434 com_kgdb_getc(arg)
2435 	void *arg;
2436 {
2437 	return (com_common_getc(NODEV, com_kgdb_iot, com_kgdb_ioh));
2438 }
2439 
2440 /* ARGSUSED */
2441 void
2442 com_kgdb_putc(arg, c)
2443 	void *arg;
2444 	int c;
2445 {
2446 	com_common_putc(NODEV, com_kgdb_iot, com_kgdb_ioh, c);
2447 }
2448 #endif /* KGDB */
2449 
2450 /* helper function to identify the com ports used by
2451  console or KGDB (and not yet autoconf attached) */
2452 int
2453 com_is_console(iot, iobase, ioh)
2454 	bus_space_tag_t iot;
2455 	bus_addr_t iobase;
2456 	bus_space_handle_t *ioh;
2457 {
2458 	bus_space_handle_t help;
2459 
2460 	if (!comconsattached &&
2461 	    iot == comconstag && iobase == comconsaddr)
2462 		help = comconsioh;
2463 #ifdef KGDB
2464 	else if (!com_kgdb_attached &&
2465 	    iot == com_kgdb_iot && iobase == com_kgdb_addr)
2466 		help = com_kgdb_ioh;
2467 #endif
2468 	else
2469 		return (0);
2470 
2471 	if (ioh)
2472 		*ioh = help;
2473 	return (1);
2474 }
2475