xref: /openbsd-src/sys/dev/ic/com.c (revision f2da64fbbbf1b03f09f390ab01267c93dfd77c4c)
1 /*	$OpenBSD: com.c,v 1.161 2016/09/04 18:20:34 tedu Exp $	*/
2 /*	$NetBSD: com.c,v 1.82.4.1 1996/06/02 09:08:00 mrg Exp $	*/
3 
4 /*
5  * Copyright (c) 1997 - 1999, Jason Downs.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS
17  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
18  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
19  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT,
20  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
21  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
22  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
23  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 /*-
29  * Copyright (c) 1993, 1994, 1995, 1996
30  *	Charles M. Hannum.  All rights reserved.
31  * Copyright (c) 1991 The Regents of the University of California.
32  * All rights reserved.
33  *
34  * Redistribution and use in source and binary forms, with or without
35  * modification, are permitted provided that the following conditions
36  * are met:
37  * 1. Redistributions of source code must retain the above copyright
38  *    notice, this list of conditions and the following disclaimer.
39  * 2. Redistributions in binary form must reproduce the above copyright
40  *    notice, this list of conditions and the following disclaimer in the
41  *    documentation and/or other materials provided with the distribution.
42  * 3. Neither the name of the University nor the names of its contributors
43  *    may be used to endorse or promote products derived from this software
44  *    without specific prior written permission.
45  *
46  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
47  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
48  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
49  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
50  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
51  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
52  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
53  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
54  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
55  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
56  * SUCH DAMAGE.
57  *
58  *	@(#)com.c	7.5 (Berkeley) 5/16/91
59  */
60 
61 /*
62  * COM driver, based on HP dca driver
63  * uses National Semiconductor NS16450/NS16550AF UART
64  */
65 #include <sys/param.h>
66 #include <sys/systm.h>
67 #include <sys/ioctl.h>
68 #include <sys/selinfo.h>
69 #include <sys/tty.h>
70 #include <sys/conf.h>
71 #include <sys/file.h>
72 #include <sys/uio.h>
73 #include <sys/kernel.h>
74 #include <sys/syslog.h>
75 #include <sys/device.h>
76 #include <sys/vnode.h>
77 #ifdef DDB
78 #include <ddb/db_var.h>
79 #endif
80 
81 #include <machine/bus.h>
82 #include <machine/intr.h>
83 
84 #define	COM_CONSOLE
85 #include <dev/cons.h>
86 
87 #include <dev/ic/comreg.h>
88 #include <dev/ic/comvar.h>
89 #include <dev/ic/ns16550reg.h>
90 #define	com_lcr	com_cfcr
91 
92 cdev_decl(com);
93 
94 static u_char tiocm_xxx2mcr(int);
95 
96 void	compwroff(struct com_softc *);
97 void	cominit(bus_space_tag_t, bus_space_handle_t, int, int);
98 int	com_is_console(bus_space_tag_t, bus_addr_t);
99 
100 struct cfdriver com_cd = {
101 	NULL, "com", DV_TTY
102 };
103 
104 int	comdefaultrate = TTYDEF_SPEED;
105 #ifdef COM_CONSOLE
106 int	comconsfreq;
107 int	comconsrate = TTYDEF_SPEED;
108 bus_addr_t comconsaddr = 0;
109 int	comconsattached;
110 bus_space_tag_t comconsiot;
111 bus_space_handle_t comconsioh;
112 int	comconsunit;
113 tcflag_t comconscflag = TTYDEF_CFLAG;
114 #endif
115 
116 int	commajor;
117 
118 #ifdef KGDB
119 #include <sys/kgdb.h>
120 
121 bus_addr_t com_kgdb_addr;
122 bus_space_tag_t com_kgdb_iot;
123 bus_space_handle_t com_kgdb_ioh;
124 
125 int    com_kgdb_getc(void *);
126 void   com_kgdb_putc(void *, int);
127 #endif /* KGDB */
128 
129 #define	DEVUNIT(x)	(minor(x) & 0x7f)
130 #define	DEVCUA(x)	(minor(x) & 0x80)
131 
132 int
133 comspeed(long freq, long speed)
134 {
135 #define	divrnd(n, q)	(((n)*2/(q)+1)/2)	/* divide and round off */
136 
137 	int x, err;
138 
139 	if (speed == 0)
140 		return 0;
141 	if (speed < 0)
142 		return -1;
143 	x = divrnd((freq / 16), speed);
144 	if (x <= 0)
145 		return -1;
146 	err = divrnd((quad_t)freq * 1000 / 16, speed * x) - 1000;
147 	if (err < 0)
148 		err = -err;
149 	if (err > COM_TOLERANCE)
150 		return -1;
151 	return x;
152 
153 #undef	divrnd
154 }
155 
156 #ifdef COM_CONSOLE
157 int
158 comprobe1(bus_space_tag_t iot, bus_space_handle_t ioh)
159 {
160 	int i, k;
161 
162 	/* force access to id reg */
163 	bus_space_write_1(iot, ioh, com_lcr, 0);
164 	bus_space_write_1(iot, ioh, com_iir, 0);
165 	for (i = 0; i < 32; i++) {
166 		k = bus_space_read_1(iot, ioh, com_iir);
167 		if (k & 0x38) {
168 			bus_space_read_1(iot, ioh, com_data); /* cleanup */
169 		} else
170 			break;
171 	}
172 	if (i >= 32)
173 		return 0;
174 
175 	return 1;
176 }
177 #endif
178 
179 int
180 com_detach(struct device *self, int flags)
181 {
182 	struct com_softc *sc = (struct com_softc *)self;
183 	int maj, mn;
184 
185 	sc->sc_swflags |= COM_SW_DEAD;
186 
187 	/* Locate the major number. */
188 	for (maj = 0; maj < nchrdev; maj++)
189 		if (cdevsw[maj].d_open == comopen)
190 			break;
191 
192 	/* Nuke the vnodes for any open instances. */
193 	mn = self->dv_unit;
194 	vdevgone(maj, mn, mn, VCHR);
195 
196 	/* XXX a symbolic constant for the cua bit would be nicer. */
197 	mn |= 0x80;
198 	vdevgone(maj, mn, mn, VCHR);
199 
200 	/* Detach and free the tty. */
201 	if (sc->sc_tty) {
202 		ttyfree(sc->sc_tty);
203 	}
204 
205 	timeout_del(&sc->sc_dtr_tmo);
206 	timeout_del(&sc->sc_diag_tmo);
207 	softintr_disestablish(sc->sc_si);
208 
209 	return (0);
210 }
211 
212 int
213 com_activate(struct device *self, int act)
214 {
215 	struct com_softc *sc = (struct com_softc *)self;
216 	int s, rv = 0;
217 
218 	switch (act) {
219 	case DVACT_SUSPEND:
220 		if (timeout_del(&sc->sc_dtr_tmo)) {
221 			/* Make sure DTR gets raised upon resume. */
222 			SET(sc->sc_mcr, MCR_DTR | MCR_RTS);
223 		}
224 		timeout_del(&sc->sc_diag_tmo);
225 		break;
226 	case DVACT_RESUME:
227 		com_resume(sc);
228 		break;
229 	case DVACT_DEACTIVATE:
230 #ifdef KGDB
231 		if (sc->sc_hwflags & (COM_HW_CONSOLE|COM_HW_KGDB)) {
232 #else
233 		if (sc->sc_hwflags & COM_HW_CONSOLE) {
234 #endif /* KGDB */
235 			rv = EBUSY;
236 			break;
237 		}
238 
239 		s = spltty();
240 		if (sc->disable != NULL && sc->enabled != 0) {
241 			(*sc->disable)(sc);
242 			sc->enabled = 0;
243 		}
244 		splx(s);
245 		break;
246 	}
247 	return (rv);
248 }
249 
250 int
251 comopen(dev_t dev, int flag, int mode, struct proc *p)
252 {
253 	int unit = DEVUNIT(dev);
254 	struct com_softc *sc;
255 	bus_space_tag_t iot;
256 	bus_space_handle_t ioh;
257 	struct tty *tp;
258 	int s;
259 	int error = 0;
260 
261 	if (unit >= com_cd.cd_ndevs)
262 		return ENXIO;
263 	sc = com_cd.cd_devs[unit];
264 	if (!sc)
265 		return ENXIO;
266 
267 #ifdef KGDB
268 	/*
269 	 * If this is the kgdb port, no other use is permitted.
270 	 */
271 	if (ISSET(sc->sc_hwflags, COM_HW_KGDB))
272 		return (EBUSY);
273 #endif /* KGDB */
274 
275 	s = spltty();
276 	if (!sc->sc_tty) {
277 		tp = sc->sc_tty = ttymalloc(1000000);
278 	} else
279 		tp = sc->sc_tty;
280 	splx(s);
281 
282 	tp->t_oproc = comstart;
283 	tp->t_param = comparam;
284 	tp->t_dev = dev;
285 	if (!ISSET(tp->t_state, TS_ISOPEN)) {
286 		SET(tp->t_state, TS_WOPEN);
287 		ttychars(tp);
288 		tp->t_iflag = TTYDEF_IFLAG;
289 		tp->t_oflag = TTYDEF_OFLAG;
290 #ifdef COM_CONSOLE
291 		if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
292 			tp->t_cflag = comconscflag;
293 			tp->t_ispeed = tp->t_ospeed = comconsrate;
294 		} else
295 #endif
296 		{
297 			tp->t_cflag = TTYDEF_CFLAG;
298 			tp->t_ispeed = tp->t_ospeed = comdefaultrate;
299 		}
300 		if (ISSET(sc->sc_swflags, COM_SW_CLOCAL))
301 			SET(tp->t_cflag, CLOCAL);
302 		if (ISSET(sc->sc_swflags, COM_SW_CRTSCTS))
303 			SET(tp->t_cflag, CRTSCTS);
304 		if (ISSET(sc->sc_swflags, COM_SW_MDMBUF))
305 			SET(tp->t_cflag, MDMBUF);
306 		tp->t_lflag = TTYDEF_LFLAG;
307 
308 		s = spltty();
309 
310 		sc->sc_initialize = 1;
311 		comparam(tp, &tp->t_termios);
312 		ttsetwater(tp);
313 
314 		sc->sc_ibufp = sc->sc_ibuf = sc->sc_ibufs[0];
315 		sc->sc_ibufhigh = sc->sc_ibuf + COM_IHIGHWATER;
316 		sc->sc_ibufend = sc->sc_ibuf + COM_IBUFSIZE;
317 
318 		iot = sc->sc_iot;
319 		ioh = sc->sc_ioh;
320 
321 		/*
322 		 * Wake up the sleepy heads.
323 		 */
324 		if (!ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
325 			switch (sc->sc_uarttype) {
326 			case COM_UART_ST16650:
327 			case COM_UART_ST16650V2:
328 				bus_space_write_1(iot, ioh, com_lcr, LCR_EFR);
329 				bus_space_write_1(iot, ioh, com_efr, EFR_ECB);
330 				bus_space_write_1(iot, ioh, com_ier, 0);
331 				bus_space_write_1(iot, ioh, com_efr, 0);
332 				bus_space_write_1(iot, ioh, com_lcr, 0);
333 				break;
334 			case COM_UART_TI16750:
335 				bus_space_write_1(iot, ioh, com_ier, 0);
336 				break;
337 			}
338 		}
339 
340 		if (ISSET(sc->sc_hwflags, COM_HW_FIFO)) {
341 			u_int8_t fifo = FIFO_ENABLE|FIFO_RCV_RST|FIFO_XMT_RST;
342 			u_int8_t lcr;
343 
344 			if (tp->t_ispeed <= 1200)
345 				fifo |= FIFO_TRIGGER_1;
346 			else if (tp->t_ispeed <= 38400)
347 				fifo |= FIFO_TRIGGER_4;
348 			else
349 				fifo |= FIFO_TRIGGER_8;
350 			if (sc->sc_uarttype == COM_UART_TI16750) {
351 				fifo |= FIFO_ENABLE_64BYTE;
352 				lcr = bus_space_read_1(iot, ioh, com_lcr);
353 				bus_space_write_1(iot, ioh, com_lcr,
354 				    lcr | LCR_DLAB);
355 			}
356 
357 			/*
358 			 * (Re)enable and drain FIFOs.
359 			 *
360 			 * Certain SMC chips cause problems if the FIFOs are
361 			 * enabled while input is ready. Turn off the FIFO
362 			 * if necessary to clear the input. Test the input
363 			 * ready bit after enabling the FIFOs to handle races
364 			 * between enabling and fresh input.
365 			 *
366 			 * Set the FIFO threshold based on the receive speed.
367 			 */
368 			for (;;) {
369 				bus_space_write_1(iot, ioh, com_fifo, 0);
370 				delay(100);
371 				(void) bus_space_read_1(iot, ioh, com_data);
372 				bus_space_write_1(iot, ioh, com_fifo, fifo |
373 				    FIFO_RCV_RST | FIFO_XMT_RST);
374 				delay(100);
375 				if(!ISSET(bus_space_read_1(iot, ioh,
376 				    com_lsr), LSR_RXRDY))
377 					break;
378 			}
379 			if (sc->sc_uarttype == COM_UART_TI16750)
380 				bus_space_write_1(iot, ioh, com_lcr, lcr);
381 		}
382 
383 		/* Flush any pending I/O. */
384 		while (ISSET(bus_space_read_1(iot, ioh, com_lsr), LSR_RXRDY))
385 			(void) bus_space_read_1(iot, ioh, com_data);
386 
387 		/* You turn me on, baby! */
388 		sc->sc_mcr = MCR_DTR | MCR_RTS;
389 		if (!ISSET(sc->sc_hwflags, COM_HW_NOIEN))
390 			SET(sc->sc_mcr, MCR_IENABLE);
391 		bus_space_write_1(iot, ioh, com_mcr, sc->sc_mcr);
392 		sc->sc_ier = IER_ERXRDY | IER_ERLS | IER_EMSC;
393 		bus_space_write_1(iot, ioh, com_ier, sc->sc_ier);
394 
395 		sc->sc_msr = bus_space_read_1(iot, ioh, com_msr);
396 		if (ISSET(sc->sc_swflags, COM_SW_SOFTCAR) || DEVCUA(dev) ||
397 		    ISSET(sc->sc_msr, MSR_DCD) || ISSET(tp->t_cflag, MDMBUF))
398 			SET(tp->t_state, TS_CARR_ON);
399 		else
400 			CLR(tp->t_state, TS_CARR_ON);
401 	} else if (ISSET(tp->t_state, TS_XCLUDE) && suser(p, 0) != 0)
402 		return EBUSY;
403 	else
404 		s = spltty();
405 
406 	if (DEVCUA(dev)) {
407 		if (ISSET(tp->t_state, TS_ISOPEN)) {
408 			/* Ah, but someone already is dialed in... */
409 			splx(s);
410 			return EBUSY;
411 		}
412 		sc->sc_cua = 1;		/* We go into CUA mode. */
413 	} else {
414 		/* tty (not cua) device; wait for carrier if necessary. */
415 		if (ISSET(flag, O_NONBLOCK)) {
416 			if (sc->sc_cua) {
417 				/* Opening TTY non-blocking... but the CUA is busy. */
418 				splx(s);
419 				return EBUSY;
420 			}
421 		} else {
422 			while (sc->sc_cua ||
423 			    (!ISSET(tp->t_cflag, CLOCAL) &&
424 				!ISSET(tp->t_state, TS_CARR_ON))) {
425 				SET(tp->t_state, TS_WOPEN);
426 				error = ttysleep(tp, &tp->t_rawq, TTIPRI | PCATCH, ttopen, 0);
427 				/*
428 				 * If TS_WOPEN has been reset, that means the cua device
429 				 * has been closed.  We don't want to fail in that case,
430 				 * so just go around again.
431 				 */
432 				if (error && ISSET(tp->t_state, TS_WOPEN)) {
433 					CLR(tp->t_state, TS_WOPEN);
434 					if (!sc->sc_cua && !ISSET(tp->t_state, TS_ISOPEN))
435 						compwroff(sc);
436 					splx(s);
437 					return error;
438 				}
439 			}
440 		}
441 	}
442 	splx(s);
443 
444 	return (*linesw[tp->t_line].l_open)(dev, tp, p);
445 }
446 
447 int
448 comclose(dev_t dev, int flag, int mode, struct proc *p)
449 {
450 	int unit = DEVUNIT(dev);
451 	struct com_softc *sc = com_cd.cd_devs[unit];
452 	bus_space_tag_t iot = sc->sc_iot;
453 	bus_space_handle_t ioh = sc->sc_ioh;
454 	struct tty *tp = sc->sc_tty;
455 	int s;
456 
457 #ifdef COM_CONSOLE
458 	/* XXX This is for cons.c. */
459 	if (!ISSET(tp->t_state, TS_ISOPEN))
460 		return 0;
461 #endif
462 
463 	if(sc->sc_swflags & COM_SW_DEAD)
464 		return 0;
465 
466 	(*linesw[tp->t_line].l_close)(tp, flag, p);
467 	s = spltty();
468 	if (ISSET(tp->t_state, TS_WOPEN)) {
469 		/* tty device is waiting for carrier; drop dtr then re-raise */
470 		CLR(sc->sc_mcr, MCR_DTR | MCR_RTS);
471 		bus_space_write_1(iot, ioh, com_mcr, sc->sc_mcr);
472 		timeout_add_sec(&sc->sc_dtr_tmo, 2);
473 	} else {
474 		/* no one else waiting; turn off the uart */
475 		compwroff(sc);
476 	}
477 	CLR(tp->t_state, TS_BUSY | TS_FLUSH);
478 	sc->sc_cua = 0;
479 	splx(s);
480 	ttyclose(tp);
481 
482 #ifdef COM_CONSOLE
483 #ifdef notyet /* XXXX */
484 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
485 		ttyfree(tp);
486 		sc->sc_tty = 0;
487 	}
488 #endif
489 #endif
490 	return 0;
491 }
492 
493 void
494 compwroff(struct com_softc *sc)
495 {
496 	bus_space_tag_t iot = sc->sc_iot;
497 	bus_space_handle_t ioh = sc->sc_ioh;
498 	struct tty *tp = sc->sc_tty;
499 
500 	CLR(sc->sc_lcr, LCR_SBREAK);
501 	bus_space_write_1(iot, ioh, com_lcr, sc->sc_lcr);
502 	bus_space_write_1(iot, ioh, com_ier, 0);
503 	if (ISSET(tp->t_cflag, HUPCL) &&
504 	    !ISSET(sc->sc_swflags, COM_SW_SOFTCAR)) {
505 		/* XXX perhaps only clear DTR */
506 		sc->sc_mcr = 0;
507 		bus_space_write_1(iot, ioh, com_mcr, sc->sc_mcr);
508 	}
509 
510 	/*
511 	 * Turn FIFO off; enter sleep mode if possible.
512 	 */
513 	bus_space_write_1(iot, ioh, com_fifo, 0);
514 	delay(100);
515 	if (ISSET(bus_space_read_1(iot, ioh, com_lsr), LSR_RXRDY))
516 		(void) bus_space_read_1(iot, ioh, com_data);
517 	delay(100);
518 	bus_space_write_1(iot, ioh, com_fifo,
519 			  FIFO_RCV_RST | FIFO_XMT_RST);
520 
521 	if (!ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
522 		switch (sc->sc_uarttype) {
523 		case COM_UART_ST16650:
524 		case COM_UART_ST16650V2:
525 			bus_space_write_1(iot, ioh, com_lcr, LCR_EFR);
526 			bus_space_write_1(iot, ioh, com_efr, EFR_ECB);
527 			bus_space_write_1(iot, ioh, com_ier, IER_SLEEP);
528 			bus_space_write_1(iot, ioh, com_lcr, 0);
529 			break;
530 		case COM_UART_TI16750:
531 			bus_space_write_1(iot, ioh, com_ier, IER_SLEEP);
532 			break;
533 		}
534 	}
535 }
536 
537 void
538 com_resume(struct com_softc *sc)
539 {
540 	struct tty *tp = sc->sc_tty;
541 	bus_space_tag_t iot = sc->sc_iot;
542 	bus_space_handle_t ioh = sc->sc_ioh;
543 	int ospeed;
544 
545 	if (!tp || !ISSET(tp->t_state, TS_ISOPEN)) {
546 #ifdef COM_CONSOLE
547 		if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE))
548 			cominit(iot, ioh, comconsrate, comconsfreq);
549 #endif
550 		return;
551 	}
552 
553 	/*
554 	 * Wake up the sleepy heads.
555 	 */
556 	if (!ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
557 		switch (sc->sc_uarttype) {
558 		case COM_UART_ST16650:
559 		case COM_UART_ST16650V2:
560 			bus_space_write_1(iot, ioh, com_lcr, LCR_EFR);
561 			bus_space_write_1(iot, ioh, com_efr, EFR_ECB);
562 			bus_space_write_1(iot, ioh, com_ier, 0);
563 			bus_space_write_1(iot, ioh, com_efr, 0);
564 			bus_space_write_1(iot, ioh, com_lcr, 0);
565 			break;
566 		case COM_UART_TI16750:
567 			bus_space_write_1(iot, ioh, com_ier, 0);
568 			break;
569 		}
570 	}
571 
572 	ospeed = comspeed(sc->sc_frequency, tp->t_ospeed);
573 
574 	if (ospeed != 0) {
575 		bus_space_write_1(iot, ioh, com_lcr, sc->sc_lcr | LCR_DLAB);
576 		bus_space_write_1(iot, ioh, com_dlbl, ospeed);
577 		bus_space_write_1(iot, ioh, com_dlbh, ospeed >> 8);
578 		bus_space_write_1(iot, ioh, com_lcr, sc->sc_lcr);
579 	} else {
580 		bus_space_write_1(iot, ioh, com_lcr, sc->sc_lcr);
581 	}
582 
583 	if (ISSET(sc->sc_hwflags, COM_HW_FIFO)) {
584 		u_int8_t fifo = FIFO_ENABLE|FIFO_RCV_RST|FIFO_XMT_RST;
585 		u_int8_t lcr;
586 
587 		if (tp->t_ispeed <= 1200)
588 			fifo |= FIFO_TRIGGER_1;
589 		else if (tp->t_ispeed <= 38400)
590 			fifo |= FIFO_TRIGGER_4;
591 		else
592 			fifo |= FIFO_TRIGGER_8;
593 		if (sc->sc_uarttype == COM_UART_TI16750) {
594 			fifo |= FIFO_ENABLE_64BYTE;
595 			lcr = bus_space_read_1(iot, ioh, com_lcr);
596 			bus_space_write_1(iot, ioh, com_lcr,
597 			    lcr | LCR_DLAB);
598 		}
599 
600 		/*
601 		 * (Re)enable and drain FIFOs.
602 		 *
603 		 * Certain SMC chips cause problems if the FIFOs are
604 		 * enabled while input is ready. Turn off the FIFO
605 		 * if necessary to clear the input. Test the input
606 		 * ready bit after enabling the FIFOs to handle races
607 		 * between enabling and fresh input.
608 		 *
609 		 * Set the FIFO threshold based on the receive speed.
610 		 */
611 		for (;;) {
612 			bus_space_write_1(iot, ioh, com_fifo, 0);
613 			delay(100);
614 			(void) bus_space_read_1(iot, ioh, com_data);
615 			bus_space_write_1(iot, ioh, com_fifo, fifo |
616 			    FIFO_RCV_RST | FIFO_XMT_RST);
617 			delay(100);
618 			if(!ISSET(bus_space_read_1(iot, ioh,
619 			    com_lsr), LSR_RXRDY))
620 				break;
621 		}
622 		if (sc->sc_uarttype == COM_UART_TI16750)
623 			bus_space_write_1(iot, ioh, com_lcr, lcr);
624 	}
625 
626 	/* You turn me on, baby! */
627 	bus_space_write_1(iot, ioh, com_mcr, sc->sc_mcr);
628 	bus_space_write_1(iot, ioh, com_ier, sc->sc_ier);
629 }
630 
631 void
632 com_raisedtr(void *arg)
633 {
634 	struct com_softc *sc = arg;
635 
636 	SET(sc->sc_mcr, MCR_DTR | MCR_RTS);
637 	bus_space_write_1(sc->sc_iot, sc->sc_ioh, com_mcr, sc->sc_mcr);
638 }
639 
640 int
641 comread(dev_t dev, struct uio *uio, int flag)
642 {
643 	struct com_softc *sc = com_cd.cd_devs[DEVUNIT(dev)];
644 	struct tty *tp = sc->sc_tty;
645 
646 	return ((*linesw[tp->t_line].l_read)(tp, uio, flag));
647 }
648 
649 int
650 comwrite(dev_t dev, struct uio *uio, int flag)
651 {
652 	struct com_softc *sc = com_cd.cd_devs[DEVUNIT(dev)];
653 	struct tty *tp = sc->sc_tty;
654 
655 	return ((*linesw[tp->t_line].l_write)(tp, uio, flag));
656 }
657 
658 struct tty *
659 comtty(dev_t dev)
660 {
661 	struct com_softc *sc = com_cd.cd_devs[DEVUNIT(dev)];
662 	struct tty *tp = sc->sc_tty;
663 
664 	return (tp);
665 }
666 
667 static u_char
668 tiocm_xxx2mcr(int data)
669 {
670 	u_char m = 0;
671 
672 	if (ISSET(data, TIOCM_DTR))
673 		SET(m, MCR_DTR);
674 	if (ISSET(data, TIOCM_RTS))
675 		SET(m, MCR_RTS);
676 	return m;
677 }
678 
679 int
680 comioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct proc *p)
681 {
682 	int unit = DEVUNIT(dev);
683 	struct com_softc *sc = com_cd.cd_devs[unit];
684 	struct tty *tp = sc->sc_tty;
685 	bus_space_tag_t iot = sc->sc_iot;
686 	bus_space_handle_t ioh = sc->sc_ioh;
687 	int error;
688 
689 	error = (*linesw[tp->t_line].l_ioctl)(tp, cmd, data, flag, p);
690 	if (error >= 0)
691 		return error;
692 	error = ttioctl(tp, cmd, data, flag, p);
693 	if (error >= 0)
694 		return error;
695 
696 	switch (cmd) {
697 	case TIOCSBRK:
698 		SET(sc->sc_lcr, LCR_SBREAK);
699 		bus_space_write_1(iot, ioh, com_lcr, sc->sc_lcr);
700 		break;
701 	case TIOCCBRK:
702 		CLR(sc->sc_lcr, LCR_SBREAK);
703 		bus_space_write_1(iot, ioh, com_lcr, sc->sc_lcr);
704 		break;
705 	case TIOCSDTR:
706 		SET(sc->sc_mcr, sc->sc_dtr);
707 		bus_space_write_1(iot, ioh, com_mcr, sc->sc_mcr);
708 		break;
709 	case TIOCCDTR:
710 		CLR(sc->sc_mcr, sc->sc_dtr);
711 		bus_space_write_1(iot, ioh, com_mcr, sc->sc_mcr);
712 		break;
713 	case TIOCMSET:
714 		CLR(sc->sc_mcr, MCR_DTR | MCR_RTS);
715 	case TIOCMBIS:
716 		SET(sc->sc_mcr, tiocm_xxx2mcr(*(int *)data));
717 		bus_space_write_1(iot, ioh, com_mcr, sc->sc_mcr);
718 		break;
719 	case TIOCMBIC:
720 		CLR(sc->sc_mcr, tiocm_xxx2mcr(*(int *)data));
721 		bus_space_write_1(iot, ioh, com_mcr, sc->sc_mcr);
722 		break;
723 	case TIOCMGET: {
724 		u_char m;
725 		int bits = 0;
726 
727 		m = sc->sc_mcr;
728 		if (ISSET(m, MCR_DTR))
729 			SET(bits, TIOCM_DTR);
730 		if (ISSET(m, MCR_RTS))
731 			SET(bits, TIOCM_RTS);
732 		m = sc->sc_msr;
733 		if (ISSET(m, MSR_DCD))
734 			SET(bits, TIOCM_CD);
735 		if (ISSET(m, MSR_CTS))
736 			SET(bits, TIOCM_CTS);
737 		if (ISSET(m, MSR_DSR))
738 			SET(bits, TIOCM_DSR);
739 		if (ISSET(m, MSR_RI | MSR_TERI))
740 			SET(bits, TIOCM_RI);
741 		if (bus_space_read_1(iot, ioh, com_ier))
742 			SET(bits, TIOCM_LE);
743 		*(int *)data = bits;
744 		break;
745 	}
746 	case TIOCGFLAGS: {
747 		int driverbits, userbits = 0;
748 
749 		driverbits = sc->sc_swflags;
750 		if (ISSET(driverbits, COM_SW_SOFTCAR))
751 			SET(userbits, TIOCFLAG_SOFTCAR);
752 		if (ISSET(driverbits, COM_SW_CLOCAL))
753 			SET(userbits, TIOCFLAG_CLOCAL);
754 		if (ISSET(driverbits, COM_SW_CRTSCTS))
755 			SET(userbits, TIOCFLAG_CRTSCTS);
756 		if (ISSET(driverbits, COM_SW_MDMBUF))
757 			SET(userbits, TIOCFLAG_MDMBUF);
758 		if (ISSET(driverbits, COM_SW_PPS))
759 			SET(userbits, TIOCFLAG_PPS);
760 
761 		*(int *)data = userbits;
762 		break;
763 	}
764 	case TIOCSFLAGS: {
765 		int userbits, driverbits = 0;
766 
767 		error = suser(p, 0);
768 		if (error != 0)
769 			return(EPERM);
770 
771 		userbits = *(int *)data;
772 		if (ISSET(userbits, TIOCFLAG_SOFTCAR) ||
773 		    ISSET(sc->sc_hwflags, COM_HW_CONSOLE))
774 			SET(driverbits, COM_SW_SOFTCAR);
775 		if (ISSET(userbits, TIOCFLAG_CLOCAL))
776 			SET(driverbits, COM_SW_CLOCAL);
777 		if (ISSET(userbits, TIOCFLAG_CRTSCTS))
778 			SET(driverbits, COM_SW_CRTSCTS);
779 		if (ISSET(userbits, TIOCFLAG_MDMBUF))
780 			SET(driverbits, COM_SW_MDMBUF);
781 		if (ISSET(userbits, TIOCFLAG_PPS))
782 			SET(driverbits, COM_SW_PPS);
783 
784 		sc->sc_swflags = driverbits;
785 		break;
786 	}
787 	default:
788 		return ENOTTY;
789 	}
790 
791 	return 0;
792 }
793 
794 /* already called at spltty */
795 int
796 comparam(struct tty *tp, struct termios *t)
797 {
798 	struct com_softc *sc = com_cd.cd_devs[DEVUNIT(tp->t_dev)];
799 	bus_space_tag_t iot = sc->sc_iot;
800 	bus_space_handle_t ioh = sc->sc_ioh;
801 	int ospeed = comspeed(sc->sc_frequency, t->c_ospeed);
802 	u_char lcr;
803 	tcflag_t oldcflag;
804 
805 	/* Check requested parameters. */
806 	if (ospeed < 0 || (t->c_ispeed && t->c_ispeed != t->c_ospeed))
807 		return EINVAL;
808 
809 	lcr = ISSET(sc->sc_lcr, LCR_SBREAK);
810 
811 	switch (ISSET(t->c_cflag, CSIZE)) {
812 	case CS5:
813 		SET(lcr, LCR_5BITS);
814 		break;
815 	case CS6:
816 		SET(lcr, LCR_6BITS);
817 		break;
818 	case CS7:
819 		SET(lcr, LCR_7BITS);
820 		break;
821 	case CS8:
822 		SET(lcr, LCR_8BITS);
823 		break;
824 	}
825 	if (ISSET(t->c_cflag, PARENB)) {
826 		SET(lcr, LCR_PENAB);
827 		if (!ISSET(t->c_cflag, PARODD))
828 			SET(lcr, LCR_PEVEN);
829 	}
830 	if (ISSET(t->c_cflag, CSTOPB))
831 		SET(lcr, LCR_STOPB);
832 
833 	sc->sc_lcr = lcr;
834 
835 	if (ospeed == 0) {
836 		CLR(sc->sc_mcr, MCR_DTR);
837 		bus_space_write_1(iot, ioh, com_mcr, sc->sc_mcr);
838 	}
839 
840 	/*
841 	 * Set the FIFO threshold based on the receive speed, if we are
842 	 * changing it.
843 	 */
844 	if (sc->sc_initialize || (tp->t_ispeed != t->c_ispeed)) {
845 		sc->sc_initialize = 0;
846 
847 		if (ospeed != 0) {
848 			/*
849 			 * Make sure the transmit FIFO is empty before
850 			 * proceeding.  If we don't do this, some revisions
851 			 * of the UART will hang.  Interestingly enough,
852 			 * even if we do this while the last character is
853 			 * still being pushed out, they don't hang.  This
854 			 * seems good enough.
855 			 */
856 			while (ISSET(tp->t_state, TS_BUSY)) {
857 				int error;
858 
859 				++sc->sc_halt;
860 				error = ttysleep(tp, &tp->t_outq,
861 				    TTOPRI | PCATCH, "comprm", 0);
862 				--sc->sc_halt;
863 				if (error) {
864 					comstart(tp);
865 					return (error);
866 				}
867 			}
868 
869 			bus_space_write_1(iot, ioh, com_lcr, lcr | LCR_DLAB);
870 			bus_space_write_1(iot, ioh, com_dlbl, ospeed);
871 			bus_space_write_1(iot, ioh, com_dlbh, ospeed >> 8);
872 			bus_space_write_1(iot, ioh, com_lcr, lcr);
873 			SET(sc->sc_mcr, MCR_DTR);
874 			bus_space_write_1(iot, ioh, com_mcr, sc->sc_mcr);
875 		} else
876 			bus_space_write_1(iot, ioh, com_lcr, lcr);
877 
878 		if (ISSET(sc->sc_hwflags, COM_HW_FIFO)) {
879 			if (sc->sc_uarttype == COM_UART_TI16750) {
880 				bus_space_write_1(iot, ioh, com_lcr,
881 				    lcr | LCR_DLAB);
882 				bus_space_write_1(iot, ioh, com_fifo,
883 				    FIFO_ENABLE | FIFO_ENABLE_64BYTE |
884 				    (t->c_ispeed <= 1200 ? FIFO_TRIGGER_1 : FIFO_TRIGGER_8));
885 				bus_space_write_1(iot, ioh, com_lcr, lcr);
886 			} else
887 				bus_space_write_1(iot, ioh, com_fifo,
888 				    FIFO_ENABLE |
889 				    (t->c_ispeed <= 1200 ? FIFO_TRIGGER_1 : FIFO_TRIGGER_8));
890 		}
891 	} else
892 		bus_space_write_1(iot, ioh, com_lcr, lcr);
893 
894 	/* When not using CRTSCTS, RTS follows DTR. */
895 	if (!ISSET(t->c_cflag, CRTSCTS)) {
896 		if (ISSET(sc->sc_mcr, MCR_DTR)) {
897 			if (!ISSET(sc->sc_mcr, MCR_RTS)) {
898 				SET(sc->sc_mcr, MCR_RTS);
899 				bus_space_write_1(iot, ioh, com_mcr, sc->sc_mcr);
900 			}
901 		} else {
902 			if (ISSET(sc->sc_mcr, MCR_RTS)) {
903 				CLR(sc->sc_mcr, MCR_RTS);
904 				bus_space_write_1(iot, ioh, com_mcr, sc->sc_mcr);
905 			}
906 		}
907 		sc->sc_dtr = MCR_DTR | MCR_RTS;
908 	} else
909 		sc->sc_dtr = MCR_DTR;
910 
911 	/* and copy to tty */
912 	tp->t_ispeed = t->c_ispeed;
913 	tp->t_ospeed = t->c_ospeed;
914 	oldcflag = tp->t_cflag;
915 	tp->t_cflag = t->c_cflag;
916 
917 	/*
918 	 * If DCD is off and MDMBUF is changed, ask the tty layer if we should
919 	 * stop the device.
920 	 */
921 	if (!ISSET(sc->sc_msr, MSR_DCD) &&
922 	    !ISSET(sc->sc_swflags, COM_SW_SOFTCAR) &&
923 	    ISSET(oldcflag, MDMBUF) != ISSET(tp->t_cflag, MDMBUF) &&
924 	    (*linesw[tp->t_line].l_modem)(tp, 0) == 0) {
925 		CLR(sc->sc_mcr, sc->sc_dtr);
926 		bus_space_write_1(iot, ioh, com_mcr, sc->sc_mcr);
927 	}
928 
929 	/* Just to be sure... */
930 	comstart(tp);
931 	return 0;
932 }
933 
934 void
935 comstart(struct tty *tp)
936 {
937 	struct com_softc *sc = com_cd.cd_devs[DEVUNIT(tp->t_dev)];
938 	bus_space_tag_t iot = sc->sc_iot;
939 	bus_space_handle_t ioh = sc->sc_ioh;
940 	int s;
941 
942 	s = spltty();
943 	if (ISSET(tp->t_state, TS_BUSY))
944 		goto out;
945 	if (ISSET(tp->t_state, TS_TIMEOUT | TS_TTSTOP) || sc->sc_halt > 0)
946 		goto stopped;
947 	if (ISSET(tp->t_cflag, CRTSCTS) && !ISSET(sc->sc_msr, MSR_CTS))
948 		goto stopped;
949 	ttwakeupwr(tp);
950 	if (tp->t_outq.c_cc == 0)
951 		goto stopped;
952 	SET(tp->t_state, TS_BUSY);
953 
954 	/* Enable transmit completion interrupts. */
955 	if (!ISSET(sc->sc_ier, IER_ETXRDY)) {
956 		SET(sc->sc_ier, IER_ETXRDY);
957 		bus_space_write_1(iot, ioh, com_ier, sc->sc_ier);
958 	}
959 
960 	if (ISSET(sc->sc_hwflags, COM_HW_FIFO)) {
961 		u_char buffer[128];	/* largest fifo */
962 		int i, n;
963 
964 		n = q_to_b(&tp->t_outq, buffer,
965 		    min(sc->sc_fifolen, sizeof buffer));
966 		for (i = 0; i < n; i++) {
967 			bus_space_write_1(iot, ioh, com_data, buffer[i]);
968 		}
969 		bzero(buffer, n);
970 	} else if (tp->t_outq.c_cc != 0)
971 		bus_space_write_1(iot, ioh, com_data, getc(&tp->t_outq));
972 out:
973 	splx(s);
974 	return;
975 stopped:
976 	if (ISSET(sc->sc_ier, IER_ETXRDY)) {
977 		CLR(sc->sc_ier, IER_ETXRDY);
978 		bus_space_write_1(iot, ioh, com_ier, sc->sc_ier);
979 	}
980 	splx(s);
981 }
982 
983 /*
984  * Stop output on a line.
985  */
986 int
987 comstop(struct tty *tp, int flag)
988 {
989 	int s;
990 
991 	s = spltty();
992 	if (ISSET(tp->t_state, TS_BUSY))
993 		if (!ISSET(tp->t_state, TS_TTSTOP))
994 			SET(tp->t_state, TS_FLUSH);
995 	splx(s);
996 	return 0;
997 }
998 
999 void
1000 comdiag(void *arg)
1001 {
1002 	struct com_softc *sc = arg;
1003 	int overflows, floods;
1004 	int s;
1005 
1006 	s = spltty();
1007 	sc->sc_errors = 0;
1008 	overflows = sc->sc_overflows;
1009 	sc->sc_overflows = 0;
1010 	floods = sc->sc_floods;
1011 	sc->sc_floods = 0;
1012 	splx(s);
1013 	log(LOG_WARNING, "%s: %d silo overflow%s, %d ibuf overflow%s\n",
1014 	    sc->sc_dev.dv_xname,
1015 	    overflows, overflows == 1 ? "" : "s",
1016 	    floods, floods == 1 ? "" : "s");
1017 }
1018 
1019 void
1020 comsoft(void *arg)
1021 {
1022 	struct com_softc *sc = (struct com_softc *)arg;
1023 	struct tty *tp;
1024 	u_char *ibufp;
1025 	u_char *ibufend;
1026 	int c;
1027 	int s;
1028 	static int lsrmap[8] = {
1029 		0,      TTY_PE,
1030 		TTY_FE, TTY_PE|TTY_FE,
1031 		TTY_FE, TTY_PE|TTY_FE,
1032 		TTY_FE, TTY_PE|TTY_FE
1033 	};
1034 
1035 	if (sc == NULL || sc->sc_ibufp == sc->sc_ibuf)
1036 		return;
1037 
1038 	tp = sc->sc_tty;
1039 
1040 	s = spltty();
1041 
1042 	ibufp = sc->sc_ibuf;
1043 	ibufend = sc->sc_ibufp;
1044 
1045 	if (ibufp == ibufend) {
1046 		splx(s);
1047 		return;
1048 	}
1049 
1050 	sc->sc_ibufp = sc->sc_ibuf = (ibufp == sc->sc_ibufs[0]) ?
1051 				     sc->sc_ibufs[1] : sc->sc_ibufs[0];
1052 	sc->sc_ibufhigh = sc->sc_ibuf + COM_IHIGHWATER;
1053 	sc->sc_ibufend = sc->sc_ibuf + COM_IBUFSIZE;
1054 
1055 	if (tp == NULL || !ISSET(tp->t_state, TS_ISOPEN)) {
1056 		splx(s);
1057 		return;
1058 	}
1059 
1060 	if (ISSET(tp->t_cflag, CRTSCTS) &&
1061 	    !ISSET(sc->sc_mcr, MCR_RTS)) {
1062 		/* XXX */
1063 		SET(sc->sc_mcr, MCR_RTS);
1064 		bus_space_write_1(sc->sc_iot, sc->sc_ioh, com_mcr,
1065 		    sc->sc_mcr);
1066 	}
1067 
1068 	splx(s);
1069 
1070 	while (ibufp < ibufend) {
1071 		c = *ibufp++;
1072 		if (ISSET(*ibufp, LSR_OE)) {
1073 			sc->sc_overflows++;
1074 			if (sc->sc_errors++ == 0)
1075 				timeout_add_sec(&sc->sc_diag_tmo, 60);
1076 		}
1077 		/* This is ugly, but fast. */
1078 		c |= lsrmap[(*ibufp++ & (LSR_BI|LSR_FE|LSR_PE)) >> 2];
1079 		(*linesw[tp->t_line].l_rint)(c, tp);
1080 	}
1081 }
1082 
1083 #ifdef KGDB
1084 
1085 /*
1086  * If a line break is set, or data matches one of the characters
1087  * gdb uses to signal a connection, then start up kgdb. Just gobble
1088  * any other data. Done in a stand alone function because comintr
1089  * does tty stuff and we don't have one.
1090  */
1091 
1092 int
1093 kgdbintr(void *arg)
1094 {
1095 	struct com_softc *sc = arg;
1096 	bus_space_tag_t iot = sc->sc_iot;
1097 	bus_space_handle_t ioh = sc->sc_ioh;
1098 	u_char lsr, data, msr, delta;
1099 
1100 	if (!ISSET(sc->sc_hwflags, COM_HW_KGDB))
1101 		return(0);
1102 
1103 	for (;;) {
1104 		lsr = bus_space_read_1(iot, ioh, com_lsr);
1105 		if (ISSET(lsr, LSR_RXRDY)) {
1106 			do {
1107 				data = bus_space_read_1(iot, ioh, com_data);
1108 				if (data == 3 || data == '$' || data == '+' ||
1109 				    ISSET(lsr, LSR_BI)) {
1110 					kgdb_connect(1);
1111 					data = 0;
1112 				}
1113 				lsr = bus_space_read_1(iot, ioh, com_lsr);
1114 			} while (ISSET(lsr, LSR_RXRDY));
1115 
1116 		}
1117 		if (ISSET(lsr, LSR_BI|LSR_FE|LSR_PE|LSR_OE))
1118 			printf("weird lsr %02x\n", lsr);
1119 
1120 		msr = bus_space_read_1(iot, ioh, com_msr);
1121 
1122 		if (msr != sc->sc_msr) {
1123 			delta = msr ^ sc->sc_msr;
1124 			sc->sc_msr = msr;
1125 			if (ISSET(delta, MSR_DCD)) {
1126 				if (!ISSET(sc->sc_swflags, COM_SW_SOFTCAR)) {
1127 					CLR(sc->sc_mcr, sc->sc_dtr);
1128 					bus_space_write_1(iot, ioh, com_mcr, sc->sc_mcr);
1129 				}
1130 			}
1131 		}
1132 		if (ISSET(bus_space_read_1(iot, ioh, com_iir), IIR_NOPEND))
1133 			return (1);
1134 	}
1135 }
1136 #endif /* KGDB */
1137 
1138 int
1139 comintr(void *arg)
1140 {
1141 	struct com_softc *sc = arg;
1142 	bus_space_tag_t iot = sc->sc_iot;
1143 	bus_space_handle_t ioh = sc->sc_ioh;
1144 	struct tty *tp;
1145 	u_char lsr, data, msr, delta;
1146 
1147 	if (!sc->sc_tty)
1148 		return (0);		/* Can't do squat. */
1149 
1150 	if (ISSET(bus_space_read_1(iot, ioh, com_iir), IIR_NOPEND))
1151 		return (0);
1152 
1153 	tp = sc->sc_tty;
1154 
1155 	for (;;) {
1156 		lsr = bus_space_read_1(iot, ioh, com_lsr);
1157 
1158 		if (ISSET(lsr, LSR_RXRDY)) {
1159 			u_char *p = sc->sc_ibufp;
1160 
1161 			softintr_schedule(sc->sc_si);
1162 			do {
1163 				data = bus_space_read_1(iot, ioh, com_data);
1164 				if (ISSET(lsr, LSR_BI)) {
1165 #if defined(COM_CONSOLE) && defined(DDB)
1166 					if (ISSET(sc->sc_hwflags,
1167 					    COM_HW_CONSOLE)) {
1168 						if (db_console)
1169 							Debugger();
1170 						goto next;
1171 					}
1172 #endif
1173 					data = 0;
1174 				}
1175 				if (p >= sc->sc_ibufend) {
1176 					sc->sc_floods++;
1177 					if (sc->sc_errors++ == 0)
1178 						timeout_add_sec(&sc->sc_diag_tmo, 60);
1179 				} else {
1180 					*p++ = data;
1181 					*p++ = lsr;
1182 					if (p == sc->sc_ibufhigh &&
1183 					    ISSET(tp->t_cflag, CRTSCTS)) {
1184 						/* XXX */
1185 						CLR(sc->sc_mcr, MCR_RTS);
1186 						bus_space_write_1(iot, ioh, com_mcr,
1187 						    sc->sc_mcr);
1188 					}
1189 				}
1190 #if defined(COM_CONSOLE) && defined(DDB)
1191 			next:
1192 #endif
1193 				lsr = bus_space_read_1(iot, ioh, com_lsr);
1194 			} while (ISSET(lsr, LSR_RXRDY));
1195 
1196 			sc->sc_ibufp = p;
1197 		}
1198 		msr = bus_space_read_1(iot, ioh, com_msr);
1199 
1200 		if (msr != sc->sc_msr) {
1201 			delta = msr ^ sc->sc_msr;
1202 
1203 			ttytstamp(tp, sc->sc_msr & MSR_CTS, msr & MSR_CTS,
1204 			    sc->sc_msr & MSR_DCD, msr & MSR_DCD);
1205 
1206 			sc->sc_msr = msr;
1207 			if (ISSET(delta, MSR_DCD)) {
1208 				if (!ISSET(sc->sc_swflags, COM_SW_SOFTCAR) &&
1209 				    (*linesw[tp->t_line].l_modem)(tp, ISSET(msr, MSR_DCD)) == 0) {
1210 					CLR(sc->sc_mcr, sc->sc_dtr);
1211 					bus_space_write_1(iot, ioh, com_mcr, sc->sc_mcr);
1212 				}
1213 			}
1214 			if (ISSET(delta & msr, MSR_CTS) &&
1215 			    ISSET(tp->t_cflag, CRTSCTS)) {
1216 				/* the line is up and we want to do rts/cts flow control */
1217 				(*linesw[tp->t_line].l_start)(tp);
1218 			}
1219 		}
1220 
1221 		if (ISSET(lsr, LSR_TXRDY) && ISSET(tp->t_state, TS_BUSY)) {
1222 			CLR(tp->t_state, TS_BUSY | TS_FLUSH);
1223 			if (sc->sc_halt > 0)
1224 				wakeup(&tp->t_outq);
1225 			(*linesw[tp->t_line].l_start)(tp);
1226 		}
1227 
1228 		if (ISSET(bus_space_read_1(iot, ioh, com_iir), IIR_NOPEND))
1229 			return (1);
1230 	}
1231 }
1232 
1233 /*
1234  * The following functions are polled getc and putc routines, shared
1235  * by the console and kgdb glue.
1236  */
1237 
1238 int
1239 com_common_getc(bus_space_tag_t iot, bus_space_handle_t ioh)
1240 {
1241 	int s = splhigh();
1242 	u_char stat, c;
1243 
1244 	/* Block until a character becomes available. */
1245 	while (!ISSET(stat = bus_space_read_1(iot, ioh, com_lsr), LSR_RXRDY))
1246 		continue;
1247 
1248 	c = bus_space_read_1(iot, ioh, com_data);
1249 
1250 	/* Clear any interrupts generated by this transmission. */
1251 	stat = bus_space_read_1(iot, ioh, com_iir);
1252 	splx(s);
1253 	return (c);
1254 }
1255 
1256 void
1257 com_common_putc(bus_space_tag_t iot, bus_space_handle_t ioh, int c)
1258 {
1259 	int s = spltty();
1260 	int timo;
1261 
1262 	/* Wait for any pending transmission to finish. */
1263 	timo = 2000;
1264 	while (!ISSET(bus_space_read_1(iot, ioh, com_lsr), LSR_TXRDY) && --timo)
1265 		delay(1);
1266 
1267 	bus_space_write_1(iot, ioh, com_data, (u_int8_t)(c & 0xff));
1268 	bus_space_barrier(iot, ioh, 0, COM_NPORTS,
1269 	    (BUS_SPACE_BARRIER_READ|BUS_SPACE_BARRIER_WRITE));
1270 
1271 	/* Wait for this transmission to complete. */
1272 	timo = 2000;
1273 	while (!ISSET(bus_space_read_1(iot, ioh, com_lsr), LSR_TXRDY) && --timo)
1274 		delay(1);
1275 
1276 	splx(s);
1277 }
1278 
1279 void
1280 cominit(bus_space_tag_t iot, bus_space_handle_t ioh, int rate, int frequency)
1281 {
1282 	int s = splhigh();
1283 	u_char stat;
1284 
1285 	bus_space_write_1(iot, ioh, com_lcr, LCR_DLAB);
1286 	rate = comspeed(frequency, rate); /* XXX not comdefaultrate? */
1287 	bus_space_write_1(iot, ioh, com_dlbl, rate);
1288 	bus_space_write_1(iot, ioh, com_dlbh, rate >> 8);
1289 	bus_space_write_1(iot, ioh, com_lcr, LCR_8BITS);
1290 	bus_space_write_1(iot, ioh, com_mcr, MCR_DTR | MCR_RTS);
1291 	bus_space_write_1(iot, ioh, com_ier, 0);  /* Make sure they are off */
1292 	bus_space_write_1(iot, ioh, com_fifo,
1293 	    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_1);
1294 	stat = bus_space_read_1(iot, ioh, com_iir);
1295 	splx(s);
1296 }
1297 
1298 #ifdef COM_CONSOLE
1299 void
1300 comcnprobe(struct consdev *cp)
1301 {
1302 	bus_space_handle_t ioh;
1303 	int found;
1304 
1305 	if (comconsaddr == 0)
1306 		return;
1307 
1308 	if (bus_space_map(comconsiot, comconsaddr, COM_NPORTS, 0, &ioh))
1309 		return;
1310 	found = comprobe1(comconsiot, ioh);
1311 	bus_space_unmap(comconsiot, ioh, COM_NPORTS);
1312 	if (!found)
1313 		return;
1314 
1315 	/* Locate the major number. */
1316 	for (commajor = 0; commajor < nchrdev; commajor++)
1317 		if (cdevsw[commajor].d_open == comopen)
1318 			break;
1319 
1320 	/* Initialize required fields. */
1321 	cp->cn_dev = makedev(commajor, comconsunit);
1322 	cp->cn_pri = CN_HIGHPRI;
1323 }
1324 
1325 void
1326 comcninit(struct consdev *cp)
1327 {
1328 	if (bus_space_map(comconsiot, comconsaddr, COM_NPORTS, 0, &comconsioh))
1329 		panic("comcninit: mapping failed");
1330 
1331 	if (comconsfreq == 0)
1332 		comconsfreq = COM_FREQ;
1333 
1334 	cominit(comconsiot, comconsioh, comconsrate, comconsfreq);
1335 }
1336 
1337 int
1338 comcnattach(bus_space_tag_t iot, bus_addr_t iobase, int rate,
1339     int frequency, tcflag_t cflag)
1340 {
1341 	static struct consdev comcons = {
1342 		NULL, NULL, comcngetc, comcnputc, comcnpollc, NULL,
1343 		NODEV, CN_LOWPRI
1344 	};
1345 
1346 #ifndef __sparc64__
1347 	if (bus_space_map(iot, iobase, COM_NPORTS, 0, &comconsioh))
1348 		return ENOMEM;
1349 #endif
1350 
1351 	cominit(iot, comconsioh, rate, frequency);
1352 
1353 	cn_tab = &comcons;
1354 
1355 	comconsiot = iot;
1356 	comconsaddr = iobase;
1357 	comconscflag = cflag;
1358 	comconsfreq = frequency;
1359 	comconsrate = rate;
1360 
1361 	return (0);
1362 }
1363 
1364 int
1365 comcngetc(dev_t dev)
1366 {
1367 	return (com_common_getc(comconsiot, comconsioh));
1368 }
1369 
1370 /*
1371  * Console kernel output character routine.
1372  */
1373 void
1374 comcnputc(dev_t dev, int c)
1375 {
1376 	com_common_putc(comconsiot, comconsioh, c);
1377 }
1378 
1379 void
1380 comcnpollc(dev_t dev, int on)
1381 {
1382 
1383 }
1384 #endif	/* COM_CONSOLE */
1385 
1386 #ifdef KGDB
1387 int
1388 com_kgdb_attach(bus_space_tag_t iot, bus_addr_t iobase, int rate,
1389     int frequency, tcflag_t cflag)
1390 {
1391 #ifdef COM_CONSOLE
1392 	if (iot == comconsiot && iobase == comconsaddr) {
1393 		return (EBUSY); /* cannot share with console */
1394 	}
1395 #endif
1396 
1397 	com_kgdb_iot = iot;
1398 	com_kgdb_addr = iobase;
1399 
1400 	if (bus_space_map(com_kgdb_iot, com_kgdb_addr, COM_NPORTS, 0,
1401 	    &com_kgdb_ioh))
1402 		panic("com_kgdb_attach: mapping failed");
1403 
1404 	/* XXX We currently don't respect KGDBMODE? */
1405 	cominit(com_kgdb_iot, com_kgdb_ioh, rate, frequency);
1406 
1407 	kgdb_attach(com_kgdb_getc, com_kgdb_putc, NULL);
1408 	kgdb_dev = 123; /* unneeded, only to satisfy some tests */
1409 
1410 	return (0);
1411 }
1412 
1413 /* ARGSUSED */
1414 int
1415 com_kgdb_getc(void *arg)
1416 {
1417 
1418 	return (com_common_getc(com_kgdb_iot, com_kgdb_ioh));
1419 }
1420 
1421 /* ARGSUSED */
1422 void
1423 com_kgdb_putc(void *arg, int c)
1424 {
1425 
1426 	return (com_common_putc(com_kgdb_iot, com_kgdb_ioh, c));
1427 }
1428 #endif /* KGDB */
1429 
1430 void	com_enable_debugport(struct com_softc *);
1431 void	com_fifo_probe(struct com_softc *);
1432 
1433 #if defined(COM_CONSOLE) || defined(KGDB)
1434 void
1435 com_enable_debugport(struct com_softc *sc)
1436 {
1437 	int s;
1438 
1439 	/* Turn on line break interrupt, set carrier. */
1440 	s = splhigh();
1441 #ifdef KGDB
1442 	SET(sc->sc_ier, IER_ERXRDY);
1443 	bus_space_write_1(sc->sc_iot, sc->sc_ioh, com_ier, sc->sc_ier);
1444 #endif
1445 	SET(sc->sc_mcr, MCR_DTR | MCR_RTS | MCR_IENABLE);
1446 	bus_space_write_1(sc->sc_iot, sc->sc_ioh, com_mcr, sc->sc_mcr);
1447 
1448 	splx(s);
1449 }
1450 #endif	/* COM_CONSOLE || KGDB */
1451 
1452 void
1453 com_attach_subr(struct com_softc *sc)
1454 {
1455 	bus_space_tag_t iot = sc->sc_iot;
1456 	bus_space_handle_t ioh = sc->sc_ioh;
1457 	int probe = 0;
1458 	u_int8_t lcr;
1459 
1460 	sc->sc_ier = 0;
1461 	/* disable interrupts */
1462 	bus_space_write_1(iot, ioh, com_ier, sc->sc_ier);
1463 
1464 #ifdef COM_CONSOLE
1465 	if (sc->sc_iot == comconsiot && sc->sc_iobase == comconsaddr) {
1466 		comconsattached = 1;
1467 		delay(10000);			/* wait for output to finish */
1468 		SET(sc->sc_hwflags, COM_HW_CONSOLE);
1469 		SET(sc->sc_swflags, COM_SW_SOFTCAR);
1470 	}
1471 #endif
1472 
1473 	/*
1474 	 * Probe for all known forms of UART.
1475 	 */
1476 	lcr = bus_space_read_1(iot, ioh, com_lcr);
1477 	bus_space_write_1(iot, ioh, com_lcr, LCR_EFR);
1478 	bus_space_write_1(iot, ioh, com_efr, 0);
1479 	bus_space_write_1(iot, ioh, com_lcr, 0);
1480 
1481 	bus_space_write_1(iot, ioh, com_fifo, FIFO_ENABLE);
1482 	delay(100);
1483 
1484 	/*
1485 	 * Skip specific probes if attachment code knows it already.
1486 	 */
1487 	if (sc->sc_uarttype == COM_UART_UNKNOWN) {
1488 		switch (bus_space_read_1(iot, ioh, com_iir) >> 6) {
1489 		case 0:
1490 			sc->sc_uarttype = COM_UART_16450;
1491 			break;
1492 		case 2:
1493 			sc->sc_uarttype = COM_UART_16550;
1494 			break;
1495 		case 3:
1496 			sc->sc_uarttype = COM_UART_16550A;
1497 			break;
1498 		default:
1499 			sc->sc_uarttype = COM_UART_UNKNOWN;
1500 			break;
1501 		}
1502 		probe = 1;
1503 	}
1504 
1505 	/* Probe for ST16650s */
1506 	if (probe && sc->sc_uarttype == COM_UART_16550A) {
1507 		bus_space_write_1(iot, ioh, com_lcr, lcr | LCR_DLAB);
1508 		if (bus_space_read_1(iot, ioh, com_efr) == 0) {
1509 			bus_space_write_1(iot, ioh, com_efr, EFR_CTS);
1510 			if (bus_space_read_1(iot, ioh, com_efr) != 0)
1511 				sc->sc_uarttype = COM_UART_ST16650;
1512 			bus_space_write_1(iot, ioh, com_efr, 0);
1513 		} else {
1514 			bus_space_write_1(iot, ioh, com_lcr, LCR_EFR);
1515 			if (bus_space_read_1(iot, ioh, com_efr) == 0)
1516 				sc->sc_uarttype = COM_UART_ST16650V2;
1517 		}
1518 	}
1519 
1520 #if 0	/* until com works with large FIFOs */
1521 	/* Probe for XR16850s */
1522 	if (probe && sc->sc_uarttype == COM_UART_ST16650V2) {
1523 		u_int8_t dlbl, dlbh;
1524 
1525 		/* Enable latch access and get the current values. */
1526 		bus_space_write_1(iot, ioh, com_lcr, lcr | LCR_DLAB);
1527 		dlbl = bus_space_read_1(iot, ioh, com_dlbl);
1528 		dlbh = bus_space_read_1(iot, ioh, com_dlbh);
1529 
1530 		/* Zero out the latch divisors */
1531 		bus_space_write_1(iot, ioh, com_dlbl, 0);
1532 		bus_space_write_1(iot, ioh, com_dlbh, 0);
1533 
1534 		if (bus_space_read_1(iot, ioh, com_dlbh) == 0x10) {
1535 			sc->sc_uarttype = COM_UART_XR16850;
1536 			sc->sc_uartrev = bus_space_read_1(iot, ioh, com_dlbl);
1537 		}
1538 
1539 		/* Reset to original. */
1540 		bus_space_write_1(iot, ioh, com_dlbl, dlbl);
1541 		bus_space_write_1(iot, ioh, com_dlbh, dlbh);
1542 	}
1543 #endif
1544 
1545 	/* Probe for TI16750s */
1546 	if (probe && sc->sc_uarttype == COM_UART_16550A) {
1547 		bus_space_write_1(iot, ioh, com_lcr, lcr | LCR_DLAB);
1548 		bus_space_write_1(iot, ioh, com_fifo,
1549 		    FIFO_ENABLE | FIFO_ENABLE_64BYTE);
1550 		if ((bus_space_read_1(iot, ioh, com_iir) >> 5) == 7) {
1551 #if 0
1552 			bus_space_write_1(iot, ioh, com_lcr, 0);
1553 			if ((bus_space_read_1(iot, ioh, com_iir) >> 5) == 6)
1554 #endif
1555 				sc->sc_uarttype = COM_UART_TI16750;
1556 		}
1557 		bus_space_write_1(iot, ioh, com_fifo, FIFO_ENABLE);
1558 	}
1559 
1560 	/* Reset the LCR (latch access is probably enabled). */
1561 	bus_space_write_1(iot, ioh, com_lcr, lcr);
1562 
1563 	/* Probe for 8250 */
1564 	if (probe && sc->sc_uarttype == COM_UART_16450) {
1565 		u_int8_t scr0, scr1, scr2;
1566 
1567 		scr0 = bus_space_read_1(iot, ioh, com_scratch);
1568 		bus_space_write_1(iot, ioh, com_scratch, 0xa5);
1569 		scr1 = bus_space_read_1(iot, ioh, com_scratch);
1570 		bus_space_write_1(iot, ioh, com_scratch, 0x5a);
1571 		scr2 = bus_space_read_1(iot, ioh, com_scratch);
1572 		bus_space_write_1(iot, ioh, com_scratch, scr0);
1573 
1574 		if ((scr1 != 0xa5) || (scr2 != 0x5a))
1575 			sc->sc_uarttype = COM_UART_8250;
1576 	}
1577 
1578 	/*
1579 	 * Print UART type and initialize ourself.
1580 	 */
1581 	switch (sc->sc_uarttype) {
1582 	case COM_UART_UNKNOWN:
1583 		printf(": unknown uart\n");
1584 		break;
1585 	case COM_UART_8250:
1586 		printf(": ns8250, no fifo\n");
1587 		break;
1588 	case COM_UART_16450:
1589 		printf(": ns16450, no fifo\n");
1590 		break;
1591 	case COM_UART_16550:
1592 		printf(": ns16550, no working fifo\n");
1593 		break;
1594 	case COM_UART_16550A:
1595 		if (sc->sc_fifolen == 0)
1596 			sc->sc_fifolen = 16;
1597 		printf(": ns16550a, %d byte fifo\n", sc->sc_fifolen);
1598 		SET(sc->sc_hwflags, COM_HW_FIFO);
1599 		break;
1600 	case COM_UART_ST16650:
1601 		printf(": st16650, no working fifo\n");
1602 		break;
1603 	case COM_UART_ST16650V2:
1604 		if (sc->sc_fifolen == 0)
1605 			sc->sc_fifolen = 32;
1606 		printf(": st16650, %d byte fifo\n", sc->sc_fifolen);
1607 		SET(sc->sc_hwflags, COM_HW_FIFO);
1608 		break;
1609 	case COM_UART_ST16C654:
1610 		printf(": st16c654, 64 byte fifo\n");
1611 		SET(sc->sc_hwflags, COM_HW_FIFO);
1612 		sc->sc_fifolen = 64;
1613 		break;
1614 	case COM_UART_TI16750:
1615 		printf(": ti16750, 64 byte fifo\n");
1616 		SET(sc->sc_hwflags, COM_HW_FIFO);
1617 		sc->sc_fifolen = 64;
1618 		break;
1619 #if 0
1620 	case COM_UART_XR16850:
1621 		printf(": xr16850 (rev %d), 128 byte fifo\n", sc->sc_uartrev);
1622 		SET(sc->sc_hwflags, COM_HW_FIFO);
1623 		sc->sc_fifolen = 128;
1624 		break;
1625 #ifdef COM_UART_OX16C950
1626 	case COM_UART_OX16C950:
1627 		printf(": ox16c950 (rev %d), 128 byte fifo\n", sc->sc_uartrev);
1628 		SET(sc->sc_hwflags, COM_HW_FIFO);
1629 		sc->sc_fifolen = 128;
1630 		break;
1631 #endif
1632 #endif
1633 	default:
1634 		panic("comattach: bad fifo type");
1635 	}
1636 
1637 #ifdef KGDB
1638 	/*
1639 	 * Allow kgdb to "take over" this port.  If this is
1640 	 * the kgdb device, it has exclusive use.
1641 	 */
1642 
1643 	if (iot == com_kgdb_iot && sc->sc_iobase == com_kgdb_addr &&
1644 	    !ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
1645 		printf("%s: kgdb\n", sc->sc_dev.dv_xname);
1646 		SET(sc->sc_hwflags, COM_HW_KGDB);
1647 	}
1648 #endif /* KGDB */
1649 
1650 #if defined(COM_CONSOLE) || defined(KGDB)
1651 	if (!ISSET(sc->sc_hwflags, COM_HW_CONSOLE|COM_HW_KGDB))
1652 #endif
1653 		com_fifo_probe(sc);
1654 
1655 	if (sc->sc_fifolen == 0) {
1656 		CLR(sc->sc_hwflags, COM_HW_FIFO);
1657 		sc->sc_fifolen = 1;
1658 	}
1659 
1660 	/* clear and disable fifo */
1661 	bus_space_write_1(iot, ioh, com_fifo, FIFO_RCV_RST | FIFO_XMT_RST);
1662 	if (ISSET(bus_space_read_1(iot, ioh, com_lsr), LSR_RXRDY))
1663 		(void)bus_space_read_1(iot, ioh, com_data);
1664 	bus_space_write_1(iot, ioh, com_fifo, 0);
1665 
1666 	sc->sc_mcr = 0;
1667 	bus_space_write_1(iot, ioh, com_mcr, sc->sc_mcr);
1668 
1669 #ifdef COM_CONSOLE
1670 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
1671 		int maj;
1672 
1673 		/* locate the major number */
1674 		for (maj = 0; maj < nchrdev; maj++)
1675 			if (cdevsw[maj].d_open == comopen)
1676 				break;
1677 
1678 		if (maj < nchrdev && cn_tab->cn_dev == NODEV)
1679 			cn_tab->cn_dev = makedev(maj, sc->sc_dev.dv_unit);
1680 
1681 		printf("%s: console\n", sc->sc_dev.dv_xname);
1682 	}
1683 #endif
1684 
1685 	timeout_set(&sc->sc_diag_tmo, comdiag, sc);
1686 	timeout_set(&sc->sc_dtr_tmo, com_raisedtr, sc);
1687 	sc->sc_si = softintr_establish(IPL_TTY, comsoft, sc);
1688 	if (sc->sc_si == NULL)
1689 		panic("%s: can't establish soft interrupt",
1690 		    sc->sc_dev.dv_xname);
1691 
1692 	/*
1693 	 * If there are no enable/disable functions, assume the device
1694 	 * is always enabled.
1695 	 */
1696 	if (!sc->enable)
1697 		sc->enabled = 1;
1698 
1699 #if defined(COM_CONSOLE) || defined(KGDB)
1700 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE|COM_HW_KGDB))
1701 		com_enable_debugport(sc);
1702 #endif
1703 }
1704 
1705 void
1706 com_fifo_probe(struct com_softc *sc)
1707 {
1708 	bus_space_handle_t ioh = sc->sc_ioh;
1709 	bus_space_tag_t iot = sc->sc_iot;
1710 	u_int8_t fifo, ier;
1711 	int timo, len;
1712 
1713 	if (!ISSET(sc->sc_hwflags, COM_HW_FIFO))
1714 		return;
1715 
1716 	ier = 0;
1717 	bus_space_write_1(iot, ioh, com_ier, ier);
1718 	bus_space_write_1(iot, ioh, com_lcr, LCR_DLAB);
1719 	bus_space_write_1(iot, ioh, com_dlbl, 3);
1720 	bus_space_write_1(iot, ioh, com_dlbh, 0);
1721 	bus_space_write_1(iot, ioh, com_lcr, LCR_PNONE | LCR_8BITS);
1722 	bus_space_write_1(iot, ioh, com_mcr, MCR_LOOPBACK);
1723 
1724 	fifo = FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST;
1725 	if (sc->sc_uarttype == COM_UART_TI16750)
1726 		fifo |= FIFO_ENABLE_64BYTE;
1727 
1728 	bus_space_write_1(iot, ioh, com_fifo, fifo);
1729 
1730 	for (len = 0; len < 256; len++) {
1731 		bus_space_write_1(iot, ioh, com_data, (len + 1));
1732 		timo = 2000;
1733 		while (!ISSET(bus_space_read_1(iot, ioh, com_lsr),
1734 		    LSR_TXRDY) && --timo)
1735 			delay(1);
1736 		if (!timo)
1737 			break;
1738 	}
1739 
1740 	delay(100);
1741 
1742 	for (len = 0; len < 256; len++) {
1743 		timo = 2000;
1744 		while (!ISSET(bus_space_read_1(iot, ioh, com_lsr),
1745 		    LSR_RXRDY) && --timo)
1746 			delay(1);
1747 		if (!timo || bus_space_read_1(iot, ioh, com_data) != (len + 1))
1748 			break;
1749 	}
1750 
1751 	/* For safety, always use the smaller value. */
1752 	if (sc->sc_fifolen > len) {
1753 		printf("%s: probed fifo depth: %d bytes\n",
1754 		    sc->sc_dev.dv_xname, len);
1755 		sc->sc_fifolen = len;
1756 	}
1757 }
1758