xref: /openbsd/sys/dev/ic/com.c (revision 905646f0)
1 /*	$OpenBSD: com.c,v 1.173 2020/08/14 18:14:11 jcs 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/fcntl.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 #define	DEVUNIT(x)	(minor(x) & 0x7f)
119 #define	DEVCUA(x)	(minor(x) & 0x80)
120 
121 int
122 comspeed(long freq, long speed)
123 {
124 #define	divrnd(n, q)	(((n)*2/(q)+1)/2)	/* divide and round off */
125 
126 	int x, err;
127 
128 	if (speed == 0)
129 		return 0;
130 	if (speed < 0)
131 		return -1;
132 	x = divrnd((freq / 16), speed);
133 	if (x <= 0)
134 		return -1;
135 	err = divrnd((quad_t)freq * 1000 / 16, speed * x) - 1000;
136 	if (err < 0)
137 		err = -err;
138 	if (err > COM_TOLERANCE)
139 		return -1;
140 	return x;
141 
142 #undef	divrnd
143 }
144 
145 #ifdef COM_CONSOLE
146 int
147 comprobe1(bus_space_tag_t iot, bus_space_handle_t ioh)
148 {
149 	int i, k;
150 
151 	/* force access to id reg */
152 	bus_space_write_1(iot, ioh, com_lcr, 0);
153 	bus_space_write_1(iot, ioh, com_iir, 0);
154 	for (i = 0; i < 32; i++) {
155 		k = bus_space_read_1(iot, ioh, com_iir);
156 		if (k & 0x38) {
157 			bus_space_read_1(iot, ioh, com_data); /* cleanup */
158 		} else
159 			break;
160 	}
161 	if (i >= 32)
162 		return 0;
163 
164 	return 1;
165 }
166 #endif
167 
168 int
169 com_detach(struct device *self, int flags)
170 {
171 	struct com_softc *sc = (struct com_softc *)self;
172 	int maj, mn;
173 
174 	sc->sc_swflags |= COM_SW_DEAD;
175 
176 	/* Locate the major number. */
177 	for (maj = 0; maj < nchrdev; maj++)
178 		if (cdevsw[maj].d_open == comopen)
179 			break;
180 
181 	/* Nuke the vnodes for any open instances. */
182 	mn = self->dv_unit;
183 	vdevgone(maj, mn, mn, VCHR);
184 
185 	/* XXX a symbolic constant for the cua bit would be nicer. */
186 	mn |= 0x80;
187 	vdevgone(maj, mn, mn, VCHR);
188 
189 	timeout_del(&sc->sc_dtr_tmo);
190 	timeout_del(&sc->sc_diag_tmo);
191 	softintr_disestablish(sc->sc_si);
192 
193 	/* Detach and free the tty. */
194 	if (sc->sc_tty) {
195 		ttyfree(sc->sc_tty);
196 	}
197 
198 	return (0);
199 }
200 
201 int
202 com_activate(struct device *self, int act)
203 {
204 	struct com_softc *sc = (struct com_softc *)self;
205 	int s, rv = 0;
206 
207 	switch (act) {
208 	case DVACT_SUSPEND:
209 		if (timeout_del(&sc->sc_dtr_tmo)) {
210 			/* Make sure DTR gets raised upon resume. */
211 			SET(sc->sc_mcr, MCR_DTR | MCR_RTS);
212 		}
213 		timeout_del(&sc->sc_diag_tmo);
214 		break;
215 	case DVACT_RESUME:
216 		com_resume(sc);
217 		break;
218 	case DVACT_DEACTIVATE:
219 		if (sc->sc_hwflags & COM_HW_CONSOLE) {
220 			rv = EBUSY;
221 			break;
222 		}
223 
224 		s = spltty();
225 		if (sc->disable != NULL && sc->enabled != 0) {
226 			(*sc->disable)(sc);
227 			sc->enabled = 0;
228 		}
229 		splx(s);
230 		break;
231 	}
232 	return (rv);
233 }
234 
235 int
236 comopen(dev_t dev, int flag, int mode, struct proc *p)
237 {
238 	int unit = DEVUNIT(dev);
239 	struct com_softc *sc;
240 	struct tty *tp;
241 	int s;
242 	int error = 0;
243 
244 	if (unit >= com_cd.cd_ndevs)
245 		return ENXIO;
246 	sc = com_cd.cd_devs[unit];
247 	if (!sc)
248 		return ENXIO;
249 
250 	s = spltty();
251 	if (!sc->sc_tty) {
252 		tp = sc->sc_tty = ttymalloc(1000000);
253 	} else
254 		tp = sc->sc_tty;
255 	splx(s);
256 
257 	tp->t_oproc = comstart;
258 	tp->t_param = comparam;
259 	tp->t_dev = dev;
260 	if (!ISSET(tp->t_state, TS_ISOPEN)) {
261 		SET(tp->t_state, TS_WOPEN);
262 		ttychars(tp);
263 		tp->t_iflag = TTYDEF_IFLAG;
264 		tp->t_oflag = TTYDEF_OFLAG;
265 #ifdef COM_CONSOLE
266 		if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
267 			tp->t_cflag = comconscflag;
268 			tp->t_ispeed = tp->t_ospeed = comconsrate;
269 		} else
270 #endif
271 		{
272 			tp->t_cflag = TTYDEF_CFLAG;
273 			tp->t_ispeed = tp->t_ospeed = comdefaultrate;
274 		}
275 		if (ISSET(sc->sc_swflags, COM_SW_CLOCAL))
276 			SET(tp->t_cflag, CLOCAL);
277 		if (ISSET(sc->sc_swflags, COM_SW_CRTSCTS))
278 			SET(tp->t_cflag, CRTSCTS);
279 		if (ISSET(sc->sc_swflags, COM_SW_MDMBUF))
280 			SET(tp->t_cflag, MDMBUF);
281 		tp->t_lflag = TTYDEF_LFLAG;
282 
283 		s = spltty();
284 
285 		sc->sc_initialize = 1;
286 		comparam(tp, &tp->t_termios);
287 		ttsetwater(tp);
288 
289 		sc->sc_ibufp = sc->sc_ibuf = sc->sc_ibufs[0];
290 		sc->sc_ibufhigh = sc->sc_ibuf + COM_IHIGHWATER;
291 		sc->sc_ibufend = sc->sc_ibuf + COM_IBUFSIZE;
292 
293 		/*
294 		 * Wake up the sleepy heads.
295 		 */
296 		if (!ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
297 			switch (sc->sc_uarttype) {
298 			case COM_UART_ST16650:
299 			case COM_UART_ST16650V2:
300 				com_write_reg(sc, com_lcr, LCR_EFR);
301 				com_write_reg(sc, com_efr, EFR_ECB);
302 				com_write_reg(sc, com_ier, 0);
303 				com_write_reg(sc, com_efr, 0);
304 				com_write_reg(sc, com_lcr, 0);
305 				break;
306 			case COM_UART_TI16750:
307 				com_write_reg(sc, com_ier, 0);
308 				break;
309 			case COM_UART_XR17V35X:
310 				com_write_reg(sc, UART_EXAR_SLEEP, 0);
311 				break;
312 			}
313 		}
314 
315 		if (ISSET(sc->sc_hwflags, COM_HW_FIFO)) {
316 			u_int8_t fifo = FIFO_ENABLE|FIFO_RCV_RST|FIFO_XMT_RST;
317 			u_int8_t lcr;
318 
319 			if (tp->t_ispeed <= 1200)
320 				fifo |= FIFO_TRIGGER_1;
321 			else if (tp->t_ispeed <= 38400)
322 				fifo |= FIFO_TRIGGER_4;
323 			else
324 				fifo |= FIFO_TRIGGER_8;
325 			if (sc->sc_uarttype == COM_UART_TI16750) {
326 				fifo |= FIFO_ENABLE_64BYTE;
327 				lcr = com_read_reg(sc, com_lcr);
328 				com_write_reg(sc, com_lcr,
329 				    lcr | LCR_DLAB);
330 			}
331 
332 			/*
333 			 * (Re)enable and drain FIFOs.
334 			 *
335 			 * Certain SMC chips cause problems if the FIFOs are
336 			 * enabled while input is ready. Turn off the FIFO
337 			 * if necessary to clear the input. Test the input
338 			 * ready bit after enabling the FIFOs to handle races
339 			 * between enabling and fresh input.
340 			 *
341 			 * Set the FIFO threshold based on the receive speed.
342 			 */
343 			for (;;) {
344 				com_write_reg(sc, com_fifo, 0);
345 				delay(100);
346 				(void) com_read_reg(sc, com_data);
347 				com_write_reg(sc, com_fifo, fifo |
348 				    FIFO_RCV_RST | FIFO_XMT_RST);
349 				delay(100);
350 				if(!ISSET(com_read_reg(sc,
351 				    com_lsr), LSR_RXRDY))
352 					break;
353 			}
354 			if (sc->sc_uarttype == COM_UART_TI16750)
355 				com_write_reg(sc, com_lcr, lcr);
356 		}
357 
358 		/* Flush any pending I/O. */
359 		while (ISSET(com_read_reg(sc, com_lsr), LSR_RXRDY))
360 			(void) com_read_reg(sc, com_data);
361 
362 		/* You turn me on, baby! */
363 		sc->sc_mcr = MCR_DTR | MCR_RTS;
364 		if (!ISSET(sc->sc_hwflags, COM_HW_NOIEN))
365 			SET(sc->sc_mcr, MCR_IENABLE);
366 		com_write_reg(sc, com_mcr, sc->sc_mcr);
367 		sc->sc_ier = IER_ERXRDY | IER_ERLS | IER_EMSC;
368 		com_write_reg(sc, com_ier, sc->sc_ier);
369 
370 		sc->sc_msr = com_read_reg(sc, com_msr);
371 		if (ISSET(sc->sc_swflags, COM_SW_SOFTCAR) || DEVCUA(dev) ||
372 		    ISSET(sc->sc_msr, MSR_DCD) || ISSET(tp->t_cflag, MDMBUF))
373 			SET(tp->t_state, TS_CARR_ON);
374 		else
375 			CLR(tp->t_state, TS_CARR_ON);
376 	} else if (ISSET(tp->t_state, TS_XCLUDE) && suser(p) != 0)
377 		return EBUSY;
378 	else
379 		s = spltty();
380 
381 	if (DEVCUA(dev)) {
382 		if (ISSET(tp->t_state, TS_ISOPEN)) {
383 			/* Ah, but someone already is dialed in... */
384 			splx(s);
385 			return EBUSY;
386 		}
387 		sc->sc_cua = 1;		/* We go into CUA mode. */
388 	} else {
389 		/* tty (not cua) device; wait for carrier if necessary. */
390 		if (ISSET(flag, O_NONBLOCK)) {
391 			if (sc->sc_cua) {
392 				/* Opening TTY non-blocking... but the CUA is busy. */
393 				splx(s);
394 				return EBUSY;
395 			}
396 		} else {
397 			while (sc->sc_cua ||
398 			    (!ISSET(tp->t_cflag, CLOCAL) &&
399 				!ISSET(tp->t_state, TS_CARR_ON))) {
400 				SET(tp->t_state, TS_WOPEN);
401 				error = ttysleep(tp, &tp->t_rawq, TTIPRI | PCATCH, ttopen);
402 				/*
403 				 * If TS_WOPEN has been reset, that means the cua device
404 				 * has been closed.  We don't want to fail in that case,
405 				 * so just go around again.
406 				 */
407 				if (error && ISSET(tp->t_state, TS_WOPEN)) {
408 					CLR(tp->t_state, TS_WOPEN);
409 					if (!sc->sc_cua && !ISSET(tp->t_state, TS_ISOPEN))
410 						compwroff(sc);
411 					splx(s);
412 					return error;
413 				}
414 			}
415 		}
416 	}
417 	splx(s);
418 
419 	return (*linesw[tp->t_line].l_open)(dev, tp, p);
420 }
421 
422 int
423 comclose(dev_t dev, int flag, int mode, struct proc *p)
424 {
425 	int unit = DEVUNIT(dev);
426 	struct com_softc *sc = com_cd.cd_devs[unit];
427 	struct tty *tp = sc->sc_tty;
428 	int s;
429 
430 #ifdef COM_CONSOLE
431 	/* XXX This is for cons.c. */
432 	if (!ISSET(tp->t_state, TS_ISOPEN))
433 		return 0;
434 #endif
435 
436 	if(sc->sc_swflags & COM_SW_DEAD)
437 		return 0;
438 
439 	(*linesw[tp->t_line].l_close)(tp, flag, p);
440 	s = spltty();
441 	if (ISSET(tp->t_state, TS_WOPEN)) {
442 		/* tty device is waiting for carrier; drop dtr then re-raise */
443 		CLR(sc->sc_mcr, MCR_DTR | MCR_RTS);
444 		com_write_reg(sc, com_mcr, sc->sc_mcr);
445 		timeout_add_sec(&sc->sc_dtr_tmo, 2);
446 	} else {
447 		/* no one else waiting; turn off the uart */
448 		compwroff(sc);
449 	}
450 	CLR(tp->t_state, TS_BUSY | TS_FLUSH);
451 	sc->sc_cua = 0;
452 	splx(s);
453 	ttyclose(tp);
454 
455 #ifdef COM_CONSOLE
456 #ifdef notyet /* XXXX */
457 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
458 		ttyfree(tp);
459 		sc->sc_tty = 0;
460 	}
461 #endif
462 #endif
463 	return 0;
464 }
465 
466 void
467 compwroff(struct com_softc *sc)
468 {
469 	struct tty *tp = sc->sc_tty;
470 
471 	CLR(sc->sc_lcr, LCR_SBREAK);
472 	com_write_reg(sc, com_lcr, sc->sc_lcr);
473 	com_write_reg(sc, com_ier, 0);
474 	if (ISSET(tp->t_cflag, HUPCL) &&
475 	    !ISSET(sc->sc_swflags, COM_SW_SOFTCAR)) {
476 		/* XXX perhaps only clear DTR */
477 		sc->sc_mcr = 0;
478 		com_write_reg(sc, com_mcr, sc->sc_mcr);
479 	}
480 
481 	/*
482 	 * Turn FIFO off; enter sleep mode if possible.
483 	 */
484 	com_write_reg(sc, com_fifo, 0);
485 	delay(100);
486 	if (ISSET(com_read_reg(sc, com_lsr), LSR_RXRDY))
487 		(void) com_read_reg(sc, com_data);
488 	delay(100);
489 	com_write_reg(sc, com_fifo,
490 			  FIFO_RCV_RST | FIFO_XMT_RST);
491 
492 	if (!ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
493 		switch (sc->sc_uarttype) {
494 		case COM_UART_ST16650:
495 		case COM_UART_ST16650V2:
496 			com_write_reg(sc, com_lcr, LCR_EFR);
497 			com_write_reg(sc, com_efr, EFR_ECB);
498 			com_write_reg(sc, com_ier, IER_SLEEP);
499 			com_write_reg(sc, com_lcr, 0);
500 			break;
501 		case COM_UART_TI16750:
502 			com_write_reg(sc, com_ier, IER_SLEEP);
503 			break;
504 		case COM_UART_XR17V35X:
505 			com_write_reg(sc, UART_EXAR_SLEEP, 0xff);
506 			break;
507 		}
508 	}
509 }
510 
511 void
512 com_resume(struct com_softc *sc)
513 {
514 	struct tty *tp = sc->sc_tty;
515 	int ospeed;
516 
517 	if (!tp || !ISSET(tp->t_state, TS_ISOPEN)) {
518 #ifdef COM_CONSOLE
519 		if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE))
520 			cominit(comconsiot, comconsioh, comconsrate,
521 			    comconsfreq);
522 #endif
523 		return;
524 	}
525 
526 	/*
527 	 * Wake up the sleepy heads.
528 	 */
529 	if (!ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
530 		switch (sc->sc_uarttype) {
531 		case COM_UART_ST16650:
532 		case COM_UART_ST16650V2:
533 			com_write_reg(sc, com_lcr, LCR_EFR);
534 			com_write_reg(sc, com_efr, EFR_ECB);
535 			com_write_reg(sc, com_ier, 0);
536 			com_write_reg(sc, com_efr, 0);
537 			com_write_reg(sc, com_lcr, 0);
538 			break;
539 		case COM_UART_TI16750:
540 			com_write_reg(sc, com_ier, 0);
541 			break;
542 		case COM_UART_XR17V35X:
543 			com_write_reg(sc, UART_EXAR_SLEEP, 0);
544 			break;
545 		}
546 	}
547 
548 	ospeed = comspeed(sc->sc_frequency, tp->t_ospeed);
549 
550 	if (ospeed != 0) {
551 		com_write_reg(sc, com_lcr, sc->sc_lcr | LCR_DLAB);
552 		com_write_reg(sc, com_dlbl, ospeed);
553 		com_write_reg(sc, com_dlbh, ospeed >> 8);
554 		com_write_reg(sc, com_lcr, sc->sc_lcr);
555 	} else {
556 		com_write_reg(sc, com_lcr, sc->sc_lcr);
557 	}
558 
559 	if (ISSET(sc->sc_hwflags, COM_HW_FIFO)) {
560 		u_int8_t fifo = FIFO_ENABLE|FIFO_RCV_RST|FIFO_XMT_RST;
561 		u_int8_t lcr;
562 
563 		if (tp->t_ispeed <= 1200)
564 			fifo |= FIFO_TRIGGER_1;
565 		else if (tp->t_ispeed <= 38400)
566 			fifo |= FIFO_TRIGGER_4;
567 		else
568 			fifo |= FIFO_TRIGGER_8;
569 		if (sc->sc_uarttype == COM_UART_TI16750) {
570 			fifo |= FIFO_ENABLE_64BYTE;
571 			lcr = com_read_reg(sc, com_lcr);
572 			com_write_reg(sc, com_lcr,
573 			    lcr | LCR_DLAB);
574 		}
575 
576 		/*
577 		 * (Re)enable and drain FIFOs.
578 		 *
579 		 * Certain SMC chips cause problems if the FIFOs are
580 		 * enabled while input is ready. Turn off the FIFO
581 		 * if necessary to clear the input. Test the input
582 		 * ready bit after enabling the FIFOs to handle races
583 		 * between enabling and fresh input.
584 		 *
585 		 * Set the FIFO threshold based on the receive speed.
586 		 */
587 		for (;;) {
588 			com_write_reg(sc, com_fifo, 0);
589 			delay(100);
590 			(void) com_read_reg(sc, com_data);
591 			com_write_reg(sc, com_fifo, fifo |
592 			    FIFO_RCV_RST | FIFO_XMT_RST);
593 			delay(100);
594 			if(!ISSET(com_read_reg(sc,
595 			    com_lsr), LSR_RXRDY))
596 				break;
597 		}
598 		if (sc->sc_uarttype == COM_UART_TI16750)
599 			com_write_reg(sc, com_lcr, lcr);
600 	}
601 
602 	/* You turn me on, baby! */
603 	com_write_reg(sc, com_mcr, sc->sc_mcr);
604 	com_write_reg(sc, com_ier, sc->sc_ier);
605 }
606 
607 void
608 com_raisedtr(void *arg)
609 {
610 	struct com_softc *sc = arg;
611 
612 	SET(sc->sc_mcr, MCR_DTR | MCR_RTS);
613 	com_write_reg(sc, com_mcr, sc->sc_mcr);
614 }
615 
616 int
617 comread(dev_t dev, struct uio *uio, int flag)
618 {
619 	struct com_softc *sc = com_cd.cd_devs[DEVUNIT(dev)];
620 	struct tty *tp = sc->sc_tty;
621 
622 	return ((*linesw[tp->t_line].l_read)(tp, uio, flag));
623 }
624 
625 int
626 comwrite(dev_t dev, struct uio *uio, int flag)
627 {
628 	struct com_softc *sc = com_cd.cd_devs[DEVUNIT(dev)];
629 	struct tty *tp = sc->sc_tty;
630 
631 	return ((*linesw[tp->t_line].l_write)(tp, uio, flag));
632 }
633 
634 struct tty *
635 comtty(dev_t dev)
636 {
637 	struct com_softc *sc = com_cd.cd_devs[DEVUNIT(dev)];
638 	struct tty *tp = sc->sc_tty;
639 
640 	return (tp);
641 }
642 
643 static u_char
644 tiocm_xxx2mcr(int data)
645 {
646 	u_char m = 0;
647 
648 	if (ISSET(data, TIOCM_DTR))
649 		SET(m, MCR_DTR);
650 	if (ISSET(data, TIOCM_RTS))
651 		SET(m, MCR_RTS);
652 	return m;
653 }
654 
655 int
656 comioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct proc *p)
657 {
658 	int unit = DEVUNIT(dev);
659 	struct com_softc *sc = com_cd.cd_devs[unit];
660 	struct tty *tp = sc->sc_tty;
661 	int error;
662 
663 	error = (*linesw[tp->t_line].l_ioctl)(tp, cmd, data, flag, p);
664 	if (error >= 0)
665 		return error;
666 	error = ttioctl(tp, cmd, data, flag, p);
667 	if (error >= 0)
668 		return error;
669 
670 	switch (cmd) {
671 	case TIOCSBRK:
672 		SET(sc->sc_lcr, LCR_SBREAK);
673 		com_write_reg(sc, com_lcr, sc->sc_lcr);
674 		break;
675 	case TIOCCBRK:
676 		CLR(sc->sc_lcr, LCR_SBREAK);
677 		com_write_reg(sc, com_lcr, sc->sc_lcr);
678 		break;
679 	case TIOCSDTR:
680 		SET(sc->sc_mcr, sc->sc_dtr);
681 		com_write_reg(sc, com_mcr, sc->sc_mcr);
682 		break;
683 	case TIOCCDTR:
684 		CLR(sc->sc_mcr, sc->sc_dtr);
685 		com_write_reg(sc, com_mcr, sc->sc_mcr);
686 		break;
687 	case TIOCMSET:
688 		CLR(sc->sc_mcr, MCR_DTR | MCR_RTS);
689 	case TIOCMBIS:
690 		SET(sc->sc_mcr, tiocm_xxx2mcr(*(int *)data));
691 		com_write_reg(sc, com_mcr, sc->sc_mcr);
692 		break;
693 	case TIOCMBIC:
694 		CLR(sc->sc_mcr, tiocm_xxx2mcr(*(int *)data));
695 		com_write_reg(sc, com_mcr, sc->sc_mcr);
696 		break;
697 	case TIOCMGET: {
698 		u_char m;
699 		int bits = 0;
700 
701 		m = sc->sc_mcr;
702 		if (ISSET(m, MCR_DTR))
703 			SET(bits, TIOCM_DTR);
704 		if (ISSET(m, MCR_RTS))
705 			SET(bits, TIOCM_RTS);
706 		m = sc->sc_msr;
707 		if (ISSET(m, MSR_DCD))
708 			SET(bits, TIOCM_CD);
709 		if (ISSET(m, MSR_CTS))
710 			SET(bits, TIOCM_CTS);
711 		if (ISSET(m, MSR_DSR))
712 			SET(bits, TIOCM_DSR);
713 		if (ISSET(m, MSR_RI | MSR_TERI))
714 			SET(bits, TIOCM_RI);
715 		if (com_read_reg(sc, com_ier))
716 			SET(bits, TIOCM_LE);
717 		*(int *)data = bits;
718 		break;
719 	}
720 	case TIOCGFLAGS: {
721 		int driverbits, userbits = 0;
722 
723 		driverbits = sc->sc_swflags;
724 		if (ISSET(driverbits, COM_SW_SOFTCAR))
725 			SET(userbits, TIOCFLAG_SOFTCAR);
726 		if (ISSET(driverbits, COM_SW_CLOCAL))
727 			SET(userbits, TIOCFLAG_CLOCAL);
728 		if (ISSET(driverbits, COM_SW_CRTSCTS))
729 			SET(userbits, TIOCFLAG_CRTSCTS);
730 		if (ISSET(driverbits, COM_SW_MDMBUF))
731 			SET(userbits, TIOCFLAG_MDMBUF);
732 		if (ISSET(driverbits, COM_SW_PPS))
733 			SET(userbits, TIOCFLAG_PPS);
734 
735 		*(int *)data = userbits;
736 		break;
737 	}
738 	case TIOCSFLAGS: {
739 		int userbits, driverbits = 0;
740 
741 		error = suser(p);
742 		if (error != 0)
743 			return(EPERM);
744 
745 		userbits = *(int *)data;
746 		if (ISSET(userbits, TIOCFLAG_SOFTCAR) ||
747 		    ISSET(sc->sc_hwflags, COM_HW_CONSOLE))
748 			SET(driverbits, COM_SW_SOFTCAR);
749 		if (ISSET(userbits, TIOCFLAG_CLOCAL))
750 			SET(driverbits, COM_SW_CLOCAL);
751 		if (ISSET(userbits, TIOCFLAG_CRTSCTS))
752 			SET(driverbits, COM_SW_CRTSCTS);
753 		if (ISSET(userbits, TIOCFLAG_MDMBUF))
754 			SET(driverbits, COM_SW_MDMBUF);
755 		if (ISSET(userbits, TIOCFLAG_PPS))
756 			SET(driverbits, COM_SW_PPS);
757 
758 		sc->sc_swflags = driverbits;
759 		break;
760 	}
761 	default:
762 		return ENOTTY;
763 	}
764 
765 	return 0;
766 }
767 
768 /* already called at spltty */
769 int
770 comparam(struct tty *tp, struct termios *t)
771 {
772 	struct com_softc *sc = com_cd.cd_devs[DEVUNIT(tp->t_dev)];
773 	int ospeed = comspeed(sc->sc_frequency, t->c_ospeed);
774 	u_char lcr;
775 	tcflag_t oldcflag;
776 
777 	/* Check requested parameters. */
778 	if (ospeed < 0 || (t->c_ispeed && t->c_ispeed != t->c_ospeed))
779 		return EINVAL;
780 
781 	lcr = ISSET(sc->sc_lcr, LCR_SBREAK);
782 
783 	switch (ISSET(t->c_cflag, CSIZE)) {
784 	case CS5:
785 		SET(lcr, LCR_5BITS);
786 		break;
787 	case CS6:
788 		SET(lcr, LCR_6BITS);
789 		break;
790 	case CS7:
791 		SET(lcr, LCR_7BITS);
792 		break;
793 	case CS8:
794 		SET(lcr, LCR_8BITS);
795 		break;
796 	}
797 	if (ISSET(t->c_cflag, PARENB)) {
798 		SET(lcr, LCR_PENAB);
799 		if (!ISSET(t->c_cflag, PARODD))
800 			SET(lcr, LCR_PEVEN);
801 	}
802 	if (ISSET(t->c_cflag, CSTOPB))
803 		SET(lcr, LCR_STOPB);
804 
805 	sc->sc_lcr = lcr;
806 
807 	if (ospeed == 0) {
808 		CLR(sc->sc_mcr, MCR_DTR);
809 		com_write_reg(sc, com_mcr, sc->sc_mcr);
810 	}
811 
812 	/*
813 	 * Set the FIFO threshold based on the receive speed, if we are
814 	 * changing it.
815 	 */
816 	if (sc->sc_initialize || (tp->t_ispeed != t->c_ispeed)) {
817 		sc->sc_initialize = 0;
818 
819 		if (ospeed != 0) {
820 			/*
821 			 * Make sure the transmit FIFO is empty before
822 			 * proceeding.  If we don't do this, some revisions
823 			 * of the UART will hang.  Interestingly enough,
824 			 * even if we do this while the last character is
825 			 * still being pushed out, they don't hang.  This
826 			 * seems good enough.
827 			 */
828 			while (ISSET(tp->t_state, TS_BUSY)) {
829 				int error;
830 
831 				++sc->sc_halt;
832 				error = ttysleep(tp, &tp->t_outq,
833 				    TTOPRI | PCATCH, "comprm");
834 				--sc->sc_halt;
835 				if (error) {
836 					comstart(tp);
837 					return (error);
838 				}
839 			}
840 
841 			com_write_reg(sc, com_lcr, lcr | LCR_DLAB);
842 			com_write_reg(sc, com_dlbl, ospeed);
843 			com_write_reg(sc, com_dlbh, ospeed >> 8);
844 			com_write_reg(sc, com_lcr, lcr);
845 			SET(sc->sc_mcr, MCR_DTR);
846 			com_write_reg(sc, com_mcr, sc->sc_mcr);
847 		} else
848 			com_write_reg(sc, com_lcr, lcr);
849 
850 		if (ISSET(sc->sc_hwflags, COM_HW_FIFO)) {
851 			if (sc->sc_uarttype == COM_UART_TI16750) {
852 				com_write_reg(sc, com_lcr,
853 				    lcr | LCR_DLAB);
854 				com_write_reg(sc, com_fifo,
855 				    FIFO_ENABLE | FIFO_ENABLE_64BYTE |
856 				    (t->c_ispeed <= 1200 ? FIFO_TRIGGER_1 : FIFO_TRIGGER_8));
857 				com_write_reg(sc, com_lcr, lcr);
858 			} else
859 				com_write_reg(sc, com_fifo,
860 				    FIFO_ENABLE |
861 				    (t->c_ispeed <= 1200 ? FIFO_TRIGGER_1 : FIFO_TRIGGER_8));
862 		}
863 	} else
864 		com_write_reg(sc, com_lcr, lcr);
865 
866 	/* When not using CRTSCTS, RTS follows DTR. */
867 	if (!ISSET(t->c_cflag, CRTSCTS)) {
868 		if (ISSET(sc->sc_mcr, MCR_DTR)) {
869 			if (!ISSET(sc->sc_mcr, MCR_RTS)) {
870 				SET(sc->sc_mcr, MCR_RTS);
871 				com_write_reg(sc, com_mcr, sc->sc_mcr);
872 			}
873 		} else {
874 			if (ISSET(sc->sc_mcr, MCR_RTS)) {
875 				CLR(sc->sc_mcr, MCR_RTS);
876 				com_write_reg(sc, com_mcr, sc->sc_mcr);
877 			}
878 		}
879 		sc->sc_dtr = MCR_DTR | MCR_RTS;
880 	} else
881 		sc->sc_dtr = MCR_DTR;
882 
883 	/* and copy to tty */
884 	tp->t_ispeed = t->c_ispeed;
885 	tp->t_ospeed = t->c_ospeed;
886 	oldcflag = tp->t_cflag;
887 	tp->t_cflag = t->c_cflag;
888 
889 	/*
890 	 * If DCD is off and MDMBUF is changed, ask the tty layer if we should
891 	 * stop the device.
892 	 */
893 	if (!ISSET(sc->sc_msr, MSR_DCD) &&
894 	    !ISSET(sc->sc_swflags, COM_SW_SOFTCAR) &&
895 	    ISSET(oldcflag, MDMBUF) != ISSET(tp->t_cflag, MDMBUF) &&
896 	    (*linesw[tp->t_line].l_modem)(tp, 0) == 0) {
897 		CLR(sc->sc_mcr, sc->sc_dtr);
898 		com_write_reg(sc, com_mcr, sc->sc_mcr);
899 	}
900 
901 	/* Just to be sure... */
902 	comstart(tp);
903 	return 0;
904 }
905 
906 void
907 comstart(struct tty *tp)
908 {
909 	struct com_softc *sc = com_cd.cd_devs[DEVUNIT(tp->t_dev)];
910 	int s;
911 
912 	s = spltty();
913 	if (ISSET(tp->t_state, TS_BUSY))
914 		goto out;
915 	if (ISSET(tp->t_state, TS_TIMEOUT | TS_TTSTOP) || sc->sc_halt > 0)
916 		goto stopped;
917 	if (ISSET(tp->t_cflag, CRTSCTS) && !ISSET(sc->sc_msr, MSR_CTS))
918 		goto stopped;
919 	ttwakeupwr(tp);
920 	if (tp->t_outq.c_cc == 0)
921 		goto stopped;
922 	SET(tp->t_state, TS_BUSY);
923 
924 	/* Enable transmit completion interrupts. */
925 	if (!ISSET(sc->sc_ier, IER_ETXRDY)) {
926 		SET(sc->sc_ier, IER_ETXRDY);
927 		com_write_reg(sc, com_ier, sc->sc_ier);
928 	}
929 
930 	if (ISSET(sc->sc_hwflags, COM_HW_FIFO)) {
931 		u_char buffer[256];	/* largest fifo */
932 		int i, n;
933 
934 		n = q_to_b(&tp->t_outq, buffer,
935 		    min(sc->sc_fifolen, sizeof buffer));
936 		for (i = 0; i < n; i++) {
937 			com_write_reg(sc, com_data, buffer[i]);
938 		}
939 		bzero(buffer, n);
940 	} else if (tp->t_outq.c_cc != 0)
941 		com_write_reg(sc, com_data, getc(&tp->t_outq));
942 out:
943 	splx(s);
944 	return;
945 stopped:
946 	if (ISSET(sc->sc_ier, IER_ETXRDY)) {
947 		CLR(sc->sc_ier, IER_ETXRDY);
948 		com_write_reg(sc, com_ier, sc->sc_ier);
949 	}
950 	splx(s);
951 }
952 
953 /*
954  * Stop output on a line.
955  */
956 int
957 comstop(struct tty *tp, int flag)
958 {
959 	int s;
960 
961 	s = spltty();
962 	if (ISSET(tp->t_state, TS_BUSY))
963 		if (!ISSET(tp->t_state, TS_TTSTOP))
964 			SET(tp->t_state, TS_FLUSH);
965 	splx(s);
966 	return 0;
967 }
968 
969 void
970 comdiag(void *arg)
971 {
972 	struct com_softc *sc = arg;
973 	int overflows, floods;
974 	int s;
975 
976 	s = spltty();
977 	sc->sc_errors = 0;
978 	overflows = sc->sc_overflows;
979 	sc->sc_overflows = 0;
980 	floods = sc->sc_floods;
981 	sc->sc_floods = 0;
982 	splx(s);
983 	log(LOG_WARNING, "%s: %d silo overflow%s, %d ibuf overflow%s\n",
984 	    sc->sc_dev.dv_xname,
985 	    overflows, overflows == 1 ? "" : "s",
986 	    floods, floods == 1 ? "" : "s");
987 }
988 
989 void
990 comsoft(void *arg)
991 {
992 	struct com_softc *sc = (struct com_softc *)arg;
993 	struct tty *tp;
994 	u_char *ibufp;
995 	u_char *ibufend;
996 	int c;
997 	int s;
998 	static int lsrmap[8] = {
999 		0,      TTY_PE,
1000 		TTY_FE, TTY_PE|TTY_FE,
1001 		TTY_FE, TTY_PE|TTY_FE,
1002 		TTY_FE, TTY_PE|TTY_FE
1003 	};
1004 
1005 	if (sc == NULL || sc->sc_ibufp == sc->sc_ibuf)
1006 		return;
1007 
1008 	tp = sc->sc_tty;
1009 
1010 	s = spltty();
1011 
1012 	ibufp = sc->sc_ibuf;
1013 	ibufend = sc->sc_ibufp;
1014 
1015 	if (ibufp == ibufend) {
1016 		splx(s);
1017 		return;
1018 	}
1019 
1020 	sc->sc_ibufp = sc->sc_ibuf = (ibufp == sc->sc_ibufs[0]) ?
1021 				     sc->sc_ibufs[1] : sc->sc_ibufs[0];
1022 	sc->sc_ibufhigh = sc->sc_ibuf + COM_IHIGHWATER;
1023 	sc->sc_ibufend = sc->sc_ibuf + COM_IBUFSIZE;
1024 
1025 	if (tp == NULL || !ISSET(tp->t_state, TS_ISOPEN)) {
1026 		splx(s);
1027 		return;
1028 	}
1029 
1030 	if (ISSET(tp->t_cflag, CRTSCTS) &&
1031 	    !ISSET(sc->sc_mcr, MCR_RTS)) {
1032 		/* XXX */
1033 		SET(sc->sc_mcr, MCR_RTS);
1034 		com_write_reg(sc, com_mcr, sc->sc_mcr);
1035 	}
1036 
1037 	splx(s);
1038 
1039 	while (ibufp < ibufend) {
1040 		c = *ibufp++;
1041 		if (ISSET(*ibufp, LSR_OE)) {
1042 			sc->sc_overflows++;
1043 			if (sc->sc_errors++ == 0)
1044 				timeout_add_sec(&sc->sc_diag_tmo, 60);
1045 		}
1046 		/* This is ugly, but fast. */
1047 		c |= lsrmap[(*ibufp++ & (LSR_BI|LSR_FE|LSR_PE)) >> 2];
1048 		(*linesw[tp->t_line].l_rint)(c, tp);
1049 	}
1050 }
1051 
1052 int
1053 comintr(void *arg)
1054 {
1055 	struct com_softc *sc = arg;
1056 	struct tty *tp;
1057 	u_char lsr, data, msr, delta;
1058 
1059 	if (!sc->sc_tty)
1060 		return (0);		/* Can't do squat. */
1061 
1062 	if (ISSET(com_read_reg(sc, com_iir), IIR_NOPEND))
1063 		return (0);
1064 
1065 	tp = sc->sc_tty;
1066 
1067 	for (;;) {
1068 		lsr = com_read_reg(sc, com_lsr);
1069 
1070 		if (ISSET(lsr, LSR_RXRDY)) {
1071 			u_char *p = sc->sc_ibufp;
1072 
1073 			softintr_schedule(sc->sc_si);
1074 			do {
1075 				data = com_read_reg(sc, com_data);
1076 				if (ISSET(lsr, LSR_BI)) {
1077 #if defined(COM_CONSOLE) && defined(DDB)
1078 					if (ISSET(sc->sc_hwflags,
1079 					    COM_HW_CONSOLE)) {
1080 						if (db_console)
1081 							db_enter();
1082 						goto next;
1083 					}
1084 #endif
1085 					data = 0;
1086 				}
1087 				if (p >= sc->sc_ibufend) {
1088 					sc->sc_floods++;
1089 					if (sc->sc_errors++ == 0)
1090 						timeout_add_sec(&sc->sc_diag_tmo, 60);
1091 				} else {
1092 					*p++ = data;
1093 					*p++ = lsr;
1094 					if (p == sc->sc_ibufhigh &&
1095 					    ISSET(tp->t_cflag, CRTSCTS)) {
1096 						/* XXX */
1097 						CLR(sc->sc_mcr, MCR_RTS);
1098 						com_write_reg(sc, com_mcr,
1099 						    sc->sc_mcr);
1100 					}
1101 				}
1102 #if defined(COM_CONSOLE) && defined(DDB)
1103 			next:
1104 #endif
1105 				lsr = com_read_reg(sc, com_lsr);
1106 			} while (ISSET(lsr, LSR_RXRDY));
1107 
1108 			sc->sc_ibufp = p;
1109 		}
1110 		msr = com_read_reg(sc, com_msr);
1111 
1112 		if (msr != sc->sc_msr) {
1113 			delta = msr ^ sc->sc_msr;
1114 
1115 			ttytstamp(tp, sc->sc_msr & MSR_CTS, msr & MSR_CTS,
1116 			    sc->sc_msr & MSR_DCD, msr & MSR_DCD);
1117 
1118 			sc->sc_msr = msr;
1119 			if (ISSET(delta, MSR_DCD)) {
1120 				if (!ISSET(sc->sc_swflags, COM_SW_SOFTCAR) &&
1121 				    (*linesw[tp->t_line].l_modem)(tp, ISSET(msr, MSR_DCD)) == 0) {
1122 					CLR(sc->sc_mcr, sc->sc_dtr);
1123 					com_write_reg(sc, com_mcr, sc->sc_mcr);
1124 				}
1125 			}
1126 			if (ISSET(delta & msr, MSR_CTS) &&
1127 			    ISSET(tp->t_cflag, CRTSCTS)) {
1128 				/* the line is up and we want to do rts/cts flow control */
1129 				(*linesw[tp->t_line].l_start)(tp);
1130 			}
1131 		}
1132 
1133 		if (ISSET(lsr, LSR_TXRDY) && ISSET(tp->t_state, TS_BUSY)) {
1134 			CLR(tp->t_state, TS_BUSY | TS_FLUSH);
1135 			if (sc->sc_halt > 0)
1136 				wakeup(&tp->t_outq);
1137 			(*linesw[tp->t_line].l_start)(tp);
1138 		}
1139 
1140 		if (ISSET(com_read_reg(sc, com_iir), IIR_NOPEND))
1141 			return (1);
1142 	}
1143 }
1144 
1145 void
1146 cominit(bus_space_tag_t iot, bus_space_handle_t ioh, int rate, int frequency)
1147 {
1148 	int s = splhigh();
1149 	u_char stat;
1150 
1151 	bus_space_write_1(iot, ioh, com_lcr, LCR_DLAB);
1152 	rate = comspeed(frequency, rate); /* XXX not comdefaultrate? */
1153 	bus_space_write_1(iot, ioh, com_dlbl, rate);
1154 	bus_space_write_1(iot, ioh, com_dlbh, rate >> 8);
1155 	bus_space_write_1(iot, ioh, com_lcr, LCR_8BITS);
1156 	bus_space_write_1(iot, ioh, com_mcr, MCR_DTR | MCR_RTS);
1157 	bus_space_write_1(iot, ioh, com_ier, 0);  /* Make sure they are off */
1158 	bus_space_write_1(iot, ioh, com_fifo,
1159 	    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_1);
1160 	stat = bus_space_read_1(iot, ioh, com_iir);
1161 	splx(s);
1162 }
1163 
1164 #ifdef COM_CONSOLE
1165 void
1166 comcnprobe(struct consdev *cp)
1167 {
1168 	bus_space_handle_t ioh;
1169 	int found;
1170 
1171 	if (comconsaddr == 0)
1172 		return;
1173 
1174 	if (bus_space_map(comconsiot, comconsaddr, COM_NPORTS, 0, &ioh))
1175 		return;
1176 	found = comprobe1(comconsiot, ioh);
1177 	bus_space_unmap(comconsiot, ioh, COM_NPORTS);
1178 	if (!found)
1179 		return;
1180 
1181 	/* Locate the major number. */
1182 	for (commajor = 0; commajor < nchrdev; commajor++)
1183 		if (cdevsw[commajor].d_open == comopen)
1184 			break;
1185 
1186 	/* Initialize required fields. */
1187 	cp->cn_dev = makedev(commajor, comconsunit);
1188 	cp->cn_pri = CN_HIGHPRI;
1189 }
1190 
1191 void
1192 comcninit(struct consdev *cp)
1193 {
1194 	if (bus_space_map(comconsiot, comconsaddr, COM_NPORTS, 0, &comconsioh))
1195 		panic("comcninit: mapping failed");
1196 
1197 	if (comconsfreq == 0)
1198 		comconsfreq = COM_FREQ;
1199 
1200 	cominit(comconsiot, comconsioh, comconsrate, comconsfreq);
1201 }
1202 
1203 int
1204 comcnattach(bus_space_tag_t iot, bus_addr_t iobase, int rate,
1205     int frequency, tcflag_t cflag)
1206 {
1207 	static struct consdev comcons = {
1208 		NULL, NULL, comcngetc, comcnputc, comcnpollc, NULL,
1209 		NODEV, CN_LOWPRI
1210 	};
1211 
1212 #ifndef __sparc64__
1213 	if (bus_space_map(iot, iobase, COM_NPORTS, 0, &comconsioh))
1214 		return ENOMEM;
1215 #endif
1216 
1217 	cominit(iot, comconsioh, rate, frequency);
1218 
1219 	cn_tab = &comcons;
1220 
1221 	comconsiot = iot;
1222 	comconsaddr = iobase;
1223 	comconscflag = cflag;
1224 	comconsfreq = frequency;
1225 	comconsrate = rate;
1226 
1227 	return (0);
1228 }
1229 
1230 int
1231 comcngetc(dev_t dev)
1232 {
1233 	int s = splhigh();
1234 	u_char stat, c;
1235 
1236 	/* Block until a character becomes available. */
1237 	while (!ISSET(stat = comcn_read_reg(com_lsr), LSR_RXRDY))
1238 		continue;
1239 
1240 	c = comcn_read_reg(com_data);
1241 
1242 	/* Clear any interrupts generated by this transmission. */
1243 	stat = comcn_read_reg(com_iir);
1244 	splx(s);
1245 	return (c);
1246 }
1247 
1248 /*
1249  * Console kernel output character routine.
1250  */
1251 void
1252 comcnputc(dev_t dev, int c)
1253 {
1254 	int s = spltty();
1255 	int timo;
1256 
1257 	/* Wait for any pending transmission to finish. */
1258 	timo = 2000;
1259 	while (!ISSET(comcn_read_reg(com_lsr), LSR_TXRDY) && --timo)
1260 		delay(1);
1261 
1262 	comcn_write_reg(com_data, (u_int8_t)(c & 0xff));
1263 	bus_space_barrier(comconsiot, comconsioh, 0,
1264 	    COM_NPORTS << comcons_reg_shift,
1265 	    (BUS_SPACE_BARRIER_READ|BUS_SPACE_BARRIER_WRITE));
1266 
1267 	/* Wait for this transmission to complete. */
1268 	timo = 2000;
1269 	while (!ISSET(comcn_read_reg(com_lsr), LSR_TXRDY) && --timo)
1270 		delay(1);
1271 
1272 	splx(s);
1273 }
1274 
1275 void
1276 comcnpollc(dev_t dev, int on)
1277 {
1278 }
1279 #endif	/* COM_CONSOLE */
1280 
1281 void	com_enable_debugport(struct com_softc *);
1282 void	com_fifo_probe(struct com_softc *);
1283 
1284 #ifdef COM_CONSOLE
1285 void
1286 com_enable_debugport(struct com_softc *sc)
1287 {
1288 	int s;
1289 
1290 	/* Turn on line break interrupt, set carrier. */
1291 	s = splhigh();
1292 	SET(sc->sc_mcr, MCR_DTR | MCR_RTS | MCR_IENABLE);
1293 	com_write_reg(sc, com_mcr, sc->sc_mcr);
1294 
1295 	splx(s);
1296 }
1297 #endif	/* COM_CONSOLE */
1298 
1299 void
1300 com_attach_subr(struct com_softc *sc)
1301 {
1302 	int probe = 0;
1303 	u_int8_t lcr;
1304 
1305 	sc->sc_ier = 0;
1306 	/* disable interrupts */
1307 	com_write_reg(sc, com_ier, sc->sc_ier);
1308 
1309 #ifdef COM_CONSOLE
1310 	if (sc->sc_iot == comconsiot && sc->sc_iobase == comconsaddr) {
1311 		comconsattached = 1;
1312 		delay(10000);			/* wait for output to finish */
1313 		SET(sc->sc_hwflags, COM_HW_CONSOLE);
1314 		SET(sc->sc_swflags, COM_SW_SOFTCAR);
1315 	}
1316 #endif
1317 
1318 	/*
1319 	 * Probe for all known forms of UART.
1320 	 */
1321 	lcr = com_read_reg(sc, com_lcr);
1322 	com_write_reg(sc, com_lcr, LCR_EFR);
1323 	com_write_reg(sc, com_efr, 0);
1324 	com_write_reg(sc, com_lcr, 0);
1325 
1326 	com_write_reg(sc, com_fifo, FIFO_ENABLE);
1327 	delay(100);
1328 
1329 	/*
1330 	 * Skip specific probes if attachment code knows it already.
1331 	 */
1332 	if (sc->sc_uarttype == COM_UART_UNKNOWN) {
1333 		switch (com_read_reg(sc, com_iir) >> 6) {
1334 		case 0:
1335 			sc->sc_uarttype = COM_UART_16450;
1336 			break;
1337 		case 2:
1338 			sc->sc_uarttype = COM_UART_16550;
1339 			break;
1340 		case 3:
1341 			sc->sc_uarttype = COM_UART_16550A;
1342 			break;
1343 		default:
1344 			sc->sc_uarttype = COM_UART_UNKNOWN;
1345 			break;
1346 		}
1347 		probe = 1;
1348 	}
1349 
1350 	/* Probe for ST16650s */
1351 	if (probe && sc->sc_uarttype == COM_UART_16550A) {
1352 		com_write_reg(sc, com_lcr, lcr | LCR_DLAB);
1353 		if (com_read_reg(sc, com_efr) == 0) {
1354 			com_write_reg(sc, com_efr, EFR_CTS);
1355 			if (com_read_reg(sc, com_efr) != 0)
1356 				sc->sc_uarttype = COM_UART_ST16650;
1357 			com_write_reg(sc, com_efr, 0);
1358 		} else {
1359 			com_write_reg(sc, com_lcr, LCR_EFR);
1360 			if (com_read_reg(sc, com_efr) == 0)
1361 				sc->sc_uarttype = COM_UART_ST16650V2;
1362 		}
1363 	}
1364 
1365 #if 0	/* until com works with large FIFOs */
1366 	/* Probe for XR16850s */
1367 	if (probe && sc->sc_uarttype == COM_UART_ST16650V2) {
1368 		u_int8_t dlbl, dlbh;
1369 
1370 		/* Enable latch access and get the current values. */
1371 		com_write_reg(sc, com_lcr, lcr | LCR_DLAB);
1372 		dlbl = com_read_reg(sc, com_dlbl);
1373 		dlbh = com_read_reg(sc, com_dlbh);
1374 
1375 		/* Zero out the latch divisors */
1376 		com_write_reg(sc, com_dlbl, 0);
1377 		com_write_reg(sc, com_dlbh, 0);
1378 
1379 		if (com_read_reg(sc, com_dlbh) == 0x10) {
1380 			sc->sc_uarttype = COM_UART_XR16850;
1381 			sc->sc_uartrev = com_read_reg(sc, com_dlbl);
1382 		}
1383 
1384 		/* Reset to original. */
1385 		com_write_reg(sc, com_dlbl, dlbl);
1386 		com_write_reg(sc, com_dlbh, dlbh);
1387 	}
1388 #endif
1389 
1390 	/* Probe for TI16750s */
1391 	if (probe && sc->sc_uarttype == COM_UART_16550A) {
1392 		com_write_reg(sc, com_lcr, lcr | LCR_DLAB);
1393 		com_write_reg(sc, com_fifo,
1394 		    FIFO_ENABLE | FIFO_ENABLE_64BYTE);
1395 		if ((com_read_reg(sc, com_iir) >> 5) == 7) {
1396 #if 0
1397 			com_write_reg(sc, com_lcr, 0);
1398 			if ((com_read_reg(sc, com_iir) >> 5) == 6)
1399 #endif
1400 				sc->sc_uarttype = COM_UART_TI16750;
1401 		}
1402 		com_write_reg(sc, com_fifo, FIFO_ENABLE);
1403 	}
1404 
1405 	/* Reset the LCR (latch access is probably enabled). */
1406 	com_write_reg(sc, com_lcr, lcr);
1407 
1408 	/* Probe for 8250 */
1409 	if (probe && sc->sc_uarttype == COM_UART_16450) {
1410 		u_int8_t scr0, scr1, scr2;
1411 
1412 		scr0 = com_read_reg(sc, com_scratch);
1413 		com_write_reg(sc, com_scratch, 0xa5);
1414 		scr1 = com_read_reg(sc, com_scratch);
1415 		com_write_reg(sc, com_scratch, 0x5a);
1416 		scr2 = com_read_reg(sc, com_scratch);
1417 		com_write_reg(sc, com_scratch, scr0);
1418 
1419 		if ((scr1 != 0xa5) || (scr2 != 0x5a))
1420 			sc->sc_uarttype = COM_UART_8250;
1421 	}
1422 
1423 	/*
1424 	 * Print UART type and initialize ourself.
1425 	 */
1426 	switch (sc->sc_uarttype) {
1427 	case COM_UART_UNKNOWN:
1428 		printf(": unknown uart\n");
1429 		break;
1430 	case COM_UART_8250:
1431 		printf(": ns8250, no fifo\n");
1432 		break;
1433 	case COM_UART_16450:
1434 		printf(": ns16450, no fifo\n");
1435 		break;
1436 	case COM_UART_16550:
1437 		printf(": ns16550, no working fifo\n");
1438 		break;
1439 	case COM_UART_16550A:
1440 		if (sc->sc_fifolen == 0)
1441 			sc->sc_fifolen = 16;
1442 		printf(": ns16550a, %d byte fifo\n", sc->sc_fifolen);
1443 		SET(sc->sc_hwflags, COM_HW_FIFO);
1444 		break;
1445 	case COM_UART_ST16650:
1446 		printf(": st16650, no working fifo\n");
1447 		break;
1448 	case COM_UART_ST16650V2:
1449 		if (sc->sc_fifolen == 0)
1450 			sc->sc_fifolen = 32;
1451 		printf(": st16650, %d byte fifo\n", sc->sc_fifolen);
1452 		SET(sc->sc_hwflags, COM_HW_FIFO);
1453 		break;
1454 	case COM_UART_ST16C654:
1455 		printf(": st16c654, 64 byte fifo\n");
1456 		SET(sc->sc_hwflags, COM_HW_FIFO);
1457 		sc->sc_fifolen = 64;
1458 		break;
1459 	case COM_UART_TI16750:
1460 		printf(": ti16750, 64 byte fifo\n");
1461 		SET(sc->sc_hwflags, COM_HW_FIFO);
1462 		sc->sc_fifolen = 64;
1463 		break;
1464 #if 0
1465 	case COM_UART_XR16850:
1466 		printf(": xr16850 (rev %d), 128 byte fifo\n", sc->sc_uartrev);
1467 		SET(sc->sc_hwflags, COM_HW_FIFO);
1468 		sc->sc_fifolen = 128;
1469 		break;
1470 #ifdef COM_UART_OX16C950
1471 	case COM_UART_OX16C950:
1472 		printf(": ox16c950 (rev %d), 128 byte fifo\n", sc->sc_uartrev);
1473 		SET(sc->sc_hwflags, COM_HW_FIFO);
1474 		sc->sc_fifolen = 128;
1475 		break;
1476 #endif
1477 #endif
1478 	case COM_UART_XR17V35X:
1479 		printf(": xr17v35x, 256 byte fifo\n");
1480 		SET(sc->sc_hwflags, COM_HW_FIFO);
1481 		sc->sc_fifolen = 256;
1482 		break;
1483 	default:
1484 		panic("comattach: bad fifo type");
1485 	}
1486 
1487 #ifdef COM_CONSOLE
1488 	if (!ISSET(sc->sc_hwflags, COM_HW_CONSOLE))
1489 #endif
1490 		if (sc->sc_fifolen < 256)
1491 			com_fifo_probe(sc);
1492 
1493 	if (sc->sc_fifolen == 0) {
1494 		CLR(sc->sc_hwflags, COM_HW_FIFO);
1495 		sc->sc_fifolen = 1;
1496 	}
1497 
1498 	/* clear and disable fifo */
1499 	com_write_reg(sc, com_fifo, FIFO_RCV_RST | FIFO_XMT_RST);
1500 	if (ISSET(com_read_reg(sc, com_lsr), LSR_RXRDY))
1501 		(void)com_read_reg(sc, com_data);
1502 	com_write_reg(sc, com_fifo, 0);
1503 
1504 	sc->sc_mcr = 0;
1505 	com_write_reg(sc, com_mcr, sc->sc_mcr);
1506 
1507 #ifdef COM_CONSOLE
1508 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
1509 		int maj;
1510 
1511 		/* locate the major number */
1512 		for (maj = 0; maj < nchrdev; maj++)
1513 			if (cdevsw[maj].d_open == comopen)
1514 				break;
1515 
1516 		KASSERT(maj < nchrdev);
1517 		cn_tab->cn_dev = makedev(maj, sc->sc_dev.dv_unit);
1518 
1519 		printf("%s: console\n", sc->sc_dev.dv_xname);
1520 	}
1521 #endif
1522 
1523 	timeout_set(&sc->sc_diag_tmo, comdiag, sc);
1524 	timeout_set(&sc->sc_dtr_tmo, com_raisedtr, sc);
1525 	sc->sc_si = softintr_establish(IPL_TTY, comsoft, sc);
1526 	if (sc->sc_si == NULL)
1527 		panic("%s: can't establish soft interrupt",
1528 		    sc->sc_dev.dv_xname);
1529 
1530 	/*
1531 	 * If there are no enable/disable functions, assume the device
1532 	 * is always enabled.
1533 	 */
1534 	if (!sc->enable)
1535 		sc->enabled = 1;
1536 
1537 #ifdef COM_CONSOLE
1538 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE))
1539 		com_enable_debugport(sc);
1540 #endif
1541 }
1542 
1543 void
1544 com_fifo_probe(struct com_softc *sc)
1545 {
1546 	u_int8_t fifo, ier;
1547 	int timo, len;
1548 
1549 	if (!ISSET(sc->sc_hwflags, COM_HW_FIFO))
1550 		return;
1551 
1552 	ier = 0;
1553 	com_write_reg(sc, com_ier, ier);
1554 	com_write_reg(sc, com_lcr, LCR_DLAB);
1555 	com_write_reg(sc, com_dlbl, 3);
1556 	com_write_reg(sc, com_dlbh, 0);
1557 	com_write_reg(sc, com_lcr, LCR_PNONE | LCR_8BITS);
1558 	com_write_reg(sc, com_mcr, MCR_LOOPBACK);
1559 
1560 	fifo = FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST;
1561 	if (sc->sc_uarttype == COM_UART_TI16750)
1562 		fifo |= FIFO_ENABLE_64BYTE;
1563 
1564 	com_write_reg(sc, com_fifo, fifo);
1565 
1566 	for (len = 0; len < 256; len++) {
1567 		com_write_reg(sc, com_data, (len + 1));
1568 		timo = 2000;
1569 		while (!ISSET(com_read_reg(sc, com_lsr),
1570 		    LSR_TXRDY) && --timo)
1571 			delay(1);
1572 		if (!timo)
1573 			break;
1574 	}
1575 
1576 	delay(100);
1577 
1578 	for (len = 0; len < 256; len++) {
1579 		timo = 2000;
1580 		while (!ISSET(com_read_reg(sc, com_lsr),
1581 		    LSR_RXRDY) && --timo)
1582 			delay(1);
1583 		if (!timo || com_read_reg(sc, com_data) != (len + 1))
1584 			break;
1585 	}
1586 
1587 	/* For safety, always use the smaller value. */
1588 	if (sc->sc_fifolen > len) {
1589 		printf("%s: probed fifo depth: %d bytes\n",
1590 		    sc->sc_dev.dv_xname, len);
1591 		sc->sc_fifolen = len;
1592 	}
1593 }
1594 
1595 uint8_t
1596 com_read_reg(struct com_softc *sc, bus_size_t reg)
1597 {
1598 	reg <<= sc->sc_reg_shift;
1599 
1600 	if (sc->sc_reg_width == 4)
1601 		return bus_space_read_4(sc->sc_iot, sc->sc_ioh, reg);
1602 	else
1603 		return bus_space_read_1(sc->sc_iot, sc->sc_ioh, reg);
1604 }
1605 
1606 void
1607 com_write_reg(struct com_softc *sc, bus_size_t reg, uint8_t value)
1608 {
1609 	reg <<= sc->sc_reg_shift;
1610 
1611 	if (sc->sc_reg_width == 4)
1612 		return bus_space_write_4(sc->sc_iot, sc->sc_ioh, reg, value);
1613 	else
1614 		return bus_space_write_1(sc->sc_iot, sc->sc_ioh, reg, value);
1615 }
1616 
1617 #ifdef COM_CONSOLE
1618 
1619 u_char comcons_reg_width;
1620 u_char comcons_reg_shift;
1621 
1622 uint8_t
1623 comcn_read_reg(bus_size_t reg)
1624 {
1625 	reg <<= comcons_reg_shift;
1626 
1627 	if (comcons_reg_width == 4)
1628 		return bus_space_read_4(comconsiot, comconsioh, reg);
1629 	else
1630 		return bus_space_read_1(comconsiot, comconsioh, reg);
1631 }
1632 
1633 void
1634 comcn_write_reg(bus_size_t reg, uint8_t value)
1635 {
1636 	reg <<= comcons_reg_shift;
1637 
1638 	if (comcons_reg_width == 4)
1639 		return bus_space_write_4(comconsiot, comconsioh, reg, value);
1640 	else
1641 		return bus_space_write_1(comconsiot, comconsioh, reg, value);
1642 }
1643 
1644 #endif
1645