xref: /netbsd-src/sys/dev/ic/com.c (revision ae1bfcddc410612bc8c58b807e1830becb69a24c)
1 /*-
2  * Copyright (c) 1993, 1994 Charles Hannum.
3  * Copyright (c) 1991 The Regents of the University of California.
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. All advertising materials mentioning features or use of this software
15  *    must display the following acknowledgement:
16  *	This product includes software developed by the University of
17  *	California, Berkeley and its contributors.
18  * 4. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  *	from: @(#)com.c	7.5 (Berkeley) 5/16/91
35  *	$Id: com.c,v 1.31 1994/04/10 10:29:06 cgd Exp $
36  */
37 
38 /*
39  * COM driver, based on HP dca driver
40  * uses National Semiconductor NS16450/NS16550AF UART
41  */
42 #include "com.h"
43 
44 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/ioctl.h>
47 #include <sys/select.h>
48 #include <sys/tty.h>
49 #include <sys/proc.h>
50 #include <sys/user.h>
51 #include <sys/conf.h>
52 #include <sys/file.h>
53 #include <sys/uio.h>
54 #include <sys/kernel.h>
55 #include <sys/syslog.h>
56 #include <sys/types.h>
57 #include <sys/device.h>
58 
59 #include <machine/cpu.h>
60 #include <machine/pio.h>
61 
62 #include <i386/isa/isavar.h>
63 #include <i386/isa/comreg.h>
64 #include <i386/isa/ic/ns16550.h>
65 
66 struct com_softc {
67 	struct device sc_dev;
68 	struct intrhand sc_ih;
69 
70 	u_short sc_iobase;
71 	u_char sc_hwflags;
72 #define	COM_HW_NOIEN	0x01
73 #define	COM_HW_FIFO	0x02
74 #define	COM_HW_CONSOLE	0x40
75 	u_char sc_swflags;
76 #define	COM_SW_SOFTCAR	0x01
77 #define	COM_SW_CLOCAL	0x02
78 #define	COM_SW_CRTSCTS	0x04
79 #define	COM_SW_MDMBUF	0x08
80 	u_char sc_msr, sc_mcr;
81 };
82 /* XXXX should be in com_softc, but not ready for that yet */
83 struct	tty *com_tty[NCOM];
84 
85 int comprobe();
86 void comattach();
87 int comopen __P((dev_t, int, int, struct proc *));
88 int comclose __P((dev_t, int, int, struct proc *));
89 int comintr __P((struct com_softc *));
90 int comparam __P((struct tty *, struct termios *));
91 void comstart __P((struct tty *));
92 
93 struct cfdriver comcd = {
94 	NULL, "com", comprobe, comattach, DV_TTY, sizeof(struct com_softc)
95 };
96 
97 int	comdefaultrate = TTYDEF_SPEED;
98 #ifdef COMCONSOLE
99 int	comconsole = COMCONSOLE;
100 #else
101 int	comconsole = -1;
102 #endif
103 int	comconsinit;
104 int	commajor;
105 
106 #ifdef KGDB
107 #include <machine/remote-sl.h>
108 extern int kgdb_dev;
109 extern int kgdb_rate;
110 extern int kgdb_debug_init;
111 #endif
112 
113 #define	COMUNIT(x)	(minor(x))
114 
115 #define	bis(c, b)	do { const register u_short com_ad = (c); \
116 			     outb(com_ad, inb(com_ad) | (b)); } while(0)
117 #define	bic(c, b)	do { const register u_short com_ad = (c); \
118 			     outb(com_ad, inb(com_ad) & ~(b)); } while(0)
119 
120 int
121 comspeed(speed)
122 	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((COM_FREQ / 16), speed);
133 	if (x <= 0)
134 		return -1;
135 	err = divrnd((COM_FREQ / 16) * 1000, 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(n, q)
143 }
144 
145 int
146 comprobe1(iobase)
147 	u_short iobase;
148 {
149 
150 	/* force access to id reg */
151 	outb(iobase + com_cfcr, 0);
152 	outb(iobase + com_iir, 0);
153 	if (inb(iobase + com_iir) & 0x38)
154 		return 0;
155 
156 	return 1;
157 }
158 
159 int
160 comprobe(parent, self, aux)
161 	struct device *parent, *self;
162 	void *aux;
163 {
164 	struct com_softc *sc = (void *)self;
165 	struct isa_attach_args *ia = aux;
166 	u_short iobase = ia->ia_iobase;
167 
168 	if (!comprobe1(iobase))
169 		return 0;
170 
171 	ia->ia_iosize = COM_NPORTS;
172 	ia->ia_msize = 0;
173 	return 1;
174 }
175 
176 void
177 comattach(parent, self, aux)
178 	struct device *parent, *self;
179 	void *aux;
180 {
181 	struct com_softc *sc = (void *)self;
182 	struct isa_attach_args *ia = aux;
183 	struct cfdata *cf = sc->sc_dev.dv_cfdata;
184 	u_short iobase = ia->ia_iobase;
185 	struct tty *tp;
186 
187 	sc->sc_iobase = iobase;
188 	sc->sc_hwflags = cf->cf_flags & COM_HW_NOIEN;
189 	sc->sc_swflags = 0;
190 
191 	if (sc->sc_dev.dv_unit == comconsole)
192 		delay(1000);
193 
194 	/* look for a NS 16550AF UART with FIFOs */
195 	outb(iobase + com_fifo,
196 	    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_14);
197 	delay(100);
198 	if ((inb(iobase + com_iir) & IIR_FIFO_MASK) == IIR_FIFO_MASK)
199 		if ((inb(iobase + com_fifo) & FIFO_TRIGGER_14) == FIFO_TRIGGER_14) {
200 			sc->sc_hwflags |= COM_HW_FIFO;
201 			printf(": ns16550a, working fifo\n");
202 		} else
203 			printf(": ns82550 or ns16550, broken fifo\n");
204 	else
205 		printf(": ns82450 or ns16450, no fifo\n");
206 	outb(iobase + com_fifo, 0);
207 
208 	/* disable interrupts */
209 	outb(iobase + com_ier, 0);
210 	outb(iobase + com_mcr, 0);
211 
212 	if (!parent) {	/* XXX no master */
213 		sc->sc_ih.ih_fun = comintr;
214 		sc->sc_ih.ih_arg = sc;
215 		sc->sc_ih.ih_level = IPL_TTY;
216 		intr_establish(ia->ia_irq, &sc->sc_ih);
217 	}
218 
219 #ifdef KGDB
220 	if (kgdb_dev == makedev(commajor, unit)) {
221 		if (comconsole == unit)
222 			kgdb_dev = -1;	/* can't debug over console port */
223 		else {
224 			(void) cominit(unit, kgdb_rate);
225 			if (kgdb_debug_init) {
226 				/*
227 				 * Print prefix of device name,
228 				 * let kgdb_connect print the rest.
229 				 */
230 				printf("%s: ", sc->sc_dev.dv_xname);
231 				kgdb_connect(1);
232 			} else
233 				printf("%s: kgdb enabled\n",
234 				    sc->sc_dev.dv_xname);
235 		}
236 	}
237 #endif
238 
239 	if (sc->sc_dev.dv_unit == comconsole) {
240 		/*
241 		 * Need to reset baud rate, etc. of next print so reset
242 		 * comconsinit.  Also make sure console is always "hardwired".
243 		 */
244 		comconsinit = 0;
245 		sc->sc_hwflags |= COM_HW_CONSOLE;
246 		sc->sc_swflags |= COM_SW_SOFTCAR;
247 	}
248 }
249 
250 int
251 comopen(dev, flag, mode, p)
252 	dev_t dev;
253 	int flag, mode;
254 	struct proc *p;
255 {
256 	int unit = COMUNIT(dev);
257 	struct com_softc *sc;
258 	u_short iobase;
259 	struct tty *tp;
260 	int s;
261 	int error = 0;
262 
263 	if (unit >= comcd.cd_ndevs)
264 		return ENXIO;
265 	sc = comcd.cd_devs[unit];
266 	if (!sc)
267 		return ENXIO;
268 
269 	s = spltty();
270 
271 	if (!com_tty[unit])
272 		tp = com_tty[unit] = ttymalloc();
273 	else
274 		tp = com_tty[unit];
275 
276 	tp->t_oproc = comstart;
277 	tp->t_param = comparam;
278 	tp->t_dev = dev;
279 	if ((tp->t_state & TS_ISOPEN) == 0) {
280 		tp->t_state |= TS_WOPEN;
281 		ttychars(tp);
282 		tp->t_iflag = TTYDEF_IFLAG;
283 		tp->t_oflag = TTYDEF_OFLAG;
284 		tp->t_cflag = TTYDEF_CFLAG;
285 		if (sc->sc_swflags & COM_SW_CLOCAL)
286 			tp->t_cflag |= CLOCAL;
287 		if (sc->sc_swflags & COM_SW_CRTSCTS)
288 			tp->t_cflag |= CRTSCTS;
289 		if (sc->sc_swflags & COM_SW_MDMBUF)
290 			tp->t_cflag |= MDMBUF;
291 		tp->t_lflag = TTYDEF_LFLAG;
292 		tp->t_ispeed = tp->t_ospeed = comdefaultrate;
293 		comparam(tp, &tp->t_termios);
294 		ttsetwater(tp);
295 
296 		iobase = sc->sc_iobase;
297 		/* flush any pending I/O */
298 		if (sc->sc_hwflags & COM_HW_FIFO)
299 			outb(iobase + com_fifo,
300 			    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST |
301 			    FIFO_TRIGGER_8);
302 		(void) inb(iobase + com_lsr);
303 		(void) inb(iobase + com_data);
304 		/* you turn me on, baby */
305 		sc->sc_mcr = MCR_DTR | MCR_RTS;
306 		if (!(sc->sc_hwflags & COM_HW_NOIEN))
307 			sc->sc_mcr |= MCR_IENABLE;
308 		outb(iobase + com_mcr, sc->sc_mcr);
309 		outb(iobase + com_ier,
310 		    IER_ERXRDY | IER_ETXRDY | IER_ERLS | IER_EMSC);
311 
312 		sc->sc_msr = inb(iobase + com_msr);
313 		if (sc->sc_swflags & COM_SW_SOFTCAR || sc->sc_msr & MSR_DCD ||
314 		    tp->t_lflag&MDMBUF)
315 			tp->t_state |= TS_CARR_ON;
316 		else
317 			tp->t_state &= ~TS_CARR_ON;
318 	} else if (tp->t_state&TS_XCLUDE && p->p_ucred->cr_uid != 0) {
319 		splx(s);
320 		return EBUSY;
321 	}
322 
323 	/* wait for carrier if necessary */
324 	if ((flag & O_NONBLOCK) == 0)
325 		while ((tp->t_cflag & CLOCAL) == 0 &&
326 		    (tp->t_state & TS_CARR_ON) == 0) {
327 			tp->t_state |= TS_WOPEN;
328 			error = ttysleep(tp, (caddr_t)&tp->t_rawq,
329 			    TTIPRI | PCATCH, ttopen, 0);
330 			if (error) {
331 				/* XXX should turn off chip if we're the
332 				   only waiter */
333 				splx(s);
334 				return error;
335 			}
336 		}
337 	splx(s);
338 
339 	return (*linesw[tp->t_line].l_open)(dev, tp);
340 }
341 
342 int
343 comclose(dev, flag, mode, p)
344 	dev_t dev;
345 	int flag, mode;
346 	struct proc *p;
347 {
348 	int unit = COMUNIT(dev);
349 	struct com_softc *sc = comcd.cd_devs[unit];
350 	u_short iobase = sc->sc_iobase;
351 	struct tty *tp = com_tty[unit];
352 
353 	(*linesw[tp->t_line].l_close)(tp, flag);
354 #ifdef KGDB
355 	/* do not disable interrupts if debugging */
356 	if (kgdb_dev != makedev(commajor, unit))
357 #endif
358 	{
359 		bic(iobase + com_cfcr, CFCR_SBREAK);
360 		outb(iobase + com_ier, 0);
361 		if (tp->t_cflag & HUPCL &&
362 		    (sc->sc_swflags & COM_SW_SOFTCAR) == 0)
363 			/* XXX perhaps only clear DTR */
364 			outb(iobase + com_mcr, 0);
365 	}
366 	ttyclose(tp);
367 #ifdef notyet /* XXXX */
368 	if (unit != comconsole) {
369 		ttyfree(tp);
370 		com_tty[unit] = (struct tty *)NULL;
371 	}
372 #endif
373 	return 0;
374 }
375 
376 int
377 comread(dev, uio, flag)
378 	dev_t dev;
379 	struct uio *uio;
380 	int flag;
381 {
382 	struct tty *tp = com_tty[COMUNIT(dev)];
383 
384 	return ((*linesw[tp->t_line].l_read)(tp, uio, flag));
385 }
386 
387 int
388 comwrite(dev, uio, flag)
389 	dev_t dev;
390 	struct uio *uio;
391 	int flag;
392 {
393 	struct tty *tp = com_tty[COMUNIT(dev)];
394 
395 	return ((*linesw[tp->t_line].l_write)(tp, uio, flag));
396 }
397 
398 static u_char
399 tiocm_xxx2mcr(data)
400 	int data;
401 {
402 	u_char m = 0;
403 
404 	if (data & TIOCM_DTR)
405 		m |= MCR_DTR;
406 	if (data & TIOCM_RTS)
407 		m |= MCR_RTS;
408 	return m;
409 }
410 
411 int
412 comioctl(dev, cmd, data, flag, p)
413 	dev_t dev;
414 	int cmd;
415 	caddr_t data;
416 	int flag;
417 	struct proc *p;
418 {
419 	int unit = COMUNIT(dev);
420 	struct com_softc *sc = comcd.cd_devs[unit];
421 	u_short iobase = sc->sc_iobase;
422 	struct tty *tp = com_tty[unit];
423 	int error;
424 
425 	error = (*linesw[tp->t_line].l_ioctl)(tp, cmd, data, flag, p);
426 	if (error >= 0)
427 		return error;
428 	error = ttioctl(tp, cmd, data, flag, p);
429 	if (error >= 0)
430 		return error;
431 
432 	switch (cmd) {
433 	case TIOCSBRK:
434 		bis(iobase + com_cfcr, CFCR_SBREAK);
435 		break;
436 	case TIOCCBRK:
437 		bic(iobase + com_cfcr, CFCR_SBREAK);
438 		break;
439 	case TIOCSDTR:
440 		outb(iobase + com_mcr, sc->sc_mcr |= (MCR_DTR | MCR_RTS));
441 		break;
442 	case TIOCCDTR:
443 		outb(iobase + com_mcr, sc->sc_mcr &= ~(MCR_DTR | MCR_RTS));
444 		break;
445 	case TIOCMSET:
446 		sc->sc_mcr &= ~(MCR_DTR | MCR_RTS);
447 	case TIOCMBIS:
448 		outb(iobase + com_mcr,
449 		    sc->sc_mcr |= tiocm_xxx2mcr(*(int *)data));
450 		break;
451 	case TIOCMBIC:
452 		outb(iobase + com_mcr,
453 		    sc->sc_mcr &= ~tiocm_xxx2mcr(*(int *)data));
454 		break;
455 	case TIOCMGET: {
456 		u_char m;
457 		int bits = 0;
458 
459 		m = sc->sc_mcr;
460 		if (m & MCR_DTR)
461 			bits |= TIOCM_DTR;
462 		if (m & MCR_RTS)
463 			bits |= TIOCM_RTS;
464 		m = sc->sc_msr;
465 		if (m & MSR_DCD)
466 			bits |= TIOCM_CD;
467 		if (m & MSR_CTS)
468 			bits |= TIOCM_CTS;
469 		if (m & MSR_DSR)
470 			bits |= TIOCM_DSR;
471 		if (m & (MSR_RI | MSR_TERI))
472 			bits |= TIOCM_RI;
473 		if (inb(iobase + com_ier))
474 			bits |= TIOCM_LE;
475 		*(int *)data = bits;
476 		break;
477 	}
478 	case TIOCGFLAGS: {
479 		int bits = 0;
480 
481 		if (sc->sc_swflags & COM_SW_SOFTCAR)
482 			bits |= TIOCFLAG_SOFTCAR;
483 		if (sc->sc_swflags & COM_SW_CLOCAL)
484 			bits |= TIOCFLAG_CLOCAL;
485 		if (sc->sc_swflags & COM_SW_CRTSCTS)
486 			bits |= TIOCFLAG_CRTSCTS;
487 		if (sc->sc_swflags & COM_SW_MDMBUF)
488 			bits |= TIOCFLAG_MDMBUF;
489 
490 		*(int *)data = bits;
491 		break;
492 	}
493 	case TIOCSFLAGS: {
494 		int userbits, driverbits = 0;
495 
496 		error = suser(p->p_ucred, &p->p_acflag);
497 		if (error != 0)
498 			return(EPERM);
499 
500 		userbits = *(int *)data;
501 		if ((userbits & TIOCFLAG_SOFTCAR) ||
502 		    (sc->sc_hwflags & COM_HW_CONSOLE))
503 			driverbits |= COM_SW_SOFTCAR;
504 		if (userbits & TIOCFLAG_CLOCAL)
505 			driverbits |= COM_SW_CLOCAL;
506 		if (userbits & TIOCFLAG_CRTSCTS)
507 			driverbits |= COM_SW_CRTSCTS;
508 		if (userbits & TIOCFLAG_MDMBUF)
509 			driverbits |= COM_SW_MDMBUF;
510 
511 		sc->sc_swflags = driverbits;
512 		break;
513 	}
514 	default:
515 		return ENOTTY;
516 	}
517 
518 	return 0;
519 }
520 
521 int
522 comparam(tp, t)
523 	struct tty *tp;
524 	struct termios *t;
525 {
526 	struct com_softc *sc = comcd.cd_devs[COMUNIT(tp->t_dev)];
527 	u_short iobase = sc->sc_iobase;
528 	int ospeed = comspeed(t->c_ospeed);
529 	u_char cfcr;
530 	int s;
531 
532 	/* check requested parameters */
533 	if (ospeed < 0 || (t->c_ispeed && t->c_ispeed != t->c_ospeed))
534 		return EINVAL;
535 
536 	switch (t->c_cflag & CSIZE) {
537 	case CS5:
538 		cfcr = CFCR_5BITS;
539 		break;
540 	case CS6:
541 		cfcr = CFCR_6BITS;
542 		break;
543 	case CS7:
544 		cfcr = CFCR_7BITS;
545 		break;
546 	case CS8:
547 		cfcr = CFCR_8BITS;
548 		break;
549 	}
550 	if (t->c_cflag & PARENB) {
551 		cfcr |= CFCR_PENAB;
552 		if ((t->c_cflag & PARODD) == 0)
553 			cfcr |= CFCR_PEVEN;
554 	}
555 	if (t->c_cflag & CSTOPB)
556 		cfcr |= CFCR_STOPB;
557 
558 	s = spltty();
559 
560 	/* and copy to tty */
561 	tp->t_ispeed = t->c_ispeed;
562 	tp->t_ospeed = t->c_ospeed;
563 	tp->t_cflag = t->c_cflag;
564 
565 	if (ospeed == 0)
566 		outb(iobase + com_mcr, sc->sc_mcr &= ~MCR_DTR);
567 	else
568 		outb(iobase + com_mcr, sc->sc_mcr |= MCR_DTR);
569 
570 	outb(iobase + com_cfcr, cfcr | CFCR_DLAB);
571 	outb(iobase + com_dlbl, ospeed);
572 	outb(iobase + com_dlbh, ospeed>>8);
573 	outb(iobase + com_cfcr, cfcr);
574 
575 	/* When not using CRTSCTS, RTS follows DTR. */
576 	if ((t->c_cflag & CRTSCTS) == 0) {
577 		if (sc->sc_mcr & MCR_DTR) {
578 			if ((sc->sc_mcr & MCR_RTS) == 0)
579 				outb(iobase + com_mcr, sc->sc_mcr |= MCR_RTS);
580 		} else {
581 			if (sc->sc_mcr & MCR_RTS)
582 				outb(iobase + com_mcr, sc->sc_mcr &= ~MCR_RTS);
583 		}
584 	}
585 
586 	/*
587 	 * If CTS is off and CRTSCTS is changed, we must toggle TS_TTSTOP.
588 	 * XXX should be done at tty layer.
589 	 */
590 	if ((sc->sc_msr & MSR_CTS) == 0 &&
591 	    (tp->t_cflag & CRTSCTS) != (t->c_cflag & CRTSCTS)) {
592 		if ((t->c_cflag & CRTSCTS) == 0) {
593 			tp->t_state &= ~TS_TTSTOP;
594 			ttstart(tp);
595 		} else
596 			tp->t_state |= TS_TTSTOP;
597 	}
598 
599 	/*
600 	 * If DCD is off and MDMBUF is changed, we must toggle TS_TTSTOP.
601 	 * XXX should be done at tty layer.
602 	 */
603 	if ((sc->sc_swflags & COM_SW_SOFTCAR) == 0 &&
604 	    (sc->sc_msr & MSR_DCD) == 0 &&
605 	    (tp->t_cflag & MDMBUF) != (t->c_cflag & MDMBUF)) {
606 		if ((t->c_cflag & MDMBUF) == 0) {
607 			tp->t_state &= ~TS_TTSTOP;
608 			ttstart(tp);
609 		} else
610 			tp->t_state |= TS_TTSTOP;
611 	}
612 
613 	splx(s);
614 	return 0;
615 }
616 
617 void
618 comstart(tp)
619 	struct tty *tp;
620 {
621 	struct com_softc *sc = comcd.cd_devs[COMUNIT(tp->t_dev)];
622 	u_short iobase = sc->sc_iobase;
623 	int s;
624 
625 	s = spltty();
626 	if (tp->t_state & (TS_TTSTOP | TS_BUSY))
627 		goto out;
628 #if 0 /* XXXX I think this is handled adequately by commint() and comparam(). */
629 	if (tp->t_cflag & CRTSCTS && (sc->sc_mcr & MSR_CTS) == 0)
630 		goto out;
631 #endif
632 	if (tp->t_outq.c_cc <= tp->t_lowat) {
633 		if (tp->t_state & TS_ASLEEP) {
634 			tp->t_state &= ~TS_ASLEEP;
635 			wakeup((caddr_t)&tp->t_outq);
636 		}
637 		selwakeup(&tp->t_wsel);
638 	}
639 	if (tp->t_outq.c_cc == 0)
640 		goto out;
641 	tp->t_state |= TS_BUSY;
642 	if ((inb(iobase + com_lsr) & LSR_TXRDY) == 0)
643 		goto out;
644 	if (sc->sc_hwflags & COM_HW_FIFO) {
645 		u_char buffer[16], *cp = buffer;
646 		int n = q_to_b(&tp->t_outq, cp, sizeof buffer);
647 		do {
648 			outb(iobase + com_data, *cp++);
649 		} while (--n);
650 	} else
651 		outb(iobase + com_data, getc(&tp->t_outq));
652 out:
653 	splx(s);
654 }
655 
656 /*
657  * Stop output on a line.
658  */
659 void
660 comstop(tp, flag)
661 	struct tty *tp;
662 {
663 	int s;
664 
665 	s = spltty();
666 	if (tp->t_state & TS_BUSY)
667 		if ((tp->t_state & TS_TTSTOP) == 0)
668 			tp->t_state |= TS_FLUSH;
669 	splx(s);
670 }
671 
672 static inline void
673 comeint(sc, stat)
674 	struct com_softc *sc;
675 	int stat;
676 {
677 	u_short iobase = sc->sc_iobase;
678 	int unit = sc->sc_dev.dv_unit;
679 	struct tty *tp = com_tty[unit];
680 	int c;
681 
682 	c = inb(iobase + com_data);
683 	if ((tp->t_state & TS_ISOPEN) == 0) {
684 #ifdef KGDB
685 		/* we don't care about parity errors */
686 		if (((stat & (LSR_BI | LSR_FE | LSR_PE)) == LSR_PE) &&
687 		    kgdb_dev == makedev(commajor, unit) && c == FRAME_END)
688 			kgdb_connect(0); /* trap into kgdb */
689 #endif
690 		return;
691 	}
692 	if (stat & (LSR_BI | LSR_FE))
693 		c |= TTY_FE;
694 	else if (stat & LSR_PE)
695 		c |= TTY_PE;
696 	if (stat & LSR_OE)
697 		log(LOG_WARNING, "%s: silo overflow\n", sc->sc_dev.dv_xname);
698 	/* XXXX put in FIFO and process later */
699 	(*linesw[tp->t_line].l_rint)(c, tp);
700 }
701 
702 static inline void
703 commint(sc)
704 	struct com_softc *sc;
705 {
706 	u_short iobase = sc->sc_iobase;
707 	struct tty *tp = com_tty[sc->sc_dev.dv_unit];
708 	u_char msr, delta;
709 
710 	msr = inb(iobase + com_msr);
711 	delta = msr ^ sc->sc_msr;
712 	sc->sc_msr = msr;
713 
714 	if (delta & MSR_DCD && (sc->sc_swflags & COM_SW_SOFTCAR) == 0) {
715 		if (msr & MSR_DCD)
716 			(void)(*linesw[tp->t_line].l_modem)(tp, 1);
717 		else if ((*linesw[tp->t_line].l_modem)(tp, 0) == 0)
718 			outb(iobase + com_mcr,
719 			    sc->sc_mcr &= ~(MCR_DTR | MCR_RTS));
720 	}
721 	if (delta & MSR_CTS && tp->t_cflag & CRTSCTS) {
722 		/* the line is up and we want to do rts/cts flow control */
723 		if (msr & MSR_CTS) {
724 			tp->t_state &= ~TS_TTSTOP;
725 			ttstart(tp);
726 		} else
727 			tp->t_state |= TS_TTSTOP;
728 	}
729 }
730 
731 int
732 comintr(sc)
733 	struct com_softc *sc;
734 {
735 	u_short iobase = sc->sc_iobase;
736 	struct tty *tp;
737 	u_char code;
738 
739 	code = inb(iobase + com_iir) & IIR_IMASK;
740 	if (code & IIR_NOPEND)
741 		return 0;
742 
743 	for (;;) {
744 		if (code & IIR_RXRDY) {
745 			tp = com_tty[sc->sc_dev.dv_unit];
746 			/* XXXX put in FIFO and process later */
747 			while (code = (inb(iobase + com_lsr) & LSR_RCV_MASK)) {
748 				if (code == LSR_RXRDY) {
749 					code = inb(iobase + com_data);
750 					if (tp->t_state & TS_ISOPEN)
751 						(*linesw[tp->t_line].l_rint)(code, tp);
752 #ifdef KGDB
753 					else {
754 						if (kgdb_dev == makedev(commajor, unit) &&
755 						    code == FRAME_END)
756 							kgdb_connect(0);
757 					}
758 #endif
759 				} else
760 					comeint(sc, code);
761 			}
762 		} else if (code == IIR_TXRDY) {
763 			tp = com_tty[sc->sc_dev.dv_unit];
764 			tp->t_state &= ~TS_BUSY;
765 			if (tp->t_state & TS_FLUSH)
766 				tp->t_state &= ~TS_FLUSH;
767 			else
768 				if (tp->t_line)
769 					(*linesw[tp->t_line].l_start)(tp);
770 				else
771 					comstart(tp);
772 		} else if (code == IIR_MLSC) {
773 			commint(sc);
774 		} else {
775 			log(LOG_WARNING, "%s: weird interrupt: iir=0x%02x\n",
776 			    sc->sc_dev.dv_xname, code);
777 		}
778 		code = inb(iobase + com_iir) & IIR_IMASK;
779 		if (code & IIR_NOPEND)
780 			return 1;
781 	}
782 }
783 
784 /*
785  * Following are all routines needed for COM to act as console
786  */
787 #include <dev/cons.h>
788 
789 comcnprobe(cp)
790 	struct consdev *cp;
791 {
792 
793 	if (!comprobe1(CONADDR)) {
794 		cp->cn_pri = CN_DEAD;
795 		return;
796 	}
797 
798 	/* locate the major number */
799 	for (commajor = 0; commajor < nchrdev; commajor++)
800 		if (cdevsw[commajor].d_open == comopen)
801 			break;
802 
803 	/* initialize required fields */
804 	cp->cn_dev = makedev(commajor, CONUNIT);
805 #ifdef	COMCONSOLE
806 	cp->cn_pri = CN_REMOTE;		/* Force a serial port console */
807 #else
808 	cp->cn_pri = CN_NORMAL;
809 #endif
810 }
811 
812 comcninit(cp)
813 	struct consdev *cp;
814 {
815 
816 	cominit(CONUNIT, comdefaultrate);
817 	comconsole = CONUNIT;
818 	comconsinit = 0;
819 }
820 
821 cominit(unit, rate)
822 	int unit, rate;
823 {
824 	int s = splhigh();
825 	u_short iobase = CONADDR;
826 	u_char stat;
827 
828 	outb(iobase + com_cfcr, CFCR_DLAB);
829 	rate = comspeed(comdefaultrate);
830 	outb(iobase + com_dlbl, rate);
831 	outb(iobase + com_dlbh, rate >> 8);
832 	outb(iobase + com_cfcr, CFCR_8BITS);
833 	outb(iobase + com_ier, IER_ERXRDY | IER_ETXRDY);
834 	outb(iobase + com_fifo, FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_4);
835 	stat = inb(iobase + com_iir);
836 	splx(s);
837 }
838 
839 comcngetc(dev)
840 	dev_t dev;
841 {
842 	int s = splhigh();
843 	u_short iobase = CONADDR;
844 	u_char stat, c;
845 
846 	while (((stat = inb(iobase + com_lsr)) & LSR_RXRDY) == 0)
847 		;
848 	c = inb(iobase + com_data);
849 	stat = inb(iobase + com_iir);
850 	splx(s);
851 	return c;
852 }
853 
854 /*
855  * Console kernel output character routine.
856  */
857 comcnputc(dev, c)
858 	dev_t dev;
859 	int c;
860 {
861 	int s = splhigh();
862 	u_short iobase = CONADDR;
863 	u_char stat;
864 	register int timo;
865 
866 #ifdef KGDB
867 	if (dev != kgdb_dev)
868 #endif
869 	if (comconsinit == 0) {
870 		(void) cominit(COMUNIT(dev), comdefaultrate);
871 		comconsinit = 1;
872 	}
873 	/* wait for any pending transmission to finish */
874 	timo = 50000;
875 	while (((stat = inb(iobase + com_lsr)) & LSR_TXRDY) == 0 && --timo)
876 		;
877 	outb(iobase + com_data, c);
878 	/* wait for this transmission to complete */
879 	timo = 1500000;
880 	while (((stat = inb(iobase + com_lsr)) & LSR_TXRDY) == 0 && --timo)
881 		;
882 	/* clear any interrupts generated by this transmission */
883 	stat = inb(iobase + com_iir);
884 	splx(s);
885 }
886