xref: /netbsd-src/sys/dev/ic/com.c (revision 6ea46cb5e46c49111a6ecf3bcbe3c7e2730fe9f6)
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 1.36 1994/09/16 02:50:39 mycroft 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 	int sc_overflows;
71 	u_short sc_iobase;
72 	u_char sc_hwflags;
73 #define	COM_HW_NOIEN	0x01
74 #define	COM_HW_FIFO	0x02
75 #define	COM_HW_CONSOLE	0x40
76 	u_char sc_swflags;
77 #define	COM_SW_SOFTCAR	0x01
78 #define	COM_SW_CLOCAL	0x02
79 #define	COM_SW_CRTSCTS	0x04
80 #define	COM_SW_MDMBUF	0x08
81 	u_char sc_msr, sc_mcr;
82 };
83 /* XXXX should be in com_softc, but not ready for that yet */
84 struct	tty *com_tty[NCOM];
85 
86 int comprobe();
87 void comattach();
88 int comopen __P((dev_t, int, int, struct proc *));
89 int comclose __P((dev_t, int, int, struct proc *));
90 void comdiag __P((void *));
91 int comintr __P((struct com_softc *));
92 int comparam __P((struct tty *, struct termios *));
93 void comstart __P((struct tty *));
94 
95 struct cfdriver comcd = {
96 	NULL, "com", comprobe, comattach, DV_TTY, sizeof(struct com_softc)
97 };
98 
99 int	comdefaultrate = TTYDEF_SPEED;
100 #ifdef COMCONSOLE
101 int	comconsole = COMCONSOLE;
102 #else
103 int	comconsole = -1;
104 #endif
105 int	comconsinit;
106 int	commajor;
107 
108 #ifdef KGDB
109 #include <machine/remote-sl.h>
110 extern int kgdb_dev;
111 extern int kgdb_rate;
112 extern int kgdb_debug_init;
113 #endif
114 
115 #define	COMUNIT(x)	(minor(x))
116 
117 #define	bis(c, b)	do { const register u_short com_ad = (c); \
118 			     outb(com_ad, inb(com_ad) | (b)); } while(0)
119 #define	bic(c, b)	do { const register u_short com_ad = (c); \
120 			     outb(com_ad, inb(com_ad) & ~(b)); } while(0)
121 
122 int
123 comspeed(speed)
124 	long speed;
125 {
126 #define	divrnd(n, q)	(((n)*2/(q)+1)/2)	/* divide and round off */
127 
128 	int x, err;
129 
130 	if (speed == 0)
131 		return 0;
132 	if (speed < 0)
133 		return -1;
134 	x = divrnd((COM_FREQ / 16), speed);
135 	if (x <= 0)
136 		return -1;
137 	err = divrnd((COM_FREQ / 16) * 1000, speed * x) - 1000;
138 	if (err < 0)
139 		err = -err;
140 	if (err > COM_TOLERANCE)
141 		return -1;
142 	return x;
143 
144 #undef	divrnd(n, q)
145 }
146 
147 int
148 comprobe1(iobase)
149 	u_short iobase;
150 {
151 
152 	/* force access to id reg */
153 	outb(iobase + com_cfcr, 0);
154 	outb(iobase + com_iir, 0);
155 	if (inb(iobase + com_iir) & 0x38)
156 		return 0;
157 
158 	return 1;
159 }
160 
161 int
162 comprobe(parent, self, aux)
163 	struct device *parent, *self;
164 	void *aux;
165 {
166 	struct com_softc *sc = (void *)self;
167 	struct isa_attach_args *ia = aux;
168 	u_short iobase = ia->ia_iobase;
169 
170 	if (!comprobe1(iobase))
171 		return 0;
172 
173 	ia->ia_iosize = COM_NPORTS;
174 	ia->ia_msize = 0;
175 	return 1;
176 }
177 
178 void
179 comattach(parent, self, aux)
180 	struct device *parent, *self;
181 	void *aux;
182 {
183 	struct com_softc *sc = (void *)self;
184 	struct isa_attach_args *ia = aux;
185 	struct cfdata *cf = sc->sc_dev.dv_cfdata;
186 	u_short iobase = ia->ia_iobase;
187 	struct tty *tp;
188 
189 	sc->sc_iobase = iobase;
190 	sc->sc_hwflags = cf->cf_flags & COM_HW_NOIEN;
191 	sc->sc_swflags = 0;
192 
193 	if (sc->sc_dev.dv_unit == comconsole)
194 		delay(1000);
195 
196 	/* look for a NS 16550AF UART with FIFOs */
197 	outb(iobase + com_fifo,
198 	    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_14);
199 	delay(100);
200 	if ((inb(iobase + com_iir) & IIR_FIFO_MASK) == IIR_FIFO_MASK)
201 		if ((inb(iobase + com_fifo) & FIFO_TRIGGER_14) == FIFO_TRIGGER_14) {
202 			sc->sc_hwflags |= COM_HW_FIFO;
203 			printf(": ns16550a, working fifo\n");
204 		} else
205 			printf(": ns82550 or ns16550, broken fifo\n");
206 	else
207 		printf(": ns82450 or ns16450, no fifo\n");
208 	outb(iobase + com_fifo, 0);
209 
210 	/* disable interrupts */
211 	outb(iobase + com_ier, 0);
212 	outb(iobase + com_mcr, 0);
213 
214 	if (!parent) {	/* XXX no master */
215 		sc->sc_ih.ih_fun = comintr;
216 		sc->sc_ih.ih_arg = sc;
217 		sc->sc_ih.ih_level = IPL_TTY;
218 		intr_establish(ia->ia_irq, &sc->sc_ih);
219 	}
220 
221 #ifdef KGDB
222 	if (kgdb_dev == makedev(commajor, unit)) {
223 		if (comconsole == unit)
224 			kgdb_dev = -1;	/* can't debug over console port */
225 		else {
226 			(void) cominit(unit, kgdb_rate);
227 			if (kgdb_debug_init) {
228 				/*
229 				 * Print prefix of device name,
230 				 * let kgdb_connect print the rest.
231 				 */
232 				printf("%s: ", sc->sc_dev.dv_xname);
233 				kgdb_connect(1);
234 			} else
235 				printf("%s: kgdb enabled\n",
236 				    sc->sc_dev.dv_xname);
237 		}
238 	}
239 #endif
240 
241 	if (sc->sc_dev.dv_unit == comconsole) {
242 		/*
243 		 * Need to reset baud rate, etc. of next print so reset
244 		 * comconsinit.  Also make sure console is always "hardwired".
245 		 */
246 		comconsinit = 0;
247 		sc->sc_hwflags |= COM_HW_CONSOLE;
248 		sc->sc_swflags |= COM_SW_SOFTCAR;
249 	}
250 }
251 
252 int
253 comopen(dev, flag, mode, p)
254 	dev_t dev;
255 	int flag, mode;
256 	struct proc *p;
257 {
258 	int unit = COMUNIT(dev);
259 	struct com_softc *sc;
260 	u_short iobase;
261 	struct tty *tp;
262 	int s;
263 	int error = 0;
264 
265 	if (unit >= comcd.cd_ndevs)
266 		return ENXIO;
267 	sc = comcd.cd_devs[unit];
268 	if (!sc)
269 		return ENXIO;
270 
271 	s = spltty();
272 
273 	if (!com_tty[unit])
274 		tp = com_tty[unit] = ttymalloc();
275 	else
276 		tp = com_tty[unit];
277 
278 	tp->t_oproc = comstart;
279 	tp->t_param = comparam;
280 	tp->t_dev = dev;
281 	if ((tp->t_state & TS_ISOPEN) == 0) {
282 		tp->t_state |= TS_WOPEN;
283 		ttychars(tp);
284 		tp->t_iflag = TTYDEF_IFLAG;
285 		tp->t_oflag = TTYDEF_OFLAG;
286 		tp->t_cflag = TTYDEF_CFLAG;
287 		if (sc->sc_swflags & COM_SW_CLOCAL)
288 			tp->t_cflag |= CLOCAL;
289 		if (sc->sc_swflags & COM_SW_CRTSCTS)
290 			tp->t_cflag |= CRTSCTS;
291 		if (sc->sc_swflags & COM_SW_MDMBUF)
292 			tp->t_cflag |= MDMBUF;
293 		tp->t_lflag = TTYDEF_LFLAG;
294 		tp->t_ispeed = tp->t_ospeed = comdefaultrate;
295 		comparam(tp, &tp->t_termios);
296 		ttsetwater(tp);
297 
298 		iobase = sc->sc_iobase;
299 		/* Set the FIFO threshold based on the receive speed. */
300 		if (sc->sc_hwflags & COM_HW_FIFO)
301 			outb(iobase + com_fifo,
302 			    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST |
303 			    (tp->t_ispeed <= 1200 ? FIFO_TRIGGER_1 : FIFO_TRIGGER_8));
304 		/* flush any pending I/O */
305 		(void) inb(iobase + com_lsr);
306 		(void) inb(iobase + com_data);
307 		/* you turn me on, baby */
308 		sc->sc_mcr = MCR_DTR | MCR_RTS;
309 		if (!(sc->sc_hwflags & COM_HW_NOIEN))
310 			sc->sc_mcr |= MCR_IENABLE;
311 		outb(iobase + com_mcr, sc->sc_mcr);
312 		outb(iobase + com_ier,
313 		    IER_ERXRDY | IER_ETXRDY | IER_ERLS | IER_EMSC);
314 
315 		sc->sc_msr = inb(iobase + com_msr);
316 		if (sc->sc_swflags & COM_SW_SOFTCAR || sc->sc_msr & MSR_DCD ||
317 		    tp->t_cflag & MDMBUF)
318 			tp->t_state |= TS_CARR_ON;
319 		else
320 			tp->t_state &= ~TS_CARR_ON;
321 	} else if (tp->t_state&TS_XCLUDE && p->p_ucred->cr_uid != 0) {
322 		splx(s);
323 		return EBUSY;
324 	}
325 
326 	/* wait for carrier if necessary */
327 	if ((flag & O_NONBLOCK) == 0)
328 		while ((tp->t_cflag & CLOCAL) == 0 &&
329 		    (tp->t_state & TS_CARR_ON) == 0) {
330 			tp->t_state |= TS_WOPEN;
331 			error = ttysleep(tp, (caddr_t)&tp->t_rawq,
332 			    TTIPRI | PCATCH, ttopen, 0);
333 			if (error) {
334 				/* XXX should turn off chip if we're the
335 				   only waiter */
336 				splx(s);
337 				return error;
338 			}
339 		}
340 	splx(s);
341 
342 	return (*linesw[tp->t_line].l_open)(dev, tp);
343 }
344 
345 int
346 comclose(dev, flag, mode, p)
347 	dev_t dev;
348 	int flag, mode;
349 	struct proc *p;
350 {
351 	int unit = COMUNIT(dev);
352 	struct com_softc *sc = comcd.cd_devs[unit];
353 	u_short iobase = sc->sc_iobase;
354 	struct tty *tp = com_tty[unit];
355 
356 	(*linesw[tp->t_line].l_close)(tp, flag);
357 #ifdef KGDB
358 	/* do not disable interrupts if debugging */
359 	if (kgdb_dev != makedev(commajor, unit))
360 #endif
361 	{
362 		bic(iobase + com_cfcr, CFCR_SBREAK);
363 		outb(iobase + com_ier, 0);
364 		if (tp->t_cflag & HUPCL &&
365 		    (sc->sc_swflags & COM_SW_SOFTCAR) == 0)
366 			/* XXX perhaps only clear DTR */
367 			outb(iobase + com_mcr, 0);
368 	}
369 	ttyclose(tp);
370 #ifdef notyet /* XXXX */
371 	if (unit != comconsole) {
372 		ttyfree(tp);
373 		com_tty[unit] = (struct tty *)NULL;
374 	}
375 #endif
376 	return 0;
377 }
378 
379 int
380 comread(dev, uio, flag)
381 	dev_t dev;
382 	struct uio *uio;
383 	int flag;
384 {
385 	struct tty *tp = com_tty[COMUNIT(dev)];
386 
387 	return ((*linesw[tp->t_line].l_read)(tp, uio, flag));
388 }
389 
390 int
391 comwrite(dev, uio, flag)
392 	dev_t dev;
393 	struct uio *uio;
394 	int flag;
395 {
396 	struct tty *tp = com_tty[COMUNIT(dev)];
397 
398 	return ((*linesw[tp->t_line].l_write)(tp, uio, flag));
399 }
400 
401 static u_char
402 tiocm_xxx2mcr(data)
403 	int data;
404 {
405 	u_char m = 0;
406 
407 	if (data & TIOCM_DTR)
408 		m |= MCR_DTR;
409 	if (data & TIOCM_RTS)
410 		m |= MCR_RTS;
411 	return m;
412 }
413 
414 int
415 comioctl(dev, cmd, data, flag, p)
416 	dev_t dev;
417 	int cmd;
418 	caddr_t data;
419 	int flag;
420 	struct proc *p;
421 {
422 	int unit = COMUNIT(dev);
423 	struct com_softc *sc = comcd.cd_devs[unit];
424 	u_short iobase = sc->sc_iobase;
425 	struct tty *tp = com_tty[unit];
426 	int error;
427 
428 	error = (*linesw[tp->t_line].l_ioctl)(tp, cmd, data, flag, p);
429 	if (error >= 0)
430 		return error;
431 	error = ttioctl(tp, cmd, data, flag, p);
432 	if (error >= 0)
433 		return error;
434 
435 	switch (cmd) {
436 	case TIOCSBRK:
437 		bis(iobase + com_cfcr, CFCR_SBREAK);
438 		break;
439 	case TIOCCBRK:
440 		bic(iobase + com_cfcr, CFCR_SBREAK);
441 		break;
442 	case TIOCSDTR:
443 		outb(iobase + com_mcr, sc->sc_mcr |= (MCR_DTR | MCR_RTS));
444 		break;
445 	case TIOCCDTR:
446 		outb(iobase + com_mcr, sc->sc_mcr &= ~(MCR_DTR | MCR_RTS));
447 		break;
448 	case TIOCMSET:
449 		sc->sc_mcr &= ~(MCR_DTR | MCR_RTS);
450 	case TIOCMBIS:
451 		outb(iobase + com_mcr,
452 		    sc->sc_mcr |= tiocm_xxx2mcr(*(int *)data));
453 		break;
454 	case TIOCMBIC:
455 		outb(iobase + com_mcr,
456 		    sc->sc_mcr &= ~tiocm_xxx2mcr(*(int *)data));
457 		break;
458 	case TIOCMGET: {
459 		u_char m;
460 		int bits = 0;
461 
462 		m = sc->sc_mcr;
463 		if (m & MCR_DTR)
464 			bits |= TIOCM_DTR;
465 		if (m & MCR_RTS)
466 			bits |= TIOCM_RTS;
467 		m = sc->sc_msr;
468 		if (m & MSR_DCD)
469 			bits |= TIOCM_CD;
470 		if (m & MSR_CTS)
471 			bits |= TIOCM_CTS;
472 		if (m & MSR_DSR)
473 			bits |= TIOCM_DSR;
474 		if (m & (MSR_RI | MSR_TERI))
475 			bits |= TIOCM_RI;
476 		if (inb(iobase + com_ier))
477 			bits |= TIOCM_LE;
478 		*(int *)data = bits;
479 		break;
480 	}
481 	case TIOCGFLAGS: {
482 		int bits = 0;
483 
484 		if (sc->sc_swflags & COM_SW_SOFTCAR)
485 			bits |= TIOCFLAG_SOFTCAR;
486 		if (sc->sc_swflags & COM_SW_CLOCAL)
487 			bits |= TIOCFLAG_CLOCAL;
488 		if (sc->sc_swflags & COM_SW_CRTSCTS)
489 			bits |= TIOCFLAG_CRTSCTS;
490 		if (sc->sc_swflags & COM_SW_MDMBUF)
491 			bits |= TIOCFLAG_MDMBUF;
492 
493 		*(int *)data = bits;
494 		break;
495 	}
496 	case TIOCSFLAGS: {
497 		int userbits, driverbits = 0;
498 
499 		error = suser(p->p_ucred, &p->p_acflag);
500 		if (error != 0)
501 			return(EPERM);
502 
503 		userbits = *(int *)data;
504 		if ((userbits & TIOCFLAG_SOFTCAR) ||
505 		    (sc->sc_hwflags & COM_HW_CONSOLE))
506 			driverbits |= COM_SW_SOFTCAR;
507 		if (userbits & TIOCFLAG_CLOCAL)
508 			driverbits |= COM_SW_CLOCAL;
509 		if (userbits & TIOCFLAG_CRTSCTS)
510 			driverbits |= COM_SW_CRTSCTS;
511 		if (userbits & TIOCFLAG_MDMBUF)
512 			driverbits |= COM_SW_MDMBUF;
513 
514 		sc->sc_swflags = driverbits;
515 		break;
516 	}
517 	default:
518 		return ENOTTY;
519 	}
520 
521 	return 0;
522 }
523 
524 int
525 comparam(tp, t)
526 	struct tty *tp;
527 	struct termios *t;
528 {
529 	struct com_softc *sc = comcd.cd_devs[COMUNIT(tp->t_dev)];
530 	u_short iobase = sc->sc_iobase;
531 	int ospeed = comspeed(t->c_ospeed);
532 	u_char cfcr;
533 	int s;
534 
535 	/* check requested parameters */
536 	if (ospeed < 0 || (t->c_ispeed && t->c_ispeed != t->c_ospeed))
537 		return EINVAL;
538 
539 	switch (t->c_cflag & CSIZE) {
540 	case CS5:
541 		cfcr = CFCR_5BITS;
542 		break;
543 	case CS6:
544 		cfcr = CFCR_6BITS;
545 		break;
546 	case CS7:
547 		cfcr = CFCR_7BITS;
548 		break;
549 	case CS8:
550 		cfcr = CFCR_8BITS;
551 		break;
552 	}
553 	if (t->c_cflag & PARENB) {
554 		cfcr |= CFCR_PENAB;
555 		if ((t->c_cflag & PARODD) == 0)
556 			cfcr |= CFCR_PEVEN;
557 	}
558 	if (t->c_cflag & CSTOPB)
559 		cfcr |= CFCR_STOPB;
560 
561 	s = spltty();
562 
563 	if (ospeed == 0)
564 		outb(iobase + com_mcr, sc->sc_mcr &= ~MCR_DTR);
565 
566 	/*
567 	 * Set the FIFO threshold based on the receive speed, if we are
568 	 * changing it.
569 	 *
570 	 * XXX
571 	 * It would be better if we waited for the FIFO to empty, so we don't
572 	 * lose any in-transit characters.
573 	 */
574 	if (tp->t_ispeed != t->c_ispeed) {
575 		if (sc->sc_hwflags & COM_HW_FIFO)
576 			outb(iobase + com_fifo,
577 			    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST |
578 			    (t->c_ispeed <= 1200 ? FIFO_TRIGGER_1 : FIFO_TRIGGER_8));
579 	}
580 
581 	outb(iobase + com_cfcr, cfcr | CFCR_DLAB);
582 	outb(iobase + com_dlbl, ospeed);
583 	outb(iobase + com_dlbh, ospeed>>8);
584 	outb(iobase + com_cfcr, cfcr);
585 
586 	if (ospeed != 0)
587 		outb(iobase + com_mcr, sc->sc_mcr |= MCR_DTR);
588 
589 	/* When not using CRTSCTS, RTS follows DTR. */
590 	if ((t->c_cflag & CRTSCTS) == 0) {
591 		if (sc->sc_mcr & MCR_DTR) {
592 			if ((sc->sc_mcr & MCR_RTS) == 0)
593 				outb(iobase + com_mcr, sc->sc_mcr |= MCR_RTS);
594 		} else {
595 			if (sc->sc_mcr & MCR_RTS)
596 				outb(iobase + com_mcr, sc->sc_mcr &= ~MCR_RTS);
597 		}
598 	}
599 
600 	/*
601 	 * If CTS is off and CRTSCTS is changed, we must toggle TS_TTSTOP.
602 	 * XXX should be done at tty layer.
603 	 */
604 	if ((sc->sc_msr & MSR_CTS) == 0 &&
605 	    (tp->t_cflag & CRTSCTS) != (t->c_cflag & CRTSCTS)) {
606 		if ((t->c_cflag & CRTSCTS) == 0) {
607 			tp->t_state &= ~TS_TTSTOP;
608 			(*linesw[tp->t_line].l_start)(tp);
609 		} else
610 			tp->t_state |= TS_TTSTOP;
611 	}
612 
613 	/*
614 	 * If DCD is off and MDMBUF is changed, we must toggle TS_TTSTOP.
615 	 * XXX should be done at tty layer.
616 	 */
617 	if ((sc->sc_swflags & COM_SW_SOFTCAR) == 0 &&
618 	    (sc->sc_msr & MSR_DCD) == 0 &&
619 	    (tp->t_cflag & MDMBUF) != (t->c_cflag & MDMBUF)) {
620 		if ((t->c_cflag & MDMBUF) == 0) {
621 			tp->t_state &= ~TS_TTSTOP;
622 			(*linesw[tp->t_line].l_start)(tp);
623 		} else
624 			tp->t_state |= TS_TTSTOP;
625 	}
626 
627 	/* and copy to tty */
628 	tp->t_ispeed = t->c_ispeed;
629 	tp->t_ospeed = t->c_ospeed;
630 	tp->t_cflag = t->c_cflag;
631 
632 	splx(s);
633 	return 0;
634 }
635 
636 void
637 comstart(tp)
638 	struct tty *tp;
639 {
640 	struct com_softc *sc = comcd.cd_devs[COMUNIT(tp->t_dev)];
641 	u_short iobase = sc->sc_iobase;
642 	int s;
643 
644 	s = spltty();
645 	if (tp->t_state & (TS_TTSTOP | TS_BUSY))
646 		goto out;
647 #if 0 /* XXXX I think this is handled adequately by commint() and comparam(). */
648 	if (tp->t_cflag & CRTSCTS && (sc->sc_mcr & MSR_CTS) == 0)
649 		goto out;
650 #endif
651 	if (tp->t_outq.c_cc <= tp->t_lowat) {
652 		if (tp->t_state & TS_ASLEEP) {
653 			tp->t_state &= ~TS_ASLEEP;
654 			wakeup((caddr_t)&tp->t_outq);
655 		}
656 		selwakeup(&tp->t_wsel);
657 	}
658 	if (tp->t_outq.c_cc == 0)
659 		goto out;
660 	tp->t_state |= TS_BUSY;
661 	if ((inb(iobase + com_lsr) & LSR_TXRDY) == 0)
662 		goto out;
663 	if (sc->sc_hwflags & COM_HW_FIFO) {
664 		u_char buffer[16], *cp = buffer;
665 		int n = q_to_b(&tp->t_outq, cp, sizeof buffer);
666 		do {
667 			outb(iobase + com_data, *cp++);
668 		} while (--n);
669 	} else
670 		outb(iobase + com_data, getc(&tp->t_outq));
671 out:
672 	splx(s);
673 }
674 
675 /*
676  * Stop output on a line.
677  */
678 void
679 comstop(tp, flag)
680 	struct tty *tp;
681 {
682 	int s;
683 
684 	s = spltty();
685 	if (tp->t_state & TS_BUSY)
686 		if ((tp->t_state & TS_TTSTOP) == 0)
687 			tp->t_state |= TS_FLUSH;
688 	splx(s);
689 }
690 
691 static inline void
692 comeint(sc, stat)
693 	struct com_softc *sc;
694 	int stat;
695 {
696 	u_short iobase = sc->sc_iobase;
697 	int unit = sc->sc_dev.dv_unit;
698 	struct tty *tp = com_tty[unit];
699 	int c;
700 
701 	c = inb(iobase + com_data);
702 	if ((tp->t_state & TS_ISOPEN) == 0) {
703 #ifdef KGDB
704 		/* we don't care about parity errors */
705 		if (((stat & (LSR_BI | LSR_FE | LSR_PE)) == LSR_PE) &&
706 		    kgdb_dev == makedev(commajor, unit) && c == FRAME_END)
707 			kgdb_connect(0); /* trap into kgdb */
708 #endif
709 		return;
710 	}
711 	if (stat & (LSR_BI | LSR_FE))
712 		c |= TTY_FE;
713 	else if (stat & LSR_PE)
714 		c |= TTY_PE;
715 	if (stat & LSR_OE) {
716 		if (sc->sc_overflows++ == 0)
717 			timeout(comdiag, sc, 60 * hz);
718 	}
719 	/* XXXX put in FIFO and process later */
720 	(*linesw[tp->t_line].l_rint)(c, tp);
721 }
722 
723 static inline void
724 commint(sc)
725 	struct com_softc *sc;
726 {
727 	u_short iobase = sc->sc_iobase;
728 	struct tty *tp = com_tty[sc->sc_dev.dv_unit];
729 	u_char msr, delta;
730 
731 	msr = inb(iobase + com_msr);
732 	delta = msr ^ sc->sc_msr;
733 	sc->sc_msr = msr;
734 
735 	if (delta & MSR_DCD && (sc->sc_swflags & COM_SW_SOFTCAR) == 0) {
736 		if (msr & MSR_DCD)
737 			(void)(*linesw[tp->t_line].l_modem)(tp, 1);
738 		else if ((*linesw[tp->t_line].l_modem)(tp, 0) == 0)
739 			outb(iobase + com_mcr,
740 			    sc->sc_mcr &= ~(MCR_DTR | MCR_RTS));
741 	}
742 	if (delta & MSR_CTS && tp->t_cflag & CRTSCTS) {
743 		/* the line is up and we want to do rts/cts flow control */
744 		if (msr & MSR_CTS) {
745 			tp->t_state &= ~TS_TTSTOP;
746 			(*linesw[tp->t_line].l_start)(tp);
747 		} else
748 			tp->t_state |= TS_TTSTOP;
749 	}
750 }
751 
752 void
753 comdiag(arg)
754 	void *arg;
755 {
756 	struct com_softc *sc = arg;
757 	int overflows;
758 	int s;
759 
760 	s = spltty();
761 	overflows = sc->sc_overflows;
762 	sc->sc_overflows = 0;
763 	splx(s);
764 
765 	if (overflows)
766 		log(LOG_WARNING, "%s: %d silo overflow%s\n",
767 		    sc->sc_dev.dv_xname, overflows, overflows == 1 ? "" : "s");
768 }
769 
770 int
771 comintr(sc)
772 	struct com_softc *sc;
773 {
774 	u_short iobase = sc->sc_iobase;
775 	struct tty *tp;
776 	u_char code;
777 
778 	code = inb(iobase + com_iir) & IIR_IMASK;
779 	if (code & IIR_NOPEND)
780 		return 0;
781 
782 	for (;;) {
783 		if (code & IIR_RXRDY) {
784 			tp = com_tty[sc->sc_dev.dv_unit];
785 			/* XXXX put in FIFO and process later */
786 			while (code = (inb(iobase + com_lsr) & LSR_RCV_MASK)) {
787 				if (code == LSR_RXRDY) {
788 					code = inb(iobase + com_data);
789 					if (tp->t_state & TS_ISOPEN)
790 						(*linesw[tp->t_line].l_rint)(code, tp);
791 #ifdef KGDB
792 					else {
793 						if (kgdb_dev == makedev(commajor, unit) &&
794 						    code == FRAME_END)
795 							kgdb_connect(0);
796 					}
797 #endif
798 				} else
799 					comeint(sc, code);
800 			}
801 		} else if (code == IIR_TXRDY) {
802 			tp = com_tty[sc->sc_dev.dv_unit];
803 			tp->t_state &= ~TS_BUSY;
804 			if (tp->t_state & TS_FLUSH)
805 				tp->t_state &= ~TS_FLUSH;
806 			else
807 				if (tp->t_line)
808 					(*linesw[tp->t_line].l_start)(tp);
809 				else
810 					comstart(tp);
811 		} else if (code == IIR_MLSC) {
812 			commint(sc);
813 		} else {
814 			log(LOG_WARNING, "%s: weird interrupt: iir=0x%02x\n",
815 			    sc->sc_dev.dv_xname, code);
816 		}
817 		code = inb(iobase + com_iir) & IIR_IMASK;
818 		if (code & IIR_NOPEND)
819 			return 1;
820 	}
821 }
822 
823 /*
824  * Following are all routines needed for COM to act as console
825  */
826 #include <dev/cons.h>
827 
828 comcnprobe(cp)
829 	struct consdev *cp;
830 {
831 
832 	if (!comprobe1(CONADDR)) {
833 		cp->cn_pri = CN_DEAD;
834 		return;
835 	}
836 
837 	/* locate the major number */
838 	for (commajor = 0; commajor < nchrdev; commajor++)
839 		if (cdevsw[commajor].d_open == comopen)
840 			break;
841 
842 	/* initialize required fields */
843 	cp->cn_dev = makedev(commajor, CONUNIT);
844 #ifdef	COMCONSOLE
845 	cp->cn_pri = CN_REMOTE;		/* Force a serial port console */
846 #else
847 	cp->cn_pri = CN_NORMAL;
848 #endif
849 }
850 
851 comcninit(cp)
852 	struct consdev *cp;
853 {
854 
855 	cominit(CONUNIT, comdefaultrate);
856 	comconsole = CONUNIT;
857 	comconsinit = 0;
858 }
859 
860 cominit(unit, rate)
861 	int unit, rate;
862 {
863 	int s = splhigh();
864 	u_short iobase = CONADDR;
865 	u_char stat;
866 
867 	outb(iobase + com_cfcr, CFCR_DLAB);
868 	rate = comspeed(comdefaultrate);
869 	outb(iobase + com_dlbl, rate);
870 	outb(iobase + com_dlbh, rate >> 8);
871 	outb(iobase + com_cfcr, CFCR_8BITS);
872 	outb(iobase + com_ier, IER_ERXRDY | IER_ETXRDY);
873 	outb(iobase + com_fifo, FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_4);
874 	stat = inb(iobase + com_iir);
875 	splx(s);
876 }
877 
878 comcngetc(dev)
879 	dev_t dev;
880 {
881 	int s = splhigh();
882 	u_short iobase = CONADDR;
883 	u_char stat, c;
884 
885 	while (((stat = inb(iobase + com_lsr)) & LSR_RXRDY) == 0)
886 		;
887 	c = inb(iobase + com_data);
888 	stat = inb(iobase + com_iir);
889 	splx(s);
890 	return c;
891 }
892 
893 /*
894  * Console kernel output character routine.
895  */
896 comcnputc(dev, c)
897 	dev_t dev;
898 	int c;
899 {
900 	int s = splhigh();
901 	u_short iobase = CONADDR;
902 	u_char stat;
903 	register int timo;
904 
905 #ifdef KGDB
906 	if (dev != kgdb_dev)
907 #endif
908 	if (comconsinit == 0) {
909 		(void) cominit(COMUNIT(dev), comdefaultrate);
910 		comconsinit = 1;
911 	}
912 	/* wait for any pending transmission to finish */
913 	timo = 50000;
914 	while (((stat = inb(iobase + com_lsr)) & LSR_TXRDY) == 0 && --timo)
915 		;
916 	outb(iobase + com_data, c);
917 	/* wait for this transmission to complete */
918 	timo = 1500000;
919 	while (((stat = inb(iobase + com_lsr)) & LSR_TXRDY) == 0 && --timo)
920 		;
921 	/* clear any interrupts generated by this transmission */
922 	stat = inb(iobase + com_iir);
923 	splx(s);
924 }
925