xref: /netbsd-src/sys/dev/ic/com.c (revision 23c8222edbfb0f0932d88a8351d3a0cf817dfb9e)
1 /*	$NetBSD: com.c,v 1.231 2004/08/09 16:57:14 mycroft Exp $	*/
2 
3 /*-
4  * Copyright (c) 1998, 1999, 2004 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Charles M. Hannum.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *        This product includes software developed by the NetBSD
21  *        Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 /*
40  * Copyright (c) 1991 The Regents of the University of California.
41  * All rights reserved.
42  *
43  * Redistribution and use in source and binary forms, with or without
44  * modification, are permitted provided that the following conditions
45  * are met:
46  * 1. Redistributions of source code must retain the above copyright
47  *    notice, this list of conditions and the following disclaimer.
48  * 2. Redistributions in binary form must reproduce the above copyright
49  *    notice, this list of conditions and the following disclaimer in the
50  *    documentation and/or other materials provided with the distribution.
51  * 3. Neither the name of the University nor the names of its contributors
52  *    may be used to endorse or promote products derived from this software
53  *    without specific prior written permission.
54  *
55  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
56  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
57  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
58  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
59  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
60  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
61  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
62  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
63  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
64  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
65  * SUCH DAMAGE.
66  *
67  *	@(#)com.c	7.5 (Berkeley) 5/16/91
68  */
69 
70 /*
71  * COM driver, uses National Semiconductor NS16450/NS16550AF UART
72  * Supports automatic hardware flow control on StarTech ST16C650A UART
73  */
74 
75 #include <sys/cdefs.h>
76 __KERNEL_RCSID(0, "$NetBSD: com.c,v 1.231 2004/08/09 16:57:14 mycroft Exp $");
77 
78 #include "opt_com.h"
79 #include "opt_ddb.h"
80 #include "opt_kgdb.h"
81 #include "opt_lockdebug.h"
82 #include "opt_multiprocessor.h"
83 #include "opt_ntp.h"
84 
85 #include "rnd.h"
86 #if NRND > 0 && defined(RND_COM)
87 #include <sys/rnd.h>
88 #endif
89 
90 /* The COM16650 option was renamed to COM_16650. */
91 #ifdef COM16650
92 #error Obsolete COM16650 option; use COM_16650 instead.
93 #endif
94 
95 /*
96  * Override cnmagic(9) macro before including <sys/systm.h>.
97  * We need to know if cn_check_magic triggered debugger, so set a flag.
98  * Callers of cn_check_magic must declare int cn_trapped = 0;
99  * XXX: this is *ugly*!
100  */
101 #define cn_trap()				\
102 	do {					\
103 		console_debugger();		\
104 		cn_trapped = 1;			\
105 	} while (/* CONSTCOND */ 0)
106 
107 #include <sys/param.h>
108 #include <sys/systm.h>
109 #include <sys/ioctl.h>
110 #include <sys/select.h>
111 #include <sys/tty.h>
112 #include <sys/proc.h>
113 #include <sys/user.h>
114 #include <sys/conf.h>
115 #include <sys/file.h>
116 #include <sys/uio.h>
117 #include <sys/kernel.h>
118 #include <sys/syslog.h>
119 #include <sys/device.h>
120 #include <sys/malloc.h>
121 #include <sys/timepps.h>
122 #include <sys/vnode.h>
123 
124 #include <machine/intr.h>
125 #include <machine/bus.h>
126 
127 #include <dev/ic/comreg.h>
128 #include <dev/ic/comvar.h>
129 #include <dev/ic/ns16550reg.h>
130 #include <dev/ic/st16650reg.h>
131 #ifdef COM_HAYESP
132 #include <dev/ic/hayespreg.h>
133 #endif
134 #define	com_lcr	com_cfcr
135 #include <dev/cons.h>
136 
137 #ifdef COM_HAYESP
138 int comprobeHAYESP(bus_space_handle_t hayespioh, struct com_softc *sc);
139 #endif
140 
141 static void com_enable_debugport(struct com_softc *);
142 
143 void	com_config(struct com_softc *);
144 void	com_shutdown(struct com_softc *);
145 int	comspeed(long, long, int);
146 static	u_char	cflag2lcr(tcflag_t);
147 int	comparam(struct tty *, struct termios *);
148 void	comstart(struct tty *);
149 int	comhwiflow(struct tty *, int);
150 
151 void	com_loadchannelregs(struct com_softc *);
152 void	com_hwiflow(struct com_softc *);
153 void	com_break(struct com_softc *, int);
154 void	com_modem(struct com_softc *, int);
155 void	tiocm_to_com(struct com_softc *, u_long, int);
156 int	com_to_tiocm(struct com_softc *);
157 void	com_iflush(struct com_softc *);
158 
159 int	com_common_getc(dev_t, bus_space_tag_t, bus_space_handle_t);
160 void	com_common_putc(dev_t, bus_space_tag_t, bus_space_handle_t, int);
161 
162 int	cominit(bus_space_tag_t, bus_addr_t, int, int, int, tcflag_t,
163 	    bus_space_handle_t *);
164 
165 int	comcngetc(dev_t);
166 void	comcnputc(dev_t, int);
167 void	comcnpollc(dev_t, int);
168 
169 #define	integrate	static inline
170 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
171 void 	comsoft(void *);
172 #else
173 #ifndef __NO_SOFT_SERIAL_INTERRUPT
174 void 	comsoft(void);
175 #else
176 void 	comsoft(void *);
177 static struct callout comsoft_callout = CALLOUT_INITIALIZER;
178 #endif
179 #endif
180 integrate void com_rxsoft(struct com_softc *, struct tty *);
181 integrate void com_txsoft(struct com_softc *, struct tty *);
182 integrate void com_stsoft(struct com_softc *, struct tty *);
183 integrate void com_schedrx(struct com_softc *);
184 void	comdiag(void *);
185 
186 extern struct cfdriver com_cd;
187 
188 dev_type_open(comopen);
189 dev_type_close(comclose);
190 dev_type_read(comread);
191 dev_type_write(comwrite);
192 dev_type_ioctl(comioctl);
193 dev_type_stop(comstop);
194 dev_type_tty(comtty);
195 dev_type_poll(compoll);
196 
197 const struct cdevsw com_cdevsw = {
198 	comopen, comclose, comread, comwrite, comioctl,
199 	comstop, comtty, compoll, nommap, ttykqfilter, D_TTY
200 };
201 
202 /*
203  * Make this an option variable one can patch.
204  * But be warned:  this must be a power of 2!
205  */
206 u_int com_rbuf_size = COM_RING_SIZE;
207 
208 /* Stop input when 3/4 of the ring is full; restart when only 1/4 is full. */
209 u_int com_rbuf_hiwat = (COM_RING_SIZE * 1) / 4;
210 u_int com_rbuf_lowat = (COM_RING_SIZE * 3) / 4;
211 
212 static bus_addr_t	comconsaddr;
213 static bus_space_tag_t comconstag;
214 static bus_space_handle_t comconsioh;
215 static int	comconsattached;
216 static int comconsrate;
217 static tcflag_t comconscflag;
218 static struct cnm_state com_cnm_state;
219 
220 static int ppscap =
221 	PPS_TSFMT_TSPEC |
222 	PPS_CAPTUREASSERT |
223 	PPS_CAPTURECLEAR |
224 	PPS_OFFSETASSERT | PPS_OFFSETCLEAR;
225 
226 #ifndef __HAVE_GENERIC_SOFT_INTERRUPTS
227 #ifdef __NO_SOFT_SERIAL_INTERRUPT
228 volatile int	com_softintr_scheduled;
229 #endif
230 #endif
231 
232 #ifdef KGDB
233 #include <sys/kgdb.h>
234 
235 static bus_addr_t com_kgdb_addr;
236 static bus_space_tag_t com_kgdb_iot;
237 static bus_space_handle_t com_kgdb_ioh;
238 static int com_kgdb_attached;
239 
240 int	com_kgdb_getc(void *);
241 void	com_kgdb_putc(void *, int);
242 #endif /* KGDB */
243 
244 #define	COMUNIT_MASK	0x7ffff
245 #define	COMDIALOUT_MASK	0x80000
246 
247 #define	COMUNIT(x)	(minor(x) & COMUNIT_MASK)
248 #define	COMDIALOUT(x)	(minor(x) & COMDIALOUT_MASK)
249 
250 #define	COM_ISALIVE(sc)	((sc)->enabled != 0 && \
251 			 ISSET((sc)->sc_dev.dv_flags, DVF_ACTIVE))
252 
253 #define	BR	BUS_SPACE_BARRIER_READ
254 #define	BW	BUS_SPACE_BARRIER_WRITE
255 #define COM_BARRIER(t, h, f) bus_space_barrier((t), (h), 0, COM_NPORTS, (f))
256 
257 #if (defined(MULTIPROCESSOR) || defined(LOCKDEBUG)) && defined(COM_MPLOCK)
258 
259 #define COM_LOCK(sc) simple_lock(&(sc)->sc_lock)
260 #define COM_UNLOCK(sc) simple_unlock(&(sc)->sc_lock)
261 
262 #else
263 
264 #define COM_LOCK(sc)
265 #define COM_UNLOCK(sc)
266 
267 #endif
268 
269 /*ARGSUSED*/
270 int
271 comspeed(long speed, long frequency, int type)
272 {
273 #define	divrnd(n, q)	(((n)*2/(q)+1)/2)	/* divide and round off */
274 
275 	int x, err;
276 
277 #if 0
278 	if (speed == 0)
279 		return (0);
280 #endif
281 	if (speed <= 0)
282 		return (-1);
283 	x = divrnd(frequency / 16, speed);
284 	if (x <= 0)
285 		return (-1);
286 	err = divrnd(((quad_t)frequency) * 1000 / 16, speed * x) - 1000;
287 	if (err < 0)
288 		err = -err;
289 	if (err > COM_TOLERANCE)
290 		return (-1);
291 	return (x);
292 
293 #undef	divrnd
294 }
295 
296 #ifdef COM_DEBUG
297 int	com_debug = 0;
298 
299 void comstatus(struct com_softc *, char *);
300 void
301 comstatus(struct com_softc *sc, char *str)
302 {
303 	struct tty *tp = sc->sc_tty;
304 
305 	printf("%s: %s %cclocal  %cdcd %cts_carr_on %cdtr %ctx_stopped\n",
306 	    sc->sc_dev.dv_xname, str,
307 	    ISSET(tp->t_cflag, CLOCAL) ? '+' : '-',
308 	    ISSET(sc->sc_msr, MSR_DCD) ? '+' : '-',
309 	    ISSET(tp->t_state, TS_CARR_ON) ? '+' : '-',
310 	    ISSET(sc->sc_mcr, MCR_DTR) ? '+' : '-',
311 	    sc->sc_tx_stopped ? '+' : '-');
312 
313 	printf("%s: %s %ccrtscts %ccts %cts_ttstop  %crts rx_flags=0x%x\n",
314 	    sc->sc_dev.dv_xname, str,
315 	    ISSET(tp->t_cflag, CRTSCTS) ? '+' : '-',
316 	    ISSET(sc->sc_msr, MSR_CTS) ? '+' : '-',
317 	    ISSET(tp->t_state, TS_TTSTOP) ? '+' : '-',
318 	    ISSET(sc->sc_mcr, MCR_RTS) ? '+' : '-',
319 	    sc->sc_rx_flags);
320 }
321 #endif
322 
323 int
324 comprobe1(bus_space_tag_t iot, bus_space_handle_t ioh)
325 {
326 
327 	/* force access to id reg */
328 	bus_space_write_1(iot, ioh, com_lcr, LCR_8BITS);
329 	bus_space_write_1(iot, ioh, com_iir, 0);
330 	if ((bus_space_read_1(iot, ioh, com_lcr) != LCR_8BITS) ||
331 	    (bus_space_read_1(iot, ioh, com_iir) & 0x38))
332 		return (0);
333 
334 	return (1);
335 }
336 
337 #ifdef COM_HAYESP
338 int
339 comprobeHAYESP(bus_space_handle_t hayespioh, struct com_softc *sc)
340 {
341 	char	val, dips;
342 	int	combaselist[] = { 0x3f8, 0x2f8, 0x3e8, 0x2e8 };
343 	bus_space_tag_t iot = sc->sc_iot;
344 
345 	/*
346 	 * Hayes ESP cards have two iobases.  One is for compatibility with
347 	 * 16550 serial chips, and at the same ISA PC base addresses.  The
348 	 * other is for ESP-specific enhanced features, and lies at a
349 	 * different addressing range entirely (0x140, 0x180, 0x280, or 0x300).
350 	 */
351 
352 	/* Test for ESP signature */
353 	if ((bus_space_read_1(iot, hayespioh, 0) & 0xf3) == 0)
354 		return (0);
355 
356 	/*
357 	 * ESP is present at ESP enhanced base address; unknown com port
358 	 */
359 
360 	/* Get the dip-switch configurations */
361 	bus_space_write_1(iot, hayespioh, HAYESP_CMD1, HAYESP_GETDIPS);
362 	dips = bus_space_read_1(iot, hayespioh, HAYESP_STATUS1);
363 
364 	/* Determine which com port this ESP card services: bits 0,1 of  */
365 	/*  dips is the port # (0-3); combaselist[val] is the com_iobase */
366 	if (sc->sc_iobase != combaselist[dips & 0x03])
367 		return (0);
368 
369 	printf(": ESP");
370 
371  	/* Check ESP Self Test bits. */
372 	/* Check for ESP version 2.0: bits 4,5,6 == 010 */
373 	bus_space_write_1(iot, hayespioh, HAYESP_CMD1, HAYESP_GETTEST);
374 	val = bus_space_read_1(iot, hayespioh, HAYESP_STATUS1); /* Clear reg1 */
375 	val = bus_space_read_1(iot, hayespioh, HAYESP_STATUS2);
376 	if ((val & 0x70) < 0x20) {
377 		printf("-old (%o)", val & 0x70);
378 		/* we do not support the necessary features */
379 		return (0);
380 	}
381 
382 	/* Check for ability to emulate 16550: bit 8 == 1 */
383 	if ((dips & 0x80) == 0) {
384 		printf(" slave");
385 		/* XXX Does slave really mean no 16550 support?? */
386 		return (0);
387 	}
388 
389 	/*
390 	 * If we made it this far, we are a full-featured ESP v2.0 (or
391 	 * better), at the correct com port address.
392 	 */
393 
394 	sc->sc_type = COM_TYPE_HAYESP;
395 	printf(", 1024 byte fifo\n");
396 	return (1);
397 }
398 #endif
399 
400 static void
401 com_enable_debugport(struct com_softc *sc)
402 {
403 	int s;
404 
405 	/* Turn on line break interrupt, set carrier. */
406 	s = splserial();
407 	COM_LOCK(sc);
408 	sc->sc_ier = IER_ERXRDY;
409 #ifdef COM_PXA2X0
410 	if (sc->sc_type == COM_TYPE_PXA2x0)
411 		sc->sc_ier |= IER_EUART | IER_ERXTOUT;
412 #endif
413 	bus_space_write_1(sc->sc_iot, sc->sc_ioh, com_ier, sc->sc_ier);
414 	SET(sc->sc_mcr, MCR_DTR | MCR_RTS);
415 	bus_space_write_1(sc->sc_iot, sc->sc_ioh, com_mcr, sc->sc_mcr);
416 	COM_UNLOCK(sc);
417 	splx(s);
418 }
419 
420 void
421 com_attach_subr(struct com_softc *sc)
422 {
423 	bus_addr_t iobase = sc->sc_iobase;
424 	bus_space_tag_t iot = sc->sc_iot;
425 	bus_space_handle_t ioh = sc->sc_ioh;
426 	struct tty *tp;
427 #ifdef COM_16650
428 	u_int8_t lcr;
429 #endif
430 #ifdef COM_HAYESP
431 	int	hayesp_ports[] = { 0x140, 0x180, 0x280, 0x300, 0 };
432 	int	*hayespp;
433 #endif
434 	const char *fifo_msg = NULL;
435 
436 	callout_init(&sc->sc_diag_callout);
437 #if (defined(MULTIPROCESSOR) || defined(LOCKDEBUG)) && defined(COM_MPLOCK)
438 	simple_lock_init(&sc->sc_lock);
439 #endif
440 
441 	/* Disable interrupts before configuring the device. */
442 #ifdef COM_PXA2X0
443 	if (sc->sc_type == COM_TYPE_PXA2x0)
444 		sc->sc_ier = IER_EUART;
445 	else
446 #endif
447 		sc->sc_ier = 0;
448 	bus_space_write_1(iot, ioh, com_ier, sc->sc_ier);
449 
450 	if (iot == comconstag && iobase == comconsaddr) {
451 		comconsattached = 1;
452 
453 		/* Make sure the console is always "hardwired". */
454 		delay(10000);			/* wait for output to finish */
455 		SET(sc->sc_hwflags, COM_HW_CONSOLE);
456 		SET(sc->sc_swflags, TIOCFLAG_SOFTCAR);
457 	}
458 
459 #ifdef COM_HAYESP
460 	sc->sc_prescaler = 0;			/* set prescaler to x1. */
461 
462 	/* Look for a Hayes ESP board. */
463 	for (hayespp = hayesp_ports; *hayespp != 0; hayespp++) {
464 		bus_space_handle_t hayespioh;
465 
466 #define	HAYESP_NPORTS	8			/* XXX XXX XXX ??? ??? ??? */
467 		if (bus_space_map(iot, *hayespp, HAYESP_NPORTS, 0, &hayespioh))
468 			continue;
469 		if (comprobeHAYESP(hayespioh, sc)) {
470 			sc->sc_hayespioh = hayespioh;
471 			sc->sc_fifolen = 1024;
472 
473 			break;
474 		}
475 		bus_space_unmap(iot, hayespioh, HAYESP_NPORTS);
476 	}
477 	/* No ESP; look for other things. */
478 	if (sc->sc_type != COM_TYPE_HAYESP) {
479 #endif
480 	sc->sc_fifolen = 1;
481 	/* look for a NS 16550AF UART with FIFOs */
482 	bus_space_write_1(iot, ioh, com_fifo,
483 	    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_14);
484 	delay(100);
485 	if (ISSET(bus_space_read_1(iot, ioh, com_iir), IIR_FIFO_MASK)
486 	    == IIR_FIFO_MASK)
487 		if (ISSET(bus_space_read_1(iot, ioh, com_fifo), FIFO_TRIGGER_14)
488 		    == FIFO_TRIGGER_14) {
489 			SET(sc->sc_hwflags, COM_HW_FIFO);
490 
491 #ifdef COM_16650
492 			/*
493 			 * IIR changes into the EFR if LCR is set to LCR_EERS
494 			 * on 16650s. We also know IIR != 0 at this point.
495 			 * Write 0 into the EFR, and read it. If the result
496 			 * is 0, we have a 16650.
497 			 *
498 			 * Older 16650s were broken; the test to detect them
499 			 * is taken from the Linux driver. Apparently
500 			 * setting DLAB enable gives access to the EFR on
501 			 * these chips.
502 			 */
503 			lcr = bus_space_read_1(iot, ioh, com_lcr);
504 			bus_space_write_1(iot, ioh, com_lcr, LCR_EERS);
505 			bus_space_write_1(iot, ioh, com_efr, 0);
506 			if (bus_space_read_1(iot, ioh, com_efr) == 0) {
507 				bus_space_write_1(iot, ioh, com_lcr,
508 				    lcr | LCR_DLAB);
509 				if (bus_space_read_1(iot, ioh, com_efr) == 0) {
510 					CLR(sc->sc_hwflags, COM_HW_FIFO);
511 					sc->sc_fifolen = 0;
512 				} else {
513 					SET(sc->sc_hwflags, COM_HW_FLOW);
514 					sc->sc_fifolen = 32;
515 				}
516 			} else
517 #endif
518 				sc->sc_fifolen = 16;
519 
520 #ifdef COM_16650
521 			bus_space_write_1(iot, ioh, com_lcr, lcr);
522 			if (sc->sc_fifolen == 0)
523 				fifo_msg = "st16650, broken fifo";
524 			else if (sc->sc_fifolen == 32)
525 				fifo_msg = "st16650a, working fifo";
526 			else
527 #endif
528 				fifo_msg = "ns16550a, working fifo";
529 		} else
530 			fifo_msg = "ns16550, broken fifo";
531 	else
532 		fifo_msg = "ns8250 or ns16450, no fifo";
533 	bus_space_write_1(iot, ioh, com_fifo, 0);
534 	/*
535 	 * Some chips will clear down both Tx and Rx FIFOs when zero is
536 	 * written to com_fifo. If this chip is the console, writing zero
537 	 * results in some of the chip/FIFO description being lost, so delay
538 	 * printing it until now.
539 	 */
540 	delay(10);
541 	aprint_normal(": %s\n", fifo_msg);
542 	if (ISSET(sc->sc_hwflags, COM_HW_TXFIFO_DISABLE)) {
543 		sc->sc_fifolen = 1;
544 		aprint_normal("%s: txfifo disabled\n", sc->sc_dev.dv_xname);
545 	}
546 #ifdef COM_HAYESP
547 	}
548 #endif
549 
550 	tp = ttymalloc();
551 	tp->t_oproc = comstart;
552 	tp->t_param = comparam;
553 	tp->t_hwiflow = comhwiflow;
554 
555 	sc->sc_tty = tp;
556 	sc->sc_rbuf = malloc(com_rbuf_size << 1, M_DEVBUF, M_NOWAIT);
557 	sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
558 	sc->sc_rbavail = com_rbuf_size;
559 	if (sc->sc_rbuf == NULL) {
560 		aprint_error("%s: unable to allocate ring buffer\n",
561 		    sc->sc_dev.dv_xname);
562 		return;
563 	}
564 	sc->sc_ebuf = sc->sc_rbuf + (com_rbuf_size << 1);
565 
566 	tty_attach(tp);
567 
568 	if (!ISSET(sc->sc_hwflags, COM_HW_NOIEN))
569 		SET(sc->sc_mcr, MCR_IENABLE);
570 
571 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
572 		int maj;
573 
574 		/* locate the major number */
575 		maj = cdevsw_lookup_major(&com_cdevsw);
576 
577 		tp->t_dev = cn_tab->cn_dev = makedev(maj, sc->sc_dev.dv_unit);
578 
579 		aprint_normal("%s: console\n", sc->sc_dev.dv_xname);
580 	}
581 
582 #ifdef KGDB
583 	/*
584 	 * Allow kgdb to "take over" this port.  If this is
585 	 * not the console and is the kgdb device, it has
586 	 * exclusive use.  If it's the console _and_ the
587 	 * kgdb device, it doesn't.
588 	 */
589 	if (iot == com_kgdb_iot && iobase == com_kgdb_addr) {
590 		if (!ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
591 			com_kgdb_attached = 1;
592 
593 			SET(sc->sc_hwflags, COM_HW_KGDB);
594 		}
595 		aprint_normal("%s: kgdb\n", sc->sc_dev.dv_xname);
596 	}
597 #endif
598 
599 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
600 	sc->sc_si = softintr_establish(IPL_SOFTSERIAL, comsoft, sc);
601 #endif
602 
603 #if NRND > 0 && defined(RND_COM)
604 	rnd_attach_source(&sc->rnd_source, sc->sc_dev.dv_xname,
605 			  RND_TYPE_TTY, 0);
606 #endif
607 
608 	/* if there are no enable/disable functions, assume the device
609 	   is always enabled */
610 	if (!sc->enable)
611 		sc->enabled = 1;
612 
613 	com_config(sc);
614 
615 	SET(sc->sc_hwflags, COM_HW_DEV_OK);
616 }
617 
618 void
619 com_config(struct com_softc *sc)
620 {
621 	bus_space_tag_t iot = sc->sc_iot;
622 	bus_space_handle_t ioh = sc->sc_ioh;
623 
624 	/* Disable interrupts before configuring the device. */
625 #ifdef COM_PXA2X0
626 	if (sc->sc_type == COM_TYPE_PXA2x0)
627 		sc->sc_ier = IER_EUART;
628 	else
629 #endif
630 		sc->sc_ier = 0;
631 	bus_space_write_1(iot, ioh, com_ier, sc->sc_ier);
632 	(void) bus_space_read_1(iot, ioh, com_iir);
633 
634 #ifdef COM_HAYESP
635 	/* Look for a Hayes ESP board. */
636 	if (sc->sc_type == COM_TYPE_HAYESP) {
637 		sc->sc_fifolen = 1024;
638 
639 		/* Set 16550 compatibility mode */
640 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD1,
641 				  HAYESP_SETMODE);
642 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
643 				  HAYESP_MODE_FIFO|HAYESP_MODE_RTS|
644 				  HAYESP_MODE_SCALE);
645 
646 		/* Set RTS/CTS flow control */
647 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD1,
648 				  HAYESP_SETFLOWTYPE);
649 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
650 				  HAYESP_FLOW_RTS);
651 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
652 				  HAYESP_FLOW_CTS);
653 
654 		/* Set flow control levels */
655 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD1,
656 				  HAYESP_SETRXFLOW);
657 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
658 				  HAYESP_HIBYTE(HAYESP_RXHIWMARK));
659 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
660 				  HAYESP_LOBYTE(HAYESP_RXHIWMARK));
661 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
662 				  HAYESP_HIBYTE(HAYESP_RXLOWMARK));
663 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
664 				  HAYESP_LOBYTE(HAYESP_RXLOWMARK));
665 	}
666 #endif
667 
668 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE|COM_HW_KGDB))
669 		com_enable_debugport(sc);
670 }
671 
672 int
673 com_detach(struct device *self, int flags)
674 {
675 	struct com_softc *sc = (struct com_softc *)self;
676 	int maj, mn;
677 
678 	/* locate the major number */
679 	maj = cdevsw_lookup_major(&com_cdevsw);
680 
681 	/* Nuke the vnodes for any open instances. */
682 	mn = self->dv_unit;
683 	vdevgone(maj, mn, mn, VCHR);
684 
685 	mn |= COMDIALOUT_MASK;
686 	vdevgone(maj, mn, mn, VCHR);
687 
688 	if (sc->sc_rbuf == NULL) {
689 		/*
690 		 * Ring buffer allocation failed in the com_attach_subr,
691 		 * only the tty is allocated, and nothing else.
692 		 */
693 		ttyfree(sc->sc_tty);
694 		return 0;
695 	}
696 
697 	/* Free the receive buffer. */
698 	free(sc->sc_rbuf, M_DEVBUF);
699 
700 	/* Detach and free the tty. */
701 	tty_detach(sc->sc_tty);
702 	ttyfree(sc->sc_tty);
703 
704 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
705 	/* Unhook the soft interrupt handler. */
706 	softintr_disestablish(sc->sc_si);
707 #endif
708 
709 #if NRND > 0 && defined(RND_COM)
710 	/* Unhook the entropy source. */
711 	rnd_detach_source(&sc->rnd_source);
712 #endif
713 
714 	return (0);
715 }
716 
717 int
718 com_activate(struct device *self, enum devact act)
719 {
720 	struct com_softc *sc = (struct com_softc *)self;
721 	int s, rv = 0;
722 
723 	s = splserial();
724 	COM_LOCK(sc);
725 	switch (act) {
726 	case DVACT_ACTIVATE:
727 		rv = EOPNOTSUPP;
728 		break;
729 
730 	case DVACT_DEACTIVATE:
731 		if (sc->sc_hwflags & (COM_HW_CONSOLE|COM_HW_KGDB)) {
732 			rv = EBUSY;
733 			break;
734 		}
735 
736 		if (sc->disable != NULL && sc->enabled != 0) {
737 			(*sc->disable)(sc);
738 			sc->enabled = 0;
739 		}
740 		break;
741 	}
742 
743 	COM_UNLOCK(sc);
744 	splx(s);
745 	return (rv);
746 }
747 
748 void
749 com_shutdown(struct com_softc *sc)
750 {
751 	struct tty *tp = sc->sc_tty;
752 	int s;
753 
754 	s = splserial();
755 	COM_LOCK(sc);
756 
757 	/* If we were asserting flow control, then deassert it. */
758 	SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
759 	com_hwiflow(sc);
760 
761 	/* Clear any break condition set with TIOCSBRK. */
762 	com_break(sc, 0);
763 
764 	/* Turn off PPS capture on last close. */
765 	sc->sc_ppsmask = 0;
766 	sc->ppsparam.mode = 0;
767 
768 	/*
769 	 * Hang up if necessary.  Wait a bit, so the other side has time to
770 	 * notice even if we immediately open the port again.
771 	 * Avoid tsleeping above splhigh().
772 	 */
773 	if (ISSET(tp->t_cflag, HUPCL)) {
774 		com_modem(sc, 0);
775 		COM_UNLOCK(sc);
776 		splx(s);
777 		/* XXX tsleep will only timeout */
778 		(void) tsleep(sc, TTIPRI, ttclos, hz);
779 		s = splserial();
780 		COM_LOCK(sc);
781 	}
782 
783 	/* Turn off interrupts. */
784 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
785 		sc->sc_ier = IER_ERXRDY; /* interrupt on break */
786 #ifdef COM_PXA2X0
787 		if (sc->sc_type == COM_TYPE_PXA2x0)
788 			sc->sc_ier |= IER_ERXTOUT;
789 #endif
790 	} else
791 		sc->sc_ier = 0;
792 
793 #ifdef COM_PXA2X0
794 	if (sc->sc_type == COM_TYPE_PXA2x0)
795 		sc->sc_ier |= IER_EUART;
796 #endif
797 
798 	bus_space_write_1(sc->sc_iot, sc->sc_ioh, com_ier, sc->sc_ier);
799 
800 	if (sc->disable) {
801 #ifdef DIAGNOSTIC
802 		if (!sc->enabled)
803 			panic("com_shutdown: not enabled?");
804 #endif
805 		(*sc->disable)(sc);
806 		sc->enabled = 0;
807 	}
808 	COM_UNLOCK(sc);
809 	splx(s);
810 }
811 
812 int
813 comopen(dev_t dev, int flag, int mode, struct proc *p)
814 {
815 	struct com_softc *sc;
816 	struct tty *tp;
817 	int s, s2;
818 	int error;
819 
820 	sc = device_lookup(&com_cd, COMUNIT(dev));
821 	if (sc == NULL || !ISSET(sc->sc_hwflags, COM_HW_DEV_OK) ||
822 		sc->sc_rbuf == NULL)
823 		return (ENXIO);
824 
825 	if (ISSET(sc->sc_dev.dv_flags, DVF_ACTIVE) == 0)
826 		return (ENXIO);
827 
828 #ifdef KGDB
829 	/*
830 	 * If this is the kgdb port, no other use is permitted.
831 	 */
832 	if (ISSET(sc->sc_hwflags, COM_HW_KGDB))
833 		return (EBUSY);
834 #endif
835 
836 	tp = sc->sc_tty;
837 
838 	if (ISSET(tp->t_state, TS_ISOPEN) &&
839 	    ISSET(tp->t_state, TS_XCLUDE) &&
840 		p->p_ucred->cr_uid != 0)
841 		return (EBUSY);
842 
843 	s = spltty();
844 
845 	/*
846 	 * Do the following iff this is a first open.
847 	 */
848 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
849 		struct termios t;
850 
851 		tp->t_dev = dev;
852 
853 		s2 = splserial();
854 		COM_LOCK(sc);
855 
856 		if (sc->enable) {
857 			if ((*sc->enable)(sc)) {
858 				COM_UNLOCK(sc);
859 				splx(s2);
860 				splx(s);
861 				printf("%s: device enable failed\n",
862 				       sc->sc_dev.dv_xname);
863 				return (EIO);
864 			}
865 			sc->enabled = 1;
866 			com_config(sc);
867 		}
868 
869 		/* Turn on interrupts. */
870 		sc->sc_ier = IER_ERXRDY | IER_ERLS | IER_EMSC;
871 #ifdef COM_PXA2X0
872 		if (sc->sc_type == COM_TYPE_PXA2x0)
873 			sc->sc_ier |= IER_EUART | IER_ERXTOUT;
874 #endif
875 		bus_space_write_1(sc->sc_iot, sc->sc_ioh, com_ier, sc->sc_ier);
876 
877 		/* Fetch the current modem control status, needed later. */
878 		sc->sc_msr = bus_space_read_1(sc->sc_iot, sc->sc_ioh, com_msr);
879 
880 		/* Clear PPS capture state on first open. */
881 		sc->sc_ppsmask = 0;
882 		sc->ppsparam.mode = 0;
883 
884 		COM_UNLOCK(sc);
885 		splx(s2);
886 
887 		/*
888 		 * Initialize the termios status to the defaults.  Add in the
889 		 * sticky bits from TIOCSFLAGS.
890 		 */
891 		t.c_ispeed = 0;
892 		if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
893 			t.c_ospeed = comconsrate;
894 			t.c_cflag = comconscflag;
895 		} else {
896 			t.c_ospeed = TTYDEF_SPEED;
897 			t.c_cflag = TTYDEF_CFLAG;
898 		}
899 		if (ISSET(sc->sc_swflags, TIOCFLAG_CLOCAL))
900 			SET(t.c_cflag, CLOCAL);
901 		if (ISSET(sc->sc_swflags, TIOCFLAG_CRTSCTS))
902 			SET(t.c_cflag, CRTSCTS);
903 		if (ISSET(sc->sc_swflags, TIOCFLAG_MDMBUF))
904 			SET(t.c_cflag, MDMBUF);
905 		/* Make sure comparam() will do something. */
906 		tp->t_ospeed = 0;
907 		(void) comparam(tp, &t);
908 		tp->t_iflag = TTYDEF_IFLAG;
909 		tp->t_oflag = TTYDEF_OFLAG;
910 		tp->t_lflag = TTYDEF_LFLAG;
911 		ttychars(tp);
912 		ttsetwater(tp);
913 
914 		s2 = splserial();
915 		COM_LOCK(sc);
916 
917 		/*
918 		 * Turn on DTR.  We must always do this, even if carrier is not
919 		 * present, because otherwise we'd have to use TIOCSDTR
920 		 * immediately after setting CLOCAL, which applications do not
921 		 * expect.  We always assert DTR while the device is open
922 		 * unless explicitly requested to deassert it.
923 		 */
924 		com_modem(sc, 1);
925 
926 		/* Clear the input ring, and unblock. */
927 		sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
928 		sc->sc_rbavail = com_rbuf_size;
929 		com_iflush(sc);
930 		CLR(sc->sc_rx_flags, RX_ANY_BLOCK);
931 		com_hwiflow(sc);
932 
933 #ifdef COM_DEBUG
934 		if (com_debug)
935 			comstatus(sc, "comopen  ");
936 #endif
937 
938 		COM_UNLOCK(sc);
939 		splx(s2);
940 	}
941 
942 	splx(s);
943 
944 	error = ttyopen(tp, COMDIALOUT(dev), ISSET(flag, O_NONBLOCK));
945 	if (error)
946 		goto bad;
947 
948 	error = (*tp->t_linesw->l_open)(dev, tp);
949 	if (error)
950 		goto bad;
951 
952 	return (0);
953 
954 bad:
955 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
956 		/*
957 		 * We failed to open the device, and nobody else had it opened.
958 		 * Clean up the state as appropriate.
959 		 */
960 		com_shutdown(sc);
961 	}
962 
963 	return (error);
964 }
965 
966 int
967 comclose(dev_t dev, int flag, int mode, struct proc *p)
968 {
969 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(dev));
970 	struct tty *tp = sc->sc_tty;
971 
972 	/* XXX This is for cons.c. */
973 	if (!ISSET(tp->t_state, TS_ISOPEN))
974 		return (0);
975 
976 	(*tp->t_linesw->l_close)(tp, flag);
977 	ttyclose(tp);
978 
979 	if (COM_ISALIVE(sc) == 0)
980 		return (0);
981 
982 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
983 		/*
984 		 * Although we got a last close, the device may still be in
985 		 * use; e.g. if this was the dialout node, and there are still
986 		 * processes waiting for carrier on the non-dialout node.
987 		 */
988 		com_shutdown(sc);
989 	}
990 
991 	return (0);
992 }
993 
994 int
995 comread(dev_t dev, struct uio *uio, int flag)
996 {
997 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(dev));
998 	struct tty *tp = sc->sc_tty;
999 
1000 	if (COM_ISALIVE(sc) == 0)
1001 		return (EIO);
1002 
1003 	return ((*tp->t_linesw->l_read)(tp, uio, flag));
1004 }
1005 
1006 int
1007 comwrite(dev_t dev, struct uio *uio, int flag)
1008 {
1009 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(dev));
1010 	struct tty *tp = sc->sc_tty;
1011 
1012 	if (COM_ISALIVE(sc) == 0)
1013 		return (EIO);
1014 
1015 	return ((*tp->t_linesw->l_write)(tp, uio, flag));
1016 }
1017 
1018 int
1019 compoll(dev_t dev, int events, struct proc *p)
1020 {
1021 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(dev));
1022 	struct tty *tp = sc->sc_tty;
1023 
1024 	if (COM_ISALIVE(sc) == 0)
1025 		return (EIO);
1026 
1027 	return ((*tp->t_linesw->l_poll)(tp, events, p));
1028 }
1029 
1030 struct tty *
1031 comtty(dev_t dev)
1032 {
1033 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(dev));
1034 	struct tty *tp = sc->sc_tty;
1035 
1036 	return (tp);
1037 }
1038 
1039 int
1040 comioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct proc *p)
1041 {
1042 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(dev));
1043 	struct tty *tp = sc->sc_tty;
1044 	int error;
1045 	int s;
1046 
1047 	if (COM_ISALIVE(sc) == 0)
1048 		return (EIO);
1049 
1050 	error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, p);
1051 	if (error != EPASSTHROUGH)
1052 		return (error);
1053 
1054 	error = ttioctl(tp, cmd, data, flag, p);
1055 	if (error != EPASSTHROUGH)
1056 		return (error);
1057 
1058 	error = 0;
1059 
1060 	s = splserial();
1061 	COM_LOCK(sc);
1062 
1063 	switch (cmd) {
1064 	case TIOCSBRK:
1065 		com_break(sc, 1);
1066 		break;
1067 
1068 	case TIOCCBRK:
1069 		com_break(sc, 0);
1070 		break;
1071 
1072 	case TIOCSDTR:
1073 		com_modem(sc, 1);
1074 		break;
1075 
1076 	case TIOCCDTR:
1077 		com_modem(sc, 0);
1078 		break;
1079 
1080 	case TIOCGFLAGS:
1081 		*(int *)data = sc->sc_swflags;
1082 		break;
1083 
1084 	case TIOCSFLAGS:
1085 		error = suser(p->p_ucred, &p->p_acflag);
1086 		if (error)
1087 			break;
1088 		sc->sc_swflags = *(int *)data;
1089 		break;
1090 
1091 	case TIOCMSET:
1092 	case TIOCMBIS:
1093 	case TIOCMBIC:
1094 		tiocm_to_com(sc, cmd, *(int *)data);
1095 		break;
1096 
1097 	case TIOCMGET:
1098 		*(int *)data = com_to_tiocm(sc);
1099 		break;
1100 
1101 	case PPS_IOC_CREATE:
1102 		break;
1103 
1104 	case PPS_IOC_DESTROY:
1105 		break;
1106 
1107 	case PPS_IOC_GETPARAMS: {
1108 		pps_params_t *pp;
1109 		pp = (pps_params_t *)data;
1110 		*pp = sc->ppsparam;
1111 		break;
1112 	}
1113 
1114 	case PPS_IOC_SETPARAMS: {
1115 	  	pps_params_t *pp;
1116 		int mode;
1117 		pp = (pps_params_t *)data;
1118 		if (pp->mode & ~ppscap) {
1119 			error = EINVAL;
1120 			break;
1121 		}
1122 		sc->ppsparam = *pp;
1123 	 	/*
1124 		 * Compute msr masks from user-specified timestamp state.
1125 		 */
1126 		mode = sc->ppsparam.mode;
1127 		switch (mode & PPS_CAPTUREBOTH) {
1128 		case 0:
1129 			sc->sc_ppsmask = 0;
1130 			break;
1131 
1132 		case PPS_CAPTUREASSERT:
1133 			sc->sc_ppsmask = MSR_DCD;
1134 			sc->sc_ppsassert = MSR_DCD;
1135 			sc->sc_ppsclear = -1;
1136 			break;
1137 
1138 		case PPS_CAPTURECLEAR:
1139 			sc->sc_ppsmask = MSR_DCD;
1140 			sc->sc_ppsassert = -1;
1141 			sc->sc_ppsclear = 0;
1142 			break;
1143 
1144 		case PPS_CAPTUREBOTH:
1145 			sc->sc_ppsmask = MSR_DCD;
1146 			sc->sc_ppsassert = MSR_DCD;
1147 			sc->sc_ppsclear = 0;
1148 			break;
1149 
1150 		default:
1151 			error = EINVAL;
1152 			break;
1153 		}
1154 		break;
1155 	}
1156 
1157 	case PPS_IOC_GETCAP:
1158 		*(int*)data = ppscap;
1159 		break;
1160 
1161 	case PPS_IOC_FETCH: {
1162 		pps_info_t *pi;
1163 		pi = (pps_info_t *)data;
1164 		*pi = sc->ppsinfo;
1165 		break;
1166 	}
1167 
1168 #ifdef PPS_SYNC
1169 	case PPS_IOC_KCBIND: {
1170 		int edge = (*(int *)data) & PPS_CAPTUREBOTH;
1171 
1172 		if (edge == 0) {
1173 			/*
1174 			 * remove binding for this source; ignore
1175 			 * the request if this is not the current
1176 			 * hardpps source
1177 			 */
1178 			if (pps_kc_hardpps_source == sc) {
1179 				pps_kc_hardpps_source = NULL;
1180 				pps_kc_hardpps_mode = 0;
1181 			}
1182 		} else {
1183 			/*
1184 			 * bind hardpps to this source, replacing any
1185 			 * previously specified source or edges
1186 			 */
1187 			pps_kc_hardpps_source = sc;
1188 			pps_kc_hardpps_mode = edge;
1189 		}
1190 		break;
1191 	}
1192 #endif /* PPS_SYNC */
1193 
1194 	case TIOCDCDTIMESTAMP:	/* XXX old, overloaded  API used by xntpd v3 */
1195 		/*
1196 		 * Some GPS clocks models use the falling rather than
1197 		 * rising edge as the on-the-second signal.
1198 		 * The old API has no way to specify PPS polarity.
1199 		 */
1200 		sc->sc_ppsmask = MSR_DCD;
1201 #ifndef PPS_TRAILING_EDGE
1202 		sc->sc_ppsassert = MSR_DCD;
1203 		sc->sc_ppsclear = -1;
1204 		TIMESPEC_TO_TIMEVAL((struct timeval *)data,
1205 		    &sc->ppsinfo.assert_timestamp);
1206 #else
1207 		sc->sc_ppsassert = -1;
1208 		sc->sc_ppsclear = 0;
1209 		TIMESPEC_TO_TIMEVAL((struct timeval *)data,
1210 		    &sc->ppsinfo.clear_timestamp);
1211 #endif
1212 		break;
1213 
1214 	default:
1215 		error = EPASSTHROUGH;
1216 		break;
1217 	}
1218 
1219 	COM_UNLOCK(sc);
1220 	splx(s);
1221 
1222 #ifdef COM_DEBUG
1223 	if (com_debug)
1224 		comstatus(sc, "comioctl ");
1225 #endif
1226 
1227 	return (error);
1228 }
1229 
1230 integrate void
1231 com_schedrx(struct com_softc *sc)
1232 {
1233 
1234 	sc->sc_rx_ready = 1;
1235 
1236 	/* Wake up the poller. */
1237 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
1238 	softintr_schedule(sc->sc_si);
1239 #else
1240 #ifndef __NO_SOFT_SERIAL_INTERRUPT
1241 	setsoftserial();
1242 #else
1243 	if (!com_softintr_scheduled) {
1244 		com_softintr_scheduled = 1;
1245 		callout_reset(&comsoft_callout, 1, comsoft, NULL);
1246 	}
1247 #endif
1248 #endif
1249 }
1250 
1251 void
1252 com_break(struct com_softc *sc, int onoff)
1253 {
1254 
1255 	if (onoff)
1256 		SET(sc->sc_lcr, LCR_SBREAK);
1257 	else
1258 		CLR(sc->sc_lcr, LCR_SBREAK);
1259 
1260 	if (!sc->sc_heldchange) {
1261 		if (sc->sc_tx_busy) {
1262 			sc->sc_heldtbc = sc->sc_tbc;
1263 			sc->sc_tbc = 0;
1264 			sc->sc_heldchange = 1;
1265 		} else
1266 			com_loadchannelregs(sc);
1267 	}
1268 }
1269 
1270 void
1271 com_modem(struct com_softc *sc, int onoff)
1272 {
1273 
1274 	if (sc->sc_mcr_dtr == 0)
1275 		return;
1276 
1277 	if (onoff)
1278 		SET(sc->sc_mcr, sc->sc_mcr_dtr);
1279 	else
1280 		CLR(sc->sc_mcr, sc->sc_mcr_dtr);
1281 
1282 	if (!sc->sc_heldchange) {
1283 		if (sc->sc_tx_busy) {
1284 			sc->sc_heldtbc = sc->sc_tbc;
1285 			sc->sc_tbc = 0;
1286 			sc->sc_heldchange = 1;
1287 		} else
1288 			com_loadchannelregs(sc);
1289 	}
1290 }
1291 
1292 void
1293 tiocm_to_com(struct com_softc *sc, u_long how, int ttybits)
1294 {
1295 	u_char combits;
1296 
1297 	combits = 0;
1298 	if (ISSET(ttybits, TIOCM_DTR))
1299 		SET(combits, MCR_DTR);
1300 	if (ISSET(ttybits, TIOCM_RTS))
1301 		SET(combits, MCR_RTS);
1302 
1303 	switch (how) {
1304 	case TIOCMBIC:
1305 		CLR(sc->sc_mcr, combits);
1306 		break;
1307 
1308 	case TIOCMBIS:
1309 		SET(sc->sc_mcr, combits);
1310 		break;
1311 
1312 	case TIOCMSET:
1313 		CLR(sc->sc_mcr, MCR_DTR | MCR_RTS);
1314 		SET(sc->sc_mcr, combits);
1315 		break;
1316 	}
1317 
1318 	if (!sc->sc_heldchange) {
1319 		if (sc->sc_tx_busy) {
1320 			sc->sc_heldtbc = sc->sc_tbc;
1321 			sc->sc_tbc = 0;
1322 			sc->sc_heldchange = 1;
1323 		} else
1324 			com_loadchannelregs(sc);
1325 	}
1326 }
1327 
1328 int
1329 com_to_tiocm(struct com_softc *sc)
1330 {
1331 	u_char combits;
1332 	int ttybits = 0;
1333 
1334 	combits = sc->sc_mcr;
1335 	if (ISSET(combits, MCR_DTR))
1336 		SET(ttybits, TIOCM_DTR);
1337 	if (ISSET(combits, MCR_RTS))
1338 		SET(ttybits, TIOCM_RTS);
1339 
1340 	combits = sc->sc_msr;
1341 	if (ISSET(combits, MSR_DCD))
1342 		SET(ttybits, TIOCM_CD);
1343 	if (ISSET(combits, MSR_CTS))
1344 		SET(ttybits, TIOCM_CTS);
1345 	if (ISSET(combits, MSR_DSR))
1346 		SET(ttybits, TIOCM_DSR);
1347 	if (ISSET(combits, MSR_RI | MSR_TERI))
1348 		SET(ttybits, TIOCM_RI);
1349 
1350 	if (ISSET(sc->sc_ier, IER_ERXRDY | IER_ETXRDY | IER_ERLS | IER_EMSC))
1351 		SET(ttybits, TIOCM_LE);
1352 
1353 	return (ttybits);
1354 }
1355 
1356 static u_char
1357 cflag2lcr(tcflag_t cflag)
1358 {
1359 	u_char lcr = 0;
1360 
1361 	switch (ISSET(cflag, CSIZE)) {
1362 	case CS5:
1363 		SET(lcr, LCR_5BITS);
1364 		break;
1365 	case CS6:
1366 		SET(lcr, LCR_6BITS);
1367 		break;
1368 	case CS7:
1369 		SET(lcr, LCR_7BITS);
1370 		break;
1371 	case CS8:
1372 		SET(lcr, LCR_8BITS);
1373 		break;
1374 	}
1375 	if (ISSET(cflag, PARENB)) {
1376 		SET(lcr, LCR_PENAB);
1377 		if (!ISSET(cflag, PARODD))
1378 			SET(lcr, LCR_PEVEN);
1379 	}
1380 	if (ISSET(cflag, CSTOPB))
1381 		SET(lcr, LCR_STOPB);
1382 
1383 	return (lcr);
1384 }
1385 
1386 int
1387 comparam(struct tty *tp, struct termios *t)
1388 {
1389 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(tp->t_dev));
1390 	int ospeed;
1391 	u_char lcr;
1392 	int s;
1393 
1394 	if (COM_ISALIVE(sc) == 0)
1395 		return (EIO);
1396 
1397 #ifdef COM_HAYESP
1398 	if (sc->sc_type == COM_TYPE_HAYESP) {
1399 		int prescaler, speed;
1400 
1401 		/*
1402 		 * Calculate UART clock prescaler.  It should be in
1403 		 * range of 0 .. 3.
1404 		 */
1405 		for (prescaler = 0, speed = t->c_ospeed; prescaler < 4;
1406 		    prescaler++, speed /= 2)
1407 			if ((ospeed = comspeed(speed, sc->sc_frequency,
1408 					       sc->sc_type)) > 0)
1409 				break;
1410 
1411 		if (prescaler == 4)
1412 			return (EINVAL);
1413 		sc->sc_prescaler = prescaler;
1414 	} else
1415 #endif
1416 	ospeed = comspeed(t->c_ospeed, sc->sc_frequency, sc->sc_type);
1417 
1418 	/* Check requested parameters. */
1419 	if (ospeed < 0)
1420 		return (EINVAL);
1421 	if (t->c_ispeed && t->c_ispeed != t->c_ospeed)
1422 		return (EINVAL);
1423 
1424 	/*
1425 	 * For the console, always force CLOCAL and !HUPCL, so that the port
1426 	 * is always active.
1427 	 */
1428 	if (ISSET(sc->sc_swflags, TIOCFLAG_SOFTCAR) ||
1429 	    ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
1430 		SET(t->c_cflag, CLOCAL);
1431 		CLR(t->c_cflag, HUPCL);
1432 	}
1433 
1434 	/*
1435 	 * If there were no changes, don't do anything.  This avoids dropping
1436 	 * input and improves performance when all we did was frob things like
1437 	 * VMIN and VTIME.
1438 	 */
1439 	if (tp->t_ospeed == t->c_ospeed &&
1440 	    tp->t_cflag == t->c_cflag)
1441 		return (0);
1442 
1443 	lcr = ISSET(sc->sc_lcr, LCR_SBREAK) | cflag2lcr(t->c_cflag);
1444 
1445 	s = splserial();
1446 	COM_LOCK(sc);
1447 
1448 	sc->sc_lcr = lcr;
1449 
1450 	/*
1451 	 * If we're not in a mode that assumes a connection is present, then
1452 	 * ignore carrier changes.
1453 	 */
1454 	if (ISSET(t->c_cflag, CLOCAL | MDMBUF))
1455 		sc->sc_msr_dcd = 0;
1456 	else
1457 		sc->sc_msr_dcd = MSR_DCD;
1458 	/*
1459 	 * Set the flow control pins depending on the current flow control
1460 	 * mode.
1461 	 */
1462 	if (ISSET(t->c_cflag, CRTSCTS)) {
1463 		sc->sc_mcr_dtr = MCR_DTR;
1464 		sc->sc_mcr_rts = MCR_RTS;
1465 		sc->sc_msr_cts = MSR_CTS;
1466 		sc->sc_efr = EFR_AUTORTS | EFR_AUTOCTS;
1467 	} else if (ISSET(t->c_cflag, MDMBUF)) {
1468 		/*
1469 		 * For DTR/DCD flow control, make sure we don't toggle DTR for
1470 		 * carrier detection.
1471 		 */
1472 		sc->sc_mcr_dtr = 0;
1473 		sc->sc_mcr_rts = MCR_DTR;
1474 		sc->sc_msr_cts = MSR_DCD;
1475 		sc->sc_efr = 0;
1476 	} else {
1477 		/*
1478 		 * If no flow control, then always set RTS.  This will make
1479 		 * the other side happy if it mistakenly thinks we're doing
1480 		 * RTS/CTS flow control.
1481 		 */
1482 		sc->sc_mcr_dtr = MCR_DTR | MCR_RTS;
1483 		sc->sc_mcr_rts = 0;
1484 		sc->sc_msr_cts = 0;
1485 		sc->sc_efr = 0;
1486 		if (ISSET(sc->sc_mcr, MCR_DTR))
1487 			SET(sc->sc_mcr, MCR_RTS);
1488 		else
1489 			CLR(sc->sc_mcr, MCR_RTS);
1490 	}
1491 	sc->sc_msr_mask = sc->sc_msr_cts | sc->sc_msr_dcd;
1492 
1493 #if 0
1494 	if (ospeed == 0)
1495 		CLR(sc->sc_mcr, sc->sc_mcr_dtr);
1496 	else
1497 		SET(sc->sc_mcr, sc->sc_mcr_dtr);
1498 #endif
1499 
1500 	sc->sc_dlbl = ospeed;
1501 	sc->sc_dlbh = ospeed >> 8;
1502 
1503 	/*
1504 	 * Set the FIFO threshold based on the receive speed.
1505 	 *
1506 	 *  * If it's a low speed, it's probably a mouse or some other
1507 	 *    interactive device, so set the threshold low.
1508 	 *  * If it's a high speed, trim the trigger level down to prevent
1509 	 *    overflows.
1510 	 *  * Otherwise set it a bit higher.
1511 	 */
1512 	if (sc->sc_type == COM_TYPE_HAYESP)
1513 		sc->sc_fifo = FIFO_DMA_MODE | FIFO_ENABLE | FIFO_TRIGGER_8;
1514 	else if (ISSET(sc->sc_hwflags, COM_HW_FIFO))
1515 		sc->sc_fifo = FIFO_ENABLE |
1516 		    (t->c_ospeed <= 1200 ? FIFO_TRIGGER_1 : FIFO_TRIGGER_8);
1517 	else
1518 		sc->sc_fifo = 0;
1519 
1520 	/* And copy to tty. */
1521 	tp->t_ispeed = 0;
1522 	tp->t_ospeed = t->c_ospeed;
1523 	tp->t_cflag = t->c_cflag;
1524 
1525 	if (!sc->sc_heldchange) {
1526 		if (sc->sc_tx_busy) {
1527 			sc->sc_heldtbc = sc->sc_tbc;
1528 			sc->sc_tbc = 0;
1529 			sc->sc_heldchange = 1;
1530 		} else
1531 			com_loadchannelregs(sc);
1532 	}
1533 
1534 	if (!ISSET(t->c_cflag, CHWFLOW)) {
1535 		/* Disable the high water mark. */
1536 		sc->sc_r_hiwat = 0;
1537 		sc->sc_r_lowat = 0;
1538 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
1539 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1540 			com_schedrx(sc);
1541 		}
1542 		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED)) {
1543 			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED);
1544 			com_hwiflow(sc);
1545 		}
1546 	} else {
1547 		sc->sc_r_hiwat = com_rbuf_hiwat;
1548 		sc->sc_r_lowat = com_rbuf_lowat;
1549 	}
1550 
1551 	COM_UNLOCK(sc);
1552 	splx(s);
1553 
1554 	/*
1555 	 * Update the tty layer's idea of the carrier bit, in case we changed
1556 	 * CLOCAL or MDMBUF.  We don't hang up here; we only do that by
1557 	 * explicit request.
1558 	 */
1559 	(void) (*tp->t_linesw->l_modem)(tp, ISSET(sc->sc_msr, MSR_DCD));
1560 
1561 #ifdef COM_DEBUG
1562 	if (com_debug)
1563 		comstatus(sc, "comparam ");
1564 #endif
1565 
1566 	if (!ISSET(t->c_cflag, CHWFLOW)) {
1567 		if (sc->sc_tx_stopped) {
1568 			sc->sc_tx_stopped = 0;
1569 			comstart(tp);
1570 		}
1571 	}
1572 
1573 	return (0);
1574 }
1575 
1576 void
1577 com_iflush(struct com_softc *sc)
1578 {
1579 	bus_space_tag_t iot = sc->sc_iot;
1580 	bus_space_handle_t ioh = sc->sc_ioh;
1581 #ifdef DIAGNOSTIC
1582 	int reg;
1583 #endif
1584 	int timo;
1585 
1586 #ifdef DIAGNOSTIC
1587 	reg = 0xffff;
1588 #endif
1589 	timo = 50000;
1590 	/* flush any pending I/O */
1591 	while (ISSET(bus_space_read_1(iot, ioh, com_lsr), LSR_RXRDY)
1592 	    && --timo)
1593 #ifdef DIAGNOSTIC
1594 		reg =
1595 #else
1596 		    (void)
1597 #endif
1598 		    bus_space_read_1(iot, ioh, com_data);
1599 #ifdef DIAGNOSTIC
1600 	if (!timo)
1601 		printf("%s: com_iflush timeout %02x\n", sc->sc_dev.dv_xname,
1602 		       reg);
1603 #endif
1604 }
1605 
1606 void
1607 com_loadchannelregs(struct com_softc *sc)
1608 {
1609 	bus_space_tag_t iot = sc->sc_iot;
1610 	bus_space_handle_t ioh = sc->sc_ioh;
1611 
1612 	/* XXXXX necessary? */
1613 	com_iflush(sc);
1614 
1615 #ifdef COM_PXA2X0
1616 	if (sc->sc_type == COM_TYPE_PXA2x0)
1617 		bus_space_write_1(iot, ioh, com_ier, IER_EUART);
1618 	else
1619 #endif
1620 		bus_space_write_1(iot, ioh, com_ier, 0);
1621 
1622 	if (ISSET(sc->sc_hwflags, COM_HW_FLOW)) {
1623 		bus_space_write_1(iot, ioh, com_lcr, LCR_EERS);
1624 		bus_space_write_1(iot, ioh, com_efr, sc->sc_efr);
1625 	}
1626 	bus_space_write_1(iot, ioh, com_lcr, sc->sc_lcr | LCR_DLAB);
1627 	bus_space_write_1(iot, ioh, com_dlbl, sc->sc_dlbl);
1628 	bus_space_write_1(iot, ioh, com_dlbh, sc->sc_dlbh);
1629 	bus_space_write_1(iot, ioh, com_lcr, sc->sc_lcr);
1630 	bus_space_write_1(iot, ioh, com_mcr, sc->sc_mcr_active = sc->sc_mcr);
1631 	bus_space_write_1(iot, ioh, com_fifo, sc->sc_fifo);
1632 #ifdef COM_HAYESP
1633 	if (sc->sc_type == COM_TYPE_HAYESP) {
1634 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD1,
1635 		    HAYESP_SETPRESCALER);
1636 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
1637 		    sc->sc_prescaler);
1638 	}
1639 #endif
1640 
1641 	bus_space_write_1(iot, ioh, com_ier, sc->sc_ier);
1642 }
1643 
1644 int
1645 comhwiflow(struct tty *tp, int block)
1646 {
1647 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(tp->t_dev));
1648 	int s;
1649 
1650 	if (COM_ISALIVE(sc) == 0)
1651 		return (0);
1652 
1653 	if (sc->sc_mcr_rts == 0)
1654 		return (0);
1655 
1656 	s = splserial();
1657 	COM_LOCK(sc);
1658 
1659 	if (block) {
1660 		if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1661 			SET(sc->sc_rx_flags, RX_TTY_BLOCKED);
1662 			com_hwiflow(sc);
1663 		}
1664 	} else {
1665 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
1666 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1667 			com_schedrx(sc);
1668 		}
1669 		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1670 			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED);
1671 			com_hwiflow(sc);
1672 		}
1673 	}
1674 
1675 	COM_UNLOCK(sc);
1676 	splx(s);
1677 	return (1);
1678 }
1679 
1680 /*
1681  * (un)block input via hw flowcontrol
1682  */
1683 void
1684 com_hwiflow(struct com_softc *sc)
1685 {
1686 	bus_space_tag_t iot = sc->sc_iot;
1687 	bus_space_handle_t ioh = sc->sc_ioh;
1688 
1689 	if (sc->sc_mcr_rts == 0)
1690 		return;
1691 
1692 	if (ISSET(sc->sc_rx_flags, RX_ANY_BLOCK)) {
1693 		CLR(sc->sc_mcr, sc->sc_mcr_rts);
1694 		CLR(sc->sc_mcr_active, sc->sc_mcr_rts);
1695 	} else {
1696 		SET(sc->sc_mcr, sc->sc_mcr_rts);
1697 		SET(sc->sc_mcr_active, sc->sc_mcr_rts);
1698 	}
1699 	bus_space_write_1(iot, ioh, com_mcr, sc->sc_mcr_active);
1700 }
1701 
1702 
1703 void
1704 comstart(struct tty *tp)
1705 {
1706 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(tp->t_dev));
1707 	bus_space_tag_t iot = sc->sc_iot;
1708 	bus_space_handle_t ioh = sc->sc_ioh;
1709 	int s;
1710 
1711 	if (COM_ISALIVE(sc) == 0)
1712 		return;
1713 
1714 	s = spltty();
1715 	if (ISSET(tp->t_state, TS_BUSY | TS_TIMEOUT | TS_TTSTOP))
1716 		goto out;
1717 	if (sc->sc_tx_stopped)
1718 		goto out;
1719 
1720 	if (tp->t_outq.c_cc <= tp->t_lowat) {
1721 		if (ISSET(tp->t_state, TS_ASLEEP)) {
1722 			CLR(tp->t_state, TS_ASLEEP);
1723 			wakeup(&tp->t_outq);
1724 		}
1725 		selwakeup(&tp->t_wsel);
1726 		if (tp->t_outq.c_cc == 0)
1727 			goto out;
1728 	}
1729 
1730 	/* Grab the first contiguous region of buffer space. */
1731 	{
1732 		u_char *tba;
1733 		int tbc;
1734 
1735 		tba = tp->t_outq.c_cf;
1736 		tbc = ndqb(&tp->t_outq, 0);
1737 
1738 		(void)splserial();
1739 		COM_LOCK(sc);
1740 
1741 		sc->sc_tba = tba;
1742 		sc->sc_tbc = tbc;
1743 	}
1744 
1745 	SET(tp->t_state, TS_BUSY);
1746 	sc->sc_tx_busy = 1;
1747 
1748 	/* Enable transmit completion interrupts if necessary. */
1749 	if (!ISSET(sc->sc_ier, IER_ETXRDY)) {
1750 		SET(sc->sc_ier, IER_ETXRDY);
1751 		bus_space_write_1(iot, ioh, com_ier, sc->sc_ier);
1752 	}
1753 
1754 #if 0
1755 	/* Output the first chunk of the contiguous buffer. */
1756 	if (!ISSET(sc->sc_hwflags, COM_HW_NO_TXPRELOAD)) {
1757 		u_int n;
1758 
1759 		n = sc->sc_tbc;
1760 		if (n > sc->sc_fifolen)
1761 			n = sc->sc_fifolen;
1762 		bus_space_write_multi_1(iot, ioh, com_data, sc->sc_tba, n);
1763 		sc->sc_tbc -= n;
1764 		sc->sc_tba += n;
1765 	}
1766 #endif
1767 	COM_UNLOCK(sc);
1768 out:
1769 	splx(s);
1770 	return;
1771 }
1772 
1773 /*
1774  * Stop output on a line.
1775  */
1776 void
1777 comstop(struct tty *tp, int flag)
1778 {
1779 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(tp->t_dev));
1780 	int s;
1781 
1782 	s = splserial();
1783 	COM_LOCK(sc);
1784 	if (ISSET(tp->t_state, TS_BUSY)) {
1785 		/* Stop transmitting at the next chunk. */
1786 		sc->sc_tbc = 0;
1787 		sc->sc_heldtbc = 0;
1788 		if (!ISSET(tp->t_state, TS_TTSTOP))
1789 			SET(tp->t_state, TS_FLUSH);
1790 	}
1791 	COM_UNLOCK(sc);
1792 	splx(s);
1793 }
1794 
1795 void
1796 comdiag(void *arg)
1797 {
1798 	struct com_softc *sc = arg;
1799 	int overflows, floods;
1800 	int s;
1801 
1802 	s = splserial();
1803 	COM_LOCK(sc);
1804 	overflows = sc->sc_overflows;
1805 	sc->sc_overflows = 0;
1806 	floods = sc->sc_floods;
1807 	sc->sc_floods = 0;
1808 	sc->sc_errors = 0;
1809 	COM_UNLOCK(sc);
1810 	splx(s);
1811 
1812 	log(LOG_WARNING, "%s: %d silo overflow%s, %d ibuf flood%s\n",
1813 	    sc->sc_dev.dv_xname,
1814 	    overflows, overflows == 1 ? "" : "s",
1815 	    floods, floods == 1 ? "" : "s");
1816 }
1817 
1818 integrate void
1819 com_rxsoft(struct com_softc *sc, struct tty *tp)
1820 {
1821 	int (*rint)(int, struct tty *) = tp->t_linesw->l_rint;
1822 	u_char *get, *end;
1823 	u_int cc, scc;
1824 	u_char lsr;
1825 	int code;
1826 	int s;
1827 
1828 	end = sc->sc_ebuf;
1829 	get = sc->sc_rbget;
1830 	scc = cc = com_rbuf_size - sc->sc_rbavail;
1831 
1832 	if (cc == com_rbuf_size) {
1833 		sc->sc_floods++;
1834 		if (sc->sc_errors++ == 0)
1835 			callout_reset(&sc->sc_diag_callout, 60 * hz,
1836 			    comdiag, sc);
1837 	}
1838 
1839 	/* If not yet open, drop the entire buffer content here */
1840 	if (!ISSET(tp->t_state, TS_ISOPEN)) {
1841 		get += cc << 1;
1842 		if (get >= end)
1843 			get -= com_rbuf_size << 1;
1844 		cc = 0;
1845 	}
1846 	while (cc) {
1847 		code = get[0];
1848 		lsr = get[1];
1849 		if (ISSET(lsr, LSR_OE | LSR_BI | LSR_FE | LSR_PE)) {
1850 			if (ISSET(lsr, LSR_OE)) {
1851 				sc->sc_overflows++;
1852 				if (sc->sc_errors++ == 0)
1853 					callout_reset(&sc->sc_diag_callout,
1854 					    60 * hz, comdiag, sc);
1855 			}
1856 			if (ISSET(lsr, LSR_BI | LSR_FE))
1857 				SET(code, TTY_FE);
1858 			if (ISSET(lsr, LSR_PE))
1859 				SET(code, TTY_PE);
1860 		}
1861 		if ((*rint)(code, tp) == -1) {
1862 			/*
1863 			 * The line discipline's buffer is out of space.
1864 			 */
1865 			if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1866 				/*
1867 				 * We're either not using flow control, or the
1868 				 * line discipline didn't tell us to block for
1869 				 * some reason.  Either way, we have no way to
1870 				 * know when there's more space available, so
1871 				 * just drop the rest of the data.
1872 				 */
1873 				get += cc << 1;
1874 				if (get >= end)
1875 					get -= com_rbuf_size << 1;
1876 				cc = 0;
1877 			} else {
1878 				/*
1879 				 * Don't schedule any more receive processing
1880 				 * until the line discipline tells us there's
1881 				 * space available (through comhwiflow()).
1882 				 * Leave the rest of the data in the input
1883 				 * buffer.
1884 				 */
1885 				SET(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1886 			}
1887 			break;
1888 		}
1889 		get += 2;
1890 		if (get >= end)
1891 			get = sc->sc_rbuf;
1892 		cc--;
1893 	}
1894 
1895 	if (cc != scc) {
1896 		sc->sc_rbget = get;
1897 		s = splserial();
1898 		COM_LOCK(sc);
1899 
1900 		cc = sc->sc_rbavail += scc - cc;
1901 		/* Buffers should be ok again, release possible block. */
1902 		if (cc >= sc->sc_r_lowat) {
1903 			if (ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
1904 				CLR(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
1905 				SET(sc->sc_ier, IER_ERXRDY);
1906 #ifdef COM_PXA2X0
1907 				if (sc->sc_type == COM_TYPE_PXA2x0)
1908 					SET(sc->sc_ier, IER_ERXTOUT);
1909 #endif
1910 				bus_space_write_1(sc->sc_iot, sc->sc_ioh,
1911 				    com_ier, sc->sc_ier);
1912 			}
1913 			if (ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED)) {
1914 				CLR(sc->sc_rx_flags, RX_IBUF_BLOCKED);
1915 				com_hwiflow(sc);
1916 			}
1917 		}
1918 		COM_UNLOCK(sc);
1919 		splx(s);
1920 	}
1921 }
1922 
1923 integrate void
1924 com_txsoft(struct com_softc *sc, struct tty *tp)
1925 {
1926 
1927 	CLR(tp->t_state, TS_BUSY);
1928 	if (ISSET(tp->t_state, TS_FLUSH))
1929 		CLR(tp->t_state, TS_FLUSH);
1930 	else
1931 		ndflush(&tp->t_outq, (int)(sc->sc_tba - tp->t_outq.c_cf));
1932 	(*tp->t_linesw->l_start)(tp);
1933 }
1934 
1935 integrate void
1936 com_stsoft(struct com_softc *sc, struct tty *tp)
1937 {
1938 	u_char msr, delta;
1939 	int s;
1940 
1941 	s = splserial();
1942 	COM_LOCK(sc);
1943 	msr = sc->sc_msr;
1944 	delta = sc->sc_msr_delta;
1945 	sc->sc_msr_delta = 0;
1946 	COM_UNLOCK(sc);
1947 	splx(s);
1948 
1949 	if (ISSET(delta, sc->sc_msr_dcd)) {
1950 		/*
1951 		 * Inform the tty layer that carrier detect changed.
1952 		 */
1953 		(void) (*tp->t_linesw->l_modem)(tp, ISSET(msr, MSR_DCD));
1954 	}
1955 
1956 	if (ISSET(delta, sc->sc_msr_cts)) {
1957 		/* Block or unblock output according to flow control. */
1958 		if (ISSET(msr, sc->sc_msr_cts)) {
1959 			sc->sc_tx_stopped = 0;
1960 			(*tp->t_linesw->l_start)(tp);
1961 		} else {
1962 			sc->sc_tx_stopped = 1;
1963 		}
1964 	}
1965 
1966 #ifdef COM_DEBUG
1967 	if (com_debug)
1968 		comstatus(sc, "com_stsoft");
1969 #endif
1970 }
1971 
1972 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
1973 void
1974 comsoft(void *arg)
1975 {
1976 	struct com_softc *sc = arg;
1977 	struct tty *tp;
1978 
1979 	if (COM_ISALIVE(sc) == 0)
1980 		return;
1981 
1982 	{
1983 #else
1984 void
1985 #ifndef __NO_SOFT_SERIAL_INTERRUPT
1986 comsoft(void)
1987 #else
1988 comsoft(void *arg)
1989 #endif
1990 {
1991 	struct com_softc	*sc;
1992 	struct tty	*tp;
1993 	int	unit;
1994 #ifdef __NO_SOFT_SERIAL_INTERRUPT
1995 	int s;
1996 
1997 	s = splsoftserial();
1998 	com_softintr_scheduled = 0;
1999 #endif
2000 
2001 	for (unit = 0; unit < com_cd.cd_ndevs; unit++) {
2002 		sc = device_lookup(&com_cd, unit);
2003 		if (sc == NULL || !ISSET(sc->sc_hwflags, COM_HW_DEV_OK))
2004 			continue;
2005 
2006 		if (COM_ISALIVE(sc) == 0)
2007 			continue;
2008 
2009 		tp = sc->sc_tty;
2010 		if (tp == NULL)
2011 			continue;
2012 		if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0)
2013 			continue;
2014 #endif
2015 		tp = sc->sc_tty;
2016 
2017 		if (sc->sc_rx_ready) {
2018 			sc->sc_rx_ready = 0;
2019 			com_rxsoft(sc, tp);
2020 		}
2021 
2022 		if (sc->sc_st_check) {
2023 			sc->sc_st_check = 0;
2024 			com_stsoft(sc, tp);
2025 		}
2026 
2027 		if (sc->sc_tx_done) {
2028 			sc->sc_tx_done = 0;
2029 			com_txsoft(sc, tp);
2030 		}
2031 	}
2032 
2033 #ifndef __HAVE_GENERIC_SOFT_INTERRUPTS
2034 #ifdef __NO_SOFT_SERIAL_INTERRUPT
2035 	splx(s);
2036 #endif
2037 #endif
2038 }
2039 
2040 #ifdef __ALIGN_BRACKET_LEVEL_FOR_CTAGS
2041 	/* there has got to be a better way to do comsoft() */
2042 }}
2043 #endif
2044 
2045 int
2046 comintr(void *arg)
2047 {
2048 	struct com_softc *sc = arg;
2049 	bus_space_tag_t iot = sc->sc_iot;
2050 	bus_space_handle_t ioh = sc->sc_ioh;
2051 	u_char *put, *end;
2052 	u_int cc;
2053 	u_char lsr, iir;
2054 
2055 	if (COM_ISALIVE(sc) == 0)
2056 		return (0);
2057 
2058 	COM_LOCK(sc);
2059 	iir = bus_space_read_1(iot, ioh, com_iir);
2060 	if (ISSET(iir, IIR_NOPEND)) {
2061 		COM_UNLOCK(sc);
2062 		return (0);
2063 	}
2064 
2065 	end = sc->sc_ebuf;
2066 	put = sc->sc_rbput;
2067 	cc = sc->sc_rbavail;
2068 
2069 again:	do {
2070 		u_char	msr, delta;
2071 
2072 		lsr = bus_space_read_1(iot, ioh, com_lsr);
2073 		if (ISSET(lsr, LSR_BI)) {
2074 			int cn_trapped = 0;
2075 
2076 			cn_check_magic(sc->sc_tty->t_dev,
2077 				       CNC_BREAK, com_cnm_state);
2078 			if (cn_trapped)
2079 				continue;
2080 #if defined(KGDB) && !defined(DDB)
2081 			if (ISSET(sc->sc_hwflags, COM_HW_KGDB)) {
2082 				kgdb_connect(1);
2083 				continue;
2084 			}
2085 #endif
2086 		}
2087 
2088 		if (ISSET(lsr, LSR_RCV_MASK) &&
2089 		    !ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
2090 			while (cc > 0) {
2091 				int cn_trapped = 0;
2092 				put[0] = bus_space_read_1(iot, ioh, com_data);
2093 				put[1] = lsr;
2094 				cn_check_magic(sc->sc_tty->t_dev,
2095 					       put[0], com_cnm_state);
2096 				if (cn_trapped)
2097 					goto next;
2098 				put += 2;
2099 				if (put >= end)
2100 					put = sc->sc_rbuf;
2101 				cc--;
2102 			next:
2103 				lsr = bus_space_read_1(iot, ioh, com_lsr);
2104 				if (!ISSET(lsr, LSR_RCV_MASK))
2105 					break;
2106 			}
2107 
2108 			/*
2109 			 * Current string of incoming characters ended because
2110 			 * no more data was available or we ran out of space.
2111 			 * Schedule a receive event if any data was received.
2112 			 * If we're out of space, turn off receive interrupts.
2113 			 */
2114 			sc->sc_rbput = put;
2115 			sc->sc_rbavail = cc;
2116 			if (!ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED))
2117 				sc->sc_rx_ready = 1;
2118 
2119 			/*
2120 			 * See if we are in danger of overflowing a buffer. If
2121 			 * so, use hardware flow control to ease the pressure.
2122 			 */
2123 			if (!ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED) &&
2124 			    cc < sc->sc_r_hiwat) {
2125 				SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
2126 				com_hwiflow(sc);
2127 			}
2128 
2129 			/*
2130 			 * If we're out of space, disable receive interrupts
2131 			 * until the queue has drained a bit.
2132 			 */
2133 			if (!cc) {
2134 				SET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
2135 #ifdef COM_PXA2X0
2136 				if (sc->sc_type == COM_TYPE_PXA2x0)
2137 					CLR(sc->sc_ier, IER_ERXRDY|IER_ERXTOUT);
2138 				else
2139 #endif
2140 					CLR(sc->sc_ier, IER_ERXRDY);
2141 				bus_space_write_1(iot, ioh, com_ier,
2142 				    sc->sc_ier);
2143 			}
2144 		} else {
2145 			if ((iir & (IIR_RXRDY|IIR_TXRDY)) == IIR_RXRDY) {
2146 				(void) bus_space_read_1(iot, ioh, com_data);
2147 				continue;
2148 			}
2149 		}
2150 
2151 		msr = bus_space_read_1(iot, ioh, com_msr);
2152 		delta = msr ^ sc->sc_msr;
2153 		sc->sc_msr = msr;
2154 		/*
2155 		 * Pulse-per-second (PSS) signals on edge of DCD?
2156 		 * Process these even if line discipline is ignoring DCD.
2157 		 */
2158 		if (delta & sc->sc_ppsmask) {
2159 			struct timeval tv;
2160 		    	if ((msr & sc->sc_ppsmask) == sc->sc_ppsassert) {
2161 				/* XXX nanotime() */
2162 				microtime(&tv);
2163 				TIMEVAL_TO_TIMESPEC(&tv,
2164 				    &sc->ppsinfo.assert_timestamp);
2165 				if (sc->ppsparam.mode & PPS_OFFSETASSERT) {
2166 					timespecadd(&sc->ppsinfo.assert_timestamp,
2167 					    &sc->ppsparam.assert_offset,
2168 						    &sc->ppsinfo.assert_timestamp);
2169 				}
2170 
2171 #ifdef PPS_SYNC
2172 				if (pps_kc_hardpps_source == sc &&
2173 				    pps_kc_hardpps_mode & PPS_CAPTUREASSERT) {
2174 					hardpps(&tv, tv.tv_usec);
2175 				}
2176 #endif
2177 				sc->ppsinfo.assert_sequence++;
2178 				sc->ppsinfo.current_mode = sc->ppsparam.mode;
2179 
2180 			} else if ((msr & sc->sc_ppsmask) == sc->sc_ppsclear) {
2181 				/* XXX nanotime() */
2182 				microtime(&tv);
2183 				TIMEVAL_TO_TIMESPEC(&tv,
2184 				    &sc->ppsinfo.clear_timestamp);
2185 				if (sc->ppsparam.mode & PPS_OFFSETCLEAR) {
2186 					timespecadd(&sc->ppsinfo.clear_timestamp,
2187 					    &sc->ppsparam.clear_offset,
2188 					    &sc->ppsinfo.clear_timestamp);
2189 				}
2190 
2191 #ifdef PPS_SYNC
2192 				if (pps_kc_hardpps_source == sc &&
2193 				    pps_kc_hardpps_mode & PPS_CAPTURECLEAR) {
2194 					hardpps(&tv, tv.tv_usec);
2195 				}
2196 #endif
2197 				sc->ppsinfo.clear_sequence++;
2198 				sc->ppsinfo.current_mode = sc->ppsparam.mode;
2199 			}
2200 		}
2201 
2202 		/*
2203 		 * Process normal status changes
2204 		 */
2205 		if (ISSET(delta, sc->sc_msr_mask)) {
2206 			SET(sc->sc_msr_delta, delta);
2207 
2208 			/*
2209 			 * Stop output immediately if we lose the output
2210 			 * flow control signal or carrier detect.
2211 			 */
2212 			if (ISSET(~msr, sc->sc_msr_mask)) {
2213 				sc->sc_tbc = 0;
2214 				sc->sc_heldtbc = 0;
2215 #ifdef COM_DEBUG
2216 				if (com_debug)
2217 					comstatus(sc, "comintr  ");
2218 #endif
2219 			}
2220 
2221 			sc->sc_st_check = 1;
2222 		}
2223 	} while (!ISSET((iir =
2224 	    bus_space_read_1(iot, ioh, com_iir)), IIR_NOPEND) &&
2225 	    /*
2226 	     * Since some device (e.g., ST16C1550) doesn't clear IIR_TXRDY
2227 	     * by IIR read, so we can't do this way: `process all interrupts,
2228 	     * then do TX if possble'.
2229 	     */
2230 	    (iir & IIR_IMASK) != IIR_TXRDY);
2231 
2232 	/*
2233 	 * Read LSR again, since there may be an interrupt between
2234 	 * the last LSR read and IIR read above.
2235 	 */
2236 	lsr = bus_space_read_1(iot, ioh, com_lsr);
2237 
2238 	/*
2239 	 * See if data can be transmitted as well.
2240 	 * Schedule tx done event if no data left
2241 	 * and tty was marked busy.
2242 	 */
2243 	if (ISSET(lsr, LSR_TXRDY)) {
2244 		/*
2245 		 * If we've delayed a parameter change, do it now, and restart
2246 		 * output.
2247 		 */
2248 		if (sc->sc_heldchange) {
2249 			com_loadchannelregs(sc);
2250 			sc->sc_heldchange = 0;
2251 			sc->sc_tbc = sc->sc_heldtbc;
2252 			sc->sc_heldtbc = 0;
2253 		}
2254 
2255 		/* Output the next chunk of the contiguous buffer, if any. */
2256 		if (sc->sc_tbc > 0) {
2257 			u_int n;
2258 
2259 			n = sc->sc_tbc;
2260 			if (n > sc->sc_fifolen)
2261 				n = sc->sc_fifolen;
2262 			bus_space_write_multi_1(iot, ioh, com_data, sc->sc_tba, n);
2263 			sc->sc_tbc -= n;
2264 			sc->sc_tba += n;
2265 		} else {
2266 			/* Disable transmit completion interrupts if necessary. */
2267 			if (ISSET(sc->sc_ier, IER_ETXRDY)) {
2268 				CLR(sc->sc_ier, IER_ETXRDY);
2269 				bus_space_write_1(iot, ioh, com_ier, sc->sc_ier);
2270 			}
2271 			if (sc->sc_tx_busy) {
2272 				sc->sc_tx_busy = 0;
2273 				sc->sc_tx_done = 1;
2274 			}
2275 		}
2276 	}
2277 
2278 	if (!ISSET((iir = bus_space_read_1(iot, ioh, com_iir)), IIR_NOPEND))
2279 		goto again;
2280 
2281 	COM_UNLOCK(sc);
2282 
2283 	/* Wake up the poller. */
2284 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
2285 	softintr_schedule(sc->sc_si);
2286 #else
2287 #ifndef __NO_SOFT_SERIAL_INTERRUPT
2288 	setsoftserial();
2289 #else
2290 	if (!com_softintr_scheduled) {
2291 		com_softintr_scheduled = 1;
2292 		callout_reset(&comsoft_callout, 1, comsoft, NULL);
2293 	}
2294 #endif
2295 #endif
2296 
2297 #if NRND > 0 && defined(RND_COM)
2298 	rnd_add_uint32(&sc->rnd_source, iir | lsr);
2299 #endif
2300 
2301 	return (1);
2302 }
2303 
2304 /*
2305  * The following functions are polled getc and putc routines, shared
2306  * by the console and kgdb glue.
2307  *
2308  * The read-ahead code is so that you can detect pending in-band
2309  * cn_magic in polled mode while doing output rather than having to
2310  * wait until the kernel decides it needs input.
2311  */
2312 
2313 #define MAX_READAHEAD	20
2314 static int com_readahead[MAX_READAHEAD];
2315 static int com_readaheadcount = 0;
2316 
2317 int
2318 com_common_getc(dev_t dev, bus_space_tag_t iot, bus_space_handle_t ioh)
2319 {
2320 	int s = splserial();
2321 	u_char stat, c;
2322 
2323 	/* got a character from reading things earlier */
2324 	if (com_readaheadcount > 0) {
2325 		int i;
2326 
2327 		c = com_readahead[0];
2328 		for (i = 1; i < com_readaheadcount; i++) {
2329 			com_readahead[i-1] = com_readahead[i];
2330 		}
2331 		com_readaheadcount--;
2332 		splx(s);
2333 		return (c);
2334 	}
2335 
2336 	/* block until a character becomes available */
2337 	while (!ISSET(stat = bus_space_read_1(iot, ioh, com_lsr), LSR_RXRDY))
2338 		;
2339 
2340 	c = bus_space_read_1(iot, ioh, com_data);
2341 	stat = bus_space_read_1(iot, ioh, com_iir);
2342 	{
2343 		int cn_trapped = 0; /* unused */
2344 #ifdef DDB
2345 		extern int db_active;
2346 		if (!db_active)
2347 #endif
2348 			cn_check_magic(dev, c, com_cnm_state);
2349 	}
2350 	splx(s);
2351 	return (c);
2352 }
2353 
2354 void
2355 com_common_putc(dev_t dev, bus_space_tag_t iot, bus_space_handle_t ioh, int c)
2356 {
2357 	int s = splserial();
2358 	int cin, stat, timo;
2359 
2360 	if (com_readaheadcount < MAX_READAHEAD
2361 	     && ISSET(stat = bus_space_read_1(iot, ioh, com_lsr), LSR_RXRDY)) {
2362 		int cn_trapped = 0;
2363 		cin = bus_space_read_1(iot, ioh, com_data);
2364 		stat = bus_space_read_1(iot, ioh, com_iir);
2365 		cn_check_magic(dev, cin, com_cnm_state);
2366 		com_readahead[com_readaheadcount++] = cin;
2367 	}
2368 
2369 	/* wait for any pending transmission to finish */
2370 	timo = 150000;
2371 	while (!ISSET(bus_space_read_1(iot, ioh, com_lsr), LSR_TXRDY) && --timo)
2372 		continue;
2373 
2374 	bus_space_write_1(iot, ioh, com_data, c);
2375 	COM_BARRIER(iot, ioh, BR | BW);
2376 
2377 	splx(s);
2378 }
2379 
2380 /*
2381  * Initialize UART for use as console or KGDB line.
2382  */
2383 int
2384 cominit(bus_space_tag_t iot, bus_addr_t iobase, int rate, int frequency,
2385     int type, tcflag_t cflag, bus_space_handle_t *iohp)
2386 {
2387 	bus_space_handle_t ioh;
2388 
2389 	if (bus_space_map(iot, iobase, COM_NPORTS, 0, &ioh))
2390 		return (ENOMEM); /* ??? */
2391 
2392 	bus_space_write_1(iot, ioh, com_lcr, LCR_EERS);
2393 	bus_space_write_1(iot, ioh, com_efr, 0);
2394 	bus_space_write_1(iot, ioh, com_lcr, LCR_DLAB);
2395 	rate = comspeed(rate, frequency, type);
2396 	bus_space_write_1(iot, ioh, com_dlbl, rate);
2397 	bus_space_write_1(iot, ioh, com_dlbh, rate >> 8);
2398 	bus_space_write_1(iot, ioh, com_lcr, cflag2lcr(cflag));
2399 	bus_space_write_1(iot, ioh, com_mcr, MCR_DTR | MCR_RTS);
2400 	bus_space_write_1(iot, ioh, com_fifo,
2401 	    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_1);
2402 #ifdef COM_PXA2X0
2403 	if (type == COM_TYPE_PXA2x0)
2404 		bus_space_write_1(iot, ioh, com_ier, IER_EUART);
2405 	else
2406 #endif
2407 		bus_space_write_1(iot, ioh, com_ier, 0);
2408 
2409 	*iohp = ioh;
2410 	return (0);
2411 }
2412 
2413 /*
2414  * Following are all routines needed for COM to act as console
2415  */
2416 struct consdev comcons = {
2417 	NULL, NULL, comcngetc, comcnputc, comcnpollc, NULL, NULL, NULL,
2418 	NODEV, CN_NORMAL
2419 };
2420 
2421 
2422 int
2423 comcnattach(bus_space_tag_t iot, bus_addr_t iobase, int rate, int frequency,
2424     int type, tcflag_t cflag)
2425 {
2426 	int res;
2427 
2428 	res = cominit(iot, iobase, rate, frequency, type, cflag, &comconsioh);
2429 	if (res)
2430 		return (res);
2431 
2432 	cn_tab = &comcons;
2433 	cn_init_magic(&com_cnm_state);
2434 	cn_set_magic("\047\001"); /* default magic is BREAK */
2435 
2436 	comconstag = iot;
2437 	comconsaddr = iobase;
2438 	comconsrate = rate;
2439 	comconscflag = cflag;
2440 
2441 	return (0);
2442 }
2443 
2444 int
2445 comcngetc(dev_t dev)
2446 {
2447 
2448 	return (com_common_getc(dev, comconstag, comconsioh));
2449 }
2450 
2451 /*
2452  * Console kernel output character routine.
2453  */
2454 void
2455 comcnputc(dev_t dev, int c)
2456 {
2457 
2458 	com_common_putc(dev, comconstag, comconsioh, c);
2459 }
2460 
2461 void
2462 comcnpollc(dev_t dev, int on)
2463 {
2464 
2465 }
2466 
2467 #ifdef KGDB
2468 int
2469 com_kgdb_attach(bus_space_tag_t iot, bus_addr_t iobase, int rate,
2470     int frequency, int type, tcflag_t cflag)
2471 {
2472 	int res;
2473 
2474 	if (iot == comconstag && iobase == comconsaddr) {
2475 #if !defined(DDB)
2476 		return (EBUSY); /* cannot share with console */
2477 #else
2478 		com_kgdb_ioh = comconsioh;
2479 #endif
2480 	} else {
2481 		res = cominit(iot, iobase, rate, frequency, type, cflag,
2482 			      &com_kgdb_ioh);
2483 		if (res)
2484 			return (res);
2485 
2486 		/*
2487 		 * XXXfvdl this shouldn't be needed, but the cn_magic goo
2488 		 * expects this to be initialized
2489 		 */
2490 		cn_init_magic(&com_cnm_state);
2491 		cn_set_magic("\047\001");
2492 	}
2493 
2494 	kgdb_attach(com_kgdb_getc, com_kgdb_putc, NULL);
2495 	kgdb_dev = 123; /* unneeded, only to satisfy some tests */
2496 
2497 	com_kgdb_iot = iot;
2498 	com_kgdb_addr = iobase;
2499 
2500 	return (0);
2501 }
2502 
2503 /* ARGSUSED */
2504 int
2505 com_kgdb_getc(void *arg)
2506 {
2507 
2508 	return (com_common_getc(NODEV, com_kgdb_iot, com_kgdb_ioh));
2509 }
2510 
2511 /* ARGSUSED */
2512 void
2513 com_kgdb_putc(void *arg, int c)
2514 {
2515 
2516 	com_common_putc(NODEV, com_kgdb_iot, com_kgdb_ioh, c);
2517 }
2518 #endif /* KGDB */
2519 
2520 /* helper function to identify the com ports used by
2521  console or KGDB (and not yet autoconf attached) */
2522 int
2523 com_is_console(bus_space_tag_t iot, bus_addr_t iobase, bus_space_handle_t *ioh)
2524 {
2525 	bus_space_handle_t help;
2526 
2527 	if (!comconsattached &&
2528 	    iot == comconstag && iobase == comconsaddr)
2529 		help = comconsioh;
2530 #ifdef KGDB
2531 	else if (!com_kgdb_attached &&
2532 	    iot == com_kgdb_iot && iobase == com_kgdb_addr)
2533 		help = com_kgdb_ioh;
2534 #endif
2535 	else
2536 		return (0);
2537 
2538 	if (ioh)
2539 		*ioh = help;
2540 	return (1);
2541 }
2542