xref: /netbsd-src/sys/dev/ic/com.c (revision 7788a0781fe6ff2cce37368b4578a7ade0850cb1)
1 /* $NetBSD: com.c,v 1.312 2013/07/27 06:54:35 kiyohara Exp $ */
2 
3 /*-
4  * Copyright (c) 1998, 1999, 2004, 2008 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  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 /*
33  * Copyright (c) 1991 The Regents of the University of California.
34  * All rights reserved.
35  *
36  * Redistribution and use in source and binary forms, with or without
37  * modification, are permitted provided that the following conditions
38  * are met:
39  * 1. Redistributions of source code must retain the above copyright
40  *    notice, this list of conditions and the following disclaimer.
41  * 2. Redistributions in binary form must reproduce the above copyright
42  *    notice, this list of conditions and the following disclaimer in the
43  *    documentation and/or other materials provided with the distribution.
44  * 3. Neither the name of the University nor the names of its contributors
45  *    may be used to endorse or promote products derived from this software
46  *    without specific prior written permission.
47  *
48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
58  * SUCH DAMAGE.
59  *
60  *	@(#)com.c	7.5 (Berkeley) 5/16/91
61  */
62 
63 /*
64  * COM driver, uses National Semiconductor NS16450/NS16550AF UART
65  * Supports automatic hardware flow control on StarTech ST16C650A UART
66  */
67 
68 #include <sys/cdefs.h>
69 __KERNEL_RCSID(0, "$NetBSD: com.c,v 1.312 2013/07/27 06:54:35 kiyohara Exp $");
70 
71 #include "opt_com.h"
72 #include "opt_ddb.h"
73 #include "opt_kgdb.h"
74 #include "opt_lockdebug.h"
75 #include "opt_multiprocessor.h"
76 #include "opt_ntp.h"
77 
78 #include "rnd.h"
79 
80 /* The COM16650 option was renamed to COM_16650. */
81 #ifdef COM16650
82 #error Obsolete COM16650 option; use COM_16650 instead.
83 #endif
84 
85 /*
86  * Override cnmagic(9) macro before including <sys/systm.h>.
87  * We need to know if cn_check_magic triggered debugger, so set a flag.
88  * Callers of cn_check_magic must declare int cn_trapped = 0;
89  * XXX: this is *ugly*!
90  */
91 #define cn_trap()				\
92 	do {					\
93 		console_debugger();		\
94 		cn_trapped = 1;			\
95 	} while (/* CONSTCOND */ 0)
96 
97 #include <sys/param.h>
98 #include <sys/systm.h>
99 #include <sys/ioctl.h>
100 #include <sys/select.h>
101 #include <sys/poll.h>
102 #include <sys/tty.h>
103 #include <sys/proc.h>
104 #include <sys/conf.h>
105 #include <sys/file.h>
106 #include <sys/uio.h>
107 #include <sys/kernel.h>
108 #include <sys/syslog.h>
109 #include <sys/device.h>
110 #include <sys/malloc.h>
111 #include <sys/timepps.h>
112 #include <sys/vnode.h>
113 #include <sys/kauth.h>
114 #include <sys/intr.h>
115 #ifdef RND_COM
116 #include <sys/rnd.h>
117 #endif
118 
119 
120 #include <sys/bus.h>
121 
122 #include <dev/ic/comreg.h>
123 #include <dev/ic/comvar.h>
124 #include <dev/ic/ns16550reg.h>
125 #include <dev/ic/st16650reg.h>
126 #ifdef COM_HAYESP
127 #include <dev/ic/hayespreg.h>
128 #endif
129 #define	com_lcr	com_cfcr
130 #include <dev/cons.h>
131 
132 #ifdef	COM_REGMAP
133 #define	CSR_WRITE_1(r, o, v)	\
134 	bus_space_write_1((r)->cr_iot, (r)->cr_ioh, (r)->cr_map[o], v)
135 #define	CSR_READ_1(r, o)	\
136 	bus_space_read_1((r)->cr_iot, (r)->cr_ioh, (r)->cr_map[o])
137 #define	CSR_WRITE_2(r, o, v)	\
138 	bus_space_write_2((r)->cr_iot, (r)->cr_ioh, (r)->cr_map[o], v)
139 #define	CSR_READ_2(r, o)	\
140 	bus_space_read_2((r)->cr_iot, (r)->cr_ioh, (r)->cr_map[o])
141 #define	CSR_WRITE_MULTI(r, o, p, n)	\
142 	bus_space_write_multi_1((r)->cr_iot, (r)->cr_ioh, (r)->cr_map[o], p, n)
143 #else
144 #define	CSR_WRITE_1(r, o, v)	\
145 	bus_space_write_1((r)->cr_iot, (r)->cr_ioh, o, v)
146 #define	CSR_READ_1(r, o)	\
147 	bus_space_read_1((r)->cr_iot, (r)->cr_ioh, o)
148 #define	CSR_WRITE_2(r, o, v)	\
149 	bus_space_write_2((r)->cr_iot, (r)->cr_ioh, o, v)
150 #define	CSR_READ_2(r, o)	\
151 	bus_space_read_2((r)->cr_iot, (r)->cr_ioh, o)
152 #define	CSR_WRITE_MULTI(r, o, p, n)	\
153 	bus_space_write_multi_1((r)->cr_iot, (r)->cr_ioh, o, p, n)
154 #endif
155 
156 
157 static void com_enable_debugport(struct com_softc *);
158 
159 void	com_config(struct com_softc *);
160 void	com_shutdown(struct com_softc *);
161 int	comspeed(long, long, int);
162 static	u_char	cflag2lcr(tcflag_t);
163 int	comparam(struct tty *, struct termios *);
164 void	comstart(struct tty *);
165 int	comhwiflow(struct tty *, int);
166 
167 void	com_loadchannelregs(struct com_softc *);
168 void	com_hwiflow(struct com_softc *);
169 void	com_break(struct com_softc *, int);
170 void	com_modem(struct com_softc *, int);
171 void	tiocm_to_com(struct com_softc *, u_long, int);
172 int	com_to_tiocm(struct com_softc *);
173 void	com_iflush(struct com_softc *);
174 
175 int	com_common_getc(dev_t, struct com_regs *);
176 static void	com_common_putc(dev_t, struct com_regs *, int);
177 
178 int	cominit(struct com_regs *, int, int, int, tcflag_t);
179 
180 static int comcnreattach(void);
181 
182 int	comcngetc(dev_t);
183 void	comcnputc(dev_t, int);
184 void	comcnpollc(dev_t, int);
185 
186 #define	integrate	static inline
187 void	comsoft(void *);
188 integrate void com_rxsoft(struct com_softc *, struct tty *);
189 integrate void com_txsoft(struct com_softc *, struct tty *);
190 integrate void com_stsoft(struct com_softc *, struct tty *);
191 integrate void com_schedrx(struct com_softc *);
192 void	comdiag(void *);
193 
194 extern struct cfdriver com_cd;
195 
196 dev_type_open(comopen);
197 dev_type_close(comclose);
198 dev_type_read(comread);
199 dev_type_write(comwrite);
200 dev_type_ioctl(comioctl);
201 dev_type_stop(comstop);
202 dev_type_tty(comtty);
203 dev_type_poll(compoll);
204 
205 static struct comcons_info comcons_info;
206 
207 /*
208  * Following are all routines needed for COM to act as console
209  */
210 static struct consdev comcons = {
211 	NULL, NULL, comcngetc, comcnputc, comcnpollc, NULL, NULL, NULL,
212 	NODEV, CN_NORMAL
213 };
214 
215 
216 const struct cdevsw com_cdevsw = {
217 	comopen, comclose, comread, comwrite, comioctl,
218 	comstop, comtty, compoll, nommap, ttykqfilter, D_TTY
219 };
220 
221 /*
222  * Make this an option variable one can patch.
223  * But be warned:  this must be a power of 2!
224  */
225 u_int com_rbuf_size = COM_RING_SIZE;
226 
227 /* Stop input when 3/4 of the ring is full; restart when only 1/4 is full. */
228 u_int com_rbuf_hiwat = (COM_RING_SIZE * 1) / 4;
229 u_int com_rbuf_lowat = (COM_RING_SIZE * 3) / 4;
230 
231 static int comconsattached;
232 static struct cnm_state com_cnm_state;
233 
234 #ifdef KGDB
235 #include <sys/kgdb.h>
236 
237 static struct com_regs comkgdbregs;
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 #ifdef COM_REGMAP
245 /* initializer for typical 16550-ish hardware */
246 #define	COM_REG_16550	{ \
247 	com_data, com_data, com_dlbl, com_dlbh, com_ier, com_iir, com_fifo, \
248 	com_efr, com_lcr, com_mcr, com_lsr, com_msr }
249 /* 16750-specific register set, additional UART status register */
250 #define	COM_REG_16750	{ \
251 	com_data, com_data, com_dlbl, com_dlbh, com_ier, com_iir, com_fifo, \
252 	com_efr, com_lcr, com_mcr, com_lsr, com_msr, 0, 0, 0, 0, 0, 0, 0, 0, \
253 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, com_usr }
254 
255 #ifdef COM_16750
256 const bus_size_t com_std_map[32] = COM_REG_16750;
257 #else
258 const bus_size_t com_std_map[16] = COM_REG_16550;
259 #endif /* COM_16750 */
260 #endif /* COM_REGMAP */
261 
262 #define	COMUNIT_MASK	0x7ffff
263 #define	COMDIALOUT_MASK	0x80000
264 
265 #define	COMUNIT(x)	(minor(x) & COMUNIT_MASK)
266 #define	COMDIALOUT(x)	(minor(x) & COMDIALOUT_MASK)
267 
268 #define	COM_ISALIVE(sc)	((sc)->enabled != 0 && \
269 			 device_is_active((sc)->sc_dev))
270 
271 #define	BR	BUS_SPACE_BARRIER_READ
272 #define	BW	BUS_SPACE_BARRIER_WRITE
273 #define COM_BARRIER(r, f) \
274 	bus_space_barrier((r)->cr_iot, (r)->cr_ioh, 0, (r)->cr_nports, (f))
275 
276 /*ARGSUSED*/
277 int
278 comspeed(long speed, long frequency, int type)
279 {
280 #define	divrnd(n, q)	(((n)*2/(q)+1)/2)	/* divide and round off */
281 
282 	int x, err;
283 	int divisor = 16;
284 
285 	if ((type == COM_TYPE_OMAP) && (speed > 230400)) {
286 	    divisor = 13;
287 	}
288 
289 #if 0
290 	if (speed == 0)
291 		return (0);
292 #endif
293 	if (speed <= 0)
294 		return (-1);
295 	x = divrnd(frequency / divisor, speed);
296 	if (x <= 0)
297 		return (-1);
298 	err = divrnd(((quad_t)frequency) * 1000 / divisor, speed * x) - 1000;
299 	if (err < 0)
300 		err = -err;
301 	if (err > COM_TOLERANCE)
302 		return (-1);
303 	return (x);
304 
305 #undef	divrnd
306 }
307 
308 #ifdef COM_DEBUG
309 int	com_debug = 0;
310 
311 void comstatus(struct com_softc *, const char *);
312 void
313 comstatus(struct com_softc *sc, const char *str)
314 {
315 	struct tty *tp = sc->sc_tty;
316 
317 	aprint_normal_dev(sc->sc_dev,
318 	    "%s %cclocal  %cdcd %cts_carr_on %cdtr %ctx_stopped\n",
319 	    str,
320 	    ISSET(tp->t_cflag, CLOCAL) ? '+' : '-',
321 	    ISSET(sc->sc_msr, MSR_DCD) ? '+' : '-',
322 	    ISSET(tp->t_state, TS_CARR_ON) ? '+' : '-',
323 	    ISSET(sc->sc_mcr, MCR_DTR) ? '+' : '-',
324 	    sc->sc_tx_stopped ? '+' : '-');
325 
326 	aprint_normal_dev(sc->sc_dev,
327 	    "%s %ccrtscts %ccts %cts_ttstop  %crts rx_flags=0x%x\n",
328 	    str,
329 	    ISSET(tp->t_cflag, CRTSCTS) ? '+' : '-',
330 	    ISSET(sc->sc_msr, MSR_CTS) ? '+' : '-',
331 	    ISSET(tp->t_state, TS_TTSTOP) ? '+' : '-',
332 	    ISSET(sc->sc_mcr, MCR_RTS) ? '+' : '-',
333 	    sc->sc_rx_flags);
334 }
335 #endif
336 
337 int
338 com_probe_subr(struct com_regs *regs)
339 {
340 
341 	/* force access to id reg */
342 	CSR_WRITE_1(regs, COM_REG_LCR, LCR_8BITS);
343 	CSR_WRITE_1(regs, COM_REG_IIR, 0);
344 	if ((CSR_READ_1(regs, COM_REG_LCR) != LCR_8BITS) ||
345 	    (CSR_READ_1(regs, COM_REG_IIR) & 0x38))
346 		return (0);
347 
348 	return (1);
349 }
350 
351 int
352 comprobe1(bus_space_tag_t iot, bus_space_handle_t ioh)
353 {
354 	struct com_regs	regs;
355 
356 	regs.cr_iot = iot;
357 	regs.cr_ioh = ioh;
358 #ifdef	COM_REGMAP
359 	memcpy(regs.cr_map, com_std_map, sizeof (regs.cr_map));
360 #endif
361 
362 	return com_probe_subr(&regs);
363 }
364 
365 /*
366  * No locking in this routine; it is only called during attach,
367  * or with the port already locked.
368  */
369 static void
370 com_enable_debugport(struct com_softc *sc)
371 {
372 
373 	/* Turn on line break interrupt, set carrier. */
374 	sc->sc_ier = IER_ERXRDY;
375 	if (sc->sc_type == COM_TYPE_PXA2x0)
376 		sc->sc_ier |= IER_EUART | IER_ERXTOUT;
377 	CSR_WRITE_1(&sc->sc_regs, COM_REG_IER, sc->sc_ier);
378 	SET(sc->sc_mcr, MCR_DTR | MCR_RTS);
379 	CSR_WRITE_1(&sc->sc_regs, COM_REG_MCR, sc->sc_mcr);
380 }
381 
382 void
383 com_attach_subr(struct com_softc *sc)
384 {
385 	struct com_regs *regsp = &sc->sc_regs;
386 	struct tty *tp;
387 #ifdef COM_16650
388 	u_int8_t lcr;
389 #endif
390 	const char *fifo_msg = NULL;
391 	prop_dictionary_t	dict;
392 	bool is_console = true;
393 
394 	aprint_naive("\n");
395 
396 	dict = device_properties(sc->sc_dev);
397 	prop_dictionary_get_bool(dict, "is_console", &is_console);
398 
399 	callout_init(&sc->sc_diag_callout, 0);
400 	mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_HIGH);
401 
402 	/* Disable interrupts before configuring the device. */
403 	if (sc->sc_type == COM_TYPE_PXA2x0)
404 		sc->sc_ier = IER_EUART;
405 	else
406 		sc->sc_ier = 0;
407 
408 	CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
409 
410 	if (bus_space_is_equal(regsp->cr_iot, comcons_info.regs.cr_iot) &&
411 	    regsp->cr_iobase == comcons_info.regs.cr_iobase) {
412 		comconsattached = 1;
413 
414 		if (cn_tab == NULL && comcnreattach() != 0) {
415 			printf("can't re-init serial console @%lx\n",
416 			    (u_long)comcons_info.regs.cr_iobase);
417 		}
418 
419 #ifdef COM_16750
420 		/* Use in comintr(). */
421 		sc->sc_lcr = cflag2lcr(comcons_info.cflag);
422 #endif
423 
424 		/* Make sure the console is always "hardwired". */
425 		delay(10000);			/* wait for output to finish */
426 		if (is_console) {
427 			SET(sc->sc_hwflags, COM_HW_CONSOLE);
428 		}
429 
430 		SET(sc->sc_swflags, TIOCFLAG_SOFTCAR);
431 	}
432 
433 	/* Probe for FIFO */
434 	switch (sc->sc_type) {
435 	case COM_TYPE_HAYESP:
436 		goto fifodone;
437 
438 	case COM_TYPE_AU1x00:
439 		sc->sc_fifolen = 16;
440 		fifo_msg = "Au1X00 UART, working fifo";
441 		SET(sc->sc_hwflags, COM_HW_FIFO);
442 		goto fifodelay;
443 
444 	case COM_TYPE_16550_NOERS:
445 		sc->sc_fifolen = 16;
446 		fifo_msg = "ns16650, no ERS, working fifo";
447 		SET(sc->sc_hwflags, COM_HW_FIFO);
448 		goto fifodelay;
449 
450 	case COM_TYPE_OMAP:
451 		sc->sc_fifolen = 64;
452 		fifo_msg = "OMAP UART, working fifo";
453 		SET(sc->sc_hwflags, COM_HW_FIFO);
454 		goto fifodelay;
455 	}
456 
457 	sc->sc_fifolen = 1;
458 	/* look for a NS 16550AF UART with FIFOs */
459 	CSR_WRITE_1(regsp, COM_REG_FIFO,
460 	    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_14);
461 	delay(100);
462 	if (ISSET(CSR_READ_1(regsp, COM_REG_IIR), IIR_FIFO_MASK)
463 	    == IIR_FIFO_MASK)
464 		if (ISSET(CSR_READ_1(regsp, COM_REG_FIFO), FIFO_TRIGGER_14)
465 		    == FIFO_TRIGGER_14) {
466 			SET(sc->sc_hwflags, COM_HW_FIFO);
467 
468 #ifdef COM_16650
469 			/*
470 			 * IIR changes into the EFR if LCR is set to LCR_EERS
471 			 * on 16650s. We also know IIR != 0 at this point.
472 			 * Write 0 into the EFR, and read it. If the result
473 			 * is 0, we have a 16650.
474 			 *
475 			 * Older 16650s were broken; the test to detect them
476 			 * is taken from the Linux driver. Apparently
477 			 * setting DLAB enable gives access to the EFR on
478 			 * these chips.
479 			 */
480 			lcr = CSR_READ_1(regsp, COM_REG_LCR);
481 			CSR_WRITE_1(regsp, COM_REG_LCR, LCR_EERS);
482 			CSR_WRITE_1(regsp, COM_REG_EFR, 0);
483 			if (CSR_READ_1(regsp, COM_REG_EFR) == 0) {
484 				CSR_WRITE_1(regsp, COM_REG_LCR, lcr | LCR_DLAB);
485 				if (CSR_READ_1(regsp, COM_REG_EFR) == 0) {
486 					CLR(sc->sc_hwflags, COM_HW_FIFO);
487 					sc->sc_fifolen = 0;
488 				} else {
489 					SET(sc->sc_hwflags, COM_HW_FLOW);
490 					sc->sc_fifolen = 32;
491 				}
492 			} else
493 #endif
494 				sc->sc_fifolen = 16;
495 
496 #ifdef COM_16650
497 			CSR_WRITE_1(regsp, COM_REG_LCR, lcr);
498 			if (sc->sc_fifolen == 0)
499 				fifo_msg = "st16650, broken fifo";
500 			else if (sc->sc_fifolen == 32)
501 				fifo_msg = "st16650a, working fifo";
502 			else
503 #endif
504 				fifo_msg = "ns16550a, working fifo";
505 		} else
506 			fifo_msg = "ns16550, broken fifo";
507 	else
508 		fifo_msg = "ns8250 or ns16450, no fifo";
509 	CSR_WRITE_1(regsp, COM_REG_FIFO, 0);
510 fifodelay:
511 	/*
512 	 * Some chips will clear down both Tx and Rx FIFOs when zero is
513 	 * written to com_fifo. If this chip is the console, writing zero
514 	 * results in some of the chip/FIFO description being lost, so delay
515 	 * printing it until now.
516 	 */
517 	delay(10);
518 	aprint_normal(": %s\n", fifo_msg);
519 	if (ISSET(sc->sc_hwflags, COM_HW_TXFIFO_DISABLE)) {
520 		sc->sc_fifolen = 1;
521 		aprint_normal_dev(sc->sc_dev, "txfifo disabled\n");
522 	}
523 
524 fifodone:
525 
526 	tp = tty_alloc();
527 	tp->t_oproc = comstart;
528 	tp->t_param = comparam;
529 	tp->t_hwiflow = comhwiflow;
530 	tp->t_softc = sc;
531 
532 	sc->sc_tty = tp;
533 	sc->sc_rbuf = malloc(com_rbuf_size << 1, M_DEVBUF, M_NOWAIT);
534 	sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
535 	sc->sc_rbavail = com_rbuf_size;
536 	if (sc->sc_rbuf == NULL) {
537 		aprint_error_dev(sc->sc_dev,
538 		    "unable to allocate ring buffer\n");
539 		return;
540 	}
541 	sc->sc_ebuf = sc->sc_rbuf + (com_rbuf_size << 1);
542 
543 	tty_attach(tp);
544 
545 	if (!ISSET(sc->sc_hwflags, COM_HW_NOIEN))
546 		SET(sc->sc_mcr, MCR_IENABLE);
547 
548 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
549 		int maj;
550 
551 		/* locate the major number */
552 		maj = cdevsw_lookup_major(&com_cdevsw);
553 
554 		tp->t_dev = cn_tab->cn_dev = makedev(maj,
555 						     device_unit(sc->sc_dev));
556 
557 		aprint_normal_dev(sc->sc_dev, "console\n");
558 	}
559 
560 #ifdef KGDB
561 	/*
562 	 * Allow kgdb to "take over" this port.  If this is
563 	 * not the console and is the kgdb device, it has
564 	 * exclusive use.  If it's the console _and_ the
565 	 * kgdb device, it doesn't.
566 	 */
567 	if (bus_space_is_equal(regsp->cr_iot, comkgdbregs.cr_iot) &&
568 	    regsp->cr_iobase == comkgdbregs.cr_iobase) {
569 		if (!ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
570 			com_kgdb_attached = 1;
571 
572 			SET(sc->sc_hwflags, COM_HW_KGDB);
573 		}
574 		aprint_normal_dev(sc->sc_dev, "kgdb\n");
575 	}
576 #endif
577 
578 	sc->sc_si = softint_establish(SOFTINT_SERIAL, comsoft, sc);
579 
580 #ifdef RND_COM
581 	rnd_attach_source(&sc->rnd_source, device_xname(sc->sc_dev),
582 			  RND_TYPE_TTY, 0);
583 #endif
584 
585 	/* if there are no enable/disable functions, assume the device
586 	   is always enabled */
587 	if (!sc->enable)
588 		sc->enabled = 1;
589 
590 	com_config(sc);
591 
592 	SET(sc->sc_hwflags, COM_HW_DEV_OK);
593 }
594 
595 void
596 com_config(struct com_softc *sc)
597 {
598 	struct com_regs *regsp = &sc->sc_regs;
599 
600 	/* Disable interrupts before configuring the device. */
601 	if (sc->sc_type == COM_TYPE_PXA2x0)
602 		sc->sc_ier = IER_EUART;
603 	else
604 		sc->sc_ier = 0;
605 	CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
606 	(void) CSR_READ_1(regsp, COM_REG_IIR);
607 
608 #ifdef COM_HAYESP
609 	/* Look for a Hayes ESP board. */
610 	if (sc->sc_type == COM_TYPE_HAYESP) {
611 
612 		/* Set 16550 compatibility mode */
613 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD1,
614 				  HAYESP_SETMODE);
615 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
616 				  HAYESP_MODE_FIFO|HAYESP_MODE_RTS|
617 				  HAYESP_MODE_SCALE);
618 
619 		/* Set RTS/CTS flow control */
620 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD1,
621 				  HAYESP_SETFLOWTYPE);
622 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
623 				  HAYESP_FLOW_RTS);
624 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
625 				  HAYESP_FLOW_CTS);
626 
627 		/* Set flow control levels */
628 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD1,
629 				  HAYESP_SETRXFLOW);
630 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
631 				  HAYESP_HIBYTE(HAYESP_RXHIWMARK));
632 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
633 				  HAYESP_LOBYTE(HAYESP_RXHIWMARK));
634 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
635 				  HAYESP_HIBYTE(HAYESP_RXLOWMARK));
636 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
637 				  HAYESP_LOBYTE(HAYESP_RXLOWMARK));
638 	}
639 #endif
640 
641 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE|COM_HW_KGDB))
642 		com_enable_debugport(sc);
643 }
644 
645 #if 0
646 static int
647 comcngetc_detached(dev_t dev)
648 {
649 	return 0;
650 }
651 
652 static void
653 comcnputc_detached(dev_t dev, int c)
654 {
655 }
656 #endif
657 
658 int
659 com_detach(device_t self, int flags)
660 {
661 	struct com_softc *sc = device_private(self);
662 	int maj, mn;
663 
664 	if (ISSET(sc->sc_hwflags, COM_HW_KGDB))
665 		return EBUSY;
666 
667 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE) &&
668 	    (flags & DETACH_SHUTDOWN) != 0)
669 		return EBUSY;
670 
671 	if (sc->disable != NULL && sc->enabled != 0) {
672 		(*sc->disable)(sc);
673 		sc->enabled = 0;
674 	}
675 
676 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
677 		comconsattached = 0;
678 		cn_tab = NULL;
679 	}
680 
681 	/* locate the major number */
682 	maj = cdevsw_lookup_major(&com_cdevsw);
683 
684 	/* Nuke the vnodes for any open instances. */
685 	mn = device_unit(self);
686 	vdevgone(maj, mn, mn, VCHR);
687 
688 	mn |= COMDIALOUT_MASK;
689 	vdevgone(maj, mn, mn, VCHR);
690 
691 	if (sc->sc_rbuf == NULL) {
692 		/*
693 		 * Ring buffer allocation failed in the com_attach_subr,
694 		 * only the tty is allocated, and nothing else.
695 		 */
696 		tty_free(sc->sc_tty);
697 		return 0;
698 	}
699 
700 	/* Free the receive buffer. */
701 	free(sc->sc_rbuf, M_DEVBUF);
702 
703 	/* Detach and free the tty. */
704 	tty_detach(sc->sc_tty);
705 	tty_free(sc->sc_tty);
706 
707 	/* Unhook the soft interrupt handler. */
708 	softint_disestablish(sc->sc_si);
709 
710 #ifdef RND_COM
711 	/* Unhook the entropy source. */
712 	rnd_detach_source(&sc->rnd_source);
713 #endif
714 	callout_destroy(&sc->sc_diag_callout);
715 
716 	/* Destroy the lock. */
717 	mutex_destroy(&sc->sc_lock);
718 
719 	return (0);
720 }
721 
722 void
723 com_shutdown(struct com_softc *sc)
724 {
725 	struct tty *tp = sc->sc_tty;
726 
727 	mutex_spin_enter(&sc->sc_lock);
728 
729 	/* If we were asserting flow control, then deassert it. */
730 	SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
731 	com_hwiflow(sc);
732 
733 	/* Clear any break condition set with TIOCSBRK. */
734 	com_break(sc, 0);
735 
736 	/*
737 	 * Hang up if necessary.  Wait a bit, so the other side has time to
738 	 * notice even if we immediately open the port again.
739 	 * Avoid tsleeping above splhigh().
740 	 */
741 	if (ISSET(tp->t_cflag, HUPCL)) {
742 		com_modem(sc, 0);
743 		mutex_spin_exit(&sc->sc_lock);
744 		/* XXX will only timeout */
745 		(void) kpause(ttclos, false, hz, NULL);
746 		mutex_spin_enter(&sc->sc_lock);
747 	}
748 
749 	/* Turn off interrupts. */
750 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
751 		sc->sc_ier = IER_ERXRDY; /* interrupt on break */
752 		if (sc->sc_type == COM_TYPE_PXA2x0)
753 			sc->sc_ier |= IER_ERXTOUT;
754 	} else
755 		sc->sc_ier = 0;
756 
757 	if (sc->sc_type == COM_TYPE_PXA2x0)
758 		sc->sc_ier |= IER_EUART;
759 
760 	CSR_WRITE_1(&sc->sc_regs, COM_REG_IER, sc->sc_ier);
761 
762 	mutex_spin_exit(&sc->sc_lock);
763 
764 	if (sc->disable) {
765 #ifdef DIAGNOSTIC
766 		if (!sc->enabled)
767 			panic("com_shutdown: not enabled?");
768 #endif
769 		(*sc->disable)(sc);
770 		sc->enabled = 0;
771 	}
772 }
773 
774 int
775 comopen(dev_t dev, int flag, int mode, struct lwp *l)
776 {
777 	struct com_softc *sc;
778 	struct tty *tp;
779 	int s;
780 	int error;
781 
782 	sc = device_lookup_private(&com_cd, COMUNIT(dev));
783 	if (sc == NULL || !ISSET(sc->sc_hwflags, COM_HW_DEV_OK) ||
784 		sc->sc_rbuf == NULL)
785 		return (ENXIO);
786 
787 	if (!device_is_active(sc->sc_dev))
788 		return (ENXIO);
789 
790 #ifdef KGDB
791 	/*
792 	 * If this is the kgdb port, no other use is permitted.
793 	 */
794 	if (ISSET(sc->sc_hwflags, COM_HW_KGDB))
795 		return (EBUSY);
796 #endif
797 
798 	tp = sc->sc_tty;
799 
800 	if (kauth_authorize_device_tty(l->l_cred, KAUTH_DEVICE_TTY_OPEN, tp))
801 		return (EBUSY);
802 
803 	s = spltty();
804 
805 	/*
806 	 * Do the following iff this is a first open.
807 	 */
808 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
809 		struct termios t;
810 
811 		tp->t_dev = dev;
812 
813 		if (sc->enable) {
814 			if ((*sc->enable)(sc)) {
815 				splx(s);
816 				aprint_error_dev(sc->sc_dev,
817 				    "device enable failed\n");
818 				return (EIO);
819 			}
820 			mutex_spin_enter(&sc->sc_lock);
821 			sc->enabled = 1;
822 			com_config(sc);
823 		} else {
824 			mutex_spin_enter(&sc->sc_lock);
825 		}
826 
827 		/* Turn on interrupts. */
828 		sc->sc_ier = IER_ERXRDY | IER_ERLS;
829 		if (!ISSET(tp->t_cflag, CLOCAL))
830 			sc->sc_ier |= IER_EMSC;
831 
832 		if (sc->sc_type == COM_TYPE_PXA2x0)
833 			sc->sc_ier |= IER_EUART | IER_ERXTOUT;
834 		CSR_WRITE_1(&sc->sc_regs, COM_REG_IER, sc->sc_ier);
835 
836 		/* Fetch the current modem control status, needed later. */
837 		sc->sc_msr = CSR_READ_1(&sc->sc_regs, COM_REG_MSR);
838 
839 		/* Clear PPS capture state on first open. */
840 		mutex_spin_enter(&timecounter_lock);
841 		memset(&sc->sc_pps_state, 0, sizeof(sc->sc_pps_state));
842 		sc->sc_pps_state.ppscap = PPS_CAPTUREASSERT | PPS_CAPTURECLEAR;
843 		pps_init(&sc->sc_pps_state);
844 		mutex_spin_exit(&timecounter_lock);
845 
846 		mutex_spin_exit(&sc->sc_lock);
847 
848 		/*
849 		 * Initialize the termios status to the defaults.  Add in the
850 		 * sticky bits from TIOCSFLAGS.
851 		 */
852 		if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
853 			t.c_ospeed = comcons_info.rate;
854 			t.c_cflag = comcons_info.cflag;
855 		} else {
856 			t.c_ospeed = TTYDEF_SPEED;
857 			t.c_cflag = TTYDEF_CFLAG;
858 		}
859 		t.c_ispeed = t.c_ospeed;
860 		if (ISSET(sc->sc_swflags, TIOCFLAG_CLOCAL))
861 			SET(t.c_cflag, CLOCAL);
862 		if (ISSET(sc->sc_swflags, TIOCFLAG_CRTSCTS))
863 			SET(t.c_cflag, CRTSCTS);
864 		if (ISSET(sc->sc_swflags, TIOCFLAG_MDMBUF))
865 			SET(t.c_cflag, MDMBUF);
866 		/* Make sure comparam() will do something. */
867 		tp->t_ospeed = 0;
868 		(void) comparam(tp, &t);
869 		tp->t_iflag = TTYDEF_IFLAG;
870 		tp->t_oflag = TTYDEF_OFLAG;
871 		tp->t_lflag = TTYDEF_LFLAG;
872 		ttychars(tp);
873 		ttsetwater(tp);
874 
875 		mutex_spin_enter(&sc->sc_lock);
876 
877 		/*
878 		 * Turn on DTR.  We must always do this, even if carrier is not
879 		 * present, because otherwise we'd have to use TIOCSDTR
880 		 * immediately after setting CLOCAL, which applications do not
881 		 * expect.  We always assert DTR while the device is open
882 		 * unless explicitly requested to deassert it.
883 		 */
884 		com_modem(sc, 1);
885 
886 		/* Clear the input ring, and unblock. */
887 		sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
888 		sc->sc_rbavail = com_rbuf_size;
889 		com_iflush(sc);
890 		CLR(sc->sc_rx_flags, RX_ANY_BLOCK);
891 		com_hwiflow(sc);
892 
893 #ifdef COM_DEBUG
894 		if (com_debug)
895 			comstatus(sc, "comopen  ");
896 #endif
897 
898 		mutex_spin_exit(&sc->sc_lock);
899 	}
900 
901 	splx(s);
902 
903 	error = ttyopen(tp, COMDIALOUT(dev), ISSET(flag, O_NONBLOCK));
904 	if (error)
905 		goto bad;
906 
907 	error = (*tp->t_linesw->l_open)(dev, tp);
908 	if (error)
909 		goto bad;
910 
911 	return (0);
912 
913 bad:
914 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
915 		/*
916 		 * We failed to open the device, and nobody else had it opened.
917 		 * Clean up the state as appropriate.
918 		 */
919 		com_shutdown(sc);
920 	}
921 
922 	return (error);
923 }
924 
925 int
926 comclose(dev_t dev, int flag, int mode, struct lwp *l)
927 {
928 	struct com_softc *sc =
929 	    device_lookup_private(&com_cd, COMUNIT(dev));
930 	struct tty *tp = sc->sc_tty;
931 
932 	/* XXX This is for cons.c. */
933 	if (!ISSET(tp->t_state, TS_ISOPEN))
934 		return (0);
935 
936 	(*tp->t_linesw->l_close)(tp, flag);
937 	ttyclose(tp);
938 
939 	if (COM_ISALIVE(sc) == 0)
940 		return (0);
941 
942 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
943 		/*
944 		 * Although we got a last close, the device may still be in
945 		 * use; e.g. if this was the dialout node, and there are still
946 		 * processes waiting for carrier on the non-dialout node.
947 		 */
948 		com_shutdown(sc);
949 	}
950 
951 	return (0);
952 }
953 
954 int
955 comread(dev_t dev, struct uio *uio, int flag)
956 {
957 	struct com_softc *sc =
958 	    device_lookup_private(&com_cd, COMUNIT(dev));
959 	struct tty *tp = sc->sc_tty;
960 
961 	if (COM_ISALIVE(sc) == 0)
962 		return (EIO);
963 
964 	return ((*tp->t_linesw->l_read)(tp, uio, flag));
965 }
966 
967 int
968 comwrite(dev_t dev, struct uio *uio, int flag)
969 {
970 	struct com_softc *sc =
971 	    device_lookup_private(&com_cd, COMUNIT(dev));
972 	struct tty *tp = sc->sc_tty;
973 
974 	if (COM_ISALIVE(sc) == 0)
975 		return (EIO);
976 
977 	return ((*tp->t_linesw->l_write)(tp, uio, flag));
978 }
979 
980 int
981 compoll(dev_t dev, int events, struct lwp *l)
982 {
983 	struct com_softc *sc =
984 	    device_lookup_private(&com_cd, COMUNIT(dev));
985 	struct tty *tp = sc->sc_tty;
986 
987 	if (COM_ISALIVE(sc) == 0)
988 		return (POLLHUP);
989 
990 	return ((*tp->t_linesw->l_poll)(tp, events, l));
991 }
992 
993 struct tty *
994 comtty(dev_t dev)
995 {
996 	struct com_softc *sc =
997 	    device_lookup_private(&com_cd, COMUNIT(dev));
998 	struct tty *tp = sc->sc_tty;
999 
1000 	return (tp);
1001 }
1002 
1003 int
1004 comioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
1005 {
1006 	struct com_softc *sc;
1007 	struct tty *tp;
1008 	int error;
1009 
1010 	sc = device_lookup_private(&com_cd, COMUNIT(dev));
1011 	if (sc == NULL)
1012 		return ENXIO;
1013 	if (COM_ISALIVE(sc) == 0)
1014 		return (EIO);
1015 
1016 	tp = sc->sc_tty;
1017 
1018 	error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, l);
1019 	if (error != EPASSTHROUGH)
1020 		return (error);
1021 
1022 	error = ttioctl(tp, cmd, data, flag, l);
1023 	if (error != EPASSTHROUGH)
1024 		return (error);
1025 
1026 	error = 0;
1027 	switch (cmd) {
1028 	case TIOCSFLAGS:
1029 		error = kauth_authorize_device_tty(l->l_cred,
1030 		    KAUTH_DEVICE_TTY_PRIVSET, tp);
1031 		break;
1032 	default:
1033 		/* nothing */
1034 		break;
1035 	}
1036 	if (error) {
1037 		return error;
1038 	}
1039 
1040 	mutex_spin_enter(&sc->sc_lock);
1041 
1042 	switch (cmd) {
1043 	case TIOCSBRK:
1044 		com_break(sc, 1);
1045 		break;
1046 
1047 	case TIOCCBRK:
1048 		com_break(sc, 0);
1049 		break;
1050 
1051 	case TIOCSDTR:
1052 		com_modem(sc, 1);
1053 		break;
1054 
1055 	case TIOCCDTR:
1056 		com_modem(sc, 0);
1057 		break;
1058 
1059 	case TIOCGFLAGS:
1060 		*(int *)data = sc->sc_swflags;
1061 		break;
1062 
1063 	case TIOCSFLAGS:
1064 		sc->sc_swflags = *(int *)data;
1065 		break;
1066 
1067 	case TIOCMSET:
1068 	case TIOCMBIS:
1069 	case TIOCMBIC:
1070 		tiocm_to_com(sc, cmd, *(int *)data);
1071 		break;
1072 
1073 	case TIOCMGET:
1074 		*(int *)data = com_to_tiocm(sc);
1075 		break;
1076 
1077 	case PPS_IOC_CREATE:
1078 	case PPS_IOC_DESTROY:
1079 	case PPS_IOC_GETPARAMS:
1080 	case PPS_IOC_SETPARAMS:
1081 	case PPS_IOC_GETCAP:
1082 	case PPS_IOC_FETCH:
1083 #ifdef PPS_SYNC
1084 	case PPS_IOC_KCBIND:
1085 #endif
1086 		mutex_spin_enter(&timecounter_lock);
1087 		error = pps_ioctl(cmd, data, &sc->sc_pps_state);
1088 		mutex_spin_exit(&timecounter_lock);
1089 		break;
1090 
1091 	case TIOCDCDTIMESTAMP:	/* XXX old, overloaded  API used by xntpd v3 */
1092 		mutex_spin_enter(&timecounter_lock);
1093 #ifndef PPS_TRAILING_EDGE
1094 		TIMESPEC_TO_TIMEVAL((struct timeval *)data,
1095 		    &sc->sc_pps_state.ppsinfo.assert_timestamp);
1096 #else
1097 		TIMESPEC_TO_TIMEVAL((struct timeval *)data,
1098 		    &sc->sc_pps_state.ppsinfo.clear_timestamp);
1099 #endif
1100 		mutex_spin_exit(&timecounter_lock);
1101 		break;
1102 
1103 	default:
1104 		error = EPASSTHROUGH;
1105 		break;
1106 	}
1107 
1108 	mutex_spin_exit(&sc->sc_lock);
1109 
1110 #ifdef COM_DEBUG
1111 	if (com_debug)
1112 		comstatus(sc, "comioctl ");
1113 #endif
1114 
1115 	return (error);
1116 }
1117 
1118 integrate void
1119 com_schedrx(struct com_softc *sc)
1120 {
1121 
1122 	sc->sc_rx_ready = 1;
1123 
1124 	/* Wake up the poller. */
1125 	softint_schedule(sc->sc_si);
1126 }
1127 
1128 void
1129 com_break(struct com_softc *sc, int onoff)
1130 {
1131 
1132 	if (onoff)
1133 		SET(sc->sc_lcr, LCR_SBREAK);
1134 	else
1135 		CLR(sc->sc_lcr, LCR_SBREAK);
1136 
1137 	if (!sc->sc_heldchange) {
1138 		if (sc->sc_tx_busy) {
1139 			sc->sc_heldtbc = sc->sc_tbc;
1140 			sc->sc_tbc = 0;
1141 			sc->sc_heldchange = 1;
1142 		} else
1143 			com_loadchannelregs(sc);
1144 	}
1145 }
1146 
1147 void
1148 com_modem(struct com_softc *sc, int onoff)
1149 {
1150 
1151 	if (sc->sc_mcr_dtr == 0)
1152 		return;
1153 
1154 	if (onoff)
1155 		SET(sc->sc_mcr, sc->sc_mcr_dtr);
1156 	else
1157 		CLR(sc->sc_mcr, sc->sc_mcr_dtr);
1158 
1159 	if (!sc->sc_heldchange) {
1160 		if (sc->sc_tx_busy) {
1161 			sc->sc_heldtbc = sc->sc_tbc;
1162 			sc->sc_tbc = 0;
1163 			sc->sc_heldchange = 1;
1164 		} else
1165 			com_loadchannelregs(sc);
1166 	}
1167 }
1168 
1169 void
1170 tiocm_to_com(struct com_softc *sc, u_long how, int ttybits)
1171 {
1172 	u_char combits;
1173 
1174 	combits = 0;
1175 	if (ISSET(ttybits, TIOCM_DTR))
1176 		SET(combits, MCR_DTR);
1177 	if (ISSET(ttybits, TIOCM_RTS))
1178 		SET(combits, MCR_RTS);
1179 
1180 	switch (how) {
1181 	case TIOCMBIC:
1182 		CLR(sc->sc_mcr, combits);
1183 		break;
1184 
1185 	case TIOCMBIS:
1186 		SET(sc->sc_mcr, combits);
1187 		break;
1188 
1189 	case TIOCMSET:
1190 		CLR(sc->sc_mcr, MCR_DTR | MCR_RTS);
1191 		SET(sc->sc_mcr, combits);
1192 		break;
1193 	}
1194 
1195 	if (!sc->sc_heldchange) {
1196 		if (sc->sc_tx_busy) {
1197 			sc->sc_heldtbc = sc->sc_tbc;
1198 			sc->sc_tbc = 0;
1199 			sc->sc_heldchange = 1;
1200 		} else
1201 			com_loadchannelregs(sc);
1202 	}
1203 }
1204 
1205 int
1206 com_to_tiocm(struct com_softc *sc)
1207 {
1208 	u_char combits;
1209 	int ttybits = 0;
1210 
1211 	combits = sc->sc_mcr;
1212 	if (ISSET(combits, MCR_DTR))
1213 		SET(ttybits, TIOCM_DTR);
1214 	if (ISSET(combits, MCR_RTS))
1215 		SET(ttybits, TIOCM_RTS);
1216 
1217 	combits = sc->sc_msr;
1218 	if (ISSET(combits, MSR_DCD))
1219 		SET(ttybits, TIOCM_CD);
1220 	if (ISSET(combits, MSR_CTS))
1221 		SET(ttybits, TIOCM_CTS);
1222 	if (ISSET(combits, MSR_DSR))
1223 		SET(ttybits, TIOCM_DSR);
1224 	if (ISSET(combits, MSR_RI | MSR_TERI))
1225 		SET(ttybits, TIOCM_RI);
1226 
1227 	if (ISSET(sc->sc_ier, IER_ERXRDY | IER_ETXRDY | IER_ERLS | IER_EMSC))
1228 		SET(ttybits, TIOCM_LE);
1229 
1230 	return (ttybits);
1231 }
1232 
1233 static u_char
1234 cflag2lcr(tcflag_t cflag)
1235 {
1236 	u_char lcr = 0;
1237 
1238 	switch (ISSET(cflag, CSIZE)) {
1239 	case CS5:
1240 		SET(lcr, LCR_5BITS);
1241 		break;
1242 	case CS6:
1243 		SET(lcr, LCR_6BITS);
1244 		break;
1245 	case CS7:
1246 		SET(lcr, LCR_7BITS);
1247 		break;
1248 	case CS8:
1249 		SET(lcr, LCR_8BITS);
1250 		break;
1251 	}
1252 	if (ISSET(cflag, PARENB)) {
1253 		SET(lcr, LCR_PENAB);
1254 		if (!ISSET(cflag, PARODD))
1255 			SET(lcr, LCR_PEVEN);
1256 	}
1257 	if (ISSET(cflag, CSTOPB))
1258 		SET(lcr, LCR_STOPB);
1259 
1260 	return (lcr);
1261 }
1262 
1263 int
1264 comparam(struct tty *tp, struct termios *t)
1265 {
1266 	struct com_softc *sc =
1267 	    device_lookup_private(&com_cd, COMUNIT(tp->t_dev));
1268 	int ospeed;
1269 	u_char lcr;
1270 
1271 	if (COM_ISALIVE(sc) == 0)
1272 		return (EIO);
1273 
1274 #ifdef COM_HAYESP
1275 	if (sc->sc_type == COM_TYPE_HAYESP) {
1276 		int prescaler, speed;
1277 
1278 		/*
1279 		 * Calculate UART clock prescaler.  It should be in
1280 		 * range of 0 .. 3.
1281 		 */
1282 		for (prescaler = 0, speed = t->c_ospeed; prescaler < 4;
1283 		    prescaler++, speed /= 2)
1284 			if ((ospeed = comspeed(speed, sc->sc_frequency,
1285 					       sc->sc_type)) > 0)
1286 				break;
1287 
1288 		if (prescaler == 4)
1289 			return (EINVAL);
1290 		sc->sc_prescaler = prescaler;
1291 	} else
1292 #endif
1293 	ospeed = comspeed(t->c_ospeed, sc->sc_frequency, sc->sc_type);
1294 
1295 	/* Check requested parameters. */
1296 	if (ospeed < 0)
1297 		return (EINVAL);
1298 	if (t->c_ispeed && t->c_ispeed != t->c_ospeed)
1299 		return (EINVAL);
1300 
1301 	/*
1302 	 * For the console, always force CLOCAL and !HUPCL, so that the port
1303 	 * is always active.
1304 	 */
1305 	if (ISSET(sc->sc_swflags, TIOCFLAG_SOFTCAR) ||
1306 	    ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
1307 		SET(t->c_cflag, CLOCAL);
1308 		CLR(t->c_cflag, HUPCL);
1309 	}
1310 
1311 	/*
1312 	 * If there were no changes, don't do anything.  This avoids dropping
1313 	 * input and improves performance when all we did was frob things like
1314 	 * VMIN and VTIME.
1315 	 */
1316 	if (tp->t_ospeed == t->c_ospeed &&
1317 	    tp->t_cflag == t->c_cflag)
1318 		return (0);
1319 
1320 	lcr = ISSET(sc->sc_lcr, LCR_SBREAK) | cflag2lcr(t->c_cflag);
1321 
1322 	mutex_spin_enter(&sc->sc_lock);
1323 
1324 	sc->sc_lcr = lcr;
1325 
1326 	/*
1327 	 * If we're not in a mode that assumes a connection is present, then
1328 	 * ignore carrier changes.
1329 	 */
1330 	if (ISSET(t->c_cflag, CLOCAL | MDMBUF))
1331 		sc->sc_msr_dcd = 0;
1332 	else
1333 		sc->sc_msr_dcd = MSR_DCD;
1334 	/*
1335 	 * Set the flow control pins depending on the current flow control
1336 	 * mode.
1337 	 */
1338 	if (ISSET(t->c_cflag, CRTSCTS)) {
1339 		sc->sc_mcr_dtr = MCR_DTR;
1340 		sc->sc_mcr_rts = MCR_RTS;
1341 		sc->sc_msr_cts = MSR_CTS;
1342 		sc->sc_efr = EFR_AUTORTS | EFR_AUTOCTS;
1343 	} else if (ISSET(t->c_cflag, MDMBUF)) {
1344 		/*
1345 		 * For DTR/DCD flow control, make sure we don't toggle DTR for
1346 		 * carrier detection.
1347 		 */
1348 		sc->sc_mcr_dtr = 0;
1349 		sc->sc_mcr_rts = MCR_DTR;
1350 		sc->sc_msr_cts = MSR_DCD;
1351 		sc->sc_efr = 0;
1352 	} else {
1353 		/*
1354 		 * If no flow control, then always set RTS.  This will make
1355 		 * the other side happy if it mistakenly thinks we're doing
1356 		 * RTS/CTS flow control.
1357 		 */
1358 		sc->sc_mcr_dtr = MCR_DTR | MCR_RTS;
1359 		sc->sc_mcr_rts = 0;
1360 		sc->sc_msr_cts = 0;
1361 		sc->sc_efr = 0;
1362 		if (ISSET(sc->sc_mcr, MCR_DTR))
1363 			SET(sc->sc_mcr, MCR_RTS);
1364 		else
1365 			CLR(sc->sc_mcr, MCR_RTS);
1366 	}
1367 	sc->sc_msr_mask = sc->sc_msr_cts | sc->sc_msr_dcd;
1368 
1369 #if 0
1370 	if (ospeed == 0)
1371 		CLR(sc->sc_mcr, sc->sc_mcr_dtr);
1372 	else
1373 		SET(sc->sc_mcr, sc->sc_mcr_dtr);
1374 #endif
1375 
1376 	sc->sc_dlbl = ospeed;
1377 	sc->sc_dlbh = ospeed >> 8;
1378 
1379 	/*
1380 	 * Set the FIFO threshold based on the receive speed.
1381 	 *
1382 	 *  * If it's a low speed, it's probably a mouse or some other
1383 	 *    interactive device, so set the threshold low.
1384 	 *  * If it's a high speed, trim the trigger level down to prevent
1385 	 *    overflows.
1386 	 *  * Otherwise set it a bit higher.
1387 	 */
1388 	if (sc->sc_type == COM_TYPE_HAYESP)
1389 		sc->sc_fifo = FIFO_DMA_MODE | FIFO_ENABLE | FIFO_TRIGGER_8;
1390 	else if (ISSET(sc->sc_hwflags, COM_HW_FIFO)) {
1391 		if (t->c_ospeed <= 1200)
1392 			sc->sc_fifo = FIFO_ENABLE | FIFO_TRIGGER_1;
1393 		else if (t->c_ospeed <= 38400)
1394 			sc->sc_fifo = FIFO_ENABLE | FIFO_TRIGGER_8;
1395 		else
1396 			sc->sc_fifo = FIFO_ENABLE | FIFO_TRIGGER_4;
1397 	} else
1398 		sc->sc_fifo = 0;
1399 
1400 	/* And copy to tty. */
1401 	tp->t_ispeed = t->c_ospeed;
1402 	tp->t_ospeed = t->c_ospeed;
1403 	tp->t_cflag = t->c_cflag;
1404 
1405 	if (!sc->sc_heldchange) {
1406 		if (sc->sc_tx_busy) {
1407 			sc->sc_heldtbc = sc->sc_tbc;
1408 			sc->sc_tbc = 0;
1409 			sc->sc_heldchange = 1;
1410 		} else
1411 			com_loadchannelregs(sc);
1412 	}
1413 
1414 	if (!ISSET(t->c_cflag, CHWFLOW)) {
1415 		/* Disable the high water mark. */
1416 		sc->sc_r_hiwat = 0;
1417 		sc->sc_r_lowat = 0;
1418 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
1419 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1420 			com_schedrx(sc);
1421 		}
1422 		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED)) {
1423 			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED);
1424 			com_hwiflow(sc);
1425 		}
1426 	} else {
1427 		sc->sc_r_hiwat = com_rbuf_hiwat;
1428 		sc->sc_r_lowat = com_rbuf_lowat;
1429 	}
1430 
1431 	mutex_spin_exit(&sc->sc_lock);
1432 
1433 	/*
1434 	 * Update the tty layer's idea of the carrier bit, in case we changed
1435 	 * CLOCAL or MDMBUF.  We don't hang up here; we only do that by
1436 	 * explicit request.
1437 	 */
1438 	(void) (*tp->t_linesw->l_modem)(tp, ISSET(sc->sc_msr, MSR_DCD));
1439 
1440 #ifdef COM_DEBUG
1441 	if (com_debug)
1442 		comstatus(sc, "comparam ");
1443 #endif
1444 
1445 	if (!ISSET(t->c_cflag, CHWFLOW)) {
1446 		if (sc->sc_tx_stopped) {
1447 			sc->sc_tx_stopped = 0;
1448 			comstart(tp);
1449 		}
1450 	}
1451 
1452 	return (0);
1453 }
1454 
1455 void
1456 com_iflush(struct com_softc *sc)
1457 {
1458 	struct com_regs	*regsp = &sc->sc_regs;
1459 #ifdef DIAGNOSTIC
1460 	int reg;
1461 #endif
1462 	int timo;
1463 
1464 #ifdef DIAGNOSTIC
1465 	reg = 0xffff;
1466 #endif
1467 	timo = 50000;
1468 	/* flush any pending I/O */
1469 	while (ISSET(CSR_READ_1(regsp, COM_REG_LSR), LSR_RXRDY)
1470 	    && --timo)
1471 #ifdef DIAGNOSTIC
1472 		reg =
1473 #else
1474 		    (void)
1475 #endif
1476 		    CSR_READ_1(regsp, COM_REG_RXDATA);
1477 #ifdef DIAGNOSTIC
1478 	if (!timo)
1479 		aprint_error_dev(sc->sc_dev, "com_iflush timeout %02x\n", reg);
1480 #endif
1481 
1482 #ifdef COM_16750
1483 	uint8_t fifo;
1484 	/*
1485 	 * Reset all Rx/Tx FIFO, preserve current FIFO length.
1486 	 * This should prevent triggering busy interrupt while
1487 	 * manipulating divisors.
1488 	 */
1489 	fifo = CSR_READ_1(regsp, COM_REG_FIFO) & (FIFO_TRIGGER_1 |
1490 	    FIFO_TRIGGER_4 | FIFO_TRIGGER_8 | FIFO_TRIGGER_14);
1491 	CSR_WRITE_1(regsp, COM_REG_FIFO, fifo | FIFO_ENABLE | FIFO_RCV_RST |
1492 	    FIFO_XMT_RST);
1493 	delay(100);
1494 #endif
1495 }
1496 
1497 void
1498 com_loadchannelregs(struct com_softc *sc)
1499 {
1500 	struct com_regs *regsp = &sc->sc_regs;
1501 
1502 	/* XXXXX necessary? */
1503 	com_iflush(sc);
1504 
1505 	if (sc->sc_type == COM_TYPE_PXA2x0)
1506 		CSR_WRITE_1(regsp, COM_REG_IER, IER_EUART);
1507 	else
1508 		CSR_WRITE_1(regsp, COM_REG_IER, 0);
1509 
1510 	if (sc->sc_type == COM_TYPE_OMAP) {
1511 		/* disable before changing settings */
1512 		CSR_WRITE_1(regsp, COM_REG_MDR1, MDR1_MODE_DISABLE);
1513 	}
1514 
1515 	if (ISSET(sc->sc_hwflags, COM_HW_FLOW)) {
1516 		KASSERT(sc->sc_type != COM_TYPE_AU1x00);
1517 		KASSERT(sc->sc_type != COM_TYPE_16550_NOERS);
1518 		/* no EFR on alchemy */
1519 		CSR_WRITE_1(regsp, COM_REG_LCR, LCR_EERS);
1520 		CSR_WRITE_1(regsp, COM_REG_EFR, sc->sc_efr);
1521 	}
1522 	if (sc->sc_type == COM_TYPE_AU1x00) {
1523 		/* alchemy has single separate 16-bit clock divisor register */
1524 		CSR_WRITE_2(regsp, COM_REG_DLBL, sc->sc_dlbl +
1525 		    (sc->sc_dlbh << 8));
1526 	} else {
1527 		CSR_WRITE_1(regsp, COM_REG_LCR, sc->sc_lcr | LCR_DLAB);
1528 		CSR_WRITE_1(regsp, COM_REG_DLBL, sc->sc_dlbl);
1529 		CSR_WRITE_1(regsp, COM_REG_DLBH, sc->sc_dlbh);
1530 	}
1531 	CSR_WRITE_1(regsp, COM_REG_LCR, sc->sc_lcr);
1532 	CSR_WRITE_1(regsp, COM_REG_MCR, sc->sc_mcr_active = sc->sc_mcr);
1533 	CSR_WRITE_1(regsp, COM_REG_FIFO, sc->sc_fifo);
1534 #ifdef COM_HAYESP
1535 	if (sc->sc_type == COM_TYPE_HAYESP) {
1536 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD1,
1537 		    HAYESP_SETPRESCALER);
1538 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
1539 		    sc->sc_prescaler);
1540 	}
1541 #endif
1542 	if (sc->sc_type == COM_TYPE_OMAP) {
1543 		/* setup the fifos.  the FCR value is not used as long
1544 		   as SCR[6] and SCR[7] are 0, which they are at reset
1545 		   and we never touch the SCR register */
1546 		uint8_t rx_fifo_trig = 40;
1547 		uint8_t tx_fifo_trig = 60;
1548 		uint8_t rx_start = 8;
1549 		uint8_t rx_halt = 60;
1550 		uint8_t tlr_value = ((rx_fifo_trig>>2) << 4) | (tx_fifo_trig>>2);
1551 		uint8_t tcr_value = ((rx_start>>2) << 4) | (rx_halt>>2);
1552 
1553 		/* enable access to TCR & TLR */
1554 		CSR_WRITE_1(regsp, COM_REG_MCR, sc->sc_mcr | MCR_TCR_TLR);
1555 
1556 		/* write tcr and tlr values */
1557 		CSR_WRITE_1(regsp, COM_REG_TLR, tlr_value);
1558 		CSR_WRITE_1(regsp, COM_REG_TCR, tcr_value);
1559 
1560 		/* disable access to TCR & TLR */
1561 		CSR_WRITE_1(regsp, COM_REG_MCR, sc->sc_mcr);
1562 
1563 		/* enable again, but mode is based on speed */
1564 		if (sc->sc_tty->t_termios.c_ospeed > 230400) {
1565 			CSR_WRITE_1(regsp, COM_REG_MDR1, MDR1_MODE_UART_13X);
1566 		} else {
1567 			CSR_WRITE_1(regsp, COM_REG_MDR1, MDR1_MODE_UART_16X);
1568 		}
1569 	}
1570 
1571 	CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
1572 }
1573 
1574 int
1575 comhwiflow(struct tty *tp, int block)
1576 {
1577 	struct com_softc *sc =
1578 	    device_lookup_private(&com_cd, COMUNIT(tp->t_dev));
1579 
1580 	if (COM_ISALIVE(sc) == 0)
1581 		return (0);
1582 
1583 	if (sc->sc_mcr_rts == 0)
1584 		return (0);
1585 
1586 	mutex_spin_enter(&sc->sc_lock);
1587 
1588 	if (block) {
1589 		if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1590 			SET(sc->sc_rx_flags, RX_TTY_BLOCKED);
1591 			com_hwiflow(sc);
1592 		}
1593 	} else {
1594 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
1595 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1596 			com_schedrx(sc);
1597 		}
1598 		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1599 			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED);
1600 			com_hwiflow(sc);
1601 		}
1602 	}
1603 
1604 	mutex_spin_exit(&sc->sc_lock);
1605 	return (1);
1606 }
1607 
1608 /*
1609  * (un)block input via hw flowcontrol
1610  */
1611 void
1612 com_hwiflow(struct com_softc *sc)
1613 {
1614 	struct com_regs *regsp= &sc->sc_regs;
1615 
1616 	if (sc->sc_mcr_rts == 0)
1617 		return;
1618 
1619 	if (ISSET(sc->sc_rx_flags, RX_ANY_BLOCK)) {
1620 		CLR(sc->sc_mcr, sc->sc_mcr_rts);
1621 		CLR(sc->sc_mcr_active, sc->sc_mcr_rts);
1622 	} else {
1623 		SET(sc->sc_mcr, sc->sc_mcr_rts);
1624 		SET(sc->sc_mcr_active, sc->sc_mcr_rts);
1625 	}
1626 	CSR_WRITE_1(regsp, COM_REG_MCR, sc->sc_mcr_active);
1627 }
1628 
1629 
1630 void
1631 comstart(struct tty *tp)
1632 {
1633 	struct com_softc *sc =
1634 	    device_lookup_private(&com_cd, COMUNIT(tp->t_dev));
1635 	struct com_regs *regsp = &sc->sc_regs;
1636 	int s;
1637 
1638 	if (COM_ISALIVE(sc) == 0)
1639 		return;
1640 
1641 	s = spltty();
1642 	if (ISSET(tp->t_state, TS_BUSY | TS_TIMEOUT | TS_TTSTOP))
1643 		goto out;
1644 	if (sc->sc_tx_stopped)
1645 		goto out;
1646 	if (!ttypull(tp))
1647 		goto out;
1648 
1649 	/* Grab the first contiguous region of buffer space. */
1650 	{
1651 		u_char *tba;
1652 		int tbc;
1653 
1654 		tba = tp->t_outq.c_cf;
1655 		tbc = ndqb(&tp->t_outq, 0);
1656 
1657 		mutex_spin_enter(&sc->sc_lock);
1658 
1659 		sc->sc_tba = tba;
1660 		sc->sc_tbc = tbc;
1661 	}
1662 
1663 	SET(tp->t_state, TS_BUSY);
1664 	sc->sc_tx_busy = 1;
1665 
1666 	/* Enable transmit completion interrupts if necessary. */
1667 	if (!ISSET(sc->sc_ier, IER_ETXRDY)) {
1668 		SET(sc->sc_ier, IER_ETXRDY);
1669 		CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
1670 	}
1671 
1672 	/* Output the first chunk of the contiguous buffer. */
1673 	if (!ISSET(sc->sc_hwflags, COM_HW_NO_TXPRELOAD)) {
1674 		u_int n;
1675 
1676 		n = sc->sc_tbc;
1677 		if (n > sc->sc_fifolen)
1678 			n = sc->sc_fifolen;
1679 		CSR_WRITE_MULTI(regsp, COM_REG_TXDATA, sc->sc_tba, n);
1680 		sc->sc_tbc -= n;
1681 		sc->sc_tba += n;
1682 	}
1683 
1684 	mutex_spin_exit(&sc->sc_lock);
1685 out:
1686 	splx(s);
1687 	return;
1688 }
1689 
1690 /*
1691  * Stop output on a line.
1692  */
1693 void
1694 comstop(struct tty *tp, int flag)
1695 {
1696 	struct com_softc *sc =
1697 	    device_lookup_private(&com_cd, COMUNIT(tp->t_dev));
1698 
1699 	mutex_spin_enter(&sc->sc_lock);
1700 	if (ISSET(tp->t_state, TS_BUSY)) {
1701 		/* Stop transmitting at the next chunk. */
1702 		sc->sc_tbc = 0;
1703 		sc->sc_heldtbc = 0;
1704 		if (!ISSET(tp->t_state, TS_TTSTOP))
1705 			SET(tp->t_state, TS_FLUSH);
1706 	}
1707 	mutex_spin_exit(&sc->sc_lock);
1708 }
1709 
1710 void
1711 comdiag(void *arg)
1712 {
1713 	struct com_softc *sc = arg;
1714 	int overflows, floods;
1715 
1716 	mutex_spin_enter(&sc->sc_lock);
1717 	overflows = sc->sc_overflows;
1718 	sc->sc_overflows = 0;
1719 	floods = sc->sc_floods;
1720 	sc->sc_floods = 0;
1721 	sc->sc_errors = 0;
1722 	mutex_spin_exit(&sc->sc_lock);
1723 
1724 	log(LOG_WARNING, "%s: %d silo overflow%s, %d ibuf flood%s\n",
1725 	    device_xname(sc->sc_dev),
1726 	    overflows, overflows == 1 ? "" : "s",
1727 	    floods, floods == 1 ? "" : "s");
1728 }
1729 
1730 integrate void
1731 com_rxsoft(struct com_softc *sc, struct tty *tp)
1732 {
1733 	int (*rint)(int, struct tty *) = tp->t_linesw->l_rint;
1734 	u_char *get, *end;
1735 	u_int cc, scc;
1736 	u_char lsr;
1737 	int code;
1738 
1739 	end = sc->sc_ebuf;
1740 	get = sc->sc_rbget;
1741 	scc = cc = com_rbuf_size - sc->sc_rbavail;
1742 
1743 	if (cc == com_rbuf_size) {
1744 		sc->sc_floods++;
1745 		if (sc->sc_errors++ == 0)
1746 			callout_reset(&sc->sc_diag_callout, 60 * hz,
1747 			    comdiag, sc);
1748 	}
1749 
1750 	/* If not yet open, drop the entire buffer content here */
1751 	if (!ISSET(tp->t_state, TS_ISOPEN)) {
1752 		get += cc << 1;
1753 		if (get >= end)
1754 			get -= com_rbuf_size << 1;
1755 		cc = 0;
1756 	}
1757 	while (cc) {
1758 		code = get[0];
1759 		lsr = get[1];
1760 		if (ISSET(lsr, LSR_OE | LSR_BI | LSR_FE | LSR_PE)) {
1761 			if (ISSET(lsr, LSR_OE)) {
1762 				sc->sc_overflows++;
1763 				if (sc->sc_errors++ == 0)
1764 					callout_reset(&sc->sc_diag_callout,
1765 					    60 * hz, comdiag, sc);
1766 			}
1767 			if (ISSET(lsr, LSR_BI | LSR_FE))
1768 				SET(code, TTY_FE);
1769 			if (ISSET(lsr, LSR_PE))
1770 				SET(code, TTY_PE);
1771 		}
1772 		if ((*rint)(code, tp) == -1) {
1773 			/*
1774 			 * The line discipline's buffer is out of space.
1775 			 */
1776 			if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1777 				/*
1778 				 * We're either not using flow control, or the
1779 				 * line discipline didn't tell us to block for
1780 				 * some reason.  Either way, we have no way to
1781 				 * know when there's more space available, so
1782 				 * just drop the rest of the data.
1783 				 */
1784 				get += cc << 1;
1785 				if (get >= end)
1786 					get -= com_rbuf_size << 1;
1787 				cc = 0;
1788 			} else {
1789 				/*
1790 				 * Don't schedule any more receive processing
1791 				 * until the line discipline tells us there's
1792 				 * space available (through comhwiflow()).
1793 				 * Leave the rest of the data in the input
1794 				 * buffer.
1795 				 */
1796 				SET(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1797 			}
1798 			break;
1799 		}
1800 		get += 2;
1801 		if (get >= end)
1802 			get = sc->sc_rbuf;
1803 		cc--;
1804 	}
1805 
1806 	if (cc != scc) {
1807 		sc->sc_rbget = get;
1808 		mutex_spin_enter(&sc->sc_lock);
1809 
1810 		cc = sc->sc_rbavail += scc - cc;
1811 		/* Buffers should be ok again, release possible block. */
1812 		if (cc >= sc->sc_r_lowat) {
1813 			if (ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
1814 				CLR(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
1815 				SET(sc->sc_ier, IER_ERXRDY);
1816 #ifdef COM_PXA2X0
1817 				if (sc->sc_type == COM_TYPE_PXA2x0)
1818 					SET(sc->sc_ier, IER_ERXTOUT);
1819 #endif
1820 				CSR_WRITE_1(&sc->sc_regs, COM_REG_IER, sc->sc_ier);
1821 			}
1822 			if (ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED)) {
1823 				CLR(sc->sc_rx_flags, RX_IBUF_BLOCKED);
1824 				com_hwiflow(sc);
1825 			}
1826 		}
1827 		mutex_spin_exit(&sc->sc_lock);
1828 	}
1829 }
1830 
1831 integrate void
1832 com_txsoft(struct com_softc *sc, struct tty *tp)
1833 {
1834 
1835 	CLR(tp->t_state, TS_BUSY);
1836 	if (ISSET(tp->t_state, TS_FLUSH))
1837 		CLR(tp->t_state, TS_FLUSH);
1838 	else
1839 		ndflush(&tp->t_outq, (int)(sc->sc_tba - tp->t_outq.c_cf));
1840 	(*tp->t_linesw->l_start)(tp);
1841 }
1842 
1843 integrate void
1844 com_stsoft(struct com_softc *sc, struct tty *tp)
1845 {
1846 	u_char msr, delta;
1847 
1848 	mutex_spin_enter(&sc->sc_lock);
1849 	msr = sc->sc_msr;
1850 	delta = sc->sc_msr_delta;
1851 	sc->sc_msr_delta = 0;
1852 	mutex_spin_exit(&sc->sc_lock);
1853 
1854 	if (ISSET(delta, sc->sc_msr_dcd)) {
1855 		/*
1856 		 * Inform the tty layer that carrier detect changed.
1857 		 */
1858 		(void) (*tp->t_linesw->l_modem)(tp, ISSET(msr, MSR_DCD));
1859 	}
1860 
1861 	if (ISSET(delta, sc->sc_msr_cts)) {
1862 		/* Block or unblock output according to flow control. */
1863 		if (ISSET(msr, sc->sc_msr_cts)) {
1864 			sc->sc_tx_stopped = 0;
1865 			(*tp->t_linesw->l_start)(tp);
1866 		} else {
1867 			sc->sc_tx_stopped = 1;
1868 		}
1869 	}
1870 
1871 #ifdef COM_DEBUG
1872 	if (com_debug)
1873 		comstatus(sc, "com_stsoft");
1874 #endif
1875 }
1876 
1877 void
1878 comsoft(void *arg)
1879 {
1880 	struct com_softc *sc = arg;
1881 	struct tty *tp;
1882 
1883 	if (COM_ISALIVE(sc) == 0)
1884 		return;
1885 
1886 	tp = sc->sc_tty;
1887 
1888 	if (sc->sc_rx_ready) {
1889 		sc->sc_rx_ready = 0;
1890 		com_rxsoft(sc, tp);
1891 	}
1892 
1893 	if (sc->sc_st_check) {
1894 		sc->sc_st_check = 0;
1895 		com_stsoft(sc, tp);
1896 	}
1897 
1898 	if (sc->sc_tx_done) {
1899 		sc->sc_tx_done = 0;
1900 		com_txsoft(sc, tp);
1901 	}
1902 }
1903 
1904 int
1905 comintr(void *arg)
1906 {
1907 	struct com_softc *sc = arg;
1908 	struct com_regs *regsp = &sc->sc_regs;
1909 
1910 	u_char *put, *end;
1911 	u_int cc;
1912 	u_char lsr, iir;
1913 
1914 	if (COM_ISALIVE(sc) == 0)
1915 		return (0);
1916 
1917 	KASSERT(regsp != NULL);
1918 
1919 	mutex_spin_enter(&sc->sc_lock);
1920 	iir = CSR_READ_1(regsp, COM_REG_IIR);
1921 
1922 	/* Handle ns16750-specific busy interrupt. */
1923 #ifdef COM_16750
1924 	int timeout;
1925 	if ((iir & IIR_BUSY) == IIR_BUSY) {
1926 		for (timeout = 10000;
1927 		    (CSR_READ_1(regsp, COM_REG_USR) & 0x1) != 0; timeout--)
1928 			if (timeout <= 0) {
1929 				aprint_error_dev(sc->sc_dev,
1930 				    "timeout while waiting for BUSY interrupt "
1931 				    "acknowledge\n");
1932 				mutex_spin_exit(&sc->sc_lock);
1933 				return (0);
1934 			}
1935 
1936 		CSR_WRITE_1(regsp, COM_REG_LCR, sc->sc_lcr);
1937 		iir = CSR_READ_1(regsp, COM_REG_IIR);
1938 	}
1939 #endif /* COM_16750 */
1940 
1941 
1942 	if (ISSET(iir, IIR_NOPEND)) {
1943 		mutex_spin_exit(&sc->sc_lock);
1944 		return (0);
1945 	}
1946 
1947 	end = sc->sc_ebuf;
1948 	put = sc->sc_rbput;
1949 	cc = sc->sc_rbavail;
1950 
1951 again:	do {
1952 		u_char	msr, delta;
1953 
1954 		lsr = CSR_READ_1(regsp, COM_REG_LSR);
1955 		if (ISSET(lsr, LSR_BI)) {
1956 			int cn_trapped = 0;
1957 
1958 			cn_check_magic(sc->sc_tty->t_dev,
1959 				       CNC_BREAK, com_cnm_state);
1960 			if (cn_trapped)
1961 				continue;
1962 #if defined(KGDB) && !defined(DDB)
1963 			if (ISSET(sc->sc_hwflags, COM_HW_KGDB)) {
1964 				kgdb_connect(1);
1965 				continue;
1966 			}
1967 #endif
1968 		}
1969 
1970 		if (ISSET(lsr, LSR_RCV_MASK) &&
1971 		    !ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
1972 			while (cc > 0) {
1973 				int cn_trapped = 0;
1974 				put[0] = CSR_READ_1(regsp, COM_REG_RXDATA);
1975 				put[1] = lsr;
1976 				cn_check_magic(sc->sc_tty->t_dev,
1977 					       put[0], com_cnm_state);
1978 				if (cn_trapped)
1979 					goto next;
1980 				put += 2;
1981 				if (put >= end)
1982 					put = sc->sc_rbuf;
1983 				cc--;
1984 			next:
1985 				lsr = CSR_READ_1(regsp, COM_REG_LSR);
1986 				if (!ISSET(lsr, LSR_RCV_MASK))
1987 					break;
1988 			}
1989 
1990 			/*
1991 			 * Current string of incoming characters ended because
1992 			 * no more data was available or we ran out of space.
1993 			 * Schedule a receive event if any data was received.
1994 			 * If we're out of space, turn off receive interrupts.
1995 			 */
1996 			sc->sc_rbput = put;
1997 			sc->sc_rbavail = cc;
1998 			if (!ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED))
1999 				sc->sc_rx_ready = 1;
2000 
2001 			/*
2002 			 * See if we are in danger of overflowing a buffer. If
2003 			 * so, use hardware flow control to ease the pressure.
2004 			 */
2005 			if (!ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED) &&
2006 			    cc < sc->sc_r_hiwat) {
2007 				SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
2008 				com_hwiflow(sc);
2009 			}
2010 
2011 			/*
2012 			 * If we're out of space, disable receive interrupts
2013 			 * until the queue has drained a bit.
2014 			 */
2015 			if (!cc) {
2016 				SET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
2017 #ifdef COM_PXA2X0
2018 				if (sc->sc_type == COM_TYPE_PXA2x0)
2019 					CLR(sc->sc_ier, IER_ERXRDY|IER_ERXTOUT);
2020 				else
2021 #endif
2022 					CLR(sc->sc_ier, IER_ERXRDY);
2023 				CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
2024 			}
2025 		} else {
2026 			if ((iir & (IIR_RXRDY|IIR_TXRDY)) == IIR_RXRDY) {
2027 				(void) CSR_READ_1(regsp, COM_REG_RXDATA);
2028 				continue;
2029 			}
2030 		}
2031 
2032 		msr = CSR_READ_1(regsp, COM_REG_MSR);
2033 		delta = msr ^ sc->sc_msr;
2034 		sc->sc_msr = msr;
2035 		if ((sc->sc_pps_state.ppsparam.mode & PPS_CAPTUREBOTH) &&
2036 		    (delta & MSR_DCD)) {
2037 			mutex_spin_enter(&timecounter_lock);
2038 			pps_capture(&sc->sc_pps_state);
2039 			pps_event(&sc->sc_pps_state,
2040 			    (msr & MSR_DCD) ?
2041 			    PPS_CAPTUREASSERT :
2042 			    PPS_CAPTURECLEAR);
2043 			mutex_spin_exit(&timecounter_lock);
2044 		}
2045 
2046 		/*
2047 		 * Process normal status changes
2048 		 */
2049 		if (ISSET(delta, sc->sc_msr_mask)) {
2050 			SET(sc->sc_msr_delta, delta);
2051 
2052 			/*
2053 			 * Stop output immediately if we lose the output
2054 			 * flow control signal or carrier detect.
2055 			 */
2056 			if (ISSET(~msr, sc->sc_msr_mask)) {
2057 				sc->sc_tbc = 0;
2058 				sc->sc_heldtbc = 0;
2059 #ifdef COM_DEBUG
2060 				if (com_debug)
2061 					comstatus(sc, "comintr  ");
2062 #endif
2063 			}
2064 
2065 			sc->sc_st_check = 1;
2066 		}
2067 	} while (!ISSET((iir =
2068 	    CSR_READ_1(regsp, COM_REG_IIR)), IIR_NOPEND) &&
2069 	    /*
2070 	     * Since some device (e.g., ST16C1550) doesn't clear IIR_TXRDY
2071 	     * by IIR read, so we can't do this way: `process all interrupts,
2072 	     * then do TX if possible'.
2073 	     */
2074 	    (iir & IIR_IMASK) != IIR_TXRDY);
2075 
2076 	/*
2077 	 * Read LSR again, since there may be an interrupt between
2078 	 * the last LSR read and IIR read above.
2079 	 */
2080 	lsr = CSR_READ_1(regsp, COM_REG_LSR);
2081 
2082 	/*
2083 	 * See if data can be transmitted as well.
2084 	 * Schedule tx done event if no data left
2085 	 * and tty was marked busy.
2086 	 */
2087 	if (ISSET(lsr, LSR_TXRDY)) {
2088 		/*
2089 		 * If we've delayed a parameter change, do it now, and restart
2090 		 * output.
2091 		 */
2092 		if (sc->sc_heldchange) {
2093 			com_loadchannelregs(sc);
2094 			sc->sc_heldchange = 0;
2095 			sc->sc_tbc = sc->sc_heldtbc;
2096 			sc->sc_heldtbc = 0;
2097 		}
2098 
2099 		/* Output the next chunk of the contiguous buffer, if any. */
2100 		if (sc->sc_tbc > 0) {
2101 			u_int n;
2102 
2103 			n = sc->sc_tbc;
2104 			if (n > sc->sc_fifolen)
2105 				n = sc->sc_fifolen;
2106 			CSR_WRITE_MULTI(regsp, COM_REG_TXDATA, sc->sc_tba, n);
2107 			sc->sc_tbc -= n;
2108 			sc->sc_tba += n;
2109 		} else {
2110 			/* Disable transmit completion interrupts if necessary. */
2111 			if (ISSET(sc->sc_ier, IER_ETXRDY)) {
2112 				CLR(sc->sc_ier, IER_ETXRDY);
2113 				CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
2114 			}
2115 			if (sc->sc_tx_busy) {
2116 				sc->sc_tx_busy = 0;
2117 				sc->sc_tx_done = 1;
2118 			}
2119 		}
2120 	}
2121 
2122 	if (!ISSET((iir = CSR_READ_1(regsp, COM_REG_IIR)), IIR_NOPEND))
2123 		goto again;
2124 
2125 	mutex_spin_exit(&sc->sc_lock);
2126 
2127 	/* Wake up the poller. */
2128 	softint_schedule(sc->sc_si);
2129 
2130 #ifdef RND_COM
2131 	rnd_add_uint32(&sc->rnd_source, iir | lsr);
2132 #endif
2133 
2134 	return (1);
2135 }
2136 
2137 /*
2138  * The following functions are polled getc and putc routines, shared
2139  * by the console and kgdb glue.
2140  *
2141  * The read-ahead code is so that you can detect pending in-band
2142  * cn_magic in polled mode while doing output rather than having to
2143  * wait until the kernel decides it needs input.
2144  */
2145 
2146 #define MAX_READAHEAD	20
2147 static int com_readahead[MAX_READAHEAD];
2148 static int com_readaheadcount = 0;
2149 
2150 int
2151 com_common_getc(dev_t dev, struct com_regs *regsp)
2152 {
2153 	int s = splserial();
2154 	u_char stat, c;
2155 
2156 	/* got a character from reading things earlier */
2157 	if (com_readaheadcount > 0) {
2158 		int i;
2159 
2160 		c = com_readahead[0];
2161 		for (i = 1; i < com_readaheadcount; i++) {
2162 			com_readahead[i-1] = com_readahead[i];
2163 		}
2164 		com_readaheadcount--;
2165 		splx(s);
2166 		return (c);
2167 	}
2168 
2169 	/* block until a character becomes available */
2170 	while (!ISSET(stat = CSR_READ_1(regsp, COM_REG_LSR), LSR_RXRDY))
2171 		;
2172 
2173 	c = CSR_READ_1(regsp, COM_REG_RXDATA);
2174 	stat = CSR_READ_1(regsp, COM_REG_IIR);
2175 	{
2176 		int cn_trapped = 0; /* unused */
2177 #ifdef DDB
2178 		extern int db_active;
2179 		if (!db_active)
2180 #endif
2181 			cn_check_magic(dev, c, com_cnm_state);
2182 	}
2183 	splx(s);
2184 	return (c);
2185 }
2186 
2187 static void
2188 com_common_putc(dev_t dev, struct com_regs *regsp, int c)
2189 {
2190 	int s = splserial();
2191 	int cin, stat, timo;
2192 
2193 	if (com_readaheadcount < MAX_READAHEAD
2194 	     && ISSET(stat = CSR_READ_1(regsp, COM_REG_LSR), LSR_RXRDY)) {
2195 		int cn_trapped = 0;
2196 		cin = CSR_READ_1(regsp, COM_REG_RXDATA);
2197 		stat = CSR_READ_1(regsp, COM_REG_IIR);
2198 		cn_check_magic(dev, cin, com_cnm_state);
2199 		com_readahead[com_readaheadcount++] = cin;
2200 	}
2201 
2202 	/* wait for any pending transmission to finish */
2203 	timo = 150000;
2204 	while (!ISSET(CSR_READ_1(regsp, COM_REG_LSR), LSR_TXRDY) && --timo)
2205 		continue;
2206 
2207 	CSR_WRITE_1(regsp, COM_REG_TXDATA, c);
2208 	COM_BARRIER(regsp, BR | BW);
2209 
2210 	splx(s);
2211 }
2212 
2213 /*
2214  * Initialize UART for use as console or KGDB line.
2215  */
2216 int
2217 cominit(struct com_regs *regsp, int rate, int frequency, int type,
2218     tcflag_t cflag)
2219 {
2220 
2221 	if (bus_space_map(regsp->cr_iot, regsp->cr_iobase, regsp->cr_nports, 0,
2222 		&regsp->cr_ioh))
2223 		return (ENOMEM); /* ??? */
2224 
2225 	if (type == COM_TYPE_OMAP) {
2226 		/* disable before changing settings */
2227 		CSR_WRITE_1(regsp, COM_REG_MDR1, MDR1_MODE_DISABLE);
2228 	}
2229 
2230 	rate = comspeed(rate, frequency, type);
2231 	if (__predict_true(rate != -1)) {
2232 		if (type == COM_TYPE_AU1x00) {
2233 			CSR_WRITE_2(regsp, COM_REG_DLBL, rate);
2234 		} else {
2235 			/* no EFR on alchemy */
2236 			if (type != COM_TYPE_16550_NOERS) {
2237 				CSR_WRITE_1(regsp, COM_REG_LCR, LCR_EERS);
2238 				CSR_WRITE_1(regsp, COM_REG_EFR, 0);
2239 			}
2240 			CSR_WRITE_1(regsp, COM_REG_LCR, LCR_DLAB);
2241 			CSR_WRITE_1(regsp, COM_REG_DLBL, rate & 0xff);
2242 			CSR_WRITE_1(regsp, COM_REG_DLBH, rate >> 8);
2243 		}
2244 	}
2245 	CSR_WRITE_1(regsp, COM_REG_LCR, cflag2lcr(cflag));
2246 	CSR_WRITE_1(regsp, COM_REG_MCR, MCR_DTR | MCR_RTS);
2247 	CSR_WRITE_1(regsp, COM_REG_FIFO,
2248 	    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_1);
2249 
2250 	if (type == COM_TYPE_OMAP) {
2251 		/* setup the fifos.  the FCR value is not used as long
2252 		   as SCR[6] and SCR[7] are 0, which they are at reset
2253 		   and we never touch the SCR register */
2254 		uint8_t rx_fifo_trig = 40;
2255 		uint8_t tx_fifo_trig = 60;
2256 		uint8_t rx_start = 8;
2257 		uint8_t rx_halt = 60;
2258 		uint8_t tlr_value = ((rx_fifo_trig>>2) << 4) | (tx_fifo_trig>>2);
2259 		uint8_t tcr_value = ((rx_start>>2) << 4) | (rx_halt>>2);
2260 
2261 		/* enable access to TCR & TLR */
2262 		CSR_WRITE_1(regsp, COM_REG_MCR, MCR_DTR | MCR_RTS | MCR_TCR_TLR);
2263 
2264 		/* write tcr and tlr values */
2265 		CSR_WRITE_1(regsp, COM_REG_TLR, tlr_value);
2266 		CSR_WRITE_1(regsp, COM_REG_TCR, tcr_value);
2267 
2268 		/* disable access to TCR & TLR */
2269 		CSR_WRITE_1(regsp, COM_REG_MCR, MCR_DTR | MCR_RTS);
2270 
2271 		/* enable again, but mode is based on speed */
2272 		if (rate > 230400) {
2273 			CSR_WRITE_1(regsp, COM_REG_MDR1, MDR1_MODE_UART_13X);
2274 		} else {
2275 			CSR_WRITE_1(regsp, COM_REG_MDR1, MDR1_MODE_UART_16X);
2276 		}
2277 	}
2278 
2279 #ifdef COM_PXA2X0
2280 	if (type == COM_TYPE_PXA2x0)
2281 		CSR_WRITE_1(regsp, COM_REG_IER, IER_EUART);
2282 	else
2283 #endif
2284 		CSR_WRITE_1(regsp, COM_REG_IER, 0);
2285 
2286 	return (0);
2287 }
2288 
2289 int
2290 comcnattach1(struct com_regs *regsp, int rate, int frequency, int type,
2291     tcflag_t cflag)
2292 {
2293 	int res;
2294 
2295 	comcons_info.regs = *regsp;
2296 
2297 	res = cominit(&comcons_info.regs, rate, frequency, type, cflag);
2298 	if (res)
2299 		return (res);
2300 
2301 	cn_tab = &comcons;
2302 	cn_init_magic(&com_cnm_state);
2303 	cn_set_magic("\047\001"); /* default magic is BREAK */
2304 
2305 	comcons_info.frequency = frequency;
2306 	comcons_info.type = type;
2307 	comcons_info.rate = rate;
2308 	comcons_info.cflag = cflag;
2309 
2310 	return (0);
2311 }
2312 
2313 int
2314 comcnattach(bus_space_tag_t iot, bus_addr_t iobase, int rate, int frequency,
2315     int type, tcflag_t cflag)
2316 {
2317 	struct com_regs	regs;
2318 
2319 	memset(&regs, 0, sizeof regs);
2320 	regs.cr_iot = iot;
2321 	regs.cr_iobase = iobase;
2322 	regs.cr_nports = COM_NPORTS;
2323 #ifdef	COM_REGMAP
2324 	memcpy(regs.cr_map, com_std_map, sizeof (regs.cr_map));
2325 #endif
2326 
2327 	return comcnattach1(&regs, rate, frequency, type, cflag);
2328 }
2329 
2330 static int
2331 comcnreattach(void)
2332 {
2333 	return comcnattach1(&comcons_info.regs, comcons_info.rate,
2334 	    comcons_info.frequency, comcons_info.type, comcons_info.cflag);
2335 }
2336 
2337 int
2338 comcngetc(dev_t dev)
2339 {
2340 
2341 	return (com_common_getc(dev, &comcons_info.regs));
2342 }
2343 
2344 /*
2345  * Console kernel output character routine.
2346  */
2347 void
2348 comcnputc(dev_t dev, int c)
2349 {
2350 
2351 	com_common_putc(dev, &comcons_info.regs, c);
2352 }
2353 
2354 void
2355 comcnpollc(dev_t dev, int on)
2356 {
2357 
2358 	com_readaheadcount = 0;
2359 }
2360 
2361 #ifdef KGDB
2362 int
2363 com_kgdb_attach1(struct com_regs *regsp, int rate, int frequency, int type,
2364     tcflag_t cflag)
2365 {
2366 	int res;
2367 
2368 	if (bus_space_is_equal(regsp->cr_iot, comcons_info.regs.cr_iot) &&
2369 	    regsp->cr_iobase == comcons_info.regs.cr_iobase) {
2370 #if !defined(DDB)
2371 		return (EBUSY); /* cannot share with console */
2372 #else
2373 		comkgdbregs = *regsp;
2374 		comkgdbregs.cr_ioh = comcons_info.regs.cr_ioh;
2375 #endif
2376 	} else {
2377 		comkgdbregs = *regsp;
2378 		res = cominit(&comkgdbregs, rate, frequency, type, cflag);
2379 		if (res)
2380 			return (res);
2381 
2382 		/*
2383 		 * XXXfvdl this shouldn't be needed, but the cn_magic goo
2384 		 * expects this to be initialized
2385 		 */
2386 		cn_init_magic(&com_cnm_state);
2387 		cn_set_magic("\047\001");
2388 	}
2389 
2390 	kgdb_attach(com_kgdb_getc, com_kgdb_putc, NULL);
2391 	kgdb_dev = 123; /* unneeded, only to satisfy some tests */
2392 
2393 	return (0);
2394 }
2395 
2396 int
2397 com_kgdb_attach(bus_space_tag_t iot, bus_addr_t iobase, int rate,
2398     int frequency, int type, tcflag_t cflag)
2399 {
2400 	struct com_regs regs;
2401 
2402 	regs.cr_iot = iot;
2403 	regs.cr_nports = COM_NPORTS;
2404 	regs.cr_iobase = iobase;
2405 #ifdef COM_REGMAP
2406 	memcpy(regs.cr_map, com_std_map, sizeof (regs.cr_map));
2407 #endif
2408 
2409 	return com_kgdb_attach1(&regs, rate, frequency, type, cflag);
2410 }
2411 
2412 /* ARGSUSED */
2413 int
2414 com_kgdb_getc(void *arg)
2415 {
2416 
2417 	return (com_common_getc(NODEV, &comkgdbregs));
2418 }
2419 
2420 /* ARGSUSED */
2421 void
2422 com_kgdb_putc(void *arg, int c)
2423 {
2424 
2425 	com_common_putc(NODEV, &comkgdbregs, c);
2426 }
2427 #endif /* KGDB */
2428 
2429 /* helper function to identify the com ports used by
2430  console or KGDB (and not yet autoconf attached) */
2431 int
2432 com_is_console(bus_space_tag_t iot, bus_addr_t iobase, bus_space_handle_t *ioh)
2433 {
2434 	bus_space_handle_t help;
2435 
2436 	if (!comconsattached &&
2437 	    bus_space_is_equal(iot, comcons_info.regs.cr_iot) &&
2438 	    iobase == comcons_info.regs.cr_iobase)
2439 		help = comcons_info.regs.cr_ioh;
2440 #ifdef KGDB
2441 	else if (!com_kgdb_attached &&
2442 	    bus_space_is_equal(iot, comkgdbregs.cr_iot) &&
2443 	    iobase == comkgdbregs.cr_iobase)
2444 		help = comkgdbregs.cr_ioh;
2445 #endif
2446 	else
2447 		return (0);
2448 
2449 	if (ioh)
2450 		*ioh = help;
2451 	return (1);
2452 }
2453 
2454 /*
2455  * this routine exists to serve as a shutdown hook for systems that
2456  * have firmware which doesn't interact properly with a com device in
2457  * FIFO mode.
2458  */
2459 bool
2460 com_cleanup(device_t self, int how)
2461 {
2462 	struct com_softc *sc = device_private(self);
2463 
2464 	if (ISSET(sc->sc_hwflags, COM_HW_FIFO))
2465 		CSR_WRITE_1(&sc->sc_regs, COM_REG_FIFO, 0);
2466 
2467 	return true;
2468 }
2469 
2470 bool
2471 com_suspend(device_t self, const pmf_qual_t *qual)
2472 {
2473 	struct com_softc *sc = device_private(self);
2474 
2475 #if 0
2476 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE) && cn_tab == &comcons)
2477 		cn_tab = &comcons_suspend;
2478 #endif
2479 
2480 	CSR_WRITE_1(&sc->sc_regs, COM_REG_IER, 0);
2481 	(void)CSR_READ_1(&sc->sc_regs, COM_REG_IIR);
2482 
2483 	return true;
2484 }
2485 
2486 bool
2487 com_resume(device_t self, const pmf_qual_t *qual)
2488 {
2489 	struct com_softc *sc = device_private(self);
2490 
2491 	mutex_spin_enter(&sc->sc_lock);
2492 	com_loadchannelregs(sc);
2493 	mutex_spin_exit(&sc->sc_lock);
2494 
2495 	return true;
2496 }
2497