xref: /netbsd-src/sys/dev/ic/com.c (revision 6a493d6bc668897c91594964a732d38505b70cbb)
1 /* $NetBSD: com.c,v 1.322 2013/12/22 18:20:46 matt 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 1.322 2013/12/22 18:20:46 matt 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 		(void)cn_trapped;		\
96 	} while (/* CONSTCOND */ 0)
97 
98 #include <sys/param.h>
99 #include <sys/systm.h>
100 #include <sys/ioctl.h>
101 #include <sys/select.h>
102 #include <sys/poll.h>
103 #include <sys/tty.h>
104 #include <sys/proc.h>
105 #include <sys/conf.h>
106 #include <sys/file.h>
107 #include <sys/uio.h>
108 #include <sys/kernel.h>
109 #include <sys/syslog.h>
110 #include <sys/device.h>
111 #include <sys/malloc.h>
112 #include <sys/timepps.h>
113 #include <sys/vnode.h>
114 #include <sys/kauth.h>
115 #include <sys/intr.h>
116 #ifdef RND_COM
117 #include <sys/rnd.h>
118 #endif
119 
120 
121 #include <sys/bus.h>
122 
123 #include <dev/ic/comreg.h>
124 #include <dev/ic/comvar.h>
125 #include <dev/ic/ns16550reg.h>
126 #include <dev/ic/st16650reg.h>
127 #ifdef COM_HAYESP
128 #include <dev/ic/hayespreg.h>
129 #endif
130 #define	com_lcr	com_cfcr
131 #include <dev/cons.h>
132 
133 #ifdef	COM_REGMAP
134 #define	CSR_WRITE_1(r, o, v)	\
135 	bus_space_write_1((r)->cr_iot, (r)->cr_ioh, (r)->cr_map[o], v)
136 #define	CSR_READ_1(r, o)	\
137 	bus_space_read_1((r)->cr_iot, (r)->cr_ioh, (r)->cr_map[o])
138 #define	CSR_WRITE_2(r, o, v)	\
139 	bus_space_write_2((r)->cr_iot, (r)->cr_ioh, (r)->cr_map[o], v)
140 #define	CSR_READ_2(r, o)	\
141 	bus_space_read_2((r)->cr_iot, (r)->cr_ioh, (r)->cr_map[o])
142 #define	CSR_WRITE_MULTI(r, o, p, n)	\
143 	bus_space_write_multi_1((r)->cr_iot, (r)->cr_ioh, (r)->cr_map[o], p, n)
144 #else
145 #define	CSR_WRITE_1(r, o, v)	\
146 	bus_space_write_1((r)->cr_iot, (r)->cr_ioh, o, v)
147 #define	CSR_READ_1(r, o)	\
148 	bus_space_read_1((r)->cr_iot, (r)->cr_ioh, o)
149 #define	CSR_WRITE_2(r, o, v)	\
150 	bus_space_write_2((r)->cr_iot, (r)->cr_ioh, o, v)
151 #define	CSR_READ_2(r, o)	\
152 	bus_space_read_2((r)->cr_iot, (r)->cr_ioh, o)
153 #define	CSR_WRITE_MULTI(r, o, p, n)	\
154 	bus_space_write_multi_1((r)->cr_iot, (r)->cr_ioh, o, p, n)
155 #endif
156 
157 
158 static void com_enable_debugport(struct com_softc *);
159 
160 void	com_config(struct com_softc *);
161 void	com_shutdown(struct com_softc *);
162 int	comspeed(long, long, int);
163 static	u_char	cflag2lcr(tcflag_t);
164 int	comparam(struct tty *, struct termios *);
165 void	comstart(struct tty *);
166 int	comhwiflow(struct tty *, int);
167 
168 void	com_loadchannelregs(struct com_softc *);
169 void	com_hwiflow(struct com_softc *);
170 void	com_break(struct com_softc *, int);
171 void	com_modem(struct com_softc *, int);
172 void	tiocm_to_com(struct com_softc *, u_long, int);
173 int	com_to_tiocm(struct com_softc *);
174 void	com_iflush(struct com_softc *);
175 
176 int	com_common_getc(dev_t, struct com_regs *);
177 static void	com_common_putc(dev_t, struct com_regs *, int);
178 
179 int	cominit(struct com_regs *, int, int, int, tcflag_t);
180 
181 static int comcnreattach(void);
182 
183 int	comcngetc(dev_t);
184 void	comcnputc(dev_t, int);
185 void	comcnpollc(dev_t, int);
186 
187 #define	integrate	static inline
188 void	comsoft(void *);
189 integrate void com_rxsoft(struct com_softc *, struct tty *);
190 integrate void com_txsoft(struct com_softc *, struct tty *);
191 integrate void com_stsoft(struct com_softc *, struct tty *);
192 integrate void com_schedrx(struct com_softc *);
193 void	comdiag(void *);
194 
195 extern struct cfdriver com_cd;
196 
197 dev_type_open(comopen);
198 dev_type_close(comclose);
199 dev_type_read(comread);
200 dev_type_write(comwrite);
201 dev_type_ioctl(comioctl);
202 dev_type_stop(comstop);
203 dev_type_tty(comtty);
204 dev_type_poll(compoll);
205 
206 static struct comcons_info comcons_info;
207 
208 /*
209  * Following are all routines needed for COM to act as console
210  */
211 static struct consdev comcons = {
212 	NULL, NULL, comcngetc, comcnputc, comcnpollc, NULL, NULL, NULL,
213 	NODEV, CN_NORMAL
214 };
215 
216 
217 const struct cdevsw com_cdevsw = {
218 	comopen, comclose, comread, comwrite, comioctl,
219 	comstop, comtty, compoll, nommap, ttykqfilter, D_TTY
220 };
221 
222 /*
223  * Make this an option variable one can patch.
224  * But be warned:  this must be a power of 2!
225  */
226 u_int com_rbuf_size = COM_RING_SIZE;
227 
228 /* Stop input when 3/4 of the ring is full; restart when only 1/4 is full. */
229 u_int com_rbuf_hiwat = (COM_RING_SIZE * 1) / 4;
230 u_int com_rbuf_lowat = (COM_RING_SIZE * 3) / 4;
231 
232 static int comconsattached;
233 static struct cnm_state com_cnm_state;
234 
235 #ifdef KGDB
236 #include <sys/kgdb.h>
237 
238 static struct com_regs comkgdbregs;
239 static int com_kgdb_attached;
240 
241 int	com_kgdb_getc(void *);
242 void	com_kgdb_putc(void *, int);
243 #endif /* KGDB */
244 
245 #ifdef COM_REGMAP
246 /* initializer for typical 16550-ish hardware */
247 #define	COM_REG_16550	{ \
248 	com_data, com_data, com_dlbl, com_dlbh, com_ier, com_iir, com_fifo, \
249 	com_efr, com_lcr, com_mcr, com_lsr, com_msr }
250 /* 16750-specific register set, additional UART status register */
251 #define	COM_REG_16750	{ \
252 	com_data, com_data, com_dlbl, com_dlbh, com_ier, com_iir, com_fifo, \
253 	com_efr, com_lcr, com_mcr, com_lsr, com_msr, 0, 0, 0, 0, 0, 0, 0, 0, \
254 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, com_usr }
255 
256 #ifdef COM_16750
257 const bus_size_t com_std_map[32] = COM_REG_16750;
258 #else
259 const bus_size_t com_std_map[16] = COM_REG_16550;
260 #endif /* COM_16750 */
261 #endif /* COM_REGMAP */
262 
263 #define	COMUNIT_MASK	0x7ffff
264 #define	COMDIALOUT_MASK	0x80000
265 
266 #define	COMUNIT(x)	(minor(x) & COMUNIT_MASK)
267 #define	COMDIALOUT(x)	(minor(x) & COMDIALOUT_MASK)
268 
269 #define	COM_ISALIVE(sc)	((sc)->enabled != 0 && \
270 			 device_is_active((sc)->sc_dev))
271 
272 #define	BR	BUS_SPACE_BARRIER_READ
273 #define	BW	BUS_SPACE_BARRIER_WRITE
274 #define COM_BARRIER(r, f) \
275 	bus_space_barrier((r)->cr_iot, (r)->cr_ioh, 0, (r)->cr_nports, (f))
276 
277 /*ARGSUSED*/
278 int
279 comspeed(long speed, long frequency, int type)
280 {
281 #define	divrnd(n, q)	(((n)*2/(q)+1)/2)	/* divide and round off */
282 
283 	int x, err;
284 	int divisor = 16;
285 
286 	if ((type == COM_TYPE_OMAP) && (speed > 230400)) {
287 	    divisor = 13;
288 	}
289 
290 #if 0
291 	if (speed == 0)
292 		return (0);
293 #endif
294 	if (speed <= 0)
295 		return (-1);
296 	x = divrnd(frequency / divisor, speed);
297 	if (x <= 0)
298 		return (-1);
299 	err = divrnd(((quad_t)frequency) * 1000 / divisor, speed * x) - 1000;
300 	if (err < 0)
301 		err = -err;
302 	if (err > COM_TOLERANCE)
303 		return (-1);
304 	return (x);
305 
306 #undef	divrnd
307 }
308 
309 #ifdef COM_DEBUG
310 int	com_debug = 0;
311 
312 void comstatus(struct com_softc *, const char *);
313 void
314 comstatus(struct com_softc *sc, const char *str)
315 {
316 	struct tty *tp = sc->sc_tty;
317 
318 	aprint_normal_dev(sc->sc_dev,
319 	    "%s %cclocal  %cdcd %cts_carr_on %cdtr %ctx_stopped\n",
320 	    str,
321 	    ISSET(tp->t_cflag, CLOCAL) ? '+' : '-',
322 	    ISSET(sc->sc_msr, MSR_DCD) ? '+' : '-',
323 	    ISSET(tp->t_state, TS_CARR_ON) ? '+' : '-',
324 	    ISSET(sc->sc_mcr, MCR_DTR) ? '+' : '-',
325 	    sc->sc_tx_stopped ? '+' : '-');
326 
327 	aprint_normal_dev(sc->sc_dev,
328 	    "%s %ccrtscts %ccts %cts_ttstop  %crts rx_flags=0x%x\n",
329 	    str,
330 	    ISSET(tp->t_cflag, CRTSCTS) ? '+' : '-',
331 	    ISSET(sc->sc_msr, MSR_CTS) ? '+' : '-',
332 	    ISSET(tp->t_state, TS_TTSTOP) ? '+' : '-',
333 	    ISSET(sc->sc_mcr, MCR_RTS) ? '+' : '-',
334 	    sc->sc_rx_flags);
335 }
336 #endif
337 
338 int
339 com_probe_subr(struct com_regs *regs)
340 {
341 
342 	/* force access to id reg */
343 	CSR_WRITE_1(regs, COM_REG_LCR, LCR_8BITS);
344 	CSR_WRITE_1(regs, COM_REG_IIR, 0);
345 	if ((CSR_READ_1(regs, COM_REG_LCR) != LCR_8BITS) ||
346 	    (CSR_READ_1(regs, COM_REG_IIR) & 0x38))
347 		return (0);
348 
349 	return (1);
350 }
351 
352 int
353 comprobe1(bus_space_tag_t iot, bus_space_handle_t ioh)
354 {
355 	struct com_regs	regs;
356 
357 	regs.cr_iot = iot;
358 	regs.cr_ioh = ioh;
359 #ifdef	COM_REGMAP
360 	memcpy(regs.cr_map, com_std_map, sizeof (regs.cr_map));
361 #endif
362 
363 	return com_probe_subr(&regs);
364 }
365 
366 /*
367  * No locking in this routine; it is only called during attach,
368  * or with the port already locked.
369  */
370 static void
371 com_enable_debugport(struct com_softc *sc)
372 {
373 
374 	/* Turn on line break interrupt, set carrier. */
375 	sc->sc_ier = IER_ERXRDY;
376 	if (sc->sc_type == COM_TYPE_PXA2x0)
377 		sc->sc_ier |= IER_EUART | IER_ERXTOUT;
378 	CSR_WRITE_1(&sc->sc_regs, COM_REG_IER, sc->sc_ier);
379 	SET(sc->sc_mcr, MCR_DTR | MCR_RTS);
380 	CSR_WRITE_1(&sc->sc_regs, COM_REG_MCR, sc->sc_mcr);
381 }
382 
383 void
384 com_attach_subr(struct com_softc *sc)
385 {
386 	struct com_regs *regsp = &sc->sc_regs;
387 	struct tty *tp;
388 #if defined(COM_16650) || defined(COM_16750)
389 	u_int8_t lcr;
390 #endif
391 	const char *fifo_msg = NULL;
392 	prop_dictionary_t	dict;
393 	bool is_console = true;
394 
395 	aprint_naive("\n");
396 
397 	dict = device_properties(sc->sc_dev);
398 	prop_dictionary_get_bool(dict, "is_console", &is_console);
399 
400 	callout_init(&sc->sc_diag_callout, 0);
401 	mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_HIGH);
402 
403 	/* Disable interrupts before configuring the device. */
404 	if (sc->sc_type == COM_TYPE_PXA2x0)
405 		sc->sc_ier = IER_EUART;
406 	else
407 		sc->sc_ier = 0;
408 
409 	CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
410 
411 	if (bus_space_is_equal(regsp->cr_iot, comcons_info.regs.cr_iot) &&
412 	    regsp->cr_iobase == comcons_info.regs.cr_iobase) {
413 		comconsattached = 1;
414 
415 		if (cn_tab == NULL && comcnreattach() != 0) {
416 			printf("can't re-init serial console @%lx\n",
417 			    (u_long)comcons_info.regs.cr_iobase);
418 		}
419 
420 #ifdef COM_16750
421 		/* Use in comintr(). */
422  		sc->sc_lcr = cflag2lcr(comcons_info.cflag);
423 #endif
424 
425 		/* Make sure the console is always "hardwired". */
426 		delay(10000);			/* wait for output to finish */
427 		if (is_console) {
428 			SET(sc->sc_hwflags, COM_HW_CONSOLE);
429 		}
430 
431 		SET(sc->sc_swflags, TIOCFLAG_SOFTCAR);
432 	}
433 
434 	/* Probe for FIFO */
435 	switch (sc->sc_type) {
436 	case COM_TYPE_HAYESP:
437 		goto fifodone;
438 
439 	case COM_TYPE_AU1x00:
440 		sc->sc_fifolen = 16;
441 		fifo_msg = "Au1X00 UART, working fifo";
442 		SET(sc->sc_hwflags, COM_HW_FIFO);
443 		goto fifodelay;
444 
445 	case COM_TYPE_16550_NOERS:
446 		sc->sc_fifolen = 16;
447 		fifo_msg = "ns16650, no ERS, working fifo";
448 		SET(sc->sc_hwflags, COM_HW_FIFO);
449 		goto fifodelay;
450 
451 	case COM_TYPE_OMAP:
452 		sc->sc_fifolen = 64;
453 		fifo_msg = "OMAP UART, working fifo";
454 		SET(sc->sc_hwflags, COM_HW_FIFO);
455 		goto fifodelay;
456 	}
457 
458 	sc->sc_fifolen = 1;
459 	/* look for a NS 16550AF UART with FIFOs */
460 	CSR_WRITE_1(regsp, COM_REG_FIFO,
461 	    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_14);
462 	delay(100);
463 	if (ISSET(CSR_READ_1(regsp, COM_REG_IIR), IIR_FIFO_MASK)
464 	    == IIR_FIFO_MASK)
465 		if (ISSET(CSR_READ_1(regsp, COM_REG_FIFO), FIFO_TRIGGER_14)
466 		    == FIFO_TRIGGER_14) {
467 			SET(sc->sc_hwflags, COM_HW_FIFO);
468 
469 #ifdef COM_16650
470 			/*
471 			 * IIR changes into the EFR if LCR is set to LCR_EERS
472 			 * on 16650s. We also know IIR != 0 at this point.
473 			 * Write 0 into the EFR, and read it. If the result
474 			 * is 0, we have a 16650.
475 			 *
476 			 * Older 16650s were broken; the test to detect them
477 			 * is taken from the Linux driver. Apparently
478 			 * setting DLAB enable gives access to the EFR on
479 			 * these chips.
480 			 */
481 			lcr = CSR_READ_1(regsp, COM_REG_LCR);
482 			CSR_WRITE_1(regsp, COM_REG_LCR, LCR_EERS);
483 			CSR_WRITE_1(regsp, COM_REG_EFR, 0);
484 			if (CSR_READ_1(regsp, COM_REG_EFR) == 0) {
485 				CSR_WRITE_1(regsp, COM_REG_LCR, lcr | LCR_DLAB);
486 				if (CSR_READ_1(regsp, COM_REG_EFR) == 0) {
487 					CLR(sc->sc_hwflags, COM_HW_FIFO);
488 					sc->sc_fifolen = 0;
489 				} else {
490 					SET(sc->sc_hwflags, COM_HW_FLOW);
491 					sc->sc_fifolen = 32;
492 				}
493 			} else
494 #endif
495 				sc->sc_fifolen = 16;
496 
497 #ifdef COM_16750
498 			/*
499 			 * TL16C750 can enable 64byte FIFO, only when DLAB
500 			 * is 1.  However, some 16750 may always enable.  For
501 			 * example, restrictions according to DLAB in a data
502 			 * sheet for SC16C750 were not described.
503 			 * Please enable 'options COM_16650', supposing you
504 			 * use SC16C750.  Probably 32 bytes of FIFO and HW FLOW
505 			 * should become effective.
506 			 */
507 			uint8_t iir1, iir2;
508 			const uint8_t fcr = FIFO_ENABLE | FIFO_TRIGGER_14;
509 
510 			lcr = CSR_READ_1(regsp, COM_REG_LCR);
511 			CSR_WRITE_1(regsp, COM_REG_LCR, lcr & ~LCR_DLAB);
512 			CSR_WRITE_1(regsp, COM_REG_FIFO, fcr | FIFO_64B_ENABLE);
513 			iir1 = CSR_READ_1(regsp, COM_REG_IIR);
514 			CSR_WRITE_1(regsp, COM_REG_FIFO, fcr);
515 			CSR_WRITE_1(regsp, COM_REG_LCR, lcr | LCR_DLAB);
516 			CSR_WRITE_1(regsp, COM_REG_FIFO, fcr | FIFO_64B_ENABLE);
517 			iir2 = CSR_READ_1(regsp, COM_REG_IIR);
518 
519 			CSR_WRITE_1(regsp, COM_REG_LCR, lcr);
520 
521 			if (!ISSET(iir1, IIR_64B_FIFO) &&
522 			    ISSET(iir2, IIR_64B_FIFO)) {
523 				/* It is TL16C750. */
524 				sc->sc_fifolen = 64;
525 				SET(sc->sc_hwflags, COM_HW_AFE);
526 			} else
527 				CSR_WRITE_1(regsp, COM_REG_FIFO, fcr);
528 #endif
529 
530 #ifdef COM_16650
531 			CSR_WRITE_1(regsp, COM_REG_LCR, lcr);
532 			if (sc->sc_fifolen == 0)
533 				fifo_msg = "st16650, broken fifo";
534 			else if (sc->sc_fifolen == 32)
535 				fifo_msg = "st16650a, working fifo";
536 			else
537 #endif
538 #ifdef COM_16750
539 			if (sc->sc_fifolen == 64)
540 				fifo_msg = "tl16c750, working fifo";
541 			else
542 #endif
543 				fifo_msg = "ns16550a, working fifo";
544 		} else
545 			fifo_msg = "ns16550, broken fifo";
546 	else
547 		fifo_msg = "ns8250 or ns16450, no fifo";
548 	CSR_WRITE_1(regsp, COM_REG_FIFO, 0);
549 fifodelay:
550 	/*
551 	 * Some chips will clear down both Tx and Rx FIFOs when zero is
552 	 * written to com_fifo. If this chip is the console, writing zero
553 	 * results in some of the chip/FIFO description being lost, so delay
554 	 * printing it until now.
555 	 */
556 	delay(10);
557 	aprint_normal(": %s\n", fifo_msg);
558 	if (ISSET(sc->sc_hwflags, COM_HW_TXFIFO_DISABLE)) {
559 		sc->sc_fifolen = 1;
560 		aprint_normal_dev(sc->sc_dev, "txfifo disabled\n");
561 	}
562 
563 fifodone:
564 
565 	tp = tty_alloc();
566 	tp->t_oproc = comstart;
567 	tp->t_param = comparam;
568 	tp->t_hwiflow = comhwiflow;
569 	tp->t_softc = sc;
570 
571 	sc->sc_tty = tp;
572 	sc->sc_rbuf = malloc(com_rbuf_size << 1, M_DEVBUF, M_NOWAIT);
573 	sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
574 	sc->sc_rbavail = com_rbuf_size;
575 	if (sc->sc_rbuf == NULL) {
576 		aprint_error_dev(sc->sc_dev,
577 		    "unable to allocate ring buffer\n");
578 		return;
579 	}
580 	sc->sc_ebuf = sc->sc_rbuf + (com_rbuf_size << 1);
581 
582 	tty_attach(tp);
583 
584 	if (!ISSET(sc->sc_hwflags, COM_HW_NOIEN))
585 		SET(sc->sc_mcr, MCR_IENABLE);
586 
587 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
588 		int maj;
589 
590 		/* locate the major number */
591 		maj = cdevsw_lookup_major(&com_cdevsw);
592 
593 		tp->t_dev = cn_tab->cn_dev = makedev(maj,
594 						     device_unit(sc->sc_dev));
595 
596 		aprint_normal_dev(sc->sc_dev, "console\n");
597 	}
598 
599 #ifdef KGDB
600 	/*
601 	 * Allow kgdb to "take over" this port.  If this is
602 	 * not the console and is the kgdb device, it has
603 	 * exclusive use.  If it's the console _and_ the
604 	 * kgdb device, it doesn't.
605 	 */
606 	if (bus_space_is_equal(regsp->cr_iot, comkgdbregs.cr_iot) &&
607 	    regsp->cr_iobase == comkgdbregs.cr_iobase) {
608 		if (!ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
609 			com_kgdb_attached = 1;
610 
611 			SET(sc->sc_hwflags, COM_HW_KGDB);
612 		}
613 		aprint_normal_dev(sc->sc_dev, "kgdb\n");
614 	}
615 #endif
616 
617 	sc->sc_si = softint_establish(SOFTINT_SERIAL, comsoft, sc);
618 
619 #ifdef RND_COM
620 	rnd_attach_source(&sc->rnd_source, device_xname(sc->sc_dev),
621 			  RND_TYPE_TTY, 0);
622 #endif
623 
624 	/* if there are no enable/disable functions, assume the device
625 	   is always enabled */
626 	if (!sc->enable)
627 		sc->enabled = 1;
628 
629 	com_config(sc);
630 
631 	SET(sc->sc_hwflags, COM_HW_DEV_OK);
632 }
633 
634 void
635 com_config(struct com_softc *sc)
636 {
637 	struct com_regs *regsp = &sc->sc_regs;
638 
639 	/* Disable interrupts before configuring the device. */
640 	if (sc->sc_type == COM_TYPE_PXA2x0)
641 		sc->sc_ier = IER_EUART;
642 	else
643 		sc->sc_ier = 0;
644 	CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
645 	(void) CSR_READ_1(regsp, COM_REG_IIR);
646 
647 #ifdef COM_HAYESP
648 	/* Look for a Hayes ESP board. */
649 	if (sc->sc_type == COM_TYPE_HAYESP) {
650 
651 		/* Set 16550 compatibility mode */
652 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD1,
653 				  HAYESP_SETMODE);
654 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
655 				  HAYESP_MODE_FIFO|HAYESP_MODE_RTS|
656 				  HAYESP_MODE_SCALE);
657 
658 		/* Set RTS/CTS flow control */
659 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD1,
660 				  HAYESP_SETFLOWTYPE);
661 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
662 				  HAYESP_FLOW_RTS);
663 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
664 				  HAYESP_FLOW_CTS);
665 
666 		/* Set flow control levels */
667 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD1,
668 				  HAYESP_SETRXFLOW);
669 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
670 				  HAYESP_HIBYTE(HAYESP_RXHIWMARK));
671 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
672 				  HAYESP_LOBYTE(HAYESP_RXHIWMARK));
673 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
674 				  HAYESP_HIBYTE(HAYESP_RXLOWMARK));
675 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
676 				  HAYESP_LOBYTE(HAYESP_RXLOWMARK));
677 	}
678 #endif
679 
680 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE|COM_HW_KGDB))
681 		com_enable_debugport(sc);
682 }
683 
684 #if 0
685 static int
686 comcngetc_detached(dev_t dev)
687 {
688 	return 0;
689 }
690 
691 static void
692 comcnputc_detached(dev_t dev, int c)
693 {
694 }
695 #endif
696 
697 int
698 com_detach(device_t self, int flags)
699 {
700 	struct com_softc *sc = device_private(self);
701 	int maj, mn;
702 
703 	if (ISSET(sc->sc_hwflags, COM_HW_KGDB))
704 		return EBUSY;
705 
706 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE) &&
707 	    (flags & DETACH_SHUTDOWN) != 0)
708 		return EBUSY;
709 
710 	if (sc->disable != NULL && sc->enabled != 0) {
711 		(*sc->disable)(sc);
712 		sc->enabled = 0;
713 	}
714 
715 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
716 		comconsattached = 0;
717 		cn_tab = NULL;
718 	}
719 
720 	/* locate the major number */
721 	maj = cdevsw_lookup_major(&com_cdevsw);
722 
723 	/* Nuke the vnodes for any open instances. */
724 	mn = device_unit(self);
725 	vdevgone(maj, mn, mn, VCHR);
726 
727 	mn |= COMDIALOUT_MASK;
728 	vdevgone(maj, mn, mn, VCHR);
729 
730 	if (sc->sc_rbuf == NULL) {
731 		/*
732 		 * Ring buffer allocation failed in the com_attach_subr,
733 		 * only the tty is allocated, and nothing else.
734 		 */
735 		tty_free(sc->sc_tty);
736 		return 0;
737 	}
738 
739 	/* Free the receive buffer. */
740 	free(sc->sc_rbuf, M_DEVBUF);
741 
742 	/* Detach and free the tty. */
743 	tty_detach(sc->sc_tty);
744 	tty_free(sc->sc_tty);
745 
746 	/* Unhook the soft interrupt handler. */
747 	softint_disestablish(sc->sc_si);
748 
749 #ifdef RND_COM
750 	/* Unhook the entropy source. */
751 	rnd_detach_source(&sc->rnd_source);
752 #endif
753 	callout_destroy(&sc->sc_diag_callout);
754 
755 	/* Destroy the lock. */
756 	mutex_destroy(&sc->sc_lock);
757 
758 	return (0);
759 }
760 
761 void
762 com_shutdown(struct com_softc *sc)
763 {
764 	struct tty *tp = sc->sc_tty;
765 
766 	mutex_spin_enter(&sc->sc_lock);
767 
768 	/* If we were asserting flow control, then deassert it. */
769 	SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
770 	com_hwiflow(sc);
771 
772 	/* Clear any break condition set with TIOCSBRK. */
773 	com_break(sc, 0);
774 
775 	/*
776 	 * Hang up if necessary.  Wait a bit, so the other side has time to
777 	 * notice even if we immediately open the port again.
778 	 * Avoid tsleeping above splhigh().
779 	 */
780 	if (ISSET(tp->t_cflag, HUPCL)) {
781 		com_modem(sc, 0);
782 		mutex_spin_exit(&sc->sc_lock);
783 		/* XXX will only timeout */
784 		(void) kpause(ttclos, false, hz, NULL);
785 		mutex_spin_enter(&sc->sc_lock);
786 	}
787 
788 	/* Turn off interrupts. */
789 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
790 		sc->sc_ier = IER_ERXRDY; /* interrupt on break */
791 		if (sc->sc_type == COM_TYPE_PXA2x0)
792 			sc->sc_ier |= IER_ERXTOUT;
793 	} else
794 		sc->sc_ier = 0;
795 
796 	if (sc->sc_type == COM_TYPE_PXA2x0)
797 		sc->sc_ier |= IER_EUART;
798 
799 	CSR_WRITE_1(&sc->sc_regs, COM_REG_IER, sc->sc_ier);
800 
801 	mutex_spin_exit(&sc->sc_lock);
802 
803 	if (sc->disable) {
804 #ifdef DIAGNOSTIC
805 		if (!sc->enabled)
806 			panic("com_shutdown: not enabled?");
807 #endif
808 		(*sc->disable)(sc);
809 		sc->enabled = 0;
810 	}
811 }
812 
813 int
814 comopen(dev_t dev, int flag, int mode, struct lwp *l)
815 {
816 	struct com_softc *sc;
817 	struct tty *tp;
818 	int s;
819 	int error;
820 
821 	sc = device_lookup_private(&com_cd, COMUNIT(dev));
822 	if (sc == NULL || !ISSET(sc->sc_hwflags, COM_HW_DEV_OK) ||
823 		sc->sc_rbuf == NULL)
824 		return (ENXIO);
825 
826 	if (!device_is_active(sc->sc_dev))
827 		return (ENXIO);
828 
829 #ifdef KGDB
830 	/*
831 	 * If this is the kgdb port, no other use is permitted.
832 	 */
833 	if (ISSET(sc->sc_hwflags, COM_HW_KGDB))
834 		return (EBUSY);
835 #endif
836 
837 	tp = sc->sc_tty;
838 
839 	if (kauth_authorize_device_tty(l->l_cred, KAUTH_DEVICE_TTY_OPEN, tp))
840 		return (EBUSY);
841 
842 	s = spltty();
843 
844 	/*
845 	 * Do the following iff this is a first open.
846 	 */
847 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
848 		struct termios t;
849 
850 		tp->t_dev = dev;
851 
852 		if (sc->enable) {
853 			if ((*sc->enable)(sc)) {
854 				splx(s);
855 				aprint_error_dev(sc->sc_dev,
856 				    "device enable failed\n");
857 				return (EIO);
858 			}
859 			mutex_spin_enter(&sc->sc_lock);
860 			sc->enabled = 1;
861 			com_config(sc);
862 		} else {
863 			mutex_spin_enter(&sc->sc_lock);
864 		}
865 
866 		/* Turn on interrupts. */
867 		sc->sc_ier = IER_ERXRDY | IER_ERLS;
868 		if (!ISSET(tp->t_cflag, CLOCAL))
869 			sc->sc_ier |= IER_EMSC;
870 
871 		if (sc->sc_type == COM_TYPE_PXA2x0)
872 			sc->sc_ier |= IER_EUART | IER_ERXTOUT;
873 		CSR_WRITE_1(&sc->sc_regs, COM_REG_IER, sc->sc_ier);
874 
875 		/* Fetch the current modem control status, needed later. */
876 		sc->sc_msr = CSR_READ_1(&sc->sc_regs, COM_REG_MSR);
877 
878 		/* Clear PPS capture state on first open. */
879 		mutex_spin_enter(&timecounter_lock);
880 		memset(&sc->sc_pps_state, 0, sizeof(sc->sc_pps_state));
881 		sc->sc_pps_state.ppscap = PPS_CAPTUREASSERT | PPS_CAPTURECLEAR;
882 		pps_init(&sc->sc_pps_state);
883 		mutex_spin_exit(&timecounter_lock);
884 
885 		mutex_spin_exit(&sc->sc_lock);
886 
887 		/*
888 		 * Initialize the termios status to the defaults.  Add in the
889 		 * sticky bits from TIOCSFLAGS.
890 		 */
891 		if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
892 			t.c_ospeed = comcons_info.rate;
893 			t.c_cflag = comcons_info.cflag;
894 		} else {
895 			t.c_ospeed = TTYDEF_SPEED;
896 			t.c_cflag = TTYDEF_CFLAG;
897 		}
898 		t.c_ispeed = t.c_ospeed;
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 		mutex_spin_enter(&sc->sc_lock);
915 
916 		/*
917 		 * Turn on DTR.  We must always do this, even if carrier is not
918 		 * present, because otherwise we'd have to use TIOCSDTR
919 		 * immediately after setting CLOCAL, which applications do not
920 		 * expect.  We always assert DTR while the device is open
921 		 * unless explicitly requested to deassert it.
922 		 */
923 		com_modem(sc, 1);
924 
925 		/* Clear the input ring, and unblock. */
926 		sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
927 		sc->sc_rbavail = com_rbuf_size;
928 		com_iflush(sc);
929 		CLR(sc->sc_rx_flags, RX_ANY_BLOCK);
930 		com_hwiflow(sc);
931 
932 #ifdef COM_DEBUG
933 		if (com_debug)
934 			comstatus(sc, "comopen  ");
935 #endif
936 
937 		mutex_spin_exit(&sc->sc_lock);
938 	}
939 
940 	splx(s);
941 
942 	error = ttyopen(tp, COMDIALOUT(dev), ISSET(flag, O_NONBLOCK));
943 	if (error)
944 		goto bad;
945 
946 	error = (*tp->t_linesw->l_open)(dev, tp);
947 	if (error)
948 		goto bad;
949 
950 	return (0);
951 
952 bad:
953 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
954 		/*
955 		 * We failed to open the device, and nobody else had it opened.
956 		 * Clean up the state as appropriate.
957 		 */
958 		com_shutdown(sc);
959 	}
960 
961 	return (error);
962 }
963 
964 int
965 comclose(dev_t dev, int flag, int mode, struct lwp *l)
966 {
967 	struct com_softc *sc =
968 	    device_lookup_private(&com_cd, COMUNIT(dev));
969 	struct tty *tp = sc->sc_tty;
970 
971 	/* XXX This is for cons.c. */
972 	if (!ISSET(tp->t_state, TS_ISOPEN))
973 		return (0);
974 
975 	(*tp->t_linesw->l_close)(tp, flag);
976 	ttyclose(tp);
977 
978 	if (COM_ISALIVE(sc) == 0)
979 		return (0);
980 
981 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
982 		/*
983 		 * Although we got a last close, the device may still be in
984 		 * use; e.g. if this was the dialout node, and there are still
985 		 * processes waiting for carrier on the non-dialout node.
986 		 */
987 		com_shutdown(sc);
988 	}
989 
990 	return (0);
991 }
992 
993 int
994 comread(dev_t dev, struct uio *uio, int flag)
995 {
996 	struct com_softc *sc =
997 	    device_lookup_private(&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 =
1010 	    device_lookup_private(&com_cd, COMUNIT(dev));
1011 	struct tty *tp = sc->sc_tty;
1012 
1013 	if (COM_ISALIVE(sc) == 0)
1014 		return (EIO);
1015 
1016 	return ((*tp->t_linesw->l_write)(tp, uio, flag));
1017 }
1018 
1019 int
1020 compoll(dev_t dev, int events, struct lwp *l)
1021 {
1022 	struct com_softc *sc =
1023 	    device_lookup_private(&com_cd, COMUNIT(dev));
1024 	struct tty *tp = sc->sc_tty;
1025 
1026 	if (COM_ISALIVE(sc) == 0)
1027 		return (POLLHUP);
1028 
1029 	return ((*tp->t_linesw->l_poll)(tp, events, l));
1030 }
1031 
1032 struct tty *
1033 comtty(dev_t dev)
1034 {
1035 	struct com_softc *sc =
1036 	    device_lookup_private(&com_cd, COMUNIT(dev));
1037 	struct tty *tp = sc->sc_tty;
1038 
1039 	return (tp);
1040 }
1041 
1042 int
1043 comioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
1044 {
1045 	struct com_softc *sc;
1046 	struct tty *tp;
1047 	int error;
1048 
1049 	sc = device_lookup_private(&com_cd, COMUNIT(dev));
1050 	if (sc == NULL)
1051 		return ENXIO;
1052 	if (COM_ISALIVE(sc) == 0)
1053 		return (EIO);
1054 
1055 	tp = sc->sc_tty;
1056 
1057 	error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, l);
1058 	if (error != EPASSTHROUGH)
1059 		return (error);
1060 
1061 	error = ttioctl(tp, cmd, data, flag, l);
1062 	if (error != EPASSTHROUGH)
1063 		return (error);
1064 
1065 	error = 0;
1066 	switch (cmd) {
1067 	case TIOCSFLAGS:
1068 		error = kauth_authorize_device_tty(l->l_cred,
1069 		    KAUTH_DEVICE_TTY_PRIVSET, tp);
1070 		break;
1071 	default:
1072 		/* nothing */
1073 		break;
1074 	}
1075 	if (error) {
1076 		return error;
1077 	}
1078 
1079 	mutex_spin_enter(&sc->sc_lock);
1080 
1081 	switch (cmd) {
1082 	case TIOCSBRK:
1083 		com_break(sc, 1);
1084 		break;
1085 
1086 	case TIOCCBRK:
1087 		com_break(sc, 0);
1088 		break;
1089 
1090 	case TIOCSDTR:
1091 		com_modem(sc, 1);
1092 		break;
1093 
1094 	case TIOCCDTR:
1095 		com_modem(sc, 0);
1096 		break;
1097 
1098 	case TIOCGFLAGS:
1099 		*(int *)data = sc->sc_swflags;
1100 		break;
1101 
1102 	case TIOCSFLAGS:
1103 		sc->sc_swflags = *(int *)data;
1104 		break;
1105 
1106 	case TIOCMSET:
1107 	case TIOCMBIS:
1108 	case TIOCMBIC:
1109 		tiocm_to_com(sc, cmd, *(int *)data);
1110 		break;
1111 
1112 	case TIOCMGET:
1113 		*(int *)data = com_to_tiocm(sc);
1114 		break;
1115 
1116 	case PPS_IOC_CREATE:
1117 	case PPS_IOC_DESTROY:
1118 	case PPS_IOC_GETPARAMS:
1119 	case PPS_IOC_SETPARAMS:
1120 	case PPS_IOC_GETCAP:
1121 	case PPS_IOC_FETCH:
1122 #ifdef PPS_SYNC
1123 	case PPS_IOC_KCBIND:
1124 #endif
1125 		mutex_spin_enter(&timecounter_lock);
1126 		error = pps_ioctl(cmd, data, &sc->sc_pps_state);
1127 		mutex_spin_exit(&timecounter_lock);
1128 		break;
1129 
1130 	case TIOCDCDTIMESTAMP:	/* XXX old, overloaded  API used by xntpd v3 */
1131 		mutex_spin_enter(&timecounter_lock);
1132 #ifndef PPS_TRAILING_EDGE
1133 		TIMESPEC_TO_TIMEVAL((struct timeval *)data,
1134 		    &sc->sc_pps_state.ppsinfo.assert_timestamp);
1135 #else
1136 		TIMESPEC_TO_TIMEVAL((struct timeval *)data,
1137 		    &sc->sc_pps_state.ppsinfo.clear_timestamp);
1138 #endif
1139 		mutex_spin_exit(&timecounter_lock);
1140 		break;
1141 
1142 	default:
1143 		error = EPASSTHROUGH;
1144 		break;
1145 	}
1146 
1147 	mutex_spin_exit(&sc->sc_lock);
1148 
1149 #ifdef COM_DEBUG
1150 	if (com_debug)
1151 		comstatus(sc, "comioctl ");
1152 #endif
1153 
1154 	return (error);
1155 }
1156 
1157 integrate void
1158 com_schedrx(struct com_softc *sc)
1159 {
1160 
1161 	sc->sc_rx_ready = 1;
1162 
1163 	/* Wake up the poller. */
1164 	softint_schedule(sc->sc_si);
1165 }
1166 
1167 void
1168 com_break(struct com_softc *sc, int onoff)
1169 {
1170 
1171 	if (onoff)
1172 		SET(sc->sc_lcr, LCR_SBREAK);
1173 	else
1174 		CLR(sc->sc_lcr, LCR_SBREAK);
1175 
1176 	if (!sc->sc_heldchange) {
1177 		if (sc->sc_tx_busy) {
1178 			sc->sc_heldtbc = sc->sc_tbc;
1179 			sc->sc_tbc = 0;
1180 			sc->sc_heldchange = 1;
1181 		} else
1182 			com_loadchannelregs(sc);
1183 	}
1184 }
1185 
1186 void
1187 com_modem(struct com_softc *sc, int onoff)
1188 {
1189 
1190 	if (sc->sc_mcr_dtr == 0)
1191 		return;
1192 
1193 	if (onoff)
1194 		SET(sc->sc_mcr, sc->sc_mcr_dtr);
1195 	else
1196 		CLR(sc->sc_mcr, sc->sc_mcr_dtr);
1197 
1198 	if (!sc->sc_heldchange) {
1199 		if (sc->sc_tx_busy) {
1200 			sc->sc_heldtbc = sc->sc_tbc;
1201 			sc->sc_tbc = 0;
1202 			sc->sc_heldchange = 1;
1203 		} else
1204 			com_loadchannelregs(sc);
1205 	}
1206 }
1207 
1208 void
1209 tiocm_to_com(struct com_softc *sc, u_long how, int ttybits)
1210 {
1211 	u_char combits;
1212 
1213 	combits = 0;
1214 	if (ISSET(ttybits, TIOCM_DTR))
1215 		SET(combits, MCR_DTR);
1216 	if (ISSET(ttybits, TIOCM_RTS))
1217 		SET(combits, MCR_RTS);
1218 
1219 	switch (how) {
1220 	case TIOCMBIC:
1221 		CLR(sc->sc_mcr, combits);
1222 		break;
1223 
1224 	case TIOCMBIS:
1225 		SET(sc->sc_mcr, combits);
1226 		break;
1227 
1228 	case TIOCMSET:
1229 		CLR(sc->sc_mcr, MCR_DTR | MCR_RTS);
1230 		SET(sc->sc_mcr, combits);
1231 		break;
1232 	}
1233 
1234 	if (!sc->sc_heldchange) {
1235 		if (sc->sc_tx_busy) {
1236 			sc->sc_heldtbc = sc->sc_tbc;
1237 			sc->sc_tbc = 0;
1238 			sc->sc_heldchange = 1;
1239 		} else
1240 			com_loadchannelregs(sc);
1241 	}
1242 }
1243 
1244 int
1245 com_to_tiocm(struct com_softc *sc)
1246 {
1247 	u_char combits;
1248 	int ttybits = 0;
1249 
1250 	combits = sc->sc_mcr;
1251 	if (ISSET(combits, MCR_DTR))
1252 		SET(ttybits, TIOCM_DTR);
1253 	if (ISSET(combits, MCR_RTS))
1254 		SET(ttybits, TIOCM_RTS);
1255 
1256 	combits = sc->sc_msr;
1257 	if (ISSET(combits, MSR_DCD))
1258 		SET(ttybits, TIOCM_CD);
1259 	if (ISSET(combits, MSR_CTS))
1260 		SET(ttybits, TIOCM_CTS);
1261 	if (ISSET(combits, MSR_DSR))
1262 		SET(ttybits, TIOCM_DSR);
1263 	if (ISSET(combits, MSR_RI | MSR_TERI))
1264 		SET(ttybits, TIOCM_RI);
1265 
1266 	if (ISSET(sc->sc_ier, IER_ERXRDY | IER_ETXRDY | IER_ERLS | IER_EMSC))
1267 		SET(ttybits, TIOCM_LE);
1268 
1269 	return (ttybits);
1270 }
1271 
1272 static u_char
1273 cflag2lcr(tcflag_t cflag)
1274 {
1275 	u_char lcr = 0;
1276 
1277 	switch (ISSET(cflag, CSIZE)) {
1278 	case CS5:
1279 		SET(lcr, LCR_5BITS);
1280 		break;
1281 	case CS6:
1282 		SET(lcr, LCR_6BITS);
1283 		break;
1284 	case CS7:
1285 		SET(lcr, LCR_7BITS);
1286 		break;
1287 	case CS8:
1288 		SET(lcr, LCR_8BITS);
1289 		break;
1290 	}
1291 	if (ISSET(cflag, PARENB)) {
1292 		SET(lcr, LCR_PENAB);
1293 		if (!ISSET(cflag, PARODD))
1294 			SET(lcr, LCR_PEVEN);
1295 	}
1296 	if (ISSET(cflag, CSTOPB))
1297 		SET(lcr, LCR_STOPB);
1298 
1299 	return (lcr);
1300 }
1301 
1302 int
1303 comparam(struct tty *tp, struct termios *t)
1304 {
1305 	struct com_softc *sc =
1306 	    device_lookup_private(&com_cd, COMUNIT(tp->t_dev));
1307 	int ospeed;
1308 	u_char lcr;
1309 
1310 	if (COM_ISALIVE(sc) == 0)
1311 		return (EIO);
1312 
1313 #ifdef COM_HAYESP
1314 	if (sc->sc_type == COM_TYPE_HAYESP) {
1315 		int prescaler, speed;
1316 
1317 		/*
1318 		 * Calculate UART clock prescaler.  It should be in
1319 		 * range of 0 .. 3.
1320 		 */
1321 		for (prescaler = 0, speed = t->c_ospeed; prescaler < 4;
1322 		    prescaler++, speed /= 2)
1323 			if ((ospeed = comspeed(speed, sc->sc_frequency,
1324 					       sc->sc_type)) > 0)
1325 				break;
1326 
1327 		if (prescaler == 4)
1328 			return (EINVAL);
1329 		sc->sc_prescaler = prescaler;
1330 	} else
1331 #endif
1332 	ospeed = comspeed(t->c_ospeed, sc->sc_frequency, sc->sc_type);
1333 
1334 	/* Check requested parameters. */
1335 	if (ospeed < 0)
1336 		return (EINVAL);
1337 	if (t->c_ispeed && t->c_ispeed != t->c_ospeed)
1338 		return (EINVAL);
1339 
1340 	/*
1341 	 * For the console, always force CLOCAL and !HUPCL, so that the port
1342 	 * is always active.
1343 	 */
1344 	if (ISSET(sc->sc_swflags, TIOCFLAG_SOFTCAR) ||
1345 	    ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
1346 		SET(t->c_cflag, CLOCAL);
1347 		CLR(t->c_cflag, HUPCL);
1348 	}
1349 
1350 	/*
1351 	 * If there were no changes, don't do anything.  This avoids dropping
1352 	 * input and improves performance when all we did was frob things like
1353 	 * VMIN and VTIME.
1354 	 */
1355 	if (tp->t_ospeed == t->c_ospeed &&
1356 	    tp->t_cflag == t->c_cflag)
1357 		return (0);
1358 
1359 	lcr = ISSET(sc->sc_lcr, LCR_SBREAK) | cflag2lcr(t->c_cflag);
1360 
1361 	mutex_spin_enter(&sc->sc_lock);
1362 
1363 	sc->sc_lcr = lcr;
1364 
1365 	/*
1366 	 * If we're not in a mode that assumes a connection is present, then
1367 	 * ignore carrier changes.
1368 	 */
1369 	if (ISSET(t->c_cflag, CLOCAL | MDMBUF))
1370 		sc->sc_msr_dcd = 0;
1371 	else
1372 		sc->sc_msr_dcd = MSR_DCD;
1373 	/*
1374 	 * Set the flow control pins depending on the current flow control
1375 	 * mode.
1376 	 */
1377 	if (ISSET(t->c_cflag, CRTSCTS)) {
1378 		sc->sc_mcr_dtr = MCR_DTR;
1379 		sc->sc_mcr_rts = MCR_RTS;
1380 		sc->sc_msr_cts = MSR_CTS;
1381 		if (ISSET(sc->sc_hwflags, COM_HW_AFE)) {
1382 			SET(sc->sc_mcr, MCR_AFE);
1383 		} else {
1384 			sc->sc_efr = EFR_AUTORTS | EFR_AUTOCTS;
1385 		}
1386 	} else if (ISSET(t->c_cflag, MDMBUF)) {
1387 		/*
1388 		 * For DTR/DCD flow control, make sure we don't toggle DTR for
1389 		 * carrier detection.
1390 		 */
1391 		sc->sc_mcr_dtr = 0;
1392 		sc->sc_mcr_rts = MCR_DTR;
1393 		sc->sc_msr_cts = MSR_DCD;
1394 		if (ISSET(sc->sc_hwflags, COM_HW_AFE)) {
1395 			CLR(sc->sc_mcr, MCR_AFE);
1396 		} else {
1397 			sc->sc_efr = 0;
1398 		}
1399 	} else {
1400 		/*
1401 		 * If no flow control, then always set RTS.  This will make
1402 		 * the other side happy if it mistakenly thinks we're doing
1403 		 * RTS/CTS flow control.
1404 		 */
1405 		sc->sc_mcr_dtr = MCR_DTR | MCR_RTS;
1406 		sc->sc_mcr_rts = 0;
1407 		sc->sc_msr_cts = 0;
1408 		if (ISSET(sc->sc_hwflags, COM_HW_AFE)) {
1409 			CLR(sc->sc_mcr, MCR_AFE);
1410 		} else {
1411 			sc->sc_efr = 0;
1412 		}
1413 		if (ISSET(sc->sc_mcr, MCR_DTR))
1414 			SET(sc->sc_mcr, MCR_RTS);
1415 		else
1416 			CLR(sc->sc_mcr, MCR_RTS);
1417 	}
1418 	sc->sc_msr_mask = sc->sc_msr_cts | sc->sc_msr_dcd;
1419 
1420 #if 0
1421 	if (ospeed == 0)
1422 		CLR(sc->sc_mcr, sc->sc_mcr_dtr);
1423 	else
1424 		SET(sc->sc_mcr, sc->sc_mcr_dtr);
1425 #endif
1426 
1427 	sc->sc_dlbl = ospeed;
1428 	sc->sc_dlbh = ospeed >> 8;
1429 
1430 	/*
1431 	 * Set the FIFO threshold based on the receive speed.
1432 	 *
1433 	 *  * If it's a low speed, it's probably a mouse or some other
1434 	 *    interactive device, so set the threshold low.
1435 	 *  * If it's a high speed, trim the trigger level down to prevent
1436 	 *    overflows.
1437 	 *  * Otherwise set it a bit higher.
1438 	 */
1439 	if (sc->sc_type == COM_TYPE_HAYESP)
1440 		sc->sc_fifo = FIFO_DMA_MODE | FIFO_ENABLE | FIFO_TRIGGER_8;
1441 	else if (ISSET(sc->sc_hwflags, COM_HW_FIFO)) {
1442 		if (t->c_ospeed <= 1200)
1443 			sc->sc_fifo = FIFO_ENABLE | FIFO_TRIGGER_1;
1444 		else if (t->c_ospeed <= 38400)
1445 			sc->sc_fifo = FIFO_ENABLE | FIFO_TRIGGER_8;
1446 		else
1447 			sc->sc_fifo = FIFO_ENABLE | FIFO_TRIGGER_4;
1448 	} else
1449 		sc->sc_fifo = 0;
1450 
1451 	/* And copy to tty. */
1452 	tp->t_ispeed = t->c_ospeed;
1453 	tp->t_ospeed = t->c_ospeed;
1454 	tp->t_cflag = t->c_cflag;
1455 
1456 	if (!sc->sc_heldchange) {
1457 		if (sc->sc_tx_busy) {
1458 			sc->sc_heldtbc = sc->sc_tbc;
1459 			sc->sc_tbc = 0;
1460 			sc->sc_heldchange = 1;
1461 		} else
1462 			com_loadchannelregs(sc);
1463 	}
1464 
1465 	if (!ISSET(t->c_cflag, CHWFLOW)) {
1466 		/* Disable the high water mark. */
1467 		sc->sc_r_hiwat = 0;
1468 		sc->sc_r_lowat = 0;
1469 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
1470 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1471 			com_schedrx(sc);
1472 		}
1473 		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED)) {
1474 			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED);
1475 			com_hwiflow(sc);
1476 		}
1477 	} else {
1478 		sc->sc_r_hiwat = com_rbuf_hiwat;
1479 		sc->sc_r_lowat = com_rbuf_lowat;
1480 	}
1481 
1482 	mutex_spin_exit(&sc->sc_lock);
1483 
1484 	/*
1485 	 * Update the tty layer's idea of the carrier bit, in case we changed
1486 	 * CLOCAL or MDMBUF.  We don't hang up here; we only do that by
1487 	 * explicit request.
1488 	 */
1489 	(void) (*tp->t_linesw->l_modem)(tp, ISSET(sc->sc_msr, MSR_DCD));
1490 
1491 #ifdef COM_DEBUG
1492 	if (com_debug)
1493 		comstatus(sc, "comparam ");
1494 #endif
1495 
1496 	if (!ISSET(t->c_cflag, CHWFLOW)) {
1497 		if (sc->sc_tx_stopped) {
1498 			sc->sc_tx_stopped = 0;
1499 			comstart(tp);
1500 		}
1501 	}
1502 
1503 	return (0);
1504 }
1505 
1506 void
1507 com_iflush(struct com_softc *sc)
1508 {
1509 	struct com_regs	*regsp = &sc->sc_regs;
1510 #ifdef DIAGNOSTIC
1511 	int reg;
1512 #endif
1513 	int timo;
1514 
1515 #ifdef DIAGNOSTIC
1516 	reg = 0xffff;
1517 #endif
1518 	timo = 50000;
1519 	/* flush any pending I/O */
1520 	while (ISSET(CSR_READ_1(regsp, COM_REG_LSR), LSR_RXRDY)
1521 	    && --timo)
1522 #ifdef DIAGNOSTIC
1523 		reg =
1524 #else
1525 		    (void)
1526 #endif
1527 		    CSR_READ_1(regsp, COM_REG_RXDATA);
1528 #ifdef DIAGNOSTIC
1529 	if (!timo)
1530 		aprint_error_dev(sc->sc_dev, "com_iflush timeout %02x\n", reg);
1531 #endif
1532 
1533 #ifdef COM_16750
1534 	uint8_t fifo;
1535 	/*
1536 	 * Reset all Rx/Tx FIFO, preserve current FIFO length.
1537 	 * This should prevent triggering busy interrupt while
1538 	 * manipulating divisors.
1539 	 */
1540 	fifo = CSR_READ_1(regsp, COM_REG_FIFO) & (FIFO_TRIGGER_1 |
1541 	    FIFO_TRIGGER_4 | FIFO_TRIGGER_8 | FIFO_TRIGGER_14);
1542 	CSR_WRITE_1(regsp, COM_REG_FIFO, fifo | FIFO_ENABLE | FIFO_RCV_RST |
1543 	    FIFO_XMT_RST);
1544 	delay(100);
1545 #endif
1546 }
1547 
1548 void
1549 com_loadchannelregs(struct com_softc *sc)
1550 {
1551 	struct com_regs *regsp = &sc->sc_regs;
1552 
1553 	/* XXXXX necessary? */
1554 	com_iflush(sc);
1555 
1556 	if (sc->sc_type == COM_TYPE_PXA2x0)
1557 		CSR_WRITE_1(regsp, COM_REG_IER, IER_EUART);
1558 	else
1559 		CSR_WRITE_1(regsp, COM_REG_IER, 0);
1560 
1561 	if (sc->sc_type == COM_TYPE_OMAP) {
1562 		/* disable before changing settings */
1563 		CSR_WRITE_1(regsp, COM_REG_MDR1, MDR1_MODE_DISABLE);
1564 	}
1565 
1566 	if (ISSET(sc->sc_hwflags, COM_HW_FLOW)) {
1567 		KASSERT(sc->sc_type != COM_TYPE_AU1x00);
1568 		KASSERT(sc->sc_type != COM_TYPE_16550_NOERS);
1569 		/* no EFR on alchemy */
1570 		CSR_WRITE_1(regsp, COM_REG_LCR, LCR_EERS);
1571 		CSR_WRITE_1(regsp, COM_REG_EFR, sc->sc_efr);
1572 	}
1573 	if (sc->sc_type == COM_TYPE_AU1x00) {
1574 		/* alchemy has single separate 16-bit clock divisor register */
1575 		CSR_WRITE_2(regsp, COM_REG_DLBL, sc->sc_dlbl +
1576 		    (sc->sc_dlbh << 8));
1577 	} else {
1578 		CSR_WRITE_1(regsp, COM_REG_LCR, sc->sc_lcr | LCR_DLAB);
1579 		CSR_WRITE_1(regsp, COM_REG_DLBL, sc->sc_dlbl);
1580 		CSR_WRITE_1(regsp, COM_REG_DLBH, sc->sc_dlbh);
1581 	}
1582 	CSR_WRITE_1(regsp, COM_REG_LCR, sc->sc_lcr);
1583 	CSR_WRITE_1(regsp, COM_REG_MCR, sc->sc_mcr_active = sc->sc_mcr);
1584 	CSR_WRITE_1(regsp, COM_REG_FIFO, sc->sc_fifo);
1585 #ifdef COM_HAYESP
1586 	if (sc->sc_type == COM_TYPE_HAYESP) {
1587 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD1,
1588 		    HAYESP_SETPRESCALER);
1589 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
1590 		    sc->sc_prescaler);
1591 	}
1592 #endif
1593 	if (sc->sc_type == COM_TYPE_OMAP) {
1594 		/* setup the fifos.  the FCR value is not used as long
1595 		   as SCR[6] and SCR[7] are 0, which they are at reset
1596 		   and we never touch the SCR register */
1597 		uint8_t rx_fifo_trig = 40;
1598 		uint8_t tx_fifo_trig = 60;
1599 		uint8_t rx_start = 8;
1600 		uint8_t rx_halt = 60;
1601 		uint8_t tlr_value = ((rx_fifo_trig>>2) << 4) | (tx_fifo_trig>>2);
1602 		uint8_t tcr_value = ((rx_start>>2) << 4) | (rx_halt>>2);
1603 
1604 		/* enable access to TCR & TLR */
1605 		CSR_WRITE_1(regsp, COM_REG_MCR, sc->sc_mcr | MCR_TCR_TLR);
1606 
1607 		/* write tcr and tlr values */
1608 		CSR_WRITE_1(regsp, COM_REG_TLR, tlr_value);
1609 		CSR_WRITE_1(regsp, COM_REG_TCR, tcr_value);
1610 
1611 		/* disable access to TCR & TLR */
1612 		CSR_WRITE_1(regsp, COM_REG_MCR, sc->sc_mcr);
1613 
1614 		/* enable again, but mode is based on speed */
1615 		if (sc->sc_tty->t_termios.c_ospeed > 230400) {
1616 			CSR_WRITE_1(regsp, COM_REG_MDR1, MDR1_MODE_UART_13X);
1617 		} else {
1618 			CSR_WRITE_1(regsp, COM_REG_MDR1, MDR1_MODE_UART_16X);
1619 		}
1620 	}
1621 
1622 	CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
1623 }
1624 
1625 int
1626 comhwiflow(struct tty *tp, int block)
1627 {
1628 	struct com_softc *sc =
1629 	    device_lookup_private(&com_cd, COMUNIT(tp->t_dev));
1630 
1631 	if (COM_ISALIVE(sc) == 0)
1632 		return (0);
1633 
1634 	if (sc->sc_mcr_rts == 0)
1635 		return (0);
1636 
1637 	mutex_spin_enter(&sc->sc_lock);
1638 
1639 	if (block) {
1640 		if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1641 			SET(sc->sc_rx_flags, RX_TTY_BLOCKED);
1642 			com_hwiflow(sc);
1643 		}
1644 	} else {
1645 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
1646 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1647 			com_schedrx(sc);
1648 		}
1649 		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1650 			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED);
1651 			com_hwiflow(sc);
1652 		}
1653 	}
1654 
1655 	mutex_spin_exit(&sc->sc_lock);
1656 	return (1);
1657 }
1658 
1659 /*
1660  * (un)block input via hw flowcontrol
1661  */
1662 void
1663 com_hwiflow(struct com_softc *sc)
1664 {
1665 	struct com_regs *regsp= &sc->sc_regs;
1666 
1667 	if (sc->sc_mcr_rts == 0)
1668 		return;
1669 
1670 	if (ISSET(sc->sc_rx_flags, RX_ANY_BLOCK)) {
1671 		CLR(sc->sc_mcr, sc->sc_mcr_rts);
1672 		CLR(sc->sc_mcr_active, sc->sc_mcr_rts);
1673 	} else {
1674 		SET(sc->sc_mcr, sc->sc_mcr_rts);
1675 		SET(sc->sc_mcr_active, sc->sc_mcr_rts);
1676 	}
1677 	CSR_WRITE_1(regsp, COM_REG_MCR, sc->sc_mcr_active);
1678 }
1679 
1680 
1681 void
1682 comstart(struct tty *tp)
1683 {
1684 	struct com_softc *sc =
1685 	    device_lookup_private(&com_cd, COMUNIT(tp->t_dev));
1686 	struct com_regs *regsp = &sc->sc_regs;
1687 	int s;
1688 
1689 	if (COM_ISALIVE(sc) == 0)
1690 		return;
1691 
1692 	s = spltty();
1693 	if (ISSET(tp->t_state, TS_BUSY | TS_TIMEOUT | TS_TTSTOP))
1694 		goto out;
1695 	if (sc->sc_tx_stopped)
1696 		goto out;
1697 	if (!ttypull(tp))
1698 		goto out;
1699 
1700 	/* Grab the first contiguous region of buffer space. */
1701 	{
1702 		u_char *tba;
1703 		int tbc;
1704 
1705 		tba = tp->t_outq.c_cf;
1706 		tbc = ndqb(&tp->t_outq, 0);
1707 
1708 		mutex_spin_enter(&sc->sc_lock);
1709 
1710 		sc->sc_tba = tba;
1711 		sc->sc_tbc = tbc;
1712 	}
1713 
1714 	SET(tp->t_state, TS_BUSY);
1715 	sc->sc_tx_busy = 1;
1716 
1717 	/* Enable transmit completion interrupts if necessary. */
1718 	if (!ISSET(sc->sc_ier, IER_ETXRDY)) {
1719 		SET(sc->sc_ier, IER_ETXRDY);
1720 		CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
1721 	}
1722 
1723 	/* Output the first chunk of the contiguous buffer. */
1724 	if (!ISSET(sc->sc_hwflags, COM_HW_NO_TXPRELOAD)) {
1725 		u_int n;
1726 
1727 		n = sc->sc_tbc;
1728 		if (n > sc->sc_fifolen)
1729 			n = sc->sc_fifolen;
1730 		CSR_WRITE_MULTI(regsp, COM_REG_TXDATA, sc->sc_tba, n);
1731 		sc->sc_tbc -= n;
1732 		sc->sc_tba += n;
1733 	}
1734 
1735 	mutex_spin_exit(&sc->sc_lock);
1736 out:
1737 	splx(s);
1738 	return;
1739 }
1740 
1741 /*
1742  * Stop output on a line.
1743  */
1744 void
1745 comstop(struct tty *tp, int flag)
1746 {
1747 	struct com_softc *sc =
1748 	    device_lookup_private(&com_cd, COMUNIT(tp->t_dev));
1749 
1750 	mutex_spin_enter(&sc->sc_lock);
1751 	if (ISSET(tp->t_state, TS_BUSY)) {
1752 		/* Stop transmitting at the next chunk. */
1753 		sc->sc_tbc = 0;
1754 		sc->sc_heldtbc = 0;
1755 		if (!ISSET(tp->t_state, TS_TTSTOP))
1756 			SET(tp->t_state, TS_FLUSH);
1757 	}
1758 	mutex_spin_exit(&sc->sc_lock);
1759 }
1760 
1761 void
1762 comdiag(void *arg)
1763 {
1764 	struct com_softc *sc = arg;
1765 	int overflows, floods;
1766 
1767 	mutex_spin_enter(&sc->sc_lock);
1768 	overflows = sc->sc_overflows;
1769 	sc->sc_overflows = 0;
1770 	floods = sc->sc_floods;
1771 	sc->sc_floods = 0;
1772 	sc->sc_errors = 0;
1773 	mutex_spin_exit(&sc->sc_lock);
1774 
1775 	log(LOG_WARNING, "%s: %d silo overflow%s, %d ibuf flood%s\n",
1776 	    device_xname(sc->sc_dev),
1777 	    overflows, overflows == 1 ? "" : "s",
1778 	    floods, floods == 1 ? "" : "s");
1779 }
1780 
1781 integrate void
1782 com_rxsoft(struct com_softc *sc, struct tty *tp)
1783 {
1784 	int (*rint)(int, struct tty *) = tp->t_linesw->l_rint;
1785 	u_char *get, *end;
1786 	u_int cc, scc;
1787 	u_char lsr;
1788 	int code;
1789 
1790 	end = sc->sc_ebuf;
1791 	get = sc->sc_rbget;
1792 	scc = cc = com_rbuf_size - sc->sc_rbavail;
1793 
1794 	if (cc == com_rbuf_size) {
1795 		sc->sc_floods++;
1796 		if (sc->sc_errors++ == 0)
1797 			callout_reset(&sc->sc_diag_callout, 60 * hz,
1798 			    comdiag, sc);
1799 	}
1800 
1801 	/* If not yet open, drop the entire buffer content here */
1802 	if (!ISSET(tp->t_state, TS_ISOPEN)) {
1803 		get += cc << 1;
1804 		if (get >= end)
1805 			get -= com_rbuf_size << 1;
1806 		cc = 0;
1807 	}
1808 	while (cc) {
1809 		code = get[0];
1810 		lsr = get[1];
1811 		if (ISSET(lsr, LSR_OE | LSR_BI | LSR_FE | LSR_PE)) {
1812 			if (ISSET(lsr, LSR_OE)) {
1813 				sc->sc_overflows++;
1814 				if (sc->sc_errors++ == 0)
1815 					callout_reset(&sc->sc_diag_callout,
1816 					    60 * hz, comdiag, sc);
1817 			}
1818 			if (ISSET(lsr, LSR_BI | LSR_FE))
1819 				SET(code, TTY_FE);
1820 			if (ISSET(lsr, LSR_PE))
1821 				SET(code, TTY_PE);
1822 		}
1823 		if ((*rint)(code, tp) == -1) {
1824 			/*
1825 			 * The line discipline's buffer is out of space.
1826 			 */
1827 			if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1828 				/*
1829 				 * We're either not using flow control, or the
1830 				 * line discipline didn't tell us to block for
1831 				 * some reason.  Either way, we have no way to
1832 				 * know when there's more space available, so
1833 				 * just drop the rest of the data.
1834 				 */
1835 				get += cc << 1;
1836 				if (get >= end)
1837 					get -= com_rbuf_size << 1;
1838 				cc = 0;
1839 			} else {
1840 				/*
1841 				 * Don't schedule any more receive processing
1842 				 * until the line discipline tells us there's
1843 				 * space available (through comhwiflow()).
1844 				 * Leave the rest of the data in the input
1845 				 * buffer.
1846 				 */
1847 				SET(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1848 			}
1849 			break;
1850 		}
1851 		get += 2;
1852 		if (get >= end)
1853 			get = sc->sc_rbuf;
1854 		cc--;
1855 	}
1856 
1857 	if (cc != scc) {
1858 		sc->sc_rbget = get;
1859 		mutex_spin_enter(&sc->sc_lock);
1860 
1861 		cc = sc->sc_rbavail += scc - cc;
1862 		/* Buffers should be ok again, release possible block. */
1863 		if (cc >= sc->sc_r_lowat) {
1864 			if (ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
1865 				CLR(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
1866 				SET(sc->sc_ier, IER_ERXRDY);
1867 #ifdef COM_PXA2X0
1868 				if (sc->sc_type == COM_TYPE_PXA2x0)
1869 					SET(sc->sc_ier, IER_ERXTOUT);
1870 #endif
1871 				CSR_WRITE_1(&sc->sc_regs, COM_REG_IER, sc->sc_ier);
1872 			}
1873 			if (ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED)) {
1874 				CLR(sc->sc_rx_flags, RX_IBUF_BLOCKED);
1875 				com_hwiflow(sc);
1876 			}
1877 		}
1878 		mutex_spin_exit(&sc->sc_lock);
1879 	}
1880 }
1881 
1882 integrate void
1883 com_txsoft(struct com_softc *sc, struct tty *tp)
1884 {
1885 
1886 	CLR(tp->t_state, TS_BUSY);
1887 	if (ISSET(tp->t_state, TS_FLUSH))
1888 		CLR(tp->t_state, TS_FLUSH);
1889 	else
1890 		ndflush(&tp->t_outq, (int)(sc->sc_tba - tp->t_outq.c_cf));
1891 	(*tp->t_linesw->l_start)(tp);
1892 }
1893 
1894 integrate void
1895 com_stsoft(struct com_softc *sc, struct tty *tp)
1896 {
1897 	u_char msr, delta;
1898 
1899 	mutex_spin_enter(&sc->sc_lock);
1900 	msr = sc->sc_msr;
1901 	delta = sc->sc_msr_delta;
1902 	sc->sc_msr_delta = 0;
1903 	mutex_spin_exit(&sc->sc_lock);
1904 
1905 	if (ISSET(delta, sc->sc_msr_dcd)) {
1906 		/*
1907 		 * Inform the tty layer that carrier detect changed.
1908 		 */
1909 		(void) (*tp->t_linesw->l_modem)(tp, ISSET(msr, MSR_DCD));
1910 	}
1911 
1912 	if (ISSET(delta, sc->sc_msr_cts)) {
1913 		/* Block or unblock output according to flow control. */
1914 		if (ISSET(msr, sc->sc_msr_cts)) {
1915 			sc->sc_tx_stopped = 0;
1916 			(*tp->t_linesw->l_start)(tp);
1917 		} else {
1918 			sc->sc_tx_stopped = 1;
1919 		}
1920 	}
1921 
1922 #ifdef COM_DEBUG
1923 	if (com_debug)
1924 		comstatus(sc, "com_stsoft");
1925 #endif
1926 }
1927 
1928 void
1929 comsoft(void *arg)
1930 {
1931 	struct com_softc *sc = arg;
1932 	struct tty *tp;
1933 
1934 	if (COM_ISALIVE(sc) == 0)
1935 		return;
1936 
1937 	tp = sc->sc_tty;
1938 
1939 	if (sc->sc_rx_ready) {
1940 		sc->sc_rx_ready = 0;
1941 		com_rxsoft(sc, tp);
1942 	}
1943 
1944 	if (sc->sc_st_check) {
1945 		sc->sc_st_check = 0;
1946 		com_stsoft(sc, tp);
1947 	}
1948 
1949 	if (sc->sc_tx_done) {
1950 		sc->sc_tx_done = 0;
1951 		com_txsoft(sc, tp);
1952 	}
1953 }
1954 
1955 int
1956 comintr(void *arg)
1957 {
1958 	struct com_softc *sc = arg;
1959 	struct com_regs *regsp = &sc->sc_regs;
1960 
1961 	u_char *put, *end;
1962 	u_int cc;
1963 	u_char lsr, iir;
1964 
1965 	if (COM_ISALIVE(sc) == 0)
1966 		return (0);
1967 
1968 	KASSERT(regsp != NULL);
1969 
1970 	mutex_spin_enter(&sc->sc_lock);
1971 	iir = CSR_READ_1(regsp, COM_REG_IIR);
1972 
1973 	/* Handle ns16750-specific busy interrupt. */
1974 #ifdef COM_16750
1975 	int timeout;
1976 	if ((iir & IIR_BUSY) == IIR_BUSY) {
1977 		for (timeout = 10000;
1978 		    (CSR_READ_1(regsp, COM_REG_USR) & 0x1) != 0; timeout--)
1979 			if (timeout <= 0) {
1980 				aprint_error_dev(sc->sc_dev,
1981 				    "timeout while waiting for BUSY interrupt "
1982 				    "acknowledge\n");
1983 				mutex_spin_exit(&sc->sc_lock);
1984 				return (0);
1985 			}
1986 
1987 		CSR_WRITE_1(regsp, COM_REG_LCR, sc->sc_lcr);
1988 		iir = CSR_READ_1(regsp, COM_REG_IIR);
1989 	}
1990 #endif /* COM_16750 */
1991 
1992 
1993 	if (ISSET(iir, IIR_NOPEND)) {
1994 		mutex_spin_exit(&sc->sc_lock);
1995 		return (0);
1996 	}
1997 
1998 	end = sc->sc_ebuf;
1999 	put = sc->sc_rbput;
2000 	cc = sc->sc_rbavail;
2001 
2002 again:	do {
2003 		u_char	msr, delta;
2004 
2005 		lsr = CSR_READ_1(regsp, COM_REG_LSR);
2006 		if (ISSET(lsr, LSR_BI)) {
2007 			int cn_trapped = 0; /* see above: cn_trap() */
2008 
2009 			cn_check_magic(sc->sc_tty->t_dev,
2010 				       CNC_BREAK, com_cnm_state);
2011 			if (cn_trapped)
2012 				continue;
2013 #if defined(KGDB) && !defined(DDB)
2014 			if (ISSET(sc->sc_hwflags, COM_HW_KGDB)) {
2015 				kgdb_connect(1);
2016 				continue;
2017 			}
2018 #endif
2019 		}
2020 
2021 		if (ISSET(lsr, LSR_RCV_MASK) &&
2022 		    !ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
2023 			while (cc > 0) {
2024 				int cn_trapped = 0;
2025 				put[0] = CSR_READ_1(regsp, COM_REG_RXDATA);
2026 				put[1] = lsr;
2027 				cn_check_magic(sc->sc_tty->t_dev,
2028 					       put[0], com_cnm_state);
2029 				if (cn_trapped)
2030 					goto next;
2031 				put += 2;
2032 				if (put >= end)
2033 					put = sc->sc_rbuf;
2034 				cc--;
2035 			next:
2036 				lsr = CSR_READ_1(regsp, COM_REG_LSR);
2037 				if (!ISSET(lsr, LSR_RCV_MASK))
2038 					break;
2039 			}
2040 
2041 			/*
2042 			 * Current string of incoming characters ended because
2043 			 * no more data was available or we ran out of space.
2044 			 * Schedule a receive event if any data was received.
2045 			 * If we're out of space, turn off receive interrupts.
2046 			 */
2047 			sc->sc_rbput = put;
2048 			sc->sc_rbavail = cc;
2049 			if (!ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED))
2050 				sc->sc_rx_ready = 1;
2051 
2052 			/*
2053 			 * See if we are in danger of overflowing a buffer. If
2054 			 * so, use hardware flow control to ease the pressure.
2055 			 */
2056 			if (!ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED) &&
2057 			    cc < sc->sc_r_hiwat) {
2058 				SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
2059 				com_hwiflow(sc);
2060 			}
2061 
2062 			/*
2063 			 * If we're out of space, disable receive interrupts
2064 			 * until the queue has drained a bit.
2065 			 */
2066 			if (!cc) {
2067 				SET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
2068 #ifdef COM_PXA2X0
2069 				if (sc->sc_type == COM_TYPE_PXA2x0)
2070 					CLR(sc->sc_ier, IER_ERXRDY|IER_ERXTOUT);
2071 				else
2072 #endif
2073 					CLR(sc->sc_ier, IER_ERXRDY);
2074 				CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
2075 			}
2076 		} else {
2077 			if ((iir & (IIR_RXRDY|IIR_TXRDY)) == IIR_RXRDY) {
2078 				(void) CSR_READ_1(regsp, COM_REG_RXDATA);
2079 				continue;
2080 			}
2081 		}
2082 
2083 		msr = CSR_READ_1(regsp, COM_REG_MSR);
2084 		delta = msr ^ sc->sc_msr;
2085 		sc->sc_msr = msr;
2086 		if ((sc->sc_pps_state.ppsparam.mode & PPS_CAPTUREBOTH) &&
2087 		    (delta & MSR_DCD)) {
2088 			mutex_spin_enter(&timecounter_lock);
2089 			pps_capture(&sc->sc_pps_state);
2090 			pps_event(&sc->sc_pps_state,
2091 			    (msr & MSR_DCD) ?
2092 			    PPS_CAPTUREASSERT :
2093 			    PPS_CAPTURECLEAR);
2094 			mutex_spin_exit(&timecounter_lock);
2095 		}
2096 
2097 		/*
2098 		 * Process normal status changes
2099 		 */
2100 		if (ISSET(delta, sc->sc_msr_mask)) {
2101 			SET(sc->sc_msr_delta, delta);
2102 
2103 			/*
2104 			 * Stop output immediately if we lose the output
2105 			 * flow control signal or carrier detect.
2106 			 */
2107 			if (ISSET(~msr, sc->sc_msr_mask)) {
2108 				sc->sc_tbc = 0;
2109 				sc->sc_heldtbc = 0;
2110 #ifdef COM_DEBUG
2111 				if (com_debug)
2112 					comstatus(sc, "comintr  ");
2113 #endif
2114 			}
2115 
2116 			sc->sc_st_check = 1;
2117 		}
2118 	} while (!ISSET((iir =
2119 	    CSR_READ_1(regsp, COM_REG_IIR)), IIR_NOPEND) &&
2120 	    /*
2121 	     * Since some device (e.g., ST16C1550) doesn't clear IIR_TXRDY
2122 	     * by IIR read, so we can't do this way: `process all interrupts,
2123 	     * then do TX if possible'.
2124 	     */
2125 	    (iir & IIR_IMASK) != IIR_TXRDY);
2126 
2127 	/*
2128 	 * Read LSR again, since there may be an interrupt between
2129 	 * the last LSR read and IIR read above.
2130 	 */
2131 	lsr = CSR_READ_1(regsp, COM_REG_LSR);
2132 
2133 	/*
2134 	 * See if data can be transmitted as well.
2135 	 * Schedule tx done event if no data left
2136 	 * and tty was marked busy.
2137 	 */
2138 	if (ISSET(lsr, LSR_TXRDY)) {
2139 		/*
2140 		 * If we've delayed a parameter change, do it now, and restart
2141 		 * output.
2142 		 */
2143 		if (sc->sc_heldchange) {
2144 			com_loadchannelregs(sc);
2145 			sc->sc_heldchange = 0;
2146 			sc->sc_tbc = sc->sc_heldtbc;
2147 			sc->sc_heldtbc = 0;
2148 		}
2149 
2150 		/* Output the next chunk of the contiguous buffer, if any. */
2151 		if (sc->sc_tbc > 0) {
2152 			u_int n;
2153 
2154 			n = sc->sc_tbc;
2155 			if (n > sc->sc_fifolen)
2156 				n = sc->sc_fifolen;
2157 			CSR_WRITE_MULTI(regsp, COM_REG_TXDATA, sc->sc_tba, n);
2158 			sc->sc_tbc -= n;
2159 			sc->sc_tba += n;
2160 		} else {
2161 			/* Disable transmit completion interrupts if necessary. */
2162 			if (ISSET(sc->sc_ier, IER_ETXRDY)) {
2163 				CLR(sc->sc_ier, IER_ETXRDY);
2164 				CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
2165 			}
2166 			if (sc->sc_tx_busy) {
2167 				sc->sc_tx_busy = 0;
2168 				sc->sc_tx_done = 1;
2169 			}
2170 		}
2171 	}
2172 
2173 	if (!ISSET((iir = CSR_READ_1(regsp, COM_REG_IIR)), IIR_NOPEND))
2174 		goto again;
2175 
2176 	mutex_spin_exit(&sc->sc_lock);
2177 
2178 	/* Wake up the poller. */
2179 	softint_schedule(sc->sc_si);
2180 
2181 #ifdef RND_COM
2182 	rnd_add_uint32(&sc->rnd_source, iir | lsr);
2183 #endif
2184 
2185 	return (1);
2186 }
2187 
2188 /*
2189  * The following functions are polled getc and putc routines, shared
2190  * by the console and kgdb glue.
2191  *
2192  * The read-ahead code is so that you can detect pending in-band
2193  * cn_magic in polled mode while doing output rather than having to
2194  * wait until the kernel decides it needs input.
2195  */
2196 
2197 #define MAX_READAHEAD	20
2198 static int com_readahead[MAX_READAHEAD];
2199 static int com_readaheadcount = 0;
2200 
2201 int
2202 com_common_getc(dev_t dev, struct com_regs *regsp)
2203 {
2204 	int s = splserial();
2205 	u_char stat, c;
2206 
2207 	/* got a character from reading things earlier */
2208 	if (com_readaheadcount > 0) {
2209 		int i;
2210 
2211 		c = com_readahead[0];
2212 		for (i = 1; i < com_readaheadcount; i++) {
2213 			com_readahead[i-1] = com_readahead[i];
2214 		}
2215 		com_readaheadcount--;
2216 		splx(s);
2217 		return (c);
2218 	}
2219 
2220 	/* don't block until a character becomes available */
2221 	if (!ISSET(stat = CSR_READ_1(regsp, COM_REG_LSR), LSR_RXRDY)) {
2222 		splx(s);
2223 		return -1;
2224 	}
2225 
2226 	c = CSR_READ_1(regsp, COM_REG_RXDATA);
2227 	stat = CSR_READ_1(regsp, COM_REG_IIR);
2228 	{
2229 		int cn_trapped = 0;	/* required by cn_trap, see above */
2230 #ifdef DDB
2231 		extern int db_active;
2232 		if (!db_active)
2233 #endif
2234 			cn_check_magic(dev, c, com_cnm_state);
2235 	}
2236 	splx(s);
2237 	return (c);
2238 }
2239 
2240 static void
2241 com_common_putc(dev_t dev, struct com_regs *regsp, int c)
2242 {
2243 	int s = splserial();
2244 	int cin, stat, timo;
2245 
2246 	if (com_readaheadcount < MAX_READAHEAD
2247 	     && ISSET(stat = CSR_READ_1(regsp, COM_REG_LSR), LSR_RXRDY)) {
2248 		int cn_trapped = 0;
2249 		cin = CSR_READ_1(regsp, COM_REG_RXDATA);
2250 		stat = CSR_READ_1(regsp, COM_REG_IIR);
2251 		cn_check_magic(dev, cin, com_cnm_state);
2252 		com_readahead[com_readaheadcount++] = cin;
2253 	}
2254 
2255 	/* wait for any pending transmission to finish */
2256 	timo = 150000;
2257 	while (!ISSET(CSR_READ_1(regsp, COM_REG_LSR), LSR_TXRDY) && --timo)
2258 		continue;
2259 
2260 	CSR_WRITE_1(regsp, COM_REG_TXDATA, c);
2261 	COM_BARRIER(regsp, BR | BW);
2262 
2263 	splx(s);
2264 }
2265 
2266 /*
2267  * Initialize UART for use as console or KGDB line.
2268  */
2269 int
2270 cominit(struct com_regs *regsp, int rate, int frequency, int type,
2271     tcflag_t cflag)
2272 {
2273 
2274 	if (bus_space_map(regsp->cr_iot, regsp->cr_iobase, regsp->cr_nports, 0,
2275 		&regsp->cr_ioh))
2276 		return (ENOMEM); /* ??? */
2277 
2278 	if (type == COM_TYPE_OMAP) {
2279 		/* disable before changing settings */
2280 		CSR_WRITE_1(regsp, COM_REG_MDR1, MDR1_MODE_DISABLE);
2281 	}
2282 
2283 	rate = comspeed(rate, frequency, type);
2284 	if (__predict_true(rate != -1)) {
2285 		if (type == COM_TYPE_AU1x00) {
2286 			CSR_WRITE_2(regsp, COM_REG_DLBL, rate);
2287 		} else {
2288 			/* no EFR on alchemy */
2289 			if (type != COM_TYPE_16550_NOERS) {
2290 				CSR_WRITE_1(regsp, COM_REG_LCR, LCR_EERS);
2291 				CSR_WRITE_1(regsp, COM_REG_EFR, 0);
2292 			}
2293 			CSR_WRITE_1(regsp, COM_REG_LCR, LCR_DLAB);
2294 			CSR_WRITE_1(regsp, COM_REG_DLBL, rate & 0xff);
2295 			CSR_WRITE_1(regsp, COM_REG_DLBH, rate >> 8);
2296 		}
2297 	}
2298 	CSR_WRITE_1(regsp, COM_REG_LCR, cflag2lcr(cflag));
2299 	CSR_WRITE_1(regsp, COM_REG_MCR, MCR_DTR | MCR_RTS);
2300 	CSR_WRITE_1(regsp, COM_REG_FIFO,
2301 	    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_1);
2302 
2303 	if (type == COM_TYPE_OMAP) {
2304 		/* setup the fifos.  the FCR value is not used as long
2305 		   as SCR[6] and SCR[7] are 0, which they are at reset
2306 		   and we never touch the SCR register */
2307 		uint8_t rx_fifo_trig = 40;
2308 		uint8_t tx_fifo_trig = 60;
2309 		uint8_t rx_start = 8;
2310 		uint8_t rx_halt = 60;
2311 		uint8_t tlr_value = ((rx_fifo_trig>>2) << 4) | (tx_fifo_trig>>2);
2312 		uint8_t tcr_value = ((rx_start>>2) << 4) | (rx_halt>>2);
2313 
2314 		/* enable access to TCR & TLR */
2315 		CSR_WRITE_1(regsp, COM_REG_MCR, MCR_DTR | MCR_RTS | MCR_TCR_TLR);
2316 
2317 		/* write tcr and tlr values */
2318 		CSR_WRITE_1(regsp, COM_REG_TLR, tlr_value);
2319 		CSR_WRITE_1(regsp, COM_REG_TCR, tcr_value);
2320 
2321 		/* disable access to TCR & TLR */
2322 		CSR_WRITE_1(regsp, COM_REG_MCR, MCR_DTR | MCR_RTS);
2323 
2324 		/* enable again, but mode is based on speed */
2325 		if (rate > 230400) {
2326 			CSR_WRITE_1(regsp, COM_REG_MDR1, MDR1_MODE_UART_13X);
2327 		} else {
2328 			CSR_WRITE_1(regsp, COM_REG_MDR1, MDR1_MODE_UART_16X);
2329 		}
2330 	}
2331 
2332 #ifdef COM_PXA2X0
2333 	if (type == COM_TYPE_PXA2x0)
2334 		CSR_WRITE_1(regsp, COM_REG_IER, IER_EUART);
2335 	else
2336 #endif
2337 		CSR_WRITE_1(regsp, COM_REG_IER, 0);
2338 
2339 	return (0);
2340 }
2341 
2342 int
2343 comcnattach1(struct com_regs *regsp, int rate, int frequency, int type,
2344     tcflag_t cflag)
2345 {
2346 	int res;
2347 
2348 	comcons_info.regs = *regsp;
2349 
2350 	res = cominit(&comcons_info.regs, rate, frequency, type, cflag);
2351 	if (res)
2352 		return (res);
2353 
2354 	cn_tab = &comcons;
2355 	cn_init_magic(&com_cnm_state);
2356 	cn_set_magic("\047\001"); /* default magic is BREAK */
2357 
2358 	comcons_info.frequency = frequency;
2359 	comcons_info.type = type;
2360 	comcons_info.rate = rate;
2361 	comcons_info.cflag = cflag;
2362 
2363 	return (0);
2364 }
2365 
2366 int
2367 comcnattach(bus_space_tag_t iot, bus_addr_t iobase, int rate, int frequency,
2368     int type, tcflag_t cflag)
2369 {
2370 	struct com_regs	regs;
2371 
2372 	memset(&regs, 0, sizeof regs);
2373 	regs.cr_iot = iot;
2374 	regs.cr_iobase = iobase;
2375 	regs.cr_nports = COM_NPORTS;
2376 #ifdef	COM_REGMAP
2377 	memcpy(regs.cr_map, com_std_map, sizeof (regs.cr_map));
2378 #endif
2379 
2380 	return comcnattach1(&regs, rate, frequency, type, cflag);
2381 }
2382 
2383 static int
2384 comcnreattach(void)
2385 {
2386 	return comcnattach1(&comcons_info.regs, comcons_info.rate,
2387 	    comcons_info.frequency, comcons_info.type, comcons_info.cflag);
2388 }
2389 
2390 int
2391 comcngetc(dev_t dev)
2392 {
2393 
2394 	return (com_common_getc(dev, &comcons_info.regs));
2395 }
2396 
2397 /*
2398  * Console kernel output character routine.
2399  */
2400 void
2401 comcnputc(dev_t dev, int c)
2402 {
2403 
2404 	com_common_putc(dev, &comcons_info.regs, c);
2405 }
2406 
2407 void
2408 comcnpollc(dev_t dev, int on)
2409 {
2410 
2411 	com_readaheadcount = 0;
2412 }
2413 
2414 #ifdef KGDB
2415 int
2416 com_kgdb_attach1(struct com_regs *regsp, int rate, int frequency, int type,
2417     tcflag_t cflag)
2418 {
2419 	int res;
2420 
2421 	if (bus_space_is_equal(regsp->cr_iot, comcons_info.regs.cr_iot) &&
2422 	    regsp->cr_iobase == comcons_info.regs.cr_iobase) {
2423 #if !defined(DDB)
2424 		return (EBUSY); /* cannot share with console */
2425 #else
2426 		comkgdbregs = *regsp;
2427 		comkgdbregs.cr_ioh = comcons_info.regs.cr_ioh;
2428 #endif
2429 	} else {
2430 		comkgdbregs = *regsp;
2431 		res = cominit(&comkgdbregs, rate, frequency, type, cflag);
2432 		if (res)
2433 			return (res);
2434 
2435 		/*
2436 		 * XXXfvdl this shouldn't be needed, but the cn_magic goo
2437 		 * expects this to be initialized
2438 		 */
2439 		cn_init_magic(&com_cnm_state);
2440 		cn_set_magic("\047\001");
2441 	}
2442 
2443 	kgdb_attach(com_kgdb_getc, com_kgdb_putc, NULL);
2444 	kgdb_dev = 123; /* unneeded, only to satisfy some tests */
2445 
2446 	return (0);
2447 }
2448 
2449 int
2450 com_kgdb_attach(bus_space_tag_t iot, bus_addr_t iobase, int rate,
2451     int frequency, int type, tcflag_t cflag)
2452 {
2453 	struct com_regs regs;
2454 
2455 	regs.cr_iot = iot;
2456 	regs.cr_nports = COM_NPORTS;
2457 	regs.cr_iobase = iobase;
2458 #ifdef COM_REGMAP
2459 	memcpy(regs.cr_map, com_std_map, sizeof (regs.cr_map));
2460 #endif
2461 
2462 	return com_kgdb_attach1(&regs, rate, frequency, type, cflag);
2463 }
2464 
2465 /* ARGSUSED */
2466 int
2467 com_kgdb_getc(void *arg)
2468 {
2469 
2470 	return (com_common_getc(NODEV, &comkgdbregs));
2471 }
2472 
2473 /* ARGSUSED */
2474 void
2475 com_kgdb_putc(void *arg, int c)
2476 {
2477 
2478 	com_common_putc(NODEV, &comkgdbregs, c);
2479 }
2480 #endif /* KGDB */
2481 
2482 /* helper function to identify the com ports used by
2483  console or KGDB (and not yet autoconf attached) */
2484 int
2485 com_is_console(bus_space_tag_t iot, bus_addr_t iobase, bus_space_handle_t *ioh)
2486 {
2487 	bus_space_handle_t help;
2488 
2489 	if (!comconsattached &&
2490 	    bus_space_is_equal(iot, comcons_info.regs.cr_iot) &&
2491 	    iobase == comcons_info.regs.cr_iobase)
2492 		help = comcons_info.regs.cr_ioh;
2493 #ifdef KGDB
2494 	else if (!com_kgdb_attached &&
2495 	    bus_space_is_equal(iot, comkgdbregs.cr_iot) &&
2496 	    iobase == comkgdbregs.cr_iobase)
2497 		help = comkgdbregs.cr_ioh;
2498 #endif
2499 	else
2500 		return (0);
2501 
2502 	if (ioh)
2503 		*ioh = help;
2504 	return (1);
2505 }
2506 
2507 /*
2508  * this routine exists to serve as a shutdown hook for systems that
2509  * have firmware which doesn't interact properly with a com device in
2510  * FIFO mode.
2511  */
2512 bool
2513 com_cleanup(device_t self, int how)
2514 {
2515 	struct com_softc *sc = device_private(self);
2516 
2517 	if (ISSET(sc->sc_hwflags, COM_HW_FIFO))
2518 		CSR_WRITE_1(&sc->sc_regs, COM_REG_FIFO, 0);
2519 
2520 	return true;
2521 }
2522 
2523 bool
2524 com_suspend(device_t self, const pmf_qual_t *qual)
2525 {
2526 	struct com_softc *sc = device_private(self);
2527 
2528 #if 0
2529 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE) && cn_tab == &comcons)
2530 		cn_tab = &comcons_suspend;
2531 #endif
2532 
2533 	CSR_WRITE_1(&sc->sc_regs, COM_REG_IER, 0);
2534 	(void)CSR_READ_1(&sc->sc_regs, COM_REG_IIR);
2535 
2536 	return true;
2537 }
2538 
2539 bool
2540 com_resume(device_t self, const pmf_qual_t *qual)
2541 {
2542 	struct com_softc *sc = device_private(self);
2543 
2544 	mutex_spin_enter(&sc->sc_lock);
2545 	com_loadchannelregs(sc);
2546 	mutex_spin_exit(&sc->sc_lock);
2547 
2548 	return true;
2549 }
2550