xref: /netbsd-src/sys/dev/ic/com.c (revision ce099b40997c43048fb78bd578195f81d2456523)
1 /*	$NetBSD: com.c,v 1.280 2008/04/28 20:23:49 martin 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 1.280 2008/04/28 20:23:49 martin 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 #if NRND > 0 && defined(RND_COM)
80 #include <sys/rnd.h>
81 #endif
82 
83 /* The COM16650 option was renamed to COM_16650. */
84 #ifdef COM16650
85 #error Obsolete COM16650 option; use COM_16650 instead.
86 #endif
87 
88 /*
89  * Override cnmagic(9) macro before including <sys/systm.h>.
90  * We need to know if cn_check_magic triggered debugger, so set a flag.
91  * Callers of cn_check_magic must declare int cn_trapped = 0;
92  * XXX: this is *ugly*!
93  */
94 #define cn_trap()				\
95 	do {					\
96 		console_debugger();		\
97 		cn_trapped = 1;			\
98 	} while (/* CONSTCOND */ 0)
99 
100 #include <sys/param.h>
101 #include <sys/systm.h>
102 #include <sys/ioctl.h>
103 #include <sys/select.h>
104 #include <sys/poll.h>
105 #include <sys/tty.h>
106 #include <sys/proc.h>
107 #include <sys/user.h>
108 #include <sys/conf.h>
109 #include <sys/file.h>
110 #include <sys/uio.h>
111 #include <sys/kernel.h>
112 #include <sys/syslog.h>
113 #include <sys/device.h>
114 #include <sys/malloc.h>
115 #include <sys/timepps.h>
116 #include <sys/vnode.h>
117 #include <sys/kauth.h>
118 #include <sys/intr.h>
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 void	com_common_putc(dev_t, struct com_regs *, int);
177 
178 int	cominit(struct com_regs *, int, int, int, tcflag_t);
179 
180 int	comcngetc(dev_t);
181 void	comcnputc(dev_t, int);
182 void	comcnpollc(dev_t, int);
183 
184 #define	integrate	static inline
185 void 	comsoft(void *);
186 integrate void com_rxsoft(struct com_softc *, struct tty *);
187 integrate void com_txsoft(struct com_softc *, struct tty *);
188 integrate void com_stsoft(struct com_softc *, struct tty *);
189 integrate void com_schedrx(struct com_softc *);
190 void	comdiag(void *);
191 
192 extern struct cfdriver com_cd;
193 
194 dev_type_open(comopen);
195 dev_type_close(comclose);
196 dev_type_read(comread);
197 dev_type_write(comwrite);
198 dev_type_ioctl(comioctl);
199 dev_type_stop(comstop);
200 dev_type_tty(comtty);
201 dev_type_poll(compoll);
202 
203 const struct cdevsw com_cdevsw = {
204 	comopen, comclose, comread, comwrite, comioctl,
205 	comstop, comtty, compoll, nommap, ttykqfilter, D_TTY
206 };
207 
208 /*
209  * Make this an option variable one can patch.
210  * But be warned:  this must be a power of 2!
211  */
212 u_int com_rbuf_size = COM_RING_SIZE;
213 
214 /* Stop input when 3/4 of the ring is full; restart when only 1/4 is full. */
215 u_int com_rbuf_hiwat = (COM_RING_SIZE * 1) / 4;
216 u_int com_rbuf_lowat = (COM_RING_SIZE * 3) / 4;
217 
218 static struct com_regs comconsregs;
219 static int comconsattached;
220 static int comconsrate;
221 static tcflag_t comconscflag;
222 static struct cnm_state com_cnm_state;
223 
224 #ifdef KGDB
225 #include <sys/kgdb.h>
226 
227 static struct com_regs comkgdbregs;
228 static int com_kgdb_attached;
229 
230 int	com_kgdb_getc(void *);
231 void	com_kgdb_putc(void *, int);
232 #endif /* KGDB */
233 
234 #ifdef COM_REGMAP
235 /* initializer for typical 16550-ish hardware */
236 #define	COM_REG_16550	{ \
237 	com_data, com_data, com_dlbl, com_dlbh, com_ier, com_iir, com_fifo, \
238 	com_efr, com_lcr, com_mcr, com_lsr, com_msr }
239 
240 const bus_size_t com_std_map[16] = COM_REG_16550;
241 #endif /* COM_REGMAP */
242 
243 #define	COMUNIT_MASK	0x7ffff
244 #define	COMDIALOUT_MASK	0x80000
245 
246 #define	COMUNIT(x)	(minor(x) & COMUNIT_MASK)
247 #define	COMDIALOUT(x)	(minor(x) & COMDIALOUT_MASK)
248 
249 #define	COM_ISALIVE(sc)	((sc)->enabled != 0 && \
250 			 device_is_active((sc)->sc_dev))
251 
252 #define	BR	BUS_SPACE_BARRIER_READ
253 #define	BW	BUS_SPACE_BARRIER_WRITE
254 #define COM_BARRIER(r, f) \
255 	bus_space_barrier((r)->cr_iot, (r)->cr_ioh, 0, (r)->cr_nports, (f))
256 
257 /*ARGSUSED*/
258 int
259 comspeed(long speed, long frequency, int type)
260 {
261 #define	divrnd(n, q)	(((n)*2/(q)+1)/2)	/* divide and round off */
262 
263 	int x, err;
264 
265 #if 0
266 	if (speed == 0)
267 		return (0);
268 #endif
269 	if (speed <= 0)
270 		return (-1);
271 	x = divrnd(frequency / 16, speed);
272 	if (x <= 0)
273 		return (-1);
274 	err = divrnd(((quad_t)frequency) * 1000 / 16, speed * x) - 1000;
275 	if (err < 0)
276 		err = -err;
277 	if (err > COM_TOLERANCE)
278 		return (-1);
279 	return (x);
280 
281 #undef	divrnd
282 }
283 
284 #ifdef COM_DEBUG
285 int	com_debug = 0;
286 
287 void comstatus(struct com_softc *, const char *);
288 void
289 comstatus(struct com_softc *sc, const char *str)
290 {
291 	struct tty *tp = sc->sc_tty;
292 
293 	aprint_normal_dev(sc->sc_dev,
294 	    "%s %cclocal  %cdcd %cts_carr_on %cdtr %ctx_stopped\n",
295 	    str,
296 	    ISSET(tp->t_cflag, CLOCAL) ? '+' : '-',
297 	    ISSET(sc->sc_msr, MSR_DCD) ? '+' : '-',
298 	    ISSET(tp->t_state, TS_CARR_ON) ? '+' : '-',
299 	    ISSET(sc->sc_mcr, MCR_DTR) ? '+' : '-',
300 	    sc->sc_tx_stopped ? '+' : '-');
301 
302 	aprint_normal_dev(sc->sc_dev,
303 	    "%s %ccrtscts %ccts %cts_ttstop  %crts rx_flags=0x%x\n",
304 	    str,
305 	    ISSET(tp->t_cflag, CRTSCTS) ? '+' : '-',
306 	    ISSET(sc->sc_msr, MSR_CTS) ? '+' : '-',
307 	    ISSET(tp->t_state, TS_TTSTOP) ? '+' : '-',
308 	    ISSET(sc->sc_mcr, MCR_RTS) ? '+' : '-',
309 	    sc->sc_rx_flags);
310 }
311 #endif
312 
313 int
314 com_probe_subr(struct com_regs *regs)
315 {
316 
317 	/* force access to id reg */
318 	CSR_WRITE_1(regs, COM_REG_LCR, LCR_8BITS);
319 	CSR_WRITE_1(regs, COM_REG_IIR, 0);
320 	if ((CSR_READ_1(regs, COM_REG_LCR) != LCR_8BITS) ||
321 	    (CSR_READ_1(regs, COM_REG_IIR) & 0x38))
322 		return (0);
323 
324 	return (1);
325 }
326 
327 int
328 comprobe1(bus_space_tag_t iot, bus_space_handle_t ioh)
329 {
330 	struct com_regs	regs;
331 
332 	regs.cr_iot = iot;
333 	regs.cr_ioh = ioh;
334 #ifdef	COM_REGMAP
335 	memcpy(regs.cr_map, com_std_map, sizeof (regs.cr_map));;
336 #endif
337 
338 	return com_probe_subr(&regs);
339 }
340 
341 /*
342  * No locking in this routine; it is only called during attach,
343  * or with the port already locked.
344  */
345 static void
346 com_enable_debugport(struct com_softc *sc)
347 {
348 
349 	/* Turn on line break interrupt, set carrier. */
350 	sc->sc_ier = IER_ERXRDY;
351 	if (sc->sc_type == COM_TYPE_PXA2x0)
352 		sc->sc_ier |= IER_EUART | IER_ERXTOUT;
353 	CSR_WRITE_1(&sc->sc_regs, COM_REG_IER, sc->sc_ier);
354 	SET(sc->sc_mcr, MCR_DTR | MCR_RTS);
355 	CSR_WRITE_1(&sc->sc_regs, COM_REG_MCR, sc->sc_mcr);
356 }
357 
358 void
359 com_attach_subr(struct com_softc *sc)
360 {
361 	struct com_regs *regsp = &sc->sc_regs;
362 	struct tty *tp;
363 #ifdef COM_16650
364 	u_int8_t lcr;
365 #endif
366 	const char *fifo_msg = NULL;
367 
368 	aprint_naive("\n");
369 
370 	callout_init(&sc->sc_diag_callout, 0);
371 	mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_HIGH);
372 
373 	/* Disable interrupts before configuring the device. */
374 	if (sc->sc_type == COM_TYPE_PXA2x0)
375 		sc->sc_ier = IER_EUART;
376 	else
377 		sc->sc_ier = 0;
378 
379 	CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
380 
381 	if (regsp->cr_iot == comconsregs.cr_iot &&
382 	    regsp->cr_iobase == comconsregs.cr_iobase) {
383 		comconsattached = 1;
384 
385 		/* Make sure the console is always "hardwired". */
386 		delay(10000);			/* wait for output to finish */
387 		SET(sc->sc_hwflags, COM_HW_CONSOLE);
388 		SET(sc->sc_swflags, TIOCFLAG_SOFTCAR);
389 	}
390 
391 	/* Probe for FIFO */
392 	switch (sc->sc_type) {
393 	case COM_TYPE_HAYESP:
394 		goto fifodone;
395 
396 	case COM_TYPE_AU1x00:
397 		sc->sc_fifolen = 16;
398 		fifo_msg = "Au1X00 UART, working fifo";
399 		SET(sc->sc_hwflags, COM_HW_FIFO);
400 		goto fifodelay;
401 	}
402 
403 	sc->sc_fifolen = 1;
404 	/* look for a NS 16550AF UART with FIFOs */
405 	CSR_WRITE_1(regsp, COM_REG_FIFO,
406 	    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_14);
407 	delay(100);
408 	if (ISSET(CSR_READ_1(regsp, COM_REG_IIR), IIR_FIFO_MASK)
409 	    == IIR_FIFO_MASK)
410 		if (ISSET(CSR_READ_1(regsp, COM_REG_FIFO), FIFO_TRIGGER_14)
411 		    == FIFO_TRIGGER_14) {
412 			SET(sc->sc_hwflags, COM_HW_FIFO);
413 
414 #ifdef COM_16650
415 			/*
416 			 * IIR changes into the EFR if LCR is set to LCR_EERS
417 			 * on 16650s. We also know IIR != 0 at this point.
418 			 * Write 0 into the EFR, and read it. If the result
419 			 * is 0, we have a 16650.
420 			 *
421 			 * Older 16650s were broken; the test to detect them
422 			 * is taken from the Linux driver. Apparently
423 			 * setting DLAB enable gives access to the EFR on
424 			 * these chips.
425 			 */
426 			lcr = CSR_READ_1(regsp, COM_REG_LCR);
427 			CSR_WRITE_1(regsp, COM_REG_LCR, LCR_EERS);
428 			CSR_WRITE_1(regsp, COM_REG_EFR, 0);
429 			if (CSR_READ_1(regsp, COM_REG_EFR) == 0) {
430 				CSR_WRITE_1(regsp, COM_REG_LCR,
431 				    lcr | LCR_DLAB);
432 				if (CSR_READ_1(regsp, COM_REG_EFR) == 0) {
433 					CLR(sc->sc_hwflags, COM_HW_FIFO);
434 					sc->sc_fifolen = 0;
435 				} else {
436 					SET(sc->sc_hwflags, COM_HW_FLOW);
437 					sc->sc_fifolen = 32;
438 				}
439 			} else
440 #endif
441 				sc->sc_fifolen = 16;
442 
443 #ifdef COM_16650
444 			CSR_WRITE_1(regsp, COM_REG_LCR, lcr);
445 			if (sc->sc_fifolen == 0)
446 				fifo_msg = "st16650, broken fifo";
447 			else if (sc->sc_fifolen == 32)
448 				fifo_msg = "st16650a, working fifo";
449 			else
450 #endif
451 				fifo_msg = "ns16550a, working fifo";
452 		} else
453 			fifo_msg = "ns16550, broken fifo";
454 	else
455 		fifo_msg = "ns8250 or ns16450, no fifo";
456 	CSR_WRITE_1(regsp, COM_REG_FIFO, 0);
457 fifodelay:
458 	/*
459 	 * Some chips will clear down both Tx and Rx FIFOs when zero is
460 	 * written to com_fifo. If this chip is the console, writing zero
461 	 * results in some of the chip/FIFO description being lost, so delay
462 	 * printing it until now.
463 	 */
464 	delay(10);
465 	aprint_normal(": %s\n", fifo_msg);
466 	if (ISSET(sc->sc_hwflags, COM_HW_TXFIFO_DISABLE)) {
467 		sc->sc_fifolen = 1;
468 		aprint_normal_dev(sc->sc_dev, "txfifo disabled\n");
469 	}
470 
471 fifodone:
472 
473 	tp = ttymalloc();
474 	tp->t_oproc = comstart;
475 	tp->t_param = comparam;
476 	tp->t_hwiflow = comhwiflow;
477 
478 	sc->sc_tty = tp;
479 	sc->sc_rbuf = malloc(com_rbuf_size << 1, M_DEVBUF, M_NOWAIT);
480 	sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
481 	sc->sc_rbavail = com_rbuf_size;
482 	if (sc->sc_rbuf == NULL) {
483 		aprint_error_dev(sc->sc_dev,
484 		    "unable to allocate ring buffer\n");
485 		return;
486 	}
487 	sc->sc_ebuf = sc->sc_rbuf + (com_rbuf_size << 1);
488 
489 	tty_attach(tp);
490 
491 	if (!ISSET(sc->sc_hwflags, COM_HW_NOIEN))
492 		SET(sc->sc_mcr, MCR_IENABLE);
493 
494 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
495 		int maj;
496 
497 		/* locate the major number */
498 		maj = cdevsw_lookup_major(&com_cdevsw);
499 
500 		tp->t_dev = cn_tab->cn_dev = makedev(maj,
501 						     device_unit(sc->sc_dev));
502 
503 		aprint_normal_dev(sc->sc_dev, "console\n");
504 	}
505 
506 #ifdef KGDB
507 	/*
508 	 * Allow kgdb to "take over" this port.  If this is
509 	 * not the console and is the kgdb device, it has
510 	 * exclusive use.  If it's the console _and_ the
511 	 * kgdb device, it doesn't.
512 	 */
513 	if (regsp->cr_iot == comkgdbregs.cr_iot &&
514 	    regsp->cr_iobase == comkgdbregs.cr_iobase) {
515 		if (!ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
516 			com_kgdb_attached = 1;
517 
518 			SET(sc->sc_hwflags, COM_HW_KGDB);
519 		}
520 		aprint_normal_dev(sc->sc_dev, "kgdb\n");
521 	}
522 #endif
523 
524 	sc->sc_si = softint_establish(SOFTINT_SERIAL, comsoft, sc);
525 
526 #if NRND > 0 && defined(RND_COM)
527 	rnd_attach_source(&sc->rnd_source, device_xname(sc->sc_dev),
528 			  RND_TYPE_TTY, 0);
529 #endif
530 
531 	/* if there are no enable/disable functions, assume the device
532 	   is always enabled */
533 	if (!sc->enable)
534 		sc->enabled = 1;
535 
536 	com_config(sc);
537 
538 	SET(sc->sc_hwflags, COM_HW_DEV_OK);
539 }
540 
541 void
542 com_config(struct com_softc *sc)
543 {
544 	struct com_regs *regsp = &sc->sc_regs;
545 
546 	/* Disable interrupts before configuring the device. */
547 	if (sc->sc_type == COM_TYPE_PXA2x0)
548 		sc->sc_ier = IER_EUART;
549 	else
550 		sc->sc_ier = 0;
551 	CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
552 	(void) CSR_READ_1(regsp, COM_REG_IIR);
553 
554 #ifdef COM_HAYESP
555 	/* Look for a Hayes ESP board. */
556 	if (sc->sc_type == COM_TYPE_HAYESP) {
557 
558 		/* Set 16550 compatibility mode */
559 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD1,
560 				  HAYESP_SETMODE);
561 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
562 				  HAYESP_MODE_FIFO|HAYESP_MODE_RTS|
563 				  HAYESP_MODE_SCALE);
564 
565 		/* Set RTS/CTS flow control */
566 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD1,
567 				  HAYESP_SETFLOWTYPE);
568 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
569 				  HAYESP_FLOW_RTS);
570 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
571 				  HAYESP_FLOW_CTS);
572 
573 		/* Set flow control levels */
574 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD1,
575 				  HAYESP_SETRXFLOW);
576 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
577 				  HAYESP_HIBYTE(HAYESP_RXHIWMARK));
578 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
579 				  HAYESP_LOBYTE(HAYESP_RXHIWMARK));
580 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
581 				  HAYESP_HIBYTE(HAYESP_RXLOWMARK));
582 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
583 				  HAYESP_LOBYTE(HAYESP_RXLOWMARK));
584 	}
585 #endif
586 
587 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE|COM_HW_KGDB))
588 		com_enable_debugport(sc);
589 }
590 
591 int
592 com_detach(device_t self, int flags)
593 {
594 	struct com_softc *sc = device_private(self);
595 	int maj, mn;
596 
597         if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE))
598 		return EBUSY;
599 
600 	/* locate the major number */
601 	maj = cdevsw_lookup_major(&com_cdevsw);
602 
603 	/* Nuke the vnodes for any open instances. */
604 	mn = device_unit(self);
605 	vdevgone(maj, mn, mn, VCHR);
606 
607 	mn |= COMDIALOUT_MASK;
608 	vdevgone(maj, mn, mn, VCHR);
609 
610 	if (sc->sc_rbuf == NULL) {
611 		/*
612 		 * Ring buffer allocation failed in the com_attach_subr,
613 		 * only the tty is allocated, and nothing else.
614 		 */
615 		ttyfree(sc->sc_tty);
616 		return 0;
617 	}
618 
619 	/* Free the receive buffer. */
620 	free(sc->sc_rbuf, M_DEVBUF);
621 
622 	/* Detach and free the tty. */
623 	tty_detach(sc->sc_tty);
624 	ttyfree(sc->sc_tty);
625 
626 	/* Unhook the soft interrupt handler. */
627 	softint_disestablish(sc->sc_si);
628 
629 #if NRND > 0 && defined(RND_COM)
630 	/* Unhook the entropy source. */
631 	rnd_detach_source(&sc->rnd_source);
632 #endif
633 	callout_destroy(&sc->sc_diag_callout);
634 
635 	/* Destroy the lock. */
636 	mutex_destroy(&sc->sc_lock);
637 
638 	return (0);
639 }
640 
641 int
642 com_activate(device_t self, enum devact act)
643 {
644 	struct com_softc *sc = device_private(self);
645 	int rv = 0;
646 
647 	switch (act) {
648 	case DVACT_ACTIVATE:
649 		rv = EOPNOTSUPP;
650 		break;
651 
652 	case DVACT_DEACTIVATE:
653 		if (sc->sc_hwflags & (COM_HW_CONSOLE|COM_HW_KGDB)) {
654 			rv = EBUSY;
655 			break;
656 		}
657 
658 		if (sc->disable != NULL && sc->enabled != 0) {
659 			(*sc->disable)(sc);
660 			sc->enabled = 0;
661 		}
662 		break;
663 	}
664 
665 	return (rv);
666 }
667 
668 void
669 com_shutdown(struct com_softc *sc)
670 {
671 	struct tty *tp = sc->sc_tty;
672 
673 	mutex_spin_enter(&sc->sc_lock);
674 
675 	/* If we were asserting flow control, then deassert it. */
676 	SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
677 	com_hwiflow(sc);
678 
679 	/* Clear any break condition set with TIOCSBRK. */
680 	com_break(sc, 0);
681 
682 	/*
683 	 * Hang up if necessary.  Wait a bit, so the other side has time to
684 	 * notice even if we immediately open the port again.
685 	 * Avoid tsleeping above splhigh().
686 	 */
687 	if (ISSET(tp->t_cflag, HUPCL)) {
688 		com_modem(sc, 0);
689 		mutex_spin_exit(&sc->sc_lock);
690 		/* XXX will only timeout */
691 		(void) kpause(ttclos, false, hz, NULL);
692 		mutex_spin_enter(&sc->sc_lock);
693 	}
694 
695 	/* Turn off interrupts. */
696 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
697 		sc->sc_ier = IER_ERXRDY; /* interrupt on break */
698 		if (sc->sc_type == COM_TYPE_PXA2x0)
699 			sc->sc_ier |= IER_ERXTOUT;
700 	} else
701 		sc->sc_ier = 0;
702 
703 	if (sc->sc_type == COM_TYPE_PXA2x0)
704 		sc->sc_ier |= IER_EUART;
705 
706 	CSR_WRITE_1(&sc->sc_regs, COM_REG_IER, sc->sc_ier);
707 
708 	mutex_spin_exit(&sc->sc_lock);
709 
710 	if (sc->disable) {
711 #ifdef DIAGNOSTIC
712 		if (!sc->enabled)
713 			panic("com_shutdown: not enabled?");
714 #endif
715 		(*sc->disable)(sc);
716 		sc->enabled = 0;
717 	}
718 }
719 
720 int
721 comopen(dev_t dev, int flag, int mode, struct lwp *l)
722 {
723 	struct com_softc *sc;
724 	struct tty *tp;
725 	int s;
726 	int error;
727 
728 	sc = device_lookup_private(&com_cd, COMUNIT(dev));
729 	if (sc == NULL || !ISSET(sc->sc_hwflags, COM_HW_DEV_OK) ||
730 		sc->sc_rbuf == NULL)
731 		return (ENXIO);
732 
733 	if (!device_is_active(sc->sc_dev))
734 		return (ENXIO);
735 
736 #ifdef KGDB
737 	/*
738 	 * If this is the kgdb port, no other use is permitted.
739 	 */
740 	if (ISSET(sc->sc_hwflags, COM_HW_KGDB))
741 		return (EBUSY);
742 #endif
743 
744 	tp = sc->sc_tty;
745 
746 	if (kauth_authorize_device_tty(l->l_cred, KAUTH_DEVICE_TTY_OPEN, tp))
747 		return (EBUSY);
748 
749 	s = spltty();
750 
751 	/*
752 	 * Do the following iff this is a first open.
753 	 */
754 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
755 		struct termios t;
756 
757 		tp->t_dev = dev;
758 
759 
760 		if (sc->enable) {
761 			if ((*sc->enable)(sc)) {
762 				splx(s);
763 				aprint_error_dev(sc->sc_dev,
764 				    "device enable failed\n");
765 				return (EIO);
766 			}
767 			mutex_spin_enter(&sc->sc_lock);
768 			sc->enabled = 1;
769 			com_config(sc);
770 		} else {
771 			mutex_spin_enter(&sc->sc_lock);
772 		}
773 
774 		/* Turn on interrupts. */
775 		sc->sc_ier = IER_ERXRDY | IER_ERLS | IER_EMSC;
776 		if (sc->sc_type == COM_TYPE_PXA2x0)
777 			sc->sc_ier |= IER_EUART | IER_ERXTOUT;
778 		CSR_WRITE_1(&sc->sc_regs, COM_REG_IER, sc->sc_ier);
779 
780 		/* Fetch the current modem control status, needed later. */
781 		sc->sc_msr = CSR_READ_1(&sc->sc_regs, COM_REG_MSR);
782 
783 		/* Clear PPS capture state on first open. */
784 		mutex_spin_enter(&timecounter_lock);
785 		memset(&sc->sc_pps_state, 0, sizeof(sc->sc_pps_state));
786 		sc->sc_pps_state.ppscap = PPS_CAPTUREASSERT | PPS_CAPTURECLEAR;
787 		pps_init(&sc->sc_pps_state);
788 		mutex_spin_exit(&timecounter_lock);
789 
790 		mutex_spin_exit(&sc->sc_lock);
791 
792 		/*
793 		 * Initialize the termios status to the defaults.  Add in the
794 		 * sticky bits from TIOCSFLAGS.
795 		 */
796 		if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
797 			t.c_ospeed = comconsrate;
798 			t.c_cflag = comconscflag;
799 		} else {
800 			t.c_ospeed = TTYDEF_SPEED;
801 			t.c_cflag = TTYDEF_CFLAG;
802 		}
803 		t.c_ispeed = t.c_ospeed;
804 		if (ISSET(sc->sc_swflags, TIOCFLAG_CLOCAL))
805 			SET(t.c_cflag, CLOCAL);
806 		if (ISSET(sc->sc_swflags, TIOCFLAG_CRTSCTS))
807 			SET(t.c_cflag, CRTSCTS);
808 		if (ISSET(sc->sc_swflags, TIOCFLAG_MDMBUF))
809 			SET(t.c_cflag, MDMBUF);
810 		/* Make sure comparam() will do something. */
811 		tp->t_ospeed = 0;
812 		(void) comparam(tp, &t);
813 		tp->t_iflag = TTYDEF_IFLAG;
814 		tp->t_oflag = TTYDEF_OFLAG;
815 		tp->t_lflag = TTYDEF_LFLAG;
816 		ttychars(tp);
817 		ttsetwater(tp);
818 
819 		mutex_spin_enter(&sc->sc_lock);
820 
821 		/*
822 		 * Turn on DTR.  We must always do this, even if carrier is not
823 		 * present, because otherwise we'd have to use TIOCSDTR
824 		 * immediately after setting CLOCAL, which applications do not
825 		 * expect.  We always assert DTR while the device is open
826 		 * unless explicitly requested to deassert it.
827 		 */
828 		com_modem(sc, 1);
829 
830 		/* Clear the input ring, and unblock. */
831 		sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
832 		sc->sc_rbavail = com_rbuf_size;
833 		com_iflush(sc);
834 		CLR(sc->sc_rx_flags, RX_ANY_BLOCK);
835 		com_hwiflow(sc);
836 
837 #ifdef COM_DEBUG
838 		if (com_debug)
839 			comstatus(sc, "comopen  ");
840 #endif
841 
842 		mutex_spin_exit(&sc->sc_lock);
843 	}
844 
845 	splx(s);
846 
847 	error = ttyopen(tp, COMDIALOUT(dev), ISSET(flag, O_NONBLOCK));
848 	if (error)
849 		goto bad;
850 
851 	error = (*tp->t_linesw->l_open)(dev, tp);
852 	if (error)
853 		goto bad;
854 
855 	return (0);
856 
857 bad:
858 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
859 		/*
860 		 * We failed to open the device, and nobody else had it opened.
861 		 * Clean up the state as appropriate.
862 		 */
863 		com_shutdown(sc);
864 	}
865 
866 	return (error);
867 }
868 
869 int
870 comclose(dev_t dev, int flag, int mode, struct lwp *l)
871 {
872 	struct com_softc *sc =
873 	    device_lookup_private(&com_cd, COMUNIT(dev));
874 	struct tty *tp = sc->sc_tty;
875 
876 	/* XXX This is for cons.c. */
877 	if (!ISSET(tp->t_state, TS_ISOPEN))
878 		return (0);
879 
880 	(*tp->t_linesw->l_close)(tp, flag);
881 	ttyclose(tp);
882 
883 	if (COM_ISALIVE(sc) == 0)
884 		return (0);
885 
886 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
887 		/*
888 		 * Although we got a last close, the device may still be in
889 		 * use; e.g. if this was the dialout node, and there are still
890 		 * processes waiting for carrier on the non-dialout node.
891 		 */
892 		com_shutdown(sc);
893 	}
894 
895 	return (0);
896 }
897 
898 int
899 comread(dev_t dev, struct uio *uio, int flag)
900 {
901 	struct com_softc *sc =
902 	    device_lookup_private(&com_cd, COMUNIT(dev));
903 	struct tty *tp = sc->sc_tty;
904 
905 	if (COM_ISALIVE(sc) == 0)
906 		return (EIO);
907 
908 	return ((*tp->t_linesw->l_read)(tp, uio, flag));
909 }
910 
911 int
912 comwrite(dev_t dev, struct uio *uio, int flag)
913 {
914 	struct com_softc *sc =
915 	    device_lookup_private(&com_cd, COMUNIT(dev));
916 	struct tty *tp = sc->sc_tty;
917 
918 	if (COM_ISALIVE(sc) == 0)
919 		return (EIO);
920 
921 	return ((*tp->t_linesw->l_write)(tp, uio, flag));
922 }
923 
924 int
925 compoll(dev_t dev, int events, struct lwp *l)
926 {
927 	struct com_softc *sc =
928 	    device_lookup_private(&com_cd, COMUNIT(dev));
929 	struct tty *tp = sc->sc_tty;
930 
931 	if (COM_ISALIVE(sc) == 0)
932 		return (POLLHUP);
933 
934 	return ((*tp->t_linesw->l_poll)(tp, events, l));
935 }
936 
937 struct tty *
938 comtty(dev_t dev)
939 {
940 	struct com_softc *sc =
941 	    device_lookup_private(&com_cd, COMUNIT(dev));
942 	struct tty *tp = sc->sc_tty;
943 
944 	return (tp);
945 }
946 
947 int
948 comioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
949 {
950 	struct com_softc *sc;
951 	struct tty *tp;
952 	int error;
953 
954 	sc = device_lookup_private(&com_cd, COMUNIT(dev));
955 	if (sc == NULL)
956 		return ENXIO;
957 	if (COM_ISALIVE(sc) == 0)
958 		return (EIO);
959 
960 	tp = sc->sc_tty;
961 
962 	error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, l);
963 	if (error != EPASSTHROUGH)
964 		return (error);
965 
966 	error = ttioctl(tp, cmd, data, flag, l);
967 	if (error != EPASSTHROUGH)
968 		return (error);
969 
970 	error = 0;
971 	switch (cmd) {
972 	case TIOCSFLAGS:
973 		error = kauth_authorize_device_tty(l->l_cred,
974 		    KAUTH_DEVICE_TTY_PRIVSET, tp);
975 		break;
976 	default:
977 		/* nothing */
978 		break;
979 	}
980 	if (error) {
981 		return error;
982 	}
983 
984 	mutex_spin_enter(&sc->sc_lock);
985 
986 	switch (cmd) {
987 	case TIOCSBRK:
988 		com_break(sc, 1);
989 		break;
990 
991 	case TIOCCBRK:
992 		com_break(sc, 0);
993 		break;
994 
995 	case TIOCSDTR:
996 		com_modem(sc, 1);
997 		break;
998 
999 	case TIOCCDTR:
1000 		com_modem(sc, 0);
1001 		break;
1002 
1003 	case TIOCGFLAGS:
1004 		*(int *)data = sc->sc_swflags;
1005 		break;
1006 
1007 	case TIOCSFLAGS:
1008 		sc->sc_swflags = *(int *)data;
1009 		break;
1010 
1011 	case TIOCMSET:
1012 	case TIOCMBIS:
1013 	case TIOCMBIC:
1014 		tiocm_to_com(sc, cmd, *(int *)data);
1015 		break;
1016 
1017 	case TIOCMGET:
1018 		*(int *)data = com_to_tiocm(sc);
1019 		break;
1020 
1021 	case PPS_IOC_CREATE:
1022 	case PPS_IOC_DESTROY:
1023 	case PPS_IOC_GETPARAMS:
1024 	case PPS_IOC_SETPARAMS:
1025 	case PPS_IOC_GETCAP:
1026 	case PPS_IOC_FETCH:
1027 #ifdef PPS_SYNC
1028 	case PPS_IOC_KCBIND:
1029 #endif
1030 		mutex_spin_enter(&timecounter_lock);
1031 		error = pps_ioctl(cmd, data, &sc->sc_pps_state);
1032 		mutex_spin_exit(&timecounter_lock);
1033 		break;
1034 
1035 	case TIOCDCDTIMESTAMP:	/* XXX old, overloaded  API used by xntpd v3 */
1036 		mutex_spin_enter(&timecounter_lock);
1037 #ifndef PPS_TRAILING_EDGE
1038 		TIMESPEC_TO_TIMEVAL((struct timeval *)data,
1039 		    &sc->sc_pps_state.ppsinfo.assert_timestamp);
1040 #else
1041 		TIMESPEC_TO_TIMEVAL((struct timeval *)data,
1042 		    &sc->sc_pps_state.ppsinfo.clear_timestamp);
1043 #endif
1044 		mutex_spin_exit(&timecounter_lock);
1045 		break;
1046 
1047 	default:
1048 		error = EPASSTHROUGH;
1049 		break;
1050 	}
1051 
1052 	mutex_spin_exit(&sc->sc_lock);
1053 
1054 #ifdef COM_DEBUG
1055 	if (com_debug)
1056 		comstatus(sc, "comioctl ");
1057 #endif
1058 
1059 	return (error);
1060 }
1061 
1062 integrate void
1063 com_schedrx(struct com_softc *sc)
1064 {
1065 
1066 	sc->sc_rx_ready = 1;
1067 
1068 	/* Wake up the poller. */
1069 	softint_schedule(sc->sc_si);
1070 }
1071 
1072 void
1073 com_break(struct com_softc *sc, int onoff)
1074 {
1075 
1076 	if (onoff)
1077 		SET(sc->sc_lcr, LCR_SBREAK);
1078 	else
1079 		CLR(sc->sc_lcr, LCR_SBREAK);
1080 
1081 	if (!sc->sc_heldchange) {
1082 		if (sc->sc_tx_busy) {
1083 			sc->sc_heldtbc = sc->sc_tbc;
1084 			sc->sc_tbc = 0;
1085 			sc->sc_heldchange = 1;
1086 		} else
1087 			com_loadchannelregs(sc);
1088 	}
1089 }
1090 
1091 void
1092 com_modem(struct com_softc *sc, int onoff)
1093 {
1094 
1095 	if (sc->sc_mcr_dtr == 0)
1096 		return;
1097 
1098 	if (onoff)
1099 		SET(sc->sc_mcr, sc->sc_mcr_dtr);
1100 	else
1101 		CLR(sc->sc_mcr, sc->sc_mcr_dtr);
1102 
1103 	if (!sc->sc_heldchange) {
1104 		if (sc->sc_tx_busy) {
1105 			sc->sc_heldtbc = sc->sc_tbc;
1106 			sc->sc_tbc = 0;
1107 			sc->sc_heldchange = 1;
1108 		} else
1109 			com_loadchannelregs(sc);
1110 	}
1111 }
1112 
1113 void
1114 tiocm_to_com(struct com_softc *sc, u_long how, int ttybits)
1115 {
1116 	u_char combits;
1117 
1118 	combits = 0;
1119 	if (ISSET(ttybits, TIOCM_DTR))
1120 		SET(combits, MCR_DTR);
1121 	if (ISSET(ttybits, TIOCM_RTS))
1122 		SET(combits, MCR_RTS);
1123 
1124 	switch (how) {
1125 	case TIOCMBIC:
1126 		CLR(sc->sc_mcr, combits);
1127 		break;
1128 
1129 	case TIOCMBIS:
1130 		SET(sc->sc_mcr, combits);
1131 		break;
1132 
1133 	case TIOCMSET:
1134 		CLR(sc->sc_mcr, MCR_DTR | MCR_RTS);
1135 		SET(sc->sc_mcr, combits);
1136 		break;
1137 	}
1138 
1139 	if (!sc->sc_heldchange) {
1140 		if (sc->sc_tx_busy) {
1141 			sc->sc_heldtbc = sc->sc_tbc;
1142 			sc->sc_tbc = 0;
1143 			sc->sc_heldchange = 1;
1144 		} else
1145 			com_loadchannelregs(sc);
1146 	}
1147 }
1148 
1149 int
1150 com_to_tiocm(struct com_softc *sc)
1151 {
1152 	u_char combits;
1153 	int ttybits = 0;
1154 
1155 	combits = sc->sc_mcr;
1156 	if (ISSET(combits, MCR_DTR))
1157 		SET(ttybits, TIOCM_DTR);
1158 	if (ISSET(combits, MCR_RTS))
1159 		SET(ttybits, TIOCM_RTS);
1160 
1161 	combits = sc->sc_msr;
1162 	if (ISSET(combits, MSR_DCD))
1163 		SET(ttybits, TIOCM_CD);
1164 	if (ISSET(combits, MSR_CTS))
1165 		SET(ttybits, TIOCM_CTS);
1166 	if (ISSET(combits, MSR_DSR))
1167 		SET(ttybits, TIOCM_DSR);
1168 	if (ISSET(combits, MSR_RI | MSR_TERI))
1169 		SET(ttybits, TIOCM_RI);
1170 
1171 	if (ISSET(sc->sc_ier, IER_ERXRDY | IER_ETXRDY | IER_ERLS | IER_EMSC))
1172 		SET(ttybits, TIOCM_LE);
1173 
1174 	return (ttybits);
1175 }
1176 
1177 static u_char
1178 cflag2lcr(tcflag_t cflag)
1179 {
1180 	u_char lcr = 0;
1181 
1182 	switch (ISSET(cflag, CSIZE)) {
1183 	case CS5:
1184 		SET(lcr, LCR_5BITS);
1185 		break;
1186 	case CS6:
1187 		SET(lcr, LCR_6BITS);
1188 		break;
1189 	case CS7:
1190 		SET(lcr, LCR_7BITS);
1191 		break;
1192 	case CS8:
1193 		SET(lcr, LCR_8BITS);
1194 		break;
1195 	}
1196 	if (ISSET(cflag, PARENB)) {
1197 		SET(lcr, LCR_PENAB);
1198 		if (!ISSET(cflag, PARODD))
1199 			SET(lcr, LCR_PEVEN);
1200 	}
1201 	if (ISSET(cflag, CSTOPB))
1202 		SET(lcr, LCR_STOPB);
1203 
1204 	return (lcr);
1205 }
1206 
1207 int
1208 comparam(struct tty *tp, struct termios *t)
1209 {
1210 	struct com_softc *sc =
1211 	    device_lookup_private(&com_cd, COMUNIT(tp->t_dev));
1212 	int ospeed;
1213 	u_char lcr;
1214 
1215 	if (COM_ISALIVE(sc) == 0)
1216 		return (EIO);
1217 
1218 #ifdef COM_HAYESP
1219 	if (sc->sc_type == COM_TYPE_HAYESP) {
1220 		int prescaler, speed;
1221 
1222 		/*
1223 		 * Calculate UART clock prescaler.  It should be in
1224 		 * range of 0 .. 3.
1225 		 */
1226 		for (prescaler = 0, speed = t->c_ospeed; prescaler < 4;
1227 		    prescaler++, speed /= 2)
1228 			if ((ospeed = comspeed(speed, sc->sc_frequency,
1229 					       sc->sc_type)) > 0)
1230 				break;
1231 
1232 		if (prescaler == 4)
1233 			return (EINVAL);
1234 		sc->sc_prescaler = prescaler;
1235 	} else
1236 #endif
1237 	ospeed = comspeed(t->c_ospeed, sc->sc_frequency, sc->sc_type);
1238 
1239 	/* Check requested parameters. */
1240 	if (ospeed < 0)
1241 		return (EINVAL);
1242 	if (t->c_ispeed && t->c_ispeed != t->c_ospeed)
1243 		return (EINVAL);
1244 
1245 	/*
1246 	 * For the console, always force CLOCAL and !HUPCL, so that the port
1247 	 * is always active.
1248 	 */
1249 	if (ISSET(sc->sc_swflags, TIOCFLAG_SOFTCAR) ||
1250 	    ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
1251 		SET(t->c_cflag, CLOCAL);
1252 		CLR(t->c_cflag, HUPCL);
1253 	}
1254 
1255 	/*
1256 	 * If there were no changes, don't do anything.  This avoids dropping
1257 	 * input and improves performance when all we did was frob things like
1258 	 * VMIN and VTIME.
1259 	 */
1260 	if (tp->t_ospeed == t->c_ospeed &&
1261 	    tp->t_cflag == t->c_cflag)
1262 		return (0);
1263 
1264 	lcr = ISSET(sc->sc_lcr, LCR_SBREAK) | cflag2lcr(t->c_cflag);
1265 
1266 	mutex_spin_enter(&sc->sc_lock);
1267 
1268 	sc->sc_lcr = lcr;
1269 
1270 	/*
1271 	 * If we're not in a mode that assumes a connection is present, then
1272 	 * ignore carrier changes.
1273 	 */
1274 	if (ISSET(t->c_cflag, CLOCAL | MDMBUF))
1275 		sc->sc_msr_dcd = 0;
1276 	else
1277 		sc->sc_msr_dcd = MSR_DCD;
1278 	/*
1279 	 * Set the flow control pins depending on the current flow control
1280 	 * mode.
1281 	 */
1282 	if (ISSET(t->c_cflag, CRTSCTS)) {
1283 		sc->sc_mcr_dtr = MCR_DTR;
1284 		sc->sc_mcr_rts = MCR_RTS;
1285 		sc->sc_msr_cts = MSR_CTS;
1286 		sc->sc_efr = EFR_AUTORTS | EFR_AUTOCTS;
1287 	} else if (ISSET(t->c_cflag, MDMBUF)) {
1288 		/*
1289 		 * For DTR/DCD flow control, make sure we don't toggle DTR for
1290 		 * carrier detection.
1291 		 */
1292 		sc->sc_mcr_dtr = 0;
1293 		sc->sc_mcr_rts = MCR_DTR;
1294 		sc->sc_msr_cts = MSR_DCD;
1295 		sc->sc_efr = 0;
1296 	} else {
1297 		/*
1298 		 * If no flow control, then always set RTS.  This will make
1299 		 * the other side happy if it mistakenly thinks we're doing
1300 		 * RTS/CTS flow control.
1301 		 */
1302 		sc->sc_mcr_dtr = MCR_DTR | MCR_RTS;
1303 		sc->sc_mcr_rts = 0;
1304 		sc->sc_msr_cts = 0;
1305 		sc->sc_efr = 0;
1306 		if (ISSET(sc->sc_mcr, MCR_DTR))
1307 			SET(sc->sc_mcr, MCR_RTS);
1308 		else
1309 			CLR(sc->sc_mcr, MCR_RTS);
1310 	}
1311 	sc->sc_msr_mask = sc->sc_msr_cts | sc->sc_msr_dcd;
1312 
1313 #if 0
1314 	if (ospeed == 0)
1315 		CLR(sc->sc_mcr, sc->sc_mcr_dtr);
1316 	else
1317 		SET(sc->sc_mcr, sc->sc_mcr_dtr);
1318 #endif
1319 
1320 	sc->sc_dlbl = ospeed;
1321 	sc->sc_dlbh = ospeed >> 8;
1322 
1323 	/*
1324 	 * Set the FIFO threshold based on the receive speed.
1325 	 *
1326 	 *  * If it's a low speed, it's probably a mouse or some other
1327 	 *    interactive device, so set the threshold low.
1328 	 *  * If it's a high speed, trim the trigger level down to prevent
1329 	 *    overflows.
1330 	 *  * Otherwise set it a bit higher.
1331 	 */
1332 	if (sc->sc_type == COM_TYPE_HAYESP)
1333 		sc->sc_fifo = FIFO_DMA_MODE | FIFO_ENABLE | FIFO_TRIGGER_8;
1334 	else if (ISSET(sc->sc_hwflags, COM_HW_FIFO)) {
1335 		if (t->c_ospeed <= 1200)
1336 			sc->sc_fifo = FIFO_ENABLE | FIFO_TRIGGER_1;
1337 		else if (t->c_ospeed <= 38400)
1338 			sc->sc_fifo = FIFO_ENABLE | FIFO_TRIGGER_8;
1339 		else
1340 			sc->sc_fifo = FIFO_ENABLE | FIFO_TRIGGER_4;
1341 	} else
1342 		sc->sc_fifo = 0;
1343 
1344 	/* And copy to tty. */
1345 	tp->t_ispeed = t->c_ospeed;
1346 	tp->t_ospeed = t->c_ospeed;
1347 	tp->t_cflag = t->c_cflag;
1348 
1349 	if (!sc->sc_heldchange) {
1350 		if (sc->sc_tx_busy) {
1351 			sc->sc_heldtbc = sc->sc_tbc;
1352 			sc->sc_tbc = 0;
1353 			sc->sc_heldchange = 1;
1354 		} else
1355 			com_loadchannelregs(sc);
1356 	}
1357 
1358 	if (!ISSET(t->c_cflag, CHWFLOW)) {
1359 		/* Disable the high water mark. */
1360 		sc->sc_r_hiwat = 0;
1361 		sc->sc_r_lowat = 0;
1362 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
1363 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1364 			com_schedrx(sc);
1365 		}
1366 		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED)) {
1367 			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED);
1368 			com_hwiflow(sc);
1369 		}
1370 	} else {
1371 		sc->sc_r_hiwat = com_rbuf_hiwat;
1372 		sc->sc_r_lowat = com_rbuf_lowat;
1373 	}
1374 
1375 	mutex_spin_exit(&sc->sc_lock);
1376 
1377 	/*
1378 	 * Update the tty layer's idea of the carrier bit, in case we changed
1379 	 * CLOCAL or MDMBUF.  We don't hang up here; we only do that by
1380 	 * explicit request.
1381 	 */
1382 	(void) (*tp->t_linesw->l_modem)(tp, ISSET(sc->sc_msr, MSR_DCD));
1383 
1384 #ifdef COM_DEBUG
1385 	if (com_debug)
1386 		comstatus(sc, "comparam ");
1387 #endif
1388 
1389 	if (!ISSET(t->c_cflag, CHWFLOW)) {
1390 		if (sc->sc_tx_stopped) {
1391 			sc->sc_tx_stopped = 0;
1392 			comstart(tp);
1393 		}
1394 	}
1395 
1396 	return (0);
1397 }
1398 
1399 void
1400 com_iflush(struct com_softc *sc)
1401 {
1402 	struct com_regs	*regsp = &sc->sc_regs;
1403 #ifdef DIAGNOSTIC
1404 	int reg;
1405 #endif
1406 	int timo;
1407 
1408 #ifdef DIAGNOSTIC
1409 	reg = 0xffff;
1410 #endif
1411 	timo = 50000;
1412 	/* flush any pending I/O */
1413 	while (ISSET(CSR_READ_1(regsp, COM_REG_LSR), LSR_RXRDY)
1414 	    && --timo)
1415 #ifdef DIAGNOSTIC
1416 		reg =
1417 #else
1418 		    (void)
1419 #endif
1420 		    CSR_READ_1(regsp, COM_REG_RXDATA);
1421 #ifdef DIAGNOSTIC
1422 	if (!timo)
1423 		aprint_error_dev(sc->sc_dev, "com_iflush timeout %02x\n", reg);
1424 #endif
1425 }
1426 
1427 void
1428 com_loadchannelregs(struct com_softc *sc)
1429 {
1430 	struct com_regs *regsp = &sc->sc_regs;
1431 
1432 	/* XXXXX necessary? */
1433 	com_iflush(sc);
1434 
1435 	if (sc->sc_type == COM_TYPE_PXA2x0)
1436 		CSR_WRITE_1(regsp, COM_REG_IER, IER_EUART);
1437 	else
1438 		CSR_WRITE_1(regsp, COM_REG_IER, 0);
1439 
1440 	if (ISSET(sc->sc_hwflags, COM_HW_FLOW)) {
1441 		if (sc->sc_type != COM_TYPE_AU1x00) {	/* no EFR on alchemy */
1442 			CSR_WRITE_1(regsp, COM_REG_EFR, sc->sc_efr);
1443 			CSR_WRITE_1(regsp, COM_REG_LCR, LCR_EERS);
1444 		}
1445 	}
1446 	if (sc->sc_type == COM_TYPE_AU1x00) {
1447 		/* alchemy has single separate 16-bit clock divisor register */
1448 		CSR_WRITE_2(regsp, COM_REG_DLBL, sc->sc_dlbl +
1449 		    (sc->sc_dlbh << 8));
1450 	} else {
1451 		CSR_WRITE_1(regsp, COM_REG_LCR, sc->sc_lcr | LCR_DLAB);
1452 		CSR_WRITE_1(regsp, COM_REG_DLBL, sc->sc_dlbl);
1453 		CSR_WRITE_1(regsp, COM_REG_DLBH, sc->sc_dlbh);
1454 	}
1455 	CSR_WRITE_1(regsp, COM_REG_LCR, sc->sc_lcr);
1456 	CSR_WRITE_1(regsp, COM_REG_MCR, sc->sc_mcr_active = sc->sc_mcr);
1457 	CSR_WRITE_1(regsp, COM_REG_FIFO, sc->sc_fifo);
1458 #ifdef COM_HAYESP
1459 	if (sc->sc_type == COM_TYPE_HAYESP) {
1460 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD1,
1461 		    HAYESP_SETPRESCALER);
1462 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
1463 		    sc->sc_prescaler);
1464 	}
1465 #endif
1466 
1467 	CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
1468 }
1469 
1470 int
1471 comhwiflow(struct tty *tp, int block)
1472 {
1473 	struct com_softc *sc =
1474 	    device_lookup_private(&com_cd, COMUNIT(tp->t_dev));
1475 
1476 	if (COM_ISALIVE(sc) == 0)
1477 		return (0);
1478 
1479 	if (sc->sc_mcr_rts == 0)
1480 		return (0);
1481 
1482 	mutex_spin_enter(&sc->sc_lock);
1483 
1484 	if (block) {
1485 		if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1486 			SET(sc->sc_rx_flags, RX_TTY_BLOCKED);
1487 			com_hwiflow(sc);
1488 		}
1489 	} else {
1490 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
1491 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1492 			com_schedrx(sc);
1493 		}
1494 		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1495 			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED);
1496 			com_hwiflow(sc);
1497 		}
1498 	}
1499 
1500 	mutex_spin_exit(&sc->sc_lock);
1501 	return (1);
1502 }
1503 
1504 /*
1505  * (un)block input via hw flowcontrol
1506  */
1507 void
1508 com_hwiflow(struct com_softc *sc)
1509 {
1510 	struct com_regs *regsp= &sc->sc_regs;
1511 
1512 	if (sc->sc_mcr_rts == 0)
1513 		return;
1514 
1515 	if (ISSET(sc->sc_rx_flags, RX_ANY_BLOCK)) {
1516 		CLR(sc->sc_mcr, sc->sc_mcr_rts);
1517 		CLR(sc->sc_mcr_active, sc->sc_mcr_rts);
1518 	} else {
1519 		SET(sc->sc_mcr, sc->sc_mcr_rts);
1520 		SET(sc->sc_mcr_active, sc->sc_mcr_rts);
1521 	}
1522 	CSR_WRITE_1(regsp, COM_REG_MCR, sc->sc_mcr_active);
1523 }
1524 
1525 
1526 void
1527 comstart(struct tty *tp)
1528 {
1529 	struct com_softc *sc =
1530 	    device_lookup_private(&com_cd, COMUNIT(tp->t_dev));
1531 	struct com_regs *regsp = &sc->sc_regs;
1532 	int s;
1533 
1534 	if (COM_ISALIVE(sc) == 0)
1535 		return;
1536 
1537 	s = spltty();
1538 	if (ISSET(tp->t_state, TS_BUSY | TS_TIMEOUT | TS_TTSTOP))
1539 		goto out;
1540 	if (sc->sc_tx_stopped)
1541 		goto out;
1542 	if (!ttypull(tp))
1543 		goto out;
1544 
1545 	/* Grab the first contiguous region of buffer space. */
1546 	{
1547 		u_char *tba;
1548 		int tbc;
1549 
1550 		tba = tp->t_outq.c_cf;
1551 		tbc = ndqb(&tp->t_outq, 0);
1552 
1553 		mutex_spin_enter(&sc->sc_lock);
1554 
1555 		sc->sc_tba = tba;
1556 		sc->sc_tbc = tbc;
1557 	}
1558 
1559 	SET(tp->t_state, TS_BUSY);
1560 	sc->sc_tx_busy = 1;
1561 
1562 	/* Enable transmit completion interrupts if necessary. */
1563 	if (!ISSET(sc->sc_ier, IER_ETXRDY)) {
1564 		SET(sc->sc_ier, IER_ETXRDY);
1565 		CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
1566 	}
1567 
1568 	/* Output the first chunk of the contiguous buffer. */
1569 	if (!ISSET(sc->sc_hwflags, COM_HW_NO_TXPRELOAD)) {
1570 		u_int n;
1571 
1572 		n = sc->sc_tbc;
1573 		if (n > sc->sc_fifolen)
1574 			n = sc->sc_fifolen;
1575 		CSR_WRITE_MULTI(regsp, COM_REG_TXDATA, sc->sc_tba, n);
1576 		sc->sc_tbc -= n;
1577 		sc->sc_tba += n;
1578 	}
1579 
1580 	mutex_spin_exit(&sc->sc_lock);
1581 out:
1582 	splx(s);
1583 	return;
1584 }
1585 
1586 /*
1587  * Stop output on a line.
1588  */
1589 void
1590 comstop(struct tty *tp, int flag)
1591 {
1592 	struct com_softc *sc =
1593 	    device_lookup_private(&com_cd, COMUNIT(tp->t_dev));
1594 
1595 	mutex_spin_enter(&sc->sc_lock);
1596 	if (ISSET(tp->t_state, TS_BUSY)) {
1597 		/* Stop transmitting at the next chunk. */
1598 		sc->sc_tbc = 0;
1599 		sc->sc_heldtbc = 0;
1600 		if (!ISSET(tp->t_state, TS_TTSTOP))
1601 			SET(tp->t_state, TS_FLUSH);
1602 	}
1603 	mutex_spin_exit(&sc->sc_lock);
1604 }
1605 
1606 void
1607 comdiag(void *arg)
1608 {
1609 	struct com_softc *sc = arg;
1610 	int overflows, floods;
1611 
1612 	mutex_spin_enter(&sc->sc_lock);
1613 	overflows = sc->sc_overflows;
1614 	sc->sc_overflows = 0;
1615 	floods = sc->sc_floods;
1616 	sc->sc_floods = 0;
1617 	sc->sc_errors = 0;
1618 	mutex_spin_exit(&sc->sc_lock);
1619 
1620 	log(LOG_WARNING, "%s: %d silo overflow%s, %d ibuf flood%s\n",
1621 	    device_xname(sc->sc_dev),
1622 	    overflows, overflows == 1 ? "" : "s",
1623 	    floods, floods == 1 ? "" : "s");
1624 }
1625 
1626 integrate void
1627 com_rxsoft(struct com_softc *sc, struct tty *tp)
1628 {
1629 	int (*rint)(int, struct tty *) = tp->t_linesw->l_rint;
1630 	u_char *get, *end;
1631 	u_int cc, scc;
1632 	u_char lsr;
1633 	int code;
1634 
1635 	end = sc->sc_ebuf;
1636 	get = sc->sc_rbget;
1637 	scc = cc = com_rbuf_size - sc->sc_rbavail;
1638 
1639 	if (cc == com_rbuf_size) {
1640 		sc->sc_floods++;
1641 		if (sc->sc_errors++ == 0)
1642 			callout_reset(&sc->sc_diag_callout, 60 * hz,
1643 			    comdiag, sc);
1644 	}
1645 
1646 	/* If not yet open, drop the entire buffer content here */
1647 	if (!ISSET(tp->t_state, TS_ISOPEN)) {
1648 		get += cc << 1;
1649 		if (get >= end)
1650 			get -= com_rbuf_size << 1;
1651 		cc = 0;
1652 	}
1653 	while (cc) {
1654 		code = get[0];
1655 		lsr = get[1];
1656 		if (ISSET(lsr, LSR_OE | LSR_BI | LSR_FE | LSR_PE)) {
1657 			if (ISSET(lsr, LSR_OE)) {
1658 				sc->sc_overflows++;
1659 				if (sc->sc_errors++ == 0)
1660 					callout_reset(&sc->sc_diag_callout,
1661 					    60 * hz, comdiag, sc);
1662 			}
1663 			if (ISSET(lsr, LSR_BI | LSR_FE))
1664 				SET(code, TTY_FE);
1665 			if (ISSET(lsr, LSR_PE))
1666 				SET(code, TTY_PE);
1667 		}
1668 		if ((*rint)(code, tp) == -1) {
1669 			/*
1670 			 * The line discipline's buffer is out of space.
1671 			 */
1672 			if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1673 				/*
1674 				 * We're either not using flow control, or the
1675 				 * line discipline didn't tell us to block for
1676 				 * some reason.  Either way, we have no way to
1677 				 * know when there's more space available, so
1678 				 * just drop the rest of the data.
1679 				 */
1680 				get += cc << 1;
1681 				if (get >= end)
1682 					get -= com_rbuf_size << 1;
1683 				cc = 0;
1684 			} else {
1685 				/*
1686 				 * Don't schedule any more receive processing
1687 				 * until the line discipline tells us there's
1688 				 * space available (through comhwiflow()).
1689 				 * Leave the rest of the data in the input
1690 				 * buffer.
1691 				 */
1692 				SET(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1693 			}
1694 			break;
1695 		}
1696 		get += 2;
1697 		if (get >= end)
1698 			get = sc->sc_rbuf;
1699 		cc--;
1700 	}
1701 
1702 	if (cc != scc) {
1703 		sc->sc_rbget = get;
1704 		mutex_spin_enter(&sc->sc_lock);
1705 
1706 		cc = sc->sc_rbavail += scc - cc;
1707 		/* Buffers should be ok again, release possible block. */
1708 		if (cc >= sc->sc_r_lowat) {
1709 			if (ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
1710 				CLR(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
1711 				SET(sc->sc_ier, IER_ERXRDY);
1712 #ifdef COM_PXA2X0
1713 				if (sc->sc_type == COM_TYPE_PXA2x0)
1714 					SET(sc->sc_ier, IER_ERXTOUT);
1715 #endif
1716 				CSR_WRITE_1(&sc->sc_regs, COM_REG_IER, sc->sc_ier);
1717 			}
1718 			if (ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED)) {
1719 				CLR(sc->sc_rx_flags, RX_IBUF_BLOCKED);
1720 				com_hwiflow(sc);
1721 			}
1722 		}
1723 		mutex_spin_exit(&sc->sc_lock);
1724 	}
1725 }
1726 
1727 integrate void
1728 com_txsoft(struct com_softc *sc, struct tty *tp)
1729 {
1730 
1731 	CLR(tp->t_state, TS_BUSY);
1732 	if (ISSET(tp->t_state, TS_FLUSH))
1733 		CLR(tp->t_state, TS_FLUSH);
1734 	else
1735 		ndflush(&tp->t_outq, (int)(sc->sc_tba - tp->t_outq.c_cf));
1736 	(*tp->t_linesw->l_start)(tp);
1737 }
1738 
1739 integrate void
1740 com_stsoft(struct com_softc *sc, struct tty *tp)
1741 {
1742 	u_char msr, delta;
1743 
1744 	mutex_spin_enter(&sc->sc_lock);
1745 	msr = sc->sc_msr;
1746 	delta = sc->sc_msr_delta;
1747 	sc->sc_msr_delta = 0;
1748 	mutex_spin_exit(&sc->sc_lock);
1749 
1750 	if (ISSET(delta, sc->sc_msr_dcd)) {
1751 		/*
1752 		 * Inform the tty layer that carrier detect changed.
1753 		 */
1754 		(void) (*tp->t_linesw->l_modem)(tp, ISSET(msr, MSR_DCD));
1755 	}
1756 
1757 	if (ISSET(delta, sc->sc_msr_cts)) {
1758 		/* Block or unblock output according to flow control. */
1759 		if (ISSET(msr, sc->sc_msr_cts)) {
1760 			sc->sc_tx_stopped = 0;
1761 			(*tp->t_linesw->l_start)(tp);
1762 		} else {
1763 			sc->sc_tx_stopped = 1;
1764 		}
1765 	}
1766 
1767 #ifdef COM_DEBUG
1768 	if (com_debug)
1769 		comstatus(sc, "com_stsoft");
1770 #endif
1771 }
1772 
1773 void
1774 comsoft(void *arg)
1775 {
1776 	struct com_softc *sc = arg;
1777 	struct tty *tp;
1778 
1779 	if (COM_ISALIVE(sc) == 0)
1780 		return;
1781 
1782 	tp = sc->sc_tty;
1783 
1784 	if (sc->sc_rx_ready) {
1785 		sc->sc_rx_ready = 0;
1786 		com_rxsoft(sc, tp);
1787 	}
1788 
1789 	if (sc->sc_st_check) {
1790 		sc->sc_st_check = 0;
1791 		com_stsoft(sc, tp);
1792 	}
1793 
1794 	if (sc->sc_tx_done) {
1795 		sc->sc_tx_done = 0;
1796 		com_txsoft(sc, tp);
1797 	}
1798 }
1799 
1800 int
1801 comintr(void *arg)
1802 {
1803 	struct com_softc *sc = arg;
1804 	struct com_regs *regsp = &sc->sc_regs;
1805 
1806 	u_char *put, *end;
1807 	u_int cc;
1808 	u_char lsr, iir;
1809 
1810 	if (COM_ISALIVE(sc) == 0)
1811 		return (0);
1812 
1813 	mutex_spin_enter(&sc->sc_lock);
1814 	iir = CSR_READ_1(regsp, COM_REG_IIR);
1815 	if (ISSET(iir, IIR_NOPEND)) {
1816 		mutex_spin_exit(&sc->sc_lock);
1817 		return (0);
1818 	}
1819 
1820 	end = sc->sc_ebuf;
1821 	put = sc->sc_rbput;
1822 	cc = sc->sc_rbavail;
1823 
1824 again:	do {
1825 		u_char	msr, delta;
1826 
1827 		lsr = CSR_READ_1(regsp, COM_REG_LSR);
1828 		if (ISSET(lsr, LSR_BI)) {
1829 			int cn_trapped = 0;
1830 
1831 			cn_check_magic(sc->sc_tty->t_dev,
1832 				       CNC_BREAK, com_cnm_state);
1833 			if (cn_trapped)
1834 				continue;
1835 #if defined(KGDB) && !defined(DDB)
1836 			if (ISSET(sc->sc_hwflags, COM_HW_KGDB)) {
1837 				kgdb_connect(1);
1838 				continue;
1839 			}
1840 #endif
1841 		}
1842 
1843 		if (ISSET(lsr, LSR_RCV_MASK) &&
1844 		    !ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
1845 			while (cc > 0) {
1846 				int cn_trapped = 0;
1847 				put[0] = CSR_READ_1(regsp, COM_REG_RXDATA);
1848 				put[1] = lsr;
1849 				cn_check_magic(sc->sc_tty->t_dev,
1850 					       put[0], com_cnm_state);
1851 				if (cn_trapped)
1852 					goto next;
1853 				put += 2;
1854 				if (put >= end)
1855 					put = sc->sc_rbuf;
1856 				cc--;
1857 			next:
1858 				lsr = CSR_READ_1(regsp, COM_REG_LSR);
1859 				if (!ISSET(lsr, LSR_RCV_MASK))
1860 					break;
1861 			}
1862 
1863 			/*
1864 			 * Current string of incoming characters ended because
1865 			 * no more data was available or we ran out of space.
1866 			 * Schedule a receive event if any data was received.
1867 			 * If we're out of space, turn off receive interrupts.
1868 			 */
1869 			sc->sc_rbput = put;
1870 			sc->sc_rbavail = cc;
1871 			if (!ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED))
1872 				sc->sc_rx_ready = 1;
1873 
1874 			/*
1875 			 * See if we are in danger of overflowing a buffer. If
1876 			 * so, use hardware flow control to ease the pressure.
1877 			 */
1878 			if (!ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED) &&
1879 			    cc < sc->sc_r_hiwat) {
1880 				SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
1881 				com_hwiflow(sc);
1882 			}
1883 
1884 			/*
1885 			 * If we're out of space, disable receive interrupts
1886 			 * until the queue has drained a bit.
1887 			 */
1888 			if (!cc) {
1889 				SET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
1890 #ifdef COM_PXA2X0
1891 				if (sc->sc_type == COM_TYPE_PXA2x0)
1892 					CLR(sc->sc_ier, IER_ERXRDY|IER_ERXTOUT);
1893 				else
1894 #endif
1895 					CLR(sc->sc_ier, IER_ERXRDY);
1896 				CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
1897 			}
1898 		} else {
1899 			if ((iir & (IIR_RXRDY|IIR_TXRDY)) == IIR_RXRDY) {
1900 				(void) CSR_READ_1(regsp, COM_REG_RXDATA);
1901 				continue;
1902 			}
1903 		}
1904 
1905 		msr = CSR_READ_1(regsp, COM_REG_MSR);
1906 		delta = msr ^ sc->sc_msr;
1907 		sc->sc_msr = msr;
1908 		if ((sc->sc_pps_state.ppsparam.mode & PPS_CAPTUREBOTH) &&
1909 		    (delta & MSR_DCD)) {
1910 			mutex_spin_enter(&timecounter_lock);
1911 			pps_capture(&sc->sc_pps_state);
1912 			pps_event(&sc->sc_pps_state,
1913 			    (msr & MSR_DCD) ?
1914 			    PPS_CAPTUREASSERT :
1915 			    PPS_CAPTURECLEAR);
1916 			mutex_spin_exit(&timecounter_lock);
1917 		}
1918 
1919 		/*
1920 		 * Process normal status changes
1921 		 */
1922 		if (ISSET(delta, sc->sc_msr_mask)) {
1923 			SET(sc->sc_msr_delta, delta);
1924 
1925 			/*
1926 			 * Stop output immediately if we lose the output
1927 			 * flow control signal or carrier detect.
1928 			 */
1929 			if (ISSET(~msr, sc->sc_msr_mask)) {
1930 				sc->sc_tbc = 0;
1931 				sc->sc_heldtbc = 0;
1932 #ifdef COM_DEBUG
1933 				if (com_debug)
1934 					comstatus(sc, "comintr  ");
1935 #endif
1936 			}
1937 
1938 			sc->sc_st_check = 1;
1939 		}
1940 	} while (!ISSET((iir =
1941 	    CSR_READ_1(regsp, COM_REG_IIR)), IIR_NOPEND) &&
1942 	    /*
1943 	     * Since some device (e.g., ST16C1550) doesn't clear IIR_TXRDY
1944 	     * by IIR read, so we can't do this way: `process all interrupts,
1945 	     * then do TX if possble'.
1946 	     */
1947 	    (iir & IIR_IMASK) != IIR_TXRDY);
1948 
1949 	/*
1950 	 * Read LSR again, since there may be an interrupt between
1951 	 * the last LSR read and IIR read above.
1952 	 */
1953 	lsr = CSR_READ_1(regsp, COM_REG_LSR);
1954 
1955 	/*
1956 	 * See if data can be transmitted as well.
1957 	 * Schedule tx done event if no data left
1958 	 * and tty was marked busy.
1959 	 */
1960 	if (ISSET(lsr, LSR_TXRDY)) {
1961 		/*
1962 		 * If we've delayed a parameter change, do it now, and restart
1963 		 * output.
1964 		 */
1965 		if (sc->sc_heldchange) {
1966 			com_loadchannelregs(sc);
1967 			sc->sc_heldchange = 0;
1968 			sc->sc_tbc = sc->sc_heldtbc;
1969 			sc->sc_heldtbc = 0;
1970 		}
1971 
1972 		/* Output the next chunk of the contiguous buffer, if any. */
1973 		if (sc->sc_tbc > 0) {
1974 			u_int n;
1975 
1976 			n = sc->sc_tbc;
1977 			if (n > sc->sc_fifolen)
1978 				n = sc->sc_fifolen;
1979 			CSR_WRITE_MULTI(regsp, COM_REG_TXDATA, sc->sc_tba, n);
1980 			sc->sc_tbc -= n;
1981 			sc->sc_tba += n;
1982 		} else {
1983 			/* Disable transmit completion interrupts if necessary. */
1984 			if (ISSET(sc->sc_ier, IER_ETXRDY)) {
1985 				CLR(sc->sc_ier, IER_ETXRDY);
1986 				CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
1987 			}
1988 			if (sc->sc_tx_busy) {
1989 				sc->sc_tx_busy = 0;
1990 				sc->sc_tx_done = 1;
1991 			}
1992 		}
1993 	}
1994 
1995 	if (!ISSET((iir = CSR_READ_1(regsp, COM_REG_IIR)), IIR_NOPEND))
1996 		goto again;
1997 
1998 	mutex_spin_exit(&sc->sc_lock);
1999 
2000 	/* Wake up the poller. */
2001 	softint_schedule(sc->sc_si);
2002 
2003 #if NRND > 0 && defined(RND_COM)
2004 	rnd_add_uint32(&sc->rnd_source, iir | lsr);
2005 #endif
2006 
2007 	return (1);
2008 }
2009 
2010 /*
2011  * The following functions are polled getc and putc routines, shared
2012  * by the console and kgdb glue.
2013  *
2014  * The read-ahead code is so that you can detect pending in-band
2015  * cn_magic in polled mode while doing output rather than having to
2016  * wait until the kernel decides it needs input.
2017  */
2018 
2019 #define MAX_READAHEAD	20
2020 static int com_readahead[MAX_READAHEAD];
2021 static int com_readaheadcount = 0;
2022 
2023 int
2024 com_common_getc(dev_t dev, struct com_regs *regsp)
2025 {
2026 	int s = splserial();
2027 	u_char stat, c;
2028 
2029 	/* got a character from reading things earlier */
2030 	if (com_readaheadcount > 0) {
2031 		int i;
2032 
2033 		c = com_readahead[0];
2034 		for (i = 1; i < com_readaheadcount; i++) {
2035 			com_readahead[i-1] = com_readahead[i];
2036 		}
2037 		com_readaheadcount--;
2038 		splx(s);
2039 		return (c);
2040 	}
2041 
2042 	/* block until a character becomes available */
2043 	while (!ISSET(stat = CSR_READ_1(regsp, COM_REG_LSR), LSR_RXRDY))
2044 		;
2045 
2046 	c = CSR_READ_1(regsp, COM_REG_RXDATA);
2047 	stat = CSR_READ_1(regsp, COM_REG_IIR);
2048 	{
2049 		int cn_trapped = 0; /* unused */
2050 #ifdef DDB
2051 		extern int db_active;
2052 		if (!db_active)
2053 #endif
2054 			cn_check_magic(dev, c, com_cnm_state);
2055 	}
2056 	splx(s);
2057 	return (c);
2058 }
2059 
2060 void
2061 com_common_putc(dev_t dev, struct com_regs *regsp, int c)
2062 {
2063 	int s = splserial();
2064 	int cin, stat, timo;
2065 
2066 	if (com_readaheadcount < MAX_READAHEAD
2067 	     && ISSET(stat = CSR_READ_1(regsp, COM_REG_LSR), LSR_RXRDY)) {
2068 		int cn_trapped = 0;
2069 		cin = CSR_READ_1(regsp, COM_REG_RXDATA);
2070 		stat = CSR_READ_1(regsp, COM_REG_IIR);
2071 		cn_check_magic(dev, cin, com_cnm_state);
2072 		com_readahead[com_readaheadcount++] = cin;
2073 	}
2074 
2075 	/* wait for any pending transmission to finish */
2076 	timo = 150000;
2077 	while (!ISSET(CSR_READ_1(regsp, COM_REG_LSR), LSR_TXRDY) && --timo)
2078 		continue;
2079 
2080 	CSR_WRITE_1(regsp, COM_REG_TXDATA, c);
2081 	COM_BARRIER(regsp, BR | BW);
2082 
2083 	splx(s);
2084 }
2085 
2086 /*
2087  * Initialize UART for use as console or KGDB line.
2088  */
2089 int
2090 cominit(struct com_regs *regsp, int rate, int frequency, int type,
2091     tcflag_t cflag)
2092 {
2093 
2094 	if (bus_space_map(regsp->cr_iot, regsp->cr_iobase, regsp->cr_nports, 0,
2095 		&regsp->cr_ioh))
2096 		return (ENOMEM); /* ??? */
2097 
2098 	rate = comspeed(rate, frequency, type);
2099 	if (type != COM_TYPE_AU1x00) {
2100 		/* no EFR on alchemy */
2101 		CSR_WRITE_1(regsp, COM_REG_LCR, LCR_EERS);
2102 		CSR_WRITE_1(regsp, COM_REG_EFR, 0);
2103 		CSR_WRITE_1(regsp, COM_REG_LCR, LCR_DLAB);
2104 		CSR_WRITE_1(regsp, COM_REG_DLBL, rate & 0xff);
2105 		CSR_WRITE_1(regsp, COM_REG_DLBH, rate >> 8);
2106 	} else {
2107 		CSR_WRITE_1(regsp, COM_REG_DLBL, rate);
2108 	}
2109 	CSR_WRITE_1(regsp, COM_REG_LCR, cflag2lcr(cflag));
2110 	CSR_WRITE_1(regsp, COM_REG_MCR, MCR_DTR | MCR_RTS);
2111 	CSR_WRITE_1(regsp, COM_REG_FIFO,
2112 	    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_1);
2113 #ifdef COM_PXA2X0
2114 	if (type == COM_TYPE_PXA2x0)
2115 		CSR_WRITE_1(regsp, COM_REG_IER, IER_EUART);
2116 	else
2117 #endif
2118 		CSR_WRITE_1(regsp, COM_REG_IER, 0);
2119 
2120 	return (0);
2121 }
2122 
2123 /*
2124  * Following are all routines needed for COM to act as console
2125  */
2126 struct consdev comcons = {
2127 	NULL, NULL, comcngetc, comcnputc, comcnpollc, NULL, NULL, NULL,
2128 	NODEV, CN_NORMAL
2129 };
2130 
2131 
2132 int
2133 comcnattach1(struct com_regs *regsp, int rate, int frequency, int type,
2134     tcflag_t cflag)
2135 {
2136 	int res;
2137 
2138 	comconsregs = *regsp;
2139 
2140 	res = cominit(&comconsregs, rate, frequency, type, cflag);
2141 	if (res)
2142 		return (res);
2143 
2144 	cn_tab = &comcons;
2145 	cn_init_magic(&com_cnm_state);
2146 	cn_set_magic("\047\001"); /* default magic is BREAK */
2147 
2148 	comconsrate = rate;
2149 	comconscflag = cflag;
2150 
2151 	return (0);
2152 }
2153 
2154 int
2155 comcnattach(bus_space_tag_t iot, bus_addr_t iobase, int rate, int frequency,
2156     int type, tcflag_t cflag)
2157 {
2158 	struct com_regs	regs;
2159 
2160 	memset(&regs, 0, sizeof regs);
2161 	regs.cr_iot = iot;
2162 	regs.cr_iobase = iobase;
2163 	regs.cr_nports = COM_NPORTS;
2164 #ifdef	COM_REGMAP
2165 	memcpy(regs.cr_map, com_std_map, sizeof (regs.cr_map));
2166 #endif
2167 
2168 	return comcnattach1(&regs, rate, frequency, type, cflag);
2169 }
2170 
2171 int
2172 comcngetc(dev_t dev)
2173 {
2174 
2175 	return (com_common_getc(dev, &comconsregs));
2176 }
2177 
2178 /*
2179  * Console kernel output character routine.
2180  */
2181 void
2182 comcnputc(dev_t dev, int c)
2183 {
2184 
2185 	com_common_putc(dev, &comconsregs, c);
2186 }
2187 
2188 void
2189 comcnpollc(dev_t dev, int on)
2190 {
2191 
2192 }
2193 
2194 #ifdef KGDB
2195 int
2196 com_kgdb_attach1(struct com_regs *regsp, int rate, int frequency, int type,
2197     tcflag_t cflag)
2198 {
2199 	int res;
2200 
2201 	if (regsp->cr_iot == comconsregs.cr_iot &&
2202 	    regsp->cr_iobase == comconsregs.cr_iobase) {
2203 #if !defined(DDB)
2204 		return (EBUSY); /* cannot share with console */
2205 #else
2206 		comkgdbregs = *regsp;
2207 		comkgdbregs.cr_ioh = comconsregs.cr_ioh;
2208 #endif
2209 	} else {
2210 		comkgdbregs = *regsp;
2211 		res = cominit(&comkgdbregs, rate, frequency, type, cflag);
2212 		if (res)
2213 			return (res);
2214 
2215 		/*
2216 		 * XXXfvdl this shouldn't be needed, but the cn_magic goo
2217 		 * expects this to be initialized
2218 		 */
2219 		cn_init_magic(&com_cnm_state);
2220 		cn_set_magic("\047\001");
2221 	}
2222 
2223 	kgdb_attach(com_kgdb_getc, com_kgdb_putc, NULL);
2224 	kgdb_dev = 123; /* unneeded, only to satisfy some tests */
2225 
2226 	return (0);
2227 }
2228 
2229 int
2230 com_kgdb_attach(bus_space_tag_t iot, bus_addr_t iobase, int rate,
2231     int frequency, int type, tcflag_t cflag)
2232 {
2233 	struct com_regs regs;
2234 
2235 	regs.cr_iot = iot;
2236 	regs.cr_nports = COM_NPORTS;
2237 	regs.cr_iobase = iobase;
2238 #ifdef COM_REGMAP
2239 	memcpy(regs.cr_map, com_std_map, sizeof (regs.cr_map));
2240 #endif
2241 
2242 	return com_kgdb_attach1(&regs, rate, frequency, type, cflag);
2243 }
2244 
2245 /* ARGSUSED */
2246 int
2247 com_kgdb_getc(void *arg)
2248 {
2249 
2250 	return (com_common_getc(NODEV, &comkgdbregs));
2251 }
2252 
2253 /* ARGSUSED */
2254 void
2255 com_kgdb_putc(void *arg, int c)
2256 {
2257 
2258 	com_common_putc(NODEV, &comkgdbregs, c);
2259 }
2260 #endif /* KGDB */
2261 
2262 /* helper function to identify the com ports used by
2263  console or KGDB (and not yet autoconf attached) */
2264 int
2265 com_is_console(bus_space_tag_t iot, bus_addr_t iobase, bus_space_handle_t *ioh)
2266 {
2267 	bus_space_handle_t help;
2268 
2269 	if (!comconsattached &&
2270 	    iot == comconsregs.cr_iot && iobase == comconsregs.cr_iobase)
2271 		help = comconsregs.cr_ioh;
2272 #ifdef KGDB
2273 	else if (!com_kgdb_attached &&
2274 	    iot == comkgdbregs.cr_iot && iobase == comkgdbregs.cr_iobase)
2275 		help = comkgdbregs.cr_ioh;
2276 #endif
2277 	else
2278 		return (0);
2279 
2280 	if (ioh)
2281 		*ioh = help;
2282 	return (1);
2283 }
2284 
2285 /*
2286  * this routine exists to serve as a shutdown hook for systems that
2287  * have firmware which doesn't interact properly with a com device in
2288  * FIFO mode.
2289  */
2290 bool
2291 com_cleanup(device_t self, int how)
2292 {
2293 	struct com_softc *sc = device_private(self);
2294 
2295 	if (ISSET(sc->sc_hwflags, COM_HW_FIFO))
2296 		CSR_WRITE_1(&sc->sc_regs, COM_REG_FIFO, 0);
2297 
2298 	return true;
2299 }
2300 
2301 bool
2302 com_suspend(device_t self PMF_FN_ARGS)
2303 {
2304 	struct com_softc *sc = device_private(self);
2305 
2306 	CSR_WRITE_1(&sc->sc_regs, COM_REG_IER, 0);
2307 	(void)CSR_READ_1(&sc->sc_regs, COM_REG_IIR);
2308 
2309 	return true;
2310 }
2311 
2312 bool
2313 com_resume(device_t self PMF_FN_ARGS)
2314 {
2315 	struct com_softc *sc = device_private(self);
2316 
2317 	mutex_spin_enter(&sc->sc_lock);
2318 	com_loadchannelregs(sc);
2319 	mutex_spin_exit(&sc->sc_lock);
2320 
2321 	return true;
2322 }
2323