xref: /netbsd-src/sys/arch/arm/s3c2xx0/sscom.c (revision a5847cc334d9a7029f6352b847e9e8d71a0f9e0c)
1 /*	$NetBSD: sscom.c,v 1.33 2011/04/24 16:26:54 rmind Exp $ */
2 
3 /*
4  * Copyright (c) 2002, 2003 Fujitsu Component Limited
5  * Copyright (c) 2002, 2003 Genetec Corporation
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of The Fujitsu Component Limited nor the name of
17  *    Genetec corporation may not be used to endorse or promote products
18  *    derived from this software without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY FUJITSU COMPONENT LIMITED AND GENETEC
21  * CORPORATION ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
22  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
23  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
24  * DISCLAIMED.  IN NO EVENT SHALL FUJITSU COMPONENT LIMITED OR GENETEC
25  * CORPORATION BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
27  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
28  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
29  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 /*-
36  * Copyright (c) 1998, 1999 The NetBSD Foundation, Inc.
37  * All rights reserved.
38  *
39  * This code is derived from software contributed to The NetBSD Foundation
40  * by Charles M. Hannum.
41  *
42  * Redistribution and use in source and binary forms, with or without
43  * modification, are permitted provided that the following conditions
44  * are met:
45  * 1. Redistributions of source code must retain the above copyright
46  *    notice, this list of conditions and the following disclaimer.
47  * 2. Redistributions in binary form must reproduce the above copyright
48  *    notice, this list of conditions and the following disclaimer in the
49  *    documentation and/or other materials provided with the distribution.
50  *
51  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
52  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
53  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
54  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
55  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
56  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
57  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
58  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
59  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
60  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
61  * POSSIBILITY OF SUCH DAMAGE.
62  */
63 
64 /*
65  * Copyright (c) 1991 The Regents of the University of California.
66  * All rights reserved.
67  *
68  * Redistribution and use in source and binary forms, with or without
69  * modification, are permitted provided that the following conditions
70  * are met:
71  * 1. Redistributions of source code must retain the above copyright
72  *    notice, this list of conditions and the following disclaimer.
73  * 2. Redistributions in binary form must reproduce the above copyright
74  *    notice, this list of conditions and the following disclaimer in the
75  *    documentation and/or other materials provided with the distribution.
76  * 3. Neither the name of the University nor the names of its contributors
77  *    may be used to endorse or promote products derived from this software
78  *    without specific prior written permission.
79  *
80  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
81  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
82  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
83  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
84  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
85  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
86  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
87  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
88  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
89  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
90  * SUCH DAMAGE.
91  *
92  *	@(#)com.c	7.5 (Berkeley) 5/16/91
93  */
94 
95 /*
96  * Support integrated UARTs of Samsung S3C2800/2400X/2410X
97  * Derived from sys/dev/ic/com.c
98  */
99 
100 #include <sys/cdefs.h>
101 __KERNEL_RCSID(0, "$NetBSD: sscom.c,v 1.33 2011/04/24 16:26:54 rmind Exp $");
102 
103 #include "opt_sscom.h"
104 #include "opt_ddb.h"
105 #include "opt_kgdb.h"
106 #include "opt_multiprocessor.h"
107 #include "opt_lockdebug.h"
108 
109 #include "rnd.h"
110 #if NRND > 0 && defined(RND_COM)
111 #include <sys/rnd.h>
112 #endif
113 
114 /*
115  * Override cnmagic(9) macro before including <sys/systm.h>.
116  * We need to know if cn_check_magic triggered debugger, so set a flag.
117  * Callers of cn_check_magic must declare int cn_trapped = 0;
118  * XXX: this is *ugly*!
119  */
120 #define cn_trap()				\
121 	do {					\
122 		console_debugger();		\
123 		cn_trapped = 1;			\
124 	} while (/* CONSTCOND */ 0)
125 
126 #include <sys/param.h>
127 #include <sys/systm.h>
128 #include <sys/ioctl.h>
129 #include <sys/select.h>
130 #include <sys/tty.h>
131 #include <sys/proc.h>
132 #include <sys/conf.h>
133 #include <sys/file.h>
134 #include <sys/uio.h>
135 #include <sys/kernel.h>
136 #include <sys/syslog.h>
137 #include <sys/types.h>
138 #include <sys/device.h>
139 #include <sys/malloc.h>
140 #include <sys/timepps.h>
141 #include <sys/vnode.h>
142 #include <sys/kauth.h>
143 #include <sys/intr.h>
144 #include <sys/bus.h>
145 
146 #include <arm/s3c2xx0/s3c2xx0reg.h>
147 #include <arm/s3c2xx0/s3c2xx0var.h>
148 #if defined(SSCOM_S3C2410) || defined(SSCOM_S3C2400)
149 #include <arm/s3c2xx0/s3c24x0reg.h>
150 #elif defined(SSCOM_S3C2800)
151 #include <arm/s3c2xx0/s3c2800reg.h>
152 #endif
153 #include <arm/s3c2xx0/sscom_var.h>
154 #include <dev/cons.h>
155 
156 dev_type_open(sscomopen);
157 dev_type_close(sscomclose);
158 dev_type_read(sscomread);
159 dev_type_write(sscomwrite);
160 dev_type_ioctl(sscomioctl);
161 dev_type_stop(sscomstop);
162 dev_type_tty(sscomtty);
163 dev_type_poll(sscompoll);
164 
165 int	sscomcngetc	(dev_t);
166 void	sscomcnputc	(dev_t, int);
167 void	sscomcnpollc	(dev_t, int);
168 
169 #define	integrate	static inline
170 void 	sscomsoft	(void *);
171 
172 integrate void sscom_rxsoft	(struct sscom_softc *, struct tty *);
173 integrate void sscom_txsoft	(struct sscom_softc *, struct tty *);
174 integrate void sscom_stsoft	(struct sscom_softc *, struct tty *);
175 integrate void sscom_schedrx	(struct sscom_softc *);
176 static void	sscom_modem(struct sscom_softc *, int);
177 static void	sscom_break(struct sscom_softc *, int);
178 static void	sscom_iflush(struct sscom_softc *);
179 static void	sscom_hwiflow(struct sscom_softc *);
180 static void	sscom_loadchannelregs(struct sscom_softc *);
181 static void	tiocm_to_sscom(struct sscom_softc *, u_long, int);
182 static int	sscom_to_tiocm(struct sscom_softc *);
183 static void	tiocm_to_sscom(struct sscom_softc *, u_long, int);
184 static int	sscom_to_tiocm(struct sscom_softc *);
185 static void	sscom_iflush(struct sscom_softc *);
186 
187 static int	sscomhwiflow(struct tty *tp, int block);
188 static int	sscom_init(bus_space_tag_t, const struct sscom_uart_info *,
189 		    int, int, tcflag_t, bus_space_handle_t *);
190 
191 extern struct cfdriver sscom_cd;
192 
193 const struct cdevsw sscom_cdevsw = {
194 	sscomopen, sscomclose, sscomread, sscomwrite, sscomioctl,
195 	sscomstop, sscomtty, sscompoll, nommap, ttykqfilter, D_TTY
196 };
197 
198 /*
199  * Make this an option variable one can patch.
200  * But be warned:  this must be a power of 2!
201  */
202 u_int sscom_rbuf_size = SSCOM_RING_SIZE;
203 
204 /* Stop input when 3/4 of the ring is full; restart when only 1/4 is full. */
205 u_int sscom_rbuf_hiwat = (SSCOM_RING_SIZE * 1) / 4;
206 u_int sscom_rbuf_lowat = (SSCOM_RING_SIZE * 3) / 4;
207 
208 static int	sscomconsunit = -1;
209 static bus_space_tag_t sscomconstag;
210 static bus_space_handle_t sscomconsioh;
211 static int	sscomconsattached;
212 static int	sscomconsrate;
213 static tcflag_t sscomconscflag;
214 static struct cnm_state sscom_cnm_state;
215 
216 #ifdef KGDB
217 #include <sys/kgdb.h>
218 
219 static int sscom_kgdb_unit = -1;
220 static bus_space_tag_t sscom_kgdb_iot;
221 static bus_space_handle_t sscom_kgdb_ioh;
222 static int sscom_kgdb_attached;
223 
224 int	sscom_kgdb_getc (void *);
225 void	sscom_kgdb_putc (void *, int);
226 #endif /* KGDB */
227 
228 #define	SSCOMUNIT_MASK  	0x7f
229 #define	SSCOMDIALOUT_MASK	0x80
230 
231 #define	SSCOMUNIT(x)	(minor(x) & SSCOMUNIT_MASK)
232 #define	SSCOMDIALOUT(x)	(minor(x) & SSCOMDIALOUT_MASK)
233 
234 #if 0
235 #define	SSCOM_ISALIVE(sc)	((sc)->enabled != 0 && \
236 				 device_is_active(&(sc)->sc_dev))
237 #else
238 #define	SSCOM_ISALIVE(sc)	device_is_active(&(sc)->sc_dev)
239 #endif
240 
241 #define	BR	BUS_SPACE_BARRIER_READ
242 #define	BW	BUS_SPACE_BARRIER_WRITE
243 #define SSCOM_BARRIER(t, h, f) /* no-op */
244 
245 #if (defined(MULTIPROCESSOR) || defined(LOCKDEBUG)) && defined(SSCOM_MPLOCK)
246 
247 #define SSCOM_LOCK(sc) simple_lock(&(sc)->sc_lock)
248 #define SSCOM_UNLOCK(sc) simple_unlock(&(sc)->sc_lock)
249 
250 #else
251 
252 #define SSCOM_LOCK(sc)
253 #define SSCOM_UNLOCK(sc)
254 
255 #endif
256 
257 #ifndef SSCOM_TOLERANCE
258 #define	SSCOM_TOLERANCE	30	/* XXX: baud rate tolerance, in 0.1% units */
259 #endif
260 
261 /* value for UCON */
262 #define UCON_RXINT_MASK	  \
263 	(UCON_RXMODE_MASK|UCON_ERRINT|UCON_TOINT|UCON_RXINT_TYPE)
264 #define UCON_RXINT_ENABLE \
265 	(UCON_RXMODE_INT|UCON_ERRINT|UCON_TOINT|UCON_RXINT_TYPE_LEVEL)
266 #define UCON_TXINT_MASK   (UCON_TXMODE_MASK|UCON_TXINT_TYPE)
267 #define UCON_TXINT_ENABLE (UCON_TXMODE_INT|UCON_TXINT_TYPE_LEVEL)
268 
269 /* we don't want tx interrupt on debug port, but it is needed to
270    have transmitter active */
271 #define UCON_DEBUGPORT	  (UCON_RXINT_ENABLE|UCON_TXINT_ENABLE)
272 
273 
274 static inline void
275 __sscom_output_chunk(struct sscom_softc *sc, int ufstat)
276 {
277 	int n, space;
278 	bus_space_tag_t iot = sc->sc_iot;
279 	bus_space_handle_t ioh = sc->sc_ioh;
280 
281 	n = sc->sc_tbc;
282 	space = 16 - ((ufstat & UFSTAT_TXCOUNT) >> UFSTAT_TXCOUNT_SHIFT);
283 
284 	if (n > space)
285 		n = space;
286 
287 	if (n > 0) {
288 		bus_space_write_multi_1(iot, ioh, SSCOM_UTXH, sc->sc_tba, n);
289 		sc->sc_tbc -= n;
290 		sc->sc_tba += n;
291 	}
292 }
293 
294 static void
295 sscom_output_chunk(struct sscom_softc *sc)
296 {
297 	int ufstat = bus_space_read_2(sc->sc_iot, sc->sc_ioh, SSCOM_UFSTAT);
298 
299 	if (!(ufstat & UFSTAT_TXFULL))
300 		__sscom_output_chunk(sc, ufstat);
301 }
302 
303 int
304 sscomspeed(long speed, long frequency)
305 {
306 #define	divrnd(n, q)	(((n)*2/(q)+1)/2)	/* divide and round off */
307 
308 	int x, err;
309 
310 	if (speed <= 0)
311 		return -1;
312 	x = divrnd(frequency / 16, speed);
313 	if (x <= 0)
314 		return -1;
315 	err = divrnd(((quad_t)frequency) * 1000 / 16, speed * x) - 1000;
316 	if (err < 0)
317 		err = -err;
318 	if (err > SSCOM_TOLERANCE)
319 		return -1;
320 	return x-1;
321 
322 #undef	divrnd
323 }
324 
325 void sscomstatus (struct sscom_softc *, const char *);
326 
327 #ifdef SSCOM_DEBUG
328 int	sscom_debug = 0;
329 
330 void
331 sscomstatus(struct sscom_softc *sc, const char *str)
332 {
333 	struct tty *tp = sc->sc_tty;
334 	int umstat = bus_space_read_1(sc->sc_iot, sc->sc_iot, SSCOM_UMSTAT);
335 	int umcon = bus_space_read_1(sc->sc_iot, sc->sc_iot, SSCOM_UMCON);
336 
337 	printf("%s: %s %sclocal  %sdcd %sts_carr_on %sdtr %stx_stopped\n",
338 	    sc->sc_dev.dv_xname, str,
339 	    ISSET(tp->t_cflag, CLOCAL) ? "+" : "-",
340 	    "+",			/* DCD */
341 	    ISSET(tp->t_state, TS_CARR_ON) ? "+" : "-",
342 	    "+",			/* DTR */
343 	    sc->sc_tx_stopped ? "+" : "-");
344 
345 	printf("%s: %s %scrtscts %scts %sts_ttstop  %srts %xrx_flags\n",
346 	    sc->sc_dev.dv_xname, str,
347 	    ISSET(tp->t_cflag, CRTSCTS) ? "+" : "-",
348 	    ISSET(umstat, UMSTAT_CTS) ? "+" : "-",
349 	    ISSET(tp->t_state, TS_TTSTOP) ? "+" : "-",
350 	    ISSET(umcon, UMCON_RTS) ? "+" : "-",
351 	    sc->sc_rx_flags);
352 }
353 #else
354 #define sscom_debug  0
355 #endif
356 
357 static void
358 sscom_enable_debugport(struct sscom_softc *sc)
359 {
360 	int s;
361 
362 	/* Turn on line break interrupt, set carrier. */
363 	s = splserial();
364 	SSCOM_LOCK(sc);
365 	sc->sc_ucon = UCON_DEBUGPORT;
366 	bus_space_write_2(sc->sc_iot, sc->sc_ioh, SSCOM_UCON, sc->sc_ucon);
367 	sc->sc_umcon = UMCON_RTS|UMCON_DTR;
368 	sc->set_modem_control(sc);
369 	sscom_enable_rxint(sc);
370 	sscom_disable_txint(sc);
371 	SSCOM_UNLOCK(sc);
372 	splx(s);
373 }
374 
375 static void
376 sscom_set_modem_control(struct sscom_softc *sc)
377 {
378 	/* flob RTS */
379 	bus_space_write_1(sc->sc_iot, sc->sc_ioh,
380 	    SSCOM_UMCON, sc->sc_umcon & UMCON_HW_MASK);
381 	/* ignore DTR */
382 }
383 
384 static int
385 sscom_read_modem_status(struct sscom_softc *sc)
386 {
387 	int msts;
388 
389 	msts = bus_space_read_1(sc->sc_iot, sc->sc_ioh, SSCOM_UMSTAT);
390 
391 	/* DCD and DSR are always on */
392 	return (msts & UMSTAT_CTS) | MSTS_DCD | MSTS_DSR;
393 }
394 
395 void
396 sscom_attach_subr(struct sscom_softc *sc)
397 {
398 	int unit = sc->sc_unit;
399 	bus_space_tag_t iot = sc->sc_iot;
400 	bus_space_handle_t ioh = sc->sc_ioh;
401 	struct tty *tp;
402 
403 	callout_init(&sc->sc_diag_callout, 0);
404 #if (defined(MULTIPROCESSOR) || defined(LOCKDEBUG)) && defined(SSCOM_MPLOCK)
405 	simple_lock_init(&sc->sc_lock);
406 #endif
407 
408 	sc->sc_ucon = UCON_RXINT_ENABLE|UCON_TXINT_ENABLE;
409 
410 	/*
411 	 * set default for modem control hook
412 	 */
413 	if (sc->set_modem_control == NULL)
414 		sc->set_modem_control = sscom_set_modem_control;
415 	if (sc->read_modem_status == NULL)
416 		sc->read_modem_status = sscom_read_modem_status;
417 
418 	/* Disable interrupts before configuring the device. */
419 	sscom_disable_txrxint(sc);
420 
421 #ifdef KGDB
422 	/*
423 	 * Allow kgdb to "take over" this port.  If this is
424 	 * the kgdb device, it has exclusive use.
425 	 */
426 	if (unit == sscom_kgdb_unit) {
427 		SET(sc->sc_hwflags, SSCOM_HW_KGDB);
428 		sc->sc_ucon = UCON_DEBUGPORT;
429 	}
430 #endif
431 
432 	if (unit == sscomconsunit) {
433 		sscomconsattached = 1;
434 
435 		sscomconstag = iot;
436 		sscomconsioh = ioh;
437 
438 		/* Make sure the console is always "hardwired". */
439 		delay(1000);			/* XXX: wait for output to finish */
440 		SET(sc->sc_hwflags, SSCOM_HW_CONSOLE);
441 		SET(sc->sc_swflags, TIOCFLAG_SOFTCAR);
442 
443 		sc->sc_ucon = UCON_DEBUGPORT;
444 	}
445 
446 	bus_space_write_1(iot, ioh, SSCOM_UFCON,
447 	    UFCON_TXTRIGGER_8|UFCON_RXTRIGGER_8|UFCON_FIFO_ENABLE|
448 	    UFCON_TXFIFO_RESET|UFCON_RXFIFO_RESET);
449 
450 	bus_space_write_1(iot, ioh, SSCOM_UCON, sc->sc_ucon);
451 
452 #ifdef KGDB
453 	if (ISSET(sc->sc_hwflags, SSCOM_HW_KGDB)) {
454 		sscom_kgdb_attached = 1;
455 		printf("%s: kgdb\n", sc->sc_dev.dv_xname);
456 		sscom_enable_debugport(sc);
457 		return;
458 	}
459 #endif
460 
461 	tp = tty_alloc();
462 	tp->t_oproc = sscomstart;
463 	tp->t_param = sscomparam;
464 	tp->t_hwiflow = sscomhwiflow;
465 
466 	sc->sc_tty = tp;
467 	sc->sc_rbuf = malloc(sscom_rbuf_size << 1, M_DEVBUF, M_NOWAIT);
468 	sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
469 	sc->sc_rbavail = sscom_rbuf_size;
470 	if (sc->sc_rbuf == NULL) {
471 		printf("%s: unable to allocate ring buffer\n",
472 		    sc->sc_dev.dv_xname);
473 		return;
474 	}
475 	sc->sc_ebuf = sc->sc_rbuf + (sscom_rbuf_size << 1);
476 
477 	tty_attach(tp);
478 
479 	if (ISSET(sc->sc_hwflags, SSCOM_HW_CONSOLE)) {
480 		int maj;
481 
482 		/* locate the major number */
483 		maj = cdevsw_lookup_major(&sscom_cdevsw);
484 
485 		cn_tab->cn_dev = makedev(maj, device_unit(&sc->sc_dev));
486 
487 		printf("%s: console (major=%d)\n", sc->sc_dev.dv_xname, maj);
488 	}
489 
490 
491 	sc->sc_si = softint_establish(SOFTINT_SERIAL, sscomsoft, sc);
492 
493 #if NRND > 0 && defined(RND_COM)
494 	rnd_attach_source(&sc->rnd_source, sc->sc_dev.dv_xname,
495 			  RND_TYPE_TTY, 0);
496 #endif
497 
498 	/* if there are no enable/disable functions, assume the device
499 	   is always enabled */
500 
501 	if (ISSET(sc->sc_hwflags, SSCOM_HW_CONSOLE))
502 		sscom_enable_debugport(sc);
503 	else
504 		sscom_disable_txrxint(sc);
505 
506 	SET(sc->sc_hwflags, SSCOM_HW_DEV_OK);
507 }
508 
509 int
510 sscom_detach(device_t self, int flags)
511 {
512 	struct sscom_softc *sc = device_private(self);
513 
514 	if (sc->sc_hwflags & (SSCOM_HW_CONSOLE|SSCOM_HW_KGDB))
515 		return EBUSY;
516 
517 	return 0;
518 }
519 
520 int
521 sscom_activate(device_t self, enum devact act)
522 {
523 #ifdef notyet
524 	struct sscom_softc *sc = device_private(self);
525 #endif
526 
527 	switch (act) {
528 	case DVACT_DEACTIVATE:
529 #ifdef notyet
530 		sc->enabled = 0;
531 #endif
532 		return 0;
533 	default:
534 		return EOPNOTSUPP;
535 	}
536 }
537 
538 void
539 sscom_shutdown(struct sscom_softc *sc)
540 {
541 #ifdef notyet
542 	struct tty *tp = sc->sc_tty;
543 	int s;
544 
545 	s = splserial();
546 	SSCOM_LOCK(sc);
547 
548 	/* If we were asserting flow control, then deassert it. */
549 	SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
550 	sscom_hwiflow(sc);
551 
552 	/* Clear any break condition set with TIOCSBRK. */
553 	sscom_break(sc, 0);
554 
555 	/*
556 	 * Hang up if necessary.  Wait a bit, so the other side has time to
557 	 * notice even if we immediately open the port again.
558 	 * Avoid tsleeping above splhigh().
559 	 */
560 	if (ISSET(tp->t_cflag, HUPCL)) {
561 		sscom_modem(sc, 0);
562 		SSCOM_UNLOCK(sc);
563 		splx(s);
564 		/* XXX tsleep will only timeout */
565 		(void) tsleep(sc, TTIPRI, ttclos, hz);
566 		s = splserial();
567 		SSCOM_LOCK(sc);
568 	}
569 
570 	if (ISSET(sc->sc_hwflags, SSCOM_HW_CONSOLE))
571 		/* interrupt on break */
572 		sc->sc_ucon = UCON_DEBUGPORT;
573 	else
574 		sc->sc_ucon = 0;
575 	bus_space_write_2(sc->sc_iot, sc->sc_ioh, SSCOM_UCON, sc->sc_ucon);
576 
577 #ifdef DIAGNOSTIC
578 	if (!sc->enabled)
579 		panic("sscom_shutdown: not enabled?");
580 #endif
581 	sc->enabled = 0;
582 	SSCOM_UNLOCK(sc);
583 	splx(s);
584 #endif
585 }
586 
587 int
588 sscomopen(dev_t dev, int flag, int mode, struct lwp *l)
589 {
590 	struct sscom_softc *sc;
591 	struct tty *tp;
592 	int s, s2;
593 	int error;
594 
595 	sc = device_lookup_private(&sscom_cd, SSCOMUNIT(dev));
596 	if (sc == NULL || !ISSET(sc->sc_hwflags, SSCOM_HW_DEV_OK) ||
597 		sc->sc_rbuf == NULL)
598 		return ENXIO;
599 
600 	if (!device_is_active(&sc->sc_dev))
601 		return ENXIO;
602 
603 #ifdef KGDB
604 	/*
605 	 * If this is the kgdb port, no other use is permitted.
606 	 */
607 	if (ISSET(sc->sc_hwflags, SSCOM_HW_KGDB))
608 		return EBUSY;
609 #endif
610 
611 	tp = sc->sc_tty;
612 
613 	if (kauth_authorize_device_tty(l->l_cred, KAUTH_DEVICE_TTY_OPEN, tp))
614 		return (EBUSY);
615 
616 	s = spltty();
617 
618 	/*
619 	 * Do the following iff this is a first open.
620 	 */
621 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
622 		struct termios t;
623 
624 		tp->t_dev = dev;
625 
626 		s2 = splserial();
627 		SSCOM_LOCK(sc);
628 
629 		/* Turn on interrupts. */
630 		sscom_enable_txrxint(sc);
631 
632 		/* Fetch the current modem control status, needed later. */
633 		sc->sc_msts = sc->read_modem_status(sc);
634 
635 #if 0
636 		/* Clear PPS capture state on first open. */
637 		sc->sc_ppsmask = 0;
638 		sc->ppsparam.mode = 0;
639 #endif
640 
641 		SSCOM_UNLOCK(sc);
642 		splx(s2);
643 
644 		/*
645 		 * Initialize the termios status to the defaults.  Add in the
646 		 * sticky bits from TIOCSFLAGS.
647 		 */
648 		t.c_ispeed = 0;
649 		if (ISSET(sc->sc_hwflags, SSCOM_HW_CONSOLE)) {
650 			t.c_ospeed = sscomconsrate;
651 			t.c_cflag = sscomconscflag;
652 		} else {
653 			t.c_ospeed = TTYDEF_SPEED;
654 			t.c_cflag = TTYDEF_CFLAG;
655 		}
656 		if (ISSET(sc->sc_swflags, TIOCFLAG_CLOCAL))
657 			SET(t.c_cflag, CLOCAL);
658 		if (ISSET(sc->sc_swflags, TIOCFLAG_CRTSCTS))
659 			SET(t.c_cflag, CRTSCTS);
660 		if (ISSET(sc->sc_swflags, TIOCFLAG_MDMBUF))
661 			SET(t.c_cflag, MDMBUF);
662 		/* Make sure sscomparam() will do something. */
663 		tp->t_ospeed = 0;
664 		(void) sscomparam(tp, &t);
665 		tp->t_iflag = TTYDEF_IFLAG;
666 		tp->t_oflag = TTYDEF_OFLAG;
667 		tp->t_lflag = TTYDEF_LFLAG;
668 		ttychars(tp);
669 		ttsetwater(tp);
670 
671 		s2 = splserial();
672 		SSCOM_LOCK(sc);
673 
674 		/*
675 		 * Turn on DTR.  We must always do this, even if carrier is not
676 		 * present, because otherwise we'd have to use TIOCSDTR
677 		 * immediately after setting CLOCAL, which applications do not
678 		 * expect.  We always assert DTR while the device is open
679 		 * unless explicitly requested to deassert it.
680 		 */
681 		sscom_modem(sc, 1);
682 
683 		/* Clear the input ring, and unblock. */
684 		sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
685 		sc->sc_rbavail = sscom_rbuf_size;
686 		sscom_iflush(sc);
687 		CLR(sc->sc_rx_flags, RX_ANY_BLOCK);
688 		sscom_hwiflow(sc);
689 
690 		if (sscom_debug)
691 			sscomstatus(sc, "sscomopen  ");
692 
693 		SSCOM_UNLOCK(sc);
694 		splx(s2);
695 	}
696 
697 	splx(s);
698 
699 	error = ttyopen(tp, SSCOMDIALOUT(dev), ISSET(flag, O_NONBLOCK));
700 	if (error)
701 		goto bad;
702 
703 	error = (*tp->t_linesw->l_open)(dev, tp);
704 	if (error)
705 		goto bad;
706 
707 	return 0;
708 
709 bad:
710 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
711 		/*
712 		 * We failed to open the device, and nobody else had it opened.
713 		 * Clean up the state as appropriate.
714 		 */
715 		sscom_shutdown(sc);
716 	}
717 
718 	return error;
719 }
720 
721 int
722 sscomclose(dev_t dev, int flag, int mode, struct lwp *l)
723 {
724 	struct sscom_softc *sc = device_lookup_private(&sscom_cd, SSCOMUNIT(dev));
725 	struct tty *tp = sc->sc_tty;
726 
727 	/* XXX This is for cons.c. */
728 	if (!ISSET(tp->t_state, TS_ISOPEN))
729 		return 0;
730 
731 	(*tp->t_linesw->l_close)(tp, flag);
732 	ttyclose(tp);
733 
734 	if (SSCOM_ISALIVE(sc) == 0)
735 		return 0;
736 
737 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
738 		/*
739 		 * Although we got a last close, the device may still be in
740 		 * use; e.g. if this was the dialout node, and there are still
741 		 * processes waiting for carrier on the non-dialout node.
742 		 */
743 		sscom_shutdown(sc);
744 	}
745 
746 	return 0;
747 }
748 
749 int
750 sscomread(dev_t dev, struct uio *uio, int flag)
751 {
752 	struct sscom_softc *sc = device_lookup_private(&sscom_cd, SSCOMUNIT(dev));
753 	struct tty *tp = sc->sc_tty;
754 
755 	if (SSCOM_ISALIVE(sc) == 0)
756 		return EIO;
757 
758 	return (*tp->t_linesw->l_read)(tp, uio, flag);
759 }
760 
761 int
762 sscomwrite(dev_t dev, struct uio *uio, int flag)
763 {
764 	struct sscom_softc *sc = device_lookup_private(&sscom_cd, SSCOMUNIT(dev));
765 	struct tty *tp = sc->sc_tty;
766 
767 	if (SSCOM_ISALIVE(sc) == 0)
768 		return EIO;
769 
770 	return (*tp->t_linesw->l_write)(tp, uio, flag);
771 }
772 
773 int
774 sscompoll(dev_t dev, int events, struct lwp *l)
775 {
776 	struct sscom_softc *sc = device_lookup_private(&sscom_cd, SSCOMUNIT(dev));
777 	struct tty *tp = sc->sc_tty;
778 
779 	if (SSCOM_ISALIVE(sc) == 0)
780 		return EIO;
781 
782 	return (*tp->t_linesw->l_poll)(tp, events, l);
783 }
784 
785 struct tty *
786 sscomtty(dev_t dev)
787 {
788 	struct sscom_softc *sc = device_lookup_private(&sscom_cd, SSCOMUNIT(dev));
789 	struct tty *tp = sc->sc_tty;
790 
791 	return tp;
792 }
793 
794 int
795 sscomioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
796 {
797 	struct sscom_softc *sc = device_lookup_private(&sscom_cd, SSCOMUNIT(dev));
798 	struct tty *tp = sc->sc_tty;
799 	int error;
800 	int s;
801 
802 	if (SSCOM_ISALIVE(sc) == 0)
803 		return EIO;
804 
805 	error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, l);
806 	if (error != EPASSTHROUGH)
807 		return error;
808 
809 	error = ttioctl(tp, cmd, data, flag, l);
810 	if (error != EPASSTHROUGH)
811 		return error;
812 
813 	error = 0;
814 
815 	s = splserial();
816 	SSCOM_LOCK(sc);
817 
818 	switch (cmd) {
819 	case TIOCSBRK:
820 		sscom_break(sc, 1);
821 		break;
822 
823 	case TIOCCBRK:
824 		sscom_break(sc, 0);
825 		break;
826 
827 	case TIOCSDTR:
828 		sscom_modem(sc, 1);
829 		break;
830 
831 	case TIOCCDTR:
832 		sscom_modem(sc, 0);
833 		break;
834 
835 	case TIOCGFLAGS:
836 		*(int *)data = sc->sc_swflags;
837 		break;
838 
839 	case TIOCSFLAGS:
840 		error = kauth_authorize_device_tty(l->l_cred,
841 		    KAUTH_DEVICE_TTY_PRIVSET, tp);
842 		if (error)
843 			break;
844 		sc->sc_swflags = *(int *)data;
845 		break;
846 
847 	case TIOCMSET:
848 	case TIOCMBIS:
849 	case TIOCMBIC:
850 		tiocm_to_sscom(sc, cmd, *(int *)data);
851 		break;
852 
853 	case TIOCMGET:
854 		*(int *)data = sscom_to_tiocm(sc);
855 		break;
856 
857 	default:
858 		error = EPASSTHROUGH;
859 		break;
860 	}
861 
862 	SSCOM_UNLOCK(sc);
863 	splx(s);
864 
865 	if (sscom_debug)
866 		sscomstatus(sc, "sscomioctl ");
867 
868 	return error;
869 }
870 
871 integrate void
872 sscom_schedrx(struct sscom_softc *sc)
873 {
874 
875 	sc->sc_rx_ready = 1;
876 
877 	/* Wake up the poller. */
878 	softint_schedule(sc->sc_si);
879 }
880 
881 static void
882 sscom_break(struct sscom_softc *sc, int onoff)
883 {
884 
885 	if (onoff)
886 		SET(sc->sc_ucon, UCON_SBREAK);
887 	else
888 		CLR(sc->sc_ucon, UCON_SBREAK);
889 
890 	if (!sc->sc_heldchange) {
891 		if (sc->sc_tx_busy) {
892 			sc->sc_heldtbc = sc->sc_tbc;
893 			sc->sc_tbc = 0;
894 			sc->sc_heldchange = 1;
895 		} else
896 			sscom_loadchannelregs(sc);
897 	}
898 }
899 
900 static void
901 sscom_modem(struct sscom_softc *sc, int onoff)
902 {
903 	if (onoff)
904 		SET(sc->sc_umcon, UMCON_DTR);
905 	else
906 		CLR(sc->sc_umcon, UMCON_DTR);
907 
908 	if (!sc->sc_heldchange) {
909 		if (sc->sc_tx_busy) {
910 			sc->sc_heldtbc = sc->sc_tbc;
911 			sc->sc_tbc = 0;
912 			sc->sc_heldchange = 1;
913 		} else
914 			sscom_loadchannelregs(sc);
915 	}
916 }
917 
918 static void
919 tiocm_to_sscom(struct sscom_softc *sc, u_long how, int ttybits)
920 {
921 	u_char sscombits;
922 
923 	sscombits = 0;
924 	if (ISSET(ttybits, TIOCM_DTR))
925 		sscombits = UMCON_DTR;
926 	if (ISSET(ttybits, TIOCM_RTS))
927 		SET(sscombits, UMCON_RTS);
928 
929 	switch (how) {
930 	case TIOCMBIC:
931 		CLR(sc->sc_umcon, sscombits);
932 		break;
933 
934 	case TIOCMBIS:
935 		SET(sc->sc_umcon, sscombits);
936 		break;
937 
938 	case TIOCMSET:
939 		CLR(sc->sc_umcon, UMCON_DTR);
940 		SET(sc->sc_umcon, sscombits);
941 		break;
942 	}
943 
944 	if (!sc->sc_heldchange) {
945 		if (sc->sc_tx_busy) {
946 			sc->sc_heldtbc = sc->sc_tbc;
947 			sc->sc_tbc = 0;
948 			sc->sc_heldchange = 1;
949 		} else
950 			sscom_loadchannelregs(sc);
951 	}
952 }
953 
954 static int
955 sscom_to_tiocm(struct sscom_softc *sc)
956 {
957 	u_char sscombits;
958 	int ttybits = 0;
959 
960 	sscombits = sc->sc_umcon;
961 #if 0
962 	if (ISSET(sscombits, MCR_DTR))
963 		SET(ttybits, TIOCM_DTR);
964 #endif
965 	if (ISSET(sscombits, UMCON_RTS))
966 		SET(ttybits, TIOCM_RTS);
967 
968 	sscombits = sc->sc_msts;
969 	if (ISSET(sscombits, MSTS_DCD))
970 		SET(ttybits, TIOCM_CD);
971 	if (ISSET(sscombits, MSTS_DSR))
972 		SET(ttybits, TIOCM_DSR);
973 	if (ISSET(sscombits, MSTS_CTS))
974 		SET(ttybits, TIOCM_CTS);
975 
976 	if (sc->sc_ucon != 0)
977 		SET(ttybits, TIOCM_LE);
978 
979 	return ttybits;
980 }
981 
982 static int
983 cflag2lcr(tcflag_t cflag)
984 {
985 	u_char lcr = ULCON_PARITY_NONE;
986 
987 	switch (cflag & (PARENB|PARODD)) {
988 	case PARENB|PARODD: lcr = ULCON_PARITY_ODD; break;
989 	case PARENB: lcr = ULCON_PARITY_EVEN;
990 	}
991 
992 	switch (ISSET(cflag, CSIZE)) {
993 	case CS5:
994 		SET(lcr, ULCON_LENGTH_5);
995 		break;
996 	case CS6:
997 		SET(lcr, ULCON_LENGTH_6);
998 		break;
999 	case CS7:
1000 		SET(lcr, ULCON_LENGTH_7);
1001 		break;
1002 	case CS8:
1003 		SET(lcr, ULCON_LENGTH_8);
1004 		break;
1005 	}
1006 	if (ISSET(cflag, CSTOPB))
1007 		SET(lcr, ULCON_STOP);
1008 
1009 	return lcr;
1010 }
1011 
1012 int
1013 sscomparam(struct tty *tp, struct termios *t)
1014 {
1015 	struct sscom_softc *sc = device_lookup_private(&sscom_cd, SSCOMUNIT(tp->t_dev));
1016 	int ospeed;
1017 	u_char lcr;
1018 	int s;
1019 
1020 	if (SSCOM_ISALIVE(sc) == 0)
1021 		return EIO;
1022 
1023 	ospeed = sscomspeed(t->c_ospeed, sc->sc_frequency);
1024 
1025 	/* Check requested parameters. */
1026 	if (ospeed < 0)
1027 		return EINVAL;
1028 	if (t->c_ispeed && t->c_ispeed != t->c_ospeed)
1029 		return EINVAL;
1030 
1031 	/*
1032 	 * For the console, always force CLOCAL and !HUPCL, so that the port
1033 	 * is always active.
1034 	 */
1035 	if (ISSET(sc->sc_swflags, TIOCFLAG_SOFTCAR) ||
1036 	    ISSET(sc->sc_hwflags, SSCOM_HW_CONSOLE)) {
1037 		SET(t->c_cflag, CLOCAL);
1038 		CLR(t->c_cflag, HUPCL);
1039 	}
1040 
1041 	/*
1042 	 * If there were no changes, don't do anything.  This avoids dropping
1043 	 * input and improves performance when all we did was frob things like
1044 	 * VMIN and VTIME.
1045 	 */
1046 	if (tp->t_ospeed == t->c_ospeed &&
1047 	    tp->t_cflag == t->c_cflag)
1048 		return 0;
1049 
1050 	lcr = cflag2lcr(t->c_cflag);
1051 
1052 	s = splserial();
1053 	SSCOM_LOCK(sc);
1054 
1055 	sc->sc_ulcon = lcr;
1056 
1057 	/*
1058 	 * If we're not in a mode that assumes a connection is present, then
1059 	 * ignore carrier changes.
1060 	 */
1061 	if (ISSET(t->c_cflag, CLOCAL | MDMBUF))
1062 		sc->sc_msr_dcd = 0;
1063 	else
1064 		sc->sc_msr_dcd = MSTS_DCD;
1065 
1066 	/*
1067 	 * Set the flow control pins depending on the current flow control
1068 	 * mode.
1069 	 */
1070 	if (ISSET(t->c_cflag, CRTSCTS)) {
1071 		sc->sc_mcr_dtr = UMCON_DTR;
1072 		sc->sc_mcr_rts = UMCON_RTS;
1073 		sc->sc_msr_cts = MSTS_CTS;
1074 	}
1075 	else if (ISSET(t->c_cflag, MDMBUF)) {
1076 		/*
1077 		 * For DTR/DCD flow control, make sure we don't toggle DTR for
1078 		 * carrier detection.
1079 		 */
1080 		sc->sc_mcr_dtr = 0;
1081 		sc->sc_mcr_rts = UMCON_DTR;
1082 		sc->sc_msr_cts = MSTS_DCD;
1083 	}
1084 	else {
1085 		/*
1086 		 * If no flow control, then always set RTS.  This will make
1087 		 * the other side happy if it mistakenly thinks we're doing
1088 		 * RTS/CTS flow control.
1089 		 */
1090 		sc->sc_mcr_dtr = UMCON_DTR | UMCON_RTS;
1091 		sc->sc_mcr_rts = 0;
1092 		sc->sc_msr_cts = 0;
1093 		if (ISSET(sc->sc_umcon, UMCON_DTR))
1094 			SET(sc->sc_umcon, UMCON_RTS);
1095 		else
1096 			CLR(sc->sc_umcon, UMCON_RTS);
1097 	}
1098 	sc->sc_msr_mask = sc->sc_msr_cts | sc->sc_msr_dcd;
1099 
1100 	if (ospeed == 0)
1101 		CLR(sc->sc_umcon, sc->sc_mcr_dtr);
1102 	else
1103 		SET(sc->sc_umcon, sc->sc_mcr_dtr);
1104 
1105 	sc->sc_ubrdiv = ospeed;
1106 
1107 	/* And copy to tty. */
1108 	tp->t_ispeed = 0;
1109 	tp->t_ospeed = t->c_ospeed;
1110 	tp->t_cflag = t->c_cflag;
1111 
1112 	if (!sc->sc_heldchange) {
1113 		if (sc->sc_tx_busy) {
1114 			sc->sc_heldtbc = sc->sc_tbc;
1115 			sc->sc_tbc = 0;
1116 			sc->sc_heldchange = 1;
1117 		} else
1118 			sscom_loadchannelregs(sc);
1119 	}
1120 
1121 	if (!ISSET(t->c_cflag, CHWFLOW)) {
1122 		/* Disable the high water mark. */
1123 		sc->sc_r_hiwat = 0;
1124 		sc->sc_r_lowat = 0;
1125 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
1126 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1127 			sscom_schedrx(sc);
1128 		}
1129 		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED)) {
1130 			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED);
1131 			sscom_hwiflow(sc);
1132 		}
1133 	} else {
1134 		sc->sc_r_hiwat = sscom_rbuf_hiwat;
1135 		sc->sc_r_lowat = sscom_rbuf_lowat;
1136 	}
1137 
1138 	SSCOM_UNLOCK(sc);
1139 	splx(s);
1140 
1141 	/*
1142 	 * Update the tty layer's idea of the carrier bit, in case we changed
1143 	 * CLOCAL or MDMBUF.  We don't hang up here; we only do that by
1144 	 * explicit request.
1145 	 */
1146 	(void) (*tp->t_linesw->l_modem)(tp, ISSET(sc->sc_msts, MSTS_DCD));
1147 
1148 	if (sscom_debug)
1149 		sscomstatus(sc, "sscomparam ");
1150 
1151 	if (!ISSET(t->c_cflag, CHWFLOW)) {
1152 		if (sc->sc_tx_stopped) {
1153 			sc->sc_tx_stopped = 0;
1154 			sscomstart(tp);
1155 		}
1156 	}
1157 
1158 	return 0;
1159 }
1160 
1161 static void
1162 sscom_iflush(struct sscom_softc *sc)
1163 {
1164 	bus_space_tag_t iot = sc->sc_iot;
1165 	bus_space_handle_t ioh = sc->sc_ioh;
1166 	int timo;
1167 
1168 
1169 	timo = 50000;
1170 	/* flush any pending I/O */
1171 	while ( sscom_rxrdy(iot, ioh) && --timo)
1172 		(void)sscom_getc(iot,ioh);
1173 #ifdef DIAGNOSTIC
1174 	if (!timo)
1175 		printf("%s: sscom_iflush timeout\n", sc->sc_dev.dv_xname);
1176 #endif
1177 }
1178 
1179 static void
1180 sscom_loadchannelregs(struct sscom_softc *sc)
1181 {
1182 	bus_space_tag_t iot = sc->sc_iot;
1183 	bus_space_handle_t ioh = sc->sc_ioh;
1184 
1185 	/* XXXXX necessary? */
1186 	sscom_iflush(sc);
1187 
1188 	bus_space_write_2(iot, ioh, SSCOM_UCON, 0);
1189 
1190 #if 0
1191 	if (ISSET(sc->sc_hwflags, COM_HW_FLOW)) {
1192 		bus_space_write_1(iot, ioh, com_lcr, LCR_EERS);
1193 		bus_space_write_1(iot, ioh, com_efr, sc->sc_efr);
1194 	}
1195 #endif
1196 
1197 	bus_space_write_2(iot, ioh, SSCOM_UBRDIV, sc->sc_ubrdiv);
1198 	bus_space_write_1(iot, ioh, SSCOM_ULCON, sc->sc_ulcon);
1199 	sc->set_modem_control(sc);
1200 	bus_space_write_2(iot, ioh, SSCOM_UCON, sc->sc_ucon);
1201 }
1202 
1203 static int
1204 sscomhwiflow(struct tty *tp, int block)
1205 {
1206 	struct sscom_softc *sc = device_lookup_private(&sscom_cd, SSCOMUNIT(tp->t_dev));
1207 	int s;
1208 
1209 	if (SSCOM_ISALIVE(sc) == 0)
1210 		return 0;
1211 
1212 	if (sc->sc_mcr_rts == 0)
1213 		return 0;
1214 
1215 	s = splserial();
1216 	SSCOM_LOCK(sc);
1217 
1218 	if (block) {
1219 		if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1220 			SET(sc->sc_rx_flags, RX_TTY_BLOCKED);
1221 			sscom_hwiflow(sc);
1222 		}
1223 	} else {
1224 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
1225 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1226 			sscom_schedrx(sc);
1227 		}
1228 		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1229 			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED);
1230 			sscom_hwiflow(sc);
1231 		}
1232 	}
1233 
1234 	SSCOM_UNLOCK(sc);
1235 	splx(s);
1236 	return 1;
1237 }
1238 
1239 /*
1240  * (un)block input via hw flowcontrol
1241  */
1242 static void
1243 sscom_hwiflow(struct sscom_softc *sc)
1244 {
1245 	if (sc->sc_mcr_rts == 0)
1246 		return;
1247 
1248 	if (ISSET(sc->sc_rx_flags, RX_ANY_BLOCK)) {
1249 		CLR(sc->sc_umcon, sc->sc_mcr_rts);
1250 		CLR(sc->sc_mcr_active, sc->sc_mcr_rts);
1251 	} else {
1252 		SET(sc->sc_umcon, sc->sc_mcr_rts);
1253 		SET(sc->sc_mcr_active, sc->sc_mcr_rts);
1254 	}
1255 	sc->set_modem_control(sc);
1256 }
1257 
1258 
1259 void
1260 sscomstart(struct tty *tp)
1261 {
1262 	struct sscom_softc *sc = device_lookup_private(&sscom_cd, SSCOMUNIT(tp->t_dev));
1263 	int s;
1264 
1265 	if (SSCOM_ISALIVE(sc) == 0)
1266 		return;
1267 
1268 	s = spltty();
1269 	if (ISSET(tp->t_state, TS_BUSY | TS_TIMEOUT | TS_TTSTOP))
1270 		goto out;
1271 	if (sc->sc_tx_stopped)
1272 		goto out;
1273 	if (!ttypull(tp))
1274 		goto out;
1275 
1276 	/* Grab the first contiguous region of buffer space. */
1277 	{
1278 		u_char *tba;
1279 		int tbc;
1280 
1281 		tba = tp->t_outq.c_cf;
1282 		tbc = ndqb(&tp->t_outq, 0);
1283 
1284 		(void)splserial();
1285 		SSCOM_LOCK(sc);
1286 
1287 		sc->sc_tba = tba;
1288 		sc->sc_tbc = tbc;
1289 	}
1290 
1291 	SET(tp->t_state, TS_BUSY);
1292 	sc->sc_tx_busy = 1;
1293 
1294 	/* Output the first chunk of the contiguous buffer. */
1295 	sscom_output_chunk(sc);
1296 
1297 	/* Enable transmit completion interrupts if necessary. */
1298 	if ((sc->sc_hwflags & SSCOM_HW_TXINT) == 0)
1299 		sscom_enable_txint(sc);
1300 
1301 	SSCOM_UNLOCK(sc);
1302 out:
1303 	splx(s);
1304 	return;
1305 }
1306 
1307 /*
1308  * Stop output on a line.
1309  */
1310 void
1311 sscomstop(struct tty *tp, int flag)
1312 {
1313 	struct sscom_softc *sc = device_lookup_private(&sscom_cd, SSCOMUNIT(tp->t_dev));
1314 	int s;
1315 
1316 	s = splserial();
1317 	SSCOM_LOCK(sc);
1318 	if (ISSET(tp->t_state, TS_BUSY)) {
1319 		/* Stop transmitting at the next chunk. */
1320 		sc->sc_tbc = 0;
1321 		sc->sc_heldtbc = 0;
1322 		if (!ISSET(tp->t_state, TS_TTSTOP))
1323 			SET(tp->t_state, TS_FLUSH);
1324 	}
1325 	SSCOM_UNLOCK(sc);
1326 	splx(s);
1327 }
1328 
1329 void
1330 sscomdiag(void *arg)
1331 {
1332 	struct sscom_softc *sc = arg;
1333 	int overflows, floods;
1334 	int s;
1335 
1336 	s = splserial();
1337 	SSCOM_LOCK(sc);
1338 	overflows = sc->sc_overflows;
1339 	sc->sc_overflows = 0;
1340 	floods = sc->sc_floods;
1341 	sc->sc_floods = 0;
1342 	sc->sc_errors = 0;
1343 	SSCOM_UNLOCK(sc);
1344 	splx(s);
1345 
1346 	log(LOG_WARNING, "%s: %d silo overflow%s, %d ibuf flood%s\n",
1347 	    sc->sc_dev.dv_xname,
1348 	    overflows, overflows == 1 ? "" : "s",
1349 	    floods, floods == 1 ? "" : "s");
1350 }
1351 
1352 integrate void
1353 sscom_rxsoft(struct sscom_softc *sc, struct tty *tp)
1354 {
1355 	int (*rint) (int, struct tty *) = tp->t_linesw->l_rint;
1356 	u_char *get, *end;
1357 	u_int cc, scc;
1358 	u_char rsr;
1359 	int code;
1360 	int s;
1361 
1362 	end = sc->sc_ebuf;
1363 	get = sc->sc_rbget;
1364 	scc = cc = sscom_rbuf_size - sc->sc_rbavail;
1365 
1366 	if (cc == sscom_rbuf_size) {
1367 		sc->sc_floods++;
1368 		if (sc->sc_errors++ == 0)
1369 			callout_reset(&sc->sc_diag_callout, 60 * hz,
1370 			    sscomdiag, sc);
1371 	}
1372 
1373 	while (cc) {
1374 		code = get[0];
1375 		rsr = get[1];
1376 		if (rsr) {
1377 			if (ISSET(rsr, UERSTAT_OVERRUN)) {
1378 				sc->sc_overflows++;
1379 				if (sc->sc_errors++ == 0)
1380 					callout_reset(&sc->sc_diag_callout,
1381 					    60 * hz, sscomdiag, sc);
1382 			}
1383 			if (ISSET(rsr, UERSTAT_BREAK | UERSTAT_FRAME))
1384 				SET(code, TTY_FE);
1385 			if (ISSET(rsr, UERSTAT_PARITY))
1386 				SET(code, TTY_PE);
1387 		}
1388 		if ((*rint)(code, tp) == -1) {
1389 			/*
1390 			 * The line discipline's buffer is out of space.
1391 			 */
1392 			if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1393 				/*
1394 				 * We're either not using flow control, or the
1395 				 * line discipline didn't tell us to block for
1396 				 * some reason.  Either way, we have no way to
1397 				 * know when there's more space available, so
1398 				 * just drop the rest of the data.
1399 				 */
1400 				get += cc << 1;
1401 				if (get >= end)
1402 					get -= sscom_rbuf_size << 1;
1403 				cc = 0;
1404 			} else {
1405 				/*
1406 				 * Don't schedule any more receive processing
1407 				 * until the line discipline tells us there's
1408 				 * space available (through sscomhwiflow()).
1409 				 * Leave the rest of the data in the input
1410 				 * buffer.
1411 				 */
1412 				SET(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1413 			}
1414 			break;
1415 		}
1416 		get += 2;
1417 		if (get >= end)
1418 			get = sc->sc_rbuf;
1419 		cc--;
1420 	}
1421 
1422 	if (cc != scc) {
1423 		sc->sc_rbget = get;
1424 		s = splserial();
1425 		SSCOM_LOCK(sc);
1426 
1427 		cc = sc->sc_rbavail += scc - cc;
1428 		/* Buffers should be ok again, release possible block. */
1429 		if (cc >= sc->sc_r_lowat) {
1430 			if (ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
1431 				CLR(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
1432 				sscom_enable_rxint(sc);
1433 				sc->sc_ucon |= UCON_ERRINT;
1434 				bus_space_write_2(sc->sc_iot, sc->sc_ioh, SSCOM_UCON,
1435 						  sc->sc_ucon);
1436 
1437 			}
1438 			if (ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED)) {
1439 				CLR(sc->sc_rx_flags, RX_IBUF_BLOCKED);
1440 				sscom_hwiflow(sc);
1441 			}
1442 		}
1443 		SSCOM_UNLOCK(sc);
1444 		splx(s);
1445 	}
1446 }
1447 
1448 integrate void
1449 sscom_txsoft(struct sscom_softc *sc, struct tty *tp)
1450 {
1451 
1452 	CLR(tp->t_state, TS_BUSY);
1453 	if (ISSET(tp->t_state, TS_FLUSH))
1454 		CLR(tp->t_state, TS_FLUSH);
1455 	else
1456 		ndflush(&tp->t_outq, (int)(sc->sc_tba - tp->t_outq.c_cf));
1457 	(*tp->t_linesw->l_start)(tp);
1458 }
1459 
1460 integrate void
1461 sscom_stsoft(struct sscom_softc *sc, struct tty *tp)
1462 {
1463 	u_char msr, delta;
1464 	int s;
1465 
1466 	s = splserial();
1467 	SSCOM_LOCK(sc);
1468 	msr = sc->sc_msts;
1469 	delta = sc->sc_msr_delta;
1470 	sc->sc_msr_delta = 0;
1471 	SSCOM_UNLOCK(sc);
1472 	splx(s);
1473 
1474 	if (ISSET(delta, sc->sc_msr_dcd)) {
1475 		/*
1476 		 * Inform the tty layer that carrier detect changed.
1477 		 */
1478 		(void) (*tp->t_linesw->l_modem)(tp, ISSET(msr, MSTS_DCD));
1479 	}
1480 
1481 	if (ISSET(delta, sc->sc_msr_cts)) {
1482 		/* Block or unblock output according to flow control. */
1483 		if (ISSET(msr, sc->sc_msr_cts)) {
1484 			sc->sc_tx_stopped = 0;
1485 			(*tp->t_linesw->l_start)(tp);
1486 		} else {
1487 			sc->sc_tx_stopped = 1;
1488 		}
1489 	}
1490 
1491 	if (sscom_debug)
1492 		sscomstatus(sc, "sscom_stsoft");
1493 }
1494 
1495 void
1496 sscomsoft(void *arg)
1497 {
1498 	struct sscom_softc *sc = arg;
1499 	struct tty *tp;
1500 
1501 	if (SSCOM_ISALIVE(sc) == 0)
1502 		return;
1503 
1504 	{
1505 		tp = sc->sc_tty;
1506 
1507 		if (sc->sc_rx_ready) {
1508 			sc->sc_rx_ready = 0;
1509 			sscom_rxsoft(sc, tp);
1510 		}
1511 
1512 		if (sc->sc_st_check) {
1513 			sc->sc_st_check = 0;
1514 			sscom_stsoft(sc, tp);
1515 		}
1516 
1517 		if (sc->sc_tx_done) {
1518 			sc->sc_tx_done = 0;
1519 			sscom_txsoft(sc, tp);
1520 		}
1521 	}
1522 }
1523 
1524 
1525 int
1526 sscomrxintr(void *arg)
1527 {
1528 	struct sscom_softc *sc = arg;
1529 	bus_space_tag_t iot = sc->sc_iot;
1530 	bus_space_handle_t ioh = sc->sc_ioh;
1531 	u_char *put, *end;
1532 	u_int cc;
1533 
1534 	if (SSCOM_ISALIVE(sc) == 0)
1535 		return 0;
1536 
1537 	SSCOM_LOCK(sc);
1538 
1539 	end = sc->sc_ebuf;
1540 	put = sc->sc_rbput;
1541 	cc = sc->sc_rbavail;
1542 
1543 	do {
1544 		u_char	msts, delta;
1545 		u_char  uerstat;
1546 		uint16_t ufstat;
1547 
1548 		ufstat = bus_space_read_2(iot, ioh, SSCOM_UFSTAT);
1549 
1550 		/* XXX: break interrupt with no character? */
1551 
1552 		if ( (ufstat & (UFSTAT_RXCOUNT|UFSTAT_RXFULL)) &&
1553 		    !ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
1554 
1555 			while (cc > 0) {
1556 				int cn_trapped = 0;
1557 
1558 				/* get status and received character.
1559 				   read status register first */
1560 				uerstat = sscom_geterr(iot, ioh);
1561 				put[0] = sscom_getc(iot, ioh);
1562 
1563 				if (ISSET(uerstat, UERSTAT_BREAK)) {
1564 					int con_trapped = 0;
1565 					cn_check_magic(sc->sc_tty->t_dev,
1566 					    CNC_BREAK, sscom_cnm_state);
1567 					if (con_trapped)
1568 						continue;
1569 #if defined(KGDB)
1570 					if (ISSET(sc->sc_hwflags,
1571 					    SSCOM_HW_KGDB)) {
1572 						kgdb_connect(1);
1573 						continue;
1574 					}
1575 #endif
1576 				}
1577 
1578 				put[1] = uerstat;
1579 				cn_check_magic(sc->sc_tty->t_dev,
1580 					       put[0], sscom_cnm_state);
1581 				if (!cn_trapped) {
1582 					put += 2;
1583 					if (put >= end)
1584 						put = sc->sc_rbuf;
1585 					cc--;
1586 				}
1587 
1588 				ufstat = bus_space_read_2(iot, ioh, SSCOM_UFSTAT);
1589 				if ( (ufstat & (UFSTAT_RXFULL|UFSTAT_RXCOUNT)) == 0 )
1590 					break;
1591 			}
1592 
1593 			/*
1594 			 * Current string of incoming characters ended because
1595 			 * no more data was available or we ran out of space.
1596 			 * Schedule a receive event if any data was received.
1597 			 * If we're out of space, turn off receive interrupts.
1598 			 */
1599 			sc->sc_rbput = put;
1600 			sc->sc_rbavail = cc;
1601 			if (!ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED))
1602 				sc->sc_rx_ready = 1;
1603 
1604 			/*
1605 			 * See if we are in danger of overflowing a buffer. If
1606 			 * so, use hardware flow control to ease the pressure.
1607 			 */
1608 			if (!ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED) &&
1609 			    cc < sc->sc_r_hiwat) {
1610 				SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
1611 				sscom_hwiflow(sc);
1612 			}
1613 
1614 			/*
1615 			 * If we're out of space, disable receive interrupts
1616 			 * until the queue has drained a bit.
1617 			 */
1618 			if (!cc) {
1619 				SET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
1620 				sscom_disable_rxint(sc);
1621 				sc->sc_ucon &= ~UCON_ERRINT;
1622 				bus_space_write_2(iot, ioh, SSCOM_UCON, sc->sc_ucon);
1623 			}
1624 		}
1625 
1626 
1627 		msts = sc->read_modem_status(sc);
1628 		delta = msts ^ sc->sc_msts;
1629 		sc->sc_msts = msts;
1630 
1631 #ifdef notyet
1632 		/*
1633 		 * Pulse-per-second (PSS) signals on edge of DCD?
1634 		 * Process these even if line discipline is ignoring DCD.
1635 		 */
1636 		if (delta & sc->sc_ppsmask) {
1637 			struct timeval tv;
1638 		    	if ((msr & sc->sc_ppsmask) == sc->sc_ppsassert) {
1639 				/* XXX nanotime() */
1640 				microtime(&tv);
1641 				TIMEVAL_TO_TIMESPEC(&tv,
1642 				    &sc->ppsinfo.assert_timestamp);
1643 				if (sc->ppsparam.mode & PPS_OFFSETASSERT) {
1644 					timespecadd(&sc->ppsinfo.assert_timestamp,
1645 					    &sc->ppsparam.assert_offset,
1646 						    &sc->ppsinfo.assert_timestamp);
1647 				}
1648 
1649 #ifdef PPS_SYNC
1650 				if (sc->ppsparam.mode & PPS_HARDPPSONASSERT)
1651 					hardpps(&tv, tv.tv_usec);
1652 #endif
1653 				sc->ppsinfo.assert_sequence++;
1654 				sc->ppsinfo.current_mode = sc->ppsparam.mode;
1655 
1656 			} else if ((msr & sc->sc_ppsmask) == sc->sc_ppsclear) {
1657 				/* XXX nanotime() */
1658 				microtime(&tv);
1659 				TIMEVAL_TO_TIMESPEC(&tv,
1660 				    &sc->ppsinfo.clear_timestamp);
1661 				if (sc->ppsparam.mode & PPS_OFFSETCLEAR) {
1662 					timespecadd(&sc->ppsinfo.clear_timestamp,
1663 					    &sc->ppsparam.clear_offset,
1664 					    &sc->ppsinfo.clear_timestamp);
1665 				}
1666 
1667 #ifdef PPS_SYNC
1668 				if (sc->ppsparam.mode & PPS_HARDPPSONCLEAR)
1669 					hardpps(&tv, tv.tv_usec);
1670 #endif
1671 				sc->ppsinfo.clear_sequence++;
1672 				sc->ppsinfo.current_mode = sc->ppsparam.mode;
1673 			}
1674 		}
1675 #endif
1676 
1677 		/*
1678 		 * Process normal status changes
1679 		 */
1680 		if (ISSET(delta, sc->sc_msr_mask)) {
1681 			SET(sc->sc_msr_delta, delta);
1682 
1683 			/*
1684 			 * Stop output immediately if we lose the output
1685 			 * flow control signal or carrier detect.
1686 			 */
1687 			if (ISSET(~msts, sc->sc_msr_mask)) {
1688 				sc->sc_tbc = 0;
1689 				sc->sc_heldtbc = 0;
1690 #ifdef SSCOM_DEBUG
1691 				if (sscom_debug)
1692 					sscomstatus(sc, "sscomintr  ");
1693 #endif
1694 			}
1695 
1696 			sc->sc_st_check = 1;
1697 		}
1698 
1699 		/*
1700 		 * Done handling any receive interrupts.
1701 		 */
1702 
1703 		/*
1704 		 * If we've delayed a parameter change, do it
1705 		 * now, and restart * output.
1706 		 */
1707 		if ((ufstat & UFSTAT_TXCOUNT) == 0) {
1708 			/* XXX: we should check transmitter empty also */
1709 
1710 			if (sc->sc_heldchange) {
1711 				sscom_loadchannelregs(sc);
1712 				sc->sc_heldchange = 0;
1713 				sc->sc_tbc = sc->sc_heldtbc;
1714 				sc->sc_heldtbc = 0;
1715 			}
1716 		}
1717 
1718 
1719 	} while (0);
1720 
1721 	SSCOM_UNLOCK(sc);
1722 
1723 	/* Wake up the poller. */
1724 	softint_schedule(sc->sc_si);
1725 
1726 #if NRND > 0 && defined(RND_COM)
1727 	rnd_add_uint32(&sc->rnd_source, iir | rsr);
1728 #endif
1729 
1730 	return 1;
1731 }
1732 
1733 int
1734 sscomtxintr(void *arg)
1735 {
1736 	struct sscom_softc *sc = arg;
1737 	bus_space_tag_t iot = sc->sc_iot;
1738 	bus_space_handle_t ioh = sc->sc_ioh;
1739 	uint16_t ufstat;
1740 
1741 	if (SSCOM_ISALIVE(sc) == 0)
1742 		return 0;
1743 
1744 	SSCOM_LOCK(sc);
1745 
1746 	ufstat = bus_space_read_2(iot, ioh, SSCOM_UFSTAT);
1747 
1748 	/*
1749 	 * If we've delayed a parameter change, do it
1750 	 * now, and restart * output.
1751 	 */
1752 	if (sc->sc_heldchange && (ufstat & UFSTAT_TXCOUNT) == 0) {
1753 		/* XXX: we should check transmitter empty also */
1754 		sscom_loadchannelregs(sc);
1755 		sc->sc_heldchange = 0;
1756 		sc->sc_tbc = sc->sc_heldtbc;
1757 		sc->sc_heldtbc = 0;
1758 	}
1759 
1760 	/*
1761 	 * See if data can be transmitted as well. Schedule tx
1762 	 * done event if no data left and tty was marked busy.
1763 	 */
1764 	if (!ISSET(ufstat,UFSTAT_TXFULL)) {
1765 		/*
1766 		 * Output the next chunk of the contiguous
1767 		 * buffer, if any.
1768 		 */
1769 		if (sc->sc_tbc > 0) {
1770 			__sscom_output_chunk(sc, ufstat);
1771 		}
1772 		else {
1773 			/*
1774 			 * Disable transmit sscompletion
1775 			 * interrupts if necessary.
1776 			 */
1777 			if (sc->sc_hwflags & SSCOM_HW_TXINT)
1778 				sscom_disable_txint(sc);
1779 			if (sc->sc_tx_busy) {
1780 				sc->sc_tx_busy = 0;
1781 				sc->sc_tx_done = 1;
1782 			}
1783 		}
1784 	}
1785 
1786 	SSCOM_UNLOCK(sc);
1787 
1788 	/* Wake up the poller. */
1789 	softint_schedule(sc->sc_si);
1790 
1791 #if NRND > 0 && defined(RND_COM)
1792 	rnd_add_uint32(&sc->rnd_source, iir | rsr);
1793 #endif
1794 
1795 	return 1;
1796 }
1797 
1798 
1799 #if defined(KGDB) || defined(SSCOM0CONSOLE) || defined(SSCOM1CONSOLE)
1800 /*
1801  * Initialize UART for use as console or KGDB line.
1802  */
1803 static int
1804 sscom_init(bus_space_tag_t iot, const struct sscom_uart_info *config,
1805     int rate, int frequency, tcflag_t cflag, bus_space_handle_t *iohp)
1806 {
1807 	bus_space_handle_t ioh;
1808 	bus_addr_t iobase = config->iobase;
1809 
1810 	if (bus_space_map(iot, iobase, SSCOM_SIZE, 0, &ioh))
1811 		return ENOMEM; /* ??? */
1812 
1813 	bus_space_write_2(iot, ioh, SSCOM_UCON, 0);
1814 	bus_space_write_1(iot, ioh, SSCOM_UFCON,
1815 	    UFCON_TXTRIGGER_8 | UFCON_RXTRIGGER_8 |
1816 	    UFCON_TXFIFO_RESET | UFCON_RXFIFO_RESET |
1817 	    UFCON_FIFO_ENABLE );
1818 	/* tx/rx fifo reset are auto-cleared */
1819 
1820 	rate = sscomspeed(rate, frequency);
1821 	bus_space_write_2(iot, ioh, SSCOM_UBRDIV, rate);
1822 	bus_space_write_2(iot, ioh, SSCOM_ULCON, cflag2lcr(cflag));
1823 
1824 	/* enable UART */
1825 	bus_space_write_2(iot, ioh, SSCOM_UCON,
1826 	    UCON_TXMODE_INT|UCON_RXMODE_INT);
1827 	bus_space_write_2(iot, ioh, SSCOM_UMCON, UMCON_RTS);
1828 
1829 	*iohp = ioh;
1830 	return 0;
1831 }
1832 
1833 #endif
1834 
1835 #if defined(SSCOM0CONSOLE) || defined(SSCOM1CONSOLE)
1836 /*
1837  * Following are all routines needed for SSCOM to act as console
1838  */
1839 struct consdev sscomcons = {
1840 	NULL, NULL, sscomcngetc, sscomcnputc, sscomcnpollc, NULL,
1841 	NULL, NULL, NODEV, CN_NORMAL
1842 };
1843 
1844 
1845 int
1846 sscom_cnattach(bus_space_tag_t iot, const struct sscom_uart_info *config,
1847     int rate, int frequency, tcflag_t cflag)
1848 {
1849 	int res;
1850 
1851 	res = sscom_init(iot, config, rate, frequency, cflag, &sscomconsioh);
1852 	if (res)
1853 		return res;
1854 
1855 	cn_tab = &sscomcons;
1856 	cn_init_magic(&sscom_cnm_state);
1857 	cn_set_magic("\047\001"); /* default magic is BREAK */
1858 
1859 	sscomconstag = iot;
1860 	sscomconsunit = config->unit;
1861 	sscomconsrate = rate;
1862 	sscomconscflag = cflag;
1863 
1864 	return 0;
1865 }
1866 
1867 void
1868 sscom_cndetach(void)
1869 {
1870 	bus_space_unmap(sscomconstag, sscomconsioh, SSCOM_SIZE);
1871 	sscomconstag = NULL;
1872 
1873 	cn_tab = NULL;
1874 }
1875 
1876 /*
1877  * The read-ahead code is so that you can detect pending in-band
1878  * cn_magic in polled mode while doing output rather than having to
1879  * wait until the kernel decides it needs input.
1880  */
1881 
1882 #define MAX_READAHEAD	20
1883 static int sscom_readahead[MAX_READAHEAD];
1884 static int sscom_readaheadcount = 0;
1885 
1886 int
1887 sscomcngetc(dev_t dev)
1888 {
1889 	int s = splserial();
1890 	u_char stat, c;
1891 
1892 	/* got a character from reading things earlier */
1893 	if (sscom_readaheadcount > 0) {
1894 		int i;
1895 
1896 		c = sscom_readahead[0];
1897 		for (i = 1; i < sscom_readaheadcount; i++) {
1898 			sscom_readahead[i-1] = sscom_readahead[i];
1899 		}
1900 		sscom_readaheadcount--;
1901 		splx(s);
1902 		return c;
1903 	}
1904 
1905 	/* block until a character becomes available */
1906 	while (!sscom_rxrdy(sscomconstag, sscomconsioh))
1907 		;
1908 
1909 	c = sscom_getc(sscomconstag, sscomconsioh);
1910 	stat = sscom_geterr(sscomconstag, sscomconsioh);
1911 	{
1912 		int cn_trapped = 0; /* unused */
1913 #ifdef DDB
1914 		extern int db_active;
1915 		if (!db_active)
1916 #endif
1917 			cn_check_magic(dev, c, sscom_cnm_state);
1918 	}
1919 	splx(s);
1920 	return c;
1921 }
1922 
1923 /*
1924  * Console kernel output character routine.
1925  */
1926 void
1927 sscomcnputc(dev_t dev, int c)
1928 {
1929 	int s = splserial();
1930 	int timo;
1931 
1932 	int cin, stat;
1933 	if (sscom_readaheadcount < MAX_READAHEAD &&
1934 	    sscom_rxrdy(sscomconstag, sscomconsioh)) {
1935 
1936 		int cn_trapped = 0;
1937 		cin = sscom_getc(sscomconstag, sscomconsioh);
1938 		stat = sscom_geterr(sscomconstag, sscomconsioh);
1939 		cn_check_magic(dev, cin, sscom_cnm_state);
1940 		sscom_readahead[sscom_readaheadcount++] = cin;
1941 	}
1942 
1943 	/* wait for any pending transmission to finish */
1944 	timo = 150000;
1945 	while (ISSET(bus_space_read_2(sscomconstag, sscomconsioh, SSCOM_UFSTAT),
1946 		   UFSTAT_TXFULL) && --timo)
1947 		continue;
1948 
1949 	bus_space_write_1(sscomconstag, sscomconsioh, SSCOM_UTXH, c);
1950 	SSCOM_BARRIER(sscomconstag, sscomconsioh, BR | BW);
1951 
1952 #if 0
1953 	/* wait for this transmission to complete */
1954 	timo = 1500000;
1955 	while (!ISSET(bus_space_read_1(sscomconstag, sscomconsioh, SSCOM_UTRSTAT),
1956 		   UTRSTAT_TXEMPTY) && --timo)
1957 		continue;
1958 #endif
1959 	splx(s);
1960 }
1961 
1962 void
1963 sscomcnpollc(dev_t dev, int on)
1964 {
1965 
1966 }
1967 
1968 #endif /* SSCOM0CONSOLE||SSCOM1CONSOLE */
1969 
1970 #ifdef KGDB
1971 int
1972 sscom_kgdb_attach(bus_space_tag_t iot, const struct sscom_uart_info *config,
1973     int rate, int frequency, tcflag_t cflag)
1974 {
1975 	int res;
1976 
1977 	if (iot == sscomconstag && config->unit == sscomconsunit) {
1978 		printf( "console==kgdb_port (%d): kgdb disabled\n", sscomconsunit);
1979 		return EBUSY; /* cannot share with console */
1980 	}
1981 
1982 	res = sscom_init(iot, config, rate, frequency, cflag, &sscom_kgdb_ioh);
1983 	if (res)
1984 		return res;
1985 
1986 	kgdb_attach(sscom_kgdb_getc, sscom_kgdb_putc, NULL);
1987 	kgdb_dev = 123; /* unneeded, only to satisfy some tests */
1988 
1989 	sscom_kgdb_iot = iot;
1990 	sscom_kgdb_unit = config->unit;
1991 
1992 	return 0;
1993 }
1994 
1995 /* ARGSUSED */
1996 int
1997 sscom_kgdb_getc(void *arg)
1998 {
1999 	int c, stat;
2000 
2001 	/* block until a character becomes available */
2002 	while (!sscom_rxrdy(sscom_kgdb_iot, sscom_kgdb_ioh))
2003 		;
2004 
2005 	c = sscom_getc(sscom_kgdb_iot, sscom_kgdb_ioh);
2006 	stat = sscom_geterr(sscom_kgdb_iot, sscom_kgdb_ioh);
2007 
2008 	return c;
2009 }
2010 
2011 /* ARGSUSED */
2012 void
2013 sscom_kgdb_putc(void *arg, int c)
2014 {
2015 	int timo;
2016 
2017 	/* wait for any pending transmission to finish */
2018 	timo = 150000;
2019 	while (ISSET(bus_space_read_2(sscom_kgdb_iot, sscom_kgdb_ioh,
2020 	    SSCOM_UFSTAT), UFSTAT_TXFULL) && --timo)
2021 		continue;
2022 
2023 	bus_space_write_1(sscom_kgdb_iot, sscom_kgdb_ioh, SSCOM_UTXH, c);
2024 	SSCOM_BARRIER(sscom_kgdb_iot, sscom_kgdb_ioh, BR | BW);
2025 
2026 #if 0
2027 	/* wait for this transmission to complete */
2028 	timo = 1500000;
2029 	while (!ISSET(bus_space_read_1(sscom_kgdb_iot, sscom_kgdb_ioh,
2030 	    SSCOM_UTRSTAT), UTRSTAT_TXEMPTY) && --timo)
2031 		continue;
2032 #endif
2033 }
2034 #endif /* KGDB */
2035 
2036 /* helper function to identify the sscom ports used by
2037  console or KGDB (and not yet autoconf attached) */
2038 int
2039 sscom_is_console(bus_space_tag_t iot, int unit,
2040     bus_space_handle_t *ioh)
2041 {
2042 	bus_space_handle_t help;
2043 
2044 	if (!sscomconsattached &&
2045 	    iot == sscomconstag && unit == sscomconsunit)
2046 		help = sscomconsioh;
2047 #ifdef KGDB
2048 	else if (!sscom_kgdb_attached &&
2049 	    iot == sscom_kgdb_iot && unit == sscom_kgdb_unit)
2050 		help = sscom_kgdb_ioh;
2051 #endif
2052 	else
2053 		return 0;
2054 
2055 	if (ioh)
2056 		*ioh = help;
2057 	return 1;
2058 }
2059