xref: /netbsd-src/sys/arch/mips/sibyte/dev/sbscn.c (revision d710132b4b8ce7f7cccaaf660cb16aa16b4077a0)
1 /* $NetBSD: sbscn.c,v 1.8 2003/03/28 07:10:35 he Exp $ */
2 
3 /*
4  * Copyright 2000, 2001
5  * Broadcom Corporation. All rights reserved.
6  *
7  * This software is furnished under license and may be used and copied only
8  * in accordance with the following terms and conditions.  Subject to these
9  * conditions, you may download, copy, install, use, modify and distribute
10  * modified or unmodified copies of this software in source and/or binary
11  * form. No title or ownership is transferred hereby.
12  *
13  * 1) Any source code used, modified or distributed must reproduce and
14  *    retain this copyright notice and list of conditions as they appear in
15  *    the source file.
16  *
17  * 2) No right is granted to use any trade name, trademark, or logo of
18  *    Broadcom Corporation.  The "Broadcom Corporation" name may not be
19  *    used to endorse or promote products derived from this software
20  *    without the prior written permission of Broadcom Corporation.
21  *
22  * 3) THIS SOFTWARE IS PROVIDED "AS-IS" AND ANY EXPRESS OR IMPLIED
23  *    WARRANTIES, INCLUDING BUT NOT LIMITED TO, ANY IMPLIED WARRANTIES OF
24  *    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR
25  *    NON-INFRINGEMENT ARE DISCLAIMED. IN NO EVENT SHALL BROADCOM BE LIABLE
26  *    FOR ANY DAMAGES WHATSOEVER, AND IN PARTICULAR, BROADCOM SHALL NOT BE
27  *    LIABLE FOR DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
28  *    CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
29  *    SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
30  *    BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
31  *    WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
32  *    OR OTHERWISE), EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33  */
34 
35 #define	SBSCN_DEBUG
36 
37 /* from: $NetBSD: com.c,v 1.172 2000/05/03 19:19:04 thorpej Exp */
38 
39 /*-
40  * Copyright (c) 1998, 1999 The NetBSD Foundation, Inc.
41  * All rights reserved.
42  *
43  * This code is derived from software contributed to The NetBSD Foundation
44  * by Charles M. Hannum.
45  *
46  * Redistribution and use in source and binary forms, with or without
47  * modification, are permitted provided that the following conditions
48  * are met:
49  * 1. Redistributions of source code must retain the above copyright
50  *    notice, this list of conditions and the following disclaimer.
51  * 2. Redistributions in binary form must reproduce the above copyright
52  *    notice, this list of conditions and the following disclaimer in the
53  *    documentation and/or other materials provided with the distribution.
54  * 3. All advertising materials mentioning features or use of this software
55  *    must display the following acknowledgement:
56  *        This product includes software developed by the NetBSD
57  *        Foundation, Inc. and its contributors.
58  * 4. Neither the name of The NetBSD Foundation nor the names of its
59  *    contributors may be used to endorse or promote products derived
60  *    from this software without specific prior written permission.
61  *
62  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
63  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
64  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
65  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
66  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
67  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
68  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
69  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
70  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
71  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
72  * POSSIBILITY OF SUCH DAMAGE.
73  */
74 
75 /*
76  * Copyright (c) 1991 The Regents of the University of California.
77  * All rights reserved.
78  *
79  * Redistribution and use in source and binary forms, with or without
80  * modification, are permitted provided that the following conditions
81  * are met:
82  * 1. Redistributions of source code must retain the above copyright
83  *    notice, this list of conditions and the following disclaimer.
84  * 2. Redistributions in binary form must reproduce the above copyright
85  *    notice, this list of conditions and the following disclaimer in the
86  *    documentation and/or other materials provided with the distribution.
87  * 3. All advertising materials mentioning features or use of this software
88  *    must display the following acknowledgement:
89  *	This product includes software developed by the University of
90  *	California, Berkeley and its contributors.
91  * 4. Neither the name of the University nor the names of its contributors
92  *    may be used to endorse or promote products derived from this software
93  *    without specific prior written permission.
94  *
95  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
96  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
97  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
98  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
99  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
100  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
101  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
102  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
103  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
104  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
105  * SUCH DAMAGE.
106  *
107  *	@(#)com.c	7.5 (Berkeley) 5/16/91
108  */
109 
110 /*
111  * `sbscn' driver, supports SiByte SB-1250 SOC DUART.
112  *
113  * This DUART is quite similar in programming model to the scn2681/68681
114  * DUARTs supported by the NetBSD/amiga `mfc' and NetBSD/pc532 `scn'
115  * driver, but substantial rework would have been necessary to make
116  * those drivers sane w.r.t. bus_space (which would then have been
117  * required on NetBSD/sbmips very early on), and to accommodate the
118  * different register mappings.
119  *
120  * So, another driver.  Eventually there should be One True Driver,
121  * but we're not here to save the world.
122  */
123 
124 #include "opt_ddb.h"
125 
126 #include "rnd.h"
127 #if NRND > 0 && defined(RND_SBSCN)
128 #include <sys/rnd.h>
129 #endif
130 
131 #include <sys/param.h>
132 #include <sys/systm.h>
133 #include <sys/ioctl.h>
134 #include <sys/select.h>
135 #include <sys/tty.h>
136 #include <sys/proc.h>
137 #include <sys/user.h>
138 #include <sys/conf.h>
139 #include <sys/file.h>
140 #include <sys/uio.h>
141 #include <sys/kernel.h>
142 #include <sys/syslog.h>
143 #include <sys/types.h>
144 #include <sys/device.h>
145 #include <sys/malloc.h>
146 #include <sys/vnode.h>
147 
148 #include <mips/sibyte/dev/sbobiovar.h>
149 #if 0
150 #include <mips/sibyte/dev/sbscnreg.h>
151 #endif
152 #include <mips/sibyte/dev/sbscnvar.h>
153 #include <dev/cons.h>
154 #include <machine/locore.h>
155 
156 void	sbscn_attach_channel(struct sbscn_softc *sc, int chan, int intr);
157 #if defined(DDB) || defined(KGDB)
158 static void sbscn_enable_debugport(struct sbscn_channel *ch);
159 #endif
160 void	sbscn_config(struct sbscn_channel *ch);
161 void	sbscn_shutdown(struct sbscn_channel *ch);
162 int	sbscn_speed(long, long *);
163 static int cflag2modes(tcflag_t, u_char *, u_char *);
164 int	sbscn_param(struct tty *, struct termios *);
165 void	sbscn_start(struct tty *);
166 int	sbscn_hwiflow(struct tty *, int);
167 
168 void	sbscn_loadchannelregs(struct sbscn_channel *);
169 void	sbscn_dohwiflow(struct sbscn_channel *);
170 void	sbscn_break(struct sbscn_channel *, int);
171 void	sbscn_modem(struct sbscn_channel *, int);
172 void	tiocm_to_sbscn(struct sbscn_channel *, int, int);
173 int	sbscn_to_tiocm(struct sbscn_channel *);
174 void	sbscn_iflush(struct sbscn_channel *);
175 
176 int	sbscn_init(u_long addr, int chan, int rate, tcflag_t cflag);
177 int	sbscn_common_getc(u_long addr, int chan);
178 void	sbscn_common_putc(u_long addr, int chan, int c);
179 void	sbscn_intr(void *arg, uint32_t status, uint32_t pc);
180 
181 int	sbscn_cngetc(dev_t dev);
182 void	sbscn_cnputc(dev_t dev, int c);
183 void	sbscn_cnpollc(dev_t dev, int on);
184 
185 extern struct cfdriver sbscn_cd;
186 
187 dev_type_open(sbscnopen);
188 dev_type_close(sbscnclose);
189 dev_type_read(sbscnread);
190 dev_type_write(sbscnwrite);
191 dev_type_ioctl(sbscnioctl);
192 dev_type_stop(sbscnstop);
193 dev_type_tty(sbscntty);
194 dev_type_poll(sbscnpoll);
195 
196 const struct cdevsw sbscn_cdevsw = {
197 	sbscnopen, sbscnclose, sbscnread, sbscnwrite, sbscnioctl,
198 	sbscnstop, sbscntty, sbscnpoll, nommap, ttykqfilter, D_TTY
199 };
200 
201 #define	integrate	static inline
202 void 	sbscn_soft(void *);
203 integrate void sbscn_rxsoft(struct sbscn_channel *, struct tty *);
204 integrate void sbscn_txsoft(struct sbscn_channel *, struct tty *);
205 integrate void sbscn_stsoft(struct sbscn_channel *, struct tty *);
206 integrate void sbscn_schedrx(struct sbscn_channel *);
207 void	sbscn_diag(void *);
208 
209 /*
210  * Make this an option variable one can patch.
211  * But be warned:  this must be a power of 2!
212  */
213 u_int sbscn_rbuf_size = SBSCN_RING_SIZE;
214 
215 /* Stop input when 3/4 of the ring is full; restart when only 1/4 is full. */
216 u_int sbscn_rbuf_hiwat = (SBSCN_RING_SIZE * 1) / 4;
217 u_int sbscn_rbuf_lowat = (SBSCN_RING_SIZE * 3) / 4;
218 
219 static int	sbscn_cons_present;
220 static int	sbscn_cons_attached;
221 static u_long	sbscn_cons_addr;
222 static int	sbscn_cons_chan;
223 static int	sbscn_cons_rate;
224 static tcflag_t	sbscn_cons_cflag;
225 
226 #ifdef KGDB
227 #include <sys/kgdb.h>
228 
229 static int	sbscn_kgdb_present;
230 static int	sbscn_kgdb_attached;
231 static u_long	sbscn_kgdb_addr;
232 static int	sbscn_kgdb_chan;
233 
234 int	sbscn_kgdb_getc(void *);
235 void	sbscn_kgdb_putc(void *, int);
236 #endif /* KGDB */
237 
238 static int	sbscn_match(struct device *, struct cfdata *, void *);
239 static void	sbscn_attach(struct device *, struct device *, void *);
240 
241 CFATTACH_DECL(sbscn, sizeof(struct sbscn_softc),
242     sbscn_match, sbscn_attach, NULL, NULL);
243 
244 #define	READ_REG(rp)		(mips3_ld((uint64_t *)(rp)))
245 #define	WRITE_REG(rp, val)	(mips3_sd((uint64_t *)(rp), (val)))
246 
247 /*
248  * input and output signals are actually the _inverse_ of the bits in the
249  * input and output port registers!
250  */
251 #define	GET_INPUT_SIGNALS(ch) \
252     ((~READ_REG(MIPS_PHYS_TO_KSEG1((ch)->ch_sc->sc_addr + 0x280))) & (ch)->ch_i_mask)
253 #define	SET_OUTPUT_SIGNALS(ch, val) 					\
254     do {								\
255 	int sigs_to_set, sigs_to_clr;					\
256 									\
257 	sigs_to_set = (ch)->ch_o_mask & val;				\
258 	sigs_to_clr = (ch)->ch_o_mask & ~val;				\
259 									\
260 	/* set signals by clearing op bits, and vice versa */		\
261 	WRITE_REG(MIPS_PHYS_TO_KSEG1((ch)->ch_sc->sc_addr + 0x2c0),	\
262 	    sigs_to_set);						\
263 	WRITE_REG(MIPS_PHYS_TO_KSEG1((ch)->ch_sc->sc_addr + 0x2b0),	\
264 	    sigs_to_clr);						\
265     } while (0)
266 
267 static int
268 sbscn_match(struct device *parent, struct cfdata *match, void *aux)
269 {
270 	struct sbobio_attach_args *sap = aux;
271 
272 	if (sap->sa_locs.sa_type != SBOBIO_DEVTYPE_DUART)
273 		return (0);
274 
275 	return 1;
276 }
277 
278 static void
279 sbscn_attach(struct device *parent, struct device *self, void *aux)
280 {
281 	struct sbscn_softc *sc = (struct sbscn_softc *)self;
282 	struct sbobio_attach_args *sap = aux;
283 	int i;
284 
285 	sc->sc_addr = sap->sa_base + sap->sa_locs.sa_offset;
286 
287 	printf("\n");
288 	for (i = 0; i < 2; i++)
289 		sbscn_attach_channel(sc, i, sap->sa_locs.sa_intr[i]);
290 
291 	/* init duart_opcr */
292 	WRITE_REG(MIPS_PHYS_TO_KSEG1(sc->sc_addr + 0x270), 0);
293 	/* init duart_aux_ctrl */
294 	WRITE_REG(MIPS_PHYS_TO_KSEG1(sc->sc_addr + 0x210), 0x0f); /* XXX */
295 }
296 
297 void
298 sbscn_attach_channel(struct sbscn_softc *sc, int chan, int intr)
299 {
300 	struct sbscn_channel *ch = &sc->sc_channels[chan];
301 	u_long chan_addr;
302 	struct tty *tp;
303 
304 	ch->ch_sc = sc;
305 	ch->ch_num = chan;
306 
307 	chan_addr = sc->sc_addr + (0x100 * chan);
308 	ch->ch_base = (void *)MIPS_PHYS_TO_KSEG1(chan_addr);
309 	ch->ch_isr_base =
310 	    (void *)MIPS_PHYS_TO_KSEG1(sc->sc_addr + 0x220 + (0x20 * chan));
311 	ch->ch_imr_base =
312 	    (void *)MIPS_PHYS_TO_KSEG1(sc->sc_addr + 0x230 + (0x20 * chan));
313 #ifdef XXXCGDnotyet
314 	ch->ch_inchg_base =
315 	    (void *)MIPS_PHYS_TO_KSEG1(sc->sc_addr + 0x2d0 + (0x10 * chan));
316 #endif
317 
318 	ch->ch_i_dcd = ch->ch_i_dcd_pin = 0 /* XXXCGD */;
319 	ch->ch_i_cts = ch->ch_i_cts_pin = 0 /* XXXCGD */;
320 	ch->ch_i_dsr = ch->ch_i_dsr_pin = 0 /* XXXCGD */;
321 	ch->ch_i_ri = ch->ch_i_ri_pin = 0 /* XXXCGD */;
322 	ch->ch_i_mask =
323 	    ch->ch_i_dcd | ch->ch_i_cts | ch->ch_i_dsr | ch->ch_i_ri;
324 	ch->ch_o_dtr = ch->ch_o_dtr_pin = 0 /* XXXCGD */;
325 	ch->ch_o_rts = ch->ch_o_rts_pin = 0 /* XXXCGD */;
326 	ch->ch_o_mask = ch->ch_o_dtr | ch->ch_o_rts;
327 
328 	ch->ch_intrhand = cpu_intr_establish(intr, IPL_SERIAL, sbscn_intr, ch);
329 	callout_init(&ch->ch_diag_callout);
330 
331 	/* Disable interrupts before configuring the device. */
332 	ch->ch_imr = 0;
333 	WRITE_REG(ch->ch_imr_base, ch->ch_imr);
334 
335 	if (sbscn_cons_present &&
336 	    sbscn_cons_addr == chan_addr && sbscn_cons_chan == chan) {
337 		sbscn_cons_attached = 1;
338 
339 		/* Make sure the console is always "hardwired". */
340 		delay(1000);			/* wait for output to finish */
341 		SET(ch->ch_hwflags, SBSCN_HW_CONSOLE);
342 		SET(ch->ch_swflags, TIOCFLAG_SOFTCAR);
343 	}
344 
345 	tp = ttymalloc();
346 	tp->t_oproc = sbscn_start;
347 	tp->t_param = sbscn_param;
348 	tp->t_hwiflow = sbscn_hwiflow;
349 
350 	ch->ch_tty = tp;
351 	ch->ch_rbuf = malloc(sbscn_rbuf_size << 1, M_DEVBUF, M_NOWAIT);
352 	if (ch->ch_rbuf == NULL) {
353 		printf("%s: channel %d: unable to allocate ring buffer\n",
354 		    sc->sc_dev.dv_xname, chan);
355 		return;
356 	}
357 	ch->ch_ebuf = ch->ch_rbuf + (sbscn_rbuf_size << 1);
358 
359 	tty_attach(tp);
360 
361 	if (ISSET(ch->ch_hwflags, SBSCN_HW_CONSOLE)) {
362 		int maj;
363 
364 		/* locate the major number */
365 		maj = cdevsw_lookup_major(&sbscn_cdevsw);
366 
367 		cn_tab->cn_dev = makedev(maj, (sc->sc_dev.dv_unit << 1) + chan);
368 
369 		printf("%s: channel %d: console\n", sc->sc_dev.dv_xname, chan);
370 	}
371 
372 #ifdef KGDB
373 	/*
374 	 * Allow kgdb to "take over" this port.  If this is
375 	 * the kgdb device, it has exclusive use.
376 	 */
377 	if (sbscn_kgdb_present &&
378 	    sbscn_kgdb_addr == chan_addr && sbscn_kgdb_chan == chan) {
379 		sbscn_kgdb_attached = 1;
380 
381 		SET(sc->sc_hwflags, SBSCN_HW_KGDB);
382 		printf("%s: channel %d: kgdb\n", sc->sc_dev.dv_xname, chan);
383 	}
384 #endif
385 
386 	ch->ch_si = softintr_establish(IPL_SOFTSERIAL, sbscn_soft, ch);
387 
388 #if NRND > 0 && defined(RND_SBSCN)
389 	rnd_attach_source(&ch->ch_rnd_source, sc->sc_dev.dv_xname,
390 			  RND_TYPE_TTY, 0);
391 #endif
392 
393 	sbscn_config(ch);
394 
395 	SET(ch->ch_hwflags, SBSCN_HW_DEV_OK);
396 }
397 
398 int
399 sbscn_speed(long speed, long *brcp)
400 {
401 #define	divrnd(n, q)	(((n)*2/(q)+1)/2)	/* divide and round off */
402 
403 	int x, err;
404 	int frequency = 100000000;
405 
406 	*brcp = divrnd(frequency / 20, speed) - 1;
407 
408 	if (speed <= 0)
409 		return (-1);
410 	x = divrnd(frequency / 20, speed);
411 	if (x <= 0)
412 		return (-1);
413 	err = divrnd(((quad_t)frequency) * 1000 / 20, speed * x) - 1000;
414 	if (err < 0)
415 		err = -err;
416 	if (err > SBSCN_TOLERANCE)
417 		return (-1);
418 	*brcp = x - 1;
419 	return (0);
420 
421 #undef	divrnd
422 }
423 
424 #ifdef SBSCN_DEBUG
425 void	sbscn_status(struct sbscn_channel *, char *);
426 
427 int	sbscn_debug = 0 /* XXXCGD */;
428 
429 void
430 sbscn_status(struct sbscn_channel *ch, char *str)
431 {
432 	struct sbscn_softc *sc = ch->ch_sc;
433 	struct tty *tp = ch->ch_tty;
434 
435 	printf("%s: chan %d: %s %sclocal  %sdcd %sts_carr_on %sdtr %stx_stopped\n",
436 	    sc->sc_dev.dv_xname, ch->ch_num, str,
437 	    ISSET(tp->t_cflag, CLOCAL) ? "+" : "-",
438 	    ISSET(ch->ch_iports, ch->ch_i_dcd) ? "+" : "-",
439 	    ISSET(tp->t_state, TS_CARR_ON) ? "+" : "-",
440 	    ISSET(ch->ch_oports, ch->ch_o_dtr) ? "+" : "-",
441 	    ch->ch_tx_stopped ? "+" : "-");
442 
443 	printf("%s: chan %d: %s %scrtscts %scts %sts_ttstop  %srts %xrx_flags\n",
444 	    sc->sc_dev.dv_xname, ch->ch_num, str,
445 	    ISSET(tp->t_cflag, CRTSCTS) ? "+" : "-",
446 	    ISSET(ch->ch_iports, ch->ch_i_cts) ? "+" : "-",
447 	    ISSET(tp->t_state, TS_TTSTOP) ? "+" : "-",
448 	    ISSET(ch->ch_oports, ch->ch_o_rts) ? "+" : "-",
449 	    ch->ch_rx_flags);
450 }
451 #endif
452 
453 #if defined(DDB) || defined(KGDB)
454 static void
455 sbscn_enable_debugport(struct sbscn_channel *ch)
456 {
457 	int s;
458 
459 	/* Turn on line break interrupt, set carrier. */
460 	s = splserial();
461 
462 #if 0	/* DO NOT turn on break interrupt at this time. */
463 	ch->ch_imr = 0x04;
464 #else
465 	ch->ch_imr = 0x00;
466 #endif
467 	WRITE_REG(ch->ch_imr_base, ch->ch_imr);
468 	SET(ch->ch_oports, ch->ch_o_dtr | ch->ch_o_rts);
469 	SET_OUTPUT_SIGNALS(ch, ch->ch_oports);
470 
471 	splx(s);
472 }
473 #endif
474 
475 void
476 sbscn_config(struct sbscn_channel *ch)
477 {
478 
479 	/* Disable interrupts before configuring the device. */
480 	ch->ch_imr = 0x00;
481 	WRITE_REG(ch->ch_imr_base, ch->ch_imr);
482 
483 #ifdef DDB
484 	if (ISSET(ch->ch_hwflags, SBSCN_HW_CONSOLE))
485 		sbscn_enable_debugport(ch);
486 #endif
487 
488 #ifdef KGDB
489 	/*
490 	 * Allow kgdb to "take over" this port.  If this is
491 	 * the kgdb device, it has exclusive use.
492 	 */
493 	if (ISSET(ch->ch_hwflags, SBSCN_HW_KGDB))
494 		sbscn_enable_debugport(ch);
495 #endif
496 }
497 
498 void
499 sbscn_shutdown(struct sbscn_channel *ch)
500 {
501 	struct tty *tp = ch->ch_tty;
502 	int s;
503 
504 	s = splserial();
505 
506 	/* If we were asserting flow control, then deassert it. */
507 	SET(ch->ch_rx_flags, RX_IBUF_BLOCKED);
508 	sbscn_dohwiflow(ch);
509 
510 	/* Clear any break condition set with TIOCSBRK. */
511 	sbscn_break(ch, 0);
512 
513 	/*
514 	 * Hang up if necessary.  Wait a bit, so the other side has time to
515 	 * notice even if we immediately open the port again.
516 	 * Avoid tsleeping above splhigh().
517 	 */
518 	if (ISSET(tp->t_cflag, HUPCL)) {
519 		sbscn_modem(ch, 0);
520 		splx(s);
521 		/* XXX tsleep will only timeout */
522 		(void) tsleep(ch, TTIPRI, ttclos, hz);
523 		s = splserial();
524 	}
525 
526 	/* Turn off interrupts. */
527 #ifdef DDB
528 	if (ISSET(ch->ch_hwflags, SBSCN_HW_CONSOLE))
529 #if 0	/* DO NOT turn on break interrupt at this time. */
530 		ch->ch_imr = 0x04; /* interrupt on break */
531 #else
532 		ch->ch_imr = 0x00;
533 #endif
534 	else
535 #endif
536 		ch->ch_imr = 0;
537 	WRITE_REG(ch->ch_imr_base, ch->ch_imr);
538 
539 	splx(s);
540 }
541 
542 int
543 sbscnopen(dev_t dev, int flag, int mode, struct proc *p)
544 {
545 	int unit = SBSCN_UNIT(dev);
546 	int chan = SBSCN_CHAN(dev);
547 	struct sbscn_softc *sc;
548 	struct sbscn_channel *ch;
549 	struct tty *tp;
550 	int s, s2;
551 	int error;
552 
553 	if (unit >= sbscn_cd.cd_ndevs)
554 		return (ENXIO);
555 	sc = sbscn_cd.cd_devs[unit];
556 	if (sc == 0)
557 		return (ENXIO);
558 	ch = &sc->sc_channels[chan];
559 	if (!ISSET(ch->ch_hwflags, SBSCN_HW_DEV_OK) || ch->ch_rbuf == NULL)
560 		return (ENXIO);
561 
562 #ifdef KGDB
563 	/*
564 	 * If this is the kgdb port, no other use is permitted.
565 	 */
566 	if (ISSET(ch->ch_hwflags, SBSCN_HW_KGDB))
567 		return (EBUSY);
568 #endif
569 
570 	tp = ch->ch_tty;
571 
572 	if (ISSET(tp->t_state, TS_ISOPEN) &&
573 	    ISSET(tp->t_state, TS_XCLUDE) &&
574 	    p->p_ucred->cr_uid != 0)
575 		return (EBUSY);
576 
577 	s = spltty();
578 
579 	/*
580 	 * Do the following iff this is a first open.
581 	 */
582 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
583 		struct termios t;
584 
585 		tp->t_dev = dev;
586 
587 		s2 = splserial();
588 
589 		/* Turn on receive, break, and status change interrupts. */
590 #if 0	/* DO NOT turn on break or status change interrupt at this time. */
591 		ch->ch_imr = 0xe;
592 #else
593 		ch->ch_imr = 0x2;
594 #endif
595 		WRITE_REG(ch->ch_imr_base, ch->ch_imr);
596 
597 		/* Fetch the current modem control status, needed later. */
598 		ch->ch_iports = GET_INPUT_SIGNALS(ch);
599 		ch->ch_iports_delta = 0;
600 		splx(s2);
601 
602 		/*
603 		 * Initialize the termios status to the defaults.  Add in the
604 		 * sticky bits from TIOCSFLAGS.
605 		 */
606 		t.c_ispeed = 0;
607 		if (ISSET(ch->ch_hwflags, SBSCN_HW_CONSOLE)) {
608 			t.c_ospeed = sbscn_cons_rate;
609 			t.c_cflag = sbscn_cons_cflag;
610 		} else {
611 			t.c_ospeed = TTYDEF_SPEED;
612 			t.c_cflag = TTYDEF_CFLAG;
613 		}
614 		if (ISSET(ch->ch_swflags, TIOCFLAG_CLOCAL))
615 			SET(t.c_cflag, CLOCAL);
616 		if (ISSET(ch->ch_swflags, TIOCFLAG_CRTSCTS))
617 			SET(t.c_cflag, CRTSCTS);
618 		if (ISSET(ch->ch_swflags, TIOCFLAG_MDMBUF))
619 			SET(t.c_cflag, MDMBUF);
620 		/* Make sure sbscn_param() will do something. */
621 		tp->t_ospeed = 0;
622 		(void) sbscn_param(tp, &t);
623 		tp->t_iflag = TTYDEF_IFLAG;
624 		tp->t_oflag = TTYDEF_OFLAG;
625 		tp->t_lflag = TTYDEF_LFLAG;
626 		ttychars(tp);
627 		ttsetwater(tp);
628 
629 		s2 = splserial();
630 
631 		/*
632 		 * Turn on DTR.  We must always do this, even if carrier is not
633 		 * present, because otherwise we'd have to use TIOCSDTR
634 		 * immediately after setting CLOCAL, which applications do not
635 		 * expect.  We always assert DTR while the device is open
636 		 * unless explicitly requested to deassert it.
637 		 */
638 		sbscn_modem(ch, 1);
639 
640 		/* Clear the input ring, and unblock. */
641 		ch->ch_rbput = ch->ch_rbget = ch->ch_rbuf;
642 		ch->ch_rbavail = sbscn_rbuf_size;
643 		sbscn_iflush(ch);
644 		CLR(ch->ch_rx_flags, RX_ANY_BLOCK);
645 		sbscn_dohwiflow(ch);
646 
647 #ifdef SBSCN_DEBUG
648 		if (sbscn_debug)
649 			sbscn_status(ch, "sbscnopen  ");
650 #endif
651 
652 		splx(s2);
653 	}
654 
655 	splx(s);
656 
657 	error = ttyopen(tp, SBSCN_DIALOUT(dev), ISSET(flag, O_NONBLOCK));
658 	if (error)
659 		goto bad;
660 
661 	error = (*tp->t_linesw->l_open)(dev, tp);
662 	if (error)
663 		goto bad;
664 
665 	return (0);
666 
667 bad:
668 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
669 		/*
670 		 * We failed to open the device, and nobody else had it opened.
671 		 * Clean up the state as appropriate.
672 		 */
673 		sbscn_shutdown(ch);
674 	}
675 
676 	return (error);
677 }
678 
679 int
680 sbscnclose(dev_t dev, int flag, int mode, struct proc *p)
681 {
682 	struct sbscn_softc *sc = sbscn_cd.cd_devs[SBSCN_UNIT(dev)];
683 	struct sbscn_channel *ch = &sc->sc_channels[SBSCN_CHAN(dev)];
684 	struct tty *tp = ch->ch_tty;
685 
686 	/* XXX This is for cons.c. */
687 	if (!ISSET(tp->t_state, TS_ISOPEN))
688 		return (0);
689 
690 	(*tp->t_linesw->l_close)(tp, flag);
691 	ttyclose(tp);
692 
693 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
694 		/*
695 		 * Although we got a last close, the device may still be in
696 		 * use; e.g. if this was the dialout node, and there are still
697 		 * processes waiting for carrier on the non-dialout node.
698 		 */
699 		sbscn_shutdown(ch);
700 	}
701 
702 	return (0);
703 }
704 
705 int
706 sbscnread(dev_t dev, struct uio *uio, int flag)
707 {
708 	struct sbscn_softc *sc = sbscn_cd.cd_devs[SBSCN_UNIT(dev)];
709 	struct sbscn_channel *ch = &sc->sc_channels[SBSCN_CHAN(dev)];
710 	struct tty *tp = ch->ch_tty;
711 
712 	return ((*tp->t_linesw->l_read)(tp, uio, flag));
713 }
714 
715 int
716 sbscnwrite(dev_t dev, struct uio *uio, int flag)
717 {
718 	struct sbscn_softc *sc = sbscn_cd.cd_devs[SBSCN_UNIT(dev)];
719 	struct sbscn_channel *ch = &sc->sc_channels[SBSCN_CHAN(dev)];
720 	struct tty *tp = ch->ch_tty;
721 
722 	return ((*tp->t_linesw->l_write)(tp, uio, flag));
723 }
724 
725 int
726 sbscnpoll(dev_t dev, int events, struct proc *p)
727 {
728 	struct sbscn_softc *sc = sbscn_cd.cd_devs[SBSCN_UNIT(dev)];
729 	struct sbscn_channel *ch = &sc->sc_channels[SBSCN_CHAN(dev)];
730 	struct tty *tp = ch->ch_tty;
731 
732 	return ((*tp->t_linesw->l_poll)(tp, events, p));
733 }
734 
735 struct tty *
736 sbscntty(dev_t dev)
737 {
738 	struct sbscn_softc *sc = sbscn_cd.cd_devs[SBSCN_UNIT(dev)];
739 	struct sbscn_channel *ch = &sc->sc_channels[SBSCN_CHAN(dev)];
740 	struct tty *tp = ch->ch_tty;
741 
742 	return (tp);
743 }
744 
745 int
746 sbscnioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct proc *p)
747 {
748 	struct sbscn_softc *sc = sbscn_cd.cd_devs[SBSCN_UNIT(dev)];
749 	struct sbscn_channel *ch = &sc->sc_channels[SBSCN_CHAN(dev)];
750 	struct tty *tp = ch->ch_tty;
751 	int error;
752 	int s;
753 
754 	error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, p);
755 	if (error != EPASSTHROUGH)
756 		return (error);
757 
758 	error = ttioctl(tp, cmd, data, flag, p);
759 	if (error != EPASSTHROUGH)
760 		return (error);
761 
762 	error = 0;
763 
764 	s = splserial();
765 
766 	switch (cmd) {
767 	case TIOCSBRK:
768 		sbscn_break(ch, 1);
769 		break;
770 
771 	case TIOCCBRK:
772 		sbscn_break(ch, 0);
773 		break;
774 
775 	case TIOCSDTR:
776 		sbscn_modem(ch, 1);
777 		break;
778 
779 	case TIOCCDTR:
780 		sbscn_modem(ch, 0);
781 		break;
782 
783 	case TIOCGFLAGS:
784 		*(int *)data = ch->ch_swflags;
785 		break;
786 
787 	case TIOCSFLAGS:
788 		error = suser(p->p_ucred, &p->p_acflag);
789 		if (error)
790 			break;
791 		ch->ch_swflags = *(int *)data;
792 		break;
793 
794 	case TIOCMSET:
795 	case TIOCMBIS:
796 	case TIOCMBIC:
797 		tiocm_to_sbscn(ch, cmd, *(int *)data);
798 		break;
799 
800 	case TIOCMGET:
801 		*(int *)data = sbscn_to_tiocm(ch);
802 		break;
803 
804 	default:
805 		error = EPASSTHROUGH;
806 		break;
807 	}
808 
809 	splx(s);
810 
811 #ifdef SBSCN_DEBUG
812 	if (sbscn_debug)
813 		sbscn_status(ch, "sbscn_ioctl ");
814 #endif
815 
816 	return (error);
817 }
818 
819 integrate void
820 sbscn_schedrx(struct sbscn_channel *ch)
821 {
822 
823 	ch->ch_rx_ready = 1;
824 
825 	/* Wake up the poller. */
826 	softintr_schedule(ch->ch_si);
827 }
828 
829 void
830 sbscn_break(struct sbscn_channel *ch, int onoff)
831 {
832 
833 /* XXXCGD delay break until not busy */
834 	if (onoff)
835 		WRITE_REG(ch->ch_base + 0x50, 0x60);
836 	else
837 		WRITE_REG(ch->ch_base + 0x50, 0x70);
838 
839 #if 0
840 	if (!ch->ch_heldchange) {
841 		if (ch->ch_tx_busy) {
842 			ch->ch_heldtbc = ch->ch_tbc;
843 			ch->ch_tbc = 0;
844 			ch->ch_heldchange = 1;
845 		} else
846 			sbscn_loadchannelregs(ch);
847 	}
848 #endif
849 }
850 
851 void
852 sbscn_modem(struct sbscn_channel *ch, int onoff)
853 {
854 
855 	if (ch->ch_o_dtr == 0)
856 		return;
857 
858 	if (onoff)
859 		SET(ch->ch_oports, ch->ch_o_dtr);
860 	else
861 		CLR(ch->ch_oports, ch->ch_o_dtr);
862 
863 	if (!ch->ch_heldchange) {
864 		if (ch->ch_tx_busy) {
865 			ch->ch_heldtbc = ch->ch_tbc;
866 			ch->ch_tbc = 0;
867 			ch->ch_heldchange = 1;
868 		} else
869 			sbscn_loadchannelregs(ch);
870 	}
871 }
872 
873 void
874 tiocm_to_sbscn(struct sbscn_channel *ch, int how, int ttybits)
875 {
876 	u_char bits;
877 
878 	bits = 0;
879 	if (ISSET(ttybits, TIOCM_DTR))
880 		SET(bits, ch->ch_o_dtr);
881 	if (ISSET(ttybits, TIOCM_RTS))
882 		SET(bits, ch->ch_o_rts);
883 
884 	switch (how) {
885 	case TIOCMBIC:
886 		CLR(ch->ch_oports, bits);
887 		break;
888 
889 	case TIOCMBIS:
890 		SET(ch->ch_oports, bits);
891 		break;
892 
893 	case TIOCMSET:
894 		ch->ch_oports = bits;
895 		break;
896 	}
897 
898 	if (!ch->ch_heldchange) {
899 		if (ch->ch_tx_busy) {
900 			ch->ch_heldtbc = ch->ch_tbc;
901 			ch->ch_tbc = 0;
902 			ch->ch_heldchange = 1;
903 		} else
904 			sbscn_loadchannelregs(ch);
905 	}
906 }
907 
908 int
909 sbscn_to_tiocm(struct sbscn_channel *ch)
910 {
911 	u_char hwbits;
912 	int ttybits = 0;
913 
914 	hwbits = ch->ch_oports;
915 	if (ISSET(hwbits, ch->ch_o_dtr))
916 		SET(ttybits, TIOCM_DTR);
917 	if (ISSET(hwbits, ch->ch_o_rts))
918 		SET(ttybits, TIOCM_RTS);
919 
920 	hwbits = ch->ch_iports;
921 	if (ISSET(hwbits, ch->ch_i_dcd))
922 		SET(ttybits, TIOCM_CD);
923 	if (ISSET(hwbits, ch->ch_i_cts))
924 		SET(ttybits, TIOCM_CTS);
925 	if (ISSET(hwbits, ch->ch_i_dsr))
926 		SET(ttybits, TIOCM_DSR);
927 	if (ISSET(hwbits, ch->ch_i_ri))
928 		SET(ttybits, TIOCM_RI);
929 
930 	if (ch->ch_imr != 0)
931 		SET(ttybits, TIOCM_LE);
932 
933 	return (ttybits);
934 }
935 
936 static int
937 cflag2modes(cflag, mode1p, mode2p)
938 	tcflag_t cflag;
939 	u_char *mode1p;
940 	u_char *mode2p;
941 {
942 	u_char mode1;
943 	u_char mode2;
944 	int err = 0;
945 
946 	mode1 = mode2 = 0;
947 
948 	switch (ISSET(cflag, CSIZE)) {
949 	case CS7:
950 		mode1 |= 2;			/* XXX */
951 		break;
952 	default:
953 		err = -1;
954 		/* FALLTHRU for sanity */
955 	case CS8:
956 		mode1 |= 3;			/* XXX */
957 		break;
958 	}
959 	if (!ISSET(cflag, PARENB))
960 		mode1 |= 2 << 3;
961 	else {
962 		mode1 |= 0 << 3;
963 		if (ISSET(cflag, PARODD))
964 			mode1 |= 1 << 2;
965 	}
966 
967 	if (ISSET(cflag, CSTOPB))
968 		mode2 |= 1 << 3;		/* two stop bits XXX not std */
969 
970 	if (ISSET(cflag, CRTSCTS)) {
971 		mode1 |= 1 << 7;
972 		mode2 |= 1 << 4;
973 	}
974 
975 	*mode1p = mode1;
976 	*mode2p = mode2;
977 	return (err);
978 }
979 
980 int
981 sbscn_param(struct tty *tp, struct termios *t)
982 {
983 	struct sbscn_softc *sc = sbscn_cd.cd_devs[SBSCN_UNIT(tp->t_dev)];
984 	struct sbscn_channel *ch = &sc->sc_channels[SBSCN_CHAN(tp->t_dev)];
985 	long brc;
986 	u_char mode1, mode2;
987 	int s;
988 
989 /* XXX reset to console parameters if console? */
990 #if 0
991 XXX disable, enable.
992 #endif
993 
994 	/* Check requested parameters. */
995 	if (sbscn_speed(t->c_ospeed, &brc) < 0)
996 		return (EINVAL);
997 	if (t->c_ispeed && t->c_ispeed != t->c_ospeed)
998 		return (EINVAL);
999 
1000 	/*
1001 	 * For the console, always force CLOCAL and !HUPCL, so that the port
1002 	 * is always active.
1003 	 */
1004 	if (ISSET(ch->ch_swflags, TIOCFLAG_SOFTCAR) ||
1005 	    ISSET(ch->ch_hwflags, SBSCN_HW_CONSOLE)) {
1006 		SET(t->c_cflag, CLOCAL);
1007 		CLR(t->c_cflag, HUPCL);
1008 	}
1009 
1010 	/*
1011 	 * If there were no changes, don't do anything.  This avoids dropping
1012 	 * input and improves performance when all we did was frob things like
1013 	 * VMIN and VTIME.
1014 	 */
1015 	if (tp->t_ospeed == t->c_ospeed &&
1016 	    tp->t_cflag == t->c_cflag)
1017 		return (0);
1018 
1019 	if (cflag2modes(t->c_cflag, &mode1, &mode2) < 0)
1020 		return (EINVAL);
1021 
1022 	s = splserial();
1023 
1024 	ch->ch_mode1 = mode1;
1025 	ch->ch_mode2 = mode2;
1026 
1027 	/*
1028 	 * If we're not in a mode that assumes a connection is present, then
1029 	 * ignore carrier changes.
1030 	 */
1031 	if (ISSET(t->c_cflag, CLOCAL | MDMBUF))
1032 		ch->ch_i_dcd = 0;
1033 	else
1034 		ch->ch_i_dcd = ch->ch_i_dcd_pin;
1035 	/*
1036 	 * Set the flow control pins depending on the current flow control
1037 	 * mode.
1038 	 */
1039 	if (ISSET(t->c_cflag, CRTSCTS)) {
1040 		ch->ch_o_dtr = ch->ch_o_dtr_pin;
1041 		ch->ch_o_rts = ch->ch_o_rts_pin;
1042 		ch->ch_i_cts = ch->ch_i_cts_pin;
1043 		/* hw controle enable bits in mod regs set by cflag2modes */
1044 	} else if (ISSET(t->c_cflag, MDMBUF)) {
1045 		/*
1046 		 * For DTR/DCD flow control, make sure we don't toggle DTR for
1047 		 * carrier detection.
1048 		 */
1049 		ch->ch_o_dtr = 0;
1050 		ch->ch_o_rts = ch->ch_o_dtr_pin;
1051 		ch->ch_i_cts = ch->ch_i_dcd_pin;
1052 	} else {
1053 		/*
1054 		 * If no flow control, then always set RTS.  This will make
1055 		 * the other side happy if it mistakenly thinks we're doing
1056 		 * RTS/CTS flow control.
1057 		 */
1058 		ch->ch_o_dtr = ch->ch_o_dtr_pin | ch->ch_o_rts_pin;
1059 		ch->ch_o_rts = 0;
1060 		ch->ch_i_cts = 0;
1061 		if (ISSET(ch->ch_oports, ch->ch_o_dtr_pin))
1062 			SET(ch->ch_oports, ch->ch_o_rts_pin);
1063 		else
1064 			CLR(ch->ch_oports, ch->ch_o_rts_pin);
1065 	}
1066 	/* XXX maybe mask the ports which generate intrs? */
1067 
1068 	ch->ch_brc = brc;
1069 
1070 	/* XXX maybe set fifo-full receive mode if RTSCTS and high speed? */
1071 
1072 	/* And copy to tty. */
1073 	tp->t_ispeed = 0;
1074 	tp->t_ospeed = t->c_ospeed;
1075 	tp->t_cflag = t->c_cflag;
1076 
1077 	if (!ch->ch_heldchange) {
1078 		if (ch->ch_tx_busy) {
1079 			ch->ch_heldtbc = ch->ch_tbc;
1080 			ch->ch_tbc = 0;
1081 			ch->ch_heldchange = 1;
1082 		} else
1083 			sbscn_loadchannelregs(ch);
1084 	}
1085 
1086 	if (!ISSET(t->c_cflag, CHWFLOW)) {
1087 		/* Disable the high water mark. */
1088 		ch->ch_r_hiwat = 0;
1089 		ch->ch_r_lowat = 0;
1090 		if (ISSET(ch->ch_rx_flags, RX_TTY_OVERFLOWED)) {
1091 			CLR(ch->ch_rx_flags, RX_TTY_OVERFLOWED);
1092 			sbscn_schedrx(ch);
1093 		}
1094 		if (ISSET(ch->ch_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED)) {
1095 			CLR(ch->ch_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED);
1096 			sbscn_dohwiflow(ch);
1097 		}
1098 	} else {
1099 		ch->ch_r_hiwat = sbscn_rbuf_hiwat;
1100 		ch->ch_r_lowat = sbscn_rbuf_lowat;
1101 	}
1102 
1103 	splx(s);
1104 
1105 	/*
1106 	 * Update the tty layer's idea of the carrier bit, in case we changed
1107 	 * CLOCAL or MDMBUF.  We don't hang up here; we only do that by
1108 	 * explicit request.
1109 	 */
1110 	(void) (*tp->t_linesw->l_modem)(tp,
1111 	    ISSET(ch->ch_iports, ch->ch_i_dcd));
1112 
1113 #ifdef SBSCN_DEBUG
1114 	if (sbscn_debug)
1115 		sbscn_status(ch, "sbscnparam ");
1116 #endif
1117 
1118 	if (!ISSET(t->c_cflag, CHWFLOW)) {
1119 		if (ch->ch_tx_stopped) {
1120 			ch->ch_tx_stopped = 0;
1121 			sbscn_start(tp);
1122 		}
1123 	}
1124 
1125 	return (0);
1126 }
1127 
1128 void
1129 sbscn_iflush(struct sbscn_channel *ch)
1130 {
1131 #ifdef DIAGNOSTIC
1132 	int reg;
1133 #endif
1134 	int timo;
1135 
1136 #ifdef DIAGNOSTIC
1137 	reg = 0xffff;
1138 #endif
1139 	timo = 50000;
1140 	/* flush any pending I/O */
1141 	while (ISSET(READ_REG(ch->ch_base + 0x20), 0x01)
1142 	    && --timo)
1143 #ifdef DIAGNOSTIC
1144 		reg =
1145 #else
1146 		    (void)
1147 #endif
1148 		    READ_REG(ch->ch_base + 0x60);
1149 #ifdef DIAGNOSTIC
1150 	if (!timo)
1151 		printf("%s: sbscn_iflush timeout %02x\n",
1152 		    ch->ch_sc->sc_dev.dv_xname, reg & 0xff);
1153 #endif
1154 }
1155 
1156 void
1157 sbscn_loadchannelregs(struct sbscn_channel *ch)
1158 {
1159 
1160 	/* XXXXX necessary? */
1161 	sbscn_iflush(ch);
1162 
1163 	WRITE_REG(ch->ch_imr_base, 0);
1164 
1165 // XXX disable?
1166 	WRITE_REG(ch->ch_base + 0x00, ch->ch_mode1);
1167 	WRITE_REG(ch->ch_base + 0x10, ch->ch_mode2);
1168 	WRITE_REG(ch->ch_base + 0x30, ch->ch_brc);
1169 
1170 	ch->ch_oports_active = ch->ch_oports;
1171 	SET_OUTPUT_SIGNALS(ch, ch->ch_oports_active);
1172 
1173 	WRITE_REG(ch->ch_imr_base, ch->ch_imr);
1174 }
1175 
1176 int
1177 sbscn_hwiflow(struct tty *tp, int block)
1178 {
1179 	struct sbscn_softc *sc = sbscn_cd.cd_devs[SBSCN_UNIT(tp->t_dev)];
1180 	struct sbscn_channel *ch = &sc->sc_channels[SBSCN_CHAN(tp->t_dev)];
1181 	int s;
1182 
1183 	if (ch->ch_o_rts == 0)
1184 		return (0);
1185 
1186 	s = splserial();
1187 	if (block) {
1188 		if (!ISSET(ch->ch_rx_flags, RX_TTY_BLOCKED)) {
1189 			SET(ch->ch_rx_flags, RX_TTY_BLOCKED);
1190 			sbscn_dohwiflow(ch);
1191 		}
1192 	} else {
1193 		if (ISSET(ch->ch_rx_flags, RX_TTY_OVERFLOWED)) {
1194 			CLR(ch->ch_rx_flags, RX_TTY_OVERFLOWED);
1195 			sbscn_schedrx(ch);
1196 		}
1197 		if (ISSET(ch->ch_rx_flags, RX_TTY_BLOCKED)) {
1198 			CLR(ch->ch_rx_flags, RX_TTY_BLOCKED);
1199 			sbscn_dohwiflow(ch);
1200 		}
1201 	}
1202 	splx(s);
1203 	return (1);
1204 }
1205 
1206 /*
1207  * (un)block input via hw flowcontrol
1208  */
1209 void
1210 sbscn_dohwiflow(struct sbscn_channel *ch)
1211 {
1212 
1213 	if (ch->ch_o_rts == 0)
1214 		return;
1215 
1216 	if (ISSET(ch->ch_rx_flags, RX_ANY_BLOCK)) {
1217 		CLR(ch->ch_oports, ch->ch_o_rts);
1218 		CLR(ch->ch_oports_active, ch->ch_o_rts);
1219 	} else {
1220 		SET(ch->ch_oports, ch->ch_o_rts);
1221 		SET(ch->ch_oports_active, ch->ch_o_rts);
1222 	}
1223 	SET_OUTPUT_SIGNALS(ch, ch->ch_oports_active);
1224 }
1225 
1226 void
1227 sbscn_start(struct tty *tp)
1228 {
1229 	struct sbscn_softc *sc = sbscn_cd.cd_devs[SBSCN_UNIT(tp->t_dev)];
1230 	struct sbscn_channel *ch = &sc->sc_channels[SBSCN_CHAN(tp->t_dev)];
1231 	int s;
1232 
1233 	s = spltty();
1234 	if (ISSET(tp->t_state, TS_BUSY | TS_TIMEOUT | TS_TTSTOP))
1235 		goto out;
1236 	if (ch->ch_tx_stopped)
1237 		goto out;
1238 
1239 	if (tp->t_outq.c_cc <= tp->t_lowat) {
1240 		if (ISSET(tp->t_state, TS_ASLEEP)) {
1241 			CLR(tp->t_state, TS_ASLEEP);
1242 			wakeup(&tp->t_outq);
1243 		}
1244 		selwakeup(&tp->t_wsel);
1245 		if (tp->t_outq.c_cc == 0)
1246 			goto out;
1247 	}
1248 
1249 	/* Grab the first contiguous region of buffer space. */
1250 	{
1251 		u_char *tba;
1252 		int tbc;
1253 
1254 		tba = tp->t_outq.c_cf;
1255 		tbc = ndqb(&tp->t_outq, 0);
1256 
1257 		(void)splserial();
1258 
1259 		ch->ch_tba = tba;
1260 		ch->ch_tbc = tbc;
1261 	}
1262 
1263 	SET(tp->t_state, TS_BUSY);
1264 	ch->ch_tx_busy = 1;
1265 
1266 	/* Enable transmit completion interrupts if necessary. */
1267 	if (!ISSET(ch->ch_imr, 0x1)) {
1268 		SET(ch->ch_imr, 0x1);
1269 		WRITE_REG(ch->ch_imr_base, ch->ch_imr);
1270 	}
1271 
1272 	/* Output the first chunk of the contiguous buffer. */
1273 	{
1274 		u_char c;
1275 
1276 		while (ch->ch_tbc && READ_REG(ch->ch_base + 0x20) & 0x04) {
1277 			c = *ch->ch_tba++;
1278 			ch->ch_tbc--;
1279 			WRITE_REG(ch->ch_base + 0x70, c);
1280 		}
1281 	}
1282 out:
1283 	splx(s);
1284 	return;
1285 }
1286 
1287 /*
1288  * Stop output on a line.
1289  */
1290 void
1291 sbscnstop(struct tty *tp, int flag)
1292 {
1293 	struct sbscn_softc *sc = sbscn_cd.cd_devs[SBSCN_UNIT(tp->t_dev)];
1294 	struct sbscn_channel *ch = &sc->sc_channels[SBSCN_CHAN(tp->t_dev)];
1295 	int s;
1296 
1297 	s = splserial();
1298 	if (ISSET(tp->t_state, TS_BUSY)) {
1299 		/* Stop transmitting at the next chunk. */
1300 		ch->ch_tbc = 0;
1301 		ch->ch_heldtbc = 0;
1302 		if (!ISSET(tp->t_state, TS_TTSTOP))
1303 			SET(tp->t_state, TS_FLUSH);
1304 	}
1305 	splx(s);
1306 }
1307 
1308 void
1309 sbscn_diag(arg)
1310 	void *arg;
1311 {
1312 	struct sbscn_channel *ch = arg;
1313 	struct sbscn_softc *sc = ch->ch_sc;
1314 	int overflows, floods;
1315 	int s;
1316 
1317 	s = splserial();
1318 	overflows = ch->ch_overflows;
1319 	ch->ch_overflows = 0;
1320 	floods = ch->ch_floods;
1321 	ch->ch_floods = 0;
1322 	ch->ch_errors = 0;
1323 	splx(s);
1324 
1325 	log(LOG_WARNING, "%s: channel %d: %d fifo overflow%s, %d ibuf flood%s\n",
1326 	    sc->sc_dev.dv_xname, ch->ch_num,
1327 	    overflows, overflows == 1 ? "" : "s",
1328 	    floods, floods == 1 ? "" : "s");
1329 }
1330 
1331 integrate void
1332 sbscn_rxsoft(struct sbscn_channel *ch, struct tty *tp)
1333 {
1334 	int (*rint)(int c, struct tty *tp) = tp->t_linesw->l_rint;
1335 	u_char *get, *end;
1336 	u_int cc, scc;
1337 	u_char sr;
1338 	int code;
1339 	int s;
1340 
1341 	end = ch->ch_ebuf;
1342 	get = ch->ch_rbget;
1343 	scc = cc = sbscn_rbuf_size - ch->ch_rbavail;
1344 
1345 	if (cc == sbscn_rbuf_size) {
1346 		ch->ch_floods++;
1347 		if (ch->ch_errors++ == 0)
1348 			callout_reset(&ch->ch_diag_callout, 60 * hz,
1349 			    sbscn_diag, ch);
1350 	}
1351 
1352 	while (cc) {
1353 		code = get[0];
1354 		sr = get[1];
1355 		if (ISSET(sr, 0xf0)) {
1356 			if (ISSET(sr, 0x10)) {
1357 				ch->ch_overflows++;
1358 				if (ch->ch_errors++ == 0)
1359 					callout_reset(&ch->ch_diag_callout,
1360 					    60 * hz, sbscn_diag, ch);
1361 			}
1362 			if (ISSET(sr, 0xc0))
1363 				SET(code, TTY_FE);
1364 			if (ISSET(sr, 0x20))
1365 				SET(code, TTY_PE);
1366 		}
1367 		if ((*rint)(code, tp) == -1) {
1368 			/*
1369 			 * The line discipline's buffer is out of space.
1370 			 */
1371 			if (!ISSET(ch->ch_rx_flags, RX_TTY_BLOCKED)) {
1372 				/*
1373 				 * We're either not using flow control, or the
1374 				 * line discipline didn't tell us to block for
1375 				 * some reason.  Either way, we have no way to
1376 				 * know when there's more space available, so
1377 				 * just drop the rest of the data.
1378 				 */
1379 				get += cc << 1;
1380 				if (get >= end)
1381 					get -= sbscn_rbuf_size << 1;
1382 				cc = 0;
1383 			} else {
1384 				/*
1385 				 * Don't schedule any more receive processing
1386 				 * until the line discipline tells us there's
1387 				 * space available (through comhwiflow()).
1388 				 * Leave the rest of the data in the input
1389 				 * buffer.
1390 				 */
1391 				SET(ch->ch_rx_flags, RX_TTY_OVERFLOWED);
1392 			}
1393 			break;
1394 		}
1395 		get += 2;
1396 		if (get >= end)
1397 			get = ch->ch_rbuf;
1398 		cc--;
1399 	}
1400 
1401 	if (cc != scc) {
1402 		ch->ch_rbget = get;
1403 		s = splserial();
1404 		cc = ch->ch_rbavail += scc - cc;
1405 		/* Buffers should be ok again, release possible block. */
1406 		if (cc >= ch->ch_r_lowat) {
1407 			if (ISSET(ch->ch_rx_flags, RX_IBUF_OVERFLOWED)) {
1408 				CLR(ch->ch_rx_flags, RX_IBUF_OVERFLOWED);
1409 				SET(ch->ch_imr, 0x02);
1410 				WRITE_REG(ch->ch_imr_base, ch->ch_imr);
1411 			}
1412 			if (ISSET(ch->ch_rx_flags, RX_IBUF_BLOCKED)) {
1413 				CLR(ch->ch_rx_flags, RX_IBUF_BLOCKED);
1414 				sbscn_dohwiflow(ch);
1415 			}
1416 		}
1417 		splx(s);
1418 	}
1419 }
1420 
1421 integrate void
1422 sbscn_txsoft(struct sbscn_channel *ch, struct tty *tp)
1423 {
1424 
1425 	CLR(tp->t_state, TS_BUSY);
1426 	if (ISSET(tp->t_state, TS_FLUSH))
1427 		CLR(tp->t_state, TS_FLUSH);
1428 	else
1429 		ndflush(&tp->t_outq, (int)(ch->ch_tba - tp->t_outq.c_cf));
1430 	(*tp->t_linesw->l_start)(tp);
1431 }
1432 
1433 integrate void
1434 sbscn_stsoft(struct sbscn_channel *ch, struct tty *tp)
1435 {
1436 	u_char iports, delta;
1437 	int s;
1438 
1439 	s = splserial();
1440 	iports = ch->ch_iports;
1441 	delta = ch->ch_iports_delta;
1442 	ch->ch_iports_delta = 0;
1443 	splx(s);
1444 
1445 	if (ISSET(delta, ch->ch_i_dcd)) {
1446 		/*
1447 		 * Inform the tty layer that carrier detect changed.
1448 		 */
1449 		(void) (*tp->t_linesw->l_modem)(tp,
1450 		    ISSET(iports, ch->ch_i_dcd));
1451 	}
1452 
1453 	if (ISSET(delta, ch->ch_i_cts)) {
1454 		/* Block or unblock output according to flow control. */
1455 		if (ISSET(iports, ch->ch_i_cts)) {
1456 			ch->ch_tx_stopped = 0;
1457 			(*tp->t_linesw->l_start)(tp);
1458 		} else {
1459 			ch->ch_tx_stopped = 1;
1460 		}
1461 	}
1462 
1463 #ifdef SBSCN_DEBUG
1464 	if (sbscn_debug)
1465 		sbscn_status(ch, "sbscn_stsoft");
1466 #endif
1467 }
1468 
1469 void
1470 sbscn_soft(void *arg)
1471 {
1472 	struct sbscn_channel *ch = arg;
1473 	struct tty *tp = ch->ch_tty;
1474 
1475 	if (ch->ch_rx_ready) {
1476 		ch->ch_rx_ready = 0;
1477 		sbscn_rxsoft(ch, tp);
1478 	}
1479 
1480 	if (ch->ch_st_check) {
1481 		ch->ch_st_check = 0;
1482 		sbscn_stsoft(ch, tp);
1483 	}
1484 
1485 	if (ch->ch_tx_done) {
1486 		ch->ch_tx_done = 0;
1487 		sbscn_txsoft(ch, tp);
1488 	}
1489 }
1490 
1491 void
1492 sbscn_intr(void *arg, uint32_t status, uint32_t pc)
1493 {
1494 	struct sbscn_channel *ch = arg;
1495 	u_char *put, *end;
1496 	u_int cc;
1497 	u_char isr, sr;
1498 
1499 	/* read ISR */
1500 	isr = READ_REG(ch->ch_isr_base) & ch->ch_imr;
1501 	if (isr == 0)
1502 		return;
1503 
1504 	end = ch->ch_ebuf;
1505 	put = ch->ch_rbput;
1506 	cc = ch->ch_rbavail;
1507 
1508 	do {
1509 		u_char	iports, delta;
1510 
1511 		if (isr & 0x02) {
1512 
1513 			sr = READ_REG(ch->ch_base + 0x20);
1514 			/* XXX sr 0x01 bit must be set at this point */
1515 
1516 #if defined(DDB) || defined(KGDB)
1517 			if ((sr & 0x80) == 0x80) {
1518 #ifdef DDB
1519 				if (ISSET(ch->ch_hwflags, SBSCN_HW_CONSOLE)) {
1520 					(void)READ_REG(ch->ch_base + 0x60);
1521 					console_debugger();
1522 					continue;
1523 				}
1524 #endif
1525 #ifdef KGDB
1526 				if (ISSET(ch->ch_hwflags, SBSCN_HW_KGDB)) {
1527 					(void)READ_REG(ch->ch_base + 0x60);
1528 					kgdb_connect(1);
1529 					continue;
1530 				}
1531 #endif
1532 			}
1533 #endif /* DDB || KGDB */
1534 
1535 		    	if (!ISSET(ch->ch_rx_flags, RX_IBUF_OVERFLOWED)) {
1536 				while (cc > 0) {
1537 					put[0] = READ_REG(ch->ch_base + 0x60);
1538 					put[1] = sr;
1539 					put += 2;
1540 					if (put >= end)
1541 						put = ch->ch_rbuf;
1542 					cc--;
1543 
1544 					sr = READ_REG(ch->ch_base + 0x20);
1545 					if (!ISSET(sr, 0x02))
1546 						break;
1547 				}
1548 
1549 				/*
1550 				 * Current string of incoming characters ended
1551 				 * because no more data was available or we
1552 				 * ran out of space.  Schedule a receive event
1553 				 * if any data was received.  If we're out of
1554 				 * space, turn off receive interrupts.
1555 				 */
1556 				ch->ch_rbput = put;
1557 				ch->ch_rbavail = cc;
1558 				if (!ISSET(ch->ch_rx_flags, RX_TTY_OVERFLOWED))
1559 					ch->ch_rx_ready = 1;
1560 
1561 				/*
1562 				 * See if we are in danger of overflowing a
1563 				 * buffer. If so, use hardware flow control
1564 				 * to ease the pressure.
1565 				 */
1566 				if (!ISSET(ch->ch_rx_flags, RX_IBUF_BLOCKED) &&
1567 				    cc < ch->ch_r_hiwat) {
1568 					SET(ch->ch_rx_flags, RX_IBUF_BLOCKED);
1569 					sbscn_dohwiflow(ch);
1570 				}
1571 
1572 				/*
1573 				 * If we're out of space, disable receive
1574 				 * interrupts until the queue has drained
1575 				 * a bit.
1576 				 */
1577 				if (!cc) {
1578 					SET(ch->ch_rx_flags,
1579 					    RX_IBUF_OVERFLOWED);
1580 					CLR(ch->ch_imr, 0x02);
1581 					WRITE_REG(ch->ch_imr_base, ch->ch_imr);
1582 				}
1583 			} else {
1584 				/* XXX panic? */
1585 				CLR(ch->ch_imr, 0x02);
1586 				WRITE_REG(ch->ch_imr_base, ch->ch_imr);
1587 				continue;
1588 			}
1589 		}
1590 
1591 		if (isr & 0x01) {
1592 			CLR(ch->ch_imr, 0x01);
1593 			WRITE_REG(ch->ch_imr_base, ch->ch_imr);
1594 		}
1595 
1596 #if 0
1597 XXX
1598 		if (isr & 0x08) {
1599 			clear input signal change!
1600 		}
1601 #endif
1602 		iports = GET_INPUT_SIGNALS(ch);
1603 		delta = iports ^ ch->ch_iports;
1604 		ch->ch_iports = iports;
1605 
1606 		/*
1607 		 * Process normal status changes
1608 		 */
1609 		if (ISSET(delta, ch->ch_i_mask)) {
1610 			SET(ch->ch_iports_delta, delta);
1611 
1612 			/*
1613 			 * Stop output immediately if we lose the output
1614 			 * flow control signal or carrier detect.
1615 			 */
1616 			if (ISSET(~iports, ch->ch_i_mask)) {
1617 				ch->ch_tbc = 0;
1618 				ch->ch_heldtbc = 0;
1619 #ifdef SBSCN_DEBUG
1620 				if (sbscn_debug)
1621 					sbscn_status(ch, "sbscn_intr  ");
1622 #endif
1623 			}
1624 
1625 			ch->ch_st_check = 1;
1626 		}
1627 	} while ((isr = (READ_REG(ch->ch_isr_base) & ch->ch_imr)) != 0);
1628 
1629 	/*
1630 	 * Done handling any receive interrupts and status changes, and
1631 	 * clearing the tx-ready interrupt if it was set.  See if data can
1632 	 * be transmitted as well. Schedule tx done event if no data left
1633 	 * and tty was marked busy.
1634 	 */
1635 	sr = READ_REG(ch->ch_base + 0x20);
1636 	if (ISSET(sr, 0x4)) {
1637 
1638 		/*
1639 		 * If we've delayed a parameter change, do it now, and restart
1640 		 * output.
1641 		 */
1642 		if (ch->ch_heldchange) {
1643 			sbscn_loadchannelregs(ch);
1644 			ch->ch_heldchange = 0;
1645 			ch->ch_tbc = ch->ch_heldtbc;
1646 			ch->ch_heldtbc = 0;
1647 		}
1648 
1649 		/* Output the next chunk of the contiguous buffer, if any. */
1650 		if (ch->ch_tbc > 0) {
1651 			int wrote1;
1652 			u_char c;
1653 
1654 			wrote1 = 0;
1655 			while (ch->ch_tbc &&
1656 			    READ_REG(ch->ch_base + 0x20) & 0x04) {
1657 				wrote1 = 1;
1658 				c = *ch->ch_tba++;
1659 				ch->ch_tbc--;
1660 				WRITE_REG(ch->ch_base + 0x70, c);
1661 			}
1662 			if (wrote1) {
1663 				SET(ch->ch_imr, 0x01);
1664 				WRITE_REG(ch->ch_imr_base, ch->ch_imr);
1665 			}
1666 		} else {
1667 			/*
1668 			 * transmit completion interrupts already disabled,
1669 			 * mark the channel tx state as done.
1670 			 */
1671 			if (ch->ch_tx_busy) {
1672 				ch->ch_tx_busy = 0;
1673 				ch->ch_tx_done = 1;
1674 			}
1675 		}
1676 	}
1677 
1678 	/* Wake up the poller. */
1679 	softintr_schedule(ch->ch_si);
1680 
1681 #if NRND > 0 && defined(RND_SBSCN)
1682 	rnd_add_uint32(&ch->ch_rnd_source, isr | sr);
1683 #endif
1684 }
1685 
1686 /*
1687  * The following functions are polled getc and putc routines, shared
1688  * by the console and kgdb glue.
1689  */
1690 
1691 int
1692 sbscn_common_getc(u_long addr, int chan)
1693 {
1694 	int s = splhigh();
1695 	u_long base = MIPS_PHYS_TO_KSEG1(addr + (chan * 0x100));
1696 	int c;
1697 
1698 	/* block until a character becomes available */
1699 	while ((READ_REG(base + 0x20) & 0x01) == 0)
1700 		continue;
1701 
1702 	c = READ_REG(base + 0x60) & 0xff;
1703 	splx(s);
1704 	return (c);
1705 }
1706 
1707 void
1708 sbscn_common_putc(u_long addr, int chan, int c)
1709 {
1710 	int s = splhigh();
1711 	int timo;
1712 	u_long base = MIPS_PHYS_TO_KSEG1(addr + (chan * 0x100));
1713 
1714 	/* wait for any pending transmission to finish */
1715 	timo = 1500000;
1716 	while ((READ_REG(base + 0x20) & 0x08) == 0 && --timo)
1717 		continue;
1718 
1719 	WRITE_REG(base + 0x70, c);
1720 
1721 	/* wait for this transmission to complete */
1722 	timo = 15000000;
1723 	while ((READ_REG(base + 0x20) & 0x08) == 0 && --timo)
1724 		continue;
1725 
1726 	splx(s);
1727 }
1728 
1729 /*
1730  * Initialize UART for use as console or KGDB line.
1731  */
1732 int
1733 sbscn_init(u_long addr, int chan, int rate, tcflag_t cflag)
1734 {
1735 #if 1
1736 	u_long chanregbase = MIPS_PHYS_TO_KSEG1(addr + (chan * 0x100));
1737 	u_long imaskreg = MIPS_PHYS_TO_KSEG1(addr + 0x230 + (chan * 0x20));
1738 	u_char mode1, mode2;
1739 	u_long brc;
1740 	volatile int timo;
1741 
1742 	WRITE_REG(imaskreg, 0);			/* disable channel intrs */
1743 
1744 	/* XXX should we really do the following?  how about only if enabled? */
1745 	/* wait for any pending transmission to finish */
1746 	timo = 1500000;
1747 	while ((READ_REG(chanregbase + 0x20) & 0x08) == 0 && --timo)
1748 		continue;
1749 
1750 	/* XXX: wait a little.  THIS SHOULD NOT BE NECESSARY!!! (?) */
1751 	timo = 1500000;
1752 	while (--timo)
1753 		;
1754 
1755 	WRITE_REG(chanregbase + 0x50, 2 << 4);	/* reset receiver */
1756 	WRITE_REG(chanregbase + 0x50, 3 << 4);	/* reset transmitter */
1757 
1758 	/* set up the line for use */
1759 	(void)cflag2modes(cflag, &mode1, &mode2);
1760 	(void)sbscn_speed(rate, &brc);
1761 	WRITE_REG(chanregbase + 0x00, mode1);
1762 	WRITE_REG(chanregbase + 0x10, mode2);
1763 	WRITE_REG(chanregbase + 0x30, brc);
1764 
1765 	/* enable transmit and receive */
1766 #define	M_DUART_RX_EN			0x01
1767 #define	M_DUART_TX_EN			0x04
1768 	WRITE_REG(chanregbase + 0x50,M_DUART_RX_EN | M_DUART_TX_EN);
1769 #endif
1770 
1771 	/* XXX: wait a little.  THIS SHOULD NOT BE NECESSARY!!! (?) */
1772 	timo = 1500000;
1773 	while (--timo)
1774 		;
1775 
1776 #if 0 /* XXXCGD */
1777 	bus_space_handle_t ioh;
1778 
1779 	if (bus_space_map(iot, iobase, COM_NPORTS, 0, &ioh))
1780 		return (ENOMEM); /* ??? */
1781 
1782 	bus_space_write_1(iot, ioh, com_lcr, LCR_EERS);
1783 	bus_space_write_1(iot, ioh, com_efr, 0);
1784 	bus_space_write_1(iot, ioh, com_lcr, LCR_DLAB);
1785 	rate = comspeed(rate, frequency);
1786 	bus_space_write_1(iot, ioh, com_dlbl, rate);
1787 	bus_space_write_1(iot, ioh, com_dlbh, rate >> 8);
1788 	bus_space_write_1(iot, ioh, com_lcr, cflag2lcr(cflag));
1789 	bus_space_write_1(iot, ioh, com_mcr, MCR_DTR | MCR_RTS);
1790 	bus_space_write_1(iot, ioh, com_fifo,
1791 	    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_1);
1792 	bus_space_write_1(iot, ioh, com_ier, 0);
1793 
1794 	*iohp = ioh;
1795 	return (0);
1796 #endif /* XXXCGD */
1797 	/* XXXCGD */
1798 	return (0);
1799 }
1800 
1801 /*
1802  * Following are all routines needed for sbscn to act as console
1803  */
1804 int
1805 sbscn_cnattach(u_long addr, int chan, int rate, tcflag_t cflag)
1806 {
1807 	int res;
1808 	static struct consdev sbscn_cons = {
1809 		NULL, NULL, sbscn_cngetc, sbscn_cnputc, sbscn_cnpollc, NULL,
1810 		    NULL, NULL, NODEV, CN_NORMAL
1811 	};
1812 
1813 	res = sbscn_init(addr, chan, rate, cflag);
1814 	if (res)
1815 		return (res);
1816 
1817 	cn_tab = &sbscn_cons;
1818 
1819 	sbscn_cons_present = 1;
1820 	sbscn_cons_addr = addr;
1821 	sbscn_cons_chan = chan;
1822 	sbscn_cons_rate = rate;
1823 	sbscn_cons_cflag = cflag;
1824 
1825 	return (0);
1826 }
1827 
1828 int
1829 sbscn_cngetc(dev_t dev)
1830 {
1831 
1832 	return (sbscn_common_getc(sbscn_cons_addr, sbscn_cons_chan));
1833 }
1834 
1835 /*
1836  * Console kernel output character routine.
1837  */
1838 void
1839 sbscn_cnputc(dev_t dev, int c)
1840 {
1841 
1842 	sbscn_common_putc(sbscn_cons_addr, sbscn_cons_chan, c);
1843 }
1844 
1845 void
1846 sbscn_cnpollc(dev_t dev, int on)
1847 {
1848 
1849 }
1850 
1851 #ifdef KGDB
1852 int
1853 sbscn_kgdb_attach(u_long addr, int chan, int rate, tcflag_t cflag)
1854 {
1855 	int res;
1856 
1857 	if (!sbscn_cons_present &&
1858 	    sbscn_cons_addr == addr && sbscn_cons_chan == chan)
1859 		return (EBUSY); /* cannot share with console */
1860 
1861 	res = sbscn_init(addr, chan, rate, cflag);
1862 	if (res)
1863 		return (res);
1864 
1865 	kgdb_attach(sbscn_kgdb_getc, sbscn_kgdb_putc, NULL);
1866 	kgdb_dev = 123; /* unneeded, only to satisfy some tests */
1867 
1868 	sbscn_kgdb_present = 1;
1869 	sbscn_kgdb_addr = addr;
1870 	sbscn_kgdb_chan = chan;
1871 
1872 	return (0);
1873 }
1874 
1875 /* ARGSUSED */
1876 int
1877 sbscn_kgdb_getc(arg)
1878 	void *arg;
1879 {
1880 
1881 	return (sbscn_common_getc(sbscn_kgdb_addr, sbscn_kgdb_chan));
1882 }
1883 
1884 /* ARGSUSED */
1885 void
1886 sbscn_kgdb_putc(arg, c)
1887 	void *arg;
1888 	int c;
1889 {
1890 
1891 	sbscn_common_getc(sbscn_kgdb_addr, sbscn_kgdb_chan, c);
1892 }
1893 #endif /* KGDB */
1894 
1895 /*
1896  * helper function to identify the sbscn channels used by
1897  * console or KGDB (and not yet autoconf attached)
1898  */
1899 int
1900 sbscn_is_console(u_long addr, int chan)
1901 {
1902 
1903 	if (sbscn_cons_present && !sbscn_cons_attached &&
1904 	    sbscn_cons_addr == addr && sbscn_cons_chan == chan)
1905 		return (1);
1906 #ifdef KGDB
1907 	if (sbscn_kgdb_present && !sbscn_kgdb_attached &&
1908 	    sbscn_kgdb_addr == addr && sbscn_kgdb_chan == chan)
1909 		return (1);
1910 #endif
1911 	return (0);
1912 }
1913