xref: /netbsd-src/sys/arch/mips/sibyte/dev/sbscn.c (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
1 /* $NetBSD: sbscn.c,v 1.43 2017/07/24 09:56:46 mrg 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 /* from: $NetBSD: com.c,v 1.172 2000/05/03 19:19:04 thorpej Exp */
36 
37 /*-
38  * Copyright (c) 1998, 1999 The NetBSD Foundation, Inc.
39  * All rights reserved.
40  *
41  * This code is derived from software contributed to The NetBSD Foundation
42  * by Charles M. Hannum.
43  *
44  * Redistribution and use in source and binary forms, with or without
45  * modification, are permitted provided that the following conditions
46  * are met:
47  * 1. Redistributions of source code must retain the above copyright
48  *    notice, this list of conditions and the following disclaimer.
49  * 2. Redistributions in binary form must reproduce the above copyright
50  *    notice, this list of conditions and the following disclaimer in the
51  *    documentation and/or other materials provided with the distribution.
52  *
53  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
54  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
55  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
56  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
57  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
58  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
59  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
60  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
61  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
62  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
63  * POSSIBILITY OF SUCH DAMAGE.
64  */
65 
66 /*
67  * Copyright (c) 1991 The Regents of the University of California.
68  * All rights reserved.
69  *
70  * Redistribution and use in source and binary forms, with or without
71  * modification, are permitted provided that the following conditions
72  * are met:
73  * 1. Redistributions of source code must retain the above copyright
74  *    notice, this list of conditions and the following disclaimer.
75  * 2. Redistributions in binary form must reproduce the above copyright
76  *    notice, this list of conditions and the following disclaimer in the
77  *    documentation and/or other materials provided with the distribution.
78  * 3. Neither the name of the University nor the names of its contributors
79  *    may be used to endorse or promote products derived from this software
80  *    without specific prior written permission.
81  *
82  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
83  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
84  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
85  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
86  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
87  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
88  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
89  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
90  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
91  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
92  * SUCH DAMAGE.
93  *
94  *	@(#)com.c	7.5 (Berkeley) 5/16/91
95  */
96 
97 /*
98  * `sbscn' driver, supports SiByte SB-1250 SOC DUART.
99  *
100  * This DUART is quite similar in programming model to the scn2681/68681
101  * DUARTs supported by the NetBSD/amiga `mfc' and NetBSD/pc532 `scn'
102  * driver, but substantial rework would have been necessary to make
103  * those drivers sane w.r.t. bus_space (which would then have been
104  * required on NetBSD/sbmips very early on), and to accommodate the
105  * different register mappings.
106  *
107  * So, another driver.  Eventually there should be One True Driver,
108  * but we're not here to save the world.
109  */
110 
111 #include <sys/cdefs.h>
112 __KERNEL_RCSID(0, "$NetBSD: sbscn.c,v 1.43 2017/07/24 09:56:46 mrg Exp $");
113 
114 #define	SBSCN_DEBUG
115 
116 #include "opt_ddb.h"
117 #include "ioconf.h"
118 
119 #ifdef RND_SBSCN
120 #include <sys/rndsource.h>
121 #endif
122 
123 #include <sys/param.h>
124 #include <sys/systm.h>
125 #include <sys/ioctl.h>
126 #include <sys/select.h>
127 #include <sys/tty.h>
128 #include <sys/proc.h>
129 #include <sys/conf.h>
130 #include <sys/file.h>
131 #include <sys/uio.h>
132 #include <sys/kernel.h>
133 #include <sys/syslog.h>
134 #include <sys/types.h>
135 #include <sys/device.h>
136 #include <sys/malloc.h>
137 #include <sys/vnode.h>
138 #include <sys/kauth.h>
139 #include <sys/intr.h>
140 
141 #include <mips/sibyte/dev/sbobiovar.h>
142 #if 0
143 #include <mips/sibyte/dev/sbscnreg.h>
144 #endif
145 #include <mips/sibyte/dev/sbscnvar.h>
146 #include <dev/cons.h>
147 #include <mips/locore.h>
148 
149 #include <evbmips/sbmips/systemsw.h>
150 
151 void	sbscn_attach_channel(struct sbscn_softc *sc, int chan, int intr);
152 #if defined(DDB) || defined(KGDB)
153 static void sbscn_enable_debugport(struct sbscn_channel *ch);
154 #endif
155 void	sbscn_config(struct sbscn_channel *ch);
156 void	sbscn_shutdown(struct sbscn_channel *ch);
157 int	sbscn_speed(long, long *);
158 static int cflag2modes(tcflag_t, u_char *, u_char *);
159 int	sbscn_param(struct tty *, struct termios *);
160 void	sbscn_start(struct tty *);
161 int	sbscn_hwiflow(struct tty *, int);
162 
163 void	sbscn_loadchannelregs(struct sbscn_channel *);
164 void	sbscn_dohwiflow(struct sbscn_channel *);
165 void	sbscn_break(struct sbscn_channel *, int);
166 void	sbscn_modem(struct sbscn_channel *, int);
167 void	tiocm_to_sbscn(struct sbscn_channel *, int, int);
168 int	sbscn_to_tiocm(struct sbscn_channel *);
169 void	sbscn_iflush(struct sbscn_channel *);
170 
171 int	sbscn_init(u_long addr, int chan, int rate, tcflag_t cflag);
172 int	sbscn_common_getc(u_long addr, int chan);
173 void	sbscn_common_putc(u_long addr, int chan, int c);
174 void	sbscn_intr(void *arg, uint32_t status, vaddr_t pc);
175 
176 int	sbscn_cngetc(dev_t dev);
177 void	sbscn_cnputc(dev_t dev, int c);
178 void	sbscn_cnpollc(dev_t dev, int on);
179 
180 dev_type_open(sbscnopen);
181 dev_type_close(sbscnclose);
182 dev_type_read(sbscnread);
183 dev_type_write(sbscnwrite);
184 dev_type_ioctl(sbscnioctl);
185 dev_type_stop(sbscnstop);
186 dev_type_tty(sbscntty);
187 dev_type_poll(sbscnpoll);
188 
189 const struct cdevsw sbscn_cdevsw = {
190 	.d_open = sbscnopen,
191 	.d_close = sbscnclose,
192 	.d_read = sbscnread,
193 	.d_write = sbscnwrite,
194 	.d_ioctl = sbscnioctl,
195 	.d_stop = sbscnstop,
196 	.d_tty = sbscntty,
197 	.d_poll = sbscnpoll,
198 	.d_mmap = nommap,
199 	.d_kqfilter = ttykqfilter,
200 	.d_discard = nodiscard,
201 	.d_flag = D_TTY
202 };
203 
204 #define	integrate	static inline
205 void 	sbscn_soft(void *);
206 integrate void sbscn_rxsoft(struct sbscn_channel *, struct tty *);
207 integrate void sbscn_txsoft(struct sbscn_channel *, struct tty *);
208 integrate void sbscn_stsoft(struct sbscn_channel *, struct tty *);
209 integrate void sbscn_schedrx(struct sbscn_channel *);
210 void	sbscn_diag(void *);
211 
212 /*
213  * Make this an option variable one can patch.
214  * But be warned:  this must be a power of 2!
215  */
216 u_int sbscn_rbuf_size = SBSCN_RING_SIZE;
217 
218 /* Stop input when 3/4 of the ring is full; restart when only 1/4 is full. */
219 u_int sbscn_rbuf_hiwat = (SBSCN_RING_SIZE * 1) / 4;
220 u_int sbscn_rbuf_lowat = (SBSCN_RING_SIZE * 3) / 4;
221 
222 static int	sbscn_cons_present;
223 static int	sbscn_cons_attached;
224 static u_long	sbscn_cons_addr;
225 static int	sbscn_cons_chan;
226 static int	sbscn_cons_rate;
227 static tcflag_t	sbscn_cons_cflag;
228 
229 #ifdef KGDB
230 #include <sys/kgdb.h>
231 
232 static int	sbscn_kgdb_present;
233 static int	sbscn_kgdb_attached;
234 static u_long	sbscn_kgdb_addr;
235 static int	sbscn_kgdb_chan;
236 
237 int	sbscn_kgdb_getc(void *);
238 void	sbscn_kgdb_putc(void *, int);
239 #endif /* KGDB */
240 
241 static int	sbscn_match(device_t, cfdata_t, void *);
242 static void	sbscn_attach(device_t, device_t, void *);
243 
244 CFATTACH_DECL_NEW(sbscn, sizeof(struct sbscn_softc),
245     sbscn_match, sbscn_attach, NULL, NULL);
246 
247 #define	READ_REG(rp)		(mips3_ld((register_t)(rp)))
248 #define	WRITE_REG(rp, val)	(mips3_sd((register_t)(rp), (val)))
249 
250 /*
251  * input and output signals are actually the _inverse_ of the bits in the
252  * input and output port registers!
253  */
254 #define	GET_INPUT_SIGNALS(ch) \
255     ((~READ_REG(MIPS_PHYS_TO_KSEG1((ch)->ch_sc->sc_addr + 0x280))) & (ch)->ch_i_mask)
256 #define	SET_OUTPUT_SIGNALS(ch, val) 					\
257     do {								\
258 	int sigs_to_set, sigs_to_clr;					\
259 									\
260 	sigs_to_set = (ch)->ch_o_mask & val;				\
261 	sigs_to_clr = (ch)->ch_o_mask & ~val;				\
262 									\
263 	/* set signals by clearing op bits, and vice versa */		\
264 	WRITE_REG(MIPS_PHYS_TO_KSEG1((ch)->ch_sc->sc_addr + 0x2c0),	\
265 	    sigs_to_set);						\
266 	WRITE_REG(MIPS_PHYS_TO_KSEG1((ch)->ch_sc->sc_addr + 0x2b0),	\
267 	    sigs_to_clr);						\
268     } while (0)
269 
270 static int
271 sbscn_match(device_t parent, cfdata_t match, void *aux)
272 {
273 	struct sbobio_attach_args *sa = aux;
274 
275 	if (sa->sa_locs.sa_type != SBOBIO_DEVTYPE_DUART)
276 		return (0);
277 
278 	return 1;
279 }
280 
281 static void
282 sbscn_attach(device_t parent, device_t self, void *aux)
283 {
284 	struct sbscn_softc *sc = device_private(self);
285 	struct sbobio_attach_args *sa = aux;
286 	int i;
287 
288 	sc->sc_dev = self;
289 	sc->sc_addr = sa->sa_base + sa->sa_locs.sa_offset;
290 
291 	aprint_normal("\n");
292 	for (i = 0; i < 2; i++)
293 		sbscn_attach_channel(sc, i, sa->sa_locs.sa_intr[i]);
294 
295 	/* init duart_opcr */
296 	WRITE_REG(MIPS_PHYS_TO_KSEG1(sc->sc_addr + 0x270), 0);
297 	/* init duart_aux_ctrl */
298 	WRITE_REG(MIPS_PHYS_TO_KSEG1(sc->sc_addr + 0x210), 0x0f); /* XXX */
299 }
300 
301 void
302 sbscn_attach_channel(struct sbscn_softc *sc, int chan, int intr)
303 {
304 	struct sbscn_channel *ch = &sc->sc_channels[chan];
305 	u_long chan_addr;
306 	struct tty *tp;
307 
308 	ch->ch_sc = sc;
309 	ch->ch_num = chan;
310 
311 	chan_addr = sc->sc_addr + (0x100 * chan);
312 	ch->ch_base = (void *)MIPS_PHYS_TO_KSEG1(chan_addr);
313 	ch->ch_isr_base =
314 	    (void *)MIPS_PHYS_TO_KSEG1(sc->sc_addr + 0x220 + (0x20 * chan));
315 	ch->ch_imr_base =
316 	    (void *)MIPS_PHYS_TO_KSEG1(sc->sc_addr + 0x230 + (0x20 * chan));
317 #ifdef XXXCGDnotyet
318 	ch->ch_inchg_base =
319 	    (void *)MIPS_PHYS_TO_KSEG1(sc->sc_addr + 0x2d0 + (0x10 * chan));
320 #endif
321 
322 	ch->ch_i_dcd = ch->ch_i_dcd_pin = 0 /* XXXCGD */;
323 	ch->ch_i_cts = ch->ch_i_cts_pin = 0 /* XXXCGD */;
324 	ch->ch_i_dsr = ch->ch_i_dsr_pin = 0 /* XXXCGD */;
325 	ch->ch_i_ri = ch->ch_i_ri_pin = 0 /* XXXCGD */;
326 	ch->ch_i_mask =
327 	    ch->ch_i_dcd | ch->ch_i_cts | ch->ch_i_dsr | ch->ch_i_ri;
328 	ch->ch_o_dtr = ch->ch_o_dtr_pin = 0 /* XXXCGD */;
329 	ch->ch_o_rts = ch->ch_o_rts_pin = 0 /* XXXCGD */;
330 	ch->ch_o_mask = ch->ch_o_dtr | ch->ch_o_rts;
331 
332 	ch->ch_intrhand = cpu_intr_establish(intr, IPL_SERIAL, sbscn_intr, ch);
333 	callout_init(&ch->ch_diag_callout, 0);
334 
335 	/* Disable interrupts before configuring the device. */
336 	ch->ch_imr = 0;
337 	WRITE_REG(ch->ch_imr_base, ch->ch_imr);
338 
339 	if (sbscn_cons_present &&
340 	    sbscn_cons_addr == chan_addr && sbscn_cons_chan == chan) {
341 		sbscn_cons_attached = 1;
342 
343 		/* Make sure the console is always "hardwired". */
344 		delay(1000);			/* wait for output to finish */
345 		SET(ch->ch_hwflags, SBSCN_HW_CONSOLE);
346 		SET(ch->ch_swflags, TIOCFLAG_SOFTCAR);
347 	}
348 
349 	tp = tty_alloc();
350 	tp->t_oproc = sbscn_start;
351 	tp->t_param = sbscn_param;
352 	tp->t_hwiflow = sbscn_hwiflow;
353 
354 	ch->ch_tty = tp;
355 	ch->ch_rbuf = malloc(sbscn_rbuf_size << 1, M_DEVBUF, M_NOWAIT);
356 	if (ch->ch_rbuf == NULL) {
357 		aprint_error_dev(sc->sc_dev,
358 		    "channel %d: unable to allocate ring buffer\n",
359 		    chan);
360 		return;
361 	}
362 	ch->ch_ebuf = ch->ch_rbuf + (sbscn_rbuf_size << 1);
363 
364 	tty_attach(tp);
365 
366 	if (ISSET(ch->ch_hwflags, SBSCN_HW_CONSOLE)) {
367 		int maj;
368 
369 		/* locate the major number */
370 		maj = cdevsw_lookup_major(&sbscn_cdevsw);
371 
372 		cn_tab->cn_dev = makedev(maj,
373 		    (device_unit(sc->sc_dev) << 1) + chan);
374 
375 		aprint_normal_dev(sc->sc_dev, "channel %d: %s\n",
376 		    chan, "console");
377 	}
378 
379 #ifdef KGDB
380 	/*
381 	 * Allow kgdb to "take over" this port.  If this is
382 	 * the kgdb device, it has exclusive use.
383 	 */
384 	if (sbscn_kgdb_present &&
385 	    sbscn_kgdb_addr == chan_addr && sbscn_kgdb_chan == chan) {
386 		sbscn_kgdb_attached = 1;
387 
388 		SET(sc->sc_hwflags, SBSCN_HW_KGDB);
389 		aprint_normal_dev(sc->sc_dev, "channel %d: %s\n",
390 		    chan, "kgdb");
391 	}
392 #endif
393 
394 	ch->ch_si = softint_establish(SOFTINT_SERIAL, sbscn_soft, ch);
395 
396 #ifdef RND_SBSCN
397 	rnd_attach_source(&ch->ch_rnd_source, device_xname(sc->sc_dev),
398 			  RND_TYPE_TTY, RND_FLAG_COLLECT_TIME|
399 					RND_FLAG_ESTIMATE_TIME);
400 #endif
401 
402 	sbscn_config(ch);
403 
404 	SET(ch->ch_hwflags, SBSCN_HW_DEV_OK);
405 }
406 
407 int
408 sbscn_speed(long speed, long *brcp)
409 {
410 #define	divrnd(n, q)	(((n)*2/(q)+1)/2)	/* divide and round off */
411 
412 	int x, err;
413 	int frequency = 100000000;
414 
415 	*brcp = divrnd(frequency / 20, speed) - 1;
416 
417 	if (speed <= 0)
418 		return (-1);
419 	x = divrnd(frequency / 20, speed);
420 	if (x <= 0)
421 		return (-1);
422 	err = divrnd(((quad_t)frequency) * 1000 / 20, speed * x) - 1000;
423 	if (err < 0)
424 		err = -err;
425 	if (err > SBSCN_TOLERANCE)
426 		return (-1);
427 	*brcp = x - 1;
428 	return (0);
429 
430 #undef	divrnd
431 }
432 
433 #ifdef SBSCN_DEBUG
434 void	sbscn_status(struct sbscn_channel *, const char *);
435 
436 int	sbscn_debug = 0 /* XXXCGD */;
437 
438 void
439 sbscn_status(struct sbscn_channel *ch, const char *str)
440 {
441 	struct sbscn_softc *sc = ch->ch_sc;
442 	struct tty *tp = ch->ch_tty;
443 
444 	aprint_normal_dev(sc->sc_dev,
445 	    "chan %d: %s %sclocal  %sdcd %sts_carr_on %sdtr %stx_stopped\n",
446 	    ch->ch_num, str,
447 	    ISSET(tp->t_cflag, CLOCAL) ? "+" : "-",
448 	    ISSET(ch->ch_iports, ch->ch_i_dcd) ? "+" : "-",
449 	    ISSET(tp->t_state, TS_CARR_ON) ? "+" : "-",
450 	    ISSET(ch->ch_oports, ch->ch_o_dtr) ? "+" : "-",
451 	    ch->ch_tx_stopped ? "+" : "-");
452 
453 	aprint_normal_dev(sc->sc_dev,
454 	    "chan %d: %s %scrtscts %scts %sts_ttstop  %srts %xrx_flags\n",
455 	    ch->ch_num, str,
456 	    ISSET(tp->t_cflag, CRTSCTS) ? "+" : "-",
457 	    ISSET(ch->ch_iports, ch->ch_i_cts) ? "+" : "-",
458 	    ISSET(tp->t_state, TS_TTSTOP) ? "+" : "-",
459 	    ISSET(ch->ch_oports, ch->ch_o_rts) ? "+" : "-",
460 	    ch->ch_rx_flags);
461 }
462 #endif
463 
464 #if defined(DDB) || defined(KGDB)
465 static void
466 sbscn_enable_debugport(struct sbscn_channel *ch)
467 {
468 	int s;
469 
470 	/* Turn on line break interrupt, set carrier. */
471 	s = splserial();
472 
473 #if 0	/* DO NOT turn on break interrupt at this time. */
474 	ch->ch_imr = 0x04;
475 #else
476 	ch->ch_imr = 0x00;
477 #endif
478 	WRITE_REG(ch->ch_imr_base, ch->ch_imr);
479 	SET(ch->ch_oports, ch->ch_o_dtr | ch->ch_o_rts);
480 	SET_OUTPUT_SIGNALS(ch, ch->ch_oports);
481 
482 	splx(s);
483 }
484 #endif
485 
486 void
487 sbscn_config(struct sbscn_channel *ch)
488 {
489 
490 	/* Disable interrupts before configuring the device. */
491 	ch->ch_imr = 0x00;
492 	WRITE_REG(ch->ch_imr_base, ch->ch_imr);
493 
494 #ifdef DDB
495 	if (ISSET(ch->ch_hwflags, SBSCN_HW_CONSOLE))
496 		sbscn_enable_debugport(ch);
497 #endif
498 
499 #ifdef KGDB
500 	/*
501 	 * Allow kgdb to "take over" this port.  If this is
502 	 * the kgdb device, it has exclusive use.
503 	 */
504 	if (ISSET(ch->ch_hwflags, SBSCN_HW_KGDB))
505 		sbscn_enable_debugport(ch);
506 #endif
507 }
508 
509 void
510 sbscn_shutdown(struct sbscn_channel *ch)
511 {
512 	struct tty *tp = ch->ch_tty;
513 	int s;
514 
515 	s = splserial();
516 
517 	/* If we were asserting flow control, then deassert it. */
518 	SET(ch->ch_rx_flags, RX_IBUF_BLOCKED);
519 	sbscn_dohwiflow(ch);
520 
521 	/* Clear any break condition set with TIOCSBRK. */
522 	sbscn_break(ch, 0);
523 
524 	/*
525 	 * Hang up if necessary.  Wait a bit, so the other side has time to
526 	 * notice even if we immediately open the port again.
527 	 * Avoid tsleeping above splhigh().
528 	 */
529 	if (ISSET(tp->t_cflag, HUPCL)) {
530 		sbscn_modem(ch, 0);
531 		splx(s);
532 		/* XXX tsleep will only timeout */
533 		(void) tsleep(ch, TTIPRI, ttclos, hz);
534 		s = splserial();
535 	}
536 
537 	/* Turn off interrupts. */
538 #ifdef DDB
539 	if (ISSET(ch->ch_hwflags, SBSCN_HW_CONSOLE))
540 #if 0	/* DO NOT turn on break interrupt at this time. */
541 		ch->ch_imr = 0x04; /* interrupt on break */
542 #else
543 		ch->ch_imr = 0x00;
544 #endif
545 	else
546 #endif
547 		ch->ch_imr = 0;
548 	WRITE_REG(ch->ch_imr_base, ch->ch_imr);
549 
550 	splx(s);
551 }
552 
553 int
554 sbscnopen(dev_t dev, int flag, int mode, struct lwp *l)
555 {
556 	int chan = SBSCN_CHAN(dev);
557 	struct sbscn_softc *sc;
558 	struct sbscn_channel *ch;
559 	struct tty *tp;
560 	int s, s2;
561 	int error;
562 
563 	sc = device_lookup_private(&sbscn_cd, SBSCN_UNIT(dev));
564 	if (sc == NULL)
565 		return (ENXIO);
566 	ch = &sc->sc_channels[chan];
567 	if (!ISSET(ch->ch_hwflags, SBSCN_HW_DEV_OK) || ch->ch_rbuf == NULL)
568 		return (ENXIO);
569 
570 #ifdef KGDB
571 	/*
572 	 * If this is the kgdb port, no other use is permitted.
573 	 */
574 	if (ISSET(ch->ch_hwflags, SBSCN_HW_KGDB))
575 		return (EBUSY);
576 #endif
577 
578 	tp = ch->ch_tty;
579 
580 	if (kauth_authorize_device_tty(l->l_cred, KAUTH_DEVICE_TTY_OPEN, tp))
581 		return (EBUSY);
582 
583 	s = spltty();
584 
585 	/*
586 	 * Do the following iff this is a first open.
587 	 */
588 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
589 		struct termios t;
590 
591 		tp->t_dev = dev;
592 
593 		s2 = splserial();
594 
595 		/* Turn on receive, break, and status change interrupts. */
596 #if 0	/* DO NOT turn on break or status change interrupt at this time. */
597 		ch->ch_imr = 0xe;
598 #else
599 		ch->ch_imr = 0x2;
600 #endif
601 		WRITE_REG(ch->ch_imr_base, ch->ch_imr);
602 
603 		/* Fetch the current modem control status, needed later. */
604 		ch->ch_iports = GET_INPUT_SIGNALS(ch);
605 		ch->ch_iports_delta = 0;
606 		splx(s2);
607 
608 		/*
609 		 * Initialize the termios status to the defaults.  Add in the
610 		 * sticky bits from TIOCSFLAGS.
611 		 */
612 		t.c_ispeed = 0;
613 		if (ISSET(ch->ch_hwflags, SBSCN_HW_CONSOLE)) {
614 			t.c_ospeed = sbscn_cons_rate;
615 			t.c_cflag = sbscn_cons_cflag;
616 		} else {
617 			t.c_ospeed = TTYDEF_SPEED;
618 			t.c_cflag = TTYDEF_CFLAG;
619 		}
620 		if (ISSET(ch->ch_swflags, TIOCFLAG_CLOCAL))
621 			SET(t.c_cflag, CLOCAL);
622 		if (ISSET(ch->ch_swflags, TIOCFLAG_CRTSCTS))
623 			SET(t.c_cflag, CRTSCTS);
624 		if (ISSET(ch->ch_swflags, TIOCFLAG_MDMBUF))
625 			SET(t.c_cflag, MDMBUF);
626 		/* Make sure sbscn_param() will do something. */
627 		tp->t_ospeed = 0;
628 		(void) sbscn_param(tp, &t);
629 		tp->t_iflag = TTYDEF_IFLAG;
630 		tp->t_oflag = TTYDEF_OFLAG;
631 		tp->t_lflag = TTYDEF_LFLAG;
632 		ttychars(tp);
633 		ttsetwater(tp);
634 
635 		s2 = splserial();
636 
637 		/*
638 		 * Turn on DTR.  We must always do this, even if carrier is not
639 		 * present, because otherwise we'd have to use TIOCSDTR
640 		 * immediately after setting CLOCAL, which applications do not
641 		 * expect.  We always assert DTR while the device is open
642 		 * unless explicitly requested to deassert it.
643 		 */
644 		sbscn_modem(ch, 1);
645 
646 		/* Clear the input ring, and unblock. */
647 		ch->ch_rbput = ch->ch_rbget = ch->ch_rbuf;
648 		ch->ch_rbavail = sbscn_rbuf_size;
649 		sbscn_iflush(ch);
650 		CLR(ch->ch_rx_flags, RX_ANY_BLOCK);
651 		sbscn_dohwiflow(ch);
652 
653 #ifdef SBSCN_DEBUG
654 		if (sbscn_debug)
655 			sbscn_status(ch, "sbscnopen  ");
656 #endif
657 
658 		splx(s2);
659 	}
660 
661 	splx(s);
662 
663 	error = ttyopen(tp, SBSCN_DIALOUT(dev), ISSET(flag, O_NONBLOCK));
664 	if (error)
665 		goto bad;
666 
667 	error = (*tp->t_linesw->l_open)(dev, tp);
668 	if (error)
669 		goto bad;
670 
671 	return (0);
672 
673 bad:
674 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
675 		/*
676 		 * We failed to open the device, and nobody else had it opened.
677 		 * Clean up the state as appropriate.
678 		 */
679 		sbscn_shutdown(ch);
680 	}
681 
682 	return (error);
683 }
684 
685 int
686 sbscnclose(dev_t dev, int flag, int mode, struct lwp *l)
687 {
688 	struct sbscn_softc *sc = device_lookup_private(&sbscn_cd, SBSCN_UNIT(dev));
689 	struct sbscn_channel *ch = &sc->sc_channels[SBSCN_CHAN(dev)];
690 	struct tty *tp = ch->ch_tty;
691 
692 	/* XXX This is for cons.c. */
693 	if (!ISSET(tp->t_state, TS_ISOPEN))
694 		return (0);
695 
696 	(*tp->t_linesw->l_close)(tp, flag);
697 	ttyclose(tp);
698 
699 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
700 		/*
701 		 * Although we got a last close, the device may still be in
702 		 * use; e.g. if this was the dialout node, and there are still
703 		 * processes waiting for carrier on the non-dialout node.
704 		 */
705 		sbscn_shutdown(ch);
706 	}
707 
708 	return (0);
709 }
710 
711 int
712 sbscnread(dev_t dev, struct uio *uio, int flag)
713 {
714 	struct sbscn_softc *sc = device_lookup_private(&sbscn_cd, SBSCN_UNIT(dev));
715 	struct sbscn_channel *ch = &sc->sc_channels[SBSCN_CHAN(dev)];
716 	struct tty *tp = ch->ch_tty;
717 
718 	return ((*tp->t_linesw->l_read)(tp, uio, flag));
719 }
720 
721 int
722 sbscnwrite(dev_t dev, struct uio *uio, int flag)
723 {
724 	struct sbscn_softc *sc = device_lookup_private(&sbscn_cd, SBSCN_UNIT(dev));
725 	struct sbscn_channel *ch = &sc->sc_channels[SBSCN_CHAN(dev)];
726 	struct tty *tp = ch->ch_tty;
727 
728 	return ((*tp->t_linesw->l_write)(tp, uio, flag));
729 }
730 
731 int
732 sbscnpoll(dev_t dev, int events, struct lwp *l)
733 {
734 	struct sbscn_softc *sc = device_lookup_private(&sbscn_cd, SBSCN_UNIT(dev));
735 	struct sbscn_channel *ch = &sc->sc_channels[SBSCN_CHAN(dev)];
736 	struct tty *tp = ch->ch_tty;
737 
738 	return ((*tp->t_linesw->l_poll)(tp, events, l));
739 }
740 
741 struct tty *
742 sbscntty(dev_t dev)
743 {
744 	struct sbscn_softc *sc = device_lookup_private(&sbscn_cd, SBSCN_UNIT(dev));
745 	struct sbscn_channel *ch = &sc->sc_channels[SBSCN_CHAN(dev)];
746 	struct tty *tp = ch->ch_tty;
747 
748 	return (tp);
749 }
750 
751 int
752 sbscnioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
753 {
754 	struct sbscn_softc *sc = device_lookup_private(&sbscn_cd, SBSCN_UNIT(dev));
755 	struct sbscn_channel *ch = &sc->sc_channels[SBSCN_CHAN(dev)];
756 	struct tty *tp = ch->ch_tty;
757 	int error;
758 	int s;
759 
760 	error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, l);
761 	if (error != EPASSTHROUGH)
762 		return (error);
763 
764 	error = ttioctl(tp, cmd, data, flag, l);
765 	if (error != EPASSTHROUGH)
766 		return (error);
767 
768 	error = 0;
769 
770 	s = splserial();
771 
772 	switch (cmd) {
773 	case TIOCSBRK:
774 		sbscn_break(ch, 1);
775 		break;
776 
777 	case TIOCCBRK:
778 		sbscn_break(ch, 0);
779 		break;
780 
781 	case TIOCSDTR:
782 		sbscn_modem(ch, 1);
783 		break;
784 
785 	case TIOCCDTR:
786 		sbscn_modem(ch, 0);
787 		break;
788 
789 	case TIOCGFLAGS:
790 		*(int *)data = ch->ch_swflags;
791 		break;
792 
793 	case TIOCSFLAGS:
794 		error = kauth_authorize_device_tty(l->l_cred,
795 		    KAUTH_DEVICE_TTY_PRIVSET, tp);
796 		if (error)
797 			break;
798 		ch->ch_swflags = *(int *)data;
799 		break;
800 
801 	case TIOCMSET:
802 	case TIOCMBIS:
803 	case TIOCMBIC:
804 		tiocm_to_sbscn(ch, cmd, *(int *)data);
805 		break;
806 
807 	case TIOCMGET:
808 		*(int *)data = sbscn_to_tiocm(ch);
809 		break;
810 
811 	default:
812 		error = EPASSTHROUGH;
813 		break;
814 	}
815 
816 	splx(s);
817 
818 #ifdef SBSCN_DEBUG
819 	if (sbscn_debug)
820 		sbscn_status(ch, "sbscn_ioctl ");
821 #endif
822 
823 	return (error);
824 }
825 
826 integrate void
827 sbscn_schedrx(struct sbscn_channel *ch)
828 {
829 
830 	ch->ch_rx_ready = 1;
831 
832 	/* Wake up the poller. */
833 	softint_schedule(ch->ch_si);
834 }
835 
836 void
837 sbscn_break(struct sbscn_channel *ch, int onoff)
838 {
839 
840 /* XXXCGD delay break until not busy */
841 	if (onoff)
842 		WRITE_REG(ch->ch_base + 0x50, 0x60);
843 	else
844 		WRITE_REG(ch->ch_base + 0x50, 0x70);
845 
846 #if 0
847 	if (!ch->ch_heldchange) {
848 		if (ch->ch_tx_busy) {
849 			ch->ch_heldtbc = ch->ch_tbc;
850 			ch->ch_tbc = 0;
851 			ch->ch_heldchange = 1;
852 		} else
853 			sbscn_loadchannelregs(ch);
854 	}
855 #endif
856 }
857 
858 void
859 sbscn_modem(struct sbscn_channel *ch, int onoff)
860 {
861 
862 	if (ch->ch_o_dtr == 0)
863 		return;
864 
865 	if (onoff)
866 		SET(ch->ch_oports, ch->ch_o_dtr);
867 	else
868 		CLR(ch->ch_oports, ch->ch_o_dtr);
869 
870 	if (!ch->ch_heldchange) {
871 		if (ch->ch_tx_busy) {
872 			ch->ch_heldtbc = ch->ch_tbc;
873 			ch->ch_tbc = 0;
874 			ch->ch_heldchange = 1;
875 		} else
876 			sbscn_loadchannelregs(ch);
877 	}
878 }
879 
880 void
881 tiocm_to_sbscn(struct sbscn_channel *ch, int how, int ttybits)
882 {
883 	u_char bits;
884 
885 	bits = 0;
886 	if (ISSET(ttybits, TIOCM_DTR))
887 		SET(bits, ch->ch_o_dtr);
888 	if (ISSET(ttybits, TIOCM_RTS))
889 		SET(bits, ch->ch_o_rts);
890 
891 	switch (how) {
892 	case TIOCMBIC:
893 		CLR(ch->ch_oports, bits);
894 		break;
895 
896 	case TIOCMBIS:
897 		SET(ch->ch_oports, bits);
898 		break;
899 
900 	case TIOCMSET:
901 		ch->ch_oports = bits;
902 		break;
903 	}
904 
905 	if (!ch->ch_heldchange) {
906 		if (ch->ch_tx_busy) {
907 			ch->ch_heldtbc = ch->ch_tbc;
908 			ch->ch_tbc = 0;
909 			ch->ch_heldchange = 1;
910 		} else
911 			sbscn_loadchannelregs(ch);
912 	}
913 }
914 
915 int
916 sbscn_to_tiocm(struct sbscn_channel *ch)
917 {
918 	u_char hwbits;
919 	int ttybits = 0;
920 
921 	hwbits = ch->ch_oports;
922 	if (ISSET(hwbits, ch->ch_o_dtr))
923 		SET(ttybits, TIOCM_DTR);
924 	if (ISSET(hwbits, ch->ch_o_rts))
925 		SET(ttybits, TIOCM_RTS);
926 
927 	hwbits = ch->ch_iports;
928 	if (ISSET(hwbits, ch->ch_i_dcd))
929 		SET(ttybits, TIOCM_CD);
930 	if (ISSET(hwbits, ch->ch_i_cts))
931 		SET(ttybits, TIOCM_CTS);
932 	if (ISSET(hwbits, ch->ch_i_dsr))
933 		SET(ttybits, TIOCM_DSR);
934 	if (ISSET(hwbits, ch->ch_i_ri))
935 		SET(ttybits, TIOCM_RI);
936 
937 	if (ch->ch_imr != 0)
938 		SET(ttybits, TIOCM_LE);
939 
940 	return (ttybits);
941 }
942 
943 static int
944 cflag2modes(tcflag_t cflag, u_char *mode1p, u_char *mode2p)
945 {
946 	u_char mode1;
947 	u_char mode2;
948 	int err = 0;
949 
950 	mode1 = mode2 = 0;
951 
952 	switch (ISSET(cflag, CSIZE)) {
953 	case CS7:
954 		mode1 |= 2;			/* XXX */
955 		break;
956 	default:
957 		err = -1;
958 		/* FALLTHRU for sanity */
959 	case CS8:
960 		mode1 |= 3;			/* XXX */
961 		break;
962 	}
963 	if (!ISSET(cflag, PARENB))
964 		mode1 |= 2 << 3;
965 	else {
966 		mode1 |= 0 << 3;
967 		if (ISSET(cflag, PARODD))
968 			mode1 |= 1 << 2;
969 	}
970 
971 	if (ISSET(cflag, CSTOPB))
972 		mode2 |= 1 << 3;		/* two stop bits XXX not std */
973 
974 	if (ISSET(cflag, CRTSCTS)) {
975 		mode1 |= 1 << 7;
976 		mode2 |= 1 << 4;
977 	}
978 
979 	*mode1p = mode1;
980 	*mode2p = mode2;
981 	return (err);
982 }
983 
984 int
985 sbscn_param(struct tty *tp, struct termios *t)
986 {
987 	struct sbscn_softc *sc = device_lookup_private(&sbscn_cd, SBSCN_UNIT(tp->t_dev));
988 	struct sbscn_channel *ch = &sc->sc_channels[SBSCN_CHAN(tp->t_dev)];
989 	long brc;
990 	u_char mode1, mode2;
991 	int s;
992 
993 /* XXX reset to console parameters if console? */
994 #if 0
995 XXX disable, enable.
996 #endif
997 
998 	/* Check requested parameters. */
999 	if (sbscn_speed(t->c_ospeed, &brc) < 0)
1000 		return (EINVAL);
1001 	if (t->c_ispeed && t->c_ispeed != t->c_ospeed)
1002 		return (EINVAL);
1003 
1004 	/*
1005 	 * For the console, always force CLOCAL and !HUPCL, so that the port
1006 	 * is always active.
1007 	 */
1008 	if (ISSET(ch->ch_swflags, TIOCFLAG_SOFTCAR) ||
1009 	    ISSET(ch->ch_hwflags, SBSCN_HW_CONSOLE)) {
1010 		SET(t->c_cflag, CLOCAL);
1011 		CLR(t->c_cflag, HUPCL);
1012 	}
1013 
1014 	/*
1015 	 * If there were no changes, don't do anything.  This avoids dropping
1016 	 * input and improves performance when all we did was frob things like
1017 	 * VMIN and VTIME.
1018 	 */
1019 	if (tp->t_ospeed == t->c_ospeed &&
1020 	    tp->t_cflag == t->c_cflag)
1021 		return (0);
1022 
1023 	if (cflag2modes(t->c_cflag, &mode1, &mode2) < 0)
1024 		return (EINVAL);
1025 
1026 	s = splserial();
1027 
1028 	ch->ch_mode1 = mode1;
1029 	ch->ch_mode2 = mode2;
1030 
1031 	/*
1032 	 * If we're not in a mode that assumes a connection is present, then
1033 	 * ignore carrier changes.
1034 	 */
1035 	if (ISSET(t->c_cflag, CLOCAL | MDMBUF))
1036 		ch->ch_i_dcd = 0;
1037 	else
1038 		ch->ch_i_dcd = ch->ch_i_dcd_pin;
1039 	/*
1040 	 * Set the flow control pins depending on the current flow control
1041 	 * mode.
1042 	 */
1043 	if (ISSET(t->c_cflag, CRTSCTS)) {
1044 		ch->ch_o_dtr = ch->ch_o_dtr_pin;
1045 		ch->ch_o_rts = ch->ch_o_rts_pin;
1046 		ch->ch_i_cts = ch->ch_i_cts_pin;
1047 		/* hw controle enable bits in mod regs set by cflag2modes */
1048 	} else if (ISSET(t->c_cflag, MDMBUF)) {
1049 		/*
1050 		 * For DTR/DCD flow control, make sure we don't toggle DTR for
1051 		 * carrier detection.
1052 		 */
1053 		ch->ch_o_dtr = 0;
1054 		ch->ch_o_rts = ch->ch_o_dtr_pin;
1055 		ch->ch_i_cts = ch->ch_i_dcd_pin;
1056 	} else {
1057 		/*
1058 		 * If no flow control, then always set RTS.  This will make
1059 		 * the other side happy if it mistakenly thinks we're doing
1060 		 * RTS/CTS flow control.
1061 		 */
1062 		ch->ch_o_dtr = ch->ch_o_dtr_pin | ch->ch_o_rts_pin;
1063 		ch->ch_o_rts = 0;
1064 		ch->ch_i_cts = 0;
1065 		if (ISSET(ch->ch_oports, ch->ch_o_dtr_pin))
1066 			SET(ch->ch_oports, ch->ch_o_rts_pin);
1067 		else
1068 			CLR(ch->ch_oports, ch->ch_o_rts_pin);
1069 	}
1070 	/* XXX maybe mask the ports which generate intrs? */
1071 
1072 	ch->ch_brc = brc;
1073 
1074 	/* XXX maybe set fifo-full receive mode if RTSCTS and high speed? */
1075 
1076 	/* And copy to tty. */
1077 	tp->t_ispeed = 0;
1078 	tp->t_ospeed = t->c_ospeed;
1079 	tp->t_cflag = t->c_cflag;
1080 
1081 	if (!ch->ch_heldchange) {
1082 		if (ch->ch_tx_busy) {
1083 			ch->ch_heldtbc = ch->ch_tbc;
1084 			ch->ch_tbc = 0;
1085 			ch->ch_heldchange = 1;
1086 		} else
1087 			sbscn_loadchannelregs(ch);
1088 	}
1089 
1090 	if (!ISSET(t->c_cflag, CHWFLOW)) {
1091 		/* Disable the high water mark. */
1092 		ch->ch_r_hiwat = 0;
1093 		ch->ch_r_lowat = 0;
1094 		if (ISSET(ch->ch_rx_flags, RX_TTY_OVERFLOWED)) {
1095 			CLR(ch->ch_rx_flags, RX_TTY_OVERFLOWED);
1096 			sbscn_schedrx(ch);
1097 		}
1098 		if (ISSET(ch->ch_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED)) {
1099 			CLR(ch->ch_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED);
1100 			sbscn_dohwiflow(ch);
1101 		}
1102 	} else {
1103 		ch->ch_r_hiwat = sbscn_rbuf_hiwat;
1104 		ch->ch_r_lowat = sbscn_rbuf_lowat;
1105 	}
1106 
1107 	splx(s);
1108 
1109 	/*
1110 	 * Update the tty layer's idea of the carrier bit, in case we changed
1111 	 * CLOCAL or MDMBUF.  We don't hang up here; we only do that by
1112 	 * explicit request.
1113 	 */
1114 	(void) (*tp->t_linesw->l_modem)(tp,
1115 	    ISSET(ch->ch_iports, ch->ch_i_dcd));
1116 
1117 #ifdef SBSCN_DEBUG
1118 	if (sbscn_debug)
1119 		sbscn_status(ch, "sbscnparam ");
1120 #endif
1121 
1122 	if (!ISSET(t->c_cflag, CHWFLOW)) {
1123 		if (ch->ch_tx_stopped) {
1124 			ch->ch_tx_stopped = 0;
1125 			sbscn_start(tp);
1126 		}
1127 	}
1128 
1129 	return (0);
1130 }
1131 
1132 void
1133 sbscn_iflush(struct sbscn_channel *ch)
1134 {
1135 #ifdef DIAGNOSTIC
1136 	int reg;
1137 #endif
1138 	int timo;
1139 
1140 #ifdef DIAGNOSTIC
1141 	reg = 0xffff;
1142 #endif
1143 	timo = 50000;
1144 	/* flush any pending I/O */
1145 	while (ISSET(READ_REG(ch->ch_base + 0x20), 0x01)
1146 	    && --timo)
1147 #ifdef DIAGNOSTIC
1148 		reg =
1149 #else
1150 		    (void)
1151 #endif
1152 		    READ_REG(ch->ch_base + 0x60);
1153 #ifdef DIAGNOSTIC
1154 	if (!timo)
1155 		aprint_debug_dev(ch->ch_sc->sc_dev,
1156 		    "sbscn_iflush timeout %02x\n", reg & 0xff);
1157 #endif
1158 }
1159 
1160 void
1161 sbscn_loadchannelregs(struct sbscn_channel *ch)
1162 {
1163 
1164 	/* XXXXX necessary? */
1165 	sbscn_iflush(ch);
1166 
1167 	WRITE_REG(ch->ch_imr_base, 0);
1168 
1169 // XXX disable?
1170 	WRITE_REG(ch->ch_base + 0x00, ch->ch_mode1);
1171 	WRITE_REG(ch->ch_base + 0x10, ch->ch_mode2);
1172 	WRITE_REG(ch->ch_base + 0x30, ch->ch_brc);
1173 
1174 	ch->ch_oports_active = ch->ch_oports;
1175 	SET_OUTPUT_SIGNALS(ch, ch->ch_oports_active);
1176 
1177 	WRITE_REG(ch->ch_imr_base, ch->ch_imr);
1178 }
1179 
1180 int
1181 sbscn_hwiflow(struct tty *tp, int block)
1182 {
1183 	struct sbscn_softc *sc = device_lookup_private(&sbscn_cd, SBSCN_UNIT(tp->t_dev));
1184 	struct sbscn_channel *ch = &sc->sc_channels[SBSCN_CHAN(tp->t_dev)];
1185 	int s;
1186 
1187 	if (ch->ch_o_rts == 0)
1188 		return (0);
1189 
1190 	s = splserial();
1191 	if (block) {
1192 		if (!ISSET(ch->ch_rx_flags, RX_TTY_BLOCKED)) {
1193 			SET(ch->ch_rx_flags, RX_TTY_BLOCKED);
1194 			sbscn_dohwiflow(ch);
1195 		}
1196 	} else {
1197 		if (ISSET(ch->ch_rx_flags, RX_TTY_OVERFLOWED)) {
1198 			CLR(ch->ch_rx_flags, RX_TTY_OVERFLOWED);
1199 			sbscn_schedrx(ch);
1200 		}
1201 		if (ISSET(ch->ch_rx_flags, RX_TTY_BLOCKED)) {
1202 			CLR(ch->ch_rx_flags, RX_TTY_BLOCKED);
1203 			sbscn_dohwiflow(ch);
1204 		}
1205 	}
1206 	splx(s);
1207 	return (1);
1208 }
1209 
1210 /*
1211  * (un)block input via hw flowcontrol
1212  */
1213 void
1214 sbscn_dohwiflow(struct sbscn_channel *ch)
1215 {
1216 
1217 	if (ch->ch_o_rts == 0)
1218 		return;
1219 
1220 	if (ISSET(ch->ch_rx_flags, RX_ANY_BLOCK)) {
1221 		CLR(ch->ch_oports, ch->ch_o_rts);
1222 		CLR(ch->ch_oports_active, ch->ch_o_rts);
1223 	} else {
1224 		SET(ch->ch_oports, ch->ch_o_rts);
1225 		SET(ch->ch_oports_active, ch->ch_o_rts);
1226 	}
1227 	SET_OUTPUT_SIGNALS(ch, ch->ch_oports_active);
1228 }
1229 
1230 void
1231 sbscn_start(struct tty *tp)
1232 {
1233 	struct sbscn_softc *sc = device_lookup_private(&sbscn_cd, SBSCN_UNIT(tp->t_dev));
1234 	struct sbscn_channel *ch = &sc->sc_channels[SBSCN_CHAN(tp->t_dev)];
1235 	int s;
1236 
1237 	s = spltty();
1238 	if (ISSET(tp->t_state, TS_BUSY | TS_TIMEOUT | TS_TTSTOP))
1239 		goto out;
1240 	if (ch->ch_tx_stopped)
1241 		goto out;
1242 	if (!ttypull(tp))
1243 		goto out;
1244 
1245 	/* Grab the first contiguous region of buffer space. */
1246 	{
1247 		u_char *tba;
1248 		int tbc;
1249 
1250 		tba = tp->t_outq.c_cf;
1251 		tbc = ndqb(&tp->t_outq, 0);
1252 
1253 		(void)splserial();
1254 
1255 		ch->ch_tba = tba;
1256 		ch->ch_tbc = tbc;
1257 	}
1258 
1259 	SET(tp->t_state, TS_BUSY);
1260 	ch->ch_tx_busy = 1;
1261 
1262 	/* Enable transmit completion interrupts if necessary. */
1263 	if (!ISSET(ch->ch_imr, 0x1)) {
1264 		SET(ch->ch_imr, 0x1);
1265 		WRITE_REG(ch->ch_imr_base, ch->ch_imr);
1266 	}
1267 
1268 	/* Output the first chunk of the contiguous buffer. */
1269 	{
1270 		u_char c;
1271 
1272 		while (ch->ch_tbc && READ_REG(ch->ch_base + 0x20) & 0x04) {
1273 			c = *ch->ch_tba++;
1274 			ch->ch_tbc--;
1275 			WRITE_REG(ch->ch_base + 0x70, c);
1276 		}
1277 	}
1278 out:
1279 	splx(s);
1280 	return;
1281 }
1282 
1283 /*
1284  * Stop output on a line.
1285  */
1286 void
1287 sbscnstop(struct tty *tp, int flag)
1288 {
1289 	struct sbscn_softc *sc = device_lookup_private(&sbscn_cd, SBSCN_UNIT(tp->t_dev));
1290 	struct sbscn_channel *ch = &sc->sc_channels[SBSCN_CHAN(tp->t_dev)];
1291 	int s;
1292 
1293 	s = splserial();
1294 	if (ISSET(tp->t_state, TS_BUSY)) {
1295 		/* Stop transmitting at the next chunk. */
1296 		ch->ch_tbc = 0;
1297 		ch->ch_heldtbc = 0;
1298 		if (!ISSET(tp->t_state, TS_TTSTOP))
1299 			SET(tp->t_state, TS_FLUSH);
1300 	}
1301 	splx(s);
1302 }
1303 
1304 void
1305 sbscn_diag(void *arg)
1306 {
1307 	struct sbscn_channel *ch = arg;
1308 	struct sbscn_softc *sc = ch->ch_sc;
1309 	int overflows, floods;
1310 	int s;
1311 
1312 	s = splserial();
1313 	overflows = ch->ch_overflows;
1314 	ch->ch_overflows = 0;
1315 	floods = ch->ch_floods;
1316 	ch->ch_floods = 0;
1317 	ch->ch_errors = 0;
1318 	splx(s);
1319 
1320 	log(LOG_WARNING, "%s: channel %d: %d fifo overflow%s, %d ibuf flood%s\n",
1321 	    device_xname(sc->sc_dev), ch->ch_num,
1322 	    overflows, overflows == 1 ? "" : "s",
1323 	    floods, floods == 1 ? "" : "s");
1324 }
1325 
1326 integrate void
1327 sbscn_rxsoft(struct sbscn_channel *ch, struct tty *tp)
1328 {
1329 	int (*rint)(int, struct tty *) = tp->t_linesw->l_rint;
1330 	u_char *get, *end;
1331 	u_int cc, scc;
1332 	u_char sr;
1333 	int code;
1334 	int s;
1335 
1336 	end = ch->ch_ebuf;
1337 	get = ch->ch_rbget;
1338 	scc = cc = sbscn_rbuf_size - ch->ch_rbavail;
1339 
1340 	if (cc == sbscn_rbuf_size) {
1341 		ch->ch_floods++;
1342 		if (ch->ch_errors++ == 0)
1343 			callout_reset(&ch->ch_diag_callout, 60 * hz,
1344 			    sbscn_diag, ch);
1345 	}
1346 
1347 	while (cc) {
1348 		code = get[0];
1349 		sr = get[1];
1350 		if (ISSET(sr, 0xf0)) {
1351 			if (ISSET(sr, 0x10)) {
1352 				ch->ch_overflows++;
1353 				if (ch->ch_errors++ == 0)
1354 					callout_reset(&ch->ch_diag_callout,
1355 					    60 * hz, sbscn_diag, ch);
1356 			}
1357 			if (ISSET(sr, 0xc0))
1358 				SET(code, TTY_FE);
1359 			if (ISSET(sr, 0x20))
1360 				SET(code, TTY_PE);
1361 		}
1362 		if ((*rint)(code, tp) == -1) {
1363 			/*
1364 			 * The line discipline's buffer is out of space.
1365 			 */
1366 			if (!ISSET(ch->ch_rx_flags, RX_TTY_BLOCKED)) {
1367 				/*
1368 				 * We're either not using flow control, or the
1369 				 * line discipline didn't tell us to block for
1370 				 * some reason.  Either way, we have no way to
1371 				 * know when there's more space available, so
1372 				 * just drop the rest of the data.
1373 				 */
1374 				get += cc << 1;
1375 				if (get >= end)
1376 					get -= sbscn_rbuf_size << 1;
1377 				cc = 0;
1378 			} else {
1379 				/*
1380 				 * Don't schedule any more receive processing
1381 				 * until the line discipline tells us there's
1382 				 * space available (through comhwiflow()).
1383 				 * Leave the rest of the data in the input
1384 				 * buffer.
1385 				 */
1386 				SET(ch->ch_rx_flags, RX_TTY_OVERFLOWED);
1387 			}
1388 			break;
1389 		}
1390 		get += 2;
1391 		if (get >= end)
1392 			get = ch->ch_rbuf;
1393 		cc--;
1394 	}
1395 
1396 	if (cc != scc) {
1397 		ch->ch_rbget = get;
1398 		s = splserial();
1399 		cc = ch->ch_rbavail += scc - cc;
1400 		/* Buffers should be ok again, release possible block. */
1401 		if (cc >= ch->ch_r_lowat) {
1402 			if (ISSET(ch->ch_rx_flags, RX_IBUF_OVERFLOWED)) {
1403 				CLR(ch->ch_rx_flags, RX_IBUF_OVERFLOWED);
1404 				SET(ch->ch_imr, 0x02);
1405 				WRITE_REG(ch->ch_imr_base, ch->ch_imr);
1406 			}
1407 			if (ISSET(ch->ch_rx_flags, RX_IBUF_BLOCKED)) {
1408 				CLR(ch->ch_rx_flags, RX_IBUF_BLOCKED);
1409 				sbscn_dohwiflow(ch);
1410 			}
1411 		}
1412 		splx(s);
1413 	}
1414 }
1415 
1416 integrate void
1417 sbscn_txsoft(struct sbscn_channel *ch, struct tty *tp)
1418 {
1419 
1420 	CLR(tp->t_state, TS_BUSY);
1421 	if (ISSET(tp->t_state, TS_FLUSH))
1422 		CLR(tp->t_state, TS_FLUSH);
1423 	else
1424 		ndflush(&tp->t_outq, (int)(ch->ch_tba - tp->t_outq.c_cf));
1425 	(*tp->t_linesw->l_start)(tp);
1426 }
1427 
1428 integrate void
1429 sbscn_stsoft(struct sbscn_channel *ch, struct tty *tp)
1430 {
1431 	u_char iports, delta;
1432 	int s;
1433 
1434 	s = splserial();
1435 	iports = ch->ch_iports;
1436 	delta = ch->ch_iports_delta;
1437 	ch->ch_iports_delta = 0;
1438 	splx(s);
1439 
1440 	if (ISSET(delta, ch->ch_i_dcd)) {
1441 		/*
1442 		 * Inform the tty layer that carrier detect changed.
1443 		 */
1444 		(void) (*tp->t_linesw->l_modem)(tp,
1445 		    ISSET(iports, ch->ch_i_dcd));
1446 	}
1447 
1448 	if (ISSET(delta, ch->ch_i_cts)) {
1449 		/* Block or unblock output according to flow control. */
1450 		if (ISSET(iports, ch->ch_i_cts)) {
1451 			ch->ch_tx_stopped = 0;
1452 			(*tp->t_linesw->l_start)(tp);
1453 		} else {
1454 			ch->ch_tx_stopped = 1;
1455 		}
1456 	}
1457 
1458 #ifdef SBSCN_DEBUG
1459 	if (sbscn_debug)
1460 		sbscn_status(ch, "sbscn_stsoft");
1461 #endif
1462 }
1463 
1464 void
1465 sbscn_soft(void *arg)
1466 {
1467 	struct sbscn_channel *ch = arg;
1468 	struct tty *tp = ch->ch_tty;
1469 
1470 	if (ch->ch_rx_ready) {
1471 		ch->ch_rx_ready = 0;
1472 		sbscn_rxsoft(ch, tp);
1473 	}
1474 
1475 	if (ch->ch_st_check) {
1476 		ch->ch_st_check = 0;
1477 		sbscn_stsoft(ch, tp);
1478 	}
1479 
1480 	if (ch->ch_tx_done) {
1481 		ch->ch_tx_done = 0;
1482 		sbscn_txsoft(ch, tp);
1483 	}
1484 }
1485 
1486 void
1487 sbscn_intr(void *arg, uint32_t status, vaddr_t pc)
1488 {
1489 	struct sbscn_channel *ch = arg;
1490 	u_char *put, *end;
1491 	u_int cc;
1492 	u_char isr, sr;
1493 
1494 	/* read ISR */
1495 	isr = READ_REG(ch->ch_isr_base) & ch->ch_imr;
1496 	if (isr == 0)
1497 		return;
1498 
1499 	end = ch->ch_ebuf;
1500 	put = ch->ch_rbput;
1501 	cc = ch->ch_rbavail;
1502 
1503 	do {
1504 		u_char	iports, delta;
1505 
1506 		if (isr & 0x02) {
1507 
1508 			sr = READ_REG(ch->ch_base + 0x20);
1509 			/* XXX sr 0x01 bit must be set at this point */
1510 
1511 #if defined(DDB) || defined(KGDB)
1512 			if ((sr & 0x80) == 0x80) {
1513 #ifdef DDB
1514 				if (ISSET(ch->ch_hwflags, SBSCN_HW_CONSOLE)) {
1515 					(void)READ_REG(ch->ch_base + 0x60);
1516 					console_debugger();
1517 					continue;
1518 				}
1519 #endif
1520 #ifdef KGDB
1521 				if (ISSET(ch->ch_hwflags, SBSCN_HW_KGDB)) {
1522 					(void)READ_REG(ch->ch_base + 0x60);
1523 					kgdb_connect(1);
1524 					continue;
1525 				}
1526 #endif
1527 			}
1528 #endif /* DDB || KGDB */
1529 
1530 		    	if (!ISSET(ch->ch_rx_flags, RX_IBUF_OVERFLOWED)) {
1531 				while (cc > 0) {
1532 					put[0] = READ_REG(ch->ch_base + 0x60);
1533 					put[1] = sr;
1534 					put += 2;
1535 					if (put >= end)
1536 						put = ch->ch_rbuf;
1537 					cc--;
1538 
1539 					sr = READ_REG(ch->ch_base + 0x20);
1540 					if (!ISSET(sr, 0x02))
1541 						break;
1542 				}
1543 
1544 				/*
1545 				 * Current string of incoming characters ended
1546 				 * because no more data was available or we
1547 				 * ran out of space.  Schedule a receive event
1548 				 * if any data was received.  If we're out of
1549 				 * space, turn off receive interrupts.
1550 				 */
1551 				ch->ch_rbput = put;
1552 				ch->ch_rbavail = cc;
1553 				if (!ISSET(ch->ch_rx_flags, RX_TTY_OVERFLOWED))
1554 					ch->ch_rx_ready = 1;
1555 
1556 				/*
1557 				 * See if we are in danger of overflowing a
1558 				 * buffer. If so, use hardware flow control
1559 				 * to ease the pressure.
1560 				 */
1561 				if (!ISSET(ch->ch_rx_flags, RX_IBUF_BLOCKED) &&
1562 				    cc < ch->ch_r_hiwat) {
1563 					SET(ch->ch_rx_flags, RX_IBUF_BLOCKED);
1564 					sbscn_dohwiflow(ch);
1565 				}
1566 
1567 				/*
1568 				 * If we're out of space, disable receive
1569 				 * interrupts until the queue has drained
1570 				 * a bit.
1571 				 */
1572 				if (!cc) {
1573 					SET(ch->ch_rx_flags,
1574 					    RX_IBUF_OVERFLOWED);
1575 					CLR(ch->ch_imr, 0x02);
1576 					WRITE_REG(ch->ch_imr_base, ch->ch_imr);
1577 				}
1578 			} else {
1579 				/* XXX panic? */
1580 				CLR(ch->ch_imr, 0x02);
1581 				WRITE_REG(ch->ch_imr_base, ch->ch_imr);
1582 				continue;
1583 			}
1584 		}
1585 
1586 		if (isr & 0x01) {
1587 			CLR(ch->ch_imr, 0x01);
1588 			WRITE_REG(ch->ch_imr_base, ch->ch_imr);
1589 		}
1590 
1591 #if 0
1592 XXX
1593 		if (isr & 0x08) {
1594 			clear input signal change!
1595 		}
1596 #endif
1597 		iports = GET_INPUT_SIGNALS(ch);
1598 		delta = iports ^ ch->ch_iports;
1599 		ch->ch_iports = iports;
1600 
1601 		/*
1602 		 * Process normal status changes
1603 		 */
1604 		if (ISSET(delta, ch->ch_i_mask)) {
1605 			SET(ch->ch_iports_delta, delta);
1606 
1607 			/*
1608 			 * Stop output immediately if we lose the output
1609 			 * flow control signal or carrier detect.
1610 			 */
1611 			if (ISSET(~iports, ch->ch_i_mask)) {
1612 				ch->ch_tbc = 0;
1613 				ch->ch_heldtbc = 0;
1614 #ifdef SBSCN_DEBUG
1615 				if (sbscn_debug)
1616 					sbscn_status(ch, "sbscn_intr  ");
1617 #endif
1618 			}
1619 
1620 			ch->ch_st_check = 1;
1621 		}
1622 	} while ((isr = (READ_REG(ch->ch_isr_base) & ch->ch_imr)) != 0);
1623 
1624 	/*
1625 	 * Done handling any receive interrupts and status changes, and
1626 	 * clearing the tx-ready interrupt if it was set.  See if data can
1627 	 * be transmitted as well. Schedule tx done event if no data left
1628 	 * and tty was marked busy.
1629 	 */
1630 	sr = READ_REG(ch->ch_base + 0x20);
1631 	if (ISSET(sr, 0x4)) {
1632 
1633 		/*
1634 		 * If we've delayed a parameter change, do it now, and restart
1635 		 * output.
1636 		 */
1637 		if (ch->ch_heldchange) {
1638 			sbscn_loadchannelregs(ch);
1639 			ch->ch_heldchange = 0;
1640 			ch->ch_tbc = ch->ch_heldtbc;
1641 			ch->ch_heldtbc = 0;
1642 		}
1643 
1644 		/* Output the next chunk of the contiguous buffer, if any. */
1645 		if (ch->ch_tbc > 0) {
1646 			int wrote1;
1647 			u_char c;
1648 
1649 			wrote1 = 0;
1650 			while (ch->ch_tbc &&
1651 			    READ_REG(ch->ch_base + 0x20) & 0x04) {
1652 				wrote1 = 1;
1653 				c = *ch->ch_tba++;
1654 				ch->ch_tbc--;
1655 				WRITE_REG(ch->ch_base + 0x70, c);
1656 			}
1657 			if (wrote1) {
1658 				SET(ch->ch_imr, 0x01);
1659 				WRITE_REG(ch->ch_imr_base, ch->ch_imr);
1660 			}
1661 		} else {
1662 			/*
1663 			 * transmit completion interrupts already disabled,
1664 			 * mark the channel tx state as done.
1665 			 */
1666 			if (ch->ch_tx_busy) {
1667 				ch->ch_tx_busy = 0;
1668 				ch->ch_tx_done = 1;
1669 			}
1670 		}
1671 	}
1672 
1673 	/* Wake up the poller. */
1674 	softint_schedule(ch->ch_si);
1675 
1676 #ifdef RND_SBSCN
1677 	rnd_add_uint32(&ch->ch_rnd_source, isr | sr);
1678 #endif
1679 }
1680 
1681 /*
1682  * The following functions are polled getc and putc routines, shared
1683  * by the console and kgdb glue.
1684  */
1685 
1686 int
1687 sbscn_common_getc(u_long addr, int chan)
1688 {
1689 	int s = splhigh();
1690 	u_long base = MIPS_PHYS_TO_KSEG1(addr + (chan * 0x100));
1691 	int c;
1692 
1693 	/* block until a character becomes available */
1694 	while ((READ_REG(base + 0x20) & 0x01) == 0)
1695 		continue;
1696 
1697 	c = READ_REG(base + 0x60) & 0xff;
1698 	splx(s);
1699 	return (c);
1700 }
1701 
1702 void
1703 sbscn_common_putc(u_long addr, int chan, int c)
1704 {
1705 	int s = splhigh();
1706 	int timo;
1707 	u_long base = MIPS_PHYS_TO_KSEG1(addr + (chan * 0x100));
1708 
1709 	/* wait for any pending transmission to finish */
1710 	timo = 1500000;
1711 	while ((READ_REG(base + 0x20) & 0x08) == 0 && --timo)
1712 		continue;
1713 
1714 	WRITE_REG(base + 0x70, c);
1715 
1716 	/* wait for this transmission to complete */
1717 	timo = 15000000;
1718 	while ((READ_REG(base + 0x20) & 0x08) == 0 && --timo)
1719 		continue;
1720 
1721 	splx(s);
1722 }
1723 
1724 /*
1725  * Initialize UART for use as console or KGDB line.
1726  */
1727 int
1728 sbscn_init(u_long addr, int chan, int rate, tcflag_t cflag)
1729 {
1730 #if 1
1731 	u_long chanregbase = MIPS_PHYS_TO_KSEG1(addr + (chan * 0x100));
1732 	u_long imaskreg = MIPS_PHYS_TO_KSEG1(addr + 0x230 + (chan * 0x20));
1733 	u_char mode1, mode2;
1734 	u_long brc;
1735 	volatile int timo;
1736 
1737 	WRITE_REG(imaskreg, 0);			/* disable channel intrs */
1738 
1739 	/* XXX should we really do the following?  how about only if enabled? */
1740 	/* wait for any pending transmission to finish */
1741 	timo = 1500000;
1742 	while ((READ_REG(chanregbase + 0x20) & 0x08) == 0 && --timo)
1743 		continue;
1744 
1745 	/* XXX: wait a little.  THIS SHOULD NOT BE NECESSARY!!! (?) */
1746 	timo = 1500000;
1747 	while (--timo)
1748 		;
1749 
1750 	WRITE_REG(chanregbase + 0x50, 2 << 4);	/* reset receiver */
1751 	WRITE_REG(chanregbase + 0x50, 3 << 4);	/* reset transmitter */
1752 
1753 	/* set up the line for use */
1754 	(void)cflag2modes(cflag, &mode1, &mode2);
1755 	(void)sbscn_speed(rate, &brc);
1756 	WRITE_REG(chanregbase + 0x00, mode1);
1757 	WRITE_REG(chanregbase + 0x10, mode2);
1758 	WRITE_REG(chanregbase + 0x30, brc);
1759 
1760 	/* enable transmit and receive */
1761 #define	M_DUART_RX_EN			0x01
1762 #define	M_DUART_TX_EN			0x04
1763 	WRITE_REG(chanregbase + 0x50,M_DUART_RX_EN | M_DUART_TX_EN);
1764 #endif
1765 
1766 	/* XXX: wait a little.  THIS SHOULD NOT BE NECESSARY!!! (?) */
1767 	timo = 1500000;
1768 	while (--timo)
1769 		;
1770 
1771 #if 0 /* XXXCGD */
1772 	bus_space_handle_t ioh;
1773 
1774 	if (bus_space_map(iot, iobase, COM_NPORTS, 0, &ioh))
1775 		return (ENOMEM); /* ??? */
1776 
1777 	bus_space_write_1(iot, ioh, com_lcr, LCR_EERS);
1778 	bus_space_write_1(iot, ioh, com_efr, 0);
1779 	bus_space_write_1(iot, ioh, com_lcr, LCR_DLAB);
1780 	rate = comspeed(rate, frequency);
1781 	bus_space_write_1(iot, ioh, com_dlbl, rate);
1782 	bus_space_write_1(iot, ioh, com_dlbh, rate >> 8);
1783 	bus_space_write_1(iot, ioh, com_lcr, cflag2lcr(cflag));
1784 	bus_space_write_1(iot, ioh, com_mcr, MCR_DTR | MCR_RTS);
1785 	bus_space_write_1(iot, ioh, com_fifo,
1786 	    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_1);
1787 	bus_space_write_1(iot, ioh, com_ier, 0);
1788 
1789 	*iohp = ioh;
1790 	return (0);
1791 #endif /* XXXCGD */
1792 	/* XXXCGD */
1793 	return (0);
1794 }
1795 
1796 /*
1797  * Following are all routines needed for sbscn to act as console
1798  */
1799 int
1800 sbscn_cnattach(u_long addr, int chan, int rate, tcflag_t cflag)
1801 {
1802 	int res;
1803 	static struct consdev sbscn_cons = {
1804 		NULL, NULL, sbscn_cngetc, sbscn_cnputc, sbscn_cnpollc, NULL,
1805 		    NULL, NULL, NODEV, CN_NORMAL
1806 	};
1807 
1808 	res = sbscn_init(addr, chan, rate, cflag);
1809 	if (res)
1810 		return (res);
1811 
1812 	cn_tab = &sbscn_cons;
1813 
1814 	sbscn_cons_present = 1;
1815 	sbscn_cons_addr = addr;
1816 	sbscn_cons_chan = chan;
1817 	sbscn_cons_rate = rate;
1818 	sbscn_cons_cflag = cflag;
1819 
1820 	return (0);
1821 }
1822 
1823 int
1824 sbscn_cngetc(dev_t dev)
1825 {
1826 
1827 	return (sbscn_common_getc(sbscn_cons_addr, sbscn_cons_chan));
1828 }
1829 
1830 /*
1831  * Console kernel output character routine.
1832  */
1833 void
1834 sbscn_cnputc(dev_t dev, int c)
1835 {
1836 
1837 	sbscn_common_putc(sbscn_cons_addr, sbscn_cons_chan, c);
1838 }
1839 
1840 void
1841 sbscn_cnpollc(dev_t dev, int on)
1842 {
1843 
1844 }
1845 
1846 #ifdef KGDB
1847 int
1848 sbscn_kgdb_attach(u_long addr, int chan, int rate, tcflag_t cflag)
1849 {
1850 	int res;
1851 
1852 	if (!sbscn_cons_present &&
1853 	    sbscn_cons_addr == addr && sbscn_cons_chan == chan)
1854 		return (EBUSY); /* cannot share with console */
1855 
1856 	res = sbscn_init(addr, chan, rate, cflag);
1857 	if (res)
1858 		return (res);
1859 
1860 	kgdb_attach(sbscn_kgdb_getc, sbscn_kgdb_putc, NULL);
1861 	kgdb_dev = 123; /* unneeded, only to satisfy some tests */
1862 
1863 	sbscn_kgdb_present = 1;
1864 	sbscn_kgdb_addr = addr;
1865 	sbscn_kgdb_chan = chan;
1866 
1867 	return (0);
1868 }
1869 
1870 /* ARGSUSED */
1871 int
1872 sbscn_kgdb_getc(void *arg)
1873 {
1874 
1875 	return (sbscn_common_getc(sbscn_kgdb_addr, sbscn_kgdb_chan));
1876 }
1877 
1878 /* ARGSUSED */
1879 void
1880 sbscn_kgdb_putc(void *arg, int c)
1881 {
1882 
1883 	sbscn_common_getc(sbscn_kgdb_addr, sbscn_kgdb_chan, c);
1884 }
1885 #endif /* KGDB */
1886 
1887 /*
1888  * helper function to identify the sbscn channels used by
1889  * console or KGDB (and not yet autoconf attached)
1890  */
1891 int
1892 sbscn_is_console(u_long addr, int chan)
1893 {
1894 
1895 	if (sbscn_cons_present && !sbscn_cons_attached &&
1896 	    sbscn_cons_addr == addr && sbscn_cons_chan == chan)
1897 		return (1);
1898 #ifdef KGDB
1899 	if (sbscn_kgdb_present && !sbscn_kgdb_attached &&
1900 	    sbscn_kgdb_addr == addr && sbscn_kgdb_chan == chan)
1901 		return (1);
1902 #endif
1903 	return (0);
1904 }
1905