xref: /netbsd-src/sys/arch/arm/sa11x0/sa11x0_com.c (revision 09afef20633f5fe63d92dfe43ee3a9380dc06883)
1 /*      $NetBSD: sa11x0_com.c,v 1.45 2009/05/29 14:15:44 rjs Exp $        */
2 
3 /*-
4  * Copyright (c) 1998, 1999, 2001 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by IWAMOTO Toshihiro.
9  *
10  * This code is derived from software contributed to The NetBSD Foundation
11  * by Charles M. Hannum.
12  *
13  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  * 1. Redistributions of source code must retain the above copyright
17  *    notice, this list of conditions and the following disclaimer.
18  * 2. Redistributions in binary form must reproduce the above copyright
19  *    notice, this list of conditions and the following disclaimer in the
20  *    documentation and/or other materials provided with the distribution.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
23  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
24  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
25  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
26  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
27  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
28  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
29  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
30  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
31  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
32  * POSSIBILITY OF SUCH DAMAGE.
33  */
34 
35 /*
36  * Copyright (c) 1991 The Regents of the University of California.
37  * All rights reserved.
38  *
39  * Redistribution and use in source and binary forms, with or without
40  * modification, are permitted provided that the following conditions
41  * are met:
42  * 1. Redistributions of source code must retain the above copyright
43  *    notice, this list of conditions and the following disclaimer.
44  * 2. Redistributions in binary form must reproduce the above copyright
45  *    notice, this list of conditions and the following disclaimer in the
46  *    documentation and/or other materials provided with the distribution.
47  * 3. Neither the name of the University nor the names of its contributors
48  *    may be used to endorse or promote products derived from this software
49  *    without specific prior written permission.
50  *
51  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
52  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
53  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
54  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
55  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
56  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
57  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
58  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
59  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
60  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
61  * SUCH DAMAGE.
62  *
63  *	@(#)com.c	7.5 (Berkeley) 5/16/91
64  */
65 
66 #include <sys/cdefs.h>
67 __KERNEL_RCSID(0, "$NetBSD: sa11x0_com.c,v 1.45 2009/05/29 14:15:44 rjs Exp $");
68 
69 #include "opt_com.h"
70 #include "opt_ddb.h"
71 #include "opt_ddbparam.h"
72 #include "opt_kgdb.h"
73 #include "opt_multiprocessor.h"
74 #include "opt_lockdebug.h"
75 
76 #include "rnd.h"
77 #if NRND > 0 && defined(RND_COM)
78 #include <sys/rnd.h>
79 #endif
80 
81 #include <sys/param.h>
82 #include <sys/systm.h>
83 #include <sys/types.h>
84 #include <sys/conf.h>
85 #include <sys/file.h>
86 #include <sys/device.h>
87 #include <sys/kernel.h>
88 #include <sys/malloc.h>
89 #include <sys/tty.h>
90 #include <sys/uio.h>
91 #include <sys/vnode.h>
92 #include <sys/kauth.h>
93 
94 #include <dev/cons.h>
95 
96 #include <machine/bus.h>
97 #include <arm/sa11x0/sa11x0_reg.h>
98 #include <arm/sa11x0/sa11x0_var.h>
99 #include <arm/sa11x0/sa11x0_comreg.h>
100 #include <arm/sa11x0/sa11x0_comvar.h>
101 #include <arm/sa11x0/sa11x0_gpioreg.h>
102 
103 #ifdef hpcarm
104 #include <hpc/include/platid.h>
105 #include <hpc/include/platid_mask.h>
106 #endif
107 
108 #include "sacom.h"
109 
110 dev_type_open(sacomopen);
111 dev_type_close(sacomclose);
112 dev_type_read(sacomread);
113 dev_type_write(sacomwrite);
114 dev_type_ioctl(sacomioctl);
115 dev_type_stop(sacomstop);
116 dev_type_tty(sacomtty);
117 dev_type_poll(sacompoll);
118 
119 const struct cdevsw sacom_cdevsw = {
120 	sacomopen, sacomclose, sacomread, sacomwrite, sacomioctl,
121 	sacomstop, sacomtty, sacompoll, nommap, ttykqfilter, D_TTY
122 };
123 
124 static	int	sacom_match(device_t, cfdata_t, void *);
125 static	void	sacom_attach(device_t, device_t, void *);
126 static	void	sacom_filltx(struct sacom_softc *);
127 static	void	sacom_attach_subr(struct sacom_softc *);
128 #if defined(DDB) || defined(KGDB)
129 static	void	sacom_enable_debugport(struct sacom_softc *);
130 #endif
131 int		sacom_detach(device_t, int);
132 void		sacom_config(struct sacom_softc *);
133 int		sacom_activate(device_t, enum devact);
134 void		sacom_shutdown(struct sacom_softc *);
135 static	u_int	cflag2cr0(tcflag_t);
136 int		sacomparam(struct tty *, struct termios *);
137 void		sacomstart(struct tty *);
138 int		sacomhwiflow(struct tty *, int);
139 
140 void		sacom_loadchannelregs(struct sacom_softc *);
141 void		sacom_hwiflow(struct sacom_softc *);
142 void		sacom_break(struct sacom_softc *, int);
143 void		sacom_modem(struct sacom_softc *, int);
144 void		tiocm_to_sacom(struct sacom_softc *, u_long, int);
145 int		sacom_to_tiocm(struct sacom_softc *);
146 void		sacom_iflush(struct sacom_softc *);
147 
148 int		sacominit(bus_space_tag_t, bus_addr_t, int, tcflag_t,
149 			  bus_space_handle_t *);
150 int		sacom_is_console(bus_space_tag_t, bus_addr_t,
151 				 bus_space_handle_t *);
152 
153 void 		sacomsoft(void *);
154 
155 static inline void sacom_rxsoft(struct sacom_softc *, struct tty *);
156 static inline void sacom_txsoft(struct sacom_softc *, struct tty *);
157 static inline void sacom_stsoft(struct sacom_softc *, struct tty *);
158 static inline void sacom_schedrx(struct sacom_softc *);
159 
160 #ifdef hpcarm
161 /* HPCARM specific functions */
162 static void	sacom_j720_init(struct sa11x0_softc *, struct sacom_softc *);
163 #endif
164 
165 #define COMUNIT_MASK	0x7ffff
166 #define COMDIALOUT_MASK	0x80000
167 
168 #define COMUNIT(x)	(minor(x) & COMUNIT_MASK)
169 #define COMDIALOUT(x)	(minor(x) & COMDIALOUT_MASK)
170 
171 #define COM_ISALIVE(sc)	((sc)->enabled != 0 && \
172 			 device_is_active((sc)->sc_dev))
173 
174 #define COM_BARRIER(t, h, f) bus_space_barrier((t), (h), 0, COM_NPORTS, (f))
175 #define COM_LOCK(sc)
176 #define COM_UNLOCK(sc)
177 
178 int		sacomintr(void *);
179 int		sacomcngetc(dev_t);
180 void		sacomcnputc(dev_t, int);
181 void		sacomcnpollc(dev_t, int);
182 
183 void		sacomcnprobe(struct consdev *);
184 void		sacomcninit(struct consdev *);
185 
186 extern struct bus_space sa11x0_bs_tag;
187 
188 static bus_space_tag_t sacomconstag;
189 static bus_space_handle_t sacomconsioh;
190 static bus_addr_t sacomconsaddr = SACOM3_BASE; /* XXX */
191 
192 static int sacomconsattached;
193 static int sacomconsrate;
194 static tcflag_t sacomconscflag;
195 
196 CFATTACH_DECL_NEW(sacom, sizeof(struct sacom_softc),
197     sacom_match, sacom_attach, NULL, NULL);
198 extern struct cfdriver sacom_cd;
199 
200 #ifdef hpcarm
201 struct platid_data sacom_platid_table[] = {
202 	{ &platid_mask_MACH_HP_JORNADA_7XX, sacom_j720_init },
203 	{ NULL, NULL }
204 };
205 #endif
206 
207 struct consdev sacomcons = {
208 	NULL, NULL, sacomcngetc, sacomcnputc, sacomcnpollc, NULL,
209 	NULL, NULL, NODEV, CN_NORMAL
210 };
211 
212 #ifndef CONMODE
213 #define CONMODE ((TTYDEF_CFLAG & ~(CSIZE | CSTOPB | PARENB)) | CS8) /* 8N1 */
214 #endif
215 #ifndef CONSPEED
216 #define CONSPEED 9600
217 #endif
218 #ifndef CONADDR
219 #define CONADDR SACOM3_BASE
220 #endif
221 
222 static int
223 sacom_match(device_t parent, cfdata_t match, void *aux)
224 {
225 
226 	return 1;
227 }
228 
229 void
230 sacom_attach(device_t parent, device_t self, void *aux)
231 {
232 	struct sacom_softc *sc = device_private(self);
233 	struct sa11x0_attach_args *sa = aux;
234 
235 #ifdef hpcarm
236 	struct platid_data *p;
237 	void (*mdinit)(device_t, struct sacom_softc *);
238 #endif
239 
240 	aprint_normal("\n");
241 
242 	sc->sc_dev = self;
243 	sc->sc_iot = sa->sa_iot;
244 	sc->sc_baseaddr = sa->sa_addr;
245 
246 	if (bus_space_map(sa->sa_iot, sa->sa_addr, sa->sa_size, 0,
247 	    &sc->sc_ioh)) {
248 		aprint_normal_dev(self, "unable to map registers\n");
249 		return;
250 	}
251 
252 	switch (sc->sc_baseaddr) {
253 	case SACOM1_BASE:
254 		aprint_normal_dev(self, "SA-11x0 UART1\n");
255 		break;
256 	case SACOM2_BASE:
257 		aprint_normal_dev(self, "SA-11x0 UART2 (IRDA)\n");
258 		break;
259 	case SACOM3_BASE:
260 		aprint_normal_dev(self, "SA-11x0 UART3\n");
261 		break;
262 	default:
263 		aprint_normal_dev(self, "unknown SA-11x0 UART\n");
264 		break;
265 	}
266 
267 	sacom_attach_subr(sc);
268 
269 #ifdef hpcarm
270 	/* Do hpcarm specific initialization, if any */
271 	if ((p = platid_search_data(&platid, sacom_platid_table)) != NULL) {
272 		mdinit = p->data;
273 		(mdinit)(parent, sc);
274 	}
275 #endif
276 
277 	sa11x0_intr_establish(0, sa->sa_intr, 1, IPL_SERIAL, sacomintr, sc);
278 }
279 
280 void
281 sacom_attach_subr(struct sacom_softc *sc)
282 {
283 	bus_addr_t iobase = sc->sc_baseaddr;
284 	bus_space_tag_t iot = sc->sc_iot;
285 	struct tty *tp;
286 
287 	/* XXX Do we need to disable interrupts here? */
288 
289 	if (iot == sacomconstag && iobase == sacomconsaddr) {
290 		sacomconsattached = 1;
291 		sc->sc_speed = SACOMSPEED(sacomconsrate);
292 
293 		/* Make sure the console is always "hardwired". */
294 		delay(10000);			/* wait for output to finish */
295 		SET(sc->sc_hwflags, COM_HW_CONSOLE);
296 		SET(sc->sc_swflags, TIOCFLAG_SOFTCAR);
297 	}
298 
299 	tp = ttymalloc();
300 	tp->t_oproc = sacomstart;
301 	tp->t_param = sacomparam;
302 	tp->t_hwiflow = sacomhwiflow;
303 
304 	sc->sc_tty = tp;
305 	sc->sc_rbuf = malloc(SACOM_RING_SIZE << 1, M_DEVBUF, M_NOWAIT);
306 	sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
307 	sc->sc_rbavail = SACOM_RING_SIZE;
308 	if (sc->sc_rbuf == NULL) {
309 		aprint_normal_dev(sc->sc_dev, "unable to allocate ring buffer\n");
310 		return;
311 	}
312 	sc->sc_ebuf = sc->sc_rbuf + (SACOM_RING_SIZE << 1);
313 	sc->sc_tbc = 0;
314 
315 	tty_attach(tp);
316 
317 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
318 		int maj;
319 
320 		/* locate the major number */
321 		maj = cdevsw_lookup_major(&sacom_cdevsw);
322 
323 		cn_tab->cn_dev = makedev(maj, device_unit(sc->sc_dev));
324 
325 		delay(10000); /* XXX */
326 		aprint_normal_dev(sc->sc_dev, "console\n");
327 		delay(10000); /* XXX */
328 	}
329 
330 
331 	sc->sc_si = softint_establish(SOFTINT_SERIAL, sacomsoft, sc);
332 
333 #if NRND > 0 && defined(RND_COM)
334 	rnd_attach_source(&sc->rnd_source, device_xname(sc->sc_dev),
335 			  RND_TYPE_TTY, 0);
336 #endif
337 
338 	/* if there are no enable/disable functions, assume the device
339 	   is always enabled */
340 	if (!sc->enable)
341 		sc->enabled = 1;
342 
343 	sacom_config(sc);
344 
345 	SET(sc->sc_hwflags, COM_HW_DEV_OK);
346 }
347 
348 /* This is necessary when dynamically changing SAIP configuration. */
349 int
350 sacom_detach(device_t dev, int flags)
351 {
352 	struct sacom_softc *sc = device_private(dev);
353 	int maj, mn;
354 
355 	/* locate the major number */
356 	maj = cdevsw_lookup_major(&sacom_cdevsw);
357 
358 	/* Nuke the vnodes for any open instances. */
359 	mn = device_unit(dev);
360 	vdevgone(maj, mn, mn, VCHR);
361 
362 	mn |= COMDIALOUT_MASK;
363 	vdevgone(maj, mn, mn, VCHR);
364 
365 	/* Free the receive buffer. */
366 	free(sc->sc_rbuf, M_DEVBUF);
367 
368 	/* Detach and free the tty. */
369 	tty_detach(sc->sc_tty);
370 	ttyfree(sc->sc_tty);
371 
372 	/* Unhook the soft interrupt handler. */
373 	softint_disestablish(sc->sc_si);
374 
375 #if NRND > 0 && defined(RND_COM)
376 	/* Unhook the entropy source. */
377 	rnd_detach_source(&sc->rnd_source);
378 #endif
379 
380 	return 0;
381 }
382 
383 void
384 sacom_config(struct sacom_softc *sc)
385 {
386 	bus_space_tag_t iot = sc->sc_iot;
387 	bus_space_handle_t ioh = sc->sc_ioh;
388 
389 	/* Disable engine before configuring the device. */
390 	sc->sc_cr3 = 0;
391 	bus_space_write_4(iot, ioh, SACOM_CR3, sc->sc_cr3);
392 
393 #ifdef DDB
394 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE))
395 		sacom_enable_debugport(sc);
396 #endif
397 }
398 
399 #ifdef DDB
400 static void
401 sacom_enable_debugport(struct sacom_softc *sc)
402 {
403 	bus_space_tag_t iot = sc->sc_iot;
404 	bus_space_handle_t ioh = sc->sc_ioh;
405 	int s;
406 
407 	s = splserial();
408 	COM_LOCK(sc);
409 	sc->sc_cr3 = CR3_RXE | CR3_TXE;
410 	bus_space_write_4(iot, ioh, SACOM_CR3, sc->sc_cr3);
411 	COM_UNLOCK(sc);
412 	splx(s);
413 }
414 #endif
415 
416 int
417 sacom_activate(device_t dev, enum devact act)
418 {
419 	struct sacom_softc *sc = device_private(dev);
420 	int s, rv = 0;
421 
422 	s = splserial();
423 	COM_LOCK(sc);
424 	switch (act) {
425 	case DVACT_ACTIVATE:
426 		rv = EOPNOTSUPP;
427 		break;
428 
429 	case DVACT_DEACTIVATE:
430 		if (sc->sc_hwflags & (COM_HW_CONSOLE|COM_HW_KGDB)) {
431 			rv = EBUSY;
432 			break;
433 		}
434 
435 		if (sc->disable != NULL && sc->enabled != 0) {
436 			(*sc->disable)(sc);
437 			sc->enabled = 0;
438 		}
439 		break;
440 	}
441 
442 	COM_UNLOCK(sc);
443 	splx(s);
444 	return rv;
445 }
446 
447 void
448 sacom_shutdown(struct sacom_softc *sc)
449 {
450 	struct tty *tp = sc->sc_tty;
451 	int s;
452 
453 	s = splserial();
454 	COM_LOCK(sc);
455 
456 	/* Clear any break condition set with TIOCSBRK. */
457 	sacom_break(sc, 0);
458 
459 	/*
460 	 * Hang up if necessary.  Wait a bit, so the other side has time to
461 	 * notice even if we immediately open the port again.
462 	 * Avoid tsleeping above splhigh().
463 	 */
464 	if (ISSET(tp->t_cflag, HUPCL)) {
465 		sacom_modem(sc, 0);
466 		COM_UNLOCK(sc);
467 		splx(s);
468 		/* XXX tsleep will only timeout */
469 		(void) tsleep(sc, TTIPRI, ttclos, hz);
470 		s = splserial();
471 		COM_LOCK(sc);
472 	}
473 
474 	/* Turn off interrupts. */
475 	sc->sc_cr3 = 0;
476 	bus_space_write_4(sc->sc_iot, sc->sc_ioh, SACOM_CR3, sc->sc_cr3);
477 
478 	if (sc->disable) {
479 #ifdef DIAGNOSTIC
480 		if (!sc->enabled)
481 			panic("sacom_shutdown: not enabled?");
482 #endif
483 		(*sc->disable)(sc);
484 		sc->enabled = 0;
485 	}
486 	COM_UNLOCK(sc);
487 	splx(s);
488 }
489 
490 int
491 sacomopen(dev_t dev, int flag, int mode, struct lwp *l)
492 {
493 	struct sacom_softc *sc;
494 	struct tty *tp;
495 	int s, s2;
496 	int error;
497 
498 	sc = device_lookup_private(&sacom_cd, COMUNIT(dev));
499 	if (sc == NULL || !ISSET(sc->sc_hwflags, COM_HW_DEV_OK) ||
500 		sc->sc_rbuf == NULL)
501 		return ENXIO;
502 
503 	if (!device_is_active(sc->sc_dev))
504 		return ENXIO;
505 
506 	tp = sc->sc_tty;
507 
508 	if (kauth_authorize_device_tty(l->l_cred, KAUTH_DEVICE_TTY_OPEN, tp))
509 		return (EBUSY);
510 
511 	s = spltty();
512 
513 	/*
514 	 * Do the following iff this is a first open.
515 	 */
516 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
517 		struct termios t;
518 
519 		tp->t_dev = dev;
520 
521 		s2 = splserial();
522 		COM_LOCK(sc);
523 
524 		if (sc->enable) {
525 			if ((*sc->enable)(sc)) {
526 				COM_UNLOCK(sc);
527 				splx(s2);
528 				splx(s);
529 				aprint_normal_dev(sc->sc_dev, "device enable failed\n");
530 				return EIO;
531 			}
532 			sc->enabled = 1;
533 			sacom_config(sc);
534 		}
535 
536 		/* Turn on interrupts. */
537 		sc->sc_cr3 = CR3_RXE | CR3_TXE | CR3_RIE | CR3_TIE;
538 		bus_space_write_4(sc->sc_iot, sc->sc_ioh, SACOM_CR3,
539 				  sc->sc_cr3);
540 
541 
542 		COM_UNLOCK(sc);
543 		splx(s2);
544 
545 		/*
546 		 * Initialize the termios status to the defaults.  Add in the
547 		 * sticky bits from TIOCSFLAGS.
548 		 */
549 		t.c_ispeed = 0;
550 		if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
551 			t.c_ospeed = sacomconsrate;
552 			t.c_cflag = sacomconscflag;
553 		} else {
554 			t.c_ospeed = TTYDEF_SPEED;
555 			t.c_cflag = TTYDEF_CFLAG;
556 		}
557 		if (ISSET(sc->sc_swflags, TIOCFLAG_CLOCAL))
558 			SET(t.c_cflag, CLOCAL);
559 		if (ISSET(sc->sc_swflags, TIOCFLAG_CRTSCTS))
560 			SET(t.c_cflag, CRTSCTS);
561 		if (ISSET(sc->sc_swflags, TIOCFLAG_MDMBUF))
562 			SET(t.c_cflag, MDMBUF);
563 		/* Make sure sacomparam() will do something. */
564 		tp->t_ospeed = 0;
565 		(void) sacomparam(tp, &t);
566 		tp->t_iflag = TTYDEF_IFLAG;
567 		tp->t_oflag = TTYDEF_OFLAG;
568 		tp->t_lflag = TTYDEF_LFLAG;
569 		ttychars(tp);
570 		ttsetwater(tp);
571 
572 		s2 = splserial();
573 		COM_LOCK(sc);
574 
575 		/*
576 		 * Turn on DTR.  We must always do this, even if carrier is not
577 		 * present, because otherwise we'd have to use TIOCSDTR
578 		 * immediately after setting CLOCAL, which applications do not
579 		 * expect.  We always assert DTR while the device is open
580 		 * unless explicitly requested to deassert it.
581 		 */
582 		sacom_modem(sc, 1);
583 
584 		/* Clear the input ring, and unblock. */
585 		sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
586 		sc->sc_rbavail = SACOM_RING_SIZE;
587 		sacom_iflush(sc);
588 		CLR(sc->sc_rx_flags, RX_ANY_BLOCK);
589 		sacom_hwiflow(sc);
590 
591 #ifdef COM_DEBUG
592 		if (sacom_debug)
593 			comstatus(sc, "sacomopen  ");
594 #endif
595 
596 		COM_UNLOCK(sc);
597 		splx(s2);
598 	}
599 
600 	splx(s);
601 
602 	error = ttyopen(tp, COMDIALOUT(dev), ISSET(flag, O_NONBLOCK));
603 	if (error)
604 		goto bad;
605 
606 	error = (*tp->t_linesw->l_open)(dev, tp);
607 	if (error)
608 		goto bad;
609 
610 	return 0;
611 
612 bad:
613 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
614 		/*
615 		 * We failed to open the device, and nobody else had it opened.
616 		 * Clean up the state as appropriate.
617 		 */
618 		sacom_shutdown(sc);
619 	}
620 
621 	return error;
622 }
623 
624 int
625 sacomclose(dev_t dev, int flag, int mode, struct lwp *l)
626 {
627 	struct sacom_softc *sc =
628 		device_lookup_private(&sacom_cd, COMUNIT(dev));
629 	struct tty *tp = sc->sc_tty;
630 
631 	/* XXX This is for cons.c. */
632 	if (!ISSET(tp->t_state, TS_ISOPEN))
633 		return 0;
634 
635 	(*tp->t_linesw->l_close)(tp, flag);
636 	ttyclose(tp);
637 
638 	if (COM_ISALIVE(sc) == 0)
639 		return 0;
640 
641 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
642 		/*
643 		 * Although we got a last close, the device may still be in
644 		 * use; e.g. if this was the dialout node, and there are still
645 		 * processes waiting for carrier on the non-dialout node.
646 		 */
647 		sacom_shutdown(sc);
648 	}
649 
650 	return 0;
651 }
652 
653 int
654 sacomread(dev_t dev, struct uio *uio, int flag)
655 {
656 	struct sacom_softc *sc =
657 		device_lookup_private(&sacom_cd, COMUNIT(dev));
658 	struct tty *tp = sc->sc_tty;
659 
660 	if (COM_ISALIVE(sc) == 0)
661 		return EIO;
662 
663 	return (*tp->t_linesw->l_read)(tp, uio, flag);
664 }
665 
666 int
667 sacomwrite(dev_t dev, struct uio *uio, int flag)
668 {
669 	struct sacom_softc *sc =
670 		device_lookup_private(&sacom_cd, COMUNIT(dev));
671 	struct tty *tp = sc->sc_tty;
672 
673 	if (COM_ISALIVE(sc) == 0)
674 		return EIO;
675 
676 	return (*tp->t_linesw->l_write)(tp, uio, flag);
677 }
678 
679 int
680 sacompoll(dev_t dev, int events, struct lwp *l)
681 {
682 	struct sacom_softc *sc =
683 		device_lookup_private(&sacom_cd, COMUNIT(dev));
684 	struct tty *tp = sc->sc_tty;
685 
686 	if (COM_ISALIVE(sc) == 0)
687 		return EIO;
688 
689 	return (*tp->t_linesw->l_poll)(tp, events, l);
690 }
691 
692 struct tty *
693 sacomtty(dev_t dev)
694 {
695 	struct sacom_softc *sc =
696 		device_lookup_private(&sacom_cd, COMUNIT(dev));
697 	struct tty *tp = sc->sc_tty;
698 
699 	return tp;
700 }
701 
702 int
703 sacomioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
704 {
705 	struct sacom_softc *sc =
706 		device_lookup_private(&sacom_cd, COMUNIT(dev));
707 	struct tty *tp = sc->sc_tty;
708 	int error;
709 	int s;
710 
711 	if (COM_ISALIVE(sc) == 0)
712 		return EIO;
713 
714 	error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, l);
715 	if (error != EPASSTHROUGH)
716 		return error;
717 
718 	error = ttioctl(tp, cmd, data, flag, l);
719 	if (error != EPASSTHROUGH)
720 		return error;
721 
722 	error = 0;
723 
724 	s = splserial();
725 	COM_LOCK(sc);
726 
727 	switch (cmd) {
728 	case TIOCSBRK:
729 		sacom_break(sc, 1);
730 		break;
731 
732 	case TIOCCBRK:
733 		sacom_break(sc, 0);
734 		break;
735 
736 	case TIOCSDTR:
737 		sacom_modem(sc, 1);
738 		break;
739 
740 	case TIOCCDTR:
741 		sacom_modem(sc, 0);
742 		break;
743 
744 	case TIOCGFLAGS:
745 		*(int *)data = sc->sc_swflags;
746 		break;
747 
748 	case TIOCSFLAGS:
749 		error = kauth_authorize_device_tty(l->l_cred,
750 		    KAUTH_DEVICE_TTY_PRIVSET, tp);
751 		if (error)
752 			break;
753 		sc->sc_swflags = *(int *)data;
754 		break;
755 
756 	case TIOCMSET:
757 	case TIOCMBIS:
758 	case TIOCMBIC:
759 		tiocm_to_sacom(sc, cmd, *(int *)data);
760 		break;
761 
762 	case TIOCMGET:
763 		*(int *)data = sacom_to_tiocm(sc);
764 		break;
765 
766 	default:
767 		error = EPASSTHROUGH;
768 		break;
769 	}
770 
771 	COM_UNLOCK(sc);
772 	splx(s);
773 
774 #ifdef COM_DEBUG
775 	if (sacom_debug)
776 		comstatus(sc, "comioctl ");
777 #endif
778 
779 	return error;
780 }
781 
782 static inline void
783 sacom_schedrx(struct sacom_softc *sc)
784 {
785 
786 	sc->sc_rx_ready = 1;
787 
788 	/* Wake up the poller. */
789 	softint_schedule(sc->sc_si);
790 }
791 
792 void
793 sacom_break(struct sacom_softc *sc, int onoff)
794 {
795 
796 	if (onoff)
797 		SET(sc->sc_cr3, CR3_BRK);
798 	else
799 		CLR(sc->sc_cr3, CR3_BRK);
800 
801 	if (!sc->sc_heldchange) {
802 		if (sc->sc_tx_busy) {
803 			sc->sc_heldtbc = sc->sc_tbc;
804 			sc->sc_tbc = 0;
805 			sc->sc_heldchange = 1;
806 		} else
807 			sacom_loadchannelregs(sc);
808 	}
809 }
810 
811 void
812 sacom_modem(struct sacom_softc *sc, int onoff)
813 {
814 	if (!sc->sc_heldchange) {
815 		if (sc->sc_tx_busy) {
816 			sc->sc_heldtbc = sc->sc_tbc;
817 			sc->sc_tbc = 0;
818 			sc->sc_heldchange = 1;
819 		} else
820 			sacom_loadchannelregs(sc);
821 	}
822 }
823 
824 void
825 tiocm_to_sacom(struct sacom_softc *sc, u_long how, int ttybits)
826 {
827 }
828 
829 int
830 sacom_to_tiocm(struct sacom_softc *sc)
831 {
832 	int ttybits = 0;
833 
834 	if (sc->sc_cr3 != 0)
835 		SET(ttybits, TIOCM_LE);
836 
837 	return ttybits;
838 }
839 
840 static u_int
841 cflag2cr0(tcflag_t cflag)
842 {
843 	u_int cr0;
844 
845 	cr0  = (cflag & PARENB) ? CR0_PE : 0;
846 	cr0 |= (cflag & PARODD) ? 0 : CR0_OES;
847 	cr0 |= (cflag & CSTOPB) ? CR0_SBS : 0;
848 	cr0 |= ((cflag & CSIZE) == CS8) ? CR0_DSS : 0;
849 
850 	return cr0;
851 }
852 
853 int
854 sacomparam(struct tty *tp, struct termios *t)
855 {
856 	struct sacom_softc *sc =
857 		device_lookup_private(&sacom_cd, COMUNIT(tp->t_dev));
858 	int ospeed = SACOMSPEED(t->c_ospeed);
859 	u_int cr0;
860 	int s;
861 
862 	if (COM_ISALIVE(sc) == 0)
863 		return EIO;
864 
865 	/* Check requested parameters. */
866 	if (ospeed < 0)
867 		return EINVAL;
868 	if (t->c_ispeed && t->c_ispeed != t->c_ospeed)
869 		return EINVAL;
870 
871 	/*
872 	 * For the console, always force CLOCAL and !HUPCL, so that the port
873 	 * is always active.
874 	 */
875 	if (ISSET(sc->sc_swflags, TIOCFLAG_SOFTCAR) ||
876 	    ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
877 		SET(t->c_cflag, CLOCAL);
878 		CLR(t->c_cflag, HUPCL);
879 	}
880 
881 	/*
882 	 * If there were no changes, don't do anything.  This avoids dropping
883 	 * input and improves performance when all we did was frob things like
884 	 * VMIN and VTIME.
885 	 */
886 	if (tp->t_ospeed == t->c_ospeed &&
887 	    tp->t_cflag == t->c_cflag)
888 		return 0;
889 
890 	cr0 = cflag2cr0(t->c_cflag);
891 
892 	s = splserial();
893 	COM_LOCK(sc);
894 
895 	sc->sc_cr0 = cr0;
896 
897 	sc->sc_speed = ospeed;
898 
899 	/* And copy to tty. */
900 	tp->t_ispeed = 0;
901 	tp->t_ospeed = t->c_ospeed;
902 	tp->t_cflag = t->c_cflag;
903 
904 	if (!sc->sc_heldchange) {
905 		if (sc->sc_tx_busy) {
906 			sc->sc_heldtbc = sc->sc_tbc;
907 			sc->sc_tbc = 0;
908 			sc->sc_heldchange = 1;
909 		} else
910 			sacom_loadchannelregs(sc);
911 	}
912 
913 	if (!ISSET(t->c_cflag, CHWFLOW)) {
914 		/* Disable the high water mark. */
915 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
916 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
917 			sacom_schedrx(sc);
918 		}
919 		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED)) {
920 			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED);
921 			sacom_hwiflow(sc);
922 		}
923 	}
924 
925 	COM_UNLOCK(sc);
926 	splx(s);
927 
928 	(void) (*tp->t_linesw->l_modem)(tp, 1);
929 
930 #ifdef COM_DEBUG
931 	if (sacom_debug)
932 		comstatus(sc, "comparam ");
933 #endif
934 
935 	return 0;
936 }
937 
938 void
939 sacom_iflush(struct sacom_softc *sc)
940 {
941 	bus_space_tag_t iot = sc->sc_iot;
942 	bus_space_handle_t ioh = sc->sc_ioh;
943 #ifdef DIAGNOSTIC
944 	int reg;
945 #endif
946 	int timo;
947 
948 #ifdef DIAGNOSTIC
949 	reg = 0xffff;
950 #endif
951 	timo = 50;
952 	/* flush any pending I/O */
953 	if (sc->sc_cr3 & CR3_RXE) {
954 	while (ISSET(bus_space_read_4(iot, ioh, SACOM_SR1), SR1_RNE)
955 	    && --timo)
956 #ifdef DIAGNOSTIC
957 		reg =
958 #else
959 		    (void)
960 #endif
961 		    bus_space_read_4(iot, ioh, SACOM_DR);
962 	}
963 #if 0
964 	/* XXX is it good idea to wait TX finish? */
965 	if (sc->sc_cr3 & CR3_TXE) {
966 	timo = 500;
967 	while (ISSET(bus_space_read_4(iot, ioh, SACOM_SR1), SR1_TBY)
968 	    && --timo)
969 		delay(100);
970 	}
971 #endif
972 #ifdef DIAGNOSTIC
973 	if (!timo)
974 		aprint_debug_dev(sc->sc_dev, "sacom_iflush timeout %02x\n", reg);
975 #endif
976 }
977 
978 void
979 sacom_loadchannelregs(struct sacom_softc *sc)
980 {
981 	bus_space_tag_t iot = sc->sc_iot;
982 	bus_space_handle_t ioh = sc->sc_ioh;
983 
984 	/* XXXXX necessary? */
985 	sacom_iflush(sc);
986 
987 	/* Need to stop engines first. */
988 	bus_space_write_4(iot, ioh, SACOM_CR3, 0);
989 
990 	bus_space_write_4(iot, ioh, SACOM_CR1, sc->sc_speed >> 8);
991 	bus_space_write_4(iot, ioh, SACOM_CR2, sc->sc_speed & 0xff);
992 
993 	bus_space_write_4(iot, ioh, SACOM_CR0, sc->sc_cr0);
994 	bus_space_write_4(iot, ioh, SACOM_CR3, sc->sc_cr3);
995 }
996 
997 int
998 sacomhwiflow(struct tty *tp, int block)
999 {
1000 #if 0
1001 	struct sacom_softc *sc =
1002 		device_lookup_private(&sacom_cd, COMUNIT(tp->t_dev));
1003 	int s;
1004 
1005 	if (COM_ISALIVE(sc) == 0)
1006 		return 0;
1007 
1008 	if (sc->sc_mcr_rts == 0)
1009 		return 0;
1010 
1011 	s = splserial();
1012 	COM_LOCK(sc);
1013 
1014 	if (block) {
1015 		if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1016 			SET(sc->sc_rx_flags, RX_TTY_BLOCKED);
1017 			sacom_hwiflow(sc);
1018 		}
1019 	} else {
1020 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
1021 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1022 			sacom_schedrx(sc);
1023 		}
1024 		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1025 			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED);
1026 			sacom_hwiflow(sc);
1027 		}
1028 	}
1029 
1030 	COM_UNLOCK(sc);
1031 	splx(s);
1032 #endif
1033 	return 1;
1034 }
1035 
1036 /*
1037  * (un)block input via hw flowcontrol
1038  */
1039 void
1040 sacom_hwiflow(struct sacom_softc *sc)
1041 {
1042 #if 0
1043 	bus_space_tag_t iot = sc->sc_iot;
1044 	bus_space_handle_t ioh = sc->sc_ioh;
1045 
1046 	/* XXX implement */
1047 #endif
1048 }
1049 
1050 
1051 void
1052 sacomstart(struct tty *tp)
1053 {
1054 	struct sacom_softc *sc =
1055 		device_lookup_private(&sacom_cd, COMUNIT(tp->t_dev));
1056 	bus_space_tag_t iot = sc->sc_iot;
1057 	bus_space_handle_t ioh = sc->sc_ioh;
1058 	int s;
1059 
1060 	if (COM_ISALIVE(sc) == 0)
1061 		return;
1062 
1063 	s = spltty();
1064 	if (ISSET(tp->t_state, TS_BUSY | TS_TIMEOUT | TS_TTSTOP))
1065 		goto out;
1066 	if (!ttypull(tp))
1067 		goto out;
1068 
1069 	/* Grab the first contiguous region of buffer space. */
1070 	{
1071 		u_char *tba;
1072 		int tbc;
1073 
1074 		tba = tp->t_outq.c_cf;
1075 		tbc = ndqb(&tp->t_outq, 0);
1076 
1077 		(void)splserial();
1078 		COM_LOCK(sc);
1079 
1080 		sc->sc_tba = tba;
1081 		sc->sc_tbc = tbc;
1082 	}
1083 
1084 	SET(tp->t_state, TS_BUSY);
1085 	sc->sc_tx_busy = 1;
1086 
1087 	/* Enable transmit completion interrupts if necessary. */
1088 	if (!ISSET(sc->sc_cr3, CR3_TIE)) {
1089 		SET(sc->sc_cr3, CR3_TIE);
1090 		bus_space_write_4(iot, ioh, SACOM_CR3, sc->sc_cr3);
1091 	}
1092 
1093 	/* Output the first chunk of the contiguous buffer. */
1094 	sacom_filltx(sc);
1095 
1096 	COM_UNLOCK(sc);
1097 out:
1098 	splx(s);
1099 	return;
1100 }
1101 
1102 void
1103 sacom_filltx(struct sacom_softc *sc)
1104 {
1105 	bus_space_tag_t iot = sc->sc_iot;
1106 	bus_space_handle_t ioh = sc->sc_ioh;
1107 	int c, n;
1108 
1109 	n = 0;
1110 	while (bus_space_read_4(iot, ioh, SACOM_SR1) & SR1_TNF) {
1111 		if (n == SACOM_TXFIFOLEN || n == sc->sc_tbc)
1112 			break;
1113 		c = *(sc->sc_tba + n);
1114 		c &= 0xff;
1115 		bus_space_write_4(iot, ioh, SACOM_DR, c);
1116 		n++;
1117 	}
1118 	sc->sc_tbc -= n;
1119 	sc->sc_tba += n;
1120 }
1121 
1122 /*
1123  * Stop output on a line.
1124  */
1125 void
1126 sacomstop(struct tty *tp, int flag)
1127 {
1128 	struct sacom_softc *sc =
1129 		device_lookup_private(&sacom_cd, COMUNIT(tp->t_dev));
1130 	int s;
1131 
1132 	s = splserial();
1133 	COM_LOCK(sc);
1134 	if (ISSET(tp->t_state, TS_BUSY)) {
1135 		/* Stop transmitting at the next chunk. */
1136 		sc->sc_tbc = 0;
1137 		sc->sc_heldtbc = 0;
1138 		if (!ISSET(tp->t_state, TS_TTSTOP))
1139 			SET(tp->t_state, TS_FLUSH);
1140 	}
1141 	COM_UNLOCK(sc);
1142 	splx(s);
1143 }
1144 
1145 static inline void
1146 sacom_rxsoft(struct sacom_softc *sc, struct tty *tp)
1147 {
1148 	int (*rint)(int, struct tty *) = tp->t_linesw->l_rint;
1149 	u_char *get, *end;
1150 	u_int cc, scc;
1151 	u_char sr1;
1152 	int code;
1153 	int s;
1154 
1155 	end = sc->sc_ebuf;
1156 	get = sc->sc_rbget;
1157 	scc = cc = SACOM_RING_SIZE - sc->sc_rbavail;
1158 
1159 	while (cc) {
1160 		code = get[0];
1161 		sr1 = get[1];
1162 		if (ISSET(sr1, SR1_FRE))
1163 			SET(code, TTY_FE);
1164 		if (ISSET(sr1, SR1_PRE))
1165 			SET(code, TTY_PE);
1166 		if ((*rint)(code, tp) == -1) {
1167 			/*
1168 			 * The line discipline's buffer is out of space.
1169 			 */
1170 			if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1171 				/*
1172 				 * We're either not using flow control, or the
1173 				 * line discipline didn't tell us to block for
1174 				 * some reason.  Either way, we have no way to
1175 				 * know when there's more space available, so
1176 				 * just drop the rest of the data.
1177 				 */
1178 				get += cc << 1;
1179 				if (get >= end)
1180 					get -= SACOM_RING_SIZE << 1;
1181 				cc = 0;
1182 			} else {
1183 				/*
1184 				 * Don't schedule any more receive processing
1185 				 * until the line discipline tells us there's
1186 				 * space available (through comhwiflow()).
1187 				 * Leave the rest of the data in the input
1188 				 * buffer.
1189 				 */
1190 				SET(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1191 			}
1192 			break;
1193 		}
1194 		get += 2;
1195 		if (get >= end)
1196 			get = sc->sc_rbuf;
1197 		cc--;
1198 	}
1199 
1200 	if (cc != scc) {
1201 		sc->sc_rbget = get;
1202 		s = splserial();
1203 		COM_LOCK(sc);
1204 
1205 		cc = sc->sc_rbavail += scc - cc;
1206 		/* Buffers should be ok again, release possible block. */
1207 		if (cc >= 1) {
1208 			if (ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
1209 				CLR(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
1210 				SET(sc->sc_cr3, CR3_RIE);
1211 				bus_space_write_4(sc->sc_iot, sc->sc_ioh,
1212 						  SACOM_CR3, sc->sc_cr3);
1213 			}
1214 		}
1215 		COM_UNLOCK(sc);
1216 		splx(s);
1217 	}
1218 }
1219 
1220 static inline void
1221 sacom_txsoft(struct sacom_softc *sc, struct tty *tp)
1222 {
1223 
1224 	CLR(tp->t_state, TS_BUSY);
1225 	if (ISSET(tp->t_state, TS_FLUSH))
1226 		CLR(tp->t_state, TS_FLUSH);
1227 	else
1228 		ndflush(&tp->t_outq, (int)(sc->sc_tba - tp->t_outq.c_cf));
1229 	(*tp->t_linesw->l_start)(tp);
1230 }
1231 
1232 static inline void
1233 sacom_stsoft(struct sacom_softc *sc, struct tty *tp)
1234 {
1235 }
1236 
1237 void
1238 sacomsoft(void *arg)
1239 {
1240 	struct sacom_softc *sc = arg;
1241 	struct tty *tp;
1242 
1243 	if (COM_ISALIVE(sc) == 0)
1244 		return;
1245 
1246 	tp = sc->sc_tty;
1247 
1248 	if (sc->sc_rx_ready) {
1249 		sc->sc_rx_ready = 0;
1250 		sacom_rxsoft(sc, tp);
1251 	}
1252 
1253 	if (sc->sc_st_check) {
1254 		sc->sc_st_check = 0;
1255 		sacom_stsoft(sc, tp);
1256 	}
1257 
1258 	if (sc->sc_tx_done) {
1259 		sc->sc_tx_done = 0;
1260 		sacom_txsoft(sc, tp);
1261 	}
1262 }
1263 
1264 int
1265 sacomintr(void *arg)
1266 {
1267 	struct sacom_softc *sc = arg;
1268 	bus_space_tag_t iot = sc->sc_iot;
1269 	bus_space_handle_t ioh = sc->sc_ioh;
1270 	u_char *put, *end;
1271 	u_int cc;
1272 	u_int sr0, sr1;
1273 
1274 	if (COM_ISALIVE(sc) == 0)
1275 		return 0;
1276 
1277 	COM_LOCK(sc);
1278 	sr0 = bus_space_read_4(iot, ioh, SACOM_SR0);
1279 	if (!sr0) {
1280 		COM_UNLOCK(sc);
1281 		return 0;
1282 	}
1283 	if (ISSET(sr0, SR0_EIF))
1284 		/* XXX silently discard error bits */
1285 		bus_space_read_4(iot, ioh, SACOM_DR);
1286 	if (ISSET(sr0, SR0_RBB))
1287 		bus_space_write_4(iot, ioh, SACOM_SR0, SR0_RBB);
1288 	if (ISSET(sr0, SR0_REB)) {
1289 		bus_space_write_4(iot, ioh, SACOM_SR0, SR0_REB);
1290 #if defined(DDB) || defined(KGDB)
1291 #ifndef DDB_BREAK_CHAR
1292 		if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
1293 			console_debugger();
1294 		}
1295 #endif
1296 #endif /* DDB || KGDB */
1297 	}
1298 
1299 
1300 	end = sc->sc_ebuf;
1301 	put = sc->sc_rbput;
1302 	cc = sc->sc_rbavail;
1303 
1304 	sr1 = bus_space_read_4(iot, ioh, SACOM_SR1);
1305 	if (ISSET(sr0, SR0_RFS | SR0_RID)) {
1306 		if (!ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
1307 			while (cc > 0) {
1308 				if (!ISSET(sr1, SR1_RNE)) {
1309 					bus_space_write_4(iot, ioh, SACOM_SR0,
1310 							  SR0_RID);
1311 					break;
1312 				}
1313 				put[0] = bus_space_read_4(iot, ioh, SACOM_DR);
1314 				put[1] = sr1;
1315 #if defined(DDB) && defined(DDB_BREAK_CHAR)
1316 				if (put[0] == DDB_BREAK_CHAR &&
1317 				    ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
1318 					console_debugger();
1319 
1320 					sr1 = bus_space_read_4(iot, ioh, SACOM_SR1);
1321 					continue;
1322 				}
1323 #endif
1324 				put += 2;
1325 				if (put >= end)
1326 					put = sc->sc_rbuf;
1327 				cc--;
1328 
1329 				sr1 = bus_space_read_4(iot, ioh, SACOM_SR1);
1330 			}
1331 
1332 			/*
1333 			 * Current string of incoming characters ended because
1334 			 * no more data was available or we ran out of space.
1335 			 * Schedule a receive event if any data was received.
1336 			 * If we're out of space, turn off receive interrupts.
1337 			 */
1338 			sc->sc_rbput = put;
1339 			sc->sc_rbavail = cc;
1340 			if (!ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED))
1341 				sc->sc_rx_ready = 1;
1342 
1343 			/* XXX do RX hardware flow control */
1344 
1345 			/*
1346 			 * If we're out of space, disable receive interrupts
1347 			 * until the queue has drained a bit.
1348 			 */
1349 			if (!cc) {
1350 				SET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
1351 				CLR(sc->sc_cr3, CR3_RIE);
1352 				bus_space_write_4(iot, ioh, SACOM_CR3,
1353 						  sc->sc_cr3);
1354 			}
1355 		} else {
1356 #ifdef DIAGNOSTIC
1357 			panic("sacomintr: we shouldn't reach here");
1358 #endif
1359 			CLR(sc->sc_cr3, CR3_RIE);
1360 			bus_space_write_4(iot, ioh, SACOM_CR3, sc->sc_cr3);
1361 		}
1362 	}
1363 
1364 	/*
1365 	 * Done handling any receive interrupts. See if data can be
1366 	 * transmitted as well. Schedule tx done event if no data left
1367 	 * and tty was marked busy.
1368 	 */
1369 	sr0 = bus_space_read_4(iot, ioh, SACOM_SR0);
1370 	if (ISSET(sr0, SR0_TFS)) {
1371 		/*
1372 		 * If we've delayed a parameter change, do it now, and restart
1373 		 * output.
1374 		 * XXX sacom_loadchannelregs() waits TX completion,
1375 		 * XXX resulting in ~0.1s hang (300bps, 4 bytes) in worst case
1376 		 */
1377 		if (sc->sc_heldchange) {
1378 			sacom_loadchannelregs(sc);
1379 			sc->sc_heldchange = 0;
1380 			sc->sc_tbc = sc->sc_heldtbc;
1381 			sc->sc_heldtbc = 0;
1382 		}
1383 
1384 		/* Output the next chunk of the contiguous buffer, if any. */
1385 		if (sc->sc_tbc > 0) {
1386 			sacom_filltx(sc);
1387 		} else {
1388 			/* Disable transmit completion interrupts if necessary. */
1389 			if (ISSET(sc->sc_cr3, CR3_TIE)) {
1390 				CLR(sc->sc_cr3, CR3_TIE);
1391 				bus_space_write_4(iot, ioh, SACOM_CR3,
1392 						  sc->sc_cr3);
1393 			}
1394 			if (sc->sc_tx_busy) {
1395 				sc->sc_tx_busy = 0;
1396 				sc->sc_tx_done = 1;
1397 			}
1398 		}
1399 	}
1400 	COM_UNLOCK(sc);
1401 
1402 	/* Wake up the poller. */
1403 	softint_schedule(sc->sc_si);
1404 
1405 #if NRND > 0 && defined(RND_COM)
1406 	rnd_add_uint32(&sc->rnd_source, iir | lsr);
1407 #endif
1408 	return 1;
1409 }
1410 
1411 static void
1412 sacom_j720_init(struct sa11x0_softc *parent, struct sacom_softc *sc) {
1413 
1414 	/* XXX  this should be done at sc->enable function */
1415 	bus_space_write_4(parent->sc_iot, parent->sc_gpioh,
1416 	    SAGPIO_PCR, 0xa0000);
1417 	bus_space_write_4(parent->sc_iot, parent->sc_gpioh,
1418 	    SAGPIO_PSR, 0x100);
1419 }
1420 
1421 /* Initialization for serial console */
1422 int
1423 sacominit(bus_space_tag_t iot, bus_addr_t iobase, int baud, tcflag_t cflag,
1424     bus_space_handle_t *iohp)
1425 {
1426 	int brd, cr0;
1427 
1428 	if (bus_space_map(iot, iobase, SACOM_NPORTS, 0, iohp))
1429 		aprint_normal("register map failed\n");
1430 
1431 	/* wait for the Tx queue to drain and disable the UART */
1432 	while (bus_space_read_4(iot, *iohp, SACOM_SR1) & SR1_TBY)
1433 		continue;
1434 	bus_space_write_4(iot, *iohp, SACOM_CR3, 0);
1435 
1436 	cr0  = cflag2cr0(cflag);
1437 	bus_space_write_4(iot, *iohp, SACOM_CR0, cr0);
1438 
1439 	brd = SACOMSPEED(baud);
1440 	sacomconsrate = baud;
1441 	sacomconsaddr = iobase;
1442 	sacomconscflag = cflag;
1443 	/* XXX assumes little endian */
1444 	bus_space_write_4(iot, *iohp, SACOM_CR1, brd >> 8);
1445 	bus_space_write_4(iot, *iohp, SACOM_CR2, brd & 0xff);
1446 
1447 	/* enable the UART */
1448 	bus_space_write_4(iot, *iohp, SACOM_CR3, CR3_RXE | CR3_TXE);
1449 
1450 	return 0;
1451 }
1452 
1453 void
1454 sacomcnprobe(struct consdev *cp)
1455 {
1456 	cp->cn_pri = CN_REMOTE;
1457 }
1458 
1459 void
1460 sacomcninit(struct consdev *cp)
1461 {
1462 	if (cp == NULL) {
1463 		/* XXX cp == NULL means that MMU is disabled. */
1464 		sacomconsioh = SACOM3_BASE;
1465 		sacomconstag = &sa11x0_bs_tag;
1466 		cn_tab = &sacomcons;
1467 		return;
1468 	}
1469 
1470 	if (sacominit(&sa11x0_bs_tag, CONADDR, CONSPEED,
1471 			  CONMODE, &sacomconsioh))
1472 		panic("can't init serial console @%x", CONADDR);
1473 	cn_tab = &sacomcons;
1474 	sacomconstag = &sa11x0_bs_tag;
1475 }
1476 
1477 int
1478 sacomcngetc(dev_t dev)
1479 {
1480 	int c, s;
1481 
1482 	s = spltty();	/* XXX do we need this? */
1483 
1484 	while (!(bus_space_read_4(sacomconstag, sacomconsioh, SACOM_SR1)
1485 		 & SR1_RNE)) {
1486 #if defined(DDB) || defined(KGDB)
1487 #ifndef DDB_BREAK_CHAR
1488 		u_int sr0;
1489 		extern int db_active;
1490 
1491 		sr0 = bus_space_read_4(sacomconstag, sacomconsioh, SACOM_SR0);
1492 		if (ISSET(sr0, SR0_RBB))
1493 			bus_space_write_4(sacomconstag, sacomconsioh,
1494 					  SACOM_SR0, SR0_RBB);
1495 		if (ISSET(sr0, SR0_REB)) {
1496 			bus_space_write_4(sacomconstag, sacomconsioh,
1497 					  SACOM_SR0, SR0_REB);
1498 			if (db_active == 0)
1499 				console_debugger();
1500 		}
1501 #endif
1502 #endif /* DDB || KGDB */
1503 	}
1504 
1505 	c = bus_space_read_4(sacomconstag, sacomconsioh, SACOM_DR);
1506 	c &= 0xff;
1507 	splx(s);
1508 
1509 	return c;
1510 }
1511 
1512 void
1513 sacomcnputc(dev_t dev, int c)
1514 {
1515 	int s;
1516 
1517 	s = spltty();	/* XXX do we need this? */
1518 
1519 	while (!(bus_space_read_4(sacomconstag, sacomconsioh, SACOM_SR1)
1520 	    & SR1_TNF))
1521 		continue;
1522 
1523 	bus_space_write_4(sacomconstag, sacomconsioh, SACOM_DR, c);
1524 	splx(s);
1525 }
1526 
1527 void
1528 sacomcnpollc(dev_t dev, int on)
1529 {
1530 
1531 }
1532 
1533 #if 0
1534 #ifdef DEBUG
1535 int
1536 sacomcncharpoll(void)
1537 {
1538 	int c;
1539 
1540 	if (!(bus_space_read_4(sacomconstag, sacomconsioh, SACOM_SR1)
1541 		 & SR1_RNE))
1542 		return -1;
1543 
1544 	c = bus_space_read_4(sacomconstag, sacomconsioh, SACOM_DR);
1545 	c &= 0xff;
1546 
1547 	return c;
1548 }
1549 #endif
1550 #endif
1551 
1552 /* helper function to identify the com ports used by
1553  console or KGDB (and not yet autoconf attached) */
1554 int
1555 sacom_is_console(bus_space_tag_t iot, bus_addr_t iobase,
1556     bus_space_handle_t *ioh)
1557 {
1558 	bus_space_handle_t help;
1559 
1560 	if (!sacomconsattached &&
1561 	    iot == sacomconstag && iobase == sacomconsaddr)
1562 		help = sacomconsioh;
1563 	else
1564 		return 0;
1565 
1566 	if (ioh)
1567 		*ioh = help;
1568 	return 1;
1569 }
1570