xref: /netbsd-src/sys/arch/sh3/dev/sci.c (revision 53b02e147d4ed531c0d2a5ca9b3e8026ba3e99b5)
1 /* $NetBSD: sci.c,v 1.63 2020/11/21 17:25:52 thorpej Exp $ */
2 
3 /*-
4  * Copyright (C) 1999 T.Horiuchi and SAITOH Masanobu.  All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. The name of the author may not be used to endorse or promote products
15  *    derived from this software without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 /*-
30  * Copyright (c) 1998, 1999 The NetBSD Foundation, Inc.
31  * All rights reserved.
32  *
33  * This code is derived from software contributed to The NetBSD Foundation
34  * by Charles M. Hannum.
35  *
36  * Redistribution and use in source and binary forms, with or without
37  * modification, are permitted provided that the following conditions
38  * are met:
39  * 1. Redistributions of source code must retain the above copyright
40  *    notice, this list of conditions and the following disclaimer.
41  * 2. Redistributions in binary form must reproduce the above copyright
42  *    notice, this list of conditions and the following disclaimer in the
43  *    documentation and/or other materials provided with the distribution.
44  *
45  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
46  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
47  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
48  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
49  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
50  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
51  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
52  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
53  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
54  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
55  * POSSIBILITY OF SUCH DAMAGE.
56  */
57 
58 /*
59  * Copyright (c) 1991 The Regents of the University of California.
60  * All rights reserved.
61  *
62  * Redistribution and use in source and binary forms, with or without
63  * modification, are permitted provided that the following conditions
64  * are met:
65  * 1. Redistributions of source code must retain the above copyright
66  *    notice, this list of conditions and the following disclaimer.
67  * 2. Redistributions in binary form must reproduce the above copyright
68  *    notice, this list of conditions and the following disclaimer in the
69  *    documentation and/or other materials provided with the distribution.
70  * 3. Neither the name of the University nor the names of its contributors
71  *    may be used to endorse or promote products derived from this software
72  *    without specific prior written permission.
73  *
74  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
75  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
76  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
77  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
78  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
79  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
80  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
81  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
82  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
83  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
84  * SUCH DAMAGE.
85  *
86  *	@(#)com.c	7.5 (Berkeley) 5/16/91
87  */
88 
89 /*
90  * SH internal serial driver
91  *
92  * This code is derived from both z8530tty.c and com.c
93  */
94 
95 #include <sys/cdefs.h>
96 __KERNEL_RCSID(0, "$NetBSD: sci.c,v 1.63 2020/11/21 17:25:52 thorpej Exp $");
97 
98 #include "opt_kgdb.h"
99 #include "opt_sci.h"
100 
101 #include <sys/param.h>
102 #include <sys/systm.h>
103 #include <sys/tty.h>
104 #include <sys/proc.h>
105 #include <sys/conf.h>
106 #include <sys/file.h>
107 #include <sys/syslog.h>
108 #include <sys/kernel.h>
109 #include <sys/device.h>
110 #include <sys/kmem.h>
111 #include <sys/kauth.h>
112 #include <sys/intr.h>
113 
114 #include <dev/cons.h>
115 
116 #include <sh3/clock.h>
117 #include <sh3/scireg.h>
118 #include <sh3/pfcreg.h>
119 #include <sh3/tmureg.h>
120 #include <sh3/exception.h>
121 
122 static void	scistart(struct tty *);
123 static int	sciparam(struct tty *, struct termios *);
124 
125 void scicnprobe(struct consdev *);
126 void scicninit(struct consdev *);
127 void scicnputc(dev_t, int);
128 int scicngetc(dev_t);
129 void scicnpoolc(dev_t, int);
130 int sciintr(void *);
131 
132 struct sci_softc {
133 	device_t sc_dev;		/* boilerplate */
134 	struct tty *sc_tty;
135 	void *sc_si;
136 	callout_t sc_diag_ch;
137 
138 #if 0
139 	bus_space_tag_t sc_iot;		/* ISA i/o space identifier */
140 	bus_space_handle_t   sc_ioh;	/* ISA io handle */
141 
142 	int sc_drq;
143 
144 	int sc_frequency;
145 #endif
146 
147 	u_int sc_overflows,
148 	      sc_floods,
149 	      sc_errors;		/* number of retries so far */
150 	u_char sc_status[7];		/* copy of registers */
151 
152 	int sc_hwflags;
153 	int sc_swflags;
154 	u_int sc_fifolen;		/* XXX always 0? */
155 
156 	u_int sc_r_hiwat,
157 	      sc_r_lowat;
158 	u_char *volatile sc_rbget,
159 	       *volatile sc_rbput;
160  	volatile u_int sc_rbavail;
161 	u_char *sc_rbuf,
162 	       *sc_ebuf;
163 
164  	u_char *sc_tba;			/* transmit buffer address */
165  	u_int sc_tbc,			/* transmit byte count */
166 	      sc_heldtbc;
167 
168 	volatile u_char sc_rx_flags,	/* receiver blocked */
169 #define	RX_TTY_BLOCKED		0x01
170 #define	RX_TTY_OVERFLOWED	0x02
171 #define	RX_IBUF_BLOCKED		0x04
172 #define	RX_IBUF_OVERFLOWED	0x08
173 #define	RX_ANY_BLOCK		0x0f
174 			sc_tx_busy,	/* working on an output chunk */
175 			sc_tx_done,	/* done with one output chunk */
176 			sc_tx_stopped,	/* H/W level stop (lost CTS) */
177 			sc_st_check,	/* got a status interrupt */
178 			sc_rx_ready;
179 
180 	volatile u_char sc_heldchange;
181 };
182 
183 /* controller driver configuration */
184 static int sci_match(device_t, cfdata_t, void *);
185 static void sci_attach(device_t, device_t, void *);
186 
187 void	sci_break(struct sci_softc *, int);
188 void	sci_iflush(struct sci_softc *);
189 
190 #define	integrate	static inline
191 void 	scisoft(void *);
192 
193 integrate void sci_rxsoft(struct sci_softc *, struct tty *);
194 integrate void sci_txsoft(struct sci_softc *, struct tty *);
195 integrate void sci_stsoft(struct sci_softc *, struct tty *);
196 integrate void sci_schedrx(struct sci_softc *);
197 void	scidiag(void *);
198 
199 #define	SCIUNIT(x)	TTUNIT(x)
200 #define	SCIDIALOUT(x)	TTDIALOUT(x)
201 
202 /* Hardware flag masks */
203 #define	SCI_HW_NOIEN	0x01
204 #define	SCI_HW_FIFO	0x02
205 #define	SCI_HW_FLOW	0x08
206 #define	SCI_HW_DEV_OK	0x20
207 #define	SCI_HW_CONSOLE	0x40
208 #define	SCI_HW_KGDB	0x80
209 
210 /* Buffer size for character buffer */
211 #define	SCI_RING_SIZE	2048
212 
213 /* Stop input when 3/4 of the ring is full; restart when only 1/4 is full. */
214 u_int sci_rbuf_hiwat = (SCI_RING_SIZE * 1) / 4;
215 u_int sci_rbuf_lowat = (SCI_RING_SIZE * 3) / 4;
216 
217 #define	CONMODE ((TTYDEF_CFLAG & ~(CSIZE | CSTOPB | PARENB)) | CS8) /* 8N1 */
218 int sciconscflag = CONMODE;
219 int sciisconsole = 0;
220 
221 #ifdef SCICN_SPEED
222 int scicn_speed = SCICN_SPEED;
223 #else
224 int scicn_speed = 9600;
225 #endif
226 
227 #define	divrnd(n, q)	(((n)*2/(q)+1)/2)	/* divide and round off */
228 
229 u_int sci_rbuf_size = SCI_RING_SIZE;
230 
231 CFATTACH_DECL_NEW(sci, sizeof(struct sci_softc),
232     sci_match, sci_attach, NULL, NULL);
233 
234 extern struct cfdriver sci_cd;
235 
236 static int sci_attached;
237 
238 dev_type_open(sciopen);
239 dev_type_close(sciclose);
240 dev_type_read(sciread);
241 dev_type_write(sciwrite);
242 dev_type_ioctl(sciioctl);
243 dev_type_stop(scistop);
244 dev_type_tty(scitty);
245 dev_type_poll(scipoll);
246 
247 const struct cdevsw sci_cdevsw = {
248 	.d_open = sciopen,
249 	.d_close = sciclose,
250 	.d_read = sciread,
251 	.d_write = sciwrite,
252 	.d_ioctl = sciioctl,
253 	.d_stop = scistop,
254 	.d_tty = scitty,
255 	.d_poll = scipoll,
256 	.d_mmap = nommap,
257 	.d_kqfilter = ttykqfilter,
258 	.d_discard = nodiscard,
259 	.d_flag = D_TTY
260 };
261 
262 void InitializeSci (unsigned int);
263 
264 /*
265  * following functions are debugging prupose only
266  */
267 #define	CR      0x0D
268 #define	I2C_ADRS (*(volatile unsigned int *)0xa8000000)
269 #define	USART_ON (unsigned int)~0x08
270 
271 void sci_putc(unsigned char);
272 unsigned char sci_getc(void);
273 int SciErrCheck(void);
274 
275 /*
276  * InitializeSci
277  * : unsigned int bps;
278  * : SCI(Serial Communication Interface)
279  */
280 
281 void
282 InitializeSci(unsigned int bps)
283 {
284 
285 	/* Initialize SCR */
286 	SHREG_SCSCR = 0x00;
287 
288 	/* Serial Mode Register */
289 	SHREG_SCSMR = 0x00;	/* Async,8bit,NonParity,Even,1Stop,NoMulti */
290 
291 	/* Bit Rate Register */
292 	SHREG_SCBRR = divrnd(sh_clock_get_pclock(), 32 * bps) - 1;
293 
294 	/*
295 	 * wait 1mSec, because Send/Recv must begin 1 bit period after
296 	 * BRR is set.
297 	 */
298 	delay(1000);
299 
300 	/* Send permission, Receive permission ON */
301 	SHREG_SCSCR = SCSCR_TE | SCSCR_RE;
302 
303 	/* Serial Status Register */
304 	SHREG_SCSSR &= SCSSR_TDRE;	/* Clear Status */
305 
306 #if 0
307 	I2C_ADRS &= ~0x08;	/* enable RS-232C */
308 #endif
309 }
310 
311 
312 /*
313  * sci_putc
314  *  : unsigned char c;
315  */
316 void
317 sci_putc(unsigned char c)
318 {
319 
320 	/* wait for ready */
321 	while ((SHREG_SCSSR & SCSSR_TDRE) == 0)
322 		;
323 
324 	/* write send data to send register */
325 	SHREG_SCTDR = c;
326 
327 	/* clear ready flag */
328 	SHREG_SCSSR &= ~SCSSR_TDRE;
329 }
330 
331 /*
332  * : SciErrCheck
333  *	0x20 = over run
334  *	0x10 = frame error
335  *	0x80 = parity error
336  */
337 int
338 SciErrCheck(void)
339 {
340 
341 	return(SHREG_SCSSR & (SCSSR_ORER | SCSSR_FER | SCSSR_PER));
342 }
343 
344 /*
345  * sci_getc
346  */
347 unsigned char
348 sci_getc(void)
349 {
350 	unsigned char c, err_c;
351 
352 	while (((err_c = SHREG_SCSSR)
353 		& (SCSSR_RDRF | SCSSR_ORER | SCSSR_FER | SCSSR_PER)) == 0)
354 		;
355 	if ((err_c & (SCSSR_ORER | SCSSR_FER | SCSSR_PER)) != 0) {
356 		SHREG_SCSSR &= ~(SCSSR_ORER | SCSSR_FER | SCSSR_PER);
357 		return(err_c |= 0x80);
358 	}
359 
360 	c = SHREG_SCRDR;
361 
362 	SHREG_SCSSR &= ~SCSSR_RDRF;
363 
364 	return(c);
365 }
366 
367 static int
368 sci_match(device_t parent, cfdata_t cf, void *aux)
369 {
370 
371 	if (strcmp(cf->cf_name, "sci") || sci_attached)
372 		return 0;
373 
374 	return 1;
375 }
376 
377 static void
378 sci_attach(device_t parent, device_t self, void *aux)
379 {
380 	struct sci_softc *sc = device_private(self);
381 	struct tty *tp;
382 
383 	sci_attached = 1;
384 
385 	sc->sc_dev = self;
386 	sc->sc_hwflags = 0;	/* XXX */
387 	sc->sc_swflags = 0;	/* XXX */
388 	sc->sc_fifolen = 0;	/* XXX */
389 
390 	if (sciisconsole) {
391 		SET(sc->sc_hwflags, SCI_HW_CONSOLE);
392 		SET(sc->sc_swflags, TIOCFLAG_SOFTCAR);
393 		printf("\n%s: console\n", device_xname(self));
394 	} else {
395 		InitializeSci(9600);
396 		printf("\n");
397 	}
398 
399 	callout_init(&sc->sc_diag_ch, 0);
400 
401 	intc_intr_establish(SH_INTEVT_SCI_ERI, IST_LEVEL, IPL_SERIAL, sciintr,
402 	    sc);
403 	intc_intr_establish(SH_INTEVT_SCI_RXI, IST_LEVEL, IPL_SERIAL, sciintr,
404 	    sc);
405 	intc_intr_establish(SH_INTEVT_SCI_TXI, IST_LEVEL, IPL_SERIAL, sciintr,
406 	    sc);
407 	intc_intr_establish(SH_INTEVT_SCI_TEI, IST_LEVEL, IPL_SERIAL, sciintr,
408 	    sc);
409 
410 	sc->sc_si = softint_establish(SOFTINT_SERIAL, scisoft, sc);
411 	SET(sc->sc_hwflags, SCI_HW_DEV_OK);
412 
413 	tp = tty_alloc();
414 	tp->t_oproc = scistart;
415 	tp->t_param = sciparam;
416 	tp->t_hwiflow = NULL;
417 
418 	sc->sc_tty = tp;
419 	sc->sc_rbuf = kmem_alloc(sci_rbuf_size << 1, KM_SLEEP);
420 	sc->sc_ebuf = sc->sc_rbuf + (sci_rbuf_size << 1);
421 
422 	tty_attach(tp);
423 }
424 
425 /*
426  * Start or restart transmission.
427  */
428 static void
429 scistart(struct tty *tp)
430 {
431 	struct sci_softc *sc = device_lookup_private(&sci_cd,SCIUNIT(tp->t_dev));
432 	int s;
433 
434 	s = spltty();
435 	if (ISSET(tp->t_state, TS_BUSY | TS_TIMEOUT | TS_TTSTOP))
436 		goto out;
437 	if (sc->sc_tx_stopped)
438 		goto out;
439 	if (!ttypull(tp))
440 		goto out;
441 
442 	/* Grab the first contiguous region of buffer space. */
443 	{
444 		u_char *tba;
445 		int tbc;
446 
447 		tba = tp->t_outq.c_cf;
448 		tbc = ndqb(&tp->t_outq, 0);
449 
450 		(void)splserial();
451 
452 		sc->sc_tba = tba;
453 		sc->sc_tbc = tbc;
454 	}
455 
456 	SET(tp->t_state, TS_BUSY);
457 	sc->sc_tx_busy = 1;
458 
459 	/* Enable transmit completion interrupts if necessary. */
460 	SHREG_SCSCR |= SCSCR_TIE | SCSCR_RIE;
461 
462 	/* Output the first byte of the contiguous buffer. */
463 	{
464 		if (sc->sc_tbc > 0) {
465 			sci_putc(*(sc->sc_tba));
466 			sc->sc_tba++;
467 			sc->sc_tbc--;
468 		}
469 	}
470 out:
471 	splx(s);
472 	return;
473 }
474 
475 /*
476  * Set SCI tty parameters from termios.
477  * XXX - Should just copy the whole termios after
478  * making sure all the changes could be done.
479  */
480 static int
481 sciparam(struct tty *tp, struct termios *t)
482 {
483 	struct sci_softc *sc = device_lookup_private(&sci_cd, SCIUNIT(tp->t_dev));
484 	int ospeed = t->c_ospeed;
485 	int s;
486 
487 	if (!device_is_active(sc->sc_dev))
488 		return (EIO);
489 
490 	/* Check requested parameters. */
491 	if (ospeed < 0)
492 		return (EINVAL);
493 	if (t->c_ispeed && t->c_ispeed != t->c_ospeed)
494 		return (EINVAL);
495 
496 	/*
497 	 * For the console, always force CLOCAL and !HUPCL, so that the port
498 	 * is always active.
499 	 */
500 	if (ISSET(sc->sc_swflags, TIOCFLAG_SOFTCAR) ||
501 	    ISSET(sc->sc_hwflags, SCI_HW_CONSOLE)) {
502 		SET(t->c_cflag, CLOCAL);
503 		CLR(t->c_cflag, HUPCL);
504 	}
505 
506 	/*
507 	 * If there were no changes, don't do anything.  This avoids dropping
508 	 * input and improves performance when all we did was frob things like
509 	 * VMIN and VTIME.
510 	 */
511 	if (tp->t_ospeed == t->c_ospeed &&
512 	    tp->t_cflag == t->c_cflag)
513 		return (0);
514 
515 #if 0
516 /* XXX (msaitoh) */
517 	lcr = ISSET(sc->sc_lcr, LCR_SBREAK) | cflag2lcr(t->c_cflag);
518 #endif
519 
520 	s = splserial();
521 
522 	/*
523 	 * Set the FIFO threshold based on the receive speed.
524 	 *
525 	 *  * If it's a low speed, it's probably a mouse or some other
526 	 *    interactive device, so set the threshold low.
527 	 *  * If it's a high speed, trim the trigger level down to prevent
528 	 *    overflows.
529 	 *  * Otherwise set it a bit higher.
530 	 */
531 #if 0
532 /* XXX (msaitoh) */
533 	if (ISSET(sc->sc_hwflags, SCI_HW_HAYESP))
534 		sc->sc_fifo = FIFO_DMA_MODE | FIFO_ENABLE | FIFO_TRIGGER_8;
535 	else if (ISSET(sc->sc_hwflags, SCI_HW_FIFO))
536 		sc->sc_fifo = FIFO_ENABLE |
537 		    (t->c_ospeed <= 1200 ? FIFO_TRIGGER_1 :
538 		     t->c_ospeed <= 38400 ? FIFO_TRIGGER_8 : FIFO_TRIGGER_4);
539 	else
540 		sc->sc_fifo = 0;
541 #endif
542 
543 	/* And copy to tty. */
544 	tp->t_ispeed = 0;
545 	tp->t_ospeed = t->c_ospeed;
546 	tp->t_cflag = t->c_cflag;
547 
548 	if (!sc->sc_heldchange) {
549 		if (sc->sc_tx_busy) {
550 			sc->sc_heldtbc = sc->sc_tbc;
551 			sc->sc_tbc = 0;
552 			sc->sc_heldchange = 1;
553 		}
554 #if 0
555 /* XXX (msaitoh) */
556 		else
557 			sci_loadchannelregs(sc);
558 #endif
559 	}
560 
561 	if (!ISSET(t->c_cflag, CHWFLOW)) {
562 		/* Disable the high water mark. */
563 		sc->sc_r_hiwat = 0;
564 		sc->sc_r_lowat = 0;
565 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
566 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
567 			sci_schedrx(sc);
568 		}
569 	} else {
570 		sc->sc_r_hiwat = sci_rbuf_hiwat;
571 		sc->sc_r_lowat = sci_rbuf_lowat;
572 	}
573 
574 	splx(s);
575 
576 #ifdef SCI_DEBUG
577 	if (sci_debug)
578 		scistatus(sc, "sciparam ");
579 #endif
580 
581 	if (!ISSET(t->c_cflag, CHWFLOW)) {
582 		if (sc->sc_tx_stopped) {
583 			sc->sc_tx_stopped = 0;
584 			scistart(tp);
585 		}
586 	}
587 
588 	return (0);
589 }
590 
591 void
592 sci_iflush(struct sci_softc *sc)
593 {
594 	unsigned char err_c;
595 
596 	if (((err_c = SHREG_SCSSR)
597 	     & (SCSSR_RDRF | SCSSR_ORER | SCSSR_FER | SCSSR_PER)) != 0) {
598 
599 		if ((err_c & (SCSSR_ORER | SCSSR_FER | SCSSR_PER)) != 0) {
600 			SHREG_SCSSR &= ~(SCSSR_ORER | SCSSR_FER | SCSSR_PER);
601 			return;
602 		}
603 
604 		(void)SHREG_SCRDR;
605 
606 		SHREG_SCSSR &= ~SCSSR_RDRF;
607 	}
608 }
609 
610 int
611 sciopen(dev_t dev, int flag, int mode, struct lwp *l)
612 {
613 	struct sci_softc *sc;
614 	struct tty *tp;
615 	int s, s2;
616 	int error;
617 
618 	sc = device_lookup_private(&sci_cd, SCIUNIT(dev));
619 	if (sc == 0 || !ISSET(sc->sc_hwflags, SCI_HW_DEV_OK) ||
620 	    sc->sc_rbuf == NULL)
621 		return (ENXIO);
622 
623 	if (!device_is_active(sc->sc_dev))
624 		return (ENXIO);
625 
626 #ifdef KGDB
627 	/*
628 	 * If this is the kgdb port, no other use is permitted.
629 	 */
630 	if (ISSET(sc->sc_hwflags, SCI_HW_KGDB))
631 		return (EBUSY);
632 #endif
633 
634 	tp = sc->sc_tty;
635 
636 	if (kauth_authorize_device_tty(l->l_cred, KAUTH_DEVICE_TTY_OPEN, tp))
637 		return (EBUSY);
638 
639 	s = spltty();
640 
641 	/*
642 	 * Do the following iff this is a first open.
643 	 */
644 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
645 		struct termios t;
646 
647 		tp->t_dev = dev;
648 
649 		s2 = splserial();
650 
651 		/* Turn on interrupts. */
652 		SHREG_SCSCR |= SCSCR_TIE | SCSCR_RIE;
653 
654 		splx(s2);
655 
656 		/*
657 		 * Initialize the termios status to the defaults.  Add in the
658 		 * sticky bits from TIOCSFLAGS.
659 		 */
660 		t.c_ispeed = 0;
661 		if (ISSET(sc->sc_hwflags, SCI_HW_CONSOLE)) {
662 			t.c_ospeed = scicn_speed;
663 			t.c_cflag = sciconscflag;
664 		} else {
665 			t.c_ospeed = TTYDEF_SPEED;
666 			t.c_cflag = TTYDEF_CFLAG;
667 		}
668 		if (ISSET(sc->sc_swflags, TIOCFLAG_CLOCAL))
669 			SET(t.c_cflag, CLOCAL);
670 		if (ISSET(sc->sc_swflags, TIOCFLAG_CRTSCTS))
671 			SET(t.c_cflag, CRTSCTS);
672 		if (ISSET(sc->sc_swflags, TIOCFLAG_MDMBUF))
673 			SET(t.c_cflag, MDMBUF);
674 		/* Make sure sciparam() will do something. */
675 		tp->t_ospeed = 0;
676 		(void) sciparam(tp, &t);
677 		tp->t_iflag = TTYDEF_IFLAG;
678 		tp->t_oflag = TTYDEF_OFLAG;
679 		tp->t_lflag = TTYDEF_LFLAG;
680 		ttychars(tp);
681 		ttsetwater(tp);
682 
683 		s2 = splserial();
684 
685 		/* Clear the input ring, and unblock. */
686 		sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
687 		sc->sc_rbavail = sci_rbuf_size;
688 		sci_iflush(sc);
689 		CLR(sc->sc_rx_flags, RX_ANY_BLOCK);
690 #if 0
691 /* XXX (msaitoh) */
692 		sci_hwiflow(sc);
693 #endif
694 
695 #ifdef SCI_DEBUG
696 		if (sci_debug)
697 			scistatus(sc, "sciopen  ");
698 #endif
699 
700 		splx(s2);
701 	}
702 
703 	splx(s);
704 
705 	error = ttyopen(tp, SCIDIALOUT(dev), ISSET(flag, O_NONBLOCK));
706 	if (error)
707 		goto bad;
708 
709 	error = (*tp->t_linesw->l_open)(dev, tp);
710 	if (error)
711 		goto bad;
712 
713 	return (0);
714 
715 bad:
716 
717 	return (error);
718 }
719 
720 int
721 sciclose(dev_t dev, int flag, int mode, struct lwp *l)
722 {
723 	struct sci_softc *sc = device_lookup_private(&sci_cd, SCIUNIT(dev));
724 	struct tty *tp = sc->sc_tty;
725 
726 	/* XXX This is for cons.c. */
727 	if (!ISSET(tp->t_state, TS_ISOPEN))
728 		return (0);
729 
730 	(*tp->t_linesw->l_close)(tp, flag);
731 	ttyclose(tp);
732 
733 	if (!device_is_active(sc->sc_dev))
734 		return (0);
735 
736 	return (0);
737 }
738 
739 int
740 sciread(dev_t dev, struct uio *uio, int flag)
741 {
742 	struct sci_softc *sc = device_lookup_private(&sci_cd, SCIUNIT(dev));
743 	struct tty *tp = sc->sc_tty;
744 
745 	return ((*tp->t_linesw->l_read)(tp, uio, flag));
746 }
747 
748 int
749 sciwrite(dev_t dev, struct uio *uio, int flag)
750 {
751 	struct sci_softc *sc = device_lookup_private(&sci_cd, SCIUNIT(dev));
752 	struct tty *tp = sc->sc_tty;
753 
754 	return ((*tp->t_linesw->l_write)(tp, uio, flag));
755 }
756 
757 int
758 scipoll(dev_t dev, int events, struct lwp *l)
759 {
760 	struct sci_softc *sc = device_lookup_private(&sci_cd, SCIUNIT(dev));
761 	struct tty *tp = sc->sc_tty;
762 
763 	return ((*tp->t_linesw->l_poll)(tp, events, l));
764 }
765 
766 struct tty *
767 scitty(dev_t dev)
768 {
769 	struct sci_softc *sc = device_lookup_private(&sci_cd, SCIUNIT(dev));
770 	struct tty *tp = sc->sc_tty;
771 
772 	return (tp);
773 }
774 
775 int
776 sciioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
777 {
778 	struct sci_softc *sc = device_lookup_private(&sci_cd, SCIUNIT(dev));
779 	struct tty *tp = sc->sc_tty;
780 	int error;
781 	int s;
782 
783 	if (!device_is_active(sc->sc_dev))
784 		return (EIO);
785 
786 	error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, l);
787 	if (error != EPASSTHROUGH)
788 		return (error);
789 
790 	error = ttioctl(tp, cmd, data, flag, l);
791 	if (error != EPASSTHROUGH)
792 		return (error);
793 
794 	error = 0;
795 
796 	s = splserial();
797 
798 	switch (cmd) {
799 	case TIOCSBRK:
800 		sci_break(sc, 1);
801 		break;
802 
803 	case TIOCCBRK:
804 		sci_break(sc, 0);
805 		break;
806 
807 	case TIOCGFLAGS:
808 		*(int *)data = sc->sc_swflags;
809 		break;
810 
811 	case TIOCSFLAGS:
812 		error = kauth_authorize_device_tty(l->l_cred,
813 		    KAUTH_DEVICE_TTY_PRIVSET, tp);
814 		if (error)
815 			break;
816 		sc->sc_swflags = *(int *)data;
817 		break;
818 
819 	default:
820 		error = EPASSTHROUGH;
821 		break;
822 	}
823 
824 	splx(s);
825 
826 	return (error);
827 }
828 
829 integrate void
830 sci_schedrx(struct sci_softc *sc)
831 {
832 
833 	sc->sc_rx_ready = 1;
834 
835 	/* Wake up the poller. */
836 	softint_schedule(sc->sc_si);
837 }
838 
839 void
840 sci_break(struct sci_softc *sc, int onoff)
841 {
842 
843 	if (onoff)
844 		SHREG_SCSSR &= ~SCSSR_TDRE;
845 	else
846 		SHREG_SCSSR |= SCSSR_TDRE;
847 
848 #if 0	/* XXX */
849 	if (!sc->sc_heldchange) {
850 		if (sc->sc_tx_busy) {
851 			sc->sc_heldtbc = sc->sc_tbc;
852 			sc->sc_tbc = 0;
853 			sc->sc_heldchange = 1;
854 		} else
855 			sci_loadchannelregs(sc);
856 	}
857 #endif
858 }
859 
860 /*
861  * Stop output, e.g., for ^S or output flush.
862  */
863 void
864 scistop(struct tty *tp, int flag)
865 {
866 	struct sci_softc *sc = device_lookup_private(&sci_cd, SCIUNIT(tp->t_dev));
867 	int s;
868 
869 	s = splserial();
870 	if (ISSET(tp->t_state, TS_BUSY)) {
871 		/* Stop transmitting at the next chunk. */
872 		sc->sc_tbc = 0;
873 		sc->sc_heldtbc = 0;
874 		if (!ISSET(tp->t_state, TS_TTSTOP))
875 			SET(tp->t_state, TS_FLUSH);
876 	}
877 	splx(s);
878 }
879 
880 void
881 scidiag(void *arg)
882 {
883 	struct sci_softc *sc = arg;
884 	int overflows, floods;
885 	int s;
886 
887 	s = splserial();
888 	overflows = sc->sc_overflows;
889 	sc->sc_overflows = 0;
890 	floods = sc->sc_floods;
891 	sc->sc_floods = 0;
892 	sc->sc_errors = 0;
893 	splx(s);
894 
895 	log(LOG_WARNING, "%s: %d silo overflow%s, %d ibuf flood%s\n",
896 	    device_xname(sc->sc_dev),
897 	    overflows, overflows == 1 ? "" : "s",
898 	    floods, floods == 1 ? "" : "s");
899 }
900 
901 integrate void
902 sci_rxsoft(struct sci_softc *sc, struct tty *tp)
903 {
904 	int (*rint)(int, struct tty *) = tp->t_linesw->l_rint;
905 	u_char *get, *end;
906 	u_int cc, scc;
907 	u_char ssr;
908 	int code;
909 	int s;
910 
911 	end = sc->sc_ebuf;
912 	get = sc->sc_rbget;
913 	scc = cc = sci_rbuf_size - sc->sc_rbavail;
914 
915 	if (cc == sci_rbuf_size) {
916 		sc->sc_floods++;
917 		if (sc->sc_errors++ == 0)
918 			callout_reset(&sc->sc_diag_ch, 60 * hz, scidiag, sc);
919 	}
920 
921 	while (cc) {
922 		code = get[0];
923 		ssr = get[1];
924 		if (ISSET(ssr, SCSSR_FER | SCSSR_PER)) {
925 			if (ISSET(ssr, SCSSR_FER))
926 				SET(code, TTY_FE);
927 			if (ISSET(ssr, SCSSR_PER))
928 				SET(code, TTY_PE);
929 		}
930 		if ((*rint)(code, tp) == -1) {
931 			/*
932 			 * The line discipline's buffer is out of space.
933 			 */
934 			if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
935 				/*
936 				 * We're either not using flow control, or the
937 				 * line discipline didn't tell us to block for
938 				 * some reason.  Either way, we have no way to
939 				 * know when there's more space available, so
940 				 * just drop the rest of the data.
941 				 */
942 				get += cc << 1;
943 				if (get >= end)
944 					get -= sci_rbuf_size << 1;
945 				cc = 0;
946 			} else {
947 				/*
948 				 * Don't schedule any more receive processing
949 				 * until the line discipline tells us there's
950 				 * space available (through scihwiflow()).
951 				 * Leave the rest of the data in the input
952 				 * buffer.
953 				 */
954 				SET(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
955 			}
956 			break;
957 		}
958 		get += 2;
959 		if (get >= end)
960 			get = sc->sc_rbuf;
961 		cc--;
962 	}
963 
964 	if (cc != scc) {
965 		sc->sc_rbget = get;
966 		s = splserial();
967 		cc = sc->sc_rbavail += scc - cc;
968 		/* Buffers should be ok again, release possible block. */
969 		if (cc >= sc->sc_r_lowat) {
970 			if (ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
971 				CLR(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
972 				SHREG_SCSCR |= SCSCR_RIE;
973 			}
974 #if 0
975 			if (ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED)) {
976 				CLR(sc->sc_rx_flags, RX_IBUF_BLOCKED);
977 				sci_hwiflow(sc);
978 			}
979 #endif
980 		}
981 		splx(s);
982 	}
983 }
984 
985 integrate void
986 sci_txsoft(struct sci_softc *sc, struct tty *tp)
987 {
988 
989 	CLR(tp->t_state, TS_BUSY);
990 	if (ISSET(tp->t_state, TS_FLUSH))
991 		CLR(tp->t_state, TS_FLUSH);
992 	else
993 		ndflush(&tp->t_outq, (int)(sc->sc_tba - tp->t_outq.c_cf));
994 	(*tp->t_linesw->l_start)(tp);
995 }
996 
997 integrate void
998 sci_stsoft(struct sci_softc *sc, struct tty *tp)
999 {
1000 #if 0
1001 /* XXX (msaitoh) */
1002 	u_char msr, delta;
1003 	int s;
1004 
1005 	s = splserial();
1006 	msr = sc->sc_msr;
1007 	delta = sc->sc_msr_delta;
1008 	sc->sc_msr_delta = 0;
1009 	splx(s);
1010 
1011 	if (ISSET(delta, sc->sc_msr_dcd)) {
1012 		/*
1013 		 * Inform the tty layer that carrier detect changed.
1014 		 */
1015 		(void) (*tp->t_linesw->l_modem)(tp, ISSET(msr, MSR_DCD));
1016 	}
1017 
1018 	if (ISSET(delta, sc->sc_msr_cts)) {
1019 		/* Block or unblock output according to flow control. */
1020 		if (ISSET(msr, sc->sc_msr_cts)) {
1021 			sc->sc_tx_stopped = 0;
1022 			(*tp->t_linesw->l_start)(tp);
1023 		} else {
1024 			sc->sc_tx_stopped = 1;
1025 		}
1026 	}
1027 
1028 #ifdef SCI_DEBUG
1029 	if (sci_debug)
1030 		scistatus(sc, "sci_stsoft");
1031 #endif
1032 #endif
1033 }
1034 
1035 void
1036 scisoft(void *arg)
1037 {
1038 	struct sci_softc *sc = arg;
1039 	struct tty *tp;
1040 
1041 	if (!device_is_active(sc->sc_dev))
1042 		return;
1043 
1044 	tp = sc->sc_tty;
1045 
1046 	if (sc->sc_rx_ready) {
1047 		sc->sc_rx_ready = 0;
1048 		sci_rxsoft(sc, tp);
1049 	}
1050 
1051 #if 0
1052 	if (sc->sc_st_check) {
1053 		sc->sc_st_check = 0;
1054 		sci_stsoft(sc, tp);
1055 	}
1056 #endif
1057 
1058 	if (sc->sc_tx_done) {
1059 		sc->sc_tx_done = 0;
1060 		sci_txsoft(sc, tp);
1061 	}
1062 }
1063 
1064 int
1065 sciintr(void *arg)
1066 {
1067 	struct sci_softc *sc = arg;
1068 	u_char *put, *end;
1069 	u_int cc;
1070 	u_short ssr;
1071 
1072 	if (!device_is_active(sc->sc_dev))
1073 		return (0);
1074 
1075 	end = sc->sc_ebuf;
1076 	put = sc->sc_rbput;
1077 	cc = sc->sc_rbavail;
1078 
1079 	do {
1080 		ssr = SHREG_SCSSR;
1081 		if (ISSET(ssr, SCSSR_FER)) {
1082 			SHREG_SCSSR &= ~(SCSSR_ORER | SCSSR_PER | SCSSR_FER);
1083 #if defined(DDB) || defined(KGDB)
1084 #ifdef SH4
1085 			if ((SHREG_SCSPTR & SCSPTR_SPB0DT) != 0) {
1086 #else
1087 			if ((SHREG_SCSPDR & SCSPDR_SCP0DT) != 0) {
1088 #endif
1089 #ifdef DDB
1090 				if (ISSET(sc->sc_hwflags, SCI_HW_CONSOLE)) {
1091 					console_debugger();
1092 				}
1093 #endif
1094 #ifdef KGDB
1095 				if (ISSET(sc->sc_hwflags, SCI_HW_KGDB)) {
1096 					kgdb_connect(1);
1097 				}
1098 #endif
1099 			}
1100 #endif /* DDB || KGDB */
1101 		}
1102 		if ((SHREG_SCSSR & SCSSR_RDRF) != 0) {
1103 			if (cc > 0) {
1104 				put[0] = SHREG_SCRDR;
1105 				put[1] = SHREG_SCSSR & 0x00ff;
1106 
1107 				put += 2;
1108 				if (put >= end)
1109 					put = sc->sc_rbuf;
1110 				cc--;
1111 			}
1112 
1113 			SHREG_SCSSR &= ~(SCSSR_ORER | SCSSR_FER | SCSSR_PER |
1114 			    SCSSR_RDRF);
1115 
1116 				/*
1117 				 * Current string of incoming characters ended because
1118 				 * no more data was available or we ran out of space.
1119 				 * Schedule a receive event if any data was received.
1120 				 * If we're out of space, turn off receive interrupts.
1121 				 */
1122 			sc->sc_rbput = put;
1123 			sc->sc_rbavail = cc;
1124 			if (!ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED))
1125 				sc->sc_rx_ready = 1;
1126 
1127 				/*
1128 				 * See if we are in danger of overflowing a buffer. If
1129 				 * so, use hardware flow control to ease the pressure.
1130 				 */
1131 			if (!ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED) &&
1132 			    cc < sc->sc_r_hiwat) {
1133 				SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
1134 #if 0
1135 				sci_hwiflow(sc);
1136 #endif
1137 			}
1138 
1139 				/*
1140 				 * If we're out of space, disable receive interrupts
1141 				 * until the queue has drained a bit.
1142 				 */
1143 			if (!cc) {
1144 				SET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
1145 				SHREG_SCSCR &= ~SCSCR_RIE;
1146 			}
1147 		} else {
1148 			if (SHREG_SCSSR & SCSSR_RDRF) {
1149 				SHREG_SCSCR &= ~(SCSCR_TIE | SCSCR_RIE);
1150 				delay(10);
1151 				SHREG_SCSCR |= SCSCR_TIE | SCSCR_RIE;
1152 				continue;
1153 			}
1154 		}
1155 	} while (SHREG_SCSSR & SCSSR_RDRF);
1156 
1157 #if 0
1158 	msr = bus_space_read_1(iot, ioh, sci_msr);
1159 	delta = msr ^ sc->sc_msr;
1160 	sc->sc_msr = msr;
1161 	if (ISSET(delta, sc->sc_msr_mask)) {
1162 		SET(sc->sc_msr_delta, delta);
1163 
1164 		/*
1165 		 * Pulse-per-second clock signal on edge of DCD?
1166 		 */
1167 		if (ISSET(delta, sc->sc_ppsmask)) {
1168 			struct timeval tv;
1169 			if (ISSET(msr, sc->sc_ppsmask) ==
1170 			    sc->sc_ppsassert) {
1171 				/* XXX nanotime() */
1172 				microtime(&tv);
1173 				TIMEVAL_TO_TIMESPEC(&tv,
1174 						    &sc->ppsinfo.assert_timestamp);
1175 				if (sc->ppsparam.mode & PPS_OFFSETASSERT) {
1176 					timespecadd(&sc->ppsinfo.assert_timestamp,
1177 						    &sc->ppsparam.assert_offset,
1178 						    &sc->ppsinfo.assert_timestamp);
1179 					TIMESPEC_TO_TIMEVAL(&tv, &sc->ppsinfo.assert_timestamp);
1180 				}
1181 
1182 #ifdef PPS_SYNC
1183 				if (sc->ppsparam.mode & PPS_HARDPPSONASSERT)
1184 					hardpps(&tv, tv.tv_usec);
1185 #endif
1186 				sc->ppsinfo.assert_sequence++;
1187 				sc->ppsinfo.current_mode =
1188 					sc->ppsparam.mode;
1189 
1190 			} else if (ISSET(msr, sc->sc_ppsmask) ==
1191 				   sc->sc_ppsclear) {
1192 				/* XXX nanotime() */
1193 				microtime(&tv);
1194 				TIMEVAL_TO_TIMESPEC(&tv,
1195 						    &sc->ppsinfo.clear_timestamp);
1196 				if (sc->ppsparam.mode & PPS_OFFSETCLEAR) {
1197 					timespecadd(&sc->ppsinfo.clear_timestamp,
1198 						    &sc->ppsparam.clear_offset,
1199 						    &sc->ppsinfo.clear_timestamp);
1200 					TIMESPEC_TO_TIMEVAL(&tv, &sc->ppsinfo.clear_timestamp);
1201 				}
1202 
1203 #ifdef PPS_SYNC
1204 				if (sc->ppsparam.mode & PPS_HARDPPSONCLEAR)
1205 					hardpps(&tv, tv.tv_usec);
1206 #endif
1207 				sc->ppsinfo.clear_sequence++;
1208 				sc->ppsinfo.current_mode =
1209 					sc->ppsparam.mode;
1210 			}
1211 		}
1212 
1213 		/*
1214 		 * Stop output immediately if we lose the output
1215 		 * flow control signal or carrier detect.
1216 		 */
1217 		if (ISSET(~msr, sc->sc_msr_mask)) {
1218 			sc->sc_tbc = 0;
1219 			sc->sc_heldtbc = 0;
1220 #ifdef SCI_DEBUG
1221 			if (sci_debug)
1222 				scistatus(sc, "sciintr  ");
1223 #endif
1224 		}
1225 
1226 		sc->sc_st_check = 1;
1227 	}
1228 #endif
1229 
1230 	/*
1231 	 * Done handling any receive interrupts. See if data can be
1232 	 * transmitted as well. Schedule tx done event if no data left
1233 	 * and tty was marked busy.
1234 	 */
1235 	if ((SHREG_SCSSR & SCSSR_TDRE) != 0) {
1236 		/*
1237 		 * If we've delayed a parameter change, do it now, and restart
1238 		 * output.
1239 		 */
1240 		if (sc->sc_heldchange) {
1241 			sc->sc_heldchange = 0;
1242 			sc->sc_tbc = sc->sc_heldtbc;
1243 			sc->sc_heldtbc = 0;
1244 		}
1245 
1246 		/* Output the next chunk of the contiguous buffer, if any. */
1247 		if (sc->sc_tbc > 0) {
1248 			sci_putc(*(sc->sc_tba));
1249 			sc->sc_tba++;
1250 			sc->sc_tbc--;
1251 		} else {
1252 			/* Disable transmit completion interrupts if necessary. */
1253 #if 0
1254 			if (ISSET(sc->sc_ier, IER_ETXRDY))
1255 #endif
1256 				SHREG_SCSCR &= ~SCSCR_TIE;
1257 
1258 			if (sc->sc_tx_busy) {
1259 				sc->sc_tx_busy = 0;
1260 				sc->sc_tx_done = 1;
1261 			}
1262 		}
1263 	}
1264 
1265 	/* Wake up the poller. */
1266 	softint_schedule(sc->sc_si);
1267 
1268 #ifdef RND_SCI
1269 	rnd_add_uint32(&sc->rnd_source, iir | lsr);
1270 #endif
1271 
1272 	return (1);
1273 }
1274 
1275 void
1276 scicnprobe(struct consdev *cp)
1277 {
1278 	int maj;
1279 
1280 	/* locate the major number */
1281 	maj = cdevsw_lookup_major(&sci_cdevsw);
1282 
1283 	/* Initialize required fields. */
1284 	cp->cn_dev = makedev(maj, 0);
1285 #ifdef SCICONSOLE
1286 	cp->cn_pri = CN_REMOTE;
1287 #else
1288 	cp->cn_pri = CN_NORMAL;
1289 #endif
1290 }
1291 
1292 void
1293 scicninit(struct consdev *cp)
1294 {
1295 
1296 	InitializeSci(scicn_speed);
1297 	sciisconsole = 1;
1298 }
1299 
1300 int
1301 scicngetc(dev_t dev)
1302 {
1303 	int c;
1304 	int s;
1305 
1306 	s = splserial();
1307 	c = sci_getc();
1308 	splx(s);
1309 
1310 	return (c);
1311 }
1312 
1313 void
1314 scicnputc(dev_t dev, int c)
1315 {
1316 	int s;
1317 
1318 	s = splserial();
1319 	sci_putc((u_char)c);
1320 	splx(s);
1321 }
1322