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ms.c revision 1.17
      1 /*	$NetBSD: ms.c,v 1.17 2003/07/15 01:44:52 lukem Exp $ */
      2 
      3 /*
      4  * Copyright (c) 1992, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * This software was developed by the Computer Systems Engineering group
      8  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
      9  * contributed to Berkeley.
     10  *
     11  * All advertising materials mentioning features or use of this software
     12  * must display the following acknowledgement:
     13  *	This product includes software developed by the University of
     14  *	California, Lawrence Berkeley Laboratory.
     15  *
     16  * Redistribution and use in source and binary forms, with or without
     17  * modification, are permitted provided that the following conditions
     18  * are met:
     19  * 1. Redistributions of source code must retain the above copyright
     20  *    notice, this list of conditions and the following disclaimer.
     21  * 2. Redistributions in binary form must reproduce the above copyright
     22  *    notice, this list of conditions and the following disclaimer in the
     23  *    documentation and/or other materials provided with the distribution.
     24  * 3. All advertising materials mentioning features or use of this software
     25  *    must display the following acknowledgement:
     26  *	This product includes software developed by the University of
     27  *	California, Berkeley and its contributors.
     28  * 4. Neither the name of the University nor the names of its contributors
     29  *    may be used to endorse or promote products derived from this software
     30  *    without specific prior written permission.
     31  *
     32  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     33  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     34  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     35  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     36  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     37  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     38  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     39  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     40  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     41  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     42  * SUCH DAMAGE.
     43  *
     44  *	@(#)ms.c	8.1 (Berkeley) 6/11/93
     45  */
     46 
     47 /*
     48  * X68k mouse driver.
     49  */
     50 
     51 #include <sys/cdefs.h>
     52 __KERNEL_RCSID(0, "$NetBSD: ms.c,v 1.17 2003/07/15 01:44:52 lukem Exp $");
     53 
     54 #include <sys/param.h>
     55 #include <sys/conf.h>
     56 #include <sys/ioctl.h>
     57 #include <sys/kernel.h>
     58 #include <sys/proc.h>
     59 #include <sys/syslog.h>
     60 #include <sys/systm.h>
     61 #include <sys/tty.h>
     62 #include <sys/device.h>
     63 #include <sys/signalvar.h>
     64 
     65 #include <dev/ic/z8530reg.h>
     66 #include <machine/z8530var.h>
     67 
     68 #include <arch/x68k/dev/event_var.h>
     69 #include <machine/vuid_event.h>
     70 #include <arch/x68k/dev/mfp.h>
     71 
     72 #include "locators.h"
     73 
     74 /*
     75  * How many input characters we can buffer.
     76  * The port-specific var.h may override this.
     77  * Note: must be a power of two!
     78  */
     79 #define	MS_RX_RING_SIZE	256
     80 #define MS_RX_RING_MASK (MS_RX_RING_SIZE-1)
     81 /*
     82  * Output buffer.  Only need a few chars.
     83  */
     84 #define	MS_TX_RING_SIZE	16
     85 #define MS_TX_RING_MASK (MS_TX_RING_SIZE-1)
     86 /*
     87  * Mouse serial line is fixed at 4800 bps.
     88  */
     89 #define MS_BPS 4800
     90 
     91 /*
     92  * Mouse state.  A SHARP X1/X680x0 mouse is a fairly simple device,
     93  * producing three-byte blobs of the form:
     94  *
     95  *	b dx dy
     96  *
     97  * where b is the button state, encoded as 0x80|(buttons)---there are
     98  * two buttons (2=left, 1=right)---and dx,dy are X and Y delta values.
     99  *
    100  * It needs a trigger for the transmission.  When zs RTS negated, the
    101  * mouse begins the sequence.  RTS assertion has no effect.
    102  */
    103 struct ms_softc {
    104 	struct	device ms_dev;		/* required first: base device */
    105 	struct	zs_chanstate *ms_cs;
    106 
    107 	struct callout ms_modem_ch;
    108 
    109 	/* Flags to communicate with ms_softintr() */
    110 	volatile int ms_intr_flags;
    111 #define	INTR_RX_OVERRUN 1
    112 #define INTR_TX_EMPTY   2
    113 #define INTR_ST_CHECK   4
    114 
    115 	/*
    116 	 * The receive ring buffer.
    117 	 */
    118 	u_int	ms_rbget;	/* ring buffer `get' index */
    119 	volatile u_int	ms_rbput;	/* ring buffer `put' index */
    120 	u_short	ms_rbuf[MS_RX_RING_SIZE]; /* rr1, data pairs */
    121 
    122 	/*
    123 	 * State of input translator
    124 	 */
    125 	short	ms_byteno;		/* input byte number, for decode */
    126 	char	ms_mb;			/* mouse button state */
    127 	char	ms_ub;			/* user button state */
    128 	int	ms_dx;			/* delta-x */
    129 	int	ms_dy;			/* delta-y */
    130 	int	ms_rts;			/* MSCTRL */
    131 	int	ms_nodata;
    132 
    133 	/*
    134 	 * State of upper interface.
    135 	 */
    136 	volatile int ms_ready;		/* event queue is ready */
    137 	struct	evvar ms_events;	/* event queue state */
    138 } ms_softc;
    139 
    140 static int ms_match __P((struct device*, struct cfdata*, void*));
    141 static void ms_attach __P((struct device*, struct device*, void*));
    142 static void ms_trigger __P((struct zs_chanstate*, int));
    143 void ms_modem __P((void *));
    144 
    145 CFATTACH_DECL(ms, sizeof(struct ms_softc),
    146     ms_match, ms_attach, NULL, NULL);
    147 
    148 extern struct zsops zsops_ms;
    149 extern struct cfdriver ms_cd;
    150 
    151 dev_type_open(msopen);
    152 dev_type_close(msclose);
    153 dev_type_read(msread);
    154 dev_type_ioctl(msioctl);
    155 dev_type_poll(mspoll);
    156 dev_type_kqfilter(mskqfilter);
    157 
    158 const struct cdevsw ms_cdevsw ={
    159 	msopen, msclose, msread, nowrite, msioctl,
    160 	nostop, notty, mspoll, nommap, mskqfilter,
    161 };
    162 
    163 /*
    164  * ms_match: how is this zs channel configured?
    165  */
    166 int
    167 ms_match(parent, cf, aux)
    168 	struct device *parent;
    169 	struct cfdata *cf;
    170 	void   *aux;
    171 {
    172 	struct zsc_attach_args *args = aux;
    173 	struct zsc_softc *zsc = (void*) parent;
    174 
    175 	/* Exact match required for the mouse. */
    176 	if (cf->cf_loc[ZSCCF_CHANNEL] != args->channel)
    177 		return 0;
    178 	if (args->channel != 1)
    179 		return 0;
    180 	if (&zsc->zsc_addr->zs_chan_b != (struct zschan *) ZSMS_PHYSADDR)
    181 		return 0;
    182 
    183 	return 2;
    184 }
    185 
    186 void
    187 ms_attach(parent, self, aux)
    188 	struct device *parent, *self;
    189 	void   *aux;
    190 
    191 {
    192 	struct zsc_softc *zsc = (void *) parent;
    193 	struct ms_softc *ms = (void *) self;
    194 	struct zs_chanstate *cs;
    195 	struct cfdata *cf;
    196 	int reset, s;
    197 
    198 	callout_init(&ms->ms_modem_ch);
    199 
    200 	cf = ms->ms_dev.dv_cfdata;
    201 	cs = zsc->zsc_cs[1];
    202 	cs->cs_private = ms;
    203 	cs->cs_ops = &zsops_ms;
    204 	ms->ms_cs = cs;
    205 
    206 	/* Initialize the speed, etc. */
    207 	s = splzs();
    208 	/* May need reset... */
    209 	reset = ZSWR9_B_RESET;
    210 	zs_write_reg(cs, 9, reset);
    211 	/* We don't care about status or tx interrupts. */
    212 	cs->cs_preg[1] = ZSWR1_RIE;
    213 	cs->cs_preg[4] = ZSWR4_CLK_X16 | ZSWR4_TWOSB;
    214 	(void) zs_set_speed(cs, MS_BPS);
    215 	zs_loadchannelregs(cs);
    216 	splx(s);
    217 
    218 	/* Initialize translator. */
    219 	ms->ms_ready = 0;
    220 
    221 	printf ("\n");
    222 }
    223 
    224 /****************************************************************
    225  *  Entry points for /dev/mouse
    226  *  (open,close,read,write,...)
    227  ****************************************************************/
    228 
    229 int
    230 msopen(dev, flags, mode, p)
    231 	dev_t dev;
    232 	int flags, mode;
    233 	struct proc *p;
    234 {
    235 	struct ms_softc *ms;
    236 	int unit;
    237 
    238 	unit = minor(dev);
    239 	if (unit >= ms_cd.cd_ndevs)
    240 		return (ENXIO);
    241 	ms = ms_cd.cd_devs[unit];
    242 	if (ms == NULL)
    243 		return (ENXIO);
    244 
    245 	/* This is an exclusive open device. */
    246 	if (ms->ms_events.ev_io)
    247 		return (EBUSY);
    248 	ms->ms_events.ev_io = p;
    249 	ev_init(&ms->ms_events);	/* may cause sleep */
    250 
    251 	ms->ms_ready = 1;		/* start accepting events */
    252 	ms->ms_rts = 1;
    253 	ms->ms_byteno = -1;
    254 	ms->ms_nodata = 0;
    255 
    256 	/* start sequencer */
    257 	ms_modem(ms);
    258 
    259 	return (0);
    260 }
    261 
    262 int
    263 msclose(dev, flags, mode, p)
    264 	dev_t dev;
    265 	int flags, mode;
    266 	struct proc *p;
    267 {
    268 	struct ms_softc *ms;
    269 
    270 	ms = ms_cd.cd_devs[minor(dev)];
    271 	ms->ms_ready = 0;		/* stop accepting events */
    272 	callout_stop(&ms->ms_modem_ch);
    273 	ev_fini(&ms->ms_events);
    274 
    275 	ms->ms_events.ev_io = NULL;
    276 	return (0);
    277 }
    278 
    279 int
    280 msread(dev, uio, flags)
    281 	dev_t dev;
    282 	struct uio *uio;
    283 	int flags;
    284 {
    285 	struct ms_softc *ms;
    286 
    287 	ms = ms_cd.cd_devs[minor(dev)];
    288 	return (ev_read(&ms->ms_events, uio, flags));
    289 }
    290 
    291 int
    292 msioctl(dev, cmd, data, flag, p)
    293 	dev_t dev;
    294 	u_long cmd;
    295 	register caddr_t data;
    296 	int flag;
    297 	struct proc *p;
    298 {
    299 	struct ms_softc *ms;
    300 
    301 	ms = ms_cd.cd_devs[minor(dev)];
    302 
    303 	switch (cmd) {
    304 
    305 	case FIONBIO:		/* we will remove this someday (soon???) */
    306 		return (0);
    307 
    308 	case FIOASYNC:
    309 		ms->ms_events.ev_async = *(int *)data != 0;
    310 		return (0);
    311 
    312 	case TIOCSPGRP:
    313 		if (*(int *)data != ms->ms_events.ev_io->p_pgid)
    314 			return (EPERM);
    315 		return (0);
    316 
    317 	case VUIDGFORMAT:
    318 		/* we only do firm_events */
    319 		*(int *)data = VUID_FIRM_EVENT;
    320 		return (0);
    321 
    322 	case VUIDSFORMAT:
    323 		if (*(int *)data != VUID_FIRM_EVENT)
    324 			return (EINVAL);
    325 		return (0);
    326 	}
    327 	return (ENOTTY);
    328 }
    329 
    330 int
    331 mspoll(dev, events, p)
    332 	dev_t dev;
    333 	int events;
    334 	struct proc *p;
    335 {
    336 	struct ms_softc *ms;
    337 
    338 	ms = ms_cd.cd_devs[minor(dev)];
    339 	return (ev_poll(&ms->ms_events, events, p));
    340 }
    341 
    342 int
    343 mskqfilter(dev_t dev, struct knote *kn)
    344 {
    345 	struct ms_softc *ms;
    346 
    347 	ms = ms_cd.cd_devs[minor(dev)];
    348 	return (ev_kqfilter(&ms->ms_events, kn));
    349 }
    350 
    351 /****************************************************************
    352  * Middle layer (translator)
    353  ****************************************************************/
    354 
    355 static void ms_input __P((struct ms_softc *, int c));
    356 
    357 
    358 /*
    359  * Called by our ms_softint() routine on input.
    360  */
    361 static void
    362 ms_input(ms, c)
    363 	register struct ms_softc *ms;
    364 	register int c;
    365 {
    366 	register struct firm_event *fe;
    367 	register int mb, ub, d, get, put, any;
    368 	static const char to_one[] = { 1, 2, 3 };
    369 	static const int to_id[] = { MS_LEFT, MS_RIGHT, MS_MIDDLE };
    370 
    371 	/*
    372 	 * Discard input if not ready.  Drop sync on parity or framing
    373 	 * error; gain sync on button byte.
    374 	 */
    375 	if (ms->ms_ready == 0)
    376 		return;
    377 
    378 	ms->ms_nodata = 0;
    379 	/*
    380 	 * Run the decode loop, adding to the current information.
    381 	 * We add, rather than replace, deltas, so that if the event queue
    382 	 * fills, we accumulate data for when it opens up again.
    383 	 */
    384 	switch (ms->ms_byteno) {
    385 
    386 	case -1:
    387 		return;
    388 
    389 	case 0:
    390 		/* buttons */
    391 		ms->ms_byteno = 1;
    392 		ms->ms_mb = c & 0x3;
    393 		return;
    394 
    395 	case 1:
    396 		/* delta-x */
    397 		ms->ms_byteno = 2;
    398 		ms->ms_dx += (char)c;
    399 		return;
    400 
    401 	case 2:
    402 		/* delta-y */
    403 		ms->ms_byteno = -1;
    404 		ms->ms_dy += (char)c;
    405 		break;
    406 
    407 	default:
    408 		panic("ms_input");
    409 		/* NOTREACHED */
    410 	}
    411 
    412 	/*
    413 	 * We have at least one event (mouse button, delta-X, or
    414 	 * delta-Y; possibly all three, and possibly three separate
    415 	 * button events).  Deliver these events until we are out
    416 	 * of changes or out of room.  As events get delivered,
    417 	 * mark them `unchanged'.
    418 	 */
    419 	any = 0;
    420 	get = ms->ms_events.ev_get;
    421 	put = ms->ms_events.ev_put;
    422 	fe = &ms->ms_events.ev_q[put];
    423 
    424 	/* NEXT prepares to put the next event, backing off if necessary */
    425 #define	NEXT \
    426 	if ((++put) % EV_QSIZE == get) { \
    427 		put--; \
    428 		goto out; \
    429 	}
    430 	/* ADVANCE completes the `put' of the event */
    431 #define	ADVANCE \
    432 	fe++; \
    433 	if (put >= EV_QSIZE) { \
    434 		put = 0; \
    435 		fe = &ms->ms_events.ev_q[0]; \
    436 	} \
    437 
    438 	mb = ms->ms_mb;
    439 	ub = ms->ms_ub;
    440 	while ((d = mb ^ ub) != 0) {
    441 		/*
    442 		 * Mouse button change.  Convert up to three changes
    443 		 * to the `first' change, and drop it into the event queue.
    444 		 */
    445 		NEXT;
    446 		d = to_one[d - 1];		/* from 1..7 to {1,2,4} */
    447 		fe->id = to_id[d - 1];		/* from {1,2,4} to ID */
    448 		fe->value = mb & d ? VKEY_DOWN : VKEY_UP;
    449 		fe->time = time;
    450 		ADVANCE;
    451 		ub ^= d;
    452 		any++;
    453 	}
    454 	if (ms->ms_dx) {
    455 		NEXT;
    456 		fe->id = LOC_X_DELTA;
    457 		fe->value = ms->ms_dx;
    458 		fe->time = time;
    459 		ADVANCE;
    460 		ms->ms_dx = 0;
    461 		any++;
    462 	}
    463 	if (ms->ms_dy) {
    464 		NEXT;
    465 		fe->id = LOC_Y_DELTA;
    466 		fe->value = -ms->ms_dy;	/* XXX? */
    467 		fe->time = time;
    468 		ADVANCE;
    469 		ms->ms_dy = 0;
    470 		any++;
    471 	}
    472 out:
    473 	if (any) {
    474 		ms->ms_ub = ub;
    475 		ms->ms_events.ev_put = put;
    476 		EV_WAKEUP(&ms->ms_events);
    477 	}
    478 }
    479 
    480 /****************************************************************
    481  * Interface to the lower layer (zscc)
    482  ****************************************************************/
    483 
    484 static void ms_rxint __P((struct zs_chanstate *));
    485 static void ms_stint __P((struct zs_chanstate *, int));
    486 static void ms_txint __P((struct zs_chanstate *));
    487 static void ms_softint __P((struct zs_chanstate *));
    488 
    489 static void
    490 ms_rxint(cs)
    491 	register struct zs_chanstate *cs;
    492 {
    493 	register struct ms_softc *ms;
    494 	register int put, put_next;
    495 	register u_char c, rr1;
    496 
    497 	ms = cs->cs_private;
    498 	put = ms->ms_rbput;
    499 
    500 	/*
    501 	 * First read the status, because reading the received char
    502 	 * destroys the status of this char.
    503 	 */
    504 	rr1 = zs_read_reg(cs, 1);
    505 	c = zs_read_data(cs);
    506 
    507 	if (rr1 & (ZSRR1_FE | ZSRR1_DO | ZSRR1_PE)) {
    508 		/* Clear the receive error. */
    509 		zs_write_csr(cs, ZSWR0_RESET_ERRORS);
    510 	}
    511 
    512 	ms->ms_rbuf[put] = (c << 8) | rr1;
    513 	put_next = (put + 1) & MS_RX_RING_MASK;
    514 
    515 	/* Would overrun if increment makes (put==get). */
    516 	if (put_next == ms->ms_rbget) {
    517 		ms->ms_intr_flags |= INTR_RX_OVERRUN;
    518 	} else {
    519 		/* OK, really increment. */
    520 		put = put_next;
    521 	}
    522 
    523 	/* Done reading. */
    524 	ms->ms_rbput = put;
    525 
    526 	/* Ask for softint() call. */
    527 	cs->cs_softreq = 1;
    528 }
    529 
    530 
    531 static void
    532 ms_txint(cs)
    533 	register struct zs_chanstate *cs;
    534 {
    535 	register struct ms_softc *ms;
    536 
    537 	ms = cs->cs_private;
    538 	zs_write_csr(cs, ZSWR0_RESET_TXINT);
    539 	ms->ms_intr_flags |= INTR_TX_EMPTY;
    540 	/* Ask for softint() call. */
    541 	cs->cs_softreq = 1;
    542 }
    543 
    544 
    545 static void
    546 ms_stint(cs, force)
    547 	register struct zs_chanstate *cs;
    548 	int force;
    549 {
    550 	register struct ms_softc *ms;
    551 	register int rr0;
    552 
    553 	ms = cs->cs_private;
    554 
    555 	rr0 = zs_read_csr(cs);
    556 	zs_write_csr(cs, ZSWR0_RESET_STATUS);
    557 
    558 	/*
    559 	 * We have to accumulate status line changes here.
    560 	 * Otherwise, if we get multiple status interrupts
    561 	 * before the softint runs, we could fail to notice
    562 	 * some status line changes in the softint routine.
    563 	 * Fix from Bill Studenmund, October 1996.
    564 	 */
    565 	cs->cs_rr0_delta |= (cs->cs_rr0 ^ rr0);
    566 	cs->cs_rr0 = rr0;
    567 	ms->ms_intr_flags |= INTR_ST_CHECK;
    568 
    569 	/* Ask for softint() call. */
    570 	cs->cs_softreq = 1;
    571 }
    572 
    573 
    574 static void
    575 ms_softint(cs)
    576 	struct zs_chanstate *cs;
    577 {
    578 	register struct ms_softc *ms;
    579 	register int get, c, s;
    580 	int intr_flags;
    581 	register u_short ring_data;
    582 
    583 	ms = cs->cs_private;
    584 
    585 	/* Atomically get and clear flags. */
    586 	s = splzs();
    587 	intr_flags = ms->ms_intr_flags;
    588 	ms->ms_intr_flags = 0;
    589 
    590 	/* Now lower to spltty for the rest. */
    591 	(void) spltty();
    592 
    593 	/*
    594 	 * Copy data from the receive ring to the event layer.
    595 	 */
    596 	get = ms->ms_rbget;
    597 	while (get != ms->ms_rbput) {
    598 		ring_data = ms->ms_rbuf[get];
    599 		get = (get + 1) & MS_RX_RING_MASK;
    600 
    601 		/* low byte of ring_data is rr1 */
    602 		c = (ring_data >> 8) & 0xff;
    603 
    604 		if (ring_data & ZSRR1_DO)
    605 			intr_flags |= INTR_RX_OVERRUN;
    606 		if (ring_data & (ZSRR1_FE | ZSRR1_PE)) {
    607 			log(LOG_ERR, "%s: input error (0x%x)\n",
    608 				ms->ms_dev.dv_xname, ring_data);
    609 			c = -1;	/* signal input error */
    610 		}
    611 
    612 		/* Pass this up to the "middle" layer. */
    613 		ms_input(ms, c);
    614 	}
    615 	if (intr_flags & INTR_RX_OVERRUN) {
    616 		log(LOG_ERR, "%s: input overrun\n",
    617 		    ms->ms_dev.dv_xname);
    618 	}
    619 	ms->ms_rbget = get;
    620 
    621 	if (intr_flags & INTR_TX_EMPTY) {
    622 		/*
    623 		 * Transmit done.  (Not expected.)
    624 		 */
    625 		log(LOG_ERR, "%s: transmit interrupt?\n",
    626 		    ms->ms_dev.dv_xname);
    627 	}
    628 
    629 	if (intr_flags & INTR_ST_CHECK) {
    630 		/*
    631 		 * Status line change.  (Not expected.)
    632 		 */
    633 		log(LOG_ERR, "%s: status interrupt?\n",
    634 		    ms->ms_dev.dv_xname);
    635 		cs->cs_rr0_delta = 0;
    636 	}
    637 
    638 	splx(s);
    639 }
    640 
    641 struct zsops zsops_ms = {
    642 	ms_rxint,	/* receive char available */
    643 	ms_stint,	/* external/status */
    644 	ms_txint,	/* xmit buffer empty */
    645 	ms_softint,	/* process software interrupt */
    646 };
    647 
    648 
    649 static void
    650 ms_trigger (cs, onoff)
    651 	struct zs_chanstate *cs;
    652 	int onoff;
    653 {
    654 	/* for front connected one */
    655 	if (onoff)
    656 		cs->cs_preg[5] |= ZSWR5_RTS;
    657 	else
    658 		cs->cs_preg[5] &= ~ZSWR5_RTS;
    659 	cs->cs_creg[5] = cs->cs_preg[5];
    660 	zs_write_reg(cs, 5, cs->cs_preg[5]);
    661 
    662 	/* for keyborad connected one */
    663 	mfp_send_usart (onoff | 0x40);
    664 }
    665 
    666 /*
    667  * mouse timer interrupt.
    668  * called after system tick interrupt is done.
    669  */
    670 void
    671 ms_modem(arg)
    672 	void *arg;
    673 {
    674 	struct ms_softc *ms = arg;
    675 	int s;
    676 
    677 	if (!ms->ms_ready)
    678 		return;
    679 
    680 	s = splzs();
    681 
    682 	if (ms->ms_nodata++ > 250) { /* XXX */
    683 		log(LOG_ERR, "%s: no data for 5 secs. resetting.\n",
    684 		    ms->ms_dev.dv_xname);
    685 		ms->ms_byteno = -1;
    686 		ms->ms_nodata = 0;
    687 		ms->ms_rts = 0;
    688 	}
    689 
    690 	if (ms->ms_rts) {
    691 		if (ms->ms_byteno == -1) {
    692 			/* start next sequence */
    693 			ms->ms_rts = 0;
    694 			ms_trigger(ms->ms_cs, ms->ms_rts);
    695 			ms->ms_byteno = 0;
    696 		}
    697 	} else {
    698 		ms->ms_rts = 1;
    699 		ms_trigger(ms->ms_cs, ms->ms_rts);
    700 	}
    701 
    702 	(void) splx(s);
    703 	callout_reset(&ms->ms_modem_ch, 2, ms_modem, ms);
    704 }
    705