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ms.c revision 1.33
      1 /*	$NetBSD: ms.c,v 1.33 2014/03/26 08:17:59 christos 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. Neither the name of the University nor the names of its contributors
     25  *    may be used to endorse or promote products derived from this software
     26  *    without specific prior written permission.
     27  *
     28  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     29  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     30  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     31  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     32  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     33  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     34  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     35  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     36  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     37  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     38  * SUCH DAMAGE.
     39  *
     40  *	@(#)ms.c	8.1 (Berkeley) 6/11/93
     41  */
     42 
     43 /*
     44  * X68k mouse driver.
     45  */
     46 
     47 #include <sys/cdefs.h>
     48 __KERNEL_RCSID(0, "$NetBSD: ms.c,v 1.33 2014/03/26 08:17:59 christos Exp $");
     49 
     50 #include <sys/param.h>
     51 #include <sys/conf.h>
     52 #include <sys/ioctl.h>
     53 #include <sys/kernel.h>
     54 #include <sys/proc.h>
     55 #include <sys/syslog.h>
     56 #include <sys/systm.h>
     57 #include <sys/tty.h>
     58 #include <sys/device.h>
     59 #include <sys/signalvar.h>
     60 #include <sys/mutex.h>
     61 
     62 #include <dev/ic/z8530reg.h>
     63 #include <machine/z8530var.h>
     64 
     65 #include <arch/x68k/dev/event_var.h>
     66 #include <machine/vuid_event.h>
     67 #include <arch/x68k/dev/mfp.h>
     68 
     69 #include "ioconf.h"
     70 #include "locators.h"
     71 
     72 /*
     73  * How many input characters we can buffer.
     74  * The port-specific var.h may override this.
     75  * Note: must be a power of two!
     76  */
     77 #define	MS_RX_RING_SIZE	256
     78 #define MS_RX_RING_MASK (MS_RX_RING_SIZE-1)
     79 /*
     80  * Output buffer.  Only need a few chars.
     81  */
     82 #define	MS_TX_RING_SIZE	16
     83 #define MS_TX_RING_MASK (MS_TX_RING_SIZE-1)
     84 /*
     85  * Mouse serial line is fixed at 4800 bps.
     86  */
     87 #define MS_BPS 4800
     88 
     89 /*
     90  * Mouse state.  A SHARP X1/X680x0 mouse is a fairly simple device,
     91  * producing three-byte blobs of the form:
     92  *
     93  *	b dx dy
     94  *
     95  * where b is the button state, encoded as 0x80|(buttons)---there are
     96  * two buttons (2=left, 1=right)---and dx,dy are X and Y delta values.
     97  *
     98  * It needs a trigger for the transmission.  When zs RTS negated, the
     99  * mouse begins the sequence.  RTS assertion has no effect.
    100  */
    101 struct ms_softc {
    102 	device_t ms_dev;		/* required first: base device */
    103 	struct	zs_chanstate *ms_cs;
    104 
    105 	struct callout ms_modem_ch;
    106 
    107 	/* Flags to communicate with ms_softintr() */
    108 	volatile int ms_intr_flags;
    109 #define	INTR_RX_OVERRUN 1
    110 #define INTR_TX_EMPTY   2
    111 #define INTR_ST_CHECK   4
    112 
    113 	/*
    114 	 * The receive ring buffer.
    115 	 */
    116 	u_int	ms_rbget;	/* ring buffer `get' index */
    117 	volatile u_int	ms_rbput;	/* ring buffer `put' index */
    118 	u_short	ms_rbuf[MS_RX_RING_SIZE]; /* rr1, data pairs */
    119 
    120 	/*
    121 	 * State of input translator
    122 	 */
    123 	short	ms_byteno;		/* input byte number, for decode */
    124 	char	ms_mb;			/* mouse button state */
    125 	char	ms_ub;			/* user button state */
    126 	int	ms_dx;			/* delta-x */
    127 	int	ms_dy;			/* delta-y */
    128 	int	ms_rts;			/* MSCTRL */
    129 	int	ms_nodata;
    130 
    131 	/*
    132 	 * State of upper interface.
    133 	 */
    134 	volatile int ms_ready;		/* event queue is ready */
    135 	struct	evvar ms_events;	/* event queue state */
    136 	kmutex_t ms_lock;
    137 } ms_softc;
    138 
    139 static int ms_match(device_t, cfdata_t, void *);
    140 static void ms_attach(device_t, device_t, void *);
    141 static void ms_trigger(struct zs_chanstate *, int);
    142 void ms_modem(void *);
    143 
    144 CFATTACH_DECL_NEW(ms, sizeof(struct ms_softc),
    145     ms_match, ms_attach, NULL, NULL);
    146 
    147 static void ms_rxint(struct zs_chanstate *);
    148 static void ms_stint(struct zs_chanstate *, int);
    149 static void ms_txint(struct zs_chanstate *);
    150 static void ms_softint(struct zs_chanstate *);
    151 static void ms_input(struct ms_softc *, int);
    152 
    153 struct zsops zsops_ms = {
    154 	ms_rxint,	/* receive char available */
    155 	ms_stint,	/* external/status */
    156 	ms_txint,	/* xmit buffer empty */
    157 	ms_softint,	/* process software interrupt */
    158 };
    159 
    160 dev_type_open(msopen);
    161 dev_type_close(msclose);
    162 dev_type_read(msread);
    163 dev_type_ioctl(msioctl);
    164 dev_type_poll(mspoll);
    165 dev_type_kqfilter(mskqfilter);
    166 
    167 const struct cdevsw ms_cdevsw ={
    168 	.d_open = msopen,
    169 	.d_close = msclose,
    170 	.d_read = msread,
    171 	.d_write = nowrite,
    172 	.d_ioctl = msioctl,
    173 	.d_stop = nostop,
    174 	.d_tty = notty,
    175 	.d_poll = mspoll,
    176 	.d_mmap = nommap,
    177 	.d_kqfilter = mskqfilter,
    178 	.d_flag = 0
    179 };
    180 
    181 /*
    182  * ms_match: how is this zs channel configured?
    183  */
    184 int
    185 ms_match(device_t parent, cfdata_t cf, void *aux)
    186 {
    187 	struct zsc_attach_args *args = aux;
    188 	struct zsc_softc *zsc = device_private(parent);
    189 
    190 	/* Exact match required for the mouse. */
    191 	if (cf->cf_loc[ZSCCF_CHANNEL] != args->channel)
    192 		return 0;
    193 	if (args->channel != 1)
    194 		return 0;
    195 	if (&zsc->zsc_addr->zs_chan_b != (struct zschan *)ZSMS_PHYSADDR)
    196 		return 0;
    197 
    198 	return 2;
    199 }
    200 
    201 void
    202 ms_attach(device_t parent, device_t self, void *aux)
    203 {
    204 	struct ms_softc *ms = device_private(self);
    205 	struct zsc_softc *zsc = device_private(parent);
    206 	struct zs_chanstate *cs;
    207 	int reset;
    208 
    209 	ms->ms_dev = self;
    210 	callout_init(&ms->ms_modem_ch, 0);
    211 	mutex_init(&ms->ms_lock, MUTEX_DEFAULT, IPL_SERIAL);
    212 
    213 	cs = zsc->zsc_cs[1];
    214 	cs->cs_private = ms;
    215 	cs->cs_ops = &zsops_ms;
    216 	ms->ms_cs = cs;
    217 
    218 	/* Initialize the speed, etc. */
    219 	/* May need reset... */
    220 	reset = ZSWR9_B_RESET;
    221 	zs_write_reg(cs, 9, reset);
    222 	/* We don't care about status or tx interrupts. */
    223 	cs->cs_preg[1] = ZSWR1_RIE;
    224 	cs->cs_preg[4] = ZSWR4_CLK_X16 | ZSWR4_TWOSB;
    225 	(void)zs_set_speed(cs, MS_BPS);
    226 	zs_loadchannelregs(cs);
    227 
    228 	/* Initialize translator. */
    229 	ms->ms_ready = 0;
    230 
    231 	aprint_normal("\n");
    232 }
    233 
    234 /****************************************************************
    235  *  Entry points for /dev/mouse
    236  *  (open,close,read,write,...)
    237  ****************************************************************/
    238 
    239 int
    240 msopen(dev_t dev, int flags, int mode, struct lwp *l)
    241 {
    242 	struct ms_softc *ms;
    243 
    244 	ms = device_lookup_private(&ms_cd, minor(dev));
    245 	if (ms == NULL)
    246 		return ENXIO;
    247 
    248 	/* This is an exclusive open device. */
    249 	if (ms->ms_events.ev_io)
    250 		return EBUSY;
    251 	ms->ms_events.ev_io = l->l_proc;
    252 	ev_init(&ms->ms_events, device_xname(ms->ms_dev), &ms->ms_lock);
    253 
    254 	ms->ms_ready = 1;		/* start accepting events */
    255 	ms->ms_rts = 1;
    256 	ms->ms_byteno = -1;
    257 	ms->ms_nodata = 0;
    258 
    259 	/* start sequencer */
    260 	ms_modem(ms);
    261 
    262 	return 0;
    263 }
    264 
    265 int
    266 msclose(dev_t dev, int flags, int mode, struct lwp *l)
    267 {
    268 	struct ms_softc *ms;
    269 
    270 	ms = device_lookup_private(&ms_cd, 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_t dev, struct uio *uio, int flags)
    281 {
    282 	struct ms_softc *ms;
    283 
    284 	ms = device_lookup_private(&ms_cd, minor(dev));
    285 	return ev_read(&ms->ms_events, uio, flags);
    286 }
    287 
    288 int
    289 msioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
    290 {
    291 	struct ms_softc *ms;
    292 
    293 	ms = device_lookup_private(&ms_cd, minor(dev));
    294 
    295 	switch (cmd) {
    296 
    297 	case FIONBIO:		/* we will remove this someday (soon???) */
    298 		return 0;
    299 
    300 	case FIOASYNC:
    301 		ms->ms_events.ev_async = *(int *)data != 0;
    302 		return 0;
    303 
    304 	case FIOSETOWN:
    305 		if (-*(int *)data != ms->ms_events.ev_io->p_pgid
    306 		    && *(int *)data != ms->ms_events.ev_io->p_pid)
    307 			return EPERM;
    308 		return 0;
    309 
    310 	case TIOCSPGRP:
    311 		if (*(int *)data != ms->ms_events.ev_io->p_pgid)
    312 			return EPERM;
    313 		return 0;
    314 
    315 	case VUIDGFORMAT:
    316 		/* we only do firm_events */
    317 		*(int *)data = VUID_FIRM_EVENT;
    318 		return 0;
    319 
    320 	case VUIDSFORMAT:
    321 		if (*(int *)data != VUID_FIRM_EVENT)
    322 			return EINVAL;
    323 		return 0;
    324 	}
    325 	return ENOTTY;
    326 }
    327 
    328 int
    329 mspoll(dev_t dev, int events, struct lwp *l)
    330 {
    331 	struct ms_softc *ms;
    332 
    333 	ms = device_lookup_private(&ms_cd, minor(dev));
    334 	return ev_poll(&ms->ms_events, events, l);
    335 }
    336 
    337 int
    338 mskqfilter(dev_t dev, struct knote *kn)
    339 {
    340 	struct ms_softc *ms;
    341 
    342 	ms = device_lookup_private(&ms_cd, minor(dev));
    343 	return ev_kqfilter(&ms->ms_events, kn);
    344 }
    345 
    346 /****************************************************************
    347  * Middle layer (translator)
    348  ****************************************************************/
    349 
    350 /*
    351  * Called by our ms_softint() routine on input.
    352  */
    353 static void
    354 ms_input(struct ms_softc *ms, int c)
    355 {
    356 	struct firm_event *fe;
    357 	int mb, ub, d, get, put, any;
    358 	static const char to_one[] = { 1, 2, 3 };
    359 	static const int to_id[] = { MS_LEFT, MS_RIGHT, MS_MIDDLE };
    360 
    361 	/*
    362 	 * Discard input if not ready.  Drop sync on parity or framing
    363 	 * error; gain sync on button byte.
    364 	 */
    365 	if (ms->ms_ready == 0)
    366 		return;
    367 
    368 	ms->ms_nodata = 0;
    369 	/*
    370 	 * Run the decode loop, adding to the current information.
    371 	 * We add, rather than replace, deltas, so that if the event queue
    372 	 * fills, we accumulate data for when it opens up again.
    373 	 */
    374 	switch (ms->ms_byteno) {
    375 
    376 	case -1:
    377 		return;
    378 
    379 	case 0:
    380 		/* buttons */
    381 		ms->ms_byteno = 1;
    382 		ms->ms_mb = c & 0x3;
    383 		return;
    384 
    385 	case 1:
    386 		/* delta-x */
    387 		ms->ms_byteno = 2;
    388 		ms->ms_dx += (char)c;
    389 		return;
    390 
    391 	case 2:
    392 		/* delta-y */
    393 		ms->ms_byteno = -1;
    394 		ms->ms_dy += (char)c;
    395 		break;
    396 
    397 	default:
    398 		panic("ms_input");
    399 		/* NOTREACHED */
    400 	}
    401 
    402 	/*
    403 	 * We have at least one event (mouse button, delta-X, or
    404 	 * delta-Y; possibly all three, and possibly three separate
    405 	 * button events).  Deliver these events until we are out
    406 	 * of changes or out of room.  As events get delivered,
    407 	 * mark them `unchanged'.
    408 	 */
    409 	any = 0;
    410 	get = ms->ms_events.ev_get;
    411 	put = ms->ms_events.ev_put;
    412 	fe = &ms->ms_events.ev_q[put];
    413 
    414 	/* NEXT prepares to put the next event, backing off if necessary */
    415 #define	NEXT \
    416 	if ((++put) % EV_QSIZE == get) { \
    417 		put--; \
    418 		goto out; \
    419 	}
    420 	/* ADVANCE completes the `put' of the event */
    421 #define	ADVANCE \
    422 	fe++; \
    423 	if (put >= EV_QSIZE) { \
    424 		put = 0; \
    425 		fe = &ms->ms_events.ev_q[0]; \
    426 	} \
    427 
    428 	mb = ms->ms_mb;
    429 	ub = ms->ms_ub;
    430 	while ((d = mb ^ ub) != 0) {
    431 		/*
    432 		 * Mouse button change.  Convert up to three changes
    433 		 * to the `first' change, and drop it into the event queue.
    434 		 */
    435 		NEXT;
    436 		d = to_one[d - 1];		/* from 1..7 to {1,2,4} */
    437 		fe->id = to_id[d - 1];		/* from {1,2,4} to ID */
    438 		fe->value = mb & d ? VKEY_DOWN : VKEY_UP;
    439 		firm_gettime(fe);
    440 		ADVANCE;
    441 		ub ^= d;
    442 		any++;
    443 	}
    444 	if (ms->ms_dx) {
    445 		NEXT;
    446 		fe->id = LOC_X_DELTA;
    447 		fe->value = ms->ms_dx;
    448 		firm_gettime(fe);
    449 		ADVANCE;
    450 		ms->ms_dx = 0;
    451 		any++;
    452 	}
    453 	if (ms->ms_dy) {
    454 		NEXT;
    455 		fe->id = LOC_Y_DELTA;
    456 		fe->value = -ms->ms_dy;	/* XXX? */
    457 		firm_gettime(fe);
    458 		ADVANCE;
    459 		ms->ms_dy = 0;
    460 		any++;
    461 	}
    462 out:
    463 	if (any) {
    464 		ms->ms_ub = ub;
    465 		ms->ms_events.ev_put = put;
    466 		ev_wakeup(&ms->ms_events);
    467 	}
    468 }
    469 
    470 /****************************************************************
    471  * Interface to the lower layer (zscc)
    472  ****************************************************************/
    473 
    474 static void
    475 ms_rxint(struct zs_chanstate *cs)
    476 {
    477 	struct ms_softc *ms;
    478 	int put, put_next;
    479 	u_char c, rr1;
    480 
    481 	ms = cs->cs_private;
    482 	put = ms->ms_rbput;
    483 
    484 	/*
    485 	 * First read the status, because reading the received char
    486 	 * destroys the status of this char.
    487 	 */
    488 	rr1 = zs_read_reg(cs, 1);
    489 	c = zs_read_data(cs);
    490 
    491 	if (rr1 & (ZSRR1_FE | ZSRR1_DO | ZSRR1_PE)) {
    492 		/* Clear the receive error. */
    493 		zs_write_csr(cs, ZSWR0_RESET_ERRORS);
    494 	}
    495 
    496 	ms->ms_rbuf[put] = (c << 8) | rr1;
    497 	put_next = (put + 1) & MS_RX_RING_MASK;
    498 
    499 	/* Would overrun if increment makes (put==get). */
    500 	if (put_next == ms->ms_rbget) {
    501 		ms->ms_intr_flags |= INTR_RX_OVERRUN;
    502 	} else {
    503 		/* OK, really increment. */
    504 		put = put_next;
    505 	}
    506 
    507 	/* Done reading. */
    508 	ms->ms_rbput = put;
    509 
    510 	/* Ask for softint() call. */
    511 	cs->cs_softreq = 1;
    512 }
    513 
    514 
    515 static void
    516 ms_txint(struct zs_chanstate *cs)
    517 {
    518 	struct ms_softc *ms;
    519 
    520 	ms = cs->cs_private;
    521 	zs_write_csr(cs, ZSWR0_RESET_TXINT);
    522 	ms->ms_intr_flags |= INTR_TX_EMPTY;
    523 	/* Ask for softint() call. */
    524 	cs->cs_softreq = 1;
    525 }
    526 
    527 
    528 static void
    529 ms_stint(struct zs_chanstate *cs, int force)
    530 {
    531 	struct ms_softc *ms;
    532 	int rr0;
    533 
    534 	ms = cs->cs_private;
    535 
    536 	rr0 = zs_read_csr(cs);
    537 	zs_write_csr(cs, ZSWR0_RESET_STATUS);
    538 
    539 	/*
    540 	 * We have to accumulate status line changes here.
    541 	 * Otherwise, if we get multiple status interrupts
    542 	 * before the softint runs, we could fail to notice
    543 	 * some status line changes in the softint routine.
    544 	 * Fix from Bill Studenmund, October 1996.
    545 	 */
    546 	cs->cs_rr0_delta |= (cs->cs_rr0 ^ rr0);
    547 	cs->cs_rr0 = rr0;
    548 	ms->ms_intr_flags |= INTR_ST_CHECK;
    549 
    550 	/* Ask for softint() call. */
    551 	cs->cs_softreq = 1;
    552 }
    553 
    554 
    555 static void
    556 ms_softint(struct zs_chanstate *cs)
    557 {
    558 	struct ms_softc *ms;
    559 	int get, c;
    560 	int intr_flags;
    561 	u_short ring_data;
    562 
    563 	ms = cs->cs_private;
    564 
    565 	mutex_enter(&ms->ms_lock);
    566 	intr_flags = ms->ms_intr_flags;
    567 	ms->ms_intr_flags = 0;
    568 
    569 	/*
    570 	 * Copy data from the receive ring to the event layer.
    571 	 */
    572 	get = ms->ms_rbget;
    573 	while (get != ms->ms_rbput) {
    574 		ring_data = ms->ms_rbuf[get];
    575 		mutex_exit(&ms->ms_lock);
    576 		get = (get + 1) & MS_RX_RING_MASK;
    577 
    578 		/* low byte of ring_data is rr1 */
    579 		c = (ring_data >> 8) & 0xff;
    580 
    581 		if (ring_data & ZSRR1_DO)
    582 			intr_flags |= INTR_RX_OVERRUN;
    583 		if (ring_data & (ZSRR1_FE | ZSRR1_PE)) {
    584 			log(LOG_ERR, "%s: input error (0x%x)\n",
    585 			    device_xname(ms->ms_dev), ring_data);
    586 			c = -1;	/* signal input error */
    587 		}
    588 
    589 		/* Pass this up to the "middle" layer. */
    590 		ms_input(ms, c);
    591 		mutex_enter(&ms->ms_lock);
    592 	}
    593 	mutex_exit(&ms->ms_lock);
    594 
    595 	if (intr_flags & INTR_RX_OVERRUN) {
    596 		log(LOG_ERR, "%s: input overrun\n",
    597 		    device_xname(ms->ms_dev));
    598 	}
    599 	ms->ms_rbget = get;
    600 
    601 	if (intr_flags & INTR_TX_EMPTY) {
    602 		/*
    603 		 * Transmit done.  (Not expected.)
    604 		 */
    605 		log(LOG_ERR, "%s: transmit interrupt?\n",
    606 		    device_xname(ms->ms_dev));
    607 	}
    608 
    609 	if (intr_flags & INTR_ST_CHECK) {
    610 		/*
    611 		 * Status line change.  (Not expected.)
    612 		 */
    613 		log(LOG_ERR, "%s: status interrupt?\n",
    614 		    device_xname(ms->ms_dev));
    615 		mutex_enter(&ms->ms_lock);
    616 		cs->cs_rr0_delta = 0;
    617 		mutex_exit(&ms->ms_lock);
    618 	}
    619 }
    620 
    621 
    622 static void
    623 ms_trigger(struct zs_chanstate *cs, int onoff)
    624 {
    625 	/* for front connected one */
    626 	if (onoff)
    627 		cs->cs_preg[5] |= ZSWR5_RTS;
    628 	else
    629 		cs->cs_preg[5] &= ~ZSWR5_RTS;
    630 	cs->cs_creg[5] = cs->cs_preg[5];
    631 	zs_write_reg(cs, 5, cs->cs_preg[5]);
    632 
    633 	/* for keyborad connected one */
    634 	mfp_send_usart(onoff | 0x40);
    635 }
    636 
    637 /*
    638  * mouse timer interrupt.
    639  * called after system tick interrupt is done.
    640  */
    641 void
    642 ms_modem(void *arg)
    643 {
    644 	struct ms_softc *ms = arg;
    645 
    646 	if (!ms->ms_ready)
    647 		return;
    648 
    649 	mutex_enter(&ms->ms_lock);
    650 
    651 	if (ms->ms_nodata++ > 250) { /* XXX */
    652 		log(LOG_ERR, "%s: no data for 5 secs. resetting.\n",
    653 		    device_xname(ms->ms_dev));
    654 		ms->ms_byteno = -1;
    655 		ms->ms_nodata = 0;
    656 		ms->ms_rts = 0;
    657 	}
    658 
    659 	if (ms->ms_rts) {
    660 		if (ms->ms_byteno == -1) {
    661 			/* start next sequence */
    662 			ms->ms_rts = 0;
    663 			ms_trigger(ms->ms_cs, ms->ms_rts);
    664 			ms->ms_byteno = 0;
    665 		}
    666 	} else {
    667 		ms->ms_rts = 1;
    668 		ms_trigger(ms->ms_cs, ms->ms_rts);
    669 	}
    670 
    671 	mutex_exit(&ms->ms_lock);
    672 	callout_reset(&ms->ms_modem_ch, 2, ms_modem, ms);
    673 }
    674