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mfc.c revision 1.57.18.1
      1 /*	$NetBSD: mfc.c,v 1.57.18.1 2017/04/27 05:36:31 pgoyette Exp $ */
      2 
      3 /*
      4  * Copyright (c) 1982, 1990 The Regents of the University of California.
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. Neither the name of the University nor the names of its contributors
     16  *    may be used to endorse or promote products derived from this software
     17  *    without specific prior written permission.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     29  * SUCH DAMAGE.
     30  */
     31 /*
     32  * Copyright (c) 1994 Michael L. Hitch
     33  *
     34  * Redistribution and use in source and binary forms, with or without
     35  * modification, are permitted provided that the following conditions
     36  * are met:
     37  * 1. Redistributions of source code must retain the above copyright
     38  *    notice, this list of conditions and the following disclaimer.
     39  * 2. Redistributions in binary form must reproduce the above copyright
     40  *    notice, this list of conditions and the following disclaimer in the
     41  *    documentation and/or other materials provided with the distribution.
     42  *
     43  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     44  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     45  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     46  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     47  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     48  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     49  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     50  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     51  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     52  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     53  */
     54 
     55 #include "opt_kgdb.h"
     56 
     57 #include <sys/cdefs.h>
     58 __KERNEL_RCSID(0, "$NetBSD: mfc.c,v 1.57.18.1 2017/04/27 05:36:31 pgoyette Exp $");
     59 
     60 #include <sys/param.h>
     61 #include <sys/systm.h>
     62 #include <sys/kernel.h>
     63 #include <sys/device.h>
     64 #include <sys/tty.h>
     65 #include <sys/proc.h>
     66 #include <sys/file.h>
     67 #include <sys/uio.h>
     68 #include <sys/syslog.h>
     69 #include <sys/queue.h>
     70 #include <sys/conf.h>
     71 #include <sys/kauth.h>
     72 #include <machine/cpu.h>
     73 #include <amiga/amiga/device.h>
     74 #include <amiga/amiga/isr.h>
     75 #include <amiga/amiga/custom.h>
     76 #include <amiga/amiga/cia.h>
     77 #include <amiga/amiga/cc.h>
     78 #include <amiga/dev/zbusvar.h>
     79 
     80 #include <dev/cons.h>
     81 
     82 #include "mfcs.h"
     83 
     84 #ifndef SEROBUF_SIZE
     85 #define SEROBUF_SIZE	128
     86 #endif
     87 #ifndef SERIBUF_SIZE
     88 #define SERIBUF_SIZE	1024
     89 #endif
     90 
     91 #define splser()	spl6()
     92 
     93 /*
     94  * 68581 DUART registers
     95  */
     96 struct mfc_regs {
     97 	volatile u_char du_mr1a;
     98 #define	du_mr2a		du_mr1a
     99 	u_char pad0;
    100 	volatile u_char du_csra;
    101 #define	du_sra		du_csra
    102 	u_char pad2;
    103 	volatile u_char du_cra;
    104 	u_char pad4;
    105 	volatile u_char du_tba;
    106 #define	du_rba		du_tba
    107 	u_char pad6;
    108 	volatile u_char du_acr;
    109 #define	du_ipcr		du_acr
    110 	u_char pad8;
    111 	volatile u_char du_imr;
    112 #define	du_isr		du_imr
    113 	u_char pad10;
    114 	volatile u_char du_ctur;
    115 #define	du_cmsb		du_ctur
    116 	u_char pad12;
    117 	volatile u_char du_ctlr;
    118 #define	du_clsb		du_ctlr
    119 	u_char pad14;
    120 	volatile u_char du_mr1b;
    121 #define	du_mr2b		du_mr1b
    122 	u_char pad16;
    123 	volatile u_char du_csrb;
    124 #define	du_srb		du_csrb
    125 	u_char pad18;
    126 	volatile u_char du_crb;
    127 	u_char pad20;
    128 	volatile u_char du_tbb;
    129 #define	du_rbb		du_tbb
    130 	u_char pad22;
    131 	volatile u_char du_ivr;
    132 	u_char pad24;
    133 	volatile u_char du_opcr;
    134 #define	du_ip		du_opcr
    135 	u_char pad26;
    136 	volatile u_char du_btst;
    137 #define	du_strc		du_btst
    138 	u_char pad28;
    139 	volatile u_char du_btrst;
    140 #define	du_stpc		du_btrst
    141 	u_char pad30;
    142 };
    143 
    144 /*
    145  * 68681 DUART serial port registers
    146  */
    147 struct duart_regs {
    148 	volatile u_char ch_mr1;
    149 #define	ch_mr2		ch_mr1
    150 	u_char pad0;
    151 	volatile u_char	ch_csr;
    152 #define	ch_sr		ch_csr
    153 	u_char pad1;
    154 	volatile u_char	ch_cr;
    155 	u_char pad2;
    156 	volatile u_char	ch_tb;
    157 #define	ch_rb		ch_tb
    158 	u_char pad3;
    159 };
    160 
    161 struct mfc_softc {
    162 	device_t sc_dev;
    163 	struct	isr sc_isr;
    164 	struct	mfc_regs *sc_regs;
    165 	u_long	clk_frq;
    166 	u_short	ct_val;
    167 	u_char	ct_usecnt;
    168 	u_char	imask;
    169 	u_char	mfc_iii;
    170 	u_char	last_ip;
    171 };
    172 
    173 #if NMFCS > 0
    174 struct mfcs_softc {
    175 	device_t sc_dev;
    176 	struct	tty *sc_tty;
    177 	struct	duart_regs *sc_duart;
    178 	struct	mfc_regs *sc_regs;
    179 	struct	mfc_softc *sc_mfc;
    180 	int	swflags;
    181 	long	flags;			/* XXX */
    182 #define CT_USED	1			/* CT in use */
    183 	u_short	*rptr, *wptr, incnt, ovfl;
    184 	u_short	inbuf[SERIBUF_SIZE];
    185 	char	*ptr, *end;
    186 	char	outbuf[SEROBUF_SIZE];
    187 	struct	vbl_node vbl_node;
    188 	void	*mfcs_si;
    189 };
    190 #endif
    191 
    192 #if NMFCP > 0
    193 struct mfcp_softc {
    194 };
    195 #endif
    196 
    197 struct mfc_args {
    198 	struct zbus_args zargs;
    199 	const char	*subdev;
    200 	char	unit;
    201 };
    202 
    203 int	mfcprint(void *, const char *);
    204 void	mfcattach(device_t, device_t, void *);
    205 int	mfcmatch(device_t, cfdata_t, void *);
    206 
    207 #if NMFCS > 0
    208 int	mfcsmatch(device_t, cfdata_t, void *);
    209 void	mfcsattach(device_t, device_t, void *);
    210 int	mfcsparam( struct tty *, struct termios *);
    211 int	mfcshwiflow(struct tty *, int);
    212 void	mfcsstart(struct tty *);
    213 int	mfcsmctl(dev_t, int, int);
    214 void	mfcsxintr(int);
    215 void	mfcseint(int, int);
    216 void	mfcsmint(register int);
    217 void	mfcs_intr_soft(void *);
    218 #endif
    219 
    220 #if NMFCP > 0
    221 void mfcpattach(device_t, device_t, void *);
    222 int mfcpmatch(device_t, cfdata_t, void *);
    223 #endif
    224 int mfcintr(void *);
    225 
    226 CFATTACH_DECL_NEW(mfc, sizeof(struct mfc_softc),
    227     mfcmatch, mfcattach, NULL, NULL);
    228 
    229 #if NMFCS > 0
    230 CFATTACH_DECL_NEW(mfcs, sizeof(struct mfcs_softc),
    231     mfcsmatch, mfcsattach, NULL, NULL);
    232 
    233 extern struct cfdriver mfcs_cd;
    234 #endif
    235 
    236 #if NMFCP > 0
    237 CFATTACH_DECL_NEW(mfcp, sizeof(struct mfcp_softc),
    238     mfcpmatch, mfcpattach, NULL, NULL);
    239 #endif
    240 
    241 dev_type_open(mfcsopen);
    242 dev_type_close(mfcsclose);
    243 dev_type_read(mfcsread);
    244 dev_type_write(mfcswrite);
    245 dev_type_ioctl(mfcsioctl);
    246 dev_type_stop(mfcsstop);
    247 dev_type_tty(mfcstty);
    248 dev_type_poll(mfcspoll);
    249 
    250 const struct cdevsw mfcs_cdevsw = {
    251 	.d_open = mfcsopen,
    252 	.d_close = mfcsclose,
    253 	.d_read = mfcsread,
    254 	.d_write = mfcswrite,
    255 	.d_ioctl = mfcsioctl,
    256 	.d_stop = mfcsstop,
    257 	.d_tty = mfcstty,
    258 	.d_poll = mfcspoll,
    259 	.d_mmap = nommap,
    260 	.d_kqfilter = ttykqfilter,
    261 	.d_discard = nodiscard,
    262 	.d_flag = D_TTY
    263 };
    264 
    265 int	mfcs_active;
    266 int	mfcsdefaultrate = 38400 /*TTYDEF_SPEED*/;
    267 #define SWFLAGS(dev) (sc->swflags | (((dev) & 0x80) == 0 ? TIOCFLAG_SOFTCAR : 0))
    268 
    269 #ifdef notyet
    270 /*
    271  * MultiFaceCard III, II+ (not supported yet), and
    272  * SerialMaster 500+ (not supported yet)
    273  * baud rate tables for BRG set 1 [not used yet]
    274  */
    275 
    276 const struct speedtab mfcs3speedtab1[] = {
    277 	{ 0,		0	},
    278 	{ 100,		0x00	},
    279 	{ 220,		0x11	},
    280 	{ 600,		0x44	},
    281 	{ 1200,		0x55	},
    282 	{ 2400,		0x66	},
    283 	{ 4800,		0x88	},
    284 	{ 9600,		0x99	},
    285 	{ 19200,	0xbb	},
    286 	{ 115200,	0xcc	},
    287 	{ -1,		-1	}
    288 };
    289 
    290 /*
    291  * MultiFaceCard II, I, and SerialMaster 500
    292  * baud rate tables for BRG set 1 [not used yet]
    293  */
    294 
    295 const struct speedtab mfcs2speedtab1[] = {
    296 	{ 0,		0	},
    297 	{ 50,		0x00	},
    298 	{ 110,		0x11	},
    299 	{ 300,		0x44	},
    300 	{ 600,		0x55	},
    301 	{ 1200,		0x66	},
    302 	{ 2400,		0x88	},
    303  	{ 4800,		0x99	},
    304 	{ 9600,		0xbb	},
    305 	{ 38400,	0xcc	},
    306 	{ -1,		-1	}
    307 };
    308 #endif
    309 
    310 /*
    311  * MultiFaceCard III, II+ (not supported yet), and
    312  * SerialMaster 500+ (not supported yet)
    313  * baud rate tables for BRG set 2
    314  */
    315 
    316 const struct speedtab mfcs3speedtab2[] = {
    317 	{ 0,		0	},
    318 	{ 150,		0x00	},
    319 	{ 200,		0x11	},
    320 	{ 300,		0x33	},
    321 	{ 600,		0x44	},
    322 	{ 1200,		0x55	},
    323 	{ 2400,		0x66	},
    324 	{ 4800,		0x88	},
    325 	{ 9600,		0x99	},
    326 	{ 19200,	0xbb	},
    327 	{ 38400,	0xcc	},
    328 	{ -1,		-1	}
    329 };
    330 
    331 /*
    332  * MultiFaceCard II, I, and SerialMaster 500
    333  * baud rate tables for BRG set 2
    334  */
    335 
    336 const struct speedtab mfcs2speedtab2[] = {
    337 	{ 0,		0	},
    338 	{ 75,		0x00	},
    339 	{ 100,		0x11	},
    340 	{ 150,		0x33	},
    341 	{ 300,		0x44	},
    342 	{ 600,		0x55	},
    343 	{ 1200,		0x66	},
    344 	{ 2400,		0x88	},
    345  	{ 4800,		0x99	},
    346 	{ 9600,		0xbb	},
    347 	{ 19200,	0xcc	},
    348 	{ -1,		-1	}
    349 };
    350 
    351 /*
    352  * if we are an bsc/Alf Data MultFaceCard (I, II, and III)
    353  */
    354 int
    355 mfcmatch(device_t parent, cfdata_t cf, void *aux)
    356 {
    357 	struct zbus_args *zap;
    358 
    359 	zap = aux;
    360 	if (zap->manid == 2092 &&
    361 	    (zap->prodid == 16 || zap->prodid == 17 || zap->prodid == 18))
    362 
    363 		return(1);
    364 	return(0);
    365 }
    366 
    367 void
    368 mfcattach(device_t parent, device_t self, void *aux)
    369 {
    370 	struct mfc_softc *scc;
    371 	struct zbus_args *zap;
    372 	struct mfc_args ma;
    373 	int unit;
    374 	struct mfc_regs *rp;
    375 
    376 	zap = aux;
    377 
    378 	printf ("\n");
    379 
    380 	scc = device_private(self);
    381 	scc->sc_dev = self;
    382 	unit = device_unit(self);
    383 	scc->sc_regs = rp = zap->va;
    384 	if (zap->prodid == 18)
    385 		scc->mfc_iii = 3;
    386 	scc->clk_frq = scc->mfc_iii ? 230400 : 115200;
    387 
    388 	rp->du_opcr = 0x00;		/* configure output port? */
    389 	rp->du_btrst = 0x0f;		/* clear modem lines */
    390 	rp->du_ivr = 0;			/* IVR */
    391 	rp->du_imr = 0;			/* IMR */
    392 	rp->du_acr = 0xe0;		/* baud rate generate set 2 */
    393 	rp->du_ctur = 0;
    394 	rp->du_ctlr = 4;
    395 	rp->du_csra = 0xcc;		/* clock select = 38400 */
    396 	rp->du_cra = 0x10;		/* reset mode register ptr */
    397 	rp->du_cra = 0x20;
    398 	rp->du_cra = 0x30;
    399 	rp->du_cra = 0x40;
    400 	rp->du_mr1a = 0x93;		/* MRA1 */
    401 	rp->du_mr2a = 0x17;		/* MRA2 */
    402 	rp->du_csrb = 0xcc;		/* clock select = 38400 */
    403 	rp->du_crb = 0x10;		/* reset mode register ptr */
    404 	rp->du_crb = 0x20;
    405 	rp->du_crb = 0x30;
    406 	rp->du_crb = 0x40;
    407 	rp->du_mr1b = 0x93;		/* MRB1 */
    408 	rp->du_mr2b = 0x17;		/* MRB2 */
    409 	rp->du_cra = 0x05;		/* enable A Rx & Tx */
    410 	rp->du_crb = 0x05;		/* enable B Rx & Tx */
    411 
    412 	scc->sc_isr.isr_intr = mfcintr;
    413 	scc->sc_isr.isr_arg = scc;
    414 	scc->sc_isr.isr_ipl = 6;
    415 	add_isr(&scc->sc_isr);
    416 
    417 	/* configure ports */
    418 	memcpy(&ma.zargs, zap, sizeof(struct zbus_args));
    419 	ma.subdev = "mfcs";
    420 	ma.unit = unit * 2;
    421 	config_found(self, &ma, mfcprint);
    422 	ma.unit = unit * 2 + 1;
    423 	config_found(self, &ma, mfcprint);
    424 	ma.subdev = "mfcp";
    425 	ma.unit = unit;
    426 	config_found(self, &ma, mfcprint);
    427 }
    428 
    429 /*
    430  *
    431  */
    432 int
    433 mfcsmatch(device_t parent, cfdata_t cf, void *aux)
    434 {
    435 	struct mfc_args *ma;
    436 
    437 	ma = aux;
    438 	if (strcmp(ma->subdev, "mfcs") == 0)
    439 		return (1);
    440 	return (0);
    441 }
    442 
    443 void
    444 mfcsattach(device_t parent, device_t self, void *aux)
    445 {
    446 	int unit;
    447 	struct mfcs_softc *sc;
    448 	struct mfc_softc *scc;
    449 	struct mfc_args *ma;
    450 	struct mfc_regs *rp;
    451 
    452 	sc = device_private(self);
    453 	sc->sc_dev = self;
    454 	scc = device_private(parent);
    455 	ma = aux;
    456 
    457 	printf (": input fifo %d output fifo %d\n", SERIBUF_SIZE,
    458 	    SEROBUF_SIZE);
    459 
    460 	unit = ma->unit;
    461 	mfcs_active |= 1 << unit;
    462 	sc->rptr = sc->wptr = sc->inbuf;
    463 	sc->sc_mfc = scc;
    464 	sc->sc_regs = rp = scc->sc_regs;
    465 	sc->sc_duart = (struct duart_regs *) ((unit & 1) ?
    466 	    __UNVOLATILE(&rp->du_mr1b) : __UNVOLATILE(&rp->du_mr1a));
    467 	sc->mfcs_si = softint_establish(SOFTINT_SERIAL, mfcs_intr_soft, sc);
    468 	/*
    469 	 * should have only one vbl routine to handle all ports?
    470 	 */
    471 	sc->vbl_node.function = (void (*) (void *)) mfcsmint;
    472 	sc->vbl_node.data = (void *) unit;
    473 	add_vbl_function(&sc->vbl_node, 1, (void *) unit);
    474 }
    475 
    476 /*
    477  * print diag if pnp is NULL else just extra
    478  */
    479 int
    480 mfcprint(void *aux, const char *pnp)
    481 {
    482 	if (pnp == NULL)
    483 		return(UNCONF);
    484 	return(QUIET);
    485 }
    486 
    487 int
    488 mfcsopen(dev_t dev, int flag, int mode, struct lwp *l)
    489 {
    490 	struct tty *tp;
    491 	struct mfcs_softc *sc;
    492 	int unit, error;
    493 
    494 	error = 0;
    495 	unit = dev & 0x1f;
    496 
    497 	sc = device_lookup_private_acquire(&mfcs_cd, unit);
    498 	if ((mfcs_active & (1 << unit)) == 0) {
    499 		device_release(sc->sc_dev);
    500 		return (ENXIO);
    501 	}
    502 	if (sc->sc_tty)
    503 		tp = sc->sc_tty;
    504 	else {
    505 		tp = sc->sc_tty = tty_alloc();
    506 		tty_attach(tp);
    507 	}
    508 
    509 	tp->t_oproc = (void (*) (struct tty *)) mfcsstart;
    510 	tp->t_param = mfcsparam;
    511 	tp->t_dev = dev;
    512 	tp->t_hwiflow = mfcshwiflow;
    513 
    514 	if (kauth_authorize_device_tty(l->l_cred, KAUTH_DEVICE_TTY_OPEN, tp)) {
    515 		device_release(sc->sc_dev);
    516 		return (EBUSY);
    517 	}
    518 	mutex_spin_enter(&tty_lock);
    519 	if ((tp->t_state & TS_ISOPEN) == 0 && tp->t_wopen == 0) {
    520 		ttychars(tp);
    521 		if (tp->t_ispeed == 0) {
    522 			/*
    523 			 * only when cleared do we reset to defaults.
    524 			 */
    525 			tp->t_iflag = TTYDEF_IFLAG;
    526 			tp->t_oflag = TTYDEF_OFLAG;
    527 			tp->t_cflag = TTYDEF_CFLAG;
    528 			tp->t_lflag = TTYDEF_LFLAG;
    529 			tp->t_ispeed = tp->t_ospeed = mfcsdefaultrate;
    530 		}
    531 		/*
    532 		 * do these all the time
    533 		 */
    534 		if (sc->swflags & TIOCFLAG_CLOCAL)
    535 			tp->t_cflag |= CLOCAL;
    536 		if (sc->swflags & TIOCFLAG_CRTSCTS)
    537 			tp->t_cflag |= CRTSCTS;
    538 		if (sc->swflags & TIOCFLAG_MDMBUF)
    539 			tp->t_cflag |= MDMBUF;
    540 		mfcsparam(tp, &tp->t_termios);
    541 		ttsetwater(tp);
    542 
    543 		(void)mfcsmctl(dev, TIOCM_DTR | TIOCM_RTS, DMSET);
    544 		if ((SWFLAGS(dev) & TIOCFLAG_SOFTCAR) ||
    545 		    (mfcsmctl(dev, 0, DMGET) & TIOCM_CD))
    546 			tp->t_state |= TS_CARR_ON;
    547 		else
    548 			tp->t_state &= ~TS_CARR_ON;
    549 	}
    550 
    551 	/*
    552 	 * if NONBLOCK requested, ignore carrier
    553 	 */
    554 	if (flag & O_NONBLOCK)
    555 		goto done;
    556 
    557 	/*
    558 	 * block waiting for carrier
    559 	 */
    560 	while ((tp->t_state & TS_CARR_ON) == 0 && (tp->t_cflag & CLOCAL) == 0) {
    561 		tp->t_wopen++;
    562 		error = ttysleep(tp, &tp->t_rawcv, true, 0);
    563 		tp->t_wopen--;
    564 		if (error) {
    565 			mutex_spin_exit(&tty_lock);
    566 			device_release(sc->sc_dev);
    567 			return(error);
    568 		}
    569 	}
    570 done:
    571 	/* This is a way to handle lost XON characters */
    572 	if ((flag & O_TRUNC) && (tp->t_state & TS_TTSTOP)) {
    573 		tp->t_state &= ~TS_TTSTOP;
    574 	        ttstart (tp);
    575 	}
    576 	/*
    577 	 * Reset the tty pointer, as there could have been a dialout
    578 	 * use of the tty with a dialin open waiting.
    579 	 */
    580 	tp->t_dev = dev;
    581 	mutex_spin_exit(&tty_lock);
    582 	device_release(sc->sc_dev);
    583 	return tp->t_linesw->l_open(dev, tp);
    584 }
    585 
    586 /*ARGSUSED*/
    587 int
    588 mfcsclose(dev_t dev, int flag, int mode, struct lwp *l)
    589 {
    590 	struct tty *tp;
    591 	int unit;
    592 	struct mfcs_softc *sc =
    593 		device_lookup_private_acquire(&mfcs_cd, dev & 31);
    594 	struct mfc_softc *scc= sc->sc_mfc;
    595 
    596 	unit = dev & 31;
    597 
    598 	tp = sc->sc_tty;
    599 	tp->t_linesw->l_close(tp, flag);
    600 	sc->sc_duart->ch_cr = 0x70;			/* stop break */
    601 
    602 	scc->imask &= ~(0x7 << ((unit & 1) * 4));
    603 	scc->sc_regs->du_imr = scc->imask;
    604 	if (sc->flags & CT_USED) {
    605 		--scc->ct_usecnt;
    606 		sc->flags &= ~CT_USED;
    607 	}
    608 
    609 	/*
    610 	 * If the device is closed, it's close, no matter whether we deal with
    611 	 * modem control signals nor not.
    612 	 */
    613 #if 0
    614 	if (tp->t_cflag & HUPCL || tp->t_wopen != 0 ||
    615 	    (tp->t_state & TS_ISOPEN) == 0)
    616 #endif
    617 		(void) mfcsmctl(dev, 0, DMSET);
    618 	ttyclose(tp);
    619 #if not_yet
    620 	if (tp != &mfcs_cons) {
    621 		remove_vbl_function(&sc->vbl_node);
    622 		tty_free(tp);
    623 		sc->sc_tty = (struct tty *) NULL;
    624 	}
    625 #endif
    626 	device_release(sc->sc_dev);
    627 	return (0);
    628 }
    629 
    630 int
    631 mfcsread(dev_t dev, struct uio *uio, int flag)
    632 {
    633 	int error;
    634 	struct mfcs_softc *sc =
    635 	    device_lookup_private_acquire(&mfcs_cd, dev & 31);
    636 	struct tty *tp = sc->sc_tty;
    637 
    638 	if (tp == NULL) {
    639 		device_release(sc->sc_dev);
    640 		return(ENXIO);
    641 	}
    642 	error = tp->t_linesw->l_read(tp, uio, flag);
    643 
    644 	device_release(sc->sc_dev);
    645 	return error;
    646 }
    647 
    648 int
    649 mfcswrite(dev_t dev, struct uio *uio, int flag)
    650 {
    651 	int error;
    652 	struct mfcs_softc *sc =
    653 	    device_lookup_private_acquire(&mfcs_cd, dev & 31);
    654 	struct tty *tp = sc->sc_tty;
    655 
    656 	if (tp == NULL) {
    657 		device_release(sc->sc_dev);
    658 		return(ENXIO);
    659 	}
    660 	error = tp->t_linesw->l_write(tp, uio, flag);
    661 
    662 	device_release(sc->sc_dev);
    663 	return error;
    664 }
    665 
    666 int
    667 mfcspoll(dev_t dev, int events, struct lwp *l)
    668 {
    669 	int error;
    670 	struct mfcs_softc *sc =
    671 	    device_lookup_private_acquire(&mfcs_cd, dev & 31);
    672 	struct tty *tp = sc->sc_tty;
    673 
    674 	if (tp == NULL) {
    675 		device_release(sc->sc_dev);
    676 		return(ENXIO);
    677 	}
    678 	error = ((*tp->t_linesw->l_poll)(tp, events, l));
    679 
    680 	device_release(sc->sc_dev);
    681 	return error;
    682 }
    683 
    684 struct tty *
    685 mfcstty(dev_t dev)
    686 {
    687 	struct mfcs_softc *sc =
    688 	    device_lookup_private_acquire(&mfcs_cd, dev & 31);
    689 	struct tty *tty;
    690 
    691 	tty = sc->sc_tty;
    692 	device_release(sc->sc_dev);
    693 	return tty;
    694 }
    695 
    696 int
    697 mfcsioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
    698 {
    699 	register struct tty *tp;
    700 	register int error;
    701 	struct mfcs_softc *sc =
    702 	    device_lookup_private_acquire(&mfcs_cd, dev & 31);
    703 
    704 	tp = sc->sc_tty;
    705 	if (!tp) {
    706 		device_release(sc->sc_dev);
    707 		return ENXIO;
    708 	}
    709 
    710 	error = tp->t_linesw->l_ioctl(tp, cmd, data, flag, l);
    711 	if (error != EPASSTHROUGH) {
    712 		device_release(sc->sc_dev);
    713 		return(error);
    714 	}
    715 	error = ttioctl(tp, cmd, data, flag, l);
    716 	if (error != EPASSTHROUGH) {
    717 		device_release(sc->sc_dev);
    718 		return(error);
    719 	}
    720 	error = 0;
    721 	switch (cmd) {
    722 	case TIOCSBRK:
    723 		sc->sc_duart->ch_cr = 0x60;		/* start break */
    724 		break;
    725 
    726 	case TIOCCBRK:
    727 		sc->sc_duart->ch_cr = 0x70;		/* stop break */
    728 		break;
    729 
    730 	case TIOCSDTR:
    731 		(void) mfcsmctl(dev, TIOCM_DTR | TIOCM_RTS, DMBIS);
    732 		break;
    733 
    734 	case TIOCCDTR:
    735 		(void) mfcsmctl(dev, TIOCM_DTR | TIOCM_RTS, DMBIC);
    736 		break;
    737 
    738 	case TIOCMSET:
    739 		(void) mfcsmctl(dev, *(int *) data, DMSET);
    740 		break;
    741 
    742 	case TIOCMBIS:
    743 		(void) mfcsmctl(dev, *(int *) data, DMBIS);
    744 		break;
    745 
    746 	case TIOCMBIC:
    747 		(void) mfcsmctl(dev, *(int *) data, DMBIC);
    748 		break;
    749 
    750 	case TIOCMGET:
    751 		*(int *)data = mfcsmctl(dev, 0, DMGET);
    752 		break;
    753 	case TIOCGFLAGS:
    754 		*(int *)data = SWFLAGS(dev);
    755 		break;
    756 	case TIOCSFLAGS:
    757 		error = kauth_authorize_device_tty(l->l_cred,
    758 		    KAUTH_DEVICE_TTY_PRIVSET, tp);
    759 		if (error != 0)
    760 			error = EPERM;
    761 		else {
    762 			sc->swflags = *(int *)data;
    763                 	sc->swflags &= /* only allow valid flags */
    764                   	(TIOCFLAG_SOFTCAR | TIOCFLAG_CLOCAL | TIOCFLAG_CRTSCTS);
    765 			/* XXXX need to change duart parameters? */
    766 		}
    767 		break;
    768 	default:
    769 		error = EPASSTHROUGH;
    770 	}
    771 
    772 	device_release(sc->sc_dev);
    773 	return error;
    774 }
    775 
    776 int
    777 mfcsparam(struct tty *tp, struct termios *t)
    778 {
    779 	int cflag, unit, ospeed;
    780 	struct mfcs_softc *sc =
    781 	    device_lookup_private_acquire(&mfcs_cd, tp->t_dev & 31);
    782 	struct mfc_softc *scc= sc->sc_mfc;
    783 
    784 	cflag = t->c_cflag;
    785 	unit = tp->t_dev & 31;
    786 	if (sc->flags & CT_USED) {
    787 		--scc->ct_usecnt;
    788 		sc->flags &= ~CT_USED;
    789 	}
    790 	ospeed = ttspeedtab(t->c_ospeed, scc->mfc_iii ? mfcs3speedtab2 :
    791 	    mfcs2speedtab2);
    792 
    793 	/*
    794 	 * If Baud Rate Generator can't generate requested speed,
    795 	 * try to use the counter/timer.
    796 	 */
    797 	if (ospeed < 0 && (scc->clk_frq % t->c_ospeed) == 0) {
    798 		ospeed = scc->clk_frq / t->c_ospeed;	/* divisor */
    799 		if (scc->ct_usecnt > 0 && scc->ct_val != ospeed)
    800 			ospeed = -1;
    801 		else {
    802 			scc->sc_regs->du_ctur = ospeed >> 8;
    803 			scc->sc_regs->du_ctlr = ospeed;
    804 			scc->ct_val = ospeed;
    805 			++scc->ct_usecnt;
    806 			sc->flags |= CT_USED;
    807 			ospeed = 0xdd;
    808 		}
    809 	}
    810 	/* XXXX 68681 duart could handle split speeds */
    811 	if (ospeed < 0 || (t->c_ispeed && t->c_ispeed != t->c_ospeed)) {
    812 		device_release(sc->sc_dev);
    813 		return(EINVAL);
    814 	}
    815 
    816 	/* XXXX handle parity, character size, stop bits, flow control */
    817 
    818 	/*
    819 	 * copy to tty
    820 	 */
    821 	tp->t_ispeed = t->c_ispeed;
    822 	tp->t_ospeed = t->c_ospeed;
    823 	tp->t_cflag = cflag;
    824 
    825 	/*
    826 	 * enable interrupts
    827 	 */
    828 	scc->imask |= (0x2 << ((unit & 1) * 4)) | 0x80;
    829 	scc->sc_regs->du_imr = scc->imask;
    830 #if defined(DEBUG) && 0
    831 	printf("mfcsparam: speed %d => %x ct %d imask %x cflag %x\n",
    832 	    t->c_ospeed, ospeed, scc->ct_val, scc->imask, cflag);
    833 #endif
    834 	if (ospeed == 0)
    835 		(void)mfcsmctl(tp->t_dev, 0, DMSET);	/* hang up line */
    836 	else {
    837 		/*
    838 		 * (re)enable DTR
    839 		 * and set baud rate. (8 bit mode)
    840 		 */
    841 		(void)mfcsmctl(tp->t_dev, TIOCM_DTR | TIOCM_RTS, DMSET);
    842 		sc->sc_duart->ch_csr = ospeed;
    843 	}
    844 	device_release(sc->sc_dev);
    845 	return(0);
    846 }
    847 
    848 int
    849 mfcshwiflow(struct tty *tp, int flag)
    850 {
    851 	struct mfcs_softc *sc =
    852 	    device_lookup_private_acquire(&mfcs_cd, tp->t_dev & 31);
    853 	int unit = tp->t_dev & 1;
    854 
    855         if (flag)
    856 		sc->sc_regs->du_btrst = 1 << unit;
    857 	else
    858 		sc->sc_regs->du_btst = 1 << unit;
    859 	device_release(sc->sc_dev);
    860         return 1;
    861 }
    862 
    863 void
    864 mfcsstart(struct tty *tp)
    865 {
    866 	int cc, s, unit;
    867 	struct mfcs_softc *sc =
    868 	    device_lookup_private_acquire(&mfcs_cd, tp->t_dev & 31);
    869 	struct mfc_softc *scc= sc->sc_mfc;
    870 
    871 	if ((tp->t_state & TS_ISOPEN) == 0) {
    872 		device_release(sc->sc_dev);
    873 		return;
    874 	}
    875 
    876 	unit = tp->t_dev & 1;
    877 
    878 	s = splser();
    879 	if (tp->t_state & (TS_TIMEOUT | TS_TTSTOP))
    880 		goto out;
    881 
    882 	cc = tp->t_outq.c_cc;
    883 	if (!ttypull(tp) || (tp->t_state & TS_BUSY))
    884 		goto out;
    885 
    886 	/*
    887 	 * We only do bulk transfers if using CTSRTS flow control, not for
    888 	 * (probably sloooow) ixon/ixoff devices.
    889 	 */
    890 	if ((tp->t_cflag & CRTSCTS) == 0)
    891 		cc = 1;
    892 
    893 	/*
    894 	 * Limit the amount of output we do in one burst
    895 	 * to prevent hogging the CPU.
    896 	 */
    897 	if (cc > SEROBUF_SIZE)
    898 		cc = SEROBUF_SIZE;
    899 	cc = q_to_b(&tp->t_outq, sc->outbuf, cc);
    900 	if (cc > 0) {
    901 		tp->t_state |= TS_BUSY;
    902 
    903 		sc->ptr = sc->outbuf;
    904 		sc->end = sc->outbuf + cc;
    905 
    906 		/*
    907 		 * Get first character out, then have TBE-interrupts blow out
    908 		 * further characters, until buffer is empty, and TS_BUSY gets
    909 		 * cleared.
    910 		 */
    911 		sc->sc_duart->ch_tb = *sc->ptr++;
    912 		scc->imask |= 1 << (unit * 4);
    913 		sc->sc_regs->du_imr = scc->imask;
    914 	}
    915 out:
    916 	splx(s);
    917 	device_release(sc->sc_dev);
    918 }
    919 
    920 /*
    921  * Stop output on a line.
    922  */
    923 /*ARGSUSED*/
    924 void
    925 mfcsstop(struct tty *tp, int flag)
    926 {
    927 	int s;
    928 
    929 	s = splser();
    930 	if (tp->t_state & TS_BUSY) {
    931 		if ((tp->t_state & TS_TTSTOP) == 0)
    932 			tp->t_state |= TS_FLUSH;
    933 	}
    934 	splx(s);
    935 }
    936 
    937 int
    938 mfcsmctl(dev_t dev, int bits, int how)
    939 {
    940 	int unit, s;
    941 	u_char ub = 0;
    942 	struct mfcs_softc *sc =
    943 	    device_lookup_private_acquire(&mfcs_cd, dev & 31);
    944 
    945 	unit = dev & 1;
    946 
    947 	/*
    948 	 * convert TIOCM* mask into CIA mask
    949 	 * which is active low
    950 	 */
    951 	if (how != DMGET) {
    952 		/*
    953 		 * need to save current state of DTR & RTS ?
    954 		 */
    955 		if (bits & TIOCM_DTR)
    956 			ub |= 0x04 << unit;
    957 		if (bits & TIOCM_RTS)
    958 			ub |= 0x01 << unit;
    959 	}
    960 	s = splser();
    961 	switch (how) {
    962 	case DMSET:
    963 		sc->sc_regs->du_btst = ub;
    964 		sc->sc_regs->du_btrst = ub ^ (0x05 << unit);
    965 		break;
    966 
    967 	case DMBIC:
    968 		sc->sc_regs->du_btrst = ub;
    969 		ub = ~sc->sc_regs->du_ip;
    970 		break;
    971 
    972 	case DMBIS:
    973 		sc->sc_regs->du_btst = ub;
    974 		ub = ~sc->sc_regs->du_ip;
    975 		break;
    976 
    977 	case DMGET:
    978 		ub = ~sc->sc_regs->du_ip;
    979 		break;
    980 	}
    981 	(void)splx(s);
    982 
    983 	/* XXXX should keep DTR & RTS states in softc? */
    984 	bits = TIOCM_DTR | TIOCM_RTS;
    985 	if (ub & (1 << unit))
    986 		bits |= TIOCM_CTS;
    987 	if (ub & (4 << unit))
    988 		bits |= TIOCM_DSR;
    989 	if (ub & (0x10 << unit))
    990 		bits |= TIOCM_CD;
    991 	/* XXXX RI is not supported on all boards */
    992 	if (sc->sc_regs->pad26 & (1 << unit))
    993 		bits |= TIOCM_RI;
    994 
    995 	device_release(sc->sc_dev);
    996 	return(bits);
    997 }
    998 
    999 /*
   1000  * Level 6 interrupt processing for the MultiFaceCard 68681 DUART
   1001  */
   1002 
   1003 int
   1004 mfcintr(void *arg)
   1005 {
   1006 	struct mfc_softc *scc = arg;
   1007 	struct mfcs_softc *sc;
   1008 	struct mfc_regs *regs;
   1009 	struct tty *tp;
   1010 	int istat, unit;
   1011 	u_short c;
   1012 
   1013 	regs = scc->sc_regs;
   1014 	istat = regs->du_isr & scc->imask;
   1015 	if (istat == 0)
   1016 		return (0);
   1017 	unit = device_unit(scc->sc_dev) * 2;
   1018 	if (istat & 0x02) {		/* channel A receive interrupt */
   1019 		sc = device_lookup_private_acquire(&mfcs_cd, unit);
   1020 		while (1) {
   1021 			c = regs->du_sra << 8;
   1022 			if ((c & 0x0100) == 0)
   1023 				break;
   1024 			c |= regs->du_rba;
   1025 			if (sc->incnt == SERIBUF_SIZE)
   1026 				++sc->ovfl;
   1027 			else {
   1028 				*sc->wptr++ = c;
   1029 				if (sc->wptr == sc->inbuf + SERIBUF_SIZE)
   1030 					sc->wptr = sc->inbuf;
   1031 				++sc->incnt;
   1032 				if (sc->incnt > SERIBUF_SIZE - 16)
   1033 					regs->du_btrst = 1;
   1034 			}
   1035 			if (c & 0x1000)
   1036 				regs->du_cra = 0x40;
   1037 		}
   1038 		device_release(sc->sc_dev);
   1039 	}
   1040 	if (istat & 0x20) {		/* channel B receive interrupt */
   1041 		sc = device_lookup_private_acquire(&mfcs_cd, unit + 1);
   1042 		while (1) {
   1043 			c = regs->du_srb << 8;
   1044 			if ((c & 0x0100) == 0)
   1045 				break;
   1046 			c |= regs->du_rbb;
   1047 			if (sc->incnt == SERIBUF_SIZE)
   1048 				++sc->ovfl;
   1049 			else {
   1050 				*sc->wptr++ = c;
   1051 				if (sc->wptr == sc->inbuf + SERIBUF_SIZE)
   1052 					sc->wptr = sc->inbuf;
   1053 				++sc->incnt;
   1054 				if (sc->incnt > SERIBUF_SIZE - 16)
   1055 					regs->du_btrst = 2;
   1056 			}
   1057 			if (c & 0x1000)
   1058 				regs->du_crb = 0x40;
   1059 		}
   1060 		device_release(sc->sc_dev);
   1061 	}
   1062 	if (istat & 0x01) {		/* channel A transmit interrupt */
   1063 		sc = device_lookup_private_acquire(&mfcs_cd, unit);
   1064 		tp = sc->sc_tty;
   1065 		if (sc->ptr == sc->end) {
   1066 			tp->t_state &= ~(TS_BUSY | TS_FLUSH);
   1067 			scc->imask &= ~0x01;
   1068 			regs->du_imr = scc->imask;
   1069 			softint_schedule(sc->mfcs_si);
   1070 		}
   1071 		else
   1072 			regs->du_tba = *sc->ptr++;
   1073 		device_release(sc->sc_dev);
   1074 	}
   1075 	if (istat & 0x10) {		/* channel B transmit interrupt */
   1076 		sc = device_lookup_private_acquire(&mfcs_cd, unit + 1);
   1077 		tp = sc->sc_tty;
   1078 		if (sc->ptr == sc->end) {
   1079 			tp->t_state &= ~(TS_BUSY | TS_FLUSH);
   1080 			scc->imask &= ~0x10;
   1081 			regs->du_imr = scc->imask;
   1082 			softint_schedule(sc->mfcs_si);
   1083 		}
   1084 		else
   1085 			regs->du_tbb = *sc->ptr++;
   1086 		device_release(sc->sc_dev);
   1087 	}
   1088 	if (istat & 0x80) {		/* input port change interrupt */
   1089 		c = regs->du_ipcr;
   1090 		printf ("%s: ipcr %02x", device_xname(scc->sc_dev), c);
   1091 	}
   1092 	return(1);
   1093 }
   1094 
   1095 void
   1096 mfcsxintr(int unit)
   1097 {
   1098 	int s1, s2, ovfl;
   1099 	struct mfcs_softc *sc =
   1100 	    device_lookup_private_acquire(&mfcs_cd, unit);
   1101 	struct tty *tp = sc->sc_tty;
   1102 
   1103 	/*
   1104 	 * Make sure we're not interrupted by another
   1105 	 * vbl, but allow level6 ints
   1106 	 */
   1107 	s1 = spltty();
   1108 
   1109 	/*
   1110 	 * pass along any acumulated information
   1111 	 * while input is not blocked
   1112 	 */
   1113 	while (sc->incnt && (tp->t_state & TS_TBLOCK) == 0) {
   1114 		/*
   1115 		 * no collision with ser_fastint()
   1116 		 */
   1117 		mfcseint(unit, *sc->rptr++);
   1118 
   1119 		ovfl = 0;
   1120 		/* lock against mfcs_fastint() */
   1121 		s2 = splser();
   1122 		--sc->incnt;
   1123 		if (sc->rptr == sc->inbuf + SERIBUF_SIZE)
   1124 			sc->rptr = sc->inbuf;
   1125 		if (sc->ovfl != 0) {
   1126 			ovfl = sc->ovfl;
   1127 			sc->ovfl = 0;
   1128 		}
   1129 		splx(s2);
   1130 		if (ovfl != 0)
   1131 			log(LOG_WARNING, "%s: %d buffer overflow!\n",
   1132 			    device_xname(sc->sc_dev), ovfl);
   1133 	}
   1134 	if (sc->incnt == 0 && (tp->t_state & TS_TBLOCK) == 0) {
   1135 		sc->sc_regs->du_btst = 1 << unit;	/* XXXX */
   1136 	}
   1137 	splx(s1);
   1138 	device_release(sc->sc_dev);
   1139 }
   1140 
   1141 void
   1142 mfcseint(int unit, int stat)
   1143 {
   1144 	struct mfcs_softc *sc = device_lookup_private_acquire(&mfcs_cd, unit);
   1145 	struct tty *tp;
   1146 	u_char ch;
   1147 	int c;
   1148 
   1149 	tp = sc->sc_tty;
   1150 	ch = stat & 0xff;
   1151 	c = ch;
   1152 
   1153 	if ((tp->t_state & TS_ISOPEN) == 0) {
   1154 #ifdef KGDB
   1155 		extern const struct cdevsw ser_cdevsw;
   1156 		int maj;
   1157 
   1158 		/* we don't care about parity errors */
   1159 		maj = cdevsw_lookup_major(&ser_cdevsw);
   1160 		if (kgdb_dev == makedev(maj, unit) && c == FRAME_END)
   1161 			kgdb_connect(0);	/* trap into kgdb */
   1162 #endif
   1163 		device_release(sc->sc_dev);
   1164 		return;
   1165 	}
   1166 
   1167 	/*
   1168 	 * Check for break and (if enabled) parity error.
   1169 	 */
   1170 	if (stat & 0xc000)
   1171 		c |= TTY_FE;
   1172 	else if (stat & 0x2000)
   1173 			c |= TTY_PE;
   1174 
   1175 	if (stat & 0x1000)
   1176 		log(LOG_WARNING, "%s: fifo overflow\n",
   1177 		    device_xname(device_lookup_private(&mfcs_cd, unit)));
   1178 
   1179 	tp->t_linesw->l_rint(c, tp);
   1180 	device_release(sc->sc_dev);
   1181 }
   1182 
   1183 /*
   1184  * This interrupt is periodically invoked in the vertical blank
   1185  * interrupt.  It's used to keep track of the modem control lines
   1186  * and (new with the fast_int code) to move accumulated data
   1187  * up into the tty layer.
   1188  */
   1189 void
   1190 mfcsmint(int unit)
   1191 {
   1192 	struct tty *tp;
   1193 	struct mfcs_softc *sc = device_lookup_private_acquire(&mfcs_cd, unit);
   1194 	u_char stat, last, istat;
   1195 
   1196 	tp = sc->sc_tty;
   1197 	if (!tp) {
   1198 		device_release(sc->sc-dev);
   1199 		return;
   1200 	}
   1201 	if ((tp->t_state & TS_ISOPEN) == 0 && tp->t_wopen == 0) {
   1202 		sc->rptr = sc->wptr = sc->inbuf;
   1203 		sc->incnt = 0;
   1204 		device_release(sc->sc_dev);
   1205 		return;
   1206 	}
   1207 	/*
   1208 	 * empty buffer
   1209 	 */
   1210 	mfcsxintr(unit);
   1211 
   1212 	stat = ~sc->sc_regs->du_ip;
   1213 	last = sc->sc_mfc->last_ip;
   1214 	sc->sc_mfc->last_ip = stat;
   1215 
   1216 	/*
   1217 	 * check whether any interesting signal changed state
   1218 	 */
   1219 	istat = stat ^ last;
   1220 
   1221 	if ((istat & (0x10 << (unit & 1))) && 		/* CD changed */
   1222 	    (SWFLAGS(tp->t_dev) & TIOCFLAG_SOFTCAR) == 0) {
   1223 		if (stat & (0x10 << (unit & 1)))
   1224 			tp->t_linesw->l_modem(tp, 1);
   1225 		else if (tp->t_linesw->l_modem(tp, 0) == 0) {
   1226 			sc->sc_regs->du_btrst = 0x0a << (unit & 1);
   1227 		}
   1228 	}
   1229 	device_release(sc->sc_dev);
   1230 }
   1231 
   1232 void
   1233 mfcs_intr_soft(void *arg)
   1234 {
   1235 	struct mfcs_softc *sc = (struct mfcs_softc *)arg;
   1236 	struct tty *tp = sc->sc_tty;
   1237 
   1238 	if (tp->t_linesw)
   1239 		tp->t_linesw->l_start(tp);
   1240 	else
   1241 		mfcsstart(tp);
   1242 }
   1243