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sscom.c revision 1.32
      1 /*	$NetBSD: sscom.c,v 1.32 2009/12/09 12:42:59 he Exp $ */
      2 
      3 /*
      4  * Copyright (c) 2002, 2003 Fujitsu Component Limited
      5  * Copyright (c) 2002, 2003 Genetec Corporation
      6  * All rights reserved.
      7  *
      8  * Redistribution and use in source and binary forms, with or without
      9  * modification, are permitted provided that the following conditions
     10  * are met:
     11  * 1. Redistributions of source code must retain the above copyright
     12  *    notice, this list of conditions and the following disclaimer.
     13  * 2. Redistributions in binary form must reproduce the above copyright
     14  *    notice, this list of conditions and the following disclaimer in the
     15  *    documentation and/or other materials provided with the distribution.
     16  * 3. Neither the name of The Fujitsu Component Limited nor the name of
     17  *    Genetec corporation may not be used to endorse or promote products
     18  *    derived from this software without specific prior written permission.
     19  *
     20  * THIS SOFTWARE IS PROVIDED BY FUJITSU COMPONENT LIMITED AND GENETEC
     21  * CORPORATION ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
     22  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
     23  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
     24  * DISCLAIMED.  IN NO EVENT SHALL FUJITSU COMPONENT LIMITED OR GENETEC
     25  * CORPORATION BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     26  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     27  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
     28  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
     29  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
     30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
     31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     32  * SUCH DAMAGE.
     33  */
     34 
     35 /*-
     36  * Copyright (c) 1998, 1999 The NetBSD Foundation, Inc.
     37  * All rights reserved.
     38  *
     39  * This code is derived from software contributed to The NetBSD Foundation
     40  * by Charles M. Hannum.
     41  *
     42  * Redistribution and use in source and binary forms, with or without
     43  * modification, are permitted provided that the following conditions
     44  * are met:
     45  * 1. Redistributions of source code must retain the above copyright
     46  *    notice, this list of conditions and the following disclaimer.
     47  * 2. Redistributions in binary form must reproduce the above copyright
     48  *    notice, this list of conditions and the following disclaimer in the
     49  *    documentation and/or other materials provided with the distribution.
     50  *
     51  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     52  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     53  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     54  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     55  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     56  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     57  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     58  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     59  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     60  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     61  * POSSIBILITY OF SUCH DAMAGE.
     62  */
     63 
     64 /*
     65  * Copyright (c) 1991 The Regents of the University of California.
     66  * All rights reserved.
     67  *
     68  * Redistribution and use in source and binary forms, with or without
     69  * modification, are permitted provided that the following conditions
     70  * are met:
     71  * 1. Redistributions of source code must retain the above copyright
     72  *    notice, this list of conditions and the following disclaimer.
     73  * 2. Redistributions in binary form must reproduce the above copyright
     74  *    notice, this list of conditions and the following disclaimer in the
     75  *    documentation and/or other materials provided with the distribution.
     76  * 3. Neither the name of the University nor the names of its contributors
     77  *    may be used to endorse or promote products derived from this software
     78  *    without specific prior written permission.
     79  *
     80  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     81  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     82  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     83  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     84  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     85  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     86  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     87  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     88  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     89  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     90  * SUCH DAMAGE.
     91  *
     92  *	@(#)com.c	7.5 (Berkeley) 5/16/91
     93  */
     94 
     95 /*
     96  * Support integrated UARTs of Samsung S3C2800/2400X/2410X
     97  * Derived from sys/dev/ic/com.c
     98  */
     99 
    100 #include <sys/cdefs.h>
    101 __KERNEL_RCSID(0, "$NetBSD: sscom.c,v 1.32 2009/12/09 12:42:59 he Exp $");
    102 
    103 #include "opt_sscom.h"
    104 #include "opt_ddb.h"
    105 #include "opt_kgdb.h"
    106 #include "opt_multiprocessor.h"
    107 #include "opt_lockdebug.h"
    108 
    109 #include "rnd.h"
    110 #if NRND > 0 && defined(RND_COM)
    111 #include <sys/rnd.h>
    112 #endif
    113 
    114 /*
    115  * Override cnmagic(9) macro before including <sys/systm.h>.
    116  * We need to know if cn_check_magic triggered debugger, so set a flag.
    117  * Callers of cn_check_magic must declare int cn_trapped = 0;
    118  * XXX: this is *ugly*!
    119  */
    120 #define cn_trap()				\
    121 	do {					\
    122 		console_debugger();		\
    123 		cn_trapped = 1;			\
    124 	} while (/* CONSTCOND */ 0)
    125 
    126 #include <sys/param.h>
    127 #include <sys/systm.h>
    128 #include <sys/ioctl.h>
    129 #include <sys/select.h>
    130 #include <sys/tty.h>
    131 #include <sys/proc.h>
    132 #include <sys/conf.h>
    133 #include <sys/file.h>
    134 #include <sys/uio.h>
    135 #include <sys/kernel.h>
    136 #include <sys/syslog.h>
    137 #include <sys/types.h>
    138 #include <sys/device.h>
    139 #include <sys/malloc.h>
    140 #include <sys/timepps.h>
    141 #include <sys/vnode.h>
    142 #include <sys/kauth.h>
    143 #include <sys/intr.h>
    144 #include <sys/bus.h>
    145 
    146 #include <arm/s3c2xx0/s3c2xx0reg.h>
    147 #include <arm/s3c2xx0/s3c2xx0var.h>
    148 #if defined(SSCOM_S3C2410) || defined(SSCOM_S3C2400)
    149 #include <arm/s3c2xx0/s3c24x0reg.h>
    150 #elif defined(SSCOM_S3C2800)
    151 #include <arm/s3c2xx0/s3c2800reg.h>
    152 #endif
    153 #include <arm/s3c2xx0/sscom_var.h>
    154 #include <dev/cons.h>
    155 
    156 dev_type_open(sscomopen);
    157 dev_type_close(sscomclose);
    158 dev_type_read(sscomread);
    159 dev_type_write(sscomwrite);
    160 dev_type_ioctl(sscomioctl);
    161 dev_type_stop(sscomstop);
    162 dev_type_tty(sscomtty);
    163 dev_type_poll(sscompoll);
    164 
    165 int	sscomcngetc	(dev_t);
    166 void	sscomcnputc	(dev_t, int);
    167 void	sscomcnpollc	(dev_t, int);
    168 
    169 #define	integrate	static inline
    170 void 	sscomsoft	(void *);
    171 
    172 integrate void sscom_rxsoft	(struct sscom_softc *, struct tty *);
    173 integrate void sscom_txsoft	(struct sscom_softc *, struct tty *);
    174 integrate void sscom_stsoft	(struct sscom_softc *, struct tty *);
    175 integrate void sscom_schedrx	(struct sscom_softc *);
    176 static void	sscom_modem(struct sscom_softc *, int);
    177 static void	sscom_break(struct sscom_softc *, int);
    178 static void	sscom_iflush(struct sscom_softc *);
    179 static void	sscom_hwiflow(struct sscom_softc *);
    180 static void	sscom_loadchannelregs(struct sscom_softc *);
    181 static void	tiocm_to_sscom(struct sscom_softc *, u_long, int);
    182 static int	sscom_to_tiocm(struct sscom_softc *);
    183 static void	tiocm_to_sscom(struct sscom_softc *, u_long, int);
    184 static int	sscom_to_tiocm(struct sscom_softc *);
    185 static void	sscom_iflush(struct sscom_softc *);
    186 
    187 static int	sscomhwiflow(struct tty *tp, int block);
    188 static int	sscom_init(bus_space_tag_t, const struct sscom_uart_info *,
    189 		    int, int, tcflag_t, bus_space_handle_t *);
    190 
    191 extern struct cfdriver sscom_cd;
    192 
    193 const struct cdevsw sscom_cdevsw = {
    194 	sscomopen, sscomclose, sscomread, sscomwrite, sscomioctl,
    195 	sscomstop, sscomtty, sscompoll, nommap, ttykqfilter, D_TTY
    196 };
    197 
    198 /*
    199  * Make this an option variable one can patch.
    200  * But be warned:  this must be a power of 2!
    201  */
    202 u_int sscom_rbuf_size = SSCOM_RING_SIZE;
    203 
    204 /* Stop input when 3/4 of the ring is full; restart when only 1/4 is full. */
    205 u_int sscom_rbuf_hiwat = (SSCOM_RING_SIZE * 1) / 4;
    206 u_int sscom_rbuf_lowat = (SSCOM_RING_SIZE * 3) / 4;
    207 
    208 static int	sscomconsunit = -1;
    209 static bus_space_tag_t sscomconstag;
    210 static bus_space_handle_t sscomconsioh;
    211 static int	sscomconsattached;
    212 static int	sscomconsrate;
    213 static tcflag_t sscomconscflag;
    214 static struct cnm_state sscom_cnm_state;
    215 
    216 #ifdef KGDB
    217 #include <sys/kgdb.h>
    218 
    219 static int sscom_kgdb_unit = -1;
    220 static bus_space_tag_t sscom_kgdb_iot;
    221 static bus_space_handle_t sscom_kgdb_ioh;
    222 static int sscom_kgdb_attached;
    223 
    224 int	sscom_kgdb_getc (void *);
    225 void	sscom_kgdb_putc (void *, int);
    226 #endif /* KGDB */
    227 
    228 #define	SSCOMUNIT_MASK  	0x7f
    229 #define	SSCOMDIALOUT_MASK	0x80
    230 
    231 #define	SSCOMUNIT(x)	(minor(x) & SSCOMUNIT_MASK)
    232 #define	SSCOMDIALOUT(x)	(minor(x) & SSCOMDIALOUT_MASK)
    233 
    234 #if 0
    235 #define	SSCOM_ISALIVE(sc)	((sc)->enabled != 0 && \
    236 				 device_is_active(&(sc)->sc_dev))
    237 #else
    238 #define	SSCOM_ISALIVE(sc)	device_is_active(&(sc)->sc_dev)
    239 #endif
    240 
    241 #define	BR	BUS_SPACE_BARRIER_READ
    242 #define	BW	BUS_SPACE_BARRIER_WRITE
    243 #define SSCOM_BARRIER(t, h, f) /* no-op */
    244 
    245 #if (defined(MULTIPROCESSOR) || defined(LOCKDEBUG)) && defined(SSCOM_MPLOCK)
    246 
    247 #define SSCOM_LOCK(sc) simple_lock(&(sc)->sc_lock)
    248 #define SSCOM_UNLOCK(sc) simple_unlock(&(sc)->sc_lock)
    249 
    250 #else
    251 
    252 #define SSCOM_LOCK(sc)
    253 #define SSCOM_UNLOCK(sc)
    254 
    255 #endif
    256 
    257 #ifndef SSCOM_TOLERANCE
    258 #define	SSCOM_TOLERANCE	30	/* XXX: baud rate tolerance, in 0.1% units */
    259 #endif
    260 
    261 /* value for UCON */
    262 #define UCON_RXINT_MASK	  \
    263 	(UCON_RXMODE_MASK|UCON_ERRINT|UCON_TOINT|UCON_RXINT_TYPE)
    264 #define UCON_RXINT_ENABLE \
    265 	(UCON_RXMODE_INT|UCON_ERRINT|UCON_TOINT|UCON_RXINT_TYPE_LEVEL)
    266 #define UCON_TXINT_MASK   (UCON_TXMODE_MASK|UCON_TXINT_TYPE)
    267 #define UCON_TXINT_ENABLE (UCON_TXMODE_INT|UCON_TXINT_TYPE_LEVEL)
    268 
    269 /* we don't want tx interrupt on debug port, but it is needed to
    270    have transmitter active */
    271 #define UCON_DEBUGPORT	  (UCON_RXINT_ENABLE|UCON_TXINT_ENABLE)
    272 
    273 
    274 static inline void
    275 __sscom_output_chunk(struct sscom_softc *sc, int ufstat)
    276 {
    277 	int n, space;
    278 	bus_space_tag_t iot = sc->sc_iot;
    279 	bus_space_handle_t ioh = sc->sc_ioh;
    280 
    281 	n = sc->sc_tbc;
    282 	space = 16 - ((ufstat & UFSTAT_TXCOUNT) >> UFSTAT_TXCOUNT_SHIFT);
    283 
    284 	if (n > space)
    285 		n = space;
    286 
    287 	if (n > 0) {
    288 		bus_space_write_multi_1(iot, ioh, SSCOM_UTXH, sc->sc_tba, n);
    289 		sc->sc_tbc -= n;
    290 		sc->sc_tba += n;
    291 	}
    292 }
    293 
    294 static void
    295 sscom_output_chunk(struct sscom_softc *sc)
    296 {
    297 	int ufstat = bus_space_read_2(sc->sc_iot, sc->sc_ioh, SSCOM_UFSTAT);
    298 
    299 	if (!(ufstat & UFSTAT_TXFULL))
    300 		__sscom_output_chunk(sc, ufstat);
    301 }
    302 
    303 int
    304 sscomspeed(long speed, long frequency)
    305 {
    306 #define	divrnd(n, q)	(((n)*2/(q)+1)/2)	/* divide and round off */
    307 
    308 	int x, err;
    309 
    310 	if (speed <= 0)
    311 		return -1;
    312 	x = divrnd(frequency / 16, speed);
    313 	if (x <= 0)
    314 		return -1;
    315 	err = divrnd(((quad_t)frequency) * 1000 / 16, speed * x) - 1000;
    316 	if (err < 0)
    317 		err = -err;
    318 	if (err > SSCOM_TOLERANCE)
    319 		return -1;
    320 	return x-1;
    321 
    322 #undef	divrnd
    323 }
    324 
    325 void sscomstatus (struct sscom_softc *, const char *);
    326 
    327 #ifdef SSCOM_DEBUG
    328 int	sscom_debug = 0;
    329 
    330 void
    331 sscomstatus(struct sscom_softc *sc, const char *str)
    332 {
    333 	struct tty *tp = sc->sc_tty;
    334 	int umstat = bus_space_read_1(sc->sc_iot, sc->sc_iot, SSCOM_UMSTAT);
    335 	int umcon = bus_space_read_1(sc->sc_iot, sc->sc_iot, SSCOM_UMCON);
    336 
    337 	printf("%s: %s %sclocal  %sdcd %sts_carr_on %sdtr %stx_stopped\n",
    338 	    sc->sc_dev.dv_xname, str,
    339 	    ISSET(tp->t_cflag, CLOCAL) ? "+" : "-",
    340 	    "+",			/* DCD */
    341 	    ISSET(tp->t_state, TS_CARR_ON) ? "+" : "-",
    342 	    "+",			/* DTR */
    343 	    sc->sc_tx_stopped ? "+" : "-");
    344 
    345 	printf("%s: %s %scrtscts %scts %sts_ttstop  %srts %xrx_flags\n",
    346 	    sc->sc_dev.dv_xname, str,
    347 	    ISSET(tp->t_cflag, CRTSCTS) ? "+" : "-",
    348 	    ISSET(umstat, UMSTAT_CTS) ? "+" : "-",
    349 	    ISSET(tp->t_state, TS_TTSTOP) ? "+" : "-",
    350 	    ISSET(umcon, UMCON_RTS) ? "+" : "-",
    351 	    sc->sc_rx_flags);
    352 }
    353 #else
    354 #define sscom_debug  0
    355 #endif
    356 
    357 static void
    358 sscom_enable_debugport(struct sscom_softc *sc)
    359 {
    360 	int s;
    361 
    362 	/* Turn on line break interrupt, set carrier. */
    363 	s = splserial();
    364 	SSCOM_LOCK(sc);
    365 	sc->sc_ucon = UCON_DEBUGPORT;
    366 	bus_space_write_2(sc->sc_iot, sc->sc_ioh, SSCOM_UCON, sc->sc_ucon);
    367 	sc->sc_umcon = UMCON_RTS|UMCON_DTR;
    368 	sc->set_modem_control(sc);
    369 	sscom_enable_rxint(sc);
    370 	sscom_disable_txint(sc);
    371 	SSCOM_UNLOCK(sc);
    372 	splx(s);
    373 }
    374 
    375 static void
    376 sscom_set_modem_control(struct sscom_softc *sc)
    377 {
    378 	/* flob RTS */
    379 	bus_space_write_1(sc->sc_iot, sc->sc_ioh,
    380 	    SSCOM_UMCON, sc->sc_umcon & UMCON_HW_MASK);
    381 	/* ignore DTR */
    382 }
    383 
    384 static int
    385 sscom_read_modem_status(struct sscom_softc *sc)
    386 {
    387 	int msts;
    388 
    389 	msts = bus_space_read_1(sc->sc_iot, sc->sc_ioh, SSCOM_UMSTAT);
    390 
    391 	/* DCD and DSR are always on */
    392 	return (msts & UMSTAT_CTS) | MSTS_DCD | MSTS_DSR;
    393 }
    394 
    395 void
    396 sscom_attach_subr(struct sscom_softc *sc)
    397 {
    398 	int unit = sc->sc_unit;
    399 	bus_space_tag_t iot = sc->sc_iot;
    400 	bus_space_handle_t ioh = sc->sc_ioh;
    401 	struct tty *tp;
    402 
    403 	callout_init(&sc->sc_diag_callout, 0);
    404 #if (defined(MULTIPROCESSOR) || defined(LOCKDEBUG)) && defined(SSCOM_MPLOCK)
    405 	simple_lock_init(&sc->sc_lock);
    406 #endif
    407 
    408 	sc->sc_ucon = UCON_RXINT_ENABLE|UCON_TXINT_ENABLE;
    409 
    410 	/*
    411 	 * set default for modem control hook
    412 	 */
    413 	if (sc->set_modem_control == NULL)
    414 		sc->set_modem_control = sscom_set_modem_control;
    415 	if (sc->read_modem_status == NULL)
    416 		sc->read_modem_status = sscom_read_modem_status;
    417 
    418 	/* Disable interrupts before configuring the device. */
    419 	sscom_disable_txrxint(sc);
    420 
    421 #ifdef KGDB
    422 	/*
    423 	 * Allow kgdb to "take over" this port.  If this is
    424 	 * the kgdb device, it has exclusive use.
    425 	 */
    426 	if (unit == sscom_kgdb_unit) {
    427 		SET(sc->sc_hwflags, SSCOM_HW_KGDB);
    428 		sc->sc_ucon = UCON_DEBUGPORT;
    429 	}
    430 #endif
    431 
    432 	if (unit == sscomconsunit) {
    433 		sscomconsattached = 1;
    434 
    435 		sscomconstag = iot;
    436 		sscomconsioh = ioh;
    437 
    438 		/* Make sure the console is always "hardwired". */
    439 		delay(1000);			/* XXX: wait for output to finish */
    440 		SET(sc->sc_hwflags, SSCOM_HW_CONSOLE);
    441 		SET(sc->sc_swflags, TIOCFLAG_SOFTCAR);
    442 
    443 		sc->sc_ucon = UCON_DEBUGPORT;
    444 	}
    445 
    446 	bus_space_write_1(iot, ioh, SSCOM_UFCON,
    447 	    UFCON_TXTRIGGER_8|UFCON_RXTRIGGER_8|UFCON_FIFO_ENABLE|
    448 	    UFCON_TXFIFO_RESET|UFCON_RXFIFO_RESET);
    449 
    450 	bus_space_write_1(iot, ioh, SSCOM_UCON, sc->sc_ucon);
    451 
    452 #ifdef KGDB
    453 	if (ISSET(sc->sc_hwflags, SSCOM_HW_KGDB)) {
    454 		sscom_kgdb_attached = 1;
    455 		printf("%s: kgdb\n", sc->sc_dev.dv_xname);
    456 		sscom_enable_debugport(sc);
    457 		return;
    458 	}
    459 #endif
    460 
    461 
    462 
    463 	tp = ttymalloc();
    464 	tp->t_oproc = sscomstart;
    465 	tp->t_param = sscomparam;
    466 	tp->t_hwiflow = sscomhwiflow;
    467 
    468 	sc->sc_tty = tp;
    469 	sc->sc_rbuf = malloc(sscom_rbuf_size << 1, M_DEVBUF, M_NOWAIT);
    470 	sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
    471 	sc->sc_rbavail = sscom_rbuf_size;
    472 	if (sc->sc_rbuf == NULL) {
    473 		printf("%s: unable to allocate ring buffer\n",
    474 		    sc->sc_dev.dv_xname);
    475 		return;
    476 	}
    477 	sc->sc_ebuf = sc->sc_rbuf + (sscom_rbuf_size << 1);
    478 
    479 	tty_attach(tp);
    480 
    481 	if (ISSET(sc->sc_hwflags, SSCOM_HW_CONSOLE)) {
    482 		int maj;
    483 
    484 		/* locate the major number */
    485 		maj = cdevsw_lookup_major(&sscom_cdevsw);
    486 
    487 		cn_tab->cn_dev = makedev(maj, device_unit(&sc->sc_dev));
    488 
    489 		printf("%s: console (major=%d)\n", sc->sc_dev.dv_xname, maj);
    490 	}
    491 
    492 
    493 	sc->sc_si = softint_establish(SOFTINT_SERIAL, sscomsoft, sc);
    494 
    495 #if NRND > 0 && defined(RND_COM)
    496 	rnd_attach_source(&sc->rnd_source, sc->sc_dev.dv_xname,
    497 			  RND_TYPE_TTY, 0);
    498 #endif
    499 
    500 	/* if there are no enable/disable functions, assume the device
    501 	   is always enabled */
    502 
    503 	if (ISSET(sc->sc_hwflags, SSCOM_HW_CONSOLE))
    504 		sscom_enable_debugport(sc);
    505 	else
    506 		sscom_disable_txrxint(sc);
    507 
    508 	SET(sc->sc_hwflags, SSCOM_HW_DEV_OK);
    509 }
    510 
    511 int
    512 sscom_detach(device_t self, int flags)
    513 {
    514 	struct sscom_softc *sc = device_private(self);
    515 
    516 	if (sc->sc_hwflags & (SSCOM_HW_CONSOLE|SSCOM_HW_KGDB))
    517 		return EBUSY;
    518 
    519 	return 0;
    520 }
    521 
    522 int
    523 sscom_activate(device_t self, enum devact act)
    524 {
    525 #ifdef notyet
    526 	struct sscom_softc *sc = device_private(self);
    527 #endif
    528 
    529 	switch (act) {
    530 	case DVACT_DEACTIVATE:
    531 #ifdef notyet
    532 		sc->enabled = 0;
    533 #endif
    534 		return 0;
    535 	default:
    536 		return EOPNOTSUPP;
    537 	}
    538 }
    539 
    540 void
    541 sscom_shutdown(struct sscom_softc *sc)
    542 {
    543 #ifdef notyet
    544 	struct tty *tp = sc->sc_tty;
    545 	int s;
    546 
    547 	s = splserial();
    548 	SSCOM_LOCK(sc);
    549 
    550 	/* If we were asserting flow control, then deassert it. */
    551 	SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
    552 	sscom_hwiflow(sc);
    553 
    554 	/* Clear any break condition set with TIOCSBRK. */
    555 	sscom_break(sc, 0);
    556 
    557 	/*
    558 	 * Hang up if necessary.  Wait a bit, so the other side has time to
    559 	 * notice even if we immediately open the port again.
    560 	 * Avoid tsleeping above splhigh().
    561 	 */
    562 	if (ISSET(tp->t_cflag, HUPCL)) {
    563 		sscom_modem(sc, 0);
    564 		SSCOM_UNLOCK(sc);
    565 		splx(s);
    566 		/* XXX tsleep will only timeout */
    567 		(void) tsleep(sc, TTIPRI, ttclos, hz);
    568 		s = splserial();
    569 		SSCOM_LOCK(sc);
    570 	}
    571 
    572 	if (ISSET(sc->sc_hwflags, SSCOM_HW_CONSOLE))
    573 		/* interrupt on break */
    574 		sc->sc_ucon = UCON_DEBUGPORT;
    575 	else
    576 		sc->sc_ucon = 0;
    577 	bus_space_write_2(sc->sc_iot, sc->sc_ioh, SSCOM_UCON, sc->sc_ucon);
    578 
    579 #ifdef DIAGNOSTIC
    580 	if (!sc->enabled)
    581 		panic("sscom_shutdown: not enabled?");
    582 #endif
    583 	sc->enabled = 0;
    584 	SSCOM_UNLOCK(sc);
    585 	splx(s);
    586 #endif
    587 }
    588 
    589 int
    590 sscomopen(dev_t dev, int flag, int mode, struct lwp *l)
    591 {
    592 	struct sscom_softc *sc;
    593 	struct tty *tp;
    594 	int s, s2;
    595 	int error;
    596 
    597 	sc = device_lookup_private(&sscom_cd, SSCOMUNIT(dev));
    598 	if (sc == NULL || !ISSET(sc->sc_hwflags, SSCOM_HW_DEV_OK) ||
    599 		sc->sc_rbuf == NULL)
    600 		return ENXIO;
    601 
    602 	if (!device_is_active(&sc->sc_dev))
    603 		return ENXIO;
    604 
    605 #ifdef KGDB
    606 	/*
    607 	 * If this is the kgdb port, no other use is permitted.
    608 	 */
    609 	if (ISSET(sc->sc_hwflags, SSCOM_HW_KGDB))
    610 		return EBUSY;
    611 #endif
    612 
    613 	tp = sc->sc_tty;
    614 
    615 	if (kauth_authorize_device_tty(l->l_cred, KAUTH_DEVICE_TTY_OPEN, tp))
    616 		return (EBUSY);
    617 
    618 	s = spltty();
    619 
    620 	/*
    621 	 * Do the following iff this is a first open.
    622 	 */
    623 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
    624 		struct termios t;
    625 
    626 		tp->t_dev = dev;
    627 
    628 		s2 = splserial();
    629 		SSCOM_LOCK(sc);
    630 
    631 		/* Turn on interrupts. */
    632 		sscom_enable_txrxint(sc);
    633 
    634 		/* Fetch the current modem control status, needed later. */
    635 		sc->sc_msts = sc->read_modem_status(sc);
    636 
    637 #if 0
    638 		/* Clear PPS capture state on first open. */
    639 		sc->sc_ppsmask = 0;
    640 		sc->ppsparam.mode = 0;
    641 #endif
    642 
    643 		SSCOM_UNLOCK(sc);
    644 		splx(s2);
    645 
    646 		/*
    647 		 * Initialize the termios status to the defaults.  Add in the
    648 		 * sticky bits from TIOCSFLAGS.
    649 		 */
    650 		t.c_ispeed = 0;
    651 		if (ISSET(sc->sc_hwflags, SSCOM_HW_CONSOLE)) {
    652 			t.c_ospeed = sscomconsrate;
    653 			t.c_cflag = sscomconscflag;
    654 		} else {
    655 			t.c_ospeed = TTYDEF_SPEED;
    656 			t.c_cflag = TTYDEF_CFLAG;
    657 		}
    658 		if (ISSET(sc->sc_swflags, TIOCFLAG_CLOCAL))
    659 			SET(t.c_cflag, CLOCAL);
    660 		if (ISSET(sc->sc_swflags, TIOCFLAG_CRTSCTS))
    661 			SET(t.c_cflag, CRTSCTS);
    662 		if (ISSET(sc->sc_swflags, TIOCFLAG_MDMBUF))
    663 			SET(t.c_cflag, MDMBUF);
    664 		/* Make sure sscomparam() will do something. */
    665 		tp->t_ospeed = 0;
    666 		(void) sscomparam(tp, &t);
    667 		tp->t_iflag = TTYDEF_IFLAG;
    668 		tp->t_oflag = TTYDEF_OFLAG;
    669 		tp->t_lflag = TTYDEF_LFLAG;
    670 		ttychars(tp);
    671 		ttsetwater(tp);
    672 
    673 		s2 = splserial();
    674 		SSCOM_LOCK(sc);
    675 
    676 		/*
    677 		 * Turn on DTR.  We must always do this, even if carrier is not
    678 		 * present, because otherwise we'd have to use TIOCSDTR
    679 		 * immediately after setting CLOCAL, which applications do not
    680 		 * expect.  We always assert DTR while the device is open
    681 		 * unless explicitly requested to deassert it.
    682 		 */
    683 		sscom_modem(sc, 1);
    684 
    685 		/* Clear the input ring, and unblock. */
    686 		sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
    687 		sc->sc_rbavail = sscom_rbuf_size;
    688 		sscom_iflush(sc);
    689 		CLR(sc->sc_rx_flags, RX_ANY_BLOCK);
    690 		sscom_hwiflow(sc);
    691 
    692 		if (sscom_debug)
    693 			sscomstatus(sc, "sscomopen  ");
    694 
    695 		SSCOM_UNLOCK(sc);
    696 		splx(s2);
    697 	}
    698 
    699 	splx(s);
    700 
    701 	error = ttyopen(tp, SSCOMDIALOUT(dev), ISSET(flag, O_NONBLOCK));
    702 	if (error)
    703 		goto bad;
    704 
    705 	error = (*tp->t_linesw->l_open)(dev, tp);
    706 	if (error)
    707 		goto bad;
    708 
    709 	return 0;
    710 
    711 bad:
    712 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
    713 		/*
    714 		 * We failed to open the device, and nobody else had it opened.
    715 		 * Clean up the state as appropriate.
    716 		 */
    717 		sscom_shutdown(sc);
    718 	}
    719 
    720 	return error;
    721 }
    722 
    723 int
    724 sscomclose(dev_t dev, int flag, int mode, struct lwp *l)
    725 {
    726 	struct sscom_softc *sc = device_lookup_private(&sscom_cd, SSCOMUNIT(dev));
    727 	struct tty *tp = sc->sc_tty;
    728 
    729 	/* XXX This is for cons.c. */
    730 	if (!ISSET(tp->t_state, TS_ISOPEN))
    731 		return 0;
    732 
    733 	(*tp->t_linesw->l_close)(tp, flag);
    734 	ttyclose(tp);
    735 
    736 	if (SSCOM_ISALIVE(sc) == 0)
    737 		return 0;
    738 
    739 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
    740 		/*
    741 		 * Although we got a last close, the device may still be in
    742 		 * use; e.g. if this was the dialout node, and there are still
    743 		 * processes waiting for carrier on the non-dialout node.
    744 		 */
    745 		sscom_shutdown(sc);
    746 	}
    747 
    748 	return 0;
    749 }
    750 
    751 int
    752 sscomread(dev_t dev, struct uio *uio, int flag)
    753 {
    754 	struct sscom_softc *sc = device_lookup_private(&sscom_cd, SSCOMUNIT(dev));
    755 	struct tty *tp = sc->sc_tty;
    756 
    757 	if (SSCOM_ISALIVE(sc) == 0)
    758 		return EIO;
    759 
    760 	return (*tp->t_linesw->l_read)(tp, uio, flag);
    761 }
    762 
    763 int
    764 sscomwrite(dev_t dev, struct uio *uio, int flag)
    765 {
    766 	struct sscom_softc *sc = device_lookup_private(&sscom_cd, SSCOMUNIT(dev));
    767 	struct tty *tp = sc->sc_tty;
    768 
    769 	if (SSCOM_ISALIVE(sc) == 0)
    770 		return EIO;
    771 
    772 	return (*tp->t_linesw->l_write)(tp, uio, flag);
    773 }
    774 
    775 int
    776 sscompoll(dev_t dev, int events, struct lwp *l)
    777 {
    778 	struct sscom_softc *sc = device_lookup_private(&sscom_cd, SSCOMUNIT(dev));
    779 	struct tty *tp = sc->sc_tty;
    780 
    781 	if (SSCOM_ISALIVE(sc) == 0)
    782 		return EIO;
    783 
    784 	return (*tp->t_linesw->l_poll)(tp, events, l);
    785 }
    786 
    787 struct tty *
    788 sscomtty(dev_t dev)
    789 {
    790 	struct sscom_softc *sc = device_lookup_private(&sscom_cd, SSCOMUNIT(dev));
    791 	struct tty *tp = sc->sc_tty;
    792 
    793 	return tp;
    794 }
    795 
    796 int
    797 sscomioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
    798 {
    799 	struct sscom_softc *sc = device_lookup_private(&sscom_cd, SSCOMUNIT(dev));
    800 	struct tty *tp = sc->sc_tty;
    801 	int error;
    802 	int s;
    803 
    804 	if (SSCOM_ISALIVE(sc) == 0)
    805 		return EIO;
    806 
    807 	error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, l);
    808 	if (error != EPASSTHROUGH)
    809 		return error;
    810 
    811 	error = ttioctl(tp, cmd, data, flag, l);
    812 	if (error != EPASSTHROUGH)
    813 		return error;
    814 
    815 	error = 0;
    816 
    817 	s = splserial();
    818 	SSCOM_LOCK(sc);
    819 
    820 	switch (cmd) {
    821 	case TIOCSBRK:
    822 		sscom_break(sc, 1);
    823 		break;
    824 
    825 	case TIOCCBRK:
    826 		sscom_break(sc, 0);
    827 		break;
    828 
    829 	case TIOCSDTR:
    830 		sscom_modem(sc, 1);
    831 		break;
    832 
    833 	case TIOCCDTR:
    834 		sscom_modem(sc, 0);
    835 		break;
    836 
    837 	case TIOCGFLAGS:
    838 		*(int *)data = sc->sc_swflags;
    839 		break;
    840 
    841 	case TIOCSFLAGS:
    842 		error = kauth_authorize_device_tty(l->l_cred,
    843 		    KAUTH_DEVICE_TTY_PRIVSET, tp);
    844 		if (error)
    845 			break;
    846 		sc->sc_swflags = *(int *)data;
    847 		break;
    848 
    849 	case TIOCMSET:
    850 	case TIOCMBIS:
    851 	case TIOCMBIC:
    852 		tiocm_to_sscom(sc, cmd, *(int *)data);
    853 		break;
    854 
    855 	case TIOCMGET:
    856 		*(int *)data = sscom_to_tiocm(sc);
    857 		break;
    858 
    859 	default:
    860 		error = EPASSTHROUGH;
    861 		break;
    862 	}
    863 
    864 	SSCOM_UNLOCK(sc);
    865 	splx(s);
    866 
    867 	if (sscom_debug)
    868 		sscomstatus(sc, "sscomioctl ");
    869 
    870 	return error;
    871 }
    872 
    873 integrate void
    874 sscom_schedrx(struct sscom_softc *sc)
    875 {
    876 
    877 	sc->sc_rx_ready = 1;
    878 
    879 	/* Wake up the poller. */
    880 	softint_schedule(sc->sc_si);
    881 }
    882 
    883 static void
    884 sscom_break(struct sscom_softc *sc, int onoff)
    885 {
    886 
    887 	if (onoff)
    888 		SET(sc->sc_ucon, UCON_SBREAK);
    889 	else
    890 		CLR(sc->sc_ucon, UCON_SBREAK);
    891 
    892 	if (!sc->sc_heldchange) {
    893 		if (sc->sc_tx_busy) {
    894 			sc->sc_heldtbc = sc->sc_tbc;
    895 			sc->sc_tbc = 0;
    896 			sc->sc_heldchange = 1;
    897 		} else
    898 			sscom_loadchannelregs(sc);
    899 	}
    900 }
    901 
    902 static void
    903 sscom_modem(struct sscom_softc *sc, int onoff)
    904 {
    905 	if (onoff)
    906 		SET(sc->sc_umcon, UMCON_DTR);
    907 	else
    908 		CLR(sc->sc_umcon, UMCON_DTR);
    909 
    910 	if (!sc->sc_heldchange) {
    911 		if (sc->sc_tx_busy) {
    912 			sc->sc_heldtbc = sc->sc_tbc;
    913 			sc->sc_tbc = 0;
    914 			sc->sc_heldchange = 1;
    915 		} else
    916 			sscom_loadchannelregs(sc);
    917 	}
    918 }
    919 
    920 static void
    921 tiocm_to_sscom(struct sscom_softc *sc, u_long how, int ttybits)
    922 {
    923 	u_char sscombits;
    924 
    925 	sscombits = 0;
    926 	if (ISSET(ttybits, TIOCM_DTR))
    927 		sscombits = UMCON_DTR;
    928 	if (ISSET(ttybits, TIOCM_RTS))
    929 		SET(sscombits, UMCON_RTS);
    930 
    931 	switch (how) {
    932 	case TIOCMBIC:
    933 		CLR(sc->sc_umcon, sscombits);
    934 		break;
    935 
    936 	case TIOCMBIS:
    937 		SET(sc->sc_umcon, sscombits);
    938 		break;
    939 
    940 	case TIOCMSET:
    941 		CLR(sc->sc_umcon, UMCON_DTR);
    942 		SET(sc->sc_umcon, sscombits);
    943 		break;
    944 	}
    945 
    946 	if (!sc->sc_heldchange) {
    947 		if (sc->sc_tx_busy) {
    948 			sc->sc_heldtbc = sc->sc_tbc;
    949 			sc->sc_tbc = 0;
    950 			sc->sc_heldchange = 1;
    951 		} else
    952 			sscom_loadchannelregs(sc);
    953 	}
    954 }
    955 
    956 static int
    957 sscom_to_tiocm(struct sscom_softc *sc)
    958 {
    959 	u_char sscombits;
    960 	int ttybits = 0;
    961 
    962 	sscombits = sc->sc_umcon;
    963 #if 0
    964 	if (ISSET(sscombits, MCR_DTR))
    965 		SET(ttybits, TIOCM_DTR);
    966 #endif
    967 	if (ISSET(sscombits, UMCON_RTS))
    968 		SET(ttybits, TIOCM_RTS);
    969 
    970 	sscombits = sc->sc_msts;
    971 	if (ISSET(sscombits, MSTS_DCD))
    972 		SET(ttybits, TIOCM_CD);
    973 	if (ISSET(sscombits, MSTS_DSR))
    974 		SET(ttybits, TIOCM_DSR);
    975 	if (ISSET(sscombits, MSTS_CTS))
    976 		SET(ttybits, TIOCM_CTS);
    977 
    978 	if (sc->sc_ucon != 0)
    979 		SET(ttybits, TIOCM_LE);
    980 
    981 	return ttybits;
    982 }
    983 
    984 static int
    985 cflag2lcr(tcflag_t cflag)
    986 {
    987 	u_char lcr = ULCON_PARITY_NONE;
    988 
    989 	switch (cflag & (PARENB|PARODD)) {
    990 	case PARENB|PARODD: lcr = ULCON_PARITY_ODD; break;
    991 	case PARENB: lcr = ULCON_PARITY_EVEN;
    992 	}
    993 
    994 	switch (ISSET(cflag, CSIZE)) {
    995 	case CS5:
    996 		SET(lcr, ULCON_LENGTH_5);
    997 		break;
    998 	case CS6:
    999 		SET(lcr, ULCON_LENGTH_6);
   1000 		break;
   1001 	case CS7:
   1002 		SET(lcr, ULCON_LENGTH_7);
   1003 		break;
   1004 	case CS8:
   1005 		SET(lcr, ULCON_LENGTH_8);
   1006 		break;
   1007 	}
   1008 	if (ISSET(cflag, CSTOPB))
   1009 		SET(lcr, ULCON_STOP);
   1010 
   1011 	return lcr;
   1012 }
   1013 
   1014 int
   1015 sscomparam(struct tty *tp, struct termios *t)
   1016 {
   1017 	struct sscom_softc *sc = device_lookup_private(&sscom_cd, SSCOMUNIT(tp->t_dev));
   1018 	int ospeed;
   1019 	u_char lcr;
   1020 	int s;
   1021 
   1022 	if (SSCOM_ISALIVE(sc) == 0)
   1023 		return EIO;
   1024 
   1025 	ospeed = sscomspeed(t->c_ospeed, sc->sc_frequency);
   1026 
   1027 	/* Check requested parameters. */
   1028 	if (ospeed < 0)
   1029 		return EINVAL;
   1030 	if (t->c_ispeed && t->c_ispeed != t->c_ospeed)
   1031 		return EINVAL;
   1032 
   1033 	/*
   1034 	 * For the console, always force CLOCAL and !HUPCL, so that the port
   1035 	 * is always active.
   1036 	 */
   1037 	if (ISSET(sc->sc_swflags, TIOCFLAG_SOFTCAR) ||
   1038 	    ISSET(sc->sc_hwflags, SSCOM_HW_CONSOLE)) {
   1039 		SET(t->c_cflag, CLOCAL);
   1040 		CLR(t->c_cflag, HUPCL);
   1041 	}
   1042 
   1043 	/*
   1044 	 * If there were no changes, don't do anything.  This avoids dropping
   1045 	 * input and improves performance when all we did was frob things like
   1046 	 * VMIN and VTIME.
   1047 	 */
   1048 	if (tp->t_ospeed == t->c_ospeed &&
   1049 	    tp->t_cflag == t->c_cflag)
   1050 		return 0;
   1051 
   1052 	lcr = cflag2lcr(t->c_cflag);
   1053 
   1054 	s = splserial();
   1055 	SSCOM_LOCK(sc);
   1056 
   1057 	sc->sc_ulcon = lcr;
   1058 
   1059 	/*
   1060 	 * If we're not in a mode that assumes a connection is present, then
   1061 	 * ignore carrier changes.
   1062 	 */
   1063 	if (ISSET(t->c_cflag, CLOCAL | MDMBUF))
   1064 		sc->sc_msr_dcd = 0;
   1065 	else
   1066 		sc->sc_msr_dcd = MSTS_DCD;
   1067 
   1068 	/*
   1069 	 * Set the flow control pins depending on the current flow control
   1070 	 * mode.
   1071 	 */
   1072 	if (ISSET(t->c_cflag, CRTSCTS)) {
   1073 		sc->sc_mcr_dtr = UMCON_DTR;
   1074 		sc->sc_mcr_rts = UMCON_RTS;
   1075 		sc->sc_msr_cts = MSTS_CTS;
   1076 	}
   1077 	else if (ISSET(t->c_cflag, MDMBUF)) {
   1078 		/*
   1079 		 * For DTR/DCD flow control, make sure we don't toggle DTR for
   1080 		 * carrier detection.
   1081 		 */
   1082 		sc->sc_mcr_dtr = 0;
   1083 		sc->sc_mcr_rts = UMCON_DTR;
   1084 		sc->sc_msr_cts = MSTS_DCD;
   1085 	}
   1086 	else {
   1087 		/*
   1088 		 * If no flow control, then always set RTS.  This will make
   1089 		 * the other side happy if it mistakenly thinks we're doing
   1090 		 * RTS/CTS flow control.
   1091 		 */
   1092 		sc->sc_mcr_dtr = UMCON_DTR | UMCON_RTS;
   1093 		sc->sc_mcr_rts = 0;
   1094 		sc->sc_msr_cts = 0;
   1095 		if (ISSET(sc->sc_umcon, UMCON_DTR))
   1096 			SET(sc->sc_umcon, UMCON_RTS);
   1097 		else
   1098 			CLR(sc->sc_umcon, UMCON_RTS);
   1099 	}
   1100 	sc->sc_msr_mask = sc->sc_msr_cts | sc->sc_msr_dcd;
   1101 
   1102 	if (ospeed == 0)
   1103 		CLR(sc->sc_umcon, sc->sc_mcr_dtr);
   1104 	else
   1105 		SET(sc->sc_umcon, sc->sc_mcr_dtr);
   1106 
   1107 	sc->sc_ubrdiv = ospeed;
   1108 
   1109 	/* And copy to tty. */
   1110 	tp->t_ispeed = 0;
   1111 	tp->t_ospeed = t->c_ospeed;
   1112 	tp->t_cflag = t->c_cflag;
   1113 
   1114 	if (!sc->sc_heldchange) {
   1115 		if (sc->sc_tx_busy) {
   1116 			sc->sc_heldtbc = sc->sc_tbc;
   1117 			sc->sc_tbc = 0;
   1118 			sc->sc_heldchange = 1;
   1119 		} else
   1120 			sscom_loadchannelregs(sc);
   1121 	}
   1122 
   1123 	if (!ISSET(t->c_cflag, CHWFLOW)) {
   1124 		/* Disable the high water mark. */
   1125 		sc->sc_r_hiwat = 0;
   1126 		sc->sc_r_lowat = 0;
   1127 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
   1128 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
   1129 			sscom_schedrx(sc);
   1130 		}
   1131 		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED)) {
   1132 			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED);
   1133 			sscom_hwiflow(sc);
   1134 		}
   1135 	} else {
   1136 		sc->sc_r_hiwat = sscom_rbuf_hiwat;
   1137 		sc->sc_r_lowat = sscom_rbuf_lowat;
   1138 	}
   1139 
   1140 	SSCOM_UNLOCK(sc);
   1141 	splx(s);
   1142 
   1143 	/*
   1144 	 * Update the tty layer's idea of the carrier bit, in case we changed
   1145 	 * CLOCAL or MDMBUF.  We don't hang up here; we only do that by
   1146 	 * explicit request.
   1147 	 */
   1148 	(void) (*tp->t_linesw->l_modem)(tp, ISSET(sc->sc_msts, MSTS_DCD));
   1149 
   1150 	if (sscom_debug)
   1151 		sscomstatus(sc, "sscomparam ");
   1152 
   1153 	if (!ISSET(t->c_cflag, CHWFLOW)) {
   1154 		if (sc->sc_tx_stopped) {
   1155 			sc->sc_tx_stopped = 0;
   1156 			sscomstart(tp);
   1157 		}
   1158 	}
   1159 
   1160 	return 0;
   1161 }
   1162 
   1163 static void
   1164 sscom_iflush(struct sscom_softc *sc)
   1165 {
   1166 	bus_space_tag_t iot = sc->sc_iot;
   1167 	bus_space_handle_t ioh = sc->sc_ioh;
   1168 	int timo;
   1169 
   1170 
   1171 	timo = 50000;
   1172 	/* flush any pending I/O */
   1173 	while ( sscom_rxrdy(iot, ioh) && --timo)
   1174 		(void)sscom_getc(iot,ioh);
   1175 #ifdef DIAGNOSTIC
   1176 	if (!timo)
   1177 		printf("%s: sscom_iflush timeout\n", sc->sc_dev.dv_xname);
   1178 #endif
   1179 }
   1180 
   1181 static void
   1182 sscom_loadchannelregs(struct sscom_softc *sc)
   1183 {
   1184 	bus_space_tag_t iot = sc->sc_iot;
   1185 	bus_space_handle_t ioh = sc->sc_ioh;
   1186 
   1187 	/* XXXXX necessary? */
   1188 	sscom_iflush(sc);
   1189 
   1190 	bus_space_write_2(iot, ioh, SSCOM_UCON, 0);
   1191 
   1192 #if 0
   1193 	if (ISSET(sc->sc_hwflags, COM_HW_FLOW)) {
   1194 		bus_space_write_1(iot, ioh, com_lcr, LCR_EERS);
   1195 		bus_space_write_1(iot, ioh, com_efr, sc->sc_efr);
   1196 	}
   1197 #endif
   1198 
   1199 	bus_space_write_2(iot, ioh, SSCOM_UBRDIV, sc->sc_ubrdiv);
   1200 	bus_space_write_1(iot, ioh, SSCOM_ULCON, sc->sc_ulcon);
   1201 	sc->set_modem_control(sc);
   1202 	bus_space_write_2(iot, ioh, SSCOM_UCON, sc->sc_ucon);
   1203 }
   1204 
   1205 static int
   1206 sscomhwiflow(struct tty *tp, int block)
   1207 {
   1208 	struct sscom_softc *sc = device_lookup_private(&sscom_cd, SSCOMUNIT(tp->t_dev));
   1209 	int s;
   1210 
   1211 	if (SSCOM_ISALIVE(sc) == 0)
   1212 		return 0;
   1213 
   1214 	if (sc->sc_mcr_rts == 0)
   1215 		return 0;
   1216 
   1217 	s = splserial();
   1218 	SSCOM_LOCK(sc);
   1219 
   1220 	if (block) {
   1221 		if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
   1222 			SET(sc->sc_rx_flags, RX_TTY_BLOCKED);
   1223 			sscom_hwiflow(sc);
   1224 		}
   1225 	} else {
   1226 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
   1227 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
   1228 			sscom_schedrx(sc);
   1229 		}
   1230 		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
   1231 			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED);
   1232 			sscom_hwiflow(sc);
   1233 		}
   1234 	}
   1235 
   1236 	SSCOM_UNLOCK(sc);
   1237 	splx(s);
   1238 	return 1;
   1239 }
   1240 
   1241 /*
   1242  * (un)block input via hw flowcontrol
   1243  */
   1244 static void
   1245 sscom_hwiflow(struct sscom_softc *sc)
   1246 {
   1247 	if (sc->sc_mcr_rts == 0)
   1248 		return;
   1249 
   1250 	if (ISSET(sc->sc_rx_flags, RX_ANY_BLOCK)) {
   1251 		CLR(sc->sc_umcon, sc->sc_mcr_rts);
   1252 		CLR(sc->sc_mcr_active, sc->sc_mcr_rts);
   1253 	} else {
   1254 		SET(sc->sc_umcon, sc->sc_mcr_rts);
   1255 		SET(sc->sc_mcr_active, sc->sc_mcr_rts);
   1256 	}
   1257 	sc->set_modem_control(sc);
   1258 }
   1259 
   1260 
   1261 void
   1262 sscomstart(struct tty *tp)
   1263 {
   1264 	struct sscom_softc *sc = device_lookup_private(&sscom_cd, SSCOMUNIT(tp->t_dev));
   1265 	int s;
   1266 
   1267 	if (SSCOM_ISALIVE(sc) == 0)
   1268 		return;
   1269 
   1270 	s = spltty();
   1271 	if (ISSET(tp->t_state, TS_BUSY | TS_TIMEOUT | TS_TTSTOP))
   1272 		goto out;
   1273 	if (sc->sc_tx_stopped)
   1274 		goto out;
   1275 	if (!ttypull(tp))
   1276 		goto out;
   1277 
   1278 	/* Grab the first contiguous region of buffer space. */
   1279 	{
   1280 		u_char *tba;
   1281 		int tbc;
   1282 
   1283 		tba = tp->t_outq.c_cf;
   1284 		tbc = ndqb(&tp->t_outq, 0);
   1285 
   1286 		(void)splserial();
   1287 		SSCOM_LOCK(sc);
   1288 
   1289 		sc->sc_tba = tba;
   1290 		sc->sc_tbc = tbc;
   1291 	}
   1292 
   1293 	SET(tp->t_state, TS_BUSY);
   1294 	sc->sc_tx_busy = 1;
   1295 
   1296 	/* Output the first chunk of the contiguous buffer. */
   1297 	sscom_output_chunk(sc);
   1298 
   1299 	/* Enable transmit completion interrupts if necessary. */
   1300 	if ((sc->sc_hwflags & SSCOM_HW_TXINT) == 0)
   1301 		sscom_enable_txint(sc);
   1302 
   1303 	SSCOM_UNLOCK(sc);
   1304 out:
   1305 	splx(s);
   1306 	return;
   1307 }
   1308 
   1309 /*
   1310  * Stop output on a line.
   1311  */
   1312 void
   1313 sscomstop(struct tty *tp, int flag)
   1314 {
   1315 	struct sscom_softc *sc = device_lookup_private(&sscom_cd, SSCOMUNIT(tp->t_dev));
   1316 	int s;
   1317 
   1318 	s = splserial();
   1319 	SSCOM_LOCK(sc);
   1320 	if (ISSET(tp->t_state, TS_BUSY)) {
   1321 		/* Stop transmitting at the next chunk. */
   1322 		sc->sc_tbc = 0;
   1323 		sc->sc_heldtbc = 0;
   1324 		if (!ISSET(tp->t_state, TS_TTSTOP))
   1325 			SET(tp->t_state, TS_FLUSH);
   1326 	}
   1327 	SSCOM_UNLOCK(sc);
   1328 	splx(s);
   1329 }
   1330 
   1331 void
   1332 sscomdiag(void *arg)
   1333 {
   1334 	struct sscom_softc *sc = arg;
   1335 	int overflows, floods;
   1336 	int s;
   1337 
   1338 	s = splserial();
   1339 	SSCOM_LOCK(sc);
   1340 	overflows = sc->sc_overflows;
   1341 	sc->sc_overflows = 0;
   1342 	floods = sc->sc_floods;
   1343 	sc->sc_floods = 0;
   1344 	sc->sc_errors = 0;
   1345 	SSCOM_UNLOCK(sc);
   1346 	splx(s);
   1347 
   1348 	log(LOG_WARNING, "%s: %d silo overflow%s, %d ibuf flood%s\n",
   1349 	    sc->sc_dev.dv_xname,
   1350 	    overflows, overflows == 1 ? "" : "s",
   1351 	    floods, floods == 1 ? "" : "s");
   1352 }
   1353 
   1354 integrate void
   1355 sscom_rxsoft(struct sscom_softc *sc, struct tty *tp)
   1356 {
   1357 	int (*rint) (int, struct tty *) = tp->t_linesw->l_rint;
   1358 	u_char *get, *end;
   1359 	u_int cc, scc;
   1360 	u_char rsr;
   1361 	int code;
   1362 	int s;
   1363 
   1364 	end = sc->sc_ebuf;
   1365 	get = sc->sc_rbget;
   1366 	scc = cc = sscom_rbuf_size - sc->sc_rbavail;
   1367 
   1368 	if (cc == sscom_rbuf_size) {
   1369 		sc->sc_floods++;
   1370 		if (sc->sc_errors++ == 0)
   1371 			callout_reset(&sc->sc_diag_callout, 60 * hz,
   1372 			    sscomdiag, sc);
   1373 	}
   1374 
   1375 	while (cc) {
   1376 		code = get[0];
   1377 		rsr = get[1];
   1378 		if (rsr) {
   1379 			if (ISSET(rsr, UERSTAT_OVERRUN)) {
   1380 				sc->sc_overflows++;
   1381 				if (sc->sc_errors++ == 0)
   1382 					callout_reset(&sc->sc_diag_callout,
   1383 					    60 * hz, sscomdiag, sc);
   1384 			}
   1385 			if (ISSET(rsr, UERSTAT_BREAK | UERSTAT_FRAME))
   1386 				SET(code, TTY_FE);
   1387 			if (ISSET(rsr, UERSTAT_PARITY))
   1388 				SET(code, TTY_PE);
   1389 		}
   1390 		if ((*rint)(code, tp) == -1) {
   1391 			/*
   1392 			 * The line discipline's buffer is out of space.
   1393 			 */
   1394 			if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
   1395 				/*
   1396 				 * We're either not using flow control, or the
   1397 				 * line discipline didn't tell us to block for
   1398 				 * some reason.  Either way, we have no way to
   1399 				 * know when there's more space available, so
   1400 				 * just drop the rest of the data.
   1401 				 */
   1402 				get += cc << 1;
   1403 				if (get >= end)
   1404 					get -= sscom_rbuf_size << 1;
   1405 				cc = 0;
   1406 			} else {
   1407 				/*
   1408 				 * Don't schedule any more receive processing
   1409 				 * until the line discipline tells us there's
   1410 				 * space available (through sscomhwiflow()).
   1411 				 * Leave the rest of the data in the input
   1412 				 * buffer.
   1413 				 */
   1414 				SET(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
   1415 			}
   1416 			break;
   1417 		}
   1418 		get += 2;
   1419 		if (get >= end)
   1420 			get = sc->sc_rbuf;
   1421 		cc--;
   1422 	}
   1423 
   1424 	if (cc != scc) {
   1425 		sc->sc_rbget = get;
   1426 		s = splserial();
   1427 		SSCOM_LOCK(sc);
   1428 
   1429 		cc = sc->sc_rbavail += scc - cc;
   1430 		/* Buffers should be ok again, release possible block. */
   1431 		if (cc >= sc->sc_r_lowat) {
   1432 			if (ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
   1433 				CLR(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
   1434 				sscom_enable_rxint(sc);
   1435 				sc->sc_ucon |= UCON_ERRINT;
   1436 				bus_space_write_2(sc->sc_iot, sc->sc_ioh, SSCOM_UCON,
   1437 						  sc->sc_ucon);
   1438 
   1439 			}
   1440 			if (ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED)) {
   1441 				CLR(sc->sc_rx_flags, RX_IBUF_BLOCKED);
   1442 				sscom_hwiflow(sc);
   1443 			}
   1444 		}
   1445 		SSCOM_UNLOCK(sc);
   1446 		splx(s);
   1447 	}
   1448 }
   1449 
   1450 integrate void
   1451 sscom_txsoft(struct sscom_softc *sc, struct tty *tp)
   1452 {
   1453 
   1454 	CLR(tp->t_state, TS_BUSY);
   1455 	if (ISSET(tp->t_state, TS_FLUSH))
   1456 		CLR(tp->t_state, TS_FLUSH);
   1457 	else
   1458 		ndflush(&tp->t_outq, (int)(sc->sc_tba - tp->t_outq.c_cf));
   1459 	(*tp->t_linesw->l_start)(tp);
   1460 }
   1461 
   1462 integrate void
   1463 sscom_stsoft(struct sscom_softc *sc, struct tty *tp)
   1464 {
   1465 	u_char msr, delta;
   1466 	int s;
   1467 
   1468 	s = splserial();
   1469 	SSCOM_LOCK(sc);
   1470 	msr = sc->sc_msts;
   1471 	delta = sc->sc_msr_delta;
   1472 	sc->sc_msr_delta = 0;
   1473 	SSCOM_UNLOCK(sc);
   1474 	splx(s);
   1475 
   1476 	if (ISSET(delta, sc->sc_msr_dcd)) {
   1477 		/*
   1478 		 * Inform the tty layer that carrier detect changed.
   1479 		 */
   1480 		(void) (*tp->t_linesw->l_modem)(tp, ISSET(msr, MSTS_DCD));
   1481 	}
   1482 
   1483 	if (ISSET(delta, sc->sc_msr_cts)) {
   1484 		/* Block or unblock output according to flow control. */
   1485 		if (ISSET(msr, sc->sc_msr_cts)) {
   1486 			sc->sc_tx_stopped = 0;
   1487 			(*tp->t_linesw->l_start)(tp);
   1488 		} else {
   1489 			sc->sc_tx_stopped = 1;
   1490 		}
   1491 	}
   1492 
   1493 	if (sscom_debug)
   1494 		sscomstatus(sc, "sscom_stsoft");
   1495 }
   1496 
   1497 void
   1498 sscomsoft(void *arg)
   1499 {
   1500 	struct sscom_softc *sc = arg;
   1501 	struct tty *tp;
   1502 
   1503 	if (SSCOM_ISALIVE(sc) == 0)
   1504 		return;
   1505 
   1506 	{
   1507 		tp = sc->sc_tty;
   1508 
   1509 		if (sc->sc_rx_ready) {
   1510 			sc->sc_rx_ready = 0;
   1511 			sscom_rxsoft(sc, tp);
   1512 		}
   1513 
   1514 		if (sc->sc_st_check) {
   1515 			sc->sc_st_check = 0;
   1516 			sscom_stsoft(sc, tp);
   1517 		}
   1518 
   1519 		if (sc->sc_tx_done) {
   1520 			sc->sc_tx_done = 0;
   1521 			sscom_txsoft(sc, tp);
   1522 		}
   1523 	}
   1524 }
   1525 
   1526 
   1527 int
   1528 sscomrxintr(void *arg)
   1529 {
   1530 	struct sscom_softc *sc = arg;
   1531 	bus_space_tag_t iot = sc->sc_iot;
   1532 	bus_space_handle_t ioh = sc->sc_ioh;
   1533 	u_char *put, *end;
   1534 	u_int cc;
   1535 
   1536 	if (SSCOM_ISALIVE(sc) == 0)
   1537 		return 0;
   1538 
   1539 	SSCOM_LOCK(sc);
   1540 
   1541 	end = sc->sc_ebuf;
   1542 	put = sc->sc_rbput;
   1543 	cc = sc->sc_rbavail;
   1544 
   1545 	do {
   1546 		u_char	msts, delta;
   1547 		u_char  uerstat;
   1548 		uint16_t ufstat;
   1549 
   1550 		ufstat = bus_space_read_2(iot, ioh, SSCOM_UFSTAT);
   1551 
   1552 		/* XXX: break interrupt with no character? */
   1553 
   1554 		if ( (ufstat & (UFSTAT_RXCOUNT|UFSTAT_RXFULL)) &&
   1555 		    !ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
   1556 
   1557 			while (cc > 0) {
   1558 				int cn_trapped = 0;
   1559 
   1560 				/* get status and received character.
   1561 				   read status register first */
   1562 				uerstat = sscom_geterr(iot, ioh);
   1563 				put[0] = sscom_getc(iot, ioh);
   1564 
   1565 				if (ISSET(uerstat, UERSTAT_BREAK)) {
   1566 					int con_trapped = 0;
   1567 					cn_check_magic(sc->sc_tty->t_dev,
   1568 					    CNC_BREAK, sscom_cnm_state);
   1569 					if (con_trapped)
   1570 						continue;
   1571 #if defined(KGDB)
   1572 					if (ISSET(sc->sc_hwflags,
   1573 					    SSCOM_HW_KGDB)) {
   1574 						kgdb_connect(1);
   1575 						continue;
   1576 					}
   1577 #endif
   1578 				}
   1579 
   1580 				put[1] = uerstat;
   1581 				cn_check_magic(sc->sc_tty->t_dev,
   1582 					       put[0], sscom_cnm_state);
   1583 				if (!cn_trapped) {
   1584 					put += 2;
   1585 					if (put >= end)
   1586 						put = sc->sc_rbuf;
   1587 					cc--;
   1588 				}
   1589 
   1590 				ufstat = bus_space_read_2(iot, ioh, SSCOM_UFSTAT);
   1591 				if ( (ufstat & (UFSTAT_RXFULL|UFSTAT_RXCOUNT)) == 0 )
   1592 					break;
   1593 			}
   1594 
   1595 			/*
   1596 			 * Current string of incoming characters ended because
   1597 			 * no more data was available or we ran out of space.
   1598 			 * Schedule a receive event if any data was received.
   1599 			 * If we're out of space, turn off receive interrupts.
   1600 			 */
   1601 			sc->sc_rbput = put;
   1602 			sc->sc_rbavail = cc;
   1603 			if (!ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED))
   1604 				sc->sc_rx_ready = 1;
   1605 
   1606 			/*
   1607 			 * See if we are in danger of overflowing a buffer. If
   1608 			 * so, use hardware flow control to ease the pressure.
   1609 			 */
   1610 			if (!ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED) &&
   1611 			    cc < sc->sc_r_hiwat) {
   1612 				SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
   1613 				sscom_hwiflow(sc);
   1614 			}
   1615 
   1616 			/*
   1617 			 * If we're out of space, disable receive interrupts
   1618 			 * until the queue has drained a bit.
   1619 			 */
   1620 			if (!cc) {
   1621 				SET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
   1622 				sscom_disable_rxint(sc);
   1623 				sc->sc_ucon &= ~UCON_ERRINT;
   1624 				bus_space_write_2(iot, ioh, SSCOM_UCON, sc->sc_ucon);
   1625 			}
   1626 		}
   1627 
   1628 
   1629 		msts = sc->read_modem_status(sc);
   1630 		delta = msts ^ sc->sc_msts;
   1631 		sc->sc_msts = msts;
   1632 
   1633 #ifdef notyet
   1634 		/*
   1635 		 * Pulse-per-second (PSS) signals on edge of DCD?
   1636 		 * Process these even if line discipline is ignoring DCD.
   1637 		 */
   1638 		if (delta & sc->sc_ppsmask) {
   1639 			struct timeval tv;
   1640 		    	if ((msr & sc->sc_ppsmask) == sc->sc_ppsassert) {
   1641 				/* XXX nanotime() */
   1642 				microtime(&tv);
   1643 				TIMEVAL_TO_TIMESPEC(&tv,
   1644 				    &sc->ppsinfo.assert_timestamp);
   1645 				if (sc->ppsparam.mode & PPS_OFFSETASSERT) {
   1646 					timespecadd(&sc->ppsinfo.assert_timestamp,
   1647 					    &sc->ppsparam.assert_offset,
   1648 						    &sc->ppsinfo.assert_timestamp);
   1649 				}
   1650 
   1651 #ifdef PPS_SYNC
   1652 				if (sc->ppsparam.mode & PPS_HARDPPSONASSERT)
   1653 					hardpps(&tv, tv.tv_usec);
   1654 #endif
   1655 				sc->ppsinfo.assert_sequence++;
   1656 				sc->ppsinfo.current_mode = sc->ppsparam.mode;
   1657 
   1658 			} else if ((msr & sc->sc_ppsmask) == sc->sc_ppsclear) {
   1659 				/* XXX nanotime() */
   1660 				microtime(&tv);
   1661 				TIMEVAL_TO_TIMESPEC(&tv,
   1662 				    &sc->ppsinfo.clear_timestamp);
   1663 				if (sc->ppsparam.mode & PPS_OFFSETCLEAR) {
   1664 					timespecadd(&sc->ppsinfo.clear_timestamp,
   1665 					    &sc->ppsparam.clear_offset,
   1666 					    &sc->ppsinfo.clear_timestamp);
   1667 				}
   1668 
   1669 #ifdef PPS_SYNC
   1670 				if (sc->ppsparam.mode & PPS_HARDPPSONCLEAR)
   1671 					hardpps(&tv, tv.tv_usec);
   1672 #endif
   1673 				sc->ppsinfo.clear_sequence++;
   1674 				sc->ppsinfo.current_mode = sc->ppsparam.mode;
   1675 			}
   1676 		}
   1677 #endif
   1678 
   1679 		/*
   1680 		 * Process normal status changes
   1681 		 */
   1682 		if (ISSET(delta, sc->sc_msr_mask)) {
   1683 			SET(sc->sc_msr_delta, delta);
   1684 
   1685 			/*
   1686 			 * Stop output immediately if we lose the output
   1687 			 * flow control signal or carrier detect.
   1688 			 */
   1689 			if (ISSET(~msts, sc->sc_msr_mask)) {
   1690 				sc->sc_tbc = 0;
   1691 				sc->sc_heldtbc = 0;
   1692 #ifdef SSCOM_DEBUG
   1693 				if (sscom_debug)
   1694 					sscomstatus(sc, "sscomintr  ");
   1695 #endif
   1696 			}
   1697 
   1698 			sc->sc_st_check = 1;
   1699 		}
   1700 
   1701 		/*
   1702 		 * Done handling any receive interrupts.
   1703 		 */
   1704 
   1705 		/*
   1706 		 * If we've delayed a parameter change, do it
   1707 		 * now, and restart * output.
   1708 		 */
   1709 		if ((ufstat & UFSTAT_TXCOUNT) == 0) {
   1710 			/* XXX: we should check transmitter empty also */
   1711 
   1712 			if (sc->sc_heldchange) {
   1713 				sscom_loadchannelregs(sc);
   1714 				sc->sc_heldchange = 0;
   1715 				sc->sc_tbc = sc->sc_heldtbc;
   1716 				sc->sc_heldtbc = 0;
   1717 			}
   1718 		}
   1719 
   1720 
   1721 	} while (0);
   1722 
   1723 	SSCOM_UNLOCK(sc);
   1724 
   1725 	/* Wake up the poller. */
   1726 	softint_schedule(sc->sc_si);
   1727 
   1728 #if NRND > 0 && defined(RND_COM)
   1729 	rnd_add_uint32(&sc->rnd_source, iir | rsr);
   1730 #endif
   1731 
   1732 	return 1;
   1733 }
   1734 
   1735 int
   1736 sscomtxintr(void *arg)
   1737 {
   1738 	struct sscom_softc *sc = arg;
   1739 	bus_space_tag_t iot = sc->sc_iot;
   1740 	bus_space_handle_t ioh = sc->sc_ioh;
   1741 	uint16_t ufstat;
   1742 
   1743 	if (SSCOM_ISALIVE(sc) == 0)
   1744 		return 0;
   1745 
   1746 	SSCOM_LOCK(sc);
   1747 
   1748 	ufstat = bus_space_read_2(iot, ioh, SSCOM_UFSTAT);
   1749 
   1750 	/*
   1751 	 * If we've delayed a parameter change, do it
   1752 	 * now, and restart * output.
   1753 	 */
   1754 	if (sc->sc_heldchange && (ufstat & UFSTAT_TXCOUNT) == 0) {
   1755 		/* XXX: we should check transmitter empty also */
   1756 		sscom_loadchannelregs(sc);
   1757 		sc->sc_heldchange = 0;
   1758 		sc->sc_tbc = sc->sc_heldtbc;
   1759 		sc->sc_heldtbc = 0;
   1760 	}
   1761 
   1762 	/*
   1763 	 * See if data can be transmitted as well. Schedule tx
   1764 	 * done event if no data left and tty was marked busy.
   1765 	 */
   1766 	if (!ISSET(ufstat,UFSTAT_TXFULL)) {
   1767 		/*
   1768 		 * Output the next chunk of the contiguous
   1769 		 * buffer, if any.
   1770 		 */
   1771 		if (sc->sc_tbc > 0) {
   1772 			__sscom_output_chunk(sc, ufstat);
   1773 		}
   1774 		else {
   1775 			/*
   1776 			 * Disable transmit sscompletion
   1777 			 * interrupts if necessary.
   1778 			 */
   1779 			if (sc->sc_hwflags & SSCOM_HW_TXINT)
   1780 				sscom_disable_txint(sc);
   1781 			if (sc->sc_tx_busy) {
   1782 				sc->sc_tx_busy = 0;
   1783 				sc->sc_tx_done = 1;
   1784 			}
   1785 		}
   1786 	}
   1787 
   1788 	SSCOM_UNLOCK(sc);
   1789 
   1790 	/* Wake up the poller. */
   1791 	softint_schedule(sc->sc_si);
   1792 
   1793 #if NRND > 0 && defined(RND_COM)
   1794 	rnd_add_uint32(&sc->rnd_source, iir | rsr);
   1795 #endif
   1796 
   1797 	return 1;
   1798 }
   1799 
   1800 
   1801 #if defined(KGDB) || defined(SSCOM0CONSOLE) || defined(SSCOM1CONSOLE)
   1802 /*
   1803  * Initialize UART for use as console or KGDB line.
   1804  */
   1805 static int
   1806 sscom_init(bus_space_tag_t iot, const struct sscom_uart_info *config,
   1807     int rate, int frequency, tcflag_t cflag, bus_space_handle_t *iohp)
   1808 {
   1809 	bus_space_handle_t ioh;
   1810 	bus_addr_t iobase = config->iobase;
   1811 
   1812 	if (bus_space_map(iot, iobase, SSCOM_SIZE, 0, &ioh))
   1813 		return ENOMEM; /* ??? */
   1814 
   1815 	bus_space_write_2(iot, ioh, SSCOM_UCON, 0);
   1816 	bus_space_write_1(iot, ioh, SSCOM_UFCON,
   1817 	    UFCON_TXTRIGGER_8 | UFCON_RXTRIGGER_8 |
   1818 	    UFCON_TXFIFO_RESET | UFCON_RXFIFO_RESET |
   1819 	    UFCON_FIFO_ENABLE );
   1820 	/* tx/rx fifo reset are auto-cleared */
   1821 
   1822 	rate = sscomspeed(rate, frequency);
   1823 	bus_space_write_2(iot, ioh, SSCOM_UBRDIV, rate);
   1824 	bus_space_write_2(iot, ioh, SSCOM_ULCON, cflag2lcr(cflag));
   1825 
   1826 	/* enable UART */
   1827 	bus_space_write_2(iot, ioh, SSCOM_UCON,
   1828 	    UCON_TXMODE_INT|UCON_RXMODE_INT);
   1829 	bus_space_write_2(iot, ioh, SSCOM_UMCON, UMCON_RTS);
   1830 
   1831 	*iohp = ioh;
   1832 	return 0;
   1833 }
   1834 
   1835 #endif
   1836 
   1837 #if defined(SSCOM0CONSOLE) || defined(SSCOM1CONSOLE)
   1838 /*
   1839  * Following are all routines needed for SSCOM to act as console
   1840  */
   1841 struct consdev sscomcons = {
   1842 	NULL, NULL, sscomcngetc, sscomcnputc, sscomcnpollc, NULL,
   1843 	NULL, NULL, NODEV, CN_NORMAL
   1844 };
   1845 
   1846 
   1847 int
   1848 sscom_cnattach(bus_space_tag_t iot, const struct sscom_uart_info *config,
   1849     int rate, int frequency, tcflag_t cflag)
   1850 {
   1851 	int res;
   1852 
   1853 	res = sscom_init(iot, config, rate, frequency, cflag, &sscomconsioh);
   1854 	if (res)
   1855 		return res;
   1856 
   1857 	cn_tab = &sscomcons;
   1858 	cn_init_magic(&sscom_cnm_state);
   1859 	cn_set_magic("\047\001"); /* default magic is BREAK */
   1860 
   1861 	sscomconstag = iot;
   1862 	sscomconsunit = config->unit;
   1863 	sscomconsrate = rate;
   1864 	sscomconscflag = cflag;
   1865 
   1866 	return 0;
   1867 }
   1868 
   1869 void
   1870 sscom_cndetach(void)
   1871 {
   1872 	bus_space_unmap(sscomconstag, sscomconsioh, SSCOM_SIZE);
   1873 	sscomconstag = NULL;
   1874 
   1875 	cn_tab = NULL;
   1876 }
   1877 
   1878 /*
   1879  * The read-ahead code is so that you can detect pending in-band
   1880  * cn_magic in polled mode while doing output rather than having to
   1881  * wait until the kernel decides it needs input.
   1882  */
   1883 
   1884 #define MAX_READAHEAD	20
   1885 static int sscom_readahead[MAX_READAHEAD];
   1886 static int sscom_readaheadcount = 0;
   1887 
   1888 int
   1889 sscomcngetc(dev_t dev)
   1890 {
   1891 	int s = splserial();
   1892 	u_char stat, c;
   1893 
   1894 	/* got a character from reading things earlier */
   1895 	if (sscom_readaheadcount > 0) {
   1896 		int i;
   1897 
   1898 		c = sscom_readahead[0];
   1899 		for (i = 1; i < sscom_readaheadcount; i++) {
   1900 			sscom_readahead[i-1] = sscom_readahead[i];
   1901 		}
   1902 		sscom_readaheadcount--;
   1903 		splx(s);
   1904 		return c;
   1905 	}
   1906 
   1907 	/* block until a character becomes available */
   1908 	while (!sscom_rxrdy(sscomconstag, sscomconsioh))
   1909 		;
   1910 
   1911 	c = sscom_getc(sscomconstag, sscomconsioh);
   1912 	stat = sscom_geterr(sscomconstag, sscomconsioh);
   1913 	{
   1914 		int cn_trapped = 0; /* unused */
   1915 #ifdef DDB
   1916 		extern int db_active;
   1917 		if (!db_active)
   1918 #endif
   1919 			cn_check_magic(dev, c, sscom_cnm_state);
   1920 	}
   1921 	splx(s);
   1922 	return c;
   1923 }
   1924 
   1925 /*
   1926  * Console kernel output character routine.
   1927  */
   1928 void
   1929 sscomcnputc(dev_t dev, int c)
   1930 {
   1931 	int s = splserial();
   1932 	int timo;
   1933 
   1934 	int cin, stat;
   1935 	if (sscom_readaheadcount < MAX_READAHEAD &&
   1936 	    sscom_rxrdy(sscomconstag, sscomconsioh)) {
   1937 
   1938 		int cn_trapped = 0;
   1939 		cin = sscom_getc(sscomconstag, sscomconsioh);
   1940 		stat = sscom_geterr(sscomconstag, sscomconsioh);
   1941 		cn_check_magic(dev, cin, sscom_cnm_state);
   1942 		sscom_readahead[sscom_readaheadcount++] = cin;
   1943 	}
   1944 
   1945 	/* wait for any pending transmission to finish */
   1946 	timo = 150000;
   1947 	while (ISSET(bus_space_read_2(sscomconstag, sscomconsioh, SSCOM_UFSTAT),
   1948 		   UFSTAT_TXFULL) && --timo)
   1949 		continue;
   1950 
   1951 	bus_space_write_1(sscomconstag, sscomconsioh, SSCOM_UTXH, c);
   1952 	SSCOM_BARRIER(sscomconstag, sscomconsioh, BR | BW);
   1953 
   1954 #if 0
   1955 	/* wait for this transmission to complete */
   1956 	timo = 1500000;
   1957 	while (!ISSET(bus_space_read_1(sscomconstag, sscomconsioh, SSCOM_UTRSTAT),
   1958 		   UTRSTAT_TXEMPTY) && --timo)
   1959 		continue;
   1960 #endif
   1961 	splx(s);
   1962 }
   1963 
   1964 void
   1965 sscomcnpollc(dev_t dev, int on)
   1966 {
   1967 
   1968 }
   1969 
   1970 #endif /* SSCOM0CONSOLE||SSCOM1CONSOLE */
   1971 
   1972 #ifdef KGDB
   1973 int
   1974 sscom_kgdb_attach(bus_space_tag_t iot, const struct sscom_uart_info *config,
   1975     int rate, int frequency, tcflag_t cflag)
   1976 {
   1977 	int res;
   1978 
   1979 	if (iot == sscomconstag && config->unit == sscomconsunit) {
   1980 		printf( "console==kgdb_port (%d): kgdb disabled\n", sscomconsunit);
   1981 		return EBUSY; /* cannot share with console */
   1982 	}
   1983 
   1984 	res = sscom_init(iot, config, rate, frequency, cflag, &sscom_kgdb_ioh);
   1985 	if (res)
   1986 		return res;
   1987 
   1988 	kgdb_attach(sscom_kgdb_getc, sscom_kgdb_putc, NULL);
   1989 	kgdb_dev = 123; /* unneeded, only to satisfy some tests */
   1990 
   1991 	sscom_kgdb_iot = iot;
   1992 	sscom_kgdb_unit = config->unit;
   1993 
   1994 	return 0;
   1995 }
   1996 
   1997 /* ARGSUSED */
   1998 int
   1999 sscom_kgdb_getc(void *arg)
   2000 {
   2001 	int c, stat;
   2002 
   2003 	/* block until a character becomes available */
   2004 	while (!sscom_rxrdy(sscom_kgdb_iot, sscom_kgdb_ioh))
   2005 		;
   2006 
   2007 	c = sscom_getc(sscom_kgdb_iot, sscom_kgdb_ioh);
   2008 	stat = sscom_geterr(sscom_kgdb_iot, sscom_kgdb_ioh);
   2009 
   2010 	return c;
   2011 }
   2012 
   2013 /* ARGSUSED */
   2014 void
   2015 sscom_kgdb_putc(void *arg, int c)
   2016 {
   2017 	int timo;
   2018 
   2019 	/* wait for any pending transmission to finish */
   2020 	timo = 150000;
   2021 	while (ISSET(bus_space_read_2(sscom_kgdb_iot, sscom_kgdb_ioh,
   2022 	    SSCOM_UFSTAT), UFSTAT_TXFULL) && --timo)
   2023 		continue;
   2024 
   2025 	bus_space_write_1(sscom_kgdb_iot, sscom_kgdb_ioh, SSCOM_UTXH, c);
   2026 	SSCOM_BARRIER(sscom_kgdb_iot, sscom_kgdb_ioh, BR | BW);
   2027 
   2028 #if 0
   2029 	/* wait for this transmission to complete */
   2030 	timo = 1500000;
   2031 	while (!ISSET(bus_space_read_1(sscom_kgdb_iot, sscom_kgdb_ioh,
   2032 	    SSCOM_UTRSTAT), UTRSTAT_TXEMPTY) && --timo)
   2033 		continue;
   2034 #endif
   2035 }
   2036 #endif /* KGDB */
   2037 
   2038 /* helper function to identify the sscom ports used by
   2039  console or KGDB (and not yet autoconf attached) */
   2040 int
   2041 sscom_is_console(bus_space_tag_t iot, int unit,
   2042     bus_space_handle_t *ioh)
   2043 {
   2044 	bus_space_handle_t help;
   2045 
   2046 	if (!sscomconsattached &&
   2047 	    iot == sscomconstag && unit == sscomconsunit)
   2048 		help = sscomconsioh;
   2049 #ifdef KGDB
   2050 	else if (!sscom_kgdb_attached &&
   2051 	    iot == sscom_kgdb_iot && unit == sscom_kgdb_unit)
   2052 		help = sscom_kgdb_ioh;
   2053 #endif
   2054 	else
   2055 		return 0;
   2056 
   2057 	if (ioh)
   2058 		*ioh = help;
   2059 	return 1;
   2060 }
   2061