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sscom.c revision 1.32.4.1
      1 /*	$NetBSD: sscom.c,v 1.32.4.1 2011/05/31 03:03:56 rmind 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 1.32.4.1 2011/05/31 03:03:56 rmind 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 	tp = tty_alloc();
    462 	tp->t_oproc = sscomstart;
    463 	tp->t_param = sscomparam;
    464 	tp->t_hwiflow = sscomhwiflow;
    465 
    466 	sc->sc_tty = tp;
    467 	sc->sc_rbuf = malloc(sscom_rbuf_size << 1, M_DEVBUF, M_NOWAIT);
    468 	sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
    469 	sc->sc_rbavail = sscom_rbuf_size;
    470 	if (sc->sc_rbuf == NULL) {
    471 		printf("%s: unable to allocate ring buffer\n",
    472 		    sc->sc_dev.dv_xname);
    473 		return;
    474 	}
    475 	sc->sc_ebuf = sc->sc_rbuf + (sscom_rbuf_size << 1);
    476 
    477 	tty_attach(tp);
    478 
    479 	if (ISSET(sc->sc_hwflags, SSCOM_HW_CONSOLE)) {
    480 		int maj;
    481 
    482 		/* locate the major number */
    483 		maj = cdevsw_lookup_major(&sscom_cdevsw);
    484 
    485 		cn_tab->cn_dev = makedev(maj, device_unit(&sc->sc_dev));
    486 
    487 		printf("%s: console (major=%d)\n", sc->sc_dev.dv_xname, maj);
    488 	}
    489 
    490 
    491 	sc->sc_si = softint_establish(SOFTINT_SERIAL, sscomsoft, sc);
    492 
    493 #if NRND > 0 && defined(RND_COM)
    494 	rnd_attach_source(&sc->rnd_source, sc->sc_dev.dv_xname,
    495 			  RND_TYPE_TTY, 0);
    496 #endif
    497 
    498 	/* if there are no enable/disable functions, assume the device
    499 	   is always enabled */
    500 
    501 	if (ISSET(sc->sc_hwflags, SSCOM_HW_CONSOLE))
    502 		sscom_enable_debugport(sc);
    503 	else
    504 		sscom_disable_txrxint(sc);
    505 
    506 	SET(sc->sc_hwflags, SSCOM_HW_DEV_OK);
    507 }
    508 
    509 int
    510 sscom_detach(device_t self, int flags)
    511 {
    512 	struct sscom_softc *sc = device_private(self);
    513 
    514 	if (sc->sc_hwflags & (SSCOM_HW_CONSOLE|SSCOM_HW_KGDB))
    515 		return EBUSY;
    516 
    517 	return 0;
    518 }
    519 
    520 int
    521 sscom_activate(device_t self, enum devact act)
    522 {
    523 #ifdef notyet
    524 	struct sscom_softc *sc = device_private(self);
    525 #endif
    526 
    527 	switch (act) {
    528 	case DVACT_DEACTIVATE:
    529 #ifdef notyet
    530 		sc->enabled = 0;
    531 #endif
    532 		return 0;
    533 	default:
    534 		return EOPNOTSUPP;
    535 	}
    536 }
    537 
    538 void
    539 sscom_shutdown(struct sscom_softc *sc)
    540 {
    541 #ifdef notyet
    542 	struct tty *tp = sc->sc_tty;
    543 	int s;
    544 
    545 	s = splserial();
    546 	SSCOM_LOCK(sc);
    547 
    548 	/* If we were asserting flow control, then deassert it. */
    549 	SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
    550 	sscom_hwiflow(sc);
    551 
    552 	/* Clear any break condition set with TIOCSBRK. */
    553 	sscom_break(sc, 0);
    554 
    555 	/*
    556 	 * Hang up if necessary.  Wait a bit, so the other side has time to
    557 	 * notice even if we immediately open the port again.
    558 	 * Avoid tsleeping above splhigh().
    559 	 */
    560 	if (ISSET(tp->t_cflag, HUPCL)) {
    561 		sscom_modem(sc, 0);
    562 		SSCOM_UNLOCK(sc);
    563 		splx(s);
    564 		/* XXX tsleep will only timeout */
    565 		(void) tsleep(sc, TTIPRI, ttclos, hz);
    566 		s = splserial();
    567 		SSCOM_LOCK(sc);
    568 	}
    569 
    570 	if (ISSET(sc->sc_hwflags, SSCOM_HW_CONSOLE))
    571 		/* interrupt on break */
    572 		sc->sc_ucon = UCON_DEBUGPORT;
    573 	else
    574 		sc->sc_ucon = 0;
    575 	bus_space_write_2(sc->sc_iot, sc->sc_ioh, SSCOM_UCON, sc->sc_ucon);
    576 
    577 #ifdef DIAGNOSTIC
    578 	if (!sc->enabled)
    579 		panic("sscom_shutdown: not enabled?");
    580 #endif
    581 	sc->enabled = 0;
    582 	SSCOM_UNLOCK(sc);
    583 	splx(s);
    584 #endif
    585 }
    586 
    587 int
    588 sscomopen(dev_t dev, int flag, int mode, struct lwp *l)
    589 {
    590 	struct sscom_softc *sc;
    591 	struct tty *tp;
    592 	int s, s2;
    593 	int error;
    594 
    595 	sc = device_lookup_private(&sscom_cd, SSCOMUNIT(dev));
    596 	if (sc == NULL || !ISSET(sc->sc_hwflags, SSCOM_HW_DEV_OK) ||
    597 		sc->sc_rbuf == NULL)
    598 		return ENXIO;
    599 
    600 	if (!device_is_active(&sc->sc_dev))
    601 		return ENXIO;
    602 
    603 #ifdef KGDB
    604 	/*
    605 	 * If this is the kgdb port, no other use is permitted.
    606 	 */
    607 	if (ISSET(sc->sc_hwflags, SSCOM_HW_KGDB))
    608 		return EBUSY;
    609 #endif
    610 
    611 	tp = sc->sc_tty;
    612 
    613 	if (kauth_authorize_device_tty(l->l_cred, KAUTH_DEVICE_TTY_OPEN, tp))
    614 		return (EBUSY);
    615 
    616 	s = spltty();
    617 
    618 	/*
    619 	 * Do the following iff this is a first open.
    620 	 */
    621 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
    622 		struct termios t;
    623 
    624 		tp->t_dev = dev;
    625 
    626 		s2 = splserial();
    627 		SSCOM_LOCK(sc);
    628 
    629 		/* Turn on interrupts. */
    630 		sscom_enable_txrxint(sc);
    631 
    632 		/* Fetch the current modem control status, needed later. */
    633 		sc->sc_msts = sc->read_modem_status(sc);
    634 
    635 #if 0
    636 		/* Clear PPS capture state on first open. */
    637 		sc->sc_ppsmask = 0;
    638 		sc->ppsparam.mode = 0;
    639 #endif
    640 
    641 		SSCOM_UNLOCK(sc);
    642 		splx(s2);
    643 
    644 		/*
    645 		 * Initialize the termios status to the defaults.  Add in the
    646 		 * sticky bits from TIOCSFLAGS.
    647 		 */
    648 		t.c_ispeed = 0;
    649 		if (ISSET(sc->sc_hwflags, SSCOM_HW_CONSOLE)) {
    650 			t.c_ospeed = sscomconsrate;
    651 			t.c_cflag = sscomconscflag;
    652 		} else {
    653 			t.c_ospeed = TTYDEF_SPEED;
    654 			t.c_cflag = TTYDEF_CFLAG;
    655 		}
    656 		if (ISSET(sc->sc_swflags, TIOCFLAG_CLOCAL))
    657 			SET(t.c_cflag, CLOCAL);
    658 		if (ISSET(sc->sc_swflags, TIOCFLAG_CRTSCTS))
    659 			SET(t.c_cflag, CRTSCTS);
    660 		if (ISSET(sc->sc_swflags, TIOCFLAG_MDMBUF))
    661 			SET(t.c_cflag, MDMBUF);
    662 		/* Make sure sscomparam() will do something. */
    663 		tp->t_ospeed = 0;
    664 		(void) sscomparam(tp, &t);
    665 		tp->t_iflag = TTYDEF_IFLAG;
    666 		tp->t_oflag = TTYDEF_OFLAG;
    667 		tp->t_lflag = TTYDEF_LFLAG;
    668 		ttychars(tp);
    669 		ttsetwater(tp);
    670 
    671 		s2 = splserial();
    672 		SSCOM_LOCK(sc);
    673 
    674 		/*
    675 		 * Turn on DTR.  We must always do this, even if carrier is not
    676 		 * present, because otherwise we'd have to use TIOCSDTR
    677 		 * immediately after setting CLOCAL, which applications do not
    678 		 * expect.  We always assert DTR while the device is open
    679 		 * unless explicitly requested to deassert it.
    680 		 */
    681 		sscom_modem(sc, 1);
    682 
    683 		/* Clear the input ring, and unblock. */
    684 		sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
    685 		sc->sc_rbavail = sscom_rbuf_size;
    686 		sscom_iflush(sc);
    687 		CLR(sc->sc_rx_flags, RX_ANY_BLOCK);
    688 		sscom_hwiflow(sc);
    689 
    690 		if (sscom_debug)
    691 			sscomstatus(sc, "sscomopen  ");
    692 
    693 		SSCOM_UNLOCK(sc);
    694 		splx(s2);
    695 	}
    696 
    697 	splx(s);
    698 
    699 	error = ttyopen(tp, SSCOMDIALOUT(dev), ISSET(flag, O_NONBLOCK));
    700 	if (error)
    701 		goto bad;
    702 
    703 	error = (*tp->t_linesw->l_open)(dev, tp);
    704 	if (error)
    705 		goto bad;
    706 
    707 	return 0;
    708 
    709 bad:
    710 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
    711 		/*
    712 		 * We failed to open the device, and nobody else had it opened.
    713 		 * Clean up the state as appropriate.
    714 		 */
    715 		sscom_shutdown(sc);
    716 	}
    717 
    718 	return error;
    719 }
    720 
    721 int
    722 sscomclose(dev_t dev, int flag, int mode, struct lwp *l)
    723 {
    724 	struct sscom_softc *sc = device_lookup_private(&sscom_cd, SSCOMUNIT(dev));
    725 	struct tty *tp = sc->sc_tty;
    726 
    727 	/* XXX This is for cons.c. */
    728 	if (!ISSET(tp->t_state, TS_ISOPEN))
    729 		return 0;
    730 
    731 	(*tp->t_linesw->l_close)(tp, flag);
    732 	ttyclose(tp);
    733 
    734 	if (SSCOM_ISALIVE(sc) == 0)
    735 		return 0;
    736 
    737 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
    738 		/*
    739 		 * Although we got a last close, the device may still be in
    740 		 * use; e.g. if this was the dialout node, and there are still
    741 		 * processes waiting for carrier on the non-dialout node.
    742 		 */
    743 		sscom_shutdown(sc);
    744 	}
    745 
    746 	return 0;
    747 }
    748 
    749 int
    750 sscomread(dev_t dev, struct uio *uio, int flag)
    751 {
    752 	struct sscom_softc *sc = device_lookup_private(&sscom_cd, SSCOMUNIT(dev));
    753 	struct tty *tp = sc->sc_tty;
    754 
    755 	if (SSCOM_ISALIVE(sc) == 0)
    756 		return EIO;
    757 
    758 	return (*tp->t_linesw->l_read)(tp, uio, flag);
    759 }
    760 
    761 int
    762 sscomwrite(dev_t dev, struct uio *uio, int flag)
    763 {
    764 	struct sscom_softc *sc = device_lookup_private(&sscom_cd, SSCOMUNIT(dev));
    765 	struct tty *tp = sc->sc_tty;
    766 
    767 	if (SSCOM_ISALIVE(sc) == 0)
    768 		return EIO;
    769 
    770 	return (*tp->t_linesw->l_write)(tp, uio, flag);
    771 }
    772 
    773 int
    774 sscompoll(dev_t dev, int events, struct lwp *l)
    775 {
    776 	struct sscom_softc *sc = device_lookup_private(&sscom_cd, SSCOMUNIT(dev));
    777 	struct tty *tp = sc->sc_tty;
    778 
    779 	if (SSCOM_ISALIVE(sc) == 0)
    780 		return EIO;
    781 
    782 	return (*tp->t_linesw->l_poll)(tp, events, l);
    783 }
    784 
    785 struct tty *
    786 sscomtty(dev_t dev)
    787 {
    788 	struct sscom_softc *sc = device_lookup_private(&sscom_cd, SSCOMUNIT(dev));
    789 	struct tty *tp = sc->sc_tty;
    790 
    791 	return tp;
    792 }
    793 
    794 int
    795 sscomioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
    796 {
    797 	struct sscom_softc *sc = device_lookup_private(&sscom_cd, SSCOMUNIT(dev));
    798 	struct tty *tp = sc->sc_tty;
    799 	int error;
    800 	int s;
    801 
    802 	if (SSCOM_ISALIVE(sc) == 0)
    803 		return EIO;
    804 
    805 	error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, l);
    806 	if (error != EPASSTHROUGH)
    807 		return error;
    808 
    809 	error = ttioctl(tp, cmd, data, flag, l);
    810 	if (error != EPASSTHROUGH)
    811 		return error;
    812 
    813 	error = 0;
    814 
    815 	s = splserial();
    816 	SSCOM_LOCK(sc);
    817 
    818 	switch (cmd) {
    819 	case TIOCSBRK:
    820 		sscom_break(sc, 1);
    821 		break;
    822 
    823 	case TIOCCBRK:
    824 		sscom_break(sc, 0);
    825 		break;
    826 
    827 	case TIOCSDTR:
    828 		sscom_modem(sc, 1);
    829 		break;
    830 
    831 	case TIOCCDTR:
    832 		sscom_modem(sc, 0);
    833 		break;
    834 
    835 	case TIOCGFLAGS:
    836 		*(int *)data = sc->sc_swflags;
    837 		break;
    838 
    839 	case TIOCSFLAGS:
    840 		error = kauth_authorize_device_tty(l->l_cred,
    841 		    KAUTH_DEVICE_TTY_PRIVSET, tp);
    842 		if (error)
    843 			break;
    844 		sc->sc_swflags = *(int *)data;
    845 		break;
    846 
    847 	case TIOCMSET:
    848 	case TIOCMBIS:
    849 	case TIOCMBIC:
    850 		tiocm_to_sscom(sc, cmd, *(int *)data);
    851 		break;
    852 
    853 	case TIOCMGET:
    854 		*(int *)data = sscom_to_tiocm(sc);
    855 		break;
    856 
    857 	default:
    858 		error = EPASSTHROUGH;
    859 		break;
    860 	}
    861 
    862 	SSCOM_UNLOCK(sc);
    863 	splx(s);
    864 
    865 	if (sscom_debug)
    866 		sscomstatus(sc, "sscomioctl ");
    867 
    868 	return error;
    869 }
    870 
    871 integrate void
    872 sscom_schedrx(struct sscom_softc *sc)
    873 {
    874 
    875 	sc->sc_rx_ready = 1;
    876 
    877 	/* Wake up the poller. */
    878 	softint_schedule(sc->sc_si);
    879 }
    880 
    881 static void
    882 sscom_break(struct sscom_softc *sc, int onoff)
    883 {
    884 
    885 	if (onoff)
    886 		SET(sc->sc_ucon, UCON_SBREAK);
    887 	else
    888 		CLR(sc->sc_ucon, UCON_SBREAK);
    889 
    890 	if (!sc->sc_heldchange) {
    891 		if (sc->sc_tx_busy) {
    892 			sc->sc_heldtbc = sc->sc_tbc;
    893 			sc->sc_tbc = 0;
    894 			sc->sc_heldchange = 1;
    895 		} else
    896 			sscom_loadchannelregs(sc);
    897 	}
    898 }
    899 
    900 static void
    901 sscom_modem(struct sscom_softc *sc, int onoff)
    902 {
    903 	if (onoff)
    904 		SET(sc->sc_umcon, UMCON_DTR);
    905 	else
    906 		CLR(sc->sc_umcon, UMCON_DTR);
    907 
    908 	if (!sc->sc_heldchange) {
    909 		if (sc->sc_tx_busy) {
    910 			sc->sc_heldtbc = sc->sc_tbc;
    911 			sc->sc_tbc = 0;
    912 			sc->sc_heldchange = 1;
    913 		} else
    914 			sscom_loadchannelregs(sc);
    915 	}
    916 }
    917 
    918 static void
    919 tiocm_to_sscom(struct sscom_softc *sc, u_long how, int ttybits)
    920 {
    921 	u_char sscombits;
    922 
    923 	sscombits = 0;
    924 	if (ISSET(ttybits, TIOCM_DTR))
    925 		sscombits = UMCON_DTR;
    926 	if (ISSET(ttybits, TIOCM_RTS))
    927 		SET(sscombits, UMCON_RTS);
    928 
    929 	switch (how) {
    930 	case TIOCMBIC:
    931 		CLR(sc->sc_umcon, sscombits);
    932 		break;
    933 
    934 	case TIOCMBIS:
    935 		SET(sc->sc_umcon, sscombits);
    936 		break;
    937 
    938 	case TIOCMSET:
    939 		CLR(sc->sc_umcon, UMCON_DTR);
    940 		SET(sc->sc_umcon, sscombits);
    941 		break;
    942 	}
    943 
    944 	if (!sc->sc_heldchange) {
    945 		if (sc->sc_tx_busy) {
    946 			sc->sc_heldtbc = sc->sc_tbc;
    947 			sc->sc_tbc = 0;
    948 			sc->sc_heldchange = 1;
    949 		} else
    950 			sscom_loadchannelregs(sc);
    951 	}
    952 }
    953 
    954 static int
    955 sscom_to_tiocm(struct sscom_softc *sc)
    956 {
    957 	u_char sscombits;
    958 	int ttybits = 0;
    959 
    960 	sscombits = sc->sc_umcon;
    961 #if 0
    962 	if (ISSET(sscombits, MCR_DTR))
    963 		SET(ttybits, TIOCM_DTR);
    964 #endif
    965 	if (ISSET(sscombits, UMCON_RTS))
    966 		SET(ttybits, TIOCM_RTS);
    967 
    968 	sscombits = sc->sc_msts;
    969 	if (ISSET(sscombits, MSTS_DCD))
    970 		SET(ttybits, TIOCM_CD);
    971 	if (ISSET(sscombits, MSTS_DSR))
    972 		SET(ttybits, TIOCM_DSR);
    973 	if (ISSET(sscombits, MSTS_CTS))
    974 		SET(ttybits, TIOCM_CTS);
    975 
    976 	if (sc->sc_ucon != 0)
    977 		SET(ttybits, TIOCM_LE);
    978 
    979 	return ttybits;
    980 }
    981 
    982 static int
    983 cflag2lcr(tcflag_t cflag)
    984 {
    985 	u_char lcr = ULCON_PARITY_NONE;
    986 
    987 	switch (cflag & (PARENB|PARODD)) {
    988 	case PARENB|PARODD: lcr = ULCON_PARITY_ODD; break;
    989 	case PARENB: lcr = ULCON_PARITY_EVEN;
    990 	}
    991 
    992 	switch (ISSET(cflag, CSIZE)) {
    993 	case CS5:
    994 		SET(lcr, ULCON_LENGTH_5);
    995 		break;
    996 	case CS6:
    997 		SET(lcr, ULCON_LENGTH_6);
    998 		break;
    999 	case CS7:
   1000 		SET(lcr, ULCON_LENGTH_7);
   1001 		break;
   1002 	case CS8:
   1003 		SET(lcr, ULCON_LENGTH_8);
   1004 		break;
   1005 	}
   1006 	if (ISSET(cflag, CSTOPB))
   1007 		SET(lcr, ULCON_STOP);
   1008 
   1009 	return lcr;
   1010 }
   1011 
   1012 int
   1013 sscomparam(struct tty *tp, struct termios *t)
   1014 {
   1015 	struct sscom_softc *sc = device_lookup_private(&sscom_cd, SSCOMUNIT(tp->t_dev));
   1016 	int ospeed;
   1017 	u_char lcr;
   1018 	int s;
   1019 
   1020 	if (SSCOM_ISALIVE(sc) == 0)
   1021 		return EIO;
   1022 
   1023 	ospeed = sscomspeed(t->c_ospeed, sc->sc_frequency);
   1024 
   1025 	/* Check requested parameters. */
   1026 	if (ospeed < 0)
   1027 		return EINVAL;
   1028 	if (t->c_ispeed && t->c_ispeed != t->c_ospeed)
   1029 		return EINVAL;
   1030 
   1031 	/*
   1032 	 * For the console, always force CLOCAL and !HUPCL, so that the port
   1033 	 * is always active.
   1034 	 */
   1035 	if (ISSET(sc->sc_swflags, TIOCFLAG_SOFTCAR) ||
   1036 	    ISSET(sc->sc_hwflags, SSCOM_HW_CONSOLE)) {
   1037 		SET(t->c_cflag, CLOCAL);
   1038 		CLR(t->c_cflag, HUPCL);
   1039 	}
   1040 
   1041 	/*
   1042 	 * If there were no changes, don't do anything.  This avoids dropping
   1043 	 * input and improves performance when all we did was frob things like
   1044 	 * VMIN and VTIME.
   1045 	 */
   1046 	if (tp->t_ospeed == t->c_ospeed &&
   1047 	    tp->t_cflag == t->c_cflag)
   1048 		return 0;
   1049 
   1050 	lcr = cflag2lcr(t->c_cflag);
   1051 
   1052 	s = splserial();
   1053 	SSCOM_LOCK(sc);
   1054 
   1055 	sc->sc_ulcon = lcr;
   1056 
   1057 	/*
   1058 	 * If we're not in a mode that assumes a connection is present, then
   1059 	 * ignore carrier changes.
   1060 	 */
   1061 	if (ISSET(t->c_cflag, CLOCAL | MDMBUF))
   1062 		sc->sc_msr_dcd = 0;
   1063 	else
   1064 		sc->sc_msr_dcd = MSTS_DCD;
   1065 
   1066 	/*
   1067 	 * Set the flow control pins depending on the current flow control
   1068 	 * mode.
   1069 	 */
   1070 	if (ISSET(t->c_cflag, CRTSCTS)) {
   1071 		sc->sc_mcr_dtr = UMCON_DTR;
   1072 		sc->sc_mcr_rts = UMCON_RTS;
   1073 		sc->sc_msr_cts = MSTS_CTS;
   1074 	}
   1075 	else if (ISSET(t->c_cflag, MDMBUF)) {
   1076 		/*
   1077 		 * For DTR/DCD flow control, make sure we don't toggle DTR for
   1078 		 * carrier detection.
   1079 		 */
   1080 		sc->sc_mcr_dtr = 0;
   1081 		sc->sc_mcr_rts = UMCON_DTR;
   1082 		sc->sc_msr_cts = MSTS_DCD;
   1083 	}
   1084 	else {
   1085 		/*
   1086 		 * If no flow control, then always set RTS.  This will make
   1087 		 * the other side happy if it mistakenly thinks we're doing
   1088 		 * RTS/CTS flow control.
   1089 		 */
   1090 		sc->sc_mcr_dtr = UMCON_DTR | UMCON_RTS;
   1091 		sc->sc_mcr_rts = 0;
   1092 		sc->sc_msr_cts = 0;
   1093 		if (ISSET(sc->sc_umcon, UMCON_DTR))
   1094 			SET(sc->sc_umcon, UMCON_RTS);
   1095 		else
   1096 			CLR(sc->sc_umcon, UMCON_RTS);
   1097 	}
   1098 	sc->sc_msr_mask = sc->sc_msr_cts | sc->sc_msr_dcd;
   1099 
   1100 	if (ospeed == 0)
   1101 		CLR(sc->sc_umcon, sc->sc_mcr_dtr);
   1102 	else
   1103 		SET(sc->sc_umcon, sc->sc_mcr_dtr);
   1104 
   1105 	sc->sc_ubrdiv = ospeed;
   1106 
   1107 	/* And copy to tty. */
   1108 	tp->t_ispeed = 0;
   1109 	tp->t_ospeed = t->c_ospeed;
   1110 	tp->t_cflag = t->c_cflag;
   1111 
   1112 	if (!sc->sc_heldchange) {
   1113 		if (sc->sc_tx_busy) {
   1114 			sc->sc_heldtbc = sc->sc_tbc;
   1115 			sc->sc_tbc = 0;
   1116 			sc->sc_heldchange = 1;
   1117 		} else
   1118 			sscom_loadchannelregs(sc);
   1119 	}
   1120 
   1121 	if (!ISSET(t->c_cflag, CHWFLOW)) {
   1122 		/* Disable the high water mark. */
   1123 		sc->sc_r_hiwat = 0;
   1124 		sc->sc_r_lowat = 0;
   1125 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
   1126 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
   1127 			sscom_schedrx(sc);
   1128 		}
   1129 		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED)) {
   1130 			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED);
   1131 			sscom_hwiflow(sc);
   1132 		}
   1133 	} else {
   1134 		sc->sc_r_hiwat = sscom_rbuf_hiwat;
   1135 		sc->sc_r_lowat = sscom_rbuf_lowat;
   1136 	}
   1137 
   1138 	SSCOM_UNLOCK(sc);
   1139 	splx(s);
   1140 
   1141 	/*
   1142 	 * Update the tty layer's idea of the carrier bit, in case we changed
   1143 	 * CLOCAL or MDMBUF.  We don't hang up here; we only do that by
   1144 	 * explicit request.
   1145 	 */
   1146 	(void) (*tp->t_linesw->l_modem)(tp, ISSET(sc->sc_msts, MSTS_DCD));
   1147 
   1148 	if (sscom_debug)
   1149 		sscomstatus(sc, "sscomparam ");
   1150 
   1151 	if (!ISSET(t->c_cflag, CHWFLOW)) {
   1152 		if (sc->sc_tx_stopped) {
   1153 			sc->sc_tx_stopped = 0;
   1154 			sscomstart(tp);
   1155 		}
   1156 	}
   1157 
   1158 	return 0;
   1159 }
   1160 
   1161 static void
   1162 sscom_iflush(struct sscom_softc *sc)
   1163 {
   1164 	bus_space_tag_t iot = sc->sc_iot;
   1165 	bus_space_handle_t ioh = sc->sc_ioh;
   1166 	int timo;
   1167 
   1168 
   1169 	timo = 50000;
   1170 	/* flush any pending I/O */
   1171 	while ( sscom_rxrdy(iot, ioh) && --timo)
   1172 		(void)sscom_getc(iot,ioh);
   1173 #ifdef DIAGNOSTIC
   1174 	if (!timo)
   1175 		printf("%s: sscom_iflush timeout\n", sc->sc_dev.dv_xname);
   1176 #endif
   1177 }
   1178 
   1179 static void
   1180 sscom_loadchannelregs(struct sscom_softc *sc)
   1181 {
   1182 	bus_space_tag_t iot = sc->sc_iot;
   1183 	bus_space_handle_t ioh = sc->sc_ioh;
   1184 
   1185 	/* XXXXX necessary? */
   1186 	sscom_iflush(sc);
   1187 
   1188 	bus_space_write_2(iot, ioh, SSCOM_UCON, 0);
   1189 
   1190 #if 0
   1191 	if (ISSET(sc->sc_hwflags, COM_HW_FLOW)) {
   1192 		bus_space_write_1(iot, ioh, com_lcr, LCR_EERS);
   1193 		bus_space_write_1(iot, ioh, com_efr, sc->sc_efr);
   1194 	}
   1195 #endif
   1196 
   1197 	bus_space_write_2(iot, ioh, SSCOM_UBRDIV, sc->sc_ubrdiv);
   1198 	bus_space_write_1(iot, ioh, SSCOM_ULCON, sc->sc_ulcon);
   1199 	sc->set_modem_control(sc);
   1200 	bus_space_write_2(iot, ioh, SSCOM_UCON, sc->sc_ucon);
   1201 }
   1202 
   1203 static int
   1204 sscomhwiflow(struct tty *tp, int block)
   1205 {
   1206 	struct sscom_softc *sc = device_lookup_private(&sscom_cd, SSCOMUNIT(tp->t_dev));
   1207 	int s;
   1208 
   1209 	if (SSCOM_ISALIVE(sc) == 0)
   1210 		return 0;
   1211 
   1212 	if (sc->sc_mcr_rts == 0)
   1213 		return 0;
   1214 
   1215 	s = splserial();
   1216 	SSCOM_LOCK(sc);
   1217 
   1218 	if (block) {
   1219 		if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
   1220 			SET(sc->sc_rx_flags, RX_TTY_BLOCKED);
   1221 			sscom_hwiflow(sc);
   1222 		}
   1223 	} else {
   1224 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
   1225 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
   1226 			sscom_schedrx(sc);
   1227 		}
   1228 		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
   1229 			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED);
   1230 			sscom_hwiflow(sc);
   1231 		}
   1232 	}
   1233 
   1234 	SSCOM_UNLOCK(sc);
   1235 	splx(s);
   1236 	return 1;
   1237 }
   1238 
   1239 /*
   1240  * (un)block input via hw flowcontrol
   1241  */
   1242 static void
   1243 sscom_hwiflow(struct sscom_softc *sc)
   1244 {
   1245 	if (sc->sc_mcr_rts == 0)
   1246 		return;
   1247 
   1248 	if (ISSET(sc->sc_rx_flags, RX_ANY_BLOCK)) {
   1249 		CLR(sc->sc_umcon, sc->sc_mcr_rts);
   1250 		CLR(sc->sc_mcr_active, sc->sc_mcr_rts);
   1251 	} else {
   1252 		SET(sc->sc_umcon, sc->sc_mcr_rts);
   1253 		SET(sc->sc_mcr_active, sc->sc_mcr_rts);
   1254 	}
   1255 	sc->set_modem_control(sc);
   1256 }
   1257 
   1258 
   1259 void
   1260 sscomstart(struct tty *tp)
   1261 {
   1262 	struct sscom_softc *sc = device_lookup_private(&sscom_cd, SSCOMUNIT(tp->t_dev));
   1263 	int s;
   1264 
   1265 	if (SSCOM_ISALIVE(sc) == 0)
   1266 		return;
   1267 
   1268 	s = spltty();
   1269 	if (ISSET(tp->t_state, TS_BUSY | TS_TIMEOUT | TS_TTSTOP))
   1270 		goto out;
   1271 	if (sc->sc_tx_stopped)
   1272 		goto out;
   1273 	if (!ttypull(tp))
   1274 		goto out;
   1275 
   1276 	/* Grab the first contiguous region of buffer space. */
   1277 	{
   1278 		u_char *tba;
   1279 		int tbc;
   1280 
   1281 		tba = tp->t_outq.c_cf;
   1282 		tbc = ndqb(&tp->t_outq, 0);
   1283 
   1284 		(void)splserial();
   1285 		SSCOM_LOCK(sc);
   1286 
   1287 		sc->sc_tba = tba;
   1288 		sc->sc_tbc = tbc;
   1289 	}
   1290 
   1291 	SET(tp->t_state, TS_BUSY);
   1292 	sc->sc_tx_busy = 1;
   1293 
   1294 	/* Output the first chunk of the contiguous buffer. */
   1295 	sscom_output_chunk(sc);
   1296 
   1297 	/* Enable transmit completion interrupts if necessary. */
   1298 	if ((sc->sc_hwflags & SSCOM_HW_TXINT) == 0)
   1299 		sscom_enable_txint(sc);
   1300 
   1301 	SSCOM_UNLOCK(sc);
   1302 out:
   1303 	splx(s);
   1304 	return;
   1305 }
   1306 
   1307 /*
   1308  * Stop output on a line.
   1309  */
   1310 void
   1311 sscomstop(struct tty *tp, int flag)
   1312 {
   1313 	struct sscom_softc *sc = device_lookup_private(&sscom_cd, SSCOMUNIT(tp->t_dev));
   1314 	int s;
   1315 
   1316 	s = splserial();
   1317 	SSCOM_LOCK(sc);
   1318 	if (ISSET(tp->t_state, TS_BUSY)) {
   1319 		/* Stop transmitting at the next chunk. */
   1320 		sc->sc_tbc = 0;
   1321 		sc->sc_heldtbc = 0;
   1322 		if (!ISSET(tp->t_state, TS_TTSTOP))
   1323 			SET(tp->t_state, TS_FLUSH);
   1324 	}
   1325 	SSCOM_UNLOCK(sc);
   1326 	splx(s);
   1327 }
   1328 
   1329 void
   1330 sscomdiag(void *arg)
   1331 {
   1332 	struct sscom_softc *sc = arg;
   1333 	int overflows, floods;
   1334 	int s;
   1335 
   1336 	s = splserial();
   1337 	SSCOM_LOCK(sc);
   1338 	overflows = sc->sc_overflows;
   1339 	sc->sc_overflows = 0;
   1340 	floods = sc->sc_floods;
   1341 	sc->sc_floods = 0;
   1342 	sc->sc_errors = 0;
   1343 	SSCOM_UNLOCK(sc);
   1344 	splx(s);
   1345 
   1346 	log(LOG_WARNING, "%s: %d silo overflow%s, %d ibuf flood%s\n",
   1347 	    sc->sc_dev.dv_xname,
   1348 	    overflows, overflows == 1 ? "" : "s",
   1349 	    floods, floods == 1 ? "" : "s");
   1350 }
   1351 
   1352 integrate void
   1353 sscom_rxsoft(struct sscom_softc *sc, struct tty *tp)
   1354 {
   1355 	int (*rint) (int, struct tty *) = tp->t_linesw->l_rint;
   1356 	u_char *get, *end;
   1357 	u_int cc, scc;
   1358 	u_char rsr;
   1359 	int code;
   1360 	int s;
   1361 
   1362 	end = sc->sc_ebuf;
   1363 	get = sc->sc_rbget;
   1364 	scc = cc = sscom_rbuf_size - sc->sc_rbavail;
   1365 
   1366 	if (cc == sscom_rbuf_size) {
   1367 		sc->sc_floods++;
   1368 		if (sc->sc_errors++ == 0)
   1369 			callout_reset(&sc->sc_diag_callout, 60 * hz,
   1370 			    sscomdiag, sc);
   1371 	}
   1372 
   1373 	while (cc) {
   1374 		code = get[0];
   1375 		rsr = get[1];
   1376 		if (rsr) {
   1377 			if (ISSET(rsr, UERSTAT_OVERRUN)) {
   1378 				sc->sc_overflows++;
   1379 				if (sc->sc_errors++ == 0)
   1380 					callout_reset(&sc->sc_diag_callout,
   1381 					    60 * hz, sscomdiag, sc);
   1382 			}
   1383 			if (ISSET(rsr, UERSTAT_BREAK | UERSTAT_FRAME))
   1384 				SET(code, TTY_FE);
   1385 			if (ISSET(rsr, UERSTAT_PARITY))
   1386 				SET(code, TTY_PE);
   1387 		}
   1388 		if ((*rint)(code, tp) == -1) {
   1389 			/*
   1390 			 * The line discipline's buffer is out of space.
   1391 			 */
   1392 			if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
   1393 				/*
   1394 				 * We're either not using flow control, or the
   1395 				 * line discipline didn't tell us to block for
   1396 				 * some reason.  Either way, we have no way to
   1397 				 * know when there's more space available, so
   1398 				 * just drop the rest of the data.
   1399 				 */
   1400 				get += cc << 1;
   1401 				if (get >= end)
   1402 					get -= sscom_rbuf_size << 1;
   1403 				cc = 0;
   1404 			} else {
   1405 				/*
   1406 				 * Don't schedule any more receive processing
   1407 				 * until the line discipline tells us there's
   1408 				 * space available (through sscomhwiflow()).
   1409 				 * Leave the rest of the data in the input
   1410 				 * buffer.
   1411 				 */
   1412 				SET(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
   1413 			}
   1414 			break;
   1415 		}
   1416 		get += 2;
   1417 		if (get >= end)
   1418 			get = sc->sc_rbuf;
   1419 		cc--;
   1420 	}
   1421 
   1422 	if (cc != scc) {
   1423 		sc->sc_rbget = get;
   1424 		s = splserial();
   1425 		SSCOM_LOCK(sc);
   1426 
   1427 		cc = sc->sc_rbavail += scc - cc;
   1428 		/* Buffers should be ok again, release possible block. */
   1429 		if (cc >= sc->sc_r_lowat) {
   1430 			if (ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
   1431 				CLR(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
   1432 				sscom_enable_rxint(sc);
   1433 				sc->sc_ucon |= UCON_ERRINT;
   1434 				bus_space_write_2(sc->sc_iot, sc->sc_ioh, SSCOM_UCON,
   1435 						  sc->sc_ucon);
   1436 
   1437 			}
   1438 			if (ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED)) {
   1439 				CLR(sc->sc_rx_flags, RX_IBUF_BLOCKED);
   1440 				sscom_hwiflow(sc);
   1441 			}
   1442 		}
   1443 		SSCOM_UNLOCK(sc);
   1444 		splx(s);
   1445 	}
   1446 }
   1447 
   1448 integrate void
   1449 sscom_txsoft(struct sscom_softc *sc, struct tty *tp)
   1450 {
   1451 
   1452 	CLR(tp->t_state, TS_BUSY);
   1453 	if (ISSET(tp->t_state, TS_FLUSH))
   1454 		CLR(tp->t_state, TS_FLUSH);
   1455 	else
   1456 		ndflush(&tp->t_outq, (int)(sc->sc_tba - tp->t_outq.c_cf));
   1457 	(*tp->t_linesw->l_start)(tp);
   1458 }
   1459 
   1460 integrate void
   1461 sscom_stsoft(struct sscom_softc *sc, struct tty *tp)
   1462 {
   1463 	u_char msr, delta;
   1464 	int s;
   1465 
   1466 	s = splserial();
   1467 	SSCOM_LOCK(sc);
   1468 	msr = sc->sc_msts;
   1469 	delta = sc->sc_msr_delta;
   1470 	sc->sc_msr_delta = 0;
   1471 	SSCOM_UNLOCK(sc);
   1472 	splx(s);
   1473 
   1474 	if (ISSET(delta, sc->sc_msr_dcd)) {
   1475 		/*
   1476 		 * Inform the tty layer that carrier detect changed.
   1477 		 */
   1478 		(void) (*tp->t_linesw->l_modem)(tp, ISSET(msr, MSTS_DCD));
   1479 	}
   1480 
   1481 	if (ISSET(delta, sc->sc_msr_cts)) {
   1482 		/* Block or unblock output according to flow control. */
   1483 		if (ISSET(msr, sc->sc_msr_cts)) {
   1484 			sc->sc_tx_stopped = 0;
   1485 			(*tp->t_linesw->l_start)(tp);
   1486 		} else {
   1487 			sc->sc_tx_stopped = 1;
   1488 		}
   1489 	}
   1490 
   1491 	if (sscom_debug)
   1492 		sscomstatus(sc, "sscom_stsoft");
   1493 }
   1494 
   1495 void
   1496 sscomsoft(void *arg)
   1497 {
   1498 	struct sscom_softc *sc = arg;
   1499 	struct tty *tp;
   1500 
   1501 	if (SSCOM_ISALIVE(sc) == 0)
   1502 		return;
   1503 
   1504 	{
   1505 		tp = sc->sc_tty;
   1506 
   1507 		if (sc->sc_rx_ready) {
   1508 			sc->sc_rx_ready = 0;
   1509 			sscom_rxsoft(sc, tp);
   1510 		}
   1511 
   1512 		if (sc->sc_st_check) {
   1513 			sc->sc_st_check = 0;
   1514 			sscom_stsoft(sc, tp);
   1515 		}
   1516 
   1517 		if (sc->sc_tx_done) {
   1518 			sc->sc_tx_done = 0;
   1519 			sscom_txsoft(sc, tp);
   1520 		}
   1521 	}
   1522 }
   1523 
   1524 
   1525 int
   1526 sscomrxintr(void *arg)
   1527 {
   1528 	struct sscom_softc *sc = arg;
   1529 	bus_space_tag_t iot = sc->sc_iot;
   1530 	bus_space_handle_t ioh = sc->sc_ioh;
   1531 	u_char *put, *end;
   1532 	u_int cc;
   1533 
   1534 	if (SSCOM_ISALIVE(sc) == 0)
   1535 		return 0;
   1536 
   1537 	SSCOM_LOCK(sc);
   1538 
   1539 	end = sc->sc_ebuf;
   1540 	put = sc->sc_rbput;
   1541 	cc = sc->sc_rbavail;
   1542 
   1543 	do {
   1544 		u_char	msts, delta;
   1545 		u_char  uerstat;
   1546 		uint16_t ufstat;
   1547 
   1548 		ufstat = bus_space_read_2(iot, ioh, SSCOM_UFSTAT);
   1549 
   1550 		/* XXX: break interrupt with no character? */
   1551 
   1552 		if ( (ufstat & (UFSTAT_RXCOUNT|UFSTAT_RXFULL)) &&
   1553 		    !ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
   1554 
   1555 			while (cc > 0) {
   1556 				int cn_trapped = 0;
   1557 
   1558 				/* get status and received character.
   1559 				   read status register first */
   1560 				uerstat = sscom_geterr(iot, ioh);
   1561 				put[0] = sscom_getc(iot, ioh);
   1562 
   1563 				if (ISSET(uerstat, UERSTAT_BREAK)) {
   1564 					int con_trapped = 0;
   1565 					cn_check_magic(sc->sc_tty->t_dev,
   1566 					    CNC_BREAK, sscom_cnm_state);
   1567 					if (con_trapped)
   1568 						continue;
   1569 #if defined(KGDB)
   1570 					if (ISSET(sc->sc_hwflags,
   1571 					    SSCOM_HW_KGDB)) {
   1572 						kgdb_connect(1);
   1573 						continue;
   1574 					}
   1575 #endif
   1576 				}
   1577 
   1578 				put[1] = uerstat;
   1579 				cn_check_magic(sc->sc_tty->t_dev,
   1580 					       put[0], sscom_cnm_state);
   1581 				if (!cn_trapped) {
   1582 					put += 2;
   1583 					if (put >= end)
   1584 						put = sc->sc_rbuf;
   1585 					cc--;
   1586 				}
   1587 
   1588 				ufstat = bus_space_read_2(iot, ioh, SSCOM_UFSTAT);
   1589 				if ( (ufstat & (UFSTAT_RXFULL|UFSTAT_RXCOUNT)) == 0 )
   1590 					break;
   1591 			}
   1592 
   1593 			/*
   1594 			 * Current string of incoming characters ended because
   1595 			 * no more data was available or we ran out of space.
   1596 			 * Schedule a receive event if any data was received.
   1597 			 * If we're out of space, turn off receive interrupts.
   1598 			 */
   1599 			sc->sc_rbput = put;
   1600 			sc->sc_rbavail = cc;
   1601 			if (!ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED))
   1602 				sc->sc_rx_ready = 1;
   1603 
   1604 			/*
   1605 			 * See if we are in danger of overflowing a buffer. If
   1606 			 * so, use hardware flow control to ease the pressure.
   1607 			 */
   1608 			if (!ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED) &&
   1609 			    cc < sc->sc_r_hiwat) {
   1610 				SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
   1611 				sscom_hwiflow(sc);
   1612 			}
   1613 
   1614 			/*
   1615 			 * If we're out of space, disable receive interrupts
   1616 			 * until the queue has drained a bit.
   1617 			 */
   1618 			if (!cc) {
   1619 				SET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
   1620 				sscom_disable_rxint(sc);
   1621 				sc->sc_ucon &= ~UCON_ERRINT;
   1622 				bus_space_write_2(iot, ioh, SSCOM_UCON, sc->sc_ucon);
   1623 			}
   1624 		}
   1625 
   1626 
   1627 		msts = sc->read_modem_status(sc);
   1628 		delta = msts ^ sc->sc_msts;
   1629 		sc->sc_msts = msts;
   1630 
   1631 #ifdef notyet
   1632 		/*
   1633 		 * Pulse-per-second (PSS) signals on edge of DCD?
   1634 		 * Process these even if line discipline is ignoring DCD.
   1635 		 */
   1636 		if (delta & sc->sc_ppsmask) {
   1637 			struct timeval tv;
   1638 		    	if ((msr & sc->sc_ppsmask) == sc->sc_ppsassert) {
   1639 				/* XXX nanotime() */
   1640 				microtime(&tv);
   1641 				TIMEVAL_TO_TIMESPEC(&tv,
   1642 				    &sc->ppsinfo.assert_timestamp);
   1643 				if (sc->ppsparam.mode & PPS_OFFSETASSERT) {
   1644 					timespecadd(&sc->ppsinfo.assert_timestamp,
   1645 					    &sc->ppsparam.assert_offset,
   1646 						    &sc->ppsinfo.assert_timestamp);
   1647 				}
   1648 
   1649 #ifdef PPS_SYNC
   1650 				if (sc->ppsparam.mode & PPS_HARDPPSONASSERT)
   1651 					hardpps(&tv, tv.tv_usec);
   1652 #endif
   1653 				sc->ppsinfo.assert_sequence++;
   1654 				sc->ppsinfo.current_mode = sc->ppsparam.mode;
   1655 
   1656 			} else if ((msr & sc->sc_ppsmask) == sc->sc_ppsclear) {
   1657 				/* XXX nanotime() */
   1658 				microtime(&tv);
   1659 				TIMEVAL_TO_TIMESPEC(&tv,
   1660 				    &sc->ppsinfo.clear_timestamp);
   1661 				if (sc->ppsparam.mode & PPS_OFFSETCLEAR) {
   1662 					timespecadd(&sc->ppsinfo.clear_timestamp,
   1663 					    &sc->ppsparam.clear_offset,
   1664 					    &sc->ppsinfo.clear_timestamp);
   1665 				}
   1666 
   1667 #ifdef PPS_SYNC
   1668 				if (sc->ppsparam.mode & PPS_HARDPPSONCLEAR)
   1669 					hardpps(&tv, tv.tv_usec);
   1670 #endif
   1671 				sc->ppsinfo.clear_sequence++;
   1672 				sc->ppsinfo.current_mode = sc->ppsparam.mode;
   1673 			}
   1674 		}
   1675 #endif
   1676 
   1677 		/*
   1678 		 * Process normal status changes
   1679 		 */
   1680 		if (ISSET(delta, sc->sc_msr_mask)) {
   1681 			SET(sc->sc_msr_delta, delta);
   1682 
   1683 			/*
   1684 			 * Stop output immediately if we lose the output
   1685 			 * flow control signal or carrier detect.
   1686 			 */
   1687 			if (ISSET(~msts, sc->sc_msr_mask)) {
   1688 				sc->sc_tbc = 0;
   1689 				sc->sc_heldtbc = 0;
   1690 #ifdef SSCOM_DEBUG
   1691 				if (sscom_debug)
   1692 					sscomstatus(sc, "sscomintr  ");
   1693 #endif
   1694 			}
   1695 
   1696 			sc->sc_st_check = 1;
   1697 		}
   1698 
   1699 		/*
   1700 		 * Done handling any receive interrupts.
   1701 		 */
   1702 
   1703 		/*
   1704 		 * If we've delayed a parameter change, do it
   1705 		 * now, and restart * output.
   1706 		 */
   1707 		if ((ufstat & UFSTAT_TXCOUNT) == 0) {
   1708 			/* XXX: we should check transmitter empty also */
   1709 
   1710 			if (sc->sc_heldchange) {
   1711 				sscom_loadchannelregs(sc);
   1712 				sc->sc_heldchange = 0;
   1713 				sc->sc_tbc = sc->sc_heldtbc;
   1714 				sc->sc_heldtbc = 0;
   1715 			}
   1716 		}
   1717 
   1718 
   1719 	} while (0);
   1720 
   1721 	SSCOM_UNLOCK(sc);
   1722 
   1723 	/* Wake up the poller. */
   1724 	softint_schedule(sc->sc_si);
   1725 
   1726 #if NRND > 0 && defined(RND_COM)
   1727 	rnd_add_uint32(&sc->rnd_source, iir | rsr);
   1728 #endif
   1729 
   1730 	return 1;
   1731 }
   1732 
   1733 int
   1734 sscomtxintr(void *arg)
   1735 {
   1736 	struct sscom_softc *sc = arg;
   1737 	bus_space_tag_t iot = sc->sc_iot;
   1738 	bus_space_handle_t ioh = sc->sc_ioh;
   1739 	uint16_t ufstat;
   1740 
   1741 	if (SSCOM_ISALIVE(sc) == 0)
   1742 		return 0;
   1743 
   1744 	SSCOM_LOCK(sc);
   1745 
   1746 	ufstat = bus_space_read_2(iot, ioh, SSCOM_UFSTAT);
   1747 
   1748 	/*
   1749 	 * If we've delayed a parameter change, do it
   1750 	 * now, and restart * output.
   1751 	 */
   1752 	if (sc->sc_heldchange && (ufstat & UFSTAT_TXCOUNT) == 0) {
   1753 		/* XXX: we should check transmitter empty also */
   1754 		sscom_loadchannelregs(sc);
   1755 		sc->sc_heldchange = 0;
   1756 		sc->sc_tbc = sc->sc_heldtbc;
   1757 		sc->sc_heldtbc = 0;
   1758 	}
   1759 
   1760 	/*
   1761 	 * See if data can be transmitted as well. Schedule tx
   1762 	 * done event if no data left and tty was marked busy.
   1763 	 */
   1764 	if (!ISSET(ufstat,UFSTAT_TXFULL)) {
   1765 		/*
   1766 		 * Output the next chunk of the contiguous
   1767 		 * buffer, if any.
   1768 		 */
   1769 		if (sc->sc_tbc > 0) {
   1770 			__sscom_output_chunk(sc, ufstat);
   1771 		}
   1772 		else {
   1773 			/*
   1774 			 * Disable transmit sscompletion
   1775 			 * interrupts if necessary.
   1776 			 */
   1777 			if (sc->sc_hwflags & SSCOM_HW_TXINT)
   1778 				sscom_disable_txint(sc);
   1779 			if (sc->sc_tx_busy) {
   1780 				sc->sc_tx_busy = 0;
   1781 				sc->sc_tx_done = 1;
   1782 			}
   1783 		}
   1784 	}
   1785 
   1786 	SSCOM_UNLOCK(sc);
   1787 
   1788 	/* Wake up the poller. */
   1789 	softint_schedule(sc->sc_si);
   1790 
   1791 #if NRND > 0 && defined(RND_COM)
   1792 	rnd_add_uint32(&sc->rnd_source, iir | rsr);
   1793 #endif
   1794 
   1795 	return 1;
   1796 }
   1797 
   1798 
   1799 #if defined(KGDB) || defined(SSCOM0CONSOLE) || defined(SSCOM1CONSOLE)
   1800 /*
   1801  * Initialize UART for use as console or KGDB line.
   1802  */
   1803 static int
   1804 sscom_init(bus_space_tag_t iot, const struct sscom_uart_info *config,
   1805     int rate, int frequency, tcflag_t cflag, bus_space_handle_t *iohp)
   1806 {
   1807 	bus_space_handle_t ioh;
   1808 	bus_addr_t iobase = config->iobase;
   1809 
   1810 	if (bus_space_map(iot, iobase, SSCOM_SIZE, 0, &ioh))
   1811 		return ENOMEM; /* ??? */
   1812 
   1813 	bus_space_write_2(iot, ioh, SSCOM_UCON, 0);
   1814 	bus_space_write_1(iot, ioh, SSCOM_UFCON,
   1815 	    UFCON_TXTRIGGER_8 | UFCON_RXTRIGGER_8 |
   1816 	    UFCON_TXFIFO_RESET | UFCON_RXFIFO_RESET |
   1817 	    UFCON_FIFO_ENABLE );
   1818 	/* tx/rx fifo reset are auto-cleared */
   1819 
   1820 	rate = sscomspeed(rate, frequency);
   1821 	bus_space_write_2(iot, ioh, SSCOM_UBRDIV, rate);
   1822 	bus_space_write_2(iot, ioh, SSCOM_ULCON, cflag2lcr(cflag));
   1823 
   1824 	/* enable UART */
   1825 	bus_space_write_2(iot, ioh, SSCOM_UCON,
   1826 	    UCON_TXMODE_INT|UCON_RXMODE_INT);
   1827 	bus_space_write_2(iot, ioh, SSCOM_UMCON, UMCON_RTS);
   1828 
   1829 	*iohp = ioh;
   1830 	return 0;
   1831 }
   1832 
   1833 #endif
   1834 
   1835 #if defined(SSCOM0CONSOLE) || defined(SSCOM1CONSOLE)
   1836 /*
   1837  * Following are all routines needed for SSCOM to act as console
   1838  */
   1839 struct consdev sscomcons = {
   1840 	NULL, NULL, sscomcngetc, sscomcnputc, sscomcnpollc, NULL,
   1841 	NULL, NULL, NODEV, CN_NORMAL
   1842 };
   1843 
   1844 
   1845 int
   1846 sscom_cnattach(bus_space_tag_t iot, const struct sscom_uart_info *config,
   1847     int rate, int frequency, tcflag_t cflag)
   1848 {
   1849 	int res;
   1850 
   1851 	res = sscom_init(iot, config, rate, frequency, cflag, &sscomconsioh);
   1852 	if (res)
   1853 		return res;
   1854 
   1855 	cn_tab = &sscomcons;
   1856 	cn_init_magic(&sscom_cnm_state);
   1857 	cn_set_magic("\047\001"); /* default magic is BREAK */
   1858 
   1859 	sscomconstag = iot;
   1860 	sscomconsunit = config->unit;
   1861 	sscomconsrate = rate;
   1862 	sscomconscflag = cflag;
   1863 
   1864 	return 0;
   1865 }
   1866 
   1867 void
   1868 sscom_cndetach(void)
   1869 {
   1870 	bus_space_unmap(sscomconstag, sscomconsioh, SSCOM_SIZE);
   1871 	sscomconstag = NULL;
   1872 
   1873 	cn_tab = NULL;
   1874 }
   1875 
   1876 /*
   1877  * The read-ahead code is so that you can detect pending in-band
   1878  * cn_magic in polled mode while doing output rather than having to
   1879  * wait until the kernel decides it needs input.
   1880  */
   1881 
   1882 #define MAX_READAHEAD	20
   1883 static int sscom_readahead[MAX_READAHEAD];
   1884 static int sscom_readaheadcount = 0;
   1885 
   1886 int
   1887 sscomcngetc(dev_t dev)
   1888 {
   1889 	int s = splserial();
   1890 	u_char stat, c;
   1891 
   1892 	/* got a character from reading things earlier */
   1893 	if (sscom_readaheadcount > 0) {
   1894 		int i;
   1895 
   1896 		c = sscom_readahead[0];
   1897 		for (i = 1; i < sscom_readaheadcount; i++) {
   1898 			sscom_readahead[i-1] = sscom_readahead[i];
   1899 		}
   1900 		sscom_readaheadcount--;
   1901 		splx(s);
   1902 		return c;
   1903 	}
   1904 
   1905 	/* block until a character becomes available */
   1906 	while (!sscom_rxrdy(sscomconstag, sscomconsioh))
   1907 		;
   1908 
   1909 	c = sscom_getc(sscomconstag, sscomconsioh);
   1910 	stat = sscom_geterr(sscomconstag, sscomconsioh);
   1911 	{
   1912 		int cn_trapped = 0; /* unused */
   1913 #ifdef DDB
   1914 		extern int db_active;
   1915 		if (!db_active)
   1916 #endif
   1917 			cn_check_magic(dev, c, sscom_cnm_state);
   1918 	}
   1919 	splx(s);
   1920 	return c;
   1921 }
   1922 
   1923 /*
   1924  * Console kernel output character routine.
   1925  */
   1926 void
   1927 sscomcnputc(dev_t dev, int c)
   1928 {
   1929 	int s = splserial();
   1930 	int timo;
   1931 
   1932 	int cin, stat;
   1933 	if (sscom_readaheadcount < MAX_READAHEAD &&
   1934 	    sscom_rxrdy(sscomconstag, sscomconsioh)) {
   1935 
   1936 		int cn_trapped = 0;
   1937 		cin = sscom_getc(sscomconstag, sscomconsioh);
   1938 		stat = sscom_geterr(sscomconstag, sscomconsioh);
   1939 		cn_check_magic(dev, cin, sscom_cnm_state);
   1940 		sscom_readahead[sscom_readaheadcount++] = cin;
   1941 	}
   1942 
   1943 	/* wait for any pending transmission to finish */
   1944 	timo = 150000;
   1945 	while (ISSET(bus_space_read_2(sscomconstag, sscomconsioh, SSCOM_UFSTAT),
   1946 		   UFSTAT_TXFULL) && --timo)
   1947 		continue;
   1948 
   1949 	bus_space_write_1(sscomconstag, sscomconsioh, SSCOM_UTXH, c);
   1950 	SSCOM_BARRIER(sscomconstag, sscomconsioh, BR | BW);
   1951 
   1952 #if 0
   1953 	/* wait for this transmission to complete */
   1954 	timo = 1500000;
   1955 	while (!ISSET(bus_space_read_1(sscomconstag, sscomconsioh, SSCOM_UTRSTAT),
   1956 		   UTRSTAT_TXEMPTY) && --timo)
   1957 		continue;
   1958 #endif
   1959 	splx(s);
   1960 }
   1961 
   1962 void
   1963 sscomcnpollc(dev_t dev, int on)
   1964 {
   1965 
   1966 }
   1967 
   1968 #endif /* SSCOM0CONSOLE||SSCOM1CONSOLE */
   1969 
   1970 #ifdef KGDB
   1971 int
   1972 sscom_kgdb_attach(bus_space_tag_t iot, const struct sscom_uart_info *config,
   1973     int rate, int frequency, tcflag_t cflag)
   1974 {
   1975 	int res;
   1976 
   1977 	if (iot == sscomconstag && config->unit == sscomconsunit) {
   1978 		printf( "console==kgdb_port (%d): kgdb disabled\n", sscomconsunit);
   1979 		return EBUSY; /* cannot share with console */
   1980 	}
   1981 
   1982 	res = sscom_init(iot, config, rate, frequency, cflag, &sscom_kgdb_ioh);
   1983 	if (res)
   1984 		return res;
   1985 
   1986 	kgdb_attach(sscom_kgdb_getc, sscom_kgdb_putc, NULL);
   1987 	kgdb_dev = 123; /* unneeded, only to satisfy some tests */
   1988 
   1989 	sscom_kgdb_iot = iot;
   1990 	sscom_kgdb_unit = config->unit;
   1991 
   1992 	return 0;
   1993 }
   1994 
   1995 /* ARGSUSED */
   1996 int
   1997 sscom_kgdb_getc(void *arg)
   1998 {
   1999 	int c, stat;
   2000 
   2001 	/* block until a character becomes available */
   2002 	while (!sscom_rxrdy(sscom_kgdb_iot, sscom_kgdb_ioh))
   2003 		;
   2004 
   2005 	c = sscom_getc(sscom_kgdb_iot, sscom_kgdb_ioh);
   2006 	stat = sscom_geterr(sscom_kgdb_iot, sscom_kgdb_ioh);
   2007 
   2008 	return c;
   2009 }
   2010 
   2011 /* ARGSUSED */
   2012 void
   2013 sscom_kgdb_putc(void *arg, int c)
   2014 {
   2015 	int timo;
   2016 
   2017 	/* wait for any pending transmission to finish */
   2018 	timo = 150000;
   2019 	while (ISSET(bus_space_read_2(sscom_kgdb_iot, sscom_kgdb_ioh,
   2020 	    SSCOM_UFSTAT), UFSTAT_TXFULL) && --timo)
   2021 		continue;
   2022 
   2023 	bus_space_write_1(sscom_kgdb_iot, sscom_kgdb_ioh, SSCOM_UTXH, c);
   2024 	SSCOM_BARRIER(sscom_kgdb_iot, sscom_kgdb_ioh, BR | BW);
   2025 
   2026 #if 0
   2027 	/* wait for this transmission to complete */
   2028 	timo = 1500000;
   2029 	while (!ISSET(bus_space_read_1(sscom_kgdb_iot, sscom_kgdb_ioh,
   2030 	    SSCOM_UTRSTAT), UTRSTAT_TXEMPTY) && --timo)
   2031 		continue;
   2032 #endif
   2033 }
   2034 #endif /* KGDB */
   2035 
   2036 /* helper function to identify the sscom ports used by
   2037  console or KGDB (and not yet autoconf attached) */
   2038 int
   2039 sscom_is_console(bus_space_tag_t iot, int unit,
   2040     bus_space_handle_t *ioh)
   2041 {
   2042 	bus_space_handle_t help;
   2043 
   2044 	if (!sscomconsattached &&
   2045 	    iot == sscomconstag && unit == sscomconsunit)
   2046 		help = sscomconsioh;
   2047 #ifdef KGDB
   2048 	else if (!sscom_kgdb_attached &&
   2049 	    iot == sscom_kgdb_iot && unit == sscom_kgdb_unit)
   2050 		help = sscom_kgdb_ioh;
   2051 #endif
   2052 	else
   2053 		return 0;
   2054 
   2055 	if (ioh)
   2056 		*ioh = help;
   2057 	return 1;
   2058 }
   2059