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com.c revision 1.210
      1 /*	$NetBSD: com.c,v 1.210 2003/06/14 17:01:06 thorpej Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1998, 1999 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Charles M. Hannum.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  * 3. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *        This product includes software developed by the NetBSD
     21  *        Foundation, Inc. and its contributors.
     22  * 4. Neither the name of The NetBSD Foundation nor the names of its
     23  *    contributors may be used to endorse or promote products derived
     24  *    from this software without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     36  * POSSIBILITY OF SUCH DAMAGE.
     37  */
     38 
     39 /*
     40  * Copyright (c) 1991 The Regents of the University of California.
     41  * All rights reserved.
     42  *
     43  * Redistribution and use in source and binary forms, with or without
     44  * modification, are permitted provided that the following conditions
     45  * are met:
     46  * 1. Redistributions of source code must retain the above copyright
     47  *    notice, this list of conditions and the following disclaimer.
     48  * 2. Redistributions in binary form must reproduce the above copyright
     49  *    notice, this list of conditions and the following disclaimer in the
     50  *    documentation and/or other materials provided with the distribution.
     51  * 3. All advertising materials mentioning features or use of this software
     52  *    must display the following acknowledgement:
     53  *	This product includes software developed by the University of
     54  *	California, Berkeley and its contributors.
     55  * 4. Neither the name of the University nor the names of its contributors
     56  *    may be used to endorse or promote products derived from this software
     57  *    without specific prior written permission.
     58  *
     59  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     60  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     61  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     62  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     63  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     64  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     65  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     66  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     67  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     68  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     69  * SUCH DAMAGE.
     70  *
     71  *	@(#)com.c	7.5 (Berkeley) 5/16/91
     72  */
     73 
     74 /*
     75  * COM driver, uses National Semiconductor NS16450/NS16550AF UART
     76  * Supports automatic hardware flow control on StarTech ST16C650A UART
     77  */
     78 
     79 #include <sys/cdefs.h>
     80 __KERNEL_RCSID(0, "$NetBSD: com.c,v 1.210 2003/06/14 17:01:06 thorpej Exp $");
     81 
     82 #include "opt_com.h"
     83 #include "opt_ddb.h"
     84 #include "opt_kgdb.h"
     85 
     86 #include "rnd.h"
     87 #if NRND > 0 && defined(RND_COM)
     88 #include <sys/rnd.h>
     89 #endif
     90 
     91 /*
     92  * Override cnmagic(9) macro before including <sys/systm.h>.
     93  * We need to know if cn_check_magic triggered debugger, so set a flag.
     94  * Callers of cn_check_magic must declare int cn_trapped = 0;
     95  * XXX: this is *ugly*!
     96  */
     97 #define cn_trap()				\
     98 	do {					\
     99 		console_debugger();		\
    100 		cn_trapped = 1;			\
    101 	} while (/* CONSTCOND */ 0)
    102 
    103 #include <sys/param.h>
    104 #include <sys/systm.h>
    105 #include <sys/ioctl.h>
    106 #include <sys/select.h>
    107 #include <sys/tty.h>
    108 #include <sys/proc.h>
    109 #include <sys/user.h>
    110 #include <sys/conf.h>
    111 #include <sys/file.h>
    112 #include <sys/uio.h>
    113 #include <sys/kernel.h>
    114 #include <sys/syslog.h>
    115 #include <sys/device.h>
    116 #include <sys/malloc.h>
    117 #include <sys/timepps.h>
    118 #include <sys/vnode.h>
    119 
    120 #include <machine/intr.h>
    121 #include <machine/bus.h>
    122 
    123 #include <dev/ic/comreg.h>
    124 #include <dev/ic/comvar.h>
    125 #include <dev/ic/ns16550reg.h>
    126 #include <dev/ic/st16650reg.h>
    127 #ifdef COM_HAYESP
    128 #include <dev/ic/hayespreg.h>
    129 #endif
    130 #define	com_lcr	com_cfcr
    131 #include <dev/cons.h>
    132 
    133 #ifdef COM_HAYESP
    134 int comprobeHAYESP(bus_space_handle_t hayespioh, struct com_softc *sc);
    135 #endif
    136 
    137 static void com_enable_debugport(struct com_softc *);
    138 
    139 void	com_config(struct com_softc *);
    140 void	com_shutdown(struct com_softc *);
    141 int	comspeed(long, long, int);
    142 static	u_char	cflag2lcr(tcflag_t);
    143 int	comparam(struct tty *, struct termios *);
    144 void	comstart(struct tty *);
    145 int	comhwiflow(struct tty *, int);
    146 
    147 void	com_loadchannelregs(struct com_softc *);
    148 void	com_hwiflow(struct com_softc *);
    149 void	com_break(struct com_softc *, int);
    150 void	com_modem(struct com_softc *, int);
    151 void	tiocm_to_com(struct com_softc *, u_long, int);
    152 int	com_to_tiocm(struct com_softc *);
    153 void	com_iflush(struct com_softc *);
    154 
    155 int	com_common_getc(dev_t, bus_space_tag_t, bus_space_handle_t);
    156 void	com_common_putc(dev_t, bus_space_tag_t, bus_space_handle_t, int);
    157 
    158 int	cominit(bus_space_tag_t, bus_addr_t, int, int, int, tcflag_t,
    159 	    bus_space_handle_t *);
    160 
    161 int	comcngetc(dev_t);
    162 void	comcnputc(dev_t, int);
    163 void	comcnpollc(dev_t, int);
    164 
    165 #define	integrate	static inline
    166 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
    167 void 	comsoft(void *);
    168 #else
    169 #ifndef __NO_SOFT_SERIAL_INTERRUPT
    170 void 	comsoft(void);
    171 #else
    172 void 	comsoft(void *);
    173 struct callout comsoft_callout = CALLOUT_INITIALIZER;
    174 #endif
    175 #endif
    176 integrate void com_rxsoft(struct com_softc *, struct tty *);
    177 integrate void com_txsoft(struct com_softc *, struct tty *);
    178 integrate void com_stsoft(struct com_softc *, struct tty *);
    179 integrate void com_schedrx(struct com_softc *);
    180 void	comdiag(void *);
    181 
    182 extern struct cfdriver com_cd;
    183 
    184 dev_type_open(comopen);
    185 dev_type_close(comclose);
    186 dev_type_read(comread);
    187 dev_type_write(comwrite);
    188 dev_type_ioctl(comioctl);
    189 dev_type_stop(comstop);
    190 dev_type_tty(comtty);
    191 dev_type_poll(compoll);
    192 
    193 const struct cdevsw com_cdevsw = {
    194 	comopen, comclose, comread, comwrite, comioctl,
    195 	comstop, comtty, compoll, 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 com_rbuf_size = COM_RING_SIZE;
    203 
    204 /* Stop input when 3/4 of the ring is full; restart when only 1/4 is full. */
    205 u_int com_rbuf_hiwat = (COM_RING_SIZE * 1) / 4;
    206 u_int com_rbuf_lowat = (COM_RING_SIZE * 3) / 4;
    207 
    208 static bus_addr_t	comconsaddr;
    209 static bus_space_tag_t comconstag;
    210 static bus_space_handle_t comconsioh;
    211 static int	comconsattached;
    212 static int comconsrate;
    213 static tcflag_t comconscflag;
    214 static struct cnm_state com_cnm_state;
    215 
    216 static int ppscap =
    217 	PPS_TSFMT_TSPEC |
    218 	PPS_CAPTUREASSERT |
    219 	PPS_CAPTURECLEAR |
    220 #ifdef  PPS_SYNC
    221 	PPS_HARDPPSONASSERT | PPS_HARDPPSONCLEAR |
    222 #endif	/* PPS_SYNC */
    223 	PPS_OFFSETASSERT | PPS_OFFSETCLEAR;
    224 
    225 #ifndef __HAVE_GENERIC_SOFT_INTERRUPTS
    226 #ifdef __NO_SOFT_SERIAL_INTERRUPT
    227 volatile int	com_softintr_scheduled;
    228 #endif
    229 #endif
    230 
    231 #ifdef KGDB
    232 #include <sys/kgdb.h>
    233 
    234 static bus_addr_t com_kgdb_addr;
    235 static bus_space_tag_t com_kgdb_iot;
    236 static bus_space_handle_t com_kgdb_ioh;
    237 static int com_kgdb_attached;
    238 
    239 int	com_kgdb_getc(void *);
    240 void	com_kgdb_putc(void *, int);
    241 #endif /* KGDB */
    242 
    243 #define	COMUNIT_MASK	0x7ffff
    244 #define	COMDIALOUT_MASK	0x80000
    245 
    246 #define	COMUNIT(x)	(minor(x) & COMUNIT_MASK)
    247 #define	COMDIALOUT(x)	(minor(x) & COMDIALOUT_MASK)
    248 
    249 #define	COM_ISALIVE(sc)	((sc)->enabled != 0 && \
    250 			 ISSET((sc)->sc_dev.dv_flags, DVF_ACTIVE))
    251 
    252 #define	BR	BUS_SPACE_BARRIER_READ
    253 #define	BW	BUS_SPACE_BARRIER_WRITE
    254 #define COM_BARRIER(t, h, f) bus_space_barrier((t), (h), 0, COM_NPORTS, (f))
    255 
    256 #if (defined(MULTIPROCESSOR) || defined(LOCKDEBUG)) && defined(COM_MPLOCK)
    257 
    258 #define COM_LOCK(sc) simple_lock(&(sc)->sc_lock)
    259 #define COM_UNLOCK(sc) simple_unlock(&(sc)->sc_lock)
    260 
    261 #else
    262 
    263 #define COM_LOCK(sc)
    264 #define COM_UNLOCK(sc)
    265 
    266 #endif
    267 
    268 /*ARGSUSED*/
    269 int
    270 comspeed(long speed, long frequency, int type)
    271 {
    272 #define	divrnd(n, q)	(((n)*2/(q)+1)/2)	/* divide and round off */
    273 
    274 	int x, err;
    275 
    276 #if 0
    277 	if (speed == 0)
    278 		return (0);
    279 #endif
    280 	if (speed <= 0)
    281 		return (-1);
    282 	x = divrnd(frequency / 16, speed);
    283 	if (x <= 0)
    284 		return (-1);
    285 	err = divrnd(((quad_t)frequency) * 1000 / 16, speed * x) - 1000;
    286 	if (err < 0)
    287 		err = -err;
    288 	if (err > COM_TOLERANCE)
    289 		return (-1);
    290 	return (x);
    291 
    292 #undef	divrnd
    293 }
    294 
    295 #ifdef COM_DEBUG
    296 int	com_debug = 0;
    297 
    298 void comstatus(struct com_softc *, char *);
    299 void
    300 comstatus(struct com_softc *sc, char *str)
    301 {
    302 	struct tty *tp = sc->sc_tty;
    303 
    304 	printf("%s: %s %sclocal  %sdcd %sts_carr_on %sdtr %stx_stopped\n",
    305 	    sc->sc_dev.dv_xname, str,
    306 	    ISSET(tp->t_cflag, CLOCAL) ? "+" : "-",
    307 	    ISSET(sc->sc_msr, MSR_DCD) ? "+" : "-",
    308 	    ISSET(tp->t_state, TS_CARR_ON) ? "+" : "-",
    309 	    ISSET(sc->sc_mcr, MCR_DTR) ? "+" : "-",
    310 	    sc->sc_tx_stopped ? "+" : "-");
    311 
    312 	printf("%s: %s %scrtscts %scts %sts_ttstop  %srts %xrx_flags\n",
    313 	    sc->sc_dev.dv_xname, str,
    314 	    ISSET(tp->t_cflag, CRTSCTS) ? "+" : "-",
    315 	    ISSET(sc->sc_msr, MSR_CTS) ? "+" : "-",
    316 	    ISSET(tp->t_state, TS_TTSTOP) ? "+" : "-",
    317 	    ISSET(sc->sc_mcr, MCR_RTS) ? "+" : "-",
    318 	    sc->sc_rx_flags);
    319 }
    320 #endif
    321 
    322 int
    323 comprobe1(bus_space_tag_t iot, bus_space_handle_t ioh)
    324 {
    325 
    326 	/* force access to id reg */
    327 	bus_space_write_1(iot, ioh, com_lcr, LCR_8BITS);
    328 	bus_space_write_1(iot, ioh, com_iir, 0);
    329 	if ((bus_space_read_1(iot, ioh, com_lcr) != LCR_8BITS) ||
    330 	    (bus_space_read_1(iot, ioh, com_iir) & 0x38))
    331 		return (0);
    332 
    333 	return (1);
    334 }
    335 
    336 #ifdef COM_HAYESP
    337 int
    338 comprobeHAYESP(bus_space_handle_t hayespioh, struct com_softc *sc)
    339 {
    340 	char	val, dips;
    341 	int	combaselist[] = { 0x3f8, 0x2f8, 0x3e8, 0x2e8 };
    342 	bus_space_tag_t iot = sc->sc_iot;
    343 
    344 	/*
    345 	 * Hayes ESP cards have two iobases.  One is for compatibility with
    346 	 * 16550 serial chips, and at the same ISA PC base addresses.  The
    347 	 * other is for ESP-specific enhanced features, and lies at a
    348 	 * different addressing range entirely (0x140, 0x180, 0x280, or 0x300).
    349 	 */
    350 
    351 	/* Test for ESP signature */
    352 	if ((bus_space_read_1(iot, hayespioh, 0) & 0xf3) == 0)
    353 		return (0);
    354 
    355 	/*
    356 	 * ESP is present at ESP enhanced base address; unknown com port
    357 	 */
    358 
    359 	/* Get the dip-switch configurations */
    360 	bus_space_write_1(iot, hayespioh, HAYESP_CMD1, HAYESP_GETDIPS);
    361 	dips = bus_space_read_1(iot, hayespioh, HAYESP_STATUS1);
    362 
    363 	/* Determine which com port this ESP card services: bits 0,1 of  */
    364 	/*  dips is the port # (0-3); combaselist[val] is the com_iobase */
    365 	if (sc->sc_iobase != combaselist[dips & 0x03])
    366 		return (0);
    367 
    368 	printf(": ESP");
    369 
    370  	/* Check ESP Self Test bits. */
    371 	/* Check for ESP version 2.0: bits 4,5,6 == 010 */
    372 	bus_space_write_1(iot, hayespioh, HAYESP_CMD1, HAYESP_GETTEST);
    373 	val = bus_space_read_1(iot, hayespioh, HAYESP_STATUS1); /* Clear reg1 */
    374 	val = bus_space_read_1(iot, hayespioh, HAYESP_STATUS2);
    375 	if ((val & 0x70) < 0x20) {
    376 		printf("-old (%o)", val & 0x70);
    377 		/* we do not support the necessary features */
    378 		return (0);
    379 	}
    380 
    381 	/* Check for ability to emulate 16550: bit 8 == 1 */
    382 	if ((dips & 0x80) == 0) {
    383 		printf(" slave");
    384 		/* XXX Does slave really mean no 16550 support?? */
    385 		return (0);
    386 	}
    387 
    388 	/*
    389 	 * If we made it this far, we are a full-featured ESP v2.0 (or
    390 	 * better), at the correct com port address.
    391 	 */
    392 
    393 	sc->sc_type = COM_TYPE_HAYESP;
    394 	printf(", 1024 byte fifo\n");
    395 	return (1);
    396 }
    397 #endif
    398 
    399 static void
    400 com_enable_debugport(struct com_softc *sc)
    401 {
    402 	int s;
    403 
    404 	/* Turn on line break interrupt, set carrier. */
    405 	s = splserial();
    406 	COM_LOCK(sc);
    407 	sc->sc_ier = IER_ERXRDY;
    408 #ifdef COM_PXA2X0
    409 	if (sc->sc_type == COM_TYPE_PXA2x0)
    410 		sc->sc_ier |= IER_EUART | IER_ERXTOUT;
    411 #endif
    412 	bus_space_write_1(sc->sc_iot, sc->sc_ioh, com_ier, sc->sc_ier);
    413 	SET(sc->sc_mcr, MCR_DTR | MCR_RTS);
    414 	bus_space_write_1(sc->sc_iot, sc->sc_ioh, com_mcr, sc->sc_mcr);
    415 	COM_UNLOCK(sc);
    416 	splx(s);
    417 }
    418 
    419 void
    420 com_attach_subr(struct com_softc *sc)
    421 {
    422 	bus_addr_t iobase = sc->sc_iobase;
    423 	bus_space_tag_t iot = sc->sc_iot;
    424 	bus_space_handle_t ioh = sc->sc_ioh;
    425 	struct tty *tp;
    426 #ifdef COM16650
    427 	u_int8_t lcr;
    428 #endif
    429 #ifdef COM_HAYESP
    430 	int	hayesp_ports[] = { 0x140, 0x180, 0x280, 0x300, 0 };
    431 	int	*hayespp;
    432 #endif
    433 	const char *fifo_msg = NULL;
    434 
    435 	callout_init(&sc->sc_diag_callout);
    436 #if (defined(MULTIPROCESSOR) || defined(LOCKDEBUG)) && defined(COM_MPLOCK)
    437 	simple_lock_init(&sc->sc_lock);
    438 #endif
    439 
    440 	/* Disable interrupts before configuring the device. */
    441 #ifdef COM_PXA2X0
    442 	if (sc->sc_type == COM_TYPE_PXA2x0)
    443 		sc->sc_ier = IER_EUART;
    444 	else
    445 #endif
    446 		sc->sc_ier = 0;
    447 	bus_space_write_1(iot, ioh, com_ier, sc->sc_ier);
    448 
    449 	if (iot == comconstag && iobase == comconsaddr) {
    450 		comconsattached = 1;
    451 
    452 		/* Make sure the console is always "hardwired". */
    453 		delay(1000);			/* wait for output to finish */
    454 		SET(sc->sc_hwflags, COM_HW_CONSOLE);
    455 		SET(sc->sc_swflags, TIOCFLAG_SOFTCAR);
    456 	}
    457 
    458 #ifdef COM_HAYESP
    459 	sc->sc_prescaler = 0;			/* set prescaler to x1. */
    460 
    461 	/* Look for a Hayes ESP board. */
    462 	for (hayespp = hayesp_ports; *hayespp != 0; hayespp++) {
    463 		bus_space_handle_t hayespioh;
    464 
    465 #define	HAYESP_NPORTS	8			/* XXX XXX XXX ??? ??? ??? */
    466 		if (bus_space_map(iot, *hayespp, HAYESP_NPORTS, 0, &hayespioh))
    467 			continue;
    468 		if (comprobeHAYESP(hayespioh, sc)) {
    469 			sc->sc_hayespioh = hayespioh;
    470 			sc->sc_fifolen = 1024;
    471 
    472 			break;
    473 		}
    474 		bus_space_unmap(iot, hayespioh, HAYESP_NPORTS);
    475 	}
    476 	/* No ESP; look for other things. */
    477 	if (sc->sc_type != COM_TYPE_HAYESP) {
    478 #endif
    479 	sc->sc_fifolen = 1;
    480 	/* look for a NS 16550AF UART with FIFOs */
    481 	bus_space_write_1(iot, ioh, com_fifo,
    482 	    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_14);
    483 	delay(100);
    484 	if (ISSET(bus_space_read_1(iot, ioh, com_iir), IIR_FIFO_MASK)
    485 	    == IIR_FIFO_MASK)
    486 		if (ISSET(bus_space_read_1(iot, ioh, com_fifo), FIFO_TRIGGER_14)
    487 		    == FIFO_TRIGGER_14) {
    488 			SET(sc->sc_hwflags, COM_HW_FIFO);
    489 
    490 #ifdef COM16650
    491 			/*
    492 			 * IIR changes into the EFR if LCR is set to LCR_EERS
    493 			 * on 16650s. We also know IIR != 0 at this point.
    494 			 * Write 0 into the EFR, and read it. If the result
    495 			 * is 0, we have a 16650.
    496 			 *
    497 			 * Older 16650s were broken; the test to detect them
    498 			 * is taken from the Linux driver. Apparently
    499 			 * setting DLAB enable gives access to the EFR on
    500 			 * these chips.
    501 			 */
    502 			lcr = bus_space_read_1(iot, ioh, com_lcr);
    503 			bus_space_write_1(iot, ioh, com_lcr, LCR_EERS);
    504 			bus_space_write_1(iot, ioh, com_efr, 0);
    505 			if (bus_space_read_1(iot, ioh, com_efr) == 0) {
    506 				bus_space_write_1(iot, ioh, com_lcr,
    507 				    lcr | LCR_DLAB);
    508 				if (bus_space_read_1(iot, ioh, com_efr) == 0) {
    509 					CLR(sc->sc_hwflags, COM_HW_FIFO);
    510 					sc->sc_fifolen = 0;
    511 				} else {
    512 					SET(sc->sc_hwflags, COM_HW_FLOW);
    513 					sc->sc_fifolen = 32;
    514 				}
    515 			} else
    516 #endif
    517 				sc->sc_fifolen = 16;
    518 
    519 #ifdef COM16650
    520 			bus_space_write_1(iot, ioh, com_lcr, lcr);
    521 			if (sc->sc_fifolen == 0)
    522 				fifo_msg = "st16650, broken fifo";
    523 			else if (sc->sc_fifolen == 32)
    524 				fifo_msg = "st16650a, working fifo";
    525 			else
    526 #endif
    527 				fifo_msg = "ns16550a, working fifo";
    528 		} else
    529 			fifo_msg = "ns16550, broken fifo";
    530 	else
    531 		fifo_msg = "ns8250 or ns16450, no fifo";
    532 	bus_space_write_1(iot, ioh, com_fifo, 0);
    533 	/*
    534 	 * Some chips will clear down both Tx and Rx FIFOs when zero is
    535 	 * written to com_fifo. If this chip is the console, writing zero
    536 	 * results in some of the chip/FIFO description being lost, so delay
    537 	 * printing it until now.
    538 	 */
    539 	delay(10);
    540 	aprint_normal(": %s\n", fifo_msg);
    541 	if (ISSET(sc->sc_hwflags, COM_HW_TXFIFO_DISABLE)) {
    542 		sc->sc_fifolen = 1;
    543 		aprint_normal("%s: txfifo disabled\n", sc->sc_dev.dv_xname);
    544 	}
    545 #ifdef COM_HAYESP
    546 	}
    547 #endif
    548 
    549 	tp = ttymalloc();
    550 	tp->t_oproc = comstart;
    551 	tp->t_param = comparam;
    552 	tp->t_hwiflow = comhwiflow;
    553 
    554 	sc->sc_tty = tp;
    555 	sc->sc_rbuf = malloc(com_rbuf_size << 1, M_DEVBUF, M_NOWAIT);
    556 	sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
    557 	sc->sc_rbavail = com_rbuf_size;
    558 	if (sc->sc_rbuf == NULL) {
    559 		aprint_error("%s: unable to allocate ring buffer\n",
    560 		    sc->sc_dev.dv_xname);
    561 		return;
    562 	}
    563 	sc->sc_ebuf = sc->sc_rbuf + (com_rbuf_size << 1);
    564 
    565 	tty_attach(tp);
    566 
    567 	if (!ISSET(sc->sc_hwflags, COM_HW_NOIEN))
    568 		SET(sc->sc_mcr, MCR_IENABLE);
    569 
    570 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
    571 		int maj;
    572 
    573 		/* locate the major number */
    574 		maj = cdevsw_lookup_major(&com_cdevsw);
    575 
    576 		tp->t_dev = cn_tab->cn_dev = makedev(maj, sc->sc_dev.dv_unit);
    577 
    578 		aprint_normal("%s: console\n", sc->sc_dev.dv_xname);
    579 	}
    580 
    581 #ifdef KGDB
    582 	/*
    583 	 * Allow kgdb to "take over" this port.  If this is
    584 	 * not the console and is the kgdb device, it has
    585 	 * exclusive use.  If it's the console _and_ the
    586 	 * kgdb device, it doesn't.
    587 	 */
    588 	if (iot == com_kgdb_iot && iobase == com_kgdb_addr) {
    589 		if (!ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
    590 			com_kgdb_attached = 1;
    591 
    592 			SET(sc->sc_hwflags, COM_HW_KGDB);
    593 		}
    594 		aprint_normal("%s: kgdb\n", sc->sc_dev.dv_xname);
    595 	}
    596 #endif
    597 
    598 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
    599 	sc->sc_si = softintr_establish(IPL_SOFTSERIAL, comsoft, sc);
    600 #endif
    601 
    602 #if NRND > 0 && defined(RND_COM)
    603 	rnd_attach_source(&sc->rnd_source, sc->sc_dev.dv_xname,
    604 			  RND_TYPE_TTY, 0);
    605 #endif
    606 
    607 	/* if there are no enable/disable functions, assume the device
    608 	   is always enabled */
    609 	if (!sc->enable)
    610 		sc->enabled = 1;
    611 
    612 	com_config(sc);
    613 
    614 	SET(sc->sc_hwflags, COM_HW_DEV_OK);
    615 }
    616 
    617 void
    618 com_config(struct com_softc *sc)
    619 {
    620 	bus_space_tag_t iot = sc->sc_iot;
    621 	bus_space_handle_t ioh = sc->sc_ioh;
    622 
    623 	/* Disable interrupts before configuring the device. */
    624 #ifdef COM_PXA2X0
    625 	if (sc->sc_type == COM_TYPE_PXA2x0)
    626 		sc->sc_ier = IER_EUART;
    627 	else
    628 #endif
    629 		sc->sc_ier = 0;
    630 	bus_space_write_1(iot, ioh, com_ier, sc->sc_ier);
    631 
    632 #ifdef COM_HAYESP
    633 	/* Look for a Hayes ESP board. */
    634 	if (sc->sc_type == COM_TYPE_HAYESP) {
    635 		sc->sc_fifolen = 1024;
    636 
    637 		/* Set 16550 compatibility mode */
    638 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD1,
    639 				  HAYESP_SETMODE);
    640 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
    641 				  HAYESP_MODE_FIFO|HAYESP_MODE_RTS|
    642 				  HAYESP_MODE_SCALE);
    643 
    644 		/* Set RTS/CTS flow control */
    645 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD1,
    646 				  HAYESP_SETFLOWTYPE);
    647 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
    648 				  HAYESP_FLOW_RTS);
    649 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
    650 				  HAYESP_FLOW_CTS);
    651 
    652 		/* Set flow control levels */
    653 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD1,
    654 				  HAYESP_SETRXFLOW);
    655 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
    656 				  HAYESP_HIBYTE(HAYESP_RXHIWMARK));
    657 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
    658 				  HAYESP_LOBYTE(HAYESP_RXHIWMARK));
    659 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
    660 				  HAYESP_HIBYTE(HAYESP_RXLOWMARK));
    661 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
    662 				  HAYESP_LOBYTE(HAYESP_RXLOWMARK));
    663 	}
    664 #endif
    665 
    666 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE|COM_HW_KGDB))
    667 		com_enable_debugport(sc);
    668 }
    669 
    670 int
    671 com_detach(struct device *self, int flags)
    672 {
    673 	struct com_softc *sc = (struct com_softc *)self;
    674 	int maj, mn;
    675 
    676 	/* locate the major number */
    677 	maj = cdevsw_lookup_major(&com_cdevsw);
    678 
    679 	/* Nuke the vnodes for any open instances. */
    680 	mn = self->dv_unit;
    681 	vdevgone(maj, mn, mn, VCHR);
    682 
    683 	mn |= COMDIALOUT_MASK;
    684 	vdevgone(maj, mn, mn, VCHR);
    685 
    686 	if (sc->sc_rbuf == NULL) {
    687 		/*
    688 		 * Ring buffer allocation failed in the com_attach_subr,
    689 		 * only the tty is allocated, and nothing else.
    690 		 */
    691 		ttyfree(sc->sc_tty);
    692 		return 0;
    693 	}
    694 
    695 	/* Free the receive buffer. */
    696 	free(sc->sc_rbuf, M_DEVBUF);
    697 
    698 	/* Detach and free the tty. */
    699 	tty_detach(sc->sc_tty);
    700 	ttyfree(sc->sc_tty);
    701 
    702 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
    703 	/* Unhook the soft interrupt handler. */
    704 	softintr_disestablish(sc->sc_si);
    705 #endif
    706 
    707 #if NRND > 0 && defined(RND_COM)
    708 	/* Unhook the entropy source. */
    709 	rnd_detach_source(&sc->rnd_source);
    710 #endif
    711 
    712 	return (0);
    713 }
    714 
    715 int
    716 com_activate(struct device *self, enum devact act)
    717 {
    718 	struct com_softc *sc = (struct com_softc *)self;
    719 	int s, rv = 0;
    720 
    721 	s = splserial();
    722 	COM_LOCK(sc);
    723 	switch (act) {
    724 	case DVACT_ACTIVATE:
    725 		rv = EOPNOTSUPP;
    726 		break;
    727 
    728 	case DVACT_DEACTIVATE:
    729 		if (sc->sc_hwflags & (COM_HW_CONSOLE|COM_HW_KGDB)) {
    730 			rv = EBUSY;
    731 			break;
    732 		}
    733 
    734 		if (sc->disable != NULL && sc->enabled != 0) {
    735 			(*sc->disable)(sc);
    736 			sc->enabled = 0;
    737 		}
    738 		break;
    739 	}
    740 
    741 	COM_UNLOCK(sc);
    742 	splx(s);
    743 	return (rv);
    744 }
    745 
    746 void
    747 com_shutdown(struct com_softc *sc)
    748 {
    749 	struct tty *tp = sc->sc_tty;
    750 	int s;
    751 
    752 	s = splserial();
    753 	COM_LOCK(sc);
    754 
    755 	/* If we were asserting flow control, then deassert it. */
    756 	SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
    757 	com_hwiflow(sc);
    758 
    759 	/* Clear any break condition set with TIOCSBRK. */
    760 	com_break(sc, 0);
    761 
    762 	/* Turn off PPS capture on last close. */
    763 	sc->sc_ppsmask = 0;
    764 	sc->ppsparam.mode = 0;
    765 
    766 	/*
    767 	 * Hang up if necessary.  Wait a bit, so the other side has time to
    768 	 * notice even if we immediately open the port again.
    769 	 * Avoid tsleeping above splhigh().
    770 	 */
    771 	if (ISSET(tp->t_cflag, HUPCL)) {
    772 		com_modem(sc, 0);
    773 		COM_UNLOCK(sc);
    774 		splx(s);
    775 		/* XXX tsleep will only timeout */
    776 		(void) tsleep(sc, TTIPRI, ttclos, hz);
    777 		s = splserial();
    778 		COM_LOCK(sc);
    779 	}
    780 
    781 	/* Turn off interrupts. */
    782 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
    783 		sc->sc_ier = IER_ERXRDY; /* interrupt on break */
    784 #ifdef COM_PXA2X0
    785 		if (sc->sc_type == COM_TYPE_PXA2x0)
    786 			sc->sc_ier |= IER_ERXTOUT;
    787 #endif
    788 	} else
    789 		sc->sc_ier = 0;
    790 
    791 #ifdef COM_PXA2X0
    792 	if (sc->sc_type == COM_TYPE_PXA2x0)
    793 		sc->sc_ier |= IER_EUART;
    794 #endif
    795 
    796 	bus_space_write_1(sc->sc_iot, sc->sc_ioh, com_ier, sc->sc_ier);
    797 
    798 	if (sc->disable) {
    799 #ifdef DIAGNOSTIC
    800 		if (!sc->enabled)
    801 			panic("com_shutdown: not enabled?");
    802 #endif
    803 		(*sc->disable)(sc);
    804 		sc->enabled = 0;
    805 	}
    806 	COM_UNLOCK(sc);
    807 	splx(s);
    808 }
    809 
    810 int
    811 comopen(dev_t dev, int flag, int mode, struct proc *p)
    812 {
    813 	struct com_softc *sc;
    814 	struct tty *tp;
    815 	int s, s2;
    816 	int error;
    817 
    818 	sc = device_lookup(&com_cd, COMUNIT(dev));
    819 	if (sc == NULL || !ISSET(sc->sc_hwflags, COM_HW_DEV_OK) ||
    820 		sc->sc_rbuf == NULL)
    821 		return (ENXIO);
    822 
    823 	if (ISSET(sc->sc_dev.dv_flags, DVF_ACTIVE) == 0)
    824 		return (ENXIO);
    825 
    826 #ifdef KGDB
    827 	/*
    828 	 * If this is the kgdb port, no other use is permitted.
    829 	 */
    830 	if (ISSET(sc->sc_hwflags, COM_HW_KGDB))
    831 		return (EBUSY);
    832 #endif
    833 
    834 	tp = sc->sc_tty;
    835 
    836 	if (ISSET(tp->t_state, TS_ISOPEN) &&
    837 	    ISSET(tp->t_state, TS_XCLUDE) &&
    838 		p->p_ucred->cr_uid != 0)
    839 		return (EBUSY);
    840 
    841 	s = spltty();
    842 
    843 	/*
    844 	 * Do the following iff this is a first open.
    845 	 */
    846 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
    847 		struct termios t;
    848 
    849 		tp->t_dev = dev;
    850 
    851 		s2 = splserial();
    852 		COM_LOCK(sc);
    853 
    854 		if (sc->enable) {
    855 			if ((*sc->enable)(sc)) {
    856 				COM_UNLOCK(sc);
    857 				splx(s2);
    858 				splx(s);
    859 				printf("%s: device enable failed\n",
    860 				       sc->sc_dev.dv_xname);
    861 				return (EIO);
    862 			}
    863 			sc->enabled = 1;
    864 			com_config(sc);
    865 		}
    866 
    867 		/* Turn on interrupts. */
    868 		sc->sc_ier = IER_ERXRDY | IER_ERLS | IER_EMSC;
    869 #ifdef COM_PXA2X0
    870 		if (sc->sc_type == COM_TYPE_PXA2x0)
    871 			sc->sc_ier |= IER_EUART | IER_ERXTOUT;
    872 #endif
    873 		bus_space_write_1(sc->sc_iot, sc->sc_ioh, com_ier, sc->sc_ier);
    874 
    875 		/* Fetch the current modem control status, needed later. */
    876 		sc->sc_msr = bus_space_read_1(sc->sc_iot, sc->sc_ioh, com_msr);
    877 
    878 		/* Clear PPS capture state on first open. */
    879 		sc->sc_ppsmask = 0;
    880 		sc->ppsparam.mode = 0;
    881 
    882 		COM_UNLOCK(sc);
    883 		splx(s2);
    884 
    885 		/*
    886 		 * Initialize the termios status to the defaults.  Add in the
    887 		 * sticky bits from TIOCSFLAGS.
    888 		 */
    889 		t.c_ispeed = 0;
    890 		if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
    891 			t.c_ospeed = comconsrate;
    892 			t.c_cflag = comconscflag;
    893 		} else {
    894 			t.c_ospeed = TTYDEF_SPEED;
    895 			t.c_cflag = TTYDEF_CFLAG;
    896 		}
    897 		if (ISSET(sc->sc_swflags, TIOCFLAG_CLOCAL))
    898 			SET(t.c_cflag, CLOCAL);
    899 		if (ISSET(sc->sc_swflags, TIOCFLAG_CRTSCTS))
    900 			SET(t.c_cflag, CRTSCTS);
    901 		if (ISSET(sc->sc_swflags, TIOCFLAG_MDMBUF))
    902 			SET(t.c_cflag, MDMBUF);
    903 		/* Make sure comparam() will do something. */
    904 		tp->t_ospeed = 0;
    905 		(void) comparam(tp, &t);
    906 		tp->t_iflag = TTYDEF_IFLAG;
    907 		tp->t_oflag = TTYDEF_OFLAG;
    908 		tp->t_lflag = TTYDEF_LFLAG;
    909 		ttychars(tp);
    910 		ttsetwater(tp);
    911 
    912 		s2 = splserial();
    913 		COM_LOCK(sc);
    914 
    915 		/*
    916 		 * Turn on DTR.  We must always do this, even if carrier is not
    917 		 * present, because otherwise we'd have to use TIOCSDTR
    918 		 * immediately after setting CLOCAL, which applications do not
    919 		 * expect.  We always assert DTR while the device is open
    920 		 * unless explicitly requested to deassert it.
    921 		 */
    922 		com_modem(sc, 1);
    923 
    924 		/* Clear the input ring, and unblock. */
    925 		sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
    926 		sc->sc_rbavail = com_rbuf_size;
    927 		com_iflush(sc);
    928 		CLR(sc->sc_rx_flags, RX_ANY_BLOCK);
    929 		com_hwiflow(sc);
    930 
    931 #ifdef COM_DEBUG
    932 		if (com_debug)
    933 			comstatus(sc, "comopen  ");
    934 #endif
    935 
    936 		COM_UNLOCK(sc);
    937 		splx(s2);
    938 	}
    939 
    940 	splx(s);
    941 
    942 	error = ttyopen(tp, COMDIALOUT(dev), ISSET(flag, O_NONBLOCK));
    943 	if (error)
    944 		goto bad;
    945 
    946 	error = (*tp->t_linesw->l_open)(dev, tp);
    947 	if (error)
    948 		goto bad;
    949 
    950 	return (0);
    951 
    952 bad:
    953 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
    954 		/*
    955 		 * We failed to open the device, and nobody else had it opened.
    956 		 * Clean up the state as appropriate.
    957 		 */
    958 		com_shutdown(sc);
    959 	}
    960 
    961 	return (error);
    962 }
    963 
    964 int
    965 comclose(dev_t dev, int flag, int mode, struct proc *p)
    966 {
    967 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(dev));
    968 	struct tty *tp = sc->sc_tty;
    969 
    970 	/* XXX This is for cons.c. */
    971 	if (!ISSET(tp->t_state, TS_ISOPEN))
    972 		return (0);
    973 
    974 	(*tp->t_linesw->l_close)(tp, flag);
    975 	ttyclose(tp);
    976 
    977 	if (COM_ISALIVE(sc) == 0)
    978 		return (0);
    979 
    980 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
    981 		/*
    982 		 * Although we got a last close, the device may still be in
    983 		 * use; e.g. if this was the dialout node, and there are still
    984 		 * processes waiting for carrier on the non-dialout node.
    985 		 */
    986 		com_shutdown(sc);
    987 	}
    988 
    989 	return (0);
    990 }
    991 
    992 int
    993 comread(dev_t dev, struct uio *uio, int flag)
    994 {
    995 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(dev));
    996 	struct tty *tp = sc->sc_tty;
    997 
    998 	if (COM_ISALIVE(sc) == 0)
    999 		return (EIO);
   1000 
   1001 	return ((*tp->t_linesw->l_read)(tp, uio, flag));
   1002 }
   1003 
   1004 int
   1005 comwrite(dev_t dev, struct uio *uio, int flag)
   1006 {
   1007 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(dev));
   1008 	struct tty *tp = sc->sc_tty;
   1009 
   1010 	if (COM_ISALIVE(sc) == 0)
   1011 		return (EIO);
   1012 
   1013 	return ((*tp->t_linesw->l_write)(tp, uio, flag));
   1014 }
   1015 
   1016 int
   1017 compoll(dev_t dev, int events, struct proc *p)
   1018 {
   1019 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(dev));
   1020 	struct tty *tp = sc->sc_tty;
   1021 
   1022 	if (COM_ISALIVE(sc) == 0)
   1023 		return (EIO);
   1024 
   1025 	return ((*tp->t_linesw->l_poll)(tp, events, p));
   1026 }
   1027 
   1028 struct tty *
   1029 comtty(dev_t dev)
   1030 {
   1031 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(dev));
   1032 	struct tty *tp = sc->sc_tty;
   1033 
   1034 	return (tp);
   1035 }
   1036 
   1037 int
   1038 comioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct proc *p)
   1039 {
   1040 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(dev));
   1041 	struct tty *tp = sc->sc_tty;
   1042 	int error;
   1043 	int s;
   1044 
   1045 	if (COM_ISALIVE(sc) == 0)
   1046 		return (EIO);
   1047 
   1048 	error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, p);
   1049 	if (error != EPASSTHROUGH)
   1050 		return (error);
   1051 
   1052 	error = ttioctl(tp, cmd, data, flag, p);
   1053 	if (error != EPASSTHROUGH)
   1054 		return (error);
   1055 
   1056 	error = 0;
   1057 
   1058 	s = splserial();
   1059 	COM_LOCK(sc);
   1060 
   1061 	switch (cmd) {
   1062 	case TIOCSBRK:
   1063 		com_break(sc, 1);
   1064 		break;
   1065 
   1066 	case TIOCCBRK:
   1067 		com_break(sc, 0);
   1068 		break;
   1069 
   1070 	case TIOCSDTR:
   1071 		com_modem(sc, 1);
   1072 		break;
   1073 
   1074 	case TIOCCDTR:
   1075 		com_modem(sc, 0);
   1076 		break;
   1077 
   1078 	case TIOCGFLAGS:
   1079 		*(int *)data = sc->sc_swflags;
   1080 		break;
   1081 
   1082 	case TIOCSFLAGS:
   1083 		error = suser(p->p_ucred, &p->p_acflag);
   1084 		if (error)
   1085 			break;
   1086 		sc->sc_swflags = *(int *)data;
   1087 		break;
   1088 
   1089 	case TIOCMSET:
   1090 	case TIOCMBIS:
   1091 	case TIOCMBIC:
   1092 		tiocm_to_com(sc, cmd, *(int *)data);
   1093 		break;
   1094 
   1095 	case TIOCMGET:
   1096 		*(int *)data = com_to_tiocm(sc);
   1097 		break;
   1098 
   1099 	case PPS_IOC_CREATE:
   1100 		break;
   1101 
   1102 	case PPS_IOC_DESTROY:
   1103 		break;
   1104 
   1105 	case PPS_IOC_GETPARAMS: {
   1106 		pps_params_t *pp;
   1107 		pp = (pps_params_t *)data;
   1108 		*pp = sc->ppsparam;
   1109 		break;
   1110 	}
   1111 
   1112 	case PPS_IOC_SETPARAMS: {
   1113 	  	pps_params_t *pp;
   1114 		int mode;
   1115 		pp = (pps_params_t *)data;
   1116 		if (pp->mode & ~ppscap) {
   1117 			error = EINVAL;
   1118 			break;
   1119 		}
   1120 		sc->ppsparam = *pp;
   1121 	 	/*
   1122 		 * Compute msr masks from user-specified timestamp state.
   1123 		 */
   1124 		mode = sc->ppsparam.mode;
   1125 #ifdef	PPS_SYNC
   1126 		if (mode & PPS_HARDPPSONASSERT) {
   1127 			mode |= PPS_CAPTUREASSERT;
   1128 			/* XXX revoke any previous HARDPPS source */
   1129 		}
   1130 		if (mode & PPS_HARDPPSONCLEAR) {
   1131 			mode |= PPS_CAPTURECLEAR;
   1132 			/* XXX revoke any previous HARDPPS source */
   1133 		}
   1134 #endif	/* PPS_SYNC */
   1135 		switch (mode & PPS_CAPTUREBOTH) {
   1136 		case 0:
   1137 			sc->sc_ppsmask = 0;
   1138 			break;
   1139 
   1140 		case PPS_CAPTUREASSERT:
   1141 			sc->sc_ppsmask = MSR_DCD;
   1142 			sc->sc_ppsassert = MSR_DCD;
   1143 			sc->sc_ppsclear = -1;
   1144 			break;
   1145 
   1146 		case PPS_CAPTURECLEAR:
   1147 			sc->sc_ppsmask = MSR_DCD;
   1148 			sc->sc_ppsassert = -1;
   1149 			sc->sc_ppsclear = 0;
   1150 			break;
   1151 
   1152 		case PPS_CAPTUREBOTH:
   1153 			sc->sc_ppsmask = MSR_DCD;
   1154 			sc->sc_ppsassert = MSR_DCD;
   1155 			sc->sc_ppsclear = 0;
   1156 			break;
   1157 
   1158 		default:
   1159 			error = EINVAL;
   1160 			break;
   1161 		}
   1162 		break;
   1163 	}
   1164 
   1165 	case PPS_IOC_GETCAP:
   1166 		*(int*)data = ppscap;
   1167 		break;
   1168 
   1169 	case PPS_IOC_FETCH: {
   1170 		pps_info_t *pi;
   1171 		pi = (pps_info_t *)data;
   1172 		*pi = sc->ppsinfo;
   1173 		break;
   1174 	}
   1175 
   1176 	case TIOCDCDTIMESTAMP:	/* XXX old, overloaded  API used by xntpd v3 */
   1177 		/*
   1178 		 * Some GPS clocks models use the falling rather than
   1179 		 * rising edge as the on-the-second signal.
   1180 		 * The old API has no way to specify PPS polarity.
   1181 		 */
   1182 		sc->sc_ppsmask = MSR_DCD;
   1183 #ifndef PPS_TRAILING_EDGE
   1184 		sc->sc_ppsassert = MSR_DCD;
   1185 		sc->sc_ppsclear = -1;
   1186 		TIMESPEC_TO_TIMEVAL((struct timeval *)data,
   1187 		    &sc->ppsinfo.assert_timestamp);
   1188 #else
   1189 		sc->sc_ppsassert = -1
   1190 		sc->sc_ppsclear = 0;
   1191 		TIMESPEC_TO_TIMEVAL((struct timeval *)data,
   1192 		    &sc->ppsinfo.clear_timestamp);
   1193 #endif
   1194 		break;
   1195 
   1196 	default:
   1197 		error = EPASSTHROUGH;
   1198 		break;
   1199 	}
   1200 
   1201 	COM_UNLOCK(sc);
   1202 	splx(s);
   1203 
   1204 #ifdef COM_DEBUG
   1205 	if (com_debug)
   1206 		comstatus(sc, "comioctl ");
   1207 #endif
   1208 
   1209 	return (error);
   1210 }
   1211 
   1212 integrate void
   1213 com_schedrx(struct com_softc *sc)
   1214 {
   1215 
   1216 	sc->sc_rx_ready = 1;
   1217 
   1218 	/* Wake up the poller. */
   1219 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
   1220 	softintr_schedule(sc->sc_si);
   1221 #else
   1222 #ifndef __NO_SOFT_SERIAL_INTERRUPT
   1223 	setsoftserial();
   1224 #else
   1225 	if (!com_softintr_scheduled) {
   1226 		com_softintr_scheduled = 1;
   1227 		callout_reset(&comsoft_callout, 1, comsoft, NULL);
   1228 	}
   1229 #endif
   1230 #endif
   1231 }
   1232 
   1233 void
   1234 com_break(struct com_softc *sc, int onoff)
   1235 {
   1236 
   1237 	if (onoff)
   1238 		SET(sc->sc_lcr, LCR_SBREAK);
   1239 	else
   1240 		CLR(sc->sc_lcr, LCR_SBREAK);
   1241 
   1242 	if (!sc->sc_heldchange) {
   1243 		if (sc->sc_tx_busy) {
   1244 			sc->sc_heldtbc = sc->sc_tbc;
   1245 			sc->sc_tbc = 0;
   1246 			sc->sc_heldchange = 1;
   1247 		} else
   1248 			com_loadchannelregs(sc);
   1249 	}
   1250 }
   1251 
   1252 void
   1253 com_modem(struct com_softc *sc, int onoff)
   1254 {
   1255 
   1256 	if (sc->sc_mcr_dtr == 0)
   1257 		return;
   1258 
   1259 	if (onoff)
   1260 		SET(sc->sc_mcr, sc->sc_mcr_dtr);
   1261 	else
   1262 		CLR(sc->sc_mcr, sc->sc_mcr_dtr);
   1263 
   1264 	if (!sc->sc_heldchange) {
   1265 		if (sc->sc_tx_busy) {
   1266 			sc->sc_heldtbc = sc->sc_tbc;
   1267 			sc->sc_tbc = 0;
   1268 			sc->sc_heldchange = 1;
   1269 		} else
   1270 			com_loadchannelregs(sc);
   1271 	}
   1272 }
   1273 
   1274 void
   1275 tiocm_to_com(struct com_softc *sc, u_long how, int ttybits)
   1276 {
   1277 	u_char combits;
   1278 
   1279 	combits = 0;
   1280 	if (ISSET(ttybits, TIOCM_DTR))
   1281 		SET(combits, MCR_DTR);
   1282 	if (ISSET(ttybits, TIOCM_RTS))
   1283 		SET(combits, MCR_RTS);
   1284 
   1285 	switch (how) {
   1286 	case TIOCMBIC:
   1287 		CLR(sc->sc_mcr, combits);
   1288 		break;
   1289 
   1290 	case TIOCMBIS:
   1291 		SET(sc->sc_mcr, combits);
   1292 		break;
   1293 
   1294 	case TIOCMSET:
   1295 		CLR(sc->sc_mcr, MCR_DTR | MCR_RTS);
   1296 		SET(sc->sc_mcr, combits);
   1297 		break;
   1298 	}
   1299 
   1300 	if (!sc->sc_heldchange) {
   1301 		if (sc->sc_tx_busy) {
   1302 			sc->sc_heldtbc = sc->sc_tbc;
   1303 			sc->sc_tbc = 0;
   1304 			sc->sc_heldchange = 1;
   1305 		} else
   1306 			com_loadchannelregs(sc);
   1307 	}
   1308 }
   1309 
   1310 int
   1311 com_to_tiocm(struct com_softc *sc)
   1312 {
   1313 	u_char combits;
   1314 	int ttybits = 0;
   1315 
   1316 	combits = sc->sc_mcr;
   1317 	if (ISSET(combits, MCR_DTR))
   1318 		SET(ttybits, TIOCM_DTR);
   1319 	if (ISSET(combits, MCR_RTS))
   1320 		SET(ttybits, TIOCM_RTS);
   1321 
   1322 	combits = sc->sc_msr;
   1323 	if (ISSET(combits, MSR_DCD))
   1324 		SET(ttybits, TIOCM_CD);
   1325 	if (ISSET(combits, MSR_CTS))
   1326 		SET(ttybits, TIOCM_CTS);
   1327 	if (ISSET(combits, MSR_DSR))
   1328 		SET(ttybits, TIOCM_DSR);
   1329 	if (ISSET(combits, MSR_RI | MSR_TERI))
   1330 		SET(ttybits, TIOCM_RI);
   1331 
   1332 #ifdef COM_PXA2X0
   1333 	if (sc->sc_type == COM_TYPE_PXA2x0) {
   1334 		if ((sc->sc_ier & 0x0f) != 0)
   1335 			SET(ttybits, TIOCM_LE);
   1336 	} else
   1337 #endif
   1338 	if ((sc->sc_ier & 0xbf) != 0)
   1339 		SET(ttybits, TIOCM_LE);
   1340 
   1341 	return (ttybits);
   1342 }
   1343 
   1344 static u_char
   1345 cflag2lcr(tcflag_t cflag)
   1346 {
   1347 	u_char lcr = 0;
   1348 
   1349 	switch (ISSET(cflag, CSIZE)) {
   1350 	case CS5:
   1351 		SET(lcr, LCR_5BITS);
   1352 		break;
   1353 	case CS6:
   1354 		SET(lcr, LCR_6BITS);
   1355 		break;
   1356 	case CS7:
   1357 		SET(lcr, LCR_7BITS);
   1358 		break;
   1359 	case CS8:
   1360 		SET(lcr, LCR_8BITS);
   1361 		break;
   1362 	}
   1363 	if (ISSET(cflag, PARENB)) {
   1364 		SET(lcr, LCR_PENAB);
   1365 		if (!ISSET(cflag, PARODD))
   1366 			SET(lcr, LCR_PEVEN);
   1367 	}
   1368 	if (ISSET(cflag, CSTOPB))
   1369 		SET(lcr, LCR_STOPB);
   1370 
   1371 	return (lcr);
   1372 }
   1373 
   1374 int
   1375 comparam(struct tty *tp, struct termios *t)
   1376 {
   1377 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(tp->t_dev));
   1378 	int ospeed;
   1379 	u_char lcr;
   1380 	int s;
   1381 
   1382 	if (COM_ISALIVE(sc) == 0)
   1383 		return (EIO);
   1384 
   1385 #ifdef COM_HAYESP
   1386 	if (sc->sc_type == COM_TYPE_HAYESP) {
   1387 		int prescaler, speed;
   1388 
   1389 		/*
   1390 		 * Calculate UART clock prescaler.  It should be in
   1391 		 * range of 0 .. 3.
   1392 		 */
   1393 		for (prescaler = 0, speed = t->c_ospeed; prescaler < 4;
   1394 		    prescaler++, speed /= 2)
   1395 			if ((ospeed = comspeed(speed, sc->sc_frequency,
   1396 					       sc->sc_type)) > 0)
   1397 				break;
   1398 
   1399 		if (prescaler == 4)
   1400 			return (EINVAL);
   1401 		sc->sc_prescaler = prescaler;
   1402 	} else
   1403 #endif
   1404 	ospeed = comspeed(t->c_ospeed, sc->sc_frequency, sc->sc_type);
   1405 
   1406 	/* Check requested parameters. */
   1407 	if (ospeed < 0)
   1408 		return (EINVAL);
   1409 	if (t->c_ispeed && t->c_ispeed != t->c_ospeed)
   1410 		return (EINVAL);
   1411 
   1412 	/*
   1413 	 * For the console, always force CLOCAL and !HUPCL, so that the port
   1414 	 * is always active.
   1415 	 */
   1416 	if (ISSET(sc->sc_swflags, TIOCFLAG_SOFTCAR) ||
   1417 	    ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
   1418 		SET(t->c_cflag, CLOCAL);
   1419 		CLR(t->c_cflag, HUPCL);
   1420 	}
   1421 
   1422 	/*
   1423 	 * If there were no changes, don't do anything.  This avoids dropping
   1424 	 * input and improves performance when all we did was frob things like
   1425 	 * VMIN and VTIME.
   1426 	 */
   1427 	if (tp->t_ospeed == t->c_ospeed &&
   1428 	    tp->t_cflag == t->c_cflag)
   1429 		return (0);
   1430 
   1431 	lcr = ISSET(sc->sc_lcr, LCR_SBREAK) | cflag2lcr(t->c_cflag);
   1432 
   1433 	s = splserial();
   1434 	COM_LOCK(sc);
   1435 
   1436 	sc->sc_lcr = lcr;
   1437 
   1438 	/*
   1439 	 * If we're not in a mode that assumes a connection is present, then
   1440 	 * ignore carrier changes.
   1441 	 */
   1442 	if (ISSET(t->c_cflag, CLOCAL | MDMBUF))
   1443 		sc->sc_msr_dcd = 0;
   1444 	else
   1445 		sc->sc_msr_dcd = MSR_DCD;
   1446 	/*
   1447 	 * Set the flow control pins depending on the current flow control
   1448 	 * mode.
   1449 	 */
   1450 	if (ISSET(t->c_cflag, CRTSCTS)) {
   1451 		sc->sc_mcr_dtr = MCR_DTR;
   1452 		sc->sc_mcr_rts = MCR_RTS;
   1453 		sc->sc_msr_cts = MSR_CTS;
   1454 		sc->sc_efr = EFR_AUTORTS | EFR_AUTOCTS;
   1455 	} else if (ISSET(t->c_cflag, MDMBUF)) {
   1456 		/*
   1457 		 * For DTR/DCD flow control, make sure we don't toggle DTR for
   1458 		 * carrier detection.
   1459 		 */
   1460 		sc->sc_mcr_dtr = 0;
   1461 		sc->sc_mcr_rts = MCR_DTR;
   1462 		sc->sc_msr_cts = MSR_DCD;
   1463 		sc->sc_efr = 0;
   1464 	} else {
   1465 		/*
   1466 		 * If no flow control, then always set RTS.  This will make
   1467 		 * the other side happy if it mistakenly thinks we're doing
   1468 		 * RTS/CTS flow control.
   1469 		 */
   1470 		sc->sc_mcr_dtr = MCR_DTR | MCR_RTS;
   1471 		sc->sc_mcr_rts = 0;
   1472 		sc->sc_msr_cts = 0;
   1473 		sc->sc_efr = 0;
   1474 		if (ISSET(sc->sc_mcr, MCR_DTR))
   1475 			SET(sc->sc_mcr, MCR_RTS);
   1476 		else
   1477 			CLR(sc->sc_mcr, MCR_RTS);
   1478 	}
   1479 	sc->sc_msr_mask = sc->sc_msr_cts | sc->sc_msr_dcd;
   1480 
   1481 #if 0
   1482 	if (ospeed == 0)
   1483 		CLR(sc->sc_mcr, sc->sc_mcr_dtr);
   1484 	else
   1485 		SET(sc->sc_mcr, sc->sc_mcr_dtr);
   1486 #endif
   1487 
   1488 	sc->sc_dlbl = ospeed;
   1489 	sc->sc_dlbh = ospeed >> 8;
   1490 
   1491 	/*
   1492 	 * Set the FIFO threshold based on the receive speed.
   1493 	 *
   1494 	 *  * If it's a low speed, it's probably a mouse or some other
   1495 	 *    interactive device, so set the threshold low.
   1496 	 *  * If it's a high speed, trim the trigger level down to prevent
   1497 	 *    overflows.
   1498 	 *  * Otherwise set it a bit higher.
   1499 	 */
   1500 	if (sc->sc_type == COM_TYPE_HAYESP)
   1501 		sc->sc_fifo = FIFO_DMA_MODE | FIFO_ENABLE | FIFO_TRIGGER_8;
   1502 	else if (ISSET(sc->sc_hwflags, COM_HW_FIFO))
   1503 		sc->sc_fifo = FIFO_ENABLE |
   1504 		    (t->c_ospeed <= 1200 ? FIFO_TRIGGER_1 :
   1505 		     t->c_ospeed <= 38400 ? FIFO_TRIGGER_8 : FIFO_TRIGGER_4);
   1506 	else
   1507 		sc->sc_fifo = 0;
   1508 
   1509 	/* And copy to tty. */
   1510 	tp->t_ispeed = 0;
   1511 	tp->t_ospeed = t->c_ospeed;
   1512 	tp->t_cflag = t->c_cflag;
   1513 
   1514 	if (!sc->sc_heldchange) {
   1515 		if (sc->sc_tx_busy) {
   1516 			sc->sc_heldtbc = sc->sc_tbc;
   1517 			sc->sc_tbc = 0;
   1518 			sc->sc_heldchange = 1;
   1519 		} else
   1520 			com_loadchannelregs(sc);
   1521 	}
   1522 
   1523 	if (!ISSET(t->c_cflag, CHWFLOW)) {
   1524 		/* Disable the high water mark. */
   1525 		sc->sc_r_hiwat = 0;
   1526 		sc->sc_r_lowat = 0;
   1527 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
   1528 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
   1529 			com_schedrx(sc);
   1530 		}
   1531 		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED)) {
   1532 			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED);
   1533 			com_hwiflow(sc);
   1534 		}
   1535 	} else {
   1536 		sc->sc_r_hiwat = com_rbuf_hiwat;
   1537 		sc->sc_r_lowat = com_rbuf_lowat;
   1538 	}
   1539 
   1540 	COM_UNLOCK(sc);
   1541 	splx(s);
   1542 
   1543 	/*
   1544 	 * Update the tty layer's idea of the carrier bit, in case we changed
   1545 	 * CLOCAL or MDMBUF.  We don't hang up here; we only do that by
   1546 	 * explicit request.
   1547 	 */
   1548 	(void) (*tp->t_linesw->l_modem)(tp, ISSET(sc->sc_msr, MSR_DCD));
   1549 
   1550 #ifdef COM_DEBUG
   1551 	if (com_debug)
   1552 		comstatus(sc, "comparam ");
   1553 #endif
   1554 
   1555 	if (!ISSET(t->c_cflag, CHWFLOW)) {
   1556 		if (sc->sc_tx_stopped) {
   1557 			sc->sc_tx_stopped = 0;
   1558 			comstart(tp);
   1559 		}
   1560 	}
   1561 
   1562 	return (0);
   1563 }
   1564 
   1565 void
   1566 com_iflush(struct com_softc *sc)
   1567 {
   1568 	bus_space_tag_t iot = sc->sc_iot;
   1569 	bus_space_handle_t ioh = sc->sc_ioh;
   1570 #ifdef DIAGNOSTIC
   1571 	int reg;
   1572 #endif
   1573 	int timo;
   1574 
   1575 #ifdef DIAGNOSTIC
   1576 	reg = 0xffff;
   1577 #endif
   1578 	timo = 50000;
   1579 	/* flush any pending I/O */
   1580 	while (ISSET(bus_space_read_1(iot, ioh, com_lsr), LSR_RXRDY)
   1581 	    && --timo)
   1582 #ifdef DIAGNOSTIC
   1583 		reg =
   1584 #else
   1585 		    (void)
   1586 #endif
   1587 		    bus_space_read_1(iot, ioh, com_data);
   1588 #ifdef DIAGNOSTIC
   1589 	if (!timo)
   1590 		printf("%s: com_iflush timeout %02x\n", sc->sc_dev.dv_xname,
   1591 		       reg);
   1592 #endif
   1593 }
   1594 
   1595 void
   1596 com_loadchannelregs(struct com_softc *sc)
   1597 {
   1598 	bus_space_tag_t iot = sc->sc_iot;
   1599 	bus_space_handle_t ioh = sc->sc_ioh;
   1600 
   1601 	/* XXXXX necessary? */
   1602 	com_iflush(sc);
   1603 
   1604 #ifdef COM_PXA2X0
   1605 	if (sc->sc_type == COM_TYPE_PXA2x0)
   1606 		bus_space_write_1(iot, ioh, com_ier, IER_EUART);
   1607 	else
   1608 #endif
   1609 		bus_space_write_1(iot, ioh, com_ier, 0);
   1610 
   1611 	if (ISSET(sc->sc_hwflags, COM_HW_FLOW)) {
   1612 		bus_space_write_1(iot, ioh, com_lcr, LCR_EERS);
   1613 		bus_space_write_1(iot, ioh, com_efr, sc->sc_efr);
   1614 	}
   1615 	bus_space_write_1(iot, ioh, com_lcr, sc->sc_lcr | LCR_DLAB);
   1616 	bus_space_write_1(iot, ioh, com_dlbl, sc->sc_dlbl);
   1617 	bus_space_write_1(iot, ioh, com_dlbh, sc->sc_dlbh);
   1618 	bus_space_write_1(iot, ioh, com_lcr, sc->sc_lcr);
   1619 	bus_space_write_1(iot, ioh, com_mcr, sc->sc_mcr_active = sc->sc_mcr);
   1620 	bus_space_write_1(iot, ioh, com_fifo, sc->sc_fifo);
   1621 #ifdef COM_HAYESP
   1622 	if (sc->sc_type == COM_TYPE_HAYESP) {
   1623 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD1,
   1624 		    HAYESP_SETPRESCALER);
   1625 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
   1626 		    sc->sc_prescaler);
   1627 	}
   1628 #endif
   1629 
   1630 	bus_space_write_1(iot, ioh, com_ier, sc->sc_ier);
   1631 }
   1632 
   1633 int
   1634 comhwiflow(struct tty *tp, int block)
   1635 {
   1636 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(tp->t_dev));
   1637 	int s;
   1638 
   1639 	if (COM_ISALIVE(sc) == 0)
   1640 		return (0);
   1641 
   1642 	if (sc->sc_mcr_rts == 0)
   1643 		return (0);
   1644 
   1645 	s = splserial();
   1646 	COM_LOCK(sc);
   1647 
   1648 	if (block) {
   1649 		if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
   1650 			SET(sc->sc_rx_flags, RX_TTY_BLOCKED);
   1651 			com_hwiflow(sc);
   1652 		}
   1653 	} else {
   1654 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
   1655 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
   1656 			com_schedrx(sc);
   1657 		}
   1658 		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
   1659 			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED);
   1660 			com_hwiflow(sc);
   1661 		}
   1662 	}
   1663 
   1664 	COM_UNLOCK(sc);
   1665 	splx(s);
   1666 	return (1);
   1667 }
   1668 
   1669 /*
   1670  * (un)block input via hw flowcontrol
   1671  */
   1672 void
   1673 com_hwiflow(struct com_softc *sc)
   1674 {
   1675 	bus_space_tag_t iot = sc->sc_iot;
   1676 	bus_space_handle_t ioh = sc->sc_ioh;
   1677 
   1678 	if (sc->sc_mcr_rts == 0)
   1679 		return;
   1680 
   1681 	if (ISSET(sc->sc_rx_flags, RX_ANY_BLOCK)) {
   1682 		CLR(sc->sc_mcr, sc->sc_mcr_rts);
   1683 		CLR(sc->sc_mcr_active, sc->sc_mcr_rts);
   1684 	} else {
   1685 		SET(sc->sc_mcr, sc->sc_mcr_rts);
   1686 		SET(sc->sc_mcr_active, sc->sc_mcr_rts);
   1687 	}
   1688 	bus_space_write_1(iot, ioh, com_mcr, sc->sc_mcr_active);
   1689 }
   1690 
   1691 
   1692 void
   1693 comstart(struct tty *tp)
   1694 {
   1695 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(tp->t_dev));
   1696 	bus_space_tag_t iot = sc->sc_iot;
   1697 	bus_space_handle_t ioh = sc->sc_ioh;
   1698 	int s;
   1699 
   1700 	if (COM_ISALIVE(sc) == 0)
   1701 		return;
   1702 
   1703 	s = spltty();
   1704 	if (ISSET(tp->t_state, TS_BUSY | TS_TIMEOUT | TS_TTSTOP))
   1705 		goto out;
   1706 	if (sc->sc_tx_stopped)
   1707 		goto out;
   1708 
   1709 	if (tp->t_outq.c_cc <= tp->t_lowat) {
   1710 		if (ISSET(tp->t_state, TS_ASLEEP)) {
   1711 			CLR(tp->t_state, TS_ASLEEP);
   1712 			wakeup(&tp->t_outq);
   1713 		}
   1714 		selwakeup(&tp->t_wsel);
   1715 		if (tp->t_outq.c_cc == 0)
   1716 			goto out;
   1717 	}
   1718 
   1719 	/* Grab the first contiguous region of buffer space. */
   1720 	{
   1721 		u_char *tba;
   1722 		int tbc;
   1723 
   1724 		tba = tp->t_outq.c_cf;
   1725 		tbc = ndqb(&tp->t_outq, 0);
   1726 
   1727 		(void)splserial();
   1728 		COM_LOCK(sc);
   1729 
   1730 		sc->sc_tba = tba;
   1731 		sc->sc_tbc = tbc;
   1732 	}
   1733 
   1734 	SET(tp->t_state, TS_BUSY);
   1735 	sc->sc_tx_busy = 1;
   1736 
   1737 	/* Enable transmit completion interrupts if necessary. */
   1738 	if (!ISSET(sc->sc_ier, IER_ETXRDY)) {
   1739 		SET(sc->sc_ier, IER_ETXRDY);
   1740 		bus_space_write_1(iot, ioh, com_ier, sc->sc_ier);
   1741 	}
   1742 
   1743 	/* Output the first chunk of the contiguous buffer. */
   1744 	if (!ISSET(sc->sc_hwflags, COM_HW_NO_TXPRELOAD)) {
   1745 		u_int n;
   1746 
   1747 		n = sc->sc_tbc;
   1748 		if (n > sc->sc_fifolen)
   1749 			n = sc->sc_fifolen;
   1750 		bus_space_write_multi_1(iot, ioh, com_data, sc->sc_tba, n);
   1751 		sc->sc_tbc -= n;
   1752 		sc->sc_tba += n;
   1753 	}
   1754 	COM_UNLOCK(sc);
   1755 out:
   1756 	splx(s);
   1757 	return;
   1758 }
   1759 
   1760 /*
   1761  * Stop output on a line.
   1762  */
   1763 void
   1764 comstop(struct tty *tp, int flag)
   1765 {
   1766 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(tp->t_dev));
   1767 	int s;
   1768 
   1769 	s = splserial();
   1770 	COM_LOCK(sc);
   1771 	if (ISSET(tp->t_state, TS_BUSY)) {
   1772 		/* Stop transmitting at the next chunk. */
   1773 		sc->sc_tbc = 0;
   1774 		sc->sc_heldtbc = 0;
   1775 		if (!ISSET(tp->t_state, TS_TTSTOP))
   1776 			SET(tp->t_state, TS_FLUSH);
   1777 	}
   1778 	COM_UNLOCK(sc);
   1779 	splx(s);
   1780 }
   1781 
   1782 void
   1783 comdiag(void *arg)
   1784 {
   1785 	struct com_softc *sc = arg;
   1786 	int overflows, floods;
   1787 	int s;
   1788 
   1789 	s = splserial();
   1790 	COM_LOCK(sc);
   1791 	overflows = sc->sc_overflows;
   1792 	sc->sc_overflows = 0;
   1793 	floods = sc->sc_floods;
   1794 	sc->sc_floods = 0;
   1795 	sc->sc_errors = 0;
   1796 	COM_UNLOCK(sc);
   1797 	splx(s);
   1798 
   1799 	log(LOG_WARNING, "%s: %d silo overflow%s, %d ibuf flood%s\n",
   1800 	    sc->sc_dev.dv_xname,
   1801 	    overflows, overflows == 1 ? "" : "s",
   1802 	    floods, floods == 1 ? "" : "s");
   1803 }
   1804 
   1805 integrate void
   1806 com_rxsoft(struct com_softc *sc, struct tty *tp)
   1807 {
   1808 	int (*rint)(int, struct tty *) = tp->t_linesw->l_rint;
   1809 	u_char *get, *end;
   1810 	u_int cc, scc;
   1811 	u_char lsr;
   1812 	int code;
   1813 	int s;
   1814 
   1815 	end = sc->sc_ebuf;
   1816 	get = sc->sc_rbget;
   1817 	scc = cc = com_rbuf_size - sc->sc_rbavail;
   1818 
   1819 	if (cc == com_rbuf_size) {
   1820 		sc->sc_floods++;
   1821 		if (sc->sc_errors++ == 0)
   1822 			callout_reset(&sc->sc_diag_callout, 60 * hz,
   1823 			    comdiag, sc);
   1824 	}
   1825 
   1826 	/* If not yet open, drop the entire buffer content here */
   1827 	if (!ISSET(tp->t_state, TS_ISOPEN)) {
   1828 		get += cc << 1;
   1829 		if (get >= end)
   1830 			get -= com_rbuf_size << 1;
   1831 		cc = 0;
   1832 	}
   1833 	while (cc) {
   1834 		code = get[0];
   1835 		lsr = get[1];
   1836 		if (ISSET(lsr, LSR_OE | LSR_BI | LSR_FE | LSR_PE)) {
   1837 			if (ISSET(lsr, LSR_OE)) {
   1838 				sc->sc_overflows++;
   1839 				if (sc->sc_errors++ == 0)
   1840 					callout_reset(&sc->sc_diag_callout,
   1841 					    60 * hz, comdiag, sc);
   1842 			}
   1843 			if (ISSET(lsr, LSR_BI | LSR_FE))
   1844 				SET(code, TTY_FE);
   1845 			if (ISSET(lsr, LSR_PE))
   1846 				SET(code, TTY_PE);
   1847 		}
   1848 		if ((*rint)(code, tp) == -1) {
   1849 			/*
   1850 			 * The line discipline's buffer is out of space.
   1851 			 */
   1852 			if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
   1853 				/*
   1854 				 * We're either not using flow control, or the
   1855 				 * line discipline didn't tell us to block for
   1856 				 * some reason.  Either way, we have no way to
   1857 				 * know when there's more space available, so
   1858 				 * just drop the rest of the data.
   1859 				 */
   1860 				get += cc << 1;
   1861 				if (get >= end)
   1862 					get -= com_rbuf_size << 1;
   1863 				cc = 0;
   1864 			} else {
   1865 				/*
   1866 				 * Don't schedule any more receive processing
   1867 				 * until the line discipline tells us there's
   1868 				 * space available (through comhwiflow()).
   1869 				 * Leave the rest of the data in the input
   1870 				 * buffer.
   1871 				 */
   1872 				SET(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
   1873 			}
   1874 			break;
   1875 		}
   1876 		get += 2;
   1877 		if (get >= end)
   1878 			get = sc->sc_rbuf;
   1879 		cc--;
   1880 	}
   1881 
   1882 	if (cc != scc) {
   1883 		sc->sc_rbget = get;
   1884 		s = splserial();
   1885 		COM_LOCK(sc);
   1886 
   1887 		cc = sc->sc_rbavail += scc - cc;
   1888 		/* Buffers should be ok again, release possible block. */
   1889 		if (cc >= sc->sc_r_lowat) {
   1890 			if (ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
   1891 				CLR(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
   1892 				SET(sc->sc_ier, IER_ERXRDY);
   1893 #ifdef COM_PXA2X0
   1894 				if (sc->sc_type == COM_TYPE_PXA2x0)
   1895 					SET(sc->sc_ier, IER_ERXTOUT);
   1896 #endif
   1897 				bus_space_write_1(sc->sc_iot, sc->sc_ioh, com_ier, sc->sc_ier);
   1898 			}
   1899 			if (ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED)) {
   1900 				CLR(sc->sc_rx_flags, RX_IBUF_BLOCKED);
   1901 				com_hwiflow(sc);
   1902 			}
   1903 		}
   1904 		COM_UNLOCK(sc);
   1905 		splx(s);
   1906 	}
   1907 }
   1908 
   1909 integrate void
   1910 com_txsoft(struct com_softc *sc, struct tty *tp)
   1911 {
   1912 
   1913 	CLR(tp->t_state, TS_BUSY);
   1914 	if (ISSET(tp->t_state, TS_FLUSH))
   1915 		CLR(tp->t_state, TS_FLUSH);
   1916 	else
   1917 		ndflush(&tp->t_outq, (int)(sc->sc_tba - tp->t_outq.c_cf));
   1918 	(*tp->t_linesw->l_start)(tp);
   1919 }
   1920 
   1921 integrate void
   1922 com_stsoft(struct com_softc *sc, struct tty *tp)
   1923 {
   1924 	u_char msr, delta;
   1925 	int s;
   1926 
   1927 	s = splserial();
   1928 	COM_LOCK(sc);
   1929 	msr = sc->sc_msr;
   1930 	delta = sc->sc_msr_delta;
   1931 	sc->sc_msr_delta = 0;
   1932 	COM_UNLOCK(sc);
   1933 	splx(s);
   1934 
   1935 	if (ISSET(delta, sc->sc_msr_dcd)) {
   1936 		/*
   1937 		 * Inform the tty layer that carrier detect changed.
   1938 		 */
   1939 		(void) (*tp->t_linesw->l_modem)(tp, ISSET(msr, MSR_DCD));
   1940 	}
   1941 
   1942 	if (ISSET(delta, sc->sc_msr_cts)) {
   1943 		/* Block or unblock output according to flow control. */
   1944 		if (ISSET(msr, sc->sc_msr_cts)) {
   1945 			sc->sc_tx_stopped = 0;
   1946 			(*tp->t_linesw->l_start)(tp);
   1947 		} else {
   1948 			sc->sc_tx_stopped = 1;
   1949 		}
   1950 	}
   1951 
   1952 #ifdef COM_DEBUG
   1953 	if (com_debug)
   1954 		comstatus(sc, "com_stsoft");
   1955 #endif
   1956 }
   1957 
   1958 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
   1959 void
   1960 comsoft(void *arg)
   1961 {
   1962 	struct com_softc *sc = arg;
   1963 	struct tty *tp;
   1964 
   1965 	if (COM_ISALIVE(sc) == 0)
   1966 		return;
   1967 
   1968 	{
   1969 #else
   1970 void
   1971 #ifndef __NO_SOFT_SERIAL_INTERRUPT
   1972 comsoft(void)
   1973 #else
   1974 comsoft(void *arg)
   1975 #endif
   1976 {
   1977 	struct com_softc	*sc;
   1978 	struct tty	*tp;
   1979 	int	unit;
   1980 #ifdef __NO_SOFT_SERIAL_INTERRUPT
   1981 	int s;
   1982 
   1983 	s = splsoftserial();
   1984 	com_softintr_scheduled = 0;
   1985 #endif
   1986 
   1987 	for (unit = 0; unit < com_cd.cd_ndevs; unit++) {
   1988 		sc = device_lookup(&com_cd, unit);
   1989 		if (sc == NULL || !ISSET(sc->sc_hwflags, COM_HW_DEV_OK))
   1990 			continue;
   1991 
   1992 		if (COM_ISALIVE(sc) == 0)
   1993 			continue;
   1994 
   1995 		tp = sc->sc_tty;
   1996 		if (tp == NULL)
   1997 			continue;
   1998 		if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0)
   1999 			continue;
   2000 #endif
   2001 		tp = sc->sc_tty;
   2002 
   2003 		if (sc->sc_rx_ready) {
   2004 			sc->sc_rx_ready = 0;
   2005 			com_rxsoft(sc, tp);
   2006 		}
   2007 
   2008 		if (sc->sc_st_check) {
   2009 			sc->sc_st_check = 0;
   2010 			com_stsoft(sc, tp);
   2011 		}
   2012 
   2013 		if (sc->sc_tx_done) {
   2014 			sc->sc_tx_done = 0;
   2015 			com_txsoft(sc, tp);
   2016 		}
   2017 	}
   2018 
   2019 #ifndef __HAVE_GENERIC_SOFT_INTERRUPTS
   2020 #ifdef __NO_SOFT_SERIAL_INTERRUPT
   2021 	splx(s);
   2022 #endif
   2023 #endif
   2024 }
   2025 
   2026 #ifdef __ALIGN_BRACKET_LEVEL_FOR_CTAGS
   2027 	/* there has got to be a better way to do comsoft() */
   2028 }}
   2029 #endif
   2030 
   2031 int
   2032 comintr(void *arg)
   2033 {
   2034 	struct com_softc *sc = arg;
   2035 	bus_space_tag_t iot = sc->sc_iot;
   2036 	bus_space_handle_t ioh = sc->sc_ioh;
   2037 	u_char *put, *end;
   2038 	u_int cc;
   2039 	u_char lsr, iir;
   2040 
   2041 	if (COM_ISALIVE(sc) == 0)
   2042 		return (0);
   2043 
   2044 	COM_LOCK(sc);
   2045 	iir = bus_space_read_1(iot, ioh, com_iir);
   2046 	if (ISSET(iir, IIR_NOPEND)) {
   2047 		COM_UNLOCK(sc);
   2048 		return (0);
   2049 	}
   2050 
   2051 	end = sc->sc_ebuf;
   2052 	put = sc->sc_rbput;
   2053 	cc = sc->sc_rbavail;
   2054 
   2055 again:	do {
   2056 		u_char	msr, delta;
   2057 
   2058 		lsr = bus_space_read_1(iot, ioh, com_lsr);
   2059 		if (ISSET(lsr, LSR_BI)) {
   2060 			int cn_trapped = 0;
   2061 
   2062 			cn_check_magic(sc->sc_tty->t_dev,
   2063 				       CNC_BREAK, com_cnm_state);
   2064 			if (cn_trapped)
   2065 				continue;
   2066 #if defined(KGDB) && !defined(DDB)
   2067 			if (ISSET(sc->sc_hwflags, COM_HW_KGDB)) {
   2068 				kgdb_connect(1);
   2069 				continue;
   2070 			}
   2071 #endif
   2072 		}
   2073 
   2074 		if (ISSET(lsr, LSR_RCV_MASK) &&
   2075 		    !ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
   2076 			while (cc > 0) {
   2077 				int cn_trapped = 0;
   2078 				put[0] = bus_space_read_1(iot, ioh, com_data);
   2079 				put[1] = lsr;
   2080 				cn_check_magic(sc->sc_tty->t_dev,
   2081 					       put[0], com_cnm_state);
   2082 				if (cn_trapped) {
   2083 					lsr = bus_space_read_1(iot, ioh, com_lsr);
   2084 					if (!ISSET(lsr, LSR_RCV_MASK))
   2085 						break;
   2086 
   2087 					continue;
   2088 				}
   2089 				put += 2;
   2090 				if (put >= end)
   2091 					put = sc->sc_rbuf;
   2092 				cc--;
   2093 
   2094 				lsr = bus_space_read_1(iot, ioh, com_lsr);
   2095 				if (!ISSET(lsr, LSR_RCV_MASK))
   2096 					break;
   2097 			}
   2098 
   2099 			/*
   2100 			 * Current string of incoming characters ended because
   2101 			 * no more data was available or we ran out of space.
   2102 			 * Schedule a receive event if any data was received.
   2103 			 * If we're out of space, turn off receive interrupts.
   2104 			 */
   2105 			sc->sc_rbput = put;
   2106 			sc->sc_rbavail = cc;
   2107 			if (!ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED))
   2108 				sc->sc_rx_ready = 1;
   2109 
   2110 			/*
   2111 			 * See if we are in danger of overflowing a buffer. If
   2112 			 * so, use hardware flow control to ease the pressure.
   2113 			 */
   2114 			if (!ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED) &&
   2115 			    cc < sc->sc_r_hiwat) {
   2116 				SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
   2117 				com_hwiflow(sc);
   2118 			}
   2119 
   2120 			/*
   2121 			 * If we're out of space, disable receive interrupts
   2122 			 * until the queue has drained a bit.
   2123 			 */
   2124 			if (!cc) {
   2125 				SET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
   2126 				CLR(sc->sc_ier, IER_ERXRDY);
   2127 #ifdef COM_PXA2X0
   2128 				if (sc->sc_type == COM_TYPE_PXA2x0)
   2129 					CLR(sc->sc_ier, IER_ERXTOUT);
   2130 #endif
   2131 				bus_space_write_1(iot, ioh, com_ier, sc->sc_ier);
   2132 			}
   2133 		} else {
   2134 			if ((iir & IIR_IMASK) == IIR_RXRDY) {
   2135 #ifdef COM_PXA2X0
   2136 				if (sc->sc_type == COM_TYPE_PXA2x0)
   2137 					bus_space_write_1(iot, ioh, com_ier,
   2138 					    IER_EUART);
   2139 				else
   2140 #endif
   2141 					bus_space_write_1(iot, ioh, com_ier, 0);
   2142 				delay(10);
   2143 				bus_space_write_1(iot, ioh, com_ier,sc->sc_ier);
   2144 				continue;
   2145 			}
   2146 		}
   2147 
   2148 		msr = bus_space_read_1(iot, ioh, com_msr);
   2149 		delta = msr ^ sc->sc_msr;
   2150 		sc->sc_msr = msr;
   2151 		/*
   2152 		 * Pulse-per-second (PSS) signals on edge of DCD?
   2153 		 * Process these even if line discipline is ignoring DCD.
   2154 		 */
   2155 		if (delta & sc->sc_ppsmask) {
   2156 			struct timeval tv;
   2157 		    	if ((msr & sc->sc_ppsmask) == sc->sc_ppsassert) {
   2158 				/* XXX nanotime() */
   2159 				microtime(&tv);
   2160 				TIMEVAL_TO_TIMESPEC(&tv,
   2161 				    &sc->ppsinfo.assert_timestamp);
   2162 				if (sc->ppsparam.mode & PPS_OFFSETASSERT) {
   2163 					timespecadd(&sc->ppsinfo.assert_timestamp,
   2164 					    &sc->ppsparam.assert_offset,
   2165 						    &sc->ppsinfo.assert_timestamp);
   2166 				}
   2167 
   2168 #ifdef PPS_SYNC
   2169 				if (sc->ppsparam.mode & PPS_HARDPPSONASSERT)
   2170 					hardpps(&tv, tv.tv_usec);
   2171 #endif
   2172 				sc->ppsinfo.assert_sequence++;
   2173 				sc->ppsinfo.current_mode = sc->ppsparam.mode;
   2174 
   2175 			} else if ((msr & sc->sc_ppsmask) == sc->sc_ppsclear) {
   2176 				/* XXX nanotime() */
   2177 				microtime(&tv);
   2178 				TIMEVAL_TO_TIMESPEC(&tv,
   2179 				    &sc->ppsinfo.clear_timestamp);
   2180 				if (sc->ppsparam.mode & PPS_OFFSETCLEAR) {
   2181 					timespecadd(&sc->ppsinfo.clear_timestamp,
   2182 					    &sc->ppsparam.clear_offset,
   2183 					    &sc->ppsinfo.clear_timestamp);
   2184 				}
   2185 
   2186 #ifdef PPS_SYNC
   2187 				if (sc->ppsparam.mode & PPS_HARDPPSONCLEAR)
   2188 					hardpps(&tv, tv.tv_usec);
   2189 #endif
   2190 				sc->ppsinfo.clear_sequence++;
   2191 				sc->ppsinfo.current_mode = sc->ppsparam.mode;
   2192 			}
   2193 		}
   2194 
   2195 		/*
   2196 		 * Process normal status changes
   2197 		 */
   2198 		if (ISSET(delta, sc->sc_msr_mask)) {
   2199 			SET(sc->sc_msr_delta, delta);
   2200 
   2201 			/*
   2202 			 * Stop output immediately if we lose the output
   2203 			 * flow control signal or carrier detect.
   2204 			 */
   2205 			if (ISSET(~msr, sc->sc_msr_mask)) {
   2206 				sc->sc_tbc = 0;
   2207 				sc->sc_heldtbc = 0;
   2208 #ifdef COM_DEBUG
   2209 				if (com_debug)
   2210 					comstatus(sc, "comintr  ");
   2211 #endif
   2212 			}
   2213 
   2214 			sc->sc_st_check = 1;
   2215 		}
   2216 	} while (ISSET((iir = bus_space_read_1(iot, ioh, com_iir)), IIR_RXRDY)
   2217 	    || ((iir & IIR_IMASK) == 0));
   2218 
   2219 	/*
   2220 	 * Done handling any receive interrupts. See if data can be
   2221 	 * transmitted as well. Schedule tx done event if no data left
   2222 	 * and tty was marked busy.
   2223 	 */
   2224 	if (ISSET(lsr, LSR_TXRDY)) {
   2225 		/*
   2226 		 * If we've delayed a parameter change, do it now, and restart
   2227 		 * output.
   2228 		 */
   2229 		if (sc->sc_heldchange) {
   2230 			com_loadchannelregs(sc);
   2231 			sc->sc_heldchange = 0;
   2232 			sc->sc_tbc = sc->sc_heldtbc;
   2233 			sc->sc_heldtbc = 0;
   2234 		}
   2235 
   2236 		/* Output the next chunk of the contiguous buffer, if any. */
   2237 		if (sc->sc_tbc > 0) {
   2238 			u_int n;
   2239 
   2240 			n = sc->sc_tbc;
   2241 			if (n > sc->sc_fifolen)
   2242 				n = sc->sc_fifolen;
   2243 			bus_space_write_multi_1(iot, ioh, com_data, sc->sc_tba, n);
   2244 			sc->sc_tbc -= n;
   2245 			sc->sc_tba += n;
   2246 		} else {
   2247 			/* Disable transmit completion interrupts if necessary. */
   2248 			if (ISSET(sc->sc_ier, IER_ETXRDY)) {
   2249 				CLR(sc->sc_ier, IER_ETXRDY);
   2250 				bus_space_write_1(iot, ioh, com_ier, sc->sc_ier);
   2251 			}
   2252 			if (sc->sc_tx_busy) {
   2253 				sc->sc_tx_busy = 0;
   2254 				sc->sc_tx_done = 1;
   2255 			}
   2256 		}
   2257 	}
   2258 
   2259 	if (!ISSET((iir = bus_space_read_1(iot, ioh, com_iir)), IIR_NOPEND))
   2260 		goto again;
   2261 
   2262 	COM_UNLOCK(sc);
   2263 
   2264 	/* Wake up the poller. */
   2265 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
   2266 	softintr_schedule(sc->sc_si);
   2267 #else
   2268 #ifndef __NO_SOFT_SERIAL_INTERRUPT
   2269 	setsoftserial();
   2270 #else
   2271 	if (!com_softintr_scheduled) {
   2272 		com_softintr_scheduled = 1;
   2273 		callout_reset(&comsoft_callout, 1, comsoft, NULL);
   2274 	}
   2275 #endif
   2276 #endif
   2277 
   2278 #if NRND > 0 && defined(RND_COM)
   2279 	rnd_add_uint32(&sc->rnd_source, iir | lsr);
   2280 #endif
   2281 
   2282 	return (1);
   2283 }
   2284 
   2285 /*
   2286  * The following functions are polled getc and putc routines, shared
   2287  * by the console and kgdb glue.
   2288  *
   2289  * The read-ahead code is so that you can detect pending in-band
   2290  * cn_magic in polled mode while doing output rather than having to
   2291  * wait until the kernel decides it needs input.
   2292  */
   2293 
   2294 #define MAX_READAHEAD	20
   2295 static int com_readahead[MAX_READAHEAD];
   2296 static int com_readaheadcount = 0;
   2297 
   2298 int
   2299 com_common_getc(dev_t dev, bus_space_tag_t iot, bus_space_handle_t ioh)
   2300 {
   2301 	int s = splserial();
   2302 	u_char stat, c;
   2303 
   2304 	/* got a character from reading things earlier */
   2305 	if (com_readaheadcount > 0) {
   2306 		int i;
   2307 
   2308 		c = com_readahead[0];
   2309 		for (i = 1; i < com_readaheadcount; i++) {
   2310 			com_readahead[i-1] = com_readahead[i];
   2311 		}
   2312 		com_readaheadcount--;
   2313 		splx(s);
   2314 		return (c);
   2315 	}
   2316 
   2317 	/* block until a character becomes available */
   2318 	while (!ISSET(stat = bus_space_read_1(iot, ioh, com_lsr), LSR_RXRDY))
   2319 		;
   2320 
   2321 	c = bus_space_read_1(iot, ioh, com_data);
   2322 	stat = bus_space_read_1(iot, ioh, com_iir);
   2323 	{
   2324 		int cn_trapped = 0; /* unused */
   2325 #ifdef DDB
   2326 		extern int db_active;
   2327 		if (!db_active)
   2328 #endif
   2329 			cn_check_magic(dev, c, com_cnm_state);
   2330 	}
   2331 	splx(s);
   2332 	return (c);
   2333 }
   2334 
   2335 void
   2336 com_common_putc(dev_t dev, bus_space_tag_t iot, bus_space_handle_t ioh, int c)
   2337 {
   2338 	int s = splserial();
   2339 	int cin, stat, timo;
   2340 
   2341 	if (com_readaheadcount < MAX_READAHEAD
   2342 	     && ISSET(stat = bus_space_read_1(iot, ioh, com_lsr), LSR_RXRDY)) {
   2343 		int cn_trapped = 0;
   2344 		cin = bus_space_read_1(iot, ioh, com_data);
   2345 		stat = bus_space_read_1(iot, ioh, com_iir);
   2346 		cn_check_magic(dev, cin, com_cnm_state);
   2347 		com_readahead[com_readaheadcount++] = cin;
   2348 	}
   2349 
   2350 	/* wait for any pending transmission to finish */
   2351 	timo = 150000;
   2352 	while (!ISSET(bus_space_read_1(iot, ioh, com_lsr), LSR_TXRDY) && --timo)
   2353 		continue;
   2354 
   2355 	bus_space_write_1(iot, ioh, com_data, c);
   2356 	COM_BARRIER(iot, ioh, BR | BW);
   2357 
   2358 	/* wait for this transmission to complete */
   2359 	timo = 1500000;
   2360 	while (!ISSET(bus_space_read_1(iot, ioh, com_lsr), LSR_TXRDY) && --timo)
   2361 		continue;
   2362 
   2363 	splx(s);
   2364 }
   2365 
   2366 /*
   2367  * Initialize UART for use as console or KGDB line.
   2368  */
   2369 int
   2370 cominit(bus_space_tag_t iot, bus_addr_t iobase, int rate, int frequency,
   2371     int type, tcflag_t cflag, bus_space_handle_t *iohp)
   2372 {
   2373 	bus_space_handle_t ioh;
   2374 
   2375 	if (bus_space_map(iot, iobase, COM_NPORTS, 0, &ioh))
   2376 		return (ENOMEM); /* ??? */
   2377 
   2378 	bus_space_write_1(iot, ioh, com_lcr, LCR_EERS);
   2379 	bus_space_write_1(iot, ioh, com_efr, 0);
   2380 	bus_space_write_1(iot, ioh, com_lcr, LCR_DLAB);
   2381 	rate = comspeed(rate, frequency, type);
   2382 	bus_space_write_1(iot, ioh, com_dlbl, rate);
   2383 	bus_space_write_1(iot, ioh, com_dlbh, rate >> 8);
   2384 	bus_space_write_1(iot, ioh, com_lcr, cflag2lcr(cflag));
   2385 	bus_space_write_1(iot, ioh, com_mcr, MCR_DTR | MCR_RTS);
   2386 	bus_space_write_1(iot, ioh, com_fifo,
   2387 	    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_1);
   2388 	bus_space_write_1(iot, ioh, com_ier, 0);
   2389 
   2390 	*iohp = ioh;
   2391 	return (0);
   2392 }
   2393 
   2394 /*
   2395  * Following are all routines needed for COM to act as console
   2396  */
   2397 struct consdev comcons = {
   2398 	NULL, NULL, comcngetc, comcnputc, comcnpollc, NULL, NULL, NULL,
   2399 	NODEV, CN_NORMAL
   2400 };
   2401 
   2402 
   2403 int
   2404 comcnattach(bus_space_tag_t iot, bus_addr_t iobase, int rate, int frequency,
   2405     int type, tcflag_t cflag)
   2406 {
   2407 	int res;
   2408 
   2409 	res = cominit(iot, iobase, rate, frequency, type, cflag, &comconsioh);
   2410 	if (res)
   2411 		return (res);
   2412 
   2413 	cn_tab = &comcons;
   2414 	cn_init_magic(&com_cnm_state);
   2415 	cn_set_magic("\047\001"); /* default magic is BREAK */
   2416 
   2417 	comconstag = iot;
   2418 	comconsaddr = iobase;
   2419 	comconsrate = rate;
   2420 	comconscflag = cflag;
   2421 
   2422 	return (0);
   2423 }
   2424 
   2425 int
   2426 comcngetc(dev_t dev)
   2427 {
   2428 
   2429 	return (com_common_getc(dev, comconstag, comconsioh));
   2430 }
   2431 
   2432 /*
   2433  * Console kernel output character routine.
   2434  */
   2435 void
   2436 comcnputc(dev_t dev, int c)
   2437 {
   2438 
   2439 	com_common_putc(dev, comconstag, comconsioh, c);
   2440 }
   2441 
   2442 void
   2443 comcnpollc(dev_t dev, int on)
   2444 {
   2445 
   2446 }
   2447 
   2448 #ifdef KGDB
   2449 int
   2450 com_kgdb_attach(bus_space_tag_t iot, bus_addr_t iobase, int rate,
   2451     int frequency, int type, tcflag_t cflag)
   2452 {
   2453 	int res;
   2454 
   2455 	if (iot == comconstag && iobase == comconsaddr) {
   2456 #if !defined(DDB)
   2457 		return (EBUSY); /* cannot share with console */
   2458 #else
   2459 		com_kgdb_ioh = comconsioh;
   2460 #endif
   2461 	} else {
   2462 
   2463 		res = cominit(iot, iobase, rate, frequency, type, cflag,
   2464 			      &com_kgdb_ioh);
   2465 		if (res)
   2466 			return (res);
   2467 
   2468 		/*
   2469 		 * XXXfvdl this shouldn't be needed, but the cn_magic goo
   2470 		 * expects this to be initialized
   2471 		 */
   2472 		cn_init_magic(&com_cnm_state);
   2473 		cn_set_magic("\047\001");
   2474 	}
   2475 
   2476 	kgdb_attach(com_kgdb_getc, com_kgdb_putc, NULL);
   2477 	kgdb_dev = 123; /* unneeded, only to satisfy some tests */
   2478 
   2479 	com_kgdb_iot = iot;
   2480 	com_kgdb_addr = iobase;
   2481 
   2482 	return (0);
   2483 }
   2484 
   2485 /* ARGSUSED */
   2486 int
   2487 com_kgdb_getc(void *arg)
   2488 {
   2489 
   2490 	return (com_common_getc(NODEV, com_kgdb_iot, com_kgdb_ioh));
   2491 }
   2492 
   2493 /* ARGSUSED */
   2494 void
   2495 com_kgdb_putc(void *arg, int c)
   2496 {
   2497 
   2498 	com_common_putc(NODEV, com_kgdb_iot, com_kgdb_ioh, c);
   2499 }
   2500 #endif /* KGDB */
   2501 
   2502 /* helper function to identify the com ports used by
   2503  console or KGDB (and not yet autoconf attached) */
   2504 int
   2505 com_is_console(bus_space_tag_t iot, bus_addr_t iobase, bus_space_handle_t *ioh)
   2506 {
   2507 	bus_space_handle_t help;
   2508 
   2509 	if (!comconsattached &&
   2510 	    iot == comconstag && iobase == comconsaddr)
   2511 		help = comconsioh;
   2512 #ifdef KGDB
   2513 	else if (!com_kgdb_attached &&
   2514 	    iot == com_kgdb_iot && iobase == com_kgdb_addr)
   2515 		help = com_kgdb_ioh;
   2516 #endif
   2517 	else
   2518 		return (0);
   2519 
   2520 	if (ioh)
   2521 		*ioh = help;
   2522 	return (1);
   2523 }
   2524