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com.c revision 1.225
      1 /*	$NetBSD: com.c,v 1.225 2004/04/05 22:33:08 enami 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. Neither the name of the University nor the names of its contributors
     52  *    may be used to endorse or promote products derived from this software
     53  *    without specific prior written permission.
     54  *
     55  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     56  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     57  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     58  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     59  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     60  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     61  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     62  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     63  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     64  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     65  * SUCH DAMAGE.
     66  *
     67  *	@(#)com.c	7.5 (Berkeley) 5/16/91
     68  */
     69 
     70 /*
     71  * COM driver, uses National Semiconductor NS16450/NS16550AF UART
     72  * Supports automatic hardware flow control on StarTech ST16C650A UART
     73  */
     74 
     75 #include <sys/cdefs.h>
     76 __KERNEL_RCSID(0, "$NetBSD: com.c,v 1.225 2004/04/05 22:33:08 enami Exp $");
     77 
     78 #include "opt_com.h"
     79 #include "opt_ddb.h"
     80 #include "opt_kgdb.h"
     81 #include "opt_lockdebug.h"
     82 #include "opt_multiprocessor.h"
     83 #include "opt_ntp.h"
     84 
     85 #include "rnd.h"
     86 #if NRND > 0 && defined(RND_COM)
     87 #include <sys/rnd.h>
     88 #endif
     89 
     90 /*
     91  * Override cnmagic(9) macro before including <sys/systm.h>.
     92  * We need to know if cn_check_magic triggered debugger, so set a flag.
     93  * Callers of cn_check_magic must declare int cn_trapped = 0;
     94  * XXX: this is *ugly*!
     95  */
     96 #define cn_trap()				\
     97 	do {					\
     98 		console_debugger();		\
     99 		cn_trapped = 1;			\
    100 	} while (/* CONSTCOND */ 0)
    101 
    102 #include <sys/param.h>
    103 #include <sys/systm.h>
    104 #include <sys/ioctl.h>
    105 #include <sys/select.h>
    106 #include <sys/tty.h>
    107 #include <sys/proc.h>
    108 #include <sys/user.h>
    109 #include <sys/conf.h>
    110 #include <sys/file.h>
    111 #include <sys/uio.h>
    112 #include <sys/kernel.h>
    113 #include <sys/syslog.h>
    114 #include <sys/device.h>
    115 #include <sys/malloc.h>
    116 #include <sys/timepps.h>
    117 #include <sys/vnode.h>
    118 
    119 #include <machine/intr.h>
    120 #include <machine/bus.h>
    121 
    122 #include <dev/ic/comreg.h>
    123 #include <dev/ic/comvar.h>
    124 #include <dev/ic/ns16550reg.h>
    125 #include <dev/ic/st16650reg.h>
    126 #ifdef COM_HAYESP
    127 #include <dev/ic/hayespreg.h>
    128 #endif
    129 #define	com_lcr	com_cfcr
    130 #include <dev/cons.h>
    131 
    132 #ifdef COM_HAYESP
    133 int comprobeHAYESP(bus_space_handle_t hayespioh, struct com_softc *sc);
    134 #endif
    135 
    136 static void com_enable_debugport(struct com_softc *);
    137 
    138 void	com_config(struct com_softc *);
    139 void	com_shutdown(struct com_softc *);
    140 int	comspeed(long, long, int);
    141 static	u_char	cflag2lcr(tcflag_t);
    142 int	comparam(struct tty *, struct termios *);
    143 void	comstart(struct tty *);
    144 int	comhwiflow(struct tty *, int);
    145 
    146 void	com_loadchannelregs(struct com_softc *);
    147 void	com_hwiflow(struct com_softc *);
    148 void	com_break(struct com_softc *, int);
    149 void	com_modem(struct com_softc *, int);
    150 void	tiocm_to_com(struct com_softc *, u_long, int);
    151 int	com_to_tiocm(struct com_softc *);
    152 void	com_iflush(struct com_softc *);
    153 
    154 int	com_common_getc(dev_t, bus_space_tag_t, bus_space_handle_t);
    155 void	com_common_putc(dev_t, bus_space_tag_t, bus_space_handle_t, int);
    156 
    157 int	cominit(bus_space_tag_t, bus_addr_t, int, int, int, tcflag_t,
    158 	    bus_space_handle_t *);
    159 
    160 int	comcngetc(dev_t);
    161 void	comcnputc(dev_t, int);
    162 void	comcnpollc(dev_t, int);
    163 
    164 #define	integrate	static inline
    165 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
    166 void 	comsoft(void *);
    167 #else
    168 #ifndef __NO_SOFT_SERIAL_INTERRUPT
    169 void 	comsoft(void);
    170 #else
    171 void 	comsoft(void *);
    172 static struct callout comsoft_callout = CALLOUT_INITIALIZER;
    173 #endif
    174 #endif
    175 integrate void com_rxsoft(struct com_softc *, struct tty *);
    176 integrate void com_txsoft(struct com_softc *, struct tty *);
    177 integrate void com_stsoft(struct com_softc *, struct tty *);
    178 integrate void com_schedrx(struct com_softc *);
    179 void	comdiag(void *);
    180 
    181 extern struct cfdriver com_cd;
    182 
    183 dev_type_open(comopen);
    184 dev_type_close(comclose);
    185 dev_type_read(comread);
    186 dev_type_write(comwrite);
    187 dev_type_ioctl(comioctl);
    188 dev_type_stop(comstop);
    189 dev_type_tty(comtty);
    190 dev_type_poll(compoll);
    191 
    192 const struct cdevsw com_cdevsw = {
    193 	comopen, comclose, comread, comwrite, comioctl,
    194 	comstop, comtty, compoll, nommap, ttykqfilter, D_TTY
    195 };
    196 
    197 /*
    198  * Make this an option variable one can patch.
    199  * But be warned:  this must be a power of 2!
    200  */
    201 u_int com_rbuf_size = COM_RING_SIZE;
    202 
    203 /* Stop input when 3/4 of the ring is full; restart when only 1/4 is full. */
    204 u_int com_rbuf_hiwat = (COM_RING_SIZE * 1) / 4;
    205 u_int com_rbuf_lowat = (COM_RING_SIZE * 3) / 4;
    206 
    207 static bus_addr_t	comconsaddr;
    208 static bus_space_tag_t comconstag;
    209 static bus_space_handle_t comconsioh;
    210 static int	comconsattached;
    211 static int comconsrate;
    212 static tcflag_t comconscflag;
    213 static struct cnm_state com_cnm_state;
    214 
    215 static int ppscap =
    216 	PPS_TSFMT_TSPEC |
    217 	PPS_CAPTUREASSERT |
    218 	PPS_CAPTURECLEAR |
    219 	PPS_OFFSETASSERT | PPS_OFFSETCLEAR;
    220 
    221 #ifndef __HAVE_GENERIC_SOFT_INTERRUPTS
    222 #ifdef __NO_SOFT_SERIAL_INTERRUPT
    223 volatile int	com_softintr_scheduled;
    224 #endif
    225 #endif
    226 
    227 #ifdef KGDB
    228 #include <sys/kgdb.h>
    229 
    230 static bus_addr_t com_kgdb_addr;
    231 static bus_space_tag_t com_kgdb_iot;
    232 static bus_space_handle_t com_kgdb_ioh;
    233 static int com_kgdb_attached;
    234 
    235 int	com_kgdb_getc(void *);
    236 void	com_kgdb_putc(void *, int);
    237 #endif /* KGDB */
    238 
    239 #define	COMUNIT_MASK	0x7ffff
    240 #define	COMDIALOUT_MASK	0x80000
    241 
    242 #define	COMUNIT(x)	(minor(x) & COMUNIT_MASK)
    243 #define	COMDIALOUT(x)	(minor(x) & COMDIALOUT_MASK)
    244 
    245 #define	COM_ISALIVE(sc)	((sc)->enabled != 0 && \
    246 			 ISSET((sc)->sc_dev.dv_flags, DVF_ACTIVE))
    247 
    248 #define	BR	BUS_SPACE_BARRIER_READ
    249 #define	BW	BUS_SPACE_BARRIER_WRITE
    250 #define COM_BARRIER(t, h, f) bus_space_barrier((t), (h), 0, COM_NPORTS, (f))
    251 
    252 #if (defined(MULTIPROCESSOR) || defined(LOCKDEBUG)) && defined(COM_MPLOCK)
    253 
    254 #define COM_LOCK(sc) simple_lock(&(sc)->sc_lock)
    255 #define COM_UNLOCK(sc) simple_unlock(&(sc)->sc_lock)
    256 
    257 #else
    258 
    259 #define COM_LOCK(sc)
    260 #define COM_UNLOCK(sc)
    261 
    262 #endif
    263 
    264 /*ARGSUSED*/
    265 int
    266 comspeed(long speed, long frequency, int type)
    267 {
    268 #define	divrnd(n, q)	(((n)*2/(q)+1)/2)	/* divide and round off */
    269 
    270 	int x, err;
    271 
    272 #if 0
    273 	if (speed == 0)
    274 		return (0);
    275 #endif
    276 	if (speed <= 0)
    277 		return (-1);
    278 	x = divrnd(frequency / 16, speed);
    279 	if (x <= 0)
    280 		return (-1);
    281 	err = divrnd(((quad_t)frequency) * 1000 / 16, speed * x) - 1000;
    282 	if (err < 0)
    283 		err = -err;
    284 	if (err > COM_TOLERANCE)
    285 		return (-1);
    286 	return (x);
    287 
    288 #undef	divrnd
    289 }
    290 
    291 #ifdef COM_DEBUG
    292 int	com_debug = 0;
    293 
    294 void comstatus(struct com_softc *, char *);
    295 void
    296 comstatus(struct com_softc *sc, char *str)
    297 {
    298 	struct tty *tp = sc->sc_tty;
    299 
    300 	printf("%s: %s %cclocal  %cdcd %cts_carr_on %cdtr %ctx_stopped\n",
    301 	    sc->sc_dev.dv_xname, str,
    302 	    ISSET(tp->t_cflag, CLOCAL) ? '+' : '-',
    303 	    ISSET(sc->sc_msr, MSR_DCD) ? '+' : '-',
    304 	    ISSET(tp->t_state, TS_CARR_ON) ? '+' : '-',
    305 	    ISSET(sc->sc_mcr, MCR_DTR) ? '+' : '-',
    306 	    sc->sc_tx_stopped ? '+' : '-');
    307 
    308 	printf("%s: %s %ccrtscts %ccts %cts_ttstop  %crts rx_flags=0x%x\n",
    309 	    sc->sc_dev.dv_xname, str,
    310 	    ISSET(tp->t_cflag, CRTSCTS) ? '+' : '-',
    311 	    ISSET(sc->sc_msr, MSR_CTS) ? '+' : '-',
    312 	    ISSET(tp->t_state, TS_TTSTOP) ? '+' : '-',
    313 	    ISSET(sc->sc_mcr, MCR_RTS) ? '+' : '-',
    314 	    sc->sc_rx_flags);
    315 }
    316 #endif
    317 
    318 int
    319 comprobe1(bus_space_tag_t iot, bus_space_handle_t ioh)
    320 {
    321 
    322 	/* force access to id reg */
    323 	bus_space_write_1(iot, ioh, com_lcr, LCR_8BITS);
    324 	bus_space_write_1(iot, ioh, com_iir, 0);
    325 	if ((bus_space_read_1(iot, ioh, com_lcr) != LCR_8BITS) ||
    326 	    (bus_space_read_1(iot, ioh, com_iir) & 0x38))
    327 		return (0);
    328 
    329 	return (1);
    330 }
    331 
    332 #ifdef COM_HAYESP
    333 int
    334 comprobeHAYESP(bus_space_handle_t hayespioh, struct com_softc *sc)
    335 {
    336 	char	val, dips;
    337 	int	combaselist[] = { 0x3f8, 0x2f8, 0x3e8, 0x2e8 };
    338 	bus_space_tag_t iot = sc->sc_iot;
    339 
    340 	/*
    341 	 * Hayes ESP cards have two iobases.  One is for compatibility with
    342 	 * 16550 serial chips, and at the same ISA PC base addresses.  The
    343 	 * other is for ESP-specific enhanced features, and lies at a
    344 	 * different addressing range entirely (0x140, 0x180, 0x280, or 0x300).
    345 	 */
    346 
    347 	/* Test for ESP signature */
    348 	if ((bus_space_read_1(iot, hayespioh, 0) & 0xf3) == 0)
    349 		return (0);
    350 
    351 	/*
    352 	 * ESP is present at ESP enhanced base address; unknown com port
    353 	 */
    354 
    355 	/* Get the dip-switch configurations */
    356 	bus_space_write_1(iot, hayespioh, HAYESP_CMD1, HAYESP_GETDIPS);
    357 	dips = bus_space_read_1(iot, hayespioh, HAYESP_STATUS1);
    358 
    359 	/* Determine which com port this ESP card services: bits 0,1 of  */
    360 	/*  dips is the port # (0-3); combaselist[val] is the com_iobase */
    361 	if (sc->sc_iobase != combaselist[dips & 0x03])
    362 		return (0);
    363 
    364 	printf(": ESP");
    365 
    366  	/* Check ESP Self Test bits. */
    367 	/* Check for ESP version 2.0: bits 4,5,6 == 010 */
    368 	bus_space_write_1(iot, hayespioh, HAYESP_CMD1, HAYESP_GETTEST);
    369 	val = bus_space_read_1(iot, hayespioh, HAYESP_STATUS1); /* Clear reg1 */
    370 	val = bus_space_read_1(iot, hayespioh, HAYESP_STATUS2);
    371 	if ((val & 0x70) < 0x20) {
    372 		printf("-old (%o)", val & 0x70);
    373 		/* we do not support the necessary features */
    374 		return (0);
    375 	}
    376 
    377 	/* Check for ability to emulate 16550: bit 8 == 1 */
    378 	if ((dips & 0x80) == 0) {
    379 		printf(" slave");
    380 		/* XXX Does slave really mean no 16550 support?? */
    381 		return (0);
    382 	}
    383 
    384 	/*
    385 	 * If we made it this far, we are a full-featured ESP v2.0 (or
    386 	 * better), at the correct com port address.
    387 	 */
    388 
    389 	sc->sc_type = COM_TYPE_HAYESP;
    390 	printf(", 1024 byte fifo\n");
    391 	return (1);
    392 }
    393 #endif
    394 
    395 static void
    396 com_enable_debugport(struct com_softc *sc)
    397 {
    398 	int s;
    399 
    400 	/* Turn on line break interrupt, set carrier. */
    401 	s = splserial();
    402 	COM_LOCK(sc);
    403 	sc->sc_ier = IER_ERXRDY;
    404 #ifdef COM_PXA2X0
    405 	if (sc->sc_type == COM_TYPE_PXA2x0)
    406 		sc->sc_ier |= IER_EUART | IER_ERXTOUT;
    407 #endif
    408 	bus_space_write_1(sc->sc_iot, sc->sc_ioh, com_ier, sc->sc_ier);
    409 	SET(sc->sc_mcr, MCR_DTR | MCR_RTS);
    410 	bus_space_write_1(sc->sc_iot, sc->sc_ioh, com_mcr, sc->sc_mcr);
    411 	COM_UNLOCK(sc);
    412 	splx(s);
    413 }
    414 
    415 void
    416 com_attach_subr(struct com_softc *sc)
    417 {
    418 	bus_addr_t iobase = sc->sc_iobase;
    419 	bus_space_tag_t iot = sc->sc_iot;
    420 	bus_space_handle_t ioh = sc->sc_ioh;
    421 	struct tty *tp;
    422 #ifdef COM16650
    423 	u_int8_t lcr;
    424 #endif
    425 #ifdef COM_HAYESP
    426 	int	hayesp_ports[] = { 0x140, 0x180, 0x280, 0x300, 0 };
    427 	int	*hayespp;
    428 #endif
    429 	const char *fifo_msg = NULL;
    430 
    431 	callout_init(&sc->sc_diag_callout);
    432 #if (defined(MULTIPROCESSOR) || defined(LOCKDEBUG)) && defined(COM_MPLOCK)
    433 	simple_lock_init(&sc->sc_lock);
    434 #endif
    435 
    436 	/* Disable interrupts before configuring the device. */
    437 #ifdef COM_PXA2X0
    438 	if (sc->sc_type == COM_TYPE_PXA2x0)
    439 		sc->sc_ier = IER_EUART;
    440 	else
    441 #endif
    442 		sc->sc_ier = 0;
    443 	bus_space_write_1(iot, ioh, com_ier, sc->sc_ier);
    444 
    445 	if (iot == comconstag && iobase == comconsaddr) {
    446 		comconsattached = 1;
    447 
    448 		/* Make sure the console is always "hardwired". */
    449 		delay(1000);			/* wait for output to finish */
    450 		SET(sc->sc_hwflags, COM_HW_CONSOLE);
    451 		SET(sc->sc_swflags, TIOCFLAG_SOFTCAR);
    452 	}
    453 
    454 #ifdef COM_HAYESP
    455 	sc->sc_prescaler = 0;			/* set prescaler to x1. */
    456 
    457 	/* Look for a Hayes ESP board. */
    458 	for (hayespp = hayesp_ports; *hayespp != 0; hayespp++) {
    459 		bus_space_handle_t hayespioh;
    460 
    461 #define	HAYESP_NPORTS	8			/* XXX XXX XXX ??? ??? ??? */
    462 		if (bus_space_map(iot, *hayespp, HAYESP_NPORTS, 0, &hayespioh))
    463 			continue;
    464 		if (comprobeHAYESP(hayespioh, sc)) {
    465 			sc->sc_hayespioh = hayespioh;
    466 			sc->sc_fifolen = 1024;
    467 
    468 			break;
    469 		}
    470 		bus_space_unmap(iot, hayespioh, HAYESP_NPORTS);
    471 	}
    472 	/* No ESP; look for other things. */
    473 	if (sc->sc_type != COM_TYPE_HAYESP) {
    474 #endif
    475 	sc->sc_fifolen = 1;
    476 	/* look for a NS 16550AF UART with FIFOs */
    477 	bus_space_write_1(iot, ioh, com_fifo,
    478 	    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_14);
    479 	delay(100);
    480 	if (ISSET(bus_space_read_1(iot, ioh, com_iir), IIR_FIFO_MASK)
    481 	    == IIR_FIFO_MASK)
    482 		if (ISSET(bus_space_read_1(iot, ioh, com_fifo), FIFO_TRIGGER_14)
    483 		    == FIFO_TRIGGER_14) {
    484 			SET(sc->sc_hwflags, COM_HW_FIFO);
    485 
    486 #ifdef COM16650
    487 			/*
    488 			 * IIR changes into the EFR if LCR is set to LCR_EERS
    489 			 * on 16650s. We also know IIR != 0 at this point.
    490 			 * Write 0 into the EFR, and read it. If the result
    491 			 * is 0, we have a 16650.
    492 			 *
    493 			 * Older 16650s were broken; the test to detect them
    494 			 * is taken from the Linux driver. Apparently
    495 			 * setting DLAB enable gives access to the EFR on
    496 			 * these chips.
    497 			 */
    498 			lcr = bus_space_read_1(iot, ioh, com_lcr);
    499 			bus_space_write_1(iot, ioh, com_lcr, LCR_EERS);
    500 			bus_space_write_1(iot, ioh, com_efr, 0);
    501 			if (bus_space_read_1(iot, ioh, com_efr) == 0) {
    502 				bus_space_write_1(iot, ioh, com_lcr,
    503 				    lcr | LCR_DLAB);
    504 				if (bus_space_read_1(iot, ioh, com_efr) == 0) {
    505 					CLR(sc->sc_hwflags, COM_HW_FIFO);
    506 					sc->sc_fifolen = 0;
    507 				} else {
    508 					SET(sc->sc_hwflags, COM_HW_FLOW);
    509 					sc->sc_fifolen = 32;
    510 				}
    511 			} else
    512 #endif
    513 				sc->sc_fifolen = 16;
    514 
    515 #ifdef COM16650
    516 			bus_space_write_1(iot, ioh, com_lcr, lcr);
    517 			if (sc->sc_fifolen == 0)
    518 				fifo_msg = "st16650, broken fifo";
    519 			else if (sc->sc_fifolen == 32)
    520 				fifo_msg = "st16650a, working fifo";
    521 			else
    522 #endif
    523 				fifo_msg = "ns16550a, working fifo";
    524 		} else
    525 			fifo_msg = "ns16550, broken fifo";
    526 	else
    527 		fifo_msg = "ns8250 or ns16450, no fifo";
    528 	bus_space_write_1(iot, ioh, com_fifo, 0);
    529 	/*
    530 	 * Some chips will clear down both Tx and Rx FIFOs when zero is
    531 	 * written to com_fifo. If this chip is the console, writing zero
    532 	 * results in some of the chip/FIFO description being lost, so delay
    533 	 * printing it until now.
    534 	 */
    535 	delay(10);
    536 	aprint_normal(": %s\n", fifo_msg);
    537 	if (ISSET(sc->sc_hwflags, COM_HW_TXFIFO_DISABLE)) {
    538 		sc->sc_fifolen = 1;
    539 		aprint_normal("%s: txfifo disabled\n", sc->sc_dev.dv_xname);
    540 	}
    541 #ifdef COM_HAYESP
    542 	}
    543 #endif
    544 
    545 	tp = ttymalloc();
    546 	tp->t_oproc = comstart;
    547 	tp->t_param = comparam;
    548 	tp->t_hwiflow = comhwiflow;
    549 
    550 	sc->sc_tty = tp;
    551 	sc->sc_rbuf = malloc(com_rbuf_size << 1, M_DEVBUF, M_NOWAIT);
    552 	sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
    553 	sc->sc_rbavail = com_rbuf_size;
    554 	if (sc->sc_rbuf == NULL) {
    555 		aprint_error("%s: unable to allocate ring buffer\n",
    556 		    sc->sc_dev.dv_xname);
    557 		return;
    558 	}
    559 	sc->sc_ebuf = sc->sc_rbuf + (com_rbuf_size << 1);
    560 
    561 	tty_attach(tp);
    562 
    563 	if (!ISSET(sc->sc_hwflags, COM_HW_NOIEN))
    564 		SET(sc->sc_mcr, MCR_IENABLE);
    565 
    566 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
    567 		int maj;
    568 
    569 		/* locate the major number */
    570 		maj = cdevsw_lookup_major(&com_cdevsw);
    571 
    572 		tp->t_dev = cn_tab->cn_dev = makedev(maj, sc->sc_dev.dv_unit);
    573 
    574 		aprint_normal("%s: console\n", sc->sc_dev.dv_xname);
    575 	}
    576 
    577 #ifdef KGDB
    578 	/*
    579 	 * Allow kgdb to "take over" this port.  If this is
    580 	 * not the console and is the kgdb device, it has
    581 	 * exclusive use.  If it's the console _and_ the
    582 	 * kgdb device, it doesn't.
    583 	 */
    584 	if (iot == com_kgdb_iot && iobase == com_kgdb_addr) {
    585 		if (!ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
    586 			com_kgdb_attached = 1;
    587 
    588 			SET(sc->sc_hwflags, COM_HW_KGDB);
    589 		}
    590 		aprint_normal("%s: kgdb\n", sc->sc_dev.dv_xname);
    591 	}
    592 #endif
    593 
    594 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
    595 	sc->sc_si = softintr_establish(IPL_SOFTSERIAL, comsoft, sc);
    596 #endif
    597 
    598 #if NRND > 0 && defined(RND_COM)
    599 	rnd_attach_source(&sc->rnd_source, sc->sc_dev.dv_xname,
    600 			  RND_TYPE_TTY, 0);
    601 #endif
    602 
    603 	/* if there are no enable/disable functions, assume the device
    604 	   is always enabled */
    605 	if (!sc->enable)
    606 		sc->enabled = 1;
    607 
    608 	com_config(sc);
    609 
    610 	SET(sc->sc_hwflags, COM_HW_DEV_OK);
    611 }
    612 
    613 void
    614 com_config(struct com_softc *sc)
    615 {
    616 	bus_space_tag_t iot = sc->sc_iot;
    617 	bus_space_handle_t ioh = sc->sc_ioh;
    618 
    619 	/* Disable interrupts before configuring the device. */
    620 #ifdef COM_PXA2X0
    621 	if (sc->sc_type == COM_TYPE_PXA2x0)
    622 		sc->sc_ier = IER_EUART;
    623 	else
    624 #endif
    625 		sc->sc_ier = 0;
    626 	bus_space_write_1(iot, ioh, com_ier, sc->sc_ier);
    627 
    628 #ifdef COM_HAYESP
    629 	/* Look for a Hayes ESP board. */
    630 	if (sc->sc_type == COM_TYPE_HAYESP) {
    631 		sc->sc_fifolen = 1024;
    632 
    633 		/* Set 16550 compatibility mode */
    634 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD1,
    635 				  HAYESP_SETMODE);
    636 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
    637 				  HAYESP_MODE_FIFO|HAYESP_MODE_RTS|
    638 				  HAYESP_MODE_SCALE);
    639 
    640 		/* Set RTS/CTS flow control */
    641 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD1,
    642 				  HAYESP_SETFLOWTYPE);
    643 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
    644 				  HAYESP_FLOW_RTS);
    645 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
    646 				  HAYESP_FLOW_CTS);
    647 
    648 		/* Set flow control levels */
    649 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD1,
    650 				  HAYESP_SETRXFLOW);
    651 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
    652 				  HAYESP_HIBYTE(HAYESP_RXHIWMARK));
    653 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
    654 				  HAYESP_LOBYTE(HAYESP_RXHIWMARK));
    655 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
    656 				  HAYESP_HIBYTE(HAYESP_RXLOWMARK));
    657 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
    658 				  HAYESP_LOBYTE(HAYESP_RXLOWMARK));
    659 	}
    660 #endif
    661 
    662 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE|COM_HW_KGDB))
    663 		com_enable_debugport(sc);
    664 }
    665 
    666 int
    667 com_detach(struct device *self, int flags)
    668 {
    669 	struct com_softc *sc = (struct com_softc *)self;
    670 	int maj, mn;
    671 
    672 	/* locate the major number */
    673 	maj = cdevsw_lookup_major(&com_cdevsw);
    674 
    675 	/* Nuke the vnodes for any open instances. */
    676 	mn = self->dv_unit;
    677 	vdevgone(maj, mn, mn, VCHR);
    678 
    679 	mn |= COMDIALOUT_MASK;
    680 	vdevgone(maj, mn, mn, VCHR);
    681 
    682 	if (sc->sc_rbuf == NULL) {
    683 		/*
    684 		 * Ring buffer allocation failed in the com_attach_subr,
    685 		 * only the tty is allocated, and nothing else.
    686 		 */
    687 		ttyfree(sc->sc_tty);
    688 		return 0;
    689 	}
    690 
    691 	/* Free the receive buffer. */
    692 	free(sc->sc_rbuf, M_DEVBUF);
    693 
    694 	/* Detach and free the tty. */
    695 	tty_detach(sc->sc_tty);
    696 	ttyfree(sc->sc_tty);
    697 
    698 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
    699 	/* Unhook the soft interrupt handler. */
    700 	softintr_disestablish(sc->sc_si);
    701 #endif
    702 
    703 #if NRND > 0 && defined(RND_COM)
    704 	/* Unhook the entropy source. */
    705 	rnd_detach_source(&sc->rnd_source);
    706 #endif
    707 
    708 	return (0);
    709 }
    710 
    711 int
    712 com_activate(struct device *self, enum devact act)
    713 {
    714 	struct com_softc *sc = (struct com_softc *)self;
    715 	int s, rv = 0;
    716 
    717 	s = splserial();
    718 	COM_LOCK(sc);
    719 	switch (act) {
    720 	case DVACT_ACTIVATE:
    721 		rv = EOPNOTSUPP;
    722 		break;
    723 
    724 	case DVACT_DEACTIVATE:
    725 		if (sc->sc_hwflags & (COM_HW_CONSOLE|COM_HW_KGDB)) {
    726 			rv = EBUSY;
    727 			break;
    728 		}
    729 
    730 		if (sc->disable != NULL && sc->enabled != 0) {
    731 			(*sc->disable)(sc);
    732 			sc->enabled = 0;
    733 		}
    734 		break;
    735 	}
    736 
    737 	COM_UNLOCK(sc);
    738 	splx(s);
    739 	return (rv);
    740 }
    741 
    742 void
    743 com_shutdown(struct com_softc *sc)
    744 {
    745 	struct tty *tp = sc->sc_tty;
    746 	int s;
    747 
    748 	s = splserial();
    749 	COM_LOCK(sc);
    750 
    751 	/* If we were asserting flow control, then deassert it. */
    752 	SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
    753 	com_hwiflow(sc);
    754 
    755 	/* Clear any break condition set with TIOCSBRK. */
    756 	com_break(sc, 0);
    757 
    758 	/* Turn off PPS capture on last close. */
    759 	sc->sc_ppsmask = 0;
    760 	sc->ppsparam.mode = 0;
    761 
    762 	/*
    763 	 * Hang up if necessary.  Wait a bit, so the other side has time to
    764 	 * notice even if we immediately open the port again.
    765 	 * Avoid tsleeping above splhigh().
    766 	 */
    767 	if (ISSET(tp->t_cflag, HUPCL)) {
    768 		com_modem(sc, 0);
    769 		COM_UNLOCK(sc);
    770 		splx(s);
    771 		/* XXX tsleep will only timeout */
    772 		(void) tsleep(sc, TTIPRI, ttclos, hz);
    773 		s = splserial();
    774 		COM_LOCK(sc);
    775 	}
    776 
    777 	/* Turn off interrupts. */
    778 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
    779 		sc->sc_ier = IER_ERXRDY; /* interrupt on break */
    780 #ifdef COM_PXA2X0
    781 		if (sc->sc_type == COM_TYPE_PXA2x0)
    782 			sc->sc_ier |= IER_ERXTOUT;
    783 #endif
    784 	} else
    785 		sc->sc_ier = 0;
    786 
    787 #ifdef COM_PXA2X0
    788 	if (sc->sc_type == COM_TYPE_PXA2x0)
    789 		sc->sc_ier |= IER_EUART;
    790 #endif
    791 
    792 	bus_space_write_1(sc->sc_iot, sc->sc_ioh, com_ier, sc->sc_ier);
    793 
    794 	if (sc->disable) {
    795 #ifdef DIAGNOSTIC
    796 		if (!sc->enabled)
    797 			panic("com_shutdown: not enabled?");
    798 #endif
    799 		(*sc->disable)(sc);
    800 		sc->enabled = 0;
    801 	}
    802 	COM_UNLOCK(sc);
    803 	splx(s);
    804 }
    805 
    806 int
    807 comopen(dev_t dev, int flag, int mode, struct proc *p)
    808 {
    809 	struct com_softc *sc;
    810 	struct tty *tp;
    811 	int s, s2;
    812 	int error;
    813 
    814 	sc = device_lookup(&com_cd, COMUNIT(dev));
    815 	if (sc == NULL || !ISSET(sc->sc_hwflags, COM_HW_DEV_OK) ||
    816 		sc->sc_rbuf == NULL)
    817 		return (ENXIO);
    818 
    819 	if (ISSET(sc->sc_dev.dv_flags, DVF_ACTIVE) == 0)
    820 		return (ENXIO);
    821 
    822 #ifdef KGDB
    823 	/*
    824 	 * If this is the kgdb port, no other use is permitted.
    825 	 */
    826 	if (ISSET(sc->sc_hwflags, COM_HW_KGDB))
    827 		return (EBUSY);
    828 #endif
    829 
    830 	tp = sc->sc_tty;
    831 
    832 	if (ISSET(tp->t_state, TS_ISOPEN) &&
    833 	    ISSET(tp->t_state, TS_XCLUDE) &&
    834 		p->p_ucred->cr_uid != 0)
    835 		return (EBUSY);
    836 
    837 	s = spltty();
    838 
    839 	/*
    840 	 * Do the following iff this is a first open.
    841 	 */
    842 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
    843 		struct termios t;
    844 
    845 		tp->t_dev = dev;
    846 
    847 		s2 = splserial();
    848 		COM_LOCK(sc);
    849 
    850 		if (sc->enable) {
    851 			if ((*sc->enable)(sc)) {
    852 				COM_UNLOCK(sc);
    853 				splx(s2);
    854 				splx(s);
    855 				printf("%s: device enable failed\n",
    856 				       sc->sc_dev.dv_xname);
    857 				return (EIO);
    858 			}
    859 			sc->enabled = 1;
    860 			com_config(sc);
    861 		}
    862 
    863 		/* Turn on interrupts. */
    864 		sc->sc_ier = IER_ERXRDY | IER_ERLS | IER_EMSC;
    865 #ifdef COM_PXA2X0
    866 		if (sc->sc_type == COM_TYPE_PXA2x0)
    867 			sc->sc_ier |= IER_EUART | IER_ERXTOUT;
    868 #endif
    869 		bus_space_write_1(sc->sc_iot, sc->sc_ioh, com_ier, sc->sc_ier);
    870 
    871 		/* Fetch the current modem control status, needed later. */
    872 		sc->sc_msr = bus_space_read_1(sc->sc_iot, sc->sc_ioh, com_msr);
    873 
    874 		/* Clear PPS capture state on first open. */
    875 		sc->sc_ppsmask = 0;
    876 		sc->ppsparam.mode = 0;
    877 
    878 		COM_UNLOCK(sc);
    879 		splx(s2);
    880 
    881 		/*
    882 		 * Initialize the termios status to the defaults.  Add in the
    883 		 * sticky bits from TIOCSFLAGS.
    884 		 */
    885 		t.c_ispeed = 0;
    886 		if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
    887 			t.c_ospeed = comconsrate;
    888 			t.c_cflag = comconscflag;
    889 		} else {
    890 			t.c_ospeed = TTYDEF_SPEED;
    891 			t.c_cflag = TTYDEF_CFLAG;
    892 		}
    893 		if (ISSET(sc->sc_swflags, TIOCFLAG_CLOCAL))
    894 			SET(t.c_cflag, CLOCAL);
    895 		if (ISSET(sc->sc_swflags, TIOCFLAG_CRTSCTS))
    896 			SET(t.c_cflag, CRTSCTS);
    897 		if (ISSET(sc->sc_swflags, TIOCFLAG_MDMBUF))
    898 			SET(t.c_cflag, MDMBUF);
    899 		/* Make sure comparam() will do something. */
    900 		tp->t_ospeed = 0;
    901 		(void) comparam(tp, &t);
    902 		tp->t_iflag = TTYDEF_IFLAG;
    903 		tp->t_oflag = TTYDEF_OFLAG;
    904 		tp->t_lflag = TTYDEF_LFLAG;
    905 		ttychars(tp);
    906 		ttsetwater(tp);
    907 
    908 		s2 = splserial();
    909 		COM_LOCK(sc);
    910 
    911 		/*
    912 		 * Turn on DTR.  We must always do this, even if carrier is not
    913 		 * present, because otherwise we'd have to use TIOCSDTR
    914 		 * immediately after setting CLOCAL, which applications do not
    915 		 * expect.  We always assert DTR while the device is open
    916 		 * unless explicitly requested to deassert it.
    917 		 */
    918 		com_modem(sc, 1);
    919 
    920 		/* Clear the input ring, and unblock. */
    921 		sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
    922 		sc->sc_rbavail = com_rbuf_size;
    923 		com_iflush(sc);
    924 		CLR(sc->sc_rx_flags, RX_ANY_BLOCK);
    925 		com_hwiflow(sc);
    926 
    927 #ifdef COM_DEBUG
    928 		if (com_debug)
    929 			comstatus(sc, "comopen  ");
    930 #endif
    931 
    932 		COM_UNLOCK(sc);
    933 		splx(s2);
    934 	}
    935 
    936 	splx(s);
    937 
    938 	error = ttyopen(tp, COMDIALOUT(dev), ISSET(flag, O_NONBLOCK));
    939 	if (error)
    940 		goto bad;
    941 
    942 	error = (*tp->t_linesw->l_open)(dev, tp);
    943 	if (error)
    944 		goto bad;
    945 
    946 	return (0);
    947 
    948 bad:
    949 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
    950 		/*
    951 		 * We failed to open the device, and nobody else had it opened.
    952 		 * Clean up the state as appropriate.
    953 		 */
    954 		com_shutdown(sc);
    955 	}
    956 
    957 	return (error);
    958 }
    959 
    960 int
    961 comclose(dev_t dev, int flag, int mode, struct proc *p)
    962 {
    963 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(dev));
    964 	struct tty *tp = sc->sc_tty;
    965 
    966 	/* XXX This is for cons.c. */
    967 	if (!ISSET(tp->t_state, TS_ISOPEN))
    968 		return (0);
    969 
    970 	(*tp->t_linesw->l_close)(tp, flag);
    971 	ttyclose(tp);
    972 
    973 	if (COM_ISALIVE(sc) == 0)
    974 		return (0);
    975 
    976 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
    977 		/*
    978 		 * Although we got a last close, the device may still be in
    979 		 * use; e.g. if this was the dialout node, and there are still
    980 		 * processes waiting for carrier on the non-dialout node.
    981 		 */
    982 		com_shutdown(sc);
    983 	}
    984 
    985 	return (0);
    986 }
    987 
    988 int
    989 comread(dev_t dev, struct uio *uio, int flag)
    990 {
    991 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(dev));
    992 	struct tty *tp = sc->sc_tty;
    993 
    994 	if (COM_ISALIVE(sc) == 0)
    995 		return (EIO);
    996 
    997 	return ((*tp->t_linesw->l_read)(tp, uio, flag));
    998 }
    999 
   1000 int
   1001 comwrite(dev_t dev, struct uio *uio, int flag)
   1002 {
   1003 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(dev));
   1004 	struct tty *tp = sc->sc_tty;
   1005 
   1006 	if (COM_ISALIVE(sc) == 0)
   1007 		return (EIO);
   1008 
   1009 	return ((*tp->t_linesw->l_write)(tp, uio, flag));
   1010 }
   1011 
   1012 int
   1013 compoll(dev_t dev, int events, struct proc *p)
   1014 {
   1015 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(dev));
   1016 	struct tty *tp = sc->sc_tty;
   1017 
   1018 	if (COM_ISALIVE(sc) == 0)
   1019 		return (EIO);
   1020 
   1021 	return ((*tp->t_linesw->l_poll)(tp, events, p));
   1022 }
   1023 
   1024 struct tty *
   1025 comtty(dev_t dev)
   1026 {
   1027 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(dev));
   1028 	struct tty *tp = sc->sc_tty;
   1029 
   1030 	return (tp);
   1031 }
   1032 
   1033 int
   1034 comioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct proc *p)
   1035 {
   1036 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(dev));
   1037 	struct tty *tp = sc->sc_tty;
   1038 	int error;
   1039 	int s;
   1040 
   1041 	if (COM_ISALIVE(sc) == 0)
   1042 		return (EIO);
   1043 
   1044 	error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, p);
   1045 	if (error != EPASSTHROUGH)
   1046 		return (error);
   1047 
   1048 	error = ttioctl(tp, cmd, data, flag, p);
   1049 	if (error != EPASSTHROUGH)
   1050 		return (error);
   1051 
   1052 	error = 0;
   1053 
   1054 	s = splserial();
   1055 	COM_LOCK(sc);
   1056 
   1057 	switch (cmd) {
   1058 	case TIOCSBRK:
   1059 		com_break(sc, 1);
   1060 		break;
   1061 
   1062 	case TIOCCBRK:
   1063 		com_break(sc, 0);
   1064 		break;
   1065 
   1066 	case TIOCSDTR:
   1067 		com_modem(sc, 1);
   1068 		break;
   1069 
   1070 	case TIOCCDTR:
   1071 		com_modem(sc, 0);
   1072 		break;
   1073 
   1074 	case TIOCGFLAGS:
   1075 		*(int *)data = sc->sc_swflags;
   1076 		break;
   1077 
   1078 	case TIOCSFLAGS:
   1079 		error = suser(p->p_ucred, &p->p_acflag);
   1080 		if (error)
   1081 			break;
   1082 		sc->sc_swflags = *(int *)data;
   1083 		break;
   1084 
   1085 	case TIOCMSET:
   1086 	case TIOCMBIS:
   1087 	case TIOCMBIC:
   1088 		tiocm_to_com(sc, cmd, *(int *)data);
   1089 		break;
   1090 
   1091 	case TIOCMGET:
   1092 		*(int *)data = com_to_tiocm(sc);
   1093 		break;
   1094 
   1095 	case PPS_IOC_CREATE:
   1096 		break;
   1097 
   1098 	case PPS_IOC_DESTROY:
   1099 		break;
   1100 
   1101 	case PPS_IOC_GETPARAMS: {
   1102 		pps_params_t *pp;
   1103 		pp = (pps_params_t *)data;
   1104 		*pp = sc->ppsparam;
   1105 		break;
   1106 	}
   1107 
   1108 	case PPS_IOC_SETPARAMS: {
   1109 	  	pps_params_t *pp;
   1110 		int mode;
   1111 		pp = (pps_params_t *)data;
   1112 		if (pp->mode & ~ppscap) {
   1113 			error = EINVAL;
   1114 			break;
   1115 		}
   1116 		sc->ppsparam = *pp;
   1117 	 	/*
   1118 		 * Compute msr masks from user-specified timestamp state.
   1119 		 */
   1120 		mode = sc->ppsparam.mode;
   1121 		switch (mode & PPS_CAPTUREBOTH) {
   1122 		case 0:
   1123 			sc->sc_ppsmask = 0;
   1124 			break;
   1125 
   1126 		case PPS_CAPTUREASSERT:
   1127 			sc->sc_ppsmask = MSR_DCD;
   1128 			sc->sc_ppsassert = MSR_DCD;
   1129 			sc->sc_ppsclear = -1;
   1130 			break;
   1131 
   1132 		case PPS_CAPTURECLEAR:
   1133 			sc->sc_ppsmask = MSR_DCD;
   1134 			sc->sc_ppsassert = -1;
   1135 			sc->sc_ppsclear = 0;
   1136 			break;
   1137 
   1138 		case PPS_CAPTUREBOTH:
   1139 			sc->sc_ppsmask = MSR_DCD;
   1140 			sc->sc_ppsassert = MSR_DCD;
   1141 			sc->sc_ppsclear = 0;
   1142 			break;
   1143 
   1144 		default:
   1145 			error = EINVAL;
   1146 			break;
   1147 		}
   1148 		break;
   1149 	}
   1150 
   1151 	case PPS_IOC_GETCAP:
   1152 		*(int*)data = ppscap;
   1153 		break;
   1154 
   1155 	case PPS_IOC_FETCH: {
   1156 		pps_info_t *pi;
   1157 		pi = (pps_info_t *)data;
   1158 		*pi = sc->ppsinfo;
   1159 		break;
   1160 	}
   1161 
   1162 #ifdef PPS_SYNC
   1163 	case PPS_IOC_KCBIND: {
   1164 		int edge = (*(int *)data) & PPS_CAPTUREBOTH;
   1165 
   1166 		if (edge == 0) {
   1167 			/*
   1168 			 * remove binding for this source; ignore
   1169 			 * the request if this is not the current
   1170 			 * hardpps source
   1171 			 */
   1172 			if (pps_kc_hardpps_source == sc) {
   1173 				pps_kc_hardpps_source = NULL;
   1174 				pps_kc_hardpps_mode = 0;
   1175 			}
   1176 		} else {
   1177 			/*
   1178 			 * bind hardpps to this source, replacing any
   1179 			 * previously specified source or edges
   1180 			 */
   1181 			pps_kc_hardpps_source = sc;
   1182 			pps_kc_hardpps_mode = edge;
   1183 		}
   1184 		break;
   1185 	}
   1186 #endif /* PPS_SYNC */
   1187 
   1188 	case TIOCDCDTIMESTAMP:	/* XXX old, overloaded  API used by xntpd v3 */
   1189 		/*
   1190 		 * Some GPS clocks models use the falling rather than
   1191 		 * rising edge as the on-the-second signal.
   1192 		 * The old API has no way to specify PPS polarity.
   1193 		 */
   1194 		sc->sc_ppsmask = MSR_DCD;
   1195 #ifndef PPS_TRAILING_EDGE
   1196 		sc->sc_ppsassert = MSR_DCD;
   1197 		sc->sc_ppsclear = -1;
   1198 		TIMESPEC_TO_TIMEVAL((struct timeval *)data,
   1199 		    &sc->ppsinfo.assert_timestamp);
   1200 #else
   1201 		sc->sc_ppsassert = -1;
   1202 		sc->sc_ppsclear = 0;
   1203 		TIMESPEC_TO_TIMEVAL((struct timeval *)data,
   1204 		    &sc->ppsinfo.clear_timestamp);
   1205 #endif
   1206 		break;
   1207 
   1208 	default:
   1209 		error = EPASSTHROUGH;
   1210 		break;
   1211 	}
   1212 
   1213 	COM_UNLOCK(sc);
   1214 	splx(s);
   1215 
   1216 #ifdef COM_DEBUG
   1217 	if (com_debug)
   1218 		comstatus(sc, "comioctl ");
   1219 #endif
   1220 
   1221 	return (error);
   1222 }
   1223 
   1224 integrate void
   1225 com_schedrx(struct com_softc *sc)
   1226 {
   1227 
   1228 	sc->sc_rx_ready = 1;
   1229 
   1230 	/* Wake up the poller. */
   1231 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
   1232 	softintr_schedule(sc->sc_si);
   1233 #else
   1234 #ifndef __NO_SOFT_SERIAL_INTERRUPT
   1235 	setsoftserial();
   1236 #else
   1237 	if (!com_softintr_scheduled) {
   1238 		com_softintr_scheduled = 1;
   1239 		callout_reset(&comsoft_callout, 1, comsoft, NULL);
   1240 	}
   1241 #endif
   1242 #endif
   1243 }
   1244 
   1245 void
   1246 com_break(struct com_softc *sc, int onoff)
   1247 {
   1248 
   1249 	if (onoff)
   1250 		SET(sc->sc_lcr, LCR_SBREAK);
   1251 	else
   1252 		CLR(sc->sc_lcr, LCR_SBREAK);
   1253 
   1254 	if (!sc->sc_heldchange) {
   1255 		if (sc->sc_tx_busy) {
   1256 			sc->sc_heldtbc = sc->sc_tbc;
   1257 			sc->sc_tbc = 0;
   1258 			sc->sc_heldchange = 1;
   1259 		} else
   1260 			com_loadchannelregs(sc);
   1261 	}
   1262 }
   1263 
   1264 void
   1265 com_modem(struct com_softc *sc, int onoff)
   1266 {
   1267 
   1268 	if (sc->sc_mcr_dtr == 0)
   1269 		return;
   1270 
   1271 	if (onoff)
   1272 		SET(sc->sc_mcr, sc->sc_mcr_dtr);
   1273 	else
   1274 		CLR(sc->sc_mcr, sc->sc_mcr_dtr);
   1275 
   1276 	if (!sc->sc_heldchange) {
   1277 		if (sc->sc_tx_busy) {
   1278 			sc->sc_heldtbc = sc->sc_tbc;
   1279 			sc->sc_tbc = 0;
   1280 			sc->sc_heldchange = 1;
   1281 		} else
   1282 			com_loadchannelregs(sc);
   1283 	}
   1284 }
   1285 
   1286 void
   1287 tiocm_to_com(struct com_softc *sc, u_long how, int ttybits)
   1288 {
   1289 	u_char combits;
   1290 
   1291 	combits = 0;
   1292 	if (ISSET(ttybits, TIOCM_DTR))
   1293 		SET(combits, MCR_DTR);
   1294 	if (ISSET(ttybits, TIOCM_RTS))
   1295 		SET(combits, MCR_RTS);
   1296 
   1297 	switch (how) {
   1298 	case TIOCMBIC:
   1299 		CLR(sc->sc_mcr, combits);
   1300 		break;
   1301 
   1302 	case TIOCMBIS:
   1303 		SET(sc->sc_mcr, combits);
   1304 		break;
   1305 
   1306 	case TIOCMSET:
   1307 		CLR(sc->sc_mcr, MCR_DTR | MCR_RTS);
   1308 		SET(sc->sc_mcr, combits);
   1309 		break;
   1310 	}
   1311 
   1312 	if (!sc->sc_heldchange) {
   1313 		if (sc->sc_tx_busy) {
   1314 			sc->sc_heldtbc = sc->sc_tbc;
   1315 			sc->sc_tbc = 0;
   1316 			sc->sc_heldchange = 1;
   1317 		} else
   1318 			com_loadchannelregs(sc);
   1319 	}
   1320 }
   1321 
   1322 int
   1323 com_to_tiocm(struct com_softc *sc)
   1324 {
   1325 	u_char combits;
   1326 	int ttybits = 0;
   1327 
   1328 	combits = sc->sc_mcr;
   1329 	if (ISSET(combits, MCR_DTR))
   1330 		SET(ttybits, TIOCM_DTR);
   1331 	if (ISSET(combits, MCR_RTS))
   1332 		SET(ttybits, TIOCM_RTS);
   1333 
   1334 	combits = sc->sc_msr;
   1335 	if (ISSET(combits, MSR_DCD))
   1336 		SET(ttybits, TIOCM_CD);
   1337 	if (ISSET(combits, MSR_CTS))
   1338 		SET(ttybits, TIOCM_CTS);
   1339 	if (ISSET(combits, MSR_DSR))
   1340 		SET(ttybits, TIOCM_DSR);
   1341 	if (ISSET(combits, MSR_RI | MSR_TERI))
   1342 		SET(ttybits, TIOCM_RI);
   1343 
   1344 #ifdef COM_PXA2X0
   1345 	if (sc->sc_type == COM_TYPE_PXA2x0) {
   1346 		if ((sc->sc_ier & 0x0f) != 0)
   1347 			SET(ttybits, TIOCM_LE);
   1348 	} else
   1349 #endif
   1350 	if ((sc->sc_ier & 0xbf) != 0)
   1351 		SET(ttybits, TIOCM_LE);
   1352 
   1353 	return (ttybits);
   1354 }
   1355 
   1356 static u_char
   1357 cflag2lcr(tcflag_t cflag)
   1358 {
   1359 	u_char lcr = 0;
   1360 
   1361 	switch (ISSET(cflag, CSIZE)) {
   1362 	case CS5:
   1363 		SET(lcr, LCR_5BITS);
   1364 		break;
   1365 	case CS6:
   1366 		SET(lcr, LCR_6BITS);
   1367 		break;
   1368 	case CS7:
   1369 		SET(lcr, LCR_7BITS);
   1370 		break;
   1371 	case CS8:
   1372 		SET(lcr, LCR_8BITS);
   1373 		break;
   1374 	}
   1375 	if (ISSET(cflag, PARENB)) {
   1376 		SET(lcr, LCR_PENAB);
   1377 		if (!ISSET(cflag, PARODD))
   1378 			SET(lcr, LCR_PEVEN);
   1379 	}
   1380 	if (ISSET(cflag, CSTOPB))
   1381 		SET(lcr, LCR_STOPB);
   1382 
   1383 	return (lcr);
   1384 }
   1385 
   1386 int
   1387 comparam(struct tty *tp, struct termios *t)
   1388 {
   1389 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(tp->t_dev));
   1390 	int ospeed;
   1391 	u_char lcr;
   1392 	int s;
   1393 
   1394 	if (COM_ISALIVE(sc) == 0)
   1395 		return (EIO);
   1396 
   1397 #ifdef COM_HAYESP
   1398 	if (sc->sc_type == COM_TYPE_HAYESP) {
   1399 		int prescaler, speed;
   1400 
   1401 		/*
   1402 		 * Calculate UART clock prescaler.  It should be in
   1403 		 * range of 0 .. 3.
   1404 		 */
   1405 		for (prescaler = 0, speed = t->c_ospeed; prescaler < 4;
   1406 		    prescaler++, speed /= 2)
   1407 			if ((ospeed = comspeed(speed, sc->sc_frequency,
   1408 					       sc->sc_type)) > 0)
   1409 				break;
   1410 
   1411 		if (prescaler == 4)
   1412 			return (EINVAL);
   1413 		sc->sc_prescaler = prescaler;
   1414 	} else
   1415 #endif
   1416 	ospeed = comspeed(t->c_ospeed, sc->sc_frequency, sc->sc_type);
   1417 
   1418 	/* Check requested parameters. */
   1419 	if (ospeed < 0)
   1420 		return (EINVAL);
   1421 	if (t->c_ispeed && t->c_ispeed != t->c_ospeed)
   1422 		return (EINVAL);
   1423 
   1424 	/*
   1425 	 * For the console, always force CLOCAL and !HUPCL, so that the port
   1426 	 * is always active.
   1427 	 */
   1428 	if (ISSET(sc->sc_swflags, TIOCFLAG_SOFTCAR) ||
   1429 	    ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
   1430 		SET(t->c_cflag, CLOCAL);
   1431 		CLR(t->c_cflag, HUPCL);
   1432 	}
   1433 
   1434 	/*
   1435 	 * If there were no changes, don't do anything.  This avoids dropping
   1436 	 * input and improves performance when all we did was frob things like
   1437 	 * VMIN and VTIME.
   1438 	 */
   1439 	if (tp->t_ospeed == t->c_ospeed &&
   1440 	    tp->t_cflag == t->c_cflag)
   1441 		return (0);
   1442 
   1443 	lcr = ISSET(sc->sc_lcr, LCR_SBREAK) | cflag2lcr(t->c_cflag);
   1444 
   1445 	s = splserial();
   1446 	COM_LOCK(sc);
   1447 
   1448 	sc->sc_lcr = lcr;
   1449 
   1450 	/*
   1451 	 * If we're not in a mode that assumes a connection is present, then
   1452 	 * ignore carrier changes.
   1453 	 */
   1454 	if (ISSET(t->c_cflag, CLOCAL | MDMBUF))
   1455 		sc->sc_msr_dcd = 0;
   1456 	else
   1457 		sc->sc_msr_dcd = MSR_DCD;
   1458 	/*
   1459 	 * Set the flow control pins depending on the current flow control
   1460 	 * mode.
   1461 	 */
   1462 	if (ISSET(t->c_cflag, CRTSCTS)) {
   1463 		sc->sc_mcr_dtr = MCR_DTR;
   1464 		sc->sc_mcr_rts = MCR_RTS;
   1465 		sc->sc_msr_cts = MSR_CTS;
   1466 		sc->sc_efr = EFR_AUTORTS | EFR_AUTOCTS;
   1467 	} else if (ISSET(t->c_cflag, MDMBUF)) {
   1468 		/*
   1469 		 * For DTR/DCD flow control, make sure we don't toggle DTR for
   1470 		 * carrier detection.
   1471 		 */
   1472 		sc->sc_mcr_dtr = 0;
   1473 		sc->sc_mcr_rts = MCR_DTR;
   1474 		sc->sc_msr_cts = MSR_DCD;
   1475 		sc->sc_efr = 0;
   1476 	} else {
   1477 		/*
   1478 		 * If no flow control, then always set RTS.  This will make
   1479 		 * the other side happy if it mistakenly thinks we're doing
   1480 		 * RTS/CTS flow control.
   1481 		 */
   1482 		sc->sc_mcr_dtr = MCR_DTR | MCR_RTS;
   1483 		sc->sc_mcr_rts = 0;
   1484 		sc->sc_msr_cts = 0;
   1485 		sc->sc_efr = 0;
   1486 		if (ISSET(sc->sc_mcr, MCR_DTR))
   1487 			SET(sc->sc_mcr, MCR_RTS);
   1488 		else
   1489 			CLR(sc->sc_mcr, MCR_RTS);
   1490 	}
   1491 	sc->sc_msr_mask = sc->sc_msr_cts | sc->sc_msr_dcd;
   1492 
   1493 #if 0
   1494 	if (ospeed == 0)
   1495 		CLR(sc->sc_mcr, sc->sc_mcr_dtr);
   1496 	else
   1497 		SET(sc->sc_mcr, sc->sc_mcr_dtr);
   1498 #endif
   1499 
   1500 	sc->sc_dlbl = ospeed;
   1501 	sc->sc_dlbh = ospeed >> 8;
   1502 
   1503 	/*
   1504 	 * Set the FIFO threshold based on the receive speed.
   1505 	 *
   1506 	 *  * If it's a low speed, it's probably a mouse or some other
   1507 	 *    interactive device, so set the threshold low.
   1508 	 *  * If it's a high speed, trim the trigger level down to prevent
   1509 	 *    overflows.
   1510 	 *  * Otherwise set it a bit higher.
   1511 	 */
   1512 	if (sc->sc_type == COM_TYPE_HAYESP)
   1513 		sc->sc_fifo = FIFO_DMA_MODE | FIFO_ENABLE | FIFO_TRIGGER_8;
   1514 	else if (ISSET(sc->sc_hwflags, COM_HW_FIFO))
   1515 		sc->sc_fifo = FIFO_ENABLE |
   1516 		    (t->c_ospeed <= 1200 ? FIFO_TRIGGER_1 :
   1517 		     t->c_ospeed <= 38400 ? FIFO_TRIGGER_8 : FIFO_TRIGGER_4);
   1518 	else
   1519 		sc->sc_fifo = 0;
   1520 
   1521 	/* And copy to tty. */
   1522 	tp->t_ispeed = 0;
   1523 	tp->t_ospeed = t->c_ospeed;
   1524 	tp->t_cflag = t->c_cflag;
   1525 
   1526 	if (!sc->sc_heldchange) {
   1527 		if (sc->sc_tx_busy) {
   1528 			sc->sc_heldtbc = sc->sc_tbc;
   1529 			sc->sc_tbc = 0;
   1530 			sc->sc_heldchange = 1;
   1531 		} else
   1532 			com_loadchannelregs(sc);
   1533 	}
   1534 
   1535 	if (!ISSET(t->c_cflag, CHWFLOW)) {
   1536 		/* Disable the high water mark. */
   1537 		sc->sc_r_hiwat = 0;
   1538 		sc->sc_r_lowat = 0;
   1539 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
   1540 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
   1541 			com_schedrx(sc);
   1542 		}
   1543 		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED)) {
   1544 			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED);
   1545 			com_hwiflow(sc);
   1546 		}
   1547 	} else {
   1548 		sc->sc_r_hiwat = com_rbuf_hiwat;
   1549 		sc->sc_r_lowat = com_rbuf_lowat;
   1550 	}
   1551 
   1552 	COM_UNLOCK(sc);
   1553 	splx(s);
   1554 
   1555 	/*
   1556 	 * Update the tty layer's idea of the carrier bit, in case we changed
   1557 	 * CLOCAL or MDMBUF.  We don't hang up here; we only do that by
   1558 	 * explicit request.
   1559 	 */
   1560 	(void) (*tp->t_linesw->l_modem)(tp, ISSET(sc->sc_msr, MSR_DCD));
   1561 
   1562 #ifdef COM_DEBUG
   1563 	if (com_debug)
   1564 		comstatus(sc, "comparam ");
   1565 #endif
   1566 
   1567 	if (!ISSET(t->c_cflag, CHWFLOW)) {
   1568 		if (sc->sc_tx_stopped) {
   1569 			sc->sc_tx_stopped = 0;
   1570 			comstart(tp);
   1571 		}
   1572 	}
   1573 
   1574 	return (0);
   1575 }
   1576 
   1577 void
   1578 com_iflush(struct com_softc *sc)
   1579 {
   1580 	bus_space_tag_t iot = sc->sc_iot;
   1581 	bus_space_handle_t ioh = sc->sc_ioh;
   1582 #ifdef DIAGNOSTIC
   1583 	int reg;
   1584 #endif
   1585 	int timo;
   1586 
   1587 #ifdef DIAGNOSTIC
   1588 	reg = 0xffff;
   1589 #endif
   1590 	timo = 50000;
   1591 	/* flush any pending I/O */
   1592 	while (ISSET(bus_space_read_1(iot, ioh, com_lsr), LSR_RXRDY)
   1593 	    && --timo)
   1594 #ifdef DIAGNOSTIC
   1595 		reg =
   1596 #else
   1597 		    (void)
   1598 #endif
   1599 		    bus_space_read_1(iot, ioh, com_data);
   1600 #ifdef DIAGNOSTIC
   1601 	if (!timo)
   1602 		printf("%s: com_iflush timeout %02x\n", sc->sc_dev.dv_xname,
   1603 		       reg);
   1604 #endif
   1605 }
   1606 
   1607 void
   1608 com_loadchannelregs(struct com_softc *sc)
   1609 {
   1610 	bus_space_tag_t iot = sc->sc_iot;
   1611 	bus_space_handle_t ioh = sc->sc_ioh;
   1612 
   1613 	/* XXXXX necessary? */
   1614 	com_iflush(sc);
   1615 
   1616 #ifdef COM_PXA2X0
   1617 	if (sc->sc_type == COM_TYPE_PXA2x0)
   1618 		bus_space_write_1(iot, ioh, com_ier, IER_EUART);
   1619 	else
   1620 #endif
   1621 		bus_space_write_1(iot, ioh, com_ier, 0);
   1622 
   1623 	if (ISSET(sc->sc_hwflags, COM_HW_FLOW)) {
   1624 		bus_space_write_1(iot, ioh, com_lcr, LCR_EERS);
   1625 		bus_space_write_1(iot, ioh, com_efr, sc->sc_efr);
   1626 	}
   1627 	bus_space_write_1(iot, ioh, com_lcr, sc->sc_lcr | LCR_DLAB);
   1628 	bus_space_write_1(iot, ioh, com_dlbl, sc->sc_dlbl);
   1629 	bus_space_write_1(iot, ioh, com_dlbh, sc->sc_dlbh);
   1630 	bus_space_write_1(iot, ioh, com_lcr, sc->sc_lcr);
   1631 	bus_space_write_1(iot, ioh, com_mcr, sc->sc_mcr_active = sc->sc_mcr);
   1632 	bus_space_write_1(iot, ioh, com_fifo, sc->sc_fifo);
   1633 #ifdef COM_HAYESP
   1634 	if (sc->sc_type == COM_TYPE_HAYESP) {
   1635 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD1,
   1636 		    HAYESP_SETPRESCALER);
   1637 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
   1638 		    sc->sc_prescaler);
   1639 	}
   1640 #endif
   1641 
   1642 	bus_space_write_1(iot, ioh, com_ier, sc->sc_ier);
   1643 }
   1644 
   1645 int
   1646 comhwiflow(struct tty *tp, int block)
   1647 {
   1648 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(tp->t_dev));
   1649 	int s;
   1650 
   1651 	if (COM_ISALIVE(sc) == 0)
   1652 		return (0);
   1653 
   1654 	if (sc->sc_mcr_rts == 0)
   1655 		return (0);
   1656 
   1657 	s = splserial();
   1658 	COM_LOCK(sc);
   1659 
   1660 	if (block) {
   1661 		if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
   1662 			SET(sc->sc_rx_flags, RX_TTY_BLOCKED);
   1663 			com_hwiflow(sc);
   1664 		}
   1665 	} else {
   1666 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
   1667 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
   1668 			com_schedrx(sc);
   1669 		}
   1670 		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
   1671 			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED);
   1672 			com_hwiflow(sc);
   1673 		}
   1674 	}
   1675 
   1676 	COM_UNLOCK(sc);
   1677 	splx(s);
   1678 	return (1);
   1679 }
   1680 
   1681 /*
   1682  * (un)block input via hw flowcontrol
   1683  */
   1684 void
   1685 com_hwiflow(struct com_softc *sc)
   1686 {
   1687 	bus_space_tag_t iot = sc->sc_iot;
   1688 	bus_space_handle_t ioh = sc->sc_ioh;
   1689 
   1690 	if (sc->sc_mcr_rts == 0)
   1691 		return;
   1692 
   1693 	if (ISSET(sc->sc_rx_flags, RX_ANY_BLOCK)) {
   1694 		CLR(sc->sc_mcr, sc->sc_mcr_rts);
   1695 		CLR(sc->sc_mcr_active, sc->sc_mcr_rts);
   1696 	} else {
   1697 		SET(sc->sc_mcr, sc->sc_mcr_rts);
   1698 		SET(sc->sc_mcr_active, sc->sc_mcr_rts);
   1699 	}
   1700 	bus_space_write_1(iot, ioh, com_mcr, sc->sc_mcr_active);
   1701 }
   1702 
   1703 
   1704 void
   1705 comstart(struct tty *tp)
   1706 {
   1707 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(tp->t_dev));
   1708 	bus_space_tag_t iot = sc->sc_iot;
   1709 	bus_space_handle_t ioh = sc->sc_ioh;
   1710 	int s;
   1711 
   1712 	if (COM_ISALIVE(sc) == 0)
   1713 		return;
   1714 
   1715 	s = spltty();
   1716 	if (ISSET(tp->t_state, TS_BUSY | TS_TIMEOUT | TS_TTSTOP))
   1717 		goto out;
   1718 	if (sc->sc_tx_stopped)
   1719 		goto out;
   1720 
   1721 	if (tp->t_outq.c_cc <= tp->t_lowat) {
   1722 		if (ISSET(tp->t_state, TS_ASLEEP)) {
   1723 			CLR(tp->t_state, TS_ASLEEP);
   1724 			wakeup(&tp->t_outq);
   1725 		}
   1726 		selwakeup(&tp->t_wsel);
   1727 		if (tp->t_outq.c_cc == 0)
   1728 			goto out;
   1729 	}
   1730 
   1731 	/* Grab the first contiguous region of buffer space. */
   1732 	{
   1733 		u_char *tba;
   1734 		int tbc;
   1735 
   1736 		tba = tp->t_outq.c_cf;
   1737 		tbc = ndqb(&tp->t_outq, 0);
   1738 
   1739 		(void)splserial();
   1740 		COM_LOCK(sc);
   1741 
   1742 		sc->sc_tba = tba;
   1743 		sc->sc_tbc = tbc;
   1744 	}
   1745 
   1746 	SET(tp->t_state, TS_BUSY);
   1747 	sc->sc_tx_busy = 1;
   1748 
   1749 	/* Enable transmit completion interrupts if necessary. */
   1750 	if (!ISSET(sc->sc_ier, IER_ETXRDY)) {
   1751 		SET(sc->sc_ier, IER_ETXRDY);
   1752 		bus_space_write_1(iot, ioh, com_ier, sc->sc_ier);
   1753 	}
   1754 
   1755 	/* Output the first chunk of the contiguous buffer. */
   1756 	if (!ISSET(sc->sc_hwflags, COM_HW_NO_TXPRELOAD)) {
   1757 		u_int n;
   1758 
   1759 		n = sc->sc_tbc;
   1760 		if (n > sc->sc_fifolen)
   1761 			n = sc->sc_fifolen;
   1762 		bus_space_write_multi_1(iot, ioh, com_data, sc->sc_tba, n);
   1763 		sc->sc_tbc -= n;
   1764 		sc->sc_tba += n;
   1765 	}
   1766 	COM_UNLOCK(sc);
   1767 out:
   1768 	splx(s);
   1769 	return;
   1770 }
   1771 
   1772 /*
   1773  * Stop output on a line.
   1774  */
   1775 void
   1776 comstop(struct tty *tp, int flag)
   1777 {
   1778 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(tp->t_dev));
   1779 	int s;
   1780 
   1781 	s = splserial();
   1782 	COM_LOCK(sc);
   1783 	if (ISSET(tp->t_state, TS_BUSY)) {
   1784 		/* Stop transmitting at the next chunk. */
   1785 		sc->sc_tbc = 0;
   1786 		sc->sc_heldtbc = 0;
   1787 		if (!ISSET(tp->t_state, TS_TTSTOP))
   1788 			SET(tp->t_state, TS_FLUSH);
   1789 	}
   1790 	COM_UNLOCK(sc);
   1791 	splx(s);
   1792 }
   1793 
   1794 void
   1795 comdiag(void *arg)
   1796 {
   1797 	struct com_softc *sc = arg;
   1798 	int overflows, floods;
   1799 	int s;
   1800 
   1801 	s = splserial();
   1802 	COM_LOCK(sc);
   1803 	overflows = sc->sc_overflows;
   1804 	sc->sc_overflows = 0;
   1805 	floods = sc->sc_floods;
   1806 	sc->sc_floods = 0;
   1807 	sc->sc_errors = 0;
   1808 	COM_UNLOCK(sc);
   1809 	splx(s);
   1810 
   1811 	log(LOG_WARNING, "%s: %d silo overflow%s, %d ibuf flood%s\n",
   1812 	    sc->sc_dev.dv_xname,
   1813 	    overflows, overflows == 1 ? "" : "s",
   1814 	    floods, floods == 1 ? "" : "s");
   1815 }
   1816 
   1817 integrate void
   1818 com_rxsoft(struct com_softc *sc, struct tty *tp)
   1819 {
   1820 	int (*rint)(int, struct tty *) = tp->t_linesw->l_rint;
   1821 	u_char *get, *end;
   1822 	u_int cc, scc;
   1823 	u_char lsr;
   1824 	int code;
   1825 	int s;
   1826 
   1827 	end = sc->sc_ebuf;
   1828 	get = sc->sc_rbget;
   1829 	scc = cc = com_rbuf_size - sc->sc_rbavail;
   1830 
   1831 	if (cc == com_rbuf_size) {
   1832 		sc->sc_floods++;
   1833 		if (sc->sc_errors++ == 0)
   1834 			callout_reset(&sc->sc_diag_callout, 60 * hz,
   1835 			    comdiag, sc);
   1836 	}
   1837 
   1838 	/* If not yet open, drop the entire buffer content here */
   1839 	if (!ISSET(tp->t_state, TS_ISOPEN)) {
   1840 		get += cc << 1;
   1841 		if (get >= end)
   1842 			get -= com_rbuf_size << 1;
   1843 		cc = 0;
   1844 	}
   1845 	while (cc) {
   1846 		code = get[0];
   1847 		lsr = get[1];
   1848 		if (ISSET(lsr, LSR_OE | LSR_BI | LSR_FE | LSR_PE)) {
   1849 			if (ISSET(lsr, LSR_OE)) {
   1850 				sc->sc_overflows++;
   1851 				if (sc->sc_errors++ == 0)
   1852 					callout_reset(&sc->sc_diag_callout,
   1853 					    60 * hz, comdiag, sc);
   1854 			}
   1855 			if (ISSET(lsr, LSR_BI | LSR_FE))
   1856 				SET(code, TTY_FE);
   1857 			if (ISSET(lsr, LSR_PE))
   1858 				SET(code, TTY_PE);
   1859 		}
   1860 		if ((*rint)(code, tp) == -1) {
   1861 			/*
   1862 			 * The line discipline's buffer is out of space.
   1863 			 */
   1864 			if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
   1865 				/*
   1866 				 * We're either not using flow control, or the
   1867 				 * line discipline didn't tell us to block for
   1868 				 * some reason.  Either way, we have no way to
   1869 				 * know when there's more space available, so
   1870 				 * just drop the rest of the data.
   1871 				 */
   1872 				get += cc << 1;
   1873 				if (get >= end)
   1874 					get -= com_rbuf_size << 1;
   1875 				cc = 0;
   1876 			} else {
   1877 				/*
   1878 				 * Don't schedule any more receive processing
   1879 				 * until the line discipline tells us there's
   1880 				 * space available (through comhwiflow()).
   1881 				 * Leave the rest of the data in the input
   1882 				 * buffer.
   1883 				 */
   1884 				SET(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
   1885 			}
   1886 			break;
   1887 		}
   1888 		get += 2;
   1889 		if (get >= end)
   1890 			get = sc->sc_rbuf;
   1891 		cc--;
   1892 	}
   1893 
   1894 	if (cc != scc) {
   1895 		sc->sc_rbget = get;
   1896 		s = splserial();
   1897 		COM_LOCK(sc);
   1898 
   1899 		cc = sc->sc_rbavail += scc - cc;
   1900 		/* Buffers should be ok again, release possible block. */
   1901 		if (cc >= sc->sc_r_lowat) {
   1902 			if (ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
   1903 				CLR(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
   1904 				SET(sc->sc_ier, IER_ERXRDY);
   1905 #ifdef COM_PXA2X0
   1906 				if (sc->sc_type == COM_TYPE_PXA2x0)
   1907 					SET(sc->sc_ier, IER_ERXTOUT);
   1908 #endif
   1909 				bus_space_write_1(sc->sc_iot, sc->sc_ioh,
   1910 				    com_ier, sc->sc_ier);
   1911 			}
   1912 			if (ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED)) {
   1913 				CLR(sc->sc_rx_flags, RX_IBUF_BLOCKED);
   1914 				com_hwiflow(sc);
   1915 			}
   1916 		}
   1917 		COM_UNLOCK(sc);
   1918 		splx(s);
   1919 	}
   1920 }
   1921 
   1922 integrate void
   1923 com_txsoft(struct com_softc *sc, struct tty *tp)
   1924 {
   1925 
   1926 	CLR(tp->t_state, TS_BUSY);
   1927 	if (ISSET(tp->t_state, TS_FLUSH))
   1928 		CLR(tp->t_state, TS_FLUSH);
   1929 	else
   1930 		ndflush(&tp->t_outq, (int)(sc->sc_tba - tp->t_outq.c_cf));
   1931 	(*tp->t_linesw->l_start)(tp);
   1932 }
   1933 
   1934 integrate void
   1935 com_stsoft(struct com_softc *sc, struct tty *tp)
   1936 {
   1937 	u_char msr, delta;
   1938 	int s;
   1939 
   1940 	s = splserial();
   1941 	COM_LOCK(sc);
   1942 	msr = sc->sc_msr;
   1943 	delta = sc->sc_msr_delta;
   1944 	sc->sc_msr_delta = 0;
   1945 	COM_UNLOCK(sc);
   1946 	splx(s);
   1947 
   1948 	if (ISSET(delta, sc->sc_msr_dcd)) {
   1949 		/*
   1950 		 * Inform the tty layer that carrier detect changed.
   1951 		 */
   1952 		(void) (*tp->t_linesw->l_modem)(tp, ISSET(msr, MSR_DCD));
   1953 	}
   1954 
   1955 	if (ISSET(delta, sc->sc_msr_cts)) {
   1956 		/* Block or unblock output according to flow control. */
   1957 		if (ISSET(msr, sc->sc_msr_cts)) {
   1958 			sc->sc_tx_stopped = 0;
   1959 			(*tp->t_linesw->l_start)(tp);
   1960 		} else {
   1961 			sc->sc_tx_stopped = 1;
   1962 		}
   1963 	}
   1964 
   1965 #ifdef COM_DEBUG
   1966 	if (com_debug)
   1967 		comstatus(sc, "com_stsoft");
   1968 #endif
   1969 }
   1970 
   1971 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
   1972 void
   1973 comsoft(void *arg)
   1974 {
   1975 	struct com_softc *sc = arg;
   1976 	struct tty *tp;
   1977 
   1978 	if (COM_ISALIVE(sc) == 0)
   1979 		return;
   1980 
   1981 	{
   1982 #else
   1983 void
   1984 #ifndef __NO_SOFT_SERIAL_INTERRUPT
   1985 comsoft(void)
   1986 #else
   1987 comsoft(void *arg)
   1988 #endif
   1989 {
   1990 	struct com_softc	*sc;
   1991 	struct tty	*tp;
   1992 	int	unit;
   1993 #ifdef __NO_SOFT_SERIAL_INTERRUPT
   1994 	int s;
   1995 
   1996 	s = splsoftserial();
   1997 	com_softintr_scheduled = 0;
   1998 #endif
   1999 
   2000 	for (unit = 0; unit < com_cd.cd_ndevs; unit++) {
   2001 		sc = device_lookup(&com_cd, unit);
   2002 		if (sc == NULL || !ISSET(sc->sc_hwflags, COM_HW_DEV_OK))
   2003 			continue;
   2004 
   2005 		if (COM_ISALIVE(sc) == 0)
   2006 			continue;
   2007 
   2008 		tp = sc->sc_tty;
   2009 		if (tp == NULL)
   2010 			continue;
   2011 		if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0)
   2012 			continue;
   2013 #endif
   2014 		tp = sc->sc_tty;
   2015 
   2016 		if (sc->sc_rx_ready) {
   2017 			sc->sc_rx_ready = 0;
   2018 			com_rxsoft(sc, tp);
   2019 		}
   2020 
   2021 		if (sc->sc_st_check) {
   2022 			sc->sc_st_check = 0;
   2023 			com_stsoft(sc, tp);
   2024 		}
   2025 
   2026 		if (sc->sc_tx_done) {
   2027 			sc->sc_tx_done = 0;
   2028 			com_txsoft(sc, tp);
   2029 		}
   2030 	}
   2031 
   2032 #ifndef __HAVE_GENERIC_SOFT_INTERRUPTS
   2033 #ifdef __NO_SOFT_SERIAL_INTERRUPT
   2034 	splx(s);
   2035 #endif
   2036 #endif
   2037 }
   2038 
   2039 #ifdef __ALIGN_BRACKET_LEVEL_FOR_CTAGS
   2040 	/* there has got to be a better way to do comsoft() */
   2041 }}
   2042 #endif
   2043 
   2044 int
   2045 comintr(void *arg)
   2046 {
   2047 	struct com_softc *sc = arg;
   2048 	bus_space_tag_t iot = sc->sc_iot;
   2049 	bus_space_handle_t ioh = sc->sc_ioh;
   2050 	u_char *put, *end;
   2051 	u_int cc;
   2052 	u_char lsr, iir;
   2053 
   2054 	if (COM_ISALIVE(sc) == 0)
   2055 		return (0);
   2056 
   2057 	COM_LOCK(sc);
   2058 	iir = bus_space_read_1(iot, ioh, com_iir);
   2059 	if (ISSET(iir, IIR_NOPEND)) {
   2060 		COM_UNLOCK(sc);
   2061 		return (0);
   2062 	}
   2063 
   2064 	end = sc->sc_ebuf;
   2065 	put = sc->sc_rbput;
   2066 	cc = sc->sc_rbavail;
   2067 
   2068 again:	do {
   2069 		u_char	msr, delta;
   2070 
   2071 		lsr = bus_space_read_1(iot, ioh, com_lsr);
   2072 		if (ISSET(lsr, LSR_BI)) {
   2073 			int cn_trapped = 0;
   2074 
   2075 			cn_check_magic(sc->sc_tty->t_dev,
   2076 				       CNC_BREAK, com_cnm_state);
   2077 			if (cn_trapped)
   2078 				continue;
   2079 #if defined(KGDB) && !defined(DDB)
   2080 			if (ISSET(sc->sc_hwflags, COM_HW_KGDB)) {
   2081 				kgdb_connect(1);
   2082 				continue;
   2083 			}
   2084 #endif
   2085 		}
   2086 
   2087 		if (ISSET(lsr, LSR_RCV_MASK) &&
   2088 		    !ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
   2089 			while (cc > 0) {
   2090 				int cn_trapped = 0;
   2091 				put[0] = bus_space_read_1(iot, ioh, com_data);
   2092 				put[1] = lsr;
   2093 				cn_check_magic(sc->sc_tty->t_dev,
   2094 					       put[0], com_cnm_state);
   2095 				if (cn_trapped) {
   2096 					lsr = bus_space_read_1(iot, ioh, com_lsr);
   2097 					if (!ISSET(lsr, LSR_RCV_MASK))
   2098 						break;
   2099 
   2100 					continue;
   2101 				}
   2102 				put += 2;
   2103 				if (put >= end)
   2104 					put = sc->sc_rbuf;
   2105 				cc--;
   2106 
   2107 				lsr = bus_space_read_1(iot, ioh, com_lsr);
   2108 				if (!ISSET(lsr, LSR_RCV_MASK))
   2109 					break;
   2110 			}
   2111 
   2112 			/*
   2113 			 * Current string of incoming characters ended because
   2114 			 * no more data was available or we ran out of space.
   2115 			 * Schedule a receive event if any data was received.
   2116 			 * If we're out of space, turn off receive interrupts.
   2117 			 */
   2118 			sc->sc_rbput = put;
   2119 			sc->sc_rbavail = cc;
   2120 			if (!ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED))
   2121 				sc->sc_rx_ready = 1;
   2122 
   2123 			/*
   2124 			 * See if we are in danger of overflowing a buffer. If
   2125 			 * so, use hardware flow control to ease the pressure.
   2126 			 */
   2127 			if (!ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED) &&
   2128 			    cc < sc->sc_r_hiwat) {
   2129 				SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
   2130 				com_hwiflow(sc);
   2131 			}
   2132 
   2133 			/*
   2134 			 * If we're out of space, disable receive interrupts
   2135 			 * until the queue has drained a bit.
   2136 			 */
   2137 			if (!cc) {
   2138 				SET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
   2139 				CLR(sc->sc_ier, IER_ERXRDY);
   2140 #ifdef COM_PXA2X0
   2141 				if (sc->sc_type == COM_TYPE_PXA2x0)
   2142 					CLR(sc->sc_ier, IER_ERXTOUT);
   2143 #endif
   2144 				bus_space_write_1(iot, ioh, com_ier,
   2145 				    sc->sc_ier);
   2146 			}
   2147 		} else {
   2148 			if ((iir & IIR_IMASK) == IIR_RXRDY) {
   2149 #ifdef COM_PXA2X0
   2150 				if (sc->sc_type == COM_TYPE_PXA2x0)
   2151 					bus_space_write_1(iot, ioh, com_ier,
   2152 					    IER_EUART);
   2153 				else
   2154 #endif
   2155 					bus_space_write_1(iot, ioh, com_ier, 0);
   2156 				delay(10);
   2157 				bus_space_write_1(iot, ioh, com_ier,sc->sc_ier);
   2158 				continue;
   2159 			}
   2160 		}
   2161 
   2162 		msr = bus_space_read_1(iot, ioh, com_msr);
   2163 		delta = msr ^ sc->sc_msr;
   2164 		sc->sc_msr = msr;
   2165 		/*
   2166 		 * Pulse-per-second (PSS) signals on edge of DCD?
   2167 		 * Process these even if line discipline is ignoring DCD.
   2168 		 */
   2169 		if (delta & sc->sc_ppsmask) {
   2170 			struct timeval tv;
   2171 		    	if ((msr & sc->sc_ppsmask) == sc->sc_ppsassert) {
   2172 				/* XXX nanotime() */
   2173 				microtime(&tv);
   2174 				TIMEVAL_TO_TIMESPEC(&tv,
   2175 				    &sc->ppsinfo.assert_timestamp);
   2176 				if (sc->ppsparam.mode & PPS_OFFSETASSERT) {
   2177 					timespecadd(&sc->ppsinfo.assert_timestamp,
   2178 					    &sc->ppsparam.assert_offset,
   2179 						    &sc->ppsinfo.assert_timestamp);
   2180 				}
   2181 
   2182 #ifdef PPS_SYNC
   2183 				if (pps_kc_hardpps_source == sc &&
   2184 				    pps_kc_hardpps_mode & PPS_CAPTUREASSERT) {
   2185 					hardpps(&tv, tv.tv_usec);
   2186 				}
   2187 #endif
   2188 				sc->ppsinfo.assert_sequence++;
   2189 				sc->ppsinfo.current_mode = sc->ppsparam.mode;
   2190 
   2191 			} else if ((msr & sc->sc_ppsmask) == sc->sc_ppsclear) {
   2192 				/* XXX nanotime() */
   2193 				microtime(&tv);
   2194 				TIMEVAL_TO_TIMESPEC(&tv,
   2195 				    &sc->ppsinfo.clear_timestamp);
   2196 				if (sc->ppsparam.mode & PPS_OFFSETCLEAR) {
   2197 					timespecadd(&sc->ppsinfo.clear_timestamp,
   2198 					    &sc->ppsparam.clear_offset,
   2199 					    &sc->ppsinfo.clear_timestamp);
   2200 				}
   2201 
   2202 #ifdef PPS_SYNC
   2203 				if (pps_kc_hardpps_source == sc &&
   2204 				    pps_kc_hardpps_mode & PPS_CAPTURECLEAR) {
   2205 					hardpps(&tv, tv.tv_usec);
   2206 				}
   2207 #endif
   2208 				sc->ppsinfo.clear_sequence++;
   2209 				sc->ppsinfo.current_mode = sc->ppsparam.mode;
   2210 			}
   2211 		}
   2212 
   2213 		/*
   2214 		 * Process normal status changes
   2215 		 */
   2216 		if (ISSET(delta, sc->sc_msr_mask)) {
   2217 			SET(sc->sc_msr_delta, delta);
   2218 
   2219 			/*
   2220 			 * Stop output immediately if we lose the output
   2221 			 * flow control signal or carrier detect.
   2222 			 */
   2223 			if (ISSET(~msr, sc->sc_msr_mask)) {
   2224 				sc->sc_tbc = 0;
   2225 				sc->sc_heldtbc = 0;
   2226 #ifdef COM_DEBUG
   2227 				if (com_debug)
   2228 					comstatus(sc, "comintr  ");
   2229 #endif
   2230 			}
   2231 
   2232 			sc->sc_st_check = 1;
   2233 		}
   2234 	} while (!ISSET((iir =
   2235 	    bus_space_read_1(iot, ioh, com_iir)), IIR_NOPEND) &&
   2236 	    /*
   2237 	     * Since some device (e.g., ST16C1550) doesn't clear IIR_TXRDY
   2238 	     * by IIR read, so we can't do this way: `process all interrupts,
   2239 	     * then do TX if possble'.
   2240 	     */
   2241 	    (iir & IIR_IMASK) != IIR_TXRDY);
   2242 
   2243 	/*
   2244 	 * Read LSR again, since there may be an interrupt between
   2245 	 * the last LSR read and IIR read above.
   2246 	 */
   2247 	lsr = bus_space_read_1(iot, ioh, com_lsr);
   2248 
   2249 	/*
   2250 	 * See if data can be transmitted as well.
   2251 	 * Schedule tx done event if no data left
   2252 	 * and tty was marked busy.
   2253 	 */
   2254 	if (ISSET(lsr, LSR_TXRDY)) {
   2255 		/*
   2256 		 * If we've delayed a parameter change, do it now, and restart
   2257 		 * output.
   2258 		 */
   2259 		if (sc->sc_heldchange) {
   2260 			com_loadchannelregs(sc);
   2261 			sc->sc_heldchange = 0;
   2262 			sc->sc_tbc = sc->sc_heldtbc;
   2263 			sc->sc_heldtbc = 0;
   2264 		}
   2265 
   2266 		/* Output the next chunk of the contiguous buffer, if any. */
   2267 		if (sc->sc_tbc > 0) {
   2268 			u_int n;
   2269 
   2270 			n = sc->sc_tbc;
   2271 			if (n > sc->sc_fifolen)
   2272 				n = sc->sc_fifolen;
   2273 			bus_space_write_multi_1(iot, ioh, com_data, sc->sc_tba, n);
   2274 			sc->sc_tbc -= n;
   2275 			sc->sc_tba += n;
   2276 		} else {
   2277 			/* Disable transmit completion interrupts if necessary. */
   2278 			if (ISSET(sc->sc_ier, IER_ETXRDY)) {
   2279 				CLR(sc->sc_ier, IER_ETXRDY);
   2280 				bus_space_write_1(iot, ioh, com_ier, sc->sc_ier);
   2281 			}
   2282 			if (sc->sc_tx_busy) {
   2283 				sc->sc_tx_busy = 0;
   2284 				sc->sc_tx_done = 1;
   2285 			}
   2286 		}
   2287 	}
   2288 
   2289 	if (!ISSET((iir = bus_space_read_1(iot, ioh, com_iir)), IIR_NOPEND))
   2290 		goto again;
   2291 
   2292 	COM_UNLOCK(sc);
   2293 
   2294 	/* Wake up the poller. */
   2295 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
   2296 	softintr_schedule(sc->sc_si);
   2297 #else
   2298 #ifndef __NO_SOFT_SERIAL_INTERRUPT
   2299 	setsoftserial();
   2300 #else
   2301 	if (!com_softintr_scheduled) {
   2302 		com_softintr_scheduled = 1;
   2303 		callout_reset(&comsoft_callout, 1, comsoft, NULL);
   2304 	}
   2305 #endif
   2306 #endif
   2307 
   2308 #if NRND > 0 && defined(RND_COM)
   2309 	rnd_add_uint32(&sc->rnd_source, iir | lsr);
   2310 #endif
   2311 
   2312 	return (1);
   2313 }
   2314 
   2315 /*
   2316  * The following functions are polled getc and putc routines, shared
   2317  * by the console and kgdb glue.
   2318  *
   2319  * The read-ahead code is so that you can detect pending in-band
   2320  * cn_magic in polled mode while doing output rather than having to
   2321  * wait until the kernel decides it needs input.
   2322  */
   2323 
   2324 #define MAX_READAHEAD	20
   2325 static int com_readahead[MAX_READAHEAD];
   2326 static int com_readaheadcount = 0;
   2327 
   2328 int
   2329 com_common_getc(dev_t dev, bus_space_tag_t iot, bus_space_handle_t ioh)
   2330 {
   2331 	int s = splserial();
   2332 	u_char stat, c;
   2333 
   2334 	/* got a character from reading things earlier */
   2335 	if (com_readaheadcount > 0) {
   2336 		int i;
   2337 
   2338 		c = com_readahead[0];
   2339 		for (i = 1; i < com_readaheadcount; i++) {
   2340 			com_readahead[i-1] = com_readahead[i];
   2341 		}
   2342 		com_readaheadcount--;
   2343 		splx(s);
   2344 		return (c);
   2345 	}
   2346 
   2347 	/* block until a character becomes available */
   2348 	while (!ISSET(stat = bus_space_read_1(iot, ioh, com_lsr), LSR_RXRDY))
   2349 		;
   2350 
   2351 	c = bus_space_read_1(iot, ioh, com_data);
   2352 	stat = bus_space_read_1(iot, ioh, com_iir);
   2353 	{
   2354 		int cn_trapped = 0; /* unused */
   2355 #ifdef DDB
   2356 		extern int db_active;
   2357 		if (!db_active)
   2358 #endif
   2359 			cn_check_magic(dev, c, com_cnm_state);
   2360 	}
   2361 	splx(s);
   2362 	return (c);
   2363 }
   2364 
   2365 void
   2366 com_common_putc(dev_t dev, bus_space_tag_t iot, bus_space_handle_t ioh, int c)
   2367 {
   2368 	int s = splserial();
   2369 	int cin, stat, timo;
   2370 
   2371 	if (com_readaheadcount < MAX_READAHEAD
   2372 	     && ISSET(stat = bus_space_read_1(iot, ioh, com_lsr), LSR_RXRDY)) {
   2373 		int cn_trapped = 0;
   2374 		cin = bus_space_read_1(iot, ioh, com_data);
   2375 		stat = bus_space_read_1(iot, ioh, com_iir);
   2376 		cn_check_magic(dev, cin, com_cnm_state);
   2377 		com_readahead[com_readaheadcount++] = cin;
   2378 	}
   2379 
   2380 	/* wait for any pending transmission to finish */
   2381 	timo = 150000;
   2382 	while (!ISSET(bus_space_read_1(iot, ioh, com_lsr), LSR_TXRDY) && --timo)
   2383 		continue;
   2384 
   2385 	bus_space_write_1(iot, ioh, com_data, c);
   2386 	COM_BARRIER(iot, ioh, BR | BW);
   2387 
   2388 	/* wait for this transmission to complete */
   2389 	timo = 1500000;
   2390 	while (!ISSET(bus_space_read_1(iot, ioh, com_lsr), LSR_TXRDY) && --timo)
   2391 		continue;
   2392 
   2393 	splx(s);
   2394 }
   2395 
   2396 /*
   2397  * Initialize UART for use as console or KGDB line.
   2398  */
   2399 int
   2400 cominit(bus_space_tag_t iot, bus_addr_t iobase, int rate, int frequency,
   2401     int type, tcflag_t cflag, bus_space_handle_t *iohp)
   2402 {
   2403 	bus_space_handle_t ioh;
   2404 
   2405 	if (bus_space_map(iot, iobase, COM_NPORTS, 0, &ioh))
   2406 		return (ENOMEM); /* ??? */
   2407 
   2408 	bus_space_write_1(iot, ioh, com_lcr, LCR_EERS);
   2409 	bus_space_write_1(iot, ioh, com_efr, 0);
   2410 	bus_space_write_1(iot, ioh, com_lcr, LCR_DLAB);
   2411 	rate = comspeed(rate, frequency, type);
   2412 	bus_space_write_1(iot, ioh, com_dlbl, rate);
   2413 	bus_space_write_1(iot, ioh, com_dlbh, rate >> 8);
   2414 	bus_space_write_1(iot, ioh, com_lcr, cflag2lcr(cflag));
   2415 	bus_space_write_1(iot, ioh, com_mcr, MCR_DTR | MCR_RTS);
   2416 	bus_space_write_1(iot, ioh, com_fifo,
   2417 	    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_1);
   2418 #ifdef COM_PXA2X0
   2419 	if (type == COM_TYPE_PXA2x0)
   2420 		bus_space_write_1(iot, ioh, com_ier, IER_EUART);
   2421 	else
   2422 #endif
   2423 		bus_space_write_1(iot, ioh, com_ier, 0);
   2424 
   2425 	*iohp = ioh;
   2426 	return (0);
   2427 }
   2428 
   2429 /*
   2430  * Following are all routines needed for COM to act as console
   2431  */
   2432 struct consdev comcons = {
   2433 	NULL, NULL, comcngetc, comcnputc, comcnpollc, NULL, NULL, NULL,
   2434 	NODEV, CN_NORMAL
   2435 };
   2436 
   2437 
   2438 int
   2439 comcnattach(bus_space_tag_t iot, bus_addr_t iobase, int rate, int frequency,
   2440     int type, tcflag_t cflag)
   2441 {
   2442 	int res;
   2443 
   2444 	res = cominit(iot, iobase, rate, frequency, type, cflag, &comconsioh);
   2445 	if (res)
   2446 		return (res);
   2447 
   2448 	cn_tab = &comcons;
   2449 	cn_init_magic(&com_cnm_state);
   2450 	cn_set_magic("\047\001"); /* default magic is BREAK */
   2451 
   2452 	comconstag = iot;
   2453 	comconsaddr = iobase;
   2454 	comconsrate = rate;
   2455 	comconscflag = cflag;
   2456 
   2457 	return (0);
   2458 }
   2459 
   2460 int
   2461 comcngetc(dev_t dev)
   2462 {
   2463 
   2464 	return (com_common_getc(dev, comconstag, comconsioh));
   2465 }
   2466 
   2467 /*
   2468  * Console kernel output character routine.
   2469  */
   2470 void
   2471 comcnputc(dev_t dev, int c)
   2472 {
   2473 
   2474 	com_common_putc(dev, comconstag, comconsioh, c);
   2475 }
   2476 
   2477 void
   2478 comcnpollc(dev_t dev, int on)
   2479 {
   2480 
   2481 }
   2482 
   2483 #ifdef KGDB
   2484 int
   2485 com_kgdb_attach(bus_space_tag_t iot, bus_addr_t iobase, int rate,
   2486     int frequency, int type, tcflag_t cflag)
   2487 {
   2488 	int res;
   2489 
   2490 	if (iot == comconstag && iobase == comconsaddr) {
   2491 #if !defined(DDB)
   2492 		return (EBUSY); /* cannot share with console */
   2493 #else
   2494 		com_kgdb_ioh = comconsioh;
   2495 #endif
   2496 	} else {
   2497 		res = cominit(iot, iobase, rate, frequency, type, cflag,
   2498 			      &com_kgdb_ioh);
   2499 		if (res)
   2500 			return (res);
   2501 
   2502 		/*
   2503 		 * XXXfvdl this shouldn't be needed, but the cn_magic goo
   2504 		 * expects this to be initialized
   2505 		 */
   2506 		cn_init_magic(&com_cnm_state);
   2507 		cn_set_magic("\047\001");
   2508 	}
   2509 
   2510 	kgdb_attach(com_kgdb_getc, com_kgdb_putc, NULL);
   2511 	kgdb_dev = 123; /* unneeded, only to satisfy some tests */
   2512 
   2513 	com_kgdb_iot = iot;
   2514 	com_kgdb_addr = iobase;
   2515 
   2516 	return (0);
   2517 }
   2518 
   2519 /* ARGSUSED */
   2520 int
   2521 com_kgdb_getc(void *arg)
   2522 {
   2523 
   2524 	return (com_common_getc(NODEV, com_kgdb_iot, com_kgdb_ioh));
   2525 }
   2526 
   2527 /* ARGSUSED */
   2528 void
   2529 com_kgdb_putc(void *arg, int c)
   2530 {
   2531 
   2532 	com_common_putc(NODEV, com_kgdb_iot, com_kgdb_ioh, c);
   2533 }
   2534 #endif /* KGDB */
   2535 
   2536 /* helper function to identify the com ports used by
   2537  console or KGDB (and not yet autoconf attached) */
   2538 int
   2539 com_is_console(bus_space_tag_t iot, bus_addr_t iobase, bus_space_handle_t *ioh)
   2540 {
   2541 	bus_space_handle_t help;
   2542 
   2543 	if (!comconsattached &&
   2544 	    iot == comconstag && iobase == comconsaddr)
   2545 		help = comconsioh;
   2546 #ifdef KGDB
   2547 	else if (!com_kgdb_attached &&
   2548 	    iot == com_kgdb_iot && iobase == com_kgdb_addr)
   2549 		help = com_kgdb_ioh;
   2550 #endif
   2551 	else
   2552 		return (0);
   2553 
   2554 	if (ioh)
   2555 		*ioh = help;
   2556 	return (1);
   2557 }
   2558