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com.c revision 1.230
      1 /*	$NetBSD: com.c,v 1.230 2004/07/04 09:46:44 mycroft Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1998, 1999, 2004 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 1.230 2004/07/04 09:46:44 mycroft 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 /* The COM16650 option was renamed to COM_16650. */
     91 #ifdef COM16650
     92 #error Obsolete COM16650 option; use COM_16650 instead.
     93 #endif
     94 
     95 /*
     96  * Override cnmagic(9) macro before including <sys/systm.h>.
     97  * We need to know if cn_check_magic triggered debugger, so set a flag.
     98  * Callers of cn_check_magic must declare int cn_trapped = 0;
     99  * XXX: this is *ugly*!
    100  */
    101 #define cn_trap()				\
    102 	do {					\
    103 		console_debugger();		\
    104 		cn_trapped = 1;			\
    105 	} while (/* CONSTCOND */ 0)
    106 
    107 #include <sys/param.h>
    108 #include <sys/systm.h>
    109 #include <sys/ioctl.h>
    110 #include <sys/select.h>
    111 #include <sys/tty.h>
    112 #include <sys/proc.h>
    113 #include <sys/user.h>
    114 #include <sys/conf.h>
    115 #include <sys/file.h>
    116 #include <sys/uio.h>
    117 #include <sys/kernel.h>
    118 #include <sys/syslog.h>
    119 #include <sys/device.h>
    120 #include <sys/malloc.h>
    121 #include <sys/timepps.h>
    122 #include <sys/vnode.h>
    123 
    124 #include <machine/intr.h>
    125 #include <machine/bus.h>
    126 
    127 #include <dev/ic/comreg.h>
    128 #include <dev/ic/comvar.h>
    129 #include <dev/ic/ns16550reg.h>
    130 #include <dev/ic/st16650reg.h>
    131 #ifdef COM_HAYESP
    132 #include <dev/ic/hayespreg.h>
    133 #endif
    134 #define	com_lcr	com_cfcr
    135 #include <dev/cons.h>
    136 
    137 #ifdef COM_HAYESP
    138 int comprobeHAYESP(bus_space_handle_t hayespioh, struct com_softc *sc);
    139 #endif
    140 
    141 static void com_enable_debugport(struct com_softc *);
    142 
    143 void	com_config(struct com_softc *);
    144 void	com_shutdown(struct com_softc *);
    145 int	comspeed(long, long, int);
    146 static	u_char	cflag2lcr(tcflag_t);
    147 int	comparam(struct tty *, struct termios *);
    148 void	comstart(struct tty *);
    149 int	comhwiflow(struct tty *, int);
    150 
    151 void	com_loadchannelregs(struct com_softc *);
    152 void	com_hwiflow(struct com_softc *);
    153 void	com_break(struct com_softc *, int);
    154 void	com_modem(struct com_softc *, int);
    155 void	tiocm_to_com(struct com_softc *, u_long, int);
    156 int	com_to_tiocm(struct com_softc *);
    157 void	com_iflush(struct com_softc *);
    158 
    159 int	com_common_getc(dev_t, bus_space_tag_t, bus_space_handle_t);
    160 void	com_common_putc(dev_t, bus_space_tag_t, bus_space_handle_t, int);
    161 
    162 int	cominit(bus_space_tag_t, bus_addr_t, int, int, int, tcflag_t,
    163 	    bus_space_handle_t *);
    164 
    165 int	comcngetc(dev_t);
    166 void	comcnputc(dev_t, int);
    167 void	comcnpollc(dev_t, int);
    168 
    169 #define	integrate	static inline
    170 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
    171 void 	comsoft(void *);
    172 #else
    173 #ifndef __NO_SOFT_SERIAL_INTERRUPT
    174 void 	comsoft(void);
    175 #else
    176 void 	comsoft(void *);
    177 static struct callout comsoft_callout = CALLOUT_INITIALIZER;
    178 #endif
    179 #endif
    180 integrate void com_rxsoft(struct com_softc *, struct tty *);
    181 integrate void com_txsoft(struct com_softc *, struct tty *);
    182 integrate void com_stsoft(struct com_softc *, struct tty *);
    183 integrate void com_schedrx(struct com_softc *);
    184 void	comdiag(void *);
    185 
    186 extern struct cfdriver com_cd;
    187 
    188 dev_type_open(comopen);
    189 dev_type_close(comclose);
    190 dev_type_read(comread);
    191 dev_type_write(comwrite);
    192 dev_type_ioctl(comioctl);
    193 dev_type_stop(comstop);
    194 dev_type_tty(comtty);
    195 dev_type_poll(compoll);
    196 
    197 const struct cdevsw com_cdevsw = {
    198 	comopen, comclose, comread, comwrite, comioctl,
    199 	comstop, comtty, compoll, nommap, ttykqfilter, D_TTY
    200 };
    201 
    202 /*
    203  * Make this an option variable one can patch.
    204  * But be warned:  this must be a power of 2!
    205  */
    206 u_int com_rbuf_size = COM_RING_SIZE;
    207 
    208 /* Stop input when 3/4 of the ring is full; restart when only 1/4 is full. */
    209 u_int com_rbuf_hiwat = (COM_RING_SIZE * 1) / 4;
    210 u_int com_rbuf_lowat = (COM_RING_SIZE * 3) / 4;
    211 
    212 static bus_addr_t	comconsaddr;
    213 static bus_space_tag_t comconstag;
    214 static bus_space_handle_t comconsioh;
    215 static int	comconsattached;
    216 static int comconsrate;
    217 static tcflag_t comconscflag;
    218 static struct cnm_state com_cnm_state;
    219 
    220 static int ppscap =
    221 	PPS_TSFMT_TSPEC |
    222 	PPS_CAPTUREASSERT |
    223 	PPS_CAPTURECLEAR |
    224 	PPS_OFFSETASSERT | PPS_OFFSETCLEAR;
    225 
    226 #ifndef __HAVE_GENERIC_SOFT_INTERRUPTS
    227 #ifdef __NO_SOFT_SERIAL_INTERRUPT
    228 volatile int	com_softintr_scheduled;
    229 #endif
    230 #endif
    231 
    232 #ifdef KGDB
    233 #include <sys/kgdb.h>
    234 
    235 static bus_addr_t com_kgdb_addr;
    236 static bus_space_tag_t com_kgdb_iot;
    237 static bus_space_handle_t com_kgdb_ioh;
    238 static int com_kgdb_attached;
    239 
    240 int	com_kgdb_getc(void *);
    241 void	com_kgdb_putc(void *, int);
    242 #endif /* KGDB */
    243 
    244 #define	COMUNIT_MASK	0x7ffff
    245 #define	COMDIALOUT_MASK	0x80000
    246 
    247 #define	COMUNIT(x)	(minor(x) & COMUNIT_MASK)
    248 #define	COMDIALOUT(x)	(minor(x) & COMDIALOUT_MASK)
    249 
    250 #define	COM_ISALIVE(sc)	((sc)->enabled != 0 && \
    251 			 ISSET((sc)->sc_dev.dv_flags, DVF_ACTIVE))
    252 
    253 #define	BR	BUS_SPACE_BARRIER_READ
    254 #define	BW	BUS_SPACE_BARRIER_WRITE
    255 #define COM_BARRIER(t, h, f) bus_space_barrier((t), (h), 0, COM_NPORTS, (f))
    256 
    257 #if (defined(MULTIPROCESSOR) || defined(LOCKDEBUG)) && defined(COM_MPLOCK)
    258 
    259 #define COM_LOCK(sc) simple_lock(&(sc)->sc_lock)
    260 #define COM_UNLOCK(sc) simple_unlock(&(sc)->sc_lock)
    261 
    262 #else
    263 
    264 #define COM_LOCK(sc)
    265 #define COM_UNLOCK(sc)
    266 
    267 #endif
    268 
    269 /*ARGSUSED*/
    270 int
    271 comspeed(long speed, long frequency, int type)
    272 {
    273 #define	divrnd(n, q)	(((n)*2/(q)+1)/2)	/* divide and round off */
    274 
    275 	int x, err;
    276 
    277 #if 0
    278 	if (speed == 0)
    279 		return (0);
    280 #endif
    281 	if (speed <= 0)
    282 		return (-1);
    283 	x = divrnd(frequency / 16, speed);
    284 	if (x <= 0)
    285 		return (-1);
    286 	err = divrnd(((quad_t)frequency) * 1000 / 16, speed * x) - 1000;
    287 	if (err < 0)
    288 		err = -err;
    289 	if (err > COM_TOLERANCE)
    290 		return (-1);
    291 	return (x);
    292 
    293 #undef	divrnd
    294 }
    295 
    296 #ifdef COM_DEBUG
    297 int	com_debug = 0;
    298 
    299 void comstatus(struct com_softc *, char *);
    300 void
    301 comstatus(struct com_softc *sc, char *str)
    302 {
    303 	struct tty *tp = sc->sc_tty;
    304 
    305 	printf("%s: %s %cclocal  %cdcd %cts_carr_on %cdtr %ctx_stopped\n",
    306 	    sc->sc_dev.dv_xname, str,
    307 	    ISSET(tp->t_cflag, CLOCAL) ? '+' : '-',
    308 	    ISSET(sc->sc_msr, MSR_DCD) ? '+' : '-',
    309 	    ISSET(tp->t_state, TS_CARR_ON) ? '+' : '-',
    310 	    ISSET(sc->sc_mcr, MCR_DTR) ? '+' : '-',
    311 	    sc->sc_tx_stopped ? '+' : '-');
    312 
    313 	printf("%s: %s %ccrtscts %ccts %cts_ttstop  %crts rx_flags=0x%x\n",
    314 	    sc->sc_dev.dv_xname, str,
    315 	    ISSET(tp->t_cflag, CRTSCTS) ? '+' : '-',
    316 	    ISSET(sc->sc_msr, MSR_CTS) ? '+' : '-',
    317 	    ISSET(tp->t_state, TS_TTSTOP) ? '+' : '-',
    318 	    ISSET(sc->sc_mcr, MCR_RTS) ? '+' : '-',
    319 	    sc->sc_rx_flags);
    320 }
    321 #endif
    322 
    323 int
    324 comprobe1(bus_space_tag_t iot, bus_space_handle_t ioh)
    325 {
    326 
    327 	/* force access to id reg */
    328 	bus_space_write_1(iot, ioh, com_lcr, LCR_8BITS);
    329 	bus_space_write_1(iot, ioh, com_iir, 0);
    330 	if ((bus_space_read_1(iot, ioh, com_lcr) != LCR_8BITS) ||
    331 	    (bus_space_read_1(iot, ioh, com_iir) & 0x38))
    332 		return (0);
    333 
    334 	return (1);
    335 }
    336 
    337 #ifdef COM_HAYESP
    338 int
    339 comprobeHAYESP(bus_space_handle_t hayespioh, struct com_softc *sc)
    340 {
    341 	char	val, dips;
    342 	int	combaselist[] = { 0x3f8, 0x2f8, 0x3e8, 0x2e8 };
    343 	bus_space_tag_t iot = sc->sc_iot;
    344 
    345 	/*
    346 	 * Hayes ESP cards have two iobases.  One is for compatibility with
    347 	 * 16550 serial chips, and at the same ISA PC base addresses.  The
    348 	 * other is for ESP-specific enhanced features, and lies at a
    349 	 * different addressing range entirely (0x140, 0x180, 0x280, or 0x300).
    350 	 */
    351 
    352 	/* Test for ESP signature */
    353 	if ((bus_space_read_1(iot, hayespioh, 0) & 0xf3) == 0)
    354 		return (0);
    355 
    356 	/*
    357 	 * ESP is present at ESP enhanced base address; unknown com port
    358 	 */
    359 
    360 	/* Get the dip-switch configurations */
    361 	bus_space_write_1(iot, hayespioh, HAYESP_CMD1, HAYESP_GETDIPS);
    362 	dips = bus_space_read_1(iot, hayespioh, HAYESP_STATUS1);
    363 
    364 	/* Determine which com port this ESP card services: bits 0,1 of  */
    365 	/*  dips is the port # (0-3); combaselist[val] is the com_iobase */
    366 	if (sc->sc_iobase != combaselist[dips & 0x03])
    367 		return (0);
    368 
    369 	printf(": ESP");
    370 
    371  	/* Check ESP Self Test bits. */
    372 	/* Check for ESP version 2.0: bits 4,5,6 == 010 */
    373 	bus_space_write_1(iot, hayespioh, HAYESP_CMD1, HAYESP_GETTEST);
    374 	val = bus_space_read_1(iot, hayespioh, HAYESP_STATUS1); /* Clear reg1 */
    375 	val = bus_space_read_1(iot, hayespioh, HAYESP_STATUS2);
    376 	if ((val & 0x70) < 0x20) {
    377 		printf("-old (%o)", val & 0x70);
    378 		/* we do not support the necessary features */
    379 		return (0);
    380 	}
    381 
    382 	/* Check for ability to emulate 16550: bit 8 == 1 */
    383 	if ((dips & 0x80) == 0) {
    384 		printf(" slave");
    385 		/* XXX Does slave really mean no 16550 support?? */
    386 		return (0);
    387 	}
    388 
    389 	/*
    390 	 * If we made it this far, we are a full-featured ESP v2.0 (or
    391 	 * better), at the correct com port address.
    392 	 */
    393 
    394 	sc->sc_type = COM_TYPE_HAYESP;
    395 	printf(", 1024 byte fifo\n");
    396 	return (1);
    397 }
    398 #endif
    399 
    400 static void
    401 com_enable_debugport(struct com_softc *sc)
    402 {
    403 	int s;
    404 
    405 	/* Turn on line break interrupt, set carrier. */
    406 	s = splserial();
    407 	COM_LOCK(sc);
    408 	sc->sc_ier = IER_ERXRDY;
    409 #ifdef COM_PXA2X0
    410 	if (sc->sc_type == COM_TYPE_PXA2x0)
    411 		sc->sc_ier |= IER_EUART | IER_ERXTOUT;
    412 #endif
    413 	bus_space_write_1(sc->sc_iot, sc->sc_ioh, com_ier, sc->sc_ier);
    414 	SET(sc->sc_mcr, MCR_DTR | MCR_RTS);
    415 	bus_space_write_1(sc->sc_iot, sc->sc_ioh, com_mcr, sc->sc_mcr);
    416 	COM_UNLOCK(sc);
    417 	splx(s);
    418 }
    419 
    420 void
    421 com_attach_subr(struct com_softc *sc)
    422 {
    423 	bus_addr_t iobase = sc->sc_iobase;
    424 	bus_space_tag_t iot = sc->sc_iot;
    425 	bus_space_handle_t ioh = sc->sc_ioh;
    426 	struct tty *tp;
    427 #ifdef COM_16650
    428 	u_int8_t lcr;
    429 #endif
    430 #ifdef COM_HAYESP
    431 	int	hayesp_ports[] = { 0x140, 0x180, 0x280, 0x300, 0 };
    432 	int	*hayespp;
    433 #endif
    434 	const char *fifo_msg = NULL;
    435 
    436 	callout_init(&sc->sc_diag_callout);
    437 #if (defined(MULTIPROCESSOR) || defined(LOCKDEBUG)) && defined(COM_MPLOCK)
    438 	simple_lock_init(&sc->sc_lock);
    439 #endif
    440 
    441 	/* Disable interrupts before configuring the device. */
    442 #ifdef COM_PXA2X0
    443 	if (sc->sc_type == COM_TYPE_PXA2x0)
    444 		sc->sc_ier = IER_EUART;
    445 	else
    446 #endif
    447 		sc->sc_ier = 0;
    448 	bus_space_write_1(iot, ioh, com_ier, sc->sc_ier);
    449 
    450 	if (iot == comconstag && iobase == comconsaddr) {
    451 		comconsattached = 1;
    452 
    453 		/* Make sure the console is always "hardwired". */
    454 		delay(10000);			/* wait for output to finish */
    455 		SET(sc->sc_hwflags, COM_HW_CONSOLE);
    456 		SET(sc->sc_swflags, TIOCFLAG_SOFTCAR);
    457 	}
    458 
    459 #ifdef COM_HAYESP
    460 	sc->sc_prescaler = 0;			/* set prescaler to x1. */
    461 
    462 	/* Look for a Hayes ESP board. */
    463 	for (hayespp = hayesp_ports; *hayespp != 0; hayespp++) {
    464 		bus_space_handle_t hayespioh;
    465 
    466 #define	HAYESP_NPORTS	8			/* XXX XXX XXX ??? ??? ??? */
    467 		if (bus_space_map(iot, *hayespp, HAYESP_NPORTS, 0, &hayespioh))
    468 			continue;
    469 		if (comprobeHAYESP(hayespioh, sc)) {
    470 			sc->sc_hayespioh = hayespioh;
    471 			sc->sc_fifolen = 1024;
    472 
    473 			break;
    474 		}
    475 		bus_space_unmap(iot, hayespioh, HAYESP_NPORTS);
    476 	}
    477 	/* No ESP; look for other things. */
    478 	if (sc->sc_type != COM_TYPE_HAYESP) {
    479 #endif
    480 	sc->sc_fifolen = 1;
    481 	/* look for a NS 16550AF UART with FIFOs */
    482 	bus_space_write_1(iot, ioh, com_fifo,
    483 	    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_14);
    484 	delay(100);
    485 	if (ISSET(bus_space_read_1(iot, ioh, com_iir), IIR_FIFO_MASK)
    486 	    == IIR_FIFO_MASK)
    487 		if (ISSET(bus_space_read_1(iot, ioh, com_fifo), FIFO_TRIGGER_14)
    488 		    == FIFO_TRIGGER_14) {
    489 			SET(sc->sc_hwflags, COM_HW_FIFO);
    490 
    491 #ifdef COM_16650
    492 			/*
    493 			 * IIR changes into the EFR if LCR is set to LCR_EERS
    494 			 * on 16650s. We also know IIR != 0 at this point.
    495 			 * Write 0 into the EFR, and read it. If the result
    496 			 * is 0, we have a 16650.
    497 			 *
    498 			 * Older 16650s were broken; the test to detect them
    499 			 * is taken from the Linux driver. Apparently
    500 			 * setting DLAB enable gives access to the EFR on
    501 			 * these chips.
    502 			 */
    503 			lcr = bus_space_read_1(iot, ioh, com_lcr);
    504 			bus_space_write_1(iot, ioh, com_lcr, LCR_EERS);
    505 			bus_space_write_1(iot, ioh, com_efr, 0);
    506 			if (bus_space_read_1(iot, ioh, com_efr) == 0) {
    507 				bus_space_write_1(iot, ioh, com_lcr,
    508 				    lcr | LCR_DLAB);
    509 				if (bus_space_read_1(iot, ioh, com_efr) == 0) {
    510 					CLR(sc->sc_hwflags, COM_HW_FIFO);
    511 					sc->sc_fifolen = 0;
    512 				} else {
    513 					SET(sc->sc_hwflags, COM_HW_FLOW);
    514 					sc->sc_fifolen = 32;
    515 				}
    516 			} else
    517 #endif
    518 				sc->sc_fifolen = 16;
    519 
    520 #ifdef COM_16650
    521 			bus_space_write_1(iot, ioh, com_lcr, lcr);
    522 			if (sc->sc_fifolen == 0)
    523 				fifo_msg = "st16650, broken fifo";
    524 			else if (sc->sc_fifolen == 32)
    525 				fifo_msg = "st16650a, working fifo";
    526 			else
    527 #endif
    528 				fifo_msg = "ns16550a, working fifo";
    529 		} else
    530 			fifo_msg = "ns16550, broken fifo";
    531 	else
    532 		fifo_msg = "ns8250 or ns16450, no fifo";
    533 	bus_space_write_1(iot, ioh, com_fifo, 0);
    534 	/*
    535 	 * Some chips will clear down both Tx and Rx FIFOs when zero is
    536 	 * written to com_fifo. If this chip is the console, writing zero
    537 	 * results in some of the chip/FIFO description being lost, so delay
    538 	 * printing it until now.
    539 	 */
    540 	delay(10);
    541 	aprint_normal(": %s\n", fifo_msg);
    542 	if (ISSET(sc->sc_hwflags, COM_HW_TXFIFO_DISABLE)) {
    543 		sc->sc_fifolen = 1;
    544 		aprint_normal("%s: txfifo disabled\n", sc->sc_dev.dv_xname);
    545 	}
    546 #ifdef COM_HAYESP
    547 	}
    548 #endif
    549 
    550 	tp = ttymalloc();
    551 	tp->t_oproc = comstart;
    552 	tp->t_param = comparam;
    553 	tp->t_hwiflow = comhwiflow;
    554 
    555 	sc->sc_tty = tp;
    556 	sc->sc_rbuf = malloc(com_rbuf_size << 1, M_DEVBUF, M_NOWAIT);
    557 	sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
    558 	sc->sc_rbavail = com_rbuf_size;
    559 	if (sc->sc_rbuf == NULL) {
    560 		aprint_error("%s: unable to allocate ring buffer\n",
    561 		    sc->sc_dev.dv_xname);
    562 		return;
    563 	}
    564 	sc->sc_ebuf = sc->sc_rbuf + (com_rbuf_size << 1);
    565 
    566 	tty_attach(tp);
    567 
    568 	if (!ISSET(sc->sc_hwflags, COM_HW_NOIEN))
    569 		SET(sc->sc_mcr, MCR_IENABLE);
    570 
    571 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
    572 		int maj;
    573 
    574 		/* locate the major number */
    575 		maj = cdevsw_lookup_major(&com_cdevsw);
    576 
    577 		tp->t_dev = cn_tab->cn_dev = makedev(maj, sc->sc_dev.dv_unit);
    578 
    579 		aprint_normal("%s: console\n", sc->sc_dev.dv_xname);
    580 	}
    581 
    582 #ifdef KGDB
    583 	/*
    584 	 * Allow kgdb to "take over" this port.  If this is
    585 	 * not the console and is the kgdb device, it has
    586 	 * exclusive use.  If it's the console _and_ the
    587 	 * kgdb device, it doesn't.
    588 	 */
    589 	if (iot == com_kgdb_iot && iobase == com_kgdb_addr) {
    590 		if (!ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
    591 			com_kgdb_attached = 1;
    592 
    593 			SET(sc->sc_hwflags, COM_HW_KGDB);
    594 		}
    595 		aprint_normal("%s: kgdb\n", sc->sc_dev.dv_xname);
    596 	}
    597 #endif
    598 
    599 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
    600 	sc->sc_si = softintr_establish(IPL_SOFTSERIAL, comsoft, sc);
    601 #endif
    602 
    603 #if NRND > 0 && defined(RND_COM)
    604 	rnd_attach_source(&sc->rnd_source, sc->sc_dev.dv_xname,
    605 			  RND_TYPE_TTY, 0);
    606 #endif
    607 
    608 	/* if there are no enable/disable functions, assume the device
    609 	   is always enabled */
    610 	if (!sc->enable)
    611 		sc->enabled = 1;
    612 
    613 	com_config(sc);
    614 
    615 	SET(sc->sc_hwflags, COM_HW_DEV_OK);
    616 }
    617 
    618 void
    619 com_config(struct com_softc *sc)
    620 {
    621 	bus_space_tag_t iot = sc->sc_iot;
    622 	bus_space_handle_t ioh = sc->sc_ioh;
    623 
    624 	/* Disable interrupts before configuring the device. */
    625 #ifdef COM_PXA2X0
    626 	if (sc->sc_type == COM_TYPE_PXA2x0)
    627 		sc->sc_ier = IER_EUART;
    628 	else
    629 #endif
    630 		sc->sc_ier = 0;
    631 	bus_space_write_1(iot, ioh, com_ier, sc->sc_ier);
    632 
    633 #ifdef COM_HAYESP
    634 	/* Look for a Hayes ESP board. */
    635 	if (sc->sc_type == COM_TYPE_HAYESP) {
    636 		sc->sc_fifolen = 1024;
    637 
    638 		/* Set 16550 compatibility mode */
    639 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD1,
    640 				  HAYESP_SETMODE);
    641 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
    642 				  HAYESP_MODE_FIFO|HAYESP_MODE_RTS|
    643 				  HAYESP_MODE_SCALE);
    644 
    645 		/* Set RTS/CTS flow control */
    646 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD1,
    647 				  HAYESP_SETFLOWTYPE);
    648 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
    649 				  HAYESP_FLOW_RTS);
    650 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
    651 				  HAYESP_FLOW_CTS);
    652 
    653 		/* Set flow control levels */
    654 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD1,
    655 				  HAYESP_SETRXFLOW);
    656 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
    657 				  HAYESP_HIBYTE(HAYESP_RXHIWMARK));
    658 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
    659 				  HAYESP_LOBYTE(HAYESP_RXHIWMARK));
    660 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
    661 				  HAYESP_HIBYTE(HAYESP_RXLOWMARK));
    662 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
    663 				  HAYESP_LOBYTE(HAYESP_RXLOWMARK));
    664 	}
    665 #endif
    666 
    667 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE|COM_HW_KGDB))
    668 		com_enable_debugport(sc);
    669 }
    670 
    671 int
    672 com_detach(struct device *self, int flags)
    673 {
    674 	struct com_softc *sc = (struct com_softc *)self;
    675 	int maj, mn;
    676 
    677 	/* locate the major number */
    678 	maj = cdevsw_lookup_major(&com_cdevsw);
    679 
    680 	/* Nuke the vnodes for any open instances. */
    681 	mn = self->dv_unit;
    682 	vdevgone(maj, mn, mn, VCHR);
    683 
    684 	mn |= COMDIALOUT_MASK;
    685 	vdevgone(maj, mn, mn, VCHR);
    686 
    687 	if (sc->sc_rbuf == NULL) {
    688 		/*
    689 		 * Ring buffer allocation failed in the com_attach_subr,
    690 		 * only the tty is allocated, and nothing else.
    691 		 */
    692 		ttyfree(sc->sc_tty);
    693 		return 0;
    694 	}
    695 
    696 	/* Free the receive buffer. */
    697 	free(sc->sc_rbuf, M_DEVBUF);
    698 
    699 	/* Detach and free the tty. */
    700 	tty_detach(sc->sc_tty);
    701 	ttyfree(sc->sc_tty);
    702 
    703 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
    704 	/* Unhook the soft interrupt handler. */
    705 	softintr_disestablish(sc->sc_si);
    706 #endif
    707 
    708 #if NRND > 0 && defined(RND_COM)
    709 	/* Unhook the entropy source. */
    710 	rnd_detach_source(&sc->rnd_source);
    711 #endif
    712 
    713 	return (0);
    714 }
    715 
    716 int
    717 com_activate(struct device *self, enum devact act)
    718 {
    719 	struct com_softc *sc = (struct com_softc *)self;
    720 	int s, rv = 0;
    721 
    722 	s = splserial();
    723 	COM_LOCK(sc);
    724 	switch (act) {
    725 	case DVACT_ACTIVATE:
    726 		rv = EOPNOTSUPP;
    727 		break;
    728 
    729 	case DVACT_DEACTIVATE:
    730 		if (sc->sc_hwflags & (COM_HW_CONSOLE|COM_HW_KGDB)) {
    731 			rv = EBUSY;
    732 			break;
    733 		}
    734 
    735 		if (sc->disable != NULL && sc->enabled != 0) {
    736 			(*sc->disable)(sc);
    737 			sc->enabled = 0;
    738 		}
    739 		break;
    740 	}
    741 
    742 	COM_UNLOCK(sc);
    743 	splx(s);
    744 	return (rv);
    745 }
    746 
    747 void
    748 com_shutdown(struct com_softc *sc)
    749 {
    750 	struct tty *tp = sc->sc_tty;
    751 	int s;
    752 
    753 	s = splserial();
    754 	COM_LOCK(sc);
    755 
    756 	/* If we were asserting flow control, then deassert it. */
    757 	SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
    758 	com_hwiflow(sc);
    759 
    760 	/* Clear any break condition set with TIOCSBRK. */
    761 	com_break(sc, 0);
    762 
    763 	/* Turn off PPS capture on last close. */
    764 	sc->sc_ppsmask = 0;
    765 	sc->ppsparam.mode = 0;
    766 
    767 	/*
    768 	 * Hang up if necessary.  Wait a bit, so the other side has time to
    769 	 * notice even if we immediately open the port again.
    770 	 * Avoid tsleeping above splhigh().
    771 	 */
    772 	if (ISSET(tp->t_cflag, HUPCL)) {
    773 		com_modem(sc, 0);
    774 		COM_UNLOCK(sc);
    775 		splx(s);
    776 		/* XXX tsleep will only timeout */
    777 		(void) tsleep(sc, TTIPRI, ttclos, hz);
    778 		s = splserial();
    779 		COM_LOCK(sc);
    780 	}
    781 
    782 	/* Turn off interrupts. */
    783 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
    784 		sc->sc_ier = IER_ERXRDY; /* interrupt on break */
    785 #ifdef COM_PXA2X0
    786 		if (sc->sc_type == COM_TYPE_PXA2x0)
    787 			sc->sc_ier |= IER_ERXTOUT;
    788 #endif
    789 	} else
    790 		sc->sc_ier = 0;
    791 
    792 #ifdef COM_PXA2X0
    793 	if (sc->sc_type == COM_TYPE_PXA2x0)
    794 		sc->sc_ier |= IER_EUART;
    795 #endif
    796 
    797 	bus_space_write_1(sc->sc_iot, sc->sc_ioh, com_ier, sc->sc_ier);
    798 
    799 	if (sc->disable) {
    800 #ifdef DIAGNOSTIC
    801 		if (!sc->enabled)
    802 			panic("com_shutdown: not enabled?");
    803 #endif
    804 		(*sc->disable)(sc);
    805 		sc->enabled = 0;
    806 	}
    807 	COM_UNLOCK(sc);
    808 	splx(s);
    809 }
    810 
    811 int
    812 comopen(dev_t dev, int flag, int mode, struct proc *p)
    813 {
    814 	struct com_softc *sc;
    815 	struct tty *tp;
    816 	int s, s2;
    817 	int error;
    818 
    819 	sc = device_lookup(&com_cd, COMUNIT(dev));
    820 	if (sc == NULL || !ISSET(sc->sc_hwflags, COM_HW_DEV_OK) ||
    821 		sc->sc_rbuf == NULL)
    822 		return (ENXIO);
    823 
    824 	if (ISSET(sc->sc_dev.dv_flags, DVF_ACTIVE) == 0)
    825 		return (ENXIO);
    826 
    827 #ifdef KGDB
    828 	/*
    829 	 * If this is the kgdb port, no other use is permitted.
    830 	 */
    831 	if (ISSET(sc->sc_hwflags, COM_HW_KGDB))
    832 		return (EBUSY);
    833 #endif
    834 
    835 	tp = sc->sc_tty;
    836 
    837 	if (ISSET(tp->t_state, TS_ISOPEN) &&
    838 	    ISSET(tp->t_state, TS_XCLUDE) &&
    839 		p->p_ucred->cr_uid != 0)
    840 		return (EBUSY);
    841 
    842 	s = spltty();
    843 
    844 	/*
    845 	 * Do the following iff this is a first open.
    846 	 */
    847 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
    848 		struct termios t;
    849 
    850 		tp->t_dev = dev;
    851 
    852 		s2 = splserial();
    853 		COM_LOCK(sc);
    854 
    855 		if (sc->enable) {
    856 			if ((*sc->enable)(sc)) {
    857 				COM_UNLOCK(sc);
    858 				splx(s2);
    859 				splx(s);
    860 				printf("%s: device enable failed\n",
    861 				       sc->sc_dev.dv_xname);
    862 				return (EIO);
    863 			}
    864 			sc->enabled = 1;
    865 			com_config(sc);
    866 		}
    867 
    868 		/* Turn on interrupts. */
    869 		sc->sc_ier = IER_ERXRDY | IER_ERLS | IER_EMSC;
    870 #ifdef COM_PXA2X0
    871 		if (sc->sc_type == COM_TYPE_PXA2x0)
    872 			sc->sc_ier |= IER_EUART | IER_ERXTOUT;
    873 #endif
    874 		bus_space_write_1(sc->sc_iot, sc->sc_ioh, com_ier, sc->sc_ier);
    875 
    876 		/* Fetch the current modem control status, needed later. */
    877 		sc->sc_msr = bus_space_read_1(sc->sc_iot, sc->sc_ioh, com_msr);
    878 
    879 		/* Clear PPS capture state on first open. */
    880 		sc->sc_ppsmask = 0;
    881 		sc->ppsparam.mode = 0;
    882 
    883 		COM_UNLOCK(sc);
    884 		splx(s2);
    885 
    886 		/*
    887 		 * Initialize the termios status to the defaults.  Add in the
    888 		 * sticky bits from TIOCSFLAGS.
    889 		 */
    890 		t.c_ispeed = 0;
    891 		if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
    892 			t.c_ospeed = comconsrate;
    893 			t.c_cflag = comconscflag;
    894 		} else {
    895 			t.c_ospeed = TTYDEF_SPEED;
    896 			t.c_cflag = TTYDEF_CFLAG;
    897 		}
    898 		if (ISSET(sc->sc_swflags, TIOCFLAG_CLOCAL))
    899 			SET(t.c_cflag, CLOCAL);
    900 		if (ISSET(sc->sc_swflags, TIOCFLAG_CRTSCTS))
    901 			SET(t.c_cflag, CRTSCTS);
    902 		if (ISSET(sc->sc_swflags, TIOCFLAG_MDMBUF))
    903 			SET(t.c_cflag, MDMBUF);
    904 		/* Make sure comparam() will do something. */
    905 		tp->t_ospeed = 0;
    906 		(void) comparam(tp, &t);
    907 		tp->t_iflag = TTYDEF_IFLAG;
    908 		tp->t_oflag = TTYDEF_OFLAG;
    909 		tp->t_lflag = TTYDEF_LFLAG;
    910 		ttychars(tp);
    911 		ttsetwater(tp);
    912 
    913 		s2 = splserial();
    914 		COM_LOCK(sc);
    915 
    916 		/*
    917 		 * Turn on DTR.  We must always do this, even if carrier is not
    918 		 * present, because otherwise we'd have to use TIOCSDTR
    919 		 * immediately after setting CLOCAL, which applications do not
    920 		 * expect.  We always assert DTR while the device is open
    921 		 * unless explicitly requested to deassert it.
    922 		 */
    923 		com_modem(sc, 1);
    924 
    925 		/* Clear the input ring, and unblock. */
    926 		sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
    927 		sc->sc_rbavail = com_rbuf_size;
    928 		com_iflush(sc);
    929 		CLR(sc->sc_rx_flags, RX_ANY_BLOCK);
    930 		com_hwiflow(sc);
    931 
    932 #ifdef COM_DEBUG
    933 		if (com_debug)
    934 			comstatus(sc, "comopen  ");
    935 #endif
    936 
    937 		COM_UNLOCK(sc);
    938 		splx(s2);
    939 	}
    940 
    941 	splx(s);
    942 
    943 	error = ttyopen(tp, COMDIALOUT(dev), ISSET(flag, O_NONBLOCK));
    944 	if (error)
    945 		goto bad;
    946 
    947 	error = (*tp->t_linesw->l_open)(dev, tp);
    948 	if (error)
    949 		goto bad;
    950 
    951 	return (0);
    952 
    953 bad:
    954 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
    955 		/*
    956 		 * We failed to open the device, and nobody else had it opened.
    957 		 * Clean up the state as appropriate.
    958 		 */
    959 		com_shutdown(sc);
    960 	}
    961 
    962 	return (error);
    963 }
    964 
    965 int
    966 comclose(dev_t dev, int flag, int mode, struct proc *p)
    967 {
    968 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(dev));
    969 	struct tty *tp = sc->sc_tty;
    970 
    971 	/* XXX This is for cons.c. */
    972 	if (!ISSET(tp->t_state, TS_ISOPEN))
    973 		return (0);
    974 
    975 	(*tp->t_linesw->l_close)(tp, flag);
    976 	ttyclose(tp);
    977 
    978 	if (COM_ISALIVE(sc) == 0)
    979 		return (0);
    980 
    981 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
    982 		/*
    983 		 * Although we got a last close, the device may still be in
    984 		 * use; e.g. if this was the dialout node, and there are still
    985 		 * processes waiting for carrier on the non-dialout node.
    986 		 */
    987 		com_shutdown(sc);
    988 	}
    989 
    990 	return (0);
    991 }
    992 
    993 int
    994 comread(dev_t dev, struct uio *uio, int flag)
    995 {
    996 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(dev));
    997 	struct tty *tp = sc->sc_tty;
    998 
    999 	if (COM_ISALIVE(sc) == 0)
   1000 		return (EIO);
   1001 
   1002 	return ((*tp->t_linesw->l_read)(tp, uio, flag));
   1003 }
   1004 
   1005 int
   1006 comwrite(dev_t dev, struct uio *uio, int flag)
   1007 {
   1008 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(dev));
   1009 	struct tty *tp = sc->sc_tty;
   1010 
   1011 	if (COM_ISALIVE(sc) == 0)
   1012 		return (EIO);
   1013 
   1014 	return ((*tp->t_linesw->l_write)(tp, uio, flag));
   1015 }
   1016 
   1017 int
   1018 compoll(dev_t dev, int events, struct proc *p)
   1019 {
   1020 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(dev));
   1021 	struct tty *tp = sc->sc_tty;
   1022 
   1023 	if (COM_ISALIVE(sc) == 0)
   1024 		return (EIO);
   1025 
   1026 	return ((*tp->t_linesw->l_poll)(tp, events, p));
   1027 }
   1028 
   1029 struct tty *
   1030 comtty(dev_t dev)
   1031 {
   1032 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(dev));
   1033 	struct tty *tp = sc->sc_tty;
   1034 
   1035 	return (tp);
   1036 }
   1037 
   1038 int
   1039 comioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct proc *p)
   1040 {
   1041 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(dev));
   1042 	struct tty *tp = sc->sc_tty;
   1043 	int error;
   1044 	int s;
   1045 
   1046 	if (COM_ISALIVE(sc) == 0)
   1047 		return (EIO);
   1048 
   1049 	error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, p);
   1050 	if (error != EPASSTHROUGH)
   1051 		return (error);
   1052 
   1053 	error = ttioctl(tp, cmd, data, flag, p);
   1054 	if (error != EPASSTHROUGH)
   1055 		return (error);
   1056 
   1057 	error = 0;
   1058 
   1059 	s = splserial();
   1060 	COM_LOCK(sc);
   1061 
   1062 	switch (cmd) {
   1063 	case TIOCSBRK:
   1064 		com_break(sc, 1);
   1065 		break;
   1066 
   1067 	case TIOCCBRK:
   1068 		com_break(sc, 0);
   1069 		break;
   1070 
   1071 	case TIOCSDTR:
   1072 		com_modem(sc, 1);
   1073 		break;
   1074 
   1075 	case TIOCCDTR:
   1076 		com_modem(sc, 0);
   1077 		break;
   1078 
   1079 	case TIOCGFLAGS:
   1080 		*(int *)data = sc->sc_swflags;
   1081 		break;
   1082 
   1083 	case TIOCSFLAGS:
   1084 		error = suser(p->p_ucred, &p->p_acflag);
   1085 		if (error)
   1086 			break;
   1087 		sc->sc_swflags = *(int *)data;
   1088 		break;
   1089 
   1090 	case TIOCMSET:
   1091 	case TIOCMBIS:
   1092 	case TIOCMBIC:
   1093 		tiocm_to_com(sc, cmd, *(int *)data);
   1094 		break;
   1095 
   1096 	case TIOCMGET:
   1097 		*(int *)data = com_to_tiocm(sc);
   1098 		break;
   1099 
   1100 	case PPS_IOC_CREATE:
   1101 		break;
   1102 
   1103 	case PPS_IOC_DESTROY:
   1104 		break;
   1105 
   1106 	case PPS_IOC_GETPARAMS: {
   1107 		pps_params_t *pp;
   1108 		pp = (pps_params_t *)data;
   1109 		*pp = sc->ppsparam;
   1110 		break;
   1111 	}
   1112 
   1113 	case PPS_IOC_SETPARAMS: {
   1114 	  	pps_params_t *pp;
   1115 		int mode;
   1116 		pp = (pps_params_t *)data;
   1117 		if (pp->mode & ~ppscap) {
   1118 			error = EINVAL;
   1119 			break;
   1120 		}
   1121 		sc->ppsparam = *pp;
   1122 	 	/*
   1123 		 * Compute msr masks from user-specified timestamp state.
   1124 		 */
   1125 		mode = sc->ppsparam.mode;
   1126 		switch (mode & PPS_CAPTUREBOTH) {
   1127 		case 0:
   1128 			sc->sc_ppsmask = 0;
   1129 			break;
   1130 
   1131 		case PPS_CAPTUREASSERT:
   1132 			sc->sc_ppsmask = MSR_DCD;
   1133 			sc->sc_ppsassert = MSR_DCD;
   1134 			sc->sc_ppsclear = -1;
   1135 			break;
   1136 
   1137 		case PPS_CAPTURECLEAR:
   1138 			sc->sc_ppsmask = MSR_DCD;
   1139 			sc->sc_ppsassert = -1;
   1140 			sc->sc_ppsclear = 0;
   1141 			break;
   1142 
   1143 		case PPS_CAPTUREBOTH:
   1144 			sc->sc_ppsmask = MSR_DCD;
   1145 			sc->sc_ppsassert = MSR_DCD;
   1146 			sc->sc_ppsclear = 0;
   1147 			break;
   1148 
   1149 		default:
   1150 			error = EINVAL;
   1151 			break;
   1152 		}
   1153 		break;
   1154 	}
   1155 
   1156 	case PPS_IOC_GETCAP:
   1157 		*(int*)data = ppscap;
   1158 		break;
   1159 
   1160 	case PPS_IOC_FETCH: {
   1161 		pps_info_t *pi;
   1162 		pi = (pps_info_t *)data;
   1163 		*pi = sc->ppsinfo;
   1164 		break;
   1165 	}
   1166 
   1167 #ifdef PPS_SYNC
   1168 	case PPS_IOC_KCBIND: {
   1169 		int edge = (*(int *)data) & PPS_CAPTUREBOTH;
   1170 
   1171 		if (edge == 0) {
   1172 			/*
   1173 			 * remove binding for this source; ignore
   1174 			 * the request if this is not the current
   1175 			 * hardpps source
   1176 			 */
   1177 			if (pps_kc_hardpps_source == sc) {
   1178 				pps_kc_hardpps_source = NULL;
   1179 				pps_kc_hardpps_mode = 0;
   1180 			}
   1181 		} else {
   1182 			/*
   1183 			 * bind hardpps to this source, replacing any
   1184 			 * previously specified source or edges
   1185 			 */
   1186 			pps_kc_hardpps_source = sc;
   1187 			pps_kc_hardpps_mode = edge;
   1188 		}
   1189 		break;
   1190 	}
   1191 #endif /* PPS_SYNC */
   1192 
   1193 	case TIOCDCDTIMESTAMP:	/* XXX old, overloaded  API used by xntpd v3 */
   1194 		/*
   1195 		 * Some GPS clocks models use the falling rather than
   1196 		 * rising edge as the on-the-second signal.
   1197 		 * The old API has no way to specify PPS polarity.
   1198 		 */
   1199 		sc->sc_ppsmask = MSR_DCD;
   1200 #ifndef PPS_TRAILING_EDGE
   1201 		sc->sc_ppsassert = MSR_DCD;
   1202 		sc->sc_ppsclear = -1;
   1203 		TIMESPEC_TO_TIMEVAL((struct timeval *)data,
   1204 		    &sc->ppsinfo.assert_timestamp);
   1205 #else
   1206 		sc->sc_ppsassert = -1;
   1207 		sc->sc_ppsclear = 0;
   1208 		TIMESPEC_TO_TIMEVAL((struct timeval *)data,
   1209 		    &sc->ppsinfo.clear_timestamp);
   1210 #endif
   1211 		break;
   1212 
   1213 	default:
   1214 		error = EPASSTHROUGH;
   1215 		break;
   1216 	}
   1217 
   1218 	COM_UNLOCK(sc);
   1219 	splx(s);
   1220 
   1221 #ifdef COM_DEBUG
   1222 	if (com_debug)
   1223 		comstatus(sc, "comioctl ");
   1224 #endif
   1225 
   1226 	return (error);
   1227 }
   1228 
   1229 integrate void
   1230 com_schedrx(struct com_softc *sc)
   1231 {
   1232 
   1233 	sc->sc_rx_ready = 1;
   1234 
   1235 	/* Wake up the poller. */
   1236 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
   1237 	softintr_schedule(sc->sc_si);
   1238 #else
   1239 #ifndef __NO_SOFT_SERIAL_INTERRUPT
   1240 	setsoftserial();
   1241 #else
   1242 	if (!com_softintr_scheduled) {
   1243 		com_softintr_scheduled = 1;
   1244 		callout_reset(&comsoft_callout, 1, comsoft, NULL);
   1245 	}
   1246 #endif
   1247 #endif
   1248 }
   1249 
   1250 void
   1251 com_break(struct com_softc *sc, int onoff)
   1252 {
   1253 
   1254 	if (onoff)
   1255 		SET(sc->sc_lcr, LCR_SBREAK);
   1256 	else
   1257 		CLR(sc->sc_lcr, LCR_SBREAK);
   1258 
   1259 	if (!sc->sc_heldchange) {
   1260 		if (sc->sc_tx_busy) {
   1261 			sc->sc_heldtbc = sc->sc_tbc;
   1262 			sc->sc_tbc = 0;
   1263 			sc->sc_heldchange = 1;
   1264 		} else
   1265 			com_loadchannelregs(sc);
   1266 	}
   1267 }
   1268 
   1269 void
   1270 com_modem(struct com_softc *sc, int onoff)
   1271 {
   1272 
   1273 	if (sc->sc_mcr_dtr == 0)
   1274 		return;
   1275 
   1276 	if (onoff)
   1277 		SET(sc->sc_mcr, sc->sc_mcr_dtr);
   1278 	else
   1279 		CLR(sc->sc_mcr, sc->sc_mcr_dtr);
   1280 
   1281 	if (!sc->sc_heldchange) {
   1282 		if (sc->sc_tx_busy) {
   1283 			sc->sc_heldtbc = sc->sc_tbc;
   1284 			sc->sc_tbc = 0;
   1285 			sc->sc_heldchange = 1;
   1286 		} else
   1287 			com_loadchannelregs(sc);
   1288 	}
   1289 }
   1290 
   1291 void
   1292 tiocm_to_com(struct com_softc *sc, u_long how, int ttybits)
   1293 {
   1294 	u_char combits;
   1295 
   1296 	combits = 0;
   1297 	if (ISSET(ttybits, TIOCM_DTR))
   1298 		SET(combits, MCR_DTR);
   1299 	if (ISSET(ttybits, TIOCM_RTS))
   1300 		SET(combits, MCR_RTS);
   1301 
   1302 	switch (how) {
   1303 	case TIOCMBIC:
   1304 		CLR(sc->sc_mcr, combits);
   1305 		break;
   1306 
   1307 	case TIOCMBIS:
   1308 		SET(sc->sc_mcr, combits);
   1309 		break;
   1310 
   1311 	case TIOCMSET:
   1312 		CLR(sc->sc_mcr, MCR_DTR | MCR_RTS);
   1313 		SET(sc->sc_mcr, combits);
   1314 		break;
   1315 	}
   1316 
   1317 	if (!sc->sc_heldchange) {
   1318 		if (sc->sc_tx_busy) {
   1319 			sc->sc_heldtbc = sc->sc_tbc;
   1320 			sc->sc_tbc = 0;
   1321 			sc->sc_heldchange = 1;
   1322 		} else
   1323 			com_loadchannelregs(sc);
   1324 	}
   1325 }
   1326 
   1327 int
   1328 com_to_tiocm(struct com_softc *sc)
   1329 {
   1330 	u_char combits;
   1331 	int ttybits = 0;
   1332 
   1333 	combits = sc->sc_mcr;
   1334 	if (ISSET(combits, MCR_DTR))
   1335 		SET(ttybits, TIOCM_DTR);
   1336 	if (ISSET(combits, MCR_RTS))
   1337 		SET(ttybits, TIOCM_RTS);
   1338 
   1339 	combits = sc->sc_msr;
   1340 	if (ISSET(combits, MSR_DCD))
   1341 		SET(ttybits, TIOCM_CD);
   1342 	if (ISSET(combits, MSR_CTS))
   1343 		SET(ttybits, TIOCM_CTS);
   1344 	if (ISSET(combits, MSR_DSR))
   1345 		SET(ttybits, TIOCM_DSR);
   1346 	if (ISSET(combits, MSR_RI | MSR_TERI))
   1347 		SET(ttybits, TIOCM_RI);
   1348 
   1349 	if (ISSET(sc->sc_ier, IER_ERXRDY | IER_ETXRDY | IER_ERLS | IER_EMSC))
   1350 		SET(ttybits, TIOCM_LE);
   1351 
   1352 	return (ttybits);
   1353 }
   1354 
   1355 static u_char
   1356 cflag2lcr(tcflag_t cflag)
   1357 {
   1358 	u_char lcr = 0;
   1359 
   1360 	switch (ISSET(cflag, CSIZE)) {
   1361 	case CS5:
   1362 		SET(lcr, LCR_5BITS);
   1363 		break;
   1364 	case CS6:
   1365 		SET(lcr, LCR_6BITS);
   1366 		break;
   1367 	case CS7:
   1368 		SET(lcr, LCR_7BITS);
   1369 		break;
   1370 	case CS8:
   1371 		SET(lcr, LCR_8BITS);
   1372 		break;
   1373 	}
   1374 	if (ISSET(cflag, PARENB)) {
   1375 		SET(lcr, LCR_PENAB);
   1376 		if (!ISSET(cflag, PARODD))
   1377 			SET(lcr, LCR_PEVEN);
   1378 	}
   1379 	if (ISSET(cflag, CSTOPB))
   1380 		SET(lcr, LCR_STOPB);
   1381 
   1382 	return (lcr);
   1383 }
   1384 
   1385 int
   1386 comparam(struct tty *tp, struct termios *t)
   1387 {
   1388 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(tp->t_dev));
   1389 	int ospeed;
   1390 	u_char lcr;
   1391 	int s;
   1392 
   1393 	if (COM_ISALIVE(sc) == 0)
   1394 		return (EIO);
   1395 
   1396 #ifdef COM_HAYESP
   1397 	if (sc->sc_type == COM_TYPE_HAYESP) {
   1398 		int prescaler, speed;
   1399 
   1400 		/*
   1401 		 * Calculate UART clock prescaler.  It should be in
   1402 		 * range of 0 .. 3.
   1403 		 */
   1404 		for (prescaler = 0, speed = t->c_ospeed; prescaler < 4;
   1405 		    prescaler++, speed /= 2)
   1406 			if ((ospeed = comspeed(speed, sc->sc_frequency,
   1407 					       sc->sc_type)) > 0)
   1408 				break;
   1409 
   1410 		if (prescaler == 4)
   1411 			return (EINVAL);
   1412 		sc->sc_prescaler = prescaler;
   1413 	} else
   1414 #endif
   1415 	ospeed = comspeed(t->c_ospeed, sc->sc_frequency, sc->sc_type);
   1416 
   1417 	/* Check requested parameters. */
   1418 	if (ospeed < 0)
   1419 		return (EINVAL);
   1420 	if (t->c_ispeed && t->c_ispeed != t->c_ospeed)
   1421 		return (EINVAL);
   1422 
   1423 	/*
   1424 	 * For the console, always force CLOCAL and !HUPCL, so that the port
   1425 	 * is always active.
   1426 	 */
   1427 	if (ISSET(sc->sc_swflags, TIOCFLAG_SOFTCAR) ||
   1428 	    ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
   1429 		SET(t->c_cflag, CLOCAL);
   1430 		CLR(t->c_cflag, HUPCL);
   1431 	}
   1432 
   1433 	/*
   1434 	 * If there were no changes, don't do anything.  This avoids dropping
   1435 	 * input and improves performance when all we did was frob things like
   1436 	 * VMIN and VTIME.
   1437 	 */
   1438 	if (tp->t_ospeed == t->c_ospeed &&
   1439 	    tp->t_cflag == t->c_cflag)
   1440 		return (0);
   1441 
   1442 	lcr = ISSET(sc->sc_lcr, LCR_SBREAK) | cflag2lcr(t->c_cflag);
   1443 
   1444 	s = splserial();
   1445 	COM_LOCK(sc);
   1446 
   1447 	sc->sc_lcr = lcr;
   1448 
   1449 	/*
   1450 	 * If we're not in a mode that assumes a connection is present, then
   1451 	 * ignore carrier changes.
   1452 	 */
   1453 	if (ISSET(t->c_cflag, CLOCAL | MDMBUF))
   1454 		sc->sc_msr_dcd = 0;
   1455 	else
   1456 		sc->sc_msr_dcd = MSR_DCD;
   1457 	/*
   1458 	 * Set the flow control pins depending on the current flow control
   1459 	 * mode.
   1460 	 */
   1461 	if (ISSET(t->c_cflag, CRTSCTS)) {
   1462 		sc->sc_mcr_dtr = MCR_DTR;
   1463 		sc->sc_mcr_rts = MCR_RTS;
   1464 		sc->sc_msr_cts = MSR_CTS;
   1465 		sc->sc_efr = EFR_AUTORTS | EFR_AUTOCTS;
   1466 	} else if (ISSET(t->c_cflag, MDMBUF)) {
   1467 		/*
   1468 		 * For DTR/DCD flow control, make sure we don't toggle DTR for
   1469 		 * carrier detection.
   1470 		 */
   1471 		sc->sc_mcr_dtr = 0;
   1472 		sc->sc_mcr_rts = MCR_DTR;
   1473 		sc->sc_msr_cts = MSR_DCD;
   1474 		sc->sc_efr = 0;
   1475 	} else {
   1476 		/*
   1477 		 * If no flow control, then always set RTS.  This will make
   1478 		 * the other side happy if it mistakenly thinks we're doing
   1479 		 * RTS/CTS flow control.
   1480 		 */
   1481 		sc->sc_mcr_dtr = MCR_DTR | MCR_RTS;
   1482 		sc->sc_mcr_rts = 0;
   1483 		sc->sc_msr_cts = 0;
   1484 		sc->sc_efr = 0;
   1485 		if (ISSET(sc->sc_mcr, MCR_DTR))
   1486 			SET(sc->sc_mcr, MCR_RTS);
   1487 		else
   1488 			CLR(sc->sc_mcr, MCR_RTS);
   1489 	}
   1490 	sc->sc_msr_mask = sc->sc_msr_cts | sc->sc_msr_dcd;
   1491 
   1492 #if 0
   1493 	if (ospeed == 0)
   1494 		CLR(sc->sc_mcr, sc->sc_mcr_dtr);
   1495 	else
   1496 		SET(sc->sc_mcr, sc->sc_mcr_dtr);
   1497 #endif
   1498 
   1499 	sc->sc_dlbl = ospeed;
   1500 	sc->sc_dlbh = ospeed >> 8;
   1501 
   1502 	/*
   1503 	 * Set the FIFO threshold based on the receive speed.
   1504 	 *
   1505 	 *  * If it's a low speed, it's probably a mouse or some other
   1506 	 *    interactive device, so set the threshold low.
   1507 	 *  * If it's a high speed, trim the trigger level down to prevent
   1508 	 *    overflows.
   1509 	 *  * Otherwise set it a bit higher.
   1510 	 */
   1511 	if (sc->sc_type == COM_TYPE_HAYESP)
   1512 		sc->sc_fifo = FIFO_DMA_MODE | FIFO_ENABLE | FIFO_TRIGGER_8;
   1513 	else if (ISSET(sc->sc_hwflags, COM_HW_FIFO))
   1514 		sc->sc_fifo = FIFO_ENABLE |
   1515 		    (t->c_ospeed <= 1200 ? FIFO_TRIGGER_1 : FIFO_TRIGGER_8);
   1516 	else
   1517 		sc->sc_fifo = 0;
   1518 
   1519 	/* And copy to tty. */
   1520 	tp->t_ispeed = 0;
   1521 	tp->t_ospeed = t->c_ospeed;
   1522 	tp->t_cflag = t->c_cflag;
   1523 
   1524 	if (!sc->sc_heldchange) {
   1525 		if (sc->sc_tx_busy) {
   1526 			sc->sc_heldtbc = sc->sc_tbc;
   1527 			sc->sc_tbc = 0;
   1528 			sc->sc_heldchange = 1;
   1529 		} else
   1530 			com_loadchannelregs(sc);
   1531 	}
   1532 
   1533 	if (!ISSET(t->c_cflag, CHWFLOW)) {
   1534 		/* Disable the high water mark. */
   1535 		sc->sc_r_hiwat = 0;
   1536 		sc->sc_r_lowat = 0;
   1537 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
   1538 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
   1539 			com_schedrx(sc);
   1540 		}
   1541 		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED)) {
   1542 			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED);
   1543 			com_hwiflow(sc);
   1544 		}
   1545 	} else {
   1546 		sc->sc_r_hiwat = com_rbuf_hiwat;
   1547 		sc->sc_r_lowat = com_rbuf_lowat;
   1548 	}
   1549 
   1550 	COM_UNLOCK(sc);
   1551 	splx(s);
   1552 
   1553 	/*
   1554 	 * Update the tty layer's idea of the carrier bit, in case we changed
   1555 	 * CLOCAL or MDMBUF.  We don't hang up here; we only do that by
   1556 	 * explicit request.
   1557 	 */
   1558 	(void) (*tp->t_linesw->l_modem)(tp, ISSET(sc->sc_msr, MSR_DCD));
   1559 
   1560 #ifdef COM_DEBUG
   1561 	if (com_debug)
   1562 		comstatus(sc, "comparam ");
   1563 #endif
   1564 
   1565 	if (!ISSET(t->c_cflag, CHWFLOW)) {
   1566 		if (sc->sc_tx_stopped) {
   1567 			sc->sc_tx_stopped = 0;
   1568 			comstart(tp);
   1569 		}
   1570 	}
   1571 
   1572 	return (0);
   1573 }
   1574 
   1575 void
   1576 com_iflush(struct com_softc *sc)
   1577 {
   1578 	bus_space_tag_t iot = sc->sc_iot;
   1579 	bus_space_handle_t ioh = sc->sc_ioh;
   1580 #ifdef DIAGNOSTIC
   1581 	int reg;
   1582 #endif
   1583 	int timo;
   1584 
   1585 #ifdef DIAGNOSTIC
   1586 	reg = 0xffff;
   1587 #endif
   1588 	timo = 50000;
   1589 	/* flush any pending I/O */
   1590 	while (ISSET(bus_space_read_1(iot, ioh, com_lsr), LSR_RXRDY)
   1591 	    && --timo)
   1592 #ifdef DIAGNOSTIC
   1593 		reg =
   1594 #else
   1595 		    (void)
   1596 #endif
   1597 		    bus_space_read_1(iot, ioh, com_data);
   1598 #ifdef DIAGNOSTIC
   1599 	if (!timo)
   1600 		printf("%s: com_iflush timeout %02x\n", sc->sc_dev.dv_xname,
   1601 		       reg);
   1602 #endif
   1603 }
   1604 
   1605 void
   1606 com_loadchannelregs(struct com_softc *sc)
   1607 {
   1608 	bus_space_tag_t iot = sc->sc_iot;
   1609 	bus_space_handle_t ioh = sc->sc_ioh;
   1610 
   1611 	/* XXXXX necessary? */
   1612 	com_iflush(sc);
   1613 
   1614 #ifdef COM_PXA2X0
   1615 	if (sc->sc_type == COM_TYPE_PXA2x0)
   1616 		bus_space_write_1(iot, ioh, com_ier, IER_EUART);
   1617 	else
   1618 #endif
   1619 		bus_space_write_1(iot, ioh, com_ier, 0);
   1620 
   1621 	if (ISSET(sc->sc_hwflags, COM_HW_FLOW)) {
   1622 		bus_space_write_1(iot, ioh, com_lcr, LCR_EERS);
   1623 		bus_space_write_1(iot, ioh, com_efr, sc->sc_efr);
   1624 	}
   1625 	bus_space_write_1(iot, ioh, com_lcr, sc->sc_lcr | LCR_DLAB);
   1626 	bus_space_write_1(iot, ioh, com_dlbl, sc->sc_dlbl);
   1627 	bus_space_write_1(iot, ioh, com_dlbh, sc->sc_dlbh);
   1628 	bus_space_write_1(iot, ioh, com_lcr, sc->sc_lcr);
   1629 	bus_space_write_1(iot, ioh, com_mcr, sc->sc_mcr_active = sc->sc_mcr);
   1630 	bus_space_write_1(iot, ioh, com_fifo, sc->sc_fifo);
   1631 #ifdef COM_HAYESP
   1632 	if (sc->sc_type == COM_TYPE_HAYESP) {
   1633 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD1,
   1634 		    HAYESP_SETPRESCALER);
   1635 		bus_space_write_1(iot, sc->sc_hayespioh, HAYESP_CMD2,
   1636 		    sc->sc_prescaler);
   1637 	}
   1638 #endif
   1639 
   1640 	bus_space_write_1(iot, ioh, com_ier, sc->sc_ier);
   1641 }
   1642 
   1643 int
   1644 comhwiflow(struct tty *tp, int block)
   1645 {
   1646 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(tp->t_dev));
   1647 	int s;
   1648 
   1649 	if (COM_ISALIVE(sc) == 0)
   1650 		return (0);
   1651 
   1652 	if (sc->sc_mcr_rts == 0)
   1653 		return (0);
   1654 
   1655 	s = splserial();
   1656 	COM_LOCK(sc);
   1657 
   1658 	if (block) {
   1659 		if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
   1660 			SET(sc->sc_rx_flags, RX_TTY_BLOCKED);
   1661 			com_hwiflow(sc);
   1662 		}
   1663 	} else {
   1664 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
   1665 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
   1666 			com_schedrx(sc);
   1667 		}
   1668 		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
   1669 			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED);
   1670 			com_hwiflow(sc);
   1671 		}
   1672 	}
   1673 
   1674 	COM_UNLOCK(sc);
   1675 	splx(s);
   1676 	return (1);
   1677 }
   1678 
   1679 /*
   1680  * (un)block input via hw flowcontrol
   1681  */
   1682 void
   1683 com_hwiflow(struct com_softc *sc)
   1684 {
   1685 	bus_space_tag_t iot = sc->sc_iot;
   1686 	bus_space_handle_t ioh = sc->sc_ioh;
   1687 
   1688 	if (sc->sc_mcr_rts == 0)
   1689 		return;
   1690 
   1691 	if (ISSET(sc->sc_rx_flags, RX_ANY_BLOCK)) {
   1692 		CLR(sc->sc_mcr, sc->sc_mcr_rts);
   1693 		CLR(sc->sc_mcr_active, sc->sc_mcr_rts);
   1694 	} else {
   1695 		SET(sc->sc_mcr, sc->sc_mcr_rts);
   1696 		SET(sc->sc_mcr_active, sc->sc_mcr_rts);
   1697 	}
   1698 	bus_space_write_1(iot, ioh, com_mcr, sc->sc_mcr_active);
   1699 }
   1700 
   1701 
   1702 void
   1703 comstart(struct tty *tp)
   1704 {
   1705 	struct com_softc *sc = device_lookup(&com_cd, COMUNIT(tp->t_dev));
   1706 	bus_space_tag_t iot = sc->sc_iot;
   1707 	bus_space_handle_t ioh = sc->sc_ioh;
   1708 	int s;
   1709 
   1710 	if (COM_ISALIVE(sc) == 0)
   1711 		return;
   1712 
   1713 	s = spltty();
   1714 	if (ISSET(tp->t_state, TS_BUSY | TS_TIMEOUT | TS_TTSTOP))
   1715 		goto out;
   1716 	if (sc->sc_tx_stopped)
   1717 		goto out;
   1718 
   1719 	if (tp->t_outq.c_cc <= tp->t_lowat) {
   1720 		if (ISSET(tp->t_state, TS_ASLEEP)) {
   1721 			CLR(tp->t_state, TS_ASLEEP);
   1722 			wakeup(&tp->t_outq);
   1723 		}
   1724 		selwakeup(&tp->t_wsel);
   1725 		if (tp->t_outq.c_cc == 0)
   1726 			goto out;
   1727 	}
   1728 
   1729 	/* Grab the first contiguous region of buffer space. */
   1730 	{
   1731 		u_char *tba;
   1732 		int tbc;
   1733 
   1734 		tba = tp->t_outq.c_cf;
   1735 		tbc = ndqb(&tp->t_outq, 0);
   1736 
   1737 		(void)splserial();
   1738 		COM_LOCK(sc);
   1739 
   1740 		sc->sc_tba = tba;
   1741 		sc->sc_tbc = tbc;
   1742 	}
   1743 
   1744 	SET(tp->t_state, TS_BUSY);
   1745 	sc->sc_tx_busy = 1;
   1746 
   1747 	/* Enable transmit completion interrupts if necessary. */
   1748 	if (!ISSET(sc->sc_ier, IER_ETXRDY)) {
   1749 		SET(sc->sc_ier, IER_ETXRDY);
   1750 		bus_space_write_1(iot, ioh, com_ier, sc->sc_ier);
   1751 	}
   1752 
   1753 #if 0
   1754 	/* Output the first chunk of the contiguous buffer. */
   1755 	if (!ISSET(sc->sc_hwflags, COM_HW_NO_TXPRELOAD)) {
   1756 		u_int n;
   1757 
   1758 		n = sc->sc_tbc;
   1759 		if (n > sc->sc_fifolen)
   1760 			n = sc->sc_fifolen;
   1761 		bus_space_write_multi_1(iot, ioh, com_data, sc->sc_tba, n);
   1762 		sc->sc_tbc -= n;
   1763 		sc->sc_tba += n;
   1764 	}
   1765 #endif
   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 					goto next;
   2097 				put += 2;
   2098 				if (put >= end)
   2099 					put = sc->sc_rbuf;
   2100 				cc--;
   2101 			next:
   2102 				lsr = bus_space_read_1(iot, ioh, com_lsr);
   2103 				if (!ISSET(lsr, LSR_RCV_MASK))
   2104 					break;
   2105 			}
   2106 
   2107 			/*
   2108 			 * Current string of incoming characters ended because
   2109 			 * no more data was available or we ran out of space.
   2110 			 * Schedule a receive event if any data was received.
   2111 			 * If we're out of space, turn off receive interrupts.
   2112 			 */
   2113 			sc->sc_rbput = put;
   2114 			sc->sc_rbavail = cc;
   2115 			if (!ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED))
   2116 				sc->sc_rx_ready = 1;
   2117 
   2118 			/*
   2119 			 * See if we are in danger of overflowing a buffer. If
   2120 			 * so, use hardware flow control to ease the pressure.
   2121 			 */
   2122 			if (!ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED) &&
   2123 			    cc < sc->sc_r_hiwat) {
   2124 				SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
   2125 				com_hwiflow(sc);
   2126 			}
   2127 
   2128 			/*
   2129 			 * If we're out of space, disable receive interrupts
   2130 			 * until the queue has drained a bit.
   2131 			 */
   2132 			if (!cc) {
   2133 				SET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
   2134 #ifdef COM_PXA2X0
   2135 				if (sc->sc_type == COM_TYPE_PXA2x0)
   2136 					CLR(sc->sc_ier, IER_ERXRDY|IER_ERXTOUT);
   2137 				else
   2138 #endif
   2139 					CLR(sc->sc_ier, IER_ERXRDY);
   2140 				bus_space_write_1(iot, ioh, com_ier,
   2141 				    sc->sc_ier);
   2142 			}
   2143 		} else {
   2144 			if ((iir & (IIR_RXRDY|IIR_TXRDY)) == IIR_RXRDY) {
   2145 				(void) bus_space_read_1(iot, ioh, com_data);
   2146 				continue;
   2147 			}
   2148 		}
   2149 
   2150 		msr = bus_space_read_1(iot, ioh, com_msr);
   2151 		delta = msr ^ sc->sc_msr;
   2152 		sc->sc_msr = msr;
   2153 		/*
   2154 		 * Pulse-per-second (PSS) signals on edge of DCD?
   2155 		 * Process these even if line discipline is ignoring DCD.
   2156 		 */
   2157 		if (delta & sc->sc_ppsmask) {
   2158 			struct timeval tv;
   2159 		    	if ((msr & sc->sc_ppsmask) == sc->sc_ppsassert) {
   2160 				/* XXX nanotime() */
   2161 				microtime(&tv);
   2162 				TIMEVAL_TO_TIMESPEC(&tv,
   2163 				    &sc->ppsinfo.assert_timestamp);
   2164 				if (sc->ppsparam.mode & PPS_OFFSETASSERT) {
   2165 					timespecadd(&sc->ppsinfo.assert_timestamp,
   2166 					    &sc->ppsparam.assert_offset,
   2167 						    &sc->ppsinfo.assert_timestamp);
   2168 				}
   2169 
   2170 #ifdef PPS_SYNC
   2171 				if (pps_kc_hardpps_source == sc &&
   2172 				    pps_kc_hardpps_mode & PPS_CAPTUREASSERT) {
   2173 					hardpps(&tv, tv.tv_usec);
   2174 				}
   2175 #endif
   2176 				sc->ppsinfo.assert_sequence++;
   2177 				sc->ppsinfo.current_mode = sc->ppsparam.mode;
   2178 
   2179 			} else if ((msr & sc->sc_ppsmask) == sc->sc_ppsclear) {
   2180 				/* XXX nanotime() */
   2181 				microtime(&tv);
   2182 				TIMEVAL_TO_TIMESPEC(&tv,
   2183 				    &sc->ppsinfo.clear_timestamp);
   2184 				if (sc->ppsparam.mode & PPS_OFFSETCLEAR) {
   2185 					timespecadd(&sc->ppsinfo.clear_timestamp,
   2186 					    &sc->ppsparam.clear_offset,
   2187 					    &sc->ppsinfo.clear_timestamp);
   2188 				}
   2189 
   2190 #ifdef PPS_SYNC
   2191 				if (pps_kc_hardpps_source == sc &&
   2192 				    pps_kc_hardpps_mode & PPS_CAPTURECLEAR) {
   2193 					hardpps(&tv, tv.tv_usec);
   2194 				}
   2195 #endif
   2196 				sc->ppsinfo.clear_sequence++;
   2197 				sc->ppsinfo.current_mode = sc->ppsparam.mode;
   2198 			}
   2199 		}
   2200 
   2201 		/*
   2202 		 * Process normal status changes
   2203 		 */
   2204 		if (ISSET(delta, sc->sc_msr_mask)) {
   2205 			SET(sc->sc_msr_delta, delta);
   2206 
   2207 			/*
   2208 			 * Stop output immediately if we lose the output
   2209 			 * flow control signal or carrier detect.
   2210 			 */
   2211 			if (ISSET(~msr, sc->sc_msr_mask)) {
   2212 				sc->sc_tbc = 0;
   2213 				sc->sc_heldtbc = 0;
   2214 #ifdef COM_DEBUG
   2215 				if (com_debug)
   2216 					comstatus(sc, "comintr  ");
   2217 #endif
   2218 			}
   2219 
   2220 			sc->sc_st_check = 1;
   2221 		}
   2222 	} while (!ISSET((iir =
   2223 	    bus_space_read_1(iot, ioh, com_iir)), IIR_NOPEND) &&
   2224 	    /*
   2225 	     * Since some device (e.g., ST16C1550) doesn't clear IIR_TXRDY
   2226 	     * by IIR read, so we can't do this way: `process all interrupts,
   2227 	     * then do TX if possble'.
   2228 	     */
   2229 	    (iir & IIR_IMASK) != IIR_TXRDY);
   2230 
   2231 	/*
   2232 	 * Read LSR again, since there may be an interrupt between
   2233 	 * the last LSR read and IIR read above.
   2234 	 */
   2235 	lsr = bus_space_read_1(iot, ioh, com_lsr);
   2236 
   2237 	/*
   2238 	 * See if data can be transmitted as well.
   2239 	 * Schedule tx done event if no data left
   2240 	 * and tty was marked busy.
   2241 	 */
   2242 	if (ISSET(lsr, LSR_TXRDY)) {
   2243 		/*
   2244 		 * If we've delayed a parameter change, do it now, and restart
   2245 		 * output.
   2246 		 */
   2247 		if (sc->sc_heldchange) {
   2248 			com_loadchannelregs(sc);
   2249 			sc->sc_heldchange = 0;
   2250 			sc->sc_tbc = sc->sc_heldtbc;
   2251 			sc->sc_heldtbc = 0;
   2252 		}
   2253 
   2254 		/* Output the next chunk of the contiguous buffer, if any. */
   2255 		if (sc->sc_tbc > 0) {
   2256 			u_int n;
   2257 
   2258 			n = sc->sc_tbc;
   2259 			if (n > sc->sc_fifolen)
   2260 				n = sc->sc_fifolen;
   2261 			bus_space_write_multi_1(iot, ioh, com_data, sc->sc_tba, n);
   2262 			sc->sc_tbc -= n;
   2263 			sc->sc_tba += n;
   2264 		} else {
   2265 			/* Disable transmit completion interrupts if necessary. */
   2266 			if (ISSET(sc->sc_ier, IER_ETXRDY)) {
   2267 				CLR(sc->sc_ier, IER_ETXRDY);
   2268 				bus_space_write_1(iot, ioh, com_ier, sc->sc_ier);
   2269 			}
   2270 			if (sc->sc_tx_busy) {
   2271 				sc->sc_tx_busy = 0;
   2272 				sc->sc_tx_done = 1;
   2273 			}
   2274 		}
   2275 	}
   2276 
   2277 	if (!ISSET((iir = bus_space_read_1(iot, ioh, com_iir)), IIR_NOPEND))
   2278 		goto again;
   2279 
   2280 	COM_UNLOCK(sc);
   2281 
   2282 	/* Wake up the poller. */
   2283 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
   2284 	softintr_schedule(sc->sc_si);
   2285 #else
   2286 #ifndef __NO_SOFT_SERIAL_INTERRUPT
   2287 	setsoftserial();
   2288 #else
   2289 	if (!com_softintr_scheduled) {
   2290 		com_softintr_scheduled = 1;
   2291 		callout_reset(&comsoft_callout, 1, comsoft, NULL);
   2292 	}
   2293 #endif
   2294 #endif
   2295 
   2296 #if NRND > 0 && defined(RND_COM)
   2297 	rnd_add_uint32(&sc->rnd_source, iir | lsr);
   2298 #endif
   2299 
   2300 	return (1);
   2301 }
   2302 
   2303 /*
   2304  * The following functions are polled getc and putc routines, shared
   2305  * by the console and kgdb glue.
   2306  *
   2307  * The read-ahead code is so that you can detect pending in-band
   2308  * cn_magic in polled mode while doing output rather than having to
   2309  * wait until the kernel decides it needs input.
   2310  */
   2311 
   2312 #define MAX_READAHEAD	20
   2313 static int com_readahead[MAX_READAHEAD];
   2314 static int com_readaheadcount = 0;
   2315 
   2316 int
   2317 com_common_getc(dev_t dev, bus_space_tag_t iot, bus_space_handle_t ioh)
   2318 {
   2319 	int s = splserial();
   2320 	u_char stat, c;
   2321 
   2322 	/* got a character from reading things earlier */
   2323 	if (com_readaheadcount > 0) {
   2324 		int i;
   2325 
   2326 		c = com_readahead[0];
   2327 		for (i = 1; i < com_readaheadcount; i++) {
   2328 			com_readahead[i-1] = com_readahead[i];
   2329 		}
   2330 		com_readaheadcount--;
   2331 		splx(s);
   2332 		return (c);
   2333 	}
   2334 
   2335 	/* block until a character becomes available */
   2336 	while (!ISSET(stat = bus_space_read_1(iot, ioh, com_lsr), LSR_RXRDY))
   2337 		;
   2338 
   2339 	c = bus_space_read_1(iot, ioh, com_data);
   2340 	stat = bus_space_read_1(iot, ioh, com_iir);
   2341 	{
   2342 		int cn_trapped = 0; /* unused */
   2343 #ifdef DDB
   2344 		extern int db_active;
   2345 		if (!db_active)
   2346 #endif
   2347 			cn_check_magic(dev, c, com_cnm_state);
   2348 	}
   2349 	splx(s);
   2350 	return (c);
   2351 }
   2352 
   2353 void
   2354 com_common_putc(dev_t dev, bus_space_tag_t iot, bus_space_handle_t ioh, int c)
   2355 {
   2356 	int s = splserial();
   2357 	int cin, stat, timo;
   2358 
   2359 	if (com_readaheadcount < MAX_READAHEAD
   2360 	     && ISSET(stat = bus_space_read_1(iot, ioh, com_lsr), LSR_RXRDY)) {
   2361 		int cn_trapped = 0;
   2362 		cin = bus_space_read_1(iot, ioh, com_data);
   2363 		stat = bus_space_read_1(iot, ioh, com_iir);
   2364 		cn_check_magic(dev, cin, com_cnm_state);
   2365 		com_readahead[com_readaheadcount++] = cin;
   2366 	}
   2367 
   2368 	/* wait for any pending transmission to finish */
   2369 	timo = 150000;
   2370 	while (!ISSET(bus_space_read_1(iot, ioh, com_lsr), LSR_TXRDY) && --timo)
   2371 		continue;
   2372 
   2373 	bus_space_write_1(iot, ioh, com_data, c);
   2374 	COM_BARRIER(iot, ioh, BR | BW);
   2375 
   2376 	splx(s);
   2377 }
   2378 
   2379 /*
   2380  * Initialize UART for use as console or KGDB line.
   2381  */
   2382 int
   2383 cominit(bus_space_tag_t iot, bus_addr_t iobase, int rate, int frequency,
   2384     int type, tcflag_t cflag, bus_space_handle_t *iohp)
   2385 {
   2386 	bus_space_handle_t ioh;
   2387 
   2388 	if (bus_space_map(iot, iobase, COM_NPORTS, 0, &ioh))
   2389 		return (ENOMEM); /* ??? */
   2390 
   2391 	bus_space_write_1(iot, ioh, com_lcr, LCR_EERS);
   2392 	bus_space_write_1(iot, ioh, com_efr, 0);
   2393 	bus_space_write_1(iot, ioh, com_lcr, LCR_DLAB);
   2394 	rate = comspeed(rate, frequency, type);
   2395 	bus_space_write_1(iot, ioh, com_dlbl, rate);
   2396 	bus_space_write_1(iot, ioh, com_dlbh, rate >> 8);
   2397 	bus_space_write_1(iot, ioh, com_lcr, cflag2lcr(cflag));
   2398 	bus_space_write_1(iot, ioh, com_mcr, MCR_DTR | MCR_RTS);
   2399 	bus_space_write_1(iot, ioh, com_fifo,
   2400 	    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_1);
   2401 #ifdef COM_PXA2X0
   2402 	if (type == COM_TYPE_PXA2x0)
   2403 		bus_space_write_1(iot, ioh, com_ier, IER_EUART);
   2404 	else
   2405 #endif
   2406 		bus_space_write_1(iot, ioh, com_ier, 0);
   2407 
   2408 	*iohp = ioh;
   2409 	return (0);
   2410 }
   2411 
   2412 /*
   2413  * Following are all routines needed for COM to act as console
   2414  */
   2415 struct consdev comcons = {
   2416 	NULL, NULL, comcngetc, comcnputc, comcnpollc, NULL, NULL, NULL,
   2417 	NODEV, CN_NORMAL
   2418 };
   2419 
   2420 
   2421 int
   2422 comcnattach(bus_space_tag_t iot, bus_addr_t iobase, int rate, int frequency,
   2423     int type, tcflag_t cflag)
   2424 {
   2425 	int res;
   2426 
   2427 	res = cominit(iot, iobase, rate, frequency, type, cflag, &comconsioh);
   2428 	if (res)
   2429 		return (res);
   2430 
   2431 	cn_tab = &comcons;
   2432 	cn_init_magic(&com_cnm_state);
   2433 	cn_set_magic("\047\001"); /* default magic is BREAK */
   2434 
   2435 	comconstag = iot;
   2436 	comconsaddr = iobase;
   2437 	comconsrate = rate;
   2438 	comconscflag = cflag;
   2439 
   2440 	return (0);
   2441 }
   2442 
   2443 int
   2444 comcngetc(dev_t dev)
   2445 {
   2446 
   2447 	return (com_common_getc(dev, comconstag, comconsioh));
   2448 }
   2449 
   2450 /*
   2451  * Console kernel output character routine.
   2452  */
   2453 void
   2454 comcnputc(dev_t dev, int c)
   2455 {
   2456 
   2457 	com_common_putc(dev, comconstag, comconsioh, c);
   2458 }
   2459 
   2460 void
   2461 comcnpollc(dev_t dev, int on)
   2462 {
   2463 
   2464 }
   2465 
   2466 #ifdef KGDB
   2467 int
   2468 com_kgdb_attach(bus_space_tag_t iot, bus_addr_t iobase, int rate,
   2469     int frequency, int type, tcflag_t cflag)
   2470 {
   2471 	int res;
   2472 
   2473 	if (iot == comconstag && iobase == comconsaddr) {
   2474 #if !defined(DDB)
   2475 		return (EBUSY); /* cannot share with console */
   2476 #else
   2477 		com_kgdb_ioh = comconsioh;
   2478 #endif
   2479 	} else {
   2480 		res = cominit(iot, iobase, rate, frequency, type, cflag,
   2481 			      &com_kgdb_ioh);
   2482 		if (res)
   2483 			return (res);
   2484 
   2485 		/*
   2486 		 * XXXfvdl this shouldn't be needed, but the cn_magic goo
   2487 		 * expects this to be initialized
   2488 		 */
   2489 		cn_init_magic(&com_cnm_state);
   2490 		cn_set_magic("\047\001");
   2491 	}
   2492 
   2493 	kgdb_attach(com_kgdb_getc, com_kgdb_putc, NULL);
   2494 	kgdb_dev = 123; /* unneeded, only to satisfy some tests */
   2495 
   2496 	com_kgdb_iot = iot;
   2497 	com_kgdb_addr = iobase;
   2498 
   2499 	return (0);
   2500 }
   2501 
   2502 /* ARGSUSED */
   2503 int
   2504 com_kgdb_getc(void *arg)
   2505 {
   2506 
   2507 	return (com_common_getc(NODEV, com_kgdb_iot, com_kgdb_ioh));
   2508 }
   2509 
   2510 /* ARGSUSED */
   2511 void
   2512 com_kgdb_putc(void *arg, int c)
   2513 {
   2514 
   2515 	com_common_putc(NODEV, com_kgdb_iot, com_kgdb_ioh, c);
   2516 }
   2517 #endif /* KGDB */
   2518 
   2519 /* helper function to identify the com ports used by
   2520  console or KGDB (and not yet autoconf attached) */
   2521 int
   2522 com_is_console(bus_space_tag_t iot, bus_addr_t iobase, bus_space_handle_t *ioh)
   2523 {
   2524 	bus_space_handle_t help;
   2525 
   2526 	if (!comconsattached &&
   2527 	    iot == comconstag && iobase == comconsaddr)
   2528 		help = comconsioh;
   2529 #ifdef KGDB
   2530 	else if (!com_kgdb_attached &&
   2531 	    iot == com_kgdb_iot && iobase == com_kgdb_addr)
   2532 		help = com_kgdb_ioh;
   2533 #endif
   2534 	else
   2535 		return (0);
   2536 
   2537 	if (ioh)
   2538 		*ioh = help;
   2539 	return (1);
   2540 }
   2541