path: root/drivers.c

/* $Id$ */
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <stdio.h>
#include <math.h>
#include <stdarg.h>

#include "gpsd_config.h"
#include "gpsd.h"
#include "bits.h"	/* for getbeuw(), to extract big-endiamn words */

extern const struct gps_type_t zodiac_binary;
extern const struct gps_type_t ubx_binary;

ssize_t generic_get(struct gps_device_t *session)
{
    return packet_get(session->gpsdata.gps_fd, &session->packet);
}

#if defined(NMEA_ENABLE) || defined(SIRF_ENABLE) || defined(EVERMORE_ENABLE)  || defined(ITRAX_ENABLE)  || defined(NAVCOM_ENABLE)
ssize_t pass_rtcm(struct gps_device_t *session, char *buf, size_t rtcmbytes)
/* most GPSes take their RTCM corrections straight up */
{
    return gpsd_write(session, buf, rtcmbytes);
}
#endif

#ifdef NMEA_ENABLE
/**************************************************************************
 *
 * Generic driver -- straight NMEA 0183
 *
 **************************************************************************/

gps_mask_t nmea_parse_input(struct gps_device_t *session)
{
    if (session->packet.type == COMMENT_PACKET) {
	return 0;
    } else if (session->packet.type != NMEA_PACKET) {
	const struct gps_type_t **dp;

	for (dp = gpsd_drivers; *dp; dp++) {
	    if (session->packet.type == (*dp)->packet_type) {
		gpsd_report(LOG_WARN, "%s packet seen when NMEA expected.\n",
			    (*dp)->type_name);
		gpsd_switch_driver(session, (*dp)->type_name);
		return (*dp)->parse_packet(session);
	    }
	}
	return 0;
    } else /* session->packet.type == NMEA_PACKET) */ {
	gps_mask_t st = 0;
#ifdef GARMINTXT_ENABLE
	if (session->packet.outbuflen >= 56) {
	    if ((char) *session->packet.outbuffer == '@') {
		/* Garmin Simple Text packet received; it starts with '@' is terminated with \r\n and has length 57 bytes */
		(void)gpsd_switch_driver(session, "Garmin Simple Text");
		return garmintxt_parse(session);
	    }
	}
#endif /* GARMINTXT_ENABLE */

#ifdef OCEANSERVER_ENABLE
	if (strncmp((char *)session->packet.outbuffer, "$C", 2)==0 || strncmp((char *)session->packet.outbuffer, "$OHPR", 5)==0) {
	    (void)gpsd_switch_driver(session, "OceanServer Digital Compas OS5000");
	    return  1;
	}
#endif /* OCEANSERVER_ENABLE */

	gpsd_report(LOG_IO, "<= GPS: %s", session->packet.outbuffer);

	if ((st=nmea_parse((char *)session->packet.outbuffer, session))==0) {
#ifdef NON_NMEA_ENABLE
	    const struct gps_type_t **dp;

	    /* maybe this is a trigger string for a driver we know about? */
#ifdef UBX_ENABLE
	    if(strncmp((char *)session->packet.outbuffer, "$GPTXT,01,01,02,MOD", 19)==0) {
		ubx_catch_model(session, session->packet.outbuffer, session->packet.outbuflen);
		(void)gpsd_switch_driver(session, "uBlox UBX binary");
		return 0;
	    }
#endif /* UBX_ENABLE */
	    for (dp = gpsd_drivers; *dp; dp++) {
		char	*trigger = (*dp)->trigger;

		if (trigger!=NULL && strncmp((char *)session->packet.outbuffer, trigger, strlen(trigger))==0 && isatty(session->gpsdata.gps_fd)!=0) {
		    gpsd_report(LOG_PROG, "found %s.\n", trigger);
		    (void)gpsd_switch_driver(session, (*dp)->type_name);
		    return DEVICEID_SET;
		}
	    }
#endif /* NON_NMEA_ENABLE */
	    gpsd_report(LOG_WARN, "unknown sentence: \"%s\"\n", session->packet.outbuffer);
	}
#ifdef NTPSHM_ENABLE
	/* this magic number is derived from observation */
	if (session->context->enable_ntpshm &&
	    (st & TIME_SET) != 0 &&
	    (session->gpsdata.fix.time!=session->last_fixtime)) {
	    (void)ntpshm_put(session, session->gpsdata.fix.time);
	    session->last_fixtime = session->gpsdata.fix.time;
	}
#endif /* NTPSHM_ENABLE */
	return st;
    }
}

static void nmea_probe_subtype(struct gps_device_t *session, unsigned int seq)
{
    /* change this guard if the probe count goes up */ 
    if (seq <= 8)
	gpsd_report(LOG_WARN, "=> Probing device subtype %d\n", seq);
    /*
     * The reason for splitting these probes up by packet sequence
     * number, interleaving them with the first few packet receives,
     * is because many generic-NMEA devices get confused if you send
     * too much at them in one go.
     *
     * A fast response to an early probe will change drivers so the
     * later ones won't be sent at all.  Thus, for best overall
     * performance, order these to probe for the most popular types
     * soonest.
     *
     * Note: don't make the trigger strings identical to the probe,
     * because some NMEA devices (notably SiRFs) will just echo
     * unknown strings right back at you. A useful dodge is to append
     * a comma to the trigger, because that won't be in the response
     * unless there is actual following data.
     */
    switch (seq) {
#ifdef SIRF_ENABLE
    case 0:
	/* probe for Garmin serial GPS -- expect $PGRMC followed by data*/
	(void)nmea_send(session, "$PGRMCE");
	break;
#endif /* SIRF_ENABLE */
#ifdef NMEA_ENABLE
    case 1:
	/*
	 * We used to try to probe for SiRF by issuing "$PSRF105,1"
	 * and expecting "$Ack Input105.".  But it turns out this
	 * only works for SiRF-IIs; SiRF-I and SiRF-III don't respond.
	 * Thus the only reliable probe is to try to flip the SiRF into
	 * binary mode, cluing in the library to revert it on close.
	 *
	 * SiRFs dominate the GPS-mouse market, so we used to put this test 
	 * first. Unfortunately this causes problems for gpsctl, as it cannot
	 * select the NMEA driver without switchining the device back to
	 * binary mode!  Fix this if we ever find a nondisruptive probe string.
	 */
	(void)nmea_send(session,
			"$PSRF100,0,%d,%d,%d,0",
			session->gpsdata.baudrate,
			9-session->gpsdata.stopbits,
			session->gpsdata.stopbits);
	session->back_to_nmea = true;
	break;
    case 2:
	/* probe for the FV-18 -- expect $PFEC,GPint followed by data */
	(void)nmea_send(session, "$PFEC,GPint");
	break;
#endif /* NMEA_ENABLE */
#ifdef EVERMORE_ENABLE
    case 3:
	/* Enable checksum and GGA(1s), GLL(0s), GSA(1s), GSV(1s), RMC(1s), VTG(0s), PEMT101(1s) */
	/* EverMore will reply with: \x10\x02\x04\x38\x8E\xC6\x10\x03 */
	(void)gpsd_write(session,
	    "\x10\x02\x12\x8E\x7F\x01\x01\x00\x01\x01\x01\x00\x01\x00\x00\x00\x00\x00\x00\x13\x10\x03", 22);
	break;
#endif /* EVERMORE_ENABLE */
#ifdef ITRAX_ENABLE
    case 4:
	/* probe for iTrax, looking for "$PFST,OK" */
	(void)nmea_send(session, "$PFST");
	break;
#endif /* ITRAX_ENABLE */
#ifdef GPSCLOCK_ENABLE
    case 5:
	/* probe for Furuno Electric GH-79L4-N (GPSClock); expect $PFEC,GPssd */
	(void)nmea_send(session, "$PFEC,GPsrq");
	break;
#endif /* GPSCLOCK_ENABLE */
#ifdef ASHTECH_ENABLE
    case 6:
	/* probe for Ashtech -- expect $PASHR,RID */
	(void)nmea_send(session, "$PASHQ,RID");
	break;
#endif /* ASHTECH_ENABLE */
#ifdef UBX_ENABLE
    case 7:
	/* probe for UBX -- query software version */
	(void)ubx_write(session, 0x0au, 0x04, NULL, 0);
	break;
#endif /* UBX_ENABLE */
#ifdef MKT3301_ENABLE
    case 8:
	/* probe for MKT-3301 -- expect $PMTK705 */
	(void)nmea_send(session, "$PMTK605");
	break;
#endif /* MKT3301_ENABLE */
    default:
	break;
    }
}

const struct gps_type_t nmea = {
    .type_name      = "Generic NMEA",	/* full name of type */
    .packet_type    = NMEA_PACKET,	/* associated lexer packet type */
    .trigger	    = NULL,		/* it's the default */
    .channels       = 12,		/* consumer-grade GPS */
    .probe_wakeup   = NULL,		/* no wakeup to be done before hunt */
    .probe_detect   = NULL,		/* no probe */
    .probe_subtype  = nmea_probe_subtype, /* probe for special types */
    .get_packet     = generic_get,	/* use generic packet getter */
    .parse_packet   = nmea_parse_input,	/* how to interpret a packet */
    .rtcm_writer    = pass_rtcm,	/* write RTCM data straight */
#ifdef ALLOW_CONTROLSEND
    .control_send   = nmea_write,	/* how to send control strings */
#endif /* ALLOW_CONTROLSEND */
#ifdef ALLOW_RECONFIGURE
    .configurator   = NULL,		/* enable what we need */
    .speed_switcher = NULL,		/* no speed switcher */
    .mode_switcher  = NULL,		/* no mode switcher */
    .rate_switcher  = NULL,		/* no sample-rate switcher */
    .min_cycle      = 1,		/* not relevant, no rate switch */
    .revert	    = NULL,		/* no setting-reversion method */
#endif /* ALLOW_RECONFIGURE */
    .wrapup	    = NULL,		/* no wrapup */
};

#if defined(GARMIN_ENABLE) && defined(NMEA_ENABLE)
/**************************************************************************
 *
 * Garmin NMEA
 *
 **************************************************************************/

#ifdef ALLOW_RECONFIGURE
static void garmin_mode_switch(struct gps_device_t *session, int mode)
/* only does anything in one direction, going to Garmin binary driver */
{
    if (mode == MODE_BINARY) {
	(void)nmea_send(session, "$PGRMC1,1,2,1,,,,2,W,N");
	(void)nmea_send(session, "$PGRMI,,,,,,,R");
	(void)usleep(333);	/* standard Garmin settling time */
	session->gpsdata.driver_mode = MODE_BINARY;
    }
}

static void garmin_nmea_configurator(struct gps_device_t *session, unsigned int seq)
{
    /*
     * Receivers like the Garmin GPS-10 don't handle having having a lot of
     * probes shoved at them very well.
     */
    switch (seq) {
    case 0:
	/* reset some config, AutoFix, WGS84, PPS 
	 * Set the PPS pulse length to 40ms which leaves the Garmin 18-5hz 
         * with a 160ms low state.
         * NOTE: new PPS only takes effect after next power cycle
         */
	(void)nmea_send(session, "$PGRMC,A,,100,,,,,,A,,1,2,1,30");
	break;
    case 1:
	/* once a sec, no averaging, NMEA 2.3, WAAS */
	(void)nmea_send(session, "$PGRMC1,1,1,1,,,,2,W,N");
	break;
    case 2:
	/* get some more config info */
	(void)nmea_send(session, "$PGRMC1E");
	break;
    case 3:
	/* turn off all output except GGA */
	(void)nmea_send(session, "$PGRMO,,2");
	(void)nmea_send(session, "$PGRMO,GPGGA,1");
	break;
    case 4:
	/* enable GPGGA, GPGSA, GPGSV, GPRMC on Garmin serial GPS */
	(void)nmea_send(session, "$PGRMO,GPGSA,1");
	break;
    case 5:
	(void)nmea_send(session, "$PGRMO,GPGSV,1");
	break;
    case 6:
	(void)nmea_send(session, "$PGRMO,GPRMC,1");
	break;
    case 7:
	(void)nmea_send(session, "$PGRMO,PGRME,1");
	break;
    }
}
#endif /* ALLOW_RECONFIGURE */

const struct gps_type_t garmin = {
    .type_name      = "Garmin Serial",	/* full name of type */
    .packet_type    = GARMIN_PACKET,	/* associated lexer packet type */
    .trigger	    = "$PGRMC,",	/* Garmin private */
    .channels       = 12,		/* not used by this driver */
    .probe_wakeup   = NULL,		/* no wakeup to be done before hunt */
    .probe_detect   = NULL,		/* no probe */
    .probe_subtype  = NULL,		/* no further querying */
    .get_packet     = generic_get,	/* use generic packet getter */
    .parse_packet   = nmea_parse_input,	/* how to interpret a packet */
    .rtcm_writer    = NULL,		/* some do, some don't, skip for now */
#ifdef ALLOW_CONTROLSEND
    .control_send   = nmea_write,	/* how to send control strings */
#endif /* ALLOW_CONTROLSEND */
#ifdef ALLOW_RECONFIGURE
    .configurator   = garmin_nmea_configurator,/* enable what we need */
    .speed_switcher = NULL,		/* no speed switcher */
    .mode_switcher  = garmin_mode_switch,	/* mode switcher */
    .rate_switcher  = NULL,		/* no sample-rate switcher */
    .min_cycle      = 1,		/* not relevant, no rate switch */
    .revert	    = NULL,		/* no setting-reversion method */
#endif /*ALLOW_RECONFIGURE */
    .wrapup	    = NULL,		/* no wrapup */
};
#endif /* GARMIN_ENABLE && NMEA_ENABLE */

#ifdef ASHTECH_ENABLE
/**************************************************************************
 *
 * Ashtech (then Thales, now Magellan Professional) Receivers
 *
 **************************************************************************/

#ifdef ALLOW_RECONFIGURE
static void ashtech_configure(struct gps_device_t *session, unsigned int seq)
{
    if (seq == 0){
	/* turn WAAS on. can't hurt... */
	(void)nmea_send(session, "$PASHS,WAS,ON");
	/* reset to known output state */
	(void)nmea_send(session, "$PASHS,NME,ALL,A,OFF");
	/* then turn on some useful sentences */
#ifdef ASHTECH_NOTYET
	/* we could parse these, but they're oversize so they get dropped */
	(void)nmea_send(session, "$PASHS,NME,POS,A,ON");
	(void)nmea_send(session, "$PASHS,NME,SAT,A,ON");
#else
	(void)nmea_send(session, "$PASHS,NME,GGA,A,ON");
	(void)nmea_send(session, "$PASHS,NME,GSA,A,ON");
	(void)nmea_send(session, "$PASHS,NME,GSV,A,ON");
	(void)nmea_send(session, "$PASHS,NME,RMC,A,ON");
#endif
	(void)nmea_send(session, "$PASHS,NME,ZDA,A,ON");
    }
}
#endif /* ALLOW_RECONFIGURE */

static void ashtech_ping(struct gps_device_t *session)
{
	(void)nmea_send(session, "$PASHQ,RID");
}

const struct gps_type_t ashtech = {
    .type_name      = "Ashtech",	/* full name of type */
    .packet_type    = NMEA_PACKET,	/* associated lexer packet type */
    .trigger	    = "$PASHR,RID,",	/* Ashtech receivers respond thus */
    .channels       = 24,		/* not used, GG24 has 24 channels */
    .probe_wakeup   = ashtech_ping,	/* wakeup to be done before hunt */
    .probe_detect   = NULL,		/* no probe */
    .probe_subtype  = NULL,		/* to be sent unconditionally */
    .get_packet     = generic_get,	/* how to get a packet */
    .parse_packet   = nmea_parse_input,	/* how to interpret a packet */
    .rtcm_writer    = pass_rtcm,	/* write RTCM data straight */
#ifdef ALLOW_CONTROLSEND
    .control_send   = nmea_write,	/* how to send control strings */
#endif /* ALLOW_CONTROLSEND */
#ifdef ALLOW_RECONFIGURE
    .configurator   = ashtech_configure, /* change its sentence set */
    .speed_switcher = NULL,		/* no speed switcher */
    .mode_switcher  = NULL,		/* no mode switcher */
    .rate_switcher  = NULL,		/* no sample-rate switcher */
    .min_cycle      = 1,		/* not relevant, no rate switch */
    .revert	    = NULL,		/* no setting-reversion method */
#endif /* ALLOW_RECONFIGURE */
    .wrapup	    = NULL,		/* no wrapup */
};
#endif /* ASHTECH_ENABLE */

#ifdef FV18_ENABLE
/**************************************************************************
 *
 * FV18 -- uses 2 stop bits, needs to be told to send GSAs
 *
 **************************************************************************/

#ifdef ALLOW_RECONFIGURE
static void fv18_configure(struct gps_device_t *session, unsigned int seq)
{
    /*
     * Tell an FV18 to send GSAs so we'll know if 3D is accurate.
     * Suppress GLL and VTG.  Enable ZDA so dates will be accurate for replay.
     */
    if (seq == 0)
	(void)nmea_send(session,
		    "$PFEC,GPint,GSA01,DTM00,ZDA01,RMC01,GLL00,VTG00,GSV05");
}
#endif /* ALLOW_RECONFIGURE */

const struct gps_type_t fv18 = {
    .type_name      = "San Jose Navigation FV18",	/* full name of type */
    .packet_type    = NMEA_PACKET,	/* associated lexer packet type */
    .trigger	    = "$PFEC,GPint,",	/* FV18s should echo the probe */
    .channels       = 12,		/* not used by this driver */
    .probe_wakeup   = NULL,		/* no wakeup to be done before hunt */
    .probe_detect   = NULL,		/* no probe */
    .probe_subtype  = NULL,		/* to be sent unconditionally */
    .get_packet     = generic_get,	/* how to get a packet */
    .parse_packet   = nmea_parse_input,	/* how to interpret a packet */
    .rtcm_writer    = pass_rtcm,	/* write RTCM data straight */
#ifdef ALLOW_CONTROLSEND
    .control_send   = nmea_write,	/* how to send control strings */
#endif /* ALLOW_CONTROLSEND */
#ifdef ALLOW_RECONFIGURE
    .configurator   = fv18_configure,	/* change its sentence set */
    .speed_switcher = NULL,		/* no speed switcher */
    .mode_switcher  = NULL,		/* no mode switcher */
    .rate_switcher  = NULL,		/* no sample-rate switcher */
    .min_cycle      = 1,		/* not relevant, no rate switch */
    .revert	    = NULL,		/* no setting-reversion method */
#endif /* ALLOW_RECONFIGURE */
    .wrapup	    = NULL,		/* no wrapup */
};
#endif /* FV18_ENABLE */

#ifdef GPSCLOCK_ENABLE
/**************************************************************************
 *
 * Furuno Electric GPSClock (GH-79L4)
 *
 **************************************************************************/

/*
 * Based on http://www.tecsys.de/fileadmin/user_upload/pdf/gh79_1an_intant.pdf
 */

static void gpsclock_probe_subtype(struct gps_device_t *session, unsigned int seq)
{
    /*
     * Michael St. Laurent <mikes@hartwellcorp.com> reports that you have to
     * ignore the trailing PPS edge when extracting time from this chip.
     */
    if (seq == 0) {
	gpsd_report(LOG_INF, "PPS trailing edge will be ignored");
	session->driver.nmea.ignore_trailing_edge = true;
    }
}

const struct gps_type_t gpsclock = {
    .type_name      = "Furuno Electric GH-79L4",	/* full name of type */
    .packet_type    = NMEA_PACKET,	/* associated lexer packet type */
    .trigger	    = "$PFEC,GPssd",	/* GPSclock should return this */
    .channels       = 12,		/* not used by this driver */
    .probe_wakeup   = NULL,		/* no wakeup to be done before hunt */
    .probe_detect   = NULL,		/* no probe */
    .probe_subtype  = gpsclock_probe_subtype, /* to be sent unconditionally */
    .get_packet     = generic_get,	/* how to get a packet */
    .parse_packet   = nmea_parse_input,	/* how to interpret a packet */
    .rtcm_writer    = pass_rtcm,	/* write RTCM data straight */
#ifdef ALLOW_CONTROLSEND
    .control_send   = nmea_write,	/* how to send control strings */
#endif /* ALLOW_CONTROLSEND */
#ifdef ALLOW_RECONFIGURE
    .configurator   = NULL,		/* change its sentence set */
    .speed_switcher = NULL,		/* no speed switcher */
    .mode_switcher  = NULL,		/* no mode switcher */
    .rate_switcher  = NULL,		/* sample rate is fixed */
    .min_cycle      = 1,		/* sample rate is fixed */
    .revert	    = NULL,		/* no setting-reversion method */
#endif /* ALLOW_RECONFIGURE */
    .wrapup	    = NULL,		/* no wrapup */
};
#endif /* GPSCLOCK_ENABLE */

#ifdef TRIPMATE_ENABLE
/**************************************************************************
 *
 * TripMate -- extended NMEA, gets faster fix when primed with lat/long/time
 *
 **************************************************************************/

/*
 * Some technical FAQs on the TripMate:
 * http://vancouver-webpages.com/pub/peter/tripmate.faq
 * http://www.asahi-net.or.jp/~KN6Y-GTU/tripmate/trmfaqe.html
 * The TripMate was discontinued sometime before November 1998
 * and was replaced by the Zodiac EarthMate.
 */

static void tripmate_probe_subtype(struct gps_device_t *session, unsigned int seq)
{
    /* TripMate requires this response to the ASTRAL it sends at boot time */
    if (seq == 0)
	(void)nmea_send(session, "$IIGPQ,ASTRAL");
}

#ifdef ALLOW_RECONFIGURE
static void tripmate_configurator(struct gps_device_t *session, unsigned int seq)
{
    /* stop it sending PRWIZCH */
    if (seq == 0)
	(void)nmea_send(session, "$PRWIILOG,ZCH,V,,");
}
#endif /* ALLOW_RECONFIGURE */

static const struct gps_type_t tripmate = {
    .type_name     = "Delorme TripMate",	/* full name of type */
    .packet_type   = NMEA_PACKET,		/* lexer packet type */
    .trigger       ="ASTRAL",			/* tells us to switch */
    .channels      = 12,			/* consumer-grade GPS */
    .probe_wakeup  = NULL,			/* no wakeup before hunt */
    .probe_detect  = NULL,			/* no probe */
    .probe_subtype = tripmate_probe_subtype,	/* send unconditionally */
    .get_packet    = generic_get,		/* how to get a packet */
    .parse_packet  = nmea_parse_input,		/* how to interpret a packet */
    .rtcm_writer   = pass_rtcm,			/* send RTCM data straight */
#ifdef ALLOW_CONTROLSEND
    .control_send   = nmea_write,	/* how to send control strings */
#endif /* ALLOW_CONTROLSEND */
#ifdef ALLOW_RECONFIGURE
    .configurator  = tripmate_configurator,	/* send unconditionally */
    .speed_switcher= NULL,			/* no speed switcher */
    .mode_switcher = NULL,			/* no mode switcher */
    .rate_switcher = NULL,			/* no sample-rate switcher */
    .min_cycle     = 1,				/* no rate switch */
    .revert	   = NULL,			/* no reversion method */
#endif /* ALLOW_RECONFIGURE */
    .wrapup	   = NULL,			/* no wrapup */
};
#endif /* TRIPMATE_ENABLE */

#ifdef EARTHMATE_ENABLE
/**************************************************************************
 *
 * Zodiac EarthMate textual mode
 *
 * Note: This is the pre-2003 version using Zodiac binary protocol.
 * There is a good HOWTO at <http://www.hamhud.net/ka9mva/earthmate.htm>.
 * It has been replaced with a design that uses a SiRF chipset.
 *
 **************************************************************************/

static void earthmate_probe_subtype(struct gps_device_t *session, unsigned int seq)
{
    if (seq == 0) {
	(void)gpsd_write(session, "EARTHA\r\n", 8);
	(void)usleep(10000);
	(void)gpsd_switch_driver(session, "Zodiac Binary");
    }
}

/*@ -redef @*/
static const struct gps_type_t earthmate = {
    .type_name     = "Delorme EarthMate (pre-2003, Zodiac chipset)",
    .packet_type    = NMEA_PACKET,	/* associated lexer packet type */
    .trigger       = "EARTHA",			/* Earthmate trigger string */
    .channels      = 12,			/* not used by NMEA parser */
    .probe_wakeup  = NULL,			/* no wakeup to be done before hunt */
    .probe_detect  = NULL,			/* no probe */
    .probe_subtype = earthmate_probe_subtype,	/* switch us to Zodiac mode */
    .get_packet    = generic_get,		/* how to get a packet */
    .parse_packet  = nmea_parse_input,		/* how to interpret a packet */
    .rtcm_writer   = NULL,			/* don't send RTCM data */
#ifdef ALLOW_CONTROLSEND
    .control_send   = nmea_write,	/* how to send control strings */
#endif /* ALLOW_CONTROLSEND */
#ifdef ALLOW_RECONFIGURE
    .configurator  = NULL,			/* no configuration here */
    .speed_switcher= NULL,			/* no speed switcher */
    .mode_switcher = NULL,			/* no mode switcher */
    .rate_switcher = NULL,			/* no sample-rate switcher */
    .min_cycle     = 1,				/* no rate switch */
    .revert	   = NULL,			/* no reversion method */
#endif /* ALLOW_RECONFIGURE */
    .wrapup	   = NULL,			/* no wrapup code */
};
/*@ -redef @*/
#endif /* EARTHMATE_ENABLE */

#endif /* NMEA_ENABLE */

#ifdef TNT_ENABLE
/**************************************************************************
 * True North Technologies - Revolution 2X Digital compass
 *
 * More info: http://www.tntc.com/
 *
 * This is a digital compass which uses magnetometers to measure the
 * strength of the earth's magnetic field. Based on these measurements
 * it provides a compass heading using NMEA formatted output strings.
 * This is useful to supplement the heading provided by another GPS
 * unit. A GPS heading is unreliable at slow speed or no speed.
 *
 **************************************************************************/

enum {
#include "packet_states.h"
};

static void tnt_add_checksum(char *sentence)
{
    unsigned char sum = '\0';
    char c, *p = sentence;

    if (*p == '@') {
	p++;
    } else {
	gpsd_report(LOG_ERROR, "Bad TNT sentence: '%s'\n", sentence);
    }
    while ( ((c = *p) != '*') && (c != '\0')) {
	sum ^= c;
	p++;
    }
    *p++ = '*';
    /*@i@*/snprintf(p, 4, "%02X\r\n", sum);
}

static int tnt_send(int fd, const char *fmt, ... )
{
    int status;
    char buf[BUFSIZ];
    va_list ap;

    va_start(ap, fmt) ;
    (void)vsnprintf(buf, sizeof(buf)-5, fmt, ap);
    va_end(ap);
    strlcat(buf, "*", BUFSIZ);
    tnt_add_checksum(buf);
    status = (int)write(fd, buf, strlen(buf));
    tcdrain(fd);
    if (status == (int)strlen(buf)) {
	gpsd_report(LOG_IO, "=> GPS: %s\n", buf);
	return status;
    } else {
	gpsd_report(LOG_WARN, "=> GPS: %s FAILED\n", buf);
	return -1;
    }
}

#define TNT_SNIFF_RETRIES       100
/*
 * The True North compass won't start talking
 * unless you ask it to. So to identify it we
 * need to query for its ID string.
 */
static int tnt_packet_sniff(struct gps_device_t *session)
{
    unsigned int n, count = 0;

    gpsd_report(LOG_RAW, "tnt_packet_sniff begins\n");
    for (n = 0; n < TNT_SNIFF_RETRIES; n++)
    {
      count = 0;
      (void)tnt_send(session->gpsdata.gps_fd, "@X?");
      if (ioctl(session->gpsdata.gps_fd, FIONREAD, &count) < 0)
	  return BAD_PACKET;
      if (count == 0) {
	  //int delay = 10000000000.0 / session->gpsdata.baudrate;
	  //gpsd_report(LOG_RAW, "usleep(%d)\n", delay);
	  //usleep(delay);
	  gpsd_report(LOG_RAW, "sleep(1)\n");
	  (void)sleep(1);
      } else if (generic_get(session) >= 0) {
	if((session->packet.type == NMEA_PACKET)&&(session->packet.state == NMEA_RECOGNIZED))
	{
	  gpsd_report(LOG_RAW, "tnt_packet_sniff returns %d\n",session->packet.type);
	  return session->packet.type;
	}
      }
    }

    gpsd_report(LOG_RAW, "tnt_packet_sniff found no packet\n");
    return BAD_PACKET;
}

static void tnt_probe_subtype(struct gps_device_t *session, unsigned int seq UNUSED)
{
  // Send codes to start the flow of data
  //tnt_send(session->gpsdata.gps_fd, "@BA?"); // Query current rate
  //tnt_send(session->gpsdata.gps_fd, "@BA=8"); // Start HTM packet at 1Hz
  /*
   * Sending this twice seems to make it more reliable!!
   * I think it gets the input on the unit synced up.
   */
  (void)tnt_send(session->gpsdata.gps_fd, "@BA=15"); // Start HTM packet at 1200 per minute
  (void)tnt_send(session->gpsdata.gps_fd, "@BA=15"); // Start HTM packet at 1200 per minute
}

static bool tnt_probe(struct gps_device_t *session)
{
  unsigned int *ip;
#ifdef FIXED_PORT_SPEED
    /* just the one fixed port speed... */
    static unsigned int rates[] = {FIXED_PORT_SPEED};
#else /* FIXED_PORT_SPEED not defined */
  /* The supported baud rates */
  static unsigned int rates[] = {38400, 19200, 2400, 4800, 9600 };
#endif /* FIXED_PORT_SPEED defined */

  gpsd_report(LOG_PROG, "Probing TrueNorth Compass\n");

  /*
   * Only block until we get at least one character, whatever the
   * third arg of read(2) says.
   */
  /*@ ignore @*/
  memset(session->ttyset.c_cc,0,sizeof(session->ttyset.c_cc));
  session->ttyset.c_cc[VMIN] = 1;
  /*@ end @*/

  session->ttyset.c_cflag &= ~(PARENB | PARODD | CRTSCTS);
  session->ttyset.c_cflag |= CREAD | CLOCAL;
  session->ttyset.c_iflag = session->ttyset.c_oflag = session->ttyset.c_lflag = (tcflag_t) 0;

  session->baudindex = 0;
  for (ip = rates; ip < rates + sizeof(rates)/sizeof(rates[0]); ip++)
      if (ip == rates || *ip != rates[0])
      {
	  gpsd_report(LOG_PROG, "hunting at speed %d\n", *ip);
	  gpsd_set_speed(session, *ip, 'N',1);
	  if (tnt_packet_sniff(session) != BAD_PACKET) {
	      return true;
	  }
      }
  return false;
}

static const struct gps_type_t trueNorth = {
    .type_name      = "True North",	/* full name of type */
    .packet_type    = NMEA_PACKET,	/* associated lexer packet type */
    .trigger	    = " TNT1500",
    .channels       = 0,		/* not an actual GPS at all */
    .probe_wakeup   = NULL,		/* this will become a real method */
    .probe_detect   = tnt_probe,	/* probe by sending ID query */
    .probe_subtype  = tnt_probe_subtype,/* probe for True North Digital Compass */
    .get_packet     = generic_get,	/* how to get a packet */
    .parse_packet   = nmea_parse_input,	/* how to interpret a packet */
    .rtcm_writer    = NULL,		/* Don't send */
#ifdef ALLOW_CONTROLSEND
    .control_send   = nmea_write,	/* how to send control strings */
#endif /* ALLOW_CONTROLSEND */
#ifdef ALLOW_RECONFIGURE
    .configurator   = NULL,		/* no setting changes */
    .speed_switcher = NULL,		/* no speed switcher */
    .mode_switcher  = NULL,		/* no mode switcher */
    .rate_switcher  = NULL,		/* no wrapup */
    .min_cycle      = 0.5,		/* fixed at 20 samples per second */
    .revert	    = NULL,		/* no setting-reversion method */
#endif /* ALLOW_RECONFIGURE */
    .wrapup	    = NULL,		/* no wrapup */
};
#endif

#ifdef OCEANSERVER_ENABLE
/**************************************************************************
 * OceanServer - Digital Compass, OS5000 Series
 *
 * More info: http://www.ocean-server.com/download/OS5000_Compass_Manual.pdf
 *
 * This is a digital compass which uses magnetometers to measure the
 * strength of the earth's magnetic field. Based on these measurements
 * it provides a compass heading using NMEA formatted output strings.
 * This is useful to supplement the heading provided by another GPS
 * unit. A GPS heading is unreliable at slow speed or no speed.
 *
 **************************************************************************/

static int oceanserver_send(int fd, const char *fmt, ... )
{
    int status;
    char buf[BUFSIZ];
    va_list ap;

    va_start(ap, fmt) ;
    (void)vsnprintf(buf, sizeof(buf)-5, fmt, ap);
    va_end(ap);
    strlcat(buf, "", BUFSIZ);
    status = (int)write(fd, buf, strlen(buf));
    tcdrain(fd);
    if (status == (int)strlen(buf)) {
	gpsd_report(LOG_IO, "=> GPS: %s\n", buf);
	return status;
    } else {
	gpsd_report(LOG_WARN, "=> GPS: %s FAILED\n", buf);
	return -1;
    }
}

#ifdef ALLOW_RECONFIGURE
static void oceanserver_configure(struct gps_device_t *session, unsigned int seq)
{
    if (seq == 0){
	/* report in NMEA format */
	(void)oceanserver_send(session->gpsdata.gps_fd, "2\n");
	/* ship all fields */
	(void)oceanserver_send(session->gpsdata.gps_fd, "X2047");
    }
}
#endif /* ALLOW_RECONFIGURE */

static const struct gps_type_t oceanServer = {
    .type_name      = "OceanServer Digital Compass OS5000", /* full name of type */
    .packet_type    = NMEA_PACKET,	/* associated lexer packet type */
    .trigger	    = "$C,",
    .channels       = 0,		/* not an actual GPS at all */
    .probe_wakeup   = NULL,
    .probe_detect   = NULL,
    .probe_subtype  = NULL,
    .get_packet     = generic_get,	/* how to get a packet */
    .parse_packet   = nmea_parse_input,	/* how to interpret a packet */
    .rtcm_writer    = NULL,		/* Don't send */
#ifdef ALLOW_CONTROLSEND
    .control_send   = nmea_write,	/* how to send control strings */
#endif /* ALLOW_CONTROLSEND */
#ifdef ALLOW_RECONFIGURE
    .configurator   = oceanserver_configure,
    .speed_switcher = NULL,		/* no speed switcher */
    .mode_switcher  = NULL,		/* no mode switcher */
    .rate_switcher  = NULL,		/* no wrapup */
    .min_cycle      = 1,		/* not relevant, no rate switch */
    .revert	    = NULL,		/* no setting-reversion method */
#endif /* ALLOW_RECONFIGURE */
    .wrapup	    = NULL,		/* no wrapup */
};
#endif

#ifdef RTCM104V2_ENABLE
/**************************************************************************
 *
 * RTCM-104 (v2), used for broadcasting DGPS corrections and by DGPS radios
 *
 **************************************************************************/

static gps_mask_t rtcm104v2_analyze(struct gps_device_t *session)
{
    rtcm2_unpack(&session->gpsdata.rtcm2, (char *)session->packet.isgps.buf);
    gpsd_report(LOG_RAW, "RTCM 2.x packet type 0x%02x length %d words: %s\n",
	session->gpsdata.rtcm2.type, session->gpsdata.rtcm2.length+2,
	gpsd_hexdump_wrapper(session->packet.isgps.buf,
	    (session->gpsdata.rtcm2.length+2)*sizeof(isgps30bits_t), LOG_RAW));
    return RTCM2_SET;
}

static const struct gps_type_t rtcm104v2 = {
    .type_name     = "RTCM104V2",	/* full name of type */
    .packet_type   = RTCM2_PACKET,	/* associated lexer packet type */
    .trigger       = NULL,		/* no recognition string */
    .channels      = 0,			/* not used */
    .probe_wakeup  = NULL,		/* no wakeup to be done before hunt */
    .probe_detect  = NULL,		/* no probe */
    .probe_subtype = NULL,		/* no subtypes */
    .get_packet    = generic_get,	/* how to get a packet */
    .parse_packet  = rtcm104v2_analyze,	/*  */
    .rtcm_writer   = NULL,		/* don't send RTCM data,  */
#ifdef ALLOW_CONTROLSEND
    .control_send   = nmea_write,	/* how to send control strings */
#endif /* ALLOW_CONTROLSEND */
#ifdef ALLOW_RECONFIGURE
    .configurator  = NULL,		/* no configurator */
    .speed_switcher= NULL,		/* no speed switcher */
    .mode_switcher = NULL,		/* no mode switcher */
    .rate_switcher = NULL,		/* no sample-rate switcher */
    .min_cycle     = 1,			/* not relevant, no rate switch */
    .revert	   = NULL,		/* no setting-reversion method */
#endif /* ALLOW_RECONFIGURE */
    .wrapup	   = NULL,		/* no wrapup code */
};
#endif /* RTCM104V2_ENABLE */
#ifdef RTCM104V3_ENABLE
/**************************************************************************
 *
 * RTCM-104 (v3), used for broadcasting DGPS corrections and by DGPS radios
 *
 **************************************************************************/

static gps_mask_t rtcm104v3_analyze(struct gps_device_t *session)
{
    uint length = getbeuw(session->packet.inbuffer, 1);
    uint type = getbeuw(session->packet.inbuffer, 3) >> 4;

    gpsd_report(LOG_RAW, "RTCM 3.x packet type %d length %d words: %s\n",
	type, length, gpsd_hexdump_wrapper(session->packet.inbuffer,
	    (size_t)(session->gpsdata.rtcm3.length), LOG_RAW));
    return RTCM3_SET;
}

static const struct gps_type_t rtcm104v3 = {
    .type_name     = "RTCM104V3",	/* full name of type */
    .packet_type   = RTCM3_PACKET,	/* associated lexer packet type */
    .trigger       = NULL,		/* no recognition string */
    .channels      = 0,			/* not used */
    .probe_wakeup  = NULL,		/* no wakeup to be done before hunt */
    .probe_detect  = NULL,		/* no probe */
    .probe_subtype = NULL,		/* no subtypes */
    .get_packet    = generic_get,	/* how to get a packet */
    .parse_packet  = rtcm104v3_analyze,	/*  */
    .rtcm_writer   = NULL,		/* don't send RTCM data,  */
#ifdef ALLOW_CONTROLSEND
    .control_send   = nmea_write,	/* how to send control strings */
#endif /* ALLOW_CONTROLSEND */
#ifdef ALLOW_RECONFIGURE
    .configurator  = NULL,		/* no configurator */
    .speed_switcher= NULL,		/* no speed switcher */
    .mode_switcher = NULL,		/* no mode switcher */
    .rate_switcher = NULL,		/* no sample-rate switcher */
    .min_cycle     = 1,			/* not relevant, no rate switch */
    .revert	   = NULL,		/* no setting-reversion method */
#endif /* ALLOW_RECONFIGURE */
    .wrapup	   = NULL,		/* no wrapup code */
};
#endif /* RTCM104V3_ENABLE */

#ifdef GARMINTXT_ENABLE
/**************************************************************************
 *
 * Garmin Simple Text protocol
 *
 **************************************************************************/

static gps_mask_t garmintxt_parse_input(struct gps_device_t *session)
{
    //gpsd_report(LOG_PROG, "Garmin Simple Text packet\n");
    return garmintxt_parse(session);
}


static const struct gps_type_t garmintxt = {
    .type_name     = "Garmin Simple Text",		/* full name of type */
    .packet_type   = RTCM2_PACKET;	/* associated lexer packet type */
    .trigger       = NULL,		/* no recognition string */
    .channels      = 0,			/* not used */
    .probe_wakeup  = NULL,		/* no wakeup to be done before hunt */
    .probe_detect  = NULL,		/* no probe */
    .probe_subtype = NULL,		/* no subtypes */
    .get_packet    = generic_get,	/* how to get a packet */
    .parse_packet  = garmintxt_parse_input,	/*  */
    .rtcm_writer   = NULL,		/* don't send RTCM data,  */
#ifdef ALLOW_CONTROLSEND
    .control_send   = nmea_write,	/* how to send control strings */
#endif /* ALLOW_CONTROLSEND */
#ifdef ALLOW_RECONFIGURE
    .configurator  = NULL,		/* no configurator */
    .speed_switcher= NULL,		/* no speed switcher */
    .mode_switcher = NULL,		/* no mode switcher */
    .rate_switcher = NULL,		/* no sample-rate switcher */
    .min_cycle     = 1,			/* not relevant, no rate switch */
    .revert	   = NULL,		/* no setting-reversion method */
#endif /* ALLOW_RECONFIGURE */
    .wrapup	   = NULL,		/* no wrapup code */
};
#endif /* GARMINTXT_ENABLE */

#ifdef MKT3301_ENABLE
/**************************************************************************
 *
 * MKT-3301
 *
 **************************************************************************/
const char* mkt_reasons[4] = {"Invalid", "Unsupported", "Valid but Failed", "Valid success"};

gps_mask_t processMKT3301(int c UNUSED, char *field[], struct gps_device_t *session)
{
    int msg, reason;
    gps_mask_t mask;
    mask = 1; //ONLINE_SET;

    switch(msg = atoi(&(field[0])[4]))
    {
	case 705: /*  */
	    (void)strlcat(session->subtype,field[1],64);
	    (void)strlcat(session->subtype,"-",64);
	    (void)strlcat(session->subtype,field[2],64);
	    return 0; /* return a unknown sentence, which will cause the driver switch */
	case 001: /* ACK / NACK */
	    reason = atoi(field[2]);
	    if(atoi(field[1]) == -1)
		gpsd_report(LOG_WARN, "MKT NACK: unknown sentence\n");
	    else if(reason < 3)
		gpsd_report(LOG_WARN, "MKT NACK: %s, reason: %s\n", field[1], mkt_reasons[reason]);
	    else
		gpsd_report(LOG_WARN, "MKT ACK: %s\n", field[1]);
	    break;
	default:
	    return 0; /* ignore */
    }
    return mask;
}

#ifdef ALLOW_RECONFIGURE
static void mkt3301_configure(struct gps_device_t *session, unsigned int seq)
{
/*
0  NMEA_SEN_GLL,  GPGLL   interval - Geographic Position - Latitude longitude
1  NMEA_SEN_RMC,  GPRMC   interval - Recommended Minimum Specific GNSS Sentence
2  NMEA_SEN_VTG,  GPVTG   interval - Course Over Ground and Ground Speed
3  NMEA_SEN_GGA,  GPGGA   interval - GPS Fix Data
4  NMEA_SEN_GSA,  GPGSA   interval - GNSS DOPS and Active Satellites
5  NMEA_SEN_GSV,  GPGSV   interval - GNSS Satellites in View
6  NMEA_SEN_GRS,  GPGRS   interval - GNSS Range Residuals
7  NMEA_SEN_GST,  GPGST   interval - GNSS Pseudorange Errors Statistics
13 NMEA_SEN_MALM, PMTKALM interval - GPS almanac information
14 NMEA_SEN_MEPH, PMTKEPH interval - GPS ephmeris information
15 NMEA_SEN_MDGP, PMTKDGP interval - GPS differential correction information
16 NMEA_SEN_MDBG, PMTKDBG interval – MTK debug information
17 NMEA_SEN_ZDA,  GPZDA   interval - Time & Date
18 NMEA_SEN_MCHN, PMTKCHN interval – GPS channel status

"$PMTK314,1,1,1,1,1,5,1,1,0,0,0,0,0,0,0,0,0,1,0"

*/
    if(seq == 0) {
	(void)nmea_send(session,"$PMTK320,0"); /* power save off */
	(void)nmea_send(session,"$PMTK300,1000,0,0,0.0,0.0"); /* Fix interval */
	(void)nmea_send(session,"$PMTK314,0,1,0,1,1,5,1,1,0,0,0,0,0,0,0,0,0,1,0");
	(void)nmea_send(session,"$PMTK301,2"); /* DGPS is WAAS */
	(void)nmea_send(session,"$PMTK313,1"); /* SBAS enable */
    }
}
#endif /* ALLOW_RECONFIGURE */

const struct gps_type_t mkt3301 = {
    .type_name      = "MKT-3301",	/* full name of type */
    .packet_type    = NMEA_PACKET,	/* associated lexer packet type */
    .trigger	    = "$PMTK705,",	/* MKT-3301s send firmware release name and version */
    .channels       = 12,		/* not used by this driver */
    .probe_wakeup   = NULL,		/* no wakeup to be done before hunt */
    .probe_detect   = NULL,		/* no probe */
    .probe_subtype  = NULL,		/* to be sent unconditionally */
    .get_packet     = generic_get,	/* how to get a packet */
    .parse_packet   = nmea_parse_input,	/* how to interpret a packet */
    .rtcm_writer    = pass_rtcm,	/* write RTCM data straight */
#ifdef ALLOW_CONTROLSEND
    .control_send   = nmea_write,	/* how to send control strings */
#endif /* ALLOW_CONTROLSEND */
#ifdef ALLOW_RECONFIGURE
    .configurator   = mkt3301_configure,	/* change its sentence set */
    .speed_switcher = NULL,		/* no speed switcher */
    .mode_switcher  = NULL,		/* no mode switcher */
    .rate_switcher  = NULL,		/* no sample-rate switcher */
    .min_cycle      = 1,		/* not relevant, no rate switch */
    .revert	    = NULL,		/* no setting-reversion method */
#endif /* ALLOW_RECONFIGURE */
    .wrapup	    = NULL,		/* no wrapup */
};
#endif /* MKT3301_ENABLE */

extern const struct gps_type_t aivdm;
extern const struct gps_type_t garmin_usb_binary, garmin_ser_binary;
extern const struct gps_type_t sirf_binary, tsip_binary;
extern const struct gps_type_t evermore_binary, italk_binary;
extern const struct gps_type_t navcom_binary, superstar2_binary;

/*@ -nullassign @*/
/* the point of this rigamarole is to not have to export a table size */
static const struct gps_type_t *gpsd_driver_array[] = {
#ifdef NMEA_ENABLE
    &nmea,
#ifdef ASHTECH_ENABLE
    &ashtech,
#endif /* ASHTECHV18_ENABLE */
#ifdef TRIPMATE_ENABLE
    &tripmate,
#endif /* TRIPMATE_ENABLE */
#ifdef EARTHMATE_ENABLE
    &earthmate,
#endif /* EARTHMATE_ENABLE */
#ifdef GPSCLOCK_ENABLE
    &gpsclock,
#endif /* GPSCLOCK_ENABLE */
#ifdef GARMIN_ENABLE
    &garmin,
#endif /* GARMIN_ENABLE */
#ifdef MKT3301_ENABLE
    &mkt3301,
#endif /*  MKT3301_ENABLE */
#ifdef OCEANSERVER_ENABLE
    &oceanServer,
#endif /* OCEANSERVER_ENABLE */
#ifdef FV18_ENABLE
    &fv18,
#endif /* FV18_ENABLE */
#ifdef TNT_ENABLE
    &trueNorth,
#endif /* TNT_ENABLE */
#ifdef AIVDM_ENABLE
    &aivdm,
#endif /* AIVDM_ENABLE */
#endif /* NMEA_ENABLE */


#ifdef EVERMORE_ENABLE
    &evermore_binary,
#endif /* EVERMORE_ENABLE */
#ifdef GARMIN_ENABLE
    &garmin_usb_binary,
    &garmin_ser_binary,
#endif /* GARMIN_ENABLE */
#ifdef ITRAX_ENABLE
    &italk_binary,
#endif /* ITRAX_ENABLE */
#ifdef NAVCOM_ENABLE
    &navcom_binary,
#endif /* NAVCOM_ENABLE */
#ifdef SIRF_ENABLE
    &sirf_binary,
#endif /* SIRF_ENABLE */
#ifdef SUPERSTAR2_ENABLE
    &superstar2_binary,
#endif /* SIRF_ENABLE */
#ifdef TSIP_ENABLE
    &tsip_binary,
#endif /* TSIP_ENABLE */
#ifdef UBX_ENABLE
    &ubx_binary,
#endif /* UBX_ENABLE */
#ifdef ZODIAC_ENABLE
    &zodiac_binary,
#endif /* ZODIAC_ENABLE */

#ifdef RTCM104V2_ENABLE
    &rtcm104v2,
#endif /* RTCM104V2_ENABLE */
#ifdef RTCM104V3_ENABLE
    &rtcm104v3,
#endif /* RTCM104V3_ENABLE */
#ifdef GARMINTXT_ENABLE
    &garmintxt,
#endif /* GARMINTXT_ENABLE */
    NULL,
};
/*@ +nullassign @*/
const struct gps_type_t **gpsd_drivers = &gpsd_driver_array[0];