italk.c

gpsd, a popular GPS daemon.

    case ITALK_SEARCH_DONE:
    case ITALK_TRACK_DROP:
    case ITALK_TRACK_STATUS:
    case ITALK_HANDOVER_DATA:
    case ITALK_CORE_SYNC:
    case ITALK_WAAS_RAWDATA:
    case ITALK_ASSISTANCE:
    case ITALK_PULL_FIX:
    case ITALK_MEMCTRL:
    case ITALK_STOP_TASK:
	gpsd_report(LOG_IO, "iTalk not processing packet: id 0x%02x length %d\n", type, len);
	break;
    default:
	gpsd_report(LOG_IO, "iTalk unknown packet: id 0x%02x length %d\n", type, len);
    }
    if (mask == ERROR_SET)
	mask = 0;
    else
	(void)snprintf(session->gpsdata.tag, sizeof(session->gpsdata.tag),
	   "ITK-%02x",type);

    return mask | ONLINE_SET;
}
/*@ -charint @*/

static gps_mask_t italk_parse_input(struct gps_device_t *session)
{
    gps_mask_t st;

    if (session->packet.type == ITALK_PACKET){
	st = italk_parse(session, session->packet.outbuffer, session->packet.outbuflen);
	session->gpsdata.driver_mode = 1;	/* binary */
	return st;
#ifdef NMEA_ENABLE
    } else if (session->packet.type == NMEA_PACKET) {
	st = nmea_parse((char *)session->packet.outbuffer, session);
	session->gpsdata.driver_mode = 0;	/* NMEA */
	return st;
#endif /* NMEA_ENABLE */
    } else
	return 0;
}

static bool italk_set_mode(struct gps_device_t *session UNUSED, 
			      speed_t speed UNUSED, bool mode UNUSED)
{
    /*@ +charint @*/
    unsigned char msg[] = {0,};

    /* HACK THE MESSAGE */

    return italk_write(session->gpsdata.gps_fd, msg, sizeof(msg));
    /*@ +charint @*/
}

static bool italk_speed(struct gps_device_t *session, speed_t speed)
{
    return italk_set_mode(session, speed, true);
}

static void italk_mode(struct gps_device_t *session, int mode)
{
    if (mode == 0) {
	(void)gpsd_switch_driver(session, "Generic NMEA");
	(void)italk_set_mode(session, session->gpsdata.baudrate, false);
	session->gpsdata.driver_mode = 0;	/* NMEA */
    } else
	session->gpsdata.driver_mode = 1;	/* binary */
}

#ifdef ALLOW_RECONFIGURE
static void italk_configurator(struct gps_device_t *session, unsigned int seq)
{
    if (seq == 0 && session->packet.type == NMEA_PACKET)
	(void)italk_set_mode(session, session->gpsdata.baudrate, true);
}
#endif /* ALLOW_RECONFIGURE */

#ifdef __not_yet__
static void italk_ping(struct gps_device_t *session)
/* send a "ping". it may help us detect an itrax more quickly */
{
    char *ping = "<?>";
    (void)gpsd_write(session, ping, 3);
}
#endif /* __not_yet__ */

/* this is everything we export */
struct gps_type_t italk_binary =
{
    .type_name      = "iTalk binary",	/* full name of type */
    .trigger        = NULL,		/* recognize the type */
    .channels       = 12,		/* consumer-grade GPS */
    .probe_wakeup   = NULL,		/* no wakeup to be done before hunt */
    .probe_detect   = NULL,        	/* how to detect at startup time */
    .probe_subtype  = NULL,        	/* initialize the device */
#ifdef ALLOW_RECONFIGURE
    .configurator   = italk_configurator,/* configure the device */
#endif /* ALLOW_RECONFIGURE */
    .get_packet     = generic_get,	/* use generic packet grabber */
    .parse_packet   = italk_parse_input,/* parse message packets */
    .rtcm_writer    = pass_rtcm,	/* send RTCM data straight */
    .speed_switcher = italk_speed,	/* we can change baud rates */
    .mode_switcher  = italk_mode,	/* there is a mode switcher */
    .rate_switcher  = NULL,		/* no sample-rate switcher */
    .cycle_chars    = -1,		/* not relevant, no rate switch */
#ifdef ALLOW_RECONFIGURE
    .revert         = NULL,		/* no setting-reversion method */
#endif /* ALLOW_RECONFIGURE */
    .wrapup         = NULL,		/* no close hook */
    .cycle          = 1,		/* updates every second */
};
#endif /* defined(ITRAX_ENABLE) && defined(BINARY_ENABLE) */

#ifdef ANCIENT_ITRAX_ENABLE
/**************************************************************************
 *
 * The NMEA mode of the iTrax chipset, as used in the FastTrax and others.
 *
 * As described by v1.31 of the NMEA Protocol Specification for the
 * iTrax02 Evaluation Kit, 2003-06-12.
 * v1.18 of the  manual, 2002-19-6, describes effectively
 * the same protocol, but without ZDA.
 *
 **************************************************************************/

/*
 * Enable GGA=0x2000, RMC=0x8000, GSA=0x0002, GSV=0x0001, ZDA=0x0004.
 * Disable GLL=0x1000, VTG=0x4000, FOM=0x0020, PPS=0x0010.
 * This is 82+75+67+(3*60)+34 = 438 characters 
 * 
 * 1200   => at most 1 fix per 4 seconds
 * 2400   => at most 1 fix per 2 seconds
 * 4800   => at most 1 fix per 1 seconds
 * 9600   => at most 2 fixes per second
 * 19200  => at most 4 fixes per second
 * 57600  => at most 13 fixes per second
 * 115200 => at most 26 fixes per second
 *
 * We'd use FOM, but they don't specify a confidence interval.
 */
#define ITRAX_MODESTRING	"$PFST,NMEA,A007,%d\r\n"

static int literal_send(int fd, const char *fmt, ... )
/* ship a raw command to the GPS */
{
    int status;
    char buf[BUFSIZ];
    va_list ap;

    va_start(ap, fmt) ;
    (void)vsnprintf(buf, sizeof(buf), fmt, ap);
    va_end(ap);
    status = (int)write(fd, buf, strlen(buf));
    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;
    }
}

static void itrax_probe_subtype(struct gps_device_t *session, unsigned int seq)
/* start it reporting */
{
    if (seq == 0) {
	/* initialize GPS clock with current system time */ 
	struct tm when;
	double integral, fractional;
	time_t intfixtime;
	char buf[31], frac[6];
	fractional = modf(timestamp(), &integral);
	intfixtime = (time_t)integral;
	(void)gmtime_r(&intfixtime, &when);
	/* FIXME: so what if my local clock is wrong? */
	(void)strftime(buf, sizeof(buf), "$PFST,INITAID,%H%M%S.XX,%d%m%y\r\n", &when);
	(void)snprintf(frac, sizeof(frac), "%.2f", fractional);
	buf[21] = frac[2]; buf[22] = frac[3];
	(void)literal_send(session->gpsdata.gps_fd, buf);
	/* maybe this should be considered a reconfiguration? */
	(void)literal_send(session->gpsdata.gps_fd, "$PFST,START\r\n");
    }
}

#ifdef ALLOW_RECONFIGURE
static void itrax_configurator(struct gps_device_t *session, int seq)
/* set synchronous mode */
{
    if (seq == 0) {
	(void)literal_send(session->gpsdata.gps_fd, "$PFST,SYNCMODE,1\r\n");
	(void)literal_send(session->gpsdata.gps_fd, 
		    ITRAX_MODESTRING, session->gpsdata.baudrate);
    }
}
#endif /* ALLOW_RECONFIGURE */

static bool itrax_speed(struct gps_device_t *session, speed_t speed)
/* change the baud rate */
{
#ifdef ALLOW_RECONFIGURE
    return literal_send(session->gpsdata.gps_fd, ITRAX_MODESTRING, speed) >= 0;
#else
    return false;
#endif /* ALLOW_RECONFIGURE */
}

static bool itrax_rate(struct gps_device_t *session, double rate)
/* change the sample rate of the GPS */
{
#ifdef ALLOW_RECONFIGURE
    return literal_send(session->gpsdata.gps_fd, "$PSFT,FIXRATE,%d\r\n", rate) >= 0;
#else
    return false;
#endif /* ALLOW_RECONFIGURE */
}

static void itrax_wrap(struct gps_device_t *session)
/* stop navigation, this cuts the power drain */
{
#ifdef ALLOW_RECONFIGURE
    (void)literal_send(session->gpsdata.gps_fd, "$PFST,SYNCMODE,0\r\n");
#endif /* ALLOW_RECONFIGURE */
    (void)literal_send(session->gpsdata.gps_fd, "$PFST,STOP\r\n");
}

/*@ -redef @*/
static struct gps_type_t itrax = {
    .type_name     = "iTrax",		/* full name of type */
    .trigger       = "$PFST,OK",	/* tells us to switch to Itrax */
    .channels      = 12,		/* consumer-grade GPS */
    .probe_wakeup  = NULL,		/* no wakeup to be done before hunt */
    .probe_detect  = NULL,		/* no probe */
    .probe_subtype = itrax_probe_subtype,	/* initialize */
#ifdef ALLOW_RECONFIGURE
    .configurator  = itrax_configurator,/* set synchronous mode */
#endif /* ALLOW_RECONFIGURE */
    .get_packet    = generic_get,	/* how to get a packet */
    .parse_packet  = nmea_parse_input,	/* how to interpret a packet */
    .rtcm_writer   = NULL,		/* iTrax doesn't support DGPS/WAAS/EGNOS */
    .speed_switcher= itrax_speed,	/* no speed switcher */
    .mode_switcher = NULL,		/* no mode switcher */
    .rate_switcher = itrax_rate,	/* there's a sample-rate switcher */
    .cycle_chars   = 438,		/* not relevant, no rate switch */
#ifdef ALLOW_RECONFIGURE
    .revert         = NULL,		/* no setting-reversion method */
#endif /* ALLOW_RECONFIGURE */
    .wrapup         = itrax_wrap,	/* sleep the receiver */
    .cycle          = 1,		/* updates every second */
};
/*@ -redef @*/
#endif /* ITRAX_ENABLE */