refclock_mx4200.c

网络时间协议NTP 源码 版本v4.2.0b 该源码用于linux平台下

/*
 * This software was developed by the Computer Systems Engineering group
 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66.
 *
 * Copyright (c) 1992 The Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Lawrence Berkeley Laboratory.
 * 4. The name of the University may not be used to endorse or promote
 *    products derived from this software without specific prior
 *    written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * Modified: Marc Brett <[e-mail]>   Sept, 1999.
 *
 * 1. Added support for alternate PPS schemes, with code mostly
 *    copied from the Oncore driver (Thanks, Poul-Henning Kamp).
 *    This code runs on SunOS 4.1.3 with ppsclock-1.6a1 and Solaris 7.
 */


#ifdef HAVE_CONFIG_H
# include <config.h>
#endif

#if defined(REFCLOCK) && defined(CLOCK_MX4200) && defined(HAVE_PPSAPI)

#include "ntpd.h"
#include "ntp_io.h"
#include "ntp_refclock.h"
#include "ntp_unixtime.h"
#include "ntp_stdlib.h"

#include <stdio.h>
#include <ctype.h>

#include "mx4200.h"

#ifdef HAVE_SYS_TERMIOS_H
# include <sys/termios.h>
#endif
#ifdef HAVE_SYS_PPSCLOCK_H
# include <sys/ppsclock.h>
#endif

#include "ntp_sprintf.h"

#ifndef HAVE_STRUCT_PPSCLOCKEV
struct ppsclockev {
# ifdef HAVE_STRUCT_TIMESPEC
	struct timespec tv;
# else
	struct timeval tv;
# endif
	u_int serial;
};
#endif /* ! HAVE_STRUCT_PPSCLOCKEV */

#ifdef HAVE_PPSAPI
# include "ppsapi_timepps.h"
#endif /* HAVE_PPSAPI */

/*
 * This driver supports the Magnavox Model MX 4200 GPS Receiver
 * adapted to precision timing applications.  It requires the
 * ppsclock line discipline or streams module described in the
 * Line Disciplines and Streams Drivers page. It also requires a
 * gadget box and 1-PPS level converter, such as described in the
 * Pulse-per-second (PPS) Signal Interfacing page.
 *
 * It's likely that other compatible Magnavox receivers such as the
 * MX 4200D, MX 9212, MX 9012R, MX 9112 will be supported by this code.
 */

/*
 * Check this every time you edit the code!
 */
#define YEAR_LAST_MODIFIED 2000

/*
 * GPS Definitions
 */
#define	DEVICE		"/dev/gps%d"	/* device name and unit */
#define	SPEED232	B4800		/* baud */

/*
 * Radio interface parameters
 */
#define	PRECISION	(-18)	/* precision assumed (about 4 us) */
#define	REFID	"GPS\0"		/* reference id */
#define	DESCRIPTION	"Magnavox MX4200 GPS Receiver" /* who we are */
#define	DEFFUDGETIME	0	/* default fudge time (ms) */

#define	SLEEPTIME	32	/* seconds to wait for reconfig to complete */

/*
 * Position Averaging.
 */
#define INTERVAL	1	/* Interval between position measurements (s) */
#define AVGING_TIME	24	/* Number of hours to average */
#define NOT_INITIALIZED	-9999.	/* initial pivot longitude */

/*
 * MX4200 unit control structure.
 */
struct mx4200unit {
	u_int  pollcnt;			/* poll message counter */
	u_int  polled;			/* Hand in a time sample? */
	u_int  lastserial;		/* last pps serial number */
	struct ppsclockev ppsev;	/* PPS control structure */
	double avg_lat;			/* average latitude */
	double avg_lon;			/* average longitude */
	double avg_alt;			/* average height */
	double central_meridian;	/* central meridian */
	double N_fixes;			/* Number of position measurements */
	int    last_leap;		/* leap second warning */
	u_int  moving;			/* mobile platform? */
	u_long sloppyclockflag;		/* fudge flags */
	u_int  known;			/* position known yet? */
	u_long clamp_time;		/* when to stop postion averaging */
	u_long log_time;		/* when to print receiver status */
	pps_handle_t	pps_h;
	pps_params_t	pps_p;
	pps_info_t	pps_i;
};

static char pmvxg[] = "PMVXG";

/* XXX should be somewhere else */
#ifdef __GNUC__
#if __GNUC__ < 2  || (__GNUC__ == 2 && __GNUC_MINOR__ < 5)
#ifndef __attribute__
#define __attribute__(args)
#endif /* __attribute__ */
#endif /* __GNUC__ < 2  || (__GNUC__ == 2 && __GNUC_MINOR__ < 5) */
#else
#ifndef __attribute__
#define __attribute__(args)
#endif /* __attribute__ */
#endif /* __GNUC__ */
/* XXX end */

/*
 * Function prototypes
 */
static	int	mx4200_start	P((int, struct peer *));
static	void	mx4200_shutdown	P((int, struct peer *));
static	void	mx4200_receive	P((struct recvbuf *));
static	void	mx4200_poll	P((int, struct peer *));

static	char *	mx4200_parse_t	P((struct peer *));
static	char *	mx4200_parse_p	P((struct peer *));
static	char *	mx4200_parse_s	P((struct peer *));
#ifdef QSORT_USES_VOID_P
int	mx4200_cmpl_fp	P((const void *, const void *));
#else
int	mx4200_cmpl_fp	P((const l_fp *, const l_fp *));
#endif /* not QSORT_USES_VOID_P */
static	int	mx4200_config	P((struct peer *));
static	void	mx4200_ref	P((struct peer *));
static	void	mx4200_send	P((struct peer *, char *, ...))
    __attribute__ ((format (printf, 2, 3)));
static	u_char	mx4200_cksum	P((char *, int));
static	int	mx4200_jday	P((int, int, int));
static	void	mx4200_debug	P((struct peer *, char *, ...))
    __attribute__ ((format (printf, 2, 3)));
static	int	mx4200_pps	P((struct peer *));

/*
 * Transfer vector
 */
struct	refclock refclock_mx4200 = {
	mx4200_start,		/* start up driver */
	mx4200_shutdown,	/* shut down driver */
	mx4200_poll,		/* transmit poll message */
	noentry,		/* not used (old mx4200_control) */
	noentry,		/* initialize driver (not used) */
	noentry,		/* not used (old mx4200_buginfo) */
	NOFLAGS			/* not used */
};



/*
 * mx4200_start - open the devices and initialize data for processing
 */
static int
mx4200_start(
	int unit,
	struct peer *peer
	)
{
	register struct mx4200unit *up;
	struct refclockproc *pp;
	int fd;
	char gpsdev[20];

	/*
	 * Open serial port
	 */
	(void)sprintf(gpsdev, DEVICE, unit);
	if (!(fd = refclock_open(gpsdev, SPEED232, LDISC_PPS))) {
	    return (0);
	}

	/*
	 * Allocate unit structure
	 */
	if (!(up = (struct mx4200unit *) emalloc(sizeof(struct mx4200unit)))) {
		perror("emalloc");
		(void) close(fd);
		return (0);
	}
	memset((char *)up, 0, sizeof(struct mx4200unit));
	pp = peer->procptr;
	pp->io.clock_recv = mx4200_receive;
	pp->io.srcclock = (caddr_t)peer;
	pp->io.datalen = 0;
	pp->io.fd = fd;
	if (!io_addclock(&pp->io)) {
		(void) close(fd);
		free(up);
		return (0);
	}
	pp->unitptr = (caddr_t)up;

	/*
	 * Initialize miscellaneous variables
	 */
	peer->precision = PRECISION;
	pp->clockdesc = DESCRIPTION;
	memcpy((char *)&pp->refid, REFID, 4);

	/* Ensure the receiver is properly configured */
	return mx4200_config(peer);
}


/*
 * mx4200_shutdown - shut down the clock
 */
static void
mx4200_shutdown(
	int unit,
	struct peer *peer
	)
{
	register struct mx4200unit *up;
	struct refclockproc *pp;

	pp = peer->procptr;
	up = (struct mx4200unit *)pp->unitptr;
	io_closeclock(&pp->io);
	free(up);
}


/*
 * mx4200_config - Configure the receiver
 */
static int
mx4200_config(
	struct peer *peer
	)
{
	char tr_mode;
	int add_mode;
	register struct mx4200unit *up;
	struct refclockproc *pp;
	int mode;

	pp = peer->procptr;
	up = (struct mx4200unit *)pp->unitptr;

	/*
	 * Initialize the unit variables
	 *
	 * STRANGE BEHAVIOUR WARNING: The fudge flags are not available
	 * at the time mx4200_start is called.  These are set later,
	 * and so the code must be prepared to handle changing flags.
	 */
	up->sloppyclockflag = pp->sloppyclockflag;
	if (pp->sloppyclockflag & CLK_FLAG2) {
		up->moving   = 1;	/* Receiver on mobile platform */
		msyslog(LOG_DEBUG, "mx4200_config: mobile platform");
	} else {
		up->moving   = 0;	/* Static Installation */
	}
	up->pollcnt     	= 2;
	up->polled      	= 0;
	up->known       	= 0;
	up->avg_lat     	= 0.0;
	up->avg_lon     	= 0.0;
	up->avg_alt     	= 0.0;
	up->central_meridian	= NOT_INITIALIZED;
	up->N_fixes    		= 0.0;
	up->last_leap   	= 0;	/* LEAP_NOWARNING */
	up->clamp_time  	= current_time + (AVGING_TIME * 60 * 60);
	up->log_time    	= current_time + SLEEPTIME;

	if (time_pps_create(pp->io.fd, &up->pps_h) < 0) {
		perror("time_pps_create");
		msyslog(LOG_ERR,
			"mx4200_config: time_pps_create failed: %m");
		return (0);
	}
	if (time_pps_getcap(up->pps_h, &mode) < 0) {
		msyslog(LOG_ERR,
			"mx4200_config: time_pps_getcap failed: %m");
		return (0);
	}

	if (time_pps_getparams(up->pps_h, &up->pps_p) < 0) {
		msyslog(LOG_ERR,
			"mx4200_config: time_pps_getparams failed: %m");
		return (0);
	}

	/* nb. only turn things on, if someone else has turned something
	 *      on before we get here, leave it alone!
	 */

	up->pps_p.mode = PPS_CAPTUREASSERT | PPS_TSFMT_TSPEC;
	up->pps_p.mode &= mode;		/* only set what is legal */

	if (time_pps_setparams(up->pps_h, &up->pps_p) < 0) {
		perror("time_pps_setparams");
		msyslog(LOG_ERR,
			"mx4200_config: time_pps_setparams failed: %m");
		exit(1);
	}

	if (time_pps_kcbind(up->pps_h, PPS_KC_HARDPPS, PPS_CAPTUREASSERT,
			PPS_TSFMT_TSPEC) < 0) {
		perror("time_pps_kcbind");
		msyslog(LOG_ERR,
			"mx4200_config: time_pps_kcbind failed: %m");
		exit(1);
	}


	/*
	 * "007" Control Port Configuration
	 * Zero the output list (do it twice to flush possible junk)
	 */
	mx4200_send(peer, "%s,%03d,,%d,,,,,,", pmvxg,
	    PMVXG_S_PORTCONF,
	    /* control port output block Label */
	    1);		/* clear current output control list (1=yes) */
	/* add/delete sentences from list */
	/* must be null */
	/* sentence output rate (sec) */
	/* precision for position output */
	/* nmea version for cga & gll output */
	/* pass-through control */
	mx4200_send(peer, "%s,%03d,,%d,,,,,,", pmvxg,
	    PMVXG_S_PORTCONF, 1);

	/*
	 * Request software configuration so we can syslog the firmware version
	 */
	mx4200_send(peer, "%s,%03d", "CDGPQ", PMVXG_D_SOFTCONF);

	/*
	 * "001" Initialization/Mode Control, Part A
	 * Where ARE we?
	 */
	mx4200_send(peer, "%s,%03d,,,,,,,,,,", pmvxg,
	    PMVXG_S_INITMODEA);
	/* day of month */
	/* month of year */
	/* year */
	/* gmt */
	/* latitude   DDMM.MMMM */
	/* north/south */
	/* longitude DDDMM.MMMM */
	/* east/west */
	/* height */
	/* Altitude Reference 1=MSL */

	/*
	 * "001" Initialization/Mode Control, Part B
	 * Start off in 2d/3d coast mode, holding altitude to last known
	 * value if only 3 satellites available.
	 */
	mx4200_send(peer, "%s,%03d,%d,,%.1f,%.1f,%d,%d,%d,%c,%d",
	    pmvxg, PMVXG_S_INITMODEB,
	    3,		/* 2d/3d coast */
	    /* reserved */
	    0.1,	/* hor accel fact as per Steve (m/s**2) */
	    0.1,	/* ver accel fact as per Steve (m/s**2) */
	    10,		/* vdop */
	    10,		/* hdop limit as per Steve */
	    5,		/* elevation limit as per Steve (deg) */
	    'U',	/* time output mode (UTC) */
	    0);		/* local time offset from gmt (HHHMM) */

	/*
	 * "023" Time Recovery Configuration
	 * Get UTC time from a stationary receiver.
	 * (Set field 1 'D' == dynamic if we are on a moving platform).
	 * (Set field 1 'S' == static  if we are not moving).
	 * (Set field 1 'K' == known position if we can initialize lat/lon/alt).
	 */

	if (pp->sloppyclockflag & CLK_FLAG2)
		up->moving   = 1;	/* Receiver on mobile platform */
	else
		up->moving   = 0;	/* Static Installation */

	up->pollcnt  = 2;
	if (up->moving) {
		/* dynamic: solve for pos, alt, time, while moving */
		tr_mode = 'D';
	} else {
		/* static: solve for pos, alt, time, while stationary */
		tr_mode = 'S';
	}
	mx4200_send(peer, "%s,%03d,%c,%c,%c,%d,%d,%d,", pmvxg,
	    PMVXG_S_TRECOVCONF,
	    tr_mode,	/* time recovery mode (see above ) */
	    'U',	/* synchronize to UTC */
	    'A',	/* always output a time pulse */
	    500,	/* max time error in ns */
	    0,		/* user bias in ns */
	    1);		/* output "830" sentences to control port */
			/* Multi-satellite mode */

	/*
	 * Output position information (to calculate fixed installation
	 * location) only if we are not moving
	 */
	if (up->moving) {
		add_mode = 2;	/* delete from list */
	} else {
		add_mode = 1;	/* add to list */
	}


	/*
	 * "007" Control Port Configuration
	 * Output "021" position, height, velocity reports
	 */
	mx4200_send(peer, "%s,%03d,%03d,%d,%d,,%d,,,", pmvxg,
	    PMVXG_S_PORTCONF,
	    PMVXG_D_PHV, /* control port output block Label */
	    0,		/* clear current output control list (0=no) */
	    add_mode,	/* add/delete sentences from list (1=add, 2=del) */
	    		/* must be null */
	    INTERVAL);	/* sentence output rate (sec) */
			/* precision for position output */
			/* nmea version for cga & gll output */
			/* pass-through control */

	return (1);
}

/*
 * mx4200_ref - Reconfigure unit as a reference station at a known position.
 */
static void
mx4200_ref(
	struct peer *peer
	)
{
	register struct mx4200unit *up;
	struct refclockproc *pp;
	double minute, lat, lon, alt;
	char lats[16], lons[16];
	char nsc, ewc;

	pp = peer->procptr;
	up = (struct mx4200unit *)pp->unitptr;

	/* Should never happen! */
	if (up->moving) return;

	/*
	 * Set up to output status information in the near future
	 */
	up->log_time    = current_time + SLEEPTIME;

	/*
	 * "007" Control Port Configuration
	 * Stop outputting "021" position, height, velocity reports
	 */
	mx4200_send(peer, "%s,%03d,%03d,%d,%d,,,,,", pmvxg,
	    PMVXG_S_PORTCONF,
	    PMVXG_D_PHV, /* control port output block Label */
	    0,		/* clear current output control list (0=no) */
	    2);		/* add/delete sentences from list (2=delete) */
			/* must be null */
	    		/* sentence output rate (sec) */
			/* precision for position output */
			/* nmea version for cga & gll output */
			/* pass-through control */

	/*
	 * "001" Initialization/Mode Control, Part B
	 * Put receiver in fully-constrained 2d nav mode
	 */
	mx4200_send(peer, "%s,%03d,%d,,%.1f,%.1f,%d,%d,%d,%c,%d",
	    pmvxg, PMVXG_S_INITMODEB,
	    2,		/* 2d nav */
	    /* reserved */
	    0.1,	/* hor accel fact as per Steve (m/s**2) */
	    0.1,	/* ver accel fact as per Steve (m/s**2) */
	    10,		/* vdop */
	    10,		/* hdop limit as per Steve */
	    5,		/* elevation limit as per Steve (deg) */
	    'U',	/* time output mode (UTC) */
	    0);		/* local time offset from gmt (HHHMM) */

	/*
	 * "023" Time Recovery Configuration
	 * Get UTC time from a stationary receiver.  Solve for time only.
	 * This should improve the time resolution dramatically.
	 */
	mx4200_send(peer, "%s,%03d,%c,%c,%c,%d,%d,%d,", pmvxg,
	    PMVXG_S_TRECOVCONF,
	    'K',	/* known position: solve for time only */
	    'U',	/* synchronize to UTC */
	    'A',	/* always output a time pulse */
	    500,	/* max time error in ns */
	    0,		/* user bias in ns */
	    1);		/* output "830" sentences to control port */
	/* Multi-satellite mode */