NetBSD/usr.sbin/xntp/xntpd/refclock_trak.c

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/* $NetBSD: refclock_trak.c,v 1.4 1998/08/12 14:11:56 christos Exp $ */
/*
* refclock_trak - clock driver for the TRAK 8810 GPS Station Clock
*
* Tomoaki TSURUOKA <tsuruoka@nc.fukuoka-u.ac.jp>
* original version Dec, 1993
* revised version Sep, 1994 for xntp3.4e or later
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#if defined(REFCLOCK) && defined(TRAK)
#include <stdio.h>
#include <ctype.h>
#include <sys/time.h>
#include "ntpd.h"
#include "ntp_io.h"
#include "ntp_refclock.h"
#include "ntp_stdlib.h"
#include "ntp_unixtime.h"
#ifdef PPS
#include <sys/ppsclock.h>
#endif /* PPS */
/*
* This driver supports the TRAK 8810/8820 GPS Station Clock. The claimed
* accuracy at the 1-pps output is 200-300 ns relative to the broadcast
* signal; however, in most cases the actual accuracy is limited by the
* precision of the timecode and the latencies of the serial interface
* and operating system.
*
* For best accuracy, this radio requires the LDISC_ACTS line
* discipline, which captures a timestamp at the '*' on-time character
* of the timecode. Using this discipline the jitter is in the order of
* 1 ms and systematic error about 0.5 ms. If unavailable, the buffer
* timestamp is used, which is captured at the \r ending the timecode
* message. This introduces a systematic error of 23 character times, or
* about 24 ms at 9600 bps, together with a jitter well over 8 ms on Sun
* IPC-class machines.
*
* Using the memus, the radio should be set for 9600 bps, one stop bit
* and no parity. It should be set to operate in computer (no echo)
* mode. The timecode format includes neither the year nor leap-second
* warning. No provisions are included in this preliminary version of
* the driver to read and record detailed internal radio status.
*
* In operation, this driver sends a RQTS\r request to the radio at
* initialization in order to put it in continuous time output mode. The
* radio then sends the following message once each second:
*
* *RQTS U,ddd:hh:mm:ss.0,q<cr><lf>
*
* on-time = '*' * ddd = day of year
* hh:mm:ss = hours, minutes, seconds
* q = quality indicator (phase error), 0-6:
* 0 > 20 us
* 6 > 10 us
* 5 > 1 us
* 4 > 100 ns
* 3 > 10 ns
* 2 < 10 ns
*
* The alarm condition is indicated by '0' at Q, which means the radio
* has a phase error than 20 usec relative to the broadcast time. The
* absence of year, DST and leap-second warning in this format is also
* alarming.
*
* The continuous time mode is disabled using the RQTX<cr> request,
* following which the radio sends a RQTX DONE<cr><lf> response. In the
* normal mode, other control and status requests are effective,
* including the leap-second status request RQLS<cr>. The radio responds
* wtih RQLS yy,mm,dd<cr><lf>, where yy,mm,dd are the year, month and
* day. Presumably, this gives the epoch of the next leap second,
* RQLS 00,00,00 if none is specified in the GPS message. Specified in
* this form, the information is generally useless and is ignored by
* the driver.
*
* Fudge Factors
*
* There are no special fudge factors other than the generic.
*/
/*
* Interface definitions
*/
#define DEVICE "/dev/trak%d" /* device name and unit */
#define SPEED232 B9600 /* uart speed (9600 baud) */
#define PRECISION (-20) /* precision assumed (about 1 us) */
#define REFID "GPS\0" /* reference ID */
#define DESCRIPTION "TRACK 8810/8820 Station Clock" /* WRU */
#define NSAMPLES 3 /* stages of median filter */
#define LENTRAK 24 /* timecode length */
#define C_CTO "RQTS\r" /* start continuous time output */
/*
* Imported from ntp_timer module
*/
extern u_long current_time; /* current time (s) */
#ifdef PPS
/*
* Imported from ntp_loopfilter module
*/
extern int fdpps; /* pps file descriptor */
#endif /* PPS */
/*
* Imported from ntpd module
*/
extern int debug; /* global debug flag */
/*
* Unit control structure
*/
struct trakunit {
int polled; /* poll message flag */
l_fp tstamp; /* timestamp of last poll */
};
/*
* Function prototypes
*/
static int trak_start P((int, struct peer *));
static void trak_shutdown P((int, struct peer *));
static void trak_receive P((struct recvbuf *));
static void trak_poll P((int, struct peer *));
/*
* Transfer vector
*/
struct refclock refclock_trak = {
trak_start, /* start up driver */
trak_shutdown, /* shut down driver */
trak_poll, /* transmit poll message */
noentry, /* not used (old trak_control) */
noentry, /* initialize driver (not used) */
noentry, /* not used (old trak_buginfo) */
NOFLAGS /* not used */
};
/*
* trak_start - open the devices and initialize data for processing
*/
static int
trak_start(unit, peer)
int unit;
struct peer *peer;
{
register struct trakunit *up;
struct refclockproc *pp;
int fd;
char device[20];
/*
* Open serial port. The LDISC_ACTS line discipline inserts a
* timestamp following the "*" on-time character of the
* timecode.
*/
(void)sprintf(device, DEVICE, unit);
#ifdef PPS
if (!(fd = refclock_open(device, SPEED232, LDISC_CLK)))
#else
if (!(fd = refclock_open(device, SPEED232, 0)))
#endif /* PPS */
return (0);
/*
* Allocate and initialize unit structure
*/
if (!(up = (struct trakunit *)
emalloc(sizeof(struct trakunit)))) {
(void) close(fd);
return (0);
}
memset((char *)up, 0, sizeof(struct trakunit));
pp = peer->procptr;
pp->io.clock_recv = trak_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);
up->polled = 0;
/*
* Start continuous time output. If something breaks, fold the
* tent and go home.
*/
if (write(pp->io.fd, C_CTO, sizeof(C_CTO)) != sizeof(C_CTO)) {
refclock_report(peer, CEVNT_FAULT);
(void) close(fd);
free(up);
return (0);
}
return (1);
}
/*
* trak_shutdown - shut down the clock
*/
static void
trak_shutdown(unit, peer)
int unit;
struct peer *peer;
{
register struct trakunit *up;
struct refclockproc *pp;
pp = peer->procptr;
up = (struct trakunit *)pp->unitptr;
io_closeclock(&pp->io);
free(up);
}
/*
* trak_receive - receive data from the serial interface
*/
static void
trak_receive(rbufp)
struct recvbuf *rbufp;
{
register struct trakunit *up;
struct refclockproc *pp;
struct peer *peer;
l_fp trtmp;
char *dpt, *dpend;
char qchar;
#ifdef PPS
struct ppsclockev ppsev;
#endif /* PPS */
/*
* Initialize pointers and read the timecode and timestamp. We
* then chuck out everything, including runts, except one
* message each poll interval.
*/
peer = (struct peer *)rbufp->recv_srcclock;
pp = peer->procptr;
up = (struct trakunit *)pp->unitptr;
pp->lencode = refclock_gtlin(rbufp, pp->a_lastcode, BMAX,
&pp->lastrec);
/*
* We get a buffer and timestamp following the '*' on-time
* character. If a valid timestamp, we use that in place of the
* buffer timestamp and edit out the timestamp for prettyprint
* billboards.
*/
dpt = pp->a_lastcode;
dpend = dpt + pp->lencode;
if (*dpt == '*' && buftvtots(dpt + 1, &trtmp)) {
if (trtmp.l_i == pp->lastrec.l_i || trtmp.l_i ==
pp->lastrec.l_i + 1) {
pp->lastrec = trtmp;
dpt += 9;
while (dpt < dpend)
*(dpt - 8) = *dpt++;
}
}
if (up->polled == 0) return;
up->polled = 0;
#ifndef PPS
get_systime(&up->tstamp);
#endif
record_clock_stats(&peer->srcadr, pp->a_lastcode);
#ifdef DEBUG
if (debug)
printf("trak: timecode %d %s\n", pp->lencode,
pp->a_lastcode);
#endif
/*
* We get down to business, check the timecode format and decode
* its contents. If the timecode has invalid length or is not in
* proper format, we declare bad format and exit.
*/
if (pp->lencode < LENTRAK) {
refclock_report(peer, CEVNT_BADREPLY);
return;
}
/*
* Timecode format: "*RQTS U,ddd:hh:mm:ss.0,q"
*/
if (sscanf(pp->a_lastcode, "*RQTS U,%3d:%2d:%2d:%2d.0,%c",
&pp->day, &pp->hour, &pp->minute, &pp->second, &qchar) != 5) {
refclock_report(peer, CEVNT_BADREPLY);
return;
}
/*
* Decode quality and leap characters. If unsynchronized, set
* the leap bits accordingly and exit.
*/
if (qchar == '0') {
pp->leap = LEAP_NOTINSYNC;
return;
}
else {
pp->leap = 0;
pp->lasttime = current_time;
}
#ifdef PPS
if(ioctl(fdpps,CIOGETEV,(caddr_t) &ppsev) >=0) {
ppsev.tv.tv_sec += (u_int32) JAN_1970;
TVTOTS(&ppsev.tv,&up->tstamp);
}
#endif /* PPS */
/* record the last ppsclock event time stamp */
pp->lastrec = up->tstamp;
/*
* Process the new sample in the median filter and determine the
* reference clock offset and dispersion. We use lastrec as both
* the reference time and receive time in order to avoid being
* cute, like setting the reference time later than the receive
* time, which may cause a paranoid protocol module to chuck out
* the data.
*/
if (!refclock_process(pp, NSAMPLES, NSAMPLES)) {
refclock_report(peer, CEVNT_BADTIME);
return;
}
refclock_receive(peer, &pp->offset, 0, pp->dispersion,
&pp->lastrec, &pp->lastrec, pp->leap);
}
/*
* trak_poll - called by the transmit procedure
*/
static void
trak_poll(unit, peer)
int unit;
struct peer *peer;
{
register struct trakunit *up;
struct refclockproc *pp;
/*
* We don't really do anything here, except arm the receiving
* side to capture a sample and check for timeouts.
*/
pp = peer->procptr;
up = (struct trakunit *)pp->unitptr;
if (up->polled)
refclock_report(peer, CEVNT_TIMEOUT);
pp->polls++;
up->polled = 1;
}
#else /* not (REFCLOCK && TRAK) */
int refclock_track_bs;
#endif /* not (REFCLOCK && TRAK) */