/* * 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 ntp3.4e or later */ #ifdef HAVE_CONFIG_H #include <config.h> #endif #if defined(REFCLOCK) && defined(CLOCK_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 LENTRAK 24 /* timecode length */ #define C_CTO "RQTS\r" /* start continuous time output */ /* * 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( 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); if ( #ifdef PPS !(fd = refclock_open(device, SPEED232, LDISC_CLK)) #else !(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( 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( 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; ++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; } #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; if (!refclock_process(pp)) { refclock_report(peer, CEVNT_BADTIME); return; } refclock_receive(peer); } /* * trak_poll - called by the transmit procedure */ static void trak_poll( 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 int refclock_trak_bs; #endif /* REFCLOCK */