359 lines
8.8 KiB
C
359 lines
8.8 KiB
C
/*
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* refclock_trak - clock driver for the TRAK 8810 GPS Station Clock
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*
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* Tomoaki TSURUOKA <tsuruoka@nc.fukuoka-u.ac.jp>
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* original version Dec, 1993
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* revised version Sep, 1994 for ntp3.4e or later
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*/
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#ifdef HAVE_CONFIG_H
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#include <config.h>
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#endif
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#if defined(REFCLOCK) && defined(CLOCK_TRAK) && defined(PPS)
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#include "ntpd.h"
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#include "ntp_io.h"
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#include "ntp_refclock.h"
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#include "ntp_stdlib.h"
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#include "ntp_unixtime.h"
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#include <stdio.h>
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#include <ctype.h>
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#ifdef HAVE_SYS_TERMIOS_H
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# include <sys/termios.h>
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#endif
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#ifdef HAVE_SYS_PPSCLOCK_H
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# include <sys/ppsclock.h>
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#endif
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/*
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* This driver supports the TRAK 8810/8820 GPS Station Clock. The claimed
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* accuracy at the 1-pps output is 200-300 ns relative to the broadcast
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* signal; however, in most cases the actual accuracy is limited by the
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* precision of the timecode and the latencies of the serial interface
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* and operating system.
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*
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* For best accuracy, this radio requires the LDISC_ACTS line
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* discipline, which captures a timestamp at the '*' on-time character
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* of the timecode. Using this discipline the jitter is in the order of
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* 1 ms and systematic error about 0.5 ms. If unavailable, the buffer
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* timestamp is used, which is captured at the \r ending the timecode
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* message. This introduces a systematic error of 23 character times, or
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* about 24 ms at 9600 bps, together with a jitter well over 8 ms on Sun
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* IPC-class machines.
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*
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* Using the memus, the radio should be set for 9600 bps, one stop bit
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* and no parity. It should be set to operate in computer (no echo)
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* mode. The timecode format includes neither the year nor leap-second
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* warning. No provisions are included in this preliminary version of
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* the driver to read and record detailed internal radio status.
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*
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* In operation, this driver sends a RQTS\r request to the radio at
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* initialization in order to put it in continuous time output mode. The
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* radio then sends the following message once each second:
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*
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* *RQTS U,ddd:hh:mm:ss.0,q<cr><lf>
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*
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* on-time = '*' * ddd = day of year
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* hh:mm:ss = hours, minutes, seconds
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* q = quality indicator (phase error), 0-6:
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* 0 > 20 us
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* 6 > 10 us
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* 5 > 1 us
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* 4 > 100 ns
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* 3 > 10 ns
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* 2 < 10 ns
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*
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* The alarm condition is indicated by '0' at Q, which means the radio
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* has a phase error than 20 usec relative to the broadcast time. The
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* absence of year, DST and leap-second warning in this format is also
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* alarming.
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*
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* The continuous time mode is disabled using the RQTX<cr> request,
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* following which the radio sends a RQTX DONE<cr><lf> response. In the
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* normal mode, other control and status requests are effective,
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* including the leap-second status request RQLS<cr>. The radio responds
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* wtih RQLS yy,mm,dd<cr><lf>, where yy,mm,dd are the year, month and
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* day. Presumably, this gives the epoch of the next leap second,
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* RQLS 00,00,00 if none is specified in the GPS message. Specified in
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* this form, the information is generally useless and is ignored by
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* the driver.
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*
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* Fudge Factors
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*
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* There are no special fudge factors other than the generic.
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*/
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/*
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* Interface definitions
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*/
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#define DEVICE "/dev/trak%d" /* device name and unit */
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#define SPEED232 B9600 /* uart speed (9600 baud) */
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#define PRECISION (-20) /* precision assumed (about 1 us) */
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#define REFID "GPS\0" /* reference ID */
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#define DESCRIPTION "TRACK 8810/8820 Station Clock" /* WRU */
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#define LENTRAK 24 /* timecode length */
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#define C_CTO "RQTS\r" /* start continuous time output */
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/*
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* Unit control structure
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*/
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struct trakunit {
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int polled; /* poll message flag */
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l_fp tstamp; /* timestamp of last poll */
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};
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/*
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* Function prototypes
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*/
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static int trak_start P((int, struct peer *));
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static void trak_shutdown P((int, struct peer *));
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static void trak_receive P((struct recvbuf *));
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static void trak_poll P((int, struct peer *));
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/*
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* Transfer vector
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*/
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struct refclock refclock_trak = {
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trak_start, /* start up driver */
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trak_shutdown, /* shut down driver */
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trak_poll, /* transmit poll message */
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noentry, /* not used (old trak_control) */
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noentry, /* initialize driver (not used) */
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noentry, /* not used (old trak_buginfo) */
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NOFLAGS /* not used */
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};
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/*
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* trak_start - open the devices and initialize data for processing
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*/
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static int
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trak_start(
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int unit,
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struct peer *peer
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)
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{
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register struct trakunit *up;
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struct refclockproc *pp;
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int fd;
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char device[20];
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/*
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* Open serial port. The LDISC_ACTS line discipline inserts a
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* timestamp following the "*" on-time character of the
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* timecode.
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*/
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(void)sprintf(device, DEVICE, unit);
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if (
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#ifdef PPS
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!(fd = refclock_open(device, SPEED232, LDISC_CLK))
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#else
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!(fd = refclock_open(device, SPEED232, 0))
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#endif /* PPS */
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)
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return (0);
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/*
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* Allocate and initialize unit structure
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*/
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if (!(up = (struct trakunit *)
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emalloc(sizeof(struct trakunit)))) {
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(void) close(fd);
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return (0);
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}
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memset((char *)up, 0, sizeof(struct trakunit));
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pp = peer->procptr;
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pp->io.clock_recv = trak_receive;
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pp->io.srcclock = (caddr_t)peer;
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pp->io.datalen = 0;
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pp->io.fd = fd;
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if (!io_addclock(&pp->io)) {
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(void) close(fd);
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free(up);
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return (0);
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}
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pp->unitptr = (caddr_t)up;
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/*
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* Initialize miscellaneous variables
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*/
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peer->precision = PRECISION;
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pp->clockdesc = DESCRIPTION;
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memcpy((char *)&pp->refid, REFID, 4);
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up->polled = 0;
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/*
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* Start continuous time output. If something breaks, fold the
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* tent and go home.
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*/
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if (write(pp->io.fd, C_CTO, sizeof(C_CTO)) != sizeof(C_CTO)) {
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refclock_report(peer, CEVNT_FAULT);
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(void) close(fd);
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free(up);
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return (0);
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}
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return (1);
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}
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/*
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* trak_shutdown - shut down the clock
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*/
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static void
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trak_shutdown(
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int unit,
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struct peer *peer
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)
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{
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register struct trakunit *up;
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struct refclockproc *pp;
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pp = peer->procptr;
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up = (struct trakunit *)pp->unitptr;
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io_closeclock(&pp->io);
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free(up);
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}
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/*
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* trak_receive - receive data from the serial interface
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*/
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static void
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trak_receive(
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struct recvbuf *rbufp
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)
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{
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register struct trakunit *up;
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struct refclockproc *pp;
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struct peer *peer;
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l_fp trtmp;
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char *dpt, *dpend;
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char qchar;
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#ifdef PPS
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struct ppsclockev ppsev;
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int request;
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#ifdef HAVE_CIOGETEV
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request = CIOGETEV;
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#endif
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#ifdef HAVE_TIOCGPPSEV
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request = TIOCGPPSEV;
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#endif
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#endif /* PPS */
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/*
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* Initialize pointers and read the timecode and timestamp. We
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* then chuck out everything, including runts, except one
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* message each poll interval.
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*/
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peer = (struct peer *)rbufp->recv_srcclock;
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pp = peer->procptr;
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up = (struct trakunit *)pp->unitptr;
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pp->lencode = refclock_gtlin(rbufp, pp->a_lastcode, BMAX,
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&pp->lastrec);
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/*
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* We get a buffer and timestamp following the '*' on-time
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* character. If a valid timestamp, we use that in place of the
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* buffer timestamp and edit out the timestamp for prettyprint
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* billboards.
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*/
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dpt = pp->a_lastcode;
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dpend = dpt + pp->lencode;
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if (*dpt == '*' && buftvtots(dpt + 1, &trtmp)) {
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if (trtmp.l_i == pp->lastrec.l_i || trtmp.l_i ==
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pp->lastrec.l_i + 1) {
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pp->lastrec = trtmp;
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dpt += 9;
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while (dpt < dpend) {
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*(dpt - 8) = *dpt;
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++dpt;
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}
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}
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}
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if (up->polled == 0) return;
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up->polled = 0;
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#ifndef PPS
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get_systime(&up->tstamp);
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#endif
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record_clock_stats(&peer->srcadr, pp->a_lastcode);
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#ifdef DEBUG
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if (debug)
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printf("trak: timecode %d %s\n", pp->lencode,
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pp->a_lastcode);
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#endif
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/*
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* We get down to business, check the timecode format and decode
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* its contents. If the timecode has invalid length or is not in
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* proper format, we declare bad format and exit.
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*/
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if (pp->lencode < LENTRAK) {
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refclock_report(peer, CEVNT_BADREPLY);
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return;
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}
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/*
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* Timecode format: "*RQTS U,ddd:hh:mm:ss.0,q"
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*/
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if (sscanf(pp->a_lastcode, "*RQTS U,%3d:%2d:%2d:%2d.0,%c",
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&pp->day, &pp->hour, &pp->minute, &pp->second, &qchar) != 5) {
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refclock_report(peer, CEVNT_BADREPLY);
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return;
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}
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/*
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* Decode quality and leap characters. If unsynchronized, set
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* the leap bits accordingly and exit.
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*/
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if (qchar == '0') {
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pp->leap = LEAP_NOTINSYNC;
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return;
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}
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#ifdef PPS
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if(ioctl(fdpps,request,(caddr_t) &ppsev) >=0) {
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ppsev.tv.tv_sec += (u_int32) JAN_1970;
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TVTOTS(&ppsev.tv,&up->tstamp);
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}
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#endif /* PPS */
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/* record the last ppsclock event time stamp */
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pp->lastrec = up->tstamp;
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if (!refclock_process(pp)) {
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refclock_report(peer, CEVNT_BADTIME);
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return;
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}
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refclock_receive(peer);
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}
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/*
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* trak_poll - called by the transmit procedure
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*/
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static void
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trak_poll(
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int unit,
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struct peer *peer
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)
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{
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register struct trakunit *up;
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struct refclockproc *pp;
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/*
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* We don't really do anything here, except arm the receiving
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* side to capture a sample and check for timeouts.
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*/
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pp = peer->procptr;
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up = (struct trakunit *)pp->unitptr;
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if (up->polled)
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refclock_report(peer, CEVNT_TIMEOUT);
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pp->polls++;
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up->polled = 1;
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}
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#else
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int refclock_trak_bs;
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#endif /* REFCLOCK */
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