/contrib/ntp/ntpd/refclock_arbiter.c
https://bitbucket.org/freebsd/freebsd-head/ · C · 453 lines · 241 code · 50 blank · 162 comment · 38 complexity · 219ed0ce806246946ecbc80f3b742436 MD5 · raw file
- /*
- * refclock_arbiter - clock driver for Arbiter 1088A/B Satellite
- * Controlled Clock
- */
- #ifdef HAVE_CONFIG_H
- #include <config.h>
- #endif
- #if defined(REFCLOCK) && defined(CLOCK_ARBITER)
- #include "ntpd.h"
- #include "ntp_io.h"
- #include "ntp_refclock.h"
- #include "ntp_stdlib.h"
- #include <stdio.h>
- #include <ctype.h>
- /*
- * This driver supports the Arbiter 1088A/B Satellite Controlled Clock.
- * The claimed accuracy of this clock is 100 ns relative to the PPS
- * output when receiving four or more satellites.
- *
- * The receiver should be configured before starting the NTP daemon, in
- * order to establish reliable position and operating conditions. It
- * does not initiate surveying or hold mode. For use with NTP, the
- * daylight savings time feature should be disables (D0 command) and the
- * broadcast mode set to operate in UTC (BU command).
- *
- * The timecode format supported by this driver is selected by the poll
- * sequence "B5", which initiates a line in the following format to be
- * repeated once per second until turned off by the "B0" poll sequence.
- *
- * Format B5 (24 ASCII printing characters):
- *
- * <cr><lf>i yy ddd hh:mm:ss.000bbb
- *
- * on-time = <cr>
- * i = synchronization flag (' ' = locked, '?' = unlocked)
- * yy = year of century
- * ddd = day of year
- * hh:mm:ss = hours, minutes, seconds
- * .000 = fraction of second (not used)
- * bbb = tailing spaces for fill
- *
- * The alarm condition is indicated by a '?' at i, which indicates the
- * receiver is not synchronized. In normal operation, a line consisting
- * of the timecode followed by the time quality character (TQ) followed
- * by the receiver status string (SR) is written to the clockstats file.
- * The time quality character is encoded in IEEE P1344 standard:
- *
- * Format TQ (IEEE P1344 estimated worst-case time quality)
- *
- * 0 clock locked, maximum accuracy
- * F clock failure, time not reliable
- * 4 clock unlocked, accuracy < 1 us
- * 5 clock unlocked, accuracy < 10 us
- * 6 clock unlocked, accuracy < 100 us
- * 7 clock unlocked, accuracy < 1 ms
- * 8 clock unlocked, accuracy < 10 ms
- * 9 clock unlocked, accuracy < 100 ms
- * A clock unlocked, accuracy < 1 s
- * B clock unlocked, accuracy < 10 s
- *
- * The status string is encoded as follows:
- *
- * Format SR (25 ASCII printing characters)
- *
- * V=vv S=ss T=t P=pdop E=ee
- *
- * vv = satellites visible
- * ss = relative signal strength
- * t = satellites tracked
- * pdop = position dilution of precision (meters)
- * ee = hardware errors
- *
- * If flag4 is set, an additional line consisting of the receiver
- * latitude (LA), longitude (LO), elevation (LH) (meters), and data
- * buffer (DB) is written to this file. If channel B is enabled for
- * deviation mode and connected to a 1-PPS signal, the last two numbers
- * on the line are the deviation and standard deviation averaged over
- * the last 15 seconds.
- *
- * PPS calibration fudge time1 .001240
- */
- /*
- * Interface definitions
- */
- #define DEVICE "/dev/gps%d" /* device name and unit */
- #define SPEED232 B9600 /* uart speed (9600 baud) */
- #define PRECISION (-20) /* precision assumed (about 1 us) */
- #define REFID "GPS " /* reference ID */
- #define DESCRIPTION "Arbiter 1088A/B GPS Receiver" /* WRU */
- #define LENARB 24 /* format B5 timecode length */
- #define MAXSTA 40 /* max length of status string */
- #define MAXPOS 80 /* max length of position string */
- /*
- * ARB unit control structure
- */
- struct arbunit {
- l_fp laststamp; /* last receive timestamp */
- int tcswitch; /* timecode switch/counter */
- char qualchar; /* IEEE P1344 quality (TQ command) */
- char status[MAXSTA]; /* receiver status (SR command) */
- char latlon[MAXPOS]; /* receiver position (lat/lon/alt) */
- };
- /*
- * Function prototypes
- */
- static int arb_start P((int, struct peer *));
- static void arb_shutdown P((int, struct peer *));
- static void arb_receive P((struct recvbuf *));
- static void arb_poll P((int, struct peer *));
- /*
- * Transfer vector
- */
- struct refclock refclock_arbiter = {
- arb_start, /* start up driver */
- arb_shutdown, /* shut down driver */
- arb_poll, /* transmit poll message */
- noentry, /* not used (old arb_control) */
- noentry, /* initialize driver (not used) */
- noentry, /* not used (old arb_buginfo) */
- NOFLAGS /* not used */
- };
- /*
- * arb_start - open the devices and initialize data for processing
- */
- static int
- arb_start(
- int unit,
- struct peer *peer
- )
- {
- register struct arbunit *up;
- struct refclockproc *pp;
- int fd;
- char device[20];
- /*
- * Open serial port. Use CLK line discipline, if available.
- */
- (void)sprintf(device, DEVICE, unit);
- if (!(fd = refclock_open(device, SPEED232, LDISC_CLK)))
- return (0);
- /*
- * Allocate and initialize unit structure
- */
- if (!(up = (struct arbunit *)emalloc(sizeof(struct arbunit)))) {
- (void) close(fd);
- return (0);
- }
- memset((char *)up, 0, sizeof(struct arbunit));
- pp = peer->procptr;
- pp->io.clock_recv = arb_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);
- write(pp->io.fd, "B0", 2);
- return (1);
- }
- /*
- * arb_shutdown - shut down the clock
- */
- static void
- arb_shutdown(
- int unit,
- struct peer *peer
- )
- {
- register struct arbunit *up;
- struct refclockproc *pp;
- pp = peer->procptr;
- up = (struct arbunit *)pp->unitptr;
- io_closeclock(&pp->io);
- free(up);
- }
- /*
- * arb_receive - receive data from the serial interface
- */
- static void
- arb_receive(
- struct recvbuf *rbufp
- )
- {
- register struct arbunit *up;
- struct refclockproc *pp;
- struct peer *peer;
- l_fp trtmp;
- int temp;
- u_char syncchar; /* synch indicator */
- char tbuf[BMAX]; /* temp buffer */
- /*
- * Initialize pointers and read the timecode and timestamp
- */
- peer = (struct peer *)rbufp->recv_srcclock;
- pp = peer->procptr;
- up = (struct arbunit *)pp->unitptr;
- temp = refclock_gtlin(rbufp, tbuf, BMAX, &trtmp);
- /*
- * Note we get a buffer and timestamp for both a <cr> and <lf>,
- * but only the <cr> timestamp is retained. The program first
- * sends a TQ and expects the echo followed by the time quality
- * character. It then sends a B5 starting the timecode broadcast
- * and expects the echo followed some time later by the on-time
- * character <cr> and then the <lf> beginning the timecode
- * itself. Finally, at the <cr> beginning the next timecode at
- * the next second, the program sends a B0 shutting down the
- * timecode broadcast.
- *
- * If flag4 is set, the program snatches the latitude, longitude
- * and elevation and writes it to the clockstats file.
- */
- if (temp == 0)
- return;
- pp->lastrec = up->laststamp;
- up->laststamp = trtmp;
- if (temp < 3)
- return;
- if (up->tcswitch == 0) {
- /*
- * Collect statistics. If nothing is recogized, just
- * ignore; sometimes the clock doesn't stop spewing
- * timecodes for awhile after the B0 command.
- *
- * If flag4 is not set, send TQ, SR, B5. If flag4 is
- * sset, send TQ, SR, LA, LO, LH, DB, B5. When the
- * median filter is full, send B0.
- */
- if (!strncmp(tbuf, "TQ", 2)) {
- up->qualchar = tbuf[2];
- write(pp->io.fd, "SR", 2);
- return;
- } else if (!strncmp(tbuf, "SR", 2)) {
- strcpy(up->status, tbuf + 2);
- if (pp->sloppyclockflag & CLK_FLAG4)
- write(pp->io.fd, "LA", 2);
- else
- write(pp->io.fd, "B5", 2);
- return;
- } else if (!strncmp(tbuf, "LA", 2)) {
- strcpy(up->latlon, tbuf + 2);
- write(pp->io.fd, "LO", 2);
- return;
- } else if (!strncmp(tbuf, "LO", 2)) {
- strcat(up->latlon, " ");
- strcat(up->latlon, tbuf + 2);
- write(pp->io.fd, "LH", 2);
- return;
- } else if (!strncmp(tbuf, "LH", 2)) {
- strcat(up->latlon, " ");
- strcat(up->latlon, tbuf + 2);
- write(pp->io.fd, "DB", 2);
- return;
- } else if (!strncmp(tbuf, "DB", 2)) {
- strcat(up->latlon, " ");
- strcat(up->latlon, tbuf + 2);
- record_clock_stats(&peer->srcadr, up->latlon);
- #ifdef DEBUG
- if (debug)
- printf("arbiter: %s\n", up->latlon);
- #endif
- write(pp->io.fd, "B5", 2);
- }
- }
- /*
- * We get down to business, check the timecode format and decode
- * its contents. If the timecode has valid length, but not in
- * proper format, we declare bad format and exit. If the
- * timecode has invalid length, which sometimes occurs when the
- * B0 amputates the broadcast, we just quietly steal away. Note
- * that the time quality character and receiver status string is
- * tacked on the end for clockstats display.
- */
- up->tcswitch++;
- if (up->tcswitch <= 1 || temp < LENARB)
- return;
- /*
- * Timecode format B5: "i yy ddd hh:mm:ss.000 "
- */
- strncpy(pp->a_lastcode, tbuf, BMAX);
- pp->a_lastcode[LENARB - 2] = up->qualchar;
- strcat(pp->a_lastcode, up->status);
- pp->lencode = strlen(pp->a_lastcode);
- syncchar = ' ';
- if (sscanf(pp->a_lastcode, "%c%2d %3d %2d:%2d:%2d",
- &syncchar, &pp->year, &pp->day, &pp->hour,
- &pp->minute, &pp->second) != 6) {
- refclock_report(peer, CEVNT_BADREPLY);
- write(pp->io.fd, "B0", 2);
- return;
- }
- /*
- * We decode the clock dispersion from the time quality
- * character.
- */
- switch (up->qualchar) {
- case '0': /* locked, max accuracy */
- pp->disp = 1e-7;
- pp->lastref = pp->lastrec;
- break;
- case '4': /* unlock accuracy < 1 us */
- pp->disp = 1e-6;
- break;
- case '5': /* unlock accuracy < 10 us */
- pp->disp = 1e-5;
- break;
- case '6': /* unlock accuracy < 100 us */
- pp->disp = 1e-4;
- break;
- case '7': /* unlock accuracy < 1 ms */
- pp->disp = .001;
- break;
- case '8': /* unlock accuracy < 10 ms */
- pp->disp = .01;
- break;
- case '9': /* unlock accuracy < 100 ms */
- pp->disp = .1;
- break;
- case 'A': /* unlock accuracy < 1 s */
- pp->disp = 1;
- break;
- case 'B': /* unlock accuracy < 10 s */
- pp->disp = 10;
- break;
- case 'F': /* clock failure */
- pp->disp = MAXDISPERSE;
- refclock_report(peer, CEVNT_FAULT);
- write(pp->io.fd, "B0", 2);
- return;
- default:
- pp->disp = MAXDISPERSE;
- refclock_report(peer, CEVNT_BADREPLY);
- write(pp->io.fd, "B0", 2);
- return;
- }
- if (syncchar != ' ')
- pp->leap = LEAP_NOTINSYNC;
- else
- pp->leap = LEAP_NOWARNING;
- /*
- * Process the new sample in the median filter and determine the
- * timecode timestamp.
- */
- if (!refclock_process(pp))
- refclock_report(peer, CEVNT_BADTIME);
- else if (peer->disp > MAXDISTANCE)
- refclock_receive(peer);
- if (up->tcswitch >= MAXSTAGE) {
- write(pp->io.fd, "B0", 2);
- }
- }
- /*
- * arb_poll - called by the transmit procedure
- */
- static void
- arb_poll(
- int unit,
- struct peer *peer
- )
- {
- register struct arbunit *up;
- struct refclockproc *pp;
- /*
- * Time to poll the clock. The Arbiter clock responds to a "B5"
- * by returning a timecode in the format specified above.
- * Transmission occurs once per second, unless turned off by a
- * "B0". Note there is no checking on state, since this may not
- * be the only customer reading the clock. Only one customer
- * need poll the clock; all others just listen in.
- */
- pp = peer->procptr;
- up = (struct arbunit *)pp->unitptr;
- pp->polls++;
- up->tcswitch = 0;
- if (write(pp->io.fd, "TQ", 2) != 2)
- refclock_report(peer, CEVNT_FAULT);
- /*
- * Process median filter samples. If none received, declare a
- * timeout and keep going.
- */
- if (pp->coderecv == pp->codeproc) {
- refclock_report(peer, CEVNT_TIMEOUT);
- return;
- }
- refclock_receive(peer);
- record_clock_stats(&peer->srcadr, pp->a_lastcode);
- #ifdef DEBUG
- if (debug)
- printf("arbiter: timecode %d %s\n",
- pp->lencode, pp->a_lastcode);
- #endif
- }
- #else
- int refclock_arbiter_bs;
- #endif /* REFCLOCK */