diff options
Diffstat (limited to 'ntpd/refclock_arbiter.c')
| -rw-r--r-- | ntpd/refclock_arbiter.c | 429 |
1 files changed, 429 insertions, 0 deletions
diff --git a/ntpd/refclock_arbiter.c b/ntpd/refclock_arbiter.c new file mode 100644 index 000000000000..cf5f92f1f5be --- /dev/null +++ b/ntpd/refclock_arbiter.c @@ -0,0 +1,429 @@ +/* + * 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) and elevation (LH) (meters) 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. + */ + +/* + * 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 30 /* max length of status string */ +#define MAXPOS 70 /* 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; /* synchronization indicator */ + + /* + * 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, pp->a_lastcode, 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 commant. + */ + if (!strncmp(pp->a_lastcode, "TQ", 2)) { + up->qualchar = pp->a_lastcode[2]; + write(pp->io.fd, "SR", 2); + } else if (!strncmp(pp->a_lastcode, "SR", 2)) { + strcpy(up->status, pp->a_lastcode + 2); + if (pp->sloppyclockflag & CLK_FLAG4) + write(pp->io.fd, "LA", 2); + else { + write(pp->io.fd, "B5", 2); + up->tcswitch++; + } + } else if (!strncmp(pp->a_lastcode, "LA", 2)) { + strcpy(up->latlon, pp->a_lastcode + 2); + write(pp->io.fd, "LO", 2); + } else if (!strncmp(pp->a_lastcode, "LO", 2)) { + strcat(up->latlon, " "); + strcat(up->latlon, pp->a_lastcode + 2); + write(pp->io.fd, "LH", 2); + } else if (!strncmp(pp->a_lastcode, "LH", 2)) { + strcat(up->latlon, " "); + strcat(up->latlon, pp->a_lastcode + 2); + write(pp->io.fd, "DB", 2); + } else if (!strncmp(pp->a_lastcode, "DB", 2)) { + strcat(up->latlon, " "); + strcat(up->latlon, pp->a_lastcode + 2); + record_clock_stats(&peer->srcadr, up->latlon); + write(pp->io.fd, "B5", 2); + up->tcswitch++; + } + return; + } + pp->lencode = temp; + + /* + * 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. + */ + if (pp->lencode == LENARB) { + /* + * Timecode format B5: "i yy ddd hh:mm:ss.000 " + */ + pp->a_lastcode[LENARB - 2] = up->qualchar; + strcat(pp->a_lastcode, up->status); + 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; + } + } else { + write(pp->io.fd, "B0", 2); + return; + } + up->tcswitch++; + + /* + * We decode the clock dispersion from the time quality + * character. + */ + switch (up->qualchar) { + + case '0': /* locked, max accuracy */ + pp->disp = 1e-7; + 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; +#ifdef DEBUG + if (debug) + printf("arbiter: timecode %d %s\n", pp->lencode, + pp->a_lastcode); +#endif + if (up->tcswitch >= NSTAGE) + write(pp->io.fd, "B0", 2); + + /* + * Process the new sample in the median filter and determine the + * timecode timestamp. + */ + if (!refclock_process(pp)) + refclock_report(peer, CEVNT_BADTIME); +} + + +/* + * 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. If nothing is + * heard from the clock for two polls, declare a timeout and + * keep going. + */ + pp = peer->procptr; + up = (struct arbunit *)pp->unitptr; + up->tcswitch = 0; + if (write(pp->io.fd, "TQ", 2) != 2) { + refclock_report(peer, CEVNT_FAULT); + } else + pp->polls++; + if (pp->coderecv == pp->codeproc) { + refclock_report(peer, CEVNT_TIMEOUT); + return; + } + pp->lastref = pp->lastrec; + refclock_receive(peer); + record_clock_stats(&peer->srcadr, pp->a_lastcode); +} + +#else +int refclock_arbiter_bs; +#endif /* REFCLOCK */ |