/contrib/ntp/ntpd/refclock_hpgps.c
https://bitbucket.org/freebsd/freebsd-head/ · C · 619 lines · 358 code · 67 blank · 194 comment · 78 complexity · 8470fef4c27f1d2d8329376550af9cef MD5 · raw file
- /*
- * refclock_hpgps - clock driver for HP 58503A GPS receiver
- */
- #ifdef HAVE_CONFIG_H
- # include <config.h>
- #endif
- #if defined(REFCLOCK) && defined(CLOCK_HPGPS)
- #include "ntpd.h"
- #include "ntp_io.h"
- #include "ntp_refclock.h"
- #include "ntp_stdlib.h"
- #include <stdio.h>
- #include <ctype.h>
- /* Version 0.1 April 1, 1995
- * 0.2 April 25, 1995
- * tolerant of missing timecode response prompt and sends
- * clear status if prompt indicates error;
- * can use either local time or UTC from receiver;
- * can get receiver status screen via flag4
- *
- * WARNING!: This driver is UNDER CONSTRUCTION
- * Everything in here should be treated with suspicion.
- * If it looks wrong, it probably is.
- *
- * Comments and/or questions to: Dave Vitanye
- * Hewlett Packard Company
- * dave@scd.hp.com
- * (408) 553-2856
- *
- * Thanks to the author of the PST driver, which was the starting point for
- * this one.
- *
- * This driver supports the HP 58503A Time and Frequency Reference Receiver.
- * This receiver uses HP SmartClock (TM) to implement an Enhanced GPS receiver.
- * The receiver accuracy when locked to GPS in normal operation is better
- * than 1 usec. The accuracy when operating in holdover is typically better
- * than 10 usec. per day.
- *
- * The same driver also handles the HP Z3801A which is available surplus
- * from the cell phone industry. It's popular with hams.
- * It needs a different line setup: 19200 baud, 7 data bits, odd parity
- * That is selected by adding "mode 1" to the server line in ntp.conf
- * HP Z3801A code from Jeff Mock added by Hal Murray, Sep 2005
- *
- *
- * The receiver should be operated with factory default settings.
- * Initial driver operation: expects the receiver to be already locked
- * to GPS, configured and able to output timecode format 2 messages.
- *
- * The driver uses the poll sequence :PTIME:TCODE? to get a response from
- * the receiver. The receiver responds with a timecode string of ASCII
- * printing characters, followed by a <cr><lf>, followed by a prompt string
- * issued by the receiver, in the following format:
- * T#yyyymmddhhmmssMFLRVcc<cr><lf>scpi >
- *
- * The driver processes the response at the <cr> and <lf>, so what the
- * driver sees is the prompt from the previous poll, followed by this
- * timecode. The prompt from the current poll is (usually) left unread until
- * the next poll. So (except on the very first poll) the driver sees this:
- *
- * scpi > T#yyyymmddhhmmssMFLRVcc<cr><lf>
- *
- * The T is the on-time character, at 980 msec. before the next 1PPS edge.
- * The # is the timecode format type. We look for format 2.
- * Without any of the CLK or PPS stuff, then, the receiver buffer timestamp
- * at the <cr> is 24 characters later, which is about 25 msec. at 9600 bps,
- * so the first approximation for fudge time1 is nominally -0.955 seconds.
- * This number probably needs adjusting for each machine / OS type, so far:
- * -0.955000 on an HP 9000 Model 712/80 HP-UX 9.05
- * -0.953175 on an HP 9000 Model 370 HP-UX 9.10
- *
- * This receiver also provides a 1PPS signal, but I haven't figured out
- * how to deal with any of the CLK or PPS stuff yet. Stay tuned.
- *
- */
- /*
- * Fudge Factors
- *
- * Fudge time1 is used to accomodate the timecode serial interface adjustment.
- * Fudge flag4 can be set to request a receiver status screen summary, which
- * is recorded in the clockstats file.
- */
- /*
- * Interface definitions
- */
- #define DEVICE "/dev/hpgps%d" /* device name and unit */
- #define SPEED232 B9600 /* uart speed (9600 baud) */
- #define SPEED232Z B19200 /* uart speed (19200 baud) */
- #define PRECISION (-10) /* precision assumed (about 1 ms) */
- #define REFID "GPS\0" /* reference ID */
- #define DESCRIPTION "HP 58503A GPS Time and Frequency Reference Receiver"
- #define SMAX 23*80+1 /* for :SYSTEM:PRINT? status screen response */
- #define MTZONE 2 /* number of fields in timezone reply */
- #define MTCODET2 12 /* number of fields in timecode format T2 */
- #define NTCODET2 21 /* number of chars to checksum in format T2 */
- /*
- * Tables to compute the day of year from yyyymmdd timecode.
- * Viva la leap.
- */
- static int day1tab[] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
- static int day2tab[] = {31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
- /*
- * Unit control structure
- */
- struct hpgpsunit {
- int pollcnt; /* poll message counter */
- int tzhour; /* timezone offset, hours */
- int tzminute; /* timezone offset, minutes */
- int linecnt; /* set for expected multiple line responses */
- char *lastptr; /* pointer to receiver response data */
- char statscrn[SMAX]; /* receiver status screen buffer */
- };
- /*
- * Function prototypes
- */
- static int hpgps_start P((int, struct peer *));
- static void hpgps_shutdown P((int, struct peer *));
- static void hpgps_receive P((struct recvbuf *));
- static void hpgps_poll P((int, struct peer *));
- /*
- * Transfer vector
- */
- struct refclock refclock_hpgps = {
- hpgps_start, /* start up driver */
- hpgps_shutdown, /* shut down driver */
- hpgps_poll, /* transmit poll message */
- noentry, /* not used (old hpgps_control) */
- noentry, /* initialize driver */
- noentry, /* not used (old hpgps_buginfo) */
- NOFLAGS /* not used */
- };
- /*
- * hpgps_start - open the devices and initialize data for processing
- */
- static int
- hpgps_start(
- int unit,
- struct peer *peer
- )
- {
- register struct hpgpsunit *up;
- struct refclockproc *pp;
- int fd;
- char device[20];
- /*
- * Open serial port. Use CLK line discipline, if available.
- * Default is HP 58503A, mode arg selects HP Z3801A
- */
- (void)sprintf(device, DEVICE, unit);
- /* mode parameter to server config line shares ttl slot */
- if ((peer->ttl == 1)) {
- if (!(fd = refclock_open(device, SPEED232Z,
- LDISC_CLK | LDISC_7O1)))
- return (0);
- } else {
- if (!(fd = refclock_open(device, SPEED232, LDISC_CLK)))
- return (0);
- }
- /*
- * Allocate and initialize unit structure
- */
- if (!(up = (struct hpgpsunit *)
- emalloc(sizeof(struct hpgpsunit)))) {
- (void) close(fd);
- return (0);
- }
- memset((char *)up, 0, sizeof(struct hpgpsunit));
- pp = peer->procptr;
- pp->io.clock_recv = hpgps_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->tzhour = 0;
- up->tzminute = 0;
- *up->statscrn = '\0';
- up->lastptr = up->statscrn;
- up->pollcnt = 2;
- /*
- * Get the identifier string, which is logged but otherwise ignored,
- * and get the local timezone information
- */
- up->linecnt = 1;
- if (write(pp->io.fd, "*IDN?\r:PTIME:TZONE?\r", 20) != 20)
- refclock_report(peer, CEVNT_FAULT);
- return (1);
- }
- /*
- * hpgps_shutdown - shut down the clock
- */
- static void
- hpgps_shutdown(
- int unit,
- struct peer *peer
- )
- {
- register struct hpgpsunit *up;
- struct refclockproc *pp;
- pp = peer->procptr;
- up = (struct hpgpsunit *)pp->unitptr;
- io_closeclock(&pp->io);
- free(up);
- }
- /*
- * hpgps_receive - receive data from the serial interface
- */
- static void
- hpgps_receive(
- struct recvbuf *rbufp
- )
- {
- register struct hpgpsunit *up;
- struct refclockproc *pp;
- struct peer *peer;
- l_fp trtmp;
- char tcodechar1; /* identifies timecode format */
- char tcodechar2; /* identifies timecode format */
- char timequal; /* time figure of merit: 0-9 */
- char freqqual; /* frequency figure of merit: 0-3 */
- char leapchar; /* leapsecond: + or 0 or - */
- char servchar; /* request for service: 0 = no, 1 = yes */
- char syncchar; /* time info is invalid: 0 = no, 1 = yes */
- short expectedsm; /* expected timecode byte checksum */
- short tcodechksm; /* computed timecode byte checksum */
- int i,m,n;
- int month, day, lastday;
- char *tcp; /* timecode pointer (skips over the prompt) */
- char prompt[BMAX]; /* prompt in response from receiver */
- /*
- * Initialize pointers and read the receiver response
- */
- peer = (struct peer *)rbufp->recv_srcclock;
- pp = peer->procptr;
- up = (struct hpgpsunit *)pp->unitptr;
- *pp->a_lastcode = '\0';
- pp->lencode = refclock_gtlin(rbufp, pp->a_lastcode, BMAX, &trtmp);
- #ifdef DEBUG
- if (debug)
- printf("hpgps: lencode: %d timecode:%s\n",
- pp->lencode, pp->a_lastcode);
- #endif
- /*
- * If there's no characters in the reply, we can quit now
- */
- if (pp->lencode == 0)
- return;
- /*
- * If linecnt is greater than zero, we are getting information only,
- * such as the receiver identification string or the receiver status
- * screen, so put the receiver response at the end of the status
- * screen buffer. When we have the last line, write the buffer to
- * the clockstats file and return without further processing.
- *
- * If linecnt is zero, we are expecting either the timezone
- * or a timecode. At this point, also write the response
- * to the clockstats file, and go on to process the prompt (if any),
- * timezone, or timecode and timestamp.
- */
- if (up->linecnt-- > 0) {
- if ((int)(pp->lencode + 2) <= (SMAX - (up->lastptr - up->statscrn))) {
- *up->lastptr++ = '\n';
- (void)strcpy(up->lastptr, pp->a_lastcode);
- up->lastptr += pp->lencode;
- }
- if (up->linecnt == 0)
- record_clock_stats(&peer->srcadr, up->statscrn);
-
- return;
- }
- record_clock_stats(&peer->srcadr, pp->a_lastcode);
- pp->lastrec = trtmp;
-
- up->lastptr = up->statscrn;
- *up->lastptr = '\0';
- up->pollcnt = 2;
- /*
- * We get down to business: get a prompt if one is there, issue
- * a clear status command if it contains an error indication.
- * Next, check for either the timezone reply or the timecode reply
- * and decode it. If we don't recognize the reply, or don't get the
- * proper number of decoded fields, or get an out of range timezone,
- * or if the timecode checksum is bad, then we declare bad format
- * and exit.
- *
- * Timezone format (including nominal prompt):
- * scpi > -H,-M<cr><lf>
- *
- * Timecode format (including nominal prompt):
- * scpi > T2yyyymmddhhmmssMFLRVcc<cr><lf>
- *
- */
- (void)strcpy(prompt,pp->a_lastcode);
- tcp = strrchr(pp->a_lastcode,'>');
- if (tcp == NULL)
- tcp = pp->a_lastcode;
- else
- tcp++;
- prompt[tcp - pp->a_lastcode] = '\0';
- while ((*tcp == ' ') || (*tcp == '\t')) tcp++;
- /*
- * deal with an error indication in the prompt here
- */
- if (strrchr(prompt,'E') > strrchr(prompt,'s')){
- #ifdef DEBUG
- if (debug)
- printf("hpgps: error indicated in prompt: %s\n", prompt);
- #endif
- if (write(pp->io.fd, "*CLS\r\r", 6) != 6)
- refclock_report(peer, CEVNT_FAULT);
- }
- /*
- * make sure we got a timezone or timecode format and
- * then process accordingly
- */
- m = sscanf(tcp,"%c%c", &tcodechar1, &tcodechar2);
- if (m != 2){
- #ifdef DEBUG
- if (debug)
- printf("hpgps: no format indicator\n");
- #endif
- refclock_report(peer, CEVNT_BADREPLY);
- return;
- }
- switch (tcodechar1) {
- case '+':
- case '-':
- m = sscanf(tcp,"%d,%d", &up->tzhour, &up->tzminute);
- if (m != MTZONE) {
- #ifdef DEBUG
- if (debug)
- printf("hpgps: only %d fields recognized in timezone\n", m);
- #endif
- refclock_report(peer, CEVNT_BADREPLY);
- return;
- }
- if ((up->tzhour < -12) || (up->tzhour > 13) ||
- (up->tzminute < -59) || (up->tzminute > 59)){
- #ifdef DEBUG
- if (debug)
- printf("hpgps: timezone %d, %d out of range\n",
- up->tzhour, up->tzminute);
- #endif
- refclock_report(peer, CEVNT_BADREPLY);
- return;
- }
- return;
- case 'T':
- break;
- default:
- #ifdef DEBUG
- if (debug)
- printf("hpgps: unrecognized reply format %c%c\n",
- tcodechar1, tcodechar2);
- #endif
- refclock_report(peer, CEVNT_BADREPLY);
- return;
- } /* end of tcodechar1 switch */
- switch (tcodechar2) {
- case '2':
- m = sscanf(tcp,"%*c%*c%4d%2d%2d%2d%2d%2d%c%c%c%c%c%2hx",
- &pp->year, &month, &day, &pp->hour, &pp->minute, &pp->second,
- &timequal, &freqqual, &leapchar, &servchar, &syncchar,
- &expectedsm);
- n = NTCODET2;
- if (m != MTCODET2){
- #ifdef DEBUG
- if (debug)
- printf("hpgps: only %d fields recognized in timecode\n", m);
- #endif
- refclock_report(peer, CEVNT_BADREPLY);
- return;
- }
- break;
- default:
- #ifdef DEBUG
- if (debug)
- printf("hpgps: unrecognized timecode format %c%c\n",
- tcodechar1, tcodechar2);
- #endif
- refclock_report(peer, CEVNT_BADREPLY);
- return;
- } /* end of tcodechar2 format switch */
-
- /*
- * Compute and verify the checksum.
- * Characters are summed starting at tcodechar1, ending at just
- * before the expected checksum. Bail out if incorrect.
- */
- tcodechksm = 0;
- while (n-- > 0) tcodechksm += *tcp++;
- tcodechksm &= 0x00ff;
- if (tcodechksm != expectedsm) {
- #ifdef DEBUG
- if (debug)
- printf("hpgps: checksum %2hX doesn't match %2hX expected\n",
- tcodechksm, expectedsm);
- #endif
- refclock_report(peer, CEVNT_BADREPLY);
- return;
- }
- /*
- * Compute the day of year from the yyyymmdd format.
- */
- if (month < 1 || month > 12 || day < 1) {
- refclock_report(peer, CEVNT_BADTIME);
- return;
- }
- if ( ! isleap_4(pp->year) ) { /* Y2KFixes */
- /* not a leap year */
- if (day > day1tab[month - 1]) {
- refclock_report(peer, CEVNT_BADTIME);
- return;
- }
- for (i = 0; i < month - 1; i++) day += day1tab[i];
- lastday = 365;
- } else {
- /* a leap year */
- if (day > day2tab[month - 1]) {
- refclock_report(peer, CEVNT_BADTIME);
- return;
- }
- for (i = 0; i < month - 1; i++) day += day2tab[i];
- lastday = 366;
- }
- /*
- * Deal with the timezone offset here. The receiver timecode is in
- * local time = UTC + :PTIME:TZONE, so SUBTRACT the timezone values.
- * For example, Pacific Standard Time is -8 hours , 0 minutes.
- * Deal with the underflows and overflows.
- */
- pp->minute -= up->tzminute;
- pp->hour -= up->tzhour;
- if (pp->minute < 0) {
- pp->minute += 60;
- pp->hour--;
- }
- if (pp->minute > 59) {
- pp->minute -= 60;
- pp->hour++;
- }
- if (pp->hour < 0) {
- pp->hour += 24;
- day--;
- if (day < 1) {
- pp->year--;
- if ( isleap_4(pp->year) ) /* Y2KFixes */
- day = 366;
- else
- day = 365;
- }
- }
- if (pp->hour > 23) {
- pp->hour -= 24;
- day++;
- if (day > lastday) {
- pp->year++;
- day = 1;
- }
- }
- pp->day = day;
- /*
- * Decode the MFLRV indicators.
- * NEED TO FIGURE OUT how to deal with the request for service,
- * time quality, and frequency quality indicators some day.
- */
- if (syncchar != '0') {
- pp->leap = LEAP_NOTINSYNC;
- }
- else {
- switch (leapchar) {
- case '+':
- pp->leap = LEAP_ADDSECOND;
- break;
-
- case '0':
- pp->leap = LEAP_NOWARNING;
- break;
-
- case '-':
- pp->leap = LEAP_DELSECOND;
- break;
-
- default:
- #ifdef DEBUG
- if (debug)
- printf("hpgps: unrecognized leap indicator: %c\n",
- leapchar);
- #endif
- refclock_report(peer, CEVNT_BADTIME);
- return;
- } /* end of leapchar switch */
- }
- /*
- * 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)) {
- refclock_report(peer, CEVNT_BADTIME);
- return;
- }
- pp->lastref = pp->lastrec;
- refclock_receive(peer);
- /*
- * If CLK_FLAG4 is set, ask for the status screen response.
- */
- if (pp->sloppyclockflag & CLK_FLAG4){
- up->linecnt = 22;
- if (write(pp->io.fd, ":SYSTEM:PRINT?\r", 15) != 15)
- refclock_report(peer, CEVNT_FAULT);
- }
- }
- /*
- * hpgps_poll - called by the transmit procedure
- */
- static void
- hpgps_poll(
- int unit,
- struct peer *peer
- )
- {
- register struct hpgpsunit *up;
- struct refclockproc *pp;
- /*
- * Time to poll the clock. The HP 58503A responds to a
- * ":PTIME:TCODE?" by returning a timecode in the format specified
- * above. If nothing is heard from the clock for two polls,
- * declare a timeout and keep going.
- */
- pp = peer->procptr;
- up = (struct hpgpsunit *)pp->unitptr;
- if (up->pollcnt == 0)
- refclock_report(peer, CEVNT_TIMEOUT);
- else
- up->pollcnt--;
- if (write(pp->io.fd, ":PTIME:TCODE?\r", 14) != 14) {
- refclock_report(peer, CEVNT_FAULT);
- }
- else
- pp->polls++;
- }
- #else
- int refclock_hpgps_bs;
- #endif /* REFCLOCK */