diff options
Diffstat (limited to 'contrib/ntp/ntpd/refclock_heath.c')
-rw-r--r-- | contrib/ntp/ntpd/refclock_heath.c | 487 |
1 files changed, 487 insertions, 0 deletions
diff --git a/contrib/ntp/ntpd/refclock_heath.c b/contrib/ntp/ntpd/refclock_heath.c new file mode 100644 index 0000000..9d297d1 --- /dev/null +++ b/contrib/ntp/ntpd/refclock_heath.c @@ -0,0 +1,487 @@ +/* + * refclock_heath - clock driver for Heath GC-1000 Most Accurate Clock + */ +#ifdef HAVE_CONFIG_H +#include <config.h> +#endif + +#if defined(REFCLOCK) && defined(CLOCK_HEATH) + +#include <stdio.h> +#include <ctype.h> +#ifdef TIME_WITH_SYS_TIME +# include <sys/time.h> +# include <time.h> +#else +# ifdef TM_IN_SYS_TIME +# include <sys/time.h> +# else +# include <time.h> +# endif +#endif +#ifdef HAVE_SYS_IOCTL_H +# include <sys/ioctl.h> +#endif /* not HAVE_SYS_IOCTL_H */ + +#include "ntpd.h" +#include "ntp_io.h" +#include "ntp_refclock.h" +#include "ntp_stdlib.h" + +/* + * This driver supports the Heath GC-1000 Most Accurate Clock, with + * RS232C Output Accessory. This is a WWV/WWVH receiver somewhat less + * robust than other supported receivers. Its claimed accuracy is 100 ms + * when actually synchronized to the broadcast signal, but this doesn't + * happen even most of the time, due to propagation conditions, ambient + * noise sources, etc. When not synchronized, the accuracy is at the + * whim of the internal clock oscillator, which can wander into the + * sunset without warning. Since the indicated precision is 100 ms, + * expect a host synchronized only to this thing to wander to and fro, + * occasionally being rudely stepped when the offset exceeds the default + * clock_max of 128 ms. + * + * The internal DIPswitches should be set to operate at 1200 baud in + * MANUAL mode and the current year. The external DIPswitches should be + * set to GMT and 24-hour format, or to the host local time zone (with + * DST) and 12-hour format. It is very important that the year be + * set correctly in the DIPswitches. Otherwise, the day of year will be + * incorrect after 28 April[?] of a normal or leap year. In 12-hour mode + * with DST selected the clock will be incorrect by an hour for an + * indeterminate amount of time between 0000Z and 0200 on the day DST + * changes. + * + * In MANUAL mode the clock responds to a rising edge of the request to + * send (RTS) modem control line by sending the timecode. Therefore, it + * is necessary that the operating system implement the TIOCMBIC and + * TIOCMBIS ioctl system calls and TIOCM_RTS control bit. Present + * restrictions require the use of a POSIX-compatible programming + * interface, although other interfaces may work as well. + * + * A simple hardware modification to the clock can be made which + * prevents the clock hearing the request to send (RTS) if the HI SPEC + * lamp is out. Route the HISPEC signal to the tone decoder board pin + * 19, from the display, pin 19. Isolate pin 19 of the decoder board + * first, but maintain connection with pin 10. Also isolate pin 38 of + * the CPU on the tone board, and use half an added 7400 to gate the + * original signal to pin 38 with that from pin 19. + * + * The clock message consists of 23 ASCII printing characters in the + * following format: + * + * hh:mm:ss.f AM dd/mm/yr<cr> + * + * hh:mm:ss.f = hours, minutes, seconds + * f = deciseconds ('?' when out of spec) + * AM/PM/bb = blank in 24-hour mode + * dd/mm/yr = day, month, year + * + * The alarm condition is indicated by '?', rather than a digit, at f. + * Note that 0?:??:??.? is displayed before synchronization is first + * established and hh:mm:ss.? once synchronization is established and + * then lost again for about a day. + * + * Fudge Factors + * + * A fudge time1 value of .04 s appears to center the clock offset + * residuals. The fudge time2 parameter is the local time offset east of + * Greenwich, which depends on DST. Sorry about that, but the clock + * gives no hint on what the DIPswitches say. + */ + +/* + * Interface definitions + */ +#define DEVICE "/dev/heath%d" /* device name and unit */ +#define SPEED232 B1200 /* uart speed (1200 baud) */ +#define PRECISION (-4) /* precision assumed (about 100 ms) */ +#define REFID "WWV\0" /* reference ID */ +#define DESCRIPTION "Heath GC-1000 Most Accurate Clock" /* WRU */ + +#define LENHEATH 23 /* min timecode length */ + +/* + * Tables to compute the ddd of year form icky dd/mm 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 heathunit { + int pollcnt; /* poll message counter */ + l_fp tstamp; /* timestamp of last poll */ +}; + +/* + * Function prototypes + */ +static int heath_start P((int, struct peer *)); +static void heath_shutdown P((int, struct peer *)); +static void heath_receive P((struct recvbuf *)); +static void heath_poll P((int, struct peer *)); + +/* + * Transfer vector + */ +struct refclock refclock_heath = { + heath_start, /* start up driver */ + heath_shutdown, /* shut down driver */ + heath_poll, /* transmit poll message */ + noentry, /* not used (old heath_control) */ + noentry, /* initialize driver */ + noentry, /* not used (old heath_buginfo) */ + NOFLAGS /* not used */ +}; + +#if 0 +/* + * Gee, Unix so thoughfully omitted code to convert from a struct tm to + * a long, so I'll just have to ferret out the inverse myself, the hard way. + * (Newton's method.) + */ +#define timelocal(x) invert(x, localtime) +/* + * comparetm compares two tm structures and returns -1 if the first + * is less than the second, 0 if they are equal, and +1 if the first + * is greater than the second. Only the year, month, day, hour, minute + * and second are compared. The yearday (Julian), day of week, and isdst + * are not compared. + */ + +static int +comparetm( + struct tm *a, + struct tm *b + ) +{ + if (a->tm_year < b->tm_year ) return -1; + if (a->tm_year > b->tm_year ) return 1; + if (a->tm_mon < b->tm_mon ) return -1; + if (a->tm_mon > b->tm_mon ) return 1; + if (a->tm_mday < b->tm_mday ) return -1; + if (a->tm_mday > b->tm_mday ) return 1; + if (a->tm_hour < b->tm_hour ) return -1; + if (a->tm_hour > b->tm_hour ) return 1; + if (a->tm_min < b->tm_min ) return -1; + if (a->tm_min > b->tm_min ) return 1; + if (a->tm_sec < b->tm_sec ) return -1; + if (a->tm_sec > b->tm_sec ) return 1; + return 0; +} + +static long +invert ( + struct tm *x, + struct tm *(*func)() + ) +{ + struct tm *y; + int result; + long trial; + long lower=0L; + long upper=(long)((unsigned long)(~lower) >> 1); + + do { + trial = (upper + lower) / 2L; + y = (*func)(&trial); + result = comparetm(x, y); + if (result < 0) upper = trial; + if (result > 0) lower = trial; + } while (result != 0); + return trial; +} +#endif /* 0 */ + + +/* + * heath_start - open the devices and initialize data for processing + */ +static int +heath_start( + int unit, + struct peer *peer + ) +{ + register struct heathunit *up; + struct refclockproc *pp; + int fd; + char device[20]; + + /* + * Open serial port + */ + (void)sprintf(device, DEVICE, unit); + if (!(fd = refclock_open(device, SPEED232, 0))) + return (0); + + /* + * Allocate and initialize unit structure + */ + if (!(up = (struct heathunit *) + emalloc(sizeof(struct heathunit)))) { + (void) close(fd); + return (0); + } + memset((char *)up, 0, sizeof(struct heathunit)); + pp = peer->procptr; + pp->io.clock_recv = heath_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; + peer->burst = NSTAGE; + pp->clockdesc = DESCRIPTION; + memcpy((char *)&pp->refid, REFID, 4); + up->pollcnt = 2; + return (1); +} + + +/* + * heath_shutdown - shut down the clock + */ +static void +heath_shutdown( + int unit, + struct peer *peer + ) +{ + register struct heathunit *up; + struct refclockproc *pp; + + pp = peer->procptr; + up = (struct heathunit *)pp->unitptr; + io_closeclock(&pp->io); + free(up); +} + + +/* + * heath_receive - receive data from the serial interface + */ +static void +heath_receive( + struct recvbuf *rbufp + ) +{ + register struct heathunit *up; + struct refclockproc *pp; + struct peer *peer; + l_fp trtmp; + int month, day; + int i; + char dsec, a[5]; + + /* + * Initialize pointers and read the timecode and timestamp + */ + peer = (struct peer *)rbufp->recv_srcclock; + pp = peer->procptr; + up = (struct heathunit *)pp->unitptr; + pp->lencode = refclock_gtlin(rbufp, pp->a_lastcode, BMAX, &trtmp); + + /* + * We get a buffer and timestamp for each <cr>; however, we use + * the timestamp captured at the RTS modem control line toggle + * on the assumption that's what the radio bases the timecode + * on. Apparently, the radio takes about a second to make up its + * mind to send a timecode, so the receive timestamp is + * worthless. + */ + pp->lastrec = up->tstamp; + up->pollcnt = 2; +#ifdef DEBUG + if (debug) + printf("heath: 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 < LENHEATH) { + refclock_report(peer, CEVNT_BADREPLY); + return; + } + + /* + * Timecode format: "hh:mm:ss.f AM mm/dd/yy" + */ + if (sscanf(pp->a_lastcode, "%2d:%2d:%2d.%c%5c%2d/%2d/%2d", + &pp->hour, &pp->minute, &pp->second, &dsec, a, &month, &day, + &pp->year) != 8) { + refclock_report(peer, CEVNT_BADREPLY); + return; + } + + /* + * If AM or PM is received, assume the clock is displaying local + * time. First, convert to 24-hour format. + */ + + switch (a[1]) { + case 'P': + if (12 > pp->hour) + pp->hour += 12; + break; + + case 'A': + if (12 == pp->hour) + pp->hour -= 12; + break; + } + + /* + * Now make a struct tm out of it, convert to UTC, and + * repopulate pp-> + */ + + if (' ' != a[1]) { + struct tm t, *q; + time_t l; + + t.tm_sec = pp->second; + t.tm_min = pp->minute; + t.tm_hour = pp->hour; + t.tm_mday = day; /* not converted to yday yet */ + t.tm_mon = month-1; /* ditto */ + t.tm_year = pp->year; + if ( t.tm_year < YEAR_PIVOT ) t.tm_year += 100; /* Y2KFixes */ + + t.tm_wday = -1; /* who knows? */ + t.tm_yday = -1; /* who knows? */ + t.tm_isdst = -1; /* who knows? */ + + l = mktime(&t); + if (l == -1) { + /* HMS: do we want to do this? */ + refclock_report(peer, CEVNT_BADTIME); + return; + } + q = gmtime(&l); + + pp->year = q->tm_year; + month = q->tm_mon+1; + day = q->tm_mday; /* still not converted */ + pp->hour = q->tm_hour; + /* pp->minute = q->tm_min; GC-1000 cannot adjust timezone */ + /* pp->second = q->tm_sec; by other than hour increments */ + } + + + + /* + * We determine the day of the year from the DIPswitches. This + * should be fixed, since somebody might forget to set them. + * Someday this hazard will be fixed by a fiendish scheme that + * looks at the timecode and year the radio shows, then computes + * the residue of the seconds mod the seconds in a leap cycle. + * If in the third year of that cycle and the third and later + * months of that year, add one to the day. Then, correct the + * timecode accordingly. Icky pooh. This bit of nonsense could + * be avoided if the engineers had been required to write a + * device driver before finalizing the timecode format. + * + * Yes, I know this code incorrectly thinks that 2000 is a leap + * year; but, the latest year that can be set by the DIPswitches + * is 1997 anyay. Life is short. + * Hey! Year 2000 IS a leap year! Y2KFixes + */ + if (month < 1 || month > 12 || day < 1) { + refclock_report(peer, CEVNT_BADTIME); + return; + } + if (pp->year % 4) { + if (day > day1tab[month - 1]) { + refclock_report(peer, CEVNT_BADTIME); + return; + } + for (i = 0; i < month - 1; i++) + day += day1tab[i]; + } else { + if (day > day2tab[month - 1]) { + refclock_report(peer, CEVNT_BADTIME); + return; + } + for (i = 0; i < month - 1; i++) + day += day2tab[i]; + } + pp->day = day; + + /* + * Determine synchronization and last update + */ + if (!isdigit((int)dsec)) + pp->leap = LEAP_NOTINSYNC; + else { + pp->msec = (dsec - '0') * 100; + pp->leap = LEAP_NOWARNING; + } + if (!refclock_process(pp)) + refclock_report(peer, CEVNT_BADTIME); +} + + +/* + * heath_poll - called by the transmit procedure + */ +static void +heath_poll( + int unit, + struct peer *peer + ) +{ + register struct heathunit *up; + struct refclockproc *pp; + int bits = TIOCM_RTS; + + /* + * At each poll we check for timeout and toggle the RTS modem + * control line, then take a timestamp. Presumably, this is the + * event the radio captures to generate the timecode. + */ + pp = peer->procptr; + up = (struct heathunit *)pp->unitptr; + pp->polls++; + + /* + * We toggle the RTS modem control lead to kick a timecode loose + * from the radio. This code works only for POSIX and SYSV + * interfaces. With bsd you are on your own. We take a timestamp + * between the up and down edges to lengthen the pulse, which + * should be about 50 usec on a Sun IPC. With hotshot CPUs, the + * pulse might get too short. Later. + */ + if (ioctl(pp->io.fd, TIOCMBIC, (char *)&bits) < 0) + refclock_report(peer, CEVNT_FAULT); + get_systime(&up->tstamp); + ioctl(pp->io.fd, TIOCMBIS, (char *)&bits); + if (peer->burst > 0) + return; + if (pp->coderecv == pp->codeproc) { + refclock_report(peer, CEVNT_TIMEOUT); + return; + } + record_clock_stats(&peer->srcadr, pp->a_lastcode); + refclock_receive(peer); + peer->burst = NSTAGE; +} + +#else +int refclock_heath_bs; +#endif /* REFCLOCK */ |