/* * 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; 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; record_clock_stats(&peer->srcadr, pp->a_lastcode); #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; 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. */ 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); return; } refclock_receive(peer); } /* * 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; if (up->pollcnt == 0) refclock_report(peer, CEVNT_TIMEOUT); else up->pollcnt--; 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); } #else int refclock_heath_bs; #endif /* REFCLOCK */