NetBSD/dist/ntp/ntpd/refclock_heath.c

490 lines
13 KiB
C

/* $NetBSD: refclock_heath.c,v 1.1.1.1 2000/03/29 12:38:53 simonb Exp $ */
/*
* 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 */