#ifdef HAVE_SYS_IOCTL_H
# include <sys/ioctl.h>
#endif /* not HAVE_SYS_IOCTL_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.
*
* There were two GC-1000 versions supported by this driver. The original
* GC-1000 with RS-232 output first appeared in 1983, but dissapeared
* from the market a few years later. The GC-1001 II with RS-232 output
* first appeared circa 1990, but apparently is no longer manufactured.
* The two models differ considerably, both in interface and commands.
* The GC-1000 has a pseudo-bipolar timecode output triggered by a RTS
* transition. The timecode includes both the day of year and time of
* day. The GC-1001 II has a true bipolar output and a complement of
* single character commands. The timecode includes only the time of
* day.
*
* The GC-1001 II was apparently never tested and, based on a Coverity
* scan, apparently never worked [Bug 689]. Related code has been disabled.
*
* GC-1000
*
* The internal DIPswitches should be set to operate in MANUAL mode. The
* external DIPswitches should be set to GMT and 24-hour format.
*
* 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.
*
* GC-1001 II
*
* Commands consist of a single letter and are case sensitive. When
* enterred in lower case, a description of the action performed is
* displayed. When enterred in upper case the action is performed.
* Following is a summary of descriptions as displayed by the clock:
*
* The clock responds with a command The 'A' command returns an ASCII
* local time string: HH:MM:SS.T xx<CR>, where
*
* HH = hours
* MM = minutes
* SS = seconds
* T = tenths-of-seconds
* xx = 'AM', 'PM', or ' '
* <CR> = carriage return
*
* The 'D' command returns 24 pairs of bytes containing the variable
* divisor value at the end of each of the previous 24 hours. This
* allows the timebase trimming process to be observed. UTC hour 00 is
* always returned first. The first byte of each pair is the high byte
* of (variable divisor * 16); the second byte is the low byte of
* (variable divisor * 16). For example, the byte pair 3C 10 would be
* returned for a divisor of 03C1 hex (961 decimal).
*
* The 'I' command returns: | TH | TL | ER | DH | DL | U1 | I1 | I2 | ,
* where
*
* TH = minutes since timebase last trimmed (high byte)
* TL = minutes since timebase last trimmed (low byte)
* ER = last accumulated error in 1.25 ms increments
* DH = high byte of (current variable divisor * 16)
* DL = low byte of (current variable divisor * 16)
* U1 = UT1 offset (/.1 s): | + | 4 | 2 | 1 | 0 | 0 | 0 | 0 |
* I1 = information byte 1: | W | C | D | I | U | T | Z | 1 | ,
* where
*
* W = set by WWV(H)
* C = CAPTURE LED on
* D = TRIM DN LED on
* I = HI SPEC LED on
* U = TRIM UP LED on
* T = DST switch on
* Z = UTC switch on
* 1 = UT1 switch on
*
* I2 = information byte 2: | 8 | 8 | 4 | 2 | 1 | D | d | S | ,
* where
*
* 8, 8, 4, 2, 1 = TIME ZONE switch settings
* D = DST bit (#55) in last-received frame
* d = DST bit (#2) in last-received frame
* S = clock is in simulation mode
*
* The 'P' command returns 24 bytes containing the number of frames
* received without error during UTC hours 00 through 23, providing an
* indication of hourly propagation. These bytes are updated each hour
* to reflect the previous 24 hour period. UTC hour 00 is always
* returned first.
*
* The 'T' command returns the UTC time: | HH | MM | SS | T0 | , where
* HH = tens-of-hours and hours (packed BCD)
* MM = tens-of-minutes and minutes (packed BCD)
* SS = tens-of-seconds and seconds (packed BCD)
* T = tenths-of-seconds (BCD)
*
* 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 PRECISION (-4) /* precision assumed (about 100 ms) */
#define REFID "WWV\0" /* reference ID */
#define DESCRIPTION "Heath GC-1000 Most Accurate Clock" /* WRU */
/*
* 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};
/*
* Baud rate table. The GC-1000 supports 1200, 2400 and 4800; the
* GC-1001 II supports only 9600.
*/
static int speed[] = {B1200, B2400, B4800, B9600};
/*
* 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 */
};
/*
* heath_start - open the devices and initialize data for processing
*/
static int
heath_start(
int unit,
struct peer *peer
)
{
struct refclockproc *pp;
int fd;
char device[20];
/*
* Open serial port
*/
snprintf(device, sizeof(device), DEVICE, unit);
fd = refclock_open(&peer->srcadr, device, speed[peer->ttl & 0x3],
LDISC_REMOTE);
if (fd <= 0)
return (0);
pp = peer->procptr;
pp->io.clock_recv = heath_receive;
pp->io.srcclock = peer;
pp->io.datalen = 0;
pp->io.fd = fd;
if (!io_addclock(&pp->io)) {
close(fd);
pp->io.fd = -1;
return (0);
}
/*
* heath_shutdown - shut down the clock
*/
static void
heath_shutdown(
int unit,
struct peer *peer
)
{
struct refclockproc *pp;
pp = peer->procptr;
if (-1 != pp->io.fd)
io_closeclock(&pp->io);
}
/*
* heath_receive - receive data from the serial interface
*/
static void
heath_receive(
struct recvbuf *rbufp
)
{
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 = rbufp->recv_peer;
pp = peer->procptr;
pp->lencode = refclock_gtlin(rbufp, pp->a_lastcode, BMAX,
&trtmp);
/*
* 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.
*/
switch (pp->lencode) {
/*
* GC-1000 timecode format: "hh:mm:ss.f AM mm/dd/yy"
* GC-1001 II timecode format: "hh:mm:ss.f "
*/
case LENHEATH1:
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;
}
break;
time(&now); /* we should grab 'now' earlier */
tm_time_p = gmtime(&now);
/*
* There is a window of time around midnight
* where this will Do The Wrong Thing.
*/
if (tm_time_p) {
month = tm_time_p->tm_mon + 1;
day = tm_time_p->tm_mday;
} else {
refclock_report(peer, CEVNT_FAULT);
return;
}
}
break;
#endif
/*
* 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.
*/
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((unsigned char)dsec))
pp->leap = LEAP_NOTINSYNC;
else {
pp->nsec = (dsec - '0') * 100000000;
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
)
{
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.
* Apparently, the radio takes about a second to make up its
* mind to send a timecode, so the receive timestamp is
* worthless.
*/
pp = peer->procptr;
/*
* We toggle the RTS modem control lead (GC-1000) and sent a T
* (GC-1001 II) 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.
*
* Bug 689: Even though we no longer support the GC-1001 II,
* I'm leaving the 'T' write in for timing purposes.
*/
if (ioctl(pp->io.fd, TIOCMBIC, (char *)&bits) < 0)
refclock_report(peer, CEVNT_FAULT);
get_systime(&pp->lastrec);
if (refclock_write(peer, "T", 1, "T") != 1)
refclock_report(peer, CEVNT_FAULT);
ioctl(pp->io.fd, TIOCMBIS, (char *)&bits);
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);
#ifdef DEBUG
if (debug)
printf("heath: timecode %d %s\n", pp->lencode,
pp->a_lastcode);
#endif
pp->polls++;
}
