1 /*
2 * refclock_heath - clock driver for Heath GC-1000
3 * (but no longer the GC-1001 Model II, which apparently never worked)
4 */
5
6 #ifdef HAVE_CONFIG_H
7 # include <config.h>
8 #endif
9
10 #if defined(REFCLOCK) && defined(CLOCK_HEATH)
11
12 #include "ntpd.h"
13 #include "ntp_io.h"
14 #include "ntp_refclock.h"
15 #include "ntp_stdlib.h"
16
17 #include <stdio.h>
18 #include <ctype.h>
19
20 #ifdef HAVE_SYS_IOCTL_H
21 # include <sys/ioctl.h>
22 #endif /* not HAVE_SYS_IOCTL_H */
23
24 /*
25 * This driver supports the Heath GC-1000 Most Accurate Clock, with
26 * RS232C Output Accessory. This is a WWV/WWVH receiver somewhat less
27 * robust than other supported receivers. Its claimed accuracy is 100 ms
28 * when actually synchronized to the broadcast signal, but this doesn't
29 * happen even most of the time, due to propagation conditions, ambient
30 * noise sources, etc. When not synchronized, the accuracy is at the
31 * whim of the internal clock oscillator, which can wander into the
32 * sunset without warning. Since the indicated precision is 100 ms,
33 * expect a host synchronized only to this thing to wander to and fro,
34 * occasionally being rudely stepped when the offset exceeds the default
35 * clock_max of 128 ms.
36 *
37 * There were two GC-1000 versions supported by this driver. The original
38 * GC-1000 with RS-232 output first appeared in 1983, but dissapeared
39 * from the market a few years later. The GC-1001 II with RS-232 output
40 * first appeared circa 1990, but apparently is no longer manufactured.
41 * The two models differ considerably, both in interface and commands.
42 * The GC-1000 has a pseudo-bipolar timecode output triggered by a RTS
43 * transition. The timecode includes both the day of year and time of
44 * day. The GC-1001 II has a true bipolar output and a complement of
45 * single character commands. The timecode includes only the time of
46 * day.
47 *
48 * The GC-1001 II was apparently never tested and, based on a Coverity
49 * scan, apparently never worked [Bug 689]. Related code has been disabled.
50 *
51 * GC-1000
52 *
53 * The internal DIPswitches should be set to operate in MANUAL mode. The
54 * external DIPswitches should be set to GMT and 24-hour format.
55 *
56 * In MANUAL mode the clock responds to a rising edge of the request to
57 * send (RTS) modem control line by sending the timecode. Therefore, it
58 * is necessary that the operating system implement the TIOCMBIC and
59 * TIOCMBIS ioctl system calls and TIOCM_RTS control bit. Present
60 * restrictions require the use of a POSIX-compatible programming
61 * interface, although other interfaces may work as well.
62 *
63 * A simple hardware modification to the clock can be made which
64 * prevents the clock hearing the request to send (RTS) if the HI SPEC
65 * lamp is out. Route the HISPEC signal to the tone decoder board pin
66 * 19, from the display, pin 19. Isolate pin 19 of the decoder board
67 * first, but maintain connection with pin 10. Also isolate pin 38 of
68 * the CPU on the tone board, and use half an added 7400 to gate the
69 * original signal to pin 38 with that from pin 19.
70 *
71 * The clock message consists of 23 ASCII printing characters in the
72 * following format:
73 *
74 * hh:mm:ss.f AM dd/mm/yr<cr>
75 *
76 * hh:mm:ss.f = hours, minutes, seconds
77 * f = deciseconds ('?' when out of spec)
78 * AM/PM/bb = blank in 24-hour mode
79 * dd/mm/yr = day, month, year
80 *
81 * The alarm condition is indicated by '?', rather than a digit, at f.
82 * Note that 0?:??:??.? is displayed before synchronization is first
83 * established and hh:mm:ss.? once synchronization is established and
84 * then lost again for about a day.
85 *
86 * GC-1001 II
87 *
88 * Commands consist of a single letter and are case sensitive. When
89 * enterred in lower case, a description of the action performed is
90 * displayed. When enterred in upper case the action is performed.
91 * Following is a summary of descriptions as displayed by the clock:
92 *
93 * The clock responds with a command The 'A' command returns an ASCII
94 * local time string: HH:MM:SS.T xx<CR>, where
95 *
96 * HH = hours
97 * MM = minutes
98 * SS = seconds
99 * T = tenths-of-seconds
100 * xx = 'AM', 'PM', or ' '
101 * <CR> = carriage return
102 *
103 * The 'D' command returns 24 pairs of bytes containing the variable
104 * divisor value at the end of each of the previous 24 hours. This
105 * allows the timebase trimming process to be observed. UTC hour 00 is
106 * always returned first. The first byte of each pair is the high byte
107 * of (variable divisor * 16); the second byte is the low byte of
108 * (variable divisor * 16). For example, the byte pair 3C 10 would be
109 * returned for a divisor of 03C1 hex (961 decimal).
110 *
111 * The 'I' command returns: | TH | TL | ER | DH | DL | U1 | I1 | I2 | ,
112 * where
113 *
114 * TH = minutes since timebase last trimmed (high byte)
115 * TL = minutes since timebase last trimmed (low byte)
116 * ER = last accumulated error in 1.25 ms increments
117 * DH = high byte of (current variable divisor * 16)
118 * DL = low byte of (current variable divisor * 16)
119 * U1 = UT1 offset (/.1 s): | + | 4 | 2 | 1 | 0 | 0 | 0 | 0 |
120 * I1 = information byte 1: | W | C | D | I | U | T | Z | 1 | ,
121 * where
122 *
123 * W = set by WWV(H)
124 * C = CAPTURE LED on
125 * D = TRIM DN LED on
126 * I = HI SPEC LED on
127 * U = TRIM UP LED on
128 * T = DST switch on
129 * Z = UTC switch on
130 * 1 = UT1 switch on
131 *
132 * I2 = information byte 2: | 8 | 8 | 4 | 2 | 1 | D | d | S | ,
133 * where
134 *
135 * 8, 8, 4, 2, 1 = TIME ZONE switch settings
136 * D = DST bit (#55) in last-received frame
137 * d = DST bit (#2) in last-received frame
138 * S = clock is in simulation mode
139 *
140 * The 'P' command returns 24 bytes containing the number of frames
141 * received without error during UTC hours 00 through 23, providing an
142 * indication of hourly propagation. These bytes are updated each hour
143 * to reflect the previous 24 hour period. UTC hour 00 is always
144 * returned first.
145 *
146 * The 'T' command returns the UTC time: | HH | MM | SS | T0 | , where
147 * HH = tens-of-hours and hours (packed BCD)
148 * MM = tens-of-minutes and minutes (packed BCD)
149 * SS = tens-of-seconds and seconds (packed BCD)
150 * T = tenths-of-seconds (BCD)
151 *
152 * Fudge Factors
153 *
154 * A fudge time1 value of .04 s appears to center the clock offset
155 * residuals. The fudge time2 parameter is the local time offset east of
156 * Greenwich, which depends on DST. Sorry about that, but the clock
157 * gives no hint on what the DIPswitches say.
158 */
159
160 /*
161 * Interface definitions
162 */
163 #define DEVICE "/dev/heath%d" /* device name and unit */
164 #define PRECISION (-4) /* precision assumed (about 100 ms) */
165 #define REFID "WWV\0" /* reference ID */
166 #define DESCRIPTION "Heath GC-1000 Most Accurate Clock" /* WRU */
167
168 #define LENHEATH1 23 /* min timecode length */
169 #if 0 /* BUG 689 */
170 #define LENHEATH2 13 /* min timecode length */
171 #endif
172
173 /*
174 * Tables to compute the ddd of year form icky dd/mm timecode. Viva la
175 * leap.
176 */
177 static int day1tab[] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
178 static int day2tab[] = {31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
179
180 /*
181 * Baud rate table. The GC-1000 supports 1200, 2400 and 4800; the
182 * GC-1001 II supports only 9600.
183 */
184 static int speed[] = {B1200, B2400, B4800, B9600};
185
186 /*
187 * Function prototypes
188 */
189 static int heath_start (int, struct peer *);
190 static void heath_shutdown (int, struct peer *);
191 static void heath_receive (struct recvbuf *);
192 static void heath_poll (int, struct peer *);
193
194 /*
195 * Transfer vector
196 */
197 struct refclock refclock_heath = {
198 heath_start, /* start up driver */
199 heath_shutdown, /* shut down driver */
200 heath_poll, /* transmit poll message */
201 noentry, /* not used (old heath_control) */
202 noentry, /* initialize driver */
203 noentry, /* not used (old heath_buginfo) */
204 NOFLAGS /* not used */
205 };
206
207
208 /*
209 * heath_start - open the devices and initialize data for processing
210 */
211 static int
heath_start(int unit,struct peer * peer)212 heath_start(
213 int unit,
214 struct peer *peer
215 )
216 {
217 struct refclockproc *pp;
218 int fd;
219 char device[20];
220
221 /*
222 * Open serial port
223 */
224 snprintf(device, sizeof(device), DEVICE, unit);
225 fd = refclock_open(&peer->srcadr, device, speed[peer->ttl & 0x3],
226 LDISC_REMOTE);
227 if (fd <= 0)
228 return (0);
229 pp = peer->procptr;
230 pp->io.clock_recv = heath_receive;
231 pp->io.srcclock = peer;
232 pp->io.datalen = 0;
233 pp->io.fd = fd;
234 if (!io_addclock(&pp->io)) {
235 close(fd);
236 pp->io.fd = -1;
237 return (0);
238 }
239
240 /*
241 * Initialize miscellaneous variables
242 */
243 peer->precision = PRECISION;
244 pp->clockdesc = DESCRIPTION;
245 memcpy(&pp->refid, REFID, 4);
246 return (1);
247 }
248
249
250 /*
251 * heath_shutdown - shut down the clock
252 */
253 static void
heath_shutdown(int unit,struct peer * peer)254 heath_shutdown(
255 int unit,
256 struct peer *peer
257 )
258 {
259 struct refclockproc *pp;
260
261 pp = peer->procptr;
262 if (-1 != pp->io.fd)
263 io_closeclock(&pp->io);
264 }
265
266
267 /*
268 * heath_receive - receive data from the serial interface
269 */
270 static void
heath_receive(struct recvbuf * rbufp)271 heath_receive(
272 struct recvbuf *rbufp
273 )
274 {
275 struct refclockproc *pp;
276 struct peer *peer;
277 l_fp trtmp;
278 int month, day;
279 int i;
280 char dsec, a[5];
281
282 /*
283 * Initialize pointers and read the timecode and timestamp
284 */
285 peer = rbufp->recv_peer;
286 pp = peer->procptr;
287 pp->lencode = refclock_gtlin(rbufp, pp->a_lastcode, BMAX,
288 &trtmp);
289
290 /*
291 * We get down to business, check the timecode format and decode
292 * its contents. If the timecode has invalid length or is not in
293 * proper format, we declare bad format and exit.
294 */
295 switch (pp->lencode) {
296
297 /*
298 * GC-1000 timecode format: "hh:mm:ss.f AM mm/dd/yy"
299 * GC-1001 II timecode format: "hh:mm:ss.f "
300 */
301 case LENHEATH1:
302 if (sscanf(pp->a_lastcode,
303 "%2d:%2d:%2d.%c%5c%2d/%2d/%2d", &pp->hour,
304 &pp->minute, &pp->second, &dsec, a, &month, &day,
305 &pp->year) != 8) {
306 refclock_report(peer, CEVNT_BADREPLY);
307 return;
308 }
309 break;
310
311 #if 0 /* BUG 689 */
312 /*
313 * GC-1001 II timecode format: "hh:mm:ss.f "
314 */
315 case LENHEATH2:
316 if (sscanf(pp->a_lastcode, "%2d:%2d:%2d.%c", &pp->hour,
317 &pp->minute, &pp->second, &dsec) != 4) {
318 refclock_report(peer, CEVNT_BADREPLY);
319 return;
320 } else {
321 struct tm *tm_time_p;
322 time_t now;
323
324 time(&now); /* we should grab 'now' earlier */
325 tm_time_p = gmtime(&now);
326 /*
327 * There is a window of time around midnight
328 * where this will Do The Wrong Thing.
329 */
330 if (tm_time_p) {
331 month = tm_time_p->tm_mon + 1;
332 day = tm_time_p->tm_mday;
333 } else {
334 refclock_report(peer, CEVNT_FAULT);
335 return;
336 }
337 }
338 break;
339 #endif
340
341 default:
342 refclock_report(peer, CEVNT_BADREPLY);
343 return;
344 }
345
346 /*
347 * We determine the day of the year from the DIPswitches. This
348 * should be fixed, since somebody might forget to set them.
349 * Someday this hazard will be fixed by a fiendish scheme that
350 * looks at the timecode and year the radio shows, then computes
351 * the residue of the seconds mod the seconds in a leap cycle.
352 * If in the third year of that cycle and the third and later
353 * months of that year, add one to the day. Then, correct the
354 * timecode accordingly. Icky pooh. This bit of nonsense could
355 * be avoided if the engineers had been required to write a
356 * device driver before finalizing the timecode format.
357 */
358 if (month < 1 || month > 12 || day < 1) {
359 refclock_report(peer, CEVNT_BADTIME);
360 return;
361 }
362 if (pp->year % 4) {
363 if (day > day1tab[month - 1]) {
364 refclock_report(peer, CEVNT_BADTIME);
365 return;
366 }
367 for (i = 0; i < month - 1; i++)
368 day += day1tab[i];
369 } else {
370 if (day > day2tab[month - 1]) {
371 refclock_report(peer, CEVNT_BADTIME);
372 return;
373 }
374 for (i = 0; i < month - 1; i++)
375 day += day2tab[i];
376 }
377 pp->day = day;
378
379 /*
380 * Determine synchronization and last update
381 */
382 if (!isdigit((unsigned char)dsec))
383 pp->leap = LEAP_NOTINSYNC;
384 else {
385 pp->nsec = (dsec - '0') * 100000000;
386 pp->leap = LEAP_NOWARNING;
387 }
388 if (!refclock_process(pp))
389 refclock_report(peer, CEVNT_BADTIME);
390 }
391
392
393 /*
394 * heath_poll - called by the transmit procedure
395 */
396 static void
heath_poll(int unit,struct peer * peer)397 heath_poll(
398 int unit,
399 struct peer *peer
400 )
401 {
402 struct refclockproc *pp;
403 int bits = TIOCM_RTS;
404
405 /*
406 * At each poll we check for timeout and toggle the RTS modem
407 * control line, then take a timestamp. Presumably, this is the
408 * event the radio captures to generate the timecode.
409 * Apparently, the radio takes about a second to make up its
410 * mind to send a timecode, so the receive timestamp is
411 * worthless.
412 */
413 pp = peer->procptr;
414
415 /*
416 * We toggle the RTS modem control lead (GC-1000) and sent a T
417 * (GC-1001 II) to kick a timecode loose from the radio. This
418 * code works only for POSIX and SYSV interfaces. With bsd you
419 * are on your own. We take a timestamp between the up and down
420 * edges to lengthen the pulse, which should be about 50 usec on
421 * a Sun IPC. With hotshot CPUs, the pulse might get too short.
422 * Later.
423 *
424 * Bug 689: Even though we no longer support the GC-1001 II,
425 * I'm leaving the 'T' write in for timing purposes.
426 */
427 if (ioctl(pp->io.fd, TIOCMBIC, (char *)&bits) < 0)
428 refclock_report(peer, CEVNT_FAULT);
429 get_systime(&pp->lastrec);
430 if (refclock_write(peer, "T", 1, "T") != 1)
431 refclock_report(peer, CEVNT_FAULT);
432 ioctl(pp->io.fd, TIOCMBIS, (char *)&bits);
433 if (pp->coderecv == pp->codeproc) {
434 refclock_report(peer, CEVNT_TIMEOUT);
435 return;
436 }
437 pp->lastref = pp->lastrec;
438 refclock_receive(peer);
439 record_clock_stats(&peer->srcadr, pp->a_lastcode);
440 #ifdef DEBUG
441 if (debug)
442 printf("heath: timecode %d %s\n", pp->lencode,
443 pp->a_lastcode);
444 #endif
445 pp->polls++;
446 }
447
448 #else
449 int refclock_heath_bs;
450 #endif /* REFCLOCK */
451