Annotation of embedaddon/ntp/ntpd/refclock_heath.c, revision 1.1.1.1
1.1 misho 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
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: if (!(fd = refclock_open(device, speed[peer->ttl & 0x3],
226: LDISC_REMOTE)))
227: return (0);
228: pp = peer->procptr;
229: pp->io.clock_recv = heath_receive;
230: pp->io.srcclock = (caddr_t)peer;
231: pp->io.datalen = 0;
232: pp->io.fd = fd;
233: if (!io_addclock(&pp->io)) {
234: close(fd);
235: pp->io.fd = -1;
236: return (0);
237: }
238:
239: /*
240: * Initialize miscellaneous variables
241: */
242: peer->precision = PRECISION;
243: peer->burst = NSTAGE;
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
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
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 = (struct peer *)rbufp->recv_srcclock;
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((int)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
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 (write(pp->io.fd, "T", 1) != 1)
431: refclock_report(peer, CEVNT_FAULT);
432: ioctl(pp->io.fd, TIOCMBIS, (char *)&bits);
433: if (peer->burst > 0)
434: return;
435: if (pp->coderecv == pp->codeproc) {
436: refclock_report(peer, CEVNT_TIMEOUT);
437: return;
438: }
439: pp->lastref = pp->lastrec;
440: refclock_receive(peer);
441: record_clock_stats(&peer->srcadr, pp->a_lastcode);
442: #ifdef DEBUG
443: if (debug)
444: printf("heath: timecode %d %s\n", pp->lencode,
445: pp->a_lastcode);
446: #endif
447: peer->burst = MAXSTAGE;
448: pp->polls++;
449: }
450:
451: #else
452: int refclock_heath_bs;
453: #endif /* REFCLOCK */
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