refclock_pcf.c revision 290001 
1/*
2 * refclock_pcf - clock driver for the Conrad parallel port radio clock
3 */
4
5#ifdef HAVE_CONFIG_H
6# include <config.h>
7#endif
8
9#if defined(REFCLOCK) && defined(CLOCK_PCF)
10
11#include "ntpd.h"
12#include "ntp_io.h"
13#include "ntp_refclock.h"
14#include "ntp_calendar.h"
15#include "ntp_stdlib.h"
16
17/*
18 * This driver supports the parallel port radio clock sold by Conrad
19 * Electronic under order numbers 967602 and 642002.
20 *
21 * It requires that the local timezone be CET/CEST and that the pcfclock
22 * device driver be installed.  A device driver for Linux is available at
23 * http://home.pages.de/~voegele/pcf.html.  Information about a FreeBSD
24 * driver is available at http://schumann.cx/pcfclock/.
25 */
26
27/*
28 * Interface definitions
29 */
30#define	DEVICE		"/dev/pcfclocks/%d"
31#define	OLDDEVICE	"/dev/pcfclock%d"
32#define	PRECISION	(-1)	/* precision assumed (about 0.5 s) */
33#define REFID		"PCF"
34#define DESCRIPTION	"Conrad parallel port radio clock"
35
36#define LENPCF		18	/* timecode length */
37
38/*
39 * Function prototypes
40 */
41static	int 	pcf_start 		(int, struct peer *);
42static	void	pcf_shutdown		(int, struct peer *);
43static	void	pcf_poll		(int, struct peer *);
44
45/*
46 * Transfer vector
47 */
48struct  refclock refclock_pcf = {
49	pcf_start,              /* start up driver */
50	pcf_shutdown,           /* shut down driver */
51	pcf_poll,               /* transmit poll message */
52	noentry,                /* not used */
53	noentry,                /* initialize driver (not used) */
54	noentry,                /* not used */
55	NOFLAGS                 /* not used */
56};
57
58
59/*
60 * pcf_start - open the device and initialize data for processing
61 */
62static int
63pcf_start(
64     	int unit,
65	struct peer *peer
66	)
67{
68	struct refclockproc *pp;
69	int fd;
70	char device[128];
71
72	/*
73	 * Open device file for reading.
74	 */
75	snprintf(device, sizeof(device), DEVICE, unit);
76	fd = open(device, O_RDONLY);
77	if (fd == -1) {
78		snprintf(device, sizeof(device), OLDDEVICE, unit);
79		fd = open(device, O_RDONLY);
80	}
81#ifdef DEBUG
82	if (debug)
83		printf ("starting PCF with device %s\n",device);
84#endif
85	if (fd == -1) {
86		return (0);
87	}
88
89	pp = peer->procptr;
90	pp->io.clock_recv = noentry;
91	pp->io.srcclock = peer;
92	pp->io.datalen = 0;
93	pp->io.fd = fd;
94
95	/*
96	 * Initialize miscellaneous variables
97	 */
98	peer->precision = PRECISION;
99	pp->clockdesc = DESCRIPTION;
100	/* one transmission takes 172.5 milliseconds since the radio clock
101	   transmits 69 bits with a period of 2.5 milliseconds per bit */
102	pp->fudgetime1 = 0.1725;
103	memcpy((char *)&pp->refid, REFID, 4);
104
105	return (1);
106}
107
108
109/*
110 * pcf_shutdown - shut down the clock
111 */
112static void
113pcf_shutdown(
114	int unit,
115	struct peer *peer
116	)
117{
118	struct refclockproc *pp;
119
120	pp = peer->procptr;
121	if (NULL != pp)
122		close(pp->io.fd);
123}
124
125
126/*
127 * pcf_poll - called by the transmit procedure
128 */
129static void
130pcf_poll(
131	int unit,
132	struct peer *peer
133	)
134{
135	struct refclockproc *pp;
136	char buf[LENPCF];
137	struct tm tm, *tp;
138	time_t t;
139
140	pp = peer->procptr;
141
142	buf[0] = 0;
143	if (read(pp->io.fd, buf, sizeof(buf)) < (ssize_t)sizeof(buf) || buf[0] != 9) {
144		refclock_report(peer, CEVNT_FAULT);
145		return;
146	}
147
148	ZERO(tm);
149
150	tm.tm_mday = buf[11] * 10 + buf[10];
151	tm.tm_mon = buf[13] * 10 + buf[12] - 1;
152	tm.tm_year = buf[15] * 10 + buf[14];
153	tm.tm_hour = buf[7] * 10 + buf[6];
154	tm.tm_min = buf[5] * 10 + buf[4];
155	tm.tm_sec = buf[3] * 10 + buf[2];
156	tm.tm_isdst = (buf[8] & 1) ? 1 : (buf[8] & 2) ? 0 : -1;
157
158	/*
159	 * Y2K convert the 2-digit year
160	 */
161	if (tm.tm_year < 99)
162		tm.tm_year += 100;
163
164	t = mktime(&tm);
165	if (t == (time_t) -1) {
166		refclock_report(peer, CEVNT_BADTIME);
167		return;
168	}
169
170#if defined(__GLIBC__) && defined(_BSD_SOURCE)
171	if ((tm.tm_isdst > 0 && tm.tm_gmtoff != 7200)
172	    || (tm.tm_isdst == 0 && tm.tm_gmtoff != 3600)
173	    || tm.tm_isdst < 0) {
174#ifdef DEBUG
175		if (debug)
176			printf ("local time zone not set to CET/CEST\n");
177#endif
178		refclock_report(peer, CEVNT_BADTIME);
179		return;
180	}
181#endif
182
183	pp->lencode = strftime(pp->a_lastcode, BMAX, "%Y %m %d %H %M %S", &tm);
184
185#if defined(_REENTRANT) || defined(_THREAD_SAFE)
186	tp = gmtime_r(&t, &tm);
187#else
188	tp = gmtime(&t);
189#endif
190	if (!tp) {
191		refclock_report(peer, CEVNT_FAULT);
192		return;
193	}
194
195	get_systime(&pp->lastrec);
196	pp->polls++;
197	pp->year = tp->tm_year + 1900;
198	pp->day = tp->tm_yday + 1;
199	pp->hour = tp->tm_hour;
200	pp->minute = tp->tm_min;
201	pp->second = tp->tm_sec;
202	pp->nsec = buf[16] * 31250000;
203	if (buf[17] & 1)
204		pp->nsec += 500000000;
205
206#ifdef DEBUG
207	if (debug)
208		printf ("pcf%d: time is %04d/%02d/%02d %02d:%02d:%02d UTC\n",
209			unit, pp->year, tp->tm_mon + 1, tp->tm_mday, pp->hour,
210			pp->minute, pp->second);
211#endif
212
213	if (!refclock_process(pp)) {
214		refclock_report(peer, CEVNT_BADTIME);
215		return;
216	}
217	record_clock_stats(&peer->srcadr, pp->a_lastcode);
218	if ((buf[1] & 1) && !(pp->sloppyclockflag & CLK_FLAG2))
219		pp->leap = LEAP_NOTINSYNC;
220	else
221		pp->leap = LEAP_NOWARNING;
222	pp->lastref = pp->lastrec;
223	refclock_receive(peer);
224}
225#else
226int refclock_pcf_bs;
227#endif /* REFCLOCK */
228