summaryrefslogtreecommitdiff
path: root/ntpd/refclock_pcf.c
blob: 45b3475c0d68f87d152c5a62360571ed82499188 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
/*
 * refclock_pcf - clock driver for the Conrad parallel port radio clock
 */

#ifdef HAVE_CONFIG_H
# include <config.h>
#endif

#if defined(REFCLOCK) && defined(CLOCK_PCF)

#include "ntpd.h"
#include "ntp_io.h"
#include "ntp_refclock.h"
#include "ntp_calendar.h"
#include "ntp_stdlib.h"

/*
 * This driver supports the parallel port radio clock sold by Conrad
 * Electronic under order numbers 967602 and 642002.
 *
 * It requires that the local timezone be CET/CEST and that the pcfclock
 * device driver be installed.  A device driver for Linux is available at
 * http://home.pages.de/~voegele/pcf.html.  Information about a FreeBSD
 * driver is available at http://schumann.cx/pcfclock/.
 */

/*
 * Interface definitions
 */
#define	DEVICE		"/dev/pcfclocks/%d"
#define	OLDDEVICE	"/dev/pcfclock%d"
#define	PRECISION	(-1)	/* precision assumed (about 0.5 s) */
#define REFID		"PCF"
#define DESCRIPTION	"Conrad parallel port radio clock"

#define LENPCF		18	/* timecode length */

/*
 * Function prototypes
 */
static	int 	pcf_start 		(int, struct peer *);
static	void	pcf_shutdown		(int, struct peer *);
static	void	pcf_poll		(int, struct peer *);

/*
 * Transfer vector
 */
struct  refclock refclock_pcf = {
	pcf_start,              /* start up driver */
	pcf_shutdown,           /* shut down driver */
	pcf_poll,               /* transmit poll message */
	noentry,                /* not used */
	noentry,                /* initialize driver (not used) */
	noentry,                /* not used */
	NOFLAGS                 /* not used */
};


/*
 * pcf_start - open the device and initialize data for processing
 */
static int
pcf_start(
     	int unit,
	struct peer *peer
	)
{
	struct refclockproc *pp;
	int fd;
	char device[128];

	/*
	 * Open device file for reading.
	 */
	snprintf(device, sizeof(device), DEVICE, unit);
	fd = open(device, O_RDONLY);
	if (fd == -1) {
		snprintf(device, sizeof(device), OLDDEVICE, unit);
		fd = open(device, O_RDONLY);
	}
#ifdef DEBUG
	if (debug)
		printf ("starting PCF with device %s\n",device);
#endif
	if (fd == -1) {
		return (0);
	}
	
	pp = peer->procptr;
	pp->io.clock_recv = noentry;
	pp->io.srcclock = peer;
	pp->io.datalen = 0;
	pp->io.fd = fd;
	
	/*
	 * Initialize miscellaneous variables
	 */
	peer->precision = PRECISION;
	pp->clockdesc = DESCRIPTION;
	/* one transmission takes 172.5 milliseconds since the radio clock
	   transmits 69 bits with a period of 2.5 milliseconds per bit */
	pp->fudgetime1 = 0.1725;
	memcpy((char *)&pp->refid, REFID, 4);

	return (1);
}


/*
 * pcf_shutdown - shut down the clock
 */
static void
pcf_shutdown(
	int unit,
	struct peer *peer
	)
{
	struct refclockproc *pp;
	
	pp = peer->procptr;
	if (NULL != pp)
		close(pp->io.fd);
}


/*
 * pcf_poll - called by the transmit procedure
 */
static void
pcf_poll(
	int unit,
	struct peer *peer
	)
{
	struct refclockproc *pp;
	char buf[LENPCF];
	struct tm tm, *tp;
	time_t t;
	
	pp = peer->procptr;

	buf[0] = 0;
	if (read(pp->io.fd, buf, sizeof(buf)) < (ssize_t)sizeof(buf) || buf[0] != 9) {
		refclock_report(peer, CEVNT_FAULT);
		return;
	}

	ZERO(tm);

	tm.tm_mday = buf[11] * 10 + buf[10];
	tm.tm_mon = buf[13] * 10 + buf[12] - 1;
	tm.tm_year = buf[15] * 10 + buf[14];
	tm.tm_hour = buf[7] * 10 + buf[6];
	tm.tm_min = buf[5] * 10 + buf[4];
	tm.tm_sec = buf[3] * 10 + buf[2];
	tm.tm_isdst = (buf[8] & 1) ? 1 : (buf[8] & 2) ? 0 : -1;

	/*
	 * Y2K convert the 2-digit year
	 */
	if (tm.tm_year < 99)
		tm.tm_year += 100;
	
	t = mktime(&tm);
	if (t == (time_t) -1) {
		refclock_report(peer, CEVNT_BADTIME);
		return;
	}

#if defined(__GLIBC__) && defined(_BSD_SOURCE)
	if ((tm.tm_isdst > 0 && tm.tm_gmtoff != 7200)
	    || (tm.tm_isdst == 0 && tm.tm_gmtoff != 3600)
	    || tm.tm_isdst < 0) {
#ifdef DEBUG
		if (debug)
			printf ("local time zone not set to CET/CEST\n");
#endif
		refclock_report(peer, CEVNT_BADTIME);
		return;
	}
#endif

	pp->lencode = strftime(pp->a_lastcode, BMAX, "%Y %m %d %H %M %S", &tm);

#if defined(_REENTRANT) || defined(_THREAD_SAFE)
	tp = gmtime_r(&t, &tm);
#else
	tp = gmtime(&t);
#endif
	if (!tp) {
		refclock_report(peer, CEVNT_FAULT);
		return;
	}

	get_systime(&pp->lastrec);
	pp->polls++;
	pp->year = tp->tm_year + 1900;
	pp->day = tp->tm_yday + 1;
	pp->hour = tp->tm_hour;
	pp->minute = tp->tm_min;
	pp->second = tp->tm_sec;
	pp->nsec = buf[16] * 31250000;
	if (buf[17] & 1)
		pp->nsec += 500000000;

#ifdef DEBUG
	if (debug)
		printf ("pcf%d: time is %04d/%02d/%02d %02d:%02d:%02d UTC\n",
			unit, pp->year, tp->tm_mon + 1, tp->tm_mday, pp->hour,
			pp->minute, pp->second);
#endif

	if (!refclock_process(pp)) {
		refclock_report(peer, CEVNT_BADTIME);
		return;
	}
	record_clock_stats(&peer->srcadr, pp->a_lastcode);
	if ((buf[1] & 1) && !(pp->sloppyclockflag & CLK_FLAG2))
		pp->leap = LEAP_NOTINSYNC;
	else
		pp->leap = LEAP_NOWARNING;
	pp->lastref = pp->lastrec;
	refclock_receive(peer);
}
#else
int refclock_pcf_bs;
#endif /* REFCLOCK */