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/*
* refclock_irig - clock driver for the IRIG audio decoder
*/
#if defined(REFCLOCK) && defined(IRIG) && defined(sun)
#include <stdio.h>
#include <ctype.h>
#include <sys/time.h>
#include <sys/ioccom.h>
#include "ntpd.h"
#include "ntp_io.h"
#include "ntp_refclock.h"
#include "ntp_unixtime.h"
#include <sys/bsd_audioirig.h>
#include "ntp_stdlib.h"
/*
* This driver supports the IRIG audio decoder. This clever gadget uses
* a modified BSD audio driver for the Sun SPARCstation which provides
* a timestamp, raw binary timecode, status byte and decoded ASCII
* timecode. The data are represented in the structure in the
* sys/bsd_audioirig.h header file:
*
* struct irig_time {
* struct timeval stamp; timestamp
* u_char bits[13]; 100 IRIG data bits
* u_char status; status byte
* char time[14]; time string (null terminated)
*
* where stamp represents a timestamp at the zero crossing of the index
* marker at the second's epoch, bits is a 13-octet, zero-padded binary-
* coded string representing code elements 1 through 100 in the IRIG-B
* code format, and status is a status bute, The decoded timestamp is a
* 13-octet, null-terminated ASCII string "ddd hh:mm:ss*", where ddd is
* the day of year, hh:mm:ss the time of day and * is a status
* indicator, with " " indicating valid time and "?" indicating
* something wrong.
*
* The timestamp is in Unix timeval format, consisting of two 32-bit
* words, the first of which is the seconds since 1970 and the second is
* the fraction of the second in microseconds. The status byte is zero
* if (a) the input signal is within amplitude tolerances, (b) the raw
* binary timecode contains only valid code elements, (c) 11 position
* identifiers have been found at the expected element positions, (d)
* the clock status byte contained in the timecode is valid, and (e) a
* time determination has been made since the last read() system call.
*
* The 100 elements of the IRIG-B timecode are numbered from 0 through
* 99. Position identifiers occur at elements 0, 9, 19 and every ten
* thereafter to 99. The control function (CF) elements begin at element
* 50 (CF 1) and extend to element 78 (CF 27). The straight-binary-
* seconds (SBS) field, which encodes the seconds of the UTC day, begins
* at element 80 (CF 28) and extends to element 97 (CF 44). The encoding
* of elements 50 (CF 1) through 78 (CF 27) is device dependent. This
* driver presently does not use the CF elements.
*
* Where feasible, the interface should be operated with signature
* control, so that, if the IRIG signal is lost or malformed, the
* interface produces an unmodulated signal, rather than possibly random
* digits. The driver will declare "unsynchronized" in this case.
*
* Spectracom Netclock/2 WWVB Synchronized Clock
*
* Element CF Function
* -------------------------------------
* 55 6 time sync status
* 60-63 10-13 bcd year units
* 65-68 15-18 bcd year tens
*
*/
/*
* IRIG interface definitions
*/
#define DEVICE "/dev/irig%d" /* device name and unit */
#define PRECISION (-13) /* precision assumed (100 us) */
#define REFID "IRIG" /* reference ID */
#define DESCRIPTION "IRIG Audio Decoder" /* WRU */
#define NSAMPLES 3 /* stages of median filter */
#define IRIG_FORMAT 1 /* IRIG timestamp format */
/*
* Imported from ntp_timer module
*/
extern u_long current_time; /* current time (s) */
/*
* Imported from ntpd module
*/
extern int debug; /* global debug flag */
/*
* Function prototypes
*/
static int irig_start P((int, struct peer *));
static void irig_shutdown P((int, struct peer *));
static void irig_poll P((int, struct peer *));
/*
* Transfer vector
*/
struct refclock refclock_irig = {
irig_start, /* start up driver */
irig_shutdown, /* shut down driver */
irig_poll, /* transmit poll message */
noentry, /* not used (old irig_control) */
noentry, /* initialize driver (not used) */
noentry, /* not used (old irig_buginfo) */
NOFLAGS /* not used */
};
/*
* irig_start - open the device and initialize data for processing
*/
static int
irig_start(unit, peer)
int unit;
struct peer *peer;
{
register struct refclockproc *pp;
char device[20];
int fd;
int format = IRIG_FORMAT;
/*
* Open audio device and set format
*/
(void)sprintf(device, DEVICE, unit);
fd = open(device, O_RDONLY | O_NDELAY, 0777);
if (fd == -1) {
syslog(LOG_ERR, "irig_start: open of %s: %m", device);
return (0);
}
if (ioctl(fd, AUDIO_IRIG_OPEN, 0) < 0) {
syslog(LOG_ERR, "irig_start: AUDIO_IRIG_OPEN %m");
close(fd);
return (0);
}
if (ioctl(fd, AUDIO_IRIG_SETFORMAT, (char *)&format) < 0) {
syslog(LOG_ERR, "irig_start: AUDIO_IRIG_SETFORMAT %m",
DEVICE);
close(fd);
return (0);
}
pp = peer->procptr;
pp->io.clock_recv = noentry;
pp->io.srcclock = (caddr_t)peer;
pp->io.datalen = 0;
pp->io.fd = fd;
/*
* Initialize miscellaneous variables
*/
peer->precision = PRECISION;
pp->clockdesc = DESCRIPTION;
memcpy((char *)&pp->refid, REFID, 4);
return (1);
}
/*
* irig_shutdown - shut down the clock
*/
static void
irig_shutdown(unit, peer)
int unit;
struct peer *peer;
{
struct refclockproc *pp;
pp = peer->procptr;
io_closeclock(&pp->io);
}
/*
* irig_poll - called by the transmit procedure
*/
static void
irig_poll(unit, peer)
int unit;
struct peer *peer;
{
struct refclockproc *pp;
struct irig_time buf;
char *cp, *dp;
u_char *dpt;
int i;
pp = peer->procptr;
if (read(pp->io.fd, (char *) &buf, sizeof(buf)) != sizeof(buf)) {
refclock_report(peer, CEVNT_FAULT);
return;
}
pp->polls++;
#ifdef DEBUG
if (debug) {
dpt = (u_char *)&buf;
printf("irig: ");
for (i = 0; i < sizeof(buf); i++)
printf("%02x", *dpt++);
printf("\n");
}
#endif
buf.stamp.tv_sec += JAN_1970;
TVTOTS(&buf.stamp, &pp->lastrec);
cp = buf.time;
dp = pp->lastcode;
for (i = 0; i < sizeof(buf.time); i++)
*dp++ = *cp++;
*--dp = '\0';
pp->lencode = dp - pp->lastcode;
#ifdef DEBUG
if (debug)
printf("irig: time %s timecode %d %s\n",
ulfptoa(&pp->lastrec, 6), pp->lencode,
pp->lastcode);
#endif
record_clock_stats(&peer->srcadr, pp->lastcode);
/*
* Get IRIG time and convert to timestamp format
*/
if (sscanf(pp->lastcode, "%3d %2d:%2d:%2d",
&pp->day, &pp->hour, &pp->minute, &pp->second) != 4) {
refclock_report(peer, CEVNT_BADREPLY);
return;
}
if (pp->lastcode[12] != ' ') {
pp->leap = LEAP_NOTINSYNC;
} else {
pp->leap = 0;
pp->lasttime = current_time;
}
/*
* Process the new sample in the median filter and determine the
* reference clock offset and dispersion. We use lastrec as both
* the reference time and receive time in order to avoid being
* cute, like setting the reference time later than the receive
* time, which may cause a paranoid protocol module to chuck out
* the data.
*/
if (!refclock_process(pp, NSAMPLES, NSAMPLES)) {
refclock_report(peer, CEVNT_BADTIME);
return;
}
refclock_receive(peer, &pp->offset, 0, pp->dispersion,
&pp->lastrec, &pp->lastrec, pp->leap);
}
#endif
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