freebsd-dev/contrib/ntp/ntpd/refclock_ulink.c
1999-12-09 13:01:21 +00:00

320 lines
8.1 KiB
C

/*
* refclock_ulink - clock driver for Ultralink Model 320 WWVB receivers
* By Dave Strout <dstrout@linuxfoundary.com>
*
* Latest version is always on www.linuxfoundary.com
*
* Based on the Spectracom driver
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#if defined(REFCLOCK) && defined(CLOCK_ULINK)
#include <stdio.h>
#include <ctype.h>
#include <sys/time.h>
#include <time.h>
#include "ntpd.h"
#include "ntp_io.h"
#include "ntp_refclock.h"
#include "ntp_calendar.h"
#include "ntp_stdlib.h"
/*
* This driver supports the Ultralink Model 320 WWVB receiver. The Model 320 is
* an RS-232 powered unit which consists of two parts: a DB-25 shell that contains
* a microprocessor, and an approx 2"x4" plastic box that contains the antenna.
* The two are connected by a 6-wire RJ-25 cable of length up to 1000'. The
* microprocessor steals power from the RS-232 port, which means that the port must
* be kept open all of the time. The unit also has an internal clock for loss of signal
* periods. Claimed accuracy is 0.1 sec.
*
* The timecode format is:
*
* <cr><lf>SQRYYYYDDD+HH:MM:SS.mmLT<cr>
*
* where:
*
* S = 'S' -- sync'd in last hour, '0'-'9' - hours x 10 since last update, else '?'
* Q = Number of correlating time-frames, from 0 to 5
* R = 'R' -- reception in progress, 'N' -- Noisy reception, ' ' -- standby mode
* YYYY = year from 1990 to 2089
* DDD = current day from 1 to 366
* + = '+' if current year is a leap year, else ' '
* HH = UTC hour 0 to 23
* MM = Minutes of current hour from 0 to 59
* SS = Seconds of current minute from 0 to 59
* mm = 10's milliseconds of the current second from 00 to 99
* L = Leap second pending at end of month -- 'I' = inset, 'D'=delete
* T = DST <-> STD transition indicators
*
* Note that this driver does not do anything with the L or T flags.
*
* The M320 also has a 'U' command which returns UT1 correction information. It
* is not used in this driver.
*
*/
/*
* Interface definitions
*/
#define DEVICE "/dev/ulink%d" /* device name and unit */
#define SPEED232 B9600 /* uart speed (9600 baud) */
#define PRECISION (-13) /* precision assumed (about 100 us) */
#define REFID "M320" /* reference ID */
#define DESCRIPTION "Ultralink WWVB Receiver" /* WRU */
#define LENWWVB0 28 /* format 0 timecode length */
#define LENWWVB2 24 /* format 2 timecode length */
#define LENWWVB3 29 /* format 3 timecode length */
#define MONLIN 15 /* number of monitoring lines */
/*
* ULINK unit control structure
*/
struct ulinkunit {
u_char tcswitch; /* timecode switch */
l_fp laststamp; /* last receive timestamp */
u_char lasthour; /* last hour (for monitor) */
u_char linect; /* count ignored lines (for monitor */
};
/*
* Function prototypes
*/
static int ulink_start P((int, struct peer *));
static void ulink_shutdown P((int, struct peer *));
static void ulink_receive P((struct recvbuf *));
static void ulink_poll P((int, struct peer *));
static int fd; /* We need to keep the serial port open to power the ULM320 */
/*
* Transfer vector
*/
struct refclock refclock_ulink = {
ulink_start, /* start up driver */
ulink_shutdown, /* shut down driver */
ulink_poll, /* transmit poll message */
noentry, /* not used (old wwvb_control) */
noentry, /* initialize driver (not used) */
noentry, /* not used (old wwvb_buginfo) */
NOFLAGS /* not used */
};
/*
* ulink_start - open the devices and initialize data for processing
*/
static int
ulink_start(
int unit,
struct peer *peer
)
{
register struct ulinkunit *up;
struct refclockproc *pp;
char device[20];
fprintf(stderr, "Starting Ulink driver\n");
/*
* Open serial port. Use CLK line discipline, if available.
*/
(void)sprintf(device, DEVICE, unit);
if (!(fd = refclock_open(device, SPEED232, LDISC_CLK)))
return (0);
/*
* Allocate and initialize unit structure
*/
if (!(up = (struct ulinkunit *)
emalloc(sizeof(struct ulinkunit)))) {
(void) close(fd);
return (0);
}
memset((char *)up, 0, sizeof(struct ulinkunit));
pp = peer->procptr;
pp->unitptr = (caddr_t)up;
pp->io.clock_recv = ulink_receive;
pp->io.srcclock = (caddr_t)peer;
pp->io.datalen = 0;
pp->io.fd = fd;
if (!io_addclock(&pp->io)) {
(void) close(fd);
free(up);
return (0);
}
/*
* Initialize miscellaneous variables
*/
peer->precision = PRECISION;
peer->flags |= FLAG_BURST;
peer->burst = NSTAGE;
pp->clockdesc = DESCRIPTION;
memcpy((char *)&pp->refid, REFID, 4);
return (1);
}
/*
* ulink_shutdown - shut down the clock
*/
static void
ulink_shutdown(
int unit,
struct peer *peer
)
{
register struct ulinkunit *up;
struct refclockproc *pp;
pp = peer->procptr;
up = (struct ulinkunit *)pp->unitptr;
io_closeclock(&pp->io);
free(up);
close(fd);
}
/*
* ulink_receive - receive data from the serial interface
*/
static void
ulink_receive(
struct recvbuf *rbufp
)
{
struct ulinkunit *up;
struct refclockproc *pp;
struct peer *peer;
l_fp trtmp; /* arrival timestamp */
char syncchar; /* synchronization indicator */
char qualchar; /* quality indicator */
char modechar; /* Modes: 'R'=rx, 'N'=noise, ' '=standby */
char leapchar; /* leap indicator */
int temp; /* int temp */
/*
* Initialize pointers and read the timecode and timestamp
*/
peer = (struct peer *)rbufp->recv_srcclock;
pp = peer->procptr;
up = (struct ulinkunit *)pp->unitptr;
temp = refclock_gtlin(rbufp, pp->a_lastcode, BMAX, &trtmp);
/*
* Note we get a buffer and timestamp for both a <cr> and <lf>,
* but only the <cr> timestamp is retained. Note: in format 0 on
* a Netclock/2 or upgraded 8170 the start bit is delayed 100
* +-50 us relative to the pps; however, on an unmodified 8170
* the start bit can be delayed up to 10 ms. In format 2 the
* reading precision is only to the millisecond. Thus, unless
* you have a pps gadget and don't have to have the year, format
* 0 provides the lowest jitter.
*/
if (temp == 0) {
if (up->tcswitch == 0) {
up->tcswitch = 1;
up->laststamp = trtmp;
} else
up->tcswitch = 0;
return;
}
pp->lencode = temp;
pp->lastrec = up->laststamp;
up->laststamp = trtmp;
up->tcswitch = 1;
#ifdef DEBUG
if (debug)
printf("ulink: timecode %d %s\n", pp->lencode,
pp->a_lastcode);
#endif
/*
* We get down to business, check the timecode format and decode
* its contents. This code uses the timecode length to determine
* whether format 0 or format 2. If the timecode has invalid
* length or is not in proper format, we declare bad format and
* exit.
*/
syncchar = qualchar = leapchar = ' ';
pp->msec = 0;
/*
* Timecode format SQRYYYYDDD+HH:MM:SS.mmLT
*/
sscanf(pp->a_lastcode, "%c%c%c%4d%3d%c%2d:%2d:%2d.%2d",
&syncchar, &qualchar, &modechar, &pp->year, &pp->day,
&leapchar,&pp->hour, &pp->minute, &pp->second,&pp->msec);
pp->msec *= 10; /* M320 returns 10's of msecs */
qualchar = ' ';
/*
* Decode synchronization, quality and leap characters. If
* unsynchronized, set the leap bits accordingly and exit.
* Otherwise, set the leap bits according to the leap character.
* Once synchronized, the dispersion depends only on the
* quality character.
*/
pp->disp = .001;
pp->leap = LEAP_NOWARNING;
/*
* Process the new sample in the median filter and determine the
* timecode timestamp.
*/
if (!refclock_process(pp))
refclock_report(peer, CEVNT_BADTIME);
}
/*
* ulink_poll - called by the transmit procedure
*/
static void
ulink_poll(
int unit,
struct peer *peer
)
{
register struct ulinkunit *up;
struct refclockproc *pp;
char pollchar;
pp = peer->procptr;
up = (struct ulinkunit *)pp->unitptr;
pollchar = 'T';
if (write(pp->io.fd, &pollchar, 1) != 1)
refclock_report(peer, CEVNT_FAULT);
else
pp->polls++;
if (peer->burst > 0)
return;
if (pp->coderecv == pp->codeproc) {
refclock_report(peer, CEVNT_TIMEOUT);
return;
}
record_clock_stats(&peer->srcadr, pp->a_lastcode);
refclock_receive(peer);
peer->burst = NSTAGE;
/*
* If the monitor flag is set (flag4), we dump the internal
* quality table at the first timecode beginning the day.
*/
if (pp->sloppyclockflag & CLK_FLAG4 && pp->hour <
(int)up->lasthour)
up->linect = MONLIN;
up->lasthour = pp->hour;
}
#else
int refclock_ulink_bs;
#endif /* REFCLOCK */