627 lines
16 KiB
C
627 lines
16 KiB
C
/*
|
|
* refclock_hpgps - clock driver for HP 58503A GPS receiver
|
|
*/
|
|
|
|
#ifdef HAVE_CONFIG_H
|
|
# include <config.h>
|
|
#endif
|
|
|
|
#if defined(REFCLOCK) && defined(CLOCK_HPGPS)
|
|
|
|
#include "ntpd.h"
|
|
#include "ntp_io.h"
|
|
#include "ntp_refclock.h"
|
|
#include "ntp_stdlib.h"
|
|
|
|
#include <stdio.h>
|
|
#include <ctype.h>
|
|
|
|
/* Version 0.1 April 1, 1995
|
|
* 0.2 April 25, 1995
|
|
* tolerant of missing timecode response prompt and sends
|
|
* clear status if prompt indicates error;
|
|
* can use either local time or UTC from receiver;
|
|
* can get receiver status screen via flag4
|
|
*
|
|
* WARNING!: This driver is UNDER CONSTRUCTION
|
|
* Everything in here should be treated with suspicion.
|
|
* If it looks wrong, it probably is.
|
|
*
|
|
* Comments and/or questions to: Dave Vitanye
|
|
* Hewlett Packard Company
|
|
* dave@scd.hp.com
|
|
* (408) 553-2856
|
|
*
|
|
* Thanks to the author of the PST driver, which was the starting point for
|
|
* this one.
|
|
*
|
|
* This driver supports the HP 58503A Time and Frequency Reference Receiver.
|
|
* This receiver uses HP SmartClock (TM) to implement an Enhanced GPS receiver.
|
|
* The receiver accuracy when locked to GPS in normal operation is better
|
|
* than 1 usec. The accuracy when operating in holdover is typically better
|
|
* than 10 usec. per day.
|
|
*
|
|
* The same driver also handles the HP Z3801A which is available surplus
|
|
* from the cell phone industry. It's popular with hams.
|
|
* It needs a different line setup: 19200 baud, 7 data bits, odd parity
|
|
* That is selected by adding "mode 1" to the server line in ntp.conf
|
|
* HP Z3801A code from Jeff Mock added by Hal Murray, Sep 2005
|
|
*
|
|
*
|
|
* The receiver should be operated with factory default settings.
|
|
* Initial driver operation: expects the receiver to be already locked
|
|
* to GPS, configured and able to output timecode format 2 messages.
|
|
*
|
|
* The driver uses the poll sequence :PTIME:TCODE? to get a response from
|
|
* the receiver. The receiver responds with a timecode string of ASCII
|
|
* printing characters, followed by a <cr><lf>, followed by a prompt string
|
|
* issued by the receiver, in the following format:
|
|
* T#yyyymmddhhmmssMFLRVcc<cr><lf>scpi >
|
|
*
|
|
* The driver processes the response at the <cr> and <lf>, so what the
|
|
* driver sees is the prompt from the previous poll, followed by this
|
|
* timecode. The prompt from the current poll is (usually) left unread until
|
|
* the next poll. So (except on the very first poll) the driver sees this:
|
|
*
|
|
* scpi > T#yyyymmddhhmmssMFLRVcc<cr><lf>
|
|
*
|
|
* The T is the on-time character, at 980 msec. before the next 1PPS edge.
|
|
* The # is the timecode format type. We look for format 2.
|
|
* Without any of the CLK or PPS stuff, then, the receiver buffer timestamp
|
|
* at the <cr> is 24 characters later, which is about 25 msec. at 9600 bps,
|
|
* so the first approximation for fudge time1 is nominally -0.955 seconds.
|
|
* This number probably needs adjusting for each machine / OS type, so far:
|
|
* -0.955000 on an HP 9000 Model 712/80 HP-UX 9.05
|
|
* -0.953175 on an HP 9000 Model 370 HP-UX 9.10
|
|
*
|
|
* This receiver also provides a 1PPS signal, but I haven't figured out
|
|
* how to deal with any of the CLK or PPS stuff yet. Stay tuned.
|
|
*
|
|
*/
|
|
|
|
/*
|
|
* Fudge Factors
|
|
*
|
|
* Fudge time1 is used to accomodate the timecode serial interface adjustment.
|
|
* Fudge flag4 can be set to request a receiver status screen summary, which
|
|
* is recorded in the clockstats file.
|
|
*/
|
|
|
|
/*
|
|
* Interface definitions
|
|
*/
|
|
#define DEVICE "/dev/hpgps%d" /* device name and unit */
|
|
#define SPEED232 B9600 /* uart speed (9600 baud) */
|
|
#define SPEED232Z B19200 /* uart speed (19200 baud) */
|
|
#define PRECISION (-10) /* precision assumed (about 1 ms) */
|
|
#define REFID "GPS\0" /* reference ID */
|
|
#define DESCRIPTION "HP 58503A GPS Time and Frequency Reference Receiver"
|
|
|
|
#define SMAX 23*80+1 /* for :SYSTEM:PRINT? status screen response */
|
|
|
|
#define MTZONE 2 /* number of fields in timezone reply */
|
|
#define MTCODET2 12 /* number of fields in timecode format T2 */
|
|
#define NTCODET2 21 /* number of chars to checksum in format T2 */
|
|
|
|
/*
|
|
* Tables to compute the day of year from yyyymmdd timecode.
|
|
* Viva la leap.
|
|
*/
|
|
static int day1tab[] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
|
|
static int day2tab[] = {31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
|
|
|
|
/*
|
|
* Unit control structure
|
|
*/
|
|
struct hpgpsunit {
|
|
int pollcnt; /* poll message counter */
|
|
int tzhour; /* timezone offset, hours */
|
|
int tzminute; /* timezone offset, minutes */
|
|
int linecnt; /* set for expected multiple line responses */
|
|
char *lastptr; /* pointer to receiver response data */
|
|
char statscrn[SMAX]; /* receiver status screen buffer */
|
|
};
|
|
|
|
/*
|
|
* Function prototypes
|
|
*/
|
|
static int hpgps_start (int, struct peer *);
|
|
static void hpgps_shutdown (int, struct peer *);
|
|
static void hpgps_receive (struct recvbuf *);
|
|
static void hpgps_poll (int, struct peer *);
|
|
|
|
/*
|
|
* Transfer vector
|
|
*/
|
|
struct refclock refclock_hpgps = {
|
|
hpgps_start, /* start up driver */
|
|
hpgps_shutdown, /* shut down driver */
|
|
hpgps_poll, /* transmit poll message */
|
|
noentry, /* not used (old hpgps_control) */
|
|
noentry, /* initialize driver */
|
|
noentry, /* not used (old hpgps_buginfo) */
|
|
NOFLAGS /* not used */
|
|
};
|
|
|
|
|
|
/*
|
|
* hpgps_start - open the devices and initialize data for processing
|
|
*/
|
|
static int
|
|
hpgps_start(
|
|
int unit,
|
|
struct peer *peer
|
|
)
|
|
{
|
|
register struct hpgpsunit *up;
|
|
struct refclockproc *pp;
|
|
int fd;
|
|
int speed, ldisc;
|
|
char device[20];
|
|
|
|
/*
|
|
* Open serial port. Use CLK line discipline, if available.
|
|
* Default is HP 58503A, mode arg selects HP Z3801A
|
|
*/
|
|
snprintf(device, sizeof(device), DEVICE, unit);
|
|
ldisc = LDISC_CLK;
|
|
speed = SPEED232;
|
|
/* mode parameter to server config line shares ttl slot */
|
|
if (1 == peer->ttl) {
|
|
ldisc |= LDISC_7O1;
|
|
speed = SPEED232Z;
|
|
}
|
|
fd = refclock_open(device, speed, ldisc);
|
|
if (fd <= 0)
|
|
return (0);
|
|
/*
|
|
* Allocate and initialize unit structure
|
|
*/
|
|
up = emalloc_zero(sizeof(*up));
|
|
pp = peer->procptr;
|
|
pp->io.clock_recv = hpgps_receive;
|
|
pp->io.srcclock = peer;
|
|
pp->io.datalen = 0;
|
|
pp->io.fd = fd;
|
|
if (!io_addclock(&pp->io)) {
|
|
close(fd);
|
|
pp->io.fd = -1;
|
|
free(up);
|
|
return (0);
|
|
}
|
|
pp->unitptr = up;
|
|
|
|
/*
|
|
* Initialize miscellaneous variables
|
|
*/
|
|
peer->precision = PRECISION;
|
|
pp->clockdesc = DESCRIPTION;
|
|
memcpy((char *)&pp->refid, REFID, 4);
|
|
up->tzhour = 0;
|
|
up->tzminute = 0;
|
|
|
|
*up->statscrn = '\0';
|
|
up->lastptr = up->statscrn;
|
|
up->pollcnt = 2;
|
|
|
|
/*
|
|
* Get the identifier string, which is logged but otherwise ignored,
|
|
* and get the local timezone information
|
|
*/
|
|
up->linecnt = 1;
|
|
if (write(pp->io.fd, "*IDN?\r:PTIME:TZONE?\r", 20) != 20)
|
|
refclock_report(peer, CEVNT_FAULT);
|
|
|
|
return (1);
|
|
}
|
|
|
|
|
|
/*
|
|
* hpgps_shutdown - shut down the clock
|
|
*/
|
|
static void
|
|
hpgps_shutdown(
|
|
int unit,
|
|
struct peer *peer
|
|
)
|
|
{
|
|
register struct hpgpsunit *up;
|
|
struct refclockproc *pp;
|
|
|
|
pp = peer->procptr;
|
|
up = pp->unitptr;
|
|
if (-1 != pp->io.fd)
|
|
io_closeclock(&pp->io);
|
|
if (NULL != up)
|
|
free(up);
|
|
}
|
|
|
|
|
|
/*
|
|
* hpgps_receive - receive data from the serial interface
|
|
*/
|
|
static void
|
|
hpgps_receive(
|
|
struct recvbuf *rbufp
|
|
)
|
|
{
|
|
register struct hpgpsunit *up;
|
|
struct refclockproc *pp;
|
|
struct peer *peer;
|
|
l_fp trtmp;
|
|
char tcodechar1; /* identifies timecode format */
|
|
char tcodechar2; /* identifies timecode format */
|
|
char timequal; /* time figure of merit: 0-9 */
|
|
char freqqual; /* frequency figure of merit: 0-3 */
|
|
char leapchar; /* leapsecond: + or 0 or - */
|
|
char servchar; /* request for service: 0 = no, 1 = yes */
|
|
char syncchar; /* time info is invalid: 0 = no, 1 = yes */
|
|
short expectedsm; /* expected timecode byte checksum */
|
|
short tcodechksm; /* computed timecode byte checksum */
|
|
int i,m,n;
|
|
int month, day, lastday;
|
|
char *tcp; /* timecode pointer (skips over the prompt) */
|
|
char prompt[BMAX]; /* prompt in response from receiver */
|
|
|
|
/*
|
|
* Initialize pointers and read the receiver response
|
|
*/
|
|
peer = rbufp->recv_peer;
|
|
pp = peer->procptr;
|
|
up = pp->unitptr;
|
|
*pp->a_lastcode = '\0';
|
|
pp->lencode = refclock_gtlin(rbufp, pp->a_lastcode, BMAX, &trtmp);
|
|
|
|
#ifdef DEBUG
|
|
if (debug)
|
|
printf("hpgps: lencode: %d timecode:%s\n",
|
|
pp->lencode, pp->a_lastcode);
|
|
#endif
|
|
|
|
/*
|
|
* If there's no characters in the reply, we can quit now
|
|
*/
|
|
if (pp->lencode == 0)
|
|
return;
|
|
|
|
/*
|
|
* If linecnt is greater than zero, we are getting information only,
|
|
* such as the receiver identification string or the receiver status
|
|
* screen, so put the receiver response at the end of the status
|
|
* screen buffer. When we have the last line, write the buffer to
|
|
* the clockstats file and return without further processing.
|
|
*
|
|
* If linecnt is zero, we are expecting either the timezone
|
|
* or a timecode. At this point, also write the response
|
|
* to the clockstats file, and go on to process the prompt (if any),
|
|
* timezone, or timecode and timestamp.
|
|
*/
|
|
|
|
|
|
if (up->linecnt-- > 0) {
|
|
if ((int)(pp->lencode + 2) <= (SMAX - (up->lastptr - up->statscrn))) {
|
|
*up->lastptr++ = '\n';
|
|
memcpy(up->lastptr, pp->a_lastcode, pp->lencode);
|
|
up->lastptr += pp->lencode;
|
|
}
|
|
if (up->linecnt == 0)
|
|
record_clock_stats(&peer->srcadr, up->statscrn);
|
|
|
|
return;
|
|
}
|
|
|
|
record_clock_stats(&peer->srcadr, pp->a_lastcode);
|
|
pp->lastrec = trtmp;
|
|
|
|
up->lastptr = up->statscrn;
|
|
*up->lastptr = '\0';
|
|
up->pollcnt = 2;
|
|
|
|
/*
|
|
* We get down to business: get a prompt if one is there, issue
|
|
* a clear status command if it contains an error indication.
|
|
* Next, check for either the timezone reply or the timecode reply
|
|
* and decode it. If we don't recognize the reply, or don't get the
|
|
* proper number of decoded fields, or get an out of range timezone,
|
|
* or if the timecode checksum is bad, then we declare bad format
|
|
* and exit.
|
|
*
|
|
* Timezone format (including nominal prompt):
|
|
* scpi > -H,-M<cr><lf>
|
|
*
|
|
* Timecode format (including nominal prompt):
|
|
* scpi > T2yyyymmddhhmmssMFLRVcc<cr><lf>
|
|
*
|
|
*/
|
|
|
|
strlcpy(prompt, pp->a_lastcode, sizeof(prompt));
|
|
tcp = strrchr(pp->a_lastcode,'>');
|
|
if (tcp == NULL)
|
|
tcp = pp->a_lastcode;
|
|
else
|
|
tcp++;
|
|
prompt[tcp - pp->a_lastcode] = '\0';
|
|
while ((*tcp == ' ') || (*tcp == '\t')) tcp++;
|
|
|
|
/*
|
|
* deal with an error indication in the prompt here
|
|
*/
|
|
if (strrchr(prompt,'E') > strrchr(prompt,'s')){
|
|
#ifdef DEBUG
|
|
if (debug)
|
|
printf("hpgps: error indicated in prompt: %s\n", prompt);
|
|
#endif
|
|
if (write(pp->io.fd, "*CLS\r\r", 6) != 6)
|
|
refclock_report(peer, CEVNT_FAULT);
|
|
}
|
|
|
|
/*
|
|
* make sure we got a timezone or timecode format and
|
|
* then process accordingly
|
|
*/
|
|
m = sscanf(tcp,"%c%c", &tcodechar1, &tcodechar2);
|
|
|
|
if (m != 2){
|
|
#ifdef DEBUG
|
|
if (debug)
|
|
printf("hpgps: no format indicator\n");
|
|
#endif
|
|
refclock_report(peer, CEVNT_BADREPLY);
|
|
return;
|
|
}
|
|
|
|
switch (tcodechar1) {
|
|
|
|
case '+':
|
|
case '-':
|
|
m = sscanf(tcp,"%d,%d", &up->tzhour, &up->tzminute);
|
|
if (m != MTZONE) {
|
|
#ifdef DEBUG
|
|
if (debug)
|
|
printf("hpgps: only %d fields recognized in timezone\n", m);
|
|
#endif
|
|
refclock_report(peer, CEVNT_BADREPLY);
|
|
return;
|
|
}
|
|
if ((up->tzhour < -12) || (up->tzhour > 13) ||
|
|
(up->tzminute < -59) || (up->tzminute > 59)){
|
|
#ifdef DEBUG
|
|
if (debug)
|
|
printf("hpgps: timezone %d, %d out of range\n",
|
|
up->tzhour, up->tzminute);
|
|
#endif
|
|
refclock_report(peer, CEVNT_BADREPLY);
|
|
return;
|
|
}
|
|
return;
|
|
|
|
case 'T':
|
|
break;
|
|
|
|
default:
|
|
#ifdef DEBUG
|
|
if (debug)
|
|
printf("hpgps: unrecognized reply format %c%c\n",
|
|
tcodechar1, tcodechar2);
|
|
#endif
|
|
refclock_report(peer, CEVNT_BADREPLY);
|
|
return;
|
|
} /* end of tcodechar1 switch */
|
|
|
|
|
|
switch (tcodechar2) {
|
|
|
|
case '2':
|
|
m = sscanf(tcp,"%*c%*c%4d%2d%2d%2d%2d%2d%c%c%c%c%c%2hx",
|
|
&pp->year, &month, &day, &pp->hour, &pp->minute, &pp->second,
|
|
&timequal, &freqqual, &leapchar, &servchar, &syncchar,
|
|
&expectedsm);
|
|
n = NTCODET2;
|
|
|
|
if (m != MTCODET2){
|
|
#ifdef DEBUG
|
|
if (debug)
|
|
printf("hpgps: only %d fields recognized in timecode\n", m);
|
|
#endif
|
|
refclock_report(peer, CEVNT_BADREPLY);
|
|
return;
|
|
}
|
|
break;
|
|
|
|
default:
|
|
#ifdef DEBUG
|
|
if (debug)
|
|
printf("hpgps: unrecognized timecode format %c%c\n",
|
|
tcodechar1, tcodechar2);
|
|
#endif
|
|
refclock_report(peer, CEVNT_BADREPLY);
|
|
return;
|
|
} /* end of tcodechar2 format switch */
|
|
|
|
/*
|
|
* Compute and verify the checksum.
|
|
* Characters are summed starting at tcodechar1, ending at just
|
|
* before the expected checksum. Bail out if incorrect.
|
|
*/
|
|
tcodechksm = 0;
|
|
while (n-- > 0) tcodechksm += *tcp++;
|
|
tcodechksm &= 0x00ff;
|
|
|
|
if (tcodechksm != expectedsm) {
|
|
#ifdef DEBUG
|
|
if (debug)
|
|
printf("hpgps: checksum %2hX doesn't match %2hX expected\n",
|
|
tcodechksm, expectedsm);
|
|
#endif
|
|
refclock_report(peer, CEVNT_BADREPLY);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* Compute the day of year from the yyyymmdd format.
|
|
*/
|
|
if (month < 1 || month > 12 || day < 1) {
|
|
refclock_report(peer, CEVNT_BADTIME);
|
|
return;
|
|
}
|
|
|
|
if ( ! isleap_4(pp->year) ) { /* Y2KFixes */
|
|
/* not a leap year */
|
|
if (day > day1tab[month - 1]) {
|
|
refclock_report(peer, CEVNT_BADTIME);
|
|
return;
|
|
}
|
|
for (i = 0; i < month - 1; i++) day += day1tab[i];
|
|
lastday = 365;
|
|
} else {
|
|
/* a leap year */
|
|
if (day > day2tab[month - 1]) {
|
|
refclock_report(peer, CEVNT_BADTIME);
|
|
return;
|
|
}
|
|
for (i = 0; i < month - 1; i++) day += day2tab[i];
|
|
lastday = 366;
|
|
}
|
|
|
|
/*
|
|
* Deal with the timezone offset here. The receiver timecode is in
|
|
* local time = UTC + :PTIME:TZONE, so SUBTRACT the timezone values.
|
|
* For example, Pacific Standard Time is -8 hours , 0 minutes.
|
|
* Deal with the underflows and overflows.
|
|
*/
|
|
pp->minute -= up->tzminute;
|
|
pp->hour -= up->tzhour;
|
|
|
|
if (pp->minute < 0) {
|
|
pp->minute += 60;
|
|
pp->hour--;
|
|
}
|
|
if (pp->minute > 59) {
|
|
pp->minute -= 60;
|
|
pp->hour++;
|
|
}
|
|
if (pp->hour < 0) {
|
|
pp->hour += 24;
|
|
day--;
|
|
if (day < 1) {
|
|
pp->year--;
|
|
if ( isleap_4(pp->year) ) /* Y2KFixes */
|
|
day = 366;
|
|
else
|
|
day = 365;
|
|
}
|
|
}
|
|
|
|
if (pp->hour > 23) {
|
|
pp->hour -= 24;
|
|
day++;
|
|
if (day > lastday) {
|
|
pp->year++;
|
|
day = 1;
|
|
}
|
|
}
|
|
|
|
pp->day = day;
|
|
|
|
/*
|
|
* Decode the MFLRV indicators.
|
|
* NEED TO FIGURE OUT how to deal with the request for service,
|
|
* time quality, and frequency quality indicators some day.
|
|
*/
|
|
if (syncchar != '0') {
|
|
pp->leap = LEAP_NOTINSYNC;
|
|
}
|
|
else {
|
|
pp->leap = LEAP_NOWARNING;
|
|
switch (leapchar) {
|
|
|
|
case '0':
|
|
break;
|
|
|
|
/* See http://bugs.ntp.org/1090
|
|
* Ignore leap announcements unless June or December.
|
|
* Better would be to use :GPSTime? to find the month,
|
|
* but that seems too likely to introduce other bugs.
|
|
*/
|
|
case '+':
|
|
if ((month==6) || (month==12))
|
|
pp->leap = LEAP_ADDSECOND;
|
|
break;
|
|
|
|
case '-':
|
|
if ((month==6) || (month==12))
|
|
pp->leap = LEAP_DELSECOND;
|
|
break;
|
|
|
|
default:
|
|
#ifdef DEBUG
|
|
if (debug)
|
|
printf("hpgps: unrecognized leap indicator: %c\n",
|
|
leapchar);
|
|
#endif
|
|
refclock_report(peer, CEVNT_BADTIME);
|
|
return;
|
|
} /* end of leapchar switch */
|
|
}
|
|
|
|
/*
|
|
* 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)) {
|
|
refclock_report(peer, CEVNT_BADTIME);
|
|
return;
|
|
}
|
|
pp->lastref = pp->lastrec;
|
|
refclock_receive(peer);
|
|
|
|
/*
|
|
* If CLK_FLAG4 is set, ask for the status screen response.
|
|
*/
|
|
if (pp->sloppyclockflag & CLK_FLAG4){
|
|
up->linecnt = 22;
|
|
if (write(pp->io.fd, ":SYSTEM:PRINT?\r", 15) != 15)
|
|
refclock_report(peer, CEVNT_FAULT);
|
|
}
|
|
}
|
|
|
|
|
|
/*
|
|
* hpgps_poll - called by the transmit procedure
|
|
*/
|
|
static void
|
|
hpgps_poll(
|
|
int unit,
|
|
struct peer *peer
|
|
)
|
|
{
|
|
register struct hpgpsunit *up;
|
|
struct refclockproc *pp;
|
|
|
|
/*
|
|
* Time to poll the clock. The HP 58503A responds to a
|
|
* ":PTIME:TCODE?" by returning a timecode in the format specified
|
|
* above. If nothing is heard from the clock for two polls,
|
|
* declare a timeout and keep going.
|
|
*/
|
|
pp = peer->procptr;
|
|
up = pp->unitptr;
|
|
if (up->pollcnt == 0)
|
|
refclock_report(peer, CEVNT_TIMEOUT);
|
|
else
|
|
up->pollcnt--;
|
|
if (write(pp->io.fd, ":PTIME:TCODE?\r", 14) != 14) {
|
|
refclock_report(peer, CEVNT_FAULT);
|
|
}
|
|
else
|
|
pp->polls++;
|
|
}
|
|
|
|
#else
|
|
int refclock_hpgps_bs;
|
|
#endif /* REFCLOCK */
|