Patrick Welche <prlw1@cam.ac.uk>

[netbsd-mini2440.git] / external / bsd / ntp / dist / ntpd / refclock_true.c

/*      $NetBSD$        */

/*
 * refclock_true - clock driver for the Kinemetrics Truetime receivers
 *      Receiver Version 3.0C - tested plain, with CLKLDISC
 *      Developement work being done:
 *      - Properly handle varying satellite positions (more acurately)
 *      - Integrate GPSTM and/or OMEGA and/or TRAK and/or ??? drivers
 */

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

#if defined(REFCLOCK) && defined(CLOCK_TRUETIME)

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

#include <stdio.h>
#include <ctype.h>

/* This should be an atom clock but those are very hard to build.
 *
 * The PCL720 from P C Labs has an Intel 8253 lookalike, as well as a bunch
 * of TTL input and output pins, all brought out to the back panel.  If you
 * wire a PPS signal (such as the TTL PPS coming out of a GOES or other
 * Kinemetrics/Truetime clock) to the 8253's GATE0, and then also wire the
 * 8253's OUT0 to the PCL720's INPUT3.BIT0, then we can read CTR0 to get the
 * number of uSecs since the last PPS upward swing, mediated by reading OUT0
 * to find out if the counter has wrapped around (this happens if more than
 * 65535us (65ms) elapses between the PPS event and our being called.)
 */
#ifdef CLOCK_PPS720
# undef min     /* XXX */
# undef max     /* XXX */
# include <machine/inline.h>
# include <sys/pcl720.h>
# include <sys/i8253.h>
# define PCL720_IOB 0x2a0       /* XXX */
# define PCL720_CTR 0           /* XXX */
#endif

/*
 * Support for Kinemetrics Truetime Receivers
 *      GOES
 *      GPS/TM-TMD
 *      XL-DC           (a 151-602-210, reported by the driver as a GPS/TM-TMD)
 *      GPS-800 TCU     (an 805-957 with the RS232 Talker/Listener module)
 *      OM-DC:          getting stale ("OMEGA")
 *
 * Most of this code is originally from refclock_wwvb.c with thanks.
 * It has been so mangled that wwvb is not a recognizable ancestor.
 *
 * Timcode format: ADDD:HH:MM:SSQCL
 *      A - control A           (this is stripped before we see it)
 *      Q - Quality indication  (see below)
 *      C - Carriage return
 *      L - Line feed
 *
 * Quality codes indicate possible error of
 *   468-DC GOES Receiver:
 *   GPS-TM/TMD Receiver: (default quality codes for XL-DC)
 *       ?     +/- 1  milliseconds      #     +/- 100 microseconds
 *       *     +/- 10 microseconds      .     +/- 1   microsecond
 *     space   less than 1 microsecond
 *   OM-DC OMEGA Receiver: (default quality codes for OMEGA)
 *   WARNING OMEGA navigation system is no longer existent
 *       >     >+- 5 seconds
 *       ?     >+/- 500 milliseconds    #     >+/- 50 milliseconds
 *       *     >+/- 5 milliseconds      .     >+/- 1 millisecond
 *      A-H    less than 1 millisecond.  Character indicates which station
 *             is being received as follows:
 *             A = Norway, B = Liberia, C = Hawaii, D = North Dakota,
 *             E = La Reunion, F = Argentina, G = Australia, H = Japan.
 *
 * The carriage return start bit begins on 0 seconds and extends to 1 bit time.
 *
 * Notes on 468-DC and OMEGA receiver:
 *
 * Send the clock a 'R' or 'C' and once per second a timestamp will
 * appear.  Send a 'P' to get the satellite position once (GOES only.)
 *
 * Notes on the 468-DC receiver:
 *
 * Since the old east/west satellite locations are only historical, you can't
 * set your clock propagation delay settings correctly and still use
 * automatic mode. The manual says to use a compromise when setting the
 * switches. This results in significant errors. The solution; use fudge
 * time1 and time2 to incorporate corrections. If your clock is set for
 * 50 and it should be 58 for using the west and 46 for using the east,
 * use the line
 *
 * fudge 127.127.5.0 time1 +0.008 time2 -0.004
 *
 * This corrects the 4 milliseconds advance and 8 milliseconds retard
 * needed. The software will ask the clock which satellite it sees.
 *
 * Ntp.conf parameters:
 * time1 - offset applied to samples when reading WEST satellite (default = 0)
 * time2 - offset applied to samples when reading EAST satellite (default = 0)
 * val1  - stratum to assign to this clock (default = 0)
 * val2  - refid assigned to this clock (default = "TRUE", see below)
 * flag1 - will silence the clock side of ntpd, just reading the clock
 *         without trying to write to it.  (default = 0)
 * flag2 - generate a debug file /tmp/true%d.
 * flag3 - enable ppsclock streams module
 * flag4 - use the PCL-720 (BSD/OS only)
 */


/*
 * Definitions
 */
#define DEVICE          "/dev/true%d"
#define SPEED232        B9600   /* 9600 baud */

/*
 * Radio interface parameters
 */
#define PRECISION       (-10)   /* precision assumed (about 1 ms) */
#define REFID           "TRUE"  /* reference id */
#define DESCRIPTION     "Kinemetrics/TrueTime Receiver"

/*
 * Tags which station (satellite) we see
 */
#define GOES_WEST       0       /* Default to WEST satellite and apply time1 */
#define GOES_EAST       1       /* until you discover otherwise */

/*
 * used by the state machine
 */
enum true_event {e_Init, e_Huh, e_F18, e_F50, e_F51, e_Satellite,
                 e_Poll, e_Location, e_TS, e_Max};
const char *events[] = {"Init", "Huh", "F18", "F50", "F51", "Satellite",
                        "Poll", "Location", "TS"};
#define eventStr(x) (((int)x<(int)e_Max) ? events[(int)x] : "?")

enum true_state {s_Base, s_InqTM, s_InqTCU, s_InqOmega, s_InqGOES,
                 s_Init, s_F18, s_F50, s_Start, s_Auto, s_Max};
const char *states[] = {"Base", "InqTM", "InqTCU", "InqOmega", "InqGOES",
                        "Init", "F18", "F50", "Start", "Auto"};
#define stateStr(x) (((int)x<(int)s_Max) ? states[(int)x] : "?")

enum true_type  {t_unknown, t_goes, t_tm, t_tcu, t_omega, t_Max};
const char *types[] = {"unknown", "goes", "tm", "tcu", "omega"};
#define typeStr(x) (((int)x<(int)t_Max) ? types[(int)x] : "?")

/*
 * unit control structure
 */
struct true_unit {
        unsigned int    pollcnt;        /* poll message counter */
        unsigned int    station;        /* which station we are on */
        unsigned int    polled;         /* Hand in a time sample? */
        enum true_state state;          /* state machine */
        enum true_type  type;           /* what kind of clock is it? */
        int             unit;           /* save an extra copy of this */
        FILE            *debug;         /* debug logging file */
#ifdef CLOCK_PPS720
        int             pcl720init;     /* init flag for PCL 720 */
#endif
};

/*
 * Function prototypes
 */
static  int     true_start      (int, struct peer *);
static  void    true_shutdown   (int, struct peer *);
static  void    true_receive    (struct recvbuf *);
static  void    true_poll       (int, struct peer *);
static  void    true_send       (struct peer *, const char *);
static  void    true_doevent    (struct peer *, enum true_event);

#ifdef CLOCK_PPS720
static  u_long  true_sample720  (void);
#endif

/*
 * Transfer vector
 */
struct  refclock refclock_true = {
        true_start,             /* start up driver */
        true_shutdown,          /* shut down driver */
        true_poll,              /* transmit poll message */
        noentry,                /* not used (old true_control) */
        noentry,                /* initialize driver (not used) */
        noentry,                /* not used (old true_buginfo) */
        NOFLAGS                 /* not used */
};


#if !defined(__STDC__)
# define true_debug (void)
#else
static void
true_debug(struct peer *peer, const char *fmt, ...)
{
        va_list ap;
        int want_debugging, now_debugging;
        struct refclockproc *pp;
        struct true_unit *up;

        va_start(ap, fmt);
        pp = peer->procptr;
        up = (struct true_unit *)pp->unitptr;

        want_debugging = (pp->sloppyclockflag & CLK_FLAG2) != 0;
        now_debugging = (up->debug != NULL);
        if (want_debugging != now_debugging)
        {
                if (want_debugging) {
                    char filename[40];
                    int fd;

                    snprintf(filename, sizeof(filename), "/tmp/true%d.debug", up->unit);
                    fd = open(filename, O_CREAT | O_WRONLY | O_EXCL, 0600);
                    if (fd >= 0 && (up->debug = fdopen(fd, "r+"))) {
#ifdef HAVE_SETVBUF
                            static char buf[BUFSIZ];
                            setvbuf(up->debug, buf, _IOLBF, BUFSIZ);
#else
                            setlinebuf(up->debug);
#endif
                    }
            } else {
                    fclose(up->debug);
                    up->debug = NULL;
            }
        }

        if (up->debug) {
                fprintf(up->debug, "true%d: ", up->unit);
                vfprintf(up->debug, fmt, ap);
        }
        va_end(ap);
}
#endif /*STDC*/

/*
 * true_start - open the devices and initialize data for processing
 */
static int
true_start(
        int unit,
        struct peer *peer
        )
{
        register struct true_unit *up;
        struct refclockproc *pp;
        char device[40];
        int fd;

        /*
         * Open serial port
         */
        (void)snprintf(device, sizeof(device), DEVICE, unit);
        if (!(fd = refclock_open(device, SPEED232, LDISC_CLK)))
            return (0);

        /*
         * Allocate and initialize unit structure
         */
        if (!(up = (struct true_unit *)
              emalloc(sizeof(struct true_unit)))) {
                (void) close(fd);
                return (0);
        }
        memset((char *)up, 0, sizeof(struct true_unit));
        pp = peer->procptr;
        pp->io.clock_recv = true_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);
        }
        pp->unitptr = (caddr_t)up;

        /*
         * Initialize miscellaneous variables
         */
        peer->precision = PRECISION;
        pp->clockdesc = DESCRIPTION;
        memcpy((char *)&pp->refid, REFID, 4);
        up->pollcnt = 2;
        up->type = t_unknown;
        up->state = s_Base;
        true_doevent(peer, e_Init);
        return (1);
}

/*
 * true_shutdown - shut down the clock
 */
static void
true_shutdown(
        int unit,
        struct peer *peer
        )
{
        register struct true_unit *up;
        struct refclockproc *pp;

        pp = peer->procptr;
        up = (struct true_unit *)pp->unitptr;
        io_closeclock(&pp->io);
        free(up);
}


/*
 * true_receive - receive data from the serial interface on a clock
 */
static void
true_receive(
        struct recvbuf *rbufp
        )
{
        register struct true_unit *up;
        struct refclockproc *pp;
        struct peer *peer;
        u_short new_station;
        char synced;
        int i;
        int lat, lon, off;      /* GOES Satellite position */
        /* Use these variable to hold data until we decide its worth keeping */
        char    rd_lastcode[BMAX];
        l_fp    rd_tmp;
        u_short rd_lencode;

        /*
         * Get the clock this applies to and pointers to the data.
         */
        peer = (struct peer *)rbufp->recv_srcclock;
        pp = peer->procptr;
        up = (struct true_unit *)pp->unitptr;

        /*
         * Read clock output.  Automatically handles STREAMS, CLKLDISC.
         */
        rd_lencode = refclock_gtlin(rbufp, rd_lastcode, BMAX, &rd_tmp);
        rd_lastcode[rd_lencode] = '\0';

        /*
         * There is a case where <cr><lf> generates 2 timestamps.
         */
        if (rd_lencode == 0)
            return;
        pp->lencode = rd_lencode;
        strcpy(pp->a_lastcode, rd_lastcode);
        pp->lastrec = rd_tmp;
        true_debug(peer, "receive(%s) [%d]\n", pp->a_lastcode, pp->lencode);

        up->pollcnt = 2;
        record_clock_stats(&peer->srcadr, pp->a_lastcode);

        /*
         * We get down to business, check the timecode format and decode
         * its contents. This code decodes a multitude of different
         * clock messages. Timecodes are processed if needed. All replies
         * will be run through the state machine to tweak driver options
         * and program the clock.
         */

        /*
         * Clock misunderstood our last command?
         */
        if (pp->a_lastcode[0] == '?' ||
            strcmp(pp->a_lastcode, "ERROR 05 NO SUCH FUNCTION") == 0) {
                true_doevent(peer, e_Huh);
                return;
        }

        /*
         * Timecode: "nnnnn+nnn-nnn"
         * (from GOES clock when asked about satellite position)
         */
        if ((pp->a_lastcode[5] == '+' || pp->a_lastcode[5] == '-') &&
            (pp->a_lastcode[9] == '+' || pp->a_lastcode[9] == '-') &&
            sscanf(pp->a_lastcode, "%5d%*c%3d%*c%3d", &lon, &lat, &off) == 3
            ) {
                const char *label = "Botch!";

                /*
                 * This is less than perfect.  Call the (satellite)
                 * either EAST or WEST and adjust slop accodingly
                 * Perfectionists would recalculate the exact delay
                 * and adjust accordingly...
                 */
                if (lon > 7000 && lon < 14000) {
                        if (lon < 10000) {
                                new_station = GOES_EAST;
                                label = "EAST";
                        } else {
                                new_station = GOES_WEST;
                                label = "WEST";
                        }
                                
                        if (new_station != up->station) {
                                double dtemp;

                                dtemp = pp->fudgetime1;
                                pp->fudgetime1 = pp->fudgetime2;
                                pp->fudgetime2 = dtemp;
                                up->station = new_station;
                        }
                }
                else {
                        /*refclock_report(peer, CEVNT_BADREPLY);*/
                        label = "UNKNOWN";
                }
                true_debug(peer, "GOES: station %s\n", label);
                true_doevent(peer, e_Satellite);
                return;
        }

        /*
         * Timecode: "Fnn"
         * (from TM/TMD clock when it wants to tell us what it's up to.)
         */
        if (sscanf(pp->a_lastcode, "F%2d", &i) == 1 && i > 0 && i < 80) {
                switch (i) {
                    case 50:
                        true_doevent(peer, e_F50);
                        break;
                    case 51:
                        true_doevent(peer, e_F51);
                        break;
                    default:
                        true_debug(peer, "got F%02d - ignoring\n", i);
                        break;
                }
                return;
        }

        /*
         * Timecode: " TRUETIME Mk III" or " TRUETIME XL"
         * (from a TM/TMD/XL clock during initialization.)
         */
        if (strcmp(pp->a_lastcode, " TRUETIME Mk III") == 0 ||
            strncmp(pp->a_lastcode, " TRUETIME XL", 12) == 0) {
                true_doevent(peer, e_F18);
                NLOG(NLOG_CLOCKSTATUS) {
                        msyslog(LOG_INFO, "TM/TMD/XL: %s", pp->a_lastcode);
                }
                return;
        }

        /*
         * Timecode: "N03726428W12209421+000033"
         *                      1         2
         *            0123456789012345678901234
         * (from a TCU during initialization)
         */
        if ((pp->a_lastcode[0] == 'N' || pp->a_lastcode[0] == 'S') &&
            (pp->a_lastcode[9] == 'W' || pp->a_lastcode[9] == 'E') &&
            pp->a_lastcode[18] == '+') {
                true_doevent(peer, e_Location);
                NLOG(NLOG_CLOCKSTATUS) {
                        msyslog(LOG_INFO, "TCU-800: %s", pp->a_lastcode);
                }
                return;
        }
        /*
         * Timecode: "ddd:hh:mm:ssQ"
         * (from all clocks supported by this driver.)
         */
        if (pp->a_lastcode[3] == ':' &&
            pp->a_lastcode[6] == ':' &&
            pp->a_lastcode[9] == ':' &&
            sscanf(pp->a_lastcode, "%3d:%2d:%2d:%2d%c",
                   &pp->day, &pp->hour, &pp->minute,
                   &pp->second, &synced) == 5) {

                /*
                 * Adjust the synchronize indicator according to timecode
                 * say were OK, and then say not if we really are not OK
                 */
                if (synced == '>' || synced == '#' || synced == '?')
                    pp->leap = LEAP_NOTINSYNC;
                else
                    pp->leap = LEAP_NOWARNING;

                true_doevent(peer, e_TS);

#ifdef CLOCK_PPS720
                /* If it's taken more than 65ms to get here, we'll lose. */
                if ((pp->sloppyclockflag & CLK_FLAG4) && up->pcl720init) {
                        l_fp   off;

#ifdef CLOCK_ATOM
                        /*
                         * find out what time it really is. Include
                         * the count from the PCL720
                         */
                        if (!clocktime(pp->day, pp->hour, pp->minute, 
                                       pp->second, GMT, pp->lastrec.l_ui, 
                                       &pp->yearstart, &off.l_ui)) {
                                refclock_report(peer, CEVNT_BADTIME);
                                return;
                        }
                        off.l_uf = 0;
#endif

                        pp->usec = true_sample720();
#ifdef CLOCK_ATOM
                        TVUTOTSF(pp->usec, off.l_uf);
#endif

                        /*
                         * Stomp all over the timestamp that was pulled out
                         * of the input stream. It's irrelevant since we've
                         * adjusted the input time to reflect now (via pp->usec)
                         * rather than when the data was collected.
                         */
                        get_systime(&pp->lastrec);
#ifdef CLOCK_ATOM
                        /*
                         * Create a true offset for feeding to pps_sample()
                         */
                        L_SUB(&off, &pp->lastrec);

                        pps_sample(peer, &off);
#endif
                        true_debug(peer, "true_sample720: %luus\n", pp->usec);
                }
#endif

                /*
                 * The clock will blurt a timecode every second but we only
                 * want one when polled.  If we havn't been polled, bail out.
                 */
                if (!up->polled)
                    return;

                true_doevent(peer, e_Poll);
                if (!refclock_process(pp)) {
                        refclock_report(peer, CEVNT_BADTIME);
                        return;
                }
                /*
                 * If clock is good we send a NOMINAL message so that
                 * any previous BAD messages are nullified
                 */
                pp->lastref = pp->lastrec;
                refclock_receive(peer);
                refclock_report(peer, CEVNT_NOMINAL);

                /*
                 * We have succedded in answering the poll.
                 * Turn off the flag and return
                 */
                up->polled = 0;

                return;
        }

        /*
         * No match to known timecodes, report failure and return
         */
        refclock_report(peer, CEVNT_BADREPLY);
        return;
}


/*
 * true_send - time to send the clock a signal to cough up a time sample
 */
static void
true_send(
        struct peer *peer,
        const char *cmd
        )
{
        struct refclockproc *pp;

        pp = peer->procptr;
        if (!(pp->sloppyclockflag & CLK_FLAG1)) {
                register int len = strlen(cmd);

                true_debug(peer, "Send '%s'\n", cmd);
                if (write(pp->io.fd, cmd, (unsigned)len) != len)
                    refclock_report(peer, CEVNT_FAULT);
                else
                    pp->polls++;
        }
}


/*
 * state machine for initializing and controlling a clock
 */
static void
true_doevent(
        struct peer *peer,
        enum true_event event
        )
{
        struct true_unit *up;
        struct refclockproc *pp;

        pp = peer->procptr;
        up = (struct true_unit *)pp->unitptr;
        if (event != e_TS) {
                NLOG(NLOG_CLOCKSTATUS) {
                        msyslog(LOG_INFO, "TRUE: clock %s, state %s, event %s",
                                typeStr(up->type),
                                stateStr(up->state),
                                eventStr(event));
                }
        }
        true_debug(peer, "clock %s, state %s, event %s\n",
                   typeStr(up->type), stateStr(up->state), eventStr(event));
        switch (up->type) {
            case t_goes:
                switch (event) {
                    case e_Init:        /* FALLTHROUGH */
                    case e_Satellite:
                        /*
                         * Switch back to on-second time codes and return.
                         */
                        true_send(peer, "C");
                        up->state = s_Start;
                        break;
                    case e_Poll:
                        /*
                         * After each poll, check the station (satellite).
                         */
                        true_send(peer, "P");
                        /* No state change needed. */
                        break;
                    default:
                        break;
                }
                /* FALLTHROUGH */
            case t_omega:
                switch (event) {
                    case e_Init:
                        true_send(peer, "C");
                        up->state = s_Start;
                        break;
                    case e_TS:
                        if (up->state != s_Start && up->state != s_Auto) {
                                true_send(peer, "\03\r");
                                break;
                        }
                        up->state = s_Auto;
                        break;
                    default:
                        break;
                }
                break;
            case t_tm:
                switch (event) {
                    case e_Init:
                        true_send(peer, "F18\r");
                        up->state = s_Init;
                        break;
                    case e_F18:
                        true_send(peer, "F50\r");
                        up->state = s_F18;
                        break;
                    case e_F50:
                        true_send(peer, "F51\r");
                        up->state = s_F50;
                        break;
                    case e_F51:
                        true_send(peer, "F08\r");
                        up->state = s_Start;
                        break;
                    case e_TS:
                        if (up->state != s_Start && up->state != s_Auto) {
                                true_send(peer, "\03\r");
                                break;
                        }
                        up->state = s_Auto;
                        break;
                    default:
                        break;
                }
                break;
            case t_tcu:
                switch (event) {
                    case e_Init:
                        true_send(peer, "MD3\r");       /* GPS Synch'd Gen. */
                        true_send(peer, "TSU\r");       /* UTC, not GPS. */
                        true_send(peer, "AU\r");        /* Auto Timestamps. */
                        up->state = s_Start;
                        break;
                    case e_TS:
                        if (up->state != s_Start && up->state != s_Auto) {
                                true_send(peer, "\03\r");
                                break;
                        }
                        up->state = s_Auto;
                        break;
                    default:
                        break;
                }
                break;
            case t_unknown:
                switch (up->state) {
                    case s_Base:
                        if (event != e_Init)
                            abort();
                        true_send(peer, "P\r");
                        up->state = s_InqGOES;
                        break;
                    case s_InqGOES:
                        switch (event) {
                            case e_Satellite:
                                up->type = t_goes;
                                true_doevent(peer, e_Init);
                                break;
                            case e_Init:        /*FALLTHROUGH*/
                            case e_Huh: /*FALLTHROUGH*/
                            case e_TS:
                                up->state = s_InqOmega;
                                true_send(peer, "C\r");
                                break;
                            default:
                                abort();
                        }
                        break;
                    case s_InqOmega:
                        switch (event) {
                            case e_TS:
                                up->type = t_omega;
                                up->state = s_Auto;     /* Inq side-effect. */
                                break;
                            case e_Init:        /*FALLTHROUGH*/
                            case e_Huh:
                                up->state = s_InqTM;
                                true_send(peer, "F18\r");
                                break;
                            default:
                                abort();
                        }
                        break;
                    case s_InqTM:
                        switch (event) {
                            case e_F18:
                                up->type = t_tm;
                                true_doevent(peer, e_Init);
                                break;
                            case e_Init:        /*FALLTHROUGH*/
                            case e_Huh:
                                true_send(peer, "PO\r");
                                up->state = s_InqTCU;
                                break;
                            default:
                                abort();
                        }
                        break;
                    case s_InqTCU:
                        switch (event) {
                            case e_Location:
                                up->type = t_tcu;
                                true_doevent(peer, e_Init);
                                break;
                            case e_Init:        /*FALLTHROUGH*/
                            case e_Huh:
                                up->state = s_Base;
                                sleep(1);       /* XXX */
                                break;
                            default:
                                abort();
                        }
                        break;
                        /*
                         * An expedient hack to prevent lint complaints,
                         * these don't actually need to be used here...
                         */
                    case s_Init:
                    case s_F18:
                    case s_F50:
                    case s_Start:
                    case s_Auto:
                    case s_Max:
                        msyslog(LOG_INFO, "TRUE: state %s is unexpected!", stateStr(up->state));
                }
                break;
            default:
                abort();
                /* NOTREACHED */
        }

#ifdef CLOCK_PPS720
        if ((pp->sloppyclockflag & CLK_FLAG4) && !up->pcl720init) {
                /* Make counter trigger on gate0, count down from 65535. */
                pcl720_load(PCL720_IOB, PCL720_CTR, i8253_oneshot, 65535);
                /*
                 * (These constants are OK since
                 * they represent hardware maximums.)
                 */
                NLOG(NLOG_CLOCKINFO) {
                        msyslog(LOG_NOTICE, "PCL-720 initialized");
                }
                up->pcl720init++;
        }
#endif


}

/*
 * true_poll - called by the transmit procedure
 */
static void
true_poll(
        int unit,
        struct peer *peer
        )
{
        struct true_unit *up;
        struct refclockproc *pp;

        /*
         * You don't need to poll this clock.  It puts out timecodes
         * once per second.  If asked for a timestamp, take note.
         * The next time a timecode comes in, it will be fed back.
         */
        pp = peer->procptr;
        up = (struct true_unit *)pp->unitptr;
        if (up->pollcnt > 0)
            up->pollcnt--;
        else {
                true_doevent(peer, e_Init);
                refclock_report(peer, CEVNT_TIMEOUT);
        }

        /*
         * polled every 64 seconds. Ask true_receive to hand in a
         * timestamp.
         */
        up->polled = 1;
        pp->polls++;
}

#ifdef CLOCK_PPS720
/*
 * true_sample720 - sample the PCL-720
 */
static u_long
true_sample720(void)
{
        unsigned long f;

        /* We wire the PCL-720's 8253.OUT0 to bit 0 of connector 3.
         * If it is not being held low now, we did not get called
         * within 65535us.
         */
        if (inb(pcl720_data_16_23(PCL720_IOB)) & 0x01) {
                NLOG(NLOG_CLOCKINFO) {
                        msyslog(LOG_NOTICE, "PCL-720 out of synch");
                }
                return (0);
        }
        f = (65536 - pcl720_read(PCL720_IOB, PCL720_CTR));
#ifdef PPS720_DEBUG
        msyslog(LOG_DEBUG, "PCL-720: %luus", f);
#endif
        return (f);
}
#endif

#else
int refclock_true_bs;
#endif /* REFCLOCK */