/*      $NetBSD: refclock_pcf.c,v 1.10 2024/08/18 20:47:18 christos Exp $       */

/*
* 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
NONEMPTY_TRANSLATION_UNIT
#endif /* REFCLOCK */

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