refclock_true.c

网络时间协议NTP 源码 版本v4.2.0b 该源码用于linux平台下

	}

	/*
	 * 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 */