refclock_true.c

Unix/Linux 网络时间协议版本3 Network Time Protocol Version 3 (NTP) distribution for Unix systems

			true_doevent(peer, e_F51);
			break;
		default:
			true_debug(peer, "got F%02d - ignoring\n", i);
			break;
		}
		return;
	}

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

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

		/*
		 * Adjust the synchronize indicator according to timecode
		 */
		if (sync != ' ' && sync != '.' && sync != '*')
			pp->leap = LEAP_NOTINSYNC;
		else {
			pp->leap = 0;
			pp->lasttime = current_time;
		}

		true_doevent(peer, e_TS);

#ifdef 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 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;
			}
#endif

			pp->usec = true_sample720();
#ifdef 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 ATOM
			/*
			 * Create a true offset for feeding to pps_sample()
			 */
			L_SUB(&off, &pp->lastrec);

			pps_sample(&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);

		/*
		 * 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, NSAMPLES, NSAMPLES)) {
	                true_debug(peer, "Error processing timecodes. \n");
			refclock_report(peer, CEVNT_BADTIME);
			return;
		}
		refclock_receive(peer, &pp->offset, 0, pp->dispersion,
				 &pp->lastrec, &pp->lastrec, pp->leap);

		/*
		 * 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);
	true_debug(peer, "No match to known timecodes. \n");
	return;
}


/*
 * true_send - time to send the clock a signal to cough up a time sample
 */
static void
true_send(peer, cmd)
	struct peer *peer;
	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, len) != len)
			refclock_report(peer, CEVNT_FAULT);
		else
			pp->polls++;
	}
}


/*
 * state machine for initializing and controlling a clock
 */
static void
true_doevent(peer, event)
	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;
		}
		break;
	default:
		abort();
		/* NOTREACHED */
	}

#ifdef 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(unit, peer)
	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 PPS720
/*
 * true_sample720 - sample the PCL-720
 */
static u_long
true_sample720()
{
	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

#endif /*defined(REFCLOCK) && defined(TRUETIME)*/