refclock_msfees.c

网络时间协议NTP 源码 版本v4.2.0b 该源码用于linux平台下

/* refclock_ees - clock driver for the EES M201 receiver */

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

#if defined(REFCLOCK) && defined(CLOCK_MSFEES) && defined(PPS)

/* Currently REQUIRES STREAM and PPSCD. CLK and CBREAK modes
 * were removed as the code was overly hairy, they weren't in use
 * (hence probably didn't work).  Still in RCS file at cl.cam.ac.uk
 */

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

#include <ctype.h>
#if defined(HAVE_BSD_TTYS)
#include <sgtty.h>
#endif /* HAVE_BSD_TTYS */
#if defined(HAVE_SYSV_TTYS)
#include <termio.h>
#endif /* HAVE_SYSV_TTYS */
#if defined(HAVE_TERMIOS)
#include <termios.h>
#endif
#if defined(STREAM)
#include <stropts.h>
#endif

#ifdef HAVE_SYS_TERMIOS_H
# include <sys/termios.h>
#endif
#ifdef HAVE_SYS_PPSCLOCK_H
# include <sys/ppsclock.h>
#endif

#include "ntp_stdlib.h"

/*
	fudgefactor	= fudgetime1;
	os_delay	= fudgetime2;
	   offset_fudge	= os_delay + fudgefactor + inherent_delay;
	stratumtouse	= fudgeval1 & 0xf
	debug		= fudgeval2;
	sloppyclockflag	= flags & CLK_FLAG1;
		1	  log smoothing summary when processing sample
		4	  dump the buffer from the clock
		8	  EIOGETKD the last n uS time stamps
	if (flags & CLK_FLAG2 && unitinuse) ees->leaphold = 0;
	ees->dump_vals	= flags & CLK_FLAG3;
	ees->usealldata	= flags & CLK_FLAG4;


	bug->values[0] = (ees->lasttime) ? current_time - ees->lasttime : 0;
	bug->values[1] = (ees->clocklastgood)?current_time-ees->clocklastgood:0;
	bug->values[2] = (u_long)ees->status;
	bug->values[3] = (u_long)ees->lastevent;
	bug->values[4] = (u_long)ees->reason;
	bug->values[5] = (u_long)ees->nsamples;
	bug->values[6] = (u_long)ees->codestate;
	bug->values[7] = (u_long)ees->day;
	bug->values[8] = (u_long)ees->hour;
	bug->values[9] = (u_long)ees->minute;
	bug->values[10] = (u_long)ees->second;
	bug->values[11] = (u_long)ees->tz;
	bug->values[12] = ees->yearstart;
	bug->values[13] = (ees->leaphold > current_time) ?
				ees->leaphold - current_time : 0;
	bug->values[14] = inherent_delay[unit].l_uf;
	bug->values[15] = offset_fudge[unit].l_uf;

	bug->times[0] = ees->reftime;
	bug->times[1] = ees->arrvtime;
	bug->times[2] = ees->lastsampletime;
	bug->times[3] = ees->offset;
	bug->times[4] = ees->lowoffset;
	bug->times[5] = ees->highoffset;
	bug->times[6] = inherent_delay[unit];
	bug->times[8] = os_delay[unit];
	bug->times[7] = fudgefactor[unit];
	bug->times[9] = offset_fudge[unit];
	bug->times[10]= ees->yearstart, 0;
	*/

/* This should support the use of an EES M201 receiver with RS232
 * output (modified to transmit time once per second).
 *
 * For the format of the message sent by the clock, see the EESM_
 * definitions below.
 *
 * It appears to run free for an integral number of minutes, until the error
 * reaches 4mS, at which point it steps at second = 01.
 * It appears that sometimes it steps 4mS (say at 7 min interval),
 * then the next minute it decides that it was an error, so steps back.
 * On the next minute it steps forward again :-(
 * This is typically 16.5uS/S then 3975uS at the 4min re-sync,
 * or 9.5uS/S then 3990.5uS at a 7min re-sync,
 * at which point it may lose the "00" second time stamp.
 * I assume that the most accurate time is just AFTER the re-sync.
 * Hence remember the last cycle interval,
 *
 * Can run in any one of:
 *
 *	PPSCD	PPS signal sets CD which interupts, and grabs the current TOD
 *	(sun)		*in the interupt code*, so as to avoid problems with
 *			the STREAMS scheduling.
 *
 * It appears that it goes 16.5 uS slow each second, then every 4 mins it
 * generates no "00" second tick, and gains 3975 uS. Ho Hum ! (93/2/7)
 */

/* Definitions */
#ifndef	MAXUNITS
#define	MAXUNITS	4	/* maximum number of EES units permitted */
#endif

#ifndef	EES232
#define	EES232	"/dev/ees%d"	/* Device to open to read the data */
#endif

/* Other constant stuff */
#ifndef	EESPRECISION
#define	EESPRECISION	(-10)		/* what the heck - 2**-10 = 1ms */
#endif
#ifndef	EESREFID
#define	EESREFID	"MSF\0"		/* String to identify the clock */
#endif
#ifndef	EESHSREFID
#define	EESHSREFID	(0x7f7f0000 | ((REFCLK_MSF_EES) << 8)) /* Numeric refid */
#endif

/* Description of clock */
#define	EESDESCRIPTION		"EES M201 MSF Receiver"

/* Speed we run the clock port at. If this is changed the UARTDELAY
 * value should be recomputed to suit.
 */
#ifndef	SPEED232
#define	SPEED232	B9600	/* 9600 baud */
#endif

/* What is the inherent delay for this mode of working, i.e. when is the
 * data time stamped.
 */
#define	SAFETY_SHIFT	10	/* Split the shift to avoid overflow */
#define	BITS_TO_L_FP(bits, baud) \
(((((bits)*2 +1) << (FRACTION_PREC-SAFETY_SHIFT)) / (2*baud)) << SAFETY_SHIFT)
#define	INH_DELAY_CBREAK	BITS_TO_L_FP(119, 9600)
#define	INH_DELAY_PPS		BITS_TO_L_FP(  0, 9600)

#ifndef	STREAM_PP1
#define	STREAM_PP1	"ppsclocd\0<-- patch space for module name1 -->"
#endif
#ifndef	STREAM_PP2
#define	STREAM_PP2	"ppsclock\0<-- patch space for module name2 -->"
#endif

     /* Offsets of the bytes of the serial line code.  The clock gives
 * local time with a GMT/BST indication. The EESM_ definitions
 * give offsets into ees->lastcode.
 */
#define EESM_CSEC	 0	/* centiseconds - always zero in our clock  */
#define EESM_SEC	 1	/* seconds in BCD			    */
#define EESM_MIN	 2	/* minutes in BCD			    */
#define EESM_HOUR	 3	/* hours in BCD				    */
#define EESM_DAYWK	 4	/* day of week (Sun = 0 etc)		    */
#define EESM_DAY	 5	/* day of month in BCD			    */
#define EESM_MON	 6	/* month in BCD				    */
#define EESM_YEAR	 7	/* year MOD 100 in BCD			    */
#define EESM_LEAP	 8	/* 0x0f if leap year, otherwise zero        */
#define EESM_BST	 9	/* 0x03 if BST, 0x00 if GMT		    */
#define EESM_MSFOK	10	/* 0x3f if radio good, otherwise zero	    */
				/* followed by a frame alignment byte (0xff) /
				/  which is not put into the lastcode buffer*/

/* Length of the serial time code, in characters.  The first length
 * is less the frame alignment byte.
 */
#define	LENEESPRT	(EESM_MSFOK+1)
#define	LENEESCODE	(LENEESPRT+1)

     /* Code state. */
#define	EESCS_WAIT	0       /* waiting for start of timecode */
#define	EESCS_GOTSOME	1	/* have an incomplete time code buffered */

     /* Default fudge factor and character to receive */
#define	DEFFUDGETIME	0	/* Default user supplied fudge factor */
#ifndef	DEFOSTIME
#define	DEFOSTIME	0	/* Default OS delay -- passed by Make ? */
#endif
#define	DEFINHTIME	INH_DELAY_PPS /* inherent delay due to sample point*/

     /* Limits on things.  Reduce the number of samples to SAMPLEREDUCE by median
 * elimination.  If we're running with an accurate clock, chose the BESTSAMPLE
 * as the estimated offset, otherwise average the remainder.
 */
#define	FULLSHIFT	6			/* NCODES root 2 */
#define NCODES		(1<< FULLSHIFT)		/* 64 */
#define	REDUCESHIFT	(FULLSHIFT -1)		/* SAMPLEREDUCE root 2 */

     /* Towards the high ( Why ?) end of half */
#define	BESTSAMPLE	((samplereduce * 3) /4)	/* 24 */

     /* Leap hold time.  After a leap second the clock will no longer be
 * reliable until it resynchronizes.  Hope 40 minutes is enough. */
#define	EESLEAPHOLD	(40 * 60)

#define	EES_STEP_F	(1 << 24) /* the receiver steps in units of about 4ms */
#define	EES_STEP_F_GRACE (EES_STEP_F/8) /*Allow for slop of 1/8 which is .5ms*/
#define	EES_STEP_NOTE	(1 << 21)/* Log any unexpected jumps, say .5 ms .... */
#define	EES_STEP_NOTES	50	/* Only do a limited number */
#define	MAX_STEP	16	/* Max number of steps to remember */

     /* debug is a bit mask of debugging that is wanted */
#define	DB_SYSLOG_SMPLI		0x0001
#define	DB_SYSLOG_SMPLE		0x0002
#define	DB_SYSLOG_SMTHI		0x0004
#define	DB_SYSLOG_NSMTHE	0x0008
#define	DB_SYSLOG_NSMTHI	0x0010
#define	DB_SYSLOG_SMTHE		0x0020
#define	DB_PRINT_EV		0x0040
#define	DB_PRINT_CDT		0x0080
#define	DB_PRINT_CDTC		0x0100
#define	DB_SYSLOG_KEEPD		0x0800
#define	DB_SYSLOG_KEEPE		0x1000
#define	DB_LOG_DELTAS		0x2000
#define	DB_PRINT_DELTAS		0x4000
#define	DB_LOG_AWAITMORE	0x8000
#define	DB_LOG_SAMPLES		0x10000
#define	DB_NO_PPS		0x20000
#define	DB_INC_PPS		0x40000
#define	DB_DUMP_DELTAS		0x80000

     struct eesunit {			/* EES unit control structure. */
	     struct peer *peer;		/* associated peer structure */
	     struct refclockio io;		/* given to the I/O handler */
	     l_fp	reftime;		/* reference time */
	     l_fp	lastsampletime;		/* time as in txt from last EES msg */
	     l_fp	arrvtime;		/* Time at which pkt arrived */
	     l_fp	codeoffsets[NCODES];	/* the time of arrival of 232 codes */
	     l_fp	offset;			/* chosen offset        (for clkbug) */
	     l_fp	lowoffset;		/* lowest sample offset (for clkbug) */
	     l_fp	highoffset;		/* highest   "     "    (for clkbug) */
	     char	lastcode[LENEESCODE+6];	/* last time code we received */
	     u_long	lasttime;		/* last time clock heard from */
	     u_long	clocklastgood;		/* last time good radio seen */
	     u_char	lencode;		/* length of code in buffer */
	     u_char	nsamples;		/* number of samples we've collected */
	     u_char	codestate;		/* state of 232 code reception */
	     u_char	unit;			/* unit number for this guy */
	     u_char	status;			/* clock status */
	     u_char	lastevent;		/* last clock event */
	     u_char	reason;			/* reason for last abort */
	     u_char	hour;			/* hour of day */
	     u_char	minute;			/* minute of hour */
	     u_char	second;			/* seconds of minute */
	     char	tz;			/* timezone from clock */
	     u_char	ttytype;		/* method used */
	     u_char	dump_vals;		/* Should clock values be dumped */
	     u_char	usealldata;		/* Use ALL samples */
	     u_short	day;			/* day of year from last code */
	     u_long	yearstart;		/* start of current year */
	     u_long	leaphold;		/* time of leap hold expiry */
	     u_long	badformat;		/* number of bad format codes */
	     u_long	baddata;		/* number of invalid time codes */
	     u_long	timestarted;		/* time we started this */
	     long	last_pps_no;		/* The serial # of the last PPS */
	     char	fix_pending;		/* Is a "sync to time" pending ? */
	     /* Fine tuning - compensate for 4 mS ramping .... */
	     l_fp	last_l;			/* last time stamp */
	     u_char	last_steps[MAX_STEP];	/* Most recent n steps */
	     int	best_av_step;		/* Best guess at average step */
	     char	best_av_step_count;	/* # of steps over used above */
	     char	this_step;		/* Current pos in buffer */
	     int	last_step_late;		/* How late the last step was (0-59) */
	     long	jump_fsecs;		/* # of fractions of a sec last jump */
	     u_long	last_step;		/* time of last step */
	     int	last_step_secs;		/* Number of seconds in last step */
	     int	using_ramp;		/* 1 -> noemal, -1 -> over stepped */
     };
#define	last_sec	last_l.l_ui
#define	last_sfsec	last_l.l_f
#define	this_uisec	((ees->arrvtime).l_ui)
#define	this_sfsec	((ees->arrvtime).l_f)
#define	msec(x)		((x) / (1<<22))
#define	LAST_STEPS	(sizeof ees->last_steps / sizeof ees->last_steps[0])
#define	subms(x)	((((((x < 0) ? (-(x)) : (x)) % (1<<22))/2) * 625) / (1<<(22 -5)))

/* Bitmask for what methods to try to use -- currently only PPS enabled */
#define	T_CBREAK	1
#define	T_PPS		8
/* macros to test above */
#define	is_cbreak(x)	((x)->ttytype & T_CBREAK)
#define	is_pps(x)	((x)->ttytype & T_PPS)
#define	is_any(x)	((x)->ttytype)

#define	CODEREASON	20	/* reason codes */

/* Data space for the unit structures.  Note that we allocate these on
 * the fly, but never give them back. */
static struct eesunit *eesunits[MAXUNITS];
static u_char unitinuse[MAXUNITS];

/* Keep the fudge factors separately so they can be set even
 * when no clock is configured. */
static l_fp inherent_delay[MAXUNITS];		/* when time stamp is taken */
static l_fp fudgefactor[MAXUNITS];		/* fudgetime1 */
static l_fp os_delay[MAXUNITS];			/* fudgetime2 */
static l_fp offset_fudge[MAXUNITS];		/* Sum of above */
static u_char stratumtouse[MAXUNITS];
static u_char sloppyclockflag[MAXUNITS];

static int deltas[60];

static l_fp acceptable_slop; /* = { 0, 1 << (FRACTION_PREC -2) }; */
static l_fp onesec; /* = { 1, 0 }; */

#ifndef	DUMP_BUF_SIZE	/* Size of buffer to be used by dump_buf */
#define	DUMP_BUF_SIZE	10112
#endif

/* ees_reset - reset the count back to zero */
#define	ees_reset(ees) (ees)->nsamples = 0; \
(ees)->codestate = EESCS_WAIT

/* ees_event - record and report an event */
#define	ees_event(ees, evcode) if ((ees)->status != (u_char)(evcode)) \
ees_report_event((ees), (evcode))

     /* Find the precision of the system clock by reading it */
#define	USECS	1000000
#define	MINSTEP	5	/* some systems increment uS on each call */
#define	MAXLOOPS (USECS/9)

/*
 * Function prototypes
 */

static	int	msfees_start	P((int unit, struct peer *peer));
static	void	msfees_shutdown	P((int unit, struct peer *peer));
static	void	msfees_poll	P((int unit, struct peer *peer));
static	void	msfees_init	P((void));
static	void	dump_buf	P((l_fp *coffs, int from, int to, char *text));
static	void	ees_report_event P((struct eesunit *ees, int code));
static	void	ees_receive	P((struct recvbuf *rbufp));
static	void	ees_process	P((struct eesunit *ees));
#ifdef QSORT_USES_VOID_P
static	int	offcompare	P((const void *va, const void *vb));
#else
static	int	offcompare	P((const l_fp *a, const l_fp *b));
#endif /* QSORT_USES_VOID_P */


/*
 * Transfer vector
 */
struct	refclock refclock_msfees = {
	msfees_start,		/* start up driver */
	msfees_shutdown,	/* shut down driver */
	msfees_poll,		/* transmit poll message */
	noentry,		/* not used */
	msfees_init,		/* initialize driver */