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/*****************************************************************************

 *                                                                           *

 * Copyright (c) David L. Mills 1993                                         *

 *                                                                           *

 * Permission to use, copy, modify, and distribute this software and its     *

 * documentation for any purpose and without fee is hereby granted, provided *

 * that the above copyright notice appears in all copies and that both the   *

 * copyright notice and this permission notice appear in supporting          *

 * documentation, and that the name University of Delaware not be used in    *

 * advertising or publicity pertaining to distribution of the software       *

 * without specific, written prior permission.  The University of Delaware   *

 * makes no representations about the suitability this software for any      *

 * purpose.  It is provided "as is" without express or implied warranty.     *

 *                                                                           *

 *****************************************************************************/

/*

 * Modification history timex.h

 *

 * 26 Sep 94    David L. Mills

 *      Added defines for hybrid phase/frequency-lock loop.

 *

 * 19 Mar 94    David L. Mills

 *      Moved defines from kernel routines to header file and added new

 *      defines for PPS phase-lock loop.

 *

 * 20 Feb 94    David L. Mills

 *      Revised status codes and structures for external clock and PPS

 *      signal discipline.

 *

 * 28 Nov 93    David L. Mills

 *      Adjusted parameters to improve stability and increase poll

 *      interval.

 *

 * 17 Sep 93    David L. Mills

 *      Created file $NTP/include/sys/timex.h

 * 07 Oct 93    Torsten Duwe

 *      Derived linux/timex.h

 * 1995-08-13    Torsten Duwe

 *      kernel PLL updated to 1994-12-13 specs (rfc-1589)

 * 1997-08-30    Ulrich Windl

 *      Added new constant NTP_PHASE_LIMIT. Corrected MAXFREQ.

 */

#ifndef _LINUX_TIMEX_H

#define _LINUX_TIMEX_H

/*

 * The following defines establish the engineering parameters of the PLL

 * model. The HZ variable establishes the timer interrupt frequency, 100 Hz

 * for the SunOS kernel, 256 Hz for the Ultrix kernel and 1024 Hz for the

 * OSF/1 kernel. The SHIFT_HZ define expresses the same value as the

 * nearest power of two in order to avoid hardware multiply operations.

 */

#ifdef __alpha__

# define SHIFT_HZ 10            /* log2(HZ) */

#else

# define SHIFT_HZ 7             /* log2(HZ) */

#endif

/*

 * SHIFT_KG and SHIFT_KF establish the damping of the PLL and are chosen

 * for a slightly underdamped convergence characteristic. SHIFT_KH

 * establishes the damping of the FLL and is chosen by wisdom and black

 * art.

 *

 * MAXTC establishes the maximum time constant of the PLL. With the

 * SHIFT_KG and SHIFT_KF values given and a time constant range from

 * zero to MAXTC, the PLL will converge in 15 minutes to 16 hours,

 * respectively.

 */

#define SHIFT_KG 6              /* phase factor (shift) */

#define SHIFT_KF 16             /* PLL frequency factor (shift) */

#define SHIFT_KH 2              /* FLL frequency factor (shift) */

#define MAXTC 6                 /* maximum time constant (shift) */

/*

 * The SHIFT_SCALE define establishes the decimal point of the time_phase

 * variable which serves as a an extension to the low-order bits of the

 * system clock variable. The SHIFT_UPDATE define establishes the decimal

 * point of the time_offset variable which represents the current offset

 * with respect to standard time. The FINEUSEC define represents 1 usec in

 * scaled units.

 *

 * SHIFT_USEC defines the scaling (shift) of the time_freq and

 * time_tolerance variables, which represent the current frequency

 * offset and maximum frequency tolerance.

 *

 * FINEUSEC is 1 us in SHIFT_UPDATE units of the time_phase variable.

 */

#define SHIFT_SCALE 22          /* phase scale (shift) */

#define SHIFT_UPDATE (SHIFT_KG + MAXTC) /* time offset scale (shift) */

#define SHIFT_USEC 16           /* frequency offset scale (shift) */

#define FINEUSEC (1L << SHIFT_SCALE) /* 1 us in phase units */

#define MAXPHASE 512000L        /* max phase error (us) */

#define MAXFREQ (200L << SHIFT_USEC)  /* max frequency error (ppm) */

#define MAXTIME (200L << PPS_AVG) /* max PPS error (jitter) (200 us) */

#define MINSEC 16L              /* min interval between updates (s) */

#define MAXSEC 1200L            /* max interval between updates (s) */

#define NTP_PHASE_LIMIT (MAXPHASE << 5) /* beyond max. dispersion */

/*

 * The following defines are used only if a pulse-per-second (PPS)

 * signal is available and connected via a modem control lead, such as

 * produced by the optional ppsclock feature incorporated in the Sun

 * asynch driver. They establish the design parameters of the frequency-

 * lock loop used to discipline the CPU clock oscillator to the PPS

 * signal.

 *

 * PPS_AVG is the averaging factor for the frequency loop, as well as

 * the time and frequency dispersion.

 *

 * PPS_SHIFT and PPS_SHIFTMAX specify the minimum and maximum

 * calibration intervals, respectively, in seconds as a power of two.

 *

 * PPS_VALID is the maximum interval before the PPS signal is considered

 * invalid and protocol updates used directly instead.

 *

 * MAXGLITCH is the maximum interval before a time offset of more than

 * MAXTIME is believed.

 */

#define PPS_AVG 2               /* pps averaging constant (shift) */

#define PPS_SHIFT 2             /* min interval duration (s) (shift) */

#define PPS_SHIFTMAX 8          /* max interval duration (s) (shift) */

#define PPS_VALID 120           /* pps signal watchdog max (s) */

#define MAXGLITCH 30            /* pps signal glitch max (s) */

#ifndef __alpha__

/*

 * This definitively is wrong for the Alpha and none of the

 * kernel code seems to reference this anymore.

 */

#define CLOCK_TICK_RATE 1193180 /* Underlying HZ */

#define CLOCK_TICK_FACTOR       20      /* Factor of both 1000000 and CLOCK_TICK_RATE */

#define LATCH  ((CLOCK_TICK_RATE + HZ/2) / HZ)  /* For divider */

#define FINETUNE ((((((long)LATCH * HZ - CLOCK_TICK_RATE) << SHIFT_HZ) * \

        (1000000/CLOCK_TICK_FACTOR) / (CLOCK_TICK_RATE/CLOCK_TICK_FACTOR)) \

                << (SHIFT_SCALE-SHIFT_HZ)) / HZ)

#endif /* !__alpha__ */

/*

 * syscall interface - used (mainly by NTP daemon)

 * to discipline kernel clock oscillator

 */

struct timex {

        unsigned int modes;     /* mode selector */

        long offset;            /* time offset (usec) */

        long freq;              /* frequency offset (scaled ppm) */

        long maxerror;          /* maximum error (usec) */

        long esterror;          /* estimated error (usec) */

        int status;             /* clock command/status */

        long constant;          /* pll time constant */

        long precision;         /* clock precision (usec) (read only) */

        long tolerance;         /* clock frequency tolerance (ppm)

                                 * (read only)

                                 */

        struct timeval time;    /* (read only) */

        long tick;              /* (modified) usecs between clock ticks */

        long ppsfreq;           /* pps frequency (scaled ppm) (ro) */

        long jitter;            /* pps jitter (us) (ro) */

        int shift;              /* interval duration (s) (shift) (ro) */

        long stabil;            /* pps stability (scaled ppm) (ro) */

        long jitcnt;            /* jitter limit exceeded (ro) */

        long calcnt;            /* calibration intervals (ro) */

        long errcnt;            /* calibration errors (ro) */

        long stbcnt;            /* stability limit exceeded (ro) */

        int  :32; int  :32; int  :32; int  :32;

        int  :32; int  :32; int  :32; int  :32;

        int  :32; int  :32; int  :32; int  :32;

};

/*

 * Mode codes (timex.mode)

 */

#define ADJ_OFFSET              0x0001  /* time offset */

#define ADJ_FREQUENCY           0x0002  /* frequency offset */

#define ADJ_MAXERROR            0x0004  /* maximum time error */

#define ADJ_ESTERROR            0x0008  /* estimated time error */

#define ADJ_STATUS              0x0010  /* clock status */

#define ADJ_TIMECONST           0x0020  /* pll time constant */

#define ADJ_TICK                0x4000  /* tick value */

#define ADJ_OFFSET_SINGLESHOT   0x8001  /* old-fashioned adjtime */

/* xntp 3.4 compatibility names */

#define MOD_OFFSET      ADJ_OFFSET

#define MOD_FREQUENCY   ADJ_FREQUENCY

#define MOD_MAXERROR    ADJ_MAXERROR

#define MOD_ESTERROR    ADJ_ESTERROR

#define MOD_STATUS      ADJ_STATUS

#define MOD_TIMECONST   ADJ_TIMECONST

#define MOD_CLKB        ADJ_TICK

#define MOD_CLKA        ADJ_OFFSET_SINGLESHOT /* 0x8000 in original */

/*

 * Status codes (timex.status)

 */

#define STA_PLL         0x0001  /* enable PLL updates (rw) */

#define STA_PPSFREQ     0x0002  /* enable PPS freq discipline (rw) */

#define STA_PPSTIME     0x0004  /* enable PPS time discipline (rw) */

#define STA_FLL         0x0008  /* select frequency-lock mode (rw) */

#define STA_INS         0x0010  /* insert leap (rw) */

#define STA_DEL         0x0020  /* delete leap (rw) */

#define STA_UNSYNC      0x0040  /* clock unsynchronized (rw) */

#define STA_FREQHOLD    0x0080  /* hold frequency (rw) */

#define STA_PPSSIGNAL   0x0100  /* PPS signal present (ro) */

#define STA_PPSJITTER   0x0200  /* PPS signal jitter exceeded (ro) */

#define STA_PPSWANDER   0x0400  /* PPS signal wander exceeded (ro) */

#define STA_PPSERROR    0x0800  /* PPS signal calibration error (ro) */

#define STA_CLOCKERR    0x1000  /* clock hardware fault (ro) */

#define STA_RONLY (STA_PPSSIGNAL | STA_PPSJITTER | STA_PPSWANDER | \

    STA_PPSERROR | STA_CLOCKERR) /* read-only bits */

/*

 * Clock states (time_state)

 */

#define TIME_OK         0        /* clock synchronized, no leap second */

#define TIME_INS        1       /* insert leap second */

#define TIME_DEL        2       /* delete leap second */

#define TIME_OOP        3       /* leap second in progress */

#define TIME_WAIT       4       /* leap second has occurred */

#define TIME_ERROR      5       /* clock not synchronized */

#define TIME_BAD        TIME_ERROR /* bw compat */

#ifdef __KERNEL__

/*

 * kernel variables

 * Note: maximum error = NTP synch distance = dispersion + delay / 2;

 * estimated error = NTP dispersion.

 */

extern long tick;                      /* timer interrupt period */

extern int tickadj;                     /* amount of adjustment per tick */

/*

 * phase-lock loop variables

 */

extern int time_state;          /* clock status */

extern int time_status;         /* clock synchronization status bits */

extern long time_offset;        /* time adjustment (us) */

extern long time_constant;      /* pll time constant */

extern long time_tolerance;     /* frequency tolerance (ppm) */

extern long time_precision;     /* clock precision (us) */

extern long time_maxerror;      /* maximum error */

extern long time_esterror;      /* estimated error */

extern long time_phase;         /* phase offset (scaled us) */

extern long time_freq;          /* frequency offset (scaled ppm) */

extern long time_adj;           /* tick adjust (scaled 1 / HZ) */

extern long time_reftime;       /* time at last adjustment (s) */

extern long time_adjust;        /* The amount of adjtime left */

/* interface variables pps->timer interrupt */

extern long pps_offset;         /* pps time offset (us) */

extern long pps_jitter;         /* time dispersion (jitter) (us) */

extern long pps_freq;           /* frequency offset (scaled ppm) */

extern long pps_stabil;         /* frequency dispersion (scaled ppm) */

extern long pps_valid;          /* pps signal watchdog counter */

/* interface variables pps->adjtimex */

extern int pps_shift;           /* interval duration (s) (shift) */

extern long pps_jitcnt;         /* jitter limit exceeded */

extern long pps_calcnt;         /* calibration intervals */

extern long pps_errcnt;         /* calibration errors */

extern long pps_stbcnt;         /* stability limit exceeded */

#endif /* KERNEL */

#endif /* LINUX_TIMEX_H */