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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

 *

 * 29 Dec 97    Russell King

 *      Moved CLOCK_TICK_RATE, CLOCK_TICK_FACTOR and FINETUNE to asm/timex.h

 *      for ARM machines

 *

 *  9 Jan 97    Adrian Sun

 *      Shifted LATCH define to allow access to alpha machines.

 *

 * 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

 * 2004-08-12    Christoph Lameter

 *      Reworked time interpolation logic

 */

#ifndef _LINUX_TIMEX_H

#define _LINUX_TIMEX_H

#include <linux/compiler.h>

#include <linux/time.h>

#include <asm/param.h>

/*

 * 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_PLL       4       /* PLL frequency factor (shift) */

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

#define MAXTC           10      /* maximum time constant (shift) */

/*

 * The SHIFT_UPDATE define establishes the decimal point of the

 * time_offset variable which represents the current offset with

 * respect to standard time.

 *

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

 * time_tolerance variables, which represent the current frequency

 * offset and maximum frequency tolerance.

 */

#define SHIFT_UPDATE (SHIFT_HZ + 1) /* time offset scale (shift) */

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

#define SHIFT_NSEC 12           /* kernel frequency offset scale */

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

#define MAXFREQ (512L << SHIFT_USEC)  /* max frequency error (ppm) */

#define MAXFREQ_NSEC (512000L << SHIFT_NSEC) /* max frequency error (ppb) */

#define MINSEC 256              /* min interval between updates (s) */

#define MAXSEC 2048             /* max interval between updates (s) */

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

/*

 * 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 */

#define ADJ_OFFSET_SS_READ      0xa001  /* read-only 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__

#include <asm/timex.h>

/*

 * kernel variables

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

 * estimated error = NTP dispersion.

 */

extern unsigned long tick_usec;         /* USER_HZ period (usec) */

extern unsigned long tick_nsec;         /* ACTHZ          period (nsec) */

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

/*

 * phase-lock loop variables

 */

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

extern long time_maxerror;      /* maximum error */

extern long time_esterror;      /* estimated error */

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

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

extern void ntp_clear(void);

/**

 * ntp_synced - Returns 1 if the NTP status is not UNSYNC

 *

 */

static inline int ntp_synced(void)

{

        return !(time_status & STA_UNSYNC);

}

/* Required to safely shift negative values */

#define shift_right(x, s) ({    \

        __typeof__(x) __x = (x);        \

        __typeof__(s) __s = (s);        \

        __x < 0 ? -(-__x >> __s) : __x >> __s;   \

})

#define TICK_LENGTH_SHIFT       32

#ifdef CONFIG_NO_HZ

#define NTP_INTERVAL_FREQ  (2)

#else

#define NTP_INTERVAL_FREQ  (HZ)

#endif

#define NTP_INTERVAL_LENGTH (NSEC_PER_SEC/NTP_INTERVAL_FREQ)

/* Returns how long ticks are at present, in ns / 2^(SHIFT_SCALE-10). */

extern u64 current_tick_length(void);

extern void second_overflow(void);

extern void update_ntp_one_tick(void);

extern int do_adjtimex(struct timex *);

/* Don't use! Compatibility define for existing users. */

#define tickadj (500/HZ ? : 1)

#endif /* KERNEL */

#endif /* LINUX_TIMEX_H */