http://www.ousob.com --- Legacy Redefined OuSob - File: /wwwroot/clipx/usr/include/linux/timex.h

/***************************************************************************** * * * 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/config.h> #include <linux/compiler.h> #include <linux/time.h> #include <asm/param.h> #include <asm/timex.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_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 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 FINENSEC define represents 1 nsec 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. * * FINENSEC is 1 ns 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 FINENSEC (1L << (SHIFT_SCALE - 10)) /* ~1 ns in phase units */ #define MAXPHASE 512000L /* max phase error (us) */ #define MAXFREQ (512L << 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) */ /* * 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 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_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_freq; /* frequency offset (scaled ppm) */ extern long time_reftime; /* time at last adjustment (s) */ extern long time_adjust; /* The amount of adjtime left */ extern long time_next_adjust; /* Value for time_adjust at next tick */ /* 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 */ /** * ntp_clear - Clears the NTP state variables * * Must be called while holding a write on the xtime_lock */ static inline void ntp_clear(void) { time_adjust = 0; /* stop active adjtime() */ time_status |= STA_UNSYNC; time_maxerror = NTP_PHASE_LIMIT; time_esterror = NTP_PHASE_LIMIT; } /** * 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; \ }) #ifdef CONFIG_TIME_INTERPOLATION #define TIME_SOURCE_CPU 0 #define TIME_SOURCE_MMIO64 1 #define TIME_SOURCE_MMIO32 2 #define TIME_SOURCE_FUNCTION 3 /* For proper operations time_interpolator clocks must run slightly slower * than the standard clock since the interpolator may only correct by having * time jump forward during a tick. A slower clock is usually a side effect * of the integer divide of the nanoseconds in a second by the frequency. * The accuracy of the division can be increased by specifying a shift. * However, this may cause the clock not to be slow enough. * The interpolator will self-tune the clock by slowing down if no * resets occur or speeding up if the time jumps per analysis cycle * become too high. * * Setting jitter compensates for a fluctuating timesource by comparing * to the last value read from the timesource to insure that an earlier value * is not returned by a later call. The price to pay * for the compensation is that the timer routines are not as scalable anymore. */ struct time_interpolator { u16 source; /* time source flags */ u8 shift; /* increases accuracy of multiply by shifting. */ /* Note that bits may be lost if shift is set too high */ u8 jitter; /* if set compensate for fluctuations */ u32 nsec_per_cyc; /* set by register_time_interpolator() */ void *addr; /* address of counter or function */ u64 mask; /* mask the valid bits of the counter */ unsigned long offset; /* nsec offset at last update of interpolator */ u64 last_counter; /* counter value in units of the counter at last update */ u64 last_cycle; /* Last timer value if TIME_SOURCE_JITTER is set */ u64 frequency; /* frequency in counts/second */ long drift; /* drift in parts-per-million (or -1) */ unsigned long skips; /* skips forward */ unsigned long ns_skipped; /* nanoseconds skipped */ struct time_interpolator *next; }; extern void register_time_interpolator(struct time_interpolator *); extern void unregister_time_interpolator(struct time_interpolator *); extern void time_interpolator_reset(void); extern unsigned long time_interpolator_get_offset(void); #else /* !CONFIG_TIME_INTERPOLATION */ static inline void time_interpolator_reset(void) { } #endif /* !CONFIG_TIME_INTERPOLATION */ /* Returns how long ticks are at present, in ns / 2^(SHIFT_SCALE-10). */ extern u64 current_tick_length(void); #endif /* KERNEL */ #endif /* LINUX_TIMEX_H */