3  hD0 *l4( (  fB- q9_I|+/***************************************************************************** * * * 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 #define ADJ_ADJTIME 0x8000 /* switch between adjtime/adjtimex modes */ #define ADJ_OFFSET_SINGLESHOT 0x0001 /* old-fashioned adjtime */ #define ADJ_OFFSET_READONLY 0x2000 /* read-only adjtime */ #include #include #include unsigned long random_get_entropy_fallback(void); #include #ifndef random_get_entropy /* * The random_get_entropy() function is used by the /dev/random driver * in order to extract entropy via the relative unpredictability of * when an interrupt takes places versus a high speed, fine-grained * timing source or cycle counter. Since it will be occurred on every * single interrupt, it must have a very low cost/overhead. * * By default we use get_cycles() for this purpose, but individual * architectures may override this in their asm/timex.h header file. * If a given arch does not have get_cycles(), then we fallback to * using random_get_entropy_fallback(). */ #ifdef get_cycles #define random_get_entropy() ((unsigned long)get_cycles()) #else #define random_get_entropy() random_get_entropy_fallback() #endif #endif /* * SHIFT_PLL is used as a dampening factor to define how much we * adjust the frequency correction for a given offset in PLL mode. * It also used in dampening the offset correction, to define how * much of the current value in time_offset we correct for each * second. Changing this value changes the stiffness of the ntp * adjustment code. A lower value makes it more flexible, reducing * NTP convergence time. A higher value makes it stiffer, increasing * convergence time, but making the clock more stable. * * In David Mi