/* * linux/arch/v850/kernel/time.c -- Arch-dependent timer functions * * Copyright (C) 1991, 1992, 1995, 2001, 2002 Linus Torvalds * * This file contains the v850-specific time handling details. * Most of the stuff is located in the machine specific files. * * 1997-09-10 Updated NTP code according to technical memorandum Jan '96 * "A Kernel Model for Precision Timekeeping" by Dave Mills */ #include <linux/errno.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/param.h> #include <linux/string.h> #include <linux/mm.h> #include <linux/interrupt.h> #include <linux/time.h> #include <linux/timex.h> #include <linux/profile.h> #include <asm/io.h> #include "mach.h" #define TICK_SIZE (tick_nsec / 1000) /* * timer_interrupt() needs to keep up the real-time clock, * as well as call the "do_timer()" routine every clocktick */ static irqreturn_t timer_interrupt (int irq, void *dummy, struct pt_regs *regs) { #if 0 /* last time the cmos clock got updated */ static long last_rtc_update=0; #endif /* may need to kick the hardware timer */ if (mach_tick) mach_tick (); do_timer (1); #ifndef CONFIG_SMP update_process_times(user_mode(regs)); #endif profile_tick(CPU_PROFILING, regs); #if 0 /* * If we have an externally synchronized Linux clock, then update * CMOS clock accordingly every ~11 minutes. Set_rtc_mmss() has to be * called as close as possible to 500 ms before the new second starts. */ if (ntp_synced() && xtime.tv_sec > last_rtc_update + 660 && (xtime.tv_nsec / 1000) >= 500000 - ((unsigned) TICK_SIZE) / 2 && (xtime.tv_nsec / 1000) <= 500000 + ((unsigned) TICK_SIZE) / 2) { if (set_rtc_mmss (xtime.tv_sec) == 0) last_rtc_update = xtime.tv_sec; else last_rtc_update = xtime.tv_sec - 600; /* do it again in 60 s */ } #ifdef CONFIG_HEARTBEAT /* use power LED as a heartbeat instead -- much more useful for debugging -- based on the version for PReP by Cort */ /* acts like an actual heart beat -- ie thump-thump-pause... */ if (mach_heartbeat) { static unsigned cnt = 0, period = 0, dist = 0; if (cnt == 0 || cnt == dist) mach_heartbeat ( 1 ); else if (cnt == 7 || cnt == dist+7) mach_heartbeat ( 0 ); if (++cnt > period) { cnt = 0; /* The hyperbolic function below modifies the heartbeat period * length in dependency of the current (5min) load. It goes * through the points f(0)=126, f(1)=86, f(5)=51, * f(inf)->30. */ period = ((672<<FSHIFT)/(5*avenrun[0]+(7<<FSHIFT))) + 30; dist = period / 4; } } #endif /* CONFIG_HEARTBEAT */ #endif /* 0 */ return IRQ_HANDLED; } static int timer_dev_id; static struct irqaction timer_irqaction = { timer_interrupt, IRQF_DISABLED, CPU_MASK_NONE, "timer", &timer_dev_id, NULL }; void time_init (void) { mach_gettimeofday (&xtime); mach_sched_init (&timer_irqaction); }