1/* 2 * linux/arch/m68k/kernel/time.c 3 * 4 * Copyright (C) 1991, 1992, 1995 Linus Torvalds 5 * 6 * This file contains the m68k-specific time handling details. 7 * Most of the stuff is located in the machine specific files. 8 * 9 * 1997-09-10 Updated NTP code according to technical memorandum Jan '96 10 * "A Kernel Model for Precision Timekeeping" by Dave Mills 11 */ 12 13#include <linux/errno.h> 14#include <linux/module.h> 15#include <linux/sched.h> 16#include <linux/kernel.h> 17#include <linux/param.h> 18#include <linux/string.h> 19#include <linux/mm.h> 20#include <linux/rtc.h> 21#include <linux/platform_device.h> 22 23#include <asm/machdep.h> 24#include <asm/io.h> 25#include <asm/irq_regs.h> 26 27#include <linux/time.h> 28#include <linux/timex.h> 29#include <linux/profile.h> 30 31static inline int set_rtc_mmss(unsigned long nowtime) 32{ 33 if (mach_set_clock_mmss) 34 return mach_set_clock_mmss (nowtime); 35 return -1; 36} 37 38/* 39 * timer_interrupt() needs to keep up the real-time clock, 40 * as well as call the "do_timer()" routine every clocktick 41 */ 42static irqreturn_t timer_interrupt(int irq, void *dummy) 43{ 44 do_timer(1); 45#ifndef CONFIG_SMP 46 update_process_times(user_mode(get_irq_regs())); 47#endif 48 profile_tick(CPU_PROFILING); 49 50#ifdef CONFIG_HEARTBEAT 51 /* use power LED as a heartbeat instead -- much more useful 52 for debugging -- based on the version for PReP by Cort */ 53 /* acts like an actual heart beat -- ie thump-thump-pause... */ 54 if (mach_heartbeat) { 55 static unsigned cnt = 0, period = 0, dist = 0; 56 57 if (cnt == 0 || cnt == dist) 58 mach_heartbeat( 1 ); 59 else if (cnt == 7 || cnt == dist+7) 60 mach_heartbeat( 0 ); 61 62 if (++cnt > period) { 63 cnt = 0; 64 /* The hyperbolic function below modifies the heartbeat period 65 * length in dependency of the current (5min) load. It goes 66 * through the points f(0)=126, f(1)=86, f(5)=51, 67 * f(inf)->30. */ 68 period = ((672<<FSHIFT)/(5*avenrun[0]+(7<<FSHIFT))) + 30; 69 dist = period / 4; 70 } 71 } 72#endif /* CONFIG_HEARTBEAT */ 73 return IRQ_HANDLED; 74} 75 76void read_persistent_clock(struct timespec *ts) 77{ 78 struct rtc_time time; 79 ts->tv_sec = 0; 80 ts->tv_nsec = 0; 81 82 if (mach_hwclk) { 83 mach_hwclk(0, &time); 84 85 if ((time.tm_year += 1900) < 1970) 86 time.tm_year += 100; 87 ts->tv_sec = mktime(time.tm_year, time.tm_mon, time.tm_mday, 88 time.tm_hour, time.tm_min, time.tm_sec); 89 } 90} 91 92void __init time_init(void) 93{ 94 mach_sched_init(timer_interrupt); 95} 96 97u32 arch_gettimeoffset(void) 98{ 99 return mach_gettimeoffset() * 1000; 100} 101 102static int __init rtc_init(void) 103{ 104 struct platform_device *pdev; 105 106 if (!mach_hwclk) 107 return -ENODEV; 108 109 pdev = platform_device_register_simple("rtc-generic", -1, NULL, 0); 110 if (IS_ERR(pdev)) 111 return PTR_ERR(pdev); 112 113 return 0; 114} 115 116module_init(rtc_init); 117