| Greg Ungerer | fa7f9e7 | 2012-01-23 16:23:33 +1000 | [diff] [blame] | 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 | |
| Greg Ungerer | fa7f9e7 | 2012-01-23 16:23:33 +1000 | [diff] [blame] | 31 | /* |
| 32 | * timer_interrupt() needs to keep up the real-time clock, |
| 33 | * as well as call the "xtime_update()" routine every clocktick |
| 34 | */ |
| 35 | static irqreturn_t timer_interrupt(int irq, void *dummy) |
| 36 | { |
| 37 | xtime_update(1); |
| 38 | update_process_times(user_mode(get_irq_regs())); |
| 39 | profile_tick(CPU_PROFILING); |
| 40 | |
| 41 | #ifdef CONFIG_HEARTBEAT |
| 42 | /* use power LED as a heartbeat instead -- much more useful |
| 43 | for debugging -- based on the version for PReP by Cort */ |
| 44 | /* acts like an actual heart beat -- ie thump-thump-pause... */ |
| 45 | if (mach_heartbeat) { |
| 46 | static unsigned cnt = 0, period = 0, dist = 0; |
| 47 | |
| 48 | if (cnt == 0 || cnt == dist) |
| 49 | mach_heartbeat( 1 ); |
| 50 | else if (cnt == 7 || cnt == dist+7) |
| 51 | mach_heartbeat( 0 ); |
| 52 | |
| 53 | if (++cnt > period) { |
| 54 | cnt = 0; |
| 55 | /* The hyperbolic function below modifies the heartbeat period |
| 56 | * length in dependency of the current (5min) load. It goes |
| 57 | * through the points f(0)=126, f(1)=86, f(5)=51, |
| 58 | * f(inf)->30. */ |
| 59 | period = ((672<<FSHIFT)/(5*avenrun[0]+(7<<FSHIFT))) + 30; |
| 60 | dist = period / 4; |
| 61 | } |
| 62 | } |
| 63 | #endif /* CONFIG_HEARTBEAT */ |
| 64 | return IRQ_HANDLED; |
| 65 | } |
| 66 | |
| 67 | void read_persistent_clock(struct timespec *ts) |
| 68 | { |
| 69 | struct rtc_time time; |
| 70 | ts->tv_sec = 0; |
| 71 | ts->tv_nsec = 0; |
| 72 | |
| 73 | if (mach_hwclk) { |
| 74 | mach_hwclk(0, &time); |
| 75 | |
| 76 | if ((time.tm_year += 1900) < 1970) |
| 77 | time.tm_year += 100; |
| 78 | ts->tv_sec = mktime(time.tm_year, time.tm_mon, time.tm_mday, |
| 79 | time.tm_hour, time.tm_min, time.tm_sec); |
| 80 | } |
| 81 | } |
| 82 | |
| 83 | void __init time_init(void) |
| 84 | { |
| 85 | mach_sched_init(timer_interrupt); |
| 86 | } |
| 87 | |
| 88 | #ifdef CONFIG_M68KCLASSIC |
| 89 | |
| 90 | u32 arch_gettimeoffset(void) |
| 91 | { |
| 92 | return mach_gettimeoffset() * 1000; |
| 93 | } |
| 94 | |
| 95 | static int __init rtc_init(void) |
| 96 | { |
| 97 | struct platform_device *pdev; |
| 98 | |
| 99 | if (!mach_hwclk) |
| 100 | return -ENODEV; |
| 101 | |
| 102 | pdev = platform_device_register_simple("rtc-generic", -1, NULL, 0); |
| 103 | if (IS_ERR(pdev)) |
| 104 | return PTR_ERR(pdev); |
| 105 | |
| 106 | return 0; |
| 107 | } |
| 108 | |
| 109 | module_init(rtc_init); |
| 110 | |
| 111 | #endif /* CONFIG_M68KCLASSIC */ |