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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/export.h>
15#include <linux/module.h>
16#include <linux/sched.h>
17#include <linux/kernel.h>
18#include <linux/param.h>
19#include <linux/string.h>
20#include <linux/mm.h>
21#include <linux/rtc.h>
22#include <linux/platform_device.h>
23
24#include <asm/machdep.h>
25#include <asm/io.h>
26#include <asm/irq_regs.h>
27
28#include <linux/time.h>
29#include <linux/timex.h>
30#include <linux/profile.h>
31
32
33unsigned long (*mach_random_get_entropy)(void);
34EXPORT_SYMBOL_GPL(mach_random_get_entropy);
35
36
37/*
38 * timer_interrupt() needs to keep up the real-time clock,
39 * as well as call the "xtime_update()" routine every clocktick
40 */
41static irqreturn_t timer_interrupt(int irq, void *dummy)
42{
43 xtime_update(1);
44 update_process_times(user_mode(get_irq_regs()));
45 profile_tick(CPU_PROFILING);
46
47#ifdef CONFIG_HEARTBEAT
48 /* use power LED as a heartbeat instead -- much more useful
49 for debugging -- based on the version for PReP by Cort */
50 /* acts like an actual heart beat -- ie thump-thump-pause... */
51 if (mach_heartbeat) {
52 static unsigned cnt = 0, period = 0, dist = 0;
53
54 if (cnt == 0 || cnt == dist)
55 mach_heartbeat( 1 );
56 else if (cnt == 7 || cnt == dist+7)
57 mach_heartbeat( 0 );
58
59 if (++cnt > period) {
60 cnt = 0;
61 /* The hyperbolic function below modifies the heartbeat period
62 * length in dependency of the current (5min) load. It goes
63 * through the points f(0)=126, f(1)=86, f(5)=51,
64 * f(inf)->30. */
65 period = ((672<<FSHIFT)/(5*avenrun[0]+(7<<FSHIFT))) + 30;
66 dist = period / 4;
67 }
68 }
69#endif /* CONFIG_HEARTBEAT */
70 return IRQ_HANDLED;
71}
72
73void read_persistent_clock(struct timespec *ts)
74{
75 struct rtc_time time;
76 ts->tv_sec = 0;
77 ts->tv_nsec = 0;
78
79 if (mach_hwclk) {
80 mach_hwclk(0, &time);
81
82 if ((time.tm_year += 1900) < 1970)
83 time.tm_year += 100;
84 ts->tv_sec = mktime(time.tm_year, time.tm_mon, time.tm_mday,
85 time.tm_hour, time.tm_min, time.tm_sec);
86 }
87}
88
89#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
90
91static int __init rtc_init(void)
92{
93 struct platform_device *pdev;
94
95 if (!mach_hwclk)
96 return -ENODEV;
97
98 pdev = platform_device_register_simple("rtc-generic", -1, NULL, 0);
99 return PTR_ERR_OR_ZERO(pdev);
100}
101
102module_init(rtc_init);
103
104#endif /* CONFIG_ARCH_USES_GETTIMEOFFSET */
105
106void __init time_init(void)
107{
108 mach_sched_init(timer_interrupt);
109}