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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/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
31/*
32 * timer_interrupt() needs to keep up the real-time clock,
33 * as well as call the "xtime_update()" routine every clocktick
34 */
35static 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
67void 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
83void __init time_init(void)
84{
85 mach_sched_init(timer_interrupt);
86}
87
88#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
89
90u32 arch_gettimeoffset(void)
91{
92 return mach_gettimeoffset() * 1000;
93}
94
95static 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
109module_init(rtc_init);
110
111#endif /* CONFIG_ARCH_USES_GETTIMEOFFSET */