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
set_rtc_mmss(unsigned long nowtime)31 static 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 "xtime_update()" routine every clocktick
41 */
timer_interrupt(int irq,void * dummy)42 static irqreturn_t timer_interrupt(int irq, void *dummy)
43 {
44 xtime_update(1);
45 update_process_times(user_mode(get_irq_regs()));
46 profile_tick(CPU_PROFILING);
47
48 #ifdef CONFIG_HEARTBEAT
49 /* use power LED as a heartbeat instead -- much more useful
50 for debugging -- based on the version for PReP by Cort */
51 /* acts like an actual heart beat -- ie thump-thump-pause... */
52 if (mach_heartbeat) {
53 static unsigned cnt = 0, period = 0, dist = 0;
54
55 if (cnt == 0 || cnt == dist)
56 mach_heartbeat( 1 );
57 else if (cnt == 7 || cnt == dist+7)
58 mach_heartbeat( 0 );
59
60 if (++cnt > period) {
61 cnt = 0;
62 /* The hyperbolic function below modifies the heartbeat period
63 * length in dependency of the current (5min) load. It goes
64 * through the points f(0)=126, f(1)=86, f(5)=51,
65 * f(inf)->30. */
66 period = ((672<<FSHIFT)/(5*avenrun[0]+(7<<FSHIFT))) + 30;
67 dist = period / 4;
68 }
69 }
70 #endif /* CONFIG_HEARTBEAT */
71 return IRQ_HANDLED;
72 }
73
read_persistent_clock(struct timespec * ts)74 void read_persistent_clock(struct timespec *ts)
75 {
76 struct rtc_time time;
77 ts->tv_sec = 0;
78 ts->tv_nsec = 0;
79
80 if (mach_hwclk) {
81 mach_hwclk(0, &time);
82
83 if ((time.tm_year += 1900) < 1970)
84 time.tm_year += 100;
85 ts->tv_sec = mktime(time.tm_year, time.tm_mon, time.tm_mday,
86 time.tm_hour, time.tm_min, time.tm_sec);
87 }
88 }
89
time_init(void)90 void __init time_init(void)
91 {
92 mach_sched_init(timer_interrupt);
93 }
94
arch_gettimeoffset(void)95 u32 arch_gettimeoffset(void)
96 {
97 return mach_gettimeoffset() * 1000;
98 }
99
rtc_init(void)100 static int __init rtc_init(void)
101 {
102 struct platform_device *pdev;
103
104 if (!mach_hwclk)
105 return -ENODEV;
106
107 pdev = platform_device_register_simple("rtc-generic", -1, NULL, 0);
108 if (IS_ERR(pdev))
109 return PTR_ERR(pdev);
110
111 return 0;
112 }
113
114 module_init(rtc_init);
115