2 * arch/sh/kernel/time_32.c
4 * Copyright (C) 1999 Tetsuya Okada & Niibe Yutaka
5 * Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org>
6 * Copyright (C) 2002 - 2009 Paul Mundt
7 * Copyright (C) 2002 M. R. Brown <mrbrown@linux-sh.org>
9 * Some code taken from i386 version.
10 * Copyright (C) 1991, 1992, 1995 Linus Torvalds
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/init.h>
15 #include <linux/profile.h>
16 #include <linux/timex.h>
17 #include <linux/sched.h>
18 #include <linux/clockchips.h>
19 #include <linux/mc146818rtc.h> /* for rtc_lock */
20 #include <linux/platform_device.h>
21 #include <linux/smp.h>
22 #include <linux/rtc.h>
23 #include <asm/clock.h>
25 #include <asm/timer.h>
28 struct sys_timer *sys_timer;
30 /* Move this somewhere more sensible.. */
31 DEFINE_SPINLOCK(rtc_lock);
32 EXPORT_SYMBOL(rtc_lock);
35 static void null_rtc_get_time(struct timespec *tv)
37 tv->tv_sec = mktime(2000, 1, 1, 0, 0, 0);
41 static int null_rtc_set_time(const time_t secs)
46 void (*rtc_sh_get_time)(struct timespec *) = null_rtc_get_time;
47 int (*rtc_sh_set_time)(const time_t) = null_rtc_set_time;
49 unsigned int get_rtc_time(struct rtc_time *tm)
51 if (rtc_sh_get_time != null_rtc_get_time) {
55 rtc_time_to_tm(tv.tv_sec, tm);
60 EXPORT_SYMBOL(get_rtc_time);
62 int set_rtc_time(struct rtc_time *tm)
66 rtc_tm_to_time(tm, &secs);
67 return rtc_sh_set_time(secs);
69 EXPORT_SYMBOL(set_rtc_time);
71 static int __init rtc_generic_init(void)
73 struct platform_device *pdev;
75 if (rtc_sh_get_time == null_rtc_get_time)
78 pdev = platform_device_register_simple("rtc-generic", -1, NULL, 0);
84 module_init(rtc_generic_init);
86 /* last time the RTC clock got updated */
87 static long last_rtc_update;
90 * handle_timer_tick() needs to keep up the real-time clock,
91 * as well as call the "do_timer()" routine every clocktick
93 void handle_timer_tick(void)
96 profile_tick(CPU_PROFILING);
99 * Here we are in the timer irq handler. We just have irqs locally
100 * disabled but we don't know if the timer_bh is running on the other
101 * CPU. We need to avoid to SMP race with it. NOTE: we don' t need
102 * the irq version of write_lock because as just said we have irq
103 * locally disabled. -arca
105 write_seqlock(&xtime_lock);
109 * If we have an externally synchronized Linux clock, then update
110 * RTC clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
111 * called as close as possible to 500 ms before the new second starts.
114 xtime.tv_sec > last_rtc_update + 660 &&
115 (xtime.tv_nsec / 1000) >= 500000 - ((unsigned) TICK_SIZE) / 2 &&
116 (xtime.tv_nsec / 1000) <= 500000 + ((unsigned) TICK_SIZE) / 2) {
117 if (rtc_sh_set_time(xtime.tv_sec) == 0)
118 last_rtc_update = xtime.tv_sec;
120 /* do it again in 60s */
121 last_rtc_update = xtime.tv_sec - 600;
123 write_sequnlock(&xtime_lock);
126 update_process_times(user_mode(get_irq_regs()));
131 int timer_suspend(struct sys_device *dev, pm_message_t state)
133 struct sys_timer *sys_timer = container_of(dev, struct sys_timer, dev);
135 sys_timer->ops->stop();
140 int timer_resume(struct sys_device *dev)
142 struct sys_timer *sys_timer = container_of(dev, struct sys_timer, dev);
144 sys_timer->ops->start();
149 #define timer_suspend NULL
150 #define timer_resume NULL
153 static struct sysdev_class timer_sysclass = {
155 .suspend = timer_suspend,
156 .resume = timer_resume,
159 static int __init timer_init_sysfs(void)
166 ret = sysdev_class_register(&timer_sysclass);
170 sys_timer->dev.cls = &timer_sysclass;
171 return sysdev_register(&sys_timer->dev);
173 device_initcall(timer_init_sysfs);
175 void (*board_time_init)(void);
177 struct clocksource clocksource_sh = {
181 unsigned long long sched_clock(void)
183 unsigned long long cycles;
185 /* jiffies based sched_clock if no clocksource is installed */
186 if (!clocksource_sh.rating)
187 return (unsigned long long)jiffies * (NSEC_PER_SEC / HZ);
189 cycles = clocksource_sh.read(&clocksource_sh);
190 return cyc2ns(&clocksource_sh, cycles);
193 static void __init sh_late_time_init(void)
196 * Make sure all compiled-in early timers register themselves.
197 * Run probe() for one "earlytimer" device.
199 early_platform_driver_register_all("earlytimer");
200 if (early_platform_driver_probe("earlytimer", 1, 0))
204 * Find the timer to use as the system timer, it will be
205 * initialized for us.
207 sys_timer = get_sys_timer();
208 if (unlikely(!sys_timer))
209 panic("System timer missing.\n");
211 printk(KERN_INFO "Using %s for system timer\n", sys_timer->name);
214 void __init time_init(void)
221 rtc_sh_get_time(&xtime);
222 set_normalized_timespec(&wall_to_monotonic,
223 -xtime.tv_sec, -xtime.tv_nsec);
225 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
226 local_timer_setup(smp_processor_id());
229 late_time_init = sh_late_time_init;