2 * arch/sh/kernel/time.c
4 * Copyright (C) 1999 Tetsuya Okada & Niibe Yutaka
5 * Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org>
6 * Copyright (C) 2002 - 2006 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 <asm/clock.h>
18 #include <asm/timer.h>
21 struct sys_timer *sys_timer;
23 /* Move this somewhere more sensible.. */
24 DEFINE_SPINLOCK(rtc_lock);
25 EXPORT_SYMBOL(rtc_lock);
28 static void null_rtc_get_time(struct timespec *tv)
30 tv->tv_sec = mktime(2000, 1, 1, 0, 0, 0);
34 static int null_rtc_set_time(const time_t secs)
39 void (*rtc_sh_get_time)(struct timespec *) = null_rtc_get_time;
40 int (*rtc_sh_set_time)(const time_t) = null_rtc_set_time;
43 * Scheduler clock - returns current time in nanosec units.
45 unsigned long long __attribute__ ((weak)) sched_clock(void)
47 return (unsigned long long)jiffies * (1000000000 / HZ);
50 #ifndef CONFIG_GENERIC_TIME
51 void do_gettimeofday(struct timeval *tv)
54 unsigned long usec, sec;
57 seq = read_seqbegin(&xtime_lock);
58 usec = get_timer_offset();
60 usec += xtime.tv_nsec / 1000;
61 } while (read_seqretry(&xtime_lock, seq));
63 while (usec >= 1000000) {
71 EXPORT_SYMBOL(do_gettimeofday);
73 int do_settimeofday(struct timespec *tv)
75 time_t wtm_sec, sec = tv->tv_sec;
76 long wtm_nsec, nsec = tv->tv_nsec;
78 if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
81 write_seqlock_irq(&xtime_lock);
83 * This is revolting. We need to set "xtime" correctly. However, the
84 * value in this location is the value at the most recent update of
85 * wall time. Discover what correction gettimeofday() would have
86 * made, and then undo it!
88 nsec -= 1000 * get_timer_offset();
90 wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
91 wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
93 set_normalized_timespec(&xtime, sec, nsec);
94 set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
97 write_sequnlock_irq(&xtime_lock);
102 EXPORT_SYMBOL(do_settimeofday);
103 #endif /* !CONFIG_GENERIC_TIME */
105 /* last time the RTC clock got updated */
106 static long last_rtc_update;
109 * handle_timer_tick() needs to keep up the real-time clock,
110 * as well as call the "do_timer()" routine every clocktick
112 void handle_timer_tick(struct pt_regs *regs)
116 update_process_times(user_mode(regs));
118 profile_tick(CPU_PROFILING, regs);
120 #ifdef CONFIG_HEARTBEAT
121 if (sh_mv.mv_heartbeat != NULL)
122 sh_mv.mv_heartbeat();
126 * If we have an externally synchronized Linux clock, then update
127 * RTC clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
128 * called as close as possible to 500 ms before the new second starts.
131 xtime.tv_sec > last_rtc_update + 660 &&
132 (xtime.tv_nsec / 1000) >= 500000 - ((unsigned) TICK_SIZE) / 2 &&
133 (xtime.tv_nsec / 1000) <= 500000 + ((unsigned) TICK_SIZE) / 2) {
134 if (rtc_sh_set_time(xtime.tv_sec) == 0)
135 last_rtc_update = xtime.tv_sec;
137 /* do it again in 60s */
138 last_rtc_update = xtime.tv_sec - 600;
143 int timer_suspend(struct sys_device *dev, pm_message_t state)
145 struct sys_timer *sys_timer = container_of(dev, struct sys_timer, dev);
147 sys_timer->ops->stop();
152 int timer_resume(struct sys_device *dev)
154 struct sys_timer *sys_timer = container_of(dev, struct sys_timer, dev);
156 sys_timer->ops->start();
161 #define timer_suspend NULL
162 #define timer_resume NULL
165 static struct sysdev_class timer_sysclass = {
166 set_kset_name("timer"),
167 .suspend = timer_suspend,
168 .resume = timer_resume,
171 static int __init timer_init_sysfs(void)
173 int ret = sysdev_class_register(&timer_sysclass);
177 sys_timer->dev.cls = &timer_sysclass;
178 return sysdev_register(&sys_timer->dev);
180 device_initcall(timer_init_sysfs);
182 void (*board_time_init)(void);
184 void __init time_init(void)
191 rtc_sh_get_time(&xtime);
192 set_normalized_timespec(&wall_to_monotonic,
193 -xtime.tv_sec, -xtime.tv_nsec);
196 * Find the timer to use as the system timer, it will be
197 * initialized for us.
199 sys_timer = get_sys_timer();
200 printk(KERN_INFO "Using %s for system timer\n", sys_timer->name);
202 #if defined(CONFIG_SH_KGDB)
204 * Set up kgdb as requested. We do it here because the serial
205 * init uses the timer vars we just set up for figuring baud.