196 lines
4.6 KiB
C
196 lines
4.6 KiB
C
/*
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* arch/sh/kernel/time.c
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*
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* Copyright (C) 1999 Tetsuya Okada & Niibe Yutaka
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* Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org>
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* Copyright (C) 2002, 2003, 2004, 2005 Paul Mundt
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* Copyright (C) 2002 M. R. Brown <mrbrown@linux-sh.org>
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*
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* Some code taken from i386 version.
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* Copyright (C) 1991, 1992, 1995 Linus Torvalds
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/profile.h>
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#include <asm/clock.h>
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#include <asm/rtc.h>
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#include <asm/timer.h>
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#include <asm/kgdb.h>
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extern unsigned long wall_jiffies;
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struct sys_timer *sys_timer;
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/* Move this somewhere more sensible.. */
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DEFINE_SPINLOCK(rtc_lock);
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EXPORT_SYMBOL(rtc_lock);
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/* XXX: Can we initialize this in a routine somewhere? Dreamcast doesn't want
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* these routines anywhere... */
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#ifdef CONFIG_SH_RTC
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void (*rtc_get_time)(struct timespec *) = sh_rtc_gettimeofday;
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int (*rtc_set_time)(const time_t) = sh_rtc_settimeofday;
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#else
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void (*rtc_get_time)(struct timespec *);
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int (*rtc_set_time)(const time_t);
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#endif
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/*
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* Scheduler clock - returns current time in nanosec units.
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*/
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unsigned long long __attribute__ ((weak)) sched_clock(void)
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{
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return (unsigned long long)jiffies * (1000000000 / HZ);
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}
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void do_gettimeofday(struct timeval *tv)
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{
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unsigned long seq;
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unsigned long usec, sec;
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unsigned long lost;
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do {
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seq = read_seqbegin(&xtime_lock);
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usec = get_timer_offset();
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lost = jiffies - wall_jiffies;
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if (lost)
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usec += lost * (1000000 / HZ);
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sec = xtime.tv_sec;
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usec += xtime.tv_nsec / 1000;
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} while (read_seqretry(&xtime_lock, seq));
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while (usec >= 1000000) {
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usec -= 1000000;
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sec++;
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}
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tv->tv_sec = sec;
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tv->tv_usec = usec;
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}
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EXPORT_SYMBOL(do_gettimeofday);
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int do_settimeofday(struct timespec *tv)
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{
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time_t wtm_sec, sec = tv->tv_sec;
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long wtm_nsec, nsec = tv->tv_nsec;
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if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
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return -EINVAL;
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write_seqlock_irq(&xtime_lock);
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/*
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* This is revolting. We need to set "xtime" correctly. However, the
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* value in this location is the value at the most recent update of
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* wall time. Discover what correction gettimeofday() would have
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* made, and then undo it!
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*/
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nsec -= 1000 * (get_timer_offset() +
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(jiffies - wall_jiffies) * (1000000 / HZ));
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wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
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wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
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set_normalized_timespec(&xtime, sec, nsec);
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set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
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ntp_clear();
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write_sequnlock_irq(&xtime_lock);
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clock_was_set();
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return 0;
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}
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EXPORT_SYMBOL(do_settimeofday);
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/* last time the RTC clock got updated */
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static long last_rtc_update;
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/*
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* handle_timer_tick() needs to keep up the real-time clock,
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* as well as call the "do_timer()" routine every clocktick
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*/
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void handle_timer_tick(struct pt_regs *regs)
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{
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do_timer(regs);
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#ifndef CONFIG_SMP
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update_process_times(user_mode(regs));
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#endif
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profile_tick(CPU_PROFILING, regs);
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#ifdef CONFIG_HEARTBEAT
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if (sh_mv.mv_heartbeat != NULL)
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sh_mv.mv_heartbeat();
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#endif
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/*
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* If we have an externally synchronized Linux clock, then update
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* RTC clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
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* called as close as possible to 500 ms before the new second starts.
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*/
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if (ntp_synced() &&
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xtime.tv_sec > last_rtc_update + 660 &&
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(xtime.tv_nsec / 1000) >= 500000 - ((unsigned) TICK_SIZE) / 2 &&
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(xtime.tv_nsec / 1000) <= 500000 + ((unsigned) TICK_SIZE) / 2) {
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if (rtc_set_time(xtime.tv_sec) == 0)
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last_rtc_update = xtime.tv_sec;
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else
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/* do it again in 60s */
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last_rtc_update = xtime.tv_sec - 600;
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}
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}
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static struct sysdev_class timer_sysclass = {
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set_kset_name("timer"),
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};
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static int __init timer_init_sysfs(void)
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{
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int ret = sysdev_class_register(&timer_sysclass);
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if (ret != 0)
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return ret;
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sys_timer->dev.cls = &timer_sysclass;
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return sysdev_register(&sys_timer->dev);
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}
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device_initcall(timer_init_sysfs);
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void (*board_time_init)(void);
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void __init time_init(void)
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{
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if (board_time_init)
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board_time_init();
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clk_init();
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if (rtc_get_time) {
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rtc_get_time(&xtime);
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} else {
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xtime.tv_sec = mktime(2000, 1, 1, 0, 0, 0);
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xtime.tv_nsec = 0;
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}
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set_normalized_timespec(&wall_to_monotonic,
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-xtime.tv_sec, -xtime.tv_nsec);
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/*
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* Find the timer to use as the system timer, it will be
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* initialized for us.
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*/
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sys_timer = get_sys_timer();
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printk(KERN_INFO "Using %s for system timer\n", sys_timer->name);
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#if defined(CONFIG_SH_KGDB)
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/*
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* Set up kgdb as requested. We do it here because the serial
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* init uses the timer vars we just set up for figuring baud.
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*/
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kgdb_init();
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#endif
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}
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