/*
* arch/sh/kernel/time.c
*
* Copyright (C) 1999 Tetsuya Okada & Niibe Yutaka
* Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org>
* Copyright (C) 2002 - 2007 Paul Mundt
* Copyright (C) 2002 M. R. Brown <mrbrown@linux-sh.org>
*
* Some code taken from i386 version.
* Copyright (C) 1991, 1992, 1995 Linus Torvalds
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/profile.h>
#include <linux/timex.h>
#include <linux/sched.h>
#include <linux/clockchips.h>
#include <asm/clock.h>
#include <asm/rtc.h>
#include <asm/timer.h>
#include <asm/kgdb.h>
struct sys_timer *sys_timer;
/* Move this somewhere more sensible.. */
DEFINE_SPINLOCK(rtc_lock);
EXPORT_SYMBOL(rtc_lock);
/* Dummy RTC ops */
static void null_rtc_get_time(struct timespec *tv)
{
tv->tv_sec = mktime(2000, 1, 1, 0, 0, 0);
tv->tv_nsec = 0;
}
static int null_rtc_set_time(const time_t secs)
{
return 0;
}
/*
* Null high precision timer functions for systems lacking one.
*/
static cycle_t null_hpt_read(void)
{
return 0;
}
void (*rtc_sh_get_time)(struct timespec *) = null_rtc_get_time;
int (*rtc_sh_set_time)(const time_t) = null_rtc_set_time;
#ifndef CONFIG_GENERIC_TIME
void do_gettimeofday(struct timeval *tv)
{
unsigned long flags;
unsigned long seq;
unsigned long usec, sec;
do {
/*
* Turn off IRQs when grabbing xtime_lock, so that
* the sys_timer get_offset code doesn't have to handle it.
*/
seq = read_seqbegin_irqsave(&xtime_lock, flags);
usec = get_timer_offset();
sec = xtime.tv_sec;
usec += xtime.tv_nsec / NSEC_PER_USEC;
} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
while (usec >= 1000000) {
usec -= 1000000;
sec++;
}
tv->tv_sec = sec;
tv->tv_usec = usec;
}
EXPORT_SYMBOL(do_gettimeofday);
int do_settimeofday(struct timespec *tv)
{
time_t wtm_sec, sec = tv->tv_sec;
long wtm_nsec, nsec = tv->tv_nsec;
if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
return -EINVAL;
write_seqlock_irq(&xtime_lock);
/*
* This is revolting. We need to set "xtime" correctly. However, the
* value in this location is the value at the most recent update of
* wall time. Discover what correction gettimeofday() would have
* made, and then undo it!
*/
nsec -= get_timer_offset() * NSEC_PER_USEC;
wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
set_normalized_timespec(&xtime, sec, nsec);
set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
ntp_clear();
write_sequnlock_irq(&xtime_lock);
clock_was_set();
return 0;
}
EXPORT_SYMBOL(do_settimeofday);
#endif /* !CONFIG_GENERIC_TIME */
#ifndef CONFIG_GENERIC_CLOCKEVENTS
/* last time the RTC clock got updated */
static long last_rtc_update;
/*
* handle_timer_tick() needs to keep up the real-time clock,
* as well as call the "do_timer()" routine every clocktick
*/
void handle_timer_tick(void)
{
do_timer(1);
#ifndef CONFIG_SMP
update_process_times(user_mode(get_irq_regs()));
#endif
if (current->pid)
profile_tick(CPU_PROFILING);
#ifdef CONFIG_HEARTBEAT
if (sh_mv.mv_heartbeat != NULL)
sh_mv.mv_heartbeat();
#endif
/*
* If we have an externally synchronized Linux clock, then update
* RTC clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
* called as close as possible to 500 ms before the new second starts.
*/
if (ntp_synced() &&
xtime.tv_sec > last_rtc_update + 660 &&
(xtime.tv_nsec / 1000) >= 500000 - ((unsigned) TICK_SIZE) / 2 &&
(xtime.tv_nsec / 1000) <= 500000 + ((unsigned) TICK_SIZE) / 2) {
if (rtc_sh_set_time(xtime.tv_sec) == 0)
last_rtc_update = xtime.tv_sec;
else
/* do it again in 60s */
last_rtc_update = xtime.tv_sec - 600;
}
}
#endif /* !CONFIG_GENERIC_CLOCKEVENTS */
#ifdef CONFIG_PM
int timer_suspend(struct sys_device *dev, pm_message_t state)
{
struct sys_timer *sys_timer = container_of(dev, struct sys_timer, dev);
sys_timer->ops->stop();
return 0;
}
int timer_resume(struct sys_device *dev)
{
struct sys_timer *sys_timer = container_of(dev, struct sys_timer, dev);
sys_timer->ops->start();
return 0;
}
#else
#define timer_suspend NULL
#define timer_resume NULL
#endif
static struct sysdev_class timer_sysclass = {
set_kset_name("timer"),
.suspend = timer_suspend,
.resume = timer_resume,
};
static int __init timer_init_sysfs(void)
{
int ret = sysdev_class_register(&timer_sysclass);
if (ret != 0)
return ret;
sys_timer->dev.cls = &timer_sysclass;
return sysdev_register(&sys_timer->dev);
}
device_initcall(timer_init_sysfs);
void (*board_time_init)(void);
/*
* Shamelessly based on the MIPS and Sparc64 work.
*/
static unsigned long timer_ticks_per_nsec_quotient __read_mostly;
unsigned long sh_hpt_frequency = 0;
#define NSEC_PER_CYC_SHIFT 10
struct clocksource clocksource_sh = {
.name = "SuperH",
.rating = 200,
.mask = CLOCKSOURCE_MASK(32),
.read = null_hpt_read,
.shift = 16,
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
static void __init init_sh_clocksource(void)
{
if (!sh_hpt_frequency || clocksource_sh.read == null_hpt_read)
return;
clocksource_sh.mult = clocksource_hz2mult(sh_hpt_frequency,
clocksource_sh.shift);
timer_ticks_per_nsec_quotient =
clocksource_hz2mult(sh_hpt_frequency, NSEC_PER_CYC_SHIFT);
clocksource_register(&clocksource_sh);
}
#ifdef CONFIG_GENERIC_TIME
unsigned long long sched_clock(void)
{
unsigned long long ticks = clocksource_sh.read();
return (ticks * timer_ticks_per_nsec_quotient) >> NSEC_PER_CYC_SHIFT;
}
#endif
void __init time_init(void)
{
if (board_time_init)
board_time_init();
clk_init();
rtc_sh_get_time(&xtime);
set_normalized_timespec(&wall_to_monotonic,
-xtime.tv_sec, -xtime.tv_nsec);
/*
* Find the timer to use as the system timer, it will be
* initialized for us.
*/
sys_timer = get_sys_timer();
printk(KERN_INFO "Using %s for system timer\n", sys_timer->name);
if (sys_timer->ops->read)
clocksource_sh.read = sys_timer->ops->read;
init_sh_clocksource();
if (sh_hpt_frequency)
printk("Using %lu.%03lu MHz high precision timer.\n",
((sh_hpt_frequency + 500) / 1000) / 1000,
((sh_hpt_frequency + 500) / 1000) % 1000);
#if defined(CONFIG_SH_KGDB)
/*
* Set up kgdb as requested. We do it here because the serial
* init uses the timer vars we just set up for figuring baud.
*/
kgdb_init();
#endif
}
