linux/arch/m68k/kernel/time.c

155 lines
3.7 KiB
C

/*
* linux/arch/m68k/kernel/time.c
*
* Copyright (C) 1991, 1992, 1995 Linus Torvalds
*
* This file contains the m68k-specific time handling details.
* Most of the stuff is located in the machine specific files.
*
* 1997-09-10 Updated NTP code according to technical memorandum Jan '96
* "A Kernel Model for Precision Timekeeping" by Dave Mills
*/
#include <linux/errno.h>
#include <linux/export.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/sched/loadavg.h>
#include <linux/kernel.h>
#include <linux/param.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/rtc.h>
#include <linux/platform_device.h>
#include <asm/machdep.h>
#include <asm/io.h>
#include <asm/irq_regs.h>
#include <linux/time.h>
#include <linux/timex.h>
#include <linux/profile.h>
unsigned long (*mach_random_get_entropy)(void);
EXPORT_SYMBOL_GPL(mach_random_get_entropy);
/*
* timer_interrupt() needs to keep up the real-time clock,
* as well as call the "xtime_update()" routine every clocktick
*/
static irqreturn_t timer_interrupt(int irq, void *dummy)
{
xtime_update(1);
update_process_times(user_mode(get_irq_regs()));
profile_tick(CPU_PROFILING);
#ifdef CONFIG_HEARTBEAT
/* use power LED as a heartbeat instead -- much more useful
for debugging -- based on the version for PReP by Cort */
/* acts like an actual heart beat -- ie thump-thump-pause... */
if (mach_heartbeat) {
static unsigned cnt = 0, period = 0, dist = 0;
if (cnt == 0 || cnt == dist)
mach_heartbeat( 1 );
else if (cnt == 7 || cnt == dist+7)
mach_heartbeat( 0 );
if (++cnt > period) {
cnt = 0;
/* The hyperbolic function below modifies the heartbeat period
* length in dependency of the current (5min) load. It goes
* through the points f(0)=126, f(1)=86, f(5)=51,
* f(inf)->30. */
period = ((672<<FSHIFT)/(5*avenrun[0]+(7<<FSHIFT))) + 30;
dist = period / 4;
}
}
#endif /* CONFIG_HEARTBEAT */
return IRQ_HANDLED;
}
void read_persistent_clock(struct timespec *ts)
{
struct rtc_time time;
ts->tv_sec = 0;
ts->tv_nsec = 0;
if (mach_hwclk) {
mach_hwclk(0, &time);
if ((time.tm_year += 1900) < 1970)
time.tm_year += 100;
ts->tv_sec = mktime(time.tm_year, time.tm_mon, time.tm_mday,
time.tm_hour, time.tm_min, time.tm_sec);
}
}
#if defined(CONFIG_ARCH_USES_GETTIMEOFFSET) && IS_ENABLED(CONFIG_RTC_DRV_GENERIC)
static int rtc_generic_get_time(struct device *dev, struct rtc_time *tm)
{
mach_hwclk(0, tm);
return 0;
}
static int rtc_generic_set_time(struct device *dev, struct rtc_time *tm)
{
if (mach_hwclk(1, tm) < 0)
return -EOPNOTSUPP;
return 0;
}
static int rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
{
struct rtc_pll_info pll;
struct rtc_pll_info __user *argp = (void __user *)arg;
switch (cmd) {
case RTC_PLL_GET:
if (!mach_get_rtc_pll || mach_get_rtc_pll(&pll))
return -EINVAL;
return copy_to_user(argp, &pll, sizeof pll) ? -EFAULT : 0;
case RTC_PLL_SET:
if (!mach_set_rtc_pll)
return -EINVAL;
if (!capable(CAP_SYS_TIME))
return -EACCES;
if (copy_from_user(&pll, argp, sizeof(pll)))
return -EFAULT;
return mach_set_rtc_pll(&pll);
}
return -ENOIOCTLCMD;
}
static const struct rtc_class_ops generic_rtc_ops = {
.ioctl = rtc_ioctl,
.read_time = rtc_generic_get_time,
.set_time = rtc_generic_set_time,
};
static int __init rtc_init(void)
{
struct platform_device *pdev;
if (!mach_hwclk)
return -ENODEV;
pdev = platform_device_register_data(NULL, "rtc-generic", -1,
&generic_rtc_ops,
sizeof(generic_rtc_ops));
return PTR_ERR_OR_ZERO(pdev);
}
module_init(rtc_init);
#endif /* CONFIG_ARCH_USES_GETTIMEOFFSET */
void __init time_init(void)
{
mach_sched_init(timer_interrupt);
}