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/*
* time.c: Baget/MIPS specific time handling details
*
* Copyright (C) 1998 Gleb Raiko & Vladimir Roganov
*/
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/param.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/timex.h>
#include <linux/spinlock.h>
#include <asm/bootinfo.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/ptrace.h>
#include <asm/system.h>
#include <asm/baget/baget.h>
extern rwlock_t xtime_lock;
/*
* To have precision clock, we need to fix available clock frequency
*/
#define FREQ_NOM 79125 /* Baget frequency ratio */
#define FREQ_DEN 10000
static inline int timer_intr_valid(void)
{
static unsigned long long ticks, valid_ticks;
if (ticks++ * FREQ_DEN >= valid_ticks * FREQ_NOM) {
/*
* We need no overflow checks,
* due baget unable to work 3000 years...
* At least without reboot...
*/
valid_ticks++;
return 1;
}
return 0;
}
void static timer_interrupt(int irq, void *dev_id, struct pt_regs * regs)
{
if (timer_intr_valid()) {
sti();
do_timer(regs);
}
}
static void __init timer_enable(void)
{
unsigned char ss0cr0 = vic_inb(VIC_SS0CR0);
ss0cr0 &= ~VIC_SS0CR0_TIMER_FREQ_MASK;
ss0cr0 |= VIC_SS0CR0_TIMER_FREQ_1000HZ;
vic_outb(ss0cr0, VIC_SS0CR0);
vic_outb(VIC_INT_IPL(6)|VIC_INT_NOAUTO|VIC_INT_EDGE|
VIC_INT_LOW|VIC_INT_ENABLE, VIC_LINT2);
}
static struct irqaction timer_irq =
{ timer_interrupt, SA_INTERRUPT, 0, "timer", NULL, NULL};
void __init time_init(void)
{
if (setup_baget_irq(BAGET_VIC_TIMER_IRQ, &timer_irq) < 0)
printk("time_init: unable request irq for system timer\n");
timer_enable();
/* We don't call sti() here, because it is too early for baget */
}
void do_gettimeofday(struct timeval *tv)
{
unsigned long flags;
read_lock_irqsave (&xtime_lock, flags);
*tv = xtime;
read_unlock_irqrestore (&xtime_lock, flags);
}
void do_settimeofday(struct timeval *tv)
{
write_lock_irq (&xtime_lock);
xtime = *tv;
time_adjust = 0; /* stop active adjtime() */
time_status |= STA_UNSYNC;
time_maxerror = NTP_PHASE_LIMIT;
time_esterror = NTP_PHASE_LIMIT;
write_unlock_irq (&xtime_lock);
}
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