linux/arch/arm/mach-footbridge/dc21285-timer.c

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/*
* linux/arch/arm/mach-footbridge/dc21285-timer.c
*
* Copyright (C) 1998 Russell King.
* Copyright (C) 1998 Phil Blundell
*/
#include <linux/init.h>
#include <linux/interrupt.h>
#include <asm/irq.h>
#include <asm/hardware/dec21285.h>
#include <asm/mach/time.h>
#include "common.h"
/*
* Footbridge timer 1 support.
*/
static unsigned long timer1_latch;
static unsigned long timer1_gettimeoffset (void)
{
unsigned long value = timer1_latch - *CSR_TIMER1_VALUE;
return ((tick_nsec / 1000) * value) / timer1_latch;
}
static irqreturn_t
timer1_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
write_seqlock(&xtime_lock);
*CSR_TIMER1_CLR = 0;
timer_tick(regs);
write_sequnlock(&xtime_lock);
return IRQ_HANDLED;
}
static struct irqaction footbridge_timer_irq = {
.name = "Timer1 timer tick",
.handler = timer1_interrupt,
.flags = SA_INTERRUPT | SA_TIMER,
};
/*
* Set up timer interrupt.
*/
static void __init footbridge_timer_init(void)
{
timer1_latch = (mem_fclk_21285 + 8 * HZ) / (16 * HZ);
*CSR_TIMER1_CLR = 0;
*CSR_TIMER1_LOAD = timer1_latch;
*CSR_TIMER1_CNTL = TIMER_CNTL_ENABLE | TIMER_CNTL_AUTORELOAD | TIMER_CNTL_DIV16;
setup_irq(IRQ_TIMER1, &footbridge_timer_irq);
isa_rtc_init();
}
struct sys_timer footbridge_timer = {
.init = footbridge_timer_init,
.offset = timer1_gettimeoffset,
};