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/*
* linux/arch/arm/mach-nuc93x/time.c
*
* Copyright (c) 2009 Nuvoton technology corporation.
*
* Wan ZongShun <mcuos.com@gmail.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
*/
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/leds.h>
#include <asm/mach-types.h>
#include <asm/mach/irq.h>
#include <asm/mach/time.h>
#include <mach/system.h>
#include <mach/map.h>
#include <mach/regs-timer.h>
#define RESETINT 0x01
#define PERIOD (0x01 << 27)
#define ONESHOT (0x00 << 27)
#define COUNTEN (0x01 << 30)
#define INTEN (0x01 << 29)
#define TICKS_PER_SEC 100
#define PRESCALE 0x63 /* Divider = prescale + 1 */
unsigned int timer0_load;
static unsigned long nuc93x_gettimeoffset(void)
{
return 0;
}
/*IRQ handler for the timer*/
static irqreturn_t nuc93x_timer_interrupt(int irq, void *dev_id)
{
timer_tick();
__raw_writel(0x01, REG_TISR); /* clear TIF0 */
return IRQ_HANDLED;
}
static struct irqaction nuc93x_timer_irq = {
.name = "nuc93x Timer Tick",
.flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
.handler = nuc93x_timer_interrupt,
};
/*Set up timer reg.*/
static void nuc93x_timer_setup(void)
{
struct clk *ck_ext = clk_get(NULL, "ext");
struct clk *ck_timer = clk_get(NULL, "timer");
unsigned int rate, val = 0;
BUG_ON(IS_ERR(ck_ext) || IS_ERR(ck_timer));
clk_enable(ck_timer);
rate = clk_get_rate(ck_ext);
clk_put(ck_ext);
rate = rate / (PRESCALE + 0x01);
/* set a known state */
__raw_writel(0x00, REG_TCSR0);
__raw_writel(RESETINT, REG_TISR);
timer0_load = (rate / TICKS_PER_SEC);
__raw_writel(timer0_load, REG_TICR0);
val |= (PERIOD | COUNTEN | INTEN | PRESCALE);
__raw_writel(val, REG_TCSR0);
}
static void __init nuc93x_timer_init(void)
{
nuc93x_timer_setup();
setup_irq(IRQ_TIMER0, &nuc93x_timer_irq);
}
struct sys_timer nuc93x_timer = {
.init = nuc93x_timer_init,
.offset = nuc93x_gettimeoffset,
.resume = nuc93x_timer_setup
};
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