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/*
* linux/arch/arm/mach-w90x900/time.c
*
* Based on linux/arch/arm/plat-s3c24xx/time.c by Ben Dooks
*
* Copyright (c) 2009 Nuvoton technology corporation
* All rights reserved.
*
* 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 <linux/clocksource.h>
#include <linux/clockchips.h>
#include <asm/mach-types.h>
#include <asm/mach/irq.h>
#include <asm/mach/time.h>
#include <mach/map.h>
#include <mach/regs-timer.h>
#define RESETINT 0x1f
#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 void nuc900_clockevent_setmode(enum clock_event_mode mode,
struct clock_event_device *clk)
{
unsigned int val;
val = __raw_readl(REG_TCSR0);
val &= ~(0x03 << 27);
switch (mode) {
case CLOCK_EVT_MODE_PERIODIC:
__raw_writel(timer0_load, REG_TICR0);
val |= (PERIOD | COUNTEN | INTEN | PRESCALE);
break;
case CLOCK_EVT_MODE_ONESHOT:
val |= (ONESHOT | COUNTEN | INTEN | PRESCALE);
break;
case CLOCK_EVT_MODE_UNUSED:
case CLOCK_EVT_MODE_SHUTDOWN:
case CLOCK_EVT_MODE_RESUME:
break;
}
__raw_writel(val, REG_TCSR0);
}
static int nuc900_clockevent_setnextevent(unsigned long evt,
struct clock_event_device *clk)
{
unsigned int val;
__raw_writel(evt, REG_TICR0);
val = __raw_readl(REG_TCSR0);
val |= (COUNTEN | INTEN | PRESCALE);
__raw_writel(val, REG_TCSR0);
return 0;
}
static struct clock_event_device nuc900_clockevent_device = {
.name = "nuc900-timer0",
.shift = 32,
.features = CLOCK_EVT_MODE_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
.set_mode = nuc900_clockevent_setmode,
.set_next_event = nuc900_clockevent_setnextevent,
.rating = 300,
};
/*IRQ handler for the timer*/
static irqreturn_t nuc900_timer0_interrupt(int irq, void *dev_id)
{
struct clock_event_device *evt = &nuc900_clockevent_device;
__raw_writel(0x01, REG_TISR); /* clear TIF0 */
evt->event_handler(evt);
return IRQ_HANDLED;
}
static struct irqaction nuc900_timer0_irq = {
.name = "nuc900-timer0",
.flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
.handler = nuc900_timer0_interrupt,
};
static void __init nuc900_clockevents_init(unsigned int rate)
{
nuc900_clockevent_device.mult = div_sc(rate, NSEC_PER_SEC,
nuc900_clockevent_device.shift);
nuc900_clockevent_device.max_delta_ns = clockevent_delta2ns(0xffffffff,
&nuc900_clockevent_device);
nuc900_clockevent_device.min_delta_ns = clockevent_delta2ns(0xf,
&nuc900_clockevent_device);
nuc900_clockevent_device.cpumask = cpumask_of(0);
clockevents_register_device(&nuc900_clockevent_device);
}
static cycle_t nuc900_get_cycles(struct clocksource *cs)
{
return ~__raw_readl(REG_TDR1);
}
static struct clocksource clocksource_nuc900 = {
.name = "nuc900-timer1",
.rating = 200,
.read = nuc900_get_cycles,
.mask = CLOCKSOURCE_MASK(32),
.shift = 20,
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
static void __init nuc900_clocksource_init(unsigned int rate)
{
unsigned int val;
__raw_writel(0xffffffff, REG_TICR1);
val = __raw_readl(REG_TCSR1);
val |= (COUNTEN | PERIOD);
__raw_writel(val, REG_TCSR1);
clocksource_nuc900.mult =
clocksource_khz2mult((rate / 1000), clocksource_nuc900.shift);
clocksource_register(&clocksource_nuc900);
}
static void __init nuc900_timer_init(void)
{
struct clk *ck_ext = clk_get(NULL, "ext");
unsigned int rate;
BUG_ON(IS_ERR(ck_ext));
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(0x00, REG_TCSR1);
__raw_writel(RESETINT, REG_TISR);
timer0_load = (rate / TICKS_PER_SEC);
setup_irq(IRQ_TIMER0, &nuc900_timer0_irq);
nuc900_clocksource_init(rate);
nuc900_clockevents_init(rate);
}
struct sys_timer nuc900_timer = {
.init = nuc900_timer_init,
};
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