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/*
* linux/arch/arm/mach-mmp/time.c
*
* Support for clocksource and clockevents
*
* Copyright (C) 2008 Marvell International Ltd.
* All rights reserved.
*
* 2008-04-11: Jason Chagas <Jason.chagas@marvell.com>
* 2008-10-08: Bin Yang <bin.yang@marvell.com>
*
* The timers module actually includes three timers, each timer with up to
* three match comparators. Timer #0 is used here in free-running mode as
* the clock source, and match comparator #1 used as clock event device.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/clockchips.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <asm/sched_clock.h>
#include <mach/addr-map.h>
#include <mach/regs-timers.h>
#include <mach/regs-apbc.h>
#include <mach/irqs.h>
#include <mach/cputype.h>
#include <asm/mach/time.h>
#include "clock.h"
#define TIMERS_VIRT_BASE TIMERS1_VIRT_BASE
#define MAX_DELTA (0xfffffffe)
#define MIN_DELTA (16)
/*
* FIXME: the timer needs some delay to stablize the counter capture
*/
static inline uint32_t timer_read(void)
{
int delay = 100;
__raw_writel(1, TIMERS_VIRT_BASE + TMR_CVWR(1));
while (delay--)
cpu_relax();
return __raw_readl(TIMERS_VIRT_BASE + TMR_CVWR(1));
}
static u32 notrace mmp_read_sched_clock(void)
{
return timer_read();
}
static irqreturn_t timer_interrupt(int irq, void *dev_id)
{
struct clock_event_device *c = dev_id;
/*
* Clear pending interrupt status.
*/
__raw_writel(0x01, TIMERS_VIRT_BASE + TMR_ICR(0));
/*
* Disable timer 0.
*/
__raw_writel(0x02, TIMERS_VIRT_BASE + TMR_CER);
c->event_handler(c);
return IRQ_HANDLED;
}
static int timer_set_next_event(unsigned long delta,
struct clock_event_device *dev)
{
unsigned long flags;
local_irq_save(flags);
/*
* Disable timer 0.
*/
__raw_writel(0x02, TIMERS_VIRT_BASE + TMR_CER);
/*
* Clear and enable timer match 0 interrupt.
*/
__raw_writel(0x01, TIMERS_VIRT_BASE + TMR_ICR(0));
__raw_writel(0x01, TIMERS_VIRT_BASE + TMR_IER(0));
/*
* Setup new clockevent timer value.
*/
__raw_writel(delta - 1, TIMERS_VIRT_BASE + TMR_TN_MM(0, 0));
/*
* Enable timer 0.
*/
__raw_writel(0x03, TIMERS_VIRT_BASE + TMR_CER);
local_irq_restore(flags);
return 0;
}
static void timer_set_mode(enum clock_event_mode mode,
struct clock_event_device *dev)
{
unsigned long flags;
local_irq_save(flags);
switch (mode) {
case CLOCK_EVT_MODE_ONESHOT:
case CLOCK_EVT_MODE_UNUSED:
case CLOCK_EVT_MODE_SHUTDOWN:
/* disable the matching interrupt */
__raw_writel(0x00, TIMERS_VIRT_BASE + TMR_IER(0));
break;
case CLOCK_EVT_MODE_RESUME:
case CLOCK_EVT_MODE_PERIODIC:
break;
}
local_irq_restore(flags);
}
static struct clock_event_device ckevt = {
.name = "clockevent",
.features = CLOCK_EVT_FEAT_ONESHOT,
.shift = 32,
.rating = 200,
.set_next_event = timer_set_next_event,
.set_mode = timer_set_mode,
};
static cycle_t clksrc_read(struct clocksource *cs)
{
return timer_read();
}
static struct clocksource cksrc = {
.name = "clocksource",
.rating = 200,
.read = clksrc_read,
.mask = CLOCKSOURCE_MASK(32),
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
static void __init timer_config(void)
{
uint32_t ccr = __raw_readl(TIMERS_VIRT_BASE + TMR_CCR);
__raw_writel(0x0, TIMERS_VIRT_BASE + TMR_CER); /* disable */
ccr &= (cpu_is_mmp2()) ? (TMR_CCR_CS_0(0) | TMR_CCR_CS_1(0)) :
(TMR_CCR_CS_0(3) | TMR_CCR_CS_1(3));
__raw_writel(ccr, TIMERS_VIRT_BASE + TMR_CCR);
/* set timer 0 to periodic mode, and timer 1 to free-running mode */
__raw_writel(0x2, TIMERS_VIRT_BASE + TMR_CMR);
__raw_writel(0x1, TIMERS_VIRT_BASE + TMR_PLCR(0)); /* periodic */
__raw_writel(0x7, TIMERS_VIRT_BASE + TMR_ICR(0)); /* clear status */
__raw_writel(0x0, TIMERS_VIRT_BASE + TMR_IER(0));
__raw_writel(0x0, TIMERS_VIRT_BASE + TMR_PLCR(1)); /* free-running */
__raw_writel(0x7, TIMERS_VIRT_BASE + TMR_ICR(1)); /* clear status */
__raw_writel(0x0, TIMERS_VIRT_BASE + TMR_IER(1));
/* enable timer 1 counter */
__raw_writel(0x2, TIMERS_VIRT_BASE + TMR_CER);
}
static struct irqaction timer_irq = {
.name = "timer",
.flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
.handler = timer_interrupt,
.dev_id = &ckevt,
};
void __init timer_init(int irq)
{
timer_config();
setup_sched_clock(mmp_read_sched_clock, 32, CLOCK_TICK_RATE);
ckevt.mult = div_sc(CLOCK_TICK_RATE, NSEC_PER_SEC, ckevt.shift);
ckevt.max_delta_ns = clockevent_delta2ns(MAX_DELTA, &ckevt);
ckevt.min_delta_ns = clockevent_delta2ns(MIN_DELTA, &ckevt);
ckevt.cpumask = cpumask_of(0);
setup_irq(irq, &timer_irq);
clocksource_register_hz(&cksrc, CLOCK_TICK_RATE);
clockevents_register_device(&ckevt);
}
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