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/*
* TCC8000 system timer setup
*
* (C) 2009 Hans J. Koch <hjk@linutronix.de>
*
* Licensed under the terms of the GPL version 2.
*
*/
#include <linux/clk.h>
#include <linux/clockchips.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/kernel.h>
#include <linux/spinlock.h>
#include <asm/mach/time.h>
#include <mach/tcc8k-regs.h>
#include <mach/irqs.h>
#include "common.h"
static void __iomem *timer_base;
static cycle_t tcc_get_cycles(struct clocksource *cs)
{
return __raw_readl(timer_base + TC32MCNT_OFFS);
}
static struct clocksource clocksource_tcc = {
.name = "tcc_tc32",
.rating = 200,
.read = tcc_get_cycles,
.mask = CLOCKSOURCE_MASK(32),
.shift = 28,
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
static int tcc_set_next_event(unsigned long evt,
struct clock_event_device *unused)
{
unsigned long reg = __raw_readl(timer_base + TC32MCNT_OFFS);
__raw_writel(reg + evt, timer_base + TC32CMP0_OFFS);
return 0;
}
static void tcc_set_mode(enum clock_event_mode mode,
struct clock_event_device *evt)
{
unsigned long tc32irq;
switch (mode) {
case CLOCK_EVT_MODE_ONESHOT:
tc32irq = __raw_readl(timer_base + TC32IRQ_OFFS);
tc32irq |= TC32IRQ_IRQEN0;
__raw_writel(tc32irq, timer_base + TC32IRQ_OFFS);
break;
case CLOCK_EVT_MODE_SHUTDOWN:
case CLOCK_EVT_MODE_UNUSED:
tc32irq = __raw_readl(timer_base + TC32IRQ_OFFS);
tc32irq &= ~TC32IRQ_IRQEN0;
__raw_writel(tc32irq, timer_base + TC32IRQ_OFFS);
break;
case CLOCK_EVT_MODE_PERIODIC:
case CLOCK_EVT_MODE_RESUME:
break;
}
}
static irqreturn_t tcc8k_timer_interrupt(int irq, void *dev_id)
{
struct clock_event_device *evt = dev_id;
/* Acknowledge TC32 interrupt by reading TC32IRQ */
__raw_readl(timer_base + TC32IRQ_OFFS);
evt->event_handler(evt);
return IRQ_HANDLED;
}
static struct clock_event_device clockevent_tcc = {
.name = "tcc_timer1",
.features = CLOCK_EVT_FEAT_ONESHOT,
.shift = 32,
.set_mode = tcc_set_mode,
.set_next_event = tcc_set_next_event,
.rating = 200,
};
static struct irqaction tcc8k_timer_irq = {
.name = "TC32_timer",
.flags = IRQF_DISABLED | IRQF_TIMER,
.handler = tcc8k_timer_interrupt,
.dev_id = &clockevent_tcc,
};
static int __init tcc_clockevent_init(struct clk *clock)
{
unsigned int c = clk_get_rate(clock);
clocksource_tcc.mult = clocksource_hz2mult(c,
clocksource_tcc.shift);
clocksource_register(&clocksource_tcc);
clockevent_tcc.mult = div_sc(c, NSEC_PER_SEC,
clockevent_tcc.shift);
clockevent_tcc.max_delta_ns =
clockevent_delta2ns(0xfffffffe, &clockevent_tcc);
clockevent_tcc.min_delta_ns =
clockevent_delta2ns(0xff, &clockevent_tcc);
clockevent_tcc.cpumask = cpumask_of(0);
clockevents_register_device(&clockevent_tcc);
return 0;
}
void __init tcc8k_timer_init(struct clk *clock, void __iomem *base, int irq)
{
u32 reg;
timer_base = base;
tcc8k_timer_irq.irq = irq;
/* Enable clocks */
clk_enable(clock);
/* Initialize 32-bit timer */
reg = __raw_readl(timer_base + TC32EN_OFFS);
reg &= ~TC32EN_ENABLE; /* Disable timer */
__raw_writel(reg, timer_base + TC32EN_OFFS);
/* Free running timer, counting from 0 to 0xffffffff */
__raw_writel(0, timer_base + TC32EN_OFFS);
__raw_writel(0, timer_base + TC32LDV_OFFS);
reg = __raw_readl(timer_base + TC32IRQ_OFFS);
reg |= TC32IRQ_IRQEN0; /* irq at match with CMP0 */
__raw_writel(reg, timer_base + TC32IRQ_OFFS);
__raw_writel(TC32EN_ENABLE, timer_base + TC32EN_OFFS);
tcc_clockevent_init(clock);
setup_irq(irq, &tcc8k_timer_irq);
}
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