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/*
* linux/arch/arm/plat-versatile/timer-sp.c
*
* Copyright (C) 1999 - 2003 ARM Limited
* Copyright (C) 2000 Deep Blue Solutions Ltd
*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/clocksource.h>
#include <linux/clockchips.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/io.h>
#include <asm/hardware/arm_timer.h>
#include <plat/timer-sp.h>
/*
* These timers are currently always setup to be clocked at 1MHz.
*/
#define TIMER_FREQ_KHZ (1000)
#define TIMER_RELOAD (TIMER_FREQ_KHZ * 1000 / HZ)
static void __iomem *clksrc_base;
static cycle_t sp804_read(struct clocksource *cs)
{
return ~readl(clksrc_base + TIMER_VALUE);
}
static struct clocksource clocksource_sp804 = {
.name = "timer3",
.rating = 200,
.read = sp804_read,
.mask = CLOCKSOURCE_MASK(32),
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
void __init sp804_clocksource_init(void __iomem *base)
{
struct clocksource *cs = &clocksource_sp804;
clksrc_base = base;
/* setup timer 0 as free-running clocksource */
writel(0, clksrc_base + TIMER_CTRL);
writel(0xffffffff, clksrc_base + TIMER_LOAD);
writel(0xffffffff, clksrc_base + TIMER_VALUE);
writel(TIMER_CTRL_32BIT | TIMER_CTRL_ENABLE | TIMER_CTRL_PERIODIC,
clksrc_base + TIMER_CTRL);
clocksource_register_khz(cs, TIMER_FREQ_KHZ);
}
static void __iomem *clkevt_base;
/*
* IRQ handler for the timer
*/
static irqreturn_t sp804_timer_interrupt(int irq, void *dev_id)
{
struct clock_event_device *evt = dev_id;
/* clear the interrupt */
writel(1, clkevt_base + TIMER_INTCLR);
evt->event_handler(evt);
return IRQ_HANDLED;
}
static void sp804_set_mode(enum clock_event_mode mode,
struct clock_event_device *evt)
{
unsigned long ctrl = TIMER_CTRL_32BIT | TIMER_CTRL_IE;
writel(ctrl, clkevt_base + TIMER_CTRL);
switch (mode) {
case CLOCK_EVT_MODE_PERIODIC:
writel(TIMER_RELOAD, clkevt_base + TIMER_LOAD);
ctrl |= TIMER_CTRL_PERIODIC | TIMER_CTRL_ENABLE;
break;
case CLOCK_EVT_MODE_ONESHOT:
/* period set, and timer enabled in 'next_event' hook */
ctrl |= TIMER_CTRL_ONESHOT;
break;
case CLOCK_EVT_MODE_UNUSED:
case CLOCK_EVT_MODE_SHUTDOWN:
default:
break;
}
writel(ctrl, clkevt_base + TIMER_CTRL);
}
static int sp804_set_next_event(unsigned long next,
struct clock_event_device *evt)
{
unsigned long ctrl = readl(clkevt_base + TIMER_CTRL);
writel(next, clkevt_base + TIMER_LOAD);
writel(ctrl | TIMER_CTRL_ENABLE, clkevt_base + TIMER_CTRL);
return 0;
}
static struct clock_event_device sp804_clockevent = {
.name = "timer0",
.shift = 32,
.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
.set_mode = sp804_set_mode,
.set_next_event = sp804_set_next_event,
.rating = 300,
.cpumask = cpu_all_mask,
};
static struct irqaction sp804_timer_irq = {
.name = "timer",
.flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
.handler = sp804_timer_interrupt,
.dev_id = &sp804_clockevent,
};
void __init sp804_clockevents_init(void __iomem *base, unsigned int timer_irq)
{
struct clock_event_device *evt = &sp804_clockevent;
clkevt_base = base;
evt->irq = timer_irq;
evt->mult = div_sc(TIMER_FREQ_KHZ, NSEC_PER_MSEC, evt->shift);
evt->max_delta_ns = clockevent_delta2ns(0xffffffff, evt);
evt->min_delta_ns = clockevent_delta2ns(0xf, evt);
setup_irq(timer_irq, &sp804_timer_irq);
clockevents_register_device(evt);
}
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