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/*
* arch/arm/mach-at91/at91x40_time.c
*
* (C) Copyright 2007, Greg Ungerer <gerg@snapgear.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.
*
* 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/kernel.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/time.h>
#include <linux/io.h>
#include <mach/hardware.h>
#include <asm/mach/time.h>
#include <mach/at91_tc.h>
#define at91_tc_read(field) \
__raw_readl(AT91_IO_P2V(AT91_TC) + field)
#define at91_tc_write(field, value) \
__raw_writel(value, AT91_IO_P2V(AT91_TC) + field);
/*
* 3 counter/timer units present.
*/
#define AT91_TC_CLK0BASE 0
#define AT91_TC_CLK1BASE 0x40
#define AT91_TC_CLK2BASE 0x80
static unsigned long at91x40_gettimeoffset(void)
{
return (at91_tc_read(AT91_TC_CLK1BASE + AT91_TC_CV) * 1000000 / (AT91X40_MASTER_CLOCK / 128));
}
static irqreturn_t at91x40_timer_interrupt(int irq, void *dev_id)
{
at91_tc_read(AT91_TC_CLK1BASE + AT91_TC_SR);
timer_tick();
return IRQ_HANDLED;
}
static struct irqaction at91x40_timer_irq = {
.name = "at91_tick",
.flags = IRQF_DISABLED | IRQF_TIMER,
.handler = at91x40_timer_interrupt
};
void __init at91x40_timer_init(void)
{
unsigned int v;
at91_tc_write(AT91_TC_BCR, 0);
v = at91_tc_read(AT91_TC_BMR);
v = (v & ~AT91_TC_TC1XC1S) | AT91_TC_TC1XC1S_NONE;
at91_tc_write(AT91_TC_BMR, v);
at91_tc_write(AT91_TC_CLK1BASE + AT91_TC_CCR, AT91_TC_CLKDIS);
at91_tc_write(AT91_TC_CLK1BASE + AT91_TC_CMR, (AT91_TC_TIMER_CLOCK4 | AT91_TC_CPCTRG));
at91_tc_write(AT91_TC_CLK1BASE + AT91_TC_IDR, 0xffffffff);
at91_tc_write(AT91_TC_CLK1BASE + AT91_TC_RC, (AT91X40_MASTER_CLOCK / 128) / HZ - 1);
at91_tc_write(AT91_TC_CLK1BASE + AT91_TC_IER, (1<<4));
setup_irq(AT91X40_ID_TC1, &at91x40_timer_irq);
at91_tc_write(AT91_TC_CLK1BASE + AT91_TC_CCR, (AT91_TC_SWTRG | AT91_TC_CLKEN));
}
struct sys_timer at91x40_timer = {
.init = at91x40_timer_init,
.offset = at91x40_gettimeoffset,
};
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