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/*
* Copyright (C) 2004-2006 Atmel Corporation
*
* See file CREDITS for list of people who contributed to this
* project.
*
* 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 <common.h>
#include <div64.h>
#include <asm/errno.h>
#include <asm/io.h>
#include <asm/processor.h>
#include <asm/sysreg.h>
#include <asm/arch/hardware.h>
#define HANDLER_MASK 0x00ffffff
#define INTLEV_SHIFT 30
#define INTLEV_MASK 0x00000003
DECLARE_GLOBAL_DATA_PTR;
/* Incremented whenever COUNT reaches 0xffffffff by timer_interrupt_handler */
volatile unsigned long timer_overflow;
/*
* Instead of dividing by get_tbclk(), multiply by this constant and
* right-shift the result by 32 bits.
*/
static unsigned long tb_factor;
unsigned long get_tbclk(void)
{
return gd->cpu_hz;
}
unsigned long long get_ticks(void)
{
unsigned long lo, hi_now, hi_prev;
do {
hi_prev = timer_overflow;
lo = sysreg_read(COUNT);
hi_now = timer_overflow;
} while (hi_prev != hi_now);
return ((unsigned long long)hi_now << 32) | lo;
}
unsigned long get_timer(unsigned long base)
{
u64 now = get_ticks();
now *= tb_factor;
return (unsigned long)(now >> 32) - base;
}
/*
* For short delays only. It will overflow after a few seconds.
*/
void __udelay(unsigned long usec)
{
unsigned long cycles;
unsigned long base;
unsigned long now;
base = sysreg_read(COUNT);
cycles = ((usec * (get_tbclk() / 10000)) + 50) / 100;
do {
now = sysreg_read(COUNT);
} while ((now - base) < cycles);
}
static int set_interrupt_handler(unsigned int nr, void (*handler)(void),
unsigned int priority)
{
extern void _evba(void);
unsigned long intpr;
unsigned long handler_addr = (unsigned long)handler;
handler_addr -= (unsigned long)&_evba;
if ((handler_addr & HANDLER_MASK) != handler_addr
|| (priority & INTLEV_MASK) != priority)
return -EINVAL;
intpr = (handler_addr & HANDLER_MASK);
intpr |= (priority & INTLEV_MASK) << INTLEV_SHIFT;
writel(intpr, (void *)ATMEL_BASE_INTC + 4 * nr);
return 0;
}
int timer_init(void)
{
extern void timer_interrupt_handler(void);
u64 tmp;
sysreg_write(COUNT, 0);
tmp = (u64)CONFIG_SYS_HZ << 32;
tmp += gd->cpu_hz / 2;
do_div(tmp, gd->cpu_hz);
tb_factor = (u32)tmp;
if (set_interrupt_handler(0, &timer_interrupt_handler, 3))
return -EINVAL;
/* For all practical purposes, this gives us an overflow interrupt */
sysreg_write(COMPARE, 0xffffffff);
return 0;
}
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