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/*
* This file is part of the coreboot project.
*
* Copyright 2015 Google Inc.
*
* 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; version 2 of the License.
*
* 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.
*/
#include <arch/io.h>
#include <timer.h>
#include <delay.h>
#define TIMER_CTRL_REG 0xf1020300
#define TIMER_RELOAD_REG 0xf1020310
#define TIMER_REG 0xf1020314
#define TIMER_RELOAD_VALUE 0xffffffff
#define MHZ_NUM 25
void init_timer(void)
{
unsigned int reg;
/* Set the reload timer */
write32((void *)TIMER_RELOAD_REG, TIMER_RELOAD_VALUE);
/* Set the initial value to TIMER_RELOAD_VALUE - 1
* (instead of TIMER_RELOAD_VALUE) to avoid 'fake'
* overflow being detected in timer_monotonic_get
* if it's called close enough with 'this' function */
write32((void *)TIMER_REG, TIMER_RELOAD_VALUE - 1);
reg = read32((const void *)TIMER_CTRL_REG);
/* Let it start counting */
reg |= 0x3;
write32((void *)TIMER_CTRL_REG, reg);
}
void timer_monotonic_get(struct mono_time *mt)
{
static uint64_t total_ticks = 0;
uint64_t overflow = 0;
uint32_t current_ticks =
TIMER_RELOAD_VALUE - read32((const void *)TIMER_REG);
/* Assuming at most one overflow happened since last call */
if (current_ticks <= total_ticks)
overflow = 1ULL << 32;
total_ticks = (((total_ticks + overflow) >> 32) << 32) + current_ticks;
mono_time_set_usecs(mt, total_ticks / MHZ_NUM);
}
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