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/*
* This file is part of the coreboot project.
*
* Copyright 2014 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/cpu.h>
#include <device/mmio.h>
#include <soc/cpu.h>
#include <stdint.h>
#include <timer.h>
#define PISTACHIO_CLOCK_SWITCH 0xB8144200
#define MIPS_EXTERN_PLL_BYPASS_MASK 0x00000002
static int get_count_mhz_freq(void)
{
static unsigned count_mhz_freq;
if (!count_mhz_freq) {
if (IMG_PLATFORM_ID() != IMG_PLATFORM_ID_SILICON)
count_mhz_freq = 25; /* FPGA board */
else {
/* If MIPS PLL external bypass bit is set, it means
* that the MIPS PLL is already set up to work at a
* frequency of 550 MHz; otherwise, the crystal is
* used with a frequency of 52 MHz
*/
if (read32_x(PISTACHIO_CLOCK_SWITCH) &
MIPS_EXTERN_PLL_BYPASS_MASK)
/* Half MIPS PLL freq. */
count_mhz_freq = 275;
else
/* Half Xtal freq. */
count_mhz_freq = 26;
}
}
return count_mhz_freq;
}
void timer_monotonic_get(struct mono_time *mt)
{
mono_time_set_usecs(mt, read_c0_count() / get_count_mhz_freq());
}
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