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/*
* Copyright (C) 2011 Antony Pavlov <antonynpavlov@gmail.com>
*
* This file is part of barebox.
* 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 version 2
* as published by the Free Software Foundation.
*
* 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.
*
*/
/**
* @file
* @brief Clocksource based on MIPS CP0 timer
*/
#include <init.h>
#include <of.h>
#include <linux/clk.h>
#include <clock.h>
#include <io.h>
#include <asm/mipsregs.h>
static uint64_t c0_hpt_read(void)
{
return read_c0_count();
}
static struct clocksource cs = {
.read = c0_hpt_read,
.mask = CLOCKSOURCE_MASK(32),
};
static int clocksource_init(void)
{
unsigned int mips_hpt_frequency;
struct device_node *np;
struct clk *clk;
/* default rate: 100 MHz */
mips_hpt_frequency = 100000000;
if (IS_ENABLED(CONFIG_OFTREE)) {
np = of_get_cpu_node(0, NULL);
if (np) {
clk = of_clk_get(np, 0);
if (!IS_ERR(clk)) {
mips_hpt_frequency = clk_get_rate(clk) / 2;
}
}
}
clocks_calc_mult_shift(&cs.mult, &cs.shift,
mips_hpt_frequency, NSEC_PER_SEC, 10);
return init_clock(&cs);
}
postcore_initcall(clocksource_init);
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