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/*
* arch/metag/kernel/clock.c
*
* Copyright (C) 2012 Imagination Technologies Ltd.
*
* 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.
*/
#include <linux/delay.h>
#include <linux/io.h>
#include <asm/param.h>
#include <asm/clock.h>
struct meta_clock_desc _meta_clock;
/* Default machine get_core_freq callback. */
static unsigned long get_core_freq_default(void)
{
#ifdef CONFIG_METAG_META21
/*
* Meta 2 cores divide down the core clock for the Meta timers, so we
* can estimate the core clock from the divider.
*/
return (metag_in32(EXPAND_TIMER_DIV) + 1) * 1000000;
#else
/*
* On Meta 1 we don't know the core clock, but assuming the Meta timer
* is correct it can be estimated based on loops_per_jiffy.
*/
return (loops_per_jiffy * HZ * 5) >> 1;
#endif
}
/**
* setup_meta_clocks() - Set up the Meta clock.
* @desc: Clock descriptor usually provided by machine description
*
* Ensures all callbacks are valid.
*/
void __init setup_meta_clocks(struct meta_clock_desc *desc)
{
/* copy callbacks */
if (desc)
_meta_clock = *desc;
/* set fallback functions */
if (!_meta_clock.get_core_freq)
_meta_clock.get_core_freq = get_core_freq_default;
}
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