#include <linux/module.h>
#include <linux/cpufreq.h>
#include <clocksource/arm_arch_timer.h>

/*--- #include <asm/performance.h> ---*/
/*--- #include <linux/kernel.h> ---*/
static unsigned long long cycles_to_usec_reciprocal;

unsigned int ipq40xx_get_cyclefreq(void) {
    return (arch_timer_get_rate());
}
EXPORT_SYMBOL(ipq40xx_get_cyclefreq);

/**
 */
static int __init ipq40xx_cycle_init_reciprocal(void)
{
	unsigned long long reciprocal = 0;
	unsigned long cycle_freq = ipq40xx_get_cyclefreq();

	if (cycle_freq) {
		reciprocal = (1ULL << 32) * (unsigned long long)USEC_PER_SEC;
		do_div(reciprocal, cycle_freq);
	}
	cycles_to_usec_reciprocal = reciprocal;
	pr_debug("%s: reciprocal=%llu\n", __func__, cycles_to_usec_reciprocal);
	return 0;
}
subsys_initcall(ipq40xx_cycle_init_reciprocal);

/**
 */
unsigned long ipq40xx_cycles_to_usec(unsigned long cycle)
{


	return (((unsigned long long)cycle * cycles_to_usec_reciprocal) >> 32);
}
EXPORT_SYMBOL(ipq40xx_cycles_to_usec);

/**
 * Liest den generic timer (CNTPCT) / arch timer.
 * Wird sehr früh initialisiert und läuft stetig mit 48MHz
 */
unsigned int ipq40xx_get_cycles(void) {
    u64 timeval;
    asm volatile("MRRC p15, 0, %Q0, %R0, c14 ": "=r"(timeval));
    return (unsigned int)timeval;
}
EXPORT_SYMBOL(ipq40xx_get_cycles);