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#include "arm_arch.h"
#include "lib/systick.h"
#include <nvic.h>

uint8_t systick_get_countflag(void)
{
	return (getreg32(NVIC_SYSTICK_CTRL) & NVIC_SYSTICK_CTRL_COUNTFLAG) ? 1 : 0;
}

// See 2.2.3 SysTick external clock is not HCLK/8
uint32_t g_divisor = 1;
void systick_set_reload(uint32_t value)
{
	putreg32((((value * g_divisor) << NVIC_SYSTICK_RELOAD_SHIFT) & NVIC_SYSTICK_RELOAD_MASK), NVIC_SYSTICK_RELOAD);
}


void systick_set_clocksource(uint8_t clocksource)
{
	g_divisor = (clocksource == CLKSOURCE_EXTERNAL) ? 8 : 1;
	modifyreg32(NVIC_SYSTICK_CTRL, NVIC_SYSTICK_CTRL_CLKSOURCE, clocksource & NVIC_SYSTICK_CTRL_CLKSOURCE);
}

void systick_counter_enable(void)
{
	modifyreg32(NVIC_SYSTICK_CTRL, 0, NVIC_SYSTICK_CTRL_ENABLE);
}

void systick_counter_disable(void)
{
	modifyreg32(NVIC_SYSTICK_CTRL, NVIC_SYSTICK_CTRL_ENABLE, 0);
	putreg32(0, NVIC_SYSTICK_CURRENT);
}

void systick_interrupt_enable(void)
{
	modifyreg32(NVIC_SYSTICK_CTRL, 0, NVIC_SYSTICK_CTRL_TICKINT);
}

void systick_interrupt_disable(void)
{
	modifyreg32(NVIC_SYSTICK_CTRL, NVIC_SYSTICK_CTRL_TICKINT, 0);
}
