#include "gd32f4xx.h"
#include "systick.h"

SysTickTimer &SysTickTimer::instance()
{
    static SysTickTimer timer;
    return timer;
}

RetCode SysTickTimer::config()
{
    uint32_t clock_freq = SystemCoreClock;

    SysTick->CTRL = 0;

    if (clock_freq / 1000U > 0xFFFFFFU)
    {
        SysTick->LOAD = 0xFFFFFFU;
    }
    else
    {
        SysTick->LOAD = (clock_freq / 1000U) - 1;
    }

    SysTick->VAL = 0;

    SysTick->CTRL = SysTick_CTRL_CLKSOURCE_Msk |
                    SysTick_CTRL_TICKINT_Msk |
                    SysTick_CTRL_ENABLE_Msk;

    NVIC_SetPriority(SysTick_IRQn, 0x80U);

    return RET_OK;
}

void SysTickTimer::delay_ms(uint32_t count)
{
    delay_ = count;

    while (0U != delay_)
    {
    }
}

void SysTickTimer::decrement()
{
    if (0U != delay_)
    {
        delay_--;
    }
}

void systick_config(void)
{
    SysTickTimer::instance().config();
}

void delay_1ms(uint32_t count)
{
    SysTickTimer::instance().delay_ms(count);
}

void delay_decrement(void)
{
    SysTickTimer::instance().decrement();
}