#include <stdint.h>
#include "system.h"

static uint32_t master_clock = 0;

/* Timer 4: Use val 60000 with PSC 1400 for 1s tick (84 Mhz) */
/* Timer 4: Use val 52500 with PSC 200 for 1/8 s tick (84 Mhz) */

#define TMR4_INIT_VAL 52500
#define TMR4_INIT_PSC 200

void timer_init(void)
{
    uint32_t val = 0;
    uint32_t psc = 1;
    uint32_t err = 0;

    nvic_irq_enable(NVIC_TIM4_IRQN);
    nvic_irq_setprio(NVIC_TIM4_IRQN, 0);
    APB1_CLOCK_RST |= TIM4_APB1_CLOCK_ER_VAL;
    __asm__ volatile ("dmb");
    APB1_CLOCK_RST &= ~TIM4_APB1_CLOCK_ER_VAL;
    APB1_CLOCK_ER |= TIM4_APB1_CLOCK_ER_VAL;

    TIM4_CR1    = 0;
    __asm__ volatile ("dmb");
    TIM4_PSC    = TMR4_INIT_PSC;
    TIM4_ARR    = TMR4_INIT_VAL;
    TIM4_CR1    |= TIM_CR1_CLOCK_ENABLE;
    TIM4_DIER   |= TIM_DIER_UIE;
    __asm__ volatile ("dmb");
}

static volatile uint32_t tim4_ticks = 0;
void isr_tim1(void)
{
    TIM1_SR &= ~TIM_SR_UIF;
}

void isr_tim3(void)
{
    TIM3_SR &= ~TIM_SR_UIF;
}

void isr_tim4(void)
{
    TIM4_SR &= ~TIM_SR_UIF;
    tim4_ticks++;
}

void gettime(uint32_t *seconds, uint32_t *microseconds)
{
    *microseconds = ((TIM4_CNT * TMR4_INIT_PSC) / 84) + (tim4_ticks & 0x07) * 125000;
    *seconds = (tim4_ticks >> 3);
}