#include <stdint.h>
#include <stdbool.h>

#include "driverlib/sysctl.h"
#include "driverlib/gpio.h"
#include "driverlib/timer.h"
#include "driverlib/pin_map.h"
#include "inc/tm4c1294ncpdt.h"
#include "driverlib/interrupt.h"
#include "inc/hw_types.h"
#include "inc/hw_memmap.h"

#include "frequency.h"


void start_frequency_scan() {
    // config GPIO PD0 as timer input T0CCP0 at BoosterPack Connector #1 pin 14
    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOD);
    GPIOPinTypeTimer(GPIO_PORTD_BASE, GPIO_PIN_0);
    GPIOPinConfigure(GPIO_PD0_T0CCP0);
    SysCtlPeripheralEnable(SYSCTL_PERIPH_TIMER0);
    TimerDisable(TIMER0_BASE, TIMER_BOTH);
    TimerConfigure(TIMER0_BASE, TIMER_CFG_SPLIT_PAIR | TIMER_CFG_A_CAP_TIME_UP);
    TimerControlEvent(TIMER0_BASE, TIMER_A, TIMER_EVENT_POS_EDGE);
    // use maximum load value
    TimerLoadSet(TIMER0_BASE, TIMER_A, 0xffff);
    // use maximum prescale value
    TimerPrescaleSet(TIMER0_BASE, TIMER_A, 0xff);
    TimerIntEnable(TIMER0_BASE, TIMER_CAPA_EVENT);
    TimerEnable(TIMER0_BASE, TIMER_A);
}

uint32_t previous;
void capture_handler() {
    TimerIntClear(TIMER0_BASE, TIMER_CAPA_EVENT);

    uint32_t current = TimerValueGet(TIMER0_BASE, TIMER_A);

    uint32_t delta = current - previous;
    gPeriod = delta;

    previous = current;
}