synth/arm/timer.h

#pragma once

struct TimerControl {
    union {
        struct {
            uint32_t MDT0 : 1;
            uint32_t UDT0 : 1;
            uint32_t GENT0 : 1;
            uint32_t CAPT0 : 1;
            uint32_t ARHT0 : 1;
            uint32_t LOAD0 : 1;
            uint32_t ENIT0 : 1;
            uint32_t ENT0 : 1;
            uint32_t T0INT : 1;
            uint32_t PWMA0 : 1;
            uint32_t ENALL : 1;
            uint32_t CASC : 1;

            uint32_t reserved : 20;
        };
        uint32_t raw;
    };
};

struct Timer {
    volatile TimerControl TCSR0;
    volatile uint32_t TLR0;
    volatile uint32_t TCR0;

    uint32_t _reserved;

    volatile TimerControl TCSR1;
    volatile uint32_t TLR1;
    volatile uint32_t TCR1;

    void EnableT1() {
        TCSR1.ARHT0 = 1;
        TCSR1.ENT0 = 1;
    }

    uint32_t GetT1Ticks() { return TCR1; }

    void SetupAsWdt(uint32_t timeout_ticks) {
        TLR0 = timeout_ticks;
        TCSR0.LOAD0 = 1;  // reset counter
        TCSR0.UDT0 = 1;   // count backwards from the load value
        TCSR0.ENIT0 = 1;  // enable interrupt

        TCSR0.LOAD0 = 0;  // allow counter to run
        TCSR0.ENT0 = 1;   // enable timer
    }

    void Pet() {
        TCSR0.ENT0 = 0;
        TCSR0.LOAD0 = 1;
        TCSR0.LOAD0 = 0;
        TCSR0.ENT0 = 1;
    }
};

#define timer0 ((Timer*)0x40002000)