src/ar100/timer.c


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// Timer functions for ar100
//
// Copyright (C) 2020-2021  Elias Bakken <elias@iagent.no>
//
// This file may be distributed under the terms of the GNU GPLv3 license.

#include "timer.h"
#include "board/timer_irq.h"
#include "board/misc.h"

volatile static uint32_t timer_compare;
static uint8_t interrupt_seen;

uint8_t timer_interrupt_pending(void){
    if(interrupt_seen){
      return 0;
    }
    if(timer_is_before(mfspr(SPR_TICK_TTCR_ADDR), timer_compare)){
      return 0;
    }

    return 1;
}
void timer_clear_interrupt(void){
    interrupt_seen = 1;
}
// Set the next timer wake up time
void timer_set(uint32_t value){
    timer_compare = value;
    interrupt_seen = 0;
}

// Return the current time (in absolute clock ticks).
uint32_t timer_read_time(void){
    return mfspr(SPR_TICK_TTCR_ADDR);
}

void timer_reset(void){
    mtspr(SPR_TICK_TTCR_ADDR, 0);
}

// Activate timer dispatch as soon as possible
void timer_kick(void){
    timer_set(timer_read_time() + 50);
}

void timer_init(void){
    interrupt_seen = 1;
    mtspr(SPR_TICK_TTMR_ADDR, 3<<30); // continous
    timer_kick();
}
DECL_INIT(timer_init);