SlowTicker: integer math only in interrupt context

[clinton/Smoothieware.git] / src / libs / SlowTicker.cpp

/*
      This file is part of Smoothie (http://smoothieware.org/). The motion control part is heavily based on Grbl (https://github.com/simen/grbl).
      Smoothie is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
      Smoothie is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
      You should have received a copy of the GNU General Public License along with Smoothie. If not, see <http://www.gnu.org/licenses/>.
*/

using namespace std;
#include <vector>
#include "libs/nuts_bolts.h"
#include "libs/Module.h"
#include "libs/Kernel.h"
#include "SlowTicker.h"
#include "libs/Hook.h"

#include <mri.h>

SlowTicker* global_slow_ticker;

SlowTicker::SlowTicker(){
    this->max_frequency = 0;
    global_slow_ticker = this;
    LPC_SC->PCONP |= (1 << 22);     // Power Ticker ON
    LPC_TIM2->MR0 = 10000;        // Initial dummy value for Match Register
    LPC_TIM2->MCR = 3;              // Match on MR0, reset on MR0
    LPC_TIM2->TCR = 1;              // Enable interrupt
    NVIC_EnableIRQ(TIMER2_IRQn);    // Enable interrupt handler

    ispbtn.from_string("2.10")->as_input()->pull_up();
}

void SlowTicker::set_frequency( int frequency ){
    this->interval = int(floor((SystemCoreClock/4)/frequency));   // SystemCoreClock/4 = Timer increments in a second
    LPC_TIM2->MR0 = this->interval;
    LPC_TIM2->TCR = 3;  // Reset
    LPC_TIM2->TCR = 1;  // Reset
}

void SlowTicker::tick(){

    LPC_GPIO1->FIODIR |= 1<<20;
    LPC_GPIO1->FIOSET = 1<<20;

    for (unsigned int i=0; i<this->hooks.size(); i++){
        Hook* hook = this->hooks.at(i);
        hook->countdown -= this->interval;
        if (hook->countdown < 0)
        {
            hook->countdown += hook->interval;
            hook->call();
        }
    }

    LPC_GPIO1->FIOCLR = 1<<20;

    if (ispbtn.get() == 0)
        __debugbreak();
}

extern "C" void TIMER2_IRQHandler (void){
    if((LPC_TIM2->IR >> 0) & 1){  // If interrupt register set for MR0
        LPC_TIM2->IR |= 1 << 0;   // Reset it
    }
    global_slow_ticker->tick();
}