Firmware2/Marlin/src/HAL/HAL_LINUX/hardware/Timer.h
2019-06-27 23:58:16 -05:00

77 lines
2.3 KiB
C++

/**
* Marlin 3D Printer Firmware
* Copyright (c) 2019 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
*
* Based on Sprinter and grbl.
* Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
*
* This program 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.
*
* This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
#pragma once
#include <stdint.h>
#include <stdlib.h>
#include <unistd.h>
#include <signal.h>
#include <time.h>
#include <stdio.h>
#include "Clock.h"
class Timer {
public:
Timer();
virtual ~Timer();
typedef void (callback_fn)();
void init(uint32_t sig_id, uint32_t sim_freq, callback_fn* fn);
void start(uint32_t frequency);
void enable();
bool enabled() {return active;}
void disable();
void setCompare(uint32_t compare);
uint32_t getCount();
uint32_t getCompare() {return compare;}
uint32_t getOverruns() {return overruns;}
uint32_t getAvgError() {return avg_error;}
intptr_t getID() {
return (*(intptr_t*)timerid);
}
static void handler(int sig, siginfo_t *si, void *uc){
Timer* _this = (Timer*)si->si_value.sival_ptr;
_this->avg_error += (Clock::nanos() - _this->start_time) - _this->period; //high_resolution_clock is also limited in precision, but best we have
_this->avg_error /= 2; //very crude precision analysis (actually within +-500ns usually)
_this->start_time = Clock::nanos(); // wrap
_this->cbfn();
_this->overruns += timer_getoverrun(_this->timerid); // even at 50Khz this doesn't stay zero, again demonstrating the limitations
// using a realtime linux kernel would help somewhat
}
private:
bool active;
uint32_t compare;
uint32_t frequency;
uint32_t overruns;
timer_t timerid;
sigset_t mask;
callback_fn* cbfn;
uint64_t period;
uint64_t avg_error;
uint64_t start_time;
};