Initial commit. Unusable Marlin 2.0.5.3 core without any custimization.

Marlin/src/HAL/LINUX/hardware/Timer.h

@@ -0,0 +1,76 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2020 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;
+};