1 files changed, 70 insertions, 0 deletions
diff --git a/Marlin/src/HAL/AVR/watchdog.cpp b/Marlin/src/HAL/AVR/watchdog.cpp
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+++ b/Marlin/src/HAL/AVR/watchdog.cpp
@@ -0,0 +1,70 @@
+/**
+ * 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 <https://www.gnu.org/licenses/>.
+ *
+ */
+#ifdef __AVR__
+
+#include "../../inc/MarlinConfig.h"
+
+#if ENABLED(USE_WATCHDOG)
+
+#include "watchdog.h"
+
+#include "../../MarlinCore.h"
+
+// Initialize watchdog with 8s timeout, if possible. Otherwise, make it 4s.
+void watchdog_init() {
+  #if ENABLED(WATCHDOG_DURATION_8S) && defined(WDTO_8S)
+    #define WDTO_NS WDTO_8S
+  #else
+    #define WDTO_NS WDTO_4S
+  #endif
+  #if ENABLED(WATCHDOG_RESET_MANUAL)
+    // Enable the watchdog timer, but only for the interrupt.
+    // Take care, as this requires the correct order of operation, with interrupts disabled.
+    // See the datasheet of any AVR chip for details.
+    wdt_reset();
+    cli();
+    _WD_CONTROL_REG = _BV(_WD_CHANGE_BIT) | _BV(WDE);
+    _WD_CONTROL_REG = _BV(WDIE) | (WDTO_NS & 0x07) | ((WDTO_NS & 0x08) << 2); // WDTO_NS directly does not work. bit 0-2 are consecutive in the register but the highest value bit is at bit 5
+                                                                              // So worked for up to WDTO_2S
+    sei();
+    wdt_reset();
+  #else
+    wdt_enable(WDTO_NS); // The function handles the upper bit correct.
+  #endif
+  //delay(10000); // test it!
+}
+
+//===========================================================================
+//=================================== ISR ===================================
+//===========================================================================
+
+// Watchdog timer interrupt, called if main program blocks >4sec and manual reset is enabled.
+#if ENABLED(WATCHDOG_RESET_MANUAL)
+  ISR(WDT_vect) {
+    sei();  // With the interrupt driven serial we need to allow interrupts.
+    SERIAL_ERROR_MSG(STR_WATCHDOG_FIRED);
+    minkill();  // interrupt-safe final kill and infinite loop
+  }
+#endif
+
+#endif // USE_WATCHDOG
+#endif // __AVR__