Firmware2/Marlin/src/HAL/SAMD51/watchdog.cpp

/**
 * Marlin 3D Printer Firmware
 *
 * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
 * SAMD51 HAL developed by Giuliano Zaro (AKA GMagician)
 *
 * 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/>.
 *
 */

#ifdef __SAMD51__

#include "../../inc/MarlinConfig.h"

#if ENABLED(USE_WATCHDOG)

  #include "watchdog.h"

  void watchdog_init() {
    // The low-power oscillator used by the WDT runs at 32,768 Hz with
    // a 1:32 prescale, thus 1024 Hz, though probably not super precise.

    // Setup WDT clocks
    MCLK->APBAMASK.bit.OSC32KCTRL_ = true;
    MCLK->APBAMASK.bit.WDT_ = true;
    OSC32KCTRL->OSCULP32K.bit.EN1K = true;      // Enable out 1K (this is what WDT uses)

    WDT->CTRLA.bit.ENABLE = false;              // Disable watchdog for config
    SYNC(WDT->SYNCBUSY.bit.ENABLE);

    WDT->INTENCLR.reg = WDT_INTENCLR_EW;        // Disable early warning interrupt
    WDT->CONFIG.reg = WDT_CONFIG_PER_CYC4096;   // Set at least 4s period for chip reset

    HAL_watchdog_refresh();

    WDT->CTRLA.reg = WDT_CTRLA_ENABLE;          // Start watchdog now in normal mode
    SYNC(WDT->SYNCBUSY.bit.ENABLE);
  }

#endif // USE_WATCHDOG

#endif // __SAMD51__