text: /**
   * Copyright (c) 2017 - 2018, Nordic Semiconductor ASA
   * 
   * All rights reserved.
   * 
   * Redistribution and use in source and binary forms, with or without modification,
   * are permitted provided that the following conditions are met:
   * 
   * 1. Redistributions of source code must retain the above copyright notice, this
   *    list of conditions and the following disclaimer.
   * 
   * 2. Redistributions in binary form, except as embedded into a Nordic
   *    Semiconductor ASA integrated circuit in a product or a software update for
   *    such product, must reproduce the above copyright notice, this list of
   *    conditions and the following disclaimer in the documentation and/or other
   *    materials provided with the distribution.
   * 
   * 3. Neither the name of Nordic Semiconductor ASA nor the names of its
   *    contributors may be used to endorse or promote products derived from this
   *    software without specific prior written permission.
   * 
   * 4. This software, with or without modification, must only be used with a
   *    Nordic Semiconductor ASA integrated circuit.
   * 
   * 5. Any software provided in binary form under this license must not be reverse
   *    engineered, decompiled, modified and/or disassembled.
   * 
   * THIS SOFTWARE IS PROVIDED BY NORDIC SEMICONDUCTOR ASA "AS IS" AND ANY EXPRESS
   * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   * OF MERCHANTABILITY, NONINFRINGEMENT, AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED. IN NO EVENT SHALL NORDIC SEMICONDUCTOR ASA OR CONTRIBUTORS BE
   * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
   * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
   * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   * 
   */
  #include "nrf_bootloader_wdt.h"
  #include "nrf_wdt.h"
  #include "nrf_bootloader_dfu_timers.h"
  #include "nrf_log_ctrl.h"
  
  #define NRF_LOG_MODULE_NAME nrf_bootloader_wdt
  #include "nrf_log.h"
  NRF_LOG_MODULE_REGISTER();
  
  //Flag used to determine if internal feeding should stay active.
  static bool m_wdt_keep_internal_feed;
  
  static void wdt_feed(void)
  {
      if (nrf_wdt_started())
      {
          for (nrf_wdt_rr_register_t i = NRF_WDT_RR0; i < NRF_WDT_RR7; i++)
          {
              if (nrf_wdt_reload_request_is_enabled(i))
              {
                  nrf_wdt_reload_request_set(i);
              }
          }
      }
  }
  
  
  static void wdt_feed_timer_handler(void)
  {
      if (m_wdt_keep_internal_feed)
      {
          NRF_LOG_INFO("Internal feed");
          wdt_feed();
      }
  }
  
  
  void WDT_IRQHandler(void)
  {
      nrf_wdt_event_clear(NRF_WDT_EVENT_TIMEOUT);
      NRF_LOG_FINAL_FLUSH();
  }
  
  void nrf_bootloader_wdt_init(void)
  {
      static bool initialized = false;
  
      if (initialized)
      {
          return;
      }
  
      if (nrf_wdt_started())
      {
          uint32_t approx_wdt_ms = nrf_wdt_reload_value_get() / 32;
  
          NRF_LOG_INFO("WDT enabled CRV:%d ms", approx_wdt_ms);
  
          //wdt_ticks must be reduced (0.75) to feed the watchdog before the timeout.
          uint32_t reduced_timeout_ms = (approx_wdt_ms * 3)/4;
  
          /* Ideally, watchdog should be fed by the bootloader from the main context but if bootloader latency
           * (mainly driven by signature check) is big enough there is a risk that watchdog will not be fed
           * on time. In that case watchdog will be fed from timer context. */
          m_wdt_keep_internal_feed =
              (reduced_timeout_ms < NRF_BL_WDT_MAX_SCHEDULER_LATENCY_MS);
  
          /* initial watchdog feed */
          wdt_feed();
  
          /* If internal feed is needed or WDT is active in sleep module must provide regular wakeup interrupt.*/
          bool wdt_start_timer = m_wdt_keep_internal_feed || (NRF_WDT->CONFIG & WDT_CONFIG_SLEEP_Msk);
          if (wdt_start_timer)
          {
              NRF_LOG_INFO("Starting a timer (%d ms) for feeding watchdog.", reduced_timeout_ms);
              nrf_bootloader_wdt_feed_timer_start(reduced_timeout_ms, wdt_feed_timer_handler);
          }
  
          NVIC_EnableIRQ(WDT_IRQn);
      }
      else
      {
          NRF_LOG_INFO("WDT is not enabled");
      }
  
      initialized = true;
  }
  
  void nrf_bootloader_wdt_feed(void)
  {
      if (nrf_wdt_started())
      {
          wdt_feed();
      }
  }
  