/*
 * Copyright 2024 Google LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "drivers/watchdog.h"

#include "util/bitset.h"
#include "system/logging.h"

#define STM32F2_COMPATIBLE
#define STM32F4_COMPATIBLE
#define STM32F7_COMPATIBLE
#include <mcu.h>

#include <inttypes.h>

void watchdog_init(void) {
  IWDG_WriteAccessCmd(IWDG_WriteAccess_Enable);

  IWDG_SetPrescaler(IWDG_Prescaler_64); // ~8 seconds
  IWDG_SetReload(0xfff);

  IWDG_WriteAccessCmd(IWDG_WriteAccess_Disable);

  DBGMCU_APB1PeriphConfig(DBGMCU_IWDG_STOP, ENABLE);
}

void watchdog_start(void) {
  IWDG_Enable();
  watchdog_feed();
}

// This behaves differently from the bootloader and the firmware.
void watchdog_feed(void) {
  IWDG_ReloadCounter();
}

bool watchdog_check_reset_flag(void) {
  return RCC_GetFlagStatus(RCC_FLAG_IWDGRST) != RESET;
}

McuRebootReason watchdog_clear_reset_flag(void) {
  McuRebootReason mcu_reboot_reason = {
    .brown_out_reset = (RCC_GetFlagStatus(RCC_FLAG_BORRST) != RESET),
    .pin_reset = (RCC_GetFlagStatus(RCC_FLAG_PINRST) != RESET),
    .power_on_reset = (RCC_GetFlagStatus(RCC_FLAG_PORRST) != RESET),
    .software_reset = (RCC_GetFlagStatus(RCC_FLAG_SFTRST) != RESET),
    .independent_watchdog_reset = (RCC_GetFlagStatus(RCC_FLAG_IWDGRST) != RESET),
    .window_watchdog_reset = (RCC_GetFlagStatus(RCC_FLAG_WWDGRST) != RESET),
    .low_power_manager_reset = (RCC_GetFlagStatus(RCC_FLAG_LPWRRST) != RESET)
  };

  RCC_ClearFlag();

  return mcu_reboot_reason;
}