/******************************************************************************
 * The MIT License
 *
 * Copyright (c) 2010 Michael Hope.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *****************************************************************************/

/**
 * @file iwdg.c
 * @brief Independent watchdog (IWDG) support
 */

#include "iwdg.h"

/**
 * @brief Initialise and start the watchdog
 *
 * The prescaler and reload set the timeout.  For example, a prescaler
 * of IWDG_PRE_32 divides the 40 kHz clock by 32 and gives roughly 1
 * ms per reload.
 *
 * @param prescaler Prescaler for the 40 kHz IWDG clock.
 * @param reload Independent watchdog counter reload value.
 */
void iwdg_init(iwdg_prescaler prescaler, uint16 reload) {
   IWDG_BASE->KR = IWDG_KR_UNLOCK;
   IWDG_BASE->PR = prescaler;
   IWDG_BASE->RLR = reload;

   /* Start things off */
   IWDG_BASE->KR = IWDG_KR_START;
   iwdg_feed();
}

/**
 * @brief Reset the IWDG counter.
 *
 * Calling this function will cause the IWDG counter to be reset to
 * its reload value.
 */
void iwdg_feed(void) {
    IWDG_BASE->KR = IWDG_KR_FEED;
}
