/* ---------------------------------------------------------------------------
 * watchdog.c - v0.1                                    (c) 2007 Micro-key bv
 * ---------------------------------------------------------------------------
 * Micro-key bv
 * Industrieweg 28, 9804 TG Noordhorn
 * Postbus 92, 9800 AB Zuidhorn
 * The Netherlands
 * Tel: +31 594 503020
 * Fax: +31 594 505825
 * Email: support@microkey.nl  
 * Web: www.microkey.nl
 * ---------------------------------------------------------------------------
 * Description: Watchdog funcitonality
 * ---------------------------------------------------------------------------
 * Version(s):  0.1, 28-11-2007, fvds.
 *                   Creation.
 * ---------------------------------------------------------------------------
 */

/* ---------------------------------------------------------------------------
 * System include files
 * ---------------------------------------------------------------------------
 */

/* ---------------------------------------------------------------------------
 * Application include files
 * ---------------------------------------------------------------------------
 */
#include "LPC23xx.h"
#include "types.h"
#include "watchdog.h"

/* FreeRTOS includes */
#include "FreeRTOS.h"

/* ---------------------------------------------------------------------------
 * Local constant and macro definitions
 * ---------------------------------------------------------------------------
 */
#define WD_CLKSRC_APB       (0x01)
#define WD_CLKSRC_IRC_OSC   (0x00)
#define WD_EN               (0x01)
#define WD_RESET            (0x02)
#define WD_WTOF             (0x04)

/* ---------------------------------------------------------------------------
 * Global variable definitions
 * ---------------------------------------------------------------------------
 */

/* ---------------------------------------------------------------------------
 * Local variable definitions
 * ---------------------------------------------------------------------------
 */
static INT16 WtofStatus = -1;

/* ---------------------------------------------------------------------------
 * Local function definitions
 * ---------------------------------------------------------------------------
 */

/** \brief Enable the watchdog */
void watchdogEnable( 
        UINT16 resetTime   /**< Time in ms till watchdog will reset target when not fed in meantime */
        )
{
    UINT32 prescaleFeedValue;
    
    // Make sure the WD_WTOF is stored
    watchdogCausedReset();
    
    // Internal RC oscilator runs on 4 Mhz, the prescale is calculated by:
    //       1                                  resetTime 
    // ------------ * 4 * prescaleFeedValue = (-----------) (seconden)
    //  4.000.000                                 1000
    //
    // 
    prescaleFeedValue = resetTime * 1000;
    WDTC = prescaleFeedValue;  /* once WDEN is set, the WDT will start after feeding */
    WDMOD = WD_EN | WD_RESET;

    WDFEED = 0xAA;    /* Feeding sequence */
    WDFEED = 0x55;
}


/** \brief Feed the watchdog in order to prevent a reset */
void watchdogFeed()
{
    WDFEED = 0xAA;    /* Feeding sequence */
    WDFEED = 0x55;
}

BOOLEAN watchdogCausedReset()
{
	if ( WtofStatus < 0)
	{
		WtofStatus = ((WDMOD & WD_WTOF) == WD_WTOF ? 1 : 0);

		// Clear bit 
		WDMOD &=  ~WD_WTOF;
	}
	
	return (WtofStatus == 1 ? TRUE : FALSE);
}