Add watchdog routines for Due

hardware/arduino/sam/cores/arduino/Arduino.h

@@ -194,6 +194,8 @@ extern const PinDescription g_APinDescription[] ;
 #include "wiring_shift.h"
 #include "WInterrupts.h"
 
+#include "watchdog.h"
+
 // USB Device
 #define USB_VID            0x2341 // arduino LLC vid
 #define USB_PID_LEONARDO   0x0034

hardware/arduino/sam/cores/arduino/main.cpp

@@ -41,6 +41,9 @@ void initVariant() { }
  */
 int main( void )
 {
+	// Initialize watchdog
+	watchdogSetup();
+
 	init();
 
 	initVariant();

hardware/arduino/sam/cores/arduino/watchdog.cpp

@@ -0,0 +1,55 @@
+/*
+  Copyright (c) 2014 Arduino.  All right reserved.
+
+  This library is free software; you can redistribute it and/or
+  modify it under the terms of the GNU Lesser General Public
+  License as published by the Free Software Foundation; either
+  version 2.1 of the License, or (at your option) any later version.
+
+  This library 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 Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public
+  License along with this library; if not, write to the Free Software
+  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+
+#include <chip.h>
+
+#include "watchdog.h"
+
+
+void watchdogEnable (uint32_t timeout)
+{
+	/* this assumes the slow clock is running at 32.768 kHz
+	   watchdog frequency is therefore 32768 / 128 = 256 Hz */
+	timeout = timeout * 256 / 1000; 
+	if (timeout == 0)
+		timeout = 1;
+	else if (timeout > 0xFFF)
+		timeout = 0xFFF;
+	timeout = WDT_MR_WDRSTEN | WDT_MR_WDV(timeout) | WDT_MR_WDD(timeout);
+	WDT_Enable (WDT, timeout);
+}
+
+void watchdogDisable(void)
+{
+	WDT_Disable (WDT);
+}
+
+void watchdogReset(void)
+{
+	WDT_Restart (WDT);
+}
+
+
+extern "C"
+void _watchdogDefaultSetup (void)
+{
+	WDT_Disable (WDT);
+}
+void watchdogSetup (void) __attribute__ ((weak, alias("_watchdogDefaultSetup")));
+
+

hardware/arduino/sam/cores/arduino/watchdog.h

@@ -0,0 +1,52 @@
+/*
+  Copyright (c) 2014 Arduino.  All right reserved.
+
+  This library is free software; you can redistribute it and/or
+  modify it under the terms of the GNU Lesser General Public
+  License as published by the Free Software Foundation; either
+  version 2.1 of the License, or (at your option) any later version.
+
+  This library 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 Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public
+  License along with this library; if not, write to the Free Software
+  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+
+#ifndef _WATCHDOG_
+#define _WATCHDOG_
+
+#include <stdint.h>
+
+// Watchdog functions
+
+/*
+ * \brief Enable the watchdog with the specified timeout. Should only be called once.
+ *
+ * \param timeount in milliseconds.
+ */
+void watchdogEnable (uint32_t timeout);
+
+/*
+ * \brief Disable the watchdog timer. Should only be called once.
+ *
+ */
+void watchdogDisable (void);
+
+/*
+ * \brief Reset the watchdog counter.
+ *
+ */
+void watchdogReset (void);
+
+/*
+ * \brief Watchdog initialize hook. This function is called from init(). If the user does not provide
+ * this function, then the default action is to disable watchdog.
+ */
+void watchdogSetup (void);
+
+#endif /* _WATCHDOG_ */
+

hardware/arduino/sam/variants/arduino_due_x/variant.cpp

@@ -377,9 +377,6 @@ void init( void )
     while (true);
   }
 
-  // Disable watchdog
-  WDT_Disable(WDT);
-
   // Initialize C library
   __libc_init_array();