From 4725d750546b5bb2c6abf20fa213b06742eb9766 Mon Sep 17 00:00:00 2001
From: Bob Cousins <bobcousins42@googlemail.com>
Date: Sun, 27 Jul 2014 13:01:40 +0100
Subject: [PATCH] Add watchdog routines for Due.

---
 .../sam/variants/arduino_due_x/variant.cpp    | 50 ++++++++++++++++++-
 .../sam/variants/arduino_due_x/variant.h      | 20 ++++++++
 2 files changed, 68 insertions(+), 2 deletions(-)

diff --git a/hardware/arduino/sam/variants/arduino_due_x/variant.cpp b/hardware/arduino/sam/variants/arduino_due_x/variant.cpp
index 4cbe0df80..999b5d4f7 100644
--- a/hardware/arduino/sam/variants/arduino_due_x/variant.cpp
+++ b/hardware/arduino/sam/variants/arduino_due_x/variant.cpp
@@ -358,6 +358,52 @@ void serialEventRun(void)
   if (Serial3.available()) serialEvent3();
 }
 
+// ----------------------------------------------------------------------------
+extern "C" {
+
+/**
+ * Watchdog enable
+ *
+ * Enable the watchdog timer with the specified settings.
+ * WDTO_xxx macros provide standard settings.
+ * Should only be called once.
+ */
+void wdt_enable (uint32_t mode)
+{
+	WDT_Enable (WDT, mode);
+}
+
+/**
+ * Watchdog disable
+ *
+ * Disable the watchdog timer.
+ * Should only be called once.
+ */
+void wdt_disable(void)
+{
+	WDT_Disable (WDT);
+}
+
+/**
+ * Watchdog reset
+ *
+ * Resets the watchdog counter
+ */
+void wdt_reset(void)
+{
+	WDT_Restart (WDT);
+}
+
+}  // extern "C"
+
+/**
+ * Watchdog initialize hook
+ *
+ * This function is called from init().
+ * Default action is to disable watchdog.
+ */
+void wdt_initialize(void) __attribute__ ((weak, alias("wdt_disable")));
+
 // ----------------------------------------------------------------------------
 
 #ifdef __cplusplus
@@ -377,8 +423,8 @@ void init( void )
     while (true);
   }
 
-  // Disable watchdog
-  WDT_Disable(WDT);
+  // Initialize watchdog
+  wdt_initialize();
 
   // Initialize C library
   __libc_init_array();
diff --git a/hardware/arduino/sam/variants/arduino_due_x/variant.h b/hardware/arduino/sam/variants/arduino_due_x/variant.h
index 6725a139c..d265255e4 100644
--- a/hardware/arduino/sam/variants/arduino_due_x/variant.h
+++ b/hardware/arduino/sam/variants/arduino_due_x/variant.h
@@ -232,6 +232,25 @@ static const uint8_t CAN1TX = 89;
 #define TC_MIN_DUTY_CYCLE   0
 #define TC_RESOLUTION		8
 
+// Watchdog routines
+
+#define WDTO_15MS	WDT_MR_WDRSTEN | WDT_MR_WDRPROC | WDT_MR_WDV(4) | WDT_MR_WDD(4)
+#define WDTO_30MS	WDT_MR_WDRSTEN | WDT_MR_WDRPROC | WDT_MR_WDV(8) | WDT_MR_WDD(8)
+#define WDTO_60MS 	WDT_MR_WDRSTEN | WDT_MR_WDRPROC | WDT_MR_WDV(15) | WDT_MR_WDD(15)
+#define WDTO_120MS	WDT_MR_WDRSTEN | WDT_MR_WDRPROC | WDT_MR_WDV(31) | WDT_MR_WDD(31)
+#define WDTO_250MS	WDT_MR_WDRSTEN | WDT_MR_WDRPROC | WDT_MR_WDV(64) | WDT_MR_WDD(64)
+#define WDTO_500MS	WDT_MR_WDRSTEN | WDT_MR_WDRPROC | WDT_MR_WDV(128) | WDT_MR_WDD(128)
+#define WDTO_1S		WDT_MR_WDRSTEN | WDT_MR_WDRPROC | WDT_MR_WDV(256) | WDT_MR_WDD(256)
+#define WDTO_2S		WDT_MR_WDRSTEN | WDT_MR_WDRPROC | WDT_MR_WDV(512) | WDT_MR_WDD(512)
+#define WDTO_4S		WDT_MR_WDRSTEN | WDT_MR_WDRPROC | WDT_MR_WDV(1024) | WDT_MR_WDD(1024)
+#define WDTO_8S		WDT_MR_WDRSTEN | WDT_MR_WDRPROC | WDT_MR_WDV(2048) | WDT_MR_WDD(2048)
+
+void wdt_enable (uint32_t mode);
+
+void wdt_disable(void);
+
+void wdt_reset(void);
+
 #ifdef __cplusplus
 }
 #endif
@@ -274,5 +293,6 @@ extern USARTClass Serial3;
 #define SERIAL_PORT_HARDWARE2       Serial2
 #define SERIAL_PORT_HARDWARE3       Serial3
 
+
 #endif /* _VARIANT_ARDUINO_DUE_X_ */