Added independent watchdog support

2 files changed, 107 insertions, 0 deletions

diff --git a/libmaple/iwdg.c b/libmaple/iwdg.c
new file mode 100644
index 0000000..82a0151
--- /dev/null
+++ b/libmaple/iwdg.c
@@ -0,0 +1,56 @@
+/******************************************************************************
+ * 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 support
+ */
+
+#include "libmaple.h"
+#include "iwdg.h"
+
+#define IWDG_UNLOCK   0x5555
+#define IWDG_START    0xCCCC
+#define IWDG_FEED     0xAAAA
+
+/**
+ *  @brief Initialise and start the watchdog
+ *
+ *  The prescaler and reload set the timeout.  A prescaler of 3 divides
+ *  the 40 kHz clock by 32 and gives roughly 1 ms per reload.
+ */
+void iwdg_init(uint8 prescaler, uint16 reload) {
+    __write(IWDG_KR, IWDG_UNLOCK);
+    __write(IWDG_PR, prescaler);
+    __write(IWDG_RLR, reload);
+
+    /* Start things off */
+    __write(IWDG_KR, IWDG_START);
+    __write(IWDG_KR, IWDG_FEED);
+}
+
+void iwdg_feed(void) {
+    __write(IWDG_KR, IWDG_FEED);
+}
diff --git a/libmaple/iwdg.h b/libmaple/iwdg.h
new file mode 100644
index 0000000..6002867
--- /dev/null
+++ b/libmaple/iwdg.h
@@ -0,0 +1,51 @@
+/******************************************************************************
+ * 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.h
+ *
+ *  @brief Independent watchdog support
+ */
+
+#ifndef _IWDG_H_
+#define _IWDG_H_
+
+#ifdef __cplusplus
+extern "C"{
+#endif
+
+#define IWDG_BASE               0x40003000
+#define IWDG_KR                 (IWDG_BASE + 0x0)
+#define IWDG_PR                 (IWDG_BASE + 0x4)
+#define IWDG_RLR                (IWDG_BASE + 0x8)
+#define IWDG_SR                 (IWDG_BASE + 0xC)
+
+void iwdg_init(uint8 prescaler, uint16 reload);
+void iwdg_feed(void);
+
+#ifdef __cplusplus
+} // extern "C"
+#endif
+
+#endif