LPC1768 WDT implementation

Author: chrissnow

targets/TARGET_NXP/TARGET_LPC176X/watchdog_api.c

@@ -0,0 +1,67 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2006-2018 ARM Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+
+#ifdef DEVICE_WATCHDOG
+
+#include "watchdog_api.h"
+#include "reset_reason_api.h"
+#include "device.h"
+#include "mbed_error.h"
+#include <stdbool.h>
+
+
+
+watchdog_status_t hal_watchdog_init(const watchdog_config_t *config)
+{
+    LPC_WDT->WDCLKSEL = 0x1;                //CLK src to PCLK
+    uint32_t clk = SystemCoreClock / 16; // WD has a fixed /4 prescaler, PCLK default is /4
+    LPC_WDT->WDTC = ((float)config->timeout_ms )* clk/1000;
+    LPC_WDT->WDMOD = 0x3;                   // Enable and Reset
+    hal_watchdog_kick();
+
+    return WATCHDOG_STATUS_OK;
+}
+
+void hal_watchdog_kick(void)
+{
+    LPC_WDT->WDFEED = 0xAA;
+    LPC_WDT->WDFEED = 0x55;
+}
+watchdog_status_t hal_watchdog_stop(void)
+{
+    return WATCHDOG_STATUS_NOT_SUPPORTED;
+}
+
+uint32_t hal_watchdog_get_reload_value(void)
+{
+    uint32_t clk = SystemCoreClock / 16; // WD has a fixed /4 prescaler, PCLK default is /4
+
+    return (float)LPC_WDT->WDTC/clk*1000;
+}
+
+watchdog_features_t hal_watchdog_get_platform_features(void)
+{
+    uint32_t clk = SystemCoreClock / 16; // WD has a fixed /4 prescaler, PCLK default is /4
+    watchdog_features_t features;
+    features.max_timeout = ((float)INT32_MAX/clk)*1000;
+    features.update_config = true;
+    features.disable_watchdog = false;
+
+    return features;
+}
+
+#endif // DEVICE_WATCHDOG

targets/targets.json

@@ -624,7 +624,8 @@
             "STDIO_MESSAGES",
             "FLASH",
             "MPU",
-            "USBDEVICE"
+            "USBDEVICE",
+            "WATCHDOG"
         ],
         "release_versions": ["2", "5"],
         "device_name": "LPC1768",