Add support for nRF52 Watchdog

Author: manchoz

targets/TARGET_NORDIC/TARGET_NRF5x/TARGET_NRF52/TARGET_MCU_NRF52840/config/sdk_config.h

@@ -4451,6 +4451,18 @@
 #define NRFX_WDT_CONFIG_LOG_LEVEL 3
 #endif
 
+
+// <e> NRFX_WDT_CONFIG_NO_IRQ - Remove WDT IRQ handling from WDT driver.
+//==========================================================
+
+// <0=> Include WDT IRQ handling
+// <1=> Remove WDT IRQ handling
+
+#ifndef NRFX_WDT_CONFIG_NO_IRQ
+#define NRFX_WDT_CONFIG_NO_IRQ 1
+#endif
+
+
 // <o> NRFX_WDT_CONFIG_INFO_COLOR  - ANSI escape code prefix.
 
 // <0=> Default 

targets/TARGET_NORDIC/TARGET_NRF5x/TARGET_NRF52/watchdog_api.c

@@ -0,0 +1,81 @@
+/*
+ * Copyright (c) 2019 Trampoline SRL
+ * Copyright (c) 2019 Giampaolo Mancini <[email protected]>
+ *
+ * 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.
+ */
+
+#include "watchdog_api.h"
+#include "nrfx_wdt.h"
+
+#if DEVICE_WATCHDOG
+
+static void dummy(void) {
+}
+
+watchdog_status_t hal_watchdog_init(const watchdog_config_t *config)
+{
+    nrfx_err_t err_code;
+
+    // nRF would allow a 4294967295 ms refresh value but
+    // Mbed OS allows max UINT32_MAX ms rehfreses.
+    if ( config->timeout_ms < 15U && config->timeout_ms > 65535U ) {
+        return WATCHDOG_STATUS_INVALID_ARGUMENT;
+    }
+
+    nrfx_wdt_config_t nrf_cfg = NRFX_WDT_DEAFULT_CONFIG;
+
+    nrf_cfg.reload_value = config->timeout_ms;
+    nrf_cfg.behaviour = NRF_WDT_BEHAVIOUR_RUN_SLEEP_HALT;
+
+    err_code = nrfx_wdt_init(&nrf_cfg, dummy);
+    if (err_code != NRFX_SUCCESS) {
+        return WATCHDOG_STATUS_INVALID_ARGUMENT;
+    }
+
+    nrfx_wdt_channel_id channel;
+    if (nrfx_wdt_channel_alloc(&channel) != NRF_SUCCESS) {
+        return WATCHDOG_STATUS_INVALID_ARGUMENT;
+    }
+    nrfx_wdt_enable();
+    nrfx_wdt_feed();
+
+    return WATCHDOG_STATUS_OK;
+}
+
+void hal_watchdog_kick(void)
+{
+    nrfx_wdt_feed();
+}
+
+watchdog_status_t hal_watchdog_stop(void)
+{
+    return WATCHDOG_STATUS_NOT_SUPPORTED;
+}
+
+uint32_t hal_watchdog_get_reload_value(void)
+{
+    // Convert to milliseconds from 32768 Hz clock ticks.
+    return nrf_wdt_reload_value_get() / 32768U * 1000;
+}
+
+watchdog_features_t hal_watchdog_get_platform_features(void)
+{
+    watchdog_features_t features;
+    features.max_timeout = 0xFFFF;
+    features.update_config = false;
+    features.disable_watchdog = false;
+    return features;
+}
+
+#endif // DEVICE_WATCHDOG