net: openthread: Implement energy scan in openthread using radio driv…

…er api

OpenThread has api to make use of radios energy scan feature.
Implemented this api in zephyr. This allows thread to perform energy
scan when needed.

Signed-off-by: Marek Porwisz <[email protected]>

subsys/net/lib/openthread/platform/radio.c

@@ -11,11 +11,10 @@
  *
  */
 
-#define LOG_LEVEL CONFIG_OPENTHREAD_LOG_LEVEL
 #define LOG_MODULE_NAME net_otPlat_radio
 
 #include <logging/log.h>
-LOG_MODULE_REGISTER(LOG_MODULE_NAME);
+LOG_MODULE_REGISTER(LOG_MODULE_NAME, CONFIG_OPENTHREAD_L2_LOG_LEVEL);
 
 #include <stdbool.h>
 #include <stddef.h>
@@ -43,6 +42,15 @@ LOG_MODULE_REGISTER(LOG_MODULE_NAME);
 #define FRAME_TYPE_MASK 0x07
 #define FRAME_TYPE_ACK 0x02
 
+
+enum pending_events {
+	PENDING_EVENT_DETECT_ENERGY, /* Requested to start Energy Detection
+				      * procedure.
+				      */
+	PENDING_EVENT_DETECT_ENERGY_DONE, /* Energy Detection finished. */
+	PENDING_EVENT_COUNT /* keep last */
+};
+
 static otRadioState sState = OT_RADIO_STATE_DISABLED;
 
 static otRadioFrame sTransmitFrame;
@@ -58,6 +66,42 @@ static struct ieee802154_radio_api *radio_api;
 static s8_t tx_power;
 static u16_t channel;
 
+static u16_t energy_detection_time;
+static u8_t  energy_detection_channel;
+static s16_t energy_detected_value;
+
+ATOMIC_DEFINE(pending_events, PENDING_EVENT_COUNT);
+
+
+static inline bool is_pending_event_set(enum pending_events event)
+{
+	return atomic_test_bit(pending_events, event);
+}
+
+static void set_pending_event(enum pending_events event)
+{
+	atomic_set_bit(pending_events, event);
+	otSysEventSignalPending();
+}
+
+static void reset_pending_event(enum pending_events event)
+{
+	atomic_clear_bit(pending_events, event);
+}
+
+static inline void clear_pending_events(void)
+{
+	atomic_clear(pending_events);
+}
+
+void energy_detected(struct device *dev, s16_t max_ed)
+{
+	if (dev == radio_dev) {
+		energy_detected_value = max_ed;
+		set_pending_event(PENDING_EVENT_DETECT_ENERGY_DONE);
+	}
+}
+
 enum net_verdict ieee802154_radio_handle_ack(struct net_if *iface,
 					     struct net_pkt *pkt)
 {
@@ -123,6 +167,7 @@ void platformRadioInit(void)
 
 void platformRadioProcess(otInstance *aInstance)
 {
+	bool event_pending = false;
 	if (sState == OT_RADIO_STATE_TRANSMIT) {
 		otError result = OT_ERROR_NONE;
 
@@ -180,6 +225,27 @@ void platformRadioProcess(otInstance *aInstance)
 			}
 		}
 	}
+
+	if (is_pending_event_set(PENDING_EVENT_DETECT_ENERGY)) {
+		radio_api->set_channel(radio_dev, energy_detection_channel);
+
+		if (!radio_api->ed_scan(radio_dev, energy_detection_time,
+					energy_detected)) {
+			reset_pending_event(PENDING_EVENT_DETECT_ENERGY);
+		} else {
+			event_pending = true;
+		}
+	}
+
+	if (is_pending_event_set(PENDING_EVENT_DETECT_ENERGY_DONE)) {
+		otPlatRadioEnergyScanDone(aInstance,
+					  (s8_t)energy_detected_value);
+		reset_pending_event(PENDING_EVENT_DETECT_ENERGY_DONE);
+	}
+
+	if (event_pending) {
+		otSysEventSignalPending();
+	}
 }
 
 uint16_t platformRadioChannelGet(otInstance *aInstance)
@@ -305,9 +371,20 @@ int8_t otPlatRadioGetRssi(otInstance *aInstance)
 
 otRadioCaps otPlatRadioGetCaps(otInstance *aInstance)
 {
+	otRadioCaps caps = OT_RADIO_CAPS_NONE;
+
+	enum ieee802154_hw_caps radio_caps;
 	ARG_UNUSED(aInstance);
+	__ASSERT(radio_api,
+	    "platformRadioInit needs to be called prior to otPlatRadioGetCaps");
+
+	radio_caps = radio_api->get_capabilities(radio_dev);
 
-	return OT_RADIO_CAPS_NONE;
+	if (radio_caps & IEEE802154_HW_ENERGY_SCAN) {
+		caps |= OT_RADIO_CAPS_ENERGY_SCAN;
+	}
+
+	return caps;
 }
 
 bool otPlatRadioGetPromiscuous(otInstance *aInstance)
@@ -333,11 +410,26 @@ void otPlatRadioSetPromiscuous(otInstance *aInstance, bool aEnable)
 otError otPlatRadioEnergyScan(otInstance *aInstance, u8_t aScanChannel,
 			      u16_t aScanDuration)
 {
-	ARG_UNUSED(aInstance);
-	ARG_UNUSED(aScanChannel);
-	ARG_UNUSED(aScanDuration);
+	energy_detection_time    = aScanDuration;
+	energy_detection_channel = aScanChannel;
+
+	clear_pending_events();
+
+	radio_api->set_channel(radio_dev, aScanChannel);
 
-	return OT_ERROR_NOT_IMPLEMENTED;
+	if (radio_api->ed_scan(radio_dev, energy_detection_time,
+				    energy_detected) != 0) {
+		/*
+		 * OpenThread API does not accept failure of this function,
+		 * it can return 'No Error' or 'Not Implemented' error only.
+		 * If ed_scan start failed event is set to schedule the scan at
+		 * later time.
+		 */
+		LOG_ERR("Failed do start energy scan, scheduling for later");
+		set_pending_event(PENDING_EVENT_DETECT_ENERGY);
+	}
+
+	return OT_ERROR_NONE;
 }
 
 void otPlatRadioEnableSrcMatch(otInstance *aInstance, bool aEnable)