lorawan: use callback function signature typedefs

This avoids duplication of the function signature in several places and
makes the API documentation more clean.

Signed-off-by: Martin Jäger <[email protected]>

Author: martinjaeger

include/zephyr/lorawan/lorawan.h

@@ -175,20 +175,32 @@ struct lorawan_downlink_cb {
 };
 
 /**
- * @brief Add battery level callback function.
+ * @brief Defines the battery level callback handler function signature.
+ *
+ * @retval 0      if the node is connected to an external power source
+ * @retval 1..254 battery level, where 1 is the minimum and 254 is the maximum value
+ * @retval 255    if the node was not able to measure the battery level
+ */
+typedef uint8_t (*lorawan_battery_level_cb_t)(void);
+
+/**
+ * @brief Defines the datarate changed callback handler function signature.
+ *
+ * @param dr Updated datarate.
+ */
+typedef void (*lorawan_dr_changed_cb_t)(enum lorawan_datarate dr);
+
+/**
+ * @brief Register a battery level callback function.
  *
  * Provide the LoRaWAN stack with a function to be called whenever a battery
- * level needs to be read. As per LoRaWAN specification the callback needs to
- * return "0:      node is connected to an external power source,
- *         1..254: battery level, where 1 is the minimum and 254 is the maximum
- *                 value,
- *         255: the node was not able to measure the battery level"
+ * level needs to be read.
  *
  * Should no callback be provided the lorawan backend will report 255.
  *
- * @param battery_lvl_cb Pointer to the battery level function
+ * @param cb Pointer to the battery level function
  */
-void lorawan_register_battery_level_callback(uint8_t (*battery_lvl_cb)(void));
+void lorawan_register_battery_level_callback(lorawan_battery_level_cb_t cb);
 
 /**
  * @brief Register a callback to be run on downlink packets
@@ -203,12 +215,9 @@ void lorawan_register_downlink_callback(struct lorawan_downlink_cb *cb);
  * The callback is called once upon successfully joining a network and again
  * each time the datarate changes due to ADR.
  *
- * The callback function takes one parameter:
- *	- dr - updated datarate
- *
- * @param dr_cb Pointer to datarate update callback
+ * @param cb Pointer to datarate update callback
  */
-void lorawan_register_dr_changed_callback(void (*dr_cb)(enum lorawan_datarate));
+void lorawan_register_dr_changed_callback(lorawan_dr_changed_cb_t cb);
 
 /**
  * @brief Join the LoRaWAN network

subsys/lorawan/lorawan.c

@@ -72,8 +72,8 @@ static LoRaMacEventInfoStatus_t last_mlme_indication_status;
 
 static LoRaMacRegion_t selected_region = DEFAULT_LORAWAN_REGION;
 
-static uint8_t (*get_battery_level_user)(void);
-static void (*dr_change_cb)(enum lorawan_datarate dr);
+static lorawan_battery_level_cb_t battery_level_cb;
+static lorawan_dr_changed_cb_t dr_changed_cb;
 
 /* implementation required by the soft-se (software secure element) */
 void BoardGetUniqueId(uint8_t *id)
@@ -83,11 +83,11 @@ void BoardGetUniqueId(uint8_t *id)
 
 static uint8_t get_battery_level(void)
 {
-	if (get_battery_level_user != NULL) {
-		return get_battery_level_user();
+	if (battery_level_cb != NULL) {
+		return battery_level_cb();
+	} else {
+		return 255;
 	}
-
-	return 255;
 }
 
 static void mac_process_notify(void)
@@ -105,8 +105,8 @@ static void datarate_observe(bool force_notification)
 	if ((mib_req.Param.ChannelsDatarate != current_datarate) ||
 	    (force_notification)) {
 		current_datarate = mib_req.Param.ChannelsDatarate;
-		if (dr_change_cb) {
-			dr_change_cb(current_datarate);
+		if (dr_changed_cb != NULL) {
+			dr_changed_cb(current_datarate);
 		}
 		LOG_INF("Datarate changed: DR_%d", current_datarate);
 	}
@@ -621,19 +621,19 @@ int lorawan_send(uint8_t port, uint8_t *data, uint8_t len,
 	return ret;
 }
 
-void lorawan_register_battery_level_callback(uint8_t (*battery_lvl_cb)(void))
+void lorawan_register_battery_level_callback(lorawan_battery_level_cb_t cb)
 {
-	get_battery_level_user = battery_lvl_cb;
+	battery_level_cb = cb;
 }
 
 void lorawan_register_downlink_callback(struct lorawan_downlink_cb *cb)
 {
 	sys_slist_append(&dl_callbacks, &cb->node);
 }
 
-void lorawan_register_dr_changed_callback(void (*cb)(enum lorawan_datarate))
+void lorawan_register_dr_changed_callback(lorawan_dr_changed_cb_t cb)
 {
-	dr_change_cb = cb;
+	dr_changed_cb = cb;
 }
 
 int lorawan_start(void)