Bluetooth: CAP: Implement bt_cap_initiator_broadcast_foreach_stream

Implement the function bt_cap_initiator_broadcast_foreach_stream that
allows users to iterate on all BAP streams in a BAP broadcast source.
This can be used to easily get references to other broadcast streams in
the same group.

Signed-off-by: Emil Gydesen <[email protected]>

Author: Thalley

include/zephyr/bluetooth/audio/cap.h

@@ -812,6 +812,32 @@ int bt_cap_initiator_broadcast_audio_delete(struct bt_cap_broadcast_source *broa
 int bt_cap_initiator_broadcast_get_base(struct bt_cap_broadcast_source *broadcast_source,
 					struct net_buf_simple *base_buf);
 
+/** Callback function for bt_cap_initiator_broadcast_foreach_stream()
+ *
+ * @param stream     The audio stream
+ * @param user_data  User data
+ *
+ * @retval true Stop iterating.
+ * @retval false Continue iterating.
+ */
+typedef bool (*bt_cap_initiator_broadcast_foreach_stream_func_t)(struct bt_cap_stream *stream,
+								 void *user_data);
+
+/**
+ * @brief Iterate through all streams in a broadcast source
+ *
+ * @param broadcast_source  The broadcast source.
+ * @param func              The callback function.
+ * @param user_data         User specified data that is sent to the callback function.
+ *
+ * @retval 0          Success (even if no streams exists in the group).
+ * @retval -ECANCELED The @p func returned true.
+ * @retval -EINVAL    @p unicast_group or @p func were NULL.
+ */
+int bt_cap_initiator_broadcast_foreach_stream(struct bt_cap_broadcast_source *broadcast_source,
+					      bt_cap_initiator_broadcast_foreach_stream_func_t func,
+					      void *user_data);
+
 /** Parameters for  bt_cap_handover_unicast_to_broadcast() */
 struct bt_cap_handover_unicast_to_broadcast_param {
 	/** The type of the set. */

subsys/bluetooth/audio/cap_initiator.c

@@ -443,6 +443,47 @@ int bt_cap_initiator_broadcast_get_base(struct bt_cap_broadcast_source *broadcas
 	return bt_bap_broadcast_source_get_base(broadcast_source->bap_broadcast, base_buf);
 }
 
+struct cap_broadcast_source_foreach_stream_data {
+	bt_cap_initiator_broadcast_foreach_stream_func_t func;
+	void *user_data;
+};
+
+static bool cap_broadcast_source_foreach_stream_cb(struct bt_bap_stream *bap_stream,
+						   void *user_data)
+{
+	struct cap_broadcast_source_foreach_stream_data *data = user_data;
+
+	/* Since we are iterating on a CAP unicast group, we can assume that all streams are CAP
+	 * streams
+	 */
+	data->func(CONTAINER_OF(bap_stream, struct bt_cap_stream, bap_stream), data->user_data);
+
+	return false;
+}
+
+int bt_cap_initiator_broadcast_foreach_stream(struct bt_cap_broadcast_source *broadcast_source,
+					      bt_cap_initiator_broadcast_foreach_stream_func_t func,
+					      void *user_data)
+{
+	struct cap_broadcast_source_foreach_stream_data data = {
+		.func = func,
+		.user_data = user_data,
+	};
+
+	if (broadcast_source == NULL) {
+		LOG_DBG("source is NULL");
+		return -EINVAL;
+	}
+
+	if (func == NULL) {
+		LOG_DBG("func is NULL");
+		return -EINVAL;
+	}
+
+	return bt_bap_broadcast_source_foreach_stream(
+		broadcast_source->bap_broadcast, cap_broadcast_source_foreach_stream_cb, &data);
+}
+
 #endif /* CONFIG_BT_BAP_BROADCAST_SOURCE */
 
 #if defined(CONFIG_BT_BAP_UNICAST_CLIENT)