Bluetooth: Audio: Add BAP broadcast sink support

Add support for the BAP broadcast sink role. This role
allows a device to sync to a broadcast ISO stream.

Signed-off-by: Emil Gydesen <emil.gydesen@nordicsemi.no>

include/bluetooth/audio/audio.h

@@ -51,8 +51,13 @@ extern "C" {
 #define BT_AUDIO_UNICAST_ANNOUNCEMENT_GENERAL    0x00
 #define BT_AUDIO_UNICAST_ANNOUNCEMENT_TARGETED   0x01
 
+#if defined(CONFIG_BT_AUDIO_BROADCAST_SINK)
+#define BROADCAST_SNK_STREAM_CNT CONFIG_BT_AUDIO_BROADCAST_SNK_STREAM_COUNT
+#define BROADCAST_SUBGROUP_CNT CONFIG_BT_AUDIO_BROADCAST_SUBGROUP_COUNT
+#else /* !CONFIG_BT_AUDIO_BROADCAST_SINK */
 #define BROADCAST_SNK_STREAM_CNT 0
 #define BROADCAST_SUBGROUP_CNT 0
+#endif /* CONFIG_BT_AUDIO_BROADCAST_SINK*/
 
 /** @brief Abstract Audio Unicast Group structure. */
 struct bt_audio_unicast_group;

subsys/bluetooth/audio/CMakeLists.txt

@@ -49,3 +49,4 @@ zephyr_library_sources_ifdef(CONFIG_BT_AUDIO_UNICAST_SERVER unicast_server.c)
 zephyr_library_sources_ifdef(CONFIG_BT_AUDIO_CAPABILITIES capabilities.c)
 zephyr_library_sources_ifdef(CONFIG_BT_AUDIO_UNICAST_CLIENT unicast_client.c)
 zephyr_library_sources_ifdef(CONFIG_BT_AUDIO_BROADCAST_SOURCE broadcast_source.c)
+zephyr_library_sources_ifdef(CONFIG_BT_AUDIO_BROADCAST_SINK broadcast_sink.c)

subsys/bluetooth/audio/Kconfig.baps

@@ -149,6 +149,40 @@ config BT_AUDIO_BROADCAST_SRC_STREAM_COUNT
 
 endif # BT_AUDIO_BROADCAST_SOURCE
 
+config BT_AUDIO_BROADCAST_SINK
+	bool "Bluetooth Broadcast Sink Audio Support [EXPERIMENTAL]"
+	select EXPERIMENTAL
+	select BT_ISO_SYNC_RECEIVER
+	help
+	  This option enables support for Bluetooth Broadcast Sink Audio using
+	  Isochronous channels.
+
+if BT_AUDIO_BROADCAST_SINK
+
+config BT_AUDIO_BROADCAST_SUBGROUP_COUNT
+	int # hidden: TODO: Update once the API supports it
+	default 1
+
+config BT_AUDIO_BROADCAST_SNK_COUNT
+	int "Basic Audio Broadcaster Sink count"
+	default 1
+	range 0 BT_ISO_MAX_BIG
+	help
+	  This option sets the number of broadcast sinks to support.
+	  One broadcast sink can receive multiple streams
+	  (up to BT_AUDIO_BROADCAST_SNK_STREAM_COUNT per broadcast sink).
+
+config BT_AUDIO_BROADCAST_SNK_STREAM_COUNT
+	int "Basic Audio Broadcast Sink Stream count"
+	depends on BT_AUDIO_BROADCAST_SNK_COUNT > 0
+	default 1
+	range 1 BT_ISO_MAX_CHAN
+	help
+	  This option sets the maximum number of streams per broadcast sink
+	  to support.
+
+endif # BT_AUDIO_BROADCAST_SINK
+
 config BT_AUDIO_DEBUG
 	bool "Enable debug logs"
 	depends on BT_DEBUG
@@ -207,17 +241,25 @@ config BT_AUDIO_DEBUG_BROADCAST_SOURCE
 	  Use this option to enable Bluetooth Audio Broadcast Source debug logs
 	  for the Bluetooth Audio functionality.
 
+config BT_AUDIO_DEBUG_BROADCAST_SINK
+	bool "Bluetooth Audio Broadcast Sink debug"
+	depends on BT_AUDIO_BROADCAST_SINK
+	help
+	  Use this option to enable Bluetooth Audio Broadcast Sink debug logs
+	  for the Bluetooth Audio functionality.
+
 endif # BT_AUDIO_DEBUG
 
 config BT_AUDIO_STREAM
 	# Virtual/hidden option
 	bool
-	default y if BT_ASCS || BT_AUDIO_UNICAST_CLIENT || BT_AUDIO_BROADCAST_SOURCE
+	default y if BT_ASCS || BT_AUDIO_UNICAST_CLIENT || \
+			BT_AUDIO_BROADCAST_SOURCE || BT_AUDIO_BROADCAST_SINK
 
 config BT_AUDIO_CAPABILITIES
 	# Virtual/hidden option
 	bool
-	default y if BT_ASCS
+	default y if BT_ASCS || BT_AUDIO_BROADCAST_SINK
 
 rsource "Kconfig.pacs"
 rsource "Kconfig.ascs"

subsys/bluetooth/audio/stream.c

@@ -185,9 +185,10 @@ bool bt_audio_valid_qos(const struct bt_codec_qos *qos)
 
 static bool bt_audio_stream_is_broadcast(const struct bt_audio_stream *stream)
 {
-	/* TODO: Add broadcast sink */
 	return (IS_ENABLED(CONFIG_BT_AUDIO_BROADCAST_SOURCE) &&
-		bt_audio_ep_is_broadcast_src(stream->ep));
+		bt_audio_ep_is_broadcast_src(stream->ep)) ||
+	       (IS_ENABLED(CONFIG_BT_AUDIO_BROADCAST_SINK) &&
+		bt_audio_ep_is_broadcast_snk(stream->ep));
 }
 
 bool bt_audio_valid_stream_qos(const struct bt_audio_stream *stream,

tests/bluetooth/shell/audio.conf

@@ -39,6 +39,7 @@ CONFIG_BT_AUDIO=y
 CONFIG_BT_AUDIO_UNICAST_SERVER=y
 CONFIG_BT_AUDIO_UNICAST_CLIENT=y
 CONFIG_BT_AUDIO_BROADCAST_SOURCE=y
+CONFIG_BT_AUDIO_BROADCAST_SINK=y
 CONFIG_BT_ISO_TX_BUF_COUNT=5
 CONFIG_BT_VOCS_MAX_INSTANCE_COUNT=1
 CONFIG_BT_VOCS_CLIENT_MAX_INSTANCE_COUNT=1