samples: Bluetooth: CAP Handover

Add a CAP Handover sample that uses the CAP handover API
as the CAP Initiator and CAP commander.

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

Author: Thalley

samples/bluetooth/cap_acceptor/Kconfig

@@ -20,7 +20,7 @@ config SAMPLE_UNICAST
 
 config SAMPLE_BROADCAST
 	bool "Whether or not to search for CAP acceptors for unicast audio"
-	default y if !SAMPLE_UNICAST
+	default y
 	select BT_BAP_SCAN_DELEGATOR
 	select BT_OBSERVER
 	select BT_ISO_SYNC_RECEIVER

samples/bluetooth/cap_acceptor/prj.conf

@@ -33,3 +33,5 @@ CONFIG_BT_ISO_MAX_CHAN=2
 
 # Support long Metadata size for audio configuration
 CONFIG_BT_AUDIO_CODEC_CFG_MAX_METADATA_SIZE=24
+
+CONFIG_BT_BAP_SCAN_DELEGATOR_LOG_LEVEL_DBG=y

samples/bluetooth/cap_acceptor/src/cap_acceptor.h

@@ -18,8 +18,8 @@
 struct peer_config {
 	/** Stream for the source endpoint */
 	struct bt_cap_stream source_stream;
-	/** Stream for the sink endpoint */
-	struct bt_cap_stream sink_stream;
+	/** Streams for the sink endpoint */
+	struct bt_cap_stream sink_streams[CONFIG_BT_ASCS_MAX_ASE_SNK_COUNT];
 	/** Semaphore to help wait for a release operation if the source stream is not idle */
 	struct k_sem source_stream_sem;
 	/** Semaphore to help wait for a release operation if the sink stream is not idle */

samples/bluetooth/cap_acceptor/src/cap_acceptor_broadcast.c

@@ -100,7 +100,6 @@ static int check_start_scan(void)
 static void broadcast_stream_started_cb(struct bt_bap_stream *bap_stream)
 {
 	LOG_INF("Started bap_stream %p", bap_stream);
-	total_broadcast_rx_iso_packet_count = 0U;
 
 	atomic_clear_bit(flags, FLAG_BROADCAST_SYNCING);
 	atomic_set_bit(flags, FLAG_BROADCAST_SYNCED);
@@ -256,11 +255,20 @@ static void syncable_cb(struct bt_bap_broadcast_sink *sink, const struct bt_iso_
 	}
 }
 
+static void sink_started_cb(struct bt_bap_broadcast_sink *sink)
+{
+	LOG_INF("Broadcast sink started");
+
+	/* Clear requested BIS sync */
+	broadcast_sink.requested_bis_sync = 0;
+	atomic_clear_bit(flags, FLAG_BROADCAST_SYNC_REQUESTED);
+}
+
 static void sink_stopped_cb(struct bt_bap_broadcast_sink *sink, uint8_t reason)
 {
 	int err;
 
-	LOG_INF("Broadcast sink stopped with reason %u", reason);
+	LOG_INF("Broadcast sink stopped with reason 0x%02X", reason);
 
 	err = bt_bap_broadcast_sink_delete(sink);
 	if (err != 0) {
@@ -481,7 +489,10 @@ static int bis_sync_req_cb(struct bt_conn *conn,
 		return -ENOMEM;
 	}
 
-	if (broadcast_sink.requested_bis_sync == new_bis_sync_req) {
+	if (atomic_test_bit(flags, FLAG_BROADCAST_SYNC_REQUESTED) &&
+	    broadcast_sink.requested_bis_sync == new_bis_sync_req) {
+		LOG_INF("New request (0x%08x) is the same as last request; ignoring",
+			new_bis_sync_req);
 		return 0; /* no op */
 	}
 
@@ -491,6 +502,8 @@ static int bis_sync_req_cb(struct bt_conn *conn,
 		 */
 		int err;
 
+		LOG_INF("Already synced. Stopping current sync and attempt resyncing");
+
 		/* The stream stopped callback will be called as part of this,
 		 * and we do not need to wait for any events from the
 		 * controller. Thus, when this returns, the broadcast sink is stopped
@@ -502,13 +515,7 @@ static int bis_sync_req_cb(struct bt_conn *conn,
 			return err;
 		}
 
-		err = bt_bap_broadcast_sink_delete(broadcast_sink.bap_broadcast_sink);
-		if (err != 0) {
-			LOG_ERR("Failed to delete Broadcast Sink: %d", err);
-
-			return err;
-		}
-		broadcast_sink.bap_broadcast_sink = NULL;
+		/* Broadcast sink will be deleted and set to NULL in `sink_stopped_cb` */
 
 		atomic_clear_bit(flags, FLAG_BROADCAST_SYNCED);
 	}
@@ -517,8 +524,6 @@ static int bis_sync_req_cb(struct bt_conn *conn,
 	if (broadcast_sink.requested_bis_sync != 0U) {
 		atomic_set_bit(flags, FLAG_BROADCAST_SYNC_REQUESTED);
 		check_sync_broadcast();
-	} else {
-		atomic_clear_bit(flags, FLAG_BROADCAST_SYNC_REQUESTED);
 	}
 
 	return 0;
@@ -568,10 +573,9 @@ static void bap_pa_sync_terminated_cb(struct bt_le_per_adv_sync *sync,
 	if (sync == broadcast_sink.pa_sync) {
 		int err;
 
-		LOG_INF("PA sync %p lost with reason %u", (void *)sync, info->reason);
+		LOG_INF("PA sync %p lost with reason 0x%02X", (void *)sync, info->reason);
 
 		/* Without PA we cannot sync to any new BIG - Clear data */
-		broadcast_sink.requested_bis_sync = 0;
 		broadcast_sink.pa_sync = NULL;
 		k_work_cancel_delayable(&pa_timer);
 		atomic_clear_bit(flags, FLAG_BROADCAST_SYNCABLE);
@@ -736,6 +740,7 @@ int init_cap_acceptor_broadcast(void)
 		static struct bt_bap_broadcast_sink_cb broadcast_sink_cbs = {
 			.base_recv = base_recv_cb,
 			.syncable = syncable_cb,
+			.started = sink_started_cb,
 			.stopped = sink_stopped_cb,
 		};
 		static struct bt_bap_stream_ops broadcast_stream_ops = {

samples/bluetooth/cap_acceptor/src/cap_acceptor_unicast.c

@@ -296,7 +296,6 @@ static void unicast_stream_enabled_cb(struct bt_bap_stream *bap_stream)
 static void unicast_stream_started_cb(struct bt_bap_stream *bap_stream)
 {
 	LOG_INF("Started bap_stream %p", bap_stream);
-	total_unicast_rx_iso_packet_count = 0U;
 }
 
 static void unicast_stream_metadata_updated_cb(struct bt_bap_stream *bap_stream)
@@ -438,7 +437,10 @@ int init_cap_acceptor_unicast(struct peer_config *peer)
 	}
 
 	bt_cap_stream_ops_register(&peer->source_stream, &unicast_stream_ops);
-	bt_cap_stream_ops_register(&peer->sink_stream, &unicast_stream_ops);
+
+	ARRAY_FOR_EACH_PTR(peer->sink_streams, stream) {
+		bt_cap_stream_ops_register(stream, &unicast_stream_ops);
+	}
 
 	if (IS_ENABLED(CONFIG_BT_ASCS_ASE_SRC)) {
 		static bool thread_started;
@@ -459,5 +461,8 @@ int init_cap_acceptor_unicast(struct peer_config *peer)
 	k_sem_init(&peer->source_stream_sem, 0, 1);
 	k_sem_init(&peer->sink_stream_sem, 0, 1);
 
+	total_unicast_rx_iso_packet_count = 0U;
+	total_unicast_tx_iso_packet_count = 0U;
+
 	return 0;
 }

samples/bluetooth/cap_acceptor/src/main.c

@@ -26,6 +26,7 @@
 #include <zephyr/kernel.h>
 #include <zephyr/logging/log.h>
 #include <zephyr/logging/log_core.h>
+#include <zephyr/sys/__assert.h>
 #include <zephyr/sys/util.h>
 #include <zephyr/sys/util_macro.h>
 
@@ -140,8 +141,12 @@ static int advertise(void)
 
 struct bt_cap_stream *stream_alloc(enum bt_audio_dir dir)
 {
-	if (dir == BT_AUDIO_DIR_SINK && peer.sink_stream.bap_stream.ep == NULL) {
-		return &peer.sink_stream;
+	if (dir == BT_AUDIO_DIR_SINK) {
+		ARRAY_FOR_EACH_PTR(peer.sink_streams, stream) {
+			if (stream->bap_stream.ep == NULL) {
+				return stream;
+			}
+		}
 	} else if (dir == BT_AUDIO_DIR_SOURCE && peer.source_stream.bap_stream.ep == NULL) {
 		return &peer.source_stream;
 	}
@@ -153,8 +158,10 @@ void stream_released(const struct bt_cap_stream *cap_stream)
 {
 	if (cap_stream == &peer.source_stream) {
 		k_sem_give(&peer.source_stream_sem);
-	} else if (cap_stream == &peer.sink_stream) {
+	} else if (IS_ARRAY_ELEMENT(peer.sink_streams, cap_stream)) {
 		k_sem_give(&peer.sink_stream_sem);
+	} else {
+		__ASSERT(false, "Invalid stream: %p", cap_stream);
 	}
 }
 
@@ -201,11 +208,13 @@ static int reset_cap_acceptor(void)
 		}
 	}
 
-	if (peer.sink_stream.bap_stream.ep != NULL) {
-		err = k_sem_take(&peer.sink_stream_sem, SEM_TIMEOUT);
-		if (err != 0) {
-			LOG_ERR("Timeout on sink_stream_sem: %d", err);
-			return err;
+	ARRAY_FOR_EACH_PTR(peer.sink_streams, stream) {
+		if (stream->bap_stream.ep != NULL) {
+			err = k_sem_take(&peer.sink_stream_sem, SEM_TIMEOUT);
+			if (err != 0) {
+				LOG_ERR("Timeout on sink_stream_sem: %d", err);
+				return err;
+			}
 		}
 	}
 

samples/bluetooth/cap_handover/CMakeLists.txt

@@ -0,0 +1,12 @@
+# SPDX-License-Identifier: Apache-2.0
+
+cmake_minimum_required(VERSION 3.20.0)
+find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
+project(cap_handover)
+
+target_sources(app PRIVATE
+  src/main.c
+  src/cap_stream_tx.c
+)
+
+zephyr_library_include_directories(${ZEPHYR_BASE}/samples/bluetooth)

samples/bluetooth/cap_handover/Kconfig

@@ -0,0 +1,21 @@
+# Copyright (c) 2024 Nordic Semiconductor ASA
+# SPDX-License-Identifier: Apache-2.0
+
+mainmenu "Bluetooth: Common Audio Profile initiator sample"
+
+config SAMPLE_STATIC_BROADCAST_ID
+	bool "Use static broadcast ID"
+	default y
+	help
+	   Enabling this option will make the application use static broadcast ID, as opposed to a
+	   randomly generated one.
+
+config SAMPLE_BROADCAST_ID
+	hex "The static broadcast ID to use"
+	range 0x000000 0xFFFFFF
+	depends on STATIC_BROADCAST_ID
+	default 0x123456
+	help
+	   This is the 3-octet broadcast ID advertised if static broadcast IDs are enabled.
+
+source "Kconfig.zephyr"

samples/bluetooth/cap_handover/Kconfig.sysbuild

@@ -0,0 +1,15 @@
+# Copyright 2023 Nordic Semiconductor ASA
+# SPDX-License-Identifier: Apache-2.0
+
+source "share/sysbuild/Kconfig"
+
+config NET_CORE_BOARD
+	string
+	default "nrf5340dk/nrf5340/cpunet" if "$(BOARD)" = "nrf5340dk"
+	default "nrf5340_audio_dk/nrf5340/cpunet" if "$(BOARD)" = "nrf5340_audio_dk"
+	default "nrf5340bsim/nrf5340/cpunet" if $(BOARD_TARGET_STRING) = "NRF5340BSIM_NRF5340_CPUAPP"
+
+config NET_CORE_IMAGE_HCI_IPC
+	bool "HCI IPC image on network core"
+	default y
+	depends on NET_CORE_BOARD != ""

samples/bluetooth/cap_handover/README.rst

@@ -0,0 +1,75 @@
+.. zephyr:code-sample:: bluetooth_cap_handover
+   :name: Common Audio Profile (CAP) Handover
+   :relevant-api: bluetooth bt_bap bt_cap bt_conn
+
+   Connects to a CAP acceptor and performs CAP handover procedures
+
+Overview
+********
+
+Application demonstrating the CAP handover functionality.
+Starts by scanning for a CAP Acceptor then sets up unicast audio, and then switches between unicast
+and broadcast using the CAP handover procedures.
+
+This sample can be found under :zephyr_file:`samples/bluetooth/cap_handover` in the Zephyr tree.
+
+Check the :zephyr:code-sample-category:`bluetooth` samples for general information.
+
+Requirements
+************
+
+* BlueZ running on the host, or
+* A board with Bluetooth Low Energy 5.2 support
+
+Building and Running
+********************
+
+When building targeting an nrf52 series board with the Zephyr Bluetooth Controller,
+use ``-DEXTRA_CONF_FILE=overlay-bt_ll_sw_split.conf`` to enable the required ISO
+feature support.
+
+Building for an nrf5340dk
+-------------------------
+
+You can build both the application core image and an appropriate controller image for the network
+core with:
+
+.. zephyr-app-commands::
+   :zephyr-app: samples/bluetooth/cap_handover/
+   :board: nrf5340dk/nrf5340/cpuapp
+   :goals: build
+   :west-args: --sysbuild
+
+If you prefer to only build the application core image, you can do so by doing instead:
+
+.. zephyr-app-commands::
+   :zephyr-app: samples/bluetooth/cap_handover/
+   :board: nrf5340dk/nrf5340/cpuapp
+   :goals: build
+
+In that case you can pair this application core image with the
+:zephyr:code-sample:`bluetooth_hci_ipc` sample
+:zephyr_file:`samples/bluetooth/hci_ipc/nrf5340_cpunet_iso-bt_ll_sw_split.conf` configuration.
+
+Building for a simulated nrf5340bsim
+------------------------------------
+
+Similarly to how you would for real HW, you can do:
+
+.. zephyr-app-commands::
+   :zephyr-app: samples/bluetooth/cap_handover/
+   :board: nrf5340bsim/nrf5340/cpuapp
+   :goals: build
+   :west-args: --sysbuild
+
+Note this will produce a Linux executable in :file:`./build/zephyr/zephyr.exe`.
+For more information, check :ref:`this board documentation <nrf5340bsim>`.
+
+Building for a simulated nrf52_bsim
+-----------------------------------
+
+.. zephyr-app-commands::
+   :zephyr-app: samples/bluetooth/cap_handover/
+   :board: nrf52_bsim
+   :goals: build
+   :gen-args: -DEXTRA_CONF_FILE=overlay-bt_ll_sw_split.conf