Bluetooth: ascs: Add dynamic ASE registration

Added option to set the ASE count through the bap API, making ASE
configuration runtime available. The upper limit of ASEs are still
bound by the Kconfig options set for ASEs.

Signed-off-by: Fredrik Danebjer <frdn@demant.com>

doc/connectivity/bluetooth/api/audio/shell/bap.rst

@@ -16,7 +16,7 @@ Commands
 
    bap --help
    Subcommands:
-      init
+      init                   : [ase_sink_count, ase_source_count]
       select_broadcast       : <stream>
       create_broadcast       : [preset <preset_name>] [enc <broadcast_code>]
       start_broadcast        :

doc/releases/migration-guide-4.0.rst

@@ -208,6 +208,19 @@ Bluetooth Audio
   This needs to be added to all instances of VCP Volume Renderer callback functions defined.
   (:github:`76992`)
 
+* The Unicast Server has a new registration function :c:func:`bt_bap_unicast_server_register` which
+  takes a :c:struct:`bt_bap_unicast_server_register_param` as argument. This allows the Unicast
+  Server to dynamically register Source and Sink ASE count at runtime. The old
+  :kconfig:option:`CONFIG_BT_ASCS_ASE_SRC_COUNT` and :kconfig:option:`CONFIG_BT_ASCS_ASE_SNK_COUNT`
+  has been renamed to :kconfig:option:`CONFIG_BT_ASCS_MAX_ASE_SRC_COUNT` and
+  :kconfig:option:`CONFIG_BT_ASCS_MAX_ASE_SNK_COUNT` to reflect that they now serve as a
+  compile-time maximum configuration of ASEs to be used.
+  :c:func:`bt_bap_unicast_server_register` needs to be called once before using the Unicast Server,
+  and more specfically prior to calling :c:func:`bt_bap_unicast_server_register_cb` for the first
+  time. It does not need to be called again until the new function
+  :c:func:`bt_bap_unicast_server_unregister` has been called.
+  (:github:`76632`)
+
 Bluetooth Classic
 =================
 

include/zephyr/bluetooth/audio/bap.h

@@ -635,6 +635,22 @@ struct bt_bap_stream_ops {
 	void (*disconnected)(struct bt_bap_stream *stream, uint8_t reason);
 };
 
+/** Structure for registering Unicast Server */
+struct bt_bap_unicast_server_register_param {
+	/**
+	 * @brief Sink Count to register.
+	 *
+	 * Should be in range [0, @kconfig{CONFIG_BT_ASCS_MAX_ASE_SNK_COUNT}]
+	 */
+	uint8_t snk_cnt;
+
+	/** @brief Source Count to register.
+	 *
+	 * Should be in range [0, @kconfig{CONFIG_BT_ASCS_MAX_ASE_SRC_COUNT}]
+	 */
+	uint8_t src_cnt;
+};
+
 /**
  * @brief Register Audio callbacks for a stream.
  *
@@ -1019,11 +1035,41 @@ struct bt_bap_unicast_server_cb {
 	int (*release)(struct bt_bap_stream *stream, struct bt_bap_ascs_rsp *rsp);
 };
 
+/**
+ * @brief Register the Unicast Server.
+ *
+ * Register the Unicast Server. Only a single Unicast Server can be registered at any one time.
+ * This will register ASCS in the GATT database.
+ *
+ * @param param  Registration parameters for ascs.
+ *
+ * @return 0 in case of success, negative error code otherwise.
+ */
+int bt_bap_unicast_server_register(const struct bt_bap_unicast_server_register_param *param);
+
+/**
+ * @brief Unregister the Unicast Server.
+ *
+ * Unregister the Unicast Server.
+ * This will unregister ASCS in the GATT database.
+ * Before calling this function, any callbacks registered through
+ * bt_bap_unicast_server_register_cb() needs to be unregistered with
+ * bt_bap_unicast_server_unregister_cb().
+ *
+ * Calling this function will issue an release operation on any ASE
+ * in a non-idle state.
+ *
+ * @return 0 in case of success, negative error code otherwise.
+ */
+int bt_bap_unicast_server_unregister(void);
+
 /**
  * @brief Register unicast server callbacks.
  *
  * Only one callback structure can be registered, and attempting to
  * registering more than one will result in an error.
+ * Prior to calling this function the Unicast Server needs to be
+ * registered with bt_bap_unicast_server_register().
  *
  * @param cb  Unicast server callback structure.
  *
@@ -1037,6 +1083,9 @@ int bt_bap_unicast_server_register_cb(const struct bt_bap_unicast_server_cb *cb)
  * May only unregister a callback structure that has previously been
  * registered by bt_bap_unicast_server_register_cb().
  *
+ * Calling this function will issue an release operation on any ASE
+ * in a non-idle state.
+ *
  * @param cb  Unicast server callback structure.
  *
  * @return 0 in case of success or negative value in case of error.

include/zephyr/bluetooth/audio/gmap.h

@@ -89,7 +89,7 @@ enum bt_gmap_ugt_feat {
 	/**
 	 * @brief Source support
 	 *
-	 * Requires @kconfig{CONFIG_BT_ASCS_ASE_SRC_COUNT} > 0
+	 * Requires @kconfig{CONFIG_BT_ASCS_MAX_ASE_SNK_COUNT} > 0
 	 */
 	BT_GMAP_UGT_FEAT_SOURCE = BIT(0),
 	/**
@@ -101,7 +101,7 @@ enum bt_gmap_ugt_feat {
 	/**
 	 * @brief Sink support
 	 *
-	 * Requires @kconfig{CONFIG_BT_ASCS_ASE_SNK_COUNT} > 0
+	 * Requires @kconfig{CONFIG_BT_ASCS_MAX_ASE_SNK_COUNT} > 0
 	 */
 	BT_GMAP_UGT_FEAT_SINK = BIT(2),
 	/**
@@ -119,14 +119,14 @@ enum bt_gmap_ugt_feat {
 	/**
 	 * @brief Support for receiving at least two audio channels, each in a separate CIS
 	 *
-	 * Requires @kconfig{CONFIG_BT_ASCS_ASE_SNK_COUNT} > 1 and
+	 * Requires @kconfig{CONFIG_BT_ASCS_MAX_ASE_SNK_COUNT} > 1 and
 	 * @kconfig{CONFIG_BT_ASCS_MAX_ACTIVE_ASES} > 1, and BT_GMAP_UGT_FEAT_SINK to be set as well
 	 */
 	BT_GMAP_UGT_FEAT_MULTISINK = BIT(5),
 	/**
 	 * @brief Support for sending at least two audio channels, each in a separate CIS
 	 *
-	 * Requires @kconfig{CONFIG_BT_ASCS_ASE_SRC_COUNT} > 1 and
+	 * Requires @kconfig{CONFIG_BT_ASCS_MAX_ASE_SNK_COUNT} > 1 and
 	 * @kconfig{CONFIG_BT_ASCS_MAX_ACTIVE_ASES} > 1, and BT_GMAP_UGT_FEAT_SOURCE to be set
 	 * as well
 	 */

samples/bluetooth/bap_unicast_server/prj.conf

@@ -5,8 +5,8 @@ CONFIG_BT_ISO_PERIPHERAL=y
 CONFIG_BT_AUDIO=y
 CONFIG_BT_BAP_UNICAST_SERVER=y
 CONFIG_BT_ASCS=y
-CONFIG_BT_ASCS_ASE_SNK_COUNT=2
-CONFIG_BT_ASCS_ASE_SRC_COUNT=1
+CONFIG_BT_ASCS_MAX_ASE_SNK_COUNT=2
+CONFIG_BT_ASCS_MAX_ASE_SRC_COUNT=1
 CONFIG_BT_ISO_TX_BUF_COUNT=2
 # Support an ISO channel per ASE
 CONFIG_BT_ISO_MAX_CHAN=4

samples/bluetooth/bap_unicast_server/src/main.c

@@ -29,7 +29,7 @@
 				  BT_AUDIO_CONTEXT_TYPE_MEDIA | \
 				  BT_AUDIO_CONTEXT_TYPE_GAME)
 
-NET_BUF_POOL_FIXED_DEFINE(tx_pool, CONFIG_BT_ASCS_ASE_SRC_COUNT,
+NET_BUF_POOL_FIXED_DEFINE(tx_pool, CONFIG_BT_ASCS_MAX_ASE_SRC_COUNT,
 			  BT_ISO_SDU_BUF_SIZE(CONFIG_BT_ISO_TX_MTU),
 			  CONFIG_BT_CONN_TX_USER_DATA_SIZE, NULL);
 
@@ -40,13 +40,13 @@ static const struct bt_audio_codec_cap lc3_codec_cap = BT_AUDIO_CODEC_CAP_LC3(
 
 static struct bt_conn *default_conn;
 static struct k_work_delayable audio_send_work;
-static struct bt_bap_stream sink_streams[CONFIG_BT_ASCS_ASE_SNK_COUNT];
+static struct bt_bap_stream sink_streams[CONFIG_BT_ASCS_MAX_ASE_SNK_COUNT];
 static struct audio_source {
 	struct bt_bap_stream stream;
 	uint16_t seq_num;
 	uint16_t max_sdu;
 	size_t len_to_send;
-} source_streams[CONFIG_BT_ASCS_ASE_SRC_COUNT];
+} source_streams[CONFIG_BT_ASCS_MAX_ASE_SRC_COUNT];
 static size_t configured_source_stream_count;
 
 static const struct bt_audio_codec_qos_pref qos_pref =
@@ -466,6 +466,11 @@ static int lc3_release(struct bt_bap_stream *stream, struct bt_bap_ascs_rsp *rsp
 	return 0;
 }
 
+static struct bt_bap_unicast_server_register_param param = {
+	CONFIG_BT_ASCS_MAX_ASE_SNK_COUNT,
+	CONFIG_BT_ASCS_MAX_ASE_SRC_COUNT
+};
+
 static const struct bt_bap_unicast_server_cb unicast_server_cb = {
 	.config = lc3_config,
 	.reconfig = lc3_reconfig,
@@ -727,6 +732,7 @@ int main(void)
 
 	printk("Bluetooth initialized\n");
 
+	bt_bap_unicast_server_register(&param);
 	bt_bap_unicast_server_register_cb(&unicast_server_cb);
 
 	bt_pacs_cap_register(BT_AUDIO_DIR_SINK, &cap_sink);
@@ -780,7 +786,7 @@ int main(void)
 
 		printk("Advertising successfully started\n");
 
-		if (CONFIG_BT_ASCS_ASE_SRC_COUNT > 0) {
+		if (CONFIG_BT_ASCS_MAX_ASE_SRC_COUNT > 0) {
 			/* Start send timer */
 			k_work_init_delayable(&audio_send_work, audio_timer_timeout);
 		}

samples/bluetooth/cap_acceptor/prj.conf

@@ -23,8 +23,8 @@ CONFIG_BT_ATT_PREPARE_COUNT=1
 
 # Support an ISO channel per ASE
 CONFIG_BT_ASCS=y
-CONFIG_BT_ASCS_ASE_SNK_COUNT=1
-CONFIG_BT_ASCS_ASE_SRC_COUNT=1
+CONFIG_BT_ASCS_MAX_ASE_SNK_COUNT=1
+CONFIG_BT_ASCS_MAX_ASE_SRC_COUNT=1
 
 # Support an ISO channel per ASE
 CONFIG_BT_ISO_MAX_CHAN=2

samples/bluetooth/cap_acceptor/src/cap_acceptor_unicast.c

@@ -402,6 +402,17 @@ int init_cap_acceptor_unicast(struct peer_config *peer)
 
 	if (!cbs_registered) {
 		int err;
+		struct bt_bap_unicast_server_register_param param = {
+			CONFIG_BT_ASCS_MAX_ASE_SNK_COUNT,
+			CONFIG_BT_ASCS_MAX_ASE_SRC_COUNT
+		};
+
+		err = bt_bap_unicast_server_register(&param);
+		if (err != 0) {
+			LOG_ERR("Failed to register BAP unicast server: %d", err);
+
+			return -ENOEXEC;
+		}
 
 		err = bt_bap_unicast_server_register_cb(&unicast_server_cb);
 		if (err != 0) {

samples/bluetooth/hap_ha/prj.conf

@@ -18,8 +18,8 @@ CONFIG_BT_ATT_PREPARE_COUNT=1
 CONFIG_BT_AUDIO=y
 CONFIG_BT_BAP_UNICAST_SERVER=y
 CONFIG_BT_ASCS=y
-CONFIG_BT_ASCS_ASE_SNK_COUNT=1
-CONFIG_BT_ASCS_ASE_SRC_COUNT=1
+CONFIG_BT_ASCS_MAX_ASE_SNK_COUNT=1
+CONFIG_BT_ASCS_MAX_ASE_SRC_COUNT=1
 # Support an ISO channel per ASE
 CONFIG_BT_ISO_MAX_CHAN=2
 

samples/bluetooth/hap_ha/src/bap_unicast_sr.c

@@ -18,7 +18,7 @@
 #include <zephyr/bluetooth/audio/bap.h>
 #include <zephyr/bluetooth/audio/pacs.h>
 
-NET_BUF_POOL_FIXED_DEFINE(tx_pool, CONFIG_BT_ASCS_ASE_SRC_COUNT,
+NET_BUF_POOL_FIXED_DEFINE(tx_pool, CONFIG_BT_ASCS_MAX_ASE_SRC_COUNT,
 			  BT_ISO_SDU_BUF_SIZE(CONFIG_BT_ISO_TX_MTU),
 			  CONFIG_BT_CONN_TX_USER_DATA_SIZE, NULL);
 
@@ -29,11 +29,12 @@ static const struct bt_audio_codec_cap lc3_codec_cap = BT_AUDIO_CODEC_CAP_LC3(
 
 static struct bt_conn *default_conn;
 static struct k_work_delayable audio_send_work;
-static struct bt_bap_stream streams[CONFIG_BT_ASCS_ASE_SNK_COUNT + CONFIG_BT_ASCS_ASE_SRC_COUNT];
+static struct bt_bap_stream streams[CONFIG_BT_ASCS_MAX_ASE_SNK_COUNT +
+				    CONFIG_BT_ASCS_MAX_ASE_SRC_COUNT];
 static struct audio_source {
 	struct bt_bap_stream *stream;
 	uint16_t seq_num;
-} source_streams[CONFIG_BT_ASCS_ASE_SRC_COUNT];
+} source_streams[CONFIG_BT_ASCS_MAX_ASE_SRC_COUNT];
 static size_t configured_source_stream_count;
 
 static const struct bt_audio_codec_qos_pref qos_pref =
@@ -316,6 +317,11 @@ static int lc3_release(struct bt_bap_stream *stream, struct bt_bap_ascs_rsp *rsp
 	return 0;
 }
 
+static struct bt_bap_unicast_server_register_param param = {
+	CONFIG_BT_ASCS_MAX_ASE_SNK_COUNT,
+	CONFIG_BT_ASCS_MAX_ASE_SRC_COUNT
+};
+
 static const struct bt_bap_unicast_server_cb unicast_server_cb = {
 	.config = lc3_config,
 	.reconfig = lc3_reconfig,
@@ -394,6 +400,7 @@ static struct bt_pacs_cap cap_source = {
 
 int bap_unicast_sr_init(void)
 {
+	bt_bap_unicast_server_register(&param);
 	bt_bap_unicast_server_register_cb(&unicast_server_cb);
 
 	bt_pacs_cap_register(BT_AUDIO_DIR_SINK, &cap_sink);

samples/bluetooth/tmap_peripheral/prj.conf

@@ -29,8 +29,8 @@ CONFIG_BT_MCC=y
 
 # Support an ISO channel per ASE
 CONFIG_BT_ASCS=y
-CONFIG_BT_ASCS_ASE_SNK_COUNT=1
-CONFIG_BT_ASCS_ASE_SRC_COUNT=1
+CONFIG_BT_ASCS_MAX_ASE_SNK_COUNT=1
+CONFIG_BT_ASCS_MAX_ASE_SRC_COUNT=1
 # Support an ISO channel per ASE
 CONFIG_BT_ISO_MAX_CHAN=2
 

samples/bluetooth/tmap_peripheral/src/bap_unicast_sr.c

@@ -30,11 +30,12 @@ static const struct bt_audio_codec_cap lc3_codec_cap =
 			       (AVAILABLE_SINK_CONTEXT | AVAILABLE_SOURCE_CONTEXT));
 
 static struct bt_conn *default_conn;
-static struct bt_bap_stream streams[CONFIG_BT_ASCS_ASE_SNK_COUNT + CONFIG_BT_ASCS_ASE_SRC_COUNT];
+static struct bt_bap_stream streams[CONFIG_BT_ASCS_MAX_ASE_SNK_COUNT +
+				    CONFIG_BT_ASCS_MAX_ASE_SRC_COUNT];
 static struct audio_source {
 	struct bt_bap_stream *stream;
 	uint16_t seq_num;
-} source_streams[CONFIG_BT_ASCS_ASE_SRC_COUNT];
+} source_streams[CONFIG_BT_ASCS_MAX_ASE_SRC_COUNT];
 static size_t configured_source_stream_count;
 
 static const struct bt_audio_codec_qos_pref qos_pref =
@@ -271,6 +272,11 @@ static int lc3_release(struct bt_bap_stream *stream, struct bt_bap_ascs_rsp *rsp
 	return 0;
 }
 
+static struct bt_bap_unicast_server_register_param param = {
+	CONFIG_BT_ASCS_MAX_ASE_SNK_COUNT,
+	CONFIG_BT_ASCS_MAX_ASE_SRC_COUNT
+};
+
 static const struct bt_bap_unicast_server_cb unicast_server_cb = {
 	.config = lc3_config,
 	.reconfig = lc3_reconfig,
@@ -351,6 +357,7 @@ static struct bt_pacs_cap cap = {
 
 int bap_unicast_sr_init(void)
 {
+	bt_bap_unicast_server_register(&param);
 	bt_bap_unicast_server_register_cb(&unicast_server_cb);
 
 	if (IS_ENABLED(CONFIG_BT_PAC_SNK)) {

subsys/bluetooth/audio/Kconfig.ascs

@@ -12,29 +12,29 @@ config BT_ASCS
 	  This option enables support for Audio Stream Control Service.
 
 if BT_ASCS
-config BT_ASCS_ASE_SNK_COUNT
-	int "Number of Audio Stream Endpoint Sink Characteristics"
+config BT_ASCS_MAX_ASE_SNK_COUNT
+	int "Maximum number of Audio Stream Endpoint Sink Characteristics"
 	default 2
 	range 0 $(UINT8_MAX)
 	help
 	  An ASE Sink characteristic represents the state of an ASE, which is
 	  coupled to a single direction of a unicast Audio Stream.
 
-config BT_ASCS_ASE_SRC_COUNT
-	int "Number of Audio Stream Endpoint Source Characteristics"
+config BT_ASCS_MAX_ASE_SRC_COUNT
+	int "Maximum number of Audio Stream Endpoint Source Characteristics"
 	default 2
 	range 0 $(UINT8_MAX)
 	help
 	  An ASE Source characteristic represents the state of an ASE, which is
 	  coupled to a single direction of a unicast Audio Stream.
 
 config BT_ASCS_ASE_SNK
-	def_bool BT_ASCS_ASE_SNK_COUNT > 0
+	def_bool BT_ASCS_MAX_ASE_SNK_COUNT > 0
 	select BT_PAC_SNK
 	select BT_AUDIO_RX
 
 config BT_ASCS_ASE_SRC
-	def_bool BT_ASCS_ASE_SRC_COUNT > 0
+	def_bool BT_ASCS_MAX_ASE_SRC_COUNT > 0
 	select BT_PAC_SRC
 	select BT_AUDIO_TX