samples: Add USB Audio to broadcast audio source

Adds support for using a connected host to
broadcast audio via USB Audio.

Sets BT_DATA_BROADCAST_NAME to BT_DEVICE_NAME
for discovery on receivers not using BT_DEVICE_NAME.

Offload LC3 encoding to separate thread.

Limits streams to one channel.

Signed-off-by: Lars Knudsen <[email protected]>

samples/bluetooth/broadcast_audio_source/boards/nrf5340_audio_dk_nrf5340_cpuapp.conf

@@ -1,12 +1,28 @@
 # For LC3 the following configs are needed
 CONFIG_FPU=y
 CONFIG_LIBLC3=y
+
 # When Host is fixed, CONFIG_BT_CTLR_ISO_TX_BUFFER_SIZE can inherit the CONFIG_BT_ISO_TX_MTU value.
-CONFIG_BT_ISO_TX_MTU=40
-# The LC3 codec uses a large amount of stack. This app runs the codec in the work-queue, hence
-# inctease stack size for that thread.
-CONFIG_SYSTEM_WORKQUEUE_STACK_SIZE=4096
+CONFIG_BT_ISO_TX_MTU=60
+
 # LC3 lib requires floating point support in the c-lib NEWLIB is one way of getting that.
 CONFIG_NEWLIB_LIBC=y
 CONFIG_MAIN_STACK_SIZE=4096
+
+# USB Audio related configs
+CONFIG_USB_DEVICE_STACK=y
+CONFIG_USB_DEVICE_PRODUCT="Zephyr Broadcast Source"
+CONFIG_USB_DEVICE_INITIALIZE_AT_BOOT=n
+CONFIG_USB_DEVICE_AUDIO=y
+
+# Two streams in one subgroup
+CONFIG_BT_ISO_MAX_CHAN=2
+CONFIG_BT_BAP_BROADCAST_SRC_STREAM_COUNT=2
+CONFIG_BT_BAP_BROADCAST_SRC_SUBGROUP_COUNT=1
+
+# Audio buffer
+CONFIG_RING_BUFFER=y
+
+# Additional BT settings
+CONFIG_BT_ECC=y
 CONFIG_BT_TINYCRYPT_ECC=y