samples: Bluetooth: Add broadcast audio source sample

Add a sample using the Basic Audio Profile (BAP)
broadcast source role, that advertises mock audio
data over ISO.

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

samples/bluetooth/broadcast_audio_source/CMakeLists.txt

@@ -0,0 +1,11 @@
+# SPDX-License-Identifier: Apache-2.0
+
+cmake_minimum_required(VERSION 3.20.0)
+find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
+project(unicast_audio_server)
+
+target_sources(app PRIVATE
+  src/main.c
+)
+
+zephyr_library_include_directories(${ZEPHYR_BASE}/samples/bluetooth)

samples/bluetooth/broadcast_audio_source/README.rst

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+.. _bluetooth_broadcast_audio_source:
+
+Bluetooth: Broadcast Audio Source
+#################################
+
+Overview
+********
+
+Application demonstrating the LE Audio broadcast audio source functionality.
+Will start advertising extended advertising with audio flags, periodic advertising with the
+broadcast audio source endpoint (BASE) and finally the BIGinfo together with
+(mock) Audio (ISO) data.
+
+The broadcast source will reset every 30 seconds to show the full API.
+
+Requirements
+************
+
+* BlueZ running on the host, or
+* A board with Bluetooth Low Energy 5.2 support
+
+Building and Running
+********************
+This sample can be found under
+:zephyr_file:`samples/bluetooth/broadcast_audio_source` in the Zephyr tree.
+
+See :ref:`bluetooth samples section <bluetooth-samples>` for details.

samples/bluetooth/broadcast_audio_source/boards/nrf52840dk_nrf52840.conf

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+CONFIG_BT_CTLR_ADV_EXT=y
+CONFIG_BT_CTLR_ADV_PERIODIC=y
+CONFIG_BT_CTLR_ADV_ISO=y

samples/bluetooth/broadcast_audio_source/boards/nrf5340dk_nrf5340_cpuapp.conf

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+CONFIG_BT_CTLR_ADV_EXT=y
+CONFIG_BT_CTLR_ADV_PERIODIC=y
+CONFIG_BT_CTLR_ADV_ISO=y

samples/bluetooth/broadcast_audio_source/prj.conf

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+CONFIG_BT=y
+CONFIG_BT_DEBUG_LOG=y
+CONFIG_BT_AUDIO=y
+CONFIG_BT_AUDIO_BROADCAST_SOURCE=y
+
+CONFIG_BT_AUDIO_BROADCAST_SRC_STREAM_COUNT=1
+CONFIG_BT_ISO_TX_BUF_COUNT=2
+
+CONFIG_BT_DEVICE_NAME="Broadcast Audio Source"

samples/bluetooth/broadcast_audio_source/sample.yaml

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+sample:
+  description: Bluetooth Low Energy Broadcast Audio Source sample
+  name: Bluetooth Low Energy Broadcast Audio Source sample
+tests:
+  sample.bluetooth.broadcast_audio_source:
+    harness: bluetooth
+    platform_allow: qemu_cortex_m3 qemu_x86 nrf52_bsim
+    tags: bluetooth

samples/bluetooth/broadcast_audio_source/src/main.c

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+/*
+ * Copyright (c) 2022 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <bluetooth/bluetooth.h>
+#include <bluetooth/audio/audio.h>
+
+/* When BROADCAST_ENQUEUE_COUNT > 1 we can enqueue enough buffers to ensure that
+ * the controller is never idle
+ */
+#define BROADCAST_ENQUEUE_COUNT 2U
+#define TOTAL_BUF_NEEDED (BROADCAST_ENQUEUE_COUNT * CONFIG_BT_AUDIO_BROADCAST_SRC_STREAM_COUNT)
+
+BUILD_ASSERT(CONFIG_BT_ISO_TX_BUF_COUNT >= TOTAL_BUF_NEEDED,
+	     "CONFIG_BT_ISO_TX_BUF_COUNT should be at least "
+	     "BROADCAST_ENQUEUE_COUNT * CONFIG_BT_AUDIO_BROADCAST_SRC_STREAM_COUNT");
+
+static struct bt_audio_lc3_preset preset_16_2_1 = BT_AUDIO_LC3_BROADCAST_PRESET_16_2_1;
+static struct bt_audio_stream streams[CONFIG_BT_AUDIO_BROADCAST_SRC_STREAM_COUNT];
+static struct bt_audio_broadcast_source *broadcast_source;
+
+NET_BUF_POOL_FIXED_DEFINE(tx_pool,
+			  TOTAL_BUF_NEEDED,
+			  BT_ISO_SDU_BUF_SIZE(CONFIG_BT_ISO_TX_MTU), 8, NULL);
+static uint8_t mock_data[CONFIG_BT_ISO_TX_MTU];
+static bool stopping;
+
+static K_SEM_DEFINE(sem_started, 0U, ARRAY_SIZE(streams));
+static K_SEM_DEFINE(sem_stopped, 0U, ARRAY_SIZE(streams));
+
+#define BROADCAST_SOURCE_LIFETIME  30U /* seconds */
+
+static void stream_started_cb(struct bt_audio_stream *stream)
+{
+	k_sem_give(&sem_started);
+}
+
+static void stream_stopped_cb(struct bt_audio_stream *stream)
+{
+	k_sem_give(&sem_stopped);
+}
+
+static void stream_sent_cb(struct bt_audio_stream *stream)
+{
+	static uint32_t sent_cnt;
+	struct net_buf *buf;
+	int ret;
+
+	if (stopping) {
+		return;
+	}
+
+	buf = net_buf_alloc(&tx_pool, K_FOREVER);
+	if (buf == NULL) {
+		printk("Could not allocate buffer when sending on %p\n",
+		       stream);
+		return;
+	}
+
+	net_buf_reserve(buf, BT_ISO_CHAN_SEND_RESERVE);
+	net_buf_add_mem(buf, mock_data, preset_16_2_1.qos.sdu);
+	ret = bt_audio_stream_send(stream, buf);
+	if (ret < 0) {
+		/* This will end broadcasting on this stream. */
+		printk("Unable to broadcast data on %p: %d\n", stream, ret);
+		net_buf_unref(buf);
+		return;
+	}
+
+	sent_cnt++;
+	if ((sent_cnt % 1000U) == 0U) {
+		printk("Sent %u total ISO packets\n", sent_cnt);
+	}
+}
+
+struct bt_audio_stream_ops stream_ops = {
+	.started = stream_started_cb,
+	.stopped = stream_stopped_cb,
+	.sent = stream_sent_cb
+};
+
+void main(void)
+{
+	int err;
+
+	err = bt_enable(NULL);
+	if (err) {
+		printk("Bluetooth init failed (err %d)\n", err);
+		return;
+	}
+	printk("Bluetooth initialized\n");
+
+	for (size_t i = 0U; i < ARRAY_SIZE(streams); i++) {
+		streams[i].ops = &stream_ops;
+	}
+
+	for (size_t i = 0U; i < ARRAY_SIZE(mock_data); i++) {
+		/* Initialize mock data */
+		mock_data[i] = i;
+	}
+
+	while (true) {
+		printk("Creating broadcast source\n");
+		err = bt_audio_broadcast_source_create(streams,
+						       ARRAY_SIZE(streams),
+						       &preset_16_2_1.codec,
+						       &preset_16_2_1.qos,
+						       &broadcast_source);
+		if (err != 0) {
+			printk("Unable to create broadcast source: %d\n", err);
+			return;
+		}
+
+		printk("Starting broadcast source\n");
+		stopping = false;
+		err = bt_audio_broadcast_source_start(broadcast_source);
+		if (err != 0) {
+			printk("Unable to start broadcast source: %d\n", err);
+			return;
+		}
+
+		/* Wait for all to be started */
+		for (size_t i = 0U; i < ARRAY_SIZE(streams); i++) {
+			k_sem_take(&sem_started, K_FOREVER);
+		}
+		printk("Broadcast source started\n");
+
+		/* Initialize sending */
+		for (size_t i = 0U; i < ARRAY_SIZE(streams); i++) {
+			for (unsigned int j = 0U; j < BROADCAST_ENQUEUE_COUNT; j++) {
+				stream_sent_cb(&streams[i]);
+			}
+		}
+
+		printk("Waiting %u seconds before stopped\n",
+		       BROADCAST_SOURCE_LIFETIME);
+		k_sleep(K_SECONDS(BROADCAST_SOURCE_LIFETIME));
+
+		printk("Stopping broadcast source\n");
+		stopping = true;
+		err = bt_audio_broadcast_source_stop(broadcast_source);
+		if (err != 0) {
+			printk("Unable to stop broadcast source: %d\n", err);
+			return;
+		}
+
+		/* Wait for all to be stopped */
+		for (size_t i = 0U; i < ARRAY_SIZE(streams); i++) {
+			k_sem_take(&sem_stopped, K_FOREVER);
+		}
+		printk("Broadcast source stopped\n");
+
+		printk("Deleting broadcast source\n");
+		err = bt_audio_broadcast_source_delete(broadcast_source);
+		if (err != 0) {
+			printk("Unable to delete broadcast source: %d\n", err);
+			return;
+		}
+		printk("Broadcast source deleted\n");
+		broadcast_source = NULL;
+	}
+}