add basic support for SCO packets over USB

apps/controller_info.py

@@ -45,8 +45,10 @@ from bumble.hci import (
     HCI_Read_Local_Supported_Codecs_Command,
     HCI_Read_Local_Supported_Codecs_V2_Command,
     HCI_Read_Local_Version_Information_Command,
+    HCI_Read_Voice_Setting_Command,
     LeFeature,
     SpecificationVersion,
+    VoiceSetting,
     map_null_terminated_utf8_string,
 )
 from bumble.host import Host
@@ -214,6 +216,16 @@ async def get_codecs_info(host: Host) -> None:
         if not response2.vendor_specific_codec_ids:
             print('  No Vendor-specific codecs')
 
+    if host.supports_command(HCI_Read_Voice_Setting_Command.op_code):
+        response3 = await host.send_sync_command(HCI_Read_Voice_Setting_Command())
+        voice_setting = VoiceSetting.from_int(response3.voice_setting)
+        print(color('Voice Setting:', 'yellow'))
+        print(f'  Air Coding Format:       {voice_setting.air_coding_format.name}')
+        print(f'  Linear PCM Bit Position: {voice_setting.linear_pcm_bit_position}')
+        print(f'  Input Sample Size:       {voice_setting.input_sample_size.name}')
+        print(f'  Input Data Format:       {voice_setting.input_data_format.name}')
+        print(f'  Input Coding Format:     {voice_setting.input_coding_format.name}')
+
 
 # -----------------------------------------------------------------------------
 async def async_main(

apps/controller_loopback.py

@@ -16,6 +16,8 @@
 # Imports
 # -----------------------------------------------------------------------------
 import asyncio
+import statistics
+import struct
 import time
 
 import click
@@ -25,7 +27,9 @@ from bumble.colors import color
 from bumble.hci import (
     HCI_READ_LOOPBACK_MODE_COMMAND,
     HCI_WRITE_LOOPBACK_MODE_COMMAND,
+    Address,
     HCI_Read_Loopback_Mode_Command,
+    HCI_SynchronousDataPacket,
     HCI_Write_Loopback_Mode_Command,
     LoopbackMode,
 )
@@ -36,34 +40,59 @@ from bumble.transport import open_transport
 class Loopback:
     """Send and receive ACL data packets in local loopback mode"""
 
-    def __init__(self, packet_size: int, packet_count: int, transport: str):
+    def __init__(
+        self,
+        packet_size: int,
+        packet_count: int,
+        connection_type: str,
+        mode: str,
+        interval: int,
+        transport: str,
+    ):
         self.transport = transport
         self.packet_size = packet_size
         self.packet_count = packet_count
         self.connection_handle: int | None = None
+        self.connection_type = connection_type
         self.connection_event = asyncio.Event()
+        self.mode = mode
+        self.interval = interval
         self.done = asyncio.Event()
-        self.expected_cid = 0
+        self.expected_counter = 0
         self.bytes_received = 0
         self.start_timestamp = 0.0
         self.last_timestamp = 0.0
+        self.send_timestamps: list[float] = []
+        self.rtts: list[float] = []
 
     def on_connection(self, connection_handle: int, *args):
         """Retrieve connection handle from new connection event"""
         if not self.connection_event.is_set():
-            # save first connection handle for ACL
-            # subsequent connections are SCO
+            # The first connection handle is of type ACL,
+            # subsequent connections are of type SCO
+            if self.connection_type == "sco" and self.connection_handle is None:
+                self.connection_handle = connection_handle
+                return
+
             self.connection_handle = connection_handle
             self.connection_event.set()
 
+    def on_sco_connection(
+        self, address: Address, connection_handle: int, link_type: int
+    ):
+        self.on_connection(connection_handle)
+
     def on_l2cap_pdu(self, connection_handle: int, cid: int, pdu: bytes):
         """Calculate packet receive speed"""
         now = time.time()
-        print(f'<<< Received packet {cid}: {len(pdu)} bytes')
+        (counter,) = struct.unpack_from("H", pdu, 0)
+        rtt = now - self.send_timestamps[counter]
+        self.rtts.append(rtt)
+        print(f'<<< Received packet {counter}: {len(pdu)} bytes, RTT={rtt:.4f}')
         assert connection_handle == self.connection_handle
-        assert cid == self.expected_cid
-        self.expected_cid += 1
-        if cid == 0:
+        assert counter == self.expected_counter
+        self.expected_counter += 1
+        if counter == 0:
             self.start_timestamp = now
         else:
             elapsed_since_start = now - self.start_timestamp
@@ -71,20 +100,52 @@ class Loopback:
             self.bytes_received += len(pdu)
             instant_rx_speed = len(pdu) / elapsed_since_last
             average_rx_speed = self.bytes_received / elapsed_since_start
-            print(
-                color(
-                    f'@@@ RX speed: instant={instant_rx_speed:.4f},'
-                    f' average={average_rx_speed:.4f}',
-                    'cyan',
+            if self.mode == 'throughput':
+                print(
+                    color(
+                        f'@@@ RX speed: instant={instant_rx_speed:.4f},'
+                        f' average={average_rx_speed:.4f},',
+                        'cyan',
+                    )
                 )
-            )
 
         self.last_timestamp = now
 
-        if self.expected_cid == self.packet_count:
+        if self.expected_counter == self.packet_count:
             print(color('@@@ Received last packet', 'green'))
             self.done.set()
 
+    def on_sco_packet(self, connection_handle: int, packet) -> None:
+        print("---", connection_handle, packet)
+
+    async def send_acl_packet(self, host: Host, packet: bytes) -> None:
+        assert self.connection_handle
+        host.send_l2cap_pdu(self.connection_handle, 0, packet)
+
+    async def send_sco_packet(self, host: Host, packet: bytes) -> None:
+        assert self.connection_handle
+        host.send_hci_packet(
+            HCI_SynchronousDataPacket(
+                connection_handle=self.connection_handle,
+                packet_status=HCI_SynchronousDataPacket.Status.CORRECTLY_RECEIVED_DATA,
+                data_total_length=len(packet),
+                data=packet,
+            )
+        )
+
+    async def send_loop(self, host: Host, sender) -> None:
+        for counter in range(0, self.packet_count):
+            print(
+                color(
+                    f'>>> Sending {self.connection_type.upper()} '
+                    f'packet {counter}: {self.packet_size} bytes',
+                    'yellow',
+                )
+            )
+            self.send_timestamps.append(time.time())
+            await sender(host, struct.pack("H", counter) + bytes(self.packet_size - 2))
+            await asyncio.sleep(self.interval / 1000 if self.mode == "rtt" else 0)
+
     async def run(self) -> None:
         """Run a loopback throughput test"""
         print(color('>>> Connecting to HCI...', 'green'))
@@ -126,8 +187,11 @@ class Loopback:
                 return
 
             # set event callbacks
-            host.on('connection', self.on_connection)
+            host.on('classic_connection', self.on_connection)
+            host.on('le_connection', self.on_connection)
+            host.on('sco_connection', self.on_sco_connection)
             host.on('l2cap_pdu', self.on_l2cap_pdu)
+            host.on('sco_packet', self.on_sco_packet)
 
             loopback_mode = LoopbackMode.LOCAL
 
@@ -148,32 +212,37 @@ class Loopback:
 
             print(color('=== Start sending', 'magenta'))
             start_time = time.time()
-            bytes_sent = 0
-            for cid in range(0, self.packet_count):
-                # using the cid as an incremental index
-                host.send_l2cap_pdu(
-                    self.connection_handle, cid, bytes(self.packet_size)
-                )
-                print(
-                    color(
-                        f'>>> Sending packet {cid}: {self.packet_size} bytes', 'yellow'
-                    )
-                )
-                bytes_sent += self.packet_size  # don't count L2CAP or HCI header sizes
-                await asyncio.sleep(0)  # yield to allow packet receive
+            if self.connection_type == "acl":
+                sender = self.send_acl_packet
+            elif self.connection_type == "sco":
+                sender = self.send_sco_packet
+            else:
+                raise ValueError(f'Unknown connection type: {self.connection_type}')
+            await self.send_loop(host, sender)
 
             await self.done.wait()
             print(color('=== Done!', 'magenta'))
 
+            bytes_sent = self.packet_size * self.packet_count
             elapsed = time.time() - start_time
             average_tx_speed = bytes_sent / elapsed
-            print(
-                color(
-                    f'@@@ TX speed: average={average_tx_speed:.4f} ({bytes_sent} bytes'
-                    f' in {elapsed:.2f} seconds)',
-                    'green',
+            if self.mode == 'throughput':
+                print(
+                    color(
+                        f'@@@ TX speed: average={average_tx_speed:.4f} '
+                        f'({bytes_sent} bytes in {elapsed:.2f} seconds)',
+                        'green',
+                    )
+                )
+            if self.mode == 'rtt':
+                print(
+                    color(
+                        f'RTTs: min={min(self.rtts):.4f}, '
+                        f'max={max(self.rtts):.4f}, '
+                        f'avg={statistics.mean(self.rtts):.4f}',
+                        'blue',
+                    )
                 )
-            )
 
 
 # -----------------------------------------------------------------------------
@@ -194,11 +263,43 @@ class Loopback:
     default=10,
     help='Packet count',
 )
+@click.option(
+    '--connection-type',
+    '-t',
+    metavar='TYPE',
+    type=click.Choice(['acl', 'sco']),
+    default='acl',
+    help='Connection type',
+)
+@click.option(
+    '--mode',
+    '-m',
+    metavar='MODE',
+    type=click.Choice(['throughput', 'rtt']),
+    default='throughput',
+    help='Test mode',
+)
+@click.option(
+    '--interval',
+    type=int,
+    default=100,
+    help='Inter-packet interval (ms) [RTT mode only]',
+)
 @click.argument('transport')
-def main(packet_size, packet_count, transport):
+def main(packet_size, packet_count, connection_type, mode, interval, transport):
     bumble.logging.setup_basic_logging()
-    loopback = Loopback(packet_size, packet_count, transport)
-    asyncio.run(loopback.run())
+
+    if connection_type == "sco" and packet_size > 255:
+        print("ERROR: the maximum packet size for SCO is 255")
+        return
+
+    async def run():
+        loopback = Loopback(
+            packet_size, packet_count, connection_type, mode, interval, transport
+        )
+        await loopback.run()
+
+    asyncio.run(run())
 
 
 # -----------------------------------------------------------------------------

apps/usb_probe.py

@@ -111,9 +111,14 @@ def show_device_details(device):
                         if (endpoint.getAddress() & USB_ENDPOINT_IN == 0)
                         else 'IN'
                     )
+                    endpoint_details = (
+                        f', Max Packet Size = {endpoint.getMaxPacketSize()}'
+                        if endpoint_type == 'ISOCHRONOUS'
+                        else ''
+                    )
                     print(
                         f'        Endpoint 0x{endpoint.getAddress():02X}: '
-                        f'{endpoint_type} {endpoint_direction}'
+                        f'{endpoint_type} {endpoint_direction}{endpoint_details}'
                     )