add support for alternate settings

bumble/transport/usb.py

@@ -251,7 +251,7 @@ async def open_usb_transport(spec):
             await self.event_loop_done
 
     class UsbTransport(Transport):
-        def __init__(self, context, device, interface, source, sink):
+        def __init__(self, context, device, interface, setting, source, sink):
             super().__init__(source, sink)
             self.context   = context
             self.device    = device
@@ -260,6 +260,10 @@ async def open_usb_transport(spec):
             # Get exclusive access
             device.claimInterface(interface)
 
+            # Set the alternate setting if not the default
+            if setting != 0:
+                device.setInterfaceAltSetting(interface, setting)
+
             # The source and sink can now start
             source.start()
             sink.start()
@@ -317,13 +321,20 @@ async def open_usb_transport(spec):
 
         logger.debug(f'USB Device: {found}')
 
-        # Look for an interface and setting with the right types of endpoints
+        # Look for the first interface with the right class and endpoints
         def find_endpoints(device):
             for (configuration_index, configuration) in enumerate(device):
                 interface = None
                 for interface in configuration:
                     setting = None
                     for setting in interface:
+                        if (
+                            setting.getClass() != USB_DEVICE_CLASS_WIRELESS_CONTROLLER or
+                            setting.getSubClass() != USB_DEVICE_SUBCLASS_RF_CONTROLLER or
+                            setting.getProtocol() != USB_DEVICE_PROTOCOL_BLUETOOTH_PRIMARY_CONTROLLER
+                        ):
+                            continue
+
                         events_in = None
                         acl_in    = None
                         acl_out   = None
@@ -341,18 +352,25 @@ async def open_usb_transport(spec):
 
                         # Return if we found all 3 endpoints
                         if acl_in is not None and acl_out is not None and events_in is not None:
-                            return (configuration_index + 1, setting.getNumber(), acl_in, acl_out, events_in)
+                            return (
+                                configuration_index + 1,
+                                setting.getNumber(),
+                                setting.getAlternateSetting(),
+                                acl_in,
+                                acl_out,
+                                events_in
+                            )
                         else:
                             logger.debug(f'skipping configuration {configuration_index + 1} / interface {setting.getNumber()}')
 
         endpoints = find_endpoints(found)
         if endpoints is None:
-            logger.warning('no compatible interface found')
             raise ValueError('no compatible interface found for device')
-        (configuration, interface, acl_in, acl_out, events_in) = endpoints
+        (configuration, interface, setting, acl_in, acl_out, events_in) = endpoints
         logger.debug(
             f'selected endpoints: configuration={configuration}, '
             f'interface={interface}, '
+            f'setting={setting}, '
             f'acl_in=0x{acl_in:02X}, '
             f'acl_out=0x{acl_out:02X}, '
             f'events_in=0x{events_in:02X}, '
@@ -385,7 +403,7 @@ async def open_usb_transport(spec):
 
         source = UsbPacketSource(context, device, acl_in, events_in)
         sink   = UsbPacketSink(device, acl_out)
-        return UsbTransport(context, device, interface, source, sink)
+        return UsbTransport(context, device, interface, setting, source, sink)
     except usb1.USBError as error:
         logger.warning(color(f'!!! failed to open USB device: {error}', 'red'))
         context.close()