Allow boards to change the "CircuitPython" text in their USB interface description.

In cases where more than one board is connected to a single computer it can become pretty hard to figure out which board you're actually talking to. For example, if you have several MIDI-compatible boards they all show up as "CircuitPython MIDI". This change allows boards to replace the "CircuitPython" part of their USB descriptors with more specific text, for example, "CircuitPython Feather" or just "Feather". This will let folks more easily tell boards apart.

The new option is named `USB_INTERFACE_NAME` and is available in `mkconfigboard.mk`. For example:

```
USB_INTERFACE_NAME = "Feather"
```

supervisor/supervisor.mk

@@ -91,6 +91,10 @@ else
 	CFLAGS += -DUSB_AVAILABLE
 endif
 
+ifndef USB_INTERFACE_NAME
+USB_INTERFACE_NAME = "CircuitPython"
+endif
+
 ifndef USB_DEVICES
 USB_DEVICES = "CDC,MSC,AUDIO,HID"
 endif
@@ -145,6 +149,7 @@ USB_DESCRIPTOR_ARGS = \
 	--vid $(USB_VID)\
 	--pid $(USB_PID)\
 	--serial_number_length $(USB_SERIAL_NUMBER_LENGTH)\
+	--interface_name $(USB_INTERFACE_NAME)\
 	--devices $(USB_DEVICES)\
 	--hid_devices $(USB_HID_DEVICES)\
   --msc_max_packet_size $(USB_MSC_MAX_PACKET_SIZE)\

tools/gen_usb_descriptor.py

@@ -8,6 +8,7 @@ sys.path.append("../../tools/usb_descriptor")
 from adafruit_usb_descriptor import audio, audio10, cdc, hid, midi, msc, standard, util
 import hid_report_descriptors
 
+DEFAULT_INTERFACE_NAME = 'CircuitPython'
 ALL_DEVICES='CDC,MSC,AUDIO,HID'
 ALL_DEVICES_SET=frozenset(ALL_DEVICES.split(','))
 DEFAULT_DEVICES='CDC,MSC,AUDIO,HID'
@@ -32,6 +33,9 @@ parser.add_argument('--devices', type=lambda l: tuple(l.split(',')), default=DEF
                     help='devices to include in descriptor (AUDIO includes MIDI support)')
 parser.add_argument('--hid_devices', type=lambda l: tuple(l.split(',')), default=DEFAULT_HID_DEVICES,
                     help='HID devices to include in HID report descriptor')
+parser.add_argument('--interface_name', type=str,
+                    help='The name/prefix to use in the interface descriptions',
+                    default=DEFAULT_INTERFACE_NAME)
 parser.add_argument('--msc_max_packet_size', type=int, default=64,
                     help='Max packet size for MSC')
 parser.add_argument('--no-renumber_endpoints', dest='renumber_endpoints', action='store_false',
@@ -151,7 +155,7 @@ cdc_comm_interface = standard.InterfaceDescriptor(
     bInterfaceClass=cdc.CDC_CLASS_COMM,  # Communications Device Class
     bInterfaceSubClass=cdc.CDC_SUBCLASS_ACM,  # Abstract control model
     bInterfaceProtocol=cdc.CDC_PROTOCOL_NONE,
-    iInterface=StringIndex.index("CircuitPython CDC control"),
+    iInterface=StringIndex.index("{} CDC control".format(args.interface_name)),
     subdescriptors=[
         cdc.Header(
             description="CDC comm",
@@ -172,7 +176,7 @@ cdc_comm_interface = standard.InterfaceDescriptor(
 cdc_data_interface = standard.InterfaceDescriptor(
     description="CDC data",
     bInterfaceClass=cdc.CDC_CLASS_DATA,
-    iInterface=StringIndex.index("CircuitPython CDC data"),
+    iInterface=StringIndex.index("{} CDC data".format(args.interface_name)),
     subdescriptors=[
         standard.EndpointDescriptor(
             description="CDC data out",
@@ -192,7 +196,7 @@ msc_interfaces = [
         bInterfaceClass=msc.MSC_CLASS,
         bInterfaceSubClass=msc.MSC_SUBCLASS_TRANSPARENT,
         bInterfaceProtocol=msc.MSC_PROTOCOL_BULK,
-        iInterface=StringIndex.index("CircuitPython Mass Storage"),
+        iInterface=StringIndex.index("{} Mass Storage".format(args.interface_name)),
         subdescriptors=[
             standard.EndpointDescriptor(
                 description="MSC in",
@@ -256,7 +260,7 @@ hid_interfaces = [
         bInterfaceClass=hid.HID_CLASS,
         bInterfaceSubClass=hid.HID_SUBCLASS_NOBOOT,
         bInterfaceProtocol=hid.HID_PROTOCOL_NONE,
-        iInterface=StringIndex.index("CircuitPython HID"),
+        iInterface=StringIndex.index("{} HID".format(args.interface_name)),
         subdescriptors=[
             hid.HIDDescriptor(
                 description="HID",
@@ -272,9 +276,9 @@ hid_interfaces = [
 
 # USB OUT -> midi_in_jack_emb -> midi_out_jack_ext -> CircuitPython
 midi_in_jack_emb = midi.InJackDescriptor(
-    description="MIDI PC -> CircuitPython",
+    description="MIDI PC -> {}".format(args.interface_name),
     bJackType=midi.JACK_TYPE_EMBEDDED,
-    iJack=StringIndex.index("CircuitPython usb_midi.ports[0]"))
+    iJack=StringIndex.index("{} usb_midi.ports[0]".format(args.interface_name)))
 midi_out_jack_ext = midi.OutJackDescriptor(
                     description="MIDI data out to user code.",
                     bJackType=midi.JACK_TYPE_EXTERNAL,
@@ -287,10 +291,10 @@ midi_in_jack_ext = midi.InJackDescriptor(
                     bJackType=midi.JACK_TYPE_EXTERNAL,
                     iJack=0)
 midi_out_jack_emb = midi.OutJackDescriptor(
-    description="MIDI PC <- CircuitPython",
+    description="MIDI PC <- {}".format(args.interface_name),
     bJackType=midi.JACK_TYPE_EMBEDDED,
     input_pins=[(midi_in_jack_ext, 1)],
-    iJack=StringIndex.index("CircuitPython usb_midi.ports[1]"))
+    iJack=StringIndex.index("{} usb_midi.ports[1]".format(args.interface_name)))
 
 
 audio_midi_interface = standard.InterfaceDescriptor(
@@ -298,7 +302,7 @@ audio_midi_interface = standard.InterfaceDescriptor(
     bInterfaceClass=audio.AUDIO_CLASS_DEVICE,
     bInterfaceSubClass=audio.AUDIO_SUBCLASS_MIDI_STREAMING,
     bInterfaceProtocol=audio.AUDIO_PROTOCOL_V1,
-    iInterface=StringIndex.index("CircuitPython MIDI"),
+    iInterface=StringIndex.index("{} MIDI".format(args.interface_name)),
     subdescriptors=[
         midi.Header(
             jacks_and_elements=[
@@ -309,12 +313,12 @@ audio_midi_interface = standard.InterfaceDescriptor(
             ],
         ),
         standard.EndpointDescriptor(
-            description="MIDI data out to CircuitPython",
+            description="MIDI data out to {}".format(args.interface_name),
             bEndpointAddress=args.midi_ep_num_out | standard.EndpointDescriptor.DIRECTION_OUT,
             bmAttributes=standard.EndpointDescriptor.TYPE_BULK),
         midi.DataEndpointDescriptor(baAssocJack=[midi_in_jack_emb]),
         standard.EndpointDescriptor(
-            description="MIDI data in from CircuitPython",
+            description="MIDI data in from {}".format(args.interface_name),
             bEndpointAddress=args.midi_ep_num_in | standard.EndpointDescriptor.DIRECTION_IN,
             bmAttributes=standard.EndpointDescriptor.TYPE_BULK,
             bInterval = 0x0),
@@ -334,7 +338,7 @@ audio_control_interface = standard.InterfaceDescriptor(
         bInterfaceClass=audio.AUDIO_CLASS_DEVICE,
         bInterfaceSubClass=audio.AUDIO_SUBCLASS_CONTROL,
         bInterfaceProtocol=audio.AUDIO_PROTOCOL_V1,
-        iInterface=StringIndex.index("CircuitPython Audio"),
+        iInterface=StringIndex.index("{} Audio".format(args.interface_name)),
         subdescriptors=[
             cs_ac_interface,
         ])