Add an alternative way to number the USB endpoints

Two options available:
- relative numbering (USB_RELATIVE_EP_NUM = 1) - default
- absolute numbering (USB_RELATIVE_EP_NUM = 0) - new!

3 files changed, 80 insertions, 26 deletions

diff --git a/ports/atmel-samd/mpconfigport.mk b/ports/atmel-samd/mpconfigport.mk
index 51bbdd658..88ddb49e0 100644
--- a/ports/atmel-samd/mpconfigport.mk
+++ b/ports/atmel-samd/mpconfigport.mk
@@ -22,7 +22,7 @@ CIRCUITPY_FREQUENCYIO = 0
 CIRCUITPY_TOUCHIO_USE_NATIVE = 1
 
 # SAMD21 needs separate endpoint pairs for MSC BULK IN and BULK OUT, otherwise it's erratic.
-USB_MSC_NUM_ENDPOINT_PAIRS = 2
+USB_MSC_EP_NUM_OUT = 1
 endif
 
 # Put samd51-only choices here.
diff --git a/supervisor/supervisor.mk b/supervisor/supervisor.mk
index ee47be4b0..072066630 100644
--- a/supervisor/supervisor.mk
+++ b/supervisor/supervisor.mk
@@ -94,9 +94,40 @@ ifndef USB_HID_DEVICES
 USB_HID_DEVICES = "KEYBOARD,MOUSE,CONSUMER,GAMEPAD"
 endif
 
-# SAMD21 needs separate endpoint pairs for MSC BULK IN and BULK OUT, otherwise it's erratic.
-ifndef USB_MSC_NUM_ENDPOINT_PAIRS
-USB_MSC_NUM_ENDPOINT_PAIRS = 1
+ifndef USB_RELATIVE_EP_NUM
+USB_RELATIVE_EP_NUM = 1
+endif
+
+ifndef USB_CDC_EP_NUM_NOTIFICATION
+USB_CDC_EP_NUM_NOTIFICATION = 0
+endif
+
+ifndef USB_CDC_EP_NUM_DATA_OUT
+USB_CDC_EP_NUM_DATA_OUT = 0
+endif
+
+ifndef USB_CDC_EP_NUM_DATA_IN
+USB_CDC_EP_NUM_DATA_IN = 0
+endif
+
+ifndef USB_MSC_EP_NUM_OUT
+USB_MSC_EP_NUM_OUT = 0
+endif
+
+ifndef USB_MSC_EP_NUM_IN
+USB_MSC_EP_NUM_IN = 0
+endif
+
+ifndef USB_HID_EP_NUM_IN
+USB_HID_EP_NUM_IN = 0
+endif
+
+ifndef USB_MIDI_EP_NUM_OUT
+USB_MIDI_EP_NUM_OUT = 0
+endif
+
+ifndef USB_MIDI_EP_NUM_IN
+USB_MIDI_EP_NUM_IN = 0
 endif
 
 SUPERVISOR_O = $(addprefix $(BUILD)/, $(SRC_SUPERVISOR:.c=.o)) $(BUILD)/autogen_display_resources.o
@@ -116,9 +147,17 @@ autogen_usb_descriptor.intermediate: ../../tools/gen_usb_descriptor.py Makefile
 		--vid $(USB_VID)\
 		--pid $(USB_PID)\
 		--serial_number_length $(USB_SERIAL_NUMBER_LENGTH)\
-	        --devices $(USB_DEVICES)\
+		--devices $(USB_DEVICES)\
 		--hid_devices $(USB_HID_DEVICES)\
-		--msc_num_endpoint_pairs $(USB_MSC_NUM_ENDPOINT_PAIRS)\
+		--relative_ep_num $(USB_RELATIVE_EP_NUM)\
+		--cdc_ep_num_notification $(USB_CDC_EP_NUM_NOTIFICATION)\
+		--cdc_ep_num_data_out $(USB_CDC_EP_NUM_DATA_OUT)\
+		--cdc_ep_num_data_in $(USB_CDC_EP_NUM_DATA_IN)\
+		--msc_ep_num_out $(USB_MSC_EP_NUM_OUT)\
+		--msc_ep_num_in $(USB_MSC_EP_NUM_IN)\
+		--hid_ep_num_in $(USB_HID_EP_NUM_IN)\
+		--midi_ep_num_out $(USB_MIDI_EP_NUM_OUT)\
+		--midi_ep_num_in $(USB_MIDI_EP_NUM_IN)\
 		--output_c_file $(BUILD)/autogen_usb_descriptor.c\
 		--output_h_file $(BUILD)/genhdr/autogen_usb_descriptor.h
 
diff --git a/tools/gen_usb_descriptor.py b/tools/gen_usb_descriptor.py
index c4ff74d39..eccfbea67 100644
--- a/tools/gen_usb_descriptor.py
+++ b/tools/gen_usb_descriptor.py
@@ -32,8 +32,24 @@ 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('--msc_num_endpoint_pairs', type=int, default=1,
-                    help='Use 1 or 2 endpoint pairs for MSC (1 bidirectional, or 1 input + 1 output (required by SAMD21))')
+parser.add_argument('--relative_ep_num', type=int, default=1,
+                    help='use relative(1) or absolute(0) endpoint number')
+parser.add_argument('--cdc_ep_num_notification', type=int, default=0,
+                    help='endpoint number of CDC NOTIFICATION')
+parser.add_argument('--cdc_ep_num_data_out', type=int, default=0,
+                    help='endpoint number of CDC DATA OUT')
+parser.add_argument('--cdc_ep_num_data_in', type=int, default=0,
+                    help='endpoint number of CDC DATA IN')
+parser.add_argument('--msc_ep_num_out', type=int, default=0,
+                    help='endpoint number of MSC OUT')
+parser.add_argument('--msc_ep_num_in', type=int, default=0,
+                    help='endpoint number of MSC IN')
+parser.add_argument('--hid_ep_num_in', type=int, default=0,
+                    help='endpoint number of HID IN')
+parser.add_argument('--midi_ep_num_out', type=int, default=0,
+                    help='endpoint number of MIDI OUT')
+parser.add_argument('--midi_ep_num_in', type=int, default=0,
+                    help='endpoint number of MIDI IN')
 parser.add_argument('--output_c_file', type=argparse.FileType('w'), required=True)
 parser.add_argument('--output_h_file', type=argparse.FileType('w'), required=True)
 
@@ -47,10 +63,6 @@ unknown_hid_devices = list(frozenset(args.hid_devices) - ALL_HID_DEVICES_SET)
 if unknown_hid_devices:
     raise ValueError("Unknown HID devices(s)", unknown_hid_devices)
 
-if args.msc_num_endpoint_pairs not in (1, 2):
-    raise ValueError("--msc_num_endpoint_pairs must be 1 or 2")
-
-
 class StringIndex:
     """Assign a monotonically increasing index to each unique string. Start with 0."""
     string_to_index = {}
@@ -120,7 +132,7 @@ cdc_comm_interface = standard.InterfaceDescriptor(
         cdc_union,
         standard.EndpointDescriptor(
             description="CDC comm in",
-            bEndpointAddress=0x0 | standard.EndpointDescriptor.DIRECTION_IN,
+            bEndpointAddress=args.cdc_ep_num_notification | standard.EndpointDescriptor.DIRECTION_IN,
             bmAttributes=standard.EndpointDescriptor.TYPE_INTERRUPT,
             wMaxPacketSize=0x0040,
             bInterval=0x10)
@@ -133,11 +145,11 @@ cdc_data_interface = standard.InterfaceDescriptor(
     subdescriptors=[
         standard.EndpointDescriptor(
             description="CDC data out",
-            bEndpointAddress=0x0 | standard.EndpointDescriptor.DIRECTION_OUT,
+            bEndpointAddress=args.cdc_ep_num_data_out | standard.EndpointDescriptor.DIRECTION_OUT,
             bmAttributes=standard.EndpointDescriptor.TYPE_BULK),
         standard.EndpointDescriptor(
             description="CDC data in",
-            bEndpointAddress=0x0 | standard.EndpointDescriptor.DIRECTION_IN,
+            bEndpointAddress=args.cdc_ep_num_data_in | standard.EndpointDescriptor.DIRECTION_IN,
             bmAttributes=standard.EndpointDescriptor.TYPE_BULK),
     ])
 
@@ -153,14 +165,12 @@ msc_interfaces = [
         subdescriptors=[
             standard.EndpointDescriptor(
                 description="MSC in",
-                bEndpointAddress=0x0 | standard.EndpointDescriptor.DIRECTION_IN,
+                bEndpointAddress=args.msc_ep_num_in | standard.EndpointDescriptor.DIRECTION_IN,
                 bmAttributes=standard.EndpointDescriptor.TYPE_BULK,
                 bInterval=0),
             standard.EndpointDescriptor(
                 description="MSC out",
-                # SAMD21 needs to use a separate pair of endpoints for MSC.
-                bEndpointAddress=((0x1 if args.msc_num_endpoint_pairs == 2 else 0x0) |
-                                  standard.EndpointDescriptor.DIRECTION_OUT),
+                bEndpointAddress=(args.msc_ep_num_out | standard.EndpointDescriptor.DIRECTION_OUT),
                 bmAttributes=standard.EndpointDescriptor.TYPE_BULK,
                 bInterval=0)
         ]
@@ -197,7 +207,7 @@ else:
 # and will fail (possibly silently) if both are not supplied.
 hid_endpoint_in_descriptor = standard.EndpointDescriptor(
     description="HID in",
-    bEndpointAddress=0x0 | standard.EndpointDescriptor.DIRECTION_IN,
+    bEndpointAddress=args.hid_ep_num_in | standard.EndpointDescriptor.DIRECTION_IN,
     bmAttributes=standard.EndpointDescriptor.TYPE_INTERRUPT,
     bInterval=8)
 
@@ -267,12 +277,12 @@ audio_midi_interface = standard.InterfaceDescriptor(
         ),
         standard.EndpointDescriptor(
             description="MIDI data out to CircuitPython",
-            bEndpointAddress=0x0 | standard.EndpointDescriptor.DIRECTION_OUT,
+            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",
-            bEndpointAddress=0x0 | standard.EndpointDescriptor.DIRECTION_IN,
+            bEndpointAddress=args.midi_ep_num_in | standard.EndpointDescriptor.DIRECTION_IN,
             bmAttributes=standard.EndpointDescriptor.TYPE_BULK,
             bInterval = 0x0),
         midi.DataEndpointDescriptor(baAssocJack=[midi_out_jack_emb]),
@@ -313,10 +323,15 @@ if 'HID' in args.devices:
 if 'AUDIO' in args.devices:
     interfaces_to_join.append(audio_interfaces)
 
-# util.join_interfaces() will renumber the endpoints to make them unique across descriptors,
-# and renumber the interfaces in order. But we still need to fix up certain
-# interface cross-references.
-interfaces = util.join_interfaces(*interfaces_to_join)
+if args.relative_ep_num:
+    # util.join_interfaces() will renumber the endpoints to make them unique across descriptors,
+    # and renumber the interfaces in order. But we still need to fix up certain
+    # interface cross-references.
+    interfaces = util.join_interfaces(*interfaces_to_join)
+else:
+    # util.renumbers_interfaces() will renumber the interfaces in order. But we still need to 
+    # fix up certain interface cross-references.
+    interfaces = util.renumbers_interfaces(*interfaces_to_join)
 
 # Now adjust the CDC interface cross-references.