usbd: Update to handle memoryview request

Previously 'request' was marshalled to and from a tuple
for each control transfer. This makes for ergonomic
Python but a lot of heap allocations, especially as not
every field is read on every request type.

This has a matching code change in micropython to support
it.

Signed-off-by: Angus Gratton <angus@redyak.com.au>

Author: projectgus

micropython/usbd/cdc.py

@@ -295,7 +295,7 @@ def get_endpoint_descriptors(self, ep_addr, str_idx):
 
     def handle_interface_control_xfer(self, stage, request):
         # Handle class-specific interface control transfers
-        bmRequestType, bRequest, wValue, _, wLength = request
+        bmRequestType, bRequest, wValue, _, wLength = struct.unpack("BBHHH", request)
         recipient, req_type, req_dir = split_bmRequestType(bmRequestType)
         if stage == STAGE_SETUP:
             if req_type == REQ_TYPE_CLASS:

micropython/usbd/device.py

@@ -352,8 +352,8 @@ def _control_xfer_cb(self, stage, request):
         # The TinyUSB class driver framework only calls this function for
         # particular types of control transfer, other standard control transfers
         # are handled by TinyUSB itself.
-        bmRequestType, _, _, wIndex, _ = request
-        recipient, _, _ = split_bmRequestType(bmRequestType)
+        wIndex = request[4] + (request[5] << 8)
+        recipient, _, _ = split_bmRequestType(request[0])
 
         itf = None
         result = None
@@ -376,7 +376,7 @@ def _control_xfer_cb(self, stage, request):
             # At time this code was written, only the control transfers shown
             # above are passed to the class driver callback. See
             # invoke_class_control() in tinyusb usbd.c
-            print(f"Unexpected control request type {bmRequestType:#x}")
+            print(f"Unexpected control request type {request[0]:#x}")
             return False
 
         # Accept the following possible replies from handle_NNN_control_xfer():
@@ -532,11 +532,13 @@ def handle_device_control_xfer(self, stage, request):
         # Parameters:
         #
         # - stage is one of utils.STAGE_SETUP, utils.STAGE_DATA, utils.STAGE_ACK.
-        # - request is a tuple of (bmRequestType, bRequest, wValue, wIndex,
-        # - wLength), as per USB 2.0 specification 9.3 USB Device Requests, p250.
         #
-        # The function can call split_bmRequestType() to split bmRequestType into
-        # (Recipient, Type, Direction).
+        # - request is a memoryview into a USB request packet, as per USB 2.0
+        #   specification 9.3 USB Device Requests, p250.  the memoryview is only
+        #   valid while the callback is running.
+        #
+        # The function can call split_bmRequestType(request[0]) to split
+        # bmRequestType into (Recipient, Type, Direction).
         #
         # Result, any of:
         #

micropython/usbd/hid.py

@@ -134,7 +134,7 @@ def get_hid_descriptor(self):
 
     def handle_interface_control_xfer(self, stage, request):
         # Handle standard and class-specific interface control transfers for HID devices.
-        bmRequestType, bRequest, wValue, _, wLength = request
+        bmRequestType, bRequest, wValue, _, wLength = struct.unpack("BBHHH", request)
 
         recipient, req_type, _ = split_bmRequestType(bmRequestType)