Minor device driver API simplifications

USBHost.h

 	//   device has its vid&pid, class/subclass fields initialized
 	//   type is 0 for device level, 1 for interface level, 2 for IAD
 	//   descriptors points to the specific descriptor data
-	virtual bool claim(Device_t *device, int type, const uint8_t *descriptors) {
-		return false;
-	}
+	virtual bool claim(Device_t *device, int type, const uint8_t *descriptors);
+
 	// When an unknown (not chapter 9) control transfer completes, this
 	// function is called for all drivers bound to the device.  Return
 	// true means this driver originated this control transfer, so no
 	// more drivers need to be offered an opportunity to process it.
-	virtual bool control(const Transfer_t *transfer) {
-		return false;
-	}
+	// This function is optional, only needed if the driver uses control
+	// transfers and wishes to be notified when they complete.
+	virtual void control(const Transfer_t *transfer) { }
+
 	// When a device disconnects from the USB, this function is called.
 	// The driver must free all resources it has allocated.
-	virtual void disconnect() {
-	}
+	virtual void disconnect();
+
 	// Drivers are managed by this single-linked list.  All inactive
 	// (not bound to any device) drivers are linked from
 	// available_drivers in enumeration.cpp.  When bound to a device,
 	// drivers are linked from that Device_t drivers list.
 	USBDriver *next;
-	// When not bound to any device, this must be NULL.
+
+	// The device this object instance is bound to.  In words, this
+	// is the specific device this driver is using.  When not bound
+	// to any device, this must be NULL.
 	Device_t *device;
+
 	friend class USBHost;
 public:
 	// TODO: user-level functions
 	USBHub();
 protected:
 	virtual bool claim(Device_t *device, int type, const uint8_t *descriptors);
-	virtual bool control(const Transfer_t *transfer);
+	virtual void control(const Transfer_t *transfer);
+	virtual void disconnect();
 	void poweron(uint32_t port);
 	void getstatus(uint32_t port);
 	void clearstatus(uint32_t port);

hub.cpp

 	queue_Control_Transfer(device, &setup, NULL, this);
 }
 
-bool USBHub::control(const Transfer_t *transfer)
+void USBHub::control(const Transfer_t *transfer)
 {
 	Serial.println("USBHub control callback");
 	print_hexbytes(transfer->buffer, transfer->length);
 
 	if (state == 0) {
 		// read hub descriptor to learn hub's capabilities
-		if (transfer->buffer != hub_desc) return false;
 		// Hub Descriptor, USB 2.0, 11.23.2.1 page 417
 		if (hub_desc[0] == 9 && hub_desc[1] == 0x29) {
 			numports = hub_desc[2];
 		  case 0x000000A0: // get hub status
 			Serial.println("New Hub Status");
 			clearstatus(0);
-			return true;
+			return;
 		  case 0x000000A3: // get port status
 			Serial.print("New Port Status, port=");
 			Serial.println(setup.wIndex);
 			clearstatus(setup.wIndex);
-			return true;
+			return;
 		  case 0x00100120: // clear hub status
 			Serial.println("Hub Status Cleared");
 			changebits &= ~1;
 		}
 		update_status();
 	}
-	return true;
 }
 
 void USBHub::callback(const Transfer_t *transfer)
 	}
 }
 
+void USBHub::disconnect()
+{
+	// TODO: free resources
+}
+
+
 /*
 config descriptor from a Multi-TT hub
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