Minor corrections for the XMEGA USB controller. Add compile time warning if...

Minor corrections for the XMEGA USB controller. Add compile time warning if the USB clock frequency is provably incorrect.

LUFA/Drivers/USB/Core/XMEGA/Endpoint_XMEGA.h

@@ -290,6 +290,10 @@
 			                                              const uint8_t Banks)
 			{
 				uint8_t EPConfigMask = (USB_EP_INTDSBL_bm | Banks | Endpoint_BytesToEPSizeMask(Size));
+				
+				// TODO - Fix once limitations are lifted
+				if ((Banks != ENDPOINT_BANK_SINGLE) || (Size > 64))
+				  return false;
 
 				switch (Type)
 				{
@@ -473,7 +477,7 @@
 				if (USB_Endpoint_SelectedHandle->STATUS & USB_EP_SETUP_bm)
 				{
 					USB_Endpoint_SelectedFIFO->Length = USB_Endpoint_SelectedHandle->CNT;
-					return true;				
+					return true;
 				}
 			
 				return false;
@@ -489,8 +493,8 @@
 			static inline void Endpoint_ClearSETUP(void) ATTR_ALWAYS_INLINE;
 			static inline void Endpoint_ClearSETUP(void)
 			{
+				Endpoint_SelectEndpoint(USB_Endpoint_SelectedEndpoint & ~ENDPOINT_DIR_IN);
 				USB_Endpoint_SelectedHandle->STATUS &= ~(USB_EP_SETUP_bm | USB_EP_TRNCOMPL0_bm | USB_EP_BUSNACK0_bm | USB_EP_OVF_bm);
-
 				USB_Endpoint_SelectedHandle->STATUS |= USB_EP_TOGGLE_bm;
 				USB_Endpoint_SelectedFIFO->Position  = 0;
 
@@ -543,7 +547,7 @@
 				if ((USB_Endpoint_SelectedHandle->CTRL & USB_EP_TYPE_gm) == USB_EP_TYPE_CONTROL_gc)
 				{
 					Endpoint_SelectEndpoint(USB_Endpoint_SelectedEndpoint |  ENDPOINT_DIR_IN);
-					USB_Endpoint_SelectedHandle->STATUS |= USB_EP_STALL_bm;
+					USB_Endpoint_SelectedHandle->CTRL |= USB_EP_STALL_bm;
 					Endpoint_SelectEndpoint(USB_Endpoint_SelectedEndpoint & ~ENDPOINT_DIR_IN);
 				}
 			}
@@ -567,7 +571,7 @@
 			static inline bool Endpoint_IsStalled(void) ATTR_WARN_UNUSED_RESULT ATTR_ALWAYS_INLINE;
 			static inline bool Endpoint_IsStalled(void)
 			{
-				return ((USB_Endpoint_SelectedHandle->STATUS & USB_EP_STALLF_bm) ? true : false);
+				return ((USB_Endpoint_SelectedHandle->CTRL & USB_EP_STALL_bm) ? true : false);
 			}
 
 			/** Resets the data toggle of the currently selected endpoint. */

LUFA/Drivers/USB/Core/XMEGA/USBController_XMEGA.h

@@ -94,6 +94,10 @@
 		#if !defined(F_USB)
 			#error F_USB is not defined. You must define F_USB to the frequency of the unprescaled USB controller clock in your project makefile.
 		#endif
+		
+		#if (F_USB % 6000000)
+			#error Invalid F_USB specified. F_USB must be a multiple of 6MHz for USB Low Speed operation, and a multiple of 48MHz for Full Speed operation.
+		#endif
 
 	/* Public Interface - May be used in end-application: */
 		/* Macros: */