Merge pull request #3 from jareware/master

Update USB libs from wixel-SDK.

Author: jamorham

libraries/src/usb/usb.c

@@ -8,7 +8,7 @@
 
 extern uint8 CODE usbConfigurationDescriptor[];
 
-void usbStandardDeviceRequestHandler();
+static void usbStandardDeviceRequestHandler();
 
 #define CONTROL_TRANSFER_STATE_NONE  0
 #define CONTROL_TRANSFER_STATE_WRITE 1
@@ -223,6 +223,12 @@ void usbPoll()
 
                 USBINDEX = 0;  // Select EP0 again because the functions above might have changed USBINDEX.
 
+                // Modify the count so that we don't send more data than the host requested.
+                if(controlTransferBytesLeft > usbSetupPacket.wLength)
+                {
+                    controlTransferBytesLeft = usbSetupPacket.wLength;
+                }
+
                 // Prepare for the first transaction after the SETUP packet.
                 if (controlTransferState == CONTROL_TRANSFER_STATE_NONE)
                 {
@@ -336,7 +342,11 @@ static void usbStandardDeviceRequestHandler()
                 {
                     if ((usbSetupPacket.wValue & 0xFF) >= usbStringDescriptorCount)
                     {
-                        // Invalid string index.
+                        // This is either an invalid string index or it is 0xEE,
+                        // which is defined by Microsoft OS Descriptors 1.0.
+                        // This library provides no features for handling such requests,
+                        // but we call the user's callback in case they want to.
+                        usbCallbackClassDescriptorHandler();
                         return;
                     }
 
@@ -358,14 +368,6 @@ static void usbStandardDeviceRequestHandler()
                 }
             }
 
-            // Modify the count so that we don't send more data than the host requested.
-            // We MUST use the local variable wLength instead of usbSetupPacket.wLength because
-            // USB_SETUP_PACKET may have been over-written by the serial number handler.
-            if(controlTransferBytesLeft > usbSetupPacket.wLength)
-            {
-                controlTransferBytesLeft = usbSetupPacket.wLength;
-            }
-
             controlTransferState = CONTROL_TRANSFER_STATE_READ;
             return;
         }