#define DRIVER_DESC            "Printer Gadget"
 #define DRIVER_VERSION         "2007 OCT 06"
+#define GET_DEVICE_ID          0
+#define GET_PORT_STATUS                1
+#define SOFT_RESET             2
 
 static const char shortname [] = "printer";
 static const char driver_desc [] = DRIVER_DESC;
        switch (ctrl->bRequestType&USB_TYPE_MASK) {
        case USB_TYPE_CLASS:
                switch (ctrl->bRequest) {
-               case 0: /* Get the IEEE-1284 PNP String */
+               case GET_DEVICE_ID: /* Get the IEEE-1284 PNP String */
                        /* Only one printer interface is supported. */
                        if ((wIndex>>8) != dev->interface)
                                break;
                                        &dev->pnp_string[2]);
                        break;
 
-               case 1: /* Get Port Status */
+               case GET_PORT_STATUS: /* Get Port Status */
                        /* Only one printer interface is supported. */
                        if (wIndex != dev->interface)
                                break;
                        value = min(wLength, (u16) 1);
                        break;
 
-               case 2: /* Soft Reset */
+               case SOFT_RESET: /* Soft Reset */
                        /* Only one printer interface is supported. */
                        if (wIndex != dev->interface)
                                break;