iOS touch event notifications (private API)

You can use the IOHID stuff in IOKit to get the x, y coordinates.

#include <IOHIDEventSystem.h>

create IOHIDEventSystemClient:

void *ioHIDEventSystem = IOHIDEventSystemClientCreate(kCFAllocatorDefault);

register callback:

IOHIDEventSystemClientScheduleWithRunLoop(ioHIDEventSystem, CFRunLoopGetCurrent(), kCFRunLoopDefaultMode);
IOHIDEventSystemClientRegisterEventCallback(ioHIDEventSystem, handle_event, NULL, NULL);

unregister callback:

IOHIDEventSystemClientUnregisterEventCallback(ioHIDEventSystem, handle_event, NULL, NULL);
IOHIDEventSystemClientUnscheduleWithRunLoop(ioHIDEventSystem, CFRunLoopGetCurrent(), kCFRunLoopDefaultMode);

callback:

void handle_event (void* target, void* refcon, IOHIDServiceRef service, IOHIDEventRef event) {
   if (IOHIDEventGetType(event)==kIOHIDEventTypeDigitizer){
       IOHIDFloat x=IOHIDEventGetFloatValue(event, (IOHIDEventField)kIOHIDEventFieldDigitizerX);
       IOHIDFloat y=IOHIDEventGetFloatValue(event, (IOHIDEventField)kIOHIDEventFieldDigitizerY);
       int width = [[UIScreen mainScreen] bounds].size.width;
       int height = [[UIScreen mainScreen] bounds].size.height;
       NSLog(@"click : %f, %f", x*width, y*height) ;
   }
}

Also, you can check this out:
IOHIDEventSystemCreate on iOS6 failed.
Hope this helps.

EDIT: Please see the result from the log. Tested on iPhone 4 and 5.

void handle_event (void* target, void* refcon, IOHIDServiceRef service, IOHIDEventRef event) {
    NSLog(@"handle_event : %d", IOHIDEventGetType(event));
if (IOHIDEventGetType(event)==kIOHIDEventTypeDigitizer){
    IOHIDFloat x=IOHIDEventGetFloatValue(event, (IOHIDEventField)kIOHIDEventFieldDigitizerX);
    IOHIDFloat y=IOHIDEventGetFloatValue(event, (IOHIDEventField)kIOHIDEventFieldDigitizerY);
    NSLog(@" x %f : y %f", x, y);
//2013-03-28 10:02:52.169 MyIOKit[143:907] handle_event : 11
//2013-03-28 10:02:52.182 MyIOKit[143:907]  x 0.766754 : y 0.555023
}
}