Play and Record audio Iphone, AudioUnit

Question

I want to add to this http://www.cocoawithlove.com/2010/10/ios-tone-generator-introduction-to.html example the recordCallBack:

i add:

recordingCallback:

static OSStatus recordingCallback(void *inRefCon, 
                              AudioUnitRenderActionFlags *ioActionFlags, 
                              const AudioTimeStamp *inTimeStamp, 
                              UInt32 inBusNumber, 
                              UInt32 inNumberFrames, 
                              AudioBufferList *ioData) {

NSlog(@"recordingCallback");
...

return noErr;
}

and add to the output audio unit (toneUnit) config.

// Set input callback
input.inputProc = recordingCallback;
input.inputProcRefCon = self;
err = AudioUnitSetProperty(toneUnit,
                              kAudioOutputUnitProperty_SetInputCallback,
                              kAudioUnitScope_Global,
                              1,
                              &input,
                              sizeof(input));

...

err = AudioUnitSetProperty (toneUnit,
                            kAudioUnitProperty_StreamFormat,
                            kAudioUnitScope_Output,
                            1,
                            &streamFormat,
                            sizeof(AudioStreamBasicDescription));

iphone asked for permission to use microphone, but my recording callback is never called

update SOLUTION

AudioUnitAddRenderNotify(
iOUnit,
&recordingCallback,
self
);