Alphan,
May I ask which Timer event you are trying to generate to ARM core please? Are you configuring the Timer in general purpose mode please?
Please note Timer 0~7 are dedicated to DSP CorePacs when they are using as Watchdog Timer.
And are you enabling IRQ in ARM core please (may involve ARM control register programming), besides configuring GIC?
It will be great if you could share your code of how to configure the Timer event/ARM GIC/ARM IRQ that we could confirm if the event mapping and interrupt triggering is correct or not. Thanks.