Cortex-A35 Counter-timer Physical Count register (CNTPCT_EL0) always reads zero

Counter-timer Physical Count register CNTPCT_EL0 always reads zero on FVP_Base_Cortex-A35x1. 

I expect the value of this register to change over time. 

I set $CNTFRQ_EL0=35000000, and $CNTP_CTL_EL0=5.

What is the possible reasons, and how is there any configuration I need make to enable this counter? Thanks