OMAPL138/AM1808 at 456Mhz

Hi 

      I'm working with OMAP L138 LCDK kit and i'm using linux. 

      How to check the ARM core running speed whether its 350Mhz or 456Mhz ?

      And how to configure the ARMcore for 456Mhz. 

      cat/proc/cpuinfo saying that  BogoMIPS : 148.88

Thanks

Sangly kumar.