To reply to my own question.
I'm now using
port_pin_config_t config = {
kPORT_PullUp,
kPORT_FastSlewRate,
kPORT_PassiveFilterDisable,
kPORT_OpenDrainDisable,
kPORT_LowDriveStrength,
kPORT_MuxAsGpio,
kPORT_UnlockRegister,
};
// column lines
PORT_SetPinConfig(Port_Key_Col0, Pin_Key_Col0, &config);
PORT_SetPinConfig(Port_Key_Col1, Pin_Key_Col1, &config);
PORT_SetPinConfig(Port_Key_Col2, Pin_Key_Col2, &config);
PORT_SetPinConfig(Port_Key_Col3, Pin_Key_Col3, &config);
I think its working OK.
Thanks