The objective of having PUCCH and PUSCH channels is to send uplink control information (UCI) and uplink data to eNodeB.
When an UE already has PUSCH then it uses this channels to send data as well as control information. There is no need to send control information using PUCCH and uplink data through PUSCH.
I am not able to envision of any benefit to transmit on PUCCH and PUSCH simultaneously.
