Trunk ports with clients from 2 different vlan’s

I have a PC client connected to a IP phone which is in turn connected to a port of a cisco 2960 switch. Both PC and IP phone are to be in different vlan (e.g. 2 and 3 respectively). The port obviously has to be trunk since it serves both vlan 2 and 3. How do I configure so that, during a dhcp request, the switch knows that the PC belongs to vlan 2 and ip phone vlan 3? I know this has been done before but can’t seem to google any useful information on the web.