Here is configuration from my lab switch which has a FCoE device connected to Ethernet 1/2. My FCoE VLAN is 100 and FCOE VSAN is 100. Change these as neccessary and here is the outline of config needed.
feature fcoe
vlan 100
fcoe vsan 100
interface Ethernet1/2
switchport mode trunk
spanning-tree port type edge
interface vfc2
bind interface Ethernet1/2
no shutdown
vsan database
vsan 100
vsan 100 interface vfc2
If its a 55xx, you will need FCoE QoS as well.
system qos
service-policy type queuing input fcoe-default-in-policy
service-policy type queuing output fcoe-default-out-policy
service-policy type qos input fcoe-default-in-policy
service-policy type network-qos fcoe-default-nq-policy