First of all you need to know if all your devices support 802.1x authentication. If they support 802.1x then you must decide what "EAP" protocol to use.
Let's suppose Polycom doesn't support 802.1x. Then you could use MAB (Mac address bypass) authentication for Polycom and 802.1x for both PCs and IP Phones. Cisco supports both 802.1x and MAB authentication in the same switchport, but only in certain order, the switchport could try 802.1x first, the Polycom would fail to authenticate so the switchport after a timer would try MAB authentication and then Polycom would authenticate succesfully.
About "EAP" protocols you could use PEAP MSCHAP for PCs and EAP-TLS for IP Phones. That's an option but there are way too many combinations of possible deployments so I advice you to do some labs before actual deployment.
Here's a link with the documentation where you can start
http://www.cisco.com/en/US/prod/collateral/iosswrel/ps6537/ps6586/ps6638/guide_c07-627531.html
Please rate if it helps. Kind regards.
