Set APEX select2 plugin Item Read Only

I have a form with some of the Select2 plugin items, I would like to set it to read only on the Edit page, here is how I do it:

 $('#s2id_P_ITEM').select2("readonly", true);

Replace P_ITEM with your own form Item

New version will be like this:

 $('#P_ITEM').select2("disabled", true);