according to the Datasheet (https://wiki.innovaphone.com/index.php?title=Datasheet_IP222) the IP222A supports only 13r2 or higher. I don't think innovaphone will ever release a v12 firmware. The same happened for other devices like the IP101 phone or the IP1203 Dect base station.
But this is not generally an issue, as you can use endpoints running v13 firmware on v12 PBX.