If wifi chip did not be support by openwrt

Hi All,

We have several models(arm64) with different wifi chip, like realtek, mtk, etc.
We have normal kernel wifi chip source code and we have kernel source code.

If we want all models to switch our codebase to openwrt, but wifi chip support did not show up on menuconfig, what should we do?
Is it possible to modify cfg80211 to support wifi chip and almost bug free?
or create another wifi control flow(sub system) and it can work with existed system on openwrt?
Please advise. Thanks.