This link from openprinting.org might help:
https://openprinting.org/printer/Bro...other-DCP-7020
As for the scanner function, if what you find there doesn't help, you might try
XSane or
simple-scan, but I don't think they provide drivers; I think they rely on drivers from other parties.
I have found XSane to be quite reliable, but I have no experience making it work with a Brother printer/scanner.