https://github.com/lwfinger/rtl8723au
I don't write drivers yet, and only now am beginning to tinker with the kernel. The repo has a linux (sic) driver for the dreaded wifi+BT RTL8723AU-VAS (wifi only, BT is the same address + "_bt") card found in the Lenovo Yoga 13 and others. If someone can help me port the driver, that'd be wonderful.