Forgot Oneplus One pin. How to enable usb debugging?
You can boot into recovery, then adb should be enabled by default. But I don't know what you want to do to reset your code. If you would have rooted the phone, then you may be able to do that but I think you can't reset the code from adb. The only thing you may do is, first make an adb backup, then do a factory reset and get the data back from your backup.