CEC didn't work for me possibly because I go through a HDMI hub etc.
So I bought one of these
The IR was pretty weak but I just learnt the commands with a Harmony remote and all is well. It does the basic things you want a Kodi setup to do which cursor up/down/left/right, Enter, back etc. The mouse even works on the original remote but that is not used much in Kodi (or Plex). Happy with this.

