I hope the nice people on the list can help me again this time. I have to use the i2c bus 3 to control a sound amplifier (tpa6130a2). I have an evaluation board that I will connect to the pins 23 and 24 of a Tobi board. I want to make a program that changes the volume, for example.
I've read this https://github.com/scottellis/overo-mcp23017 and I tried to do the same with this driver for the tpa6130a2 http://lxr.free-electrons.com/source/sound/soc/codecs/tpa6130a2.c?a=arm but I think that I'm mixing concepts here. Is that driver of any use for me? how can I register my amplifier as slave and use the function in there from the Overo userland?

Thanks a lot for your time, all this is very interesting but completely new to me.