how to get the mmc interface up and running on cpu level ??

Hi

I am looking for some initialization code for the mmc interface on the BBB.
I already tried for a whole week to get something out of the clk line , but with no succes
I’m sure all clocks needed are on (used the ti cct utility) and the pin muxing should also be ok (used ti pinmux utility)
I don’t have a clue anymore what I could be doing wrong or forget to do.

Everything is welcomed !

Regards ,

Ronny