I've been puzzled a bit by the GPIO modes of the MP pins of the ADAU145x...
Input (0b000) is clear: output register is ignored, input registers shows pin value. Option 0b001 is a bit vaguely described but it just means local loopback (out register -> in register). There's no hint in the documentation what the state is of the physical pin in mode 0b001, but it appears to be undriven.
Output (0b010, 0b011) should have been obvious, however I'm puzzled by being given the option whether I want a pull-up on the output. This makes no sense to me, since such a pull-up would always be overriden by the output value driven onto the pin. My next thought was that perhaps one or both modes are perhaps open-drain, for which a pull-up would make sense, but it seems to be push-pull in both modes?
Is there a difference between the two output modes?