[PATCH v3 1/4] i2c: mux-pinctrl: Rework to honor disabled child nodes

[Wolfram Sang]

> If modifying i2c-mux-pinctrl to respect the sub-bus status property is
> such a big issue, I'd rather leave the driver as is and expose all
> sub-busses to userspace.

Well, dunno what 'big issue' is in your book :) What definately needs to
be done is:

* handle "status" at mux-core level, not mux-driver
* that probably needs us to convert i2c_add_mux_adapter() to return
  ERR_PTRs instead of NULL, so we can distinguish the "disabled" case
* that would mean to fix all existing users

That's all not groundbreaking stuff, but needs caution and thoroughness.
There might be some gory details left, though...

Regards,

   Wolfram