On Mon, Nov 18, 2019 at 01:13:24PM -0500, Sven Van Asbroeck wrote:

> This mfd chip can be wired up as one of the following:
> - gpio only
> - gpio + regulator
> - gpio + led
> - gpio + flash

Is the regulator bit of this perhaps a voltage regulator and a current
regulator packaged together mainly for use powering LEDs?  That's a
hardware design I've seen before...

> in this case, there is no elegant way to specify the regulator properties in
> the devicetree. Except by grabbing a reference to a subnode perhaps. And then
> I'd have to somehow make sure that the sub driver's device->of_node points
> at this subnode, which the mfd core doesn't do automatically.

Just point the regulator framework at the MFD's DT node - the children
of the MFD can look at the parent device happily, there's several
existing MFDs do this.