Re: [PATCH v5 01/16] dt-bindings: regulator: Document ROHM BD71282 regulator bindings

From: Vaittinen, Matti
Date: Tue Dec 10 2019 - 08:07:41 EST



On Tue, 2019-12-10 at 12:45 +0000, Mark Brown wrote:
> On Tue, Dec 10, 2019 at 12:41:47PM +0000, Vaittinen, Matti wrote:
>
> > The thing is that if we do initial setting of voltages (based on
> > binding data) we can set the voltages to registers before we switch
> > to
> > that run-level. If we don't do initial setting then we will only do
> > setting when voltage change is actually requested - which may be
> > too
> > late. (I actually heard somewhere that there is 40 uS time limit -
> > but
> > I don't see how this is counted. Starting from what? - and I don't
> > see
> > how this is guaranteed even with GPIO if interrupts are to be
> > served).
>
> I suspect that if that limit is a real thing it's from some runtime
> performance metrics where people are doing benchmarking to verify
> that
> everything is working fine rather than an absolute thing that is a
> basic
> requirement for operation.
>
> > So, I am again wondering if I should just upstream the basic
> > control
> > with I2C for SoCs which do not require fast DVS voltage changes and
> > perhaps maintain/provide own set of patches with additional
> > interface
> > for run-level control for those customers who require it... Sorry
> > for
> > being such a difficult guy. Decision making seems to not be my
> > strong
> > point :/
>
> Yes, definitely submit the basic stuff separately - the GPIO changes
> can
> be reviewed as a separate, incremental patch.

Right. That was rationale behind splitting the regulator support in two
patches. I was just unsure if I should add all the DT bindings already
here. Well, I guess I will drop the run-level ones for now. Adding new
bindings later might not be as hard as removing them. Thanks for
support! Discussing this with someone is definitely helpful :)

Br,
Matti