Re: [PATCH 2/4] dt-bindings: pinctrl: tegra194: Separate instances

[Thierry Reding <thierry.reding@gmail.com>]

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On Fri, Jul 01, 2022 at 03:19:25PM -0600, Rob Herring wrote:
> On Fri, Jul 01, 2022 at 05:04:59PM +0200, Thierry Reding wrote:
> > From: Thierry Reding <treding@nvidia.com>
> > 
> > Tegra194 has two separate instances of the pin controller, one called
> > AON (in the always-on domain) and another called "main". Instead of
> > treating them as a single pin controller, split them up into two
> > separate controllers. Doing so allows the mapping between the pinmux and
> > GPIO controllers to be trivial identity mappings and more cleanly
> > separates the AON from the main IP blocks.
> 
> Doesn't this break compatibility?

I had added this paragraph to the cover letter:

  Note that while this changes the DT node in an incompatible way, this
  doesn't have any practical implications for backwards-compatibility. The
  reason for this is that device trees have only reconfigured a very
  narrow subset of pins of the main controller, so the new driver will
  remain backwards-compatible with old device trees.

I've now added that to the commit message of this patch in v2 to
hopefully clarify that for posterity.

Thanks,
Thierry

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