Messages in this thread | | | Subject | Re: [PATCH 3/3] arm64: dts: mediatek: mt8365-pumpkin: Add overlays for thp7312 cameras | From | Kieran Bingham <> | Date | Wed, 06 Sep 2023 12:01:43 +0100 |
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Quoting Laurent Pinchart (2023-09-06 10:35:31) > On Wed, Sep 06, 2023 at 11:21:31AM +0200, Krzysztof Kozlowski wrote: > > On 06/09/2023 11:00, Laurent Pinchart wrote: > > >>> has a regulator@0. There are similar instances for clocks. > > >>> > > >>> I understand why it may not be a good idea, and how the root node is > > >>> indeed not a bus. In some cases, those regulators and clocks are grouped > > >>> in a regulators or clocks node that has a "simple-bus" compatible. I'm > > >>> not sure if that's a good idea, but at least it should validate. > > >>> > > >>> What's the best practice for discrete board-level clocks and regulators > > >>> in overlays ? How do we ensure that their node name will not conflict > > >>> with the board to which the overlay is attached ? > > >> > > >> Top-level nodes (so under /) do not have unit addresses. If they have - > > >> it's an error, because it is not a bus. Also, unit address requires reg. > > >> No reg? No unit address. DTC reports this as warnings as well. > > > > > > I agree with all that, but what's the recommended practice to add > > > top-level clocks and regulators in overlays, in a way that avoids > > > namespace clashes with the base board ? > > > > Whether you use regulator@0 or regulator-0, you have the same chances of > > clash. > > No disagreement there. My question is whether there's a recommended > practice to avoid clashes, or if it's an unsolved problem that gets > ignored for now because there's only 36h in a day and there are more > urgent things to do.
Should an overlay add these items to a simple-bus specific to that overlay/device that is being supported?
That would 'namespace' the added fixed-clocks/fixed-regulators etc...
But maybe it's overengineering or mis-using the simple-bus.
And the items are still not on a 'bus' with an address - they just exist on a presumably externally provided board....
-- Kieran
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