On Wed, Sep 06, 2023 at 12:01:43PM +0100, Kieran Bingham wrote: > 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. You would still need to name the node that groups the regulators and clocks in a way that wouldn't clash between multiple overlays and the base board. It would be nice to have nodes that are "private" to an overlay. > And the items are still not on a 'bus' with an address - they just exist > on a presumably externally provided board.... -- Regards, Laurent Pinchart
