On Tue, Apr 09, 2019 at 01:31:57PM +0200, Ondřej Jirman wrote: > Hi Jagan, > > On Tue, Apr 09, 2019 at 02:08:18PM +0530, Jagan Teki wrote: > > Based on the conversation about using common dtsi from this thread[1], > > I'm commenting here to make show the diff directly on the nodes, > > giving comments on each node so-that we can see the diff globally. > > Thanks for the suggestions below. It mostly repeats the differences and > commonalities I already stated in the previous discussion. > > I don't have much to add to what I already said previously, though, because you > didn't address my concerns there. But I can restate and expand on those > concerns. > > Previously I already agreed it's possible to base orangepi-3.dts on > orangepi.dtsi, and proposed a maintainable way forward, and why to follow it (to > quote myself): > > Schematics allow for high amount of variability in the power tree (see all the > NC (not connected) / 0R resistors) in the schematic around AXP805. Every board > based on this Xunlong design can be subtly different. > > I already suggested a maintainable solution, below. Where base dtsi has empty > config for regulators and every board based on that just defines it completely > for itself. > > A few regulators (for CPU/GPU) will most probably have the same meaning on > every derived board, so these can probably be kept in dtsi without causing too > much annoyance. > > It's unpleasant to have wrong regulator setup defined in an underlying dtsi, > and then trying to override it by removing/adding random properties in the > board dts for the new boards based on that, so that it fits. > > The rest of the current HW descriptions in the sun50i-h6-orangepi.dtsi can be > shared (as of now). > > My suggestion was this: > > So to base Orange Pi 3 dts on top of existing sun50i-h6-orangepi.dtsi I'd have > to first move some things out of the base dtsi to the OrangePi Lite2 and One > Plus board dts files, in order to have sun50i-h6-orangepi.dtsi only describe > HW that is *really* shared by these 2 boards and Orange Pi 3. > > If I do that, I'd undefine all the axp805 regulator nodes and move the > configurations to each of the 3 board files. That will probably end up being > the least confusing and most maintainable. See axp81x.dtsi lines 86-144 for > what I mean. > > You seem to be suggesting a solution where every time we add an OrangePi H6 > based board, the person adding it will have to go through the base dtsi and all > the other boards based on it, status disable or otherwise change regulators in > the base dtsi, patch all the other boards to re-enable it. > > It would be already unpleasant just adding a third board based on this approach. > And when the fourth board is added, with another small differences in the > regulator use/meanings, the person will be looking at patching 4 dts files > + adding one for his own board. For what benefit, to save some bytes right now? > > I think maintainability, ease of adding new boards is more important, than > having a dtsi that tries to maximally cover all the commonalities between the > existing boards right now, without regards for the future. That's why > I suggested an approach like in axp81x.dtsi lines 86-144. I agree. Maxime -- Maxime Ripard, Bootlin Embedded Linux and Kernel engineering https://bootlin.com
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