Hi Mark, On Tuesday 29 Nov 2016 11:01:25 Mark Brown wrote: > On Tue, Nov 29, 2016 at 11:11:03AM +0200, Laurent Pinchart wrote: > > On Tuesday 29 Nov 2016 13:41:33 Archit Taneja wrote: > >> I thought we couldn't add mandatory properties once the device is > >> already present in DT for one or more platforms. > > > > You can, as long as you treat them as optional in the driver to retain > > backward compatibility. The DT bindings should document the properties > > expected from a new platform (older versions of the bindings will always > > be available in the git history). > > The device probably never worked without power... note that the kernel > will substitute in dummy regulators for anything that isn't explicitly > mapped so it won't actually break anything. > > >> Say, if we do make it mandatory for future additions, we would need to > >> have DT property for the supplies for the new platforms. If the > >> regulators on these boards are fixed supplies, they would be need to be > >> modeled using "regulator-fixed", possibly without any input supply. Is > >> that what you're suggesting? > > > > That's the idea, yes. Clock maintainers have a similar opinion regarding > > the clock bindings, where a clock that is not optional at the hardware > > level should be specified in DT even if it's always present. > > > > Mark, any opinion ? > > It's best practice to always describe the power. The kernel will cope > if people don't but it's not unknown for drivers to discover a reason > for wanting information about their power and hard to retrofit that if > it's not been in there from the get go. Sounds good to me, thanks. > Please note that if you're going to CC me into a graphics thread there's > a good chance I will miss it, I get copied on quite a lot of graphics > related mail that's not really relevant so I often skip it. Changing > the subject line would help with that. I try to add a (CC'ing xxx) at the beginning of the e-mail to draw attention when a question is targetted at a particular person. If that's not enough I can change the subject, but might forget to do so from time to time. Or you could whitelist me, unless I'm already blacklisted ;-) -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
