Hello Enrico & All, First of all - thanks for showing the interest :] I am happy knowing someone actually was interested about the RFC :) On Mon, 2019-11-18 at 10:21 +0100, Enrico Weigelt, metux IT consult wrote: > Hi, > > > > The thing is that > > this approach requires the LED controller binding to dictate > > allowed > > LED node names - which may or may not be doable. I need your help > > to > > evaluate this and suggest better options :) > > even though I like the idea of convention-over-code, but if that's > changing allowed LED names that would risk breaking things, eg: > > a) existing DT's (in the field) become incompatible with newer > kernel versions This was my main concern. This of course would not mean that we could not take this approach for new LED controller drivers - but that would (probably) lead to dual led registration interface - one for current approach where LED drivers do all the dirty work themself - and parse the DT - one for new drivers which could leave DT parsing to LED core. > b) existing userlands that rely on speicific LED names become > incomatible with newer kernel versions. I didn't even think this far, but yes, I see... LED node name might be reflected in user-space LED name. I won't start arguing if this is sane or not - this is what we seem to be living with today :) Anyways, I did send out a LED core change patch which allows one to add either the node-name, or a property-value pair in init_data. LED core can then use either of these to do LED node lookup. If none of these is given, then we can fall-back to existing logic. That way we won't change existing stuff. Here: https://lore.kernel.org/lkml/258b5c9934e2b31a5f433a7dbb908dfe5da3d30c.1574059625.git.matti.vaittinen@xxxxxxxxxxxxxxxxx/T/#u I didn't invest too much of time on this yet - but at first glimpse it seemed that at least some of the drivers did use reg - property with fixed value to do the matching. Those could set the property name to 'reg' and value to 'X' and leave the DT node lookup and common property parsing to the LED core. If my patch won't get too big objection (and if no fatal flaws are found from the idea) - then I might try and find the time to do some follow-up patches simplifying existing LED drivers... > > > > --mtx >
