On Mon, Aug 24, 2020 at 01:09:22PM +0300, Dmitry Osipenko wrote: > 24.08.2020 00:16, Lubomir Rintel пишет: > > Hello, > > > > On Sun, Aug 23, 2020 at 10:31:36PM +0300, Dmitry Osipenko wrote: > >> 23.08.2020 21:20, Lubomir Rintel пишет: > >>> On Sun, Aug 23, 2020 at 05:08:44PM +0300, Dmitry Osipenko wrote: > >>>> The ENE KB930 hardware is compatible with KB3930. > >>>> > >>>> Acer A500 Iconia Tab is Android tablet device, it has KB930 controller > >>>> that is running firmware specifically customized for the needs of the > >>>> Acer A500 hardware. This means that firmware interface isn't re-usable > >>>> by other non-Acer devices. Some akin models of Acer tablets should be > >>>> able to re-use the FW interface of A500 model, like A200 for example. > >>>> > >>>> This patch adds the new compatibles to the binding. > >>> > >>> I've responded to patch 5/6 with what should've been said here [1]. > >>> Sorry for the confusion. > >>> > >>> In any case please consider adding a new binding file instead of > >>> modifying the kb3930 binding doc. It would also remove a dependency on > >>> my patch set which should have slipped out of maintainers' radar. > >>> > >>> [1] https://lore.kernel.org/lkml/20200823180041.GB209852@demiurge.local/ > >> > >> Hello, Lubomir! I was doing some research about the differences of > >> KB3930 and KB930 before created this patch and my understanding is that > >> the controllers are mostly identical. I've seen posts from people who > >> replaced KB3930 with KB930 (and vice versa) on various notebooks and it > >> worked, although not always. > >> > >> It's a very common practice to re-use binding in a case of a sibling > >> hardware. Do you know what are the exact differences between KB3930 and > >> KB930 which could justify having separate bindings? > >> > >> The firmware implementation varies a lot from device to device, > > > > It sometimes does. The ENE's downstream driver suggests there are parts > > that run more-or-less stock firmware that are comatible with each other. > > That is why I grabbed the generic kb3930 name. > > > >> and > >> thus, each device needs to have its own driver in order to talk to the > >> firmware, but hardware description (i.e. DT binding) should be common > >> for all devices. > > > > Note the DT is not the hardware description. It's the description of how > > the hardware presents itself, from the software's perspective. As far as > > that is concerned, the devices don't seem to have anything in common at > > all (other than the bus address). The fact that you need an entirely > > different driver implies this. > > > > This would be the case even if the A500 EC was based directly on a KB3930. > > > > A good reason to keep bindings for different yet somewhat similar devices in > > a single document is to avoid duplication. Yet here there's very little to > > share here. If you've done your bindings correctly, you'd need to > > conditionalize the monitored-battery and power-supplies properties for > > acer,a500-iconia-ec, complicating the binding too much. It makes more > > sense to just add a new document. > > Alright, I don't mind to separate the bindings. Although, before doing > that, I'd want to get opinion from the device-tree experts, i.e. from > Rob Herring :) > > Rob, will it be fine to have separate bindings for each firmware version > of the ENE controller given that firmware is individual for every device > and given that FW has no compatibility with other devices? Seems like separate bindings makes sense here. Rob
