Re: [PATCH v1 4/6] dt-bindings: mfd: ene-kb3930: Add compatibles for KB930 and Acer A500

Dmitry Osipenko
2020-08-23T19:31:45Z

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, 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.