Re: [PATCH v24 04/12] mfd: psci-mfd: Add PSCI MFD driver for cpuidle-psci-domain cell

[Bartosz Golaszewski]

On Fri, 21 Aug 2026 14:59:49 +0200, Ulf Hansson
<ulf.hansson@xxxxxxxxxxxxxxxx> said:
> On Mon, Aug 3, 2026 at 11:45 AM Shivendra Pratap
> <shivendra.pratap@xxxxxxxxxxxxxxxx> wrote:
>>
>> PSCI has multiple kernel consumers, such as cpuidle-psci-domain.
>> Currently, both the PSCI core driver and cpuidle-psci-domain bind
>> directly to the same PSCI node "arm,psci-1.0". Additional consumers, if
>> introduced, would also need to bind in the same way, leading to several
>> drivers attached to a single device node.
>>
>> Introduce a PSCI MFD driver that binds to "arm,psci-1.0" and registers
>> PSCI child cells. As the first user, register cpuidle-psci-domain as a
>> child cell.
>
> I don't think PSCI should be modeled as an MFD device with childrens.
>
> Instead, this looks rather like a better fit for the auxiliary
> bus/driver. Please consider using that instead.
>

Hi Uffe!

Since I was the one to suggest MFD - would you mind providing more arguments
in favor of your preferred option?

My reasoning for MFD was that it is indeed a device that provides multiple
functionalities, of which cpuidle is not really he main one even though it's
currently the only driver binding to this node.

In any case, we'd need a "core" driver binding to the psci node and with
multiple auxiliary devices with their own drivers, we'd end up reimplementing
MFD.

Thanks,
Bartosz