Re: [RFC v4 01/14] regulator: of: Add helper for getting all supplies

[Rafael J. Wysocki]

On Thu, Jun 9, 2016 at 12:29 PM, Mark Brown <broonie@xxxxxxxxxx> wrote:
> On Thu, Jun 09, 2016 at 11:44:18AM +0200, Krzysztof Kozlowski wrote:
>> Few drivers have a need of getting regulator supplies without knowing
>> their names:
>> 1. The Simple Framebuffer driver works on setup provided by bootloader
>>    (outside of scope of kernel);
>> 2. Generic power sequence driver may be attached to any device node.
>>
>> Add a Device Tree helper for parsing "-supply" properties and returning
>> allocated bulk regulator consumers.
>
> I'm still very concerned that this is just an invitation to people to
> write half baked regulator consumers and half baked DTs to go along with
> it, making it a standard API that doesn't have big red flags on it that
> will flag up when "normal" drivers use it is not good.  Right now this
> just looks like a standard API and people are going to just start using
> it.  If we are going to do this perhaps we need a separate header or
> something to help flag this up.
>
> In the case of power sequences I'd expect the sequences to perform
> operations on named supplies - the core shouldn't know what the supplies
> are but the thing specifying the sequence should.
>
>>  drivers/regulator/of_regulator.c       | 86 ++++++++++++++++++++++++++++++++++
>>  include/linux/regulator/of_regulator.h | 13 +++++
>>  2 files changed, 99 insertions(+)
>
> The external interface shouldn't be DT specific, the Intel people are
> busy importing all of DT into ACPI

Well, not really.

If you are referring to the pinctrl proposal discussed recently, that
was a proposal from one group at Intel and AFAICS it has been
abandoned.

> so they'll doubtless want an ACPI version.

That is possible, though, so I agree that the external interface
should not be DT-specific.