Re: Question about fixed regulator DT properties

From: Vladimir Zapolskiy
Date: Wed Nov 26 2014 - 14:14:16 EST


Hi, MarkOn 26.11.2014 19:53, Mark Brown wrote:
> On Wed, Nov 26, 2014 at 07:27:06PM +0200, Vladimir Zapolskiy wrote:
>> On 25.11.2014 14:17, Mark Brown wrote:
>
>> b) "regulator-boot-on" does not mean that the regulator is controlled by
>> bootloader or firmware exclusively.
>
> That's correct...
>
>>>>> Should documentation be updated to reflect "regulator-boot-on" role that
>>>>> a regulator is re-enabled by the kernel?
>
>>> I'm confused about this. That's the sole purpose of the flag and as far
>>> as I can tell it's what the documentation says.
>
>> Documentation/devicetree/bindings/regulator/regulator.txt says:
>
>> - regulator-boot-on: bootloader/firmware enabled regulator
>
>> I would suggest to add Linux kernel to that list of regulator
>> controllers, if it is the intention. In its current state the
>> documentation makes an impression that "regulator-boot-on" property
>> instructs the kernel to ignore regulator setup, since it is already
>> controlled by bootloader or firmware.
>
> No, not at all. It's referring to the state when Linux starts.
>

thank you for clarification, to grasp the underlying policy let me ask
for some more information.

If I want to enable a fixed regulator (not controlled by
bootloader/firmware) by Linux on boot or when fixed.ko module is bound,
shall I specify the same "regulator-boot-on" property? At least this is
the practical way to enable a fixed and/or gpio regulator right now, but
is it correct?

Or should the regulator always be enabled externally (assuming
"regulator-always-on" is omitted) after registration independently on
"regulator-boot-on" property?

--
With best wishes,
Vladimir
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