Re: [PATCH 2/2] dt-bindings: mfd: cros-ec: add properties for thermal cooling cells
From: Krzysztof Kozlowski
Date: Mon Nov 25 2024 - 02:32:36 EST
On 25/11/2024 03:50, Sung-Chi, Li wrote:
> On Fri, Nov 22, 2024 at 08:49:14AM +0100, Krzysztof Kozlowski wrote:
>> On Fri, Nov 22, 2024 at 11:47:22AM +0800, Sung-Chi Li wrote:
>>> The cros_ec supports limiting the input current to act as a passive
>>> thermal cooling device. Add the property '#cooling-cells' bindings, such
>>> that thermal framework can recognize cros_ec as a valid thermal cooling
>>> device.
>>>
>>> Signed-off-by: Sung-Chi Li <lschyi@xxxxxxxxxxxx>
>>> ---
>>> Documentation/devicetree/bindings/mfd/google,cros-ec.yaml | 3 +++
>>> 1 file changed, 3 insertions(+)
>>>
>>> diff --git a/Documentation/devicetree/bindings/mfd/google,cros-ec.yaml b/Documentation/devicetree/bindings/mfd/google,cros-ec.yaml
>>> index aac8819bd00b..2b6f098057af 100644
>>> --- a/Documentation/devicetree/bindings/mfd/google,cros-ec.yaml
>>> +++ b/Documentation/devicetree/bindings/mfd/google,cros-ec.yaml
>>> @@ -96,6 +96,9 @@ properties:
>>> '#gpio-cells':
>>> const: 2
>>>
>>> + '#cooling-cells':
>>> + const: 2
>>
>> This is not a cooling device. BTW, your commit msg is somehow circular.
>> "Add cooling to make it a cooling device because it will be then cooling
>> device."
>>
>> Power supply already provides necessary framework for managing charging
>> current and temperatures. If this is to stay, you need to explain why
>> this is suitable to be considered a thermal zone or system cooling
>> device (not power supply or input power cooling).
>>
>> Best regards,
>> Krzysztof
>>
>
> Thank you, I will rephrase the commit message. The reason to not to use the
> managing charging current and temperatures in the power supply framework is
> that:
>
> - The EC may not have the thermal sensor value for the charger, and there is no
> protocol for getting the thermal sensor value for the charger (there is
> command for reading thermal sensor values, but there is no specification for
> what sensor index is for the charger, if the charger provides thermal value).
> - The managing mechanism only take the charger thermal value into account, and
> I would like to control the current based on the thermal condition of the
> whole device.
>
> I will include these explanation in the following changes.
This does not explain me why this is supposed to be thermal zone. I
already said it, but let's repeat: This is not a thermal zone. This
isn't thermal zone sensor, either.
Best regards,
Krzysztof