Re: [PATCH v3 2/2] dt-bindings: mfd: Add properties for thermal sensor cells

[Krzysztof Kozlowski <krzk@kernel.org>]

On 25/11/2024 16:13, Guenter Roeck wrote:
> On 11/25/24 00:52, Krzysztof Kozlowski wrote:
>> On 13/11/2024 04:05, Guenter Roeck wrote:
>>> On 11/12/24 18:39, Sung-Chi, Li wrote:
>>>> The cros_ec supports reading thermal values from thermal sensors
>>>> connect to it. Add the property '#thermal-sensor-cells' bindings, such
>>>> that thermal framework can recognize cros_ec as a valid thermal device.
>>>>
>>>> Signed-off-by: Sung-Chi, Li <lschyi@chromium.org>
>>>> Acked-by: Conor Dooley <conor.dooley@microchip.com>
>>>> ---
>>>>    Changes in v2:
>>>>      - Add changes for DTS binding.
>>>>    Changes in v3:
>>>>      - Remove unneeded Change-Id tag in commit message.
>>>> ---
>>>
>>> I can't apply this one (not in hwmon space), so
>>>
>>> Acked-by: Guenter Roeck <linux@roeck-us.net>
>>>
>>> with the assumption that Lee will pick it up.
>>
>> This was merged, while I was AFK, so the ship has sailed, but let me
>> state here objection for any future discussions:
>>
>> NAK, this is not a thermal sensor. The commit msg explains what they
>> want to achieve, but that's not a valid reason to add property from
>> different class of devices.
>>
>> This is some hardware/temperature monitoring device or power supply, not
>> part of SoC, not integrated into any SoC thermal zone. Calling it
> 
> I am confused. We have several thermal sensors registering as thermal
> zone, and fan controllers registering themselves as thermal cooling devices.
> 
> Are you saying that this is all not permitted because they are not part
> of a SoC ?


These are fine, because they monitor or cool down the SoC.  Sensor can
be under the die.  Fan for battery or for battery charger also would be
fine, because it is a real cooling device.  It literally cools.

But treating battery charger as cooling device is not correct, IMHO.
Battery charger does not cool anything down and already we have there
properties for managing thermal and current aspects.

BTW, if power supply bindings miss some thermal aspects, then let's grow
the common binding first and agree on common aspects.


Best regards,
Krzysztof