Re: [PATCH 1/2] dt-bindings: soc: qcom: pmic-glink: Document batteryless property

[Krzysztof Kozlowski <krzk@kernel.org>]

On 21/05/2026 09:13, Kamal Wadhwa wrote:
> On Tue, May 19, 2026 at 12:35:13PM +0200, Krzysztof Kozlowski wrote:
>> On Tue, May 19, 2026 at 01:55:26PM +0530, Rakesh Kota wrote:
>>>
>>>> And isn't lack of monitored battery property enough to indicate that?
>>>
>>> Regarding monitored-battery — its absence alone isn't sufficient. The
>>> BATT_ID line on debug boards is pulled to ~10kΩ, which is used during
>>> development phase where some battery properties are still present. The
>>> same ~10kΩ value is also used on some genuinely battery-less production
>>> platforms where no battery properties exist, making auto-detection
>>> unreliable. Hence the need for an explicit DT property to identify
>>> hardware platforms where no battery populated. 
>>
>> I don't understand this logic. So you claim you have debug boards which
>> do not have battery, but define monitored-battery? Then these are wrong
>> and fix them first.
> 
> Actually our firmware treats the debug board as a "fake battery" rather then
> a "no-battery" case.
> 
> This is done to avoid triggering shutdown or trigger power/thermal related
> mitigations to kick in from the HLOS (android) that is configured mainly for
> battery-backed devices.
> 
> Note that we can know if its a debug board, just by looking at the battery
> ID resistance or the battery profile name in the power supply properties
> for `qcom-battmgr-bat` in sysfs.
> 
> However, the problem started with the boards that are battery-less and
> unfortunetely used the same debug board batt ID resistance value, so from
> the firmware side the batteryless board is also seen same as a board with
> debug-board connected.
> 
> Since firmware does not have a way to dynamically tell if it on a
> debug-board powered device or a DCIN powered device, We are required to
> add this new DT property.

Neither debug-board powered device nor battery-less will have
monitored-battery, thus again, why lack of that property cannot tell you
what you need?

And no, you are not required to add a new DT property. Every wrong
property was also justified like that...

Best regards,
Krzysztof