Re: [PATCH 3/4] arm64: dts: qcom: pm7250b: Enable Qualcomm BCL device

[Konrad Dybcio]

On 2/19/26 12:34 PM, Manaf Meethalavalappu Pallikunhi wrote:
> Hi Konrad,
> 
> On 2/16/2026 5:18 PM, Konrad Dybcio wrote:
>> On 2/13/26 12:55 PM, Manaf Meethalavalappu Pallikunhi wrote:
>>> Hi Konrad,
>>>
>>> On 2/6/2026 2:41 PM, Konrad Dybcio wrote:
>>>> On 2/5/26 10:14 PM, Manaf Meethalavalappu Pallikunhi wrote:
>>>>> Enable Qualcomm BCL hardware devicetree binding configuration
>>>>> for pm7250b.
>>>>>
>>>>> Signed-off-by: Manaf Meethalavalappu Pallikunhi <manaf.pallikunhi@xxxxxxxxxxxxxxxx>
>>>>> ---
>>>>>    arch/arm64/boot/dts/qcom/pm7250b.dtsi | 10 ++++++++++
>>>>>    1 file changed, 10 insertions(+)
>>>>>
>>>>> diff --git a/arch/arm64/boot/dts/qcom/pm7250b.dtsi b/arch/arm64/boot/dts/qcom/pm7250b.dtsi
>>>>> index 0761e6b5fd8d..69ad76831cde 100644
>>>>> --- a/arch/arm64/boot/dts/qcom/pm7250b.dtsi
>>>>> +++ b/arch/arm64/boot/dts/qcom/pm7250b.dtsi
>>>>> @@ -202,6 +202,16 @@ pm7250b_gpios: gpio@c000 {
>>>>>                interrupt-controller;
>>>>>                #interrupt-cells = <2>;
>>>>>            };
>>>>> +
>>>>> +        bcl@1d00 {
>>>>> +            compatible = "qcom,pm7250b-bcl", "qcom,bcl-v1";
>>>>> +            reg = <0x1d00>;
>>>>> +            interrupts = <PM7250B_SID 0x1d 0x0 IRQ_TYPE_EDGE_RISING>,
>>>>> +                     <PM7250B_SID 0x1d 0x1 IRQ_TYPE_EDGE_RISING>;
>>>>> +            interrupt-names = "bcl-max-min",
>>>>> +                      "bcl-critical";
>>>> We should strip the "bcl-" prefix, since these interrupts happen
>>>> to be under the bcl device
>>> Ack
>>>>
>>>>> +            overcurrent-thresholds-milliamp = <5500 6000>;
>>>> Is that something that we expect to change between boards, or is
>>>> that an electrical characteristic of the PM7250B?
>>> Yes,  It can change based on battery used for that board as these thresholds will be close below battery OCP spec.
>>> It is not based on pmic spec. Max current threshold support for specific pmic bcl is taken care in driver pmic data.
>>
>> Okay, so this property must not live in the common PMIC DTSI then..
> 
> Ack, I will move it into board file wherever it is required in next revision
> 
>>
>> I think ideally this could be communicated over battmgr, since it already
>> has a lot of information about the battery that's currently connected to
>> the device. Do you think that would be reasonable? Would you know who we
>> could talk to internally?
> 
> We are not adding any battery information here. This configuration is specifically for the BCL peripheral to monitor current and trigger an over‑current alarm. While the BCL settings are derived from battery specifications, they are not the same as the battery’s own limits,the BCL thresholds will always be set below the battery’s OCP specification.
> The intent of the BCL is to provide early detection of over‑current or under‑voltage conditions, notify the SoC/peripherals, and allow corrective action before the system ever reaches the battery’s actual protection limits.

Right, but as you say they are derived from the battery spec, I would
guesstimate it's something like "90% max current", so swapping out different
batteries for the same device could potentially affect this value. Since we
already have a place where OEMs are required to add the battery specs, I
would imagine this could be beneficial to move over to battmgr in the future

Konrad