Re: [PATCH v5 9/9] power: supply: qcom_battmgr: handle charging state change notifications

[Fenglin Wu <fenglin.wu@oss.qualcomm.com>]

On 9/17/2025 7:14 PM, Konrad Dybcio wrote:
> On 9/17/25 12:15 PM, Fenglin Wu via B4 Relay wrote:
>> From: Fenglin Wu <fenglin.wu@oss.qualcomm.com>
>>
>> The X1E80100 battery management firmware sends a notification with
>> code 0x83 when the battery charging state changes, such as switching
>> between fast charge, taper charge, end of charge, or any other error
>> charging states. The same notification code is used with bit[16] set
>> if charging stops due to reaching the charge control end threshold.
>> Additionally, a 2-bit value is added in bit[18:17] with the same code
>> and used to indicate the charging source capability: a value of 2
>> represents a strong charger, 1 is a weak charger, and 0 is no charging
>> source. The 3-MSB [18:16] in the notification code is not much useful
>> for now, hence just ignore them and trigger a power supply change event
>> whenever 0x83 notification code is received. This helps to eliminate the
>> unknown notification error messages.
> Thank you for explaining the technical background.
>
> Please hit enter somewhere in your commit message, this is a very
> long paragraph, making it difficult to read.
I just realized I made a mistake on the bit position, it should be 
bit[8] for reaching to the charge control threshold, bit[10:9] for 
charging source capability. I don't know what I was thinking when 
writing the commit text :(. I will correct them in the next patch.
>
> I believe this maps to:
>
> 0 -> POWER_SUPPLY_CHARGE_TYPE_NONE
> 1 -> POWER_SUPPLY_CHARGE_TYPE_TRICKLE
> 2 -> POWER_SUPPLY_CHARGE_TYPE_FAST (or _STANDARD, I see battmgr code
> reports them both as 2)
>
> However, we already set it to none/trickle/standard(taper) based on
> the usual notifications, so I'm not sure if these are more common or
> arrive outside the normal state changes - if so, perhaps we can take
> them into account as well?

This is not related with the real charging status. I double checked in 
the battery management firmware, it is checking the charging source 
power capability by multiplying maximum voltage and current reading from 
the PDOs. Any charger adapter with a maximum power below 60W is 
identified as a slow/weak charger.

>
> I think it also warrants a:
>
> Reported-by: Sebastian Reichel <sebastian.reichel@collabora.com>
ACK
> Konrad