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

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Message-ID: <fa258ad4-1efa-4fe8-9636-d70c5ea9c8e1@oss.qualcomm.com>
Date: Wed, 17 Sep 2025 13:14:26 +0200
From: Konrad Dybcio <konrad.dybcio@....qualcomm.com>
To: fenglin.wu@....qualcomm.com, Sebastian Reichel <sre@...nel.org>,
        Bjorn Andersson <andersson@...nel.org>,
        Konrad Dybcio <konradybcio@...nel.org>, Rob Herring <robh@...nel.org>,
        Krzysztof Kozlowski <krzk+dt@...nel.org>,
        Conor Dooley
 <conor+dt@...nel.org>,
        Heikki Krogerus <heikki.krogerus@...ux.intel.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Dmitry Baryshkov <dmitry.baryshkov@....qualcomm.com>,
        Bryan O'Donoghue <bryan.odonoghue@...aro.org>
Cc: Subbaraman Narayanamurthy <subbaraman.narayanamurthy@....qualcomm.com>,
        David Collins <david.collins@....qualcomm.com>,
        György Kurucz <me@...uczgy.com>,
        linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-arm-msm@...r.kernel.org, kernel@....qualcomm.com,
        devicetree@...r.kernel.org, linux-usb@...r.kernel.org
Subject: Re: [PATCH v5 9/9] power: supply: qcom_battmgr: handle charging state
 change notifications

On 9/17/25 12:15 PM, Fenglin Wu via B4 Relay wrote:
> From: Fenglin Wu <fenglin.wu@....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 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?

I think it also warrants a:

Reported-by: Sebastian Reichel <sebastian.reichel@...labora.com>

Konrad