From: Fenglin Wu <fenglin.wu@oss.qualcomm.com>
Add state_of_health power supply property to represent battery
health percentage.
Signed-off-by: Fenglin Wu <fenglin.wu@oss.qualcomm.com>
---
Documentation/ABI/testing/sysfs-class-power | 10 ++++++++++
drivers/power/supply/power_supply_sysfs.c | 1 +
include/linux/power_supply.h | 1 +
3 files changed, 12 insertions(+)
diff --git a/Documentation/ABI/testing/sysfs-class-power b/Documentation/ABI/testing/sysfs-class-power
index 22a565a6a1c509461b8c483e12975295765121d6..74e0d4d67467500c3cd62da3ae0b2e4a67e77680 100644
--- a/Documentation/ABI/testing/sysfs-class-power
+++ b/Documentation/ABI/testing/sysfs-class-power
@@ -562,6 +562,16 @@ Description:
Valid values: Represented in microohms
+What: /sys/class/power_supply/<supply_name>/state_of_health
+Date: May 2025
+Contact: linux-arm-msm@vger.kernel.org
+Description:
+ Reports battery power supply state of health in percentage.
+
+ Access: Read
+
+ Valid values: 0 - 100 (percent)
+
**USB Properties**
What: /sys/class/power_supply/<supply_name>/input_current_limit
diff --git a/drivers/power/supply/power_supply_sysfs.c b/drivers/power/supply/power_supply_sysfs.c
index dd829148eb6fda5dcd7eab53fc70f99081763714..12af0d0398822ff23d8970f6bdc8e3ef68081a1d 100644
--- a/drivers/power/supply/power_supply_sysfs.c
+++ b/drivers/power/supply/power_supply_sysfs.c
@@ -221,6 +221,7 @@ static struct power_supply_attr power_supply_attrs[] __ro_after_init = {
POWER_SUPPLY_ATTR(MANUFACTURE_MONTH),
POWER_SUPPLY_ATTR(MANUFACTURE_DAY),
POWER_SUPPLY_ATTR(RESISTANCE),
+ POWER_SUPPLY_ATTR(STATE_OF_HEALTH),
/* Properties of type `const char *' */
POWER_SUPPLY_ATTR(MODEL_NAME),
POWER_SUPPLY_ATTR(MANUFACTURER),
diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h
index de3e88810e322546470b21258913abc7707c86a7..dd0108940231352ac6c6f0fa962d1ea904d81c7a 100644
--- a/include/linux/power_supply.h
+++ b/include/linux/power_supply.h
@@ -175,6 +175,7 @@ enum power_supply_property {
POWER_SUPPLY_PROP_MANUFACTURE_MONTH,
POWER_SUPPLY_PROP_MANUFACTURE_DAY,
POWER_SUPPLY_PROP_RESISTANCE,
+ POWER_SUPPLY_PROP_STATE_OF_HEALTH,
/* Properties of type `const char *' */
POWER_SUPPLY_PROP_MODEL_NAME,
POWER_SUPPLY_PROP_MANUFACTURER,
--
2.34.1On Fri, May 30, 2025 at 03:35:07PM +0800, Fenglin Wu via B4 Relay wrote:
> From: Fenglin Wu <fenglin.wu@oss.qualcomm.com>
>
> Add state_of_health power supply property to represent battery
> health percentage.
>
> Signed-off-by: Fenglin Wu <fenglin.wu@oss.qualcomm.com>
> ---
> Documentation/ABI/testing/sysfs-class-power | 10 ++++++++++
> drivers/power/supply/power_supply_sysfs.c | 1 +
> include/linux/power_supply.h | 1 +
> 3 files changed, 12 insertions(+)
>
> diff --git a/Documentation/ABI/testing/sysfs-class-power b/Documentation/ABI/testing/sysfs-class-power
> index 22a565a6a1c509461b8c483e12975295765121d6..74e0d4d67467500c3cd62da3ae0b2e4a67e77680 100644
> --- a/Documentation/ABI/testing/sysfs-class-power
> +++ b/Documentation/ABI/testing/sysfs-class-power
> @@ -562,6 +562,16 @@ Description:
>
> Valid values: Represented in microohms
>
> +What: /sys/class/power_supply/<supply_name>/state_of_health
> +Date: May 2025
> +Contact: linux-arm-msm@vger.kernel.org
> +Description:
> + Reports battery power supply state of health in percentage.
> +
> + Access: Read
> +
> + Valid values: 0 - 100 (percent)
What does it mean that battery has 77% of health?
> +
> **USB Properties**
>
> What: /sys/class/power_supply/<supply_name>/input_current_limit
> diff --git a/drivers/power/supply/power_supply_sysfs.c b/drivers/power/supply/power_supply_sysfs.c
> index dd829148eb6fda5dcd7eab53fc70f99081763714..12af0d0398822ff23d8970f6bdc8e3ef68081a1d 100644
> --- a/drivers/power/supply/power_supply_sysfs.c
> +++ b/drivers/power/supply/power_supply_sysfs.c
> @@ -221,6 +221,7 @@ static struct power_supply_attr power_supply_attrs[] __ro_after_init = {
> POWER_SUPPLY_ATTR(MANUFACTURE_MONTH),
> POWER_SUPPLY_ATTR(MANUFACTURE_DAY),
> POWER_SUPPLY_ATTR(RESISTANCE),
> + POWER_SUPPLY_ATTR(STATE_OF_HEALTH),
> /* Properties of type `const char *' */
> POWER_SUPPLY_ATTR(MODEL_NAME),
> POWER_SUPPLY_ATTR(MANUFACTURER),
> diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h
> index de3e88810e322546470b21258913abc7707c86a7..dd0108940231352ac6c6f0fa962d1ea904d81c7a 100644
> --- a/include/linux/power_supply.h
> +++ b/include/linux/power_supply.h
> @@ -175,6 +175,7 @@ enum power_supply_property {
> POWER_SUPPLY_PROP_MANUFACTURE_MONTH,
> POWER_SUPPLY_PROP_MANUFACTURE_DAY,
> POWER_SUPPLY_PROP_RESISTANCE,
> + POWER_SUPPLY_PROP_STATE_OF_HEALTH,
> /* Properties of type `const char *' */
> POWER_SUPPLY_PROP_MODEL_NAME,
> POWER_SUPPLY_PROP_MANUFACTURER,
>
> --
> 2.34.1
>
>
--
With best wishes
Dmitry
On 6/2/2025 2:17 PM, Dmitry Baryshkov wrote:
> On Fri, May 30, 2025 at 03:35:07PM +0800, Fenglin Wu via B4 Relay wrote:
>> From: Fenglin Wu <fenglin.wu@oss.qualcomm.com>
>>
>> Add state_of_health power supply property to represent battery
>> health percentage.
>>
>> Signed-off-by: Fenglin Wu <fenglin.wu@oss.qualcomm.com>
>> ---
>> Documentation/ABI/testing/sysfs-class-power | 10 ++++++++++
>> drivers/power/supply/power_supply_sysfs.c | 1 +
>> include/linux/power_supply.h | 1 +
>> 3 files changed, 12 insertions(+)
>>
>> diff --git a/Documentation/ABI/testing/sysfs-class-power b/Documentation/ABI/testing/sysfs-class-power
>> index 22a565a6a1c509461b8c483e12975295765121d6..74e0d4d67467500c3cd62da3ae0b2e4a67e77680 100644
>> --- a/Documentation/ABI/testing/sysfs-class-power
>> +++ b/Documentation/ABI/testing/sysfs-class-power
>> @@ -562,6 +562,16 @@ Description:
>>
>> Valid values: Represented in microohms
>>
>> +What: /sys/class/power_supply/<supply_name>/state_of_health
>> +Date: May 2025
>> +Contact: linux-arm-msm@vger.kernel.org
>> +Description:
>> + Reports battery power supply state of health in percentage.
>> +
>> + Access: Read
>> +
>> + Valid values: 0 - 100 (percent)
> What does it mean that battery has 77% of health?
I will update this to explain it better:
Reports battery power supply state of health in percentage, indicating that the maximum charge capacity has degraded to that percentage of its original designed capacity.
>> +
>> **USB Properties**
>>
>> What: /sys/class/power_supply/<supply_name>/input_current_limit
>> diff --git a/drivers/power/supply/power_supply_sysfs.c b/drivers/power/supply/power_supply_sysfs.c
>> index dd829148eb6fda5dcd7eab53fc70f99081763714..12af0d0398822ff23d8970f6bdc8e3ef68081a1d 100644
>> --- a/drivers/power/supply/power_supply_sysfs.c
>> +++ b/drivers/power/supply/power_supply_sysfs.c
>> @@ -221,6 +221,7 @@ static struct power_supply_attr power_supply_attrs[] __ro_after_init = {
>> POWER_SUPPLY_ATTR(MANUFACTURE_MONTH),
>> POWER_SUPPLY_ATTR(MANUFACTURE_DAY),
>> POWER_SUPPLY_ATTR(RESISTANCE),
>> + POWER_SUPPLY_ATTR(STATE_OF_HEALTH),
>> /* Properties of type `const char *' */
>> POWER_SUPPLY_ATTR(MODEL_NAME),
>> POWER_SUPPLY_ATTR(MANUFACTURER),
>> diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h
>> index de3e88810e322546470b21258913abc7707c86a7..dd0108940231352ac6c6f0fa962d1ea904d81c7a 100644
>> --- a/include/linux/power_supply.h
>> +++ b/include/linux/power_supply.h
>> @@ -175,6 +175,7 @@ enum power_supply_property {
>> POWER_SUPPLY_PROP_MANUFACTURE_MONTH,
>> POWER_SUPPLY_PROP_MANUFACTURE_DAY,
>> POWER_SUPPLY_PROP_RESISTANCE,
>> + POWER_SUPPLY_PROP_STATE_OF_HEALTH,
>> /* Properties of type `const char *' */
>> POWER_SUPPLY_PROP_MODEL_NAME,
>> POWER_SUPPLY_PROP_MANUFACTURER,
>>
>> --
>> 2.34.1
>>
>>
On Tue, Jun 03, 2025 at 12:50:18PM +0800, Fenglin Wu wrote:
>
> On 6/2/2025 2:17 PM, Dmitry Baryshkov wrote:
> > On Fri, May 30, 2025 at 03:35:07PM +0800, Fenglin Wu via B4 Relay wrote:
> > > From: Fenglin Wu <fenglin.wu@oss.qualcomm.com>
> > >
> > > Add state_of_health power supply property to represent battery
> > > health percentage.
> > >
> > > Signed-off-by: Fenglin Wu <fenglin.wu@oss.qualcomm.com>
> > > ---
> > > Documentation/ABI/testing/sysfs-class-power | 10 ++++++++++
> > > drivers/power/supply/power_supply_sysfs.c | 1 +
> > > include/linux/power_supply.h | 1 +
> > > 3 files changed, 12 insertions(+)
> > >
> > > diff --git a/Documentation/ABI/testing/sysfs-class-power b/Documentation/ABI/testing/sysfs-class-power
> > > index 22a565a6a1c509461b8c483e12975295765121d6..74e0d4d67467500c3cd62da3ae0b2e4a67e77680 100644
> > > --- a/Documentation/ABI/testing/sysfs-class-power
> > > +++ b/Documentation/ABI/testing/sysfs-class-power
> > > @@ -562,6 +562,16 @@ Description:
> > > Valid values: Represented in microohms
> > > +What: /sys/class/power_supply/<supply_name>/state_of_health
> > > +Date: May 2025
> > > +Contact: linux-arm-msm@vger.kernel.org
> > > +Description:
> > > + Reports battery power supply state of health in percentage.
> > > +
> > > + Access: Read
> > > +
> > > + Valid values: 0 - 100 (percent)
> > What does it mean that battery has 77% of health?
>
> I will update this to explain it better:
>
> Reports battery power supply state of health in percentage, indicating that the maximum charge capacity has degraded to that percentage of its original designed capacity.
Which basically means that we don't need it in the first place, as we
can read capacity_full and capacity_full_design (or energy_full /
energy_full_design) and divide one onto another.
>
> > > +
> > > **USB Properties**
> > > What: /sys/class/power_supply/<supply_name>/input_current_limit
> > > diff --git a/drivers/power/supply/power_supply_sysfs.c b/drivers/power/supply/power_supply_sysfs.c
> > > index dd829148eb6fda5dcd7eab53fc70f99081763714..12af0d0398822ff23d8970f6bdc8e3ef68081a1d 100644
> > > --- a/drivers/power/supply/power_supply_sysfs.c
> > > +++ b/drivers/power/supply/power_supply_sysfs.c
> > > @@ -221,6 +221,7 @@ static struct power_supply_attr power_supply_attrs[] __ro_after_init = {
> > > POWER_SUPPLY_ATTR(MANUFACTURE_MONTH),
> > > POWER_SUPPLY_ATTR(MANUFACTURE_DAY),
> > > POWER_SUPPLY_ATTR(RESISTANCE),
> > > + POWER_SUPPLY_ATTR(STATE_OF_HEALTH),
> > > /* Properties of type `const char *' */
> > > POWER_SUPPLY_ATTR(MODEL_NAME),
> > > POWER_SUPPLY_ATTR(MANUFACTURER),
> > > diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h
> > > index de3e88810e322546470b21258913abc7707c86a7..dd0108940231352ac6c6f0fa962d1ea904d81c7a 100644
> > > --- a/include/linux/power_supply.h
> > > +++ b/include/linux/power_supply.h
> > > @@ -175,6 +175,7 @@ enum power_supply_property {
> > > POWER_SUPPLY_PROP_MANUFACTURE_MONTH,
> > > POWER_SUPPLY_PROP_MANUFACTURE_DAY,
> > > POWER_SUPPLY_PROP_RESISTANCE,
> > > + POWER_SUPPLY_PROP_STATE_OF_HEALTH,
> > > /* Properties of type `const char *' */
> > > POWER_SUPPLY_PROP_MODEL_NAME,
> > > POWER_SUPPLY_PROP_MANUFACTURER,
> > >
> > > --
> > > 2.34.1
> > >
> > >
--
With best wishes
Dmitry
On 6/3/2025 6:35 PM, Dmitry Baryshkov wrote: >>>> +What: /sys/class/power_supply/<supply_name>/state_of_health >>>> +Date: May 2025 >>>> +Contact: linux-arm-msm@vger.kernel.org >>>> +Description: >>>> + Reports battery power supply state of health in percentage. >>>> + >>>> + Access: Read >>>> + >>>> + Valid values: 0 - 100 (percent) >>> What does it mean that battery has 77% of health? >> I will update this to explain it better: >> >> Reports battery power supply state of health in percentage, indicating that the maximum charge capacity has degraded to that percentage of its original designed capacity. > Which basically means that we don't need it in the first place, as we > can read capacity_full and capacity_full_design (or energy_full / > energy_full_design) and divide one onto another. Hmm, it is true in general to quantify how the battery performance has degraded over time. However, estimating and calculating for battery state of health is much more complicated I think. I am not an expert, but as far as I know, different battery management systems might have different algorithms to calculate the battery health and report it in as percentage. For example, in Qcom battery management firmware, a "soh" parameter is provided as the battery health percentage based on the real-time calculations from learning capacity, resistance estimation, etc.
On Thu, Jun 05, 2025 at 02:08:30PM +0800, Fenglin Wu wrote: > > On 6/3/2025 6:35 PM, Dmitry Baryshkov wrote: > > > > > +What: /sys/class/power_supply/<supply_name>/state_of_health > > > > > +Date: May 2025 > > > > > +Contact: linux-arm-msm@vger.kernel.org > > > > > +Description: > > > > > + Reports battery power supply state of health in percentage. > > > > > + > > > > > + Access: Read > > > > > + > > > > > + Valid values: 0 - 100 (percent) > > > > What does it mean that battery has 77% of health? > > > I will update this to explain it better: > > > > > > Reports battery power supply state of health in percentage, indicating that the maximum charge capacity has degraded to that percentage of its original designed capacity. > > Which basically means that we don't need it in the first place, as we > > can read capacity_full and capacity_full_design (or energy_full / > > energy_full_design) and divide one onto another. > > Hmm, it is true in general to quantify how the battery performance has > degraded over time. However, estimating and calculating for battery state of > health is much more complicated I think. I am not an expert, but as far as I > know, different battery management systems might have different algorithms > to calculate the battery health and report it in as percentage. For example, > in Qcom battery management firmware, a "soh" parameter is provided as the > battery health percentage based on the real-time calculations from learning > capacity, resistance estimation, etc. Ack, this is more than just full / full_design. Please consider expanding ABI description (though in the vendor-neutral way). -- With best wishes Dmitry
Hi, On Thu, Jun 05, 2025 at 09:34:14AM +0300, Dmitry Baryshkov wrote: > On Thu, Jun 05, 2025 at 02:08:30PM +0800, Fenglin Wu wrote: > > > > On 6/3/2025 6:35 PM, Dmitry Baryshkov wrote: > > > > > > +What: /sys/class/power_supply/<supply_name>/state_of_health > > > > > > +Date: May 2025 > > > > > > +Contact: linux-arm-msm@vger.kernel.org > > > > > > +Description: > > > > > > + Reports battery power supply state of health in percentage. > > > > > > + > > > > > > + Access: Read > > > > > > + > > > > > > + Valid values: 0 - 100 (percent) > > > > > What does it mean that battery has 77% of health? > > > > I will update this to explain it better: > > > > > > > > Reports battery power supply state of health in percentage, indicating that the maximum charge capacity has degraded to that percentage of its original designed capacity. > > > Which basically means that we don't need it in the first place, as we > > > can read capacity_full and capacity_full_design (or energy_full / > > > energy_full_design) and divide one onto another. > > > > Hmm, it is true in general to quantify how the battery performance has > > degraded over time. However, estimating and calculating for battery state of > > health is much more complicated I think. I am not an expert, but as far as I > > know, different battery management systems might have different algorithms > > to calculate the battery health and report it in as percentage. For example, > > in Qcom battery management firmware, a "soh" parameter is provided as the > > battery health percentage based on the real-time calculations from learning > > capacity, resistance estimation, etc. > > Ack, this is more than just full / full_design. Please consider > expanding ABI description (though in the vendor-neutral way). No, Dmitry was right. It is exactly the same. Estimating the battery state of health information is indeed tricky and complicated. The reason for that is that estimating and calculating POWER_SUPPLY_PROP_CHARGE_FULL/POWER_SUPPLY_PROP_ENERGY_FULL (i.e. not the *_FULL_DESIGN) is complicated :) Greetings, -- Sebastian
On 6/22/2025 9:17 AM, Sebastian Reichel wrote: > Hi, > > On Thu, Jun 05, 2025 at 09:34:14AM +0300, Dmitry Baryshkov wrote: >> On Thu, Jun 05, 2025 at 02:08:30PM +0800, Fenglin Wu wrote: >>> On 6/3/2025 6:35 PM, Dmitry Baryshkov wrote: >>>>>>> +What: /sys/class/power_supply/<supply_name>/state_of_health >>>>>>> +Date: May 2025 >>>>>>> +Contact: linux-arm-msm@vger.kernel.org >>>>>>> +Description: >>>>>>> + Reports battery power supply state of health in percentage. >>>>>>> + >>>>>>> + Access: Read >>>>>>> + >>>>>>> + Valid values: 0 - 100 (percent) >>>>>> What does it mean that battery has 77% of health? >>>>> I will update this to explain it better: >>>>> >>>>> Reports battery power supply state of health in percentage, indicating that the maximum charge capacity has degraded to that percentage of its original designed capacity. >>>> Which basically means that we don't need it in the first place, as we >>>> can read capacity_full and capacity_full_design (or energy_full / >>>> energy_full_design) and divide one onto another. >>> Hmm, it is true in general to quantify how the battery performance has >>> degraded over time. However, estimating and calculating for battery state of >>> health is much more complicated I think. I am not an expert, but as far as I >>> know, different battery management systems might have different algorithms >>> to calculate the battery health and report it in as percentage. For example, >>> in Qcom battery management firmware, a "soh" parameter is provided as the >>> battery health percentage based on the real-time calculations from learning >>> capacity, resistance estimation, etc. >> Ack, this is more than just full / full_design. Please consider >> expanding ABI description (though in the vendor-neutral way). > No, Dmitry was right. It is exactly the same. > > Estimating the battery state of health information is indeed tricky > and complicated. The reason for that is that estimating and > calculating POWER_SUPPLY_PROP_CHARGE_FULL/POWER_SUPPLY_PROP_ENERGY_FULL > (i.e. not the *_FULL_DESIGN) is complicated :) > > Greetings, > > -- Sebastian Hi Sebastian, Thanks for the comment. In the qcom_battmgr driver, both POWER_SUPPLY_PROP_CHARGE_FULL and POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN properties are already supported, and CHARGE_FULL is used to represent the learned battery capacity calculated in Qcom BMS. Additionally, the Qcom BMS calculates a comprehensive battery SOH parameter by considering multiple factors, such as changes in battery impedance, learned capacity over time, and charging/discharging cycles. Such as, for the battery impedance change, it is specially important for calculating SOH in scenarios with high load or low temperatures, as only part of the CHARGE_FULL capacity may be usable due to significant voltage drops, especially in aged batteries. Hence, we proposed adding "state_of_health" support in power supply ABI to expose this parameter provided in Qcom BMS which is different from the calculation of charge_full / charge_full_design. Also, Android battery management code [1] is expecting "state_of_health" power supply property and it can use it if it's available. [1] https://android.googlesource.com/platform/system/core/+/refs/heads/main/healthd/BatteryMonitor.cpp#927 Thanks Fenglin
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