[PATCH v5 2/9] power: supply: core: Add state_of_health power supply property

[Fenglin Wu via B4 Relay <devnull+fenglin.wu.oss.qualcomm.com@kernel.org>]

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 | 21 +++++++++++++++++++++
 drivers/power/supply/power_supply_sysfs.c   |  1 +
 include/linux/power_supply.h                |  1 +
 3 files changed, 23 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-class-power b/Documentation/ABI/testing/sysfs-class-power
index cea1a38f5a8fb754d4e6323967ef6cf2e20a68ce..d9e1ad7646f14892bb7ed55ac72d0de7569f104e 100644
--- a/Documentation/ABI/testing/sysfs-class-power
+++ b/Documentation/ABI/testing/sysfs-class-power
@@ -568,6 +568,27 @@ Description:
 
 		Valid values: Represented in microohms
 
+What:		/sys/class/power_supply/<supply_name>/state_of_health
+Date:		August 2025
+Contact:	linux-arm-msm@vger.kernel.org
+Description:
+		The state_of_health parameter quantifies the overall condition
+		of a battery as a percentage, reflecting its ability to deliver
+		rated performance relative to its original specifications. It is
+		dynamically computed using a combination of learned capacity
+		and impedance-based degradation indicators, both of which evolve
+		over the battery's lifecycle.
+		Note that the exact algorithms are kept secret by most battery
+		vendors and the value from different battery vendors cannot be
+		compared with each other as there is no vendor-agnostic definition
+		of "performance". Also this usually cannot be used for any
+		calculations (i.e. this is not the factor between charge_full and
+		charge_full_design).
+
+		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 cfa8f90a88ebc8fc1c7447198f138e5d2e699e5a..d96a8578308e3af60cc1a352845662aa922c29b3 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(INTERNAL_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 8bc3b7a67eb5693a16db9b7d123e7881711c6bf4..ccb43fe44381965069dc3bd9505d45050b9b1bd8 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_INTERNAL_RESISTANCE,
+	POWER_SUPPLY_PROP_STATE_OF_HEALTH,
 	/* Properties of type `const char *' */
 	POWER_SUPPLY_PROP_MODEL_NAME,
 	POWER_SUPPLY_PROP_MANUFACTURER,

-- 
2.34.1