[PATCH v3 1/4] power: supply: core: Introduce one property to present the battery internal resistance

[Baolin Wang]

The internal resistance of a battery is not a constant in its life cycle,
this varies over the age of the battery or temperature and so on. But we
just want use one constant battery internal resistance to estimate the
battery capacity. Thus this patch introduces one property to present
the battery factory internal resistance for battery information.

Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxx>
---
Changes from v2:
 - Rename the property.
 - Improve the commit message.

Changes from v1:
 - New patch in v2.
---
 .../devicetree/bindings/power/supply/battery.txt   |    2 ++
 drivers/power/supply/power_supply_core.c           |    3 +++
 include/linux/power_supply.h                       |    1 +
 3 files changed, 6 insertions(+)

diff --git a/Documentation/devicetree/bindings/power/supply/battery.txt b/Documentation/devicetree/bindings/power/supply/battery.txt
index f4d3b4a..938d027 100644
--- a/Documentation/devicetree/bindings/power/supply/battery.txt
+++ b/Documentation/devicetree/bindings/power/supply/battery.txt
@@ -22,6 +22,7 @@ Optional Properties:
  - charge-term-current-microamp: current for charge termination phase
  - constant-charge-current-max-microamp: maximum constant input current
  - constant-charge-voltage-max-microvolt: maximum constant input voltage
+ - factory-internal-resistance-micro-ohms: battery factory internal resistance
 
 Battery properties are named, where possible, for the corresponding
 elements in enum power_supply_property, defined in
@@ -42,6 +43,7 @@ Example:
 		charge-term-current-microamp = <128000>;
 		constant-charge-current-max-microamp = <900000>;
 		constant-charge-voltage-max-microvolt = <4200000>;
+		factory-internal-resistance-micro-ohms = <250000>;
 	};
 
 	charger: charger@11 {
diff --git a/drivers/power/supply/power_supply_core.c b/drivers/power/supply/power_supply_core.c
index e853618..307e0995 100644
--- a/drivers/power/supply/power_supply_core.c
+++ b/drivers/power/supply/power_supply_core.c
@@ -579,6 +579,7 @@ int power_supply_get_battery_info(struct power_supply *psy,
 	info->charge_term_current_ua         = -EINVAL;
 	info->constant_charge_current_max_ua = -EINVAL;
 	info->constant_charge_voltage_max_uv = -EINVAL;
+	info->factory_internal_resistance_uohm  = -EINVAL;
 
 	if (!psy->of_node) {
 		dev_warn(&psy->dev, "%s currently only supports devicetree\n",
@@ -616,6 +617,8 @@ int power_supply_get_battery_info(struct power_supply *psy,
 			     &info->constant_charge_current_max_ua);
 	of_property_read_u32(battery_np, "constant_charge_voltage_max_microvolt",
 			     &info->constant_charge_voltage_max_uv);
+	of_property_read_u32(battery_np, "factory-internal-resistance-micro-ohms",
+			     &info->factory_internal_resistance_uohm);
 
 	return 0;
 }
diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h
index f807691..d089566 100644
--- a/include/linux/power_supply.h
+++ b/include/linux/power_supply.h
@@ -326,6 +326,7 @@ struct power_supply_battery_info {
 	int charge_term_current_ua;	    /* microAmps */
 	int constant_charge_current_max_ua; /* microAmps */
 	int constant_charge_voltage_max_uv; /* microVolts */
+	int factory_internal_resistance_uohm;   /* microOhms */
 };
 
 extern struct atomic_notifier_head power_supply_notifier;
-- 
1.7.9.5