[PATCH] Expose ACPI battery "measurement accuracy" property to sysfs.

[Brennan Vincent <brennan@xxxxxxxxxxxxxx>]

This property, expressed in thousands of a percent,
reports how accurate the device claims its
capacity metrics to be. It may be useful for battery
monitoring tools.
---
 drivers/acpi/battery.c                    | 7 +++++++
 drivers/power/supply/power_supply_sysfs.c | 1 +
 include/linux/power_supply.h              | 1 +
 3 files changed, 9 insertions(+)

diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
index 306513fec1e1..933f3de4dd67 100644
--- a/drivers/acpi/battery.c
+++ b/drivers/acpi/battery.c
@@ -300,6 +300,9 @@ static int acpi_battery_get_property(struct power_supply *psy,
 	case POWER_SUPPLY_PROP_SERIAL_NUMBER:
 		val->strval = battery->serial_number;
 		break;
+	case POWER_SUPPLY_PROP_MEASUREMENT_ACCURACY:
+		val->intval = battery->measurement_accuracy;
+		break;
 	default:
 		ret = -EINVAL;
 	}
@@ -322,6 +325,7 @@ static enum power_supply_property charge_battery_props[] = {
 	POWER_SUPPLY_PROP_MODEL_NAME,
 	POWER_SUPPLY_PROP_MANUFACTURER,
 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
+	POWER_SUPPLY_PROP_MEASUREMENT_ACCURACY,
 };

 static enum power_supply_property charge_battery_full_cap_broken_props[] = {
@@ -336,6 +340,7 @@ static enum power_supply_property charge_battery_full_cap_broken_props[] = {
 	POWER_SUPPLY_PROP_MODEL_NAME,
 	POWER_SUPPLY_PROP_MANUFACTURER,
 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
+	POWER_SUPPLY_PROP_MEASUREMENT_ACCURACY,
 };

 static enum power_supply_property energy_battery_props[] = {
@@ -354,6 +359,7 @@ static enum power_supply_property energy_battery_props[] = {
 	POWER_SUPPLY_PROP_MODEL_NAME,
 	POWER_SUPPLY_PROP_MANUFACTURER,
 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
+	POWER_SUPPLY_PROP_MEASUREMENT_ACCURACY,
 };

 static enum power_supply_property energy_battery_full_cap_broken_props[] = {
@@ -368,6 +374,7 @@ static enum power_supply_property energy_battery_full_cap_broken_props[] = {
 	POWER_SUPPLY_PROP_MODEL_NAME,
 	POWER_SUPPLY_PROP_MANUFACTURER,
 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
+	POWER_SUPPLY_PROP_MEASUREMENT_ACCURACY,
 };

 /* Battery Management */
diff --git a/drivers/power/supply/power_supply_sysfs.c b/drivers/power/supply/power_supply_sysfs.c
index 4239591e1522..844dbd61295f 100644
--- a/drivers/power/supply/power_supply_sysfs.c
+++ b/drivers/power/supply/power_supply_sysfs.c
@@ -220,6 +220,7 @@ static struct power_supply_attr power_supply_attrs[] = {
 	POWER_SUPPLY_ATTR(MODEL_NAME),
 	POWER_SUPPLY_ATTR(MANUFACTURER),
 	POWER_SUPPLY_ATTR(SERIAL_NUMBER),
+	POWER_SUPPLY_ATTR(MEASUREMENT_ACCURACY),
 };

 static struct attribute *
diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h
index cb380c1d9459..4c48ee26f1b5 100644
--- a/include/linux/power_supply.h
+++ b/include/linux/power_supply.h
@@ -174,6 +174,7 @@ enum power_supply_property {
 	POWER_SUPPLY_PROP_MODEL_NAME,
 	POWER_SUPPLY_PROP_MANUFACTURER,
 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
+	POWER_SUPPLY_PROP_MEASUREMENT_ACCURACY,
 };

 enum power_supply_type {
--
2.34.1