[PATCHv1 02/19] power: supply: core: add capacity error margin property

[Sebastian Reichel <sebastian.reichel@collabora.com>]

Add a property for reporting the error margin expected
by fuel gauge chips.

Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
---
 Documentation/ABI/testing/sysfs-class-power | 15 +++++++++++++++
 drivers/power/supply/power_supply_sysfs.c   |  1 +
 include/linux/power_supply.h                |  1 +
 3 files changed, 17 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-class-power b/Documentation/ABI/testing/sysfs-class-power
index bf3b48f022dc..2f896555ae23 100644
--- a/Documentation/ABI/testing/sysfs-class-power
+++ b/Documentation/ABI/testing/sysfs-class-power
@@ -74,6 +74,21 @@ Description:
 		Access: Read, Write
 		Valid values: 0 - 100 (percent)
 
+What:		/sys/class/power_supply/<supply_name>/capacity_error_margin
+Date:		April 2019
+Contact:	linux-pm@vger.kernel.org
+Description:
+		Battery capacity measurement becomes unreliable without
+		recalibration. This values provides the maximum error
+		margin expected to exist by the fuel gauge in percent.
+		Values close to 0% will be returned after (re-)calibration
+		has happened. Over time the error margin will increase.
+		100% means, that the capacity related values are basically
+		completely useless.
+
+		Access: Read
+		Valid values: 0 - 100 (percent)
+
 What:		/sys/class/power_supply/<supply_name>/capacity_level
 Date:		June 2009
 Contact:	linux-pm@vger.kernel.org
diff --git a/drivers/power/supply/power_supply_sysfs.c b/drivers/power/supply/power_supply_sysfs.c
index d21b4e0edf38..e664774a2d1e 100644
--- a/drivers/power/supply/power_supply_sysfs.c
+++ b/drivers/power/supply/power_supply_sysfs.c
@@ -178,6 +178,7 @@ static struct power_supply_attr power_supply_attrs[] = {
 	POWER_SUPPLY_ATTR(CAPACITY),
 	POWER_SUPPLY_ATTR(CAPACITY_ALERT_MIN),
 	POWER_SUPPLY_ATTR(CAPACITY_ALERT_MAX),
+	POWER_SUPPLY_ATTR(CAPACITY_ERROR_MARGIN),
 	POWER_SUPPLY_ENUM_ATTR(CAPACITY_LEVEL),
 	POWER_SUPPLY_ATTR(TEMP),
 	POWER_SUPPLY_ATTR(TEMP_MAX),
diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h
index 1f60731ec7fe..453a85f25635 100644
--- a/include/linux/power_supply.h
+++ b/include/linux/power_supply.h
@@ -139,6 +139,7 @@ enum power_supply_property {
 	POWER_SUPPLY_PROP_CAPACITY, /* in percents! */
 	POWER_SUPPLY_PROP_CAPACITY_ALERT_MIN, /* in percents! */
 	POWER_SUPPLY_PROP_CAPACITY_ALERT_MAX, /* in percents! */
+	POWER_SUPPLY_PROP_CAPACITY_ERROR_MARGIN, /* in percents! */
 	POWER_SUPPLY_PROP_CAPACITY_LEVEL,
 	POWER_SUPPLY_PROP_TEMP,
 	POWER_SUPPLY_PROP_TEMP_MAX,
-- 
2.26.2