diff options
| author | Sebastian Reichel <sebastian.reichel@collabora.com> | 2020-08-27 16:02:48 +0200 |
|---|---|---|
| committer | Sebastian Reichel <sebastian.reichel@collabora.com> | 2020-10-03 12:46:22 +0200 |
| commit | 05f94eb989075f6e5cd99d0772ea160efe41bff4 (patch) | |
| tree | 6b1c20804ccdb80ee33e410e041714c481b79b2f /Documentation/ABI | |
| parent | 41a7431dbaa37533c3b732cdea425a7b8f2d4162 (diff) | |
power: supply: document current direction
Currently the sign for CURRENT_NOW and CURRENT_AVG is a bit
of a mess. There are basically 3 different ways battery fuel
gauges report the current:
1. uses negative values for discharging and positive values
for charging
2. uses positive values for discharging and negative values
for discharging (opposit of 1)
3. only uses positive values
As a result userspace currently cannot use the sign at all in
a generic way. Let's solve the issue by documenting a canonical
way for reporting the data and ensure new drivers follow this
way. Then existing drivers can be fixed on a case-by-case basis.
The 'negative value = battery discharging' has been choosen,
since there are only very few drivers doing it the other way
around.
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Diffstat (limited to 'Documentation/ABI')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-class-power | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/Documentation/ABI/testing/sysfs-class-power b/Documentation/ABI/testing/sysfs-class-power index 651599fb18f8..dbccb2fcd7ce 100644 --- a/Documentation/ABI/testing/sysfs-class-power +++ b/Documentation/ABI/testing/sysfs-class-power @@ -108,7 +108,8 @@ Description: which they average readings to smooth out the reported value. Access: Read - Valid values: Represented in microamps + Valid values: Represented in microamps. Negative values are used + for discharging batteries, positive values for charging batteries. What: /sys/class/power_supply/<supply_name>/current_max Date: October 2010 @@ -127,7 +128,8 @@ Description: This value is not averaged/smoothed. Access: Read - Valid values: Represented in microamps + Valid values: Represented in microamps. Negative values are used + for discharging batteries, positive values for charging batteries. What: /sys/class/power_supply/<supply_name>/charge_control_limit Date: Oct 2012 |