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 <[email protected]>
---
Documentation/ABI/testing/sysfs-class-power | 6 ++++--
1 file 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
--
2.28.0
On Thu, 27 Aug 2020 16:02:48 +0200
Sebastian Reichel <[email protected]> wrote:
> 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 <[email protected]>
> ---
would be nice if this comes in, so that is it clearly specified.
Regards,
Andreas
Hi,
On Fri, Oct 02, 2020 at 06:23:03PM +0200, Andreas Kemnade wrote:
> On Thu, 27 Aug 2020 16:02:48 +0200
> Sebastian Reichel <[email protected]> wrote:
>
> > 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 <[email protected]>
> > ---
>
> would be nice if this comes in, so that is it clearly specified.
Ack, I'm a bit late picking up patches this merge window due to a
vacation. This has been queued now.
-- Sebastian