| Message ID | 20200827140248.37749-1-sebastian.reichel@collabora.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
| Series | [PATCHv1] power: supply: document current direction | expand |
On Thu, 27 Aug 2020 16:02:48 +0200 Sebastian Reichel <sebastian.reichel@collabora.com> 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 <sebastian.reichel@collabora.com> > --- 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 <sebastian.reichel@collabora.com> 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 <sebastian.reichel@collabora.com> > > --- > > 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
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
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> --- Documentation/ABI/testing/sysfs-class-power | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)