Re: [PATCH 01/10] power: supply: Add sysfs entry for system load control

[Sebastian Reichel <sre@kernel.org>]

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Hi,

On Wed, Jul 01, 2026 at 11:23:02AM +0200, Waqar Hameed wrote:
> On Mon, Jun 29, 2026 at 17:44 +0200 Waqar Hameed <waqar.hameed@axis.com> wrote:
> 
> [...]
> 
> > diff --git a/Documentation/ABI/testing/sysfs-class-power b/Documentation/ABI/testing/sysfs-class-power
> > index 32697b926cc8c..2287b207311cd 100644
> > --- a/Documentation/ABI/testing/sysfs-class-power
> > +++ b/Documentation/ABI/testing/sysfs-class-power
> > @@ -590,6 +590,30 @@ Description:
> >  
> >  		Valid values: 0 - 100 (percent)
> >  
> > +What:		/sys/class/power_supply/<supply_name>/load_switch
> > +Date:		June 2026
> > +Contact:	linux-pm@vger.kernel.org
> > +Description:
> > +		Devices can control the connection from power to system load.
> > +		For example, with a field-effect transistor between a battery
> > +		and the system load (BATFET). This entry controls such switch.
> > +		The obvious states are "on" and "off", i.e. there is a
> > +		connection or not, respectively. However, many devices can also
> > +		enter special modes such as "low-power", "shipping" or "deep
> > +		sleep". In these modes the switch is usually off and the
> > +		quiescent current quite low.
> > +
> > +		Access: Read, Write
> > +
> > +		Valid values:
> > +
> > +		============= ==================================
> > +		"On"      (1) Power is connected to the load.
> > +		"Off"     (2) Power is disconnected to the load.
> > +		"Standby" (3) Low-power mode.
> > +		"Ship"    (4) Ship mode.
> > +		============= ==================================
> 
> `"Unknown" (0)` needs to be added here as well...

I see the issue, that userspace has no idea, which values are
supported by a specific device. I think it's better to follow
the same style, that is already used for e.g. charge_types, so
that the file reads something like this:

[On] Standby Ship

E.g. provide all supported values for the specific device and
mark the current value with square brackets.

P.S.: I've applied the unrelated cleanup patches from this series.

Greetings,

-- Sebastian

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