Messages in this thread | ![/](/images/icornerl.gif) | | Date | Thu, 27 Jul 2006 16:59:44 +0200 | From | Pavel Machek <> | Subject | Re: Generic battery interface |
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Hi!
> >This would also be useful for the OLPC project - it's unlikely that > >it'll use ACPI, but a more feature-rich interface than /proc/apm would > >be massively helpful. This is just a matter of speccing out what > >information is needed and what format it should be presented in, and > >then adding a new device class, right? > > Can we really assume there's one driver providing all battery-related > attributes?
Anything else would be crazy, I'd say.
> For example, on a ThinkPad you want the ACPI battery module loaded so > that handles hande battery-related ACPI events, but on ACPI can't > doesn't provide all available attributes. For example, ACPI reports > the equvialent of > /sys/devices/platform/smapi/BAT0/power_avg (last minute average) > but not > /sys/devices/platform/smapi/BAT0/power_now (instantaneous average) > or > /sys/devices/platform/smapi/BAT0/cycle_count > or control functions like > /sys/devices/platform/smapi/BAT0/force_discharge > (see http://thinkwiki.org/wiki/tp_smapi for detials).
Well, in that case probably smapi driver should "hook into" acpi driver.
> In this particular case we could split the ACPI module into two, one > module for events and one module for the sysfs interface, and load > only the first one on ThinkPads. But that's only because tp_smapi > happens to reproduce all of ACPI's attributes; there are probably > other cases whether neither method dominates the other.
I hope such hardware will not be too common. Thinkpad is covered by accident, and I do not know about any other problematic machine.
Worst case, we would get equivalent of
/sys/class/battery/system_battery_acpi/... /sys/class/battery/system_battery_some_clever_vendor_hack/...
with some values common between both of them. I'd say it is still better than having vendor_hack in /sys in one format while having acpi battery in /proc/acpi in completely different format. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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