Messages in this thread | | | Subject | Re: [RFC] [PATCH] Make ACPI button driver an input device | From | Richard Purdie <> | Date | Mon, 24 Apr 2006 21:59:31 +0100 |
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On Mon, 2006-04-24 at 22:34 +0200, Pavel Machek wrote: > What is on the jack, BTW? Left headphone, right headphone, mic in? Can > all of them be used independently?
> > It gets tricky. AC presence isn't a property of a battery for example > > and is in fact more like a switch (my handheld has a mechanical > > switch > > Oops, really? Mechanical switch to sense ac in? (What happens when you > plug in charger but that is not plugged to AC?)
Most of the Zaurus devices can measure the AC voltage and make sanity checks on it in the SharpSL Battery/PM code.
> I think that AC presence should be handled independently from > battery. There can be >1 battery in the system.
Agreed. This is some of the leftover information I'm referring to below.
>(Another interesting question is: is AC status 0/1 or is it number of > milivolts?)
I'd say millivolts except for the problem of what you do on systems that don't support voltage readings. Use a very high value I guess. For a lot of devices millivolts also means in kernel conversion tables. Do such things belong in kernel or user space?
> > to detect when its plugged in) ;). The battery class would export some > > information but not all of it and I don't know where the leftover > > information should go. If I knew that, I'd write the class. > > Leftover information?
Where to put AC status and AC voltage readings amongst other things. Another sysfs class? Also, how do you control suspend/resume notifications to userspace if not using APM/ACPI?
> I think we should create directory in sysfs, and populate it according > to battery's capabilities. > > Zaurus' battery would have voltage and maybe percent fields. > > ACPI battery would have all the usual fields. > > Another important question is a way for user applications to avoid > polling... but I guess that should be solveable by enabling select on > one of those files.
Agreed, this is something that would be needed.
Richard
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