Re: power_supply class/framework question

[Anton Vorontsov <avorontsov@ru.mvista.com>]

On Mon, Aug 10, 2009 at 05:00:11PM +0200, Pavel Machek wrote:
> Hi!
> 
> > (feel free to redirect me to a different mailing list if there's a
> > more appropriate place to ask this question)
> > 
> > I'm working on cleaning up some code to more correctly use the power
> > supply framework (have the battery driver receive notification from
> > the wall/usb power supplies, etc), and ran into a slight snag.  For
> > mobile usb powered devices, we need to know how much current can
> > safely be consumed by the charge circuit -- generally this is one of:
> > none, <500mA or 1000mA, which correspond to "no power supply", "usb
> > power supply", or "wall power supply".
> 
> Actuallly, it is one of 'none', 100mA (min power USB has to supplly),
> 500mA (max powe USB can supply by spec), 1A (wall).
> 
> For example sharp zaurus can only supply cca 300mA out of its port.
> 
> > I can use power_supply_am_i_supplied() to determine if I'm receiving
> > power, but there's no way to determine either how much (if I have one
> > power supply that indicates max current available) or which supply (if
> > I define a separate "ac" and "usb" power supply).
> 
> Should am_i_supplied() just return miliamps?

Or enum power_supply_type, with the following priority:
mains (wall), usb, battery?

-- 
Anton Vorontsov
email: cbouatmailru@gmail.com
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