Messages in this thread | | | Date | Mon, 10 Aug 2009 09:14:01 -0700 | Subject | Re: power_supply class/framework question | From | Brian Swetland <> |
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On Mon, Aug 10, 2009 at 8:28 AM, Anton Vorontsov<avorontsov@ru.mvista.com> wrote: > On Mon, Aug 10, 2009 at 05:00:11PM +0200, Pavel Machek wrote: >> > 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). >> >> > 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?
Either of those would work, though in the case of USB, as Pavel correctly points out, we'd need to differentiate between non-enumerated and enumerated, so perhaps max available milliamps would be best. Or USB could just not indicate that it's supplied until after enumeration is successful.
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