Messages in this thread | | | Date | Tue, 30 Jun 2009 16:57:14 +0100 | From | Mark Brown <> | Subject | Re: [PATCH 5/5] power_supply: add a charge_type status to the api, and use it for olpc driver |
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On Tue, Jun 30, 2009 at 07:37:19PM +0400, Anton Vorontsov wrote: > On Tue, Jun 30, 2009 at 11:04:30AM -0400, Andres Salomon wrote:
> > As far as the slow type, I don't see the need either, but I assumed > > Anton was aware of devices that differentiated between slow and > > trickle charging.
> Yep, there are two charging modes in Openmoko Neo FreeRunners:
> - 100 mA. It's "slow" mode -- used when the Neo couldn't negotiate > with USB host, so it is permitted to only draw 100 mA from VBUS.
I strongly suspect you will find that the "slow" mode there is actually a trickle charge. It's a lot more practical to trickle charge in mobile phone sized systems since the batteries are so much smaller than laptop batteries.
> - 500/1000 mA. It's so-called "fast" mode, can be enabled after > successful negotiation with the USB host.
Even if the 500mA is available you'll not always be able to do a fast charge from a USB supply - some systems draw enough current to require that the USB supply be suppliemented from battery when they're being heavily used.
> Well, this kind slow charging isn't official terminology, and > I'm not sure if we should use it. But I'm fine with it since we > can always remove "Slow" mode (i.e. report it as "Fast"), and > userspace won't break.
I guess my main question was if it was distinguishable from trickle charging.
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