[PATCH] add ac charger power_supply

Balaji Rao balajirrao at openmoko.org
Tue Dec 2 12:52:47 CET 2008

On Tue, Dec 02, 2008 at 06:01:39PM +0700, Sean McNeil wrote:
> Balaji Rao wrote:
>> On Tue, Dec 02, 2008 at 09:32:51AM +0000, Andy Green wrote:
>>> Hash: SHA1
>>> Somebody in the thread at some point said:
>>> | This adds an appropriate ac power_supply class and shows usb only when
>>> | at the appropriate current limit.
>>> What do you think Balaji?  At first it seemed to me that adding another
>>> power_supply is broken for generic pcf50633 case, but actually, if it is
>>> cleared for 1A on USB for example then there is definitely an AC adapter
>>> involved.  Is this OK for you?
>> I strongly feel it's wrong to pollute the driver with application
>> specific stuff.
>> Sean, why can't we use the PROP_CURRENT_AVG to decide on whether the usb
>> is connected to a host or an adapter ? Adding that field should be
>> trivial and preserves the generic nature of the driver. What do you
>> think ?
> I can live with or without the ac power_supply. I was of the opinion it  
> might be nice to know the difference between having USB power or AC.   
> Sounds like providing the current would be sufficient. But is it legal  
> for USB current to be 1A? Android will happily fail to find ac and  
> continue on without a problem, but it does look for an ac power_supply.

Make sense.

Can we always call a 500 mA power supply as 'usb' ? Some other
application might choose to draw only 500mA from a wall charger ?

Anyway, the chip allows for a usb current limit of 1A. So I think it
makes sense to call it 'usb' no matter what the current limit is.

- Balaji

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