Setting / checking fast charge in /sys/devices/platform/whatever

AVee openmoko-comunity at
Fri Jul 25 23:04:20 CEST 2008

On Monday 14 July 2008 21:44, Stroller wrote:
> I decided to try forcing the Freerunner to fast-charge, and a little
> Googling found me the CheckFastCharge-script on the Wiki [3].
> Reading I find that it checks '/sys/devices/
> platform/s3c2410-i2c/i2c-adapter/i2c-0/0-0008/chgmode' and that fast
> charging is indicated by "fast_cccv" there.
> Presumably this script was written for the Neo1973, however, or a
> different kernel, as on my Freerunner the location is '/sys/devices/
> platform/s3c2440-i2c/i2c-adapter/i2c-0/0-0073/chgmode' and it
> currently says "fast", not "fast_cccv" (or, for that matter, slow or
> anything like that).
> So is "fast" the correct syntax for the Freerunner's chgmode?
> Has it somehow detected that the charger is capable of 500+ mA?
> Or should I echo "fast_cccv" to that location?
> What are the correct '/sys/devices/platform/s3c2440-i2c/i2c-adapter/
> i2c-0/0-0073/chgmode' values for "slow" and no-charge for the
> Freerunner, please? (using the default factory image)
> Or is chgmode simply broken on the Freerunner's default factory image?

Did you actually try this yet, and did it work? I just bought a car-charges 
which is supossed to be able to provide over 2A, but the freerunner will only 
pull 100mA which is annoying.

A related question, the freerunner wil detect a 47k resitor in the official 
charger. Is this value measured and available in software somewere? We might 
be able to identify other chargers as well and build a database of ID 
resistors and allowed current (assuming other vendors use the same trick).


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