My Gta02s wont charge
joerg at openmoko.org
Sun Jun 22 22:37:12 CEST 2008
Am So 22. Juni 2008 schrieb Werner Almesberger:
> Joerg Reisenweber wrote:
> > I think battery charging *never* may be turned off.
> That's my understanding so far as well. What bothers me is that I can't
> the device to show the symptoms I would expect in the various states,
> both good and bad symptoms.
> - Werner
That's when I made a comment to the effect that we probably don't care about
our battery the way we should, some time ago.
Charging of battery has to be autonomous by PCF506xx, and all we need to care
about is to ENABLE it, and to *set the right currents and voltages* for PMU's
charger (and handle errors / monitor charging state). This has to be
done/redone (as often and) as early in boot as possible, to guarantee there
never will be set a too high max voltage (would kill battery) or charging
disabled (also by any error-condition [e.g. overvoltage] which has to be
handled and reset) which would lead to the deadlock Steve faces now.
It is utterly nonsense to intentionally disable battery charging in any time
Booting from USB OTOH is mere impossible, as long as we obey the specs. We are
supposed to draw no more than 100mA from USB until CPU is up and does some
sophisticated negotiations/probes to increase the maximum allowable
USB-current set (again) in PCF506xx registers. We have to guarantee there is
100mA set whenever the CPU is down and not able to do these probes - or we
forget about the specs and won't be off much better because even then the
*host* will not forget about them (at least on win-OS as I understand it).
But we could make possible to boot from wallcharger if we don't give a s**t
on the usb-specs.
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