[PATCH 8/9] add-gta03-pmu-533MHz-init.patch

Werner Almesberger werner at openmoko.org
Wed Aug 20 16:56:23 CEST 2008

Andy Green wrote:
> My ammeter shows ~120mA average during Linux boot from USB, this is at
> 400MHz though (with backlight down).

400MHz (instead of 200MHz) adds some 30mA. If you have LDO6 (LCM) on
and have taken Glamo out of reset, that should be roughly another
20-30mA. (I never measured what LDO6 alone draws. Glamo draws 15mA
and LDO1, 2, 5, and 6 together burn 40mA.)

All the numbers are in this thread:

So it seems our measurements agree.

> This does matter because now we won't enable charging until we get into
> Linux, if the battery is stone cold dead we really need to be able to
> get as far as pcf50633 init and USB enumeration so we can come back from
> the dead on GTA03 (regardless of VB_SYS situation).


> Anyway it's not Qi issue for today but it is shaping up clearly as
> kernel issue for "tomorrow", I wonder if it means we should examine
> Cesar's cpufreq stuff carefully as it can be a big part of the answer.

At least the part that's tweaking the core clock. We still have to
be careful not to bring up any new peripherals or enable other rails
before we know that power is good.

(I can imagine someone now suggesting to put them all into modules and
only have ADC and USB in the monolithic part of the kernel ;-)

- Werner

More information about the openmoko-kernel mailing list