wait for power, 1st try (was Re: GTA02 u-boot and kernel status)
matt_hsu
matt_hsu at openmoko.org
Mon Mar 10 08:57:27 CET 2008
於 一,2008-03-10 於 03:24 -0300,Werner Almesberger 提到:
> matt_hsu wrote:
> > Attached file is the patch for initial power setting. Basically, it's
> > necessary to check the following conditions are satisfied with boot up.
>
> Thanks a lot ! I picked this up and rearranged some of the logic.
> I didn't use the battery voltage check yet (but see below). My
> current experimental version is here:
OK. I will take a look on it. Please let me know what else I can help
on this.
>
> Another thing I noticed is that I actually can't get the system to
> power up without a high enough battery voltage. Not sure if this for
> real or just an artefact of my test setup. Time for some more
> PCF50633 manual reading.
>
> Matt, is this why you implemented that battery voltage threshold ?
>
Yes. Since the capacity of battery is poor when system voltage is below
than 3v6 (thanks Candy's experiment ) ;-).
Cheers,
Matt
> What also needs looking into is why we actually charge in the first
> ~1200ms. The PCF50633-04 comes with a USB current limit of 500mA
> pre-configured, which we only reduce to 100mA in board_late_init,
> so drawing more than 100mA is expected (but undesired) behaviour at
> this point.
>
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