-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Somebody in the thread at some point said: > Hi Andy! > > Am Di 11. März 2008 schrieb Andy Green: >> - gpg control packet >> Somebody in the thread at some point said: >>> Andy >>> >>>> Currently the pump that provides 5V for the external device is enabled >>>> whenever we are in host mode. I don't know what that thing will do if >>>> we provide 5V externally too, probably it will be okay but it needs > testing. >>> You wrote "currently". Does that mean with a software change we might >>> turn off the pump and reenable charging while in host mode? >> The situation is that there is only one bit that controls if we are >> physically in host mode (this bit comes out of a PMU GPIO and can be >> controlled by the CPU). > > This bit not only controls the power pump and pulldown, but also the U4905 > RT9711BPB power switch for _inbound_ power supply. So for the given > hw-design, there's no way to have > the GTA02 powered from outside (this is the point!) > while in hw-hostmode.
WAH missed U4905, you are quite right Joerg :-( >> it won't "see" the insertion. I guess you could add 15K pulldowns >> permanently if you knew you would only use it in externally-powered-host >> mode but it is a bit sucky. > > Well, i understand you suggest to detect insertion of usb-device and high > speed mode while pulldown on, and then (triggered by some user interaction - > for we just can't detect the power reverse feed, that is if pump won't smoke) > switch EN_USBHOST GPIO to disable pump (and pulldown) and enable > charging/powering the GTA02 via RT9711BPB & PMU, while still keeping logical > hostmode for the interface. > Right? No, I was just noting you could put the CPU peripheral logic into host mode but leave the EN_USBHOST signal low. Then you could add 15K pulldowns as a hack, and it would all work. But it is a bit of a mess and would then only work in this externally powered host mode. > Anyway not having external power at all while in logical hostmode seems to be > a nogo. This has to be solved somehow. Too late I think :-/ > BTW: all this might be a lot easier with a simple coax type power connector > for feeding PMU *external_charger* path by a simple classic nokia style wall Wah dude it is great hearing from you :-) You're catching my errors and you read the datasheet :-))) That's right the PMU "adapter" path is unused. >> So we must do the test to find out where we are. > > I'm sure the pump won't care, but that's not the point. Yeah the pump didn't care. But your observation about U4905 explains why HDQ reported no charging with EN_USBHOST asserted... it wasn't because the battery suddenly became full :-(( - -Andy -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.7 (GNU/Linux) Comment: Using GnuPG with Fedora - http://enigmail.mozdev.org iD8DBQFH1vJ9OjLpvpq7dMoRAk8xAJ9zaXZjwyPSqYipa+6JBqI50bLrRACgk7fT 6vtKy8kgigtn+0qDzY4Y1zA= =ovvQ -----END PGP SIGNATURE----- _______________________________________________ OpenMoko community mailing list [email protected] http://lists.openmoko.org/mailman/listinfo/community
