[beagleboard] Trouble using UH1


I have a Beagleboard-like platform, except that I'm using a USB3320C
PHY on USBHS1 instead. Well, I'm TRYING to do that--- and having no
success so far.

According to the schematics, my wiring is otherwise identical to
Beagleboard's. Is there a reason why Beagleboard doesn't use USBHS1?

Actually, I just noticed one other difference: my VBUS signal is
floating, where Beagleboard's is connected. If that would make any
difference, then is it possible to communicate with the PHY registers
from within the uhci-omap driver? I have tried to read back the
vendor ID, etc. with no success so far.

Any suggestions welcome!


We found port 1 to be unreliable and we switched to port 2. This was before we found the real issue that pertained to noise on the 1.8V supply of the USB3320. Most could have a poorly designed board that does not take into account the noise susceptibility on the USB3320, but I don’t really have a way of knowing for sure. There are other issues that could be the problem, such as poor PCB layout, unmatched trace lengths, impedence issues, etc. You also need to look at the control of the RESET line to the board and bring it out of reset when you are ready to talk to it, not right after power up. Is the ID pin grounded? I could go on and on.