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Posts: 992 | Thanked: 995 times | Joined on Dec 2009 @ California
#777
Originally Posted by javispedro View Post
But save for maybe id or vbus monitoring (not pumping since we can't use it) there's no other use for twl3040 in our current use case. Basically, twl3040 should be out of the picture, and we'd need only accesses either SoC registers (via mapped i/o) or isp1707 registers (via ulpi, either using Nokia's musb_ulpi accesor functions or manually writing the SoC registers).
OK, I just looked into ways to switch USB subsystem to HOST mode. And I tried to powerup USB stick a little. Looks successful, because N900 USB subsystem feels USB stick attachment.

The real decision about TWL4030 VBUS can be done with multimeter (poisoned to by another USB-USB connector and disassemble it to measure).

Also more importantly and along the lines of what you noticed is that you cannot get to the isp1707 while it is in standby (/lowpower protocol) or entirely shut down.
Actually, I spoke about TWL4030. It has a protection scheme in addition to poweroff/standby difficulties of accessing registers. Not yet sure - does it cover VBUS control...
 

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