Thread: N900 will not allow USB OTG!
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egoshin is offline egoshin
2010-05-08 , 04:17
Posts: 992 | Thanked: 995 times | Joined on Dec 2009 @ California
#788
Originally Posted by joerg_rw View Post
a) /sys/class/i2c-adapter/i2c-1/1-0048/twl4030_usb/vbus is 5V VBUS detection, probably from twl4030
3.5V - it is from my experiment, see my previous post.

b) /sys/devices/platform/musb_hdrc/charger is D+/- short detect, aka charger_detect, probably from 1707
Sure - 1707, it is from code.

c) charger_detect only works (or is triggered) when VBUS is applied
It is a pure wish of BME and we are not sure then it reads file '.../charger'

d) charger_detect is 'stricky', se 3) vs 5) above. I.E. it is reset to 0 only when vbus is removed (I have not checked to keep D+/- short while removing VBUS, but I'd expect the standard charger when unplugged from mains does exactly that, and it results in 0 0 )
charger_detect is called by reading file /sys/devices/platform/musb_hdrc/charger and it seems that BME reads it after it gets signal about VBUS UP.
 

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