Problem: USB X6 bottom connector is not working when powering Viola Plus 1.2 through micro usb X4 connector with jumper JP2 closed.
I am powering using ‘tampered’ micro usb cable - i know, that micro usb X4 and USB X6 bottom are connected together through R56, R55. I have cut D+ and D- signals (white and green cables) in my usb cable, so only power would be connected to viola via micro usb.
When powering using X3 connector with JP2 open, then the USB X6 bottom connector is working and OS is properly enumerating USB device.
The kernel does not register a second EHCI host controller, when JP2 is closed. When JP2 is open, the kernel is registering two USB buses:
# lsusb Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
I think, jumper JP2 is switching USB0 mode from host to client. I suspect, jumper JP2 is somehow connected to pin on the Colibri VF61 - connector X1 pin number 137 / ‘USB Client Cable Detect’ / USB0_VBUS_DETECT / PTC29. The ‘USB0_VBUS_DETECT’ signal probably switches USB0 from ‘host mode’ to ‘client mode’. I think. Anyway - Is there any software way i can force the USB0 to be in ‘host mode’?
Sry my bad English. : )