AnsweredAssumed Answered

Disable USB VBUS power supply

Question asked by Engin Lee on Jan 18, 2019
Latest reply on Mar 14, 2019 by Engin Lee



I am trying to power off USB port on my i.MX6ULL with 4.14.78 BSP and there is an instruction on the reference manual:

4.9.8 How to Close the USB Child Device Power
The following code string outlines how to close the USB child device power:
echo auto > /sys/bus/usb/devices/1-1/power/control
echo auto > /sys/bus/usb/devices/1-1.1/power/control (If there is a hub at USB device)

But it seems not working like that:

echo auto > /sys/bus/usb/devices/1-1/power/control   // -> nothing happened

echo auto > /sys/bus/usb/devices/usb1/power/control   // -> device detached, but VBUS 5V is still ON

Even if I enter deep sleep mode (echo mem > /sys/power/state), VBUS 5V  is still ON.

Is there any setting or configuration to change this behavior? I don't want to get USB devices to be charged from USB port after entering deep sleep mode.