kernel/Documentation/ABI/testing/sysfs-platform-twl4030-usb

   1 What: /sys/bus/platform/devices/*twl4030-usb/vbus
   2 Description:
   3         Read-only status reporting if VBUS (approx 5V)
   4         is being supplied by the USB bus.
   5
   6         Possible values: "on", "off".
   7
   8         Changes are notified via select/poll.