Jolla phone: Different usb power states

jolla-usb-power-states.sh

# NOTE: In order to change state, you need to run all three commands for the wanted state
#       in given order to get the desired effect

# Charge battery, and use usb power to power phone (default state after powering up the phone)
chmod u+w /sys/class/power_supply/usb/charger_disable
echo 0 > /sys/module/pm8921_charger/parameters/disabled
echo 0 > /sys/class/power_supply/usb/charger_disable

# don't charge battery, but use usb power to power phone
chmod u+w /sys/class/power_supply/usb/charger_disable
echo 1 > /sys/module/pm8921_charger/parameters/disabled
echo 0 > /sys/class/power_supply/usb/charger_disable

# don't charge battery, and don't use usb power to power phone (as if cable disconnected)
chmod u+w /sys/class/power_supply/usb/charger_disable
echo 1 > /sys/module/pm8921_charger/parameters/disabled
echo 1 > /sys/class/power_supply/usb/charger_disable

my theory how it might be logically set up in the hardware: http://xkr47.outerspace.dyndns.org/tmp/jolla-usb-power-theory3.png

It all originates from this thread: https://together.jolla.com/question/95476/how-to-prevent-charging-from-usb/