Just a quick write up on how get the touch & screen of the official Raspberry Pi display working upside down.
Edit /boot/config.txt and add the following line:
2 means rotating the screen 180°.
90° would be 1 and 270° would be 3.
It is important that there no blanks around the =-sign.
Some howtos have that wrong.
Next do a
sudo apt-get -y install xinput evtest
and add the following line to /etc/X11/Xsession
DISPLAY=:0 xinput --set-prop ‘FT5406 memory based driver’ 'Evdev Axis Inversion' 1 1
After another reboot you can use your RasPi-Display-combination with the power connectors facing up, which is quite handy when using the contraption without a dedicated stand.