Use Touchpad only for scrolling in GNU/Linux

xinput --set-prop 'SynPS/2 Synaptics TouchPad'  'Synaptics Edge Scrolling' 1 1 0

xinput --set-prop 'SynPS/2 Synaptics TouchPad'  'Synaptics Edge Scrolling' 1 1 0

xinput --set-prop 'SynPS/2 Synaptics TouchPad'  'Synaptics Scrolling Distance' 250 

From : http://unix.stackexchange.com/questions/52339/can-i-configure-my-laptops-touchpad-to-only-do-scrolling