Disclosed herein is a method of operating a touch screen controller in a device with a touch screen having force lines and sense lines. The method includes receiving touch data from the touch screen, and operating the touch screen in a self capacitance sensing mode. In the self capacitance sensing mode, which force lines have strength values indicating a potential touch to the touch screen are determined. The method also includes operating the touch screen in a mutual capacitance sensing mode, and in the mutual capacitance sensing mode, performing mutual capacitance sensing on only a subset of the force lines, with the subset of the force lines including at least those force lines indicating the potential touch to the touch screen.