* Generic 8-bits shift register GPIO driver Required properties: - compatible: Should contain one of the following: "fairchild,74hc595" "nxp,74lvc594" - reg : chip select number - gpio-controller : Marks the device node as a gpio controller. - #gpio-cells : Should be two. The first cell is the pin number and the second cell is used to specify the gpio polarity: 0 = active high 1 = active low - registers-number: Number of daisy-chained shift registers Example: gpio5: gpio5@0 { compatible = "fairchild,74hc595"; reg = <0>; gpio-controller; #gpio-cells = <2>; registers-number = <4>; spi-max-frequency = <100000>; };