Kernel-3.10.0-957.el7_gpio-74x164

• Generic 8-bits shift register GPIO driver

Required properties:

• compatible : Should be “fairchild,74hc595”
• 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>;
};