- 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
Optional properties:
- enable-gpios: GPIO connected to the OE (Output Enable) pin.
Example:
gpio5: gpio5@0 {
compatible = “fairchild,74hc595”;
reg = <0>;
gpio-controller;
#gpio-cells = <2>;
registers-number = <4>;
spi-max-frequency = <100000>;
};