0001 Generic Parallel-in/Serial-out Shift Register GPIO Driver
0002
0003 This binding describes generic parallel-in/serial-out shift register
0004 devices that can be used for GPI (General Purpose Input). This includes
0005 SN74165 serial-out shift registers and the SN65HVS88x series of
0006 industrial serializers.
0007
0008 Required properties:
0009 - compatible : Should be "pisosr-gpio".
0010 - gpio-controller : Marks the device node as a GPIO controller.
0011 - #gpio-cells : Should be two. For consumer use see gpio.txt.
0012
0013 Optional properties:
0014 - ngpios : Number of used GPIO lines (0..n-1), default is 8.
0015 - load-gpios : GPIO pin specifier attached to load enable, this
0016 pin is pulsed before reading from the device to
0017 load input pin values into the device.
0018
0019 For other required and optional properties of SPI slave
0020 nodes please refer to ../spi/spi-bus.txt.
0021
0022 Example:
0023
0024 gpio@0 {
0025 compatible = "ti,sn65hvs882", "pisosr-gpio";
0026 gpio-controller;
0027 #gpio-cells = <2>;
0028
0029 load-gpios = <&gpio2 23 GPIO_ACTIVE_LOW>;
0030
0031 reg = <0>;
0032 spi-max-frequency = <1000000>;
0033 spi-cpol;
0034 };
