1Generic Parallel-in/Serial-out Shift Register GPIO Driver 2 3This binding describes generic parallel-in/serial-out shift register 4devices that can be used for GPI (General Purpose Input). This includes 5SN74165 serial-out shift registers and the SN65HVS88x series of 6industrial serializers. 7 8Required properties: 9 - compatible : Should be "pisosr-gpio". 10 - gpio-controller : Marks the device node as a GPIO controller. 11 - #gpio-cells : Should be two. For consumer use see gpio.txt. 12 13Optional properties: 14 - ngpios : Number of used GPIO lines (0..n-1), default is 8. 15 - load-gpios : GPIO pin specifier attached to load enable, this 16 pin is pulsed before reading from the device to 17 load input pin values into the device. 18 19For other required and optional properties of SPI slave 20nodes please refer to ../spi/spi-bus.txt. 21 22Example: 23 24 gpio@0 { 25 compatible = "ti,sn65hvs882", "pisosr-gpio"; 26 gpio-controller; 27 #gpio-cells = <2>; 28 29 load-gpios = <&gpio2 23 GPIO_ACTIVE_LOW>; 30 31 reg = <0>; 32 spi-max-frequency = <1000000>; 33 spi-cpol; 34 }; 35