| Generic Parallel-in/Serial-out Shift Register GPIO Driver |
| |
| This binding describes generic parallel-in/serial-out shift register |
| devices that can be used for GPI (General Purpose Input). This includes |
| SN74165 serial-out shift registers and the SN65HVS88x series of |
| industrial serializers. |
| |
| Required properties: |
| - compatible : Should be "pisosr-gpio". |
| - gpio-controller : Marks the device node as a GPIO controller. |
| - #gpio-cells : Should be two. For consumer use see gpio.txt. |
| |
| Optional properties: |
| - ngpios : Number of used GPIO lines (0..n-1), default is 8. |
| - load-gpios : GPIO pin specifier attached to load enable, this |
| pin is pulsed before reading from the device to |
| load input pin values into the device. |
| |
| For other required and optional properties of SPI slave |
| nodes please refer to ../spi/spi-bus.txt. |
| |
| Example: |
| |
| gpio@0 { |
| compatible = "ti,sn65hvs882", "pisosr-gpio"; |
| gpio-controller; |
| #gpio-cells = <2>; |
| |
| load-gpios = <&gpio2 23 GPIO_ACTIVE_LOW>; |
| |
| reg = <0>; |
| spi-max-frequency = <1000000>; |
| spi-cpol; |
| }; |