* Single Byte SPI LED Device Driver. The driver can be used for controllers with a very simple SPI protocol: - one LED is controlled by a single byte on MOSI - the value of the byte gives the brightness between two values (lowest to highest) - no return value is necessary (no MISO signal) The value for lowest and highest brightness is dependent on the device and therefore on the compatible string. Depending on the compatible string some special functions (like hardware accelerated blinking) might can be supported too. The driver currently only supports one LED. The properties of the LED are configured in a sub-node in the device node. Required properties: - compatible: should be one of * "ubnt,acb-spi-led" microcontroller (SONiX 8F26E611LA) based device used for example in Ubiquiti airCube ISP Property rules described in Documentation/devicetree/bindings/spi/spi-bus.txt apply. LED sub-node properties: - label: see Documentation/devicetree/bindings/leds/common.txt - default-state: see Documentation/devicetree/bindings/leds/common.txt Only "on" and "off" are supported. Example: led-controller@0 { compatible = "ubnt,acb-spi-led"; reg = <0>; spi-max-frequency = <100000>; led { label = "white:status"; default-state = "on"; }; };