1* Single Byte SPI LED Device Driver. 2 3The driver can be used for controllers with a very simple SPI protocol: 4- one LED is controlled by a single byte on MOSI 5- the value of the byte gives the brightness between two values (lowest to 6 highest) 7- no return value is necessary (no MISO signal) 8 9The value for lowest and highest brightness is dependent on the device and 10therefore on the compatible string. 11 12Depending on the compatible string some special functions (like hardware 13accelerated blinking) might can be supported too. 14 15The driver currently only supports one LED. The properties of the LED are 16configured in a sub-node in the device node. 17 18Required properties: 19- compatible: should be one of 20 * "ubnt,acb-spi-led" microcontroller (SONiX 8F26E611LA) based device 21 used for example in Ubiquiti airCube ISP 22 23Property rules described in Documentation/devicetree/bindings/spi/spi-bus.txt 24apply. 25 26LED sub-node properties: 27- label: 28 see Documentation/devicetree/bindings/leds/common.txt 29- default-state: 30 see Documentation/devicetree/bindings/leds/common.txt 31 Only "on" and "off" are supported. 32 33Example: 34 35led-controller@0 { 36 compatible = "ubnt,acb-spi-led"; 37 reg = <0>; 38 spi-max-frequency = <100000>; 39 40 led { 41 label = "white:status"; 42 default-state = "on"; 43 }; 44}; 45