| * 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"; |
| }; |
| }; |