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