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Diffstat (limited to 'Documentation/devicetree/bindings/input/rotary-encoder.txt')
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diff --git a/Documentation/devicetree/bindings/input/rotary-encoder.txt b/Documentation/devicetree/bindings/input/rotary-encoder.txt new file mode 100644 index 000000000..a644408b3 --- /dev/null +++ b/Documentation/devicetree/bindings/input/rotary-encoder.txt @@ -0,0 +1,50 @@ +Rotary encoder DT bindings + +Required properties: +- gpios: a spec for at least two GPIOs to be used, most significant first + +Optional properties: +- linux,axis: the input subsystem axis to map to this rotary encoder. + Defaults to 0 (ABS_X / REL_X) +- rotary-encoder,steps: Number of steps in a full turnaround of the + encoder. Only relevant for absolute axis. Defaults to 24 which is a + typical value for such devices. +- rotary-encoder,relative-axis: register a relative axis rather than an + absolute one. Relative axis will only generate +1/-1 events on the input + device, hence no steps need to be passed. +- rotary-encoder,rollover: Automatic rollover when the rotary value becomes + greater than the specified steps or smaller than 0. For absolute axis only. +- rotary-encoder,steps-per-period: Number of steps (stable states) per period. + The values have the following meaning: + 1: Full-period mode (default) + 2: Half-period mode + 4: Quarter-period mode +- wakeup-source: Boolean, rotary encoder can wake up the system. +- rotary-encoder,encoding: String, the method used to encode steps. + Supported are "gray" (the default and more common) and "binary". + +Deprecated properties: +- rotary-encoder,half-period: Makes the driver work on half-period mode. + This property is deprecated. Instead, a 'steps-per-period ' value should + be used, such as "rotary-encoder,steps-per-period = <2>". + +See Documentation/input/devices/rotary-encoder.rst for more information. + +Example: + + rotary@0 { + compatible = "rotary-encoder"; + gpios = <&gpio 19 1>, <&gpio 20 0>; /* GPIO19 is inverted */ + linux,axis = <0>; /* REL_X */ + rotary-encoder,encoding = "gray"; + rotary-encoder,relative-axis; + }; + + rotary@1 { + compatible = "rotary-encoder"; + gpios = <&gpio 21 0>, <&gpio 22 0>; + linux,axis = <1>; /* ABS_Y */ + rotary-encoder,steps = <24>; + rotary-encoder,encoding = "binary"; + rotary-encoder,rollover; + }; |