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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
commit76cb841cb886eef6b3bee341a2266c76578724ad (patch)
treef5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /Documentation/devicetree/bindings/input/rotary-encoder.txt
parentInitial commit. (diff)
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Adding upstream version 4.19.249.upstream/4.19.249upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
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+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;
+ };