mirror of
https://github.com/torvalds/linux.git
synced 2024-12-19 01:23:20 +00:00
3a341a4c30
Some encoders have both outputs low in stable states, others also have a stable state with both outputs high (half-period mode) and some have a stable state in all steps (quarter-period mode). The driver used to support the former states and with this change it can also support the later. This commit also deprecates the 'half-period' property and introduces a new property 'steps-per-period'. This property specifies the number of steps (stable states) produced by the rotary encoder for each GPIO period. Signed-off-by: Guido Martínez <guido@vanguardiasur.com.ar> Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
47 lines
1.6 KiB
Plaintext
47 lines
1.6 KiB
Plaintext
Rotary encoder DT bindings
|
|
|
|
Required properties:
|
|
- gpios: a spec for two GPIOs to be used
|
|
|
|
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 rollove 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.
|
|
|
|
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/rotary-encoder.txt 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,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,rollover;
|
|
};
|