adc-keys
Vendor: Generic or vendor-independent
Note
An implementation of a driver matching this compatible is available in drivers/input/input_adc_keys.c.
Description
Input driver for ADC attached resistor ladder buttons.
The driver itself does not calculate each possible combination of resistor
values. Instead, users are required to specify the voltage for each single
key press or for combinations of key presses.
Example:
#include <dt-bindings/input/input-event-codes.h>
/ {
buttons {
compatible = "adc-keys";
io-channels = <&adc 2>;
keyup-threshold-mv = <0>;
key_0 {
press-thresholds-mv = <1650>, /* KEY0 */
<2536>; /* KEY0 + KEY1 */
zephyr,code = <INPUT_KEY_0>;
};
key_1 {
press-thresholds-mv = <2300>, /* KEY1 */
<2536>; /* KEY0 + KEY1 */
zephyr,code = <INPUT_KEY_1>;
};
};
};
Properties
Top level properties
These property descriptions apply to “adc-keys” nodes themselves. This page also describes child node properties in the following sections.
Properties not inherited from the base binding file.
Name |
Type |
Details |
|---|---|---|
|
|
Sample period in milliseconds.
If not specified defaults to 20.
Default value: |
|
|
Millivolt value to which all the keys are considered up.
This property is required. |
Deprecated properties not inherited from the base binding file.
(None)
Properties inherited from the base binding file, which defines common properties that may be set on many nodes. Not all of these may apply to the “adc-keys” compatible.
Name |
Type |
Details |
|---|---|---|
|
|
Phandle to an ADC channel.
This property is required. |
|
|
indicates the operational status of a device
Legal values: See Important properties for more information. |
|
|
compatible strings
This property is required. See Important properties for more information. |
|
|
register space
See Important properties for more information. |
|
|
name of each register space
|
|
|
interrupts for device
See Important properties for more information. |
|
|
extended interrupt specifier for device
|
|
|
name of each interrupt
|
|
|
phandle to interrupt controller node
|
|
|
Human readable string describing the device (used as device_get_binding() argument)
See Important properties for more information. This property is deprecated. |
|
|
Clock gate information
|
|
|
name of each clock
|
|
|
number of address cells in reg property
|
|
|
number of size cells in reg property
|
|
|
DMA channels specifiers
|
|
|
Provided names of DMA channel specifiers
|
|
|
Provided names of IO channel specifiers
|
|
|
mailbox / IPM channels specifiers
|
|
|
Provided names of mailbox / IPM channel specifiers
|
|
|
Power domain specifiers
|
|
|
Provided names of power domain specifiers
|
|
|
Number of cells in power-domains property
|
|
|
Do not initialize device automatically on boot. Device should be manually
initialized using device_init().
|
|
|
Property to identify that a device can be used as wake up source.
When this property is provided a specific flag is set into the
device that tells the system that the device is capable of
wake up the system.
Wake up capable devices are disabled (interruptions will not wake up
the system) by default but they can be enabled at runtime if necessary.
|
|
|
Automatically configure the device for runtime power management after the
init function runs.
|
|
|
List of power states that will disable this device power.
|
Child node properties
Name |
Type |
Details |
|---|---|---|
|
|
Array of millivolt values to consider a key pressed.
This property is required. |
|
|
Key code to emit.
This property is required. |