espressif,esp32-touch

Vendor: Espressif Systems

Note

An implementation of a driver matching this compatible is available in drivers/input/input_esp32_touch_sensor.c.

Description

Zephyr input touch sensor parent node

This defines a group of touch sensors that can generate input events. Each touch
sensor is defined in a child node of the touch-sensor node and defines a specific key
code.

For example:

#include <zephyr/dt-bindings/input/input-event-codes.h>
#include <zephyr/dt-bindings/input/esp32-touch-sensor-input.h>

&touch {
       compatible = "espressif,esp32-touch";
       status = "okay";

       debounce-interval-ms = <30>;
       href-microvolt = <27000000>;
       lref-microvolt = <500000>;
       href-atten-microvolt = <1000000>;
       filter-mode = <ESP32_TOUCH_FILTER_MODE_IIR_16>;
       filter-debounce-cnt = <1>;
       filter-noise-thr = <ESP32_TOUCH_FILTER_NOISE_THR_4_8TH>;
       filter-jitter-step = <4>;
       filter-smooth-level = <ESP32_TOUCH_FILTER_SMOOTH_MODE_IIR_2>;

       touch_sensor_0 {
               channel-num = <1>;
               channel-sens = <20>;
               zephyr,code = <INPUT_KEY_0>;
       };
};

Properties

Top level properties

These property descriptions apply to “espressif,esp32-touch” nodes themselves. This page also describes child node properties in the following sections.

Node specific properties

Properties not inherited from the base binding file.

Name

Type

Details

debounce-interval-ms

int

 
Debouncing interval time in milliseconds.

Default value: 30

href-microvolt

int

 
Touch sensor high reference voltage.

Default value: 2700000

Legal values: 2400000, 2500000, 2500000, 2700000

lref-microvolt

int

 
Touch sensor low reference voltage.

Default value: 500000

Legal values: 500000, 600000, 700000, 800000

href-atten-microvolt

int

 
Touch sensor high reference attenuation voltage.

Default value: 1000000

Legal values: 1500000, 1000000, 500000, 0

filter-mode

int

 
Touch sensor IIR filter coefficient.
If not specified defaults to ESP32_TOUCH_FILTER_MODE_IIR_16.

Default value: 2

filter-debounce-cnt

int

 
Touch sensor debounce count.
If not specified defaults to 1.

Default value: 1

filter-noise-thr

int

 
Touch sensor noise threshold coefficient.
If not specified defaults to ESP32_TOUCH_FILTER_NOISE_THR_4_8TH.

filter-jitter-step

int

 
Touch sensor jitter filter step size.
If not specified defaults to 4.

Default value: 4

filter-smooth-level

int

 
Touch sensor level of filter applied on the original data against large noise interference.
If not specified defaults to ESP32_TOUCH_FILTER_SMOOTH_MODE_IIR_2.

Default value: 1

Deprecated node specific properties

Deprecated properties not inherited from the base binding file.

(None)

Base properties

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 “espressif,esp32-touch” compatible.

Name

Type

Details

status

string

 
indicates the operational status of a device

Legal values: 'ok', 'okay', 'disabled', 'reserved', 'fail', 'fail-sss'

See Important properties for more information.

compatible

string-array

 
compatible strings

This property is required.

See Important properties for more information.

reg

array

 
register space

See Important properties for more information.

reg-names

string-array

 
name of each register space

interrupts

array

 
interrupts for device

See Important properties for more information.

interrupts-extended

compound

 
extended interrupt specifier for device

interrupt-names

string-array

 
name of each interrupt

interrupt-parent

phandle

 
phandle to interrupt controller node

label

string

 
Human readable string describing the device (used as device_get_binding() argument)

See Important properties for more information.

This property is deprecated.

clocks

phandle-array

 
Clock gate information

clock-names

string-array

 
name of each clock

#address-cells

int

 
number of address cells in reg property

#size-cells

int

 
number of size cells in reg property

dmas

phandle-array

 
DMA channels specifiers

dma-names

string-array

 
Provided names of DMA channel specifiers

io-channels

phandle-array

 
IO channels specifiers

io-channel-names

string-array

 
Provided names of IO channel specifiers

mboxes

phandle-array

 
mailbox / IPM channels specifiers

mbox-names

string-array

 
Provided names of mailbox / IPM channel specifiers

power-domains

phandle-array

 
Power domain specifiers

power-domain-names

string-array

 
Provided names of power domain specifiers

#power-domain-cells

int

 
Number of cells in power-domains property

zephyr,deferred-init

boolean

 
Do not initialize device automatically on boot. Device should be manually
initialized using device_init().

wakeup-source

boolean

 
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.

zephyr,pm-device-runtime-auto

boolean

 
Automatically configure the device for runtime power management after the
init function runs.

zephyr,disabling-power-states

phandles

 
List of power states that will disable this device power.

Child node properties

Name

Type

Details

channel-num

int

 
Touch sensor channel number

This property is required.

channel-sens

int

 
Touch sensor channel sensibility in 100th.
If not specified defaults to 20.

Default value: 20

zephyr,code

int

 
Key code to emit.

This property is required.