79 строки
2.3 KiB
Plaintext
79 строки
2.3 KiB
Plaintext
Microchip AT42QT1050 Five-channel Touch Sensor IC
|
|
|
|
The AT42QT1050 (QT1050) is a QTouchADC sensor device. The device can sense from
|
|
one to five keys, dependent on mode. The QT1050 includes all signal processing
|
|
functions necessary to provide stable sensing under a wide variety of changing
|
|
conditions, and the outputs are fully debounced.
|
|
|
|
The touchkey device node should be placed inside an I2C bus node.
|
|
|
|
Required properties:
|
|
- compatible: Must be "microchip,qt1050"
|
|
- reg: The I2C address of the device
|
|
- interrupts: The sink for the touchpad's IRQ output,
|
|
see ../interrupt-controller/interrupts.txt
|
|
|
|
Optional properties:
|
|
- wakeup-source: touch keys can be used as a wakeup source
|
|
|
|
Each button (key) is represented as a sub-node:
|
|
|
|
Each not specified key or key with linux,code set to KEY_RESERVED gets disabled
|
|
in HW.
|
|
|
|
Subnode properties:
|
|
- linux,code: Keycode to emit.
|
|
- reg: The key number. Valid values: 0, 1, 2, 3, 4.
|
|
|
|
Optional subnode-properties:
|
|
|
|
If a optional property is missing or has a invalid value the default value is
|
|
taken.
|
|
|
|
- microchip,pre-charge-time-ns:
|
|
Each touchpad need some time to precharge. The value depends on the mechanical
|
|
layout.
|
|
Valid value range: 0 - 637500; values must be a multiple of 2500;
|
|
default is 0.
|
|
- microchip,average-samples:
|
|
Number of data samples which are averaged for each read.
|
|
Valid values: 1, 4, 16, 64, 256, 1024, 4096, 16384; default is 1.
|
|
- microchip,average-scaling:
|
|
The scaling factor which is used to scale the average-samples.
|
|
Valid values: 1, 2, 4, 8, 16, 32, 64, 128; default is 1.
|
|
- microchip,threshold:
|
|
Number of counts to register a touch detection.
|
|
Valid value range: 0 - 255; default is 20.
|
|
|
|
Example:
|
|
QT1050 with 3 non continuous keys, key2 and key4 are disabled.
|
|
|
|
touchkeys@41 {
|
|
compatible = "microchip,qt1050";
|
|
reg = <0x41>;
|
|
interrupt-parent = <&gpio0>;
|
|
interrupts = <17 IRQ_TYPE_EDGE_FALLING>;
|
|
|
|
up@0 {
|
|
reg = <0>;
|
|
linux,code = <KEY_UP>;
|
|
microchip,average-samples = <64>;
|
|
microchip,average-scaling = <16>;
|
|
microchip,pre-charge-time-ns = <10000>;
|
|
};
|
|
|
|
right@1 {
|
|
reg = <1>;
|
|
linux,code = <KEY_RIGHT>;
|
|
microchip,average-samples = <64>;
|
|
microchip,average-scaling = <8>;
|
|
};
|
|
|
|
down@3 {
|
|
reg = <3>;
|
|
linux,code = <KEY_DOWN>;
|
|
microchip,average-samples = <256>;
|
|
microchip,average-scaling = <16>;
|
|
};
|
|
};
|