xref: /freebsd/sys/contrib/device-tree/Bindings/input/touchscreen/resistive-adc-touch.txt (revision 82ea1a07b4894bea20c61afbf702cc46f0711ead)
1c66ec88fSEmmanuel VadotGeneric resistive touchscreen ADC
2c66ec88fSEmmanuel Vadot
3c66ec88fSEmmanuel VadotRequired properties:
4c66ec88fSEmmanuel Vadot
5c66ec88fSEmmanuel Vadot - compatible: must be "resistive-adc-touch"
6c66ec88fSEmmanuel VadotThe device must be connected to an ADC device that provides channels for
7c66ec88fSEmmanuel Vadotposition measurement and optional pressure.
8*82ea1a07SEmmanuel VadotRefer to
9*82ea1a07SEmmanuel Vadothttps://github.com/devicetree-org/dt-schema/blob/master/schemas/iio/iio-consumer.yaml
10*82ea1a07SEmmanuel Vadotfor details
11*82ea1a07SEmmanuel Vadot
12c66ec88fSEmmanuel Vadot - iio-channels: must have at least two channels connected to an ADC device.
13c66ec88fSEmmanuel VadotThese should correspond to the channels exposed by the ADC device and should
14c66ec88fSEmmanuel Vadothave the right index as the ADC device registers them. These channels
15c66ec88fSEmmanuel Vadotrepresent the relative position on the "x" and "y" axes.
16c66ec88fSEmmanuel Vadot - iio-channel-names: must have all the channels' names. Mandatory channels
17c66ec88fSEmmanuel Vadotare "x" and "y".
18c66ec88fSEmmanuel Vadot
19c66ec88fSEmmanuel VadotOptional properties:
20c66ec88fSEmmanuel Vadot - iio-channels: The third channel named "pressure" is optional and can be
21c66ec88fSEmmanuel Vadotused if the ADC device also measures pressure besides position.
22c66ec88fSEmmanuel VadotIf this channel is missing, pressure will be ignored and the touchscreen
23c66ec88fSEmmanuel Vadotwill only report position.
24c66ec88fSEmmanuel Vadot - iio-channel-names: optional channel named "pressure".
25c66ec88fSEmmanuel Vadot
26c66ec88fSEmmanuel VadotExample:
27c66ec88fSEmmanuel Vadot
28c66ec88fSEmmanuel Vadot	resistive_touch: resistive_touch {
29c66ec88fSEmmanuel Vadot		compatible = "resistive-adc-touch";
30c66ec88fSEmmanuel Vadot		touchscreen-min-pressure = <50000>;
31c66ec88fSEmmanuel Vadot		io-channels = <&adc 24>, <&adc 25>, <&adc 26>;
32c66ec88fSEmmanuel Vadot		io-channel-names = "x", "y", "pressure";
33c66ec88fSEmmanuel Vadot	};
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