linux-stable/Documentation/devicetree/bindings/thermal/generic-adc-thermal.yaml

85 lines
2.2 KiB
YAML

# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
%YAML 1.2
---
$id: http://devicetree.org/schemas/thermal/generic-adc-thermal.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: General Purpose Analog To Digital Converter (ADC) based thermal sensor
maintainers:
- Laxman Dewangan <ldewangan@nvidia.com>
description:
On some of platforms, thermal sensor like thermistors are connected to
one of ADC channel and sensor resistance is read via voltage across the
sensor resistor. The voltage read across the sensor is mapped to
temperature using voltage-temperature lookup table.
properties:
compatible:
const: generic-adc-thermal
'#thermal-sensor-cells':
const: 0
io-channels:
maxItems: 1
io-channel-names:
const: sensor-channel
temperature-lookup-table:
description: |
Lookup table to map the relation between ADC value and temperature.
When ADC is read, the value is looked up on the table to get the
equivalent temperature.
If not specified, driver assumes the ADC channel gives milliCelsius
directly.
$ref: /schemas/types.yaml#/definitions/int32-matrix
items:
items:
- description: Temperature in milliCelsius
- description: ADC read value
required:
- compatible
- '#thermal-sensor-cells'
- io-channels
- io-channel-names
additionalProperties: false
examples:
- |
#include <dt-bindings/thermal/thermal.h>
thermal-sensor {
compatible = "generic-adc-thermal";
#thermal-sensor-cells = <0>;
io-channels = <&ads1015 1>;
io-channel-names = "sensor-channel";
temperature-lookup-table = <
(-40000) 2578
(-39000) 2577
(-38000) 2576
(-37000) 2575
(-36000) 2574
(-35000) 2573
(-34000) 2572
(-33000) 2571
(-32000) 2569
(-31000) 2568
(-30000) 2567
/* skip */
118000 254
119000 247
120000 240
121000 233
122000 226
123000 220
124000 214
125000 208>;
};
...