1 # SPDX-License-Identifier: GPL-2.0-only OR BSD 1 # SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
2 %YAML 1.2 2 %YAML 1.2
3 --- 3 ---
4 $id: http://devicetree.org/schemas/thermal/gen 4 $id: http://devicetree.org/schemas/thermal/generic-adc-thermal.yaml#
5 $schema: http://devicetree.org/meta-schemas/co 5 $schema: http://devicetree.org/meta-schemas/core.yaml#
6 6
7 title: General Purpose Analog To Digital Conve 7 title: General Purpose Analog To Digital Converter (ADC) based thermal sensor
8 8
9 maintainers: 9 maintainers:
10 - Laxman Dewangan <ldewangan@nvidia.com> 10 - Laxman Dewangan <ldewangan@nvidia.com>
11 11
12 description: 12 description:
13 On some of platforms, thermal sensor like th 13 On some of platforms, thermal sensor like thermistors are connected to
14 one of ADC channel and sensor resistance is 14 one of ADC channel and sensor resistance is read via voltage across the
15 sensor resistor. The voltage read across the 15 sensor resistor. The voltage read across the sensor is mapped to
16 temperature using voltage-temperature lookup 16 temperature using voltage-temperature lookup table.
17 17
18 $ref: thermal-sensor.yaml# 18 $ref: thermal-sensor.yaml#
19 19
20 properties: 20 properties:
21 compatible: 21 compatible:
22 const: generic-adc-thermal 22 const: generic-adc-thermal
23 23
24 '#thermal-sensor-cells': 24 '#thermal-sensor-cells':
25 const: 0 25 const: 0
26 26
27 io-channels: 27 io-channels:
28 maxItems: 1 28 maxItems: 1
29 29
30 io-channel-names: 30 io-channel-names:
31 const: sensor-channel 31 const: sensor-channel
32 32
33 temperature-lookup-table: 33 temperature-lookup-table:
34 description: | 34 description: |
35 Lookup table to map the relation between 35 Lookup table to map the relation between ADC value and temperature.
36 When ADC is read, the value is looked up 36 When ADC is read, the value is looked up on the table to get the
37 equivalent temperature. 37 equivalent temperature.
38 38
39 If not specified, driver assumes the ADC 39 If not specified, driver assumes the ADC channel gives milliCelsius
40 directly. 40 directly.
41 $ref: /schemas/types.yaml#/definitions/int 41 $ref: /schemas/types.yaml#/definitions/int32-matrix
42 items: 42 items:
43 items: 43 items:
44 - description: Temperature in milliCel 44 - description: Temperature in milliCelsius
45 - description: ADC read value 45 - description: ADC read value
46 46
47 required: 47 required:
48 - compatible 48 - compatible
49 - io-channels 49 - io-channels
50 - io-channel-names 50 - io-channel-names
51 51
52 unevaluatedProperties: false 52 unevaluatedProperties: false
53 53
54 examples: 54 examples:
55 - | 55 - |
56 #include <dt-bindings/thermal/thermal.h> 56 #include <dt-bindings/thermal/thermal.h>
57 57
58 thermal-sensor { 58 thermal-sensor {
59 compatible = "generic-adc-thermal"; 59 compatible = "generic-adc-thermal";
60 #thermal-sensor-cells = <0>; 60 #thermal-sensor-cells = <0>;
61 io-channels = <&ads1015 1>; 61 io-channels = <&ads1015 1>;
62 io-channel-names = "sensor-channel"; 62 io-channel-names = "sensor-channel";
63 temperature-lookup-table = < 63 temperature-lookup-table = <
64 (-40000) 2578 64 (-40000) 2578
65 (-39000) 2577 65 (-39000) 2577
66 (-38000) 2576 66 (-38000) 2576
67 (-37000) 2575 67 (-37000) 2575
68 (-36000) 2574 68 (-36000) 2574
69 (-35000) 2573 69 (-35000) 2573
70 (-34000) 2572 70 (-34000) 2572
71 (-33000) 2571 71 (-33000) 2571
72 (-32000) 2569 72 (-32000) 2569
73 (-31000) 2568 73 (-31000) 2568
74 (-30000) 2567 74 (-30000) 2567
75 /* skip */ 75 /* skip */
76 118000 254 76 118000 254
77 119000 247 77 119000 247
78 120000 240 78 120000 240
79 121000 233 79 121000 233
80 122000 226 80 122000 226
81 123000 220 81 123000 220
82 124000 214 82 124000 214
83 125000 208>; 83 125000 208>;
84 }; 84 };
85 ... 85 ...
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