1General Purpose Analog To Digital Converter (ADC) based thermal sensor.
2
3On some of platforms, thermal sensor like thermistors are connected to
4one of ADC channel and sensor resistance is read via voltage across the
5sensor resistor. The voltage read across the sensor is mapped to
6temperature using voltage-temperature lookup table.
7
8Required properties:
9===================
10- compatible:		     Must be "generic-adc-thermal".
11- temperature-lookup-table:  Two dimensional array of Integer; lookup table
12			     to map the relation between ADC value and
13			     temperature. When ADC is read, the value is
14			     looked up on the table to get the equivalent
15			     temperature.
16			     The first value of the each row of array is the
17			     temperature in milliCelsius and second value of
18			     the each row of array is the ADC read value.
19- #thermal-sensor-cells:     Should be 1. See ./thermal.txt for a description
20			     of this property.
21
22Example :
23#include <dt-bindings/thermal/thermal.h>
24
25i2c@7000c400 {
26	ads1015: ads1015@4a {
27		reg = <0x4a>;
28		compatible = "ads1015";
29		sampling-frequency = <3300>;
30		#io-channel-cells = <1>;
31	};
32};
33
34tboard_thermistor: thermal-sensor {
35	compatible = "generic-adc-thermal";
36	#thermal-sensor-cells = <0>;
37	io-channels = <&ads1015 1>;
38	io-channel-names = "sensor-channel";
39	temperature-lookup-table = <    (-40000) 2578
40					(-39000) 2577
41					(-38000) 2576
42					(-37000) 2575
43					(-36000) 2574
44					(-35000) 2573
45					(-34000) 2572
46					(-33000) 2571
47					(-32000) 2569
48					(-31000) 2568
49					(-30000) 2567
50					::::::::::
51					118000 254
52					119000 247
53					120000 240
54					121000 233
55					122000 226
56					123000 220
57					124000 214
58					125000 208>;
59};
60
61dummy_cool_dev: dummy-cool-dev {
62	compatible = "dummy-cooling-dev";
63	#cooling-cells = <2>; /* min followed by max */
64};
65
66thermal-zones {
67	Tboard {
68		polling-delay = <15000>; /* milliseconds */
69		polling-delay-passive = <0>; /* milliseconds */
70		thermal-sensors = <&tboard_thermistor>;
71
72		trips {
73			therm_est_trip: therm_est_trip {
74				temperature = <40000>;
75				type = "active";
76				hysteresis = <1000>;
77			};
78		};
79
80		cooling-maps {
81			map0 {
82				trip = <&therm_est_trip>;
83				cooling-device = <&dummy_cool_dev THERMAL_NO_LIMIT THERMAL_NO_LIMIT>;
84				contribution = <100>;
85			};
86
87		};
88	};
89};
90