xref: /freebsd/sys/contrib/device-tree/Bindings/power/supply/battery.yaml (revision c66ec88fed842fbaad62c30d510644ceb7bd2d71) 
1# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2%YAML 1.2
3---
4$id: http://devicetree.org/schemas/power/supply/battery.yaml#
5$schema: http://devicetree.org/meta-schemas/core.yaml#
6
7title: Battery Characteristics
8
9maintainers:
10  - Sebastian Reichel <sre@kernel.org>
11
12description: |
13  The devicetree battery node provides static battery characteristics.
14  In smart batteries, these are typically stored in non-volatile memory
15  on a fuel gauge chip. The battery node should be used where there is
16  no appropriate non-volatile memory, or it is unprogrammed/incorrect.
17
18  Upstream dts files should not include battery nodes, unless the battery
19  represented cannot easily be replaced in the system by one of a
20  different type. This prevents unpredictable, potentially harmful,
21  behavior should a replacement that changes the battery type occur
22  without a corresponding update to the dtb.
23
24  Battery properties are named, where possible, for the corresponding elements
25  in enum power_supply_property, defined in include/linux/power_supply.h
26
27  Batteries must be referenced by chargers and/or fuel-gauges using a phandle.
28  The phandle's property should be named "monitored-battery".
29
30properties:
31  compatible:
32    const: simple-battery
33
34  over-voltage-threshold-microvolt:
35    description: battery over-voltage limit
36
37  re-charge-voltage-microvolt:
38    description: limit to automatically start charging again
39
40  voltage-min-design-microvolt:
41    description: drained battery voltage
42
43  voltage-max-design-microvolt:
44    description: fully charged battery voltage
45
46  energy-full-design-microwatt-hours:
47    description: battery design energy
48
49  charge-full-design-microamp-hours:
50    description: battery design capacity
51
52  trickle-charge-current-microamp:
53    description: current for trickle-charge phase
54
55  precharge-current-microamp:
56    description: current for pre-charge phase
57
58  precharge-upper-limit-microvolt:
59    description: limit when to change to constant charging
60
61  charge-term-current-microamp:
62    description: current for charge termination phase
63
64  constant-charge-current-max-microamp:
65    description: maximum constant input current
66
67  constant-charge-voltage-max-microvolt:
68    description: maximum constant input voltage
69
70  factory-internal-resistance-micro-ohms:
71    description: battery factory internal resistance
72
73  resistance-temp-table:
74    description: |
75      An array providing the temperature in degree Celsius
76      and corresponding battery internal resistance percent, which is used to
77      look up the resistance percent according to current temperature to get an
78      accurate batterty internal resistance in different temperatures.
79
80  ocv-capacity-celsius:
81    description: |
82      An array containing the temperature in degree Celsius,
83      for each of the battery capacity lookup table.
84
85required:
86  - compatible
87
88patternProperties:
89  '^ocv-capacity-table-[0-9]+$':
90    $ref: /schemas/types.yaml#/definitions/uint32-matrix
91    description: |
92      An array providing the open circuit voltage (OCV)
93      of the battery and corresponding battery capacity percent, which is used
94      to look up battery capacity according to current OCV value. And the open
95      circuit voltage unit is microvolt.
96    maxItems: 100
97    items:
98      items:
99        - description: open circuit voltage (OCV) in microvolts
100        - description: battery capacity percent
101          maximum: 100
102
103additionalProperties: false
104
105examples:
106  - |
107    power {
108      #address-cells = <1>;
109      #size-cells = <0>;
110
111      battery: battery {
112        compatible = "simple-battery";
113        over-voltage-threshold-microvolt = <4500000>;
114        re-charge-voltage-microvolt = <250000>;
115        voltage-min-design-microvolt = <3200000>;
116        voltage-max-design-microvolt = <4200000>;
117        energy-full-design-microwatt-hours = <5290000>;
118        charge-full-design-microamp-hours = <1430000>;
119        precharge-current-microamp = <256000>;
120        precharge-upper-limit-microvolt = <2500000>;
121        charge-term-current-microamp = <128000>;
122        constant-charge-current-max-microamp = <900000>;
123        constant-charge-voltage-max-microvolt = <4200000>;
124        factory-internal-resistance-micro-ohms = <250000>;
125        ocv-capacity-celsius = <(-10) 0 10>;
126        /* table for -10 degree Celsius */
127        ocv-capacity-table-0 = <4185000 100>, <4113000 95>, <4066000 90>;
128        /* table for 0 degree Celsius */
129        ocv-capacity-table-1 = <4200000 100>, <4185000 95>, <4113000 90>;
130        /* table for 10 degree Celsius */
131        ocv-capacity-table-2 = <4250000 100>, <4200000 95>, <4185000 90>;
132        resistance-temp-table = <20 100>, <10 90>, <0 80>, <(-10) 60>;
133      };
134
135      charger@11 {
136        reg = <0x11>;
137        monitored-battery = <&battery>;
138      };
139
140      fuel-gauge@22 {
141        reg = <0x22>;
142        monitored-battery = <&battery>;
143      };
144    };
145