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/rohm,bd99954.yaml#
5 $schema: http://devicetree.org/meta-schemas/core.yaml#
6
7 title: ROHM BD99954 Battery charger
8
9 maintainers:
10 - Matti Vaittinen <mazziesaccount@gmail.com>
11 - Markus Laine <markus.laine@fi.rohmeurope.com>
12 - Mikko Mutanen <mikko.mutanen@fi.rohmeurope.com>
13
14 description: |
15 The ROHM BD99954 is a Battery Management LSI for 1-4 cell Lithium-Ion
16 secondary battery intended to be used in space-constraint equipment such
17 as Low profile Notebook PC, Tablets and other applications. BD99954
18 provides a Dual-source Battery Charger, two port BC1.2 detection and a
19 Battery Monitor.
20
21 $ref: power-supply.yaml#
22
23 properties:
24 compatible:
25 const: rohm,bd99954
26 #
27 # The battery charging profile of BD99954.
28 #
29 # Curve (1) represents charging current.
30 # Curve (2) represents battery voltage.
31 #
32 # The BD99954 data sheet divides charging to three phases.
33 # a) Trickle-charge with constant current (8).
34 # b) pre-charge with constant current (6)
35 # c) fast-charge with:
36 # First a constant current (5) phase (CC)
37 # Then constant voltage (CV) phase (after the battery voltage has reached
38 # target level - until charging current has dropped to termination
39 # level (7)
40 #
41 # V ^ ^ I
42 # . .
43 # . .
44 # (4)- -.- - - - - - - - - - - - - - +++++++++++++++++++++++++++.
45 # . / .
46 # . ++++++/++ - - - - - - - - - - - - -.- - (5)
47 # . + / + .
48 # . + - -- .
49 # . + - + .
50 # . +.- -: .
51 # . .+ +` .
52 # . .- + | `/ .
53 # . .." + .: .
54 # . -" + -- .
55 # . (2) ..." + | :- .
56 # . ..."" + -: .
57 # (3)- -.-.""- - - - -+++++++++ - - - - - - -.:- - - - - - - - - .- - (6)
58 # . + `:. .
59 # . + | -: .
60 # . + -: .
61 # . + .. .
62 # . (1) + | "+++- - - -.- - (7)
63 # -++++++++++++++- - - - - - - - - - - - - - - - - + - - - .- - (8)
64 # . + -
65 # -------------------------------------------------+++++++++-->
66 # | | | CC | CV |
67 # | --trickle-- | -pre- | ---------fast----------- |
68 #
69 # The charger uses the following battery properties
70 # - trickle-charge-current-microamp:
71 # Current used at trickle-charge phase (8 in above chart)
72 # minimum: 64000
73 # maximum: 1024000
74 # multipleOf: 64000
75 # - precharge-current-microamp:
76 # Current used at pre-charge phase (6 in above chart)
77 # minimum: 64000
78 # maximum: 1024000
79 # multipleOf: 64000
80 # - constant-charge-current-max-microamp
81 # Current used at fast charge constant current phase (5 in above chart)
82 # minimum: 64000
83 # maximum: 1024000
84 # multipleOf: 64000
85 # - constant-charge-voltage-max-microvolt
86 # The constant voltage used in fast charging phase (4 in above chart)
87 # minimum: 2560000
88 # maximum: 19200000
89 # multipleOf: 16000
90 # - precharge-upper-limit-microvolt
91 # charging mode is changed from trickle charging to pre-charging
92 # when battery voltage exceeds this limit voltage (3 in above chart)
93 # minimum: 2048000
94 # maximum: 19200000
95 # multipleOf: 64000
96 # - re-charge-voltage-microvolt
97 # minimum: 2560000
98 # maximum: 19200000
99 # multipleOf: 16000
100 # re-charging is automatically started when battry has been discharging
101 # to the point where the battery voltage drops below this limit
102 # - over-voltage-threshold-microvolt
103 # battery is expected to be faulty if battery voltage exceeds this limit.
104 # Charger will then enter to a "battery faulty" -state
105 # minimum: 2560000
106 # maximum: 19200000
107 # multipleOf: 16000
108 # - charge-term-current-microamp
109 # minimum: 0
110 # maximum: 1024000
111 # multipleOf: 64000
112 # a charge cycle terminates when the battery voltage is above recharge
113 # threshold, and the current is below this setting (7 in above chart)
114 # See also Documentation/devicetree/bindings/power/supply/battery.yaml
115
116 reg:
117 maxItems: 1
118
119 interrupts:
120 maxItems: 1
121
122 monitored-battery:
123 description:
124 phandle of battery characteristics devicetree node
125
126 rohm,vsys-regulation-microvolt:
127 description: system specific lower limit for system voltage.
128 minimum: 2560000
129 maximum: 19200000
130 multipleOf: 64000
131
132 rohm,vbus-input-current-limit-microamp:
133 description: system specific VBUS input current limit (in microamps).
134 minimum: 32000
135 maximum: 16352000
136 multipleOf: 32000
137
138 rohm,vcc-input-current-limit-microamp:
139 description: system specific VCC/VACP input current limit (in microamps).
140 minimum: 32000
141 maximum: 16352000
142 multipleOf: 32000
143
144 required:
145 - compatible
146
147 additionalProperties: false
148
149 examples:
150 - |
151 i2c {
152 #address-cells = <1>;
153 #size-cells = <0>;
154 charger@9 {
155 compatible = "rohm,bd99954";
156 monitored-battery = <&battery>;
157 reg = <0x9>;
158 interrupt-parent = <&gpio1>;
159 interrupts = <29 8>;
160 rohm,vsys-regulation-microvolt = <8960000>;
161 rohm,vbus-input-current-limit-microamp = <1472000>;
162 rohm,vcc-input-current-limit-microamp = <1472000>;
163 };
164 };
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.