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