tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
dt_bindings: ROHM BD99954 Charger
The ROHM BD99954 is a Battery Management LSI for 1-4 cell Lithium-Ion
secondary battery. Intended to be used in space-constraint equipment such
as Low profile Notebook PC, Tablets and other applications. BD99954
provides a Dual-source Battery Charger, two port BC1.2 detection and a
Battery Monitor.
Document the DT bindings for BD99954
Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
authored by
Matti Vaittinen
and committed by
Sebastian Reichel
2a75c8a4
5a63b7ba
+155
+155
Documentation/devicetree/bindings/power/supply/rohm,bd99954.yaml
+155
Documentation/devicetree/bindings/power/supply/rohm,bd99954.yaml
···
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 <matti.vaittinen@fi.rohmeurope.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
+
22
+
properties:
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
+
137
+
required:
138
+
- compatible
139
+
140
+
examples:
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
+
};