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 reg: 116 maxItems: 1 117 118 interrupts: 119 maxItems: 1 120 121 monitored-battery: 122 description: 123 phandle of battery characteristics devicetree node 124 125 rohm,vsys-regulation-microvolt: 126 description: system specific lower limit for system voltage. 127 minimum: 2560000 128 maximum: 19200000 129 multipleOf: 64000 130 131 rohm,vbus-input-current-limit-microamp: 132 description: system specific VBUS input current limit (in microamps). 133 minimum: 32000 134 maximum: 16352000 135 multipleOf: 32000 136 137 rohm,vcc-input-current-limit-microamp: 138 description: system specific VCC/VACP input current limit (in microamps). 139 minimum: 32000 140 maximum: 16352000 141 multipleOf: 32000 142 143required: 144 - compatible 145 146additionalProperties: false 147 148examples: 149 - | 150 i2c { 151 #address-cells = <1>; 152 #size-cells = <0>; 153 charger@9 { 154 compatible = "rohm,bd99954"; 155 monitored-battery = <&battery>; 156 reg = <0x9>; 157 interrupt-parent = <&gpio1>; 158 interrupts = <29 8>; 159 rohm,vsys-regulation-microvolt = <8960000>; 160 rohm,vbus-input-current-limit-microamp = <1472000>; 161 rohm,vcc-input-current-limit-microamp = <1472000>; 162 }; 163 }; 164