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# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
%YAML 1.2
---
$id: http://devicetree.org/schemas/power/supply/rohm,bd99954.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: ROHM BD99954 Battery charger
maintainers:
- Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
- Markus Laine <markus.laine@fi.rohmeurope.com>
- Mikko Mutanen <mikko.mutanen@fi.rohmeurope.com>
description: |
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.
properties:
compatible:
const: rohm,bd99954
#
# The battery charging profile of BD99954.
#
# Curve (1) represents charging current.
# Curve (2) represents battery voltage.
#
# The BD99954 data sheet divides charging to three phases.
# a) Trickle-charge with constant current (8).
# b) pre-charge with constant current (6)
# c) fast-charge with:
# First a constant current (5) phase (CC)
# Then constant voltage (CV) phase (after the battery voltage has reached
# target level - until charging current has dropped to termination
# level (7)
#
# V ^ ^ I
# . .
# . .
# (4)- -.- - - - - - - - - - - - - - +++++++++++++++++++++++++++.
# . / .
# . ++++++/++ - - - - - - - - - - - - -.- - (5)
# . + / + .
# . + - -- .
# . + - + .
# . +.- -: .
# . .+ +` .
# . .- + | `/ .
# . .." + .: .
# . -" + -- .
# . (2) ..." + | :- .
# . ..."" + -: .
# (3)- -.-.""- - - - -+++++++++ - - - - - - -.:- - - - - - - - - .- - (6)
# . + `:. .
# . + | -: .
# . + -: .
# . + .. .
# . (1) + | "+++- - - -.- - (7)
# -++++++++++++++- - - - - - - - - - - - - - - - - + - - - .- - (8)
# . + -
# -------------------------------------------------+++++++++-->
# | | | CC | CV |
# | --trickle-- | -pre- | ---------fast----------- |
#
# The charger uses the following battery properties
# - trickle-charge-current-microamp:
# Current used at trickle-charge phase (8 in above chart)
# minimum: 64000
# maximum: 1024000
# multipleOf: 64000
# - precharge-current-microamp:
# Current used at pre-charge phase (6 in above chart)
# minimum: 64000
# maximum: 1024000
# multipleOf: 64000
# - constant-charge-current-max-microamp
# Current used at fast charge constant current phase (5 in above chart)
# minimum: 64000
# maximum: 1024000
# multipleOf: 64000
# - constant-charge-voltage-max-microvolt
# The constant voltage used in fast charging phase (4 in above chart)
# minimum: 2560000
# maximum: 19200000
# multipleOf: 16000
# - precharge-upper-limit-microvolt
# charging mode is changed from trickle charging to pre-charging
# when battery voltage exceeds this limit voltage (3 in above chart)
# minimum: 2048000
# maximum: 19200000
# multipleOf: 64000
# - re-charge-voltage-microvolt
# minimum: 2560000
# maximum: 19200000
# multipleOf: 16000
# re-charging is automatically started when battry has been discharging
# to the point where the battery voltage drops below this limit
# - over-voltage-threshold-microvolt
# battery is expected to be faulty if battery voltage exceeds this limit.
# Charger will then enter to a "battery faulty" -state
# minimum: 2560000
# maximum: 19200000
# multipleOf: 16000
# - charge-term-current-microamp
# minimum: 0
# maximum: 1024000
# multipleOf: 64000
# a charge cycle terminates when the battery voltage is above recharge
# threshold, and the current is below this setting (7 in above chart)
# See also Documentation/devicetree/bindings/power/supply/battery.txt
monitored-battery:
description:
phandle of battery characteristics devicetree node
rohm,vsys-regulation-microvolt:
description: system specific lower limit for system voltage.
minimum: 2560000
maximum: 19200000
multipleOf: 64000
rohm,vbus-input-current-limit-microamp:
description: system specific VBUS input current limit (in microamps).
minimum: 32000
maximum: 16352000
multipleOf: 32000
rohm,vcc-input-current-limit-microamp:
description: system specific VCC/VACP input current limit (in microamps).
minimum: 32000
maximum: 16352000
multipleOf: 32000
required:
- compatible
examples:
- |
i2c {
#address-cells = <1>;
#size-cells = <0>;
charger@9 {
compatible = "rohm,bd99954";
monitored-battery = <&battery>;
reg = <0x9>;
interrupt-parent = <&gpio1>;
interrupts = <29 8>;
rohm,vsys-regulation-microvolt = <8960000>;
rohm,vbus-input-current-limit-microamp = <1472000>;
rohm,vcc-input-current-limit-microamp = <1472000>;
};
};
|
