[RFC PATCH v3 2/8] dt_bindings: ROHM BD99954 Charger
From: Matti Vaittinen
Date: Thu Feb 20 2020 - 02:35:22 EST
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@xxxxxxxxxxxxxxxxx>
---
.../bindings/power/supply/rohm,bd9995x.yaml | 153 ++++++++++++++++++
1 file changed, 153 insertions(+)
create mode 100644 Documentation/devicetree/bindings/power/supply/rohm,bd9995x.yaml
diff --git a/Documentation/devicetree/bindings/power/supply/rohm,bd9995x.yaml b/Documentation/devicetree/bindings/power/supply/rohm,bd9995x.yaml
new file mode 100644
index 000000000000..032aaa0a305e
--- /dev/null
+++ b/Documentation/devicetree/bindings/power/supply/rohm,bd9995x.yaml
@@ -0,0 +1,153 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/power/supply/rohm,bd9995x.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ROHM BD99954 Battery charger driver
+
+maintainers:
+ - Matti Vaittinen <matti.vaittinen@xxxxxxxxxxxxxxxxx>
+ - Markus Laine <markus.laine@xxxxxxxxxxxxxxxxx>
+ - Mikko Mutanen <mikko.mutanen@xxxxxxxxxxxxxxxxx>
+
+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,bd9995x-charger
+#
+# 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 {
+ charger@9 {
+ compatible = "rohm,bd9995x-charger";
+ 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>;
+ };
+ };
--
2.21.0
--
Matti Vaittinen, Linux device drivers
ROHM Semiconductors, Finland SWDC
Kiviharjunlenkki 1E
90220 OULU
FINLAND
~~~ "I don't think so," said Rene Descartes. Just then he vanished ~~~
Simon says - in Latin please.
~~~ "non cogito me" dixit Rene Descarte, deinde evanescavit ~~~
Thanks to Simon Glass for the translation =]