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>

1 files changed, 155 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/power/supply/rohm,bd99954.yaml b/Documentation/devicetree/bindings/power/supply/rohm,bd99954.yaml
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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>;
+        };
+    };