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 <mazziesaccount@gmail.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 $ref: power-supply.yaml#
  22
  23 properties:
  24   compatible:
  25     const: rohm,bd99954
  26 #
  27 #    The battery charging profile of BD99954.
  28 #
  29 #    Curve (1) represents charging current.
  30 #    Curve (2) represents battery voltage.
  31 #
  32 #    The BD99954 data sheet divides charging to three phases.
  33 #    a) Trickle-charge with constant current (8).
  34 #    b) pre-charge with constant current (6)
  35 #    c) fast-charge with:
  36 #       First a constant current (5) phase (CC)
  37 #       Then constant voltage (CV) phase (after the battery voltage has reached
  38 #       target level - until charging current has dropped to termination
  39 #       level (7)
  40 #
  41 #     V ^                                                        ^ I
  42 #       .                                                        .
  43 #       .                                                        .
  44 # (4)- -.- - - - - - - - - - - - - -  +++++++++++++++++++++++++++.
  45 #       .                            /                           .
  46 #       .                     ++++++/++ - - - - - - - - - - - - -.- - (5)
  47 #       .                     +    /  +                          .
  48 #       .                     +   -   --                         .
  49 #       .                     +  -     +                         .
  50 #       .                     +.-      -:                        .
  51 #       .                    .+         +`                       .
  52 #       .                  .- +       | `/                       .
  53 #       .               .."   +          .:                      .
  54 #       .             -"      +           --                     .
  55 #       .    (2)  ..."        +       |    :-                    .
  56 #       .    ...""            +             -:                   .
  57 # (3)- -.-.""- - - - -+++++++++ - - - - - - -.:- - - - - - - - - .- - (6)
  58 #       .             +                       `:.                .
  59 #       .             +               |         -:               .
  60 #       .             +                           -:             .
  61 #       .             +                             ..           .
  62 #       .   (1)       +               |               "+++- - - -.- - (7)
  63 #       -++++++++++++++- - - - - - - - - - - - - - - - - + - - - .- - (8)
  64 #       .                                                +       -
  65 #       -------------------------------------------------+++++++++-->
  66 #       |             |       |   CC   |      CV         |
  67 #       | --trickle-- | -pre- | ---------fast----------- |
  68 #
  69 #   The charger uses the following battery properties
  70 # - trickle-charge-current-microamp:
  71 #     Current used at trickle-charge phase (8 in above chart)
  72 #     minimum: 64000
  73 #     maximum: 1024000
  74 #     multipleOf: 64000
  75 # - precharge-current-microamp:
  76 #     Current used at pre-charge phase (6 in above chart)
  77 #     minimum: 64000
  78 #     maximum: 1024000
  79 #     multipleOf: 64000
  80 # - constant-charge-current-max-microamp
  81 #     Current used at fast charge constant current phase (5 in above chart)
  82 #     minimum: 64000
  83 #     maximum: 1024000
  84 #     multipleOf: 64000
  85 # - constant-charge-voltage-max-microvolt
  86 #     The constant voltage used in fast charging phase (4 in above chart)
  87 #     minimum: 2560000
  88 #     maximum: 19200000
  89 #     multipleOf: 16000
  90 # - precharge-upper-limit-microvolt
  91 #     charging mode is changed from trickle charging to pre-charging
  92 #     when battery voltage exceeds this limit voltage (3 in above chart)
  93 #     minimum: 2048000
  94 #     maximum: 19200000
  95 #     multipleOf: 64000
  96 # - re-charge-voltage-microvolt
  97 #     minimum: 2560000
  98 #     maximum: 19200000
  99 #     multipleOf: 16000
 100 #     re-charging is automatically started when battry has been discharging
 101 #     to the point where the battery voltage drops below this limit
 102 # - over-voltage-threshold-microvolt
 103 #     battery is expected to be faulty if battery voltage exceeds this limit.
 104 #     Charger will then enter to a "battery faulty" -state
 105 #     minimum: 2560000
 106 #     maximum: 19200000
 107 #     multipleOf: 16000
 108 # - charge-term-current-microamp
 109 #     minimum: 0
 110 #     maximum: 1024000
 111 #     multipleOf: 64000
 112 #     a charge cycle terminates when the battery voltage is above recharge
 113 #     threshold, and the current is below this setting (7 in above chart)
 114 #   See also Documentation/devicetree/bindings/power/supply/battery.yaml
 115
 116   reg:
 117     maxItems: 1
 118
 119   interrupts:
 120     maxItems: 1
 121
 122   monitored-battery:
 123     description:
 124       phandle of battery characteristics devicetree node
 125
 126   rohm,vsys-regulation-microvolt:
 127     description: system specific lower limit for system voltage.
 128     minimum: 2560000
 129     maximum: 19200000
 130     multipleOf: 64000
 131
 132   rohm,vbus-input-current-limit-microamp:
 133     description: system specific VBUS input current limit (in microamps).
 134     minimum: 32000
 135     maximum: 16352000
 136     multipleOf: 32000
 137
 138   rohm,vcc-input-current-limit-microamp:
 139     description: system specific VCC/VACP input current limit (in microamps).
 140     minimum: 32000
 141     maximum: 16352000
 142     multipleOf: 32000
 143
 144 required:
 145   - compatible
 146
 147 additionalProperties: false
 148
 149 examples:
 150   - |
 151     i2c {
 152         #address-cells = <1>;
 153         #size-cells = <0>;
 154         charger@9 {
 155             compatible = "rohm,bd99954";
 156             monitored-battery = <&battery>;
 157             reg = <0x9>;
 158             interrupt-parent = <&gpio1>;
 159             interrupts = <29 8>;
 160             rohm,vsys-regulation-microvolt = <8960000>;
 161             rohm,vbus-input-current-limit-microamp = <1472000>;
 162             rohm,vcc-input-current-limit-microamp = <1472000>;
 163         };
 164     };