Documentation/devicetree/bindings/iio/dac/dpot-dac.txt

   1 Bindings for DAC emulation using a digital potentiometer
   2
   3 It is assumed that the dpot is used as a voltage divider between the
   4 current dpot wiper setting and the maximum resistance of the dpot. The
   5 divided voltage is provided by a vref regulator.
   6
   7                   .------.
   8    .-----------.  |      |
   9    | vref      |--'    .---.
  10    | regulator |--.    |   |
  11    '-----------'  |    | d |
  12                   |    | p |
  13                   |    | o |  wiper
  14                   |    | t |<---------+
  15                   |    |   |
  16                   |    '---'       dac output voltage
  17                   |      |
  18                   '------+------------+
  19
  20 Required properties:
  21 - compatible: Should be "dpot-dac"
  22 - vref-supply: The regulator supplying the voltage divider.
  23 - io-channels: Channel node of the dpot to be used for the voltage division.
  24 - io-channel-names: Should be "dpot".
  25
  26 Example:
  27
  28         &i2c {
  29                 dpot: mcp4651-503@28 {
  30                         compatible = "microchip,mcp4651-503";
  31                         reg = <0x28>;
  32                         #io-channel-cells = <1>;
  33                 };
  34         };
  35
  36         dac {
  37                 compatible = "dpot-dac";
  38                 vref-supply = <&reg_3v3>;
  39                 io-channels = <&dpot 0>;
  40                 io-channel-names = "dpot";
  41         };