Kernel-4.18.0-80.el8_st,stm32-dac

STMicroelectronics STM32 DAC

The STM32 DAC is a 12-bit voltage output digital-to-analog converter. The DAC
may be configured in 8 or 12-bit mode. It has two output channels, each with
its own converter.
It has built-in noise and triangle waveform generator and supports external
triggers for conversions. The DAC’s output buffer allows a high drive output
current.

Contents of a stm32 dac root node:

Required properties:

  • compatible: Should be one of:
    “st,stm32f4-dac-core”
    “st,stm32h7-dac-core”
  • reg: Offset and length of the device’s register set.
  • clocks: Must contain an entry for pclk (which feeds the peripheral bus
    interface)
  • clock-names: Must be “pclk”.
  • vref-supply: Phandle to the vref+ input analog reference supply.
  • #address-cells = <1>;
  • #size-cells = <0>;

Optional properties:

  • resets: Must contain the phandle to the reset controller.
  • A pinctrl state named “default” for each DAC channel may be defined to set
    DAC_OUTx pin in mode of operation for analog output on external pin.

Contents of a stm32 dac child node:

DAC core node should contain at least one subnode, representing a
DAC instance/channel available on the machine.

Required properties:

  • compatible: Must be “st,stm32-dac”.
  • reg: Must be either 1 or 2, to define (single) channel in use
  • #io-channel-cells = <1>: See the IIO bindings section “IIO consumers” in
    Documentation/devicetree/bindings/iio/iio-bindings.txt

Example:
dac: dac@40007400 {
compatible = “st,stm32h7-dac-core”;
reg = <0x40007400 0x400>;
clocks = <&clk>;
clock-names = “pclk”;
vref-supply = <&reg_vref>;
pinctrl-names = “default”;
pinctrl-0 = <&dac_out1 &dac_out2>;
#address-cells = <1>;
#size-cells = <0>;

    dac1: dac@1 {
        compatible = "st,stm32-dac";
        #io-channels-cells = <1>;
        reg = <1>;
    };

    dac2: dac@2 {
        compatible = "st,stm32-dac";
        #io-channels-cells = <1>;
        reg = <2>;
    };
};