Kernel-4.18.0-80.el8_at91_adc

  • AT91’s Analog to Digital Converter (ADC)

Required properties:

  • compatible: Should be “atmel,-adc”
    can be “at91sam9260”, “at91sam9g45” or “at91sam9x5”
  • reg: Should contain ADC registers location and length
  • interrupts: Should contain the IRQ line for the ADC
  • clock-names: tuple listing input clock names.
    Required elements: “adc_clk”, “adc_op_clk”.
  • clocks: phandles to input clocks.
  • atmel,adc-channels-used: Bitmask of the channels muxed and enabled for this
    device
  • atmel,adc-startup-time: Startup Time of the ADC in microseconds as
    defined in the datasheet
  • atmel,adc-vref: Reference voltage in millivolts for the conversions
  • atmel,adc-res: List of resolutions in bits supported by the ADC. List size
       must be two at least.
    
  • atmel,adc-res-names: Contains one identifier string for each resolution
         in atmel,adc-res property. "lowres" and "highres"
         identifiers are required.
    

Optional properties:

  • atmel,adc-use-external-triggers: Boolean to enable the external triggers
  • atmel,adc-use-res: String corresponding to an identifier from
           atmel,adc-res-names property. If not specified, the highest
           resolution will be used.
    
  • atmel,adc-sleep-mode: Boolean to enable sleep mode when no conversion
  • atmel,adc-sample-hold-time: Sample and Hold Time in microseconds
  • atmel,adc-ts-wires: Number of touchscreen wires. Should be 4 or 5. If this
                    value is set, then the adc driver will enable touchscreen
                    support.
    
    NOTE: when adc touchscreen is enabled, the adc hardware trigger will be
      disabled. Since touchscreen will occupy the trigger register.
    
  • atmel,adc-ts-pressure-threshold: a pressure threshold for touchscreen. It
                                 makes touch detection more precise.
    

Optional trigger Nodes:

  • Required properties:
    • trigger-name: Name of the trigger exposed to the user
    • trigger-value: Value to put in the Trigger register
      to activate this trigger
  • Optional properties:
    • trigger-external: Is the trigger an external trigger?

Examples:
adc0: adc@fffb0000 {
#address-cells = <1>;
#size-cells = <0>;
compatible = “atmel,at91sam9260-adc”;
reg = <0xfffb0000 0x100>;
interrupts = <20 IRQ_TYPE_LEVEL_HIGH 0>;
clocks = <&adc_clk>, <&adc_op_clk>;
clock-names = “adc_clk”, “adc_op_clk”;
atmel,adc-channels-used = <0xff>;
atmel,adc-startup-time = <40>;
atmel,adc-use-external-triggers;
atmel,adc-vref = <3300>;
atmel,adc-res = <8 10>;
atmel,adc-res-names = “lowres”, “highres”;
atmel,adc-use-res = “lowres”;

trigger0 {
    trigger-name = "external-rising";
    trigger-value = <0x1>;
    trigger-external;
};
trigger1 {
    trigger-name = "external-falling";
    trigger-value = <0x2>;
    trigger-external;
};

trigger2 {
    trigger-name = "external-any";
    trigger-value = <0x3>;
    trigger-external;
};

trigger3 {
    trigger-name = "continuous";
    trigger-value = <0x6>;
};

};