Commit 664b9879 authored by Olivier Moysan's avatar Olivier Moysan Committed by Jonathan Cameron
Browse files

dt-bindings: iio: stm32-adc: add generic channel binding 



Add ADC generic channel binding. This binding should
be used as an alternate to legacy channel properties
whenever possible.
ADC generic channel binding allows to identify supported
internal channels through the following reserved label names:
"vddcore", "vrefint" and "vbat".
This binding also allows to set a different sampling time
for each channel.

Signed-off-by: default avatarOlivier Moysan <olivier.moysan@foss.st.com>
Reviewed-by: default avatarFabrice Gasnier <fabrice.gasnier@foss.st.com>
Reviewed-by: default avatarRob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20211014131228.4692-2-olivier.moysan@foss.st.com


Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent 1ea3615b

Documentation/devicetree/bindings/iio/adc/st,stm32-adc.yaml

+93 −7
Original line number Diff line number Diff line
@@ -222,6 +222,12 @@ patternProperties: 
      '#io-channel-cells':

        const: 1



      '#address-cells':

        const: 1



      '#size-cells':

        const: 0



      interrupts:

        description: |

          IRQ Line for the ADC instance. Valid values are:
@@ -256,6 +262,7 @@ patternProperties: 
            - 20 channels, numbered from 0 to 19 (for in0..in19) on stm32h7 and

              stm32mp1.

        $ref: /schemas/types.yaml#/definitions/uint32-array

        deprecated: true



      st,adc-diff-channels:

        description: |
@@ -265,7 +272,9 @@ patternProperties: 
          <vinp vinn>, <vinp vinn>,... vinp and vinn are numbered from 0 to 19.



          Note: At least one of "st,adc-channels" or "st,adc-diff-channels" is

          required. Both properties can be used together. Some channels can be

          required if no adc generic channel is defined. These legacy channel

          properties are exclusive with adc generic channel bindings.

          Both properties can be used together. Some channels can be

          used as single-ended and some other ones as differential (mixed). But

          channels can't be configured both as single-ended and differential.

        $ref: /schemas/types.yaml#/definitions/uint32-matrix
@@ -279,6 +288,7 @@ patternProperties: 
                "vinn" indicates negative input number

              minimum: 0

              maximum: 19

        deprecated: true



      st,min-sample-time-nsecs:

        description:
@@ -289,6 +299,42 @@ patternProperties: 
          list, to set sample time resp. for all channels, or independently for

          each channel.

        $ref: /schemas/types.yaml#/definitions/uint32-array

        deprecated: true



    patternProperties:

      "^channel@([0-9]|1[0-9])$":

        type: object

        $ref: "adc.yaml"

        description: Represents the external channels which are connected to the ADC.



        properties:

          reg:

            items:

              minimum: 0

              maximum: 19



          label:

            description: |

              Unique name to identify which channel this is.

              Reserved label names "vddcore", "vrefint" and "vbat"

              are used to identify internal channels with matching names.



          diff-channels:

            $ref: /schemas/types.yaml#/definitions/uint32-array

            items:

              minimum: 0

              maximum: 19



          st,min-sample-time-ns:

            description: |

              Minimum sampling time in nanoseconds. Depending on hardware (board)

              e.g. high/low analog input source impedance, fine tune of ADC

              sampling time may be recommended.



        required:

          - reg



        additionalProperties: false



    allOf:

      - if:
@@ -369,12 +415,6 @@ patternProperties: 


    additionalProperties: false



    anyOf:

      - required:

          - st,adc-channels

      - required:

          - st,adc-diff-channels



    required:

      - compatible

      - reg
@@ -451,4 +491,50 @@ examples: 
        // other adc child node follow...

      };



  - |

    // Example 3: with stm32mp157c to setup ADC2 with:

    // - internal channels 13, 14, 15.

      #include <dt-bindings/interrupt-controller/arm-gic.h>

      #include <dt-bindings/clock/stm32mp1-clks.h>

      adc122: adc@48003000 {

        compatible = "st,stm32mp1-adc-core";

        reg = <0x48003000 0x400>;

        interrupts = <GIC_SPI 18 IRQ_TYPE_LEVEL_HIGH>,

                     <GIC_SPI 90 IRQ_TYPE_LEVEL_HIGH>;

        clocks = <&rcc ADC12>, <&rcc ADC12_K>;

        clock-names = "bus", "adc";

        booster-supply = <&booster>;

        vdd-supply = <&vdd>;

        vdda-supply = <&vdda>;

        vref-supply = <&vref>;

        st,syscfg = <&syscfg>;

        interrupt-controller;

        #interrupt-cells = <1>;

        #address-cells = <1>;

        #size-cells = <0>;

        adc@100 {

          compatible = "st,stm32mp1-adc";

          #io-channel-cells = <1>;

          reg = <0x100>;

          interrupts = <1>;

          #address-cells = <1>;

          #size-cells = <0>;

          channel@13 {

            reg = <13>;

            label = "vrefint";

            st,min-sample-time-ns = <9000>;

          };

          channel@14 {

            reg = <14>;

            label = "vddcore";

            st,min-sample-time-ns = <9000>;

          };

          channel@15 {

            reg = <15>;

            label = "vbat";

            st,min-sample-time-ns = <9000>;

          };

        };

      };



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