Re: [RFC v2 03/11] dt-bindings: iio: stm32-dfsdm-adc: add scaling support

Hi Rob,

On 8/11/23 19:10, Rob Herring wrote:

On Thu, Jul 27, 2023 at 05:03:14PM +0200, Olivier Moysan wrote:

...

Add scaling support to STM32 DFSDM.

This introduces the following changes:

Why?

This RFC is an attempt to support scaling through a change in DFSDM topology.

These changes have some impacts on DFSDM and sd modulator bindings. To keep things simple in this RFC, I skipped legacy support, to put the emphasis on the new bindings proposal. There are two changes here: adoption of the generic IIO bindings and new "io-backends" property. This needs to be put in two separate patches at the end, I think (as already done for driver patches)

Anyway, the current bindings would become deprecated with these changes. I still have to consider how to support these legacy bindings for next step, However.

BRs Olivier

...

• Add ADC generic channel binding and remove support of deprecated

channel bindings.

When was it deprecated?

...

• DFSDM is now implemented as a channel provider, so remove io-channels

properties.

• Add iio-backend property to connect DFSDM to an SD modulator.

io-backends

All sorts of ABI issues with this change. Please explain why you don't care.

...

Signed-off-by: Olivier Moysan olivier.moysan@foss.st.com

.../bindings/iio/adc/st,stm32-dfsdm-adc.yaml | 189 ++++++------------ 1 file changed, 63 insertions(+), 126 deletions(-)

diff --git a/Documentation/devicetree/bindings/iio/adc/st,stm32-dfsdm-adc.yaml b/Documentation/devicetree/bindings/iio/adc/st,stm32-dfsdm-adc.yaml index 1970503389aa..128545cedc7f 100644 --- a/Documentation/devicetree/bindings/iio/adc/st,stm32-dfsdm-adc.yaml +++ b/Documentation/devicetree/bindings/iio/adc/st,stm32-dfsdm-adc.yaml @@ -85,22 +85,14 @@ patternProperties: description: Specifies the DFSDM filter instance used. maxItems: 1

•  interrupts:
  

•    maxItems: 1
  

•  '#address-cells':
  

•    const: 1
  
  

•  st,adc-channels:
  

•    description: |
  

•      List of single-ended channels muxed for this ADC.
  

•      On stm32h7 and stm32mp1:
  

•      - For st,stm32-dfsdm-adc: up to 8 channels numbered from 0 to 7.
  

•      - For st,stm32-dfsdm-dmic: 1 channel numbered from 0 to 7.
  

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

•    items:
  

•      minimum: 0
  

•      maximum: 7
  

•  '#size-cells':
  

•    const: 0
  
  

•  st,adc-channel-names:
  

•    description: List of single-ended channel names.
  

•  interrupts:
  

•    maxItems: 1
  
    st,filter-order:
      description: |
  

@@ -111,39 +103,6 @@ patternProperties: $ref: /schemas/types.yaml#/definitions/uint32 maximum: 5

•  "#io-channel-cells":
  

•    const: 1
  

•  st,adc-channel-types:
  

•    description: |
  

•      Single-ended channel input type.
  

•      - "SPI_R": SPI with data on rising edge (default)
  

•      - "SPI_F": SPI with data on falling edge
  

•      - "MANCH_R": manchester codec, rising edge = logic 0, falling edge = logic 1
  

•      - "MANCH_F": manchester codec, rising edge = logic 1, falling edge = logic 0
  

•    items:
  

•      enum: [ SPI_R, SPI_F, MANCH_R, MANCH_F ]
  

•    $ref: /schemas/types.yaml#/definitions/non-unique-string-array
  

•  st,adc-channel-clk-src:
  

•    description: |
  

•      Conversion clock source.
  

•      - "CLKIN": external SPI clock (CLKIN x)
  

•      - "CLKOUT": internal SPI clock (CLKOUT) (default)
  

•      - "CLKOUT_F": internal SPI clock divided by 2 (falling edge).
  

•      - "CLKOUT_R": internal SPI clock divided by 2 (rising edge).
  

•    items:
  

•      enum: [ CLKIN, CLKOUT, CLKOUT_F, CLKOUT_R ]
  

•    $ref: /schemas/types.yaml#/definitions/non-unique-string-array
  

•  st,adc-alt-channel:
  

•    description:
  

•      Must be defined if two sigma delta modulators are
  

•      connected on same SPI input.
  

•      If not set, channel n is connected to SPI input n.
  

•      If set, channel n is connected to SPI input n + 1.
  

•    type: boolean
  

•   st,filter0-sync:
      description:
        Set to 1 to synchronize with DFSDM filter instance 0.
  

@@ -157,14 +116,68 @@ patternProperties: items: - const: rx

• patternProperties:

•  "^channel@([0-9]|1[0-9])$":
  

•    type: object
  

•    $ref: "adc.yaml"
  

•    description: Represents the external channels which are connected to the DFSDM.
  

•    properties:
  

•      reg:
  

•        items:
  

•          minimum: 0
  

•          maximum: 19
  

•      label:
  

•        description: |
  

•          Unique name to identify channel.
  

•      st,adc-channel-types:
  

•        description: |
  

•          Single-ended channel input type.
  

•          - "SPI_R": SPI with data on rising edge (default)
  

•          - "SPI_F": SPI with data on falling edge
  

•          - "MANCH_R": manchester codec, rising edge = logic 0, falling edge = logic 1
  

•          - "MANCH_F": manchester codec, rising edge = logic 1, falling edge = logic 0
  

•        items:
  

•          enum: [ SPI_R, SPI_F, MANCH_R, MANCH_F ]
  

•        $ref: /schemas/types.yaml#/definitions/non-unique-string-array
  

•      st,adc-channel-clk-src:
  

•        description: |
  

•          Conversion clock source.
  

•          - "CLKIN": external SPI clock (CLKIN x)
  

•          - "CLKOUT": internal SPI clock (CLKOUT) (default)
  

•          - "CLKOUT_F": internal SPI clock divided by 2 (falling edge).
  

•          - "CLKOUT_R": internal SPI clock divided by 2 (rising edge).
  

•        items:
  

•          enum: [ CLKIN, CLKOUT, CLKOUT_F, CLKOUT_R ]
  

•        $ref: /schemas/types.yaml#/definitions/non-unique-string-array
  

•      st,adc-alt-channel:
  

•        description:
  

•          Must be defined if two sigma delta modulators are
  

•          connected on same SPI input.
  

•          If not set, channel n is connected to SPI input n.
  

•          If set, channel n is connected to SPI input n + 1.
  

•        type: boolean
  

•      io-backends:
  

•        description: |
  

•          phandle to an external sigma delta modulator or internal ADC output.
  

•        $ref: /schemas/types.yaml#/definitions/phandle
  

•    required:
  

•      - reg
  

•      - io-backends
  

•    additionalProperties: false
  

• required:
    - compatible
    - reg
    - interrupts
  

•  - st,adc-channels
  

•  - st,adc-channel-names
    - st,filter-order
  

•  - "#io-channel-cells"
  
  allOf:
    - if:
  

@@ -175,14 +188,6 @@ patternProperties:

      then:
        properties:

•        st,adc-channels:
  

•          minItems: 1
  

•          maxItems: 8
  

•        st,adc-channel-names:
  

•          minItems: 1
  

•          maxItems: 8
  

•         st,adc-channel-types:
            minItems: 1
            maxItems: 8
  

@@ -191,14 +196,6 @@ patternProperties: minItems: 1 maxItems: 8

•        io-channels:
  

•          description:
  

•            From common IIO binding. Used to pipe external sigma delta
  

•            modulator or internal ADC output to DFSDM channel.
  

•      required:
  

•        - io-channels
  

•   - if:
        properties:
          compatible:
  

@@ -207,12 +204,6 @@ patternProperties:

      then:
        properties:

•        st,adc-channels:
  

•          maxItems: 1
  

•        st,adc-channel-names:
  

•          maxItems: 1
  

•         st,adc-channel-types:
            maxItems: 1
  
  

@@ -237,15 +228,9 @@ patternProperties: "#sound-dai-cells": const: 0

•            io-channels:
  

•              description:
  

•                From common IIO binding. Used to pipe external sigma delta
  

•                modulator or internal ADC output to DFSDM channel.
  

•           required:
              - compatible
              - "#sound-dai-cells"
  

•            - io-channels
  
  

  allOf:

  • if:

@@ -278,52 +263,4 @@ allOf: minimum: 0 maximum: 5

-examples:

• • |
• #include <dt-bindings/interrupt-controller/arm-gic.h>
• #include <dt-bindings/clock/stm32mp1-clks.h>
• dfsdm: dfsdm@4400d000 {

•  compatible = "st,stm32mp1-dfsdm";
  

•  reg = <0x4400d000 0x800>;
  

•  clocks = <&rcc DFSDM_K>, <&rcc ADFSDM_K>;
  

•  clock-names = "dfsdm", "audio";
  

•  #address-cells = <1>;
  

•  #size-cells = <0>;
  

•  dfsdm0: filter@0 {
  

•    compatible = "st,stm32-dfsdm-dmic";
  

•    reg = <0>;
  

•    interrupts = <GIC_SPI 110 IRQ_TYPE_LEVEL_HIGH>;
  

•    dmas = <&dmamux1 101 0x400 0x01>;
  

•    dma-names = "rx";
  

•    #io-channel-cells = <1>;
  

•    st,adc-channels = <1>;
  

•    st,adc-channel-names = "dmic0";
  

•    st,adc-channel-types = "SPI_R";
  

•    st,adc-channel-clk-src = "CLKOUT";
  

•    st,filter-order = <5>;
  

•    asoc_pdm0: dfsdm-dai {
  

•      compatible = "st,stm32h7-dfsdm-dai";
  

•      #sound-dai-cells = <0>;
  

•      io-channels = <&dfsdm0 0>;
  

•    };
  

•  };
  

•  dfsdm_pdm1: filter@1 {
  

•    compatible = "st,stm32-dfsdm-adc";
  

•    reg = <1>;
  

•    interrupts = <GIC_SPI 111 IRQ_TYPE_LEVEL_HIGH>;
  

•    dmas = <&dmamux1 102 0x400 0x01>;
  

•    dma-names = "rx";
  

•    #io-channel-cells = <1>;
  

•    st,adc-channels = <2 3>;
  

•    st,adc-channel-names = "in2", "in3";
  

•    st,adc-channel-types = "SPI_R", "SPI_R";
  

•    st,adc-channel-clk-src = "CLKOUT_F", "CLKOUT_F";
  

•    io-channels = <&sd_adc2 &sd_adc3>;
  

•    st,filter-order = <1>;
  

•  };
  

• };
• ...

-- 2.25.1