dt-bindings: stm32: convert dfsdm to json-schema

STMicroelectronics STM32 DFSDM ADC device driver

STM32 DFSDM ADC is a sigma delta analog-to-digital converter dedicated to

interface external sigma delta modulators to STM32 micro controllers.

It is mainly targeted for:

- Sigma delta modulators (motor control, metering...)

- PDM microphones (audio digital microphone)

It features up to 8 serial digital interfaces (SPI or Manchester) and

up to 4 filters on stm32h7 or 6 filters on stm32mp1.

Each child node match with a filter instance.

Contents of a STM32 DFSDM root node:

------------------------------------

Required properties:

- compatible: Should be one of:

  "st,stm32h7-dfsdm"

  "st,stm32mp1-dfsdm"

- reg: Offset and length of the DFSDM block register set.

- clocks: IP and serial interfaces clocking. Should be set according

		to rcc clock ID and "clock-names".

- clock-names: Input clock name "dfsdm" must be defined,

		"audio" is optional. If defined CLKOUT is based on the audio

		clock, else "dfsdm" is used.

- #interrupt-cells = <1>;

- #address-cells = <1>;

- #size-cells = <0>;

Optional properties:

- spi-max-frequency: Requested only for SPI master mode.

		  SPI clock OUT frequency (Hz). This clock must be set according

		  to "clock" property. Frequency must be a multiple of the rcc

		  clock frequency. If not, SPI CLKOUT frequency will not be

		  accurate.

- pinctrl-names:	Set to "default".

- pinctrl-0:		List of phandles pointing to pin configuration

			nodes to set pins in mode of operation for dfsdm

			on external pin.

Contents of a STM32 DFSDM child nodes:

--------------------------------------

Required properties:

- compatible: Must be:

	"st,stm32-dfsdm-adc" for sigma delta ADCs

	"st,stm32-dfsdm-dmic" for audio digital microphone.

- reg: Specifies the DFSDM filter instance used.

	Valid values are from 0 to 3 on stm32h7, 0 to 5 on stm32mp1.

- interrupts: IRQ lines connected to each DFSDM filter instance.

- st,adc-channels:	List of single-ended channels muxed for this ADC.

			valid values:

				"st,stm32h7-dfsdm" compatibility: 0 to 7.

- st,adc-channel-names:	List of single-ended channel names.

- st,filter-order:  SinC filter order from 0 to 5.

			0: FastSinC

			[1-5]: order 1 to 5.

			For audio purpose it is recommended to use order 3 to 5.

- #io-channel-cells = <1>: See the IIO bindings section "IIO consumers".

Required properties for "st,stm32-dfsdm-adc" compatibility:

- io-channels: From common IIO binding. Used to pipe external sigma delta

		modulator or internal ADC output to DFSDM channel.

		This is not required for "st,stm32-dfsdm-pdm" compatibility as

		PDM microphone is binded in Audio DT node.

Required properties for "st,stm32-dfsdm-pdm" compatibility:

- #sound-dai-cells: Must be set to 0.

- dma: DMA controller phandle and DMA request line associated to the

		filter instance (specified by the field "reg")

- dma-names: Must be "rx"

Optional properties:

- st,adc-channel-types:	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

- st,adc-channel-clk-src: 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).

- st,adc-alt-channel: Must be defined if two sigma delta modulator 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.

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

		   Used for multi microphones synchronization.

Example of a sigma delta adc connected on DFSDM SPI port 0

and a pdm microphone connected on DFSDM SPI port 1:

	ads1202: simple_sd_adc@0 {

		compatible = "ads1202";

		#io-channel-cells = <1>;

	};

	dfsdm: dfsdm@40017000 {

		compatible = "st,stm32h7-dfsdm";

		reg = <0x40017000 0x400>;

		clocks = <&rcc DFSDM1_CK>;

		clock-names = "dfsdm";

		#interrupt-cells = <1>;

		#address-cells = <1>;

		#size-cells = <0>;

		dfsdm_adc0: filter@0 {

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

			#io-channel-cells = <1>;

			reg = <0>;

			interrupts = <110>;

			st,adc-channels = <0>;

			st,adc-channel-names = "sd_adc0";

			st,adc-channel-types = "SPI_F";

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

			io-channels = <&ads1202 0>;

			st,filter-order = <3>;

		};

		dfsdm_pdm1: filter@1 {

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

			reg = <1>;

			interrupts = <111>;

			dmas = <&dmamux1 102 0x400 0x00>;

			dma-names = "rx";

			st,adc-channels = <1>;

			st,adc-channel-names = "dmic1";

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

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

			st,filter-order = <5>;

		};

	}

# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)

%YAML 1.2

---

$id: http://devicetree.org/schemas/st,stm32-dfsdm-adc.yaml#

$schema: http://devicetree.org/meta-schemas/core.yaml#

title: STMicroelectronics STM32 DFSDM ADC device driver

maintainers:

  - Fabrice Gasnier <fabrice.gasnier@st.com>

  - Olivier Moysan <olivier.moysan@st.com>

description: |

  STM32 DFSDM ADC is a sigma delta analog-to-digital converter dedicated to

  interface external sigma delta modulators to STM32 micro controllers.

  It is mainly targeted for:

  - Sigma delta modulators (motor control, metering...)

  - PDM microphones (audio digital microphone)

  It features up to 8 serial digital interfaces (SPI or Manchester) and

  up to 4 filters on stm32h7 or 6 filters on stm32mp1.

  Each child node matches with a filter instance.

properties:

  compatible:

    enum:

      - st,stm32h7-dfsdm

      - st,stm32mp1-dfsdm

  reg:

    maxItems: 1

  clocks:

    items:

      - description:

          Internal clock used for DFSDM digital processing and control blocks.

          dfsdm clock can also feed CLKOUT, when CLKOUT is used.

      - description: audio clock can be used as an alternate to feed CLKOUT.

    minItems: 1

    maxItems: 2

  clock-names:

    items:

      - const: dfsdm

      - const: audio

    minItems: 1

    maxItems: 2

  "#address-cells":

    const: 1

  "#size-cells":

    const: 0

  spi-max-frequency:

    description:

      SPI clock OUT frequency (Hz). Requested only for SPI master mode.

      This clock must be set according to the "clock" property.

      Frequency must be a multiple of the rcc clock frequency.

      If not, SPI CLKOUT frequency will not be accurate.

    maximum: 20000000

required:

  - compatible

  - reg

  - clocks

  - clock-names

  - "#address-cells"

  - "#size-cells"

patternProperties:

  "^filter@[0-9]+$":

    type: object

    description: child node

    properties:

      compatible:

        enum:

          - st,stm32-dfsdm-adc

          - st,stm32-dfsdm-dmic

      reg:

        description: Specifies the DFSDM filter instance used.

        maxItems: 1

      interrupts:

        maxItems: 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.

        allOf:

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

          - items:

              minimum: 0

              maximum: 7

      st,adc-channel-names:

        description: List of single-ended channel names.

        allOf:

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

      st,filter-order:

        description: |

          SinC filter order from 0 to 5.

          - 0: FastSinC

          - [1-5]: order 1 to 5.

          For audio purpose it is recommended to use order 3 to 5.

        allOf:

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

          - items:

              minimum: 0

              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 ]

        allOf:

          - $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 ]

        allOf:

          - $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.

          Used for multi microphones synchronization.

        type: boolean

      dmas:

        maxItems: 1

      dma-names:

        items:

          - const: rx

    required:

      - compatible

      - reg

      - interrupts

      - st,adc-channels

      - st,adc-channel-names

      - st,filter-order

      - "#io-channel-cells"

    allOf:

      - if:

          properties:

            compatible:

              contains:

                const: st,stm32-dfsdm-adc

      - 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

            st,adc-channel-clk-src:

              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.

                This is not required for "st,stm32-dfsdm-pdm" compatibility as

                PDM microphone is binded in Audio DT node.

          required:

            - io-channels

      - if:

          properties:

            compatible:

              contains:

                const: st,stm32-dfsdm-dmic

      - then:

          properties:

            st,adc-channels:

              maxItems: 1

            st,adc-channel-names:

              maxItems: 1

            st,adc-channel-types:

              maxItems: 1

            st,adc-channel-clk-src:

              maxItems: 1

          required:

            - dmas

            - dma-names

          patternProperties:

            "^dfsdm-dai+$":

              type: object

              description: child node

              properties:

                "#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:

                - "#sound-dai-cells"

                - io-channels

allOf:

  - if:

      properties:

        compatible:

          contains:

            const: st,stm32h7-dfsdm

  - then:

      patternProperties:

        "^filter@[0-9]+$":

          properties:

            reg:

              items:

                minimum: 0

                maximum: 3

  - if:

      properties:

        compatible:

          contains:

            const: st,stm32mp1-dfsdm

  - then:

      patternProperties:

        "^filter@[0-9]+$":

          properties:

            reg:

              items:

                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>;

      };

    };

...