# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) %YAML 1.2 --- $id: http://devicetree.org/schemas/iio/adc/st,stm32-dfsdm-adc.yaml# $schema: http://devicetree.org/meta-schemas/core.yaml# title: STMicroelectronics STM32 DFSDM ADC device driver maintainers: - Fabrice Gasnier - Olivier Moysan description: | STM32 DFSDM ADC is a sigma delta analog-to-digital converter dedicated to interface external sigma delta modulators to STM32 micro controllers. It is mainly targeted for: - Sigma delta modulators (motor control, metering...) - PDM microphones (audio digital microphone) It features up to 8 serial digital interfaces (SPI or Manchester) and up to 4 filters on stm32h7 or 6 filters on stm32mp1. Each child node matches with a filter instance. properties: compatible: enum: - st,stm32h7-dfsdm - st,stm32mp1-dfsdm reg: maxItems: 1 clocks: items: - description: Internal clock used for DFSDM digital processing and control blocks. dfsdm clock can also feed CLKOUT, when CLKOUT is used. - description: audio clock can be used as an alternate to feed CLKOUT. minItems: 1 clock-names: items: - const: dfsdm - const: audio minItems: 1 "#address-cells": const: 1 "#size-cells": const: 0 spi-max-frequency: description: SPI clock OUT frequency (Hz). Requested only for SPI master mode. This clock must be set according to the "clock" property. Frequency must be a multiple of the rcc clock frequency. If not, SPI CLKOUT frequency will not be accurate. maximum: 20000000 required: - compatible - reg - clocks - clock-names - "#address-cells" - "#size-cells" additionalProperties: false patternProperties: "^filter@[0-9]+$": type: object unevaluatedProperties: false 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. $ref: /schemas/types.yaml#/definitions/uint32-array items: minimum: 0 maximum: 7 st,adc-channel-names: description: List of single-ended channel names. 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. $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 ] $ref: /schemas/types.yaml#/definitions/non-unique-string-array st,adc-alt-channel: description: Must be defined if two sigma delta modulators are connected on same SPI input. If not set, channel n is connected to SPI input n. If set, channel n is connected to SPI input n + 1. type: boolean st,filter0-sync: description: Set to 1 to synchronize with DFSDM filter instance 0. Used for multi microphones synchronization. type: boolean dmas: maxItems: 1 dma-names: items: - const: rx required: - compatible - reg - interrupts - st,adc-channels - st,adc-channel-names - st,filter-order - "#io-channel-cells" allOf: - if: properties: compatible: contains: const: st,stm32-dfsdm-adc then: properties: st,adc-channels: minItems: 1 maxItems: 8 st,adc-channel-names: minItems: 1 maxItems: 8 st,adc-channel-types: minItems: 1 maxItems: 8 st,adc-channel-clk-src: minItems: 1 maxItems: 8 io-channels: description: From common IIO binding. Used to pipe external sigma delta modulator or internal ADC output to DFSDM channel. required: - io-channels - if: properties: compatible: contains: const: st,stm32-dfsdm-dmic then: properties: st,adc-channels: maxItems: 1 st,adc-channel-names: maxItems: 1 st,adc-channel-types: maxItems: 1 st,adc-channel-clk-src: maxItems: 1 required: - dmas - dma-names patternProperties: "^dfsdm-dai+$": type: object additionalProperties: false description: child node properties: compatible: enum: - st,stm32h7-dfsdm-dai "#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: 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 #include 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 = ; 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 = ; 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>; }; }; ...