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diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ad4170-4.yaml b/Documentation/devicetree/bindings/iio/adc/adi,ad4170-4.yaml new file mode 100644 index 000000000000..da93213d12d4 --- /dev/null +++ b/Documentation/devicetree/bindings/iio/adc/adi,ad4170-4.yaml @@ -0,0 +1,554 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/iio/adc/adi,ad4170-4.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Analog Devices AD4170-4 and similar Analog to Digital Converters + +maintainers: + - Marcelo Schmitt <marcelo.schmitt@analog.com> + +description: | + Analog Devices AD4170-4 series of Sigma-delta Analog to Digital Converters. + Specifications can be found at: + https://www.analog.com/media/en/technical-documentation/data-sheets/ad4170-4.pdf + https://www.analog.com/media/en/technical-documentation/data-sheets/ad4190-4.pdf + https://www.analog.com/media/en/technical-documentation/data-sheets/ad4195-4.pdf + +$ref: /schemas/spi/spi-peripheral-props.yaml# + +$defs: + reference-buffer: + description: | + Enable precharge buffer, full buffer, or skip reference buffering of + the positive/negative voltage reference. Because the output impedance + of the source driving the voltage reference inputs may be dynamic, + resistive/capacitive combinations of those inputs can cause DC gain + errors if the reference inputs go unbuffered into the ADC. Enable + reference buffering if the provided reference source has dynamic high + impedance output. Note the absolute voltage allowed on REFINn+ and REFINn- + inputs is from AVSS - 50 mV to AVDD + 50 mV when the reference buffers are + disabled but narrows to AVSS to AVDD when reference buffering is enabled + or in precharge mode. + $ref: /schemas/types.yaml#/definitions/string + enum: [ precharge, full, disabled ] + default: full + +properties: + compatible: + enum: + - adi,ad4170-4 + - adi,ad4190-4 + - adi,ad4195-4 + + avss-supply: + description: + Reference voltage supply for AVSS. A −2.625V minimum and 0V maximum supply + that powers the chip. If not provided, AVSS is assumed to be at system + ground (0V). + + avdd-supply: + description: + A supply of 4.75V to 5.25V relative to AVSS that powers the chip (AVDD). + + iovdd-supply: + description: 1.7V to 5.25V reference supply to the serial interface (IOVDD). + + refin1p-supply: + description: REFIN+ supply that can be used as reference for conversion. + + refin1n-supply: + description: REFIN- supply that can be used as reference for conversion. + + refin2p-supply: + description: REFIN2+ supply that can be used as reference for conversion. + + refin2n-supply: + description: REFIN2- supply that can be used as reference for conversion. + + spi-cpol: true + + spi-cpha: true + + interrupts: + description: + Interrupt for signaling the completion of conversion results. The data + ready signal (RDY) used as interrupt is by default provided on the SDO + pin. Alternatively, it can be provided on the DIG_AUX1 pin in which case + the chip disables the RDY function on SDO. Thus, there can be only one + data ready interrupt enabled at a time. + + interrupt-names: + description: + Specify which pin should be configured as Data Ready interrupt. + enum: + - sdo + - dig_aux1 + + clocks: + maxItems: 1 + description: + Optional external clock source. Can specify either an external clock or + external crystal. + + clock-names: + enum: + - ext-clk + - xtal + default: ext-clk + + '#clock-cells': + const: 0 + + clock-output-names: + maxItems: 1 + + gpio-controller: true + + "#gpio-cells": + const: 2 + description: | + The first cell is for the GPIO number: 0 to 3. + The second cell takes standard GPIO flags. + + ldac-gpios: + description: + GPIO connected to DIG_AUX2 pin to be used as LDAC toggle to control the + transfer of data from the DAC_INPUT_A register to the DAC. + maxItems: 1 + + '#address-cells': + const: 1 + + '#size-cells': + const: 0 + + adi,vbias-pins: + description: Analog inputs to apply a voltage bias of (AVDD − AVSS) / 2 to. + $ref: /schemas/types.yaml#/definitions/uint32-array + minItems: 1 + maxItems: 9 + items: + minimum: 0 + maximum: 8 + +allOf: + # Some devices don't have integrated DAC + - if: + properties: + compatible: + contains: + enum: + - adi,ad4190-4 + - adi,ad4195-4 + then: + properties: + ldac-gpios: false + + # Require to specify the interrupt pin when using interrupts + - if: + required: + - interrupts + then: + required: + - interrupt-names + + # If an external clock is set, the internal clock cannot go out and vice versa + - oneOf: + - required: [clocks] + properties: + '#clock-cells': false + - required: ['#clock-cells'] + properties: + clocks: false + +required: + - compatible + - reg + - avdd-supply + - iovdd-supply + - spi-cpol + - spi-cpha + +unevaluatedProperties: false + +patternProperties: + "^channel@[0-9a-f]$": + $ref: /schemas/iio/adc/adc.yaml# + unevaluatedProperties: false + description: + Represents the external channels which are connected to the ADC. + + properties: + reg: + description: + The channel number. + minimum: 0 + maximum: 15 + + diff-channels: + description: | + This property is used for defining the inputs of a differential + voltage channel. The first value is the positive input and the second + value is the negative input of the channel. + + Besides the analog input pins AIN0 to AIN8, there are special inputs + that can be selected with the following values: + 17: Internal temperature sensor + 18: (AVDD-AVSS)/5 + 19: (IOVDD-DGND)/5 + 20: DAC output + 21: ALDO + 22: DLDO + 23: AVSS + 24: DGND + 25: REFIN+ + 26: REFIN- + 27: REFIN2+ + 28: REFIN2- + 29: REFOUT + For the internal temperature sensor, use the input number for both + inputs (i.e. diff-channels = <17 17>). + items: + enum: [0, 1, 2, 3, 4, 5, 6, 7, 8, 17, 18, 19, 20, 21, 22, 23, 24, 25, + 26, 27, 28, 29] + + adi,reference-select: + description: | + Select the reference source to use when converting on the + specific channel. Valid values are: + 0: REFIN+/REFIN- + 1: REFIN2+/REFIN2− + 2: REFOUT/AVSS (internal reference) + 3: AVDD/AVSS + If not specified, REFOUT/AVSS is used. + $ref: /schemas/types.yaml#/definitions/uint32 + enum: [0, 1, 2, 3] + default: 1 + + adi,positive-reference-buffer: + $ref: '#/$defs/reference-buffer' + + adi,negative-reference-buffer: + $ref: '#/$defs/reference-buffer' + + adi,sensor-type: + description: + The AD4170-4 and similar designs have features to aid interfacing with + load cell weigh scale, RTD, and thermocouple sensors. Each of those + sensor types requires either distinct wiring configuration or + external circuitry for proper sensor operation and can use different + ADC chip functionality on their setups. A key characteristic of those + external sensors is that they must be excited either by voltage supply + or by ADC chip excitation signals. The sensor can then be read through + a pair of analog inputs. This property specifies which particular + sensor type is connected to the ADC so it can be properly setup and + handled. Omit this property for conventional (not weigh scale, RTD, or + thermocouple) ADC channel setups. + $ref: /schemas/types.yaml#/definitions/string + enum: [ weighscale, rtd, thermocouple ] + + adi,excitation-pin-0: + description: + Analog input to apply excitation current to while the channel + is active. + $ref: /schemas/types.yaml#/definitions/uint32 + minimum: 0 + maximum: 20 + default: 0 + + adi,excitation-pin-1: + description: + Analog input to apply excitation current to while the channel + is active. + $ref: /schemas/types.yaml#/definitions/uint32 + minimum: 0 + maximum: 20 + default: 0 + + adi,excitation-pin-2: + description: + Analog input to apply excitation current to while the channel + is active. + $ref: /schemas/types.yaml#/definitions/uint32 + minimum: 0 + maximum: 20 + default: 0 + + adi,excitation-pin-3: + description: + Analog input to apply excitation current to while the channel + is active. + $ref: /schemas/types.yaml#/definitions/uint32 + minimum: 0 + maximum: 20 + default: 0 + + adi,excitation-current-0-microamp: + description: + Excitation current in microamperes to be applied to pin specified in + adi,excitation-pin-0 while this channel is active. + enum: [0, 10, 50, 100, 250, 500, 1000, 1500] + default: 0 + + adi,excitation-current-1-microamp: + description: + Excitation current in microamperes to be applied to pin specified in + adi,excitation-pin-1 while this channel is active. + enum: [0, 10, 50, 100, 250, 500, 1000, 1500] + default: 0 + + adi,excitation-current-2-microamp: + description: + Excitation current in microamperes to be applied to pin specified in + adi,excitation-pin-2 while this channel is active. + enum: [0, 10, 50, 100, 250, 500, 1000, 1500] + default: 0 + + adi,excitation-current-3-microamp: + description: + Excitation current in microamperes to be applied to pin specified in + adi,excitation-pin-3 while this channel is active. + enum: [0, 10, 50, 100, 250, 500, 1000, 1500] + default: 0 + + adi,excitation-ac: + type: boolean + description: + Whether the external sensor has to be AC or DC excited. When omitted, + it is DC excited. + + allOf: + - oneOf: + - required: [single-channel, common-mode-channel] + properties: + diff-channels: false + - required: [diff-channels] + properties: + single-channel: false + common-mode-channel: false + # Usual ADC channels don't need external circuitry excitation. + - if: + not: + required: + - adi,sensor-type + then: + properties: + adi,excitation-pin-0: false + adi,excitation-pin-1: false + adi,excitation-pin-2: false + adi,excitation-pin-3: false + adi,excitation-current-0-microamp: false + adi,excitation-current-1-microamp: false + adi,excitation-current-2-microamp: false + adi,excitation-current-3-microamp: false + adi,excitation-ac: false + # Weigh scale bridge AC excited with one pair of predefined signals. + - if: + allOf: + - properties: + adi,sensor-type: + contains: + const: weighscale + - required: + - adi,excitation-ac + - adi,excitation-pin-2 + - adi,excitation-pin-3 + - not: + required: + - adi,excitation-current-2-microamp + - adi,excitation-current-3-microamp + then: + properties: + adi,excitation-pin-2: + const: 19 + adi,excitation-pin-3: + const: 20 + # Weigh scale bridge AC excited with two pairs of predefined signals. + - if: + allOf: + - properties: + adi,sensor-type: + contains: + const: weighscale + - required: + - adi,excitation-ac + - adi,excitation-pin-0 + - adi,excitation-pin-1 + - adi,excitation-pin-2 + - adi,excitation-pin-3 + - not: + required: + - adi,excitation-current-0-microamp + - adi,excitation-current-1-microamp + - adi,excitation-current-2-microamp + - adi,excitation-current-3-microamp + then: + properties: + adi,excitation-pin-0: + const: 17 + adi,excitation-pin-1: + const: 18 + adi,excitation-pin-2: + const: 19 + adi,excitation-pin-3: + const: 20 + +examples: + - | + #include <dt-bindings/interrupt-controller/irq.h> + spi { + #address-cells = <1>; + #size-cells = <0>; + + adc@0 { + compatible = "adi,ad4170-4"; + reg = <0>; + spi-max-frequency = <20000000>; + spi-cpol; + spi-cpha; + avdd-supply = <&avdd>; + iovdd-supply = <&iovdd>; + clocks = <&clk>; + clock-names = "xtal"; + interrupts = <0 IRQ_TYPE_EDGE_FALLING>; + interrupt-names = "dig_aux1"; + adi,vbias-pins = <8>; + #address-cells = <1>; + #size-cells = <0>; + + // Sample AIN0 with respect to DGND throughout AVDD/DGND input range + // Pseudo-differential unipolar + channel@0 { + reg = <0>; + single-channel = <0>; + common-mode-channel = <24>; + adi,reference-select = <3>; + }; + // Weigh scale sensor + channel@1 { + reg = <1>; + bipolar; + diff-channels = <1 2>; + adi,reference-select = <0>; + adi,positive-reference-buffer = "precharge"; + adi,negative-reference-buffer = "precharge"; + adi,sensor-type = "weighscale"; + adi,excitation-pin-2 = <19>; + adi,excitation-pin-3 = <20>; + adi,excitation-ac; + }; + // RTD sensor + channel@2 { + reg = <2>; + bipolar; + diff-channels = <3 4>; + adi,reference-select = <0>; + adi,sensor-type = "rtd"; + adi,excitation-pin-0 = <5>; + adi,excitation-pin-1 = <6>; + adi,excitation-current-0-microamp = <500>; + adi,excitation-current-1-microamp = <500>; + adi,excitation-ac; + }; + // Thermocouple sensor + channel@3 { + reg = <3>; + bipolar; + diff-channels = <7 8>; + adi,reference-select = <0>; + adi,sensor-type = "thermocouple"; + adi,excitation-pin-0 = <18>; + adi,excitation-current-0-microamp = <500>; + }; + }; + }; + - | + #include <dt-bindings/interrupt-controller/irq.h> + spi { + #address-cells = <1>; + #size-cells = <0>; + + adc@0 { + compatible = "adi,ad4170-4"; + reg = <0>; + spi-max-frequency = <20000000>; + spi-cpol; + spi-cpha; + avdd-supply = <&avdd>; + iovdd-supply = <&iovdd>; + #clock-cells = <0>; + clock-output-names = "ad4170-clk16mhz"; + interrupts = <0 IRQ_TYPE_EDGE_FALLING>; + interrupt-names = "dig_aux1"; + #address-cells = <1>; + #size-cells = <0>; + + // Sample AIN0 with respect to AIN1 throughout AVDD/AVSS input range + // Differential bipolar. If AVSS < 0V, differential true bipolar + channel@0 { + reg = <0>; + bipolar; + diff-channels = <0 1>; + adi,reference-select = <3>; + }; + // Sample AIN2 with respect to DGND throughout AVDD/DGND input range + // Pseudo-differential unipolar + channel@1 { + reg = <1>; + single-channel = <2>; + common-mode-channel = <24>; + adi,reference-select = <3>; + }; + // Sample AIN3 with respect to 2.5V throughout AVDD/AVSS input range + // Pseudo-differential bipolar + channel@2 { + reg = <2>; + bipolar; + single-channel = <3>; + common-mode-channel = <29>; + adi,reference-select = <3>; + }; + // Sample AIN4 with respect to DGND throughout AVDD/AVSS input range + // Pseudo-differential bipolar + channel@3 { + reg = <3>; + bipolar; + single-channel = <4>; + common-mode-channel = <24>; + adi,reference-select = <3>; + }; + // Sample AIN5 with respect to 2.5V throughout AVDD/AVSS input range + // Pseudo-differential unipolar (AD4170-4 datasheet page 46 example) + channel@4 { + reg = <4>; + single-channel = <5>; + common-mode-channel = <29>; + adi,reference-select = <3>; + }; + // Sample AIN6 with respect to 2.5V throughout REFIN+/REFIN- input range + // Pseudo-differential bipolar + channel@5 { + reg = <5>; + bipolar; + single-channel = <6>; + common-mode-channel = <29>; + adi,reference-select = <0>; + }; + // Weigh scale sensor + channel@6 { + reg = <6>; + bipolar; + diff-channels = <7 8>; + adi,reference-select = <0>; + adi,sensor-type = "weighscale"; + adi,excitation-pin-0 = <17>; + adi,excitation-pin-1 = <18>; + adi,excitation-pin-2 = <19>; + adi,excitation-pin-3 = <20>; + adi,excitation-ac; + }; + }; + }; +... |