# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
# Copyright 2023 Analog Devices Inc.
%YAML 1.2
---
$id: http://devicetree.org/schemas/iio/adc/adi,ad7173.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: Analog Devices AD7173 ADC
maintainers:
- Ceclan Dumitru <[email protected]>
description: |
Analog Devices AD717x ADC's:
The AD717x family offer a complete integrated Sigma-Delta ADC solution which
can be used in high precision, low noise single channel applications
(Life Science measurements) or higher speed multiplexed applications
(Factory Automation PLC Input modules). The Sigma-Delta ADC is intended
primarily for measurement of signals close to DC but also delivers
outstanding performance with input bandwidths out to ~10kHz.
Analog Devices AD411x ADC's:
The AD411X family encompasses a series of low power, low noise, 24-bit,
sigma-delta analog-to-digital converters that offer a versatile range of
specifications. They integrate an analog front end suitable for processing
fully differential/single-ended and bipolar voltage inputs.
Datasheets for supported chips:
https://www.analog.com/media/en/technical-documentation/data-sheets/AD4111.pdf
https://www.analog.com/media/en/technical-documentation/data-sheets/AD4112.pdf
https://www.analog.com/media/en/technical-documentation/data-sheets/AD4114.pdf
https://www.analog.com/media/en/technical-documentation/data-sheets/AD4115.pdf
https://www.analog.com/media/en/technical-documentation/data-sheets/AD4116.pdf
https://www.analog.com/media/en/technical-documentation/data-sheets/AD7172-2.pdf
https://www.analog.com/media/en/technical-documentation/data-sheets/AD7172-4.pdf
https://www.analog.com/media/en/technical-documentation/data-sheets/AD7173-8.pdf
https://www.analog.com/media/en/technical-documentation/data-sheets/AD7175-2.pdf
https://www.analog.com/media/en/technical-documentation/data-sheets/AD7175-8.pdf
https://www.analog.com/media/en/technical-documentation/data-sheets/AD7176-2.pdf
https://www.analog.com/media/en/technical-documentation/data-sheets/AD7177-2.pdf
properties:
compatible:
enum:
- adi,ad4111
- adi,ad4112
- adi,ad4114
- adi,ad4115
- adi,ad4116
- adi,ad7172-2
- adi,ad7172-4
- adi,ad7173-8
- adi,ad7175-2
- adi,ad7175-8
- adi,ad7176-2
- adi,ad7177-2
reg:
maxItems: 1
interrupts:
minItems: 1
items:
- description: |
Ready: multiplexed with SPI data out. While SPI CS is low,
can be used to indicate the completion of a conversion.
- description: |
Error: The three error bits in the status register (ADC_ERROR, CRC_ERROR,
and REG_ERROR) are OR'ed, inverted, and mapped to the ERROR pin.
Therefore, the ERROR pin indicates that an error has occurred.
interrupt-names:
minItems: 1
items:
- const: rdy
- const: err
'#address-cells':
const: 1
'#size-cells':
const: 0
spi-max-frequency:
maximum: 20000000
gpio-controller:
description: Marks the device node as a GPIO controller.
'#gpio-cells':
const: 2
description:
The first cell is the GPIO number and the second cell specifies
GPIO flags, as defined in <dt-bindings/gpio/gpio.h>.
vref-supply:
description: |
Differential external reference supply used for conversion. The reference
voltage (Vref) specified here must be the voltage difference between the
REF+ and REF- pins: Vref = (REF+) - (REF-).
vref2-supply:
description: |
Differential external reference supply used for conversion. The reference
voltage (Vref2) specified here must be the voltage difference between the
REF2+ and REF2- pins: Vref2 = (REF2+) - (REF2-).
avdd-supply:
description: Avdd supply, can be used as reference for conversion.
This supply is referenced to AVSS, voltage specified here
represents (AVDD1 - AVSS).
avdd2-supply:
description: Avdd2 supply, used as the input to the internal voltage regulator.
This supply is referenced to AVSS, voltage specified here
represents (AVDD2 - AVSS).
iovdd-supply:
description: iovdd supply, used for the chip digital interface.
clocks:
maxItems: 1
description: |
Optional external clock source. Can include one clock source: external
clock or external crystal.
clock-names:
enum:
- ext-clk
- xtal
'#clock-cells':
const: 0
patternProperties:
"^channel@[0-9a-f]$":
type: object
$ref: adc.yaml
unevaluatedProperties: false
properties:
reg:
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.
Family AD411x supports a dedicated VINCOM voltage input.
To select it set the second channel to 16.
(VIN2, VINCOM) -> diff-channels = <2 16>
There are special values that can be selected besides the voltage
analog inputs:
21: REF+
22: REF−
Supported only by AD7172-2, AD7172-4, AD7175-2, AD7175-8, AD7177-2,
must be paired together and can be used to monitor the power supply
of the ADC:
19: ((AVDD1 − AVSS)/5)+
20: ((AVDD1 − AVSS)/5)−
items:
minimum: 0
maximum: 31
single-channel:
description: |
This property is used for defining a current channel or the positive
input of a voltage channel (single-ended or pseudo-differential).
Models AD4111 and AD4112 support current channels.
Example: (IIN2+, IIN2−) -> single-channel = <2>
To correctly configure a current channel set the "adi,current-channel"
property to true.
To configure a single-ended/pseudo-differential channel set the
"common-mode-channel" property to the desired negative voltage input.
When used as a voltage channel, special inputs are valid as well.
minimum: 0
maximum: 31
common-mode-channel:
description:
This property is used for defining the negative input of a
single-ended or pseudo-differential voltage channel.
Special inputs are valid as well.
minimum: 0
maximum: 31
adi,reference-select:
description: |
Select the reference source to use when converting on
the specific channel. Valid values are:
vref : REF+ /REF−
vref2 : REF2+ /REF2−
refout-avss: REFOUT/AVSS (Internal reference)
avdd : AVDD /AVSS
External reference ref2 only available on ad7173-8 and ad7172-4.
Internal reference refout-avss not available on ad7172-4.
If not specified, internal reference used (if available).
$ref: /schemas/types.yaml#/definitions/string
enum:
- vref
- vref2
- refout-avss
- avdd
default: refout-avss
adi,current-channel:
$ref: /schemas/types.yaml#/definitions/flag
description: |
Signal that the selected inputs are current channels.
Only available on AD4111 and AD4112.
required:
- reg
allOf:
- oneOf:
- required: [single-channel]
properties:
diff-channels: false
- required: [diff-channels]
properties:
single-channel: false
adi,current-channel: false
common-mode-channel: false
- if:
required: [common-mode-channel]
then:
properties:
adi,current-channel: false
required:
- compatible
- reg
allOf:
- $ref: /schemas/spi/spi-peripheral-props.yaml#
# Only ad7172-4, ad7173-8 and ad7175-8 support vref2
- if:
properties:
compatible:
not:
contains:
enum:
- adi,ad7172-4
- adi,ad7173-8
- adi,ad7175-8
then:
properties:
vref2-supply: false
patternProperties:
"^channel@[0-9a-f]$":
properties:
adi,reference-select:
enum:
- vref
- refout-avss
- avdd
- if:
properties:
compatible:
contains:
enum:
- adi,ad4114
- adi,ad4115
- adi,ad4116
- adi,ad7173-8
- adi,ad7175-8
then:
patternProperties:
"^channel@[0-9a-f]$":
properties:
reg:
maximum: 15
- if:
properties:
compatible:
contains:
enum:
- adi,ad7172-2
- adi,ad7175-2
- adi,ad7176-2
- adi,ad7177-2
then:
patternProperties:
"^channel@[0-9a-f]$":
properties:
reg:
maximum: 3
# Model ad7172-4 does not support internal reference
- if:
properties:
compatible:
contains:
const: adi,ad7172-4
then:
patternProperties:
"^channel@[0-9a-f]$":
properties:
reg:
maximum: 7
adi,reference-select:
enum:
- vref
- vref2
- avdd
required:
- adi,reference-select
- if:
properties:
compatible:
contains:
enum:
- adi,ad4111
- adi,ad4112
- adi,ad4114
- adi,ad4115
- adi,ad4116
then:
properties:
avdd2-supply: false
- if:
properties:
compatible:
not:
contains:
enum:
- adi,ad4111
- adi,ad4112
then:
patternProperties:
"^channel@[0-9a-f]$":
properties:
adi,current-channel: false
- if:
anyOf:
- required: [clock-names]
- required: [clocks]
then:
properties:
'#clock-cells': false
unevaluatedProperties: false
examples:
# Example AD7173-8 with external reference connected to REF+/REF-:
- |
#include <dt-bindings/gpio/gpio.h>
#include <dt-bindings/interrupt-controller/irq.h>
spi {
#address-cells = <1>;
#size-cells = <0>;
adc@0 {
compatible = "adi,ad7173-8";
reg = <0>;
#address-cells = <1>;
#size-cells = <0>;
interrupts = <25 IRQ_TYPE_EDGE_FALLING>;
interrupt-names = "rdy";
interrupt-parent = <&gpio>;
spi-max-frequency = <5000000>;
gpio-controller;
#gpio-cells = <2>;
#clock-cells = <0>;
vref-supply = <&dummy_regulator>;
channel@0 {
reg = <0>;
bipolar;
diff-channels = <0 1>;
adi,reference-select = "vref";
};
channel@1 {
reg = <1>;
diff-channels = <2 3>;
};
channel@2 {
reg = <2>;
bipolar;
diff-channels = <4 5>;
};
channel@3 {
reg = <3>;
bipolar;
diff-channels = <6 7>;
};
channel@4 {
reg = <4>;
diff-channels = <8 9>;
adi,reference-select = "avdd";
};
};
};
# Example AD4111 with current channel and single-ended channel:
- |
#include <dt-bindings/gpio/gpio.h>
#include <dt-bindings/interrupt-controller/irq.h>
spi {
#address-cells = <1>;
#size-cells = <0>;
adc@0 {
compatible = "adi,ad4111";
reg = <0>;
#address-cells = <1>;
#size-cells = <0>;
interrupts = <25 IRQ_TYPE_EDGE_FALLING>;
interrupt-names = "rdy";
interrupt-parent = <&gpio>;
spi-max-frequency = <5000000>;
gpio-controller;
#gpio-cells = <2>;
#clock-cells = <0>;
channel@0 {
reg = <0>;
bipolar;
diff-channels = <4 5>;
};
// Single ended channel VIN2/VINCOM
channel@1 {
reg = <1>;
bipolar;
single-channel = <2>;
common-mode-channel = <16>;
};
// Current channel IN2+/IN2-
channel@2 {
reg = <2>;
single-channel = <2>;
adi,current-channel;
};
};
};
Codebase Browser
linux