# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/iio/adc/st,stm32-adc.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: STMicroelectronics STM32 ADC
description: |
STM32 ADC is a successive approximation analog-to-digital converter.
It has several multiplexed input channels. Conversions can be performed
in single, continuous, scan or discontinuous mode. Result of the ADC is
stored in a left-aligned or right-aligned 32-bit data register.
Conversions can be launched in software or using hardware triggers.
The analog watchdog feature allows the application to detect if the input
voltage goes beyond the user-defined, higher or lower thresholds.
Each STM32 ADC block can have up to 3 ADC instances.
maintainers:
- Fabrice Gasnier <fabrice.gasnier@foss.st.com>
properties:
compatible:
enum:
- st,stm32f4-adc-core
- st,stm32h7-adc-core
- st,stm32mp1-adc-core
- st,stm32mp13-adc-core
reg:
maxItems: 1
interrupts:
description: |
One or more interrupts for ADC block, depending on part used:
- stm32f4 and stm32h7 share a common ADC interrupt line.
- stm32mp1 has two separate interrupt lines, one for each ADC within
ADC block.
- stm32mp13 has an interrupt line per ADC block.
minItems: 1
maxItems: 2
clocks:
minItems: 1
maxItems: 2
description: |
Core can use up to two clocks, depending on part used:
- "adc" clock: for the analog circuitry, common to all ADCs.
It's required on stm32f4.
It's optional on stm32h7 and stm32mp1.
- "bus" clock: for registers access, common to all ADCs.
It's not present on stm32f4.
It's required on stm32h7 and stm32mp1.
clock-names: true
st,max-clk-rate-hz:
description:
Allow to specify desired max clock rate used by analog circuitry.
vdda-supply:
description: Phandle to the vdda input analog voltage.
vref-supply:
description: Phandle to the vref input analog reference voltage.
booster-supply:
description:
Phandle to the embedded booster regulator that can be used to supply ADC
analog input switches on stm32h7 and stm32mp1.
vdd-supply:
description:
Phandle to the vdd input voltage. It can be used to supply ADC analog
input switches on stm32mp1.
st,syscfg:
description:
Phandle to system configuration controller. It can be used to control the
analog circuitry on stm32mp1.
$ref: /schemas/types.yaml#/definitions/phandle-array
interrupt-controller: true
'#interrupt-cells':
const: 1
'#address-cells':
const: 1
'#size-cells':
const: 0
allOf:
- if:
properties:
compatible:
contains:
const: st,stm32f4-adc-core
then:
properties:
clocks:
maxItems: 1
clock-names:
const: adc
interrupts:
items:
- description: interrupt line common for all ADCs
st,max-clk-rate-hz:
minimum: 600000
maximum: 36000000
default: 36000000
booster-supply: false
vdd-supply: false
st,syscfg: false
- if:
properties:
compatible:
contains:
const: st,stm32h7-adc-core
then:
properties:
clocks:
minItems: 1
maxItems: 2
clock-names:
items:
- const: bus
- const: adc
minItems: 1
interrupts:
items:
- description: interrupt line common for all ADCs
st,max-clk-rate-hz:
minimum: 120000
maximum: 36000000
default: 36000000
vdd-supply: false
st,syscfg: false
- if:
properties:
compatible:
contains:
const: st,stm32mp1-adc-core
then:
properties:
clocks:
minItems: 1
maxItems: 2
clock-names:
items:
- const: bus
- const: adc
minItems: 1
interrupts:
items:
- description: interrupt line for ADC1
- description: interrupt line for ADC2
st,max-clk-rate-hz:
minimum: 120000
maximum: 36000000
default: 36000000
- if:
properties:
compatible:
contains:
const: st,stm32mp13-adc-core
then:
properties:
clocks:
minItems: 1
maxItems: 2
clock-names:
items:
- const: bus
- const: adc
minItems: 1
interrupts:
items:
- description: ADC interrupt line
st,max-clk-rate-hz:
minimum: 150000
maximum: 75000000
default: 75000000
additionalProperties: false
required:
- compatible
- reg
- interrupts
- clocks
- clock-names
- vdda-supply
- vref-supply
- interrupt-controller
- '#interrupt-cells'
- '#address-cells'
- '#size-cells'
patternProperties:
"^adc@[0-9]+$":
type: object
description:
An ADC block node should contain at least one subnode, representing an
ADC instance available on the machine.
properties:
compatible:
enum:
- st,stm32f4-adc
- st,stm32h7-adc
- st,stm32mp1-adc
- st,stm32mp13-adc
reg:
description: |
Offset of ADC instance in ADC block. Valid values are:
- 0x0: ADC1
- 0x100: ADC2
- 0x200: ADC3 (stm32f4 only)
maxItems: 1
'#io-channel-cells':
const: 1
'#address-cells':
const: 1
'#size-cells':
const: 0
interrupts:
description: |
IRQ Line for the ADC instance. Valid values are:
- 0 for adc@0 (single adc for stm32mp13)
- 1 for adc@100
- 2 for adc@200 (stm32f4 only)
maxItems: 1
clocks:
description:
Input clock private to this ADC instance. It's required only on
stm32f4, that has per instance clock input for registers access.
maxItems: 1
dmas:
description: RX DMA Channel
maxItems: 1
dma-names:
const: rx
assigned-resolution-bits:
description: |
Resolution (bits) to use for conversions:
- can be 6, 8, 10 or 12 on stm32f4 and stm32mp13
- can be 8, 10, 12, 14 or 16 on stm32h7 and stm32mp1
st,adc-channels:
description: |
List of single-ended channels muxed for this ADC. It can have up to:
- 16 channels, numbered from 0 to 15 (for in0..in15) on stm32f4
- 19 channels, numbered from 0 to 18 (for in0..in18) on stm32mp13.
- 20 channels, numbered from 0 to 19 (for in0..in19) on stm32h7 and
stm32mp1.
$ref: /schemas/types.yaml#/definitions/uint32-array
deprecated: true
st,adc-diff-channels:
description: |
List of differential channels muxed for this ADC. Some channels can
be configured as differential instead of single-ended on stm32h7 and
on stm32mp1. Positive and negative inputs pairs are listed:
<vinp vinn>, <vinp vinn>,... vinp and vinn are numbered from 0 to 19.
Note: At least one of "st,adc-channels" or "st,adc-diff-channels" is
required if no adc generic channel is defined. These legacy channel
properties are exclusive with adc generic channel bindings.
Both properties can be used together. Some channels can be
used as single-ended and some other ones as differential (mixed). But
channels can't be configured both as single-ended and differential.
$ref: /schemas/types.yaml#/definitions/uint32-matrix
items:
items:
- description: |
"vinp" indicates positive input number
minimum: 0
maximum: 19
- description: |
"vinn" indicates negative input number
minimum: 0
maximum: 19
deprecated: true
st,min-sample-time-nsecs:
description:
Minimum sampling time in nanoseconds. Depending on hardware (board)
e.g. high/low analog input source impedance, fine tune of ADC
sampling time may be recommended. This can be either one value or an
array that matches "st,adc-channels" and/or "st,adc-diff-channels"
list, to set sample time resp. for all channels, or independently for
each channel.
$ref: /schemas/types.yaml#/definitions/uint32-array
deprecated: true
nvmem-cells:
items:
- description: Phandle to the calibration vrefint data provided by otp
nvmem-cell-names:
items:
- const: vrefint
patternProperties:
"^channel@([0-9]|1[0-9])$":
type: object
$ref: adc.yaml
description: Represents the external channels which are connected to the ADC.
properties:
reg:
items:
minimum: 0
maximum: 19
label:
description: |
Unique name to identify which channel this is.
Reserved label names "vddcore", "vddcpu", "vddq_ddr", "vrefint" and "vbat"
are used to identify internal channels with matching names.
diff-channels:
$ref: /schemas/types.yaml#/definitions/uint32-array
items:
minimum: 0
maximum: 19
st,min-sample-time-ns:
description: |
Minimum sampling time in nanoseconds. Depending on hardware (board)
e.g. high/low analog input source impedance, fine tune of ADC
sampling time may be recommended.
required:
- reg
additionalProperties: false
allOf:
- if:
properties:
compatible:
contains:
const: st,stm32f4-adc
then:
properties:
reg:
enum:
- 0x0
- 0x100
- 0x200
interrupts:
minimum: 0
maximum: 2
assigned-resolution-bits:
enum: [6, 8, 10, 12]
default: 12
st,adc-channels:
minItems: 1
maxItems: 16
items:
minimum: 0
maximum: 15
st,adc-diff-channels: false
st,min-sample-time-nsecs:
minItems: 1
maxItems: 16
items:
minimum: 80
required:
- clocks
- if:
properties:
compatible:
contains:
enum:
- st,stm32h7-adc
- st,stm32mp1-adc
then:
properties:
reg:
enum:
- 0x0
- 0x100
interrupts:
minimum: 0
maximum: 1
assigned-resolution-bits:
enum: [8, 10, 12, 14, 16]
default: 16
st,adc-channels:
minItems: 1
maxItems: 20
items:
minimum: 0
maximum: 19
st,min-sample-time-nsecs:
minItems: 1
maxItems: 20
items:
minimum: 40
- if:
properties:
compatible:
contains:
const: st,stm32mp13-adc
then:
properties:
reg:
const: 0x0
interrupts:
const: 0
assigned-resolution-bits:
enum: [6, 8, 10, 12]
default: 12
st,adc-channels:
minItems: 1
maxItems: 19
items:
minimum: 0
maximum: 18
st,min-sample-time-nsecs:
minItems: 1
maxItems: 19
items:
minimum: 40
additionalProperties: false
required:
- compatible
- reg
- interrupts
- '#io-channel-cells'
examples:
- |
// Example 1: with stm32f429, ADC1, single-ended channel 8
adc123: adc@40012000 {
compatible = "st,stm32f4-adc-core";
reg = <0x40012000 0x400>;
interrupts = <18>;
clocks = <&rcc 0 168>;
clock-names = "adc";
st,max-clk-rate-hz = <36000000>;
vdda-supply = <&vdda>;
vref-supply = <&vref>;
interrupt-controller;
#interrupt-cells = <1>;
#address-cells = <1>;
#size-cells = <0>;
adc@0 {
compatible = "st,stm32f4-adc";
#io-channel-cells = <1>;
reg = <0x0>;
clocks = <&rcc 0 168>;
interrupt-parent = <&adc123>;
interrupts = <0>;
st,adc-channels = <8>;
dmas = <&dma2 0 0 0x400 0x0>;
dma-names = "rx";
assigned-resolution-bits = <8>;
};
// ...
// other adc child nodes follow...
};
- |
// Example 2: with stm32mp157c to setup ADC1 with:
// - channels 0 & 1 as single-ended
// - channels 2 & 3 as differential (with resp. 6 & 7 negative inputs)
#include <dt-bindings/interrupt-controller/arm-gic.h>
#include <dt-bindings/clock/stm32mp1-clks.h>
adc12: adc@48003000 {
compatible = "st,stm32mp1-adc-core";
reg = <0x48003000 0x400>;
interrupts = <GIC_SPI 18 IRQ_TYPE_LEVEL_HIGH>,
<GIC_SPI 90 IRQ_TYPE_LEVEL_HIGH>;
clocks = <&rcc ADC12>, <&rcc ADC12_K>;
clock-names = "bus", "adc";
booster-supply = <&booster>;
vdd-supply = <&vdd>;
vdda-supply = <&vdda>;
vref-supply = <&vref>;
st,syscfg = <&syscfg>;
interrupt-controller;
#interrupt-cells = <1>;
#address-cells = <1>;
#size-cells = <0>;
adc@0 {
compatible = "st,stm32mp1-adc";
#io-channel-cells = <1>;
reg = <0x0>;
interrupt-parent = <&adc12>;
interrupts = <0>;
st,adc-channels = <0 1>;
st,adc-diff-channels = <2 6>, <3 7>;
st,min-sample-time-nsecs = <5000>;
dmas = <&dmamux1 9 0x400 0x05>;
dma-names = "rx";
};
// ...
// other adc child node follow...
};
- |
// Example 3: with stm32mp157c to setup ADC2 with:
// - internal channels 13, 14, 15.
#include <dt-bindings/interrupt-controller/arm-gic.h>
#include <dt-bindings/clock/stm32mp1-clks.h>
adc122: adc@48003000 {
compatible = "st,stm32mp1-adc-core";
reg = <0x48003000 0x400>;
interrupts = <GIC_SPI 18 IRQ_TYPE_LEVEL_HIGH>,
<GIC_SPI 90 IRQ_TYPE_LEVEL_HIGH>;
clocks = <&rcc ADC12>, <&rcc ADC12_K>;
clock-names = "bus", "adc";
booster-supply = <&booster>;
vdd-supply = <&vdd>;
vdda-supply = <&vdda>;
vref-supply = <&vref>;
st,syscfg = <&syscfg>;
interrupt-controller;
#interrupt-cells = <1>;
#address-cells = <1>;
#size-cells = <0>;
adc@100 {
compatible = "st,stm32mp1-adc";
#io-channel-cells = <1>;
reg = <0x100>;
interrupts = <1>;
#address-cells = <1>;
#size-cells = <0>;
channel@13 {
reg = <13>;
label = "vrefint";
st,min-sample-time-ns = <9000>;
};
channel@14 {
reg = <14>;
label = "vddcore";
st,min-sample-time-ns = <9000>;
};
channel@15 {
reg = <15>;
label = "vbat";
st,min-sample-time-ns = <9000>;
};
};
};
...