# SPDX-License-Identifier: GPL-2.0-only
%YAML 1.2
---
$id: http://devicetree.org/schemas/iio/adc/qcom,spmi-vadc.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: Qualcomm's SPMI PMIC ADC
maintainers:
- Andy Gross <agross@kernel.org>
- Bjorn Andersson <bjorn.andersson@linaro.org>
description: |
SPMI PMIC voltage ADC (VADC) provides interface to clients to read
voltage. The VADC is a 15-bit sigma-delta ADC.
SPMI PMIC5/PMIC7 voltage ADC (ADC) provides interface to clients to read
voltage. The VADC is a 16-bit sigma-delta ADC.
properties:
compatible:
oneOf:
- items:
- const: qcom,pms405-adc
- const: qcom,spmi-adc-rev2
- enum:
- qcom,spmi-vadc
- qcom,spmi-adc5
- qcom,spmi-adc-rev2
- qcom,spmi-adc7
reg:
description: VADC base address in the SPMI PMIC register map
maxItems: 1
'#address-cells':
const: 1
'#size-cells':
const: 0
'#io-channel-cells':
const: 1
interrupts:
maxItems: 1
description:
End of conversion interrupt.
required:
- compatible
- reg
- '#address-cells'
- '#size-cells'
- '#io-channel-cells'
patternProperties:
"^channel@[0-9a-f]+$":
type: object
additionalProperties: false
description: |
Represents the external channels which are connected to the ADC.
For compatible property "qcom,spmi-vadc" following channels, also known as
reference point channels, are used for result calibration and their channel
configuration nodes should be defined:
VADC_REF_625MV and/or VADC_SPARE1(based on PMIC version) VADC_REF_1250MV,
VADC_GND_REF and VADC_VDD_VADC.
properties:
reg:
maxItems: 1
description: |
ADC channel number.
See include/dt-bindings/iio/qcom,spmi-vadc.h
For PMIC7 ADC, the channel numbers are specified separately per PMIC
in the PMIC-specific files in include/dt-bindings/iio/.
label:
$ref: /schemas/types.yaml#/definitions/string
description: |
ADC input of the platform as seen in the schematics.
For thermistor inputs connected to generic AMUX or GPIO inputs
these can vary across platform for the same pins. Hence select
the platform schematics name for this channel.
qcom,decimation:
$ref: /schemas/types.yaml#/definitions/uint32
description: |
This parameter is used to decrease ADC sampling rate.
Quicker measurements can be made by reducing decimation ratio.
qcom,pre-scaling:
description: |
Used for scaling the channel input signal before the signal is
fed to VADC. The configuration for this node is to know the
pre-determined ratio and use it for post scaling. It is a pair of
integers, denoting the numerator and denominator of the fraction by which
input signal is multiplied. For example, <1 3> indicates the signal is scaled
down to 1/3 of its value before ADC measurement.
If property is not found default value depending on chip will be used.
$ref: /schemas/types.yaml#/definitions/uint32-array
oneOf:
- items:
- const: 1
- enum: [ 1, 3, 4, 6, 20, 8, 10, 16 ]
- items:
- const: 10
- const: 81
qcom,ratiometric:
description: |
Channel calibration type.
- For compatible property "qcom,spmi-vadc", if this property is
specified VADC will use the VDD reference (1.8V) and GND for
channel calibration. If property is not found, channel will be
calibrated with 0.625V and 1.25V reference channels, also
known as absolute calibration.
- For compatible property "qcom,spmi-adc5", "qcom,spmi-adc7" and
"qcom,spmi-adc-rev2", if this property is specified VADC will use
the VDD reference (1.875V) and GND for channel calibration. If
property is not found, channel will be calibrated with 0V and 1.25V
reference channels, also known as absolute calibration.
type: boolean
qcom,hw-settle-time:
$ref: /schemas/types.yaml#/definitions/uint32
description: |
Time between AMUX getting configured and the ADC starting
conversion. The 'hw_settle_time' is an index used from valid values
and programmed in hardware to achieve the hardware settling delay.
qcom,avg-samples:
$ref: /schemas/types.yaml#/definitions/uint32
description: |
Number of samples to be used for measurement.
Averaging provides the option to obtain a single measurement
from the ADC that is an average of multiple samples. The value
selected is 2^(value).
required:
- reg
allOf:
- if:
properties:
compatible:
contains:
const: qcom,spmi-vadc
then:
patternProperties:
"^channel@[0-9a-f]+$":
properties:
qcom,decimation:
enum: [ 512, 1024, 2048, 4096 ]
default: 512
qcom,hw-settle-time:
enum: [ 0, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1, 2,
4, 6, 8, 10 ]
default: 0
qcom,avg-samples:
enum: [ 1, 2, 4, 8, 16, 32, 64, 128, 256, 512 ]
default: 1
- if:
properties:
compatible:
contains:
const: qcom,spmi-adc-rev2
then:
patternProperties:
"^channel@[0-9a-f]+$":
properties:
qcom,decimation:
enum: [ 256, 512, 1024 ]
default: 1024
qcom,hw-settle-time:
enum: [ 0, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1, 2,
4, 6, 8, 10 ]
default: 0
qcom,avg-samples:
enum: [ 1, 2, 4, 8, 16 ]
default: 1
- if:
properties:
compatible:
contains:
const: qcom,spmi-adc5
then:
patternProperties:
"^channel@[0-9a-f]+$":
properties:
qcom,decimation:
enum: [ 250, 420, 840 ]
default: 840
qcom,hw-settle-time:
enum: [ 15, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1, 2,
4, 6, 8, 10, 16, 32, 64, 128 ]
default: 15
qcom,avg-samples:
enum: [ 1, 2, 4, 8, 16 ]
default: 1
- if:
properties:
compatible:
contains:
const: qcom,spmi-adc7
then:
patternProperties:
"^channel@[0-9a-f]+$":
properties:
qcom,decimation:
enum: [ 85, 340, 1360 ]
default: 1360
qcom,hw-settle-time:
enum: [ 15, 100, 200, 300, 400, 500, 600, 700, 1000, 2000, 4000,
8000, 16000, 32000, 64000, 128000 ]
default: 15
qcom,avg-samples:
enum: [ 1, 2, 4, 8, 16 ]
default: 1
additionalProperties: false
examples:
- |
spmi {
#address-cells = <1>;
#size-cells = <0>;
/* VADC node */
pmic_vadc: adc@3100 {
compatible = "qcom,spmi-vadc";
reg = <0x3100>;
interrupts = <0x0 0x31 0x0 0x1>;
#address-cells = <1>;
#size-cells = <0>;
#io-channel-cells = <1>;
/* Channel node */
channel@39 {
reg = <0x39>;
qcom,decimation = <512>;
qcom,ratiometric;
qcom,hw-settle-time = <200>;
qcom,avg-samples = <1>;
qcom,pre-scaling = <1 3>;
};
channel@9 {
reg = <0x9>;
};
channel@a {
reg = <0xa>;
};
channel@e {
reg = <0xe>;
};
channel@f {
reg = <0xf>;
};
};
};
- |
#include <dt-bindings/iio/qcom,spmi-adc7-pmk8350.h>
#include <dt-bindings/iio/qcom,spmi-adc7-pm8350.h>
#include <dt-bindings/interrupt-controller/irq.h>
spmi {
#address-cells = <1>;
#size-cells = <0>;
adc@3100 {
reg = <0x3100>;
compatible = "qcom,spmi-adc7";
#address-cells = <1>;
#size-cells = <0>;
#io-channel-cells = <1>;
/* Other properties are omitted */
channel@44 {
reg = <PMK8350_ADC7_AMUX_THM1_100K_PU>;
qcom,ratiometric;
qcom,hw-settle-time = <200>;
label = "xo_therm";
};
channel@47 {
reg = <PM8350_ADC7_AMUX_THM4_100K_PU(1)>;
qcom,ratiometric;
qcom,hw-settle-time = <200>;
label = "conn_therm";
};
};
};