xref: /linux/Documentation/devicetree/bindings/iio/adc/adc.yaml (revision c8faf11cd192214e231626c3ee973a35d8fc33f2) 
1# SPDX-License-Identifier: GPL-2.0
2%YAML 1.2
3---
4$id: http://devicetree.org/schemas/iio/adc/adc.yaml#
5$schema: http://devicetree.org/meta-schemas/core.yaml#
6
7title: IIO Common Properties for ADC Channels
8
9maintainers:
10  - Jonathan Cameron <jic23@kernel.org>
11
12description:
13  A few properties are defined in a common way ADC channels.
14
15properties:
16  $nodename:
17    pattern: "^channel(@[0-9a-f]+)?$"
18    description:
19      A channel index should match reg.
20
21  reg:
22    maxItems: 1
23
24  label:
25    description: Unique name to identify which channel this is.
26
27  bipolar:
28    $ref: /schemas/types.yaml#/definitions/flag
29    description: If provided, the channel is to be used in bipolar mode.
30
31  diff-channels:
32    $ref: /schemas/types.yaml#/definitions/uint32-array
33    maxItems: 2
34    minItems: 2
35    description:
36      Many ADCs have dual Muxes to allow different input pins to be routed
37      to both the positive and negative inputs of a differential ADC.
38      The first value specifies the positive input pin, the second
39      specifies the negative input pin.
40
41  single-channel:
42    $ref: /schemas/types.yaml#/definitions/uint32
43    description:
44      When devices combine single-ended and differential channels, allow the
45      channel for a single element to be specified, independent of reg (as for
46      differential channels). If this and diff-channels are not present reg
47      shall be used instead.
48
49  common-mode-channel:
50    $ref: /schemas/types.yaml#/definitions/uint32
51    description:
52      Some ADCs have differential input pins that can be used to measure
53      single-ended or pseudo-differential inputs. This property can be used
54      in addition to single-channel to signal software that this channel is
55      not differential but still specify two inputs.
56
57      The input pair is specified by setting single-channel to the positive
58      input pin and common-mode-channel to the negative pin.
59
60  settling-time-us:
61    description:
62      Time between enabling the channel and first stable readings.
63
64  oversampling-ratio:
65    $ref: /schemas/types.yaml#/definitions/uint32
66    description:
67      Oversampling is used as replacement of or addition to the low-pass filter.
68      In some cases, the desired filtering characteristics are a function the
69      device design and can interact with other characteristics such as
70      settling time.
71
72anyOf:
73  - oneOf:
74      - required:
75          - reg
76          - diff-channels
77      - required:
78          - reg
79          - single-channel
80  - required:
81      - reg
82
83additionalProperties: true
84