xref: /linux/Documentation/devicetree/bindings/iio/adc/adi,ad4000.yaml (revision c8d430db8eec7d4fd13a6bea27b7086a54eda6da)
1# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2%YAML 1.2
3---
4$id: http://devicetree.org/schemas/iio/adc/adi,ad4000.yaml#
5$schema: http://devicetree.org/meta-schemas/core.yaml#
6
7title: Analog Devices AD4000 and similar Analog to Digital Converters
8
9maintainers:
10  - Marcelo Schmitt <marcelo.schmitt@analog.com>
11
12description: |
13  Analog Devices AD4000 family of Analog to Digital Converters with SPI support.
14  Specifications can be found at:
15    https://www.analog.com/media/en/technical-documentation/data-sheets/ad4000-4004-4008.pdf
16    https://www.analog.com/media/en/technical-documentation/data-sheets/ad4001-4005.pdf
17    https://www.analog.com/media/en/technical-documentation/data-sheets/ad4002-4006-4010.pdf
18    https://www.analog.com/media/en/technical-documentation/data-sheets/ad4003-4007-4011.pdf
19    https://www.analog.com/media/en/technical-documentation/data-sheets/ad4020-4021-4022.pdf
20    https://www.analog.com/media/en/technical-documentation/data-sheets/adaq4001.pdf
21    https://www.analog.com/media/en/technical-documentation/data-sheets/adaq4003.pdf
22
23$ref: /schemas/spi/spi-peripheral-props.yaml#
24
25properties:
26  compatible:
27    oneOf:
28      - const: adi,ad4000
29      - items:
30          - enum:
31              - adi,ad4004
32              - adi,ad4008
33          - const: adi,ad4000
34
35      - const: adi,ad4001
36      - items:
37          - enum:
38              - adi,ad4005
39          - const: adi,ad4001
40
41      - const: adi,ad4002
42      - items:
43          - enum:
44              - adi,ad4006
45              - adi,ad4010
46          - const: adi,ad4002
47
48      - const: adi,ad4003
49      - items:
50          - enum:
51              - adi,ad4007
52              - adi,ad4011
53          - const: adi,ad4003
54
55      - const: adi,ad4020
56      - items:
57          - enum:
58              - adi,ad4021
59              - adi,ad4022
60          - const: adi,ad4020
61
62      - const: adi,adaq4001
63
64      - const: adi,adaq4003
65
66  reg:
67    maxItems: 1
68
69  spi-max-frequency:
70    maximum: 102040816 # for VIO > 2.7 V, 81300813 for VIO > 1.7 V
71
72  adi,sdi-pin:
73    $ref: /schemas/types.yaml#/definitions/string
74    enum: [ high, low, cs, sdi ]
75    default: sdi
76    description:
77      Describes how the ADC SDI pin is wired. A value of "sdi" indicates that
78      the ADC SDI is connected to host SDO. "high" indicates that the ADC SDI
79      pin is hard-wired to logic high (VIO). "low" indicates that it is
80      hard-wired low (GND). "cs" indicates that the ADC SDI pin is connected to
81      the host CS line.
82
83  '#daisy-chained-devices': true
84
85  vdd-supply:
86    description: A 1.8V supply that powers the chip (VDD).
87
88  vio-supply:
89    description:
90      A 1.8V to 5.5V supply for the digital inputs and outputs (VIO).
91
92  ref-supply:
93    description:
94      A 2.5 to 5V supply for the external reference voltage (REF).
95
96  cnv-gpios:
97    description:
98      When provided, this property indicates the GPIO that is connected to the
99      CNV pin.
100    maxItems: 1
101
102  adi,high-z-input:
103    type: boolean
104    description:
105      High-Z mode allows the amplifier and RC filter in front of the ADC to be
106      chosen based on the signal bandwidth of interest, rather than the settling
107      requirements of the switched capacitor SAR ADC inputs.
108
109  adi,gain-milli:
110    description: |
111      The hardware gain applied to the ADC input (in milli units).
112      The gain provided by the ADC input scaler is defined by the hardware
113      connections between chip pins OUT+, R1K-, R1K1-, R1K+, R1K1+, and OUT-.
114      If not present, default to 1000 (no actual gain applied).
115    $ref: /schemas/types.yaml#/definitions/uint16
116    enum: [454, 909, 1000, 1900]
117    default: 1000
118
119  interrupts:
120    description:
121      The SDO pin can also function as a busy indicator. This node should be
122      connected to an interrupt that is triggered when the SDO line goes low
123      while the SDI line is high and the CNV line is low ("3-wire" mode) or the
124      SDI line is low and the CNV line is high ("4-wire" mode); or when the SDO
125      line goes high while the SDI and CNV lines are high (chain mode),
126    maxItems: 1
127
128required:
129  - compatible
130  - reg
131  - vdd-supply
132  - vio-supply
133  - ref-supply
134
135allOf:
136  # The configuration register can only be accessed if SDI is connected to MOSI
137  - if:
138      required:
139        - adi,sdi-pin
140    then:
141      properties:
142        adi,high-z-input: false
143  # chain mode has lower SCLK max rate
144  - if:
145      required:
146        - '#daisy-chained-devices'
147    then:
148      properties:
149        spi-max-frequency:
150          maximum: 50000000 # for VIO > 2.7 V, 40000000 for VIO > 1.7 V
151  # Gain property only applies to ADAQ devices
152  - if:
153      properties:
154        compatible:
155          not:
156            contains:
157              enum:
158                - adi,adaq4001
159                - adi,adaq4003
160    then:
161      properties:
162        adi,gain-milli: false
163
164unevaluatedProperties: false
165
166examples:
167  - |
168    #include <dt-bindings/gpio/gpio.h>
169    spi {
170        #address-cells = <1>;
171        #size-cells = <0>;
172        adc@0 {
173            compatible = "adi,ad4020";
174            reg = <0>;
175            spi-max-frequency = <71000000>;
176            vdd-supply = <&supply_1_8V>;
177            vio-supply = <&supply_1_8V>;
178            ref-supply = <&supply_5V>;
179            adi,sdi-pin = "cs";
180            cnv-gpios = <&gpio0 88 GPIO_ACTIVE_HIGH>;
181        };
182    };
183  - |
184    spi {
185        #address-cells = <1>;
186        #size-cells = <0>;
187        adc@0 {
188            compatible = "adi,adaq4003";
189            reg = <0>;
190            spi-max-frequency = <80000000>;
191            vdd-supply = <&supply_1_8V>;
192            vio-supply = <&supply_1_8V>;
193            ref-supply = <&supply_5V>;
194            adi,high-z-input;
195            adi,gain-milli = /bits/ 16 <454>;
196        };
197    };
198