xref: /linux/Documentation/devicetree/bindings/iio/adc/adi,ad7173.yaml (revision 0c8ea05e9b3d8e5287e2a968f2a2e744dfd31b99) 
1# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
2# Copyright 2023 Analog Devices Inc.
3%YAML 1.2
4---
5$id: http://devicetree.org/schemas/iio/adc/adi,ad7173.yaml#
6$schema: http://devicetree.org/meta-schemas/core.yaml#
7
8title: Analog Devices AD7173 ADC
9
10maintainers:
11  - Ceclan Dumitru <dumitru.ceclan@analog.com>
12
13description: |
14  Analog Devices AD717x ADC's:
15  The AD717x family offer a complete integrated Sigma-Delta ADC solution which
16  can be used in high precision, low noise single channel applications
17  (Life Science measurements) or higher speed multiplexed applications
18  (Factory Automation PLC Input modules). The Sigma-Delta ADC is intended
19  primarily for measurement of signals close to DC but also delivers
20  outstanding performance with input bandwidths out to ~10kHz.
21
22  Datasheets for supported chips:
23    https://www.analog.com/media/en/technical-documentation/data-sheets/AD7172-2.pdf
24    https://www.analog.com/media/en/technical-documentation/data-sheets/AD7172-4.pdf
25    https://www.analog.com/media/en/technical-documentation/data-sheets/AD7173-8.pdf
26    https://www.analog.com/media/en/technical-documentation/data-sheets/AD7175-2.pdf
27    https://www.analog.com/media/en/technical-documentation/data-sheets/AD7175-8.pdf
28    https://www.analog.com/media/en/technical-documentation/data-sheets/AD7176-2.pdf
29    https://www.analog.com/media/en/technical-documentation/data-sheets/AD7177-2.pdf
30
31properties:
32  compatible:
33    enum:
34      - adi,ad7172-2
35      - adi,ad7172-4
36      - adi,ad7173-8
37      - adi,ad7175-2
38      - adi,ad7175-8
39      - adi,ad7176-2
40      - adi,ad7177-2
41
42  reg:
43    maxItems: 1
44
45  interrupts:
46    minItems: 1
47    items:
48      - description: |
49          Ready: multiplexed with SPI data out. While SPI CS is low,
50          can be used to indicate the completion of a conversion.
51
52      - description: |
53          Error: The three error bits in the status register (ADC_ERROR, CRC_ERROR,
54          and REG_ERROR) are OR'ed, inverted, and mapped to the ERROR pin.
55          Therefore, the ERROR pin indicates that an error has occurred.
56
57  interrupt-names:
58    minItems: 1
59    items:
60      - const: rdy
61      - const: err
62
63  '#address-cells':
64    const: 1
65
66  '#size-cells':
67    const: 0
68
69  spi-max-frequency:
70    maximum: 20000000
71
72  gpio-controller:
73    description: Marks the device node as a GPIO controller.
74
75  '#gpio-cells':
76    const: 2
77    description:
78      The first cell is the GPIO number and the second cell specifies
79      GPIO flags, as defined in <dt-bindings/gpio/gpio.h>.
80
81  vref-supply:
82    description: |
83      Differential external reference supply used for conversion. The reference
84      voltage (Vref) specified here must be the voltage difference between the
85      REF+ and REF- pins: Vref = (REF+) - (REF-).
86
87  vref2-supply:
88    description: |
89      Differential external reference supply used for conversion. The reference
90      voltage (Vref2) specified here must be the voltage difference between the
91      REF2+ and REF2- pins: Vref2 = (REF2+) - (REF2-).
92
93  avdd-supply:
94    description: Avdd supply, can be used as reference for conversion.
95                 This supply is referenced to AVSS, voltage specified here
96                 represents (AVDD1 - AVSS).
97
98  avdd2-supply:
99    description: Avdd2 supply, used as the input to the internal voltage regulator.
100                 This supply is referenced to AVSS, voltage specified here
101                 represents (AVDD2 - AVSS).
102
103  iovdd-supply:
104    description: iovdd supply, used for the chip digital interface.
105
106  clocks:
107    maxItems: 1
108    description: |
109      Optional external clock source. Can include one clock source: external
110      clock or external crystal.
111
112  clock-names:
113    enum:
114      - ext-clk
115      - xtal
116
117  '#clock-cells':
118    const: 0
119
120patternProperties:
121  "^channel@[0-9a-f]$":
122    type: object
123    $ref: adc.yaml
124    unevaluatedProperties: false
125
126    properties:
127      reg:
128        minimum: 0
129        maximum: 15
130
131      diff-channels:
132        items:
133          minimum: 0
134          maximum: 31
135
136      adi,reference-select:
137        description: |
138          Select the reference source to use when converting on
139          the specific channel. Valid values are:
140          vref       : REF+  /REF−
141          vref2      : REF2+ /REF2−
142          refout-avss: REFOUT/AVSS (Internal reference)
143          avdd       : AVDD  /AVSS
144
145          External reference ref2 only available on ad7173-8 and ad7172-4.
146          Internal reference refout-avss not available on ad7172-4.
147
148          If not specified, internal reference used (if available).
149        $ref: /schemas/types.yaml#/definitions/string
150        enum:
151          - vref
152          - vref2
153          - refout-avss
154          - avdd
155        default: refout-avss
156
157    required:
158      - reg
159      - diff-channels
160
161required:
162  - compatible
163  - reg
164
165allOf:
166  - $ref: /schemas/spi/spi-peripheral-props.yaml#
167
168  # Only ad7172-4, ad7173-8 and ad7175-8 support vref2
169  # Other models have [0-3] channel registers
170  - if:
171      properties:
172        compatible:
173          not:
174            contains:
175              enum:
176                - adi,ad7172-4
177                - adi,ad7173-8
178                - adi,ad7175-8
179    then:
180      properties:
181        vref2-supply: false
182      patternProperties:
183        "^channel@[0-9a-f]$":
184          properties:
185            adi,reference-select:
186              enum:
187                - vref
188                - refout-avss
189                - avdd
190            reg:
191              maximum: 3
192
193  # Model ad7172-4 does not support internal reference
194  - if:
195      properties:
196        compatible:
197          contains:
198            const: adi,ad7172-4
199    then:
200      patternProperties:
201        "^channel@[0-9a-f]$":
202          properties:
203            reg:
204              maximum: 7
205            adi,reference-select:
206              enum:
207                - vref
208                - vref2
209                - avdd
210          required:
211            - adi,reference-select
212
213  - if:
214      anyOf:
215        - required: [clock-names]
216        - required: [clocks]
217    then:
218      properties:
219        '#clock-cells': false
220
221unevaluatedProperties: false
222
223examples:
224  - |
225    #include <dt-bindings/gpio/gpio.h>
226    #include <dt-bindings/interrupt-controller/irq.h>
227
228    spi {
229      #address-cells = <1>;
230      #size-cells = <0>;
231
232      adc@0 {
233        compatible = "adi,ad7173-8";
234        reg = <0>;
235
236        #address-cells = <1>;
237        #size-cells = <0>;
238
239        interrupts = <25 IRQ_TYPE_EDGE_FALLING>;
240        interrupt-names = "rdy";
241        interrupt-parent = <&gpio>;
242        spi-max-frequency = <5000000>;
243        gpio-controller;
244        #gpio-cells = <2>;
245        #clock-cells = <0>;
246
247        vref-supply = <&dummy_regulator>;
248
249        channel@0 {
250          reg = <0>;
251          bipolar;
252          diff-channels = <0 1>;
253          adi,reference-select = "vref";
254        };
255
256        channel@1 {
257          reg = <1>;
258          diff-channels = <2 3>;
259        };
260
261        channel@2 {
262          reg = <2>;
263          bipolar;
264          diff-channels = <4 5>;
265        };
266
267        channel@3 {
268          reg = <3>;
269          bipolar;
270          diff-channels = <6 7>;
271        };
272
273        channel@4 {
274          reg = <4>;
275          diff-channels = <8 9>;
276          adi,reference-select = "avdd";
277        };
278      };
279    };
280