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
8 title: Analog Devices AD7173 ADC
9
10 maintainers:
11 - Ceclan Dumitru <dumitru.ceclan@analog.com>
12
13 description: |
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 Analog Devices AD411x ADC's:
23 The AD411X family encompasses a series of low power, low noise, 24-bit,
24 sigma-delta analog-to-digital converters that offer a versatile range of
25 specifications. They integrate an analog front end suitable for processing
26 fully differential/single-ended and bipolar voltage inputs.
27
28 Datasheets for supported chips:
29 https://www.analog.com/media/en/technical-documentation/data-sheets/AD4111.pdf
30 https://www.analog.com/media/en/technical-documentation/data-sheets/AD4112.pdf
31 https://www.analog.com/media/en/technical-documentation/data-sheets/AD4114.pdf
32 https://www.analog.com/media/en/technical-documentation/data-sheets/AD4115.pdf
33 https://www.analog.com/media/en/technical-documentation/data-sheets/AD4116.pdf
34 https://www.analog.com/media/en/technical-documentation/data-sheets/AD7172-2.pdf
35 https://www.analog.com/media/en/technical-documentation/data-sheets/AD7172-4.pdf
36 https://www.analog.com/media/en/technical-documentation/data-sheets/AD7173-8.pdf
37 https://www.analog.com/media/en/technical-documentation/data-sheets/AD7175-2.pdf
38 https://www.analog.com/media/en/technical-documentation/data-sheets/AD7175-8.pdf
39 https://www.analog.com/media/en/technical-documentation/data-sheets/AD7176-2.pdf
40 https://www.analog.com/media/en/technical-documentation/data-sheets/AD7177-2.pdf
41
42 properties:
43 compatible:
44 enum:
45 - adi,ad4111
46 - adi,ad4112
47 - adi,ad4114
48 - adi,ad4115
49 - adi,ad4116
50 - adi,ad7172-2
51 - adi,ad7172-4
52 - adi,ad7173-8
53 - adi,ad7175-2
54 - adi,ad7175-8
55 - adi,ad7176-2
56 - adi,ad7177-2
57
58 reg:
59 maxItems: 1
60
61 interrupts:
62 minItems: 1
63 items:
64 - description: |
65 Ready: multiplexed with SPI data out. While SPI CS is low,
66 can be used to indicate the completion of a conversion.
67
68 - description: |
69 Error: The three error bits in the status register (ADC_ERROR, CRC_ERROR,
70 and REG_ERROR) are OR'ed, inverted, and mapped to the ERROR pin.
71 Therefore, the ERROR pin indicates that an error has occurred.
72
73 interrupt-names:
74 minItems: 1
75 items:
76 - const: rdy
77 - const: err
78
79 '#address-cells':
80 const: 1
81
82 '#size-cells':
83 const: 0
84
85 spi-max-frequency:
86 maximum: 20000000
87
88 gpio-controller:
89 description: Marks the device node as a GPIO controller.
90
91 '#gpio-cells':
92 const: 2
93 description:
94 The first cell is the GPIO number and the second cell specifies
95 GPIO flags, as defined in <dt-bindings/gpio/gpio.h>.
96
97 vref-supply:
98 description: |
99 Differential external reference supply used for conversion. The reference
100 voltage (Vref) specified here must be the voltage difference between the
101 REF+ and REF- pins: Vref = (REF+) - (REF-).
102
103 vref2-supply:
104 description: |
105 Differential external reference supply used for conversion. The reference
106 voltage (Vref2) specified here must be the voltage difference between the
107 REF2+ and REF2- pins: Vref2 = (REF2+) - (REF2-).
108
109 avdd-supply:
110 description: Avdd supply, can be used as reference for conversion.
111 This supply is referenced to AVSS, voltage specified here
112 represents (AVDD1 - AVSS).
113
114 avdd2-supply:
115 description: Avdd2 supply, used as the input to the internal voltage regulator.
116 This supply is referenced to AVSS, voltage specified here
117 represents (AVDD2 - AVSS).
118
119 iovdd-supply:
120 description: iovdd supply, used for the chip digital interface.
121
122 clocks:
123 maxItems: 1
124 description: |
125 Optional external clock source. Can include one clock source: external
126 clock or external crystal.
127
128 clock-names:
129 enum:
130 - ext-clk
131 - xtal
132
133 '#clock-cells':
134 const: 0
135
136 patternProperties:
137 "^channel@[0-9a-f]$":
138 type: object
139 $ref: adc.yaml
140 unevaluatedProperties: false
141
142 properties:
143 reg:
144 minimum: 0
145 maximum: 15
146
147 diff-channels:
148 description: |
149 This property is used for defining the inputs of a differential
150 voltage channel. The first value is the positive input and the second
151 value is the negative input of the channel.
152
153 Family AD411x supports a dedicated VINCOM voltage input.
154 To select it set the second channel to 16.
155 (VIN2, VINCOM) -> diff-channels = <2 16>
156
157 There are special values that can be selected besides the voltage
158 analog inputs:
159 21: REF+
160 22: REF−
161
162 Supported only by AD7172-2, AD7172-4, AD7175-2, AD7175-8, AD7177-2,
163 must be paired together and can be used to monitor the power supply
164 of the ADC:
165 19: ((AVDD1 − AVSS)/5)+
166 20: ((AVDD1 − AVSS)/5)−
167
168 items:
169 minimum: 0
170 maximum: 31
171
172 single-channel:
173 description: |
174 This property is used for defining a current channel or the positive
175 input of a voltage channel (single-ended or pseudo-differential).
176
177 Models AD4111 and AD4112 support current channels.
178 Example: (IIN2+, IIN2−) -> single-channel = <2>
179 To correctly configure a current channel set the "adi,current-channel"
180 property to true.
181
182 To configure a single-ended/pseudo-differential channel set the
183 "common-mode-channel" property to the desired negative voltage input.
184
185 When used as a voltage channel, special inputs are valid as well.
186 minimum: 0
187 maximum: 31
188
189 common-mode-channel:
190 description:
191 This property is used for defining the negative input of a
192 single-ended or pseudo-differential voltage channel.
193
194 Special inputs are valid as well.
195 minimum: 0
196 maximum: 31
197
198 adi,reference-select:
199 description: |
200 Select the reference source to use when converting on
201 the specific channel. Valid values are:
202 vref : REF+ /REF−
203 vref2 : REF2+ /REF2−
204 refout-avss: REFOUT/AVSS (Internal reference)
205 avdd : AVDD /AVSS
206
207 External reference ref2 only available on ad7173-8 and ad7172-4.
208 Internal reference refout-avss not available on ad7172-4.
209
210 If not specified, internal reference used (if available).
211 $ref: /schemas/types.yaml#/definitions/string
212 enum:
213 - vref
214 - vref2
215 - refout-avss
216 - avdd
217 default: refout-avss
218
219 adi,current-channel:
220 $ref: /schemas/types.yaml#/definitions/flag
221 description: |
222 Signal that the selected inputs are current channels.
223 Only available on AD4111 and AD4112.
224
225 required:
226 - reg
227
228 allOf:
229 - oneOf:
230 - required: [single-channel]
231 properties:
232 diff-channels: false
233 - required: [diff-channels]
234 properties:
235 single-channel: false
236 adi,current-channel: false
237 common-mode-channel: false
238
239 - if:
240 required: [common-mode-channel]
241 then:
242 properties:
243 adi,current-channel: false
244
245 required:
246 - compatible
247 - reg
248
249 allOf:
250 - $ref: /schemas/spi/spi-peripheral-props.yaml#
251
252 # Only ad7172-4, ad7173-8 and ad7175-8 support vref2
253 - if:
254 properties:
255 compatible:
256 not:
257 contains:
258 enum:
259 - adi,ad7172-4
260 - adi,ad7173-8
261 - adi,ad7175-8
262 then:
263 properties:
264 vref2-supply: false
265 patternProperties:
266 "^channel@[0-9a-f]$":
267 properties:
268 adi,reference-select:
269 enum:
270 - vref
271 - refout-avss
272 - avdd
273
274 - if:
275 properties:
276 compatible:
277 contains:
278 enum:
279 - adi,ad4114
280 - adi,ad4115
281 - adi,ad4116
282 - adi,ad7173-8
283 - adi,ad7175-8
284 then:
285 patternProperties:
286 "^channel@[0-9a-f]$":
287 properties:
288 reg:
289 maximum: 15
290
291 - if:
292 properties:
293 compatible:
294 contains:
295 enum:
296 - adi,ad7172-2
297 - adi,ad7175-2
298 - adi,ad7176-2
299 - adi,ad7177-2
300 then:
301 patternProperties:
302 "^channel@[0-9a-f]$":
303 properties:
304 reg:
305 maximum: 3
306
307 # Model ad7172-4 does not support internal reference
308 - if:
309 properties:
310 compatible:
311 contains:
312 const: adi,ad7172-4
313 then:
314 patternProperties:
315 "^channel@[0-9a-f]$":
316 properties:
317 reg:
318 maximum: 7
319 adi,reference-select:
320 enum:
321 - vref
322 - vref2
323 - avdd
324 required:
325 - adi,reference-select
326
327 - if:
328 properties:
329 compatible:
330 contains:
331 enum:
332 - adi,ad4111
333 - adi,ad4112
334 - adi,ad4114
335 - adi,ad4115
336 - adi,ad4116
337 then:
338 properties:
339 avdd2-supply: false
340
341 - if:
342 properties:
343 compatible:
344 not:
345 contains:
346 enum:
347 - adi,ad4111
348 - adi,ad4112
349 then:
350 patternProperties:
351 "^channel@[0-9a-f]$":
352 properties:
353 adi,current-channel: false
354
355 - if:
356 anyOf:
357 - required: [clock-names]
358 - required: [clocks]
359 then:
360 properties:
361 '#clock-cells': false
362
363 unevaluatedProperties: false
364
365 examples:
366 # Example AD7173-8 with external reference connected to REF+/REF-:
367 - |
368 #include <dt-bindings/gpio/gpio.h>
369 #include <dt-bindings/interrupt-controller/irq.h>
370
371 spi {
372 #address-cells = <1>;
373 #size-cells = <0>;
374
375 adc@0 {
376 compatible = "adi,ad7173-8";
377 reg = <0>;
378
379 #address-cells = <1>;
380 #size-cells = <0>;
381
382 interrupts = <25 IRQ_TYPE_EDGE_FALLING>;
383 interrupt-names = "rdy";
384 interrupt-parent = <&gpio>;
385 spi-max-frequency = <5000000>;
386 gpio-controller;
387 #gpio-cells = <2>;
388 #clock-cells = <0>;
389
390 vref-supply = <&dummy_regulator>;
391
392 channel@0 {
393 reg = <0>;
394 bipolar;
395 diff-channels = <0 1>;
396 adi,reference-select = "vref";
397 };
398
399 channel@1 {
400 reg = <1>;
401 diff-channels = <2 3>;
402 };
403
404 channel@2 {
405 reg = <2>;
406 bipolar;
407 diff-channels = <4 5>;
408 };
409
410 channel@3 {
411 reg = <3>;
412 bipolar;
413 diff-channels = <6 7>;
414 };
415
416 channel@4 {
417 reg = <4>;
418 diff-channels = <8 9>;
419 adi,reference-select = "avdd";
420 };
421 };
422 };
423
424 # Example AD4111 with current channel and single-ended channel:
425 - |
426 #include <dt-bindings/gpio/gpio.h>
427 #include <dt-bindings/interrupt-controller/irq.h>
428
429 spi {
430 #address-cells = <1>;
431 #size-cells = <0>;
432
433 adc@0 {
434 compatible = "adi,ad4111";
435 reg = <0>;
436
437 #address-cells = <1>;
438 #size-cells = <0>;
439
440 interrupts = <25 IRQ_TYPE_EDGE_FALLING>;
441 interrupt-names = "rdy";
442 interrupt-parent = <&gpio>;
443 spi-max-frequency = <5000000>;
444 gpio-controller;
445 #gpio-cells = <2>;
446 #clock-cells = <0>;
447
448 channel@0 {
449 reg = <0>;
450 bipolar;
451 diff-channels = <4 5>;
452 };
453
454 // Single ended channel VIN2/VINCOM
455 channel@1 {
456 reg = <1>;
457 bipolar;
458 single-channel = <2>;
459 common-mode-channel = <16>;
460 };
461
462 // Current channel IN2+/IN2-
463 channel@2 {
464 reg = <2>;
465 single-channel = <2>;
466 adi,current-channel;
467 };
468 };
469 };
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