xref: /linux/Documentation/devicetree/bindings/iio/adc/st,stm32-adc.yaml (revision 415e915fdfc775ad0c6675fde1008f6f43dd6251) 
1# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
2%YAML 1.2
3---
4$id: "http://devicetree.org/schemas/iio/adc/st,stm32-adc.yaml#"
5$schema: "http://devicetree.org/meta-schemas/core.yaml#"
6
7title: STMicroelectronics STM32 ADC bindings
8
9description: |
10  STM32 ADC is a successive approximation analog-to-digital converter.
11  It has several multiplexed input channels. Conversions can be performed
12  in single, continuous, scan or discontinuous mode. Result of the ADC is
13  stored in a left-aligned or right-aligned 32-bit data register.
14  Conversions can be launched in software or using hardware triggers.
15
16  The analog watchdog feature allows the application to detect if the input
17  voltage goes beyond the user-defined, higher or lower thresholds.
18
19  Each STM32 ADC block can have up to 3 ADC instances.
20
21maintainers:
22  - Fabrice Gasnier <fabrice.gasnier@st.com>
23
24properties:
25  compatible:
26    enum:
27      - st,stm32f4-adc-core
28      - st,stm32h7-adc-core
29      - st,stm32mp1-adc-core
30
31  reg:
32    maxItems: 1
33
34  interrupts:
35    description: |
36      One or more interrupts for ADC block, depending on part used:
37        - stm32f4 and stm32h7 share a common ADC interrupt line.
38        - stm32mp1 has two separate interrupt lines, one for each ADC within
39          ADC block.
40    minItems: 1
41    maxItems: 2
42
43  clocks:
44    description: |
45      Core can use up to two clocks, depending on part used:
46        - "adc" clock: for the analog circuitry, common to all ADCs.
47          It's required on stm32f4.
48          It's optional on stm32h7 and stm32mp1.
49        - "bus" clock: for registers access, common to all ADCs.
50          It's not present on stm32f4.
51          It's required on stm32h7 and stm32mp1.
52
53  clock-names: true
54
55  st,max-clk-rate-hz:
56    description:
57      Allow to specify desired max clock rate used by analog circuitry.
58
59  vdda-supply:
60    description: Phandle to the vdda input analog voltage.
61
62  vref-supply:
63    description: Phandle to the vref input analog reference voltage.
64
65  booster-supply:
66    description:
67      Phandle to the embedded booster regulator that can be used to supply ADC
68      analog input switches on stm32h7 and stm32mp1.
69
70  vdd-supply:
71    description:
72      Phandle to the vdd input voltage. It can be used to supply ADC analog
73      input switches on stm32mp1.
74
75  st,syscfg:
76    description:
77      Phandle to system configuration controller. It can be used to control the
78      analog circuitry on stm32mp1.
79    $ref: "/schemas/types.yaml#/definitions/phandle-array"
80
81  interrupt-controller: true
82
83  '#interrupt-cells':
84    const: 1
85
86  '#address-cells':
87    const: 1
88
89  '#size-cells':
90    const: 0
91
92allOf:
93  - if:
94      properties:
95        compatible:
96          contains:
97            const: st,stm32f4-adc-core
98
99    then:
100      properties:
101        clocks:
102          maxItems: 1
103
104        clock-names:
105          const: adc
106
107        interrupts:
108          items:
109            - description: interrupt line common for all ADCs
110
111        st,max-clk-rate-hz:
112          minimum: 600000
113          maximum: 36000000
114          default: 36000000
115
116        booster-supply: false
117
118        vdd-supply: false
119
120        st,syscfg: false
121
122  - if:
123      properties:
124        compatible:
125          contains:
126            const: st,stm32h7-adc-core
127
128    then:
129      properties:
130        clocks:
131          minItems: 1
132          maxItems: 2
133
134        clock-names:
135          items:
136            - const: bus
137            - const: adc
138          minItems: 1
139          maxItems: 2
140
141        interrupts:
142          items:
143            - description: interrupt line common for all ADCs
144
145        st,max-clk-rate-hz:
146          minimum: 120000
147          maximum: 36000000
148          default: 36000000
149
150        vdd-supply: false
151
152        st,syscfg: false
153
154  - if:
155      properties:
156        compatible:
157          contains:
158            const: st,stm32mp1-adc-core
159
160    then:
161      properties:
162        clocks:
163          minItems: 1
164          maxItems: 2
165
166        clock-names:
167          items:
168            - const: bus
169            - const: adc
170          minItems: 1
171          maxItems: 2
172
173        interrupts:
174          items:
175            - description: interrupt line for ADC1
176            - description: interrupt line for ADC2
177
178        st,max-clk-rate-hz:
179          minimum: 120000
180          maximum: 36000000
181          default: 36000000
182
183additionalProperties: false
184
185required:
186  - compatible
187  - reg
188  - interrupts
189  - clocks
190  - clock-names
191  - vdda-supply
192  - vref-supply
193  - interrupt-controller
194  - '#interrupt-cells'
195  - '#address-cells'
196  - '#size-cells'
197
198patternProperties:
199  "^adc@[0-9]+$":
200    type: object
201    description:
202      An ADC block node should contain at least one subnode, representing an
203      ADC instance available on the machine.
204
205    properties:
206      compatible:
207        enum:
208          - st,stm32f4-adc
209          - st,stm32h7-adc
210          - st,stm32mp1-adc
211
212      reg:
213        description: |
214          Offset of ADC instance in ADC block. Valid values are:
215            - 0x0:   ADC1
216            - 0x100: ADC2
217            - 0x200: ADC3 (stm32f4 only)
218        maxItems: 1
219
220      '#io-channel-cells':
221        const: 1
222
223      interrupts:
224        description: |
225          IRQ Line for the ADC instance. Valid values are:
226            - 0 for adc@0
227            - 1 for adc@100
228            - 2 for adc@200 (stm32f4 only)
229        maxItems: 1
230
231      clocks:
232        description:
233          Input clock private to this ADC instance. It's required only on
234          stm32f4, that has per instance clock input for registers access.
235        maxItems: 1
236
237      dmas:
238        description: RX DMA Channel
239        maxItems: 1
240
241      dma-names:
242        const: rx
243
244      assigned-resolution-bits:
245        description: |
246          Resolution (bits) to use for conversions:
247            - can be 6, 8, 10 or 12 on stm32f4
248            - can be 8, 10, 12, 14 or 16 on stm32h7 and stm32mp1
249
250      st,adc-channels:
251        description: |
252          List of single-ended channels muxed for this ADC. It can have up to:
253            - 16 channels, numbered from 0 to 15 (for in0..in15) on stm32f4
254            - 20 channels, numbered from 0 to 19 (for in0..in19) on stm32h7 and
255              stm32mp1.
256        $ref: /schemas/types.yaml#/definitions/uint32-array
257
258      st,adc-diff-channels:
259        description: |
260          List of differential channels muxed for this ADC. Some channels can
261          be configured as differential instead of single-ended on stm32h7 and
262          on stm32mp1. Positive and negative inputs pairs are listed:
263          <vinp vinn>, <vinp vinn>,... vinp and vinn are numbered from 0 to 19.
264
265          Note: At least one of "st,adc-channels" or "st,adc-diff-channels" is
266          required. Both properties can be used together. Some channels can be
267          used as single-ended and some other ones as differential (mixed). But
268          channels can't be configured both as single-ended and differential.
269        $ref: /schemas/types.yaml#/definitions/uint32-matrix
270        items:
271          items:
272            - description: |
273                "vinp" indicates positive input number
274              minimum: 0
275              maximum: 19
276            - description: |
277                "vinn" indicates negative input number
278              minimum: 0
279              maximum: 19
280
281      st,min-sample-time-nsecs:
282        description:
283          Minimum sampling time in nanoseconds. Depending on hardware (board)
284          e.g. high/low analog input source impedance, fine tune of ADC
285          sampling time may be recommended. This can be either one value or an
286          array that matches "st,adc-channels" and/or "st,adc-diff-channels"
287          list, to set sample time resp. for all channels, or independently for
288          each channel.
289        $ref: /schemas/types.yaml#/definitions/uint32-array
290
291    allOf:
292      - if:
293          properties:
294            compatible:
295              contains:
296                const: st,stm32f4-adc
297
298        then:
299          properties:
300            reg:
301              enum:
302                - 0x0
303                - 0x100
304                - 0x200
305
306            interrupts:
307              minimum: 0
308              maximum: 2
309
310            assigned-resolution-bits:
311              enum: [6, 8, 10, 12]
312              default: 12
313
314            st,adc-channels:
315              minItems: 1
316              maxItems: 16
317              items:
318                minimum: 0
319                maximum: 15
320
321            st,adc-diff-channels: false
322
323            st,min-sample-time-nsecs:
324              minItems: 1
325              maxItems: 16
326              items:
327                minimum: 80
328
329          required:
330            - clocks
331
332      - if:
333          properties:
334            compatible:
335              contains:
336                enum:
337                  - st,stm32h7-adc
338                  - st,stm32mp1-adc
339
340        then:
341          properties:
342            reg:
343              enum:
344                - 0x0
345                - 0x100
346
347            interrupts:
348              minimum: 0
349              maximum: 1
350
351            assigned-resolution-bits:
352              enum: [8, 10, 12, 14, 16]
353              default: 16
354
355            st,adc-channels:
356              minItems: 1
357              maxItems: 20
358              items:
359                minimum: 0
360                maximum: 19
361
362            st,min-sample-time-nsecs:
363              minItems: 1
364              maxItems: 20
365              items:
366                minimum: 40
367
368    additionalProperties: false
369
370    anyOf:
371      - required:
372          - st,adc-channels
373      - required:
374          - st,adc-diff-channels
375
376    required:
377      - compatible
378      - reg
379      - interrupts
380      - '#io-channel-cells'
381
382examples:
383  - |
384    // Example 1: with stm32f429, ADC1, single-ended channel 8
385      adc123: adc@40012000 {
386        compatible = "st,stm32f4-adc-core";
387        reg = <0x40012000 0x400>;
388        interrupts = <18>;
389        clocks = <&rcc 0 168>;
390        clock-names = "adc";
391        st,max-clk-rate-hz = <36000000>;
392        vdda-supply = <&vdda>;
393        vref-supply = <&vref>;
394        interrupt-controller;
395        #interrupt-cells = <1>;
396        #address-cells = <1>;
397        #size-cells = <0>;
398        adc@0 {
399          compatible = "st,stm32f4-adc";
400          #io-channel-cells = <1>;
401          reg = <0x0>;
402          clocks = <&rcc 0 168>;
403          interrupt-parent = <&adc123>;
404          interrupts = <0>;
405          st,adc-channels = <8>;
406          dmas = <&dma2 0 0 0x400 0x0>;
407          dma-names = "rx";
408          assigned-resolution-bits = <8>;
409        };
410        // ...
411        // other adc child nodes follow...
412      };
413
414  - |
415    // Example 2: with stm32mp157c to setup ADC1 with:
416    // - channels 0 & 1 as single-ended
417    // - channels 2 & 3 as differential (with resp. 6 & 7 negative inputs)
418      #include <dt-bindings/interrupt-controller/arm-gic.h>
419      #include <dt-bindings/clock/stm32mp1-clks.h>
420      adc12: adc@48003000 {
421        compatible = "st,stm32mp1-adc-core";
422        reg = <0x48003000 0x400>;
423        interrupts = <GIC_SPI 18 IRQ_TYPE_LEVEL_HIGH>,
424                     <GIC_SPI 90 IRQ_TYPE_LEVEL_HIGH>;
425        clocks = <&rcc ADC12>, <&rcc ADC12_K>;
426        clock-names = "bus", "adc";
427        booster-supply = <&booster>;
428        vdd-supply = <&vdd>;
429        vdda-supply = <&vdda>;
430        vref-supply = <&vref>;
431        st,syscfg = <&syscfg>;
432        interrupt-controller;
433        #interrupt-cells = <1>;
434        #address-cells = <1>;
435        #size-cells = <0>;
436        adc@0 {
437          compatible = "st,stm32mp1-adc";
438          #io-channel-cells = <1>;
439          reg = <0x0>;
440          interrupt-parent = <&adc12>;
441          interrupts = <0>;
442          st,adc-channels = <0 1>;
443          st,adc-diff-channels = <2 6>, <3 7>;
444          st,min-sample-time-nsecs = <5000>;
445          dmas = <&dmamux1 9 0x400 0x05>;
446          dma-names = "rx";
447        };
448        // ...
449        // other adc child node follow...
450      };
451
452...
453