xref: /linux/Documentation/devicetree/bindings/iio/adc/qcom,spmi-vadc.yaml (revision 1dd4505cf4c8c3bffaf762d2c2d7c443a52275f0)
1# SPDX-License-Identifier: GPL-2.0-only
2%YAML 1.2
3---
4$id: http://devicetree.org/schemas/iio/adc/qcom,spmi-vadc.yaml#
5$schema: http://devicetree.org/meta-schemas/core.yaml#
6
7title: Qualcomm's SPMI PMIC ADC
8
9maintainers:
10  - Andy Gross <agross@kernel.org>
11  - Bjorn Andersson <bjorn.andersson@linaro.org>
12
13description: |
14  SPMI PMIC voltage ADC (VADC) provides interface to clients to read
15  voltage. The VADC is a 15-bit sigma-delta ADC.
16  SPMI PMIC5/PMIC7 voltage ADC (ADC) provides interface to clients to read
17  voltage. The VADC is a 16-bit sigma-delta ADC.
18
19properties:
20  compatible:
21    oneOf:
22      - items:
23          - const: qcom,pms405-adc
24          - const: qcom,spmi-adc-rev2
25      - enum:
26          - qcom,spmi-vadc
27          - qcom,spmi-adc5
28          - qcom,spmi-adc-rev2
29          - qcom,spmi-adc7
30
31  reg:
32    description: VADC base address in the SPMI PMIC register map
33    maxItems: 1
34
35  '#address-cells':
36    const: 1
37
38  '#size-cells':
39    const: 0
40
41  '#io-channel-cells':
42    const: 1
43
44  interrupts:
45    maxItems: 1
46    description:
47      End of conversion interrupt.
48
49required:
50  - compatible
51  - reg
52  - '#address-cells'
53  - '#size-cells'
54  - '#io-channel-cells'
55
56patternProperties:
57  "^channel@[0-9a-f]+$":
58    type: object
59    additionalProperties: false
60    description: |
61      Represents the external channels which are connected to the ADC.
62      For compatible property "qcom,spmi-vadc" following channels, also known as
63      reference point channels, are used for result calibration and their channel
64      configuration nodes should be defined:
65      VADC_REF_625MV and/or VADC_SPARE1(based on PMIC version) VADC_REF_1250MV,
66      VADC_GND_REF and VADC_VDD_VADC.
67
68    properties:
69      reg:
70        maxItems: 1
71        description: |
72          ADC channel number.
73          See include/dt-bindings/iio/qcom,spmi-vadc.h
74          For PMIC7 ADC, the channel numbers are specified separately per PMIC
75          in the PMIC-specific files in include/dt-bindings/iio/.
76
77      label:
78        description: |
79            ADC input of the platform as seen in the schematics.
80            For thermistor inputs connected to generic AMUX or GPIO inputs
81            these can vary across platform for the same pins. Hence select
82            the platform schematics name for this channel.
83
84      qcom,decimation:
85        $ref: /schemas/types.yaml#/definitions/uint32
86        description: |
87            This parameter is used to decrease ADC sampling rate.
88            Quicker measurements can be made by reducing decimation ratio.
89
90      qcom,pre-scaling:
91        description: |
92            Used for scaling the channel input signal before the signal is
93            fed to VADC. The configuration for this node is to know the
94            pre-determined ratio and use it for post scaling. It is a pair of
95            integers, denoting the numerator and denominator of the fraction by which
96            input signal is multiplied. For example, <1 3> indicates the signal is scaled
97            down to 1/3 of its value before ADC measurement.
98            If property is not found default value depending on chip will be used.
99        $ref: /schemas/types.yaml#/definitions/uint32-array
100        oneOf:
101          - items:
102              - const: 1
103              - enum: [ 1, 3, 4, 6, 20, 8, 10, 16 ]
104          - items:
105              - const: 10
106              - const: 81
107
108      qcom,ratiometric:
109        description: |
110            Channel calibration type.
111            - For compatible property "qcom,spmi-vadc", if this property is
112              specified VADC will use the VDD reference (1.8V) and GND for
113              channel calibration. If property is not found, channel will be
114              calibrated with 0.625V and 1.25V reference channels, also
115              known as absolute calibration.
116            - For compatible property "qcom,spmi-adc5", "qcom,spmi-adc7" and
117              "qcom,spmi-adc-rev2", if this property is specified VADC will use
118              the VDD reference (1.875V) and GND for channel calibration. If
119              property is not found, channel will be calibrated with 0V and 1.25V
120              reference channels, also known as absolute calibration.
121        type: boolean
122
123      qcom,hw-settle-time:
124        $ref: /schemas/types.yaml#/definitions/uint32
125        description: |
126            Time between AMUX getting configured and the ADC starting
127            conversion. The 'hw_settle_time' is an index used from valid values
128            and programmed in hardware to achieve the hardware settling delay.
129
130      qcom,avg-samples:
131        $ref: /schemas/types.yaml#/definitions/uint32
132        description: |
133            Number of samples to be used for measurement.
134            Averaging provides the option to obtain a single measurement
135            from the ADC that is an average of multiple samples. The value
136            selected is 2^(value).
137
138    required:
139      - reg
140
141allOf:
142  - if:
143      properties:
144        compatible:
145          contains:
146            const: qcom,spmi-vadc
147
148    then:
149      patternProperties:
150        "^channel@[0-9a-f]+$":
151          properties:
152            qcom,decimation:
153              enum: [ 512, 1024, 2048, 4096 ]
154              default: 512
155
156            qcom,hw-settle-time:
157              enum: [ 0, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1, 2,
158                      4, 6, 8, 10 ]
159              default: 0
160
161            qcom,avg-samples:
162              enum: [ 1, 2, 4, 8, 16, 32, 64, 128, 256, 512 ]
163              default: 1
164
165  - if:
166      properties:
167        compatible:
168          contains:
169            const: qcom,spmi-adc-rev2
170
171    then:
172      patternProperties:
173        "^channel@[0-9a-f]+$":
174          properties:
175            qcom,decimation:
176              enum: [ 256, 512, 1024 ]
177              default: 1024
178
179            qcom,hw-settle-time:
180              enum: [ 0, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1, 2,
181                      4, 6, 8, 10 ]
182              default: 0
183
184            qcom,avg-samples:
185              enum: [ 1, 2, 4, 8, 16 ]
186              default: 1
187
188  - if:
189      properties:
190        compatible:
191          contains:
192            const: qcom,spmi-adc5
193
194    then:
195      patternProperties:
196        "^channel@[0-9a-f]+$":
197          properties:
198            qcom,decimation:
199              enum: [ 250, 420, 840 ]
200              default: 840
201
202            qcom,hw-settle-time:
203              enum: [ 15, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1, 2,
204                      4, 6, 8, 10, 16, 32, 64, 128 ]
205              default: 15
206
207            qcom,avg-samples:
208              enum: [ 1, 2, 4, 8, 16 ]
209              default: 1
210
211  - if:
212      properties:
213        compatible:
214          contains:
215            const: qcom,spmi-adc7
216
217    then:
218      patternProperties:
219        "^channel@[0-9a-f]+$":
220          properties:
221            qcom,decimation:
222              enum: [ 85, 340, 1360 ]
223              default: 1360
224
225            qcom,hw-settle-time:
226              enum: [ 15, 100, 200, 300, 400, 500, 600, 700, 1000, 2000, 4000,
227                      8000, 16000, 32000, 64000, 128000 ]
228              default: 15
229
230            qcom,avg-samples:
231              enum: [ 1, 2, 4, 8, 16 ]
232              default: 1
233
234additionalProperties: false
235
236examples:
237  - |
238    pmic {
239        #address-cells = <1>;
240        #size-cells = <0>;
241
242        adc@3100 {
243            compatible = "qcom,spmi-vadc";
244            reg = <0x3100>;
245            interrupts = <0x0 0x31 0x0 0x1>;
246            #address-cells = <1>;
247            #size-cells = <0>;
248            #io-channel-cells = <1>;
249
250            /* Channel node */
251            channel@39 {
252                reg = <0x39>;
253                qcom,decimation = <512>;
254                qcom,ratiometric;
255                qcom,hw-settle-time = <200>;
256                qcom,avg-samples = <1>;
257                qcom,pre-scaling = <1 3>;
258            };
259
260            channel@9 {
261                reg = <0x9>;
262            };
263
264            channel@a {
265                reg = <0xa>;
266            };
267
268            channel@e {
269                reg = <0xe>;
270            };
271
272            channel@f {
273                reg = <0xf>;
274            };
275        };
276    };
277
278  - |
279    #include <dt-bindings/iio/qcom,spmi-adc7-pmk8350.h>
280    #include <dt-bindings/iio/qcom,spmi-adc7-pm8350.h>
281    #include <dt-bindings/interrupt-controller/irq.h>
282
283    pmic {
284        #address-cells = <1>;
285        #size-cells = <0>;
286
287        adc@3100 {
288            reg = <0x3100>;
289            compatible = "qcom,spmi-adc7";
290            #address-cells = <1>;
291            #size-cells = <0>;
292            #io-channel-cells = <1>;
293
294            /* Other properties are omitted */
295            channel@44 {
296                reg = <PMK8350_ADC7_AMUX_THM1_100K_PU>;
297                qcom,ratiometric;
298                qcom,hw-settle-time = <200>;
299                label = "xo_therm";
300            };
301
302            channel@47 {
303                reg = <PM8350_ADC7_AMUX_THM4_100K_PU(1)>;
304                qcom,ratiometric;
305                qcom,hw-settle-time = <200>;
306                label = "conn_therm";
307            };
308        };
309    };
310