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