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    additionalProperties: false
62    description: |
63      Represents the external channels which are connected to the ADC.
64      For compatible property "qcom,spmi-vadc" following channels, also known as
65      reference point channels, are used for result calibration and their channel
66      configuration nodes should be defined:
67      VADC_REF_625MV and/or VADC_SPARE1(based on PMIC version) VADC_REF_1250MV,
68      VADC_GND_REF and VADC_VDD_VADC.
69
70    properties:
71      reg:
72        maxItems: 1
73        description: |
74          ADC channel number.
75          See include/dt-bindings/iio/qcom,spmi-vadc.h
76          For PMIC7 ADC, the channel numbers are specified separately per PMIC
77          in the PMIC-specific files in include/dt-bindings/iio/.
78
79      label:
80        $ref: /schemas/types.yaml#/definitions/string
81        description: |
82            ADC input of the platform as seen in the schematics.
83            For thermistor inputs connected to generic AMUX or GPIO inputs
84            these can vary across platform for the same pins. Hence select
85            the platform schematics name for this channel.
86
87      qcom,decimation:
88        $ref: /schemas/types.yaml#/definitions/uint32
89        description: |
90            This parameter is used to decrease ADC sampling rate.
91            Quicker measurements can be made by reducing decimation ratio.
92
93      qcom,pre-scaling:
94        description: |
95            Used for scaling the channel input signal before the signal is
96            fed to VADC. The configuration for this node is to know the
97            pre-determined ratio and use it for post scaling. It is a pair of
98            integers, denoting the numerator and denominator of the fraction by which
99            input signal is multiplied. For example, <1 3> indicates the signal is scaled
100            down to 1/3 of its value before ADC measurement.
101            If property is not found default value depending on chip will be used.
102        $ref: /schemas/types.yaml#/definitions/uint32-array
103        oneOf:
104          - items:
105              - const: 1
106              - enum: [ 1, 3, 4, 6, 20, 8, 10 ]
107          - items:
108              - const: 10
109              - const: 81
110
111      qcom,ratiometric:
112        description: |
113            Channel calibration type.
114            - For compatible property "qcom,spmi-vadc", if this property is
115              specified VADC will use the VDD reference (1.8V) and GND for
116              channel calibration. If property is not found, channel will be
117              calibrated with 0.625V and 1.25V reference channels, also
118              known as absolute calibration.
119            - For compatible property "qcom,spmi-adc5", "qcom,spmi-adc7" and
120              "qcom,spmi-adc-rev2", if this property is specified VADC will use
121              the VDD reference (1.875V) and GND for channel calibration. If
122              property is not found, channel will be calibrated with 0V and 1.25V
123              reference channels, also known as absolute calibration.
124        type: boolean
125
126      qcom,hw-settle-time:
127        $ref: /schemas/types.yaml#/definitions/uint32
128        description: |
129            Time between AMUX getting configured and the ADC starting
130            conversion. The 'hw_settle_time' is an index used from valid values
131            and programmed in hardware to achieve the hardware settling delay.
132
133      qcom,avg-samples:
134        $ref: /schemas/types.yaml#/definitions/uint32
135        description: |
136            Number of samples to be used for measurement.
137            Averaging provides the option to obtain a single measurement
138            from the ADC that is an average of multiple samples. The value
139            selected is 2^(value).
140
141    required:
142      - reg
143
144allOf:
145  - if:
146      properties:
147        compatible:
148          contains:
149            const: qcom,spmi-vadc
150
151    then:
152      patternProperties:
153        "^.*@[0-9a-f]+$":
154          properties:
155            qcom,decimation:
156              enum: [ 512, 1024, 2048, 4096 ]
157              default: 512
158
159            qcom,hw-settle-time:
160              enum: [ 0, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1, 2,
161                      4, 6, 8, 10 ]
162              default: 0
163
164            qcom,avg-samples:
165              enum: [ 1, 2, 4, 8, 16, 32, 64, 128, 256, 512 ]
166              default: 1
167
168  - if:
169      properties:
170        compatible:
171          contains:
172            const: qcom,spmi-adc-rev2
173
174    then:
175      patternProperties:
176        "^.*@[0-9a-f]+$":
177          properties:
178            qcom,decimation:
179              enum: [ 256, 512, 1024 ]
180              default: 1024
181
182            qcom,hw-settle-time:
183              enum: [ 0, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1, 2,
184                      4, 6, 8, 10 ]
185              default: 0
186
187            qcom,avg-samples:
188              enum: [ 1, 2, 4, 8, 16 ]
189              default: 1
190
191  - if:
192      properties:
193        compatible:
194          contains:
195            const: qcom,spmi-adc5
196
197    then:
198      patternProperties:
199        "^.*@[0-9a-f]+$":
200          properties:
201            qcom,decimation:
202              enum: [ 250, 420, 840 ]
203              default: 840
204
205            qcom,hw-settle-time:
206              enum: [ 15, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1, 2,
207                      4, 6, 8, 10, 16, 32, 64, 128 ]
208              default: 15
209
210            qcom,avg-samples:
211              enum: [ 1, 2, 4, 8, 16 ]
212              default: 1
213
214  - if:
215      properties:
216        compatible:
217          contains:
218            const: qcom,spmi-adc7
219
220    then:
221      patternProperties:
222        "^.*@[0-9a-f]+$":
223          properties:
224            qcom,decimation:
225              enum: [ 85, 340, 1360 ]
226              default: 1360
227
228            qcom,hw-settle-time:
229              enum: [ 15, 100, 200, 300, 400, 500, 600, 700, 1000, 2000, 4000,
230                      8000, 16000, 32000, 64000, 128000 ]
231              default: 15
232
233            qcom,avg-samples:
234              enum: [ 1, 2, 4, 8, 16 ]
235              default: 1
236
237additionalProperties: false
238
239examples:
240  - |
241    spmi_bus {
242      #address-cells = <1>;
243      #size-cells = <0>;
244      /* VADC node */
245      pmic_vadc: adc@3100 {
246        compatible = "qcom,spmi-vadc";
247        reg = <0x3100>;
248        interrupts = <0x0 0x31 0x0 0x1>;
249        #address-cells = <1>;
250        #size-cells = <0>;
251        #io-channel-cells = <1>;
252
253        /* Channel node */
254        adc-chan@39 {
255          reg = <0x39>;
256          qcom,decimation = <512>;
257          qcom,ratiometric;
258          qcom,hw-settle-time = <200>;
259          qcom,avg-samples = <1>;
260          qcom,pre-scaling = <1 3>;
261        };
262
263        adc-chan@9 {
264          reg = <0x9>;
265        };
266
267        adc-chan@a {
268          reg = <0xa>;
269        };
270
271        adc-chan@e {
272          reg = <0xe>;
273        };
274
275        adc-chan@f {
276          reg = <0xf>;
277        };
278      };
279    };
280