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        allOf:
101          - $ref: /schemas/types.yaml#/definitions/uint32-array
102        oneOf:
103          - items:
104            - const: 1
105            - enum: [ 1, 3, 4, 6, 20, 8, 10 ]
106
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
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        io-channel-ranges;
251
252        /* Channel node */
253        adc-chan@39 {
254          reg = <0x39>;
255          qcom,decimation = <512>;
256          qcom,ratiometric;
257          qcom,hw-settle-time = <200>;
258          qcom,avg-samples = <1>;
259          qcom,pre-scaling = <1 3>;
260        };
261
262        adc-chan@9 {
263          reg = <0x9>;
264        };
265
266        adc-chan@a {
267          reg = <0xa>;
268        };
269
270        adc-chan@e {
271          reg = <0xe>;
272        };
273
274        adc-chan@f {
275          reg = <0xf>;
276        };
277      };
278    };
279