xref: /linux/Documentation/devicetree/bindings/iio/adc/qcom,pm8018-adc.yaml (revision 58f6259b7a08f8d47d4629609703d358b042f0fd) 
1# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
2%YAML 1.2
3---
4$id: http://devicetree.org/schemas/iio/adc/qcom,pm8018-adc.yaml#
5$schema: http://devicetree.org/meta-schemas/core.yaml#
6
7title: Qualcomm's PM8xxx voltage XOADC
8
9maintainers:
10  - Linus Walleij <linus.walleij@linaro.org>
11
12description: |
13  The Qualcomm PM8xxx PMICs contain a HK/XO ADC (Housekeeping/Crystal
14  oscillator ADC) encompassing PM8018, PM8038, PM8058 and PM8921.
15
16properties:
17  compatible:
18    enum:
19      - qcom,pm8018-adc
20      - qcom,pm8038-adc
21      - qcom,pm8058-adc
22      - qcom,pm8921-adc
23
24  reg:
25    maxItems: 1
26    description:
27      ADC base address in the PMIC, typically 0x197.
28
29  xoadc-ref-supply:
30    description:
31      The reference voltage may vary with PMIC variant but is typically
32      something like 2.2 or 1.8V.
33
34  interrupts:
35    maxItems: 1
36
37  "#address-cells":
38    const: 2
39    description:
40      The first cell is the prescaler (on PM8058) or premux (on PM8921)
41      with two valid bits  so legal values are 0x00, 0x01 or 0x02.
42      The second cell is the main analog mux setting (0x00..0x0f).
43      The combination of prescaler/premux and analog mux uniquely addresses
44      a hardware channel on all systems.
45
46  "#size-cells":
47    const: 0
48
49  "#io-channel-cells":
50    const: 2
51    description:
52      The cells are precaler or premux followed by the analog muxing line.
53
54additionalProperties: false
55
56required:
57  - compatible
58  - reg
59  - "#io-channel-cells"
60  - "#address-cells"
61  - "#size-cells"
62  - adc-channel@c
63  - adc-channel@d
64  - adc-channel@f
65
66patternProperties:
67  "^(adc-channel@)[0-9a-f]$":
68    type: object
69    description: |
70      ADC channel specific configuration.
71      Note that channels c, d and f must be present for calibration.
72      These three nodes are used for absolute and ratiometric calibration
73      and only need to have these reg values: they are by hardware definition
74      1:1 ratio converters that sample 625, 1250 and 0 milliV and create
75      an interpolation calibration for all other ADCs.
76
77    properties:
78      reg:
79        maxItems: 1
80
81      qcom,decimation:
82        $ref: /schemas/types.yaml#/definitions/uint32
83        description: |
84          This parameter is used to decrease the ADC sampling rate.
85          Quicker measurements can be made by reducing the decimation ratio.
86          Valid values are 512, 1024, 2048, 4096.
87          If the property is not found, a default value of 512 will be used.
88
89      qcom,ratiometric:
90        $ref: /schemas/types.yaml#/definitions/uint32
91        description: |
92          Channel calibration type. If this property is specified
93          VADC will use a special voltage references for channel
94          calibration. The available references are specified in the
95          as a u32 value setting (see below) and it is compulsory
96          to also specify this reference if ratiometric calibration
97          is selected.
98
99          If the property is not found, the channel will be
100          calibrated with the 0.625V and 1.25V reference channels, also
101          known as an absolute calibration.
102
103          The reference voltage pairs when using ratiometric calibration:
104          0 = XO_IN/XOADC_GND
105          1 = PMIC_IN/XOADC_GND
106          2 = PMIC_IN/BMS_CSP
107          3 (invalid)
108          4 = XOADC_GND/XOADC_GND
109          5 = XOADC_VREF/XOADC_GND
110
111    additionalProperties: false
112
113    required:
114      - reg
115
116examples:
117  - |
118    #include <dt-bindings/interrupt-controller/irq.h>
119    pmic {
120        #address-cells = <1>;
121        #size-cells = <0>;
122
123        adc@197 {
124            compatible = "qcom,pm8058-adc";
125            reg = <0x197>;
126            interrupts-extended = <&pm8058 76 IRQ_TYPE_EDGE_RISING>;
127            #address-cells = <2>;
128            #size-cells = <0>;
129            #io-channel-cells = <2>;
130
131            vcoin: adc-channel@0 {
132                reg = <0x00 0x00>;
133            };
134            vbat: adc-channel@1 {
135                reg = <0x00 0x01>;
136            };
137            dcin: adc-channel@2 {
138                reg = <0x00 0x02>;
139            };
140            ichg: adc-channel@3 {
141                reg = <0x00 0x03>;
142            };
143            vph_pwr: adc-channel@4 {
144                reg = <0x00 0x04>;
145            };
146            usb_vbus: adc-channel@a {
147                reg = <0x00 0x0a>;
148            };
149            die_temp: adc-channel@b {
150                reg = <0x00 0x0b>;
151            };
152            ref_625mv: adc-channel@c {
153                reg = <0x00 0x0c>;
154            };
155            ref_1250mv: adc-channel@d {
156                reg = <0x00 0x0d>;
157            };
158            ref_325mv: adc-channel@e {
159                reg = <0x00 0x0e>;
160            };
161            ref_muxoff: adc-channel@f {
162                reg = <0x00 0x0f>;
163            };
164        };
165    };
166...
167