1 Qualcomm's PM8xxx voltage XOADC
3 The Qualcomm PM8xxx PMICs contain a HK/XO ADC (Housekeeping/Crystal
4 oscillator ADC) encompassing PM8018, PM8038, PM8058 and PM8921.
8 - compatible: should be one of:
14 - reg: should contain the ADC base address in the PMIC, typically
17 - xoadc-ref-supply: should reference a regulator that can supply
18 a reference voltage on demand. The reference voltage may vary
19 with PMIC variant but is typically something like 2.2 or 1.8V.
21 The following required properties are standard for IO channels, see
22 iio-bindings.txt for more details:
24 - #address-cells: should be set to <1>
26 - #size-cells: should be set to <0>
28 - #io-channel-cells: should be set to <1>
30 - interrupts: should refer to the parent PMIC interrupt controller
31 and reference the proper ADC interrupt.
35 The ADC channels are configured as subnodes of the ADC. Since some of
36 them are used for calibrating the ADC, these nodes are compulsory:
50 These three nodes are used for absolute and ratiometric calibration
51 and only need to have these reg values: they are by hardware definition
52 1:1 ratio converters that sample 625, 1250 and 0 milliV and create
53 an interpolation calibration for all other ADCs.
55 Optional subnodes: any channels other than channel 0x0c, 0x0d and
58 Required channel node properties:
60 - reg: should contain the hardware channel number in the range
61 0 .. 0x0f (4 bits). The hardware only supports 16 channels.
63 Optional channel node properties:
67 Definition: This parameter is used to decrease the ADC sampling rate.
68 Quicker measurements can be made by reducing the decimation ratio.
69 Valid values are 512, 1024, 2048, 4096.
70 If the property is not found, a default value of 512 will be used.
74 Definition: Channel calibration type. If this property is specified
75 VADC will use a special voltage references for channel
76 calibration. The available references are specified in the
77 as a u32 value setting (see below) and it is compulsory
78 to also specify this reference if ratiometric calibration
81 If the property is not found, the channel will be
82 calibrated with the 0.625V and 1.25V reference channels, also
83 known as an absolute calibration.
84 The reference voltage pairs when using ratiometric calibration:
89 4 = XOADC_GND/XOADC_GND
90 5 = XOADC_VREF/XOADC_GND
95 compatible = "qcom,pm8058-adc";
97 interrupt-parent = <&pm8058>;
101 #io-channel-cells = <1>;
103 vcoin: adc-channel@0 {
106 vbat: adc-channel@1 {
109 dcin: adc-channel@2 {
112 ichg: adc-channel@3 {
115 vph_pwr: adc-channel@4 {
118 usb_vbus: adc-channel@a {
121 die_temp: adc-channel@b {
124 ref_625mv: adc-channel@c {
127 ref_1250mv: adc-channel@d {
130 ref_325mv: adc-channel@e {
133 ref_muxoff: adc-channel@f {
139 /* IIO client node */
141 compatible = "iio-hwmon";
142 io-channels = <&xoadc 0x01>, /* Battery */
143 <&xoadc 0x02>, /* DC in (charger) */
144 <&xoadc 0x04>, /* VPH the main system voltage */
145 <&xoadc 0x0b>, /* Die temperature */
146 <&xoadc 0x0c>, /* Reference voltage 1.25V */
147 <&xoadc 0x0d>, /* Reference voltage 0.625V */
148 <&xoadc 0x0e>; /* Reference voltage 0.325V */