0001 # SPDX-License-Identifier: GPL-2.0-only
0002 %YAML 1.2
0003 ---
0004 $id: http://devicetree.org/schemas/iio/adc/qcom,spmi-vadc.yaml#
0005 $schema: http://devicetree.org/meta-schemas/core.yaml#
0006
0007 title: Qualcomm's SPMI PMIC ADC
0008
0009 maintainers:
0010 - Andy Gross <agross@kernel.org>
0011 - Bjorn Andersson <bjorn.andersson@linaro.org>
0012
0013 description: |
0014 SPMI PMIC voltage ADC (VADC) provides interface to clients to read
0015 voltage. The VADC is a 15-bit sigma-delta ADC.
0016 SPMI PMIC5/PMIC7 voltage ADC (ADC) provides interface to clients to read
0017 voltage. The VADC is a 16-bit sigma-delta ADC.
0018
0019 properties:
0020 compatible:
0021 oneOf:
0022 - items:
0023 - const: qcom,pms405-adc
0024 - const: qcom,spmi-adc-rev2
0025
0026 - items:
0027 - enum:
0028 - qcom,spmi-vadc
0029 - qcom,spmi-adc5
0030 - qcom,spmi-adc-rev2
0031 - qcom,spmi-adc7
0032
0033 reg:
0034 description: VADC base address in the SPMI PMIC register map
0035 maxItems: 1
0036
0037 '#address-cells':
0038 const: 1
0039
0040 '#size-cells':
0041 const: 0
0042
0043 '#io-channel-cells':
0044 const: 1
0045
0046 interrupts:
0047 maxItems: 1
0048 description:
0049 End of conversion interrupt.
0050
0051 required:
0052 - compatible
0053 - reg
0054 - '#address-cells'
0055 - '#size-cells'
0056 - '#io-channel-cells'
0057
0058 patternProperties:
0059 "^.*@[0-9a-f]+$":
0060 type: object
0061 description: |
0062 Represents the external channels which are connected to the ADC.
0063 For compatible property "qcom,spmi-vadc" following channels, also known as
0064 reference point channels, are used for result calibration and their channel
0065 configuration nodes should be defined:
0066 VADC_REF_625MV and/or VADC_SPARE1(based on PMIC version) VADC_REF_1250MV,
0067 VADC_GND_REF and VADC_VDD_VADC.
0068
0069 properties:
0070 reg:
0071 maxItems: 1
0072 description: |
0073 ADC channel number.
0074 See include/dt-bindings/iio/qcom,spmi-vadc.h
0075 For PMIC7 ADC, the channel numbers are specified separately per PMIC
0076 in the PMIC-specific files in include/dt-bindings/iio/.
0077
0078 label:
0079 $ref: /schemas/types.yaml#/definitions/string
0080 description: |
0081 ADC input of the platform as seen in the schematics.
0082 For thermistor inputs connected to generic AMUX or GPIO inputs
0083 these can vary across platform for the same pins. Hence select
0084 the platform schematics name for this channel.
0085
0086 qcom,decimation:
0087 $ref: /schemas/types.yaml#/definitions/uint32
0088 description: |
0089 This parameter is used to decrease ADC sampling rate.
0090 Quicker measurements can be made by reducing decimation ratio.
0091
0092 qcom,pre-scaling:
0093 description: |
0094 Used for scaling the channel input signal before the signal is
0095 fed to VADC. The configuration for this node is to know the
0096 pre-determined ratio and use it for post scaling. It is a pair of
0097 integers, denoting the numerator and denominator of the fraction by which
0098 input signal is multiplied. For example, <1 3> indicates the signal is scaled
0099 down to 1/3 of its value before ADC measurement.
0100 If property is not found default value depending on chip will be used.
0101 $ref: /schemas/types.yaml#/definitions/uint32-array
0102 oneOf:
0103 - items:
0104 - const: 1
0105 - enum: [ 1, 3, 4, 6, 20, 8, 10 ]
0106 - items:
0107 - const: 10
0108 - const: 81
0109
0110 qcom,ratiometric:
0111 description: |
0112 Channel calibration type.
0113 - For compatible property "qcom,spmi-vadc", if this property is
0114 specified VADC will use the VDD reference (1.8V) and GND for
0115 channel calibration. If property is not found, channel will be
0116 calibrated with 0.625V and 1.25V reference channels, also
0117 known as absolute calibration.
0118 - For compatible property "qcom,spmi-adc5", "qcom,spmi-adc7" and
0119 "qcom,spmi-adc-rev2", if this property is specified VADC will use
0120 the VDD reference (1.875V) and GND for channel calibration. If
0121 property is not found, channel will be calibrated with 0V and 1.25V
0122 reference channels, also known as absolute calibration.
0123 type: boolean
0124
0125 qcom,hw-settle-time:
0126 $ref: /schemas/types.yaml#/definitions/uint32
0127 description: |
0128 Time between AMUX getting configured and the ADC starting
0129 conversion. The 'hw_settle_time' is an index used from valid values
0130 and programmed in hardware to achieve the hardware settling delay.
0131
0132 qcom,avg-samples:
0133 $ref: /schemas/types.yaml#/definitions/uint32
0134 description: |
0135 Number of samples to be used for measurement.
0136 Averaging provides the option to obtain a single measurement
0137 from the ADC that is an average of multiple samples. The value
0138 selected is 2^(value).
0139
0140 required:
0141 - reg
0142
0143 allOf:
0144 - if:
0145 properties:
0146 compatible:
0147 contains:
0148 const: qcom,spmi-vadc
0149
0150 then:
0151 patternProperties:
0152 "^.*@[0-9a-f]+$":
0153 properties:
0154 qcom,decimation:
0155 enum: [ 512, 1024, 2048, 4096 ]
0156 default: 512
0157
0158 qcom,hw-settle-time:
0159 enum: [ 0, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1, 2,
0160 4, 6, 8, 10 ]
0161 default: 0
0162
0163 qcom,avg-samples:
0164 enum: [ 1, 2, 4, 8, 16, 32, 64, 128, 256, 512 ]
0165 default: 1
0166
0167 - if:
0168 properties:
0169 compatible:
0170 contains:
0171 const: qcom,spmi-adc-rev2
0172
0173 then:
0174 patternProperties:
0175 "^.*@[0-9a-f]+$":
0176 properties:
0177 qcom,decimation:
0178 enum: [ 256, 512, 1024 ]
0179 default: 1024
0180
0181 qcom,hw-settle-time:
0182 enum: [ 0, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1, 2,
0183 4, 6, 8, 10 ]
0184 default: 0
0185
0186 qcom,avg-samples:
0187 enum: [ 1, 2, 4, 8, 16 ]
0188 default: 1
0189
0190 - if:
0191 properties:
0192 compatible:
0193 contains:
0194 const: qcom,spmi-adc5
0195
0196 then:
0197 patternProperties:
0198 "^.*@[0-9a-f]+$":
0199 properties:
0200 qcom,decimation:
0201 enum: [ 250, 420, 840 ]
0202 default: 840
0203
0204 qcom,hw-settle-time:
0205 enum: [ 15, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1, 2,
0206 4, 6, 8, 10, 16, 32, 64, 128 ]
0207 default: 15
0208
0209 qcom,avg-samples:
0210 enum: [ 1, 2, 4, 8, 16 ]
0211 default: 1
0212
0213 - if:
0214 properties:
0215 compatible:
0216 contains:
0217 const: qcom,spmi-adc7
0218
0219 then:
0220 patternProperties:
0221 "^.*@[0-9a-f]+$":
0222 properties:
0223 qcom,decimation:
0224 enum: [ 85, 340, 1360 ]
0225 default: 1360
0226
0227 qcom,hw-settle-time:
0228 enum: [ 15, 100, 200, 300, 400, 500, 600, 700, 1000, 2000, 4000,
0229 8000, 16000, 32000, 64000, 128000 ]
0230 default: 15
0231
0232 qcom,avg-samples:
0233 enum: [ 1, 2, 4, 8, 16 ]
0234 default: 1
0235
0236 additionalProperties: false
0237
0238 examples:
0239 - |
0240 spmi_bus {
0241 #address-cells = <1>;
0242 #size-cells = <0>;
0243 /* VADC node */
0244 pmic_vadc: adc@3100 {
0245 compatible = "qcom,spmi-vadc";
0246 reg = <0x3100>;
0247 interrupts = <0x0 0x31 0x0 0x1>;
0248 #address-cells = <1>;
0249 #size-cells = <0>;
0250 #io-channel-cells = <1>;
0251
0252 /* Channel node */
0253 adc-chan@39 {
0254 reg = <0x39>;
0255 qcom,decimation = <512>;
0256 qcom,ratiometric;
0257 qcom,hw-settle-time = <200>;
0258 qcom,avg-samples = <1>;
0259 qcom,pre-scaling = <1 3>;
0260 };
0261
0262 adc-chan@9 {
0263 reg = <0x9>;
0264 };
0265
0266 adc-chan@a {
0267 reg = <0xa>;
0268 };
0269
0270 adc-chan@e {
0271 reg = <0xe>;
0272 };
0273
0274 adc-chan@f {
0275 reg = <0xf>;
0276 };
0277 };
0278 };
