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diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ad7944.yaml b/Documentation/devicetree/bindings/iio/adc/adi,ad7944.yaml new file mode 100644 index 0000000000..d17d184842 --- /dev/null +++ b/Documentation/devicetree/bindings/iio/adc/adi,ad7944.yaml @@ -0,0 +1,213 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/iio/adc/adi,ad7944.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Analog Devices PulSAR LFCSP Analog to Digital Converters + +maintainers: + - Michael Hennerich <Michael.Hennerich@analog.com> + - Nuno Sá <nuno.sa@analog.com> + +description: | + A family of pin-compatible single channel differential analog to digital + converters with SPI support in a LFCSP package. + + * https://www.analog.com/en/products/ad7944.html + * https://www.analog.com/en/products/ad7985.html + * https://www.analog.com/en/products/ad7986.html + +$ref: /schemas/spi/spi-peripheral-props.yaml# + +properties: + compatible: + enum: + - adi,ad7944 + - adi,ad7985 + - adi,ad7986 + + reg: + maxItems: 1 + + spi-max-frequency: + maximum: 111111111 + + spi-cpol: true + spi-cpha: true + + adi,spi-mode: + $ref: /schemas/types.yaml#/definitions/string + enum: [ single, chain ] + description: | + This property indicates the SPI wiring configuration. + + When this property is omitted, it is assumed that the device is using what + the datasheet calls "4-wire mode". This is the conventional SPI mode used + when there are multiple devices on the same bus. In this mode, the CNV + line is used to initiate the conversion and the SDI line is connected to + CS on the SPI controller. + + When this property is present, it indicates that the device is using one + of the following alternative wiring configurations: + + * single: The datasheet calls this "3-wire mode". (NOTE: The datasheet's + definition of 3-wire mode is NOT at all related to the standard + spi-3wire property!) This mode is often used when the ADC is the only + device on the bus. In this mode, SDI is tied to VIO, and the CNV line + can be connected to the CS line of the SPI controller or to a GPIO, in + which case the CS line of the controller is unused. + * chain: The datasheet calls this "chain mode". This mode is used to save + on wiring when multiple ADCs are used. In this mode, the SDI line of + one chip is tied to the SDO of the next chip in the chain and the SDI of + the last chip in the chain is tied to GND. Only the first chip in the + chain is connected to the SPI bus. The CNV line of all chips are tied + together. The CS line of the SPI controller can be used as the CNV line + only if it is active high. + + '#daisy-chained-devices': true + + avdd-supply: + description: A 2.5V supply that powers the analog circuitry. + + dvdd-supply: + description: A 2.5V supply that powers the digital circuitry. + + vio-supply: + description: + A 1.8V to 2.7V supply for the digital inputs and outputs. + + bvdd-supply: + description: + A voltage supply for the buffered power. When using an external reference + without an internal buffer (PDREF high, REFIN low), this should be + connected to the same supply as ref-supply. Otherwise, when using an + internal reference or an external reference with an internal buffer, this + is connected to a 5V supply. + + ref-supply: + description: + Voltage regulator for the external reference voltage (REF). This property + is omitted when using an internal reference. + + refin-supply: + description: + Voltage regulator for the reference buffer input (REFIN). When using an + external buffer with internal reference, this should be connected to a + 1.2V external reference voltage supply. Otherwise, this property is + omitted. + + cnv-gpios: + description: + The Convert Input (CNV). This input has multiple functions. It initiates + the conversions and selects the SPI mode of the device (chain or CS). In + 'single' mode, this property is omitted if the CNV pin is connected to the + CS line of the SPI controller. + maxItems: 1 + + turbo-gpios: + description: + GPIO connected to the TURBO line. If omitted, it is assumed that the TURBO + line is hard-wired and the state is determined by the adi,always-turbo + property. + maxItems: 1 + + adi,always-turbo: + type: boolean + description: + When present, this property indicates that the TURBO line is hard-wired + and the state is always high. If neither this property nor turbo-gpios is + present, the TURBO line is assumed to be hard-wired and the state is + always low. + + interrupts: + description: + The SDO pin can also function as a busy indicator. This node should be + connected to an interrupt that is triggered when the SDO line goes low + while the SDI line is high and the CNV line is low ('single' mode) or the + SDI line is low and the CNV line is high ('multi' mode); or when the SDO + line goes high while the SDI and CNV lines are high (chain mode), + maxItems: 1 + +required: + - compatible + - reg + - avdd-supply + - dvdd-supply + - vio-supply + - bvdd-supply + +allOf: + # ref-supply and refin-supply are mutually exclusive (neither is also valid) + - if: + required: + - ref-supply + then: + properties: + refin-supply: false + - if: + required: + - refin-supply + then: + properties: + ref-supply: false + # in '4-wire' mode, cnv-gpios is required, for other modes it is optional + - if: + not: + required: + - adi,spi-mode + then: + required: + - cnv-gpios + # chain mode has lower SCLK max rate and doesn't work when TURBO is enabled + - if: + required: + - adi,spi-mode + properties: + adi,spi-mode: + const: chain + then: + properties: + spi-max-frequency: + maximum: 90909090 + adi,always-turbo: false + required: + - '#daisy-chained-devices' + else: + properties: + '#daisy-chained-devices': false + # turbo-gpios and adi,always-turbo are mutually exclusive + - if: + required: + - turbo-gpios + then: + properties: + adi,always-turbo: false + - if: + required: + - adi,always-turbo + then: + properties: + turbo-gpios: false + +unevaluatedProperties: false + +examples: + - | + #include <dt-bindings/gpio/gpio.h> + spi { + #address-cells = <1>; + #size-cells = <0>; + adc@0 { + compatible = "adi,ad7944"; + reg = <0>; + spi-cpha; + spi-max-frequency = <111111111>; + avdd-supply = <&supply_2_5V>; + dvdd-supply = <&supply_2_5V>; + vio-supply = <&supply_1_8V>; + bvdd-supply = <&supply_5V>; + cnv-gpios = <&gpio 0 GPIO_ACTIVE_HIGH>; + turbo-gpios = <&gpio 1 GPIO_ACTIVE_HIGH>; + }; + }; |