This adds a new binding for the Analog Devices, Inc. AD7944, AD7985, and AD7986 ADCs. Signed-off-by: David Lechner <dlechner@xxxxxxxxxxxx> --- .../devicetree/bindings/iio/adc/adi,ad7944.yaml | 204 +++++++++++++++++++++ MAINTAINERS | 8 + 2 files changed, 212 insertions(+) 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 000000000000..61ee81326660 --- /dev/null +++ b/Documentation/devicetree/bindings/iio/adc/adi,ad7944.yaml @@ -0,0 +1,204 @@ +# 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@xxxxxxxxxx> + - Nuno Sá <nuno.sa@xxxxxxxxxx> + +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, multi, chain ] + default: multi + description: | + * single: The datasheet calls this "3-wire mode". It 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. + * multi: The datasheet calls this "4-wire mode". This is the convential + 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. + * 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 is unused. + + 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 'single' mode, cnv-gpios is optional, for other modes it is required + - if: + required: + - adi,spi-mode + then: + if: + properties: + adi,spi-mode: + enum: [ multi, chain ] + then: + required: + - cnv-gpios + else: + 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 + # 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>; + }; + }; diff --git a/MAINTAINERS b/MAINTAINERS index 00d354af10f5..4f1e658e1e0d 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -451,6 +451,14 @@ W: http://wiki.analog.com/AD7879 W: https://ez.analog.com/linux-software-drivers F: drivers/input/touchscreen/ad7879.c +AD7944 ADC DRIVER (AD7944/AD7985/AD7986) +M: Michael Hennerich <michael.hennerich@xxxxxxxxxx> +M: Nuno Sá <nuno.sa@xxxxxxxxxx> +R: David Lechner <dlechner@xxxxxxxxxxxx> +S: Supported +W: https://ez.analog.com/linux-software-drivers +F: Documentation/devicetree/bindings/iio/adc/adi,ad7944.yaml + ADAFRUIT MINI I2C GAMEPAD M: Anshul Dalal <anshulusr@xxxxxxxxx> L: linux-input@xxxxxxxxxxxxxxx -- 2.43.2
