Documentation/devicetree/bindings/iio/adc/adi,ad7944.yaml - linux - Git at Google

 # 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>;
         };
     };
	# 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>;
	};
	};