Add support for AD4052 ADC Family

Documentation/ABI/testing/sysfs-bus-iio

@@ -139,6 +139,23 @@ Contact:	[email protected]
 Description:
 		Hardware dependent values supported by the oversampling filter.
 
+What:		/sys/bus/iio/devices/iio:deviceX/oversampling_frequency
+KernelVersion:	6.17
+Contact:	[email protected]
+Description:
+		Some devices have internal clocks for oversampling. Sets the
+		resulting frequency in Hz to trigger a conversion used by the
+		oversampling filter. If the device has a fixed internal clock
+		or is computed based on the sampling frequency parameter, the
+		parameter is read only.
+
+What:		/sys/bus/iio/devices/iio:deviceX/oversampling_frequency_available
+KernelVersion:	6.17
+Contact:	[email protected]
+Description:
+		Hardware dependent values supported by the oversampling
+		frequency.
+
 What:		/sys/bus/iio/devices/iio:deviceX/in_voltageY_raw
 What:		/sys/bus/iio/devices/iio:deviceX/in_voltageY_supply_raw
 KernelVersion:	2.6.35

Documentation/devicetree/bindings/iio/adc/adi,ad4052.yaml

@@ -0,0 +1,151 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+# Copyright 2025 Analog Devices Inc.
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/adc/adi,ad4052.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Analog Devices AD4052 ADC family device driver
+
+maintainers:
+  - Jorge Marques <[email protected]>
+
+description: |
+  Analog Devices AD4052 Single Channel Precision SAR ADC family
+
+  https://www.analog.com/media/en/technical-documentation/data-sheets/ad4050-ad4056.pdf
+  https://www.analog.com/media/en/technical-documentation/data-sheets/ad4052-ad4058.pdf
+
+properties:
+  compatible:
+    enum:
+      - adi,ad4050
+      - adi,ad4052
+      - adi,ad4056
+      - adi,ad4058
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    minItems: 1
+    maxItems: 2
+
+  interrupt-names:
+    items:
+      - const: gp0
+        description: Signal coming from the GP0 pin.
+      - const: gp1
+        description: Signal coming from the GP1 pin.
+
+  cnv-gpios:
+    description: The Convert Input (CNV). If omitted, CNV is tied to SPI CS.
+    maxItems: 1
+
+  pwms:
+    maxItems: 1
+    description: PWM connected to the CNV pin.
+
+  trigger-sources:
+    minItems: 1
+    maxItems: 2
+    description:
+      Describes the output pin and event associated.
+
+  "#trigger-source-cells":
+    const: 2
+    description: |
+      Output pins used as trigger source.
+
+      Cell 0 defines the event:
+      * 0 = Data ready
+      * 1 = Min threshold
+      * 2 = Max threshold
+      * 3 = Either threshold
+      * 4 = CHOP control
+      * 5 = Device enable
+      * 6 = Device ready (only GP1)
+
+      Cell 1 defines which pin:
+      * 0 = GP0
+      * 1 = GP1
+
+      For convenience, macros for these values are available in
+      dt-bindings/iio/adc/adi,ad4052.h.
+
+  spi-max-frequency:
+    maximum: 83333333
+
+  vdd-supply:
+    description: Analog power supply.
+
+  vio-supply:
+    description: Digital interface logic power supply.
+
+  ref-supply:
+    description:
+      Reference voltage to set the ADC full-scale range. If not present,
+      vdd-supply is used as the reference voltage.
+
+required:
+  - compatible
+  - reg
+  - vdd-supply
+  - vio-supply
+
+allOf:
+  - $ref: /schemas/spi/spi-peripheral-props.yaml#
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+    #include <dt-bindings/iio/adc/adi,ad4052.h>
+
+    spi {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        adc@0 {
+            compatible = "adi,ad4052";
+            reg = <0>;
+            vdd-supply = <&vdd>;
+            vio-supply = <&vio>;
+            ref-supply = <&ref>;
+            spi-max-frequency = <83333333>;
+
+            interrupt-parent = <&gpio>;
+            interrupts = <0 1 IRQ_TYPE_EDGE_FALLING>;
+            interrupt-names = "gp1";
+            cnv-gpios = <&gpio 2 GPIO_ACTIVE_HIGH>;
+        };
+    };
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+    #include <dt-bindings/iio/adc/adi,ad4052.h>
+
+    spi {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        trigger-sources = <&adc AD4052_TRIGGER_EVENT_DATA_READY
+                                AD4052_TRIGGER_PIN_GP1>;
+
+        adc@0 {
+            compatible = "adi,ad4052";
+            reg = <0>;
+            vdd-supply = <&vdd>;
+            vio-supply = <&vio>;
+            spi-max-frequency = <83333333>;
+            pwms = <&adc_trigger 0 10000 0>;
+
+            interrupt-parent = <&gpio>;
+            interrupts = <0 0 IRQ_TYPE_EDGE_RISING>,
+                         <0 1 IRQ_TYPE_EDGE_FALLING>;
+            interrupt-names = "gp0", "gp1";
+            cnv-gpios = <&gpio 2 GPIO_ACTIVE_HIGH>;
+        };
+    };

Documentation/iio/ad4052.rst

@@ -0,0 +1,139 @@
+.. SPDX-License-Identifier: GPL-2.0-only
+
+=============
+AD4052 driver
+=============
+
+ADC driver for Analog Devices Inc. AD4052 and similar devices. The module name
+is ``ad4052``.
+
+Supported devices
+=================
+
+The following chips are supported by this driver:
+
+* `AD4050 <https://www.analog.com/AD4050>`_
+* `AD4052 <https://www.analog.com/AD4052>`_
+* `AD4056 <https://www.analog.com/AD4056>`_
+* `AD4058 <https://www.analog.com/AD4058>`_
+
+Wiring modes
+============
+
+The ADC uses SPI 4-wire mode, and contain two programmable GPIOs and a CNV pin.
+
+The CNV pin is exposed as the ``cnv-gpios`` and triggers an ADC conversion. GP1
+is ADC conversion ready signal and GP0 Threshold event interrupt, both exposed
+as interrupts.
+
+Omit ``cnv-gpios`` and tie CNV and CS together to use the rising edge of the CS
+as the CNV signal.
+
+Device attributes
+=================
+
+The ADC contains only one channel with following attributes:
+
+.. list-table:: Channel attributes
+   :header-rows: 1
+
+   * - Attribute
+     - Description
+   * - ``in_voltage_calibscale``
+     - Scale factor to multiply the raw value.
+   * - ``in_voltage_raw``
+     - Raw ADC voltage value
+   * - ``in_voltage_oversampling_ratio``
+     - Enable the device's burst averaging mode to over sample using the
+       internal sample rate.
+   * - ``in_voltage_oversampling_ratio_available``
+     - List of available oversampling values. Value 1 disable the burst
+       averaging mode.
+   * - ``in_voltage_sampling_frequency``
+     - Set the sampling frequency, only present if SPI Offload is being used.
+
+Also contain the following device attributes:
+
+.. list-table:: Device attributes
+   :header-rows: 1
+
+   * - Attribute
+     - Description
+   * - ``oversamling_frequency``
+     - Frequency used in the burst averaging mode, sets the device internal
+       sample rate when the mode is activated.
+   * - ``oversampling_frequency_available``
+     - List of available sample rates.
+
+Interrupts
+==========
+
+The cell of trigger-sources of the parent node sets which GPIO has the role of
+data ready signal. If not present, defaults as ``gp0``. If not set in the
+``interrupt-names`` property, the driver will not wait for the data ready
+assertion, and will result in reading a sample before it's ready, particularly
+in oversampling mode.
+
+A second element in the ``interrupt-names`` property sets which GPIO has the
+role of the threshold event. If not provided, the IIO events attributes are
+still present, but no IIO Event will ever be triggered. This allows to use the
+GPIO output to trigger other resource.
+
+Low-power mode
+==============
+
+The device enters low-power mode on idle to save power. Enabling an event puts
+the device out of the low-power since the ADC autonomously samples to assert
+the event condition.
+
+SPI offload support
+===================
+
+To be able to achieve the maximum sample rate, the driver can be used with the
+`AXI SPI Engine`_ to provide SPI offload support.
+
+.. _AXI SPI Engine: http://analogdevicesinc.github.io/hdl/projects/ad4052_ardz/index.html
+
+When SPI offload is being used, additional attributes are present:
+
+.. list-table:: Additional attributes
+   :header-rows: 1
+
+   * - Attribute
+     - Description
+   * - ``in_voltage_sampling_frequency``
+     - Set the sampling frequency.
+
+Threshold events
+================
+
+The ADC supports a monitoring mode to raise threshold events. The driver
+supports a single interrupt for both rising and falling readings.
+
+The feature is enabled/disabled by setting ``thresh_either_en``. During monitor
+mode, the device continuously operates in autonomous mode until put back in
+configuration mode, due to this, the device returns busy until the feature is
+disabled.
+
+The following event attributes are available:
+
+.. list-table:: Event attributes
+   :header-rows: 1
+
+   * - Attribute
+     - Description
+   * - ``sampling_frequency``
+     - Frequency used in the monitoring mode, sets the device internal sample
+       rate when the mode is activated.
+   * - ``sampling_frequency_available``
+     - List of available sample rates.
+   * - ``thresh_either_en``
+     - Enable monitoring mode.
+   * - ``thresh_falling_hysteresis``
+     - Set the hysteresis value for the minimum threshold.
+   * - ``thresh_falling_value``
+     - Set the minimum threshold value.
+   * - ``thresh_rising_hysteresis``
+     - Set the hysteresis value for the maximum threshold.
+   * - ``thresh_rising_value``
+     - Set the maximum threshold value.

Documentation/iio/index.rst

@@ -22,6 +22,7 @@ Industrial I/O Kernel Drivers
    ad3552r
    ad4000
    ad4030
+   ad4052
    ad4695
    ad7191
    ad7380

MAINTAINERS

@@ -1374,6 +1374,14 @@ F:	Documentation/devicetree/bindings/iio/adc/adi,ad4030.yaml
 F:	Documentation/iio/ad4030.rst
 F:	drivers/iio/adc/ad4030.c
 
+ANALOG DEVICES INC AD4052 DRIVER
+M:	Jorge Marques <[email protected]>
+S:	Supported
+W:	https://ez.analog.com/linux-software-drivers
+F:	Documentation/devicetree/bindings/iio/adc/adi,ad4052.yaml
+F:	Documentation/iio/ad4052.rst
+F:	drivers/iio/adc/ad4052.c
+
 ANALOG DEVICES INC AD4080 DRIVER
 M:	Antoniu Miclaus <[email protected]>
 L:	[email protected]

drivers/iio/adc/Kconfig

@@ -57,6 +57,21 @@ config AD4030
 	  To compile this driver as a module, choose M here: the module will be
 	  called ad4030.
 
+config AD4052
+	tristate "Analog Devices AD4052 Driver"
+	depends on SPI
+	depends on GPIOLIB
+	select SPI_OFFLOAD
+	select IIO_BUFFER
+	select IIO_BUFFER_DMAENGINE
+	select REGMAP_SPI
+	help
+	  Say yes here to build support for Analog Devices AD4052 SPI analog
+	  to digital converters (ADC).
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called ad4052.
+
 config AD4080
 	tristate "Analog Devices AD4080 high speed ADC"
 	depends on SPI

drivers/iio/adc/Makefile

@@ -10,6 +10,7 @@ obj-$(CONFIG_AB8500_GPADC) += ab8500-gpadc.o
 obj-$(CONFIG_AD_SIGMA_DELTA) += ad_sigma_delta.o
 obj-$(CONFIG_AD4000) += ad4000.o
 obj-$(CONFIG_AD4030) += ad4030.o
+obj-$(CONFIG_AD4052) += ad4052.o
 obj-$(CONFIG_AD4080) += ad4080.o
 obj-$(CONFIG_AD4130) += ad4130.o
 obj-$(CONFIG_AD4170_4) += ad4170-4.o