[PATCH v3 1/4] dt-bindings: iio: adc: add bindings for AD4691 family
From: Radu Sabau via B4 Relay
Date: Fri Mar 13 2026 - 06:08:22 EST
From: Radu Sabau <radu.sabau@xxxxxxxxxx>
Add DT bindings for the Analog Devices AD4691 family of multichannel
SAR ADCs (AD4691, AD4692, AD4693, AD4694).
The binding describes the hardware connections: an optional PWM on
the CNV pin selects CNV Clock Mode; when absent, Manual Mode is used
with CNV tied to SPI CS. GPIO pins, voltage supplies, and the
trigger-source interface for SPI Engine offload operation are also
described.
Signed-off-by: Radu Sabau <radu.sabau@xxxxxxxxxx>
---
.../devicetree/bindings/iio/adc/adi,ad4691.yaml | 180 +++++++++++++++++++++
MAINTAINERS | 8 +
include/dt-bindings/iio/adc/adi,ad4691.h | 13 ++
3 files changed, 201 insertions(+)
diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ad4691.yaml b/Documentation/devicetree/bindings/iio/adc/adi,ad4691.yaml
new file mode 100644
index 000000000000..a9301e0ca851
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/adc/adi,ad4691.yaml
@@ -0,0 +1,180 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/adc/adi,ad4691.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Analog Devices AD4691 Family Multichannel SAR ADCs
+
+maintainers:
+ - Radu Sabau <radu.sabau@xxxxxxxxxx>
+
+description: |
+ The AD4691 family are high-speed, low-power, multichannel successive
+ approximation register (SAR) analog-to-digital converters (ADCs) with
+ an SPI-compatible serial interface. The ADC supports CNV Clock Mode,
+ where an external PWM drives the CNV pin, and Manual Mode, where CNV
+ is directly tied to the SPI chip-select.
+
+ Datasheets:
+ * https://www.analog.com/en/products/ad4692.html
+ * https://www.analog.com/en/products/ad4691.html
+ * https://www.analog.com/en/products/ad4694.html
+ * https://www.analog.com/en/products/ad4693.html
+
+$ref: /schemas/spi/spi-peripheral-props.yaml#
+
+properties:
+ compatible:
+ enum:
+ - adi,ad4691
+ - adi,ad4692
+ - adi,ad4693
+ - adi,ad4694
+
+ reg:
+ maxItems: 1
+
+ spi-max-frequency:
+ maximum: 40000000
+
+ spi-cpol: true
+ spi-cpha: true
+
+ vio-supply:
+ description: I/O voltage supply (1.71V to 1.89V or VDD).
+
+ vref-supply:
+ description: External reference voltage supply (2.4V to 5.25V).
+
+ vrefin-supply:
+ description: Internal reference buffer input supply.
+
+ reset-gpios:
+ description: GPIO connected to the RESET pin (active high).
+ maxItems: 1
+
+ clocks:
+ description: Reference clock for PWM timing in CNV Clock Mode.
+ maxItems: 1
+
+ pwms:
+ description:
+ PWM connected to the CNV pin. When present, selects CNV Clock Mode where
+ the PWM drives the conversion rate. When absent, Manual Mode is used
+ (CNV tied to SPI CS).
+ maxItems: 1
+
+ pwm-names:
+ items:
+ - const: cnv
+
+ interrupts:
+ description:
+ Interrupt line connected to the ADC GP0 pin. GP0 must be physically
+ wired to an interrupt-capable input on the SoC. The ADC asserts GP0 as
+ DATA_READY at end of conversion, used both for non-offload CNV Clock Mode
+ operation and for SPI Engine offload triggering via '#trigger-source-cells'.
+ Not used in Manual Mode, where CNV is tied to SPI CS and no DATA_READY
+ signal is generated.
+ maxItems: 1
+
+ '#trigger-source-cells':
+ description: |
+ For SPI Engine offload operation, this node acts as a trigger source.
+ Two cells are required:
+ - First cell: Trigger event type (0 = BUSY, 1 = DATA_READY)
+ - Second cell: GPIO pin number (only 0 = GP0 is supported)
+
+ Macros are available in dt-bindings/iio/adc/adi,ad4691.h:
+ AD4691_TRIGGER_EVENT_BUSY, AD4691_TRIGGER_EVENT_DATA_READY
+ AD4691_TRIGGER_PIN_GP0
+ const: 2
+
+required:
+ - compatible
+ - reg
+ - vio-supply
+ - reset-gpios
+
+allOf:
+ # vref-supply and vrefin-supply are mutually exclusive, one is required
+ - oneOf:
+ - required:
+ - vref-supply
+ - required:
+ - vrefin-supply
+
+ # CNV Clock Mode requires a reference clock.
+ - if:
+ required:
+ - pwms
+ then:
+ required:
+ - clocks
+
+ # CNV Clock Mode (pwms present) without SPI offload requires a DRDY interrupt.
+ # Offload configurations expose '#trigger-source-cells' instead.
+ - if:
+ required:
+ - pwms
+ not:
+ required:
+ - '#trigger-source-cells'
+ then:
+ required:
+ - interrupts
+
+unevaluatedProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/gpio/gpio.h>
+
+ /* Example: AD4692 in CNV Clock Mode (pwms present) with standard SPI */
+ spi {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ adc@0 {
+ compatible = "adi,ad4692";
+ reg = <0>;
+ spi-cpol;
+ spi-cpha;
+ spi-max-frequency = <40000000>;
+
+ vio-supply = <&vio_supply>;
+ vref-supply = <&vref_5v>;
+
+ reset-gpios = <&gpio 10 GPIO_ACTIVE_HIGH>;
+
+ clocks = <&ref_clk>;
+
+ pwms = <&pwm_gen 0 0>;
+ pwm-names = "cnv";
+
+ interrupts = <12 4>;
+ };
+ };
+
+ - |
+ #include <dt-bindings/gpio/gpio.h>
+
+ /* Example: AD4692 in Manual Mode (no pwms) with SPI Engine offload */
+ spi {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ adc@0 {
+ compatible = "adi,ad4692";
+ reg = <0>;
+ spi-cpol;
+ spi-cpha;
+ spi-max-frequency = <31250000>;
+
+ vio-supply = <&vio_supply>;
+ vrefin-supply = <&vrefin_supply>;
+
+ reset-gpios = <&gpio 10 GPIO_ACTIVE_HIGH>;
+ };
+ };
diff --git a/MAINTAINERS b/MAINTAINERS
index 61bf550fd37c..9994d107d88d 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1484,6 +1484,14 @@ W: https://ez.analog.com/linux-software-drivers
F: Documentation/devicetree/bindings/iio/adc/adi,ad4170-4.yaml
F: drivers/iio/adc/ad4170-4.c
+ANALOG DEVICES INC AD4691 DRIVER
+M: Radu Sabau <radu.sabau@xxxxxxxxxx>
+L: linux-iio@xxxxxxxxxxxxxxx
+S: Supported
+W: https://ez.analog.com/linux-software-drivers
+F: Documentation/devicetree/bindings/iio/adc/adi,ad4691.yaml
+F: include/dt-bindings/iio/adc/adi,ad4691.h
+
ANALOG DEVICES INC AD4695 DRIVER
M: Michael Hennerich <michael.hennerich@xxxxxxxxxx>
M: Nuno Sá <nuno.sa@xxxxxxxxxx>
diff --git a/include/dt-bindings/iio/adc/adi,ad4691.h b/include/dt-bindings/iio/adc/adi,ad4691.h
new file mode 100644
index 000000000000..294b03974f48
--- /dev/null
+++ b/include/dt-bindings/iio/adc/adi,ad4691.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */
+
+#ifndef _DT_BINDINGS_ADI_AD4691_H
+#define _DT_BINDINGS_ADI_AD4691_H
+
+/* Trigger event types */
+#define AD4691_TRIGGER_EVENT_BUSY 0
+#define AD4691_TRIGGER_EVENT_DATA_READY 1
+
+/* Trigger GPIO pin selection */
+#define AD4691_TRIGGER_PIN_GP0 0
+
+#endif /* _DT_BINDINGS_ADI_AD4691_H */
--
2.43.0