* Re: [PATCH v2] dt-bindings: iio: adc: add documentation for adi,ad7816
2026-10-18 10:43 [PATCH v2] dt-bindings: iio: adc: add documentation for adi,ad7816 wrmfwv
@ 2026-10-18 10:51 ` sashiko-bot
0 siblings, 0 replies; 2+ messages in thread
From: sashiko-bot @ 2026-10-18 10:51 UTC (permalink / raw)
To: wrmfwv; +Cc: devicetree, robh, conor+dt
Thank you for your contribution! Sashiko AI review found 3 potential issue(s) to consider:
- [Medium] dt-bindings: iio: adc: missing maxItems on gpios and ad7818 busy constraint
- [Medium] dt-bindings: iio: adc: missing spi-peripheral-props.yaml ref in adi,ad7816
- [Low] dt-bindings: iio: adc: wrong IRQ trigger type in adi,ad7816 example
--
commit 172592494e92c865cd70820f7a6919506c5b2b75
Author: Tenglong Guo <admin@micronull.cn>
dt-bindings: iio: adc: add documentation for adi,ad7816
This commit adds a devicetree YAML binding schema for the Analog Devices
AD7816, AD7817, and AD7818 SPI ADC family.
> diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ad7816.yaml b/Documentation/devicetree/bindings/iio/adc/adi,ad7816.yaml
> new file mode 100644
> index 0000000000000..d23ef9163e61e
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/adc/adi,ad7816.yaml
> @@ -0,0 +1,76 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/iio/adc/adi,ad7816.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Analog Devices AD7816/AD7817/AD7818 ADC
> +
> +maintainers:
> + - Tenglong Guo <admin@micronull.cn>
> +
> +description: |
> + The AD7816/AD7817/AD7818 are 10-bit ADCs with on-chip temperature sensors.
> + They use a SPI interface for communication.
> +
> +properties:
> + compatible:
> + enum:
> + - adi,ad7816
> + - adi,ad7817
> + - adi,ad7818
> +
> + reg:
> + maxItems: 1
> +
> + rdwr-gpios:
> + description: GPIO connected to the RD/WR pin.
> +
> + convert-gpios:
> + description: GPIO connected to the CONVST pin.
> +
> + busy-gpios:
> + description: GPIO connected to the BUSY pin. Required for AD7816 and AD7817.
> +
> + interrupts:
> + maxItems: 1
> + description: Optional interrupt for over-temperature indication.
> +
> +required:
> + - compatible
> + - reg
> + - rdwr-gpios
> + - convert-gpios
> +
> +allOf:
> + - if:
> + properties:
> + compatible:
> + contains:
> + enum:
> + - adi,ad7816
> + - adi,ad7817
> + then:
> + required:
> + - busy-gpios
[Severity: Medium]
Should rdwr-gpios, convert-gpios, and busy-gpios specify maxItems: 1, and
should the allOf conditional block disallow busy-gpios on adi,ad7818?
In drivers/staging/iio/adc/ad7816.c, ad7816_probe() requests a single GPIO
descriptor for each line and only requests busy on AD7816 and AD7817:
drivers/staging/iio/adc/ad7816.c:ad7816_probe() {
...
chip->rdwr_pin = devm_gpiod_get(&spi_dev->dev, "rdwr", GPIOD_OUT_HIGH);
...
chip->convert_pin = devm_gpiod_get(&spi_dev->dev, "convert",
GPIOD_OUT_HIGH);
...
if (chip->id == ID_AD7816 || chip->id == ID_AD7817) {
chip->busy_pin = devm_gpiod_get(&spi_dev->dev, "busy",
GPIOD_IN);
...
}
Without maxItems: 1 on rdwr-gpios, convert-gpios, and busy-gpios,
dt_binding_check fails meta-schema validation against meta-schemas/gpios.yaml.
Also, because the 8-pin AD7818 does not have a physical BUSY pin, adding an
else branch setting busy-gpios: false would prevent dtbs_check from accepting
busy-gpios on adi,ad7818 nodes.
> +
> +additionalProperties: false
[Severity: Medium]
Since the AD7816 family are SPI peripherals, does this binding need to
reference /schemas/spi/spi-peripheral-props.yaml# in allOf and use
unevaluatedProperties: false instead of additionalProperties: false?
Without referencing spi-peripheral-props.yaml# and switching to
unevaluatedProperties: false, device tree nodes using standard SPI properties
such as spi-max-frequency or spi-cpol will fail dtbs_check validation.
> +
> +examples:
> + - |
> + #include <dt-bindings/gpio/gpio.h>
> + #include <dt-bindings/interrupt-controller/irq.h>
> + spi {
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + adc@0 {
> + compatible = "adi,ad7816";
> + reg = <0>;
> + rdwr-gpios = <&gpio0 1 GPIO_ACTIVE_HIGH>;
> + convert-gpios = <&gpio0 2 GPIO_ACTIVE_HIGH>;
> + busy-gpios = <&gpio0 3 GPIO_ACTIVE_HIGH>;
> + interrupts-extended = <&gpio0 4 IRQ_TYPE_EDGE_FALLING>;
[Severity: Low]
Should the example use IRQ_TYPE_LEVEL_LOW instead of IRQ_TYPE_EDGE_FALLING?
The Over-Temperature Indicator (OTI) output is active-low level, and
ad7816_probe() in drivers/staging/iio/adc/ad7816.c explicitly requests a
low-level trigger:
drivers/staging/iio/adc/ad7816.c:ad7816_probe() {
...
if (spi_dev->irq) {
/* Only low trigger is supported in ad7816/7/8 */
ret = devm_request_threaded_irq(&spi_dev->dev, spi_dev->irq,
NULL,
&ad7816_event_handler,
IRQF_TRIGGER_LOW | IRQF_ONESHOT,
indio_dev->name,
indio_dev);
...
}
> + };
> + };
> +...
--
Sashiko AI review · https://sashiko.dev/#/patchset/20261018104358.38255-1-wrmfwv@163.com?part=1
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