[PATCH v2 2/8] dt-bindings: iio: dac: maxim,ds4424: add maxim,rfs-ohms property
From: Oleksij Rempel <o.rempel@pengutronix.de>
Date: 2026-01-27 06:09:43
Also in:
linux-iio, lkml
Subsystem:
iio subsystem and drivers, open firmware and flattened device tree bindings, the rest · Maintainers:
Jonathan Cameron, Rob Herring, Krzysztof Kozlowski, Conor Dooley, Linus Torvalds
The Maxim DS4422/DS4424 and DS4402/DS4404 current DACs determine their full-scale output current via external resistors (Rfs) connected to the FSx pins. Without knowing these values, the full-scale range of the hardware is undefined. Add the 'maxim,rfs-ohms' property to describe these physical components. This property is required to provide a complete description of the hardware configuration. Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de> --- changes v2: - make maxim,rfs-ohms a required property as the hardware range is undefined without external resistors. - add allOf constraints to enforce 2 vs 4 items in maxim,rfs-ohms based on compatible string. - drop explicit $ref for maxim,rfs-ohms to fix dt_binding_check warning. - update example in binding to include the new required property. --- .../bindings/iio/dac/maxim,ds4424.yaml | 36 +++++++++++++++++++ 1 file changed, 36 insertions(+)
diff --git a/Documentation/devicetree/bindings/iio/dac/maxim,ds4424.yaml b/Documentation/devicetree/bindings/iio/dac/maxim,ds4424.yaml
index efe63e6cb55d..400afd8771aa 100644
--- a/Documentation/devicetree/bindings/iio/dac/maxim,ds4424.yaml
+++ b/Documentation/devicetree/bindings/iio/dac/maxim,ds4424.yaml@@ -27,9 +27,44 @@ properties: vcc-supply: true + maxim,rfs-ohms: + description: | + Array of resistance values in Ohms for the external Rfs resistors + connected to the FS pins. + - For DS44x2 (2 channels): 2 values required. + - For DS44x4 (4 channels): 4 values required. + Typical values range from 40000 (40 kOhm) to 160000 (160 kOhm). + required: - compatible - reg + - maxim,rfs-ohms + +allOf: + - if: + properties: + compatible: + contains: + enum: + - maxim,ds4402 + - maxim,ds4422 + then: + properties: + maxim,rfs-ohms: + minItems: 2 + maxItems: 2 + - if: + properties: + compatible: + contains: + enum: + - maxim,ds4404 + - maxim,ds4424 + then: + properties: + maxim,rfs-ohms: + minItems: 4 + maxItems: 4 additionalProperties: false
@@ -43,6 +78,7 @@ examples: compatible = "maxim,ds4424"; reg = <0x10>; /* When A0, A1 pins are ground */ vcc-supply = <&vcc_3v3>; + maxim,rfs-ohms = <5100>, <5100>, <5100>, <5100>; }; }; ...
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2.47.3