Re: [PATCH v1 2/8] dt-bindings: iio: dac: maxim,ds4424: add maxim,rfs-ohms property
From: Conor Dooley <conor@kernel.org>
Date: 2026-01-19 18:27:57
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linux-iio, lkml
On Mon, Jan 19, 2026 at 07:24:18PM +0100, Oleksij Rempel wrote:
Introduce the 'maxim,rfs-ohms' property. The full-scale output current of these DACs is determined by external resistors (Rfs) connected to the FS pins. The driver requires the physical resistance values to calculate the correct current scale (Amps per step) for the IIO subsystem. Keep it optional to avoid forcing updates of existing DTs; without it the driver cannot derive a correct IIO scale.
I don't really follow the logic here, if the driver doesn't work properly without it, shouldn't it be a required property even if that means existing devicetrees get new warnings? Warnings are preferable to the drivers malfunctioning on those devices, after all!
quoted hunk ↗ jump to hunk
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de> --- .../devicetree/bindings/iio/dac/maxim,ds4424.yaml | 11 +++++++++++ 1 file changed, 11 insertions(+)diff --git a/Documentation/devicetree/bindings/iio/dac/maxim,ds4424.yaml b/Documentation/devicetree/bindings/iio/dac/maxim,ds4424.yaml index efe63e6cb55d..b7af8464a4fc 100644 --- a/Documentation/devicetree/bindings/iio/dac/maxim,ds4424.yaml +++ b/Documentation/devicetree/bindings/iio/dac/maxim,ds4424.yaml@@ -27,6 +27,17 @@ 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). + minItems: 2 + maxItems: 4 + $ref: /schemas/types.yaml#/definitions/uint32-array + required: - compatible - reg-- 2.47.3
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