Re: [PATCH v4 8/9] dt-bindings: iio: temperature: Add ADT7604 support to adi,ltc2983

[Conor Dooley <conor@kernel.org>]

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On Mon, May 25, 2026 at 07:39:35PM +0300, Liviu Stan wrote:
> The ADT7604 shares the same die as the LTC2984. It repurposes the
> custom RTD sensor type (18) as a copper trace resistance sensor
> and the custom thermistor type (27) as a leak detector, and
> removes thermocouple, diode and direct ADC sensor types.
> 
> Add adi,adt7604 to the compatible list and introduce two new
> sensor node types specific to this device:
> 
> - copper-trace@: maps to the custom RTD sensor type (18). Two
> variants: sub-ohm (< 1 ohm, adi,copper-trace-sub-ohm boolean,
> no custom table and excitation current) and standard (> 1 ohm,
> required adi,custom-copper-trace table, optional excitation current
> defaulting to the datasheet recommended value). Primary output
> is resistance in ohms. For > 1 ohm copper traces with a custom table,
> the chip also outputs temperature in millidegrees Celsius.
> 
> - leak-detector@: maps to the custom thermistor sensor type (27).
> Takes a required adi,custom-leak-detector lookup table encoding
> resistance (uOhm) against coverage data (%). Two outputs:
> resistance in ohms and coverage in percent.
> 
> Separate node types are used rather than extending the existing
> rtd@ and thermistor@ nodes because adi,custom-rtd is required
> for sensor type 18, and several properties (adi,number-of-wires,
> adi,rtd-curve, adi,rsense-share, adi,single-ended,
> adi,current-rotate) have no meaning for the new sensor types, since
> the configuration is hardcoded, and would need to be explicitly
> forbidden or ignored in the driver.
> 
> allOf conditions are added to restrict thermocouple, diode, direct
> ADC and active temperature nodes to non-ADT7604 devices, and to
> restrict copper-trace and leak-detector nodes to the ADT7604
> (some parts only).
> 
> Signed-off-by: Liviu Stan <liviu.stan@analog.com>

If this approach is acceptable to Jonathan, it is acceptable to me.
Acked-by: Conor Dooley <conor.dooley@microchip.com>
pw-bot: not-applicable

> +            leak-detector@14 {
> +                reg = <14>;
> +                adi,sensor-type = <33>;
> +                adi,rsense-handle = <&r_sense>;
> +                adi,excitation-current-nanoamp = <10000>;
> +                adi,custom-leak-detector =
> +                    /bits/ 64 <          0 100>,
> +                    /bits/ 64 <  202020000  99>,
> +                    /bits/ 64 <  285710000  70>,
> +                    /bits/ 64 <  333330000  60>,
> +                    /bits/ 64 <  400000000  50>,
> +                    /bits/ 64 <  500000000  40>,
> +                    /bits/ 64 <  666670000  30>,
> +                    /bits/ 64 < 1000000000  20>,
> +                    /bits/ 64 < 2000000000  10>,
> +                    /bits/ 64 <1000000000000 0>;

My OCD hates that you have gone to some effort with alignment here, only
for this last line's first cell to scupper it completely.

> +            };

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