Re: [PATCH v2 1/2] dt-bindings: hwmon: pmbus: Add Infineon tda38740 and tda38725

From: Conor Dooley

Date: Mon Sep 07 2026 - 13:06:56 EST


On Mon, Sep 07, 2026 at 02:52:29PM +0800, Colin Huang wrote:
> From: Colin Huang <u8813345@xxxxxxxxx>
>
> Add devicetree bindings for the Infineon TDA38740 and TDA38725
> single-voltage synchronous buck regulators with PMBus interface.
>
> Signed-off-by: Colin Huang <u8813345@xxxxxxxxx>
> ---
> .../bindings/hwmon/pmbus/infineon,tda38740.yaml | 82 ++++++++++++++++++++++
> 1 file changed, 82 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/hwmon/pmbus/infineon,tda38740.yaml b/Documentation/devicetree/bindings/hwmon/pmbus/infineon,tda38740.yaml
> new file mode 100644
> index 000000000000..c9bf19902d3c
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/hwmon/pmbus/infineon,tda38740.yaml
> @@ -0,0 +1,82 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +
> +$id: http://devicetree.org/schemas/hwmon/pmbus/infineon,tda38740.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Infineon TDA38740 and TDA38725 PMBus Synchronous Buck Regulator
> +
> +maintainers:
> + - Colin Huang <u8813345@xxxxxxxxx>
> +
> +description: |
> + The Infineon TDA38740/TDA38725 is a 40A/25A single-voltage synchronous
> + buck regulator with a PMBus interface designed for industrial use.
> +
> + Datasheet:
> + https://www.infineon.com/row/public/documents/24/49/infineon-tda38740-tda38725-datasheet-en.pdf
> +
> +properties:
> + compatible:
> + enum:
> + - infineon,tda38725
> + - infineon,tda38740

If the programming model for these devices doesn't differ, one should
fall back to the other.

> +
> + reg:
> + maxItems: 1
> +
> + infineon,vout-scale-micro:
> + description: |
> + Scaling factor applied to READ_VOUT telemetry.
> +
> + TDA38740/25 pin strap parts are available in two flavors of
> + VOUT_SCALE_LOOP: 1:1 and 1:2.
> +
> + For the 1:1 VOUT_SCALE_LOOP version, output voltage sense pins are
> + directly connected to the output, and no resistor divider is used.
> +
> + For the 1:2 version, a resistor divider is typically used (for example,
> + 499 ohms for both top and bottom resistors).
> +
> + In some designs, users intentionally modify the feedback divider ratio
> + to obtain an output voltage different from the internally configured
> + VBOOT or VOUT value.
> +
> + In such cases, the device telemetry (READ_VOUT) continues to report
> + the internally programmed voltage and does not reflect the actual
> + externally adjusted output voltage.
> +
> + This property provides a multiplier to scale the reported telemetry
> + value so that the monitoring system reflects the actual output voltage.
> +
> + The value shall be expressed in micro units where 1,000,000 represents
> + a scaling factor of 1.0.
> +
> + Example:
> + If actual Vout = 0.75V and READ_VOUT reports 0.7V:
> + scaling factor = 0.75 / 0.7 = 1.071
> + value = 1071000
> + $ref: /schemas/types.yaml#/definitions/uint32
> + minimum: 100000
> + maximum: 2000000

This is not a required property, so you need a default.
pw-bot: changes-requested

Thanks,
Conor.

> +
> +required:
> + - compatible
> + - reg
> +
> +additionalProperties: false
> +
> +examples:
> + - |
> + i2c {
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + sensor@40 {
> + compatible = "infineon,tda38740";
> + reg = <0x40>;
> + infineon,vout-scale-micro = <1071000>;
> + };
> + };
> +
>
> --
> 2.34.1
>

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