Re: [PATCH v8 1/6] dt-bindings: pinctrl: add NXP MC33978/MC34978 MSDI

Rob Herring (Arm)
2026-03-29T10:30:15Z

On Sun, 29 Mar 2026 11:05:56 +0200, Oleksij Rempel wrote:
> Add device tree binding documentation for the NXP MC33978 and MC34978
> Multiple Switch Detection Interface (MSDI) devices.
>
> The MC33978 and MC34978 differ primarily in their operating temperature
> ranges. While not software-detectable, providing specific compatible
> strings allows the hwmon subsystem to correctly interpret thermal
> thresholds and hardware faults.
>
> These ICs monitor up to 22 mechanical switch contacts in automotive and
> industrial environments. They provide configurable wetting currents to
> break through contact oxidation and feature extensive hardware
> protection against thermal overload and voltage transients (load
> dumps/brown-outs).
>
> The device interfaces via SPI. While it provides multiple functions, its
> primary hardware purpose is pin/switch control. To accurately represent
> the hardware as a single physical integrated circuit without unnecessary
> DT overhead, all functions are flattened into a single pinctrl node:
> - pinctrl: Exposing the 22 switch inputs (SG/SP pins) as a GPIO controller
> and managing their pin configurations.
> - hwmon: Exposing critical hardware faults (OT, OV, UV) and static
> voltage/temperature thresholds.
> - mux: Controlling the 24-to-1 analog multiplexer to route pin voltages,
> internal temperature, or battery voltage to an external SoC ADC.
>
> Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
> Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
> Reviewed-by: Linus Walleij <linusw@kernel.org>
> ---
> changes v8:
> - Update IRQ_TYPE_* macros include path reference in documentation from
> interrupt-controller.h to dt-bindings/interrupt-controller/irq.h.
> - Add bias-disable, drive-open-drain, drive-open-source, and drive-strength
> to the list of supported pin configuration properties.
> changes v7:
> - no changes
> changes v6:
> - add Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
> - add Reviewed-by: Linus Walleij <linusw@kernel.org>
> changes v5:
> - Commit Message: Added justification for distinct compatible strings
> based on temperature ranges.
> - Restricted pins property to an explicit enum of valid hardware pins
> changes v4:
> - Drop the standalone mfd/nxp,mc33978.yaml schema entirely.
> - Move the unified device binding to bindings/pinctrl/nxp,mc33978.yaml,
> - Remove the dedicated child node compatible strings (nxp,mc33978-pinctrl).
> - Flatten the pinctrl/gpio properties directly into the main SPI device
> node.
> changes v3:
> - Drop regular expression pattern from pinctrl child node and define
> it as a standard property
> - Reorder required properties list in MFD binding
> - Remove stray blank line from the MFD binding devicetree example
> - Replace unevaluatedProperties with additionalProperties in the pinctrl
> binding
> changes v2:
> - Squashed MFD, pinctrl, hwmon, and mux bindings into a single patch
> - Removed the empty hwmon child node
> - Folded the mux-controller node into the parent MFD node
> - Added vbatp-supply and vddq-supply to the required properties block
> - Changed the example node name from mc33978@0 to gpio@0
> - Removed unnecessary literal block scalars (|) from descriptions
> - Documented SG, SP, and SB pin acronyms in the pinctrl description
> - Added consumer polarity guidance (GPIO_ACTIVE_LOW/HIGH) for SG/SB
> inputs, with a note on output circuit dependency
> - Updated commit message
> ---
> .../bindings/pinctrl/nxp,mc33978.yaml | 158 ++++++++++++++++++
> 1 file changed, 158 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/pinctrl/nxp,mc33978.yaml
>

My bot found errors running 'make dt_binding_check' on your patch:

yamllint warnings/errors:

dtschema/dtc warnings/errors:
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/pinctrl/nxp,mc33978.example.dtb: gpio@0 (nxp,mc33978): $nodename:0: 'gpio@0' does not match '^mux-controller(@.*|-([0-9]|[1-9][0-9]+))?$'
from schema $id: http://devicetree.org/schemas/mux/mux-controller.yaml

doc reference errors (make refcheckdocs):

See https://patchwork.kernel.org/project/devicetree/patch/20260329090601.532477-2-o.rempel@pengutronix.de

The base for the series is generally the latest rc1. A different dependency
should be noted in *this* patch.

If you already ran 'make dt_binding_check' and didn't see the above
error(s), then make sure 'yamllint' is installed and dt-schema is up to
date:

pip3 install dtschema --upgrade

Please check and re-submit after running the above command yourself. Note
that DT_SCHEMA_FILES can be set to your schema file to speed up checking
your schema. However, it must be unset to test all examples with your schema.