Re: [PATCH v5 1/7] dt-bindings: pinctrl: add NXP MC33978/MC34978 MSDI

[Linus Walleij]

On Mon, Mar 16, 2026 at 3:05 PM Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx> 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@xxxxxxxxxxxxxx>

Reviewed-by: Linus Walleij <linusw@xxxxxxxxxx>

Yours,
Linus Walleij