Re: [PATCH v8 5/6] hwmon: add NXP MC33978/MC34978 driver

[Guenter Roeck]

On 3/29/26 02:06, Oleksij Rempel wrote:
> Add hardware monitoring support for the NXP MC33978/MC34978 Multiple
> Switch Detection Interface (MSDI).
>
> The hardware utilizes a clear-on-read FAULT register, but physical
> faults remain asserted as long as the underlying condition exists. This
> asserts a global FAULT_STAT bit on the SPI bus. To handle this without
> trapping the CPU in an interrupt storm, this driver implements the
> following architecture:
> - Requests a rising-edge nested IRQ (IRQF_TRIGGER_RISING) from the MFD
>    core to catch the initial 0 -> 1 transition of the global fault state.
> - Caches hwmon-specific alarm bits and calculates state edges (XOR) to
>    isolate alarm transitions from system integrity faults.
> - Implements a 1Hz delayed workqueue that polls the hardware as long as
>    any alarm is active. This compensates for the edge-triggered IRQ by
>    discovering secondary faults that occur without a rising edge, and
>    detecting when the hardware clears.
>
> Signed-off-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>

Acked-by: Guenter Roeck <linux@xxxxxxxxxxxx>