Re: [PATCH v2 2/2] iio: light: vcnl4000: add shared IRQ support

On Sat, Aug 22, 2026 at 03:25:50AM +0100, Jonathan Cameron wrote:
> On Fri, 14 Aug 2026 14:30:43 +1000
> Tsz Shan Chan <[email protected]> wrote:

> > The INT output of vcnl4010/4020 and vcnl4040/4200 is open drain active
> > low which can be shared with other devices.
> > Add IRQF_SHARED and switch the trigger type from IRQF_TRIGGER_FALLING to
> > IRQF_TRIGGER_LOW. Edge triggering can miss interrupts on a shared line.
> Fairly low risk change but I guess we'll see.
> 
> It used to be annoyingly common for interrupt controllers to support
> only edge based interrupts, but hopefully that silliness is a thing
> of the past.
> 
> So crossed fingers, I'll apply this and see if we get anyone shouting.
> I think we'll get away with it

In another thread somebody mentioned a type of the signal that HW generates.
Having OD output doesn't prevent HW to behave like it does edge interrupts,
id est generating a pulse instead of keeping the level until it gets acked.
With that being said, I would ask the datasheet citation to clarify the case.

-- 
With Best Regards,
Andy Shevchenko