Re: userspace gpio interrupts / input-output control

From: Matthew Grooms <mgrooms_at_shrew.net>
Date: Mon, 17 Aug 2026 20:22:00 UTC
On 8/17/26 15:06, Ruslan Zalata wrote:
> Thanks Matt. That's on FreeBSD, I suppose? Would like to have this 
> type of service on x86 mini-PCs. :)
>
> ---
> Regards,
> Ruslan
>
> On 2026-08-18 00:08, Matthew Grooms wrote:
>> On 8/16/26 12:13, Ruslan Zalata wrote:
>>> Hello Sulev-Madis,
>>>
>>> What's your target platform ?
>>>
>>> I recently discovered that GPIO interrupts are not supported in 
>>> "GPIO Bus" driver on x86 platforms because of lack of INTRNG support 
>>> (simply not implemented). I found a 6-year old diff D26407 from avg@ 
>>> to add this functionally which stuck on review because of some 
>>> unsolved issues. I renewed avg's patch so it could be applied to 
>>> -current and posted for review (D57968) again, but it did get much 
>>> traction too. So, if you are interested in getting GPIO interrupts 
>>> on x86/amd64 - no luck till gpiobus driver is "fixed". No ideas 
>>> about arm and others.
>>>
>> Just as a reference point, I use the gpio interrupt support on rpi4
>> hosts to track things like water flow for feed systems in an
>> industrial farm environment. Seems to work quite well. 

Yup. I have 10x rpi4b systems running FreeBSD 14 in production, They run 
a custom farm automation controller I wrote a while back in c++. The 
demo code that accompanied the original gpio interrupt patch was used as 
a reference for that specific feature. Not sure that code ever made it 
into the source tree.

-Matthew

PS: Maybe try not to top post on the list.