Re: [libgpiod] gpiod_line_get_value_bulk may be broken?

[andy pugh <bodgesoc@xxxxxxxxx>]

On Thu, 27 Jul 2023 at 22:55, Kent Gibson <warthog618@xxxxxxxxx> wrote:

> On a Pi is it significantly faster to go direct to hardware using
> /dev/gpiomem, rather than going via the kernel as libgpiod does.
> I do my best to avoid using gpiomem these days, but if you really need to
> minimize CPU cycles or latency then that is another option.

The existing driver uses gpiomem, but the interface used seems to not
be set up in Debian Bookworm.
It might be available in _Raspbian_ but that current Raspbian version
is based on Bullseye (or Buster)

https://github.com/LinuxCNC/linuxcnc/issues/2371

Is where the suggestion was made to try gpiod, initially because of a
problem with the way we were detecting Pi versions, but then because
gpiomem wasn't there.

(It can probably be configured, but we have a user base largely made
of machinists, not Linux enthusiasts)

-- 
atp
"A motorcycle is a bicycle with a pandemonium attachment and is
designed for the especial use of mechanical geniuses, daredevils and
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