Re: [RFC] gpio: expose pull-up/pull-down line flags to userspace

[Kent Gibson <warthog618@gmail.com>]

On Wed, Oct 09, 2019 at 02:57:27PM +0200, Drew Fustini wrote:
> 
> On Wed, Oct 09, 2019 at 02:55:24PM +0800, Kent Gibson wrote:
> > Safe to assume your code is in your topic/gpio-uapi-config branch?
> > I hope so, cos I've forked from that into github.com/warthog618/linux 
> > and have started working on it.
> > 
> > So far I've added pull up/down support to lineevent_create, and 
> > added default_values to the gpiohandle_config (for setting outputs).
> > Currently looking at implementing the actual set config, and sucking
> > on whether that is best done by refactoring bit out of
> > linehandle_create.
> > 
> > Will sort that into patches once it is in a fit state.
> > Feel free to poke me if I'm going off track.
> > 
> > Cheers,
> > Kent.
> 
> Great to see that work on this capability is moving foward.  I also have
> spare time so I'm eager to help however I can.
> 
> I had been working from the kernel.org torvalds/linux.git master to
> create a patch and used 'git send-email' to post a patch.  It is
> interesting that Bartosz and you have forks of linux where you created
> topic branches.  I just added warthog618/linux as a remote so I can view
> and try out your commits.
> 
Sorry that the branch is a munge of the pull up/down and set config changes.
And I have no idea how I'm going to sort this into a reasonable patch
sequence, but I'll burn that bridge when I get to it.

I'm reasonably happy with the state of the pull up/down.  That is
passing all my tests on gpio-mockup - other than the actual value being
pulled - but that is because gpio-mockup needs to be updated.
Which is next on the todo list. Along with building a Pi kernel to test
real hardware.  

I'd steer clear of the SET_CONFIG changes for the moment - those 
are totally untested.
But I guess you don't have any code to call the ioctl yet anyway...
That is slightly further down the todo list.

Cheers,
Kent.