Re: BeagleBone Black and GPIO issues

[Brook Milligan <brook%nmsu.edu@localhost>]

> On Oct 17, 2024, at 3:29 PM, Lloyd Parkes <lloyd%must-have-coffee.gen.nz@localhost> wrote:
> 
> Can I have some use cases please so that I can see how well they fit
> with what we can already do. Nicola, I see that you have clearly
> described what you are trying to do in the PR. Do you need to disable
> the pull-down at any point in time, or does your application need the
> pull-down enabled permanently?

It seems to me that the obvious use case is to support all the flags that are described in the gpioctl(8) man page to the degree that the gpio+control registers support it.  I’m not exactly sure without rechecking the TRM what that includes, but the maximum flexibility seems best while we are at this.

> My use case is to attach the gpioow/onewire devices to a GPIO line so
> that I can read temperatures from a Dallas DS18B20. I want to use
> parasitic power for the DS18B20 and so the owtemp driver needs to be
> able to enable and disable pullups on the fly while communicating with
> the sensor.

Cool idea.  I think that would be included within the scope of what I mentioned above.  We should be sure that manipulating dynamically any of the flags on a pin (e.g., pu/pd/etc.) only requires the pin to be configured, just as for manipulating the on/off state.

Cheers,
Brook