config-pin lacking

[gno...@globalcooling.com]

config-pin does not have the functionality necessary, especially for the PRU pins. We lack the ability to allow pull ups and pull downs with the pin functions. In general, I believe it would make more sense to allow or-ing of speed | input | up/down | enable pull | mode.

Should config-pin be changed to allow more flexibility?

[Robert Nelson]

On Thu, Aug 29, 2019 at 2:23 PM <gno...@globalcooling.com> wrote:
>
> config-pin does not have the functionality necessary, especially for the PRU pins. We lack the ability to allow pull ups and pull downs with the pin functions. In general, I believe it would make more sense to allow or-ing of speed | input | up/down | enable pull | mode.
>
> Should config-pin be changed to allow more flexibility?

config-pin is just a helper that reads these points from sysfs:

https://github.com/beagleboard/BeagleBoard-DeviceTrees/blob/v4.19.x-ti/src/arm/am335x-bone-common-univ.dtsi#L268-L271


For the PRU's would it actually be useful? For pretty much for-ever,
we've had the pru output set as:

PIN_OUTPUT_PULLDOWN | INPUT_EN | MUX_MODE5

and pru input as:

PIN_INPUT | MUX_MODE6

Mark/Jason, would this make sense to extend it.. ?

Regards,

--
Robert Nelson
https://rcn-ee.com/

[TJF]

For PRU pinmuxing use libpruio. It doesn't use pre-configured settings, but generates the setting on-time. This means:

1. Much faster boot time.
2. Lower memory foot print.
3. No restrictions in pinmux setting.
4. Single source pinmuxing (all done in your code)
   

Regards