sofle: add underglow support with &pinctrl update

[SethMilliken]

Multiple folks on the ZMK Discord server have recently run into difficulties trying to get RGB underglow working on their Sofle, as a result of mainline Sofle not having &led_strip defined. This nice_nano_v2.overlay—similar to overlays for other boards (differing only in default chain-length)—should be sufficient to remove this hurdle for others.

[caksoylar]

It might make sense to add the commented out underglow options to https://github.com/zmkfirmware/zmk/blob/main/app/boards/shields/sofle/sofle.conf, similar to other shields like https://github.com/zmkfirmware/zmk/blob/main/app/boards/shields/corne/corne.conf.

[SethMilliken]

It might make sense to add the commented out underglow options to https://github.com/zmkfirmware/zmk/blob/main/app/boards/shields/sofle/sofle.conf, similar to other shields

Good call. Added.

[caksoylar]

Thanks! Can you also add a duplicate nice_nano.overlay? While we are not very consistent on adding an overlay for every compatible board, we seem to be consistent in supporting both versions if we support one, at the moment.

[SethMilliken]

Thanks! Can you also add a duplicate nice_nano.overlay? While we are not very consistent on adding an overlay for every compatible board, we seem to be consistent in supporting both versions if we support one, at the moment.

I had wondered about that, myself. Done.

[caksoylar]

Thanks, LGTM.

[SethMilliken]

Just realized while digging through PRs for another Sofle-related issue that this work had already been done more than a year ago: #1188

Any idea how we can get that merged?

[SethMilliken]

Another person on Discord ran into the missing underglow support for the Sofle.

In this PR I have now rebased #1188 and applied the &pinctrl updates to the overlay files.

[SMQuazi]

built using this fork and it worked as expected: https://github.com/SMQuazi/zmk-config

Both underglow and per key LEDs worked.

[SethMilliken]

Sofle users continue to run into issues that would not have occurred if these changes had been merged. These changes are now over a year and a half old and have been successfully used by many people. Can we please get this merged?

[SethMilliken]

On behalf of illuminated Sofle users yet to come, thank you @petejohanson! And thank you @infused-kim for doing all of the heavy lifting on this in #1188!