Device Tree • Re: CM5 overlay pull up config not correct, or ignored?

Is there something wrong with the overlay config below, or is something else causing this?

The former, and possibly two things, depending on what's in the rest of the overlay.

Thing 1: When you declare groups of GPIOs with their alternate functions and pulls, they are just possibilities. Not until a device node refers to them in a "pinctrl-" property are they actually used. Device nodes can indicate that a group of GPIOs should be claimed configured in particular ways before their probe() function is called. If the probe is unsuccessful, the GPIOs are released. In order for GPIO26 to be given a pull-up, the gt928@5d fragment of the overlay needs the following additions:Thing 2 (probably not a thing in your case): Neither of those fragments as written will do anything, because they are marked as "dormant" (disabled). They are dependent on a parameter/override enabling them. I'm fairly sure this is the case in your overlay, as it looks like the standard "crystalfontz-cfa050_pi_m" overlay that we ship with our kernels, which has the parameter to enable the fragments ("captouch"), but lacks the pinctrl- reference.

So congratulations, you've found a bug in a standard overlay. I wonder how many similar instances there are? I'll have to extend the automated checkers to catch this error.

Statistics: Posted by PhilE — Thu Nov 13, 2025 8:58 am

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