While having grep in a udev rule is ugly, I assume that would only trigger if the other conditions are met (something attached to that GPIO pin that we think we might want to play with), right? If so, I think it would be safer to do the device-tree model check than to just let the rule run free.
While having grep in a udev rule is ugly, I assume that would only trigger if the other conditions are met (something attached to that GPIO pin that we think we might want to play with), right? If so, I think it would be safer to do the device-tree model check than to just let the rule run free.