Hi, I'm using libgpiod to allow gpio functionality to be used from userspace. Because of board design, some gpio's should only be used as input. Driving such gpio's as output might cause undefined behavior or damage the board. The proper way to configure such a limitation would be using the kernel devicetree definition of a gpio. To my knowledge, the kernel dts currently has no way of preventing this. Also, functionality is needed to be able to define the initial direction/state of gpio's, which should be allowed to be changed by userspace at a later point in time. To my knowledge, the kernel dts currently has no proper way of supporting this. There is the "gpio-hog" to define the initial state of a gpio at boot time, but then cannot be used by libgpiod in userspace, as the pin is reported to be "in use". I'm not sure if these two requirements have been discussed in the past, but in my opinion, in order to properly support gpio's in userspace from a boards perspective, this functionality is needed. I'd like an opinion from the maintainers about these requirements and in case there is no objection we could start a discussion about the proper way to implement this. Thanks, Henri
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