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By having a pseudo device we can interact with different SPI >> devices. > >> Yes by default nothing is connected and so there is nothing to talk to. >> However, this does enable us to do SPI loopback testing for example. > >> So I am wondering if it would be acceptable to having some generic dummy >> device-tree compatible string for this? I guess it does not need to be Tegra >> specific. > > I understand what he's trying to accomplish, it's the same thing as > what everyone who wants to put a raw spidev compatible in their DT is > trying to do. The way to do this would be something like a DT overlay > that describes whatever is actually connected, or just customise the DT > locally. We could certainly use an overlay, but how do we handle the kernel side? My understanding is that per patch 3/3 we need to reference a compatible string the kernel is aware of. I guess we could use an existing one, but feels like a massive hack. It would be nice if there is something generic we can use for this like 'linux,spidev'. I see that ACPI has something and it does print a warning that this should not be used in production systems. Jon -- nvpublic