I'm working on a port of the Linux kernel to an unsupported ARM SoC platform. Unfortunately, on this SoC, different peripherals will sometimes share registers or commingle registers within the same region of memory. This is giving me grief with the Device Tree specification which doesn't seem to support the notion of different devices sharing the same set of registers or registers commingled in the same address space. Various documents I've read on the device tree don't suggest the proper way to handle this.
My simple approach to specify the same register region within multiple drivers throws "can't request region for resource" for the second device that attempts to map the same register region as another driver. From my understanding, this results from the kernel enforcing device tree rules regarding register regions.
What is the preferred general solution for solving this dilemma? Should there be a higher level driver that marshals access to the shared register region? Are there examples in the existing Linux kernel that address this specific issue (I couldn't find any, but I may not be sure what to look for)?
