Subsystem communication

Hi, currently i want to implement a driver for the power subsystem of the Freescale i.MX28 (ARM9). On the one hand the driver should trigger the registering of the underlying components like regulators and on the other hand it should take care of the incoming interrupts and provide the results to the underlying components. I think the first task can easily done by of_platform_populate(). But for the second task i'm not sure how to achieve a clean, mostly readonly access from the regulator drivers to the power subsystem driver. I have read about exporting symbols and RCU, but i'm not sure what's preferred in that situation. Best regards Stefan