See <linux/platform_device.h> for the driver model interface to the platform bus: platform_device, and platform_driver. This pseudo-bus is used to connect devices on busses with minimal infrastructure,like those used to integrate peripherals on many system-on-chip processors, or some "legacy" PC interconnects; as opposed to large formally specified ones like PCI or USB.

Platform devices are devices that typically appear as autonomous entities in the system. This includes legacy port-based devices and host bridges to peripheral buses, and most controllers integrated into system-on-chip p...