The input driver consists of two main components:
- a group of input modules
- a library used in manipulating these modules.
At run time, modules are linked together to form a data path for gathering data from an input device, processing the data, and then outputting the data to the system.
There are three types of modules:
- device modules
- protocol modules
- filter modules.
The modules are typically organized as follows:
Figure 1. The input chain.When modules are linked together, they form an "event bus line." Data passes from an input device up the event bus line and out to the system. Conversely, configuration control flows the other way (i.e. down the line to the device).