We would like to provide a template driver source code to be integrated with WinCE binary BSP release. If you are able to build and integrate the driver with the OS image successfully then you can modify the template driver for your requirement or add your existing driver similar structure and then continue your development. Please follow the below instructions to integrate the template driver.
For more information: please refer https://docs.microsoft.com/en-us/previous-versions/windows/embedded/aa912804%28v%3dwinembedded.60%29 documentation