The basic model is that image drivers declare a fp_img_driver structure
rather than a fp_driver struct. fp_img_driver will contain primitive imaging
operations such as 'scan finger and return image'. The imgdev layer will
generically implement the primitive fp_driver operations, and the imgdev
layer will fix up the enroll/verify/etc pointers at driver registration
time.
Removed const from all fp_driver declarations, as these are now modified
dynamically in the case of imaging drivers.
Convert enrollment function to return a signed integer, which is negative
on error or corresponds into fp_enroll_result otherwise.
Now we can treat a 'FAIL' condition differently from an actual error: fail
means that enrollment didn't complete because the data was nonsense or
whatever (e.g. scanned a different finger for each stage?).
Updated upekts accordingly.
This completes an enrollment implementation for the upekts driver.
It's based on code from libthinkfinger, but as there seemed to be many
unknown details there, I spent some time analysing the bus messages in
more detail and have effectively rewritten almost all of the borrowed code.
Note that libthinkfinger is GPL licensed, so that reflects on this code too.
At release time I will ask them if they are OK for me to relicense it.