It can be convenient for device users to check what it supports, without
having multiple functions to check each single feature.
So expose this and add tests.
Allows drivers to define more fine grained features for devices, not
strictly depending on assumptions we can make depending on the
implemented vfuncs.
We keep this per class but could be in theory moved to each instance.
In any case, added an utility function to initialize it in the way we
can ensure that we've a consistent way for setting them across all the
devices.
Some OEM will integrate fingerprint device with powerButton. It's
possible that a user may press the power button during fingerprint
enroll or identify. This would lead to unintended PC shutdown or
hibernation. We add pwr_btn_shield cmd and related process to shield
the power button function when the fingerprint functionality (enroll and
identify) is used and restore power button function afterwards.
there is no specific API for report finger status,
finger needed status is set when captrue sample cmd send, once cmd receive correct,
finger is pressing on sensor.
Found by coverity. While quite bad in theory, proper safeguards are in
place, so it will only result in a g_return_val_if_fail to be hit rather
than causing more severe side effects.
