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.
We always assumed a device can verify, but nothing prevents from having
a device that only can identify or capture.
So, given that we've more fine grained checks, let's stop the task if
this is the case.
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.
We were crashing as trying to still call the identify vfunc, so check if
identification is supported and if not return a relative error.
Added test as well
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.
We may want to be able to talk with the device while it's closed to
queue commands to be performed once it opens (could be even a script),
so to do this we need to close the device first, send those commands and
eventually process them.
We used a trick to send an invalid command before that was ignored by
release, but having the device available is just easier to handle.
So, when keep alive is enabled we don't stop the listener when closing
but only on actual device disposition.
The idea of the test was just checking what happens when we're opening a
device multiple times while a first request is still going.
However, it actually ends up also checking the previous commit change
because without it we'd stop the close iteration before the device is
actually closed and stop the open iteration before the device is
actually opened, leading to an infinite loop.
When opening the device we can process commands that we left for that
after the previous close, to do that we only have to inject an invalid
command that will be processed (and ignored) while closing, so that at
next device opening we will be able to proceed with the previously
sent commands.
Add tests to finally check this case!
Each command should be separated by SLEEP to be considered as something
we want to perform during the current operation, otherwise will be used
by next operation consuming it.
In case we sent a sleep event to the device we may want to wait it to
emit the finger needed state before the timeout is completed.
So add a function to manage this for all the scan cases
