Possible to software trigger an interrupt?

[Jonathan Cameron <jic23@cam.ac.uk>]

Hi,

Having produced a proof of concept for using gpio chips
to handle the triggers in IIO I am looking at converting
over our sysfs trigger.  This trigger is used to initialize
capture on devices in a similar way to dataready interrupts.
The key point is we want to handle this in the same way within
drivers as the hardware event triggers. 

It is a very useful tool.  So the upshot is, what is the best
way to handle causing an interrupt to occur from userspace?

Any pointers on how to do this would be most welcome.

Thanks,

Jonathan