Hi All,

I'm looking for some guidance exposing hardware interrupts to user space.

Having said that, my problem may be that I am taking the wrong approach. So instead of looking for an answer to my current problem, I'll explain what I am trying to achieve.

The scenario:

Hardware: Telit GE863-PRO3 (contains a at91sam9260)
OS: Linux 2.6.24-rc5-rt1 #1 PREEMPT RT


We want the device to be in low power mode while there is no activity (the devices will be always on and we need to conserve power).

We have some devices that communicate via the SPI bus, and since we want to be in low power mode, we want the devices to notify us that data is ready to be read by triggering a hardware interrupt rather than polling.

I am unable to find any method of acting on the hardware interrupts in user space other than writing a kernel driver. I would expect that a more simple approach exits (?).

Is this approach sensible? If so, what is the best way forward?

I would expect that anyone using the SPI bus would need to do something similar, therefor I expect that a simple mechanism exists that I am failing to see.

Some additional information:

The vendor provided environment provides modules that provide char devices to access the SPI bus and the gpio devices:

/dev/spidev1.1

and

/dev/at91sam9260_gpio0
... through
/dev/at91sam9260_gpio95

It seems that some of the GPIO lines can be configured to choose the chipselect for the SPI bus, I haven't tried or verified this yet.

Any help will be greatly appreciated.

Cheers,
Karl