Receive IRQ from a GPIO pin
 

Hi,

I'm currently developing on a DMP Vortex86DX cpu board. My next aim is to receive and handle an interrupt if there are new signals from certain GPIO Ports.

The Board is using two 8259 compatible interrupt controllers. In the BIOS I can switch the pins from
GPIO to 8051 PO mode.

My questions:
- How to assign an IRQ in my Linux device driver to a single i/o pin?
- Do I have to program (somehow) the 8259 interrupt controller in order to route an interrupt to a single pin or a bank of pins?
- Do I have to set the pins into 8051 PO mode?
- In General: Does Linux reserves all IRQs for its self on the 8259 and dispatch them to the several device drivers instances?
- How much depends this task on the used hardware. Means: Do I need a solder gun?

thanks for your help.

I received an answer from the Vortex producer DMP. The are currently selling Vortex86DX CPUs which are not equiped with IRQs to the GPIOs.
Even if this feature has been advertised for the DX SOC processor since long time, it won't be available for cpus delivered before the fourth quarter of this year.

They are advertising features which aren't implemented currently. "Hope" seems to be still a good sales argument.