adding external interrupt support for MPC8313e bsp

Hi,
I have mpc8313e local bus connected to a external UART. and the interrupt is connected to EXT_INT2. I am able to communicate to UART if I disable IRQ i.e IRQ = 0 in port structure.

I am not able to understand how to tell kernel to use external IRQ -2. Should I put the external interrupts in device tree and if so how?

or can I use the interrupt directly in the driver and in that case do I need to map the interrupt.

Any help or pointer is highly appreciated.

Thanks in advance.

Suvidh

Yes, you should put them in the device tree in the interrupts property of the node corresponding to the device that is using the interrupt. The first cell should be 18 (decimal) for IRQ2 (see the IPIC section of the user manual for other external IRQs). The second cell is defined the same as the PQ1/CPM2 PIC described in Documentation/booting-without-of.txt (2 for falling edge, 8 for active low).

Yes, if you don't put it in the device tree you need to call irq_create_mapping(). Using the device tree is recommended.

-Scott