Re: MPC85xx - accessing external interrupt
From: tiejun.chen <hidden>
Date: 2010-08-30 11:16:11
deebul nair wrote:
Hi all
I am trying to use the external interrupts on the Powerpc architecture
MPC8542 .
My problem is that my driver is trying to request the external
interrupt IRQ1, and I dont know what number use in INTR_NUM:
request_irq(INTR_NUM, , , , )
As per the MPC85xx documentation
Documentation/powerpc/dts-bindings/fsl/mpic.txt
about the implementation of interrupts virtual numbers
the external interrupt virtual irq number for IRQ1 should be 1
but when i try to give INTR_NUM ins request_irq as 1 it gives error .
When i use irq_create_mapping() it gives me output as 16.. and it registers
.. but the problem is it is not fixed
neither it gives interrupts .
when i remove and add it registers to some other addresses
i even tried irq_of_parse_map()
for_each_node_by_type(np,"interrupt-controller"){
if(of_device_is_compatible(np,"chrp,open-pic")){
found=np;
break;
}
}
virq = irq_of_parse_and_map(found, irq);
this always returns 0
whatever may be the irq value..
as a result the driver gives error for irq 0
Anyway the following path should be the correct path:
request_irq(virq)
|
+ virq = irq_of_parse_and_map(hw_irq)
|
+ We get this from the dts file.
So you should define the appropriate node for your device. Then convert your
hw_irq to vir_irq via irq_of_parse_and_map() to pass that to reuest_irq() on
your device driver. Sometime this process is wrapped by some functions so I
recommend you refer to the files on the directory, arch/powerpc/sysdev/.
But I think the root cause to your problem is that you cannot pass the proper
arguments to irq_of_parse_and_map().
------
unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
You should do this like the following:
------
struct device_node *np;
unsigned int virq;
np = of_find_compatible_node(NULL, NULL, "<the compatible property of your
device node on dts>");
if (np) {
irq_of_parse_and_map(np, 0);
}
request_irq(virq,......);
Here I assume you have only one irq property so set 'index' as '0' on the
function, irq_of_parse_and_map().
Cheers
Tiejun
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