Felix,
On Wednesday 15 October 2008, Felix Radensky wrote:
> I'm running Linux 2.6.26 on custom board based on AMCC 460EX.
> I'm trying to catch interrupt generated by CPLD, but without any luck.
>
> The interrupt is connected to GPIO 45. U-Boot (1.3.4) configures this
> pin as external interrupt 12 (interrupt 20 in UIC 3). I've added the
> following
> entry to board device tree (in opb section)
>
> [EMAIL PROTECTED],0 {
> device_type = "cpld";
> interrupts = <20 1>;
Is this interrupt active on rising edge? This is what you have configured
here. When you need level, active low, then you need to write:
interrupts = <20 8>;
And be careful which dts version you are using. Is this 20 decimal or hex?
> interrupt-parent = <&UIC3>;
> };
>
> In my driver I do the following:
>
> /* Find CPLD node in device tree */
> np = of_find_node_by_type(NULL, "cpld");
> if (!np) {
> printk(KERN_INFO "No CPLD found in device tree\n");
> return -1;
> }
>
> /* Get and map irq number from device tree */
> cpld_irq = irq_of_parse_and_map(np, 0);
> if (cpld_irq == NO_IRQ) {
> printk(KERN_ERR "irq_of_parse_and_map failed\n");
> of_node_put(np);
> return -ENODEV;
> }
>
> /* Register CPLD interrupt handler */
> rc = request_irq(cpld_irq, cpld_interrupt,
> IRQF_TRIGGER_LOW, "CPLD", NULL);
>
> And I see this interrupt in /proc/interrups after loading
> the driver. However interrupt handler is never invoked,
> although hardware guys see that GPIO line goes down
> when interrupt is generated.
>
> What am I doing wrong ?
Another idea is that you didn't configure the pin multiplexing correctly. Most
external IRQ's are shared with other functions and/or GPIO's. You need to
configure the multiplexing correctly for external IRQ functionality. This is
usually done in U-Boot with the CFG_4xx_GPIO_TABLE.
I suggest you check here first.
Best regards,
Stefan
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