[MPC5200] using GPT's for interrupts
albrecht.dress at arcor.de
Fri Jun 15 22:58:10 EST 2012
I currently try to use a MPC5200B GPT as interrupt source, which according to the comment at the start of arch/powerpc/platforms/52xx/mpc52xx_gpt.c is possible if the "interrupt-controller" and "#interrupt-cells = < 1 >" properties are added to the device tree node.
Apparently, /some/ work is done during startup, as I can see in the boot log:
[ 0.438623] gpiochip_find_base: found new base at 251
[ 0.444202] mpc52xx-gpt f0000650.timer: mpc52xx_gpt_irq_setup() complete. virq=78
In my driver, I identify the GPT node, call irq_of_parse_and_map() to get the irq number (which succeeds, with the same number as above), but unfortunately request_irq() or devm_request_irq() for this irq fail with error -22. I tracked the failed call down to request_threaded_irq() which ejects because irq_settings_can_request(desc) returns false.
Before digging deeper into the code, maybe someone can tell me what I missed... I'm using kernel 3.2.16.
Thanks in advance,
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