On Fri, Apr 16, 2010 at 06:59:19AM +0200, ext Andrew Tverdohlebov wrote:
Dear linux-omap community,
I am writing a simple driver for BeagleBoard
and trying to get an understanding of how interrupts work.
Could you please answer a small question. What is a difference between irq
and virtual_irq_start in structure gpio_bank in file
arch/arm/plat-omap/gpio.c
As far as I understood irq corresponds to real hardware interrupts while
virtual_irq_start is completely obscure for me.
I didn't find a clue in the documentation.
it's where the gpio irqs could be placed (numbering-wise) after the irq
controller. I mean, if the irq controller has 192 irqs, gpio irqs have
to be numbered 193, 194, 195, etc... so virtual_irq_base is that initial
number.
hope I made myself clear enough :-p
if you take a look at the gpio_bank arrays on that same file and look at
the fourth initialization, you can get a clue. Take a look at the
IH_GPIO_BASE define, for example.
--
balbi
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