Re: Regarding hw irq to Linux irq mapping on ARM

[Grant Likely <grant.likely-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org>]

"Shaju Abraham" <shajuabraham-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:

>On Wed, Sep 22, 2010 at 3:32 AM, Benjamin Herrenschmidt
><benh-XVmvHMARGAS8U2dJNN8I7kB+6BGkLq7r@public.gmane.org> wrote:
>> The main grief one could have with my scheme is the naming of irq_host
>> which has confused people in the past. It should probably be irq_domain
>> to make clear what it is. It generally have a 1:1 relationship to the
>> irq_chip but there are cases where that isn't the case (essentially
>> where you have multiple irq_chip per domain) for various reasons so it's
>> better to keep those separate.
>>
>
>How do we handle multiplexed interrupts ? For example a single interrupt line
>representing multple irq sources.
>We have ARM systems with  single interrupt line on a VIC  muxed to
>192 different GPIO sources (each capable of generating interrupts). For such a
>system the virq to hw irq mapping can get complex.

Assign a separate irq number to each gpio.  In effect, this makes the gpio controller an irq controller.

g.

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