Re: Subject: L2x0 OF properties do not include interrupt #

Will Deacon
2011-08-11T13:10:06Z

On Thu, Aug 11, 2011 at 02:05:11PM +0100, Arnd Bergmann wrote:
> On Wednesday 10 August 2011, Will Deacon wrote:
> > I was hoping that it was possible to have separate properties which describe
> > the interrupt. So you could have something like pmu-interrupt <75> and
> > abort-interrupt <76> rather than interrupts <75, 76>.
>
> Ok, I see.
>
> > I've not played with DT bindings before though, so if it's usually done with
> > an ordered list then so be it!
>
> A lot of the code assumes that the property is called 'interrupts' and that
> it contains a fixed-length array of interrupt numbers, each for one specific
> purpose.

Ok, I wondered if something like that might be the case.

> Given that we have so many different meanings for the interrupts, I'm
> not sure how this would work best in this case. According to
> http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0246f/CHDFHCFJ.html
> this looks like a nested interrupt controller, i.e. the L2CC has its own mask
> and status register with bits for each one of them. We could model these by
> describing the l2cc interrupt controller with these registers and listing all
> nine of the current inputs. I suspect however that it would be easier to just
> assume that there is only one line for now, and treat the l2cc as a single
> interrupt source with an internal status register.

Given that this binding is only for the l2x0 / pl310 and I don't know of any
implementation where > 1 interrupt line is wired up, I'm happy to assume a
single combined interrupt line for now.

Cheers,

Will