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

Will Deacon
2011-08-11T15:38:28Z

On Thu, Aug 11, 2011 at 04:32:08PM +0100, Rob Herring wrote:
> On 08/11/2011 08:09 AM, Will Deacon wrote:
> > 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.
> >
>
> I know of one. Although, we have the combined interrupt as well. The
> binding should allow either way and specify the order. If the event
> counter interrupt is 1st, then it should be the same to s/w.

You mean putting the combined interrupt first? If so, we may as well just
specify that until somebody builds a platform that doesn't have it.

Will