Subject: [RFC 2/5] ARM: dts: Add Cross Trigger Interface binding

From: [email-masked] (Jon Hunter)
Date: Wed, 12 Dec 2012 17:23:59 -0600

On 12/12/2012 04:12 PM, Rob Herring wrote:
> On 12/12/2012 03:43 PM, Jon Hunter wrote:
>> Adds a device-tree binding for the ARM Cross Trigger Interface (CTI).
>> The ARM Cross Trigger Interface provides a way to route events between
>> processor modules. For example, on OMAP4430 we use the CTI module to
>> route PMU events to the GIC interrupt module.
> 
> Do you need to describe the PMU-CTI-GIC connection in DT?

We definitely could. This is achieved by mapping a trigger-input to a
trigger-output. So we could list the trigger outputs and inputs in the
binding. For omap4430 we would have ...

arm,cti-trigin = <0 1 2 3 4 5 6>;
arm,cti-trigin-names =  "dbgack", "pmuirq", "ptmextout0",
			"ptmextout1", "commtx", "commrx",
			"ptmtrigger";
arm,cti-trigout = <0 1 2 3 4 6 7>;
arm,cti-trigout-names = "edbgreq", "ptmextin0", "ptmextin1",
			"ptmextin2", "ptmextin3","mpuirq",
			"dbgrestart";

So to map the PMU to GIC, we would map the "pmuirq" trigger input to the
"mpuirq" trigger output. Then we could setup the mapping by name instead
of index.

Let me know what you think about that.

Cheers
Jon