Hi Tony,

On 2/15/2019 9:46 PM, Tony Lindgren wrote:

Hi,

* Lokesh Vutla [off-list ref] [190214 18:03]:

quoted

On 2/14/2019 11:16 PM, Tony Lindgren wrote:

quoted

But I'd rather have a proper hardware based phandle + index
type mapping in the dts if possible though.

The idea about sysfw here is that Linux is not aware of anything about
this device(Interrupt Router). It cannot even access any of its
registers. As a user Linux should know who is the parent to which the
Interrut router output should be configured. Then query sysfw about the
range of gic irqs allocated to it. Now for configuration, Linux should
pass the the input to interrupt router, gic irq no, and gic id(by which
sysfw uniquely identifies GIC interrupt controller with the SoC).  Based
on these parameters Interrupt Router registers gets configured.

If the interrupt router hardawre is hidden away from Linux,
just leave it out of the device tree completely and have the
interrupt controller driver request the routing.

Yes while requesting you should at-least specify which is your
destination interrupt-controller Else how does the sysfw even know to
whom the requester wants the routing to happen to. You do know that we
are dealing with a heterogeneous system where there are more the one
destination interrupt controllers(GIC, R5 VIM  etc etc..). This is what
the DT property is specifying and we cannot query a device based on a name.

The dts node for the interrupt controller should describe a
proper Linux device, that is with reg entries and so on.

You are asking to just keep the compatible property :)

I am no where denying that. But the cases where the firmware does the
configuration DT spec[1] clearly mentions about the interface.

Please take a look at arm-psci devicetree binding documentation where
the function ids are represented using which each psci function is invoked.

[1]
https://github.com/devicetree-org/devicetree-specification/releases/download/v0.2/devicetree-specification-v0.2.pdf

Thanks and regards,
Lokesh