Hi Tony, On 2/15/2019 9:46 PM, Tony Lindgren wrote: > Hi, > > * Lokesh Vutla <lokeshvutla@xxxxxx> [190214 18:03]: >> On 2/14/2019 11:16 PM, Tony Lindgren wrote: >>> 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
