On Mon, Feb 20, 2023 at 10:32:57AM +0000, Conor Dooley wrote: > On Mon, Feb 20, 2023 at 10:06:49AM +0530, Anup Patel wrote: > > On Thu, Jan 5, 2023 at 3:47 AM Conor Dooley <conor@xxxxxxxxxx> wrote: > > > On Tue, Jan 03, 2023 at 07:44:06PM +0530, Anup Patel wrote: > > > > We add DT bindings document for RISC-V advanced platform level > > > > interrupt controller (APLIC) defined by the RISC-V advanced > > > > interrupt architecture (AIA) specification. > > > > > > > > Signed-off-by: Anup Patel <apatel@xxxxxxxxxxxxxxxx> > > > > --- > > > > .../interrupt-controller/riscv,aplic.yaml | 159 ++++++++++++++++++ > > > > 1 file changed, 159 insertions(+) > > > > create mode 100644 Documentation/devicetree/bindings/interrupt-controller/riscv,aplic.yaml > > > > I'm sorry Anup, but this child versus delegate thing is still not clear > > > to me binding wise. See below. > > > > There are two different information in-context of APLIC domain: > > > > 1) HW child domain numbering: If an APLIC domain has N children > > then HW will have a fixed child index for each of the N children > > in the range 0 to N-1. This HW child index is required at the time > > of setting up interrupt delegation in sourcecfgX registers. The > > "riscv,children" DT property helps firmware (or bootloader) find > > the total number of child APLIC domains and corresponding > > HW child index number. > > > > 2) IRQ delegation to child domains: An APLIC domain can delegate > > any IRQ range(s) to a particular APLIC child domain. The > > "riscv,delegate" DT property is simply a table where we have > > one row for each IRQ range which is delegated to some child > > APLIC domain. This property is more of a system setting fixed > > by the RISC-V platform vendor. > > Thanks for the explanations. It's been a while since my brain swapped > this stuff out, but I think delegate/child makes sense to me now. > Just don't ask me to write the dt entry as proof... Having looked at Dramforever's QEMU dtb dump a bit more and your responses to her, I think that I have "come to terms" with it now actually. I suppose when the next version comes around I'll make sure that I arrive in the same ballpark that QEMU does, based off the descriptions etc in the binding. Thanks!
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