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    SubjectRe: [PATCH v2 01/14] dt-bindings: remoteproc: Add TI PRUSS bindings
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    On 14/02/2019 15:44, Roger Quadros wrote:
    > On 14/02/19 14:52, Marc Zyngier wrote:
    >> On Thu, 14 Feb 2019 10:55:10 +0000,
    >> Roger Quadros <rogerq@ti.com> wrote:
    >>>
    >>>
    >>> On 14/02/19 10:37, Linus Walleij wrote:
    >>>> On Thu, Feb 14, 2019 at 4:13 AM Suman Anna <s-anna@ti.com> wrote:
    >>>>> [Me]
    >>>>
    >>>>>> To be able to use hierarchical interrupt domain in the kernel, the top
    >>>>>> interrupt controller must use the hierarchical (v2) irqdomain, so
    >>>>>> if this is anything else than the ARM GIC it will be an interesting
    >>>>>> undertaking to handle this.
    >>>>>
    >>>>> These are interrupt lines coming towards the host processor running
    >>>>> Linux and are directly connected to the ARM GIC. This INTC module is
    >>>>> actually an PRUSS internal interrupt controller that can take in 64 (on
    >>>>> most SoCs) external events/interrupt sources and multiplexing them
    >>>>> through two layers of many-to-one events-to-intr channels &
    >>>>> intr-channels-to-host interrupts. Couple of the host interrupts go to
    >>>>> the PRU cores themselves while the remaining ones come out of the IP to
    >>>>> connect to other GICs in the SoC.
    >>>>
    >>>> If the muxing is static (like set up once at probe) so that while
    >>>> the system is running, there is one and one only event mapped to
    >>>> the GIC from the component below it, then it is hierarchical.
    >>>
    >>> This is how it looks.
    >>>
    >>> [GIC]<---8---[INTC]<---64---[events from peripherals]
    >>>
    >>> The 8 interrupt lines from INTC to the GIC are 1:1 mapped and fixed
    >>> per SoC. The muxing between 64 inputs to INTC and its 8 outputs are
    >>> programmable and might not necessarily be static per boot/probe as
    >>> it depends on what firmware is loaded on the PRU.
    >>
    >> But the point is that at any given time, there are at most 8 out of 64
    >> inputs that are used, right? You *never* end-up with two (or more) of
    >> these "events" being multiplexed on a single output line.
    >>
    >
    > Since the INTC's internal logic allows assigning more than one event each outputs,
    > at most all 64 events can be assigned to one output or distributed among the 8 outputs.

    OK. Do you get individual masking and status bits for each input?

    Thanks,

    M.
    --
    Jazz is not dead. It just smells funny...

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