Messages in this thread |  | | Subject | Re: [PATCH 1/2] dt-bindings: irqchip: Introduce TISCI Interrupt router bindings | From | Lokesh Vutla <> | Date | Mon, 15 Oct 2018 16:35:25 +0530 |
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Hi Rob, DT maintainers,
On Saturday 06 October 2018 09:59 PM, Nishanth Menon wrote: > On 12:58-20181006, Lokesh Vutla wrote: >> Add the DT binding documentation for Interrupt router driver. >> >> Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com> >> --- >> .../interrupt-controller/ti,sci-intr.txt | 83 +++++++++++++++++++ >> MAINTAINERS | 1 + >> 2 files changed, 84 insertions(+) >> create mode 100644 Documentation/devicetree/bindings/interrupt-controller/ti,sci-intr.txt >> >> diff --git a/Documentation/devicetree/bindings/interrupt-controller/ti,sci-intr.txt b/Documentation/devicetree/bindings/interrupt-controller/ti,sci-intr.txt >> new file mode 100644 >> index 000000000000..681ca53cc5fb >> --- /dev/null >> +++ b/Documentation/devicetree/bindings/interrupt-controller/ti,sci-intr.txt >> @@ -0,0 +1,83 @@ >> +Texas Instruments K3 Interrupt Router >> +===================================== >> + >> +The Interrupt Router (INTR) module provides a mechanism to mux M >> +interrupt inputs to N interrupt outputs, where all M inputs are selectable >> +to be driven per N output. There is one register per output (MUXCNTL_N) that >> +controls the selection. >> + >> + >> + Interrupt Router >> + +----------------------+ >> + | Inputs Outputs | >> + +-------+ | +------+ | >> + | GPIO |----------->| | irq0 | | Host IRQ >> + +-------+ | +------+ | controller >> + | . +-----+ | +-------+ >> + +-------+ | . | 0 | |----->| GIC | >> + | INTA |----------->| . +-----+ | +-------+ >> + +-------+ | . . | >> + | +------+ . | >> + | | irqM | +-----+ | >> + | +------+ | N | | >> + | +-----+ | >> + +----------------------+ >> + >> +Configuration of these MUXCNTL_N registers is done by a system controller >> +(like the Device Memory and Security Controller on K3 AM654 SoC). System >> +controller will keep track of the used and unused registers within the Router. >> +Driver should request the system controller to get the range of GIC IRQs >> +assigned to the requesting hosts. It is the drivers responsibility to keep >> +track of GIC IRQs. >> + >> +Communication between the host processor running an OS and the system >> +controller happens through a protocol called TI System Control Interface >> +(TISCI protocol). For more details refer: >> +Documentation/devicetree/bindings/arm/keystone/ti,sci.txt >> + >> +TISCI Interrupt Router Node: >> +---------------------------- >> +- compatible: Must be "ti,sci-intr". >> +- interrupt-controller: Identifies the node as an interrupt controller >> +- #interrupt-cells: Specifies the number of cells needed to encode an >> + interrupt source. The value should be 3. >> + First cell should contain the TISCI device ID of source >> + Second cell should contain the interrupt source offset >> + within the device >> + Third cell specifies the trigger type as defined >> + in interrupts.txt in this directory. >> +- interrupt-parent: phandle of irq parent for TISCI intr. The parent must >> + use the same interrupt-cells format as GIC. >> +- ti,sci: Phandle to TI-SCI compatible System controller node. >> +- ti,sci-dst-id: TISCI device ID of the destination IRQ controller. >> +- ti,sci-rm-range-girq: Tuple corresponding to unique TISCI resource type that >> + defines the dst host irq ranges assigned to this >> + interrupt router from this host context. >> + Tuple should be of format <type subtype>. >> + > > Rob, DT maintainers, > > I'd like a feedback from DT maintainers on this 'range' topic. > > TISCI Firmware [1] currently seems to define a type corresponding to a > device ID[2]. in AM6 device, for example, this is different, however > have a 1 to 1 correspondence. However, there is expectation that type will > end up as device ID in a future SoC. > > While this is subject to much debate internally, I'd like some feedback if this > is OK from Device tree representation - it is true that Firmware does > look at it as type, however in some future SoC, it could be that the > values themselves may correspond one to one with a device id -> The > original wish was that types might be something reusable across SoCs, > but that is turning out to be more of a theoretical wish than any thing > practical. > > [1]http://software-dl.ti.com/tisci/esd/latest/5_soc_doc/am6x/resasg_types.html > [2]http://software-dl.ti.com/tisci/esd/latest/5_soc_doc/am6x/devices.html
Any help on this topic?
Thanks and regards, Lokesh
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