On Sat, Oct 06, 2018 at 11:29:29AM -0500, 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@xxxxxx> > > --- > > .../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. I'm not sure I follow all the terminology here of type, subtype, "dst host irq", etc. It looks to me like you should be using interrupt-map property. Rob > > [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 > -- > Regards, > Nishanth Menon
