On 12:58-20181006, Lokesh Vutla wrote: > Add the DT binding documentation for Interrupt router driver. > > Signed-off-by: Lokesh Vutla <lokeshvu...@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 -- Regards, Nishanth Menon
