Re: [PATCH v2 06/10] dt-bindings: irqchip: Introduce TISCI Interrupt router bindings

Rob Herring
2018-10-25T18:46:02Z

On Thu, Oct 18, 2018 at 09:10:13PM +0530, Lokesh Vutla wrote:
> Add the DT binding documentation for Interrupt router driver.
>
> Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
> ---
> Changes since v1:
> - Drop dependency on GIC
> - Updated supported interrupt types.
>
> .../interrupt-controller/ti,sci-intr.txt | 81 +++++++++++++++++++
> MAINTAINERS | 1 +
> 2 files changed, 82 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..276bb4f0ad12
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/interrupt-controller/ti,sci-intr.txt
> @@ -0,0 +1,81 @@
> +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 | |----->| IRQ |
> + | 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 Host 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. Only level
> + sensitive trigger types are supported.
> +- interrupt-parent: phandle of irq parent for TISCI intr.

This is implied and could be in a parent node.

> +- 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: TISCI subtype id representing the host irqs assigned
> + to this interrupt router.

These need a better explanation and there's still some questions on v1
asked of me that I tried to answer.

> +
> +Example:
> +--------
> +The following example demonstrates both interrupt router node and the consumer
> +node(main gpio) on the AM654 SoC:
> +
> +main_intr: interrupt-controller@1 {
> + compatible = "ti,sci-intr";
> + interrupt-controller;
> + interrupt-parent = <&gic>;
> + #interrupt-cells = <3>;
> + ti,sci = <&dmsc>;
> + ti,sci-dst-id = <56>;
> + ti,sci-rm-range-girq = <0x1>;
> +};
> +
> +main_gpio0: main_gpio0@600000 {

gpio@...

> + ...
> + interrupt-parent = <&main_intr>;
> + interrupts = <57 256 IRQ_TYPE_EDGE_RISING>,
> + <57 257 IRQ_TYPE_EDGE_RISING>,
> + <57 258 IRQ_TYPE_EDGE_RISING>,
> + <57 259 IRQ_TYPE_EDGE_RISING>,
> + <57 260 IRQ_TYPE_EDGE_RISING>,
> + <57 261 IRQ_TYPE_EDGE_RISING>;
> + ...
> +};
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 06966772cad4..710cf728b9d0 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -14686,6 +14686,7 @@ F: Documentation/devicetree/bindings/reset/ti,sci-reset.txt
> F: Documentation/devicetree/bindings/clock/ti,sci-clk.txt
> F: drivers/clk/keystone/sci-clk.c
> F: drivers/reset/reset-ti-sci.c
> +F: Documentation/devicetree/bindings/interrupt-controller/ti,sci-intr.txt
>
> THANKO'S RAREMONO AM/FM/SW RADIO RECEIVER USB DRIVER
> M: Hans Verkuil <hverkuil@xs4all.nl>
> --
> 2.19.1
>