Re: [PATCH v2 12/16] dt-bindings/interrupt-controller: update Marvell ICU bindings

Rob Herring
2018-06-05T20:29:08Z

On Tue, May 22, 2018 at 11:40:38AM +0200, Miquel Raynal wrote:
> Change the documentation to reflect the new bindings used for Marvell
> ICU. This involves describing each interrupt group as a subnode of the
> ICU node. Each of them having their own compatible.

Need to explain why you need to do this and why breaking backwards
compatibility is okay.

>
> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
> ---
> .../bindings/interrupt-controller/marvell,icu.txt | 81 ++++++++++++++++++----
> 1 file changed, 69 insertions(+), 12 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/interrupt-controller/marvell,icu.txt b/Documentation/devicetree/bindings/interrupt-controller/marvell,icu.txt
> index 649b7ec9d9b1..6f7e4355b3d8 100644
> --- a/Documentation/devicetree/bindings/interrupt-controller/marvell,icu.txt
> +++ b/Documentation/devicetree/bindings/interrupt-controller/marvell,icu.txt
> @@ -5,6 +5,8 @@ The Marvell ICU (Interrupt Consolidation Unit) controller is
> responsible for collecting all wired-interrupt sources in the CP and
> communicating them to the GIC in the AP, the unit translates interrupt
> requests on input wires to MSG memory mapped transactions to the GIC.
> +These messages will access a different GIC memory area depending on
> +their type (NSR, SR, SEI, REI, etc).
>
> Required properties:
>
> @@ -12,20 +14,19 @@ Required properties:
>
> - reg: Should contain ICU registers location and length.
>
> +Subnodes: Each group of interrupt is declared as a subnode of the ICU,
> +with their own compatible.
> +
> +Required properties for the icu_nsr/icu_sei subnodes:
> +
> +- compatible: Should be "marvell,cp110-icu-nsr" or "marvell,cp110-icu-sei".
> +
> - #interrupt-cells: Specifies the number of cells needed to encode an
> - interrupt source. The value shall be 3.
> + interrupt source. The value shall be 2.
>
> - The 1st cell is the group type of the ICU interrupt. Possible group
> - types are:
> + The 1st cell is the index of the interrupt in the ICU unit.
>
> - ICU_GRP_NSR (0x0) : Shared peripheral interrupt, non-secure
> - ICU_GRP_SR (0x1) : Shared peripheral interrupt, secure
> - ICU_GRP_SEI (0x4) : System error interrupt
> - ICU_GRP_REI (0x5) : RAM error interrupt

What happens to SR and REI interrupts?

> -
> - The 2nd cell is the index of the interrupt in the ICU unit.
> -
> - The 3rd cell is the type of the interrupt. See arm,gic.txt for
> + The 2nd cell is the type of the interrupt. See arm,gic.txt for
> details.
>
> - interrupt-controller: Identifies the node as an interrupt
> @@ -35,17 +36,73 @@ Required properties:
> that allows to trigger interrupts using MSG memory mapped
> transactions.
>
> +Note: each 'interrupts' property referring to any 'icu_xxx' node shall
> + have a different number within [0:206].
> +
> Example:
>
> icu: interrupt-controller@1e0000 {
> compatible = "marvell,cp110-icu";
> reg = <0x1e0000 0x440>;
> +
> + CP110_LABEL(icu_nsr): icu-nsr {

'interrupt-controller' is the proper node name. Is there no register
range associated sub nodes?

> + compatible = "marvell,cp110-icu-nsr";
> + #interrupt-cells = <2>;
> + interrupt-controller;
> + msi-parent = <&gicp>;
> + };
> +
> + CP110_LABEL(icu_sei): icu-sei {
> + compatible = "marvell,cp110-icu-sei";
> + #interrupt-cells = <2>;
> + interrupt-controller;
> + msi-parent = <&sei>;
> + };

Mixture of tabs and spaces.

> +};
> +
> +node1 {
> + interrupt-parent = <&icu_nsr>;
> + interrupts = <106 IRQ_TYPE_LEVEL_HIGH>;
> +};
> +
> +node2 {
> + interrupt-parent = <&icu_sei>;
> + interrupts = <107 IRQ_TYPE_LEVEL_HIGH>;
> +};
> +
> +/* Would not work with the above nodes */
> +node3 {
> + interrupt-parent = <&icu_nsr>;
> + interrupts = <107 IRQ_TYPE_LEVEL_HIGH>;
> +};
> +
> +Note on legacy bindings:
> +Before using a subnode for each domain, only NSR were
> +supported. Bindings were different in this way:
> +
> +- #interrupt-cells: The value was 3.
> + The 1st cell was the group type of the ICU interrupt. Possible
> + group types were:
> + ICU_GRP_NSR (0x0) : Shared peripheral interrupt, non-secure
> + ICU_GRP_SR (0x1) : Shared peripheral interrupt, secure
> + ICU_GRP_SEI (0x4) : System error interrupt
> + ICU_GRP_REI (0x5) : RAM error interrupt
> + The 2nd cell was the index of the interrupt in the ICU unit.
> + The 3rd cell was the type of the interrupt. See arm,gic.txt for
> + details.
> +
> +Example:
> +
> +icu: interrupt-controller@1e0000 {
> + compatible = "marvell,cp110-icu";
> + reg = <0x1e0000 0x440>;
> +
> #interrupt-cells = <3>;
> interrupt-controller;
> msi-parent = <&gicp>;
> };
>
> -usb3h0: usb3@500000 {
> +node1 {
> interrupt-parent = <&icu>;
> interrupts = <ICU_GRP_NSR 106 IRQ_TYPE_LEVEL_HIGH>;
> };
> --
> 2.14.1
>