linux/Documentation/devicetree/bindings/interrupt-controller/marvell,icu.txt
Miquel Raynal 548ce8156f dt-bindings/interrupt-controller: Update Marvell ICU bindings
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.

The DT binding documentation still documents the legacy binding, where
there was a single node with no subnode.

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-10-02 12:02:20 +01:00

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Marvell ICU Interrupt Controller
--------------------------------
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:
- compatible: Should be "marvell,cp110-icu"
- 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 one of:
* "marvell,cp110-icu-nsr"
* "marvell,cp110-icu-sr"
* "marvell,cp110-icu-sei"
* "marvell,cp110-icu-rei"
- #interrupt-cells: Specifies the number of cells needed to encode an
interrupt source. The value shall be 2.
The 1st cell is the index of the interrupt in the ICU unit.
The 2nd cell is the type of the interrupt. See arm,gic.txt for
details.
- interrupt-controller: Identifies the node as an interrupt
controller.
- msi-parent: Should point to the GICP controller, the GIC extension
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): interrupt-controller@10 {
compatible = "marvell,cp110-icu-nsr";
reg = <0x10 0x20>;
#interrupt-cells = <2>;
interrupt-controller;
msi-parent = <&gicp>;
};
CP110_LABEL(icu_sei): interrupt-controller@50 {
compatible = "marvell,cp110-icu-sei";
reg = <0x50 0x10>;
#interrupt-cells = <2>;
interrupt-controller;
msi-parent = <&sei>;
};
};
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>;
};
The legacy 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>;
};
node1 {
interrupt-parent = <&icu>;
interrupts = <ICU_GRP_NSR 106 IRQ_TYPE_LEVEL_HIGH>;
};