Re: [PATCH v3 4/8] dt-bindings: iommu: Add spacemit/t100 features

Conor Dooley
2026-02-04T17:37:14Z

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On Wed, Feb 04, 2026 at 05:09:12PM +0800, Lv Zheng wrote:
> Adds device tree bindings for SpacemiT T100 specific features by
> introducing spacemit,100 compatible. T100 contains distributed IOATCs,
> each of which exposes pmiv interrupt.
>
> Signed-off-by: Lv Zheng <lv.zheng@linux.spacemit.com>
> Signed-off-by: Jingyu Li <joey.li@spacemit.com>
> ---
> .../bindings/iommu/riscv,iommu.yaml | 37 +++++++++++++++++++
> 1 file changed, 37 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/iommu/riscv,iommu.yaml b/Documentation/devicetree/bindings/iommu/riscv,iommu.yaml
> index d4838c3b3741..2da3456e7402 100644
> --- a/Documentation/devicetree/bindings/iommu/riscv,iommu.yaml
> +++ b/Documentation/devicetree/bindings/iommu/riscv,iommu.yaml
> @@ -32,6 +32,12 @@ properties:
> # should be specified along with 'reg' property providing MMIO location.
> compatible:
> oneOf:
> + - description: SpacemiT distributed IOMMUs
> + items:
> + - enum:
> + - spacemit,t100
> + - const: spacemit,riscv-iommu

What actually is the t100? Is it an SoC or is it the name of the core
complex IP that spacemit is using in multiple SoCs?

> + - const: riscv,iommu
> - items:
> - enum:
> - qemu,riscv-iommu
> @@ -75,6 +81,23 @@ required:
>
> additionalProperties: false
>
> +select: false

Why is this here? It just breaks the whole binding.
pw-bot: changes-requested

> +
> +allOf:
> + - if:
> + properties:
> + compatible:
> + contains:
> + const: spacemit,riscv-iommu
> + then:
> + properties:
> + interrupts:
> + maxItems: 68

This isn't right. You would need to make the interrupts property itself
have maxItems: 68, then add an else to this conditional that has
maxItems: 4. What you've done just doesn't work, and if you removed the
"select: false: you'd see.

> + description:
> + SpacemiT distributed IOMMU includes additional interrupts for
> + IOATCs. Each IOATC exposes pmiv wired vector as standalone
> + interrupt and the maximum number of IOATCs can be up to 64.
> +
> examples:
> - |+
> /* Example 1 (IOMMU device with wired interrupts) */
> @@ -145,3 +168,17 @@ examples:
> };
> };
> };
> +
> + - |+
> + /* Example 5 (SpacemiT distributed IOMMU) */
> + #include <dt-bindings/interrupt-controller/irq.h>
> +
> + iommu4: iommu@1bccd000 {

Remove the iommu4 label, there's no references to it.

Cheers,
Conor.

> + compatible = "spacemit,t100", "spacemit,riscv-iommu", "riscv,iommu";
> + reg = <0x1bccd000 0x1000>;
> + interrupts = <58 IRQ_TYPE_LEVEL_HIGH>, <58 IRQ_TYPE_LEVEL_HIGH>,
> + <58 IRQ_TYPE_LEVEL_HIGH>, <58 IRQ_TYPE_LEVEL_HIGH>,
> + <62 IRQ_TYPE_LEVEL_HIGH>, <63 IRQ_TYPE_LEVEL_HIGH>;
> + interrupt-parent = <&saplic>;
> + #iommu-cells = <0x01>;
> + };
> --
> 2.43.0
>

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