From 2c83769b2f29d6c6b93d1e0f0c23bbd0ce84b241 Mon Sep 17 00:00:00 2001 From: Khairul Anuar Romli Date: Wed, 15 Oct 2025 08:13:38 +0800 Subject: [PATCH] dt-bindings: dma: snps,dw-axi-dmac: Add iommu property Agilex5 integrates an ARM SMMU v3 (System Memory Management Unit) with dedicated Translation Buffer Units (TBUs) assigned to various peripherals, including the Synopsys DesignWare AXI DMA controller. Each TBU handles address translation for its associated device by mapping stream IDs to memory access permissions and virtual-to-physical address mappings via the SMMU core. The DesignWare AXI DMAC instances on Agilex5 are connected to their respective TBUs. These TBUs forward DMA transactions from the controller through the SMMU, enabling IOMMU-based features such as: - Address translation for DMA operations - Isolation and protection of memory regions accessed by the DMA controller - Support for secure and virtualized environments through enforced access control To support this configuration, the `iommus` property must be added to the binding schema for `snps,dw-axi-dmac`. This allows the device tree to associate each DMA controller with the correct SMMU stream ID, enabling the Linux IOMMU framework to configure translation contexts at runtime. This change documents the IOMMU support for the DMA controller on Agilex5 and allows proper integration with the SMMUv3 hardware. Signed-off-by: Adrian Ng Ho Yin Signed-off-by: Khairul Anuar Romli Reviewed-by: Krzysztof Kozlowski Signed-off-by: Dinh Nguyen --- Documentation/devicetree/bindings/dma/snps,dw-axi-dmac.yaml | 3 +++ 1 file changed, 3 insertions(+) diff --git a/Documentation/devicetree/bindings/dma/snps,dw-axi-dmac.yaml b/Documentation/devicetree/bindings/dma/snps,dw-axi-dmac.yaml index 935735a59afd4..a393a33c8908f 100644 --- a/Documentation/devicetree/bindings/dma/snps,dw-axi-dmac.yaml +++ b/Documentation/devicetree/bindings/dma/snps,dw-axi-dmac.yaml @@ -42,6 +42,9 @@ properties: minItems: 1 maxItems: 8 + iommus: + maxItems: 1 + clocks: items: - description: Bus Clock -- 2.47.3