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Diffstat (limited to 'Documentation/devicetree/bindings/virtio/mmio.txt')
| -rw-r--r-- | Documentation/devicetree/bindings/virtio/mmio.txt | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/virtio/mmio.txt b/Documentation/devicetree/bindings/virtio/mmio.txt new file mode 100644 index 000000000..0a575f329 --- /dev/null +++ b/Documentation/devicetree/bindings/virtio/mmio.txt @@ -0,0 +1,47 @@ +* virtio memory mapped device + +See https://ozlabs.org/~rusty/virtio-spec/ for more details. + +Required properties: + +- compatible: "virtio,mmio" compatibility string +- reg: control registers base address and size including configuration space +- interrupts: interrupt generated by the device + +Required properties for virtio-iommu: + +- #iommu-cells: When the node corresponds to a virtio-iommu device, it is + linked to DMA masters using the "iommus" or "iommu-map" + properties [1][2]. #iommu-cells specifies the size of the + "iommus" property. For virtio-iommu #iommu-cells must be + 1, each cell describing a single endpoint ID. + +Optional properties: + +- iommus: If the device accesses memory through an IOMMU, it should + have an "iommus" property [1]. Since virtio-iommu itself + does not access memory through an IOMMU, the "virtio,mmio" + node cannot have both an "#iommu-cells" and an "iommus" + property. + +Example: + + virtio_block@3000 { + compatible = "virtio,mmio"; + reg = <0x3000 0x100>; + interrupts = <41>; + + /* Device has endpoint ID 23 */ + iommus = <&viommu 23> + } + + viommu: iommu@3100 { + compatible = "virtio,mmio"; + reg = <0x3100 0x100>; + interrupts = <42>; + + #iommu-cells = <1> + } + +[1] Documentation/devicetree/bindings/iommu/iommu.txt +[2] Documentation/devicetree/bindings/pci/pci-iommu.txt |