Documentation/devicetree/bindings/virtio/mmio.txt

   1 * virtio memory mapped device
   2
   3 See http://ozlabs.org/~rusty/virtio-spec/ for more details.
   4
   5 Required properties:
   6
   7 - compatible:   "virtio,mmio" compatibility string
   8 - reg:          control registers base address and size including configuration space
   9 - interrupts:   interrupt generated by the device
  10
  11 Required properties for virtio-iommu:
  12
  13 - #iommu-cells: When the node corresponds to a virtio-iommu device, it is
  14                 linked to DMA masters using the "iommus" or "iommu-map"
  15                 properties [1][2]. #iommu-cells specifies the size of the
  16                 "iommus" property. For virtio-iommu #iommu-cells must be
  17                 1, each cell describing a single endpoint ID.
  18
  19 Optional properties:
  20
  21 - iommus:       If the device accesses memory through an IOMMU, it should
  22                 have an "iommus" property [1]. Since virtio-iommu itself
  23                 does not access memory through an IOMMU, the "virtio,mmio"
  24                 node cannot have both an "#iommu-cells" and an "iommus"
  25                 property.
  26
  27 Example:
  28
  29         virtio_block@3000 {
  30                 compatible = "virtio,mmio";
  31                 reg = <0x3000 0x100>;
  32                 interrupts = <41>;
  33
  34                 /* Device has endpoint ID 23 */
  35                 iommus = <&viommu 23>
  36         }
  37
  38         viommu: iommu@3100 {
  39                 compatible = "virtio,mmio";
  40                 reg = <0x3100 0x100>;
  41                 interrupts = <42>;
  42
  43                 #iommu-cells = <1>
  44         }
  45
  46 [1] Documentation/devicetree/bindings/iommu/iommu.txt
  47 [2] Documentation/devicetree/bindings/pci/pci-iommu.txt