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author | Will Deacon <will.deacon@arm.com> | 2013-06-24 18:31:24 +0100 |
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committer | Joerg Roedel <joro@8bytes.org> | 2013-06-25 23:33:43 +0200 |
commit | 98c33c5a971bbca31160e5e4a362496c4d702357 (patch) | |
tree | 70339db569080639da81adac669cf09f2335fda9 /Documentation/devicetree | |
parent | 9e895ace5d82df8929b16f58e9f515f6d54ab82d (diff) | |
download | op-kernel-dev-98c33c5a971bbca31160e5e4a362496c4d702357.zip op-kernel-dev-98c33c5a971bbca31160e5e4a362496c4d702357.tar.gz |
documentation/iommu: Add description of ARM System MMU binding
This patch adds a description of the device tree binding for the ARM
System MMU architecture.
Cc: Rob Herring <robherring2@gmail.com>
Cc: Andreas Herrmann <andreas.herrmann@calxeda.com>
Cc: Joerg Roedel <joro@8bytes.org>
Acked-by: Grant Likely <grant.likely@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Acked-by: Andreas Herrmann <andreas.herrmann@calxeda.com>
Signed-off-by: Joerg Roedel <joro@8bytes.org>
Diffstat (limited to 'Documentation/devicetree')
-rw-r--r-- | Documentation/devicetree/bindings/iommu/arm,smmu.txt | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/iommu/arm,smmu.txt b/Documentation/devicetree/bindings/iommu/arm,smmu.txt new file mode 100644 index 0000000..e34c6cd --- /dev/null +++ b/Documentation/devicetree/bindings/iommu/arm,smmu.txt @@ -0,0 +1,70 @@ +* ARM System MMU Architecture Implementation + +ARM SoCs may contain an implementation of the ARM System Memory +Management Unit Architecture, which can be used to provide 1 or 2 stages +of address translation to bus masters external to the CPU. + +The SMMU may also raise interrupts in response to various fault +conditions. + +** System MMU required properties: + +- compatible : Should be one of: + + "arm,smmu-v1" + "arm,smmu-v2" + "arm,mmu-400" + "arm,mmu-500" + + depending on the particular implementation and/or the + version of the architecture implemented. + +- reg : Base address and size of the SMMU. + +- #global-interrupts : The number of global interrupts exposed by the + device. + +- interrupts : Interrupt list, with the first #global-irqs entries + corresponding to the global interrupts and any + following entries corresponding to context interrupts, + specified in order of their indexing by the SMMU. + + For SMMUv2 implementations, there must be exactly one + interrupt per context bank. In the case of a single, + combined interrupt, it must be listed multiple times. + +- mmu-masters : A list of phandles to device nodes representing bus + masters for which the SMMU can provide a translation + and their corresponding StreamIDs (see example below). + Each device node linked from this list must have a + "#stream-id-cells" property, indicating the number of + StreamIDs associated with it. + +** System MMU optional properties: + +- smmu-parent : When multiple SMMUs are chained together, this + property can be used to provide a phandle to the + parent SMMU (that is the next SMMU on the path going + from the mmu-masters towards memory) node for this + SMMU. + +Example: + + smmu { + compatible = "arm,smmu-v1"; + reg = <0xba5e0000 0x10000>; + #global-interrupts = <2>; + interrupts = <0 32 4>, + <0 33 4>, + <0 34 4>, /* This is the first context interrupt */ + <0 35 4>, + <0 36 4>, + <0 37 4>; + + /* + * Two DMA controllers, the first with two StreamIDs (0xd01d + * and 0xd01e) and the second with only one (0xd11c). + */ + mmu-masters = <&dma0 0xd01d 0xd01e>, + <&dma1 0xd11c>; + }; |