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-rw-r--r-- | Documentation/devicetree/bindings/iommu/apple,sart.yaml | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/iommu/apple,sart.yaml b/Documentation/devicetree/bindings/iommu/apple,sart.yaml new file mode 100644 index 000000000..1524fa309 --- /dev/null +++ b/Documentation/devicetree/bindings/iommu/apple,sart.yaml @@ -0,0 +1,52 @@ +# SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/iommu/apple,sart.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Apple SART DMA address filter + +maintainers: + - Sven Peter <sven@svenpeter.dev> + +description: + Apple SART is a simple address filter for DMA transactions. Regions of + physical memory must be added to the SART's allow list before any + DMA can target these. Unlike a proper IOMMU no remapping can be done and + special support in the consumer driver is required since not all DMA + transactions of a single device are subject to SART filtering. + + SART1 has first been used since at least the A11 (iPhone 8 and iPhone X) + and allows 36 bit of physical address space and filter entries with sizes + up to 24 bit. + + SART2, first seen in A14 and M1, allows 36 bit of physical address space + and filter entry size up to 36 bit. + + SART3, first seen in M1 Pro/Max, extends both the address space and filter + entry size to 42 bit. + +properties: + compatible: + enum: + - apple,t6000-sart + - apple,t8103-sart + + reg: + maxItems: 1 + + power-domains: + maxItems: 1 + +required: + - compatible + - reg + +additionalProperties: false + +examples: + - | + iommu@7bc50000 { + compatible = "apple,t8103-sart"; + reg = <0x7bc50000 0x4000>; + }; |