diff options
Diffstat (limited to 'Documentation/devicetree/bindings/iommu/mediatek,iommu.txt')
| -rw-r--r-- | Documentation/devicetree/bindings/iommu/mediatek,iommu.txt | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/Documentation/devicetree/bindings/iommu/mediatek,iommu.txt b/Documentation/devicetree/bindings/iommu/mediatek,iommu.txt index cd1b1cd7b5c4..53c20cae309f 100644 --- a/Documentation/devicetree/bindings/iommu/mediatek,iommu.txt +++ b/Documentation/devicetree/bindings/iommu/mediatek,iommu.txt @@ -1,7 +1,9 @@ * Mediatek IOMMU Architecture Implementation - Some Mediatek SOCs contain a Multimedia Memory Management Unit (M4U) which -uses the ARM Short-Descriptor translation table format for address translation. + Some Mediatek SOCs contain a Multimedia Memory Management Unit (M4U), and +this M4U have two generations of HW architecture. Generation one uses flat +pagetable, and only supports 4K size page mapping. Generation two uses the +ARM Short-Descriptor translation table format for address translation. About the M4U Hardware Block Diagram, please check below: @@ -36,7 +38,9 @@ in each larb. Take a example, There are many ports like MC, PP, VLD in the video decode local arbiter, all these ports are according to the video HW. Required properties: -- compatible : must be "mediatek,mt8173-m4u". +- compatible : must be one of the following string: + "mediatek,mt2701-m4u" for mt2701 which uses generation one m4u HW. + "mediatek,mt8173-m4u" for mt8173 which uses generation two m4u HW. - reg : m4u register base and size. - interrupts : the interrupt of m4u. - clocks : must contain one entry for each clock-names. @@ -46,7 +50,8 @@ Required properties: according to the local arbiter index, like larb0, larb1, larb2... - iommu-cells : must be 1. This is the mtk_m4u_id according to the HW. Specifies the mtk_m4u_id as defined in - dt-binding/memory/mt8173-larb-port.h. + dt-binding/memory/mt2701-larb-port.h for mt2701 and + dt-binding/memory/mt8173-larb-port.h for mt8173 Example: iommu: iommu@10205000 { |