diff options
Diffstat (limited to 'Documentation/devicetree/bindings/iommu/samsung,sysmmu.txt')
| -rw-r--r-- | Documentation/devicetree/bindings/iommu/samsung,sysmmu.txt | 22 |
1 files changed, 10 insertions, 12 deletions
diff --git a/Documentation/devicetree/bindings/iommu/samsung,sysmmu.txt b/Documentation/devicetree/bindings/iommu/samsung,sysmmu.txt index bc620fe32a70..85f068805dd8 100644 --- a/Documentation/devicetree/bindings/iommu/samsung,sysmmu.txt +++ b/Documentation/devicetree/bindings/iommu/samsung,sysmmu.txt @@ -23,28 +23,24 @@ MMUs. for window 1, 2 and 3. * M2M Scalers and G2D in Exynos5420 has one System MMU on the read channel and the other System MMU on the write channel. -The drivers must consider how to handle those System MMUs. One of the idea is -to implement child devices or sub-devices which are the client devices of the -System MMU. -Note: -The current DT binding for the Exynos System MMU is incomplete. -The following properties can be removed or changed, if found incompatible with -the "Generic IOMMU Binding" support for attaching devices to the IOMMU. +For information on assigning System MMU controller to its peripheral devices, +see generic IOMMU bindings. Required properties: - compatible: Should be "samsung,exynos-sysmmu" - reg: A tuple of base address and size of System MMU registers. +- #iommu-cells: Should be <0>. - interrupt-parent: The phandle of the interrupt controller of System MMU - interrupts: An interrupt specifier for interrupt signal of System MMU, according to the format defined by a particular interrupt controller. -- clock-names: Should be "sysmmu" if the System MMU is needed to gate its clock. +- clock-names: Should be "sysmmu" or a pair of "aclk" and "pclk" to gate + SYSMMU core clocks. Optional "master" if the clock to the System MMU is gated by - another gate clock other than "sysmmu". - Exynos4 SoCs, there needs no "master" clock. - Exynos5 SoCs, some System MMUs must have "master" clocks. -- clocks: Required if the System MMU is needed to gate its clock. + another gate clock other core (usually main gate clock + of peripheral device this SYSMMU belongs to). +- clocks: Phandles for respective clocks described by clock-names. - power-domains: Required if the System MMU is needed to gate its power. Please refer to the following document: Documentation/devicetree/bindings/power/pd-samsung.txt @@ -57,6 +53,7 @@ Examples: power-domains = <&pd_gsc>; clocks = <&clock CLK_GSCL0>; clock-names = "gscl"; + iommus = <&sysmmu_gsc0>; }; sysmmu_gsc0: sysmmu@13E80000 { @@ -67,4 +64,5 @@ Examples: clock-names = "sysmmu", "master"; clocks = <&clock CLK_SMMU_GSCL0>, <&clock CLK_GSCL0>; power-domains = <&pd_gsc>; + #iommu-cells = <0>; }; |