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author | Sascha Hauer <s.hauer@pengutronix.de> | 2014-06-17 22:16:07 +0200 |
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committer | Sascha Hauer <s.hauer@pengutronix.de> | 2014-06-19 09:41:51 +0200 |
commit | 9313920df6d3d55fbd03ce8ec1c0da9a10c29824 (patch) | |
tree | ef80d80abbaf46293b777ead52caddd9d5d97644 /dts/Bindings/iommu | |
parent | 83e875e1f45beffe399cff0ff6128e0fca9da168 (diff) | |
download | barebox-9313920df6d3d55fbd03ce8ec1c0da9a10c29824.tar.gz barebox-9313920df6d3d55fbd03ce8ec1c0da9a10c29824.tar.xz |
dts: update to v3.16-rc1
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Diffstat (limited to 'dts/Bindings/iommu')
-rw-r--r-- | dts/Bindings/iommu/samsung,sysmmu.txt | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/dts/Bindings/iommu/samsung,sysmmu.txt b/dts/Bindings/iommu/samsung,sysmmu.txt new file mode 100644 index 0000000000..6fa4c737af --- /dev/null +++ b/dts/Bindings/iommu/samsung,sysmmu.txt @@ -0,0 +1,70 @@ +Samsung Exynos IOMMU H/W, System MMU (System Memory Management Unit) + +Samsung's Exynos architecture contains System MMUs that enables scattered +physical memory chunks visible as a contiguous region to DMA-capable peripheral +devices like MFC, FIMC, FIMD, GScaler, FIMC-IS and so forth. + +System MMU is an IOMMU and supports identical translation table format to +ARMv7 translation tables with minimum set of page properties including access +permissions, shareability and security protection. In addition, System MMU has +another capabilities like L2 TLB or block-fetch buffers to minimize translation +latency. + +System MMUs are in many to one relation with peripheral devices, i.e. single +peripheral device might have multiple System MMUs (usually one for each bus +master), but one System MMU can handle transactions from only one peripheral +device. The relation between a System MMU and the peripheral device needs to be +defined in device node of the peripheral device. + +MFC in all Exynos SoCs and FIMD, M2M Scalers and G2D in Exynos5420 has 2 System +MMUs. +* MFC has one System MMU on its left and right bus. +* FIMD in Exynos5420 has one System MMU for window 0 and 4, the other system MMU + 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. + +Required properties: +- compatible: Should be "samsung,exynos-sysmmu" +- reg: A tuple of base address and size of System MMU registers. +- 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. + 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. +- samsung,power-domain: Required if the System MMU is needed to gate its power. + Please refer to the following document: + Documentation/devicetree/bindings/arm/exynos/power_domain.txt + +Examples: + gsc_0: gsc@13e00000 { + compatible = "samsung,exynos5-gsc"; + reg = <0x13e00000 0x1000>; + interrupts = <0 85 0>; + samsung,power-domain = <&pd_gsc>; + clocks = <&clock CLK_GSCL0>; + clock-names = "gscl"; + }; + + sysmmu_gsc0: sysmmu@13E80000 { + compatible = "samsung,exynos-sysmmu"; + reg = <0x13E80000 0x1000>; + interrupt-parent = <&combiner>; + interrupts = <2 0>; + clock-names = "sysmmu", "master"; + clocks = <&clock CLK_SMMU_GSCL0>, <&clock CLK_GSCL0>; + samsung,power-domain = <&pd_gsc>; + }; |