diff options
author | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 12:17:53 -0700 |
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committer | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 15:44:42 -0700 |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/Documentation/devicetree/bindings/iommu/samsung,sysmmu.txt | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/Documentation/devicetree/bindings/iommu/samsung,sysmmu.txt')
-rw-r--r-- | kernel/Documentation/devicetree/bindings/iommu/samsung,sysmmu.txt | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/kernel/Documentation/devicetree/bindings/iommu/samsung,sysmmu.txt b/kernel/Documentation/devicetree/bindings/iommu/samsung,sysmmu.txt new file mode 100644 index 000000000..729543c47 --- /dev/null +++ b/kernel/Documentation/devicetree/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. +- power-domains: 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>; + power-domains = <&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>; + power-domains = <&pd_gsc>; + }; |