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authorMarek Szyprowski <m.szyprowski@samsung.com>2016-02-18 17:12:57 +0300
committerJoerg Roedel <jroedel@suse.de>2016-02-25 17:32:10 +0300
commite6802707fbfacfa0a4668d176dc2f0f9dd6637be (patch)
treedac62a64310f8fbfc8b2a62bf86a472a03604c3b
parent850d313e2ed52d19b781e38536fc44ba0b58c434 (diff)
downloadlinux-e6802707fbfacfa0a4668d176dc2f0f9dd6637be.tar.xz
iommu/exynos: Update device tree documentation
Exynos SYSMMU bindings documentation was merged before generic IOMMU binding have been introduced. This patch updates documentation to match current state. Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>
-rw-r--r--Documentation/devicetree/bindings/iommu/samsung,sysmmu.txt19
1 files changed, 8 insertions, 11 deletions
diff --git a/Documentation/devicetree/bindings/iommu/samsung,sysmmu.txt b/Documentation/devicetree/bindings/iommu/samsung,sysmmu.txt
index bc620fe32a70..f61ca25ca136 100644
--- a/Documentation/devicetree/bindings/iommu/samsung,sysmmu.txt
+++ b/Documentation/devicetree/bindings/iommu/samsung,sysmmu.txt
@@ -23,28 +23,23 @@ 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.
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 than "sysmmu" (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 +52,7 @@ Examples:
power-domains = <&pd_gsc>;
clocks = <&clock CLK_GSCL0>;
clock-names = "gscl";
+ iommus = <&sysmmu_gsc0>;
};
sysmmu_gsc0: sysmmu@13E80000 {
@@ -67,4 +63,5 @@ Examples:
clock-names = "sysmmu", "master";
clocks = <&clock CLK_SMMU_GSCL0>, <&clock CLK_GSCL0>;
power-domains = <&pd_gsc>;
+ #iommu-cells = <0>;
};