On Fri, 14 Mar 2014 13:20:23 +0100, Tomasz Figa wrote: > Hi KyongHo, > > On 14.03.2014 06:06, Cho KyongHo wrote: > > This patch adds dts entries for the System MMU devices found on > > Exynos4 and Exynos5 SoC series and the System MMU binding > > documentation. > > > > CC: Rob Herring <robherring2@xxxxxxxxx> > > CC: Sylwester Nawrocki <s.nawrocki@xxxxxxxxxxx> > > Signed-off-by: Cho KyongHo <pullip.cho@xxxxxxxxxxx> > > --- > > .../bindings/iommu/samsung,exynos4210-sysmmu.txt | 86 +++++++ > > arch/arm/boot/dts/exynos4.dtsi | 107 ++++++++ > > arch/arm/boot/dts/exynos4210.dtsi | 23 +- > > arch/arm/boot/dts/exynos4x12.dtsi | 77 +++++- > > arch/arm/boot/dts/exynos5250.dtsi | 266 +++++++++++++++++++- > > arch/arm/boot/dts/exynos5420.dtsi | 205 ++++++++++++++- > > 6 files changed, 758 insertions(+), 6 deletions(-) > > create mode 100644 Documentation/devicetree/bindings/iommu/samsung,exynos4210-sysmmu.txt > > > > diff --git a/Documentation/devicetree/bindings/iommu/samsung,exynos4210-sysmmu.txt b/Documentation/devicetree/bindings/iommu/samsung,exynos4210-sysmmu.txt > > new file mode 100644 > > index 0000000..e4417bb > > --- /dev/null > > +++ b/Documentation/devicetree/bindings/iommu/samsung,exynos4210-sysmmu.txt > > @@ -0,0 +1,86 @@ > > +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. > > + > > +Required properties: > > +- compatible: Should be one of: > > + "samsung,sysmmu-v1" > > + "samsung,sysmmu-v2" > > + "samsung,sysmmu-v3.1" > > + "samsung,sysmmu-v3.2" > > + "samsung,sysmmu-v3.3" > > + > > +- 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. > > + Please refer to the following documents: > > + Documentation/devicetree/bindings/clock/clock-bindings.txt > > + Documentation/devicetree/bindings/clock/exynos4-clock.txt > > + Documentation/devicetree/bindings/clock/exynos5250-clock.txt > > + Documentation/devicetree/bindings/clock/exynos5420-clock.txt > > + Optional "master" if the clock to the System MMU is gated by > > + another gate clock other than "sysmmu". The System MMU driver > > + sets "master" the parent of "sysmmu". > > + Exynos4 SoCs, there needs no "master" clockj. > > + Exynos5 SoCs, some System MMUs must have "master" clocks. > > +- clocks: Required if the System MMU is needed to gate its clock. > > + Please refer to the documents listed above. > > +- 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 > > +- mmu-masters: A phandle to device nodes representing the master for which > > + the System MMU can provide a translation. Any additional values > > + after the phandle will be ignored because a System MMU never > > + have two or more masters. "#stream-id-cells" specified in the > > + master's node will be also ignored. > > + If more than one phandle is specified, only the first phandle > > + will be treated. > > + > > +Examples: > > + gsc_0: gsc@13e00000 { > > + compatible = "samsung,exynos5-gsc"; > > + reg = <0x13e00000 0x1000>; > > + interrupts = <0 85 0>; > > + samsung,power-domain = <&pd_gsc>; > > + clocks = <&clock 256>; > > + clock-names = "gscl"; > > + }; > > + > > + sysmmu_gsc0: sysmmu@13E80000 { > > + compatible = "samsung,exynos4210-sysmmu"; > > + reg = <0x13E80000 0x1000>; > > + interrupt-parent = <&combiner>; > > + interrupts = <2 0>; > > + clock-names = "sysmmu", "master"; > > + clocks = <&clock 262>, <&clock 256>; > > + samsung,power-domain = <&pd_gsc>; > > + mmu-masters = <&gsc_0>; > > + }; > > Binding documentation should be added in separate patch in front of the > series relying on such binding or with the patch adding binding > implementation to the driver, so DT maintainers can review the binding > and related code easily. > > Changes to dts(i) files should be posted in a separate patch, preferably > at the end of the series, when any prerequisites are already available. > Thank you for the advice. Should the patches related to the change in DT be shown in the following order? "documentation -> source code change -> DT description" KyongHo -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html