Messages in this thread | | | Subject | Re: [Patch v15 4/5] dt-bindings: arm-smmu: Add bindings for qcom,smmu-v2 | From | Vivek Gautam <> | Date | Wed, 29 Aug 2018 14:05:10 +0530 |
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Hi Rob,
On 8/29/2018 2:04 AM, Rob Herring wrote: > On Mon, Aug 27, 2018 at 04:25:50PM +0530, Vivek Gautam wrote: >> Add bindings doc for Qcom's smmu-v2 implementation. >> >> Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org> >> Reviewed-by: Tomasz Figa <tfiga@chromium.org> >> Tested-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> >> --- >> >> Changes since v14: >> - This is a new patch added in v15 after noticing the new >> checkpatch warning for separate dt-bindings doc. >> - This patch also addresses comments given by Rob and Robin to add >> a list of valid values of '<soc>' in "qcom,<soc>-smmu-v2" >> compatible string. >> >> .../devicetree/bindings/iommu/arm,smmu.txt | 47 ++++++++++++++++++++++ >> 1 file changed, 47 insertions(+) >> >> diff --git a/Documentation/devicetree/bindings/iommu/arm,smmu.txt b/Documentation/devicetree/bindings/iommu/arm,smmu.txt >> index 8a6ffce12af5..52198a539606 100644 >> --- a/Documentation/devicetree/bindings/iommu/arm,smmu.txt >> +++ b/Documentation/devicetree/bindings/iommu/arm,smmu.txt >> @@ -17,10 +17,24 @@ conditions. >> "arm,mmu-401" >> "arm,mmu-500" >> "cavium,smmu-v2" >> + "qcom,<soc>-smmu-v2", "qcom,smmu-v2" > The v2 in the compatible string is kind of redundant unless the SoC has > other SMMU types.
sdm845 has smmu-v2, and smmu-500 [1].
>> >> depending on the particular implementation and/or the >> version of the architecture implemented. >> >> + A number of Qcom SoCs use qcom,smmu-v2 version of the IP. >> + "qcom,<soc>-smmu-v2" represents a soc specific compatible >> + string that should be present along with the "qcom,smmu-v2" >> + to facilitate SoC specific clocks/power connections and to >> + address specific bug fixes. >> + '<soc>' string in "qcom,<soc>-smmu-v2" should be one of the >> + following: >> + msm8996 - for msm8996 Qcom SoC. >> + sdm845 - for sdm845 Qcom Soc. > Rather than all this prose, it would be simpler to just add 2 lines with > the full compatibles rather than <soc>. The <soc> thing is not going to > work when/if we move bindings to json-schema also.
then we keep adding "qcom,msm8996-smmu-v2", "qcom,smmu-v2" "qcom,msm8998-smmu-v2", "qcom,smmu-v2" "qcom,sdm845-smmu-v2", "qcom,smmu-v2", and from [1] "qcom,sdm845-smmu-500", "arm,mmu-500", etc. for each SoCs?
> >> + >> + An example string would be - >> + "qcom,msm8996-smmu-v2", "qcom,smmu-v2". >> + >> - reg : Base address and size of the SMMU. >> >> - #global-interrupts : The number of global interrupts exposed by the >> @@ -71,6 +85,22 @@ conditions. >> or using stream matching with #iommu-cells = <2>, and >> may be ignored if present in such cases. >> >> +- clock-names: List of the names of clocks input to the device. The >> + required list depends on particular implementation and >> + is as follows: >> + - for "qcom,smmu-v2": >> + - "bus": clock required for downstream bus access and >> + for the smmu ptw, >> + - "iface": clock required to access smmu's registers >> + through the TCU's programming interface. >> + - unspecified for other implementations. >> + >> +- clocks: Specifiers for all clocks listed in the clock-names property, >> + as per generic clock bindings. >> + >> +- power-domains: Specifiers for power domains required to be powered on for >> + the SMMU to operate, as per generic power domain bindings. >> + >> ** Deprecated properties: >> >> - mmu-masters (deprecated in favour of the generic "iommus" binding) : >> @@ -137,3 +167,20 @@ conditions. >> iommu-map = <0 &smmu3 0 0x400>; >> ... >> }; >> + >> + /* Qcom's arm,smmu-v2 implementation */ >> + smmu4: iommu { > Needs a unit-address.
I went in symmetry with another example in this file for 'smmu1'. I will add the address here. And if you would like, I can squash a change for 'smmu1' too in this patch, although that will be trivial.
[1] https://patchwork.kernel.org/patch/10565291/
Best regards Vivek
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