On Wed, Aug 29, 2018 at 2:05 PM Vivek Gautam
<vivek.gautam@xxxxxxxxxxxxxx> wrote:
>
> 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@xxxxxxxxxxxxxx>
> >> Reviewed-by: Tomasz Figa <tfiga@xxxxxxxxxxxx>
> >> Tested-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
> >> ---
> >>
> >> 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?
How about following diff on top of this patch?
diff --git a/Documentation/devicetree/bindings/iommu/arm,smmu.txt
b/Documentation/devicetree/bindings/iommu/arm,smmu.txt
index 52198a539606..5e6c04876533 100644
--- a/Documentation/devicetree/bindings/iommu/arm,smmu.txt
+++ b/Documentation/devicetree/bindings/iommu/arm,smmu.txt
@@ -17,23 +17,18 @@ conditions.
"arm,mmu-401"
"arm,mmu-500"
"cavium,smmu-v2"
- "qcom,<soc>-smmu-v2", "qcom,smmu-v2"
+ "qcom,smmu-v2"
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.
-
- An example string would be -
- "qcom,msm8996-smmu-v2", "qcom,smmu-v2".
+ Qcom SoCs using qcom,smmu-v2 must have soc specific
+ compatible string attached to "qcom,smmu-v2" to take care
+ of SoC specific clocks/power connections and to address
+ specific bug fixes.
+ Precisely, it should be one of the following:
+ "qcom,msm8996-smmu-v2", "qcom,smmu-v2",
+ "qcom,sdm845-smmu-v2", "qcom,smmu-v2".
Thanks!
Best regards
Vivek
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