| Message ID | 20200702093721.6063-1-miles.chen@mediatek.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/4] dt-bindings: mediatek: add mediatek,infracfg phandle | expand |
On Thu, Jul 02, 2020 at 05:37:17PM +0800, Miles Chen wrote: > Add a description for mediatek,infracfg. We can check if 4GB mode > is enable by reading it instead of checking the unexported > symbol "max_pfn". > > This is a step towards building mtk_iommu as a kernel module. You determined this before without DT, so it is an OS problem and shouldn't need a DT update. I'd assume there's only one instance of the node mediatek,infracfg points to, so just search for it if you want to get the info from DT. > > Cc: Yong Wu <yong.wu@mediatek.com> > Signed-off-by: Miles Chen <miles.chen@mediatek.com> > --- > Documentation/devicetree/bindings/iommu/mediatek,iommu.txt | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/Documentation/devicetree/bindings/iommu/mediatek,iommu.txt b/Documentation/devicetree/bindings/iommu/mediatek,iommu.txt > index ce59a505f5a4..a7881deabcca 100644 > --- a/Documentation/devicetree/bindings/iommu/mediatek,iommu.txt > +++ b/Documentation/devicetree/bindings/iommu/mediatek,iommu.txt > @@ -74,6 +74,8 @@ Required properties: > - mediatek,larbs : List of phandle to the local arbiters in the current Socs. > Refer to bindings/memory-controllers/mediatek,smi-larb.txt. It must sort > according to the local arbiter index, like larb0, larb1, larb2... > +- mediatek,infracfg: a phandle to infracfg. It is used to confirm if 4GB mode is set. > + It is an optional property, add it when the SoC have 4g mode. > - iommu-cells : must be 1. This is the mtk_m4u_id according to the HW. > Specifies the mtk_m4u_id as defined in > dt-binding/memory/mt2701-larb-port.h for mt2701, mt7623 > -- > 2.18.0
On Wed, 2020-07-15 at 14:51 -0600, Rob Herring wrote: > On Thu, Jul 02, 2020 at 05:37:17PM +0800, Miles Chen wrote: > > Add a description for mediatek,infracfg. We can check if 4GB mode > > is enable by reading it instead of checking the unexported > > symbol "max_pfn". > > > > This is a step towards building mtk_iommu as a kernel module. > > You determined this before without DT, so it is an OS problem and > shouldn't need a DT update. Thanks for your comment. The old way (using max_pfn) do determine this is risky because the max_pfn may lower than (GB if reserved memory regions occupy memory higher than 4GB. So, the better way to do this is by reading register from H/W. > > I'd assume there's only one instance of the node mediatek,infracfg > points to, so just search for it if you want to get the info from DT. > I can do syscon_regmap_lookup_by_compatible() to search for it. However, the compatibles are different in mt2712e.dtsi and mt8173.dtsi. so I have to search "mediatek,mt2712-infracfg" and "mediatek,mt8173-infracfg" respectively. Using mediatek,infracfg phandle can make the code easier to read. Is it possible to reconsider the phandle approach, please? arch/arm64/boot/dts/mediatek/mt2712e.dtsi:253: infracfg: syscon@10001000 { compatible = "mediatek,mt2712-infracfg", "syscon"; arch/arm64/boot/dts/mediatek/mt8173.dtsi:363: infracfg: power-controller@10001000 { compatible = "mediatek,mt8173-infracfg", "syscon"; > > > > > Cc: Yong Wu <yong.wu@mediatek.com> > > Signed-off-by: Miles Chen <miles.chen@mediatek.com> > > --- > > Documentation/devicetree/bindings/iommu/mediatek,iommu.txt | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/Documentation/devicetree/bindings/iommu/mediatek,iommu.txt b/Documentation/devicetree/bindings/iommu/mediatek,iommu.txt > > index ce59a505f5a4..a7881deabcca 100644 > > --- a/Documentation/devicetree/bindings/iommu/mediatek,iommu.txt > > +++ b/Documentation/devicetree/bindings/iommu/mediatek,iommu.txt > > @@ -74,6 +74,8 @@ Required properties: > > - mediatek,larbs : List of phandle to the local arbiters in the current Socs. > > Refer to bindings/memory-controllers/mediatek,smi-larb.txt. It must sort > > according to the local arbiter index, like larb0, larb1, larb2... > > +- mediatek,infracfg: a phandle to infracfg. It is used to confirm if 4GB mode is set. > > + It is an optional property, add it when the SoC have 4g mode. > > - iommu-cells : must be 1. This is the mtk_m4u_id according to the HW. > > Specifies the mtk_m4u_id as defined in > > dt-binding/memory/mt2701-larb-port.h for mt2701, mt7623 > > -- > > 2.18.0
diff --git a/Documentation/devicetree/bindings/iommu/mediatek,iommu.txt b/Documentation/devicetree/bindings/iommu/mediatek,iommu.txt index ce59a505f5a4..a7881deabcca 100644 --- a/Documentation/devicetree/bindings/iommu/mediatek,iommu.txt +++ b/Documentation/devicetree/bindings/iommu/mediatek,iommu.txt @@ -74,6 +74,8 @@ Required properties: - mediatek,larbs : List of phandle to the local arbiters in the current Socs. Refer to bindings/memory-controllers/mediatek,smi-larb.txt. It must sort according to the local arbiter index, like larb0, larb1, larb2... +- mediatek,infracfg: a phandle to infracfg. It is used to confirm if 4GB mode is set. + It is an optional property, add it when the SoC have 4g mode. - iommu-cells : must be 1. This is the mtk_m4u_id according to the HW. Specifies the mtk_m4u_id as defined in dt-binding/memory/mt2701-larb-port.h for mt2701, mt7623
Add a description for mediatek,infracfg. We can check if 4GB mode is enable by reading it instead of checking the unexported symbol "max_pfn". This is a step towards building mtk_iommu as a kernel module. Cc: Yong Wu <yong.wu@mediatek.com> Signed-off-by: Miles Chen <miles.chen@mediatek.com> --- Documentation/devicetree/bindings/iommu/mediatek,iommu.txt | 2 ++ 1 file changed, 2 insertions(+)