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+SMI (Smart Multimedia Interface) Common
+
+The hardware block diagram please check bindings/iommu/mediatek,iommu.txt
+
+Mediatek SMI have two generations of HW architecture, mt8173 uses the second
+generation of SMI HW while mt2701 uses the first generation HW of SMI.
+
+There's slight differences between the two SMI, for generation 2, the
+register which control the iommu port is at each larb's register base. But
+for generation 1, the register is at smi ao base(smi always on register
+base). Besides that, the smi async clock should be prepared and enabled for
+SMI generation 1 to transform the smi clock into emi clock domain, but that is
+not needed for SMI generation 2.
+
+Required properties:
+- compatible : must be one of :
+	"mediatek,mt2701-smi-common"
+	"mediatek,mt8173-smi-common"
+- reg : the register and size of the SMI block.
+- power-domains : a phandle to the power domain of this local arbiter.
+- clocks : Must contain an entry for each entry in clock-names.
+- clock-names : must contain 3 entries for generation 1 smi HW and 2 entries
+  for generation 2 smi HW as follows:
+  - "apb" : Advanced Peripheral Bus clock, It's the clock for setting
+	    the register.
+  - "smi" : It's the clock for transfer data and command.
+	    They may be the same if both source clocks are the same.
+  - "async" : asynchronous clock, it help transform the smi clock into the emi
+	      clock domain, this clock is only needed by generation 1 smi HW.
+
+Example:
+	smi_common: smi@14022000 {
+		compatible = "mediatek,mt8173-smi-common";
+		reg = <0 0x14022000 0 0x1000>;
+		power-domains = <&scpsys MT8173_POWER_DOMAIN_MM>;
+		clocks = <&mmsys CLK_MM_SMI_COMMON>,
+			 <&mmsys CLK_MM_SMI_COMMON>;
+		clock-names = "apb", "smi";
+	};