diff --git a/arch/arm64/boot/dts/renesas/r8a774b1.dtsi b/arch/arm64/boot/dts/renesas/r8a774b1.dtsi
index ac3c411d321a..e6c8cca6b679 100644
--- a/arch/arm64/boot/dts/renesas/r8a774b1.dtsi
+++ b/arch/arm64/boot/dts/renesas/r8a774b1.dtsi
@@ -237,8 +237,91 @@
 		};
 
 		hscif0: serial@e6540000 {
+			compatible = "renesas,hscif-r8a774b1",
+				     "renesas,rcar-gen3-hscif",
+				     "renesas,hscif";
 			reg = <0 0xe6540000 0 0x60>;
-			/* placeholder */
+			interrupts = <GIC_SPI 154 IRQ_TYPE_LEVEL_HIGH>;
+			clocks = <&cpg CPG_MOD 520>,
+				 <&cpg CPG_CORE R8A774B1_CLK_S3D1>,
+				 <&scif_clk>;
+			clock-names = "fck", "brg_int", "scif_clk";
+			dmas = <&dmac1 0x31>, <&dmac1 0x30>,
+			       <&dmac2 0x31>, <&dmac2 0x30>;
+			dma-names = "tx", "rx", "tx", "rx";
+			power-domains = <&sysc R8A774B1_PD_ALWAYS_ON>;
+			resets = <&cpg 520>;
+			status = "disabled";
+		};
+
+		hscif1: serial@e6550000 {
+			compatible = "renesas,hscif-r8a774b1",
+				     "renesas,rcar-gen3-hscif",
+				     "renesas,hscif";
+			reg = <0 0xe6550000 0 0x60>;
+			interrupts = <GIC_SPI 155 IRQ_TYPE_LEVEL_HIGH>;
+			clocks = <&cpg CPG_MOD 519>,
+				 <&cpg CPG_CORE R8A774B1_CLK_S3D1>,
+				 <&scif_clk>;
+			clock-names = "fck", "brg_int", "scif_clk";
+			dmas = <&dmac1 0x33>, <&dmac1 0x32>,
+			       <&dmac2 0x33>, <&dmac2 0x32>;
+			dma-names = "tx", "rx", "tx", "rx";
+			power-domains = <&sysc R8A774B1_PD_ALWAYS_ON>;
+			resets = <&cpg 519>;
+			status = "disabled";
+		};
+
+		hscif2: serial@e6560000 {
+			compatible = "renesas,hscif-r8a774b1",
+				     "renesas,rcar-gen3-hscif",
+				     "renesas,hscif";
+			reg = <0 0xe6560000 0 0x60>;
+			interrupts = <GIC_SPI 144 IRQ_TYPE_LEVEL_HIGH>;
+			clocks = <&cpg CPG_MOD 518>,
+				 <&cpg CPG_CORE R8A774B1_CLK_S3D1>,
+				 <&scif_clk>;
+			clock-names = "fck", "brg_int", "scif_clk";
+			dmas = <&dmac1 0x35>, <&dmac1 0x34>,
+			       <&dmac2 0x35>, <&dmac2 0x34>;
+			dma-names = "tx", "rx", "tx", "rx";
+			power-domains = <&sysc R8A774B1_PD_ALWAYS_ON>;
+			resets = <&cpg 518>;
+			status = "disabled";
+		};
+
+		hscif3: serial@e66a0000 {
+			compatible = "renesas,hscif-r8a774b1",
+				     "renesas,rcar-gen3-hscif",
+				     "renesas,hscif";
+			reg = <0 0xe66a0000 0 0x60>;
+			interrupts = <GIC_SPI 145 IRQ_TYPE_LEVEL_HIGH>;
+			clocks = <&cpg CPG_MOD 517>,
+				 <&cpg CPG_CORE R8A774B1_CLK_S3D1>,
+				 <&scif_clk>;
+			clock-names = "fck", "brg_int", "scif_clk";
+			dmas = <&dmac0 0x37>, <&dmac0 0x36>;
+			dma-names = "tx", "rx";
+			power-domains = <&sysc R8A774B1_PD_ALWAYS_ON>;
+			resets = <&cpg 517>;
+			status = "disabled";
+		};
+
+		hscif4: serial@e66b0000 {
+			compatible = "renesas,hscif-r8a774b1",
+				     "renesas,rcar-gen3-hscif",
+				     "renesas,hscif";
+			reg = <0 0xe66b0000 0 0x60>;
+			interrupts = <GIC_SPI 146 IRQ_TYPE_LEVEL_HIGH>;
+			clocks = <&cpg CPG_MOD 516>,
+				 <&cpg CPG_CORE R8A774B1_CLK_S3D1>,
+				 <&scif_clk>;
+			clock-names = "fck", "brg_int", "scif_clk";
+			dmas = <&dmac0 0x39>, <&dmac0 0x38>;
+			dma-names = "tx", "rx";
+			power-domains = <&sysc R8A774B1_PD_ALWAYS_ON>;
+			resets = <&cpg 516>;
+			status = "disabled";
 		};
 
 		hsusb: usb@e6590000 {
@@ -374,20 +457,106 @@
 			/* placeholder */
 		};
 
+		scif0: serial@e6e60000 {
+			compatible = "renesas,scif-r8a774b1",
+				     "renesas,rcar-gen3-scif", "renesas,scif";
+			reg = <0 0xe6e60000 0 0x40>;
+			interrupts = <GIC_SPI 152 IRQ_TYPE_LEVEL_HIGH>;
+			clocks = <&cpg CPG_MOD 207>,
+				 <&cpg CPG_CORE R8A774B1_CLK_S3D1>,
+				 <&scif_clk>;
+			clock-names = "fck", "brg_int", "scif_clk";
+			dmas = <&dmac1 0x51>, <&dmac1 0x50>,
+			       <&dmac2 0x51>, <&dmac2 0x50>;
+			dma-names = "tx", "rx", "tx", "rx";
+			power-domains = <&sysc R8A774B1_PD_ALWAYS_ON>;
+			resets = <&cpg 207>;
+			status = "disabled";
+		};
+
+		scif1: serial@e6e68000 {
+			compatible = "renesas,scif-r8a774b1",
+				     "renesas,rcar-gen3-scif", "renesas,scif";
+			reg = <0 0xe6e68000 0 0x40>;
+			interrupts = <GIC_SPI 153 IRQ_TYPE_LEVEL_HIGH>;
+			clocks = <&cpg CPG_MOD 206>,
+				 <&cpg CPG_CORE R8A774B1_CLK_S3D1>,
+				 <&scif_clk>;
+			clock-names = "fck", "brg_int", "scif_clk";
+			dmas = <&dmac1 0x53>, <&dmac1 0x52>,
+			       <&dmac2 0x53>, <&dmac2 0x52>;
+			dma-names = "tx", "rx", "tx", "rx";
+			power-domains = <&sysc R8A774B1_PD_ALWAYS_ON>;
+			resets = <&cpg 206>;
+			status = "disabled";
+		};
+
 		scif2: serial@e6e88000 {
 			compatible = "renesas,scif-r8a774b1",
 				     "renesas,rcar-gen3-scif", "renesas,scif";
-			reg = <0 0xe6e88000 0 64>;
+			reg = <0 0xe6e88000 0 0x40>;
 			interrupts = <GIC_SPI 164 IRQ_TYPE_LEVEL_HIGH>;
 			clocks = <&cpg CPG_MOD 310>,
 				 <&cpg CPG_CORE R8A774B1_CLK_S3D1>,
 				 <&scif_clk>;
 			clock-names = "fck", "brg_int", "scif_clk";
+			dmas = <&dmac1 0x13>, <&dmac1 0x12>,
+			       <&dmac2 0x13>, <&dmac2 0x12>;
+			dma-names = "tx", "rx", "tx", "rx";
 			power-domains = <&sysc R8A774B1_PD_ALWAYS_ON>;
 			resets = <&cpg 310>;
 			status = "disabled";
 		};
 
+		scif3: serial@e6c50000 {
+			compatible = "renesas,scif-r8a774b1",
+				     "renesas,rcar-gen3-scif", "renesas,scif";
+			reg = <0 0xe6c50000 0 0x40>;
+			interrupts = <GIC_SPI 23 IRQ_TYPE_LEVEL_HIGH>;
+			clocks = <&cpg CPG_MOD 204>,
+				 <&cpg CPG_CORE R8A774B1_CLK_S3D1>,
+				 <&scif_clk>;
+			clock-names = "fck", "brg_int", "scif_clk";
+			dmas = <&dmac0 0x57>, <&dmac0 0x56>;
+			dma-names = "tx", "rx";
+			power-domains = <&sysc R8A774B1_PD_ALWAYS_ON>;
+			resets = <&cpg 204>;
+			status = "disabled";
+		};
+
+		scif4: serial@e6c40000 {
+			compatible = "renesas,scif-r8a774b1",
+				     "renesas,rcar-gen3-scif", "renesas,scif";
+			reg = <0 0xe6c40000 0 0x40>;
+			interrupts = <GIC_SPI 16 IRQ_TYPE_LEVEL_HIGH>;
+			clocks = <&cpg CPG_MOD 203>,
+				 <&cpg CPG_CORE R8A774B1_CLK_S3D1>,
+				 <&scif_clk>;
+			clock-names = "fck", "brg_int", "scif_clk";
+			dmas = <&dmac0 0x59>, <&dmac0 0x58>;
+			dma-names = "tx", "rx";
+			power-domains = <&sysc R8A774B1_PD_ALWAYS_ON>;
+			resets = <&cpg 203>;
+			status = "disabled";
+		};
+
+		scif5: serial@e6f30000 {
+			compatible = "renesas,scif-r8a774b1",
+				     "renesas,rcar-gen3-scif", "renesas,scif";
+			reg = <0 0xe6f30000 0 0x40>;
+			interrupts = <GIC_SPI 17 IRQ_TYPE_LEVEL_HIGH>;
+			clocks = <&cpg CPG_MOD 202>,
+				 <&cpg CPG_CORE R8A774B1_CLK_S3D1>,
+				 <&scif_clk>;
+			clock-names = "fck", "brg_int", "scif_clk";
+			dmas = <&dmac1 0x5b>, <&dmac1 0x5a>,
+			       <&dmac2 0x5b>, <&dmac2 0x5a>;
+			dma-names = "tx", "rx", "tx", "rx";
+			power-domains = <&sysc R8A774B1_PD_ALWAYS_ON>;
+			resets = <&cpg 202>;
+			status = "disabled";
+		};
+
 		rcar_sound: sound@ec500000 {
 			reg = <0 0xec500000 0 0x1000>, /* SCU */
 			      <0 0xec5a0000 0 0x100>,  /* ADG */