arm64: dts: renesas: r8a779g0: Add CAN-FD node

Add device nodes for the CAN-FD interface and the related external CAN
clock on the Renesas R-Car V4H (R8A779G0) SoC.

Based on a patch in the BSP by Kazuya Mizuguch.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/6c55d0995089917216ee261a8b8cbb980c7b5304.1674500205.git.geert+renesas@glider.be

arch/arm64/boot/dts/renesas/r8a779g0.dtsi

@@ -14,6 +14,13 @@ / {
 	#address-cells = <2>;
 	#size-cells = <2>;
 
+	/* External CAN clock - to be overridden by boards that provide it */
+	can_clk: can {
+		compatible = "fixed-clock";
+		#clock-cells = <0>;
+		clock-frequency = <0>;
+	};
+
 	cluster0_opp: opp-table-0 {
 		compatible = "operating-points-v2";
 		opp-shared;
@@ -682,6 +689,56 @@ hscif3: serial@e66a0000 {
 			status = "disabled";
 		};
 
+		canfd: can@e6660000 {
+			compatible = "renesas,r8a779g0-canfd",
+				     "renesas,rcar-gen4-canfd";
+			reg = <0 0xe6660000 0 0x8500>;
+			interrupts = <GIC_SPI 412 IRQ_TYPE_LEVEL_HIGH>,
+				     <GIC_SPI 413 IRQ_TYPE_LEVEL_HIGH>;
+			interrupt-names = "ch_int", "g_int";
+			clocks = <&cpg CPG_MOD 328>,
+				 <&cpg CPG_CORE R8A779G0_CLK_CANFD>,
+				 <&can_clk>;
+			clock-names = "fck", "canfd", "can_clk";
+			assigned-clocks = <&cpg CPG_CORE R8A779G0_CLK_CANFD>;
+			assigned-clock-rates = <80000000>;
+			power-domains = <&sysc R8A779G0_PD_ALWAYS_ON>;
+			resets = <&cpg 328>;
+			status = "disabled";
+
+			channel0 {
+				status = "disabled";
+			};
+
+			channel1 {
+				status = "disabled";
+			};
+
+			channel2 {
+				status = "disabled";
+			};
+
+			channel3 {
+				status = "disabled";
+			};
+
+			channel4 {
+				status = "disabled";
+			};
+
+			channel5 {
+				status = "disabled";
+			};
+
+			channel6 {
+				status = "disabled";
+			};
+
+			channel7 {
+				status = "disabled";
+			};
+		};
+
 		avb0: ethernet@e6800000 {
 			compatible = "renesas,etheravb-r8a779g0",
 				     "renesas,etheravb-rcar-gen4";