ARM: dts: sun7i: Add A20 SRAM and SRAM controller

The A20 has a few SRAM that can be mapped either to a device or to the CPU,
with the mapping being controlled by a SRAM controller.

Add the SRAM controller, the SRAM that it drives and the section that can
be used by the various devices.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>

arch/arm/boot/dts/sun7i-a20.dtsi

@@ -534,6 +534,42 @@ soc@01c00000 {
 		#size-cells = <1>;
 		ranges;
 
+		sram-controller@01c00000 {
+			compatible = "allwinner,sun4i-a10-sram-controller";
+			reg = <0x01c00000 0x30>;
+			#address-cells = <1>;
+			#size-cells = <1>;
+			ranges;
+
+			sram_a: sram@00000000 {
+				compatible = "mmio-sram";
+				reg = <0x00000000 0xc000>;
+				#address-cells = <1>;
+				#size-cells = <1>;
+				ranges = <0 0x00000000 0xc000>;
+
+				emac_sram: sram-section@8000 {
+					compatible = "allwinner,sun4i-a10-sram-a3-a4";
+					reg = <0x8000 0x4000>;
+					status = "disabled";
+				};
+			};
+
+			sram_d: sram@00010000 {
+				compatible = "mmio-sram";
+				reg = <0x00010000 0x1000>;
+				#address-cells = <1>;
+				#size-cells = <1>;
+				ranges = <0 0x00010000 0x1000>;
+
+				otg_sram: sram-section@0000 {
+					compatible = "allwinner,sun4i-a10-sram-d";
+					reg = <0x0000 0x1000>;
+					status = "disabled";
+				};
+			};
+		};
+
 		nmi_intc: interrupt-controller@01c00030 {
 			compatible = "allwinner,sun7i-a20-sc-nmi";
 			interrupt-controller;
@@ -583,6 +619,7 @@ emac: ethernet@01c0b000 {
 			reg = <0x01c0b000 0x1000>;
 			interrupts = <GIC_SPI 55 IRQ_TYPE_LEVEL_HIGH>;
 			clocks = <&ahb_gates 17>;
+			allwinner,sram = <&emac_sram 1>;
 			status = "disabled";
 		};