nios2: enable device tree control of U-Boot

This patch adds device tree control of U-Boot to nios2 boards.
The example dts is taken from Linux kernel.
Signed-off-by: Thomas Chou <thomas@wytron.com.tw>
Reviewed-by: Simon Glass <sjg@chromium.org>
Acked-by: Marek Vasut <marex@denx.de>

arch/nios2/dts/.gitignore

+*.dtb

arch/nios2/dts/3c120_devboard.dts

+/*
+ *  Copyright (C) 2013 Altera Corporation
+ *
+ * This file is generated by sopc2dts.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+/dts-v1/;
+
+/ {
+	model = "altr,qsys_ghrd_3c120";
+	compatible = "altr,qsys_ghrd_3c120";
+	#address-cells = <1>;
+	#size-cells = <1>;
+
+	cpus {
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		cpu: cpu@0x0 {
+			device_type = "cpu";
+			compatible = "altr,nios2-1.0";
+			reg = <0x00000000>;
+			interrupt-controller;
+			#interrupt-cells = <1>;
+			clock-frequency = <125000000>;
+			dcache-line-size = <32>;
+			icache-line-size = <32>;
+			dcache-size = <32768>;
+			icache-size = <32768>;
+			altr,implementation = "fast";
+			altr,pid-num-bits = <8>;
+			altr,tlb-num-ways = <16>;
+			altr,tlb-num-entries = <128>;
+			altr,tlb-ptr-sz = <7>;
+			altr,has-div = <1>;
+			altr,has-mul = <1>;
+			altr,reset-addr = <0xc2800000>;
+			altr,fast-tlb-miss-addr = <0xc7fff400>;
+			altr,exception-addr = <0xd0000020>;
+			altr,has-initda = <1>;
+			altr,has-mmu = <1>;
+		};
+	};
+
+	memory@0 {
+		device_type = "memory";
+		reg = <0x10000000 0x08000000>,
+			<0x07fff400 0x00000400>;
+	};
+
+	sopc@0 {
+		device_type = "soc";
+		ranges;
+		#address-cells = <1>;
+		#size-cells = <1>;
+		compatible = "altr,avalon", "simple-bus";
+		bus-frequency = <125000000>;
+
+		pb_cpu_to_io: bridge@0x8000000 {
+			compatible = "simple-bus";
+			reg = <0x08000000 0x00800000>;
+			#address-cells = <1>;
+			#size-cells = <1>;
+			ranges = <0x00002000 0x08002000 0x00002000>,
+				<0x00004000 0x08004000 0x00000400>,
+				<0x00004400 0x08004400 0x00000040>,
+				<0x00004800 0x08004800 0x00000040>,
+				<0x00004c80 0x08004c80 0x00000020>,
+				<0x00004d50 0x08004d50 0x00000008>,
+				<0x00008000 0x08008000 0x00000020>,
+				<0x00400000 0x08400000 0x00000020>;
+
+			timer_1ms: timer@0x400000 {
+				compatible = "altr,timer-1.0";
+				reg = <0x00400000 0x00000020>;
+				interrupt-parent = <&cpu>;
+				interrupts = <11>;
+				clock-frequency = <125000000>;
+			};
+
+			timer_0: timer@0x8000 {
+				compatible = "altr,timer-1.0";
+				reg = < 0x00008000 0x00000020 >;
+				interrupt-parent = < &cpu >;
+				interrupts = < 5 >;
+				clock-frequency = < 125000000 >;
+			};
+
+			jtag_uart: serial@0x4d50 {
+				compatible = "altr,juart-1.0";
+				reg = <0x00004d50 0x00000008>;
+				interrupt-parent = <&cpu>;
+				interrupts = <1>;
+			};
+
+			tse_mac: ethernet@0x4000 {
+				compatible = "altr,tse-1.0";
+				reg = <0x00004000 0x00000400>,
+					<0x00004400 0x00000040>,
+					<0x00004800 0x00000040>,
+					<0x00002000 0x00002000>;
+				reg-names = "control_port", "rx_csr", "tx_csr", "s1";
+				interrupt-parent = <&cpu>;
+				interrupts = <2 3>;
+				interrupt-names = "rx_irq", "tx_irq";
+				rx-fifo-depth = <8192>;
+				tx-fifo-depth = <8192>;
+				max-frame-size = <1518>;
+				local-mac-address = [ 00 00 00 00 00 00 ];
+				phy-mode = "rgmii-id";
+				phy-handle = <&phy0>;
+				tse_mac_mdio: mdio {
+					compatible = "altr,tse-mdio";
+					#address-cells = <1>;
+					#size-cells = <0>;
+					phy0: ethernet-phy@18 {
+						reg = <18>;
+						device_type = "ethernet-phy";
+					};
+				};
+			};
+
+			uart: serial@0x4c80 {
+				compatible = "altr,uart-1.0";
+				reg = <0x00004c80 0x00000020>;
+				interrupt-parent = <&cpu>;
+				interrupts = <10>;
+				current-speed = <115200>;
+				clock-frequency = <62500000>;
+			};
+		};
+
+		cfi_flash_64m: flash@0x0 {
+			compatible = "cfi-flash";
+			reg = <0x00000000 0x04000000>;
+			bank-width = <2>;
+			device-width = <1>;
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			partition@800000 {
+				reg = <0x00800000 0x01e00000>;
+				label = "JFFS2 Filesystem";
+			};
+		};
+	};
+
+	chosen {
+		bootargs = "debug console=ttyJ0,115200";
+	};
+};

arch/nios2/dts/Makefile

+dtb-y += $(CONFIG_DEFAULT_DEVICE_TREE:"%"=%).dtb
+
+targets += $(dtb-y)
+
+DTC_FLAGS += -R 4 -p 0x1000
+
+PHONY += dtbs
+dtbs: $(addprefix $(obj)/, $(dtb-y))
+	@:
+
+clean-files := *.dtb

arch/nios2/dts/include/dt-bindings

+../../../../include/dt-bindings
\ No newline at end of file

configs/nios2-generic_defconfig

 CONFIG_NIOS2=y
 CONFIG_TARGET_NIOS2_GENERIC=y
+CONFIG_DEFAULT_DEVICE_TREE="3c120_devboard"
 CONFIG_HUSH_PARSER=y
 # CONFIG_CMD_BOOTD is not set
 # CONFIG_CMD_IMLS is not set
@@ -10,4 +11,5 @@ CONFIG_HUSH_PARSER=y
 CONFIG_CMD_DHCP=y
 # CONFIG_CMD_NFS is not set
 CONFIG_CMD_PING=y
+CONFIG_OF_CONTROL=y
 CONFIG_NET_RANDOM_ETHADDR=y