mips: Add LinkIt Smart 7688 support

The LinkIt Smart 7688 modules have a MT7688 SoC with 128 MiB of RAM
and 32 MiB of flash (SPI NOR).

This patch also includes 2 targets. One is the target that can be
programmed into the SPI NOR flash and a 2nd target "xxx-ram" is
added to support loading and booting via an already running U-Boot
version. This allows easy development and testing without the
need to flash the image each time.

Signed-off-by: Stefan Roese <sr@denx.de>
[fixed and regenerated defconfig files]
Signed-off-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>

arch/mips/dts/linkit-smart-7688.dts

@@ -0,0 +1,46 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2018 Stefan Roese <sr@denx.de>
+ */
+
+/dts-v1/;
+
+#include "mt7628a.dtsi"
+
+/ {
+	compatible = "seeed,linkit-smart-7688", "ralink,mt7628a-soc";
+	model = "LinkIt-Smart-7688";
+
+	aliases {
+		serial0 = &uart2;
+		spi0 = &spi0;
+	};
+
+	memory@0 {
+		device_type = "memory";
+		reg = <0x0 0x08000000>;
+	};
+
+	chosen {
+		bootargs = "console=ttyS0,57600";
+		stdout-path = &uart2;
+	};
+};
+
+&uart2 {
+	status = "okay";
+	clock-frequency = <40000000>;
+};
+
+&spi0 {
+	status = "okay";
+	num-cs = <2>;
+
+	spi-flash@0 {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		compatible = "spi-flash", "jedec,spi-nor";
+		spi-max-frequency = <25000000>;
+		reg = <0>;
+	};
+};

arch/mips/mach-mt7620/Kconfig

@@ -21,6 +21,17 @@ endchoice
 choice
 	prompt "Board select"
 
+config BOARD_LINKIT_SMART_7688
+	bool "LinkIt Smart 7688"
+	depends on SOC_MT7620
+	select SUPPORTS_BOOT_RAM
+	help
+	  Seeed LinkIt Smart 7688 boards have a MT7688 SoC with 128 MiB of RAM
+	  and 32 MiB of flash (SPI).
+	  Between its different peripherals there's an integrated switch with 4
+	  ethernet ports, 1 USB port, 1 UART, GPIO buttons and LEDs, and
+	  a MT7688 (PCIe).
+
 endchoice
 
 choice
@@ -110,4 +121,6 @@ endchoice
 config SUPPORTS_BOOT_RAM
 	bool
 
+source "board/seeed/linkit-smart-7688/Kconfig"
+
 endmenu

board/seeed/linkit-smart-7688/Kconfig

@@ -0,0 +1,12 @@
+if BOARD_LINKIT_SMART_7688
+
+config SYS_BOARD
+	default "linkit-smart-7688"
+
+config SYS_VENDOR
+	default "seeed"
+
+config SYS_CONFIG_NAME
+	default "linkit-smart-7688"
+
+endif

board/seeed/linkit-smart-7688/MAINTAINERS

@@ -0,0 +1,8 @@
+LINKIT_SMART_7688 BOARD
+M:	Stefan Roese <sr@denx.de>
+S:	Maintained
+F:	board/seeed/linkit-smart-7688
+F:	include/configs/linkit-smart-7688.h
+F:	configs/linkit-smart-7688_defconfig
+F:	configs/linkit-smart-7688_ram_defconfig
+F:	arch/mips/dts/linkit-smart-7688.dts

board/seeed/linkit-smart-7688/Makefile

@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0+
+
+obj-y += board.o

board/seeed/linkit-smart-7688/board.c

@@ -0,0 +1,26 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2018 Stefan Roese <sr@denx.de>
+ */
+
+#include <common.h>
+#include <asm/io.h>
+
+#define MT76XX_GPIO1_MODE	0xb0000060
+
+void board_debug_uart_init(void)
+{
+	/* Select UART2 mode instead of GPIO mode (default) */
+	clrbits_le32((void __iomem *)MT76XX_GPIO1_MODE, GENMASK(27, 26));
+}
+
+int board_early_init_f(void)
+{
+	/*
+	 * The pin muxing of UART2 also needs to be done, if debug uart
+	 * is not enabled. So we need to call this function here as well.
+	 */
+	board_debug_uart_init();
+
+	return 0;
+}

configs/linkit-smart-7688-ram_defconfig

@@ -0,0 +1,51 @@
+CONFIG_MIPS=y
+CONFIG_SYS_TEXT_BASE=0x80010000
+CONFIG_ARCH_MT7620=y
+# CONFIG_MIPS_BOOT_CMDLINE_LEGACY is not set
+# CONFIG_MIPS_BOOT_ENV_LEGACY is not set
+CONFIG_MIPS_BOOT_FDT=y
+CONFIG_NR_DRAM_BANKS=1
+# CONFIG_SYS_MALLOC_CLEAR_ON_INIT is not set
+CONFIG_OF_STDOUT_VIA_ALIAS=y
+CONFIG_SYS_CONSOLE_INFO_QUIET=y
+CONFIG_BOARD_EARLY_INIT_F=y
+CONFIG_HUSH_PARSER=y
+CONFIG_CMD_CPU=y
+CONFIG_CMD_LICENSE=y
+# CONFIG_CMD_BOOTD is not set
+# CONFIG_CMD_ELF is not set
+# CONFIG_CMD_XIMG is not set
+CONFIG_CMD_MEMINFO=y
+# CONFIG_CMD_FLASH is not set
+# CONFIG_CMD_LOADS is not set
+CONFIG_CMD_SF=y
+CONFIG_CMD_SPI=y
+# CONFIG_CMD_NET is not set
+CONFIG_CMD_TIME=y
+CONFIG_OF_EMBED=y
+CONFIG_DEFAULT_DEVICE_TREE="linkit-smart-7688"
+CONFIG_ENV_IS_IN_SPI_FLASH=y
+# CONFIG_DM_DEVICE_REMOVE is not set
+CONFIG_HAVE_BLOCK_DEVICE=y
+CONFIG_CLK=y
+CONFIG_CPU=y
+CONFIG_DM_GPIO=y
+CONFIG_LED=y
+CONFIG_LED_BLINK=y
+CONFIG_LED_GPIO=y
+CONFIG_SPI_FLASH=y
+CONFIG_SPI_FLASH_GIGADEVICE=y
+CONFIG_SPI_FLASH_MACRONIX=y
+CONFIG_SPI_FLASH_SPANSION=y
+CONFIG_SPI_FLASH_STMICRO=y
+CONFIG_SPI_FLASH_WINBOND=y
+CONFIG_SPI_FLASH_MTD=y
+CONFIG_PHY=y
+CONFIG_POWER_DOMAIN=y
+CONFIG_RAM=y
+CONFIG_DM_RESET=y
+CONFIG_BAUDRATE=57600
+# CONFIG_SPL_SERIAL_PRESENT is not set
+CONFIG_SYS_NS16550=y
+CONFIG_SPI=y
+CONFIG_SYSRESET_SYSCON=y

configs/linkit-smart-7688_defconfig

@@ -0,0 +1,55 @@
+CONFIG_MIPS=y
+CONFIG_SYS_TEXT_BASE=0x9c000000
+CONFIG_ARCH_MT7620=y
+CONFIG_BOOT_ROM=y
+CONFIG_ONBOARD_DDR2_SIZE_1024MBIT=y
+CONFIG_ONBOARD_DDR2_CHIP_WIDTH_16BIT=y
+# CONFIG_MIPS_BOOT_CMDLINE_LEGACY is not set
+# CONFIG_MIPS_BOOT_ENV_LEGACY is not set
+CONFIG_MIPS_BOOT_FDT=y
+CONFIG_NR_DRAM_BANKS=1
+# CONFIG_SYS_MALLOC_CLEAR_ON_INIT is not set
+CONFIG_OF_STDOUT_VIA_ALIAS=y
+CONFIG_SYS_CONSOLE_INFO_QUIET=y
+CONFIG_BOARD_EARLY_INIT_F=y
+CONFIG_HUSH_PARSER=y
+CONFIG_CMD_CPU=y
+CONFIG_CMD_LICENSE=y
+# CONFIG_CMD_BOOTD is not set
+# CONFIG_CMD_ELF is not set
+# CONFIG_CMD_XIMG is not set
+# CONFIG_CMD_CRC32 is not set
+CONFIG_CMD_MEMINFO=y
+# CONFIG_CMD_FLASH is not set
+# CONFIG_CMD_LOADS is not set
+CONFIG_CMD_SF=y
+CONFIG_CMD_SPI=y
+# CONFIG_CMD_NET is not set
+CONFIG_CMD_TIME=y
+CONFIG_OF_EMBED=y
+CONFIG_DEFAULT_DEVICE_TREE="linkit-smart-7688"
+CONFIG_ENV_IS_IN_SPI_FLASH=y
+# CONFIG_DM_DEVICE_REMOVE is not set
+CONFIG_HAVE_BLOCK_DEVICE=y
+CONFIG_CLK=y
+CONFIG_CPU=y
+CONFIG_DM_GPIO=y
+CONFIG_LED=y
+CONFIG_LED_BLINK=y
+CONFIG_LED_GPIO=y
+CONFIG_SPI_FLASH=y
+CONFIG_SPI_FLASH_GIGADEVICE=y
+CONFIG_SPI_FLASH_MACRONIX=y
+CONFIG_SPI_FLASH_SPANSION=y
+CONFIG_SPI_FLASH_STMICRO=y
+CONFIG_SPI_FLASH_WINBOND=y
+CONFIG_SPI_FLASH_MTD=y
+CONFIG_PHY=y
+CONFIG_POWER_DOMAIN=y
+CONFIG_RAM=y
+CONFIG_DM_RESET=y
+CONFIG_BAUDRATE=57600
+# CONFIG_SPL_SERIAL_PRESENT is not set
+CONFIG_SYS_NS16550=y
+CONFIG_SPI=y
+CONFIG_SYSRESET_SYSCON=y

include/configs/linkit-smart-7688.h

@@ -0,0 +1,51 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (C) 2018 Stefan Roese <sr@denx.de>
+ */
+
+#ifndef __CONFIG_LINKIT_SMART_7688_H
+#define __CONFIG_LINKIT_SMART_7688_H
+
+/* CPU */
+#define CONFIG_SYS_MIPS_TIMER_FREQ	200000000
+
+/* RAM */
+#define CONFIG_SYS_SDRAM_BASE		0x80000000
+
+#define CONFIG_SYS_LOAD_ADDR		CONFIG_SYS_SDRAM_BASE + 0x100000
+
+#define CONFIG_SYS_INIT_SP_OFFSET	0x400000
+
+#ifdef CONFIG_BOOT_RAM
+#define CONFIG_SKIP_LOWLEVEL_INIT
+#endif
+
+/* UART */
+#define CONFIG_SYS_BAUDRATE_TABLE	{ 9600, 19200, 38400, 57600, 115200, \
+					  230400, 500000, 1500000 }
+
+/* RAM */
+#define CONFIG_SYS_MEMTEST_START	0x80100000
+#define CONFIG_SYS_MEMTEST_END		0x80400000
+
+/* Memory usage */
+#define CONFIG_SYS_MAXARGS		64
+#define CONFIG_SYS_MALLOC_LEN		(1024 * 1024)
+#define CONFIG_SYS_BOOTPARAMS_LEN	(128 * 1024)
+#define CONFIG_SYS_CBSIZE		512
+
+/* U-Boot */
+#define CONFIG_SYS_MONITOR_BASE		CONFIG_SYS_TEXT_BASE
+
+/* Environment settings */
+#define CONFIG_ENV_OFFSET		0x40000
+#define CONFIG_ENV_SIZE			(16 << 10)
+#define CONFIG_ENV_SECT_SIZE		(64 << 10)
+
+/*
+ * Environment is right behind U-Boot in flash. Make sure U-Boot
+ * doesn't grow into the environment area.
+ */
+#define CONFIG_BOARD_SIZE_LIMIT		CONFIG_ENV_OFFSET
+
+#endif /* __CONFIG_LINKIT_SMART_7688_H */