arm: mvebu: Add CRS305-1G-4S board

CRS305-1G-4S has a switch chip with an integrated CPU (98DX3236) and
like some of the other similar boards requires bin_hdr.
bin_hdr (DDR3 init stage) is currently retrieved from the stock
bootloader and compiled into the kwb image.

Adds support for U-Boot, enable UART, SPI, Winbond SPI flash chip
support and writing env to SPI flash.

Signed-off-by: Luka Kovacic <me@lukakovacic.xyz>
Reviewed-by: Chris Packham <judge.packham@gmail.com>
Reviewed-by: Stefan Roese <sr@denx.de>
Signed-off-by: Stefan Roese <sr@denx.de>
diff --git a/board/mikrotik/crs305-1g-4s/crs305-1g-4s.c b/board/mikrotik/crs305-1g-4s/crs305-1g-4s.c
new file mode 100644
index 0000000..d1d1f40
--- /dev/null
+++ b/board/mikrotik/crs305-1g-4s/crs305-1g-4s.c
@@ -0,0 +1,75 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2015 Stefan Roese <sr@denx.de>
+ */
+
+#include <common.h>
+#include <i2c.h>
+#include <asm/gpio.h>
+#include <linux/mbus.h>
+#include <linux/io.h>
+#include <asm/arch/cpu.h>
+#include <asm/arch/soc.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/*
+ * These values and defines are taken from the Marvell U-Boot version
+ * "u-boot-2013.01-2016_T1.0.eng_drop_v6"
+ */
+#define DB_DX_AC3_GPP_OUT_ENA_LOW	(~(BIT(0) | BIT(2) | BIT(3) | BIT(4) \
+					| BIT(6) | BIT(12) | BIT(13) \
+					| BIT(16) | BIT(17) | BIT(20) \
+					| BIT(29)  | BIT(30)))
+#define DB_DX_AC3_GPP_OUT_ENA_MID	(~(0))
+#define DB_DX_AC3_GPP_OUT_VAL_LOW	(BIT(0) | BIT(2) | BIT(3) | BIT(4) \
+					| BIT(6) | BIT(12) | BIT(13) \
+					| BIT(16) | BIT(17) | BIT(20) \
+					| BIT(29)  | BIT(30))
+#define DB_DX_AC3_GPP_OUT_VAL_MID	0x0
+#define DB_DX_AC3_GPP_POL_LOW		0x0
+#define DB_DX_AC3_GPP_POL_MID		0x0
+
+int board_early_init_f(void)
+{
+	/* Configure MPP */
+	writel(0x00142222, MVEBU_MPP_BASE + 0x00);
+	writel(0x11122000, MVEBU_MPP_BASE + 0x04);
+	writel(0x44444004, MVEBU_MPP_BASE + 0x08);
+	writel(0x14444444, MVEBU_MPP_BASE + 0x0c);
+	writel(0x00000001, MVEBU_MPP_BASE + 0x10);
+
+	/*
+	 * MVEBU_GPIO0_BASE is the User LED
+	 * MVEBU_GPIO1_BASE is the Reset Button (currently not used)
+	 */
+
+	/* Set GPP Out value */
+	writel(DB_DX_AC3_GPP_OUT_VAL_LOW, MVEBU_GPIO0_BASE + 0x00);
+	/* writel(DB_DX_AC3_GPP_OUT_VAL_MID, MVEBU_GPIO1_BASE + 0x00); */
+
+	/* Set GPP Polarity */
+	writel(DB_DX_AC3_GPP_POL_LOW, MVEBU_GPIO0_BASE + 0x0c);
+	/* writel(DB_DX_AC3_GPP_POL_MID, MVEBU_GPIO1_BASE + 0x0c); */
+
+	/* Set GPP Out Enable */
+	writel(DB_DX_AC3_GPP_OUT_ENA_LOW, MVEBU_GPIO0_BASE + 0x04);
+	/* writel(DB_DX_AC3_GPP_OUT_ENA_MID, MVEBU_GPIO1_BASE + 0x04); */
+
+	return 0;
+}
+
+int board_init(void)
+{
+	/* address of boot parameters */
+	gd->bd->bi_boot_params = mvebu_sdram_bar(0) + 0x100;
+
+	return 0;
+}
+
+int checkboard(void)
+{
+	puts("Board: " CONFIG_SYS_BOARD "\n");
+
+	return 0;
+}