arm64: mvebu: Add Armada 3700 db-88f3720 development board support

This patch adds basic support for the Marvell Armada 3700 DB-88F3720
development board. Supported are the following interfaces:
- UART
- SPI (incl. SPI NOR)
- I2C
- Ethernet

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Nadav Haklai <nadavh@marvell.com>
Cc: Kostya Porotchkin <kostap@marvell.com>
Cc: Wilson Ding <dingwei@marvell.com>
Cc: Victor Gu <xigu@marvell.com>
Cc: Hua Jing <jinghua@marvell.com>
Cc: Terry Zhou <bjzhou@marvell.com>
Cc: Hanna Hawa <hannah@marvell.com>
Cc: Haim Boot <hayim@marvell.com>
diff --git a/board/Marvell/mvebu_db-88f3720/board.c b/board/Marvell/mvebu_db-88f3720/board.c
new file mode 100644
index 0000000..edf88c7
--- /dev/null
+++ b/board/Marvell/mvebu_db-88f3720/board.c
@@ -0,0 +1,134 @@
+/*
+ * Copyright (C) 2016 Stefan Roese <sr@denx.de>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <i2c.h>
+#include <asm/io.h>
+#include <asm/arch/cpu.h>
+#include <asm/arch/soc.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/* IO expander I2C device */
+#define I2C_IO_EXP_ADDR		0x22
+#define I2C_IO_CFG_REG_0	0x6
+#define I2C_IO_DATA_OUT_REG_0	0x2
+#define I2C_IO_REG_0_SATA_OFF	2
+#define I2C_IO_REG_0_USB_H_OFF	1
+
+int board_early_init_f(void)
+{
+	/* Nothing to do (yet), perhaps later some pin-muxing etc */
+
+	return 0;
+}
+
+int board_init(void)
+{
+	/* adress of boot parameters */
+	gd->bd->bi_boot_params = CONFIG_SYS_SDRAM_BASE + 0x100;
+
+	return 0;
+}
+
+/* Board specific AHCI / SATA enable code */
+int board_ahci_enable(void)
+{
+	struct udevice *dev;
+	int ret;
+	u8 buf[8];
+
+	/* Configure IO exander PCA9555: 7bit address 0x22 */
+	ret = i2c_get_chip_for_busnum(0, I2C_IO_EXP_ADDR, 1, &dev);
+	if (ret) {
+		printf("Cannot find PCA9555: %d\n", ret);
+		return 0;
+	}
+
+	ret = dm_i2c_read(dev, I2C_IO_CFG_REG_0, buf, 1);
+	if (ret) {
+		printf("Failed to read IO expander value via I2C\n");
+		return -EIO;
+	}
+
+	/*
+	 * Enable SATA power via IO expander connected via I2C by setting
+	 * the corresponding bit to output mode to enable power for SATA
+	 */
+	buf[0] &= ~(1 << I2C_IO_REG_0_SATA_OFF);
+	ret = dm_i2c_write(dev, I2C_IO_CFG_REG_0, buf, 1);
+	if (ret) {
+		printf("Failed to set IO expander via I2C\n");
+		return -EIO;
+	}
+
+	return 0;
+}
+
+/* Board specific xHCI enable code */
+int board_xhci_enable(void)
+{
+	struct udevice *dev;
+	int ret;
+	u8 buf[8];
+
+	/* Configure IO exander PCA9555: 7bit address 0x22 */
+	ret = i2c_get_chip_for_busnum(0, I2C_IO_EXP_ADDR, 1, &dev);
+	if (ret) {
+		printf("Cannot find PCA9555: %d\n", ret);
+		return 0;
+	}
+
+	printf("Enable USB VBUS\n");
+
+	/*
+	 * Read configuration (direction) and set VBUS pin as output
+	 * (reset pin = output)
+	 */
+	ret = dm_i2c_read(dev, I2C_IO_CFG_REG_0, buf, 1);
+	if (ret) {
+		printf("Failed to read IO expander value via I2C\n");
+		return -EIO;
+	}
+	buf[0] &= ~(1 << I2C_IO_REG_0_USB_H_OFF);
+	ret = dm_i2c_write(dev, I2C_IO_CFG_REG_0, buf, 1);
+	if (ret) {
+		printf("Failed to set IO expander via I2C\n");
+		return -EIO;
+	}
+
+	/* Read VBUS output value and disable it */
+	ret = dm_i2c_read(dev, I2C_IO_DATA_OUT_REG_0, buf, 1);
+	if (ret) {
+		printf("Failed to read IO expander value via I2C\n");
+		return -EIO;
+	}
+	buf[0] &= ~(1 << I2C_IO_REG_0_USB_H_OFF);
+	ret = dm_i2c_write(dev, I2C_IO_DATA_OUT_REG_0, buf, 1);
+	if (ret) {
+		printf("Failed to set IO expander via I2C\n");
+		return -EIO;
+	}
+
+	/*
+	 * Required delay for configuration to settle - must wait for
+	 * power on port is disabled in case VBUS signal was high,
+	 * required 3 seconds delay to let VBUS signal fully settle down
+	 */
+	mdelay(3000);
+
+	/* Enable VBUS power: Set output value of VBUS pin as enabled */
+	buf[0] |= (1 << I2C_IO_REG_0_USB_H_OFF);
+	ret = dm_i2c_write(dev, I2C_IO_DATA_OUT_REG_0, buf, 1);
+	if (ret) {
+		printf("Failed to set IO expander via I2C\n");
+		return -EIO;
+	}
+
+	mdelay(500); /* required delay to let output value settle */
+
+	return 0;
+}