arm64: mvebu: Add Armada 7K db-88f7040 development board support

This patch adds basic support for the Marvell Armada 7K DB-88F7040
development board. Supported are the following interfaces:
- UART
- SPI (incl. SPI NOR)
- I2C
- USB
- SATA / AHCI

Support for other interfaces will follow.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Nadav Haklai <nadavh@marvell.com>
Cc: Neta Zur Hershkovits <neta@marvell.com>
Cc: Kostya Porotchkin <kostap@marvell.com>
Cc: Omri Itach <omrii@marvell.com>
Cc: Igal Liberman <igall@marvell.com>
Cc: Haim Boot <hayim@marvell.com>
Cc: Hanna Hawa <hannah@marvell.com>
diff --git a/board/Marvell/mvebu_db-88f7040/MAINTAINERS b/board/Marvell/mvebu_db-88f7040/MAINTAINERS
new file mode 100644
index 0000000..820461b
--- /dev/null
+++ b/board/Marvell/mvebu_db-88f7040/MAINTAINERS
@@ -0,0 +1,6 @@
+MVEBU_DB_88F7040 BOARD
+M:	Stefan Roese <sr@denx.de>
+S:	Maintained
+F:	board/Marvell/mvebu_db-88f7040/
+F:	include/configs/mvebu_db-88f7040.h
+F:	configs/mvebu_db-88f7040_defconfig
diff --git a/board/Marvell/mvebu_db-88f7040/Makefile b/board/Marvell/mvebu_db-88f7040/Makefile
new file mode 100644
index 0000000..ed39738
--- /dev/null
+++ b/board/Marvell/mvebu_db-88f7040/Makefile
@@ -0,0 +1,7 @@
+#
+# Copyright (C) 2016 Stefan Roese <sr@denx.de>
+#
+# SPDX-License-Identifier:	GPL-2.0+
+#
+
+obj-y	:= board.o
diff --git a/board/Marvell/mvebu_db-88f7040/board.c b/board/Marvell/mvebu_db-88f7040/board.c
new file mode 100644
index 0000000..48bd55c
--- /dev/null
+++ b/board/Marvell/mvebu_db-88f7040/board.c
@@ -0,0 +1,152 @@
+/*
+ * 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		0x21
+#define I2C_IO_CFG_REG_0	0x6
+#define I2C_IO_DATA_OUT_REG_0	0x2
+/* VBus enable */
+#define I2C_IO_REG_0_USB_H0_OFF	0
+#define I2C_IO_REG_0_USB_H1_OFF	1
+#define I2C_IO_REG_VBUS		((1 << I2C_IO_REG_0_USB_H0_OFF) | \
+				 (1 << I2C_IO_REG_0_USB_H1_OFF))
+/* Current limit */
+#define I2C_IO_REG_0_USB_H0_CL	4
+#define I2C_IO_REG_0_USB_H1_CL	5
+#define I2C_IO_REG_CL		((1 << I2C_IO_REG_0_USB_H0_CL) | \
+				 (1 << I2C_IO_REG_0_USB_H1_CL))
+
+static int usb_enabled = 0;
+
+/* Board specific xHCI dis-/enable code */
+
+/*
+ * Set USB VBUS signals (via I2C IO expander/GPIO) as output and set
+ * output value as disabled
+ *
+ * Set USB Current Limit signals (via I2C IO expander/GPIO) as output
+ * and set output value as enabled
+ */
+int board_xhci_config(void)
+{
+	struct udevice *dev;
+	int ret;
+	u8 buf[8];
+
+	/* Configure IO exander PCA9555: 7bit address 0x21 */
+	ret = i2c_get_chip_for_busnum(0, I2C_IO_EXP_ADDR, 1, &dev);
+	if (ret) {
+		printf("Cannot find PCA9555: %d\n", ret);
+		return 0;
+	}
+
+	/*
+	 * 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] &= ~I2C_IO_REG_VBUS;
+	buf[0] &= ~I2C_IO_REG_CL;
+	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 output value and configure 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] &= ~I2C_IO_REG_VBUS;
+	buf[0] |= I2C_IO_REG_CL;
+	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;
+}
+
+int board_xhci_enable(void)
+{
+	struct udevice *dev;
+	int ret;
+	u8 buf[8];
+
+	/*
+	 * This function enables all USB ports simultaniously,
+	 * it only needs to get called once
+	 */
+	if (usb_enabled)
+		return 0;
+
+	/* Configure IO exander PCA9555: 7bit address 0x21 */
+	ret = i2c_get_chip_for_busnum(0, I2C_IO_EXP_ADDR, 1, &dev);
+	if (ret) {
+		printf("Cannot find PCA9555: %d\n", ret);
+		return 0;
+	}
+
+	/* Read VBUS output value */
+	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;
+	}
+
+	/* Enable VBUS power: Set output value of VBUS pin as enabled */
+	buf[0] |= I2C_IO_REG_VBUS;
+	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 */
+	usb_enabled = 1;
+
+	return 0;
+}
+
+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;
+}
+
+int board_late_init(void)
+{
+	/* Pre-configure the USB ports (overcurrent, VBus) */
+	board_xhci_config();
+
+	return 0;
+}