board: siemens: Add support for SIMATIC IOT2050 devices

This adds support for the IOT2050 Basic and Advanced devices. The Basic
used the dual-core AM6528 GP processor, the Advanced one the AM6548 HS
quad-core version.

Both variants are booted via a Siemens-provided FSBL that runs on the R5
cores. Consequently, U-Boot support is targeting the A53 cores. U-Boot
SPL, ATF and TEE have to reside in SPI flash.

Full integration into a bootable image can be found on
https://github.com/siemens/meta-iot2050

Based on original board support by Le Jin, Gao Nian and Chao Zeng.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
diff --git a/board/siemens/iot2050/Kconfig b/board/siemens/iot2050/Kconfig
new file mode 100644
index 0000000..8f634c1
--- /dev/null
+++ b/board/siemens/iot2050/Kconfig
@@ -0,0 +1,32 @@
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Copyright (c) Siemens AG, 2018-2021
+#
+# Authors:
+#   Le Jin <le.jin@siemens.com>
+#   Jan Kiszka <jan.kiszka@siemens.com>
+
+config TARGET_IOT2050_A53
+	bool "IOT2050 running on A53"
+	select ARM64
+	select SOC_K3_AM6
+	select BOARD_LATE_INIT
+	select SYS_DISABLE_DCACHE_OPS
+	select BINMAN
+
+if TARGET_IOT2050_A53
+
+config SYS_BOARD
+	default "iot2050"
+
+config SYS_VENDOR
+	default "siemens"
+
+config SYS_CONFIG_NAME
+	default "iot2050"
+
+config IOT2050_BOOT_SWITCH
+	bool "Disable eMMC boot via USER button (Advanced version only)"
+	default y
+
+endif
diff --git a/board/siemens/iot2050/MAINTAINERS b/board/siemens/iot2050/MAINTAINERS
new file mode 100644
index 0000000..1b52535
--- /dev/null
+++ b/board/siemens/iot2050/MAINTAINERS
@@ -0,0 +1,9 @@
+IOT2050 BOARD
+M:	Le Jin <le.jin@siemens.com>
+M:	Jan Kiszka <jan.kiszka@siemens.com>
+S:	Maintained
+F:	board/siemens/iot2050/
+F:	include/configs/iot2050.h
+F:	configs/iot2050_defconfig
+F:	arch/arm/dts/iot2050-*
+F:	doc/board/siemens/iot2050.rst
diff --git a/board/siemens/iot2050/Makefile b/board/siemens/iot2050/Makefile
new file mode 100644
index 0000000..619594a
--- /dev/null
+++ b/board/siemens/iot2050/Makefile
@@ -0,0 +1,10 @@
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Makefile for Siemens IOT2050 board
+# Copyright (c) Siemens AG, 2018-2021
+#
+# Authors:
+#   Le Jin <le.jin@siemens.com>
+#
+
+obj-y += board.o
diff --git a/board/siemens/iot2050/board.c b/board/siemens/iot2050/board.c
new file mode 100644
index 0000000..b211097
--- /dev/null
+++ b/board/siemens/iot2050/board.c
@@ -0,0 +1,272 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Board specific initialization for IOT2050
+ * Copyright (c) Siemens AG, 2018-2021
+ *
+ * Authors:
+ *   Le Jin <le.jin@siemens.com>
+ *   Jan Kiszka <jan.kiszka@siemens.com>
+ */
+
+#include <common.h>
+#include <bootstage.h>
+#include <dm.h>
+#include <i2c.h>
+#include <led.h>
+#include <malloc.h>
+#include <net.h>
+#include <phy.h>
+#include <spl.h>
+#include <version.h>
+#include <linux/delay.h>
+#include <asm/arch/sys_proto.h>
+#include <asm/arch/hardware.h>
+#include <asm/gpio.h>
+#include <asm/io.h>
+
+#define IOT2050_INFO_MAGIC		0x20502050
+
+struct iot2050_info {
+	u32 magic;
+	u16 size;
+	char name[20 + 1];
+	char serial[16 + 1];
+	char mlfb[18 + 1];
+	char uuid[32 + 1];
+	char a5e[18 + 1];
+	u8 mac_addr_cnt;
+	u8 mac_addr[8][ARP_HLEN];
+	char seboot_version[40 + 1];
+} __packed;
+
+/*
+ * Scratch SRAM (available before DDR RAM) contains extracted EEPROM data.
+ */
+#define IOT2050_INFO_DATA ((struct iot2050_info *) \
+			     TI_SRAM_SCRATCH_BOARD_EEPROM_START)
+
+DECLARE_GLOBAL_DATA_PTR;
+
+static bool board_is_advanced(void)
+{
+	struct iot2050_info *info = IOT2050_INFO_DATA;
+
+	return info->magic == IOT2050_INFO_MAGIC &&
+		strstr((char *)info->name, "IOT2050-ADVANCED") != NULL;
+}
+
+static bool board_is_sr1(void)
+{
+	struct iot2050_info *info = IOT2050_INFO_DATA;
+
+	return info->magic == IOT2050_INFO_MAGIC &&
+		!strstr((char *)info->name, "-PG2");
+}
+
+static void remove_mmc1_target(void)
+{
+	char *boot_targets = strdup(env_get("boot_targets"));
+	char *mmc1 = strstr(boot_targets, "mmc1");
+
+	if (mmc1) {
+		memmove(mmc1, mmc1 + 4, strlen(mmc1 + 4) + 1);
+		env_set("boot_targets", boot_targets);
+	}
+
+	free(boot_targets);
+}
+
+void set_board_info_env(void)
+{
+	struct iot2050_info *info = IOT2050_INFO_DATA;
+	u8 __maybe_unused mac_cnt;
+	const char *fdtfile;
+
+	if (info->magic != IOT2050_INFO_MAGIC) {
+		pr_err("IOT2050: Board info parsing error!\n");
+		return;
+	}
+
+	if (env_get("board_uuid"))
+		return;
+
+	env_set("board_name", info->name);
+	env_set("board_serial", info->serial);
+	env_set("mlfb", info->mlfb);
+	env_set("board_uuid", info->uuid);
+	env_set("board_a5e", info->a5e);
+	env_set("fw_version", PLAIN_VERSION);
+	env_set("seboot_version", info->seboot_version);
+
+	if (IS_ENABLED(CONFIG_NET)) {
+		/* set MAC addresses to ensure forwarding to the OS */
+		for (mac_cnt = 0; mac_cnt < info->mac_addr_cnt; mac_cnt++) {
+			if (is_valid_ethaddr(info->mac_addr[mac_cnt]))
+				eth_env_set_enetaddr_by_index("eth",
+							      mac_cnt + 1,
+							      info->mac_addr[mac_cnt]);
+		}
+	}
+
+	if (board_is_advanced()) {
+		if (board_is_sr1())
+			fdtfile = "ti/k3-am6548-iot2050-advanced.dtb";
+		else
+			fdtfile = "ti/k3-am6548-iot2050-advanced-pg2.dtb";
+	} else {
+		if (board_is_sr1())
+			fdtfile = "ti/k3-am6528-iot2050-basic.dtb";
+		else
+			fdtfile = "ti/k3-am6528-iot2050-basic-pg2.dtb";
+		/* remove the unavailable eMMC (mmc1) from the list */
+		remove_mmc1_target();
+	}
+	env_set("fdtfile", fdtfile);
+
+	env_save();
+}
+
+int board_init(void)
+{
+	return 0;
+}
+
+int dram_init(void)
+{
+	if (board_is_advanced())
+		gd->ram_size = SZ_2G;
+	else
+		gd->ram_size = SZ_1G;
+
+	return 0;
+}
+
+int dram_init_banksize(void)
+{
+	dram_init();
+
+	/* Bank 0 declares the memory available in the DDR low region */
+	gd->bd->bi_dram[0].start = CONFIG_SYS_SDRAM_BASE;
+	gd->bd->bi_dram[0].size = gd->ram_size;
+
+	/* Bank 1 declares the memory available in the DDR high region */
+	gd->bd->bi_dram[1].start = 0;
+	gd->bd->bi_dram[1].size = 0;
+
+	return 0;
+}
+
+#ifdef CONFIG_SPL_LOAD_FIT
+int board_fit_config_name_match(const char *name)
+{
+	struct iot2050_info *info = IOT2050_INFO_DATA;
+	char upper_name[32];
+
+	if (info->magic != IOT2050_INFO_MAGIC ||
+	    strlen(name) >= sizeof(upper_name))
+		return -1;
+
+	str_to_upper(name, upper_name, sizeof(upper_name));
+	if (!strcmp(upper_name, (char *)info->name))
+		return 0;
+
+	return -1;
+}
+#endif
+
+int do_board_detect(void)
+{
+	return 0;
+}
+
+#ifdef CONFIG_IOT2050_BOOT_SWITCH
+static bool user_button_pressed(void)
+{
+	struct udevice *red_led = NULL;
+	unsigned long count = 0;
+	struct gpio_desc gpio;
+
+	memset(&gpio, 0, sizeof(gpio));
+
+	if (dm_gpio_lookup_name("25", &gpio) < 0 ||
+	    dm_gpio_request(&gpio, "USER button") < 0 ||
+	    dm_gpio_set_dir_flags(&gpio, GPIOD_IS_IN) < 0)
+		return false;
+
+	if (dm_gpio_get_value(&gpio) == 1)
+		return false;
+
+	printf("USER button pressed - booting from external media only\n");
+
+	led_get_by_label("status-led-red", &red_led);
+
+	if (red_led)
+		led_set_state(red_led, LEDST_ON);
+
+	while (dm_gpio_get_value(&gpio) == 0 && count++ < 10000)
+		mdelay(1);
+
+	if (red_led)
+		led_set_state(red_led, LEDST_OFF);
+
+	return true;
+}
+#endif
+
+#define SERDES0_LANE_SELECT	0x00104080
+
+int board_late_init(void)
+{
+	/* change CTRL_MMR register to let serdes0 not output USB3.0 signals. */
+	writel(0x3, SERDES0_LANE_SELECT);
+
+	set_board_info_env();
+
+	/* remove the eMMC if requested via button */
+	if (IS_ENABLED(CONFIG_IOT2050_BOOT_SWITCH) && board_is_advanced() &&
+	    user_button_pressed())
+		remove_mmc1_target();
+
+	return 0;
+}
+
+#if defined(CONFIG_OF_LIBFDT) && defined(CONFIG_OF_BOARD_SETUP)
+int ft_board_setup(void *blob, struct bd_info *bd)
+{
+	int ret;
+
+	ret = fdt_fixup_msmc_ram(blob, "/bus@100000", "sram@70000000");
+	if (ret < 0)
+		ret = fdt_fixup_msmc_ram(blob, "/interconnect@100000",
+					 "sram@70000000");
+	if (ret)
+		pr_err("%s: fixing up msmc ram failed %d\n", __func__, ret);
+
+	return ret;
+}
+#endif
+
+void spl_board_init(void)
+{
+}
+
+#if CONFIG_IS_ENABLED(LED) && CONFIG_IS_ENABLED(BOOTSTAGE)
+/*
+ * Indicate any error or (accidental?) entering of CLI via the red status LED.
+ */
+void show_boot_progress(int progress)
+{
+	struct udevice *dev;
+	int ret;
+
+	if (progress < 0 || progress == BOOTSTAGE_ID_ENTER_CLI_LOOP) {
+		ret = led_get_by_label("status-led-green", &dev);
+		if (ret == 0)
+			led_set_state(dev, LEDST_OFF);
+
+		ret = led_get_by_label("status-led-red", &dev);
+		if (ret == 0)
+			led_set_state(dev, LEDST_ON);
+	}
+}
+#endif
diff --git a/board/siemens/iot2050/config.mk b/board/siemens/iot2050/config.mk
new file mode 100644
index 0000000..267ec76
--- /dev/null
+++ b/board/siemens/iot2050/config.mk
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Copyright (c) Siemens AG, 2020-2021
+#
+# Authors:
+#   Jan Kiszka <jan.kiszka@siemens.com>
+
+flash.bin: all