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/include/configs/iot2050.h b/include/configs/iot2050.h
new file mode 100644
index 0000000..ddb4cfc
--- /dev/null
+++ b/include/configs/iot2050.h
@@ -0,0 +1,62 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Configuration header file for IOT2050
+ * Copyright (c) Siemens AG, 2018-2021
+ *
+ * Authors:
+ *   Le Jin <le.jin@siemens.com>
+ *   Jan Kiszka <jan.kiszka@siemens.com>
+ */
+
+#ifndef __CONFIG_IOT2050_H
+#define __CONFIG_IOT2050_H
+
+#include <linux/sizes.h>
+
+/* SPL Loader Configuration */
+#define CONFIG_SYS_INIT_SP_ADDR		(CONFIG_SPL_TEXT_BASE + \
+					 CONFIG_SYS_K3_NON_SECURE_MSRAM_SIZE)
+
+#define CONFIG_SKIP_LOWLEVEL_INIT
+
+#define CONFIG_SPL_MAX_SIZE		CONFIG_SYS_K3_MAX_DOWNLODABLE_IMAGE_SIZE
+
+#define CONFIG_SYS_BOOTM_LEN		SZ_64M
+
+/* U-Boot general configuration */
+#define EXTRA_ENV_IOT2050_BOARD_SETTINGS				\
+	"usb_pgood_delay=900\0"
+
+#ifndef CONFIG_SPL_BUILD
+
+#if CONFIG_IS_ENABLED(CMD_USB)
+# define BOOT_TARGET_USB(func) \
+	func(USB, usb, 0) \
+	func(USB, usb, 1) \
+	func(USB, usb, 2)
+#else
+# define BOOT_TARGET_USB(func)
+#endif
+
+/*
+ * This defines all MMC devices, even if the basic variant has no mmc1.
+ * The non-supported device will be removed from the boot targets during
+ * runtime, when that board was detected.
+ */
+#define BOOT_TARGET_DEVICES(func) \
+	func(MMC, mmc, 1) \
+	func(MMC, mmc, 0) \
+	BOOT_TARGET_USB(func)
+
+#include <config_distro_bootcmd.h>
+
+#endif
+
+#define CONFIG_EXTRA_ENV_SETTINGS					\
+	DEFAULT_LINUX_BOOT_ENV						\
+	BOOTENV								\
+	EXTRA_ENV_IOT2050_BOARD_SETTINGS
+
+#include <configs/ti_armv7_common.h>
+
+#endif /* __CONFIG_IOT2050_H */