feat(mediatek): introduce mtk init framework

Provide six initcall levels for drivers/modules initialize HW
controllers or runtime arguments during cold boot.

The initcall level cold boot execution order:

-MTK_EARLY_PLAT_INIT
Call before MMU enabled.

-MTK_ARCH_INIT
MMU Enabled, arch related init(GiC init, interrupt type registration).

-MTK_PLAT_SETUP_0_INIT
MTK driver init level 0.

-MTK_PLAT_SETUP_1_INIT
MTK driver init level 1.

-MTK_PLAT_RUNTIME_INIT
MTK driver init. After this initcall, TF-A handovers to MTK 2nd
bootloader.

-MTK_PLAT_BL33_DEFER_INIT
MTK 2nd bootloader traps to TF-A before handover to rich OS.
This initcall executed in the trap handler(boot_to_kernel).

Change-Id: Icd7fe95372441db73c975ccb6ce77a6c529df1cc
diff --git a/plat/mediatek/include/lib/mtk_init/mtk_init.h b/plat/mediatek/include/lib/mtk_init/mtk_init.h
new file mode 100644
index 0000000..6f23a9b
--- /dev/null
+++ b/plat/mediatek/include/lib/mtk_init/mtk_init.h
@@ -0,0 +1,58 @@
+/*
+ * Copyright (c) 2022, MediaTek Inc. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef MTK_INIT_H
+#define MTK_INIT_H
+
+#include <cdefs.h>
+#include <lib/mtk_init/mtk_init_def.h>
+
+#define INIT_CALL_EXPAND_AS_ENUMERATION(_section_enum, _section_name, _level) \
+	_section_enum = _level,
+
+#define EXPAND_AS_LINK_SECTION(_section_enum, _section_name, _level) \
+	__##_section_enum##_START__ = .; \
+	KEEP(*(_section_name##_level));
+
+#define EXPAND_AS_EXTERN(_section_enum, _section_name, _level) \
+	extern struct initcall __##_section_enum##_START__[];
+
+#define EXPAND_AS_SYMBOL_ARR(_section_enum, _section_name, _level) \
+	__##_section_enum##_START__,
+
+#define DECLARE_MTK_INITCALL(_fn, _level) \
+	const struct initcall _mtk_initcall_##_fn \
+	__used \
+	__aligned(sizeof(void *)) \
+	__section(".mtk_plat_initcall_"#_level) \
+	= { \
+		.name = #_fn, \
+		.fn = _fn \
+	}
+
+/* initcall helpers  */
+#define MTK_EARLY_PLAT_INIT(_fn) DECLARE_MTK_INITCALL(_fn, 0)
+#define MTK_ARCH_INIT(_fn) DECLARE_MTK_INITCALL(_fn, 1)
+#define MTK_PLAT_SETUP_0_INIT(_fn) DECLARE_MTK_INITCALL(_fn, 2)
+#define MTK_PLAT_SETUP_1_INIT(_fn) DECLARE_MTK_INITCALL(_fn, 3)
+#define MTK_PLAT_RUNTIME_INIT(_fn) DECLARE_MTK_INITCALL(_fn, 4)
+#define MTK_PLAT_BL33_DEFER_INIT(_fn) DECLARE_MTK_INITCALL(_fn, 5)
+
+#ifndef __ASSEMBLER__
+struct initcall {
+	const char *name;
+	int (*fn)(void);
+};
+
+enum {
+	INIT_CALL_TABLE(INIT_CALL_EXPAND_AS_ENUMERATION)
+	MTK_INIT_LVL_MAX
+};
+
+void mtk_init_one_level(unsigned int level);
+#endif
+
+#endif /* MTK_INIT_H */