feat(mt8188): add EMI MPU basic drivers

EMI MPU stands for external memory interface memory protect unit.
MT8188 supports 32 regions and 16 domains.

Change-Id: I9bbeb355665401cc71dda6db22157d9d751570d1
diff --git a/plat/mediatek/drivers/emi_mpu/emi_mpu_common.c b/plat/mediatek/drivers/emi_mpu/emi_mpu_common.c
new file mode 100644
index 0000000..27b2b07
--- /dev/null
+++ b/plat/mediatek/drivers/emi_mpu/emi_mpu_common.c
@@ -0,0 +1,123 @@
+/*
+ * Copyright (c) 2022, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <string.h>
+#include <common/debug.h>
+#include <lib/mmio.h>
+#include <emi_mpu.h>
+#include <lib/mtk_init/mtk_init.h>
+
+#if ENABLE_EMI_MPU_SW_LOCK
+static unsigned char region_lock_state[EMI_MPU_REGION_NUM];
+#endif
+
+#define EMI_MPU_START_MASK		(0x00FFFFFF)
+#define EMI_MPU_END_MASK		(0x00FFFFFF)
+#define EMI_MPU_APC_SW_LOCK_MASK	(0x00FFFFFF)
+#define EMI_MPU_APC_HW_LOCK_MASK	(0x80FFFFFF)
+
+static int _emi_mpu_set_protection(unsigned int start, unsigned int end,
+					unsigned int apc)
+{
+	unsigned int dgroup;
+	unsigned int region;
+
+	region = (start >> 24) & 0xFF;
+	start &= EMI_MPU_START_MASK;
+	dgroup = (end >> 24) & 0xFF;
+	end &= EMI_MPU_END_MASK;
+
+	if  ((region >= EMI_MPU_REGION_NUM) || (dgroup > EMI_MPU_DGROUP_NUM)) {
+		WARN("invalid region, domain\n");
+		return -1;
+	}
+
+#if ENABLE_EMI_MPU_SW_LOCK
+	if (region_lock_state[region] == 1) {
+		WARN("invalid region\n");
+		return -1;
+	}
+
+	if ((dgroup == 0) && ((apc >> 31) & 0x1)) {
+		region_lock_state[region] = 1;
+	}
+
+	apc &= EMI_MPU_APC_SW_LOCK_MASK;
+#else
+	apc &= EMI_MPU_APC_HW_LOCK_MASK;
+#endif
+
+	if ((start >= DRAM_OFFSET) && (end >= start)) {
+		start -= DRAM_OFFSET;
+		end -= DRAM_OFFSET;
+	} else {
+		WARN("invalid range\n");
+		return -1;
+	}
+
+	mmio_write_32(EMI_MPU_SA(region), start);
+	mmio_write_32(EMI_MPU_EA(region), end);
+	mmio_write_32(EMI_MPU_APC(region, dgroup), apc);
+
+#if defined(SUB_EMI_MPU_BASE)
+	mmio_write_32(SUB_EMI_MPU_SA(region), start);
+	mmio_write_32(SUB_EMI_MPU_EA(region), end);
+	mmio_write_32(SUB_EMI_MPU_APC(region, dgroup), apc);
+#endif
+	return 0;
+}
+
+static void dump_emi_mpu_regions(void)
+{
+	int region, i;
+
+	/* Only dump 8 regions(max: EMI_MPU_REGION_NUM --> 32) */
+	for (region = 0; region < 8; ++region) {
+		INFO("region %d:\n", region);
+		INFO("\tsa: 0x%x, ea: 0x%x\n",
+		     mmio_read_32(EMI_MPU_SA(region)), mmio_read_32(EMI_MPU_EA(region)));
+
+		for (i = 0; i < EMI_MPU_DGROUP_NUM; ++i) {
+			INFO("\tapc%d: 0x%x\n", i, mmio_read_32(EMI_MPU_APC(region, i)));
+		}
+	}
+}
+
+int emi_mpu_set_protection(struct emi_region_info_t *region_info)
+{
+	unsigned int start, end;
+	int i;
+
+	if (region_info->region >= EMI_MPU_REGION_NUM) {
+		WARN("invalid region\n");
+		return -1;
+	}
+
+	start = (unsigned int)(region_info->start >> EMI_MPU_ALIGN_BITS) |
+		(region_info->region << 24);
+
+	for (i = EMI_MPU_DGROUP_NUM - 1; i >= 0; i--) {
+		end = (unsigned int)(region_info->end >> EMI_MPU_ALIGN_BITS) | (i << 24);
+
+		if (_emi_mpu_set_protection(start, end, region_info->apc[i]) < 0) {
+			WARN("Failed to set emi mpu protection(%d, %d, %d)\n",
+			     start, end, region_info->apc[i]);
+		}
+	}
+
+	return 0;
+}
+
+int emi_mpu_init(void)
+{
+	INFO("[%s] emi mpu initialization\n", __func__);
+
+	set_emi_mpu_regions();
+	dump_emi_mpu_regions();
+
+	return 0;
+}
+MTK_PLAT_SETUP_0_INIT(emi_mpu_init);