snapdragon: Add DRAM detection & FDT fixup

Fixup the Linux FDT with the detection of onboard DRAM as
provided by SBL (Secondary boot loader) by reading
the shared-memory region.

Signed-off-by: Ramon Fried <ramon.fried@gmail.com>

arch/arm/mach-snapdragon/Makefile

@@ -9,3 +9,4 @@ obj-$(CONFIG_TARGET_DRAGONBOARD410C) += sysmap-apq8016.o
 obj-$(CONFIG_TARGET_DRAGONBOARD410C) += pinctrl-apq8016.o
 obj-$(CONFIG_TARGET_DRAGONBOARD410C) += pinctrl-snapdragon.o
 obj-y += clock-snapdragon.o
+obj-y += dram.o

arch/arm/mach-snapdragon/dram.c

@@ -0,0 +1,98 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Onboard memory detection for Snapdragon boards
+ *
+ * (C) Copyright 2018 Ramon Fried <ramon.fried@gmail.com>
+ *
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <smem.h>
+#include <fdt_support.h>
+#include <asm/arch/dram.h>
+
+#define SMEM_USABLE_RAM_PARTITION_TABLE 402
+#define RAM_PART_NAME_LENGTH            16
+#define RAM_NUM_PART_ENTRIES            32
+#define CATEGORY_SDRAM 0x0E
+#define TYPE_SYSMEM 0x01
+
+struct smem_ram_ptable_hdr {
+	u32 magic[2];
+	u32 version;
+	u32 reserved;
+	u32 len;
+} __attribute__ ((__packed__));
+
+struct smem_ram_ptn {
+	char name[RAM_PART_NAME_LENGTH];
+	u64 start;
+	u64 size;
+	u32 attr;
+	u32 category;
+	u32 domain;
+	u32 type;
+	u32 num_partitions;
+	u32 reserved[3];
+} __attribute__ ((__packed__));
+
+struct smem_ram_ptable {
+	struct smem_ram_ptable_hdr hdr;
+	u32 reserved;     /* Added for 8 bytes alignment of header */
+	struct smem_ram_ptn parts[RAM_NUM_PART_ENTRIES];
+} __attribute__ ((__packed__));
+
+#ifndef MEMORY_BANKS_MAX
+#define MEMORY_BANKS_MAX 4
+#endif
+
+int msm_fixup_memory(void *blob)
+{
+	u64 bank_start[MEMORY_BANKS_MAX];
+	u64 bank_size[MEMORY_BANKS_MAX];
+	size_t size;
+	int i;
+	int count = 0;
+	struct udevice *smem;
+	int ret;
+	struct smem_ram_ptable *ram_ptable;
+	struct smem_ram_ptn *p;
+
+	ret = uclass_get_device_by_name(UCLASS_SMEM, "smem", &smem);
+	if (ret < 0) {
+		printf("Failed to find SMEM node. Check device tree\n");
+		return 0;
+	}
+
+	ram_ptable = smem_get(smem, -1, SMEM_USABLE_RAM_PARTITION_TABLE, &size);
+
+	if (!ram_ptable) {
+		printf("Failed to find SMEM partition.\n");
+		return -ENODEV;
+	}
+
+	/* Check validy of RAM */
+	for (i = 0; i < RAM_NUM_PART_ENTRIES; i++) {
+		p = &ram_ptable->parts[i];
+		if (p->category == CATEGORY_SDRAM && p->type == TYPE_SYSMEM) {
+			bank_start[count] = p->start;
+			bank_size[count] = p->size;
+			debug("Detected memory bank %u: start: 0x%llx size: 0x%llx\n",
+					count, p->start, p->size);
+			count++;
+		}
+	}
+
+	if (!count) {
+		printf("Failed to detect any memory bank\n");
+		return -ENODEV;
+	}
+
+	ret = fdt_fixup_memory_banks(blob, bank_start, bank_size, count);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+

arch/arm/mach-snapdragon/include/mach/dram.h

@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Snapdragon DRAM
+ * Copyright (C) 2018 Ramon Fried <ramon.fried@gmail.com>
+ */
+
+#ifndef DRAM_H
+#define DRAM_H
+
+int msm_fixup_memory(void *blob);
+
+#endif