ARM: Add Support for Marvell Pantheon Familiy SoCs

Pantheon Family processors are highly integrated SoCs
based on Sheeva_88SV331x-v5 PJ1 cpu core.
Ref:
http://www.marvell.com/products/processors/communications/marvell_pantheon_910_920_pb.pdf

SoC versions Supported:
1) PANTHEON920          (TD)
2) PANTHEON910          (TTC)

Signed-off-by: Lei Wen <leiwen@marvell.com>
diff --git a/arch/arm/cpu/arm926ejs/pantheon/dram.c b/arch/arm/cpu/arm926ejs/pantheon/dram.c
new file mode 100644
index 0000000..bbca7ee
--- /dev/null
+++ b/arch/arm/cpu/arm926ejs/pantheon/dram.c
@@ -0,0 +1,132 @@
+/*
+ * (C) Copyright 2011
+ * Marvell Semiconductor <www.marvell.com>
+ * Written-by: Lei Wen <leiwen@marvell.com>,
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301 USA
+ */
+
+#include <common.h>
+#include <asm/arch/pantheon.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/*
+ * Pantheon DRAM controller supports upto 8 banks
+ * for chip select 0 and 1
+ */
+
+/*
+ * DDR Memory Control Registers
+ * Refer Datasheet 4.4
+ */
+struct panthddr_map_registers {
+	u32	cs;	/* Memory Address Map Register -CS */
+	u32	pad[3];
+};
+
+struct panthddr_registers {
+	u8	pad[0x100 - 0x000];
+	struct panthddr_map_registers mmap[2];
+};
+
+/*
+ * panth_sdram_base - reads SDRAM Base Address Register
+ */
+u32 panth_sdram_base(int chip_sel)
+{
+	struct panthddr_registers *ddr_regs =
+		(struct panthddr_registers *)PANTHEON_DRAM_BASE;
+	u32 result = 0;
+	u32 CS_valid = 0x01 & readl(&ddr_regs->mmap[chip_sel].cs);
+
+	if (!CS_valid)
+		return 0;
+
+	result = readl(&ddr_regs->mmap[chip_sel].cs) & 0xFF800000;
+	return result;
+}
+
+/*
+ * panth_sdram_size - reads SDRAM size
+ */
+u32 panth_sdram_size(int chip_sel)
+{
+	struct panthddr_registers *ddr_regs =
+		(struct panthddr_registers *)PANTHEON_DRAM_BASE;
+	u32 result = 0;
+	u32 CS_valid = 0x01 & readl(&ddr_regs->mmap[chip_sel].cs);
+
+	if (!CS_valid)
+		return 0;
+
+	result = readl(&ddr_regs->mmap[chip_sel].cs);
+	result = (result >> 16) & 0xF;
+	if (result < 0x7) {
+		printf("Unknown DRAM Size\n");
+		return -1;
+	} else {
+		return ((0x8 << (result - 0x7)) * 1024 * 1024);
+	}
+}
+
+#ifndef CONFIG_SYS_BOARD_DRAM_INIT
+int dram_init(void)
+{
+	int i;
+
+	gd->ram_size = 0;
+	for (i = 0; i < CONFIG_NR_DRAM_BANKS; i++) {
+		gd->bd->bi_dram[i].start = panth_sdram_base(i);
+		gd->bd->bi_dram[i].size = panth_sdram_size(i);
+		/*
+		 * It is assumed that all memory banks are consecutive
+		 * and without gaps.
+		 * If the gap is found, ram_size will be reported for
+		 * consecutive memory only
+		 */
+		if (gd->bd->bi_dram[i].start != gd->ram_size)
+			break;
+
+		gd->ram_size += gd->bd->bi_dram[i].size;
+
+	}
+
+	for (; i < CONFIG_NR_DRAM_BANKS; i++) {
+		/*
+		 * If above loop terminated prematurely, we need to set
+		 * remaining banks' start address & size as 0. Otherwise other
+		 * u-boot functions and Linux kernel gets wrong values which
+		 * could result in crash
+		 */
+		gd->bd->bi_dram[i].start = 0;
+		gd->bd->bi_dram[i].size = 0;
+	}
+	return 0;
+}
+
+/*
+ * If this function is not defined here,
+ * board.c alters dram bank zero configuration defined above.
+ */
+void dram_init_banksize(void)
+{
+	dram_init();
+}
+#endif /* CONFIG_SYS_BOARD_DRAM_INIT */