diff options
Diffstat (limited to 'arch/arm/cpu/arm926ejs/pantheon/dram.c')
-rw-r--r-- | arch/arm/cpu/arm926ejs/pantheon/dram.c | 132 |
1 files changed, 132 insertions, 0 deletions
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 */ |