setup.c

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/*
 *  Copyright (C) 2009-2010, Lars-Peter Clausen <[email protected]>
 *  Copyright (C) 2011, Maarten ter Huurne <[email protected]>
 *  JZ4740 setup code
 *
 *  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.
 *
 *  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.,
 *  675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

#include <linux/init.h>
#include <linux/io.h>
#include <linux/kernel.h>

#include <asm/bootinfo.h>

#include <asm/mach-jz4740/base.h>

#include "reset.h"


#define JZ4740_EMC_SDRAM_CTRL 0x80


static void __init jz4740_detect_mem(void)
{
    void __iomem *jz_emc_base;
    u32 ctrl, bus, bank, rows, cols;
    phys_t size;

    jz_emc_base = ioremap(JZ4740_EMC_BASE_ADDR, 0x100);
    ctrl = readl(jz_emc_base + JZ4740_EMC_SDRAM_CTRL);
    bus = 2 - ((ctrl >> 31) & 1);
    bank = 1 + ((ctrl >> 19) & 1);
    cols = 8 + ((ctrl >> 26) & 7);
    rows = 11 + ((ctrl >> 20) & 3);
    printk(KERN_DEBUG
        "SDRAM preconfigured: bus:%u bank:%u rows:%u cols:%u\n",
        bus, bank, rows, cols);
    iounmap(jz_emc_base);

    size = 1 << (bus + bank + cols + rows);
    add_memory_region(0, size, BOOT_MEM_RAM);
}

void __init plat_mem_setup(void)
{
    jz4740_reset_init();
    jz4740_detect_mem();
}

const char *get_system_type(void)
{
    return "JZ4740";
}