LXR linux/arch/mips/jz4740/setup.c

   1/*
   2 *  Copyright (C) 2009-2010, Lars-Peter Clausen <lars@metafoo.de>
   3 *  Copyright (C) 2011, Maarten ter Huurne <maarten@treewalker.org>
   4 *  JZ4740 setup code
   5 *
   6 *  This program is free software; you can redistribute it and/or modify it
   7 *  under  the terms of the GNU General  Public License as published by the
   8 *  Free Software Foundation;  either version 2 of the License, or (at your
   9 *  option) any later version.
  10 *
  11 *  You should have received a copy of the GNU General Public License along
  12 *  with this program; if not, write to the Free Software Foundation, Inc.,
  13 *  675 Mass Ave, Cambridge, MA 02139, USA.
  14 *
  15 */
  16
  17#include <linux/init.h>
  18#include <linux/io.h>
  19#include <linux/kernel.h>
  20
  21#include <asm/bootinfo.h>
  22
  23#include <asm/mach-jz4740/base.h>
  24
  25#include "reset.h"
  26
  27
  28#define JZ4740_EMC_SDRAM_CTRL 0x80
  29
  30
  31static void __init jz4740_detect_mem(void)
  32{
  33        void __iomem *jz_emc_base;
  34        u32 ctrl, bus, bank, rows, cols;
  35        phys_t size;
  36
  37        jz_emc_base = ioremap(JZ4740_EMC_BASE_ADDR, 0x100);
  38        ctrl = readl(jz_emc_base + JZ4740_EMC_SDRAM_CTRL);
  39        bus = 2 - ((ctrl >> 31) & 1);
  40        bank = 1 + ((ctrl >> 19) & 1);
  41        cols = 8 + ((ctrl >> 26) & 7);
  42        rows = 11 + ((ctrl >> 20) & 3);
  43        printk(KERN_DEBUG
  44                "SDRAM preconfigured: bus:%u bank:%u rows:%u cols:%u\n",
  45                bus, bank, rows, cols);
  46        iounmap(jz_emc_base);
  47
  48        size = 1 << (bus + bank + cols + rows);
  49        add_memory_region(0, size, BOOT_MEM_RAM);
  50}
  51
  52void __init plat_mem_setup(void)
  53{
  54        jz4740_reset_init();
  55        jz4740_detect_mem();
  56}
  57
  58const char *get_system_type(void)
  59{
  60        return "JZ4740";
  61}
  62