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
  31 static 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
  52 void __init plat_mem_setup(void)
  53 {
  54         jz4740_reset_init();
  55         jz4740_detect_mem();
  56 }
  57
  58 const char *get_system_type(void)
  59 {
  60         return "JZ4740";
  61 }