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/irqchip.h>
  20#include <linux/kernel.h>
  21#include <linux/libfdt.h>
  22#include <linux/of_fdt.h>
  23#include <linux/of_platform.h>
  24
  25#include <asm/bootinfo.h>
  26#include <asm/prom.h>
  27
  28#include <asm/mach-jz4740/base.h>
  29
  30#include "reset.h"
  31
  32
  33#define JZ4740_EMC_SDRAM_CTRL 0x80
  34
  35
  36static void __init jz4740_detect_mem(void)
  37{
  38        void __iomem *jz_emc_base;
  39        u32 ctrl, bus, bank, rows, cols;
  40        phys_addr_t size;
  41
  42        jz_emc_base = ioremap(JZ4740_EMC_BASE_ADDR, 0x100);
  43        ctrl = readl(jz_emc_base + JZ4740_EMC_SDRAM_CTRL);
  44        bus = 2 - ((ctrl >> 31) & 1);
  45        bank = 1 + ((ctrl >> 19) & 1);
  46        cols = 8 + ((ctrl >> 26) & 7);
  47        rows = 11 + ((ctrl >> 20) & 3);
  48        printk(KERN_DEBUG
  49                "SDRAM preconfigured: bus:%u bank:%u rows:%u cols:%u\n",
  50                bus, bank, rows, cols);
  51        iounmap(jz_emc_base);
  52
  53        size = 1 << (bus + bank + cols + rows);
  54        add_memory_region(0, size, BOOT_MEM_RAM);
  55}
  56
  57void __init plat_mem_setup(void)
  58{
  59        int offset;
  60
  61        jz4740_reset_init();
  62        __dt_setup_arch(__dtb_start);
  63
  64        offset = fdt_path_offset(__dtb_start, "/memory");
  65        if (offset < 0)
  66                jz4740_detect_mem();
  67}
  68
  69void __init device_tree_init(void)
  70{
  71        if (!initial_boot_params)
  72                return;
  73
  74        unflatten_and_copy_device_tree();
  75}
  76
  77static int __init populate_machine(void)
  78{
  79        of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
  80        return 0;
  81}
  82arch_initcall(populate_machine);
  83
  84const char *get_system_type(void)
  85{
  86        if (config_enabled(CONFIG_MACH_JZ4780))
  87                return "JZ4780";
  88
  89        return "JZ4740";
  90}
  91
  92void __init arch_init_irq(void)
  93{
  94        irqchip_init();
  95}
  96