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
  36 static 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
  57 void __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
  69 void __init device_tree_init(void)
  70 {
  71         if (!initial_boot_params)
  72                 return;
  73
  74         unflatten_and_copy_device_tree();
  75 }
  76
  77 static int __init populate_machine(void)
  78 {
  79         of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
  80         return 0;
  81 }
  82 arch_initcall(populate_machine);
  83
  84 const char *get_system_type(void)
  85 {
  86         return "JZ4740";
  87 }
  88
  89 void __init arch_init_irq(void)
  90 {
  91         irqchip_init();
  92 }