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