arch/mips/mti-sead3/sead3-setup.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 2012 MIPS Technologies, Inc.  All rights reserved.
   7  * Copyright (C) 2013 Imagination Technologies Ltd.
   8  */
   9 #include <linux/init.h>
  10 #include <linux/libfdt.h>
  11 #include <linux/of_platform.h>
  12 #include <linux/of_fdt.h>
  13
  14 #include <asm/prom.h>
  15 #include <asm/fw/fw.h>
  16
  17 #include <asm/mips-boards/generic.h>
  18
  19 const char *get_system_type(void)
  20 {
  21         return "MIPS SEAD3";
  22 }
  23
  24 static uint32_t get_memsize_from_cmdline(void)
  25 {
  26         int memsize = 0;
  27         char *p = arcs_cmdline;
  28         char *s = "memsize=";
  29
  30         p = strstr(p, s);
  31         if (p) {
  32                 p += strlen(s);
  33                 memsize = memparse(p, NULL);
  34         }
  35
  36         return memsize;
  37 }
  38
  39 static uint32_t get_memsize_from_env(void)
  40 {
  41         int memsize = 0;
  42         char *p;
  43
  44         p = fw_getenv("memsize");
  45         if (p)
  46                 memsize = memparse(p, NULL);
  47
  48         return memsize;
  49 }
  50
  51 static uint32_t get_memsize(void)
  52 {
  53         uint32_t memsize;
  54
  55         memsize = get_memsize_from_cmdline();
  56         if (memsize)
  57                 return memsize;
  58
  59         return get_memsize_from_env();
  60 }
  61
  62 static void __init parse_memsize_param(void)
  63 {
  64         int offset;
  65         const uint64_t *prop_value;
  66         int prop_len;
  67         uint32_t memsize = get_memsize();
  68
  69         if (!memsize)
  70                 return;
  71
  72         offset = fdt_path_offset(&__dtb_start, "/memory");
  73         if (offset > 0) {
  74                 uint64_t new_value;
  75                 /*
  76                  * reg contains 2 32-bits BE values, offset and size. We just
  77                  * want to replace the size value without affecting the offset
  78                  */
  79                 prop_value = fdt_getprop(&__dtb_start, offset, "reg", &prop_len);
  80                 new_value = be64_to_cpu(*prop_value);
  81                 new_value =  (new_value & ~0xffffffffllu) | memsize;
  82                 fdt_setprop_inplace_u64(&__dtb_start, offset, "reg", new_value);
  83         }
  84 }
  85
  86 void __init plat_mem_setup(void)
  87 {
  88         /* allow command line/bootloader env to override memory size in DT */
  89         parse_memsize_param();
  90
  91         /*
  92          * Load the builtin devicetree. This causes the chosen node to be
  93          * parsed resulting in our memory appearing
  94          */
  95         __dt_setup_arch(&__dtb_start);
  96 }
  97
  98 void __init device_tree_init(void)
  99 {
 100         if (!initial_boot_params)
 101                 return;
 102
 103         unflatten_and_copy_device_tree();
 104 }
 105
 106 static int __init customize_machine(void)
 107 {
 108         of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
 109         return 0;
 110 }
 111 arch_initcall(customize_machine);