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_fdt.h>
  12
  13 #include <asm/prom.h>
  14 #include <asm/fw/fw.h>
  15
  16 #include <asm/mips-boards/generic.h>
  17
  18 const char *get_system_type(void)
  19 {
  20         return "MIPS SEAD3";
  21 }
  22
  23 static uint32_t get_memsize_from_cmdline(void)
  24 {
  25         int memsize = 0;
  26         char *p = arcs_cmdline;
  27         char *s = "memsize=";
  28
  29         p = strstr(p, s);
  30         if (p) {
  31                 p += strlen(s);
  32                 memsize = memparse(p, NULL);
  33         }
  34
  35         return memsize;
  36 }
  37
  38 static uint32_t get_memsize_from_env(void)
  39 {
  40         int memsize = 0;
  41         char *p;
  42
  43         p = fw_getenv("memsize");
  44         if (p)
  45                 memsize = memparse(p, NULL);
  46
  47         return memsize;
  48 }
  49
  50 static uint32_t get_memsize(void)
  51 {
  52         uint32_t memsize;
  53
  54         memsize = get_memsize_from_cmdline();
  55         if (memsize)
  56                 return memsize;
  57
  58         return get_memsize_from_env();
  59 }
  60
  61 static void __init parse_memsize_param(void)
  62 {
  63         int offset;
  64         const uint64_t *prop_value;
  65         int prop_len;
  66         uint32_t memsize = get_memsize();
  67
  68         if (!memsize)
  69                 return;
  70
  71         offset = fdt_path_offset(__dtb_start, "/memory");
  72         if (offset > 0) {
  73                 uint64_t new_value;
  74                 /*
  75                  * reg contains 2 32-bits BE values, offset and size. We just
  76                  * want to replace the size value without affecting the offset
  77                  */
  78                 prop_value = fdt_getprop(__dtb_start, offset, "reg", &prop_len);
  79                 new_value = be64_to_cpu(*prop_value);
  80                 new_value =  (new_value & ~0xffffffffllu) | memsize;
  81                 fdt_setprop_inplace_u64(__dtb_start, offset, "reg", new_value);
  82         }
  83 }
  84
  85 void __init *plat_get_fdt(void)
  86 {
  87         return (void *)__dtb_start;
  88 }
  89
  90 void __init plat_mem_setup(void)
  91 {
  92         /* allow command line/bootloader env to override memory size in DT */
  93         parse_memsize_param();
  94
  95         /*
  96          * Load the builtin devicetree. This causes the chosen node to be
  97          * parsed resulting in our memory appearing
  98          */
  99         __dt_setup_arch(__dtb_start);
 100 }
 101
 102 void __init device_tree_init(void)
 103 {
 104         if (!initial_boot_params)
 105                 return;
 106
 107         unflatten_and_copy_device_tree();
 108 }