arch/powerpc/boot/libfdt-wrapper.c

   1 /*
   2  * This file does the necessary interface mapping between the bootwrapper
   3  * device tree operations and the interface provided by shared source
   4  * files flatdevicetree.[ch].
   5  *
   6  * Copyright 2007 David Gibson, IBM Corporation.
   7  *
   8  * This library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License as
  10  * published by the Free Software Foundation; either version 2 of the
  11  * License, or (at your option) any later version.
  12  *
  13  * This library is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this library; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  21  * 02110-1301 USA
  22  */
  23
  24 #include <stddef.h>
  25 #include <stdio.h>
  26 #include <page.h>
  27 #include <libfdt.h>
  28 #include "ops.h"
  29
  30 #define DEBUG   0
  31 #define BAD_ERROR(err)  (((err) < 0) \
  32                          && ((err) != -FDT_ERR_NOTFOUND) \
  33                          && ((err) != -FDT_ERR_EXISTS))
  34
  35 #define check_err(err) \
  36         ({ \
  37                 if (BAD_ERROR(err) || ((err < 0) && DEBUG)) \
  38                         printf("%s():%d  %s\n\r", __func__, __LINE__, \
  39                                fdt_strerror(err)); \
  40                 if (BAD_ERROR(err)) \
  41                         exit(); \
  42                 (err < 0) ? -1 : 0; \
  43         })
  44
  45 #define offset_devp(off)        \
  46         ({ \
  47                 int _offset = (off); \
  48                 check_err(_offset) ? NULL : (void *)(_offset+1); \
  49         })
  50
  51 #define devp_offset_find(devp)  (((int)(devp))-1)
  52 #define devp_offset(devp)       (devp ? ((int)(devp))-1 : 0)
  53
  54 static void *fdt;
  55 static void *buf; /* = NULL */
  56
  57 #define EXPAND_GRANULARITY      1024
  58
  59 static void expand_buf(int minexpand)
  60 {
  61         int size = fdt_totalsize(fdt);
  62         int rc;
  63
  64         size = _ALIGN(size + minexpand, EXPAND_GRANULARITY);
  65         buf = platform_ops.realloc(buf, size);
  66         if (!buf)
  67                 fatal("Couldn't find %d bytes to expand device tree\n\r", size);
  68         rc = fdt_open_into(fdt, buf, size);
  69         if (rc != 0)
  70                 fatal("Couldn't expand fdt into new buffer: %s\n\r",
  71                       fdt_strerror(rc));
  72
  73         fdt = buf;
  74 }
  75
  76 static void *fdt_wrapper_finddevice(const char *path)
  77 {
  78         return offset_devp(fdt_path_offset(fdt, path));
  79 }
  80
  81 static int fdt_wrapper_getprop(const void *devp, const char *name,
  82                                void *buf, const int buflen)
  83 {
  84         const void *p;
  85         int len;
  86
  87         p = fdt_getprop(fdt, devp_offset(devp), name, &len);
  88         if (!p)
  89                 return check_err(len);
  90         memcpy(buf, p, min(len, buflen));
  91         return len;
  92 }
  93
  94 static int fdt_wrapper_setprop(const void *devp, const char *name,
  95                                const void *buf, const int len)
  96 {
  97         int rc;
  98
  99         rc = fdt_setprop(fdt, devp_offset(devp), name, buf, len);
 100         if (rc == -FDT_ERR_NOSPACE) {
 101                 expand_buf(len + 16);
 102                 rc = fdt_setprop(fdt, devp_offset(devp), name, buf, len);
 103         }
 104
 105         return check_err(rc);
 106 }
 107
 108 static int fdt_wrapper_del_node(const void *devp)
 109 {
 110         return fdt_del_node(fdt, devp_offset(devp));
 111 }
 112
 113 static void *fdt_wrapper_get_parent(const void *devp)
 114 {
 115         return offset_devp(fdt_parent_offset(fdt, devp_offset(devp)));
 116 }
 117
 118 static void *fdt_wrapper_create_node(const void *devp, const char *name)
 119 {
 120         int offset;
 121
 122         offset = fdt_add_subnode(fdt, devp_offset(devp), name);
 123         if (offset == -FDT_ERR_NOSPACE) {
 124                 expand_buf(strlen(name) + 16);
 125                 offset = fdt_add_subnode(fdt, devp_offset(devp), name);
 126         }
 127
 128         return offset_devp(offset);
 129 }
 130
 131 static void *fdt_wrapper_find_node_by_prop_value(const void *prev,
 132                                                  const char *name,
 133                                                  const char *val,
 134                                                  int len)
 135 {
 136         int offset = fdt_node_offset_by_prop_value(fdt, devp_offset_find(prev),
 137                                                    name, val, len);
 138         return offset_devp(offset);
 139 }
 140
 141 static void *fdt_wrapper_find_node_by_compatible(const void *prev,
 142                                                  const char *val)
 143 {
 144         int offset = fdt_node_offset_by_compatible(fdt, devp_offset_find(prev),
 145                                                    val);
 146         return offset_devp(offset);
 147 }
 148
 149 static char *fdt_wrapper_get_path(const void *devp, char *buf, int len)
 150 {
 151         int rc;
 152
 153         rc = fdt_get_path(fdt, devp_offset(devp), buf, len);
 154         if (check_err(rc))
 155                 return NULL;
 156         return buf;
 157 }
 158
 159 static unsigned long fdt_wrapper_finalize(void)
 160 {
 161         int rc;
 162
 163         rc = fdt_pack(fdt);
 164         if (rc != 0)
 165                 fatal("Couldn't pack flat tree: %s\n\r",
 166                       fdt_strerror(rc));
 167         return (unsigned long)fdt;
 168 }
 169
 170 void fdt_init(void *blob)
 171 {
 172         int err;
 173         int bufsize;
 174
 175         dt_ops.finddevice = fdt_wrapper_finddevice;
 176         dt_ops.getprop = fdt_wrapper_getprop;
 177         dt_ops.setprop = fdt_wrapper_setprop;
 178         dt_ops.get_parent = fdt_wrapper_get_parent;
 179         dt_ops.create_node = fdt_wrapper_create_node;
 180         dt_ops.find_node_by_prop_value = fdt_wrapper_find_node_by_prop_value;
 181         dt_ops.find_node_by_compatible = fdt_wrapper_find_node_by_compatible;
 182         dt_ops.del_node = fdt_wrapper_del_node;
 183         dt_ops.get_path = fdt_wrapper_get_path;
 184         dt_ops.finalize = fdt_wrapper_finalize;
 185
 186         /* Make sure the dt blob is the right version and so forth */
 187         fdt = blob;
 188         bufsize = fdt_totalsize(fdt) + 4;
 189         buf = malloc(bufsize);
 190         if(!buf)
 191                 fatal("malloc failed. can't relocate the device tree\n\r");
 192
 193         err = fdt_open_into(fdt, buf, bufsize);
 194
 195         if (err != 0)
 196                 fatal("fdt_init(): %s\n\r", fdt_strerror(err));
 197
 198         fdt = buf;
 199 }