device_tree.c

   1 /*
   2  * Functions to help device tree manipulation using libfdt.
   3  * It also provides functions to read entries from device tree proc
   4  * interface.
   5  *
   6  * Copyright 2008 IBM Corporation.
   7  * Authors: Jerone Young <jyoung5@us.ibm.com>
   8  *          Hollis Blanchard <hollisb@us.ibm.com>
   9  *
  10  * This work is licensed under the GNU GPL license version 2 or later.
  11  *
  12  */
  13
  14 #include <stdio.h>
  15 #include <sys/types.h>
  16 #include <sys/stat.h>
  17 #include <fcntl.h>
  18 #include <unistd.h>
  19 #include <stdlib.h>
  20
  21 #include "config.h"
  22 #include "qemu-common.h"
  23 #include "device_tree.h"
  24 #include "hw/loader.h"
  25
  26 #include <libfdt.h>
  27
  28 #define FDT_MAX_SIZE  0x10000
  29
  30 void *create_device_tree(int *sizep)
  31 {
  32     void *fdt;
  33     int ret;
  34
  35     *sizep = FDT_MAX_SIZE;
  36     fdt = g_malloc0(FDT_MAX_SIZE);
  37     ret = fdt_create(fdt, FDT_MAX_SIZE);
  38     if (ret < 0) {
  39         goto fail;
  40     }
  41     ret = fdt_begin_node(fdt, "");
  42     if (ret < 0) {
  43         goto fail;
  44     }
  45     ret = fdt_end_node(fdt);
  46     if (ret < 0) {
  47         goto fail;
  48     }
  49     ret = fdt_finish(fdt);
  50     if (ret < 0) {
  51         goto fail;
  52     }
  53     ret = fdt_open_into(fdt, fdt, *sizep);
  54     if (ret) {
  55         fprintf(stderr, "Unable to copy device tree in memory\n");
  56         exit(1);
  57     }
  58
  59     return fdt;
  60 fail:
  61     fprintf(stderr, "%s Couldn't create dt: %s\n", __func__, fdt_strerror(ret));
  62     exit(1);
  63 }
  64
  65 void *load_device_tree(const char *filename_path, int *sizep)
  66 {
  67     int dt_size;
  68     int dt_file_load_size;
  69     int ret;
  70     void *fdt = NULL;
  71
  72     *sizep = 0;
  73     dt_size = get_image_size(filename_path);
  74     if (dt_size < 0) {
  75         printf("Unable to get size of device tree file '%s'\n",
  76             filename_path);
  77         goto fail;
  78     }
  79
  80     /* Expand to 2x size to give enough room for manipulation.  */
  81     dt_size += 10000;
  82     dt_size *= 2;
  83     /* First allocate space in qemu for device tree */
  84     fdt = g_malloc0(dt_size);
  85
  86     dt_file_load_size = load_image(filename_path, fdt);
  87     if (dt_file_load_size < 0) {
  88         printf("Unable to open device tree file '%s'\n",
  89                filename_path);
  90         goto fail;
  91     }
  92
  93     ret = fdt_open_into(fdt, fdt, dt_size);
  94     if (ret) {
  95         printf("Unable to copy device tree in memory\n");
  96         goto fail;
  97     }
  98
  99     /* Check sanity of device tree */
 100     if (fdt_check_header(fdt)) {
 101         printf ("Device tree file loaded into memory is invalid: %s\n",
 102             filename_path);
 103         goto fail;
 104     }
 105     *sizep = dt_size;
 106     return fdt;
 107
 108 fail:
 109     g_free(fdt);
 110     return NULL;
 111 }
 112
 113 static int findnode_nofail(void *fdt, const char *node_path)
 114 {
 115     int offset;
 116
 117     offset = fdt_path_offset(fdt, node_path);
 118     if (offset < 0) {
 119         fprintf(stderr, "%s Couldn't find node %s: %s\n", __func__, node_path,
 120                 fdt_strerror(offset));
 121         exit(1);
 122     }
 123
 124     return offset;
 125 }
 126
 127 int qemu_devtree_setprop(void *fdt, const char *node_path,
 128                          const char *property, void *val_array, int size)
 129 {
 130     int r;
 131
 132     r = fdt_setprop(fdt, findnode_nofail(fdt, node_path), property, val_array, size);
 133     if (r < 0) {
 134         fprintf(stderr, "%s: Couldn't set %s/%s: %s\n", __func__, node_path,
 135                 property, fdt_strerror(r));
 136         exit(1);
 137     }
 138
 139     return r;
 140 }
 141
 142 int qemu_devtree_setprop_cell(void *fdt, const char *node_path,
 143                               const char *property, uint32_t val)
 144 {
 145     int r;
 146
 147     r = fdt_setprop_cell(fdt, findnode_nofail(fdt, node_path), property, val);
 148     if (r < 0) {
 149         fprintf(stderr, "%s: Couldn't set %s/%s = %#08x: %s\n", __func__,
 150                 node_path, property, val, fdt_strerror(r));
 151         exit(1);
 152     }
 153
 154     return r;
 155 }
 156
 157 int qemu_devtree_setprop_u64(void *fdt, const char *node_path,
 158                              const char *property, uint64_t val)
 159 {
 160     val = cpu_to_be64(val);
 161     return qemu_devtree_setprop(fdt, node_path, property, &val, sizeof(val));
 162 }
 163
 164 int qemu_devtree_setprop_string(void *fdt, const char *node_path,
 165                                 const char *property, const char *string)
 166 {
 167     int r;
 168
 169     r = fdt_setprop_string(fdt, findnode_nofail(fdt, node_path), property, string);
 170     if (r < 0) {
 171         fprintf(stderr, "%s: Couldn't set %s/%s = %s: %s\n", __func__,
 172                 node_path, property, string, fdt_strerror(r));
 173         exit(1);
 174     }
 175
 176     return r;
 177 }
 178
 179 uint32_t qemu_devtree_get_phandle(void *fdt, const char *path)
 180 {
 181     uint32_t r;
 182
 183     r = fdt_get_phandle(fdt, findnode_nofail(fdt, path));
 184     if (r <= 0) {
 185         fprintf(stderr, "%s: Couldn't get phandle for %s: %s\n", __func__,
 186                 path, fdt_strerror(r));
 187         exit(1);
 188     }
 189
 190     return r;
 191 }
 192
 193 int qemu_devtree_setprop_phandle(void *fdt, const char *node_path,
 194                                  const char *property,
 195                                  const char *target_node_path)
 196 {
 197     uint32_t phandle = qemu_devtree_get_phandle(fdt, target_node_path);
 198     return qemu_devtree_setprop_cell(fdt, node_path, property, phandle);
 199 }
 200
 201 uint32_t qemu_devtree_alloc_phandle(void *fdt)
 202 {
 203     static int phandle = 0x8000;
 204
 205     return phandle++;
 206 }
 207
 208 int qemu_devtree_nop_node(void *fdt, const char *node_path)
 209 {
 210     int r;
 211
 212     r = fdt_nop_node(fdt, findnode_nofail(fdt, node_path));
 213     if (r < 0) {
 214         fprintf(stderr, "%s: Couldn't nop node %s: %s\n", __func__, node_path,
 215                 fdt_strerror(r));
 216         exit(1);
 217     }
 218
 219     return r;
 220 }
 221
 222 int qemu_devtree_add_subnode(void *fdt, const char *name)
 223 {
 224     char *dupname = g_strdup(name);
 225     char *basename = strrchr(dupname, '/');
 226     int retval;
 227     int parent = 0;
 228
 229     if (!basename) {
 230         g_free(dupname);
 231         return -1;
 232     }
 233
 234     basename[0] = '\0';
 235     basename++;
 236
 237     if (dupname[0]) {
 238         parent = findnode_nofail(fdt, dupname);
 239     }
 240
 241     retval = fdt_add_subnode(fdt, parent, basename);
 242 #if 0
 243     if (retval < 0) {
 244         fprintf(stderr, "FDT: Failed to create subnode %s: %s\n", name,
 245                 fdt_strerror(retval));
 246         exit(1);
 247     }
 248 #endif
 249
 250     g_free(dupname);
 251     return retval;
 252 }