1 /* 2 * Copyright (c) 2011 The Chromium OS Authors. 3 * See file CREDITS for list of people who contributed to this 4 * project. 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License as 8 * published by the Free Software Foundation; either version 2 of 9 * the License, or (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, write to the Free Software 18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, 19 * MA 02111-1307 USA 20 */ 21 22 #include <common.h> 23 #include <serial.h> 24 #include <libfdt.h> 25 #include <fdtdec.h> 26 27 DECLARE_GLOBAL_DATA_PTR; 28 29 /* 30 * Here are the type we know about. One day we might allow drivers to 31 * register. For now we just put them here. The COMPAT macro allows us to 32 * turn this into a sparse list later, and keeps the ID with the name. 33 */ 34 #define COMPAT(id, name) name 35 static const char * const compat_names[COMPAT_COUNT] = { 36 COMPAT(UNKNOWN, "<none>"), 37 }; 38 39 const char *fdtdec_get_compatible(enum fdt_compat_id id) 40 { 41 /* We allow reading of the 'unknown' ID for testing purposes */ 42 assert(id >= 0 && id < COMPAT_COUNT); 43 return compat_names[id]; 44 } 45 46 /** 47 * Look in the FDT for an alias with the given name and return its node. 48 * 49 * @param blob FDT blob 50 * @param name alias name to look up 51 * @return node offset if found, or an error code < 0 otherwise 52 */ 53 static int find_alias_node(const void *blob, const char *name) 54 { 55 const char *path; 56 int alias_node; 57 58 debug("find_alias_node: %s\n", name); 59 alias_node = fdt_path_offset(blob, "/aliases"); 60 if (alias_node < 0) 61 return alias_node; 62 path = fdt_getprop(blob, alias_node, name, NULL); 63 if (!path) 64 return -FDT_ERR_NOTFOUND; 65 return fdt_path_offset(blob, path); 66 } 67 68 fdt_addr_t fdtdec_get_addr(const void *blob, int node, 69 const char *prop_name) 70 { 71 const fdt_addr_t *cell; 72 int len; 73 74 debug("get_addr: %s\n", prop_name); 75 cell = fdt_getprop(blob, node, prop_name, &len); 76 if (cell && (len == sizeof(fdt_addr_t) || 77 len == sizeof(fdt_addr_t) * 2)) 78 return fdt_addr_to_cpu(*cell); 79 return FDT_ADDR_T_NONE; 80 } 81 82 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name, 83 s32 default_val) 84 { 85 const s32 *cell; 86 int len; 87 88 debug("get_size: %s\n", prop_name); 89 cell = fdt_getprop(blob, node, prop_name, &len); 90 if (cell && len >= sizeof(s32)) 91 return fdt32_to_cpu(cell[0]); 92 return default_val; 93 } 94 95 int fdtdec_get_is_enabled(const void *blob, int node) 96 { 97 const char *cell; 98 99 /* 100 * It should say "okay", so only allow that. Some fdts use "ok" but 101 * this is a bug. Please fix your device tree source file. See here 102 * for discussion: 103 * 104 * http://www.mail-archive.com/u-boot@lists.denx.de/msg71598.html 105 */ 106 cell = fdt_getprop(blob, node, "status", NULL); 107 if (cell) 108 return 0 == strcmp(cell, "okay"); 109 return 1; 110 } 111 112 enum fdt_compat_id fd_dec_lookup(const void *blob, int node) 113 { 114 enum fdt_compat_id id; 115 116 /* Search our drivers */ 117 for (id = COMPAT_UNKNOWN; id < COMPAT_COUNT; id++) 118 if (0 == fdt_node_check_compatible(blob, node, 119 compat_names[id])) 120 return id; 121 return COMPAT_UNKNOWN; 122 } 123 124 int fdtdec_next_compatible(const void *blob, int node, 125 enum fdt_compat_id id) 126 { 127 return fdt_node_offset_by_compatible(blob, node, compat_names[id]); 128 } 129 130 int fdtdec_next_alias(const void *blob, const char *name, 131 enum fdt_compat_id id, int *upto) 132 { 133 #define MAX_STR_LEN 20 134 char str[MAX_STR_LEN + 20]; 135 int node, err; 136 137 /* snprintf() is not available */ 138 assert(strlen(name) < MAX_STR_LEN); 139 sprintf(str, "%.*s%d", MAX_STR_LEN, name, *upto); 140 node = find_alias_node(blob, str); 141 if (node < 0) 142 return node; 143 err = fdt_node_check_compatible(blob, node, compat_names[id]); 144 if (err < 0) 145 return err; 146 if (err) 147 return -FDT_ERR_NOTFOUND; 148 (*upto)++; 149 return node; 150 } 151 152 /* TODO: Can we tighten this code up a little? */ 153 int fdtdec_find_aliases_for_id(const void *blob, const char *name, 154 enum fdt_compat_id id, int *node_list, int maxcount) 155 { 156 int name_len = strlen(name); 157 int nodes[maxcount]; 158 int num_found = 0; 159 int offset, node; 160 int alias_node; 161 int count; 162 int i, j; 163 164 /* find the alias node if present */ 165 alias_node = fdt_path_offset(blob, "/aliases"); 166 167 /* 168 * start with nothing, and we can assume that the root node can't 169 * match 170 */ 171 memset(nodes, '\0', sizeof(nodes)); 172 173 /* First find all the compatible nodes */ 174 for (node = count = 0; node >= 0 && count < maxcount;) { 175 node = fdtdec_next_compatible(blob, node, id); 176 if (node >= 0) 177 nodes[count++] = node; 178 } 179 if (node >= 0) 180 debug("%s: warning: maxcount exceeded with alias '%s'\n", 181 __func__, name); 182 183 /* Now find all the aliases */ 184 memset(node_list, '\0', sizeof(*node_list) * maxcount); 185 186 for (offset = fdt_first_property_offset(blob, alias_node); 187 offset > 0; 188 offset = fdt_next_property_offset(blob, offset)) { 189 const struct fdt_property *prop; 190 const char *path; 191 int number; 192 int found; 193 194 node = 0; 195 prop = fdt_get_property_by_offset(blob, offset, NULL); 196 path = fdt_string(blob, fdt32_to_cpu(prop->nameoff)); 197 if (prop->len && 0 == strncmp(path, name, name_len)) 198 node = fdt_path_offset(blob, prop->data); 199 if (node <= 0) 200 continue; 201 202 /* Get the alias number */ 203 number = simple_strtoul(path + name_len, NULL, 10); 204 if (number < 0 || number >= maxcount) { 205 debug("%s: warning: alias '%s' is out of range\n", 206 __func__, path); 207 continue; 208 } 209 210 /* Make sure the node we found is actually in our list! */ 211 found = -1; 212 for (j = 0; j < count; j++) 213 if (nodes[j] == node) { 214 found = j; 215 break; 216 } 217 218 if (found == -1) { 219 debug("%s: warning: alias '%s' points to a node " 220 "'%s' that is missing or is not compatible " 221 " with '%s'\n", __func__, path, 222 fdt_get_name(blob, node, NULL), 223 compat_names[id]); 224 continue; 225 } 226 227 /* 228 * Add this node to our list in the right place, and mark 229 * it as done. 230 */ 231 if (fdtdec_get_is_enabled(blob, node)) { 232 node_list[number] = node; 233 if (number >= num_found) 234 num_found = number + 1; 235 } 236 nodes[j] = 0; 237 } 238 239 /* Add any nodes not mentioned by an alias */ 240 for (i = j = 0; i < maxcount; i++) { 241 if (!node_list[i]) { 242 for (; j < maxcount; j++) 243 if (nodes[j] && 244 fdtdec_get_is_enabled(blob, nodes[j])) 245 break; 246 247 /* Have we run out of nodes to add? */ 248 if (j == maxcount) 249 break; 250 251 assert(!node_list[i]); 252 node_list[i] = nodes[j++]; 253 if (i >= num_found) 254 num_found = i + 1; 255 } 256 } 257 258 return num_found; 259 } 260 261 /* 262 * This function is a little odd in that it accesses global data. At some 263 * point if the architecture board.c files merge this will make more sense. 264 * Even now, it is common code. 265 */ 266 int fdtdec_check_fdt(void) 267 { 268 /* We must have an fdt */ 269 if (((uintptr_t)gd->fdt_blob & 3) || fdt_check_header(gd->fdt_blob)) 270 panic("No valid fdt found - please append one to U-Boot\n" 271 "binary or define CONFIG_OF_EMBED\n"); 272 return 0; 273 } 274 275 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name) 276 { 277 const u32 *phandle; 278 int lookup; 279 280 phandle = fdt_getprop(blob, node, prop_name, NULL); 281 if (!phandle) 282 return -FDT_ERR_NOTFOUND; 283 284 lookup = fdt_node_offset_by_phandle(blob, fdt32_to_cpu(*phandle)); 285 return lookup; 286 } 287 288 /** 289 * Look up a property in a node and check that it has a minimum length. 290 * 291 * @param blob FDT blob 292 * @param node node to examine 293 * @param prop_name name of property to find 294 * @param min_len minimum property length in bytes 295 * @param err 0 if ok, or -FDT_ERR_NOTFOUND if the property is not 296 found, or -FDT_ERR_BADLAYOUT if not enough data 297 * @return pointer to cell, which is only valid if err == 0 298 */ 299 static const void *get_prop_check_min_len(const void *blob, int node, 300 const char *prop_name, int min_len, int *err) 301 { 302 const void *cell; 303 int len; 304 305 debug("%s: %s\n", __func__, prop_name); 306 cell = fdt_getprop(blob, node, prop_name, &len); 307 if (!cell) 308 *err = -FDT_ERR_NOTFOUND; 309 else if (len < min_len) 310 *err = -FDT_ERR_BADLAYOUT; 311 else 312 *err = 0; 313 return cell; 314 } 315 316 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name, 317 u32 *array, int count) 318 { 319 const u32 *cell; 320 int i, err = 0; 321 322 debug("%s: %s\n", __func__, prop_name); 323 cell = get_prop_check_min_len(blob, node, prop_name, 324 sizeof(u32) * count, &err); 325 if (!err) { 326 for (i = 0; i < count; i++) 327 array[i] = fdt32_to_cpu(cell[i]); 328 } 329 return err; 330 } 331 332 int fdtdec_get_bool(const void *blob, int node, const char *prop_name) 333 { 334 const s32 *cell; 335 int len; 336 337 debug("%s: %s\n", __func__, prop_name); 338 cell = fdt_getprop(blob, node, prop_name, &len); 339 return cell != NULL; 340 } 341