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 /* we need the generic GPIO interface here */ 28 #include <asm-generic/gpio.h> 29 30 DECLARE_GLOBAL_DATA_PTR; 31 32 /* 33 * Here are the type we know about. One day we might allow drivers to 34 * register. For now we just put them here. The COMPAT macro allows us to 35 * turn this into a sparse list later, and keeps the ID with the name. 36 */ 37 #define COMPAT(id, name) name 38 static const char * const compat_names[COMPAT_COUNT] = { 39 COMPAT(UNKNOWN, "<none>"), 40 }; 41 42 const char *fdtdec_get_compatible(enum fdt_compat_id id) 43 { 44 /* We allow reading of the 'unknown' ID for testing purposes */ 45 assert(id >= 0 && id < COMPAT_COUNT); 46 return compat_names[id]; 47 } 48 49 /** 50 * Look in the FDT for an alias with the given name and return its node. 51 * 52 * @param blob FDT blob 53 * @param name alias name to look up 54 * @return node offset if found, or an error code < 0 otherwise 55 */ 56 static int find_alias_node(const void *blob, const char *name) 57 { 58 const char *path; 59 int alias_node; 60 61 debug("find_alias_node: %s\n", name); 62 alias_node = fdt_path_offset(blob, "/aliases"); 63 if (alias_node < 0) 64 return alias_node; 65 path = fdt_getprop(blob, alias_node, name, NULL); 66 if (!path) 67 return -FDT_ERR_NOTFOUND; 68 return fdt_path_offset(blob, path); 69 } 70 71 fdt_addr_t fdtdec_get_addr(const void *blob, int node, 72 const char *prop_name) 73 { 74 const fdt_addr_t *cell; 75 int len; 76 77 debug("get_addr: %s\n", prop_name); 78 cell = fdt_getprop(blob, node, prop_name, &len); 79 if (cell && (len == sizeof(fdt_addr_t) || 80 len == sizeof(fdt_addr_t) * 2)) 81 return fdt_addr_to_cpu(*cell); 82 return FDT_ADDR_T_NONE; 83 } 84 85 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name, 86 s32 default_val) 87 { 88 const s32 *cell; 89 int len; 90 91 debug("get_size: %s\n", prop_name); 92 cell = fdt_getprop(blob, node, prop_name, &len); 93 if (cell && len >= sizeof(s32)) 94 return fdt32_to_cpu(cell[0]); 95 return default_val; 96 } 97 98 int fdtdec_get_is_enabled(const void *blob, int node) 99 { 100 const char *cell; 101 102 /* 103 * It should say "okay", so only allow that. Some fdts use "ok" but 104 * this is a bug. Please fix your device tree source file. See here 105 * for discussion: 106 * 107 * http://www.mail-archive.com/u-boot@lists.denx.de/msg71598.html 108 */ 109 cell = fdt_getprop(blob, node, "status", NULL); 110 if (cell) 111 return 0 == strcmp(cell, "okay"); 112 return 1; 113 } 114 115 enum fdt_compat_id fd_dec_lookup(const void *blob, int node) 116 { 117 enum fdt_compat_id id; 118 119 /* Search our drivers */ 120 for (id = COMPAT_UNKNOWN; id < COMPAT_COUNT; id++) 121 if (0 == fdt_node_check_compatible(blob, node, 122 compat_names[id])) 123 return id; 124 return COMPAT_UNKNOWN; 125 } 126 127 int fdtdec_next_compatible(const void *blob, int node, 128 enum fdt_compat_id id) 129 { 130 return fdt_node_offset_by_compatible(blob, node, compat_names[id]); 131 } 132 133 int fdtdec_next_alias(const void *blob, const char *name, 134 enum fdt_compat_id id, int *upto) 135 { 136 #define MAX_STR_LEN 20 137 char str[MAX_STR_LEN + 20]; 138 int node, err; 139 140 /* snprintf() is not available */ 141 assert(strlen(name) < MAX_STR_LEN); 142 sprintf(str, "%.*s%d", MAX_STR_LEN, name, *upto); 143 node = find_alias_node(blob, str); 144 if (node < 0) 145 return node; 146 err = fdt_node_check_compatible(blob, node, compat_names[id]); 147 if (err < 0) 148 return err; 149 if (err) 150 return -FDT_ERR_NOTFOUND; 151 (*upto)++; 152 return node; 153 } 154 155 /* TODO: Can we tighten this code up a little? */ 156 int fdtdec_find_aliases_for_id(const void *blob, const char *name, 157 enum fdt_compat_id id, int *node_list, int maxcount) 158 { 159 int name_len = strlen(name); 160 int nodes[maxcount]; 161 int num_found = 0; 162 int offset, node; 163 int alias_node; 164 int count; 165 int i, j; 166 167 /* find the alias node if present */ 168 alias_node = fdt_path_offset(blob, "/aliases"); 169 170 /* 171 * start with nothing, and we can assume that the root node can't 172 * match 173 */ 174 memset(nodes, '\0', sizeof(nodes)); 175 176 /* First find all the compatible nodes */ 177 for (node = count = 0; node >= 0 && count < maxcount;) { 178 node = fdtdec_next_compatible(blob, node, id); 179 if (node >= 0) 180 nodes[count++] = node; 181 } 182 if (node >= 0) 183 debug("%s: warning: maxcount exceeded with alias '%s'\n", 184 __func__, name); 185 186 /* Now find all the aliases */ 187 memset(node_list, '\0', sizeof(*node_list) * maxcount); 188 189 for (offset = fdt_first_property_offset(blob, alias_node); 190 offset > 0; 191 offset = fdt_next_property_offset(blob, offset)) { 192 const struct fdt_property *prop; 193 const char *path; 194 int number; 195 int found; 196 197 node = 0; 198 prop = fdt_get_property_by_offset(blob, offset, NULL); 199 path = fdt_string(blob, fdt32_to_cpu(prop->nameoff)); 200 if (prop->len && 0 == strncmp(path, name, name_len)) 201 node = fdt_path_offset(blob, prop->data); 202 if (node <= 0) 203 continue; 204 205 /* Get the alias number */ 206 number = simple_strtoul(path + name_len, NULL, 10); 207 if (number < 0 || number >= maxcount) { 208 debug("%s: warning: alias '%s' is out of range\n", 209 __func__, path); 210 continue; 211 } 212 213 /* Make sure the node we found is actually in our list! */ 214 found = -1; 215 for (j = 0; j < count; j++) 216 if (nodes[j] == node) { 217 found = j; 218 break; 219 } 220 221 if (found == -1) { 222 debug("%s: warning: alias '%s' points to a node " 223 "'%s' that is missing or is not compatible " 224 " with '%s'\n", __func__, path, 225 fdt_get_name(blob, node, NULL), 226 compat_names[id]); 227 continue; 228 } 229 230 /* 231 * Add this node to our list in the right place, and mark 232 * it as done. 233 */ 234 if (fdtdec_get_is_enabled(blob, node)) { 235 node_list[number] = node; 236 if (number >= num_found) 237 num_found = number + 1; 238 } 239 nodes[j] = 0; 240 } 241 242 /* Add any nodes not mentioned by an alias */ 243 for (i = j = 0; i < maxcount; i++) { 244 if (!node_list[i]) { 245 for (; j < maxcount; j++) 246 if (nodes[j] && 247 fdtdec_get_is_enabled(blob, nodes[j])) 248 break; 249 250 /* Have we run out of nodes to add? */ 251 if (j == maxcount) 252 break; 253 254 assert(!node_list[i]); 255 node_list[i] = nodes[j++]; 256 if (i >= num_found) 257 num_found = i + 1; 258 } 259 } 260 261 return num_found; 262 } 263 264 /* 265 * This function is a little odd in that it accesses global data. At some 266 * point if the architecture board.c files merge this will make more sense. 267 * Even now, it is common code. 268 */ 269 int fdtdec_check_fdt(void) 270 { 271 /* We must have an fdt */ 272 if (((uintptr_t)gd->fdt_blob & 3) || fdt_check_header(gd->fdt_blob)) 273 panic("No valid fdt found - please append one to U-Boot\n" 274 "binary or define CONFIG_OF_EMBED\n"); 275 return 0; 276 } 277 278 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name) 279 { 280 const u32 *phandle; 281 int lookup; 282 283 phandle = fdt_getprop(blob, node, prop_name, NULL); 284 if (!phandle) 285 return -FDT_ERR_NOTFOUND; 286 287 lookup = fdt_node_offset_by_phandle(blob, fdt32_to_cpu(*phandle)); 288 return lookup; 289 } 290 291 /** 292 * Look up a property in a node and check that it has a minimum length. 293 * 294 * @param blob FDT blob 295 * @param node node to examine 296 * @param prop_name name of property to find 297 * @param min_len minimum property length in bytes 298 * @param err 0 if ok, or -FDT_ERR_NOTFOUND if the property is not 299 found, or -FDT_ERR_BADLAYOUT if not enough data 300 * @return pointer to cell, which is only valid if err == 0 301 */ 302 static const void *get_prop_check_min_len(const void *blob, int node, 303 const char *prop_name, int min_len, int *err) 304 { 305 const void *cell; 306 int len; 307 308 debug("%s: %s\n", __func__, prop_name); 309 cell = fdt_getprop(blob, node, prop_name, &len); 310 if (!cell) 311 *err = -FDT_ERR_NOTFOUND; 312 else if (len < min_len) 313 *err = -FDT_ERR_BADLAYOUT; 314 else 315 *err = 0; 316 return cell; 317 } 318 319 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name, 320 u32 *array, int count) 321 { 322 const u32 *cell; 323 int i, err = 0; 324 325 debug("%s: %s\n", __func__, prop_name); 326 cell = get_prop_check_min_len(blob, node, prop_name, 327 sizeof(u32) * count, &err); 328 if (!err) { 329 for (i = 0; i < count; i++) 330 array[i] = fdt32_to_cpu(cell[i]); 331 } 332 return err; 333 } 334 335 int fdtdec_get_bool(const void *blob, int node, const char *prop_name) 336 { 337 const s32 *cell; 338 int len; 339 340 debug("%s: %s\n", __func__, prop_name); 341 cell = fdt_getprop(blob, node, prop_name, &len); 342 return cell != NULL; 343 } 344 345 /** 346 * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no 347 * terminating item. 348 * 349 * @param blob FDT blob to use 350 * @param node Node to look at 351 * @param prop_name Node property name 352 * @param gpio Array of gpio elements to fill from FDT. This will be 353 * untouched if either 0 or an error is returned 354 * @param max_count Maximum number of elements allowed 355 * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would 356 * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing. 357 */ 358 static int fdtdec_decode_gpios(const void *blob, int node, 359 const char *prop_name, struct fdt_gpio_state *gpio, 360 int max_count) 361 { 362 const struct fdt_property *prop; 363 const u32 *cell; 364 const char *name; 365 int len, i; 366 367 debug("%s: %s\n", __func__, prop_name); 368 assert(max_count > 0); 369 prop = fdt_get_property(blob, node, prop_name, &len); 370 if (!prop) { 371 debug("FDT: %s: property '%s' missing\n", __func__, prop_name); 372 return -FDT_ERR_NOTFOUND; 373 } 374 375 /* We will use the name to tag the GPIO */ 376 name = fdt_string(blob, fdt32_to_cpu(prop->nameoff)); 377 cell = (u32 *)prop->data; 378 len /= sizeof(u32) * 3; /* 3 cells per GPIO record */ 379 if (len > max_count) { 380 debug("FDT: %s: too many GPIOs / cells for " 381 "property '%s'\n", __func__, prop_name); 382 return -FDT_ERR_BADLAYOUT; 383 } 384 385 /* Read out the GPIO data from the cells */ 386 for (i = 0; i < len; i++, cell += 3) { 387 gpio[i].gpio = fdt32_to_cpu(cell[1]); 388 gpio[i].flags = fdt32_to_cpu(cell[2]); 389 gpio[i].name = name; 390 } 391 392 return len; 393 } 394 395 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name, 396 struct fdt_gpio_state *gpio) 397 { 398 int err; 399 400 debug("%s: %s\n", __func__, prop_name); 401 gpio->gpio = FDT_GPIO_NONE; 402 gpio->name = NULL; 403 err = fdtdec_decode_gpios(blob, node, prop_name, gpio, 1); 404 return err == 1 ? 0 : err; 405 } 406 407 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio) 408 { 409 /* 410 * Return success if there is no GPIO defined. This is used for 411 * optional GPIOs) 412 */ 413 if (!fdt_gpio_isvalid(gpio)) 414 return 0; 415 416 if (gpio_request(gpio->gpio, gpio->name)) 417 return -1; 418 return 0; 419 } 420