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 #include <asm/gpio.h> 28 29 DECLARE_GLOBAL_DATA_PTR; 30 31 /* 32 * Here are the type we know about. One day we might allow drivers to 33 * register. For now we just put them here. The COMPAT macro allows us to 34 * turn this into a sparse list later, and keeps the ID with the name. 35 */ 36 #define COMPAT(id, name) name 37 static const char * const compat_names[COMPAT_COUNT] = { 38 COMPAT(UNKNOWN, "<none>"), 39 COMPAT(NVIDIA_TEGRA20_USB, "nvidia,tegra20-ehci"), 40 COMPAT(NVIDIA_TEGRA20_I2C, "nvidia,tegra20-i2c"), 41 COMPAT(NVIDIA_TEGRA20_DVC, "nvidia,tegra20-i2c-dvc"), 42 COMPAT(NVIDIA_TEGRA20_EMC, "nvidia,tegra20-emc"), 43 COMPAT(NVIDIA_TEGRA20_EMC_TABLE, "nvidia,tegra20-emc-table"), 44 COMPAT(NVIDIA_TEGRA20_KBC, "nvidia,tegra20-kbc"), 45 COMPAT(NVIDIA_TEGRA20_NAND, "nvidia,tegra20-nand"), 46 }; 47 48 const char *fdtdec_get_compatible(enum fdt_compat_id id) 49 { 50 /* We allow reading of the 'unknown' ID for testing purposes */ 51 assert(id >= 0 && id < COMPAT_COUNT); 52 return compat_names[id]; 53 } 54 55 /** 56 * Look in the FDT for an alias with the given name and return its node. 57 * 58 * @param blob FDT blob 59 * @param name alias name to look up 60 * @return node offset if found, or an error code < 0 otherwise 61 */ 62 static int find_alias_node(const void *blob, const char *name) 63 { 64 const char *path; 65 int alias_node; 66 67 debug("find_alias_node: %s\n", name); 68 alias_node = fdt_path_offset(blob, "/aliases"); 69 if (alias_node < 0) 70 return alias_node; 71 path = fdt_getprop(blob, alias_node, name, NULL); 72 if (!path) 73 return -FDT_ERR_NOTFOUND; 74 return fdt_path_offset(blob, path); 75 } 76 77 fdt_addr_t fdtdec_get_addr(const void *blob, int node, 78 const char *prop_name) 79 { 80 const fdt_addr_t *cell; 81 int len; 82 83 debug("%s: %s: ", __func__, prop_name); 84 cell = fdt_getprop(blob, node, prop_name, &len); 85 if (cell && (len == sizeof(fdt_addr_t) || 86 len == sizeof(fdt_addr_t) * 2)) { 87 fdt_addr_t addr = fdt_addr_to_cpu(*cell); 88 89 debug("%p\n", (void *)addr); 90 return addr; 91 } 92 debug("(not found)\n"); 93 return FDT_ADDR_T_NONE; 94 } 95 96 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name, 97 s32 default_val) 98 { 99 const s32 *cell; 100 int len; 101 102 debug("%s: %s: ", __func__, prop_name); 103 cell = fdt_getprop(blob, node, prop_name, &len); 104 if (cell && len >= sizeof(s32)) { 105 s32 val = fdt32_to_cpu(cell[0]); 106 107 debug("%#x (%d)\n", val, val); 108 return val; 109 } 110 debug("(not found)\n"); 111 return default_val; 112 } 113 114 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name, 115 uint64_t default_val) 116 { 117 const uint64_t *cell64; 118 int length; 119 120 cell64 = fdt_getprop(blob, node, prop_name, &length); 121 if (!cell64 || length < sizeof(*cell64)) 122 return default_val; 123 124 return fdt64_to_cpu(*cell64); 125 } 126 127 int fdtdec_get_is_enabled(const void *blob, int node) 128 { 129 const char *cell; 130 131 /* 132 * It should say "okay", so only allow that. Some fdts use "ok" but 133 * this is a bug. Please fix your device tree source file. See here 134 * for discussion: 135 * 136 * http://www.mail-archive.com/u-boot@lists.denx.de/msg71598.html 137 */ 138 cell = fdt_getprop(blob, node, "status", NULL); 139 if (cell) 140 return 0 == strcmp(cell, "okay"); 141 return 1; 142 } 143 144 enum fdt_compat_id fdtdec_lookup(const void *blob, int node) 145 { 146 enum fdt_compat_id id; 147 148 /* Search our drivers */ 149 for (id = COMPAT_UNKNOWN; id < COMPAT_COUNT; id++) 150 if (0 == fdt_node_check_compatible(blob, node, 151 compat_names[id])) 152 return id; 153 return COMPAT_UNKNOWN; 154 } 155 156 int fdtdec_next_compatible(const void *blob, int node, 157 enum fdt_compat_id id) 158 { 159 return fdt_node_offset_by_compatible(blob, node, compat_names[id]); 160 } 161 162 int fdtdec_next_compatible_subnode(const void *blob, int node, 163 enum fdt_compat_id id, int *depthp) 164 { 165 do { 166 node = fdt_next_node(blob, node, depthp); 167 } while (*depthp > 1); 168 169 /* If this is a direct subnode, and compatible, return it */ 170 if (*depthp == 1 && 0 == fdt_node_check_compatible( 171 blob, node, compat_names[id])) 172 return node; 173 174 return -FDT_ERR_NOTFOUND; 175 } 176 177 int fdtdec_next_alias(const void *blob, const char *name, 178 enum fdt_compat_id id, int *upto) 179 { 180 #define MAX_STR_LEN 20 181 char str[MAX_STR_LEN + 20]; 182 int node, err; 183 184 /* snprintf() is not available */ 185 assert(strlen(name) < MAX_STR_LEN); 186 sprintf(str, "%.*s%d", MAX_STR_LEN, name, *upto); 187 node = find_alias_node(blob, str); 188 if (node < 0) 189 return node; 190 err = fdt_node_check_compatible(blob, node, compat_names[id]); 191 if (err < 0) 192 return err; 193 if (err) 194 return -FDT_ERR_NOTFOUND; 195 (*upto)++; 196 return node; 197 } 198 199 int fdtdec_find_aliases_for_id(const void *blob, const char *name, 200 enum fdt_compat_id id, int *node_list, int maxcount) 201 { 202 memset(node_list, '\0', sizeof(*node_list) * maxcount); 203 204 return fdtdec_add_aliases_for_id(blob, name, id, node_list, maxcount); 205 } 206 207 /* TODO: Can we tighten this code up a little? */ 208 int fdtdec_add_aliases_for_id(const void *blob, const char *name, 209 enum fdt_compat_id id, int *node_list, int maxcount) 210 { 211 int name_len = strlen(name); 212 int nodes[maxcount]; 213 int num_found = 0; 214 int offset, node; 215 int alias_node; 216 int count; 217 int i, j; 218 219 /* find the alias node if present */ 220 alias_node = fdt_path_offset(blob, "/aliases"); 221 222 /* 223 * start with nothing, and we can assume that the root node can't 224 * match 225 */ 226 memset(nodes, '\0', sizeof(nodes)); 227 228 /* First find all the compatible nodes */ 229 for (node = count = 0; node >= 0 && count < maxcount;) { 230 node = fdtdec_next_compatible(blob, node, id); 231 if (node >= 0) 232 nodes[count++] = node; 233 } 234 if (node >= 0) 235 debug("%s: warning: maxcount exceeded with alias '%s'\n", 236 __func__, name); 237 238 /* Now find all the aliases */ 239 for (offset = fdt_first_property_offset(blob, alias_node); 240 offset > 0; 241 offset = fdt_next_property_offset(blob, offset)) { 242 const struct fdt_property *prop; 243 const char *path; 244 int number; 245 int found; 246 247 node = 0; 248 prop = fdt_get_property_by_offset(blob, offset, NULL); 249 path = fdt_string(blob, fdt32_to_cpu(prop->nameoff)); 250 if (prop->len && 0 == strncmp(path, name, name_len)) 251 node = fdt_path_offset(blob, prop->data); 252 if (node <= 0) 253 continue; 254 255 /* Get the alias number */ 256 number = simple_strtoul(path + name_len, NULL, 10); 257 if (number < 0 || number >= maxcount) { 258 debug("%s: warning: alias '%s' is out of range\n", 259 __func__, path); 260 continue; 261 } 262 263 /* Make sure the node we found is actually in our list! */ 264 found = -1; 265 for (j = 0; j < count; j++) 266 if (nodes[j] == node) { 267 found = j; 268 break; 269 } 270 271 if (found == -1) { 272 debug("%s: warning: alias '%s' points to a node " 273 "'%s' that is missing or is not compatible " 274 " with '%s'\n", __func__, path, 275 fdt_get_name(blob, node, NULL), 276 compat_names[id]); 277 continue; 278 } 279 280 /* 281 * Add this node to our list in the right place, and mark 282 * it as done. 283 */ 284 if (fdtdec_get_is_enabled(blob, node)) { 285 if (node_list[number]) { 286 debug("%s: warning: alias '%s' requires that " 287 "a node be placed in the list in a " 288 "position which is already filled by " 289 "node '%s'\n", __func__, path, 290 fdt_get_name(blob, node, NULL)); 291 continue; 292 } 293 node_list[number] = node; 294 if (number >= num_found) 295 num_found = number + 1; 296 } 297 nodes[found] = 0; 298 } 299 300 /* Add any nodes not mentioned by an alias */ 301 for (i = j = 0; i < maxcount; i++) { 302 if (!node_list[i]) { 303 for (; j < maxcount; j++) 304 if (nodes[j] && 305 fdtdec_get_is_enabled(blob, nodes[j])) 306 break; 307 308 /* Have we run out of nodes to add? */ 309 if (j == maxcount) 310 break; 311 312 assert(!node_list[i]); 313 node_list[i] = nodes[j++]; 314 if (i >= num_found) 315 num_found = i + 1; 316 } 317 } 318 319 return num_found; 320 } 321 322 int fdtdec_check_fdt(void) 323 { 324 /* 325 * We must have an FDT, but we cannot panic() yet since the console 326 * is not ready. So for now, just assert(). Boards which need an early 327 * FDT (prior to console ready) will need to make their own 328 * arrangements and do their own checks. 329 */ 330 assert(!fdtdec_prepare_fdt()); 331 return 0; 332 } 333 334 /* 335 * This function is a little odd in that it accesses global data. At some 336 * point if the architecture board.c files merge this will make more sense. 337 * Even now, it is common code. 338 */ 339 int fdtdec_prepare_fdt(void) 340 { 341 if (((uintptr_t)gd->fdt_blob & 3) || fdt_check_header(gd->fdt_blob)) { 342 printf("No valid FDT found - please append one to U-Boot " 343 "binary, use u-boot-dtb.bin or define " 344 "CONFIG_OF_EMBED\n"); 345 return -1; 346 } 347 return 0; 348 } 349 350 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name) 351 { 352 const u32 *phandle; 353 int lookup; 354 355 debug("%s: %s\n", __func__, prop_name); 356 phandle = fdt_getprop(blob, node, prop_name, NULL); 357 if (!phandle) 358 return -FDT_ERR_NOTFOUND; 359 360 lookup = fdt_node_offset_by_phandle(blob, fdt32_to_cpu(*phandle)); 361 return lookup; 362 } 363 364 /** 365 * Look up a property in a node and check that it has a minimum length. 366 * 367 * @param blob FDT blob 368 * @param node node to examine 369 * @param prop_name name of property to find 370 * @param min_len minimum property length in bytes 371 * @param err 0 if ok, or -FDT_ERR_NOTFOUND if the property is not 372 found, or -FDT_ERR_BADLAYOUT if not enough data 373 * @return pointer to cell, which is only valid if err == 0 374 */ 375 static const void *get_prop_check_min_len(const void *blob, int node, 376 const char *prop_name, int min_len, int *err) 377 { 378 const void *cell; 379 int len; 380 381 debug("%s: %s\n", __func__, prop_name); 382 cell = fdt_getprop(blob, node, prop_name, &len); 383 if (!cell) 384 *err = -FDT_ERR_NOTFOUND; 385 else if (len < min_len) 386 *err = -FDT_ERR_BADLAYOUT; 387 else 388 *err = 0; 389 return cell; 390 } 391 392 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name, 393 u32 *array, int count) 394 { 395 const u32 *cell; 396 int i, err = 0; 397 398 debug("%s: %s\n", __func__, prop_name); 399 cell = get_prop_check_min_len(blob, node, prop_name, 400 sizeof(u32) * count, &err); 401 if (!err) { 402 for (i = 0; i < count; i++) 403 array[i] = fdt32_to_cpu(cell[i]); 404 } 405 return err; 406 } 407 408 const u32 *fdtdec_locate_array(const void *blob, int node, 409 const char *prop_name, int count) 410 { 411 const u32 *cell; 412 int err; 413 414 cell = get_prop_check_min_len(blob, node, prop_name, 415 sizeof(u32) * count, &err); 416 return err ? NULL : cell; 417 } 418 419 int fdtdec_get_bool(const void *blob, int node, const char *prop_name) 420 { 421 const s32 *cell; 422 int len; 423 424 debug("%s: %s\n", __func__, prop_name); 425 cell = fdt_getprop(blob, node, prop_name, &len); 426 return cell != NULL; 427 } 428 429 /** 430 * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no 431 * terminating item. 432 * 433 * @param blob FDT blob to use 434 * @param node Node to look at 435 * @param prop_name Node property name 436 * @param gpio Array of gpio elements to fill from FDT. This will be 437 * untouched if either 0 or an error is returned 438 * @param max_count Maximum number of elements allowed 439 * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would 440 * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing. 441 */ 442 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name, 443 struct fdt_gpio_state *gpio, int max_count) 444 { 445 const struct fdt_property *prop; 446 const u32 *cell; 447 const char *name; 448 int len, i; 449 450 debug("%s: %s\n", __func__, prop_name); 451 assert(max_count > 0); 452 prop = fdt_get_property(blob, node, prop_name, &len); 453 if (!prop) { 454 debug("%s: property '%s' missing\n", __func__, prop_name); 455 return -FDT_ERR_NOTFOUND; 456 } 457 458 /* We will use the name to tag the GPIO */ 459 name = fdt_string(blob, fdt32_to_cpu(prop->nameoff)); 460 cell = (u32 *)prop->data; 461 len /= sizeof(u32) * 3; /* 3 cells per GPIO record */ 462 if (len > max_count) { 463 debug(" %s: too many GPIOs / cells for " 464 "property '%s'\n", __func__, prop_name); 465 return -FDT_ERR_BADLAYOUT; 466 } 467 468 /* Read out the GPIO data from the cells */ 469 for (i = 0; i < len; i++, cell += 3) { 470 gpio[i].gpio = fdt32_to_cpu(cell[1]); 471 gpio[i].flags = fdt32_to_cpu(cell[2]); 472 gpio[i].name = name; 473 } 474 475 return len; 476 } 477 478 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name, 479 struct fdt_gpio_state *gpio) 480 { 481 int err; 482 483 debug("%s: %s\n", __func__, prop_name); 484 gpio->gpio = FDT_GPIO_NONE; 485 gpio->name = NULL; 486 err = fdtdec_decode_gpios(blob, node, prop_name, gpio, 1); 487 return err == 1 ? 0 : err; 488 } 489 490 int fdtdec_get_gpio(struct fdt_gpio_state *gpio) 491 { 492 int val; 493 494 if (!fdt_gpio_isvalid(gpio)) 495 return -1; 496 497 val = gpio_get_value(gpio->gpio); 498 return gpio->flags & FDT_GPIO_ACTIVE_LOW ? val ^ 1 : val; 499 } 500 501 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val) 502 { 503 if (!fdt_gpio_isvalid(gpio)) 504 return -1; 505 506 val = gpio->flags & FDT_GPIO_ACTIVE_LOW ? val ^ 1 : val; 507 return gpio_set_value(gpio->gpio, val); 508 } 509 510 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio) 511 { 512 /* 513 * Return success if there is no GPIO defined. This is used for 514 * optional GPIOs) 515 */ 516 if (!fdt_gpio_isvalid(gpio)) 517 return 0; 518 519 if (gpio_request(gpio->gpio, gpio->name)) 520 return -1; 521 return 0; 522 } 523 524 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name, 525 u8 *array, int count) 526 { 527 const u8 *cell; 528 int err; 529 530 cell = get_prop_check_min_len(blob, node, prop_name, count, &err); 531 if (!err) 532 memcpy(array, cell, count); 533 return err; 534 } 535 536 const u8 *fdtdec_locate_byte_array(const void *blob, int node, 537 const char *prop_name, int count) 538 { 539 const u8 *cell; 540 int err; 541 542 cell = get_prop_check_min_len(blob, node, prop_name, count, &err); 543 if (err) 544 return NULL; 545 return cell; 546 } 547 548 int fdtdec_get_config_int(const void *blob, const char *prop_name, 549 int default_val) 550 { 551 int config_node; 552 553 debug("%s: %s\n", __func__, prop_name); 554 config_node = fdt_path_offset(blob, "/config"); 555 if (config_node < 0) 556 return default_val; 557 return fdtdec_get_int(blob, config_node, prop_name, default_val); 558 } 559 560 int fdtdec_get_config_bool(const void *blob, const char *prop_name) 561 { 562 int config_node; 563 const void *prop; 564 565 debug("%s: %s\n", __func__, prop_name); 566 config_node = fdt_path_offset(blob, "/config"); 567 if (config_node < 0) 568 return 0; 569 prop = fdt_get_property(blob, config_node, prop_name, NULL); 570 571 return prop != NULL; 572 } 573 574 char *fdtdec_get_config_string(const void *blob, const char *prop_name) 575 { 576 const char *nodep; 577 int nodeoffset; 578 int len; 579 580 debug("%s: %s\n", __func__, prop_name); 581 nodeoffset = fdt_path_offset(blob, "/config"); 582 if (nodeoffset < 0) 583 return NULL; 584 585 nodep = fdt_getprop(blob, nodeoffset, prop_name, &len); 586 if (!nodep) 587 return NULL; 588 589 return (char *)nodep; 590 } 591 592 int fdtdec_decode_region(const void *blob, int node, 593 const char *prop_name, void **ptrp, size_t *size) 594 { 595 const fdt_addr_t *cell; 596 int len; 597 598 debug("%s: %s\n", __func__, prop_name); 599 cell = fdt_getprop(blob, node, prop_name, &len); 600 if (!cell || (len != sizeof(fdt_addr_t) * 2)) 601 return -1; 602 603 *ptrp = (void *)fdt_addr_to_cpu(*cell); 604 *size = fdt_size_to_cpu(cell[1]); 605 debug("%s: size=%zx\n", __func__, *size); 606 return 0; 607 } 608