lib/fdtdec.c

   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         COMPAT(NVIDIA_TEGRA20_PWM, "nvidia,tegra20-pwm"),
  47         COMPAT(NVIDIA_TEGRA20_DC, "nvidia,tegra20-dc"),
  48 };
  49
  50 const char *fdtdec_get_compatible(enum fdt_compat_id id)
  51 {
  52         /* We allow reading of the 'unknown' ID for testing purposes */
  53         assert(id >= 0 && id < COMPAT_COUNT);
  54         return compat_names[id];
  55 }
  56
  57 fdt_addr_t fdtdec_get_addr(const void *blob, int node,
  58                 const char *prop_name)
  59 {
  60         const fdt_addr_t *cell;
  61         int len;
  62
  63         debug("%s: %s: ", __func__, prop_name);
  64         cell = fdt_getprop(blob, node, prop_name, &len);
  65         if (cell && (len == sizeof(fdt_addr_t) ||
  66                         len == sizeof(fdt_addr_t) * 2)) {
  67                 fdt_addr_t addr = fdt_addr_to_cpu(*cell);
  68
  69                 debug("%p\n", (void *)addr);
  70                 return addr;
  71         }
  72         debug("(not found)\n");
  73         return FDT_ADDR_T_NONE;
  74 }
  75
  76 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
  77                 s32 default_val)
  78 {
  79         const s32 *cell;
  80         int len;
  81
  82         debug("%s: %s: ", __func__, prop_name);
  83         cell = fdt_getprop(blob, node, prop_name, &len);
  84         if (cell && len >= sizeof(s32)) {
  85                 s32 val = fdt32_to_cpu(cell[0]);
  86
  87                 debug("%#x (%d)\n", val, val);
  88                 return val;
  89         }
  90         debug("(not found)\n");
  91         return default_val;
  92 }
  93
  94 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
  95                 uint64_t default_val)
  96 {
  97         const uint64_t *cell64;
  98         int length;
  99
 100         cell64 = fdt_getprop(blob, node, prop_name, &length);
 101         if (!cell64 || length < sizeof(*cell64))
 102                 return default_val;
 103
 104         return fdt64_to_cpu(*cell64);
 105 }
 106
 107 int fdtdec_get_is_enabled(const void *blob, int node)
 108 {
 109         const char *cell;
 110
 111         /*
 112          * It should say "okay", so only allow that. Some fdts use "ok" but
 113          * this is a bug. Please fix your device tree source file. See here
 114          * for discussion:
 115          *
 116          * http://www.mail-archive.com/u-boot@lists.denx.de/msg71598.html
 117          */
 118         cell = fdt_getprop(blob, node, "status", NULL);
 119         if (cell)
 120                 return 0 == strcmp(cell, "okay");
 121         return 1;
 122 }
 123
 124 enum fdt_compat_id fdtdec_lookup(const void *blob, int node)
 125 {
 126         enum fdt_compat_id id;
 127
 128         /* Search our drivers */
 129         for (id = COMPAT_UNKNOWN; id < COMPAT_COUNT; id++)
 130                 if (0 == fdt_node_check_compatible(blob, node,
 131                                 compat_names[id]))
 132                         return id;
 133         return COMPAT_UNKNOWN;
 134 }
 135
 136 int fdtdec_next_compatible(const void *blob, int node,
 137                 enum fdt_compat_id id)
 138 {
 139         return fdt_node_offset_by_compatible(blob, node, compat_names[id]);
 140 }
 141
 142 int fdtdec_next_compatible_subnode(const void *blob, int node,
 143                 enum fdt_compat_id id, int *depthp)
 144 {
 145         do {
 146                 node = fdt_next_node(blob, node, depthp);
 147         } while (*depthp > 1);
 148
 149         /* If this is a direct subnode, and compatible, return it */
 150         if (*depthp == 1 && 0 == fdt_node_check_compatible(
 151                                                 blob, node, compat_names[id]))
 152                 return node;
 153
 154         return -FDT_ERR_NOTFOUND;
 155 }
 156
 157 int fdtdec_next_alias(const void *blob, const char *name,
 158                 enum fdt_compat_id id, int *upto)
 159 {
 160 #define MAX_STR_LEN 20
 161         char str[MAX_STR_LEN + 20];
 162         int node, err;
 163
 164         /* snprintf() is not available */
 165         assert(strlen(name) < MAX_STR_LEN);
 166         sprintf(str, "%.*s%d", MAX_STR_LEN, name, *upto);
 167         node = fdt_path_offset(blob, str);
 168         if (node < 0)
 169                 return node;
 170         err = fdt_node_check_compatible(blob, node, compat_names[id]);
 171         if (err < 0)
 172                 return err;
 173         if (err)
 174                 return -FDT_ERR_NOTFOUND;
 175         (*upto)++;
 176         return node;
 177 }
 178
 179 int fdtdec_find_aliases_for_id(const void *blob, const char *name,
 180                         enum fdt_compat_id id, int *node_list, int maxcount)
 181 {
 182         memset(node_list, '\0', sizeof(*node_list) * maxcount);
 183
 184         return fdtdec_add_aliases_for_id(blob, name, id, node_list, maxcount);
 185 }
 186
 187 /* TODO: Can we tighten this code up a little? */
 188 int fdtdec_add_aliases_for_id(const void *blob, const char *name,
 189                         enum fdt_compat_id id, int *node_list, int maxcount)
 190 {
 191         int name_len = strlen(name);
 192         int nodes[maxcount];
 193         int num_found = 0;
 194         int offset, node;
 195         int alias_node;
 196         int count;
 197         int i, j;
 198
 199         /* find the alias node if present */
 200         alias_node = fdt_path_offset(blob, "/aliases");
 201
 202         /*
 203          * start with nothing, and we can assume that the root node can't
 204          * match
 205          */
 206         memset(nodes, '\0', sizeof(nodes));
 207
 208         /* First find all the compatible nodes */
 209         for (node = count = 0; node >= 0 && count < maxcount;) {
 210                 node = fdtdec_next_compatible(blob, node, id);
 211                 if (node >= 0)
 212                         nodes[count++] = node;
 213         }
 214         if (node >= 0)
 215                 debug("%s: warning: maxcount exceeded with alias '%s'\n",
 216                        __func__, name);
 217
 218         /* Now find all the aliases */
 219         for (offset = fdt_first_property_offset(blob, alias_node);
 220                         offset > 0;
 221                         offset = fdt_next_property_offset(blob, offset)) {
 222                 const struct fdt_property *prop;
 223                 const char *path;
 224                 int number;
 225                 int found;
 226
 227                 node = 0;
 228                 prop = fdt_get_property_by_offset(blob, offset, NULL);
 229                 path = fdt_string(blob, fdt32_to_cpu(prop->nameoff));
 230                 if (prop->len && 0 == strncmp(path, name, name_len))
 231                         node = fdt_path_offset(blob, prop->data);
 232                 if (node <= 0)
 233                         continue;
 234
 235                 /* Get the alias number */
 236                 number = simple_strtoul(path + name_len, NULL, 10);
 237                 if (number < 0 || number >= maxcount) {
 238                         debug("%s: warning: alias '%s' is out of range\n",
 239                                __func__, path);
 240                         continue;
 241                 }
 242
 243                 /* Make sure the node we found is actually in our list! */
 244                 found = -1;
 245                 for (j = 0; j < count; j++)
 246                         if (nodes[j] == node) {
 247                                 found = j;
 248                                 break;
 249                         }
 250
 251                 if (found == -1) {
 252                         debug("%s: warning: alias '%s' points to a node "
 253                                 "'%s' that is missing or is not compatible "
 254                                 " with '%s'\n", __func__, path,
 255                                 fdt_get_name(blob, node, NULL),
 256                                compat_names[id]);
 257                         continue;
 258                 }
 259
 260                 /*
 261                  * Add this node to our list in the right place, and mark
 262                  * it as done.
 263                  */
 264                 if (fdtdec_get_is_enabled(blob, node)) {
 265                         if (node_list[number]) {
 266                                 debug("%s: warning: alias '%s' requires that "
 267                                       "a node be placed in the list in a "
 268                                       "position which is already filled by "
 269                                       "node '%s'\n", __func__, path,
 270                                       fdt_get_name(blob, node, NULL));
 271                                 continue;
 272                         }
 273                         node_list[number] = node;
 274                         if (number >= num_found)
 275                                 num_found = number + 1;
 276                 }
 277                 nodes[found] = 0;
 278         }
 279
 280         /* Add any nodes not mentioned by an alias */
 281         for (i = j = 0; i < maxcount; i++) {
 282                 if (!node_list[i]) {
 283                         for (; j < maxcount; j++)
 284                                 if (nodes[j] &&
 285                                         fdtdec_get_is_enabled(blob, nodes[j]))
 286                                         break;
 287
 288                         /* Have we run out of nodes to add? */
 289                         if (j == maxcount)
 290                                 break;
 291
 292                         assert(!node_list[i]);
 293                         node_list[i] = nodes[j++];
 294                         if (i >= num_found)
 295                                 num_found = i + 1;
 296                 }
 297         }
 298
 299         return num_found;
 300 }
 301
 302 int fdtdec_check_fdt(void)
 303 {
 304         /*
 305          * We must have an FDT, but we cannot panic() yet since the console
 306          * is not ready. So for now, just assert(). Boards which need an early
 307          * FDT (prior to console ready) will need to make their own
 308          * arrangements and do their own checks.
 309          */
 310         assert(!fdtdec_prepare_fdt());
 311         return 0;
 312 }
 313
 314 /*
 315  * This function is a little odd in that it accesses global data. At some
 316  * point if the architecture board.c files merge this will make more sense.
 317  * Even now, it is common code.
 318  */
 319 int fdtdec_prepare_fdt(void)
 320 {
 321         if (((uintptr_t)gd->fdt_blob & 3) || fdt_check_header(gd->fdt_blob)) {
 322                 printf("No valid FDT found - please append one to U-Boot "
 323                         "binary, use u-boot-dtb.bin or define "
 324                         "CONFIG_OF_EMBED\n");
 325                 return -1;
 326         }
 327         return 0;
 328 }
 329
 330 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name)
 331 {
 332         const u32 *phandle;
 333         int lookup;
 334
 335         debug("%s: %s\n", __func__, prop_name);
 336         phandle = fdt_getprop(blob, node, prop_name, NULL);
 337         if (!phandle)
 338                 return -FDT_ERR_NOTFOUND;
 339
 340         lookup = fdt_node_offset_by_phandle(blob, fdt32_to_cpu(*phandle));
 341         return lookup;
 342 }
 343
 344 /**
 345  * Look up a property in a node and check that it has a minimum length.
 346  *
 347  * @param blob          FDT blob
 348  * @param node          node to examine
 349  * @param prop_name     name of property to find
 350  * @param min_len       minimum property length in bytes
 351  * @param err           0 if ok, or -FDT_ERR_NOTFOUND if the property is not
 352                         found, or -FDT_ERR_BADLAYOUT if not enough data
 353  * @return pointer to cell, which is only valid if err == 0
 354  */
 355 static const void *get_prop_check_min_len(const void *blob, int node,
 356                 const char *prop_name, int min_len, int *err)
 357 {
 358         const void *cell;
 359         int len;
 360
 361         debug("%s: %s\n", __func__, prop_name);
 362         cell = fdt_getprop(blob, node, prop_name, &len);
 363         if (!cell)
 364                 *err = -FDT_ERR_NOTFOUND;
 365         else if (len < min_len)
 366                 *err = -FDT_ERR_BADLAYOUT;
 367         else
 368                 *err = 0;
 369         return cell;
 370 }
 371
 372 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
 373                 u32 *array, int count)
 374 {
 375         const u32 *cell;
 376         int i, err = 0;
 377
 378         debug("%s: %s\n", __func__, prop_name);
 379         cell = get_prop_check_min_len(blob, node, prop_name,
 380                                       sizeof(u32) * count, &err);
 381         if (!err) {
 382                 for (i = 0; i < count; i++)
 383                         array[i] = fdt32_to_cpu(cell[i]);
 384         }
 385         return err;
 386 }
 387
 388 const u32 *fdtdec_locate_array(const void *blob, int node,
 389                                const char *prop_name, int count)
 390 {
 391         const u32 *cell;
 392         int err;
 393
 394         cell = get_prop_check_min_len(blob, node, prop_name,
 395                                       sizeof(u32) * count, &err);
 396         return err ? NULL : cell;
 397 }
 398
 399 int fdtdec_get_bool(const void *blob, int node, const char *prop_name)
 400 {
 401         const s32 *cell;
 402         int len;
 403
 404         debug("%s: %s\n", __func__, prop_name);
 405         cell = fdt_getprop(blob, node, prop_name, &len);
 406         return cell != NULL;
 407 }
 408
 409 /**
 410  * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no
 411  * terminating item.
 412  *
 413  * @param blob          FDT blob to use
 414  * @param node          Node to look at
 415  * @param prop_name     Node property name
 416  * @param gpio          Array of gpio elements to fill from FDT. This will be
 417  *                      untouched if either 0 or an error is returned
 418  * @param max_count     Maximum number of elements allowed
 419  * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would
 420  * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing.
 421  */
 422 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name,
 423                 struct fdt_gpio_state *gpio, int max_count)
 424 {
 425         const struct fdt_property *prop;
 426         const u32 *cell;
 427         const char *name;
 428         int len, i;
 429
 430         debug("%s: %s\n", __func__, prop_name);
 431         assert(max_count > 0);
 432         prop = fdt_get_property(blob, node, prop_name, &len);
 433         if (!prop) {
 434                 debug("%s: property '%s' missing\n", __func__, prop_name);
 435                 return -FDT_ERR_NOTFOUND;
 436         }
 437
 438         /* We will use the name to tag the GPIO */
 439         name = fdt_string(blob, fdt32_to_cpu(prop->nameoff));
 440         cell = (u32 *)prop->data;
 441         len /= sizeof(u32) * 3;         /* 3 cells per GPIO record */
 442         if (len > max_count) {
 443                 debug(" %s: too many GPIOs / cells for "
 444                         "property '%s'\n", __func__, prop_name);
 445                 return -FDT_ERR_BADLAYOUT;
 446         }
 447
 448         /* Read out the GPIO data from the cells */
 449         for (i = 0; i < len; i++, cell += 3) {
 450                 gpio[i].gpio = fdt32_to_cpu(cell[1]);
 451                 gpio[i].flags = fdt32_to_cpu(cell[2]);
 452                 gpio[i].name = name;
 453         }
 454
 455         return len;
 456 }
 457
 458 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name,
 459                 struct fdt_gpio_state *gpio)
 460 {
 461         int err;
 462
 463         debug("%s: %s\n", __func__, prop_name);
 464         gpio->gpio = FDT_GPIO_NONE;
 465         gpio->name = NULL;
 466         err = fdtdec_decode_gpios(blob, node, prop_name, gpio, 1);
 467         return err == 1 ? 0 : err;
 468 }
 469
 470 int fdtdec_get_gpio(struct fdt_gpio_state *gpio)
 471 {
 472         int val;
 473
 474         if (!fdt_gpio_isvalid(gpio))
 475                 return -1;
 476
 477         val = gpio_get_value(gpio->gpio);
 478         return gpio->flags & FDT_GPIO_ACTIVE_LOW ? val ^ 1 : val;
 479 }
 480
 481 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val)
 482 {
 483         if (!fdt_gpio_isvalid(gpio))
 484                 return -1;
 485
 486         val = gpio->flags & FDT_GPIO_ACTIVE_LOW ? val ^ 1 : val;
 487         return gpio_set_value(gpio->gpio, val);
 488 }
 489
 490 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio)
 491 {
 492         /*
 493          * Return success if there is no GPIO defined. This is used for
 494          * optional GPIOs)
 495          */
 496         if (!fdt_gpio_isvalid(gpio))
 497                 return 0;
 498
 499         if (gpio_request(gpio->gpio, gpio->name))
 500                 return -1;
 501         return 0;
 502 }
 503
 504 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name,
 505                 u8 *array, int count)
 506 {
 507         const u8 *cell;
 508         int err;
 509
 510         cell = get_prop_check_min_len(blob, node, prop_name, count, &err);
 511         if (!err)
 512                 memcpy(array, cell, count);
 513         return err;
 514 }
 515
 516 const u8 *fdtdec_locate_byte_array(const void *blob, int node,
 517                              const char *prop_name, int count)
 518 {
 519         const u8 *cell;
 520         int err;
 521
 522         cell = get_prop_check_min_len(blob, node, prop_name, count, &err);
 523         if (err)
 524                 return NULL;
 525         return cell;
 526 }
 527
 528 int fdtdec_get_config_int(const void *blob, const char *prop_name,
 529                 int default_val)
 530 {
 531         int config_node;
 532
 533         debug("%s: %s\n", __func__, prop_name);
 534         config_node = fdt_path_offset(blob, "/config");
 535         if (config_node < 0)
 536                 return default_val;
 537         return fdtdec_get_int(blob, config_node, prop_name, default_val);
 538 }
 539
 540 int fdtdec_get_config_bool(const void *blob, const char *prop_name)
 541 {
 542         int config_node;
 543         const void *prop;
 544
 545         debug("%s: %s\n", __func__, prop_name);
 546         config_node = fdt_path_offset(blob, "/config");
 547         if (config_node < 0)
 548                 return 0;
 549         prop = fdt_get_property(blob, config_node, prop_name, NULL);
 550
 551         return prop != NULL;
 552 }
 553
 554 char *fdtdec_get_config_string(const void *blob, const char *prop_name)
 555 {
 556         const char *nodep;
 557         int nodeoffset;
 558         int len;
 559
 560         debug("%s: %s\n", __func__, prop_name);
 561         nodeoffset = fdt_path_offset(blob, "/config");
 562         if (nodeoffset < 0)
 563                 return NULL;
 564
 565         nodep = fdt_getprop(blob, nodeoffset, prop_name, &len);
 566         if (!nodep)
 567                 return NULL;
 568
 569         return (char *)nodep;
 570 }
 571
 572 int fdtdec_decode_region(const void *blob, int node,
 573                 const char *prop_name, void **ptrp, size_t *size)
 574 {
 575         const fdt_addr_t *cell;
 576         int len;
 577
 578         debug("%s: %s\n", __func__, prop_name);
 579         cell = fdt_getprop(blob, node, prop_name, &len);
 580         if (!cell || (len != sizeof(fdt_addr_t) * 2))
 581                 return -1;
 582
 583         *ptrp = (void *)fdt_addr_to_cpu(*cell);
 584         *size = fdt_size_to_cpu(cell[1]);
 585         debug("%s: size=%zx\n", __func__, *size);
 586         return 0;
 587 }