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_TEGRA114_I2C, "nvidia,tegra114-i2c"),
  41         COMPAT(NVIDIA_TEGRA20_I2C, "nvidia,tegra20-i2c"),
  42         COMPAT(NVIDIA_TEGRA20_DVC, "nvidia,tegra20-i2c-dvc"),
  43         COMPAT(NVIDIA_TEGRA20_EMC, "nvidia,tegra20-emc"),
  44         COMPAT(NVIDIA_TEGRA20_EMC_TABLE, "nvidia,tegra20-emc-table"),
  45         COMPAT(NVIDIA_TEGRA20_KBC, "nvidia,tegra20-kbc"),
  46         COMPAT(NVIDIA_TEGRA20_NAND, "nvidia,tegra20-nand"),
  47         COMPAT(NVIDIA_TEGRA20_PWM, "nvidia,tegra20-pwm"),
  48         COMPAT(NVIDIA_TEGRA20_DC, "nvidia,tegra20-dc"),
  49         COMPAT(NVIDIA_TEGRA30_SDMMC, "nvidia,tegra30-sdhci"),
  50         COMPAT(NVIDIA_TEGRA20_SDMMC, "nvidia,tegra20-sdhci"),
  51         COMPAT(NVIDIA_TEGRA20_SFLASH, "nvidia,tegra20-sflash"),
  52         COMPAT(NVIDIA_TEGRA20_SLINK, "nvidia,tegra20-slink"),
  53         COMPAT(SMSC_LAN9215, "smsc,lan9215"),
  54         COMPAT(SAMSUNG_EXYNOS5_SROMC, "samsung,exynos-sromc"),
  55         COMPAT(SAMSUNG_S3C2440_I2C, "samsung,s3c2440-i2c"),
  56         COMPAT(SAMSUNG_EXYNOS5_SOUND, "samsung,exynos-sound"),
  57         COMPAT(WOLFSON_WM8994_CODEC, "wolfson,wm8994-codec"),
  58         COMPAT(SAMSUNG_EXYNOS_SPI, "samsung,exynos-spi"),
  59         COMPAT(SAMSUNG_EXYNOS_EHCI, "samsung,exynos-ehci"),
  60         COMPAT(SAMSUNG_EXYNOS_USB_PHY, "samsung,exynos-usb-phy"),
  61         COMPAT(MAXIM_MAX77686_PMIC, "maxim,max77686_pmic"),
  62 };
  63
  64 const char *fdtdec_get_compatible(enum fdt_compat_id id)
  65 {
  66         /* We allow reading of the 'unknown' ID for testing purposes */
  67         assert(id >= 0 && id < COMPAT_COUNT);
  68         return compat_names[id];
  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("%s: %s: ", __func__, 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                 fdt_addr_t addr = fdt_addr_to_cpu(*cell);
  82
  83                 debug("%p\n", (void *)addr);
  84                 return addr;
  85         }
  86         debug("(not found)\n");
  87         return FDT_ADDR_T_NONE;
  88 }
  89
  90 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
  91                 s32 default_val)
  92 {
  93         const s32 *cell;
  94         int len;
  95
  96         debug("%s: %s: ", __func__, prop_name);
  97         cell = fdt_getprop(blob, node, prop_name, &len);
  98         if (cell && len >= sizeof(s32)) {
  99                 s32 val = fdt32_to_cpu(cell[0]);
 100
 101                 debug("%#x (%d)\n", val, val);
 102                 return val;
 103         }
 104         debug("(not found)\n");
 105         return default_val;
 106 }
 107
 108 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
 109                 uint64_t default_val)
 110 {
 111         const uint64_t *cell64;
 112         int length;
 113
 114         cell64 = fdt_getprop(blob, node, prop_name, &length);
 115         if (!cell64 || length < sizeof(*cell64))
 116                 return default_val;
 117
 118         return fdt64_to_cpu(*cell64);
 119 }
 120
 121 int fdtdec_get_is_enabled(const void *blob, int node)
 122 {
 123         const char *cell;
 124
 125         /*
 126          * It should say "okay", so only allow that. Some fdts use "ok" but
 127          * this is a bug. Please fix your device tree source file. See here
 128          * for discussion:
 129          *
 130          * http://www.mail-archive.com/u-boot@lists.denx.de/msg71598.html
 131          */
 132         cell = fdt_getprop(blob, node, "status", NULL);
 133         if (cell)
 134                 return 0 == strcmp(cell, "okay");
 135         return 1;
 136 }
 137
 138 enum fdt_compat_id fdtdec_lookup(const void *blob, int node)
 139 {
 140         enum fdt_compat_id id;
 141
 142         /* Search our drivers */
 143         for (id = COMPAT_UNKNOWN; id < COMPAT_COUNT; id++)
 144                 if (0 == fdt_node_check_compatible(blob, node,
 145                                 compat_names[id]))
 146                         return id;
 147         return COMPAT_UNKNOWN;
 148 }
 149
 150 int fdtdec_next_compatible(const void *blob, int node,
 151                 enum fdt_compat_id id)
 152 {
 153         return fdt_node_offset_by_compatible(blob, node, compat_names[id]);
 154 }
 155
 156 int fdtdec_next_compatible_subnode(const void *blob, int node,
 157                 enum fdt_compat_id id, int *depthp)
 158 {
 159         do {
 160                 node = fdt_next_node(blob, node, depthp);
 161         } while (*depthp > 1);
 162
 163         /* If this is a direct subnode, and compatible, return it */
 164         if (*depthp == 1 && 0 == fdt_node_check_compatible(
 165                                                 blob, node, compat_names[id]))
 166                 return node;
 167
 168         return -FDT_ERR_NOTFOUND;
 169 }
 170
 171 int fdtdec_next_alias(const void *blob, const char *name,
 172                 enum fdt_compat_id id, int *upto)
 173 {
 174 #define MAX_STR_LEN 20
 175         char str[MAX_STR_LEN + 20];
 176         int node, err;
 177
 178         /* snprintf() is not available */
 179         assert(strlen(name) < MAX_STR_LEN);
 180         sprintf(str, "%.*s%d", MAX_STR_LEN, name, *upto);
 181         node = fdt_path_offset(blob, str);
 182         if (node < 0)
 183                 return node;
 184         err = fdt_node_check_compatible(blob, node, compat_names[id]);
 185         if (err < 0)
 186                 return err;
 187         if (err)
 188                 return -FDT_ERR_NOTFOUND;
 189         (*upto)++;
 190         return node;
 191 }
 192
 193 int fdtdec_find_aliases_for_id(const void *blob, const char *name,
 194                         enum fdt_compat_id id, int *node_list, int maxcount)
 195 {
 196         memset(node_list, '\0', sizeof(*node_list) * maxcount);
 197
 198         return fdtdec_add_aliases_for_id(blob, name, id, node_list, maxcount);
 199 }
 200
 201 /* TODO: Can we tighten this code up a little? */
 202 int fdtdec_add_aliases_for_id(const void *blob, const char *name,
 203                         enum fdt_compat_id id, int *node_list, int maxcount)
 204 {
 205         int name_len = strlen(name);
 206         int nodes[maxcount];
 207         int num_found = 0;
 208         int offset, node;
 209         int alias_node;
 210         int count;
 211         int i, j;
 212
 213         /* find the alias node if present */
 214         alias_node = fdt_path_offset(blob, "/aliases");
 215
 216         /*
 217          * start with nothing, and we can assume that the root node can't
 218          * match
 219          */
 220         memset(nodes, '\0', sizeof(nodes));
 221
 222         /* First find all the compatible nodes */
 223         for (node = count = 0; node >= 0 && count < maxcount;) {
 224                 node = fdtdec_next_compatible(blob, node, id);
 225                 if (node >= 0)
 226                         nodes[count++] = node;
 227         }
 228         if (node >= 0)
 229                 debug("%s: warning: maxcount exceeded with alias '%s'\n",
 230                        __func__, name);
 231
 232         /* Now find all the aliases */
 233         for (offset = fdt_first_property_offset(blob, alias_node);
 234                         offset > 0;
 235                         offset = fdt_next_property_offset(blob, offset)) {
 236                 const struct fdt_property *prop;
 237                 const char *path;
 238                 int number;
 239                 int found;
 240
 241                 node = 0;
 242                 prop = fdt_get_property_by_offset(blob, offset, NULL);
 243                 path = fdt_string(blob, fdt32_to_cpu(prop->nameoff));
 244                 if (prop->len && 0 == strncmp(path, name, name_len))
 245                         node = fdt_path_offset(blob, prop->data);
 246                 if (node <= 0)
 247                         continue;
 248
 249                 /* Get the alias number */
 250                 number = simple_strtoul(path + name_len, NULL, 10);
 251                 if (number < 0 || number >= maxcount) {
 252                         debug("%s: warning: alias '%s' is out of range\n",
 253                                __func__, path);
 254                         continue;
 255                 }
 256
 257                 /* Make sure the node we found is actually in our list! */
 258                 found = -1;
 259                 for (j = 0; j < count; j++)
 260                         if (nodes[j] == node) {
 261                                 found = j;
 262                                 break;
 263                         }
 264
 265                 if (found == -1) {
 266                         debug("%s: warning: alias '%s' points to a node "
 267                                 "'%s' that is missing or is not compatible "
 268                                 " with '%s'\n", __func__, path,
 269                                 fdt_get_name(blob, node, NULL),
 270                                compat_names[id]);
 271                         continue;
 272                 }
 273
 274                 /*
 275                  * Add this node to our list in the right place, and mark
 276                  * it as done.
 277                  */
 278                 if (fdtdec_get_is_enabled(blob, node)) {
 279                         if (node_list[number]) {
 280                                 debug("%s: warning: alias '%s' requires that "
 281                                       "a node be placed in the list in a "
 282                                       "position which is already filled by "
 283                                       "node '%s'\n", __func__, path,
 284                                       fdt_get_name(blob, node, NULL));
 285                                 continue;
 286                         }
 287                         node_list[number] = node;
 288                         if (number >= num_found)
 289                                 num_found = number + 1;
 290                 }
 291                 nodes[found] = 0;
 292         }
 293
 294         /* Add any nodes not mentioned by an alias */
 295         for (i = j = 0; i < maxcount; i++) {
 296                 if (!node_list[i]) {
 297                         for (; j < maxcount; j++)
 298                                 if (nodes[j] &&
 299                                         fdtdec_get_is_enabled(blob, nodes[j]))
 300                                         break;
 301
 302                         /* Have we run out of nodes to add? */
 303                         if (j == maxcount)
 304                                 break;
 305
 306                         assert(!node_list[i]);
 307                         node_list[i] = nodes[j++];
 308                         if (i >= num_found)
 309                                 num_found = i + 1;
 310                 }
 311         }
 312
 313         return num_found;
 314 }
 315
 316 int fdtdec_check_fdt(void)
 317 {
 318         /*
 319          * We must have an FDT, but we cannot panic() yet since the console
 320          * is not ready. So for now, just assert(). Boards which need an early
 321          * FDT (prior to console ready) will need to make their own
 322          * arrangements and do their own checks.
 323          */
 324         assert(!fdtdec_prepare_fdt());
 325         return 0;
 326 }
 327
 328 /*
 329  * This function is a little odd in that it accesses global data. At some
 330  * point if the architecture board.c files merge this will make more sense.
 331  * Even now, it is common code.
 332  */
 333 int fdtdec_prepare_fdt(void)
 334 {
 335         if (((uintptr_t)gd->fdt_blob & 3) || fdt_check_header(gd->fdt_blob)) {
 336                 printf("No valid FDT found - please append one to U-Boot "
 337                         "binary, use u-boot-dtb.bin or define "
 338                         "CONFIG_OF_EMBED\n");
 339                 return -1;
 340         }
 341         return 0;
 342 }
 343
 344 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name)
 345 {
 346         const u32 *phandle;
 347         int lookup;
 348
 349         debug("%s: %s\n", __func__, prop_name);
 350         phandle = fdt_getprop(blob, node, prop_name, NULL);
 351         if (!phandle)
 352                 return -FDT_ERR_NOTFOUND;
 353
 354         lookup = fdt_node_offset_by_phandle(blob, fdt32_to_cpu(*phandle));
 355         return lookup;
 356 }
 357
 358 /**
 359  * Look up a property in a node and check that it has a minimum length.
 360  *
 361  * @param blob          FDT blob
 362  * @param node          node to examine
 363  * @param prop_name     name of property to find
 364  * @param min_len       minimum property length in bytes
 365  * @param err           0 if ok, or -FDT_ERR_NOTFOUND if the property is not
 366                         found, or -FDT_ERR_BADLAYOUT if not enough data
 367  * @return pointer to cell, which is only valid if err == 0
 368  */
 369 static const void *get_prop_check_min_len(const void *blob, int node,
 370                 const char *prop_name, int min_len, int *err)
 371 {
 372         const void *cell;
 373         int len;
 374
 375         debug("%s: %s\n", __func__, prop_name);
 376         cell = fdt_getprop(blob, node, prop_name, &len);
 377         if (!cell)
 378                 *err = -FDT_ERR_NOTFOUND;
 379         else if (len < min_len)
 380                 *err = -FDT_ERR_BADLAYOUT;
 381         else
 382                 *err = 0;
 383         return cell;
 384 }
 385
 386 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
 387                 u32 *array, int count)
 388 {
 389         const u32 *cell;
 390         int i, err = 0;
 391
 392         debug("%s: %s\n", __func__, prop_name);
 393         cell = get_prop_check_min_len(blob, node, prop_name,
 394                                       sizeof(u32) * count, &err);
 395         if (!err) {
 396                 for (i = 0; i < count; i++)
 397                         array[i] = fdt32_to_cpu(cell[i]);
 398         }
 399         return err;
 400 }
 401
 402 const u32 *fdtdec_locate_array(const void *blob, int node,
 403                                const char *prop_name, int count)
 404 {
 405         const u32 *cell;
 406         int err;
 407
 408         cell = get_prop_check_min_len(blob, node, prop_name,
 409                                       sizeof(u32) * count, &err);
 410         return err ? NULL : cell;
 411 }
 412
 413 int fdtdec_get_bool(const void *blob, int node, const char *prop_name)
 414 {
 415         const s32 *cell;
 416         int len;
 417
 418         debug("%s: %s\n", __func__, prop_name);
 419         cell = fdt_getprop(blob, node, prop_name, &len);
 420         return cell != NULL;
 421 }
 422
 423 /**
 424  * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no
 425  * terminating item.
 426  *
 427  * @param blob          FDT blob to use
 428  * @param node          Node to look at
 429  * @param prop_name     Node property name
 430  * @param gpio          Array of gpio elements to fill from FDT. This will be
 431  *                      untouched if either 0 or an error is returned
 432  * @param max_count     Maximum number of elements allowed
 433  * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would
 434  * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing.
 435  */
 436 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name,
 437                 struct fdt_gpio_state *gpio, int max_count)
 438 {
 439         const struct fdt_property *prop;
 440         const u32 *cell;
 441         const char *name;
 442         int len, i;
 443
 444         debug("%s: %s\n", __func__, prop_name);
 445         assert(max_count > 0);
 446         prop = fdt_get_property(blob, node, prop_name, &len);
 447         if (!prop) {
 448                 debug("%s: property '%s' missing\n", __func__, prop_name);
 449                 return -FDT_ERR_NOTFOUND;
 450         }
 451
 452         /* We will use the name to tag the GPIO */
 453         name = fdt_string(blob, fdt32_to_cpu(prop->nameoff));
 454         cell = (u32 *)prop->data;
 455         len /= sizeof(u32) * 3;         /* 3 cells per GPIO record */
 456         if (len > max_count) {
 457                 debug(" %s: too many GPIOs / cells for "
 458                         "property '%s'\n", __func__, prop_name);
 459                 return -FDT_ERR_BADLAYOUT;
 460         }
 461
 462         /* Read out the GPIO data from the cells */
 463         for (i = 0; i < len; i++, cell += 3) {
 464                 gpio[i].gpio = fdt32_to_cpu(cell[1]);
 465                 gpio[i].flags = fdt32_to_cpu(cell[2]);
 466                 gpio[i].name = name;
 467         }
 468
 469         return len;
 470 }
 471
 472 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name,
 473                 struct fdt_gpio_state *gpio)
 474 {
 475         int err;
 476
 477         debug("%s: %s\n", __func__, prop_name);
 478         gpio->gpio = FDT_GPIO_NONE;
 479         gpio->name = NULL;
 480         err = fdtdec_decode_gpios(blob, node, prop_name, gpio, 1);
 481         return err == 1 ? 0 : err;
 482 }
 483
 484 int fdtdec_get_gpio(struct fdt_gpio_state *gpio)
 485 {
 486         int val;
 487
 488         if (!fdt_gpio_isvalid(gpio))
 489                 return -1;
 490
 491         val = gpio_get_value(gpio->gpio);
 492         return gpio->flags & FDT_GPIO_ACTIVE_LOW ? val ^ 1 : val;
 493 }
 494
 495 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val)
 496 {
 497         if (!fdt_gpio_isvalid(gpio))
 498                 return -1;
 499
 500         val = gpio->flags & FDT_GPIO_ACTIVE_LOW ? val ^ 1 : val;
 501         return gpio_set_value(gpio->gpio, val);
 502 }
 503
 504 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio)
 505 {
 506         /*
 507          * Return success if there is no GPIO defined. This is used for
 508          * optional GPIOs)
 509          */
 510         if (!fdt_gpio_isvalid(gpio))
 511                 return 0;
 512
 513         if (gpio_request(gpio->gpio, gpio->name))
 514                 return -1;
 515         return 0;
 516 }
 517
 518 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name,
 519                 u8 *array, int count)
 520 {
 521         const u8 *cell;
 522         int err;
 523
 524         cell = get_prop_check_min_len(blob, node, prop_name, count, &err);
 525         if (!err)
 526                 memcpy(array, cell, count);
 527         return err;
 528 }
 529
 530 const u8 *fdtdec_locate_byte_array(const void *blob, int node,
 531                              const char *prop_name, int count)
 532 {
 533         const u8 *cell;
 534         int err;
 535
 536         cell = get_prop_check_min_len(blob, node, prop_name, count, &err);
 537         if (err)
 538                 return NULL;
 539         return cell;
 540 }
 541
 542 int fdtdec_get_config_int(const void *blob, const char *prop_name,
 543                 int default_val)
 544 {
 545         int config_node;
 546
 547         debug("%s: %s\n", __func__, prop_name);
 548         config_node = fdt_path_offset(blob, "/config");
 549         if (config_node < 0)
 550                 return default_val;
 551         return fdtdec_get_int(blob, config_node, prop_name, default_val);
 552 }
 553
 554 int fdtdec_get_config_bool(const void *blob, const char *prop_name)
 555 {
 556         int config_node;
 557         const void *prop;
 558
 559         debug("%s: %s\n", __func__, prop_name);
 560         config_node = fdt_path_offset(blob, "/config");
 561         if (config_node < 0)
 562                 return 0;
 563         prop = fdt_get_property(blob, config_node, prop_name, NULL);
 564
 565         return prop != NULL;
 566 }
 567
 568 char *fdtdec_get_config_string(const void *blob, const char *prop_name)
 569 {
 570         const char *nodep;
 571         int nodeoffset;
 572         int len;
 573
 574         debug("%s: %s\n", __func__, prop_name);
 575         nodeoffset = fdt_path_offset(blob, "/config");
 576         if (nodeoffset < 0)
 577                 return NULL;
 578
 579         nodep = fdt_getprop(blob, nodeoffset, prop_name, &len);
 580         if (!nodep)
 581                 return NULL;
 582
 583         return (char *)nodep;
 584 }
 585
 586 int fdtdec_decode_region(const void *blob, int node,
 587                 const char *prop_name, void **ptrp, size_t *size)
 588 {
 589         const fdt_addr_t *cell;
 590         int len;
 591
 592         debug("%s: %s\n", __func__, prop_name);
 593         cell = fdt_getprop(blob, node, prop_name, &len);
 594         if (!cell || (len != sizeof(fdt_addr_t) * 2))
 595                 return -1;
 596
 597         *ptrp = (void *)fdt_addr_to_cpu(*cell);
 598         *size = fdt_size_to_cpu(cell[1]);
 599         debug("%s: size=%zx\n", __func__, *size);
 600         return 0;
 601 }