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(NVIDIA_TEGRA114_SPI, "nvidia,tegra114-spi"),
  54         COMPAT(SMSC_LAN9215, "smsc,lan9215"),
  55         COMPAT(SAMSUNG_EXYNOS5_SROMC, "samsung,exynos-sromc"),
  56         COMPAT(SAMSUNG_S3C2440_I2C, "samsung,s3c2440-i2c"),
  57         COMPAT(SAMSUNG_EXYNOS5_SOUND, "samsung,exynos-sound"),
  58         COMPAT(WOLFSON_WM8994_CODEC, "wolfson,wm8994-codec"),
  59         COMPAT(SAMSUNG_EXYNOS_SPI, "samsung,exynos-spi"),
  60         COMPAT(SAMSUNG_EXYNOS_EHCI, "samsung,exynos-ehci"),
  61         COMPAT(SAMSUNG_EXYNOS_USB_PHY, "samsung,exynos-usb-phy"),
  62         COMPAT(SAMSUNG_EXYNOS_TMU, "samsung,exynos-tmu"),
  63         COMPAT(MAXIM_MAX77686_PMIC, "maxim,max77686_pmic"),
  64         COMPAT(MAXIM_98095_CODEC, "maxim,max98095-codec"),
  65 };
  66
  67 const char *fdtdec_get_compatible(enum fdt_compat_id id)
  68 {
  69         /* We allow reading of the 'unknown' ID for testing purposes */
  70         assert(id >= 0 && id < COMPAT_COUNT);
  71         return compat_names[id];
  72 }
  73
  74 fdt_addr_t fdtdec_get_addr(const void *blob, int node,
  75                 const char *prop_name)
  76 {
  77         const fdt_addr_t *cell;
  78         int len;
  79
  80         debug("%s: %s: ", __func__, prop_name);
  81         cell = fdt_getprop(blob, node, prop_name, &len);
  82         if (cell && (len == sizeof(fdt_addr_t) ||
  83                         len == sizeof(fdt_addr_t) * 2)) {
  84                 fdt_addr_t addr = fdt_addr_to_cpu(*cell);
  85
  86                 debug("%p\n", (void *)addr);
  87                 return addr;
  88         }
  89         debug("(not found)\n");
  90         return FDT_ADDR_T_NONE;
  91 }
  92
  93 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
  94                 s32 default_val)
  95 {
  96         const s32 *cell;
  97         int len;
  98
  99         debug("%s: %s: ", __func__, prop_name);
 100         cell = fdt_getprop(blob, node, prop_name, &len);
 101         if (cell && len >= sizeof(s32)) {
 102                 s32 val = fdt32_to_cpu(cell[0]);
 103
 104                 debug("%#x (%d)\n", val, val);
 105                 return val;
 106         }
 107         debug("(not found)\n");
 108         return default_val;
 109 }
 110
 111 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
 112                 uint64_t default_val)
 113 {
 114         const uint64_t *cell64;
 115         int length;
 116
 117         cell64 = fdt_getprop(blob, node, prop_name, &length);
 118         if (!cell64 || length < sizeof(*cell64))
 119                 return default_val;
 120
 121         return fdt64_to_cpu(*cell64);
 122 }
 123
 124 int fdtdec_get_is_enabled(const void *blob, int node)
 125 {
 126         const char *cell;
 127
 128         /*
 129          * It should say "okay", so only allow that. Some fdts use "ok" but
 130          * this is a bug. Please fix your device tree source file. See here
 131          * for discussion:
 132          *
 133          * http://www.mail-archive.com/u-boot@lists.denx.de/msg71598.html
 134          */
 135         cell = fdt_getprop(blob, node, "status", NULL);
 136         if (cell)
 137                 return 0 == strcmp(cell, "okay");
 138         return 1;
 139 }
 140
 141 enum fdt_compat_id fdtdec_lookup(const void *blob, int node)
 142 {
 143         enum fdt_compat_id id;
 144
 145         /* Search our drivers */
 146         for (id = COMPAT_UNKNOWN; id < COMPAT_COUNT; id++)
 147                 if (0 == fdt_node_check_compatible(blob, node,
 148                                 compat_names[id]))
 149                         return id;
 150         return COMPAT_UNKNOWN;
 151 }
 152
 153 int fdtdec_next_compatible(const void *blob, int node,
 154                 enum fdt_compat_id id)
 155 {
 156         return fdt_node_offset_by_compatible(blob, node, compat_names[id]);
 157 }
 158
 159 int fdtdec_next_compatible_subnode(const void *blob, int node,
 160                 enum fdt_compat_id id, int *depthp)
 161 {
 162         do {
 163                 node = fdt_next_node(blob, node, depthp);
 164         } while (*depthp > 1);
 165
 166         /* If this is a direct subnode, and compatible, return it */
 167         if (*depthp == 1 && 0 == fdt_node_check_compatible(
 168                                                 blob, node, compat_names[id]))
 169                 return node;
 170
 171         return -FDT_ERR_NOTFOUND;
 172 }
 173
 174 int fdtdec_next_alias(const void *blob, const char *name,
 175                 enum fdt_compat_id id, int *upto)
 176 {
 177 #define MAX_STR_LEN 20
 178         char str[MAX_STR_LEN + 20];
 179         int node, err;
 180
 181         /* snprintf() is not available */
 182         assert(strlen(name) < MAX_STR_LEN);
 183         sprintf(str, "%.*s%d", MAX_STR_LEN, name, *upto);
 184         node = fdt_path_offset(blob, str);
 185         if (node < 0)
 186                 return node;
 187         err = fdt_node_check_compatible(blob, node, compat_names[id]);
 188         if (err < 0)
 189                 return err;
 190         if (err)
 191                 return -FDT_ERR_NOTFOUND;
 192         (*upto)++;
 193         return node;
 194 }
 195
 196 int fdtdec_find_aliases_for_id(const void *blob, const char *name,
 197                         enum fdt_compat_id id, int *node_list, int maxcount)
 198 {
 199         memset(node_list, '\0', sizeof(*node_list) * maxcount);
 200
 201         return fdtdec_add_aliases_for_id(blob, name, id, node_list, maxcount);
 202 }
 203
 204 /* TODO: Can we tighten this code up a little? */
 205 int fdtdec_add_aliases_for_id(const void *blob, const char *name,
 206                         enum fdt_compat_id id, int *node_list, int maxcount)
 207 {
 208         int name_len = strlen(name);
 209         int nodes[maxcount];
 210         int num_found = 0;
 211         int offset, node;
 212         int alias_node;
 213         int count;
 214         int i, j;
 215
 216         /* find the alias node if present */
 217         alias_node = fdt_path_offset(blob, "/aliases");
 218
 219         /*
 220          * start with nothing, and we can assume that the root node can't
 221          * match
 222          */
 223         memset(nodes, '\0', sizeof(nodes));
 224
 225         /* First find all the compatible nodes */
 226         for (node = count = 0; node >= 0 && count < maxcount;) {
 227                 node = fdtdec_next_compatible(blob, node, id);
 228                 if (node >= 0)
 229                         nodes[count++] = node;
 230         }
 231         if (node >= 0)
 232                 debug("%s: warning: maxcount exceeded with alias '%s'\n",
 233                        __func__, name);
 234
 235         /* Now find all the aliases */
 236         for (offset = fdt_first_property_offset(blob, alias_node);
 237                         offset > 0;
 238                         offset = fdt_next_property_offset(blob, offset)) {
 239                 const struct fdt_property *prop;
 240                 const char *path;
 241                 int number;
 242                 int found;
 243
 244                 node = 0;
 245                 prop = fdt_get_property_by_offset(blob, offset, NULL);
 246                 path = fdt_string(blob, fdt32_to_cpu(prop->nameoff));
 247                 if (prop->len && 0 == strncmp(path, name, name_len))
 248                         node = fdt_path_offset(blob, prop->data);
 249                 if (node <= 0)
 250                         continue;
 251
 252                 /* Get the alias number */
 253                 number = simple_strtoul(path + name_len, NULL, 10);
 254                 if (number < 0 || number >= maxcount) {
 255                         debug("%s: warning: alias '%s' is out of range\n",
 256                                __func__, path);
 257                         continue;
 258                 }
 259
 260                 /* Make sure the node we found is actually in our list! */
 261                 found = -1;
 262                 for (j = 0; j < count; j++)
 263                         if (nodes[j] == node) {
 264                                 found = j;
 265                                 break;
 266                         }
 267
 268                 if (found == -1) {
 269                         debug("%s: warning: alias '%s' points to a node "
 270                                 "'%s' that is missing or is not compatible "
 271                                 " with '%s'\n", __func__, path,
 272                                 fdt_get_name(blob, node, NULL),
 273                                compat_names[id]);
 274                         continue;
 275                 }
 276
 277                 /*
 278                  * Add this node to our list in the right place, and mark
 279                  * it as done.
 280                  */
 281                 if (fdtdec_get_is_enabled(blob, node)) {
 282                         if (node_list[number]) {
 283                                 debug("%s: warning: alias '%s' requires that "
 284                                       "a node be placed in the list in a "
 285                                       "position which is already filled by "
 286                                       "node '%s'\n", __func__, path,
 287                                       fdt_get_name(blob, node, NULL));
 288                                 continue;
 289                         }
 290                         node_list[number] = node;
 291                         if (number >= num_found)
 292                                 num_found = number + 1;
 293                 }
 294                 nodes[found] = 0;
 295         }
 296
 297         /* Add any nodes not mentioned by an alias */
 298         for (i = j = 0; i < maxcount; i++) {
 299                 if (!node_list[i]) {
 300                         for (; j < maxcount; j++)
 301                                 if (nodes[j] &&
 302                                         fdtdec_get_is_enabled(blob, nodes[j]))
 303                                         break;
 304
 305                         /* Have we run out of nodes to add? */
 306                         if (j == maxcount)
 307                                 break;
 308
 309                         assert(!node_list[i]);
 310                         node_list[i] = nodes[j++];
 311                         if (i >= num_found)
 312                                 num_found = i + 1;
 313                 }
 314         }
 315
 316         return num_found;
 317 }
 318
 319 int fdtdec_check_fdt(void)
 320 {
 321         /*
 322          * We must have an FDT, but we cannot panic() yet since the console
 323          * is not ready. So for now, just assert(). Boards which need an early
 324          * FDT (prior to console ready) will need to make their own
 325          * arrangements and do their own checks.
 326          */
 327         assert(!fdtdec_prepare_fdt());
 328         return 0;
 329 }
 330
 331 /*
 332  * This function is a little odd in that it accesses global data. At some
 333  * point if the architecture board.c files merge this will make more sense.
 334  * Even now, it is common code.
 335  */
 336 int fdtdec_prepare_fdt(void)
 337 {
 338         if (((uintptr_t)gd->fdt_blob & 3) || fdt_check_header(gd->fdt_blob)) {
 339                 printf("No valid FDT found - please append one to U-Boot "
 340                         "binary, use u-boot-dtb.bin or define "
 341                         "CONFIG_OF_EMBED\n");
 342                 return -1;
 343         }
 344         return 0;
 345 }
 346
 347 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name)
 348 {
 349         const u32 *phandle;
 350         int lookup;
 351
 352         debug("%s: %s\n", __func__, prop_name);
 353         phandle = fdt_getprop(blob, node, prop_name, NULL);
 354         if (!phandle)
 355                 return -FDT_ERR_NOTFOUND;
 356
 357         lookup = fdt_node_offset_by_phandle(blob, fdt32_to_cpu(*phandle));
 358         return lookup;
 359 }
 360
 361 /**
 362  * Look up a property in a node and check that it has a minimum length.
 363  *
 364  * @param blob          FDT blob
 365  * @param node          node to examine
 366  * @param prop_name     name of property to find
 367  * @param min_len       minimum property length in bytes
 368  * @param err           0 if ok, or -FDT_ERR_NOTFOUND if the property is not
 369                         found, or -FDT_ERR_BADLAYOUT if not enough data
 370  * @return pointer to cell, which is only valid if err == 0
 371  */
 372 static const void *get_prop_check_min_len(const void *blob, int node,
 373                 const char *prop_name, int min_len, int *err)
 374 {
 375         const void *cell;
 376         int len;
 377
 378         debug("%s: %s\n", __func__, prop_name);
 379         cell = fdt_getprop(blob, node, prop_name, &len);
 380         if (!cell)
 381                 *err = -FDT_ERR_NOTFOUND;
 382         else if (len < min_len)
 383                 *err = -FDT_ERR_BADLAYOUT;
 384         else
 385                 *err = 0;
 386         return cell;
 387 }
 388
 389 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
 390                 u32 *array, int count)
 391 {
 392         const u32 *cell;
 393         int i, err = 0;
 394
 395         debug("%s: %s\n", __func__, prop_name);
 396         cell = get_prop_check_min_len(blob, node, prop_name,
 397                                       sizeof(u32) * count, &err);
 398         if (!err) {
 399                 for (i = 0; i < count; i++)
 400                         array[i] = fdt32_to_cpu(cell[i]);
 401         }
 402         return err;
 403 }
 404
 405 const u32 *fdtdec_locate_array(const void *blob, int node,
 406                                const char *prop_name, int count)
 407 {
 408         const u32 *cell;
 409         int err;
 410
 411         cell = get_prop_check_min_len(blob, node, prop_name,
 412                                       sizeof(u32) * count, &err);
 413         return err ? NULL : cell;
 414 }
 415
 416 int fdtdec_get_bool(const void *blob, int node, const char *prop_name)
 417 {
 418         const s32 *cell;
 419         int len;
 420
 421         debug("%s: %s\n", __func__, prop_name);
 422         cell = fdt_getprop(blob, node, prop_name, &len);
 423         return cell != NULL;
 424 }
 425
 426 /**
 427  * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no
 428  * terminating item.
 429  *
 430  * @param blob          FDT blob to use
 431  * @param node          Node to look at
 432  * @param prop_name     Node property name
 433  * @param gpio          Array of gpio elements to fill from FDT. This will be
 434  *                      untouched if either 0 or an error is returned
 435  * @param max_count     Maximum number of elements allowed
 436  * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would
 437  * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing.
 438  */
 439 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name,
 440                 struct fdt_gpio_state *gpio, int max_count)
 441 {
 442         const struct fdt_property *prop;
 443         const u32 *cell;
 444         const char *name;
 445         int len, i;
 446
 447         debug("%s: %s\n", __func__, prop_name);
 448         assert(max_count > 0);
 449         prop = fdt_get_property(blob, node, prop_name, &len);
 450         if (!prop) {
 451                 debug("%s: property '%s' missing\n", __func__, prop_name);
 452                 return -FDT_ERR_NOTFOUND;
 453         }
 454
 455         /* We will use the name to tag the GPIO */
 456         name = fdt_string(blob, fdt32_to_cpu(prop->nameoff));
 457         cell = (u32 *)prop->data;
 458         len /= sizeof(u32) * 3;         /* 3 cells per GPIO record */
 459         if (len > max_count) {
 460                 debug(" %s: too many GPIOs / cells for "
 461                         "property '%s'\n", __func__, prop_name);
 462                 return -FDT_ERR_BADLAYOUT;
 463         }
 464
 465         /* Read out the GPIO data from the cells */
 466         for (i = 0; i < len; i++, cell += 3) {
 467                 gpio[i].gpio = fdt32_to_cpu(cell[1]);
 468                 gpio[i].flags = fdt32_to_cpu(cell[2]);
 469                 gpio[i].name = name;
 470         }
 471
 472         return len;
 473 }
 474
 475 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name,
 476                 struct fdt_gpio_state *gpio)
 477 {
 478         int err;
 479
 480         debug("%s: %s\n", __func__, prop_name);
 481         gpio->gpio = FDT_GPIO_NONE;
 482         gpio->name = NULL;
 483         err = fdtdec_decode_gpios(blob, node, prop_name, gpio, 1);
 484         return err == 1 ? 0 : err;
 485 }
 486
 487 int fdtdec_get_gpio(struct fdt_gpio_state *gpio)
 488 {
 489         int val;
 490
 491         if (!fdt_gpio_isvalid(gpio))
 492                 return -1;
 493
 494         val = gpio_get_value(gpio->gpio);
 495         return gpio->flags & FDT_GPIO_ACTIVE_LOW ? val ^ 1 : val;
 496 }
 497
 498 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val)
 499 {
 500         if (!fdt_gpio_isvalid(gpio))
 501                 return -1;
 502
 503         val = gpio->flags & FDT_GPIO_ACTIVE_LOW ? val ^ 1 : val;
 504         return gpio_set_value(gpio->gpio, val);
 505 }
 506
 507 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio)
 508 {
 509         /*
 510          * Return success if there is no GPIO defined. This is used for
 511          * optional GPIOs)
 512          */
 513         if (!fdt_gpio_isvalid(gpio))
 514                 return 0;
 515
 516         if (gpio_request(gpio->gpio, gpio->name))
 517                 return -1;
 518         return 0;
 519 }
 520
 521 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name,
 522                 u8 *array, int count)
 523 {
 524         const u8 *cell;
 525         int err;
 526
 527         cell = get_prop_check_min_len(blob, node, prop_name, count, &err);
 528         if (!err)
 529                 memcpy(array, cell, count);
 530         return err;
 531 }
 532
 533 const u8 *fdtdec_locate_byte_array(const void *blob, int node,
 534                              const char *prop_name, int count)
 535 {
 536         const u8 *cell;
 537         int err;
 538
 539         cell = get_prop_check_min_len(blob, node, prop_name, count, &err);
 540         if (err)
 541                 return NULL;
 542         return cell;
 543 }
 544
 545 int fdtdec_get_config_int(const void *blob, const char *prop_name,
 546                 int default_val)
 547 {
 548         int config_node;
 549
 550         debug("%s: %s\n", __func__, prop_name);
 551         config_node = fdt_path_offset(blob, "/config");
 552         if (config_node < 0)
 553                 return default_val;
 554         return fdtdec_get_int(blob, config_node, prop_name, default_val);
 555 }
 556
 557 int fdtdec_get_config_bool(const void *blob, const char *prop_name)
 558 {
 559         int config_node;
 560         const void *prop;
 561
 562         debug("%s: %s\n", __func__, prop_name);
 563         config_node = fdt_path_offset(blob, "/config");
 564         if (config_node < 0)
 565                 return 0;
 566         prop = fdt_get_property(blob, config_node, prop_name, NULL);
 567
 568         return prop != NULL;
 569 }
 570
 571 char *fdtdec_get_config_string(const void *blob, const char *prop_name)
 572 {
 573         const char *nodep;
 574         int nodeoffset;
 575         int len;
 576
 577         debug("%s: %s\n", __func__, prop_name);
 578         nodeoffset = fdt_path_offset(blob, "/config");
 579         if (nodeoffset < 0)
 580                 return NULL;
 581
 582         nodep = fdt_getprop(blob, nodeoffset, prop_name, &len);
 583         if (!nodep)
 584                 return NULL;
 585
 586         return (char *)nodep;
 587 }
 588
 589 int fdtdec_decode_region(const void *blob, int node,
 590                 const char *prop_name, void **ptrp, size_t *size)
 591 {
 592         const fdt_addr_t *cell;
 593         int len;
 594
 595         debug("%s: %s\n", __func__, prop_name);
 596         cell = fdt_getprop(blob, node, prop_name, &len);
 597         if (!cell || (len != sizeof(fdt_addr_t) * 2))
 598                 return -1;
 599
 600         *ptrp = (void *)fdt_addr_to_cpu(*cell);
 601         *size = fdt_size_to_cpu(cell[1]);
 602         debug("%s: size=%zx\n", __func__, *size);
 603         return 0;
 604 }