arch/sparc/kernel/of_device.c

   1 #include <linux/config.h>
   2 #include <linux/string.h>
   3 #include <linux/kernel.h>
   4 #include <linux/init.h>
   5 #include <linux/module.h>
   6 #include <linux/mod_devicetable.h>
   7 #include <linux/slab.h>
   8
   9 #include <asm/errno.h>
  10 #include <asm/of_device.h>
  11
  12 /**
  13  * of_match_device - Tell if an of_device structure has a matching
  14  * of_match structure
  15  * @ids: array of of device match structures to search in
  16  * @dev: the of device structure to match against
  17  *
  18  * Used by a driver to check whether an of_device present in the
  19  * system is in its list of supported devices.
  20  */
  21 const struct of_device_id *of_match_device(const struct of_device_id *matches,
  22                                         const struct of_device *dev)
  23 {
  24         if (!dev->node)
  25                 return NULL;
  26         while (matches->name[0] || matches->type[0] || matches->compatible[0]) {
  27                 int match = 1;
  28                 if (matches->name[0])
  29                         match &= dev->node->name
  30                                 && !strcmp(matches->name, dev->node->name);
  31                 if (matches->type[0])
  32                         match &= dev->node->type
  33                                 && !strcmp(matches->type, dev->node->type);
  34                 if (matches->compatible[0])
  35                         match &= of_device_is_compatible(dev->node,
  36                                                          matches->compatible);
  37                 if (match)
  38                         return matches;
  39                 matches++;
  40         }
  41         return NULL;
  42 }
  43
  44 static int of_platform_bus_match(struct device *dev, struct device_driver *drv)
  45 {
  46         struct of_device * of_dev = to_of_device(dev);
  47         struct of_platform_driver * of_drv = to_of_platform_driver(drv);
  48         const struct of_device_id * matches = of_drv->match_table;
  49
  50         if (!matches)
  51                 return 0;
  52
  53         return of_match_device(matches, of_dev) != NULL;
  54 }
  55
  56 struct of_device *of_dev_get(struct of_device *dev)
  57 {
  58         struct device *tmp;
  59
  60         if (!dev)
  61                 return NULL;
  62         tmp = get_device(&dev->dev);
  63         if (tmp)
  64                 return to_of_device(tmp);
  65         else
  66                 return NULL;
  67 }
  68
  69 void of_dev_put(struct of_device *dev)
  70 {
  71         if (dev)
  72                 put_device(&dev->dev);
  73 }
  74
  75
  76 static int of_device_probe(struct device *dev)
  77 {
  78         int error = -ENODEV;
  79         struct of_platform_driver *drv;
  80         struct of_device *of_dev;
  81         const struct of_device_id *match;
  82
  83         drv = to_of_platform_driver(dev->driver);
  84         of_dev = to_of_device(dev);
  85
  86         if (!drv->probe)
  87                 return error;
  88
  89         of_dev_get(of_dev);
  90
  91         match = of_match_device(drv->match_table, of_dev);
  92         if (match)
  93                 error = drv->probe(of_dev, match);
  94         if (error)
  95                 of_dev_put(of_dev);
  96
  97         return error;
  98 }
  99
 100 static int of_device_remove(struct device *dev)
 101 {
 102         struct of_device * of_dev = to_of_device(dev);
 103         struct of_platform_driver * drv = to_of_platform_driver(dev->driver);
 104
 105         if (dev->driver && drv->remove)
 106                 drv->remove(of_dev);
 107         return 0;
 108 }
 109
 110 static int of_device_suspend(struct device *dev, pm_message_t state)
 111 {
 112         struct of_device * of_dev = to_of_device(dev);
 113         struct of_platform_driver * drv = to_of_platform_driver(dev->driver);
 114         int error = 0;
 115
 116         if (dev->driver && drv->suspend)
 117                 error = drv->suspend(of_dev, state);
 118         return error;
 119 }
 120
 121 static int of_device_resume(struct device * dev)
 122 {
 123         struct of_device * of_dev = to_of_device(dev);
 124         struct of_platform_driver * drv = to_of_platform_driver(dev->driver);
 125         int error = 0;
 126
 127         if (dev->driver && drv->resume)
 128                 error = drv->resume(of_dev);
 129         return error;
 130 }
 131
 132 static int node_match(struct device *dev, void *data)
 133 {
 134         struct of_device *op = to_of_device(dev);
 135         struct device_node *dp = data;
 136
 137         return (op->node == dp);
 138 }
 139
 140 struct of_device *of_find_device_by_node(struct device_node *dp)
 141 {
 142         struct device *dev = bus_find_device(&of_bus_type, NULL,
 143                                              dp, node_match);
 144
 145         if (dev)
 146                 return to_of_device(dev);
 147
 148         return NULL;
 149 }
 150 EXPORT_SYMBOL(of_find_device_by_node);
 151
 152 #ifdef CONFIG_PCI
 153 struct bus_type ebus_bus_type = {
 154        .name    = "ebus",
 155        .match   = of_platform_bus_match,
 156        .probe   = of_device_probe,
 157        .remove  = of_device_remove,
 158        .suspend = of_device_suspend,
 159        .resume  = of_device_resume,
 160 };
 161 EXPORT_SYMBOL(ebus_bus_type);
 162 #endif
 163
 164 #ifdef CONFIG_SBUS
 165 struct bus_type sbus_bus_type = {
 166        .name    = "sbus",
 167        .match   = of_platform_bus_match,
 168        .probe   = of_device_probe,
 169        .remove  = of_device_remove,
 170        .suspend = of_device_suspend,
 171        .resume  = of_device_resume,
 172 };
 173 EXPORT_SYMBOL(sbus_bus_type);
 174 #endif
 175
 176 struct bus_type of_bus_type = {
 177        .name    = "of",
 178        .match   = of_platform_bus_match,
 179        .probe   = of_device_probe,
 180        .remove  = of_device_remove,
 181        .suspend = of_device_suspend,
 182        .resume  = of_device_resume,
 183 };
 184 EXPORT_SYMBOL(of_bus_type);
 185
 186 static inline u64 of_read_addr(const u32 *cell, int size)
 187 {
 188         u64 r = 0;
 189         while (size--)
 190                 r = (r << 32) | *(cell++);
 191         return r;
 192 }
 193
 194 static void __init get_cells(struct device_node *dp,
 195                              int *addrc, int *sizec)
 196 {
 197         if (addrc)
 198                 *addrc = of_n_addr_cells(dp);
 199         if (sizec)
 200                 *sizec = of_n_size_cells(dp);
 201 }
 202
 203 /* Max address size we deal with */
 204 #define OF_MAX_ADDR_CELLS       4
 205
 206 struct of_bus {
 207         const char      *name;
 208         const char      *addr_prop_name;
 209         int             (*match)(struct device_node *parent);
 210         void            (*count_cells)(struct device_node *child,
 211                                        int *addrc, int *sizec);
 212         int             (*map)(u32 *addr, const u32 *range,
 213                                int na, int ns, int pna);
 214         unsigned int    (*get_flags)(u32 *addr);
 215 };
 216
 217 /*
 218  * Default translator (generic bus)
 219  */
 220
 221 static void of_bus_default_count_cells(struct device_node *dev,
 222                                        int *addrc, int *sizec)
 223 {
 224         get_cells(dev, addrc, sizec);
 225 }
 226
 227 /* Make sure the least significant 64-bits are in-range.  Even
 228  * for 3 or 4 cell values it is a good enough approximation.
 229  */
 230 static int of_out_of_range(const u32 *addr, const u32 *base,
 231                            const u32 *size, int na, int ns)
 232 {
 233         u64 a = of_read_addr(addr, na);
 234         u64 b = of_read_addr(base, na);
 235
 236         if (a < b)
 237                 return 1;
 238
 239         b += of_read_addr(size, ns);
 240         if (a >= b)
 241                 return 1;
 242
 243         return 0;
 244 }
 245
 246 static int of_bus_default_map(u32 *addr, const u32 *range,
 247                               int na, int ns, int pna)
 248 {
 249         u32 result[OF_MAX_ADDR_CELLS];
 250         int i;
 251
 252         if (ns > 2) {
 253                 printk("of_device: Cannot handle size cells (%d) > 2.", ns);
 254                 return -EINVAL;
 255         }
 256
 257         if (of_out_of_range(addr, range, range + na + pna, na, ns))
 258                 return -EINVAL;
 259
 260         /* Start with the parent range base.  */
 261         memcpy(result, range + na, pna * 4);
 262
 263         /* Add in the child address offset.  */
 264         for (i = 0; i < na; i++)
 265                 result[pna - 1 - i] +=
 266                         (addr[na - 1 - i] -
 267                          range[na - 1 - i]);
 268
 269         memcpy(addr, result, pna * 4);
 270
 271         return 0;
 272 }
 273
 274 static unsigned int of_bus_default_get_flags(u32 *addr)
 275 {
 276         return IORESOURCE_MEM;
 277 }
 278
 279 /*
 280  * PCI bus specific translator
 281  */
 282
 283 static int of_bus_pci_match(struct device_node *np)
 284 {
 285         if (!strcmp(np->type, "pci") || !strcmp(np->type, "pciex")) {
 286                 /* Do not do PCI specific frobbing if the
 287                  * PCI bridge lacks a ranges property.  We
 288                  * want to pass it through up to the next
 289                  * parent as-is, not with the PCI translate
 290                  * method which chops off the top address cell.
 291                  */
 292                 if (!of_find_property(np, "ranges", NULL))
 293                         return 0;
 294
 295                 return 1;
 296         }
 297
 298         return 0;
 299 }
 300
 301 static void of_bus_pci_count_cells(struct device_node *np,
 302                                    int *addrc, int *sizec)
 303 {
 304         if (addrc)
 305                 *addrc = 3;
 306         if (sizec)
 307                 *sizec = 2;
 308 }
 309
 310 static int of_bus_pci_map(u32 *addr, const u32 *range,
 311                           int na, int ns, int pna)
 312 {
 313         u32 result[OF_MAX_ADDR_CELLS];
 314         int i;
 315
 316         /* Check address type match */
 317         if ((addr[0] ^ range[0]) & 0x03000000)
 318                 return -EINVAL;
 319
 320         if (of_out_of_range(addr + 1, range + 1, range + na + pna,
 321                             na - 1, ns))
 322                 return -EINVAL;
 323
 324         /* Start with the parent range base.  */
 325         memcpy(result, range + na, pna * 4);
 326
 327         /* Add in the child address offset, skipping high cell.  */
 328         for (i = 0; i < na - 1; i++)
 329                 result[pna - 1 - i] +=
 330                         (addr[na - 1 - i] -
 331                          range[na - 1 - i]);
 332
 333         memcpy(addr, result, pna * 4);
 334
 335         return 0;
 336 }
 337
 338 static unsigned int of_bus_pci_get_flags(u32 *addr)
 339 {
 340         unsigned int flags = 0;
 341         u32 w = addr[0];
 342
 343         switch((w >> 24) & 0x03) {
 344         case 0x01:
 345                 flags |= IORESOURCE_IO;
 346         case 0x02: /* 32 bits */
 347         case 0x03: /* 64 bits */
 348                 flags |= IORESOURCE_MEM;
 349         }
 350         if (w & 0x40000000)
 351                 flags |= IORESOURCE_PREFETCH;
 352         return flags;
 353 }
 354
 355 /*
 356  * SBUS bus specific translator
 357  */
 358
 359 static int of_bus_sbus_match(struct device_node *np)
 360 {
 361         return !strcmp(np->name, "sbus") ||
 362                 !strcmp(np->name, "sbi");
 363 }
 364
 365 static void of_bus_sbus_count_cells(struct device_node *child,
 366                                    int *addrc, int *sizec)
 367 {
 368         if (addrc)
 369                 *addrc = 2;
 370         if (sizec)
 371                 *sizec = 1;
 372 }
 373
 374 static int of_bus_sbus_map(u32 *addr, const u32 *range, int na, int ns, int pna)
 375 {
 376         return of_bus_default_map(addr, range, na, ns, pna);
 377 }
 378
 379 static unsigned int of_bus_sbus_get_flags(u32 *addr)
 380 {
 381         return IORESOURCE_MEM;
 382 }
 383
 384
 385 /*
 386  * Array of bus specific translators
 387  */
 388
 389 static struct of_bus of_busses[] = {
 390         /* PCI */
 391         {
 392                 .name = "pci",
 393                 .addr_prop_name = "assigned-addresses",
 394                 .match = of_bus_pci_match,
 395                 .count_cells = of_bus_pci_count_cells,
 396                 .map = of_bus_pci_map,
 397                 .get_flags = of_bus_pci_get_flags,
 398         },
 399         /* SBUS */
 400         {
 401                 .name = "sbus",
 402                 .addr_prop_name = "reg",
 403                 .match = of_bus_sbus_match,
 404                 .count_cells = of_bus_sbus_count_cells,
 405                 .map = of_bus_sbus_map,
 406                 .get_flags = of_bus_sbus_get_flags,
 407         },
 408         /* Default */
 409         {
 410                 .name = "default",
 411                 .addr_prop_name = "reg",
 412                 .match = NULL,
 413                 .count_cells = of_bus_default_count_cells,
 414                 .map = of_bus_default_map,
 415                 .get_flags = of_bus_default_get_flags,
 416         },
 417 };
 418
 419 static struct of_bus *of_match_bus(struct device_node *np)
 420 {
 421         int i;
 422
 423         for (i = 0; i < ARRAY_SIZE(of_busses); i ++)
 424                 if (!of_busses[i].match || of_busses[i].match(np))
 425                         return &of_busses[i];
 426         BUG();
 427         return NULL;
 428 }
 429
 430 static int __init build_one_resource(struct device_node *parent,
 431                                      struct of_bus *bus,
 432                                      struct of_bus *pbus,
 433                                      u32 *addr,
 434                                      int na, int ns, int pna)
 435 {
 436         u32 *ranges;
 437         unsigned int rlen;
 438         int rone;
 439
 440         ranges = of_get_property(parent, "ranges", &rlen);
 441         if (ranges == NULL || rlen == 0) {
 442                 u32 result[OF_MAX_ADDR_CELLS];
 443                 int i;
 444
 445                 memset(result, 0, pna * 4);
 446                 for (i = 0; i < na; i++)
 447                         result[pna - 1 - i] =
 448                                 addr[na - 1 - i];
 449
 450                 memcpy(addr, result, pna * 4);
 451                 return 0;
 452         }
 453
 454         /* Now walk through the ranges */
 455         rlen /= 4;
 456         rone = na + pna + ns;
 457         for (; rlen >= rone; rlen -= rone, ranges += rone) {
 458                 if (!bus->map(addr, ranges, na, ns, pna))
 459                         return 0;
 460         }
 461
 462         return 1;
 463 }
 464
 465 static int of_resource_verbose;
 466
 467 static void __init build_device_resources(struct of_device *op,
 468                                           struct device *parent)
 469 {
 470         struct of_device *p_op;
 471         struct of_bus *bus;
 472         int na, ns;
 473         int index, num_reg;
 474         void *preg;
 475
 476         if (!parent)
 477                 return;
 478
 479         p_op = to_of_device(parent);
 480         bus = of_match_bus(p_op->node);
 481         bus->count_cells(op->node, &na, &ns);
 482
 483         preg = of_get_property(op->node, bus->addr_prop_name, &num_reg);
 484         if (!preg || num_reg == 0)
 485                 return;
 486
 487         /* Convert to num-cells.  */
 488         num_reg /= 4;
 489
 490         /* Conver to num-entries.  */
 491         num_reg /= na + ns;
 492
 493         for (index = 0; index < num_reg; index++) {
 494                 struct resource *r = &op->resource[index];
 495                 u32 addr[OF_MAX_ADDR_CELLS];
 496                 u32 *reg = (preg + (index * ((na + ns) * 4)));
 497                 struct device_node *dp = op->node;
 498                 struct device_node *pp = p_op->node;
 499                 struct of_bus *pbus;
 500                 u64 size, result = OF_BAD_ADDR;
 501                 unsigned long flags;
 502                 int dna, dns;
 503                 int pna, pns;
 504
 505                 size = of_read_addr(reg + na, ns);
 506                 flags = bus->get_flags(reg);
 507
 508                 memcpy(addr, reg, na * 4);
 509
 510                 /* If the immediate parent has no ranges property to apply,
 511                  * just use a 1<->1 mapping.
 512                  */
 513                 if (of_find_property(pp, "ranges", NULL) == NULL) {
 514                         result = of_read_addr(addr, na);
 515                         goto build_res;
 516                 }
 517
 518                 dna = na;
 519                 dns = ns;
 520
 521                 while (1) {
 522                         dp = pp;
 523                         pp = dp->parent;
 524                         if (!pp) {
 525                                 result = of_read_addr(addr, dna);
 526                                 break;
 527                         }
 528
 529                         pbus = of_match_bus(pp);
 530                         pbus->count_cells(dp, &pna, &pns);
 531
 532                         if (build_one_resource(dp, bus, pbus, addr,
 533                                                dna, dns, pna))
 534                                 break;
 535
 536                         dna = pna;
 537                         dns = pns;
 538                         bus = pbus;
 539                 }
 540
 541         build_res:
 542                 memset(r, 0, sizeof(*r));
 543
 544                 if (of_resource_verbose)
 545                         printk("%s reg[%d] -> %llx\n",
 546                                op->node->full_name, index,
 547                                result);
 548
 549                 if (result != OF_BAD_ADDR) {
 550                         r->start = result & 0xffffffff;
 551                         r->end = result + size - 1;
 552                         r->flags = flags | ((result >> 32ULL) & 0xffUL);
 553                 } else {
 554                         r->start = ~0UL;
 555                         r->end = ~0UL;
 556                 }
 557                 r->name = op->node->name;
 558         }
 559 }
 560
 561 static struct of_device * __init scan_one_device(struct device_node *dp,
 562                                                  struct device *parent)
 563 {
 564         struct of_device *op = kzalloc(sizeof(*op), GFP_KERNEL);
 565         struct linux_prom_irqs *intr;
 566         int len, i;
 567
 568         if (!op)
 569                 return NULL;
 570
 571         op->node = dp;
 572
 573         op->clock_freq = of_getintprop_default(dp, "clock-frequency",
 574                                                (25*1000*1000));
 575         op->portid = of_getintprop_default(dp, "upa-portid", -1);
 576         if (op->portid == -1)
 577                 op->portid = of_getintprop_default(dp, "portid", -1);
 578
 579         intr = of_get_property(dp, "intr", &len);
 580         if (intr) {
 581                 op->num_irqs = len / sizeof(struct linux_prom_irqs);
 582                 for (i = 0; i < op->num_irqs; i++)
 583                         op->irqs[i] = intr[i].pri;
 584         } else {
 585                 unsigned int *irq = of_get_property(dp, "interrupts", &len);
 586
 587                 if (irq) {
 588                         op->num_irqs = len / sizeof(unsigned int);
 589                         for (i = 0; i < op->num_irqs; i++)
 590                                 op->irqs[i] = irq[i];
 591                 } else {
 592                         op->num_irqs = 0;
 593                 }
 594         }
 595         if (sparc_cpu_model == sun4d) {
 596                 static int pil_to_sbus[] = {
 597                         0, 0, 1, 2, 0, 3, 0, 4, 0, 5, 0, 6, 0, 7, 0, 0,
 598                 };
 599                 struct device_node *io_unit, *sbi = dp->parent;
 600                 struct linux_prom_registers *regs;
 601                 int board, slot;
 602
 603                 while (sbi) {
 604                         if (!strcmp(sbi->name, "sbi"))
 605                                 break;
 606
 607                         sbi = sbi->parent;
 608                 }
 609                 if (!sbi)
 610                         goto build_resources;
 611
 612                 regs = of_get_property(dp, "reg", NULL);
 613                 if (!regs)
 614                         goto build_resources;
 615
 616                 slot = regs->which_io;
 617
 618                 /* If SBI's parent is not io-unit or the io-unit lacks
 619                  * a "board#" property, something is very wrong.
 620                  */
 621                 if (!sbi->parent || strcmp(sbi->parent->name, "io-unit")) {
 622                         printk("%s: Error, parent is not io-unit.\n",
 623                                sbi->full_name);
 624                         goto build_resources;
 625                 }
 626                 io_unit = sbi->parent;
 627                 board = of_getintprop_default(io_unit, "board#", -1);
 628                 if (board == -1) {
 629                         printk("%s: Error, lacks board# property.\n",
 630                                io_unit->full_name);
 631                         goto build_resources;
 632                 }
 633
 634                 for (i = 0; i < op->num_irqs; i++) {
 635                         int this_irq = op->irqs[i];
 636                         int sbusl = pil_to_sbus[this_irq];
 637
 638                         if (sbusl)
 639                                 this_irq = (((board + 1) << 5) +
 640                                             (sbusl << 2) +
 641                                             slot);
 642
 643                         op->irqs[i] = this_irq;
 644                 }
 645         }
 646
 647 build_resources:
 648         build_device_resources(op, parent);
 649
 650         op->dev.parent = parent;
 651         op->dev.bus = &of_bus_type;
 652         if (!parent)
 653                 strcpy(op->dev.bus_id, "root");
 654         else
 655                 strcpy(op->dev.bus_id, dp->path_component_name);
 656
 657         if (of_device_register(op)) {
 658                 printk("%s: Could not register of device.\n",
 659                        dp->full_name);
 660                 kfree(op);
 661                 op = NULL;
 662         }
 663
 664         return op;
 665 }
 666
 667 static void __init scan_tree(struct device_node *dp, struct device *parent)
 668 {
 669         while (dp) {
 670                 struct of_device *op = scan_one_device(dp, parent);
 671
 672                 if (op)
 673                         scan_tree(dp->child, &op->dev);
 674
 675                 dp = dp->sibling;
 676         }
 677 }
 678
 679 static void __init scan_of_devices(void)
 680 {
 681         struct device_node *root = of_find_node_by_path("/");
 682         struct of_device *parent;
 683
 684         parent = scan_one_device(root, NULL);
 685         if (!parent)
 686                 return;
 687
 688         scan_tree(root->child, &parent->dev);
 689 }
 690
 691 static int __init of_bus_driver_init(void)
 692 {
 693         int err;
 694
 695         err = bus_register(&of_bus_type);
 696 #ifdef CONFIG_PCI
 697         if (!err)
 698                 err = bus_register(&ebus_bus_type);
 699 #endif
 700 #ifdef CONFIG_SBUS
 701         if (!err)
 702                 err = bus_register(&sbus_bus_type);
 703 #endif
 704
 705         if (!err)
 706                 scan_of_devices();
 707
 708         return err;
 709 }
 710
 711 postcore_initcall(of_bus_driver_init);
 712
 713 static int __init of_debug(char *str)
 714 {
 715         int val = 0;
 716
 717         get_option(&str, &val);
 718         if (val & 1)
 719                 of_resource_verbose = 1;
 720         return 1;
 721 }
 722
 723 __setup("of_debug=", of_debug);
 724
 725 int of_register_driver(struct of_platform_driver *drv, struct bus_type *bus)
 726 {
 727         /* initialize common driver fields */
 728         drv->driver.name = drv->name;
 729         drv->driver.bus = bus;
 730
 731         /* register with core */
 732         return driver_register(&drv->driver);
 733 }
 734
 735 void of_unregister_driver(struct of_platform_driver *drv)
 736 {
 737         driver_unregister(&drv->driver);
 738 }
 739
 740
 741 static ssize_t dev_show_devspec(struct device *dev, struct device_attribute *attr, char *buf)
 742 {
 743         struct of_device *ofdev;
 744
 745         ofdev = to_of_device(dev);
 746         return sprintf(buf, "%s", ofdev->node->full_name);
 747 }
 748
 749 static DEVICE_ATTR(devspec, S_IRUGO, dev_show_devspec, NULL);
 750
 751 /**
 752  * of_release_dev - free an of device structure when all users of it are finished.
 753  * @dev: device that's been disconnected
 754  *
 755  * Will be called only by the device core when all users of this of device are
 756  * done.
 757  */
 758 void of_release_dev(struct device *dev)
 759 {
 760         struct of_device *ofdev;
 761
 762         ofdev = to_of_device(dev);
 763
 764         kfree(ofdev);
 765 }
 766
 767 int of_device_register(struct of_device *ofdev)
 768 {
 769         int rc;
 770
 771         BUG_ON(ofdev->node == NULL);
 772
 773         rc = device_register(&ofdev->dev);
 774         if (rc)
 775                 return rc;
 776
 777         rc = device_create_file(&ofdev->dev, &dev_attr_devspec);
 778         if (rc)
 779                 device_unregister(&ofdev->dev);
 780
 781         return rc;
 782 }
 783
 784 void of_device_unregister(struct of_device *ofdev)
 785 {
 786         device_remove_file(&ofdev->dev, &dev_attr_devspec);
 787         device_unregister(&ofdev->dev);
 788 }
 789
 790 struct of_device* of_platform_device_create(struct device_node *np,
 791                                             const char *bus_id,
 792                                             struct device *parent,
 793                                             struct bus_type *bus)
 794 {
 795         struct of_device *dev;
 796
 797         dev = kmalloc(sizeof(*dev), GFP_KERNEL);
 798         if (!dev)
 799                 return NULL;
 800         memset(dev, 0, sizeof(*dev));
 801
 802         dev->dev.parent = parent;
 803         dev->dev.bus = bus;
 804         dev->dev.release = of_release_dev;
 805
 806         strlcpy(dev->dev.bus_id, bus_id, BUS_ID_SIZE);
 807
 808         if (of_device_register(dev) != 0) {
 809                 kfree(dev);
 810                 return NULL;
 811         }
 812
 813         return dev;
 814 }
 815
 816 EXPORT_SYMBOL(of_match_device);
 817 EXPORT_SYMBOL(of_register_driver);
 818 EXPORT_SYMBOL(of_unregister_driver);
 819 EXPORT_SYMBOL(of_device_register);
 820 EXPORT_SYMBOL(of_device_unregister);
 821 EXPORT_SYMBOL(of_dev_get);
 822 EXPORT_SYMBOL(of_dev_put);
 823 EXPORT_SYMBOL(of_platform_device_create);
 824 EXPORT_SYMBOL(of_release_dev);