arch/sparc/kernel/of_device.c

   1 #include <linux/string.h>
   2 #include <linux/kernel.h>
   3 #include <linux/init.h>
   4 #include <linux/module.h>
   5 #include <linux/mod_devicetable.h>
   6 #include <linux/slab.h>
   7
   8 #include <asm/errno.h>
   9 #include <asm/of_device.h>
  10
  11 /**
  12  * of_match_device - Tell if an of_device structure has a matching
  13  * of_match structure
  14  * @ids: array of of device match structures to search in
  15  * @dev: the of device structure to match against
  16  *
  17  * Used by a driver to check whether an of_device present in the
  18  * system is in its list of supported devices.
  19  */
  20 const struct of_device_id *of_match_device(const struct of_device_id *matches,
  21                                         const struct of_device *dev)
  22 {
  23         if (!dev->node)
  24                 return NULL;
  25         while (matches->name[0] || matches->type[0] || matches->compatible[0]) {
  26                 int match = 1;
  27                 if (matches->name[0])
  28                         match &= dev->node->name
  29                                 && !strcmp(matches->name, dev->node->name);
  30                 if (matches->type[0])
  31                         match &= dev->node->type
  32                                 && !strcmp(matches->type, dev->node->type);
  33                 if (matches->compatible[0])
  34                         match &= of_device_is_compatible(dev->node,
  35                                                          matches->compatible);
  36                 if (match)
  37                         return matches;
  38                 matches++;
  39         }
  40         return NULL;
  41 }
  42
  43 static int of_platform_bus_match(struct device *dev, struct device_driver *drv)
  44 {
  45         struct of_device * of_dev = to_of_device(dev);
  46         struct of_platform_driver * of_drv = to_of_platform_driver(drv);
  47         const struct of_device_id * matches = of_drv->match_table;
  48
  49         if (!matches)
  50                 return 0;
  51
  52         return of_match_device(matches, of_dev) != NULL;
  53 }
  54
  55 struct of_device *of_dev_get(struct of_device *dev)
  56 {
  57         struct device *tmp;
  58
  59         if (!dev)
  60                 return NULL;
  61         tmp = get_device(&dev->dev);
  62         if (tmp)
  63                 return to_of_device(tmp);
  64         else
  65                 return NULL;
  66 }
  67
  68 void of_dev_put(struct of_device *dev)
  69 {
  70         if (dev)
  71                 put_device(&dev->dev);
  72 }
  73
  74
  75 static int of_device_probe(struct device *dev)
  76 {
  77         int error = -ENODEV;
  78         struct of_platform_driver *drv;
  79         struct of_device *of_dev;
  80         const struct of_device_id *match;
  81
  82         drv = to_of_platform_driver(dev->driver);
  83         of_dev = to_of_device(dev);
  84
  85         if (!drv->probe)
  86                 return error;
  87
  88         of_dev_get(of_dev);
  89
  90         match = of_match_device(drv->match_table, of_dev);
  91         if (match)
  92                 error = drv->probe(of_dev, match);
  93         if (error)
  94                 of_dev_put(of_dev);
  95
  96         return error;
  97 }
  98
  99 static int of_device_remove(struct device *dev)
 100 {
 101         struct of_device * of_dev = to_of_device(dev);
 102         struct of_platform_driver * drv = to_of_platform_driver(dev->driver);
 103
 104         if (dev->driver && drv->remove)
 105                 drv->remove(of_dev);
 106         return 0;
 107 }
 108
 109 static int of_device_suspend(struct device *dev, pm_message_t state)
 110 {
 111         struct of_device * of_dev = to_of_device(dev);
 112         struct of_platform_driver * drv = to_of_platform_driver(dev->driver);
 113         int error = 0;
 114
 115         if (dev->driver && drv->suspend)
 116                 error = drv->suspend(of_dev, state);
 117         return error;
 118 }
 119
 120 static int of_device_resume(struct device * dev)
 121 {
 122         struct of_device * of_dev = to_of_device(dev);
 123         struct of_platform_driver * drv = to_of_platform_driver(dev->driver);
 124         int error = 0;
 125
 126         if (dev->driver && drv->resume)
 127                 error = drv->resume(of_dev);
 128         return error;
 129 }
 130
 131 static int node_match(struct device *dev, void *data)
 132 {
 133         struct of_device *op = to_of_device(dev);
 134         struct device_node *dp = data;
 135
 136         return (op->node == dp);
 137 }
 138
 139 struct of_device *of_find_device_by_node(struct device_node *dp)
 140 {
 141         struct device *dev = bus_find_device(&of_bus_type, NULL,
 142                                              dp, node_match);
 143
 144         if (dev)
 145                 return to_of_device(dev);
 146
 147         return NULL;
 148 }
 149 EXPORT_SYMBOL(of_find_device_by_node);
 150
 151 #ifdef CONFIG_PCI
 152 struct bus_type ebus_bus_type = {
 153        .name    = "ebus",
 154        .match   = of_platform_bus_match,
 155        .probe   = of_device_probe,
 156        .remove  = of_device_remove,
 157        .suspend = of_device_suspend,
 158        .resume  = of_device_resume,
 159 };
 160 EXPORT_SYMBOL(ebus_bus_type);
 161 #endif
 162
 163 #ifdef CONFIG_SBUS
 164 struct bus_type sbus_bus_type = {
 165        .name    = "sbus",
 166        .match   = of_platform_bus_match,
 167        .probe   = of_device_probe,
 168        .remove  = of_device_remove,
 169        .suspend = of_device_suspend,
 170        .resume  = of_device_resume,
 171 };
 172 EXPORT_SYMBOL(sbus_bus_type);
 173 #endif
 174
 175 struct bus_type of_bus_type = {
 176        .name    = "of",
 177        .match   = of_platform_bus_match,
 178        .probe   = of_device_probe,
 179        .remove  = of_device_remove,
 180        .suspend = of_device_suspend,
 181        .resume  = of_device_resume,
 182 };
 183 EXPORT_SYMBOL(of_bus_type);
 184
 185 static inline u64 of_read_addr(const u32 *cell, int size)
 186 {
 187         u64 r = 0;
 188         while (size--)
 189                 r = (r << 32) | *(cell++);
 190         return r;
 191 }
 192
 193 static void __init get_cells(struct device_node *dp,
 194                              int *addrc, int *sizec)
 195 {
 196         if (addrc)
 197                 *addrc = of_n_addr_cells(dp);
 198         if (sizec)
 199                 *sizec = of_n_size_cells(dp);
 200 }
 201
 202 /* Max address size we deal with */
 203 #define OF_MAX_ADDR_CELLS       4
 204
 205 struct of_bus {
 206         const char      *name;
 207         const char      *addr_prop_name;
 208         int             (*match)(struct device_node *parent);
 209         void            (*count_cells)(struct device_node *child,
 210                                        int *addrc, int *sizec);
 211         int             (*map)(u32 *addr, const u32 *range,
 212                                int na, int ns, int pna);
 213         unsigned int    (*get_flags)(u32 *addr);
 214 };
 215
 216 /*
 217  * Default translator (generic bus)
 218  */
 219
 220 static void of_bus_default_count_cells(struct device_node *dev,
 221                                        int *addrc, int *sizec)
 222 {
 223         get_cells(dev, addrc, sizec);
 224 }
 225
 226 /* Make sure the least significant 64-bits are in-range.  Even
 227  * for 3 or 4 cell values it is a good enough approximation.
 228  */
 229 static int of_out_of_range(const u32 *addr, const u32 *base,
 230                            const u32 *size, int na, int ns)
 231 {
 232         u64 a = of_read_addr(addr, na);
 233         u64 b = of_read_addr(base, na);
 234
 235         if (a < b)
 236                 return 1;
 237
 238         b += of_read_addr(size, ns);
 239         if (a >= b)
 240                 return 1;
 241
 242         return 0;
 243 }
 244
 245 static int of_bus_default_map(u32 *addr, const u32 *range,
 246                               int na, int ns, int pna)
 247 {
 248         u32 result[OF_MAX_ADDR_CELLS];
 249         int i;
 250
 251         if (ns > 2) {
 252                 printk("of_device: Cannot handle size cells (%d) > 2.", ns);
 253                 return -EINVAL;
 254         }
 255
 256         if (of_out_of_range(addr, range, range + na + pna, na, ns))
 257                 return -EINVAL;
 258
 259         /* Start with the parent range base.  */
 260         memcpy(result, range + na, pna * 4);
 261
 262         /* Add in the child address offset.  */
 263         for (i = 0; i < na; i++)
 264                 result[pna - 1 - i] +=
 265                         (addr[na - 1 - i] -
 266                          range[na - 1 - i]);
 267
 268         memcpy(addr, result, pna * 4);
 269
 270         return 0;
 271 }
 272
 273 static unsigned int of_bus_default_get_flags(u32 *addr)
 274 {
 275         return IORESOURCE_MEM;
 276 }
 277
 278 /*
 279  * PCI bus specific translator
 280  */
 281
 282 static int of_bus_pci_match(struct device_node *np)
 283 {
 284         if (!strcmp(np->type, "pci") || !strcmp(np->type, "pciex")) {
 285                 /* Do not do PCI specific frobbing if the
 286                  * PCI bridge lacks a ranges property.  We
 287                  * want to pass it through up to the next
 288                  * parent as-is, not with the PCI translate
 289                  * method which chops off the top address cell.
 290                  */
 291                 if (!of_find_property(np, "ranges", NULL))
 292                         return 0;
 293
 294                 return 1;
 295         }
 296
 297         return 0;
 298 }
 299
 300 static void of_bus_pci_count_cells(struct device_node *np,
 301                                    int *addrc, int *sizec)
 302 {
 303         if (addrc)
 304                 *addrc = 3;
 305         if (sizec)
 306                 *sizec = 2;
 307 }
 308
 309 static int of_bus_pci_map(u32 *addr, const u32 *range,
 310                           int na, int ns, int pna)
 311 {
 312         u32 result[OF_MAX_ADDR_CELLS];
 313         int i;
 314
 315         /* Check address type match */
 316         if ((addr[0] ^ range[0]) & 0x03000000)
 317                 return -EINVAL;
 318
 319         if (of_out_of_range(addr + 1, range + 1, range + na + pna,
 320                             na - 1, ns))
 321                 return -EINVAL;
 322
 323         /* Start with the parent range base.  */
 324         memcpy(result, range + na, pna * 4);
 325
 326         /* Add in the child address offset, skipping high cell.  */
 327         for (i = 0; i < na - 1; i++)
 328                 result[pna - 1 - i] +=
 329                         (addr[na - 1 - i] -
 330                          range[na - 1 - i]);
 331
 332         memcpy(addr, result, pna * 4);
 333
 334         return 0;
 335 }
 336
 337 static unsigned int of_bus_pci_get_flags(u32 *addr)
 338 {
 339         unsigned int flags = 0;
 340         u32 w = addr[0];
 341
 342         switch((w >> 24) & 0x03) {
 343         case 0x01:
 344                 flags |= IORESOURCE_IO;
 345         case 0x02: /* 32 bits */
 346         case 0x03: /* 64 bits */
 347                 flags |= IORESOURCE_MEM;
 348         }
 349         if (w & 0x40000000)
 350                 flags |= IORESOURCE_PREFETCH;
 351         return flags;
 352 }
 353
 354 /*
 355  * SBUS bus specific translator
 356  */
 357
 358 static int of_bus_sbus_match(struct device_node *np)
 359 {
 360         return !strcmp(np->name, "sbus") ||
 361                 !strcmp(np->name, "sbi");
 362 }
 363
 364 static void of_bus_sbus_count_cells(struct device_node *child,
 365                                    int *addrc, int *sizec)
 366 {
 367         if (addrc)
 368                 *addrc = 2;
 369         if (sizec)
 370                 *sizec = 1;
 371 }
 372
 373 static int of_bus_sbus_map(u32 *addr, const u32 *range, int na, int ns, int pna)
 374 {
 375         return of_bus_default_map(addr, range, na, ns, pna);
 376 }
 377
 378 static unsigned int of_bus_sbus_get_flags(u32 *addr)
 379 {
 380         return IORESOURCE_MEM;
 381 }
 382
 383
 384 /*
 385  * Array of bus specific translators
 386  */
 387
 388 static struct of_bus of_busses[] = {
 389         /* PCI */
 390         {
 391                 .name = "pci",
 392                 .addr_prop_name = "assigned-addresses",
 393                 .match = of_bus_pci_match,
 394                 .count_cells = of_bus_pci_count_cells,
 395                 .map = of_bus_pci_map,
 396                 .get_flags = of_bus_pci_get_flags,
 397         },
 398         /* SBUS */
 399         {
 400                 .name = "sbus",
 401                 .addr_prop_name = "reg",
 402                 .match = of_bus_sbus_match,
 403                 .count_cells = of_bus_sbus_count_cells,
 404                 .map = of_bus_sbus_map,
 405                 .get_flags = of_bus_sbus_get_flags,
 406         },
 407         /* Default */
 408         {
 409                 .name = "default",
 410                 .addr_prop_name = "reg",
 411                 .match = NULL,
 412                 .count_cells = of_bus_default_count_cells,
 413                 .map = of_bus_default_map,
 414                 .get_flags = of_bus_default_get_flags,
 415         },
 416 };
 417
 418 static struct of_bus *of_match_bus(struct device_node *np)
 419 {
 420         int i;
 421
 422         for (i = 0; i < ARRAY_SIZE(of_busses); i ++)
 423                 if (!of_busses[i].match || of_busses[i].match(np))
 424                         return &of_busses[i];
 425         BUG();
 426         return NULL;
 427 }
 428
 429 static int __init build_one_resource(struct device_node *parent,
 430                                      struct of_bus *bus,
 431                                      struct of_bus *pbus,
 432                                      u32 *addr,
 433                                      int na, int ns, int pna)
 434 {
 435         u32 *ranges;
 436         unsigned int rlen;
 437         int rone;
 438
 439         ranges = of_get_property(parent, "ranges", &rlen);
 440         if (ranges == NULL || rlen == 0) {
 441                 u32 result[OF_MAX_ADDR_CELLS];
 442                 int i;
 443
 444                 memset(result, 0, pna * 4);
 445                 for (i = 0; i < na; i++)
 446                         result[pna - 1 - i] =
 447                                 addr[na - 1 - i];
 448
 449                 memcpy(addr, result, pna * 4);
 450                 return 0;
 451         }
 452
 453         /* Now walk through the ranges */
 454         rlen /= 4;
 455         rone = na + pna + ns;
 456         for (; rlen >= rone; rlen -= rone, ranges += rone) {
 457                 if (!bus->map(addr, ranges, na, ns, pna))
 458                         return 0;
 459         }
 460
 461         return 1;
 462 }
 463
 464 static int of_resource_verbose;
 465
 466 static void __init build_device_resources(struct of_device *op,
 467                                           struct device *parent)
 468 {
 469         struct of_device *p_op;
 470         struct of_bus *bus;
 471         int na, ns;
 472         int index, num_reg;
 473         void *preg;
 474
 475         if (!parent)
 476                 return;
 477
 478         p_op = to_of_device(parent);
 479         bus = of_match_bus(p_op->node);
 480         bus->count_cells(op->node, &na, &ns);
 481
 482         preg = of_get_property(op->node, bus->addr_prop_name, &num_reg);
 483         if (!preg || num_reg == 0)
 484                 return;
 485
 486         /* Convert to num-cells.  */
 487         num_reg /= 4;
 488
 489         /* Conver to num-entries.  */
 490         num_reg /= na + ns;
 491
 492         for (index = 0; index < num_reg; index++) {
 493                 struct resource *r = &op->resource[index];
 494                 u32 addr[OF_MAX_ADDR_CELLS];
 495                 u32 *reg = (preg + (index * ((na + ns) * 4)));
 496                 struct device_node *dp = op->node;
 497                 struct device_node *pp = p_op->node;
 498                 struct of_bus *pbus;
 499                 u64 size, result = OF_BAD_ADDR;
 500                 unsigned long flags;
 501                 int dna, dns;
 502                 int pna, pns;
 503
 504                 size = of_read_addr(reg + na, ns);
 505                 flags = bus->get_flags(reg);
 506
 507                 memcpy(addr, reg, na * 4);
 508
 509                 /* If the immediate parent has no ranges property to apply,
 510                  * just use a 1<->1 mapping.
 511                  */
 512                 if (of_find_property(pp, "ranges", NULL) == NULL) {
 513                         result = of_read_addr(addr, na);
 514                         goto build_res;
 515                 }
 516
 517                 dna = na;
 518                 dns = ns;
 519
 520                 while (1) {
 521                         dp = pp;
 522                         pp = dp->parent;
 523                         if (!pp) {
 524                                 result = of_read_addr(addr, dna);
 525                                 break;
 526                         }
 527
 528                         pbus = of_match_bus(pp);
 529                         pbus->count_cells(dp, &pna, &pns);
 530
 531                         if (build_one_resource(dp, bus, pbus, addr,
 532                                                dna, dns, pna))
 533                                 break;
 534
 535                         dna = pna;
 536                         dns = pns;
 537                         bus = pbus;
 538                 }
 539
 540         build_res:
 541                 memset(r, 0, sizeof(*r));
 542
 543                 if (of_resource_verbose)
 544                         printk("%s reg[%d] -> %llx\n",
 545                                op->node->full_name, index,
 546                                result);
 547
 548                 if (result != OF_BAD_ADDR) {
 549                         r->start = result & 0xffffffff;
 550                         r->end = result + size - 1;
 551                         r->flags = flags | ((result >> 32ULL) & 0xffUL);
 552                 } else {
 553                         r->start = ~0UL;
 554                         r->end = ~0UL;
 555                 }
 556                 r->name = op->node->name;
 557         }
 558 }
 559
 560 static struct of_device * __init scan_one_device(struct device_node *dp,
 561                                                  struct device *parent)
 562 {
 563         struct of_device *op = kzalloc(sizeof(*op), GFP_KERNEL);
 564         struct linux_prom_irqs *intr;
 565         int len, i;
 566
 567         if (!op)
 568                 return NULL;
 569
 570         op->node = dp;
 571
 572         op->clock_freq = of_getintprop_default(dp, "clock-frequency",
 573                                                (25*1000*1000));
 574         op->portid = of_getintprop_default(dp, "upa-portid", -1);
 575         if (op->portid == -1)
 576                 op->portid = of_getintprop_default(dp, "portid", -1);
 577
 578         intr = of_get_property(dp, "intr", &len);
 579         if (intr) {
 580                 op->num_irqs = len / sizeof(struct linux_prom_irqs);
 581                 for (i = 0; i < op->num_irqs; i++)
 582                         op->irqs[i] = intr[i].pri;
 583         } else {
 584                 unsigned int *irq = of_get_property(dp, "interrupts", &len);
 585
 586                 if (irq) {
 587                         op->num_irqs = len / sizeof(unsigned int);
 588                         for (i = 0; i < op->num_irqs; i++)
 589                                 op->irqs[i] = irq[i];
 590                 } else {
 591                         op->num_irqs = 0;
 592                 }
 593         }
 594         if (sparc_cpu_model == sun4d) {
 595                 static int pil_to_sbus[] = {
 596                         0, 0, 1, 2, 0, 3, 0, 4, 0, 5, 0, 6, 0, 7, 0, 0,
 597                 };
 598                 struct device_node *io_unit, *sbi = dp->parent;
 599                 struct linux_prom_registers *regs;
 600                 int board, slot;
 601
 602                 while (sbi) {
 603                         if (!strcmp(sbi->name, "sbi"))
 604                                 break;
 605
 606                         sbi = sbi->parent;
 607                 }
 608                 if (!sbi)
 609                         goto build_resources;
 610
 611                 regs = of_get_property(dp, "reg", NULL);
 612                 if (!regs)
 613                         goto build_resources;
 614
 615                 slot = regs->which_io;
 616
 617                 /* If SBI's parent is not io-unit or the io-unit lacks
 618                  * a "board#" property, something is very wrong.
 619                  */
 620                 if (!sbi->parent || strcmp(sbi->parent->name, "io-unit")) {
 621                         printk("%s: Error, parent is not io-unit.\n",
 622                                sbi->full_name);
 623                         goto build_resources;
 624                 }
 625                 io_unit = sbi->parent;
 626                 board = of_getintprop_default(io_unit, "board#", -1);
 627                 if (board == -1) {
 628                         printk("%s: Error, lacks board# property.\n",
 629                                io_unit->full_name);
 630                         goto build_resources;
 631                 }
 632
 633                 for (i = 0; i < op->num_irqs; i++) {
 634                         int this_irq = op->irqs[i];
 635                         int sbusl = pil_to_sbus[this_irq];
 636
 637                         if (sbusl)
 638                                 this_irq = (((board + 1) << 5) +
 639                                             (sbusl << 2) +
 640                                             slot);
 641
 642                         op->irqs[i] = this_irq;
 643                 }
 644         }
 645
 646 build_resources:
 647         build_device_resources(op, parent);
 648
 649         op->dev.parent = parent;
 650         op->dev.bus = &of_bus_type;
 651         if (!parent)
 652                 strcpy(op->dev.bus_id, "root");
 653         else
 654                 sprintf(op->dev.bus_id, "%08x", dp->node);
 655
 656         if (of_device_register(op)) {
 657                 printk("%s: Could not register of device.\n",
 658                        dp->full_name);
 659                 kfree(op);
 660                 op = NULL;
 661         }
 662
 663         return op;
 664 }
 665
 666 static void __init scan_tree(struct device_node *dp, struct device *parent)
 667 {
 668         while (dp) {
 669                 struct of_device *op = scan_one_device(dp, parent);
 670
 671                 if (op)
 672                         scan_tree(dp->child, &op->dev);
 673
 674                 dp = dp->sibling;
 675         }
 676 }
 677
 678 static void __init scan_of_devices(void)
 679 {
 680         struct device_node *root = of_find_node_by_path("/");
 681         struct of_device *parent;
 682
 683         parent = scan_one_device(root, NULL);
 684         if (!parent)
 685                 return;
 686
 687         scan_tree(root->child, &parent->dev);
 688 }
 689
 690 static int __init of_bus_driver_init(void)
 691 {
 692         int err;
 693
 694         err = bus_register(&of_bus_type);
 695 #ifdef CONFIG_PCI
 696         if (!err)
 697                 err = bus_register(&ebus_bus_type);
 698 #endif
 699 #ifdef CONFIG_SBUS
 700         if (!err)
 701                 err = bus_register(&sbus_bus_type);
 702 #endif
 703
 704         if (!err)
 705                 scan_of_devices();
 706
 707         return err;
 708 }
 709
 710 postcore_initcall(of_bus_driver_init);
 711
 712 static int __init of_debug(char *str)
 713 {
 714         int val = 0;
 715
 716         get_option(&str, &val);
 717         if (val & 1)
 718                 of_resource_verbose = 1;
 719         return 1;
 720 }
 721
 722 __setup("of_debug=", of_debug);
 723
 724 int of_register_driver(struct of_platform_driver *drv, struct bus_type *bus)
 725 {
 726         /* initialize common driver fields */
 727         drv->driver.name = drv->name;
 728         drv->driver.bus = bus;
 729
 730         /* register with core */
 731         return driver_register(&drv->driver);
 732 }
 733
 734 void of_unregister_driver(struct of_platform_driver *drv)
 735 {
 736         driver_unregister(&drv->driver);
 737 }
 738
 739
 740 static ssize_t dev_show_devspec(struct device *dev, struct device_attribute *attr, char *buf)
 741 {
 742         struct of_device *ofdev;
 743
 744         ofdev = to_of_device(dev);
 745         return sprintf(buf, "%s", ofdev->node->full_name);
 746 }
 747
 748 static DEVICE_ATTR(devspec, S_IRUGO, dev_show_devspec, NULL);
 749
 750 /**
 751  * of_release_dev - free an of device structure when all users of it are finished.
 752  * @dev: device that's been disconnected
 753  *
 754  * Will be called only by the device core when all users of this of device are
 755  * done.
 756  */
 757 void of_release_dev(struct device *dev)
 758 {
 759         struct of_device *ofdev;
 760
 761         ofdev = to_of_device(dev);
 762
 763         kfree(ofdev);
 764 }
 765
 766 int of_device_register(struct of_device *ofdev)
 767 {
 768         int rc;
 769
 770         BUG_ON(ofdev->node == NULL);
 771
 772         rc = device_register(&ofdev->dev);
 773         if (rc)
 774                 return rc;
 775
 776         rc = device_create_file(&ofdev->dev, &dev_attr_devspec);
 777         if (rc)
 778                 device_unregister(&ofdev->dev);
 779
 780         return rc;
 781 }
 782
 783 void of_device_unregister(struct of_device *ofdev)
 784 {
 785         device_remove_file(&ofdev->dev, &dev_attr_devspec);
 786         device_unregister(&ofdev->dev);
 787 }
 788
 789 struct of_device* of_platform_device_create(struct device_node *np,
 790                                             const char *bus_id,
 791                                             struct device *parent,
 792                                             struct bus_type *bus)
 793 {
 794         struct of_device *dev;
 795
 796         dev = kmalloc(sizeof(*dev), GFP_KERNEL);
 797         if (!dev)
 798                 return NULL;
 799         memset(dev, 0, sizeof(*dev));
 800
 801         dev->dev.parent = parent;
 802         dev->dev.bus = bus;
 803         dev->dev.release = of_release_dev;
 804
 805         strlcpy(dev->dev.bus_id, bus_id, BUS_ID_SIZE);
 806
 807         if (of_device_register(dev) != 0) {
 808                 kfree(dev);
 809                 return NULL;
 810         }
 811
 812         return dev;
 813 }
 814
 815 EXPORT_SYMBOL(of_match_device);
 816 EXPORT_SYMBOL(of_register_driver);
 817 EXPORT_SYMBOL(of_unregister_driver);
 818 EXPORT_SYMBOL(of_device_register);
 819 EXPORT_SYMBOL(of_device_unregister);
 820 EXPORT_SYMBOL(of_dev_get);
 821 EXPORT_SYMBOL(of_dev_put);
 822 EXPORT_SYMBOL(of_platform_device_create);
 823 EXPORT_SYMBOL(of_release_dev);