drivers/of/platform.c

   1 /*
   2  *    Copyright (C) 2006 Benjamin Herrenschmidt, IBM Corp.
   3  *                       <benh@kernel.crashing.org>
   4  *    and                Arnd Bergmann, IBM Corp.
   5  *    Merged from powerpc/kernel/of_platform.c and
   6  *    sparc{,64}/kernel/of_device.c by Stephen Rothwell
   7  *
   8  *  This program is free software; you can redistribute it and/or
   9  *  modify it under the terms of the GNU General Public License
  10  *  as published by the Free Software Foundation; either version
  11  *  2 of the License, or (at your option) any later version.
  12  *
  13  */
  14 #include <linux/errno.h>
  15 #include <linux/module.h>
  16 #include <linux/device.h>
  17 #include <linux/dma-mapping.h>
  18 #include <linux/slab.h>
  19 #include <linux/of_address.h>
  20 #include <linux/of_device.h>
  21 #include <linux/of_irq.h>
  22 #include <linux/of_platform.h>
  23 #include <linux/platform_device.h>
  24
  25 static int of_dev_node_match(struct device *dev, void *data)
  26 {
  27         return dev->of_node == data;
  28 }
  29
  30 /**
  31  * of_find_device_by_node - Find the platform_device associated with a node
  32  * @np: Pointer to device tree node
  33  *
  34  * Returns platform_device pointer, or NULL if not found
  35  */
  36 struct platform_device *of_find_device_by_node(struct device_node *np)
  37 {
  38         struct device *dev;
  39
  40         dev = bus_find_device(&platform_bus_type, NULL, np, of_dev_node_match);
  41         return dev ? to_platform_device(dev) : NULL;
  42 }
  43 EXPORT_SYMBOL(of_find_device_by_node);
  44
  45 static int platform_driver_probe_shim(struct platform_device *pdev)
  46 {
  47         struct platform_driver *pdrv;
  48         struct of_platform_driver *ofpdrv;
  49         const struct of_device_id *match;
  50
  51         pdrv = container_of(pdev->dev.driver, struct platform_driver, driver);
  52         ofpdrv = container_of(pdrv, struct of_platform_driver, platform_driver);
  53
  54         /* There is an unlikely chance that an of_platform driver might match
  55          * on a non-OF platform device.  If so, then of_match_device() will
  56          * come up empty.  Return -EINVAL in this case so other drivers get
  57          * the chance to bind. */
  58         match = of_match_device(pdev->dev.driver->of_match_table, &pdev->dev);
  59         return match ? ofpdrv->probe(pdev, match) : -EINVAL;
  60 }
  61
  62 static void platform_driver_shutdown_shim(struct platform_device *pdev)
  63 {
  64         struct platform_driver *pdrv;
  65         struct of_platform_driver *ofpdrv;
  66
  67         pdrv = container_of(pdev->dev.driver, struct platform_driver, driver);
  68         ofpdrv = container_of(pdrv, struct of_platform_driver, platform_driver);
  69         ofpdrv->shutdown(pdev);
  70 }
  71
  72 /**
  73  * of_register_platform_driver
  74  */
  75 int of_register_platform_driver(struct of_platform_driver *drv)
  76 {
  77         /* setup of_platform_driver to platform_driver adaptors */
  78         drv->platform_driver.driver = drv->driver;
  79         if (drv->probe)
  80                 drv->platform_driver.probe = platform_driver_probe_shim;
  81         drv->platform_driver.remove = drv->remove;
  82         if (drv->shutdown)
  83                 drv->platform_driver.shutdown = platform_driver_shutdown_shim;
  84         drv->platform_driver.suspend = drv->suspend;
  85         drv->platform_driver.resume = drv->resume;
  86
  87         return platform_driver_register(&drv->platform_driver);
  88 }
  89 EXPORT_SYMBOL(of_register_platform_driver);
  90
  91 void of_unregister_platform_driver(struct of_platform_driver *drv)
  92 {
  93         platform_driver_unregister(&drv->platform_driver);
  94 }
  95 EXPORT_SYMBOL(of_unregister_platform_driver);
  96
  97 #if defined(CONFIG_PPC_DCR)
  98 #include <asm/dcr.h>
  99 #endif
 100
 101 extern struct device_attribute of_platform_device_attrs[];
 102
 103 static int of_platform_bus_match(struct device *dev, struct device_driver *drv)
 104 {
 105         const struct of_device_id *matches = drv->of_match_table;
 106
 107         if (!matches)
 108                 return 0;
 109
 110         return of_match_device(matches, dev) != NULL;
 111 }
 112
 113 static int of_platform_device_probe(struct device *dev)
 114 {
 115         int error = -ENODEV;
 116         struct of_platform_driver *drv;
 117         struct platform_device *of_dev;
 118         const struct of_device_id *match;
 119
 120         drv = to_of_platform_driver(dev->driver);
 121         of_dev = to_platform_device(dev);
 122
 123         if (!drv->probe)
 124                 return error;
 125
 126         of_dev_get(of_dev);
 127
 128         match = of_match_device(drv->driver.of_match_table, dev);
 129         if (match)
 130                 error = drv->probe(of_dev, match);
 131         if (error)
 132                 of_dev_put(of_dev);
 133
 134         return error;
 135 }
 136
 137 static int of_platform_device_remove(struct device *dev)
 138 {
 139         struct platform_device *of_dev = to_platform_device(dev);
 140         struct of_platform_driver *drv = to_of_platform_driver(dev->driver);
 141
 142         if (dev->driver && drv->remove)
 143                 drv->remove(of_dev);
 144         return 0;
 145 }
 146
 147 static void of_platform_device_shutdown(struct device *dev)
 148 {
 149         struct platform_device *of_dev = to_platform_device(dev);
 150         struct of_platform_driver *drv = to_of_platform_driver(dev->driver);
 151
 152         if (dev->driver && drv->shutdown)
 153                 drv->shutdown(of_dev);
 154 }
 155
 156 #ifdef CONFIG_PM_SLEEP
 157
 158 static int of_platform_legacy_suspend(struct device *dev, pm_message_t mesg)
 159 {
 160         struct platform_device *of_dev = to_platform_device(dev);
 161         struct of_platform_driver *drv = to_of_platform_driver(dev->driver);
 162         int ret = 0;
 163
 164         if (dev->driver && drv->suspend)
 165                 ret = drv->suspend(of_dev, mesg);
 166         return ret;
 167 }
 168
 169 static int of_platform_legacy_resume(struct device *dev)
 170 {
 171         struct platform_device *of_dev = to_platform_device(dev);
 172         struct of_platform_driver *drv = to_of_platform_driver(dev->driver);
 173         int ret = 0;
 174
 175         if (dev->driver && drv->resume)
 176                 ret = drv->resume(of_dev);
 177         return ret;
 178 }
 179
 180 static int of_platform_pm_prepare(struct device *dev)
 181 {
 182         struct device_driver *drv = dev->driver;
 183         int ret = 0;
 184
 185         if (drv && drv->pm && drv->pm->prepare)
 186                 ret = drv->pm->prepare(dev);
 187
 188         return ret;
 189 }
 190
 191 static void of_platform_pm_complete(struct device *dev)
 192 {
 193         struct device_driver *drv = dev->driver;
 194
 195         if (drv && drv->pm && drv->pm->complete)
 196                 drv->pm->complete(dev);
 197 }
 198
 199 #ifdef CONFIG_SUSPEND
 200
 201 static int of_platform_pm_suspend(struct device *dev)
 202 {
 203         struct device_driver *drv = dev->driver;
 204         int ret = 0;
 205
 206         if (!drv)
 207                 return 0;
 208
 209         if (drv->pm) {
 210                 if (drv->pm->suspend)
 211                         ret = drv->pm->suspend(dev);
 212         } else {
 213                 ret = of_platform_legacy_suspend(dev, PMSG_SUSPEND);
 214         }
 215
 216         return ret;
 217 }
 218
 219 static int of_platform_pm_suspend_noirq(struct device *dev)
 220 {
 221         struct device_driver *drv = dev->driver;
 222         int ret = 0;
 223
 224         if (!drv)
 225                 return 0;
 226
 227         if (drv->pm) {
 228                 if (drv->pm->suspend_noirq)
 229                         ret = drv->pm->suspend_noirq(dev);
 230         }
 231
 232         return ret;
 233 }
 234
 235 static int of_platform_pm_resume(struct device *dev)
 236 {
 237         struct device_driver *drv = dev->driver;
 238         int ret = 0;
 239
 240         if (!drv)
 241                 return 0;
 242
 243         if (drv->pm) {
 244                 if (drv->pm->resume)
 245                         ret = drv->pm->resume(dev);
 246         } else {
 247                 ret = of_platform_legacy_resume(dev);
 248         }
 249
 250         return ret;
 251 }
 252
 253 static int of_platform_pm_resume_noirq(struct device *dev)
 254 {
 255         struct device_driver *drv = dev->driver;
 256         int ret = 0;
 257
 258         if (!drv)
 259                 return 0;
 260
 261         if (drv->pm) {
 262                 if (drv->pm->resume_noirq)
 263                         ret = drv->pm->resume_noirq(dev);
 264         }
 265
 266         return ret;
 267 }
 268
 269 #else /* !CONFIG_SUSPEND */
 270
 271 #define of_platform_pm_suspend          NULL
 272 #define of_platform_pm_resume           NULL
 273 #define of_platform_pm_suspend_noirq    NULL
 274 #define of_platform_pm_resume_noirq     NULL
 275
 276 #endif /* !CONFIG_SUSPEND */
 277
 278 #ifdef CONFIG_HIBERNATION
 279
 280 static int of_platform_pm_freeze(struct device *dev)
 281 {
 282         struct device_driver *drv = dev->driver;
 283         int ret = 0;
 284
 285         if (!drv)
 286                 return 0;
 287
 288         if (drv->pm) {
 289                 if (drv->pm->freeze)
 290                         ret = drv->pm->freeze(dev);
 291         } else {
 292                 ret = of_platform_legacy_suspend(dev, PMSG_FREEZE);
 293         }
 294
 295         return ret;
 296 }
 297
 298 static int of_platform_pm_freeze_noirq(struct device *dev)
 299 {
 300         struct device_driver *drv = dev->driver;
 301         int ret = 0;
 302
 303         if (!drv)
 304                 return 0;
 305
 306         if (drv->pm) {
 307                 if (drv->pm->freeze_noirq)
 308                         ret = drv->pm->freeze_noirq(dev);
 309         }
 310
 311         return ret;
 312 }
 313
 314 static int of_platform_pm_thaw(struct device *dev)
 315 {
 316         struct device_driver *drv = dev->driver;
 317         int ret = 0;
 318
 319         if (!drv)
 320                 return 0;
 321
 322         if (drv->pm) {
 323                 if (drv->pm->thaw)
 324                         ret = drv->pm->thaw(dev);
 325         } else {
 326                 ret = of_platform_legacy_resume(dev);
 327         }
 328
 329         return ret;
 330 }
 331
 332 static int of_platform_pm_thaw_noirq(struct device *dev)
 333 {
 334         struct device_driver *drv = dev->driver;
 335         int ret = 0;
 336
 337         if (!drv)
 338                 return 0;
 339
 340         if (drv->pm) {
 341                 if (drv->pm->thaw_noirq)
 342                         ret = drv->pm->thaw_noirq(dev);
 343         }
 344
 345         return ret;
 346 }
 347
 348 static int of_platform_pm_poweroff(struct device *dev)
 349 {
 350         struct device_driver *drv = dev->driver;
 351         int ret = 0;
 352
 353         if (!drv)
 354                 return 0;
 355
 356         if (drv->pm) {
 357                 if (drv->pm->poweroff)
 358                         ret = drv->pm->poweroff(dev);
 359         } else {
 360                 ret = of_platform_legacy_suspend(dev, PMSG_HIBERNATE);
 361         }
 362
 363         return ret;
 364 }
 365
 366 static int of_platform_pm_poweroff_noirq(struct device *dev)
 367 {
 368         struct device_driver *drv = dev->driver;
 369         int ret = 0;
 370
 371         if (!drv)
 372                 return 0;
 373
 374         if (drv->pm) {
 375                 if (drv->pm->poweroff_noirq)
 376                         ret = drv->pm->poweroff_noirq(dev);
 377         }
 378
 379         return ret;
 380 }
 381
 382 static int of_platform_pm_restore(struct device *dev)
 383 {
 384         struct device_driver *drv = dev->driver;
 385         int ret = 0;
 386
 387         if (!drv)
 388                 return 0;
 389
 390         if (drv->pm) {
 391                 if (drv->pm->restore)
 392                         ret = drv->pm->restore(dev);
 393         } else {
 394                 ret = of_platform_legacy_resume(dev);
 395         }
 396
 397         return ret;
 398 }
 399
 400 static int of_platform_pm_restore_noirq(struct device *dev)
 401 {
 402         struct device_driver *drv = dev->driver;
 403         int ret = 0;
 404
 405         if (!drv)
 406                 return 0;
 407
 408         if (drv->pm) {
 409                 if (drv->pm->restore_noirq)
 410                         ret = drv->pm->restore_noirq(dev);
 411         }
 412
 413         return ret;
 414 }
 415
 416 #else /* !CONFIG_HIBERNATION */
 417
 418 #define of_platform_pm_freeze           NULL
 419 #define of_platform_pm_thaw             NULL
 420 #define of_platform_pm_poweroff         NULL
 421 #define of_platform_pm_restore          NULL
 422 #define of_platform_pm_freeze_noirq     NULL
 423 #define of_platform_pm_thaw_noirq               NULL
 424 #define of_platform_pm_poweroff_noirq   NULL
 425 #define of_platform_pm_restore_noirq    NULL
 426
 427 #endif /* !CONFIG_HIBERNATION */
 428
 429 static struct dev_pm_ops of_platform_dev_pm_ops = {
 430         .prepare = of_platform_pm_prepare,
 431         .complete = of_platform_pm_complete,
 432         .suspend = of_platform_pm_suspend,
 433         .resume = of_platform_pm_resume,
 434         .freeze = of_platform_pm_freeze,
 435         .thaw = of_platform_pm_thaw,
 436         .poweroff = of_platform_pm_poweroff,
 437         .restore = of_platform_pm_restore,
 438         .suspend_noirq = of_platform_pm_suspend_noirq,
 439         .resume_noirq = of_platform_pm_resume_noirq,
 440         .freeze_noirq = of_platform_pm_freeze_noirq,
 441         .thaw_noirq = of_platform_pm_thaw_noirq,
 442         .poweroff_noirq = of_platform_pm_poweroff_noirq,
 443         .restore_noirq = of_platform_pm_restore_noirq,
 444 };
 445
 446 #define OF_PLATFORM_PM_OPS_PTR  (&of_platform_dev_pm_ops)
 447
 448 #else /* !CONFIG_PM_SLEEP */
 449
 450 #define OF_PLATFORM_PM_OPS_PTR  NULL
 451
 452 #endif /* !CONFIG_PM_SLEEP */
 453
 454 int of_bus_type_init(struct bus_type *bus, const char *name)
 455 {
 456         bus->name = name;
 457         bus->match = of_platform_bus_match;
 458         bus->probe = of_platform_device_probe;
 459         bus->remove = of_platform_device_remove;
 460         bus->shutdown = of_platform_device_shutdown;
 461         bus->dev_attrs = of_platform_device_attrs;
 462         bus->pm = OF_PLATFORM_PM_OPS_PTR;
 463         return bus_register(bus);
 464 }
 465
 466 int of_register_driver(struct of_platform_driver *drv, struct bus_type *bus)
 467 {
 468         /*
 469          * Temporary: of_platform_bus used to be distinct from the platform
 470          * bus.  It isn't anymore, and so drivers on the platform bus need
 471          * to be registered in a special way.
 472          *
 473          * After all of_platform_bus_type drivers are converted to
 474          * platform_drivers, this exception can be removed.
 475          */
 476         if (bus == &platform_bus_type)
 477                 return of_register_platform_driver(drv);
 478
 479         /* register with core */
 480         drv->driver.bus = bus;
 481         return driver_register(&drv->driver);
 482 }
 483 EXPORT_SYMBOL(of_register_driver);
 484
 485 void of_unregister_driver(struct of_platform_driver *drv)
 486 {
 487         if (drv->driver.bus == &platform_bus_type)
 488                 of_unregister_platform_driver(drv);
 489         else
 490                 driver_unregister(&drv->driver);
 491 }
 492 EXPORT_SYMBOL(of_unregister_driver);
 493
 494 #if !defined(CONFIG_SPARC)
 495 /*
 496  * The following routines scan a subtree and registers a device for
 497  * each applicable node.
 498  *
 499  * Note: sparc doesn't use these routines because it has a different
 500  * mechanism for creating devices from device tree nodes.
 501  */
 502
 503 /**
 504  * of_device_make_bus_id - Use the device node data to assign a unique name
 505  * @dev: pointer to device structure that is linked to a device tree node
 506  *
 507  * This routine will first try using either the dcr-reg or the reg property
 508  * value to derive a unique name.  As a last resort it will use the node
 509  * name followed by a unique number.
 510  */
 511 static void of_device_make_bus_id(struct device *dev)
 512 {
 513         static atomic_t bus_no_reg_magic;
 514         struct device_node *node = dev->of_node;
 515         const u32 *reg;
 516         u64 addr;
 517         int magic;
 518
 519 #ifdef CONFIG_PPC_DCR
 520         /*
 521          * If it's a DCR based device, use 'd' for native DCRs
 522          * and 'D' for MMIO DCRs.
 523          */
 524         reg = of_get_property(node, "dcr-reg", NULL);
 525         if (reg) {
 526 #ifdef CONFIG_PPC_DCR_NATIVE
 527                 dev_set_name(dev, "d%x.%s", *reg, node->name);
 528 #else /* CONFIG_PPC_DCR_NATIVE */
 529                 u64 addr = of_translate_dcr_address(node, *reg, NULL);
 530                 if (addr != OF_BAD_ADDR) {
 531                         dev_set_name(dev, "D%llx.%s",
 532                                      (unsigned long long)addr, node->name);
 533                         return;
 534                 }
 535 #endif /* !CONFIG_PPC_DCR_NATIVE */
 536         }
 537 #endif /* CONFIG_PPC_DCR */
 538
 539         /*
 540          * For MMIO, get the physical address
 541          */
 542         reg = of_get_property(node, "reg", NULL);
 543         if (reg) {
 544                 addr = of_translate_address(node, reg);
 545                 if (addr != OF_BAD_ADDR) {
 546                         dev_set_name(dev, "%llx.%s",
 547                                      (unsigned long long)addr, node->name);
 548                         return;
 549                 }
 550         }
 551
 552         /*
 553          * No BusID, use the node name and add a globally incremented
 554          * counter (and pray...)
 555          */
 556         magic = atomic_add_return(1, &bus_no_reg_magic);
 557         dev_set_name(dev, "%s.%d", node->name, magic - 1);
 558 }
 559
 560 /**
 561  * of_device_alloc - Allocate and initialize an of_device
 562  * @np: device node to assign to device
 563  * @bus_id: Name to assign to the device.  May be null to use default name.
 564  * @parent: Parent device.
 565  */
 566 struct platform_device *of_device_alloc(struct device_node *np,
 567                                   const char *bus_id,
 568                                   struct device *parent)
 569 {
 570         struct platform_device *dev;
 571         int rc, i, num_reg = 0, num_irq = 0;
 572         struct resource *res, temp_res;
 573
 574         /* First count how many resources are needed */
 575         while (of_address_to_resource(np, num_reg, &temp_res) == 0)
 576                 num_reg++;
 577         while (of_irq_to_resource(np, num_irq, &temp_res) != NO_IRQ)
 578                 num_irq++;
 579
 580         /* Allocate memory for both the struct device and the resource table */
 581         dev = kzalloc(sizeof(*dev) + (sizeof(*res) * (num_reg + num_irq)),
 582                       GFP_KERNEL);
 583         if (!dev)
 584                 return NULL;
 585         res = (struct resource *) &dev[1];
 586
 587         /* Populate the resource table */
 588         if (num_irq || num_reg) {
 589                 dev->num_resources = num_reg + num_irq;
 590                 dev->resource = res;
 591                 for (i = 0; i < num_reg; i++, res++) {
 592                         rc = of_address_to_resource(np, i, res);
 593                         WARN_ON(rc);
 594                 }
 595                 for (i = 0; i < num_irq; i++, res++) {
 596                         rc = of_irq_to_resource(np, i, res);
 597                         WARN_ON(rc == NO_IRQ);
 598                 }
 599         }
 600
 601         dev->dev.of_node = of_node_get(np);
 602 #if defined(CONFIG_PPC) || defined(CONFIG_MICROBLAZE)
 603         dev->dev.dma_mask = &dev->archdata.dma_mask;
 604 #endif
 605         dev->dev.parent = parent;
 606         dev->dev.release = of_release_dev;
 607
 608         if (bus_id)
 609                 dev_set_name(&dev->dev, "%s", bus_id);
 610         else
 611                 of_device_make_bus_id(&dev->dev);
 612
 613         return dev;
 614 }
 615 EXPORT_SYMBOL(of_device_alloc);
 616
 617 /**
 618  * of_platform_device_create - Alloc, initialize and register an of_device
 619  * @np: pointer to node to create device for
 620  * @bus_id: name to assign device
 621  * @parent: Linux device model parent device.
 622  */
 623 struct platform_device *of_platform_device_create(struct device_node *np,
 624                                             const char *bus_id,
 625                                             struct device *parent)
 626 {
 627         struct platform_device *dev;
 628
 629         dev = of_device_alloc(np, bus_id, parent);
 630         if (!dev)
 631                 return NULL;
 632
 633 #if defined(CONFIG_PPC) || defined(CONFIG_MICROBLAZE)
 634         dev->archdata.dma_mask = 0xffffffffUL;
 635 #endif
 636         dev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
 637         dev->dev.bus = &platform_bus_type;
 638
 639         /* We do not fill the DMA ops for platform devices by default.
 640          * This is currently the responsibility of the platform code
 641          * to do such, possibly using a device notifier
 642          */
 643
 644         if (of_device_register(dev) != 0) {
 645                 of_device_free(dev);
 646                 return NULL;
 647         }
 648
 649         return dev;
 650 }
 651 EXPORT_SYMBOL(of_platform_device_create);
 652
 653 /**
 654  * of_platform_bus_create - Create an OF device for a bus node and all its
 655  * children. Optionally recursively instantiate matching busses.
 656  * @bus: device node of the bus to instantiate
 657  * @matches: match table, NULL to use the default, OF_NO_DEEP_PROBE to
 658  * disallow recursive creation of child busses
 659  */
 660 static int of_platform_bus_create(const struct device_node *bus,
 661                                   const struct of_device_id *matches,
 662                                   struct device *parent)
 663 {
 664         struct device_node *child;
 665         struct platform_device *dev;
 666         int rc = 0;
 667
 668         for_each_child_of_node(bus, child) {
 669                 pr_debug("   create child: %s\n", child->full_name);
 670                 dev = of_platform_device_create(child, NULL, parent);
 671                 if (dev == NULL)
 672                         rc = -ENOMEM;
 673                 else if (!of_match_node(matches, child))
 674                         continue;
 675                 if (rc == 0) {
 676                         pr_debug("   and sub busses\n");
 677                         rc = of_platform_bus_create(child, matches, &dev->dev);
 678                 }
 679                 if (rc) {
 680                         of_node_put(child);
 681                         break;
 682                 }
 683         }
 684         return rc;
 685 }
 686
 687 /**
 688  * of_platform_bus_probe - Probe the device-tree for platform busses
 689  * @root: parent of the first level to probe or NULL for the root of the tree
 690  * @matches: match table, NULL to use the default
 691  * @parent: parent to hook devices from, NULL for toplevel
 692  *
 693  * Note that children of the provided root are not instantiated as devices
 694  * unless the specified root itself matches the bus list and is not NULL.
 695  */
 696 int of_platform_bus_probe(struct device_node *root,
 697                           const struct of_device_id *matches,
 698                           struct device *parent)
 699 {
 700         struct device_node *child;
 701         struct platform_device *dev;
 702         int rc = 0;
 703
 704         if (matches == NULL)
 705                 matches = of_default_bus_ids;
 706         if (matches == OF_NO_DEEP_PROBE)
 707                 return -EINVAL;
 708         if (root == NULL)
 709                 root = of_find_node_by_path("/");
 710         else
 711                 of_node_get(root);
 712         if (root == NULL)
 713                 return -EINVAL;
 714
 715         pr_debug("of_platform_bus_probe()\n");
 716         pr_debug(" starting at: %s\n", root->full_name);
 717
 718         /* Do a self check of bus type, if there's a match, create
 719          * children
 720          */
 721         if (of_match_node(matches, root)) {
 722                 pr_debug(" root match, create all sub devices\n");
 723                 dev = of_platform_device_create(root, NULL, parent);
 724                 if (dev == NULL) {
 725                         rc = -ENOMEM;
 726                         goto bail;
 727                 }
 728                 pr_debug(" create all sub busses\n");
 729                 rc = of_platform_bus_create(root, matches, &dev->dev);
 730                 goto bail;
 731         }
 732         for_each_child_of_node(root, child) {
 733                 if (!of_match_node(matches, child))
 734                         continue;
 735
 736                 pr_debug("  match: %s\n", child->full_name);
 737                 dev = of_platform_device_create(child, NULL, parent);
 738                 if (dev == NULL)
 739                         rc = -ENOMEM;
 740                 else
 741                         rc = of_platform_bus_create(child, matches, &dev->dev);
 742                 if (rc) {
 743                         of_node_put(child);
 744                         break;
 745                 }
 746         }
 747  bail:
 748         of_node_put(root);
 749         return rc;
 750 }
 751 EXPORT_SYMBOL(of_platform_bus_probe);
 752 #endif /* !CONFIG_SPARC */