arch/powerpc/kernel/ibmebus.c

   1 /*
   2  * IBM PowerPC IBM eBus Infrastructure Support.
   3  *
   4  * Copyright (c) 2005 IBM Corporation
   5  *  Joachim Fenkes <fenkes@de.ibm.com>
   6  *  Heiko J Schick <schickhj@de.ibm.com>
   7  *
   8  * All rights reserved.
   9  *
  10  * This source code is distributed under a dual license of GPL v2.0 and OpenIB
  11  * BSD.
  12  *
  13  * OpenIB BSD License
  14  *
  15  * Redistribution and use in source and binary forms, with or without
  16  * modification, are permitted provided that the following conditions are met:
  17  *
  18  * Redistributions of source code must retain the above copyright notice, this
  19  * list of conditions and the following disclaimer.
  20  *
  21  * Redistributions in binary form must reproduce the above copyright notice,
  22  * this list of conditions and the following disclaimer in the documentation
  23  * and/or other materials
  24  * provided with the distribution.
  25  *
  26  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  27  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  29  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  30  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  33  * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
  34  * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  36  * POSSIBILITY OF SUCH DAMAGE.
  37  */
  38
  39 #include <linux/init.h>
  40 #include <linux/console.h>
  41 #include <linux/kobject.h>
  42 #include <linux/dma-mapping.h>
  43 #include <linux/interrupt.h>
  44 #include <linux/of.h>
  45 #include <linux/slab.h>
  46 #include <linux/of_platform.h>
  47 #include <asm/ibmebus.h>
  48 #include <asm/abs_addr.h>
  49
  50 static struct device ibmebus_bus_device = { /* fake "parent" device */
  51         .init_name = "ibmebus",
  52 };
  53
  54 struct bus_type ibmebus_bus_type;
  55
  56 /* These devices will automatically be added to the bus during init */
  57 static struct of_device_id __initdata ibmebus_matches[] = {
  58         { .compatible = "IBM,lhca" },
  59         { .compatible = "IBM,lhea" },
  60         {},
  61 };
  62
  63 static void *ibmebus_alloc_coherent(struct device *dev,
  64                                     size_t size,
  65                                     dma_addr_t *dma_handle,
  66                                     gfp_t flag)
  67 {
  68         void *mem;
  69
  70         mem = kmalloc(size, flag);
  71         *dma_handle = (dma_addr_t)mem;
  72
  73         return mem;
  74 }
  75
  76 static void ibmebus_free_coherent(struct device *dev,
  77                                   size_t size, void *vaddr,
  78                                   dma_addr_t dma_handle)
  79 {
  80         kfree(vaddr);
  81 }
  82
  83 static dma_addr_t ibmebus_map_page(struct device *dev,
  84                                    struct page *page,
  85                                    unsigned long offset,
  86                                    size_t size,
  87                                    enum dma_data_direction direction,
  88                                    struct dma_attrs *attrs)
  89 {
  90         return (dma_addr_t)(page_address(page) + offset);
  91 }
  92
  93 static void ibmebus_unmap_page(struct device *dev,
  94                                dma_addr_t dma_addr,
  95                                size_t size,
  96                                enum dma_data_direction direction,
  97                                struct dma_attrs *attrs)
  98 {
  99         return;
 100 }
 101
 102 static int ibmebus_map_sg(struct device *dev,
 103                           struct scatterlist *sgl,
 104                           int nents, enum dma_data_direction direction,
 105                           struct dma_attrs *attrs)
 106 {
 107         struct scatterlist *sg;
 108         int i;
 109
 110         for_each_sg(sgl, sg, nents, i) {
 111                 sg->dma_address = (dma_addr_t) sg_virt(sg);
 112                 sg->dma_length = sg->length;
 113         }
 114
 115         return nents;
 116 }
 117
 118 static void ibmebus_unmap_sg(struct device *dev,
 119                              struct scatterlist *sg,
 120                              int nents, enum dma_data_direction direction,
 121                              struct dma_attrs *attrs)
 122 {
 123         return;
 124 }
 125
 126 static int ibmebus_dma_supported(struct device *dev, u64 mask)
 127 {
 128         return 1;
 129 }
 130
 131 static struct dma_map_ops ibmebus_dma_ops = {
 132         .alloc_coherent = ibmebus_alloc_coherent,
 133         .free_coherent  = ibmebus_free_coherent,
 134         .map_sg         = ibmebus_map_sg,
 135         .unmap_sg       = ibmebus_unmap_sg,
 136         .dma_supported  = ibmebus_dma_supported,
 137         .map_page       = ibmebus_map_page,
 138         .unmap_page     = ibmebus_unmap_page,
 139 };
 140
 141 static int ibmebus_match_path(struct device *dev, void *data)
 142 {
 143         struct device_node *dn = to_platform_device(dev)->dev.of_node;
 144         return (dn->full_name &&
 145                 (strcasecmp((char *)data, dn->full_name) == 0));
 146 }
 147
 148 static int ibmebus_match_node(struct device *dev, void *data)
 149 {
 150         return to_platform_device(dev)->dev.of_node == data;
 151 }
 152
 153 static int ibmebus_create_device(struct device_node *dn)
 154 {
 155         struct platform_device *dev;
 156         int ret;
 157
 158         dev = of_device_alloc(dn, NULL, &ibmebus_bus_device);
 159         if (!dev)
 160                 return -ENOMEM;
 161
 162         dev->dev.bus = &ibmebus_bus_type;
 163         dev->dev.archdata.dma_ops = &ibmebus_dma_ops;
 164
 165         ret = of_device_add(dev);
 166         if (ret)
 167                 platform_device_put(dev);
 168         return ret;
 169 }
 170
 171 static int ibmebus_create_devices(const struct of_device_id *matches)
 172 {
 173         struct device_node *root, *child;
 174         int ret = 0;
 175
 176         root = of_find_node_by_path("/");
 177
 178         for_each_child_of_node(root, child) {
 179                 if (!of_match_node(matches, child))
 180                         continue;
 181
 182                 if (bus_find_device(&ibmebus_bus_type, NULL, child,
 183                                     ibmebus_match_node))
 184                         continue;
 185
 186                 ret = ibmebus_create_device(child);
 187                 if (ret) {
 188                         printk(KERN_ERR "%s: failed to create device (%i)",
 189                                __func__, ret);
 190                         of_node_put(child);
 191                         break;
 192                 }
 193         }
 194
 195         of_node_put(root);
 196         return ret;
 197 }
 198
 199 int ibmebus_register_driver(struct of_platform_driver *drv)
 200 {
 201         /* If the driver uses devices that ibmebus doesn't know, add them */
 202         ibmebus_create_devices(drv->driver.of_match_table);
 203
 204         drv->driver.bus = &ibmebus_bus_type;
 205         return driver_register(&drv->driver);
 206 }
 207 EXPORT_SYMBOL(ibmebus_register_driver);
 208
 209 void ibmebus_unregister_driver(struct of_platform_driver *drv)
 210 {
 211         driver_unregister(&drv->driver);
 212 }
 213 EXPORT_SYMBOL(ibmebus_unregister_driver);
 214
 215 int ibmebus_request_irq(u32 ist, irq_handler_t handler,
 216                         unsigned long irq_flags, const char *devname,
 217                         void *dev_id)
 218 {
 219         unsigned int irq = irq_create_mapping(NULL, ist);
 220
 221         if (irq == NO_IRQ)
 222                 return -EINVAL;
 223
 224         return request_irq(irq, handler, irq_flags, devname, dev_id);
 225 }
 226 EXPORT_SYMBOL(ibmebus_request_irq);
 227
 228 void ibmebus_free_irq(u32 ist, void *dev_id)
 229 {
 230         unsigned int irq = irq_find_mapping(NULL, ist);
 231
 232         free_irq(irq, dev_id);
 233         irq_dispose_mapping(irq);
 234 }
 235 EXPORT_SYMBOL(ibmebus_free_irq);
 236
 237 static char *ibmebus_chomp(const char *in, size_t count)
 238 {
 239         char *out = kmalloc(count + 1, GFP_KERNEL);
 240
 241         if (!out)
 242                 return NULL;
 243
 244         memcpy(out, in, count);
 245         out[count] = '\0';
 246         if (out[count - 1] == '\n')
 247                 out[count - 1] = '\0';
 248
 249         return out;
 250 }
 251
 252 static ssize_t ibmebus_store_probe(struct bus_type *bus,
 253                                    const char *buf, size_t count)
 254 {
 255         struct device_node *dn = NULL;
 256         char *path;
 257         ssize_t rc = 0;
 258
 259         path = ibmebus_chomp(buf, count);
 260         if (!path)
 261                 return -ENOMEM;
 262
 263         if (bus_find_device(&ibmebus_bus_type, NULL, path,
 264                             ibmebus_match_path)) {
 265                 printk(KERN_WARNING "%s: %s has already been probed\n",
 266                        __func__, path);
 267                 rc = -EEXIST;
 268                 goto out;
 269         }
 270
 271         if ((dn = of_find_node_by_path(path))) {
 272                 rc = ibmebus_create_device(dn);
 273                 of_node_put(dn);
 274         } else {
 275                 printk(KERN_WARNING "%s: no such device node: %s\n",
 276                        __func__, path);
 277                 rc = -ENODEV;
 278         }
 279
 280 out:
 281         kfree(path);
 282         if (rc)
 283                 return rc;
 284         return count;
 285 }
 286
 287 static ssize_t ibmebus_store_remove(struct bus_type *bus,
 288                                     const char *buf, size_t count)
 289 {
 290         struct device *dev;
 291         char *path;
 292
 293         path = ibmebus_chomp(buf, count);
 294         if (!path)
 295                 return -ENOMEM;
 296
 297         if ((dev = bus_find_device(&ibmebus_bus_type, NULL, path,
 298                                    ibmebus_match_path))) {
 299                 of_device_unregister(to_platform_device(dev));
 300
 301                 kfree(path);
 302                 return count;
 303         } else {
 304                 printk(KERN_WARNING "%s: %s not on the bus\n",
 305                        __func__, path);
 306
 307                 kfree(path);
 308                 return -ENODEV;
 309         }
 310 }
 311
 312
 313 static struct bus_attribute ibmebus_bus_attrs[] = {
 314         __ATTR(probe, S_IWUSR, NULL, ibmebus_store_probe),
 315         __ATTR(remove, S_IWUSR, NULL, ibmebus_store_remove),
 316         __ATTR_NULL
 317 };
 318
 319 static int ibmebus_bus_bus_match(struct device *dev, struct device_driver *drv)
 320 {
 321         const struct of_device_id *matches = drv->of_match_table;
 322
 323         if (!matches)
 324                 return 0;
 325
 326         return of_match_device(matches, dev) != NULL;
 327 }
 328
 329 static int ibmebus_bus_device_probe(struct device *dev)
 330 {
 331         int error = -ENODEV;
 332         struct of_platform_driver *drv;
 333         struct platform_device *of_dev;
 334         const struct of_device_id *match;
 335
 336         drv = to_of_platform_driver(dev->driver);
 337         of_dev = to_platform_device(dev);
 338
 339         if (!drv->probe)
 340                 return error;
 341
 342         of_dev_get(of_dev);
 343
 344         match = of_match_device(drv->driver.of_match_table, dev);
 345         if (match)
 346                 error = drv->probe(of_dev, match);
 347         if (error)
 348                 of_dev_put(of_dev);
 349
 350         return error;
 351 }
 352
 353 static int ibmebus_bus_device_remove(struct device *dev)
 354 {
 355         struct platform_device *of_dev = to_platform_device(dev);
 356         struct of_platform_driver *drv = to_of_platform_driver(dev->driver);
 357
 358         if (dev->driver && drv->remove)
 359                 drv->remove(of_dev);
 360         return 0;
 361 }
 362
 363 static void ibmebus_bus_device_shutdown(struct device *dev)
 364 {
 365         struct platform_device *of_dev = to_platform_device(dev);
 366         struct of_platform_driver *drv = to_of_platform_driver(dev->driver);
 367
 368         if (dev->driver && drv->shutdown)
 369                 drv->shutdown(of_dev);
 370 }
 371
 372 /*
 373  * ibmebus_bus_device_attrs
 374  */
 375 static ssize_t devspec_show(struct device *dev,
 376                                 struct device_attribute *attr, char *buf)
 377 {
 378         struct platform_device *ofdev;
 379
 380         ofdev = to_platform_device(dev);
 381         return sprintf(buf, "%s\n", ofdev->dev.of_node->full_name);
 382 }
 383
 384 static ssize_t name_show(struct device *dev,
 385                                 struct device_attribute *attr, char *buf)
 386 {
 387         struct platform_device *ofdev;
 388
 389         ofdev = to_platform_device(dev);
 390         return sprintf(buf, "%s\n", ofdev->dev.of_node->name);
 391 }
 392
 393 static ssize_t modalias_show(struct device *dev,
 394                                 struct device_attribute *attr, char *buf)
 395 {
 396         ssize_t len = of_device_get_modalias(dev, buf, PAGE_SIZE - 2);
 397         buf[len] = '\n';
 398         buf[len+1] = 0;
 399         return len+1;
 400 }
 401
 402 struct device_attribute ibmebus_bus_device_attrs[] = {
 403         __ATTR_RO(devspec),
 404         __ATTR_RO(name),
 405         __ATTR_RO(modalias),
 406         __ATTR_NULL
 407 };
 408
 409 #ifdef CONFIG_PM_SLEEP
 410 static int ibmebus_bus_legacy_suspend(struct device *dev, pm_message_t mesg)
 411 {
 412         struct platform_device *of_dev = to_platform_device(dev);
 413         struct of_platform_driver *drv = to_of_platform_driver(dev->driver);
 414         int ret = 0;
 415
 416         if (dev->driver && drv->suspend)
 417                 ret = drv->suspend(of_dev, mesg);
 418         return ret;
 419 }
 420
 421 static int ibmebus_bus_legacy_resume(struct device *dev)
 422 {
 423         struct platform_device *of_dev = to_platform_device(dev);
 424         struct of_platform_driver *drv = to_of_platform_driver(dev->driver);
 425         int ret = 0;
 426
 427         if (dev->driver && drv->resume)
 428                 ret = drv->resume(of_dev);
 429         return ret;
 430 }
 431
 432 static int ibmebus_bus_pm_prepare(struct device *dev)
 433 {
 434         struct device_driver *drv = dev->driver;
 435         int ret = 0;
 436
 437         if (drv && drv->pm && drv->pm->prepare)
 438                 ret = drv->pm->prepare(dev);
 439
 440         return ret;
 441 }
 442
 443 static void ibmebus_bus_pm_complete(struct device *dev)
 444 {
 445         struct device_driver *drv = dev->driver;
 446
 447         if (drv && drv->pm && drv->pm->complete)
 448                 drv->pm->complete(dev);
 449 }
 450
 451 #ifdef CONFIG_SUSPEND
 452
 453 static int ibmebus_bus_pm_suspend(struct device *dev)
 454 {
 455         struct device_driver *drv = dev->driver;
 456         int ret = 0;
 457
 458         if (!drv)
 459                 return 0;
 460
 461         if (drv->pm) {
 462                 if (drv->pm->suspend)
 463                         ret = drv->pm->suspend(dev);
 464         } else {
 465                 ret = ibmebus_bus_legacy_suspend(dev, PMSG_SUSPEND);
 466         }
 467
 468         return ret;
 469 }
 470
 471 static int ibmebus_bus_pm_suspend_noirq(struct device *dev)
 472 {
 473         struct device_driver *drv = dev->driver;
 474         int ret = 0;
 475
 476         if (!drv)
 477                 return 0;
 478
 479         if (drv->pm) {
 480                 if (drv->pm->suspend_noirq)
 481                         ret = drv->pm->suspend_noirq(dev);
 482         }
 483
 484         return ret;
 485 }
 486
 487 static int ibmebus_bus_pm_resume(struct device *dev)
 488 {
 489         struct device_driver *drv = dev->driver;
 490         int ret = 0;
 491
 492         if (!drv)
 493                 return 0;
 494
 495         if (drv->pm) {
 496                 if (drv->pm->resume)
 497                         ret = drv->pm->resume(dev);
 498         } else {
 499                 ret = ibmebus_bus_legacy_resume(dev);
 500         }
 501
 502         return ret;
 503 }
 504
 505 static int ibmebus_bus_pm_resume_noirq(struct device *dev)
 506 {
 507         struct device_driver *drv = dev->driver;
 508         int ret = 0;
 509
 510         if (!drv)
 511                 return 0;
 512
 513         if (drv->pm) {
 514                 if (drv->pm->resume_noirq)
 515                         ret = drv->pm->resume_noirq(dev);
 516         }
 517
 518         return ret;
 519 }
 520
 521 #else /* !CONFIG_SUSPEND */
 522
 523 #define ibmebus_bus_pm_suspend          NULL
 524 #define ibmebus_bus_pm_resume           NULL
 525 #define ibmebus_bus_pm_suspend_noirq    NULL
 526 #define ibmebus_bus_pm_resume_noirq     NULL
 527
 528 #endif /* !CONFIG_SUSPEND */
 529
 530 #ifdef CONFIG_HIBERNATE_CALLBACKS
 531
 532 static int ibmebus_bus_pm_freeze(struct device *dev)
 533 {
 534         struct device_driver *drv = dev->driver;
 535         int ret = 0;
 536
 537         if (!drv)
 538                 return 0;
 539
 540         if (drv->pm) {
 541                 if (drv->pm->freeze)
 542                         ret = drv->pm->freeze(dev);
 543         } else {
 544                 ret = ibmebus_bus_legacy_suspend(dev, PMSG_FREEZE);
 545         }
 546
 547         return ret;
 548 }
 549
 550 static int ibmebus_bus_pm_freeze_noirq(struct device *dev)
 551 {
 552         struct device_driver *drv = dev->driver;
 553         int ret = 0;
 554
 555         if (!drv)
 556                 return 0;
 557
 558         if (drv->pm) {
 559                 if (drv->pm->freeze_noirq)
 560                         ret = drv->pm->freeze_noirq(dev);
 561         }
 562
 563         return ret;
 564 }
 565
 566 static int ibmebus_bus_pm_thaw(struct device *dev)
 567 {
 568         struct device_driver *drv = dev->driver;
 569         int ret = 0;
 570
 571         if (!drv)
 572                 return 0;
 573
 574         if (drv->pm) {
 575                 if (drv->pm->thaw)
 576                         ret = drv->pm->thaw(dev);
 577         } else {
 578                 ret = ibmebus_bus_legacy_resume(dev);
 579         }
 580
 581         return ret;
 582 }
 583
 584 static int ibmebus_bus_pm_thaw_noirq(struct device *dev)
 585 {
 586         struct device_driver *drv = dev->driver;
 587         int ret = 0;
 588
 589         if (!drv)
 590                 return 0;
 591
 592         if (drv->pm) {
 593                 if (drv->pm->thaw_noirq)
 594                         ret = drv->pm->thaw_noirq(dev);
 595         }
 596
 597         return ret;
 598 }
 599
 600 static int ibmebus_bus_pm_poweroff(struct device *dev)
 601 {
 602         struct device_driver *drv = dev->driver;
 603         int ret = 0;
 604
 605         if (!drv)
 606                 return 0;
 607
 608         if (drv->pm) {
 609                 if (drv->pm->poweroff)
 610                         ret = drv->pm->poweroff(dev);
 611         } else {
 612                 ret = ibmebus_bus_legacy_suspend(dev, PMSG_HIBERNATE);
 613         }
 614
 615         return ret;
 616 }
 617
 618 static int ibmebus_bus_pm_poweroff_noirq(struct device *dev)
 619 {
 620         struct device_driver *drv = dev->driver;
 621         int ret = 0;
 622
 623         if (!drv)
 624                 return 0;
 625
 626         if (drv->pm) {
 627                 if (drv->pm->poweroff_noirq)
 628                         ret = drv->pm->poweroff_noirq(dev);
 629         }
 630
 631         return ret;
 632 }
 633
 634 static int ibmebus_bus_pm_restore(struct device *dev)
 635 {
 636         struct device_driver *drv = dev->driver;
 637         int ret = 0;
 638
 639         if (!drv)
 640                 return 0;
 641
 642         if (drv->pm) {
 643                 if (drv->pm->restore)
 644                         ret = drv->pm->restore(dev);
 645         } else {
 646                 ret = ibmebus_bus_legacy_resume(dev);
 647         }
 648
 649         return ret;
 650 }
 651
 652 static int ibmebus_bus_pm_restore_noirq(struct device *dev)
 653 {
 654         struct device_driver *drv = dev->driver;
 655         int ret = 0;
 656
 657         if (!drv)
 658                 return 0;
 659
 660         if (drv->pm) {
 661                 if (drv->pm->restore_noirq)
 662                         ret = drv->pm->restore_noirq(dev);
 663         }
 664
 665         return ret;
 666 }
 667
 668 #else /* !CONFIG_HIBERNATE_CALLBACKS */
 669
 670 #define ibmebus_bus_pm_freeze           NULL
 671 #define ibmebus_bus_pm_thaw             NULL
 672 #define ibmebus_bus_pm_poweroff         NULL
 673 #define ibmebus_bus_pm_restore          NULL
 674 #define ibmebus_bus_pm_freeze_noirq     NULL
 675 #define ibmebus_bus_pm_thaw_noirq               NULL
 676 #define ibmebus_bus_pm_poweroff_noirq   NULL
 677 #define ibmebus_bus_pm_restore_noirq    NULL
 678
 679 #endif /* !CONFIG_HIBERNATE_CALLBACKS */
 680
 681 static struct dev_pm_ops ibmebus_bus_dev_pm_ops = {
 682         .prepare = ibmebus_bus_pm_prepare,
 683         .complete = ibmebus_bus_pm_complete,
 684         .suspend = ibmebus_bus_pm_suspend,
 685         .resume = ibmebus_bus_pm_resume,
 686         .freeze = ibmebus_bus_pm_freeze,
 687         .thaw = ibmebus_bus_pm_thaw,
 688         .poweroff = ibmebus_bus_pm_poweroff,
 689         .restore = ibmebus_bus_pm_restore,
 690         .suspend_noirq = ibmebus_bus_pm_suspend_noirq,
 691         .resume_noirq = ibmebus_bus_pm_resume_noirq,
 692         .freeze_noirq = ibmebus_bus_pm_freeze_noirq,
 693         .thaw_noirq = ibmebus_bus_pm_thaw_noirq,
 694         .poweroff_noirq = ibmebus_bus_pm_poweroff_noirq,
 695         .restore_noirq = ibmebus_bus_pm_restore_noirq,
 696 };
 697
 698 #define IBMEBUS_BUS_PM_OPS_PTR  (&ibmebus_bus_dev_pm_ops)
 699
 700 #else /* !CONFIG_PM_SLEEP */
 701
 702 #define IBMEBUS_BUS_PM_OPS_PTR  NULL
 703
 704 #endif /* !CONFIG_PM_SLEEP */
 705
 706 struct bus_type ibmebus_bus_type = {
 707         .name      = "ibmebus",
 708         .uevent    = of_device_uevent,
 709         .bus_attrs = ibmebus_bus_attrs,
 710         .match     = ibmebus_bus_bus_match,
 711         .probe     = ibmebus_bus_device_probe,
 712         .remove    = ibmebus_bus_device_remove,
 713         .shutdown  = ibmebus_bus_device_shutdown,
 714         .dev_attrs = ibmebus_bus_device_attrs,
 715         .pm        = IBMEBUS_BUS_PM_OPS_PTR,
 716 };
 717 EXPORT_SYMBOL(ibmebus_bus_type);
 718
 719 static int __init ibmebus_bus_init(void)
 720 {
 721         int err;
 722
 723         printk(KERN_INFO "IBM eBus Device Driver\n");
 724
 725         err = bus_register(&ibmebus_bus_type);
 726         if (err) {
 727                 printk(KERN_ERR "%s: failed to register IBM eBus.\n",
 728                        __func__);
 729                 return err;
 730         }
 731
 732         err = device_register(&ibmebus_bus_device);
 733         if (err) {
 734                 printk(KERN_WARNING "%s: device_register returned %i\n",
 735                        __func__, err);
 736                 bus_unregister(&ibmebus_bus_type);
 737
 738                 return err;
 739         }
 740
 741         err = ibmebus_create_devices(ibmebus_matches);
 742         if (err) {
 743                 device_unregister(&ibmebus_bus_device);
 744                 bus_unregister(&ibmebus_bus_type);
 745                 return err;
 746         }
 747
 748         return 0;
 749 }
 750 postcore_initcall(ibmebus_bus_init);