drivers/pci/endpoint/pci-epc-core.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /**
   3  * PCI Endpoint *Controller* (EPC) library
   4  *
   5  * Copyright (C) 2017 Texas Instruments
   6  * Author: Kishon Vijay Abraham I <kishon@ti.com>
   7  */
   8
   9 #include <linux/device.h>
  10 #include <linux/slab.h>
  11 #include <linux/module.h>
  12 #include <linux/of_device.h>
  13
  14 #include <linux/pci-epc.h>
  15 #include <linux/pci-epf.h>
  16 #include <linux/pci-ep-cfs.h>
  17
  18 static struct class *pci_epc_class;
  19
  20 static void devm_pci_epc_release(struct device *dev, void *res)
  21 {
  22         struct pci_epc *epc = *(struct pci_epc **)res;
  23
  24         pci_epc_destroy(epc);
  25 }
  26
  27 static int devm_pci_epc_match(struct device *dev, void *res, void *match_data)
  28 {
  29         struct pci_epc **epc = res;
  30
  31         return *epc == match_data;
  32 }
  33
  34 /**
  35  * pci_epc_put() - release the PCI endpoint controller
  36  * @epc: epc returned by pci_epc_get()
  37  *
  38  * release the refcount the caller obtained by invoking pci_epc_get()
  39  */
  40 void pci_epc_put(struct pci_epc *epc)
  41 {
  42         if (!epc || IS_ERR(epc))
  43                 return;
  44
  45         module_put(epc->ops->owner);
  46         put_device(&epc->dev);
  47 }
  48 EXPORT_SYMBOL_GPL(pci_epc_put);
  49
  50 /**
  51  * pci_epc_get() - get the PCI endpoint controller
  52  * @epc_name: device name of the endpoint controller
  53  *
  54  * Invoke to get struct pci_epc * corresponding to the device name of the
  55  * endpoint controller
  56  */
  57 struct pci_epc *pci_epc_get(const char *epc_name)
  58 {
  59         int ret = -EINVAL;
  60         struct pci_epc *epc;
  61         struct device *dev;
  62         struct class_dev_iter iter;
  63
  64         class_dev_iter_init(&iter, pci_epc_class, NULL, NULL);
  65         while ((dev = class_dev_iter_next(&iter))) {
  66                 if (strcmp(epc_name, dev_name(dev)))
  67                         continue;
  68
  69                 epc = to_pci_epc(dev);
  70                 if (!try_module_get(epc->ops->owner)) {
  71                         ret = -EINVAL;
  72                         goto err;
  73                 }
  74
  75                 class_dev_iter_exit(&iter);
  76                 get_device(&epc->dev);
  77                 return epc;
  78         }
  79
  80 err:
  81         class_dev_iter_exit(&iter);
  82         return ERR_PTR(ret);
  83 }
  84 EXPORT_SYMBOL_GPL(pci_epc_get);
  85
  86 /**
  87  * pci_epc_get_first_free_bar() - helper to get first unreserved BAR
  88  * @epc_features: pci_epc_features structure that holds the reserved bar bitmap
  89  *
  90  * Invoke to get the first unreserved BAR that can be used for endpoint
  91  * function. For any incorrect value in reserved_bar return '0'.
  92  */
  93 unsigned int pci_epc_get_first_free_bar(const struct pci_epc_features
  94                                         *epc_features)
  95 {
  96         int free_bar;
  97
  98         if (!epc_features)
  99                 return 0;
 100
 101         free_bar = ffz(epc_features->reserved_bar);
 102         if (free_bar > 5)
 103                 return 0;
 104
 105         return free_bar;
 106 }
 107 EXPORT_SYMBOL_GPL(pci_epc_get_first_free_bar);
 108
 109 /**
 110  * pci_epc_get_features() - get the features supported by EPC
 111  * @epc: the features supported by *this* EPC device will be returned
 112  * @func_no: the features supported by the EPC device specific to the
 113  *           endpoint function with func_no will be returned
 114  *
 115  * Invoke to get the features provided by the EPC which may be
 116  * specific to an endpoint function. Returns pci_epc_features on success
 117  * and NULL for any failures.
 118  */
 119 const struct pci_epc_features *pci_epc_get_features(struct pci_epc *epc,
 120                                                     u8 func_no)
 121 {
 122         const struct pci_epc_features *epc_features;
 123         unsigned long flags;
 124
 125         if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions)
 126                 return NULL;
 127
 128         if (!epc->ops->get_features)
 129                 return NULL;
 130
 131         spin_lock_irqsave(&epc->lock, flags);
 132         epc_features = epc->ops->get_features(epc, func_no);
 133         spin_unlock_irqrestore(&epc->lock, flags);
 134
 135         return epc_features;
 136 }
 137 EXPORT_SYMBOL_GPL(pci_epc_get_features);
 138
 139 /**
 140  * pci_epc_stop() - stop the PCI link
 141  * @epc: the link of the EPC device that has to be stopped
 142  *
 143  * Invoke to stop the PCI link
 144  */
 145 void pci_epc_stop(struct pci_epc *epc)
 146 {
 147         unsigned long flags;
 148
 149         if (IS_ERR(epc) || !epc->ops->stop)
 150                 return;
 151
 152         spin_lock_irqsave(&epc->lock, flags);
 153         epc->ops->stop(epc);
 154         spin_unlock_irqrestore(&epc->lock, flags);
 155 }
 156 EXPORT_SYMBOL_GPL(pci_epc_stop);
 157
 158 /**
 159  * pci_epc_start() - start the PCI link
 160  * @epc: the link of *this* EPC device has to be started
 161  *
 162  * Invoke to start the PCI link
 163  */
 164 int pci_epc_start(struct pci_epc *epc)
 165 {
 166         int ret;
 167         unsigned long flags;
 168
 169         if (IS_ERR(epc))
 170                 return -EINVAL;
 171
 172         if (!epc->ops->start)
 173                 return 0;
 174
 175         spin_lock_irqsave(&epc->lock, flags);
 176         ret = epc->ops->start(epc);
 177         spin_unlock_irqrestore(&epc->lock, flags);
 178
 179         return ret;
 180 }
 181 EXPORT_SYMBOL_GPL(pci_epc_start);
 182
 183 /**
 184  * pci_epc_raise_irq() - interrupt the host system
 185  * @epc: the EPC device which has to interrupt the host
 186  * @func_no: the endpoint function number in the EPC device
 187  * @type: specify the type of interrupt; legacy, MSI or MSI-X
 188  * @interrupt_num: the MSI or MSI-X interrupt number
 189  *
 190  * Invoke to raise an legacy, MSI or MSI-X interrupt
 191  */
 192 int pci_epc_raise_irq(struct pci_epc *epc, u8 func_no,
 193                       enum pci_epc_irq_type type, u16 interrupt_num)
 194 {
 195         int ret;
 196         unsigned long flags;
 197
 198         if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions)
 199                 return -EINVAL;
 200
 201         if (!epc->ops->raise_irq)
 202                 return 0;
 203
 204         spin_lock_irqsave(&epc->lock, flags);
 205         ret = epc->ops->raise_irq(epc, func_no, type, interrupt_num);
 206         spin_unlock_irqrestore(&epc->lock, flags);
 207
 208         return ret;
 209 }
 210 EXPORT_SYMBOL_GPL(pci_epc_raise_irq);
 211
 212 /**
 213  * pci_epc_get_msi() - get the number of MSI interrupt numbers allocated
 214  * @epc: the EPC device to which MSI interrupts was requested
 215  * @func_no: the endpoint function number in the EPC device
 216  *
 217  * Invoke to get the number of MSI interrupts allocated by the RC
 218  */
 219 int pci_epc_get_msi(struct pci_epc *epc, u8 func_no)
 220 {
 221         int interrupt;
 222         unsigned long flags;
 223
 224         if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions)
 225                 return 0;
 226
 227         if (!epc->ops->get_msi)
 228                 return 0;
 229
 230         spin_lock_irqsave(&epc->lock, flags);
 231         interrupt = epc->ops->get_msi(epc, func_no);
 232         spin_unlock_irqrestore(&epc->lock, flags);
 233
 234         if (interrupt < 0)
 235                 return 0;
 236
 237         interrupt = 1 << interrupt;
 238
 239         return interrupt;
 240 }
 241 EXPORT_SYMBOL_GPL(pci_epc_get_msi);
 242
 243 /**
 244  * pci_epc_set_msi() - set the number of MSI interrupt numbers required
 245  * @epc: the EPC device on which MSI has to be configured
 246  * @func_no: the endpoint function number in the EPC device
 247  * @interrupts: number of MSI interrupts required by the EPF
 248  *
 249  * Invoke to set the required number of MSI interrupts.
 250  */
 251 int pci_epc_set_msi(struct pci_epc *epc, u8 func_no, u8 interrupts)
 252 {
 253         int ret;
 254         u8 encode_int;
 255         unsigned long flags;
 256
 257         if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions ||
 258             interrupts > 32)
 259                 return -EINVAL;
 260
 261         if (!epc->ops->set_msi)
 262                 return 0;
 263
 264         encode_int = order_base_2(interrupts);
 265
 266         spin_lock_irqsave(&epc->lock, flags);
 267         ret = epc->ops->set_msi(epc, func_no, encode_int);
 268         spin_unlock_irqrestore(&epc->lock, flags);
 269
 270         return ret;
 271 }
 272 EXPORT_SYMBOL_GPL(pci_epc_set_msi);
 273
 274 /**
 275  * pci_epc_get_msix() - get the number of MSI-X interrupt numbers allocated
 276  * @epc: the EPC device to which MSI-X interrupts was requested
 277  * @func_no: the endpoint function number in the EPC device
 278  *
 279  * Invoke to get the number of MSI-X interrupts allocated by the RC
 280  */
 281 int pci_epc_get_msix(struct pci_epc *epc, u8 func_no)
 282 {
 283         int interrupt;
 284         unsigned long flags;
 285
 286         if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions)
 287                 return 0;
 288
 289         if (!epc->ops->get_msix)
 290                 return 0;
 291
 292         spin_lock_irqsave(&epc->lock, flags);
 293         interrupt = epc->ops->get_msix(epc, func_no);
 294         spin_unlock_irqrestore(&epc->lock, flags);
 295
 296         if (interrupt < 0)
 297                 return 0;
 298
 299         return interrupt + 1;
 300 }
 301 EXPORT_SYMBOL_GPL(pci_epc_get_msix);
 302
 303 /**
 304  * pci_epc_set_msix() - set the number of MSI-X interrupt numbers required
 305  * @epc: the EPC device on which MSI-X has to be configured
 306  * @func_no: the endpoint function number in the EPC device
 307  * @interrupts: number of MSI-X interrupts required by the EPF
 308  *
 309  * Invoke to set the required number of MSI-X interrupts.
 310  */
 311 int pci_epc_set_msix(struct pci_epc *epc, u8 func_no, u16 interrupts)
 312 {
 313         int ret;
 314         unsigned long flags;
 315
 316         if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions ||
 317             interrupts < 1 || interrupts > 2048)
 318                 return -EINVAL;
 319
 320         if (!epc->ops->set_msix)
 321                 return 0;
 322
 323         spin_lock_irqsave(&epc->lock, flags);
 324         ret = epc->ops->set_msix(epc, func_no, interrupts - 1);
 325         spin_unlock_irqrestore(&epc->lock, flags);
 326
 327         return ret;
 328 }
 329 EXPORT_SYMBOL_GPL(pci_epc_set_msix);
 330
 331 /**
 332  * pci_epc_unmap_addr() - unmap CPU address from PCI address
 333  * @epc: the EPC device on which address is allocated
 334  * @func_no: the endpoint function number in the EPC device
 335  * @phys_addr: physical address of the local system
 336  *
 337  * Invoke to unmap the CPU address from PCI address.
 338  */
 339 void pci_epc_unmap_addr(struct pci_epc *epc, u8 func_no,
 340                         phys_addr_t phys_addr)
 341 {
 342         unsigned long flags;
 343
 344         if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions)
 345                 return;
 346
 347         if (!epc->ops->unmap_addr)
 348                 return;
 349
 350         spin_lock_irqsave(&epc->lock, flags);
 351         epc->ops->unmap_addr(epc, func_no, phys_addr);
 352         spin_unlock_irqrestore(&epc->lock, flags);
 353 }
 354 EXPORT_SYMBOL_GPL(pci_epc_unmap_addr);
 355
 356 /**
 357  * pci_epc_map_addr() - map CPU address to PCI address
 358  * @epc: the EPC device on which address is allocated
 359  * @func_no: the endpoint function number in the EPC device
 360  * @phys_addr: physical address of the local system
 361  * @pci_addr: PCI address to which the physical address should be mapped
 362  * @size: the size of the allocation
 363  *
 364  * Invoke to map CPU address with PCI address.
 365  */
 366 int pci_epc_map_addr(struct pci_epc *epc, u8 func_no,
 367                      phys_addr_t phys_addr, u64 pci_addr, size_t size)
 368 {
 369         int ret;
 370         unsigned long flags;
 371
 372         if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions)
 373                 return -EINVAL;
 374
 375         if (!epc->ops->map_addr)
 376                 return 0;
 377
 378         spin_lock_irqsave(&epc->lock, flags);
 379         ret = epc->ops->map_addr(epc, func_no, phys_addr, pci_addr, size);
 380         spin_unlock_irqrestore(&epc->lock, flags);
 381
 382         return ret;
 383 }
 384 EXPORT_SYMBOL_GPL(pci_epc_map_addr);
 385
 386 /**
 387  * pci_epc_clear_bar() - reset the BAR
 388  * @epc: the EPC device for which the BAR has to be cleared
 389  * @func_no: the endpoint function number in the EPC device
 390  * @epf_bar: the struct epf_bar that contains the BAR information
 391  *
 392  * Invoke to reset the BAR of the endpoint device.
 393  */
 394 void pci_epc_clear_bar(struct pci_epc *epc, u8 func_no,
 395                        struct pci_epf_bar *epf_bar)
 396 {
 397         unsigned long flags;
 398
 399         if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions ||
 400             (epf_bar->barno == BAR_5 &&
 401              epf_bar->flags & PCI_BASE_ADDRESS_MEM_TYPE_64))
 402                 return;
 403
 404         if (!epc->ops->clear_bar)
 405                 return;
 406
 407         spin_lock_irqsave(&epc->lock, flags);
 408         epc->ops->clear_bar(epc, func_no, epf_bar);
 409         spin_unlock_irqrestore(&epc->lock, flags);
 410 }
 411 EXPORT_SYMBOL_GPL(pci_epc_clear_bar);
 412
 413 /**
 414  * pci_epc_set_bar() - configure BAR in order for host to assign PCI addr space
 415  * @epc: the EPC device on which BAR has to be configured
 416  * @func_no: the endpoint function number in the EPC device
 417  * @epf_bar: the struct epf_bar that contains the BAR information
 418  *
 419  * Invoke to configure the BAR of the endpoint device.
 420  */
 421 int pci_epc_set_bar(struct pci_epc *epc, u8 func_no,
 422                     struct pci_epf_bar *epf_bar)
 423 {
 424         int ret;
 425         unsigned long irq_flags;
 426         int flags = epf_bar->flags;
 427
 428         if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions ||
 429             (epf_bar->barno == BAR_5 &&
 430              flags & PCI_BASE_ADDRESS_MEM_TYPE_64) ||
 431             (flags & PCI_BASE_ADDRESS_SPACE_IO &&
 432              flags & PCI_BASE_ADDRESS_IO_MASK) ||
 433             (upper_32_bits(epf_bar->size) &&
 434              !(flags & PCI_BASE_ADDRESS_MEM_TYPE_64)))
 435                 return -EINVAL;
 436
 437         if (!epc->ops->set_bar)
 438                 return 0;
 439
 440         spin_lock_irqsave(&epc->lock, irq_flags);
 441         ret = epc->ops->set_bar(epc, func_no, epf_bar);
 442         spin_unlock_irqrestore(&epc->lock, irq_flags);
 443
 444         return ret;
 445 }
 446 EXPORT_SYMBOL_GPL(pci_epc_set_bar);
 447
 448 /**
 449  * pci_epc_write_header() - write standard configuration header
 450  * @epc: the EPC device to which the configuration header should be written
 451  * @func_no: the endpoint function number in the EPC device
 452  * @header: standard configuration header fields
 453  *
 454  * Invoke to write the configuration header to the endpoint controller. Every
 455  * endpoint controller will have a dedicated location to which the standard
 456  * configuration header would be written. The callback function should write
 457  * the header fields to this dedicated location.
 458  */
 459 int pci_epc_write_header(struct pci_epc *epc, u8 func_no,
 460                          struct pci_epf_header *header)
 461 {
 462         int ret;
 463         unsigned long flags;
 464
 465         if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions)
 466                 return -EINVAL;
 467
 468         if (!epc->ops->write_header)
 469                 return 0;
 470
 471         spin_lock_irqsave(&epc->lock, flags);
 472         ret = epc->ops->write_header(epc, func_no, header);
 473         spin_unlock_irqrestore(&epc->lock, flags);
 474
 475         return ret;
 476 }
 477 EXPORT_SYMBOL_GPL(pci_epc_write_header);
 478
 479 /**
 480  * pci_epc_add_epf() - bind PCI endpoint function to an endpoint controller
 481  * @epc: the EPC device to which the endpoint function should be added
 482  * @epf: the endpoint function to be added
 483  *
 484  * A PCI endpoint device can have one or more functions. In the case of PCIe,
 485  * the specification allows up to 8 PCIe endpoint functions. Invoke
 486  * pci_epc_add_epf() to add a PCI endpoint function to an endpoint controller.
 487  */
 488 int pci_epc_add_epf(struct pci_epc *epc, struct pci_epf *epf)
 489 {
 490         unsigned long flags;
 491
 492         if (epf->epc)
 493                 return -EBUSY;
 494
 495         if (IS_ERR(epc))
 496                 return -EINVAL;
 497
 498         if (epf->func_no > epc->max_functions - 1)
 499                 return -EINVAL;
 500
 501         epf->epc = epc;
 502
 503         spin_lock_irqsave(&epc->lock, flags);
 504         list_add_tail(&epf->list, &epc->pci_epf);
 505         spin_unlock_irqrestore(&epc->lock, flags);
 506
 507         return 0;
 508 }
 509 EXPORT_SYMBOL_GPL(pci_epc_add_epf);
 510
 511 /**
 512  * pci_epc_remove_epf() - remove PCI endpoint function from endpoint controller
 513  * @epc: the EPC device from which the endpoint function should be removed
 514  * @epf: the endpoint function to be removed
 515  *
 516  * Invoke to remove PCI endpoint function from the endpoint controller.
 517  */
 518 void pci_epc_remove_epf(struct pci_epc *epc, struct pci_epf *epf)
 519 {
 520         unsigned long flags;
 521
 522         if (!epc || IS_ERR(epc) || !epf)
 523                 return;
 524
 525         spin_lock_irqsave(&epc->lock, flags);
 526         list_del(&epf->list);
 527         epf->epc = NULL;
 528         spin_unlock_irqrestore(&epc->lock, flags);
 529 }
 530 EXPORT_SYMBOL_GPL(pci_epc_remove_epf);
 531
 532 /**
 533  * pci_epc_linkup() - Notify the EPF device that EPC device has established a
 534  *                    connection with the Root Complex.
 535  * @epc: the EPC device which has established link with the host
 536  *
 537  * Invoke to Notify the EPF device that the EPC device has established a
 538  * connection with the Root Complex.
 539  */
 540 void pci_epc_linkup(struct pci_epc *epc)
 541 {
 542         unsigned long flags;
 543         struct pci_epf *epf;
 544
 545         if (!epc || IS_ERR(epc))
 546                 return;
 547
 548         spin_lock_irqsave(&epc->lock, flags);
 549         list_for_each_entry(epf, &epc->pci_epf, list)
 550                 pci_epf_linkup(epf);
 551         spin_unlock_irqrestore(&epc->lock, flags);
 552 }
 553 EXPORT_SYMBOL_GPL(pci_epc_linkup);
 554
 555 /**
 556  * pci_epc_destroy() - destroy the EPC device
 557  * @epc: the EPC device that has to be destroyed
 558  *
 559  * Invoke to destroy the PCI EPC device
 560  */
 561 void pci_epc_destroy(struct pci_epc *epc)
 562 {
 563         pci_ep_cfs_remove_epc_group(epc->group);
 564         device_unregister(&epc->dev);
 565         kfree(epc);
 566 }
 567 EXPORT_SYMBOL_GPL(pci_epc_destroy);
 568
 569 /**
 570  * devm_pci_epc_destroy() - destroy the EPC device
 571  * @dev: device that wants to destroy the EPC
 572  * @epc: the EPC device that has to be destroyed
 573  *
 574  * Invoke to destroy the devres associated with this
 575  * pci_epc and destroy the EPC device.
 576  */
 577 void devm_pci_epc_destroy(struct device *dev, struct pci_epc *epc)
 578 {
 579         int r;
 580
 581         r = devres_destroy(dev, devm_pci_epc_release, devm_pci_epc_match,
 582                            epc);
 583         dev_WARN_ONCE(dev, r, "couldn't find PCI EPC resource\n");
 584 }
 585 EXPORT_SYMBOL_GPL(devm_pci_epc_destroy);
 586
 587 /**
 588  * __pci_epc_create() - create a new endpoint controller (EPC) device
 589  * @dev: device that is creating the new EPC
 590  * @ops: function pointers for performing EPC operations
 591  * @owner: the owner of the module that creates the EPC device
 592  *
 593  * Invoke to create a new EPC device and add it to pci_epc class.
 594  */
 595 struct pci_epc *
 596 __pci_epc_create(struct device *dev, const struct pci_epc_ops *ops,
 597                  struct module *owner)
 598 {
 599         int ret;
 600         struct pci_epc *epc;
 601
 602         if (WARN_ON(!dev)) {
 603                 ret = -EINVAL;
 604                 goto err_ret;
 605         }
 606
 607         epc = kzalloc(sizeof(*epc), GFP_KERNEL);
 608         if (!epc) {
 609                 ret = -ENOMEM;
 610                 goto err_ret;
 611         }
 612
 613         spin_lock_init(&epc->lock);
 614         INIT_LIST_HEAD(&epc->pci_epf);
 615
 616         device_initialize(&epc->dev);
 617         epc->dev.class = pci_epc_class;
 618         epc->dev.parent = dev;
 619         epc->ops = ops;
 620
 621         ret = dev_set_name(&epc->dev, "%s", dev_name(dev));
 622         if (ret)
 623                 goto put_dev;
 624
 625         ret = device_add(&epc->dev);
 626         if (ret)
 627                 goto put_dev;
 628
 629         epc->group = pci_ep_cfs_add_epc_group(dev_name(dev));
 630
 631         return epc;
 632
 633 put_dev:
 634         put_device(&epc->dev);
 635         kfree(epc);
 636
 637 err_ret:
 638         return ERR_PTR(ret);
 639 }
 640 EXPORT_SYMBOL_GPL(__pci_epc_create);
 641
 642 /**
 643  * __devm_pci_epc_create() - create a new endpoint controller (EPC) device
 644  * @dev: device that is creating the new EPC
 645  * @ops: function pointers for performing EPC operations
 646  * @owner: the owner of the module that creates the EPC device
 647  *
 648  * Invoke to create a new EPC device and add it to pci_epc class.
 649  * While at that, it also associates the device with the pci_epc using devres.
 650  * On driver detach, release function is invoked on the devres data,
 651  * then, devres data is freed.
 652  */
 653 struct pci_epc *
 654 __devm_pci_epc_create(struct device *dev, const struct pci_epc_ops *ops,
 655                       struct module *owner)
 656 {
 657         struct pci_epc **ptr, *epc;
 658
 659         ptr = devres_alloc(devm_pci_epc_release, sizeof(*ptr), GFP_KERNEL);
 660         if (!ptr)
 661                 return ERR_PTR(-ENOMEM);
 662
 663         epc = __pci_epc_create(dev, ops, owner);
 664         if (!IS_ERR(epc)) {
 665                 *ptr = epc;
 666                 devres_add(dev, ptr);
 667         } else {
 668                 devres_free(ptr);
 669         }
 670
 671         return epc;
 672 }
 673 EXPORT_SYMBOL_GPL(__devm_pci_epc_create);
 674
 675 static int __init pci_epc_init(void)
 676 {
 677         pci_epc_class = class_create(THIS_MODULE, "pci_epc");
 678         if (IS_ERR(pci_epc_class)) {
 679                 pr_err("failed to create pci epc class --> %ld\n",
 680                        PTR_ERR(pci_epc_class));
 681                 return PTR_ERR(pci_epc_class);
 682         }
 683
 684         return 0;
 685 }
 686 module_init(pci_epc_init);
 687
 688 static void __exit pci_epc_exit(void)
 689 {
 690         class_destroy(pci_epc_class);
 691 }
 692 module_exit(pci_epc_exit);
 693
 694 MODULE_DESCRIPTION("PCI EPC Library");
 695 MODULE_AUTHOR("Kishon Vijay Abraham I <kishon@ti.com>");
 696 MODULE_LICENSE("GPL v2");