1 /* 2 * drivers/uio/uio.c 3 * 4 * Copyright(C) 2005, Benedikt Spranger <b.spranger@linutronix.de> 5 * Copyright(C) 2005, Thomas Gleixner <tglx@linutronix.de> 6 * Copyright(C) 2006, Hans J. Koch <hjk@hansjkoch.de> 7 * Copyright(C) 2006, Greg Kroah-Hartman <greg@kroah.com> 8 * 9 * Userspace IO 10 * 11 * Base Functions 12 * 13 * Licensed under the GPLv2 only. 14 */ 15 16 #include <linux/module.h> 17 #include <linux/init.h> 18 #include <linux/poll.h> 19 #include <linux/device.h> 20 #include <linux/slab.h> 21 #include <linux/mm.h> 22 #include <linux/idr.h> 23 #include <linux/sched.h> 24 #include <linux/string.h> 25 #include <linux/kobject.h> 26 #include <linux/cdev.h> 27 #include <linux/uio_driver.h> 28 29 #define UIO_MAX_DEVICES (1U << MINORBITS) 30 31 static int uio_major; 32 static struct cdev *uio_cdev; 33 static DEFINE_IDR(uio_idr); 34 static const struct file_operations uio_fops; 35 36 /* Protect idr accesses */ 37 static DEFINE_MUTEX(minor_lock); 38 39 /* 40 * attributes 41 */ 42 43 struct uio_map { 44 struct kobject kobj; 45 struct uio_mem *mem; 46 }; 47 #define to_map(map) container_of(map, struct uio_map, kobj) 48 49 static ssize_t map_name_show(struct uio_mem *mem, char *buf) 50 { 51 if (unlikely(!mem->name)) 52 mem->name = ""; 53 54 return sprintf(buf, "%s\n", mem->name); 55 } 56 57 static ssize_t map_addr_show(struct uio_mem *mem, char *buf) 58 { 59 return sprintf(buf, "%pa\n", &mem->addr); 60 } 61 62 static ssize_t map_size_show(struct uio_mem *mem, char *buf) 63 { 64 return sprintf(buf, "%pa\n", &mem->size); 65 } 66 67 static ssize_t map_offset_show(struct uio_mem *mem, char *buf) 68 { 69 return sprintf(buf, "0x%llx\n", (unsigned long long)mem->addr & ~PAGE_MASK); 70 } 71 72 struct map_sysfs_entry { 73 struct attribute attr; 74 ssize_t (*show)(struct uio_mem *, char *); 75 ssize_t (*store)(struct uio_mem *, const char *, size_t); 76 }; 77 78 static struct map_sysfs_entry name_attribute = 79 __ATTR(name, S_IRUGO, map_name_show, NULL); 80 static struct map_sysfs_entry addr_attribute = 81 __ATTR(addr, S_IRUGO, map_addr_show, NULL); 82 static struct map_sysfs_entry size_attribute = 83 __ATTR(size, S_IRUGO, map_size_show, NULL); 84 static struct map_sysfs_entry offset_attribute = 85 __ATTR(offset, S_IRUGO, map_offset_show, NULL); 86 87 static struct attribute *attrs[] = { 88 &name_attribute.attr, 89 &addr_attribute.attr, 90 &size_attribute.attr, 91 &offset_attribute.attr, 92 NULL, /* need to NULL terminate the list of attributes */ 93 }; 94 95 static void map_release(struct kobject *kobj) 96 { 97 struct uio_map *map = to_map(kobj); 98 kfree(map); 99 } 100 101 static ssize_t map_type_show(struct kobject *kobj, struct attribute *attr, 102 char *buf) 103 { 104 struct uio_map *map = to_map(kobj); 105 struct uio_mem *mem = map->mem; 106 struct map_sysfs_entry *entry; 107 108 entry = container_of(attr, struct map_sysfs_entry, attr); 109 110 if (!entry->show) 111 return -EIO; 112 113 return entry->show(mem, buf); 114 } 115 116 static const struct sysfs_ops map_sysfs_ops = { 117 .show = map_type_show, 118 }; 119 120 static struct kobj_type map_attr_type = { 121 .release = map_release, 122 .sysfs_ops = &map_sysfs_ops, 123 .default_attrs = attrs, 124 }; 125 126 struct uio_portio { 127 struct kobject kobj; 128 struct uio_port *port; 129 }; 130 #define to_portio(portio) container_of(portio, struct uio_portio, kobj) 131 132 static ssize_t portio_name_show(struct uio_port *port, char *buf) 133 { 134 if (unlikely(!port->name)) 135 port->name = ""; 136 137 return sprintf(buf, "%s\n", port->name); 138 } 139 140 static ssize_t portio_start_show(struct uio_port *port, char *buf) 141 { 142 return sprintf(buf, "0x%lx\n", port->start); 143 } 144 145 static ssize_t portio_size_show(struct uio_port *port, char *buf) 146 { 147 return sprintf(buf, "0x%lx\n", port->size); 148 } 149 150 static ssize_t portio_porttype_show(struct uio_port *port, char *buf) 151 { 152 const char *porttypes[] = {"none", "x86", "gpio", "other"}; 153 154 if ((port->porttype < 0) || (port->porttype > UIO_PORT_OTHER)) 155 return -EINVAL; 156 157 return sprintf(buf, "port_%s\n", porttypes[port->porttype]); 158 } 159 160 struct portio_sysfs_entry { 161 struct attribute attr; 162 ssize_t (*show)(struct uio_port *, char *); 163 ssize_t (*store)(struct uio_port *, const char *, size_t); 164 }; 165 166 static struct portio_sysfs_entry portio_name_attribute = 167 __ATTR(name, S_IRUGO, portio_name_show, NULL); 168 static struct portio_sysfs_entry portio_start_attribute = 169 __ATTR(start, S_IRUGO, portio_start_show, NULL); 170 static struct portio_sysfs_entry portio_size_attribute = 171 __ATTR(size, S_IRUGO, portio_size_show, NULL); 172 static struct portio_sysfs_entry portio_porttype_attribute = 173 __ATTR(porttype, S_IRUGO, portio_porttype_show, NULL); 174 175 static struct attribute *portio_attrs[] = { 176 &portio_name_attribute.attr, 177 &portio_start_attribute.attr, 178 &portio_size_attribute.attr, 179 &portio_porttype_attribute.attr, 180 NULL, 181 }; 182 183 static void portio_release(struct kobject *kobj) 184 { 185 struct uio_portio *portio = to_portio(kobj); 186 kfree(portio); 187 } 188 189 static ssize_t portio_type_show(struct kobject *kobj, struct attribute *attr, 190 char *buf) 191 { 192 struct uio_portio *portio = to_portio(kobj); 193 struct uio_port *port = portio->port; 194 struct portio_sysfs_entry *entry; 195 196 entry = container_of(attr, struct portio_sysfs_entry, attr); 197 198 if (!entry->show) 199 return -EIO; 200 201 return entry->show(port, buf); 202 } 203 204 static const struct sysfs_ops portio_sysfs_ops = { 205 .show = portio_type_show, 206 }; 207 208 static struct kobj_type portio_attr_type = { 209 .release = portio_release, 210 .sysfs_ops = &portio_sysfs_ops, 211 .default_attrs = portio_attrs, 212 }; 213 214 static ssize_t name_show(struct device *dev, 215 struct device_attribute *attr, char *buf) 216 { 217 struct uio_device *idev = dev_get_drvdata(dev); 218 return sprintf(buf, "%s\n", idev->info->name); 219 } 220 static DEVICE_ATTR_RO(name); 221 222 static ssize_t version_show(struct device *dev, 223 struct device_attribute *attr, char *buf) 224 { 225 struct uio_device *idev = dev_get_drvdata(dev); 226 return sprintf(buf, "%s\n", idev->info->version); 227 } 228 static DEVICE_ATTR_RO(version); 229 230 static ssize_t event_show(struct device *dev, 231 struct device_attribute *attr, char *buf) 232 { 233 struct uio_device *idev = dev_get_drvdata(dev); 234 return sprintf(buf, "%u\n", (unsigned int)atomic_read(&idev->event)); 235 } 236 static DEVICE_ATTR_RO(event); 237 238 static struct attribute *uio_attrs[] = { 239 &dev_attr_name.attr, 240 &dev_attr_version.attr, 241 &dev_attr_event.attr, 242 NULL, 243 }; 244 ATTRIBUTE_GROUPS(uio); 245 246 /* UIO class infrastructure */ 247 static struct class uio_class = { 248 .name = "uio", 249 .dev_groups = uio_groups, 250 }; 251 252 /* 253 * device functions 254 */ 255 static int uio_dev_add_attributes(struct uio_device *idev) 256 { 257 int ret; 258 int mi, pi; 259 int map_found = 0; 260 int portio_found = 0; 261 struct uio_mem *mem; 262 struct uio_map *map; 263 struct uio_port *port; 264 struct uio_portio *portio; 265 266 for (mi = 0; mi < MAX_UIO_MAPS; mi++) { 267 mem = &idev->info->mem[mi]; 268 if (mem->size == 0) 269 break; 270 if (!map_found) { 271 map_found = 1; 272 idev->map_dir = kobject_create_and_add("maps", 273 &idev->dev->kobj); 274 if (!idev->map_dir) 275 goto err_map; 276 } 277 map = kzalloc(sizeof(*map), GFP_KERNEL); 278 if (!map) 279 goto err_map_kobj; 280 kobject_init(&map->kobj, &map_attr_type); 281 map->mem = mem; 282 mem->map = map; 283 ret = kobject_add(&map->kobj, idev->map_dir, "map%d", mi); 284 if (ret) 285 goto err_map_kobj; 286 ret = kobject_uevent(&map->kobj, KOBJ_ADD); 287 if (ret) 288 goto err_map; 289 } 290 291 for (pi = 0; pi < MAX_UIO_PORT_REGIONS; pi++) { 292 port = &idev->info->port[pi]; 293 if (port->size == 0) 294 break; 295 if (!portio_found) { 296 portio_found = 1; 297 idev->portio_dir = kobject_create_and_add("portio", 298 &idev->dev->kobj); 299 if (!idev->portio_dir) 300 goto err_portio; 301 } 302 portio = kzalloc(sizeof(*portio), GFP_KERNEL); 303 if (!portio) 304 goto err_portio_kobj; 305 kobject_init(&portio->kobj, &portio_attr_type); 306 portio->port = port; 307 port->portio = portio; 308 ret = kobject_add(&portio->kobj, idev->portio_dir, 309 "port%d", pi); 310 if (ret) 311 goto err_portio_kobj; 312 ret = kobject_uevent(&portio->kobj, KOBJ_ADD); 313 if (ret) 314 goto err_portio; 315 } 316 317 return 0; 318 319 err_portio: 320 pi--; 321 err_portio_kobj: 322 for (; pi >= 0; pi--) { 323 port = &idev->info->port[pi]; 324 portio = port->portio; 325 kobject_put(&portio->kobj); 326 } 327 kobject_put(idev->portio_dir); 328 err_map: 329 mi--; 330 err_map_kobj: 331 for (; mi >= 0; mi--) { 332 mem = &idev->info->mem[mi]; 333 map = mem->map; 334 kobject_put(&map->kobj); 335 } 336 kobject_put(idev->map_dir); 337 dev_err(idev->dev, "error creating sysfs files (%d)\n", ret); 338 return ret; 339 } 340 341 static void uio_dev_del_attributes(struct uio_device *idev) 342 { 343 int i; 344 struct uio_mem *mem; 345 struct uio_port *port; 346 347 for (i = 0; i < MAX_UIO_MAPS; i++) { 348 mem = &idev->info->mem[i]; 349 if (mem->size == 0) 350 break; 351 kobject_put(&mem->map->kobj); 352 } 353 kobject_put(idev->map_dir); 354 355 for (i = 0; i < MAX_UIO_PORT_REGIONS; i++) { 356 port = &idev->info->port[i]; 357 if (port->size == 0) 358 break; 359 kobject_put(&port->portio->kobj); 360 } 361 kobject_put(idev->portio_dir); 362 } 363 364 static int uio_get_minor(struct uio_device *idev) 365 { 366 int retval = -ENOMEM; 367 368 mutex_lock(&minor_lock); 369 retval = idr_alloc(&uio_idr, idev, 0, UIO_MAX_DEVICES, GFP_KERNEL); 370 if (retval >= 0) { 371 idev->minor = retval; 372 retval = 0; 373 } else if (retval == -ENOSPC) { 374 dev_err(idev->dev, "too many uio devices\n"); 375 retval = -EINVAL; 376 } 377 mutex_unlock(&minor_lock); 378 return retval; 379 } 380 381 static void uio_free_minor(struct uio_device *idev) 382 { 383 mutex_lock(&minor_lock); 384 idr_remove(&uio_idr, idev->minor); 385 mutex_unlock(&minor_lock); 386 } 387 388 /** 389 * uio_event_notify - trigger an interrupt event 390 * @info: UIO device capabilities 391 */ 392 void uio_event_notify(struct uio_info *info) 393 { 394 struct uio_device *idev = info->uio_dev; 395 396 atomic_inc(&idev->event); 397 wake_up_interruptible(&idev->wait); 398 kill_fasync(&idev->async_queue, SIGIO, POLL_IN); 399 } 400 EXPORT_SYMBOL_GPL(uio_event_notify); 401 402 /** 403 * uio_interrupt - hardware interrupt handler 404 * @irq: IRQ number, can be UIO_IRQ_CYCLIC for cyclic timer 405 * @dev_id: Pointer to the devices uio_device structure 406 */ 407 static irqreturn_t uio_interrupt(int irq, void *dev_id) 408 { 409 struct uio_device *idev = (struct uio_device *)dev_id; 410 irqreturn_t ret = idev->info->handler(irq, idev->info); 411 412 if (ret == IRQ_HANDLED) 413 uio_event_notify(idev->info); 414 415 return ret; 416 } 417 418 struct uio_listener { 419 struct uio_device *dev; 420 s32 event_count; 421 }; 422 423 static int uio_open(struct inode *inode, struct file *filep) 424 { 425 struct uio_device *idev; 426 struct uio_listener *listener; 427 int ret = 0; 428 429 mutex_lock(&minor_lock); 430 idev = idr_find(&uio_idr, iminor(inode)); 431 mutex_unlock(&minor_lock); 432 if (!idev) { 433 ret = -ENODEV; 434 goto out; 435 } 436 437 if (!try_module_get(idev->owner)) { 438 ret = -ENODEV; 439 goto out; 440 } 441 442 listener = kmalloc(sizeof(*listener), GFP_KERNEL); 443 if (!listener) { 444 ret = -ENOMEM; 445 goto err_alloc_listener; 446 } 447 448 listener->dev = idev; 449 listener->event_count = atomic_read(&idev->event); 450 filep->private_data = listener; 451 452 if (idev->info->open) { 453 ret = idev->info->open(idev->info, inode); 454 if (ret) 455 goto err_infoopen; 456 } 457 return 0; 458 459 err_infoopen: 460 kfree(listener); 461 462 err_alloc_listener: 463 module_put(idev->owner); 464 465 out: 466 return ret; 467 } 468 469 static int uio_fasync(int fd, struct file *filep, int on) 470 { 471 struct uio_listener *listener = filep->private_data; 472 struct uio_device *idev = listener->dev; 473 474 return fasync_helper(fd, filep, on, &idev->async_queue); 475 } 476 477 static int uio_release(struct inode *inode, struct file *filep) 478 { 479 int ret = 0; 480 struct uio_listener *listener = filep->private_data; 481 struct uio_device *idev = listener->dev; 482 483 if (idev->info->release) 484 ret = idev->info->release(idev->info, inode); 485 486 module_put(idev->owner); 487 kfree(listener); 488 return ret; 489 } 490 491 static unsigned int uio_poll(struct file *filep, poll_table *wait) 492 { 493 struct uio_listener *listener = filep->private_data; 494 struct uio_device *idev = listener->dev; 495 496 if (!idev->info->irq) 497 return -EIO; 498 499 poll_wait(filep, &idev->wait, wait); 500 if (listener->event_count != atomic_read(&idev->event)) 501 return POLLIN | POLLRDNORM; 502 return 0; 503 } 504 505 static ssize_t uio_read(struct file *filep, char __user *buf, 506 size_t count, loff_t *ppos) 507 { 508 struct uio_listener *listener = filep->private_data; 509 struct uio_device *idev = listener->dev; 510 DECLARE_WAITQUEUE(wait, current); 511 ssize_t retval; 512 s32 event_count; 513 514 if (!idev->info->irq) 515 return -EIO; 516 517 if (count != sizeof(s32)) 518 return -EINVAL; 519 520 add_wait_queue(&idev->wait, &wait); 521 522 do { 523 set_current_state(TASK_INTERRUPTIBLE); 524 525 event_count = atomic_read(&idev->event); 526 if (event_count != listener->event_count) { 527 __set_current_state(TASK_RUNNING); 528 if (copy_to_user(buf, &event_count, count)) 529 retval = -EFAULT; 530 else { 531 listener->event_count = event_count; 532 retval = count; 533 } 534 break; 535 } 536 537 if (filep->f_flags & O_NONBLOCK) { 538 retval = -EAGAIN; 539 break; 540 } 541 542 if (signal_pending(current)) { 543 retval = -ERESTARTSYS; 544 break; 545 } 546 schedule(); 547 } while (1); 548 549 __set_current_state(TASK_RUNNING); 550 remove_wait_queue(&idev->wait, &wait); 551 552 return retval; 553 } 554 555 static ssize_t uio_write(struct file *filep, const char __user *buf, 556 size_t count, loff_t *ppos) 557 { 558 struct uio_listener *listener = filep->private_data; 559 struct uio_device *idev = listener->dev; 560 ssize_t retval; 561 s32 irq_on; 562 563 if (!idev->info->irq) 564 return -EIO; 565 566 if (count != sizeof(s32)) 567 return -EINVAL; 568 569 if (!idev->info->irqcontrol) 570 return -ENOSYS; 571 572 if (copy_from_user(&irq_on, buf, count)) 573 return -EFAULT; 574 575 retval = idev->info->irqcontrol(idev->info, irq_on); 576 577 return retval ? retval : sizeof(s32); 578 } 579 580 static int uio_find_mem_index(struct vm_area_struct *vma) 581 { 582 struct uio_device *idev = vma->vm_private_data; 583 584 if (vma->vm_pgoff < MAX_UIO_MAPS) { 585 if (idev->info->mem[vma->vm_pgoff].size == 0) 586 return -1; 587 return (int)vma->vm_pgoff; 588 } 589 return -1; 590 } 591 592 static int uio_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf) 593 { 594 struct uio_device *idev = vma->vm_private_data; 595 struct page *page; 596 unsigned long offset; 597 void *addr; 598 599 int mi = uio_find_mem_index(vma); 600 if (mi < 0) 601 return VM_FAULT_SIGBUS; 602 603 /* 604 * We need to subtract mi because userspace uses offset = N*PAGE_SIZE 605 * to use mem[N]. 606 */ 607 offset = (vmf->pgoff - mi) << PAGE_SHIFT; 608 609 addr = (void *)(unsigned long)idev->info->mem[mi].addr + offset; 610 if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL) 611 page = virt_to_page(addr); 612 else 613 page = vmalloc_to_page(addr); 614 get_page(page); 615 vmf->page = page; 616 return 0; 617 } 618 619 static const struct vm_operations_struct uio_logical_vm_ops = { 620 .fault = uio_vma_fault, 621 }; 622 623 static int uio_mmap_logical(struct vm_area_struct *vma) 624 { 625 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP; 626 vma->vm_ops = &uio_logical_vm_ops; 627 return 0; 628 } 629 630 static const struct vm_operations_struct uio_physical_vm_ops = { 631 #ifdef CONFIG_HAVE_IOREMAP_PROT 632 .access = generic_access_phys, 633 #endif 634 }; 635 636 static int uio_mmap_physical(struct vm_area_struct *vma) 637 { 638 struct uio_device *idev = vma->vm_private_data; 639 int mi = uio_find_mem_index(vma); 640 struct uio_mem *mem; 641 if (mi < 0) 642 return -EINVAL; 643 mem = idev->info->mem + mi; 644 645 if (mem->addr & ~PAGE_MASK) 646 return -ENODEV; 647 if (vma->vm_end - vma->vm_start > mem->size) 648 return -EINVAL; 649 650 vma->vm_ops = &uio_physical_vm_ops; 651 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); 652 653 /* 654 * We cannot use the vm_iomap_memory() helper here, 655 * because vma->vm_pgoff is the map index we looked 656 * up above in uio_find_mem_index(), rather than an 657 * actual page offset into the mmap. 658 * 659 * So we just do the physical mmap without a page 660 * offset. 661 */ 662 return remap_pfn_range(vma, 663 vma->vm_start, 664 mem->addr >> PAGE_SHIFT, 665 vma->vm_end - vma->vm_start, 666 vma->vm_page_prot); 667 } 668 669 static int uio_mmap(struct file *filep, struct vm_area_struct *vma) 670 { 671 struct uio_listener *listener = filep->private_data; 672 struct uio_device *idev = listener->dev; 673 int mi; 674 unsigned long requested_pages, actual_pages; 675 int ret = 0; 676 677 if (vma->vm_end < vma->vm_start) 678 return -EINVAL; 679 680 vma->vm_private_data = idev; 681 682 mi = uio_find_mem_index(vma); 683 if (mi < 0) 684 return -EINVAL; 685 686 requested_pages = vma_pages(vma); 687 actual_pages = ((idev->info->mem[mi].addr & ~PAGE_MASK) 688 + idev->info->mem[mi].size + PAGE_SIZE -1) >> PAGE_SHIFT; 689 if (requested_pages > actual_pages) 690 return -EINVAL; 691 692 if (idev->info->mmap) { 693 ret = idev->info->mmap(idev->info, vma); 694 return ret; 695 } 696 697 switch (idev->info->mem[mi].memtype) { 698 case UIO_MEM_PHYS: 699 return uio_mmap_physical(vma); 700 case UIO_MEM_LOGICAL: 701 case UIO_MEM_VIRTUAL: 702 return uio_mmap_logical(vma); 703 default: 704 return -EINVAL; 705 } 706 } 707 708 static const struct file_operations uio_fops = { 709 .owner = THIS_MODULE, 710 .open = uio_open, 711 .release = uio_release, 712 .read = uio_read, 713 .write = uio_write, 714 .mmap = uio_mmap, 715 .poll = uio_poll, 716 .fasync = uio_fasync, 717 .llseek = noop_llseek, 718 }; 719 720 static int uio_major_init(void) 721 { 722 static const char name[] = "uio"; 723 struct cdev *cdev = NULL; 724 dev_t uio_dev = 0; 725 int result; 726 727 result = alloc_chrdev_region(&uio_dev, 0, UIO_MAX_DEVICES, name); 728 if (result) 729 goto out; 730 731 result = -ENOMEM; 732 cdev = cdev_alloc(); 733 if (!cdev) 734 goto out_unregister; 735 736 cdev->owner = THIS_MODULE; 737 cdev->ops = &uio_fops; 738 kobject_set_name(&cdev->kobj, "%s", name); 739 740 result = cdev_add(cdev, uio_dev, UIO_MAX_DEVICES); 741 if (result) 742 goto out_put; 743 744 uio_major = MAJOR(uio_dev); 745 uio_cdev = cdev; 746 return 0; 747 out_put: 748 kobject_put(&cdev->kobj); 749 out_unregister: 750 unregister_chrdev_region(uio_dev, UIO_MAX_DEVICES); 751 out: 752 return result; 753 } 754 755 static void uio_major_cleanup(void) 756 { 757 unregister_chrdev_region(MKDEV(uio_major, 0), UIO_MAX_DEVICES); 758 cdev_del(uio_cdev); 759 } 760 761 static int init_uio_class(void) 762 { 763 int ret; 764 765 /* This is the first time in here, set everything up properly */ 766 ret = uio_major_init(); 767 if (ret) 768 goto exit; 769 770 ret = class_register(&uio_class); 771 if (ret) { 772 printk(KERN_ERR "class_register failed for uio\n"); 773 goto err_class_register; 774 } 775 return 0; 776 777 err_class_register: 778 uio_major_cleanup(); 779 exit: 780 return ret; 781 } 782 783 static void release_uio_class(void) 784 { 785 class_unregister(&uio_class); 786 uio_major_cleanup(); 787 } 788 789 /** 790 * uio_register_device - register a new userspace IO device 791 * @owner: module that creates the new device 792 * @parent: parent device 793 * @info: UIO device capabilities 794 * 795 * returns zero on success or a negative error code. 796 */ 797 int __uio_register_device(struct module *owner, 798 struct device *parent, 799 struct uio_info *info) 800 { 801 struct uio_device *idev; 802 int ret = 0; 803 804 if (!parent || !info || !info->name || !info->version) 805 return -EINVAL; 806 807 info->uio_dev = NULL; 808 809 idev = devm_kzalloc(parent, sizeof(*idev), GFP_KERNEL); 810 if (!idev) { 811 return -ENOMEM; 812 } 813 814 idev->owner = owner; 815 idev->info = info; 816 init_waitqueue_head(&idev->wait); 817 atomic_set(&idev->event, 0); 818 819 ret = uio_get_minor(idev); 820 if (ret) 821 return ret; 822 823 idev->dev = device_create(&uio_class, parent, 824 MKDEV(uio_major, idev->minor), idev, 825 "uio%d", idev->minor); 826 if (IS_ERR(idev->dev)) { 827 printk(KERN_ERR "UIO: device register failed\n"); 828 ret = PTR_ERR(idev->dev); 829 goto err_device_create; 830 } 831 832 ret = uio_dev_add_attributes(idev); 833 if (ret) 834 goto err_uio_dev_add_attributes; 835 836 info->uio_dev = idev; 837 838 if (info->irq && (info->irq != UIO_IRQ_CUSTOM)) { 839 /* 840 * Note that we deliberately don't use devm_request_irq 841 * here. The parent module can unregister the UIO device 842 * and call pci_disable_msi, which requires that this 843 * irq has been freed. However, the device may have open 844 * FDs at the time of unregister and therefore may not be 845 * freed until they are released. 846 */ 847 ret = request_irq(info->irq, uio_interrupt, 848 info->irq_flags, info->name, idev); 849 if (ret) 850 goto err_request_irq; 851 } 852 853 return 0; 854 855 err_request_irq: 856 uio_dev_del_attributes(idev); 857 err_uio_dev_add_attributes: 858 device_destroy(&uio_class, MKDEV(uio_major, idev->minor)); 859 err_device_create: 860 uio_free_minor(idev); 861 return ret; 862 } 863 EXPORT_SYMBOL_GPL(__uio_register_device); 864 865 /** 866 * uio_unregister_device - unregister a industrial IO device 867 * @info: UIO device capabilities 868 * 869 */ 870 void uio_unregister_device(struct uio_info *info) 871 { 872 struct uio_device *idev; 873 874 if (!info || !info->uio_dev) 875 return; 876 877 idev = info->uio_dev; 878 879 uio_free_minor(idev); 880 881 uio_dev_del_attributes(idev); 882 883 if (info->irq && info->irq != UIO_IRQ_CUSTOM) 884 free_irq(info->irq, idev); 885 886 device_destroy(&uio_class, MKDEV(uio_major, idev->minor)); 887 888 return; 889 } 890 EXPORT_SYMBOL_GPL(uio_unregister_device); 891 892 static int __init uio_init(void) 893 { 894 return init_uio_class(); 895 } 896 897 static void __exit uio_exit(void) 898 { 899 release_uio_class(); 900 idr_destroy(&uio_idr); 901 } 902 903 module_init(uio_init) 904 module_exit(uio_exit) 905 MODULE_LICENSE("GPL v2"); 906