uio.c revision e6789cd3dfb553077606ccafeb05e0043f072481
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 31struct uio_device { 32 struct module *owner; 33 struct device *dev; 34 int minor; 35 atomic_t event; 36 struct fasync_struct *async_queue; 37 wait_queue_head_t wait; 38 struct uio_info *info; 39 struct kobject *map_dir; 40 struct kobject *portio_dir; 41}; 42 43static int uio_major; 44static struct cdev *uio_cdev; 45static DEFINE_IDR(uio_idr); 46static const struct file_operations uio_fops; 47 48/* Protect idr accesses */ 49static DEFINE_MUTEX(minor_lock); 50 51/* 52 * attributes 53 */ 54 55struct uio_map { 56 struct kobject kobj; 57 struct uio_mem *mem; 58}; 59#define to_map(map) container_of(map, struct uio_map, kobj) 60 61static ssize_t map_name_show(struct uio_mem *mem, char *buf) 62{ 63 if (unlikely(!mem->name)) 64 mem->name = ""; 65 66 return sprintf(buf, "%s\n", mem->name); 67} 68 69static ssize_t map_addr_show(struct uio_mem *mem, char *buf) 70{ 71 return sprintf(buf, "0x%llx\n", (unsigned long long)mem->addr); 72} 73 74static ssize_t map_size_show(struct uio_mem *mem, char *buf) 75{ 76 return sprintf(buf, "0x%lx\n", mem->size); 77} 78 79static ssize_t map_offset_show(struct uio_mem *mem, char *buf) 80{ 81 return sprintf(buf, "0x%llx\n", (unsigned long long)mem->addr & ~PAGE_MASK); 82} 83 84struct map_sysfs_entry { 85 struct attribute attr; 86 ssize_t (*show)(struct uio_mem *, char *); 87 ssize_t (*store)(struct uio_mem *, const char *, size_t); 88}; 89 90static struct map_sysfs_entry name_attribute = 91 __ATTR(name, S_IRUGO, map_name_show, NULL); 92static struct map_sysfs_entry addr_attribute = 93 __ATTR(addr, S_IRUGO, map_addr_show, NULL); 94static struct map_sysfs_entry size_attribute = 95 __ATTR(size, S_IRUGO, map_size_show, NULL); 96static struct map_sysfs_entry offset_attribute = 97 __ATTR(offset, S_IRUGO, map_offset_show, NULL); 98 99static struct attribute *attrs[] = { 100 &name_attribute.attr, 101 &addr_attribute.attr, 102 &size_attribute.attr, 103 &offset_attribute.attr, 104 NULL, /* need to NULL terminate the list of attributes */ 105}; 106 107static void map_release(struct kobject *kobj) 108{ 109 struct uio_map *map = to_map(kobj); 110 kfree(map); 111} 112 113static ssize_t map_type_show(struct kobject *kobj, struct attribute *attr, 114 char *buf) 115{ 116 struct uio_map *map = to_map(kobj); 117 struct uio_mem *mem = map->mem; 118 struct map_sysfs_entry *entry; 119 120 entry = container_of(attr, struct map_sysfs_entry, attr); 121 122 if (!entry->show) 123 return -EIO; 124 125 return entry->show(mem, buf); 126} 127 128static const struct sysfs_ops map_sysfs_ops = { 129 .show = map_type_show, 130}; 131 132static struct kobj_type map_attr_type = { 133 .release = map_release, 134 .sysfs_ops = &map_sysfs_ops, 135 .default_attrs = attrs, 136}; 137 138struct uio_portio { 139 struct kobject kobj; 140 struct uio_port *port; 141}; 142#define to_portio(portio) container_of(portio, struct uio_portio, kobj) 143 144static ssize_t portio_name_show(struct uio_port *port, char *buf) 145{ 146 if (unlikely(!port->name)) 147 port->name = ""; 148 149 return sprintf(buf, "%s\n", port->name); 150} 151 152static ssize_t portio_start_show(struct uio_port *port, char *buf) 153{ 154 return sprintf(buf, "0x%lx\n", port->start); 155} 156 157static ssize_t portio_size_show(struct uio_port *port, char *buf) 158{ 159 return sprintf(buf, "0x%lx\n", port->size); 160} 161 162static ssize_t portio_porttype_show(struct uio_port *port, char *buf) 163{ 164 const char *porttypes[] = {"none", "x86", "gpio", "other"}; 165 166 if ((port->porttype < 0) || (port->porttype > UIO_PORT_OTHER)) 167 return -EINVAL; 168 169 return sprintf(buf, "port_%s\n", porttypes[port->porttype]); 170} 171 172struct portio_sysfs_entry { 173 struct attribute attr; 174 ssize_t (*show)(struct uio_port *, char *); 175 ssize_t (*store)(struct uio_port *, const char *, size_t); 176}; 177 178static struct portio_sysfs_entry portio_name_attribute = 179 __ATTR(name, S_IRUGO, portio_name_show, NULL); 180static struct portio_sysfs_entry portio_start_attribute = 181 __ATTR(start, S_IRUGO, portio_start_show, NULL); 182static struct portio_sysfs_entry portio_size_attribute = 183 __ATTR(size, S_IRUGO, portio_size_show, NULL); 184static struct portio_sysfs_entry portio_porttype_attribute = 185 __ATTR(porttype, S_IRUGO, portio_porttype_show, NULL); 186 187static struct attribute *portio_attrs[] = { 188 &portio_name_attribute.attr, 189 &portio_start_attribute.attr, 190 &portio_size_attribute.attr, 191 &portio_porttype_attribute.attr, 192 NULL, 193}; 194 195static void portio_release(struct kobject *kobj) 196{ 197 struct uio_portio *portio = to_portio(kobj); 198 kfree(portio); 199} 200 201static ssize_t portio_type_show(struct kobject *kobj, struct attribute *attr, 202 char *buf) 203{ 204 struct uio_portio *portio = to_portio(kobj); 205 struct uio_port *port = portio->port; 206 struct portio_sysfs_entry *entry; 207 208 entry = container_of(attr, struct portio_sysfs_entry, attr); 209 210 if (!entry->show) 211 return -EIO; 212 213 return entry->show(port, buf); 214} 215 216static const struct sysfs_ops portio_sysfs_ops = { 217 .show = portio_type_show, 218}; 219 220static struct kobj_type portio_attr_type = { 221 .release = portio_release, 222 .sysfs_ops = &portio_sysfs_ops, 223 .default_attrs = portio_attrs, 224}; 225 226static ssize_t name_show(struct device *dev, 227 struct device_attribute *attr, char *buf) 228{ 229 struct uio_device *idev = dev_get_drvdata(dev); 230 return sprintf(buf, "%s\n", idev->info->name); 231} 232static DEVICE_ATTR_RO(name); 233 234static ssize_t version_show(struct device *dev, 235 struct device_attribute *attr, char *buf) 236{ 237 struct uio_device *idev = dev_get_drvdata(dev); 238 return sprintf(buf, "%s\n", idev->info->version); 239} 240static DEVICE_ATTR_RO(version); 241 242static ssize_t event_show(struct device *dev, 243 struct device_attribute *attr, char *buf) 244{ 245 struct uio_device *idev = dev_get_drvdata(dev); 246 return sprintf(buf, "%u\n", (unsigned int)atomic_read(&idev->event)); 247} 248static DEVICE_ATTR_RO(event); 249 250static struct attribute *uio_attrs[] = { 251 &dev_attr_name.attr, 252 &dev_attr_version.attr, 253 &dev_attr_event.attr, 254 NULL, 255}; 256ATTRIBUTE_GROUPS(uio); 257 258/* UIO class infrastructure */ 259static struct class uio_class = { 260 .name = "uio", 261 .dev_groups = uio_groups, 262}; 263 264/* 265 * device functions 266 */ 267static int uio_dev_add_attributes(struct uio_device *idev) 268{ 269 int ret; 270 int mi, pi; 271 int map_found = 0; 272 int portio_found = 0; 273 struct uio_mem *mem; 274 struct uio_map *map; 275 struct uio_port *port; 276 struct uio_portio *portio; 277 278 for (mi = 0; mi < MAX_UIO_MAPS; mi++) { 279 mem = &idev->info->mem[mi]; 280 if (mem->size == 0) 281 break; 282 if (!map_found) { 283 map_found = 1; 284 idev->map_dir = kobject_create_and_add("maps", 285 &idev->dev->kobj); 286 if (!idev->map_dir) 287 goto err_map; 288 } 289 map = kzalloc(sizeof(*map), GFP_KERNEL); 290 if (!map) 291 goto err_map; 292 kobject_init(&map->kobj, &map_attr_type); 293 map->mem = mem; 294 mem->map = map; 295 ret = kobject_add(&map->kobj, idev->map_dir, "map%d", mi); 296 if (ret) 297 goto err_map; 298 ret = kobject_uevent(&map->kobj, KOBJ_ADD); 299 if (ret) 300 goto err_map; 301 } 302 303 for (pi = 0; pi < MAX_UIO_PORT_REGIONS; pi++) { 304 port = &idev->info->port[pi]; 305 if (port->size == 0) 306 break; 307 if (!portio_found) { 308 portio_found = 1; 309 idev->portio_dir = kobject_create_and_add("portio", 310 &idev->dev->kobj); 311 if (!idev->portio_dir) 312 goto err_portio; 313 } 314 portio = kzalloc(sizeof(*portio), GFP_KERNEL); 315 if (!portio) 316 goto err_portio; 317 kobject_init(&portio->kobj, &portio_attr_type); 318 portio->port = port; 319 port->portio = portio; 320 ret = kobject_add(&portio->kobj, idev->portio_dir, 321 "port%d", pi); 322 if (ret) 323 goto err_portio; 324 ret = kobject_uevent(&portio->kobj, KOBJ_ADD); 325 if (ret) 326 goto err_portio; 327 } 328 329 return 0; 330 331err_portio: 332 for (pi--; pi >= 0; pi--) { 333 port = &idev->info->port[pi]; 334 portio = port->portio; 335 kobject_put(&portio->kobj); 336 } 337 kobject_put(idev->portio_dir); 338err_map: 339 for (mi--; mi>=0; mi--) { 340 mem = &idev->info->mem[mi]; 341 map = mem->map; 342 kobject_put(&map->kobj); 343 } 344 kobject_put(idev->map_dir); 345 dev_err(idev->dev, "error creating sysfs files (%d)\n", ret); 346 return ret; 347} 348 349static void uio_dev_del_attributes(struct uio_device *idev) 350{ 351 int i; 352 struct uio_mem *mem; 353 struct uio_port *port; 354 355 for (i = 0; i < MAX_UIO_MAPS; i++) { 356 mem = &idev->info->mem[i]; 357 if (mem->size == 0) 358 break; 359 kobject_put(&mem->map->kobj); 360 } 361 kobject_put(idev->map_dir); 362 363 for (i = 0; i < MAX_UIO_PORT_REGIONS; i++) { 364 port = &idev->info->port[i]; 365 if (port->size == 0) 366 break; 367 kobject_put(&port->portio->kobj); 368 } 369 kobject_put(idev->portio_dir); 370} 371 372static int uio_get_minor(struct uio_device *idev) 373{ 374 int retval = -ENOMEM; 375 376 mutex_lock(&minor_lock); 377 retval = idr_alloc(&uio_idr, idev, 0, UIO_MAX_DEVICES, GFP_KERNEL); 378 if (retval >= 0) { 379 idev->minor = retval; 380 retval = 0; 381 } else if (retval == -ENOSPC) { 382 dev_err(idev->dev, "too many uio devices\n"); 383 retval = -EINVAL; 384 } 385 mutex_unlock(&minor_lock); 386 return retval; 387} 388 389static void uio_free_minor(struct uio_device *idev) 390{ 391 mutex_lock(&minor_lock); 392 idr_remove(&uio_idr, idev->minor); 393 mutex_unlock(&minor_lock); 394} 395 396/** 397 * uio_event_notify - trigger an interrupt event 398 * @info: UIO device capabilities 399 */ 400void uio_event_notify(struct uio_info *info) 401{ 402 struct uio_device *idev = info->uio_dev; 403 404 atomic_inc(&idev->event); 405 wake_up_interruptible(&idev->wait); 406 kill_fasync(&idev->async_queue, SIGIO, POLL_IN); 407} 408EXPORT_SYMBOL_GPL(uio_event_notify); 409 410/** 411 * uio_interrupt - hardware interrupt handler 412 * @irq: IRQ number, can be UIO_IRQ_CYCLIC for cyclic timer 413 * @dev_id: Pointer to the devices uio_device structure 414 */ 415static irqreturn_t uio_interrupt(int irq, void *dev_id) 416{ 417 struct uio_device *idev = (struct uio_device *)dev_id; 418 irqreturn_t ret = idev->info->handler(irq, idev->info); 419 420 if (ret == IRQ_HANDLED) 421 uio_event_notify(idev->info); 422 423 return ret; 424} 425 426struct uio_listener { 427 struct uio_device *dev; 428 s32 event_count; 429}; 430 431static int uio_open(struct inode *inode, struct file *filep) 432{ 433 struct uio_device *idev; 434 struct uio_listener *listener; 435 int ret = 0; 436 437 mutex_lock(&minor_lock); 438 idev = idr_find(&uio_idr, iminor(inode)); 439 mutex_unlock(&minor_lock); 440 if (!idev) { 441 ret = -ENODEV; 442 goto out; 443 } 444 445 if (!try_module_get(idev->owner)) { 446 ret = -ENODEV; 447 goto out; 448 } 449 450 listener = kmalloc(sizeof(*listener), GFP_KERNEL); 451 if (!listener) { 452 ret = -ENOMEM; 453 goto err_alloc_listener; 454 } 455 456 listener->dev = idev; 457 listener->event_count = atomic_read(&idev->event); 458 filep->private_data = listener; 459 460 if (idev->info->open) { 461 ret = idev->info->open(idev->info, inode); 462 if (ret) 463 goto err_infoopen; 464 } 465 return 0; 466 467err_infoopen: 468 kfree(listener); 469 470err_alloc_listener: 471 module_put(idev->owner); 472 473out: 474 return ret; 475} 476 477static int uio_fasync(int fd, struct file *filep, int on) 478{ 479 struct uio_listener *listener = filep->private_data; 480 struct uio_device *idev = listener->dev; 481 482 return fasync_helper(fd, filep, on, &idev->async_queue); 483} 484 485static int uio_release(struct inode *inode, struct file *filep) 486{ 487 int ret = 0; 488 struct uio_listener *listener = filep->private_data; 489 struct uio_device *idev = listener->dev; 490 491 if (idev->info->release) 492 ret = idev->info->release(idev->info, inode); 493 494 module_put(idev->owner); 495 kfree(listener); 496 return ret; 497} 498 499static unsigned int uio_poll(struct file *filep, poll_table *wait) 500{ 501 struct uio_listener *listener = filep->private_data; 502 struct uio_device *idev = listener->dev; 503 504 if (!idev->info->irq) 505 return -EIO; 506 507 poll_wait(filep, &idev->wait, wait); 508 if (listener->event_count != atomic_read(&idev->event)) 509 return POLLIN | POLLRDNORM; 510 return 0; 511} 512 513static ssize_t uio_read(struct file *filep, char __user *buf, 514 size_t count, loff_t *ppos) 515{ 516 struct uio_listener *listener = filep->private_data; 517 struct uio_device *idev = listener->dev; 518 DECLARE_WAITQUEUE(wait, current); 519 ssize_t retval; 520 s32 event_count; 521 522 if (!idev->info->irq) 523 return -EIO; 524 525 if (count != sizeof(s32)) 526 return -EINVAL; 527 528 add_wait_queue(&idev->wait, &wait); 529 530 do { 531 set_current_state(TASK_INTERRUPTIBLE); 532 533 event_count = atomic_read(&idev->event); 534 if (event_count != listener->event_count) { 535 if (copy_to_user(buf, &event_count, count)) 536 retval = -EFAULT; 537 else { 538 listener->event_count = event_count; 539 retval = count; 540 } 541 break; 542 } 543 544 if (filep->f_flags & O_NONBLOCK) { 545 retval = -EAGAIN; 546 break; 547 } 548 549 if (signal_pending(current)) { 550 retval = -ERESTARTSYS; 551 break; 552 } 553 schedule(); 554 } while (1); 555 556 __set_current_state(TASK_RUNNING); 557 remove_wait_queue(&idev->wait, &wait); 558 559 return retval; 560} 561 562static ssize_t uio_write(struct file *filep, const char __user *buf, 563 size_t count, loff_t *ppos) 564{ 565 struct uio_listener *listener = filep->private_data; 566 struct uio_device *idev = listener->dev; 567 ssize_t retval; 568 s32 irq_on; 569 570 if (!idev->info->irq) 571 return -EIO; 572 573 if (count != sizeof(s32)) 574 return -EINVAL; 575 576 if (!idev->info->irqcontrol) 577 return -ENOSYS; 578 579 if (copy_from_user(&irq_on, buf, count)) 580 return -EFAULT; 581 582 retval = idev->info->irqcontrol(idev->info, irq_on); 583 584 return retval ? retval : sizeof(s32); 585} 586 587static int uio_find_mem_index(struct vm_area_struct *vma) 588{ 589 struct uio_device *idev = vma->vm_private_data; 590 591 if (vma->vm_pgoff < MAX_UIO_MAPS) { 592 if (idev->info->mem[vma->vm_pgoff].size == 0) 593 return -1; 594 return (int)vma->vm_pgoff; 595 } 596 return -1; 597} 598 599static int uio_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf) 600{ 601 struct uio_device *idev = vma->vm_private_data; 602 struct page *page; 603 unsigned long offset; 604 605 int mi = uio_find_mem_index(vma); 606 if (mi < 0) 607 return VM_FAULT_SIGBUS; 608 609 /* 610 * We need to subtract mi because userspace uses offset = N*PAGE_SIZE 611 * to use mem[N]. 612 */ 613 offset = (vmf->pgoff - mi) << PAGE_SHIFT; 614 615 if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL) 616 page = virt_to_page(idev->info->mem[mi].addr + offset); 617 else 618 page = vmalloc_to_page((void *)(unsigned long)idev->info->mem[mi].addr + offset); 619 get_page(page); 620 vmf->page = page; 621 return 0; 622} 623 624static const struct vm_operations_struct uio_logical_vm_ops = { 625 .fault = uio_vma_fault, 626}; 627 628static int uio_mmap_logical(struct vm_area_struct *vma) 629{ 630 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP; 631 vma->vm_ops = &uio_logical_vm_ops; 632 return 0; 633} 634 635static const struct vm_operations_struct uio_physical_vm_ops = { 636#ifdef CONFIG_HAVE_IOREMAP_PROT 637 .access = generic_access_phys, 638#endif 639}; 640 641static int uio_mmap_physical(struct vm_area_struct *vma) 642{ 643 struct uio_device *idev = vma->vm_private_data; 644 int mi = uio_find_mem_index(vma); 645 if (mi < 0) 646 return -EINVAL; 647 648 vma->vm_ops = &uio_physical_vm_ops; 649 650 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); 651 652 return remap_pfn_range(vma, 653 vma->vm_start, 654 idev->info->mem[mi].addr >> PAGE_SHIFT, 655 vma->vm_end - vma->vm_start, 656 vma->vm_page_prot); 657} 658 659static int uio_mmap(struct file *filep, struct vm_area_struct *vma) 660{ 661 struct uio_listener *listener = filep->private_data; 662 struct uio_device *idev = listener->dev; 663 int mi; 664 unsigned long requested_pages, actual_pages; 665 int ret = 0; 666 667 if (vma->vm_end < vma->vm_start) 668 return -EINVAL; 669 670 vma->vm_private_data = idev; 671 672 mi = uio_find_mem_index(vma); 673 if (mi < 0) 674 return -EINVAL; 675 676 requested_pages = vma_pages(vma); 677 actual_pages = ((idev->info->mem[mi].addr & ~PAGE_MASK) 678 + idev->info->mem[mi].size + PAGE_SIZE -1) >> PAGE_SHIFT; 679 if (requested_pages > actual_pages) 680 return -EINVAL; 681 682 if (idev->info->mmap) { 683 ret = idev->info->mmap(idev->info, vma); 684 return ret; 685 } 686 687 switch (idev->info->mem[mi].memtype) { 688 case UIO_MEM_PHYS: 689 return uio_mmap_physical(vma); 690 case UIO_MEM_LOGICAL: 691 case UIO_MEM_VIRTUAL: 692 return uio_mmap_logical(vma); 693 default: 694 return -EINVAL; 695 } 696} 697 698static const struct file_operations uio_fops = { 699 .owner = THIS_MODULE, 700 .open = uio_open, 701 .release = uio_release, 702 .read = uio_read, 703 .write = uio_write, 704 .mmap = uio_mmap, 705 .poll = uio_poll, 706 .fasync = uio_fasync, 707 .llseek = noop_llseek, 708}; 709 710static int uio_major_init(void) 711{ 712 static const char name[] = "uio"; 713 struct cdev *cdev = NULL; 714 dev_t uio_dev = 0; 715 int result; 716 717 result = alloc_chrdev_region(&uio_dev, 0, UIO_MAX_DEVICES, name); 718 if (result) 719 goto out; 720 721 result = -ENOMEM; 722 cdev = cdev_alloc(); 723 if (!cdev) 724 goto out_unregister; 725 726 cdev->owner = THIS_MODULE; 727 cdev->ops = &uio_fops; 728 kobject_set_name(&cdev->kobj, "%s", name); 729 730 result = cdev_add(cdev, uio_dev, UIO_MAX_DEVICES); 731 if (result) 732 goto out_put; 733 734 uio_major = MAJOR(uio_dev); 735 uio_cdev = cdev; 736 return 0; 737out_put: 738 kobject_put(&cdev->kobj); 739out_unregister: 740 unregister_chrdev_region(uio_dev, UIO_MAX_DEVICES); 741out: 742 return result; 743} 744 745static void uio_major_cleanup(void) 746{ 747 unregister_chrdev_region(MKDEV(uio_major, 0), UIO_MAX_DEVICES); 748 cdev_del(uio_cdev); 749} 750 751static int init_uio_class(void) 752{ 753 int ret; 754 755 /* This is the first time in here, set everything up properly */ 756 ret = uio_major_init(); 757 if (ret) 758 goto exit; 759 760 ret = class_register(&uio_class); 761 if (ret) { 762 printk(KERN_ERR "class_register failed for uio\n"); 763 goto err_class_register; 764 } 765 return 0; 766 767err_class_register: 768 uio_major_cleanup(); 769exit: 770 return ret; 771} 772 773static void release_uio_class(void) 774{ 775 class_unregister(&uio_class); 776 uio_major_cleanup(); 777} 778 779/** 780 * uio_register_device - register a new userspace IO device 781 * @owner: module that creates the new device 782 * @parent: parent device 783 * @info: UIO device capabilities 784 * 785 * returns zero on success or a negative error code. 786 */ 787int __uio_register_device(struct module *owner, 788 struct device *parent, 789 struct uio_info *info) 790{ 791 struct uio_device *idev; 792 int ret = 0; 793 794 if (!parent || !info || !info->name || !info->version) 795 return -EINVAL; 796 797 info->uio_dev = NULL; 798 799 idev = devm_kzalloc(parent, sizeof(*idev), GFP_KERNEL); 800 if (!idev) { 801 return -ENOMEM; 802 } 803 804 idev->owner = owner; 805 idev->info = info; 806 init_waitqueue_head(&idev->wait); 807 atomic_set(&idev->event, 0); 808 809 ret = uio_get_minor(idev); 810 if (ret) 811 return ret; 812 813 idev->dev = device_create(&uio_class, parent, 814 MKDEV(uio_major, idev->minor), idev, 815 "uio%d", idev->minor); 816 if (IS_ERR(idev->dev)) { 817 printk(KERN_ERR "UIO: device register failed\n"); 818 ret = PTR_ERR(idev->dev); 819 goto err_device_create; 820 } 821 822 ret = uio_dev_add_attributes(idev); 823 if (ret) 824 goto err_uio_dev_add_attributes; 825 826 info->uio_dev = idev; 827 828 if (info->irq && (info->irq != UIO_IRQ_CUSTOM)) { 829 ret = devm_request_irq(parent, info->irq, uio_interrupt, 830 info->irq_flags, info->name, idev); 831 if (ret) 832 goto err_request_irq; 833 } 834 835 return 0; 836 837err_request_irq: 838 uio_dev_del_attributes(idev); 839err_uio_dev_add_attributes: 840 device_destroy(&uio_class, MKDEV(uio_major, idev->minor)); 841err_device_create: 842 uio_free_minor(idev); 843 return ret; 844} 845EXPORT_SYMBOL_GPL(__uio_register_device); 846 847/** 848 * uio_unregister_device - unregister a industrial IO device 849 * @info: UIO device capabilities 850 * 851 */ 852void uio_unregister_device(struct uio_info *info) 853{ 854 struct uio_device *idev; 855 856 if (!info || !info->uio_dev) 857 return; 858 859 idev = info->uio_dev; 860 861 uio_free_minor(idev); 862 863 uio_dev_del_attributes(idev); 864 865 device_destroy(&uio_class, MKDEV(uio_major, idev->minor)); 866 867 return; 868} 869EXPORT_SYMBOL_GPL(uio_unregister_device); 870 871static int __init uio_init(void) 872{ 873 return init_uio_class(); 874} 875 876static void __exit uio_exit(void) 877{ 878 release_uio_class(); 879} 880 881module_init(uio_init) 882module_exit(uio_exit) 883MODULE_LICENSE("GPL v2"); 884