uio.c revision 27a90700a4275c5178b883b65927affdafa5185c
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 int vma_count; 39 struct uio_info *info; 40 struct kobject *map_dir; 41 struct kobject *portio_dir; 42}; 43 44static int uio_major; 45static struct cdev *uio_cdev; 46static DEFINE_IDR(uio_idr); 47static const struct file_operations uio_fops; 48 49/* Protect idr accesses */ 50static DEFINE_MUTEX(minor_lock); 51 52/* 53 * attributes 54 */ 55 56struct uio_map { 57 struct kobject kobj; 58 struct uio_mem *mem; 59}; 60#define to_map(map) container_of(map, struct uio_map, kobj) 61 62static ssize_t map_name_show(struct uio_mem *mem, char *buf) 63{ 64 if (unlikely(!mem->name)) 65 mem->name = ""; 66 67 return sprintf(buf, "%s\n", mem->name); 68} 69 70static ssize_t map_addr_show(struct uio_mem *mem, char *buf) 71{ 72 return sprintf(buf, "0x%llx\n", (unsigned long long)mem->addr); 73} 74 75static ssize_t map_size_show(struct uio_mem *mem, char *buf) 76{ 77 return sprintf(buf, "0x%lx\n", mem->size); 78} 79 80static ssize_t map_offset_show(struct uio_mem *mem, char *buf) 81{ 82 return sprintf(buf, "0x%llx\n", (unsigned long long)mem->addr & ~PAGE_MASK); 83} 84 85struct map_sysfs_entry { 86 struct attribute attr; 87 ssize_t (*show)(struct uio_mem *, char *); 88 ssize_t (*store)(struct uio_mem *, const char *, size_t); 89}; 90 91static struct map_sysfs_entry name_attribute = 92 __ATTR(name, S_IRUGO, map_name_show, NULL); 93static struct map_sysfs_entry addr_attribute = 94 __ATTR(addr, S_IRUGO, map_addr_show, NULL); 95static struct map_sysfs_entry size_attribute = 96 __ATTR(size, S_IRUGO, map_size_show, NULL); 97static struct map_sysfs_entry offset_attribute = 98 __ATTR(offset, S_IRUGO, map_offset_show, NULL); 99 100static struct attribute *attrs[] = { 101 &name_attribute.attr, 102 &addr_attribute.attr, 103 &size_attribute.attr, 104 &offset_attribute.attr, 105 NULL, /* need to NULL terminate the list of attributes */ 106}; 107 108static void map_release(struct kobject *kobj) 109{ 110 struct uio_map *map = to_map(kobj); 111 kfree(map); 112} 113 114static ssize_t map_type_show(struct kobject *kobj, struct attribute *attr, 115 char *buf) 116{ 117 struct uio_map *map = to_map(kobj); 118 struct uio_mem *mem = map->mem; 119 struct map_sysfs_entry *entry; 120 121 entry = container_of(attr, struct map_sysfs_entry, attr); 122 123 if (!entry->show) 124 return -EIO; 125 126 return entry->show(mem, buf); 127} 128 129static const struct sysfs_ops map_sysfs_ops = { 130 .show = map_type_show, 131}; 132 133static struct kobj_type map_attr_type = { 134 .release = map_release, 135 .sysfs_ops = &map_sysfs_ops, 136 .default_attrs = attrs, 137}; 138 139struct uio_portio { 140 struct kobject kobj; 141 struct uio_port *port; 142}; 143#define to_portio(portio) container_of(portio, struct uio_portio, kobj) 144 145static ssize_t portio_name_show(struct uio_port *port, char *buf) 146{ 147 if (unlikely(!port->name)) 148 port->name = ""; 149 150 return sprintf(buf, "%s\n", port->name); 151} 152 153static ssize_t portio_start_show(struct uio_port *port, char *buf) 154{ 155 return sprintf(buf, "0x%lx\n", port->start); 156} 157 158static ssize_t portio_size_show(struct uio_port *port, char *buf) 159{ 160 return sprintf(buf, "0x%lx\n", port->size); 161} 162 163static ssize_t portio_porttype_show(struct uio_port *port, char *buf) 164{ 165 const char *porttypes[] = {"none", "x86", "gpio", "other"}; 166 167 if ((port->porttype < 0) || (port->porttype > UIO_PORT_OTHER)) 168 return -EINVAL; 169 170 return sprintf(buf, "port_%s\n", porttypes[port->porttype]); 171} 172 173struct portio_sysfs_entry { 174 struct attribute attr; 175 ssize_t (*show)(struct uio_port *, char *); 176 ssize_t (*store)(struct uio_port *, const char *, size_t); 177}; 178 179static struct portio_sysfs_entry portio_name_attribute = 180 __ATTR(name, S_IRUGO, portio_name_show, NULL); 181static struct portio_sysfs_entry portio_start_attribute = 182 __ATTR(start, S_IRUGO, portio_start_show, NULL); 183static struct portio_sysfs_entry portio_size_attribute = 184 __ATTR(size, S_IRUGO, portio_size_show, NULL); 185static struct portio_sysfs_entry portio_porttype_attribute = 186 __ATTR(porttype, S_IRUGO, portio_porttype_show, NULL); 187 188static struct attribute *portio_attrs[] = { 189 &portio_name_attribute.attr, 190 &portio_start_attribute.attr, 191 &portio_size_attribute.attr, 192 &portio_porttype_attribute.attr, 193 NULL, 194}; 195 196static void portio_release(struct kobject *kobj) 197{ 198 struct uio_portio *portio = to_portio(kobj); 199 kfree(portio); 200} 201 202static ssize_t portio_type_show(struct kobject *kobj, struct attribute *attr, 203 char *buf) 204{ 205 struct uio_portio *portio = to_portio(kobj); 206 struct uio_port *port = portio->port; 207 struct portio_sysfs_entry *entry; 208 209 entry = container_of(attr, struct portio_sysfs_entry, attr); 210 211 if (!entry->show) 212 return -EIO; 213 214 return entry->show(port, buf); 215} 216 217static const struct sysfs_ops portio_sysfs_ops = { 218 .show = portio_type_show, 219}; 220 221static struct kobj_type portio_attr_type = { 222 .release = portio_release, 223 .sysfs_ops = &portio_sysfs_ops, 224 .default_attrs = portio_attrs, 225}; 226 227static ssize_t show_name(struct device *dev, 228 struct device_attribute *attr, char *buf) 229{ 230 struct uio_device *idev = dev_get_drvdata(dev); 231 return sprintf(buf, "%s\n", idev->info->name); 232} 233 234static ssize_t show_version(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} 240 241static ssize_t show_event(struct device *dev, 242 struct device_attribute *attr, char *buf) 243{ 244 struct uio_device *idev = dev_get_drvdata(dev); 245 return sprintf(buf, "%u\n", (unsigned int)atomic_read(&idev->event)); 246} 247 248static struct device_attribute uio_class_attributes[] = { 249 __ATTR(name, S_IRUGO, show_name, NULL), 250 __ATTR(version, S_IRUGO, show_version, NULL), 251 __ATTR(event, S_IRUGO, show_event, NULL), 252 {} 253}; 254 255/* UIO class infrastructure */ 256static struct class uio_class = { 257 .name = "uio", 258 .dev_attrs = uio_class_attributes, 259}; 260 261/* 262 * device functions 263 */ 264static int uio_dev_add_attributes(struct uio_device *idev) 265{ 266 int ret; 267 int mi, pi; 268 int map_found = 0; 269 int portio_found = 0; 270 struct uio_mem *mem; 271 struct uio_map *map; 272 struct uio_port *port; 273 struct uio_portio *portio; 274 275 for (mi = 0; mi < MAX_UIO_MAPS; mi++) { 276 mem = &idev->info->mem[mi]; 277 if (mem->size == 0) 278 break; 279 if (!map_found) { 280 map_found = 1; 281 idev->map_dir = kobject_create_and_add("maps", 282 &idev->dev->kobj); 283 if (!idev->map_dir) 284 goto err_map; 285 } 286 map = kzalloc(sizeof(*map), GFP_KERNEL); 287 if (!map) 288 goto err_map; 289 kobject_init(&map->kobj, &map_attr_type); 290 map->mem = mem; 291 mem->map = map; 292 ret = kobject_add(&map->kobj, idev->map_dir, "map%d", mi); 293 if (ret) 294 goto err_map; 295 ret = kobject_uevent(&map->kobj, KOBJ_ADD); 296 if (ret) 297 goto err_map; 298 } 299 300 for (pi = 0; pi < MAX_UIO_PORT_REGIONS; pi++) { 301 port = &idev->info->port[pi]; 302 if (port->size == 0) 303 break; 304 if (!portio_found) { 305 portio_found = 1; 306 idev->portio_dir = kobject_create_and_add("portio", 307 &idev->dev->kobj); 308 if (!idev->portio_dir) 309 goto err_portio; 310 } 311 portio = kzalloc(sizeof(*portio), GFP_KERNEL); 312 if (!portio) 313 goto err_portio; 314 kobject_init(&portio->kobj, &portio_attr_type); 315 portio->port = port; 316 port->portio = portio; 317 ret = kobject_add(&portio->kobj, idev->portio_dir, 318 "port%d", pi); 319 if (ret) 320 goto err_portio; 321 ret = kobject_uevent(&portio->kobj, KOBJ_ADD); 322 if (ret) 323 goto err_portio; 324 } 325 326 return 0; 327 328err_portio: 329 for (pi--; pi >= 0; pi--) { 330 port = &idev->info->port[pi]; 331 portio = port->portio; 332 kobject_put(&portio->kobj); 333 } 334 kobject_put(idev->portio_dir); 335err_map: 336 for (mi--; mi>=0; mi--) { 337 mem = &idev->info->mem[mi]; 338 map = mem->map; 339 kobject_put(&map->kobj); 340 } 341 kobject_put(idev->map_dir); 342 dev_err(idev->dev, "error creating sysfs files (%d)\n", ret); 343 return ret; 344} 345 346static void uio_dev_del_attributes(struct uio_device *idev) 347{ 348 int i; 349 struct uio_mem *mem; 350 struct uio_port *port; 351 352 for (i = 0; i < MAX_UIO_MAPS; i++) { 353 mem = &idev->info->mem[i]; 354 if (mem->size == 0) 355 break; 356 kobject_put(&mem->map->kobj); 357 } 358 kobject_put(idev->map_dir); 359 360 for (i = 0; i < MAX_UIO_PORT_REGIONS; i++) { 361 port = &idev->info->port[i]; 362 if (port->size == 0) 363 break; 364 kobject_put(&port->portio->kobj); 365 } 366 kobject_put(idev->portio_dir); 367} 368 369static int uio_get_minor(struct uio_device *idev) 370{ 371 int retval = -ENOMEM; 372 int id; 373 374 mutex_lock(&minor_lock); 375 if (idr_pre_get(&uio_idr, GFP_KERNEL) == 0) 376 goto exit; 377 378 retval = idr_get_new(&uio_idr, idev, &id); 379 if (retval < 0) { 380 if (retval == -EAGAIN) 381 retval = -ENOMEM; 382 goto exit; 383 } 384 if (id < UIO_MAX_DEVICES) { 385 idev->minor = id; 386 } else { 387 dev_err(idev->dev, "too many uio devices\n"); 388 retval = -EINVAL; 389 idr_remove(&uio_idr, id); 390 } 391exit: 392 mutex_unlock(&minor_lock); 393 return retval; 394} 395 396static void uio_free_minor(struct uio_device *idev) 397{ 398 mutex_lock(&minor_lock); 399 idr_remove(&uio_idr, idev->minor); 400 mutex_unlock(&minor_lock); 401} 402 403/** 404 * uio_event_notify - trigger an interrupt event 405 * @info: UIO device capabilities 406 */ 407void uio_event_notify(struct uio_info *info) 408{ 409 struct uio_device *idev = info->uio_dev; 410 411 atomic_inc(&idev->event); 412 wake_up_interruptible(&idev->wait); 413 kill_fasync(&idev->async_queue, SIGIO, POLL_IN); 414} 415EXPORT_SYMBOL_GPL(uio_event_notify); 416 417/** 418 * uio_interrupt - hardware interrupt handler 419 * @irq: IRQ number, can be UIO_IRQ_CYCLIC for cyclic timer 420 * @dev_id: Pointer to the devices uio_device structure 421 */ 422static irqreturn_t uio_interrupt(int irq, void *dev_id) 423{ 424 struct uio_device *idev = (struct uio_device *)dev_id; 425 irqreturn_t ret = idev->info->handler(irq, idev->info); 426 427 if (ret == IRQ_HANDLED) 428 uio_event_notify(idev->info); 429 430 return ret; 431} 432 433struct uio_listener { 434 struct uio_device *dev; 435 s32 event_count; 436}; 437 438static int uio_open(struct inode *inode, struct file *filep) 439{ 440 struct uio_device *idev; 441 struct uio_listener *listener; 442 int ret = 0; 443 444 mutex_lock(&minor_lock); 445 idev = idr_find(&uio_idr, iminor(inode)); 446 mutex_unlock(&minor_lock); 447 if (!idev) { 448 ret = -ENODEV; 449 goto out; 450 } 451 452 if (!try_module_get(idev->owner)) { 453 ret = -ENODEV; 454 goto out; 455 } 456 457 listener = kmalloc(sizeof(*listener), GFP_KERNEL); 458 if (!listener) { 459 ret = -ENOMEM; 460 goto err_alloc_listener; 461 } 462 463 listener->dev = idev; 464 listener->event_count = atomic_read(&idev->event); 465 filep->private_data = listener; 466 467 if (idev->info->open) { 468 ret = idev->info->open(idev->info, inode); 469 if (ret) 470 goto err_infoopen; 471 } 472 return 0; 473 474err_infoopen: 475 kfree(listener); 476 477err_alloc_listener: 478 module_put(idev->owner); 479 480out: 481 return ret; 482} 483 484static int uio_fasync(int fd, struct file *filep, int on) 485{ 486 struct uio_listener *listener = filep->private_data; 487 struct uio_device *idev = listener->dev; 488 489 return fasync_helper(fd, filep, on, &idev->async_queue); 490} 491 492static int uio_release(struct inode *inode, struct file *filep) 493{ 494 int ret = 0; 495 struct uio_listener *listener = filep->private_data; 496 struct uio_device *idev = listener->dev; 497 498 if (idev->info->release) 499 ret = idev->info->release(idev->info, inode); 500 501 module_put(idev->owner); 502 kfree(listener); 503 return ret; 504} 505 506static unsigned int uio_poll(struct file *filep, poll_table *wait) 507{ 508 struct uio_listener *listener = filep->private_data; 509 struct uio_device *idev = listener->dev; 510 511 if (!idev->info->irq) 512 return -EIO; 513 514 poll_wait(filep, &idev->wait, wait); 515 if (listener->event_count != atomic_read(&idev->event)) 516 return POLLIN | POLLRDNORM; 517 return 0; 518} 519 520static ssize_t uio_read(struct file *filep, char __user *buf, 521 size_t count, loff_t *ppos) 522{ 523 struct uio_listener *listener = filep->private_data; 524 struct uio_device *idev = listener->dev; 525 DECLARE_WAITQUEUE(wait, current); 526 ssize_t retval; 527 s32 event_count; 528 529 if (!idev->info->irq) 530 return -EIO; 531 532 if (count != sizeof(s32)) 533 return -EINVAL; 534 535 add_wait_queue(&idev->wait, &wait); 536 537 do { 538 set_current_state(TASK_INTERRUPTIBLE); 539 540 event_count = atomic_read(&idev->event); 541 if (event_count != listener->event_count) { 542 if (copy_to_user(buf, &event_count, count)) 543 retval = -EFAULT; 544 else { 545 listener->event_count = event_count; 546 retval = count; 547 } 548 break; 549 } 550 551 if (filep->f_flags & O_NONBLOCK) { 552 retval = -EAGAIN; 553 break; 554 } 555 556 if (signal_pending(current)) { 557 retval = -ERESTARTSYS; 558 break; 559 } 560 schedule(); 561 } while (1); 562 563 __set_current_state(TASK_RUNNING); 564 remove_wait_queue(&idev->wait, &wait); 565 566 return retval; 567} 568 569static ssize_t uio_write(struct file *filep, const char __user *buf, 570 size_t count, loff_t *ppos) 571{ 572 struct uio_listener *listener = filep->private_data; 573 struct uio_device *idev = listener->dev; 574 ssize_t retval; 575 s32 irq_on; 576 577 if (!idev->info->irq) 578 return -EIO; 579 580 if (count != sizeof(s32)) 581 return -EINVAL; 582 583 if (!idev->info->irqcontrol) 584 return -ENOSYS; 585 586 if (copy_from_user(&irq_on, buf, count)) 587 return -EFAULT; 588 589 retval = idev->info->irqcontrol(idev->info, irq_on); 590 591 return retval ? retval : sizeof(s32); 592} 593 594static int uio_find_mem_index(struct vm_area_struct *vma) 595{ 596 struct uio_device *idev = vma->vm_private_data; 597 598 if (vma->vm_pgoff < MAX_UIO_MAPS) { 599 if (idev->info->mem[vma->vm_pgoff].size == 0) 600 return -1; 601 return (int)vma->vm_pgoff; 602 } 603 return -1; 604} 605 606static void uio_vma_open(struct vm_area_struct *vma) 607{ 608 struct uio_device *idev = vma->vm_private_data; 609 idev->vma_count++; 610} 611 612static void uio_vma_close(struct vm_area_struct *vma) 613{ 614 struct uio_device *idev = vma->vm_private_data; 615 idev->vma_count--; 616} 617 618static int uio_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf) 619{ 620 struct uio_device *idev = vma->vm_private_data; 621 struct page *page; 622 unsigned long offset; 623 624 int mi = uio_find_mem_index(vma); 625 if (mi < 0) 626 return VM_FAULT_SIGBUS; 627 628 /* 629 * We need to subtract mi because userspace uses offset = N*PAGE_SIZE 630 * to use mem[N]. 631 */ 632 offset = (vmf->pgoff - mi) << PAGE_SHIFT; 633 634 if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL) 635 page = virt_to_page(idev->info->mem[mi].addr + offset); 636 else 637 page = vmalloc_to_page((void *)(unsigned long)idev->info->mem[mi].addr + offset); 638 get_page(page); 639 vmf->page = page; 640 return 0; 641} 642 643static const struct vm_operations_struct uio_vm_ops = { 644 .open = uio_vma_open, 645 .close = uio_vma_close, 646 .fault = uio_vma_fault, 647}; 648 649static int uio_mmap_physical(struct vm_area_struct *vma) 650{ 651 struct uio_device *idev = vma->vm_private_data; 652 int mi = uio_find_mem_index(vma); 653 if (mi < 0) 654 return -EINVAL; 655 656 vma->vm_flags |= VM_IO | VM_RESERVED; 657 658 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); 659 660 return remap_pfn_range(vma, 661 vma->vm_start, 662 idev->info->mem[mi].addr >> PAGE_SHIFT, 663 vma->vm_end - vma->vm_start, 664 vma->vm_page_prot); 665} 666 667static int uio_mmap_logical(struct vm_area_struct *vma) 668{ 669 vma->vm_flags |= VM_RESERVED; 670 vma->vm_ops = &uio_vm_ops; 671 uio_vma_open(vma); 672 return 0; 673} 674 675static int uio_mmap(struct file *filep, struct vm_area_struct *vma) 676{ 677 struct uio_listener *listener = filep->private_data; 678 struct uio_device *idev = listener->dev; 679 int mi; 680 unsigned long requested_pages, actual_pages; 681 int ret = 0; 682 683 if (vma->vm_end < vma->vm_start) 684 return -EINVAL; 685 686 vma->vm_private_data = idev; 687 688 mi = uio_find_mem_index(vma); 689 if (mi < 0) 690 return -EINVAL; 691 692 requested_pages = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; 693 actual_pages = ((idev->info->mem[mi].addr & ~PAGE_MASK) 694 + idev->info->mem[mi].size + PAGE_SIZE -1) >> PAGE_SHIFT; 695 if (requested_pages > actual_pages) 696 return -EINVAL; 697 698 if (idev->info->mmap) { 699 ret = idev->info->mmap(idev->info, vma); 700 return ret; 701 } 702 703 switch (idev->info->mem[mi].memtype) { 704 case UIO_MEM_PHYS: 705 return uio_mmap_physical(vma); 706 case UIO_MEM_LOGICAL: 707 case UIO_MEM_VIRTUAL: 708 return uio_mmap_logical(vma); 709 default: 710 return -EINVAL; 711 } 712} 713 714static const struct file_operations uio_fops = { 715 .owner = THIS_MODULE, 716 .open = uio_open, 717 .release = uio_release, 718 .read = uio_read, 719 .write = uio_write, 720 .mmap = uio_mmap, 721 .poll = uio_poll, 722 .fasync = uio_fasync, 723 .llseek = noop_llseek, 724}; 725 726static int uio_major_init(void) 727{ 728 static const char name[] = "uio"; 729 struct cdev *cdev = NULL; 730 dev_t uio_dev = 0; 731 int result; 732 733 result = alloc_chrdev_region(&uio_dev, 0, UIO_MAX_DEVICES, name); 734 if (result) 735 goto out; 736 737 result = -ENOMEM; 738 cdev = cdev_alloc(); 739 if (!cdev) 740 goto out_unregister; 741 742 cdev->owner = THIS_MODULE; 743 cdev->ops = &uio_fops; 744 kobject_set_name(&cdev->kobj, "%s", name); 745 746 result = cdev_add(cdev, uio_dev, UIO_MAX_DEVICES); 747 if (result) 748 goto out_put; 749 750 uio_major = MAJOR(uio_dev); 751 uio_cdev = cdev; 752 return 0; 753out_put: 754 kobject_put(&cdev->kobj); 755out_unregister: 756 unregister_chrdev_region(uio_dev, UIO_MAX_DEVICES); 757out: 758 return result; 759} 760 761static void uio_major_cleanup(void) 762{ 763 unregister_chrdev_region(MKDEV(uio_major, 0), UIO_MAX_DEVICES); 764 cdev_del(uio_cdev); 765} 766 767static int init_uio_class(void) 768{ 769 int ret; 770 771 /* This is the first time in here, set everything up properly */ 772 ret = uio_major_init(); 773 if (ret) 774 goto exit; 775 776 ret = class_register(&uio_class); 777 if (ret) { 778 printk(KERN_ERR "class_register failed for uio\n"); 779 goto err_class_register; 780 } 781 return 0; 782 783err_class_register: 784 uio_major_cleanup(); 785exit: 786 return ret; 787} 788 789static void release_uio_class(void) 790{ 791 class_unregister(&uio_class); 792 uio_major_cleanup(); 793} 794 795/** 796 * uio_register_device - register a new userspace IO device 797 * @owner: module that creates the new device 798 * @parent: parent device 799 * @info: UIO device capabilities 800 * 801 * returns zero on success or a negative error code. 802 */ 803int __uio_register_device(struct module *owner, 804 struct device *parent, 805 struct uio_info *info) 806{ 807 struct uio_device *idev; 808 int ret = 0; 809 810 if (!parent || !info || !info->name || !info->version) 811 return -EINVAL; 812 813 info->uio_dev = NULL; 814 815 idev = kzalloc(sizeof(*idev), GFP_KERNEL); 816 if (!idev) { 817 ret = -ENOMEM; 818 goto err_kzalloc; 819 } 820 821 idev->owner = owner; 822 idev->info = info; 823 init_waitqueue_head(&idev->wait); 824 atomic_set(&idev->event, 0); 825 826 ret = uio_get_minor(idev); 827 if (ret) 828 goto err_get_minor; 829 830 idev->dev = device_create(&uio_class, parent, 831 MKDEV(uio_major, idev->minor), idev, 832 "uio%d", idev->minor); 833 if (IS_ERR(idev->dev)) { 834 printk(KERN_ERR "UIO: device register failed\n"); 835 ret = PTR_ERR(idev->dev); 836 goto err_device_create; 837 } 838 839 ret = uio_dev_add_attributes(idev); 840 if (ret) 841 goto err_uio_dev_add_attributes; 842 843 info->uio_dev = idev; 844 845 if (info->irq && (info->irq != UIO_IRQ_CUSTOM)) { 846 ret = request_irq(info->irq, uio_interrupt, 847 info->irq_flags, info->name, idev); 848 if (ret) 849 goto err_request_irq; 850 } 851 852 return 0; 853 854err_request_irq: 855 uio_dev_del_attributes(idev); 856err_uio_dev_add_attributes: 857 device_destroy(&uio_class, MKDEV(uio_major, idev->minor)); 858err_device_create: 859 uio_free_minor(idev); 860err_get_minor: 861 kfree(idev); 862err_kzalloc: 863 return ret; 864} 865EXPORT_SYMBOL_GPL(__uio_register_device); 866 867/** 868 * uio_unregister_device - unregister a industrial IO device 869 * @info: UIO device capabilities 870 * 871 */ 872void uio_unregister_device(struct uio_info *info) 873{ 874 struct uio_device *idev; 875 876 if (!info || !info->uio_dev) 877 return; 878 879 idev = info->uio_dev; 880 881 uio_free_minor(idev); 882 883 if (info->irq && (info->irq != UIO_IRQ_CUSTOM)) 884 free_irq(info->irq, idev); 885 886 uio_dev_del_attributes(idev); 887 888 device_destroy(&uio_class, MKDEV(uio_major, idev->minor)); 889 kfree(idev); 890 891 return; 892} 893EXPORT_SYMBOL_GPL(uio_unregister_device); 894 895static int __init uio_init(void) 896{ 897 return init_uio_class(); 898} 899 900static void __exit uio_exit(void) 901{ 902 release_uio_class(); 903} 904 905module_init(uio_init) 906module_exit(uio_exit) 907MODULE_LICENSE("GPL v2"); 908