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 struct 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 44 static int uio_major; 45 static struct cdev *uio_cdev; 46 static DEFINE_IDR(uio_idr); 47 static const struct file_operations uio_fops; 48 49 /* Protect idr accesses */ 50 static DEFINE_MUTEX(minor_lock); 51 52 /* 53 * attributes 54 */ 55 56 struct 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 62 static 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 70 static ssize_t map_addr_show(struct uio_mem *mem, char *buf) 71 { 72 return sprintf(buf, "0x%lx\n", mem->addr); 73 } 74 75 static ssize_t map_size_show(struct uio_mem *mem, char *buf) 76 { 77 return sprintf(buf, "0x%lx\n", mem->size); 78 } 79 80 static ssize_t map_offset_show(struct uio_mem *mem, char *buf) 81 { 82 return sprintf(buf, "0x%lx\n", mem->addr & ~PAGE_MASK); 83 } 84 85 struct 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 91 static struct map_sysfs_entry name_attribute = 92 __ATTR(name, S_IRUGO, map_name_show, NULL); 93 static struct map_sysfs_entry addr_attribute = 94 __ATTR(addr, S_IRUGO, map_addr_show, NULL); 95 static struct map_sysfs_entry size_attribute = 96 __ATTR(size, S_IRUGO, map_size_show, NULL); 97 static struct map_sysfs_entry offset_attribute = 98 __ATTR(offset, S_IRUGO, map_offset_show, NULL); 99 100 static 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 }; 107 108 static void map_release(struct kobject *kobj) 109 { 110 struct uio_map *map = to_map(kobj); 111 kfree(map); 112 } 113 114 static 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 } 128 129 static const struct sysfs_ops map_sysfs_ops = { 130 .show = map_type_show, 131 }; 132 133 static struct kobj_type map_attr_type = { 134 .release = map_release, 135 .sysfs_ops = &map_sysfs_ops, 136 .default_attrs = attrs, 137 }; 138 139 struct uio_portio { 140 struct kobject kobj; 141 struct uio_port *port; 142 }; 143 #define to_portio(portio) container_of(portio, struct uio_portio, kobj) 144 145 static 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 } 152 153 static ssize_t portio_start_show(struct uio_port *port, char *buf) 154 { 155 return sprintf(buf, "0x%lx\n", port->start); 156 } 157 158 static ssize_t portio_size_show(struct uio_port *port, char *buf) 159 { 160 return sprintf(buf, "0x%lx\n", port->size); 161 } 162 163 static 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 } 172 173 struct 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 }; 178 179 static struct portio_sysfs_entry portio_name_attribute = 180 __ATTR(name, S_IRUGO, portio_name_show, NULL); 181 static struct portio_sysfs_entry portio_start_attribute = 182 __ATTR(start, S_IRUGO, portio_start_show, NULL); 183 static struct portio_sysfs_entry portio_size_attribute = 184 __ATTR(size, S_IRUGO, portio_size_show, NULL); 185 static struct portio_sysfs_entry portio_porttype_attribute = 186 __ATTR(porttype, S_IRUGO, portio_porttype_show, NULL); 187 188 static 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 }; 195 196 static void portio_release(struct kobject *kobj) 197 { 198 struct uio_portio *portio = to_portio(kobj); 199 kfree(portio); 200 } 201 202 static 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 } 216 217 static const struct sysfs_ops portio_sysfs_ops = { 218 .show = portio_type_show, 219 }; 220 221 static struct kobj_type portio_attr_type = { 222 .release = portio_release, 223 .sysfs_ops = &portio_sysfs_ops, 224 .default_attrs = portio_attrs, 225 }; 226 227 static 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 } 233 234 static 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 } 240 241 static 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 } 247 248 static 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 */ 256 static struct class uio_class = { 257 .name = "uio", 258 .dev_attrs = uio_class_attributes, 259 }; 260 261 /* 262 * device functions 263 */ 264 static 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; 327 328 err_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); 335 err_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 } 345 346 static 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 } 368 369 static 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 idev->minor = id & MAX_ID_MASK; 385 exit: 386 mutex_unlock(&minor_lock); 387 return retval; 388 } 389 390 static void uio_free_minor(struct uio_device *idev) 391 { 392 mutex_lock(&minor_lock); 393 idr_remove(&uio_idr, idev->minor); 394 mutex_unlock(&minor_lock); 395 } 396 397 /** 398 * uio_event_notify - trigger an interrupt event 399 * @info: UIO device capabilities 400 */ 401 void uio_event_notify(struct uio_info *info) 402 { 403 struct uio_device *idev = info->uio_dev; 404 405 atomic_inc(&idev->event); 406 wake_up_interruptible(&idev->wait); 407 kill_fasync(&idev->async_queue, SIGIO, POLL_IN); 408 } 409 EXPORT_SYMBOL_GPL(uio_event_notify); 410 411 /** 412 * uio_interrupt - hardware interrupt handler 413 * @irq: IRQ number, can be UIO_IRQ_CYCLIC for cyclic timer 414 * @dev_id: Pointer to the devices uio_device structure 415 */ 416 static irqreturn_t uio_interrupt(int irq, void *dev_id) 417 { 418 struct uio_device *idev = (struct uio_device *)dev_id; 419 irqreturn_t ret = idev->info->handler(irq, idev->info); 420 421 if (ret == IRQ_HANDLED) 422 uio_event_notify(idev->info); 423 424 return ret; 425 } 426 427 struct uio_listener { 428 struct uio_device *dev; 429 s32 event_count; 430 }; 431 432 static int uio_open(struct inode *inode, struct file *filep) 433 { 434 struct uio_device *idev; 435 struct uio_listener *listener; 436 int ret = 0; 437 438 mutex_lock(&minor_lock); 439 idev = idr_find(&uio_idr, iminor(inode)); 440 mutex_unlock(&minor_lock); 441 if (!idev) { 442 ret = -ENODEV; 443 goto out; 444 } 445 446 if (!try_module_get(idev->owner)) { 447 ret = -ENODEV; 448 goto out; 449 } 450 451 listener = kmalloc(sizeof(*listener), GFP_KERNEL); 452 if (!listener) { 453 ret = -ENOMEM; 454 goto err_alloc_listener; 455 } 456 457 listener->dev = idev; 458 listener->event_count = atomic_read(&idev->event); 459 filep->private_data = listener; 460 461 if (idev->info->open) { 462 ret = idev->info->open(idev->info, inode); 463 if (ret) 464 goto err_infoopen; 465 } 466 return 0; 467 468 err_infoopen: 469 kfree(listener); 470 471 err_alloc_listener: 472 module_put(idev->owner); 473 474 out: 475 return ret; 476 } 477 478 static int uio_fasync(int fd, struct file *filep, int on) 479 { 480 struct uio_listener *listener = filep->private_data; 481 struct uio_device *idev = listener->dev; 482 483 return fasync_helper(fd, filep, on, &idev->async_queue); 484 } 485 486 static int uio_release(struct inode *inode, struct file *filep) 487 { 488 int ret = 0; 489 struct uio_listener *listener = filep->private_data; 490 struct uio_device *idev = listener->dev; 491 492 if (idev->info->release) 493 ret = idev->info->release(idev->info, inode); 494 495 module_put(idev->owner); 496 kfree(listener); 497 return ret; 498 } 499 500 static unsigned int uio_poll(struct file *filep, poll_table *wait) 501 { 502 struct uio_listener *listener = filep->private_data; 503 struct uio_device *idev = listener->dev; 504 505 if (!idev->info->irq) 506 return -EIO; 507 508 poll_wait(filep, &idev->wait, wait); 509 if (listener->event_count != atomic_read(&idev->event)) 510 return POLLIN | POLLRDNORM; 511 return 0; 512 } 513 514 static ssize_t uio_read(struct file *filep, char __user *buf, 515 size_t count, loff_t *ppos) 516 { 517 struct uio_listener *listener = filep->private_data; 518 struct uio_device *idev = listener->dev; 519 DECLARE_WAITQUEUE(wait, current); 520 ssize_t retval; 521 s32 event_count; 522 523 if (!idev->info->irq) 524 return -EIO; 525 526 if (count != sizeof(s32)) 527 return -EINVAL; 528 529 add_wait_queue(&idev->wait, &wait); 530 531 do { 532 set_current_state(TASK_INTERRUPTIBLE); 533 534 event_count = atomic_read(&idev->event); 535 if (event_count != listener->event_count) { 536 if (copy_to_user(buf, &event_count, count)) 537 retval = -EFAULT; 538 else { 539 listener->event_count = event_count; 540 retval = count; 541 } 542 break; 543 } 544 545 if (filep->f_flags & O_NONBLOCK) { 546 retval = -EAGAIN; 547 break; 548 } 549 550 if (signal_pending(current)) { 551 retval = -ERESTARTSYS; 552 break; 553 } 554 schedule(); 555 } while (1); 556 557 __set_current_state(TASK_RUNNING); 558 remove_wait_queue(&idev->wait, &wait); 559 560 return retval; 561 } 562 563 static ssize_t uio_write(struct file *filep, const char __user *buf, 564 size_t count, loff_t *ppos) 565 { 566 struct uio_listener *listener = filep->private_data; 567 struct uio_device *idev = listener->dev; 568 ssize_t retval; 569 s32 irq_on; 570 571 if (!idev->info->irq) 572 return -EIO; 573 574 if (count != sizeof(s32)) 575 return -EINVAL; 576 577 if (!idev->info->irqcontrol) 578 return -ENOSYS; 579 580 if (copy_from_user(&irq_on, buf, count)) 581 return -EFAULT; 582 583 retval = idev->info->irqcontrol(idev->info, irq_on); 584 585 return retval ? retval : sizeof(s32); 586 } 587 588 static int uio_find_mem_index(struct vm_area_struct *vma) 589 { 590 int mi; 591 struct uio_device *idev = vma->vm_private_data; 592 593 for (mi = 0; mi < MAX_UIO_MAPS; mi++) { 594 if (idev->info->mem[mi].size == 0) 595 return -1; 596 if (vma->vm_pgoff == mi) 597 return mi; 598 } 599 return -1; 600 } 601 602 static void uio_vma_open(struct vm_area_struct *vma) 603 { 604 struct uio_device *idev = vma->vm_private_data; 605 idev->vma_count++; 606 } 607 608 static void uio_vma_close(struct vm_area_struct *vma) 609 { 610 struct uio_device *idev = vma->vm_private_data; 611 idev->vma_count--; 612 } 613 614 static int uio_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf) 615 { 616 struct uio_device *idev = vma->vm_private_data; 617 struct page *page; 618 unsigned long offset; 619 620 int mi = uio_find_mem_index(vma); 621 if (mi < 0) 622 return VM_FAULT_SIGBUS; 623 624 /* 625 * We need to subtract mi because userspace uses offset = N*PAGE_SIZE 626 * to use mem[N]. 627 */ 628 offset = (vmf->pgoff - mi) << PAGE_SHIFT; 629 630 if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL) 631 page = virt_to_page(idev->info->mem[mi].addr + offset); 632 else 633 page = vmalloc_to_page((void *)idev->info->mem[mi].addr 634 + offset); 635 get_page(page); 636 vmf->page = page; 637 return 0; 638 } 639 640 static const struct vm_operations_struct uio_vm_ops = { 641 .open = uio_vma_open, 642 .close = uio_vma_close, 643 .fault = uio_vma_fault, 644 }; 645 646 static int uio_mmap_physical(struct vm_area_struct *vma) 647 { 648 struct uio_device *idev = vma->vm_private_data; 649 int mi = uio_find_mem_index(vma); 650 if (mi < 0) 651 return -EINVAL; 652 653 vma->vm_flags |= VM_IO | VM_RESERVED; 654 655 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); 656 657 return remap_pfn_range(vma, 658 vma->vm_start, 659 idev->info->mem[mi].addr >> PAGE_SHIFT, 660 vma->vm_end - vma->vm_start, 661 vma->vm_page_prot); 662 } 663 664 static int uio_mmap_logical(struct vm_area_struct *vma) 665 { 666 vma->vm_flags |= VM_RESERVED; 667 vma->vm_ops = &uio_vm_ops; 668 uio_vma_open(vma); 669 return 0; 670 } 671 672 static int uio_mmap(struct file *filep, struct vm_area_struct *vma) 673 { 674 struct uio_listener *listener = filep->private_data; 675 struct uio_device *idev = listener->dev; 676 int mi; 677 unsigned long requested_pages, actual_pages; 678 int ret = 0; 679 680 if (vma->vm_end < vma->vm_start) 681 return -EINVAL; 682 683 vma->vm_private_data = idev; 684 685 mi = uio_find_mem_index(vma); 686 if (mi < 0) 687 return -EINVAL; 688 689 requested_pages = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; 690 actual_pages = ((idev->info->mem[mi].addr & ~PAGE_MASK) 691 + idev->info->mem[mi].size + PAGE_SIZE -1) >> PAGE_SHIFT; 692 if (requested_pages > actual_pages) 693 return -EINVAL; 694 695 if (idev->info->mmap) { 696 ret = idev->info->mmap(idev->info, vma); 697 return ret; 698 } 699 700 switch (idev->info->mem[mi].memtype) { 701 case UIO_MEM_PHYS: 702 return uio_mmap_physical(vma); 703 case UIO_MEM_LOGICAL: 704 case UIO_MEM_VIRTUAL: 705 return uio_mmap_logical(vma); 706 default: 707 return -EINVAL; 708 } 709 } 710 711 static const struct file_operations uio_fops = { 712 .owner = THIS_MODULE, 713 .open = uio_open, 714 .release = uio_release, 715 .read = uio_read, 716 .write = uio_write, 717 .mmap = uio_mmap, 718 .poll = uio_poll, 719 .fasync = uio_fasync, 720 .llseek = noop_llseek, 721 }; 722 723 static int uio_major_init(void) 724 { 725 static const char name[] = "uio"; 726 struct cdev *cdev = NULL; 727 dev_t uio_dev = 0; 728 int result; 729 730 result = alloc_chrdev_region(&uio_dev, 0, UIO_MAX_DEVICES, name); 731 if (result) 732 goto out; 733 734 result = -ENOMEM; 735 cdev = cdev_alloc(); 736 if (!cdev) 737 goto out_unregister; 738 739 cdev->owner = THIS_MODULE; 740 cdev->ops = &uio_fops; 741 kobject_set_name(&cdev->kobj, "%s", name); 742 743 result = cdev_add(cdev, uio_dev, UIO_MAX_DEVICES); 744 if (result) 745 goto out_put; 746 747 uio_major = MAJOR(uio_dev); 748 uio_cdev = cdev; 749 result = 0; 750 out: 751 return result; 752 out_put: 753 kobject_put(&cdev->kobj); 754 out_unregister: 755 unregister_chrdev_region(uio_dev, UIO_MAX_DEVICES); 756 goto out; 757 } 758 759 static void uio_major_cleanup(void) 760 { 761 unregister_chrdev_region(MKDEV(uio_major, 0), UIO_MAX_DEVICES); 762 cdev_del(uio_cdev); 763 } 764 765 static int init_uio_class(void) 766 { 767 int ret; 768 769 /* This is the first time in here, set everything up properly */ 770 ret = uio_major_init(); 771 if (ret) 772 goto exit; 773 774 ret = class_register(&uio_class); 775 if (ret) { 776 printk(KERN_ERR "class_register failed for uio\n"); 777 goto err_class_register; 778 } 779 return 0; 780 781 err_class_register: 782 uio_major_cleanup(); 783 exit: 784 return ret; 785 } 786 787 static void release_uio_class(void) 788 { 789 class_unregister(&uio_class); 790 uio_major_cleanup(); 791 } 792 793 /** 794 * uio_register_device - register a new userspace IO device 795 * @owner: module that creates the new device 796 * @parent: parent device 797 * @info: UIO device capabilities 798 * 799 * returns zero on success or a negative error code. 800 */ 801 int __uio_register_device(struct module *owner, 802 struct device *parent, 803 struct uio_info *info) 804 { 805 struct uio_device *idev; 806 int ret = 0; 807 808 if (!parent || !info || !info->name || !info->version) 809 return -EINVAL; 810 811 info->uio_dev = NULL; 812 813 idev = kzalloc(sizeof(*idev), GFP_KERNEL); 814 if (!idev) { 815 ret = -ENOMEM; 816 goto err_kzalloc; 817 } 818 819 idev->owner = owner; 820 idev->info = info; 821 init_waitqueue_head(&idev->wait); 822 atomic_set(&idev->event, 0); 823 824 ret = uio_get_minor(idev); 825 if (ret) 826 goto err_get_minor; 827 828 idev->dev = device_create(&uio_class, parent, 829 MKDEV(uio_major, idev->minor), idev, 830 "uio%d", idev->minor); 831 if (IS_ERR(idev->dev)) { 832 printk(KERN_ERR "UIO: device register failed\n"); 833 ret = PTR_ERR(idev->dev); 834 goto err_device_create; 835 } 836 837 ret = uio_dev_add_attributes(idev); 838 if (ret) 839 goto err_uio_dev_add_attributes; 840 841 info->uio_dev = idev; 842 843 if (info->irq && (info->irq != UIO_IRQ_CUSTOM)) { 844 ret = request_irq(info->irq, uio_interrupt, 845 info->irq_flags, info->name, idev); 846 if (ret) 847 goto err_request_irq; 848 } 849 850 return 0; 851 852 err_request_irq: 853 uio_dev_del_attributes(idev); 854 err_uio_dev_add_attributes: 855 device_destroy(&uio_class, MKDEV(uio_major, idev->minor)); 856 err_device_create: 857 uio_free_minor(idev); 858 err_get_minor: 859 kfree(idev); 860 err_kzalloc: 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 if (info->irq && (info->irq != UIO_IRQ_CUSTOM)) 882 free_irq(info->irq, idev); 883 884 uio_dev_del_attributes(idev); 885 886 device_destroy(&uio_class, MKDEV(uio_major, idev->minor)); 887 kfree(idev); 888 889 return; 890 } 891 EXPORT_SYMBOL_GPL(uio_unregister_device); 892 893 static int __init uio_init(void) 894 { 895 return init_uio_class(); 896 } 897 898 static void __exit uio_exit(void) 899 { 900 release_uio_class(); 901 } 902 903 module_init(uio_init) 904 module_exit(uio_exit) 905 MODULE_LICENSE("GPL v2"); 906