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%llx\n", (unsigned long long)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%llx\n", (unsigned long long)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; 372 373 mutex_lock(&minor_lock); 374 retval = idr_alloc(&uio_idr, idev, 0, UIO_MAX_DEVICES, GFP_KERNEL); 375 if (retval >= 0) { 376 idev->minor = retval; 377 retval = 0; 378 } else if (retval == -ENOSPC) { 379 dev_err(idev->dev, "too many uio devices\n"); 380 retval = -EINVAL; 381 } 382 mutex_unlock(&minor_lock); 383 return retval; 384 } 385 386 static void uio_free_minor(struct uio_device *idev) 387 { 388 mutex_lock(&minor_lock); 389 idr_remove(&uio_idr, idev->minor); 390 mutex_unlock(&minor_lock); 391 } 392 393 /** 394 * uio_event_notify - trigger an interrupt event 395 * @info: UIO device capabilities 396 */ 397 void uio_event_notify(struct uio_info *info) 398 { 399 struct uio_device *idev = info->uio_dev; 400 401 atomic_inc(&idev->event); 402 wake_up_interruptible(&idev->wait); 403 kill_fasync(&idev->async_queue, SIGIO, POLL_IN); 404 } 405 EXPORT_SYMBOL_GPL(uio_event_notify); 406 407 /** 408 * uio_interrupt - hardware interrupt handler 409 * @irq: IRQ number, can be UIO_IRQ_CYCLIC for cyclic timer 410 * @dev_id: Pointer to the devices uio_device structure 411 */ 412 static irqreturn_t uio_interrupt(int irq, void *dev_id) 413 { 414 struct uio_device *idev = (struct uio_device *)dev_id; 415 irqreturn_t ret = idev->info->handler(irq, idev->info); 416 417 if (ret == IRQ_HANDLED) 418 uio_event_notify(idev->info); 419 420 return ret; 421 } 422 423 struct uio_listener { 424 struct uio_device *dev; 425 s32 event_count; 426 }; 427 428 static int uio_open(struct inode *inode, struct file *filep) 429 { 430 struct uio_device *idev; 431 struct uio_listener *listener; 432 int ret = 0; 433 434 mutex_lock(&minor_lock); 435 idev = idr_find(&uio_idr, iminor(inode)); 436 mutex_unlock(&minor_lock); 437 if (!idev) { 438 ret = -ENODEV; 439 goto out; 440 } 441 442 if (!try_module_get(idev->owner)) { 443 ret = -ENODEV; 444 goto out; 445 } 446 447 listener = kmalloc(sizeof(*listener), GFP_KERNEL); 448 if (!listener) { 449 ret = -ENOMEM; 450 goto err_alloc_listener; 451 } 452 453 listener->dev = idev; 454 listener->event_count = atomic_read(&idev->event); 455 filep->private_data = listener; 456 457 if (idev->info->open) { 458 ret = idev->info->open(idev->info, inode); 459 if (ret) 460 goto err_infoopen; 461 } 462 return 0; 463 464 err_infoopen: 465 kfree(listener); 466 467 err_alloc_listener: 468 module_put(idev->owner); 469 470 out: 471 return ret; 472 } 473 474 static int uio_fasync(int fd, struct file *filep, int on) 475 { 476 struct uio_listener *listener = filep->private_data; 477 struct uio_device *idev = listener->dev; 478 479 return fasync_helper(fd, filep, on, &idev->async_queue); 480 } 481 482 static int uio_release(struct inode *inode, struct file *filep) 483 { 484 int ret = 0; 485 struct uio_listener *listener = filep->private_data; 486 struct uio_device *idev = listener->dev; 487 488 if (idev->info->release) 489 ret = idev->info->release(idev->info, inode); 490 491 module_put(idev->owner); 492 kfree(listener); 493 return ret; 494 } 495 496 static unsigned int uio_poll(struct file *filep, poll_table *wait) 497 { 498 struct uio_listener *listener = filep->private_data; 499 struct uio_device *idev = listener->dev; 500 501 if (!idev->info->irq) 502 return -EIO; 503 504 poll_wait(filep, &idev->wait, wait); 505 if (listener->event_count != atomic_read(&idev->event)) 506 return POLLIN | POLLRDNORM; 507 return 0; 508 } 509 510 static ssize_t uio_read(struct file *filep, char __user *buf, 511 size_t count, loff_t *ppos) 512 { 513 struct uio_listener *listener = filep->private_data; 514 struct uio_device *idev = listener->dev; 515 DECLARE_WAITQUEUE(wait, current); 516 ssize_t retval; 517 s32 event_count; 518 519 if (!idev->info->irq) 520 return -EIO; 521 522 if (count != sizeof(s32)) 523 return -EINVAL; 524 525 add_wait_queue(&idev->wait, &wait); 526 527 do { 528 set_current_state(TASK_INTERRUPTIBLE); 529 530 event_count = atomic_read(&idev->event); 531 if (event_count != listener->event_count) { 532 if (copy_to_user(buf, &event_count, count)) 533 retval = -EFAULT; 534 else { 535 listener->event_count = event_count; 536 retval = count; 537 } 538 break; 539 } 540 541 if (filep->f_flags & O_NONBLOCK) { 542 retval = -EAGAIN; 543 break; 544 } 545 546 if (signal_pending(current)) { 547 retval = -ERESTARTSYS; 548 break; 549 } 550 schedule(); 551 } while (1); 552 553 __set_current_state(TASK_RUNNING); 554 remove_wait_queue(&idev->wait, &wait); 555 556 return retval; 557 } 558 559 static ssize_t uio_write(struct file *filep, const char __user *buf, 560 size_t count, loff_t *ppos) 561 { 562 struct uio_listener *listener = filep->private_data; 563 struct uio_device *idev = listener->dev; 564 ssize_t retval; 565 s32 irq_on; 566 567 if (!idev->info->irq) 568 return -EIO; 569 570 if (count != sizeof(s32)) 571 return -EINVAL; 572 573 if (!idev->info->irqcontrol) 574 return -ENOSYS; 575 576 if (copy_from_user(&irq_on, buf, count)) 577 return -EFAULT; 578 579 retval = idev->info->irqcontrol(idev->info, irq_on); 580 581 return retval ? retval : sizeof(s32); 582 } 583 584 static int uio_find_mem_index(struct vm_area_struct *vma) 585 { 586 struct uio_device *idev = vma->vm_private_data; 587 588 if (vma->vm_pgoff < MAX_UIO_MAPS) { 589 if (idev->info->mem[vma->vm_pgoff].size == 0) 590 return -1; 591 return (int)vma->vm_pgoff; 592 } 593 return -1; 594 } 595 596 static void uio_vma_open(struct vm_area_struct *vma) 597 { 598 struct uio_device *idev = vma->vm_private_data; 599 idev->vma_count++; 600 } 601 602 static void uio_vma_close(struct vm_area_struct *vma) 603 { 604 struct uio_device *idev = vma->vm_private_data; 605 idev->vma_count--; 606 } 607 608 static int uio_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf) 609 { 610 struct uio_device *idev = vma->vm_private_data; 611 struct page *page; 612 unsigned long offset; 613 614 int mi = uio_find_mem_index(vma); 615 if (mi < 0) 616 return VM_FAULT_SIGBUS; 617 618 /* 619 * We need to subtract mi because userspace uses offset = N*PAGE_SIZE 620 * to use mem[N]. 621 */ 622 offset = (vmf->pgoff - mi) << PAGE_SHIFT; 623 624 if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL) 625 page = virt_to_page(idev->info->mem[mi].addr + offset); 626 else 627 page = vmalloc_to_page((void *)(unsigned long)idev->info->mem[mi].addr + offset); 628 get_page(page); 629 vmf->page = page; 630 return 0; 631 } 632 633 static const struct vm_operations_struct uio_vm_ops = { 634 .open = uio_vma_open, 635 .close = uio_vma_close, 636 .fault = uio_vma_fault, 637 }; 638 639 static int uio_mmap_physical(struct vm_area_struct *vma) 640 { 641 struct uio_device *idev = vma->vm_private_data; 642 int mi = uio_find_mem_index(vma); 643 if (mi < 0) 644 return -EINVAL; 645 646 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); 647 648 return remap_pfn_range(vma, 649 vma->vm_start, 650 idev->info->mem[mi].addr >> PAGE_SHIFT, 651 vma->vm_end - vma->vm_start, 652 vma->vm_page_prot); 653 } 654 655 static int uio_mmap_logical(struct vm_area_struct *vma) 656 { 657 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP; 658 vma->vm_ops = &uio_vm_ops; 659 uio_vma_open(vma); 660 return 0; 661 } 662 663 static int uio_mmap(struct file *filep, struct vm_area_struct *vma) 664 { 665 struct uio_listener *listener = filep->private_data; 666 struct uio_device *idev = listener->dev; 667 int mi; 668 unsigned long requested_pages, actual_pages; 669 int ret = 0; 670 671 if (vma->vm_end < vma->vm_start) 672 return -EINVAL; 673 674 vma->vm_private_data = idev; 675 676 mi = uio_find_mem_index(vma); 677 if (mi < 0) 678 return -EINVAL; 679 680 requested_pages = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; 681 actual_pages = ((idev->info->mem[mi].addr & ~PAGE_MASK) 682 + idev->info->mem[mi].size + PAGE_SIZE -1) >> PAGE_SHIFT; 683 if (requested_pages > actual_pages) 684 return -EINVAL; 685 686 if (idev->info->mmap) { 687 ret = idev->info->mmap(idev->info, vma); 688 return ret; 689 } 690 691 switch (idev->info->mem[mi].memtype) { 692 case UIO_MEM_PHYS: 693 return uio_mmap_physical(vma); 694 case UIO_MEM_LOGICAL: 695 case UIO_MEM_VIRTUAL: 696 return uio_mmap_logical(vma); 697 default: 698 return -EINVAL; 699 } 700 } 701 702 static const struct file_operations uio_fops = { 703 .owner = THIS_MODULE, 704 .open = uio_open, 705 .release = uio_release, 706 .read = uio_read, 707 .write = uio_write, 708 .mmap = uio_mmap, 709 .poll = uio_poll, 710 .fasync = uio_fasync, 711 .llseek = noop_llseek, 712 }; 713 714 static int uio_major_init(void) 715 { 716 static const char name[] = "uio"; 717 struct cdev *cdev = NULL; 718 dev_t uio_dev = 0; 719 int result; 720 721 result = alloc_chrdev_region(&uio_dev, 0, UIO_MAX_DEVICES, name); 722 if (result) 723 goto out; 724 725 result = -ENOMEM; 726 cdev = cdev_alloc(); 727 if (!cdev) 728 goto out_unregister; 729 730 cdev->owner = THIS_MODULE; 731 cdev->ops = &uio_fops; 732 kobject_set_name(&cdev->kobj, "%s", name); 733 734 result = cdev_add(cdev, uio_dev, UIO_MAX_DEVICES); 735 if (result) 736 goto out_put; 737 738 uio_major = MAJOR(uio_dev); 739 uio_cdev = cdev; 740 return 0; 741 out_put: 742 kobject_put(&cdev->kobj); 743 out_unregister: 744 unregister_chrdev_region(uio_dev, UIO_MAX_DEVICES); 745 out: 746 return result; 747 } 748 749 static void uio_major_cleanup(void) 750 { 751 unregister_chrdev_region(MKDEV(uio_major, 0), UIO_MAX_DEVICES); 752 cdev_del(uio_cdev); 753 } 754 755 static int init_uio_class(void) 756 { 757 int ret; 758 759 /* This is the first time in here, set everything up properly */ 760 ret = uio_major_init(); 761 if (ret) 762 goto exit; 763 764 ret = class_register(&uio_class); 765 if (ret) { 766 printk(KERN_ERR "class_register failed for uio\n"); 767 goto err_class_register; 768 } 769 return 0; 770 771 err_class_register: 772 uio_major_cleanup(); 773 exit: 774 return ret; 775 } 776 777 static void release_uio_class(void) 778 { 779 class_unregister(&uio_class); 780 uio_major_cleanup(); 781 } 782 783 /** 784 * uio_register_device - register a new userspace IO device 785 * @owner: module that creates the new device 786 * @parent: parent device 787 * @info: UIO device capabilities 788 * 789 * returns zero on success or a negative error code. 790 */ 791 int __uio_register_device(struct module *owner, 792 struct device *parent, 793 struct uio_info *info) 794 { 795 struct uio_device *idev; 796 int ret = 0; 797 798 if (!parent || !info || !info->name || !info->version) 799 return -EINVAL; 800 801 info->uio_dev = NULL; 802 803 idev = kzalloc(sizeof(*idev), GFP_KERNEL); 804 if (!idev) { 805 ret = -ENOMEM; 806 goto err_kzalloc; 807 } 808 809 idev->owner = owner; 810 idev->info = info; 811 init_waitqueue_head(&idev->wait); 812 atomic_set(&idev->event, 0); 813 814 ret = uio_get_minor(idev); 815 if (ret) 816 goto err_get_minor; 817 818 idev->dev = device_create(&uio_class, parent, 819 MKDEV(uio_major, idev->minor), idev, 820 "uio%d", idev->minor); 821 if (IS_ERR(idev->dev)) { 822 printk(KERN_ERR "UIO: device register failed\n"); 823 ret = PTR_ERR(idev->dev); 824 goto err_device_create; 825 } 826 827 ret = uio_dev_add_attributes(idev); 828 if (ret) 829 goto err_uio_dev_add_attributes; 830 831 info->uio_dev = idev; 832 833 if (info->irq && (info->irq != UIO_IRQ_CUSTOM)) { 834 ret = request_irq(info->irq, uio_interrupt, 835 info->irq_flags, info->name, idev); 836 if (ret) 837 goto err_request_irq; 838 } 839 840 return 0; 841 842 err_request_irq: 843 uio_dev_del_attributes(idev); 844 err_uio_dev_add_attributes: 845 device_destroy(&uio_class, MKDEV(uio_major, idev->minor)); 846 err_device_create: 847 uio_free_minor(idev); 848 err_get_minor: 849 kfree(idev); 850 err_kzalloc: 851 return ret; 852 } 853 EXPORT_SYMBOL_GPL(__uio_register_device); 854 855 /** 856 * uio_unregister_device - unregister a industrial IO device 857 * @info: UIO device capabilities 858 * 859 */ 860 void uio_unregister_device(struct uio_info *info) 861 { 862 struct uio_device *idev; 863 864 if (!info || !info->uio_dev) 865 return; 866 867 idev = info->uio_dev; 868 869 uio_free_minor(idev); 870 871 if (info->irq && (info->irq != UIO_IRQ_CUSTOM)) 872 free_irq(info->irq, idev); 873 874 uio_dev_del_attributes(idev); 875 876 device_destroy(&uio_class, MKDEV(uio_major, idev->minor)); 877 kfree(idev); 878 879 return; 880 } 881 EXPORT_SYMBOL_GPL(uio_unregister_device); 882 883 static int __init uio_init(void) 884 { 885 return init_uio_class(); 886 } 887 888 static void __exit uio_exit(void) 889 { 890 release_uio_class(); 891 } 892 893 module_init(uio_init) 894 module_exit(uio_exit) 895 MODULE_LICENSE("GPL v2"); 896