uio.c revision 632fefaf1fff7c344191c363e08a43cf006fe60e
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_kobj; 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_kobj; 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_kobj; 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_kobj; 324 ret = kobject_uevent(&portio->kobj, KOBJ_ADD); 325 if (ret) 326 goto err_portio; 327 } 328 329 return 0; 330 331err_portio: 332 pi--; 333err_portio_kobj: 334 for (; pi >= 0; pi--) { 335 port = &idev->info->port[pi]; 336 portio = port->portio; 337 kobject_put(&portio->kobj); 338 } 339 kobject_put(idev->portio_dir); 340err_map: 341 mi--; 342err_map_kobj: 343 for (; mi >= 0; mi--) { 344 mem = &idev->info->mem[mi]; 345 map = mem->map; 346 kobject_put(&map->kobj); 347 } 348 kobject_put(idev->map_dir); 349 dev_err(idev->dev, "error creating sysfs files (%d)\n", ret); 350 return ret; 351} 352 353static void uio_dev_del_attributes(struct uio_device *idev) 354{ 355 int i; 356 struct uio_mem *mem; 357 struct uio_port *port; 358 359 for (i = 0; i < MAX_UIO_MAPS; i++) { 360 mem = &idev->info->mem[i]; 361 if (mem->size == 0) 362 break; 363 kobject_put(&mem->map->kobj); 364 } 365 kobject_put(idev->map_dir); 366 367 for (i = 0; i < MAX_UIO_PORT_REGIONS; i++) { 368 port = &idev->info->port[i]; 369 if (port->size == 0) 370 break; 371 kobject_put(&port->portio->kobj); 372 } 373 kobject_put(idev->portio_dir); 374} 375 376static int uio_get_minor(struct uio_device *idev) 377{ 378 int retval = -ENOMEM; 379 380 mutex_lock(&minor_lock); 381 retval = idr_alloc(&uio_idr, idev, 0, UIO_MAX_DEVICES, GFP_KERNEL); 382 if (retval >= 0) { 383 idev->minor = retval; 384 retval = 0; 385 } else if (retval == -ENOSPC) { 386 dev_err(idev->dev, "too many uio devices\n"); 387 retval = -EINVAL; 388 } 389 mutex_unlock(&minor_lock); 390 return retval; 391} 392 393static void uio_free_minor(struct uio_device *idev) 394{ 395 mutex_lock(&minor_lock); 396 idr_remove(&uio_idr, idev->minor); 397 mutex_unlock(&minor_lock); 398} 399 400/** 401 * uio_event_notify - trigger an interrupt event 402 * @info: UIO device capabilities 403 */ 404void uio_event_notify(struct uio_info *info) 405{ 406 struct uio_device *idev = info->uio_dev; 407 408 atomic_inc(&idev->event); 409 wake_up_interruptible(&idev->wait); 410 kill_fasync(&idev->async_queue, SIGIO, POLL_IN); 411} 412EXPORT_SYMBOL_GPL(uio_event_notify); 413 414/** 415 * uio_interrupt - hardware interrupt handler 416 * @irq: IRQ number, can be UIO_IRQ_CYCLIC for cyclic timer 417 * @dev_id: Pointer to the devices uio_device structure 418 */ 419static irqreturn_t uio_interrupt(int irq, void *dev_id) 420{ 421 struct uio_device *idev = (struct uio_device *)dev_id; 422 irqreturn_t ret = idev->info->handler(irq, idev->info); 423 424 if (ret == IRQ_HANDLED) 425 uio_event_notify(idev->info); 426 427 return ret; 428} 429 430struct uio_listener { 431 struct uio_device *dev; 432 s32 event_count; 433}; 434 435static int uio_open(struct inode *inode, struct file *filep) 436{ 437 struct uio_device *idev; 438 struct uio_listener *listener; 439 int ret = 0; 440 441 mutex_lock(&minor_lock); 442 idev = idr_find(&uio_idr, iminor(inode)); 443 mutex_unlock(&minor_lock); 444 if (!idev) { 445 ret = -ENODEV; 446 goto out; 447 } 448 449 if (!try_module_get(idev->owner)) { 450 ret = -ENODEV; 451 goto out; 452 } 453 454 listener = kmalloc(sizeof(*listener), GFP_KERNEL); 455 if (!listener) { 456 ret = -ENOMEM; 457 goto err_alloc_listener; 458 } 459 460 listener->dev = idev; 461 listener->event_count = atomic_read(&idev->event); 462 filep->private_data = listener; 463 464 if (idev->info->open) { 465 ret = idev->info->open(idev->info, inode); 466 if (ret) 467 goto err_infoopen; 468 } 469 return 0; 470 471err_infoopen: 472 kfree(listener); 473 474err_alloc_listener: 475 module_put(idev->owner); 476 477out: 478 return ret; 479} 480 481static int uio_fasync(int fd, struct file *filep, int on) 482{ 483 struct uio_listener *listener = filep->private_data; 484 struct uio_device *idev = listener->dev; 485 486 return fasync_helper(fd, filep, on, &idev->async_queue); 487} 488 489static int uio_release(struct inode *inode, struct file *filep) 490{ 491 int ret = 0; 492 struct uio_listener *listener = filep->private_data; 493 struct uio_device *idev = listener->dev; 494 495 if (idev->info->release) 496 ret = idev->info->release(idev->info, inode); 497 498 module_put(idev->owner); 499 kfree(listener); 500 return ret; 501} 502 503static unsigned int uio_poll(struct file *filep, poll_table *wait) 504{ 505 struct uio_listener *listener = filep->private_data; 506 struct uio_device *idev = listener->dev; 507 508 if (!idev->info->irq) 509 return -EIO; 510 511 poll_wait(filep, &idev->wait, wait); 512 if (listener->event_count != atomic_read(&idev->event)) 513 return POLLIN | POLLRDNORM; 514 return 0; 515} 516 517static ssize_t uio_read(struct file *filep, char __user *buf, 518 size_t count, loff_t *ppos) 519{ 520 struct uio_listener *listener = filep->private_data; 521 struct uio_device *idev = listener->dev; 522 DECLARE_WAITQUEUE(wait, current); 523 ssize_t retval; 524 s32 event_count; 525 526 if (!idev->info->irq) 527 return -EIO; 528 529 if (count != sizeof(s32)) 530 return -EINVAL; 531 532 add_wait_queue(&idev->wait, &wait); 533 534 do { 535 set_current_state(TASK_INTERRUPTIBLE); 536 537 event_count = atomic_read(&idev->event); 538 if (event_count != listener->event_count) { 539 if (copy_to_user(buf, &event_count, count)) 540 retval = -EFAULT; 541 else { 542 listener->event_count = event_count; 543 retval = count; 544 } 545 break; 546 } 547 548 if (filep->f_flags & O_NONBLOCK) { 549 retval = -EAGAIN; 550 break; 551 } 552 553 if (signal_pending(current)) { 554 retval = -ERESTARTSYS; 555 break; 556 } 557 schedule(); 558 } while (1); 559 560 __set_current_state(TASK_RUNNING); 561 remove_wait_queue(&idev->wait, &wait); 562 563 return retval; 564} 565 566static ssize_t uio_write(struct file *filep, const char __user *buf, 567 size_t count, loff_t *ppos) 568{ 569 struct uio_listener *listener = filep->private_data; 570 struct uio_device *idev = listener->dev; 571 ssize_t retval; 572 s32 irq_on; 573 574 if (!idev->info->irq) 575 return -EIO; 576 577 if (count != sizeof(s32)) 578 return -EINVAL; 579 580 if (!idev->info->irqcontrol) 581 return -ENOSYS; 582 583 if (copy_from_user(&irq_on, buf, count)) 584 return -EFAULT; 585 586 retval = idev->info->irqcontrol(idev->info, irq_on); 587 588 return retval ? retval : sizeof(s32); 589} 590 591static int uio_find_mem_index(struct vm_area_struct *vma) 592{ 593 struct uio_device *idev = vma->vm_private_data; 594 595 if (vma->vm_pgoff < MAX_UIO_MAPS) { 596 if (idev->info->mem[vma->vm_pgoff].size == 0) 597 return -1; 598 return (int)vma->vm_pgoff; 599 } 600 return -1; 601} 602 603static int uio_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf) 604{ 605 struct uio_device *idev = vma->vm_private_data; 606 struct page *page; 607 unsigned long offset; 608 void *addr; 609 610 int mi = uio_find_mem_index(vma); 611 if (mi < 0) 612 return VM_FAULT_SIGBUS; 613 614 /* 615 * We need to subtract mi because userspace uses offset = N*PAGE_SIZE 616 * to use mem[N]. 617 */ 618 offset = (vmf->pgoff - mi) << PAGE_SHIFT; 619 620 addr = (void *)(unsigned long)idev->info->mem[mi].addr + offset; 621 if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL) 622 page = virt_to_page(addr); 623 else 624 page = vmalloc_to_page(addr); 625 get_page(page); 626 vmf->page = page; 627 return 0; 628} 629 630static const struct vm_operations_struct uio_logical_vm_ops = { 631 .fault = uio_vma_fault, 632}; 633 634static int uio_mmap_logical(struct vm_area_struct *vma) 635{ 636 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP; 637 vma->vm_ops = &uio_logical_vm_ops; 638 return 0; 639} 640 641static const struct vm_operations_struct uio_physical_vm_ops = { 642#ifdef CONFIG_HAVE_IOREMAP_PROT 643 .access = generic_access_phys, 644#endif 645}; 646 647static int uio_mmap_physical(struct vm_area_struct *vma) 648{ 649 struct uio_device *idev = vma->vm_private_data; 650 int mi = uio_find_mem_index(vma); 651 struct uio_mem *mem; 652 if (mi < 0) 653 return -EINVAL; 654 mem = idev->info->mem + mi; 655 656 if (mem->addr & ~PAGE_MASK) 657 return -ENODEV; 658 if (vma->vm_end - vma->vm_start > mem->size) 659 return -EINVAL; 660 661 vma->vm_ops = &uio_physical_vm_ops; 662 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); 663 664 /* 665 * We cannot use the vm_iomap_memory() helper here, 666 * because vma->vm_pgoff is the map index we looked 667 * up above in uio_find_mem_index(), rather than an 668 * actual page offset into the mmap. 669 * 670 * So we just do the physical mmap without a page 671 * offset. 672 */ 673 return remap_pfn_range(vma, 674 vma->vm_start, 675 mem->addr >> PAGE_SHIFT, 676 vma->vm_end - vma->vm_start, 677 vma->vm_page_prot); 678} 679 680static int uio_mmap(struct file *filep, struct vm_area_struct *vma) 681{ 682 struct uio_listener *listener = filep->private_data; 683 struct uio_device *idev = listener->dev; 684 int mi; 685 unsigned long requested_pages, actual_pages; 686 int ret = 0; 687 688 if (vma->vm_end < vma->vm_start) 689 return -EINVAL; 690 691 vma->vm_private_data = idev; 692 693 mi = uio_find_mem_index(vma); 694 if (mi < 0) 695 return -EINVAL; 696 697 requested_pages = vma_pages(vma); 698 actual_pages = ((idev->info->mem[mi].addr & ~PAGE_MASK) 699 + idev->info->mem[mi].size + PAGE_SIZE -1) >> PAGE_SHIFT; 700 if (requested_pages > actual_pages) 701 return -EINVAL; 702 703 if (idev->info->mmap) { 704 ret = idev->info->mmap(idev->info, vma); 705 return ret; 706 } 707 708 switch (idev->info->mem[mi].memtype) { 709 case UIO_MEM_PHYS: 710 return uio_mmap_physical(vma); 711 case UIO_MEM_LOGICAL: 712 case UIO_MEM_VIRTUAL: 713 return uio_mmap_logical(vma); 714 default: 715 return -EINVAL; 716 } 717} 718 719static const struct file_operations uio_fops = { 720 .owner = THIS_MODULE, 721 .open = uio_open, 722 .release = uio_release, 723 .read = uio_read, 724 .write = uio_write, 725 .mmap = uio_mmap, 726 .poll = uio_poll, 727 .fasync = uio_fasync, 728 .llseek = noop_llseek, 729}; 730 731static int uio_major_init(void) 732{ 733 static const char name[] = "uio"; 734 struct cdev *cdev = NULL; 735 dev_t uio_dev = 0; 736 int result; 737 738 result = alloc_chrdev_region(&uio_dev, 0, UIO_MAX_DEVICES, name); 739 if (result) 740 goto out; 741 742 result = -ENOMEM; 743 cdev = cdev_alloc(); 744 if (!cdev) 745 goto out_unregister; 746 747 cdev->owner = THIS_MODULE; 748 cdev->ops = &uio_fops; 749 kobject_set_name(&cdev->kobj, "%s", name); 750 751 result = cdev_add(cdev, uio_dev, UIO_MAX_DEVICES); 752 if (result) 753 goto out_put; 754 755 uio_major = MAJOR(uio_dev); 756 uio_cdev = cdev; 757 return 0; 758out_put: 759 kobject_put(&cdev->kobj); 760out_unregister: 761 unregister_chrdev_region(uio_dev, UIO_MAX_DEVICES); 762out: 763 return result; 764} 765 766static void uio_major_cleanup(void) 767{ 768 unregister_chrdev_region(MKDEV(uio_major, 0), UIO_MAX_DEVICES); 769 cdev_del(uio_cdev); 770} 771 772static int init_uio_class(void) 773{ 774 int ret; 775 776 /* This is the first time in here, set everything up properly */ 777 ret = uio_major_init(); 778 if (ret) 779 goto exit; 780 781 ret = class_register(&uio_class); 782 if (ret) { 783 printk(KERN_ERR "class_register failed for uio\n"); 784 goto err_class_register; 785 } 786 return 0; 787 788err_class_register: 789 uio_major_cleanup(); 790exit: 791 return ret; 792} 793 794static void release_uio_class(void) 795{ 796 class_unregister(&uio_class); 797 uio_major_cleanup(); 798} 799 800/** 801 * uio_register_device - register a new userspace IO device 802 * @owner: module that creates the new device 803 * @parent: parent device 804 * @info: UIO device capabilities 805 * 806 * returns zero on success or a negative error code. 807 */ 808int __uio_register_device(struct module *owner, 809 struct device *parent, 810 struct uio_info *info) 811{ 812 struct uio_device *idev; 813 int ret = 0; 814 815 if (!parent || !info || !info->name || !info->version) 816 return -EINVAL; 817 818 info->uio_dev = NULL; 819 820 idev = devm_kzalloc(parent, sizeof(*idev), GFP_KERNEL); 821 if (!idev) { 822 return -ENOMEM; 823 } 824 825 idev->owner = owner; 826 idev->info = info; 827 init_waitqueue_head(&idev->wait); 828 atomic_set(&idev->event, 0); 829 830 ret = uio_get_minor(idev); 831 if (ret) 832 return ret; 833 834 idev->dev = device_create(&uio_class, parent, 835 MKDEV(uio_major, idev->minor), idev, 836 "uio%d", idev->minor); 837 if (IS_ERR(idev->dev)) { 838 printk(KERN_ERR "UIO: device register failed\n"); 839 ret = PTR_ERR(idev->dev); 840 goto err_device_create; 841 } 842 843 ret = uio_dev_add_attributes(idev); 844 if (ret) 845 goto err_uio_dev_add_attributes; 846 847 info->uio_dev = idev; 848 849 if (info->irq && (info->irq != UIO_IRQ_CUSTOM)) { 850 ret = devm_request_irq(idev->dev, info->irq, uio_interrupt, 851 info->irq_flags, info->name, idev); 852 if (ret) 853 goto err_request_irq; 854 } 855 856 return 0; 857 858err_request_irq: 859 uio_dev_del_attributes(idev); 860err_uio_dev_add_attributes: 861 device_destroy(&uio_class, MKDEV(uio_major, idev->minor)); 862err_device_create: 863 uio_free_minor(idev); 864 return ret; 865} 866EXPORT_SYMBOL_GPL(__uio_register_device); 867 868/** 869 * uio_unregister_device - unregister a industrial IO device 870 * @info: UIO device capabilities 871 * 872 */ 873void uio_unregister_device(struct uio_info *info) 874{ 875 struct uio_device *idev; 876 877 if (!info || !info->uio_dev) 878 return; 879 880 idev = info->uio_dev; 881 882 uio_free_minor(idev); 883 884 uio_dev_del_attributes(idev); 885 886 device_destroy(&uio_class, MKDEV(uio_major, idev->minor)); 887 888 return; 889} 890EXPORT_SYMBOL_GPL(uio_unregister_device); 891 892static int __init uio_init(void) 893{ 894 return init_uio_class(); 895} 896 897static void __exit uio_exit(void) 898{ 899 release_uio_class(); 900} 901 902module_init(uio_init) 903module_exit(uio_exit) 904MODULE_LICENSE("GPL v2"); 905