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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
31static int uio_major;
32static struct cdev *uio_cdev;
33static DEFINE_IDR(uio_idr);
34static const struct file_operations uio_fops;
35
36
37static DEFINE_MUTEX(minor_lock);
38
39
40
41
42
43struct uio_map {
44 struct kobject kobj;
45 struct uio_mem *mem;
46};
47#define to_map(map) container_of(map, struct uio_map, kobj)
48
49static ssize_t map_name_show(struct uio_mem *mem, char *buf)
50{
51 if (unlikely(!mem->name))
52 mem->name = "";
53
54 return sprintf(buf, "%s\n", mem->name);
55}
56
57static ssize_t map_addr_show(struct uio_mem *mem, char *buf)
58{
59 return sprintf(buf, "%pa\n", &mem->addr);
60}
61
62static ssize_t map_size_show(struct uio_mem *mem, char *buf)
63{
64 return sprintf(buf, "%pa\n", &mem->size);
65}
66
67static ssize_t map_offset_show(struct uio_mem *mem, char *buf)
68{
69 return sprintf(buf, "0x%llx\n", (unsigned long long)mem->addr & ~PAGE_MASK);
70}
71
72struct map_sysfs_entry {
73 struct attribute attr;
74 ssize_t (*show)(struct uio_mem *, char *);
75 ssize_t (*store)(struct uio_mem *, const char *, size_t);
76};
77
78static struct map_sysfs_entry name_attribute =
79 __ATTR(name, S_IRUGO, map_name_show, NULL);
80static struct map_sysfs_entry addr_attribute =
81 __ATTR(addr, S_IRUGO, map_addr_show, NULL);
82static struct map_sysfs_entry size_attribute =
83 __ATTR(size, S_IRUGO, map_size_show, NULL);
84static struct map_sysfs_entry offset_attribute =
85 __ATTR(offset, S_IRUGO, map_offset_show, NULL);
86
87static struct attribute *attrs[] = {
88 &name_attribute.attr,
89 &addr_attribute.attr,
90 &size_attribute.attr,
91 &offset_attribute.attr,
92 NULL,
93};
94
95static void map_release(struct kobject *kobj)
96{
97 struct uio_map *map = to_map(kobj);
98 kfree(map);
99}
100
101static ssize_t map_type_show(struct kobject *kobj, struct attribute *attr,
102 char *buf)
103{
104 struct uio_map *map = to_map(kobj);
105 struct uio_mem *mem = map->mem;
106 struct map_sysfs_entry *entry;
107
108 entry = container_of(attr, struct map_sysfs_entry, attr);
109
110 if (!entry->show)
111 return -EIO;
112
113 return entry->show(mem, buf);
114}
115
116static const struct sysfs_ops map_sysfs_ops = {
117 .show = map_type_show,
118};
119
120static struct kobj_type map_attr_type = {
121 .release = map_release,
122 .sysfs_ops = &map_sysfs_ops,
123 .default_attrs = attrs,
124};
125
126struct uio_portio {
127 struct kobject kobj;
128 struct uio_port *port;
129};
130#define to_portio(portio) container_of(portio, struct uio_portio, kobj)
131
132static ssize_t portio_name_show(struct uio_port *port, char *buf)
133{
134 if (unlikely(!port->name))
135 port->name = "";
136
137 return sprintf(buf, "%s\n", port->name);
138}
139
140static ssize_t portio_start_show(struct uio_port *port, char *buf)
141{
142 return sprintf(buf, "0x%lx\n", port->start);
143}
144
145static ssize_t portio_size_show(struct uio_port *port, char *buf)
146{
147 return sprintf(buf, "0x%lx\n", port->size);
148}
149
150static ssize_t portio_porttype_show(struct uio_port *port, char *buf)
151{
152 const char *porttypes[] = {"none", "x86", "gpio", "other"};
153
154 if ((port->porttype < 0) || (port->porttype > UIO_PORT_OTHER))
155 return -EINVAL;
156
157 return sprintf(buf, "port_%s\n", porttypes[port->porttype]);
158}
159
160struct portio_sysfs_entry {
161 struct attribute attr;
162 ssize_t (*show)(struct uio_port *, char *);
163 ssize_t (*store)(struct uio_port *, const char *, size_t);
164};
165
166static struct portio_sysfs_entry portio_name_attribute =
167 __ATTR(name, S_IRUGO, portio_name_show, NULL);
168static struct portio_sysfs_entry portio_start_attribute =
169 __ATTR(start, S_IRUGO, portio_start_show, NULL);
170static struct portio_sysfs_entry portio_size_attribute =
171 __ATTR(size, S_IRUGO, portio_size_show, NULL);
172static struct portio_sysfs_entry portio_porttype_attribute =
173 __ATTR(porttype, S_IRUGO, portio_porttype_show, NULL);
174
175static struct attribute *portio_attrs[] = {
176 &portio_name_attribute.attr,
177 &portio_start_attribute.attr,
178 &portio_size_attribute.attr,
179 &portio_porttype_attribute.attr,
180 NULL,
181};
182
183static void portio_release(struct kobject *kobj)
184{
185 struct uio_portio *portio = to_portio(kobj);
186 kfree(portio);
187}
188
189static ssize_t portio_type_show(struct kobject *kobj, struct attribute *attr,
190 char *buf)
191{
192 struct uio_portio *portio = to_portio(kobj);
193 struct uio_port *port = portio->port;
194 struct portio_sysfs_entry *entry;
195
196 entry = container_of(attr, struct portio_sysfs_entry, attr);
197
198 if (!entry->show)
199 return -EIO;
200
201 return entry->show(port, buf);
202}
203
204static const struct sysfs_ops portio_sysfs_ops = {
205 .show = portio_type_show,
206};
207
208static struct kobj_type portio_attr_type = {
209 .release = portio_release,
210 .sysfs_ops = &portio_sysfs_ops,
211 .default_attrs = portio_attrs,
212};
213
214static ssize_t name_show(struct device *dev,
215 struct device_attribute *attr, char *buf)
216{
217 struct uio_device *idev = dev_get_drvdata(dev);
218 return sprintf(buf, "%s\n", idev->info->name);
219}
220static DEVICE_ATTR_RO(name);
221
222static ssize_t version_show(struct device *dev,
223 struct device_attribute *attr, char *buf)
224{
225 struct uio_device *idev = dev_get_drvdata(dev);
226 return sprintf(buf, "%s\n", idev->info->version);
227}
228static DEVICE_ATTR_RO(version);
229
230static ssize_t event_show(struct device *dev,
231 struct device_attribute *attr, char *buf)
232{
233 struct uio_device *idev = dev_get_drvdata(dev);
234 return sprintf(buf, "%u\n", (unsigned int)atomic_read(&idev->event));
235}
236static DEVICE_ATTR_RO(event);
237
238static struct attribute *uio_attrs[] = {
239 &dev_attr_name.attr,
240 &dev_attr_version.attr,
241 &dev_attr_event.attr,
242 NULL,
243};
244ATTRIBUTE_GROUPS(uio);
245
246
247static struct class uio_class = {
248 .name = "uio",
249 .dev_groups = uio_groups,
250};
251
252
253
254
255static int uio_dev_add_attributes(struct uio_device *idev)
256{
257 int ret;
258 int mi, pi;
259 int map_found = 0;
260 int portio_found = 0;
261 struct uio_mem *mem;
262 struct uio_map *map;
263 struct uio_port *port;
264 struct uio_portio *portio;
265
266 for (mi = 0; mi < MAX_UIO_MAPS; mi++) {
267 mem = &idev->info->mem[mi];
268 if (mem->size == 0)
269 break;
270 if (!map_found) {
271 map_found = 1;
272 idev->map_dir = kobject_create_and_add("maps",
273 &idev->dev->kobj);
274 if (!idev->map_dir)
275 goto err_map;
276 }
277 map = kzalloc(sizeof(*map), GFP_KERNEL);
278 if (!map)
279 goto err_map_kobj;
280 kobject_init(&map->kobj, &map_attr_type);
281 map->mem = mem;
282 mem->map = map;
283 ret = kobject_add(&map->kobj, idev->map_dir, "map%d", mi);
284 if (ret)
285 goto err_map_kobj;
286 ret = kobject_uevent(&map->kobj, KOBJ_ADD);
287 if (ret)
288 goto err_map;
289 }
290
291 for (pi = 0; pi < MAX_UIO_PORT_REGIONS; pi++) {
292 port = &idev->info->port[pi];
293 if (port->size == 0)
294 break;
295 if (!portio_found) {
296 portio_found = 1;
297 idev->portio_dir = kobject_create_and_add("portio",
298 &idev->dev->kobj);
299 if (!idev->portio_dir)
300 goto err_portio;
301 }
302 portio = kzalloc(sizeof(*portio), GFP_KERNEL);
303 if (!portio)
304 goto err_portio_kobj;
305 kobject_init(&portio->kobj, &portio_attr_type);
306 portio->port = port;
307 port->portio = portio;
308 ret = kobject_add(&portio->kobj, idev->portio_dir,
309 "port%d", pi);
310 if (ret)
311 goto err_portio_kobj;
312 ret = kobject_uevent(&portio->kobj, KOBJ_ADD);
313 if (ret)
314 goto err_portio;
315 }
316
317 return 0;
318
319err_portio:
320 pi--;
321err_portio_kobj:
322 for (; pi >= 0; pi--) {
323 port = &idev->info->port[pi];
324 portio = port->portio;
325 kobject_put(&portio->kobj);
326 }
327 kobject_put(idev->portio_dir);
328err_map:
329 mi--;
330err_map_kobj:
331 for (; mi >= 0; mi--) {
332 mem = &idev->info->mem[mi];
333 map = mem->map;
334 kobject_put(&map->kobj);
335 }
336 kobject_put(idev->map_dir);
337 dev_err(idev->dev, "error creating sysfs files (%d)\n", ret);
338 return ret;
339}
340
341static void uio_dev_del_attributes(struct uio_device *idev)
342{
343 int i;
344 struct uio_mem *mem;
345 struct uio_port *port;
346
347 for (i = 0; i < MAX_UIO_MAPS; i++) {
348 mem = &idev->info->mem[i];
349 if (mem->size == 0)
350 break;
351 kobject_put(&mem->map->kobj);
352 }
353 kobject_put(idev->map_dir);
354
355 for (i = 0; i < MAX_UIO_PORT_REGIONS; i++) {
356 port = &idev->info->port[i];
357 if (port->size == 0)
358 break;
359 kobject_put(&port->portio->kobj);
360 }
361 kobject_put(idev->portio_dir);
362}
363
364static int uio_get_minor(struct uio_device *idev)
365{
366 int retval = -ENOMEM;
367
368 mutex_lock(&minor_lock);
369 retval = idr_alloc(&uio_idr, idev, 0, UIO_MAX_DEVICES, GFP_KERNEL);
370 if (retval >= 0) {
371 idev->minor = retval;
372 retval = 0;
373 } else if (retval == -ENOSPC) {
374 dev_err(idev->dev, "too many uio devices\n");
375 retval = -EINVAL;
376 }
377 mutex_unlock(&minor_lock);
378 return retval;
379}
380
381static void uio_free_minor(struct uio_device *idev)
382{
383 mutex_lock(&minor_lock);
384 idr_remove(&uio_idr, idev->minor);
385 mutex_unlock(&minor_lock);
386}
387
388
389
390
391
392void uio_event_notify(struct uio_info *info)
393{
394 struct uio_device *idev = info->uio_dev;
395
396 atomic_inc(&idev->event);
397 wake_up_interruptible(&idev->wait);
398 kill_fasync(&idev->async_queue, SIGIO, POLL_IN);
399}
400EXPORT_SYMBOL_GPL(uio_event_notify);
401
402
403
404
405
406
407static irqreturn_t uio_interrupt(int irq, void *dev_id)
408{
409 struct uio_device *idev = (struct uio_device *)dev_id;
410 irqreturn_t ret = idev->info->handler(irq, idev->info);
411
412 if (ret == IRQ_HANDLED)
413 uio_event_notify(idev->info);
414
415 return ret;
416}
417
418struct uio_listener {
419 struct uio_device *dev;
420 s32 event_count;
421};
422
423static int uio_open(struct inode *inode, struct file *filep)
424{
425 struct uio_device *idev;
426 struct uio_listener *listener;
427 int ret = 0;
428
429 mutex_lock(&minor_lock);
430 idev = idr_find(&uio_idr, iminor(inode));
431 mutex_unlock(&minor_lock);
432 if (!idev) {
433 ret = -ENODEV;
434 goto out;
435 }
436
437 if (!try_module_get(idev->owner)) {
438 ret = -ENODEV;
439 goto out;
440 }
441
442 listener = kmalloc(sizeof(*listener), GFP_KERNEL);
443 if (!listener) {
444 ret = -ENOMEM;
445 goto err_alloc_listener;
446 }
447
448 listener->dev = idev;
449 listener->event_count = atomic_read(&idev->event);
450 filep->private_data = listener;
451
452 if (idev->info->open) {
453 ret = idev->info->open(idev->info, inode);
454 if (ret)
455 goto err_infoopen;
456 }
457 return 0;
458
459err_infoopen:
460 kfree(listener);
461
462err_alloc_listener:
463 module_put(idev->owner);
464
465out:
466 return ret;
467}
468
469static int uio_fasync(int fd, struct file *filep, int on)
470{
471 struct uio_listener *listener = filep->private_data;
472 struct uio_device *idev = listener->dev;
473
474 return fasync_helper(fd, filep, on, &idev->async_queue);
475}
476
477static int uio_release(struct inode *inode, struct file *filep)
478{
479 int ret = 0;
480 struct uio_listener *listener = filep->private_data;
481 struct uio_device *idev = listener->dev;
482
483 if (idev->info->release)
484 ret = idev->info->release(idev->info, inode);
485
486 module_put(idev->owner);
487 kfree(listener);
488 return ret;
489}
490
491static unsigned int uio_poll(struct file *filep, poll_table *wait)
492{
493 struct uio_listener *listener = filep->private_data;
494 struct uio_device *idev = listener->dev;
495
496 if (!idev->info->irq)
497 return -EIO;
498
499 poll_wait(filep, &idev->wait, wait);
500 if (listener->event_count != atomic_read(&idev->event))
501 return POLLIN | POLLRDNORM;
502 return 0;
503}
504
505static ssize_t uio_read(struct file *filep, char __user *buf,
506 size_t count, loff_t *ppos)
507{
508 struct uio_listener *listener = filep->private_data;
509 struct uio_device *idev = listener->dev;
510 DECLARE_WAITQUEUE(wait, current);
511 ssize_t retval;
512 s32 event_count;
513
514 if (!idev->info->irq)
515 return -EIO;
516
517 if (count != sizeof(s32))
518 return -EINVAL;
519
520 add_wait_queue(&idev->wait, &wait);
521
522 do {
523 set_current_state(TASK_INTERRUPTIBLE);
524
525 event_count = atomic_read(&idev->event);
526 if (event_count != listener->event_count) {
527 if (copy_to_user(buf, &event_count, count))
528 retval = -EFAULT;
529 else {
530 listener->event_count = event_count;
531 retval = count;
532 }
533 break;
534 }
535
536 if (filep->f_flags & O_NONBLOCK) {
537 retval = -EAGAIN;
538 break;
539 }
540
541 if (signal_pending(current)) {
542 retval = -ERESTARTSYS;
543 break;
544 }
545 schedule();
546 } while (1);
547
548 __set_current_state(TASK_RUNNING);
549 remove_wait_queue(&idev->wait, &wait);
550
551 return retval;
552}
553
554static ssize_t uio_write(struct file *filep, const char __user *buf,
555 size_t count, loff_t *ppos)
556{
557 struct uio_listener *listener = filep->private_data;
558 struct uio_device *idev = listener->dev;
559 ssize_t retval;
560 s32 irq_on;
561
562 if (!idev->info->irq)
563 return -EIO;
564
565 if (count != sizeof(s32))
566 return -EINVAL;
567
568 if (!idev->info->irqcontrol)
569 return -ENOSYS;
570
571 if (copy_from_user(&irq_on, buf, count))
572 return -EFAULT;
573
574 retval = idev->info->irqcontrol(idev->info, irq_on);
575
576 return retval ? retval : sizeof(s32);
577}
578
579static int uio_find_mem_index(struct vm_area_struct *vma)
580{
581 struct uio_device *idev = vma->vm_private_data;
582
583 if (vma->vm_pgoff < MAX_UIO_MAPS) {
584 if (idev->info->mem[vma->vm_pgoff].size == 0)
585 return -1;
586 return (int)vma->vm_pgoff;
587 }
588 return -1;
589}
590
591static int uio_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
592{
593 struct uio_device *idev = vma->vm_private_data;
594 struct page *page;
595 unsigned long offset;
596 void *addr;
597
598 int mi = uio_find_mem_index(vma);
599 if (mi < 0)
600 return VM_FAULT_SIGBUS;
601
602
603
604
605
606 offset = (vmf->pgoff - mi) << PAGE_SHIFT;
607
608 addr = (void *)(unsigned long)idev->info->mem[mi].addr + offset;
609 if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL)
610 page = virt_to_page(addr);
611 else
612 page = vmalloc_to_page(addr);
613 get_page(page);
614 vmf->page = page;
615 return 0;
616}
617
618static const struct vm_operations_struct uio_logical_vm_ops = {
619 .fault = uio_vma_fault,
620};
621
622static int uio_mmap_logical(struct vm_area_struct *vma)
623{
624 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
625 vma->vm_ops = &uio_logical_vm_ops;
626 return 0;
627}
628
629static const struct vm_operations_struct uio_physical_vm_ops = {
630#ifdef CONFIG_HAVE_IOREMAP_PROT
631 .access = generic_access_phys,
632#endif
633};
634
635static int uio_mmap_physical(struct vm_area_struct *vma)
636{
637 struct uio_device *idev = vma->vm_private_data;
638 int mi = uio_find_mem_index(vma);
639 struct uio_mem *mem;
640 if (mi < 0)
641 return -EINVAL;
642 mem = idev->info->mem + mi;
643
644 if (mem->addr & ~PAGE_MASK)
645 return -ENODEV;
646 if (vma->vm_end - vma->vm_start > mem->size)
647 return -EINVAL;
648
649 vma->vm_ops = &uio_physical_vm_ops;
650 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
651
652
653
654
655
656
657
658
659
660
661 return remap_pfn_range(vma,
662 vma->vm_start,
663 mem->addr >> PAGE_SHIFT,
664 vma->vm_end - vma->vm_start,
665 vma->vm_page_prot);
666}
667
668static int uio_mmap(struct file *filep, struct vm_area_struct *vma)
669{
670 struct uio_listener *listener = filep->private_data;
671 struct uio_device *idev = listener->dev;
672 int mi;
673 unsigned long requested_pages, actual_pages;
674 int ret = 0;
675
676 if (vma->vm_end < vma->vm_start)
677 return -EINVAL;
678
679 vma->vm_private_data = idev;
680
681 mi = uio_find_mem_index(vma);
682 if (mi < 0)
683 return -EINVAL;
684
685 requested_pages = vma_pages(vma);
686 actual_pages = ((idev->info->mem[mi].addr & ~PAGE_MASK)
687 + idev->info->mem[mi].size + PAGE_SIZE -1) >> PAGE_SHIFT;
688 if (requested_pages > actual_pages)
689 return -EINVAL;
690
691 if (idev->info->mmap) {
692 ret = idev->info->mmap(idev->info, vma);
693 return ret;
694 }
695
696 switch (idev->info->mem[mi].memtype) {
697 case UIO_MEM_PHYS:
698 return uio_mmap_physical(vma);
699 case UIO_MEM_LOGICAL:
700 case UIO_MEM_VIRTUAL:
701 return uio_mmap_logical(vma);
702 default:
703 return -EINVAL;
704 }
705}
706
707static const struct file_operations uio_fops = {
708 .owner = THIS_MODULE,
709 .open = uio_open,
710 .release = uio_release,
711 .read = uio_read,
712 .write = uio_write,
713 .mmap = uio_mmap,
714 .poll = uio_poll,
715 .fasync = uio_fasync,
716 .llseek = noop_llseek,
717};
718
719static int uio_major_init(void)
720{
721 static const char name[] = "uio";
722 struct cdev *cdev = NULL;
723 dev_t uio_dev = 0;
724 int result;
725
726 result = alloc_chrdev_region(&uio_dev, 0, UIO_MAX_DEVICES, name);
727 if (result)
728 goto out;
729
730 result = -ENOMEM;
731 cdev = cdev_alloc();
732 if (!cdev)
733 goto out_unregister;
734
735 cdev->owner = THIS_MODULE;
736 cdev->ops = &uio_fops;
737 kobject_set_name(&cdev->kobj, "%s", name);
738
739 result = cdev_add(cdev, uio_dev, UIO_MAX_DEVICES);
740 if (result)
741 goto out_put;
742
743 uio_major = MAJOR(uio_dev);
744 uio_cdev = cdev;
745 return 0;
746out_put:
747 kobject_put(&cdev->kobj);
748out_unregister:
749 unregister_chrdev_region(uio_dev, UIO_MAX_DEVICES);
750out:
751 return result;
752}
753
754static void uio_major_cleanup(void)
755{
756 unregister_chrdev_region(MKDEV(uio_major, 0), UIO_MAX_DEVICES);
757 cdev_del(uio_cdev);
758}
759
760static int init_uio_class(void)
761{
762 int ret;
763
764
765 ret = uio_major_init();
766 if (ret)
767 goto exit;
768
769 ret = class_register(&uio_class);
770 if (ret) {
771 printk(KERN_ERR "class_register failed for uio\n");
772 goto err_class_register;
773 }
774 return 0;
775
776err_class_register:
777 uio_major_cleanup();
778exit:
779 return ret;
780}
781
782static void release_uio_class(void)
783{
784 class_unregister(&uio_class);
785 uio_major_cleanup();
786}
787
788
789
790
791
792
793
794
795
796int __uio_register_device(struct module *owner,
797 struct device *parent,
798 struct uio_info *info)
799{
800 struct uio_device *idev;
801 int ret = 0;
802
803 if (!parent || !info || !info->name || !info->version)
804 return -EINVAL;
805
806 info->uio_dev = NULL;
807
808 idev = devm_kzalloc(parent, sizeof(*idev), GFP_KERNEL);
809 if (!idev) {
810 return -ENOMEM;
811 }
812
813 idev->owner = owner;
814 idev->info = info;
815 init_waitqueue_head(&idev->wait);
816 atomic_set(&idev->event, 0);
817
818 ret = uio_get_minor(idev);
819 if (ret)
820 return ret;
821
822 idev->dev = device_create(&uio_class, parent,
823 MKDEV(uio_major, idev->minor), idev,
824 "uio%d", idev->minor);
825 if (IS_ERR(idev->dev)) {
826 printk(KERN_ERR "UIO: device register failed\n");
827 ret = PTR_ERR(idev->dev);
828 goto err_device_create;
829 }
830
831 ret = uio_dev_add_attributes(idev);
832 if (ret)
833 goto err_uio_dev_add_attributes;
834
835 info->uio_dev = idev;
836
837 if (info->irq && (info->irq != UIO_IRQ_CUSTOM)) {
838
839
840
841
842
843
844
845
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);
860 return ret;
861}
862EXPORT_SYMBOL_GPL(__uio_register_device);
863
864
865
866
867
868
869void uio_unregister_device(struct uio_info *info)
870{
871 struct uio_device *idev;
872
873 if (!info || !info->uio_dev)
874 return;
875
876 idev = info->uio_dev;
877
878 uio_free_minor(idev);
879
880 uio_dev_del_attributes(idev);
881
882 free_irq(idev->info->irq, idev);
883
884 device_destroy(&uio_class, MKDEV(uio_major, idev->minor));
885
886 return;
887}
888EXPORT_SYMBOL_GPL(uio_unregister_device);
889
890static int __init uio_init(void)
891{
892 return init_uio_class();
893}
894
895static void __exit uio_exit(void)
896{
897 release_uio_class();
898}
899
900module_init(uio_init)
901module_exit(uio_exit)
902MODULE_LICENSE("GPL v2");
903