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/signal.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/* Protect idr accesses */
 37static DEFINE_MUTEX(minor_lock);
 38
 39/*
 40 * attributes
 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->offs);
 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,	/* need to NULL terminate the list of attributes */
 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/* UIO class infrastructure */
247static struct class uio_class = {
248	.name = "uio",
249	.dev_groups = uio_groups,
250};
251
252/*
253 * device functions
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				ret = -ENOMEM;
276				goto err_map;
277			}
278		}
279		map = kzalloc(sizeof(*map), GFP_KERNEL);
280		if (!map) {
281			ret = -ENOMEM;
282			goto err_map;
283		}
284		kobject_init(&map->kobj, &map_attr_type);
285		map->mem = mem;
286		mem->map = map;
287		ret = kobject_add(&map->kobj, idev->map_dir, "map%d", mi);
288		if (ret)
289			goto err_map_kobj;
290		ret = kobject_uevent(&map->kobj, KOBJ_ADD);
291		if (ret)
292			goto err_map_kobj;
293	}
294
295	for (pi = 0; pi < MAX_UIO_PORT_REGIONS; pi++) {
296		port = &idev->info->port[pi];
297		if (port->size == 0)
298			break;
299		if (!portio_found) {
300			portio_found = 1;
301			idev->portio_dir = kobject_create_and_add("portio",
302							&idev->dev->kobj);
303			if (!idev->portio_dir) {
304				ret = -ENOMEM;
305				goto err_portio;
306			}
307		}
308		portio = kzalloc(sizeof(*portio), GFP_KERNEL);
309		if (!portio) {
310			ret = -ENOMEM;
311			goto err_portio;
312		}
313		kobject_init(&portio->kobj, &portio_attr_type);
314		portio->port = port;
315		port->portio = portio;
316		ret = kobject_add(&portio->kobj, idev->portio_dir,
317							"port%d", pi);
318		if (ret)
319			goto err_portio_kobj;
320		ret = kobject_uevent(&portio->kobj, KOBJ_ADD);
321		if (ret)
322			goto err_portio_kobj;
323	}
324
325	return 0;
326
327err_portio:
328	pi--;
329err_portio_kobj:
330	for (; pi >= 0; pi--) {
331		port = &idev->info->port[pi];
332		portio = port->portio;
333		kobject_put(&portio->kobj);
334	}
335	kobject_put(idev->portio_dir);
336err_map:
337	mi--;
338err_map_kobj:
339	for (; mi >= 0; mi--) {
340		mem = &idev->info->mem[mi];
341		map = mem->map;
342		kobject_put(&map->kobj);
343	}
344	kobject_put(idev->map_dir);
345	dev_err(idev->dev, "error creating sysfs files (%d)\n", ret);
346	return ret;
347}
348
349static void uio_dev_del_attributes(struct uio_device *idev)
350{
351	int i;
352	struct uio_mem *mem;
353	struct uio_port *port;
354
355	for (i = 0; i < MAX_UIO_MAPS; i++) {
356		mem = &idev->info->mem[i];
357		if (mem->size == 0)
358			break;
359		kobject_put(&mem->map->kobj);
360	}
361	kobject_put(idev->map_dir);
362
363	for (i = 0; i < MAX_UIO_PORT_REGIONS; i++) {
364		port = &idev->info->port[i];
365		if (port->size == 0)
366			break;
367		kobject_put(&port->portio->kobj);
368	}
369	kobject_put(idev->portio_dir);
370}
371
372static int uio_get_minor(struct uio_device *idev)
373{
374	int retval = -ENOMEM;
375
376	mutex_lock(&minor_lock);
377	retval = idr_alloc(&uio_idr, idev, 0, UIO_MAX_DEVICES, GFP_KERNEL);
378	if (retval >= 0) {
379		idev->minor = retval;
380		retval = 0;
381	} else if (retval == -ENOSPC) {
382		dev_err(idev->dev, "too many uio devices\n");
383		retval = -EINVAL;
384	}
385	mutex_unlock(&minor_lock);
386	return retval;
387}
388
389static void uio_free_minor(struct uio_device *idev)
390{
391	mutex_lock(&minor_lock);
392	idr_remove(&uio_idr, idev->minor);
393	mutex_unlock(&minor_lock);
394}
395
396/**
397 * uio_event_notify - trigger an interrupt event
398 * @info: UIO device capabilities
399 */
400void uio_event_notify(struct uio_info *info)
401{
402	struct uio_device *idev = info->uio_dev;
403
404	atomic_inc(&idev->event);
405	wake_up_interruptible(&idev->wait);
406	kill_fasync(&idev->async_queue, SIGIO, POLL_IN);
407}
408EXPORT_SYMBOL_GPL(uio_event_notify);
409
410/**
411 * uio_interrupt - hardware interrupt handler
412 * @irq: IRQ number, can be UIO_IRQ_CYCLIC for cyclic timer
413 * @dev_id: Pointer to the devices uio_device structure
414 */
415static irqreturn_t uio_interrupt(int irq, void *dev_id)
416{
417	struct uio_device *idev = (struct uio_device *)dev_id;
418	irqreturn_t ret = idev->info->handler(irq, idev->info);
419
420	if (ret == IRQ_HANDLED)
421		uio_event_notify(idev->info);
422
423	return ret;
424}
425
426struct uio_listener {
427	struct uio_device *dev;
428	s32 event_count;
429};
430
431static int uio_open(struct inode *inode, struct file *filep)
432{
433	struct uio_device *idev;
434	struct uio_listener *listener;
435	int ret = 0;
436
437	mutex_lock(&minor_lock);
438	idev = idr_find(&uio_idr, iminor(inode));
439	mutex_unlock(&minor_lock);
440	if (!idev) {
441		ret = -ENODEV;
442		goto out;
443	}
444
445	if (!try_module_get(idev->owner)) {
446		ret = -ENODEV;
447		goto out;
448	}
449
450	listener = kmalloc(sizeof(*listener), GFP_KERNEL);
451	if (!listener) {
452		ret = -ENOMEM;
453		goto err_alloc_listener;
454	}
455
456	listener->dev = idev;
457	listener->event_count = atomic_read(&idev->event);
458	filep->private_data = listener;
459
460	if (idev->info->open) {
461		ret = idev->info->open(idev->info, inode);
462		if (ret)
463			goto err_infoopen;
464	}
465	return 0;
466
467err_infoopen:
468	kfree(listener);
469
470err_alloc_listener:
471	module_put(idev->owner);
472
473out:
474	return ret;
475}
476
477static int uio_fasync(int fd, struct file *filep, int on)
478{
479	struct uio_listener *listener = filep->private_data;
480	struct uio_device *idev = listener->dev;
481
482	return fasync_helper(fd, filep, on, &idev->async_queue);
483}
484
485static int uio_release(struct inode *inode, struct file *filep)
486{
487	int ret = 0;
488	struct uio_listener *listener = filep->private_data;
489	struct uio_device *idev = listener->dev;
490
491	if (idev->info->release)
492		ret = idev->info->release(idev->info, inode);
493
494	module_put(idev->owner);
495	kfree(listener);
496	return ret;
497}
498
499static __poll_t uio_poll(struct file *filep, poll_table *wait)
500{
501	struct uio_listener *listener = filep->private_data;
502	struct uio_device *idev = listener->dev;
503
504	if (!idev->info->irq)
505		return -EIO;
506
507	poll_wait(filep, &idev->wait, wait);
508	if (listener->event_count != atomic_read(&idev->event))
509		return EPOLLIN | EPOLLRDNORM;
510	return 0;
511}
512
513static ssize_t uio_read(struct file *filep, char __user *buf,
514			size_t count, loff_t *ppos)
515{
516	struct uio_listener *listener = filep->private_data;
517	struct uio_device *idev = listener->dev;
518	DECLARE_WAITQUEUE(wait, current);
519	ssize_t retval;
520	s32 event_count;
521
522	if (!idev->info->irq)
523		return -EIO;
524
525	if (count != sizeof(s32))
526		return -EINVAL;
527
528	add_wait_queue(&idev->wait, &wait);
529
530	do {
531		set_current_state(TASK_INTERRUPTIBLE);
532
533		event_count = atomic_read(&idev->event);
534		if (event_count != listener->event_count) {
535			__set_current_state(TASK_RUNNING);
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
563static 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
588static int uio_find_mem_index(struct vm_area_struct *vma)
589{
590	struct uio_device *idev = vma->vm_private_data;
591
592	if (vma->vm_pgoff < MAX_UIO_MAPS) {
593		if (idev->info->mem[vma->vm_pgoff].size == 0)
594			return -1;
595		return (int)vma->vm_pgoff;
596	}
597	return -1;
598}
599
600static int uio_vma_fault(struct vm_fault *vmf)
601{
602	struct uio_device *idev = vmf->vma->vm_private_data;
603	struct page *page;
604	unsigned long offset;
605	void *addr;
606
607	int mi = uio_find_mem_index(vmf->vma);
608	if (mi < 0)
609		return VM_FAULT_SIGBUS;
610
611	/*
612	 * We need to subtract mi because userspace uses offset = N*PAGE_SIZE
613	 * to use mem[N].
614	 */
615	offset = (vmf->pgoff - mi) << PAGE_SHIFT;
616
617	addr = (void *)(unsigned long)idev->info->mem[mi].addr + offset;
618	if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL)
619		page = virt_to_page(addr);
620	else
621		page = vmalloc_to_page(addr);
622	get_page(page);
623	vmf->page = page;
624	return 0;
625}
626
627static const struct vm_operations_struct uio_logical_vm_ops = {
628	.fault = uio_vma_fault,
629};
630
631static int uio_mmap_logical(struct vm_area_struct *vma)
632{
633	vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
634	vma->vm_ops = &uio_logical_vm_ops;
635	return 0;
636}
637
638static const struct vm_operations_struct uio_physical_vm_ops = {
639#ifdef CONFIG_HAVE_IOREMAP_PROT
640	.access = generic_access_phys,
641#endif
642};
643
644static int uio_mmap_physical(struct vm_area_struct *vma)
645{
646	struct uio_device *idev = vma->vm_private_data;
647	int mi = uio_find_mem_index(vma);
648	struct uio_mem *mem;
649	if (mi < 0)
650		return -EINVAL;
651	mem = idev->info->mem + mi;
652
653	if (mem->addr & ~PAGE_MASK)
654		return -ENODEV;
655	if (vma->vm_end - vma->vm_start > mem->size)
656		return -EINVAL;
657
658	vma->vm_ops = &uio_physical_vm_ops;
659	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
660
661	/*
662	 * We cannot use the vm_iomap_memory() helper here,
663	 * because vma->vm_pgoff is the map index we looked
664	 * up above in uio_find_mem_index(), rather than an
665	 * actual page offset into the mmap.
666	 *
667	 * So we just do the physical mmap without a page
668	 * offset.
669	 */
670	return remap_pfn_range(vma,
671			       vma->vm_start,
672			       mem->addr >> PAGE_SHIFT,
673			       vma->vm_end - vma->vm_start,
674			       vma->vm_page_prot);
675}
676
677static int uio_mmap(struct file *filep, struct vm_area_struct *vma)
678{
679	struct uio_listener *listener = filep->private_data;
680	struct uio_device *idev = listener->dev;
681	int mi;
682	unsigned long requested_pages, actual_pages;
683	int ret = 0;
684
685	if (vma->vm_end < vma->vm_start)
686		return -EINVAL;
687
688	vma->vm_private_data = idev;
689
690	mi = uio_find_mem_index(vma);
691	if (mi < 0)
692		return -EINVAL;
693
694	requested_pages = vma_pages(vma);
695	actual_pages = ((idev->info->mem[mi].addr & ~PAGE_MASK)
696			+ idev->info->mem[mi].size + PAGE_SIZE -1) >> PAGE_SHIFT;
697	if (requested_pages > actual_pages)
698		return -EINVAL;
699
700	if (idev->info->mmap) {
701		ret = idev->info->mmap(idev->info, vma);
702		return ret;
703	}
704
705	switch (idev->info->mem[mi].memtype) {
706		case UIO_MEM_PHYS:
707			return uio_mmap_physical(vma);
708		case UIO_MEM_LOGICAL:
709		case UIO_MEM_VIRTUAL:
710			return uio_mmap_logical(vma);
711		default:
712			return -EINVAL;
713	}
714}
715
716static const struct file_operations uio_fops = {
717	.owner		= THIS_MODULE,
718	.open		= uio_open,
719	.release	= uio_release,
720	.read		= uio_read,
721	.write		= uio_write,
722	.mmap		= uio_mmap,
723	.poll		= uio_poll,
724	.fasync		= uio_fasync,
725	.llseek		= noop_llseek,
726};
727
728static int uio_major_init(void)
729{
730	static const char name[] = "uio";
731	struct cdev *cdev = NULL;
732	dev_t uio_dev = 0;
733	int result;
734
735	result = alloc_chrdev_region(&uio_dev, 0, UIO_MAX_DEVICES, name);
736	if (result)
737		goto out;
738
739	result = -ENOMEM;
740	cdev = cdev_alloc();
741	if (!cdev)
742		goto out_unregister;
743
744	cdev->owner = THIS_MODULE;
745	cdev->ops = &uio_fops;
746	kobject_set_name(&cdev->kobj, "%s", name);
747
748	result = cdev_add(cdev, uio_dev, UIO_MAX_DEVICES);
749	if (result)
750		goto out_put;
751
752	uio_major = MAJOR(uio_dev);
753	uio_cdev = cdev;
754	return 0;
755out_put:
756	kobject_put(&cdev->kobj);
757out_unregister:
758	unregister_chrdev_region(uio_dev, UIO_MAX_DEVICES);
759out:
760	return result;
761}
762
763static void uio_major_cleanup(void)
764{
765	unregister_chrdev_region(MKDEV(uio_major, 0), UIO_MAX_DEVICES);
766	cdev_del(uio_cdev);
767}
768
769static int init_uio_class(void)
770{
771	int ret;
772
773	/* This is the first time in here, set everything up properly */
774	ret = uio_major_init();
775	if (ret)
776		goto exit;
777
778	ret = class_register(&uio_class);
779	if (ret) {
780		printk(KERN_ERR "class_register failed for uio\n");
781		goto err_class_register;
782	}
783	return 0;
784
785err_class_register:
786	uio_major_cleanup();
787exit:
788	return ret;
789}
790
791static void release_uio_class(void)
792{
793	class_unregister(&uio_class);
794	uio_major_cleanup();
795}
796
797/**
798 * uio_register_device - register a new userspace IO device
799 * @owner:	module that creates the new device
800 * @parent:	parent device
801 * @info:	UIO device capabilities
802 *
803 * returns zero on success or a negative error code.
804 */
805int __uio_register_device(struct module *owner,
806			  struct device *parent,
807			  struct uio_info *info)
808{
809	struct uio_device *idev;
810	int ret = 0;
811
812	if (!parent || !info || !info->name || !info->version)
813		return -EINVAL;
814
815	info->uio_dev = NULL;
816
817	idev = devm_kzalloc(parent, sizeof(*idev), GFP_KERNEL);
818	if (!idev) {
819		return -ENOMEM;
820	}
821
822	idev->owner = owner;
823	idev->info = info;
824	init_waitqueue_head(&idev->wait);
825	atomic_set(&idev->event, 0);
826
827	ret = uio_get_minor(idev);
828	if (ret)
829		return ret;
830
831	idev->dev = device_create(&uio_class, parent,
832				  MKDEV(uio_major, idev->minor), idev,
833				  "uio%d", idev->minor);
834	if (IS_ERR(idev->dev)) {
835		printk(KERN_ERR "UIO: device register failed\n");
836		ret = PTR_ERR(idev->dev);
837		goto err_device_create;
838	}
839
840	ret = uio_dev_add_attributes(idev);
841	if (ret)
842		goto err_uio_dev_add_attributes;
843
844	info->uio_dev = idev;
845
846	if (info->irq && (info->irq != UIO_IRQ_CUSTOM)) {
847		/*
848		 * Note that we deliberately don't use devm_request_irq
849		 * here. The parent module can unregister the UIO device
850		 * and call pci_disable_msi, which requires that this
851		 * irq has been freed. However, the device may have open
852		 * FDs at the time of unregister and therefore may not be
853		 * freed until they are released.
854		 */
855		ret = request_irq(info->irq, uio_interrupt,
856				  info->irq_flags, info->name, idev);
857		if (ret)
858			goto err_request_irq;
859	}
860
861	return 0;
862
863err_request_irq:
864	uio_dev_del_attributes(idev);
865err_uio_dev_add_attributes:
866	device_destroy(&uio_class, MKDEV(uio_major, idev->minor));
867err_device_create:
868	uio_free_minor(idev);
869	return ret;
870}
871EXPORT_SYMBOL_GPL(__uio_register_device);
872
873/**
874 * uio_unregister_device - unregister a industrial IO device
875 * @info:	UIO device capabilities
876 *
877 */
878void uio_unregister_device(struct uio_info *info)
879{
880	struct uio_device *idev;
881
882	if (!info || !info->uio_dev)
883		return;
884
885	idev = info->uio_dev;
886
887	uio_free_minor(idev);
888
889	uio_dev_del_attributes(idev);
890
891	if (info->irq && info->irq != UIO_IRQ_CUSTOM)
892		free_irq(info->irq, idev);
893
894	device_destroy(&uio_class, MKDEV(uio_major, idev->minor));
895
896	return;
897}
898EXPORT_SYMBOL_GPL(uio_unregister_device);
899
900static int __init uio_init(void)
901{
902	return init_uio_class();
903}
904
905static void __exit uio_exit(void)
906{
907	release_uio_class();
908	idr_destroy(&uio_idr);
909}
910
911module_init(uio_init)
912module_exit(uio_exit)
913MODULE_LICENSE("GPL v2");