Commit | Line | Data |
---|---|---|
beafc54c HK |
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@linutronix.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/mm.h> | |
21 | #include <linux/idr.h> | |
22 | #include <linux/string.h> | |
23 | #include <linux/kobject.h> | |
24 | #include <linux/uio_driver.h> | |
25 | ||
26 | #define UIO_MAX_DEVICES 255 | |
27 | ||
28 | struct uio_device { | |
29 | struct module *owner; | |
30 | struct device *dev; | |
31 | int minor; | |
32 | atomic_t event; | |
33 | struct fasync_struct *async_queue; | |
34 | wait_queue_head_t wait; | |
35 | int vma_count; | |
36 | struct uio_info *info; | |
81e7c6a6 | 37 | struct kobject *map_dir; |
beafc54c HK |
38 | }; |
39 | ||
40 | static int uio_major; | |
41 | static DEFINE_IDR(uio_idr); | |
4f014691 | 42 | static const struct file_operations uio_fops; |
beafc54c HK |
43 | |
44 | /* UIO class infrastructure */ | |
45 | static struct uio_class { | |
46 | struct kref kref; | |
47 | struct class *class; | |
48 | } *uio_class; | |
49 | ||
50 | /* | |
51 | * attributes | |
52 | */ | |
53 | ||
81e7c6a6 GKH |
54 | struct uio_map { |
55 | struct kobject kobj; | |
56 | struct uio_mem *mem; | |
beafc54c | 57 | }; |
81e7c6a6 | 58 | #define to_map(map) container_of(map, struct uio_map, kobj) |
beafc54c | 59 | |
4f808bcd | 60 | static ssize_t map_addr_show(struct uio_mem *mem, char *buf) |
beafc54c | 61 | { |
4f808bcd BP |
62 | return sprintf(buf, "0x%lx\n", mem->addr); |
63 | } | |
beafc54c | 64 | |
4f808bcd BP |
65 | static ssize_t map_size_show(struct uio_mem *mem, char *buf) |
66 | { | |
67 | return sprintf(buf, "0x%lx\n", mem->size); | |
beafc54c HK |
68 | } |
69 | ||
4f808bcd BP |
70 | struct uio_sysfs_entry { |
71 | struct attribute attr; | |
72 | ssize_t (*show)(struct uio_mem *, char *); | |
73 | ssize_t (*store)(struct uio_mem *, const char *, size_t); | |
74 | }; | |
75 | ||
76 | static struct uio_sysfs_entry addr_attribute = | |
77 | __ATTR(addr, S_IRUGO, map_addr_show, NULL); | |
78 | static struct uio_sysfs_entry size_attribute = | |
79 | __ATTR(size, S_IRUGO, map_size_show, NULL); | |
beafc54c | 80 | |
81e7c6a6 | 81 | static struct attribute *attrs[] = { |
4f808bcd | 82 | &addr_attribute.attr, |
81e7c6a6 GKH |
83 | &size_attribute.attr, |
84 | NULL, /* need to NULL terminate the list of attributes */ | |
beafc54c HK |
85 | }; |
86 | ||
81e7c6a6 GKH |
87 | static void map_release(struct kobject *kobj) |
88 | { | |
89 | struct uio_map *map = to_map(kobj); | |
90 | kfree(map); | |
91 | } | |
92 | ||
4f808bcd BP |
93 | static ssize_t map_type_show(struct kobject *kobj, struct attribute *attr, |
94 | char *buf) | |
95 | { | |
96 | struct uio_map *map = to_map(kobj); | |
97 | struct uio_mem *mem = map->mem; | |
98 | struct uio_sysfs_entry *entry; | |
99 | ||
100 | entry = container_of(attr, struct uio_sysfs_entry, attr); | |
101 | ||
102 | if (!entry->show) | |
103 | return -EIO; | |
104 | ||
105 | return entry->show(mem, buf); | |
106 | } | |
107 | ||
108 | static struct sysfs_ops uio_sysfs_ops = { | |
109 | .show = map_type_show, | |
110 | }; | |
111 | ||
beafc54c | 112 | static struct kobj_type map_attr_type = { |
81e7c6a6 | 113 | .release = map_release, |
4f808bcd | 114 | .sysfs_ops = &uio_sysfs_ops, |
81e7c6a6 | 115 | .default_attrs = attrs, |
beafc54c HK |
116 | }; |
117 | ||
118 | static ssize_t show_name(struct device *dev, | |
119 | struct device_attribute *attr, char *buf) | |
120 | { | |
121 | struct uio_device *idev = dev_get_drvdata(dev); | |
122 | if (idev) | |
123 | return sprintf(buf, "%s\n", idev->info->name); | |
124 | else | |
125 | return -ENODEV; | |
126 | } | |
127 | static DEVICE_ATTR(name, S_IRUGO, show_name, NULL); | |
128 | ||
129 | static ssize_t show_version(struct device *dev, | |
130 | struct device_attribute *attr, char *buf) | |
131 | { | |
132 | struct uio_device *idev = dev_get_drvdata(dev); | |
133 | if (idev) | |
134 | return sprintf(buf, "%s\n", idev->info->version); | |
135 | else | |
136 | return -ENODEV; | |
137 | } | |
138 | static DEVICE_ATTR(version, S_IRUGO, show_version, NULL); | |
139 | ||
140 | static ssize_t show_event(struct device *dev, | |
141 | struct device_attribute *attr, char *buf) | |
142 | { | |
143 | struct uio_device *idev = dev_get_drvdata(dev); | |
144 | if (idev) | |
145 | return sprintf(buf, "%u\n", | |
146 | (unsigned int)atomic_read(&idev->event)); | |
147 | else | |
148 | return -ENODEV; | |
149 | } | |
150 | static DEVICE_ATTR(event, S_IRUGO, show_event, NULL); | |
151 | ||
152 | static struct attribute *uio_attrs[] = { | |
153 | &dev_attr_name.attr, | |
154 | &dev_attr_version.attr, | |
155 | &dev_attr_event.attr, | |
156 | NULL, | |
157 | }; | |
158 | ||
159 | static struct attribute_group uio_attr_grp = { | |
160 | .attrs = uio_attrs, | |
161 | }; | |
162 | ||
163 | /* | |
164 | * device functions | |
165 | */ | |
166 | static int uio_dev_add_attributes(struct uio_device *idev) | |
167 | { | |
168 | int ret; | |
169 | int mi; | |
170 | int map_found = 0; | |
171 | struct uio_mem *mem; | |
81e7c6a6 | 172 | struct uio_map *map; |
beafc54c HK |
173 | |
174 | ret = sysfs_create_group(&idev->dev->kobj, &uio_attr_grp); | |
175 | if (ret) | |
176 | goto err_group; | |
177 | ||
178 | for (mi = 0; mi < MAX_UIO_MAPS; mi++) { | |
179 | mem = &idev->info->mem[mi]; | |
180 | if (mem->size == 0) | |
181 | break; | |
182 | if (!map_found) { | |
183 | map_found = 1; | |
81e7c6a6 GKH |
184 | idev->map_dir = kobject_create_and_add("maps", |
185 | &idev->dev->kobj); | |
186 | if (!idev->map_dir) | |
187 | goto err; | |
beafc54c | 188 | } |
81e7c6a6 GKH |
189 | map = kzalloc(sizeof(*map), GFP_KERNEL); |
190 | if (!map) | |
191 | goto err; | |
f9cb074b | 192 | kobject_init(&map->kobj, &map_attr_type); |
81e7c6a6 GKH |
193 | map->mem = mem; |
194 | mem->map = map; | |
b2d6db58 | 195 | ret = kobject_add(&map->kobj, idev->map_dir, "map%d", mi); |
81e7c6a6 GKH |
196 | if (ret) |
197 | goto err; | |
198 | ret = kobject_uevent(&map->kobj, KOBJ_ADD); | |
beafc54c | 199 | if (ret) |
81e7c6a6 | 200 | goto err; |
beafc54c HK |
201 | } |
202 | ||
203 | return 0; | |
204 | ||
81e7c6a6 | 205 | err: |
beafc54c HK |
206 | for (mi--; mi>=0; mi--) { |
207 | mem = &idev->info->mem[mi]; | |
81e7c6a6 | 208 | map = mem->map; |
c10997f6 | 209 | kobject_put(&map->kobj); |
beafc54c | 210 | } |
c10997f6 | 211 | kobject_put(idev->map_dir); |
beafc54c HK |
212 | sysfs_remove_group(&idev->dev->kobj, &uio_attr_grp); |
213 | err_group: | |
214 | dev_err(idev->dev, "error creating sysfs files (%d)\n", ret); | |
215 | return ret; | |
216 | } | |
217 | ||
218 | static void uio_dev_del_attributes(struct uio_device *idev) | |
219 | { | |
220 | int mi; | |
221 | struct uio_mem *mem; | |
222 | for (mi = 0; mi < MAX_UIO_MAPS; mi++) { | |
223 | mem = &idev->info->mem[mi]; | |
224 | if (mem->size == 0) | |
225 | break; | |
c10997f6 | 226 | kobject_put(&mem->map->kobj); |
beafc54c | 227 | } |
c10997f6 | 228 | kobject_put(idev->map_dir); |
beafc54c HK |
229 | sysfs_remove_group(&idev->dev->kobj, &uio_attr_grp); |
230 | } | |
231 | ||
232 | static int uio_get_minor(struct uio_device *idev) | |
233 | { | |
234 | static DEFINE_MUTEX(minor_lock); | |
235 | int retval = -ENOMEM; | |
236 | int id; | |
237 | ||
238 | mutex_lock(&minor_lock); | |
239 | if (idr_pre_get(&uio_idr, GFP_KERNEL) == 0) | |
240 | goto exit; | |
241 | ||
242 | retval = idr_get_new(&uio_idr, idev, &id); | |
243 | if (retval < 0) { | |
244 | if (retval == -EAGAIN) | |
245 | retval = -ENOMEM; | |
246 | goto exit; | |
247 | } | |
248 | idev->minor = id & MAX_ID_MASK; | |
249 | exit: | |
250 | mutex_unlock(&minor_lock); | |
251 | return retval; | |
252 | } | |
253 | ||
254 | static void uio_free_minor(struct uio_device *idev) | |
255 | { | |
256 | idr_remove(&uio_idr, idev->minor); | |
257 | } | |
258 | ||
259 | /** | |
260 | * uio_event_notify - trigger an interrupt event | |
261 | * @info: UIO device capabilities | |
262 | */ | |
263 | void uio_event_notify(struct uio_info *info) | |
264 | { | |
265 | struct uio_device *idev = info->uio_dev; | |
266 | ||
267 | atomic_inc(&idev->event); | |
268 | wake_up_interruptible(&idev->wait); | |
269 | kill_fasync(&idev->async_queue, SIGIO, POLL_IN); | |
270 | } | |
271 | EXPORT_SYMBOL_GPL(uio_event_notify); | |
272 | ||
273 | /** | |
274 | * uio_interrupt - hardware interrupt handler | |
275 | * @irq: IRQ number, can be UIO_IRQ_CYCLIC for cyclic timer | |
276 | * @dev_id: Pointer to the devices uio_device structure | |
277 | */ | |
278 | static irqreturn_t uio_interrupt(int irq, void *dev_id) | |
279 | { | |
280 | struct uio_device *idev = (struct uio_device *)dev_id; | |
281 | irqreturn_t ret = idev->info->handler(irq, idev->info); | |
282 | ||
283 | if (ret == IRQ_HANDLED) | |
284 | uio_event_notify(idev->info); | |
285 | ||
286 | return ret; | |
287 | } | |
288 | ||
289 | struct uio_listener { | |
290 | struct uio_device *dev; | |
291 | s32 event_count; | |
292 | }; | |
293 | ||
294 | static int uio_open(struct inode *inode, struct file *filep) | |
295 | { | |
296 | struct uio_device *idev; | |
297 | struct uio_listener *listener; | |
298 | int ret = 0; | |
299 | ||
300 | idev = idr_find(&uio_idr, iminor(inode)); | |
301 | if (!idev) | |
302 | return -ENODEV; | |
303 | ||
610ad506 UKK |
304 | if (!try_module_get(idev->owner)) |
305 | return -ENODEV; | |
306 | ||
beafc54c | 307 | listener = kmalloc(sizeof(*listener), GFP_KERNEL); |
610ad506 UKK |
308 | if (!listener) { |
309 | ret = -ENOMEM; | |
310 | goto err_alloc_listener; | |
311 | } | |
beafc54c HK |
312 | |
313 | listener->dev = idev; | |
314 | listener->event_count = atomic_read(&idev->event); | |
315 | filep->private_data = listener; | |
316 | ||
317 | if (idev->info->open) { | |
beafc54c | 318 | ret = idev->info->open(idev->info, inode); |
610ad506 UKK |
319 | if (ret) |
320 | goto err_infoopen; | |
beafc54c HK |
321 | } |
322 | ||
610ad506 UKK |
323 | return 0; |
324 | ||
325 | err_infoopen: | |
326 | ||
327 | kfree(listener); | |
328 | err_alloc_listener: | |
329 | ||
330 | module_put(idev->owner); | |
beafc54c HK |
331 | |
332 | return ret; | |
333 | } | |
334 | ||
335 | static int uio_fasync(int fd, struct file *filep, int on) | |
336 | { | |
337 | struct uio_listener *listener = filep->private_data; | |
338 | struct uio_device *idev = listener->dev; | |
339 | ||
340 | return fasync_helper(fd, filep, on, &idev->async_queue); | |
341 | } | |
342 | ||
343 | static int uio_release(struct inode *inode, struct file *filep) | |
344 | { | |
345 | int ret = 0; | |
346 | struct uio_listener *listener = filep->private_data; | |
347 | struct uio_device *idev = listener->dev; | |
348 | ||
610ad506 | 349 | if (idev->info->release) |
beafc54c | 350 | ret = idev->info->release(idev->info, inode); |
610ad506 UKK |
351 | |
352 | module_put(idev->owner); | |
353 | ||
beafc54c HK |
354 | if (filep->f_flags & FASYNC) |
355 | ret = uio_fasync(-1, filep, 0); | |
356 | kfree(listener); | |
357 | return ret; | |
358 | } | |
359 | ||
360 | static unsigned int uio_poll(struct file *filep, poll_table *wait) | |
361 | { | |
362 | struct uio_listener *listener = filep->private_data; | |
363 | struct uio_device *idev = listener->dev; | |
364 | ||
365 | if (idev->info->irq == UIO_IRQ_NONE) | |
366 | return -EIO; | |
367 | ||
368 | poll_wait(filep, &idev->wait, wait); | |
369 | if (listener->event_count != atomic_read(&idev->event)) | |
370 | return POLLIN | POLLRDNORM; | |
371 | return 0; | |
372 | } | |
373 | ||
374 | static ssize_t uio_read(struct file *filep, char __user *buf, | |
375 | size_t count, loff_t *ppos) | |
376 | { | |
377 | struct uio_listener *listener = filep->private_data; | |
378 | struct uio_device *idev = listener->dev; | |
379 | DECLARE_WAITQUEUE(wait, current); | |
380 | ssize_t retval; | |
381 | s32 event_count; | |
382 | ||
383 | if (idev->info->irq == UIO_IRQ_NONE) | |
384 | return -EIO; | |
385 | ||
386 | if (count != sizeof(s32)) | |
387 | return -EINVAL; | |
388 | ||
389 | add_wait_queue(&idev->wait, &wait); | |
390 | ||
391 | do { | |
392 | set_current_state(TASK_INTERRUPTIBLE); | |
393 | ||
394 | event_count = atomic_read(&idev->event); | |
395 | if (event_count != listener->event_count) { | |
396 | if (copy_to_user(buf, &event_count, count)) | |
397 | retval = -EFAULT; | |
398 | else { | |
399 | listener->event_count = event_count; | |
400 | retval = count; | |
401 | } | |
402 | break; | |
403 | } | |
404 | ||
405 | if (filep->f_flags & O_NONBLOCK) { | |
406 | retval = -EAGAIN; | |
407 | break; | |
408 | } | |
409 | ||
410 | if (signal_pending(current)) { | |
411 | retval = -ERESTARTSYS; | |
412 | break; | |
413 | } | |
414 | schedule(); | |
415 | } while (1); | |
416 | ||
417 | __set_current_state(TASK_RUNNING); | |
418 | remove_wait_queue(&idev->wait, &wait); | |
419 | ||
420 | return retval; | |
421 | } | |
422 | ||
423 | static int uio_find_mem_index(struct vm_area_struct *vma) | |
424 | { | |
425 | int mi; | |
426 | struct uio_device *idev = vma->vm_private_data; | |
427 | ||
428 | for (mi = 0; mi < MAX_UIO_MAPS; mi++) { | |
429 | if (idev->info->mem[mi].size == 0) | |
430 | return -1; | |
431 | if (vma->vm_pgoff == mi) | |
432 | return mi; | |
433 | } | |
434 | return -1; | |
435 | } | |
436 | ||
437 | static void uio_vma_open(struct vm_area_struct *vma) | |
438 | { | |
439 | struct uio_device *idev = vma->vm_private_data; | |
440 | idev->vma_count++; | |
441 | } | |
442 | ||
443 | static void uio_vma_close(struct vm_area_struct *vma) | |
444 | { | |
445 | struct uio_device *idev = vma->vm_private_data; | |
446 | idev->vma_count--; | |
447 | } | |
448 | ||
a18b630d | 449 | static int uio_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
beafc54c HK |
450 | { |
451 | struct uio_device *idev = vma->vm_private_data; | |
a18b630d | 452 | struct page *page; |
beafc54c HK |
453 | |
454 | int mi = uio_find_mem_index(vma); | |
455 | if (mi < 0) | |
a18b630d | 456 | return VM_FAULT_SIGBUS; |
beafc54c HK |
457 | |
458 | if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL) | |
459 | page = virt_to_page(idev->info->mem[mi].addr); | |
460 | else | |
461 | page = vmalloc_to_page((void*)idev->info->mem[mi].addr); | |
462 | get_page(page); | |
a18b630d NP |
463 | vmf->page = page; |
464 | return 0; | |
beafc54c HK |
465 | } |
466 | ||
467 | static struct vm_operations_struct uio_vm_ops = { | |
468 | .open = uio_vma_open, | |
469 | .close = uio_vma_close, | |
a18b630d | 470 | .fault = uio_vma_fault, |
beafc54c HK |
471 | }; |
472 | ||
473 | static int uio_mmap_physical(struct vm_area_struct *vma) | |
474 | { | |
475 | struct uio_device *idev = vma->vm_private_data; | |
476 | int mi = uio_find_mem_index(vma); | |
477 | if (mi < 0) | |
478 | return -EINVAL; | |
479 | ||
480 | vma->vm_flags |= VM_IO | VM_RESERVED; | |
c9698d6b JSC |
481 | |
482 | vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); | |
beafc54c HK |
483 | |
484 | return remap_pfn_range(vma, | |
485 | vma->vm_start, | |
486 | idev->info->mem[mi].addr >> PAGE_SHIFT, | |
487 | vma->vm_end - vma->vm_start, | |
488 | vma->vm_page_prot); | |
489 | } | |
490 | ||
491 | static int uio_mmap_logical(struct vm_area_struct *vma) | |
492 | { | |
493 | vma->vm_flags |= VM_RESERVED; | |
494 | vma->vm_ops = &uio_vm_ops; | |
495 | uio_vma_open(vma); | |
496 | return 0; | |
497 | } | |
498 | ||
499 | static int uio_mmap(struct file *filep, struct vm_area_struct *vma) | |
500 | { | |
501 | struct uio_listener *listener = filep->private_data; | |
502 | struct uio_device *idev = listener->dev; | |
503 | int mi; | |
504 | unsigned long requested_pages, actual_pages; | |
505 | int ret = 0; | |
506 | ||
507 | if (vma->vm_end < vma->vm_start) | |
508 | return -EINVAL; | |
509 | ||
510 | vma->vm_private_data = idev; | |
511 | ||
512 | mi = uio_find_mem_index(vma); | |
513 | if (mi < 0) | |
514 | return -EINVAL; | |
515 | ||
516 | requested_pages = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; | |
517 | actual_pages = (idev->info->mem[mi].size + PAGE_SIZE -1) >> PAGE_SHIFT; | |
518 | if (requested_pages > actual_pages) | |
519 | return -EINVAL; | |
520 | ||
521 | if (idev->info->mmap) { | |
beafc54c | 522 | ret = idev->info->mmap(idev->info, vma); |
beafc54c HK |
523 | return ret; |
524 | } | |
525 | ||
526 | switch (idev->info->mem[mi].memtype) { | |
527 | case UIO_MEM_PHYS: | |
528 | return uio_mmap_physical(vma); | |
529 | case UIO_MEM_LOGICAL: | |
530 | case UIO_MEM_VIRTUAL: | |
531 | return uio_mmap_logical(vma); | |
532 | default: | |
533 | return -EINVAL; | |
534 | } | |
535 | } | |
536 | ||
4f014691 | 537 | static const struct file_operations uio_fops = { |
beafc54c HK |
538 | .owner = THIS_MODULE, |
539 | .open = uio_open, | |
540 | .release = uio_release, | |
541 | .read = uio_read, | |
542 | .mmap = uio_mmap, | |
543 | .poll = uio_poll, | |
544 | .fasync = uio_fasync, | |
545 | }; | |
546 | ||
547 | static int uio_major_init(void) | |
548 | { | |
549 | uio_major = register_chrdev(0, "uio", &uio_fops); | |
550 | if (uio_major < 0) | |
551 | return uio_major; | |
552 | return 0; | |
553 | } | |
554 | ||
555 | static void uio_major_cleanup(void) | |
556 | { | |
557 | unregister_chrdev(uio_major, "uio"); | |
558 | } | |
559 | ||
560 | static int init_uio_class(void) | |
561 | { | |
562 | int ret = 0; | |
563 | ||
564 | if (uio_class != NULL) { | |
565 | kref_get(&uio_class->kref); | |
566 | goto exit; | |
567 | } | |
568 | ||
569 | /* This is the first time in here, set everything up properly */ | |
570 | ret = uio_major_init(); | |
571 | if (ret) | |
572 | goto exit; | |
573 | ||
574 | uio_class = kzalloc(sizeof(*uio_class), GFP_KERNEL); | |
575 | if (!uio_class) { | |
576 | ret = -ENOMEM; | |
577 | goto err_kzalloc; | |
578 | } | |
579 | ||
580 | kref_init(&uio_class->kref); | |
581 | uio_class->class = class_create(THIS_MODULE, "uio"); | |
582 | if (IS_ERR(uio_class->class)) { | |
583 | ret = IS_ERR(uio_class->class); | |
584 | printk(KERN_ERR "class_create failed for uio\n"); | |
585 | goto err_class_create; | |
586 | } | |
587 | return 0; | |
588 | ||
589 | err_class_create: | |
590 | kfree(uio_class); | |
591 | uio_class = NULL; | |
592 | err_kzalloc: | |
593 | uio_major_cleanup(); | |
594 | exit: | |
595 | return ret; | |
596 | } | |
597 | ||
598 | static void release_uio_class(struct kref *kref) | |
599 | { | |
600 | /* Ok, we cheat as we know we only have one uio_class */ | |
601 | class_destroy(uio_class->class); | |
602 | kfree(uio_class); | |
603 | uio_major_cleanup(); | |
604 | uio_class = NULL; | |
605 | } | |
606 | ||
607 | static void uio_class_destroy(void) | |
608 | { | |
609 | if (uio_class) | |
610 | kref_put(&uio_class->kref, release_uio_class); | |
611 | } | |
612 | ||
613 | /** | |
614 | * uio_register_device - register a new userspace IO device | |
615 | * @owner: module that creates the new device | |
616 | * @parent: parent device | |
617 | * @info: UIO device capabilities | |
618 | * | |
619 | * returns zero on success or a negative error code. | |
620 | */ | |
621 | int __uio_register_device(struct module *owner, | |
622 | struct device *parent, | |
623 | struct uio_info *info) | |
624 | { | |
625 | struct uio_device *idev; | |
626 | int ret = 0; | |
627 | ||
628 | if (!parent || !info || !info->name || !info->version) | |
629 | return -EINVAL; | |
630 | ||
631 | info->uio_dev = NULL; | |
632 | ||
633 | ret = init_uio_class(); | |
634 | if (ret) | |
635 | return ret; | |
636 | ||
637 | idev = kzalloc(sizeof(*idev), GFP_KERNEL); | |
638 | if (!idev) { | |
639 | ret = -ENOMEM; | |
640 | goto err_kzalloc; | |
641 | } | |
642 | ||
643 | idev->owner = owner; | |
644 | idev->info = info; | |
645 | init_waitqueue_head(&idev->wait); | |
646 | atomic_set(&idev->event, 0); | |
647 | ||
648 | ret = uio_get_minor(idev); | |
649 | if (ret) | |
650 | goto err_get_minor; | |
651 | ||
652 | idev->dev = device_create(uio_class->class, parent, | |
653 | MKDEV(uio_major, idev->minor), | |
654 | "uio%d", idev->minor); | |
655 | if (IS_ERR(idev->dev)) { | |
656 | printk(KERN_ERR "UIO: device register failed\n"); | |
657 | ret = PTR_ERR(idev->dev); | |
658 | goto err_device_create; | |
659 | } | |
660 | dev_set_drvdata(idev->dev, idev); | |
661 | ||
662 | ret = uio_dev_add_attributes(idev); | |
663 | if (ret) | |
664 | goto err_uio_dev_add_attributes; | |
665 | ||
666 | info->uio_dev = idev; | |
667 | ||
668 | if (idev->info->irq >= 0) { | |
669 | ret = request_irq(idev->info->irq, uio_interrupt, | |
670 | idev->info->irq_flags, idev->info->name, idev); | |
671 | if (ret) | |
672 | goto err_request_irq; | |
673 | } | |
674 | ||
675 | return 0; | |
676 | ||
677 | err_request_irq: | |
678 | uio_dev_del_attributes(idev); | |
679 | err_uio_dev_add_attributes: | |
680 | device_destroy(uio_class->class, MKDEV(uio_major, idev->minor)); | |
681 | err_device_create: | |
682 | uio_free_minor(idev); | |
683 | err_get_minor: | |
684 | kfree(idev); | |
685 | err_kzalloc: | |
686 | uio_class_destroy(); | |
687 | return ret; | |
688 | } | |
689 | EXPORT_SYMBOL_GPL(__uio_register_device); | |
690 | ||
691 | /** | |
692 | * uio_unregister_device - unregister a industrial IO device | |
693 | * @info: UIO device capabilities | |
694 | * | |
695 | */ | |
696 | void uio_unregister_device(struct uio_info *info) | |
697 | { | |
698 | struct uio_device *idev; | |
699 | ||
700 | if (!info || !info->uio_dev) | |
701 | return; | |
702 | ||
703 | idev = info->uio_dev; | |
704 | ||
705 | uio_free_minor(idev); | |
706 | ||
707 | if (info->irq >= 0) | |
708 | free_irq(info->irq, idev); | |
709 | ||
710 | uio_dev_del_attributes(idev); | |
711 | ||
712 | dev_set_drvdata(idev->dev, NULL); | |
713 | device_destroy(uio_class->class, MKDEV(uio_major, idev->minor)); | |
714 | kfree(idev); | |
715 | uio_class_destroy(); | |
716 | ||
717 | return; | |
718 | } | |
719 | EXPORT_SYMBOL_GPL(uio_unregister_device); | |
720 | ||
721 | static int __init uio_init(void) | |
722 | { | |
723 | return 0; | |
724 | } | |
725 | ||
726 | static void __exit uio_exit(void) | |
727 | { | |
728 | } | |
729 | ||
730 | module_init(uio_init) | |
731 | module_exit(uio_exit) | |
732 | MODULE_LICENSE("GPL v2"); |