Commit | Line | Data |
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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 | ||
e2b39df1 HK |
70 | static ssize_t map_offset_show(struct uio_mem *mem, char *buf) |
71 | { | |
72 | return sprintf(buf, "0x%lx\n", mem->addr & ~PAGE_MASK); | |
73 | } | |
74 | ||
4f808bcd BP |
75 | struct uio_sysfs_entry { |
76 | struct attribute attr; | |
77 | ssize_t (*show)(struct uio_mem *, char *); | |
78 | ssize_t (*store)(struct uio_mem *, const char *, size_t); | |
79 | }; | |
80 | ||
81 | static struct uio_sysfs_entry addr_attribute = | |
82 | __ATTR(addr, S_IRUGO, map_addr_show, NULL); | |
83 | static struct uio_sysfs_entry size_attribute = | |
84 | __ATTR(size, S_IRUGO, map_size_show, NULL); | |
e2b39df1 HK |
85 | static struct uio_sysfs_entry offset_attribute = |
86 | __ATTR(offset, S_IRUGO, map_offset_show, NULL); | |
beafc54c | 87 | |
81e7c6a6 | 88 | static struct attribute *attrs[] = { |
4f808bcd | 89 | &addr_attribute.attr, |
81e7c6a6 | 90 | &size_attribute.attr, |
e2b39df1 | 91 | &offset_attribute.attr, |
81e7c6a6 | 92 | NULL, /* need to NULL terminate the list of attributes */ |
beafc54c HK |
93 | }; |
94 | ||
81e7c6a6 GKH |
95 | static void map_release(struct kobject *kobj) |
96 | { | |
97 | struct uio_map *map = to_map(kobj); | |
98 | kfree(map); | |
99 | } | |
100 | ||
4f808bcd BP |
101 | static 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 uio_sysfs_entry *entry; | |
107 | ||
108 | entry = container_of(attr, struct uio_sysfs_entry, attr); | |
109 | ||
110 | if (!entry->show) | |
111 | return -EIO; | |
112 | ||
113 | return entry->show(mem, buf); | |
114 | } | |
115 | ||
116 | static struct sysfs_ops uio_sysfs_ops = { | |
117 | .show = map_type_show, | |
118 | }; | |
119 | ||
beafc54c | 120 | static struct kobj_type map_attr_type = { |
81e7c6a6 | 121 | .release = map_release, |
4f808bcd | 122 | .sysfs_ops = &uio_sysfs_ops, |
81e7c6a6 | 123 | .default_attrs = attrs, |
beafc54c HK |
124 | }; |
125 | ||
126 | static ssize_t show_name(struct device *dev, | |
127 | struct device_attribute *attr, char *buf) | |
128 | { | |
129 | struct uio_device *idev = dev_get_drvdata(dev); | |
130 | if (idev) | |
131 | return sprintf(buf, "%s\n", idev->info->name); | |
132 | else | |
133 | return -ENODEV; | |
134 | } | |
135 | static DEVICE_ATTR(name, S_IRUGO, show_name, NULL); | |
136 | ||
137 | static ssize_t show_version(struct device *dev, | |
138 | struct device_attribute *attr, char *buf) | |
139 | { | |
140 | struct uio_device *idev = dev_get_drvdata(dev); | |
141 | if (idev) | |
142 | return sprintf(buf, "%s\n", idev->info->version); | |
143 | else | |
144 | return -ENODEV; | |
145 | } | |
146 | static DEVICE_ATTR(version, S_IRUGO, show_version, NULL); | |
147 | ||
148 | static ssize_t show_event(struct device *dev, | |
149 | struct device_attribute *attr, char *buf) | |
150 | { | |
151 | struct uio_device *idev = dev_get_drvdata(dev); | |
152 | if (idev) | |
153 | return sprintf(buf, "%u\n", | |
154 | (unsigned int)atomic_read(&idev->event)); | |
155 | else | |
156 | return -ENODEV; | |
157 | } | |
158 | static DEVICE_ATTR(event, S_IRUGO, show_event, NULL); | |
159 | ||
160 | static struct attribute *uio_attrs[] = { | |
161 | &dev_attr_name.attr, | |
162 | &dev_attr_version.attr, | |
163 | &dev_attr_event.attr, | |
164 | NULL, | |
165 | }; | |
166 | ||
167 | static struct attribute_group uio_attr_grp = { | |
168 | .attrs = uio_attrs, | |
169 | }; | |
170 | ||
171 | /* | |
172 | * device functions | |
173 | */ | |
174 | static int uio_dev_add_attributes(struct uio_device *idev) | |
175 | { | |
176 | int ret; | |
177 | int mi; | |
178 | int map_found = 0; | |
179 | struct uio_mem *mem; | |
81e7c6a6 | 180 | struct uio_map *map; |
beafc54c HK |
181 | |
182 | ret = sysfs_create_group(&idev->dev->kobj, &uio_attr_grp); | |
183 | if (ret) | |
184 | goto err_group; | |
185 | ||
186 | for (mi = 0; mi < MAX_UIO_MAPS; mi++) { | |
187 | mem = &idev->info->mem[mi]; | |
188 | if (mem->size == 0) | |
189 | break; | |
190 | if (!map_found) { | |
191 | map_found = 1; | |
81e7c6a6 GKH |
192 | idev->map_dir = kobject_create_and_add("maps", |
193 | &idev->dev->kobj); | |
194 | if (!idev->map_dir) | |
195 | goto err; | |
beafc54c | 196 | } |
81e7c6a6 GKH |
197 | map = kzalloc(sizeof(*map), GFP_KERNEL); |
198 | if (!map) | |
199 | goto err; | |
f9cb074b | 200 | kobject_init(&map->kobj, &map_attr_type); |
81e7c6a6 GKH |
201 | map->mem = mem; |
202 | mem->map = map; | |
b2d6db58 | 203 | ret = kobject_add(&map->kobj, idev->map_dir, "map%d", mi); |
81e7c6a6 GKH |
204 | if (ret) |
205 | goto err; | |
206 | ret = kobject_uevent(&map->kobj, KOBJ_ADD); | |
beafc54c | 207 | if (ret) |
81e7c6a6 | 208 | goto err; |
beafc54c HK |
209 | } |
210 | ||
211 | return 0; | |
212 | ||
81e7c6a6 | 213 | err: |
beafc54c HK |
214 | for (mi--; mi>=0; mi--) { |
215 | mem = &idev->info->mem[mi]; | |
81e7c6a6 | 216 | map = mem->map; |
c10997f6 | 217 | kobject_put(&map->kobj); |
beafc54c | 218 | } |
c10997f6 | 219 | kobject_put(idev->map_dir); |
beafc54c HK |
220 | sysfs_remove_group(&idev->dev->kobj, &uio_attr_grp); |
221 | err_group: | |
222 | dev_err(idev->dev, "error creating sysfs files (%d)\n", ret); | |
223 | return ret; | |
224 | } | |
225 | ||
226 | static void uio_dev_del_attributes(struct uio_device *idev) | |
227 | { | |
228 | int mi; | |
229 | struct uio_mem *mem; | |
230 | for (mi = 0; mi < MAX_UIO_MAPS; mi++) { | |
231 | mem = &idev->info->mem[mi]; | |
232 | if (mem->size == 0) | |
233 | break; | |
c10997f6 | 234 | kobject_put(&mem->map->kobj); |
beafc54c | 235 | } |
c10997f6 | 236 | kobject_put(idev->map_dir); |
beafc54c HK |
237 | sysfs_remove_group(&idev->dev->kobj, &uio_attr_grp); |
238 | } | |
239 | ||
240 | static int uio_get_minor(struct uio_device *idev) | |
241 | { | |
242 | static DEFINE_MUTEX(minor_lock); | |
243 | int retval = -ENOMEM; | |
244 | int id; | |
245 | ||
246 | mutex_lock(&minor_lock); | |
247 | if (idr_pre_get(&uio_idr, GFP_KERNEL) == 0) | |
248 | goto exit; | |
249 | ||
250 | retval = idr_get_new(&uio_idr, idev, &id); | |
251 | if (retval < 0) { | |
252 | if (retval == -EAGAIN) | |
253 | retval = -ENOMEM; | |
254 | goto exit; | |
255 | } | |
256 | idev->minor = id & MAX_ID_MASK; | |
257 | exit: | |
258 | mutex_unlock(&minor_lock); | |
259 | return retval; | |
260 | } | |
261 | ||
262 | static void uio_free_minor(struct uio_device *idev) | |
263 | { | |
264 | idr_remove(&uio_idr, idev->minor); | |
265 | } | |
266 | ||
267 | /** | |
268 | * uio_event_notify - trigger an interrupt event | |
269 | * @info: UIO device capabilities | |
270 | */ | |
271 | void uio_event_notify(struct uio_info *info) | |
272 | { | |
273 | struct uio_device *idev = info->uio_dev; | |
274 | ||
275 | atomic_inc(&idev->event); | |
276 | wake_up_interruptible(&idev->wait); | |
277 | kill_fasync(&idev->async_queue, SIGIO, POLL_IN); | |
278 | } | |
279 | EXPORT_SYMBOL_GPL(uio_event_notify); | |
280 | ||
281 | /** | |
282 | * uio_interrupt - hardware interrupt handler | |
283 | * @irq: IRQ number, can be UIO_IRQ_CYCLIC for cyclic timer | |
284 | * @dev_id: Pointer to the devices uio_device structure | |
285 | */ | |
286 | static irqreturn_t uio_interrupt(int irq, void *dev_id) | |
287 | { | |
288 | struct uio_device *idev = (struct uio_device *)dev_id; | |
289 | irqreturn_t ret = idev->info->handler(irq, idev->info); | |
290 | ||
291 | if (ret == IRQ_HANDLED) | |
292 | uio_event_notify(idev->info); | |
293 | ||
294 | return ret; | |
295 | } | |
296 | ||
297 | struct uio_listener { | |
298 | struct uio_device *dev; | |
299 | s32 event_count; | |
300 | }; | |
301 | ||
302 | static int uio_open(struct inode *inode, struct file *filep) | |
303 | { | |
304 | struct uio_device *idev; | |
305 | struct uio_listener *listener; | |
306 | int ret = 0; | |
307 | ||
fbc8a81d | 308 | lock_kernel(); |
beafc54c | 309 | idev = idr_find(&uio_idr, iminor(inode)); |
fbc8a81d JC |
310 | if (!idev) { |
311 | ret = -ENODEV; | |
312 | goto out; | |
313 | } | |
beafc54c | 314 | |
fbc8a81d JC |
315 | if (!try_module_get(idev->owner)) { |
316 | ret = -ENODEV; | |
317 | goto out; | |
318 | } | |
610ad506 | 319 | |
beafc54c | 320 | listener = kmalloc(sizeof(*listener), GFP_KERNEL); |
610ad506 UKK |
321 | if (!listener) { |
322 | ret = -ENOMEM; | |
323 | goto err_alloc_listener; | |
324 | } | |
beafc54c HK |
325 | |
326 | listener->dev = idev; | |
327 | listener->event_count = atomic_read(&idev->event); | |
328 | filep->private_data = listener; | |
329 | ||
330 | if (idev->info->open) { | |
beafc54c | 331 | ret = idev->info->open(idev->info, inode); |
610ad506 UKK |
332 | if (ret) |
333 | goto err_infoopen; | |
beafc54c | 334 | } |
fbc8a81d | 335 | unlock_kernel(); |
610ad506 UKK |
336 | return 0; |
337 | ||
338 | err_infoopen: | |
339 | ||
340 | kfree(listener); | |
341 | err_alloc_listener: | |
342 | ||
343 | module_put(idev->owner); | |
beafc54c | 344 | |
fbc8a81d JC |
345 | out: |
346 | unlock_kernel(); | |
beafc54c HK |
347 | return ret; |
348 | } | |
349 | ||
350 | static int uio_fasync(int fd, struct file *filep, int on) | |
351 | { | |
352 | struct uio_listener *listener = filep->private_data; | |
353 | struct uio_device *idev = listener->dev; | |
354 | ||
355 | return fasync_helper(fd, filep, on, &idev->async_queue); | |
356 | } | |
357 | ||
358 | static int uio_release(struct inode *inode, struct file *filep) | |
359 | { | |
360 | int ret = 0; | |
361 | struct uio_listener *listener = filep->private_data; | |
362 | struct uio_device *idev = listener->dev; | |
363 | ||
610ad506 | 364 | if (idev->info->release) |
beafc54c | 365 | ret = idev->info->release(idev->info, inode); |
610ad506 UKK |
366 | |
367 | module_put(idev->owner); | |
368 | ||
beafc54c HK |
369 | if (filep->f_flags & FASYNC) |
370 | ret = uio_fasync(-1, filep, 0); | |
371 | kfree(listener); | |
372 | return ret; | |
373 | } | |
374 | ||
375 | static unsigned int uio_poll(struct file *filep, poll_table *wait) | |
376 | { | |
377 | struct uio_listener *listener = filep->private_data; | |
378 | struct uio_device *idev = listener->dev; | |
379 | ||
380 | if (idev->info->irq == UIO_IRQ_NONE) | |
381 | return -EIO; | |
382 | ||
383 | poll_wait(filep, &idev->wait, wait); | |
384 | if (listener->event_count != atomic_read(&idev->event)) | |
385 | return POLLIN | POLLRDNORM; | |
386 | return 0; | |
387 | } | |
388 | ||
389 | static ssize_t uio_read(struct file *filep, char __user *buf, | |
390 | size_t count, loff_t *ppos) | |
391 | { | |
392 | struct uio_listener *listener = filep->private_data; | |
393 | struct uio_device *idev = listener->dev; | |
394 | DECLARE_WAITQUEUE(wait, current); | |
395 | ssize_t retval; | |
396 | s32 event_count; | |
397 | ||
398 | if (idev->info->irq == UIO_IRQ_NONE) | |
399 | return -EIO; | |
400 | ||
401 | if (count != sizeof(s32)) | |
402 | return -EINVAL; | |
403 | ||
404 | add_wait_queue(&idev->wait, &wait); | |
405 | ||
406 | do { | |
407 | set_current_state(TASK_INTERRUPTIBLE); | |
408 | ||
409 | event_count = atomic_read(&idev->event); | |
410 | if (event_count != listener->event_count) { | |
411 | if (copy_to_user(buf, &event_count, count)) | |
412 | retval = -EFAULT; | |
413 | else { | |
414 | listener->event_count = event_count; | |
415 | retval = count; | |
416 | } | |
417 | break; | |
418 | } | |
419 | ||
420 | if (filep->f_flags & O_NONBLOCK) { | |
421 | retval = -EAGAIN; | |
422 | break; | |
423 | } | |
424 | ||
425 | if (signal_pending(current)) { | |
426 | retval = -ERESTARTSYS; | |
427 | break; | |
428 | } | |
429 | schedule(); | |
430 | } while (1); | |
431 | ||
432 | __set_current_state(TASK_RUNNING); | |
433 | remove_wait_queue(&idev->wait, &wait); | |
434 | ||
435 | return retval; | |
436 | } | |
437 | ||
328a14e7 HK |
438 | static ssize_t uio_write(struct file *filep, const char __user *buf, |
439 | size_t count, loff_t *ppos) | |
440 | { | |
441 | struct uio_listener *listener = filep->private_data; | |
442 | struct uio_device *idev = listener->dev; | |
443 | ssize_t retval; | |
444 | s32 irq_on; | |
445 | ||
446 | if (idev->info->irq == UIO_IRQ_NONE) | |
447 | return -EIO; | |
448 | ||
449 | if (count != sizeof(s32)) | |
450 | return -EINVAL; | |
451 | ||
452 | if (!idev->info->irqcontrol) | |
453 | return -ENOSYS; | |
454 | ||
455 | if (copy_from_user(&irq_on, buf, count)) | |
456 | return -EFAULT; | |
457 | ||
458 | retval = idev->info->irqcontrol(idev->info, irq_on); | |
459 | ||
460 | return retval ? retval : sizeof(s32); | |
461 | } | |
462 | ||
beafc54c HK |
463 | static int uio_find_mem_index(struct vm_area_struct *vma) |
464 | { | |
465 | int mi; | |
466 | struct uio_device *idev = vma->vm_private_data; | |
467 | ||
468 | for (mi = 0; mi < MAX_UIO_MAPS; mi++) { | |
469 | if (idev->info->mem[mi].size == 0) | |
470 | return -1; | |
471 | if (vma->vm_pgoff == mi) | |
472 | return mi; | |
473 | } | |
474 | return -1; | |
475 | } | |
476 | ||
477 | static void uio_vma_open(struct vm_area_struct *vma) | |
478 | { | |
479 | struct uio_device *idev = vma->vm_private_data; | |
480 | idev->vma_count++; | |
481 | } | |
482 | ||
483 | static void uio_vma_close(struct vm_area_struct *vma) | |
484 | { | |
485 | struct uio_device *idev = vma->vm_private_data; | |
486 | idev->vma_count--; | |
487 | } | |
488 | ||
a18b630d | 489 | static int uio_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
beafc54c HK |
490 | { |
491 | struct uio_device *idev = vma->vm_private_data; | |
a18b630d | 492 | struct page *page; |
02683ffd | 493 | unsigned long offset; |
beafc54c HK |
494 | |
495 | int mi = uio_find_mem_index(vma); | |
496 | if (mi < 0) | |
a18b630d | 497 | return VM_FAULT_SIGBUS; |
beafc54c | 498 | |
02683ffd AH |
499 | /* |
500 | * We need to subtract mi because userspace uses offset = N*PAGE_SIZE | |
501 | * to use mem[N]. | |
502 | */ | |
503 | offset = (vmf->pgoff - mi) << PAGE_SHIFT; | |
504 | ||
beafc54c | 505 | if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL) |
02683ffd | 506 | page = virt_to_page(idev->info->mem[mi].addr + offset); |
beafc54c | 507 | else |
02683ffd AH |
508 | page = vmalloc_to_page((void *)idev->info->mem[mi].addr |
509 | + offset); | |
beafc54c | 510 | get_page(page); |
a18b630d NP |
511 | vmf->page = page; |
512 | return 0; | |
beafc54c HK |
513 | } |
514 | ||
515 | static struct vm_operations_struct uio_vm_ops = { | |
516 | .open = uio_vma_open, | |
517 | .close = uio_vma_close, | |
a18b630d | 518 | .fault = uio_vma_fault, |
beafc54c HK |
519 | }; |
520 | ||
521 | static int uio_mmap_physical(struct vm_area_struct *vma) | |
522 | { | |
523 | struct uio_device *idev = vma->vm_private_data; | |
524 | int mi = uio_find_mem_index(vma); | |
525 | if (mi < 0) | |
526 | return -EINVAL; | |
527 | ||
528 | vma->vm_flags |= VM_IO | VM_RESERVED; | |
c9698d6b JSC |
529 | |
530 | vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); | |
beafc54c HK |
531 | |
532 | return remap_pfn_range(vma, | |
533 | vma->vm_start, | |
534 | idev->info->mem[mi].addr >> PAGE_SHIFT, | |
535 | vma->vm_end - vma->vm_start, | |
536 | vma->vm_page_prot); | |
537 | } | |
538 | ||
539 | static int uio_mmap_logical(struct vm_area_struct *vma) | |
540 | { | |
541 | vma->vm_flags |= VM_RESERVED; | |
542 | vma->vm_ops = &uio_vm_ops; | |
543 | uio_vma_open(vma); | |
544 | return 0; | |
545 | } | |
546 | ||
547 | static int uio_mmap(struct file *filep, struct vm_area_struct *vma) | |
548 | { | |
549 | struct uio_listener *listener = filep->private_data; | |
550 | struct uio_device *idev = listener->dev; | |
551 | int mi; | |
552 | unsigned long requested_pages, actual_pages; | |
553 | int ret = 0; | |
554 | ||
555 | if (vma->vm_end < vma->vm_start) | |
556 | return -EINVAL; | |
557 | ||
558 | vma->vm_private_data = idev; | |
559 | ||
560 | mi = uio_find_mem_index(vma); | |
561 | if (mi < 0) | |
562 | return -EINVAL; | |
563 | ||
564 | requested_pages = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; | |
565 | actual_pages = (idev->info->mem[mi].size + PAGE_SIZE -1) >> PAGE_SHIFT; | |
566 | if (requested_pages > actual_pages) | |
567 | return -EINVAL; | |
568 | ||
569 | if (idev->info->mmap) { | |
beafc54c | 570 | ret = idev->info->mmap(idev->info, vma); |
beafc54c HK |
571 | return ret; |
572 | } | |
573 | ||
574 | switch (idev->info->mem[mi].memtype) { | |
575 | case UIO_MEM_PHYS: | |
576 | return uio_mmap_physical(vma); | |
577 | case UIO_MEM_LOGICAL: | |
578 | case UIO_MEM_VIRTUAL: | |
579 | return uio_mmap_logical(vma); | |
580 | default: | |
581 | return -EINVAL; | |
582 | } | |
583 | } | |
584 | ||
4f014691 | 585 | static const struct file_operations uio_fops = { |
beafc54c HK |
586 | .owner = THIS_MODULE, |
587 | .open = uio_open, | |
588 | .release = uio_release, | |
589 | .read = uio_read, | |
328a14e7 | 590 | .write = uio_write, |
beafc54c HK |
591 | .mmap = uio_mmap, |
592 | .poll = uio_poll, | |
593 | .fasync = uio_fasync, | |
594 | }; | |
595 | ||
596 | static int uio_major_init(void) | |
597 | { | |
598 | uio_major = register_chrdev(0, "uio", &uio_fops); | |
599 | if (uio_major < 0) | |
600 | return uio_major; | |
601 | return 0; | |
602 | } | |
603 | ||
604 | static void uio_major_cleanup(void) | |
605 | { | |
606 | unregister_chrdev(uio_major, "uio"); | |
607 | } | |
608 | ||
609 | static int init_uio_class(void) | |
610 | { | |
611 | int ret = 0; | |
612 | ||
613 | if (uio_class != NULL) { | |
614 | kref_get(&uio_class->kref); | |
615 | goto exit; | |
616 | } | |
617 | ||
618 | /* This is the first time in here, set everything up properly */ | |
619 | ret = uio_major_init(); | |
620 | if (ret) | |
621 | goto exit; | |
622 | ||
623 | uio_class = kzalloc(sizeof(*uio_class), GFP_KERNEL); | |
624 | if (!uio_class) { | |
625 | ret = -ENOMEM; | |
626 | goto err_kzalloc; | |
627 | } | |
628 | ||
629 | kref_init(&uio_class->kref); | |
630 | uio_class->class = class_create(THIS_MODULE, "uio"); | |
631 | if (IS_ERR(uio_class->class)) { | |
632 | ret = IS_ERR(uio_class->class); | |
633 | printk(KERN_ERR "class_create failed for uio\n"); | |
634 | goto err_class_create; | |
635 | } | |
636 | return 0; | |
637 | ||
638 | err_class_create: | |
639 | kfree(uio_class); | |
640 | uio_class = NULL; | |
641 | err_kzalloc: | |
642 | uio_major_cleanup(); | |
643 | exit: | |
644 | return ret; | |
645 | } | |
646 | ||
647 | static void release_uio_class(struct kref *kref) | |
648 | { | |
649 | /* Ok, we cheat as we know we only have one uio_class */ | |
650 | class_destroy(uio_class->class); | |
651 | kfree(uio_class); | |
652 | uio_major_cleanup(); | |
653 | uio_class = NULL; | |
654 | } | |
655 | ||
656 | static void uio_class_destroy(void) | |
657 | { | |
658 | if (uio_class) | |
659 | kref_put(&uio_class->kref, release_uio_class); | |
660 | } | |
661 | ||
662 | /** | |
663 | * uio_register_device - register a new userspace IO device | |
664 | * @owner: module that creates the new device | |
665 | * @parent: parent device | |
666 | * @info: UIO device capabilities | |
667 | * | |
668 | * returns zero on success or a negative error code. | |
669 | */ | |
670 | int __uio_register_device(struct module *owner, | |
671 | struct device *parent, | |
672 | struct uio_info *info) | |
673 | { | |
674 | struct uio_device *idev; | |
675 | int ret = 0; | |
676 | ||
677 | if (!parent || !info || !info->name || !info->version) | |
678 | return -EINVAL; | |
679 | ||
680 | info->uio_dev = NULL; | |
681 | ||
682 | ret = init_uio_class(); | |
683 | if (ret) | |
684 | return ret; | |
685 | ||
686 | idev = kzalloc(sizeof(*idev), GFP_KERNEL); | |
687 | if (!idev) { | |
688 | ret = -ENOMEM; | |
689 | goto err_kzalloc; | |
690 | } | |
691 | ||
692 | idev->owner = owner; | |
693 | idev->info = info; | |
694 | init_waitqueue_head(&idev->wait); | |
695 | atomic_set(&idev->event, 0); | |
696 | ||
697 | ret = uio_get_minor(idev); | |
698 | if (ret) | |
699 | goto err_get_minor; | |
700 | ||
a9b12619 GKH |
701 | idev->dev = device_create(uio_class->class, parent, |
702 | MKDEV(uio_major, idev->minor), idev, | |
703 | "uio%d", idev->minor); | |
beafc54c HK |
704 | if (IS_ERR(idev->dev)) { |
705 | printk(KERN_ERR "UIO: device register failed\n"); | |
706 | ret = PTR_ERR(idev->dev); | |
707 | goto err_device_create; | |
708 | } | |
beafc54c HK |
709 | |
710 | ret = uio_dev_add_attributes(idev); | |
711 | if (ret) | |
712 | goto err_uio_dev_add_attributes; | |
713 | ||
714 | info->uio_dev = idev; | |
715 | ||
716 | if (idev->info->irq >= 0) { | |
717 | ret = request_irq(idev->info->irq, uio_interrupt, | |
718 | idev->info->irq_flags, idev->info->name, idev); | |
719 | if (ret) | |
720 | goto err_request_irq; | |
721 | } | |
722 | ||
723 | return 0; | |
724 | ||
725 | err_request_irq: | |
726 | uio_dev_del_attributes(idev); | |
727 | err_uio_dev_add_attributes: | |
728 | device_destroy(uio_class->class, MKDEV(uio_major, idev->minor)); | |
729 | err_device_create: | |
730 | uio_free_minor(idev); | |
731 | err_get_minor: | |
732 | kfree(idev); | |
733 | err_kzalloc: | |
734 | uio_class_destroy(); | |
735 | return ret; | |
736 | } | |
737 | EXPORT_SYMBOL_GPL(__uio_register_device); | |
738 | ||
739 | /** | |
740 | * uio_unregister_device - unregister a industrial IO device | |
741 | * @info: UIO device capabilities | |
742 | * | |
743 | */ | |
744 | void uio_unregister_device(struct uio_info *info) | |
745 | { | |
746 | struct uio_device *idev; | |
747 | ||
748 | if (!info || !info->uio_dev) | |
749 | return; | |
750 | ||
751 | idev = info->uio_dev; | |
752 | ||
753 | uio_free_minor(idev); | |
754 | ||
755 | if (info->irq >= 0) | |
756 | free_irq(info->irq, idev); | |
757 | ||
758 | uio_dev_del_attributes(idev); | |
759 | ||
760 | dev_set_drvdata(idev->dev, NULL); | |
761 | device_destroy(uio_class->class, MKDEV(uio_major, idev->minor)); | |
762 | kfree(idev); | |
763 | uio_class_destroy(); | |
764 | ||
765 | return; | |
766 | } | |
767 | EXPORT_SYMBOL_GPL(uio_unregister_device); | |
768 | ||
769 | static int __init uio_init(void) | |
770 | { | |
771 | return 0; | |
772 | } | |
773 | ||
774 | static void __exit uio_exit(void) | |
775 | { | |
776 | } | |
777 | ||
778 | module_init(uio_init) | |
779 | module_exit(uio_exit) | |
780 | MODULE_LICENSE("GPL v2"); |