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 | ||
0d4a7bc1 JC |
50 | /* Protect idr accesses */ |
51 | static DEFINE_MUTEX(minor_lock); | |
52 | ||
beafc54c HK |
53 | /* |
54 | * attributes | |
55 | */ | |
56 | ||
81e7c6a6 GKH |
57 | struct uio_map { |
58 | struct kobject kobj; | |
59 | struct uio_mem *mem; | |
beafc54c | 60 | }; |
81e7c6a6 | 61 | #define to_map(map) container_of(map, struct uio_map, kobj) |
beafc54c | 62 | |
4f808bcd | 63 | static ssize_t map_addr_show(struct uio_mem *mem, char *buf) |
beafc54c | 64 | { |
4f808bcd BP |
65 | return sprintf(buf, "0x%lx\n", mem->addr); |
66 | } | |
beafc54c | 67 | |
4f808bcd BP |
68 | static ssize_t map_size_show(struct uio_mem *mem, char *buf) |
69 | { | |
70 | return sprintf(buf, "0x%lx\n", mem->size); | |
beafc54c HK |
71 | } |
72 | ||
e2b39df1 HK |
73 | static ssize_t map_offset_show(struct uio_mem *mem, char *buf) |
74 | { | |
75 | return sprintf(buf, "0x%lx\n", mem->addr & ~PAGE_MASK); | |
76 | } | |
77 | ||
4f808bcd BP |
78 | struct uio_sysfs_entry { |
79 | struct attribute attr; | |
80 | ssize_t (*show)(struct uio_mem *, char *); | |
81 | ssize_t (*store)(struct uio_mem *, const char *, size_t); | |
82 | }; | |
83 | ||
84 | static struct uio_sysfs_entry addr_attribute = | |
85 | __ATTR(addr, S_IRUGO, map_addr_show, NULL); | |
86 | static struct uio_sysfs_entry size_attribute = | |
87 | __ATTR(size, S_IRUGO, map_size_show, NULL); | |
e2b39df1 HK |
88 | static struct uio_sysfs_entry offset_attribute = |
89 | __ATTR(offset, S_IRUGO, map_offset_show, NULL); | |
beafc54c | 90 | |
81e7c6a6 | 91 | static struct attribute *attrs[] = { |
4f808bcd | 92 | &addr_attribute.attr, |
81e7c6a6 | 93 | &size_attribute.attr, |
e2b39df1 | 94 | &offset_attribute.attr, |
81e7c6a6 | 95 | NULL, /* need to NULL terminate the list of attributes */ |
beafc54c HK |
96 | }; |
97 | ||
81e7c6a6 GKH |
98 | static void map_release(struct kobject *kobj) |
99 | { | |
100 | struct uio_map *map = to_map(kobj); | |
101 | kfree(map); | |
102 | } | |
103 | ||
4f808bcd BP |
104 | static ssize_t map_type_show(struct kobject *kobj, struct attribute *attr, |
105 | char *buf) | |
106 | { | |
107 | struct uio_map *map = to_map(kobj); | |
108 | struct uio_mem *mem = map->mem; | |
109 | struct uio_sysfs_entry *entry; | |
110 | ||
111 | entry = container_of(attr, struct uio_sysfs_entry, attr); | |
112 | ||
113 | if (!entry->show) | |
114 | return -EIO; | |
115 | ||
116 | return entry->show(mem, buf); | |
117 | } | |
118 | ||
119 | static struct sysfs_ops uio_sysfs_ops = { | |
120 | .show = map_type_show, | |
121 | }; | |
122 | ||
beafc54c | 123 | static struct kobj_type map_attr_type = { |
81e7c6a6 | 124 | .release = map_release, |
4f808bcd | 125 | .sysfs_ops = &uio_sysfs_ops, |
81e7c6a6 | 126 | .default_attrs = attrs, |
beafc54c HK |
127 | }; |
128 | ||
129 | static ssize_t show_name(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->name); | |
135 | else | |
136 | return -ENODEV; | |
137 | } | |
138 | static DEVICE_ATTR(name, S_IRUGO, show_name, NULL); | |
139 | ||
140 | static ssize_t show_version(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, "%s\n", idev->info->version); | |
146 | else | |
147 | return -ENODEV; | |
148 | } | |
149 | static DEVICE_ATTR(version, S_IRUGO, show_version, NULL); | |
150 | ||
151 | static ssize_t show_event(struct device *dev, | |
152 | struct device_attribute *attr, char *buf) | |
153 | { | |
154 | struct uio_device *idev = dev_get_drvdata(dev); | |
155 | if (idev) | |
156 | return sprintf(buf, "%u\n", | |
157 | (unsigned int)atomic_read(&idev->event)); | |
158 | else | |
159 | return -ENODEV; | |
160 | } | |
161 | static DEVICE_ATTR(event, S_IRUGO, show_event, NULL); | |
162 | ||
163 | static struct attribute *uio_attrs[] = { | |
164 | &dev_attr_name.attr, | |
165 | &dev_attr_version.attr, | |
166 | &dev_attr_event.attr, | |
167 | NULL, | |
168 | }; | |
169 | ||
170 | static struct attribute_group uio_attr_grp = { | |
171 | .attrs = uio_attrs, | |
172 | }; | |
173 | ||
174 | /* | |
175 | * device functions | |
176 | */ | |
177 | static int uio_dev_add_attributes(struct uio_device *idev) | |
178 | { | |
179 | int ret; | |
180 | int mi; | |
181 | int map_found = 0; | |
182 | struct uio_mem *mem; | |
81e7c6a6 | 183 | struct uio_map *map; |
beafc54c HK |
184 | |
185 | ret = sysfs_create_group(&idev->dev->kobj, &uio_attr_grp); | |
186 | if (ret) | |
187 | goto err_group; | |
188 | ||
189 | for (mi = 0; mi < MAX_UIO_MAPS; mi++) { | |
190 | mem = &idev->info->mem[mi]; | |
191 | if (mem->size == 0) | |
192 | break; | |
193 | if (!map_found) { | |
194 | map_found = 1; | |
81e7c6a6 GKH |
195 | idev->map_dir = kobject_create_and_add("maps", |
196 | &idev->dev->kobj); | |
197 | if (!idev->map_dir) | |
198 | goto err; | |
beafc54c | 199 | } |
81e7c6a6 GKH |
200 | map = kzalloc(sizeof(*map), GFP_KERNEL); |
201 | if (!map) | |
202 | goto err; | |
f9cb074b | 203 | kobject_init(&map->kobj, &map_attr_type); |
81e7c6a6 GKH |
204 | map->mem = mem; |
205 | mem->map = map; | |
b2d6db58 | 206 | ret = kobject_add(&map->kobj, idev->map_dir, "map%d", mi); |
81e7c6a6 GKH |
207 | if (ret) |
208 | goto err; | |
209 | ret = kobject_uevent(&map->kobj, KOBJ_ADD); | |
beafc54c | 210 | if (ret) |
81e7c6a6 | 211 | goto err; |
beafc54c HK |
212 | } |
213 | ||
214 | return 0; | |
215 | ||
81e7c6a6 | 216 | err: |
beafc54c HK |
217 | for (mi--; mi>=0; mi--) { |
218 | mem = &idev->info->mem[mi]; | |
81e7c6a6 | 219 | map = mem->map; |
c10997f6 | 220 | kobject_put(&map->kobj); |
beafc54c | 221 | } |
c10997f6 | 222 | kobject_put(idev->map_dir); |
beafc54c HK |
223 | sysfs_remove_group(&idev->dev->kobj, &uio_attr_grp); |
224 | err_group: | |
225 | dev_err(idev->dev, "error creating sysfs files (%d)\n", ret); | |
226 | return ret; | |
227 | } | |
228 | ||
229 | static void uio_dev_del_attributes(struct uio_device *idev) | |
230 | { | |
231 | int mi; | |
232 | struct uio_mem *mem; | |
233 | for (mi = 0; mi < MAX_UIO_MAPS; mi++) { | |
234 | mem = &idev->info->mem[mi]; | |
235 | if (mem->size == 0) | |
236 | break; | |
c10997f6 | 237 | kobject_put(&mem->map->kobj); |
beafc54c | 238 | } |
c10997f6 | 239 | kobject_put(idev->map_dir); |
beafc54c HK |
240 | sysfs_remove_group(&idev->dev->kobj, &uio_attr_grp); |
241 | } | |
242 | ||
243 | static int uio_get_minor(struct uio_device *idev) | |
244 | { | |
beafc54c HK |
245 | int retval = -ENOMEM; |
246 | int id; | |
247 | ||
248 | mutex_lock(&minor_lock); | |
249 | if (idr_pre_get(&uio_idr, GFP_KERNEL) == 0) | |
250 | goto exit; | |
251 | ||
252 | retval = idr_get_new(&uio_idr, idev, &id); | |
253 | if (retval < 0) { | |
254 | if (retval == -EAGAIN) | |
255 | retval = -ENOMEM; | |
256 | goto exit; | |
257 | } | |
258 | idev->minor = id & MAX_ID_MASK; | |
259 | exit: | |
260 | mutex_unlock(&minor_lock); | |
261 | return retval; | |
262 | } | |
263 | ||
264 | static void uio_free_minor(struct uio_device *idev) | |
265 | { | |
0d4a7bc1 | 266 | mutex_lock(&minor_lock); |
beafc54c | 267 | idr_remove(&uio_idr, idev->minor); |
0d4a7bc1 | 268 | mutex_unlock(&minor_lock); |
beafc54c HK |
269 | } |
270 | ||
271 | /** | |
272 | * uio_event_notify - trigger an interrupt event | |
273 | * @info: UIO device capabilities | |
274 | */ | |
275 | void uio_event_notify(struct uio_info *info) | |
276 | { | |
277 | struct uio_device *idev = info->uio_dev; | |
278 | ||
279 | atomic_inc(&idev->event); | |
280 | wake_up_interruptible(&idev->wait); | |
281 | kill_fasync(&idev->async_queue, SIGIO, POLL_IN); | |
282 | } | |
283 | EXPORT_SYMBOL_GPL(uio_event_notify); | |
284 | ||
285 | /** | |
286 | * uio_interrupt - hardware interrupt handler | |
287 | * @irq: IRQ number, can be UIO_IRQ_CYCLIC for cyclic timer | |
288 | * @dev_id: Pointer to the devices uio_device structure | |
289 | */ | |
290 | static irqreturn_t uio_interrupt(int irq, void *dev_id) | |
291 | { | |
292 | struct uio_device *idev = (struct uio_device *)dev_id; | |
293 | irqreturn_t ret = idev->info->handler(irq, idev->info); | |
294 | ||
295 | if (ret == IRQ_HANDLED) | |
296 | uio_event_notify(idev->info); | |
297 | ||
298 | return ret; | |
299 | } | |
300 | ||
301 | struct uio_listener { | |
302 | struct uio_device *dev; | |
303 | s32 event_count; | |
304 | }; | |
305 | ||
306 | static int uio_open(struct inode *inode, struct file *filep) | |
307 | { | |
308 | struct uio_device *idev; | |
309 | struct uio_listener *listener; | |
310 | int ret = 0; | |
311 | ||
0d4a7bc1 | 312 | mutex_lock(&minor_lock); |
beafc54c | 313 | idev = idr_find(&uio_idr, iminor(inode)); |
0d4a7bc1 | 314 | mutex_unlock(&minor_lock); |
fbc8a81d JC |
315 | if (!idev) { |
316 | ret = -ENODEV; | |
317 | goto out; | |
318 | } | |
beafc54c | 319 | |
fbc8a81d JC |
320 | if (!try_module_get(idev->owner)) { |
321 | ret = -ENODEV; | |
322 | goto out; | |
323 | } | |
610ad506 | 324 | |
beafc54c | 325 | listener = kmalloc(sizeof(*listener), GFP_KERNEL); |
610ad506 UKK |
326 | if (!listener) { |
327 | ret = -ENOMEM; | |
328 | goto err_alloc_listener; | |
329 | } | |
beafc54c HK |
330 | |
331 | listener->dev = idev; | |
332 | listener->event_count = atomic_read(&idev->event); | |
333 | filep->private_data = listener; | |
334 | ||
335 | if (idev->info->open) { | |
beafc54c | 336 | ret = idev->info->open(idev->info, inode); |
610ad506 UKK |
337 | if (ret) |
338 | goto err_infoopen; | |
beafc54c | 339 | } |
610ad506 UKK |
340 | return 0; |
341 | ||
342 | err_infoopen: | |
610ad506 | 343 | kfree(listener); |
610ad506 | 344 | |
0d4a7bc1 | 345 | err_alloc_listener: |
610ad506 | 346 | module_put(idev->owner); |
beafc54c | 347 | |
fbc8a81d | 348 | out: |
beafc54c HK |
349 | return ret; |
350 | } | |
351 | ||
352 | static int uio_fasync(int fd, struct file *filep, int on) | |
353 | { | |
354 | struct uio_listener *listener = filep->private_data; | |
355 | struct uio_device *idev = listener->dev; | |
356 | ||
357 | return fasync_helper(fd, filep, on, &idev->async_queue); | |
358 | } | |
359 | ||
360 | static int uio_release(struct inode *inode, struct file *filep) | |
361 | { | |
362 | int ret = 0; | |
363 | struct uio_listener *listener = filep->private_data; | |
364 | struct uio_device *idev = listener->dev; | |
365 | ||
610ad506 | 366 | if (idev->info->release) |
beafc54c | 367 | ret = idev->info->release(idev->info, inode); |
610ad506 UKK |
368 | |
369 | module_put(idev->owner); | |
beafc54c HK |
370 | kfree(listener); |
371 | return ret; | |
372 | } | |
373 | ||
374 | static unsigned int uio_poll(struct file *filep, poll_table *wait) | |
375 | { | |
376 | struct uio_listener *listener = filep->private_data; | |
377 | struct uio_device *idev = listener->dev; | |
378 | ||
379 | if (idev->info->irq == UIO_IRQ_NONE) | |
380 | return -EIO; | |
381 | ||
382 | poll_wait(filep, &idev->wait, wait); | |
383 | if (listener->event_count != atomic_read(&idev->event)) | |
384 | return POLLIN | POLLRDNORM; | |
385 | return 0; | |
386 | } | |
387 | ||
388 | static ssize_t uio_read(struct file *filep, char __user *buf, | |
389 | size_t count, loff_t *ppos) | |
390 | { | |
391 | struct uio_listener *listener = filep->private_data; | |
392 | struct uio_device *idev = listener->dev; | |
393 | DECLARE_WAITQUEUE(wait, current); | |
394 | ssize_t retval; | |
395 | s32 event_count; | |
396 | ||
397 | if (idev->info->irq == UIO_IRQ_NONE) | |
398 | return -EIO; | |
399 | ||
400 | if (count != sizeof(s32)) | |
401 | return -EINVAL; | |
402 | ||
403 | add_wait_queue(&idev->wait, &wait); | |
404 | ||
405 | do { | |
406 | set_current_state(TASK_INTERRUPTIBLE); | |
407 | ||
408 | event_count = atomic_read(&idev->event); | |
409 | if (event_count != listener->event_count) { | |
410 | if (copy_to_user(buf, &event_count, count)) | |
411 | retval = -EFAULT; | |
412 | else { | |
413 | listener->event_count = event_count; | |
414 | retval = count; | |
415 | } | |
416 | break; | |
417 | } | |
418 | ||
419 | if (filep->f_flags & O_NONBLOCK) { | |
420 | retval = -EAGAIN; | |
421 | break; | |
422 | } | |
423 | ||
424 | if (signal_pending(current)) { | |
425 | retval = -ERESTARTSYS; | |
426 | break; | |
427 | } | |
428 | schedule(); | |
429 | } while (1); | |
430 | ||
431 | __set_current_state(TASK_RUNNING); | |
432 | remove_wait_queue(&idev->wait, &wait); | |
433 | ||
434 | return retval; | |
435 | } | |
436 | ||
328a14e7 HK |
437 | static ssize_t uio_write(struct file *filep, const char __user *buf, |
438 | size_t count, loff_t *ppos) | |
439 | { | |
440 | struct uio_listener *listener = filep->private_data; | |
441 | struct uio_device *idev = listener->dev; | |
442 | ssize_t retval; | |
443 | s32 irq_on; | |
444 | ||
445 | if (idev->info->irq == UIO_IRQ_NONE) | |
446 | return -EIO; | |
447 | ||
448 | if (count != sizeof(s32)) | |
449 | return -EINVAL; | |
450 | ||
451 | if (!idev->info->irqcontrol) | |
452 | return -ENOSYS; | |
453 | ||
454 | if (copy_from_user(&irq_on, buf, count)) | |
455 | return -EFAULT; | |
456 | ||
457 | retval = idev->info->irqcontrol(idev->info, irq_on); | |
458 | ||
459 | return retval ? retval : sizeof(s32); | |
460 | } | |
461 | ||
beafc54c HK |
462 | static int uio_find_mem_index(struct vm_area_struct *vma) |
463 | { | |
464 | int mi; | |
465 | struct uio_device *idev = vma->vm_private_data; | |
466 | ||
467 | for (mi = 0; mi < MAX_UIO_MAPS; mi++) { | |
468 | if (idev->info->mem[mi].size == 0) | |
469 | return -1; | |
470 | if (vma->vm_pgoff == mi) | |
471 | return mi; | |
472 | } | |
473 | return -1; | |
474 | } | |
475 | ||
476 | static void uio_vma_open(struct vm_area_struct *vma) | |
477 | { | |
478 | struct uio_device *idev = vma->vm_private_data; | |
479 | idev->vma_count++; | |
480 | } | |
481 | ||
482 | static void uio_vma_close(struct vm_area_struct *vma) | |
483 | { | |
484 | struct uio_device *idev = vma->vm_private_data; | |
485 | idev->vma_count--; | |
486 | } | |
487 | ||
a18b630d | 488 | static int uio_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
beafc54c HK |
489 | { |
490 | struct uio_device *idev = vma->vm_private_data; | |
a18b630d | 491 | struct page *page; |
02683ffd | 492 | unsigned long offset; |
beafc54c HK |
493 | |
494 | int mi = uio_find_mem_index(vma); | |
495 | if (mi < 0) | |
a18b630d | 496 | return VM_FAULT_SIGBUS; |
beafc54c | 497 | |
02683ffd AH |
498 | /* |
499 | * We need to subtract mi because userspace uses offset = N*PAGE_SIZE | |
500 | * to use mem[N]. | |
501 | */ | |
502 | offset = (vmf->pgoff - mi) << PAGE_SHIFT; | |
503 | ||
beafc54c | 504 | if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL) |
02683ffd | 505 | page = virt_to_page(idev->info->mem[mi].addr + offset); |
beafc54c | 506 | else |
02683ffd AH |
507 | page = vmalloc_to_page((void *)idev->info->mem[mi].addr |
508 | + offset); | |
beafc54c | 509 | get_page(page); |
a18b630d NP |
510 | vmf->page = page; |
511 | return 0; | |
beafc54c HK |
512 | } |
513 | ||
514 | static struct vm_operations_struct uio_vm_ops = { | |
515 | .open = uio_vma_open, | |
516 | .close = uio_vma_close, | |
a18b630d | 517 | .fault = uio_vma_fault, |
beafc54c HK |
518 | }; |
519 | ||
520 | static int uio_mmap_physical(struct vm_area_struct *vma) | |
521 | { | |
522 | struct uio_device *idev = vma->vm_private_data; | |
523 | int mi = uio_find_mem_index(vma); | |
524 | if (mi < 0) | |
525 | return -EINVAL; | |
526 | ||
527 | vma->vm_flags |= VM_IO | VM_RESERVED; | |
c9698d6b JSC |
528 | |
529 | vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); | |
beafc54c HK |
530 | |
531 | return remap_pfn_range(vma, | |
532 | vma->vm_start, | |
533 | idev->info->mem[mi].addr >> PAGE_SHIFT, | |
534 | vma->vm_end - vma->vm_start, | |
535 | vma->vm_page_prot); | |
536 | } | |
537 | ||
538 | static int uio_mmap_logical(struct vm_area_struct *vma) | |
539 | { | |
540 | vma->vm_flags |= VM_RESERVED; | |
541 | vma->vm_ops = &uio_vm_ops; | |
542 | uio_vma_open(vma); | |
543 | return 0; | |
544 | } | |
545 | ||
546 | static int uio_mmap(struct file *filep, struct vm_area_struct *vma) | |
547 | { | |
548 | struct uio_listener *listener = filep->private_data; | |
549 | struct uio_device *idev = listener->dev; | |
550 | int mi; | |
551 | unsigned long requested_pages, actual_pages; | |
552 | int ret = 0; | |
553 | ||
554 | if (vma->vm_end < vma->vm_start) | |
555 | return -EINVAL; | |
556 | ||
557 | vma->vm_private_data = idev; | |
558 | ||
559 | mi = uio_find_mem_index(vma); | |
560 | if (mi < 0) | |
561 | return -EINVAL; | |
562 | ||
563 | requested_pages = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; | |
564 | actual_pages = (idev->info->mem[mi].size + PAGE_SIZE -1) >> PAGE_SHIFT; | |
565 | if (requested_pages > actual_pages) | |
566 | return -EINVAL; | |
567 | ||
568 | if (idev->info->mmap) { | |
beafc54c | 569 | ret = idev->info->mmap(idev->info, vma); |
beafc54c HK |
570 | return ret; |
571 | } | |
572 | ||
573 | switch (idev->info->mem[mi].memtype) { | |
574 | case UIO_MEM_PHYS: | |
575 | return uio_mmap_physical(vma); | |
576 | case UIO_MEM_LOGICAL: | |
577 | case UIO_MEM_VIRTUAL: | |
578 | return uio_mmap_logical(vma); | |
579 | default: | |
580 | return -EINVAL; | |
581 | } | |
582 | } | |
583 | ||
4f014691 | 584 | static const struct file_operations uio_fops = { |
beafc54c HK |
585 | .owner = THIS_MODULE, |
586 | .open = uio_open, | |
587 | .release = uio_release, | |
588 | .read = uio_read, | |
328a14e7 | 589 | .write = uio_write, |
beafc54c HK |
590 | .mmap = uio_mmap, |
591 | .poll = uio_poll, | |
592 | .fasync = uio_fasync, | |
593 | }; | |
594 | ||
595 | static int uio_major_init(void) | |
596 | { | |
597 | uio_major = register_chrdev(0, "uio", &uio_fops); | |
598 | if (uio_major < 0) | |
599 | return uio_major; | |
600 | return 0; | |
601 | } | |
602 | ||
603 | static void uio_major_cleanup(void) | |
604 | { | |
605 | unregister_chrdev(uio_major, "uio"); | |
606 | } | |
607 | ||
608 | static int init_uio_class(void) | |
609 | { | |
610 | int ret = 0; | |
611 | ||
612 | if (uio_class != NULL) { | |
613 | kref_get(&uio_class->kref); | |
614 | goto exit; | |
615 | } | |
616 | ||
617 | /* This is the first time in here, set everything up properly */ | |
618 | ret = uio_major_init(); | |
619 | if (ret) | |
620 | goto exit; | |
621 | ||
622 | uio_class = kzalloc(sizeof(*uio_class), GFP_KERNEL); | |
623 | if (!uio_class) { | |
624 | ret = -ENOMEM; | |
625 | goto err_kzalloc; | |
626 | } | |
627 | ||
628 | kref_init(&uio_class->kref); | |
629 | uio_class->class = class_create(THIS_MODULE, "uio"); | |
630 | if (IS_ERR(uio_class->class)) { | |
631 | ret = IS_ERR(uio_class->class); | |
632 | printk(KERN_ERR "class_create failed for uio\n"); | |
633 | goto err_class_create; | |
634 | } | |
635 | return 0; | |
636 | ||
637 | err_class_create: | |
638 | kfree(uio_class); | |
639 | uio_class = NULL; | |
640 | err_kzalloc: | |
641 | uio_major_cleanup(); | |
642 | exit: | |
643 | return ret; | |
644 | } | |
645 | ||
646 | static void release_uio_class(struct kref *kref) | |
647 | { | |
648 | /* Ok, we cheat as we know we only have one uio_class */ | |
649 | class_destroy(uio_class->class); | |
650 | kfree(uio_class); | |
651 | uio_major_cleanup(); | |
652 | uio_class = NULL; | |
653 | } | |
654 | ||
655 | static void uio_class_destroy(void) | |
656 | { | |
657 | if (uio_class) | |
658 | kref_put(&uio_class->kref, release_uio_class); | |
659 | } | |
660 | ||
661 | /** | |
662 | * uio_register_device - register a new userspace IO device | |
663 | * @owner: module that creates the new device | |
664 | * @parent: parent device | |
665 | * @info: UIO device capabilities | |
666 | * | |
667 | * returns zero on success or a negative error code. | |
668 | */ | |
669 | int __uio_register_device(struct module *owner, | |
670 | struct device *parent, | |
671 | struct uio_info *info) | |
672 | { | |
673 | struct uio_device *idev; | |
674 | int ret = 0; | |
675 | ||
676 | if (!parent || !info || !info->name || !info->version) | |
677 | return -EINVAL; | |
678 | ||
679 | info->uio_dev = NULL; | |
680 | ||
681 | ret = init_uio_class(); | |
682 | if (ret) | |
683 | return ret; | |
684 | ||
685 | idev = kzalloc(sizeof(*idev), GFP_KERNEL); | |
686 | if (!idev) { | |
687 | ret = -ENOMEM; | |
688 | goto err_kzalloc; | |
689 | } | |
690 | ||
691 | idev->owner = owner; | |
692 | idev->info = info; | |
693 | init_waitqueue_head(&idev->wait); | |
694 | atomic_set(&idev->event, 0); | |
695 | ||
696 | ret = uio_get_minor(idev); | |
697 | if (ret) | |
698 | goto err_get_minor; | |
699 | ||
a9b12619 GKH |
700 | idev->dev = device_create(uio_class->class, parent, |
701 | MKDEV(uio_major, idev->minor), idev, | |
702 | "uio%d", idev->minor); | |
beafc54c HK |
703 | if (IS_ERR(idev->dev)) { |
704 | printk(KERN_ERR "UIO: device register failed\n"); | |
705 | ret = PTR_ERR(idev->dev); | |
706 | goto err_device_create; | |
707 | } | |
beafc54c HK |
708 | |
709 | ret = uio_dev_add_attributes(idev); | |
710 | if (ret) | |
711 | goto err_uio_dev_add_attributes; | |
712 | ||
713 | info->uio_dev = idev; | |
714 | ||
715 | if (idev->info->irq >= 0) { | |
716 | ret = request_irq(idev->info->irq, uio_interrupt, | |
717 | idev->info->irq_flags, idev->info->name, idev); | |
718 | if (ret) | |
719 | goto err_request_irq; | |
720 | } | |
721 | ||
722 | return 0; | |
723 | ||
724 | err_request_irq: | |
725 | uio_dev_del_attributes(idev); | |
726 | err_uio_dev_add_attributes: | |
727 | device_destroy(uio_class->class, MKDEV(uio_major, idev->minor)); | |
728 | err_device_create: | |
729 | uio_free_minor(idev); | |
730 | err_get_minor: | |
731 | kfree(idev); | |
732 | err_kzalloc: | |
733 | uio_class_destroy(); | |
734 | return ret; | |
735 | } | |
736 | EXPORT_SYMBOL_GPL(__uio_register_device); | |
737 | ||
738 | /** | |
739 | * uio_unregister_device - unregister a industrial IO device | |
740 | * @info: UIO device capabilities | |
741 | * | |
742 | */ | |
743 | void uio_unregister_device(struct uio_info *info) | |
744 | { | |
745 | struct uio_device *idev; | |
746 | ||
747 | if (!info || !info->uio_dev) | |
748 | return; | |
749 | ||
750 | idev = info->uio_dev; | |
751 | ||
752 | uio_free_minor(idev); | |
753 | ||
754 | if (info->irq >= 0) | |
755 | free_irq(info->irq, idev); | |
756 | ||
757 | uio_dev_del_attributes(idev); | |
758 | ||
759 | dev_set_drvdata(idev->dev, NULL); | |
760 | device_destroy(uio_class->class, MKDEV(uio_major, idev->minor)); | |
761 | kfree(idev); | |
762 | uio_class_destroy(); | |
763 | ||
764 | return; | |
765 | } | |
766 | EXPORT_SYMBOL_GPL(uio_unregister_device); | |
767 | ||
768 | static int __init uio_init(void) | |
769 | { | |
770 | return 0; | |
771 | } | |
772 | ||
773 | static void __exit uio_exit(void) | |
774 | { | |
775 | } | |
776 | ||
777 | module_init(uio_init) | |
778 | module_exit(uio_exit) | |
779 | MODULE_LICENSE("GPL v2"); |