evdev.c 20 KB

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  1. /*
  2. * Event char devices, giving access to raw input device events.
  3. *
  4. * Copyright (c) 1999-2002 Vojtech Pavlik
  5. *
  6. * This program is free software; you can redistribute it and/or modify it
  7. * under the terms of the GNU General Public License version 2 as published by
  8. * the Free Software Foundation.
  9. */
  10. #define EVDEV_MINOR_BASE 64
  11. #define EVDEV_MINORS 32
  12. #define EVDEV_BUFFER_SIZE 64
  13. #include <linux/poll.h>
  14. #include <linux/slab.h>
  15. #include <linux/module.h>
  16. #include <linux/init.h>
  17. #include <linux/input.h>
  18. #include <linux/major.h>
  19. #include <linux/device.h>
  20. #include "input-compat.h"
  21. struct evdev {
  22. int exist;
  23. int open;
  24. int minor;
  25. char name[16];
  26. struct input_handle handle;
  27. wait_queue_head_t wait;
  28. struct evdev_client *grab;
  29. struct list_head client_list;
  30. spinlock_t client_lock; /* protects client_list */
  31. struct mutex mutex;
  32. struct device dev;
  33. };
  34. struct evdev_client {
  35. struct input_event buffer[EVDEV_BUFFER_SIZE];
  36. int head;
  37. int tail;
  38. spinlock_t buffer_lock; /* protects access to buffer, head and tail */
  39. struct fasync_struct *fasync;
  40. struct evdev *evdev;
  41. struct list_head node;
  42. };
  43. static struct evdev *evdev_table[EVDEV_MINORS];
  44. static DEFINE_MUTEX(evdev_table_mutex);
  45. static void evdev_pass_event(struct evdev_client *client,
  46. struct input_event *event)
  47. {
  48. /*
  49. * Interrupts are disabled, just acquire the lock
  50. */
  51. spin_lock(&client->buffer_lock);
  52. client->buffer[client->head++] = *event;
  53. client->head &= EVDEV_BUFFER_SIZE - 1;
  54. spin_unlock(&client->buffer_lock);
  55. kill_fasync(&client->fasync, SIGIO, POLL_IN);
  56. }
  57. /*
  58. * Pass incoming event to all connected clients.
  59. */
  60. static void evdev_event(struct input_handle *handle,
  61. unsigned int type, unsigned int code, int value)
  62. {
  63. struct evdev *evdev = handle->private;
  64. struct evdev_client *client;
  65. struct input_event event;
  66. do_gettimeofday(&event.time);
  67. event.type = type;
  68. event.code = code;
  69. event.value = value;
  70. rcu_read_lock();
  71. client = rcu_dereference(evdev->grab);
  72. if (client)
  73. evdev_pass_event(client, &event);
  74. else
  75. list_for_each_entry_rcu(client, &evdev->client_list, node)
  76. evdev_pass_event(client, &event);
  77. rcu_read_unlock();
  78. wake_up_interruptible(&evdev->wait);
  79. }
  80. static int evdev_fasync(int fd, struct file *file, int on)
  81. {
  82. struct evdev_client *client = file->private_data;
  83. return fasync_helper(fd, file, on, &client->fasync);
  84. }
  85. static int evdev_flush(struct file *file, fl_owner_t id)
  86. {
  87. struct evdev_client *client = file->private_data;
  88. struct evdev *evdev = client->evdev;
  89. int retval;
  90. retval = mutex_lock_interruptible(&evdev->mutex);
  91. if (retval)
  92. return retval;
  93. if (!evdev->exist)
  94. retval = -ENODEV;
  95. else
  96. retval = input_flush_device(&evdev->handle, file);
  97. mutex_unlock(&evdev->mutex);
  98. return retval;
  99. }
  100. static void evdev_free(struct device *dev)
  101. {
  102. struct evdev *evdev = container_of(dev, struct evdev, dev);
  103. input_put_device(evdev->handle.dev);
  104. kfree(evdev);
  105. }
  106. /*
  107. * Grabs an event device (along with underlying input device).
  108. * This function is called with evdev->mutex taken.
  109. */
  110. static int evdev_grab(struct evdev *evdev, struct evdev_client *client)
  111. {
  112. int error;
  113. if (evdev->grab)
  114. return -EBUSY;
  115. error = input_grab_device(&evdev->handle);
  116. if (error)
  117. return error;
  118. rcu_assign_pointer(evdev->grab, client);
  119. synchronize_rcu();
  120. return 0;
  121. }
  122. static int evdev_ungrab(struct evdev *evdev, struct evdev_client *client)
  123. {
  124. if (evdev->grab != client)
  125. return -EINVAL;
  126. rcu_assign_pointer(evdev->grab, NULL);
  127. synchronize_rcu();
  128. input_release_device(&evdev->handle);
  129. return 0;
  130. }
  131. static void evdev_attach_client(struct evdev *evdev,
  132. struct evdev_client *client)
  133. {
  134. spin_lock(&evdev->client_lock);
  135. list_add_tail_rcu(&client->node, &evdev->client_list);
  136. spin_unlock(&evdev->client_lock);
  137. synchronize_rcu();
  138. }
  139. static void evdev_detach_client(struct evdev *evdev,
  140. struct evdev_client *client)
  141. {
  142. spin_lock(&evdev->client_lock);
  143. list_del_rcu(&client->node);
  144. spin_unlock(&evdev->client_lock);
  145. synchronize_rcu();
  146. }
  147. static int evdev_open_device(struct evdev *evdev)
  148. {
  149. int retval;
  150. retval = mutex_lock_interruptible(&evdev->mutex);
  151. if (retval)
  152. return retval;
  153. if (!evdev->exist)
  154. retval = -ENODEV;
  155. else if (!evdev->open++) {
  156. retval = input_open_device(&evdev->handle);
  157. if (retval)
  158. evdev->open--;
  159. }
  160. mutex_unlock(&evdev->mutex);
  161. return retval;
  162. }
  163. static void evdev_close_device(struct evdev *evdev)
  164. {
  165. mutex_lock(&evdev->mutex);
  166. if (evdev->exist && !--evdev->open)
  167. input_close_device(&evdev->handle);
  168. mutex_unlock(&evdev->mutex);
  169. }
  170. /*
  171. * Wake up users waiting for IO so they can disconnect from
  172. * dead device.
  173. */
  174. static void evdev_hangup(struct evdev *evdev)
  175. {
  176. struct evdev_client *client;
  177. spin_lock(&evdev->client_lock);
  178. list_for_each_entry(client, &evdev->client_list, node)
  179. kill_fasync(&client->fasync, SIGIO, POLL_HUP);
  180. spin_unlock(&evdev->client_lock);
  181. wake_up_interruptible(&evdev->wait);
  182. }
  183. static int evdev_release(struct inode *inode, struct file *file)
  184. {
  185. struct evdev_client *client = file->private_data;
  186. struct evdev *evdev = client->evdev;
  187. mutex_lock(&evdev->mutex);
  188. if (evdev->grab == client)
  189. evdev_ungrab(evdev, client);
  190. mutex_unlock(&evdev->mutex);
  191. evdev_detach_client(evdev, client);
  192. kfree(client);
  193. evdev_close_device(evdev);
  194. put_device(&evdev->dev);
  195. return 0;
  196. }
  197. static int evdev_open(struct inode *inode, struct file *file)
  198. {
  199. struct evdev *evdev;
  200. struct evdev_client *client;
  201. int i = iminor(inode) - EVDEV_MINOR_BASE;
  202. int error;
  203. if (i >= EVDEV_MINORS)
  204. return -ENODEV;
  205. error = mutex_lock_interruptible(&evdev_table_mutex);
  206. if (error)
  207. return error;
  208. evdev = evdev_table[i];
  209. if (evdev)
  210. get_device(&evdev->dev);
  211. mutex_unlock(&evdev_table_mutex);
  212. if (!evdev)
  213. return -ENODEV;
  214. client = kzalloc(sizeof(struct evdev_client), GFP_KERNEL);
  215. if (!client) {
  216. error = -ENOMEM;
  217. goto err_put_evdev;
  218. }
  219. spin_lock_init(&client->buffer_lock);
  220. client->evdev = evdev;
  221. evdev_attach_client(evdev, client);
  222. error = evdev_open_device(evdev);
  223. if (error)
  224. goto err_free_client;
  225. file->private_data = client;
  226. return 0;
  227. err_free_client:
  228. evdev_detach_client(evdev, client);
  229. kfree(client);
  230. err_put_evdev:
  231. put_device(&evdev->dev);
  232. return error;
  233. }
  234. static ssize_t evdev_write(struct file *file, const char __user *buffer,
  235. size_t count, loff_t *ppos)
  236. {
  237. struct evdev_client *client = file->private_data;
  238. struct evdev *evdev = client->evdev;
  239. struct input_event event;
  240. int retval;
  241. retval = mutex_lock_interruptible(&evdev->mutex);
  242. if (retval)
  243. return retval;
  244. if (!evdev->exist) {
  245. retval = -ENODEV;
  246. goto out;
  247. }
  248. while (retval < count) {
  249. if (input_event_from_user(buffer + retval, &event)) {
  250. retval = -EFAULT;
  251. goto out;
  252. }
  253. input_inject_event(&evdev->handle,
  254. event.type, event.code, event.value);
  255. retval += input_event_size();
  256. }
  257. out:
  258. mutex_unlock(&evdev->mutex);
  259. return retval;
  260. }
  261. static int evdev_fetch_next_event(struct evdev_client *client,
  262. struct input_event *event)
  263. {
  264. int have_event;
  265. spin_lock_irq(&client->buffer_lock);
  266. have_event = client->head != client->tail;
  267. if (have_event) {
  268. *event = client->buffer[client->tail++];
  269. client->tail &= EVDEV_BUFFER_SIZE - 1;
  270. }
  271. spin_unlock_irq(&client->buffer_lock);
  272. return have_event;
  273. }
  274. static ssize_t evdev_read(struct file *file, char __user *buffer,
  275. size_t count, loff_t *ppos)
  276. {
  277. struct evdev_client *client = file->private_data;
  278. struct evdev *evdev = client->evdev;
  279. struct input_event event;
  280. int retval;
  281. if (count < input_event_size())
  282. return -EINVAL;
  283. if (client->head == client->tail && evdev->exist &&
  284. (file->f_flags & O_NONBLOCK))
  285. return -EAGAIN;
  286. retval = wait_event_interruptible(evdev->wait,
  287. client->head != client->tail || !evdev->exist);
  288. if (retval)
  289. return retval;
  290. if (!evdev->exist)
  291. return -ENODEV;
  292. while (retval + input_event_size() <= count &&
  293. evdev_fetch_next_event(client, &event)) {
  294. if (input_event_to_user(buffer + retval, &event))
  295. return -EFAULT;
  296. retval += input_event_size();
  297. }
  298. return retval;
  299. }
  300. /* No kernel lock - fine */
  301. static unsigned int evdev_poll(struct file *file, poll_table *wait)
  302. {
  303. struct evdev_client *client = file->private_data;
  304. struct evdev *evdev = client->evdev;
  305. poll_wait(file, &evdev->wait, wait);
  306. return ((client->head == client->tail) ? 0 : (POLLIN | POLLRDNORM)) |
  307. (evdev->exist ? 0 : (POLLHUP | POLLERR));
  308. }
  309. #ifdef CONFIG_COMPAT
  310. #define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8)
  311. #define BITS_TO_LONGS_COMPAT(x) ((((x) - 1) / BITS_PER_LONG_COMPAT) + 1)
  312. #ifdef __BIG_ENDIAN
  313. static int bits_to_user(unsigned long *bits, unsigned int maxbit,
  314. unsigned int maxlen, void __user *p, int compat)
  315. {
  316. int len, i;
  317. if (compat) {
  318. len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
  319. if (len > maxlen)
  320. len = maxlen;
  321. for (i = 0; i < len / sizeof(compat_long_t); i++)
  322. if (copy_to_user((compat_long_t __user *) p + i,
  323. (compat_long_t *) bits +
  324. i + 1 - ((i % 2) << 1),
  325. sizeof(compat_long_t)))
  326. return -EFAULT;
  327. } else {
  328. len = BITS_TO_LONGS(maxbit) * sizeof(long);
  329. if (len > maxlen)
  330. len = maxlen;
  331. if (copy_to_user(p, bits, len))
  332. return -EFAULT;
  333. }
  334. return len;
  335. }
  336. #else
  337. static int bits_to_user(unsigned long *bits, unsigned int maxbit,
  338. unsigned int maxlen, void __user *p, int compat)
  339. {
  340. int len = compat ?
  341. BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t) :
  342. BITS_TO_LONGS(maxbit) * sizeof(long);
  343. if (len > maxlen)
  344. len = maxlen;
  345. return copy_to_user(p, bits, len) ? -EFAULT : len;
  346. }
  347. #endif /* __BIG_ENDIAN */
  348. #else
  349. static int bits_to_user(unsigned long *bits, unsigned int maxbit,
  350. unsigned int maxlen, void __user *p, int compat)
  351. {
  352. int len = BITS_TO_LONGS(maxbit) * sizeof(long);
  353. if (len > maxlen)
  354. len = maxlen;
  355. return copy_to_user(p, bits, len) ? -EFAULT : len;
  356. }
  357. #endif /* CONFIG_COMPAT */
  358. static int str_to_user(const char *str, unsigned int maxlen, void __user *p)
  359. {
  360. int len;
  361. if (!str)
  362. return -ENOENT;
  363. len = strlen(str) + 1;
  364. if (len > maxlen)
  365. len = maxlen;
  366. return copy_to_user(p, str, len) ? -EFAULT : len;
  367. }
  368. #define OLD_KEY_MAX 0x1ff
  369. static int handle_eviocgbit(struct input_dev *dev, unsigned int cmd, void __user *p, int compat_mode)
  370. {
  371. static unsigned long keymax_warn_time;
  372. unsigned long *bits;
  373. int len;
  374. switch (_IOC_NR(cmd) & EV_MAX) {
  375. case 0: bits = dev->evbit; len = EV_MAX; break;
  376. case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
  377. case EV_REL: bits = dev->relbit; len = REL_MAX; break;
  378. case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
  379. case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break;
  380. case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
  381. case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
  382. case EV_FF: bits = dev->ffbit; len = FF_MAX; break;
  383. case EV_SW: bits = dev->swbit; len = SW_MAX; break;
  384. default: return -EINVAL;
  385. }
  386. /*
  387. * Work around bugs in userspace programs that like to do
  388. * EVIOCGBIT(EV_KEY, KEY_MAX) and not realize that 'len'
  389. * should be in bytes, not in bits.
  390. */
  391. if ((_IOC_NR(cmd) & EV_MAX) == EV_KEY && _IOC_SIZE(cmd) == OLD_KEY_MAX) {
  392. len = OLD_KEY_MAX;
  393. if (printk_timed_ratelimit(&keymax_warn_time, 10 * 1000))
  394. printk(KERN_WARNING
  395. "evdev.c(EVIOCGBIT): Suspicious buffer size %u, "
  396. "limiting output to %zu bytes. See "
  397. "http://userweb.kernel.org/~dtor/eviocgbit-bug.html\n",
  398. OLD_KEY_MAX,
  399. BITS_TO_LONGS(OLD_KEY_MAX) * sizeof(long));
  400. }
  401. return bits_to_user(bits, len, _IOC_SIZE(cmd), p, compat_mode);
  402. }
  403. #undef OLD_KEY_MAX
  404. static long evdev_do_ioctl(struct file *file, unsigned int cmd,
  405. void __user *p, int compat_mode)
  406. {
  407. struct evdev_client *client = file->private_data;
  408. struct evdev *evdev = client->evdev;
  409. struct input_dev *dev = evdev->handle.dev;
  410. struct input_absinfo abs;
  411. struct ff_effect effect;
  412. int __user *ip = (int __user *)p;
  413. int i, t, u, v;
  414. int error;
  415. switch (cmd) {
  416. case EVIOCGVERSION:
  417. return put_user(EV_VERSION, ip);
  418. case EVIOCGID:
  419. if (copy_to_user(p, &dev->id, sizeof(struct input_id)))
  420. return -EFAULT;
  421. return 0;
  422. case EVIOCGREP:
  423. if (!test_bit(EV_REP, dev->evbit))
  424. return -ENOSYS;
  425. if (put_user(dev->rep[REP_DELAY], ip))
  426. return -EFAULT;
  427. if (put_user(dev->rep[REP_PERIOD], ip + 1))
  428. return -EFAULT;
  429. return 0;
  430. case EVIOCSREP:
  431. if (!test_bit(EV_REP, dev->evbit))
  432. return -ENOSYS;
  433. if (get_user(u, ip))
  434. return -EFAULT;
  435. if (get_user(v, ip + 1))
  436. return -EFAULT;
  437. input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u);
  438. input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v);
  439. return 0;
  440. case EVIOCGKEYCODE:
  441. if (get_user(t, ip))
  442. return -EFAULT;
  443. error = input_get_keycode(dev, t, &v);
  444. if (error)
  445. return error;
  446. if (put_user(v, ip + 1))
  447. return -EFAULT;
  448. return 0;
  449. case EVIOCSKEYCODE:
  450. if (get_user(t, ip) || get_user(v, ip + 1))
  451. return -EFAULT;
  452. return input_set_keycode(dev, t, v);
  453. case EVIOCRMFF:
  454. return input_ff_erase(dev, (int)(unsigned long) p, file);
  455. case EVIOCGEFFECTS:
  456. i = test_bit(EV_FF, dev->evbit) ?
  457. dev->ff->max_effects : 0;
  458. if (put_user(i, ip))
  459. return -EFAULT;
  460. return 0;
  461. case EVIOCGRAB:
  462. if (p)
  463. return evdev_grab(evdev, client);
  464. else
  465. return evdev_ungrab(evdev, client);
  466. default:
  467. if (_IOC_TYPE(cmd) != 'E')
  468. return -EINVAL;
  469. if (_IOC_DIR(cmd) == _IOC_READ) {
  470. if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0)))
  471. return handle_eviocgbit(dev, cmd, p, compat_mode);
  472. if (_IOC_NR(cmd) == _IOC_NR(EVIOCGKEY(0)))
  473. return bits_to_user(dev->key, KEY_MAX, _IOC_SIZE(cmd),
  474. p, compat_mode);
  475. if (_IOC_NR(cmd) == _IOC_NR(EVIOCGLED(0)))
  476. return bits_to_user(dev->led, LED_MAX, _IOC_SIZE(cmd),
  477. p, compat_mode);
  478. if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSND(0)))
  479. return bits_to_user(dev->snd, SND_MAX, _IOC_SIZE(cmd),
  480. p, compat_mode);
  481. if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSW(0)))
  482. return bits_to_user(dev->sw, SW_MAX, _IOC_SIZE(cmd),
  483. p, compat_mode);
  484. if (_IOC_NR(cmd) == _IOC_NR(EVIOCGNAME(0)))
  485. return str_to_user(dev->name, _IOC_SIZE(cmd), p);
  486. if (_IOC_NR(cmd) == _IOC_NR(EVIOCGPHYS(0)))
  487. return str_to_user(dev->phys, _IOC_SIZE(cmd), p);
  488. if (_IOC_NR(cmd) == _IOC_NR(EVIOCGUNIQ(0)))
  489. return str_to_user(dev->uniq, _IOC_SIZE(cmd), p);
  490. if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {
  491. t = _IOC_NR(cmd) & ABS_MAX;
  492. abs.value = dev->abs[t];
  493. abs.minimum = dev->absmin[t];
  494. abs.maximum = dev->absmax[t];
  495. abs.fuzz = dev->absfuzz[t];
  496. abs.flat = dev->absflat[t];
  497. if (copy_to_user(p, &abs, sizeof(struct input_absinfo)))
  498. return -EFAULT;
  499. return 0;
  500. }
  501. }
  502. if (_IOC_DIR(cmd) == _IOC_WRITE) {
  503. if (_IOC_NR(cmd) == _IOC_NR(EVIOCSFF)) {
  504. if (input_ff_effect_from_user(p, _IOC_SIZE(cmd), &effect))
  505. return -EFAULT;
  506. error = input_ff_upload(dev, &effect, file);
  507. if (put_user(effect.id, &(((struct ff_effect __user *)p)->id)))
  508. return -EFAULT;
  509. return error;
  510. }
  511. if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) {
  512. t = _IOC_NR(cmd) & ABS_MAX;
  513. if (copy_from_user(&abs, p,
  514. sizeof(struct input_absinfo)))
  515. return -EFAULT;
  516. /*
  517. * Take event lock to ensure that we are not
  518. * changing device parameters in the middle
  519. * of event.
  520. */
  521. spin_lock_irq(&dev->event_lock);
  522. dev->abs[t] = abs.value;
  523. dev->absmin[t] = abs.minimum;
  524. dev->absmax[t] = abs.maximum;
  525. dev->absfuzz[t] = abs.fuzz;
  526. dev->absflat[t] = abs.flat;
  527. spin_unlock_irq(&dev->event_lock);
  528. return 0;
  529. }
  530. }
  531. }
  532. return -EINVAL;
  533. }
  534. static long evdev_ioctl_handler(struct file *file, unsigned int cmd,
  535. void __user *p, int compat_mode)
  536. {
  537. struct evdev_client *client = file->private_data;
  538. struct evdev *evdev = client->evdev;
  539. int retval;
  540. retval = mutex_lock_interruptible(&evdev->mutex);
  541. if (retval)
  542. return retval;
  543. if (!evdev->exist) {
  544. retval = -ENODEV;
  545. goto out;
  546. }
  547. retval = evdev_do_ioctl(file, cmd, p, compat_mode);
  548. out:
  549. mutex_unlock(&evdev->mutex);
  550. return retval;
  551. }
  552. static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
  553. {
  554. return evdev_ioctl_handler(file, cmd, (void __user *)arg, 0);
  555. }
  556. #ifdef CONFIG_COMPAT
  557. static long evdev_ioctl_compat(struct file *file,
  558. unsigned int cmd, unsigned long arg)
  559. {
  560. return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1);
  561. }
  562. #endif
  563. static const struct file_operations evdev_fops = {
  564. .owner = THIS_MODULE,
  565. .read = evdev_read,
  566. .write = evdev_write,
  567. .poll = evdev_poll,
  568. .open = evdev_open,
  569. .release = evdev_release,
  570. .unlocked_ioctl = evdev_ioctl,
  571. #ifdef CONFIG_COMPAT
  572. .compat_ioctl = evdev_ioctl_compat,
  573. #endif
  574. .fasync = evdev_fasync,
  575. .flush = evdev_flush
  576. };
  577. static int evdev_install_chrdev(struct evdev *evdev)
  578. {
  579. /*
  580. * No need to do any locking here as calls to connect and
  581. * disconnect are serialized by the input core
  582. */
  583. evdev_table[evdev->minor] = evdev;
  584. return 0;
  585. }
  586. static void evdev_remove_chrdev(struct evdev *evdev)
  587. {
  588. /*
  589. * Lock evdev table to prevent race with evdev_open()
  590. */
  591. mutex_lock(&evdev_table_mutex);
  592. evdev_table[evdev->minor] = NULL;
  593. mutex_unlock(&evdev_table_mutex);
  594. }
  595. /*
  596. * Mark device non-existent. This disables writes, ioctls and
  597. * prevents new users from opening the device. Already posted
  598. * blocking reads will stay, however new ones will fail.
  599. */
  600. static void evdev_mark_dead(struct evdev *evdev)
  601. {
  602. mutex_lock(&evdev->mutex);
  603. evdev->exist = 0;
  604. mutex_unlock(&evdev->mutex);
  605. }
  606. static void evdev_cleanup(struct evdev *evdev)
  607. {
  608. struct input_handle *handle = &evdev->handle;
  609. evdev_mark_dead(evdev);
  610. evdev_hangup(evdev);
  611. evdev_remove_chrdev(evdev);
  612. /* evdev is marked dead so no one else accesses evdev->open */
  613. if (evdev->open) {
  614. input_flush_device(handle, NULL);
  615. input_close_device(handle);
  616. }
  617. }
  618. /*
  619. * Create new evdev device. Note that input core serializes calls
  620. * to connect and disconnect so we don't need to lock evdev_table here.
  621. */
  622. static int evdev_connect(struct input_handler *handler, struct input_dev *dev,
  623. const struct input_device_id *id)
  624. {
  625. struct evdev *evdev;
  626. int minor;
  627. int error;
  628. for (minor = 0; minor < EVDEV_MINORS; minor++)
  629. if (!evdev_table[minor])
  630. break;
  631. if (minor == EVDEV_MINORS) {
  632. printk(KERN_ERR "evdev: no more free evdev devices\n");
  633. return -ENFILE;
  634. }
  635. evdev = kzalloc(sizeof(struct evdev), GFP_KERNEL);
  636. if (!evdev)
  637. return -ENOMEM;
  638. INIT_LIST_HEAD(&evdev->client_list);
  639. spin_lock_init(&evdev->client_lock);
  640. mutex_init(&evdev->mutex);
  641. init_waitqueue_head(&evdev->wait);
  642. snprintf(evdev->name, sizeof(evdev->name), "event%d", minor);
  643. evdev->exist = 1;
  644. evdev->minor = minor;
  645. evdev->handle.dev = input_get_device(dev);
  646. evdev->handle.name = evdev->name;
  647. evdev->handle.handler = handler;
  648. evdev->handle.private = evdev;
  649. dev_set_name(&evdev->dev, evdev->name);
  650. evdev->dev.devt = MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + minor);
  651. evdev->dev.class = &input_class;
  652. evdev->dev.parent = &dev->dev;
  653. evdev->dev.release = evdev_free;
  654. device_initialize(&evdev->dev);
  655. error = input_register_handle(&evdev->handle);
  656. if (error)
  657. goto err_free_evdev;
  658. error = evdev_install_chrdev(evdev);
  659. if (error)
  660. goto err_unregister_handle;
  661. error = device_add(&evdev->dev);
  662. if (error)
  663. goto err_cleanup_evdev;
  664. return 0;
  665. err_cleanup_evdev:
  666. evdev_cleanup(evdev);
  667. err_unregister_handle:
  668. input_unregister_handle(&evdev->handle);
  669. err_free_evdev:
  670. put_device(&evdev->dev);
  671. return error;
  672. }
  673. static void evdev_disconnect(struct input_handle *handle)
  674. {
  675. struct evdev *evdev = handle->private;
  676. device_del(&evdev->dev);
  677. evdev_cleanup(evdev);
  678. input_unregister_handle(handle);
  679. put_device(&evdev->dev);
  680. }
  681. static const struct input_device_id evdev_ids[] = {
  682. { .driver_info = 1 }, /* Matches all devices */
  683. { }, /* Terminating zero entry */
  684. };
  685. MODULE_DEVICE_TABLE(input, evdev_ids);
  686. static struct input_handler evdev_handler = {
  687. .event = evdev_event,
  688. .connect = evdev_connect,
  689. .disconnect = evdev_disconnect,
  690. .fops = &evdev_fops,
  691. .minor = EVDEV_MINOR_BASE,
  692. .name = "evdev",
  693. .id_table = evdev_ids,
  694. };
  695. static int __init evdev_init(void)
  696. {
  697. return input_register_handler(&evdev_handler);
  698. }
  699. static void __exit evdev_exit(void)
  700. {
  701. input_unregister_handler(&evdev_handler);
  702. }
  703. module_init(evdev_init);
  704. module_exit(evdev_exit);
  705. MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
  706. MODULE_DESCRIPTION("Input driver event char devices");
  707. MODULE_LICENSE("GPL");