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