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/sched.h>
  15. #include <linux/slab.h>
  16. #include <linux/module.h>
  17. #include <linux/init.h>
  18. #include <linux/input.h>
  19. #include <linux/major.h>
  20. #include <linux/device.h>
  21. #include "input-compat.h"
  22. struct evdev {
  23. int exist;
  24. int open;
  25. int minor;
  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. if (event->type == EV_SYN)
  56. kill_fasync(&client->fasync, SIGIO, POLL_IN);
  57. }
  58. /*
  59. * Pass incoming event to all connected clients.
  60. */
  61. static void evdev_event(struct input_handle *handle,
  62. unsigned int type, unsigned int code, int value)
  63. {
  64. struct evdev *evdev = handle->private;
  65. struct evdev_client *client;
  66. struct input_event event;
  67. do_gettimeofday(&event.time);
  68. event.type = type;
  69. event.code = code;
  70. event.value = value;
  71. rcu_read_lock();
  72. client = rcu_dereference(evdev->grab);
  73. if (client)
  74. evdev_pass_event(client, &event);
  75. else
  76. list_for_each_entry_rcu(client, &evdev->client_list, node)
  77. evdev_pass_event(client, &event);
  78. rcu_read_unlock();
  79. wake_up_interruptible(&evdev->wait);
  80. }
  81. static int evdev_fasync(int fd, struct file *file, int on)
  82. {
  83. struct evdev_client *client = file->private_data;
  84. return fasync_helper(fd, file, on, &client->fasync);
  85. }
  86. static int evdev_flush(struct file *file, fl_owner_t id)
  87. {
  88. struct evdev_client *client = file->private_data;
  89. struct evdev *evdev = client->evdev;
  90. int retval;
  91. retval = mutex_lock_interruptible(&evdev->mutex);
  92. if (retval)
  93. return retval;
  94. if (!evdev->exist)
  95. retval = -ENODEV;
  96. else
  97. retval = input_flush_device(&evdev->handle, file);
  98. mutex_unlock(&evdev->mutex);
  99. return retval;
  100. }
  101. static void evdev_free(struct device *dev)
  102. {
  103. struct evdev *evdev = container_of(dev, struct evdev, dev);
  104. input_put_device(evdev->handle.dev);
  105. kfree(evdev);
  106. }
  107. /*
  108. * Grabs an event device (along with underlying input device).
  109. * This function is called with evdev->mutex taken.
  110. */
  111. static int evdev_grab(struct evdev *evdev, struct evdev_client *client)
  112. {
  113. int error;
  114. if (evdev->grab)
  115. return -EBUSY;
  116. error = input_grab_device(&evdev->handle);
  117. if (error)
  118. return error;
  119. rcu_assign_pointer(evdev->grab, client);
  120. synchronize_rcu();
  121. return 0;
  122. }
  123. static int evdev_ungrab(struct evdev *evdev, struct evdev_client *client)
  124. {
  125. if (evdev->grab != client)
  126. return -EINVAL;
  127. rcu_assign_pointer(evdev->grab, NULL);
  128. synchronize_rcu();
  129. input_release_device(&evdev->handle);
  130. return 0;
  131. }
  132. static void evdev_attach_client(struct evdev *evdev,
  133. struct evdev_client *client)
  134. {
  135. spin_lock(&evdev->client_lock);
  136. list_add_tail_rcu(&client->node, &evdev->client_list);
  137. spin_unlock(&evdev->client_lock);
  138. synchronize_rcu();
  139. }
  140. static void evdev_detach_client(struct evdev *evdev,
  141. struct evdev_client *client)
  142. {
  143. spin_lock(&evdev->client_lock);
  144. list_del_rcu(&client->node);
  145. spin_unlock(&evdev->client_lock);
  146. synchronize_rcu();
  147. }
  148. static int evdev_open_device(struct evdev *evdev)
  149. {
  150. int retval;
  151. retval = mutex_lock_interruptible(&evdev->mutex);
  152. if (retval)
  153. return retval;
  154. if (!evdev->exist)
  155. retval = -ENODEV;
  156. else if (!evdev->open++) {
  157. retval = input_open_device(&evdev->handle);
  158. if (retval)
  159. evdev->open--;
  160. }
  161. mutex_unlock(&evdev->mutex);
  162. return retval;
  163. }
  164. static void evdev_close_device(struct evdev *evdev)
  165. {
  166. mutex_lock(&evdev->mutex);
  167. if (evdev->exist && !--evdev->open)
  168. input_close_device(&evdev->handle);
  169. mutex_unlock(&evdev->mutex);
  170. }
  171. /*
  172. * Wake up users waiting for IO so they can disconnect from
  173. * dead device.
  174. */
  175. static void evdev_hangup(struct evdev *evdev)
  176. {
  177. struct evdev_client *client;
  178. spin_lock(&evdev->client_lock);
  179. list_for_each_entry(client, &evdev->client_list, node)
  180. kill_fasync(&client->fasync, SIGIO, POLL_HUP);
  181. spin_unlock(&evdev->client_lock);
  182. wake_up_interruptible(&evdev->wait);
  183. }
  184. static int evdev_release(struct inode *inode, struct file *file)
  185. {
  186. struct evdev_client *client = file->private_data;
  187. struct evdev *evdev = client->evdev;
  188. mutex_lock(&evdev->mutex);
  189. if (evdev->grab == client)
  190. evdev_ungrab(evdev, client);
  191. mutex_unlock(&evdev->mutex);
  192. evdev_detach_client(evdev, client);
  193. kfree(client);
  194. evdev_close_device(evdev);
  195. put_device(&evdev->dev);
  196. return 0;
  197. }
  198. static int evdev_open(struct inode *inode, struct file *file)
  199. {
  200. struct evdev *evdev;
  201. struct evdev_client *client;
  202. int i = iminor(inode) - EVDEV_MINOR_BASE;
  203. int error;
  204. if (i >= EVDEV_MINORS)
  205. return -ENODEV;
  206. error = mutex_lock_interruptible(&evdev_table_mutex);
  207. if (error)
  208. return error;
  209. evdev = evdev_table[i];
  210. if (evdev)
  211. get_device(&evdev->dev);
  212. mutex_unlock(&evdev_table_mutex);
  213. if (!evdev)
  214. return -ENODEV;
  215. client = kzalloc(sizeof(struct evdev_client), GFP_KERNEL);
  216. if (!client) {
  217. error = -ENOMEM;
  218. goto err_put_evdev;
  219. }
  220. spin_lock_init(&client->buffer_lock);
  221. client->evdev = evdev;
  222. evdev_attach_client(evdev, client);
  223. error = evdev_open_device(evdev);
  224. if (error)
  225. goto err_free_client;
  226. file->private_data = client;
  227. nonseekable_open(inode, file);
  228. return 0;
  229. err_free_client:
  230. evdev_detach_client(evdev, client);
  231. kfree(client);
  232. err_put_evdev:
  233. put_device(&evdev->dev);
  234. return error;
  235. }
  236. static ssize_t evdev_write(struct file *file, const char __user *buffer,
  237. size_t count, loff_t *ppos)
  238. {
  239. struct evdev_client *client = file->private_data;
  240. struct evdev *evdev = client->evdev;
  241. struct input_event event;
  242. int retval;
  243. retval = mutex_lock_interruptible(&evdev->mutex);
  244. if (retval)
  245. return retval;
  246. if (!evdev->exist) {
  247. retval = -ENODEV;
  248. goto out;
  249. }
  250. while (retval < count) {
  251. if (input_event_from_user(buffer + retval, &event)) {
  252. retval = -EFAULT;
  253. goto out;
  254. }
  255. input_inject_event(&evdev->handle,
  256. event.type, event.code, event.value);
  257. retval += input_event_size();
  258. }
  259. out:
  260. mutex_unlock(&evdev->mutex);
  261. return retval;
  262. }
  263. static int evdev_fetch_next_event(struct evdev_client *client,
  264. struct input_event *event)
  265. {
  266. int have_event;
  267. spin_lock_irq(&client->buffer_lock);
  268. have_event = client->head != client->tail;
  269. if (have_event) {
  270. *event = client->buffer[client->tail++];
  271. client->tail &= EVDEV_BUFFER_SIZE - 1;
  272. }
  273. spin_unlock_irq(&client->buffer_lock);
  274. return have_event;
  275. }
  276. static ssize_t evdev_read(struct file *file, char __user *buffer,
  277. size_t count, loff_t *ppos)
  278. {
  279. struct evdev_client *client = file->private_data;
  280. struct evdev *evdev = client->evdev;
  281. struct input_event event;
  282. int retval;
  283. if (count < input_event_size())
  284. return -EINVAL;
  285. if (client->head == client->tail && evdev->exist &&
  286. (file->f_flags & O_NONBLOCK))
  287. return -EAGAIN;
  288. retval = wait_event_interruptible(evdev->wait,
  289. client->head != client->tail || !evdev->exist);
  290. if (retval)
  291. return retval;
  292. if (!evdev->exist)
  293. return -ENODEV;
  294. while (retval + input_event_size() <= count &&
  295. evdev_fetch_next_event(client, &event)) {
  296. if (input_event_to_user(buffer + retval, &event))
  297. return -EFAULT;
  298. retval += input_event_size();
  299. }
  300. return retval;
  301. }
  302. /* No kernel lock - fine */
  303. static unsigned int evdev_poll(struct file *file, poll_table *wait)
  304. {
  305. struct evdev_client *client = file->private_data;
  306. struct evdev *evdev = client->evdev;
  307. poll_wait(file, &evdev->wait, wait);
  308. return ((client->head == client->tail) ? 0 : (POLLIN | POLLRDNORM)) |
  309. (evdev->exist ? 0 : (POLLHUP | POLLERR));
  310. }
  311. #ifdef CONFIG_COMPAT
  312. #define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8)
  313. #define BITS_TO_LONGS_COMPAT(x) ((((x) - 1) / BITS_PER_LONG_COMPAT) + 1)
  314. #ifdef __BIG_ENDIAN
  315. static int bits_to_user(unsigned long *bits, unsigned int maxbit,
  316. unsigned int maxlen, void __user *p, int compat)
  317. {
  318. int len, i;
  319. if (compat) {
  320. len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
  321. if (len > maxlen)
  322. len = maxlen;
  323. for (i = 0; i < len / sizeof(compat_long_t); i++)
  324. if (copy_to_user((compat_long_t __user *) p + i,
  325. (compat_long_t *) bits +
  326. i + 1 - ((i % 2) << 1),
  327. sizeof(compat_long_t)))
  328. return -EFAULT;
  329. } else {
  330. len = BITS_TO_LONGS(maxbit) * sizeof(long);
  331. if (len > maxlen)
  332. len = maxlen;
  333. if (copy_to_user(p, bits, len))
  334. return -EFAULT;
  335. }
  336. return len;
  337. }
  338. #else
  339. static int bits_to_user(unsigned long *bits, unsigned int maxbit,
  340. unsigned int maxlen, void __user *p, int compat)
  341. {
  342. int len = compat ?
  343. BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t) :
  344. BITS_TO_LONGS(maxbit) * sizeof(long);
  345. if (len > maxlen)
  346. len = maxlen;
  347. return copy_to_user(p, bits, len) ? -EFAULT : len;
  348. }
  349. #endif /* __BIG_ENDIAN */
  350. #else
  351. static int bits_to_user(unsigned long *bits, unsigned int maxbit,
  352. unsigned int maxlen, void __user *p, int compat)
  353. {
  354. int len = BITS_TO_LONGS(maxbit) * sizeof(long);
  355. if (len > maxlen)
  356. len = maxlen;
  357. return copy_to_user(p, bits, len) ? -EFAULT : len;
  358. }
  359. #endif /* CONFIG_COMPAT */
  360. static int str_to_user(const char *str, unsigned int maxlen, void __user *p)
  361. {
  362. int len;
  363. if (!str)
  364. return -ENOENT;
  365. len = strlen(str) + 1;
  366. if (len > maxlen)
  367. len = maxlen;
  368. return copy_to_user(p, str, len) ? -EFAULT : len;
  369. }
  370. #define OLD_KEY_MAX 0x1ff
  371. static int handle_eviocgbit(struct input_dev *dev, unsigned int cmd, void __user *p, int compat_mode)
  372. {
  373. static unsigned long keymax_warn_time;
  374. unsigned long *bits;
  375. int len;
  376. switch (_IOC_NR(cmd) & EV_MAX) {
  377. case 0: bits = dev->evbit; len = EV_MAX; break;
  378. case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
  379. case EV_REL: bits = dev->relbit; len = REL_MAX; break;
  380. case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
  381. case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break;
  382. case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
  383. case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
  384. case EV_FF: bits = dev->ffbit; len = FF_MAX; break;
  385. case EV_SW: bits = dev->swbit; len = SW_MAX; break;
  386. default: return -EINVAL;
  387. }
  388. /*
  389. * Work around bugs in userspace programs that like to do
  390. * EVIOCGBIT(EV_KEY, KEY_MAX) and not realize that 'len'
  391. * should be in bytes, not in bits.
  392. */
  393. if ((_IOC_NR(cmd) & EV_MAX) == EV_KEY && _IOC_SIZE(cmd) == OLD_KEY_MAX) {
  394. len = OLD_KEY_MAX;
  395. if (printk_timed_ratelimit(&keymax_warn_time, 10 * 1000))
  396. printk(KERN_WARNING
  397. "evdev.c(EVIOCGBIT): Suspicious buffer size %u, "
  398. "limiting output to %zu bytes. See "
  399. "http://userweb.kernel.org/~dtor/eviocgbit-bug.html\n",
  400. OLD_KEY_MAX,
  401. BITS_TO_LONGS(OLD_KEY_MAX) * sizeof(long));
  402. }
  403. return bits_to_user(bits, len, _IOC_SIZE(cmd), p, compat_mode);
  404. }
  405. #undef OLD_KEY_MAX
  406. static long evdev_do_ioctl(struct file *file, unsigned int cmd,
  407. void __user *p, int compat_mode)
  408. {
  409. struct evdev_client *client = file->private_data;
  410. struct evdev *evdev = client->evdev;
  411. struct input_dev *dev = evdev->handle.dev;
  412. struct input_absinfo abs;
  413. struct ff_effect effect;
  414. int __user *ip = (int __user *)p;
  415. unsigned int i, t, u, v;
  416. int error;
  417. switch (cmd) {
  418. case EVIOCGVERSION:
  419. return put_user(EV_VERSION, ip);
  420. case EVIOCGID:
  421. if (copy_to_user(p, &dev->id, sizeof(struct input_id)))
  422. return -EFAULT;
  423. return 0;
  424. case EVIOCGREP:
  425. if (!test_bit(EV_REP, dev->evbit))
  426. return -ENOSYS;
  427. if (put_user(dev->rep[REP_DELAY], ip))
  428. return -EFAULT;
  429. if (put_user(dev->rep[REP_PERIOD], ip + 1))
  430. return -EFAULT;
  431. return 0;
  432. case EVIOCSREP:
  433. if (!test_bit(EV_REP, dev->evbit))
  434. return -ENOSYS;
  435. if (get_user(u, ip))
  436. return -EFAULT;
  437. if (get_user(v, ip + 1))
  438. return -EFAULT;
  439. input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u);
  440. input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v);
  441. return 0;
  442. case EVIOCGKEYCODE:
  443. if (get_user(t, ip))
  444. return -EFAULT;
  445. error = input_get_keycode(dev, t, &v);
  446. if (error)
  447. return error;
  448. if (put_user(v, ip + 1))
  449. return -EFAULT;
  450. return 0;
  451. case EVIOCSKEYCODE:
  452. if (get_user(t, ip) || get_user(v, ip + 1))
  453. return -EFAULT;
  454. return input_set_keycode(dev, t, v);
  455. case EVIOCRMFF:
  456. return input_ff_erase(dev, (int)(unsigned long) p, file);
  457. case EVIOCGEFFECTS:
  458. i = test_bit(EV_FF, dev->evbit) ?
  459. dev->ff->max_effects : 0;
  460. if (put_user(i, ip))
  461. return -EFAULT;
  462. return 0;
  463. case EVIOCGRAB:
  464. if (p)
  465. return evdev_grab(evdev, client);
  466. else
  467. return evdev_ungrab(evdev, client);
  468. default:
  469. if (_IOC_TYPE(cmd) != 'E')
  470. return -EINVAL;
  471. if (_IOC_DIR(cmd) == _IOC_READ) {
  472. if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0)))
  473. return handle_eviocgbit(dev, cmd, p, compat_mode);
  474. if (_IOC_NR(cmd) == _IOC_NR(EVIOCGKEY(0)))
  475. return bits_to_user(dev->key, KEY_MAX, _IOC_SIZE(cmd),
  476. p, compat_mode);
  477. if (_IOC_NR(cmd) == _IOC_NR(EVIOCGLED(0)))
  478. return bits_to_user(dev->led, LED_MAX, _IOC_SIZE(cmd),
  479. p, compat_mode);
  480. if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSND(0)))
  481. return bits_to_user(dev->snd, SND_MAX, _IOC_SIZE(cmd),
  482. p, compat_mode);
  483. if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSW(0)))
  484. return bits_to_user(dev->sw, SW_MAX, _IOC_SIZE(cmd),
  485. p, compat_mode);
  486. if (_IOC_NR(cmd) == _IOC_NR(EVIOCGNAME(0)))
  487. return str_to_user(dev->name, _IOC_SIZE(cmd), p);
  488. if (_IOC_NR(cmd) == _IOC_NR(EVIOCGPHYS(0)))
  489. return str_to_user(dev->phys, _IOC_SIZE(cmd), p);
  490. if (_IOC_NR(cmd) == _IOC_NR(EVIOCGUNIQ(0)))
  491. return str_to_user(dev->uniq, _IOC_SIZE(cmd), p);
  492. if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {
  493. t = _IOC_NR(cmd) & ABS_MAX;
  494. abs.value = dev->abs[t];
  495. abs.minimum = dev->absmin[t];
  496. abs.maximum = dev->absmax[t];
  497. abs.fuzz = dev->absfuzz[t];
  498. abs.flat = dev->absflat[t];
  499. abs.resolution = dev->absres[t];
  500. if (copy_to_user(p, &abs, min_t(size_t,
  501. _IOC_SIZE(cmd),
  502. sizeof(struct input_absinfo))))
  503. return -EFAULT;
  504. return 0;
  505. }
  506. }
  507. if (_IOC_DIR(cmd) == _IOC_WRITE) {
  508. if (_IOC_NR(cmd) == _IOC_NR(EVIOCSFF)) {
  509. if (input_ff_effect_from_user(p, _IOC_SIZE(cmd), &effect))
  510. return -EFAULT;
  511. error = input_ff_upload(dev, &effect, file);
  512. if (put_user(effect.id, &(((struct ff_effect __user *)p)->id)))
  513. return -EFAULT;
  514. return error;
  515. }
  516. if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) {
  517. t = _IOC_NR(cmd) & ABS_MAX;
  518. if (copy_from_user(&abs, p, min_t(size_t,
  519. _IOC_SIZE(cmd),
  520. sizeof(struct input_absinfo))))
  521. return -EFAULT;
  522. /*
  523. * Take event lock to ensure that we are not
  524. * changing device parameters in the middle
  525. * of event.
  526. */
  527. spin_lock_irq(&dev->event_lock);
  528. dev->abs[t] = abs.value;
  529. dev->absmin[t] = abs.minimum;
  530. dev->absmax[t] = abs.maximum;
  531. dev->absfuzz[t] = abs.fuzz;
  532. dev->absflat[t] = abs.flat;
  533. dev->absres[t] = _IOC_SIZE(cmd) < sizeof(struct input_absinfo) ?
  534. 0 : abs.resolution;
  535. spin_unlock_irq(&dev->event_lock);
  536. return 0;
  537. }
  538. }
  539. }
  540. return -EINVAL;
  541. }
  542. static long evdev_ioctl_handler(struct file *file, unsigned int cmd,
  543. void __user *p, int compat_mode)
  544. {
  545. struct evdev_client *client = file->private_data;
  546. struct evdev *evdev = client->evdev;
  547. int retval;
  548. retval = mutex_lock_interruptible(&evdev->mutex);
  549. if (retval)
  550. return retval;
  551. if (!evdev->exist) {
  552. retval = -ENODEV;
  553. goto out;
  554. }
  555. retval = evdev_do_ioctl(file, cmd, p, compat_mode);
  556. out:
  557. mutex_unlock(&evdev->mutex);
  558. return retval;
  559. }
  560. static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
  561. {
  562. return evdev_ioctl_handler(file, cmd, (void __user *)arg, 0);
  563. }
  564. #ifdef CONFIG_COMPAT
  565. static long evdev_ioctl_compat(struct file *file,
  566. unsigned int cmd, unsigned long arg)
  567. {
  568. return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1);
  569. }
  570. #endif
  571. static const struct file_operations evdev_fops = {
  572. .owner = THIS_MODULE,
  573. .read = evdev_read,
  574. .write = evdev_write,
  575. .poll = evdev_poll,
  576. .open = evdev_open,
  577. .release = evdev_release,
  578. .unlocked_ioctl = evdev_ioctl,
  579. #ifdef CONFIG_COMPAT
  580. .compat_ioctl = evdev_ioctl_compat,
  581. #endif
  582. .fasync = evdev_fasync,
  583. .flush = evdev_flush
  584. };
  585. static int evdev_install_chrdev(struct evdev *evdev)
  586. {
  587. /*
  588. * No need to do any locking here as calls to connect and
  589. * disconnect are serialized by the input core
  590. */
  591. evdev_table[evdev->minor] = evdev;
  592. return 0;
  593. }
  594. static void evdev_remove_chrdev(struct evdev *evdev)
  595. {
  596. /*
  597. * Lock evdev table to prevent race with evdev_open()
  598. */
  599. mutex_lock(&evdev_table_mutex);
  600. evdev_table[evdev->minor] = NULL;
  601. mutex_unlock(&evdev_table_mutex);
  602. }
  603. /*
  604. * Mark device non-existent. This disables writes, ioctls and
  605. * prevents new users from opening the device. Already posted
  606. * blocking reads will stay, however new ones will fail.
  607. */
  608. static void evdev_mark_dead(struct evdev *evdev)
  609. {
  610. mutex_lock(&evdev->mutex);
  611. evdev->exist = 0;
  612. mutex_unlock(&evdev->mutex);
  613. }
  614. static void evdev_cleanup(struct evdev *evdev)
  615. {
  616. struct input_handle *handle = &evdev->handle;
  617. evdev_mark_dead(evdev);
  618. evdev_hangup(evdev);
  619. evdev_remove_chrdev(evdev);
  620. /* evdev is marked dead so no one else accesses evdev->open */
  621. if (evdev->open) {
  622. input_flush_device(handle, NULL);
  623. input_close_device(handle);
  624. }
  625. }
  626. /*
  627. * Create new evdev device. Note that input core serializes calls
  628. * to connect and disconnect so we don't need to lock evdev_table here.
  629. */
  630. static int evdev_connect(struct input_handler *handler, struct input_dev *dev,
  631. const struct input_device_id *id)
  632. {
  633. struct evdev *evdev;
  634. int minor;
  635. int error;
  636. for (minor = 0; minor < EVDEV_MINORS; minor++)
  637. if (!evdev_table[minor])
  638. break;
  639. if (minor == EVDEV_MINORS) {
  640. printk(KERN_ERR "evdev: no more free evdev devices\n");
  641. return -ENFILE;
  642. }
  643. evdev = kzalloc(sizeof(struct evdev), GFP_KERNEL);
  644. if (!evdev)
  645. return -ENOMEM;
  646. INIT_LIST_HEAD(&evdev->client_list);
  647. spin_lock_init(&evdev->client_lock);
  648. mutex_init(&evdev->mutex);
  649. init_waitqueue_head(&evdev->wait);
  650. dev_set_name(&evdev->dev, "event%d", minor);
  651. evdev->exist = 1;
  652. evdev->minor = minor;
  653. evdev->handle.dev = input_get_device(dev);
  654. evdev->handle.name = dev_name(&evdev->dev);
  655. evdev->handle.handler = handler;
  656. evdev->handle.private = evdev;
  657. evdev->dev.devt = MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + minor);
  658. evdev->dev.class = &input_class;
  659. evdev->dev.parent = &dev->dev;
  660. evdev->dev.release = evdev_free;
  661. device_initialize(&evdev->dev);
  662. error = input_register_handle(&evdev->handle);
  663. if (error)
  664. goto err_free_evdev;
  665. error = evdev_install_chrdev(evdev);
  666. if (error)
  667. goto err_unregister_handle;
  668. error = device_add(&evdev->dev);
  669. if (error)
  670. goto err_cleanup_evdev;
  671. return 0;
  672. err_cleanup_evdev:
  673. evdev_cleanup(evdev);
  674. err_unregister_handle:
  675. input_unregister_handle(&evdev->handle);
  676. err_free_evdev:
  677. put_device(&evdev->dev);
  678. return error;
  679. }
  680. static void evdev_disconnect(struct input_handle *handle)
  681. {
  682. struct evdev *evdev = handle->private;
  683. device_del(&evdev->dev);
  684. evdev_cleanup(evdev);
  685. input_unregister_handle(handle);
  686. put_device(&evdev->dev);
  687. }
  688. static const struct input_device_id evdev_ids[] = {
  689. { .driver_info = 1 }, /* Matches all devices */
  690. { }, /* Terminating zero entry */
  691. };
  692. MODULE_DEVICE_TABLE(input, evdev_ids);
  693. static struct input_handler evdev_handler = {
  694. .event = evdev_event,
  695. .connect = evdev_connect,
  696. .disconnect = evdev_disconnect,
  697. .fops = &evdev_fops,
  698. .minor = EVDEV_MINOR_BASE,
  699. .name = "evdev",
  700. .id_table = evdev_ids,
  701. };
  702. static int __init evdev_init(void)
  703. {
  704. return input_register_handler(&evdev_handler);
  705. }
  706. static void __exit evdev_exit(void)
  707. {
  708. input_unregister_handler(&evdev_handler);
  709. }
  710. module_init(evdev_init);
  711. module_exit(evdev_exit);
  712. MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
  713. MODULE_DESCRIPTION("Input driver event char devices");
  714. MODULE_LICENSE("GPL");