2 * Event char devices, giving access to raw input device events.
4 * Copyright (c) 1999-2002 Vojtech Pavlik
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.
11 #define EVDEV_MINOR_BASE 64
12 #define EVDEV_MINORS 32
13 #define EVDEV_MIN_BUFFER_SIZE 64U
14 #define EVDEV_BUF_PACKETS 8
16 #include <linux/poll.h>
17 #include <linux/sched.h>
18 #include <linux/slab.h>
19 #include <linux/module.h>
20 #include <linux/init.h>
21 #include <linux/input.h>
22 #include <linux/major.h>
23 #include <linux/device.h>
24 #include "input-compat.h"
30 struct input_handle handle;
31 wait_queue_head_t wait;
32 struct evdev_client *grab;
33 struct list_head client_list;
34 spinlock_t client_lock; /* protects client_list */
42 spinlock_t buffer_lock; /* protects access to buffer, head and tail */
43 struct fasync_struct *fasync;
45 struct list_head node;
47 struct input_event buffer[];
50 static struct evdev *evdev_table[EVDEV_MINORS];
51 static DEFINE_MUTEX(evdev_table_mutex);
53 static void evdev_pass_event(struct evdev_client *client,
54 struct input_event *event)
57 * Interrupts are disabled, just acquire the lock
59 spin_lock(&client->buffer_lock);
60 client->buffer[client->head++] = *event;
61 client->head &= client->bufsize - 1;
62 spin_unlock(&client->buffer_lock);
64 if (event->type == EV_SYN)
65 kill_fasync(&client->fasync, SIGIO, POLL_IN);
69 * Pass incoming event to all connected clients.
71 static void evdev_event(struct input_handle *handle,
72 unsigned int type, unsigned int code, int value)
74 struct evdev *evdev = handle->private;
75 struct evdev_client *client;
76 struct input_event event;
78 do_gettimeofday(&event.time);
85 client = rcu_dereference(evdev->grab);
87 evdev_pass_event(client, &event);
89 list_for_each_entry_rcu(client, &evdev->client_list, node)
90 evdev_pass_event(client, &event);
94 wake_up_interruptible(&evdev->wait);
97 static int evdev_fasync(int fd, struct file *file, int on)
99 struct evdev_client *client = file->private_data;
101 return fasync_helper(fd, file, on, &client->fasync);
104 static int evdev_flush(struct file *file, fl_owner_t id)
106 struct evdev_client *client = file->private_data;
107 struct evdev *evdev = client->evdev;
110 retval = mutex_lock_interruptible(&evdev->mutex);
117 retval = input_flush_device(&evdev->handle, file);
119 mutex_unlock(&evdev->mutex);
123 static void evdev_free(struct device *dev)
125 struct evdev *evdev = container_of(dev, struct evdev, dev);
127 input_put_device(evdev->handle.dev);
132 * Grabs an event device (along with underlying input device).
133 * This function is called with evdev->mutex taken.
135 static int evdev_grab(struct evdev *evdev, struct evdev_client *client)
142 error = input_grab_device(&evdev->handle);
146 rcu_assign_pointer(evdev->grab, client);
152 static int evdev_ungrab(struct evdev *evdev, struct evdev_client *client)
154 if (evdev->grab != client)
157 rcu_assign_pointer(evdev->grab, NULL);
159 input_release_device(&evdev->handle);
164 static void evdev_attach_client(struct evdev *evdev,
165 struct evdev_client *client)
167 spin_lock(&evdev->client_lock);
168 list_add_tail_rcu(&client->node, &evdev->client_list);
169 spin_unlock(&evdev->client_lock);
173 static void evdev_detach_client(struct evdev *evdev,
174 struct evdev_client *client)
176 spin_lock(&evdev->client_lock);
177 list_del_rcu(&client->node);
178 spin_unlock(&evdev->client_lock);
182 static int evdev_open_device(struct evdev *evdev)
186 retval = mutex_lock_interruptible(&evdev->mutex);
192 else if (!evdev->open++) {
193 retval = input_open_device(&evdev->handle);
198 mutex_unlock(&evdev->mutex);
202 static void evdev_close_device(struct evdev *evdev)
204 mutex_lock(&evdev->mutex);
206 if (evdev->exist && !--evdev->open)
207 input_close_device(&evdev->handle);
209 mutex_unlock(&evdev->mutex);
213 * Wake up users waiting for IO so they can disconnect from
216 static void evdev_hangup(struct evdev *evdev)
218 struct evdev_client *client;
220 spin_lock(&evdev->client_lock);
221 list_for_each_entry(client, &evdev->client_list, node)
222 kill_fasync(&client->fasync, SIGIO, POLL_HUP);
223 spin_unlock(&evdev->client_lock);
225 wake_up_interruptible(&evdev->wait);
228 static int evdev_release(struct inode *inode, struct file *file)
230 struct evdev_client *client = file->private_data;
231 struct evdev *evdev = client->evdev;
233 mutex_lock(&evdev->mutex);
234 if (evdev->grab == client)
235 evdev_ungrab(evdev, client);
236 mutex_unlock(&evdev->mutex);
238 evdev_detach_client(evdev, client);
241 evdev_close_device(evdev);
242 put_device(&evdev->dev);
247 static unsigned int evdev_compute_buffer_size(struct input_dev *dev)
249 unsigned int n_events =
250 max(dev->hint_events_per_packet * EVDEV_BUF_PACKETS,
251 EVDEV_MIN_BUFFER_SIZE);
253 return roundup_pow_of_two(n_events);
256 static int evdev_open(struct inode *inode, struct file *file)
259 struct evdev_client *client;
260 int i = iminor(inode) - EVDEV_MINOR_BASE;
261 unsigned int bufsize;
264 if (i >= EVDEV_MINORS)
267 error = mutex_lock_interruptible(&evdev_table_mutex);
270 evdev = evdev_table[i];
272 get_device(&evdev->dev);
273 mutex_unlock(&evdev_table_mutex);
278 bufsize = evdev_compute_buffer_size(evdev->handle.dev);
280 client = kzalloc(sizeof(struct evdev_client) +
281 bufsize * sizeof(struct input_event),
288 client->bufsize = bufsize;
289 spin_lock_init(&client->buffer_lock);
290 client->evdev = evdev;
291 evdev_attach_client(evdev, client);
293 error = evdev_open_device(evdev);
295 goto err_free_client;
297 file->private_data = client;
298 nonseekable_open(inode, file);
303 evdev_detach_client(evdev, client);
306 put_device(&evdev->dev);
310 static ssize_t evdev_write(struct file *file, const char __user *buffer,
311 size_t count, loff_t *ppos)
313 struct evdev_client *client = file->private_data;
314 struct evdev *evdev = client->evdev;
315 struct input_event event;
318 retval = mutex_lock_interruptible(&evdev->mutex);
327 while (retval < count) {
329 if (input_event_from_user(buffer + retval, &event)) {
334 input_inject_event(&evdev->handle,
335 event.type, event.code, event.value);
336 retval += input_event_size();
340 mutex_unlock(&evdev->mutex);
344 static int evdev_fetch_next_event(struct evdev_client *client,
345 struct input_event *event)
349 spin_lock_irq(&client->buffer_lock);
351 have_event = client->head != client->tail;
353 *event = client->buffer[client->tail++];
354 client->tail &= client->bufsize - 1;
357 spin_unlock_irq(&client->buffer_lock);
362 static ssize_t evdev_read(struct file *file, char __user *buffer,
363 size_t count, loff_t *ppos)
365 struct evdev_client *client = file->private_data;
366 struct evdev *evdev = client->evdev;
367 struct input_event event;
370 if (count < input_event_size())
373 if (client->head == client->tail && evdev->exist &&
374 (file->f_flags & O_NONBLOCK))
377 retval = wait_event_interruptible(evdev->wait,
378 client->head != client->tail || !evdev->exist);
385 while (retval + input_event_size() <= count &&
386 evdev_fetch_next_event(client, &event)) {
388 if (input_event_to_user(buffer + retval, &event))
391 retval += input_event_size();
397 /* No kernel lock - fine */
398 static unsigned int evdev_poll(struct file *file, poll_table *wait)
400 struct evdev_client *client = file->private_data;
401 struct evdev *evdev = client->evdev;
403 poll_wait(file, &evdev->wait, wait);
404 return ((client->head == client->tail) ? 0 : (POLLIN | POLLRDNORM)) |
405 (evdev->exist ? 0 : (POLLHUP | POLLERR));
410 #define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8)
411 #define BITS_TO_LONGS_COMPAT(x) ((((x) - 1) / BITS_PER_LONG_COMPAT) + 1)
414 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
415 unsigned int maxlen, void __user *p, int compat)
420 len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
424 for (i = 0; i < len / sizeof(compat_long_t); i++)
425 if (copy_to_user((compat_long_t __user *) p + i,
426 (compat_long_t *) bits +
427 i + 1 - ((i % 2) << 1),
428 sizeof(compat_long_t)))
431 len = BITS_TO_LONGS(maxbit) * sizeof(long);
435 if (copy_to_user(p, bits, len))
442 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
443 unsigned int maxlen, void __user *p, int compat)
446 BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t) :
447 BITS_TO_LONGS(maxbit) * sizeof(long);
452 return copy_to_user(p, bits, len) ? -EFAULT : len;
454 #endif /* __BIG_ENDIAN */
458 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
459 unsigned int maxlen, void __user *p, int compat)
461 int len = BITS_TO_LONGS(maxbit) * sizeof(long);
466 return copy_to_user(p, bits, len) ? -EFAULT : len;
469 #endif /* CONFIG_COMPAT */
471 static int str_to_user(const char *str, unsigned int maxlen, void __user *p)
478 len = strlen(str) + 1;
482 return copy_to_user(p, str, len) ? -EFAULT : len;
485 #define OLD_KEY_MAX 0x1ff
486 static int handle_eviocgbit(struct input_dev *dev, unsigned int cmd, void __user *p, int compat_mode)
488 static unsigned long keymax_warn_time;
492 switch (_IOC_NR(cmd) & EV_MAX) {
494 case 0: bits = dev->evbit; len = EV_MAX; break;
495 case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
496 case EV_REL: bits = dev->relbit; len = REL_MAX; break;
497 case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
498 case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break;
499 case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
500 case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
501 case EV_FF: bits = dev->ffbit; len = FF_MAX; break;
502 case EV_SW: bits = dev->swbit; len = SW_MAX; break;
503 default: return -EINVAL;
507 * Work around bugs in userspace programs that like to do
508 * EVIOCGBIT(EV_KEY, KEY_MAX) and not realize that 'len'
509 * should be in bytes, not in bits.
511 if ((_IOC_NR(cmd) & EV_MAX) == EV_KEY && _IOC_SIZE(cmd) == OLD_KEY_MAX) {
513 if (printk_timed_ratelimit(&keymax_warn_time, 10 * 1000))
515 "evdev.c(EVIOCGBIT): Suspicious buffer size %u, "
516 "limiting output to %zu bytes. See "
517 "http://userweb.kernel.org/~dtor/eviocgbit-bug.html\n",
519 BITS_TO_LONGS(OLD_KEY_MAX) * sizeof(long));
522 return bits_to_user(bits, len, _IOC_SIZE(cmd), p, compat_mode);
526 static long evdev_do_ioctl(struct file *file, unsigned int cmd,
527 void __user *p, int compat_mode)
529 struct evdev_client *client = file->private_data;
530 struct evdev *evdev = client->evdev;
531 struct input_dev *dev = evdev->handle.dev;
532 struct input_absinfo abs;
533 struct ff_effect effect;
534 int __user *ip = (int __user *)p;
535 unsigned int i, t, u, v;
541 return put_user(EV_VERSION, ip);
544 if (copy_to_user(p, &dev->id, sizeof(struct input_id)))
549 if (!test_bit(EV_REP, dev->evbit))
551 if (put_user(dev->rep[REP_DELAY], ip))
553 if (put_user(dev->rep[REP_PERIOD], ip + 1))
558 if (!test_bit(EV_REP, dev->evbit))
562 if (get_user(v, ip + 1))
565 input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u);
566 input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v);
574 error = input_get_keycode(dev, t, &v);
578 if (put_user(v, ip + 1))
584 if (get_user(t, ip) || get_user(v, ip + 1))
587 return input_set_keycode(dev, t, v);
590 return input_ff_erase(dev, (int)(unsigned long) p, file);
593 i = test_bit(EV_FF, dev->evbit) ?
594 dev->ff->max_effects : 0;
601 return evdev_grab(evdev, client);
603 return evdev_ungrab(evdev, client);
607 if (_IOC_TYPE(cmd) != 'E')
610 if (_IOC_DIR(cmd) == _IOC_READ) {
612 if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0)))
613 return handle_eviocgbit(dev, cmd, p, compat_mode);
615 if (_IOC_NR(cmd) == _IOC_NR(EVIOCGKEY(0)))
616 return bits_to_user(dev->key, KEY_MAX, _IOC_SIZE(cmd),
619 if (_IOC_NR(cmd) == _IOC_NR(EVIOCGLED(0)))
620 return bits_to_user(dev->led, LED_MAX, _IOC_SIZE(cmd),
623 if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSND(0)))
624 return bits_to_user(dev->snd, SND_MAX, _IOC_SIZE(cmd),
627 if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSW(0)))
628 return bits_to_user(dev->sw, SW_MAX, _IOC_SIZE(cmd),
631 if (_IOC_NR(cmd) == _IOC_NR(EVIOCGNAME(0)))
632 return str_to_user(dev->name, _IOC_SIZE(cmd), p);
634 if (_IOC_NR(cmd) == _IOC_NR(EVIOCGPHYS(0)))
635 return str_to_user(dev->phys, _IOC_SIZE(cmd), p);
637 if (_IOC_NR(cmd) == _IOC_NR(EVIOCGUNIQ(0)))
638 return str_to_user(dev->uniq, _IOC_SIZE(cmd), p);
640 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {
642 t = _IOC_NR(cmd) & ABS_MAX;
644 abs.value = dev->abs[t];
645 abs.minimum = dev->absmin[t];
646 abs.maximum = dev->absmax[t];
647 abs.fuzz = dev->absfuzz[t];
648 abs.flat = dev->absflat[t];
649 abs.resolution = dev->absres[t];
651 if (copy_to_user(p, &abs, min_t(size_t,
653 sizeof(struct input_absinfo))))
661 if (_IOC_DIR(cmd) == _IOC_WRITE) {
663 if (_IOC_NR(cmd) == _IOC_NR(EVIOCSFF)) {
665 if (input_ff_effect_from_user(p, _IOC_SIZE(cmd), &effect))
668 error = input_ff_upload(dev, &effect, file);
670 if (put_user(effect.id, &(((struct ff_effect __user *)p)->id)))
676 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) {
678 t = _IOC_NR(cmd) & ABS_MAX;
680 if (copy_from_user(&abs, p, min_t(size_t,
682 sizeof(struct input_absinfo))))
686 * Take event lock to ensure that we are not
687 * changing device parameters in the middle
690 spin_lock_irq(&dev->event_lock);
692 dev->abs[t] = abs.value;
693 dev->absmin[t] = abs.minimum;
694 dev->absmax[t] = abs.maximum;
695 dev->absfuzz[t] = abs.fuzz;
696 dev->absflat[t] = abs.flat;
697 dev->absres[t] = _IOC_SIZE(cmd) < sizeof(struct input_absinfo) ?
700 spin_unlock_irq(&dev->event_lock);
709 static long evdev_ioctl_handler(struct file *file, unsigned int cmd,
710 void __user *p, int compat_mode)
712 struct evdev_client *client = file->private_data;
713 struct evdev *evdev = client->evdev;
716 retval = mutex_lock_interruptible(&evdev->mutex);
725 retval = evdev_do_ioctl(file, cmd, p, compat_mode);
728 mutex_unlock(&evdev->mutex);
732 static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
734 return evdev_ioctl_handler(file, cmd, (void __user *)arg, 0);
738 static long evdev_ioctl_compat(struct file *file,
739 unsigned int cmd, unsigned long arg)
741 return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1);
745 static const struct file_operations evdev_fops = {
746 .owner = THIS_MODULE,
748 .write = evdev_write,
751 .release = evdev_release,
752 .unlocked_ioctl = evdev_ioctl,
754 .compat_ioctl = evdev_ioctl_compat,
756 .fasync = evdev_fasync,
760 static int evdev_install_chrdev(struct evdev *evdev)
763 * No need to do any locking here as calls to connect and
764 * disconnect are serialized by the input core
766 evdev_table[evdev->minor] = evdev;
770 static void evdev_remove_chrdev(struct evdev *evdev)
773 * Lock evdev table to prevent race with evdev_open()
775 mutex_lock(&evdev_table_mutex);
776 evdev_table[evdev->minor] = NULL;
777 mutex_unlock(&evdev_table_mutex);
781 * Mark device non-existent. This disables writes, ioctls and
782 * prevents new users from opening the device. Already posted
783 * blocking reads will stay, however new ones will fail.
785 static void evdev_mark_dead(struct evdev *evdev)
787 mutex_lock(&evdev->mutex);
789 mutex_unlock(&evdev->mutex);
792 static void evdev_cleanup(struct evdev *evdev)
794 struct input_handle *handle = &evdev->handle;
796 evdev_mark_dead(evdev);
798 evdev_remove_chrdev(evdev);
800 /* evdev is marked dead so no one else accesses evdev->open */
802 input_flush_device(handle, NULL);
803 input_close_device(handle);
808 * Create new evdev device. Note that input core serializes calls
809 * to connect and disconnect so we don't need to lock evdev_table here.
811 static int evdev_connect(struct input_handler *handler, struct input_dev *dev,
812 const struct input_device_id *id)
818 for (minor = 0; minor < EVDEV_MINORS; minor++)
819 if (!evdev_table[minor])
822 if (minor == EVDEV_MINORS) {
823 printk(KERN_ERR "evdev: no more free evdev devices\n");
827 evdev = kzalloc(sizeof(struct evdev), GFP_KERNEL);
831 INIT_LIST_HEAD(&evdev->client_list);
832 spin_lock_init(&evdev->client_lock);
833 mutex_init(&evdev->mutex);
834 init_waitqueue_head(&evdev->wait);
836 dev_set_name(&evdev->dev, "event%d", minor);
838 evdev->minor = minor;
840 evdev->handle.dev = input_get_device(dev);
841 evdev->handle.name = dev_name(&evdev->dev);
842 evdev->handle.handler = handler;
843 evdev->handle.private = evdev;
845 evdev->dev.devt = MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + minor);
846 evdev->dev.class = &input_class;
847 evdev->dev.parent = &dev->dev;
848 evdev->dev.release = evdev_free;
849 device_initialize(&evdev->dev);
851 error = input_register_handle(&evdev->handle);
855 error = evdev_install_chrdev(evdev);
857 goto err_unregister_handle;
859 error = device_add(&evdev->dev);
861 goto err_cleanup_evdev;
866 evdev_cleanup(evdev);
867 err_unregister_handle:
868 input_unregister_handle(&evdev->handle);
870 put_device(&evdev->dev);
874 static void evdev_disconnect(struct input_handle *handle)
876 struct evdev *evdev = handle->private;
878 device_del(&evdev->dev);
879 evdev_cleanup(evdev);
880 input_unregister_handle(handle);
881 put_device(&evdev->dev);
884 static const struct input_device_id evdev_ids[] = {
885 { .driver_info = 1 }, /* Matches all devices */
886 { }, /* Terminating zero entry */
889 MODULE_DEVICE_TABLE(input, evdev_ids);
891 static struct input_handler evdev_handler = {
892 .event = evdev_event,
893 .connect = evdev_connect,
894 .disconnect = evdev_disconnect,
896 .minor = EVDEV_MINOR_BASE,
898 .id_table = evdev_ids,
901 static int __init evdev_init(void)
903 return input_register_handler(&evdev_handler);
906 static void __exit evdev_exit(void)
908 input_unregister_handler(&evdev_handler);
911 module_init(evdev_init);
912 module_exit(evdev_exit);
914 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
915 MODULE_DESCRIPTION("Input driver event char devices");
916 MODULE_LICENSE("GPL");