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 pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13 #define EVDEV_MINOR_BASE 64
14 #define EVDEV_MINORS 32
15 #define EVDEV_MIN_BUFFER_SIZE 64U
16 #define EVDEV_BUF_PACKETS 8
18 #include <linux/poll.h>
19 #include <linux/sched.h>
20 #include <linux/slab.h>
21 #include <linux/vmalloc.h>
23 #include <linux/module.h>
24 #include <linux/init.h>
25 #include <linux/input/mt.h>
26 #include <linux/major.h>
27 #include <linux/device.h>
28 #include <linux/cdev.h>
29 #include "input-compat.h"
31 enum evdev_clock_type {
40 struct input_handle handle;
41 wait_queue_head_t wait;
42 struct evdev_client __rcu *grab;
43 struct list_head client_list;
44 spinlock_t client_lock; /* protects client_list */
54 unsigned int packet_head; /* [future] position of the first element of next packet */
55 spinlock_t buffer_lock; /* protects access to buffer, head and tail */
56 struct fasync_struct *fasync;
58 struct list_head node;
62 struct input_event buffer[];
65 /* flush queued events of type @type, caller must hold client->buffer_lock */
66 static void __evdev_flush_queue(struct evdev_client *client, unsigned int type)
68 unsigned int i, head, num;
69 unsigned int mask = client->bufsize - 1;
71 struct input_event *ev;
73 BUG_ON(type == EV_SYN);
76 client->packet_head = client->tail;
78 /* init to 1 so a leading SYN_REPORT will not be dropped */
81 for (i = client->tail; i != client->head; i = (i + 1) & mask) {
82 ev = &client->buffer[i];
83 is_report = ev->type == EV_SYN && ev->code == SYN_REPORT;
85 if (ev->type == type) {
86 /* drop matched entry */
88 } else if (is_report && !num) {
89 /* drop empty SYN_REPORT groups */
91 } else if (head != i) {
92 /* move entry to fill the gap */
93 client->buffer[head].time = ev->time;
94 client->buffer[head].type = ev->type;
95 client->buffer[head].code = ev->code;
96 client->buffer[head].value = ev->value;
100 head = (head + 1) & mask;
104 client->packet_head = head;
111 /* queue SYN_DROPPED event and flush queue if flush parameter is true */
112 static void evdev_queue_syn_dropped(struct evdev_client *client, bool flush)
115 struct input_event ev;
118 time = client->clk_type == EV_CLK_REAL ?
120 client->clk_type == EV_CLK_MONO ?
122 ktime_get_boottime();
124 ev.time = ktime_to_timeval(time);
126 ev.code = SYN_DROPPED;
129 spin_lock_irqsave(&client->buffer_lock, flags);
132 client->packet_head = client->head = client->tail;
134 client->buffer[client->head++] = ev;
135 client->head &= client->bufsize - 1;
137 if (unlikely(client->head == client->tail)) {
138 /* drop queue but keep our SYN_DROPPED event */
139 client->tail = (client->head - 1) & (client->bufsize - 1);
140 client->packet_head = client->tail;
143 spin_unlock_irqrestore(&client->buffer_lock, flags);
146 static int evdev_set_clk_type(struct evdev_client *client, unsigned int clkid)
148 if (client->clk_type == clkid)
154 client->clk_type = EV_CLK_REAL;
156 case CLOCK_MONOTONIC:
157 client->clk_type = EV_CLK_MONO;
160 client->clk_type = EV_CLK_BOOT;
166 /* Flush pending events and queue SYN_DROPPED event.*/
167 evdev_queue_syn_dropped(client, true);
172 static void __pass_event(struct evdev_client *client,
173 const struct input_event *event)
175 client->buffer[client->head++] = *event;
176 client->head &= client->bufsize - 1;
178 if (unlikely(client->head == client->tail)) {
180 * This effectively "drops" all unconsumed events, leaving
181 * EV_SYN/SYN_DROPPED plus the newest event in the queue.
183 client->tail = (client->head - 2) & (client->bufsize - 1);
185 client->buffer[client->tail].time = event->time;
186 client->buffer[client->tail].type = EV_SYN;
187 client->buffer[client->tail].code = SYN_DROPPED;
188 client->buffer[client->tail].value = 0;
190 client->packet_head = client->tail;
193 if (event->type == EV_SYN && event->code == SYN_REPORT) {
194 client->packet_head = client->head;
195 kill_fasync(&client->fasync, SIGIO, POLL_IN);
199 static void evdev_pass_values(struct evdev_client *client,
200 const struct input_value *vals, unsigned int count,
203 struct evdev *evdev = client->evdev;
204 const struct input_value *v;
205 struct input_event event;
211 event.time = ktime_to_timeval(ev_time[client->clk_type]);
213 /* Interrupts are disabled, just acquire the lock. */
214 spin_lock(&client->buffer_lock);
216 for (v = vals; v != vals + count; v++) {
217 event.type = v->type;
218 event.code = v->code;
219 event.value = v->value;
220 __pass_event(client, &event);
221 if (v->type == EV_SYN && v->code == SYN_REPORT)
225 spin_unlock(&client->buffer_lock);
228 wake_up_interruptible(&evdev->wait);
232 * Pass incoming events to all connected clients.
234 static void evdev_events(struct input_handle *handle,
235 const struct input_value *vals, unsigned int count)
237 struct evdev *evdev = handle->private;
238 struct evdev_client *client;
239 ktime_t ev_time[EV_CLK_MAX];
241 ev_time[EV_CLK_MONO] = ktime_get();
242 ev_time[EV_CLK_REAL] = ktime_mono_to_real(ev_time[EV_CLK_MONO]);
243 ev_time[EV_CLK_BOOT] = ktime_mono_to_any(ev_time[EV_CLK_MONO],
248 client = rcu_dereference(evdev->grab);
251 evdev_pass_values(client, vals, count, ev_time);
253 list_for_each_entry_rcu(client, &evdev->client_list, node)
254 evdev_pass_values(client, vals, count, ev_time);
260 * Pass incoming event to all connected clients.
262 static void evdev_event(struct input_handle *handle,
263 unsigned int type, unsigned int code, int value)
265 struct input_value vals[] = { { type, code, value } };
267 evdev_events(handle, vals, 1);
270 static int evdev_fasync(int fd, struct file *file, int on)
272 struct evdev_client *client = file->private_data;
274 return fasync_helper(fd, file, on, &client->fasync);
277 static int evdev_flush(struct file *file, fl_owner_t id)
279 struct evdev_client *client = file->private_data;
280 struct evdev *evdev = client->evdev;
283 retval = mutex_lock_interruptible(&evdev->mutex);
287 if (!evdev->exist || client->revoked)
290 retval = input_flush_device(&evdev->handle, file);
292 mutex_unlock(&evdev->mutex);
296 static void evdev_free(struct device *dev)
298 struct evdev *evdev = container_of(dev, struct evdev, dev);
300 input_put_device(evdev->handle.dev);
305 * Grabs an event device (along with underlying input device).
306 * This function is called with evdev->mutex taken.
308 static int evdev_grab(struct evdev *evdev, struct evdev_client *client)
315 error = input_grab_device(&evdev->handle);
319 rcu_assign_pointer(evdev->grab, client);
324 static int evdev_ungrab(struct evdev *evdev, struct evdev_client *client)
326 struct evdev_client *grab = rcu_dereference_protected(evdev->grab,
327 lockdep_is_held(&evdev->mutex));
332 rcu_assign_pointer(evdev->grab, NULL);
334 input_release_device(&evdev->handle);
339 static void evdev_attach_client(struct evdev *evdev,
340 struct evdev_client *client)
342 spin_lock(&evdev->client_lock);
343 list_add_tail_rcu(&client->node, &evdev->client_list);
344 spin_unlock(&evdev->client_lock);
347 static void evdev_detach_client(struct evdev *evdev,
348 struct evdev_client *client)
350 spin_lock(&evdev->client_lock);
351 list_del_rcu(&client->node);
352 spin_unlock(&evdev->client_lock);
356 static int evdev_open_device(struct evdev *evdev)
360 retval = mutex_lock_interruptible(&evdev->mutex);
366 else if (!evdev->open++) {
367 retval = input_open_device(&evdev->handle);
372 mutex_unlock(&evdev->mutex);
376 static void evdev_close_device(struct evdev *evdev)
378 mutex_lock(&evdev->mutex);
380 if (evdev->exist && !--evdev->open)
381 input_close_device(&evdev->handle);
383 mutex_unlock(&evdev->mutex);
387 * Wake up users waiting for IO so they can disconnect from
390 static void evdev_hangup(struct evdev *evdev)
392 struct evdev_client *client;
394 spin_lock(&evdev->client_lock);
395 list_for_each_entry(client, &evdev->client_list, node)
396 kill_fasync(&client->fasync, SIGIO, POLL_HUP);
397 spin_unlock(&evdev->client_lock);
399 wake_up_interruptible(&evdev->wait);
402 static int evdev_release(struct inode *inode, struct file *file)
404 struct evdev_client *client = file->private_data;
405 struct evdev *evdev = client->evdev;
407 mutex_lock(&evdev->mutex);
408 evdev_ungrab(evdev, client);
409 mutex_unlock(&evdev->mutex);
411 evdev_detach_client(evdev, client);
413 if (is_vmalloc_addr(client))
418 evdev_close_device(evdev);
423 static unsigned int evdev_compute_buffer_size(struct input_dev *dev)
425 unsigned int n_events =
426 max(dev->hint_events_per_packet * EVDEV_BUF_PACKETS,
427 EVDEV_MIN_BUFFER_SIZE);
429 return roundup_pow_of_two(n_events);
432 static int evdev_open(struct inode *inode, struct file *file)
434 struct evdev *evdev = container_of(inode->i_cdev, struct evdev, cdev);
435 unsigned int bufsize = evdev_compute_buffer_size(evdev->handle.dev);
436 unsigned int size = sizeof(struct evdev_client) +
437 bufsize * sizeof(struct input_event);
438 struct evdev_client *client;
441 client = kzalloc(size, GFP_KERNEL | __GFP_NOWARN);
443 client = vzalloc(size);
447 client->bufsize = bufsize;
448 spin_lock_init(&client->buffer_lock);
449 client->evdev = evdev;
450 evdev_attach_client(evdev, client);
452 error = evdev_open_device(evdev);
454 goto err_free_client;
456 file->private_data = client;
457 nonseekable_open(inode, file);
462 evdev_detach_client(evdev, client);
467 static ssize_t evdev_write(struct file *file, const char __user *buffer,
468 size_t count, loff_t *ppos)
470 struct evdev_client *client = file->private_data;
471 struct evdev *evdev = client->evdev;
472 struct input_event event;
475 if (count != 0 && count < input_event_size())
478 retval = mutex_lock_interruptible(&evdev->mutex);
482 if (!evdev->exist || client->revoked) {
487 while (retval + input_event_size() <= count) {
489 if (input_event_from_user(buffer + retval, &event)) {
493 retval += input_event_size();
495 input_inject_event(&evdev->handle,
496 event.type, event.code, event.value);
500 mutex_unlock(&evdev->mutex);
504 static int evdev_fetch_next_event(struct evdev_client *client,
505 struct input_event *event)
509 spin_lock_irq(&client->buffer_lock);
511 have_event = client->packet_head != client->tail;
513 *event = client->buffer[client->tail++];
514 client->tail &= client->bufsize - 1;
517 spin_unlock_irq(&client->buffer_lock);
522 static ssize_t evdev_read(struct file *file, char __user *buffer,
523 size_t count, loff_t *ppos)
525 struct evdev_client *client = file->private_data;
526 struct evdev *evdev = client->evdev;
527 struct input_event event;
531 if (count != 0 && count < input_event_size())
535 if (!evdev->exist || client->revoked)
538 if (client->packet_head == client->tail &&
539 (file->f_flags & O_NONBLOCK))
543 * count == 0 is special - no IO is done but we check
544 * for error conditions (see above).
549 while (read + input_event_size() <= count &&
550 evdev_fetch_next_event(client, &event)) {
552 if (input_event_to_user(buffer + read, &event))
555 read += input_event_size();
561 if (!(file->f_flags & O_NONBLOCK)) {
562 error = wait_event_interruptible(evdev->wait,
563 client->packet_head != client->tail ||
564 !evdev->exist || client->revoked);
573 /* No kernel lock - fine */
574 static unsigned int evdev_poll(struct file *file, poll_table *wait)
576 struct evdev_client *client = file->private_data;
577 struct evdev *evdev = client->evdev;
580 poll_wait(file, &evdev->wait, wait);
582 if (evdev->exist && !client->revoked)
583 mask = POLLOUT | POLLWRNORM;
585 mask = POLLHUP | POLLERR;
587 if (client->packet_head != client->tail)
588 mask |= POLLIN | POLLRDNORM;
595 #define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8)
596 #define BITS_TO_LONGS_COMPAT(x) ((((x) - 1) / BITS_PER_LONG_COMPAT) + 1)
599 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
600 unsigned int maxlen, void __user *p, int compat)
605 len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
609 for (i = 0; i < len / sizeof(compat_long_t); i++)
610 if (copy_to_user((compat_long_t __user *) p + i,
611 (compat_long_t *) bits +
612 i + 1 - ((i % 2) << 1),
613 sizeof(compat_long_t)))
616 len = BITS_TO_LONGS(maxbit) * sizeof(long);
620 if (copy_to_user(p, bits, len))
627 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
628 unsigned int maxlen, void __user *p, int compat)
631 BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t) :
632 BITS_TO_LONGS(maxbit) * sizeof(long);
637 return copy_to_user(p, bits, len) ? -EFAULT : len;
639 #endif /* __BIG_ENDIAN */
643 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
644 unsigned int maxlen, void __user *p, int compat)
646 int len = BITS_TO_LONGS(maxbit) * sizeof(long);
651 return copy_to_user(p, bits, len) ? -EFAULT : len;
654 #endif /* CONFIG_COMPAT */
656 static int str_to_user(const char *str, unsigned int maxlen, void __user *p)
663 len = strlen(str) + 1;
667 return copy_to_user(p, str, len) ? -EFAULT : len;
670 static int handle_eviocgbit(struct input_dev *dev,
671 unsigned int type, unsigned int size,
672 void __user *p, int compat_mode)
679 case 0: bits = dev->evbit; len = EV_MAX; break;
680 case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
681 case EV_REL: bits = dev->relbit; len = REL_MAX; break;
682 case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
683 case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break;
684 case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
685 case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
686 case EV_FF: bits = dev->ffbit; len = FF_MAX; break;
687 case EV_SW: bits = dev->swbit; len = SW_MAX; break;
688 default: return -EINVAL;
691 return bits_to_user(bits, len, size, p, compat_mode);
694 static int evdev_handle_get_keycode(struct input_dev *dev, void __user *p)
696 struct input_keymap_entry ke = {
697 .len = sizeof(unsigned int),
700 int __user *ip = (int __user *)p;
704 if (copy_from_user(ke.scancode, p, sizeof(unsigned int)))
707 error = input_get_keycode(dev, &ke);
711 if (put_user(ke.keycode, ip + 1))
717 static int evdev_handle_get_keycode_v2(struct input_dev *dev, void __user *p)
719 struct input_keymap_entry ke;
722 if (copy_from_user(&ke, p, sizeof(ke)))
725 error = input_get_keycode(dev, &ke);
729 if (copy_to_user(p, &ke, sizeof(ke)))
735 static int evdev_handle_set_keycode(struct input_dev *dev, void __user *p)
737 struct input_keymap_entry ke = {
738 .len = sizeof(unsigned int),
741 int __user *ip = (int __user *)p;
743 if (copy_from_user(ke.scancode, p, sizeof(unsigned int)))
746 if (get_user(ke.keycode, ip + 1))
749 return input_set_keycode(dev, &ke);
752 static int evdev_handle_set_keycode_v2(struct input_dev *dev, void __user *p)
754 struct input_keymap_entry ke;
756 if (copy_from_user(&ke, p, sizeof(ke)))
759 if (ke.len > sizeof(ke.scancode))
762 return input_set_keycode(dev, &ke);
766 * If we transfer state to the user, we should flush all pending events
767 * of the same type from the client's queue. Otherwise, they might end up
768 * with duplicate events, which can screw up client's state tracking.
769 * If bits_to_user fails after flushing the queue, we queue a SYN_DROPPED
770 * event so user-space will notice missing events.
773 * We need to take event_lock before buffer_lock to avoid dead-locks. But we
774 * need the even_lock only to guarantee consistent state. We can safely release
775 * it while flushing the queue. This allows input-core to handle filters while
776 * we flush the queue.
778 static int evdev_handle_get_val(struct evdev_client *client,
779 struct input_dev *dev, unsigned int type,
780 unsigned long *bits, unsigned int maxbit,
781 unsigned int maxlen, void __user *p,
788 len = BITS_TO_LONGS(maxbit) * sizeof(unsigned long);
789 mem = kmalloc(len, GFP_KERNEL);
793 spin_lock_irq(&dev->event_lock);
794 spin_lock(&client->buffer_lock);
796 memcpy(mem, bits, len);
798 spin_unlock(&dev->event_lock);
800 __evdev_flush_queue(client, type);
802 spin_unlock_irq(&client->buffer_lock);
804 ret = bits_to_user(mem, maxbit, maxlen, p, compat);
806 evdev_queue_syn_dropped(client, false);
813 static int evdev_handle_mt_request(struct input_dev *dev,
817 const struct input_mt *mt = dev->mt;
822 if (get_user(code, &ip[0]))
824 if (!mt || !input_is_mt_value(code))
827 max_slots = (size - sizeof(__u32)) / sizeof(__s32);
828 for (i = 0; i < mt->num_slots && i < max_slots; i++) {
829 int value = input_mt_get_value(&mt->slots[i], code);
830 if (put_user(value, &ip[1 + i]))
837 static int evdev_revoke(struct evdev *evdev, struct evdev_client *client,
840 client->revoked = true;
841 evdev_ungrab(evdev, client);
842 input_flush_device(&evdev->handle, file);
843 wake_up_interruptible(&evdev->wait);
848 static long evdev_do_ioctl(struct file *file, unsigned int cmd,
849 void __user *p, int compat_mode)
851 struct evdev_client *client = file->private_data;
852 struct evdev *evdev = client->evdev;
853 struct input_dev *dev = evdev->handle.dev;
854 struct input_absinfo abs;
855 struct ff_effect effect;
856 int __user *ip = (int __user *)p;
857 unsigned int i, t, u, v;
861 /* First we check for fixed-length commands */
865 return put_user(EV_VERSION, ip);
868 if (copy_to_user(p, &dev->id, sizeof(struct input_id)))
873 if (!test_bit(EV_REP, dev->evbit))
875 if (put_user(dev->rep[REP_DELAY], ip))
877 if (put_user(dev->rep[REP_PERIOD], ip + 1))
882 if (!test_bit(EV_REP, dev->evbit))
886 if (get_user(v, ip + 1))
889 input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u);
890 input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v);
895 return input_ff_erase(dev, (int)(unsigned long) p, file);
898 i = test_bit(EV_FF, dev->evbit) ?
899 dev->ff->max_effects : 0;
906 return evdev_grab(evdev, client);
908 return evdev_ungrab(evdev, client);
914 return evdev_revoke(evdev, client, file);
917 if (copy_from_user(&i, p, sizeof(unsigned int)))
920 return evdev_set_clk_type(client, i);
923 return evdev_handle_get_keycode(dev, p);
926 return evdev_handle_set_keycode(dev, p);
928 case EVIOCGKEYCODE_V2:
929 return evdev_handle_get_keycode_v2(dev, p);
931 case EVIOCSKEYCODE_V2:
932 return evdev_handle_set_keycode_v2(dev, p);
935 size = _IOC_SIZE(cmd);
937 /* Now check variable-length commands */
938 #define EVIOC_MASK_SIZE(nr) ((nr) & ~(_IOC_SIZEMASK << _IOC_SIZESHIFT))
939 switch (EVIOC_MASK_SIZE(cmd)) {
942 return bits_to_user(dev->propbit, INPUT_PROP_MAX,
943 size, p, compat_mode);
945 case EVIOCGMTSLOTS(0):
946 return evdev_handle_mt_request(dev, size, ip);
949 return evdev_handle_get_val(client, dev, EV_KEY, dev->key,
950 KEY_MAX, size, p, compat_mode);
953 return evdev_handle_get_val(client, dev, EV_LED, dev->led,
954 LED_MAX, size, p, compat_mode);
957 return evdev_handle_get_val(client, dev, EV_SND, dev->snd,
958 SND_MAX, size, p, compat_mode);
961 return evdev_handle_get_val(client, dev, EV_SW, dev->sw,
962 SW_MAX, size, p, compat_mode);
965 return str_to_user(dev->name, size, p);
968 return str_to_user(dev->phys, size, p);
971 return str_to_user(dev->uniq, size, p);
973 case EVIOC_MASK_SIZE(EVIOCSFF):
974 if (input_ff_effect_from_user(p, size, &effect))
977 error = input_ff_upload(dev, &effect, file);
981 if (put_user(effect.id, &(((struct ff_effect __user *)p)->id)))
987 /* Multi-number variable-length handlers */
988 if (_IOC_TYPE(cmd) != 'E')
991 if (_IOC_DIR(cmd) == _IOC_READ) {
993 if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0)))
994 return handle_eviocgbit(dev,
995 _IOC_NR(cmd) & EV_MAX, size,
998 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {
1003 t = _IOC_NR(cmd) & ABS_MAX;
1004 abs = dev->absinfo[t];
1006 if (copy_to_user(p, &abs, min_t(size_t,
1007 size, sizeof(struct input_absinfo))))
1014 if (_IOC_DIR(cmd) == _IOC_WRITE) {
1016 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) {
1021 t = _IOC_NR(cmd) & ABS_MAX;
1023 if (copy_from_user(&abs, p, min_t(size_t,
1024 size, sizeof(struct input_absinfo))))
1027 if (size < sizeof(struct input_absinfo))
1030 /* We can't change number of reserved MT slots */
1031 if (t == ABS_MT_SLOT)
1035 * Take event lock to ensure that we are not
1036 * changing device parameters in the middle
1039 spin_lock_irq(&dev->event_lock);
1040 dev->absinfo[t] = abs;
1041 spin_unlock_irq(&dev->event_lock);
1050 static long evdev_ioctl_handler(struct file *file, unsigned int cmd,
1051 void __user *p, int compat_mode)
1053 struct evdev_client *client = file->private_data;
1054 struct evdev *evdev = client->evdev;
1057 retval = mutex_lock_interruptible(&evdev->mutex);
1061 if (!evdev->exist || client->revoked) {
1066 retval = evdev_do_ioctl(file, cmd, p, compat_mode);
1069 mutex_unlock(&evdev->mutex);
1073 static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1075 return evdev_ioctl_handler(file, cmd, (void __user *)arg, 0);
1078 #ifdef CONFIG_COMPAT
1079 static long evdev_ioctl_compat(struct file *file,
1080 unsigned int cmd, unsigned long arg)
1082 return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1);
1086 static const struct file_operations evdev_fops = {
1087 .owner = THIS_MODULE,
1089 .write = evdev_write,
1092 .release = evdev_release,
1093 .unlocked_ioctl = evdev_ioctl,
1094 #ifdef CONFIG_COMPAT
1095 .compat_ioctl = evdev_ioctl_compat,
1097 .fasync = evdev_fasync,
1098 .flush = evdev_flush,
1099 .llseek = no_llseek,
1103 * Mark device non-existent. This disables writes, ioctls and
1104 * prevents new users from opening the device. Already posted
1105 * blocking reads will stay, however new ones will fail.
1107 static void evdev_mark_dead(struct evdev *evdev)
1109 mutex_lock(&evdev->mutex);
1110 evdev->exist = false;
1111 mutex_unlock(&evdev->mutex);
1114 static void evdev_cleanup(struct evdev *evdev)
1116 struct input_handle *handle = &evdev->handle;
1118 evdev_mark_dead(evdev);
1119 evdev_hangup(evdev);
1121 cdev_del(&evdev->cdev);
1123 /* evdev is marked dead so no one else accesses evdev->open */
1125 input_flush_device(handle, NULL);
1126 input_close_device(handle);
1131 * Create new evdev device. Note that input core serializes calls
1132 * to connect and disconnect.
1134 static int evdev_connect(struct input_handler *handler, struct input_dev *dev,
1135 const struct input_device_id *id)
1137 struct evdev *evdev;
1142 minor = input_get_new_minor(EVDEV_MINOR_BASE, EVDEV_MINORS, true);
1145 pr_err("failed to reserve new minor: %d\n", error);
1149 evdev = kzalloc(sizeof(struct evdev), GFP_KERNEL);
1152 goto err_free_minor;
1155 INIT_LIST_HEAD(&evdev->client_list);
1156 spin_lock_init(&evdev->client_lock);
1157 mutex_init(&evdev->mutex);
1158 init_waitqueue_head(&evdev->wait);
1159 evdev->exist = true;
1162 /* Normalize device number if it falls into legacy range */
1163 if (dev_no < EVDEV_MINOR_BASE + EVDEV_MINORS)
1164 dev_no -= EVDEV_MINOR_BASE;
1165 dev_set_name(&evdev->dev, "event%d", dev_no);
1167 evdev->handle.dev = input_get_device(dev);
1168 evdev->handle.name = dev_name(&evdev->dev);
1169 evdev->handle.handler = handler;
1170 evdev->handle.private = evdev;
1172 evdev->dev.devt = MKDEV(INPUT_MAJOR, minor);
1173 evdev->dev.class = &input_class;
1174 evdev->dev.parent = &dev->dev;
1175 evdev->dev.release = evdev_free;
1176 device_initialize(&evdev->dev);
1178 error = input_register_handle(&evdev->handle);
1180 goto err_free_evdev;
1182 cdev_init(&evdev->cdev, &evdev_fops);
1183 evdev->cdev.kobj.parent = &evdev->dev.kobj;
1184 error = cdev_add(&evdev->cdev, evdev->dev.devt, 1);
1186 goto err_unregister_handle;
1188 error = device_add(&evdev->dev);
1190 goto err_cleanup_evdev;
1195 evdev_cleanup(evdev);
1196 err_unregister_handle:
1197 input_unregister_handle(&evdev->handle);
1199 put_device(&evdev->dev);
1201 input_free_minor(minor);
1205 static void evdev_disconnect(struct input_handle *handle)
1207 struct evdev *evdev = handle->private;
1209 device_del(&evdev->dev);
1210 evdev_cleanup(evdev);
1211 input_free_minor(MINOR(evdev->dev.devt));
1212 input_unregister_handle(handle);
1213 put_device(&evdev->dev);
1216 static const struct input_device_id evdev_ids[] = {
1217 { .driver_info = 1 }, /* Matches all devices */
1218 { }, /* Terminating zero entry */
1221 MODULE_DEVICE_TABLE(input, evdev_ids);
1223 static struct input_handler evdev_handler = {
1224 .event = evdev_event,
1225 .events = evdev_events,
1226 .connect = evdev_connect,
1227 .disconnect = evdev_disconnect,
1228 .legacy_minors = true,
1229 .minor = EVDEV_MINOR_BASE,
1231 .id_table = evdev_ids,
1234 static int __init evdev_init(void)
1236 return input_register_handler(&evdev_handler);
1239 static void __exit evdev_exit(void)
1241 input_unregister_handler(&evdev_handler);
1244 module_init(evdev_init);
1245 module_exit(evdev_exit);
1247 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
1248 MODULE_DESCRIPTION("Input driver event char devices");
1249 MODULE_LICENSE("GPL");