x86/amd-iommu: Add per IOMMU reference counting
[linux/fpc-iii.git] / drivers / input / input.c
blobcc763c96fadadf0565048a2a897d0f6202d81f09
1 /*
2 * The input core
4 * Copyright (c) 1999-2002 Vojtech Pavlik
5 */
7 /*
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License version 2 as published by
10 * the Free Software Foundation.
13 #include <linux/init.h>
14 #include <linux/types.h>
15 #include <linux/input.h>
16 #include <linux/module.h>
17 #include <linux/random.h>
18 #include <linux/major.h>
19 #include <linux/proc_fs.h>
20 #include <linux/sched.h>
21 #include <linux/seq_file.h>
22 #include <linux/poll.h>
23 #include <linux/device.h>
24 #include <linux/mutex.h>
25 #include <linux/rcupdate.h>
26 #include <linux/smp_lock.h>
28 MODULE_AUTHOR("Vojtech Pavlik <vojtech@suse.cz>");
29 MODULE_DESCRIPTION("Input core");
30 MODULE_LICENSE("GPL");
32 #define INPUT_DEVICES 256
35 * EV_ABS events which should not be cached are listed here.
37 static unsigned int input_abs_bypass_init_data[] __initdata = {
38 ABS_MT_TOUCH_MAJOR,
39 ABS_MT_TOUCH_MINOR,
40 ABS_MT_WIDTH_MAJOR,
41 ABS_MT_WIDTH_MINOR,
42 ABS_MT_ORIENTATION,
43 ABS_MT_POSITION_X,
44 ABS_MT_POSITION_Y,
45 ABS_MT_TOOL_TYPE,
46 ABS_MT_BLOB_ID,
47 ABS_MT_TRACKING_ID,
50 static unsigned long input_abs_bypass[BITS_TO_LONGS(ABS_CNT)];
52 static LIST_HEAD(input_dev_list);
53 static LIST_HEAD(input_handler_list);
56 * input_mutex protects access to both input_dev_list and input_handler_list.
57 * This also causes input_[un]register_device and input_[un]register_handler
58 * be mutually exclusive which simplifies locking in drivers implementing
59 * input handlers.
61 static DEFINE_MUTEX(input_mutex);
63 static struct input_handler *input_table[8];
65 static inline int is_event_supported(unsigned int code,
66 unsigned long *bm, unsigned int max)
68 return code <= max && test_bit(code, bm);
71 static int input_defuzz_abs_event(int value, int old_val, int fuzz)
73 if (fuzz) {
74 if (value > old_val - fuzz / 2 && value < old_val + fuzz / 2)
75 return old_val;
77 if (value > old_val - fuzz && value < old_val + fuzz)
78 return (old_val * 3 + value) / 4;
80 if (value > old_val - fuzz * 2 && value < old_val + fuzz * 2)
81 return (old_val + value) / 2;
84 return value;
88 * Pass event through all open handles. This function is called with
89 * dev->event_lock held and interrupts disabled.
91 static void input_pass_event(struct input_dev *dev,
92 unsigned int type, unsigned int code, int value)
94 struct input_handle *handle;
96 rcu_read_lock();
98 handle = rcu_dereference(dev->grab);
99 if (handle)
100 handle->handler->event(handle, type, code, value);
101 else
102 list_for_each_entry_rcu(handle, &dev->h_list, d_node)
103 if (handle->open)
104 handle->handler->event(handle,
105 type, code, value);
106 rcu_read_unlock();
110 * Generate software autorepeat event. Note that we take
111 * dev->event_lock here to avoid racing with input_event
112 * which may cause keys get "stuck".
114 static void input_repeat_key(unsigned long data)
116 struct input_dev *dev = (void *) data;
117 unsigned long flags;
119 spin_lock_irqsave(&dev->event_lock, flags);
121 if (test_bit(dev->repeat_key, dev->key) &&
122 is_event_supported(dev->repeat_key, dev->keybit, KEY_MAX)) {
124 input_pass_event(dev, EV_KEY, dev->repeat_key, 2);
126 if (dev->sync) {
128 * Only send SYN_REPORT if we are not in a middle
129 * of driver parsing a new hardware packet.
130 * Otherwise assume that the driver will send
131 * SYN_REPORT once it's done.
133 input_pass_event(dev, EV_SYN, SYN_REPORT, 1);
136 if (dev->rep[REP_PERIOD])
137 mod_timer(&dev->timer, jiffies +
138 msecs_to_jiffies(dev->rep[REP_PERIOD]));
141 spin_unlock_irqrestore(&dev->event_lock, flags);
144 static void input_start_autorepeat(struct input_dev *dev, int code)
146 if (test_bit(EV_REP, dev->evbit) &&
147 dev->rep[REP_PERIOD] && dev->rep[REP_DELAY] &&
148 dev->timer.data) {
149 dev->repeat_key = code;
150 mod_timer(&dev->timer,
151 jiffies + msecs_to_jiffies(dev->rep[REP_DELAY]));
155 static void input_stop_autorepeat(struct input_dev *dev)
157 del_timer(&dev->timer);
160 #define INPUT_IGNORE_EVENT 0
161 #define INPUT_PASS_TO_HANDLERS 1
162 #define INPUT_PASS_TO_DEVICE 2
163 #define INPUT_PASS_TO_ALL (INPUT_PASS_TO_HANDLERS | INPUT_PASS_TO_DEVICE)
165 static void input_handle_event(struct input_dev *dev,
166 unsigned int type, unsigned int code, int value)
168 int disposition = INPUT_IGNORE_EVENT;
170 switch (type) {
172 case EV_SYN:
173 switch (code) {
174 case SYN_CONFIG:
175 disposition = INPUT_PASS_TO_ALL;
176 break;
178 case SYN_REPORT:
179 if (!dev->sync) {
180 dev->sync = 1;
181 disposition = INPUT_PASS_TO_HANDLERS;
183 break;
184 case SYN_MT_REPORT:
185 dev->sync = 0;
186 disposition = INPUT_PASS_TO_HANDLERS;
187 break;
189 break;
191 case EV_KEY:
192 if (is_event_supported(code, dev->keybit, KEY_MAX) &&
193 !!test_bit(code, dev->key) != value) {
195 if (value != 2) {
196 __change_bit(code, dev->key);
197 if (value)
198 input_start_autorepeat(dev, code);
199 else
200 input_stop_autorepeat(dev);
203 disposition = INPUT_PASS_TO_HANDLERS;
205 break;
207 case EV_SW:
208 if (is_event_supported(code, dev->swbit, SW_MAX) &&
209 !!test_bit(code, dev->sw) != value) {
211 __change_bit(code, dev->sw);
212 disposition = INPUT_PASS_TO_HANDLERS;
214 break;
216 case EV_ABS:
217 if (is_event_supported(code, dev->absbit, ABS_MAX)) {
219 if (test_bit(code, input_abs_bypass)) {
220 disposition = INPUT_PASS_TO_HANDLERS;
221 break;
224 value = input_defuzz_abs_event(value,
225 dev->abs[code], dev->absfuzz[code]);
227 if (dev->abs[code] != value) {
228 dev->abs[code] = value;
229 disposition = INPUT_PASS_TO_HANDLERS;
232 break;
234 case EV_REL:
235 if (is_event_supported(code, dev->relbit, REL_MAX) && value)
236 disposition = INPUT_PASS_TO_HANDLERS;
238 break;
240 case EV_MSC:
241 if (is_event_supported(code, dev->mscbit, MSC_MAX))
242 disposition = INPUT_PASS_TO_ALL;
244 break;
246 case EV_LED:
247 if (is_event_supported(code, dev->ledbit, LED_MAX) &&
248 !!test_bit(code, dev->led) != value) {
250 __change_bit(code, dev->led);
251 disposition = INPUT_PASS_TO_ALL;
253 break;
255 case EV_SND:
256 if (is_event_supported(code, dev->sndbit, SND_MAX)) {
258 if (!!test_bit(code, dev->snd) != !!value)
259 __change_bit(code, dev->snd);
260 disposition = INPUT_PASS_TO_ALL;
262 break;
264 case EV_REP:
265 if (code <= REP_MAX && value >= 0 && dev->rep[code] != value) {
266 dev->rep[code] = value;
267 disposition = INPUT_PASS_TO_ALL;
269 break;
271 case EV_FF:
272 if (value >= 0)
273 disposition = INPUT_PASS_TO_ALL;
274 break;
276 case EV_PWR:
277 disposition = INPUT_PASS_TO_ALL;
278 break;
281 if (disposition != INPUT_IGNORE_EVENT && type != EV_SYN)
282 dev->sync = 0;
284 if ((disposition & INPUT_PASS_TO_DEVICE) && dev->event)
285 dev->event(dev, type, code, value);
287 if (disposition & INPUT_PASS_TO_HANDLERS)
288 input_pass_event(dev, type, code, value);
292 * input_event() - report new input event
293 * @dev: device that generated the event
294 * @type: type of the event
295 * @code: event code
296 * @value: value of the event
298 * This function should be used by drivers implementing various input
299 * devices. See also input_inject_event().
302 void input_event(struct input_dev *dev,
303 unsigned int type, unsigned int code, int value)
305 unsigned long flags;
307 if (is_event_supported(type, dev->evbit, EV_MAX)) {
309 spin_lock_irqsave(&dev->event_lock, flags);
310 add_input_randomness(type, code, value);
311 input_handle_event(dev, type, code, value);
312 spin_unlock_irqrestore(&dev->event_lock, flags);
315 EXPORT_SYMBOL(input_event);
318 * input_inject_event() - send input event from input handler
319 * @handle: input handle to send event through
320 * @type: type of the event
321 * @code: event code
322 * @value: value of the event
324 * Similar to input_event() but will ignore event if device is
325 * "grabbed" and handle injecting event is not the one that owns
326 * the device.
328 void input_inject_event(struct input_handle *handle,
329 unsigned int type, unsigned int code, int value)
331 struct input_dev *dev = handle->dev;
332 struct input_handle *grab;
333 unsigned long flags;
335 if (is_event_supported(type, dev->evbit, EV_MAX)) {
336 spin_lock_irqsave(&dev->event_lock, flags);
338 rcu_read_lock();
339 grab = rcu_dereference(dev->grab);
340 if (!grab || grab == handle)
341 input_handle_event(dev, type, code, value);
342 rcu_read_unlock();
344 spin_unlock_irqrestore(&dev->event_lock, flags);
347 EXPORT_SYMBOL(input_inject_event);
350 * input_grab_device - grabs device for exclusive use
351 * @handle: input handle that wants to own the device
353 * When a device is grabbed by an input handle all events generated by
354 * the device are delivered only to this handle. Also events injected
355 * by other input handles are ignored while device is grabbed.
357 int input_grab_device(struct input_handle *handle)
359 struct input_dev *dev = handle->dev;
360 int retval;
362 retval = mutex_lock_interruptible(&dev->mutex);
363 if (retval)
364 return retval;
366 if (dev->grab) {
367 retval = -EBUSY;
368 goto out;
371 rcu_assign_pointer(dev->grab, handle);
372 synchronize_rcu();
374 out:
375 mutex_unlock(&dev->mutex);
376 return retval;
378 EXPORT_SYMBOL(input_grab_device);
380 static void __input_release_device(struct input_handle *handle)
382 struct input_dev *dev = handle->dev;
384 if (dev->grab == handle) {
385 rcu_assign_pointer(dev->grab, NULL);
386 /* Make sure input_pass_event() notices that grab is gone */
387 synchronize_rcu();
389 list_for_each_entry(handle, &dev->h_list, d_node)
390 if (handle->open && handle->handler->start)
391 handle->handler->start(handle);
396 * input_release_device - release previously grabbed device
397 * @handle: input handle that owns the device
399 * Releases previously grabbed device so that other input handles can
400 * start receiving input events. Upon release all handlers attached
401 * to the device have their start() method called so they have a change
402 * to synchronize device state with the rest of the system.
404 void input_release_device(struct input_handle *handle)
406 struct input_dev *dev = handle->dev;
408 mutex_lock(&dev->mutex);
409 __input_release_device(handle);
410 mutex_unlock(&dev->mutex);
412 EXPORT_SYMBOL(input_release_device);
415 * input_open_device - open input device
416 * @handle: handle through which device is being accessed
418 * This function should be called by input handlers when they
419 * want to start receive events from given input device.
421 int input_open_device(struct input_handle *handle)
423 struct input_dev *dev = handle->dev;
424 int retval;
426 retval = mutex_lock_interruptible(&dev->mutex);
427 if (retval)
428 return retval;
430 if (dev->going_away) {
431 retval = -ENODEV;
432 goto out;
435 handle->open++;
437 if (!dev->users++ && dev->open)
438 retval = dev->open(dev);
440 if (retval) {
441 dev->users--;
442 if (!--handle->open) {
444 * Make sure we are not delivering any more events
445 * through this handle
447 synchronize_rcu();
451 out:
452 mutex_unlock(&dev->mutex);
453 return retval;
455 EXPORT_SYMBOL(input_open_device);
457 int input_flush_device(struct input_handle *handle, struct file *file)
459 struct input_dev *dev = handle->dev;
460 int retval;
462 retval = mutex_lock_interruptible(&dev->mutex);
463 if (retval)
464 return retval;
466 if (dev->flush)
467 retval = dev->flush(dev, file);
469 mutex_unlock(&dev->mutex);
470 return retval;
472 EXPORT_SYMBOL(input_flush_device);
475 * input_close_device - close input device
476 * @handle: handle through which device is being accessed
478 * This function should be called by input handlers when they
479 * want to stop receive events from given input device.
481 void input_close_device(struct input_handle *handle)
483 struct input_dev *dev = handle->dev;
485 mutex_lock(&dev->mutex);
487 __input_release_device(handle);
489 if (!--dev->users && dev->close)
490 dev->close(dev);
492 if (!--handle->open) {
494 * synchronize_rcu() makes sure that input_pass_event()
495 * completed and that no more input events are delivered
496 * through this handle
498 synchronize_rcu();
501 mutex_unlock(&dev->mutex);
503 EXPORT_SYMBOL(input_close_device);
506 * Prepare device for unregistering
508 static void input_disconnect_device(struct input_dev *dev)
510 struct input_handle *handle;
511 int code;
514 * Mark device as going away. Note that we take dev->mutex here
515 * not to protect access to dev->going_away but rather to ensure
516 * that there are no threads in the middle of input_open_device()
518 mutex_lock(&dev->mutex);
519 dev->going_away = true;
520 mutex_unlock(&dev->mutex);
522 spin_lock_irq(&dev->event_lock);
525 * Simulate keyup events for all pressed keys so that handlers
526 * are not left with "stuck" keys. The driver may continue
527 * generate events even after we done here but they will not
528 * reach any handlers.
530 if (is_event_supported(EV_KEY, dev->evbit, EV_MAX)) {
531 for (code = 0; code <= KEY_MAX; code++) {
532 if (is_event_supported(code, dev->keybit, KEY_MAX) &&
533 __test_and_clear_bit(code, dev->key)) {
534 input_pass_event(dev, EV_KEY, code, 0);
537 input_pass_event(dev, EV_SYN, SYN_REPORT, 1);
540 list_for_each_entry(handle, &dev->h_list, d_node)
541 handle->open = 0;
543 spin_unlock_irq(&dev->event_lock);
546 static int input_fetch_keycode(struct input_dev *dev, int scancode)
548 switch (dev->keycodesize) {
549 case 1:
550 return ((u8 *)dev->keycode)[scancode];
552 case 2:
553 return ((u16 *)dev->keycode)[scancode];
555 default:
556 return ((u32 *)dev->keycode)[scancode];
560 static int input_default_getkeycode(struct input_dev *dev,
561 int scancode, int *keycode)
563 if (!dev->keycodesize)
564 return -EINVAL;
566 if (scancode >= dev->keycodemax)
567 return -EINVAL;
569 *keycode = input_fetch_keycode(dev, scancode);
571 return 0;
574 static int input_default_setkeycode(struct input_dev *dev,
575 int scancode, int keycode)
577 int old_keycode;
578 int i;
580 if (scancode >= dev->keycodemax)
581 return -EINVAL;
583 if (!dev->keycodesize)
584 return -EINVAL;
586 if (dev->keycodesize < sizeof(keycode) && (keycode >> (dev->keycodesize * 8)))
587 return -EINVAL;
589 switch (dev->keycodesize) {
590 case 1: {
591 u8 *k = (u8 *)dev->keycode;
592 old_keycode = k[scancode];
593 k[scancode] = keycode;
594 break;
596 case 2: {
597 u16 *k = (u16 *)dev->keycode;
598 old_keycode = k[scancode];
599 k[scancode] = keycode;
600 break;
602 default: {
603 u32 *k = (u32 *)dev->keycode;
604 old_keycode = k[scancode];
605 k[scancode] = keycode;
606 break;
610 clear_bit(old_keycode, dev->keybit);
611 set_bit(keycode, dev->keybit);
613 for (i = 0; i < dev->keycodemax; i++) {
614 if (input_fetch_keycode(dev, i) == old_keycode) {
615 set_bit(old_keycode, dev->keybit);
616 break; /* Setting the bit twice is useless, so break */
620 return 0;
624 * input_get_keycode - retrieve keycode currently mapped to a given scancode
625 * @dev: input device which keymap is being queried
626 * @scancode: scancode (or its equivalent for device in question) for which
627 * keycode is needed
628 * @keycode: result
630 * This function should be called by anyone interested in retrieving current
631 * keymap. Presently keyboard and evdev handlers use it.
633 int input_get_keycode(struct input_dev *dev, int scancode, int *keycode)
635 if (scancode < 0)
636 return -EINVAL;
638 return dev->getkeycode(dev, scancode, keycode);
640 EXPORT_SYMBOL(input_get_keycode);
643 * input_get_keycode - assign new keycode to a given scancode
644 * @dev: input device which keymap is being updated
645 * @scancode: scancode (or its equivalent for device in question)
646 * @keycode: new keycode to be assigned to the scancode
648 * This function should be called by anyone needing to update current
649 * keymap. Presently keyboard and evdev handlers use it.
651 int input_set_keycode(struct input_dev *dev, int scancode, int keycode)
653 unsigned long flags;
654 int old_keycode;
655 int retval;
657 if (scancode < 0)
658 return -EINVAL;
660 if (keycode < 0 || keycode > KEY_MAX)
661 return -EINVAL;
663 spin_lock_irqsave(&dev->event_lock, flags);
665 retval = dev->getkeycode(dev, scancode, &old_keycode);
666 if (retval)
667 goto out;
669 retval = dev->setkeycode(dev, scancode, keycode);
670 if (retval)
671 goto out;
674 * Simulate keyup event if keycode is not present
675 * in the keymap anymore
677 if (test_bit(EV_KEY, dev->evbit) &&
678 !is_event_supported(old_keycode, dev->keybit, KEY_MAX) &&
679 __test_and_clear_bit(old_keycode, dev->key)) {
681 input_pass_event(dev, EV_KEY, old_keycode, 0);
682 if (dev->sync)
683 input_pass_event(dev, EV_SYN, SYN_REPORT, 1);
686 out:
687 spin_unlock_irqrestore(&dev->event_lock, flags);
689 return retval;
691 EXPORT_SYMBOL(input_set_keycode);
693 #define MATCH_BIT(bit, max) \
694 for (i = 0; i < BITS_TO_LONGS(max); i++) \
695 if ((id->bit[i] & dev->bit[i]) != id->bit[i]) \
696 break; \
697 if (i != BITS_TO_LONGS(max)) \
698 continue;
700 static const struct input_device_id *input_match_device(const struct input_device_id *id,
701 struct input_dev *dev)
703 int i;
705 for (; id->flags || id->driver_info; id++) {
707 if (id->flags & INPUT_DEVICE_ID_MATCH_BUS)
708 if (id->bustype != dev->id.bustype)
709 continue;
711 if (id->flags & INPUT_DEVICE_ID_MATCH_VENDOR)
712 if (id->vendor != dev->id.vendor)
713 continue;
715 if (id->flags & INPUT_DEVICE_ID_MATCH_PRODUCT)
716 if (id->product != dev->id.product)
717 continue;
719 if (id->flags & INPUT_DEVICE_ID_MATCH_VERSION)
720 if (id->version != dev->id.version)
721 continue;
723 MATCH_BIT(evbit, EV_MAX);
724 MATCH_BIT(keybit, KEY_MAX);
725 MATCH_BIT(relbit, REL_MAX);
726 MATCH_BIT(absbit, ABS_MAX);
727 MATCH_BIT(mscbit, MSC_MAX);
728 MATCH_BIT(ledbit, LED_MAX);
729 MATCH_BIT(sndbit, SND_MAX);
730 MATCH_BIT(ffbit, FF_MAX);
731 MATCH_BIT(swbit, SW_MAX);
733 return id;
736 return NULL;
739 static int input_attach_handler(struct input_dev *dev, struct input_handler *handler)
741 const struct input_device_id *id;
742 int error;
744 if (handler->blacklist && input_match_device(handler->blacklist, dev))
745 return -ENODEV;
747 id = input_match_device(handler->id_table, dev);
748 if (!id)
749 return -ENODEV;
751 error = handler->connect(handler, dev, id);
752 if (error && error != -ENODEV)
753 printk(KERN_ERR
754 "input: failed to attach handler %s to device %s, "
755 "error: %d\n",
756 handler->name, kobject_name(&dev->dev.kobj), error);
758 return error;
762 #ifdef CONFIG_PROC_FS
764 static struct proc_dir_entry *proc_bus_input_dir;
765 static DECLARE_WAIT_QUEUE_HEAD(input_devices_poll_wait);
766 static int input_devices_state;
768 static inline void input_wakeup_procfs_readers(void)
770 input_devices_state++;
771 wake_up(&input_devices_poll_wait);
774 static unsigned int input_proc_devices_poll(struct file *file, poll_table *wait)
776 poll_wait(file, &input_devices_poll_wait, wait);
777 if (file->f_version != input_devices_state) {
778 file->f_version = input_devices_state;
779 return POLLIN | POLLRDNORM;
782 return 0;
785 union input_seq_state {
786 struct {
787 unsigned short pos;
788 bool mutex_acquired;
790 void *p;
793 static void *input_devices_seq_start(struct seq_file *seq, loff_t *pos)
795 union input_seq_state *state = (union input_seq_state *)&seq->private;
796 int error;
798 /* We need to fit into seq->private pointer */
799 BUILD_BUG_ON(sizeof(union input_seq_state) != sizeof(seq->private));
801 error = mutex_lock_interruptible(&input_mutex);
802 if (error) {
803 state->mutex_acquired = false;
804 return ERR_PTR(error);
807 state->mutex_acquired = true;
809 return seq_list_start(&input_dev_list, *pos);
812 static void *input_devices_seq_next(struct seq_file *seq, void *v, loff_t *pos)
814 return seq_list_next(v, &input_dev_list, pos);
817 static void input_seq_stop(struct seq_file *seq, void *v)
819 union input_seq_state *state = (union input_seq_state *)&seq->private;
821 if (state->mutex_acquired)
822 mutex_unlock(&input_mutex);
825 static void input_seq_print_bitmap(struct seq_file *seq, const char *name,
826 unsigned long *bitmap, int max)
828 int i;
830 for (i = BITS_TO_LONGS(max) - 1; i > 0; i--)
831 if (bitmap[i])
832 break;
834 seq_printf(seq, "B: %s=", name);
835 for (; i >= 0; i--)
836 seq_printf(seq, "%lx%s", bitmap[i], i > 0 ? " " : "");
837 seq_putc(seq, '\n');
840 static int input_devices_seq_show(struct seq_file *seq, void *v)
842 struct input_dev *dev = container_of(v, struct input_dev, node);
843 const char *path = kobject_get_path(&dev->dev.kobj, GFP_KERNEL);
844 struct input_handle *handle;
846 seq_printf(seq, "I: Bus=%04x Vendor=%04x Product=%04x Version=%04x\n",
847 dev->id.bustype, dev->id.vendor, dev->id.product, dev->id.version);
849 seq_printf(seq, "N: Name=\"%s\"\n", dev->name ? dev->name : "");
850 seq_printf(seq, "P: Phys=%s\n", dev->phys ? dev->phys : "");
851 seq_printf(seq, "S: Sysfs=%s\n", path ? path : "");
852 seq_printf(seq, "U: Uniq=%s\n", dev->uniq ? dev->uniq : "");
853 seq_printf(seq, "H: Handlers=");
855 list_for_each_entry(handle, &dev->h_list, d_node)
856 seq_printf(seq, "%s ", handle->name);
857 seq_putc(seq, '\n');
859 input_seq_print_bitmap(seq, "EV", dev->evbit, EV_MAX);
860 if (test_bit(EV_KEY, dev->evbit))
861 input_seq_print_bitmap(seq, "KEY", dev->keybit, KEY_MAX);
862 if (test_bit(EV_REL, dev->evbit))
863 input_seq_print_bitmap(seq, "REL", dev->relbit, REL_MAX);
864 if (test_bit(EV_ABS, dev->evbit))
865 input_seq_print_bitmap(seq, "ABS", dev->absbit, ABS_MAX);
866 if (test_bit(EV_MSC, dev->evbit))
867 input_seq_print_bitmap(seq, "MSC", dev->mscbit, MSC_MAX);
868 if (test_bit(EV_LED, dev->evbit))
869 input_seq_print_bitmap(seq, "LED", dev->ledbit, LED_MAX);
870 if (test_bit(EV_SND, dev->evbit))
871 input_seq_print_bitmap(seq, "SND", dev->sndbit, SND_MAX);
872 if (test_bit(EV_FF, dev->evbit))
873 input_seq_print_bitmap(seq, "FF", dev->ffbit, FF_MAX);
874 if (test_bit(EV_SW, dev->evbit))
875 input_seq_print_bitmap(seq, "SW", dev->swbit, SW_MAX);
877 seq_putc(seq, '\n');
879 kfree(path);
880 return 0;
883 static const struct seq_operations input_devices_seq_ops = {
884 .start = input_devices_seq_start,
885 .next = input_devices_seq_next,
886 .stop = input_seq_stop,
887 .show = input_devices_seq_show,
890 static int input_proc_devices_open(struct inode *inode, struct file *file)
892 return seq_open(file, &input_devices_seq_ops);
895 static const struct file_operations input_devices_fileops = {
896 .owner = THIS_MODULE,
897 .open = input_proc_devices_open,
898 .poll = input_proc_devices_poll,
899 .read = seq_read,
900 .llseek = seq_lseek,
901 .release = seq_release,
904 static void *input_handlers_seq_start(struct seq_file *seq, loff_t *pos)
906 union input_seq_state *state = (union input_seq_state *)&seq->private;
907 int error;
909 /* We need to fit into seq->private pointer */
910 BUILD_BUG_ON(sizeof(union input_seq_state) != sizeof(seq->private));
912 error = mutex_lock_interruptible(&input_mutex);
913 if (error) {
914 state->mutex_acquired = false;
915 return ERR_PTR(error);
918 state->mutex_acquired = true;
919 state->pos = *pos;
921 return seq_list_start(&input_handler_list, *pos);
924 static void *input_handlers_seq_next(struct seq_file *seq, void *v, loff_t *pos)
926 union input_seq_state *state = (union input_seq_state *)&seq->private;
928 state->pos = *pos + 1;
929 return seq_list_next(v, &input_handler_list, pos);
932 static int input_handlers_seq_show(struct seq_file *seq, void *v)
934 struct input_handler *handler = container_of(v, struct input_handler, node);
935 union input_seq_state *state = (union input_seq_state *)&seq->private;
937 seq_printf(seq, "N: Number=%u Name=%s", state->pos, handler->name);
938 if (handler->fops)
939 seq_printf(seq, " Minor=%d", handler->minor);
940 seq_putc(seq, '\n');
942 return 0;
945 static const struct seq_operations input_handlers_seq_ops = {
946 .start = input_handlers_seq_start,
947 .next = input_handlers_seq_next,
948 .stop = input_seq_stop,
949 .show = input_handlers_seq_show,
952 static int input_proc_handlers_open(struct inode *inode, struct file *file)
954 return seq_open(file, &input_handlers_seq_ops);
957 static const struct file_operations input_handlers_fileops = {
958 .owner = THIS_MODULE,
959 .open = input_proc_handlers_open,
960 .read = seq_read,
961 .llseek = seq_lseek,
962 .release = seq_release,
965 static int __init input_proc_init(void)
967 struct proc_dir_entry *entry;
969 proc_bus_input_dir = proc_mkdir("bus/input", NULL);
970 if (!proc_bus_input_dir)
971 return -ENOMEM;
973 entry = proc_create("devices", 0, proc_bus_input_dir,
974 &input_devices_fileops);
975 if (!entry)
976 goto fail1;
978 entry = proc_create("handlers", 0, proc_bus_input_dir,
979 &input_handlers_fileops);
980 if (!entry)
981 goto fail2;
983 return 0;
985 fail2: remove_proc_entry("devices", proc_bus_input_dir);
986 fail1: remove_proc_entry("bus/input", NULL);
987 return -ENOMEM;
990 static void input_proc_exit(void)
992 remove_proc_entry("devices", proc_bus_input_dir);
993 remove_proc_entry("handlers", proc_bus_input_dir);
994 remove_proc_entry("bus/input", NULL);
997 #else /* !CONFIG_PROC_FS */
998 static inline void input_wakeup_procfs_readers(void) { }
999 static inline int input_proc_init(void) { return 0; }
1000 static inline void input_proc_exit(void) { }
1001 #endif
1003 #define INPUT_DEV_STRING_ATTR_SHOW(name) \
1004 static ssize_t input_dev_show_##name(struct device *dev, \
1005 struct device_attribute *attr, \
1006 char *buf) \
1008 struct input_dev *input_dev = to_input_dev(dev); \
1010 return scnprintf(buf, PAGE_SIZE, "%s\n", \
1011 input_dev->name ? input_dev->name : ""); \
1013 static DEVICE_ATTR(name, S_IRUGO, input_dev_show_##name, NULL)
1015 INPUT_DEV_STRING_ATTR_SHOW(name);
1016 INPUT_DEV_STRING_ATTR_SHOW(phys);
1017 INPUT_DEV_STRING_ATTR_SHOW(uniq);
1019 static int input_print_modalias_bits(char *buf, int size,
1020 char name, unsigned long *bm,
1021 unsigned int min_bit, unsigned int max_bit)
1023 int len = 0, i;
1025 len += snprintf(buf, max(size, 0), "%c", name);
1026 for (i = min_bit; i < max_bit; i++)
1027 if (bm[BIT_WORD(i)] & BIT_MASK(i))
1028 len += snprintf(buf + len, max(size - len, 0), "%X,", i);
1029 return len;
1032 static int input_print_modalias(char *buf, int size, struct input_dev *id,
1033 int add_cr)
1035 int len;
1037 len = snprintf(buf, max(size, 0),
1038 "input:b%04Xv%04Xp%04Xe%04X-",
1039 id->id.bustype, id->id.vendor,
1040 id->id.product, id->id.version);
1042 len += input_print_modalias_bits(buf + len, size - len,
1043 'e', id->evbit, 0, EV_MAX);
1044 len += input_print_modalias_bits(buf + len, size - len,
1045 'k', id->keybit, KEY_MIN_INTERESTING, KEY_MAX);
1046 len += input_print_modalias_bits(buf + len, size - len,
1047 'r', id->relbit, 0, REL_MAX);
1048 len += input_print_modalias_bits(buf + len, size - len,
1049 'a', id->absbit, 0, ABS_MAX);
1050 len += input_print_modalias_bits(buf + len, size - len,
1051 'm', id->mscbit, 0, MSC_MAX);
1052 len += input_print_modalias_bits(buf + len, size - len,
1053 'l', id->ledbit, 0, LED_MAX);
1054 len += input_print_modalias_bits(buf + len, size - len,
1055 's', id->sndbit, 0, SND_MAX);
1056 len += input_print_modalias_bits(buf + len, size - len,
1057 'f', id->ffbit, 0, FF_MAX);
1058 len += input_print_modalias_bits(buf + len, size - len,
1059 'w', id->swbit, 0, SW_MAX);
1061 if (add_cr)
1062 len += snprintf(buf + len, max(size - len, 0), "\n");
1064 return len;
1067 static ssize_t input_dev_show_modalias(struct device *dev,
1068 struct device_attribute *attr,
1069 char *buf)
1071 struct input_dev *id = to_input_dev(dev);
1072 ssize_t len;
1074 len = input_print_modalias(buf, PAGE_SIZE, id, 1);
1076 return min_t(int, len, PAGE_SIZE);
1078 static DEVICE_ATTR(modalias, S_IRUGO, input_dev_show_modalias, NULL);
1080 static struct attribute *input_dev_attrs[] = {
1081 &dev_attr_name.attr,
1082 &dev_attr_phys.attr,
1083 &dev_attr_uniq.attr,
1084 &dev_attr_modalias.attr,
1085 NULL
1088 static struct attribute_group input_dev_attr_group = {
1089 .attrs = input_dev_attrs,
1092 #define INPUT_DEV_ID_ATTR(name) \
1093 static ssize_t input_dev_show_id_##name(struct device *dev, \
1094 struct device_attribute *attr, \
1095 char *buf) \
1097 struct input_dev *input_dev = to_input_dev(dev); \
1098 return scnprintf(buf, PAGE_SIZE, "%04x\n", input_dev->id.name); \
1100 static DEVICE_ATTR(name, S_IRUGO, input_dev_show_id_##name, NULL)
1102 INPUT_DEV_ID_ATTR(bustype);
1103 INPUT_DEV_ID_ATTR(vendor);
1104 INPUT_DEV_ID_ATTR(product);
1105 INPUT_DEV_ID_ATTR(version);
1107 static struct attribute *input_dev_id_attrs[] = {
1108 &dev_attr_bustype.attr,
1109 &dev_attr_vendor.attr,
1110 &dev_attr_product.attr,
1111 &dev_attr_version.attr,
1112 NULL
1115 static struct attribute_group input_dev_id_attr_group = {
1116 .name = "id",
1117 .attrs = input_dev_id_attrs,
1120 static int input_print_bitmap(char *buf, int buf_size, unsigned long *bitmap,
1121 int max, int add_cr)
1123 int i;
1124 int len = 0;
1126 for (i = BITS_TO_LONGS(max) - 1; i > 0; i--)
1127 if (bitmap[i])
1128 break;
1130 for (; i >= 0; i--)
1131 len += snprintf(buf + len, max(buf_size - len, 0),
1132 "%lx%s", bitmap[i], i > 0 ? " " : "");
1134 if (add_cr)
1135 len += snprintf(buf + len, max(buf_size - len, 0), "\n");
1137 return len;
1140 #define INPUT_DEV_CAP_ATTR(ev, bm) \
1141 static ssize_t input_dev_show_cap_##bm(struct device *dev, \
1142 struct device_attribute *attr, \
1143 char *buf) \
1145 struct input_dev *input_dev = to_input_dev(dev); \
1146 int len = input_print_bitmap(buf, PAGE_SIZE, \
1147 input_dev->bm##bit, ev##_MAX, 1); \
1148 return min_t(int, len, PAGE_SIZE); \
1150 static DEVICE_ATTR(bm, S_IRUGO, input_dev_show_cap_##bm, NULL)
1152 INPUT_DEV_CAP_ATTR(EV, ev);
1153 INPUT_DEV_CAP_ATTR(KEY, key);
1154 INPUT_DEV_CAP_ATTR(REL, rel);
1155 INPUT_DEV_CAP_ATTR(ABS, abs);
1156 INPUT_DEV_CAP_ATTR(MSC, msc);
1157 INPUT_DEV_CAP_ATTR(LED, led);
1158 INPUT_DEV_CAP_ATTR(SND, snd);
1159 INPUT_DEV_CAP_ATTR(FF, ff);
1160 INPUT_DEV_CAP_ATTR(SW, sw);
1162 static struct attribute *input_dev_caps_attrs[] = {
1163 &dev_attr_ev.attr,
1164 &dev_attr_key.attr,
1165 &dev_attr_rel.attr,
1166 &dev_attr_abs.attr,
1167 &dev_attr_msc.attr,
1168 &dev_attr_led.attr,
1169 &dev_attr_snd.attr,
1170 &dev_attr_ff.attr,
1171 &dev_attr_sw.attr,
1172 NULL
1175 static struct attribute_group input_dev_caps_attr_group = {
1176 .name = "capabilities",
1177 .attrs = input_dev_caps_attrs,
1180 static const struct attribute_group *input_dev_attr_groups[] = {
1181 &input_dev_attr_group,
1182 &input_dev_id_attr_group,
1183 &input_dev_caps_attr_group,
1184 NULL
1187 static void input_dev_release(struct device *device)
1189 struct input_dev *dev = to_input_dev(device);
1191 input_ff_destroy(dev);
1192 kfree(dev);
1194 module_put(THIS_MODULE);
1198 * Input uevent interface - loading event handlers based on
1199 * device bitfields.
1201 static int input_add_uevent_bm_var(struct kobj_uevent_env *env,
1202 const char *name, unsigned long *bitmap, int max)
1204 int len;
1206 if (add_uevent_var(env, "%s=", name))
1207 return -ENOMEM;
1209 len = input_print_bitmap(&env->buf[env->buflen - 1],
1210 sizeof(env->buf) - env->buflen,
1211 bitmap, max, 0);
1212 if (len >= (sizeof(env->buf) - env->buflen))
1213 return -ENOMEM;
1215 env->buflen += len;
1216 return 0;
1219 static int input_add_uevent_modalias_var(struct kobj_uevent_env *env,
1220 struct input_dev *dev)
1222 int len;
1224 if (add_uevent_var(env, "MODALIAS="))
1225 return -ENOMEM;
1227 len = input_print_modalias(&env->buf[env->buflen - 1],
1228 sizeof(env->buf) - env->buflen,
1229 dev, 0);
1230 if (len >= (sizeof(env->buf) - env->buflen))
1231 return -ENOMEM;
1233 env->buflen += len;
1234 return 0;
1237 #define INPUT_ADD_HOTPLUG_VAR(fmt, val...) \
1238 do { \
1239 int err = add_uevent_var(env, fmt, val); \
1240 if (err) \
1241 return err; \
1242 } while (0)
1244 #define INPUT_ADD_HOTPLUG_BM_VAR(name, bm, max) \
1245 do { \
1246 int err = input_add_uevent_bm_var(env, name, bm, max); \
1247 if (err) \
1248 return err; \
1249 } while (0)
1251 #define INPUT_ADD_HOTPLUG_MODALIAS_VAR(dev) \
1252 do { \
1253 int err = input_add_uevent_modalias_var(env, dev); \
1254 if (err) \
1255 return err; \
1256 } while (0)
1258 static int input_dev_uevent(struct device *device, struct kobj_uevent_env *env)
1260 struct input_dev *dev = to_input_dev(device);
1262 INPUT_ADD_HOTPLUG_VAR("PRODUCT=%x/%x/%x/%x",
1263 dev->id.bustype, dev->id.vendor,
1264 dev->id.product, dev->id.version);
1265 if (dev->name)
1266 INPUT_ADD_HOTPLUG_VAR("NAME=\"%s\"", dev->name);
1267 if (dev->phys)
1268 INPUT_ADD_HOTPLUG_VAR("PHYS=\"%s\"", dev->phys);
1269 if (dev->uniq)
1270 INPUT_ADD_HOTPLUG_VAR("UNIQ=\"%s\"", dev->uniq);
1272 INPUT_ADD_HOTPLUG_BM_VAR("EV=", dev->evbit, EV_MAX);
1273 if (test_bit(EV_KEY, dev->evbit))
1274 INPUT_ADD_HOTPLUG_BM_VAR("KEY=", dev->keybit, KEY_MAX);
1275 if (test_bit(EV_REL, dev->evbit))
1276 INPUT_ADD_HOTPLUG_BM_VAR("REL=", dev->relbit, REL_MAX);
1277 if (test_bit(EV_ABS, dev->evbit))
1278 INPUT_ADD_HOTPLUG_BM_VAR("ABS=", dev->absbit, ABS_MAX);
1279 if (test_bit(EV_MSC, dev->evbit))
1280 INPUT_ADD_HOTPLUG_BM_VAR("MSC=", dev->mscbit, MSC_MAX);
1281 if (test_bit(EV_LED, dev->evbit))
1282 INPUT_ADD_HOTPLUG_BM_VAR("LED=", dev->ledbit, LED_MAX);
1283 if (test_bit(EV_SND, dev->evbit))
1284 INPUT_ADD_HOTPLUG_BM_VAR("SND=", dev->sndbit, SND_MAX);
1285 if (test_bit(EV_FF, dev->evbit))
1286 INPUT_ADD_HOTPLUG_BM_VAR("FF=", dev->ffbit, FF_MAX);
1287 if (test_bit(EV_SW, dev->evbit))
1288 INPUT_ADD_HOTPLUG_BM_VAR("SW=", dev->swbit, SW_MAX);
1290 INPUT_ADD_HOTPLUG_MODALIAS_VAR(dev);
1292 return 0;
1295 #define INPUT_DO_TOGGLE(dev, type, bits, on) \
1296 do { \
1297 int i; \
1298 if (!test_bit(EV_##type, dev->evbit)) \
1299 break; \
1300 for (i = 0; i < type##_MAX; i++) { \
1301 if (!test_bit(i, dev->bits##bit) || \
1302 !test_bit(i, dev->bits)) \
1303 continue; \
1304 dev->event(dev, EV_##type, i, on); \
1306 } while (0)
1308 #ifdef CONFIG_PM
1309 static void input_dev_reset(struct input_dev *dev, bool activate)
1311 if (!dev->event)
1312 return;
1314 INPUT_DO_TOGGLE(dev, LED, led, activate);
1315 INPUT_DO_TOGGLE(dev, SND, snd, activate);
1317 if (activate && test_bit(EV_REP, dev->evbit)) {
1318 dev->event(dev, EV_REP, REP_PERIOD, dev->rep[REP_PERIOD]);
1319 dev->event(dev, EV_REP, REP_DELAY, dev->rep[REP_DELAY]);
1323 static int input_dev_suspend(struct device *dev)
1325 struct input_dev *input_dev = to_input_dev(dev);
1327 mutex_lock(&input_dev->mutex);
1328 input_dev_reset(input_dev, false);
1329 mutex_unlock(&input_dev->mutex);
1331 return 0;
1334 static int input_dev_resume(struct device *dev)
1336 struct input_dev *input_dev = to_input_dev(dev);
1338 mutex_lock(&input_dev->mutex);
1339 input_dev_reset(input_dev, true);
1340 mutex_unlock(&input_dev->mutex);
1342 return 0;
1345 static const struct dev_pm_ops input_dev_pm_ops = {
1346 .suspend = input_dev_suspend,
1347 .resume = input_dev_resume,
1348 .poweroff = input_dev_suspend,
1349 .restore = input_dev_resume,
1351 #endif /* CONFIG_PM */
1353 static struct device_type input_dev_type = {
1354 .groups = input_dev_attr_groups,
1355 .release = input_dev_release,
1356 .uevent = input_dev_uevent,
1357 #ifdef CONFIG_PM
1358 .pm = &input_dev_pm_ops,
1359 #endif
1362 static char *input_devnode(struct device *dev, mode_t *mode)
1364 return kasprintf(GFP_KERNEL, "input/%s", dev_name(dev));
1367 struct class input_class = {
1368 .name = "input",
1369 .devnode = input_devnode,
1371 EXPORT_SYMBOL_GPL(input_class);
1374 * input_allocate_device - allocate memory for new input device
1376 * Returns prepared struct input_dev or NULL.
1378 * NOTE: Use input_free_device() to free devices that have not been
1379 * registered; input_unregister_device() should be used for already
1380 * registered devices.
1382 struct input_dev *input_allocate_device(void)
1384 struct input_dev *dev;
1386 dev = kzalloc(sizeof(struct input_dev), GFP_KERNEL);
1387 if (dev) {
1388 dev->dev.type = &input_dev_type;
1389 dev->dev.class = &input_class;
1390 device_initialize(&dev->dev);
1391 mutex_init(&dev->mutex);
1392 spin_lock_init(&dev->event_lock);
1393 INIT_LIST_HEAD(&dev->h_list);
1394 INIT_LIST_HEAD(&dev->node);
1396 __module_get(THIS_MODULE);
1399 return dev;
1401 EXPORT_SYMBOL(input_allocate_device);
1404 * input_free_device - free memory occupied by input_dev structure
1405 * @dev: input device to free
1407 * This function should only be used if input_register_device()
1408 * was not called yet or if it failed. Once device was registered
1409 * use input_unregister_device() and memory will be freed once last
1410 * reference to the device is dropped.
1412 * Device should be allocated by input_allocate_device().
1414 * NOTE: If there are references to the input device then memory
1415 * will not be freed until last reference is dropped.
1417 void input_free_device(struct input_dev *dev)
1419 if (dev)
1420 input_put_device(dev);
1422 EXPORT_SYMBOL(input_free_device);
1425 * input_set_capability - mark device as capable of a certain event
1426 * @dev: device that is capable of emitting or accepting event
1427 * @type: type of the event (EV_KEY, EV_REL, etc...)
1428 * @code: event code
1430 * In addition to setting up corresponding bit in appropriate capability
1431 * bitmap the function also adjusts dev->evbit.
1433 void input_set_capability(struct input_dev *dev, unsigned int type, unsigned int code)
1435 switch (type) {
1436 case EV_KEY:
1437 __set_bit(code, dev->keybit);
1438 break;
1440 case EV_REL:
1441 __set_bit(code, dev->relbit);
1442 break;
1444 case EV_ABS:
1445 __set_bit(code, dev->absbit);
1446 break;
1448 case EV_MSC:
1449 __set_bit(code, dev->mscbit);
1450 break;
1452 case EV_SW:
1453 __set_bit(code, dev->swbit);
1454 break;
1456 case EV_LED:
1457 __set_bit(code, dev->ledbit);
1458 break;
1460 case EV_SND:
1461 __set_bit(code, dev->sndbit);
1462 break;
1464 case EV_FF:
1465 __set_bit(code, dev->ffbit);
1466 break;
1468 case EV_PWR:
1469 /* do nothing */
1470 break;
1472 default:
1473 printk(KERN_ERR
1474 "input_set_capability: unknown type %u (code %u)\n",
1475 type, code);
1476 dump_stack();
1477 return;
1480 __set_bit(type, dev->evbit);
1482 EXPORT_SYMBOL(input_set_capability);
1485 * input_register_device - register device with input core
1486 * @dev: device to be registered
1488 * This function registers device with input core. The device must be
1489 * allocated with input_allocate_device() and all it's capabilities
1490 * set up before registering.
1491 * If function fails the device must be freed with input_free_device().
1492 * Once device has been successfully registered it can be unregistered
1493 * with input_unregister_device(); input_free_device() should not be
1494 * called in this case.
1496 int input_register_device(struct input_dev *dev)
1498 static atomic_t input_no = ATOMIC_INIT(0);
1499 struct input_handler *handler;
1500 const char *path;
1501 int error;
1503 __set_bit(EV_SYN, dev->evbit);
1506 * If delay and period are pre-set by the driver, then autorepeating
1507 * is handled by the driver itself and we don't do it in input.c.
1510 init_timer(&dev->timer);
1511 if (!dev->rep[REP_DELAY] && !dev->rep[REP_PERIOD]) {
1512 dev->timer.data = (long) dev;
1513 dev->timer.function = input_repeat_key;
1514 dev->rep[REP_DELAY] = 250;
1515 dev->rep[REP_PERIOD] = 33;
1518 if (!dev->getkeycode)
1519 dev->getkeycode = input_default_getkeycode;
1521 if (!dev->setkeycode)
1522 dev->setkeycode = input_default_setkeycode;
1524 dev_set_name(&dev->dev, "input%ld",
1525 (unsigned long) atomic_inc_return(&input_no) - 1);
1527 error = device_add(&dev->dev);
1528 if (error)
1529 return error;
1531 path = kobject_get_path(&dev->dev.kobj, GFP_KERNEL);
1532 printk(KERN_INFO "input: %s as %s\n",
1533 dev->name ? dev->name : "Unspecified device", path ? path : "N/A");
1534 kfree(path);
1536 error = mutex_lock_interruptible(&input_mutex);
1537 if (error) {
1538 device_del(&dev->dev);
1539 return error;
1542 list_add_tail(&dev->node, &input_dev_list);
1544 list_for_each_entry(handler, &input_handler_list, node)
1545 input_attach_handler(dev, handler);
1547 input_wakeup_procfs_readers();
1549 mutex_unlock(&input_mutex);
1551 return 0;
1553 EXPORT_SYMBOL(input_register_device);
1556 * input_unregister_device - unregister previously registered device
1557 * @dev: device to be unregistered
1559 * This function unregisters an input device. Once device is unregistered
1560 * the caller should not try to access it as it may get freed at any moment.
1562 void input_unregister_device(struct input_dev *dev)
1564 struct input_handle *handle, *next;
1566 input_disconnect_device(dev);
1568 mutex_lock(&input_mutex);
1570 list_for_each_entry_safe(handle, next, &dev->h_list, d_node)
1571 handle->handler->disconnect(handle);
1572 WARN_ON(!list_empty(&dev->h_list));
1574 del_timer_sync(&dev->timer);
1575 list_del_init(&dev->node);
1577 input_wakeup_procfs_readers();
1579 mutex_unlock(&input_mutex);
1581 device_unregister(&dev->dev);
1583 EXPORT_SYMBOL(input_unregister_device);
1586 * input_register_handler - register a new input handler
1587 * @handler: handler to be registered
1589 * This function registers a new input handler (interface) for input
1590 * devices in the system and attaches it to all input devices that
1591 * are compatible with the handler.
1593 int input_register_handler(struct input_handler *handler)
1595 struct input_dev *dev;
1596 int retval;
1598 retval = mutex_lock_interruptible(&input_mutex);
1599 if (retval)
1600 return retval;
1602 INIT_LIST_HEAD(&handler->h_list);
1604 if (handler->fops != NULL) {
1605 if (input_table[handler->minor >> 5]) {
1606 retval = -EBUSY;
1607 goto out;
1609 input_table[handler->minor >> 5] = handler;
1612 list_add_tail(&handler->node, &input_handler_list);
1614 list_for_each_entry(dev, &input_dev_list, node)
1615 input_attach_handler(dev, handler);
1617 input_wakeup_procfs_readers();
1619 out:
1620 mutex_unlock(&input_mutex);
1621 return retval;
1623 EXPORT_SYMBOL(input_register_handler);
1626 * input_unregister_handler - unregisters an input handler
1627 * @handler: handler to be unregistered
1629 * This function disconnects a handler from its input devices and
1630 * removes it from lists of known handlers.
1632 void input_unregister_handler(struct input_handler *handler)
1634 struct input_handle *handle, *next;
1636 mutex_lock(&input_mutex);
1638 list_for_each_entry_safe(handle, next, &handler->h_list, h_node)
1639 handler->disconnect(handle);
1640 WARN_ON(!list_empty(&handler->h_list));
1642 list_del_init(&handler->node);
1644 if (handler->fops != NULL)
1645 input_table[handler->minor >> 5] = NULL;
1647 input_wakeup_procfs_readers();
1649 mutex_unlock(&input_mutex);
1651 EXPORT_SYMBOL(input_unregister_handler);
1654 * input_register_handle - register a new input handle
1655 * @handle: handle to register
1657 * This function puts a new input handle onto device's
1658 * and handler's lists so that events can flow through
1659 * it once it is opened using input_open_device().
1661 * This function is supposed to be called from handler's
1662 * connect() method.
1664 int input_register_handle(struct input_handle *handle)
1666 struct input_handler *handler = handle->handler;
1667 struct input_dev *dev = handle->dev;
1668 int error;
1671 * We take dev->mutex here to prevent race with
1672 * input_release_device().
1674 error = mutex_lock_interruptible(&dev->mutex);
1675 if (error)
1676 return error;
1677 list_add_tail_rcu(&handle->d_node, &dev->h_list);
1678 mutex_unlock(&dev->mutex);
1681 * Since we are supposed to be called from ->connect()
1682 * which is mutually exclusive with ->disconnect()
1683 * we can't be racing with input_unregister_handle()
1684 * and so separate lock is not needed here.
1686 list_add_tail(&handle->h_node, &handler->h_list);
1688 if (handler->start)
1689 handler->start(handle);
1691 return 0;
1693 EXPORT_SYMBOL(input_register_handle);
1696 * input_unregister_handle - unregister an input handle
1697 * @handle: handle to unregister
1699 * This function removes input handle from device's
1700 * and handler's lists.
1702 * This function is supposed to be called from handler's
1703 * disconnect() method.
1705 void input_unregister_handle(struct input_handle *handle)
1707 struct input_dev *dev = handle->dev;
1709 list_del_init(&handle->h_node);
1712 * Take dev->mutex to prevent race with input_release_device().
1714 mutex_lock(&dev->mutex);
1715 list_del_rcu(&handle->d_node);
1716 mutex_unlock(&dev->mutex);
1717 synchronize_rcu();
1719 EXPORT_SYMBOL(input_unregister_handle);
1721 static int input_open_file(struct inode *inode, struct file *file)
1723 struct input_handler *handler;
1724 const struct file_operations *old_fops, *new_fops = NULL;
1725 int err;
1727 lock_kernel();
1728 /* No load-on-demand here? */
1729 handler = input_table[iminor(inode) >> 5];
1730 if (!handler || !(new_fops = fops_get(handler->fops))) {
1731 err = -ENODEV;
1732 goto out;
1736 * That's _really_ odd. Usually NULL ->open means "nothing special",
1737 * not "no device". Oh, well...
1739 if (!new_fops->open) {
1740 fops_put(new_fops);
1741 err = -ENODEV;
1742 goto out;
1744 old_fops = file->f_op;
1745 file->f_op = new_fops;
1747 err = new_fops->open(inode, file);
1749 if (err) {
1750 fops_put(file->f_op);
1751 file->f_op = fops_get(old_fops);
1753 fops_put(old_fops);
1754 out:
1755 unlock_kernel();
1756 return err;
1759 static const struct file_operations input_fops = {
1760 .owner = THIS_MODULE,
1761 .open = input_open_file,
1764 static void __init input_init_abs_bypass(void)
1766 const unsigned int *p;
1768 for (p = input_abs_bypass_init_data; *p; p++)
1769 input_abs_bypass[BIT_WORD(*p)] |= BIT_MASK(*p);
1772 static int __init input_init(void)
1774 int err;
1776 input_init_abs_bypass();
1778 err = class_register(&input_class);
1779 if (err) {
1780 printk(KERN_ERR "input: unable to register input_dev class\n");
1781 return err;
1784 err = input_proc_init();
1785 if (err)
1786 goto fail1;
1788 err = register_chrdev(INPUT_MAJOR, "input", &input_fops);
1789 if (err) {
1790 printk(KERN_ERR "input: unable to register char major %d", INPUT_MAJOR);
1791 goto fail2;
1794 return 0;
1796 fail2: input_proc_exit();
1797 fail1: class_unregister(&input_class);
1798 return err;
1801 static void __exit input_exit(void)
1803 input_proc_exit();
1804 unregister_chrdev(INPUT_MAJOR, "input");
1805 class_unregister(&input_class);
1808 subsys_initcall(input_init);
1809 module_exit(input_exit);