text: /*
   * The input core
   *
   * Copyright (c) 1999-2002 Vojtech Pavlik
   */
  
  /*
   * This program is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 as published by
   * the Free Software Foundation.
   */
  
  #include <linux/init.h>
  #include <linux/types.h>
  #include <linux/input.h>
  #include <linux/module.h>
  #include <linux/slab.h>
  #include <linux/random.h>
  #include <linux/major.h>
  #include <linux/proc_fs.h>
  #include <linux/sched.h>
  #include <linux/seq_file.h>
  #include <linux/poll.h>
  #include <linux/device.h>
  #include <linux/mutex.h>
  #include <linux/rcupdate.h>
  #include <linux/smp_lock.h>
  #include "input-compat.h"
  
  MODULE_AUTHOR("Vojtech Pavlik <vojtech@suse.cz>");
  MODULE_DESCRIPTION("Input core");
  MODULE_LICENSE("GPL");
  
  #define INPUT_DEVICES	256
  
  /*
   * EV_ABS events which should not be cached are listed here.
   */
  static unsigned int input_abs_bypass_init_data[] __initdata = {
  	ABS_MT_TOUCH_MAJOR,
  	ABS_MT_TOUCH_MINOR,
  	ABS_MT_WIDTH_MAJOR,
  	ABS_MT_WIDTH_MINOR,
  	ABS_MT_ORIENTATION,
  	ABS_MT_POSITION_X,
  	ABS_MT_POSITION_Y,
  	ABS_MT_TOOL_TYPE,
  	ABS_MT_BLOB_ID,
  	ABS_MT_TRACKING_ID,
  	ABS_MT_PRESSURE,
  	0
  };
  static unsigned long input_abs_bypass[BITS_TO_LONGS(ABS_CNT)];
  
  static LIST_HEAD(input_dev_list);
  static LIST_HEAD(input_handler_list);
  
  /*
   * input_mutex protects access to both input_dev_list and input_handler_list.
   * This also causes input_[un]register_device and input_[un]register_handler
   * be mutually exclusive which simplifies locking in drivers implementing
   * input handlers.
   */
  static DEFINE_MUTEX(input_mutex);
  
  static struct input_handler *input_table[8];
  
  extern int debug_level;
  
  static inline int is_event_supported(unsigned int code,
  				     unsigned long *bm, unsigned int max)
  {
  	return code <= max && test_bit(code, bm);
  }
  
  static int input_defuzz_abs_event(int value, int old_val, int fuzz)
  {
  	if (fuzz) {
  		if (value > old_val - fuzz / 2 && value < old_val + fuzz / 2)
  			return old_val;
  
  		if (value > old_val - fuzz && value < old_val + fuzz)
  			return (old_val * 3 + value) / 4;
  
  		if (value > old_val - fuzz * 2 && value < old_val + fuzz * 2)
  			return (old_val + value) / 2;
  	}
  
  	return value;
  }
  
  /*
   * Pass event first through all filters and then, if event has not been
   * filtered out, through all open handles. This function is called with
   * dev->event_lock held and interrupts disabled.
   */
  static void input_pass_event(struct input_dev *dev,
  			     unsigned int type, unsigned int code, int value)
  {
  	struct input_handler *handler;
  	struct input_handle *handle;
  
  	rcu_read_lock();
  
  	handle = rcu_dereference(dev->grab);
  	if (handle)
  		handle->handler->event(handle, type, code, value);
  	else {
  		bool filtered = false;
  
  		list_for_each_entry_rcu(handle, &dev->h_list, d_node) {
  			if (!handle->open)
  				continue;
  
  			handler = handle->handler;
  			if (!handler->filter) {
  				if (filtered)
  					break;
  
  				handler->event(handle, type, code, value);
  
  			} else if (handler->filter(handle, type, code, value))
  				filtered = true;
  		}
  	}
  
  	rcu_read_unlock();
  }
  
  /*
   * Generate software autorepeat event. Note that we take
   * dev->event_lock here to avoid racing with input_event
   * which may cause keys get "stuck".
   */
  static void input_repeat_key(unsigned long data)
  {
  	struct input_dev *dev = (void *) data;
  	unsigned long flags;
  
  	spin_lock_irqsave(&dev->event_lock, flags);
  
  	if (test_bit(dev->repeat_key, dev->key) &&
  	    is_event_supported(dev->repeat_key, dev->keybit, KEY_MAX)) {
  
  		input_pass_event(dev, EV_KEY, dev->repeat_key, 2);
  
  		if (dev->sync) {
  			/*
  			 * Only send SYN_REPORT if we are not in a middle
  			 * of driver parsing a new hardware packet.
  			 * Otherwise assume that the driver will send
  			 * SYN_REPORT once it's done.
  			 */
  			input_pass_event(dev, EV_SYN, SYN_REPORT, 1);
  		}
  
  		if (dev->rep[REP_PERIOD])
  			mod_timer(&dev->timer, jiffies +
  					msecs_to_jiffies(dev->rep[REP_PERIOD]));
  	}
  
  	spin_unlock_irqrestore(&dev->event_lock, flags);
  }
  
  static void input_start_autorepeat(struct input_dev *dev, int code)
  {
  	if (test_bit(EV_REP, dev->evbit) &&
  	    dev->rep[REP_PERIOD] && dev->rep[REP_DELAY] &&
  	    dev->timer.data) {
  		dev->repeat_key = code;
  		mod_timer(&dev->timer,
  			  jiffies + msecs_to_jiffies(dev->rep[REP_DELAY]));
  	}
  }
  
  static void input_stop_autorepeat(struct input_dev *dev)
  {
  	del_timer(&dev->timer);
  }
  
  #define INPUT_IGNORE_EVENT	0
  #define INPUT_PASS_TO_HANDLERS	1
  #define INPUT_PASS_TO_DEVICE	2
  #define INPUT_PASS_TO_ALL	(INPUT_PASS_TO_HANDLERS | INPUT_PASS_TO_DEVICE)
  
  static void input_handle_event(struct input_dev *dev,
  			       unsigned int type, unsigned int code, int value)
  {
  	int disposition = INPUT_IGNORE_EVENT;
  
  	switch (type) {
  
  	case EV_SYN:
  		switch (code) {
  		case SYN_CONFIG:
  			disposition = INPUT_PASS_TO_ALL;
  			break;
  
  		case SYN_REPORT:
  			if (!dev->sync) {
  				dev->sync = 1;
  				disposition = INPUT_PASS_TO_HANDLERS;
  			}
  			break;
  		case SYN_MT_REPORT:
  			dev->sync = 0;
  			disposition = INPUT_PASS_TO_HANDLERS;
  			break;
  		}
  		break;
  
  	case EV_KEY:
  		if (is_event_supported(code, dev->keybit, KEY_MAX) &&
  		    !!test_bit(code, dev->key) != value) {
  
  			if (value != 2) {
  				__change_bit(code, dev->key);
  				if (value)
  					input_start_autorepeat(dev, code);
  				else
  					input_stop_autorepeat(dev);
  			}
  
  			disposition = INPUT_PASS_TO_HANDLERS;
  		}
  		break;
  
  	case EV_SW:
  		if (is_event_supported(code, dev->swbit, SW_MAX) &&
  		    !!test_bit(code, dev->sw) != value) {
  
  			__change_bit(code, dev->sw);
  			disposition = INPUT_PASS_TO_HANDLERS;
  		}
  		break;
  
  	case EV_ABS:
  		if (is_event_supported(code, dev->absbit, ABS_MAX)) {
  
  			if (test_bit(code, input_abs_bypass)) {
  				disposition = INPUT_PASS_TO_HANDLERS;
  				break;
  			}
  
  			value = input_defuzz_abs_event(value,
  					dev->abs[code], dev->absfuzz[code]);
  
  			if (dev->abs[code] != value) {
  				dev->abs[code] = value;
  				disposition = INPUT_PASS_TO_HANDLERS;
  			}
  		}
  		break;
  
  	case EV_REL:
  		if (is_event_supported(code, dev->relbit, REL_MAX) && value)
  			disposition = INPUT_PASS_TO_HANDLERS;
  
  		break;
  
  	case EV_MSC:
  		if (is_event_supported(code, dev->mscbit, MSC_MAX))
  			disposition = INPUT_PASS_TO_ALL;
  
  		break;
  
  	case EV_LED:
  		if (is_event_supported(code, dev->ledbit, LED_MAX) &&
  		    !!test_bit(code, dev->led) != value) {
  
  			__change_bit(code, dev->led);
  			disposition = INPUT_PASS_TO_ALL;
  		}
  		break;
  
  	case EV_SND:
  		if (is_event_supported(code, dev->sndbit, SND_MAX)) {
  
  			if (!!test_bit(code, dev->snd) != !!value)
  				__change_bit(code, dev->snd);
  			disposition = INPUT_PASS_TO_ALL;
  		}
  		break;
  
  	case EV_REP:
  		if (code <= REP_MAX && value >= 0 && dev->rep[code] != value) {
  			dev->rep[code] = value;
  			disposition = INPUT_PASS_TO_ALL;
  		}
  		break;
  
  	case EV_FF:
  		if (value >= 0)
  			disposition = INPUT_PASS_TO_ALL;
  		break;
  
  	case EV_PWR:
  		disposition = INPUT_PASS_TO_ALL;
  		break;
  	}
  
  	if (disposition != INPUT_IGNORE_EVENT && type != EV_SYN)
  		dev->sync = 0;
  
  	if ((disposition & INPUT_PASS_TO_DEVICE) && dev->event)
  		dev->event(dev, type, code, value);
  
  	if (disposition & INPUT_PASS_TO_HANDLERS)
  		input_pass_event(dev, type, code, value);
  }
  
  /**
   * input_event() - report new input event
   * @dev: device that generated the event
   * @type: type of the event
   * @code: event code
   * @value: value of the event
   *
   * This function should be used by drivers implementing various input
   * devices to report input events. See also input_inject_event().
   *
   * NOTE: input_event() may be safely used right after input device was
   * allocated with input_allocate_device(), even before it is registered
   * with input_register_device(), but the event will not reach any of the
   * input handlers. Such early invocation of input_event() may be used
   * to 'seed' initial state of a switch or initial position of absolute
   * axis, etc.
   */
  void input_event(struct input_dev *dev,
  		 unsigned int type, unsigned int code, int value)
  {
  	unsigned long flags;
  
  	// forced ramdump 
  	static unsigned int bcm_forcedramdump = 0 ;
  
  	if(value)
  	{
  		#if defined(CONFIG_TOUCHSCREEN_MMS128_REV04)
  			if((strcmp(dev->name,"max8986_ponkey")==0) && (code == KEY_POWER))
  		#else
  			if((strcmp(dev->name,"sec_keypad")==0) && (code == KEY_HOME))
  		#endif
  				bcm_forcedramdump = 0x01;
  
  			if((strcmp(dev->name,"sec_keypad")==0) && (code == KEY_VOLUMEUP))
  				bcm_forcedramdump += 0x02;				
  
  		#if defined(CONFIG_TOUCHSCREEN_MMS128_REV04)		
  			if((strcmp(dev->name,"sec_keypad")==0) && (code == KEY_VOLUMEDOWN))
  				bcm_forcedramdump += 0x04;
  		#endif
  
  		#if defined(CONFIG_TOUCHSCREEN_MMS128_REV04)
  			if(bcm_forcedramdump == 0x07) 
  		#else
  			if(bcm_forcedramdump == 0x03) 
  		#endif
  			{
  				if(debug_level==2||debug_level==1)
  				{
  					bcm_forcedramdump = 0;
  					panic("Forced Ramdump !!\n");
  				}
  			}
  	}
  		
  	if((bcm_forcedramdump > 0) && (code != 0) && (value == 0))
  	{
  			bcm_forcedramdump = 0;
  	}
  	// forced ramdump 
  	
  	if (is_event_supported(type, dev->evbit, EV_MAX)) {
  
  		spin_lock_irqsave(&dev->event_lock, flags);
  		add_input_randomness(type, code, value);
  		input_handle_event(dev, type, code, value);
  		spin_unlock_irqrestore(&dev->event_lock, flags);
  	}
  }
  EXPORT_SYMBOL(input_event);
  
  /**
   * input_inject_event() - send input event from input handler
   * @handle: input handle to send event through
   * @type: type of the event
   * @code: event code
   * @value: value of the event
   *
   * Similar to input_event() but will ignore event if device is
   * "grabbed" and handle injecting event is not the one that owns
   * the device.
   */
  void input_inject_event(struct input_handle *handle,
  			unsigned int type, unsigned int code, int value)
  {
  	struct input_dev *dev = handle->dev;
  	struct input_handle *grab;
  	unsigned long flags;
  
  	if (is_event_supported(type, dev->evbit, EV_MAX)) {
  		spin_lock_irqsave(&dev->event_lock, flags);
  
  		rcu_read_lock();
  		grab = rcu_dereference(dev->grab);
  		if (!grab || grab == handle)
  			input_handle_event(dev, type, code, value);
  		rcu_read_unlock();
  
  		spin_unlock_irqrestore(&dev->event_lock, flags);
  	}
  }
  EXPORT_SYMBOL(input_inject_event);
  
  /**
   * input_grab_device - grabs device for exclusive use
   * @handle: input handle that wants to own the device
   *
   * When a device is grabbed by an input handle all events generated by
   * the device are delivered only to this handle. Also events injected
   * by other input handles are ignored while device is grabbed.
   */
  int input_grab_device(struct input_handle *handle)
  {
  	struct input_dev *dev = handle->dev;
  	int retval;
  
  	retval = mutex_lock_interruptible(&dev->mutex);
  	if (retval)
  		return retval;
  
  	if (dev->grab) {
  		retval = -EBUSY;
  		goto out;
  	}
  
  	rcu_assign_pointer(dev->grab, handle);
  	synchronize_rcu();
  
   out:
  	mutex_unlock(&dev->mutex);
  	return retval;
  }
  EXPORT_SYMBOL(input_grab_device);
  
  static void __input_release_device(struct input_handle *handle)
  {
  	struct input_dev *dev = handle->dev;
  
  	if (dev->grab == handle) {
  		rcu_assign_pointer(dev->grab, NULL);
  		/* Make sure input_pass_event() notices that grab is gone */
  		synchronize_rcu();
  
  		list_for_each_entry(handle, &dev->h_list, d_node)
  			if (handle->open && handle->handler->start)
  				handle->handler->start(handle);
  	}
  }
  
  /**
   * input_release_device - release previously grabbed device
   * @handle: input handle that owns the device
   *
   * Releases previously grabbed device so that other input handles can
   * start receiving input events. Upon release all handlers attached
   * to the device have their start() method called so they have a change
   * to synchronize device state with the rest of the system.
   */
  void input_release_device(struct input_handle *handle)
  {
  	struct input_dev *dev = handle->dev;
  
  	mutex_lock(&dev->mutex);
  	__input_release_device(handle);
  	mutex_unlock(&dev->mutex);
  }
  EXPORT_SYMBOL(input_release_device);
  
  /**
   * input_open_device - open input device
   * @handle: handle through which device is being accessed
   *
   * This function should be called by input handlers when they
   * want to start receive events from given input device.
   */
  int input_open_device(struct input_handle *handle)
  {
  	struct input_dev *dev = handle->dev;
  	int retval;
  
  	retval = mutex_lock_interruptible(&dev->mutex);
  	if (retval)
  		return retval;
  
  	if (dev->going_away) {
  		retval = -ENODEV;
  		goto out;
  	}
  
  	handle->open++;
  
  	if (!dev->users++ && dev->open)
  		retval = dev->open(dev);
  
  	if (retval) {
  		dev->users--;
  		if (!--handle->open) {
  			/*
  			 * Make sure we are not delivering any more events
  			 * through this handle
  			 */
  			synchronize_rcu();
  		}
  	}
  
   out:
  	mutex_unlock(&dev->mutex);
  	return retval;
  }
  EXPORT_SYMBOL(input_open_device);
  
  int input_flush_device(struct input_handle *handle, struct file *file)
  {
  	struct input_dev *dev = handle->dev;
  	int retval;
  
  	retval = mutex_lock_interruptible(&dev->mutex);
  	if (retval)
  		return retval;
  
  	if (dev->flush)
  		retval = dev->flush(dev, file);
  
  	mutex_unlock(&dev->mutex);
  	return retval;
  }
  EXPORT_SYMBOL(input_flush_device);
  
  /**
   * input_close_device - close input device
   * @handle: handle through which device is being accessed
   *
   * This function should be called by input handlers when they
   * want to stop receive events from given input device.
   */
  void input_close_device(struct input_handle *handle)
  {
  	struct input_dev *dev = handle->dev;
  
  	mutex_lock(&dev->mutex);
  
  	__input_release_device(handle);
  
  	if (!--dev->users && dev->close)
  		dev->close(dev);
  
  	if (!--handle->open) {
  		/*
  		 * synchronize_rcu() makes sure that input_pass_event()
  		 * completed and that no more input events are delivered
  		 * through this handle
  		 */
  		synchronize_rcu();
  	}
  
  	mutex_unlock(&dev->mutex);
  }
  EXPORT_SYMBOL(input_close_device);
  
  /*
   * Prepare device for unregistering
   */
  static void input_disconnect_device(struct input_dev *dev)
  {
  	struct input_handle *handle;
  	int code;
  
  	/*
  	 * Mark device as going away. Note that we take dev->mutex here
  	 * not to protect access to dev->going_away but rather to ensure
  	 * that there are no threads in the middle of input_open_device()
  	 */
  	mutex_lock(&dev->mutex);
  	dev->going_away = true;
  	mutex_unlock(&dev->mutex);
  
  	spin_lock_irq(&dev->event_lock);
  
  	/*
  	 * Simulate keyup events for all pressed keys so that handlers
  	 * are not left with "stuck" keys. The driver may continue
  	 * generate events even after we done here but they will not
  	 * reach any handlers.
  	 */
  	if (is_event_supported(EV_KEY, dev->evbit, EV_MAX)) {
  		for (code = 0; code <= KEY_MAX; code++) {
  			if (is_event_supported(code, dev->keybit, KEY_MAX) &&
  			    __test_and_clear_bit(code, dev->key)) {
  				input_pass_event(dev, EV_KEY, code, 0);
  			}
  		}
  		input_pass_event(dev, EV_SYN, SYN_REPORT, 1);
  	}
  
  	list_for_each_entry(handle, &dev->h_list, d_node)
  		handle->open = 0;
  
  	spin_unlock_irq(&dev->event_lock);
  }
  
  static int input_fetch_keycode(struct input_dev *dev, int scancode)
  {
  	switch (dev->keycodesize) {
  		case 1:
  			return ((u8 *)dev->keycode)[scancode];
  
  		case 2:
  			return ((u16 *)dev->keycode)[scancode];
  
  		default:
  			return ((u32 *)dev->keycode)[scancode];
  	}
  }
  
  static int input_default_getkeycode(struct input_dev *dev,
  				    unsigned int scancode,
  				    unsigned int *keycode)
  {
  	if (!dev->keycodesize)
  		return -EINVAL;
  
  	if (scancode >= dev->keycodemax)
  		return -EINVAL;
  
  	*keycode = input_fetch_keycode(dev, scancode);
  
  	return 0;
  }
  
  static int input_default_setkeycode(struct input_dev *dev,
  				    unsigned int scancode,
  				    unsigned int keycode)
  {
  	int old_keycode;
  	int i;
  
  	if (scancode >= dev->keycodemax)
  		return -EINVAL;
  
  	if (!dev->keycodesize)
  		return -EINVAL;
  
  	if (dev->keycodesize < sizeof(keycode) && (keycode >> (dev->keycodesize * 8)))
  		return -EINVAL;
  
  	switch (dev->keycodesize) {
  		case 1: {
  			u8 *k = (u8 *)dev->keycode;
  			old_keycode = k[scancode];
  			k[scancode] = keycode;
  			break;
  		}
  		case 2: {
  			u16 *k = (u16 *)dev->keycode;
  			old_keycode = k[scancode];
  			k[scancode] = keycode;
  			break;
  		}
  		default: {
  			u32 *k = (u32 *)dev->keycode;
  			old_keycode = k[scancode];
  			k[scancode] = keycode;
  			break;
  		}
  	}
  
  	__clear_bit(old_keycode, dev->keybit);
  	__set_bit(keycode, dev->keybit);
  
  	for (i = 0; i < dev->keycodemax; i++) {
  		if (input_fetch_keycode(dev, i) == old_keycode) {
  			__set_bit(old_keycode, dev->keybit);
  			break; /* Setting the bit twice is useless, so break */
  		}
  	}
  
  	return 0;
  }
  
  /**
   * input_get_keycode - retrieve keycode currently mapped to a given scancode
   * @dev: input device which keymap is being queried
   * @scancode: scancode (or its equivalent for device in question) for which
   *	keycode is needed
   * @keycode: result
   *
   * This function should be called by anyone interested in retrieving current
   * keymap. Presently keyboard and evdev handlers use it.
   */
  int input_get_keycode(struct input_dev *dev,
  		      unsigned int scancode, unsigned int *keycode)
  {
  	unsigned long flags;
  	int retval;
  
  	spin_lock_irqsave(&dev->event_lock, flags);
  	retval = dev->getkeycode(dev, scancode, keycode);
  	spin_unlock_irqrestore(&dev->event_lock, flags);
  
  	return retval;
  }
  EXPORT_SYMBOL(input_get_keycode);
  
  /**
   * input_get_keycode - assign new keycode to a given scancode
   * @dev: input device which keymap is being updated
   * @scancode: scancode (or its equivalent for device in question)
   * @keycode: new keycode to be assigned to the scancode
   *
   * This function should be called by anyone needing to update current
   * keymap. Presently keyboard and evdev handlers use it.
   */
  int input_set_keycode(struct input_dev *dev,
  		      unsigned int scancode, unsigned int keycode)
  {
  	unsigned long flags;
  	int old_keycode;
  	int retval;
  
  	if (keycode > KEY_MAX)
  		return -EINVAL;
  
  	spin_lock_irqsave(&dev->event_lock, flags);
  
  	retval = dev->getkeycode(dev, scancode, &old_keycode);
  	if (retval)
  		goto out;
  
  	retval = dev->setkeycode(dev, scancode, keycode);
  	if (retval)
  		goto out;
  
  	/* Make sure KEY_RESERVED did not get enabled. */
  	__clear_bit(KEY_RESERVED, dev->keybit);
  
  	/*
  	 * Simulate keyup event if keycode is not present
  	 * in the keymap anymore
  	 */
  	if (test_bit(EV_KEY, dev->evbit) &&
  	    !is_event_supported(old_keycode, dev->keybit, KEY_MAX) &&
  	    __test_and_clear_bit(old_keycode, dev->key)) {
  
  		input_pass_event(dev, EV_KEY, old_keycode, 0);
  		if (dev->sync)
  			input_pass_event(dev, EV_SYN, SYN_REPORT, 1);
  	}
  
   out:
  	spin_unlock_irqrestore(&dev->event_lock, flags);
  
  	return retval;
  }
  EXPORT_SYMBOL(input_set_keycode);
  
  #define MATCH_BIT(bit, max) \
  		for (i = 0; i < BITS_TO_LONGS(max); i++) \
  			if ((id->bit[i] & dev->bit[i]) != id->bit[i]) \
  				break; \
  		if (i != BITS_TO_LONGS(max)) \
  			continue;
  
  static const struct input_device_id *input_match_device(struct input_handler *handler,
  							struct input_dev *dev)
  {
  	const struct input_device_id *id;
  	int i;
  
  	for (id = handler->id_table; id->flags || id->driver_info; id++) {
  
  		if (id->flags & INPUT_DEVICE_ID_MATCH_BUS)
  			if (id->bustype != dev->id.bustype)
  				continue;
  
  		if (id->flags & INPUT_DEVICE_ID_MATCH_VENDOR)
  			if (id->vendor != dev->id.vendor)
  				continue;
  
  		if (id->flags & INPUT_DEVICE_ID_MATCH_PRODUCT)
  			if (id->product != dev->id.product)
  				continue;
  
  		if (id->flags & INPUT_DEVICE_ID_MATCH_VERSION)
  			if (id->version != dev->id.version)
  				continue;
  
  		MATCH_BIT(evbit,  EV_MAX);
  		MATCH_BIT(keybit, KEY_MAX);
  		MATCH_BIT(relbit, REL_MAX);
  		MATCH_BIT(absbit, ABS_MAX);
  		MATCH_BIT(mscbit, MSC_MAX);
  		MATCH_BIT(ledbit, LED_MAX);
  		MATCH_BIT(sndbit, SND_MAX);
  		MATCH_BIT(ffbit,  FF_MAX);
  		MATCH_BIT(swbit,  SW_MAX);
  
  		if (!handler->match || handler->match(handler, dev))
  			return id;
  	}
  
  	return NULL;
  }
  
  static int input_attach_handler(struct input_dev *dev, struct input_handler *handler)
  {
  	const struct input_device_id *id;
  	int error;
  
  	id = input_match_device(handler, dev);
  	if (!id)
  		return -ENODEV;
  
  	error = handler->connect(handler, dev, id);
  	if (error && error != -ENODEV)
  		printk(KERN_ERR
  			"input: failed to attach handler %s to device %s, "
  			"error: %d\n",
  			handler->name, kobject_name(&dev->dev.kobj), error);
  
  	return error;
  }
  
  #ifdef CONFIG_COMPAT
  
  static int input_bits_to_string(char *buf, int buf_size,
  				unsigned long bits, bool skip_empty)
  {
  	int len = 0;
  
  	if (INPUT_COMPAT_TEST) {
  		u32 dword = bits >> 32;
  		if (dword || !skip_empty)
  			len += snprintf(buf, buf_size, "%x ", dword);
  
  		dword = bits & 0xffffffffUL;
  		if (dword || !skip_empty || len)
  			len += snprintf(buf + len, max(buf_size - len, 0),
  					"%x", dword);
  	} else {
  		if (bits || !skip_empty)
  			len += snprintf(buf, buf_size, "%lx", bits);
  	}
  
  	return len;
  }
  
  #else /* !CONFIG_COMPAT */
  
  static int input_bits_to_string(char *buf, int buf_size,
  				unsigned long bits, bool skip_empty)
  {
  	return bits || !skip_empty ?
  		snprintf(buf, buf_size, "%lx", bits) : 0;
  }
  
  #endif
  
  #ifdef CONFIG_PROC_FS
  
  static struct proc_dir_entry *proc_bus_input_dir;
  static DECLARE_WAIT_QUEUE_HEAD(input_devices_poll_wait);
  static int input_devices_state;
  
  static inline void input_wakeup_procfs_readers(void)
  {
  	input_devices_state++;
  	wake_up(&input_devices_poll_wait);
  }
  
  static unsigned int input_proc_devices_poll(struct file *file, poll_table *wait)
  {
  	poll_wait(file, &input_devices_poll_wait, wait);
  	if (file->f_version != input_devices_state) {
  		file->f_version = input_devices_state;
  		return POLLIN | POLLRDNORM;
  	}
  
  	return 0;
  }
  
  union input_seq_state {
  	struct {
  		unsigned short pos;
  		bool mutex_acquired;
  	};
  	void *p;
  };
  
  static void *input_devices_seq_start(struct seq_file *seq, loff_t *pos)
  {
  	union input_seq_state *state = (union input_seq_state *)&seq->private;
  	int error;
  
  	/* We need to fit into seq->private pointer */
  	BUILD_BUG_ON(sizeof(union input_seq_state) != sizeof(seq->private));
  
  	error = mutex_lock_interruptible(&input_mutex);
  	if (error) {
  		state->mutex_acquired = false;
  		return ERR_PTR(error);
  	}
  
  	state->mutex_acquired = true;
  
  	return seq_list_start(&input_dev_list, *pos);
  }
  
  static void *input_devices_seq_next(struct seq_file *seq, void *v, loff_t *pos)
  {
  	return seq_list_next(v, &input_dev_list, pos);
  }
  
  static void input_seq_stop(struct seq_file *seq, void *v)
  {
  	union input_seq_state *state = (union input_seq_state *)&seq->private;
  
  	if (state->mutex_acquired)
  		mutex_unlock(&input_mutex);
  }
  
  static void input_seq_print_bitmap(struct seq_file *seq, const char *name,
  				   unsigned long *bitmap, int max)
  {
  	int i;
  	bool skip_empty = true;
  	char buf[18];
  
  	seq_printf(seq, "B: %s=", name);
  
  	for (i = BITS_TO_LONGS(max) - 1; i >= 0; i--) {
  		if (input_bits_to_string(buf, sizeof(buf),
  					 bitmap[i], skip_empty)) {
  			skip_empty = false;
  			seq_printf(seq, "%s%s", buf, i > 0 ? " " : "");
  		}
  	}
  
  	/*
  	 * If no output was produced print a single 0.
  	 */
  	if (skip_empty)
  		seq_puts(seq, "0");
  
  	seq_putc(seq, '\n');
  }
  
  static int input_devices_seq_show(struct seq_file *seq, void *v)
  {
  	struct input_dev *dev = container_of(v, struct input_dev, node);
  	const char *path = kobject_get_path(&dev->dev.kobj, GFP_KERNEL);
  	struct input_handle *handle;
  
  	seq_printf(seq, "I: Bus=%04x Vendor=%04x Product=%04x Version=%04x\n",
  		   dev->id.bustype, dev->id.vendor, dev->id.product, dev->id.version);
  
  	seq_printf(seq, "N: Name=\"%s\"\n", dev->name ? dev->name : "");
  	seq_printf(seq, "P: Phys=%s\n", dev->phys ? dev->phys : "");
  	seq_printf(seq, "S: Sysfs=%s\n", path ? path : "");
  	seq_printf(seq, "U: Uniq=%s\n", dev->uniq ? dev->uniq : "");
  	seq_printf(seq, "H: Handlers=");
  
  	list_for_each_entry(handle, &dev->h_list, d_node)
  		seq_printf(seq, "%s ", handle->name);
  	seq_putc(seq, '\n');
  
  	input_seq_print_bitmap(seq, "EV", dev->evbit, EV_MAX);
  	if (test_bit(EV_KEY, dev->evbit))
  		input_seq_print_bitmap(seq, "KEY", dev->keybit, KEY_MAX);
  	if (test_bit(EV_REL, dev->evbit))
  		input_seq_print_bitmap(seq, "REL", dev->relbit, REL_MAX);
  	if (test_bit(EV_ABS, dev->evbit))
  		input_seq_print_bitmap(seq, "ABS", dev->absbit, ABS_MAX);
  	if (test_bit(EV_MSC, dev->evbit))
  		input_seq_print_bitmap(seq, "MSC", dev->mscbit, MSC_MAX);
  	if (test_bit(EV_LED, dev->evbit))
  		input_seq_print_bitmap(seq, "LED", dev->ledbit, LED_MAX);
  	if (test_bit(EV_SND, dev->evbit))
  		input_seq_print_bitmap(seq, "SND", dev->sndbit, SND_MAX);
  	if (test_bit(EV_FF, dev->evbit))
  		input_seq_print_bitmap(seq, "FF", dev->ffbit, FF_MAX);
  	if (test_bit(EV_SW, dev->evbit))
  		input_seq_print_bitmap(seq, "SW", dev->swbit, SW_MAX);
  
  	seq_putc(seq, '\n');
  
  	kfree(path);
  	return 0;
  }
  
  static const struct seq_operations input_devices_seq_ops = {
  	.start	= input_devices_seq_start,
  	.next	= input_devices_seq_next,
  	.stop	= input_seq_stop,
  	.show	= input_devices_seq_show,
  };
  
  static int input_proc_devices_open(struct inode *inode, struct file *file)
  {
  	return seq_open(file, &input_devices_seq_ops);
  }
  
  static const struct file_operations input_devices_fileops = {
  	.owner		= THIS_MODULE,
  	.open		= input_proc_devices_open,
  	.poll		= input_proc_devices_poll,
  	.read		= seq_read,
  	.llseek		= seq_lseek,
  	.release	= seq_release,
  };
  
  static void *input_handlers_seq_start(struct seq_file *seq, loff_t *pos)
  {
  	union input_seq_state *state = (union input_seq_state *)&seq->private;
  	int error;
  
  	/* We need to fit into seq->private pointer */
  	BUILD_BUG_ON(sizeof(union input_seq_state) != sizeof(seq->private));
  
  	error = mutex_lock_interruptible(&input_mutex);
  	if (error) {
  		state->mutex_acquired = false;
  		return ERR_PTR(error);
  	}
  
  	state->mutex_acquired = true;
  	state->pos = *pos;
  
  	return seq_list_start(&input_handler_list, *pos);
  }
  
  static void *input_handlers_seq_next(struct seq_file *seq, void *v, loff_t *pos)
  {
  	union input_seq_state *state = (union input_seq_state *)&seq->private;
  
  	state->pos = *pos + 1;
  	return seq_list_next(v, &input_handler_list, pos);
  }
  
  static int input_handlers_seq_show(struct seq_file *seq, void *v)
  {
  	struct input_handler *handler = container_of(v, struct input_handler, node);
  	union input_seq_state *state = (union input_seq_state *)&seq->private;
  
  	seq_printf(seq, "N: Number=%u Name=%s", state->pos, handler->name);
  	if (handler->filter)
  		seq_puts(seq, " (filter)");
  	if (handler->fops)
  		seq_printf(seq, " Minor=%d", handler->minor);
  	seq_putc(seq, '\n');
  
  	return 0;
  }
  
  static const struct seq_operations input_handlers_seq_ops = {
  	.start	= input_handlers_seq_start,
  	.next	= input_handlers_seq_next,
  	.stop	= input_seq_stop,
  	.show	= input_handlers_seq_show,
  };
  
  static int input_proc_handlers_open(struct inode *inode, struct file *file)
  {
  	return seq_open(file, &input_handlers_seq_ops);
  }
  
  static const struct file_operations input_handlers_fileops = {
  	.owner		= THIS_MODULE,
  	.open		= input_proc_handlers_open,
  	.read		= seq_read,
  	.llseek		= seq_lseek,
  	.release	= seq_release,
  };
  
  static int __init input_proc_init(void)
  {
  	struct proc_dir_entry *entry;
  
  	proc_bus_input_dir = proc_mkdir("bus/input", NULL);
  	if (!proc_bus_input_dir)
  		return -ENOMEM;
  
  	entry = proc_create("devices", 0, proc_bus_input_dir,
  			    &input_devices_fileops);
  	if (!entry)
  		goto fail1;
  
  	entry = proc_create("handlers", 0, proc_bus_input_dir,
  			    &input_handlers_fileops);
  	if (!entry)
  		goto fail2;
  
  	return 0;
  
   fail2:	remove_proc_entry("devices", proc_bus_input_dir);
   fail1: remove_proc_entry("bus/input", NULL);
  	return -ENOMEM;
  }
  
  static void input_proc_exit(void)
  {
  	remove_proc_entry("devices", proc_bus_input_dir);
  	remove_proc_entry("handlers", proc_bus_input_dir);
  	remove_proc_entry("bus/input", NULL);
  }
  
  #else /* !CONFIG_PROC_FS */
  static inline void input_wakeup_procfs_readers(void) { }
  static inline int input_proc_init(void) { return 0; }
  static inline void input_proc_exit(void) { }
  #endif
  
  #define INPUT_DEV_STRING_ATTR_SHOW(name)				\
  static ssize_t input_dev_show_##name(struct device *dev,		\
  				     struct device_attribute *attr,	\
  				     char *buf)				\
  {									\
  	struct input_dev *input_dev = to_input_dev(dev);		\
  									\
  	return scnprintf(buf, PAGE_SIZE, "%s\n",			\
  			 input_dev->name ? input_dev->name : "");	\
  }									\
  static DEVICE_ATTR(name, S_IRUGO, input_dev_show_##name, NULL)
  
  INPUT_DEV_STRING_ATTR_SHOW(name);
  INPUT_DEV_STRING_ATTR_SHOW(phys);
  INPUT_DEV_STRING_ATTR_SHOW(uniq);
  
  static int input_print_modalias_bits(char *buf, int size,
  				     char name, unsigned long *bm,
  				     unsigned int min_bit, unsigned int max_bit)
  {
  	int len = 0, i;
  
  	len += snprintf(buf, max(size, 0), "%c", name);
  	for (i = min_bit; i < max_bit; i++)
  		if (bm[BIT_WORD(i)] & BIT_MASK(i))
  			len += snprintf(buf + len, max(size - len, 0), "%X,", i);
  	return len;
  }
  
  static int input_print_modalias(char *buf, int size, struct input_dev *id,
  				int add_cr)
  {
  	int len;
  
  	len = snprintf(buf, max(size, 0),
  		       "input:b%04Xv%04Xp%04Xe%04X-",
  		       id->id.bustype, id->id.vendor,
  		       id->id.product, id->id.version);
  
  	len += input_print_modalias_bits(buf + len, size - len,
  				'e', id->evbit, 0, EV_MAX);
  	len += input_print_modalias_bits(buf + len, size - len,
  				'k', id->keybit, KEY_MIN_INTERESTING, KEY_MAX);
  	len += input_print_modalias_bits(buf + len, size - len,
  				'r', id->relbit, 0, REL_MAX);
  	len += input_print_modalias_bits(buf + len, size - len,
  				'a', id->absbit, 0, ABS_MAX);
  	len += input_print_modalias_bits(buf + len, size - len,
  				'm', id->mscbit, 0, MSC_MAX);
  	len += input_print_modalias_bits(buf + len, size - len,
  				'l', id->ledbit, 0, LED_MAX);
  	len += input_print_modalias_bits(buf + len, size - len,
  				's', id->sndbit, 0, SND_MAX);
  	len += input_print_modalias_bits(buf + len, size - len,
  				'f', id->ffbit, 0, FF_MAX);
  	len += input_print_modalias_bits(buf + len, size - len,
  				'w', id->swbit, 0, SW_MAX);
  
  	if (add_cr)
  		len += snprintf(buf + len, max(size - len, 0), "\n");
  
  	return len;
  }
  
  static ssize_t input_dev_show_modalias(struct device *dev,
  				       struct device_attribute *attr,
  				       char *buf)
  {
  	struct input_dev *id = to_input_dev(dev);
  	ssize_t len;
  
  	len = input_print_modalias(buf, PAGE_SIZE, id, 1);
  
  	return min_t(int, len, PAGE_SIZE);
  }
  static DEVICE_ATTR(modalias, S_IRUGO, input_dev_show_modalias, NULL);
  
  static struct attribute *input_dev_attrs[] = {
  	&dev_attr_name.attr,
  	&dev_attr_phys.attr,
  	&dev_attr_uniq.attr,
  	&dev_attr_modalias.attr,
  	NULL
  };
  
  static struct attribute_group input_dev_attr_group = {
  	.attrs	= input_dev_attrs,
  };
  
  #define INPUT_DEV_ID_ATTR(name)						\
  static ssize_t input_dev_show_id_##name(struct device *dev,		\
  					struct device_attribute *attr,	\
  					char *buf)			\
  {									\
  	struct input_dev *input_dev = to_input_dev(dev);		\
  	return scnprintf(buf, PAGE_SIZE, "%04x\n", input_dev->id.name);	\
  }									\
  static DEVICE_ATTR(name, S_IRUGO, input_dev_show_id_##name, NULL)
  
  INPUT_DEV_ID_ATTR(bustype);
  INPUT_DEV_ID_ATTR(vendor);
  INPUT_DEV_ID_ATTR(product);
  INPUT_DEV_ID_ATTR(version);
  
  static struct attribute *input_dev_id_attrs[] = {
  	&dev_attr_bustype.attr,
  	&dev_attr_vendor.attr,
  	&dev_attr_product.attr,
  	&dev_attr_version.attr,
  	NULL
  };
  
  static struct attribute_group input_dev_id_attr_group = {
  	.name	= "id",
  	.attrs	= input_dev_id_attrs,
  };
  
  static int input_print_bitmap(char *buf, int buf_size, unsigned long *bitmap,
  			      int max, int add_cr)
  {
  	int i;
  	int len = 0;
  	bool skip_empty = true;
  
  	for (i = BITS_TO_LONGS(max) - 1; i >= 0; i--) {
  		len += input_bits_to_string(buf + len, max(buf_size - len, 0),
  					    bitmap[i], skip_empty);
  		if (len) {
  			skip_empty = false;
  			if (i > 0)
  				len += snprintf(buf + len, max(buf_size - len, 0), " ");
  		}
  	}
  
  	/*
  	 * If no output was produced print a single 0.
  	 */
  	if (len == 0)
  		len = snprintf(buf, buf_size, "%d", 0);
  
  	if (add_cr)
  		len += snprintf(buf + len, max(buf_size - len, 0), "\n");
  
  	return len;
  }
  
  #define INPUT_DEV_CAP_ATTR(ev, bm)					\
  static ssize_t input_dev_show_cap_##bm(struct device *dev,		\
  				       struct device_attribute *attr,	\
  				       char *buf)			\
  {									\
  	struct input_dev *input_dev = to_input_dev(dev);		\
  	int len = input_print_bitmap(buf, PAGE_SIZE,			\
  				     input_dev->bm##bit, ev##_MAX,	\
  				     true);				\
  	return min_t(int, len, PAGE_SIZE);				\
  }									\
  static DEVICE_ATTR(bm, S_IRUGO, input_dev_show_cap_##bm, NULL)
  
  INPUT_DEV_CAP_ATTR(EV, ev);
  INPUT_DEV_CAP_ATTR(KEY, key);
  INPUT_DEV_CAP_ATTR(REL, rel);
  INPUT_DEV_CAP_ATTR(ABS, abs);
  INPUT_DEV_CAP_ATTR(MSC, msc);
  INPUT_DEV_CAP_ATTR(LED, led);
  INPUT_DEV_CAP_ATTR(SND, snd);
  INPUT_DEV_CAP_ATTR(FF, ff);
  INPUT_DEV_CAP_ATTR(SW, sw);
  
  static struct attribute *input_dev_caps_attrs[] = {
  	&dev_attr_ev.attr,
  	&dev_attr_key.attr,
  	&dev_attr_rel.attr,
  	&dev_attr_abs.attr,
  	&dev_attr_msc.attr,
  	&dev_attr_led.attr,
  	&dev_attr_snd.attr,
  	&dev_attr_ff.attr,
  	&dev_attr_sw.attr,
  	NULL
  };
  
  static struct attribute_group input_dev_caps_attr_group = {
  	.name	= "capabilities",
  	.attrs	= input_dev_caps_attrs,
  };
  
  static const struct attribute_group *input_dev_attr_groups[] = {
  	&input_dev_attr_group,
  	&input_dev_id_attr_group,
  	&input_dev_caps_attr_group,
  	NULL
  };
  
  static void input_dev_release(struct device *device)
  {
  	struct input_dev *dev = to_input_dev(device);
  
  	input_ff_destroy(dev);
  	kfree(dev);
  
  	module_put(THIS_MODULE);
  }
  
  /*
   * Input uevent interface - loading event handlers based on
   * device bitfields.
   */
  static int input_add_uevent_bm_var(struct kobj_uevent_env *env,
  				   const char *name, unsigned long *bitmap, int max)
  {
  	int len;
  
  	if (add_uevent_var(env, "%s=", name))
  		return -ENOMEM;
  
  	len = input_print_bitmap(&env->buf[env->buflen - 1],
  				 sizeof(env->buf) - env->buflen,
  				 bitmap, max, false);
  	if (len >= (sizeof(env->buf) - env->buflen))
  		return -ENOMEM;
  
  	env->buflen += len;
  	return 0;
  }
  
  static int input_add_uevent_modalias_var(struct kobj_uevent_env *env,
  					 struct input_dev *dev)
  {
  	int len;
  
  	if (add_uevent_var(env, "MODALIAS="))
  		return -ENOMEM;
  
  	len = input_print_modalias(&env->buf[env->buflen - 1],
  				   sizeof(env->buf) - env->buflen,
  				   dev, 0);
  	if (len >= (sizeof(env->buf) - env->buflen))
  		return -ENOMEM;
  
  	env->buflen += len;
  	return 0;
  }
  
  #define INPUT_ADD_HOTPLUG_VAR(fmt, val...)				\
  	do {								\
  		int err = add_uevent_var(env, fmt, val);		\
  		if (err)						\
  			return err;					\
  	} while (0)
  
  #define INPUT_ADD_HOTPLUG_BM_VAR(name, bm, max)				\
  	do {								\
  		int err = input_add_uevent_bm_var(env, name, bm, max);	\
  		if (err)						\
  			return err;					\
  	} while (0)
  
  #define INPUT_ADD_HOTPLUG_MODALIAS_VAR(dev)				\
  	do {								\
  		int err = input_add_uevent_modalias_var(env, dev);	\
  		if (err)						\
  			return err;					\
  	} while (0)
  
  static int input_dev_uevent(struct device *device, struct kobj_uevent_env *env)
  {
  	struct input_dev *dev = to_input_dev(device);
  
  	INPUT_ADD_HOTPLUG_VAR("PRODUCT=%x/%x/%x/%x",
  				dev->id.bustype, dev->id.vendor,
  				dev->id.product, dev->id.version);
  	if (dev->name)
  		INPUT_ADD_HOTPLUG_VAR("NAME=\"%s\"", dev->name);
  	if (dev->phys)
  		INPUT_ADD_HOTPLUG_VAR("PHYS=\"%s\"", dev->phys);
  	if (dev->uniq)
  		INPUT_ADD_HOTPLUG_VAR("UNIQ=\"%s\"", dev->uniq);
  
  	INPUT_ADD_HOTPLUG_BM_VAR("EV=", dev->evbit, EV_MAX);
  	if (test_bit(EV_KEY, dev->evbit))
  		INPUT_ADD_HOTPLUG_BM_VAR("KEY=", dev->keybit, KEY_MAX);
  	if (test_bit(EV_REL, dev->evbit))
  		INPUT_ADD_HOTPLUG_BM_VAR("REL=", dev->relbit, REL_MAX);
  	if (test_bit(EV_ABS, dev->evbit))
  		INPUT_ADD_HOTPLUG_BM_VAR("ABS=", dev->absbit, ABS_MAX);
  	if (test_bit(EV_MSC, dev->evbit))
  		INPUT_ADD_HOTPLUG_BM_VAR("MSC=", dev->mscbit, MSC_MAX);
  	if (test_bit(EV_LED, dev->evbit))
  		INPUT_ADD_HOTPLUG_BM_VAR("LED=", dev->ledbit, LED_MAX);
  	if (test_bit(EV_SND, dev->evbit))
  		INPUT_ADD_HOTPLUG_BM_VAR("SND=", dev->sndbit, SND_MAX);
  	if (test_bit(EV_FF, dev->evbit))
  		INPUT_ADD_HOTPLUG_BM_VAR("FF=", dev->ffbit, FF_MAX);
  	if (test_bit(EV_SW, dev->evbit))
  		INPUT_ADD_HOTPLUG_BM_VAR("SW=", dev->swbit, SW_MAX);
  
  	INPUT_ADD_HOTPLUG_MODALIAS_VAR(dev);
  
  	return 0;
  }
  
  #define INPUT_DO_TOGGLE(dev, type, bits, on)				\
  	do {								\
  		int i;							\
  		bool active;						\
  									\
  		if (!test_bit(EV_##type, dev->evbit))			\
  			break;						\
  									\
  		for (i = 0; i < type##_MAX; i++) {			\
  			if (!test_bit(i, dev->bits##bit))		\
  				continue;				\
  									\
  			active = test_bit(i, dev->bits);		\
  			if (!active && !on)				\
  				continue;				\
  									\
  			dev->event(dev, EV_##type, i, on ? active : 0);	\
  		}							\
  	} while (0)
  
  #ifdef CONFIG_PM
  static void input_dev_reset(struct input_dev *dev, bool activate)
  {
  	if (!dev->event)
  		return;
  
  	INPUT_DO_TOGGLE(dev, LED, led, activate);
  	INPUT_DO_TOGGLE(dev, SND, snd, activate);
  
  	if (activate && test_bit(EV_REP, dev->evbit)) {
  		dev->event(dev, EV_REP, REP_PERIOD, dev->rep[REP_PERIOD]);
  		dev->event(dev, EV_REP, REP_DELAY, dev->rep[REP_DELAY]);
  	}
  }
  
  static int input_dev_suspend(struct device *dev)
  {
  	struct input_dev *input_dev = to_input_dev(dev);
  
  	mutex_lock(&input_dev->mutex);
  	input_dev_reset(input_dev, false);
  	mutex_unlock(&input_dev->mutex);
  
  	return 0;
  }
  
  static int input_dev_resume(struct device *dev)
  {
  	struct input_dev *input_dev = to_input_dev(dev);
  
  	mutex_lock(&input_dev->mutex);
  	input_dev_reset(input_dev, true);
  	mutex_unlock(&input_dev->mutex);
  
  	return 0;
  }
  
  static const struct dev_pm_ops input_dev_pm_ops = {
  	.suspend	= input_dev_suspend,
  	.resume		= input_dev_resume,
  	.poweroff	= input_dev_suspend,
  	.restore	= input_dev_resume,
  };
  #endif /* CONFIG_PM */
  
  static struct device_type input_dev_type = {
  	.groups		= input_dev_attr_groups,
  	.release	= input_dev_release,
  	.uevent		= input_dev_uevent,
  #ifdef CONFIG_PM
  	.pm		= &input_dev_pm_ops,
  #endif
  };
  
  static char *input_devnode(struct device *dev, mode_t *mode)
  {
  	return kasprintf(GFP_KERNEL, "input/%s", dev_name(dev));
  }
  
  struct class input_class = {
  	.name		= "input",
  	.devnode	= input_devnode,
  };
  EXPORT_SYMBOL_GPL(input_class);
  
  /**
   * input_allocate_device - allocate memory for new input device
   *
   * Returns prepared struct input_dev or NULL.
   *
   * NOTE: Use input_free_device() to free devices that have not been
   * registered; input_unregister_device() should be used for already
   * registered devices.
   */
  struct input_dev *input_allocate_device(void)
  {
  	struct input_dev *dev;
  
  	dev = kzalloc(sizeof(struct input_dev), GFP_KERNEL);
  	if (dev) {
  		dev->dev.type = &input_dev_type;
  		dev->dev.class = &input_class;
  		device_initialize(&dev->dev);
  		mutex_init(&dev->mutex);
  		spin_lock_init(&dev->event_lock);
  		INIT_LIST_HEAD(&dev->h_list);
  		INIT_LIST_HEAD(&dev->node);
  
  		__module_get(THIS_MODULE);
  	}
  
  	return dev;
  }
  EXPORT_SYMBOL(input_allocate_device);
  
  /**
   * input_free_device - free memory occupied by input_dev structure
   * @dev: input device to free
   *
   * This function should only be used if input_register_device()
   * was not called yet or if it failed. Once device was registered
   * use input_unregister_device() and memory will be freed once last
   * reference to the device is dropped.
   *
   * Device should be allocated by input_allocate_device().
   *
   * NOTE: If there are references to the input device then memory
   * will not be freed until last reference is dropped.
   */
  void input_free_device(struct input_dev *dev)
  {
  	if (dev)
  		input_put_device(dev);
  }
  EXPORT_SYMBOL(input_free_device);
  
  /**
   * input_set_capability - mark device as capable of a certain event
   * @dev: device that is capable of emitting or accepting event
   * @type: type of the event (EV_KEY, EV_REL, etc...)
   * @code: event code
   *
   * In addition to setting up corresponding bit in appropriate capability
   * bitmap the function also adjusts dev->evbit.
   */
  void input_set_capability(struct input_dev *dev, unsigned int type, unsigned int code)
  {
  	switch (type) {
  	case EV_KEY:
  		__set_bit(code, dev->keybit);
  		break;
  
  	case EV_REL:
  		__set_bit(code, dev->relbit);
  		break;
  
  	case EV_ABS:
  		__set_bit(code, dev->absbit);
  		break;
  
  	case EV_MSC:
  		__set_bit(code, dev->mscbit);
  		break;
  
  	case EV_SW:
  		__set_bit(code, dev->swbit);
  		break;
  
  	case EV_LED:
  		__set_bit(code, dev->ledbit);
  		break;
  
  	case EV_SND:
  		__set_bit(code, dev->sndbit);
  		break;
  
  	case EV_FF:
  		__set_bit(code, dev->ffbit);
  		break;
  
  	case EV_PWR:
  		/* do nothing */
  		break;
  
  	default:
  		printk(KERN_ERR
  			"input_set_capability: unknown type %u (code %u)\n",
  			type, code);
  		dump_stack();
  		return;
  	}
  
  	__set_bit(type, dev->evbit);
  }
  EXPORT_SYMBOL(input_set_capability);
  
  #define INPUT_CLEANSE_BITMASK(dev, type, bits)				\
  	do {								\
  		if (!test_bit(EV_##type, dev->evbit))			\
  			memset(dev->bits##bit, 0,			\
  				sizeof(dev->bits##bit));		\
  	} while (0)
  
  static void input_cleanse_bitmasks(struct input_dev *dev)
  {
  	INPUT_CLEANSE_BITMASK(dev, KEY, key);
  	INPUT_CLEANSE_BITMASK(dev, REL, rel);
  	INPUT_CLEANSE_BITMASK(dev, ABS, abs);
  	INPUT_CLEANSE_BITMASK(dev, MSC, msc);
  	INPUT_CLEANSE_BITMASK(dev, LED, led);
  	INPUT_CLEANSE_BITMASK(dev, SND, snd);
  	INPUT_CLEANSE_BITMASK(dev, FF, ff);
  	INPUT_CLEANSE_BITMASK(dev, SW, sw);
  }
  
  /**
   * input_register_device - register device with input core
   * @dev: device to be registered
   *
   * This function registers device with input core. The device must be
   * allocated with input_allocate_device() and all it's capabilities
   * set up before registering.
   * If function fails the device must be freed with input_free_device().
   * Once device has been successfully registered it can be unregistered
   * with input_unregister_device(); input_free_device() should not be
   * called in this case.
   */
  int input_register_device(struct input_dev *dev)
  {
  	static atomic_t input_no = ATOMIC_INIT(0);
  	struct input_handler *handler;
  	const char *path;
  	int error;
  
  	/* Every input device generates EV_SYN/SYN_REPORT events. */
  	__set_bit(EV_SYN, dev->evbit);
  
  	/* KEY_RESERVED is not supposed to be transmitted to userspace. */
  	__clear_bit(KEY_RESERVED, dev->keybit);
  
  	/* Make sure that bitmasks not mentioned in dev->evbit are clean. */
  	input_cleanse_bitmasks(dev);
  
  	/*
  	 * If delay and period are pre-set by the driver, then autorepeating
  	 * is handled by the driver itself and we don't do it in input.c.
  	 */
  	init_timer(&dev->timer);
  	if (!dev->rep[REP_DELAY] && !dev->rep[REP_PERIOD]) {
  		dev->timer.data = (long) dev;
  		dev->timer.function = input_repeat_key;
  		dev->rep[REP_DELAY] = 250;
  		dev->rep[REP_PERIOD] = 33;
  	}
  
  	if (!dev->getkeycode)
  		dev->getkeycode = input_default_getkeycode;
  
  	if (!dev->setkeycode)
  		dev->setkeycode = input_default_setkeycode;
  
  	dev_set_name(&dev->dev, "input%ld",
  		     (unsigned long) atomic_inc_return(&input_no) - 1);
  
  	error = device_add(&dev->dev);
  	if (error)
  		return error;
  
  	path = kobject_get_path(&dev->dev.kobj, GFP_KERNEL);
  	printk(KERN_INFO "input: %s as %s\n",
  		dev->name ? dev->name : "Unspecified device", path ? path : "N/A");
  	kfree(path);
  
  	error = mutex_lock_interruptible(&input_mutex);
  	if (error) {
  		device_del(&dev->dev);
  		return error;
  	}
  
  	list_add_tail(&dev->node, &input_dev_list);
  
  	list_for_each_entry(handler, &input_handler_list, node)
  		input_attach_handler(dev, handler);
  
  	input_wakeup_procfs_readers();
  
  	mutex_unlock(&input_mutex);
  
  	return 0;
  }
  EXPORT_SYMBOL(input_register_device);
  
  /**
   * input_unregister_device - unregister previously registered device
   * @dev: device to be unregistered
   *
   * This function unregisters an input device. Once device is unregistered
   * the caller should not try to access it as it may get freed at any moment.
   */
  void input_unregister_device(struct input_dev *dev)
  {
  	struct input_handle *handle, *next;
  
  	input_disconnect_device(dev);
  
  	mutex_lock(&input_mutex);
  
  	list_for_each_entry_safe(handle, next, &dev->h_list, d_node)
  		handle->handler->disconnect(handle);
  	WARN_ON(!list_empty(&dev->h_list));
  
  	del_timer_sync(&dev->timer);
  	list_del_init(&dev->node);
  
  	input_wakeup_procfs_readers();
  
  	mutex_unlock(&input_mutex);
  
  	device_unregister(&dev->dev);
  }
  EXPORT_SYMBOL(input_unregister_device);
  
  /**
   * input_register_handler - register a new input handler
   * @handler: handler to be registered
   *
   * This function registers a new input handler (interface) for input
   * devices in the system and attaches it to all input devices that
   * are compatible with the handler.
   */
  int input_register_handler(struct input_handler *handler)
  {
  	struct input_dev *dev;
  	int retval;
  
  	retval = mutex_lock_interruptible(&input_mutex);
  	if (retval)
  		return retval;
  
  	INIT_LIST_HEAD(&handler->h_list);
  
  	if (handler->fops != NULL) {
  		if (input_table[handler->minor >> 5]) {
  			retval = -EBUSY;
  			goto out;
  		}
  		input_table[handler->minor >> 5] = handler;
  	}
  
  	list_add_tail(&handler->node, &input_handler_list);
  
  	list_for_each_entry(dev, &input_dev_list, node)
  		input_attach_handler(dev, handler);
  
  	input_wakeup_procfs_readers();
  
   out:
  	mutex_unlock(&input_mutex);
  	return retval;
  }
  EXPORT_SYMBOL(input_register_handler);
  
  /**
   * input_unregister_handler - unregisters an input handler
   * @handler: handler to be unregistered
   *
   * This function disconnects a handler from its input devices and
   * removes it from lists of known handlers.
   */
  void input_unregister_handler(struct input_handler *handler)
  {
  	struct input_handle *handle, *next;
  
  	mutex_lock(&input_mutex);
  
  	list_for_each_entry_safe(handle, next, &handler->h_list, h_node)
  		handler->disconnect(handle);
  	WARN_ON(!list_empty(&handler->h_list));
  
  	list_del_init(&handler->node);
  
  	if (handler->fops != NULL)
  		input_table[handler->minor >> 5] = NULL;
  
  	input_wakeup_procfs_readers();
  
  	mutex_unlock(&input_mutex);
  }
  EXPORT_SYMBOL(input_unregister_handler);
  
  /**
   * input_handler_for_each_handle - handle iterator
   * @handler: input handler to iterate
   * @data: data for the callback
   * @fn: function to be called for each handle
   *
   * Iterate over @bus's list of devices, and call @fn for each, passing
   * it @data and stop when @fn returns a non-zero value. The function is
   * using RCU to traverse the list and therefore may be usind in atonic
   * contexts. The @fn callback is invoked from RCU critical section and
   * thus must not sleep.
   */
  int input_handler_for_each_handle(struct input_handler *handler, void *data,
  				  int (*fn)(struct input_handle *, void *))
  {
  	struct input_handle *handle;
  	int retval = 0;
  
  	rcu_read_lock();
  
  	list_for_each_entry_rcu(handle, &handler->h_list, h_node) {
  		retval = fn(handle, data);
  		if (retval)
  			break;
  	}
  
  	rcu_read_unlock();
  
  	return retval;
  }
  EXPORT_SYMBOL(input_handler_for_each_handle);
  
  /**
   * input_register_handle - register a new input handle
   * @handle: handle to register
   *
   * This function puts a new input handle onto device's
   * and handler's lists so that events can flow through
   * it once it is opened using input_open_device().
   *
   * This function is supposed to be called from handler's
   * connect() method.
   */
  int input_register_handle(struct input_handle *handle)
  {
  	struct input_handler *handler = handle->handler;
  	struct input_dev *dev = handle->dev;
  	int error;
  
  	/*
  	 * We take dev->mutex here to prevent race with
  	 * input_release_device().
  	 */
  	error = mutex_lock_interruptible(&dev->mutex);
  	if (error)
  		return error;
  
  	/*
  	 * Filters go to the head of the list, normal handlers
  	 * to the tail.
  	 */
  	if (handler->filter)
  		list_add_rcu(&handle->d_node, &dev->h_list);
  	else
  		list_add_tail_rcu(&handle->d_node, &dev->h_list);
  
  	mutex_unlock(&dev->mutex);
  
  	/*
  	 * Since we are supposed to be called from ->connect()
  	 * which is mutually exclusive with ->disconnect()
  	 * we can't be racing with input_unregister_handle()
  	 * and so separate lock is not needed here.
  	 */
  	list_add_tail_rcu(&handle->h_node, &handler->h_list);
  
  	if (handler->start)
  		handler->start(handle);
  
  	return 0;
  }
  EXPORT_SYMBOL(input_register_handle);
  
  /**
   * input_unregister_handle - unregister an input handle
   * @handle: handle to unregister
   *
   * This function removes input handle from device's
   * and handler's lists.
   *
   * This function is supposed to be called from handler's
   * disconnect() method.
   */
  void input_unregister_handle(struct input_handle *handle)
  {
  	struct input_dev *dev = handle->dev;
  
  	list_del_rcu(&handle->h_node);
  
  	/*
  	 * Take dev->mutex to prevent race with input_release_device().
  	 */
  	mutex_lock(&dev->mutex);
  	list_del_rcu(&handle->d_node);
  	mutex_unlock(&dev->mutex);
  
  	synchronize_rcu();
  }
  EXPORT_SYMBOL(input_unregister_handle);
  
  static int input_open_file(struct inode *inode, struct file *file)
  {
  	struct input_handler *handler;
  	const struct file_operations *old_fops, *new_fops = NULL;
  	int err;
  
  	err = mutex_lock_interruptible(&input_mutex);
  	if (err)
  		return err;
  
  	/* No load-on-demand here? */
  	handler = input_table[iminor(inode) >> 5];
  	if (handler)
  		new_fops = fops_get(handler->fops);
  
  	mutex_unlock(&input_mutex);
  
  	/*
  	 * That's _really_ odd. Usually NULL ->open means "nothing special",
  	 * not "no device". Oh, well...
  	 */
  	if (!new_fops || !new_fops->open) {
  		fops_put(new_fops);
  		err = -ENODEV;
  		goto out;
  	}
  
  	old_fops = file->f_op;
  	file->f_op = new_fops;
  
  	err = new_fops->open(inode, file);
  	if (err) {
  		fops_put(file->f_op);
  		file->f_op = fops_get(old_fops);
  	}
  	fops_put(old_fops);
  out:
  	return err;
  }
  
  static const struct file_operations input_fops = {
  	.owner = THIS_MODULE,
  	.open = input_open_file,
  };
  
  static void __init input_init_abs_bypass(void)
  {
  	const unsigned int *p;
  
  	for (p = input_abs_bypass_init_data; *p; p++)
  		input_abs_bypass[BIT_WORD(*p)] |= BIT_MASK(*p);
  }
  
  static int __init input_init(void)
  {
  	int err;
  
  	input_init_abs_bypass();
  
  	err = class_register(&input_class);
  	if (err) {
  		printk(KERN_ERR "input: unable to register input_dev class\n");
  		return err;
  	}
  
  	err = input_proc_init();
  	if (err)
  		goto fail1;
  
  	err = register_chrdev(INPUT_MAJOR, "input", &input_fops);
  	if (err) {
  		printk(KERN_ERR "input: unable to register char major %d", INPUT_MAJOR);
  		goto fail2;
  	}
  
  	return 0;
  
   fail2:	input_proc_exit();
   fail1:	class_unregister(&input_class);
  	return err;
  }
  
  static void __exit input_exit(void)
  {
  	input_proc_exit();
  	unregister_chrdev(INPUT_MAJOR, "input");
  	class_unregister(&input_class);
  }
  
  subsys_initcall(input_init);
  module_exit(input_exit);
  