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input.c

/*
 * 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/input.h>
#include <linux/module.h>
#include <linux/random.h>
#include <linux/major.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/poll.h>
#include <linux/device.h>
#include <linux/mutex.h>
#include <linux/rcupdate.h>

MODULE_AUTHOR("Vojtech Pavlik <vojtech@suse.cz>");
MODULE_DESCRIPTION("Input core");
MODULE_LICENSE("GPL");

#define INPUT_DEVICES   256

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];

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 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_handle *handle;

      rcu_read_lock();

      handle = rcu_dereference(dev->grab);
      if (handle)
            handle->handler->event(handle, type, code, value);
      else
            list_for_each_entry_rcu(handle, &dev->h_list, d_node)
                  if (handle->open)
                        handle->handler->event(handle,
                                          type, code, value);
      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]));
      }
}

#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;
            }
            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);
                  }

                  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)) {

                  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 (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. See also input_inject_event().
 */

void input_event(struct input_dev *dev,
             unsigned int type, unsigned int code, int value)
{
      unsigned long flags;

      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 = 1;
      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_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,
                            int scancode, int *keycode)
{
      if (!dev->keycodesize)
            return -EINVAL;

      if (scancode < 0 || scancode >= dev->keycodemax)
            return -EINVAL;

      *keycode = input_fetch_keycode(dev, scancode);

      return 0;
}

static int input_default_setkeycode(struct input_dev *dev,
                            int scancode, int keycode)
{
      int old_keycode;
      int i;

      if (scancode < 0 || scancode >= dev->keycodemax)
            return -EINVAL;

      if (keycode < 0 || keycode > KEY_MAX)
            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;
}


#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(const struct input_device_id *id,
                                          struct input_dev *dev)
{
      int i;

      for (; 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);

            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;

      if (handler->blacklist && input_match_device(handler->blacklist, dev))
            return -ENODEV;

      id = input_match_device(handler->id_table, 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_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)
{
      int state = input_devices_state;

      poll_wait(file, &input_devices_poll_wait, wait);
      if (state != input_devices_state)
            return POLLIN | POLLRDNORM;

      return 0;
}

static void *input_devices_seq_start(struct seq_file *seq, loff_t *pos)
{
      if (mutex_lock_interruptible(&input_mutex))
            return NULL;

      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_devices_seq_stop(struct seq_file *seq, void *v)
{
      mutex_unlock(&input_mutex);
}

static void input_seq_print_bitmap(struct seq_file *seq, const char *name,
                           unsigned long *bitmap, int max)
{
      int i;

      for (i = BITS_TO_LONGS(max) - 1; i > 0; i--)
            if (bitmap[i])
                  break;

      seq_printf(seq, "B: %s=", name);
      for (; i >= 0; i--)
            seq_printf(seq, "%lx%s", bitmap[i], i > 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 struct seq_operations input_devices_seq_ops = {
      .start      = input_devices_seq_start,
      .next = input_devices_seq_next,
      .stop = input_devices_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)
{
      if (mutex_lock_interruptible(&input_mutex))
            return NULL;

      seq->private = (void *)(unsigned long)*pos;
      return seq_list_start(&input_handler_list, *pos);
}

static void *input_handlers_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
      seq->private = (void *)(unsigned long)(*pos + 1);
      return seq_list_next(v, &input_handler_list, pos);
}

static void input_handlers_seq_stop(struct seq_file *seq, void *v)
{
      mutex_unlock(&input_mutex);
}

static int input_handlers_seq_show(struct seq_file *seq, void *v)
{
      struct input_handler *handler = container_of(v, struct input_handler, node);

      seq_printf(seq, "N: Number=%ld Name=%s",
               (unsigned long)seq->private, handler->name);
      if (handler->fops)
            seq_printf(seq, " Minor=%d", handler->minor);
      seq_putc(seq, '\n');

      return 0;
}
static struct seq_operations input_handlers_seq_ops = {
      .start      = input_handlers_seq_start,
      .next = input_handlers_seq_next,
      .stop = input_handlers_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("input", proc_bus);
      if (!proc_bus_input_dir)
            return -ENOMEM;

      proc_bus_input_dir->owner = THIS_MODULE;

      entry = create_proc_entry("devices", 0, proc_bus_input_dir);
      if (!entry)
            goto fail1;

      entry->owner = THIS_MODULE;
      entry->proc_fops = &input_devices_fileops;

      entry = create_proc_entry("handlers", 0, proc_bus_input_dir);
      if (!entry)
            goto fail2;

      entry->owner = THIS_MODULE;
      entry->proc_fops = &input_handlers_fileops;

      return 0;

 fail2:     remove_proc_entry("devices", proc_bus_input_dir);
 fail1: remove_proc_entry("input", proc_bus);
      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("input", proc_bus);
}

#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;

      for (i = BITS_TO_LONGS(max) - 1; i > 0; i--)
            if (bitmap[i])
                  break;

      for (; i >= 0; i--)
            len += snprintf(buf + len, max(buf_size - len, 0),
                        "%lx%s", bitmap[i], i > 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, 1);    \
      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 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, 0);
      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;
}

static struct device_type input_dev_type = {
      .groups           = input_dev_attr_groups,
      .release    = input_dev_release,
      .uevent           = input_dev_uevent,
};

struct class input_class = {
      .name       = "input",
};
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);

/**
 * 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;

      __set_bit(EV_SYN, dev->evbit);

      /*
       * 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;

      snprintf(dev->dev.bus_id, sizeof(dev->dev.bus_id),
             "input%ld", (unsigned long) atomic_inc_return(&input_no) - 1);

      if (dev->cdev.dev)
            dev->dev.parent = dev->cdev.dev;

      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_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;
      list_add_tail_rcu(&handle->d_node, &dev->h_list);
      mutex_unlock(&dev->mutex);
      synchronize_rcu();

      /*
       * 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(&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_init(&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 = input_table[iminor(inode) >> 5];
      const struct file_operations *old_fops, *new_fops = NULL;
      int err;

      /* No load-on-demand here? */
      if (!handler || !(new_fops = fops_get(handler->fops)))
            return -ENODEV;

      /*
       * That's _really_ odd. Usually NULL ->open means "nothing special",
       * not "no device". Oh, well...
       */
      if (!new_fops->open) {
            fops_put(new_fops);
            return -ENODEV;
      }
      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);
      return err;
}

static const struct file_operations input_fops = {
      .owner = THIS_MODULE,
      .open = input_open_file,
};

static int __init input_init(void)
{
      int err;

      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);

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