drivers/input/evdev.c - kernel/msm-4.19 - Gitiles

 /*
  * Event char devices, giving access to raw input device events.
  *
  * 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.
  */

 #define EVDEV_MINOR_BASE	64
 #define EVDEV_MINORS		32
 #define EVDEV_BUFFER_SIZE	64

 #include <linux/poll.h>
 #include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/input.h>
 #include <linux/major.h>
 #include <linux/device.h>
 #include "input-compat.h"

 struct evdev {
 	int exist;
 	int open;
 	int minor;
 	struct input_handle handle;
 	wait_queue_head_t wait;
 	struct evdev_client *grab;
 	struct list_head client_list;
 	spinlock_t client_lock; /* protects client_list */
 	struct mutex mutex;
 	struct device dev;
 };

 struct evdev_client {
 	struct input_event buffer[EVDEV_BUFFER_SIZE];
 	int head;
 	int tail;
 	spinlock_t buffer_lock; /* protects access to buffer, head and tail */
 	struct fasync_struct *fasync;
 	struct evdev *evdev;
 	struct list_head node;
 };

 static struct evdev *evdev_table[EVDEV_MINORS];
 static DEFINE_MUTEX(evdev_table_mutex);

 static void evdev_pass_event(struct evdev_client *client,
 			     struct input_event *event)
 {
 	/*
 	 * Interrupts are disabled, just acquire the lock
 	 */
 	spin_lock(&client->buffer_lock);
 	client->buffer[client->head++] = *event;
 	client->head &= EVDEV_BUFFER_SIZE - 1;
 	spin_unlock(&client->buffer_lock);

 	if (event->type == EV_SYN)
 		kill_fasync(&client->fasync, SIGIO, POLL_IN);
 }

 /*
  * Pass incoming event to all connected clients.
  */
 static void evdev_event(struct input_handle *handle,
 			unsigned int type, unsigned int code, int value)
 {
 	struct evdev *evdev = handle->private;
 	struct evdev_client *client;
 	struct input_event event;

 	do_gettimeofday(&event.time);
 	event.type = type;
 	event.code = code;
 	event.value = value;

 	rcu_read_lock();

 	client = rcu_dereference(evdev->grab);
 	if (client)
 		evdev_pass_event(client, &event);
 	else
 		list_for_each_entry_rcu(client, &evdev->client_list, node)
 			evdev_pass_event(client, &event);

 	rcu_read_unlock();

 	wake_up_interruptible(&evdev->wait);
 }

 static int evdev_fasync(int fd, struct file *file, int on)
 {
 	struct evdev_client *client = file->private_data;

 	return fasync_helper(fd, file, on, &client->fasync);
 }

 static int evdev_flush(struct file *file, fl_owner_t id)
 {
 	struct evdev_client *client = file->private_data;
 	struct evdev *evdev = client->evdev;
 	int retval;

 	retval = mutex_lock_interruptible(&evdev->mutex);
 	if (retval)
 		return retval;

 	if (!evdev->exist)
 		retval = -ENODEV;
 	else
 		retval = input_flush_device(&evdev->handle, file);

 	mutex_unlock(&evdev->mutex);
 	return retval;
 }

 static void evdev_free(struct device *dev)
 {
 	struct evdev *evdev = container_of(dev, struct evdev, dev);

 	input_put_device(evdev->handle.dev);
 	kfree(evdev);
 }

 /*
  * Grabs an event device (along with underlying input device).
  * This function is called with evdev->mutex taken.
  */
 static int evdev_grab(struct evdev *evdev, struct evdev_client *client)
 {
 	int error;

 	if (evdev->grab)
 		return -EBUSY;

 	error = input_grab_device(&evdev->handle);
 	if (error)
 		return error;

 	rcu_assign_pointer(evdev->grab, client);
 	synchronize_rcu();

 	return 0;
 }

 static int evdev_ungrab(struct evdev *evdev, struct evdev_client *client)
 {
 	if (evdev->grab != client)
 		return  -EINVAL;

 	rcu_assign_pointer(evdev->grab, NULL);
 	synchronize_rcu();
 	input_release_device(&evdev->handle);

 	return 0;
 }

 static void evdev_attach_client(struct evdev *evdev,
 				struct evdev_client *client)
 {
 	spin_lock(&evdev->client_lock);
 	list_add_tail_rcu(&client->node, &evdev->client_list);
 	spin_unlock(&evdev->client_lock);
 	synchronize_rcu();
 }

 static void evdev_detach_client(struct evdev *evdev,
 				struct evdev_client *client)
 {
 	spin_lock(&evdev->client_lock);
 	list_del_rcu(&client->node);
 	spin_unlock(&evdev->client_lock);
 	synchronize_rcu();
 }

 static int evdev_open_device(struct evdev *evdev)
 {
 	int retval;

 	retval = mutex_lock_interruptible(&evdev->mutex);
 	if (retval)
 		return retval;

 	if (!evdev->exist)
 		retval = -ENODEV;
 	else if (!evdev->open++) {
 		retval = input_open_device(&evdev->handle);
 		if (retval)
 			evdev->open--;
 	}

 	mutex_unlock(&evdev->mutex);
 	return retval;
 }

 static void evdev_close_device(struct evdev *evdev)
 {
 	mutex_lock(&evdev->mutex);

 	if (evdev->exist && !--evdev->open)
 		input_close_device(&evdev->handle);

 	mutex_unlock(&evdev->mutex);
 }

 /*
  * Wake up users waiting for IO so they can disconnect from
  * dead device.
  */
 static void evdev_hangup(struct evdev *evdev)
 {
 	struct evdev_client *client;

 	spin_lock(&evdev->client_lock);
 	list_for_each_entry(client, &evdev->client_list, node)
 		kill_fasync(&client->fasync, SIGIO, POLL_HUP);
 	spin_unlock(&evdev->client_lock);

 	wake_up_interruptible(&evdev->wait);
 }

 static int evdev_release(struct inode *inode, struct file *file)
 {
 	struct evdev_client *client = file->private_data;
 	struct evdev *evdev = client->evdev;

 	mutex_lock(&evdev->mutex);
 	if (evdev->grab == client)
 		evdev_ungrab(evdev, client);
 	mutex_unlock(&evdev->mutex);

 	evdev_detach_client(evdev, client);
 	kfree(client);

 	evdev_close_device(evdev);
 	put_device(&evdev->dev);

 	return 0;
 }

 static int evdev_open(struct inode *inode, struct file *file)
 {
 	struct evdev *evdev;
 	struct evdev_client *client;
 	int i = iminor(inode) - EVDEV_MINOR_BASE;
 	int error;

 	if (i >= EVDEV_MINORS)
 		return -ENODEV;

 	error = mutex_lock_interruptible(&evdev_table_mutex);
 	if (error)
 		return error;
 	evdev = evdev_table[i];
 	if (evdev)
 		get_device(&evdev->dev);
 	mutex_unlock(&evdev_table_mutex);

 	if (!evdev)
 		return -ENODEV;

 	client = kzalloc(sizeof(struct evdev_client), GFP_KERNEL);
 	if (!client) {
 		error = -ENOMEM;
 		goto err_put_evdev;
 	}

 	spin_lock_init(&client->buffer_lock);
 	client->evdev = evdev;
 	evdev_attach_client(evdev, client);

 	error = evdev_open_device(evdev);
 	if (error)
 		goto err_free_client;

 	file->private_data = client;
 	nonseekable_open(inode, file);

 	return 0;

  err_free_client:
 	evdev_detach_client(evdev, client);
 	kfree(client);
  err_put_evdev:
 	put_device(&evdev->dev);
 	return error;
 }

 static ssize_t evdev_write(struct file *file, const char __user *buffer,
 			   size_t count, loff_t *ppos)
 {
 	struct evdev_client *client = file->private_data;
 	struct evdev *evdev = client->evdev;
 	struct input_event event;
 	int retval;

 	retval = mutex_lock_interruptible(&evdev->mutex);
 	if (retval)
 		return retval;

 	if (!evdev->exist) {
 		retval = -ENODEV;
 		goto out;
 	}

 	while (retval < count) {

 		if (input_event_from_user(buffer + retval, &event)) {
 			retval = -EFAULT;
 			goto out;
 		}

 		input_inject_event(&evdev->handle,
 				   event.type, event.code, event.value);
 		retval += input_event_size();
 	}

  out:
 	mutex_unlock(&evdev->mutex);
 	return retval;
 }

 static int evdev_fetch_next_event(struct evdev_client *client,
 				  struct input_event *event)
 {
 	int have_event;

 	spin_lock_irq(&client->buffer_lock);

 	have_event = client->head != client->tail;
 	if (have_event) {
 		*event = client->buffer[client->tail++];
 		client->tail &= EVDEV_BUFFER_SIZE - 1;
 	}

 	spin_unlock_irq(&client->buffer_lock);

 	return have_event;
 }

 static ssize_t evdev_read(struct file *file, char __user *buffer,
 			  size_t count, loff_t *ppos)
 {
 	struct evdev_client *client = file->private_data;
 	struct evdev *evdev = client->evdev;
 	struct input_event event;
 	int retval;

 	if (count < input_event_size())
 		return -EINVAL;

 	if (client->head == client->tail && evdev->exist &&
 	    (file->f_flags & O_NONBLOCK))
 		return -EAGAIN;

 	retval = wait_event_interruptible(evdev->wait,
 		client->head != client->tail || !evdev->exist);
 	if (retval)
 		return retval;

 	if (!evdev->exist)
 		return -ENODEV;

 	while (retval + input_event_size() <= count &&
 	       evdev_fetch_next_event(client, &event)) {

 		if (input_event_to_user(buffer + retval, &event))
 			return -EFAULT;

 		retval += input_event_size();
 	}

 	return retval;
 }

 /* No kernel lock - fine */
 static unsigned int evdev_poll(struct file *file, poll_table *wait)
 {
 	struct evdev_client *client = file->private_data;
 	struct evdev *evdev = client->evdev;

 	poll_wait(file, &evdev->wait, wait);
 	return ((client->head == client->tail) ? 0 : (POLLIN | POLLRDNORM)) |
 		(evdev->exist ? 0 : (POLLHUP | POLLERR));
 }

 #ifdef CONFIG_COMPAT

 #define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8)
 #define BITS_TO_LONGS_COMPAT(x) ((((x) - 1) / BITS_PER_LONG_COMPAT) + 1)

 #ifdef __BIG_ENDIAN
 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 			unsigned int maxlen, void __user *p, int compat)
 {
 	int len, i;

 	if (compat) {
 		len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
 		if (len > maxlen)
 			len = maxlen;

 		for (i = 0; i < len / sizeof(compat_long_t); i++)
 			if (copy_to_user((compat_long_t __user *) p + i,
 					 (compat_long_t *) bits +
 						i + 1 - ((i % 2) << 1),
 					 sizeof(compat_long_t)))
 				return -EFAULT;
 	} else {
 		len = BITS_TO_LONGS(maxbit) * sizeof(long);
 		if (len > maxlen)
 			len = maxlen;

 		if (copy_to_user(p, bits, len))
 			return -EFAULT;
 	}

 	return len;
 }
 #else
 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 			unsigned int maxlen, void __user *p, int compat)
 {
 	int len = compat ?
 			BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t) :
 			BITS_TO_LONGS(maxbit) * sizeof(long);

 	if (len > maxlen)
 		len = maxlen;

 	return copy_to_user(p, bits, len) ? -EFAULT : len;
 }
 #endif /* __BIG_ENDIAN */

 #else

 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 			unsigned int maxlen, void __user *p, int compat)
 {
 	int len = BITS_TO_LONGS(maxbit) * sizeof(long);

 	if (len > maxlen)
 		len = maxlen;

 	return copy_to_user(p, bits, len) ? -EFAULT : len;
 }

 #endif /* CONFIG_COMPAT */

 static int str_to_user(const char *str, unsigned int maxlen, void __user *p)
 {
 	int len;

 	if (!str)
 		return -ENOENT;

 	len = strlen(str) + 1;
 	if (len > maxlen)
 		len = maxlen;

 	return copy_to_user(p, str, len) ? -EFAULT : len;
 }

 #define OLD_KEY_MAX	0x1ff
 static int handle_eviocgbit(struct input_dev *dev, unsigned int cmd, void __user *p, int compat_mode)
 {
 	static unsigned long keymax_warn_time;
 	unsigned long *bits;
 	int len;

 	switch (_IOC_NR(cmd) & EV_MAX) {

 	case      0: bits = dev->evbit;  len = EV_MAX;  break;
 	case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
 	case EV_REL: bits = dev->relbit; len = REL_MAX; break;
 	case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
 	case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break;
 	case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
 	case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
 	case EV_FF:  bits = dev->ffbit;  len = FF_MAX;  break;
 	case EV_SW:  bits = dev->swbit;  len = SW_MAX;  break;
 	default: return -EINVAL;
 	}

 	/*
 	 * Work around bugs in userspace programs that like to do
 	 * EVIOCGBIT(EV_KEY, KEY_MAX) and not realize that 'len'
 	 * should be in bytes, not in bits.
 	 */
 	if ((_IOC_NR(cmd) & EV_MAX) == EV_KEY && _IOC_SIZE(cmd) == OLD_KEY_MAX) {
 		len = OLD_KEY_MAX;
 		if (printk_timed_ratelimit(&keymax_warn_time, 10 * 1000))
 			printk(KERN_WARNING
 				"evdev.c(EVIOCGBIT): Suspicious buffer size %u, "
 				"limiting output to %zu bytes. See "
 				"http://userweb.kernel.org/~dtor/eviocgbit-bug.html\n",
 				OLD_KEY_MAX,
 				BITS_TO_LONGS(OLD_KEY_MAX) * sizeof(long));
 	}

 	return bits_to_user(bits, len, _IOC_SIZE(cmd), p, compat_mode);
 }
 #undef OLD_KEY_MAX

 static long evdev_do_ioctl(struct file *file, unsigned int cmd,
 			   void __user *p, int compat_mode)
 {
 	struct evdev_client *client = file->private_data;
 	struct evdev *evdev = client->evdev;
 	struct input_dev *dev = evdev->handle.dev;
 	struct input_absinfo abs;
 	struct ff_effect effect;
 	int __user *ip = (int __user *)p;
 	int i, t, u, v;
 	int error;

 	switch (cmd) {

 	case EVIOCGVERSION:
 		return put_user(EV_VERSION, ip);

 	case EVIOCGID:
 		if (copy_to_user(p, &dev->id, sizeof(struct input_id)))
 			return -EFAULT;
 		return 0;

 	case EVIOCGREP:
 		if (!test_bit(EV_REP, dev->evbit))
 			return -ENOSYS;
 		if (put_user(dev->rep[REP_DELAY], ip))
 			return -EFAULT;
 		if (put_user(dev->rep[REP_PERIOD], ip + 1))
 			return -EFAULT;
 		return 0;

 	case EVIOCSREP:
 		if (!test_bit(EV_REP, dev->evbit))
 			return -ENOSYS;
 		if (get_user(u, ip))
 			return -EFAULT;
 		if (get_user(v, ip + 1))
 			return -EFAULT;

 		input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u);
 		input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v);

 		return 0;

 	case EVIOCGKEYCODE:
 		if (get_user(t, ip))
 			return -EFAULT;

 		error = input_get_keycode(dev, t, &v);
 		if (error)
 			return error;

 		if (put_user(v, ip + 1))
 			return -EFAULT;

 		return 0;

 	case EVIOCSKEYCODE:
 		if (get_user(t, ip) || get_user(v, ip + 1))
 			return -EFAULT;

 		return input_set_keycode(dev, t, v);

 	case EVIOCRMFF:
 		return input_ff_erase(dev, (int)(unsigned long) p, file);

 	case EVIOCGEFFECTS:
 		i = test_bit(EV_FF, dev->evbit) ?
 				dev->ff->max_effects : 0;
 		if (put_user(i, ip))
 			return -EFAULT;
 		return 0;

 	case EVIOCGRAB:
 		if (p)
 			return evdev_grab(evdev, client);
 		else
 			return evdev_ungrab(evdev, client);

 	default:

 		if (_IOC_TYPE(cmd) != 'E')
 			return -EINVAL;

 		if (_IOC_DIR(cmd) == _IOC_READ) {

 			if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0)))
 				return handle_eviocgbit(dev, cmd, p, compat_mode);

 			if (_IOC_NR(cmd) == _IOC_NR(EVIOCGKEY(0)))
 				return bits_to_user(dev->key, KEY_MAX, _IOC_SIZE(cmd),
 						    p, compat_mode);

 			if (_IOC_NR(cmd) == _IOC_NR(EVIOCGLED(0)))
 				return bits_to_user(dev->led, LED_MAX, _IOC_SIZE(cmd),
 						    p, compat_mode);

 			if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSND(0)))
 				return bits_to_user(dev->snd, SND_MAX, _IOC_SIZE(cmd),
 						    p, compat_mode);

 			if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSW(0)))
 				return bits_to_user(dev->sw, SW_MAX, _IOC_SIZE(cmd),
 						    p, compat_mode);

 			if (_IOC_NR(cmd) == _IOC_NR(EVIOCGNAME(0)))
 				return str_to_user(dev->name, _IOC_SIZE(cmd), p);

 			if (_IOC_NR(cmd) == _IOC_NR(EVIOCGPHYS(0)))
 				return str_to_user(dev->phys, _IOC_SIZE(cmd), p);

 			if (_IOC_NR(cmd) == _IOC_NR(EVIOCGUNIQ(0)))
 				return str_to_user(dev->uniq, _IOC_SIZE(cmd), p);

 			if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {

 				t = _IOC_NR(cmd) & ABS_MAX;

 				abs.value = dev->abs[t];
 				abs.minimum = dev->absmin[t];
 				abs.maximum = dev->absmax[t];
 				abs.fuzz = dev->absfuzz[t];
 				abs.flat = dev->absflat[t];
 				abs.resolution = dev->absres[t];

 				if (copy_to_user(p, &abs, min_t(size_t,
 								_IOC_SIZE(cmd),
 								sizeof(struct input_absinfo))))
 					return -EFAULT;

 				return 0;
 			}

 		}

 		if (_IOC_DIR(cmd) == _IOC_WRITE) {

 			if (_IOC_NR(cmd) == _IOC_NR(EVIOCSFF)) {

 				if (input_ff_effect_from_user(p, _IOC_SIZE(cmd), &effect))
 					return -EFAULT;

 				error = input_ff_upload(dev, &effect, file);

 				if (put_user(effect.id, &(((struct ff_effect __user *)p)->id)))
 					return -EFAULT;

 				return error;
 			}

 			if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) {

 				t = _IOC_NR(cmd) & ABS_MAX;

 				if (copy_from_user(&abs, p, min_t(size_t,
 								  _IOC_SIZE(cmd),
 								  sizeof(struct input_absinfo))))
 					return -EFAULT;

 				/*
 				 * Take event lock to ensure that we are not
 				 * changing device parameters in the middle
 				 * of event.
 				 */
 				spin_lock_irq(&dev->event_lock);

 				dev->abs[t] = abs.value;
 				dev->absmin[t] = abs.minimum;
 				dev->absmax[t] = abs.maximum;
 				dev->absfuzz[t] = abs.fuzz;
 				dev->absflat[t] = abs.flat;
 				dev->absres[t] = _IOC_SIZE(cmd) < sizeof(struct input_absinfo) ?
 							0 : abs.resolution;

 				spin_unlock_irq(&dev->event_lock);

 				return 0;
 			}
 		}
 	}
 	return -EINVAL;
 }

 static long evdev_ioctl_handler(struct file *file, unsigned int cmd,
 				void __user *p, int compat_mode)
 {
 	struct evdev_client *client = file->private_data;
 	struct evdev *evdev = client->evdev;
 	int retval;

 	retval = mutex_lock_interruptible(&evdev->mutex);
 	if (retval)
 		return retval;

 	if (!evdev->exist) {
 		retval = -ENODEV;
 		goto out;
 	}

 	retval = evdev_do_ioctl(file, cmd, p, compat_mode);

  out:
 	mutex_unlock(&evdev->mutex);
 	return retval;
 }

 static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
 	return evdev_ioctl_handler(file, cmd, (void __user *)arg, 0);
 }

 #ifdef CONFIG_COMPAT
 static long evdev_ioctl_compat(struct file *file,
 				unsigned int cmd, unsigned long arg)
 {
 	return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1);
 }
 #endif

 static const struct file_operations evdev_fops = {
 	.owner		= THIS_MODULE,
 	.read		= evdev_read,
 	.write		= evdev_write,
 	.poll		= evdev_poll,
 	.open		= evdev_open,
 	.release	= evdev_release,
 	.unlocked_ioctl	= evdev_ioctl,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl	= evdev_ioctl_compat,
 #endif
 	.fasync		= evdev_fasync,
 	.flush		= evdev_flush
 };

 static int evdev_install_chrdev(struct evdev *evdev)
 {
 	/*
 	 * No need to do any locking here as calls to connect and
 	 * disconnect are serialized by the input core
 	 */
 	evdev_table[evdev->minor] = evdev;
 	return 0;
 }

 static void evdev_remove_chrdev(struct evdev *evdev)
 {
 	/*
 	 * Lock evdev table to prevent race with evdev_open()
 	 */
 	mutex_lock(&evdev_table_mutex);
 	evdev_table[evdev->minor] = NULL;
 	mutex_unlock(&evdev_table_mutex);
 }

 /*
  * Mark device non-existent. This disables writes, ioctls and
  * prevents new users from opening the device. Already posted
  * blocking reads will stay, however new ones will fail.
  */
 static void evdev_mark_dead(struct evdev *evdev)
 {
 	mutex_lock(&evdev->mutex);
 	evdev->exist = 0;
 	mutex_unlock(&evdev->mutex);
 }

 static void evdev_cleanup(struct evdev *evdev)
 {
 	struct input_handle *handle = &evdev->handle;

 	evdev_mark_dead(evdev);
 	evdev_hangup(evdev);
 	evdev_remove_chrdev(evdev);

 	/* evdev is marked dead so no one else accesses evdev->open */
 	if (evdev->open) {
 		input_flush_device(handle, NULL);
 		input_close_device(handle);
 	}
 }

 /*
  * Create new evdev device. Note that input core serializes calls
  * to connect and disconnect so we don't need to lock evdev_table here.
  */
 static int evdev_connect(struct input_handler *handler, struct input_dev *dev,
 			 const struct input_device_id *id)
 {
 	struct evdev *evdev;
 	int minor;
 	int error;

 	for (minor = 0; minor < EVDEV_MINORS; minor++)
 		if (!evdev_table[minor])
 			break;

 	if (minor == EVDEV_MINORS) {
 		printk(KERN_ERR "evdev: no more free evdev devices\n");
 		return -ENFILE;
 	}

 	evdev = kzalloc(sizeof(struct evdev), GFP_KERNEL);
 	if (!evdev)
 		return -ENOMEM;

 	INIT_LIST_HEAD(&evdev->client_list);
 	spin_lock_init(&evdev->client_lock);
 	mutex_init(&evdev->mutex);
 	init_waitqueue_head(&evdev->wait);

 	dev_set_name(&evdev->dev, "event%d", minor);
 	evdev->exist = 1;
 	evdev->minor = minor;

 	evdev->handle.dev = input_get_device(dev);
 	evdev->handle.name = dev_name(&evdev->dev);
 	evdev->handle.handler = handler;
 	evdev->handle.private = evdev;

 	evdev->dev.devt = MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + minor);
 	evdev->dev.class = &input_class;
 	evdev->dev.parent = &dev->dev;
 	evdev->dev.release = evdev_free;
 	device_initialize(&evdev->dev);

 	error = input_register_handle(&evdev->handle);
 	if (error)
 		goto err_free_evdev;

 	error = evdev_install_chrdev(evdev);
 	if (error)
 		goto err_unregister_handle;

 	error = device_add(&evdev->dev);
 	if (error)
 		goto err_cleanup_evdev;

 	return 0;

  err_cleanup_evdev:
 	evdev_cleanup(evdev);
  err_unregister_handle:
 	input_unregister_handle(&evdev->handle);
  err_free_evdev:
 	put_device(&evdev->dev);
 	return error;
 }

 static void evdev_disconnect(struct input_handle *handle)
 {
 	struct evdev *evdev = handle->private;

 	device_del(&evdev->dev);
 	evdev_cleanup(evdev);
 	input_unregister_handle(handle);
 	put_device(&evdev->dev);
 }

 static const struct input_device_id evdev_ids[] = {
 	{ .driver_info = 1 },	/* Matches all devices */
 	{ },			/* Terminating zero entry */
 };

 MODULE_DEVICE_TABLE(input, evdev_ids);

 static struct input_handler evdev_handler = {
 	.event		= evdev_event,
 	.connect	= evdev_connect,
 	.disconnect	= evdev_disconnect,
 	.fops		= &evdev_fops,
 	.minor		= EVDEV_MINOR_BASE,
 	.name		= "evdev",
 	.id_table	= evdev_ids,
 };

 static int __init evdev_init(void)
 {
 	return input_register_handler(&evdev_handler);
 }

 static void __exit evdev_exit(void)
 {
 	input_unregister_handler(&evdev_handler);
 }

 module_init(evdev_init);
 module_exit(evdev_exit);

 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
 MODULE_DESCRIPTION("Input driver event char devices");
 MODULE_LICENSE("GPL");
	/*
	* Event char devices, giving access to raw input device events.
	*
	* 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.
	*/

	#define EVDEV_MINOR_BASE 64
	#define EVDEV_MINORS 32
	#define EVDEV_BUFFER_SIZE 64

	#include <linux/poll.h>
	#include <linux/sched.h>
	#include <linux/slab.h>
	#include <linux/module.h>
	#include <linux/init.h>
	#include <linux/input.h>
	#include <linux/major.h>
	#include <linux/device.h>
	#include "input-compat.h"

	struct evdev {
	int exist;
	int open;
	int minor;
	struct input_handle handle;
	wait_queue_head_t wait;
	struct evdev_client *grab;
	struct list_head client_list;
	spinlock_t client_lock; /* protects client_list */
	struct mutex mutex;
	struct device dev;
	};

	struct evdev_client {
	struct input_event buffer[EVDEV_BUFFER_SIZE];
	int head;
	int tail;
	spinlock_t buffer_lock; /* protects access to buffer, head and tail */
	struct fasync_struct *fasync;
	struct evdev *evdev;
	struct list_head node;
	};

	static struct evdev *evdev_table[EVDEV_MINORS];
	static DEFINE_MUTEX(evdev_table_mutex);

	static void evdev_pass_event(struct evdev_client *client,
	struct input_event *event)
	{
	/*
	* Interrupts are disabled, just acquire the lock
	*/
	spin_lock(&client->buffer_lock);
	client->buffer[client->head++] = *event;
	client->head &= EVDEV_BUFFER_SIZE - 1;
	spin_unlock(&client->buffer_lock);

	if (event->type == EV_SYN)
	kill_fasync(&client->fasync, SIGIO, POLL_IN);
	}

	/*
	* Pass incoming event to all connected clients.
	*/
	static void evdev_event(struct input_handle *handle,
	unsigned int type, unsigned int code, int value)
	{
	struct evdev *evdev = handle->private;
	struct evdev_client *client;
	struct input_event event;

	do_gettimeofday(&event.time);
	event.type = type;
	event.code = code;
	event.value = value;

	rcu_read_lock();

	client = rcu_dereference(evdev->grab);
	if (client)
	evdev_pass_event(client, &event);
	else
	list_for_each_entry_rcu(client, &evdev->client_list, node)
	evdev_pass_event(client, &event);

	rcu_read_unlock();

	wake_up_interruptible(&evdev->wait);
	}

	static int evdev_fasync(int fd, struct file *file, int on)
	{
	struct evdev_client *client = file->private_data;

	return fasync_helper(fd, file, on, &client->fasync);
	}

	static int evdev_flush(struct file *file, fl_owner_t id)
	{
	struct evdev_client *client = file->private_data;
	struct evdev *evdev = client->evdev;
	int retval;

	retval = mutex_lock_interruptible(&evdev->mutex);
	if (retval)
	return retval;

	if (!evdev->exist)
	retval = -ENODEV;
	else
	retval = input_flush_device(&evdev->handle, file);

	mutex_unlock(&evdev->mutex);
	return retval;
	}

	static void evdev_free(struct device *dev)
	{
	struct evdev *evdev = container_of(dev, struct evdev, dev);

	input_put_device(evdev->handle.dev);
	kfree(evdev);
	}

	/*
	* Grabs an event device (along with underlying input device).
	* This function is called with evdev->mutex taken.
	*/
	static int evdev_grab(struct evdev evdev, struct evdev_client client)
	{
	int error;

	if (evdev->grab)
	return -EBUSY;

	error = input_grab_device(&evdev->handle);
	if (error)
	return error;

	rcu_assign_pointer(evdev->grab, client);
	synchronize_rcu();

	return 0;
	}

	static int evdev_ungrab(struct evdev evdev, struct evdev_client client)
	{
	if (evdev->grab != client)
	return -EINVAL;

	rcu_assign_pointer(evdev->grab, NULL);
	synchronize_rcu();
	input_release_device(&evdev->handle);

	return 0;
	}

	static void evdev_attach_client(struct evdev *evdev,
	struct evdev_client *client)
	{
	spin_lock(&evdev->client_lock);
	list_add_tail_rcu(&client->node, &evdev->client_list);
	spin_unlock(&evdev->client_lock);
	synchronize_rcu();
	}

	static void evdev_detach_client(struct evdev *evdev,
	struct evdev_client *client)
	{
	spin_lock(&evdev->client_lock);
	list_del_rcu(&client->node);
	spin_unlock(&evdev->client_lock);
	synchronize_rcu();
	}

	static int evdev_open_device(struct evdev *evdev)
	{
	int retval;

	retval = mutex_lock_interruptible(&evdev->mutex);
	if (retval)
	return retval;

	if (!evdev->exist)
	retval = -ENODEV;
	else if (!evdev->open++) {
	retval = input_open_device(&evdev->handle);
	if (retval)
	evdev->open--;
	}

	mutex_unlock(&evdev->mutex);
	return retval;
	}

	static void evdev_close_device(struct evdev *evdev)
	{
	mutex_lock(&evdev->mutex);

	if (evdev->exist && !--evdev->open)
	input_close_device(&evdev->handle);

	mutex_unlock(&evdev->mutex);
	}

	/*
	* Wake up users waiting for IO so they can disconnect from
	* dead device.
	*/
	static void evdev_hangup(struct evdev *evdev)
	{
	struct evdev_client *client;

	spin_lock(&evdev->client_lock);
	list_for_each_entry(client, &evdev->client_list, node)
	kill_fasync(&client->fasync, SIGIO, POLL_HUP);
	spin_unlock(&evdev->client_lock);

	wake_up_interruptible(&evdev->wait);
	}

	static int evdev_release(struct inode inode, struct file file)
	{
	struct evdev_client *client = file->private_data;
	struct evdev *evdev = client->evdev;

	mutex_lock(&evdev->mutex);
	if (evdev->grab == client)
	evdev_ungrab(evdev, client);
	mutex_unlock(&evdev->mutex);

	evdev_detach_client(evdev, client);
	kfree(client);

	evdev_close_device(evdev);
	put_device(&evdev->dev);

	return 0;
	}

	static int evdev_open(struct inode inode, struct file file)
	{
	struct evdev *evdev;
	struct evdev_client *client;
	int i = iminor(inode) - EVDEV_MINOR_BASE;
	int error;

	if (i >= EVDEV_MINORS)
	return -ENODEV;

	error = mutex_lock_interruptible(&evdev_table_mutex);
	if (error)
	return error;
	evdev = evdev_table[i];
	if (evdev)
	get_device(&evdev->dev);
	mutex_unlock(&evdev_table_mutex);

	if (!evdev)
	return -ENODEV;

	client = kzalloc(sizeof(struct evdev_client), GFP_KERNEL);
	if (!client) {
	error = -ENOMEM;
	goto err_put_evdev;
	}

	spin_lock_init(&client->buffer_lock);
	client->evdev = evdev;
	evdev_attach_client(evdev, client);

	error = evdev_open_device(evdev);
	if (error)
	goto err_free_client;

	file->private_data = client;
	nonseekable_open(inode, file);

	return 0;

	err_free_client:
	evdev_detach_client(evdev, client);
	kfree(client);
	err_put_evdev:
	put_device(&evdev->dev);
	return error;
	}

	static ssize_t evdev_write(struct file file, const char __user buffer,
	size_t count, loff_t *ppos)
	{
	struct evdev_client *client = file->private_data;
	struct evdev *evdev = client->evdev;
	struct input_event event;
	int retval;

	retval = mutex_lock_interruptible(&evdev->mutex);
	if (retval)
	return retval;

	if (!evdev->exist) {
	retval = -ENODEV;
	goto out;
	}

	while (retval < count) {

	if (input_event_from_user(buffer + retval, &event)) {
	retval = -EFAULT;
	goto out;
	}

	input_inject_event(&evdev->handle,
	event.type, event.code, event.value);
	retval += input_event_size();
	}

	out:
	mutex_unlock(&evdev->mutex);
	return retval;
	}

	static int evdev_fetch_next_event(struct evdev_client *client,
	struct input_event *event)
	{
	int have_event;

	spin_lock_irq(&client->buffer_lock);

	have_event = client->head != client->tail;
	if (have_event) {
	*event = client->buffer[client->tail++];
	client->tail &= EVDEV_BUFFER_SIZE - 1;
	}

	spin_unlock_irq(&client->buffer_lock);

	return have_event;
	}

	static ssize_t evdev_read(struct file file, char __user buffer,
	size_t count, loff_t *ppos)
	{
	struct evdev_client *client = file->private_data;
	struct evdev *evdev = client->evdev;
	struct input_event event;
	int retval;

	if (count < input_event_size())
	return -EINVAL;

	if (client->head == client->tail && evdev->exist &&
	(file->f_flags & O_NONBLOCK))
	return -EAGAIN;

	retval = wait_event_interruptible(evdev->wait,
	client->head != client->tail \|\| !evdev->exist);
	if (retval)
	return retval;

	if (!evdev->exist)
	return -ENODEV;

	while (retval + input_event_size() <= count &&
	evdev_fetch_next_event(client, &event)) {

	if (input_event_to_user(buffer + retval, &event))
	return -EFAULT;

	retval += input_event_size();
	}

	return retval;
	}

	/* No kernel lock - fine */
	static unsigned int evdev_poll(struct file file, poll_table wait)
	{
	struct evdev_client *client = file->private_data;
	struct evdev *evdev = client->evdev;

	poll_wait(file, &evdev->wait, wait);
	return ((client->head == client->tail) ? 0 : (POLLIN \| POLLRDNORM)) \|
	(evdev->exist ? 0 : (POLLHUP \| POLLERR));
	}

	#ifdef CONFIG_COMPAT

	#define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8)
	#define BITS_TO_LONGS_COMPAT(x) ((((x) - 1) / BITS_PER_LONG_COMPAT) + 1)

	#ifdef __BIG_ENDIAN
	static int bits_to_user(unsigned long *bits, unsigned int maxbit,
	unsigned int maxlen, void __user *p, int compat)
	{
	int len, i;

	if (compat) {
	len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
	if (len > maxlen)
	len = maxlen;

	for (i = 0; i < len / sizeof(compat_long_t); i++)
	if (copy_to_user((compat_long_t __user *) p + i,
	(compat_long_t *) bits +
	i + 1 - ((i % 2) << 1),
	sizeof(compat_long_t)))
	return -EFAULT;
	} else {
	len = BITS_TO_LONGS(maxbit) * sizeof(long);
	if (len > maxlen)
	len = maxlen;

	if (copy_to_user(p, bits, len))
	return -EFAULT;
	}

	return len;
	}
	#else
	static int bits_to_user(unsigned long *bits, unsigned int maxbit,
	unsigned int maxlen, void __user *p, int compat)
	{
	int len = compat ?
	BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t) :
	BITS_TO_LONGS(maxbit) * sizeof(long);

	if (len > maxlen)
	len = maxlen;

	return copy_to_user(p, bits, len) ? -EFAULT : len;
	}
	#endif /* __BIG_ENDIAN */

	#else

	static int bits_to_user(unsigned long *bits, unsigned int maxbit,
	unsigned int maxlen, void __user *p, int compat)
	{
	int len = BITS_TO_LONGS(maxbit) * sizeof(long);

	if (len > maxlen)
	len = maxlen;

	return copy_to_user(p, bits, len) ? -EFAULT : len;
	}

	#endif /* CONFIG_COMPAT */

	static int str_to_user(const char str, unsigned int maxlen, void __user p)
	{
	int len;

	if (!str)
	return -ENOENT;

	len = strlen(str) + 1;
	if (len > maxlen)
	len = maxlen;

	return copy_to_user(p, str, len) ? -EFAULT : len;
	}

	#define OLD_KEY_MAX 0x1ff
	static int handle_eviocgbit(struct input_dev dev, unsigned int cmd, void __user p, int compat_mode)
	{
	static unsigned long keymax_warn_time;
	unsigned long *bits;
	int len;

	switch (_IOC_NR(cmd) & EV_MAX) {

	case 0: bits = dev->evbit; len = EV_MAX; break;
	case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
	case EV_REL: bits = dev->relbit; len = REL_MAX; break;
	case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
	case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break;
	case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
	case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
	case EV_FF: bits = dev->ffbit; len = FF_MAX; break;
	case EV_SW: bits = dev->swbit; len = SW_MAX; break;
	default: return -EINVAL;
	}

	/*
	* Work around bugs in userspace programs that like to do
	* EVIOCGBIT(EV_KEY, KEY_MAX) and not realize that 'len'
	* should be in bytes, not in bits.
	*/
	if ((_IOC_NR(cmd) & EV_MAX) == EV_KEY && _IOC_SIZE(cmd) == OLD_KEY_MAX) {
	len = OLD_KEY_MAX;
	if (printk_timed_ratelimit(&keymax_warn_time, 10 * 1000))
	printk(KERN_WARNING
	"evdev.c(EVIOCGBIT): Suspicious buffer size %u, "
	"limiting output to %zu bytes. See "
	"http://userweb.kernel.org/~dtor/eviocgbit-bug.html\n",
	OLD_KEY_MAX,
	BITS_TO_LONGS(OLD_KEY_MAX) * sizeof(long));
	}

	return bits_to_user(bits, len, _IOC_SIZE(cmd), p, compat_mode);
	}
	#undef OLD_KEY_MAX

	static long evdev_do_ioctl(struct file *file, unsigned int cmd,
	void __user *p, int compat_mode)
	{
	struct evdev_client *client = file->private_data;
	struct evdev *evdev = client->evdev;
	struct input_dev *dev = evdev->handle.dev;
	struct input_absinfo abs;
	struct ff_effect effect;
	int __user ip = (int __user )p;
	int i, t, u, v;
	int error;

	switch (cmd) {

	case EVIOCGVERSION:
	return put_user(EV_VERSION, ip);

	case EVIOCGID:
	if (copy_to_user(p, &dev->id, sizeof(struct input_id)))
	return -EFAULT;
	return 0;

	case EVIOCGREP:
	if (!test_bit(EV_REP, dev->evbit))
	return -ENOSYS;
	if (put_user(dev->rep[REP_DELAY], ip))
	return -EFAULT;
	if (put_user(dev->rep[REP_PERIOD], ip + 1))
	return -EFAULT;
	return 0;

	case EVIOCSREP:
	if (!test_bit(EV_REP, dev->evbit))
	return -ENOSYS;
	if (get_user(u, ip))
	return -EFAULT;
	if (get_user(v, ip + 1))
	return -EFAULT;

	input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u);
	input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v);

	return 0;

	case EVIOCGKEYCODE:
	if (get_user(t, ip))
	return -EFAULT;

	error = input_get_keycode(dev, t, &v);
	if (error)
	return error;

	if (put_user(v, ip + 1))
	return -EFAULT;

	return 0;

	case EVIOCSKEYCODE:
	if (get_user(t, ip) \|\| get_user(v, ip + 1))
	return -EFAULT;

	return input_set_keycode(dev, t, v);

	case EVIOCRMFF:
	return input_ff_erase(dev, (int)(unsigned long) p, file);

	case EVIOCGEFFECTS:
	i = test_bit(EV_FF, dev->evbit) ?
	dev->ff->max_effects : 0;
	if (put_user(i, ip))
	return -EFAULT;
	return 0;

	case EVIOCGRAB:
	if (p)
	return evdev_grab(evdev, client);
	else
	return evdev_ungrab(evdev, client);

	default:

	if (_IOC_TYPE(cmd) != 'E')
	return -EINVAL;

	if (_IOC_DIR(cmd) == _IOC_READ) {

	if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0)))
	return handle_eviocgbit(dev, cmd, p, compat_mode);

	if (_IOC_NR(cmd) == _IOC_NR(EVIOCGKEY(0)))
	return bits_to_user(dev->key, KEY_MAX, _IOC_SIZE(cmd),
	p, compat_mode);

	if (_IOC_NR(cmd) == _IOC_NR(EVIOCGLED(0)))
	return bits_to_user(dev->led, LED_MAX, _IOC_SIZE(cmd),
	p, compat_mode);

	if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSND(0)))
	return bits_to_user(dev->snd, SND_MAX, _IOC_SIZE(cmd),
	p, compat_mode);

	if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSW(0)))
	return bits_to_user(dev->sw, SW_MAX, _IOC_SIZE(cmd),
	p, compat_mode);

	if (_IOC_NR(cmd) == _IOC_NR(EVIOCGNAME(0)))
	return str_to_user(dev->name, _IOC_SIZE(cmd), p);

	if (_IOC_NR(cmd) == _IOC_NR(EVIOCGPHYS(0)))
	return str_to_user(dev->phys, _IOC_SIZE(cmd), p);

	if (_IOC_NR(cmd) == _IOC_NR(EVIOCGUNIQ(0)))
	return str_to_user(dev->uniq, _IOC_SIZE(cmd), p);

	if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {

	t = _IOC_NR(cmd) & ABS_MAX;

	abs.value = dev->abs[t];
	abs.minimum = dev->absmin[t];
	abs.maximum = dev->absmax[t];
	abs.fuzz = dev->absfuzz[t];
	abs.flat = dev->absflat[t];
	abs.resolution = dev->absres[t];

	if (copy_to_user(p, &abs, min_t(size_t,
	_IOC_SIZE(cmd),
	sizeof(struct input_absinfo))))
	return -EFAULT;

	return 0;
	}

	}

	if (_IOC_DIR(cmd) == _IOC_WRITE) {

	if (_IOC_NR(cmd) == _IOC_NR(EVIOCSFF)) {

	if (input_ff_effect_from_user(p, _IOC_SIZE(cmd), &effect))
	return -EFAULT;

	error = input_ff_upload(dev, &effect, file);

	if (put_user(effect.id, &(((struct ff_effect __user *)p)->id)))
	return -EFAULT;

	return error;
	}

	if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) {

	t = _IOC_NR(cmd) & ABS_MAX;

	if (copy_from_user(&abs, p, min_t(size_t,
	_IOC_SIZE(cmd),
	sizeof(struct input_absinfo))))
	return -EFAULT;

	/*
	* Take event lock to ensure that we are not
	* changing device parameters in the middle
	* of event.
	*/
	spin_lock_irq(&dev->event_lock);

	dev->abs[t] = abs.value;
	dev->absmin[t] = abs.minimum;
	dev->absmax[t] = abs.maximum;
	dev->absfuzz[t] = abs.fuzz;
	dev->absflat[t] = abs.flat;
	dev->absres[t] = _IOC_SIZE(cmd) < sizeof(struct input_absinfo) ?
	0 : abs.resolution;

	spin_unlock_irq(&dev->event_lock);

	return 0;
	}
	}
	}
	return -EINVAL;
	}

	static long evdev_ioctl_handler(struct file *file, unsigned int cmd,
	void __user *p, int compat_mode)
	{
	struct evdev_client *client = file->private_data;
	struct evdev *evdev = client->evdev;
	int retval;

	retval = mutex_lock_interruptible(&evdev->mutex);
	if (retval)
	return retval;

	if (!evdev->exist) {
	retval = -ENODEV;
	goto out;
	}

	retval = evdev_do_ioctl(file, cmd, p, compat_mode);

	out:
	mutex_unlock(&evdev->mutex);
	return retval;
	}

	static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
	{
	return evdev_ioctl_handler(file, cmd, (void __user *)arg, 0);
	}

	#ifdef CONFIG_COMPAT
	static long evdev_ioctl_compat(struct file *file,
	unsigned int cmd, unsigned long arg)
	{
	return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1);
	}
	#endif

	static const struct file_operations evdev_fops = {
	.owner = THIS_MODULE,
	.read = evdev_read,
	.write = evdev_write,
	.poll = evdev_poll,
	.open = evdev_open,
	.release = evdev_release,
	.unlocked_ioctl = evdev_ioctl,
	#ifdef CONFIG_COMPAT
	.compat_ioctl = evdev_ioctl_compat,
	#endif
	.fasync = evdev_fasync,
	.flush = evdev_flush
	};

	static int evdev_install_chrdev(struct evdev *evdev)
	{
	/*
	* No need to do any locking here as calls to connect and
	* disconnect are serialized by the input core
	*/
	evdev_table[evdev->minor] = evdev;
	return 0;
	}

	static void evdev_remove_chrdev(struct evdev *evdev)
	{
	/*
	* Lock evdev table to prevent race with evdev_open()
	*/
	mutex_lock(&evdev_table_mutex);
	evdev_table[evdev->minor] = NULL;
	mutex_unlock(&evdev_table_mutex);
	}

	/*
	* Mark device non-existent. This disables writes, ioctls and
	* prevents new users from opening the device. Already posted
	* blocking reads will stay, however new ones will fail.
	*/
	static void evdev_mark_dead(struct evdev *evdev)
	{
	mutex_lock(&evdev->mutex);
	evdev->exist = 0;
	mutex_unlock(&evdev->mutex);
	}

	static void evdev_cleanup(struct evdev *evdev)
	{
	struct input_handle *handle = &evdev->handle;

	evdev_mark_dead(evdev);
	evdev_hangup(evdev);
	evdev_remove_chrdev(evdev);

	/* evdev is marked dead so no one else accesses evdev->open */
	if (evdev->open) {
	input_flush_device(handle, NULL);
	input_close_device(handle);
	}
	}

	/*
	* Create new evdev device. Note that input core serializes calls
	* to connect and disconnect so we don't need to lock evdev_table here.
	*/
	static int evdev_connect(struct input_handler handler, struct input_dev dev,
	const struct input_device_id *id)
	{
	struct evdev *evdev;
	int minor;
	int error;

	for (minor = 0; minor < EVDEV_MINORS; minor++)
	if (!evdev_table[minor])
	break;

	if (minor == EVDEV_MINORS) {
	printk(KERN_ERR "evdev: no more free evdev devices\n");
	return -ENFILE;
	}

	evdev = kzalloc(sizeof(struct evdev), GFP_KERNEL);
	if (!evdev)
	return -ENOMEM;

	INIT_LIST_HEAD(&evdev->client_list);
	spin_lock_init(&evdev->client_lock);
	mutex_init(&evdev->mutex);
	init_waitqueue_head(&evdev->wait);

	dev_set_name(&evdev->dev, "event%d", minor);
	evdev->exist = 1;
	evdev->minor = minor;

	evdev->handle.dev = input_get_device(dev);
	evdev->handle.name = dev_name(&evdev->dev);
	evdev->handle.handler = handler;
	evdev->handle.private = evdev;

	evdev->dev.devt = MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + minor);
	evdev->dev.class = &input_class;
	evdev->dev.parent = &dev->dev;
	evdev->dev.release = evdev_free;
	device_initialize(&evdev->dev);

	error = input_register_handle(&evdev->handle);
	if (error)
	goto err_free_evdev;

	error = evdev_install_chrdev(evdev);
	if (error)
	goto err_unregister_handle;

	error = device_add(&evdev->dev);
	if (error)
	goto err_cleanup_evdev;

	return 0;

	err_cleanup_evdev:
	evdev_cleanup(evdev);
	err_unregister_handle:
	input_unregister_handle(&evdev->handle);
	err_free_evdev:
	put_device(&evdev->dev);
	return error;
	}

	static void evdev_disconnect(struct input_handle *handle)
	{
	struct evdev *evdev = handle->private;

	device_del(&evdev->dev);
	evdev_cleanup(evdev);
	input_unregister_handle(handle);
	put_device(&evdev->dev);
	}

	static const struct input_device_id evdev_ids[] = {
	{ .driver_info = 1 }, /* Matches all devices */
	{ }, /* Terminating zero entry */
	};

	MODULE_DEVICE_TABLE(input, evdev_ids);

	static struct input_handler evdev_handler = {
	.event = evdev_event,
	.connect = evdev_connect,
	.disconnect = evdev_disconnect,
	.fops = &evdev_fops,
	.minor = EVDEV_MINOR_BASE,
	.name = "evdev",
	.id_table = evdev_ids,
	};

	static int __init evdev_init(void)
	{
	return input_register_handler(&evdev_handler);
	}

	static void __exit evdev_exit(void)
	{
	input_unregister_handler(&evdev_handler);
	}

	module_init(evdev_init);
	module_exit(evdev_exit);

	MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
	MODULE_DESCRIPTION("Input driver event char devices");
	MODULE_LICENSE("GPL");