drivers/input/evdev.c - linux/kernel/git/mellanox/linux - Git at Google

 /*
  * 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/slab.h>
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/input.h>
 #include <linux/major.h>
 #include <linux/device.h>
 #include <linux/compat.h>

 struct evdev {
 	int exist;
 	int open;
 	int minor;
 	char name[16];
 	struct input_handle handle;
 	wait_queue_head_t wait;
 	struct evdev_client *grab;
 	struct list_head client_list;
 	struct device dev;
 };

 struct evdev_client {
 	struct input_event buffer[EVDEV_BUFFER_SIZE];
 	int head;
 	int tail;
 	struct fasync_struct *fasync;
 	struct evdev *evdev;
 	struct list_head node;
 };

 static struct evdev *evdev_table[EVDEV_MINORS];

 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;

 	if (evdev->grab) {
 		client = evdev->grab;

 		do_gettimeofday(&client->buffer[client->head].time);
 		client->buffer[client->head].type = type;
 		client->buffer[client->head].code = code;
 		client->buffer[client->head].value = value;
 		client->head = (client->head + 1) & (EVDEV_BUFFER_SIZE - 1);

 		kill_fasync(&client->fasync, SIGIO, POLL_IN);
 	} else
 		list_for_each_entry(client, &evdev->client_list, node) {

 			do_gettimeofday(&client->buffer[client->head].time);
 			client->buffer[client->head].type = type;
 			client->buffer[client->head].code = code;
 			client->buffer[client->head].value = value;
 			client->head = (client->head + 1) & (EVDEV_BUFFER_SIZE - 1);

 			kill_fasync(&client->fasync, SIGIO, POLL_IN);
 		}

 	wake_up_interruptible(&evdev->wait);
 }

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

 	retval = fasync_helper(fd, file, on, &client->fasync);

 	return retval < 0 ? retval : 0;
 }

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

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

 	return input_flush_device(&evdev->handle, file);
 }

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

 	evdev_table[evdev->minor] = NULL;
 	kfree(evdev);
 }

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

 	if (evdev->grab == client) {
 		input_release_device(&evdev->handle);
 		evdev->grab = NULL;
 	}

 	evdev_fasync(-1, file, 0);
 	list_del(&client->node);
 	kfree(client);

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

 	put_device(&evdev->dev);

 	return 0;
 }

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

 	if (i >= EVDEV_MINORS)
 		return -ENODEV;

 	evdev = evdev_table[i];

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

 	get_device(&evdev->dev);

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

 	client->evdev = evdev;
 	list_add_tail(&client->node, &evdev->client_list);

 	if (!evdev->open++ && evdev->exist) {
 		error = input_open_device(&evdev->handle);
 		if (error)
 			goto err_free_client;
 	}

 	file->private_data = client;
 	return 0;

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

 #ifdef CONFIG_COMPAT

 struct input_event_compat {
 	struct compat_timeval time;
 	__u16 type;
 	__u16 code;
 	__s32 value;
 };

 /* Note to the author of this code: did it ever occur to
    you why the ifdefs are needed? Think about it again. -AK */
 #ifdef CONFIG_X86_64
 #  define COMPAT_TEST is_compat_task()
 #elif defined(CONFIG_IA64)
 #  define COMPAT_TEST IS_IA32_PROCESS(task_pt_regs(current))
 #elif defined(CONFIG_S390)
 #  define COMPAT_TEST test_thread_flag(TIF_31BIT)
 #elif defined(CONFIG_MIPS)
 #  define COMPAT_TEST test_thread_flag(TIF_32BIT_ADDR)
 #else
 #  define COMPAT_TEST test_thread_flag(TIF_32BIT)
 #endif

 static inline size_t evdev_event_size(void)
 {
 	return COMPAT_TEST ?
 		sizeof(struct input_event_compat) : sizeof(struct input_event);
 }

 static int evdev_event_from_user(const char __user *buffer, struct input_event *event)
 {
 	if (COMPAT_TEST) {
 		struct input_event_compat compat_event;

 		if (copy_from_user(&compat_event, buffer, sizeof(struct input_event_compat)))
 			return -EFAULT;

 		event->time.tv_sec = compat_event.time.tv_sec;
 		event->time.tv_usec = compat_event.time.tv_usec;
 		event->type = compat_event.type;
 		event->code = compat_event.code;
 		event->value = compat_event.value;

 	} else {
 		if (copy_from_user(event, buffer, sizeof(struct input_event)))
 			return -EFAULT;
 	}

 	return 0;
 }

 static int evdev_event_to_user(char __user *buffer, const struct input_event *event)
 {
 	if (COMPAT_TEST) {
 		struct input_event_compat compat_event;

 		compat_event.time.tv_sec = event->time.tv_sec;
 		compat_event.time.tv_usec = event->time.tv_usec;
 		compat_event.type = event->type;
 		compat_event.code = event->code;
 		compat_event.value = event->value;

 		if (copy_to_user(buffer, &compat_event, sizeof(struct input_event_compat)))
 			return -EFAULT;

 	} else {
 		if (copy_to_user(buffer, event, sizeof(struct input_event)))
 			return -EFAULT;
 	}

 	return 0;
 }

 #else

 static inline size_t evdev_event_size(void)
 {
 	return sizeof(struct input_event);
 }

 static int evdev_event_from_user(const char __user *buffer, struct input_event *event)
 {
 	if (copy_from_user(event, buffer, sizeof(struct input_event)))
 		return -EFAULT;

 	return 0;
 }

 static int evdev_event_to_user(char __user *buffer, const struct input_event *event)
 {
 	if (copy_to_user(buffer, event, sizeof(struct input_event)))
 		return -EFAULT;

 	return 0;
 }

 #endif /* CONFIG_COMPAT */

 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 = 0;

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

 	while (retval < count) {

 		if (evdev_event_from_user(buffer + retval, &event))
 			return -EFAULT;
 		input_inject_event(&evdev->handle, event.type, event.code, event.value);
 		retval += evdev_event_size();
 	}

 	return retval;
 }

 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;
 	int retval;

 	if (count < evdev_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 (client->head != client->tail && retval + evdev_event_size() <= count) {

 		struct input_event *event = (struct input_event *) client->buffer + client->tail;

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

 		client->tail = (client->tail + 1) & (EVDEV_BUFFER_SIZE - 1);
 		retval += evdev_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 NBITS_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 = NBITS_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 = NBITS(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 ?
 			NBITS_COMPAT(maxbit) * sizeof(compat_long_t) :
 			NBITS(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 = NBITS(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;
 }

 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;
 	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;

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

 	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 = dev->getkeycode(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 dev->setkeycode(dev, t, v);

 		case EVIOCSFF:
 			if (copy_from_user(&effect, p, sizeof(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;

 		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) {
 				if (evdev->grab)
 					return -EBUSY;
 				if (input_grab_device(&evdev->handle))
 					return -EBUSY;
 				evdev->grab = client;
 				return 0;
 			} else {
 				if (evdev->grab != client)
 					return -EINVAL;
 				input_release_device(&evdev->handle);
 				evdev->grab = NULL;
 				return 0;
 			}

 		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))) {

 					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;
 					}
 					return bits_to_user(bits, len, _IOC_SIZE(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];

 					if (copy_to_user(p, &abs, sizeof(struct input_absinfo)))
 						return -EFAULT;

 					return 0;
 				}

 			}

 			if (_IOC_DIR(cmd) == _IOC_WRITE) {

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

 					t = _IOC_NR(cmd) & ABS_MAX;

 					if (copy_from_user(&abs, p, sizeof(struct input_absinfo)))
 						return -EFAULT;

 					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;

 					return 0;
 				}
 			}
 	}
 	return -EINVAL;
 }

 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_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 && evdev_table[minor]; minor++);
 	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);
 	init_waitqueue_head(&evdev->wait);

 	evdev->exist = 1;
 	evdev->minor = minor;
 	evdev->handle.dev = dev;
 	evdev->handle.name = evdev->name;
 	evdev->handle.handler = handler;
 	evdev->handle.private = evdev;
 	snprintf(evdev->name, sizeof(evdev->name), "event%d", minor);

 	snprintf(evdev->dev.bus_id, sizeof(evdev->dev.bus_id),
 		 "event%d", minor);
 	evdev->dev.class = &input_class;
 	evdev->dev.parent = &dev->dev;
 	evdev->dev.devt = MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + minor);
 	evdev->dev.release = evdev_free;
 	device_initialize(&evdev->dev);

 	evdev_table[minor] = evdev;

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

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

 	return 0;

  err_delete_evdev:
 	device_del(&evdev->dev);
  err_free_evdev:
 	put_device(&evdev->dev);
 	return error;
 }

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

 	input_unregister_handle(handle);
 	device_del(&evdev->dev);

 	evdev->exist = 0;

 	if (evdev->open) {
 		input_flush_device(handle, NULL);
 		input_close_device(handle);
 		list_for_each_entry(client, &evdev->client_list, node)
 			kill_fasync(&client->fasync, SIGIO, POLL_HUP);
 		wake_up_interruptible(&evdev->wait);
 	}

 	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/slab.h>
	#include <linux/module.h>
	#include <linux/init.h>
	#include <linux/input.h>
	#include <linux/major.h>
	#include <linux/device.h>
	#include <linux/compat.h>

	struct evdev {
	int exist;
	int open;
	int minor;
	char name[16];
	struct input_handle handle;
	wait_queue_head_t wait;
	struct evdev_client *grab;
	struct list_head client_list;
	struct device dev;
	};

	struct evdev_client {
	struct input_event buffer[EVDEV_BUFFER_SIZE];
	int head;
	int tail;
	struct fasync_struct *fasync;
	struct evdev *evdev;
	struct list_head node;
	};

	static struct evdev *evdev_table[EVDEV_MINORS];

	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;

	if (evdev->grab) {
	client = evdev->grab;

	do_gettimeofday(&client->buffer[client->head].time);
	client->buffer[client->head].type = type;
	client->buffer[client->head].code = code;
	client->buffer[client->head].value = value;
	client->head = (client->head + 1) & (EVDEV_BUFFER_SIZE - 1);

	kill_fasync(&client->fasync, SIGIO, POLL_IN);
	} else
	list_for_each_entry(client, &evdev->client_list, node) {

	do_gettimeofday(&client->buffer[client->head].time);
	client->buffer[client->head].type = type;
	client->buffer[client->head].code = code;
	client->buffer[client->head].value = value;
	client->head = (client->head + 1) & (EVDEV_BUFFER_SIZE - 1);

	kill_fasync(&client->fasync, SIGIO, POLL_IN);
	}

	wake_up_interruptible(&evdev->wait);
	}

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

	retval = fasync_helper(fd, file, on, &client->fasync);

	return retval < 0 ? retval : 0;
	}

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

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

	return input_flush_device(&evdev->handle, file);
	}

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

	evdev_table[evdev->minor] = NULL;
	kfree(evdev);
	}

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

	if (evdev->grab == client) {
	input_release_device(&evdev->handle);
	evdev->grab = NULL;
	}

	evdev_fasync(-1, file, 0);
	list_del(&client->node);
	kfree(client);

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

	put_device(&evdev->dev);

	return 0;
	}

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

	if (i >= EVDEV_MINORS)
	return -ENODEV;

	evdev = evdev_table[i];

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

	get_device(&evdev->dev);

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

	client->evdev = evdev;
	list_add_tail(&client->node, &evdev->client_list);

	if (!evdev->open++ && evdev->exist) {
	error = input_open_device(&evdev->handle);
	if (error)
	goto err_free_client;
	}

	file->private_data = client;
	return 0;

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

	#ifdef CONFIG_COMPAT

	struct input_event_compat {
	struct compat_timeval time;
	__u16 type;
	__u16 code;
	__s32 value;
	};

	/* Note to the author of this code: did it ever occur to
	you why the ifdefs are needed? Think about it again. -AK */
	#ifdef CONFIG_X86_64
	# define COMPAT_TEST is_compat_task()
	#elif defined(CONFIG_IA64)
	# define COMPAT_TEST IS_IA32_PROCESS(task_pt_regs(current))
	#elif defined(CONFIG_S390)
	# define COMPAT_TEST test_thread_flag(TIF_31BIT)
	#elif defined(CONFIG_MIPS)
	# define COMPAT_TEST test_thread_flag(TIF_32BIT_ADDR)
	#else
	# define COMPAT_TEST test_thread_flag(TIF_32BIT)
	#endif

	static inline size_t evdev_event_size(void)
	{
	return COMPAT_TEST ?
	sizeof(struct input_event_compat) : sizeof(struct input_event);
	}

	static int evdev_event_from_user(const char __user buffer, struct input_event event)
	{
	if (COMPAT_TEST) {
	struct input_event_compat compat_event;

	if (copy_from_user(&compat_event, buffer, sizeof(struct input_event_compat)))
	return -EFAULT;

	event->time.tv_sec = compat_event.time.tv_sec;
	event->time.tv_usec = compat_event.time.tv_usec;
	event->type = compat_event.type;
	event->code = compat_event.code;
	event->value = compat_event.value;

	} else {
	if (copy_from_user(event, buffer, sizeof(struct input_event)))
	return -EFAULT;
	}

	return 0;
	}

	static int evdev_event_to_user(char __user buffer, const struct input_event event)
	{
	if (COMPAT_TEST) {
	struct input_event_compat compat_event;

	compat_event.time.tv_sec = event->time.tv_sec;
	compat_event.time.tv_usec = event->time.tv_usec;
	compat_event.type = event->type;
	compat_event.code = event->code;
	compat_event.value = event->value;

	if (copy_to_user(buffer, &compat_event, sizeof(struct input_event_compat)))
	return -EFAULT;

	} else {
	if (copy_to_user(buffer, event, sizeof(struct input_event)))
	return -EFAULT;
	}

	return 0;
	}

	#else

	static inline size_t evdev_event_size(void)
	{
	return sizeof(struct input_event);
	}

	static int evdev_event_from_user(const char __user buffer, struct input_event event)
	{
	if (copy_from_user(event, buffer, sizeof(struct input_event)))
	return -EFAULT;

	return 0;
	}

	static int evdev_event_to_user(char __user buffer, const struct input_event event)
	{
	if (copy_to_user(buffer, event, sizeof(struct input_event)))
	return -EFAULT;

	return 0;
	}

	#endif /* CONFIG_COMPAT */

	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 = 0;

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

	while (retval < count) {

	if (evdev_event_from_user(buffer + retval, &event))
	return -EFAULT;
	input_inject_event(&evdev->handle, event.type, event.code, event.value);
	retval += evdev_event_size();
	}

	return retval;
	}

	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;
	int retval;

	if (count < evdev_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 (client->head != client->tail && retval + evdev_event_size() <= count) {

	struct input_event event = (struct input_event ) client->buffer + client->tail;

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

	client->tail = (client->tail + 1) & (EVDEV_BUFFER_SIZE - 1);
	retval += evdev_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 NBITS_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 = NBITS_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 = NBITS(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 ?
	NBITS_COMPAT(maxbit) * sizeof(compat_long_t) :
	NBITS(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 = NBITS(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;
	}

	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;
	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;

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

	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 = dev->getkeycode(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 dev->setkeycode(dev, t, v);

	case EVIOCSFF:
	if (copy_from_user(&effect, p, sizeof(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;

	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) {
	if (evdev->grab)
	return -EBUSY;
	if (input_grab_device(&evdev->handle))
	return -EBUSY;
	evdev->grab = client;
	return 0;
	} else {
	if (evdev->grab != client)
	return -EINVAL;
	input_release_device(&evdev->handle);
	evdev->grab = NULL;
	return 0;
	}

	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))) {

	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;
	}
	return bits_to_user(bits, len, _IOC_SIZE(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];

	if (copy_to_user(p, &abs, sizeof(struct input_absinfo)))
	return -EFAULT;

	return 0;
	}

	}

	if (_IOC_DIR(cmd) == _IOC_WRITE) {

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

	t = _IOC_NR(cmd) & ABS_MAX;

	if (copy_from_user(&abs, p, sizeof(struct input_absinfo)))
	return -EFAULT;

	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;

	return 0;
	}
	}
	}
	return -EINVAL;
	}

	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_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 && evdev_table[minor]; minor++);
	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);
	init_waitqueue_head(&evdev->wait);

	evdev->exist = 1;
	evdev->minor = minor;
	evdev->handle.dev = dev;
	evdev->handle.name = evdev->name;
	evdev->handle.handler = handler;
	evdev->handle.private = evdev;
	snprintf(evdev->name, sizeof(evdev->name), "event%d", minor);

	snprintf(evdev->dev.bus_id, sizeof(evdev->dev.bus_id),
	"event%d", minor);
	evdev->dev.class = &input_class;
	evdev->dev.parent = &dev->dev;
	evdev->dev.devt = MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + minor);
	evdev->dev.release = evdev_free;
	device_initialize(&evdev->dev);

	evdev_table[minor] = evdev;

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

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

	return 0;

	err_delete_evdev:
	device_del(&evdev->dev);
	err_free_evdev:
	put_device(&evdev->dev);
	return error;
	}

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

	input_unregister_handle(handle);
	device_del(&evdev->dev);

	evdev->exist = 0;

	if (evdev->open) {
	input_flush_device(handle, NULL);
	input_close_device(handle);
	list_for_each_entry(client, &evdev->client_list, node)
	kill_fasync(&client->fasync, SIGIO, POLL_HUP);
	wake_up_interruptible(&evdev->wait);
	}

	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");