drivers/input/joydev.c - fp2-dev/kernel/msm - Gitiles

 /*
  * Joystick device driver for the input driver suite.
  *
  * Copyright (c) 1999-2002 Vojtech Pavlik
  * Copyright (c) 1999 Colin Van Dyke
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  */

 #include <asm/io.h>
 #include <asm/system.h>
 #include <linux/delay.h>
 #include <linux/errno.h>
 #include <linux/joystick.h>
 #include <linux/input.h>
 #include <linux/kernel.h>
 #include <linux/major.h>
 #include <linux/slab.h>
 #include <linux/mm.h>
 #include <linux/miscdevice.h>
 #include <linux/module.h>
 #include <linux/poll.h>
 #include <linux/init.h>
 #include <linux/device.h>

 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
 MODULE_DESCRIPTION("Joystick device interfaces");
 MODULE_SUPPORTED_DEVICE("input/js");
 MODULE_LICENSE("GPL");

 #define JOYDEV_MINOR_BASE	0
 #define JOYDEV_MINORS		16
 #define JOYDEV_BUFFER_SIZE	64

 struct joydev {
 	int exist;
 	int open;
 	int minor;
 	char name[16];
 	struct input_handle handle;
 	wait_queue_head_t wait;
 	struct list_head client_list;
 	spinlock_t client_lock; /* protects client_list */
 	struct mutex mutex;
 	struct device dev;

 	struct js_corr corr[ABS_MAX + 1];
 	struct JS_DATA_SAVE_TYPE glue;
 	int nabs;
 	int nkey;
 	__u16 keymap[KEY_MAX - BTN_MISC + 1];
 	__u16 keypam[KEY_MAX - BTN_MISC + 1];
 	__u8 absmap[ABS_MAX + 1];
 	__u8 abspam[ABS_MAX + 1];
 	__s16 abs[ABS_MAX + 1];
 };

 struct joydev_client {
 	struct js_event buffer[JOYDEV_BUFFER_SIZE];
 	int head;
 	int tail;
 	int startup;
 	spinlock_t buffer_lock; /* protects access to buffer, head and tail */
 	struct fasync_struct *fasync;
 	struct joydev *joydev;
 	struct list_head node;
 };

 static struct joydev *joydev_table[JOYDEV_MINORS];
 static DEFINE_MUTEX(joydev_table_mutex);

 static int joydev_correct(int value, struct js_corr *corr)
 {
 	switch (corr->type) {

 	case JS_CORR_NONE:
 		break;

 	case JS_CORR_BROKEN:
 		value = value > corr->coef[0] ? (value < corr->coef[1] ? 0 :
 			((corr->coef[3] * (value - corr->coef[1])) >> 14)) :
 			((corr->coef[2] * (value - corr->coef[0])) >> 14);
 		break;

 	default:
 		return 0;
 	}

 	return value < -32767 ? -32767 : (value > 32767 ? 32767 : value);
 }

 static void joydev_pass_event(struct joydev_client *client,
 			      struct js_event *event)
 {
 	struct joydev *joydev = client->joydev;

 	/*
 	 * IRQs already disabled, just acquire the lock
 	 */
 	spin_lock(&client->buffer_lock);

 	client->buffer[client->head] = *event;

 	if (client->startup == joydev->nabs + joydev->nkey) {
 		client->head++;
 		client->head &= JOYDEV_BUFFER_SIZE - 1;
 		if (client->tail == client->head)
 			client->startup = 0;
 	}

 	spin_unlock(&client->buffer_lock);

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

 static void joydev_event(struct input_handle *handle,
 			 unsigned int type, unsigned int code, int value)
 {
 	struct joydev *joydev = handle->private;
 	struct joydev_client *client;
 	struct js_event event;

 	switch (type) {

 	case EV_KEY:
 		if (code < BTN_MISC || value == 2)
 			return;
 		event.type = JS_EVENT_BUTTON;
 		event.number = joydev->keymap[code - BTN_MISC];
 		event.value = value;
 		break;

 	case EV_ABS:
 		event.type = JS_EVENT_AXIS;
 		event.number = joydev->absmap[code];
 		event.value = joydev_correct(value,
 					&joydev->corr[event.number]);
 		if (event.value == joydev->abs[event.number])
 			return;
 		joydev->abs[event.number] = event.value;
 		break;

 	default:
 		return;
 	}

 	event.time = jiffies_to_msecs(jiffies);

 	rcu_read_lock();
 	list_for_each_entry_rcu(client, &joydev->client_list, node)
 		joydev_pass_event(client, &event);
 	rcu_read_unlock();

 	wake_up_interruptible(&joydev->wait);
 }

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

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

 static void joydev_free(struct device *dev)
 {
 	struct joydev *joydev = container_of(dev, struct joydev, dev);

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

 static void joydev_attach_client(struct joydev *joydev,
 				 struct joydev_client *client)
 {
 	spin_lock(&joydev->client_lock);
 	list_add_tail_rcu(&client->node, &joydev->client_list);
 	spin_unlock(&joydev->client_lock);
 	synchronize_rcu();
 }

 static void joydev_detach_client(struct joydev *joydev,
 				 struct joydev_client *client)
 {
 	spin_lock(&joydev->client_lock);
 	list_del_rcu(&client->node);
 	spin_unlock(&joydev->client_lock);
 	synchronize_rcu();
 }

 static int joydev_open_device(struct joydev *joydev)
 {
 	int retval;

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

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

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

 static void joydev_close_device(struct joydev *joydev)
 {
 	mutex_lock(&joydev->mutex);

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

 	mutex_unlock(&joydev->mutex);
 }

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

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

 	wake_up_interruptible(&joydev->wait);
 }

 static int joydev_release(struct inode *inode, struct file *file)
 {
 	struct joydev_client *client = file->private_data;
 	struct joydev *joydev = client->joydev;

 	joydev_detach_client(joydev, client);
 	kfree(client);

 	joydev_close_device(joydev);
 	put_device(&joydev->dev);

 	return 0;
 }

 static int joydev_open(struct inode *inode, struct file *file)
 {
 	struct joydev_client *client;
 	struct joydev *joydev;
 	int i = iminor(inode) - JOYDEV_MINOR_BASE;
 	int error;

 	if (i >= JOYDEV_MINORS)
 		return -ENODEV;

 	error = mutex_lock_interruptible(&joydev_table_mutex);
 	if (error)
 		return error;
 	joydev = joydev_table[i];
 	if (joydev)
 		get_device(&joydev->dev);
 	mutex_unlock(&joydev_table_mutex);

 	if (!joydev)
 		return -ENODEV;

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

 	spin_lock_init(&client->buffer_lock);
 	client->joydev = joydev;
 	joydev_attach_client(joydev, client);

 	error = joydev_open_device(joydev);
 	if (error)
 		goto err_free_client;

 	file->private_data = client;
 	return 0;

  err_free_client:
 	joydev_detach_client(joydev, client);
 	kfree(client);
  err_put_joydev:
 	put_device(&joydev->dev);
 	return error;
 }

 static int joydev_generate_startup_event(struct joydev_client *client,
 					 struct input_dev *input,
 					 struct js_event *event)
 {
 	struct joydev *joydev = client->joydev;
 	int have_event;

 	spin_lock_irq(&client->buffer_lock);

 	have_event = client->startup < joydev->nabs + joydev->nkey;

 	if (have_event) {

 		event->time = jiffies_to_msecs(jiffies);
 		if (client->startup < joydev->nkey) {
 			event->type = JS_EVENT_BUTTON | JS_EVENT_INIT;
 			event->number = client->startup;
 			event->value = !!test_bit(joydev->keypam[event->number],
 						  input->key);
 		} else {
 			event->type = JS_EVENT_AXIS | JS_EVENT_INIT;
 			event->number = client->startup - joydev->nkey;
 			event->value = joydev->abs[event->number];
 		}
 		client->startup++;
 	}

 	spin_unlock_irq(&client->buffer_lock);

 	return have_event;
 }

 static int joydev_fetch_next_event(struct joydev_client *client,
 				   struct js_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 &= JOYDEV_BUFFER_SIZE - 1;
 	}

 	spin_unlock_irq(&client->buffer_lock);

 	return have_event;
 }

 /*
  * Old joystick interface
  */
 static ssize_t joydev_0x_read(struct joydev_client *client,
 			      struct input_dev *input,
 			      char __user *buf)
 {
 	struct joydev *joydev = client->joydev;
 	struct JS_DATA_TYPE data;
 	int i;

 	spin_lock_irq(&input->event_lock);

 	/*
 	 * Get device state
 	 */
 	for (data.buttons = i = 0; i < 32 && i < joydev->nkey; i++)
 		data.buttons |=
 			test_bit(joydev->keypam[i], input->key) ? (1 << i) : 0;
 	data.x = (joydev->abs[0] / 256 + 128) >> joydev->glue.JS_CORR.x;
 	data.y = (joydev->abs[1] / 256 + 128) >> joydev->glue.JS_CORR.y;

 	/*
 	 * Reset reader's event queue
 	 */
 	spin_lock(&client->buffer_lock);
 	client->startup = 0;
 	client->tail = client->head;
 	spin_unlock(&client->buffer_lock);

 	spin_unlock_irq(&input->event_lock);

 	if (copy_to_user(buf, &data, sizeof(struct JS_DATA_TYPE)))
 		return -EFAULT;

 	return sizeof(struct JS_DATA_TYPE);
 }

 static inline int joydev_data_pending(struct joydev_client *client)
 {
 	struct joydev *joydev = client->joydev;

 	return client->startup < joydev->nabs + joydev->nkey ||
 		client->head != client->tail;
 }

 static ssize_t joydev_read(struct file *file, char __user *buf,
 			   size_t count, loff_t *ppos)
 {
 	struct joydev_client *client = file->private_data;
 	struct joydev *joydev = client->joydev;
 	struct input_dev *input = joydev->handle.dev;
 	struct js_event event;
 	int retval;

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

 	if (count < sizeof(struct js_event))
 		return -EINVAL;

 	if (count == sizeof(struct JS_DATA_TYPE))
 		return joydev_0x_read(client, input, buf);

 	if (!joydev_data_pending(client) && (file->f_flags & O_NONBLOCK))
 		return -EAGAIN;

 	retval = wait_event_interruptible(joydev->wait,
 			!joydev->exist || joydev_data_pending(client));
 	if (retval)
 		return retval;

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

 	while (retval + sizeof(struct js_event) <= count &&
 	       joydev_generate_startup_event(client, input, &event)) {

 		if (copy_to_user(buf + retval, &event, sizeof(struct js_event)))
 			return -EFAULT;

 		retval += sizeof(struct js_event);
 	}

 	while (retval + sizeof(struct js_event) <= count &&
 	       joydev_fetch_next_event(client, &event)) {

 		if (copy_to_user(buf + retval, &event, sizeof(struct js_event)))
 			return -EFAULT;

 		retval += sizeof(struct js_event);
 	}

 	return retval;
 }

 /* No kernel lock - fine */
 static unsigned int joydev_poll(struct file *file, poll_table *wait)
 {
 	struct joydev_client *client = file->private_data;
 	struct joydev *joydev = client->joydev;

 	poll_wait(file, &joydev->wait, wait);
 	return (joydev_data_pending(client) ? (POLLIN | POLLRDNORM) : 0) |
 		(joydev->exist ?  0 : (POLLHUP | POLLERR));
 }

 static int joydev_ioctl_common(struct joydev *joydev,
 				unsigned int cmd, void __user *argp)
 {
 	struct input_dev *dev = joydev->handle.dev;
 	int i, j;

 	switch (cmd) {

 	case JS_SET_CAL:
 		return copy_from_user(&joydev->glue.JS_CORR, argp,
 				sizeof(joydev->glue.JS_CORR)) ? -EFAULT : 0;

 	case JS_GET_CAL:
 		return copy_to_user(argp, &joydev->glue.JS_CORR,
 				sizeof(joydev->glue.JS_CORR)) ? -EFAULT : 0;

 	case JS_SET_TIMEOUT:
 		return get_user(joydev->glue.JS_TIMEOUT, (s32 __user *) argp);

 	case JS_GET_TIMEOUT:
 		return put_user(joydev->glue.JS_TIMEOUT, (s32 __user *) argp);

 	case JSIOCGVERSION:
 		return put_user(JS_VERSION, (__u32 __user *) argp);

 	case JSIOCGAXES:
 		return put_user(joydev->nabs, (__u8 __user *) argp);

 	case JSIOCGBUTTONS:
 		return put_user(joydev->nkey, (__u8 __user *) argp);

 	case JSIOCSCORR:
 		if (copy_from_user(joydev->corr, argp,
 			      sizeof(joydev->corr[0]) * joydev->nabs))
 		    return -EFAULT;

 		for (i = 0; i < joydev->nabs; i++) {
 			j = joydev->abspam[i];
 			joydev->abs[i] = joydev_correct(dev->abs[j],
 							&joydev->corr[i]);
 		}
 		return 0;

 	case JSIOCGCORR:
 		return copy_to_user(argp, joydev->corr,
 			sizeof(joydev->corr[0]) * joydev->nabs) ? -EFAULT : 0;

 	case JSIOCSAXMAP:
 		if (copy_from_user(joydev->abspam, argp,
 				   sizeof(__u8) * (ABS_MAX + 1)))
 			return -EFAULT;

 		for (i = 0; i < joydev->nabs; i++) {
 			if (joydev->abspam[i] > ABS_MAX)
 				return -EINVAL;
 			joydev->absmap[joydev->abspam[i]] = i;
 		}
 		return 0;

 	case JSIOCGAXMAP:
 		return copy_to_user(argp, joydev->abspam,
 			sizeof(__u8) * (ABS_MAX + 1)) ? -EFAULT : 0;

 	case JSIOCSBTNMAP:
 		if (copy_from_user(joydev->keypam, argp,
 				   sizeof(__u16) * (KEY_MAX - BTN_MISC + 1)))
 			return -EFAULT;

 		for (i = 0; i < joydev->nkey; i++) {
 			if (joydev->keypam[i] > KEY_MAX ||
 			    joydev->keypam[i] < BTN_MISC)
 				return -EINVAL;
 			joydev->keymap[joydev->keypam[i] - BTN_MISC] = i;
 		}

 		return 0;

 	case JSIOCGBTNMAP:
 		return copy_to_user(argp, joydev->keypam,
 			sizeof(__u16) * (KEY_MAX - BTN_MISC + 1)) ? -EFAULT : 0;

 	default:
 		if ((cmd & ~IOCSIZE_MASK) == JSIOCGNAME(0)) {
 			int len;
 			if (!dev->name)
 				return 0;
 			len = strlen(dev->name) + 1;
 			if (len > _IOC_SIZE(cmd))
 				len = _IOC_SIZE(cmd);
 			if (copy_to_user(argp, dev->name, len))
 				return -EFAULT;
 			return len;
 		}
 	}
 	return -EINVAL;
 }

 #ifdef CONFIG_COMPAT
 static long joydev_compat_ioctl(struct file *file,
 				unsigned int cmd, unsigned long arg)
 {
 	struct joydev_client *client = file->private_data;
 	struct joydev *joydev = client->joydev;
 	void __user *argp = (void __user *)arg;
 	s32 tmp32;
 	struct JS_DATA_SAVE_TYPE_32 ds32;
 	int retval;

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

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

 	switch (cmd) {

 	case JS_SET_TIMELIMIT:
 		retval = get_user(tmp32, (s32 __user *) arg);
 		if (retval == 0)
 			joydev->glue.JS_TIMELIMIT = tmp32;
 		break;

 	case JS_GET_TIMELIMIT:
 		tmp32 = joydev->glue.JS_TIMELIMIT;
 		retval = put_user(tmp32, (s32 __user *) arg);
 		break;

 	case JS_SET_ALL:
 		retval = copy_from_user(&ds32, argp,
 					sizeof(ds32)) ? -EFAULT : 0;
 		if (retval == 0) {
 			joydev->glue.JS_TIMEOUT    = ds32.JS_TIMEOUT;
 			joydev->glue.BUSY          = ds32.BUSY;
 			joydev->glue.JS_EXPIRETIME = ds32.JS_EXPIRETIME;
 			joydev->glue.JS_TIMELIMIT  = ds32.JS_TIMELIMIT;
 			joydev->glue.JS_SAVE       = ds32.JS_SAVE;
 			joydev->glue.JS_CORR       = ds32.JS_CORR;
 		}
 		break;

 	case JS_GET_ALL:
 		ds32.JS_TIMEOUT    = joydev->glue.JS_TIMEOUT;
 		ds32.BUSY          = joydev->glue.BUSY;
 		ds32.JS_EXPIRETIME = joydev->glue.JS_EXPIRETIME;
 		ds32.JS_TIMELIMIT  = joydev->glue.JS_TIMELIMIT;
 		ds32.JS_SAVE       = joydev->glue.JS_SAVE;
 		ds32.JS_CORR       = joydev->glue.JS_CORR;

 		retval = copy_to_user(argp, &ds32, sizeof(ds32)) ? -EFAULT : 0;
 		break;

 	default:
 		retval = joydev_ioctl_common(joydev, cmd, argp);
 		break;
 	}

  out:
 	mutex_unlock(&joydev->mutex);
 	return retval;
 }
 #endif /* CONFIG_COMPAT */

 static long joydev_ioctl(struct file *file,
 			 unsigned int cmd, unsigned long arg)
 {
 	struct joydev_client *client = file->private_data;
 	struct joydev *joydev = client->joydev;
 	void __user *argp = (void __user *)arg;
 	int retval;

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

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

 	switch (cmd) {

 	case JS_SET_TIMELIMIT:
 		retval = get_user(joydev->glue.JS_TIMELIMIT,
 				  (long __user *) arg);
 		break;

 	case JS_GET_TIMELIMIT:
 		retval = put_user(joydev->glue.JS_TIMELIMIT,
 				  (long __user *) arg);
 		break;

 	case JS_SET_ALL:
 		retval = copy_from_user(&joydev->glue, argp,
 					sizeof(joydev->glue)) ? -EFAULT: 0;
 		break;

 	case JS_GET_ALL:
 		retval = copy_to_user(argp, &joydev->glue,
 				      sizeof(joydev->glue)) ? -EFAULT : 0;
 		break;

 	default:
 		retval = joydev_ioctl_common(joydev, cmd, argp);
 		break;
 	}
  out:
 	mutex_unlock(&joydev->mutex);
 	return retval;
 }

 static const struct file_operations joydev_fops = {
 	.owner		= THIS_MODULE,
 	.read		= joydev_read,
 	.poll		= joydev_poll,
 	.open		= joydev_open,
 	.release	= joydev_release,
 	.unlocked_ioctl	= joydev_ioctl,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl	= joydev_compat_ioctl,
 #endif
 	.fasync		= joydev_fasync,
 };

 static int joydev_install_chrdev(struct joydev *joydev)
 {
 	joydev_table[joydev->minor] = joydev;
 	return 0;
 }

 static void joydev_remove_chrdev(struct joydev *joydev)
 {
 	mutex_lock(&joydev_table_mutex);
 	joydev_table[joydev->minor] = NULL;
 	mutex_unlock(&joydev_table_mutex);
 }

 /*
  * Mark device non-existant. 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 joydev_mark_dead(struct joydev *joydev)
 {
 	mutex_lock(&joydev->mutex);
 	joydev->exist = 0;
 	mutex_unlock(&joydev->mutex);
 }

 static void joydev_cleanup(struct joydev *joydev)
 {
 	struct input_handle *handle = &joydev->handle;

 	joydev_mark_dead(joydev);
 	joydev_hangup(joydev);
 	joydev_remove_chrdev(joydev);

 	/* joydev is marked dead so noone else accesses joydev->open */
 	if (joydev->open)
 		input_close_device(handle);
 }

 static int joydev_connect(struct input_handler *handler, struct input_dev *dev,
 			  const struct input_device_id *id)
 {
 	struct joydev *joydev;
 	int i, j, t, minor;
 	int error;

 	for (minor = 0; minor < JOYDEV_MINORS; minor++)
 		if (!joydev_table[minor])
 			break;

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

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

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

 	snprintf(joydev->name, sizeof(joydev->name), "js%d", minor);
 	joydev->exist = 1;
 	joydev->minor = minor;

 	joydev->exist = 1;
 	joydev->handle.dev = input_get_device(dev);
 	joydev->handle.name = joydev->name;
 	joydev->handle.handler = handler;
 	joydev->handle.private = joydev;

 	for (i = 0; i < ABS_MAX + 1; i++)
 		if (test_bit(i, dev->absbit)) {
 			joydev->absmap[i] = joydev->nabs;
 			joydev->abspam[joydev->nabs] = i;
 			joydev->nabs++;
 		}

 	for (i = BTN_JOYSTICK - BTN_MISC; i < KEY_MAX - BTN_MISC + 1; i++)
 		if (test_bit(i + BTN_MISC, dev->keybit)) {
 			joydev->keymap[i] = joydev->nkey;
 			joydev->keypam[joydev->nkey] = i + BTN_MISC;
 			joydev->nkey++;
 		}

 	for (i = 0; i < BTN_JOYSTICK - BTN_MISC; i++)
 		if (test_bit(i + BTN_MISC, dev->keybit)) {
 			joydev->keymap[i] = joydev->nkey;
 			joydev->keypam[joydev->nkey] = i + BTN_MISC;
 			joydev->nkey++;
 		}

 	for (i = 0; i < joydev->nabs; i++) {
 		j = joydev->abspam[i];
 		if (dev->absmax[j] == dev->absmin[j]) {
 			joydev->corr[i].type = JS_CORR_NONE;
 			joydev->abs[i] = dev->abs[j];
 			continue;
 		}
 		joydev->corr[i].type = JS_CORR_BROKEN;
 		joydev->corr[i].prec = dev->absfuzz[j];
 		joydev->corr[i].coef[0] =
 			(dev->absmax[j] + dev->absmin[j]) / 2 - dev->absflat[j];
 		joydev->corr[i].coef[1] =
 			(dev->absmax[j] + dev->absmin[j]) / 2 + dev->absflat[j];

 		t = (dev->absmax[j] - dev->absmin[j]) / 2 - 2 * dev->absflat[j];
 		if (t) {
 			joydev->corr[i].coef[2] = (1 << 29) / t;
 			joydev->corr[i].coef[3] = (1 << 29) / t;

 			joydev->abs[i] = joydev_correct(dev->abs[j],
 							joydev->corr + i);
 		}
 	}

 	dev_set_name(&joydev->dev, joydev->name);
 	joydev->dev.devt = MKDEV(INPUT_MAJOR, JOYDEV_MINOR_BASE + minor);
 	joydev->dev.class = &input_class;
 	joydev->dev.parent = &dev->dev;
 	joydev->dev.release = joydev_free;
 	device_initialize(&joydev->dev);

 	error = input_register_handle(&joydev->handle);
 	if (error)
 		goto err_free_joydev;

 	error = joydev_install_chrdev(joydev);
 	if (error)
 		goto err_unregister_handle;

 	error = device_add(&joydev->dev);
 	if (error)
 		goto err_cleanup_joydev;

 	return 0;

  err_cleanup_joydev:
 	joydev_cleanup(joydev);
  err_unregister_handle:
 	input_unregister_handle(&joydev->handle);
  err_free_joydev:
 	put_device(&joydev->dev);
 	return error;
 }

 static void joydev_disconnect(struct input_handle *handle)
 {
 	struct joydev *joydev = handle->private;

 	device_del(&joydev->dev);
 	joydev_cleanup(joydev);
 	input_unregister_handle(handle);
 	put_device(&joydev->dev);
 }

 static const struct input_device_id joydev_blacklist[] = {
 	{
 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 				INPUT_DEVICE_ID_MATCH_KEYBIT,
 		.evbit = { BIT_MASK(EV_KEY) },
 		.keybit = { [BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH) },
 	},	/* Avoid itouchpads and touchscreens */
 	{
 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 				INPUT_DEVICE_ID_MATCH_KEYBIT,
 		.evbit = { BIT_MASK(EV_KEY) },
 		.keybit = { [BIT_WORD(BTN_DIGI)] = BIT_MASK(BTN_DIGI) },
 	},	/* Avoid tablets, digitisers and similar devices */
 	{ }	/* Terminating entry */
 };

 static const struct input_device_id joydev_ids[] = {
 	{
 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 				INPUT_DEVICE_ID_MATCH_ABSBIT,
 		.evbit = { BIT_MASK(EV_ABS) },
 		.absbit = { BIT_MASK(ABS_X) },
 	},
 	{
 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 				INPUT_DEVICE_ID_MATCH_ABSBIT,
 		.evbit = { BIT_MASK(EV_ABS) },
 		.absbit = { BIT_MASK(ABS_WHEEL) },
 	},
 	{
 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 				INPUT_DEVICE_ID_MATCH_ABSBIT,
 		.evbit = { BIT_MASK(EV_ABS) },
 		.absbit = { BIT_MASK(ABS_THROTTLE) },
 	},
 	{ }	/* Terminating entry */
 };

 MODULE_DEVICE_TABLE(input, joydev_ids);

 static struct input_handler joydev_handler = {
 	.event		= joydev_event,
 	.connect	= joydev_connect,
 	.disconnect	= joydev_disconnect,
 	.fops		= &joydev_fops,
 	.minor		= JOYDEV_MINOR_BASE,
 	.name		= "joydev",
 	.id_table	= joydev_ids,
 	.blacklist	= joydev_blacklist,
 };

 static int __init joydev_init(void)
 {
 	return input_register_handler(&joydev_handler);
 }

 static void __exit joydev_exit(void)
 {
 	input_unregister_handler(&joydev_handler);
 }

 module_init(joydev_init);
 module_exit(joydev_exit);
	/*
	* Joystick device driver for the input driver suite.
	*
	* Copyright (c) 1999-2002 Vojtech Pavlik
	* Copyright (c) 1999 Colin Van Dyke
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* (at your option) any later version.
	*/

	#include <asm/io.h>
	#include <asm/system.h>
	#include <linux/delay.h>
	#include <linux/errno.h>
	#include <linux/joystick.h>
	#include <linux/input.h>
	#include <linux/kernel.h>
	#include <linux/major.h>
	#include <linux/slab.h>
	#include <linux/mm.h>
	#include <linux/miscdevice.h>
	#include <linux/module.h>
	#include <linux/poll.h>
	#include <linux/init.h>
	#include <linux/device.h>

	MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
	MODULE_DESCRIPTION("Joystick device interfaces");
	MODULE_SUPPORTED_DEVICE("input/js");
	MODULE_LICENSE("GPL");

	#define JOYDEV_MINOR_BASE 0
	#define JOYDEV_MINORS 16
	#define JOYDEV_BUFFER_SIZE 64

	struct joydev {
	int exist;
	int open;
	int minor;
	char name[16];
	struct input_handle handle;
	wait_queue_head_t wait;
	struct list_head client_list;
	spinlock_t client_lock; /* protects client_list */
	struct mutex mutex;
	struct device dev;

	struct js_corr corr[ABS_MAX + 1];
	struct JS_DATA_SAVE_TYPE glue;
	int nabs;
	int nkey;
	__u16 keymap[KEY_MAX - BTN_MISC + 1];
	__u16 keypam[KEY_MAX - BTN_MISC + 1];
	__u8 absmap[ABS_MAX + 1];
	__u8 abspam[ABS_MAX + 1];
	__s16 abs[ABS_MAX + 1];
	};

	struct joydev_client {
	struct js_event buffer[JOYDEV_BUFFER_SIZE];
	int head;
	int tail;
	int startup;
	spinlock_t buffer_lock; /* protects access to buffer, head and tail */
	struct fasync_struct *fasync;
	struct joydev *joydev;
	struct list_head node;
	};

	static struct joydev *joydev_table[JOYDEV_MINORS];
	static DEFINE_MUTEX(joydev_table_mutex);

	static int joydev_correct(int value, struct js_corr *corr)
	{
	switch (corr->type) {

	case JS_CORR_NONE:
	break;

	case JS_CORR_BROKEN:
	value = value > corr->coef[0] ? (value < corr->coef[1] ? 0 :
	((corr->coef[3] * (value - corr->coef[1])) >> 14)) :
	((corr->coef[2] * (value - corr->coef[0])) >> 14);
	break;

	default:
	return 0;
	}

	return value < -32767 ? -32767 : (value > 32767 ? 32767 : value);
	}

	static void joydev_pass_event(struct joydev_client *client,
	struct js_event *event)
	{
	struct joydev *joydev = client->joydev;

	/*
	* IRQs already disabled, just acquire the lock
	*/
	spin_lock(&client->buffer_lock);

	client->buffer[client->head] = *event;

	if (client->startup == joydev->nabs + joydev->nkey) {
	client->head++;
	client->head &= JOYDEV_BUFFER_SIZE - 1;
	if (client->tail == client->head)
	client->startup = 0;
	}

	spin_unlock(&client->buffer_lock);

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

	static void joydev_event(struct input_handle *handle,
	unsigned int type, unsigned int code, int value)
	{
	struct joydev *joydev = handle->private;
	struct joydev_client *client;
	struct js_event event;

	switch (type) {

	case EV_KEY:
	if (code < BTN_MISC \|\| value == 2)
	return;
	event.type = JS_EVENT_BUTTON;
	event.number = joydev->keymap[code - BTN_MISC];
	event.value = value;
	break;

	case EV_ABS:
	event.type = JS_EVENT_AXIS;
	event.number = joydev->absmap[code];
	event.value = joydev_correct(value,
	&joydev->corr[event.number]);
	if (event.value == joydev->abs[event.number])
	return;
	joydev->abs[event.number] = event.value;
	break;

	default:
	return;
	}

	event.time = jiffies_to_msecs(jiffies);

	rcu_read_lock();
	list_for_each_entry_rcu(client, &joydev->client_list, node)
	joydev_pass_event(client, &event);
	rcu_read_unlock();

	wake_up_interruptible(&joydev->wait);
	}

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

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

	static void joydev_free(struct device *dev)
	{
	struct joydev *joydev = container_of(dev, struct joydev, dev);

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

	static void joydev_attach_client(struct joydev *joydev,
	struct joydev_client *client)
	{
	spin_lock(&joydev->client_lock);
	list_add_tail_rcu(&client->node, &joydev->client_list);
	spin_unlock(&joydev->client_lock);
	synchronize_rcu();
	}

	static void joydev_detach_client(struct joydev *joydev,
	struct joydev_client *client)
	{
	spin_lock(&joydev->client_lock);
	list_del_rcu(&client->node);
	spin_unlock(&joydev->client_lock);
	synchronize_rcu();
	}

	static int joydev_open_device(struct joydev *joydev)
	{
	int retval;

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

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

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

	static void joydev_close_device(struct joydev *joydev)
	{
	mutex_lock(&joydev->mutex);

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

	mutex_unlock(&joydev->mutex);
	}

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

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

	wake_up_interruptible(&joydev->wait);
	}

	static int joydev_release(struct inode inode, struct file file)
	{
	struct joydev_client *client = file->private_data;
	struct joydev *joydev = client->joydev;

	joydev_detach_client(joydev, client);
	kfree(client);

	joydev_close_device(joydev);
	put_device(&joydev->dev);

	return 0;
	}

	static int joydev_open(struct inode inode, struct file file)
	{
	struct joydev_client *client;
	struct joydev *joydev;
	int i = iminor(inode) - JOYDEV_MINOR_BASE;
	int error;

	if (i >= JOYDEV_MINORS)
	return -ENODEV;

	error = mutex_lock_interruptible(&joydev_table_mutex);
	if (error)
	return error;
	joydev = joydev_table[i];
	if (joydev)
	get_device(&joydev->dev);
	mutex_unlock(&joydev_table_mutex);

	if (!joydev)
	return -ENODEV;

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

	spin_lock_init(&client->buffer_lock);
	client->joydev = joydev;
	joydev_attach_client(joydev, client);

	error = joydev_open_device(joydev);
	if (error)
	goto err_free_client;

	file->private_data = client;
	return 0;

	err_free_client:
	joydev_detach_client(joydev, client);
	kfree(client);
	err_put_joydev:
	put_device(&joydev->dev);
	return error;
	}

	static int joydev_generate_startup_event(struct joydev_client *client,
	struct input_dev *input,
	struct js_event *event)
	{
	struct joydev *joydev = client->joydev;
	int have_event;

	spin_lock_irq(&client->buffer_lock);

	have_event = client->startup < joydev->nabs + joydev->nkey;

	if (have_event) {

	event->time = jiffies_to_msecs(jiffies);
	if (client->startup < joydev->nkey) {
	event->type = JS_EVENT_BUTTON \| JS_EVENT_INIT;
	event->number = client->startup;
	event->value = !!test_bit(joydev->keypam[event->number],
	input->key);
	} else {
	event->type = JS_EVENT_AXIS \| JS_EVENT_INIT;
	event->number = client->startup - joydev->nkey;
	event->value = joydev->abs[event->number];
	}
	client->startup++;
	}

	spin_unlock_irq(&client->buffer_lock);

	return have_event;
	}

	static int joydev_fetch_next_event(struct joydev_client *client,
	struct js_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 &= JOYDEV_BUFFER_SIZE - 1;
	}

	spin_unlock_irq(&client->buffer_lock);

	return have_event;
	}

	/*
	* Old joystick interface
	*/
	static ssize_t joydev_0x_read(struct joydev_client *client,
	struct input_dev *input,
	char __user *buf)
	{
	struct joydev *joydev = client->joydev;
	struct JS_DATA_TYPE data;
	int i;

	spin_lock_irq(&input->event_lock);

	/*
	* Get device state
	*/
	for (data.buttons = i = 0; i < 32 && i < joydev->nkey; i++)
	data.buttons \|=
	test_bit(joydev->keypam[i], input->key) ? (1 << i) : 0;
	data.x = (joydev->abs[0] / 256 + 128) >> joydev->glue.JS_CORR.x;
	data.y = (joydev->abs[1] / 256 + 128) >> joydev->glue.JS_CORR.y;

	/*
	* Reset reader's event queue
	*/
	spin_lock(&client->buffer_lock);
	client->startup = 0;
	client->tail = client->head;
	spin_unlock(&client->buffer_lock);

	spin_unlock_irq(&input->event_lock);

	if (copy_to_user(buf, &data, sizeof(struct JS_DATA_TYPE)))
	return -EFAULT;

	return sizeof(struct JS_DATA_TYPE);
	}

	static inline int joydev_data_pending(struct joydev_client *client)
	{
	struct joydev *joydev = client->joydev;

	return client->startup < joydev->nabs + joydev->nkey \|\|
	client->head != client->tail;
	}

	static ssize_t joydev_read(struct file file, char __user buf,
	size_t count, loff_t *ppos)
	{
	struct joydev_client *client = file->private_data;
	struct joydev *joydev = client->joydev;
	struct input_dev *input = joydev->handle.dev;
	struct js_event event;
	int retval;

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

	if (count < sizeof(struct js_event))
	return -EINVAL;

	if (count == sizeof(struct JS_DATA_TYPE))
	return joydev_0x_read(client, input, buf);

	if (!joydev_data_pending(client) && (file->f_flags & O_NONBLOCK))
	return -EAGAIN;

	retval = wait_event_interruptible(joydev->wait,
	!joydev->exist \|\| joydev_data_pending(client));
	if (retval)
	return retval;

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

	while (retval + sizeof(struct js_event) <= count &&
	joydev_generate_startup_event(client, input, &event)) {

	if (copy_to_user(buf + retval, &event, sizeof(struct js_event)))
	return -EFAULT;

	retval += sizeof(struct js_event);
	}

	while (retval + sizeof(struct js_event) <= count &&
	joydev_fetch_next_event(client, &event)) {

	if (copy_to_user(buf + retval, &event, sizeof(struct js_event)))
	return -EFAULT;

	retval += sizeof(struct js_event);
	}

	return retval;
	}

	/* No kernel lock - fine */
	static unsigned int joydev_poll(struct file file, poll_table wait)
	{
	struct joydev_client *client = file->private_data;
	struct joydev *joydev = client->joydev;

	poll_wait(file, &joydev->wait, wait);
	return (joydev_data_pending(client) ? (POLLIN \| POLLRDNORM) : 0) \|
	(joydev->exist ? 0 : (POLLHUP \| POLLERR));
	}

	static int joydev_ioctl_common(struct joydev *joydev,
	unsigned int cmd, void __user *argp)
	{
	struct input_dev *dev = joydev->handle.dev;
	int i, j;

	switch (cmd) {

	case JS_SET_CAL:
	return copy_from_user(&joydev->glue.JS_CORR, argp,
	sizeof(joydev->glue.JS_CORR)) ? -EFAULT : 0;

	case JS_GET_CAL:
	return copy_to_user(argp, &joydev->glue.JS_CORR,
	sizeof(joydev->glue.JS_CORR)) ? -EFAULT : 0;

	case JS_SET_TIMEOUT:
	return get_user(joydev->glue.JS_TIMEOUT, (s32 __user *) argp);

	case JS_GET_TIMEOUT:
	return put_user(joydev->glue.JS_TIMEOUT, (s32 __user *) argp);

	case JSIOCGVERSION:
	return put_user(JS_VERSION, (__u32 __user *) argp);

	case JSIOCGAXES:
	return put_user(joydev->nabs, (__u8 __user *) argp);

	case JSIOCGBUTTONS:
	return put_user(joydev->nkey, (__u8 __user *) argp);

	case JSIOCSCORR:
	if (copy_from_user(joydev->corr, argp,
	sizeof(joydev->corr[0]) * joydev->nabs))
	return -EFAULT;

	for (i = 0; i < joydev->nabs; i++) {
	j = joydev->abspam[i];
	joydev->abs[i] = joydev_correct(dev->abs[j],
	&joydev->corr[i]);
	}
	return 0;

	case JSIOCGCORR:
	return copy_to_user(argp, joydev->corr,
	sizeof(joydev->corr[0]) * joydev->nabs) ? -EFAULT : 0;

	case JSIOCSAXMAP:
	if (copy_from_user(joydev->abspam, argp,
	sizeof(__u8) * (ABS_MAX + 1)))
	return -EFAULT;

	for (i = 0; i < joydev->nabs; i++) {
	if (joydev->abspam[i] > ABS_MAX)
	return -EINVAL;
	joydev->absmap[joydev->abspam[i]] = i;
	}
	return 0;

	case JSIOCGAXMAP:
	return copy_to_user(argp, joydev->abspam,
	sizeof(__u8) * (ABS_MAX + 1)) ? -EFAULT : 0;

	case JSIOCSBTNMAP:
	if (copy_from_user(joydev->keypam, argp,
	sizeof(__u16) * (KEY_MAX - BTN_MISC + 1)))
	return -EFAULT;

	for (i = 0; i < joydev->nkey; i++) {
	if (joydev->keypam[i] > KEY_MAX \|\|
	joydev->keypam[i] < BTN_MISC)
	return -EINVAL;
	joydev->keymap[joydev->keypam[i] - BTN_MISC] = i;
	}

	return 0;

	case JSIOCGBTNMAP:
	return copy_to_user(argp, joydev->keypam,
	sizeof(__u16) * (KEY_MAX - BTN_MISC + 1)) ? -EFAULT : 0;

	default:
	if ((cmd & ~IOCSIZE_MASK) == JSIOCGNAME(0)) {
	int len;
	if (!dev->name)
	return 0;
	len = strlen(dev->name) + 1;
	if (len > _IOC_SIZE(cmd))
	len = _IOC_SIZE(cmd);
	if (copy_to_user(argp, dev->name, len))
	return -EFAULT;
	return len;
	}
	}
	return -EINVAL;
	}

	#ifdef CONFIG_COMPAT
	static long joydev_compat_ioctl(struct file *file,
	unsigned int cmd, unsigned long arg)
	{
	struct joydev_client *client = file->private_data;
	struct joydev *joydev = client->joydev;
	void __user argp = (void __user )arg;
	s32 tmp32;
	struct JS_DATA_SAVE_TYPE_32 ds32;
	int retval;

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

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

	switch (cmd) {

	case JS_SET_TIMELIMIT:
	retval = get_user(tmp32, (s32 __user *) arg);
	if (retval == 0)
	joydev->glue.JS_TIMELIMIT = tmp32;
	break;

	case JS_GET_TIMELIMIT:
	tmp32 = joydev->glue.JS_TIMELIMIT;
	retval = put_user(tmp32, (s32 __user *) arg);
	break;

	case JS_SET_ALL:
	retval = copy_from_user(&ds32, argp,
	sizeof(ds32)) ? -EFAULT : 0;
	if (retval == 0) {
	joydev->glue.JS_TIMEOUT = ds32.JS_TIMEOUT;
	joydev->glue.BUSY = ds32.BUSY;
	joydev->glue.JS_EXPIRETIME = ds32.JS_EXPIRETIME;
	joydev->glue.JS_TIMELIMIT = ds32.JS_TIMELIMIT;
	joydev->glue.JS_SAVE = ds32.JS_SAVE;
	joydev->glue.JS_CORR = ds32.JS_CORR;
	}
	break;

	case JS_GET_ALL:
	ds32.JS_TIMEOUT = joydev->glue.JS_TIMEOUT;
	ds32.BUSY = joydev->glue.BUSY;
	ds32.JS_EXPIRETIME = joydev->glue.JS_EXPIRETIME;
	ds32.JS_TIMELIMIT = joydev->glue.JS_TIMELIMIT;
	ds32.JS_SAVE = joydev->glue.JS_SAVE;
	ds32.JS_CORR = joydev->glue.JS_CORR;

	retval = copy_to_user(argp, &ds32, sizeof(ds32)) ? -EFAULT : 0;
	break;

	default:
	retval = joydev_ioctl_common(joydev, cmd, argp);
	break;
	}

	out:
	mutex_unlock(&joydev->mutex);
	return retval;
	}
	#endif /* CONFIG_COMPAT */

	static long joydev_ioctl(struct file *file,
	unsigned int cmd, unsigned long arg)
	{
	struct joydev_client *client = file->private_data;
	struct joydev *joydev = client->joydev;
	void __user argp = (void __user )arg;
	int retval;

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

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

	switch (cmd) {

	case JS_SET_TIMELIMIT:
	retval = get_user(joydev->glue.JS_TIMELIMIT,
	(long __user *) arg);
	break;

	case JS_GET_TIMELIMIT:
	retval = put_user(joydev->glue.JS_TIMELIMIT,
	(long __user *) arg);
	break;

	case JS_SET_ALL:
	retval = copy_from_user(&joydev->glue, argp,
	sizeof(joydev->glue)) ? -EFAULT: 0;
	break;

	case JS_GET_ALL:
	retval = copy_to_user(argp, &joydev->glue,
	sizeof(joydev->glue)) ? -EFAULT : 0;
	break;

	default:
	retval = joydev_ioctl_common(joydev, cmd, argp);
	break;
	}
	out:
	mutex_unlock(&joydev->mutex);
	return retval;
	}

	static const struct file_operations joydev_fops = {
	.owner = THIS_MODULE,
	.read = joydev_read,
	.poll = joydev_poll,
	.open = joydev_open,
	.release = joydev_release,
	.unlocked_ioctl = joydev_ioctl,
	#ifdef CONFIG_COMPAT
	.compat_ioctl = joydev_compat_ioctl,
	#endif
	.fasync = joydev_fasync,
	};

	static int joydev_install_chrdev(struct joydev *joydev)
	{
	joydev_table[joydev->minor] = joydev;
	return 0;
	}

	static void joydev_remove_chrdev(struct joydev *joydev)
	{
	mutex_lock(&joydev_table_mutex);
	joydev_table[joydev->minor] = NULL;
	mutex_unlock(&joydev_table_mutex);
	}

	/*
	* Mark device non-existant. 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 joydev_mark_dead(struct joydev *joydev)
	{
	mutex_lock(&joydev->mutex);
	joydev->exist = 0;
	mutex_unlock(&joydev->mutex);
	}

	static void joydev_cleanup(struct joydev *joydev)
	{
	struct input_handle *handle = &joydev->handle;

	joydev_mark_dead(joydev);
	joydev_hangup(joydev);
	joydev_remove_chrdev(joydev);

	/* joydev is marked dead so noone else accesses joydev->open */
	if (joydev->open)
	input_close_device(handle);
	}

	static int joydev_connect(struct input_handler handler, struct input_dev dev,
	const struct input_device_id *id)
	{
	struct joydev *joydev;
	int i, j, t, minor;
	int error;

	for (minor = 0; minor < JOYDEV_MINORS; minor++)
	if (!joydev_table[minor])
	break;

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

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

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

	snprintf(joydev->name, sizeof(joydev->name), "js%d", minor);
	joydev->exist = 1;
	joydev->minor = minor;

	joydev->exist = 1;
	joydev->handle.dev = input_get_device(dev);
	joydev->handle.name = joydev->name;
	joydev->handle.handler = handler;
	joydev->handle.private = joydev;

	for (i = 0; i < ABS_MAX + 1; i++)
	if (test_bit(i, dev->absbit)) {
	joydev->absmap[i] = joydev->nabs;
	joydev->abspam[joydev->nabs] = i;
	joydev->nabs++;
	}

	for (i = BTN_JOYSTICK - BTN_MISC; i < KEY_MAX - BTN_MISC + 1; i++)
	if (test_bit(i + BTN_MISC, dev->keybit)) {
	joydev->keymap[i] = joydev->nkey;
	joydev->keypam[joydev->nkey] = i + BTN_MISC;
	joydev->nkey++;
	}

	for (i = 0; i < BTN_JOYSTICK - BTN_MISC; i++)
	if (test_bit(i + BTN_MISC, dev->keybit)) {
	joydev->keymap[i] = joydev->nkey;
	joydev->keypam[joydev->nkey] = i + BTN_MISC;
	joydev->nkey++;
	}

	for (i = 0; i < joydev->nabs; i++) {
	j = joydev->abspam[i];
	if (dev->absmax[j] == dev->absmin[j]) {
	joydev->corr[i].type = JS_CORR_NONE;
	joydev->abs[i] = dev->abs[j];
	continue;
	}
	joydev->corr[i].type = JS_CORR_BROKEN;
	joydev->corr[i].prec = dev->absfuzz[j];
	joydev->corr[i].coef[0] =
	(dev->absmax[j] + dev->absmin[j]) / 2 - dev->absflat[j];
	joydev->corr[i].coef[1] =
	(dev->absmax[j] + dev->absmin[j]) / 2 + dev->absflat[j];

	t = (dev->absmax[j] - dev->absmin[j]) / 2 - 2 * dev->absflat[j];
	if (t) {
	joydev->corr[i].coef[2] = (1 << 29) / t;
	joydev->corr[i].coef[3] = (1 << 29) / t;

	joydev->abs[i] = joydev_correct(dev->abs[j],
	joydev->corr + i);
	}
	}

	dev_set_name(&joydev->dev, joydev->name);
	joydev->dev.devt = MKDEV(INPUT_MAJOR, JOYDEV_MINOR_BASE + minor);
	joydev->dev.class = &input_class;
	joydev->dev.parent = &dev->dev;
	joydev->dev.release = joydev_free;
	device_initialize(&joydev->dev);

	error = input_register_handle(&joydev->handle);
	if (error)
	goto err_free_joydev;

	error = joydev_install_chrdev(joydev);
	if (error)
	goto err_unregister_handle;

	error = device_add(&joydev->dev);
	if (error)
	goto err_cleanup_joydev;

	return 0;

	err_cleanup_joydev:
	joydev_cleanup(joydev);
	err_unregister_handle:
	input_unregister_handle(&joydev->handle);
	err_free_joydev:
	put_device(&joydev->dev);
	return error;
	}

	static void joydev_disconnect(struct input_handle *handle)
	{
	struct joydev *joydev = handle->private;

	device_del(&joydev->dev);
	joydev_cleanup(joydev);
	input_unregister_handle(handle);
	put_device(&joydev->dev);
	}

	static const struct input_device_id joydev_blacklist[] = {
	{
	.flags = INPUT_DEVICE_ID_MATCH_EVBIT \|
	INPUT_DEVICE_ID_MATCH_KEYBIT,
	.evbit = { BIT_MASK(EV_KEY) },
	.keybit = { [BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH) },
	}, /* Avoid itouchpads and touchscreens */
	{
	.flags = INPUT_DEVICE_ID_MATCH_EVBIT \|
	INPUT_DEVICE_ID_MATCH_KEYBIT,
	.evbit = { BIT_MASK(EV_KEY) },
	.keybit = { [BIT_WORD(BTN_DIGI)] = BIT_MASK(BTN_DIGI) },
	}, /* Avoid tablets, digitisers and similar devices */
	{ } /* Terminating entry */
	};

	static const struct input_device_id joydev_ids[] = {
	{
	.flags = INPUT_DEVICE_ID_MATCH_EVBIT \|
	INPUT_DEVICE_ID_MATCH_ABSBIT,
	.evbit = { BIT_MASK(EV_ABS) },
	.absbit = { BIT_MASK(ABS_X) },
	},
	{
	.flags = INPUT_DEVICE_ID_MATCH_EVBIT \|
	INPUT_DEVICE_ID_MATCH_ABSBIT,
	.evbit = { BIT_MASK(EV_ABS) },
	.absbit = { BIT_MASK(ABS_WHEEL) },
	},
	{
	.flags = INPUT_DEVICE_ID_MATCH_EVBIT \|
	INPUT_DEVICE_ID_MATCH_ABSBIT,
	.evbit = { BIT_MASK(EV_ABS) },
	.absbit = { BIT_MASK(ABS_THROTTLE) },
	},
	{ } /* Terminating entry */
	};

	MODULE_DEVICE_TABLE(input, joydev_ids);

	static struct input_handler joydev_handler = {
	.event = joydev_event,
	.connect = joydev_connect,
	.disconnect = joydev_disconnect,
	.fops = &joydev_fops,
	.minor = JOYDEV_MINOR_BASE,
	.name = "joydev",
	.id_table = joydev_ids,
	.blacklist = joydev_blacklist,
	};

	static int __init joydev_init(void)
	{
	return input_register_handler(&joydev_handler);
	}

	static void __exit joydev_exit(void)
	{
	input_unregister_handler(&joydev_handler);
	}

	module_init(joydev_init);
	module_exit(joydev_exit);