1/*
   2 * Joystick device driver for the input driver suite.
   3 *
   4 * Copyright (c) 1999-2002 Vojtech Pavlik
   5 * Copyright (c) 1999 Colin Van Dyke
   6 *
   7 * This program is free software; you can redistribute it and/or modify
   8 * it under the terms of the GNU General Public License as published by
   9 * the Free Software Foundation; either version 2 of the License, or
  10 * (at your option) any later version.
  11 */
  12
  13#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  14
  15#include <asm/io.h>
  16#include <linux/delay.h>
  17#include <linux/errno.h>
  18#include <linux/joystick.h>
  19#include <linux/input.h>
  20#include <linux/kernel.h>
  21#include <linux/major.h>
  22#include <linux/sched.h>
  23#include <linux/slab.h>
  24#include <linux/mm.h>
 
  25#include <linux/module.h>
  26#include <linux/poll.h>
  27#include <linux/init.h>
  28#include <linux/device.h>
  29#include <linux/cdev.h>
  30
  31MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
  32MODULE_DESCRIPTION("Joystick device interfaces");
  33MODULE_SUPPORTED_DEVICE("input/js");
  34MODULE_LICENSE("GPL");
  35
  36#define JOYDEV_MINOR_BASE	0
  37#define JOYDEV_MINORS		16
  38#define JOYDEV_BUFFER_SIZE	64
  39
  40struct joydev {
  41	int open;
 
  42	struct input_handle handle;
  43	wait_queue_head_t wait;
  44	struct list_head client_list;
  45	spinlock_t client_lock; /* protects client_list */
  46	struct mutex mutex;
  47	struct device dev;
  48	struct cdev cdev;
  49	bool exist;
  50
  51	struct js_corr corr[ABS_CNT];
  52	struct JS_DATA_SAVE_TYPE glue;
  53	int nabs;
  54	int nkey;
  55	__u16 keymap[KEY_MAX - BTN_MISC + 1];
  56	__u16 keypam[KEY_MAX - BTN_MISC + 1];
  57	__u8 absmap[ABS_CNT];
  58	__u8 abspam[ABS_CNT];
  59	__s16 abs[ABS_CNT];
  60};
  61
  62struct joydev_client {
  63	struct js_event buffer[JOYDEV_BUFFER_SIZE];
  64	int head;
  65	int tail;
  66	int startup;
  67	spinlock_t buffer_lock; /* protects access to buffer, head and tail */
  68	struct fasync_struct *fasync;
  69	struct joydev *joydev;
  70	struct list_head node;
  71};
  72
 
 
 
  73static int joydev_correct(int value, struct js_corr *corr)
  74{
  75	switch (corr->type) {
  76
  77	case JS_CORR_NONE:
  78		break;
  79
  80	case JS_CORR_BROKEN:
  81		value = value > corr->coef[0] ? (value < corr->coef[1] ? 0 :
  82			((corr->coef[3] * (value - corr->coef[1])) >> 14)) :
  83			((corr->coef[2] * (value - corr->coef[0])) >> 14);
  84		break;
  85
  86	default:
  87		return 0;
  88	}
  89
  90	return value < -32767 ? -32767 : (value > 32767 ? 32767 : value);
  91}
  92
  93static void joydev_pass_event(struct joydev_client *client,
  94			      struct js_event *event)
  95{
  96	struct joydev *joydev = client->joydev;
  97
  98	/*
  99	 * IRQs already disabled, just acquire the lock
 100	 */
 101	spin_lock(&client->buffer_lock);
 102
 103	client->buffer[client->head] = *event;
 104
 105	if (client->startup == joydev->nabs + joydev->nkey) {
 106		client->head++;
 107		client->head &= JOYDEV_BUFFER_SIZE - 1;
 108		if (client->tail == client->head)
 109			client->startup = 0;
 110	}
 111
 112	spin_unlock(&client->buffer_lock);
 113
 114	kill_fasync(&client->fasync, SIGIO, POLL_IN);
 115}
 116
 117static void joydev_event(struct input_handle *handle,
 118			 unsigned int type, unsigned int code, int value)
 119{
 120	struct joydev *joydev = handle->private;
 121	struct joydev_client *client;
 122	struct js_event event;
 123
 124	switch (type) {
 125
 126	case EV_KEY:
 127		if (code < BTN_MISC || value == 2)
 128			return;
 129		event.type = JS_EVENT_BUTTON;
 130		event.number = joydev->keymap[code - BTN_MISC];
 131		event.value = value;
 132		break;
 133
 134	case EV_ABS:
 135		event.type = JS_EVENT_AXIS;
 136		event.number = joydev->absmap[code];
 137		event.value = joydev_correct(value,
 138					&joydev->corr[event.number]);
 139		if (event.value == joydev->abs[event.number])
 140			return;
 141		joydev->abs[event.number] = event.value;
 142		break;
 143
 144	default:
 145		return;
 146	}
 147
 148	event.time = jiffies_to_msecs(jiffies);
 149
 150	rcu_read_lock();
 151	list_for_each_entry_rcu(client, &joydev->client_list, node)
 152		joydev_pass_event(client, &event);
 153	rcu_read_unlock();
 154
 155	wake_up_interruptible(&joydev->wait);
 156}
 157
 158static int joydev_fasync(int fd, struct file *file, int on)
 159{
 160	struct joydev_client *client = file->private_data;
 161
 162	return fasync_helper(fd, file, on, &client->fasync);
 163}
 164
 165static void joydev_free(struct device *dev)
 166{
 167	struct joydev *joydev = container_of(dev, struct joydev, dev);
 168
 169	input_put_device(joydev->handle.dev);
 170	kfree(joydev);
 171}
 172
 173static void joydev_attach_client(struct joydev *joydev,
 174				 struct joydev_client *client)
 175{
 176	spin_lock(&joydev->client_lock);
 177	list_add_tail_rcu(&client->node, &joydev->client_list);
 178	spin_unlock(&joydev->client_lock);
 179}
 180
 181static void joydev_detach_client(struct joydev *joydev,
 182				 struct joydev_client *client)
 183{
 184	spin_lock(&joydev->client_lock);
 185	list_del_rcu(&client->node);
 186	spin_unlock(&joydev->client_lock);
 187	synchronize_rcu();
 188}
 189
 190static int joydev_open_device(struct joydev *joydev)
 191{
 192	int retval;
 193
 194	retval = mutex_lock_interruptible(&joydev->mutex);
 195	if (retval)
 196		return retval;
 197
 198	if (!joydev->exist)
 199		retval = -ENODEV;
 200	else if (!joydev->open++) {
 201		retval = input_open_device(&joydev->handle);
 202		if (retval)
 203			joydev->open--;
 204	}
 205
 206	mutex_unlock(&joydev->mutex);
 207	return retval;
 208}
 209
 210static void joydev_close_device(struct joydev *joydev)
 211{
 212	mutex_lock(&joydev->mutex);
 213
 214	if (joydev->exist && !--joydev->open)
 215		input_close_device(&joydev->handle);
 216
 217	mutex_unlock(&joydev->mutex);
 218}
 219
 220/*
 221 * Wake up users waiting for IO so they can disconnect from
 222 * dead device.
 223 */
 224static void joydev_hangup(struct joydev *joydev)
 225{
 226	struct joydev_client *client;
 227
 228	spin_lock(&joydev->client_lock);
 229	list_for_each_entry(client, &joydev->client_list, node)
 230		kill_fasync(&client->fasync, SIGIO, POLL_HUP);
 231	spin_unlock(&joydev->client_lock);
 232
 233	wake_up_interruptible(&joydev->wait);
 234}
 235
 236static int joydev_release(struct inode *inode, struct file *file)
 237{
 238	struct joydev_client *client = file->private_data;
 239	struct joydev *joydev = client->joydev;
 240
 241	joydev_detach_client(joydev, client);
 242	kfree(client);
 243
 244	joydev_close_device(joydev);
 
 245
 246	return 0;
 247}
 248
 249static int joydev_open(struct inode *inode, struct file *file)
 250{
 251	struct joydev *joydev =
 252			container_of(inode->i_cdev, struct joydev, cdev);
 253	struct joydev_client *client;
 
 
 254	int error;
 255
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 256	client = kzalloc(sizeof(struct joydev_client), GFP_KERNEL);
 257	if (!client)
 258		return -ENOMEM;
 
 
 259
 260	spin_lock_init(&client->buffer_lock);
 261	client->joydev = joydev;
 262	joydev_attach_client(joydev, client);
 263
 264	error = joydev_open_device(joydev);
 265	if (error)
 266		goto err_free_client;
 267
 268	file->private_data = client;
 269	nonseekable_open(inode, file);
 270
 271	return 0;
 272
 273 err_free_client:
 274	joydev_detach_client(joydev, client);
 275	kfree(client);
 
 
 276	return error;
 277}
 278
 279static int joydev_generate_startup_event(struct joydev_client *client,
 280					 struct input_dev *input,
 281					 struct js_event *event)
 282{
 283	struct joydev *joydev = client->joydev;
 284	int have_event;
 285
 286	spin_lock_irq(&client->buffer_lock);
 287
 288	have_event = client->startup < joydev->nabs + joydev->nkey;
 289
 290	if (have_event) {
 291
 292		event->time = jiffies_to_msecs(jiffies);
 293		if (client->startup < joydev->nkey) {
 294			event->type = JS_EVENT_BUTTON | JS_EVENT_INIT;
 295			event->number = client->startup;
 296			event->value = !!test_bit(joydev->keypam[event->number],
 297						  input->key);
 298		} else {
 299			event->type = JS_EVENT_AXIS | JS_EVENT_INIT;
 300			event->number = client->startup - joydev->nkey;
 301			event->value = joydev->abs[event->number];
 302		}
 303		client->startup++;
 304	}
 305
 306	spin_unlock_irq(&client->buffer_lock);
 307
 308	return have_event;
 309}
 310
 311static int joydev_fetch_next_event(struct joydev_client *client,
 312				   struct js_event *event)
 313{
 314	int have_event;
 315
 316	spin_lock_irq(&client->buffer_lock);
 317
 318	have_event = client->head != client->tail;
 319	if (have_event) {
 320		*event = client->buffer[client->tail++];
 321		client->tail &= JOYDEV_BUFFER_SIZE - 1;
 322	}
 323
 324	spin_unlock_irq(&client->buffer_lock);
 325
 326	return have_event;
 327}
 328
 329/*
 330 * Old joystick interface
 331 */
 332static ssize_t joydev_0x_read(struct joydev_client *client,
 333			      struct input_dev *input,
 334			      char __user *buf)
 335{
 336	struct joydev *joydev = client->joydev;
 337	struct JS_DATA_TYPE data;
 338	int i;
 339
 340	spin_lock_irq(&input->event_lock);
 341
 342	/*
 343	 * Get device state
 344	 */
 345	for (data.buttons = i = 0; i < 32 && i < joydev->nkey; i++)
 346		data.buttons |=
 347			test_bit(joydev->keypam[i], input->key) ? (1 << i) : 0;
 348	data.x = (joydev->abs[0] / 256 + 128) >> joydev->glue.JS_CORR.x;
 349	data.y = (joydev->abs[1] / 256 + 128) >> joydev->glue.JS_CORR.y;
 350
 351	/*
 352	 * Reset reader's event queue
 353	 */
 354	spin_lock(&client->buffer_lock);
 355	client->startup = 0;
 356	client->tail = client->head;
 357	spin_unlock(&client->buffer_lock);
 358
 359	spin_unlock_irq(&input->event_lock);
 360
 361	if (copy_to_user(buf, &data, sizeof(struct JS_DATA_TYPE)))
 362		return -EFAULT;
 363
 364	return sizeof(struct JS_DATA_TYPE);
 365}
 366
 367static inline int joydev_data_pending(struct joydev_client *client)
 368{
 369	struct joydev *joydev = client->joydev;
 370
 371	return client->startup < joydev->nabs + joydev->nkey ||
 372		client->head != client->tail;
 373}
 374
 375static ssize_t joydev_read(struct file *file, char __user *buf,
 376			   size_t count, loff_t *ppos)
 377{
 378	struct joydev_client *client = file->private_data;
 379	struct joydev *joydev = client->joydev;
 380	struct input_dev *input = joydev->handle.dev;
 381	struct js_event event;
 382	int retval;
 383
 384	if (!joydev->exist)
 385		return -ENODEV;
 386
 387	if (count < sizeof(struct js_event))
 388		return -EINVAL;
 389
 390	if (count == sizeof(struct JS_DATA_TYPE))
 391		return joydev_0x_read(client, input, buf);
 392
 393	if (!joydev_data_pending(client) && (file->f_flags & O_NONBLOCK))
 394		return -EAGAIN;
 395
 396	retval = wait_event_interruptible(joydev->wait,
 397			!joydev->exist || joydev_data_pending(client));
 398	if (retval)
 399		return retval;
 400
 401	if (!joydev->exist)
 402		return -ENODEV;
 403
 404	while (retval + sizeof(struct js_event) <= count &&
 405	       joydev_generate_startup_event(client, input, &event)) {
 406
 407		if (copy_to_user(buf + retval, &event, sizeof(struct js_event)))
 408			return -EFAULT;
 409
 410		retval += sizeof(struct js_event);
 411	}
 412
 413	while (retval + sizeof(struct js_event) <= count &&
 414	       joydev_fetch_next_event(client, &event)) {
 415
 416		if (copy_to_user(buf + retval, &event, sizeof(struct js_event)))
 417			return -EFAULT;
 418
 419		retval += sizeof(struct js_event);
 420	}
 421
 422	return retval;
 423}
 424
 425/* No kernel lock - fine */
 426static unsigned int joydev_poll(struct file *file, poll_table *wait)
 427{
 428	struct joydev_client *client = file->private_data;
 429	struct joydev *joydev = client->joydev;
 430
 431	poll_wait(file, &joydev->wait, wait);
 432	return (joydev_data_pending(client) ? (POLLIN | POLLRDNORM) : 0) |
 433		(joydev->exist ?  0 : (POLLHUP | POLLERR));
 434}
 435
 436static int joydev_handle_JSIOCSAXMAP(struct joydev *joydev,
 437				     void __user *argp, size_t len)
 438{
 439	__u8 *abspam;
 440	int i;
 441	int retval = 0;
 442
 443	len = min(len, sizeof(joydev->abspam));
 444
 445	/* Validate the map. */
 446	abspam = memdup_user(argp, len);
 447	if (IS_ERR(abspam))
 448		return PTR_ERR(abspam);
 
 
 
 
 
 449
 450	for (i = 0; i < joydev->nabs; i++) {
 451		if (abspam[i] > ABS_MAX) {
 452			retval = -EINVAL;
 453			goto out;
 454		}
 455	}
 456
 457	memcpy(joydev->abspam, abspam, len);
 458
 459	for (i = 0; i < joydev->nabs; i++)
 460		joydev->absmap[joydev->abspam[i]] = i;
 461
 462 out:
 463	kfree(abspam);
 464	return retval;
 465}
 466
 467static int joydev_handle_JSIOCSBTNMAP(struct joydev *joydev,
 468				      void __user *argp, size_t len)
 469{
 470	__u16 *keypam;
 471	int i;
 472	int retval = 0;
 473
 474	len = min(len, sizeof(joydev->keypam));
 475
 476	/* Validate the map. */
 477	keypam = memdup_user(argp, len);
 478	if (IS_ERR(keypam))
 479		return PTR_ERR(keypam);
 
 
 
 
 
 480
 481	for (i = 0; i < joydev->nkey; i++) {
 482		if (keypam[i] > KEY_MAX || keypam[i] < BTN_MISC) {
 483			retval = -EINVAL;
 484			goto out;
 485		}
 486	}
 487
 488	memcpy(joydev->keypam, keypam, len);
 489
 490	for (i = 0; i < joydev->nkey; i++)
 491		joydev->keymap[keypam[i] - BTN_MISC] = i;
 492
 493 out:
 494	kfree(keypam);
 495	return retval;
 496}
 497
 498
 499static int joydev_ioctl_common(struct joydev *joydev,
 500				unsigned int cmd, void __user *argp)
 501{
 502	struct input_dev *dev = joydev->handle.dev;
 503	size_t len;
 504	int i;
 505	const char *name;
 506
 507	/* Process fixed-sized commands. */
 508	switch (cmd) {
 509
 510	case JS_SET_CAL:
 511		return copy_from_user(&joydev->glue.JS_CORR, argp,
 512				sizeof(joydev->glue.JS_CORR)) ? -EFAULT : 0;
 513
 514	case JS_GET_CAL:
 515		return copy_to_user(argp, &joydev->glue.JS_CORR,
 516				sizeof(joydev->glue.JS_CORR)) ? -EFAULT : 0;
 517
 518	case JS_SET_TIMEOUT:
 519		return get_user(joydev->glue.JS_TIMEOUT, (s32 __user *) argp);
 520
 521	case JS_GET_TIMEOUT:
 522		return put_user(joydev->glue.JS_TIMEOUT, (s32 __user *) argp);
 523
 524	case JSIOCGVERSION:
 525		return put_user(JS_VERSION, (__u32 __user *) argp);
 526
 527	case JSIOCGAXES:
 528		return put_user(joydev->nabs, (__u8 __user *) argp);
 529
 530	case JSIOCGBUTTONS:
 531		return put_user(joydev->nkey, (__u8 __user *) argp);
 532
 533	case JSIOCSCORR:
 534		if (copy_from_user(joydev->corr, argp,
 535			      sizeof(joydev->corr[0]) * joydev->nabs))
 536			return -EFAULT;
 537
 538		for (i = 0; i < joydev->nabs; i++) {
 539			int val = input_abs_get_val(dev, joydev->abspam[i]);
 540			joydev->abs[i] = joydev_correct(val, &joydev->corr[i]);
 541		}
 542		return 0;
 543
 544	case JSIOCGCORR:
 545		return copy_to_user(argp, joydev->corr,
 546			sizeof(joydev->corr[0]) * joydev->nabs) ? -EFAULT : 0;
 547
 548	}
 549
 550	/*
 551	 * Process variable-sized commands (the axis and button map commands
 552	 * are considered variable-sized to decouple them from the values of
 553	 * ABS_MAX and KEY_MAX).
 554	 */
 555	switch (cmd & ~IOCSIZE_MASK) {
 556
 557	case (JSIOCSAXMAP & ~IOCSIZE_MASK):
 558		return joydev_handle_JSIOCSAXMAP(joydev, argp, _IOC_SIZE(cmd));
 559
 560	case (JSIOCGAXMAP & ~IOCSIZE_MASK):
 561		len = min_t(size_t, _IOC_SIZE(cmd), sizeof(joydev->abspam));
 562		return copy_to_user(argp, joydev->abspam, len) ? -EFAULT : len;
 563
 564	case (JSIOCSBTNMAP & ~IOCSIZE_MASK):
 565		return joydev_handle_JSIOCSBTNMAP(joydev, argp, _IOC_SIZE(cmd));
 566
 567	case (JSIOCGBTNMAP & ~IOCSIZE_MASK):
 568		len = min_t(size_t, _IOC_SIZE(cmd), sizeof(joydev->keypam));
 569		return copy_to_user(argp, joydev->keypam, len) ? -EFAULT : len;
 570
 571	case JSIOCGNAME(0):
 572		name = dev->name;
 573		if (!name)
 574			return 0;
 575
 576		len = min_t(size_t, _IOC_SIZE(cmd), strlen(name) + 1);
 577		return copy_to_user(argp, name, len) ? -EFAULT : len;
 578	}
 579
 580	return -EINVAL;
 581}
 582
 583#ifdef CONFIG_COMPAT
 584static long joydev_compat_ioctl(struct file *file,
 585				unsigned int cmd, unsigned long arg)
 586{
 587	struct joydev_client *client = file->private_data;
 588	struct joydev *joydev = client->joydev;
 589	void __user *argp = (void __user *)arg;
 590	s32 tmp32;
 591	struct JS_DATA_SAVE_TYPE_32 ds32;
 592	int retval;
 593
 594	retval = mutex_lock_interruptible(&joydev->mutex);
 595	if (retval)
 596		return retval;
 597
 598	if (!joydev->exist) {
 599		retval = -ENODEV;
 600		goto out;
 601	}
 602
 603	switch (cmd) {
 604
 605	case JS_SET_TIMELIMIT:
 606		retval = get_user(tmp32, (s32 __user *) arg);
 607		if (retval == 0)
 608			joydev->glue.JS_TIMELIMIT = tmp32;
 609		break;
 610
 611	case JS_GET_TIMELIMIT:
 612		tmp32 = joydev->glue.JS_TIMELIMIT;
 613		retval = put_user(tmp32, (s32 __user *) arg);
 614		break;
 615
 616	case JS_SET_ALL:
 617		retval = copy_from_user(&ds32, argp,
 618					sizeof(ds32)) ? -EFAULT : 0;
 619		if (retval == 0) {
 620			joydev->glue.JS_TIMEOUT    = ds32.JS_TIMEOUT;
 621			joydev->glue.BUSY          = ds32.BUSY;
 622			joydev->glue.JS_EXPIRETIME = ds32.JS_EXPIRETIME;
 623			joydev->glue.JS_TIMELIMIT  = ds32.JS_TIMELIMIT;
 624			joydev->glue.JS_SAVE       = ds32.JS_SAVE;
 625			joydev->glue.JS_CORR       = ds32.JS_CORR;
 626		}
 627		break;
 628
 629	case JS_GET_ALL:
 630		ds32.JS_TIMEOUT    = joydev->glue.JS_TIMEOUT;
 631		ds32.BUSY          = joydev->glue.BUSY;
 632		ds32.JS_EXPIRETIME = joydev->glue.JS_EXPIRETIME;
 633		ds32.JS_TIMELIMIT  = joydev->glue.JS_TIMELIMIT;
 634		ds32.JS_SAVE       = joydev->glue.JS_SAVE;
 635		ds32.JS_CORR       = joydev->glue.JS_CORR;
 636
 637		retval = copy_to_user(argp, &ds32, sizeof(ds32)) ? -EFAULT : 0;
 638		break;
 639
 640	default:
 641		retval = joydev_ioctl_common(joydev, cmd, argp);
 642		break;
 643	}
 644
 645 out:
 646	mutex_unlock(&joydev->mutex);
 647	return retval;
 648}
 649#endif /* CONFIG_COMPAT */
 650
 651static long joydev_ioctl(struct file *file,
 652			 unsigned int cmd, unsigned long arg)
 653{
 654	struct joydev_client *client = file->private_data;
 655	struct joydev *joydev = client->joydev;
 656	void __user *argp = (void __user *)arg;
 657	int retval;
 658
 659	retval = mutex_lock_interruptible(&joydev->mutex);
 660	if (retval)
 661		return retval;
 662
 663	if (!joydev->exist) {
 664		retval = -ENODEV;
 665		goto out;
 666	}
 667
 668	switch (cmd) {
 669
 670	case JS_SET_TIMELIMIT:
 671		retval = get_user(joydev->glue.JS_TIMELIMIT,
 672				  (long __user *) arg);
 673		break;
 674
 675	case JS_GET_TIMELIMIT:
 676		retval = put_user(joydev->glue.JS_TIMELIMIT,
 677				  (long __user *) arg);
 678		break;
 679
 680	case JS_SET_ALL:
 681		retval = copy_from_user(&joydev->glue, argp,
 682					sizeof(joydev->glue)) ? -EFAULT : 0;
 683		break;
 684
 685	case JS_GET_ALL:
 686		retval = copy_to_user(argp, &joydev->glue,
 687				      sizeof(joydev->glue)) ? -EFAULT : 0;
 688		break;
 689
 690	default:
 691		retval = joydev_ioctl_common(joydev, cmd, argp);
 692		break;
 693	}
 694 out:
 695	mutex_unlock(&joydev->mutex);
 696	return retval;
 697}
 698
 699static const struct file_operations joydev_fops = {
 700	.owner		= THIS_MODULE,
 701	.read		= joydev_read,
 702	.poll		= joydev_poll,
 703	.open		= joydev_open,
 704	.release	= joydev_release,
 705	.unlocked_ioctl	= joydev_ioctl,
 706#ifdef CONFIG_COMPAT
 707	.compat_ioctl	= joydev_compat_ioctl,
 708#endif
 709	.fasync		= joydev_fasync,
 710	.llseek		= no_llseek,
 711};
 712
 
 
 
 
 
 
 
 
 
 
 
 
 
 713/*
 714 * Mark device non-existent. This disables writes, ioctls and
 715 * prevents new users from opening the device. Already posted
 716 * blocking reads will stay, however new ones will fail.
 717 */
 718static void joydev_mark_dead(struct joydev *joydev)
 719{
 720	mutex_lock(&joydev->mutex);
 721	joydev->exist = false;
 722	mutex_unlock(&joydev->mutex);
 723}
 724
 725static void joydev_cleanup(struct joydev *joydev)
 726{
 727	struct input_handle *handle = &joydev->handle;
 728
 729	joydev_mark_dead(joydev);
 730	joydev_hangup(joydev);
 731
 732	cdev_del(&joydev->cdev);
 733
 734	/* joydev is marked dead so no one else accesses joydev->open */
 735	if (joydev->open)
 736		input_close_device(handle);
 737}
 738
 739static bool joydev_dev_is_absolute_mouse(struct input_dev *dev)
 740{
 741	DECLARE_BITMAP(jd_scratch, KEY_CNT);
 742
 743	BUILD_BUG_ON(ABS_CNT > KEY_CNT || EV_CNT > KEY_CNT);
 744
 745	/*
 746	 * Virtualization (VMware, etc) and remote management (HP
 747	 * ILO2) solutions use absolute coordinates for their virtual
 748	 * pointing devices so that there is one-to-one relationship
 749	 * between pointer position on the host screen and virtual
 750	 * guest screen, and so their mice use ABS_X, ABS_Y and 3
 751	 * primary button events. This clashes with what joydev
 752	 * considers to be joysticks (a device with at minimum ABS_X
 753	 * axis).
 754	 *
 755	 * Here we are trying to separate absolute mice from
 756	 * joysticks. A device is, for joystick detection purposes,
 757	 * considered to be an absolute mouse if the following is
 758	 * true:
 759	 *
 760	 * 1) Event types are exactly EV_ABS, EV_KEY and EV_SYN.
 761	 * 2) Absolute events are exactly ABS_X and ABS_Y.
 762	 * 3) Keys are exactly BTN_LEFT, BTN_RIGHT and BTN_MIDDLE.
 763	 * 4) Device is not on "Amiga" bus.
 764	 */
 765
 766	bitmap_zero(jd_scratch, EV_CNT);
 767	__set_bit(EV_ABS, jd_scratch);
 768	__set_bit(EV_KEY, jd_scratch);
 769	__set_bit(EV_SYN, jd_scratch);
 770	if (!bitmap_equal(jd_scratch, dev->evbit, EV_CNT))
 771		return false;
 772
 773	bitmap_zero(jd_scratch, ABS_CNT);
 774	__set_bit(ABS_X, jd_scratch);
 775	__set_bit(ABS_Y, jd_scratch);
 776	if (!bitmap_equal(dev->absbit, jd_scratch, ABS_CNT))
 777		return false;
 778
 779	bitmap_zero(jd_scratch, KEY_CNT);
 780	__set_bit(BTN_LEFT, jd_scratch);
 781	__set_bit(BTN_RIGHT, jd_scratch);
 782	__set_bit(BTN_MIDDLE, jd_scratch);
 783
 784	if (!bitmap_equal(dev->keybit, jd_scratch, KEY_CNT))
 785		return false;
 786
 787	/*
 788	 * Amiga joystick (amijoy) historically uses left/middle/right
 789	 * button events.
 790	 */
 791	if (dev->id.bustype == BUS_AMIGA)
 792		return false;
 793
 794	return true;
 795}
 796
 797static bool joydev_match(struct input_handler *handler, struct input_dev *dev)
 798{
 799	/* Avoid touchpads and touchscreens */
 800	if (test_bit(EV_KEY, dev->evbit) && test_bit(BTN_TOUCH, dev->keybit))
 801		return false;
 802
 803	/* Avoid tablets, digitisers and similar devices */
 804	if (test_bit(EV_KEY, dev->evbit) && test_bit(BTN_DIGI, dev->keybit))
 805		return false;
 806
 807	/* Avoid absolute mice */
 808	if (joydev_dev_is_absolute_mouse(dev))
 809		return false;
 810
 811	return true;
 812}
 813
 814static int joydev_connect(struct input_handler *handler, struct input_dev *dev,
 815			  const struct input_device_id *id)
 816{
 817	struct joydev *joydev;
 818	int i, j, t, minor, dev_no;
 819	int error;
 820
 821	minor = input_get_new_minor(JOYDEV_MINOR_BASE, JOYDEV_MINORS, true);
 822	if (minor < 0) {
 823		error = minor;
 824		pr_err("failed to reserve new minor: %d\n", error);
 825		return error;
 
 
 826	}
 827
 828	joydev = kzalloc(sizeof(struct joydev), GFP_KERNEL);
 829	if (!joydev) {
 830		error = -ENOMEM;
 831		goto err_free_minor;
 832	}
 833
 834	INIT_LIST_HEAD(&joydev->client_list);
 835	spin_lock_init(&joydev->client_lock);
 836	mutex_init(&joydev->mutex);
 837	init_waitqueue_head(&joydev->wait);
 838	joydev->exist = true;
 839
 840	dev_no = minor;
 841	/* Normalize device number if it falls into legacy range */
 842	if (dev_no < JOYDEV_MINOR_BASE + JOYDEV_MINORS)
 843		dev_no -= JOYDEV_MINOR_BASE;
 844	dev_set_name(&joydev->dev, "js%d", dev_no);
 845
 846	joydev->handle.dev = input_get_device(dev);
 847	joydev->handle.name = dev_name(&joydev->dev);
 848	joydev->handle.handler = handler;
 849	joydev->handle.private = joydev;
 850
 851	for_each_set_bit(i, dev->absbit, ABS_CNT) {
 852		joydev->absmap[i] = joydev->nabs;
 853		joydev->abspam[joydev->nabs] = i;
 854		joydev->nabs++;
 855	}
 
 856
 857	for (i = BTN_JOYSTICK - BTN_MISC; i < KEY_MAX - BTN_MISC + 1; i++)
 858		if (test_bit(i + BTN_MISC, dev->keybit)) {
 859			joydev->keymap[i] = joydev->nkey;
 860			joydev->keypam[joydev->nkey] = i + BTN_MISC;
 861			joydev->nkey++;
 862		}
 863
 864	for (i = 0; i < BTN_JOYSTICK - BTN_MISC; i++)
 865		if (test_bit(i + BTN_MISC, dev->keybit)) {
 866			joydev->keymap[i] = joydev->nkey;
 867			joydev->keypam[joydev->nkey] = i + BTN_MISC;
 868			joydev->nkey++;
 869		}
 870
 871	for (i = 0; i < joydev->nabs; i++) {
 872		j = joydev->abspam[i];
 873		if (input_abs_get_max(dev, j) == input_abs_get_min(dev, j)) {
 874			joydev->corr[i].type = JS_CORR_NONE;
 875			joydev->abs[i] = input_abs_get_val(dev, j);
 876			continue;
 877		}
 878		joydev->corr[i].type = JS_CORR_BROKEN;
 879		joydev->corr[i].prec = input_abs_get_fuzz(dev, j);
 880
 881		t = (input_abs_get_max(dev, j) + input_abs_get_min(dev, j)) / 2;
 882		joydev->corr[i].coef[0] = t - input_abs_get_flat(dev, j);
 883		joydev->corr[i].coef[1] = t + input_abs_get_flat(dev, j);
 884
 885		t = (input_abs_get_max(dev, j) - input_abs_get_min(dev, j)) / 2
 886			- 2 * input_abs_get_flat(dev, j);
 887		if (t) {
 888			joydev->corr[i].coef[2] = (1 << 29) / t;
 889			joydev->corr[i].coef[3] = (1 << 29) / t;
 890
 891			joydev->abs[i] =
 892				joydev_correct(input_abs_get_val(dev, j),
 893					       joydev->corr + i);
 894		}
 895	}
 896
 897	joydev->dev.devt = MKDEV(INPUT_MAJOR, minor);
 898	joydev->dev.class = &input_class;
 899	joydev->dev.parent = &dev->dev;
 900	joydev->dev.release = joydev_free;
 901	device_initialize(&joydev->dev);
 902
 903	error = input_register_handle(&joydev->handle);
 904	if (error)
 905		goto err_free_joydev;
 906
 907	cdev_init(&joydev->cdev, &joydev_fops);
 908	joydev->cdev.kobj.parent = &joydev->dev.kobj;
 909	error = cdev_add(&joydev->cdev, joydev->dev.devt, 1);
 910	if (error)
 911		goto err_unregister_handle;
 912
 913	error = device_add(&joydev->dev);
 914	if (error)
 915		goto err_cleanup_joydev;
 916
 917	return 0;
 918
 919 err_cleanup_joydev:
 920	joydev_cleanup(joydev);
 921 err_unregister_handle:
 922	input_unregister_handle(&joydev->handle);
 923 err_free_joydev:
 924	put_device(&joydev->dev);
 925 err_free_minor:
 926	input_free_minor(minor);
 927	return error;
 928}
 929
 930static void joydev_disconnect(struct input_handle *handle)
 931{
 932	struct joydev *joydev = handle->private;
 933
 934	device_del(&joydev->dev);
 935	joydev_cleanup(joydev);
 936	input_free_minor(MINOR(joydev->dev.devt));
 937	input_unregister_handle(handle);
 938	put_device(&joydev->dev);
 939}
 940
 941static const struct input_device_id joydev_ids[] = {
 942	{
 943		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 944				INPUT_DEVICE_ID_MATCH_ABSBIT,
 945		.evbit = { BIT_MASK(EV_ABS) },
 946		.absbit = { BIT_MASK(ABS_X) },
 947	},
 948	{
 949		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 950				INPUT_DEVICE_ID_MATCH_ABSBIT,
 951		.evbit = { BIT_MASK(EV_ABS) },
 952		.absbit = { BIT_MASK(ABS_Z) },
 953	},
 954	{
 955		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 956				INPUT_DEVICE_ID_MATCH_ABSBIT,
 957		.evbit = { BIT_MASK(EV_ABS) },
 958		.absbit = { BIT_MASK(ABS_WHEEL) },
 959	},
 960	{
 961		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 962				INPUT_DEVICE_ID_MATCH_ABSBIT,
 963		.evbit = { BIT_MASK(EV_ABS) },
 964		.absbit = { BIT_MASK(ABS_THROTTLE) },
 965	},
 966	{
 967		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 968				INPUT_DEVICE_ID_MATCH_KEYBIT,
 969		.evbit = { BIT_MASK(EV_KEY) },
 970		.keybit = {[BIT_WORD(BTN_JOYSTICK)] = BIT_MASK(BTN_JOYSTICK) },
 971	},
 972	{
 973		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 974				INPUT_DEVICE_ID_MATCH_KEYBIT,
 975		.evbit = { BIT_MASK(EV_KEY) },
 976		.keybit = { [BIT_WORD(BTN_GAMEPAD)] = BIT_MASK(BTN_GAMEPAD) },
 977	},
 978	{
 979		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 980				INPUT_DEVICE_ID_MATCH_KEYBIT,
 981		.evbit = { BIT_MASK(EV_KEY) },
 982		.keybit = { [BIT_WORD(BTN_TRIGGER_HAPPY)] = BIT_MASK(BTN_TRIGGER_HAPPY) },
 983	},
 984	{ }	/* Terminating entry */
 985};
 986
 987MODULE_DEVICE_TABLE(input, joydev_ids);
 988
 989static struct input_handler joydev_handler = {
 990	.event		= joydev_event,
 991	.match		= joydev_match,
 992	.connect	= joydev_connect,
 993	.disconnect	= joydev_disconnect,
 994	.legacy_minors	= true,
 995	.minor		= JOYDEV_MINOR_BASE,
 996	.name		= "joydev",
 997	.id_table	= joydev_ids,
 998};
 999
1000static int __init joydev_init(void)
1001{
1002	return input_register_handler(&joydev_handler);
1003}
1004
1005static void __exit joydev_exit(void)
1006{
1007	input_unregister_handler(&joydev_handler);
1008}
1009
1010module_init(joydev_init);
1011module_exit(joydev_exit);