Linux Audio

Check our new training course

Real-Time Linux with PREEMPT_RT training

Feb 18-20, 2025
Register
Loading...
v4.6
   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/miscdevice.h>
  26#include <linux/module.h>
  27#include <linux/poll.h>
  28#include <linux/init.h>
  29#include <linux/device.h>
  30#include <linux/cdev.h>
  31
  32MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
  33MODULE_DESCRIPTION("Joystick device interfaces");
  34MODULE_SUPPORTED_DEVICE("input/js");
  35MODULE_LICENSE("GPL");
  36
  37#define JOYDEV_MINOR_BASE	0
  38#define JOYDEV_MINORS		16
  39#define JOYDEV_BUFFER_SIZE	64
  40
  41struct joydev {
  42	int open;
  43	struct input_handle handle;
  44	wait_queue_head_t wait;
  45	struct list_head client_list;
  46	spinlock_t client_lock; /* protects client_list */
  47	struct mutex mutex;
  48	struct device dev;
  49	struct cdev cdev;
  50	bool exist;
  51
  52	struct js_corr corr[ABS_CNT];
  53	struct JS_DATA_SAVE_TYPE glue;
  54	int nabs;
  55	int nkey;
  56	__u16 keymap[KEY_MAX - BTN_MISC + 1];
  57	__u16 keypam[KEY_MAX - BTN_MISC + 1];
  58	__u8 absmap[ABS_CNT];
  59	__u8 abspam[ABS_CNT];
  60	__s16 abs[ABS_CNT];
  61};
  62
  63struct joydev_client {
  64	struct js_event buffer[JOYDEV_BUFFER_SIZE];
  65	int head;
  66	int tail;
  67	int startup;
  68	spinlock_t buffer_lock; /* protects access to buffer, head and tail */
  69	struct fasync_struct *fasync;
  70	struct joydev *joydev;
  71	struct list_head node;
  72};
  73
  74static int joydev_correct(int value, struct js_corr *corr)
  75{
  76	switch (corr->type) {
  77
  78	case JS_CORR_NONE:
  79		break;
  80
  81	case JS_CORR_BROKEN:
  82		value = value > corr->coef[0] ? (value < corr->coef[1] ? 0 :
  83			((corr->coef[3] * (value - corr->coef[1])) >> 14)) :
  84			((corr->coef[2] * (value - corr->coef[0])) >> 14);
  85		break;
  86
  87	default:
  88		return 0;
  89	}
  90
  91	return value < -32767 ? -32767 : (value > 32767 ? 32767 : value);
  92}
  93
  94static void joydev_pass_event(struct joydev_client *client,
  95			      struct js_event *event)
  96{
  97	struct joydev *joydev = client->joydev;
  98
  99	/*
 100	 * IRQs already disabled, just acquire the lock
 101	 */
 102	spin_lock(&client->buffer_lock);
 103
 104	client->buffer[client->head] = *event;
 105
 106	if (client->startup == joydev->nabs + joydev->nkey) {
 107		client->head++;
 108		client->head &= JOYDEV_BUFFER_SIZE - 1;
 109		if (client->tail == client->head)
 110			client->startup = 0;
 111	}
 112
 113	spin_unlock(&client->buffer_lock);
 114
 115	kill_fasync(&client->fasync, SIGIO, POLL_IN);
 116}
 117
 118static void joydev_event(struct input_handle *handle,
 119			 unsigned int type, unsigned int code, int value)
 120{
 121	struct joydev *joydev = handle->private;
 122	struct joydev_client *client;
 123	struct js_event event;
 124
 125	switch (type) {
 126
 127	case EV_KEY:
 128		if (code < BTN_MISC || value == 2)
 129			return;
 130		event.type = JS_EVENT_BUTTON;
 131		event.number = joydev->keymap[code - BTN_MISC];
 132		event.value = value;
 133		break;
 134
 135	case EV_ABS:
 136		event.type = JS_EVENT_AXIS;
 137		event.number = joydev->absmap[code];
 138		event.value = joydev_correct(value,
 139					&joydev->corr[event.number]);
 140		if (event.value == joydev->abs[event.number])
 141			return;
 142		joydev->abs[event.number] = event.value;
 143		break;
 144
 145	default:
 146		return;
 147	}
 148
 149	event.time = jiffies_to_msecs(jiffies);
 150
 151	rcu_read_lock();
 152	list_for_each_entry_rcu(client, &joydev->client_list, node)
 153		joydev_pass_event(client, &event);
 154	rcu_read_unlock();
 155
 156	wake_up_interruptible(&joydev->wait);
 157}
 158
 159static int joydev_fasync(int fd, struct file *file, int on)
 160{
 161	struct joydev_client *client = file->private_data;
 162
 163	return fasync_helper(fd, file, on, &client->fasync);
 164}
 165
 166static void joydev_free(struct device *dev)
 167{
 168	struct joydev *joydev = container_of(dev, struct joydev, dev);
 169
 170	input_put_device(joydev->handle.dev);
 171	kfree(joydev);
 172}
 173
 174static void joydev_attach_client(struct joydev *joydev,
 175				 struct joydev_client *client)
 176{
 177	spin_lock(&joydev->client_lock);
 178	list_add_tail_rcu(&client->node, &joydev->client_list);
 179	spin_unlock(&joydev->client_lock);
 180}
 181
 182static void joydev_detach_client(struct joydev *joydev,
 183				 struct joydev_client *client)
 184{
 185	spin_lock(&joydev->client_lock);
 186	list_del_rcu(&client->node);
 187	spin_unlock(&joydev->client_lock);
 188	synchronize_rcu();
 189}
 190
 191static int joydev_open_device(struct joydev *joydev)
 192{
 193	int retval;
 194
 195	retval = mutex_lock_interruptible(&joydev->mutex);
 196	if (retval)
 197		return retval;
 198
 199	if (!joydev->exist)
 200		retval = -ENODEV;
 201	else if (!joydev->open++) {
 202		retval = input_open_device(&joydev->handle);
 203		if (retval)
 204			joydev->open--;
 205	}
 206
 207	mutex_unlock(&joydev->mutex);
 208	return retval;
 209}
 210
 211static void joydev_close_device(struct joydev *joydev)
 212{
 213	mutex_lock(&joydev->mutex);
 214
 215	if (joydev->exist && !--joydev->open)
 216		input_close_device(&joydev->handle);
 217
 218	mutex_unlock(&joydev->mutex);
 219}
 220
 221/*
 222 * Wake up users waiting for IO so they can disconnect from
 223 * dead device.
 224 */
 225static void joydev_hangup(struct joydev *joydev)
 226{
 227	struct joydev_client *client;
 228
 229	spin_lock(&joydev->client_lock);
 230	list_for_each_entry(client, &joydev->client_list, node)
 231		kill_fasync(&client->fasync, SIGIO, POLL_HUP);
 232	spin_unlock(&joydev->client_lock);
 233
 234	wake_up_interruptible(&joydev->wait);
 235}
 236
 237static int joydev_release(struct inode *inode, struct file *file)
 238{
 239	struct joydev_client *client = file->private_data;
 240	struct joydev *joydev = client->joydev;
 241
 242	joydev_detach_client(joydev, client);
 243	kfree(client);
 244
 245	joydev_close_device(joydev);
 246
 247	return 0;
 248}
 249
 250static int joydev_open(struct inode *inode, struct file *file)
 251{
 252	struct joydev *joydev =
 253			container_of(inode->i_cdev, struct joydev, cdev);
 254	struct joydev_client *client;
 255	int error;
 256
 257	client = kzalloc(sizeof(struct joydev_client), GFP_KERNEL);
 258	if (!client)
 259		return -ENOMEM;
 260
 261	spin_lock_init(&client->buffer_lock);
 262	client->joydev = joydev;
 263	joydev_attach_client(joydev, client);
 264
 265	error = joydev_open_device(joydev);
 266	if (error)
 267		goto err_free_client;
 268
 269	file->private_data = client;
 270	nonseekable_open(inode, file);
 271
 272	return 0;
 273
 274 err_free_client:
 275	joydev_detach_client(joydev, client);
 276	kfree(client);
 277	return error;
 278}
 279
 280static int joydev_generate_startup_event(struct joydev_client *client,
 281					 struct input_dev *input,
 282					 struct js_event *event)
 283{
 284	struct joydev *joydev = client->joydev;
 285	int have_event;
 286
 287	spin_lock_irq(&client->buffer_lock);
 288
 289	have_event = client->startup < joydev->nabs + joydev->nkey;
 290
 291	if (have_event) {
 292
 293		event->time = jiffies_to_msecs(jiffies);
 294		if (client->startup < joydev->nkey) {
 295			event->type = JS_EVENT_BUTTON | JS_EVENT_INIT;
 296			event->number = client->startup;
 297			event->value = !!test_bit(joydev->keypam[event->number],
 298						  input->key);
 299		} else {
 300			event->type = JS_EVENT_AXIS | JS_EVENT_INIT;
 301			event->number = client->startup - joydev->nkey;
 302			event->value = joydev->abs[event->number];
 303		}
 304		client->startup++;
 305	}
 306
 307	spin_unlock_irq(&client->buffer_lock);
 308
 309	return have_event;
 310}
 311
 312static int joydev_fetch_next_event(struct joydev_client *client,
 313				   struct js_event *event)
 314{
 315	int have_event;
 316
 317	spin_lock_irq(&client->buffer_lock);
 318
 319	have_event = client->head != client->tail;
 320	if (have_event) {
 321		*event = client->buffer[client->tail++];
 322		client->tail &= JOYDEV_BUFFER_SIZE - 1;
 323	}
 324
 325	spin_unlock_irq(&client->buffer_lock);
 326
 327	return have_event;
 328}
 329
 330/*
 331 * Old joystick interface
 332 */
 333static ssize_t joydev_0x_read(struct joydev_client *client,
 334			      struct input_dev *input,
 335			      char __user *buf)
 336{
 337	struct joydev *joydev = client->joydev;
 338	struct JS_DATA_TYPE data;
 339	int i;
 340
 341	spin_lock_irq(&input->event_lock);
 342
 343	/*
 344	 * Get device state
 345	 */
 346	for (data.buttons = i = 0; i < 32 && i < joydev->nkey; i++)
 347		data.buttons |=
 348			test_bit(joydev->keypam[i], input->key) ? (1 << i) : 0;
 349	data.x = (joydev->abs[0] / 256 + 128) >> joydev->glue.JS_CORR.x;
 350	data.y = (joydev->abs[1] / 256 + 128) >> joydev->glue.JS_CORR.y;
 351
 352	/*
 353	 * Reset reader's event queue
 354	 */
 355	spin_lock(&client->buffer_lock);
 356	client->startup = 0;
 357	client->tail = client->head;
 358	spin_unlock(&client->buffer_lock);
 359
 360	spin_unlock_irq(&input->event_lock);
 361
 362	if (copy_to_user(buf, &data, sizeof(struct JS_DATA_TYPE)))
 363		return -EFAULT;
 364
 365	return sizeof(struct JS_DATA_TYPE);
 366}
 367
 368static inline int joydev_data_pending(struct joydev_client *client)
 369{
 370	struct joydev *joydev = client->joydev;
 371
 372	return client->startup < joydev->nabs + joydev->nkey ||
 373		client->head != client->tail;
 374}
 375
 376static ssize_t joydev_read(struct file *file, char __user *buf,
 377			   size_t count, loff_t *ppos)
 378{
 379	struct joydev_client *client = file->private_data;
 380	struct joydev *joydev = client->joydev;
 381	struct input_dev *input = joydev->handle.dev;
 382	struct js_event event;
 383	int retval;
 384
 385	if (!joydev->exist)
 386		return -ENODEV;
 387
 388	if (count < sizeof(struct js_event))
 389		return -EINVAL;
 390
 391	if (count == sizeof(struct JS_DATA_TYPE))
 392		return joydev_0x_read(client, input, buf);
 393
 394	if (!joydev_data_pending(client) && (file->f_flags & O_NONBLOCK))
 395		return -EAGAIN;
 396
 397	retval = wait_event_interruptible(joydev->wait,
 398			!joydev->exist || joydev_data_pending(client));
 399	if (retval)
 400		return retval;
 401
 402	if (!joydev->exist)
 403		return -ENODEV;
 404
 405	while (retval + sizeof(struct js_event) <= count &&
 406	       joydev_generate_startup_event(client, input, &event)) {
 407
 408		if (copy_to_user(buf + retval, &event, sizeof(struct js_event)))
 409			return -EFAULT;
 410
 411		retval += sizeof(struct js_event);
 412	}
 413
 414	while (retval + sizeof(struct js_event) <= count &&
 415	       joydev_fetch_next_event(client, &event)) {
 416
 417		if (copy_to_user(buf + retval, &event, sizeof(struct js_event)))
 418			return -EFAULT;
 419
 420		retval += sizeof(struct js_event);
 421	}
 422
 423	return retval;
 424}
 425
 426/* No kernel lock - fine */
 427static unsigned int joydev_poll(struct file *file, poll_table *wait)
 428{
 429	struct joydev_client *client = file->private_data;
 430	struct joydev *joydev = client->joydev;
 431
 432	poll_wait(file, &joydev->wait, wait);
 433	return (joydev_data_pending(client) ? (POLLIN | POLLRDNORM) : 0) |
 434		(joydev->exist ?  0 : (POLLHUP | POLLERR));
 435}
 436
 437static int joydev_handle_JSIOCSAXMAP(struct joydev *joydev,
 438				     void __user *argp, size_t len)
 439{
 440	__u8 *abspam;
 441	int i;
 442	int retval = 0;
 443
 444	len = min(len, sizeof(joydev->abspam));
 445
 446	/* Validate the map. */
 447	abspam = memdup_user(argp, len);
 448	if (IS_ERR(abspam))
 449		return PTR_ERR(abspam);
 450
 451	for (i = 0; i < joydev->nabs; i++) {
 452		if (abspam[i] > ABS_MAX) {
 453			retval = -EINVAL;
 454			goto out;
 455		}
 456	}
 457
 458	memcpy(joydev->abspam, abspam, len);
 459
 460	for (i = 0; i < joydev->nabs; i++)
 461		joydev->absmap[joydev->abspam[i]] = i;
 462
 463 out:
 464	kfree(abspam);
 465	return retval;
 466}
 467
 468static int joydev_handle_JSIOCSBTNMAP(struct joydev *joydev,
 469				      void __user *argp, size_t len)
 470{
 471	__u16 *keypam;
 472	int i;
 473	int retval = 0;
 474
 475	len = min(len, sizeof(joydev->keypam));
 476
 477	/* Validate the map. */
 478	keypam = memdup_user(argp, len);
 479	if (IS_ERR(keypam))
 480		return PTR_ERR(keypam);
 481
 482	for (i = 0; i < joydev->nkey; i++) {
 483		if (keypam[i] > KEY_MAX || keypam[i] < BTN_MISC) {
 484			retval = -EINVAL;
 485			goto out;
 486		}
 487	}
 488
 489	memcpy(joydev->keypam, keypam, len);
 490
 491	for (i = 0; i < joydev->nkey; i++)
 492		joydev->keymap[keypam[i] - BTN_MISC] = i;
 493
 494 out:
 495	kfree(keypam);
 496	return retval;
 497}
 498
 499
 500static int joydev_ioctl_common(struct joydev *joydev,
 501				unsigned int cmd, void __user *argp)
 502{
 503	struct input_dev *dev = joydev->handle.dev;
 504	size_t len;
 505	int i;
 506	const char *name;
 507
 508	/* Process fixed-sized commands. */
 509	switch (cmd) {
 510
 511	case JS_SET_CAL:
 512		return copy_from_user(&joydev->glue.JS_CORR, argp,
 513				sizeof(joydev->glue.JS_CORR)) ? -EFAULT : 0;
 514
 515	case JS_GET_CAL:
 516		return copy_to_user(argp, &joydev->glue.JS_CORR,
 517				sizeof(joydev->glue.JS_CORR)) ? -EFAULT : 0;
 518
 519	case JS_SET_TIMEOUT:
 520		return get_user(joydev->glue.JS_TIMEOUT, (s32 __user *) argp);
 521
 522	case JS_GET_TIMEOUT:
 523		return put_user(joydev->glue.JS_TIMEOUT, (s32 __user *) argp);
 524
 525	case JSIOCGVERSION:
 526		return put_user(JS_VERSION, (__u32 __user *) argp);
 527
 528	case JSIOCGAXES:
 529		return put_user(joydev->nabs, (__u8 __user *) argp);
 530
 531	case JSIOCGBUTTONS:
 532		return put_user(joydev->nkey, (__u8 __user *) argp);
 533
 534	case JSIOCSCORR:
 535		if (copy_from_user(joydev->corr, argp,
 536			      sizeof(joydev->corr[0]) * joydev->nabs))
 537			return -EFAULT;
 538
 539		for (i = 0; i < joydev->nabs; i++) {
 540			int val = input_abs_get_val(dev, joydev->abspam[i]);
 541			joydev->abs[i] = joydev_correct(val, &joydev->corr[i]);
 542		}
 543		return 0;
 544
 545	case JSIOCGCORR:
 546		return copy_to_user(argp, joydev->corr,
 547			sizeof(joydev->corr[0]) * joydev->nabs) ? -EFAULT : 0;
 548
 549	}
 550
 551	/*
 552	 * Process variable-sized commands (the axis and button map commands
 553	 * are considered variable-sized to decouple them from the values of
 554	 * ABS_MAX and KEY_MAX).
 555	 */
 556	switch (cmd & ~IOCSIZE_MASK) {
 557
 558	case (JSIOCSAXMAP & ~IOCSIZE_MASK):
 559		return joydev_handle_JSIOCSAXMAP(joydev, argp, _IOC_SIZE(cmd));
 560
 561	case (JSIOCGAXMAP & ~IOCSIZE_MASK):
 562		len = min_t(size_t, _IOC_SIZE(cmd), sizeof(joydev->abspam));
 563		return copy_to_user(argp, joydev->abspam, len) ? -EFAULT : len;
 564
 565	case (JSIOCSBTNMAP & ~IOCSIZE_MASK):
 566		return joydev_handle_JSIOCSBTNMAP(joydev, argp, _IOC_SIZE(cmd));
 567
 568	case (JSIOCGBTNMAP & ~IOCSIZE_MASK):
 569		len = min_t(size_t, _IOC_SIZE(cmd), sizeof(joydev->keypam));
 570		return copy_to_user(argp, joydev->keypam, len) ? -EFAULT : len;
 571
 572	case JSIOCGNAME(0):
 573		name = dev->name;
 574		if (!name)
 575			return 0;
 576
 577		len = min_t(size_t, _IOC_SIZE(cmd), strlen(name) + 1);
 578		return copy_to_user(argp, name, len) ? -EFAULT : len;
 579	}
 580
 581	return -EINVAL;
 582}
 583
 584#ifdef CONFIG_COMPAT
 585static long joydev_compat_ioctl(struct file *file,
 586				unsigned int cmd, unsigned long arg)
 587{
 588	struct joydev_client *client = file->private_data;
 589	struct joydev *joydev = client->joydev;
 590	void __user *argp = (void __user *)arg;
 591	s32 tmp32;
 592	struct JS_DATA_SAVE_TYPE_32 ds32;
 593	int retval;
 594
 595	retval = mutex_lock_interruptible(&joydev->mutex);
 596	if (retval)
 597		return retval;
 598
 599	if (!joydev->exist) {
 600		retval = -ENODEV;
 601		goto out;
 602	}
 603
 604	switch (cmd) {
 605
 606	case JS_SET_TIMELIMIT:
 607		retval = get_user(tmp32, (s32 __user *) arg);
 608		if (retval == 0)
 609			joydev->glue.JS_TIMELIMIT = tmp32;
 610		break;
 611
 612	case JS_GET_TIMELIMIT:
 613		tmp32 = joydev->glue.JS_TIMELIMIT;
 614		retval = put_user(tmp32, (s32 __user *) arg);
 615		break;
 616
 617	case JS_SET_ALL:
 618		retval = copy_from_user(&ds32, argp,
 619					sizeof(ds32)) ? -EFAULT : 0;
 620		if (retval == 0) {
 621			joydev->glue.JS_TIMEOUT    = ds32.JS_TIMEOUT;
 622			joydev->glue.BUSY          = ds32.BUSY;
 623			joydev->glue.JS_EXPIRETIME = ds32.JS_EXPIRETIME;
 624			joydev->glue.JS_TIMELIMIT  = ds32.JS_TIMELIMIT;
 625			joydev->glue.JS_SAVE       = ds32.JS_SAVE;
 626			joydev->glue.JS_CORR       = ds32.JS_CORR;
 627		}
 628		break;
 629
 630	case JS_GET_ALL:
 631		ds32.JS_TIMEOUT    = joydev->glue.JS_TIMEOUT;
 632		ds32.BUSY          = joydev->glue.BUSY;
 633		ds32.JS_EXPIRETIME = joydev->glue.JS_EXPIRETIME;
 634		ds32.JS_TIMELIMIT  = joydev->glue.JS_TIMELIMIT;
 635		ds32.JS_SAVE       = joydev->glue.JS_SAVE;
 636		ds32.JS_CORR       = joydev->glue.JS_CORR;
 637
 638		retval = copy_to_user(argp, &ds32, sizeof(ds32)) ? -EFAULT : 0;
 639		break;
 640
 641	default:
 642		retval = joydev_ioctl_common(joydev, cmd, argp);
 643		break;
 644	}
 645
 646 out:
 647	mutex_unlock(&joydev->mutex);
 648	return retval;
 649}
 650#endif /* CONFIG_COMPAT */
 651
 652static long joydev_ioctl(struct file *file,
 653			 unsigned int cmd, unsigned long arg)
 654{
 655	struct joydev_client *client = file->private_data;
 656	struct joydev *joydev = client->joydev;
 657	void __user *argp = (void __user *)arg;
 658	int retval;
 659
 660	retval = mutex_lock_interruptible(&joydev->mutex);
 661	if (retval)
 662		return retval;
 663
 664	if (!joydev->exist) {
 665		retval = -ENODEV;
 666		goto out;
 667	}
 668
 669	switch (cmd) {
 670
 671	case JS_SET_TIMELIMIT:
 672		retval = get_user(joydev->glue.JS_TIMELIMIT,
 673				  (long __user *) arg);
 674		break;
 675
 676	case JS_GET_TIMELIMIT:
 677		retval = put_user(joydev->glue.JS_TIMELIMIT,
 678				  (long __user *) arg);
 679		break;
 680
 681	case JS_SET_ALL:
 682		retval = copy_from_user(&joydev->glue, argp,
 683					sizeof(joydev->glue)) ? -EFAULT : 0;
 684		break;
 685
 686	case JS_GET_ALL:
 687		retval = copy_to_user(argp, &joydev->glue,
 688				      sizeof(joydev->glue)) ? -EFAULT : 0;
 689		break;
 690
 691	default:
 692		retval = joydev_ioctl_common(joydev, cmd, argp);
 693		break;
 694	}
 695 out:
 696	mutex_unlock(&joydev->mutex);
 697	return retval;
 698}
 699
 700static const struct file_operations joydev_fops = {
 701	.owner		= THIS_MODULE,
 702	.read		= joydev_read,
 703	.poll		= joydev_poll,
 704	.open		= joydev_open,
 705	.release	= joydev_release,
 706	.unlocked_ioctl	= joydev_ioctl,
 707#ifdef CONFIG_COMPAT
 708	.compat_ioctl	= joydev_compat_ioctl,
 709#endif
 710	.fasync		= joydev_fasync,
 711	.llseek		= no_llseek,
 712};
 713
 714/*
 715 * Mark device non-existent. This disables writes, ioctls and
 716 * prevents new users from opening the device. Already posted
 717 * blocking reads will stay, however new ones will fail.
 718 */
 719static void joydev_mark_dead(struct joydev *joydev)
 720{
 721	mutex_lock(&joydev->mutex);
 722	joydev->exist = false;
 723	mutex_unlock(&joydev->mutex);
 724}
 725
 726static void joydev_cleanup(struct joydev *joydev)
 727{
 728	struct input_handle *handle = &joydev->handle;
 729
 730	joydev_mark_dead(joydev);
 731	joydev_hangup(joydev);
 732
 733	cdev_del(&joydev->cdev);
 734
 735	/* joydev is marked dead so no one else accesses joydev->open */
 736	if (joydev->open)
 737		input_close_device(handle);
 738}
 739
 740static bool joydev_dev_is_absolute_mouse(struct input_dev *dev)
 741{
 742	DECLARE_BITMAP(jd_scratch, KEY_CNT);
 743
 744	BUILD_BUG_ON(ABS_CNT > KEY_CNT || EV_CNT > KEY_CNT);
 745
 746	/*
 747	 * Virtualization (VMware, etc) and remote management (HP
 748	 * ILO2) solutions use absolute coordinates for their virtual
 749	 * pointing devices so that there is one-to-one relationship
 750	 * between pointer position on the host screen and virtual
 751	 * guest screen, and so their mice use ABS_X, ABS_Y and 3
 752	 * primary button events. This clashes with what joydev
 753	 * considers to be joysticks (a device with at minimum ABS_X
 754	 * axis).
 755	 *
 756	 * Here we are trying to separate absolute mice from
 757	 * joysticks. A device is, for joystick detection purposes,
 758	 * considered to be an absolute mouse if the following is
 759	 * true:
 760	 *
 761	 * 1) Event types are exactly EV_ABS, EV_KEY and EV_SYN.
 762	 * 2) Absolute events are exactly ABS_X and ABS_Y.
 763	 * 3) Keys are exactly BTN_LEFT, BTN_RIGHT and BTN_MIDDLE.
 764	 * 4) Device is not on "Amiga" bus.
 765	 */
 766
 767	bitmap_zero(jd_scratch, EV_CNT);
 768	__set_bit(EV_ABS, jd_scratch);
 769	__set_bit(EV_KEY, jd_scratch);
 770	__set_bit(EV_SYN, jd_scratch);
 771	if (!bitmap_equal(jd_scratch, dev->evbit, EV_CNT))
 772		return false;
 773
 774	bitmap_zero(jd_scratch, ABS_CNT);
 775	__set_bit(ABS_X, jd_scratch);
 776	__set_bit(ABS_Y, jd_scratch);
 777	if (!bitmap_equal(dev->absbit, jd_scratch, ABS_CNT))
 778		return false;
 779
 780	bitmap_zero(jd_scratch, KEY_CNT);
 781	__set_bit(BTN_LEFT, jd_scratch);
 782	__set_bit(BTN_RIGHT, jd_scratch);
 783	__set_bit(BTN_MIDDLE, jd_scratch);
 784
 785	if (!bitmap_equal(dev->keybit, jd_scratch, KEY_CNT))
 786		return false;
 787
 788	/*
 789	 * Amiga joystick (amijoy) historically uses left/middle/right
 790	 * button events.
 791	 */
 792	if (dev->id.bustype == BUS_AMIGA)
 793		return false;
 794
 795	return true;
 796}
 797
 798static bool joydev_match(struct input_handler *handler, struct input_dev *dev)
 799{
 800	/* Avoid touchpads and touchscreens */
 801	if (test_bit(EV_KEY, dev->evbit) && test_bit(BTN_TOUCH, dev->keybit))
 802		return false;
 803
 804	/* Avoid tablets, digitisers and similar devices */
 805	if (test_bit(EV_KEY, dev->evbit) && test_bit(BTN_DIGI, dev->keybit))
 806		return false;
 807
 808	/* Avoid absolute mice */
 809	if (joydev_dev_is_absolute_mouse(dev))
 810		return false;
 811
 812	return true;
 813}
 814
 815static int joydev_connect(struct input_handler *handler, struct input_dev *dev,
 816			  const struct input_device_id *id)
 817{
 818	struct joydev *joydev;
 819	int i, j, t, minor, dev_no;
 820	int error;
 821
 822	minor = input_get_new_minor(JOYDEV_MINOR_BASE, JOYDEV_MINORS, true);
 823	if (minor < 0) {
 824		error = minor;
 825		pr_err("failed to reserve new minor: %d\n", error);
 826		return error;
 827	}
 828
 829	joydev = kzalloc(sizeof(struct joydev), GFP_KERNEL);
 830	if (!joydev) {
 831		error = -ENOMEM;
 832		goto err_free_minor;
 833	}
 834
 835	INIT_LIST_HEAD(&joydev->client_list);
 836	spin_lock_init(&joydev->client_lock);
 837	mutex_init(&joydev->mutex);
 838	init_waitqueue_head(&joydev->wait);
 839	joydev->exist = true;
 840
 841	dev_no = minor;
 842	/* Normalize device number if it falls into legacy range */
 843	if (dev_no < JOYDEV_MINOR_BASE + JOYDEV_MINORS)
 844		dev_no -= JOYDEV_MINOR_BASE;
 845	dev_set_name(&joydev->dev, "js%d", dev_no);
 846
 847	joydev->handle.dev = input_get_device(dev);
 848	joydev->handle.name = dev_name(&joydev->dev);
 849	joydev->handle.handler = handler;
 850	joydev->handle.private = joydev;
 851
 852	for_each_set_bit(i, dev->absbit, ABS_CNT) {
 853		joydev->absmap[i] = joydev->nabs;
 854		joydev->abspam[joydev->nabs] = i;
 855		joydev->nabs++;
 856	}
 857
 858	for (i = BTN_JOYSTICK - BTN_MISC; i < KEY_MAX - BTN_MISC + 1; i++)
 859		if (test_bit(i + BTN_MISC, dev->keybit)) {
 860			joydev->keymap[i] = joydev->nkey;
 861			joydev->keypam[joydev->nkey] = i + BTN_MISC;
 862			joydev->nkey++;
 863		}
 864
 865	for (i = 0; i < BTN_JOYSTICK - BTN_MISC; i++)
 866		if (test_bit(i + BTN_MISC, dev->keybit)) {
 867			joydev->keymap[i] = joydev->nkey;
 868			joydev->keypam[joydev->nkey] = i + BTN_MISC;
 869			joydev->nkey++;
 870		}
 871
 872	for (i = 0; i < joydev->nabs; i++) {
 873		j = joydev->abspam[i];
 874		if (input_abs_get_max(dev, j) == input_abs_get_min(dev, j)) {
 875			joydev->corr[i].type = JS_CORR_NONE;
 876			joydev->abs[i] = input_abs_get_val(dev, j);
 877			continue;
 878		}
 879		joydev->corr[i].type = JS_CORR_BROKEN;
 880		joydev->corr[i].prec = input_abs_get_fuzz(dev, j);
 881
 882		t = (input_abs_get_max(dev, j) + input_abs_get_min(dev, j)) / 2;
 883		joydev->corr[i].coef[0] = t - input_abs_get_flat(dev, j);
 884		joydev->corr[i].coef[1] = t + input_abs_get_flat(dev, j);
 885
 886		t = (input_abs_get_max(dev, j) - input_abs_get_min(dev, j)) / 2
 887			- 2 * input_abs_get_flat(dev, j);
 888		if (t) {
 889			joydev->corr[i].coef[2] = (1 << 29) / t;
 890			joydev->corr[i].coef[3] = (1 << 29) / t;
 891
 892			joydev->abs[i] =
 893				joydev_correct(input_abs_get_val(dev, j),
 894					       joydev->corr + i);
 895		}
 896	}
 897
 898	joydev->dev.devt = MKDEV(INPUT_MAJOR, minor);
 899	joydev->dev.class = &input_class;
 900	joydev->dev.parent = &dev->dev;
 901	joydev->dev.release = joydev_free;
 902	device_initialize(&joydev->dev);
 903
 904	error = input_register_handle(&joydev->handle);
 905	if (error)
 906		goto err_free_joydev;
 907
 908	cdev_init(&joydev->cdev, &joydev_fops);
 909	joydev->cdev.kobj.parent = &joydev->dev.kobj;
 910	error = cdev_add(&joydev->cdev, joydev->dev.devt, 1);
 911	if (error)
 912		goto err_unregister_handle;
 913
 914	error = device_add(&joydev->dev);
 915	if (error)
 916		goto err_cleanup_joydev;
 917
 918	return 0;
 919
 920 err_cleanup_joydev:
 921	joydev_cleanup(joydev);
 922 err_unregister_handle:
 923	input_unregister_handle(&joydev->handle);
 924 err_free_joydev:
 925	put_device(&joydev->dev);
 926 err_free_minor:
 927	input_free_minor(minor);
 928	return error;
 929}
 930
 931static void joydev_disconnect(struct input_handle *handle)
 932{
 933	struct joydev *joydev = handle->private;
 934
 935	device_del(&joydev->dev);
 936	joydev_cleanup(joydev);
 937	input_free_minor(MINOR(joydev->dev.devt));
 938	input_unregister_handle(handle);
 939	put_device(&joydev->dev);
 940}
 941
 942static const struct input_device_id joydev_ids[] = {
 943	{
 944		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 945				INPUT_DEVICE_ID_MATCH_ABSBIT,
 946		.evbit = { BIT_MASK(EV_ABS) },
 947		.absbit = { BIT_MASK(ABS_X) },
 
 
 
 
 
 
 948	},
 949	{
 950		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 951				INPUT_DEVICE_ID_MATCH_ABSBIT,
 952		.evbit = { BIT_MASK(EV_ABS) },
 953		.absbit = { BIT_MASK(ABS_WHEEL) },
 954	},
 955	{
 956		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 957				INPUT_DEVICE_ID_MATCH_ABSBIT,
 958		.evbit = { BIT_MASK(EV_ABS) },
 959		.absbit = { BIT_MASK(ABS_THROTTLE) },
 960	},
 961	{
 962		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 963				INPUT_DEVICE_ID_MATCH_KEYBIT,
 964		.evbit = { BIT_MASK(EV_KEY) },
 965		.keybit = {[BIT_WORD(BTN_JOYSTICK)] = BIT_MASK(BTN_JOYSTICK) },
 966	},
 967	{
 968		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 969				INPUT_DEVICE_ID_MATCH_KEYBIT,
 970		.evbit = { BIT_MASK(EV_KEY) },
 971		.keybit = { [BIT_WORD(BTN_GAMEPAD)] = BIT_MASK(BTN_GAMEPAD) },
 972	},
 973	{
 974		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
 975				INPUT_DEVICE_ID_MATCH_KEYBIT,
 976		.evbit = { BIT_MASK(EV_KEY) },
 977		.keybit = { [BIT_WORD(BTN_TRIGGER_HAPPY)] = BIT_MASK(BTN_TRIGGER_HAPPY) },
 978	},
 979	{ }	/* Terminating entry */
 980};
 981
 982MODULE_DEVICE_TABLE(input, joydev_ids);
 983
 984static struct input_handler joydev_handler = {
 985	.event		= joydev_event,
 986	.match		= joydev_match,
 987	.connect	= joydev_connect,
 988	.disconnect	= joydev_disconnect,
 989	.legacy_minors	= true,
 990	.minor		= JOYDEV_MINOR_BASE,
 991	.name		= "joydev",
 992	.id_table	= joydev_ids,
 993};
 994
 995static int __init joydev_init(void)
 996{
 997	return input_register_handler(&joydev_handler);
 998}
 999
1000static void __exit joydev_exit(void)
1001{
1002	input_unregister_handler(&joydev_handler);
1003}
1004
1005module_init(joydev_init);
1006module_exit(joydev_exit);
v4.10.11
   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);