drivers/input/evdev.c

   1 /*
   2  * Event char devices, giving access to raw input device events.
   3  *
   4  * Copyright (c) 1999-2002 Vojtech Pavlik
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License version 2 as published by
   8  * the Free Software Foundation.
   9  */
  10
  11 #define EVDEV_MINOR_BASE        64
  12 #define EVDEV_MINORS            32
  13 #define EVDEV_BUFFER_SIZE       64
  14
  15 #include <linux/poll.h>
  16 #include <linux/slab.h>
  17 #include <linux/module.h>
  18 #include <linux/init.h>
  19 #include <linux/input.h>
  20 #include <linux/major.h>
  21 #include <linux/smp_lock.h>
  22 #include <linux/device.h>
  23 #include <linux/devfs_fs_kernel.h>
  24
  25 struct evdev {
  26         int exist;
  27         int open;
  28         int minor;
  29         char name[16];
  30         struct input_handle handle;
  31         wait_queue_head_t wait;
  32         struct evdev_list *grab;
  33         struct list_head list;
  34 };
  35
  36 struct evdev_list {
  37         struct input_event buffer[EVDEV_BUFFER_SIZE];
  38         int head;
  39         int tail;
  40         struct fasync_struct *fasync;
  41         struct evdev *evdev;
  42         struct list_head node;
  43 };
  44
  45 static struct evdev *evdev_table[EVDEV_MINORS];
  46
  47 static void evdev_event(struct input_handle *handle, unsigned int type, unsigned int code, int value)
  48 {
  49         struct evdev *evdev = handle->private;
  50         struct evdev_list *list;
  51
  52         if (evdev->grab) {
  53                 list = evdev->grab;
  54
  55                 do_gettimeofday(&list->buffer[list->head].time);
  56                 list->buffer[list->head].type = type;
  57                 list->buffer[list->head].code = code;
  58                 list->buffer[list->head].value = value;
  59                 list->head = (list->head + 1) & (EVDEV_BUFFER_SIZE - 1);
  60
  61                 kill_fasync(&list->fasync, SIGIO, POLL_IN);
  62         } else
  63                 list_for_each_entry(list, &evdev->list, node) {
  64
  65                         do_gettimeofday(&list->buffer[list->head].time);
  66                         list->buffer[list->head].type = type;
  67                         list->buffer[list->head].code = code;
  68                         list->buffer[list->head].value = value;
  69                         list->head = (list->head + 1) & (EVDEV_BUFFER_SIZE - 1);
  70
  71                         kill_fasync(&list->fasync, SIGIO, POLL_IN);
  72                 }
  73
  74         wake_up_interruptible(&evdev->wait);
  75 }
  76
  77 static int evdev_fasync(int fd, struct file *file, int on)
  78 {
  79         int retval;
  80         struct evdev_list *list = file->private_data;
  81         retval = fasync_helper(fd, file, on, &list->fasync);
  82         return retval < 0 ? retval : 0;
  83 }
  84
  85 static int evdev_flush(struct file * file)
  86 {
  87         struct evdev_list *list = file->private_data;
  88         if (!list->evdev->exist) return -ENODEV;
  89         return input_flush_device(&list->evdev->handle, file);
  90 }
  91
  92 static void evdev_free(struct evdev *evdev)
  93 {
  94         evdev_table[evdev->minor] = NULL;
  95         kfree(evdev);
  96 }
  97
  98 static int evdev_release(struct inode * inode, struct file * file)
  99 {
 100         struct evdev_list *list = file->private_data;
 101
 102         if (list->evdev->grab == list) {
 103                 input_release_device(&list->evdev->handle);
 104                 list->evdev->grab = NULL;
 105         }
 106
 107         evdev_fasync(-1, file, 0);
 108         list_del(&list->node);
 109
 110         if (!--list->evdev->open) {
 111                 if (list->evdev->exist)
 112                         input_close_device(&list->evdev->handle);
 113                 else
 114                         evdev_free(list->evdev);
 115         }
 116
 117         kfree(list);
 118         return 0;
 119 }
 120
 121 static int evdev_open(struct inode * inode, struct file * file)
 122 {
 123         struct evdev_list *list;
 124         int i = iminor(inode) - EVDEV_MINOR_BASE;
 125         int accept_err;
 126
 127         if (i >= EVDEV_MINORS || !evdev_table[i] || !evdev_table[i]->exist)
 128                 return -ENODEV;
 129
 130         if ((accept_err = input_accept_process(&(evdev_table[i]->handle), file)))
 131                 return accept_err;
 132
 133         if (!(list = kmalloc(sizeof(struct evdev_list), GFP_KERNEL)))
 134                 return -ENOMEM;
 135         memset(list, 0, sizeof(struct evdev_list));
 136
 137         list->evdev = evdev_table[i];
 138         list_add_tail(&list->node, &evdev_table[i]->list);
 139         file->private_data = list;
 140
 141         if (!list->evdev->open++)
 142                 if (list->evdev->exist)
 143                         input_open_device(&list->evdev->handle);
 144
 145         return 0;
 146 }
 147
 148 static ssize_t evdev_write(struct file * file, const char __user * buffer, size_t count, loff_t *ppos)
 149 {
 150         struct evdev_list *list = file->private_data;
 151         struct input_event event;
 152         int retval = 0;
 153
 154         if (!list->evdev->exist) return -ENODEV;
 155
 156         while (retval < count) {
 157
 158                 if (copy_from_user(&event, buffer + retval, sizeof(struct input_event)))
 159                         return -EFAULT;
 160                 input_event(list->evdev->handle.dev, event.type, event.code, event.value);
 161                 retval += sizeof(struct input_event);
 162         }
 163
 164         return retval;
 165 }
 166
 167 static ssize_t evdev_read(struct file * file, char __user * buffer, size_t count, loff_t *ppos)
 168 {
 169         struct evdev_list *list = file->private_data;
 170         int retval;
 171
 172         if (count < sizeof(struct input_event))
 173                 return -EINVAL;
 174
 175         if (list->head == list->tail && list->evdev->exist && (file->f_flags & O_NONBLOCK))
 176                 return -EAGAIN;
 177
 178         retval = wait_event_interruptible(list->evdev->wait,
 179                 list->head != list->tail || (!list->evdev->exist));
 180
 181         if (retval)
 182                 return retval;
 183
 184         if (!list->evdev->exist)
 185                 return -ENODEV;
 186
 187         while (list->head != list->tail && retval + sizeof(struct input_event) <= count) {
 188                 if (copy_to_user(buffer + retval, list->buffer + list->tail,
 189                          sizeof(struct input_event))) return -EFAULT;
 190                 list->tail = (list->tail + 1) & (EVDEV_BUFFER_SIZE - 1);
 191                 retval += sizeof(struct input_event);
 192         }
 193
 194         return retval;
 195 }
 196
 197 /* No kernel lock - fine */
 198 static unsigned int evdev_poll(struct file *file, poll_table *wait)
 199 {
 200         struct evdev_list *list = file->private_data;
 201         poll_wait(file, &list->evdev->wait, wait);
 202         return ((list->head == list->tail) ? 0 : (POLLIN | POLLRDNORM)) |
 203                 (list->evdev->exist ? 0 : (POLLHUP | POLLERR));
 204 }
 205
 206 static int evdev_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
 207 {
 208         struct evdev_list *list = file->private_data;
 209         struct evdev *evdev = list->evdev;
 210         struct input_dev *dev = evdev->handle.dev;
 211         struct input_absinfo abs;
 212         void __user *p = (void __user *)arg;
 213         int __user *ip = (int __user *)arg;
 214         int i, t, u, v;
 215
 216         if (!evdev->exist) return -ENODEV;
 217
 218         switch (cmd) {
 219
 220                 case EVIOCGVERSION:
 221                         return put_user(EV_VERSION, ip);
 222
 223                 case EVIOCGID:
 224                         return copy_to_user(p, &dev->id, sizeof(struct input_id)) ? -EFAULT : 0;
 225
 226                 case EVIOCGKEYCODE:
 227                         if (get_user(t, ip)) return -EFAULT;
 228                         if (t < 0 || t >= dev->keycodemax || !dev->keycodesize) return -EINVAL;
 229                         if (put_user(INPUT_KEYCODE(dev, t), ip + 1)) return -EFAULT;
 230                         return 0;
 231
 232                 case EVIOCSKEYCODE:
 233                         if (get_user(t, ip)) return -EFAULT;
 234                         if (t < 0 || t >= dev->keycodemax || !dev->keycodesize) return -EINVAL;
 235                         if (get_user(v, ip + 1)) return -EFAULT;
 236                         if (v < 0 || v > KEY_MAX) return -EINVAL;
 237                         u = SET_INPUT_KEYCODE(dev, t, v);
 238                         clear_bit(u, dev->keybit);
 239                         set_bit(v, dev->keybit);
 240                         for (i = 0; i < dev->keycodemax; i++)
 241                                 if (INPUT_KEYCODE(dev,i) == u)
 242                                         set_bit(u, dev->keybit);
 243                         return 0;
 244
 245                 case EVIOCSFF:
 246                         if (dev->upload_effect) {
 247                                 struct ff_effect effect;
 248                                 int err;
 249
 250                                 if (copy_from_user(&effect, p, sizeof(effect)))
 251                                         return -EFAULT;
 252                                 err = dev->upload_effect(dev, &effect);
 253                                 if (put_user(effect.id, &(((struct ff_effect __user *)arg)->id)))
 254                                         return -EFAULT;
 255                                 return err;
 256                         }
 257                         else return -ENOSYS;
 258
 259                 case EVIOCRMFF:
 260                         if (dev->erase_effect) {
 261                                 return dev->erase_effect(dev, (int)arg);
 262                         }
 263                         else return -ENOSYS;
 264
 265                 case EVIOCGEFFECTS:
 266                         if (put_user(dev->ff_effects_max, ip))
 267                                 return -EFAULT;
 268                         return 0;
 269
 270                 case EVIOCGRAB:
 271                         if (arg) {
 272                                 if (evdev->grab)
 273                                         return -EBUSY;
 274                                 if (input_grab_device(&evdev->handle))
 275                                         return -EBUSY;
 276                                 evdev->grab = list;
 277                                 return 0;
 278                         } else {
 279                                 if (evdev->grab != list)
 280                                         return -EINVAL;
 281                                 input_release_device(&evdev->handle);
 282                                 evdev->grab = NULL;
 283                                 return 0;
 284                         }
 285
 286                 default:
 287
 288                         if (_IOC_TYPE(cmd) != 'E' || _IOC_DIR(cmd) != _IOC_READ)
 289                                 return -EINVAL;
 290
 291                         if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0,0))) {
 292
 293                                 long *bits;
 294                                 int len;
 295
 296                                 switch (_IOC_NR(cmd) & EV_MAX) {
 297                                         case      0: bits = dev->evbit;  len = EV_MAX;  break;
 298                                         case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
 299                                         case EV_REL: bits = dev->relbit; len = REL_MAX; break;
 300                                         case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
 301                                         case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break;
 302                                         case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
 303                                         case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
 304                                         case EV_FF:  bits = dev->ffbit;  len = FF_MAX;  break;
 305                                         default: return -EINVAL;
 306                                 }
 307                                 len = NBITS(len) * sizeof(long);
 308                                 if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
 309                                 return copy_to_user(p, bits, len) ? -EFAULT : len;
 310                         }
 311
 312                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGKEY(0))) {
 313                                 int len;
 314                                 len = NBITS(KEY_MAX) * sizeof(long);
 315                                 if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
 316                                 return copy_to_user(p, dev->key, len) ? -EFAULT : len;
 317                         }
 318
 319                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGLED(0))) {
 320                                 int len;
 321                                 len = NBITS(LED_MAX) * sizeof(long);
 322                                 if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
 323                                 return copy_to_user(p, dev->led, len) ? -EFAULT : len;
 324                         }
 325
 326                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSND(0))) {
 327                                 int len;
 328                                 len = NBITS(SND_MAX) * sizeof(long);
 329                                 if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
 330                                 return copy_to_user(p, dev->snd, len) ? -EFAULT : len;
 331                         }
 332
 333                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGNAME(0))) {
 334                                 int len;
 335                                 if (!dev->name) return -ENOENT;
 336                                 len = strlen(dev->name) + 1;
 337                                 if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
 338                                 return copy_to_user(p, dev->name, len) ? -EFAULT : len;
 339                         }
 340
 341                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGPHYS(0))) {
 342                                 int len;
 343                                 if (!dev->phys) return -ENOENT;
 344                                 len = strlen(dev->phys) + 1;
 345                                 if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
 346                                 return copy_to_user(p, dev->phys, len) ? -EFAULT : len;
 347                         }
 348
 349                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGUNIQ(0))) {
 350                                 int len;
 351                                 if (!dev->uniq) return -ENOENT;
 352                                 len = strlen(dev->uniq) + 1;
 353                                 if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
 354                                 return copy_to_user(p, dev->uniq, len) ? -EFAULT : len;
 355                         }
 356
 357                         if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {
 358
 359                                 int t = _IOC_NR(cmd) & ABS_MAX;
 360
 361                                 abs.value = dev->abs[t];
 362                                 abs.minimum = dev->absmin[t];
 363                                 abs.maximum = dev->absmax[t];
 364                                 abs.fuzz = dev->absfuzz[t];
 365                                 abs.flat = dev->absflat[t];
 366
 367                                 if (copy_to_user(p, &abs, sizeof(struct input_absinfo)))
 368                                         return -EFAULT;
 369
 370                                 return 0;
 371                         }
 372
 373                         if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) {
 374
 375                                 int t = _IOC_NR(cmd) & ABS_MAX;
 376
 377                                 if (copy_from_user(&abs, p, sizeof(struct input_absinfo)))
 378                                         return -EFAULT;
 379
 380                                 dev->abs[t] = abs.value;
 381                                 dev->absmin[t] = abs.minimum;
 382                                 dev->absmax[t] = abs.maximum;
 383                                 dev->absfuzz[t] = abs.fuzz;
 384                                 dev->absflat[t] = abs.flat;
 385
 386                                 return 0;
 387                         }
 388         }
 389         return -EINVAL;
 390 }
 391
 392 static struct file_operations evdev_fops = {
 393         .owner =        THIS_MODULE,
 394         .read =         evdev_read,
 395         .write =        evdev_write,
 396         .poll =         evdev_poll,
 397         .open =         evdev_open,
 398         .release =      evdev_release,
 399         .ioctl =        evdev_ioctl,
 400         .fasync =       evdev_fasync,
 401         .flush =        evdev_flush
 402 };
 403
 404 static struct input_handle *evdev_connect(struct input_handler *handler, struct input_dev *dev, struct input_device_id *id)
 405 {
 406         struct evdev *evdev;
 407         int minor;
 408
 409         for (minor = 0; minor < EVDEV_MINORS && evdev_table[minor]; minor++);
 410         if (minor == EVDEV_MINORS) {
 411                 printk(KERN_ERR "evdev: no more free evdev devices\n");
 412                 return NULL;
 413         }
 414
 415         if (!(evdev = kmalloc(sizeof(struct evdev), GFP_KERNEL)))
 416                 return NULL;
 417         memset(evdev, 0, sizeof(struct evdev));
 418
 419         INIT_LIST_HEAD(&evdev->list);
 420         init_waitqueue_head(&evdev->wait);
 421
 422         evdev->exist = 1;
 423         evdev->minor = minor;
 424         evdev->handle.dev = dev;
 425         evdev->handle.name = evdev->name;
 426         evdev->handle.handler = handler;
 427         evdev->handle.private = evdev;
 428         sprintf(evdev->name, "event%d", minor);
 429
 430         evdev_table[minor] = evdev;
 431
 432         devfs_mk_cdev(MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + minor),
 433                         S_IFCHR|S_IRUGO|S_IWUSR, "input/event%d", minor);
 434         class_simple_device_add(input_class,
 435                                 MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + minor),
 436                                 dev->dev, "event%d", minor);
 437
 438         return &evdev->handle;
 439 }
 440
 441 static void evdev_disconnect(struct input_handle *handle)
 442 {
 443         struct evdev *evdev = handle->private;
 444         struct evdev_list *list;
 445
 446         class_simple_device_remove(MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + evdev->minor));
 447         devfs_remove("input/event%d", evdev->minor);
 448         evdev->exist = 0;
 449
 450         if (evdev->open) {
 451                 input_close_device(handle);
 452                 wake_up_interruptible(&evdev->wait);
 453                 list_for_each_entry(list, &evdev->list, node)
 454                         kill_fasync(&list->fasync, SIGIO, POLL_HUP);
 455         } else
 456                 evdev_free(evdev);
 457 }
 458
 459 static struct input_device_id evdev_ids[] = {
 460         { .driver_info = 1 },   /* Matches all devices */
 461         { },                    /* Terminating zero entry */
 462 };
 463
 464 MODULE_DEVICE_TABLE(input, evdev_ids);
 465
 466 static struct input_handler evdev_handler = {
 467         .event =        evdev_event,
 468         .connect =      evdev_connect,
 469         .disconnect =   evdev_disconnect,
 470         .fops =         &evdev_fops,
 471         .minor =        EVDEV_MINOR_BASE,
 472         .name =         "evdev",
 473         .id_table =     evdev_ids,
 474 };
 475
 476 static int __init evdev_init(void)
 477 {
 478         input_register_handler(&evdev_handler);
 479         return 0;
 480 }
 481
 482 static void __exit evdev_exit(void)
 483 {
 484         input_unregister_handler(&evdev_handler);
 485 }
 486
 487 module_init(evdev_init);
 488 module_exit(evdev_exit);
 489
 490 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
 491 MODULE_DESCRIPTION("Input driver event char devices");
 492 MODULE_LICENSE("GPL");