drivers/input/misc/uinput.c

   1 /*
   2  *  User level driver support for input subsystem
   3  *
   4  * Heavily based on evdev.c by Vojtech Pavlik
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  19  *
  20  * Author: Aristeu Sergio Rozanski Filho <aris@cathedrallabs.org>
  21  *
  22  * Changes/Revisions:
  23  *      0.1     20/06/2002
  24  *              - first public version
  25  */
  26 #include <linux/poll.h>
  27 #include <linux/slab.h>
  28 #include <linux/module.h>
  29 #include <linux/init.h>
  30 #include <linux/input.h>
  31 #include <linux/smp_lock.h>
  32 #include <linux/fs.h>
  33 #include <linux/miscdevice.h>
  34 #include <linux/uinput.h>
  35
  36 static int uinput_dev_open(struct input_dev *dev)
  37 {
  38         return 0;
  39 }
  40
  41 static void uinput_dev_close(struct input_dev *dev)
  42 {
  43
  44 }
  45
  46 static int uinput_dev_event(struct input_dev *dev, unsigned int type, unsigned int code, int value)
  47 {
  48         struct uinput_device    *udev;
  49
  50         udev = (struct uinput_device *)dev->private;
  51
  52         udev->buff[udev->head].type = type;
  53         udev->buff[udev->head].code = code;
  54         udev->buff[udev->head].value = value;
  55         do_gettimeofday(&udev->buff[udev->head].time);
  56         udev->head = (udev->head + 1) % UINPUT_BUFFER_SIZE;
  57
  58         wake_up_interruptible(&udev->waitq);
  59
  60         return 0;
  61 }
  62
  63 static int uinput_dev_upload_effect(struct input_dev *dev, struct ff_effect *effect)
  64 {
  65         return 0;
  66 }
  67
  68 static int uinput_dev_erase_effect(struct input_dev *dev, int effect_id)
  69 {
  70         return 0;
  71 }
  72
  73 static int uinput_create_device(struct uinput_device *udev)
  74 {
  75         if (!udev->dev->name) {
  76                 printk(KERN_DEBUG "%s: write device info first\n", UINPUT_NAME);
  77                 return -EINVAL;
  78         }
  79
  80         udev->dev->open = uinput_dev_open;
  81         udev->dev->close = uinput_dev_close;
  82         udev->dev->event = uinput_dev_event;
  83         udev->dev->upload_effect = uinput_dev_upload_effect;
  84         udev->dev->erase_effect = uinput_dev_erase_effect;
  85         udev->dev->private = udev;
  86
  87         init_waitqueue_head(&(udev->waitq));
  88
  89         input_register_device(udev->dev);
  90
  91         set_bit(UIST_CREATED, &(udev->state));
  92
  93         return 0;
  94 }
  95
  96 static int uinput_destroy_device(struct uinput_device *udev)
  97 {
  98         if (!test_bit(UIST_CREATED, &(udev->state))) {
  99                 printk(KERN_WARNING "%s: create the device first\n", UINPUT_NAME);
 100                 return -EINVAL;
 101         }
 102
 103         input_unregister_device(udev->dev);
 104
 105         clear_bit(UIST_CREATED, &(udev->state));
 106
 107         return 0;
 108 }
 109
 110 static int uinput_open(struct inode *inode, struct file *file)
 111 {
 112         struct uinput_device    *newdev;
 113         struct input_dev        *newinput;
 114
 115         newdev = kmalloc(sizeof(struct uinput_device), GFP_KERNEL);
 116         if (!newdev)
 117                 goto error;
 118         memset(newdev, 0, sizeof(struct uinput_device));
 119
 120         newinput = kmalloc(sizeof(struct input_dev), GFP_KERNEL);
 121         if (!newinput)
 122                 goto cleanup;
 123         memset(newinput, 0, sizeof(struct input_dev));
 124
 125         newdev->dev = newinput;
 126
 127         file->private_data = newdev;
 128
 129         return 0;
 130 cleanup:
 131         kfree(newdev);
 132 error:
 133         return -ENOMEM;
 134 }
 135
 136 static int uinput_validate_absbits(struct input_dev *dev)
 137 {
 138         unsigned int cnt;
 139         int retval = 0;
 140
 141         for (cnt = 0; cnt < ABS_MAX; cnt++) {
 142                 if (!test_bit(cnt, dev->absbit))
 143                         continue;
 144
 145                 if (/*!dev->absmin[cnt] || !dev->absmax[cnt] || */
 146                     (dev->absmax[cnt] <= dev->absmin[cnt])) {
 147                         printk(KERN_DEBUG
 148                                 "%s: invalid abs[%02x] min:%d max:%d\n",
 149                                 UINPUT_NAME, cnt,
 150                                 dev->absmin[cnt], dev->absmax[cnt]);
 151                         retval = -EINVAL;
 152                         break;
 153                 }
 154
 155                 if ((dev->absflat[cnt] < dev->absmin[cnt]) ||
 156                     (dev->absflat[cnt] > dev->absmax[cnt])) {
 157                         printk(KERN_DEBUG
 158                                 "%s: absflat[%02x] out of range: %d "
 159                                 "(min:%d/max:%d)\n",
 160                                 UINPUT_NAME, cnt, dev->absflat[cnt],
 161                                 dev->absmin[cnt], dev->absmax[cnt]);
 162                         retval = -EINVAL;
 163                         break;
 164                 }
 165         }
 166         return retval;
 167 }
 168
 169 static int uinput_alloc_device(struct file *file, const char *buffer, size_t count)
 170 {
 171         struct uinput_user_dev  *user_dev;
 172         struct input_dev        *dev;
 173         struct uinput_device    *udev;
 174         int                     size,
 175                                 retval;
 176
 177         retval = count;
 178
 179         udev = (struct uinput_device *)file->private_data;
 180         dev = udev->dev;
 181
 182         user_dev = kmalloc(sizeof(*user_dev), GFP_KERNEL);
 183         if (!user_dev) {
 184                 retval = -ENOMEM;
 185                 goto exit;
 186         }
 187
 188         if (copy_from_user(user_dev, buffer, sizeof(struct uinput_user_dev))) {
 189                 retval = -EFAULT;
 190                 goto exit;
 191         }
 192
 193         if (NULL != dev->name)
 194                 kfree(dev->name);
 195
 196         size = strnlen(user_dev->name, UINPUT_MAX_NAME_SIZE) + 1;
 197         dev->name = kmalloc(size, GFP_KERNEL);
 198         if (!dev->name) {
 199                 retval = -ENOMEM;
 200                 goto exit;
 201         }
 202
 203         strlcpy(dev->name, user_dev->name, size);
 204         dev->id.bustype = user_dev->id.bustype;
 205         dev->id.vendor  = user_dev->id.vendor;
 206         dev->id.product = user_dev->id.product;
 207         dev->id.version = user_dev->id.version;
 208         dev->ff_effects_max = user_dev->ff_effects_max;
 209
 210         size = sizeof(int) * (ABS_MAX + 1);
 211         memcpy(dev->absmax, user_dev->absmax, size);
 212         memcpy(dev->absmin, user_dev->absmin, size);
 213         memcpy(dev->absfuzz, user_dev->absfuzz, size);
 214         memcpy(dev->absflat, user_dev->absflat, size);
 215
 216         /* check if absmin/absmax/absfuzz/absflat are filled as
 217          * told in Documentation/input/input-programming.txt */
 218         if (test_bit(EV_ABS, dev->evbit)) {
 219                 retval = uinput_validate_absbits(dev);
 220                 if (retval < 0)
 221                         kfree(dev->name);
 222         }
 223
 224 exit:
 225         kfree(user_dev);
 226         return retval;
 227 }
 228
 229 static ssize_t uinput_write(struct file *file, const char *buffer, size_t count, loff_t *ppos)
 230 {
 231         struct uinput_device    *udev = file->private_data;
 232
 233         if (test_bit(UIST_CREATED, &(udev->state))) {
 234                 struct input_event      ev;
 235
 236                 if (copy_from_user(&ev, buffer, sizeof(struct input_event)))
 237                         return -EFAULT;
 238                 input_event(udev->dev, ev.type, ev.code, ev.value);
 239         }
 240         else
 241                 count = uinput_alloc_device(file, buffer, count);
 242
 243         return count;
 244 }
 245
 246 static ssize_t uinput_read(struct file *file, char *buffer, size_t count, loff_t *ppos)
 247 {
 248         struct uinput_device *udev = file->private_data;
 249         int retval = 0;
 250
 251         if (!test_bit(UIST_CREATED, &(udev->state)))
 252                 return -ENODEV;
 253
 254         if ((udev->head == udev->tail) && (file->f_flags & O_NONBLOCK))
 255                 return -EAGAIN;
 256
 257         retval = wait_event_interruptible(udev->waitq,
 258                         (udev->head != udev->tail) ||
 259                         !test_bit(UIST_CREATED, &(udev->state)));
 260
 261         if (retval)
 262                 return retval;
 263
 264         if (!test_bit(UIST_CREATED, &(udev->state)))
 265                 return -ENODEV;
 266
 267         while ((udev->head != udev->tail) &&
 268             (retval + sizeof(struct input_event) <= count)) {
 269                 if (copy_to_user(buffer + retval, &(udev->buff[udev->tail]),
 270                     sizeof(struct input_event))) return -EFAULT;
 271                 udev->tail = (udev->tail + 1) % UINPUT_BUFFER_SIZE;
 272                 retval += sizeof(struct input_event);
 273         }
 274
 275         return retval;
 276 }
 277
 278 static unsigned int uinput_poll(struct file *file, poll_table *wait)
 279 {
 280         struct uinput_device *udev = file->private_data;
 281
 282         poll_wait(file, &udev->waitq, wait);
 283
 284         if (udev->head != udev->tail)
 285                 return POLLIN | POLLRDNORM;
 286
 287         return 0;
 288 }
 289
 290 static int uinput_burn_device(struct uinput_device *udev)
 291 {
 292         if (test_bit(UIST_CREATED, &(udev->state)))
 293                 uinput_destroy_device(udev);
 294
 295         kfree(udev->dev);
 296         kfree(udev);
 297
 298         return 0;
 299 }
 300
 301 static int uinput_close(struct inode *inode, struct file *file)
 302 {
 303         return uinput_burn_device((struct uinput_device *)file->private_data);
 304 }
 305
 306 static int uinput_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
 307 {
 308         int                     retval = 0;
 309         struct uinput_device    *udev;
 310
 311         udev = (struct uinput_device *)file->private_data;
 312
 313         /* device attributes can not be changed after the device is created */
 314         if (cmd >= UI_SET_EVBIT && test_bit(UIST_CREATED, &(udev->state)))
 315                 return -EINVAL;
 316
 317         switch (cmd) {
 318                 case UI_DEV_CREATE:
 319                         retval = uinput_create_device(udev);
 320                         break;
 321
 322                 case UI_DEV_DESTROY:
 323                         retval = uinput_destroy_device(udev);
 324                         break;
 325
 326                 case UI_SET_EVBIT:
 327                         if (arg > EV_MAX) {
 328                                 retval = -EINVAL;
 329                                 break;
 330                         }
 331                         set_bit(arg, udev->dev->evbit);
 332                         break;
 333
 334                 case UI_SET_KEYBIT:
 335                         if (arg > KEY_MAX) {
 336                                 retval = -EINVAL;
 337                                 break;
 338                         }
 339                         set_bit(arg, udev->dev->keybit);
 340                         break;
 341
 342                 case UI_SET_RELBIT:
 343                         if (arg > REL_MAX) {
 344                                 retval = -EINVAL;
 345                                 break;
 346                         }
 347                         set_bit(arg, udev->dev->relbit);
 348                         break;
 349
 350                 case UI_SET_ABSBIT:
 351                         if (arg > ABS_MAX) {
 352                                 retval = -EINVAL;
 353                                 break;
 354                         }
 355                         set_bit(arg, udev->dev->absbit);
 356                         break;
 357
 358                 case UI_SET_MSCBIT:
 359                         if (arg > MSC_MAX) {
 360                                 retval = -EINVAL;
 361                                 break;
 362                         }
 363                         set_bit(arg, udev->dev->mscbit);
 364                         break;
 365
 366                 case UI_SET_LEDBIT:
 367                         if (arg > LED_MAX) {
 368                                 retval = -EINVAL;
 369                                 break;
 370                         }
 371                         set_bit(arg, udev->dev->ledbit);
 372                         break;
 373
 374                 case UI_SET_SNDBIT:
 375                         if (arg > SND_MAX) {
 376                                 retval = -EINVAL;
 377                                 break;
 378                         }
 379                         set_bit(arg, udev->dev->sndbit);
 380                         break;
 381
 382                 case UI_SET_FFBIT:
 383                         if (arg > FF_MAX) {
 384                                 retval = -EINVAL;
 385                                 break;
 386                         }
 387                         set_bit(arg, udev->dev->ffbit);
 388                         break;
 389
 390                 default:
 391                         retval = -EFAULT;
 392         }
 393         return retval;
 394 }
 395
 396 struct file_operations uinput_fops = {
 397         .owner =        THIS_MODULE,
 398         .open =         uinput_open,
 399         .release =      uinput_close,
 400         .read =         uinput_read,
 401         .write =        uinput_write,
 402         .poll =         uinput_poll,
 403         .ioctl =        uinput_ioctl,
 404 };
 405
 406 static struct miscdevice uinput_misc = {
 407         .fops =         &uinput_fops,
 408         .minor =        UINPUT_MINOR,
 409         .name =         UINPUT_NAME,
 410 };
 411
 412 static int __init uinput_init(void)
 413 {
 414         return misc_register(&uinput_misc);
 415 }
 416
 417 static void __exit uinput_exit(void)
 418 {
 419         misc_deregister(&uinput_misc);
 420 }
 421
 422 MODULE_AUTHOR("Aristeu Sergio Rozanski Filho");
 423 MODULE_DESCRIPTION("User level driver support for input subsystem");
 424 MODULE_LICENSE("GPL");
 425
 426 module_init(uinput_init);
 427 module_exit(uinput_exit);
 428