drivers/i2c/i2c-dev.c

   1 /*
   2     i2c-dev.c - i2c-bus driver, char device interface
   3
   4     Copyright (C) 1995-97 Simon G. Vogl
   5     Copyright (C) 1998-99 Frodo Looijaard <frodol@dds.nl>
   6     Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com>
   7
   8     This program is free software; you can redistribute it and/or modify
   9     it under the terms of the GNU General Public License as published by
  10     the Free Software Foundation; either version 2 of the License, or
  11     (at your option) any later version.
  12
  13     This program is distributed in the hope that it will be useful,
  14     but WITHOUT ANY WARRANTY; without even the implied warranty of
  15     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16     GNU General Public License for more details.
  17
  18     You should have received a copy of the GNU General Public License
  19     along with this program; if not, write to the Free Software
  20     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21 */
  22
  23 /* Note that this is a complete rewrite of Simon Vogl's i2c-dev module.
  24    But I have used so much of his original code and ideas that it seems
  25    only fair to recognize him as co-author -- Frodo */
  26
  27 /* The I2C_RDWR ioctl code is written by Kolja Waschk <waschk@telos.de> */
  28
  29 #include <linux/kernel.h>
  30 #include <linux/module.h>
  31 #include <linux/fs.h>
  32 #include <linux/slab.h>
  33 #include <linux/init.h>
  34 #include <linux/list.h>
  35 #include <linux/i2c.h>
  36 #include <linux/i2c-dev.h>
  37 #include <asm/uaccess.h>
  38
  39 static struct i2c_driver i2cdev_driver;
  40
  41 /*
  42  * An i2c_dev represents an i2c_adapter ... an I2C or SMBus master, not a
  43  * slave (i2c_client) with which messages will be exchanged.  It's coupled
  44  * with a character special file which is accessed by user mode drivers.
  45  *
  46  * The list of i2c_dev structures is parallel to the i2c_adapter lists
  47  * maintained by the driver model, and is updated using notifications
  48  * delivered to the i2cdev_driver.
  49  */
  50 struct i2c_dev {
  51         struct list_head list;
  52         struct i2c_adapter *adap;
  53         struct device *dev;
  54 };
  55
  56 #define I2C_MINORS      256
  57 static LIST_HEAD(i2c_dev_list);
  58 static DEFINE_SPINLOCK(i2c_dev_list_lock);
  59
  60 static struct i2c_dev *i2c_dev_get_by_minor(unsigned index)
  61 {
  62         struct i2c_dev *i2c_dev;
  63
  64         spin_lock(&i2c_dev_list_lock);
  65         list_for_each_entry(i2c_dev, &i2c_dev_list, list) {
  66                 if (i2c_dev->adap->nr == index)
  67                         goto found;
  68         }
  69         i2c_dev = NULL;
  70 found:
  71         spin_unlock(&i2c_dev_list_lock);
  72         return i2c_dev;
  73 }
  74
  75 static struct i2c_dev *get_free_i2c_dev(struct i2c_adapter *adap)
  76 {
  77         struct i2c_dev *i2c_dev;
  78
  79         if (adap->nr >= I2C_MINORS) {
  80                 printk(KERN_ERR "i2c-dev: Out of device minors (%d)\n",
  81                        adap->nr);
  82                 return ERR_PTR(-ENODEV);
  83         }
  84
  85         i2c_dev = kzalloc(sizeof(*i2c_dev), GFP_KERNEL);
  86         if (!i2c_dev)
  87                 return ERR_PTR(-ENOMEM);
  88         i2c_dev->adap = adap;
  89
  90         spin_lock(&i2c_dev_list_lock);
  91         list_add_tail(&i2c_dev->list, &i2c_dev_list);
  92         spin_unlock(&i2c_dev_list_lock);
  93         return i2c_dev;
  94 }
  95
  96 static void return_i2c_dev(struct i2c_dev *i2c_dev)
  97 {
  98         spin_lock(&i2c_dev_list_lock);
  99         list_del(&i2c_dev->list);
 100         spin_unlock(&i2c_dev_list_lock);
 101         kfree(i2c_dev);
 102 }
 103
 104 static ssize_t show_adapter_name(struct device *dev,
 105                                  struct device_attribute *attr, char *buf)
 106 {
 107         struct i2c_dev *i2c_dev = i2c_dev_get_by_minor(MINOR(dev->devt));
 108
 109         if (!i2c_dev)
 110                 return -ENODEV;
 111         return sprintf(buf, "%s\n", i2c_dev->adap->name);
 112 }
 113 static DEVICE_ATTR(name, S_IRUGO, show_adapter_name, NULL);
 114
 115 /* ------------------------------------------------------------------------- */
 116
 117 /*
 118  * After opening an instance of this character special file, a file
 119  * descriptor starts out associated only with an i2c_adapter (and bus).
 120  *
 121  * Using the I2C_RDWR ioctl(), you can then *immediately* issue i2c_msg
 122  * traffic to any devices on the bus used by that adapter.  That's because
 123  * the i2c_msg vectors embed all the addressing information they need, and
 124  * are submitted directly to an i2c_adapter.  However, SMBus-only adapters
 125  * don't support that interface.
 126  *
 127  * To use read()/write() system calls on that file descriptor, or to use
 128  * SMBus interfaces (and work with SMBus-only hosts!), you must first issue
 129  * an I2C_SLAVE (or I2C_SLAVE_FORCE) ioctl.  That configures an anonymous
 130  * (never registered) i2c_client so it holds the addressing information
 131  * needed by those system calls and by this SMBus interface.
 132  */
 133
 134 static ssize_t i2cdev_read (struct file *file, char __user *buf, size_t count,
 135                             loff_t *offset)
 136 {
 137         char *tmp;
 138         int ret;
 139
 140         struct i2c_client *client = (struct i2c_client *)file->private_data;
 141
 142         if (count > 8192)
 143                 count = 8192;
 144
 145         tmp = kmalloc(count,GFP_KERNEL);
 146         if (tmp==NULL)
 147                 return -ENOMEM;
 148
 149         pr_debug("i2c-dev: i2c-%d reading %zd bytes.\n",
 150                 iminor(file->f_path.dentry->d_inode), count);
 151
 152         ret = i2c_master_recv(client,tmp,count);
 153         if (ret >= 0)
 154                 ret = copy_to_user(buf,tmp,count)?-EFAULT:ret;
 155         kfree(tmp);
 156         return ret;
 157 }
 158
 159 static ssize_t i2cdev_write (struct file *file, const char __user *buf, size_t count,
 160                              loff_t *offset)
 161 {
 162         int ret;
 163         char *tmp;
 164         struct i2c_client *client = (struct i2c_client *)file->private_data;
 165
 166         if (count > 8192)
 167                 count = 8192;
 168
 169         tmp = kmalloc(count,GFP_KERNEL);
 170         if (tmp==NULL)
 171                 return -ENOMEM;
 172         if (copy_from_user(tmp,buf,count)) {
 173                 kfree(tmp);
 174                 return -EFAULT;
 175         }
 176
 177         pr_debug("i2c-dev: i2c-%d writing %zd bytes.\n",
 178                 iminor(file->f_path.dentry->d_inode), count);
 179
 180         ret = i2c_master_send(client,tmp,count);
 181         kfree(tmp);
 182         return ret;
 183 }
 184
 185 static int i2cdev_check(struct device *dev, void *addrp)
 186 {
 187         struct i2c_client *client = i2c_verify_client(dev);
 188
 189         if (!client || client->addr != *(unsigned int *)addrp)
 190                 return 0;
 191
 192         return dev->driver ? -EBUSY : 0;
 193 }
 194
 195 /* This address checking function differs from the one in i2c-core
 196    in that it considers an address with a registered device, but no
 197    driver bound to it, as NOT busy. */
 198 static int i2cdev_check_addr(struct i2c_adapter *adapter, unsigned int addr)
 199 {
 200         return device_for_each_child(&adapter->dev, &addr, i2cdev_check);
 201 }
 202
 203 static noinline int i2cdev_ioctl_rdrw(struct i2c_client *client,
 204                 unsigned long arg)
 205 {
 206         struct i2c_rdwr_ioctl_data rdwr_arg;
 207         struct i2c_msg *rdwr_pa;
 208         u8 __user **data_ptrs;
 209         int i, res;
 210
 211         if (copy_from_user(&rdwr_arg,
 212                            (struct i2c_rdwr_ioctl_data __user *)arg,
 213                            sizeof(rdwr_arg)))
 214                 return -EFAULT;
 215
 216         /* Put an arbitrary limit on the number of messages that can
 217          * be sent at once */
 218         if (rdwr_arg.nmsgs > I2C_RDRW_IOCTL_MAX_MSGS)
 219                 return -EINVAL;
 220
 221         rdwr_pa = (struct i2c_msg *)
 222                 kmalloc(rdwr_arg.nmsgs * sizeof(struct i2c_msg),
 223                 GFP_KERNEL);
 224         if (!rdwr_pa)
 225                 return -ENOMEM;
 226
 227         if (copy_from_user(rdwr_pa, rdwr_arg.msgs,
 228                            rdwr_arg.nmsgs * sizeof(struct i2c_msg))) {
 229                 kfree(rdwr_pa);
 230                 return -EFAULT;
 231         }
 232
 233         data_ptrs = kmalloc(rdwr_arg.nmsgs * sizeof(u8 __user *), GFP_KERNEL);
 234         if (data_ptrs == NULL) {
 235                 kfree(rdwr_pa);
 236                 return -ENOMEM;
 237         }
 238
 239         res = 0;
 240         for (i = 0; i < rdwr_arg.nmsgs; i++) {
 241                 /* Limit the size of the message to a sane amount;
 242                  * and don't let length change either. */
 243                 if ((rdwr_pa[i].len > 8192) ||
 244                     (rdwr_pa[i].flags & I2C_M_RECV_LEN)) {
 245                         res = -EINVAL;
 246                         break;
 247                 }
 248                 data_ptrs[i] = (u8 __user *)rdwr_pa[i].buf;
 249                 rdwr_pa[i].buf = kmalloc(rdwr_pa[i].len, GFP_KERNEL);
 250                 if (rdwr_pa[i].buf == NULL) {
 251                         res = -ENOMEM;
 252                         break;
 253                 }
 254                 if (copy_from_user(rdwr_pa[i].buf, data_ptrs[i],
 255                                    rdwr_pa[i].len)) {
 256                                 ++i; /* Needs to be kfreed too */
 257                                 res = -EFAULT;
 258                         break;
 259                 }
 260         }
 261         if (res < 0) {
 262                 int j;
 263                 for (j = 0; j < i; ++j)
 264                         kfree(rdwr_pa[j].buf);
 265                 kfree(data_ptrs);
 266                 kfree(rdwr_pa);
 267                 return res;
 268         }
 269
 270         res = i2c_transfer(client->adapter, rdwr_pa, rdwr_arg.nmsgs);
 271         while (i-- > 0) {
 272                 if (res >= 0 && (rdwr_pa[i].flags & I2C_M_RD)) {
 273                         if (copy_to_user(data_ptrs[i], rdwr_pa[i].buf,
 274                                          rdwr_pa[i].len))
 275                                 res = -EFAULT;
 276                 }
 277                 kfree(rdwr_pa[i].buf);
 278         }
 279         kfree(data_ptrs);
 280         kfree(rdwr_pa);
 281         return res;
 282 }
 283
 284 static noinline int i2cdev_ioctl_smbus(struct i2c_client *client,
 285                 unsigned long arg)
 286 {
 287         struct i2c_smbus_ioctl_data data_arg;
 288         union i2c_smbus_data temp;
 289         int datasize, res;
 290
 291         if (copy_from_user(&data_arg,
 292                            (struct i2c_smbus_ioctl_data __user *) arg,
 293                            sizeof(struct i2c_smbus_ioctl_data)))
 294                 return -EFAULT;
 295         if ((data_arg.size != I2C_SMBUS_BYTE) &&
 296             (data_arg.size != I2C_SMBUS_QUICK) &&
 297             (data_arg.size != I2C_SMBUS_BYTE_DATA) &&
 298             (data_arg.size != I2C_SMBUS_WORD_DATA) &&
 299             (data_arg.size != I2C_SMBUS_PROC_CALL) &&
 300             (data_arg.size != I2C_SMBUS_BLOCK_DATA) &&
 301             (data_arg.size != I2C_SMBUS_I2C_BLOCK_BROKEN) &&
 302             (data_arg.size != I2C_SMBUS_I2C_BLOCK_DATA) &&
 303             (data_arg.size != I2C_SMBUS_BLOCK_PROC_CALL)) {
 304                 dev_dbg(&client->adapter->dev,
 305                         "size out of range (%x) in ioctl I2C_SMBUS.\n",
 306                         data_arg.size);
 307                 return -EINVAL;
 308         }
 309         /* Note that I2C_SMBUS_READ and I2C_SMBUS_WRITE are 0 and 1,
 310            so the check is valid if size==I2C_SMBUS_QUICK too. */
 311         if ((data_arg.read_write != I2C_SMBUS_READ) &&
 312             (data_arg.read_write != I2C_SMBUS_WRITE)) {
 313                 dev_dbg(&client->adapter->dev,
 314                         "read_write out of range (%x) in ioctl I2C_SMBUS.\n",
 315                         data_arg.read_write);
 316                 return -EINVAL;
 317         }
 318
 319         /* Note that command values are always valid! */
 320
 321         if ((data_arg.size == I2C_SMBUS_QUICK) ||
 322             ((data_arg.size == I2C_SMBUS_BYTE) &&
 323             (data_arg.read_write == I2C_SMBUS_WRITE)))
 324                 /* These are special: we do not use data */
 325                 return i2c_smbus_xfer(client->adapter, client->addr,
 326                                       client->flags, data_arg.read_write,
 327                                       data_arg.command, data_arg.size, NULL);
 328
 329         if (data_arg.data == NULL) {
 330                 dev_dbg(&client->adapter->dev,
 331                         "data is NULL pointer in ioctl I2C_SMBUS.\n");
 332                 return -EINVAL;
 333         }
 334
 335         if ((data_arg.size == I2C_SMBUS_BYTE_DATA) ||
 336             (data_arg.size == I2C_SMBUS_BYTE))
 337                 datasize = sizeof(data_arg.data->byte);
 338         else if ((data_arg.size == I2C_SMBUS_WORD_DATA) ||
 339                  (data_arg.size == I2C_SMBUS_PROC_CALL))
 340                 datasize = sizeof(data_arg.data->word);
 341         else /* size == smbus block, i2c block, or block proc. call */
 342                 datasize = sizeof(data_arg.data->block);
 343
 344         if ((data_arg.size == I2C_SMBUS_PROC_CALL) ||
 345             (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) ||
 346             (data_arg.size == I2C_SMBUS_I2C_BLOCK_DATA) ||
 347             (data_arg.read_write == I2C_SMBUS_WRITE)) {
 348                 if (copy_from_user(&temp, data_arg.data, datasize))
 349                         return -EFAULT;
 350         }
 351         if (data_arg.size == I2C_SMBUS_I2C_BLOCK_BROKEN) {
 352                 /* Convert old I2C block commands to the new
 353                    convention. This preserves binary compatibility. */
 354                 data_arg.size = I2C_SMBUS_I2C_BLOCK_DATA;
 355                 if (data_arg.read_write == I2C_SMBUS_READ)
 356                         temp.block[0] = I2C_SMBUS_BLOCK_MAX;
 357         }
 358         res = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
 359               data_arg.read_write, data_arg.command, data_arg.size, &temp);
 360         if (!res && ((data_arg.size == I2C_SMBUS_PROC_CALL) ||
 361                      (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) ||
 362                      (data_arg.read_write == I2C_SMBUS_READ))) {
 363                 if (copy_to_user(data_arg.data, &temp, datasize))
 364                         return -EFAULT;
 365         }
 366         return res;
 367 }
 368
 369 static int i2cdev_ioctl(struct inode *inode, struct file *file,
 370                 unsigned int cmd, unsigned long arg)
 371 {
 372         struct i2c_client *client = (struct i2c_client *)file->private_data;
 373         unsigned long funcs;
 374
 375         dev_dbg(&client->adapter->dev, "ioctl, cmd=0x%02x, arg=0x%02lx\n",
 376                 cmd, arg);
 377
 378         switch ( cmd ) {
 379         case I2C_SLAVE:
 380         case I2C_SLAVE_FORCE:
 381                 /* NOTE:  devices set up to work with "new style" drivers
 382                  * can't use I2C_SLAVE, even when the device node is not
 383                  * bound to a driver.  Only I2C_SLAVE_FORCE will work.
 384                  *
 385                  * Setting the PEC flag here won't affect kernel drivers,
 386                  * which will be using the i2c_client node registered with
 387                  * the driver model core.  Likewise, when that client has
 388                  * the PEC flag already set, the i2c-dev driver won't see
 389                  * (or use) this setting.
 390                  */
 391                 if ((arg > 0x3ff) ||
 392                     (((client->flags & I2C_M_TEN) == 0) && arg > 0x7f))
 393                         return -EINVAL;
 394                 if (cmd == I2C_SLAVE && i2cdev_check_addr(client->adapter, arg))
 395                         return -EBUSY;
 396                 /* REVISIT: address could become busy later */
 397                 client->addr = arg;
 398                 return 0;
 399         case I2C_TENBIT:
 400                 if (arg)
 401                         client->flags |= I2C_M_TEN;
 402                 else
 403                         client->flags &= ~I2C_M_TEN;
 404                 return 0;
 405         case I2C_PEC:
 406                 if (arg)
 407                         client->flags |= I2C_CLIENT_PEC;
 408                 else
 409                         client->flags &= ~I2C_CLIENT_PEC;
 410                 return 0;
 411         case I2C_FUNCS:
 412                 funcs = i2c_get_functionality(client->adapter);
 413                 return put_user(funcs, (unsigned long __user *)arg);
 414
 415         case I2C_RDWR:
 416                 return i2cdev_ioctl_rdrw(client, arg);
 417
 418         case I2C_SMBUS:
 419                 return i2cdev_ioctl_smbus(client, arg);
 420
 421         case I2C_RETRIES:
 422                 client->adapter->retries = arg;
 423                 break;
 424         case I2C_TIMEOUT:
 425                 client->adapter->timeout = arg;
 426                 break;
 427         default:
 428                 /* NOTE:  returning a fault code here could cause trouble
 429                  * in buggy userspace code.  Some old kernel bugs returned
 430                  * zero in this case, and userspace code might accidentally
 431                  * have depended on that bug.
 432                  */
 433                 return -ENOTTY;
 434         }
 435         return 0;
 436 }
 437
 438 static int i2cdev_open(struct inode *inode, struct file *file)
 439 {
 440         unsigned int minor = iminor(inode);
 441         struct i2c_client *client;
 442         struct i2c_adapter *adap;
 443         struct i2c_dev *i2c_dev;
 444
 445         i2c_dev = i2c_dev_get_by_minor(minor);
 446         if (!i2c_dev)
 447                 return -ENODEV;
 448
 449         adap = i2c_get_adapter(i2c_dev->adap->nr);
 450         if (!adap)
 451                 return -ENODEV;
 452
 453         /* This creates an anonymous i2c_client, which may later be
 454          * pointed to some address using I2C_SLAVE or I2C_SLAVE_FORCE.
 455          *
 456          * This client is ** NEVER REGISTERED ** with the driver model
 457          * or I2C core code!!  It just holds private copies of addressing
 458          * information and maybe a PEC flag.
 459          */
 460         client = kzalloc(sizeof(*client), GFP_KERNEL);
 461         if (!client) {
 462                 i2c_put_adapter(adap);
 463                 return -ENOMEM;
 464         }
 465         snprintf(client->name, I2C_NAME_SIZE, "i2c-dev %d", adap->nr);
 466         client->driver = &i2cdev_driver;
 467
 468         client->adapter = adap;
 469         file->private_data = client;
 470
 471         return 0;
 472 }
 473
 474 static int i2cdev_release(struct inode *inode, struct file *file)
 475 {
 476         struct i2c_client *client = file->private_data;
 477
 478         i2c_put_adapter(client->adapter);
 479         kfree(client);
 480         file->private_data = NULL;
 481
 482         return 0;
 483 }
 484
 485 static const struct file_operations i2cdev_fops = {
 486         .owner          = THIS_MODULE,
 487         .llseek         = no_llseek,
 488         .read           = i2cdev_read,
 489         .write          = i2cdev_write,
 490         .ioctl          = i2cdev_ioctl,
 491         .open           = i2cdev_open,
 492         .release        = i2cdev_release,
 493 };
 494
 495 /* ------------------------------------------------------------------------- */
 496
 497 /*
 498  * The legacy "i2cdev_driver" is used primarily to get notifications when
 499  * I2C adapters are added or removed, so that each one gets an i2c_dev
 500  * and is thus made available to userspace driver code.
 501  */
 502
 503 static struct class *i2c_dev_class;
 504
 505 static int i2cdev_attach_adapter(struct i2c_adapter *adap)
 506 {
 507         struct i2c_dev *i2c_dev;
 508         int res;
 509
 510         i2c_dev = get_free_i2c_dev(adap);
 511         if (IS_ERR(i2c_dev))
 512                 return PTR_ERR(i2c_dev);
 513
 514         /* register this i2c device with the driver core */
 515         i2c_dev->dev = device_create(i2c_dev_class, &adap->dev,
 516                                      MKDEV(I2C_MAJOR, adap->nr),
 517                                      "i2c-%d", adap->nr);
 518         if (IS_ERR(i2c_dev->dev)) {
 519                 res = PTR_ERR(i2c_dev->dev);
 520                 goto error;
 521         }
 522         res = device_create_file(i2c_dev->dev, &dev_attr_name);
 523         if (res)
 524                 goto error_destroy;
 525
 526         pr_debug("i2c-dev: adapter [%s] registered as minor %d\n",
 527                  adap->name, adap->nr);
 528         return 0;
 529 error_destroy:
 530         device_destroy(i2c_dev_class, MKDEV(I2C_MAJOR, adap->nr));
 531 error:
 532         return_i2c_dev(i2c_dev);
 533         return res;
 534 }
 535
 536 static int i2cdev_detach_adapter(struct i2c_adapter *adap)
 537 {
 538         struct i2c_dev *i2c_dev;
 539
 540         i2c_dev = i2c_dev_get_by_minor(adap->nr);
 541         if (!i2c_dev) /* attach_adapter must have failed */
 542                 return 0;
 543
 544         device_remove_file(i2c_dev->dev, &dev_attr_name);
 545         return_i2c_dev(i2c_dev);
 546         device_destroy(i2c_dev_class, MKDEV(I2C_MAJOR, adap->nr));
 547
 548         pr_debug("i2c-dev: adapter [%s] unregistered\n", adap->name);
 549         return 0;
 550 }
 551
 552 static int i2cdev_detach_client(struct i2c_client *client)
 553 {
 554         return 0;
 555 }
 556
 557 static struct i2c_driver i2cdev_driver = {
 558         .driver = {
 559                 .name   = "dev_driver",
 560         },
 561         .id             = I2C_DRIVERID_I2CDEV,
 562         .attach_adapter = i2cdev_attach_adapter,
 563         .detach_adapter = i2cdev_detach_adapter,
 564         .detach_client  = i2cdev_detach_client,
 565 };
 566
 567 /* ------------------------------------------------------------------------- */
 568
 569 /*
 570  * module load/unload record keeping
 571  */
 572
 573 static int __init i2c_dev_init(void)
 574 {
 575         int res;
 576
 577         printk(KERN_INFO "i2c /dev entries driver\n");
 578
 579         res = register_chrdev(I2C_MAJOR, "i2c", &i2cdev_fops);
 580         if (res)
 581                 goto out;
 582
 583         i2c_dev_class = class_create(THIS_MODULE, "i2c-dev");
 584         if (IS_ERR(i2c_dev_class))
 585                 goto out_unreg_chrdev;
 586
 587         res = i2c_add_driver(&i2cdev_driver);
 588         if (res)
 589                 goto out_unreg_class;
 590
 591         return 0;
 592
 593 out_unreg_class:
 594         class_destroy(i2c_dev_class);
 595 out_unreg_chrdev:
 596         unregister_chrdev(I2C_MAJOR, "i2c");
 597 out:
 598         printk(KERN_ERR "%s: Driver Initialisation failed\n", __FILE__);
 599         return res;
 600 }
 601
 602 static void __exit i2c_dev_exit(void)
 603 {
 604         i2c_del_driver(&i2cdev_driver);
 605         class_destroy(i2c_dev_class);
 606         unregister_chrdev(I2C_MAJOR,"i2c");
 607 }
 608
 609 MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and "
 610                 "Simon G. Vogl <simon@tk.uni-linz.ac.at>");
 611 MODULE_DESCRIPTION("I2C /dev entries driver");
 612 MODULE_LICENSE("GPL");
 613
 614 module_init(i2c_dev_init);
 615 module_exit(i2c_dev_exit);