drivers/i2c/i2c-core.c

   1 /* i2c-core.c - a device driver for the iic-bus interface                    */
   2 /* ------------------------------------------------------------------------- */
   3 /*   Copyright (C) 1995-99 Simon G. Vogl
   4
   5     This program is free software; you can redistribute it and/or modify
   6     it under the terms of the GNU General Public License as published by
   7     the Free Software Foundation; either version 2 of the License, or
   8     (at your option) any later version.
   9
  10     This program is distributed in the hope that it will be useful,
  11     but WITHOUT ANY WARRANTY; without even the implied warranty of
  12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13     GNU General Public License for more details.
  14
  15     You should have received a copy of the GNU General Public License
  16     along with this program; if not, write to the Free Software
  17     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.                */
  18 /* ------------------------------------------------------------------------- */
  19
  20 /* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi>.
  21    All SMBus-related things are written by Frodo Looijaard <frodol@dds.nl>
  22    SMBus 2.0 support by Mark Studebaker <mdsxyz123@yahoo.com>                */
  23
  24 #include <linux/config.h>
  25 #include <linux/module.h>
  26 #include <linux/kernel.h>
  27 #include <linux/errno.h>
  28 #include <linux/slab.h>
  29 #include <linux/i2c.h>
  30 #include <linux/init.h>
  31 #include <linux/idr.h>
  32 #include <linux/seq_file.h>
  33 #include <asm/uaccess.h>
  34
  35
  36 static LIST_HEAD(adapters);
  37 static LIST_HEAD(drivers);
  38 static DECLARE_MUTEX(core_lists);
  39 static DEFINE_IDR(i2c_adapter_idr);
  40
  41 int i2c_device_probe(struct device *dev)
  42 {
  43         return -ENODEV;
  44 }
  45
  46 int i2c_device_remove(struct device *dev)
  47 {
  48         return 0;
  49 }
  50
  51 static void i2c_adapter_dev_release(struct device *dev)
  52 {
  53         struct i2c_adapter *adap = dev_to_i2c_adapter(dev);
  54         complete(&adap->dev_released);
  55 }
  56
  57 static struct device_driver i2c_adapter_driver = {
  58         .name = "i2c_adapter",
  59         .bus = &i2c_bus_type,
  60         .probe = i2c_device_probe,
  61         .remove = i2c_device_remove,
  62 };
  63
  64 static void i2c_adapter_class_dev_release(struct class_device *dev)
  65 {
  66         struct i2c_adapter *adap = class_dev_to_i2c_adapter(dev);
  67         complete(&adap->class_dev_released);
  68 }
  69
  70 static struct class i2c_adapter_class = {
  71         .name =         "i2c-adapter",
  72         .release =      &i2c_adapter_class_dev_release,
  73 };
  74
  75 static ssize_t show_adapter_name(struct device *dev, char *buf)
  76 {
  77         struct i2c_adapter *adap = dev_to_i2c_adapter(dev);
  78         return sprintf(buf, "%s\n", adap->name);
  79 }
  80 static DEVICE_ATTR(name, S_IRUGO, show_adapter_name, NULL);
  81
  82
  83 static void i2c_client_release(struct device *dev)
  84 {
  85         struct i2c_client *client = to_i2c_client(dev);
  86         complete(&client->released);
  87 }
  88
  89 static ssize_t show_client_name(struct device *dev, char *buf)
  90 {
  91         struct i2c_client *client = to_i2c_client(dev);
  92         return sprintf(buf, "%s\n", client->name);
  93 }
  94
  95 /*
  96  * We can't use the DEVICE_ATTR() macro here as we want the same filename for a
  97  * different type of a device.  So beware if the DEVICE_ATTR() macro ever
  98  * changes, this definition will also have to change.
  99  */
 100 static struct device_attribute dev_attr_client_name = {
 101         .attr   = {.name = "name", .mode = S_IRUGO, .owner = THIS_MODULE },
 102         .show   = &show_client_name,
 103 };
 104
 105
 106 /* ---------------------------------------------------
 107  * registering functions
 108  * ---------------------------------------------------
 109  */
 110
 111 /* -----
 112  * i2c_add_adapter is called from within the algorithm layer,
 113  * when a new hw adapter registers. A new device is register to be
 114  * available for clients.
 115  */
 116 int i2c_add_adapter(struct i2c_adapter *adap)
 117 {
 118         int id, res = 0;
 119         struct list_head   *item;
 120         struct i2c_driver  *driver;
 121
 122         down(&core_lists);
 123
 124         if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0) {
 125                 res = -ENOMEM;
 126                 goto out_unlock;
 127         }
 128
 129         res = idr_get_new(&i2c_adapter_idr, NULL, &id);
 130         if (res < 0) {
 131                 if (res == -EAGAIN)
 132                         res = -ENOMEM;
 133                 goto out_unlock;
 134         }
 135
 136         adap->nr =  id & MAX_ID_MASK;
 137         init_MUTEX(&adap->bus_lock);
 138         init_MUTEX(&adap->clist_lock);
 139         list_add_tail(&adap->list,&adapters);
 140         INIT_LIST_HEAD(&adap->clients);
 141
 142         /* Add the adapter to the driver core.
 143          * If the parent pointer is not set up,
 144          * we add this adapter to the host bus.
 145          */
 146         if (adap->dev.parent == NULL)
 147                 adap->dev.parent = &platform_bus;
 148         sprintf(adap->dev.bus_id, "i2c-%d", adap->nr);
 149         adap->dev.driver = &i2c_adapter_driver;
 150         adap->dev.release = &i2c_adapter_dev_release;
 151         device_register(&adap->dev);
 152         device_create_file(&adap->dev, &dev_attr_name);
 153
 154         /* Add this adapter to the i2c_adapter class */
 155         memset(&adap->class_dev, 0x00, sizeof(struct class_device));
 156         adap->class_dev.dev = &adap->dev;
 157         adap->class_dev.class = &i2c_adapter_class;
 158         strlcpy(adap->class_dev.class_id, adap->dev.bus_id, BUS_ID_SIZE);
 159         class_device_register(&adap->class_dev);
 160
 161         /* inform drivers of new adapters */
 162         list_for_each(item,&drivers) {
 163                 driver = list_entry(item, struct i2c_driver, list);
 164                 if (driver->flags & I2C_DF_NOTIFY)
 165                         /* We ignore the return code; if it fails, too bad */
 166                         driver->attach_adapter(adap);
 167         }
 168
 169         dev_dbg(&adap->dev, "registered as adapter #%d\n", adap->nr);
 170
 171 out_unlock:
 172         up(&core_lists);
 173         return res;
 174 }
 175
 176
 177 int i2c_del_adapter(struct i2c_adapter *adap)
 178 {
 179         struct list_head  *item, *_n;
 180         struct i2c_adapter *adap_from_list;
 181         struct i2c_driver *driver;
 182         struct i2c_client *client;
 183         int res = 0;
 184
 185         down(&core_lists);
 186
 187         /* First make sure that this adapter was ever added */
 188         list_for_each_entry(adap_from_list, &adapters, list) {
 189                 if (adap_from_list == adap)
 190                         break;
 191         }
 192         if (adap_from_list != adap) {
 193                 pr_debug("I2C: Attempting to delete an unregistered "
 194                          "adapter\n");
 195                 res = -EINVAL;
 196                 goto out_unlock;
 197         }
 198
 199         list_for_each(item,&drivers) {
 200                 driver = list_entry(item, struct i2c_driver, list);
 201                 if (driver->detach_adapter)
 202                         if ((res = driver->detach_adapter(adap))) {
 203                                 dev_warn(&adap->dev, "can't detach adapter "
 204                                          "while detaching driver %s: driver not "
 205                                          "detached!", driver->name);
 206                                 goto out_unlock;
 207                         }
 208         }
 209
 210         /* detach any active clients. This must be done first, because
 211          * it can fail; in which case we give upp. */
 212         list_for_each_safe(item, _n, &adap->clients) {
 213                 client = list_entry(item, struct i2c_client, list);
 214
 215                 /* detaching devices is unconditional of the set notify
 216                  * flag, as _all_ clients that reside on the adapter
 217                  * must be deleted, as this would cause invalid states.
 218                  */
 219                 if ((res=client->driver->detach_client(client))) {
 220                         dev_err(&adap->dev, "adapter not "
 221                                 "unregistered, because client at "
 222                                 "address %02x can't be detached. ",
 223                                 client->addr);
 224                         goto out_unlock;
 225                 }
 226         }
 227
 228         /* clean up the sysfs representation */
 229         init_completion(&adap->dev_released);
 230         init_completion(&adap->class_dev_released);
 231         class_device_unregister(&adap->class_dev);
 232         device_remove_file(&adap->dev, &dev_attr_name);
 233         device_unregister(&adap->dev);
 234         list_del(&adap->list);
 235
 236         /* wait for sysfs to drop all references */
 237         wait_for_completion(&adap->dev_released);
 238         wait_for_completion(&adap->class_dev_released);
 239
 240         /* free dynamically allocated bus id */
 241         idr_remove(&i2c_adapter_idr, adap->nr);
 242
 243         dev_dbg(&adap->dev, "adapter unregistered\n");
 244
 245  out_unlock:
 246         up(&core_lists);
 247         return res;
 248 }
 249
 250
 251 /* -----
 252  * What follows is the "upwards" interface: commands for talking to clients,
 253  * which implement the functions to access the physical information of the
 254  * chips.
 255  */
 256
 257 int i2c_add_driver(struct i2c_driver *driver)
 258 {
 259         struct list_head   *item;
 260         struct i2c_adapter *adapter;
 261         int res = 0;
 262
 263         down(&core_lists);
 264
 265         /* add the driver to the list of i2c drivers in the driver core */
 266         driver->driver.name = driver->name;
 267         driver->driver.bus = &i2c_bus_type;
 268         driver->driver.probe = i2c_device_probe;
 269         driver->driver.remove = i2c_device_remove;
 270
 271         res = driver_register(&driver->driver);
 272         if (res)
 273                 goto out_unlock;
 274
 275         list_add_tail(&driver->list,&drivers);
 276         pr_debug("i2c-core: driver %s registered.\n", driver->name);
 277
 278         /* now look for instances of driver on our adapters */
 279         if (driver->flags & I2C_DF_NOTIFY) {
 280                 list_for_each(item,&adapters) {
 281                         adapter = list_entry(item, struct i2c_adapter, list);
 282                         driver->attach_adapter(adapter);
 283                 }
 284         }
 285
 286  out_unlock:
 287         up(&core_lists);
 288         return res;
 289 }
 290
 291 int i2c_del_driver(struct i2c_driver *driver)
 292 {
 293         struct list_head   *item1, *item2, *_n;
 294         struct i2c_client  *client;
 295         struct i2c_adapter *adap;
 296
 297         int res = 0;
 298
 299         down(&core_lists);
 300
 301         /* Have a look at each adapter, if clients of this driver are still
 302          * attached. If so, detach them to be able to kill the driver
 303          * afterwards.
 304          */
 305         pr_debug("i2c-core: unregister_driver - looking for clients.\n");
 306         /* removing clients does not depend on the notify flag, else
 307          * invalid operation might (will!) result, when using stale client
 308          * pointers.
 309          */
 310         list_for_each(item1,&adapters) {
 311                 adap = list_entry(item1, struct i2c_adapter, list);
 312                 dev_dbg(&adap->dev, "examining adapter\n");
 313                 if (driver->detach_adapter) {
 314                         if ((res = driver->detach_adapter(adap))) {
 315                                 dev_warn(&adap->dev, "while unregistering "
 316                                        "dummy driver %s, adapter could "
 317                                        "not be detached properly; driver "
 318                                        "not unloaded!",driver->name);
 319                                 goto out_unlock;
 320                         }
 321                 } else {
 322                         list_for_each_safe(item2, _n, &adap->clients) {
 323                                 client = list_entry(item2, struct i2c_client, list);
 324                                 if (client->driver != driver)
 325                                         continue;
 326                                 pr_debug("i2c-core.o: detaching client %s:\n", client->name);
 327                                 if ((res = driver->detach_client(client))) {
 328                                         dev_err(&adap->dev, "while "
 329                                                 "unregistering driver "
 330                                                 "`%s', the client at "
 331                                                 "address %02x of "
 332                                                 "adapter could not "
 333                                                 "be detached; driver "
 334                                                 "not unloaded!",
 335                                                 driver->name,
 336                                                 client->addr);
 337                                         goto out_unlock;
 338                                 }
 339                         }
 340                 }
 341         }
 342
 343         driver_unregister(&driver->driver);
 344         list_del(&driver->list);
 345         pr_debug("i2c-core: driver unregistered: %s\n", driver->name);
 346
 347  out_unlock:
 348         up(&core_lists);
 349         return 0;
 350 }
 351
 352 static int __i2c_check_addr(struct i2c_adapter *adapter, unsigned int addr)
 353 {
 354         struct list_head   *item;
 355         struct i2c_client  *client;
 356
 357         list_for_each(item,&adapter->clients) {
 358                 client = list_entry(item, struct i2c_client, list);
 359                 if (client->addr == addr)
 360                         return -EBUSY;
 361         }
 362         return 0;
 363 }
 364
 365 int i2c_check_addr(struct i2c_adapter *adapter, int addr)
 366 {
 367         int rval;
 368
 369         down(&adapter->clist_lock);
 370         rval = __i2c_check_addr(adapter, addr);
 371         up(&adapter->clist_lock);
 372
 373         return rval;
 374 }
 375
 376 int i2c_attach_client(struct i2c_client *client)
 377 {
 378         struct i2c_adapter *adapter = client->adapter;
 379
 380         down(&adapter->clist_lock);
 381         if (__i2c_check_addr(client->adapter, client->addr)) {
 382                 up(&adapter->clist_lock);
 383                 return -EBUSY;
 384         }
 385         list_add_tail(&client->list,&adapter->clients);
 386         up(&adapter->clist_lock);
 387
 388         if (adapter->client_register)  {
 389                 if (adapter->client_register(client))  {
 390                         dev_warn(&adapter->dev, "warning: client_register "
 391                                 "seems to have failed for client %02x\n",
 392                                 client->addr);
 393                 }
 394         }
 395
 396         dev_dbg(&adapter->dev, "client [%s] registered to adapter\n",
 397                 client->name);
 398
 399         if (client->flags & I2C_CLIENT_ALLOW_USE)
 400                 client->usage_count = 0;
 401
 402         client->dev.parent = &client->adapter->dev;
 403         client->dev.driver = &client->driver->driver;
 404         client->dev.bus = &i2c_bus_type;
 405         client->dev.release = &i2c_client_release;
 406
 407         snprintf(&client->dev.bus_id[0], sizeof(client->dev.bus_id),
 408                 "%d-%04x", i2c_adapter_id(adapter), client->addr);
 409         pr_debug("registering %s\n", client->dev.bus_id);
 410         device_register(&client->dev);
 411         device_create_file(&client->dev, &dev_attr_client_name);
 412
 413         return 0;
 414 }
 415
 416
 417 int i2c_detach_client(struct i2c_client *client)
 418 {
 419         struct i2c_adapter *adapter = client->adapter;
 420         int res = 0;
 421
 422         if ((client->flags & I2C_CLIENT_ALLOW_USE) && (client->usage_count > 0))
 423                 return -EBUSY;
 424
 425         if (adapter->client_unregister)  {
 426                 res = adapter->client_unregister(client);
 427                 if (res) {
 428                         dev_err(&client->dev,
 429                                "client_unregister [%s] failed, "
 430                                "client not detached", client->name);
 431                         goto out;
 432                 }
 433         }
 434
 435         down(&adapter->clist_lock);
 436         list_del(&client->list);
 437         init_completion(&client->released);
 438         device_remove_file(&client->dev, &dev_attr_client_name);
 439         device_unregister(&client->dev);
 440         up(&adapter->clist_lock);
 441         wait_for_completion(&client->released);
 442
 443  out:
 444         return res;
 445 }
 446
 447 static int i2c_inc_use_client(struct i2c_client *client)
 448 {
 449
 450         if (!try_module_get(client->driver->owner))
 451                 return -ENODEV;
 452         if (!try_module_get(client->adapter->owner)) {
 453                 module_put(client->driver->owner);
 454                 return -ENODEV;
 455         }
 456
 457         return 0;
 458 }
 459
 460 static void i2c_dec_use_client(struct i2c_client *client)
 461 {
 462         module_put(client->driver->owner);
 463         module_put(client->adapter->owner);
 464 }
 465
 466 int i2c_use_client(struct i2c_client *client)
 467 {
 468         int ret;
 469
 470         ret = i2c_inc_use_client(client);
 471         if (ret)
 472                 return ret;
 473
 474         if (client->flags & I2C_CLIENT_ALLOW_USE) {
 475                 if (client->flags & I2C_CLIENT_ALLOW_MULTIPLE_USE)
 476                         client->usage_count++;
 477                 else if (client->usage_count > 0)
 478                         goto busy;
 479                 else
 480                         client->usage_count++;
 481         }
 482
 483         return 0;
 484  busy:
 485         i2c_dec_use_client(client);
 486         return -EBUSY;
 487 }
 488
 489 int i2c_release_client(struct i2c_client *client)
 490 {
 491         if(client->flags & I2C_CLIENT_ALLOW_USE) {
 492                 if(client->usage_count>0)
 493                         client->usage_count--;
 494                 else {
 495                         pr_debug("i2c-core: %s used one too many times\n",
 496                                 __FUNCTION__);
 497                         return -EPERM;
 498                 }
 499         }
 500
 501         i2c_dec_use_client(client);
 502
 503         return 0;
 504 }
 505
 506 void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg)
 507 {
 508         struct list_head  *item;
 509         struct i2c_client *client;
 510
 511         down(&adap->clist_lock);
 512         list_for_each(item,&adap->clients) {
 513                 client = list_entry(item, struct i2c_client, list);
 514                 if (!try_module_get(client->driver->owner))
 515                         continue;
 516                 if (NULL != client->driver->command) {
 517                         up(&adap->clist_lock);
 518                         client->driver->command(client,cmd,arg);
 519                         down(&adap->clist_lock);
 520                 }
 521                 module_put(client->driver->owner);
 522        }
 523        up(&adap->clist_lock);
 524 }
 525
 526
 527 /* match always succeeds, as we want the probe() to tell if we really accept this match */
 528 static int i2c_device_match(struct device *dev, struct device_driver *drv)
 529 {
 530         return 1;
 531 }
 532
 533 static int i2c_bus_suspend(struct device * dev, u32 state)
 534 {
 535         int rc = 0;
 536
 537         if (dev->driver && dev->driver->suspend)
 538                 rc = dev->driver->suspend(dev,state,0);
 539         return rc;
 540 }
 541
 542 static int i2c_bus_resume(struct device * dev)
 543 {
 544         int rc = 0;
 545
 546         if (dev->driver && dev->driver->resume)
 547                 rc = dev->driver->resume(dev,0);
 548         return rc;
 549 }
 550
 551 struct bus_type i2c_bus_type = {
 552         .name =         "i2c",
 553         .match =        i2c_device_match,
 554         .suspend =      i2c_bus_suspend,
 555         .resume =       i2c_bus_resume,
 556 };
 557
 558 static int __init i2c_init(void)
 559 {
 560         int retval;
 561
 562         retval = bus_register(&i2c_bus_type);
 563         if (retval)
 564                 return retval;
 565         retval = driver_register(&i2c_adapter_driver);
 566         if (retval)
 567                 return retval;
 568         return class_register(&i2c_adapter_class);
 569 }
 570
 571 static void __exit i2c_exit(void)
 572 {
 573         class_unregister(&i2c_adapter_class);
 574         driver_unregister(&i2c_adapter_driver);
 575         bus_unregister(&i2c_bus_type);
 576 }
 577
 578 subsys_initcall(i2c_init);
 579 module_exit(i2c_exit);
 580
 581 /* ----------------------------------------------------
 582  * the functional interface to the i2c busses.
 583  * ----------------------------------------------------
 584  */
 585
 586 int i2c_transfer(struct i2c_adapter * adap, struct i2c_msg msgs[],int num)
 587 {
 588         int ret;
 589
 590         if (adap->algo->master_xfer) {
 591                 dev_dbg(&adap->dev, "master_xfer: with %d msgs.\n", num);
 592
 593                 down(&adap->bus_lock);
 594                 ret = adap->algo->master_xfer(adap,msgs,num);
 595                 up(&adap->bus_lock);
 596
 597                 return ret;
 598         } else {
 599                 dev_dbg(&adap->dev, "I2C level transfers not supported\n");
 600                 return -ENOSYS;
 601         }
 602 }
 603
 604 int i2c_master_send(struct i2c_client *client,const char *buf ,int count)
 605 {
 606         int ret;
 607         struct i2c_adapter *adap=client->adapter;
 608         struct i2c_msg msg;
 609
 610         if (client->adapter->algo->master_xfer) {
 611                 msg.addr   = client->addr;
 612                 msg.flags = client->flags & I2C_M_TEN;
 613                 msg.len = count;
 614                 msg.buf = (char *)buf;
 615
 616                 dev_dbg(&client->adapter->dev, "master_send: writing %d bytes.\n",
 617                         count);
 618
 619                 down(&adap->bus_lock);
 620                 ret = adap->algo->master_xfer(adap,&msg,1);
 621                 up(&adap->bus_lock);
 622
 623                 /* if everything went ok (i.e. 1 msg transmitted), return #bytes
 624                  * transmitted, else error code.
 625                  */
 626                 return (ret == 1 )? count : ret;
 627         } else {
 628                 dev_err(&client->adapter->dev, "I2C level transfers not supported\n");
 629                 return -ENOSYS;
 630         }
 631 }
 632
 633 int i2c_master_recv(struct i2c_client *client, char *buf ,int count)
 634 {
 635         struct i2c_adapter *adap=client->adapter;
 636         struct i2c_msg msg;
 637         int ret;
 638         if (client->adapter->algo->master_xfer) {
 639                 msg.addr   = client->addr;
 640                 msg.flags = client->flags & I2C_M_TEN;
 641                 msg.flags |= I2C_M_RD;
 642                 msg.len = count;
 643                 msg.buf = buf;
 644
 645                 dev_dbg(&client->adapter->dev, "master_recv: reading %d bytes.\n",
 646                         count);
 647
 648                 down(&adap->bus_lock);
 649                 ret = adap->algo->master_xfer(adap,&msg,1);
 650                 up(&adap->bus_lock);
 651
 652                 dev_dbg(&client->adapter->dev, "master_recv: return:%d (count:%d, addr:0x%02x)\n",
 653                         ret, count, client->addr);
 654
 655                 /* if everything went ok (i.e. 1 msg transmitted), return #bytes
 656                 * transmitted, else error code.
 657                 */
 658                 return (ret == 1 )? count : ret;
 659         } else {
 660                 dev_err(&client->adapter->dev, "I2C level transfers not supported\n");
 661                 return -ENOSYS;
 662         }
 663 }
 664
 665
 666 int i2c_control(struct i2c_client *client,
 667         unsigned int cmd, unsigned long arg)
 668 {
 669         int ret = 0;
 670         struct i2c_adapter *adap = client->adapter;
 671
 672         dev_dbg(&client->adapter->dev, "i2c ioctl, cmd: 0x%x, arg: %#lx\n", cmd, arg);
 673         switch (cmd) {
 674                 case I2C_RETRIES:
 675                         adap->retries = arg;
 676                         break;
 677                 case I2C_TIMEOUT:
 678                         adap->timeout = arg;
 679                         break;
 680                 default:
 681                         if (adap->algo->algo_control!=NULL)
 682                                 ret = adap->algo->algo_control(adap,cmd,arg);
 683         }
 684         return ret;
 685 }
 686
 687 /* ----------------------------------------------------
 688  * the i2c address scanning function
 689  * Will not work for 10-bit addresses!
 690  * ----------------------------------------------------
 691  */
 692 int i2c_probe(struct i2c_adapter *adapter,
 693               struct i2c_client_address_data *address_data,
 694               int (*found_proc) (struct i2c_adapter *, int, int))
 695 {
 696         int addr,i,found,err;
 697         int adap_id = i2c_adapter_id(adapter);
 698
 699         /* Forget it if we can't probe using SMBUS_QUICK */
 700         if (! i2c_check_functionality(adapter,I2C_FUNC_SMBUS_QUICK))
 701                 return -1;
 702
 703         for (addr = 0x00; addr <= 0x7f; addr++) {
 704
 705                 /* Skip if already in use */
 706                 if (i2c_check_addr(adapter,addr))
 707                         continue;
 708
 709                 /* If it is in one of the force entries, we don't do any detection
 710                    at all */
 711                 found = 0;
 712
 713                 for (i = 0; !found && (address_data->force[i] != I2C_CLIENT_END); i += 3) {
 714                         if (((adap_id == address_data->force[i]) ||
 715                              (address_data->force[i] == ANY_I2C_BUS)) &&
 716                              (addr == address_data->force[i+1])) {
 717                                 dev_dbg(&adapter->dev, "found force parameter for adapter %d, addr %04x\n",
 718                                         adap_id, addr);
 719                                 if ((err = found_proc(adapter,addr,0)))
 720                                         return err;
 721                                 found = 1;
 722                         }
 723                 }
 724                 if (found)
 725                         continue;
 726
 727                 /* If this address is in one of the ignores, we can forget about
 728                    it right now */
 729                 for (i = 0;
 730                      !found && (address_data->ignore[i] != I2C_CLIENT_END);
 731                      i += 2) {
 732                         if (((adap_id == address_data->ignore[i]) ||
 733                             ((address_data->ignore[i] == ANY_I2C_BUS))) &&
 734                             (addr == address_data->ignore[i+1])) {
 735                                 dev_dbg(&adapter->dev, "found ignore parameter for adapter %d, "
 736                                         "addr %04x\n", adap_id ,addr);
 737                                 found = 1;
 738                         }
 739                 }
 740                 for (i = 0;
 741                      !found && (address_data->ignore_range[i] != I2C_CLIENT_END);
 742                      i += 3) {
 743                         if (((adap_id == address_data->ignore_range[i]) ||
 744                             ((address_data->ignore_range[i]==ANY_I2C_BUS))) &&
 745                             (addr >= address_data->ignore_range[i+1]) &&
 746                             (addr <= address_data->ignore_range[i+2])) {
 747                                 dev_dbg(&adapter->dev, "found ignore_range parameter for adapter %d, "
 748                                         "addr %04x\n", adap_id,addr);
 749                                 found = 1;
 750                         }
 751                 }
 752                 if (found)
 753                         continue;
 754
 755                 /* Now, we will do a detection, but only if it is in the normal or
 756                    probe entries */
 757                 for (i = 0;
 758                      !found && (address_data->normal_i2c[i] != I2C_CLIENT_END);
 759                      i += 1) {
 760                         if (addr == address_data->normal_i2c[i]) {
 761                                 found = 1;
 762                                 dev_dbg(&adapter->dev, "found normal i2c entry for adapter %d, "
 763                                         "addr %02x\n", adap_id, addr);
 764                         }
 765                 }
 766
 767                 for (i = 0;
 768                      !found && (address_data->normal_i2c_range[i] != I2C_CLIENT_END);
 769                      i += 2) {
 770                         if ((addr >= address_data->normal_i2c_range[i]) &&
 771                             (addr <= address_data->normal_i2c_range[i+1])) {
 772                                 found = 1;
 773                                 dev_dbg(&adapter->dev, "found normal i2c_range entry for adapter %d, "
 774                                         "addr %04x\n", adap_id,addr);
 775                         }
 776                 }
 777
 778                 for (i = 0;
 779                      !found && (address_data->probe[i] != I2C_CLIENT_END);
 780                      i += 2) {
 781                         if (((adap_id == address_data->probe[i]) ||
 782                             ((address_data->probe[i] == ANY_I2C_BUS))) &&
 783                             (addr == address_data->probe[i+1])) {
 784                                 found = 1;
 785                                 dev_dbg(&adapter->dev, "found probe parameter for adapter %d, "
 786                                         "addr %04x\n", adap_id,addr);
 787                         }
 788                 }
 789                 for (i = 0;
 790                      !found && (address_data->probe_range[i] != I2C_CLIENT_END);
 791                      i += 3) {
 792                         if (((adap_id == address_data->probe_range[i]) ||
 793                            (address_data->probe_range[i] == ANY_I2C_BUS)) &&
 794                            (addr >= address_data->probe_range[i+1]) &&
 795                            (addr <= address_data->probe_range[i+2])) {
 796                                 found = 1;
 797                                 dev_dbg(&adapter->dev, "found probe_range parameter for adapter %d, "
 798                                         "addr %04x\n", adap_id,addr);
 799                         }
 800                 }
 801                 if (!found)
 802                         continue;
 803
 804                 /* OK, so we really should examine this address. First check
 805                    whether there is some client here at all! */
 806                 if (i2c_smbus_xfer(adapter,addr,0,0,0,I2C_SMBUS_QUICK,NULL) >= 0)
 807                         if ((err = found_proc(adapter,addr,-1)))
 808                                 return err;
 809         }
 810         return 0;
 811 }
 812
 813 /*
 814  * return id number for a specific adapter
 815  */
 816 int i2c_adapter_id(struct i2c_adapter *adap)
 817 {
 818         return adap->nr;
 819 }
 820
 821 struct i2c_adapter* i2c_get_adapter(int id)
 822 {
 823         struct list_head   *item;
 824         struct i2c_adapter *adapter;
 825
 826         down(&core_lists);
 827         list_for_each(item,&adapters) {
 828                 adapter = list_entry(item, struct i2c_adapter, list);
 829                 if (id == adapter->nr &&
 830                     try_module_get(adapter->owner)) {
 831                         up(&core_lists);
 832                         return adapter;
 833                 }
 834         }
 835         up(&core_lists);
 836         return NULL;
 837 }
 838
 839 void i2c_put_adapter(struct i2c_adapter *adap)
 840 {
 841         module_put(adap->owner);
 842 }
 843
 844 /* The SMBus parts */
 845
 846 #define POLY    (0x1070U << 3)
 847 static u8
 848 crc8(u16 data)
 849 {
 850         int i;
 851
 852         for(i = 0; i < 8; i++) {
 853                 if (data & 0x8000)
 854                         data = data ^ POLY;
 855                 data = data << 1;
 856         }
 857         return (u8)(data >> 8);
 858 }
 859
 860 /* CRC over count bytes in the first array plus the bytes in the rest
 861    array if it is non-null. rest[0] is the (length of rest) - 1
 862    and is included. */
 863 u8 i2c_smbus_partial_pec(u8 crc, int count, u8 *first, u8 *rest)
 864 {
 865         int i;
 866
 867         for(i = 0; i < count; i++)
 868                 crc = crc8((crc ^ first[i]) << 8);
 869         if(rest != NULL)
 870                 for(i = 0; i <= rest[0]; i++)
 871                         crc = crc8((crc ^ rest[i]) << 8);
 872         return crc;
 873 }
 874
 875 u8 i2c_smbus_pec(int count, u8 *first, u8 *rest)
 876 {
 877         return i2c_smbus_partial_pec(0, count, first, rest);
 878 }
 879
 880 /* Returns new "size" (transaction type)
 881    Note that we convert byte to byte_data and byte_data to word_data
 882    rather than invent new xxx_PEC transactions. */
 883 int i2c_smbus_add_pec(u16 addr, u8 command, int size,
 884                       union i2c_smbus_data *data)
 885 {
 886         u8 buf[3];
 887
 888         buf[0] = addr << 1;
 889         buf[1] = command;
 890         switch(size) {
 891                 case I2C_SMBUS_BYTE:
 892                         data->byte = i2c_smbus_pec(2, buf, NULL);
 893                         size = I2C_SMBUS_BYTE_DATA;
 894                         break;
 895                 case I2C_SMBUS_BYTE_DATA:
 896                         buf[2] = data->byte;
 897                         data->word = buf[2] ||
 898                                     (i2c_smbus_pec(3, buf, NULL) << 8);
 899                         size = I2C_SMBUS_WORD_DATA;
 900                         break;
 901                 case I2C_SMBUS_WORD_DATA:
 902                         /* unsupported */
 903                         break;
 904                 case I2C_SMBUS_BLOCK_DATA:
 905                         data->block[data->block[0] + 1] =
 906                                      i2c_smbus_pec(2, buf, data->block);
 907                         size = I2C_SMBUS_BLOCK_DATA_PEC;
 908                         break;
 909         }
 910         return size;
 911 }
 912
 913 int i2c_smbus_check_pec(u16 addr, u8 command, int size, u8 partial,
 914                         union i2c_smbus_data *data)
 915 {
 916         u8 buf[3], rpec, cpec;
 917
 918         buf[1] = command;
 919         switch(size) {
 920                 case I2C_SMBUS_BYTE_DATA:
 921                         buf[0] = (addr << 1) | 1;
 922                         cpec = i2c_smbus_pec(2, buf, NULL);
 923                         rpec = data->byte;
 924                         break;
 925                 case I2C_SMBUS_WORD_DATA:
 926                         buf[0] = (addr << 1) | 1;
 927                         buf[2] = data->word & 0xff;
 928                         cpec = i2c_smbus_pec(3, buf, NULL);
 929                         rpec = data->word >> 8;
 930                         break;
 931                 case I2C_SMBUS_WORD_DATA_PEC:
 932                         /* unsupported */
 933                         cpec = rpec = 0;
 934                         break;
 935                 case I2C_SMBUS_PROC_CALL_PEC:
 936                         /* unsupported */
 937                         cpec = rpec = 0;
 938                         break;
 939                 case I2C_SMBUS_BLOCK_DATA_PEC:
 940                         buf[0] = (addr << 1);
 941                         buf[2] = (addr << 1) | 1;
 942                         cpec = i2c_smbus_pec(3, buf, data->block);
 943                         rpec = data->block[data->block[0] + 1];
 944                         break;
 945                 case I2C_SMBUS_BLOCK_PROC_CALL_PEC:
 946                         buf[0] = (addr << 1) | 1;
 947                         rpec = i2c_smbus_partial_pec(partial, 1,
 948                                                      buf, data->block);
 949                         cpec = data->block[data->block[0] + 1];
 950                         break;
 951                 default:
 952                         cpec = rpec = 0;
 953                         break;
 954         }
 955         if (rpec != cpec) {
 956                 pr_debug("i2c-core: Bad PEC 0x%02x vs. 0x%02x\n",
 957                         rpec, cpec);
 958                 return -1;
 959         }
 960         return 0;
 961 }
 962
 963 s32 i2c_smbus_write_quick(struct i2c_client *client, u8 value)
 964 {
 965         return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
 966                               value,0,I2C_SMBUS_QUICK,NULL);
 967 }
 968
 969 s32 i2c_smbus_read_byte(struct i2c_client *client)
 970 {
 971         union i2c_smbus_data data;
 972         if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
 973                            I2C_SMBUS_READ,0,I2C_SMBUS_BYTE, &data))
 974                 return -1;
 975         else
 976                 return 0x0FF & data.byte;
 977 }
 978
 979 s32 i2c_smbus_write_byte(struct i2c_client *client, u8 value)
 980 {
 981         union i2c_smbus_data data;      /* only for PEC */
 982         return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
 983                               I2C_SMBUS_WRITE,value, I2C_SMBUS_BYTE,&data);
 984 }
 985
 986 s32 i2c_smbus_read_byte_data(struct i2c_client *client, u8 command)
 987 {
 988         union i2c_smbus_data data;
 989         if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
 990                            I2C_SMBUS_READ,command, I2C_SMBUS_BYTE_DATA,&data))
 991                 return -1;
 992         else
 993                 return 0x0FF & data.byte;
 994 }
 995
 996 s32 i2c_smbus_write_byte_data(struct i2c_client *client, u8 command, u8 value)
 997 {
 998         union i2c_smbus_data data;
 999         data.byte = value;
1000         return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
1001                               I2C_SMBUS_WRITE,command,
1002                               I2C_SMBUS_BYTE_DATA,&data);
1003 }
1004
1005 s32 i2c_smbus_read_word_data(struct i2c_client *client, u8 command)
1006 {
1007         union i2c_smbus_data data;
1008         if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
1009                            I2C_SMBUS_READ,command, I2C_SMBUS_WORD_DATA, &data))
1010                 return -1;
1011         else
1012                 return 0x0FFFF & data.word;
1013 }
1014
1015 s32 i2c_smbus_write_word_data(struct i2c_client *client, u8 command, u16 value)
1016 {
1017         union i2c_smbus_data data;
1018         data.word = value;
1019         return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
1020                               I2C_SMBUS_WRITE,command,
1021                               I2C_SMBUS_WORD_DATA,&data);
1022 }
1023
1024 s32 i2c_smbus_write_block_data(struct i2c_client *client, u8 command,
1025                                u8 length, u8 *values)
1026 {
1027         union i2c_smbus_data data;
1028         int i;
1029         if (length > I2C_SMBUS_BLOCK_MAX)
1030                 length = I2C_SMBUS_BLOCK_MAX;
1031         for (i = 1; i <= length; i++)
1032                 data.block[i] = values[i-1];
1033         data.block[0] = length;
1034         return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
1035                               I2C_SMBUS_WRITE,command,
1036                               I2C_SMBUS_BLOCK_DATA,&data);
1037 }
1038
1039 /* Returns the number of read bytes */
1040 s32 i2c_smbus_read_i2c_block_data(struct i2c_client *client, u8 command, u8 *values)
1041 {
1042         union i2c_smbus_data data;
1043         int i;
1044         if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
1045                               I2C_SMBUS_READ,command,
1046                               I2C_SMBUS_I2C_BLOCK_DATA,&data))
1047                 return -1;
1048         else {
1049                 for (i = 1; i <= data.block[0]; i++)
1050                         values[i-1] = data.block[i];
1051                 return data.block[0];
1052         }
1053 }
1054
1055 /* Simulate a SMBus command using the i2c protocol
1056    No checking of parameters is done!  */
1057 static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr,
1058                                    unsigned short flags,
1059                                    char read_write, u8 command, int size,
1060                                    union i2c_smbus_data * data)
1061 {
1062         /* So we need to generate a series of msgs. In the case of writing, we
1063           need to use only one message; when reading, we need two. We initialize
1064           most things with sane defaults, to keep the code below somewhat
1065           simpler. */
1066         unsigned char msgbuf0[34];
1067         unsigned char msgbuf1[34];
1068         int num = read_write == I2C_SMBUS_READ?2:1;
1069         struct i2c_msg msg[2] = { { addr, flags, 1, msgbuf0 },
1070                                   { addr, flags | I2C_M_RD, 0, msgbuf1 }
1071                                 };
1072         int i;
1073
1074         msgbuf0[0] = command;
1075         switch(size) {
1076         case I2C_SMBUS_QUICK:
1077                 msg[0].len = 0;
1078                 /* Special case: The read/write field is used as data */
1079                 msg[0].flags = flags | (read_write==I2C_SMBUS_READ)?I2C_M_RD:0;
1080                 num = 1;
1081                 break;
1082         case I2C_SMBUS_BYTE:
1083                 if (read_write == I2C_SMBUS_READ) {
1084                         /* Special case: only a read! */
1085                         msg[0].flags = I2C_M_RD | flags;
1086                         num = 1;
1087                 }
1088                 break;
1089         case I2C_SMBUS_BYTE_DATA:
1090                 if (read_write == I2C_SMBUS_READ)
1091                         msg[1].len = 1;
1092                 else {
1093                         msg[0].len = 2;
1094                         msgbuf0[1] = data->byte;
1095                 }
1096                 break;
1097         case I2C_SMBUS_WORD_DATA:
1098                 if (read_write == I2C_SMBUS_READ)
1099                         msg[1].len = 2;
1100                 else {
1101                         msg[0].len=3;
1102                         msgbuf0[1] = data->word & 0xff;
1103                         msgbuf0[2] = (data->word >> 8) & 0xff;
1104                 }
1105                 break;
1106         case I2C_SMBUS_PROC_CALL:
1107                 num = 2; /* Special case */
1108                 read_write = I2C_SMBUS_READ;
1109                 msg[0].len = 3;
1110                 msg[1].len = 2;
1111                 msgbuf0[1] = data->word & 0xff;
1112                 msgbuf0[2] = (data->word >> 8) & 0xff;
1113                 break;
1114         case I2C_SMBUS_BLOCK_DATA:
1115         case I2C_SMBUS_BLOCK_DATA_PEC:
1116                 if (read_write == I2C_SMBUS_READ) {
1117                         dev_err(&adapter->dev, "Block read not supported "
1118                                "under I2C emulation!\n");
1119                         return -1;
1120                 } else {
1121                         msg[0].len = data->block[0] + 2;
1122                         if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 2) {
1123                                 dev_err(&adapter->dev, "smbus_access called with "
1124                                        "invalid block write size (%d)\n",
1125                                        data->block[0]);
1126                                 return -1;
1127                         }
1128                         if(size == I2C_SMBUS_BLOCK_DATA_PEC)
1129                                 (msg[0].len)++;
1130                         for (i = 1; i <= msg[0].len; i++)
1131                                 msgbuf0[i] = data->block[i-1];
1132                 }
1133                 break;
1134         case I2C_SMBUS_BLOCK_PROC_CALL:
1135         case I2C_SMBUS_BLOCK_PROC_CALL_PEC:
1136                 dev_dbg(&adapter->dev, "Block process call not supported "
1137                        "under I2C emulation!\n");
1138                 return -1;
1139         case I2C_SMBUS_I2C_BLOCK_DATA:
1140                 if (read_write == I2C_SMBUS_READ) {
1141                         msg[1].len = I2C_SMBUS_I2C_BLOCK_MAX;
1142                 } else {
1143                         msg[0].len = data->block[0] + 1;
1144                         if (msg[0].len > I2C_SMBUS_I2C_BLOCK_MAX + 1) {
1145                                 dev_err(&adapter->dev, "i2c_smbus_xfer_emulated called with "
1146                                        "invalid block write size (%d)\n",
1147                                        data->block[0]);
1148                                 return -1;
1149                         }
1150                         for (i = 1; i <= data->block[0]; i++)
1151                                 msgbuf0[i] = data->block[i];
1152                 }
1153                 break;
1154         default:
1155                 dev_err(&adapter->dev, "smbus_access called with invalid size (%d)\n",
1156                        size);
1157                 return -1;
1158         }
1159
1160         if (i2c_transfer(adapter, msg, num) < 0)
1161                 return -1;
1162
1163         if (read_write == I2C_SMBUS_READ)
1164                 switch(size) {
1165                         case I2C_SMBUS_BYTE:
1166                                 data->byte = msgbuf0[0];
1167                                 break;
1168                         case I2C_SMBUS_BYTE_DATA:
1169                                 data->byte = msgbuf1[0];
1170                                 break;
1171                         case I2C_SMBUS_WORD_DATA:
1172                         case I2C_SMBUS_PROC_CALL:
1173                                 data->word = msgbuf1[0] | (msgbuf1[1] << 8);
1174                                 break;
1175                         case I2C_SMBUS_I2C_BLOCK_DATA:
1176                                 /* fixed at 32 for now */
1177                                 data->block[0] = I2C_SMBUS_I2C_BLOCK_MAX;
1178                                 for (i = 0; i < I2C_SMBUS_I2C_BLOCK_MAX; i++)
1179                                         data->block[i+1] = msgbuf1[i];
1180                                 break;
1181                 }
1182         return 0;
1183 }
1184
1185
1186 s32 i2c_smbus_xfer(struct i2c_adapter * adapter, u16 addr, unsigned short flags,
1187                    char read_write, u8 command, int size,
1188                    union i2c_smbus_data * data)
1189 {
1190         s32 res;
1191         int swpec = 0;
1192         u8 partial = 0;
1193
1194         flags &= I2C_M_TEN | I2C_CLIENT_PEC;
1195         if((flags & I2C_CLIENT_PEC) &&
1196            !(i2c_check_functionality(adapter, I2C_FUNC_SMBUS_HWPEC_CALC))) {
1197                 swpec = 1;
1198                 if(read_write == I2C_SMBUS_READ &&
1199                    size == I2C_SMBUS_BLOCK_DATA)
1200                         size = I2C_SMBUS_BLOCK_DATA_PEC;
1201                 else if(size == I2C_SMBUS_PROC_CALL)
1202                         size = I2C_SMBUS_PROC_CALL_PEC;
1203                 else if(size == I2C_SMBUS_BLOCK_PROC_CALL) {
1204                         i2c_smbus_add_pec(addr, command,
1205                                           I2C_SMBUS_BLOCK_DATA, data);
1206                         partial = data->block[data->block[0] + 1];
1207                         size = I2C_SMBUS_BLOCK_PROC_CALL_PEC;
1208                 } else if(read_write == I2C_SMBUS_WRITE &&
1209                           size != I2C_SMBUS_QUICK &&
1210                           size != I2C_SMBUS_I2C_BLOCK_DATA)
1211                         size = i2c_smbus_add_pec(addr, command, size, data);
1212         }
1213
1214         if (adapter->algo->smbus_xfer) {
1215                 down(&adapter->bus_lock);
1216                 res = adapter->algo->smbus_xfer(adapter,addr,flags,read_write,
1217                                                 command,size,data);
1218                 up(&adapter->bus_lock);
1219         } else
1220                 res = i2c_smbus_xfer_emulated(adapter,addr,flags,read_write,
1221                                               command,size,data);
1222
1223         if(res >= 0 && swpec &&
1224            size != I2C_SMBUS_QUICK && size != I2C_SMBUS_I2C_BLOCK_DATA &&
1225            (read_write == I2C_SMBUS_READ || size == I2C_SMBUS_PROC_CALL_PEC ||
1226             size == I2C_SMBUS_BLOCK_PROC_CALL_PEC)) {
1227                 if(i2c_smbus_check_pec(addr, command, size, partial, data))
1228                         return -1;
1229         }
1230         return res;
1231 }
1232
1233
1234 /* You should always define `functionality'; the 'else' is just for
1235    backward compatibility. */
1236 u32 i2c_get_functionality (struct i2c_adapter *adap)
1237 {
1238         if (adap->algo->functionality)
1239                 return adap->algo->functionality(adap);
1240         else
1241                 return 0xffffffff;
1242 }
1243
1244 int i2c_check_functionality (struct i2c_adapter *adap, u32 func)
1245 {
1246         u32 adap_func = i2c_get_functionality (adap);
1247         return (func & adap_func) == func;
1248 }
1249
1250 EXPORT_SYMBOL(i2c_add_adapter);
1251 EXPORT_SYMBOL(i2c_del_adapter);
1252 EXPORT_SYMBOL(i2c_add_driver);
1253 EXPORT_SYMBOL(i2c_del_driver);
1254 EXPORT_SYMBOL(i2c_attach_client);
1255 EXPORT_SYMBOL(i2c_detach_client);
1256 EXPORT_SYMBOL(i2c_use_client);
1257 EXPORT_SYMBOL(i2c_release_client);
1258 EXPORT_SYMBOL(i2c_clients_command);
1259 EXPORT_SYMBOL(i2c_check_addr);
1260
1261 EXPORT_SYMBOL(i2c_master_send);
1262 EXPORT_SYMBOL(i2c_master_recv);
1263 EXPORT_SYMBOL(i2c_control);
1264 EXPORT_SYMBOL(i2c_transfer);
1265 EXPORT_SYMBOL(i2c_adapter_id);
1266 EXPORT_SYMBOL(i2c_get_adapter);
1267 EXPORT_SYMBOL(i2c_put_adapter);
1268 EXPORT_SYMBOL(i2c_probe);
1269
1270 EXPORT_SYMBOL(i2c_smbus_xfer);
1271 EXPORT_SYMBOL(i2c_smbus_write_quick);
1272 EXPORT_SYMBOL(i2c_smbus_read_byte);
1273 EXPORT_SYMBOL(i2c_smbus_write_byte);
1274 EXPORT_SYMBOL(i2c_smbus_read_byte_data);
1275 EXPORT_SYMBOL(i2c_smbus_write_byte_data);
1276 EXPORT_SYMBOL(i2c_smbus_read_word_data);
1277 EXPORT_SYMBOL(i2c_smbus_write_word_data);
1278 EXPORT_SYMBOL(i2c_smbus_write_block_data);
1279 EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data);
1280
1281 EXPORT_SYMBOL(i2c_get_functionality);
1282 EXPORT_SYMBOL(i2c_check_functionality);
1283
1284 MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>");
1285 MODULE_DESCRIPTION("I2C-Bus main module");
1286 MODULE_LICENSE("GPL");