err.no Git - linux-2.6/blob - 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 /* match always succeeds, as we want the probe() to tell if we really accept this match */
  42 static int i2c_device_match(struct device *dev, struct device_driver *drv)
  43 {
  44         return 1;
  45 }
  46
  47 static int i2c_bus_suspend(struct device * dev, pm_message_t state)
  48 {
  49         int rc = 0;
  50
  51         if (dev->driver && dev->driver->suspend)
  52                 rc = dev->driver->suspend(dev,state,0);
  53         return rc;
  54 }
  55
  56 static int i2c_bus_resume(struct device * dev)
  57 {
  58         int rc = 0;
  59
  60         if (dev->driver && dev->driver->resume)
  61                 rc = dev->driver->resume(dev,0);
  62         return rc;
  63 }
  64
  65 static struct bus_type i2c_bus_type = {
  66         .name =         "i2c",
  67         .match =        i2c_device_match,
  68         .suspend =      i2c_bus_suspend,
  69         .resume =       i2c_bus_resume,
  70 };
  71
  72 static int i2c_device_probe(struct device *dev)
  73 {
  74         return -ENODEV;
  75 }
  76
  77 static int i2c_device_remove(struct device *dev)
  78 {
  79         return 0;
  80 }
  81
  82 static void i2c_adapter_dev_release(struct device *dev)
  83 {
  84         struct i2c_adapter *adap = dev_to_i2c_adapter(dev);
  85         complete(&adap->dev_released);
  86 }
  87
  88 static struct device_driver i2c_adapter_driver = {
  89         .name = "i2c_adapter",
  90         .bus = &i2c_bus_type,
  91         .probe = i2c_device_probe,
  92         .remove = i2c_device_remove,
  93 };
  94
  95 static void i2c_adapter_class_dev_release(struct class_device *dev)
  96 {
  97         struct i2c_adapter *adap = class_dev_to_i2c_adapter(dev);
  98         complete(&adap->class_dev_released);
  99 }
 100
 101 static struct class i2c_adapter_class = {
 102         .name =         "i2c-adapter",
 103         .release =      &i2c_adapter_class_dev_release,
 104 };
 105
 106 static ssize_t show_adapter_name(struct device *dev, struct device_attribute *attr, char *buf)
 107 {
 108         struct i2c_adapter *adap = dev_to_i2c_adapter(dev);
 109         return sprintf(buf, "%s\n", adap->name);
 110 }
 111 static DEVICE_ATTR(name, S_IRUGO, show_adapter_name, NULL);
 112
 113
 114 static void i2c_client_release(struct device *dev)
 115 {
 116         struct i2c_client *client = to_i2c_client(dev);
 117         complete(&client->released);
 118 }
 119
 120 static ssize_t show_client_name(struct device *dev, struct device_attribute *attr, char *buf)
 121 {
 122         struct i2c_client *client = to_i2c_client(dev);
 123         return sprintf(buf, "%s\n", client->name);
 124 }
 125
 126 /*
 127  * We can't use the DEVICE_ATTR() macro here as we want the same filename for a
 128  * different type of a device.  So beware if the DEVICE_ATTR() macro ever
 129  * changes, this definition will also have to change.
 130  */
 131 static struct device_attribute dev_attr_client_name = {
 132         .attr   = {.name = "name", .mode = S_IRUGO, .owner = THIS_MODULE },
 133         .show   = &show_client_name,
 134 };
 135
 136
 137 /* ---------------------------------------------------
 138  * registering functions
 139  * ---------------------------------------------------
 140  */
 141
 142 /* -----
 143  * i2c_add_adapter is called from within the algorithm layer,
 144  * when a new hw adapter registers. A new device is register to be
 145  * available for clients.
 146  */
 147 int i2c_add_adapter(struct i2c_adapter *adap)
 148 {
 149         int id, res = 0;
 150         struct list_head   *item;
 151         struct i2c_driver  *driver;
 152
 153         down(&core_lists);
 154
 155         if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0) {
 156                 res = -ENOMEM;
 157                 goto out_unlock;
 158         }
 159
 160         res = idr_get_new(&i2c_adapter_idr, NULL, &id);
 161         if (res < 0) {
 162                 if (res == -EAGAIN)
 163                         res = -ENOMEM;
 164                 goto out_unlock;
 165         }
 166
 167         adap->nr =  id & MAX_ID_MASK;
 168         init_MUTEX(&adap->bus_lock);
 169         init_MUTEX(&adap->clist_lock);
 170         list_add_tail(&adap->list,&adapters);
 171         INIT_LIST_HEAD(&adap->clients);
 172
 173         /* Add the adapter to the driver core.
 174          * If the parent pointer is not set up,
 175          * we add this adapter to the host bus.
 176          */
 177         if (adap->dev.parent == NULL)
 178                 adap->dev.parent = &platform_bus;
 179         sprintf(adap->dev.bus_id, "i2c-%d", adap->nr);
 180         adap->dev.driver = &i2c_adapter_driver;
 181         adap->dev.release = &i2c_adapter_dev_release;
 182         device_register(&adap->dev);
 183         device_create_file(&adap->dev, &dev_attr_name);
 184
 185         /* Add this adapter to the i2c_adapter class */
 186         memset(&adap->class_dev, 0x00, sizeof(struct class_device));
 187         adap->class_dev.dev = &adap->dev;
 188         adap->class_dev.class = &i2c_adapter_class;
 189         strlcpy(adap->class_dev.class_id, adap->dev.bus_id, BUS_ID_SIZE);
 190         class_device_register(&adap->class_dev);
 191
 192         /* inform drivers of new adapters */
 193         list_for_each(item,&drivers) {
 194                 driver = list_entry(item, struct i2c_driver, list);
 195                 if (driver->flags & I2C_DF_NOTIFY)
 196                         /* We ignore the return code; if it fails, too bad */
 197                         driver->attach_adapter(adap);
 198         }
 199
 200         dev_dbg(&adap->dev, "registered as adapter #%d\n", adap->nr);
 201
 202 out_unlock:
 203         up(&core_lists);
 204         return res;
 205 }
 206
 207
 208 int i2c_del_adapter(struct i2c_adapter *adap)
 209 {
 210         struct list_head  *item, *_n;
 211         struct i2c_adapter *adap_from_list;
 212         struct i2c_driver *driver;
 213         struct i2c_client *client;
 214         int res = 0;
 215
 216         down(&core_lists);
 217
 218         /* First make sure that this adapter was ever added */
 219         list_for_each_entry(adap_from_list, &adapters, list) {
 220                 if (adap_from_list == adap)
 221                         break;
 222         }
 223         if (adap_from_list != adap) {
 224                 pr_debug("I2C: Attempting to delete an unregistered "
 225                          "adapter\n");
 226                 res = -EINVAL;
 227                 goto out_unlock;
 228         }
 229
 230         list_for_each(item,&drivers) {
 231                 driver = list_entry(item, struct i2c_driver, list);
 232                 if (driver->detach_adapter)
 233                         if ((res = driver->detach_adapter(adap))) {
 234                                 dev_warn(&adap->dev, "can't detach adapter "
 235                                          "while detaching driver %s: driver not "
 236                                          "detached!", driver->name);
 237                                 goto out_unlock;
 238                         }
 239         }
 240
 241         /* detach any active clients. This must be done first, because
 242          * it can fail; in which case we give upp. */
 243         list_for_each_safe(item, _n, &adap->clients) {
 244                 client = list_entry(item, struct i2c_client, list);
 245
 246                 /* detaching devices is unconditional of the set notify
 247                  * flag, as _all_ clients that reside on the adapter
 248                  * must be deleted, as this would cause invalid states.
 249                  */
 250                 if ((res=client->driver->detach_client(client))) {
 251                         dev_err(&adap->dev, "adapter not "
 252                                 "unregistered, because client at "
 253                                 "address %02x can't be detached. ",
 254                                 client->addr);
 255                         goto out_unlock;
 256                 }
 257         }
 258
 259         /* clean up the sysfs representation */
 260         init_completion(&adap->dev_released);
 261         init_completion(&adap->class_dev_released);
 262         class_device_unregister(&adap->class_dev);
 263         device_remove_file(&adap->dev, &dev_attr_name);
 264         device_unregister(&adap->dev);
 265         list_del(&adap->list);
 266
 267         /* wait for sysfs to drop all references */
 268         wait_for_completion(&adap->dev_released);
 269         wait_for_completion(&adap->class_dev_released);
 270
 271         /* free dynamically allocated bus id */
 272         idr_remove(&i2c_adapter_idr, adap->nr);
 273
 274         dev_dbg(&adap->dev, "adapter unregistered\n");
 275
 276  out_unlock:
 277         up(&core_lists);
 278         return res;
 279 }
 280
 281
 282 /* -----
 283  * What follows is the "upwards" interface: commands for talking to clients,
 284  * which implement the functions to access the physical information of the
 285  * chips.
 286  */
 287
 288 int i2c_add_driver(struct i2c_driver *driver)
 289 {
 290         struct list_head   *item;
 291         struct i2c_adapter *adapter;
 292         int res = 0;
 293
 294         down(&core_lists);
 295
 296         /* add the driver to the list of i2c drivers in the driver core */
 297         driver->driver.name = driver->name;
 298         driver->driver.bus = &i2c_bus_type;
 299         driver->driver.probe = i2c_device_probe;
 300         driver->driver.remove = i2c_device_remove;
 301
 302         res = driver_register(&driver->driver);
 303         if (res)
 304                 goto out_unlock;
 305
 306         list_add_tail(&driver->list,&drivers);
 307         pr_debug("i2c-core: driver %s registered.\n", driver->name);
 308
 309         /* now look for instances of driver on our adapters */
 310         if (driver->flags & I2C_DF_NOTIFY) {
 311                 list_for_each(item,&adapters) {
 312                         adapter = list_entry(item, struct i2c_adapter, list);
 313                         driver->attach_adapter(adapter);
 314                 }
 315         }
 316
 317  out_unlock:
 318         up(&core_lists);
 319         return res;
 320 }
 321
 322 int i2c_del_driver(struct i2c_driver *driver)
 323 {
 324         struct list_head   *item1, *item2, *_n;
 325         struct i2c_client  *client;
 326         struct i2c_adapter *adap;
 327
 328         int res = 0;
 329
 330         down(&core_lists);
 331
 332         /* Have a look at each adapter, if clients of this driver are still
 333          * attached. If so, detach them to be able to kill the driver
 334          * afterwards.
 335          */
 336         pr_debug("i2c-core: unregister_driver - looking for clients.\n");
 337         /* removing clients does not depend on the notify flag, else
 338          * invalid operation might (will!) result, when using stale client
 339          * pointers.
 340          */
 341         list_for_each(item1,&adapters) {
 342                 adap = list_entry(item1, struct i2c_adapter, list);
 343                 dev_dbg(&adap->dev, "examining adapter\n");
 344                 if (driver->detach_adapter) {
 345                         if ((res = driver->detach_adapter(adap))) {
 346                                 dev_warn(&adap->dev, "while unregistering "
 347                                        "dummy driver %s, adapter could "
 348                                        "not be detached properly; driver "
 349                                        "not unloaded!",driver->name);
 350                                 goto out_unlock;
 351                         }
 352                 } else {
 353                         list_for_each_safe(item2, _n, &adap->clients) {
 354                                 client = list_entry(item2, struct i2c_client, list);
 355                                 if (client->driver != driver)
 356                                         continue;
 357                                 pr_debug("i2c-core.o: detaching client %s:\n", client->name);
 358                                 if ((res = driver->detach_client(client))) {
 359                                         dev_err(&adap->dev, "while "
 360                                                 "unregistering driver "
 361                                                 "`%s', the client at "
 362                                                 "address %02x of "
 363                                                 "adapter could not "
 364                                                 "be detached; driver "
 365                                                 "not unloaded!",
 366                                                 driver->name,
 367                                                 client->addr);
 368                                         goto out_unlock;
 369                                 }
 370                         }
 371                 }
 372         }
 373
 374         driver_unregister(&driver->driver);
 375         list_del(&driver->list);
 376         pr_debug("i2c-core: driver unregistered: %s\n", driver->name);
 377
 378  out_unlock:
 379         up(&core_lists);
 380         return 0;
 381 }
 382
 383 static int __i2c_check_addr(struct i2c_adapter *adapter, unsigned int addr)
 384 {
 385         struct list_head   *item;
 386         struct i2c_client  *client;
 387
 388         list_for_each(item,&adapter->clients) {
 389                 client = list_entry(item, struct i2c_client, list);
 390                 if (client->addr == addr)
 391                         return -EBUSY;
 392         }
 393         return 0;
 394 }
 395
 396 int i2c_check_addr(struct i2c_adapter *adapter, int addr)
 397 {
 398         int rval;
 399
 400         down(&adapter->clist_lock);
 401         rval = __i2c_check_addr(adapter, addr);
 402         up(&adapter->clist_lock);
 403
 404         return rval;
 405 }
 406
 407 int i2c_attach_client(struct i2c_client *client)
 408 {
 409         struct i2c_adapter *adapter = client->adapter;
 410
 411         down(&adapter->clist_lock);
 412         if (__i2c_check_addr(client->adapter, client->addr)) {
 413                 up(&adapter->clist_lock);
 414                 return -EBUSY;
 415         }
 416         list_add_tail(&client->list,&adapter->clients);
 417         up(&adapter->clist_lock);
 418
 419         if (adapter->client_register)  {
 420                 if (adapter->client_register(client))  {
 421                         dev_warn(&adapter->dev, "warning: client_register "
 422                                 "seems to have failed for client %02x\n",
 423                                 client->addr);
 424                 }
 425         }
 426
 427         dev_dbg(&adapter->dev, "client [%s] registered to adapter\n",
 428                 client->name);
 429
 430         if (client->flags & I2C_CLIENT_ALLOW_USE)
 431                 client->usage_count = 0;
 432
 433         client->dev.parent = &client->adapter->dev;
 434         client->dev.driver = &client->driver->driver;
 435         client->dev.bus = &i2c_bus_type;
 436         client->dev.release = &i2c_client_release;
 437
 438         snprintf(&client->dev.bus_id[0], sizeof(client->dev.bus_id),
 439                 "%d-%04x", i2c_adapter_id(adapter), client->addr);
 440         pr_debug("registering %s\n", client->dev.bus_id);
 441         device_register(&client->dev);
 442         device_create_file(&client->dev, &dev_attr_client_name);
 443
 444         return 0;
 445 }
 446
 447
 448 int i2c_detach_client(struct i2c_client *client)
 449 {
 450         struct i2c_adapter *adapter = client->adapter;
 451         int res = 0;
 452
 453         if ((client->flags & I2C_CLIENT_ALLOW_USE) && (client->usage_count > 0))
 454                 return -EBUSY;
 455
 456         if (adapter->client_unregister)  {
 457                 res = adapter->client_unregister(client);
 458                 if (res) {
 459                         dev_err(&client->dev,
 460                                "client_unregister [%s] failed, "
 461                                "client not detached", client->name);
 462                         goto out;
 463                 }
 464         }
 465
 466         down(&adapter->clist_lock);
 467         list_del(&client->list);
 468         init_completion(&client->released);
 469         device_remove_file(&client->dev, &dev_attr_client_name);
 470         device_unregister(&client->dev);
 471         up(&adapter->clist_lock);
 472         wait_for_completion(&client->released);
 473
 474  out:
 475         return res;
 476 }
 477
 478 static int i2c_inc_use_client(struct i2c_client *client)
 479 {
 480
 481         if (!try_module_get(client->driver->owner))
 482                 return -ENODEV;
 483         if (!try_module_get(client->adapter->owner)) {
 484                 module_put(client->driver->owner);
 485                 return -ENODEV;
 486         }
 487
 488         return 0;
 489 }
 490
 491 static void i2c_dec_use_client(struct i2c_client *client)
 492 {
 493         module_put(client->driver->owner);
 494         module_put(client->adapter->owner);
 495 }
 496
 497 int i2c_use_client(struct i2c_client *client)
 498 {
 499         int ret;
 500
 501         ret = i2c_inc_use_client(client);
 502         if (ret)
 503                 return ret;
 504
 505         if (client->flags & I2C_CLIENT_ALLOW_USE) {
 506                 if (client->flags & I2C_CLIENT_ALLOW_MULTIPLE_USE)
 507                         client->usage_count++;
 508                 else if (client->usage_count > 0)
 509                         goto busy;
 510                 else
 511                         client->usage_count++;
 512         }
 513
 514         return 0;
 515  busy:
 516         i2c_dec_use_client(client);
 517         return -EBUSY;
 518 }
 519
 520 int i2c_release_client(struct i2c_client *client)
 521 {
 522         if(client->flags & I2C_CLIENT_ALLOW_USE) {
 523                 if(client->usage_count>0)
 524                         client->usage_count--;
 525                 else {
 526                         pr_debug("i2c-core: %s used one too many times\n",
 527                                 __FUNCTION__);
 528                         return -EPERM;
 529                 }
 530         }
 531
 532         i2c_dec_use_client(client);
 533
 534         return 0;
 535 }
 536
 537 void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg)
 538 {
 539         struct list_head  *item;
 540         struct i2c_client *client;
 541
 542         down(&adap->clist_lock);
 543         list_for_each(item,&adap->clients) {
 544                 client = list_entry(item, struct i2c_client, list);
 545                 if (!try_module_get(client->driver->owner))
 546                         continue;
 547                 if (NULL != client->driver->command) {
 548                         up(&adap->clist_lock);
 549                         client->driver->command(client,cmd,arg);
 550                         down(&adap->clist_lock);
 551                 }
 552                 module_put(client->driver->owner);
 553        }
 554        up(&adap->clist_lock);
 555 }
 556
 557 static int __init i2c_init(void)
 558 {
 559         int retval;
 560
 561         retval = bus_register(&i2c_bus_type);
 562         if (retval)
 563                 return retval;
 564         retval = driver_register(&i2c_adapter_driver);
 565         if (retval)
 566                 return retval;
 567         return class_register(&i2c_adapter_class);
 568 }
 569
 570 static void __exit i2c_exit(void)
 571 {
 572         class_unregister(&i2c_adapter_class);
 573         driver_unregister(&i2c_adapter_driver);
 574         bus_unregister(&i2c_bus_type);
 575 }
 576
 577 subsys_initcall(i2c_init);
 578 module_exit(i2c_exit);
 579
 580 /* ----------------------------------------------------
 581  * the functional interface to the i2c busses.
 582  * ----------------------------------------------------
 583  */
 584
 585 int i2c_transfer(struct i2c_adapter * adap, struct i2c_msg *msgs, int num)
 586 {
 587         int ret;
 588
 589         if (adap->algo->master_xfer) {
 590 #ifdef DEBUG
 591                 for (ret = 0; ret < num; ret++) {
 592                         dev_dbg(&adap->dev, "master_xfer[%d] %c, addr=0x%02x, "
 593                                 "len=%d\n", ret, msgs[ret].flags & I2C_M_RD ?
 594                                 'R' : 'W', msgs[ret].addr, msgs[ret].len);
 595                 }
 596 #endif
 597
 598                 down(&adap->bus_lock);
 599                 ret = adap->algo->master_xfer(adap,msgs,num);
 600                 up(&adap->bus_lock);
 601
 602                 return ret;
 603         } else {
 604                 dev_dbg(&adap->dev, "I2C level transfers not supported\n");
 605                 return -ENOSYS;
 606         }
 607 }
 608
 609 int i2c_master_send(struct i2c_client *client,const char *buf ,int count)
 610 {
 611         int ret;
 612         struct i2c_adapter *adap=client->adapter;
 613         struct i2c_msg msg;
 614
 615         if (client->adapter->algo->master_xfer) {
 616                 msg.addr   = client->addr;
 617                 msg.flags = client->flags & I2C_M_TEN;
 618                 msg.len = count;
 619                 msg.buf = (char *)buf;
 620
 621                 dev_dbg(&client->adapter->dev, "master_send: writing %d bytes.\n",
 622                         count);
 623
 624                 down(&adap->bus_lock);
 625                 ret = adap->algo->master_xfer(adap,&msg,1);
 626                 up(&adap->bus_lock);
 627
 628                 /* if everything went ok (i.e. 1 msg transmitted), return #bytes
 629                  * transmitted, else error code.
 630                  */
 631                 return (ret == 1 )? count : ret;
 632         } else {
 633                 dev_err(&client->adapter->dev, "I2C level transfers not supported\n");
 634                 return -ENOSYS;
 635         }
 636 }
 637
 638 int i2c_master_recv(struct i2c_client *client, char *buf ,int count)
 639 {
 640         struct i2c_adapter *adap=client->adapter;
 641         struct i2c_msg msg;
 642         int ret;
 643         if (client->adapter->algo->master_xfer) {
 644                 msg.addr   = client->addr;
 645                 msg.flags = client->flags & I2C_M_TEN;
 646                 msg.flags |= I2C_M_RD;
 647                 msg.len = count;
 648                 msg.buf = buf;
 649
 650                 dev_dbg(&client->adapter->dev, "master_recv: reading %d bytes.\n",
 651                         count);
 652
 653                 down(&adap->bus_lock);
 654                 ret = adap->algo->master_xfer(adap,&msg,1);
 655                 up(&adap->bus_lock);
 656
 657                 dev_dbg(&client->adapter->dev, "master_recv: return:%d (count:%d, addr:0x%02x)\n",
 658                         ret, count, client->addr);
 659
 660                 /* if everything went ok (i.e. 1 msg transmitted), return #bytes
 661                 * transmitted, else error code.
 662                 */
 663                 return (ret == 1 )? count : ret;
 664         } else {
 665                 dev_err(&client->adapter->dev, "I2C level transfers not supported\n");
 666                 return -ENOSYS;
 667         }
 668 }
 669
 670
 671 int i2c_control(struct i2c_client *client,
 672         unsigned int cmd, unsigned long arg)
 673 {
 674         int ret = 0;
 675         struct i2c_adapter *adap = client->adapter;
 676
 677         dev_dbg(&client->adapter->dev, "i2c ioctl, cmd: 0x%x, arg: %#lx\n", cmd, arg);
 678         switch (cmd) {
 679                 case I2C_RETRIES:
 680                         adap->retries = arg;
 681                         break;
 682                 case I2C_TIMEOUT:
 683                         adap->timeout = arg;
 684                         break;
 685                 default:
 686                         if (adap->algo->algo_control!=NULL)
 687                                 ret = adap->algo->algo_control(adap,cmd,arg);
 688         }
 689         return ret;
 690 }
 691
 692 /* ----------------------------------------------------
 693  * the i2c address scanning function
 694  * Will not work for 10-bit addresses!
 695  * ----------------------------------------------------
 696  */
 697 int i2c_probe(struct i2c_adapter *adapter,
 698               struct i2c_client_address_data *address_data,
 699               int (*found_proc) (struct i2c_adapter *, int, int))
 700 {
 701         int addr,i,found,err;
 702         int adap_id = i2c_adapter_id(adapter);
 703
 704         /* Forget it if we can't probe using SMBUS_QUICK */
 705         if (! i2c_check_functionality(adapter,I2C_FUNC_SMBUS_QUICK))
 706                 return -1;
 707
 708         for (addr = 0x00; addr <= 0x7f; addr++) {
 709
 710                 /* Skip if already in use */
 711                 if (i2c_check_addr(adapter,addr))
 712                         continue;
 713
 714                 /* If it is in one of the force entries, we don't do any detection
 715                    at all */
 716                 found = 0;
 717
 718                 for (i = 0; !found && (address_data->force[i] != I2C_CLIENT_END); i += 2) {
 719                         if (((adap_id == address_data->force[i]) ||
 720                              (address_data->force[i] == ANY_I2C_BUS)) &&
 721                              (addr == address_data->force[i+1])) {
 722                                 dev_dbg(&adapter->dev, "found force parameter for adapter %d, addr %04x\n",
 723                                         adap_id, addr);
 724                                 if ((err = found_proc(adapter,addr,0)))
 725                                         return err;
 726                                 found = 1;
 727                         }
 728                 }
 729                 if (found)
 730                         continue;
 731
 732                 /* If this address is in one of the ignores, we can forget about
 733                    it right now */
 734                 for (i = 0;
 735                      !found && (address_data->ignore[i] != I2C_CLIENT_END);
 736                      i += 2) {
 737                         if (((adap_id == address_data->ignore[i]) ||
 738                             ((address_data->ignore[i] == ANY_I2C_BUS))) &&
 739                             (addr == address_data->ignore[i+1])) {
 740                                 dev_dbg(&adapter->dev, "found ignore parameter for adapter %d, "
 741                                         "addr %04x\n", adap_id ,addr);
 742                                 found = 1;
 743                         }
 744                 }
 745                 if (found)
 746                         continue;
 747
 748                 /* Now, we will do a detection, but only if it is in the normal or
 749                    probe entries */
 750                 for (i = 0;
 751                      !found && (address_data->normal_i2c[i] != I2C_CLIENT_END);
 752                      i += 1) {
 753                         if (addr == address_data->normal_i2c[i]) {
 754                                 found = 1;
 755                                 dev_dbg(&adapter->dev, "found normal i2c entry for adapter %d, "
 756                                         "addr %02x\n", adap_id, addr);
 757                         }
 758                 }
 759
 760                 for (i = 0;
 761                      !found && (address_data->probe[i] != I2C_CLIENT_END);
 762                      i += 2) {
 763                         if (((adap_id == address_data->probe[i]) ||
 764                             ((address_data->probe[i] == ANY_I2C_BUS))) &&
 765                             (addr == address_data->probe[i+1])) {
 766                                 found = 1;
 767                                 dev_dbg(&adapter->dev, "found probe parameter for adapter %d, "
 768                                         "addr %04x\n", adap_id,addr);
 769                         }
 770                 }
 771                 if (!found)
 772                         continue;
 773
 774                 /* OK, so we really should examine this address. First check
 775                    whether there is some client here at all! */
 776                 if (i2c_smbus_xfer(adapter,addr,0,0,0,I2C_SMBUS_QUICK,NULL) >= 0)
 777                         if ((err = found_proc(adapter,addr,-1)))
 778                                 return err;
 779         }
 780         return 0;
 781 }
 782
 783 /*
 784  * return id number for a specific adapter
 785  */
 786 int i2c_adapter_id(struct i2c_adapter *adap)
 787 {
 788         return adap->nr;
 789 }
 790
 791 struct i2c_adapter* i2c_get_adapter(int id)
 792 {
 793         struct list_head   *item;
 794         struct i2c_adapter *adapter;
 795
 796         down(&core_lists);
 797         list_for_each(item,&adapters) {
 798                 adapter = list_entry(item, struct i2c_adapter, list);
 799                 if (id == adapter->nr &&
 800                     try_module_get(adapter->owner)) {
 801                         up(&core_lists);
 802                         return adapter;
 803                 }
 804         }
 805         up(&core_lists);
 806         return NULL;
 807 }
 808
 809 void i2c_put_adapter(struct i2c_adapter *adap)
 810 {
 811         module_put(adap->owner);
 812 }
 813
 814 /* The SMBus parts */
 815
 816 #define POLY    (0x1070U << 3)
 817 static u8
 818 crc8(u16 data)
 819 {
 820         int i;
 821
 822         for(i = 0; i < 8; i++) {
 823                 if (data & 0x8000)
 824                         data = data ^ POLY;
 825                 data = data << 1;
 826         }
 827         return (u8)(data >> 8);
 828 }
 829
 830 /* CRC over count bytes in the first array plus the bytes in the rest
 831    array if it is non-null. rest[0] is the (length of rest) - 1
 832    and is included. */
 833 static u8 i2c_smbus_partial_pec(u8 crc, int count, u8 *first, u8 *rest)
 834 {
 835         int i;
 836
 837         for(i = 0; i < count; i++)
 838                 crc = crc8((crc ^ first[i]) << 8);
 839         if(rest != NULL)
 840                 for(i = 0; i <= rest[0]; i++)
 841                         crc = crc8((crc ^ rest[i]) << 8);
 842         return crc;
 843 }
 844
 845 static u8 i2c_smbus_pec(int count, u8 *first, u8 *rest)
 846 {
 847         return i2c_smbus_partial_pec(0, count, first, rest);
 848 }
 849
 850 /* Returns new "size" (transaction type)
 851    Note that we convert byte to byte_data and byte_data to word_data
 852    rather than invent new xxx_PEC transactions. */
 853 static int i2c_smbus_add_pec(u16 addr, u8 command, int size,
 854                              union i2c_smbus_data *data)
 855 {
 856         u8 buf[3];
 857
 858         buf[0] = addr << 1;
 859         buf[1] = command;
 860         switch(size) {
 861                 case I2C_SMBUS_BYTE:
 862                         data->byte = i2c_smbus_pec(2, buf, NULL);
 863                         size = I2C_SMBUS_BYTE_DATA;
 864                         break;
 865                 case I2C_SMBUS_BYTE_DATA:
 866                         buf[2] = data->byte;
 867                         data->word = buf[2] ||
 868                                     (i2c_smbus_pec(3, buf, NULL) << 8);
 869                         size = I2C_SMBUS_WORD_DATA;
 870                         break;
 871                 case I2C_SMBUS_WORD_DATA:
 872                         /* unsupported */
 873                         break;
 874                 case I2C_SMBUS_BLOCK_DATA:
 875                         data->block[data->block[0] + 1] =
 876                                      i2c_smbus_pec(2, buf, data->block);
 877                         size = I2C_SMBUS_BLOCK_DATA_PEC;
 878                         break;
 879         }
 880         return size;
 881 }
 882
 883 static int i2c_smbus_check_pec(u16 addr, u8 command, int size, u8 partial,
 884                                union i2c_smbus_data *data)
 885 {
 886         u8 buf[3], rpec, cpec;
 887
 888         buf[1] = command;
 889         switch(size) {
 890                 case I2C_SMBUS_BYTE_DATA:
 891                         buf[0] = (addr << 1) | 1;
 892                         cpec = i2c_smbus_pec(2, buf, NULL);
 893                         rpec = data->byte;
 894                         break;
 895                 case I2C_SMBUS_WORD_DATA:
 896                         buf[0] = (addr << 1) | 1;
 897                         buf[2] = data->word & 0xff;
 898                         cpec = i2c_smbus_pec(3, buf, NULL);
 899                         rpec = data->word >> 8;
 900                         break;
 901                 case I2C_SMBUS_WORD_DATA_PEC:
 902                         /* unsupported */
 903                         cpec = rpec = 0;
 904                         break;
 905                 case I2C_SMBUS_PROC_CALL_PEC:
 906                         /* unsupported */
 907                         cpec = rpec = 0;
 908                         break;
 909                 case I2C_SMBUS_BLOCK_DATA_PEC:
 910                         buf[0] = (addr << 1);
 911                         buf[2] = (addr << 1) | 1;
 912                         cpec = i2c_smbus_pec(3, buf, data->block);
 913                         rpec = data->block[data->block[0] + 1];
 914                         break;
 915                 case I2C_SMBUS_BLOCK_PROC_CALL_PEC:
 916                         buf[0] = (addr << 1) | 1;
 917                         rpec = i2c_smbus_partial_pec(partial, 1,
 918                                                      buf, data->block);
 919                         cpec = data->block[data->block[0] + 1];
 920                         break;
 921                 default:
 922                         cpec = rpec = 0;
 923                         break;
 924         }
 925         if (rpec != cpec) {
 926                 pr_debug("i2c-core: Bad PEC 0x%02x vs. 0x%02x\n",
 927                         rpec, cpec);
 928                 return -1;
 929         }
 930         return 0;
 931 }
 932
 933 s32 i2c_smbus_write_quick(struct i2c_client *client, u8 value)
 934 {
 935         return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
 936                               value,0,I2C_SMBUS_QUICK,NULL);
 937 }
 938
 939 s32 i2c_smbus_read_byte(struct i2c_client *client)
 940 {
 941         union i2c_smbus_data data;
 942         if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
 943                            I2C_SMBUS_READ,0,I2C_SMBUS_BYTE, &data))
 944                 return -1;
 945         else
 946                 return 0x0FF & data.byte;
 947 }
 948
 949 s32 i2c_smbus_write_byte(struct i2c_client *client, u8 value)
 950 {
 951         union i2c_smbus_data data;      /* only for PEC */
 952         return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
 953                               I2C_SMBUS_WRITE,value, I2C_SMBUS_BYTE,&data);
 954 }
 955
 956 s32 i2c_smbus_read_byte_data(struct i2c_client *client, u8 command)
 957 {
 958         union i2c_smbus_data data;
 959         if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
 960                            I2C_SMBUS_READ,command, I2C_SMBUS_BYTE_DATA,&data))
 961                 return -1;
 962         else
 963                 return 0x0FF & data.byte;
 964 }
 965
 966 s32 i2c_smbus_write_byte_data(struct i2c_client *client, u8 command, u8 value)
 967 {
 968         union i2c_smbus_data data;
 969         data.byte = value;
 970         return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
 971                               I2C_SMBUS_WRITE,command,
 972                               I2C_SMBUS_BYTE_DATA,&data);
 973 }
 974
 975 s32 i2c_smbus_read_word_data(struct i2c_client *client, u8 command)
 976 {
 977         union i2c_smbus_data data;
 978         if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
 979                            I2C_SMBUS_READ,command, I2C_SMBUS_WORD_DATA, &data))
 980                 return -1;
 981         else
 982                 return 0x0FFFF & data.word;
 983 }
 984
 985 s32 i2c_smbus_write_word_data(struct i2c_client *client, u8 command, u16 value)
 986 {
 987         union i2c_smbus_data data;
 988         data.word = value;
 989         return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
 990                               I2C_SMBUS_WRITE,command,
 991                               I2C_SMBUS_WORD_DATA,&data);
 992 }
 993
 994 s32 i2c_smbus_write_block_data(struct i2c_client *client, u8 command,
 995                                u8 length, u8 *values)
 996 {
 997         union i2c_smbus_data data;
 998         int i;
 999         if (length > I2C_SMBUS_BLOCK_MAX)
1000                 length = I2C_SMBUS_BLOCK_MAX;
1001         for (i = 1; i <= length; i++)
1002                 data.block[i] = values[i-1];
1003         data.block[0] = length;
1004         return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
1005                               I2C_SMBUS_WRITE,command,
1006                               I2C_SMBUS_BLOCK_DATA,&data);
1007 }
1008
1009 /* Returns the number of read bytes */
1010 s32 i2c_smbus_read_i2c_block_data(struct i2c_client *client, u8 command, u8 *values)
1011 {
1012         union i2c_smbus_data data;
1013         int i;
1014         if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
1015                               I2C_SMBUS_READ,command,
1016                               I2C_SMBUS_I2C_BLOCK_DATA,&data))
1017                 return -1;
1018         else {
1019                 for (i = 1; i <= data.block[0]; i++)
1020                         values[i-1] = data.block[i];
1021                 return data.block[0];
1022         }
1023 }
1024
1025 /* Simulate a SMBus command using the i2c protocol
1026    No checking of parameters is done!  */
1027 static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr,
1028                                    unsigned short flags,
1029                                    char read_write, u8 command, int size,
1030                                    union i2c_smbus_data * data)
1031 {
1032         /* So we need to generate a series of msgs. In the case of writing, we
1033           need to use only one message; when reading, we need two. We initialize
1034           most things with sane defaults, to keep the code below somewhat
1035           simpler. */
1036         unsigned char msgbuf0[34];
1037         unsigned char msgbuf1[34];
1038         int num = read_write == I2C_SMBUS_READ?2:1;
1039         struct i2c_msg msg[2] = { { addr, flags, 1, msgbuf0 },
1040                                   { addr, flags | I2C_M_RD, 0, msgbuf1 }
1041                                 };
1042         int i;
1043
1044         msgbuf0[0] = command;
1045         switch(size) {
1046         case I2C_SMBUS_QUICK:
1047                 msg[0].len = 0;
1048                 /* Special case: The read/write field is used as data */
1049                 msg[0].flags = flags | (read_write==I2C_SMBUS_READ)?I2C_M_RD:0;
1050                 num = 1;
1051                 break;
1052         case I2C_SMBUS_BYTE:
1053                 if (read_write == I2C_SMBUS_READ) {
1054                         /* Special case: only a read! */
1055                         msg[0].flags = I2C_M_RD | flags;
1056                         num = 1;
1057                 }
1058                 break;
1059         case I2C_SMBUS_BYTE_DATA:
1060                 if (read_write == I2C_SMBUS_READ)
1061                         msg[1].len = 1;
1062                 else {
1063                         msg[0].len = 2;
1064                         msgbuf0[1] = data->byte;
1065                 }
1066                 break;
1067         case I2C_SMBUS_WORD_DATA:
1068                 if (read_write == I2C_SMBUS_READ)
1069                         msg[1].len = 2;
1070                 else {
1071                         msg[0].len=3;
1072                         msgbuf0[1] = data->word & 0xff;
1073                         msgbuf0[2] = (data->word >> 8) & 0xff;
1074                 }
1075                 break;
1076         case I2C_SMBUS_PROC_CALL:
1077                 num = 2; /* Special case */
1078                 read_write = I2C_SMBUS_READ;
1079                 msg[0].len = 3;
1080                 msg[1].len = 2;
1081                 msgbuf0[1] = data->word & 0xff;
1082                 msgbuf0[2] = (data->word >> 8) & 0xff;
1083                 break;
1084         case I2C_SMBUS_BLOCK_DATA:
1085         case I2C_SMBUS_BLOCK_DATA_PEC:
1086                 if (read_write == I2C_SMBUS_READ) {
1087                         dev_err(&adapter->dev, "Block read not supported "
1088                                "under I2C emulation!\n");
1089                         return -1;
1090                 } else {
1091                         msg[0].len = data->block[0] + 2;
1092                         if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 2) {
1093                                 dev_err(&adapter->dev, "smbus_access called with "
1094                                        "invalid block write size (%d)\n",
1095                                        data->block[0]);
1096                                 return -1;
1097                         }
1098                         if(size == I2C_SMBUS_BLOCK_DATA_PEC)
1099                                 (msg[0].len)++;
1100                         for (i = 1; i <= msg[0].len; i++)
1101                                 msgbuf0[i] = data->block[i-1];
1102                 }
1103                 break;
1104         case I2C_SMBUS_BLOCK_PROC_CALL:
1105         case I2C_SMBUS_BLOCK_PROC_CALL_PEC:
1106                 dev_dbg(&adapter->dev, "Block process call not supported "
1107                        "under I2C emulation!\n");
1108                 return -1;
1109         case I2C_SMBUS_I2C_BLOCK_DATA:
1110                 if (read_write == I2C_SMBUS_READ) {
1111                         msg[1].len = I2C_SMBUS_I2C_BLOCK_MAX;
1112                 } else {
1113                         msg[0].len = data->block[0] + 1;
1114                         if (msg[0].len > I2C_SMBUS_I2C_BLOCK_MAX + 1) {
1115                                 dev_err(&adapter->dev, "i2c_smbus_xfer_emulated called with "
1116                                        "invalid block write size (%d)\n",
1117                                        data->block[0]);
1118                                 return -1;
1119                         }
1120                         for (i = 1; i <= data->block[0]; i++)
1121                                 msgbuf0[i] = data->block[i];
1122                 }
1123                 break;
1124         default:
1125                 dev_err(&adapter->dev, "smbus_access called with invalid size (%d)\n",
1126                        size);
1127                 return -1;
1128         }
1129
1130         if (i2c_transfer(adapter, msg, num) < 0)
1131                 return -1;
1132
1133         if (read_write == I2C_SMBUS_READ)
1134                 switch(size) {
1135                         case I2C_SMBUS_BYTE:
1136                                 data->byte = msgbuf0[0];
1137                                 break;
1138                         case I2C_SMBUS_BYTE_DATA:
1139                                 data->byte = msgbuf1[0];
1140                                 break;
1141                         case I2C_SMBUS_WORD_DATA:
1142                         case I2C_SMBUS_PROC_CALL:
1143                                 data->word = msgbuf1[0] | (msgbuf1[1] << 8);
1144                                 break;
1145                         case I2C_SMBUS_I2C_BLOCK_DATA:
1146                                 /* fixed at 32 for now */
1147                                 data->block[0] = I2C_SMBUS_I2C_BLOCK_MAX;
1148                                 for (i = 0; i < I2C_SMBUS_I2C_BLOCK_MAX; i++)
1149                                         data->block[i+1] = msgbuf1[i];
1150                                 break;
1151                 }
1152         return 0;
1153 }
1154
1155
1156 s32 i2c_smbus_xfer(struct i2c_adapter * adapter, u16 addr, unsigned short flags,
1157                    char read_write, u8 command, int size,
1158                    union i2c_smbus_data * data)
1159 {
1160         s32 res;
1161         int swpec = 0;
1162         u8 partial = 0;
1163
1164         flags &= I2C_M_TEN | I2C_CLIENT_PEC;
1165         if((flags & I2C_CLIENT_PEC) &&
1166            !(i2c_check_functionality(adapter, I2C_FUNC_SMBUS_HWPEC_CALC))) {
1167                 swpec = 1;
1168                 if(read_write == I2C_SMBUS_READ &&
1169                    size == I2C_SMBUS_BLOCK_DATA)
1170                         size = I2C_SMBUS_BLOCK_DATA_PEC;
1171                 else if(size == I2C_SMBUS_PROC_CALL)
1172                         size = I2C_SMBUS_PROC_CALL_PEC;
1173                 else if(size == I2C_SMBUS_BLOCK_PROC_CALL) {
1174                         i2c_smbus_add_pec(addr, command,
1175                                           I2C_SMBUS_BLOCK_DATA, data);
1176                         partial = data->block[data->block[0] + 1];
1177                         size = I2C_SMBUS_BLOCK_PROC_CALL_PEC;
1178                 } else if(read_write == I2C_SMBUS_WRITE &&
1179                           size != I2C_SMBUS_QUICK &&
1180                           size != I2C_SMBUS_I2C_BLOCK_DATA)
1181                         size = i2c_smbus_add_pec(addr, command, size, data);
1182         }
1183
1184         if (adapter->algo->smbus_xfer) {
1185                 down(&adapter->bus_lock);
1186                 res = adapter->algo->smbus_xfer(adapter,addr,flags,read_write,
1187                                                 command,size,data);
1188                 up(&adapter->bus_lock);
1189         } else
1190                 res = i2c_smbus_xfer_emulated(adapter,addr,flags,read_write,
1191                                               command,size,data);
1192
1193         if(res >= 0 && swpec &&
1194            size != I2C_SMBUS_QUICK && size != I2C_SMBUS_I2C_BLOCK_DATA &&
1195            (read_write == I2C_SMBUS_READ || size == I2C_SMBUS_PROC_CALL_PEC ||
1196             size == I2C_SMBUS_BLOCK_PROC_CALL_PEC)) {
1197                 if(i2c_smbus_check_pec(addr, command, size, partial, data))
1198                         return -1;
1199         }
1200         return res;
1201 }
1202
1203
1204 EXPORT_SYMBOL(i2c_add_adapter);
1205 EXPORT_SYMBOL(i2c_del_adapter);
1206 EXPORT_SYMBOL(i2c_add_driver);
1207 EXPORT_SYMBOL(i2c_del_driver);
1208 EXPORT_SYMBOL(i2c_attach_client);
1209 EXPORT_SYMBOL(i2c_detach_client);
1210 EXPORT_SYMBOL(i2c_use_client);
1211 EXPORT_SYMBOL(i2c_release_client);
1212 EXPORT_SYMBOL(i2c_clients_command);
1213 EXPORT_SYMBOL(i2c_check_addr);
1214
1215 EXPORT_SYMBOL(i2c_master_send);
1216 EXPORT_SYMBOL(i2c_master_recv);
1217 EXPORT_SYMBOL(i2c_control);
1218 EXPORT_SYMBOL(i2c_transfer);
1219 EXPORT_SYMBOL(i2c_adapter_id);
1220 EXPORT_SYMBOL(i2c_get_adapter);
1221 EXPORT_SYMBOL(i2c_put_adapter);
1222 EXPORT_SYMBOL(i2c_probe);
1223
1224 EXPORT_SYMBOL(i2c_smbus_xfer);
1225 EXPORT_SYMBOL(i2c_smbus_write_quick);
1226 EXPORT_SYMBOL(i2c_smbus_read_byte);
1227 EXPORT_SYMBOL(i2c_smbus_write_byte);
1228 EXPORT_SYMBOL(i2c_smbus_read_byte_data);
1229 EXPORT_SYMBOL(i2c_smbus_write_byte_data);
1230 EXPORT_SYMBOL(i2c_smbus_read_word_data);
1231 EXPORT_SYMBOL(i2c_smbus_write_word_data);
1232 EXPORT_SYMBOL(i2c_smbus_write_block_data);
1233 EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data);
1234
1235 MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>");
1236 MODULE_DESCRIPTION("I2C-Bus main module");
1237 MODULE_LICENSE("GPL");