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