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   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> and
  23    Jean Delvare <khali@linux-fr.org> */
  24
  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/platform_device.h>
  33 #include <linux/mutex.h>
  34 #include <linux/completion.h>
  35 #include <linux/hardirq.h>
  36 #include <linux/irqflags.h>
  37 #include <asm/uaccess.h>
  38
  39 #include "i2c-core.h"
  40
  41
  42 static DEFINE_MUTEX(core_lock);
  43 static DEFINE_IDR(i2c_adapter_idr);
  44
  45 #define is_newstyle_driver(d) ((d)->probe || (d)->remove || (d)->detect)
  46
  47 static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver);
  48
  49 /* ------------------------------------------------------------------------- */
  50
  51 static const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id,
  52                                                 const struct i2c_client *client)
  53 {
  54         while (id->name[0]) {
  55                 if (strcmp(client->name, id->name) == 0)
  56                         return id;
  57                 id++;
  58         }
  59         return NULL;
  60 }
  61
  62 static int i2c_device_match(struct device *dev, struct device_driver *drv)
  63 {
  64         struct i2c_client       *client = to_i2c_client(dev);
  65         struct i2c_driver       *driver = to_i2c_driver(drv);
  66
  67         /* make legacy i2c drivers bypass driver model probing entirely;
  68          * such drivers scan each i2c adapter/bus themselves.
  69          */
  70         if (!is_newstyle_driver(driver))
  71                 return 0;
  72
  73         /* match on an id table if there is one */
  74         if (driver->id_table)
  75                 return i2c_match_id(driver->id_table, client) != NULL;
  76
  77         return 0;
  78 }
  79
  80 #ifdef  CONFIG_HOTPLUG
  81
  82 /* uevent helps with hotplug: modprobe -q $(MODALIAS) */
  83 static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env)
  84 {
  85         struct i2c_client       *client = to_i2c_client(dev);
  86
  87         /* by definition, legacy drivers can't hotplug */
  88         if (dev->driver)
  89                 return 0;
  90
  91         if (add_uevent_var(env, "MODALIAS=%s%s",
  92                            I2C_MODULE_PREFIX, client->name))
  93                 return -ENOMEM;
  94         dev_dbg(dev, "uevent\n");
  95         return 0;
  96 }
  97
  98 #else
  99 #define i2c_device_uevent       NULL
 100 #endif  /* CONFIG_HOTPLUG */
 101
 102 static int i2c_device_probe(struct device *dev)
 103 {
 104         struct i2c_client       *client = to_i2c_client(dev);
 105         struct i2c_driver       *driver = to_i2c_driver(dev->driver);
 106         int status;
 107
 108         if (!driver->probe || !driver->id_table)
 109                 return -ENODEV;
 110         client->driver = driver;
 111         if (!device_can_wakeup(&client->dev))
 112                 device_init_wakeup(&client->dev,
 113                                         client->flags & I2C_CLIENT_WAKE);
 114         dev_dbg(dev, "probe\n");
 115
 116         status = driver->probe(client, i2c_match_id(driver->id_table, client));
 117         if (status)
 118                 client->driver = NULL;
 119         return status;
 120 }
 121
 122 static int i2c_device_remove(struct device *dev)
 123 {
 124         struct i2c_client       *client = to_i2c_client(dev);
 125         struct i2c_driver       *driver;
 126         int                     status;
 127
 128         if (!dev->driver)
 129                 return 0;
 130
 131         driver = to_i2c_driver(dev->driver);
 132         if (driver->remove) {
 133                 dev_dbg(dev, "remove\n");
 134                 status = driver->remove(client);
 135         } else {
 136                 dev->driver = NULL;
 137                 status = 0;
 138         }
 139         if (status == 0)
 140                 client->driver = NULL;
 141         return status;
 142 }
 143
 144 static void i2c_device_shutdown(struct device *dev)
 145 {
 146         struct i2c_driver *driver;
 147
 148         if (!dev->driver)
 149                 return;
 150         driver = to_i2c_driver(dev->driver);
 151         if (driver->shutdown)
 152                 driver->shutdown(to_i2c_client(dev));
 153 }
 154
 155 static int i2c_device_suspend(struct device * dev, pm_message_t mesg)
 156 {
 157         struct i2c_driver *driver;
 158
 159         if (!dev->driver)
 160                 return 0;
 161         driver = to_i2c_driver(dev->driver);
 162         if (!driver->suspend)
 163                 return 0;
 164         return driver->suspend(to_i2c_client(dev), mesg);
 165 }
 166
 167 static int i2c_device_resume(struct device * dev)
 168 {
 169         struct i2c_driver *driver;
 170
 171         if (!dev->driver)
 172                 return 0;
 173         driver = to_i2c_driver(dev->driver);
 174         if (!driver->resume)
 175                 return 0;
 176         return driver->resume(to_i2c_client(dev));
 177 }
 178
 179 static void i2c_client_release(struct device *dev)
 180 {
 181         struct i2c_client *client = to_i2c_client(dev);
 182         complete(&client->released);
 183 }
 184
 185 static void i2c_client_dev_release(struct device *dev)
 186 {
 187         kfree(to_i2c_client(dev));
 188 }
 189
 190 static ssize_t show_client_name(struct device *dev, struct device_attribute *attr, char *buf)
 191 {
 192         struct i2c_client *client = to_i2c_client(dev);
 193         return sprintf(buf, "%s\n", client->name);
 194 }
 195
 196 static ssize_t show_modalias(struct device *dev, struct device_attribute *attr, char *buf)
 197 {
 198         struct i2c_client *client = to_i2c_client(dev);
 199         return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name);
 200 }
 201
 202 static struct device_attribute i2c_dev_attrs[] = {
 203         __ATTR(name, S_IRUGO, show_client_name, NULL),
 204         /* modalias helps coldplug:  modprobe $(cat .../modalias) */
 205         __ATTR(modalias, S_IRUGO, show_modalias, NULL),
 206         { },
 207 };
 208
 209 struct bus_type i2c_bus_type = {
 210         .name           = "i2c",
 211         .dev_attrs      = i2c_dev_attrs,
 212         .match          = i2c_device_match,
 213         .uevent         = i2c_device_uevent,
 214         .probe          = i2c_device_probe,
 215         .remove         = i2c_device_remove,
 216         .shutdown       = i2c_device_shutdown,
 217         .suspend        = i2c_device_suspend,
 218         .resume         = i2c_device_resume,
 219 };
 220 EXPORT_SYMBOL_GPL(i2c_bus_type);
 221
 222
 223 /**
 224  * i2c_verify_client - return parameter as i2c_client, or NULL
 225  * @dev: device, probably from some driver model iterator
 226  *
 227  * When traversing the driver model tree, perhaps using driver model
 228  * iterators like @device_for_each_child(), you can't assume very much
 229  * about the nodes you find.  Use this function to avoid oopses caused
 230  * by wrongly treating some non-I2C device as an i2c_client.
 231  */
 232 struct i2c_client *i2c_verify_client(struct device *dev)
 233 {
 234         return (dev->bus == &i2c_bus_type)
 235                         ? to_i2c_client(dev)
 236                         : NULL;
 237 }
 238 EXPORT_SYMBOL(i2c_verify_client);
 239
 240
 241 /**
 242  * i2c_new_device - instantiate an i2c device for use with a new style driver
 243  * @adap: the adapter managing the device
 244  * @info: describes one I2C device; bus_num is ignored
 245  * Context: can sleep
 246  *
 247  * Create a device to work with a new style i2c driver, where binding is
 248  * handled through driver model probe()/remove() methods.  This call is not
 249  * appropriate for use by mainboad initialization logic, which usually runs
 250  * during an arch_initcall() long before any i2c_adapter could exist.
 251  *
 252  * This returns the new i2c client, which may be saved for later use with
 253  * i2c_unregister_device(); or NULL to indicate an error.
 254  */
 255 struct i2c_client *
 256 i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info)
 257 {
 258         struct i2c_client       *client;
 259         int                     status;
 260
 261         client = kzalloc(sizeof *client, GFP_KERNEL);
 262         if (!client)
 263                 return NULL;
 264
 265         client->adapter = adap;
 266
 267         client->dev.platform_data = info->platform_data;
 268
 269         if (info->archdata)
 270                 client->dev.archdata = *info->archdata;
 271
 272         client->flags = info->flags;
 273         client->addr = info->addr;
 274         client->irq = info->irq;
 275
 276         strlcpy(client->name, info->type, sizeof(client->name));
 277
 278         /* a new style driver may be bound to this device when we
 279          * return from this function, or any later moment (e.g. maybe
 280          * hotplugging will load the driver module).  and the device
 281          * refcount model is the standard driver model one.
 282          */
 283         status = i2c_attach_client(client);
 284         if (status < 0) {
 285                 kfree(client);
 286                 client = NULL;
 287         }
 288         return client;
 289 }
 290 EXPORT_SYMBOL_GPL(i2c_new_device);
 291
 292
 293 /**
 294  * i2c_unregister_device - reverse effect of i2c_new_device()
 295  * @client: value returned from i2c_new_device()
 296  * Context: can sleep
 297  */
 298 void i2c_unregister_device(struct i2c_client *client)
 299 {
 300         struct i2c_adapter      *adapter = client->adapter;
 301         struct i2c_driver       *driver = client->driver;
 302
 303         if (driver && !is_newstyle_driver(driver)) {
 304                 dev_err(&client->dev, "can't unregister devices "
 305                         "with legacy drivers\n");
 306                 WARN_ON(1);
 307                 return;
 308         }
 309
 310         if (adapter->client_unregister) {
 311                 if (adapter->client_unregister(client)) {
 312                         dev_warn(&client->dev,
 313                                  "client_unregister [%s] failed\n",
 314                                  client->name);
 315                 }
 316         }
 317
 318         mutex_lock(&adapter->clist_lock);
 319         list_del(&client->list);
 320         mutex_unlock(&adapter->clist_lock);
 321
 322         device_unregister(&client->dev);
 323 }
 324 EXPORT_SYMBOL_GPL(i2c_unregister_device);
 325
 326
 327 static const struct i2c_device_id dummy_id[] = {
 328         { "dummy", 0 },
 329         { },
 330 };
 331
 332 static int dummy_probe(struct i2c_client *client,
 333                        const struct i2c_device_id *id)
 334 {
 335         return 0;
 336 }
 337
 338 static int dummy_remove(struct i2c_client *client)
 339 {
 340         return 0;
 341 }
 342
 343 static struct i2c_driver dummy_driver = {
 344         .driver.name    = "dummy",
 345         .probe          = dummy_probe,
 346         .remove         = dummy_remove,
 347         .id_table       = dummy_id,
 348 };
 349
 350 /**
 351  * i2c_new_dummy - return a new i2c device bound to a dummy driver
 352  * @adapter: the adapter managing the device
 353  * @address: seven bit address to be used
 354  * Context: can sleep
 355  *
 356  * This returns an I2C client bound to the "dummy" driver, intended for use
 357  * with devices that consume multiple addresses.  Examples of such chips
 358  * include various EEPROMS (like 24c04 and 24c08 models).
 359  *
 360  * These dummy devices have two main uses.  First, most I2C and SMBus calls
 361  * except i2c_transfer() need a client handle; the dummy will be that handle.
 362  * And second, this prevents the specified address from being bound to a
 363  * different driver.
 364  *
 365  * This returns the new i2c client, which should be saved for later use with
 366  * i2c_unregister_device(); or NULL to indicate an error.
 367  */
 368 struct i2c_client *
 369 i2c_new_dummy(struct i2c_adapter *adapter, u16 address)
 370 {
 371         struct i2c_board_info info = {
 372                 I2C_BOARD_INFO("dummy", address),
 373         };
 374
 375         return i2c_new_device(adapter, &info);
 376 }
 377 EXPORT_SYMBOL_GPL(i2c_new_dummy);
 378
 379 /* ------------------------------------------------------------------------- */
 380
 381 /* I2C bus adapters -- one roots each I2C or SMBUS segment */
 382
 383 static void i2c_adapter_dev_release(struct device *dev)
 384 {
 385         struct i2c_adapter *adap = to_i2c_adapter(dev);
 386         complete(&adap->dev_released);
 387 }
 388
 389 static ssize_t
 390 show_adapter_name(struct device *dev, struct device_attribute *attr, char *buf)
 391 {
 392         struct i2c_adapter *adap = to_i2c_adapter(dev);
 393         return sprintf(buf, "%s\n", adap->name);
 394 }
 395
 396 static struct device_attribute i2c_adapter_attrs[] = {
 397         __ATTR(name, S_IRUGO, show_adapter_name, NULL),
 398         { },
 399 };
 400
 401 static struct class i2c_adapter_class = {
 402         .owner                  = THIS_MODULE,
 403         .name                   = "i2c-adapter",
 404         .dev_attrs              = i2c_adapter_attrs,
 405 };
 406
 407 static void i2c_scan_static_board_info(struct i2c_adapter *adapter)
 408 {
 409         struct i2c_devinfo      *devinfo;
 410
 411         mutex_lock(&__i2c_board_lock);
 412         list_for_each_entry(devinfo, &__i2c_board_list, list) {
 413                 if (devinfo->busnum == adapter->nr
 414                                 && !i2c_new_device(adapter,
 415                                                 &devinfo->board_info))
 416                         printk(KERN_ERR "i2c-core: can't create i2c%d-%04x\n",
 417                                 i2c_adapter_id(adapter),
 418                                 devinfo->board_info.addr);
 419         }
 420         mutex_unlock(&__i2c_board_lock);
 421 }
 422
 423 static int i2c_do_add_adapter(struct device_driver *d, void *data)
 424 {
 425         struct i2c_driver *driver = to_i2c_driver(d);
 426         struct i2c_adapter *adap = data;
 427
 428         /* Detect supported devices on that bus, and instantiate them */
 429         i2c_detect(adap, driver);
 430
 431         /* Let legacy drivers scan this bus for matching devices */
 432         if (driver->attach_adapter) {
 433                 /* We ignore the return code; if it fails, too bad */
 434                 driver->attach_adapter(adap);
 435         }
 436         return 0;
 437 }
 438
 439 static int i2c_register_adapter(struct i2c_adapter *adap)
 440 {
 441         int res = 0, dummy;
 442
 443         /* Can't register until after driver model init */
 444         if (unlikely(WARN_ON(!i2c_bus_type.p)))
 445                 return -EAGAIN;
 446
 447         mutex_init(&adap->bus_lock);
 448         mutex_init(&adap->clist_lock);
 449         INIT_LIST_HEAD(&adap->clients);
 450
 451         mutex_lock(&core_lock);
 452
 453         /* Add the adapter to the driver core.
 454          * If the parent pointer is not set up,
 455          * we add this adapter to the host bus.
 456          */
 457         if (adap->dev.parent == NULL) {
 458                 adap->dev.parent = &platform_bus;
 459                 pr_debug("I2C adapter driver [%s] forgot to specify "
 460                          "physical device\n", adap->name);
 461         }
 462         dev_set_name(&adap->dev, "i2c-%d", adap->nr);
 463         adap->dev.release = &i2c_adapter_dev_release;
 464         adap->dev.class = &i2c_adapter_class;
 465         res = device_register(&adap->dev);
 466         if (res)
 467                 goto out_list;
 468
 469         dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name);
 470
 471         /* create pre-declared device nodes for new-style drivers */
 472         if (adap->nr < __i2c_first_dynamic_bus_num)
 473                 i2c_scan_static_board_info(adap);
 474
 475         /* Notify drivers */
 476         dummy = bus_for_each_drv(&i2c_bus_type, NULL, adap,
 477                                  i2c_do_add_adapter);
 478
 479 out_unlock:
 480         mutex_unlock(&core_lock);
 481         return res;
 482
 483 out_list:
 484         idr_remove(&i2c_adapter_idr, adap->nr);
 485         goto out_unlock;
 486 }
 487
 488 /**
 489  * i2c_add_adapter - declare i2c adapter, use dynamic bus number
 490  * @adapter: the adapter to add
 491  * Context: can sleep
 492  *
 493  * This routine is used to declare an I2C adapter when its bus number
 494  * doesn't matter.  Examples: for I2C adapters dynamically added by
 495  * USB links or PCI plugin cards.
 496  *
 497  * When this returns zero, a new bus number was allocated and stored
 498  * in adap->nr, and the specified adapter became available for clients.
 499  * Otherwise, a negative errno value is returned.
 500  */
 501 int i2c_add_adapter(struct i2c_adapter *adapter)
 502 {
 503         int     id, res = 0;
 504
 505 retry:
 506         if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0)
 507                 return -ENOMEM;
 508
 509         mutex_lock(&core_lock);
 510         /* "above" here means "above or equal to", sigh */
 511         res = idr_get_new_above(&i2c_adapter_idr, adapter,
 512                                 __i2c_first_dynamic_bus_num, &id);
 513         mutex_unlock(&core_lock);
 514
 515         if (res < 0) {
 516                 if (res == -EAGAIN)
 517                         goto retry;
 518                 return res;
 519         }
 520
 521         adapter->nr = id;
 522         return i2c_register_adapter(adapter);
 523 }
 524 EXPORT_SYMBOL(i2c_add_adapter);
 525
 526 /**
 527  * i2c_add_numbered_adapter - declare i2c adapter, use static bus number
 528  * @adap: the adapter to register (with adap->nr initialized)
 529  * Context: can sleep
 530  *
 531  * This routine is used to declare an I2C adapter when its bus number
 532  * matters.  For example, use it for I2C adapters from system-on-chip CPUs,
 533  * or otherwise built in to the system's mainboard, and where i2c_board_info
 534  * is used to properly configure I2C devices.
 535  *
 536  * If no devices have pre-been declared for this bus, then be sure to
 537  * register the adapter before any dynamically allocated ones.  Otherwise
 538  * the required bus ID may not be available.
 539  *
 540  * When this returns zero, the specified adapter became available for
 541  * clients using the bus number provided in adap->nr.  Also, the table
 542  * of I2C devices pre-declared using i2c_register_board_info() is scanned,
 543  * and the appropriate driver model device nodes are created.  Otherwise, a
 544  * negative errno value is returned.
 545  */
 546 int i2c_add_numbered_adapter(struct i2c_adapter *adap)
 547 {
 548         int     id;
 549         int     status;
 550
 551         if (adap->nr & ~MAX_ID_MASK)
 552                 return -EINVAL;
 553
 554 retry:
 555         if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0)
 556                 return -ENOMEM;
 557
 558         mutex_lock(&core_lock);
 559         /* "above" here means "above or equal to", sigh;
 560          * we need the "equal to" result to force the result
 561          */
 562         status = idr_get_new_above(&i2c_adapter_idr, adap, adap->nr, &id);
 563         if (status == 0 && id != adap->nr) {
 564                 status = -EBUSY;
 565                 idr_remove(&i2c_adapter_idr, id);
 566         }
 567         mutex_unlock(&core_lock);
 568         if (status == -EAGAIN)
 569                 goto retry;
 570
 571         if (status == 0)
 572                 status = i2c_register_adapter(adap);
 573         return status;
 574 }
 575 EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter);
 576
 577 static int i2c_do_del_adapter(struct device_driver *d, void *data)
 578 {
 579         struct i2c_driver *driver = to_i2c_driver(d);
 580         struct i2c_adapter *adapter = data;
 581         struct i2c_client *client, *_n;
 582         int res;
 583
 584         /* Remove the devices we created ourselves */
 585         list_for_each_entry_safe(client, _n, &driver->clients, detected) {
 586                 if (client->adapter == adapter) {
 587                         dev_dbg(&adapter->dev, "Removing %s at 0x%x\n",
 588                                 client->name, client->addr);
 589                         list_del(&client->detected);
 590                         i2c_unregister_device(client);
 591                 }
 592         }
 593
 594         if (!driver->detach_adapter)
 595                 return 0;
 596         res = driver->detach_adapter(adapter);
 597         if (res)
 598                 dev_err(&adapter->dev, "detach_adapter failed (%d) "
 599                         "for driver [%s]\n", res, driver->driver.name);
 600         return res;
 601 }
 602
 603 /**
 604  * i2c_del_adapter - unregister I2C adapter
 605  * @adap: the adapter being unregistered
 606  * Context: can sleep
 607  *
 608  * This unregisters an I2C adapter which was previously registered
 609  * by @i2c_add_adapter or @i2c_add_numbered_adapter.
 610  */
 611 int i2c_del_adapter(struct i2c_adapter *adap)
 612 {
 613         struct i2c_client *client, *_n;
 614         int res = 0;
 615
 616         mutex_lock(&core_lock);
 617
 618         /* First make sure that this adapter was ever added */
 619         if (idr_find(&i2c_adapter_idr, adap->nr) != adap) {
 620                 pr_debug("i2c-core: attempting to delete unregistered "
 621                          "adapter [%s]\n", adap->name);
 622                 res = -EINVAL;
 623                 goto out_unlock;
 624         }
 625
 626         /* Tell drivers about this removal */
 627         res = bus_for_each_drv(&i2c_bus_type, NULL, adap,
 628                                i2c_do_del_adapter);
 629         if (res)
 630                 goto out_unlock;
 631
 632         /* detach any active clients. This must be done first, because
 633          * it can fail; in which case we give up. */
 634         list_for_each_entry_safe_reverse(client, _n, &adap->clients, list) {
 635                 struct i2c_driver       *driver;
 636
 637                 driver = client->driver;
 638
 639                 /* new style, follow standard driver model */
 640                 if (!driver || is_newstyle_driver(driver)) {
 641                         i2c_unregister_device(client);
 642                         continue;
 643                 }
 644
 645                 /* legacy drivers create and remove clients themselves */
 646                 if ((res = driver->detach_client(client))) {
 647                         dev_err(&adap->dev, "detach_client failed for client "
 648                                 "[%s] at address 0x%02x\n", client->name,
 649                                 client->addr);
 650                         goto out_unlock;
 651                 }
 652         }
 653
 654         /* clean up the sysfs representation */
 655         init_completion(&adap->dev_released);
 656         device_unregister(&adap->dev);
 657
 658         /* wait for sysfs to drop all references */
 659         wait_for_completion(&adap->dev_released);
 660
 661         /* free bus id */
 662         idr_remove(&i2c_adapter_idr, adap->nr);
 663
 664         dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name);
 665
 666         /* Clear the device structure in case this adapter is ever going to be
 667            added again */
 668         memset(&adap->dev, 0, sizeof(adap->dev));
 669
 670  out_unlock:
 671         mutex_unlock(&core_lock);
 672         return res;
 673 }
 674 EXPORT_SYMBOL(i2c_del_adapter);
 675
 676
 677 /* ------------------------------------------------------------------------- */
 678
 679 static int __attach_adapter(struct device *dev, void *data)
 680 {
 681         struct i2c_adapter *adapter = to_i2c_adapter(dev);
 682         struct i2c_driver *driver = data;
 683
 684         i2c_detect(adapter, driver);
 685
 686         /* Legacy drivers scan i2c busses directly */
 687         if (driver->attach_adapter)
 688                 driver->attach_adapter(adapter);
 689
 690         return 0;
 691 }
 692
 693 /*
 694  * An i2c_driver is used with one or more i2c_client (device) nodes to access
 695  * i2c slave chips, on a bus instance associated with some i2c_adapter.  There
 696  * are two models for binding the driver to its device:  "new style" drivers
 697  * follow the standard Linux driver model and just respond to probe() calls
 698  * issued if the driver core sees they match(); "legacy" drivers create device
 699  * nodes themselves.
 700  */
 701
 702 int i2c_register_driver(struct module *owner, struct i2c_driver *driver)
 703 {
 704         int res;
 705
 706         /* Can't register until after driver model init */
 707         if (unlikely(WARN_ON(!i2c_bus_type.p)))
 708                 return -EAGAIN;
 709
 710         /* new style driver methods can't mix with legacy ones */
 711         if (is_newstyle_driver(driver)) {
 712                 if (driver->attach_adapter || driver->detach_adapter
 713                                 || driver->detach_client) {
 714                         printk(KERN_WARNING
 715                                         "i2c-core: driver [%s] is confused\n",
 716                                         driver->driver.name);
 717                         return -EINVAL;
 718                 }
 719         }
 720
 721         /* add the driver to the list of i2c drivers in the driver core */
 722         driver->driver.owner = owner;
 723         driver->driver.bus = &i2c_bus_type;
 724
 725         /* for new style drivers, when registration returns the driver core
 726          * will have called probe() for all matching-but-unbound devices.
 727          */
 728         res = driver_register(&driver->driver);
 729         if (res)
 730                 return res;
 731
 732         mutex_lock(&core_lock);
 733
 734         pr_debug("i2c-core: driver [%s] registered\n", driver->driver.name);
 735
 736         INIT_LIST_HEAD(&driver->clients);
 737         /* Walk the adapters that are already present */
 738         class_for_each_device(&i2c_adapter_class, NULL, driver,
 739                               __attach_adapter);
 740
 741         mutex_unlock(&core_lock);
 742         return 0;
 743 }
 744 EXPORT_SYMBOL(i2c_register_driver);
 745
 746 static int __detach_adapter(struct device *dev, void *data)
 747 {
 748         struct i2c_adapter *adapter = to_i2c_adapter(dev);
 749         struct i2c_driver *driver = data;
 750         struct i2c_client *client, *_n;
 751
 752         list_for_each_entry_safe(client, _n, &driver->clients, detected) {
 753                 dev_dbg(&adapter->dev, "Removing %s at 0x%x\n",
 754                         client->name, client->addr);
 755                 list_del(&client->detected);
 756                 i2c_unregister_device(client);
 757         }
 758
 759         if (is_newstyle_driver(driver))
 760                 return 0;
 761
 762         /* Have a look at each adapter, if clients of this driver are still
 763          * attached. If so, detach them to be able to kill the driver
 764          * afterwards.
 765          */
 766         if (driver->detach_adapter) {
 767                 if (driver->detach_adapter(adapter))
 768                         dev_err(&adapter->dev,
 769                                 "detach_adapter failed for driver [%s]\n",
 770                                 driver->driver.name);
 771         } else {
 772                 struct i2c_client *client, *_n;
 773
 774                 list_for_each_entry_safe(client, _n, &adapter->clients, list) {
 775                         if (client->driver != driver)
 776                                 continue;
 777                         dev_dbg(&adapter->dev,
 778                                 "detaching client [%s] at 0x%02x\n",
 779                                 client->name, client->addr);
 780                         if (driver->detach_client(client))
 781                                 dev_err(&adapter->dev, "detach_client "
 782                                         "failed for client [%s] at 0x%02x\n",
 783                                         client->name, client->addr);
 784                 }
 785         }
 786
 787         return 0;
 788 }
 789
 790 /**
 791  * i2c_del_driver - unregister I2C driver
 792  * @driver: the driver being unregistered
 793  * Context: can sleep
 794  */
 795 void i2c_del_driver(struct i2c_driver *driver)
 796 {
 797         mutex_lock(&core_lock);
 798
 799         class_for_each_device(&i2c_adapter_class, NULL, driver,
 800                               __detach_adapter);
 801
 802         driver_unregister(&driver->driver);
 803         pr_debug("i2c-core: driver [%s] unregistered\n", driver->driver.name);
 804
 805         mutex_unlock(&core_lock);
 806 }
 807 EXPORT_SYMBOL(i2c_del_driver);
 808
 809 /* ------------------------------------------------------------------------- */
 810
 811 static int __i2c_check_addr(struct device *dev, void *addrp)
 812 {
 813         struct i2c_client       *client = i2c_verify_client(dev);
 814         int                     addr = *(int *)addrp;
 815
 816         if (client && client->addr == addr)
 817                 return -EBUSY;
 818         return 0;
 819 }
 820
 821 static int i2c_check_addr(struct i2c_adapter *adapter, int addr)
 822 {
 823         return device_for_each_child(&adapter->dev, &addr, __i2c_check_addr);
 824 }
 825
 826 int i2c_attach_client(struct i2c_client *client)
 827 {
 828         struct i2c_adapter *adapter = client->adapter;
 829         int res;
 830
 831         /* Check for address business */
 832         res = i2c_check_addr(adapter, client->addr);
 833         if (res)
 834                 return res;
 835
 836         client->dev.parent = &client->adapter->dev;
 837         client->dev.bus = &i2c_bus_type;
 838
 839         if (client->driver)
 840                 client->dev.driver = &client->driver->driver;
 841
 842         if (client->driver && !is_newstyle_driver(client->driver)) {
 843                 client->dev.release = i2c_client_release;
 844                 dev_set_uevent_suppress(&client->dev, 1);
 845         } else
 846                 client->dev.release = i2c_client_dev_release;
 847
 848         dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adapter),
 849                      client->addr);
 850         res = device_register(&client->dev);
 851         if (res)
 852                 goto out_err;
 853
 854         mutex_lock(&adapter->clist_lock);
 855         list_add_tail(&client->list, &adapter->clients);
 856         mutex_unlock(&adapter->clist_lock);
 857
 858         dev_dbg(&adapter->dev, "client [%s] registered with bus id %s\n",
 859                 client->name, dev_name(&client->dev));
 860
 861         if (adapter->client_register)  {
 862                 if (adapter->client_register(client)) {
 863                         dev_dbg(&adapter->dev, "client_register "
 864                                 "failed for client [%s] at 0x%02x\n",
 865                                 client->name, client->addr);
 866                 }
 867         }
 868
 869         return 0;
 870
 871 out_err:
 872         dev_err(&adapter->dev, "Failed to attach i2c client %s at 0x%02x "
 873                 "(%d)\n", client->name, client->addr, res);
 874         return res;
 875 }
 876 EXPORT_SYMBOL(i2c_attach_client);
 877
 878 int i2c_detach_client(struct i2c_client *client)
 879 {
 880         struct i2c_adapter *adapter = client->adapter;
 881         int res = 0;
 882
 883         if (adapter->client_unregister)  {
 884                 res = adapter->client_unregister(client);
 885                 if (res) {
 886                         dev_err(&client->dev,
 887                                 "client_unregister [%s] failed, "
 888                                 "client not detached\n", client->name);
 889                         goto out;
 890                 }
 891         }
 892
 893         mutex_lock(&adapter->clist_lock);
 894         list_del(&client->list);
 895         mutex_unlock(&adapter->clist_lock);
 896
 897         init_completion(&client->released);
 898         device_unregister(&client->dev);
 899         wait_for_completion(&client->released);
 900
 901  out:
 902         return res;
 903 }
 904 EXPORT_SYMBOL(i2c_detach_client);
 905
 906 /**
 907  * i2c_use_client - increments the reference count of the i2c client structure
 908  * @client: the client being referenced
 909  *
 910  * Each live reference to a client should be refcounted. The driver model does
 911  * that automatically as part of driver binding, so that most drivers don't
 912  * need to do this explicitly: they hold a reference until they're unbound
 913  * from the device.
 914  *
 915  * A pointer to the client with the incremented reference counter is returned.
 916  */
 917 struct i2c_client *i2c_use_client(struct i2c_client *client)
 918 {
 919         if (client && get_device(&client->dev))
 920                 return client;
 921         return NULL;
 922 }
 923 EXPORT_SYMBOL(i2c_use_client);
 924
 925 /**
 926  * i2c_release_client - release a use of the i2c client structure
 927  * @client: the client being no longer referenced
 928  *
 929  * Must be called when a user of a client is finished with it.
 930  */
 931 void i2c_release_client(struct i2c_client *client)
 932 {
 933         if (client)
 934                 put_device(&client->dev);
 935 }
 936 EXPORT_SYMBOL(i2c_release_client);
 937
 938 struct i2c_cmd_arg {
 939         unsigned        cmd;
 940         void            *arg;
 941 };
 942
 943 static int i2c_cmd(struct device *dev, void *_arg)
 944 {
 945         struct i2c_client       *client = i2c_verify_client(dev);
 946         struct i2c_cmd_arg      *arg = _arg;
 947
 948         if (client && client->driver && client->driver->command)
 949                 client->driver->command(client, arg->cmd, arg->arg);
 950         return 0;
 951 }
 952
 953 void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg)
 954 {
 955         struct i2c_cmd_arg      cmd_arg;
 956
 957         cmd_arg.cmd = cmd;
 958         cmd_arg.arg = arg;
 959         device_for_each_child(&adap->dev, &cmd_arg, i2c_cmd);
 960 }
 961 EXPORT_SYMBOL(i2c_clients_command);
 962
 963 static int __init i2c_init(void)
 964 {
 965         int retval;
 966
 967         retval = bus_register(&i2c_bus_type);
 968         if (retval)
 969                 return retval;
 970         retval = class_register(&i2c_adapter_class);
 971         if (retval)
 972                 goto bus_err;
 973         retval = i2c_add_driver(&dummy_driver);
 974         if (retval)
 975                 goto class_err;
 976         return 0;
 977
 978 class_err:
 979         class_unregister(&i2c_adapter_class);
 980 bus_err:
 981         bus_unregister(&i2c_bus_type);
 982         return retval;
 983 }
 984
 985 static void __exit i2c_exit(void)
 986 {
 987         i2c_del_driver(&dummy_driver);
 988         class_unregister(&i2c_adapter_class);
 989         bus_unregister(&i2c_bus_type);
 990 }
 991
 992 /* We must initialize early, because some subsystems register i2c drivers
 993  * in subsys_initcall() code, but are linked (and initialized) before i2c.
 994  */
 995 postcore_initcall(i2c_init);
 996 module_exit(i2c_exit);
 997
 998 /* ----------------------------------------------------
 999  * the functional interface to the i2c busses.
1000  * ----------------------------------------------------
1001  */
1002
1003 /**
1004  * i2c_transfer - execute a single or combined I2C message
1005  * @adap: Handle to I2C bus
1006  * @msgs: One or more messages to execute before STOP is issued to
1007  *      terminate the operation; each message begins with a START.
1008  * @num: Number of messages to be executed.
1009  *
1010  * Returns negative errno, else the number of messages executed.
1011  *
1012  * Note that there is no requirement that each message be sent to
1013  * the same slave address, although that is the most common model.
1014  */
1015 int i2c_transfer(struct i2c_adapter * adap, struct i2c_msg *msgs, int num)
1016 {
1017         int ret;
1018
1019         /* REVISIT the fault reporting model here is weak:
1020          *
1021          *  - When we get an error after receiving N bytes from a slave,
1022          *    there is no way to report "N".
1023          *
1024          *  - When we get a NAK after transmitting N bytes to a slave,
1025          *    there is no way to report "N" ... or to let the master
1026          *    continue executing the rest of this combined message, if
1027          *    that's the appropriate response.
1028          *
1029          *  - When for example "num" is two and we successfully complete
1030          *    the first message but get an error part way through the
1031          *    second, it's unclear whether that should be reported as
1032          *    one (discarding status on the second message) or errno
1033          *    (discarding status on the first one).
1034          */
1035
1036         if (adap->algo->master_xfer) {
1037 #ifdef DEBUG
1038                 for (ret = 0; ret < num; ret++) {
1039                         dev_dbg(&adap->dev, "master_xfer[%d] %c, addr=0x%02x, "
1040                                 "len=%d%s\n", ret, (msgs[ret].flags & I2C_M_RD)
1041                                 ? 'R' : 'W', msgs[ret].addr, msgs[ret].len,
1042                                 (msgs[ret].flags & I2C_M_RECV_LEN) ? "+" : "");
1043                 }
1044 #endif
1045
1046                 if (in_atomic() || irqs_disabled()) {
1047                         ret = mutex_trylock(&adap->bus_lock);
1048                         if (!ret)
1049                                 /* I2C activity is ongoing. */
1050                                 return -EAGAIN;
1051                 } else {
1052                         mutex_lock_nested(&adap->bus_lock, adap->level);
1053                 }
1054
1055                 ret = adap->algo->master_xfer(adap,msgs,num);
1056                 mutex_unlock(&adap->bus_lock);
1057
1058                 return ret;
1059         } else {
1060                 dev_dbg(&adap->dev, "I2C level transfers not supported\n");
1061                 return -EOPNOTSUPP;
1062         }
1063 }
1064 EXPORT_SYMBOL(i2c_transfer);
1065
1066 /**
1067  * i2c_master_send - issue a single I2C message in master transmit mode
1068  * @client: Handle to slave device
1069  * @buf: Data that will be written to the slave
1070  * @count: How many bytes to write
1071  *
1072  * Returns negative errno, or else the number of bytes written.
1073  */
1074 int i2c_master_send(struct i2c_client *client,const char *buf ,int count)
1075 {
1076         int ret;
1077         struct i2c_adapter *adap=client->adapter;
1078         struct i2c_msg msg;
1079
1080         msg.addr = client->addr;
1081         msg.flags = client->flags & I2C_M_TEN;
1082         msg.len = count;
1083         msg.buf = (char *)buf;
1084
1085         ret = i2c_transfer(adap, &msg, 1);
1086
1087         /* If everything went ok (i.e. 1 msg transmitted), return #bytes
1088            transmitted, else error code. */
1089         return (ret == 1) ? count : ret;
1090 }
1091 EXPORT_SYMBOL(i2c_master_send);
1092
1093 /**
1094  * i2c_master_recv - issue a single I2C message in master receive mode
1095  * @client: Handle to slave device
1096  * @buf: Where to store data read from slave
1097  * @count: How many bytes to read
1098  *
1099  * Returns negative errno, or else the number of bytes read.
1100  */
1101 int i2c_master_recv(struct i2c_client *client, char *buf ,int count)
1102 {
1103         struct i2c_adapter *adap=client->adapter;
1104         struct i2c_msg msg;
1105         int ret;
1106
1107         msg.addr = client->addr;
1108         msg.flags = client->flags & I2C_M_TEN;
1109         msg.flags |= I2C_M_RD;
1110         msg.len = count;
1111         msg.buf = buf;
1112
1113         ret = i2c_transfer(adap, &msg, 1);
1114
1115         /* If everything went ok (i.e. 1 msg transmitted), return #bytes
1116            transmitted, else error code. */
1117         return (ret == 1) ? count : ret;
1118 }
1119 EXPORT_SYMBOL(i2c_master_recv);
1120
1121 /* ----------------------------------------------------
1122  * the i2c address scanning function
1123  * Will not work for 10-bit addresses!
1124  * ----------------------------------------------------
1125  */
1126 static int i2c_probe_address(struct i2c_adapter *adapter, int addr, int kind,
1127                              int (*found_proc) (struct i2c_adapter *, int, int))
1128 {
1129         int err;
1130
1131         /* Make sure the address is valid */
1132         if (addr < 0x03 || addr > 0x77) {
1133                 dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n",
1134                          addr);
1135                 return -EINVAL;
1136         }
1137
1138         /* Skip if already in use */
1139         if (i2c_check_addr(adapter, addr))
1140                 return 0;
1141
1142         /* Make sure there is something at this address, unless forced */
1143         if (kind < 0) {
1144                 if (i2c_smbus_xfer(adapter, addr, 0, 0, 0,
1145                                    I2C_SMBUS_QUICK, NULL) < 0)
1146                         return 0;
1147
1148                 /* prevent 24RF08 corruption */
1149                 if ((addr & ~0x0f) == 0x50)
1150                         i2c_smbus_xfer(adapter, addr, 0, 0, 0,
1151                                        I2C_SMBUS_QUICK, NULL);
1152         }
1153
1154         /* Finally call the custom detection function */
1155         err = found_proc(adapter, addr, kind);
1156         /* -ENODEV can be returned if there is a chip at the given address
1157            but it isn't supported by this chip driver. We catch it here as
1158            this isn't an error. */
1159         if (err == -ENODEV)
1160                 err = 0;
1161
1162         if (err)
1163                 dev_warn(&adapter->dev, "Client creation failed at 0x%x (%d)\n",
1164                          addr, err);
1165         return err;
1166 }
1167
1168 int i2c_probe(struct i2c_adapter *adapter,
1169               const struct i2c_client_address_data *address_data,
1170               int (*found_proc) (struct i2c_adapter *, int, int))
1171 {
1172         int i, err;
1173         int adap_id = i2c_adapter_id(adapter);
1174
1175         /* Force entries are done first, and are not affected by ignore
1176            entries */
1177         if (address_data->forces) {
1178                 const unsigned short * const *forces = address_data->forces;
1179                 int kind;
1180
1181                 for (kind = 0; forces[kind]; kind++) {
1182                         for (i = 0; forces[kind][i] != I2C_CLIENT_END;
1183                              i += 2) {
1184                                 if (forces[kind][i] == adap_id
1185                                  || forces[kind][i] == ANY_I2C_BUS) {
1186                                         dev_dbg(&adapter->dev, "found force "
1187                                                 "parameter for adapter %d, "
1188                                                 "addr 0x%02x, kind %d\n",
1189                                                 adap_id, forces[kind][i + 1],
1190                                                 kind);
1191                                         err = i2c_probe_address(adapter,
1192                                                 forces[kind][i + 1],
1193                                                 kind, found_proc);
1194                                         if (err)
1195                                                 return err;
1196                                 }
1197                         }
1198                 }
1199         }
1200
1201         /* Stop here if we can't use SMBUS_QUICK */
1202         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_QUICK)) {
1203                 if (address_data->probe[0] == I2C_CLIENT_END
1204                  && address_data->normal_i2c[0] == I2C_CLIENT_END)
1205                         return 0;
1206
1207                 dev_dbg(&adapter->dev, "SMBus Quick command not supported, "
1208                         "can't probe for chips\n");
1209                 return -EOPNOTSUPP;
1210         }
1211
1212         /* Probe entries are done second, and are not affected by ignore
1213            entries either */
1214         for (i = 0; address_data->probe[i] != I2C_CLIENT_END; i += 2) {
1215                 if (address_data->probe[i] == adap_id
1216                  || address_data->probe[i] == ANY_I2C_BUS) {
1217                         dev_dbg(&adapter->dev, "found probe parameter for "
1218                                 "adapter %d, addr 0x%02x\n", adap_id,
1219                                 address_data->probe[i + 1]);
1220                         err = i2c_probe_address(adapter,
1221                                                 address_data->probe[i + 1],
1222                                                 -1, found_proc);
1223                         if (err)
1224                                 return err;
1225                 }
1226         }
1227
1228         /* Normal entries are done last, unless shadowed by an ignore entry */
1229         for (i = 0; address_data->normal_i2c[i] != I2C_CLIENT_END; i += 1) {
1230                 int j, ignore;
1231
1232                 ignore = 0;
1233                 for (j = 0; address_data->ignore[j] != I2C_CLIENT_END;
1234                      j += 2) {
1235                         if ((address_data->ignore[j] == adap_id ||
1236                              address_data->ignore[j] == ANY_I2C_BUS)
1237                          && address_data->ignore[j + 1]
1238                             == address_data->normal_i2c[i]) {
1239                                 dev_dbg(&adapter->dev, "found ignore "
1240                                         "parameter for adapter %d, "
1241                                         "addr 0x%02x\n", adap_id,
1242                                         address_data->ignore[j + 1]);
1243                                 ignore = 1;
1244                                 break;
1245                         }
1246                 }
1247                 if (ignore)
1248                         continue;
1249
1250                 dev_dbg(&adapter->dev, "found normal entry for adapter %d, "
1251                         "addr 0x%02x\n", adap_id,
1252                         address_data->normal_i2c[i]);
1253                 err = i2c_probe_address(adapter, address_data->normal_i2c[i],
1254                                         -1, found_proc);
1255                 if (err)
1256                         return err;
1257         }
1258
1259         return 0;
1260 }
1261 EXPORT_SYMBOL(i2c_probe);
1262
1263 /* Separate detection function for new-style drivers */
1264 static int i2c_detect_address(struct i2c_client *temp_client, int kind,
1265                               struct i2c_driver *driver)
1266 {
1267         struct i2c_board_info info;
1268         struct i2c_adapter *adapter = temp_client->adapter;
1269         int addr = temp_client->addr;
1270         int err;
1271
1272         /* Make sure the address is valid */
1273         if (addr < 0x03 || addr > 0x77) {
1274                 dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n",
1275                          addr);
1276                 return -EINVAL;
1277         }
1278
1279         /* Skip if already in use */
1280         if (i2c_check_addr(adapter, addr))
1281                 return 0;
1282
1283         /* Make sure there is something at this address, unless forced */
1284         if (kind < 0) {
1285                 if (i2c_smbus_xfer(adapter, addr, 0, 0, 0,
1286                                    I2C_SMBUS_QUICK, NULL) < 0)
1287                         return 0;
1288
1289                 /* prevent 24RF08 corruption */
1290                 if ((addr & ~0x0f) == 0x50)
1291                         i2c_smbus_xfer(adapter, addr, 0, 0, 0,
1292                                        I2C_SMBUS_QUICK, NULL);
1293         }
1294
1295         /* Finally call the custom detection function */
1296         memset(&info, 0, sizeof(struct i2c_board_info));
1297         info.addr = addr;
1298         err = driver->detect(temp_client, kind, &info);
1299         if (err) {
1300                 /* -ENODEV is returned if the detection fails. We catch it
1301                    here as this isn't an error. */
1302                 return err == -ENODEV ? 0 : err;
1303         }
1304
1305         /* Consistency check */
1306         if (info.type[0] == '\0') {
1307                 dev_err(&adapter->dev, "%s detection function provided "
1308                         "no name for 0x%x\n", driver->driver.name,
1309                         addr);
1310         } else {
1311                 struct i2c_client *client;
1312
1313                 /* Detection succeeded, instantiate the device */
1314                 dev_dbg(&adapter->dev, "Creating %s at 0x%02x\n",
1315                         info.type, info.addr);
1316                 client = i2c_new_device(adapter, &info);
1317                 if (client)
1318                         list_add_tail(&client->detected, &driver->clients);
1319                 else
1320                         dev_err(&adapter->dev, "Failed creating %s at 0x%02x\n",
1321                                 info.type, info.addr);
1322         }
1323         return 0;
1324 }
1325
1326 static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver)
1327 {
1328         const struct i2c_client_address_data *address_data;
1329         struct i2c_client *temp_client;
1330         int i, err = 0;
1331         int adap_id = i2c_adapter_id(adapter);
1332
1333         address_data = driver->address_data;
1334         if (!driver->detect || !address_data)
1335                 return 0;
1336
1337         /* Set up a temporary client to help detect callback */
1338         temp_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL);
1339         if (!temp_client)
1340                 return -ENOMEM;
1341         temp_client->adapter = adapter;
1342
1343         /* Force entries are done first, and are not affected by ignore
1344            entries */
1345         if (address_data->forces) {
1346                 const unsigned short * const *forces = address_data->forces;
1347                 int kind;
1348
1349                 for (kind = 0; forces[kind]; kind++) {
1350                         for (i = 0; forces[kind][i] != I2C_CLIENT_END;
1351                              i += 2) {
1352                                 if (forces[kind][i] == adap_id
1353                                  || forces[kind][i] == ANY_I2C_BUS) {
1354                                         dev_dbg(&adapter->dev, "found force "
1355                                                 "parameter for adapter %d, "
1356                                                 "addr 0x%02x, kind %d\n",
1357                                                 adap_id, forces[kind][i + 1],
1358                                                 kind);
1359                                         temp_client->addr = forces[kind][i + 1];
1360                                         err = i2c_detect_address(temp_client,
1361                                                 kind, driver);
1362                                         if (err)
1363                                                 goto exit_free;
1364                                 }
1365                         }
1366                 }
1367         }
1368
1369         /* Stop here if the classes do not match */
1370         if (!(adapter->class & driver->class))
1371                 goto exit_free;
1372
1373         /* Stop here if we can't use SMBUS_QUICK */
1374         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_QUICK)) {
1375                 if (address_data->probe[0] == I2C_CLIENT_END
1376                  && address_data->normal_i2c[0] == I2C_CLIENT_END)
1377                         goto exit_free;
1378
1379                 dev_warn(&adapter->dev, "SMBus Quick command not supported, "
1380                          "can't probe for chips\n");
1381                 err = -EOPNOTSUPP;
1382                 goto exit_free;
1383         }
1384
1385         /* Probe entries are done second, and are not affected by ignore
1386            entries either */
1387         for (i = 0; address_data->probe[i] != I2C_CLIENT_END; i += 2) {
1388                 if (address_data->probe[i] == adap_id
1389                  || address_data->probe[i] == ANY_I2C_BUS) {
1390                         dev_dbg(&adapter->dev, "found probe parameter for "
1391                                 "adapter %d, addr 0x%02x\n", adap_id,
1392                                 address_data->probe[i + 1]);
1393                         temp_client->addr = address_data->probe[i + 1];
1394                         err = i2c_detect_address(temp_client, -1, driver);
1395                         if (err)
1396                                 goto exit_free;
1397                 }
1398         }
1399
1400         /* Normal entries are done last, unless shadowed by an ignore entry */
1401         for (i = 0; address_data->normal_i2c[i] != I2C_CLIENT_END; i += 1) {
1402                 int j, ignore;
1403
1404                 ignore = 0;
1405                 for (j = 0; address_data->ignore[j] != I2C_CLIENT_END;
1406                      j += 2) {
1407                         if ((address_data->ignore[j] == adap_id ||
1408                              address_data->ignore[j] == ANY_I2C_BUS)
1409                          && address_data->ignore[j + 1]
1410                             == address_data->normal_i2c[i]) {
1411                                 dev_dbg(&adapter->dev, "found ignore "
1412                                         "parameter for adapter %d, "
1413                                         "addr 0x%02x\n", adap_id,
1414                                         address_data->ignore[j + 1]);
1415                                 ignore = 1;
1416                                 break;
1417                         }
1418                 }
1419                 if (ignore)
1420                         continue;
1421
1422                 dev_dbg(&adapter->dev, "found normal entry for adapter %d, "
1423                         "addr 0x%02x\n", adap_id,
1424                         address_data->normal_i2c[i]);
1425                 temp_client->addr = address_data->normal_i2c[i];
1426                 err = i2c_detect_address(temp_client, -1, driver);
1427                 if (err)
1428                         goto exit_free;
1429         }
1430
1431  exit_free:
1432         kfree(temp_client);
1433         return err;
1434 }
1435
1436 struct i2c_client *
1437 i2c_new_probed_device(struct i2c_adapter *adap,
1438                       struct i2c_board_info *info,
1439                       unsigned short const *addr_list)
1440 {
1441         int i;
1442
1443         /* Stop here if the bus doesn't support probing */
1444         if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE)) {
1445                 dev_err(&adap->dev, "Probing not supported\n");
1446                 return NULL;
1447         }
1448
1449         for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) {
1450                 /* Check address validity */
1451                 if (addr_list[i] < 0x03 || addr_list[i] > 0x77) {
1452                         dev_warn(&adap->dev, "Invalid 7-bit address "
1453                                  "0x%02x\n", addr_list[i]);
1454                         continue;
1455                 }
1456
1457                 /* Check address availability */
1458                 if (i2c_check_addr(adap, addr_list[i])) {
1459                         dev_dbg(&adap->dev, "Address 0x%02x already in "
1460                                 "use, not probing\n", addr_list[i]);
1461                         continue;
1462                 }
1463
1464                 /* Test address responsiveness
1465                    The default probe method is a quick write, but it is known
1466                    to corrupt the 24RF08 EEPROMs due to a state machine bug,
1467                    and could also irreversibly write-protect some EEPROMs, so
1468                    for address ranges 0x30-0x37 and 0x50-0x5f, we use a byte
1469                    read instead. Also, some bus drivers don't implement
1470                    quick write, so we fallback to a byte read it that case
1471                    too. */
1472                 if ((addr_list[i] & ~0x07) == 0x30
1473                  || (addr_list[i] & ~0x0f) == 0x50
1474                  || !i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK)) {
1475                         union i2c_smbus_data data;
1476
1477                         if (i2c_smbus_xfer(adap, addr_list[i], 0,
1478                                            I2C_SMBUS_READ, 0,
1479                                            I2C_SMBUS_BYTE, &data) >= 0)
1480                                 break;
1481                 } else {
1482                         if (i2c_smbus_xfer(adap, addr_list[i], 0,
1483                                            I2C_SMBUS_WRITE, 0,
1484                                            I2C_SMBUS_QUICK, NULL) >= 0)
1485                                 break;
1486                 }
1487         }
1488
1489         if (addr_list[i] == I2C_CLIENT_END) {
1490                 dev_dbg(&adap->dev, "Probing failed, no device found\n");
1491                 return NULL;
1492         }
1493
1494         info->addr = addr_list[i];
1495         return i2c_new_device(adap, info);
1496 }
1497 EXPORT_SYMBOL_GPL(i2c_new_probed_device);
1498
1499 struct i2c_adapter* i2c_get_adapter(int id)
1500 {
1501         struct i2c_adapter *adapter;
1502
1503         mutex_lock(&core_lock);
1504         adapter = (struct i2c_adapter *)idr_find(&i2c_adapter_idr, id);
1505         if (adapter && !try_module_get(adapter->owner))
1506                 adapter = NULL;
1507
1508         mutex_unlock(&core_lock);
1509         return adapter;
1510 }
1511 EXPORT_SYMBOL(i2c_get_adapter);
1512
1513 void i2c_put_adapter(struct i2c_adapter *adap)
1514 {
1515         module_put(adap->owner);
1516 }
1517 EXPORT_SYMBOL(i2c_put_adapter);
1518
1519 /* The SMBus parts */
1520
1521 #define POLY    (0x1070U << 3)
1522 static u8
1523 crc8(u16 data)
1524 {
1525         int i;
1526
1527         for(i = 0; i < 8; i++) {
1528                 if (data & 0x8000)
1529                         data = data ^ POLY;
1530                 data = data << 1;
1531         }
1532         return (u8)(data >> 8);
1533 }
1534
1535 /* Incremental CRC8 over count bytes in the array pointed to by p */
1536 static u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count)
1537 {
1538         int i;
1539
1540         for(i = 0; i < count; i++)
1541                 crc = crc8((crc ^ p[i]) << 8);
1542         return crc;
1543 }
1544
1545 /* Assume a 7-bit address, which is reasonable for SMBus */
1546 static u8 i2c_smbus_msg_pec(u8 pec, struct i2c_msg *msg)
1547 {
1548         /* The address will be sent first */
1549         u8 addr = (msg->addr << 1) | !!(msg->flags & I2C_M_RD);
1550         pec = i2c_smbus_pec(pec, &addr, 1);
1551
1552         /* The data buffer follows */
1553         return i2c_smbus_pec(pec, msg->buf, msg->len);
1554 }
1555
1556 /* Used for write only transactions */
1557 static inline void i2c_smbus_add_pec(struct i2c_msg *msg)
1558 {
1559         msg->buf[msg->len] = i2c_smbus_msg_pec(0, msg);
1560         msg->len++;
1561 }
1562
1563 /* Return <0 on CRC error
1564    If there was a write before this read (most cases) we need to take the
1565    partial CRC from the write part into account.
1566    Note that this function does modify the message (we need to decrease the
1567    message length to hide the CRC byte from the caller). */
1568 static int i2c_smbus_check_pec(u8 cpec, struct i2c_msg *msg)
1569 {
1570         u8 rpec = msg->buf[--msg->len];
1571         cpec = i2c_smbus_msg_pec(cpec, msg);
1572
1573         if (rpec != cpec) {
1574                 pr_debug("i2c-core: Bad PEC 0x%02x vs. 0x%02x\n",
1575                         rpec, cpec);
1576                 return -EBADMSG;
1577         }
1578         return 0;
1579 }
1580
1581 /**
1582  * i2c_smbus_read_byte - SMBus "receive byte" protocol
1583  * @client: Handle to slave device
1584  *
1585  * This executes the SMBus "receive byte" protocol, returning negative errno
1586  * else the byte received from the device.
1587  */
1588 s32 i2c_smbus_read_byte(struct i2c_client *client)
1589 {
1590         union i2c_smbus_data data;
1591         int status;
1592
1593         status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
1594                                 I2C_SMBUS_READ, 0,
1595                                 I2C_SMBUS_BYTE, &data);
1596         return (status < 0) ? status : data.byte;
1597 }
1598 EXPORT_SYMBOL(i2c_smbus_read_byte);
1599
1600 /**
1601  * i2c_smbus_write_byte - SMBus "send byte" protocol
1602  * @client: Handle to slave device
1603  * @value: Byte to be sent
1604  *
1605  * This executes the SMBus "send byte" protocol, returning negative errno
1606  * else zero on success.
1607  */
1608 s32 i2c_smbus_write_byte(struct i2c_client *client, u8 value)
1609 {
1610         return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
1611                               I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL);
1612 }
1613 EXPORT_SYMBOL(i2c_smbus_write_byte);
1614
1615 /**
1616  * i2c_smbus_read_byte_data - SMBus "read byte" protocol
1617  * @client: Handle to slave device
1618  * @command: Byte interpreted by slave
1619  *
1620  * This executes the SMBus "read byte" protocol, returning negative errno
1621  * else a data byte received from the device.
1622  */
1623 s32 i2c_smbus_read_byte_data(struct i2c_client *client, u8 command)
1624 {
1625         union i2c_smbus_data data;
1626         int status;
1627
1628         status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
1629                                 I2C_SMBUS_READ, command,
1630                                 I2C_SMBUS_BYTE_DATA, &data);
1631         return (status < 0) ? status : data.byte;
1632 }
1633 EXPORT_SYMBOL(i2c_smbus_read_byte_data);
1634
1635 /**
1636  * i2c_smbus_write_byte_data - SMBus "write byte" protocol
1637  * @client: Handle to slave device
1638  * @command: Byte interpreted by slave
1639  * @value: Byte being written
1640  *
1641  * This executes the SMBus "write byte" protocol, returning negative errno
1642  * else zero on success.
1643  */
1644 s32 i2c_smbus_write_byte_data(struct i2c_client *client, u8 command, u8 value)
1645 {
1646         union i2c_smbus_data data;
1647         data.byte = value;
1648         return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
1649                               I2C_SMBUS_WRITE,command,
1650                               I2C_SMBUS_BYTE_DATA,&data);
1651 }
1652 EXPORT_SYMBOL(i2c_smbus_write_byte_data);
1653
1654 /**
1655  * i2c_smbus_read_word_data - SMBus "read word" protocol
1656  * @client: Handle to slave device
1657  * @command: Byte interpreted by slave
1658  *
1659  * This executes the SMBus "read word" protocol, returning negative errno
1660  * else a 16-bit unsigned "word" received from the device.
1661  */
1662 s32 i2c_smbus_read_word_data(struct i2c_client *client, u8 command)
1663 {
1664         union i2c_smbus_data data;
1665         int status;
1666
1667         status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
1668                                 I2C_SMBUS_READ, command,
1669                                 I2C_SMBUS_WORD_DATA, &data);
1670         return (status < 0) ? status : data.word;
1671 }
1672 EXPORT_SYMBOL(i2c_smbus_read_word_data);
1673
1674 /**
1675  * i2c_smbus_write_word_data - SMBus "write word" protocol
1676  * @client: Handle to slave device
1677  * @command: Byte interpreted by slave
1678  * @value: 16-bit "word" being written
1679  *
1680  * This executes the SMBus "write word" protocol, returning negative errno
1681  * else zero on success.
1682  */
1683 s32 i2c_smbus_write_word_data(struct i2c_client *client, u8 command, u16 value)
1684 {
1685         union i2c_smbus_data data;
1686         data.word = value;
1687         return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
1688                               I2C_SMBUS_WRITE,command,
1689                               I2C_SMBUS_WORD_DATA,&data);
1690 }
1691 EXPORT_SYMBOL(i2c_smbus_write_word_data);
1692
1693 /**
1694  * i2c_smbus_process_call - SMBus "process call" protocol
1695  * @client: Handle to slave device
1696  * @command: Byte interpreted by slave
1697  * @value: 16-bit "word" being written
1698  *
1699  * This executes the SMBus "process call" protocol, returning negative errno
1700  * else a 16-bit unsigned "word" received from the device.
1701  */
1702 s32 i2c_smbus_process_call(struct i2c_client *client, u8 command, u16 value)
1703 {
1704         union i2c_smbus_data data;
1705         int status;
1706         data.word = value;
1707
1708         status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
1709                                 I2C_SMBUS_WRITE, command,
1710                                 I2C_SMBUS_PROC_CALL, &data);
1711         return (status < 0) ? status : data.word;
1712 }
1713 EXPORT_SYMBOL(i2c_smbus_process_call);
1714
1715 /**
1716  * i2c_smbus_read_block_data - SMBus "block read" protocol
1717  * @client: Handle to slave device
1718  * @command: Byte interpreted by slave
1719  * @values: Byte array into which data will be read; big enough to hold
1720  *      the data returned by the slave.  SMBus allows at most 32 bytes.
1721  *
1722  * This executes the SMBus "block read" protocol, returning negative errno
1723  * else the number of data bytes in the slave's response.
1724  *
1725  * Note that using this function requires that the client's adapter support
1726  * the I2C_FUNC_SMBUS_READ_BLOCK_DATA functionality.  Not all adapter drivers
1727  * support this; its emulation through I2C messaging relies on a specific
1728  * mechanism (I2C_M_RECV_LEN) which may not be implemented.
1729  */
1730 s32 i2c_smbus_read_block_data(struct i2c_client *client, u8 command,
1731                               u8 *values)
1732 {
1733         union i2c_smbus_data data;
1734         int status;
1735
1736         status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
1737                                 I2C_SMBUS_READ, command,
1738                                 I2C_SMBUS_BLOCK_DATA, &data);
1739         if (status)
1740                 return status;
1741
1742         memcpy(values, &data.block[1], data.block[0]);
1743         return data.block[0];
1744 }
1745 EXPORT_SYMBOL(i2c_smbus_read_block_data);
1746
1747 /**
1748  * i2c_smbus_write_block_data - SMBus "block write" protocol
1749  * @client: Handle to slave device
1750  * @command: Byte interpreted by slave
1751  * @length: Size of data block; SMBus allows at most 32 bytes
1752  * @values: Byte array which will be written.
1753  *
1754  * This executes the SMBus "block write" protocol, returning negative errno
1755  * else zero on success.
1756  */
1757 s32 i2c_smbus_write_block_data(struct i2c_client *client, u8 command,
1758                                u8 length, const u8 *values)
1759 {
1760         union i2c_smbus_data data;
1761
1762         if (length > I2C_SMBUS_BLOCK_MAX)
1763                 length = I2C_SMBUS_BLOCK_MAX;
1764         data.block[0] = length;
1765         memcpy(&data.block[1], values, length);
1766         return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
1767                               I2C_SMBUS_WRITE,command,
1768                               I2C_SMBUS_BLOCK_DATA,&data);
1769 }
1770 EXPORT_SYMBOL(i2c_smbus_write_block_data);
1771
1772 /* Returns the number of read bytes */
1773 s32 i2c_smbus_read_i2c_block_data(struct i2c_client *client, u8 command,
1774                                   u8 length, u8 *values)
1775 {
1776         union i2c_smbus_data data;
1777         int status;
1778
1779         if (length > I2C_SMBUS_BLOCK_MAX)
1780                 length = I2C_SMBUS_BLOCK_MAX;
1781         data.block[0] = length;
1782         status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
1783                                 I2C_SMBUS_READ, command,
1784                                 I2C_SMBUS_I2C_BLOCK_DATA, &data);
1785         if (status < 0)
1786                 return status;
1787
1788         memcpy(values, &data.block[1], data.block[0]);
1789         return data.block[0];
1790 }
1791 EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data);
1792
1793 s32 i2c_smbus_write_i2c_block_data(struct i2c_client *client, u8 command,
1794                                    u8 length, const u8 *values)
1795 {
1796         union i2c_smbus_data data;
1797
1798         if (length > I2C_SMBUS_BLOCK_MAX)
1799                 length = I2C_SMBUS_BLOCK_MAX;
1800         data.block[0] = length;
1801         memcpy(data.block + 1, values, length);
1802         return i2c_smbus_xfer(client->adapter, client->addr, client->flags,
1803                               I2C_SMBUS_WRITE, command,
1804                               I2C_SMBUS_I2C_BLOCK_DATA, &data);
1805 }
1806 EXPORT_SYMBOL(i2c_smbus_write_i2c_block_data);
1807
1808 /* Simulate a SMBus command using the i2c protocol
1809    No checking of parameters is done!  */
1810 static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr,
1811                                    unsigned short flags,
1812                                    char read_write, u8 command, int size,
1813                                    union i2c_smbus_data * data)
1814 {
1815         /* So we need to generate a series of msgs. In the case of writing, we
1816           need to use only one message; when reading, we need two. We initialize
1817           most things with sane defaults, to keep the code below somewhat
1818           simpler. */
1819         unsigned char msgbuf0[I2C_SMBUS_BLOCK_MAX+3];
1820         unsigned char msgbuf1[I2C_SMBUS_BLOCK_MAX+2];
1821         int num = read_write == I2C_SMBUS_READ?2:1;
1822         struct i2c_msg msg[2] = { { addr, flags, 1, msgbuf0 },
1823                                   { addr, flags | I2C_M_RD, 0, msgbuf1 }
1824                                 };
1825         int i;
1826         u8 partial_pec = 0;
1827         int status;
1828
1829         msgbuf0[0] = command;
1830         switch(size) {
1831         case I2C_SMBUS_QUICK:
1832                 msg[0].len = 0;
1833                 /* Special case: The read/write field is used as data */
1834                 msg[0].flags = flags | (read_write == I2C_SMBUS_READ ?
1835                                         I2C_M_RD : 0);
1836                 num = 1;
1837                 break;
1838         case I2C_SMBUS_BYTE:
1839                 if (read_write == I2C_SMBUS_READ) {
1840                         /* Special case: only a read! */
1841                         msg[0].flags = I2C_M_RD | flags;
1842                         num = 1;
1843                 }
1844                 break;
1845         case I2C_SMBUS_BYTE_DATA:
1846                 if (read_write == I2C_SMBUS_READ)
1847                         msg[1].len = 1;
1848                 else {
1849                         msg[0].len = 2;
1850                         msgbuf0[1] = data->byte;
1851                 }
1852                 break;
1853         case I2C_SMBUS_WORD_DATA:
1854                 if (read_write == I2C_SMBUS_READ)
1855                         msg[1].len = 2;
1856                 else {
1857                         msg[0].len=3;
1858                         msgbuf0[1] = data->word & 0xff;
1859                         msgbuf0[2] = data->word >> 8;
1860                 }
1861                 break;
1862         case I2C_SMBUS_PROC_CALL:
1863                 num = 2; /* Special case */
1864                 read_write = I2C_SMBUS_READ;
1865                 msg[0].len = 3;
1866                 msg[1].len = 2;
1867                 msgbuf0[1] = data->word & 0xff;
1868                 msgbuf0[2] = data->word >> 8;
1869                 break;
1870         case I2C_SMBUS_BLOCK_DATA:
1871                 if (read_write == I2C_SMBUS_READ) {
1872                         msg[1].flags |= I2C_M_RECV_LEN;
1873                         msg[1].len = 1; /* block length will be added by
1874                                            the underlying bus driver */
1875                 } else {
1876                         msg[0].len = data->block[0] + 2;
1877                         if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 2) {
1878                                 dev_err(&adapter->dev,
1879                                         "Invalid block write size %d\n",
1880                                         data->block[0]);
1881                                 return -EINVAL;
1882                         }
1883                         for (i = 1; i < msg[0].len; i++)
1884                                 msgbuf0[i] = data->block[i-1];
1885                 }
1886                 break;
1887         case I2C_SMBUS_BLOCK_PROC_CALL:
1888                 num = 2; /* Another special case */
1889                 read_write = I2C_SMBUS_READ;
1890                 if (data->block[0] > I2C_SMBUS_BLOCK_MAX) {
1891                         dev_err(&adapter->dev,
1892                                 "Invalid block write size %d\n",
1893                                 data->block[0]);
1894                         return -EINVAL;
1895                 }
1896                 msg[0].len = data->block[0] + 2;
1897                 for (i = 1; i < msg[0].len; i++)
1898                         msgbuf0[i] = data->block[i-1];
1899                 msg[1].flags |= I2C_M_RECV_LEN;
1900                 msg[1].len = 1; /* block length will be added by
1901                                    the underlying bus driver */
1902                 break;
1903         case I2C_SMBUS_I2C_BLOCK_DATA:
1904                 if (read_write == I2C_SMBUS_READ) {
1905                         msg[1].len = data->block[0];
1906                 } else {
1907                         msg[0].len = data->block[0] + 1;
1908                         if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 1) {
1909                                 dev_err(&adapter->dev,
1910                                         "Invalid block write size %d\n",
1911                                         data->block[0]);
1912                                 return -EINVAL;
1913                         }
1914                         for (i = 1; i <= data->block[0]; i++)
1915                                 msgbuf0[i] = data->block[i];
1916                 }
1917                 break;
1918         default:
1919                 dev_err(&adapter->dev, "Unsupported transaction %d\n", size);
1920                 return -EOPNOTSUPP;
1921         }
1922
1923         i = ((flags & I2C_CLIENT_PEC) && size != I2C_SMBUS_QUICK
1924                                       && size != I2C_SMBUS_I2C_BLOCK_DATA);
1925         if (i) {
1926                 /* Compute PEC if first message is a write */
1927                 if (!(msg[0].flags & I2C_M_RD)) {
1928                         if (num == 1) /* Write only */
1929                                 i2c_smbus_add_pec(&msg[0]);
1930                         else /* Write followed by read */
1931                                 partial_pec = i2c_smbus_msg_pec(0, &msg[0]);
1932                 }
1933                 /* Ask for PEC if last message is a read */
1934                 if (msg[num-1].flags & I2C_M_RD)
1935                         msg[num-1].len++;
1936         }
1937
1938         status = i2c_transfer(adapter, msg, num);
1939         if (status < 0)
1940                 return status;
1941
1942         /* Check PEC if last message is a read */
1943         if (i && (msg[num-1].flags & I2C_M_RD)) {
1944                 status = i2c_smbus_check_pec(partial_pec, &msg[num-1]);
1945                 if (status < 0)
1946                         return status;
1947         }
1948
1949         if (read_write == I2C_SMBUS_READ)
1950                 switch(size) {
1951                         case I2C_SMBUS_BYTE:
1952                                 data->byte = msgbuf0[0];
1953                                 break;
1954                         case I2C_SMBUS_BYTE_DATA:
1955                                 data->byte = msgbuf1[0];
1956                                 break;
1957                         case I2C_SMBUS_WORD_DATA:
1958                         case I2C_SMBUS_PROC_CALL:
1959                                 data->word = msgbuf1[0] | (msgbuf1[1] << 8);
1960                                 break;
1961                         case I2C_SMBUS_I2C_BLOCK_DATA:
1962                                 for (i = 0; i < data->block[0]; i++)
1963                                         data->block[i+1] = msgbuf1[i];
1964                                 break;
1965                         case I2C_SMBUS_BLOCK_DATA:
1966                         case I2C_SMBUS_BLOCK_PROC_CALL:
1967                                 for (i = 0; i < msgbuf1[0] + 1; i++)
1968                                         data->block[i] = msgbuf1[i];
1969                                 break;
1970                 }
1971         return 0;
1972 }
1973
1974 /**
1975  * i2c_smbus_xfer - execute SMBus protocol operations
1976  * @adapter: Handle to I2C bus
1977  * @addr: Address of SMBus slave on that bus
1978  * @flags: I2C_CLIENT_* flags (usually zero or I2C_CLIENT_PEC)
1979  * @read_write: I2C_SMBUS_READ or I2C_SMBUS_WRITE
1980  * @command: Byte interpreted by slave, for protocols which use such bytes
1981  * @protocol: SMBus protocol operation to execute, such as I2C_SMBUS_PROC_CALL
1982  * @data: Data to be read or written
1983  *
1984  * This executes an SMBus protocol operation, and returns a negative
1985  * errno code else zero on success.
1986  */
1987 s32 i2c_smbus_xfer(struct i2c_adapter * adapter, u16 addr, unsigned short flags,
1988                    char read_write, u8 command, int protocol,
1989                    union i2c_smbus_data * data)
1990 {
1991         s32 res;
1992
1993         flags &= I2C_M_TEN | I2C_CLIENT_PEC;
1994
1995         if (adapter->algo->smbus_xfer) {
1996                 mutex_lock(&adapter->bus_lock);
1997                 res = adapter->algo->smbus_xfer(adapter,addr,flags,read_write,
1998                                                 command, protocol, data);
1999                 mutex_unlock(&adapter->bus_lock);
2000         } else
2001                 res = i2c_smbus_xfer_emulated(adapter,addr,flags,read_write,
2002                                               command, protocol, data);
2003
2004         return res;
2005 }
2006 EXPORT_SYMBOL(i2c_smbus_xfer);
2007
2008 MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>");
2009 MODULE_DESCRIPTION("I2C-Bus main module");
2010 MODULE_LICENSE("GPL");