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);
  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);
  61         return rc;
  62 }
  63
  64 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 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 struct device_driver i2c_adapter_driver = {
  88         .owner = THIS_MODULE,
  89         .name = "i2c_adapter",
  90         .bus = &i2c_bus_type,
  91         .probe = i2c_device_probe,
  92         .remove = i2c_device_remove,
  93 };
  94
  95 static void i2c_adapter_class_dev_release(struct class_device *dev)
  96 {
  97         struct i2c_adapter *adap = class_dev_to_i2c_adapter(dev);
  98         complete(&adap->class_dev_released);
  99 }
 100
 101 struct class i2c_adapter_class = {
 102         .owner =        THIS_MODULE,
 103         .name =         "i2c-adapter",
 104         .release =      &i2c_adapter_class_dev_release,
 105 };
 106
 107 static ssize_t show_adapter_name(struct device *dev, struct device_attribute *attr, char *buf)
 108 {
 109         struct i2c_adapter *adap = dev_to_i2c_adapter(dev);
 110         return sprintf(buf, "%s\n", adap->name);
 111 }
 112 static DEVICE_ATTR(name, S_IRUGO, show_adapter_name, NULL);
 113
 114
 115 static void i2c_client_release(struct device *dev)
 116 {
 117         struct i2c_client *client = to_i2c_client(dev);
 118         complete(&client->released);
 119 }
 120
 121 static ssize_t show_client_name(struct device *dev, struct device_attribute *attr, char *buf)
 122 {
 123         struct i2c_client *client = to_i2c_client(dev);
 124         return sprintf(buf, "%s\n", client->name);
 125 }
 126
 127 /*
 128  * We can't use the DEVICE_ATTR() macro here as we want the same filename for a
 129  * different type of a device.  So beware if the DEVICE_ATTR() macro ever
 130  * changes, this definition will also have to change.
 131  */
 132 static struct device_attribute dev_attr_client_name = {
 133         .attr   = {.name = "name", .mode = S_IRUGO, .owner = THIS_MODULE },
 134         .show   = &show_client_name,
 135 };
 136
 137
 138 /* ---------------------------------------------------
 139  * registering functions
 140  * ---------------------------------------------------
 141  */
 142
 143 /* -----
 144  * i2c_add_adapter is called from within the algorithm layer,
 145  * when a new hw adapter registers. A new device is register to be
 146  * available for clients.
 147  */
 148 int i2c_add_adapter(struct i2c_adapter *adap)
 149 {
 150         int id, res = 0;
 151         struct list_head   *item;
 152         struct i2c_driver  *driver;
 153
 154         down(&core_lists);
 155
 156         if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0) {
 157                 res = -ENOMEM;
 158                 goto out_unlock;
 159         }
 160
 161         res = idr_get_new(&i2c_adapter_idr, adap, &id);
 162         if (res < 0) {
 163                 if (res == -EAGAIN)
 164                         res = -ENOMEM;
 165                 goto out_unlock;
 166         }
 167
 168         adap->nr =  id & MAX_ID_MASK;
 169         init_MUTEX(&adap->bus_lock);
 170         init_MUTEX(&adap->clist_lock);
 171         list_add_tail(&adap->list,&adapters);
 172         INIT_LIST_HEAD(&adap->clients);
 173
 174         /* Add the adapter to the driver core.
 175          * If the parent pointer is not set up,
 176          * we add this adapter to the host bus.
 177          */
 178         if (adap->dev.parent == NULL)
 179                 adap->dev.parent = &platform_bus;
 180         sprintf(adap->dev.bus_id, "i2c-%d", adap->nr);
 181         adap->dev.driver = &i2c_adapter_driver;
 182         adap->dev.release = &i2c_adapter_dev_release;
 183         device_register(&adap->dev);
 184         device_create_file(&adap->dev, &dev_attr_name);
 185
 186         /* Add this adapter to the i2c_adapter class */
 187         memset(&adap->class_dev, 0x00, sizeof(struct class_device));
 188         adap->class_dev.dev = &adap->dev;
 189         adap->class_dev.class = &i2c_adapter_class;
 190         strlcpy(adap->class_dev.class_id, adap->dev.bus_id, BUS_ID_SIZE);
 191         class_device_register(&adap->class_dev);
 192
 193         dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name);
 194
 195         /* inform drivers of new adapters */
 196         list_for_each(item,&drivers) {
 197                 driver = list_entry(item, struct i2c_driver, list);
 198                 if (driver->flags & I2C_DF_NOTIFY)
 199                         /* We ignore the return code; if it fails, too bad */
 200                         driver->attach_adapter(adap);
 201         }
 202
 203 out_unlock:
 204         up(&core_lists);
 205         return res;
 206 }
 207
 208
 209 int i2c_del_adapter(struct i2c_adapter *adap)
 210 {
 211         struct list_head  *item, *_n;
 212         struct i2c_adapter *adap_from_list;
 213         struct i2c_driver *driver;
 214         struct i2c_client *client;
 215         int res = 0;
 216
 217         down(&core_lists);
 218
 219         /* First make sure that this adapter was ever added */
 220         list_for_each_entry(adap_from_list, &adapters, list) {
 221                 if (adap_from_list == adap)
 222                         break;
 223         }
 224         if (adap_from_list != adap) {
 225                 pr_debug("i2c-core: attempting to delete unregistered "
 226                          "adapter [%s]\n", adap->name);
 227                 res = -EINVAL;
 228                 goto out_unlock;
 229         }
 230
 231         list_for_each(item,&drivers) {
 232                 driver = list_entry(item, struct i2c_driver, list);
 233                 if (driver->detach_adapter)
 234                         if ((res = driver->detach_adapter(adap))) {
 235                                 dev_err(&adap->dev, "detach_adapter failed "
 236                                         "for driver [%s]\n", driver->name);
 237                                 goto out_unlock;
 238                         }
 239         }
 240
 241         /* detach any active clients. This must be done first, because
 242          * it can fail; in which case we give up. */
 243         list_for_each_safe(item, _n, &adap->clients) {
 244                 client = list_entry(item, struct i2c_client, list);
 245
 246                 /* detaching devices is unconditional of the set notify
 247                  * flag, as _all_ clients that reside on the adapter
 248                  * must be deleted, as this would cause invalid states.
 249                  */
 250                 if ((res=client->driver->detach_client(client))) {
 251                         dev_err(&adap->dev, "detach_client failed for client "
 252                                 "[%s] at address 0x%02x\n", client->name,
 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 [%s] unregistered\n", adap->name);
 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.owner = driver->owner;
 297         driver->driver.name = driver->name;
 298         driver->driver.bus = &i2c_bus_type;
 299         driver->driver.probe = i2c_device_probe;
 300         driver->driver.remove = i2c_device_remove;
 301
 302         res = driver_register(&driver->driver);
 303         if (res)
 304                 goto out_unlock;
 305
 306         list_add_tail(&driver->list,&drivers);
 307         pr_debug("i2c-core: driver [%s] registered\n", driver->name);
 308
 309         /* now look for instances of driver on our adapters */
 310         if (driver->flags & I2C_DF_NOTIFY) {
 311                 list_for_each(item,&adapters) {
 312                         adapter = list_entry(item, struct i2c_adapter, list);
 313                         driver->attach_adapter(adapter);
 314                 }
 315         }
 316
 317  out_unlock:
 318         up(&core_lists);
 319         return res;
 320 }
 321
 322 int i2c_del_driver(struct i2c_driver *driver)
 323 {
 324         struct list_head   *item1, *item2, *_n;
 325         struct i2c_client  *client;
 326         struct i2c_adapter *adap;
 327
 328         int res = 0;
 329
 330         down(&core_lists);
 331
 332         /* Have a look at each adapter, if clients of this driver are still
 333          * attached. If so, detach them to be able to kill the driver
 334          * afterwards.
 335          *
 336          * 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                 if (driver->detach_adapter) {
 343                         if ((res = driver->detach_adapter(adap))) {
 344                                 dev_err(&adap->dev, "detach_adapter failed "
 345                                         "for driver [%s]\n", driver->name);
 346                                 goto out_unlock;
 347                         }
 348                 } else {
 349                         list_for_each_safe(item2, _n, &adap->clients) {
 350                                 client = list_entry(item2, struct i2c_client, list);
 351                                 if (client->driver != driver)
 352                                         continue;
 353                                 dev_dbg(&adap->dev, "detaching client [%s] "
 354                                         "at 0x%02x\n", client->name,
 355                                         client->addr);
 356                                 if ((res = driver->detach_client(client))) {
 357                                         dev_err(&adap->dev, "detach_client "
 358                                                 "failed for client [%s] at "
 359                                                 "0x%02x\n", client->name,
 360                                                 client->addr);
 361                                         goto out_unlock;
 362                                 }
 363                         }
 364                 }
 365         }
 366
 367         driver_unregister(&driver->driver);
 368         list_del(&driver->list);
 369         pr_debug("i2c-core: driver [%s] unregistered\n", driver->name);
 370
 371  out_unlock:
 372         up(&core_lists);
 373         return 0;
 374 }
 375
 376 static int __i2c_check_addr(struct i2c_adapter *adapter, unsigned int addr)
 377 {
 378         struct list_head   *item;
 379         struct i2c_client  *client;
 380
 381         list_for_each(item,&adapter->clients) {
 382                 client = list_entry(item, struct i2c_client, list);
 383                 if (client->addr == addr)
 384                         return -EBUSY;
 385         }
 386         return 0;
 387 }
 388
 389 int i2c_check_addr(struct i2c_adapter *adapter, int addr)
 390 {
 391         int rval;
 392
 393         down(&adapter->clist_lock);
 394         rval = __i2c_check_addr(adapter, addr);
 395         up(&adapter->clist_lock);
 396
 397         return rval;
 398 }
 399
 400 int i2c_attach_client(struct i2c_client *client)
 401 {
 402         struct i2c_adapter *adapter = client->adapter;
 403
 404         down(&adapter->clist_lock);
 405         if (__i2c_check_addr(client->adapter, client->addr)) {
 406                 up(&adapter->clist_lock);
 407                 return -EBUSY;
 408         }
 409         list_add_tail(&client->list,&adapter->clients);
 410         up(&adapter->clist_lock);
 411
 412         if (adapter->client_register)  {
 413                 if (adapter->client_register(client))  {
 414                         dev_dbg(&adapter->dev, "client_register "
 415                                 "failed for client [%s] at 0x%02x\n",
 416                                 client->name, client->addr);
 417                 }
 418         }
 419
 420         if (client->flags & I2C_CLIENT_ALLOW_USE)
 421                 client->usage_count = 0;
 422
 423         client->dev.parent = &client->adapter->dev;
 424         client->dev.driver = &client->driver->driver;
 425         client->dev.bus = &i2c_bus_type;
 426         client->dev.release = &i2c_client_release;
 427
 428         snprintf(&client->dev.bus_id[0], sizeof(client->dev.bus_id),
 429                 "%d-%04x", i2c_adapter_id(adapter), client->addr);
 430         dev_dbg(&adapter->dev, "client [%s] registered with bus id %s\n",
 431                 client->name, client->dev.bus_id);
 432         device_register(&client->dev);
 433         device_create_file(&client->dev, &dev_attr_client_name);
 434
 435         return 0;
 436 }
 437
 438
 439 int i2c_detach_client(struct i2c_client *client)
 440 {
 441         struct i2c_adapter *adapter = client->adapter;
 442         int res = 0;
 443
 444         if ((client->flags & I2C_CLIENT_ALLOW_USE)
 445          && (client->usage_count > 0)) {
 446                 dev_warn(&client->dev, "Client [%s] still busy, "
 447                          "can't detach\n", client->name);
 448                 return -EBUSY;
 449         }
 450
 451         if (adapter->client_unregister)  {
 452                 res = adapter->client_unregister(client);
 453                 if (res) {
 454                         dev_err(&client->dev,
 455                                 "client_unregister [%s] failed, "
 456                                 "client not detached\n", client->name);
 457                         goto out;
 458                 }
 459         }
 460
 461         down(&adapter->clist_lock);
 462         list_del(&client->list);
 463         init_completion(&client->released);
 464         device_remove_file(&client->dev, &dev_attr_client_name);
 465         device_unregister(&client->dev);
 466         up(&adapter->clist_lock);
 467         wait_for_completion(&client->released);
 468
 469  out:
 470         return res;
 471 }
 472
 473 static int i2c_inc_use_client(struct i2c_client *client)
 474 {
 475
 476         if (!try_module_get(client->driver->owner))
 477                 return -ENODEV;
 478         if (!try_module_get(client->adapter->owner)) {
 479                 module_put(client->driver->owner);
 480                 return -ENODEV;
 481         }
 482
 483         return 0;
 484 }
 485
 486 static void i2c_dec_use_client(struct i2c_client *client)
 487 {
 488         module_put(client->driver->owner);
 489         module_put(client->adapter->owner);
 490 }
 491
 492 int i2c_use_client(struct i2c_client *client)
 493 {
 494         int ret;
 495
 496         ret = i2c_inc_use_client(client);
 497         if (ret)
 498                 return ret;
 499
 500         if (client->flags & I2C_CLIENT_ALLOW_USE) {
 501                 if (client->flags & I2C_CLIENT_ALLOW_MULTIPLE_USE)
 502                         client->usage_count++;
 503                 else if (client->usage_count > 0)
 504                         goto busy;
 505                 else
 506                         client->usage_count++;
 507         }
 508
 509         return 0;
 510  busy:
 511         i2c_dec_use_client(client);
 512         return -EBUSY;
 513 }
 514
 515 int i2c_release_client(struct i2c_client *client)
 516 {
 517         if(client->flags & I2C_CLIENT_ALLOW_USE) {
 518                 if(client->usage_count>0)
 519                         client->usage_count--;
 520                 else {
 521                         pr_debug("i2c-core: %s used one too many times\n",
 522                                 __FUNCTION__);
 523                         return -EPERM;
 524                 }
 525         }
 526
 527         i2c_dec_use_client(client);
 528
 529         return 0;
 530 }
 531
 532 void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg)
 533 {
 534         struct list_head  *item;
 535         struct i2c_client *client;
 536
 537         down(&adap->clist_lock);
 538         list_for_each(item,&adap->clients) {
 539                 client = list_entry(item, struct i2c_client, list);
 540                 if (!try_module_get(client->driver->owner))
 541                         continue;
 542                 if (NULL != client->driver->command) {
 543                         up(&adap->clist_lock);
 544                         client->driver->command(client,cmd,arg);
 545                         down(&adap->clist_lock);
 546                 }
 547                 module_put(client->driver->owner);
 548        }
 549        up(&adap->clist_lock);
 550 }
 551
 552 static int __init i2c_init(void)
 553 {
 554         int retval;
 555
 556         retval = bus_register(&i2c_bus_type);
 557         if (retval)
 558                 return retval;
 559         retval = driver_register(&i2c_adapter_driver);
 560         if (retval)
 561                 return retval;
 562         return class_register(&i2c_adapter_class);
 563 }
 564
 565 static void __exit i2c_exit(void)
 566 {
 567         class_unregister(&i2c_adapter_class);
 568         driver_unregister(&i2c_adapter_driver);
 569         bus_unregister(&i2c_bus_type);
 570 }
 571
 572 subsys_initcall(i2c_init);
 573 module_exit(i2c_exit);
 574
 575 /* ----------------------------------------------------
 576  * the functional interface to the i2c busses.
 577  * ----------------------------------------------------
 578  */
 579
 580 int i2c_transfer(struct i2c_adapter * adap, struct i2c_msg *msgs, int num)
 581 {
 582         int ret;
 583
 584         if (adap->algo->master_xfer) {
 585 #ifdef DEBUG
 586                 for (ret = 0; ret < num; ret++) {
 587                         dev_dbg(&adap->dev, "master_xfer[%d] %c, addr=0x%02x, "
 588                                 "len=%d\n", ret, msgs[ret].flags & I2C_M_RD ?
 589                                 'R' : 'W', msgs[ret].addr, msgs[ret].len);
 590                 }
 591 #endif
 592
 593                 down(&adap->bus_lock);
 594                 ret = adap->algo->master_xfer(adap,msgs,num);
 595                 up(&adap->bus_lock);
 596
 597                 return ret;
 598         } else {
 599                 dev_dbg(&adap->dev, "I2C level transfers not supported\n");
 600                 return -ENOSYS;
 601         }
 602 }
 603
 604 int i2c_master_send(struct i2c_client *client,const char *buf ,int count)
 605 {
 606         int ret;
 607         struct i2c_adapter *adap=client->adapter;
 608         struct i2c_msg msg;
 609
 610         msg.addr = client->addr;
 611         msg.flags = client->flags & I2C_M_TEN;
 612         msg.len = count;
 613         msg.buf = (char *)buf;
 614
 615         ret = i2c_transfer(adap, &msg, 1);
 616
 617         /* If everything went ok (i.e. 1 msg transmitted), return #bytes
 618            transmitted, else error code. */
 619         return (ret == 1) ? count : ret;
 620 }
 621
 622 int i2c_master_recv(struct i2c_client *client, char *buf ,int count)
 623 {
 624         struct i2c_adapter *adap=client->adapter;
 625         struct i2c_msg msg;
 626         int ret;
 627
 628         msg.addr = client->addr;
 629         msg.flags = client->flags & I2C_M_TEN;
 630         msg.flags |= I2C_M_RD;
 631         msg.len = count;
 632         msg.buf = buf;
 633
 634         ret = i2c_transfer(adap, &msg, 1);
 635
 636         /* If everything went ok (i.e. 1 msg transmitted), return #bytes
 637            transmitted, else error code. */
 638         return (ret == 1) ? count : ret;
 639 }
 640
 641
 642 int i2c_control(struct i2c_client *client,
 643         unsigned int cmd, unsigned long arg)
 644 {
 645         int ret = 0;
 646         struct i2c_adapter *adap = client->adapter;
 647
 648         dev_dbg(&client->adapter->dev, "i2c ioctl, cmd: 0x%x, arg: %#lx\n", cmd, arg);
 649         switch (cmd) {
 650                 case I2C_RETRIES:
 651                         adap->retries = arg;
 652                         break;
 653                 case I2C_TIMEOUT:
 654                         adap->timeout = arg;
 655                         break;
 656                 default:
 657                         if (adap->algo->algo_control!=NULL)
 658                                 ret = adap->algo->algo_control(adap,cmd,arg);
 659         }
 660         return ret;
 661 }
 662
 663 /* ----------------------------------------------------
 664  * the i2c address scanning function
 665  * Will not work for 10-bit addresses!
 666  * ----------------------------------------------------
 667  */
 668 static int i2c_probe_address(struct i2c_adapter *adapter, int addr, int kind,
 669                              int (*found_proc) (struct i2c_adapter *, int, int))
 670 {
 671         int err;
 672
 673         /* Make sure the address is valid */
 674         if (addr < 0x03 || addr > 0x77) {
 675                 dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n",
 676                          addr);
 677                 return -EINVAL;
 678         }
 679
 680         /* Skip if already in use */
 681         if (i2c_check_addr(adapter, addr))
 682                 return 0;
 683
 684         /* Make sure there is something at this address, unless forced */
 685         if (kind < 0) {
 686                 if (i2c_smbus_xfer(adapter, addr, 0, 0, 0,
 687                                    I2C_SMBUS_QUICK, NULL) < 0)
 688                         return 0;
 689
 690                 /* prevent 24RF08 corruption */
 691                 if ((addr & ~0x0f) == 0x50)
 692                         i2c_smbus_xfer(adapter, addr, 0, 0, 0,
 693                                        I2C_SMBUS_QUICK, NULL);
 694         }
 695
 696         /* Finally call the custom detection function */
 697         err = found_proc(adapter, addr, kind);
 698
 699         /* -ENODEV can be returned if there is a chip at the given address
 700            but it isn't supported by this chip driver. We catch it here as
 701            this isn't an error. */
 702         return (err == -ENODEV) ? 0 : err;
 703 }
 704
 705 int i2c_probe(struct i2c_adapter *adapter,
 706               struct i2c_client_address_data *address_data,
 707               int (*found_proc) (struct i2c_adapter *, int, int))
 708 {
 709         int i, err;
 710         int adap_id = i2c_adapter_id(adapter);
 711
 712         /* Force entries are done first, and are not affected by ignore
 713            entries */
 714         if (address_data->forces) {
 715                 unsigned short **forces = address_data->forces;
 716                 int kind;
 717
 718                 for (kind = 0; forces[kind]; kind++) {
 719                         for (i = 0; forces[kind][i] != I2C_CLIENT_END;
 720                              i += 2) {
 721                                 if (forces[kind][i] == adap_id
 722                                  || forces[kind][i] == ANY_I2C_BUS) {
 723                                         dev_dbg(&adapter->dev, "found force "
 724                                                 "parameter for adapter %d, "
 725                                                 "addr 0x%02x, kind %d\n",
 726                                                 adap_id, forces[kind][i + 1],
 727                                                 kind);
 728                                         err = i2c_probe_address(adapter,
 729                                                 forces[kind][i + 1],
 730                                                 kind, found_proc);
 731                                         if (err)
 732                                                 return err;
 733                                 }
 734                         }
 735                 }
 736         }
 737
 738         /* Stop here if we can't use SMBUS_QUICK */
 739         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_QUICK)) {
 740                 if (address_data->probe[0] == I2C_CLIENT_END
 741                  && address_data->normal_i2c[0] == I2C_CLIENT_END)
 742                         return 0;
 743
 744                 dev_warn(&adapter->dev, "SMBus Quick command not supported, "
 745                          "can't probe for chips\n");
 746                 return -1;
 747         }
 748
 749         /* Probe entries are done second, and are not affected by ignore
 750            entries either */
 751         for (i = 0; address_data->probe[i] != I2C_CLIENT_END; i += 2) {
 752                 if (address_data->probe[i] == adap_id
 753                  || address_data->probe[i] == ANY_I2C_BUS) {
 754                         dev_dbg(&adapter->dev, "found probe parameter for "
 755                                 "adapter %d, addr 0x%02x\n", adap_id,
 756                                 address_data->probe[i + 1]);
 757                         err = i2c_probe_address(adapter,
 758                                                 address_data->probe[i + 1],
 759                                                 -1, found_proc);
 760                         if (err)
 761                                 return err;
 762                 }
 763         }
 764
 765         /* Normal entries are done last, unless shadowed by an ignore entry */
 766         for (i = 0; address_data->normal_i2c[i] != I2C_CLIENT_END; i += 1) {
 767                 int j, ignore;
 768
 769                 ignore = 0;
 770                 for (j = 0; address_data->ignore[j] != I2C_CLIENT_END;
 771                      j += 2) {
 772                         if ((address_data->ignore[j] == adap_id ||
 773                              address_data->ignore[j] == ANY_I2C_BUS)
 774                          && address_data->ignore[j + 1]
 775                             == address_data->normal_i2c[i]) {
 776                                 dev_dbg(&adapter->dev, "found ignore "
 777                                         "parameter for adapter %d, "
 778                                         "addr 0x%02x\n", adap_id,
 779                                         address_data->ignore[j + 1]);
 780                         }
 781                         ignore = 1;
 782                         break;
 783                 }
 784                 if (ignore)
 785                         continue;
 786
 787                 dev_dbg(&adapter->dev, "found normal entry for adapter %d, "
 788                         "addr 0x%02x\n", adap_id,
 789                         address_data->normal_i2c[i]);
 790                 err = i2c_probe_address(adapter, address_data->normal_i2c[i],
 791                                         -1, found_proc);
 792                 if (err)
 793                         return err;
 794         }
 795
 796         return 0;
 797 }
 798
 799 struct i2c_adapter* i2c_get_adapter(int id)
 800 {
 801         struct i2c_adapter *adapter;
 802
 803         down(&core_lists);
 804         adapter = (struct i2c_adapter *)idr_find(&i2c_adapter_idr, id);
 805         if (adapter && !try_module_get(adapter->owner))
 806                 adapter = NULL;
 807
 808         up(&core_lists);
 809         return adapter;
 810 }
 811
 812 void i2c_put_adapter(struct i2c_adapter *adap)
 813 {
 814         module_put(adap->owner);
 815 }
 816
 817 /* The SMBus parts */
 818
 819 #define POLY    (0x1070U << 3)
 820 static u8
 821 crc8(u16 data)
 822 {
 823         int i;
 824
 825         for(i = 0; i < 8; i++) {
 826                 if (data & 0x8000)
 827                         data = data ^ POLY;
 828                 data = data << 1;
 829         }
 830         return (u8)(data >> 8);
 831 }
 832
 833 /* CRC over count bytes in the first array plus the bytes in the rest
 834    array if it is non-null. rest[0] is the (length of rest) - 1
 835    and is included. */
 836 static u8 i2c_smbus_partial_pec(u8 crc, int count, u8 *first, u8 *rest)
 837 {
 838         int i;
 839
 840         for(i = 0; i < count; i++)
 841                 crc = crc8((crc ^ first[i]) << 8);
 842         if(rest != NULL)
 843                 for(i = 0; i <= rest[0]; i++)
 844                         crc = crc8((crc ^ rest[i]) << 8);
 845         return crc;
 846 }
 847
 848 static u8 i2c_smbus_pec(int count, u8 *first, u8 *rest)
 849 {
 850         return i2c_smbus_partial_pec(0, count, first, rest);
 851 }
 852
 853 /* Returns new "size" (transaction type)
 854    Note that we convert byte to byte_data and byte_data to word_data
 855    rather than invent new xxx_PEC transactions. */
 856 static int i2c_smbus_add_pec(u16 addr, u8 command, int size,
 857                              union i2c_smbus_data *data)
 858 {
 859         u8 buf[3];
 860
 861         buf[0] = addr << 1;
 862         buf[1] = command;
 863         switch(size) {
 864                 case I2C_SMBUS_BYTE:
 865                         data->byte = i2c_smbus_pec(2, buf, NULL);
 866                         size = I2C_SMBUS_BYTE_DATA;
 867                         break;
 868                 case I2C_SMBUS_BYTE_DATA:
 869                         buf[2] = data->byte;
 870                         data->word = buf[2] |
 871                                     (i2c_smbus_pec(3, buf, NULL) << 8);
 872                         size = I2C_SMBUS_WORD_DATA;
 873                         break;
 874                 case I2C_SMBUS_WORD_DATA:
 875                         /* unsupported */
 876                         break;
 877                 case I2C_SMBUS_BLOCK_DATA:
 878                         data->block[data->block[0] + 1] =
 879                                      i2c_smbus_pec(2, buf, data->block);
 880                         size = I2C_SMBUS_BLOCK_DATA_PEC;
 881                         break;
 882         }
 883         return size;
 884 }
 885
 886 static int i2c_smbus_check_pec(u16 addr, u8 command, int size, u8 partial,
 887                                union i2c_smbus_data *data)
 888 {
 889         u8 buf[3], rpec, cpec;
 890
 891         buf[1] = command;
 892         switch(size) {
 893                 case I2C_SMBUS_BYTE_DATA:
 894                         buf[0] = (addr << 1) | 1;
 895                         cpec = i2c_smbus_pec(2, buf, NULL);
 896                         rpec = data->byte;
 897                         break;
 898                 case I2C_SMBUS_WORD_DATA:
 899                         buf[0] = (addr << 1) | 1;
 900                         buf[2] = data->word & 0xff;
 901                         cpec = i2c_smbus_pec(3, buf, NULL);
 902                         rpec = data->word >> 8;
 903                         break;
 904                 case I2C_SMBUS_WORD_DATA_PEC:
 905                         /* unsupported */
 906                         cpec = rpec = 0;
 907                         break;
 908                 case I2C_SMBUS_PROC_CALL_PEC:
 909                         /* unsupported */
 910                         cpec = rpec = 0;
 911                         break;
 912                 case I2C_SMBUS_BLOCK_DATA_PEC:
 913                         buf[0] = (addr << 1);
 914                         buf[2] = (addr << 1) | 1;
 915                         cpec = i2c_smbus_pec(3, buf, data->block);
 916                         rpec = data->block[data->block[0] + 1];
 917                         break;
 918                 case I2C_SMBUS_BLOCK_PROC_CALL_PEC:
 919                         buf[0] = (addr << 1) | 1;
 920                         rpec = i2c_smbus_partial_pec(partial, 1,
 921                                                      buf, data->block);
 922                         cpec = data->block[data->block[0] + 1];
 923                         break;
 924                 default:
 925                         cpec = rpec = 0;
 926                         break;
 927         }
 928         if (rpec != cpec) {
 929                 pr_debug("i2c-core: Bad PEC 0x%02x vs. 0x%02x\n",
 930                         rpec, cpec);
 931                 return -1;
 932         }
 933         return 0;
 934 }
 935
 936 s32 i2c_smbus_write_quick(struct i2c_client *client, u8 value)
 937 {
 938         return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
 939                               value,0,I2C_SMBUS_QUICK,NULL);
 940 }
 941
 942 s32 i2c_smbus_read_byte(struct i2c_client *client)
 943 {
 944         union i2c_smbus_data data;
 945         if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
 946                            I2C_SMBUS_READ,0,I2C_SMBUS_BYTE, &data))
 947                 return -1;
 948         else
 949                 return 0x0FF & data.byte;
 950 }
 951
 952 s32 i2c_smbus_write_byte(struct i2c_client *client, u8 value)
 953 {
 954         union i2c_smbus_data data;      /* only for PEC */
 955         return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
 956                               I2C_SMBUS_WRITE,value, I2C_SMBUS_BYTE,&data);
 957 }
 958
 959 s32 i2c_smbus_read_byte_data(struct i2c_client *client, u8 command)
 960 {
 961         union i2c_smbus_data data;
 962         if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
 963                            I2C_SMBUS_READ,command, I2C_SMBUS_BYTE_DATA,&data))
 964                 return -1;
 965         else
 966                 return 0x0FF & data.byte;
 967 }
 968
 969 s32 i2c_smbus_write_byte_data(struct i2c_client *client, u8 command, u8 value)
 970 {
 971         union i2c_smbus_data data;
 972         data.byte = value;
 973         return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
 974                               I2C_SMBUS_WRITE,command,
 975                               I2C_SMBUS_BYTE_DATA,&data);
 976 }
 977
 978 s32 i2c_smbus_read_word_data(struct i2c_client *client, u8 command)
 979 {
 980         union i2c_smbus_data data;
 981         if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
 982                            I2C_SMBUS_READ,command, I2C_SMBUS_WORD_DATA, &data))
 983                 return -1;
 984         else
 985                 return 0x0FFFF & data.word;
 986 }
 987
 988 s32 i2c_smbus_write_word_data(struct i2c_client *client, u8 command, u16 value)
 989 {
 990         union i2c_smbus_data data;
 991         data.word = value;
 992         return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
 993                               I2C_SMBUS_WRITE,command,
 994                               I2C_SMBUS_WORD_DATA,&data);
 995 }
 996
 997 s32 i2c_smbus_write_block_data(struct i2c_client *client, u8 command,
 998                                u8 length, u8 *values)
 999 {
1000         union i2c_smbus_data data;
1001         int i;
1002         if (length > I2C_SMBUS_BLOCK_MAX)
1003                 length = I2C_SMBUS_BLOCK_MAX;
1004         for (i = 1; i <= length; i++)
1005                 data.block[i] = values[i-1];
1006         data.block[0] = length;
1007         return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
1008                               I2C_SMBUS_WRITE,command,
1009                               I2C_SMBUS_BLOCK_DATA,&data);
1010 }
1011
1012 /* Returns the number of read bytes */
1013 s32 i2c_smbus_read_i2c_block_data(struct i2c_client *client, u8 command, u8 *values)
1014 {
1015         union i2c_smbus_data data;
1016         int i;
1017         if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
1018                               I2C_SMBUS_READ,command,
1019                               I2C_SMBUS_I2C_BLOCK_DATA,&data))
1020                 return -1;
1021         else {
1022                 for (i = 1; i <= data.block[0]; i++)
1023                         values[i-1] = data.block[i];
1024                 return data.block[0];
1025         }
1026 }
1027
1028 /* Simulate a SMBus command using the i2c protocol
1029    No checking of parameters is done!  */
1030 static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr,
1031                                    unsigned short flags,
1032                                    char read_write, u8 command, int size,
1033                                    union i2c_smbus_data * data)
1034 {
1035         /* So we need to generate a series of msgs. In the case of writing, we
1036           need to use only one message; when reading, we need two. We initialize
1037           most things with sane defaults, to keep the code below somewhat
1038           simpler. */
1039         unsigned char msgbuf0[I2C_SMBUS_BLOCK_MAX+3];
1040         unsigned char msgbuf1[I2C_SMBUS_BLOCK_MAX+2];
1041         int num = read_write == I2C_SMBUS_READ?2:1;
1042         struct i2c_msg msg[2] = { { addr, flags, 1, msgbuf0 },
1043                                   { addr, flags | I2C_M_RD, 0, msgbuf1 }
1044                                 };
1045         int i;
1046
1047         msgbuf0[0] = command;
1048         switch(size) {
1049         case I2C_SMBUS_QUICK:
1050                 msg[0].len = 0;
1051                 /* Special case: The read/write field is used as data */
1052                 msg[0].flags = flags | (read_write==I2C_SMBUS_READ)?I2C_M_RD:0;
1053                 num = 1;
1054                 break;
1055         case I2C_SMBUS_BYTE:
1056                 if (read_write == I2C_SMBUS_READ) {
1057                         /* Special case: only a read! */
1058                         msg[0].flags = I2C_M_RD | flags;
1059                         num = 1;
1060                 }
1061                 break;
1062         case I2C_SMBUS_BYTE_DATA:
1063                 if (read_write == I2C_SMBUS_READ)
1064                         msg[1].len = 1;
1065                 else {
1066                         msg[0].len = 2;
1067                         msgbuf0[1] = data->byte;
1068                 }
1069                 break;
1070         case I2C_SMBUS_WORD_DATA:
1071                 if (read_write == I2C_SMBUS_READ)
1072                         msg[1].len = 2;
1073                 else {
1074                         msg[0].len=3;
1075                         msgbuf0[1] = data->word & 0xff;
1076                         msgbuf0[2] = (data->word >> 8) & 0xff;
1077                 }
1078                 break;
1079         case I2C_SMBUS_PROC_CALL:
1080                 num = 2; /* Special case */
1081                 read_write = I2C_SMBUS_READ;
1082                 msg[0].len = 3;
1083                 msg[1].len = 2;
1084                 msgbuf0[1] = data->word & 0xff;
1085                 msgbuf0[2] = (data->word >> 8) & 0xff;
1086                 break;
1087         case I2C_SMBUS_BLOCK_DATA:
1088         case I2C_SMBUS_BLOCK_DATA_PEC:
1089                 if (read_write == I2C_SMBUS_READ) {
1090                         dev_err(&adapter->dev, "Block read not supported "
1091                                "under I2C emulation!\n");
1092                         return -1;
1093                 } else {
1094                         msg[0].len = data->block[0] + 2;
1095                         if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 2) {
1096                                 dev_err(&adapter->dev, "smbus_access called with "
1097                                        "invalid block write size (%d)\n",
1098                                        data->block[0]);
1099                                 return -1;
1100                         }
1101                         if(size == I2C_SMBUS_BLOCK_DATA_PEC)
1102                                 (msg[0].len)++;
1103                         for (i = 1; i < msg[0].len; i++)
1104                                 msgbuf0[i] = data->block[i-1];
1105                 }
1106                 break;
1107         case I2C_SMBUS_BLOCK_PROC_CALL:
1108         case I2C_SMBUS_BLOCK_PROC_CALL_PEC:
1109                 dev_dbg(&adapter->dev, "Block process call not supported "
1110                        "under I2C emulation!\n");
1111                 return -1;
1112         case I2C_SMBUS_I2C_BLOCK_DATA:
1113                 if (read_write == I2C_SMBUS_READ) {
1114                         msg[1].len = I2C_SMBUS_BLOCK_MAX;
1115                 } else {
1116                         msg[0].len = data->block[0] + 1;
1117                         if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 1) {
1118                                 dev_err(&adapter->dev, "i2c_smbus_xfer_emulated called with "
1119                                        "invalid block write size (%d)\n",
1120                                        data->block[0]);
1121                                 return -1;
1122                         }
1123                         for (i = 1; i <= data->block[0]; i++)
1124                                 msgbuf0[i] = data->block[i];
1125                 }
1126                 break;
1127         default:
1128                 dev_err(&adapter->dev, "smbus_access called with invalid size (%d)\n",
1129                        size);
1130                 return -1;
1131         }
1132
1133         if (i2c_transfer(adapter, msg, num) < 0)
1134                 return -1;
1135
1136         if (read_write == I2C_SMBUS_READ)
1137                 switch(size) {
1138                         case I2C_SMBUS_BYTE:
1139                                 data->byte = msgbuf0[0];
1140                                 break;
1141                         case I2C_SMBUS_BYTE_DATA:
1142                                 data->byte = msgbuf1[0];
1143                                 break;
1144                         case I2C_SMBUS_WORD_DATA:
1145                         case I2C_SMBUS_PROC_CALL:
1146                                 data->word = msgbuf1[0] | (msgbuf1[1] << 8);
1147                                 break;
1148                         case I2C_SMBUS_I2C_BLOCK_DATA:
1149                                 /* fixed at 32 for now */
1150                                 data->block[0] = I2C_SMBUS_BLOCK_MAX;
1151                                 for (i = 0; i < I2C_SMBUS_BLOCK_MAX; i++)
1152                                         data->block[i+1] = msgbuf1[i];
1153                                 break;
1154                 }
1155         return 0;
1156 }
1157
1158
1159 s32 i2c_smbus_xfer(struct i2c_adapter * adapter, u16 addr, unsigned short flags,
1160                    char read_write, u8 command, int size,
1161                    union i2c_smbus_data * data)
1162 {
1163         s32 res;
1164         int swpec = 0;
1165         u8 partial = 0;
1166
1167         flags &= I2C_M_TEN | I2C_CLIENT_PEC;
1168         if((flags & I2C_CLIENT_PEC) &&
1169            !(i2c_check_functionality(adapter, I2C_FUNC_SMBUS_HWPEC_CALC))) {
1170                 swpec = 1;
1171                 if(read_write == I2C_SMBUS_READ &&
1172                    size == I2C_SMBUS_BLOCK_DATA)
1173                         size = I2C_SMBUS_BLOCK_DATA_PEC;
1174                 else if(size == I2C_SMBUS_PROC_CALL)
1175                         size = I2C_SMBUS_PROC_CALL_PEC;
1176                 else if(size == I2C_SMBUS_BLOCK_PROC_CALL) {
1177                         i2c_smbus_add_pec(addr, command,
1178                                           I2C_SMBUS_BLOCK_DATA, data);
1179                         partial = data->block[data->block[0] + 1];
1180                         size = I2C_SMBUS_BLOCK_PROC_CALL_PEC;
1181                 } else if(read_write == I2C_SMBUS_WRITE &&
1182                           size != I2C_SMBUS_QUICK &&
1183                           size != I2C_SMBUS_I2C_BLOCK_DATA)
1184                         size = i2c_smbus_add_pec(addr, command, size, data);
1185         }
1186
1187         if (adapter->algo->smbus_xfer) {
1188                 down(&adapter->bus_lock);
1189                 res = adapter->algo->smbus_xfer(adapter,addr,flags,read_write,
1190                                                 command,size,data);
1191                 up(&adapter->bus_lock);
1192         } else
1193                 res = i2c_smbus_xfer_emulated(adapter,addr,flags,read_write,
1194                                               command,size,data);
1195
1196         if(res >= 0 && swpec &&
1197            size != I2C_SMBUS_QUICK && size != I2C_SMBUS_I2C_BLOCK_DATA &&
1198            (read_write == I2C_SMBUS_READ || size == I2C_SMBUS_PROC_CALL_PEC ||
1199             size == I2C_SMBUS_BLOCK_PROC_CALL_PEC)) {
1200                 if(i2c_smbus_check_pec(addr, command, size, partial, data))
1201                         return -1;
1202         }
1203         return res;
1204 }
1205
1206
1207 /* Next four are needed by i2c-isa */
1208 EXPORT_SYMBOL_GPL(i2c_adapter_dev_release);
1209 EXPORT_SYMBOL_GPL(i2c_adapter_driver);
1210 EXPORT_SYMBOL_GPL(i2c_adapter_class);
1211 EXPORT_SYMBOL_GPL(i2c_bus_type);
1212
1213 EXPORT_SYMBOL(i2c_add_adapter);
1214 EXPORT_SYMBOL(i2c_del_adapter);
1215 EXPORT_SYMBOL(i2c_add_driver);
1216 EXPORT_SYMBOL(i2c_del_driver);
1217 EXPORT_SYMBOL(i2c_attach_client);
1218 EXPORT_SYMBOL(i2c_detach_client);
1219 EXPORT_SYMBOL(i2c_use_client);
1220 EXPORT_SYMBOL(i2c_release_client);
1221 EXPORT_SYMBOL(i2c_clients_command);
1222 EXPORT_SYMBOL(i2c_check_addr);
1223
1224 EXPORT_SYMBOL(i2c_master_send);
1225 EXPORT_SYMBOL(i2c_master_recv);
1226 EXPORT_SYMBOL(i2c_control);
1227 EXPORT_SYMBOL(i2c_transfer);
1228 EXPORT_SYMBOL(i2c_get_adapter);
1229 EXPORT_SYMBOL(i2c_put_adapter);
1230 EXPORT_SYMBOL(i2c_probe);
1231
1232 EXPORT_SYMBOL(i2c_smbus_xfer);
1233 EXPORT_SYMBOL(i2c_smbus_write_quick);
1234 EXPORT_SYMBOL(i2c_smbus_read_byte);
1235 EXPORT_SYMBOL(i2c_smbus_write_byte);
1236 EXPORT_SYMBOL(i2c_smbus_read_byte_data);
1237 EXPORT_SYMBOL(i2c_smbus_write_byte_data);
1238 EXPORT_SYMBOL(i2c_smbus_read_word_data);
1239 EXPORT_SYMBOL(i2c_smbus_write_word_data);
1240 EXPORT_SYMBOL(i2c_smbus_write_block_data);
1241 EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data);
1242
1243 MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>");
1244 MODULE_DESCRIPTION("I2C-Bus main module");
1245 MODULE_LICENSE("GPL");