drivers/extcon/extcon-class.c

   1 /*
   2  *  drivers/extcon/extcon_class.c
   3  *
   4  *  External connector (extcon) class driver
   5  *
   6  * Copyright (C) 2012 Samsung Electronics
   7  * Author: Donggeun Kim <dg77.kim@samsung.com>
   8  * Author: MyungJoo Ham <myungjoo.ham@samsung.com>
   9  *
  10  * based on android/drivers/switch/switch_class.c
  11  * Copyright (C) 2008 Google, Inc.
  12  * Author: Mike Lockwood <lockwood@android.com>
  13  *
  14  * This software is licensed under the terms of the GNU General Public
  15  * License version 2, as published by the Free Software Foundation, and
  16  * may be copied, distributed, and modified under those terms.
  17  *
  18  * This program is distributed in the hope that it will be useful,
  19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21  * GNU General Public License for more details.
  22  *
  23 */
  24
  25 #include <linux/module.h>
  26 #include <linux/types.h>
  27 #include <linux/init.h>
  28 #include <linux/device.h>
  29 #include <linux/fs.h>
  30 #include <linux/err.h>
  31 #include <linux/extcon.h>
  32 #include <linux/slab.h>
  33 #include <linux/sysfs.h>
  34
  35 /*
  36  * extcon_cable_name suggests the standard cable names for commonly used
  37  * cable types.
  38  *
  39  * However, please do not use extcon_cable_name directly for extcon_dev
  40  * struct's supported_cable pointer unless your device really supports
  41  * every single port-type of the following cable names. Please choose cable
  42  * names that are actually used in your extcon device.
  43  */
  44 const char extcon_cable_name[][CABLE_NAME_MAX + 1] = {
  45         [EXTCON_USB]            = "USB",
  46         [EXTCON_USB_HOST]       = "USB-Host",
  47         [EXTCON_TA]             = "TA",
  48         [EXTCON_FAST_CHARGER]   = "Fast-charger",
  49         [EXTCON_SLOW_CHARGER]   = "Slow-charger",
  50         [EXTCON_CHARGE_DOWNSTREAM]      = "Charge-downstream",
  51         [EXTCON_HDMI]           = "HDMI",
  52         [EXTCON_MHL]            = "MHL",
  53         [EXTCON_DVI]            = "DVI",
  54         [EXTCON_VGA]            = "VGA",
  55         [EXTCON_DOCK]           = "Dock",
  56         [EXTCON_LINE_IN]        = "Line-in",
  57         [EXTCON_LINE_OUT]       = "Line-out",
  58         [EXTCON_MIC_IN]         = "Microphone",
  59         [EXTCON_HEADPHONE_OUT]  = "Headphone",
  60         [EXTCON_SPDIF_IN]       = "SPDIF-in",
  61         [EXTCON_SPDIF_OUT]      = "SPDIF-out",
  62         [EXTCON_VIDEO_IN]       = "Video-in",
  63         [EXTCON_VIDEO_OUT]      = "Video-out",
  64         [EXTCON_MECHANICAL]     = "Mechanical",
  65 };
  66
  67 static struct class *extcon_class;
  68 #if defined(CONFIG_ANDROID)
  69 static struct class_compat *switch_class;
  70 #endif /* CONFIG_ANDROID */
  71
  72 static LIST_HEAD(extcon_dev_list);
  73 static DEFINE_MUTEX(extcon_dev_list_lock);
  74
  75 /**
  76  * check_mutually_exclusive - Check if new_state violates mutually_exclusive
  77  *                          condition.
  78  * @edev:       the extcon device
  79  * @new_state:  new cable attach status for @edev
  80  *
  81  * Returns 0 if nothing violates. Returns the index + 1 for the first
  82  * violated condition.
  83  */
  84 static int check_mutually_exclusive(struct extcon_dev *edev, u32 new_state)
  85 {
  86         int i = 0;
  87
  88         if (!edev->mutually_exclusive)
  89                 return 0;
  90
  91         for (i = 0; edev->mutually_exclusive[i]; i++) {
  92                 int weight;
  93                 u32 correspondants = new_state & edev->mutually_exclusive[i];
  94
  95                 /* calculate the total number of bits set */
  96                 weight = hweight32(correspondants);
  97                 if (weight > 1)
  98                         return i + 1;
  99         }
 100
 101         return 0;
 102 }
 103
 104 static ssize_t state_show(struct device *dev, struct device_attribute *attr,
 105                           char *buf)
 106 {
 107         int i, count = 0;
 108         struct extcon_dev *edev = (struct extcon_dev *) dev_get_drvdata(dev);
 109
 110         if (edev->print_state) {
 111                 int ret = edev->print_state(edev, buf);
 112
 113                 if (ret >= 0)
 114                         return ret;
 115                 /* Use default if failed */
 116         }
 117
 118         if (edev->max_supported == 0)
 119                 return sprintf(buf, "%u\n", edev->state);
 120
 121         for (i = 0; i < SUPPORTED_CABLE_MAX; i++) {
 122                 if (!edev->supported_cable[i])
 123                         break;
 124                 count += sprintf(buf + count, "%s=%d\n",
 125                                  edev->supported_cable[i],
 126                                  !!(edev->state & (1 << i)));
 127         }
 128
 129         return count;
 130 }
 131
 132 static ssize_t state_store(struct device *dev, struct device_attribute *attr,
 133                            const char *buf, size_t count)
 134 {
 135         u32 state;
 136         ssize_t ret = 0;
 137         struct extcon_dev *edev = (struct extcon_dev *) dev_get_drvdata(dev);
 138
 139         ret = sscanf(buf, "0x%x", &state);
 140         if (ret == 0)
 141                 ret = -EINVAL;
 142         else
 143                 ret = extcon_set_state(edev, state);
 144
 145         if (ret < 0)
 146                 return ret;
 147
 148         return count;
 149 }
 150 static DEVICE_ATTR_RW(state);
 151
 152 static ssize_t name_show(struct device *dev, struct device_attribute *attr,
 153                 char *buf)
 154 {
 155         struct extcon_dev *edev = (struct extcon_dev *) dev_get_drvdata(dev);
 156
 157         /* Optional callback given by the user */
 158         if (edev->print_name) {
 159                 int ret = edev->print_name(edev, buf);
 160                 if (ret >= 0)
 161                         return ret;
 162         }
 163
 164         return sprintf(buf, "%s\n", dev_name(edev->dev));
 165 }
 166 static DEVICE_ATTR_RO(name);
 167
 168 static ssize_t cable_name_show(struct device *dev,
 169                                struct device_attribute *attr, char *buf)
 170 {
 171         struct extcon_cable *cable = container_of(attr, struct extcon_cable,
 172                                                   attr_name);
 173
 174         return sprintf(buf, "%s\n",
 175                        cable->edev->supported_cable[cable->cable_index]);
 176 }
 177
 178 static ssize_t cable_state_show(struct device *dev,
 179                                 struct device_attribute *attr, char *buf)
 180 {
 181         struct extcon_cable *cable = container_of(attr, struct extcon_cable,
 182                                                   attr_state);
 183
 184         return sprintf(buf, "%d\n",
 185                        extcon_get_cable_state_(cable->edev,
 186                                                cable->cable_index));
 187 }
 188
 189 /**
 190  * extcon_update_state() - Update the cable attach states of the extcon device
 191  *                      only for the masked bits.
 192  * @edev:       the extcon device
 193  * @mask:       the bit mask to designate updated bits.
 194  * @state:      new cable attach status for @edev
 195  *
 196  * Changing the state sends uevent with environment variable containing
 197  * the name of extcon device (envp[0]) and the state output (envp[1]).
 198  * Tizen uses this format for extcon device to get events from ports.
 199  * Android uses this format as well.
 200  *
 201  * Note that the notifier provides which bits are changed in the state
 202  * variable with the val parameter (second) to the callback.
 203  */
 204 int extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state)
 205 {
 206         char name_buf[120];
 207         char state_buf[120];
 208         char *prop_buf;
 209         char *envp[3];
 210         int env_offset = 0;
 211         int length;
 212         unsigned long flags;
 213
 214         spin_lock_irqsave(&edev->lock, flags);
 215
 216         if (edev->state != ((edev->state & ~mask) | (state & mask))) {
 217                 u32 old_state = edev->state;
 218
 219                 if (check_mutually_exclusive(edev, (edev->state & ~mask) |
 220                                                    (state & mask))) {
 221                         spin_unlock_irqrestore(&edev->lock, flags);
 222                         return -EPERM;
 223                 }
 224
 225                 edev->state &= ~mask;
 226                 edev->state |= state & mask;
 227
 228                 raw_notifier_call_chain(&edev->nh, old_state, edev);
 229
 230                 /* This could be in interrupt handler */
 231                 prop_buf = (char *)get_zeroed_page(GFP_ATOMIC);
 232                 if (prop_buf) {
 233                         length = name_show(edev->dev, NULL, prop_buf);
 234                         if (length > 0) {
 235                                 if (prop_buf[length - 1] == '\n')
 236                                         prop_buf[length - 1] = 0;
 237                                 snprintf(name_buf, sizeof(name_buf),
 238                                         "NAME=%s", prop_buf);
 239                                 envp[env_offset++] = name_buf;
 240                         }
 241                         length = state_show(edev->dev, NULL, prop_buf);
 242                         if (length > 0) {
 243                                 if (prop_buf[length - 1] == '\n')
 244                                         prop_buf[length - 1] = 0;
 245                                 snprintf(state_buf, sizeof(state_buf),
 246                                         "STATE=%s", prop_buf);
 247                                 envp[env_offset++] = state_buf;
 248                         }
 249                         envp[env_offset] = NULL;
 250                         /* Unlock early before uevent */
 251                         spin_unlock_irqrestore(&edev->lock, flags);
 252
 253                         kobject_uevent_env(&edev->dev->kobj, KOBJ_CHANGE, envp);
 254                         free_page((unsigned long)prop_buf);
 255                 } else {
 256                         /* Unlock early before uevent */
 257                         spin_unlock_irqrestore(&edev->lock, flags);
 258
 259                         dev_err(edev->dev, "out of memory in extcon_set_state\n");
 260                         kobject_uevent(&edev->dev->kobj, KOBJ_CHANGE);
 261                 }
 262         } else {
 263                 /* No changes */
 264                 spin_unlock_irqrestore(&edev->lock, flags);
 265         }
 266
 267         return 0;
 268 }
 269 EXPORT_SYMBOL_GPL(extcon_update_state);
 270
 271 /**
 272  * extcon_set_state() - Set the cable attach states of the extcon device.
 273  * @edev:       the extcon device
 274  * @state:      new cable attach status for @edev
 275  *
 276  * Note that notifier provides which bits are changed in the state
 277  * variable with the val parameter (second) to the callback.
 278  */
 279 int extcon_set_state(struct extcon_dev *edev, u32 state)
 280 {
 281         return extcon_update_state(edev, 0xffffffff, state);
 282 }
 283 EXPORT_SYMBOL_GPL(extcon_set_state);
 284
 285 /**
 286  * extcon_find_cable_index() - Get the cable index based on the cable name.
 287  * @edev:       the extcon device that has the cable.
 288  * @cable_name: cable name to be searched.
 289  *
 290  * Note that accessing a cable state based on cable_index is faster than
 291  * cable_name because using cable_name induces a loop with strncmp().
 292  * Thus, when get/set_cable_state is repeatedly used, using cable_index
 293  * is recommended.
 294  */
 295 int extcon_find_cable_index(struct extcon_dev *edev, const char *cable_name)
 296 {
 297         int i;
 298
 299         if (edev->supported_cable) {
 300                 for (i = 0; edev->supported_cable[i]; i++) {
 301                         if (!strncmp(edev->supported_cable[i],
 302                                 cable_name, CABLE_NAME_MAX))
 303                                 return i;
 304                 }
 305         }
 306
 307         return -EINVAL;
 308 }
 309 EXPORT_SYMBOL_GPL(extcon_find_cable_index);
 310
 311 /**
 312  * extcon_get_cable_state_() - Get the status of a specific cable.
 313  * @edev:       the extcon device that has the cable.
 314  * @index:      cable index that can be retrieved by extcon_find_cable_index().
 315  */
 316 int extcon_get_cable_state_(struct extcon_dev *edev, int index)
 317 {
 318         if (index < 0 || (edev->max_supported && edev->max_supported <= index))
 319                 return -EINVAL;
 320
 321         return !!(edev->state & (1 << index));
 322 }
 323 EXPORT_SYMBOL_GPL(extcon_get_cable_state_);
 324
 325 /**
 326  * extcon_get_cable_state() - Get the status of a specific cable.
 327  * @edev:       the extcon device that has the cable.
 328  * @cable_name: cable name.
 329  *
 330  * Note that this is slower than extcon_get_cable_state_.
 331  */
 332 int extcon_get_cable_state(struct extcon_dev *edev, const char *cable_name)
 333 {
 334         return extcon_get_cable_state_(edev, extcon_find_cable_index
 335                                                 (edev, cable_name));
 336 }
 337 EXPORT_SYMBOL_GPL(extcon_get_cable_state);
 338
 339 /**
 340  * extcon_set_cable_state_() - Set the status of a specific cable.
 341  * @edev:       the extcon device that has the cable.
 342  * @index:      cable index that can be retrieved by extcon_find_cable_index().
 343  * @cable_state:        the new cable status. The default semantics is
 344  *                      true: attached / false: detached.
 345  */
 346 int extcon_set_cable_state_(struct extcon_dev *edev,
 347                         int index, bool cable_state)
 348 {
 349         u32 state;
 350
 351         if (index < 0 || (edev->max_supported && edev->max_supported <= index))
 352                 return -EINVAL;
 353
 354         state = cable_state ? (1 << index) : 0;
 355         return extcon_update_state(edev, 1 << index, state);
 356 }
 357 EXPORT_SYMBOL_GPL(extcon_set_cable_state_);
 358
 359 /**
 360  * extcon_set_cable_state() - Set the status of a specific cable.
 361  * @edev:       the extcon device that has the cable.
 362  * @cable_name: cable name.
 363  * @cable_state:        the new cable status. The default semantics is
 364  *                      true: attached / false: detached.
 365  *
 366  * Note that this is slower than extcon_set_cable_state_.
 367  */
 368 int extcon_set_cable_state(struct extcon_dev *edev,
 369                         const char *cable_name, bool cable_state)
 370 {
 371         return extcon_set_cable_state_(edev, extcon_find_cable_index
 372                                         (edev, cable_name), cable_state);
 373 }
 374 EXPORT_SYMBOL_GPL(extcon_set_cable_state);
 375
 376 /**
 377  * extcon_get_extcon_dev() - Get the extcon device instance from the name
 378  * @extcon_name:        The extcon name provided with extcon_dev_register()
 379  */
 380 struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name)
 381 {
 382         struct extcon_dev *sd;
 383
 384         mutex_lock(&extcon_dev_list_lock);
 385         list_for_each_entry(sd, &extcon_dev_list, entry) {
 386                 if (!strcmp(sd->name, extcon_name))
 387                         goto out;
 388         }
 389         sd = NULL;
 390 out:
 391         mutex_unlock(&extcon_dev_list_lock);
 392         return sd;
 393 }
 394 EXPORT_SYMBOL_GPL(extcon_get_extcon_dev);
 395
 396 static int _call_per_cable(struct notifier_block *nb, unsigned long val,
 397                            void *ptr)
 398 {
 399         struct extcon_specific_cable_nb *obj = container_of(nb,
 400                         struct extcon_specific_cable_nb, internal_nb);
 401         struct extcon_dev *edev = ptr;
 402
 403         if ((val & (1 << obj->cable_index)) !=
 404             (edev->state & (1 << obj->cable_index))) {
 405                 bool cable_state = true;
 406
 407                 obj->previous_value = val;
 408
 409                 if (val & (1 << obj->cable_index))
 410                         cable_state = false;
 411
 412                 return obj->user_nb->notifier_call(obj->user_nb,
 413                                 cable_state, ptr);
 414         }
 415
 416         return NOTIFY_OK;
 417 }
 418
 419 /**
 420  * extcon_register_interest() - Register a notifier for a state change of a
 421  *                            specific cable, not an entier set of cables of a
 422  *                            extcon device.
 423  * @obj:        an empty extcon_specific_cable_nb object to be returned.
 424  * @extcon_name:        the name of extcon device.
 425  *                      if NULL, extcon_register_interest will register
 426  *                      every cable with the target cable_name given.
 427  * @cable_name:         the target cable name.
 428  * @nb:         the notifier block to get notified.
 429  *
 430  * Provide an empty extcon_specific_cable_nb. extcon_register_interest() sets
 431  * the struct for you.
 432  *
 433  * extcon_register_interest is a helper function for those who want to get
 434  * notification for a single specific cable's status change. If a user wants
 435  * to get notification for any changes of all cables of a extcon device,
 436  * he/she should use the general extcon_register_notifier().
 437  *
 438  * Note that the second parameter given to the callback of nb (val) is
 439  * "old_state", not the current state. The current state can be retrieved
 440  * by looking at the third pameter (edev pointer)'s state value.
 441  */
 442 int extcon_register_interest(struct extcon_specific_cable_nb *obj,
 443                              const char *extcon_name, const char *cable_name,
 444                              struct notifier_block *nb)
 445 {
 446         if (!obj || !cable_name || !nb)
 447                 return -EINVAL;
 448
 449         if (extcon_name) {
 450                 obj->edev = extcon_get_extcon_dev(extcon_name);
 451                 if (!obj->edev)
 452                         return -ENODEV;
 453
 454                 obj->cable_index = extcon_find_cable_index(obj->edev,
 455                                                           cable_name);
 456                 if (obj->cable_index < 0)
 457                         return obj->cable_index;
 458
 459                 obj->user_nb = nb;
 460
 461                 obj->internal_nb.notifier_call = _call_per_cable;
 462
 463                 return raw_notifier_chain_register(&obj->edev->nh,
 464                                                   &obj->internal_nb);
 465         } else {
 466                 struct class_dev_iter iter;
 467                 struct extcon_dev *extd;
 468                 struct device *dev;
 469
 470                 if (!extcon_class)
 471                         return -ENODEV;
 472                 class_dev_iter_init(&iter, extcon_class, NULL, NULL);
 473                 while ((dev = class_dev_iter_next(&iter))) {
 474                         extd = (struct extcon_dev *)dev_get_drvdata(dev);
 475
 476                         if (extcon_find_cable_index(extd, cable_name) < 0)
 477                                 continue;
 478
 479                         class_dev_iter_exit(&iter);
 480                         return extcon_register_interest(obj, extd->name,
 481                                                 cable_name, nb);
 482                 }
 483
 484                 return -ENODEV;
 485         }
 486 }
 487 EXPORT_SYMBOL_GPL(extcon_register_interest);
 488
 489 /**
 490  * extcon_unregister_interest() - Unregister the notifier registered by
 491  *                              extcon_register_interest().
 492  * @obj:        the extcon_specific_cable_nb object returned by
 493  *              extcon_register_interest().
 494  */
 495 int extcon_unregister_interest(struct extcon_specific_cable_nb *obj)
 496 {
 497         if (!obj)
 498                 return -EINVAL;
 499
 500         return raw_notifier_chain_unregister(&obj->edev->nh, &obj->internal_nb);
 501 }
 502 EXPORT_SYMBOL_GPL(extcon_unregister_interest);
 503
 504 /**
 505  * extcon_register_notifier() - Register a notifiee to get notified by
 506  *                            any attach status changes from the extcon.
 507  * @edev:       the extcon device.
 508  * @nb:         a notifier block to be registered.
 509  *
 510  * Note that the second parameter given to the callback of nb (val) is
 511  * "old_state", not the current state. The current state can be retrieved
 512  * by looking at the third pameter (edev pointer)'s state value.
 513  */
 514 int extcon_register_notifier(struct extcon_dev *edev,
 515                         struct notifier_block *nb)
 516 {
 517         return raw_notifier_chain_register(&edev->nh, nb);
 518 }
 519 EXPORT_SYMBOL_GPL(extcon_register_notifier);
 520
 521 /**
 522  * extcon_unregister_notifier() - Unregister a notifiee from the extcon device.
 523  * @edev:       the extcon device.
 524  * @nb:         a registered notifier block to be unregistered.
 525  */
 526 int extcon_unregister_notifier(struct extcon_dev *edev,
 527                         struct notifier_block *nb)
 528 {
 529         return raw_notifier_chain_unregister(&edev->nh, nb);
 530 }
 531 EXPORT_SYMBOL_GPL(extcon_unregister_notifier);
 532
 533 static struct attribute *extcon_attrs[] = {
 534         &dev_attr_state.attr,
 535         &dev_attr_name.attr,
 536         NULL,
 537 };
 538 ATTRIBUTE_GROUPS(extcon);
 539
 540 static int create_extcon_class(void)
 541 {
 542         if (!extcon_class) {
 543                 extcon_class = class_create(THIS_MODULE, "extcon");
 544                 if (IS_ERR(extcon_class))
 545                         return PTR_ERR(extcon_class);
 546                 extcon_class->dev_groups = extcon_groups;
 547
 548 #if defined(CONFIG_ANDROID)
 549                 switch_class = class_compat_register("switch");
 550                 if (WARN(!switch_class, "cannot allocate"))
 551                         return -ENOMEM;
 552 #endif /* CONFIG_ANDROID */
 553         }
 554
 555         return 0;
 556 }
 557
 558 static void extcon_dev_release(struct device *dev)
 559 {
 560         kfree(dev);
 561 }
 562
 563 static const char *muex_name = "mutually_exclusive";
 564 static void dummy_sysfs_dev_release(struct device *dev)
 565 {
 566 }
 567
 568 /**
 569  * extcon_dev_register() - Register a new extcon device
 570  * @edev        : the new extcon device (should be allocated before calling)
 571  * @dev         : the parent device for this extcon device.
 572  *
 573  * Among the members of edev struct, please set the "user initializing data"
 574  * in any case and set the "optional callbacks" if required. However, please
 575  * do not set the values of "internal data", which are initialized by
 576  * this function.
 577  */
 578 int extcon_dev_register(struct extcon_dev *edev, struct device *dev)
 579 {
 580         int ret, index = 0;
 581
 582         if (!extcon_class) {
 583                 ret = create_extcon_class();
 584                 if (ret < 0)
 585                         return ret;
 586         }
 587
 588         if (edev->supported_cable) {
 589                 /* Get size of array */
 590                 for (index = 0; edev->supported_cable[index]; index++)
 591                         ;
 592                 edev->max_supported = index;
 593         } else {
 594                 edev->max_supported = 0;
 595         }
 596
 597         if (index > SUPPORTED_CABLE_MAX) {
 598                 dev_err(edev->dev, "extcon: maximum number of supported cables exceeded.\n");
 599                 return -EINVAL;
 600         }
 601
 602         edev->dev = kzalloc(sizeof(struct device), GFP_KERNEL);
 603         if (!edev->dev)
 604                 return -ENOMEM;
 605         edev->dev->parent = dev;
 606         edev->dev->class = extcon_class;
 607         edev->dev->release = extcon_dev_release;
 608
 609         edev->name = edev->name ? edev->name : dev_name(dev);
 610         dev_set_name(edev->dev, "%s", edev->name);
 611
 612         if (edev->max_supported) {
 613                 char buf[10];
 614                 char *str;
 615                 struct extcon_cable *cable;
 616
 617                 edev->cables = kzalloc(sizeof(struct extcon_cable) *
 618                                        edev->max_supported, GFP_KERNEL);
 619                 if (!edev->cables) {
 620                         ret = -ENOMEM;
 621                         goto err_sysfs_alloc;
 622                 }
 623                 for (index = 0; index < edev->max_supported; index++) {
 624                         cable = &edev->cables[index];
 625
 626                         snprintf(buf, 10, "cable.%d", index);
 627                         str = kzalloc(sizeof(char) * (strlen(buf) + 1),
 628                                       GFP_KERNEL);
 629                         if (!str) {
 630                                 for (index--; index >= 0; index--) {
 631                                         cable = &edev->cables[index];
 632                                         kfree(cable->attr_g.name);
 633                                 }
 634                                 ret = -ENOMEM;
 635
 636                                 goto err_alloc_cables;
 637                         }
 638                         strcpy(str, buf);
 639
 640                         cable->edev = edev;
 641                         cable->cable_index = index;
 642                         cable->attrs[0] = &cable->attr_name.attr;
 643                         cable->attrs[1] = &cable->attr_state.attr;
 644                         cable->attrs[2] = NULL;
 645                         cable->attr_g.name = str;
 646                         cable->attr_g.attrs = cable->attrs;
 647
 648                         sysfs_attr_init(&cable->attr_name.attr);
 649                         cable->attr_name.attr.name = "name";
 650                         cable->attr_name.attr.mode = 0444;
 651                         cable->attr_name.show = cable_name_show;
 652
 653                         sysfs_attr_init(&cable->attr_state.attr);
 654                         cable->attr_state.attr.name = "state";
 655                         cable->attr_state.attr.mode = 0444;
 656                         cable->attr_state.show = cable_state_show;
 657                 }
 658         }
 659
 660         if (edev->max_supported && edev->mutually_exclusive) {
 661                 char buf[80];
 662                 char *name;
 663
 664                 /* Count the size of mutually_exclusive array */
 665                 for (index = 0; edev->mutually_exclusive[index]; index++)
 666                         ;
 667
 668                 edev->attrs_muex = kzalloc(sizeof(struct attribute *) *
 669                                            (index + 1), GFP_KERNEL);
 670                 if (!edev->attrs_muex) {
 671                         ret = -ENOMEM;
 672                         goto err_muex;
 673                 }
 674
 675                 edev->d_attrs_muex = kzalloc(sizeof(struct device_attribute) *
 676                                              index, GFP_KERNEL);
 677                 if (!edev->d_attrs_muex) {
 678                         ret = -ENOMEM;
 679                         kfree(edev->attrs_muex);
 680                         goto err_muex;
 681                 }
 682
 683                 for (index = 0; edev->mutually_exclusive[index]; index++) {
 684                         sprintf(buf, "0x%x", edev->mutually_exclusive[index]);
 685                         name = kzalloc(sizeof(char) * (strlen(buf) + 1),
 686                                        GFP_KERNEL);
 687                         if (!name) {
 688                                 for (index--; index >= 0; index--) {
 689                                         kfree(edev->d_attrs_muex[index].attr.
 690                                               name);
 691                                 }
 692                                 kfree(edev->d_attrs_muex);
 693                                 kfree(edev->attrs_muex);
 694                                 ret = -ENOMEM;
 695                                 goto err_muex;
 696                         }
 697                         strcpy(name, buf);
 698                         sysfs_attr_init(&edev->d_attrs_muex[index].attr);
 699                         edev->d_attrs_muex[index].attr.name = name;
 700                         edev->d_attrs_muex[index].attr.mode = 0000;
 701                         edev->attrs_muex[index] = &edev->d_attrs_muex[index]
 702                                                         .attr;
 703                 }
 704                 edev->attr_g_muex.name = muex_name;
 705                 edev->attr_g_muex.attrs = edev->attrs_muex;
 706
 707         }
 708
 709         if (edev->max_supported) {
 710                 edev->extcon_dev_type.groups =
 711                         kzalloc(sizeof(struct attribute_group *) *
 712                                 (edev->max_supported + 2), GFP_KERNEL);
 713                 if (!edev->extcon_dev_type.groups) {
 714                         ret = -ENOMEM;
 715                         goto err_alloc_groups;
 716                 }
 717
 718                 edev->extcon_dev_type.name = dev_name(edev->dev);
 719                 edev->extcon_dev_type.release = dummy_sysfs_dev_release;
 720
 721                 for (index = 0; index < edev->max_supported; index++)
 722                         edev->extcon_dev_type.groups[index] =
 723                                 &edev->cables[index].attr_g;
 724                 if (edev->mutually_exclusive)
 725                         edev->extcon_dev_type.groups[index] =
 726                                 &edev->attr_g_muex;
 727
 728                 edev->dev->type = &edev->extcon_dev_type;
 729         }
 730
 731         ret = device_register(edev->dev);
 732         if (ret) {
 733                 put_device(edev->dev);
 734                 goto err_dev;
 735         }
 736 #if defined(CONFIG_ANDROID)
 737         if (switch_class)
 738                 ret = class_compat_create_link(switch_class, edev->dev,
 739                                                NULL);
 740 #endif /* CONFIG_ANDROID */
 741
 742         spin_lock_init(&edev->lock);
 743
 744         RAW_INIT_NOTIFIER_HEAD(&edev->nh);
 745
 746         dev_set_drvdata(edev->dev, edev);
 747         edev->state = 0;
 748
 749         mutex_lock(&extcon_dev_list_lock);
 750         list_add(&edev->entry, &extcon_dev_list);
 751         mutex_unlock(&extcon_dev_list_lock);
 752
 753         return 0;
 754
 755 err_dev:
 756         if (edev->max_supported)
 757                 kfree(edev->extcon_dev_type.groups);
 758 err_alloc_groups:
 759         if (edev->max_supported && edev->mutually_exclusive) {
 760                 for (index = 0; edev->mutually_exclusive[index]; index++)
 761                         kfree(edev->d_attrs_muex[index].attr.name);
 762                 kfree(edev->d_attrs_muex);
 763                 kfree(edev->attrs_muex);
 764         }
 765 err_muex:
 766         for (index = 0; index < edev->max_supported; index++)
 767                 kfree(edev->cables[index].attr_g.name);
 768 err_alloc_cables:
 769         if (edev->max_supported)
 770                 kfree(edev->cables);
 771 err_sysfs_alloc:
 772         kfree(edev->dev);
 773         return ret;
 774 }
 775 EXPORT_SYMBOL_GPL(extcon_dev_register);
 776
 777 /**
 778  * extcon_dev_unregister() - Unregister the extcon device.
 779  * @edev:       the extcon device instance to be unregistered.
 780  *
 781  * Note that this does not call kfree(edev) because edev was not allocated
 782  * by this class.
 783  */
 784 void extcon_dev_unregister(struct extcon_dev *edev)
 785 {
 786         int index;
 787
 788         mutex_lock(&extcon_dev_list_lock);
 789         list_del(&edev->entry);
 790         mutex_unlock(&extcon_dev_list_lock);
 791
 792         if (IS_ERR_OR_NULL(get_device(edev->dev))) {
 793                 dev_err(edev->dev, "Failed to unregister extcon_dev (%s)\n",
 794                                 dev_name(edev->dev));
 795                 return;
 796         }
 797
 798         if (edev->mutually_exclusive && edev->max_supported) {
 799                 for (index = 0; edev->mutually_exclusive[index];
 800                                 index++)
 801                         kfree(edev->d_attrs_muex[index].attr.name);
 802                 kfree(edev->d_attrs_muex);
 803                 kfree(edev->attrs_muex);
 804         }
 805
 806         for (index = 0; index < edev->max_supported; index++)
 807                 kfree(edev->cables[index].attr_g.name);
 808
 809         if (edev->max_supported) {
 810                 kfree(edev->extcon_dev_type.groups);
 811                 kfree(edev->cables);
 812         }
 813
 814 #if defined(CONFIG_ANDROID)
 815         if (switch_class)
 816                 class_compat_remove_link(switch_class, edev->dev, NULL);
 817 #endif
 818         device_unregister(edev->dev);
 819         put_device(edev->dev);
 820 }
 821 EXPORT_SYMBOL_GPL(extcon_dev_unregister);
 822
 823 static int __init extcon_class_init(void)
 824 {
 825         return create_extcon_class();
 826 }
 827 module_init(extcon_class_init);
 828
 829 static void __exit extcon_class_exit(void)
 830 {
 831 #if defined(CONFIG_ANDROID)
 832         class_compat_unregister(switch_class);
 833 #endif
 834         class_destroy(extcon_class);
 835 }
 836 module_exit(extcon_class_exit);
 837
 838 MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
 839 MODULE_AUTHOR("Donggeun Kim <dg77.kim@samsung.com>");
 840 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
 841 MODULE_DESCRIPTION("External connector (extcon) class driver");
 842 MODULE_LICENSE("GPL");