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 int extcon_set_state(struct extcon_dev *edev, u32 state);
 133 static ssize_t state_store(struct device *dev, struct device_attribute *attr,
 134                            const char *buf, size_t count)
 135 {
 136         u32 state;
 137         ssize_t ret = 0;
 138         struct extcon_dev *edev = (struct extcon_dev *) dev_get_drvdata(dev);
 139
 140         ret = sscanf(buf, "0x%x", &state);
 141         if (ret == 0)
 142                 ret = -EINVAL;
 143         else
 144                 ret = extcon_set_state(edev, state);
 145
 146         if (ret < 0)
 147                 return ret;
 148
 149         return count;
 150 }
 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
 167 static ssize_t cable_name_show(struct device *dev,
 168                                struct device_attribute *attr, char *buf)
 169 {
 170         struct extcon_cable *cable = container_of(attr, struct extcon_cable,
 171                                                   attr_name);
 172
 173         return sprintf(buf, "%s\n",
 174                        cable->edev->supported_cable[cable->cable_index]);
 175 }
 176
 177 static ssize_t cable_state_show(struct device *dev,
 178                                 struct device_attribute *attr, char *buf)
 179 {
 180         struct extcon_cable *cable = container_of(attr, struct extcon_cable,
 181                                                   attr_state);
 182
 183         return sprintf(buf, "%d\n",
 184                        extcon_get_cable_state_(cable->edev,
 185                                                cable->cable_index));
 186 }
 187
 188 /**
 189  * extcon_update_state() - Update the cable attach states of the extcon device
 190  *                      only for the masked bits.
 191  * @edev:       the extcon device
 192  * @mask:       the bit mask to designate updated bits.
 193  * @state:      new cable attach status for @edev
 194  *
 195  * Changing the state sends uevent with environment variable containing
 196  * the name of extcon device (envp[0]) and the state output (envp[1]).
 197  * Tizen uses this format for extcon device to get events from ports.
 198  * Android uses this format as well.
 199  *
 200  * Note that the notifier provides which bits are changed in the state
 201  * variable with the val parameter (second) to the callback.
 202  */
 203 int extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state)
 204 {
 205         char name_buf[120];
 206         char state_buf[120];
 207         char *prop_buf;
 208         char *envp[3];
 209         int env_offset = 0;
 210         int length;
 211         unsigned long flags;
 212
 213         spin_lock_irqsave(&edev->lock, flags);
 214
 215         if (edev->state != ((edev->state & ~mask) | (state & mask))) {
 216                 u32 old_state = edev->state;
 217
 218                 if (check_mutually_exclusive(edev, (edev->state & ~mask) |
 219                                                    (state & mask))) {
 220                         spin_unlock_irqrestore(&edev->lock, flags);
 221                         return -EPERM;
 222                 }
 223
 224                 edev->state &= ~mask;
 225                 edev->state |= state & mask;
 226
 227                 raw_notifier_call_chain(&edev->nh, old_state, edev);
 228
 229                 /* This could be in interrupt handler */
 230                 prop_buf = (char *)get_zeroed_page(GFP_ATOMIC);
 231                 if (prop_buf) {
 232                         length = name_show(edev->dev, NULL, prop_buf);
 233                         if (length > 0) {
 234                                 if (prop_buf[length - 1] == '\n')
 235                                         prop_buf[length - 1] = 0;
 236                                 snprintf(name_buf, sizeof(name_buf),
 237                                         "NAME=%s", prop_buf);
 238                                 envp[env_offset++] = name_buf;
 239                         }
 240                         length = state_show(edev->dev, NULL, prop_buf);
 241                         if (length > 0) {
 242                                 if (prop_buf[length - 1] == '\n')
 243                                         prop_buf[length - 1] = 0;
 244                                 snprintf(state_buf, sizeof(state_buf),
 245                                         "STATE=%s", prop_buf);
 246                                 envp[env_offset++] = state_buf;
 247                         }
 248                         envp[env_offset] = NULL;
 249                         /* Unlock early before uevent */
 250                         spin_unlock_irqrestore(&edev->lock, flags);
 251
 252                         kobject_uevent_env(&edev->dev->kobj, KOBJ_CHANGE, envp);
 253                         free_page((unsigned long)prop_buf);
 254                 } else {
 255                         /* Unlock early before uevent */
 256                         spin_unlock_irqrestore(&edev->lock, flags);
 257
 258                         dev_err(edev->dev, "out of memory in extcon_set_state\n");
 259                         kobject_uevent(&edev->dev->kobj, KOBJ_CHANGE);
 260                 }
 261         } else {
 262                 /* No changes */
 263                 spin_unlock_irqrestore(&edev->lock, flags);
 264         }
 265
 266         return 0;
 267 }
 268 EXPORT_SYMBOL_GPL(extcon_update_state);
 269
 270 /**
 271  * extcon_set_state() - Set the cable attach states of the extcon device.
 272  * @edev:       the extcon device
 273  * @state:      new cable attach status for @edev
 274  *
 275  * Note that notifier provides which bits are changed in the state
 276  * variable with the val parameter (second) to the callback.
 277  */
 278 int extcon_set_state(struct extcon_dev *edev, u32 state)
 279 {
 280         return extcon_update_state(edev, 0xffffffff, state);
 281 }
 282 EXPORT_SYMBOL_GPL(extcon_set_state);
 283
 284 /**
 285  * extcon_find_cable_index() - Get the cable index based on the cable name.
 286  * @edev:       the extcon device that has the cable.
 287  * @cable_name: cable name to be searched.
 288  *
 289  * Note that accessing a cable state based on cable_index is faster than
 290  * cable_name because using cable_name induces a loop with strncmp().
 291  * Thus, when get/set_cable_state is repeatedly used, using cable_index
 292  * is recommended.
 293  */
 294 int extcon_find_cable_index(struct extcon_dev *edev, const char *cable_name)
 295 {
 296         int i;
 297
 298         if (edev->supported_cable) {
 299                 for (i = 0; edev->supported_cable[i]; i++) {
 300                         if (!strncmp(edev->supported_cable[i],
 301                                 cable_name, CABLE_NAME_MAX))
 302                                 return i;
 303                 }
 304         }
 305
 306         return -EINVAL;
 307 }
 308 EXPORT_SYMBOL_GPL(extcon_find_cable_index);
 309
 310 /**
 311  * extcon_get_cable_state_() - Get the status of a specific cable.
 312  * @edev:       the extcon device that has the cable.
 313  * @index:      cable index that can be retrieved by extcon_find_cable_index().
 314  */
 315 int extcon_get_cable_state_(struct extcon_dev *edev, int index)
 316 {
 317         if (index < 0 || (edev->max_supported && edev->max_supported <= index))
 318                 return -EINVAL;
 319
 320         return !!(edev->state & (1 << index));
 321 }
 322 EXPORT_SYMBOL_GPL(extcon_get_cable_state_);
 323
 324 /**
 325  * extcon_get_cable_state() - Get the status of a specific cable.
 326  * @edev:       the extcon device that has the cable.
 327  * @cable_name: cable name.
 328  *
 329  * Note that this is slower than extcon_get_cable_state_.
 330  */
 331 int extcon_get_cable_state(struct extcon_dev *edev, const char *cable_name)
 332 {
 333         return extcon_get_cable_state_(edev, extcon_find_cable_index
 334                                                 (edev, cable_name));
 335 }
 336 EXPORT_SYMBOL_GPL(extcon_get_cable_state);
 337
 338 /**
 339  * extcon_set_cable_state_() - Set the status of a specific cable.
 340  * @edev:       the extcon device that has the cable.
 341  * @index:      cable index that can be retrieved by extcon_find_cable_index().
 342  * @cable_state:        the new cable status. The default semantics is
 343  *                      true: attached / false: detached.
 344  */
 345 int extcon_set_cable_state_(struct extcon_dev *edev,
 346                         int index, bool cable_state)
 347 {
 348         u32 state;
 349
 350         if (index < 0 || (edev->max_supported && edev->max_supported <= index))
 351                 return -EINVAL;
 352
 353         state = cable_state ? (1 << index) : 0;
 354         return extcon_update_state(edev, 1 << index, state);
 355 }
 356 EXPORT_SYMBOL_GPL(extcon_set_cable_state_);
 357
 358 /**
 359  * extcon_set_cable_state() - Set the status of a specific cable.
 360  * @edev:       the extcon device that has the cable.
 361  * @cable_name: cable name.
 362  * @cable_state:        the new cable status. The default semantics is
 363  *                      true: attached / false: detached.
 364  *
 365  * Note that this is slower than extcon_set_cable_state_.
 366  */
 367 int extcon_set_cable_state(struct extcon_dev *edev,
 368                         const char *cable_name, bool cable_state)
 369 {
 370         return extcon_set_cable_state_(edev, extcon_find_cable_index
 371                                         (edev, cable_name), cable_state);
 372 }
 373 EXPORT_SYMBOL_GPL(extcon_set_cable_state);
 374
 375 /**
 376  * extcon_get_extcon_dev() - Get the extcon device instance from the name
 377  * @extcon_name:        The extcon name provided with extcon_dev_register()
 378  */
 379 struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name)
 380 {
 381         struct extcon_dev *sd;
 382
 383         mutex_lock(&extcon_dev_list_lock);
 384         list_for_each_entry(sd, &extcon_dev_list, entry) {
 385                 if (!strcmp(sd->name, extcon_name))
 386                         goto out;
 387         }
 388         sd = NULL;
 389 out:
 390         mutex_unlock(&extcon_dev_list_lock);
 391         return sd;
 392 }
 393 EXPORT_SYMBOL_GPL(extcon_get_extcon_dev);
 394
 395 static int _call_per_cable(struct notifier_block *nb, unsigned long val,
 396                            void *ptr)
 397 {
 398         struct extcon_specific_cable_nb *obj = container_of(nb,
 399                         struct extcon_specific_cable_nb, internal_nb);
 400         struct extcon_dev *edev = ptr;
 401
 402         if ((val & (1 << obj->cable_index)) !=
 403             (edev->state & (1 << obj->cable_index))) {
 404                 bool cable_state = true;
 405
 406                 obj->previous_value = val;
 407
 408                 if (val & (1 << obj->cable_index))
 409                         cable_state = false;
 410
 411                 return obj->user_nb->notifier_call(obj->user_nb,
 412                                 cable_state, ptr);
 413         }
 414
 415         return NOTIFY_OK;
 416 }
 417
 418 /**
 419  * extcon_register_interest() - Register a notifier for a state change of a
 420  *                            specific cable, not an entier set of cables of a
 421  *                            extcon device.
 422  * @obj:        an empty extcon_specific_cable_nb object to be returned.
 423  * @extcon_name:        the name of extcon device.
 424  *                      if NULL, extcon_register_interest will register
 425  *                      every cable with the target cable_name given.
 426  * @cable_name:         the target cable name.
 427  * @nb:         the notifier block to get notified.
 428  *
 429  * Provide an empty extcon_specific_cable_nb. extcon_register_interest() sets
 430  * the struct for you.
 431  *
 432  * extcon_register_interest is a helper function for those who want to get
 433  * notification for a single specific cable's status change. If a user wants
 434  * to get notification for any changes of all cables of a extcon device,
 435  * he/she should use the general extcon_register_notifier().
 436  *
 437  * Note that the second parameter given to the callback of nb (val) is
 438  * "old_state", not the current state. The current state can be retrieved
 439  * by looking at the third pameter (edev pointer)'s state value.
 440  */
 441 int extcon_register_interest(struct extcon_specific_cable_nb *obj,
 442                              const char *extcon_name, const char *cable_name,
 443                              struct notifier_block *nb)
 444 {
 445         if (!obj || !cable_name || !nb)
 446                 return -EINVAL;
 447
 448         if (extcon_name) {
 449                 obj->edev = extcon_get_extcon_dev(extcon_name);
 450                 if (!obj->edev)
 451                         return -ENODEV;
 452
 453                 obj->cable_index = extcon_find_cable_index(obj->edev, cable_name);
 454                 if (obj->cable_index < 0)
 455                         return obj->cable_index;
 456
 457                 obj->user_nb = nb;
 458
 459                 obj->internal_nb.notifier_call = _call_per_cable;
 460
 461                 return raw_notifier_chain_register(&obj->edev->nh, &obj->internal_nb);
 462         } else {
 463                 struct class_dev_iter iter;
 464                 struct extcon_dev *extd;
 465                 struct device *dev;
 466
 467                 if (!extcon_class)
 468                         return -ENODEV;
 469                 class_dev_iter_init(&iter, extcon_class, NULL, NULL);
 470                 while ((dev = class_dev_iter_next(&iter))) {
 471                         extd = (struct extcon_dev *)dev_get_drvdata(dev);
 472
 473                         if (extcon_find_cable_index(extd, cable_name) < 0)
 474                                 continue;
 475
 476                         class_dev_iter_exit(&iter);
 477                         return extcon_register_interest(obj, extd->name,
 478                                                 cable_name, nb);
 479                 }
 480
 481                 return -ENODEV;
 482         }
 483 }
 484 EXPORT_SYMBOL_GPL(extcon_register_interest);
 485
 486 /**
 487  * extcon_unregister_interest() - Unregister the notifier registered by
 488  *                              extcon_register_interest().
 489  * @obj:        the extcon_specific_cable_nb object returned by
 490  *              extcon_register_interest().
 491  */
 492 int extcon_unregister_interest(struct extcon_specific_cable_nb *obj)
 493 {
 494         if (!obj)
 495                 return -EINVAL;
 496
 497         return raw_notifier_chain_unregister(&obj->edev->nh, &obj->internal_nb);
 498 }
 499 EXPORT_SYMBOL_GPL(extcon_unregister_interest);
 500
 501 /**
 502  * extcon_register_notifier() - Register a notifiee to get notified by
 503  *                            any attach status changes from the extcon.
 504  * @edev:       the extcon device.
 505  * @nb:         a notifier block to be registered.
 506  *
 507  * Note that the second parameter given to the callback of nb (val) is
 508  * "old_state", not the current state. The current state can be retrieved
 509  * by looking at the third pameter (edev pointer)'s state value.
 510  */
 511 int extcon_register_notifier(struct extcon_dev *edev,
 512                         struct notifier_block *nb)
 513 {
 514         return raw_notifier_chain_register(&edev->nh, nb);
 515 }
 516 EXPORT_SYMBOL_GPL(extcon_register_notifier);
 517
 518 /**
 519  * extcon_unregister_notifier() - Unregister a notifiee from the extcon device.
 520  * @edev:       the extcon device.
 521  * @nb:         a registered notifier block to be unregistered.
 522  */
 523 int extcon_unregister_notifier(struct extcon_dev *edev,
 524                         struct notifier_block *nb)
 525 {
 526         return raw_notifier_chain_unregister(&edev->nh, nb);
 527 }
 528 EXPORT_SYMBOL_GPL(extcon_unregister_notifier);
 529
 530 static struct device_attribute extcon_attrs[] = {
 531         __ATTR(state, S_IRUGO | S_IWUSR, state_show, state_store),
 532         __ATTR_RO(name),
 533         __ATTR_NULL,
 534 };
 535
 536 static int create_extcon_class(void)
 537 {
 538         if (!extcon_class) {
 539                 extcon_class = class_create(THIS_MODULE, "extcon");
 540                 if (IS_ERR(extcon_class))
 541                         return PTR_ERR(extcon_class);
 542                 extcon_class->dev_attrs = extcon_attrs;
 543
 544 #if defined(CONFIG_ANDROID)
 545                 switch_class = class_compat_register("switch");
 546                 if (WARN(!switch_class, "cannot allocate"))
 547                         return -ENOMEM;
 548 #endif /* CONFIG_ANDROID */
 549         }
 550
 551         return 0;
 552 }
 553
 554 static void extcon_dev_release(struct device *dev)
 555 {
 556         kfree(dev);
 557 }
 558
 559 static const char *muex_name = "mutually_exclusive";
 560 static void dummy_sysfs_dev_release(struct device *dev)
 561 {
 562 }
 563
 564 /**
 565  * extcon_dev_register() - Register a new extcon device
 566  * @edev        : the new extcon device (should be allocated before calling)
 567  * @dev         : the parent device for this extcon device.
 568  *
 569  * Among the members of edev struct, please set the "user initializing data"
 570  * in any case and set the "optional callbacks" if required. However, please
 571  * do not set the values of "internal data", which are initialized by
 572  * this function.
 573  */
 574 int extcon_dev_register(struct extcon_dev *edev, struct device *dev)
 575 {
 576         int ret, index = 0;
 577
 578         if (!extcon_class) {
 579                 ret = create_extcon_class();
 580                 if (ret < 0)
 581                         return ret;
 582         }
 583
 584         if (edev->supported_cable) {
 585                 /* Get size of array */
 586                 for (index = 0; edev->supported_cable[index]; index++)
 587                         ;
 588                 edev->max_supported = index;
 589         } else {
 590                 edev->max_supported = 0;
 591         }
 592
 593         if (index > SUPPORTED_CABLE_MAX) {
 594                 dev_err(edev->dev, "extcon: maximum number of supported cables exceeded.\n");
 595                 return -EINVAL;
 596         }
 597
 598         edev->dev = kzalloc(sizeof(struct device), GFP_KERNEL);
 599         if (!edev->dev)
 600                 return -ENOMEM;
 601         edev->dev->parent = dev;
 602         edev->dev->class = extcon_class;
 603         edev->dev->release = extcon_dev_release;
 604
 605         dev_set_name(edev->dev, "%s", edev->name ? edev->name : dev_name(dev));
 606
 607         if (edev->max_supported) {
 608                 char buf[10];
 609                 char *str;
 610                 struct extcon_cable *cable;
 611
 612                 edev->cables = kzalloc(sizeof(struct extcon_cable) *
 613                                        edev->max_supported, GFP_KERNEL);
 614                 if (!edev->cables) {
 615                         ret = -ENOMEM;
 616                         goto err_sysfs_alloc;
 617                 }
 618                 for (index = 0; index < edev->max_supported; index++) {
 619                         cable = &edev->cables[index];
 620
 621                         snprintf(buf, 10, "cable.%d", index);
 622                         str = kzalloc(sizeof(char) * (strlen(buf) + 1),
 623                                       GFP_KERNEL);
 624                         if (!str) {
 625                                 for (index--; index >= 0; index--) {
 626                                         cable = &edev->cables[index];
 627                                         kfree(cable->attr_g.name);
 628                                 }
 629                                 ret = -ENOMEM;
 630
 631                                 goto err_alloc_cables;
 632                         }
 633                         strcpy(str, buf);
 634
 635                         cable->edev = edev;
 636                         cable->cable_index = index;
 637                         cable->attrs[0] = &cable->attr_name.attr;
 638                         cable->attrs[1] = &cable->attr_state.attr;
 639                         cable->attrs[2] = NULL;
 640                         cable->attr_g.name = str;
 641                         cable->attr_g.attrs = cable->attrs;
 642
 643                         sysfs_attr_init(&cable->attr_name.attr);
 644                         cable->attr_name.attr.name = "name";
 645                         cable->attr_name.attr.mode = 0444;
 646                         cable->attr_name.show = cable_name_show;
 647
 648                         sysfs_attr_init(&cable->attr_state.attr);
 649                         cable->attr_state.attr.name = "state";
 650                         cable->attr_state.attr.mode = 0444;
 651                         cable->attr_state.show = cable_state_show;
 652                 }
 653         }
 654
 655         if (edev->max_supported && edev->mutually_exclusive) {
 656                 char buf[80];
 657                 char *name;
 658
 659                 /* Count the size of mutually_exclusive array */
 660                 for (index = 0; edev->mutually_exclusive[index]; index++)
 661                         ;
 662
 663                 edev->attrs_muex = kzalloc(sizeof(struct attribute *) *
 664                                            (index + 1), GFP_KERNEL);
 665                 if (!edev->attrs_muex) {
 666                         ret = -ENOMEM;
 667                         goto err_muex;
 668                 }
 669
 670                 edev->d_attrs_muex = kzalloc(sizeof(struct device_attribute) *
 671                                              index, GFP_KERNEL);
 672                 if (!edev->d_attrs_muex) {
 673                         ret = -ENOMEM;
 674                         kfree(edev->attrs_muex);
 675                         goto err_muex;
 676                 }
 677
 678                 for (index = 0; edev->mutually_exclusive[index]; index++) {
 679                         sprintf(buf, "0x%x", edev->mutually_exclusive[index]);
 680                         name = kzalloc(sizeof(char) * (strlen(buf) + 1),
 681                                        GFP_KERNEL);
 682                         if (!name) {
 683                                 for (index--; index >= 0; index--) {
 684                                         kfree(edev->d_attrs_muex[index].attr.
 685                                               name);
 686                                 }
 687                                 kfree(edev->d_attrs_muex);
 688                                 kfree(edev->attrs_muex);
 689                                 ret = -ENOMEM;
 690                                 goto err_muex;
 691                         }
 692                         strcpy(name, buf);
 693                         sysfs_attr_init(&edev->d_attrs_muex[index].attr);
 694                         edev->d_attrs_muex[index].attr.name = name;
 695                         edev->d_attrs_muex[index].attr.mode = 0000;
 696                         edev->attrs_muex[index] = &edev->d_attrs_muex[index]
 697                                                         .attr;
 698                 }
 699                 edev->attr_g_muex.name = muex_name;
 700                 edev->attr_g_muex.attrs = edev->attrs_muex;
 701
 702         }
 703
 704         if (edev->max_supported) {
 705                 edev->extcon_dev_type.groups =
 706                         kzalloc(sizeof(struct attribute_group *) *
 707                                 (edev->max_supported + 2), GFP_KERNEL);
 708                 if (!edev->extcon_dev_type.groups) {
 709                         ret = -ENOMEM;
 710                         goto err_alloc_groups;
 711                 }
 712
 713                 edev->extcon_dev_type.name = dev_name(edev->dev);
 714                 edev->extcon_dev_type.release = dummy_sysfs_dev_release;
 715
 716                 for (index = 0; index < edev->max_supported; index++)
 717                         edev->extcon_dev_type.groups[index] =
 718                                 &edev->cables[index].attr_g;
 719                 if (edev->mutually_exclusive)
 720                         edev->extcon_dev_type.groups[index] =
 721                                 &edev->attr_g_muex;
 722
 723                 edev->dev->type = &edev->extcon_dev_type;
 724         }
 725
 726         ret = device_register(edev->dev);
 727         if (ret) {
 728                 put_device(edev->dev);
 729                 goto err_dev;
 730         }
 731 #if defined(CONFIG_ANDROID)
 732         if (switch_class)
 733                 ret = class_compat_create_link(switch_class, edev->dev,
 734                                                NULL);
 735 #endif /* CONFIG_ANDROID */
 736
 737         spin_lock_init(&edev->lock);
 738
 739         RAW_INIT_NOTIFIER_HEAD(&edev->nh);
 740
 741         dev_set_drvdata(edev->dev, edev);
 742         edev->state = 0;
 743
 744         mutex_lock(&extcon_dev_list_lock);
 745         list_add(&edev->entry, &extcon_dev_list);
 746         mutex_unlock(&extcon_dev_list_lock);
 747
 748         return 0;
 749
 750 err_dev:
 751         if (edev->max_supported)
 752                 kfree(edev->extcon_dev_type.groups);
 753 err_alloc_groups:
 754         if (edev->max_supported && edev->mutually_exclusive) {
 755                 for (index = 0; edev->mutually_exclusive[index]; index++)
 756                         kfree(edev->d_attrs_muex[index].attr.name);
 757                 kfree(edev->d_attrs_muex);
 758                 kfree(edev->attrs_muex);
 759         }
 760 err_muex:
 761         for (index = 0; index < edev->max_supported; index++)
 762                 kfree(edev->cables[index].attr_g.name);
 763 err_alloc_cables:
 764         if (edev->max_supported)
 765                 kfree(edev->cables);
 766 err_sysfs_alloc:
 767         kfree(edev->dev);
 768         return ret;
 769 }
 770 EXPORT_SYMBOL_GPL(extcon_dev_register);
 771
 772 /**
 773  * extcon_dev_unregister() - Unregister the extcon device.
 774  * @edev:       the extcon device instance to be unregistered.
 775  *
 776  * Note that this does not call kfree(edev) because edev was not allocated
 777  * by this class.
 778  */
 779 void extcon_dev_unregister(struct extcon_dev *edev)
 780 {
 781         int index;
 782
 783         mutex_lock(&extcon_dev_list_lock);
 784         list_del(&edev->entry);
 785         mutex_unlock(&extcon_dev_list_lock);
 786
 787         if (IS_ERR_OR_NULL(get_device(edev->dev))) {
 788                 dev_err(edev->dev, "Failed to unregister extcon_dev (%s)\n",
 789                                 dev_name(edev->dev));
 790                 return;
 791         }
 792
 793         if (edev->mutually_exclusive && edev->max_supported) {
 794                 for (index = 0; edev->mutually_exclusive[index];
 795                                 index++)
 796                         kfree(edev->d_attrs_muex[index].attr.name);
 797                 kfree(edev->d_attrs_muex);
 798                 kfree(edev->attrs_muex);
 799         }
 800
 801         for (index = 0; index < edev->max_supported; index++)
 802                 kfree(edev->cables[index].attr_g.name);
 803
 804         if (edev->max_supported) {
 805                 kfree(edev->extcon_dev_type.groups);
 806                 kfree(edev->cables);
 807         }
 808
 809 #if defined(CONFIG_ANDROID)
 810         if (switch_class)
 811                 class_compat_remove_link(switch_class, edev->dev, NULL);
 812 #endif
 813         device_unregister(edev->dev);
 814         put_device(edev->dev);
 815 }
 816 EXPORT_SYMBOL_GPL(extcon_dev_unregister);
 817
 818 static int __init extcon_class_init(void)
 819 {
 820         return create_extcon_class();
 821 }
 822 module_init(extcon_class_init);
 823
 824 static void __exit extcon_class_exit(void)
 825 {
 826 #if defined(CONFIG_ANDROID)
 827         class_compat_unregister(switch_class);
 828 #endif
 829         class_destroy(extcon_class);
 830 }
 831 module_exit(extcon_class_exit);
 832
 833 MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
 834 MODULE_AUTHOR("Donggeun Kim <dg77.kim@samsung.com>");
 835 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
 836 MODULE_DESCRIPTION("External connector (extcon) class driver");
 837 MODULE_LICENSE("GPL");